Siam Physics Congress 2015

May 20, 2015, 8:00 AM → May 22, 2015, 8:15 PM Asia/Bangkok

+ 1st Announcement 1st_announcement_english_final.pdf

+ How to register How to register to the SPC2015

หนังสือขออนุมัติจัดประชุมและไม่ถือเป็นวันลา SPC2015-CU.pdf

Wed, May 20

8:00 AM → 9:00 AM Registration

9:00 AM → 9:15 AM Opening Ceremony

9:00 AM Greeting

Speakers: Prof. Sukit Limpijumnong (Thai Physics Society), Prof. Supot Hannongbua (Faculty of Science, Chulalongkorn University)

9:10 AM Opening ceremony

Speaker: Dr Weerapong Paesuwan (Ministry of Science and Technology)

9:15 AM → 10:00 AM Plenary: HRH Princess Maha Chakri Sirindhorn’s Initiatives in S&T for the well-being and benefit of Thai citizens

9:15 AM HRH Princess Maha Chakri Sirindhorn’s Initiatives in S&T for the well-being and benefit of Thai citizens

Her Royal Highness Princess Maha Chakri Sirindhorn was born in Bangkok on the second of April, 1955 as a daughter of Their Majesties King Bhumibol Adulyadej and Queen Sirikit of Thailand. Apart from her excellent background education in history, language and education development, HRH has been interested in science and technology subjects, particularly for the well being and benefit of Thai citizens. Through the IT Project Under HRH Princess Maha Chakri Sirindhorn’s Initiatives, HRH has used information technology to alleviate the underprivileged such as school students in remote areas, people with disability, chronic young patients in hospitals, and inmates. HRH has also keen interest in promoting young Thai scientists and researchers to participate internationally in the advancement of science and technology. Examples in independent living of people with disability, solar energy for schools in mountainous areas to receive distance learning via satellite, Thai scientist participation in arctic research, and CERN high energy physics will be presented.

Speaker: Prof. Pairash THAJCHAYAPONG (National Science and Technology Development Agency, Thailand)

10:00 AM → 10:30 AM Photo session & Coffee break

10:30 AM → 11:30 AM Plenary: Celebrating Hundred Years of General Relativity

10:30 AM Celebrating Hundred Years of General Relativity

This talk first discusses the history surrounding the discovery of General Relativity by Einstein in 1915. It next discusses the present status of the theory and some of its shortcomings. Finally, a view on the future of General Relativity will be presented.

Speaker: Prof. Eric BERGSHOEFF (University of Groningen, The Netherlands)

11:30 AM → 1:00 PM Lunch

1:00 PM → 2:00 PM Plenary: The string theory – condensed matter flirtation: an eyewitness account

1:00 PM The string theory – condensed matter flirtation: an eyewitness account

A quake is rumbling through the core of physics: the empiricisms of condensed matter physics and the mathematics of string theory appear to have some deep relations. For the initiated this has an unusually strong allure, but since this cocktail involves some of the most impenetrable areas of physics it is not easy to communicate the excitement to the community at large. I will attempt to get some of it across by telling the story from the perspective of a condensed matter theorist who learned string theory only quite recently. How string theory evolved from a reductionist’s enterprise into some modern incarnation of statistical physics, equipped with general relativity turbo’s and quantum information boosters in the form of the “AdS/CFT” holographic duality. How the universality of general relativity turned into a classification method for phases of matter, including new forms of “quantum” matter characterised by dense quantum entanglements on the macroscopic scale. How the latter reveal highly unusual traits having eerie resemblances with the mysterious experimental observations, with as highlight the famous linear resistivity measured in the strange metal phase of the high Tc superconductors.

Speaker: Prof. Jan ZAANEN (Instituut-Lorentz for Theoretical Physics, Leiden University, The Netherlands)

2:00 PM → 5:30 PM Poster-1

2:00 PM A gridded planar probe as a plasma diagnostic tool in a dc magnetron sputtering

A gridded planar probe has been developed to measure plasma parameters in a dc magnetron sputtering discharge. The gridded probe essentially consists of an outer grid in conjunction with the inner collector forming a stacked electrode configuration. The grid space needs to be less than the Debye length in order to assume the planar plasma-sheath structure. In addition, the grid-to-collector distance should be shorter than the mean free path of electron ionization collisions to prevent undesirable plasma generated inside the probe. The I-V characteristic of the probe is obtained by applying bias voltages to both electrodes but only measuring the current from the collector. Consequently, plasma parameters including ion flux, electron temperature, and ion and electron densities can be calculated from the probe characteristic based on the collisionless planar sheath model. It is found in the ion saturation region that the probe current is almost independent of the bias voltage due to a well-defined planar sheath structure adjacent to the grid. As a result, the ion flux can be obtained to a fair degree of certainty. For the discharge conditions achieved in this study, electron density and temperature are found in the range of ~10$^{15}$ m$^{-3}$ and 2-6 eV, respectively, which agree well with those obtained using a cylindrical Langmuir probe and a flat probe with a guard ring.

Speaker: Mr Peerawat Laohana (Department of Physics, Faculty of Science, Mahasarakham University, Mahasarakham 44150, Thailand)

2:00 PM A small vertical axis wind turbine

The main objectives of this project were to design and construct the compact Savonius vertical axis wind turbine having cut-in speed of 3 m/s. This Savonius wind turbine was made of 4 S-shaped blades steel coating with Zinc with diameter of 1 m. Power of wind was transferred to generator by using O-ring at pulley ratio of 1:25 The results showed that at wind speed of 3.0 m/s the power efficiency of wind turbine was about of 55.95% whilst the efficiency of wind turbine was related to wind speed.

Speaker: Mr Singkarn Chanprateep (Department of Physics, Faculty of Science, Prince of Songkla University, Songkhla, THAILAND 90110)

2:00 PM A study of $\beta$-Cu(In,Ga)$_3$Se$_5$ effects on Cu(In,Ga)Se$_2$ thin film solar cells

$\rm Cu(In,Ga)_3Se_5$ is known as a $\beta$-phase in the phase diagram of $\rm Cu_2$Se and $\rm (In,Ga)_2Se_3$. The existence of this phase on the surface of $\rm Cu(In,Ga)Se_2$ absorber plays an important role for enhancing the performance of $\rm Cu(In,Ga)Se_2$ solar cells. The energy dispersive x-ray spectroscopy (EDX) is used to investigate and confirm the composition of single $\rm Cu(In,Ga)_3Se_5$ film and in order to obtain the deposition conditions. In this study, the $\beta$-$\rm Cu(In,Ga)_3Se_5$ with various thicknesses were deposited after a completion of the three-stage co-evaporation process of $\rm Cu(In,Ga)Se_2$ films. The solar cells with thinner $\rm Cu(In,Ga)_3Se_5$ showed an increase in open-circuit voltage ($V_o$$_c$). The maximum $V_o$$_c$ of 0.707 V was obtained from $\rm Cu(In,Ga)_3Se_5$ film with 10 nm thick. It is noted here that the conversion efficiencies are slightly lower when compared with the standard three-stage growth solar cells without $\rm Cu(In,Ga)_3Se_5$. It is mainly due to a decrease in a short circuit current ($J_s$$_c$) and a fill factor (FF). Based on previous studies, the higher $V_o$$_c$ was obtained by a larger energy band gap caused by valence band offset at the CdS/CIGS interface.

Speaker: Ms Boonyaluk Namnuan (Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok, THAILAND 10330)

2:00 PM A Study of the Orbital Period of a Binary System V2790 Ori

V2790 Ori is a W Uma Eclipsing Binary with an orbital period of 0.28784200 day. From the previous investigation of its light curve, it was found that this binary system has a continuous orbital period change. In this research, new photometric B V and R light curves have been obtained to compute time of minimum light. Using the previously published time of minima and the value obtained in this research, an O - C curve of V2790 Ori was constructed. It was found that, this curve trends toward a downward parabolic variation. The result reveals that the orbital period of V2790 Ori there was a decrease in the rate $9.81954433 \times 10^{-6}$ seconds per year to $4.263948685 \times 10^{-6}$ seconds per year.

Speaker: Mr Sarawut Choolok (Department of Physics and General Science, Faculty of Science and Technology, Songkhla Rajabhat University, Songkhla 90000, Thailand)

2:00 PM A Study the Star Formation of Galaxies in a Nearby Galaxies Group

This work aims to study evolution of galaxies, located in a dense environment of a compact group, called NGC 4095 group, that has recession velocities 6,000 $<$ $v$ (km s$^{-1}$) $<$ 8,000. Imaging observations for $BVR_{\rm c}$ broad-band, [$S\rm{II}$] and Red-continuum narrow-band were carried out on the 2.4 m Thai National Telescope (TNT) at Doi Inthanon, Chiang Mai, Thailand. Stellar age and metallicity of the galaxies in this group were estimated by using the model of Pietrinferni (2004). This study shows that late type galaxies tend to be bluer than early type galaxies. Most of late type galaxies are ongoing star formation activity, which could be triggered by galaxy-galaxy or tidal interactions and young massive stars in those galaxies caused their colors bluer than early type galaxies.

Speaker: Ms Panomporn Poojon (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand)

Poster Panomporn_POOJON.pdf

2:00 PM An application of Optical Coherence Tomography (OCT) to measure sucrose concentrations

This work focused on applying the optical coherence tomography (OCT) technique to measure concentrations of sucrose, one of the most widely used sugars in food industry, in solutions. Because the indices of refraction varied with the amount of sucrose dissolved in the solutions, OCT could be used to quantify the sucrose concentration by measuring the optical path length changes. In addition, near-infrared (NIR) light used in OCT often offered better penetration depths for samples with color or turbidity, enabling the technique to measure the sucrose concentrations even in colored media. Initially, transparent aqueous solutions with various sucrose concentrations were loaded into a flow cell and the optical path lengths of the cell were measured by OCT to obtain calibration curves. After optimizations, the system performances were tested. Finally the system was used to measure sucrose concentration in both transparent and colored liquid samples.

Speaker: Ms Sirirat Ouiganon (Department of Physics, Faculty of Science, Prince of Songkla University, Hatyai 90112, Thailand)

2:00 PM An Application of Synchrotron-based X-ray Absorption Spectroscopy Study on Advanced Functional Materials

The investigation of the local geometric and electronic structure of probing element in bulk samples is the most extensive field of application in X-ray Absorption Spectroscopy (XAS). XAS consists of two main regions which are X-ray Absorption Near Edge Structure (XANES) and Extended X-ray Absorption Fine Structure (EXAFS). The former region is used to explain the local geometry and oxidation states of selected element in a sample whilst the latter one is used to address the local structure around probing element in samples. In my work, the XAS beamline : SUT-NANOTEC-SLRI XAS beamline (BL 5.2) at the Synchrotron Light Research Institute, THAILAND, and applications of synchrotron-based XAS on advanced functional materials such as carbon-ferrite composite nanofibers and thermoelectric materials will be introduced in order to obtain the accuracy of their locally structural information which cause different properties in these materials.

Speaker: Pinit Kidkhunthod (Synchrotron Light Research Institute (Public Organization), 111 University Avenue, Muang District, Nakhon Ratchasima 30000, Thailand)

2:00 PM Analysis of Color Magnitude Diagram by Aperture Photometry Tool

The variations of stellar brightness in globular clusters are major evidence of their evolutions. In this study, optical images of two globular clusters were taken. First, images of NGC6121 (M4) were taken by Panchromatic Robotic Optical Monitoring and Polarimetry Telescopes 8 (PROMPT 8) at Cerro Tololo national observatory, Chile. Later, images of NGC7078 (M15), were taken by 2.4m Telescope at Thai National Observatory in Thailand. The images were reduced and analyzed by Aperture Photometry Tool to measure the absolute magnitude for each star in the cluster. The calculated magnitudes were used to create plots between color index B-V and the apparent magnitude in filter V. The plot is generally known as Color Magnitude Diagram (CMD), which is a simple form of Hertzsprung - Russell diagram (H-R Diagram). CMD for NGC6121 and NGC7078 were compared to previous studies by Patrick R. Durrell and William E. Harris (1993) and G. Alcaino, W. Liller, and F. Alvarado (1997) respectively. The results from this study show similar evolution trends to previous studies. Upon the analysis of the evolution curves, the positions of the main-sequence turnoff are found to be at $V \sim 16-17$, $(B-V) \sim 0.8-1.0$ for NGC6121 and $V \sim 19-20$, $(B-V) \sim 0.3-0.5$ for NGC7078. Furthermore, the ages of both clusters were calculated based on the magnitudes of stars at the positions of the main-sequence turnoff. We found that their ages are different from the previous studies, although in the same order of Gyr. For further detailed analysis, the effect of extinction due to interstellar medium should be taken into consideration.

Speaker: Kamolporn Haewsantati (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand)

2:00 PM Analytical Black Hole Solution in dRGT Massive Gravity

Massive gravity is a modified gravity in which a mass is given to the spin-2 field. There are various kinds of massive gravity models. One of viable model which is received enormous attention to investigate in cosmology is “dRGT massive gravity”. Since it is a gravity theory, it must reduce to general relativity at Solar system scale. Black hole solution is one of well-known solutions in general relativity at this scale. In this presentation, we try to find an analytical black hole solution in dRGT massive gravity. It is found that the solution can be recover various kind of black hole solutions, for example dS/AdS black hole, black hole with global monopole. We also argue that it is possible to obtain regular black hole from dRGT massive gravity.

Speaker: Dr Pitayuth Wongjun (The Institute for Fundamental Study, Naresuan University, Phitsanulok 65000, Thailand)

2:00 PM Beam loss monitor system at SPS storage ring

Siam Photon Source (SPS) storage ring is an electron source with the electron beam energy of 1.2 GeV. In order to better understand behaviors of the electron beam, 50 beam loss monitors (BLMs) have been installed in the SPS storage ring to monitor the electron beam loss signals. BLMs consist of two pin-diodes which are sensitive to the minimum ionizing particles (MIPs) when the electron hits the vacuum chamber. The electron beam loss signals are counted and recorded every second by NI-PXIe system. These results are useful for studying lifetime and stability of the electron beam stored in the SPS storage ring.

Speaker: Siriwan Krainara (Accelerator Technology Division, Synchrotron Light Research Institute (Public Organization), 111 University Avenue, Muang District, Nakhon Ratchasima 30000, Thailand)

2:00 PM Characterization of Plasma Conditions for Reactive Pulsed DC Magnetron Sputtering System

Reactive pulsed dc magnetron sputtering technique is highly effective in thin film deposition, particularly thin film of dielectric materials. In this work, we design and set up reactive pulsed dc magnetron sputtering system for deposition of Titanium Nitride (TiN) and Titanium Nitride-Hydroxyapatite (TiN-HA). Suitable plasma conditions for deposition are analyzed using the current-voltage characteristic and optical emission spectroscopy. In this experiment, the pulsing parameters (frequency and duty cycle) and glow discharge parameters (voltage and pressure) are varied.

Speaker: Ms Panadda Waruriya (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University,Huay Kaew Road, Muang District, Chiang Mai, Thailand, 50200)

Poster Characterization_of_Plasma_Conditions_for_Reactive_Pulsed_DC_Magnetron_Sputtering_System_(2).pdf

2:00 PM Characterization of the New CCD Camera for Neutron Tomography at the Thai Research Reactor-1/Modification 1

Neutron tomography is a method to investigate a sample via a three dimensional (3D) image produced by neutron absorption. It is widely applied in many fields such as, medical, industrial and archeological. By reconstructing 2D images taken from different angles, the 3D information can be created. In order to obtain a 2D image of which the quality is good enough for neutron tomography with a short period of irradiation, a high efficiency neutron camera is needed. The aim of this research is to characterize the new CCD camera for neutron tomography at the Thai Research Reactor-1/Modification 1 (TRR-1/M1). The neutron camera manufactured by NeutronOptics is composed of three main parts: the Kodak KAI-4022 CCD with 2048×2048 pixel resolution, the Nikkor f/1.2 lens with the focal length of 50 mm and the Lithium Fluorine-Zinc Sulphide (LiF-ZnS) scintillation screen. The experimental investigation was performed at the radiographic position of 100 cm from the neutron beam port of TRR-1/M1. Thermal neutron flux at this position is about 10^6 n.cm-2s-1. At first, the sensitivity indicator (SI) standard sample and the in-house acrylic step wedge were radiographed to evaluate the sensitivity and the resolution of the camera. Then, the exposure time and the distance were varied to determine appropriate exposure conditions. The obtained images from the new CCD camera were analyzed using ImageJ software. Detailed results and discussion of this investigation will be presented in the manuscript.

Speaker: Dr Sarinrat Wonglee (Thailand Institute of Nuclear Technology)

2:00 PM Characterizations of PZT films prepared by sol-gel spin coating method

Lead zirconate titanate (PZT) films have been widely used for micro applications because of their excellent ferroelectric and piezoelectric properties. In this study, surface morphology and electrical properties of lead zirconate titanate films have been investigated. The PZT films have been prepared by a sol-gel method and deposited on silicon wafers by spin coating under different annealing processes. Phase formation behavior of these films was investigated by an X-ray diffraction (XRD). The Atomic Force Microscopy (AFM) explains morphology, such as surface roughness, grain shape and grain size. Dielectric properties were studied using LCR meter measurement and discussed in this paper. PZT films show a perovskite phase at annealing temperature of 650 °C. For the films thickness were in the range of 500 – 900 nm. Average grain size increase with increasing the annealing temperatures. Dielectric constant show the highest value which was found at condition of 650 °C.

Speakers: Ms Kamonpan Pengpat (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai, 50200, Thailand.), Mr Pichitchai Butnoi (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai, 50200, Thailand)

2:00 PM Cold atmospheric pressure plasma diagnostics using an UV-absorption spectroscopy

Cold atmospheric pressure plasma consisting of OH, O, O${}_3$, NO, and NO${}_2$ radicals is currently popular in biomedical applications. This is due to its ability on destroying microbes and stimulating on production of new cells. For such applications, development of techniques to measure density of any radical in the plasma is important. An optical emission spectroscopy (OES) technique, which is used in most laboratories, has a limitation for estimating the radical density on specific area. In this study, we develop a method to use an UV-absorption spectroscopy for measuring the density of the OH, NO, and NO${}_2$ radicals on sample surfaces. Study on effect of the atmospheric jet with various conditions is performed. Principle and procedure of the UV-absorption spectroscopy technique as well as the experimental results will be reported and discussed in this contribution.

Speaker: Mr Yuthana Thana (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand)

Poster YuthanaThanaSPC2015.pdf

2:00 PM Comparison of electrical properties of LaSrCoFe films prepared by suspension and by gel coating method

$\rm La_{0.56}Sr_{0.4}Co_{0.2}Fe_{0.8}O_3$-$\delta$ (LSCF) thin films were fabricated on a yttrium stabilized zirconia (YSZ) pellet from either solutions containing LSCF suspension or LSCF sol gels. The suspensions and gel precursors were applied on the substrate via a conventional spraying and a dip coating, respectively. The LSCF films and the YSZ substrates were co-fired at 1100 $^o$C. From SEM, the gel-derived films showed a densely-packed structure whilst the films prepared from suspended LSCF did not have such characteristics. The electrochemical impedance spectra unambiguously implied the better film-substrate interface for the gel-derived films as their interfacial resistivities were lower than those prepared by the suspension spray routes.

Speaker: Mr Shatchai Promsuy (Department of Physics, Faculty of science, Khon Kaen University, 40002 Khon Kaen, Thailand)

2:00 PM Correlation factors of wire sweep between wire bond and mold to establish process design rule

The effects of wire sweep within the integrated circuit (IC) packaging process were studied in this research. Wire sweep is a major criteria that causes the shortage of wire between adjacent areas such as die and mold compound. It occur from the molding process after the wire bonding process in IC assembly. In experiment, the parameters of wire sweep were varied by wire size from 0.7 to 1.0 mil, wire height were varied from 3.0 to 5.0 mil, and in board bond wire length were varied from 10%, 30%, and 50% respectively. The results revealed that the wire height and the inboard wire length were showed directly proportional to wire sweep. In the opposite way, the wire size was showed inversely proportional to wire sweep. Therefore, these parameters of wire were played the important rule in IC packaging process. It should be selected properly for reducing the lot reject rate.

Speaker: Anocha Sanorit (Department of Industrial Physics and Medical Instrumentation, Faculty of Science, King Mongkut's University of Technology North Bangkok, Bangkok, THAILAND 10800)

Poster Poster_Wire_Sweep_pdf_New.pdf

2:00 PM Decay of Hexaaquo Nickel(I) and Zinc(I) Ions in High Temperature Water

The decay of the monovalent transition metal ions (Ni+(aq) and Zn+(aq)) in pure water have been studied at temperatures up to 300oC using a pulse radiolysis technique with a transient UV-visible detection system. The results indicate that the reactions of the hexaaquo ions with radiolytic oxidizing species are responsible for this phenomenon. The disportionation nature of the ions has been investigated in aqueous methanol. The kinetics model based on water radiolysis has shown that Ni+(aq) ions do not proportionate. Unlike Ni+(aq), Zn+(aq) ions undergo disproportionation generating metallic zinc with a relatively slow rate. The application of Smoluchowski equation has revealed that all of the reactions investigated are not diffusion-controlled, one exception being the reaction of Ni+(aq) with ●OH radicals at room temperature. The reaction activation energies and the high-temperature optical spectra of Ni+(aq) and Zn+(aq) have been reported.

Speaker: Dr Kotchaphan Kanjana (Thailand Institute of Nuclear Technology, 16 Vibhavadi Rangsit Road, Chatuchak, Bangkok 10900, Thailand)

2:00 PM Determination of Arsenic in Soil, Vegetables and Hair in Khoa Ron Na - Suangchan subdistrict area, Amphoe Ronpibul Using Neutron Activation Analysis Technique

About 100 years ago after the discovery that the Khoa Ron Na -Suangchan subdistrict area, Nakhon Si Thammarat enriched with tin mineral in that area. The adverse effect due to tin mining process was the waste Arsenopyrite (FeAsS) which were left over in the tin mine till now. During the rainy season the leachate water that contained with the arsenic compounds in the form of a Arsenopyrite was washed out from the old mine into the surrounding areas. This leachate water can permeate into the canal, underground water, or shallow pond near by the vicinity or villager water resources. So, the poisonous Arsenic will be a part of drinking water or food chain for the Khoa Ron Na -Suangchan subdistrict area people. When the arsenic substance is stored within the human body for a long period of time, this can cause a skin cancer or other health symptom as well. The objective for this project focus on how to measure the small amount of Arsenic that contains in the soil, water, vegetable, and hair samples of people who settled in the Khoa Ron Na - Suangchan subdistrict area by using the Instrumental Neutron Activation Analysis (INAA) technique. This technique can identify both the qualitative and quantity of Arsenic (As) element that contain in the collecting samples by bombarding the sample with thermal neutron via 75As(n, gamma)76As nuclear reaction. In order to identify the As in the samples, the gamma rays at energy of 559 keV from As-76 with a half life of 26 hours was measured using Gamma ray spectrometer that equipped with HPGe detector. The quantitative analysis of As element in the samples was also obtained via comparative study between the net photo peak spectrum area of 559 keV for both standard and samples materials. The results show that accumulated arsenic in soil, vegetable and hair samples of people who settled in the Khoa Ron Na - Suangchan subdistrict area are in the range of 27.7-101.3 ppm, 2.5-16.1 ppm,.and untraceable, respectively.

Speaker: Ms Pattarawadee Maijan (Department of Physics, Faculty of Science, Prince of Songkla University, Hatyai Campus, Songkhla 90110, Thailand)

2:00 PM Developing and demonstrating the investigation of fingerprints on a glass surface by using digital holography technique.

In this research, a technique of digital holography has been applied to investigation of latent fingerprints on a surface of clear transparent glass plate. In this technique, a CCD camera is put at the image plane instead of photographic film in typical holography. In our technique, a Michelson interferometer has been setup for splitting a laser beam from a semiconductor laser to an image bearing beam and a reference beam for recording a hologram. By using a numerical technique for reconstructing record images from the CCD camera, a sharp result images and their details have been shown. The benefit of this technique may be improved for investigating a fingerprint on the surfaces of different kinds of construction materials such as woods, ceramics, or metals in the future.

Speaker: Ms Thong-on Thanyarat (Department of Physics, King Mongkut’s Institute of Technology Ladkrabang, Bangkok 10520, Thailand)

2:00 PM Development and Dose Evaluation of Natural Topaz for Dosimeter Radiation

In the present work, natural colourless topaz from Pakistan were irradiated gamma ray at different dose from 50-400 Gy. The samples were characterized by thermoluminescence (TL) and electron spin resonance (ESR) spectroscopy. The TL results showed that the luminescence center of topaz was appeared at 150 and 225 C. The intensity of TL was increased with increased radiation dose. The ESR signals with g = 1.966 and 2.012 due to Ti${}^{3+}$ and (AlO${}_4$)${}^-$ centers, respectively and increased with radiation dose. Percent error of evaluated dose from TL and ESR signals were 8 and 3, respectively. This study showed that the topaz can be used a radiation dosimeter.

Speaker: Dr Ekachai Hoonnivathana (Department of Physics, Faculty of Science, Kasetsart University, Bangkok, Thailand)

NUC_08.pdf

2:00 PM Development of C-shape Dipole Electromagnet as an Electron Energy Spectrometer

A dipole magnet is one of important components in particle accelerators. It can be used to bend the charged particle beam with desired deflection angle and direction. Moreover, it can be used as an energy spectrometer. This research focuses on development of a dipole electromagnet for measurements of energy and energy spread of electron beams that produced by the linear accelerator at the Plasma and Beam Physics Research Facility, Chiang Mai University. The main purpose of the research is to develop a dipole magnet with the deflecting angle of 60 degree for the electron beams with a maximum energy approximately 10 MeV. Two well-known computer programs Poisson and Radia are used to simulate 2D and 3D models, respectively. The optimized magnet prototype has a C-shape, which is convenient for installation in the accelerator beamline. It has a gap between the magnetic poles of 2.2 cm and can produce magnetic fields with the maximum magnetic fields intensity up to 0.35 T. The magnetic field deviation from the maximum value is less than 0.5 percent. To obtain the magnetic field value and deviation as required, the two conducting coils must have 1,300 winding turns with a maximum applied current of 5 A. This work has been supported by the CMU Junior Research Fellowship Program, and the Department of Physics and Materials Science, Faculty of Science, Chiang Mai University.

Speaker: Mr Nuntawuth SUDLOY (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University 50200)

2:00 PM Development of MeV Carbon-ion PIXE

In development of MeV heavy-ion particle induced X-ray emission (PIXE) technology which has been demonstrated to be superior to conventional light proton PIXE owing to larger cross sections, MeV carbon-ion PIXE was tested and studied for availability and cross sections. The relatively low ion energy range around 1 MeV for C-ion PIXE had never been investigated before. In the work, C-ion PIXE at ion energy around 1 MeV was firstly tested and demonstrated to be available at our 1.7-MV tandem accelerator and its beam line. In measurement of the cross sections for the MeV C-ion PIXE, 0.8, 1.0 and 1.2 MeV C-ion beams were applied to analyze materials of Si, Fe, Cu, Zn and Au and the spectra were compared with spectra of 1.0- and 2.0-MeV proton PIXE. Results showed that at the same low ion energy of 1 MeV, C-ion PIXE yields were significantly higher by orders than those of proton PIXE which were actually negligible, demonstrating the former significantly more sensitive than the latter. With the 2-MeV proton PIXE cross sections used as the reference, the MeV C-ion PIXE cross sections were calculated. An interesting trend of the cross section against the atomic number Z showed that the cross sections of MeV C-ion PIXE compared with those of proton PIXE for the analyzed materials had a transition around Cu. For lower Z the former was higher than the latter, while for higher Z the former was lower than the latter, indicating MeV C-ion PIXE more sensitive in detecting lower-Z elements. Detailed experimental and calculating methods as well as discussions are reported in the presentation.

Speakers: Mr Chaiyon Chaiwai (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiangmai, 50200, Thailand), Dr Udomrat Tippawan (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiangmai, 50200, Thailand), Dr Yu Liangdeng (Thailand Center of Excellence in Physics, Si Ayutthaya Road,Bangkok 10400,Thailand)

notes SPC2015_Abstract_Chaiyon_Chaiwai.doc SPC2015_Abstract_Chaiyon_Chaiwai.pdf

Paper FullpaperSPC2015_Chaiyon_Chaiwai.docx FullpaperSPC2015_Chaiyon_Chaiwai.pdf

Poster SPC_2015_Poster_Chaiyon_Chaiwai.pdf

2:00 PM Dye-sensitized solar cell based on hydrothermally deposited NiS counter electrode

NiS films were prepared by a hydrothermal technique on FTO glass substrates. The NiS films were used as a counter electrode electrodes of dye-sensitized solar cell. The dye-sensitized solar cell base on NiS exhibited performance with the energy conversion efficiency of 8.33%, open-circuit voltage of 0.74 V, short-circuit current of 16.23 mA.cm$^{−2}$, and fill factor of 0.69 under full sunlight illumination (100 mW.cm$^{-2}$, AM 1.5G). This performance is close to the devices using platinum as the counter electrode (8.48% ).

Speaker: Mr Wasan Maiaugree (Department of Physics, Faculty of science, Khon Kaen University, Khon Kaen, THAILAND)

2:00 PM Dye-sensitized solar cell using a natural dye extracted from Artocarpus lacucha

Dye-sensitized solar cells (DSSCs) is fabricated from a combination of relatively popular materials containing nanocrystalline TiO${}_2$, electrolyte solution containing I${}^−$/I${}^{3-}$ redox mediator, counter electrode, and natural dye. In this work, the natural dye extract from Artocarpus lacucha with methanol solvent as sensitizers. The photo to current conversion efficiency (η = 0.69%) was obtained by Artocarpus lacucha under AM 1.5 illumination. The short circuit photo-current density (Jsc), open circuit voltage (Voc) and fill factor (FF) are 2.01 mAcm${}^{-2}$, 0.57V and 0.60, respectively.

Speaker: Mr Seksan Lowpa (Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand.)

2:00 PM Effect of Gd substitution for La on the structure and magnetic properties of the La${}_{1-x-y}$Sr${}_x$Gd${}_y$MnO${}_3$ nanoparticle

Magnetic nanocrytalline of La${}_{1-x-y}$Sr${}_x$Gd${}_y$MnO${}_3$ (LSGM) with $y$ = 0, 0.05, 0.10, 0.15 and 0.20 are synthesized by a thermal-hydro decomposition method at 800 ºC in air for 6 h. All samples are characterized by TG-DTA, XRD, SEM and VSM. The XRD result shows that all the prepared samples have perovskite structure with rhombohedral phase. The crystalline sizes are in the range of 18.1 – 21.1 nm, which increases with decreasing Gd content (y value). The SEM images of prepared samples show the spherical nanoparticles shape with agglomeration of particles. The VSM result shows soft-ferromagnetic behavior for all samples with the magnetization (M) value of 9.3– 34.6 emu/g. The M value decreases with increasing Gd content. The substitution for La by Gd with a smaller ionic size than La usually leads to a decreases of lattice parameters and decreases of crystalline sizes. The decrease of magnetization value with increasing Gd concentration associated distortion structure with high mismatch factor (σ2).

Speaker: Ms Saowalak Saengplot (Program of Materials Science and Nanotechnology, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand)

2:00 PM Effect of post mold cure ramp down temperature on internal package stress for IC plastic packages.

This research studied an effect of ramp down temperature to integrated circuit (IC) packages after completed post mold curing in IC packaging process. Post mold cure process is so important to make a completed epoxy molding compound (EMC) due to cross linking to enhance microstructure of compound stiffness. Temperature is a factor effect to EMC base on the coefficient of thermal expansion. The ramp down temperature of post mold curing can change microstructure of compound in term of stress inside the package. In experiment, the ramp down temperatures were varied to check the effect of internal stress due to temperature. The ramp down temperature were varied from 175 C$^{\circ}$ until room temperature (25 C$^{\circ}$) and analyzed the stress inside the packages by reliability testing after take the test samples out from the oven cure. The results showed that for TSSOP package the ramp down temperature at 175 C$^{\circ}$, 150 C$^{\circ}$, 125 C$^{\circ}$, 100 C$^{\circ}$, 75 C$^{\circ}$, 50 C$^{\circ}$ and 25 C$^{\circ}$ to reveal internal stress of the package after completed post mold cure. For SOIC and SOT23 the opposite way, the ramp down temperature of all these temperatures did not reveal stress inside EMC.

Speaker: Anan SUKANTHARAT (Central Engineering Department, UTAC Thai Limited, Bangkok, THAILAND 10260)

Poster SPC_2015_Anan.pdf

2:00 PM Effects of Substrate Materials on Structural and Magnetic Behaviors of Co-Cu Film Prepared by RF-sputtering

Co-Cu film with thickness of 312 nm on different substrates (glass, A-PET, C-PET, W-PTFE and B-PTFE was deposited by RF-sputtering. XRD confirms that all deposited films show Co (HCP) phase in 220 plane, Cu (FCC) phase in 111 plane and Co-Cu (FCC) phase in 111 plane. Intensity of the peak is obviously dependent on substrate material. The highest and lowest peak intensities were observed on the films deposited on C-PET and A-PET substrate, respectively. VSM result reveals that all sputtered Co-Cu films display ferromagnetic phase at room temperature. The maximum and minimum saturation magnetizations in both parallel and perpendicular measurements were observed on the film deposited on B-PTFE and glass substrates, respectively. The result implies that the structural and magnetic properties of sputtered Co-Cu film can be importantly improved by the material substrate.

Speaker: Ms Sirapat Seepromting (Department of Physics, Faculty of Science, Kasetsart University, Bangkok, Thailand 10900)

2:00 PM Electrical Resistivity of Ti-Ga-P Thin Films Synthesized by Asymmetric Bipolar Pulsed-DC Magnetron Sputtering

The electrical resistivity of thin films of Ga-P-Ti alloys, deposited on glass substrates by an asymmetric bipolar pulse-dc magnetron sputtering method under Ar atmosphere, has been investigated. The sputtering targets containing compacted GaP powder and metallic titanium sheet with the surface ratio GaP:Ti of 8:1, 5:1, 2:1 and 1:1 were employed. The electrical resistivity of the deposited thin films was measured using the standard van-der-pauw four probe technique under dark and illumination with white light of 70,000 lux conditions. It was found that, under dark condition, the electrical resistivity increases from 7.547E-1 to 9.469E+1 $\Omega$.m for the films deposited from the target having GaP:Ti of 8:1 and 5:1, before sharply reduces to 1.538E-4 and 3.899E-5 $\Omega$.m for the films obtained from the targets having GaP:Ti of 2:1 and 1:1, respectively. The electrical resistivity measured under the lighting condition shows the similar trend. The results indicated that the thin film from the targets having GaP:Ti of 8:1 and 5:1 are semiconductor-like while those from the targets having GaP:Ti of 2:1 and 1:1 are metal-like. The observed behaviors agree well with those found from optical property measurement carried out early. However, the changes of electrical resistivity in responses to lights are inconclusive.

Speaker: Mr Tanachai Ponken (Departmet of Physics, Faculty of Science, Khon Kaen University, 40002, Thailand)

2:00 PM Estimation Density and Viscosity of Ethyl-Biodiesel from Saponification Number and Iodine Value

Density and viscosity are an important physical property of biodiesel. In this work, proposed a single empirical equation can be estimated without the prior knowledge of the density and viscosity of an individual fatty acid ethyl ester, an empirical approach for estimation the density and viscosity of ethyl-biodiesel are correlated to saponification number (SN), iodine value (IV) and temperature. Data available in literatures are used to validate, and support the speculations derived from the proposed equation. The proposed equations are easy to use and the estimated density and viscosity values of ethyl-biodiesel at different temperatures agree well with the literature values. It is shown that it can estimate the densities and viscosities of ethyl-biodiesel with average deviations were 0.28% and 4.20%, respectively.

Speaker: Dr Suriya Phankosol (Department of Industrial and Technology Management, Faculty of Science and Technology, Bansomdejchaopraya Rajabhat University, Bangkok 10600, Thailand)

2:00 PM Fabrication of 3D-hybrid (TNT/Au) Nanoarrays As Substrate for Surface-Enhanced Raman Scattering Detection

Surface-enhanced Raman scattering (SERS) substrates have been achieved via simultaneous assembled gold nanoparticles (AuNPs) onto the titanium dioxide nanotube (TNT) template. The highly ordered TNT template based on the sputtered Ti thin film was anodized at 60 V 25 ^oC in ethylene glycol mixed with 0.3 wt% of ammonium fluoride diluted by 2 vol% H₂O. The effect of HAuCl₄ concentration among 0.1 to 1 mM on the Au particle size was investigated by mean characterization method as field-emission scanning electron microscope (FE-SEM). According to FE-SEM photograph, it clearly observes that the Au particle size gradually increases as the HAuCl₄ concentration was increased. Finally, in order to examine the SERs activity the methylene blue (MB) was performed as the probe molecules. The Au particle plays the important role on the SERs performance.

Speaker: Mr Sukittaya Jessadaluk (Department of Physics, Faculty of Science and Technology, Thammasat University, Pathumthani, 12121, Thailand)

2:00 PM Formation mechanism and mechanical properties of titanium oxynitride (TiO$\rm _x$N$\rm _y$) thin films deposited by reactive dc magnetron sputtering

In this work, the formation of titanium oxynitride ($\rm TiO_xN_y$) thin films during a reactive dc magnetron sputtering process was investigated. $\rm TiO_xN_y$ thin films were deposited on glass substrates from Ti target at different sputtering power, using O$_2$ and N$_2$ as reactive gases. The structural, surface morphology, chemical-bonding and mechanical properties were analyzed by grazing incident x-ray diffraction (GIXRD), atomic force microscope (AFM), X-ray photoelectron spectroscopy (XPS), and nano-indentation techniques, respectively. The GIXRD spectra show the amorphous structure and polycrystalline structure with the increasing of the sputtering power. We found that the peaks shift of TiN structure to the higher angle due to the oxygen incorporation into the crystal lattice. The roughness of the films increases along with the increasing of sputtering power. From the XPS analysis reveals the formation of TiO$_2$, $\rm TiO_xN_y$ and TiN by considering the Ti-2p, O-1s, and N-1s XPS spectra of the films. These results indicate that the sputtering power affects the formation of the $\rm TiO_xN_y$ thin films. The mechanical properties i.e. hardness and elastic modulus obtained by nano-indentation are in the range of 5.97-12.63 GPa and 85-120 GPa, respectively. The mechanical property of the films relates the crystal structure and the chemical states. The increasing of sputtering power enhances the formation of titanium nitride structure and leads to achieve the mechanical property.

Speaker: Dr Rachsak Sakdanuphab (College of Data Storage Innovation, King Mongkut’s Institute of Technology Ladkrabang, Bangkok, THAILAND 10520)

2:00 PM Groundwater investigations in Patiw, Chumphon

Groundwater is important natural resources and vital for many people. In area of Patiw district, Chumphon province has a lot of palm forests. Local people use groundwater for grow their plant. The sedimentary rock in study area consists of mostly mud-gravel sediment rock, siltstone in the west and mostly hill is limestone. The aim of this project is to find and locate the location of groundwater in Patiw district, Chumphon province by geophysical survey methods. The method use to find and locate groundwater is Electrical survey method. Vertical electrical sounding (VES) surveys were carried out at three locations using Schlumberger array and Imaging electrical surveys (2-D Survey) were carried out at four locations. The field data has been primarily interpreted using inversion. Geophysical model have been prepared based on resistivity profile, geology data and well data. The result shows that there are two groundwater areas, the first area is locate on 160-320 m on Line 1(2-D) with depth 60-120 m and the second area is locate on 700-1000 m on Line 1(2-D) with depth 50-120 m. The groundwater is water from limestone aquifer. There are two possible drilling locations, the first position is locate on 240 m on Line 1(2-D) with depth 90 m and the second position is locate on 900 m on Line 1(2-D) with depth 120 m.

Speaker: Mr Kraipat Petrit (Department of Physics, Faculty of Science, Prince of Songkla University, Songkhla, Thailand, 90112)

2:00 PM Growth of graphene triangles and stripes on Si-face SiC (0001)

Graphene on silicon carbide (SiC) has a potential for technological application devices. The electronic properties of graphene in nanometer scale are significantly influenced by morphology, edge structures and so on. In this report, we have studied the growth of the epitaxial graphene on silicon-terminated SiC (0001) by annealing the SiC substrates in ultra-high vacuum and various types of inert gas (He, Ne and Ar) at pressure of 0.05 atm. Striped graphene islands are often observed at the step edge of all samples but the triangular graphene islands are only found on the SiC surfaces which contain wide terraces (> $\sim$ 1.5 micrometer). Shape of graphene islands and zigzag edge type of triangular graphene islands were revealed by scanning electron microscope and reflection high-energy electron diffraction. Moreover, the growth mechanism of the triangular graphene islands is emphasized.

Speaker: Dr Akkawat Ruammaitree (Department of Physics, Faculty of Science and Technology, Thammasat University, Pathum Thani, THAILAND 12121)

2:00 PM Hybrid bulk-heterojunction solar cells based on poly(3-hexylthiophene) and ZnO nanostructures

Photovoltaic performance of hybrid ZnO nanorods (ZnO NRs)/ polymer solar cells is enhanced through the addition of ZnO nanoparticles (ZnO NPs) into poly(3-hexylthiophene) (P3HT) absorber layer. A mixture of ZnO NPs:P3HT, acting as photo-active layer, is coated onto ZnO NRs, serving as electron acceptor, by spin-coating technique. The ZnO NPs/P3HT blend is able to infiltrate into the interrod space, as confirmed by field emission scanning electron microscopy (FE-SEM) observation. The ZnO NPs/P3HT (13% by volume) blend-coated ZnO NR device shows the maximum power conversion efficiency of 1.02%, which is higher than that of the pristine ZnO NRs/P3HT device (0.26%). The enhancement is mainly attributed to the larger ZnO/P3HT interface area and higher charge collection, as observed by an increase of the external quantum efficiency.

Speaker: Dr Pipat Ruankham (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai, THAILAND 50200)

2:00 PM Incorporation of Cu-Se to Cu-Ga-In precursors for the fabrication of CuIn$_1$$_-$$_x$Ga$_x$Se$_2$ thin film solar cells

Cu-In-Ga (CIG) metallic precursor thin films were fabricated by sequential depositions of Cu-Ga and In on Mo-coated soda lime glass (SLG) substrates. Due to low melting point of In and adhesion issues of the CIG metallic precursor, the substrate temperature was optimized for the depositions of In and Cu-Ga layers. It was found that the sequence of the depositions of Cu-Ga and In affected the formation of alloying precursors. In this study, $\rm CuIn_{1-x}Ga_xSe_2$ (CIGS) thin films were obtained by the co-evaporation of Cu-Se during increasing the temperature of the CIG metallic precursors from 150°C to 450°C, and followed by vacuum annealing at 450°C. The duration time of the Cu-Se flux and the annealing processes were among important varying parameters. The formation and the chalcopyrite phase of the CIGS layer were determined by FESEM and XRD, respectively. The CIGS thin film solar cells were also fabricated and tested for their I-V characteristics as well as quantum efficiency measurements (QE) to observe their spectral responses. The best efficiency of the CIGS solar cells obtained from the absorber fabricated by this method was 13.2%.

Speaker: Ms Kwanruthai Butsriruk (Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok, THAILAND 10330)

2:00 PM Increasing of wettability of silk powder using the atmospheric pressure plasma jet treatment

In this research, the surface of sericin silk powder was treated using the atmospheric pressure plasma jet (APPJ). The plasma was generated with the argon and oxygen flow rate of 1.6 slm and 0.02 slm respectively. The stable discharge occurs with the RF frequency of 76.7 kHz, the plasma current of 140 mA and the RF power of 5.31 W. The silk powder before treated has the initial water contact angle of 75.7° and the absorption time of 29 s. Although the initial water contact angle decrease a little bit to 60°-70° after 45 s of treatment but the absorption time also clearly decreased to 5-7 s. This result shows that the plasma exposure can increase the surface free energy and also increase the hydrophilic property of silk powder. Moreover we found that the absorption time of silk powder has no change after exposure in the ambient air. This indicates that the active radicals from the plasma can be adhered tightly on the silk surface. Result from the SEM image of silk powder before and after treated shows that the silk powder looks like fiber with the diameter of 6-8 µm and does not be destroyed with the plasma beam. This plasma jet can be useful for the treatment of the objects having various structures and also could be applied in the cosmetic industries.

Speaker: Ms Sakuntala Seehaburan (Department of Physics, Faculty of Science, Mahasarakham University, Mahasarakham 44150, Thailand)

2:00 PM Influence of Asymmetric Electromagnetic Field Distributions in an RF-gun on Electron Beam Properties

The electron source of the linear accelerator system at the Plasma and Beam Physics Research Facility, Chiang Mai University, is a thermionic cathode radio-frequency (RF) electron gun. The gun is a pi/2-mode standing wave structure composing of two S-band RF accelerating cells and a side-coupling cavity. The 2856 MHz RF wave is transmitted from the klystron to the RF-gun through a rectangular waveguide input-port. The RF input-port and the side-coupling cavity are the cause of asymmetric electromagnetic (EM) field distributions inside the gun. This leads to an asymmetric beam transverse shape and the increase of the beam emittance at the gun exit. The problems can be enlarged when the beams are transported from the RF-gun through the whole accelerator system, which consists of an alpha magnet, a travelling wave linear accelerator, magnet elements and related beam diagnostic components. To investigate the influence of the asymmetric EM fields on the electron beam properties at the experimental station, beam dynamic simulations are performed by using the computer code PARMELA. The input 2D and 3D EM field distributions are obtained from the RF modeling programs SUPERFISH 7.19 and CST Microwave Studio 2012. Simulation results by using both 2D and 3D field distributions are compared and reported in this contribution. This work has been supported by the CMU Junior Research Fellowship Program, the Development and Promotion of Science and Technology talents project (DPST), and the Department of Physics and Materials Science, Faculty of Science, Chiang Mai University.

Speaker: Mr Wuttiphong Thongpakdi (Department of Physics and Materials Science, Facility of Science, Chiang Mai University 50200)

Poster Poster-W.Thongpakdi.pdf

2:00 PM Influence of thickness reduction for CGS/CIS/CGS absorber layer on solar cell performance

Typical $\rm CuIn_{1-x}Ga_xSe_2$ (CIGS) thin film solar cells on soda-lime glass (SLG) substrates consist of six different layers of thin film materials, i.e. SLG/Mo/CIGS/CdS/i-ZnO/ZnO(Al)/Al-grids. One of the commonly used deposition techniques for the CIGS thin films is the three-stage deposition process. However, the deposition of CIS/CGS bilayers and CGS/CIS/CGS trilayers were employed for the fabrication of CIGS thin film solar cells in order to reduce the materials and times used in the process and induce the non-uniformity of In and Ga due to their different diffusivities that could lead to band gap grading. The substrate temperature was kept constant at 560°C throughout the deposition. The typical thickness of the CIGS was approximately 1.8 μm. The thickness reduction of CGS/CIS/CGS layers was investigated from 1.8 μm down to 0.5 μm. The efficiencies of the devices fabricated from the CIS/CGS and CGS/CIS/CGS layers, both with 1.8 μm thick, showed the maximum value of 12.8 % and 15.5%, respectively. The thickness reduction showed slightly loss in the short-circuit current and the open-circuit voltage resulting in the reduction of the device efficiencies. For example, when the thickness is approximately reduced by 55%, the device efficiency is decreased by 15%. The external quantum efficiency measurements were performed to compare the spectral response of the devices. The cross sectional SEM images of the CIGS devices are shown and compared for their corresponding efficiencies. In addition, XRD and EDS were used to indicate and investigate the non-uniformity distribution of In and Ga in the CIGS absorber layers.

Speaker: Ms Busarin Noikaew (Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok, THAILAND 10330)

2:00 PM Investigating spectral response of CuIn$\rm _{1-x}$Ga$\rm _x$Se$_2$ thin film solar cells by quantum efficiency measurements

Quantum efficiency (QE) measurement is one of several methods used to investigate solar cell performance, especially the carrier collection. It indicates the amount of photogenerated current produced when a solar cell is illuminated by photons of a particular wavelength. In this study, a quantum efficiency measurement system was constructed and the $\rm CuIn_{1-x}Ga_xSe_2$ (CIGS) – based thin film solar cells with different growth conditions were characterized. The results show an influence of differences in band gap energy on photo-current collection. The changing in collected current and absorption edges can be observed. In addition, quantum efficiency measurement is used to identify the properties of each thin film layer comprising the devices. The current leakage due to a defective p-n junction leads to sharp drops in QE spectrum at some particular wavelengths. However, not only the basic quantum efficiency measurement was used but the lock-in amplifier technique was also applied to this system in order to enhance signal-to-noise ratio. The results of both techniques were compared and exhibited an improvement of data acquisition.

Speaker: Mr Supathat Sukaiem (Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok, THAILAND 10330)

2:00 PM Laser Welding with Inert Gas of Various Jewelry Designs

In Jewelry production, the laser welding has become an essential tools. It has been used for repair and upgrading the design. The control parameters which are laser parameters, welding method, inert gas, and operator skills were studies in various jewelry designs both silver and gold. Each jewelry design required different laser parameters and welding methods. Inert gas help improving the appearance of the joint. Moreover, mechanical strength of laser welding was investigate.

Speaker: Dr Sukanya Tachatraiphop (School of Laser Technology and Photonics, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand)

2:00 PM Measurement of Specific Activities of Natural Radionuclides (${}^{40}$K, ${}^{226}$Ra and ${}^{232}$Th) in Beach Sand Samples from Soisawan Beach of Thepha District in Songkhla Province (Thailand)

Specific activity of natural radionuclides (${}^{40}$K, ${}^{226}$Ra and ${}^{232}$Th) in 50 beach sand samples collected from Soisawan beach of Thepha District in Songkhla Province, Thailand, have been measured and analyzed. Experimental results were obtained by using a high–purity germanium (HPGe) detector and gamma spectrometry analysis system at Nuclear and Material Physics laboratory in Department of Physics, Faculty of Science, Thaksin University, Songkhla Campus. Gamma ray radioactive standard sources ${}^{60}$Co, ${}^{137}$Cs and ${}^{133}$Ba were used to calibrate the measurement system. The KCl and two well-known reference materials (IAEA/RGU-1 and IAEA/RGTh-1) obtained from the International Atomic Energy Agency were also used to analyze and compute the specific activities of ${}^{40}$K, ${}^{226}$Ra and ${}^{232}$Th in every samples. It was found that specific activities ranged from 512.00 – 3955.88 Bq/kg for ${}^{40}$K, 20.11 – 83.18 Bq/kg for ${}^{226}$Ra and 3.75 – 94.68 Bq/kg for ${}^{232}$Th with mean values of 1983.32 ± 187.39, 42.67 ± 4.00 and 37.98 ± 2.71 Bq/kg respectively. Furthermore, absorbed dose rate in air (D), radium equivalent activity (Raeq), external hazard index (Hex), and annual effective dose rate of this area were evaluated by using the mean values of specific activities of ${}^{40}$K, ${}^{226}$Ra and ${}^{232}$Th. Moreover, the experimental results were also compared with Office of Atoms for Peace (OAP) research data, Thailand and global radioactivity measurement and evaluations.

Speaker: Ms MURNEE DAOH (Department of Physics, Faculty of Science, Songkhla Rajabhat University, 90000, Thailand)

2:00 PM Measurement of Specific Activity of Natural (${}^{40}$K, ${}^{226}$Ra and ${}^{232}$Th) and Anthropogenic (${}^{137}$Cs) Radionuclides in Bottled Drinking Water in Phuket Province (Thailand) Using Gamma Ray Spectrometry Technique

This research aims to study the specific activity of natural (${}^{40}$K, ${}^{226}$Ra and ${}^{232}$Th) and anthropogenic (${}^{137}$Cs) radionuclides in bottled drinking water from different manufacturers in local stores located in Phuket province, Thailand. Totally 30 samples of bottled drinking water (5 liters) were randomly collected and prepared. All of water samples were boiled at 100 oC and evaporated into 1 liter. Specific activity of natural and anthropogenic radionuclides in all prepared water samples were measured and determined using a low background high-purity germanium (HPGe) detector and gamma ray spectrometry analysis system. The gamma ray radioactive standard sources from Office of Atoms for Peace (OAP) which is SH-424, were also used to analyze and compute all of specific activities of ${}^{40}$K, ${}^{226}$Ra, ${}^{232}$Th and ${}^{137}$Cs. The measuring time of each sample is 21,600 seconds. It was found that specific activities of ${}^{40}$K, ${}^{226}$Ra, ${}^{232}$Th and ${}^{137}$Cs ranged from < 0.20 - 0.41 Bq/L, 0.37 - 2.11 Bq/L, < 0.11 - 1.30 Bq/L and < 0.27 - 1.82 Bq/L with mean values of 0.24 ± 0.09 Bq/L , 1.13 ± 0.2 Bq/L, 0.61 ± 0.21 Bq/L and 1.09 ± 0.36 Bq/L, respectively. Moreover, the experimental results were also compared with Office of Atoms for Peace (OAP) research data and some acceptable values proposed by UNSCEAR.

Speaker: Mr Auttachai Thawonsuwan (Faculty of General Education, Rajamangala University of Technology Srivijaya, A. Muang, Songkhla, 90000, Thailand)

2:00 PM Neutron Attenuation Performance of Barite Concrete Samples

For the radiation safety purpose, a mixed concrete wall setup is being designed and tested at Thai Research Reactor. In this work, using barite as the main aggregate, the concrete samples, which were meant primarily to be used as gamma shielding materials, were evaluated for their neutron radiation attenuation properties. A 50-Ci Am-Be was used as the neutron source and a BF3 was used to measure the transmitted neutrons. The results between different mixtures are reported and discussed.

Speaker: Mr Jatechan Channuie (Thailand Institute of Nuclear Technology)

2:00 PM Numerical investigation of transmission of graphene based one-dimensional photonic band-gap structure

In this study, a transmission property of one-dimensional photonic band-gap (1D-PBG) structure consisting of two periodically alternated dielectric layers, which the first layer is ordinary dielectric material and the second layer is dielectric material containing graphene multilayer system inside the layer, have been numerically investigated by using transfer matrix method. The numerical results give the transmission spectrum for both transverse electric (TE) and transverse magnetic (TM) polarization and also show that the position of photonics band-gap locating in terahertz (THz) region. In addition, we exploit that the width of band-gap can be tuned by the properties of graphene layer. Finally, the proposed graphene based 1D-PBG structure can be designed as an efficient passive filter for electromagnetic wave in THz wavelength region.

Speaker: Dr Surawut Wicharn (Department of Physics, Faculty of Science, Srinakarinwirot University, Bangkok, THAILAND 10110)

2:00 PM Optical phase conjugate from cerium doped barium titanate at wavelength 632.8 nm

In this thesis, optical phase conjugate beam with the using of different resonator configurations has been investigate. Two types of SPPC resonators were selected to use, the first one is linear resonators formed by crystal surface and the other one is linear resonators formed by single mirror and a photorefractive crystal. In our experiment, cerium doped barium titanate crystal3(Ce:BaTiO)and He-Ne laser with wavelength of 632.8 nm have been used. From the results of both cases, the angle of the incident beams is optimum at 37.23 degree and 37.44 degree respect to the normal line of the surface that parallel to the c-axis of the crystal. The generating time of OPC beam are 17 minutes and 15 minutes for the first and second type resonators, respectively. The reflection ratios are equal to 35.37910% and 0.240%for the first and second type resonators, respectively (the second type resonators could provide better reflection ratio).

Speaker: Ms Knittha Sidakum (Department of Physics, King Mongkut’s Institute of Technology Ladkrabang, Bangkok 10520, Thailand)

2:00 PM Optical property of titanium-doped ZnO thin film prepared using dc magnetron sputtering technique

In this research, the ceramic target with a mixture of ZnO (99.9% purity) and titanium (99.99% purity) was sintered at 1,000 ${}^{\circ}$C for 4 hour. The content of Ti added to the ZnO target 10 wt.%. The diameter of the target was 51 mm and the thickness was 5 mm. The titanium-doped ZnO (TZO) films were deposited on glass substrates using the DC magnetron sputtering at room temperature. The deposition time was varied from 30 min to 90 min with the sputtering power of 150 W. When the deposition time of 30 min, the TZO film has the lowest sheet resistance of 72.2 /sq corresponding to the thickness of TZO films (determined using SEM image) of 1.2 m. The visible transmittance increased above 90% with the deposition time of 75 min corresponding to the optical energy gap of 3.87 eV which obtained using the Tauc plot method.

Speaker: Ms Lukkana Srisoy (Department of Physics, Faculty of Science, Mahasarakham University, Mahasarakham, THAILAND)

2:00 PM Phase imaging of cancer cell using compressive sensing apply to digital holography

The aim of this research is to develop a quantitative phase imaging system based on digital holography for distinguishing cancer cells and ordinary cells. For improving the efficiency of the imaging system, a computer program, which has been used for digital hologram reconstruction, is modified by integrating with an algorithm based on compressive sensing theorem. The feature of compressive sensing algorithm is the ability of recovery signals from the sparsity of sampling signals. Therefore, the phase imaging system with compressive sensing algorithm is providing an accurate cancer cell reconstruction from a relative small number of encoded signal sample cells.

Speaker: Ms Chantira Boonsri (Department of Physics, King Mongkut’s Institute of Technology Ladkrabang, Bangkok 10520, Thailand)

2:00 PM Postharvest longevity of Longkong fruits by waxing with Chitosan solution and incorporated with gamma irradiation

Since Chitosan is the substance that can be extracted from shrimp shell, easy to find, and cheap in the Southern region of Thailand. In addition, it can prolong the life of fruit after harvest with the qualification of high cation that can binding to gram-negative bacteria. It can cause bacteria to lose balance in chemistry and eventually die. Moreover, it can also eliminate many types of microorganisms. Therefore, this project uses Chitosan solution with the different concentration in order to prolong the life of Longkong in conjunction with gamma ray, gamma ray can destroy microorganisms that are the cause of spoilage of fruit. This experimentation records the result with photography and analyzes the results by Adobe Photoshop Cs6 program by measuring the RGB red spectrum. Because the red spectrum can show a linear correlation between time and spectrum intensity better than green and blue colors. Beside chitosan solution, this experiment also irradiated the Longkong fruit with gamma radiation dose In order to find the concentration of Chitosan solution and dose of Gamma ray that is appropriate to prolong the life of fruit after harvest. The preliminary experiment found that the waxed Longkong with chitosan solution at 0.5%(V/V) in acetic acid 0.5%(V/V) concentration can extend the life of Longkong longer than other concentrations and than other Longkongs that are not coated by chitosan solution for 7 days. In the case of gamma irradiation to Longkong, the dosage quantity of gamma ray that used in the experiment is not appropriate for prolonging the life of Longkong because it Dok Mai Si Thong, a similar result is also occurred to the mango fruit that made the mango tissue soft faster than the fruit has not been irradiated.

Speaker: Ms Soraya RUANGDIT (Department of Physics, Faculty of Science, Prince of Songkla University, Songkhla, THAILAND 90110)

2:00 PM Prediction of fusion power in DEMO reactor under various scenarios using integrated predictive modeling code

In this study, a prediction of the ratio of thermal power output to fusion power input (Q value) of the DEMO reactor under various scenarios using integrated predictive modeling code is studied. DEMO is the first fusion reactor designed to generate electric power, using the knowledge gained from the International Thermonuclear Experimental Reactor (ITER). DEMO has been proposed to be built in various countries, such as Japan, Korea, China, Russia, India, and the EU. In this study, the core transport is described using a combination of neoclassical transport model and anomalous core transport model. The simulations are carried out for plasma temperature and density profiles using the BALDUR code.

Speaker: Ms Jiraporn PROMPING (Thailand Institute of Nuclear Technology, Bangkok, Thailand, 10900)

2:00 PM Pressure distribution of the SPS storage ring

Ultra-high vacuum is a key requirement that determines electron beam quality and lifetime for an electron accelerator complex. In operation of the Siam Photon Source (SPS), pressure distribution of storage ring has been monitored using a series of Cold Cathode Gauges (CCGs) installed in proximity to the vacuum pumps around the ring. Pressure between the CCGs was calculated based on the continuity principle of gas flow. Photon-stimulated gas desorption from synchrotron radiation was also taken into account. It was found that averaged pressure of the SPS storage ring is ≤1.0×10$^{-9}$ Torr, calculated at the beam current of 115 mA, the beam energy of 1.2 GeV and the photon dose of 2000 A⋅hr. Discussion will be made on the calculation results in comparison to the measured values. In addition, the latest results from three-dimensional simulation using Molflow will be presented.

Speaker: Prapaiwan Sunwong (Accelerator Technology Division, Synchrotron Light Research Institute (Public Organization) 111 University Avenue, Muang District, Nakhon Ratchasima, 30000 Thailand)

Poster 150515_SPC2015_Poster_2.pdf

2:00 PM Properties of Sputtered ZnO:Al Film on Flexible Substrates

Aluminum-doped ZnO (ZnO:Al) film was prepared by RF-sputtering on glass, A-PET, C-PET substrates. XRD confirms that sputtered ZnO:Al films shows a polycrystalline wurtzite structure with c-axis perpendicular to the substrate in (002) direction. The highest and lowest peak intensities were observed on the films deposited on glass and C-PET substrates, respectively. SEM result shows the difference of surface morphology of sputtered ZnO:Al film on A-PET, C-PET substrates. The film on A-PET substrate shows the columnar structure of the oval grain shape whereas the C-PET substrate displays the island structure of the spherical grain shape. EDS also confirms that the atomic percent of Zn element of the film on C-PET substrates is slightly higher than that on A-PET substrate. The average transmission in 900-1400 nm of the film on A-PET and C-PET substrates is about 80%. The averaged transmission in visible region of the film on A-PET and C-PET substrates is about 75% and 80%. It can be concluded that the structure, morphology and optical transmission of sputtered ZnO:Al film are substrate material dependent and the flexible material can be an appropriate substrate to improve the properties of deposited films.

Speaker: Pichai Sirisangsawang (Scientific Equipment Center, Faculty of Science, Kasetsart University, Bangkok, THAILAND 10900)

2:00 PM Pulsar navigation using Doppler Effect

Autonomous technology in space navigation is a key to explore the solar system and beyond. Current space navigation technology requires constant communication between spacecraft and ground-based stations with typical error about 4 kilometres per astronomical unit. Pulsars are fast rotating neutron stars. Having high precision (in order of microsecond) in their spin period (approximately second to millisecond), they can be perfect tools for space navigation. As the observed pulsar's spin period changes with the relative motion between the spacecraft and the pulsar (i.e. Doppler Effect), we can determine the spacecraft's velocity in pulsar's direction. Using of three or more pulsars, complete velocity information can be determined. Proof-of-concept simulations with three fake pulsars have been done with C programming, which is shown to be consistent. The results indicate that the error strongly depends on the position of the three pulsars. For example, the maximum error occurs when the three pulsar are in the same position.

Speaker: Jompoj Wongphecauxson (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand)

Paper spc2015.doc This paper has been writing in Linux. For some case, I also upload PDF version.

2:00 PM Pulsar Search with PMPS Monitoring Dataset

Pulsar search has always been one of the most active fields. It lets astronomers to discover new phenomena, which either challenge or confirm our current knowledge. The most-successful Parkes Multibeam Pulsar Survey (PMPS) has us to discover over a third of currently known pulsars. The long-term monitoring programme for PMPS pulsars has been initiated, which now contains over 35,000 observations from 785 sources. The PMPS monitoring dataset is suitable for pulsar search because: 1) the data is recorded in search mode; 2) the 15-arcmin Parkes’ pointing provides a good coverage of the galactic plane. In addition, its timespan of over ten years is also ideal for searching for time-variability and intermittency.

Speaker: Dr Phrudth Jaroenjittichai (National Astronomical Research Institute of Thailand,Chiang Mai 50200, Thailand)

2:00 PM Radiological Hazard Assessment and Radioactive Contour Maps in Surface Soil Samples Collected from Satun Province, Thailand

The specific activities of natural ($^{40}$K, $^{226}$Ra and $^{232}$Th) and anthropogenic ($^{137}$Cs) radionuclides in 135 surface soil samples collected from 7 districts in Satun province in the southern region of Thailand were measured and determined. Experimental results were obtained by using a high-purity germanium (HPGe) detector and gamma spectrometry analysis system. The KCL, IAEA/RGU-1, IAEA/RGTh-1 and IAEA/SL-2 reference materials were used to analyze the concentration of $^{40}$K, $^{226}$Ra $^{232}$Th and $^{137}$Cs in all samples. It was found that the specific activities of $^{40}$K, $^{226}$Ra, $^{232}$Th and $^{137}$Cs ranged from 292.84 $-$ 17260.59, 5.62 $-$ 812.02, 1.49 $-$ 409.53 and 2.04 $-$ 16.28 Bq/kg with mean values of 4146.73 $\pm$ 251.13, 102.54 $\pm$ 7.05, 124.46 $\pm$ 4.52 and 5.55 $\pm$ 2.41 Bq/kg, respectively. Furthermore, four radiological hazard indices which are gamma absorbed dose rate (D), radium equivalent activity (Ra$_e$$_q$), external hazard index (H$_e$$_x$), and annual effective dose rate (AED$_o$$_u$$_t$) in the investigated area were also studied and evaluated. The average values of D, Ra$_e$$_q$, H$_e$$_x$ and AED$_o$$_u$$_t$ were equal to 299.03 $\pm$ 16.58 nGy/h, 604.83 $\pm$ 33.07 Bq/kg, 1.63 $\pm$ 0.09 and 0.37 $\pm$ 0.02 mSv/y, respectively. The results were also compared with the Office of Atoms for Peace (OAP) annual report data, Thailand and global radioactivity measurement and evaluations. Moreover, the result can be used to create the radioactive contour maps of the investigated area.

Speaker: Dr Prasong Kessaratikoon (Nuclear and Material Physics Research Unit (NuMPRU), Department of Physics, Faculty of Science, Thaksin University, Muang, Songkhla, THAILAND 90000)

2:00 PM Single Beam Digital Holography using Total Internal Reflection

The technique for recording digital hologram, using single beam based on Total Internal Reflection (TIR), has been proposed. The laser diode with wavelength of 635 nm has been used as the light source. First, a positive resolution test target with a line width of 200 um has been used as the object to compare two configurations (transmission and reflection)of digital in-line holography (DIH). From experimental results, the reconstructed digital hologram of reflected DIH (RDIH) is perfect as transmitted DIH(TDIH). The equilateral triangle prism has been used to produce TIR light and fingerprint has been selected as the sample. The configuration, applied in this TIR technique, is the same as RDIH one measured from the positive resolution test target. The results show that the reconstructed digital hologram of fingerprint provides sharper patterns than the recorded digital hologram.

Speaker: Dr Suwan Plaipichit (Department of Applied Physics, King Mongkut’s Institute of Technology Ladkrabang, Bangkok 10520, Thailand)

2:00 PM SLRI Beam Test Facility Development Project

The SLRI Beam Test Facility (SLRI BTF), currently in a design phase, is a part of the future upgrades of the SLRI accelerator complex. Upon completion, SLRI BTF will be able to produce electron test beams with the number of electrons ranging from a few tens to several thousands of electrons per bunch. A simple setup in the initial stage will be implemented without any modifications to the existing high energy beam transport line (HBT), while additional elements are required for the short-term setup. For a permanent station, a newly dedicated transfer line equipped with an energy selector will be constructed to extract the electron beam from the HBT beam line. This project aims to provide a defined number of electrons in a required range of electron energy for calibration and testing of high energy detectors as well as other beam diagnostic instrumentations.

Speaker: Kritsada Kittimanapun (Synchrotron Light Research Institute (SLRI), 111 University Avenue, Muang District, Nakhon Ratchasima, 30000, Thailand)

2:00 PM Study and analysis of the new eclipsing PCEB system: SDSS J074548.63+263123.4

The common-envelope process is known as one of the complicated phases in binary evolution. A lot of efforts have been dedicated to study this common-envelope stage, but the many questions related to this process are yet to be answered. If one binary survives the common-envelope, the binary will emerge as a white dwarf accompanied by low-mass main sequence star in close orbit, or often referred as the post common-envelope binary (PCEB). SDSS J074548.63+263123.4 is one of the newly found PCEBs from the Sloan Digital Sky Survey (SDSS). In this work, we aim to confirm the eclipsing nature of J074548.63+263123.4 and to determine the stellar and orbital parameters. The primary eclipse in the light curve of SDSS J0745+2631 from our follow-up observation using the ULTRASPEC instrument from the Thai National Observatory. The data in $g^{\prime}$ filter showed an evidence of the primary eclipse. In the end of 2014, J074548.63+263123.4 was observed on several filters ($r^{\prime}$, $g^{\prime}$ and $KG5^{\prime}$ filters). Those observations shown primary eclipse and SDSS J0745+2631 is confirmed to be an eclipsing binaries system.

Speaker: Mr Niwat Hemha (School of Physics, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand)

Poster Study_and_analysis_of_the_new__eclipsing_PCEB_system_SDSS_J0745+2631.pdf

2:00 PM Study and Development of Current Transformers for Measuring of Electron Beam Pulse Current

Beam diagnostic systems and measuring devices, which are used to verify the beam properties, are essential issues of any particle beam accelerator. In this research, we focus on study and development of a current transformer for measuring a pulse current of electron beams produced from the radio-frequency (RF) electron gun and from the linear accelerator at the Plasma and Beam Physics Research Facility, Chiang Mai University. The current transformer consists of a ferrite core with high-permeability, a conductor wire wounded around the core forming a secondary coil, and a termination resistor. The electron current that runs through the transformer acts as the current in the primary coil and it induces an inductance force in the secondary winding. Therefore, the output signal from the secondary winding can be measured and analyzed to be a current value of the electron beam. The transformer is mounted over a ceramic insulator inserted in a stainless vacuum chamber to avoid an image current, which may cancel the beam current signal. This study optimizes a number of wounding turns of the secondary coil and the resistance value of the termination resistor as well as the material type of the ferrite core. Optimal parameters of the current transformer are reported and discussed in this contribution. Even though the current transformer is a nondestructive device, the output signal from the transformer may distort due to the decay characteristic of the LR circuit. This feature is, therefore, investigated to obtain the corrected factors, which will be included in the analysis of the output signal. The final results will provide more accuracy of the measuring value of the electron pulse current. This work has been supported by the CMU Junior Research Fellowship Program, and the Department of Physics and Materials Science, Faculty of Science, Chiang Mai University.

Speaker: Mr Pajongjit Naboonmee (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University 50200)

2:00 PM Study effects staging time and floor life of epoxy material to reliability performance

This research interested in studying about property of expired epoxy for extending life time of the epoxy in die attach process. Die attach process is one that is very important in the integrated circuit (IC) packaging manufacturing. A normal material used for attaching between die and substrate of a package which is an epoxy. From normal manufacturing process, an epoxy is stored in the frozen at - 40 °C and left at room temperature at 25 °C for 2 hours. The lifetime of epoxy is 24 hours, after that the large quantities of epoxy tubes shall be discarded. For experiment, the two types of expired conductive epoxy is used for die attach process of IC packages by changing the life time from 0, 6, 12, 18, 24, 30, 36, 42, and 48 hours. For analysis, these packages was tested by viscosity test, die shear test, and moisture sensitivity level test and was observed by scanning electron microscopy (SEM) to analyze properties of epoxy with a life time. The results revealed that possibility to extend the lifetime of epoxy from 24 hours to 30 hours.

Speaker: Singharach JANYOD (Department of Industrial Physics and Medical Instrumentation, Faculty of Science, King Mongkut's University of Technology North Bangkok, THAILAND 10800)

Poster Poster_Study_effects_staging_time_and_floor_life_of_epoxy_material_to_reliability_performance.pdf

2:00 PM Study of a 270-degree non-dispersive bending system.

A non-dispersive bending system is a magnetic system, which charged particles of different energies bend and move out from the system at the same point. Theoretical conditions for being a non-dispersive system are the dispersion function and its derivative vanish at the system exit. In this research, we study the non-dispersive bending system consisting of three sector dipole magnets for a total bending angle of 270 degree. Numerical calculations are performed using matrix formalism under a linear beam dynamics condition. A computer program is developed to track the electron trajectories. The study results will be used as a guideline for further design of the real bending system.

Speaker: Mr Pattadon Udomsanti (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, 50200)

2:00 PM Study of pulsation spectrum of primary, rapidly-oscillating mass-accreting component of VV UMa

We present the results of photometric study of pulsations in VV UMa Algol-type system as a part of the THASOS (Thai Southern Sky Survey for OEA Stars) survey ongoing at NARIT. The THASOS survey is focused on discoveries of a new oEA stars and detailed study their pulsation spectra and binary light curves. The hot (Te=9540K) primary component of the VV UMa, the0.687355-day Algol type system was discovered and classified as oEA star by Kim et al.2005.The dominant oscillation period of28.6min (50.3c/d) was reported. No further investigations were made in order to study the pulsation spectrum of primary component in the detail. We obtained11nights of new CCD observations of VV UMa with50cm telescope of Thai National Observatory trough V filter during 26 Dec 2013 to 23 March 2014. Data were reduced in a standard way relative the comparison stars in order to get light curve. The binary light curves were constructed and pulsational variations in the out-of-eclipse parts were investigated. The Discrete Fourier transform analysis applied to the pulsation light curves revealed multi-periodic spectrum of rapid oscillations with three dominant frequencies of29.47min (48.84c/d),30.628min (47.015159c/d) and 74.09min (19.43c/d). This is a first, detailed investigation of oscillation spectrum of VV UMa, results obtained will be used for development of further strategy of spectroscopic and photometric investigation of mass-transfer and asteroseismic analysis of this binary system.

Speaker: Ms Khemsinun Gunsriwiwat (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand)

2:00 PM Study of Undulator Radiation from Femtosecond Electron Bunches

Linac based terahertz (THz) source at the Plasma and Beam Physics (PBP) Research Facility, Chiang Mai University, consists of a thermionic RF electron gun, an alpha magnet for magnetic bunch compressor, a travelling wave s-band accelerating structure for post acceleration, and various beam diagnostic instruments. The PBP-CMU linac can produce relativistic femtosecond electron bunches, which are used to generate coherent THz radiation via transition radiation technique. To increase the radiation intensity, an electromagnetic undulator will be added in the beam transport line. The existed electromagnetic undulator at the PBP research facility have a period length of 55 mm with an undulator parameter of approximately 1 or equivalents to a peak magnetic field of around 0.2 T. Numerical calculation result shows that the brightness of the undulator radiation, which is produced from electron bunches with an energy of 10 MeV, a peak current of 300 A, and an effective bunch length of 120 fs, is 10$^{5}$ times higher than the brightness of the transition radiation. This study investigates the dependence of the electron beam energy, electron bunch charge, and electron bunch length on the undulator radiation. The numerical simulation and procedure to generate the undulator radiation in the terahertz regime by using femtosecond electron bunches produced at the PBP research facility is reported and discussed in this contribution.

Speaker: Mr Natthawut CHAISUEB (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai, THAILAND 50200)

2:00 PM Superhydrophobic Surface Modification Based on PTFE Coated AAO Template

In this research, the superhydrophobic texture based on PTFE coated AAO template surface modification. The AAO template was successfully achieved from high purity aluminium sheet by two-step anodization process in 0.3 M of oxalic acid at 40V 0 degree Celsius. The AAO template was then future widened in 5% phosphoric acid at variable period during 0 to 80 min. the effect of widening period on pore size was investigated by field-emission scanning electron microscope (FE-SEM). From FE-SEM image illustrates that the pore diameter of the template enlarges as function of widening period. Finally to achieve the extreme superhydrophobic surface, PTFE was sputtered on top of the AAO template through rf magnetron sputtering in 5 min. Regarding with the static contact angle, the superhydrophobic performance increasingly improve.

Speaker: Mr Pichet Wongsanarathib (College of Nanotechnology, King Mongkut’s Institute of Technology Ladkrabang, Bangkok, Thailand 10520)

2:00 PM Surface modification of polysulfone by plasma techniquce

This project studied on the asymmetric polysulfone (PSF) membranes surfaces were modified by DC plasma at low pressure using argon as working gas in this project. The main objective of this project is to increase the hydrophilic property of the polysulfone (PSF) membrane surface. Samples of asymmetric PSF membrane were modified by DC plasma at low pressure using argon (Ar) as working gas. Plasma process conditions such as treatment time and discharge power were varied. PSF membranes both before and after plasma treatment were characterized by using several analytical techniques. The alteration of hydrophilic property was analyzed through the measurement of contact angle and surface free energy calculation. The surface morphology and structure of PSF membrane was evaluated by scanning electron microscope (SEM), while the creation of functional group and the change of mechanical strength were studied by Fourier Transform Infrared Spectroscopy (FTIR) and dynamical mechanical thermal analysis (DMTA). Results showed that the hydrophilicity of PSF membrane surface clearly increased after plasma treatment. In addition to the hydrophilic property, the mechanical properties of PSF membrane surfaces in term of storage modulus were changed and some of functional group may introduce to the plasma treated PSF membranes.

Speaker: Ms Maytipa Phalakarn (Prience Of Songkla University)

2:00 PM Synthesis and characterization from Zn1-xCoxFe2O4 nanostructures prepared by hydrothermal method

In this work, we report the synthesis of Zn${}_x$Co${}_{1-x}$Fe${}_2$O${}_4$ nanoparticles ($x$ = 0.0, 0.2, 0.4, 0.6, 0.8, and 1.0) prepared by hydrothermal method. The results of XRD, SEM and TEM showed that were cubic spinel structure with the particle size in the range of 7-17 nm. The IR spectra of Zn${}_{1-x}$Co${}_x$Fe${}_2$O${}_4$ nanoparticles exposed the intrinsic stretching vibrational modes of the metals at the tetrahedral and octahedral sites. The magnetic properties as measured by VSM indicated that all sample behaved ferromagnetic with saturation magnetization (Ms) and coercivity of 15-52 emu/g and 72-257 Oe, respectively. The XANES spectra were used to identify the oxidation state of Zn, Co and Fe ions using K-edge profiles by shifts of separate edge. The oxidation state of Zn and Co cations are found to be +2 and +2,+3 respectively. The Fe${}^{2+}$ and Fe${}^{3+}$ cations are preferable to be at preference for the tetrahedaral and octahedral sites, respectively.

Speaker: Mr narinthorn Wiriya (Department of Material Science and Nanotechnology, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand)

2:00 PM Synthesis and Characterization of amorphous carbon film for potential application in cell culture

Plasma enhanced chemical vapor deposition (PECVD) is one of the method of coating thin film for improve surface material properties which can be apply to electronic, medicine and bio molecular. This research focuses on coating amorphous carbon thin film by PECVD technique for cell culture applications. PECVD is the process operated at low temperature, able to control compound and properties of film as well, with high deposition rate and good adhesion with substrate. We synthesized amorphous carbon film from plasma of gas mixture between acetylene and ammonia at gas various and characterized amorphous carbon film by context angle, Atomic Force Microscope(AFM),Fourier Transform Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectroscopy (XPS) and Scanning Electron Microscope (SEM). Mixed gas plasma parameters has been carried out by a rf-compensated Langmuir probe. The operating RF power vary from 20 to 80 W and gas pressure from 100 to 300 mTorr, respectively. The result showed electron temperature increased when RF power increased but it decreases when gas pressure increased.

Speaker: Ms Watcharaporn Intatue (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University 239 Huaykaew Road, Tumbol Suthep Amphur Muang, Chiang Mai 50200 THAILAND)

Poster Synthesis_and_Characterization_of_Amorphous_Carbon_Film_for_Potential_Application_in_Cell_Culture.pdf

2:00 PM The properties of Traversable Wormholes

General relativity theory is a gravitational theory describing relation between spacetime geometry and mass/energy. General relativity provides mysterious prediction of spacetime geometry such as black holes and wormholes. Black hole is a spacetime geometry surrounding a massive object in which there exists a characteristic radius that even light cannot be escaped from the object. Wormhole is a spacetime region which connects between two asymptotically flat spacetimes. In fact, the wormholes can exist in the black hole solution, even in the simplest solution called Schwarzschild solution. However, it is not possible to travel through this region by human. Recent investigation shows that it is possible to construct the theoretical model of wormhole in which human can travel through namely “Traversable Wormhole”. The objective of this project is to investigate geometries and properties of the traversable wormhole. First, we study basic properties of a simple wormhole in Schwarzschild and Reissnor-Nordstrom geometries. It was found that the traversable wormhole must satisfy three conditions as follows: the horizon is absent in the wormhole, travelling time in the wormhole travel is about 1 year, and gravity in the wormhole is comparable to gravity on the Earth. To create such the wormhole, one may need an exotic matter and the properties of this matter are left to investigate for further work.

Speaker: Mr Nopadhol Kamma (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand)

2:00 PM The Use of SMD-473 as a Potential X-ray Accidental Dosimeter through the Thermoluminescene Properties

In study of emergency dosimeters to be used in case of accidental radiation exposure of the population, retrospective dosimetry is one of the most important for dose measurement in contaminated areas. In this paper discusses the thermoluminescence (TL) properties of alumina porcelain substrates of thin film chip resistors removed from computer circuit boards. X-ray photon energy 160 keV was used to irradiate samples in the dose range of 10 to 80 mGy.The results of this work demonstrate that Surface Mount Devices (SMD resistors) can be used as low dose accidental dosimetry, the dose response of the chip resistor is linear from 10 to 80 mGy, proper glow curve peaks, the fading of TL signal remained about 60% even after one month at room temperature and the minimum detectable dose is very low estimated 0.2 mGy.

Speakers: Mrs Jintana Laopaiboon (Department of Physics, Faculty of Science, Ubon Ratchatani University, Ubon Ratchatani, THAILAND 34190), Mr Raewat Laopaiboon (Department of Physics, Faculty of Science, Ubon Ratchatani University, Ubon Ratchatani, THAILAND 34190)

2:00 PM Theoretical investigation on the geometrical symmetry and electronic behavior of the three lower members of diamondoids by using first-principles calculations

First-principles calculations have been investigated on the geometrical and electronic properties of the three lower diamondoid structures including adamantane (C${}_{10}$H${}_{16}$), diamantane (C${}_{14}$H${}_{20}$) and triamantane (C${}_{18}$H${}_{24}$) molecules. The energy gap obtained from the difference between the highest occupied (HOMO) and lowest occupied (LUMO) molecular orbital for all three structures decreased with the size of diamondoids increasing. The C${}_{10}$H${}_{16}$ molecule is the most wide band gap (7.22 eV) and that of C${}_{14}$H${}_{20}$ and C${}_{18}$H${}_{24}$ are 6.84 eV and 6.59 eV, respectively. The geometry calculations indicated that the geometrical symmetry of three molecular structures appears to be the Td (tetrahedral), D3d (Dihedral) and C2v (Cyclic) point groups for C${}_{10}$H${}_{16}$, C${}_{14}$H${}_{20}$ and C${}_{18}$H${}_{24}$, respectively, which implies the high-symmetry structure for the three lower diamondoids.

Speaker: Mr Nikorn Shinsuphan (Materials Science and Nanotechnology program, Faculty of Science, Khon Kaen university, Khon Kaen 40002, Thailand)

2:00 PM TNT Photometric Reverberation Mapping campaign of High-z Quasars

Motivated by the upcoming photometric surveys that will cover a broad range of wavelengths and regularly monitor a fair fraction of the sky with good photometric accuracy (e.g. the Large Synoptic Survey Telescope, LSST), we aim to provide proof-of-concept that photometric reverberation mapping of the Broad Line Region (BLR) in quasars is feasible at high-z and fainter magnitudes than that already shown by previous study. This technique is very important if we were to determine the masses of Super Massive Black Holes (SMBH) powering the high-z quasars where the traditional spectroscopic Reverberation Mapping (RM) method would fail. Here, we will describe our high-z quasar photometric reverberation mapping campaign (PI: U. Sawangwit) being carried out with the 2.4-meters Thai National Telescope (TNT) at Doi Inthanon. Our selection criteria have been designed to ensure the quasar BLR sizes and hence their lag time is well covered by the observing season of the TNT. This results in a sample of 30 spectrally confirmed quasars, selected from SDSS-III BOSS survey to be further studied with the Photometric RM during the 2014-2015 observing season. Due to the magnitude limited nature of the spectroscopic survey, the z > 1.5 quasars are intrinsically very luminous and therefore have very long lag time (and large BLR size), to ensure our survey remain complete we hence limit our quasar sample to z < 1.5, g ≤ 21.5mag and the inferred BLR size from R-L relation to 60 light-day.

Speaker: Ms Grittiya Pongsupa (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand)

2:00 PM Trajectory Simulation of Ion Beam from Duoplasmatron Ion Source

This project aims to study about structure and function of Duoplasmatron ion source in Tandem accelerator. We used program SIMION to simulate ion beam from Duoplasmatron ion source. If we use SIMION, we can get appropriate parameters that show the best ion beam. The best ion beam is the beam that has little spread and looks parallel. After simulation the ion beam with SIMION, result show that the best ion beam occurred when an anode 0 volt, extractor -10 kilovolts, einzel lens, respectively. The experimental set up comprise of three conditions as following: are Einzel lens comprise of section 1 and 3 set as 0 volt and einzel lens section 2 which is the middle section set as -10 kilovolts. Result showed that the ion beam from experiment are close to parallel and have a little spread, like result from simulation. So, the simulation from SIMION can help us to save time, materials and money to pay from repeated the experiment several times.

Speaker: Ms Suratsa Meebua (Department of Physics, Faculty of Science, Prince of Songkla University, Songkhla, THAILAND 90110)

2:00 PM Zn(O,S) Thin Films Deposited by Pulse–DC Magnetron Sputtering for an Alternative Cd-Free Buffer Layer

Zn(O,S) thin films were deposited on glass substrates using pulse DC magnetron sputtering for 60 minutes. The sputtering power was varied from 70 to 100 W with oxygen reactive gas from 0 to 5 sccm at a constant pulse frequency of 200 kHz at room temperature. The optical properties of Zn (O,S) thin films was characterized by using UV-Visible spectroscopy, the thickness and composition of films were analyzed by Dektak profile and electron probe microanalysis (EPMA). The morphology of films were characterized using atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM). The transmittance of all specimens were higher than 80% in the wavelength between 300 nm to 900 nm. Optical band gap of Zn (O,S) thin films varied between 3.5 eV to 4.1 eV. The RMS roughness decreases from about 40 nm to about 15 nm when the sputtering power increase from 70 W to 100 W. The composition of Zn (O,S) thin film showed the increase of oxygen content when increasing oxygen reactive gas. The increase of oxygen content increased transmittance of the specimens. Also, the samples with low sputtering power condition contained higher atomic percentage of oxygen than those with high sputtering power. The composition of Zn(O,S) thin film for alternative Cd-free buffer layer can be varied using this proposed method.

Speaker: Mr Ekkaphop KETSOMBUN (Department of Physics, Faculty of Science, King Mongkut’s University of Technology Thonburi, Bangkok, Thailand, 10140)

2:00 PM → 5:30 PM Physics Education (APRU)

2:00 PM The silent killer of learning

Why is it that stellar students sometimes fail in the workplace while dropouts succeed? One reason is that most, if not all, of our current assessment practices are inauthentic. Just as the lecture focuses on the delivery of information to students, so does assessment often focus on having students regurgitate that same information back to the instructor. Consequently, assessment fails to focus on the skills that are relevant in life in the 21st century. Assessment has been called the "hidden curriculum" as it is an important driver of students' study habits. Unless we rethink our approach to assessment, it will be very difficult to produce a meaningful change in education.

Speaker: Prof. Eric Mazur (Harvard University)

2:30 PM A Possible Route to Reverse Declining Trend in Student Performance at First-year University Physics Course

A high failure rate is becoming a common occurrence in university physics courses for the first year students. Will there ever be a way out? Here we report a case study of a first-year physics course (with a class size of fifty) at College of Nanotechnology, KMITL. The course has been designed to bridge the gap between basic physics at high schools to advanced physics concepts in materials science and nanotechnology. “Physics concepts before maths” has been adopted as the central philosophy, in correspondence with Alan van Heuvelen’s US case study and UK GCSE physics. A question on “What is Physics?” has been used an example to realign the students to the learning method to focus on skills and concepts, rather memorizing details and formulae. Multiple measures have been implanted concurrently, rather than an emphasis on one aspect, including small group teaching, practical demonstration, inquiry methods, regular assignments, customized course design, active learning, pre-mid-term practice test, and a coherent class schedule in the mathematics course. The pre- and post-test results, with a written exam format (no multiple choice), show a significant improvement in the class average from below 30% to above 60%. The same results have been obtained for three consecutive years. One possible key aspect on the course management that may lead to this improvement is that only a small number of “concepts and skills to take home” are emphasized in each three-hour weekly lesson.

Speaker: Dr Sirapat Pratontep (College of Nanotechnology, King Mongut’s Institute of Technology Ladkrabang, Chalongkrung Rd., Ladkrabang, 10520, Thailand)

2:45 PM Team Teaching in First-Year Physics Class

Team teaching is a strategy that has been used in first-year physics classes at Mahidol University for ten years. This specific method consists of two teachers working together in the same classroom. The courses were Introductory Physics I and II for first-year science students (ranging from 250 to 300 students) and the lectures were conducted in a large sloping theatre. Worksheets have been used as the main teaching tool which helps promote interactive lectures. Each teacher has their own roles; one being in front of the class conducting students to go through contents and write down on worksheets while the other moving around the theatre to elaborate on the content as well as prompting and answering questions from small groups of students as they solve problems. These roles may be switched occasionally. The study of the effectiveness of the method will be presented. The evidence was gathered from class observation, student learning and student satisfaction which were surveyed from course evaluation and interviews. The results show that each teacher provides a unique strength to the teaching team and the continuous engagement of students.

Speakers: Kwan Arayathanitkul (Department of Physics, Faculty of Science, Mahidol University, Bangkok, THAILAND 10400), Narumon Emarat (Department of Physics, Faculty of Science, Mahidol University, Bangkok, THAILAND 10400)

3:00 PM Students’ physics laboratory skill in measurement and uncertainty

This study investigates students’ skill in physics laboratory; in particular, measurement and uncertainty. Data were obtained from undergraduate physics students from various universities in Thailand, including the second-year physics students at Mahidol University. It was found from pre-test that most students, who have already passed the introductory physics laboratory class, still lack of these two basic skills. In academic year 2014, the second-year physics students at Mahidol University were trained about basic laboratory skills in the first day of laboratory class and once again after they had been learning for half of the semester. Student performance during laboratory class was observed and the students’ laboratory reports were also collected. In the second semester, a worksheet was constructed and applied in a second-year physics laboratory class at Mahidol University. The worksheet containing four laboratory questions was created for helping students’ learning in the possible sources of uncertainty in a measurement. The post-test responses of students will be analyzed to assess students’ achievement. The effectiveness of the worksheet will be compared with traditional instruction. It is expected that the worksheet could help improve students’ skill in measurement and uncertainty.

Speaker: Mr Ariyaphol Jiwalak (Department of Physics, Faculty of Science, Mahidol University, Bangkok, THAILAND 10400)

3:15 PM Measurement of Triboelectric Charges by Using Faraday's Cage and Darlington Transistor Circuit

When two objects made from different materials are rubbed and immediately separated, negative charges or electrons are then transferred from a surface of one object to another one, depending on material of each object. The charge transfer process due to rubbing is called “triboelectrification.” This study aimed to measure transferred triboelectric charges by using two methods. The first method is to measure the triboelectric charges using Faraday’s cage and Vernier charge sensor. The second method is to use the Darlington transistor circuit consisting of two transistors to amplify current induced by electric field of triboelectric charges. The measured values of triboelectric charges from both methods are compared.

Speaker: Ms Chitchanok Lesak (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai, 50200, Thailand; Physics Education Research Laboratory, Faculty of Science, Chiang Mai University, Chiang Mai, 50200, Thailand)

3:30 PM A Robust and Scalable Framework for Question-Answering in Physics

Over the past two decades, research has shown that students who experience academic difficulties and actively seek help achieve academic success. This finding has resulted in the development of various adaptive help seeking components for adaptive learning environments. However, the existing question-answering systems are designed based on specific templates. Thus, it is not robust enough to cover other learning topics, often providing unrelated answers to questions outside the defined template. In this paper, we tackle this issue by proposing a more scalable architecture which is not restricted by a rigid template. Our proposed framework consists of various modules developed using several artificial intelligence and NLP techniques including semantic network, domain classification, entity recognition, inference engines and reusable ontologies. Using classification and entity recognition techniques, relationships between topics, principles, concepts and equations are automatically represented in a semantic network. This provides knowledge about the superclass-subclass relationships within the domain. Ontology is used to represent the description and properties of each concept in the semantic network. The main purpose of representing this knowledge is to support a system in reasoning about provided information and making inferences. Our proposed framework is envisioned to provide assistance to students, while solving problems.

Speaker: Bimba Andrew (Faculty of Computer Science and Information Technology, University of Malaya, 50603 Kuala Lumpur)

3:45 PM Physics students’ understanding and problem-solving process of Gauss’s law

Gauss’s law is important in understanding electrostatic; however, it is one of topics that students have difficulties in understanding and solving problems. This study aimed to analyze students’ understanding of electrostatics while solving Gauss’s law problems. In surveying student understanding of Gauss’s law, a conceptual survey on symmetry and Gauss’s law developed by Singh (2000) were administered to 100 sophomores taking an electric and magnetism course in 2014 academic year. As a result, most students had difficulties with Gauss’s law. Then, 16 students were voluntarily participated in an interview for collecting qualitative data on students’ understanding and problem solving process in Gauss’s law. From the interview results, students had difficulties in identifying enclosed charge in both conductors and insulators. Results have been used to develop a tutorial for help student construct correct understanding in this topic.

Speaker: Mr Panat Nanthanasit (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai, 50200, Thailand)

Slides

• Gauss's_Law_(Tutorial).pdf
• SPC2015-Panat-edited-May-18.pdf
• SPC2015-Panat-edited-May-18.pptx

4:00 PM The Use of Interactive Lecture Demonstration to Teach High-School Physics in Magnetic Force on a Moving Charged Particle

We have adopted the Interactive Lecture Demonstration (ILD) which is one of the active learning strategies to teach high-school students in the topic of magnetic force on a moving charged particle in order to enhance student conceptual understanding. Three sample groups of grade 12 students were studied; G1 and G2 were taught by ILD but students in G1 had a better background of physics knowledge than G2. The other group is G3 which was taught by traditional teaching and their background of physics knowledge was similar to G1.The demonstration set used in the ILD included a cathode-ray tube and a magnet which were common physics apparatus available in most high schools. After instructions, all students were evaluated their conceptual understanding by using a post-test which is related to this physics topic. The post-test scores of all groups were significantly different with G1 showing the highest score and G3 showing the lowest score. Although the background knowledge of students in G2 was lower than that of G3, the higher post-test score of G2 infers that students who studied by ILD had more conceptual understanding than those who studied in the traditional classroom.

Speaker: Mr Nuttawoot Sricharoenchai (Department of Physics, Faculty of Science, Mahidol University, Bangkok, THAILAND 10400)

4:15 PM Using Modules to Teach Conservation of Momentum to High-School Students

The objective of this study was to improve student’s understanding and problem solving skill for high-school students in the topic of conservation of momentum in the collision. The topic covered concepts of momentum and impulse, type of collision, law of conservation of momentum and collision in one and two dimensions. We used the learning modules that were composed of the guided worksheet , demonstration for each type of collision and the strategies for problems solving. The modules were used to teach grade-10 students at a school in Bangkok in 2014. Two classes were taught by using the modules. The other two classes were taught by traditional teaching. After finishing the topic of momentum, all students were asked to do a test in the topic of conservation of momentum in the collision. The test consisted of 4 questions. Question 1 asked about the direction and speed of collision in one dimension. Question 2 asked students to determine whether a given situation is elastic or inelastic. Question 3 asked about the equations needed to solve a one dimensional elastic collision. The last question asked about a simple collision in two dimension. The preliminary results showed that students in both classes teaching with these new modules had significantly better understanding than the traditionary classes.

Speaker: Mr Trai Unyapoti (Department of Physics, Faculty of Science, Mahidol University, Bangkok, THAILAND 10400)

4:30 PM Teaching Problem-Solving Strategy in Circular Motion to First-Year Science Students

Many students have difficulties when they solve problems in circular motion. This motivated us to create a problem-solving strategy for such particular topic. The strategy was incorporated in the large-class instruction by including it in a class-worksheet. We expected that the strategy could help students work their way through solving circular motion problems. The sample was composed of first-year science students who enrolled in an Introductory Physics course. They were assigned pre-test and post-test on a problem in circular motion. The effectiveness of the strategy was evaluated from the student answers. It was found that after instruction most of the students could solve the problem by following the steps shown in the strategy. In the presentation, we will show how the students solve the problem in the tests before and after they learned the strategy offered in the class-worksheet. In addition, the models of student understanding in circular motion will also be presented.

Speaker: Ms Arunee Eambaipreuk (Department of Physics, Faculty of Science, Mahidol University, Bangkok, THAILAND 10400)

4:45 PM Enhancing Students’ Understanding in Simple Harmonic Motion by Using Video Analysis

Simple harmonic motion is physics’ topic that the student still has misconception and difficulty. Predict-observe-explain approach is based on constructivism. It is designed for engaging the student to the learning situation while the video analysis technique supports students to link a real world and theoretical analysis. Therefore, this study aimed to enhance students’ understanding of simple harmonic motion concepts, including velocity, acceleration and restoring force, by using predict-observe-explain approach integrated with video analysis technique. The participants were 37 grade 10 students in science class at Satrichaiyaphum school, Chaiyaphum province in the second semester of 2014 academic year (November 2014 - March 2015). The research tools were worksheets and lesson plans based on predict-observe-explain approach, Tracker program, and simple harmonic motion conceptual test. Students’ did experiments and observed by using mobile’s camera recorded the motion of mass attached spring and simple pendulum. Then the recorded video was analyzed through Tracker program. The two-tier simple harmonic motion conceptual test as a pre-test and post-test used to determine students’ understanding into five types including complete understanding, partial understanding, partial understanding with specific alternative conception, alternative conception and no understanding. The results showed that students’ understanding was developed in all simple harmonic motion concepts.

Speaker: Ms Jiraporn Boonpo (Department of Education in Science and Technology, Faculty of Education, Khon Kaen University, Thailand, 40002)

Slides SPC_Jiraporn_complete.pdf SPC_Jiraporn_complete.pptx

5:00 PM Investigating ideas of Phayao high school students about Kepler’s law motions and Classical Mechanics

This research aims to survey the ideas of 120 high-school students, in Phayao province, about Kepler’s laws of motion and classical mechanics. Both topics, all students already studied in Astronomy and Physics classes. Their ideas are investigated by the open-ended questions which allow them to answer and give their reasons to support. Students’ responses are categorized by determining how they apply classical mechanics principles to explain Kepler’s laws of motion. The results reveal that about 50% of all students can describe the Kepler’s laws of motion by determining an angular speed and gravity. Surprisingly, most of them did not give any reasons about conservation of angular momentum, conservation of energy and action-reaction law (Newton’s third law) in solar system. Some critical data are also collected by interviewing the teachers who teach Astronomy and Physics in the surveyed schools.

Speaker: Dr Watcharawuth Krittinatham (1Division of Physics, School of Science, University of Phayao, Phayao, THAILAND 56000)

Slides SPC2015_SlideID249_Watcharawuth.pptx

5:15 PM A surveying of high school students’ understanding of buoyant force

The understanding students’ conceptual background after the traditional teaching for studying static fluid is one of the most essential keys to design effective teaching activities. The conceptual understanding of 245 high school students in the topic of buoyant force act on the object in liquid was investigated by using 10 questions conceptual understanding test. The questions were divided into 2 groups. The questions asked to compare the buoyant force act on the objects which has different mass, volume and density in the same liquid (6 questions) and different liquid (4 questions) were observed. The results of the survey are reported in this study. Furthermore, conceptual misunderstanding held by students is also discussed.

Speaker: Mr Chatchai Hussadorn (Department of Physics, Faculty of science, King Mongkut’s University of technology Thonburi, 126 Prachautid road, Bangmod, Bangkok 10140 Thailand)

Paper FullpaperSPC2015_HUSSADORN complete.docx FullpaperSPC2015_HUSSADORN complete.pdf

Slides A_surveying_of_high_school_students’_understanding.pdf A_surveying_of_high_school_students’_understanding.pptx

2:00 PM → 3:30 PM Condensed Matter Physics

2:00 PM Cathodoluminescence study of electric-field induced migration of defects in single crystal ZnO

Point defects in ZnO play importance roles in chemical, optical and electrical properties of the material. Capability of manipulating the defects could lead to material engineering and benefit the field of ZnO based sensor, catalyst and optoelectronics. Here we examined redistribution of charge point defects in hydrothermally grown ZnO single crystal under the influence of external electric field at elevated temperature. Direct current (DC) electric field was applied to the device sandwiched between two parallel plate shaped electrodes with dielectric spacers. Near band edge (NBE) and deep level transitions in ZnO samples were measured using a scanning electron microscope equipped with a cathodoluminescence spectrometer. Green emission band with peak position of about 2.4 eV and yellow emission band with peak position of about 2.0 eV were observed. The most intense green emission was found on the surface of the ZnO sample closed to a negative electrode, whilst that of yellow emission were comparable among all samples. Difference in emission spectrum could contribute to varying density of charge-associated luminescent centres along the direction of electric field. Substitution of lithium, LiZn, has been known to be a neutral acceptor responsible for yellow luminescence in a hydrothermal grown ZnO which could not be influenced by the external field. Suppression of green emission after hydrogen plasma treatment suggests that the responsible luminescence centres could be a donor acceptor pair transition of zinc vacancy, VZn2-, anion and a shallow donor. Analysis of near band edge emission which provide information on types of shallow donor presented in the device will be discussed.

Speaker: Jedsada Manyam (NANOTEC, National Science and Technology Development Agency, Pathumthani, THAILAND 12120)

2:15 PM Revealing an unusual transparent phase of superhard iron tetraboride under high pressure

First principles–based electronic structure calculations of superhard iron tetraboride (FeB$_4$) under high pressure have been undertaken in this study. Starting with a “conventional” superconducting phase of this material under high pressure leads to an unexpected phase transition toward a semiconducting one. This transition occurred at 53.7 GPa, and this pressure acts as a demarcation between two distinct crystal symmetries, metallic orthorhombic and semiconducting tetragonal phases, with Pnnm and I4$_1$/acd space groups, respectively. In this work, the electron–phonon coupling-derived superconducting Tc has been determined up to 60 GPa and along with optical band gap variation with increasing pressure up to 300 GPa. The dynamic stability has been confirmed by phonon dispersion calculations throughout this study.

Speaker: Mr Komsilp Kotmool (Department of Physics, Mahidol Wittayanusorn School, Nakhon Pathom, Thailand 73170; Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok, Thailand 10330)

2:30 PM $Ab$ $initio$ calculations of structural phase transitions of XP compounds (X=La, Ce, Pr, and Nd) under high pressure

Lanthanide-monophosphate materials have been used in many applications, such as scintillators for detecting radiation and inorganic fluorescent labels. In this work, high-pressure phase transitions of XP (X = La, Ce, Pr, and Nd) have been undertaken. Based on density functional theory (DFT), the energetic stability of XP materials were investigated to verify the most stable structures at pressure ranges. NaCl-type, CsCl-type, PbO-type, and P4/mmm which are based on related experimental results, were chosen to carry out in all XP materials. Using local density approximation (LDA), the results reveal that all compounds exhibit the NaCl-type structure at ambient pressure which is in good agreement with the experiments. LaP, CeP and NdP transform by the path of NaCl-type → PbO-type → CsCl-type structure. Moreover, CeP continuously undergoes the transformation to P4/mmm structure. In contrast, PrP passes P4/mmm phase before approaching PbO-type structure. Electronic density of states (DOS) and band structures were performed to clarify the phenomenon of high-pressure phase transitions of these compounds.

Speaker: Mr Chirayu Sainamthip (Mahidol Wittayanusorn School, Nakhon Pathom 73170, Thailand)

2:45 PM Hydrogen adsorption of Ti decorations in Mg-Metal Organic Framework-74: A First-Principles Study

Metal-Organic Frameworks show to be one of the most promising materials for hydrogen storage materials owing to containing lots of hydrogen trapping sites, tunable pore size and cheap to produce. However, the hydrogen adsorption energy of these materials is very low. In the present work, we functionalized Ti on the surface of Mg-Metal Organic Framework-74 (Mg-MOF-74) in order to enhance the hydrogen binding energy. For Ti adsorption sites on the Mg-MOF74, seven adsorption sites were considered, and we found that Ti binding energy ranges from 0.5-2.9 eV. Moreover, we put 1-3 H2 on the most stable Ti decorated site of Mg-MOF-74. Our results revealed that the hydrogen adsorption energies range from 0.51 to 2.43 eV/H2. Lastly, the hydrogen uptake of Ti-functionalized Mg-MOF-74 was evaluated by means of Ab initio Molecular Dynamics simulations. We found that the hydrogen capacities of this structure are 1.81, 1.79, and 1.29 wt% at 77, 150, and 298 K, respectively.

Speaker: Ms Pitphichaya SUKSAENGRAT (Department of Physics, Faculty of science, Khon Kaen University, Khon Kaen, THAILAND 40002)

3:00 PM Computational study of carbon dioxide adsorption on single-walled carbon nanotubes.

This project deals with the calculation of adsorption energies of carbon dioxide adsorbed on single-walled carbon nanotube with three different radii, namely 1.35, 2.71 and 4.07 Å by using the Density Functional Theory. Our results revealed that carbon dioxide molecule prefers to bind on single-walled carbon nanotubes with the molecular axis parallel to carbon nanotubes surface. Moreover, the adsorption energy of carbon dioxide is inversely proportional to radius of the carbon nanotube. We also found that the distance between center of mass of carbon dioxide molecule and carbon nanotube does not affect to the adsorption energy of carbon dioxide molecule. For charge analysis of carbon dioxide molecule, we found that carbon atom loses two electrons to each oxygen. Consequently, the charge states of carbon and oxygen atoms are +4e and -2e, respectively. Based on the O-C-O angle measurements, we found that the distortion of the carbon dioxide molecule is increased when the radius of carbon nanotube is decreased. This leads to the fact that the reduction of carbon dioxide adsorption energies when the radius of the carbon nanotube is gained comes mainly from the distortion of the carbon dioxide molecule.

Speaker: Ms Kamonrat Kasornmala (Materials Science and Nanotechnology Program, Faculty of science, Khon Kaen University, 40002 Khon Kaen, Thailand)

3:15 PM Stability Diagrams of Single-Electron Transistors

Stability diagrams are a powerful tool for both analysis and design of single electron devices. These diagrams generally show stable regions and also state-transition lines. This tool has become useful for the investigation on the tunneling process within the devices. In this work, the procedure to build a stability diagram of the single electron transistor has therefore presented. The fundamental concept of the electrostatic potential was employed in the mathematical modelling of the electron-tunneling process between the electrode and the quantum dot (island). With a single isolated metal island in the architecture,four linear equations were modeled based on the possible tunneling events in the single-electron transistor. By changing the number of the excess electrons in the island, the stability diagram of the single-electron transistor was plotted to display the transition borders between regions. This technique can be extensively applied to the study of other single-electron devices, such as single-electron pumps.

Speaker: Mr Titipong Phoopathong (Theoretical Condensed Matter Physics Research Unit, Department of Physics, Faculty of Science, Mahasarakham University, THAILAND 44150)

2:00 PM → 3:45 PM Material Physics, Nanoscale Physics and Nanotechnology

2:00 PM Characterizing Electrical Properties of ZnO Nanowires with Scanning Probe Microscopy

ZnO nanowires have been widely studied due to their unique direct wide band gap of 3.37 eV making it attractive for electronics, optical detectors and light-emitting diodes application. In this work, we focus on ZnO nanowire-metal junction. N-type ZnO nanowires were growth vertically on a silver substrate (of ratio1:1of HTMA:Zinc nitrate) by hydrothermal process at the varied concentration. Characterization ZnO nanowires was conducted using conductive atomic force microscopy allowing measurement of I-V characteristic from an individual nanowire. The I-V characteristic reveals a resistive switching behavior, which is sensitive to acquisition time. Understanding the I-V characteristic could shade light on the origin of resistive switching behavior in ZnO nanowires and the nature of ZnO-silver junction. This type of understanding is crucial information for applications.

Speaker: Mr Komsun Rapaway (School of Physics, Institute of Science, Suranaree University of Technology, Nakorn Ratchasima, THAILAND 30000)

2:15 PM *In situ* XANES Study of MnO${}_2$ Electrode for Supercapacitors

Manganese dioxide (MnO${}_2$) is one of the most studied electrode materials for use in supercapacitors due to its distinguished properties such as high specific capacitance, environmental compatibility, and low cost. In this study, local and electronic structures of Mn in MnO${}_2$ electrode have been investigated by in situ X-ray absorption spectroscopy technique. *In situ* Mn *K*-edge XANES spectra measured during constant voltage charge-discharge processes within the potential window of 0-1 V were recorded. The results (Fig. 1) show some little changing of the oxidation state of Mn because of redox reaction on only the surface of electrode. This result indicates that within this potential window, ideal capacitive behavior or surface redox reaction occurs, and the intercalation does not occur. ![Fig.1 Mn K-edge XANES spectra][1] [1]: https://drive.google.com/file/d/0Bx8ij8NCt4nBVzRvV014NXFNeUE/preview

Speaker: Ms Piramon Hampitak (Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen, THAILAND 40002)

2:30 PM Mie Scattering by Small Sphere Particles

The objective of the research was to study how the size of the spherical particles and the wavelength of the incident electromagnetic waves affect the intensity of the scattered electromagnetic waves. We began the calculation by solving the Helmholtz equation to obtain the scalar wave equation which led to the scattered wave by the spheres. In the limit of far-field region, the radial component of the scattered wave may be neglected and the intensity of the wave can be represented in terms of a dielectric constant of a medium, the incident light wavelength and angles. Then the future work will be comparing the theoretical results with the experimental data of light scattering in silver nanoparticles.

Speaker: Irada Theppabut (Department of Physics, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok, THAILAND 10140)

Slides SPC-1.pdf SPC-1.pptx

2:45 PM Giant Dielectric Permittivity and Low Dielectric Loss Tangent in Yb-doped CaCu${}_3$Ti${}_4$O${}_{12}$ Ceramics

In this research work, the giant dielectric response in Ca${}_{1-3x/2}$Yb${}_x$Cu${}_3$Ti${}_4$O${}_{12}$ ($x$ = 0, 0.05, 0.15) ceramics prepared by a modified sol-gel method and sintered at 1100 ${}^{\circ}$C for 6 and 12 h were investigated as functions of temperature and frequency. A single phase of CaCu${}_3$Ti${}_4$O${}_{12}$ was obtained in all ceramic samples. Grain growth of Ca${}_{1-3x/2}$Yb${}_x$Cu${}_3$Ti${}_4$O${}_{12}$ ceramics was effectively inhibited by Yb${}^{3+}$ doping ions, which can be explained to the effect of solute drag of Yb${}^{3+}$ doping ions. High dielectric permittivity ($\sim$10${}^4$) and very low loss tangent ($\sim$0.01$-$0.02) at 1 kHz with good temperature stability of ${\varepsilon}^{\prime}$ ranging from -55 to 125 ${}^{\circ}$C were achieved in a Ca${}_{0.925}$Yb${}_{0.05}$Cu${}_3$Ti${}_4$O${}_{12}$ ceramic. Furthermore, the dielectric permittivity was found to be nearly independent of frequency (10${}^2 -$10${}^6$ Hz) and dc bias voltage (0$-$40 V). Interestingly, the grain boundary resistances of Ca${}_{1-3x/2}$Yb${}_x$Cu${}_3$Ti${}_4$O${}_{12}$ ceramics at room temperature were calculated from the activation energies and found to be $\sim$0.7$-$12.5 G$\Omega$.cm. The effect of annealing in O${}_2$ atmosphere on the dielectric properties was also investigated. It was suggested that variations in dielectric properties of Ca${}_{1-3x/2}$Yb${}_x$Cu${}_3$Ti${}_4$O${}_{12}$ ceramics due to Yb${}^{3+}$ substitution and annealing were associated with the electrical response at grain boundaries.

Speaker: Mr Jakkree Boonlakhorn (Materials Science and Nanotechnology Program, Faculty of Science, Khon Kaen University, Khon Kaen, THAILAND 40002)

3:00 PM Improvement of Graphene-Metal Contacts by Current-Induced Cleaning

The issue of contact resistance between graphene and metal contacts is crucial in the development of high-speed graphene devices. However, fabrication-related contamination severely affects the contact resistance in graphene and hence an effective post-fabrication method is needed to resolve this problem. Current-induced cleaning has previously been used successfully to clean the surface of graphene using the concepts of Joule heating. However, its effect on the graphene-metal contact resistance has not been well documented. By studying as many as 20 devices with varying sample sizes and geometry, we demonstrate that current-induced annealing may be used as an effective in-situ annealing procedure to improve the graphene-metal contact resistance which has long been an issue in characterizing graphene-based devices. With this technique, we are able to reduce the overall resistance systematically to around 1000 Ω μm, which is competitive with the best values obtained in the literature to treat this problem. We also demonstrate the effectiveness of current annealing in desorbing contaminants from the surface of the graphene layer, simultaneously shifting the charge-neutrality point to zero back-gate voltage, thus allowing the tuning of carrier density on both the electron and hole sides of the Dirac spectrum. Finally, we highlight certain high-bias effects such as electro-migration that may prove to be detrimental to the operation of these devices.

Speaker: Dr Ratchanok Somphonsane (King Mongkut' s Institute of technology Ladkrabang)

3:15 PM Phase Formation and Microstructure of Sodium Niobate Powder Synthesized Using Molten-salt Technique

Sodium niobate (NaNbO${}_3$;NN) system is a series of alkaline niobate-based ceramics, which is lead-free antiferroelectric material over a wide temperature range of -100 to +360$^{\circ}$C that shows many phase transitions [1]. However, the pure crystallized NaNbO$_3$ ceramic was obtained at high calcination temperatures and showed poor homogeneity with large particle size[2]. In this work, the molten-salt technique was used for synthesis of NaNbO${}_3$ powder. The use of molten-salt in powder preparation is a method to control the size, shape and increase the rate of solid solution reaction[3]. The metal oxides of NaNO${}_3$ and Nb${}_2$O${}_5$ were mixed and ball-milled for 24 h and then mixed with NaCl:KCl salt. After that, the mixed powders were heated at temperatures from 800 to 1050 ${}^{\circ}$C. The phase structure and morphology of NN powders were investigated by using an X-ray diffractrometer (XRD) and a scanning electron microscope (SEM). The phase structure of NN powder corresponded to sodium niobate orthorhombic structure JCPDS file No.01-082-0606. The SEM images demonstrated that NN nano-crystals and agglomeration of particles were obtained. The results confirmed that NN nano-crystals have been successfully prepared by the molten-salt method. $\textbf{References}$: 1. S. Lanfredi, M. H. Lente, and J. A. Eiras, “Phase Transition at Low Temperature in NaNbO3 Ceramic,” Appl. Phys. Lett., 80 [15] 2731–3 (2002). 2. A. Wu, P. M. Vilarinho, I. M. M. Salvado, and J. L. Baptista, “Sol-Gel Preparation of Lead Zirconate Titanate Powders and Ceramics: Effect of Alkoxide Stabilizers and Lead Precursors,” J. Am. Ceram. Soc., 83 [6] 1379–85 (2000). 3. T. Kimura, “Molten Salt Synthesis of Ceramic Powders”, Advances in Ceramics- Synthesis and Characterization,Processing and Specific Applications,2011

Speaker: Mr Chavalit Suksri (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai, THAILAND 50200)

2:00 PM → 3:30 PM Special Session: Pesticide Biosensor (Sponsored by MTEC)

2:00 PM Portable pesticide analyzer: a project overview

2:15 PM ISFET: technical background and commercialization aspect

2:30 PM Acetylcholinesterase/gold nanoparticle/mesocellular foam silica biosensor for pesticide detection in real samples

Determination of pesticide residues in food, water, and the environment is crucial for the well-being of human and animals. This is because organophosphates and carbamates, two groups of widely applied pesticides in the agriculture, could inhibit cholinesterase enzyme which then may cause pyrolysis and finally death (Perry et al., 1998) to the livings. The main aim of this work is, therefore, to develop acetylcholinesterase (AChE)-based sensor for detection of pesticides in vegetables, fruits, and waters. Disposable screen-printed carbon and gold electrodes were both investigated as underlying substrates of modified electrodes. The electrodes were modified by immobilization of AChE in gold nanoparticle (AuNP)-decorated mesocellular foam silica (MCF), and the chitosan film was then cast over to cover the said nanoparticles. MCF is a type of mesoporous silica with remarkable specific surface area (can be up to 1,500 m2g-1;Ispas et al., 2008), appropriate pore sizes for enzyme immobilization and enhancing enzyme stability (Chouyyok et al., 2009). Moreover, incorporation of AuNPs helps enhancing electrical conductivity of the enzyme carrier. Interestingly, synergic effects between MCF and AuNPs tremendously enhanced current responses. The biosensors were tested for their performances with 4 types of pesticides, namely; chlorpyrifos, methyl parathion, carbaryl and methomyl. Primary tests with samples extracted from pesticide laden cabbage demonstrated that the biosensor could detect 500 ng/mL of methyl parathion. **References** A. Perry, S.I. Yamamoto, I. Ishaaya, R.Y. Perry, Insecticides in agriculture and environment retropspects and prospects. Narosa Publishing House, New Delhi (1998) 61. W. Chouyyok, J. Panpranot, C. Thanachayanont, S. Prichanont, Effects of pH and pore characters of mesoporoussilicas on horseradish peroxidase immobilization, Journal of Molecular Catalysis B: enzymatic 56 (2009) 246-252.

Speaker: Mr Nithi Thananukool (Department of Chemical Engineering, Chulalongkorn University, Phayathai Road, Wangmai, Patumwan, Bangkok 10330, Thailand)

2:45 PM AChE/agarose gel Coated on ISFET for Methyl-Parathion Sensors

A sensor for detecting pesticide by the inhibition of acetylcholine esterase (AChE) enzyme have been fabricated by direct immobilization in an agarose matrix on the surface of ion-sensitive field-effect transistors (ISFET). The enzyme entrapment was achieved by mixing AChE (0.01U) in an agarose gel buffer solution, and droping the mixture onto the surface of ISFET. This AChE-ISFET sensor was used to measure methyl-parathion in a phosphate buffer solution. The study of the agarose gel concentration (0.5%, 1.0%, 1.5% and 2.0%) and the storage time of sensor are reported. The device, which will be further explored in detecting other pesticides, is a promising pesticide sensor with simple preparation and capabilities to be developed as a portable device.

Speaker: Mr Supanat Sasipongpana (College of Nanotechnology, King Mongkut’s Institute of Technology Ladkrabang, 1 Chalongkrung Rd., Ladkrabang, Bangkok 10520, Thailand)

3:00 PM Imprinted expended gate Field-Effect transistor for pesticide detection

An extended gate field-effect transistor (EGFET) is a device that can be applied to chemical sensing with the benefit of low cost electrodes. A poly(methylmethacrylate) (PMMA)-imprinted film has been applied to fabricate on indium tin oxide glass as a gate electrode for an EGFET sensor for a specific detection of carbaryl sample. The imprinted film was obtained by mixing PMMA and carbaryl in dichloromethane and drop-cast on the EGFET electrode. Prior to measurements of carbaryl samples, the film was thoroughly rinsed with a low content of ethanol aqueous solution to remove carbaryl from the film. The carbaryl detection by the imprinted EGFET sensor was compared with that of the non-imprinted EGFET. The sensitivity, concentration range and specificity of the sensors were investigated. The imprinted EGFET has a high potential for low cost fabrication of easy-to-use pesticide sensors.

Speakers: Ms Piyawan Leepheng (College of Nanotechnology, King Mongkut's Institute of Technology Ladkrabang, 1 Chalongkrung Rd., Ladkrabang, Bangkok 10520, Thailand), Ms Sirikan Thongboon (College of Nanotechnology, King Mongkut's Institute of Technology Ladkrabang, 1 Chalongkrung Rd., Ladkrabang, Bangkok 10520, Thailand)

3:15 PM Water-gated OFETs for Pesticide Detection

Organic field effect transistors (OFETs) are widely utilized in alternative disposable electronic devices. These devices provide fabrication simplicity, low-cost, fast, and adequate sensitivity. A water-gated OFETs have been reported to operate under low-voltage with low-energy consumption and applied to DNA sensor. In this study, Bottom-contact top-gate water-gated OFETs were fabricated. Drain and source electrode materials were deposited by the thermal evaporation of chromium and gold respectively on glass substrate. Two configurations of electrode were used: standard and interdigitated pattern masks of which channel width and length ratios were varied and thermal evaporated for drain and source electrode. These masks were fabrication in our laboratory by contact printing. Poly(3-hexylthiophene) (P3HT) semiconducting layers were spin-coated using 1, 2 dichlorobenzene as a solvent on drain and source electrode. Deionized water droplets were applied as the dielectric layer for the devices. Gold gate electrode was dipped in deionized water on the top of device. The effects of channel width and length ratio on electrical characteristics of the semiconducting layers were investigated. It was found that the increasing channel width and length ratio improved the electrical performance of the water-gated OFETs. However, at short-channel lengths, the OFETs no longer saturate due to space charge limiting current effect. Changes in transistor characteristics when diluted pesticides were added to the water dielectrics were discussed.

Speaker: Mr Kroekchai Inpor (National Metal and Materials Technology Center (MTEC), Thailand Science Park, Pathumthani, THAILAND 12120)

Slides Full_manuscript_SPC2015.doc Full_manuscript_SPC2015.pdf

2:00 PM → 2:30 PM Statistical and Theoretical Physics

2:00 PM The relativistic-like Lagrangian : Multiplicative form

An alternative class of the Lagrangian called the multiplicative form is successfully derived. This new Lagrangian can be considered as a one parameter, namely the speed of light, extended class from the standard additive form of the Lagrangian since both yield the same Newtonian equation.

Speaker: Kittikun Surawuttinack (Department of Physics, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok, Thailand 10140)

2:15 PM Modified kinetic Monte-Carlo algorithm based on fluctuation theorem

Kinetic Monte Carlo (KMC) is an algorithm which finds transitions between states during an evolution of a system out of equilibrium according to the prescribed transition rate probabilities. One Major caveat with the original KMC is no attention that is given to how the system interacts with the environment. In particular, it is not known how the transition rate probability matrix plays a role in determining the heat exchange with the environment. To improve upon KMC, a fluctuation theorem is applied to KMC that connects the ratio of transition rate probability and its time conjugate to the entropy change of the environment. Our Modified Kinetic Monte Carlo (MKMC) algorithm chooses the next state in such a way as to obey the second law of thermodynamics. We apply the algorithm to solve the problem of Brownian heat engine operating between two heat baths. The result of the simulation is consistent with the analytic solution and the second law of thermodynamics.

Speaker: Mr Takol Tangphati (Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand)

2:30 PM → 4:45 PM Instrumentation, Metrology and Standards

2:30 PM Using relative gravimeter to determine vertical gravity gradients at NIMT

This work presents the method used to determine the vertical gravity gradients at National Institute of Metrology (Thailand), NIMT, using the relative gravimeter Scintrex Autograv CG-5. This value will be used to transfer the absolute gravity from the reference height of an instrument to a new specific position because the reference height of each absolute gravimeter is different depending on its construction that can be found between about 80 and 130 cm. Thus, in the comparison between absolute gravimeters, the measurement results must be corrected from the reference height of their gravimeters to the same reference level. That is why, it is necessary to determine the vertical gravity gradients as high accuracy as it is possible. In this work, three locations were selected to perform measurements that are two points at NIMT-Klong 5 (Pathumthani) and one point at NIMT-Rama 6 (Bangkok). The vertical gradient at each location was determined from linear fitting using the relative gravity values measured by CG-5 at five vertical levels above the ground benchmark. The results of gravity gradients found in this work range from 300.4 $\mu$Gal m$^{-1}$ to 320.4 $\mu$Gal m$^{-1}$ (1 $\mu$Gal = 10$^{-8}$ m s$^{-2}$) that the normal value of vertical gradient is 308.6 $\mu$Gal m$^{-1}$.

Speaker: Dr Tasanee PRIRUENROM (Pressure Laboratory, Mechanical Department, National Institute of Metrology (Thailand), Pathumthani, THAILAND 12120)

Slides Gravity_gradient_at_NIMT.pdf

2:45 PM Development of AC High Voltage Measurement System with Digital Technique at NIMT

This paper describes how to develop, test and evaluation of an AC High Voltage Measurement System 70 kV with digital technique at NIMT. The purpose of the development is to make national standard more reliable for quality assurance. The AC HV Measurement System consists of a Capacitive-High Voltage divider, Measuring cable and high precision Digital Multi-Meter. Its nominal scale factor is 10000:1. A 100 pF compressed gas capacitor is series-connected with a 1 micro-F low voltage standard capacitor to form the Capacitive-High Voltage divider. The measuring cable conducts a voltage signal from low voltage standard capacitor to a high precision Digital Multi-Meter. The high precision Digital Multi-Meter operates in digitizing mode to sample a voltage signal. The homemade program is designed to control the high precision Digital Multi-Meter to sample a voltage signal at the sampling rate greater than Nyquist rate from an output of the Capacitive-High Voltage divider, and calculate the values of sampled signal. The high precision Digital Multi-Meter with program is verified by a traceable ac voltage source. The results show that the measured value agrees within 70 ppm. After that, the high precision Digital Multi-Meter with program is connected to the Capacitive-High Voltage divider via a measuring cable. The AC High Voltage Measurement System is evaluated according to IEC 60060 by a well-calibrated national standard. The result shows the agreement within 0.2 %.

Speaker: Dr Chatchaval KURUPAKORN (Electrical Metrology Department, National Institute of Metrology (Thailand), Pathumthani, THAILAND 12120)

3:00 PM Preliminary Study for the Establishment of Oscillation-Type Density Meter Calibration at NIMT

Density meters have been employed to measure the density of liquids and used in many areas such as chemical, petroleum, pharmaceutical and beverage applications. The advantages of density meters over other density measurement devices are their fast measurement, high accuracy and little sample needed. Although high accuracy is one of their major features, the density meters need regular calibration to ensure the accuracy of their measurement results. National Institute of Metrology (Thailand), NIMT, studied the calibration of density meters in accordance with the international standard ISO 15212-1. In this paper, the studied technique was applied to the calibration of oscillation-type density meters. The calibration performed at the temperature of 20 °C was traceable to SI unit by using traceable standard liquids with known densities. Three types of the liquids, whose densities are within the density measuring range of 700-1600 kg/m$^3$, were employed. Those liquids were lube oil, water and sodium bromide in water. The calibration results were presented in terms of the deviations between the measured densities and the certified densities reported in certificates of standard liquids. Also the sources of measurement uncertainty were proposed and calculated. The calibration results showed acceptable deviations, which were within the maximum permissible errors of density meters under test.

Speaker: Dr Chompoonoot HIRUNYAPRUK (Mechanical Metrology Department, National Institute of Metrology (Thailand), Pathumthani, THAILAND 12120)

3:15 PM Determination of Density According to Test Method A1 (Two Different Reference Weights Weighed in Air) of OIML R111-1, 2004(E)

Density of standard weights is one of many parameters that have the influences on the mass determination of the weights. As it is used to calculate the air buoyancy correction, which is an important factor to precisely determine the mass of the weights. According to the International Organization of Legal Metrology (OIML) recommendation R 111-1, 2004(E), there are six accepted methods for the determination of the density of standard weights. Those are methods A, B, C, D, E and F. For the first four method, the test weights are weighed in standard density liquids such as water. Method E determines volume and hence density by geometric measurement, while the density estimation of method F is based on known composition. Among these six methods, method A is the most accurate. Method A uses hydrostatic technique, which compares test weights with reference weights both in air and in liquid of known density. This method can be separated into three methods, which are A1, A2 and A3. However, only method A1 is mentioned in this work. The technique used in method A1 is that the test weight and the first reference weight are firstly compared in air. Then, the test weight in liquid is compared with the second reference weight in air. The test weights used in this work are weights class E having mass between 5 g and 100 g. These weights are manufactured by stainless steel. In this paper, the densities with expanded uncertainty (for $k$ = 2) of these test weights are determined and reported. The uncertainties obtained are within specification of OIML R111-1, which is between 1.5 kg.m$^{-3}$ to 60 kg.m$^{-3}$. The measured densities are compared with those obtained from the method accredited by the Accreditation Body of Deutsche Akkreditierungsstelle (DAkkS), ISO/IEC 17025, on the registration number D-K-15194-01-00. Results obtained from both methods are consistent as shown by En numbers. The absolute En numbers is not greater than 1.0, which is satisfied.

Speaker: Mr Wirun Laopornpichayanuwat (Mechanical Metrology Department, National Institute of Metrology (Thailand), Pathumthani, THAILAND 12120)

3:30 PM Development of a shear-wave generator for shallow seismic investigation

Shear wave velocity is a fundamental parameter in determining geological structures and soil characteristics for geotechnical and earthquake engineering studies. Shear wave velocity can be obtained from the conventional surface seismic method such that the shear wave is generated by the seismic source and the refracted and reflected energies are recorded by the array of geophones. We report here on the design and development of an effective shear wave seismic source that will be alternatively used for shallow seismic survey. Structure of the developed source consists of 4 main parts, including base plate, activated mass, lifting and shooting system, body and transportation system. It is operated based on a simple mechanical system by lifting an activated mass with an attached sling and puller. When the mass reach the armed position and spring is under compression, the potential energy is stored. After the mass is released and horizontally hit the base plate, shear wave is generated by the momentum and energy transfer into the ground. To evaluate the source performance, a comparison test of the conventional shear wave sources and the developed source was performed at a test site. Data were analyzed in both qualitative and quantitative manner by examining the physical properties and visualizing the raw data, comparison of energy, frequency content, signal penetration and repeatability. It was found that the developed source produces the higher energy and repeatability than the conventional source and allows for a reducing the man power requirement. Overall, our apparatus has potential application and is suitable for teaching, research and academic service purposes.

Speaker: Dr Sawasdee YORDKAYHUN (Department of Physics, Faculty of Science, Prince of Songkla University, Hatyai, THAILAND 90112)

3:45 PM Influence of form deviation to diameter measurement of cylindrical master

Cylindrical masters such as plug gauges and ring gauges are commonly used in manufacturing process as the physical diameter standard. Diameter of the cylinder is defined in the JIS B 7420 by means of distance between two opposite edges measured by the length measuring instrument. The standard method descried that length shall be measured two directions perpendicular each other in the cross section in multiple layers. And the diameter is calculated from the arithmetic mean between all measured values. However, the mean diameter does not represent the diameter when it is used for working gauge inspection because form deviations have an effect to gage wear. This paper investigates the influence of form deviation of the cylindrical masters by using roundness tester, universal length measuring machine (ULM) and coordinate measuring machine (CMM). The results show the form deviation effect to the diameter of cylindrical masters and error should be included in uncertainty of measurement of mean diameter.

Speakers: Jariya Buajarern (National Institute of Metrology (Thailand), Pathumthani, THAILAND 12120), Narin Chanthawong (National Institute of Metrology (Thailand), Pathumthani, THAILAND 12120)

4:00 PM Development of microwave-infrared drying system for industrial prototype of STR20 production

Rubber block STR20 is a natural rubber product which has highest market need for both locally and internationally. STR20 is used as raw materials for various industries, such as tire, conveyor, elastomeric bearing pad and shockproof rubber case. Drying process is the most important in the rubber block production, which also consume the most of energy use. Typically, the dryers use hot air, supplied by the combustion of fuel oil or LPG, to remove the moisture from rubber granules, before compression for STR20 rubber block. Normally, the drying time is longer than 3 hours, since the heat transfer occurs slowly inside the rubber granule. There have to be temperature gradient between surface and inside of the granule for the heat transfer. Because of energy loss by ambient air and the dryer’s wall, hot air dryer has low energy efficiency. Development of new drying technology by using microwave will increase the energy efficiency, reduce the drying time and increase the quality of the rubber block. The microwave can heat the rubber granule uniformly, without energy loss to the air and the environment. In this research, we have developed drying system by using combined microwave-hot air process. The hot air will heat up the surface, while microwave will cause the high temperature inside, resulting as uniform heating of the granule. The drying time is shorter and the quality of the dried rubber is better. For the drying capacity, rubber bed-depth is greater than 30 cm, and drying rate is more than 30 kg/h. The drying technology has potential for development of industrial prototype of STR20 rubber block production in the future.

Speaker: Dr Mudtorlep Nisoa (Division of Physics, School of Science, Walailak University, Nakhon Si Thammarat, THAILAND 80161)

4:15 PM Discover the New Reality for Your Analytical Electron Microscope

In this presentation, the latest 5-on-1 system for SEM will be introduced. The presentation will focus on the four channel SDD FlatQUAD EDS, XTrace micro-XRF and micro-CT systems, and briefly discuss on the new developments on EBSD and WDS. Quantax FlatQUAD is the EDS microanalysis system based on the revolutionary XFlash® FlatQUAD. This special annular four-channel silicon drift detector is inserted between SEM pole piece and sample, achieving maximum solid angle (>1.1sr) and take off angle (>60o), allowing maximum input count rates (ICR) (up to 4,000,000 cps) and output count rate (OCT) (up to 1,600,000 cps) for low KV (3kV) and probe current (<10pA) EDS analysis. XTrace is a micro-spot X-ray source for attachment to SEM with a free inclined port on the specimen chamber. It adds the capabilities of a complete micro-XRF spectrometer to the microscope. Limits of detection are improved 20 to 50 times in the mid to heavy element range. Additionally, up to 1cm information depth become accessible as X-rays have a higher penetration power than electrons. With ESPRIT analytical software suite, a combined micro-XRF and EDS quantification provides reliable light element results and pushes the limit of detection of medium to heavy elements down to 10 ppm, which offers the highest quality attainable by energy-dispersive analysis. Micro-CT for SEM adds true 3D microscopy to your SEM with visualization as three orthogonal sections or as slice-by-slice movie. It extends the surface information gained with conventional SEM imaging by allowing a unique insight into a specimen’s internal microstructure down to a size of 400nm non-destructively.

Speaker: Alex Wong (Bruker Singapore Pte. Ltd., 11 Biopolis Way, #10-10, Singapore 138667)

4:30 PM Controlling output signal of frequency generator for NMR

NMR frequency generator was built using digital frequency generator (PTS310) and AVR microcontroller. The microcontroller was programmed to receive a frequency value from computer. After processing, the microcontroller sent 24 parallel data bits to control the digital frequency generator (PTS310). The frequency value is restricted between 0-16 MHz. It was found that the output frequency can be controlled from 0.00000 MHz to 9.70129 MHz. The error of output frequency is 0.20%.

Speaker: Mr Klitsadee Yubonmhat (Department of Physics, Faculty of Science, Khon Kaen University, 40002, Thailand)

3:30 PM → 5:30 PM High-Energy and Particle Physics

3:30 PM N=2 seven-dimensional SO(4) gauged supergravity from eleven dimensions

A consistent reduction ansatz of eleven-dimensional supergravity to $N=2$ $SO(4)$ seven-dimensional gauged supergravity is constructed. The resulting seven-dimensional theory admits a topological mass term for the three-form field and a maximally supersymmetric $AdS_7$ critical point. This is in contrast to the gauged supergravity without topological mass admitting a half-supersymmetric domain wall vacuum. The $AdS_7$ critical point corresponds to $N=(1,0)$ superconformal field theory in six dimensions according to the AdS/CFT correspondence. The reduction ansatz is obtained from a truncation of the consistent $S^4$ reduction giving rise to the maximal $N=4$ $SO(5)$ gauged supergravity, so the consistency is guaranteed by the consistency of the $S^4$ reduction.

Speaker: Dr Parinya Karndumri (Department of Physics, Faculty of Science, Chulalongkorn University)

Slides SPC2015_talk.pdf

4:00 PM Theoretical constraints on additional higgs bosons

We present a sum rule for Higgs fields in general representations under $SU(2)_L \times U(1)_Y$ that follows from the connection between the Higgs couplings and the mechanism that gives the electroweak bosons their masses, and at the same time restricts these couplings. Sum rules that follow from perturbative unitarity will require us to include singly and doubly charged Higgses in our analysis. We examine the consequences of these sum rules for Higgs phenomenology in both model independent and model specific ways.

Speaker: Patipan Uttayarat (Department of Physics, Faculty of Science, Srinakharinwirot University, Bangkok 10110, Thailand)

Slides patipan.pdf

4:15 PM Search for the standard model Higgs boson produced by vector-boson fusion and decaying to bottom quarks

A search for the standard model Higgs boson in the vector boson fusion production channel with decay to bottom quarks is reported. A data sample comprising 19.8 fb$^{-1}$ of proton-proton collisions at $\sqrt{s}$ = 8 TeV collected during the 2012 running period has been analysed and 95$\%$ confidence level upper limits on the cross section are derived in the mass range from 115 to 135 GeV. For a Higgs boson mass of 125 GeV the expected limit is 2.6 times the predicted standard model cross section, while the observed limit is 5.6. The excess corresponds to a fitted signal strength of 2.8$^{+1.6}_{-1.4}$, relative to the expectation for the standard model Higgs boson.

Speaker: Gurpreet Singh (Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok 10330 , Thailand)

Slides VBF_Hbb_Gurpreet_Indico.pdf

4:30 PM Development of Charm quark Tagger at the CMS Detector

Various final state channels at, the Compact Muon Solenoid (CMS), contain charm quark jets. Charm quarks can be hadronized to D mesons which could travel some distance in the tracker before decaying, providing the displaced tracks and vertices. The CMS silicon tracker allows the precise reconstruction of such vertices and tracks that are displaced with respect to the primary interaction point. The identification of charm jets or "c tagging" algorithm is constructed based on the b tagging algorithms. Particle Physics Research Laboratory at Chulalongkorn University, as a part of the c tagging team, is currently studying the c tagging algorithm in order to maximize the performance. This study will be vital for both supersymmetry (SUSY) searches such as stop (${\tilde t}$), the SUSY partner of standard model (SM) top, that may subsequently decay to a charm quark and the lightest supersymmetric particle (LSP) and for SM precision measurements in the new data taking at the Large Hardron Collider (LHC) in 2015.

Speaker: Kittikul Kovitanggoon (Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok 10330 , Thailand)

Slides SPC2015_talk.pdf

4:45 PM Projections at 14 TeV for Dark Matter Searches in the monojet final state using the upgraded CMS Detector

The projections of limits for dark matter searches studying from the final states containing a monojet and missing transverse energy at the upgraded LHC are discussed. DM-sample events are generated using MadGraph. In addition, DELPHES simulations at 14 TeV are used to estimate signal and backgrounds to set the limits on DM nucleon cross sections. Additional simple projections using generator level analysis are also carried out to compare to the DELPHES analysis.

Speaker: Apichayaporn Ratkata (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand)

5:00 PM Dynamical Casimir Effect in an Oscillatory Cylindrical Cavity on a Magnetized Background

It has been found that the external magnetic field can induce particle creations from vacuum fluctuations of quantum electromagnetic field. This indicates that the quantum fluctuations associated with one loop corrections can be amplified by an intense magnetic field. It is interesting to consider the particle creation process in the dynamical Casimir effect on a magnetized background. In this work, we apply the Euler-Heisenberg action, the effective action dominated by the one loop correction term, to deal with the quantum electromagnetic field in the cavity with non-stationary boundary condition. The number of created photons are determined in the process with an oscillating cylindrical conducting wall, which is in a uniform magnetic field parallel to the wall. We also discuss the effect of the external magnetic field on particle creations in the dynamical Casmir effect.

Speaker: Dr Ekapong Hirunsirisawat (Office of Engineering Science Classroom, Learning Institute, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand)

5:15 PM Photon Generation in a One Dimensional Oscillating Cavity with a Uniform Magnetic Field

The vacuum of quantum electromagnetic field can be excited in the form of photon creation via the interaction with moving boundaries. This is so-called the dynamical Casimir effect. It is well known that the external magnetic field can result in the amplification of the quantum fluctuations of electromagnetic field. In the present work, we therefore consider photon creations from the dynamical Casimir effect in a one dimensional cavity between two parallel moving conducting plates with the presence of a uniform external magnetic field. Starting with the Euler-Heisenberg effective action, the quantum electromagnetic field operator is written as the expansion of mode functions, which are the classical solutions corresponding to the effective Lagrangian. By calculating Bogoliubov coefficients, the number of created photons is determined in the resonance condition. With the presence of a uniform magnetic field, photons are generated with larger amount than that in the case of no magnetic field.

Speaker: Kittipong Aimsamer (Department of Physics, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok, Thailand 10140)

3:30 PM → 4:45 PM Biological Physics and Biomedical Engineering (Sponsored by MTEC)

3:30 PM Hydroxyapatite and Ceramic Composite Coatings by Novel Plasma Spraying Technology for Bio-Medical Implant Application

Hydroxyapatite (HA) coated implants have promising bioactive properties and biocompatibility of HA with bone in orthopedic and dental surgery. The advantages of HA coating on implants is those, such as a more rapid and stable fixation of the implant to the bone, stronger bonding between the bone and the implant, increased uniform bone in growth at the bone implant interface and decreased release of metal ions from the implant to the body, etc. The plasma sprayed HA coatings generally contain cracks, pores, second phases, and residual stresses. Those affect the in-vivo performance of HA coatings due to both composition and crystallinity. Therefore, the control of the micro-structure of the HA coatings is the main target to develop the high performance implants for bio-medical applications. The gas tunnel type plasma spraying developed by the author is a novel plasma technology, which has properties such as high thermal efficiency of 80%, high temperature and high energy density, relatively high deposition rate, prevention of in-flight decomposition, minimized oxidation due to higher amount of working gas, and so on. Therefore, the gas tunnel type plasma spraying enables to obtain not only high quality ceramic coatings, but also HA coatings in a short spraying time. By observation of SEM micrographs of HA coatings sprayed at different arc current, the pores appeared in the HA coating sprayed at low arc current, and HA coating became high dense with few pores at high arc current. This means the good controllability of the microstructures of HA coatings by this novel plasma spraying method. Crystalline HA coating was achieved through gas tunnel type plasma spraying under optimum spraying conditions. Furthermore the gas tunnel type plasma spraying method was successfully employed to produce HA and YSZ reinforced HA coatings on 316L stainless steel substrate. The reinforcement of YSZ in HA significantly reduced the porosity and consequently increased the coating hardness and enhance the adhesive strength. The potentiodynamic polarization and impedance measurements showed that YSZ reinforced HA coatings have superior corrosion resistance compared to the pure HA coating in SBF solution. The cell culture results revealed that the reinforced YSZ coating has improved the bioactivity of the HA coatings. As another method to enhance the HA coating performance, lanthanum oxide (La2O3) was mixed with Hydroxyapatite (HA) powder. The addition of La2O3 in HA significantly reduced the porosity and consequently increased the coating hardness and enhanced the adhesive strength and wear resistance.

Speaker: Akira Kobayashi (MJIIT, University of Technology Malaysia KL, Jalan Semarak 54100, Malaysia; Graduate School of Engineering, Osaka University, Osaka 565 0871, JAPAN)

4:00 PM Determination of Unconjugated Estriol by Using Surface Plasmon Resonance (SPR) Biosensor

Unconjugated estriol (uE3) is one of the estrogen hormone produced in significant amount during the pregnancy. It can be measured in maternal blood and its level can be used as a marker for screening the down syndrome. An abnormally low level of uE3 indicates a chance of baby suffering from a down syndrome, lower than 0.68 ng/mL in the second trimester. The main objective of this work is to develop the technique for maternal serum screening for uE3 by using surface plasmon resonance (SPR) technique. uE3 is a small molecule and it is very difficult to detect directly by SPR; therefore, the inhibition assay was chosen for the study. The inhibition assay was done by mixing uE3 sample with known amount of the antibodies. The free antibodies bind with the uE3 in the premixed sample causing the reduction of the free antibodies. Therefore the higher the uE3 presented in the sample, the lower the free antibodies in the mixed sample. The amount of the uE3 was quantified against the standard curve. The possibility of regenerating the sensor chip up to 3 cycles were achieved.

Speaker: Kitti Boonperm (Materials Science and Engineering Program, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand)

4:15 PM Free human Chorionic Gonadotropin beta (hCGβ) detection of The Triple Test for Down’s syndrome screening in maternal serum using Surface Plasmon Resonance Technique (SPR)

It is well-known that the principle of surface plasmon resonance (SPR) based sensing is based on the detection of a small refractive index change on a thin metal film caused by complex formation between biomolecules such as antigen–antibody complexes. Therefore, the SPR-based immunoassay has often been employed to extend its application to the clinical diagnosis for the detection of biomarkers in low concentration in human blood with accurate and rapid results. In this study, SPR technique was used to detect free human Chorionic Gonadotropin beta (hCGβ) level in pregnancy serum that is one of the major markers for Down’s syndrome screening. The detection limit that should be detected for Down’s syndrome is at the nanogram level that it is necessary for clinical diagnosis. The platform as sandwich immunoassay used three types of antibody, monoclonal anti hCGβ antibody as primary antibody, polyclonal anti hCGβ antibody as secondary antibody and gold nanoparticles conjugated polyclonal anti IgG as third antibody for signal enhancement. Those antibodies were performed on a carboxymethyl dextran sensor chip. An optimum condition of antibody immobilization on dextran surface was obtained by using antibody with concentration of 20 μg/mL prepared in an acetate buffer solution at pH 4. Under the above condition, relatively high intensity of SPR signal was achieved in comparison to those obtained at other pH (3, 5 and 6). This SPR based sensor showed that the detection limit was at 30 ng/mL of concentration. Moreover, the hCGβ detection in maternal serum samples without non-specific absorption of other proteins in matrix was succeeded at 1/50 dilution. **References**: J. Homola, Present and future of surface plasmon resonance biosensors, 2003, 377, 528–539.

Speaker: Phatra Khomkrachang (Materials Science and Engineering Program, Faculty of Science, Mahidol University, Bangkok, THAILAND, 10400)

4:30 PM The Synthesization of biocomposite materials of Hydroxyapatite/beta-tricalcium phosphate/biopolymer scaffold for bone tissue regeneration

Loss and damage of bone tissue is the one of the most troubling problems that jeopardize human health. Therefore, over the past decade, synthesization biocomposite materials for bone tissue engineering is becoming increasingly interested. In this study, Bio-composite material composed of hydroxyapatite/beta-tricalcium phosphate (BCP) (inorganic) and chitosan/alginate (ChiAlg) (organic) (BCP@ChiAlg) with the three different ratios of 1:1, 2:1 and 3:2 wt/wt (chitosan/alginate) were synthesized. The mechanical properties and the in vitro growth of rat osteoblast-like UMR-106 cells were investigated. The results indicate that the mechanical strength and bioactivity are controlled by the chitosan and alginate ratio. The obtained result from this study shows the composition of 3:2 by wt ratio is the most effective ratio with the compressive strength of 6.31 MPa. It was obtained the significant increase in cell availability and high cell activity. These characterizations reveal that a composite of BCP@ChiAlg is one of interested biocomposite materials for application in bone tissue engineering.

Speakers: Mr Chawit Chaijirawiwat (Department of Physics, Mahidol Wittayanusorn School, Thailand), Mr Metha Trikasemmart (Department of Physics, Mahidol Wittayanusorn School, Thailand), Mr Tanasate Naphathrathorn (Department of Physics, Mahidol Wittayanusorn School, Thailand)

5:30 PM → 6:30 PM Thai Physics Society Annual Meeting

6:30 PM → 8:30 PM Siam Physics Congress Annual Banquet

Thu, May 21

8:00 AM → 11:00 AM Poster-2

8:00 AM A Second-Quantization Approach to the Analytical Faraday Effect in Graphene

We investigate coherent single photon traveling in the positive $z$ direction passes through a graphene film subjected to a transverse magnetic field $B$. Analytical expressions are obtained for the transmission and reflection coefficients by full second-quantized form. Giant Faraday rotations in the infrared regime are generated and measurable Faraday rotation angles in the visible range become possible. For an example, this explains the departure from the semiclassical value for $\theta_F$ observed in the right panel in $B\approx $ 1 T for $\hbar \omega =$ 10 meV ($B\approx$ 0.5 T for $\hbar \omega =$ 30 meV). If the magnetic field intensity is higher than a given value, we necessarily have $N_F =$ 0 (for 0.05 eV this value is about 1.9 T). In this case, the Hall conductivity at $T =$ 0 is fully determined by a single type of interband transition, and assuming $E_1 (B) \gg \hbar\omega$, we obtain $\theta_F\approx$ 3 $\times$ 10$^{−4}$.

Speaker: Mr Phusit Nualpijit (Department of Physics, Faculty of Science, Kasetsart University, Bangkok, THAILAND 10900)

8:00 AM A Study of Capacitively Coupled Contactless Conductivity Detection (C$^4$D) Electrode Configurations on Signal Detection Sensitivity

Capacitively Coupled Contactless Conductivity Detection (C$^4$D) technique has been widely used in detecting particles of interest in microfluidics applications. In this technique, change of solution conductivity is detected when particles in solution flow pass electrodes. Detection sensitivity depends on electrodes and microfluidic channel configuration. Influenced electrode geometries include electrode dimensions, detection area, and thickness of the wall separating electrodes and the channel. Various sizes and shapes of C$^4$D electrodes fabricated using printed circuit board patterning technique and arrangements between electrodes and channel were used in determining detection sensitivity when particular particles in solution pass through. The sizes of the electrodes fabricated for this study were 50, 90, and 150 microns. The C$^4$D electrodes were tested with the various oil droplet sizes in water. It was found that the electrodes could be used to detect the oil droplets of size down to about 100 microns.

Speaker: Mr Korkuson Masean (Department of Physics and Materials Science, Faculty of science,Chiang Mai University, Chiang Mai, 50200, Thailand)

8:00 AM An Effective Hands-On Experiment in Light and Optics for Grade 10 Students

This research aimed to develop and implement a set of hands-on experiment in light and optics. The subjects were 38 tenth grade students in an extended high school of Supanburi province on academic year 2014. The instruments used were a set of hands-on experiment in light and optics, the Light and Optics Conceptual Evaluation (LOCE) test, and student experiment’s report. The data were analyzed by calculating average, standard deviation, t-test and average normalized gain. The result indicate that the students’ conceptual understanding of the light and optics were higher in posttest than those in pretest (p< .05). The average class normalized gain was at the medium gain level (g = 0.67). The study illustrated that a hands-on experiment is effective and can be used to develop students’ concepts.

Speaker: Ms Sujitra Khuntee (krujeabza@hotmail.com)

8:00 AM Analysis of Biological Effect inside Human Body Exposed to Extremely Low Frequency due to Overhead Transmission Lines

In Thailand, the extra high voltage 500 kV and 50 Hz overhead transmission lines have been installed by Electricity Generating Authority of Thailand (EGAT) both of single-circuit and double-circuit due to the rapid increasing of electrical power demands. The electromagnetic field will be generated and propagated to the environment in the area around overhead transmission lines. The intensity of electric field and magnetic field are proportional to the voltage of transmission lines. There is concern about the harmful effects on human which is exposed to electromagnetic field due to these overhead transmission lines. The biological effect on human body in case of high voltage and extremely low frequency electric field is induced current density. Some human organs, such as hearts and brains, are able to function by utilizing weak electricity. There may be some harmful effects to these organs if the current density exceeds the safety limit. The safety limit values of electric field and current density were set by the International Commission of Non Ionizing Radiation Protection (ICNIRP), electric field is 5 kV/m and current density is 2 $\mu$A/m$^2$ for general public exposure. In this work, the numerical analysis base on Finite Element Method is used to calculate the electric field intensity around overhead transmission lines and induced current density on human body standing under overhead transmission lines. Therefore, the induced current density on several organs such as lungs, heart, liver and intestine inside human body exposed to extremely low frequency electromagnetic field at 13 positions under single-circuit overhead transmission lines are investigated. These values will be compared to the safety limits. It is found that the incident electric field on human body and induced current density on some organs inside human body are higher than those of the safety limits for general public exposure, especially the body at mid-span of the tower.

Speaker: Mr Apichart Siriwitpreecha (Department of Industrial Physics and Medical Instrumentation, Faculty of Applied Science, King Mongkut’s University of Technology North Bangkok, Bangkok 10800, Thailand)

8:00 AM Analysis of Students’ Task Relating to Boyle's law, Charles’s law and Kinetic Energy for Gases.

The purpose of this study was to examine student responses to a task relating to Boyle's law, Charles’s law and kinetic energy for gases, which did not demand the use of a mathematical equation for its solution. The target group was 33 students in grade 11 from Ummaoprachasan School, Amphur Thatphanom, Nakhonphanom province. All students studied in the second semester of academic year 2014. The group pretest-posttest design was employed in this study. The research instruments consisted of lesson plans based on peer instruction, diagnostic test, and a set of experiments relating to Charles’s law and kinetic energy for gases, respectively. The data were analyzed by using the average percentage, standard deviation and t-test.

Speaker: Mr Pattarawut Chaweewong (Department of physics, Faculty of Science, Ubon Ratchathani University, Thailand, 34190)

Paper นำส่ง_Using_Simple_Hands-on_Experiments_to_Develop_Students’_Concept_on_the_Kinetic_Theory_of_Gases.docx นำส่ง_Using_Simple_Hands-on_Experiments_to_Develop_Students’_Concept_on_the_Kinetic_Theory_of_Gases.pdf

8:00 AM Application of Role-playing Game Strategies in Teaching and Learning High School Physics

The National Statistical Office reported that persons between 15 and 24 years used the internet more than other groups, with 65.4% of their time being spent playing online games, especially role-playing games (RPG). Examples of RPG are Ragnarok and Dungeons and Dragons. A RPG is a game in which each participant assumes the role of a character generally in a fantasy or science fiction setting that can interact within the game's imaginary world. RPG is a type of cooperative game play that promotes creativity and teamwork specifically. The use of RPG in the classroom has become accepted by educators. In this research, the prominent characteristics of RPG were applied into the design of teaching and learning sequences that involved the completion of missions such as solving problems, quests, and conversations, and teaching others. The participants in the study were 29 grade 10 students in grade ten in Srisaket province. Results showed a strong positive relationship between students’ experience levels and achievement scores after application of RPG Strategies in teaching and learning. Therefore, it can be concluded that the teaching and learning sequences were effective.

Speaker: Mr ratapon kamkaen (Department of physics, Faculty of Science, Ubon Ratchathani University, Thailand, 34190)

Slides Role-playing_Game1.docx Role-playing_Game1.pdf

8:00 AM Applying Michelson Interferometer for Coherence Length Measurement of Laser Light

In this work, a Michelson Interferometer was applied for the measurement of coherence length of He-Ne laser (632.8 nm), blue diode laser (404.5 nm), green diode laser (532.5 nm) and red diode laser (656.5 nm). The principle of coherence length measurement is based on the formation of interference fringes obtained from Michelson interferometer. The laser beam is expanded by a beam expander and passes into Michelson interferometer. The laser beam is divided into two beams by a beam splitter. The two beams, are reflected at mirror M1 and M2, and then interferes to form interference fringes as can be seen by the eye. The Michelson interferometer can be used to measure coherence length of laser light directly by measuring the maximum path difference over which we still observe the interference fringe. The coherence length of He-Ne laser (632.8 nm), blue diode laser (404.5 nm), green diode laser (532.5 nm) and red diode laser (656.5 nm) are found to be 0.85, 0.18, 0.3 and 0.45 mm, respectively. The results are in good agreement with those of theoretical calculations, i.e. 0.8, 0.16, 0.28 and 0.43 mm.

Speaker: Mr Pornchai Kopatta (Department of Physics , Mahidol Wittayanusorn School , Thailand)

8:00 AM Applying the Michael and Wittmann’s Framework to Analysis of the Force and Motion Conceptual Evaluation Test

In the last three decades, much work has been done regarding the identification of students’ misconceptions in fundamental physics, especially related to the topic of force and motion. Many of these misconceptions are widely shared and re-appear in different groups of students. For example, many students believe that the net force on an object is proportional to its velocity rather than its acceleration, an object with a larger initial speed exerts more force than an object with a smaller initial speed during a collision, and heavier objects exert more force than lighter ones. It has also been shown that traditional instruction is relatively ineffective in correcting these misconceptions or in helping students develop more appropriate ways of thinking. In this research the active teaching and learning modules in the force and motion concept section were designed and implemented into a high school classroom in Kalasin province. The students’ conceptions before and after teaching were assessed with the Force and Motion Conceptual Evaluation test (FMCE). The results found that only a small percentage of high students grasped Newtonian concepts.

Speaker: Mr Suriya Chalermchat (Department of physics, Faculty of Science, Ubon Ratchathani University, Thailand, 34190)

8:00 AM Automatic Marking System for Basic Physics Laboratory

We have developed a system that can automatically give a score to a student laboratory report. Even the system can be used in general, we aim our work mainly to the basic physics laboratory. We take the advantage of the existing Google doc by designing a cloud document for the students to submit their reports. This can be very convenient since the students can submit their works via any platforms of their smart devices. The reports are kept in the form of spreadsheet, which can be analysed by the macro langauge like VBA or Openoffice.org BASIC. The score is given base on the discrepacy of the results reported by the students and the values from the sensors. We use the single board Raspberry Pi as our workstation to analyse the reports by comparing with the experimental values. As a prototype, we connect our Pi with the camera module to create a motion tracker, which we use to track the motion of objects or reading the dial indicator. By using the free-of-charge cloud document and the tiny, but powerful, Raspberry Pi workstation, our system is not so pricely and very suitable for the large laboratory classes. We expect that this should help the instructor of the basic laboratory in their tedious but very importance jobs. Our system should also reduce the bias from the different instructors and gives a fair check to the student reports

Speaker: Dr Noparit Jinuntuya (Department of Physics, Faculty of Science, Kasetsart University, Jatujak, Bangkok 10900, Thailand)

Poster Poster-SPC2015.pdf

8:00 AM Calculation of Average Charge Number on the Single Electron Transistor by Quantum Monte Carlo Method

The average charge number on the metallic single electron transistor due to the effect of Coulomb Blockade and Electron Tunneling at any temperature is calculated by using path integral Monte Carlo (PIMC) approaches. The results show that those effects are the most prominent at low temperatures, i.e. $\beta {E_C} > 1$. Additionally, the efficiencies of the Single Site Update Algorithm (SSU) and Fast Fourier Transform Algorithm (FFT) techniques are compared. We found that the FFT technique needed significantly less processing time that SSU method. In essence, the processing time of the FFT technique was approximately $38\%$ of that of the SSU method.

Speaker: Mr Tawan Thongsuk (Theoretical Condensed Matter Physics Research Unit, Department of Physics, Faculty of Science, Mahasarakham University, Maha Sarakham, THAILAND 44150)

8:00 AM Cambodian Students Understanding of Forces and Motions: A Comparison with US, Australian, Japanese and Thai students

This research aims to explore Cambodian students’ understanding of forces and motions using the force and motion conceptual evaluation (FMCE) test. The 43 items of FMCE, excluding an energy concept, were translated into Cambodian language, validated by experts, and modified to reach a statistically acceptable version. After that, the assessment instrument was applied to 73 tenth graders of a medium- sized school located in the central region of Cambodia. These students have learn the forces and motions via a lecture-based conventional teaching method. Results showed some students’ misconceptions, for examples, around 70% of these students believed that for a moving object, a force is always in a direction of its velocity. They also claimed that an acceleration is proportional to a velocity. Moreover, most believed that during an interaction of two objects, the object of the greater mass (or velocity) can exert the greater force to the other. A cluster of Newton’s 1st and 2nd laws was the most problem of these Cambodian students. When we analyzed four sets of questions in this cluster, it revealed that the coin toss and the cart on ramp contexts were the most difficult questions of the students. Moreover, when we compared the results of Cambodian students with published FMCE results collected from US, Australian, Japanese and Thai students, we found a very similar trend of students’ ideas. This preliminary outcome will be used as a primary resource to design instructional media for Cambodian students in a following part of our research.

Speaker: Mr Seng Khun Beang (Department of Physics, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, THAILAND 90110)

8:00 AM Carbon screen-printed electrode/Graphene-PEDOT:PSS/Prussian blue/PEDOT-AuNPs for electrochemical immunosensor application.

Fast, reliable, inexpensive, and efficient pathogen detection for diagnostic purposes has always been a high priority in healthcare industry, leading to research for alternative diagnostic methods. An approach that is prominent and has all said characteristics is electrochemical-based immunosensors. Recently, Graphene has gained a lot of interest in electricity-related fields due to its high electrical conductivity and other favorable properties, which could increase electrochemical response as well. The objective of this work is to develop graphene-based carbon screen-printed electrode for immunosensing. Initially, Graphene-Poly(3,4-ethylenedioxythiophene) Polystyrene sulfonate (GR-PEDOT:PSS) was drop-coated on the surface of carbon screen-printed electrodes. Prussian blue nanoparticles were subsequently electrodeposited as the redox mediator. The electrodes may be drop-coated with GR-PEDOT:PSS and electrodeposited with Prussian blue again, creating different number of layers. Finally, gold nanoparticles (AuNPs) conjugated PEDOT polymer was drop-coated on the modified electrode to both promote electron transfer and act as base material for further protein immobilization via ionic bonding. The materials utilized substantially enhanced electrochemical current response, indicating possible synergistic effects. Afterward, the modified electrodes were incubated with *Staphylococcal* Protein A and subsequently IgG antibodies. The results obtained indicate successful deposition of both Protein A and IgG antibodies on the fabricated electrodes, which deemed this fabrication method promising for creating label-free point-of-care diagnostic immunosensors.

Speaker: Mr Zunpitch Kwanyuen (Department of Biomedical Engineering, Chulalongkorn University)

8:00 AM Classification of arabica by electronic tongue

An electronic tongue (e-tongue) represents a class of machines that are able to classify liquid samples, e.g. food and beverages, usually from various electrochemical methodology in combination with pattern classification and recognition analyses. This research aims to classify Arabica coffee by using an in-house electrochemical based on cyclic voltammetry and principal component analysis (PCA). Arabica coffee samples include green coffee beans and roast coffee beans of different grades from Pahee, Chiang Rai province. The coffee beans were ground and brewed following the cup test methods. The solutions were then measured and classified by the e-tongue. The results show that the e-tongue classifies the differences of the coffee samples from the most significant to the least as follows: brewing methods, the degree of roast, and lastly the grade or the origin of coffee. The results will be compared with human sensory tests (total = 30). This research demonstrates the potential of the e-tongue as a rapid and low method for quality control of coffee.

Speaker: Mr Aant Phatthara-aneksin (College of Nanotechnology, King Mongkut’s Institute of Technology Ladkrabang, Bangkok 10520, Thailand)

8:00 AM Comments on holographic star and the dual QGP

We study static AdS star in generic dimension. The dependence of the mass limit to the bulk fermion mass is explored. In the bulk conformal limit, the mass limit saturates at a value identical to the mass limit of a radiation star or the AdS space filling with pure radiation. The temperature and entropy of the degenerate AdS star in the bulk conformal limit is zero in contrast to the radiation star. Holographically, the universal mass limit corresponds to the upper limit of the deconfinement temperature in the dual gauge picture. The QGP at this temperature is dual to the large black hole and the heat capacity is positive. When the fermion mass increases, the mass limit falls into the range of the small black holes. We found that even though the small black hole has negative heat capacity, the AdS box allows possibilities that it remains in thermal equilibrium with the radiation as long as the size of the black hole is not smaller than a critical size. Consequently, the dual QGP with negative heat capacity can be produced and remains stable thermodynamically at temperature below a saturation temperature $T_{2}$. The QGP with negative heat capacity produced at higher temperature will still condensate completely into a gas of confined hadron.

Speaker: Dr Piyabut Burikham (Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok 10330 , Thailand)

8:00 AM Comparisons of Students’ Responses Relating to Buoyancy Force Between Two Different Teaching Approaches

There is wide agreement among physics education researchers that practical work is of goal importance for teaching and learning and allows for the promotion of several education goals. However in Thailand, teaching and learning approach was focusing on lecturing rather than laboratory. The research aim to compare the gain of learning achieved using two different instructional approaches under controlled conditions. The comparison was made between two group (N=39 and N=36) of grade 10 at Rajaprachanugrough 28, Yasothon province. First group done the experiment before lecturing and second group done the lecture before experimenting. Analysis of students’ task and diagnostic test results will be presented.

Speaker: Mr Pawaret Intana (Department of physics, Faculty of Science, UbonRatchathani University, Thailand, 34190)

8:00 AM Creation of 3D information from 2D images

The objective of this study is to use the internal and external parameters of calibrated camera to correctly reconstruct 3D information from 2D images. Calibration of camera is necessary for applications that involve quantitative measurements such as dimensional measurements, depth from stereoscopy, or motion from images. The depth of a point can extract from 2D images by the method of triangulation. In this presentation, the method and principle of camera calibration and 3D reconstruction are discussed demonstrated. The technique offers an alternative solution for 3D creation from 2D images.

Speaker: Apiram TEERANAVAGUM (Department of Physics, Faculty of Science, Mahidol University, Bangkok, THAILAND 10400)

8:00 AM Crystal and electronic structures of $\rm Li_{2}Ti_{6}O_{13}$ for lithium-ion batteries

The valuable non-renewable resources such as petroleum and natural gas will gradually peter out in near future, therefore alternative sources of energy are becoming of increasing interest. Moreover, in order to store energy, rechargeable lithium batteries are of particular interest since they have a possibility for portability and together with a high conversion efficiency. Hexa-titanium oxide based materials, such as $\rm Na_{2}Ti_{6}O_{13}$, $\rm K_{2}Ti_{6}O_{13}$ or $\rm Li_{2}Ti_{6}O_{13}$, have been intensively investigated because of their potential applications as electrodes for ion-exchange batteries. By means of first-principles calculations, we study the electronic structure of $\rm Li_{2}Ti_{6}O_{13}$, which has been experimentally shown as one of possible materials for a cathode in lithium-ion batteries. We have obtained the crystal structure of $\rm Li_{2}Ti_{6}O_{13}$ and $\rm Ti_{6}O_{13}$, which $\rm Ti_{6}O_{13}$ was not completely determined experimentally. The overall lattice parameter are quite good agreement with experimental. Our calculated band gap of $\rm Li_{2}Ti_{6}O_{13}$ is 2.92 eV when a general gradient approximation (GGA) functional were used, while the experimental band gap is 3.5 eV. The electronic band dispersion reveals that the both electron and hole mobility are low. The capability to store energy can be expressed in term of intercalation voltage. Our computational average intercalation voltages are 2.08 Volt with GGA-PBE functional and 1.78 Volt with HSE Hybrid functional. Our calculation are found to be in excellent agreement with experiments of 1.70 Volt.

Speaker: Mr Klichchupong Dabsamut (Department of physics, Kasetsart University, Bangkok 10900, Thailand)

8:00 AM Designing an Inquiry-based Learning Approach about Force and Pressure to Enhance Elementary Students’ Critical Thinking Skills

The purposes of this one group pre-/post-test research were to design an inquiry-based learning approach about force and pressure based on the 80/80 efficiency criterion, and to enhance students’ critical thinking skills. The participants were 25 purposively selected grade five students from Ponduan School, Wang-Hin, Srisaket in the first semester of the 2014 academic year. The results indicated that the overall quality of the inquiry-based learning approach was at the highest level. The efficiency regarding the standardized criteria E1/E2 was 81.06/80.66. The participants were also asked to complete a critical thinking skills test and its results showed that the mean post-test score was significantly higher than the mean pre-test score at the statistical level of .05.

Speaker: Ms Pannaporn Duangkam (Department of physics, Faculty of Science, Ubon Ratchathani University, Thailand 34190)

Slides Pannaporn_SPC2015.docx Pannaporn_SPC2015.pdf

8:00 AM Developing Analysis Skills about electrical DC circuit by Virtual board on Ohm’s law

This study aimed to developing analysis Skills and solving a problem about electrical circuit. In the time, Learning of students to attend on examination of University. Teaching in mostly schools emphasized theory but knowledge in physics must study from learning by doing for foundation in future. In this research, the participants were attending students level as grade 12. There were 35 students one group. The first, experiment have used examination of multiple choices 12 articles about DC circuits which is developed by Paula V. Engelhardt and Robert J. Beichner North Carolina State University Department of Physics . The result was found that 88.57 percentage from 35 students through the target 60 percentage of full marks. And practical tests by learners used project board appear that 35 students through the target 60 percentage of full marks 0 percentage. Consequently the student must practice with virtual electronic board then test again. The pretest posttest group design was used in carrying out the study. The data of experiment were analyzed t-test and normalized gain. The result shows that statistically significant mean differences between the pre-test and post-test at significant level of .01 and average normalized gain was in medium gain (0.55). Thus this virtual board can be used efficiently as a learning tool for students to enlighten their understanding in DC circuit.

Speaker: Mr Panya Wichanphet (Department of physics, Faculty of Science, UbonRatchathani University, Thailand, 34190)

8:00 AM Developing concept of a frictional force by using predict-observe-explain (POE) technique

We have learned from our experience of teaching physics that students misunderstand about the concept of a frictional force. The objective of this work is to enhance the students’ understanding on the concept of a frictional force for grade 10 students of Chaiyaphumbhakdeechumphon school, Chaiyaphum province. The research tools consist of the teaching plan with predict-observe-explain (POE) technique, experiment sets, and conceptual tests on the frictional force. The data analysis of pretest and posttest using t-test and normalized gain will be disused.

Speaker: Mr Anek Hongthong (Department of physics, Faculty of Science, UbonRatchathani University, Thailand, 34190)

Poster Poster_SPC2015.pdf

8:00 AM Developing Scientific Concepts on Magnetic and Electric Field using Simple Experiment and Multimedia Learning

Science experiment plays an important role in developing scientific knowledge for learners in science. Effective teaching methods must emphasize learning by experimenting where students see real phenomena. Through low-­cost simple experiments designed for hands-­on activity in conjunction with the reinforcement of graphical multimedia, the students have enhanced the matching scientific concepts. This method helps to solve the lack of scientific equipments. The purpose of this research was to develop the students’ scientific concepts on magnetic and electric fields using science inquiry process by simple experiments in conjunction with multimedia learning. The pretest and posttest control group design was employed in carrying out the study. The research tools consisted of simple experiments and the multimedia learning, lesson plans based on the science inquiry process, the magnetic and electric fields concepts 2­-tiers test, think­-aloud interviews on the scientific conceptual test and student’s satisfaction test. The data were analyzed into the average percentage, standard deviation, t­-test and average normalized gain. The result of the target group shows statistically significant mean differences between the pre-­test and post­-test at significant level of .01. The class average normalized gain was in the medium gain (0.33). The students’ abilities to explain the concepts in levels of good, have positive comments, and have very satisfied about the learning process. This result indicated that science inquiry process by simple experiments and multimedia learning can be used to develop students’ conceptual understanding on magnetic and electric fields. The students had an opportunity to experience from actual practice to build up new body of knowledge by themselves, enhancing scientific concepts through the multimedia learning and therefore students have positive attitude for science learning process.

Speaker: Mr Kreangkrai Tanawesh (Department of physics, Faculty of Science, UbonRatchathani University, Thailand, 34190)

8:00 AM Developing STS Projectile Motion Unit for Providing Students’ perception of the relationship between Science Technology Engineering and Mathematics

STEM education suggested that students should be enhanced to learn science with integration between Science, Technology, Engineering and Mathematics. To help Thai students make sense of relationship between Science, Technology, Engineering and Mathematics, this paper presents learning activities of STS Projectile Motion Unit. The developing of STS Projectile Motion Unit is a part of research that aimed to enhance students’ perception of the relationship between Science Technology Engineering and Mathematics. This paper will discuss how to develop Projectile Motion Unit through STS approach in framework of Yuenyong (2006) where learning activities were provided based on 5 stages. These included (1) identification of social issues, (2) identification of potential solutions, (3) need for knowledge, (4) decision-making, and (5) socialization stage. The learning activities could be highlighted as following. First stage, we use movie of ‘Conan the barbarian (human catapult)’. Second stage, students will need to identification of potential solutions by Create Catapult Model. The need of scientific and other knowledge will be proposed for various alternative solutions. Third stage, students will gain their scientific knowledge through laboratory and simulation of projectile motion. Fourth stage, students have to make decision for the best solution of designing and creating catapult model based on their scientific knowledge and others (e.g. mathematics, economics, art, value, and so on). Finally, students will present and share their catapult model in society (e.g. social media or exhibition) in order to validate their ideas and redesigning.

Speaker: Mrs Prapatsorn Seattha (Department of Education in Science and Technology, Faculty of Education, Khon Kaen University, Thailand, 40002)

8:00 AM Development of $^{68}$Ga-peptide for Positron Emission Tomography Tracer

Bombesin peptide is crucial for the development of positron emission tomography (PET) tracer for human prostate cancer. The aim of this work is to optimize the labeling condition of Ga-68 with DOTA-[Pro$^1$,Tyr$^4$]-bombesin, an analog of bombesin peptide, through $\textit{in vitro}$ and $\textit{in vivo}$ studies. It was found that the radiolabeled product $^{68}$Ga-DOTA-[Pro$^1$,Tyr$^4$]-bombesin was obtained in high radiochemical purity, ≥98%, without further purification. The results of $\textit{in vitro}$ stability study of radiolabeled compound in phosphate buffered saline, ferric chloride solution and human serum showed that $^{68}$Ga-DOTA-[Pro$^1$,Tyr$^4$]-bombesin was stable for 2 hours. In vitro evaluation of radiolabeled peptide affinity to GRP receptors was performed by a competitive cell-binding assay in the human prostate cancer cell line PC-3 with $^{125}$I-[Tyr$^4$]-bombesin as radiolabel. The calculated IC$_{50}$ of $^{68}$Ga-DOTA-[Pro$^1$,Tyr$^4$]-bombesin with PC-3 cells using GraphPad Prism was in the range of 36-123 nM with the best IC$_5$$_0$ of 66 nM. The uptake of $^{68}$Ga-DOTA-[Pro$^1$,Tyr$^4$]-bombesin from biodistribution study in tumor-bearing nude mice was 3 times higher in tumor than in muscle tissue at 2h post injection.

Speaker: Ms Piriya Kaeopookum (Research and Development Division, Thailand Institute of Nuclear Technology (Public Organization), Nakhonnayok, THAILAND 26120)

8:00 AM Development of light detector for Michelson Interferometer experiment Instrument

We developed a supplement instrument for Michelson Interferometer experiment instrument. In this experiment, we have to count numbers of fringes to determine wavelength of He-Ne laser. Without this extra instrument, the counting is hard and easy to make error because the fringes are very small. This instrument serves as light counting device. It composes of light sensor, comparable circuit, microcontroller and LCD panel. This device is designed to count only high intensity light and specific wavelength (600-1,000 nm). When there is a constructive fringe pass the light sensor, this device will count the fringes. We found that using this device can improve experiment results compared to using only by eyes. We calculated the wavelength of He-Ne laser to be 669.2 nm which was only 0.18% error. This device is a part of interactive multimedia for advance physics lab. This research was supported by Rajamangala University of Technology Thanyaburi Research Fund.

Speaker: Ms Chanoknan Banglieng (Division of Physics, Faculty of Science and Technology, Rajamangala University of Technology Thanyaburi, Pathum Thani 12110)

Paper Edit figure 2 flowchart SPC2015paper.pdf

8:00 AM Development of Portable Desk Lab for High School and University Physics

The senior project aimed to develop a series of experimental apparatus for use in teaching and learning physics in high school and university courses. Each apparatus is miniaturized to about a fifth of conventional one, built on a small steel plate of B5 size. Therefore, it is portable and can be placed on a classroom desk. Each set is constructed by a number of parts divided according to their functions, and some of them are interchangeably useable in other experiments. This saves material, cost, and space. The sets are flexible enough so that they can be modified for other purposes by the user according to his (or her) own idea. In the first phase of this study, the experiments relevant diffraction of light, this equipment evaluates the interference effect of light after passing through a narrow single slit, and refraction of light, this equipment shows the refraction of light phenomena by which a ray of light changes direction (bending effect of light) when it passes from one transparent material (an optical medium) into another of light was developed.

Speaker: Wachira Seesad (Department of Physics, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, THAILAND)

8:00 AM Development of weather station for wind direction, wind speed and temperature measurements

This work was aimed to study program for control an anemometer, wind vane, and thermometer sensor with dsPIC33 microcontroller. This prototype was developed for basic measuring, storing and monitoring weather data by personal computer. There are 3 parts of measurements. The first, wind direction was measured by wind vane. The structure of the sensor is a variable resistor. Voltage divider circuit was applied to the sensor. Second, wind speed was measured by anemometer. The structure of the sensor is cylindrical spindle. Frequency signals sent from it was detected by capture command on microcontroller. Wind direction and wind speed were calibrated by wind simulation and compared with standard tools. The last, temperature was detected by digital DS18B20 thermometer sensor. It interfaced a 1-wire bus to communicate one port pin of microcontroller. Serial data signals are communicated between the personal computer and the sensor. In this research, the authors have successfully demonstrated a prototype and monitored weather at Ubon Ratchathani University station. It was able to convert these signals to acceptable values.

Speaker: Mr Warut Singseeta (Department of Physics, Faculty of Science, Ubon Ratchatani University, Warinchamrab, Ubon Ratchatani, 34190, Thailand)

8:00 AM Effect of water vapour on neutron detection of cosmic rays

Cosmic rays play an important role in our daily lives and can be used in various fields of educational research, especially in physics and astrophysics. However, the detection of cosmic rays is affected by many factors, and atmospheric water vapour pressure was recently suspected to be an important factor. Princess Sirindhorn Neutron Monitor (PSNM) is a cosmic ray detector in Chiangmai, and the count rate of nearby bare counters relative to PSNM showed a strong anti-correlation with atmospheric water vapour pressure data. It is not clear whether this anti-correlation is a direct effect of water vapour or an indirect effect due to water accumulation on concrete around PSNM. Such an anti-correlation was, therefore, searched with the count rate from a bare neutron counter (MicroMonitor) at Mahidol University in Bangkok. MicroMonitor is in a building; the indirect effect should not be found, but a direct effect would be. Raw count rate and atmospheric pressure data from several years of MicroMonitor operation were processed, normalised with the pressure-corrected PSNM count rate and searched for a correlation with atmospheric water vapour pressure data at Bangkok. The results were compared with those for PSNM. The neutron detection data at Mahidol University were found that they fluctuate much less and do not exhibit a direct effect of atmospheric water vapour. Consequently, it was concluded that the neutrons detected by bare counters can be indirectly affected by atmospheric water vapour as a proxy for accumulated water which absorbs low energy neutrons.

Speakers: Mr Kritpong Kulthamrongsri (Department of Physics, Mahidol Wittayanusorn School, Nakhon Pathom, 73170, Thailand), Mr Supawit Kittipadakul (Department of Physics, Mahidol Wittayanusorn School, Nakhon Pathom, 73170, Thailand), Mr Wattanapol Sangpho (Department of Physics, Mahidol Wittayanusorn School, Nakhon Pathom, 73170, Thailand)

Poster Poster.pdf

8:00 AM Electrical sex reversal of Nile tilapia from prototypes toward commercial product

The present project has been extended from our previous lab-scale work of sex reversal for monosex-male Nile tilapia by using a transient pulse-electric field induction toward commercial products. All male sex reversal rate from 89.25% to 92.5% is achieved. Our newly equipment (to be patented) of electrical sex reversal was developed for large-scale of more than 10,000 eggs for each induction. This version of the equipment is designed for commercial propose (> 1 million induced eggs/day) without distortions of the signal (less than 5% error). In this work we demonstrated the boundary conditions of reversible and irreversible electropermeabilised eggs (critical values) (when they perform in temperature between 20-35 $^{\circ}$C) suspended in electrical sex reversal mediums (to be patented through NSTDA) to optimize survival rate and hatching of the induced fry. This work we also clarified the most suitable stage of egg development (day post fertilization: dpf) to be selected for the best electrical sex reversal process. We found that all stages during (a) zygote$-$1 dpf (b) cleavage$-$1 dpf (c) blastula$-$1 dpf (d) segmentation$-$2 dpf and (e) pharyngula$-$3 dpf before hatching$-$5 dpf could be employed for electrical sex reversal but pharyngula was the optimized phase. Long-term monitoring of the stable-sex reversal of all induced fry had been verified in order to test for 4-6 months old fish of table size, 6-9 months old and 9-12 months old (parent breeding stocks). Study of hormone delivery through the permeabilised membrane including hormone remaining in the electrical sex reversal medium for reuse propose of commercial product. Details of the sex reversal process including our equipment cannot be revealed since they are being in the patent process.

Speaker: Sakshin Bunthawin (Biotechnology of Electromechanics Research Unit, Science of Physics, Faculty of Technology and Environment, Prince of Songkla University, Kathu, Phuket 83120, Thailand)

8:00 AM Electronic and dynamical properties of YH$_{\textrm{x}}$ (2.83 < x $\leq$ 3.00)

According to thin film experiments, the electronic property of yttrium-hydride (YHx) system changes as a function of hydrogen concentration. The transformation of yttrium dihydride (YH${}_2$) into yttrium trihydride (YH${}_3$) structure by hydrogenation causes its resistivity to increase rapidly, and is constant after the YH${}_{2.85}$ is formed. We used *ab-initio* calculations to study the electronic and dynamical properties of YH${}_x$ hcp phase, where 2.83 < $x \leq$ 3.00, by removing hydrogen atoms at different sites. Results show metal-to-semiconductor transition with increasing hydrogen content, consistent to the experiment.

Speaker: Mr Anuphong Thongted (Department of Physics, Faculty of Science, Chulalongkorn University, THAILAND 10330)

8:00 AM Electronic band structure of Hydrazine-water doped Single-Walled Carbon Nanotubes as n-Type Semiconductor

We have studied the electronic band structure of single-walled carbon nanotubes (SWCNTs), (8,0) 3 primitive cells 96 carbon (C) atoms doped with hydrazine (N${}_2$H${}_4$) and water (H${}_2$O). Van der Waals corrected density functional theory calculations using plane wave approach with periodic boundary conditions were carried out for the adsorption of the intermolecular interaction. The results indicate that hydrazine physisorbs to the surface of SWCNTs and carbon atoms still retains the formal sp2 hybridization. Furthermore, the electronic structures and Bader charge analysis of the considered complex reveal the band gap of intrinsic semiconductor changed from 0.6 to 0.4 eV, as n-type semiconductor. The configuration of hydrazine and water, hydrogen bonding network supported, are important key to occur donor state in physisorption doping process.

Speaker: Wutthisak Prachamon (School of Physics, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand)

8:00 AM Electronic Tongue as an Alternative Tool for Classifying Oil-Based Products

Current electronic noses have limitations in olfaction of oil-based compounds, owing to their low responses for metal oxide gas sensors. This research is aimed to develop an alternative method to classify oil-based products, including fragrance, by using derivatizing agent to derivatize oil-based compounds followed by measurements with an in-house electrochemical electronic tongue (e-tongue). The electronic tongue has been designed and constructed based on the pattern classification of cyclic voltammograms. Cooking oil and oil-based fragrance samples were mixed with an aqueous solution of citric acid and characterized by e-tongue. The electronic tongues were also compared to measurements by an electronic nose based on metal oxide gas sensors. Preliminary results indicates that the e-tongue in combination with the derivatization method is able to classify the oil-based compounds in terms of type and quantity, outperforming the e-nose.

Speaker: Mr Vittachai YUWAPHAN (College of Nanotechnology, King Mongkut’s Institute of Technology Ladkrabang, 10520, Thailand)

8:00 AM Enhancement of oil Palm (Elaeis guineensis Jacq.) by Magnetically treated Water

Oil palm planting has become a very important agriculture especially in Southern Thailand. Because its oil production has been used as human consumption and is now developed as bio-energy used for some vehicles therefore oil palm has become a very important economical plant which has been promoted to crop widely. However, since a nursing time of young oil palm trees needs more than 2 years, rare of young oil palm trees which caused high price has still caused a problem to agriculturist. In addition, some young trees weak and unable to grow. This work we therefore present physics method to enhance oil palm seedling. Magnetically treated water (MTW) was applied to young oil palm nursery. Oil palm seedlings which were electromagnetically germinated were divided into two groups and transferred into soil pot with same basic nutrition. Both groups were planted at nature environments. Light intensity at 1200 Lux was controlled. The first group was watered every day by MTW whereas the second group was applied by normal water and act as control. Sprout Heights of both groups were daily recorded. We found that oil palm seedlings which were watered by MTW grew 3 times faster than control with a growing rate of 0.31 cm/day. Larger and longer leafs than those of control also were observed. Our results conclude that MTW is able to stimulate plants growth and reduce their nursing time.

Speaker: Sasitorn Uaysin (Faculty of Science and Industrial Technology, Prince of Songkla University, Surat thani Campus, Surat thanni, 84100, Thailand)

8:00 AM First principles calculations of cation-ordering effects on electronic band structure of ZnSnN2 and ZnGeN2

The Zn(Ge,Sn)N$_2$ semiconductors are closely related to the (Al,Ga,In)N. Both families have band gaps that span the ultraviolet through the visible range. Attention in the II-IV-N$_2$ has grown recently, with success in synthesizing ZnSnN$_2$ reported in 2012 [1] and the recognition of some of their unique optoelectronic properties and the potential that provide for designing novel and useful optoelectronic devices [2, 3]. It is also of great interest that several members of the II-IV-N$_2$ family are made from earth-abandant and nontoxic elements. We investigate lattice ordering phenomena for Zn(Ge,Sn)N$_2$ that are based on the wurtzite lattice, under the constraint that the octet rule be preserved. First-principles calculations of the energies of formation show that the differences in the energies of formation between Pna2$_1$ and Pmc2$_1$ crystal structures are 13±3 meV/fu (formula unit) for ZnSnN$_2$ and an order of magnitude larger for ZnGeN$_2$, and that for both materials the Pm31 structure, which contains only octet-rule-violating tetrahedra, has a significantly higher energy of formation and a signficantly lower band gap. The octet-rule-preserving model predicts a band gap that for ZnSnN$_2$ is relatively insensitive to cation-ordering. The violations of the octet rule lead to significant narrowing of the band gap. The observation that ZnGeN$_2$ orders in the Pna2$_1$ structure is consistent with the larger difference in the energies of formation of the Pna2$_1$ and Pmc2$_1$ structures in this case. The cation-ordering effects presented here has important implications for the optical, electronic and lattice properties of all wurtzite-based heterovalent ternaries. 1. N. Feldberg, B. Keen, J.D. Aldous, D.O. Scanlon, P.A. Stampe, R.J. Kennedy, R.J. Reeves, T.D. Veal, S.M. Durbin, Proc. 2012 IEEE Photovoltaics Specialists Conference, 002524 (2011). 2. Walter R.L. Lambrecht and Atchara Punya, III-nitride Semiconductors and their Modern Devices (Oxford University Press), chapt. 15 (2013). 3. Lu Han, Kathleen Kash and Hongping Zhao, Proc. of SPIE. 9003, 90030W-1 (2014).

Speaker: Dr Atchara Punya (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, THAILAND 50200)

8:00 AM Ga acceptors in SnO$_2$ revisited: A hybrid functional study

SnO$_2$ is an oxide semiconductor with wide band gap, good transparency, and high thermal and chemical resistances. As-grown SnO$_2$ usually exhibits $\textit{n}$-type conductivity with high carrier concentrations, which is an obstacle to make it $\textit{p}$-type. Consequently, applications of SnO$_2$ for optoelectronics are limited. Group-III elements, such as Al, Ga, and In, are candidates to give $\textit{p}$-type conductivity when substituting for Sn in SnO$_2$. Earlier calculations suggested that the calculated results of these dopants can be shallow or deep depending on the computational details, i.e., the result based on HSE calculations [Phys. Rev. B $\textbf{79}$, 245206 (2009)] showed that they are shallow acceptors, on the other hand, PBE0 calculations [J. Mater. Chem. $\textbf{22}$, 25236 (2012)] showed that they are all deep. In this work, the possibility of making $\textit{p}$-type SnO$_2$ by Ga was revisited using the HSE functional. Our results show that the acceptor level of Ga$_\mathrm{Sn}$ is actually deep. Therefore, Ga can only serve as compensating acceptor but not a $\textit{p}$-type dopant for SnO$_2$. This conclusion does not change even after the alloying of SnO$_2$ with Si (Si$_x$Sn$_{1-x}$O$_2$ where $x \sim$ 0.17) to introduce a compressive strain.

Speaker: Mr Nirawith Palakawong (School of Physics and NANOTEC-SUT Center of Excellence on Advanced Functional Nanomaterials, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand; Thailand Center of Excellence in Physics, Commission on Higher Education, Bangkok 10400, Thailand)

8:00 AM Health Determinations of Yeast Suspensions for Brewery Industry using Cell Velocity Spectrum

Living yeast cells in the brewery industry are active cells. They have different responses to AC electric field if they possess different dielectric properties. Electrical parameters which are used to determine health of yeast cells are the conductivities of the cytoplasm ($\sigma_c$), the cell membrane ($\sigma_m$), dielectric constant of the membrane ($\varepsilon_m$) and the cytoplasm ($\varepsilon_c$), respectively. These parameters affect cell translational speeds of positive dielectrophoresis. We measured yeast velocities during their moving towards the electrode tips, under various AC field frequencies. Lower critical frequency (LF), where yeast cells were repelled (i.e. negative force) from the tip after being attracted, was recorded against the conductivity of cell suspension medium ($\sigma_s$). It was observed that as the $\sigma_s$ was increased the LF was shifted towards a higher frequency value. Yeast velocity spectra were reduced significantly under greater $\sigma_s$ value. When the increased $\sigma_s$ reached a critical value the attractive force became negligible, implying equivalence to the cytoplasmic conductivity. Our experiments showed that yeast cells of 1.15 $\times$ 10$^5$ cell.ml${}^{-1}$ displayed the initial positive dielectrophoresis at LF of 60-80 kHz, when using $\sigma_s$ of 6 $\mu$S.m$^{-1}$. The velocity spectrum of yeast suspensions were affected by $\sigma_s$ of which the cells were suspending during the experimentation. An abrupt change in the velocity pattern explained dielectric properties of cell membrane and cytoplasm of yeast cells which reflect their health. By curve-fitting method, we achieved to determine health of yeast suspensions through the cytoplasmic and the membrane conductivity values.

Speaker: Sakshin Bunthawin (Biotechnology of Electromechanics Research Unit, Science of Physics, Faculty of Technology and Environment, Prince of Songkla University, Kathu, Phuket 83120, Thailand)

8:00 AM High pressure properties of doped ZnO from ab initio calculation

We performed ab initio calculation based on density functional theory for studying high-pressure properties of doped ZnO. At the beginning, the impurities of Al and Ga atoms into ZnO were investigated up to 10 GPa. The tendency of enthalpy formation under pressure was studied. The high-pressure properties such as lattice parameter, electron density and elastic constant were investigated. It was found that the enthalpy formation of doped ZnO decreases when pressure increasing. The chemical bonds and electron density differences of ZnO unit cells were changed by adding the Al and Ga atoms.

Speaker: Dr Prayoonsak Pluengphon (Division of Physical Science, Faculty of Science and Technology, Huachiew Chalermprakiet University, Samutprakarn 10540, Thailand)

8:00 AM High pressure properties of I-III-VI$_2$ compounds from ab initio calculation

Ab initio calculation based on density functional theory were performed for studying high-pressure phases and electronic properties of I-III-VI$_2$ compounds. Thermodynamic properties of a solid system were calculated by using LDA and PBE functionals. Stability of high pressure structures of I-III-VI$_2$ compounds were determined by comparing the lowest enthalpies. The high-pressure properties such as lattice parameter, electron density and elastic constant were investigated up to 200 GPa. Stability of high pressure structures were observed by studying the phonon dispersion relation.

Speaker: Mrs Sukanya Petchsirivej (Division of Physical Science, Faculty of Science and Technology, Huachiew Chalermprakiet University, Samutprakarn 10540, Thailand)

8:00 AM Investigation of Students’ Moral Reasoning in Learning Physics Laboratory

This study aimed to investigate moral reasoning of the first year students in physics laboratory. An instrument used in this study was 10 open-end questions. Each question corresponded to different aspects of moral reasoning such as integrity, diligence, discipline etc. The questions were given to 10 experience physics teachers and 100 first-year engineering students taking physics laboratory. Students took twenty minutes to finish the questionnaire. Teachers and students responses were rated into three levels including high, medium and low level of moral reasoning. As a result, students had lower level of model reasoning when compared with teachers. Most student responses were rated to be at medium to low level on questions about integrity, discipline, harmony and morality.

Speaker: Pornrat Wattanakasiwich (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai, 50200, Thailand; Physics Education Research Laboratory, Faculty of Science, Chiang Mai University, Chiang Mai, 50200, Thailand)

8:00 AM IR spectroscopy of O-related defects in CdSe

Detailed infrared (IR) absorption spectroscopy of O$_2$-related defects in zincblend-CdTe and wurtzite-CdSe were reported by Lavrov *et al* [Phys. Rev. B **84**, 233201 (2011), AIP conf. Proc. **1583**, 169 (2014)]. They clearly showed based on their experimental work that the IR absorption bands at 1096.8 and 1108.4 cm$^{-1}$ in CdTe samples are associated with the vibrational modes of SO$_2$-related defects in CdTe. In wurtzite-CdSe, due to the reduction in the symmetry (in comparison to the zincblende structure), there are three absorption peaks at 1094.2, 1107.5, and 1126.3 cm$^{-1}$ related to the SO$_2$ defects, instead of two. T-Thienprasert *et al* [J. Appl. Phys. **115**, 203511 (2014)] recently showed that SO$_2$ in CdTe can form a complex defect with Cd vacancy becoming SO$_2$-V$_\mathrm{Cd}$ complex defects with the vibrational frequencies in good agreement with the values observed by Lavrov *et al*. In this work, we employed first-principles calculations to study the SO$_2$-related defects in wurtzite-CdSe. Their formation energies were calculated and used to analyze the stable ones. The vibrational frequency associated with each defect were calculated via the frozen-phonon approximation and used to compare with the observed values. In wurtzite-CdSe, We found that the SO$_2$ defects can bind with V$_\mathrm{Cd}$ becoming SO$_2$-V$_\mathrm{Cd}$ complex defects similar to the case of SO$_2$ in CdTe. However, due to the lower symmetry of wurtzite structure, there are many possible orientations of SO$_2$-V$_\mathrm{Cd}$ complex defects, which will be presented along with their formation energies as well as calculated vibrational frequencies.

Speaker: Ms Pimpika Pimsorn (School of Physics and NANOTEC-SUT Center of Excellence on Advanced Functional Nanomaterials, Suranaree University of Technology, 111 University Avenue, Muang District, Nakhon Ratchasima, 30000 Thailand; Synchrotron Light Research Institute, 111 University Avenue, Muang District, Nakhon Ratchasima, 30000 Thailand; Thailand Center of Excellence in Physics (ThEP Center), Commission on Higher Education, Bangkok 10400, Thailand)

8:00 AM Mathematical Analyze of Breakdown Transmembrane Potentials of Fish Eggs using Hen-egg model

The present study proposes another alternative approach to model the geometry of Nile tilapia egg for evaluation of the induced transmembrane potential. The actual shape of tilapia egg is an asymmetrical prolate spheroid with a short prolate spheroid bottom and a more elongate prolate spheroid at the top with a common equator rather than a symmetrical prolate spheroid. Unfortunately, the precise model of such non-spherical bioparticle does not exist as yet. In the past, the closest available model was as a shelled symmetrical prolate-spheroid which gave the large error to calculate transmembrane potential. This work proposes the complete “hen-egg model” to analyze the implicit value of electrical breakdown transmembrane potential. The two semi-minor axes ($b$, $c$) are set to equal one another. The ratio between the semi-major ($a$) and semi-minor axes is 1.3. We keep the volume of the egg constant throughout our analysis which is equivalent to that of the “hen-egg model” possessing the effective values of the semi-major $a'$ and the semi-minor $b'$ axes so that the polarization of the egg can be assumed to be the same over the whole egg volume. In the case of the egg possessing a single dielectric shell, it was also analyzed as the equivalent tri-phases of RC-circuit using three pairs of resistors and capacitors to represent the conductive and capacitive properties of the egg’s shell, the inner part of the egg and the suspending medium, respectively. The complex specific impedances of each compartment of the fish egg were finally analyzed. The threshold transmembrane potential for electroporation of tilapia’s egg is evaluated. This approach can not only be applied to the spheroid model but also to model of the ellipsoid, oblate-spheroid and spherical shaped object by changing the appropriate value of the depolarization factor depending on the 3-D egg geometry.

Speaker: Sakshin Bunthawin (Biotechnology of Electromechanics Research Unit, Science of Physics, Faculty of Technology and Environment, Prince of Songkla University, Kathu, Phuket 83120, Thailand)

8:00 AM Micron-size Electrodes Fabrication for Capacitively Coupled Contactless Conductivity Detection (C$^4$D)

Capacitively Coupled Contactless Conductivity Detection (C$^4$D) is the detection technique used to detect both charged and non-charged particles in solution when performing electrophoretic separation in microfluidic devices. With the C$^4$D electrodes not directly exposed to solution, contamination of detecting specimen can be avoided. In this work, the new planar micro-size C$^4$D electrodes on a glass slide fabrication technique based on Printed Circuit Board (PCB) patterning was developed to be used with microfluidic device. The negative dry film photoresist used was Dupont Riston FX-515 with the thickness of 15 microns. The opening area size in the photoresist film down to 50 microns was achieved using 15 second exposure of 400 nm – wavelength light source, and 30 seconds development time in 0.85% Na$_2$CO$_3$ solution. The patterned glass slide was deposited with approximately 20 nm-thick gold thin film using sputtering technique to create the gold C$^4$D electrodes.

Speaker: Ms Jongrak Sanglao (Department of Physics and Materials Science, Faculty of science,Chiang Mai University, Chiang Mai, 50200, Thailand)

8:00 AM Pre-Service Physics Teachers Expectations in Learning Physics

The purpose of this study is to explore the learning expectation of 127 pre-service physics teachers from faculty of education, Thaksin University. The assessment instrument is a 34-item Likert-scale of the Maryland Physics Expectations (MPEX) survey, which consists of 6 clusters namely independence, coherent, content, reality link, math link and effort. Students ‘responses to the survey were rated the agreement as either favorable or unfavorable with the experts points of view. Results showed that students’ expectations of reality link cluster is the most similar ideas to the experts. In contrast, the most different expectations between students and experts was in the content cluster.

Speaker: Dr Singha Prasitpong (Faculty of Education, Thaksin University, 140 Kanchanawanit Rd., Meuang Songkhla District, Songkhla 90000)

8:00 AM Preliminary Investigation of Heat Transfer and Thermal Distribution in Computer Mainboard based on Finite Element Analysis

A Higher operating temperature increases a risk of mainboard in computer malfunction. In this work, the heat transfer and thermal distribution on a mainboard were investigated based on finite element analysis. We proposed boundary conditions and parameters at least to be defined. The results of simulation were compared with the actual results measured by the thermal imager. The comparison shows reasonably good agreement between both results. One of the impacts from this study is a methodology applying to set a practice for student learning.

Speakers: Mr Ittiwat Meesap (Undergraduate student in Manufacturing System Engineering Program, College of Data Storage Innovation King Mongkut’s Institute of Technology Ladkrabang, Bangkok, Thailand, 10520), Mr Tossapol Rattanapongwisut (Undergraduate student in Manufacturing System Engineering Program, College of Data Storage Innovation King Mongkut’s Institute of Technology Ladkrabang, Bangkok, Thailand, 10520)

8:00 AM Pulse-Electric Fields Inductions for Preliminary Sex Reversal of Blue-Spotted Coral Trout

The present study proposes an alternative technique of monosex-male reversal for the commercially important marine fish, blue-spotted coral trout ($\textit{Plectropomus leopardus}$), using transient square pulse-electric and androgen hormone dose. The egg of $\textit{P.leopardus}$ had a simple spherical shape ($ \approx 0.8 \pm 0.1$ mm) and its critical age of 6-19 hpf (hour post fertilization) were induced in the external field with 1-8 square wave pulses of 5-50 $\mu$s duration and amplitude of 350-500 VDC (equivalent to 87.5-125.0 kV.m$^{-1}$). The suspending medium of electroporation (EPM) contained PBS buffered (1M mannitol added to make the EPM medium isotonic to seawater, pH 7.5 adjusted with NaOH) with the minimized concentration of the androgen hormone 17$\alpha$-methyltestosterone (MT). These electrical parameters affect sex reversal rate. The optimized values are 400 VDC, 5 square-wave pulses of 50 $\mu$s duration with the concentration of 1,500 $\mu$g.l$^{-1}$ MT. Nevertheless, we have not yet accurately determined the sex reversal rate since their sex will be stable only after they are 2-3 years old. This study only claims sex reversal of 18 months old fish with temporary all-male sex reversal rate at 76.45-82.51% (n=18), less than 27% egg death. The capacity of our equipment was acceptable at a commercial density ranging from 550-1,000 eggs/50ml for each induction. This novel technique could reduce the MT dose down to a minimized value with a rapid throughput of only quarter-hour per batch of eggs and using only 50 ml lots of hormone containing medium.

Speaker: Sakshin Bunthawin (Biotechnology of Electromechanics Research Unit, Science of Physics, Faculty of Technology and Environment, Prince of Songkla University, Kathu, Phuket 83120, Thailand)

8:00 AM Search for the Standard Model Higgs boson in ZZ* to 4μ decay channel with the CMS experiment at √s = 8 TeV

A search for standard model Higgs boson is performed by analyzing the data from proton-proton collision recorded by the CMS experiment at center-of-mass energy of 8 TeV. The data is saved in the form of ROOT files. In this project, the data already have been reconstructed, identified and isolated physics objects such as electrons, muons, photons, etc. Then various properties of these physics objects are studied for optimization of a typical analysis in accord with various decay modes. This project use ‘muons’ for studying the distribution of important physics parameters, e.g. transverse momentum, geometrical acceptance, relative isolation, invariant mass of four muons.

Speaker: Teerapat Payupol (Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok 10330 , Thailand)

8:00 AM Sequential Signal Generator for Yeast Separations

The multiple-parallel plate electrode equipped with a sequential signal generator (SSG) (to be patented) has been developed for on-site yeast separations in the brewery industry. Dead and living yeast cells were separated by using non-uniform sinusoidal electric fields. The SSG was developed from our previous lab-scale version to produce a sinusoidal phase to generate out-of-phase electric fields for on-site operation with ranging frequency of 1 kHz-1 MHz and the output voltage range of 1-30V${}_\mathrm{pp}$. The phase difference addressing on the opposite electrodes are fixed as $\pi$ radian and its phase sequence can automatically be altered and circulated within interval time of 30 seconds (changed by a step of 0.01-30 second). Experimental results showed that living yeast cells of the brewery company exposed in the electric field strength ranged from 14 to 143 kV.m$^{-1}$ exhibited positive dielectrophoresis (cells attach to the electrodes) at the lower critical frequencies between 81.00-89.00 kHz (the optimized frequency was 82.43 kHz) if the medium conductivity ($\sigma_s$) was between 0.01-0.30 S.m$^{-1}$. These electrical conditions imply that yeasts being translated to the tip of electrodes were living cells. Percent yield of positive dielectrophoresis can be employed to evaluate the number either living or dead cells quantitatively. Moreover, the value of the lower critical frequency was shifted towards greater values when $\sigma_s$ was increased. The spectra of both positive dielectrophoresis of the living and dead cells were different resulting in difference of cells dielectric properties i.e. the conductivity of the yeast cytoplasm ($\sigma_c$) of the dead cell was less than that of the living yeast cells (typically, the living cell has a cytoplasmic conductivity of about 0.2 S.m$^{-1}$).

Speaker: Sakshin Bunthawin (Biotechnology of Electromechanics Research Unit, Science of Physics, Faculty of Technology and Environment, Prince of Songkla University, Kathu, Phuket 83120, Thailand)

8:00 AM Simple Thick Lens Made of a Bottle Filled with Liquid

This study aimed to calculate and to determine experimentally a focal length of a simple thick lens. The thick lens made of a round-bottom bottle (flask) completely filled with transparent liquid (such as water or oil). Four different sizes of a round-bottom flask including 100, 250, 500 ml and 1000 ml were used to change the diameter of thick lens. The focal length of thick lens was calculated using ray transfer matrices and substituting values of bottle thickness, outer radius, inner radius and refractive index of the filled liquid. The calculated value of focal length was then compared with the measured value from setting up a simple experiment. This simple thick lens can be used to demonstrate basic to advanced concepts of geometrical optics.

Speaker: Kittipoom Mala (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai, 50200, Thailand; Physics Education Research Laboratory, Faculty of Science, Chiang Mai University, Chiang Mai, 50200, Thailand)

8:00 AM Simulation and Experimental Study of Vibration Characteristics of Thai Traditional Brass Gong

In this study, the vibration characteristics of Thai traditional brass gong were numerically investigated based on finite element method (FEM) in three dimensions. We presented a methodology, boundary conditions and other parameters, which are important to be set. Preliminary results of simulation show set of natural frequencies and the corresponding mode shapes that were compared with the experimental results. It was found that both results are in good agreement. The most useful impact of this study is a simplified model in laboratory for helping to understand concept of physics and mechanical vibration.

Speaker: Ms Thitinan Chantramontol (Manufacturing System Engineering Program, College of Data Storage Innovation, King Mongkut’s Institute of Technology Ladkrabang, Bangkok, Thailand, 10520)

8:00 AM Smartphone in teaching Physics

This paper aimed to review literatures about how mobile phone is implemented in teaching physics from more than twenties papers in journals with a section on physics teaching such as Physics Education, European Journal of Physics, The Physics Teacher, American Journal of Physics, etc. In the past few years, technology of smart mobile phones has changed the way we lives and also are going to change the way we, as physics educators, teach. In this paper, a use of the smartphone for teaching physics was divided into five categories, according to applications (Apps). Firstly, the applications are used as a voting system. Secondly, the applications worked with built in sensors are for using as data collection instruments. Thirdly, the applications are for viewing teaching videos. Fourthly, the applications are used as a way for an instructor to communicate with students outside of the classroom. Fifthly, the applications with interactive simulation are used for students to learn from physics simulations or games. Examples of each category are given and discussed their possible implications for teaching physics.

Speakers: Ms Pokonwong Suthichon (Department of Physics and Material Science, Faculty of Science, Chiang Mai University, Chiang Mai, 50200, Thailand), Pornrat Wattanakasiwich (Department of Physics and Material Science, Faculty of Science, Chiang Mai University, Chiang Mai, 50200, Thailand)

Poster SPC2015-poster-Suthichon2.pdf

8:00 AM Sound absorption of oil palm trunks

Thailand was listed as the third in palm oil production in the world with the plantation area of about 5600 km$^2$ as in 2010. The plantation area is increasing due to the demand for the oil. As a result, there is plenty palm biomass leftover after each replanting process of oil palm trees. Biomass from each part of oil palm tree has been investigated for various applications such as particleboard and compressed wood panels. In this work, we explore the possibility of using oil palm biomass as sound absorbing application using a standing wave tube for the frequency range of 300-2000 Hz. The biomass used in this work is oil palm trunk. Two different cutting directions, parallel and normal to the fibrous grain of the palm trunk, are considered. The processed biomass has the thickness and diameter of 12.5 and 114 mm, respectively. A biomass disk is then inserted into the standing wave tube at different distances away—0, 2, 4 and 6 mm—from the backing metal plate for the determination of the sound absorption coefficients. In addition, the disk is drilled for 3-mm diameter through holes of which are organized in periodic fashion with 10-mm separations. Our results show that the absorption coefficients for the cross-cut panel are slightly greater than those of the parallel-cut. This is possibly due to the panel porosity. The through-hole disk provides significant improvement particularly at frequency above 1000 Hz. Our work presents an alternative application for the oil palm biomass.

Speaker: Ms Asleena SALAEH (Acoustics Laboratory, School of Science, Walailak University, Nakhon Si Thammara, Thialand 80160)

8:00 AM Stability Diagram of a Serial Quantum Dot System

We present a new method to construct a stability diagram of a serial quantum dot system. The partition function and average charge numbers of the system were calculated by means of imaginary-time path integrals. Consequently, the stability diagram for the quantum dot system was obtained by projecting the average charge numbers of the system to the gate voltage-phase space. To verify the method, stability diagrams for the triple quantum dot systems were calculated. The diagrams allow the quadruple points and positions in which quantum cellular automata processes occur to be determined.

Speaker: Mr Angkhan Intanin (Department of Physics, Faculty of Science, Mahasarakham University, THAILAND 44150)

8:00 AM Structural phase transition of binary compounds of TlX (X = N, P, As) under high pressure : An $ab$ $initio$ Study

In this work, density functional theory (DFT) has been performed to investigate high-pressure phase transitions of TlX (X = N, P, As). Both standard GGA and LDA functionals with norm-conserving pseudopotential are used to compare each other in recent work which the calculation results are reported in form GGA (LDA). Based on the previous theoretical predictions, B3-to-B1 (B4-to-B1 for TlN) are reinvestigated initially, as well as the other candidates with crystal structure of *Cmcm*, *P4/mmm*, *Cmmm*, and B2-type structure are undertaken for comparing energetically to predict the high-pressure phases in these compounds. It reveals that TlN and TlP transform to B1 at 19 (16) and 28 (10) GPa, by compressing B4 and B3, respectively. The reduction volumes are approximately 14.8 (15.2) % and 14.7 (16.4) % for TlN and TlP, respectively. Moreover, B2-type is predicted at 340 (395) GPa for TlN, and at 97.5 (81) GPa for TlP with passing through *P4/mmm*. In TlAs, B3-type structure does not undergoes to B1-type. But it could possibly transform to *Cmcm* and *Cmmm* structure at which is different with previous predictions.

Speaker: Kittipong Limchuchua (Mahidol Wittayanusorn School, Nakhon Pathom 73170, Thailand)

8:00 AM Study of $\textit{Butea superba}$. Roxb Root (Red Kwao Krua) Extract on Sex Reversal of Nile Tilapia by using Exponential Decay Pulse-Electric Fields

The present study employs exponential decay pulse-electric field inductions to enhance sex reversal of Nile tilapia eggs in suspensions for monosex-male. The novel technique was the pilot study to initiate the usage of natural androgen hormone of $\textit{Butea superba}$ (Red Kwao Krua) extract instead of our previous electroporation medium of 17$\alpha$ - methyltestosterone (MT). The eggs of Nile tilapia obtained from our parent breeding stocks were carefully selected for inducement in pulse electric field strengths of 0.25- 87.50 kV.m$^{-1}$ generated between narrow plate electrodes. Electric fields of 3-5 exponential decay pulses of 5-100 $\mu$s durations were applied to optimize egg’s electroporation. The prototype of the electrode equipped with the sequential signal pulse-generator (SPG) for on-site inductions was fabricated which could induce $\approx$ 50 eggs/SPG unit at one time. The electroporation medium (EPM) was prepared using HEPES buffer with a minimized concentration of the androgen hormone, $\textit{Butea superba}$. Roxb Root (Red Kwao Krua, RKK) extract. Only minimal volumes (50 ml) of buffered MT medium were required. The electroporation of induced membrane pores were observed by determination of pore sizes and pore densities through SEM micrographs. After the process of sex reversal, induced eggs were grown up to frysizes big enough (2 months old) to verify sex reversal. This novel technique reduced the RKK dose down to a minimized value of 1,500 $\mu$g.l$^{-1}$ and achieved a 69.14% male: female sex ratio.

Speaker: Sakshin Bunthawin (Biotechnology of Electromechanics Research Unit, Science of Physics, Faculty of Technology and Environment, Prince of Songkla University, Kathu, Phuket 83120, Thailand)

8:00 AM Surveying of high-school students’ ability in drawing free-body diagrams

There are various strategies for solving physics problems in mechanics. Each strategy contains particular steps that are appropriate for particular topics in mechanics. One of the most important steps in almost all strategies is drawing a free-body diagram (FBD). It is an essential skill students must have in order to solve physics problems successfully. In this study, we conducted a survey of high-school students’ ability in drawing FBD. A set of questions was given to a group of grade-12 students from various schools who have already learned how to draw FBD. They were asked to draw all vectors of forces acting on an object in different situations, including a stationary object placed on another stationary or moving object or on an inclined plane as well as an object moving with constant velocity or acceleration. We found from the survey that most of the students could not draw all the FBD correctly. It was quite a surprise that they had difficulties in drawing a correct direction of an object’s weight as well as “normal” forces due to other objects. We will show in the presentation students’ skill in drawing FBD as well as their alternative understanding of forces acting on an object. This research will be further used to develop instructional strategy for enhancing high-school students in such skill.

Speaker: Mr Rathaphol Yooyued (Department of Physics, Faculty of Science, Mahidol University, Bangkok, THAILAND 10400)

8:00 AM Surveying Physics Teaching Strategies in Three Leading Schools

To obvious how leading schools conduct their physics classrooms, this study has surveyed teaching strategies in physics classrooms of three leading schools (Mahidol Wittaynusorn, Triamudom Suksa, and Suankularb Wittayalai) using a 2 page survey. The contents of the survey were separated into two parts. Part 1 includes questions asking students to provide their personal information such as gender, age, grade, and favorite subjects. Part 2 includes a question that asking students to select activities which frequently happened in their physics classrooms from a list. The survey was distributed randomly to high-school students in those three leading schools during the 1st and 2nd semesters in 2014 academic year. Students took approximately 10 minutes to complete the survey. After that, their responses were tallied to see the frequency. The activities showed more than fifty percent responses were concentrated as dominant characteristic of teaching strategies. The surveying results showed similarity of physics teaching strategies between Triamudom Suksa and Suankularb Wittayalai. The teaching strategies in both schools quite focused on providing information, exercise and examples of solving physics problems while the differences found in Mahidol Wittaynusorn. Besides providing information, exercise and examples of solving physics problems, physics teachers let their students do more experiment than the students of those two schools.

Speaker: Dr Umporn Wutchana (Department of curriculum and instruction, Faculty of Education, Ramkhamhaeng University, Bangkok, 10240, Thailand)

8:00 AM Surveying Students’ Conceptual Knowledge of Fluid Mechanics

Over the last 30 years, physics education research revealed that students already have a number of ideas about how physical systems behave, even before they start to study physics. In many cases, these ideas differ from accepted scientific ideas. Other research showed that it is difficult for students to change their initial ideas and found that traditional instruction is relatively ineffective in correcting these misconceptions or in helping students develop a more appropriate way of thinking. Users of the peer instruction technique discovered learning gains above the level of traditional pedagogies and consistent with interactive engagement. Thus, a low-cost experimental set incorporated with peer instruction about fluid mechanics was developed. Before implementation of this tool, students' conceptual knowledge was assessed by a 15 item two-tier test. The test was classified into four sub-topics, density, buoyant force, Archimedes' principle, and Bernoulli's principle. The mean scores before the implementation were 10.34, 39.41, 16.09 and 28.74 respectively.

Speaker: Mr Mana Chatmontree (Department of physics, Faculty of Science, UbonRatchathani University, Thailand, 34190)

8:00 AM Teaching strategies to facilitate students’ use of mathematics when solving physics problems

The complexity of physics has implications for the teaching of physics today. That physics is a very complex subject is shown from the research on problem solving and misconceptions that has dominated the field during the past 30 years. It is commonly known that students have difficulty for solving physics problems because of mathematic skill. In this study 120 high school physics students were given a set of pure math problems and a set of physics problems that require them to use the same mathematical processes. Presented here are the preliminary results that show a strong positive relationship between math and physics scores. We also introduce the teaching strategies that facilitate students' use of mathematics when solving physics problems.

Speaker: Mr Putcharapong Prawai (Department of physics, Faculty of Science, Ubon Ratchathani University, Thailand, 34190)

8:00 AM The Determination of the Area of Origin in Medium Velocity Blood Spatters: Numerical Methods Approach

In crime scene reconstruction, the patterns of bloodstains serve us opportunities to determine the location of bloods source which can be referred to the position of victim or weapon used. For medium velocity blood spatters, generally the victim is hit by a blunt object (such as a hammer or a baseball bat). The trajectories of blood drops are in projectile motions. In this work, the projectile motion of blood drops with the effect of air resistance was considered. The trajectories are recreated by solving the equation of projectile motion of projectile motion and using the numerical method, Runge-Khutta 4th order, in time reversal procedure. The area of origin could be obtained by creating the trajectories of all selected bloodstains. The numerical results give a good approximation to locate the area of origin of bloodstains with acceptable errors.

Speaker: Mr Chalermwat PINNOI (Department of Physics, Faculty of Science, Mahidol University, Bangkok, THAILAND 10400)

8:00 AM The Development of Concepts of Grade 11 Students on Resistor Circuit Through Predict-Observe-Explain (POE) Approach

This study was qualitative research aimed to improve conceptual understanding of grade 11 students on resistor circuit through Predict-Observe-Explain (POE) approach. There were 34 grade 11 students those studied in the second semester of academic year 2014 (November 2014 to March 2015) in Strisuksa School, the Secondary Educational Service Area 27, Roi-Et province, participated this study. There were two categories research tools had been used in this study. Firstly, Predict-Observe-Explain (POE) approach lesson plan. Secondly, a set of the evaluation tool, scientific concepts test, two-tier multiple choice diagnostic test. The collected pre-test data were analyzed for investigating students’ background knowledge to be used in lesson plan designing and the post-test was done soon after the POE finished. The findings revealed that student’ scientific concepts in prior intervention by POE approach in resistor circuit could be interpreted into various categories and the majority of them were diverged from scientific concepts about connecting light bulbs in series and parallel, connecting resistors in series and parallel. After learning through POE approach, it found that students’ concepts generally were according to scientific concepts. It could be concluded that the students understanding could be developed toward scientific concepts by using POE approach.

Speaker: Ms Yupaporn Jarearnkhat (Department of Education in Science and Technology, Faculty of Education, Khon Kaen University, Thailand, 40002)

Poster PosterSPC_Yupaporn_Jarearnkhat.pdf

8:00 AM The Development Of Scientific Concept of “Momentum And Regarding Collision” For Grade 10th Students Though Leaning Activities Based On The Predict-Observe-Explain (POE) Method

The purpose of this research was to develop scientific concepts of momentum and collision for grade 10th students though Predict-Observe-Explain (POE) leaning activities. There were 34 grade 10 students of Roi-Et Wittayalai School, during the second semester of academic year 2014 (November 2014 – March 2015) participated this study. There were two research tools were used in this study. Firstly, experimental tool that consisting of 6 POE lesson plans. Secondly, data collection tool consisting of multiple choice test for investigating students’ understanding of the scientific concept of momentum and collision which was used for examining the student both pre-test and post-test. The pre-test results performed that most of the students contained partial conceptual understanding while some students represented alternative concepts. In contrast, the post-test shown that the number of misconception students was decreased and most of them performed good science conceptual understanding.

Speaker: Ms Kanita Srithanee (Division of Science Education, Faculty of Education, Khon Kaen University, Khon Kaen 40002, Thailand)

kanitapaper_spc15.docx

kanitapaper_spc15.pdf

Poster Postter.pdf

8:00 AM The development of scientific concept on electrostatics of grade 11 student through Predict – Observe – Explain (POE)

This research was aimed to study and enhance the students’ concepts on electrostatics by using Predicts-Observe-Explain approached. There were 45 grade 11 students, second semester of academic year 2014 (November 2014-March 2015), Roi-Et Wittayalai School Office of Secondary Education Service Area 27, participated this study. This research was performed in qualitative research designed. There were two main research tools used. Firstly, 6 lesson plans (total 12 hours) on electrostatics. Secondly, evaluation tools, 20 questions with two-tier multiple choices. The response from both student and observer were interpreted soon after each learning activity finished. It was found that the pre-test of students showed their partial misconception for 37.20% of total students and 62.79% total misconception. After finished Predicts-Observe-Explain approached, post-test performed that student had perfectly the correct for 62.22% while 37.77% still remained some misconceptions on electrostatics. It could be concluded that students had developed their alternative concepts to scientific concepts on electrostatics.

Speaker: Ms Mateeya Martjun (Department of Education in Science and Technology, Faculty of Education, Khon Kaen University, Thailand, 40002)

Poster Mateeya_Martjun_Poster_SPC_2015_Board_26.pdf

8:00 AM The development of scientific concepts on motion in uniform field of grade 10 students through Predict-Observe-Explain (POE) with video demonstration.

This research was aimed to study and enhance the students’ concepts on motion in uniform field through Predict-Observe-Explain (POE) by using video demonstration. There were 29 grade 10 students, second semester of academic year 2014, Nareenukun School Office of Secondary Education Service Area 29. This research was performed in qualitative research designed. There were three main research tools used. Firstly, 6 lesson plans (total 12 hours) on motion in uniform field. Secondly, the evaluation tools consisting of a learning management’s journal and a teaching observation form. Finally, Force Concept Inventory Diagnostic Test by Eric Mazur (Pearson Prentice Hall, 1997), Thai version. The results shown that the students had alternative conceptions in the direction and magnitude of motion in uniform field and observing data was interpreted soon after each learning activity finished. It was found that students had developed their alternative concepts to scientific concepts after participarting the POE with video demonstrations.

Speaker: Mr Thoedsak Nachampa (Department of Education in Science and Technology, Faculty of Education, Khon Kaen University, Thailand, 40002)

Full paper.doc

Full paper.doc

Full paper.pdf

Full paper.pdf

Poster Poster.pdf

8:00 AM The development of scientific of concept on electric current of grade 11 students through Predict – Observe – Explain : Classroom – Based Action Research

This research aims to develop Predict – Observe – Explain (POE) approach learning activities and to develop scientific concepts in Electric current. There were 28 grade 11 students, second semester of academic year 2014 (November 2014 – March 2015), Narinukul School Office Mathayomsuksa Area 29, participated this study. The research methodology is classroom – based action research. The instrument used in this study were including POE 6 lesson plans on electric current, the instrument for reflecting the activities, learning activity note, observation field note, students’ project and quiz. The evaluation instruments Determining and Interpreting Resistive Electric Circuits Concepts Test (DIRECT) Version 1.2 Thai version. The qualitative data was analyzed and interpreted for the development scientific of concepts on electric current while the effectiveness had been analyzed by using basic statistics. The findings showed that the developing learning activities of electric current on a classroom – based action research, plan, action, observe and reflect on 4 steps. Consider the results from last activity. The present of students who passed the criteria in action cycles 1, 2 and 3 were equal to 40.20, 72.55 and 91.25 percentages respectively and the development of scientific of concept on electric current. The findings showed that students’ understanding of electric current concept that were taught using Predict – Observe – Explain: classroom – based action Research has been improvement.

Speaker: Mr Songsith Khunsawat (Department of Education in Science and Technology, Faculty of Education, Khon Kaen University, Thailand, 40002)

FullpaperSPC2015- Songsith Khunsawat - edit 1.docx

FullpaperSPC2015- Songsith Khunsawat - edit 1.docx

FullpaperSPC2015- Songsith Khunsawat - edit 1.pdf

FullpaperSPC2015- Songsith Khunsawat - edit 1.pdf

Poster Poster_presentaion_Mr.Songsith_Khunsawat.spc2015.pdf

8:00 AM The effectiveness of learning with guided lecture worksheets designed based on students’ learning difficulties

Guided lecture worksheets have been used in the introductory physics courses for first-year science students at Mahidol University. A set of worksheets was regularly distributed to students before starting each lesson and used as a teaching tool during each lecture. This was done throughout the course. In this study, we have developed worksheets for teaching electrostatics in large-class lectures. We began by researching students’ understanding in the year 2011 using pre- and post-tests, and interviewing them in order to identify their difficulties occurred when they learned with the worksheets (called ‘earlier worksheets’). We found that the earlier worksheets still could not well-address the learning difficulties for a large number of students. The average normalized gain was 0.45±0.22. Therefore, in 2012 we brought the student learning problems found in the year 2011 to develop the lecture worksheets (called ‘new worksheets’) and used them in the class. We found that there was the higher learning improvement with the average normalized gain of 0.61±0.20. To ensure that worksheets reconstructed yield a good effectiveness on learning electrostatics, we again used them in the year 2013. The average normalized gain was 0.55±0.20 which was quite steady. Amongst the three years devoted to the study, we can conclude that the development of worksheets based on students’ particular learning difficulties can make the difference of student learning outcomes.

Speaker: Ms Thanida Sujarittham (Science and Technology Education Programme, Institute for Innovative Learning, Mahidol University, Nakhon Pathom, Thailand 73170)

8:00 AM The Role of Core Hole Effects on Calculated Resonant Inelastic X-Ray Scattering Spectra of Graphene

The electronic band structure of graphene was calculated using the full-potential linearized muffin-tin orbital (FP-LMTO) method. Its resonant inelastic x-ray scattering (RIXS) spectra at various x-ray excitation energies were calculated based on Kramers-Heisenberg equation. It is found that the RIXS spectra show distinct dispersive features and are interpreted as being due to the conservation of crystal momentum during the RIXS process. However, the shift between XAS and XES energy scales due to the presence or absence of the core hole in the final state of these two processes, respectively, has to be taken into account, in order to obtain an optimal agreement between the simulated and experimental RIXS spectral. This shift is consistent with the observed changes in calculated PDOS induced by the presence of the core hole.

Speaker: Nuchalee Schwertfager (School of Physics and NANOTEC-SUT Center of Excellence on Advanced Functional Nanomaterials, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand; Thailand Center of Excellence in Physics (ThEP Center), Commission on Higher Education, Bangkok 10400, Thailand)

8:00 AM The study scientific concepts about conservation of mechanical energy in before and after learning through Predict-Observe-Explain approach for Grade 10 Students

The purpose of this research was to study scientific concepts of the student in conservation of mechanical energy both before and after learning through predict-observe-explain (POE) approach. The target group was 34 grade 10 students, Strisuksa School. The Office of Secondary Education District Area 27, Roi-Et, those studied in the second semester, academic of year 2014. The students’ scientific concepts in conservation of mechanical energy had been studied by using pre-test and the results were used as guiding to develop the conservation of mechanical energy lesson plans. The post-test was done soon after the POE finished. The evaluation tool consisting scientific conceptual test, multiple choices combined with short explanation their answer. The collected data were analyzed by interpreting into groups of scientific concepts and then comparing between pre-test and post-test. The findings revealed that student’ scientific concepts in prior learning of the student science could interpret into various categories and the majority of them were diverged from commonly scientific concepts, but the post-test performed that students scientific concepts generally converging to the scientific concepts. It could be concluded that the POE approach supporting the students to gain their understanding in conservation of mechanical energy.

Speaker: Mr Paritat Picitmal (Department of Education in Science and Technology, Faculty of Education, KhonKaen University, Thailand, 40002)

Poster Poster-SPC_2015_ID221.pdf

8:00 AM Thermodynamics of a Rubber Balloon

This study aimed to investigate thermodynamic properties of a rubber balloon including hysteresis and cooling effect of a deflated balloon. Firstly, pressure inside a balloon was measured using a Vernier pressure sensor and plotted as a function of the balloon averaged radius. Well-known mathematical models of inflated balloon including Mooney-Rivlin, Ogden and Gent-Gent models were used to fit experimental data. Secondly, hysteresis of pressure-stretch curve was investigated and it was found to depend on a turnaround radius. Thirdly, surface temperature of the balloon was investigated by using a Vernier surface temperature sensor. As a result when the balloon was deflated, temperature could decrease more than 5ºC depending on the initial radius and balloon thickness. These results can be used to develop teaching materials or demonstrations for an introductory or advanced thermodynamics course.

Speaker: Piimonpun Prasongsri (Department of Physics and Material Science, Faculty of Science, Chiang Mai University, Chiang Mai, 50200, Thailand; Physics Education Research Laboratory, Faculty of Science, Chiang Mai University, Chiang Mai, 50200, Thailand)

8:00 AM To design learning activities for the interference and the diffraction of light by using the learning package coorperate STAD techniqe : a case of secondary high school.

The objective of this study was designed the effective learning activities for studying in the interference and diffraction patterns of light. The learning package of the interference and the diffraction of light (LPID) were used with the cooperative learning, Student Teams-Achievement Divisions (STAD) technique, for the secondary high school students. LPID was designed that consists of the adjustable width single slit and double-slit two laser light sources (red, green) and acrylic box, that can be flow the smoke. The interference and the diffraction patterns were observed. The expectations of study in learning physics were investigated by Maryland Physics Expectations (MPEX) and the assessment for learning was observed by normalized gain. Research has shown results of this learning package.

Speaker: Ms Sumana Aungplachai (Department of Physics, Faculty of science, King Mongkut’s University of technology Thonburi , Bangkok ,THAILAND 10140)

Paper-sumana.docx

Poster 12nan.pdf

8:00 AM Transport of Macromolecules through Glomerular Basement Membrane

The main function of human kidneys is to filter blood and remove metabolic waste while retaining the normal blood composition and volume. The first step of this process is blood filtration through the glomerular capillary wall, which consists of multiple layers: endothelium cell layer, the glomerular basement membrane (GBM) and the epithelial foot processes with their interconnecting slit diaphragm. A hydrodynamic model is introduced to describe hindered transport of electrically neutral macromolecules through the slit diaphragm and the glomerular basement membrane (GBM). The glomerular basement membrane is modeled as an isotropic fibrous medium, where as the epithelial slit is modeled as a row of parallel cylindrical fibers, and the dimensionless flow resistance is calculated using finite element method. The non-uniform cylinder spacing is assumed to follow the gamma distribution. The mean value of the spacing and its standard deviation are calculated from the experimentally obtained hydraulic permeability using the Newton-Raphson's method. The averaged sieving coefficient is calculated by using those distribution functions and is compared with the total sieving coefficient of Ficoll from experiments.

Speaker: Numpong Punyaratabandhu (Department of Physics, Faculty of Science, Chulalongkorn University, Payathai Rd., Pathumwan, Bangkok, 10330 Thailand)

Transport of Macromolecules through Glomerular Capillary Wall(PDF Document).pdf

8:00 AM Using a Terminal Block as a Protoboard for the Development of Concepts related to Simple Direct Current Circuits

A protoboard is a thin plastic board used to hold electronic components such as resisters, transistors, and chips that are wired together, and is used to construct prototypes of electronic circuits. Although a protoboard is an appropriate tool for simply testing a prototype circuit or hooking up a quick experiment, it is difficult for students to use because they become confused about the connection pattern of the join holes along the horizontal and vertical lines and the differences between a real circuit constructed on a protoboard and a schematic diagram in a textbook. This study used a terminal block as a protoboard and involved 30 students in grade 11 in the second semester of the academic year 2014 at Loeipittayakom School, Amphur Muangloei, Loei province. The research tools consisted of an experimental kit, lesson plans using the predict-observe-explain technique, and the Interpreting Resistive Electric Circuit Concepts Test (DIRECT). Data were analyzed by t-test and normalized gain. Results showed that the mean post-test score was significantly higher than the mean pre-test score at a statistical level of .01. The average class normalized gain was at the medium gain level (0.35). The study illustrated that a terminal block can be used to develop students’ concepts.

Speaker: Mr Phusit Juntana (Department of physics, Faculty of Science, UbonRatchathani University, Thailand, 34190)

8:00 AM Using Active Workbooks as a Tool to Develop Concepts and Problem-solving Skills in Work and Energy

This research aimed to develop students’ conceptual understanding and problem-solving skills in work and energy work using active workbooks. These workbooks were prepared in advance by the teacher and consisted of essential concepts, ideas, diagrams, graphs, problems, and conclusions. The participants in the research were 23 grade 10 students at Khiansaphittakom School, AmphurKhainsa, SuratThani province in the second semester of the 2014 academic year. The research tools consisted of active workbooks,lesson plans based on the predict-observe-explain technique, the Work and Energy Evaluation, Test and the evaluating learners’ satisfaction. The results of the study demonstrated a significant increase in student learning performance both concepts and problem solving skills with the application of the active workbooks and the targeted groups were satisfied by using active workbooks.

Speaker: Mrs Lanjakorn Tongrueng (Department of physics, Faculty of Science, UbonRatchathani University, Thailand 34190)

8:00 AM Using colour light mixer cooperate with CIPPA model to teach primary colour light and their mixed: A case of secondary high school students.

The teaching technique about the understanding for colour light and their mixed that used the colour light mixer together with CIPPA model was presented in this study. The colour light mixer was made from three Light Emitting Diode (LED) e.g., red , green and blue. Our colour light mixer can be generate a smooth and clear colour and can be control light intensity. For the teaching technique the CIPPA model was used to teach girl students for secondary high school cooperate with the colour light mixer. The understanding for primary colour light and their mixed was determined by using the normalized gain.

Speaker: Ms Rapeepat SONKRUA (Department of Physics, Faculty of science, King Mongkut’s University of technology Thonburi , Bangkok ,THAILAND 10140)

Poster Poster_SPC2015.pages

8:00 AM Using Simple Experiments incorporated with a Laboratory Group Investigation Model to Develop Conceptual Understanding of Static Electricity

The purpose of this research was to study the development of students’ conceptions of static electricity using a laboratory group investigation model. The participants were 34 grade 10 students from Srikoonwittayabunlang School, Amnatcharoen in the second semester of the 2014 academic year. A one group pre-test/post-test design was employed in the study, and the research tools consisted of lesson plans based on the group investigation technique and a static electricity conceptual test. Data were analyzed by the use of average percentages, standard deviations, t-test, and normalized gain. Results showed that there was an improvement in the mean post-test score compared to the mean pre-test score at a statistically significant level of .05.The average class normalized gain was at the medium gain level.

Speakers: Mr Akapong Buachoom (Department of physics, Faculty of Science, UbonRatchathani University, Thailand, 34190), Dr Sura Wuttiprom (Department of physics, Faculty of Science, UbonRatchathani University, Thailand, 34190)

Fullpaper spc2015.docx

Fullpaper spc2015.pdf

8:00 AM → 11:00 AM Astronomy, Astrophysics and Cosmology (Sponsored by NARIT)

8:00 AM On the role of short period Cataclysmic Variables from Catalina Sky Survey

Cataclysmic Variables (CVs) are close binaries consisting of an accreting white dwarf and a low-mass main sequence companion. We have initiated in searching new CVs using their outburst properties with the primary aim to identify short-period systems which are rare but are great of importance to understand close binary evolution. Here, we present time-resolved photometry of new CVs in superoutburst discovery by Catalina Real-Time Transient Survey (CRTS). The observations have been carried out at 2.4 m Thai National Telescope, Doi Inthanon, and 0.6 m PROMPT8 telescope, located at Cerro Tololo Observatory, Chile. Superhump structure found in their light curves suggested that these CVs are short- period systems with the orbital period below the 2-3 h period gap. Furthermore, we will discuss recent status of CRTS CVs sample compared to the previously known CVs discovered by various means.

Speaker: Ms Sirinapa Arjyotha (Program of Physics, Faculty of Science and Technology, Chiang Rai Rajabhat University, Chiangrai, Thailand 57100)

Paper SPC2015_ARJYOTHA_Sirinapa_20150521.docx SPC2015_ARJYOTHA_Sirinapa_20150521.pdf

8:15 AM The oscillation spectra of the oEA stars

We present results of study of oscillation of a sample of A-type mass-accreting components of Algol-type eclipsing binary stars (so called oEA stars). This work is a part of ongoing THAi Southern Survey for OEA Stars (THASSOS). High-precision photometry obtained at different observatories was used to investigate the low-amplitude acoustic variations of brightness of primary components. The new discovered oEA stars and detected acoustic oscillations are presented and discussed.

Speaker: Dr David Mkrtichian (National Astronomical Research Institute of Thailand, Chiang Mai 50200, Thailand)

8:30 AM Analysis of Peculiar Dips Changed of SDSS J102102.25+174439.9 Light Curve

We followed up the new eclipsing white dwarf main sequence SDSS J102102.25+174439.9 with a short orbital period of 0.14 days from the Sloan Digital Sky Survey The system has been observed by using on the 2.4m telescope at the Thai National Observatory (TNO) with ULTRASPEC instrument. Our multi-band observations shows peculiar dips about 15 minute after the primary eclipse. Such dips in WDMS systems were only observed on one occasion of the light curve of QS Vir earlier. The dips in SDSS J1021+1744 are unique because they present in different wavelengths at approximately the same phase. It is possible that these dips are caused by the ejected materials from an active companion star, such as in QS Vir. The light curve in g′ filter exhibits deep and narrow features, implying that the materials which pass in front of the white dwarf in SDSS J1021+1744 must be dense and small in size. Furthermore, the stellar and orbital parameters SDSS J1021+1744 are presented.

Speaker: Mr Khunagorn Chanthorn (School of Physics, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand)

8:45 AM Follow-up Photometry of New Eclipsing PCEBs from the Sloan Digital Sky Survey: SDSS J214140.43+050730.0

Post common-envelope binaries (PCEBs) are known as one of the end products of the complex common-envelope process. These systems typically consist of white dwarf star with a low mass companion. While most of PCEBs usually have short orbital periods of a few hours, some systems are found to be in long (>1 day) period. In this work, we present the preliminary result of our follow-up photometric observation on SDSS J214140.43+050730.0 by using the 2.4m Thai National Telescope with ULTRASPEC instrument. The system is a new cataclysmic variables (CVs) which is listed among the recently found white dwarf main sequence binaries from the Sloan Digital Sky Survey. The observation for SDSS J2141+0507 is done on 9th, 22nd, 24th and 25th December 2014 in the SDSS $g^{\prime}$ filter, $KG5^{\prime}$ filter, $r^{\prime}$ filter and $i^{\prime}$ filter, respectively. Our preliminary result on SDSS J2141+0507 show that T0(HJD) and an orbital period are 2457014.00774986 and 0.05469 days, respectively.

Speaker: Mr Kittipong Wangnok (School of Physics, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand)

9:00 AM Photometric Observation and Analysis of Hot Uranus Exoplanet GJ3470b by Transit Method

GJ3470b is a Uranus-mass exoplanet, orbiting around M dwarf (Bonfils et al. 2012). In this work, R-filter transit observations were conducted by using the 0.5-meter telescope at Thai National Observatory (TNO) and the 0.6-meter telescope at Cerro Tololo Inter-American Observatory (CTIO) in 2013-2015. From the light curves, the orbital elements of GJ3470b were obtained. In addition, the time of minima which obtained from observed data were used to compute O-C diagram. The result reveals that there is no major change in orbital period of GJ3470b.

Speaker: Ms Sawatkamol Pichadee (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand)

9:15 AM Black hole in Massive Gravity and its thermodynamics

Massive gravity is one of the well-known modification of Einstein’s general relativity by promoting the massless mediator, so-called graviton, to be a massive one. As the modified gravity, it is natural to consider the black hole solution of the theory. Here we present the static spherically symmetric black hole solution in massive gravity, proposed by de Rham, Gabadadze, and Tolley, along with its thermodynamics descriptions. The solution we found is in the form of Schwarszchild solution with additional terms due to massive gravity, including the cosmological-like term without introducing a bare cosmological constant, which is quite natural in massive gravity. We also found that introducing the graviton mass also affects thermodynamical natures of the black hole. Furthermore, the phase structure of the solution is analyzed in order to investigate the thermodynamical stability of the black hole.

Speaker: Mr Lunchakorn Tannukij (Department of Physics, Faculty of Science, Mahidol University, Bangkok 10400, Thailand)

9:30 AM Particle's Trajectory Around Static and Spherically Symmetric black hole in Massive Gravity Theory

We attempt to explain the trajectory of a particle around the massive object using an effective gravitational potential obtained from dRGT massive gravity theory. The dRGT massive gravity is the modification of the Einstein’s general relativity (GR) by considering theory with a massive graviton, while in GR the graviton is massless. We start with finding the static and spherically symmetric black hole solutions of the modified Einstein equations in empty space. We found that at small scale, the solution recovers Einstein’s gravity with small correction contributed from graviton mass. At large scale, the dominant contribution provides the accelerating expansion of the universe since the graviton mass serves as cosmological constant. The corrections in the solution may provide an opportunity to distinguish the particle motion between massive gravity and GR.

Speaker: Mr Supakorn Saelue (Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok, THAILAND 10330)

Paper Particle's_Trajectory_Around_Static_and_Spherically_Symmetric_black_hole_in_Massive_Gravity_Theory.pdf

9:45 AM Star Formation and Age-Metallicity Relation in a Galaxy Group NGC 4065

We present a study of star formation, stellar age and metallicity, and interactions between galaxies in a low-redshift group, NGC 4065 group. Imaging data were taken from 2.4 meter telescope at Thai National Observatory (TNO) for B, V and R$_\mathrm{C}$ broadband filters and [S$~\small{\mathrm{II}}$] and Red-continuum narrowband filters. There are 21 galaxies in our sample. The star formation rate is represented by the equivalent width of hydrogen alpha (EW(H$\alpha$)). Stellar age and metallicity are examined by using the Medium resolution INT Library of Empirical Spectra (MILES) for the stellar population synthesis model predictions. The result shows that most of early type galaxies (ETGs) with EW(H$\alpha$)) in the sample galaxies less than 10 Å, gas-deficient galaxies, while late type galaxies (LTGs) show more EW(H$\alpha$) and bluer than the ETGs. That means star formation activity in the LTGs could be triggered by ram-pressure stripping and tidal interaction between galaxy members due to dense environmental effect in the compact group.

Speaker: Mr Orarik Tasuya (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand)

10:00 AM Photometric Monitoring of Active Galactic Nuclei using the Thai Robotic Telescope in Chile

We report the ongoing variability monitoring program for a well-defined, flux-limited sample of active galactic nuclei (with Bj<18 mag) through a multi-band optical imaging using Thailand's 0.6-m remotely-operated telescope at Cerro Tololo Inter-American Observatory, Chile. Our goal is to search for month-time scales outbursts to identify potential targets for spectroscopic follow-up to estimate the broad-line region size through reverberation mapping technique. We have developed a Python pipeline based on the publicly available SWARP or SExtractor to efficiently extract the photometry and produce light-curves in the B,V, and R bands. We typically achieve a consistent photometric uncertainty of < 0.05 mag for targets at 14-15 mag under optimal conditions at an average cadence of two days or better for a number of objects during a 2014 - 2015. Here, we demonstrate the use of our machinery to monitor PG1302-102, which has recently been found to be the first candidate of a binary supermassive blackhole at sub-kpc distance, at accuracy approaching 0.01mag over 14 months.

Speaker: Mr Bovornpratch Vijarnwannaluk (Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok 10330 , Thailand)

Photometric Monitoring of Active Galactic Nuclei using the Thai Robotic Telescope in Chile_word.docx

Photometric Monitoring of Active Galactic Nuclei using the Thai Robotic Telescope in Chile_word.pdf

10:15 AM CMB cold spot anomaly from cosmic void

One of the strongest evidence of the currently favoured standard ΛCDM (Lambda cold dark matter) model with the Big Bang origin came from the Cosmic Microwave Background (CMB) radiation measurement which show us the average temperature of the universe is 2.725 K with the Gaussian fluctuations of about 18 µK RMS. However there presents some anomalies that can be observed by CMB experiment. One of strange structures is the cold spot anomaly originally detected by NASA WMAP and now confirmed by the ESA Planck satellite mission. The temperature of the large cold spot is significant lower than average temperature. Moreover the size of the cold spot is notably larger than expectation, it radius is $5^{\circ}$ on sky. One of the best explanations of this cold spot is the integrated Sachs-Wolfe effect (ISW) cause by a single large cosmic void. Many research used Lemaître-Tolman-Bondi (LTB) metric embedded in ΛCDM background to construct cosmic void and determine ISW effect for explanation of the large cold spot but they ignored the small-scale effect from weak gravitational lensing. In this research we try to calculate ISW effect and weak lensing effect from LTB metric. In addition we used another cosmic void density profile from N-body simulation (Hamuas et,al 2014) to evaluate both ISW effect and weak lensing. And finally both results of LTB metric and cosmic void density profile will be compared to each other.

Speaker: Mr Anut Sangka (School of Physics, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand)

10:30 AM Some Recent Developments in Statistical Mechanical Description of Galaxy Clustering

Cluster expansion method of statistical mechanics has proved to be a useful tool in describing gravitational galaxy clustering as a cosmological many body problem. The method yields a spatial galaxy distribution function, a generalized Poisson, in excellent agreement with observations and N-body simulation results. Some recent developments include distribution function for a multi component system, galaxy clustering as a phase transition, a rigorous derivation of the clustering parameter, distribution function for the system of galaxies for any ratio of gravitational potential to kinetic energies, studies on the critical phenomena in the cosmological many-body problem, derivation of the fundamental form of two point correlation function etc. This paper elucidates these recent developments and their implication for cosmology.

Speaker: Dr Manzoor Ahmad Malik (Department of Physics, faculty of Physical and Material Sciences, University of Kashmir, Srinagar 190006, India)

10:45 AM A galaxy rotation curve from a modified Newtonian model based on Mach’s principle

The rotation curve of the visible stars and gas in a galaxy can be presented by plotting its orbital velocity. However the galaxy rotation curve obtained by using the relation of Newton’s universal gravitation fails to explain the observed rotation curve. This has led to the dark matter hypothesis. At present there is no direct evidence for the detection of dark matter and the area is still open for an alternative. In this work, we present a computer simulation for the galaxy rotation model. Our simulation can show that the galaxy rotation curve simulated by using the Newtonian relation is incorrect as expected. Instead of pursuing the dark matter hypothesis we introduce a relation of central force between matter based on Mach’s principle. By combining the Newton’s universal gravitation with this relation we will show the corresponding galaxy rotation curve.

Speaker: Rak Chitchamnong (Department of Physics, Faculty of Science, Mahidol University, Bangkok 10400 Thailand)

Slides A_galaxy_rotation_curve_from_a_modified_Newtonian_model_based_on_Mach’s_principle.pptx

8:00 AM → 10:45 AM Atomic Physics, Quantum Physics, Molecular and Chemical Physics

8:00 AM Adiabatic Interaction between Rydberg Atom and Ground-State Atom

The adiabatic interaction between Rydberg atom and ground-state atom of Rb2 was numerically investigated. The semi-molecular potentials were calculated by matching the wave function of Rydberg electron using Kirchhoff integral with Coulomb Green’s function that corporates the quantum defect correction. The interaction potential was employed to pinpoint the principle quantum number of particular rubidium-85 Rydberg atom that demonstrates crucial structure demanded by our novel Rydberg-assisted single-atom trapping scheme.

Speaker: Waranont Anukool (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand)

8:15 AM Single Rubidium-85 Atom in a Far Off-resonance Dipole Trap

We have trapped a laser-cooled single rubidium-85 atom in an optical dipole trap using sub-Poissonian loading scheme. The trap beam with 4mK depth was produced with 830nm focused laser beam. Our optical circuits based on the two-beam trap and homemade equipments are described. The photograph of a single rubidium-85 atom taken for the first time in Thailand is presented.

Speakers: Mr Nuttanan Tanasanchai (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand), Waranont Anukool (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand)

8:30 AM Four Level Dynamic in Rubidium-85 Magneto-Opical Trap

We use the density matrix formulation to study the dynamic of atom-photon interaction of Rb-85 atoms under the cooling and repumping laser fields in a magneto-optical trap (MOT). The spontaneous emission process is taken into account using the fully-quantized theory. The obtained master equations are numerically solved for the four-level system including two levels of $5^2S_{1/2}F=2,3$ and two levels of $5^2P_{3/2}F=3,4$. The steady solution that naturally gives the probability of finding trapped atoms occupying each level in MOT is analyzed in detail.

Speakers: Rattakorn Kaewuam (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand), Waranont Anukool (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand)

8:45 AM Concentric-Ring Atom Interferometer

We investigate applicability of a novel atom interferometer consisting of two concentric rings for precision measurements. The investigation is carried out with a computer simulation of Gross-Pitaevskii equations which monitors low energy vibrational modes inside of the interferometer under various ring geometries. From each eigenmodes, the fringe visibility between thermal ensemble and degenerate Bose gas are compared.

Speaker: Kritsana Srakowl (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand)

9:00 AM Split-Operator Method for Fabry-Perot Interferometry

We numerically calculate transmission, reflection and cavity-modes inside a Fabry-Perot interferometer using the split-operator method. Unlike traditional methods, the cavity's eigenmodes are computed from temporal propagation instead of spatial propagation which makes the calculation of cavity scanning more practical. Also the split-operator coexist with master equations of fully quantum mechanics calculation of atom-photon interaction in the Fabry-Perot cavity.

Speaker: Jindaratsamee Phrompao (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand)

9:15 AM The study of Cavity Quantum Electrodynamics as a heralded quantum memory

We consider the efficient creation of heralded dicke states in an atomic ensemble trapped in a high finesse optical cavity. Weak resonant light in free-space mode transverse to the cavity is efficiently absorbed by the optically dense sample. Subsequent stimulated Raman scattering into the cavity mode dominates over free space scattering because of the high single atom cooperativity of the cavity. We discuss experimental progress towards realizing heralded atom-photon interfacing.

Speaker: Apichayaporn Ratkata (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand)

9:30 AM Phase structure and microstructure of CaZrO3 powder prepared by molten salt method

Lead-free calcium zirconate (CaZrO3) is an important raw material for industry applications because of its excellent thermal and electrical properties such as, high dielectric constant and low dielectric loss [1]. However, in order to achieve pure CaZrO3 powder, high calcining temperatures ( 1300 $^\circ$C) and long dwelling times for solid reactions between the CaCO3 and ZrO2 powders are required [2]. It is well known that the molten-salt method can synthesize powders at lower temperatures and is a simple technique. Thus, this work is to investigate the preparation of lead-free CaZrO3 powder by the molten salt method. The starting powders of CaZrO3 were weighed, mixed and ball-milled. After that, they were mixed with KCl:NaCl salt in the ratio of 1:1. Then calcined at temperatures of 900-1050 $^\circ$C and washed with hot-distilled water. Phase formation and microstructure of CaZrO3 powders were studied by using an X-ray diffractometer (XRD) and scanning electron microscope (SEM). The phase structure of the powder corresponded to CaZrO3 peaks (JCPDS No. 035-0590). Moreover, uniform particle size, agglomerated particles and equiaxed grains of CaZrO3 powders were observed.

Speaker: Ms Wasuporn Hirunsit (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand)

9:45 AM Quantum Algorithm for Finding Roots of $n^\mathrm{th}$ Degree Polynomials

Quantum algorithm is an algorithm for solving mathematical problems using quantum systems encoded as information, which is found to outperform classical algorithms. The objective of this study is to develop a quantum algorithm for finding the roots of $n^{\mathrm{th}}$ degree polynomials where $n$ is any positive integer. In classical algorithm, the resources required for solving this problem increase drastically when $n$ increases and it would be impossible to practically solve the problem when $n$ is large. It was found that any polynomial can be rearranged into a corresponding companion matrix, whose eigenvalues are roots of the polynomial. This leads to a possibility to perform a quantum algorithm where the number of computational resources increases as a polynomial of $n$. In this study, we construct a quantum circuit representing the companion matrix and use eigenvalue estimation technique to find roots of polynomial. The complexity of this quantum algorithm is also compared with a classical algorithm for solving the same problem.

Speaker: Mr Theerapat Tansuwannont (Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand)

10:00 AM Rashba Effect from Schwinger’s Oscillator Model

Synthetic magnetic field is recently demonstrated theoretically and experimentally in an ensemble of neutral atoms through Rashba effect. In this presentation, Schwinger’s oscillator model is used to demonstrate the Rashba effect in favor of traditional angular momentum bases. The Schwinger’s model is useful in setting up the master equation of atoms interacting with field both in free space and cavity to reflect the synthetic field.

Speaker: Mr Hariphan Philathong (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand)

8:00 AM → 10:45 AM Material Physics, Nanoscale Physics and Nanotechnology

8:00 AM Fabrication and Characteristic of BaTiO${}_3$ Based Ceramic by Molten Salt Synthesis

In this work, barium titanate; BaTiO${}_3$ (BT) powder was successfully synthesized by the molten-salt method. The molten-salt method is a simple technique for preparation of fine powder also can control the shapes and sizes in the order of nanometers. The metal oxides of BaCO${}_3$ and TiO${}_2$ were mixed and ball-milled. After that, BT powder were mixed with KCl : NaCl salt and then washed with hot DI water. Heating temperatures were studied in the range of 800 to 1000 ${}^{\circ}$C with using dwelling time of 2 hours. In order to investigate the microstructure and phase structure, they were studied by SEM and XRD techniques. The results found that all samples showed a single pure perovskite phase using a low temperature of $\sim$900 ${}^{\circ}$C , which was confirmed by JCPDS No. 01-083-1879. The grain shapes of BT powder had a mixing of polygon and equiaxed grains. The particle size of BT powder increased from $\sim$381 to $\sim$860 nm with increasing heating temperatures from 800 to 1000 ${}^{\circ}$C. Results confirmed that BT nanoparticles were obtained by using the molten salt method.

Speaker: Ms Manlika Kamnoy (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai, THAILAND 50200)

8:15 AM Synthesis of Carbon-Encapsulated Fe${}_3$O${}_4$ for Supercapacitors Electrode

In this project, carbon encapsulated Fe${}_3$O${}_4$ for supercapacitors electrode was synthesized using Fe${}_3$(No${}_3$)${}_3$ 9H${}_2$O and C${}_6$H${}_1{}_2$O${}_6$ as precursors and NaCl as supporting material. The mixture was annealed at 700 ${}^{\circ}$C, 720 ${}^{\circ}$C, 750 ${}^{\circ}$C and 770 ${}^{\circ}$C in argon atmosphere for 2 hours and heated at 250 ${}^{\circ}$C in air for 6 hours. The results showed that the supercapacitors with carbon encapsulated Fe${}_3$O${}_4$ had the maximum specific capacitance of 48.5 F/g in 1 M of Na${}_2$SO${}_4$ aqueous electrolyte. This could be attributed to a good electrical conductivity of carbon and the promotion of redox reaction in Fe${}_3$O${}_4$.

Speaker: Mr Nattapon Kasangam (Department of Physics, Faculty of Science, Khonkaen University, Khonkaen, THAILAND 40002)

8:30 AM Synthesis and Characterization of Cu${}_{2-x}$Te Quantum Dot on ZnO Nanoparticles

It has been shown that semiconducting materials with particle size comparable to exciton Bohr radius, called “quantum dot,” exhibit distinct physical property referring to their bulk. This leads to various applications in computing, biology, solar cell, light emitting, and photodetector. In this work, we synthesized quantum dots of copper telluride on films of zinc oxide using successive ionic layer absorption technique at low temperature. The quantum dots were characterized by transmission electron microscope, scanning electron microscope, x-ray diffractometer, and UV-Vis spectroscope for particle size, morphology, crystal phase, and optical property, respectively. The results showed that the quantum dots were orthorhombic of Cu${}_{1.44}$Te with the average particle size of 5 nm. The growth mechanism of quantum dot will be explained.

Speaker: Mr Aram Boonti (Department of Physics, Faculty of Science,Chiang Mai University, Chiang Mai, THAILAND 50200)

8:45 AM Controlling the thickness of silicon dioxide shell of iron boride nanoparticles

Iron boride nanoparticles are one of soft ferromagnetic materials which also contain boron. These properties combined the possibility of magnetically targeting the nanoparticles, use their hysteresis loop to cause thermal damage of tissue, as well as provide boron neutron activation medicine in cancer therapy applications. Unfortunately, iron boride may be easily oxidized under oxygen rich atmospheres. Thus, they must be coated with protecting layers such as silicon dioxide. In this project, we synthesized iron boride-silicon dioxide and enlarged the silica shell thickness by varying the concentration of the silica forming precursor tetraethyl orthosilicate (TEOS). The particle shape, and the silica shell thickness was then studied using transmission electron microscopy. The results showed that iron boride-silicon dioxide with spherical shape and well formed silica shell can be obtained with various thicknesses. After measurement, we got a mean size of the whole particle about 83 nm, the iron boride core size about 74 nm and the thickness of primary shell about 5 nm. The additional thickness of the silica shell was accomplished by further hydrolysis of TEOS using the primary Fe$_2$B nanoparticles as seeds. The use of concentrations of TEOS of 3.16 x 10$^{-4}$, 6.31 x 10$^{-4}$ and 1.26 x 10$^{-3}$ mol/l yielded 17 nm, 20 nm and 84 nm thick shell, respectively. We compared the experimental thickness of the silica shell with the expectation obtained from considering the amount of TEOS used and the initial particle size. In summary, silica shell thickness increased as the TEOS precursor concentration increased.

Speaker: Ms Tipnirin Vajanarat (Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok, THAILAND 10330)

9:00 AM High-Quality Pure Cubic GaN on Patterned GaAs (001) Substrates with [110]-Oriented Stripes by MOVPE

It is known that the cubic GaN (c-GaN) structure using epitaxial lateral overgrowth (ELO) could be controlled by mask fill factor (ratio of the open width to the pattern period), mask direction, and growth temperature. Particularly, ELO GaN on the [110] oriented stripe-patterned GaAs (001) exhibits hexagonal phase structure. On the other hand, in this work, we have proposed the use of the [110] oriented mask stripe-patterned SiN$_{\textrm{x}}$/GaAs (001) with an optimized mask fill factor of 0.8 as a substrate for the metalorganic vapor phase epitaxy (MOVPE) growth of ELO c-GaN to realize a layer with high cubic-phase purity. Our results demonstrate that ELO c-GaN with high cubic-phase purity was successfully performed on the window stripes opening along the [110] direction at growth temperature 900 $^{\circ}$C. Consequently, a trapezoidal shape with (001) top surface and (111)B sidewall facets, which is a characteristic of cubic structure, was clearly observed the c-GaN stripes. XRD measurements showed that the full-width at half-maximum of c-GaN (002) rocking curve was determined as the narrowest as 14.9 arcmin, indicating to a high crystalline quality of ELO c-GaN. The integrated volume amount of hexagonal phase inclusion, which was examined by XRD reciprocal space mapping, was decreased from 30.5% to 16.8% with increasing thicknesses from 1.4 µm to 12.0 µm, respectively. On the basis of our results, the hexagonal phase generation can be suppressed by controlling the growth feature, which is sensitive to mask fill factor and growth temperature.

Speaker: Pattana Suwanyangyaun (Nanoscience and Technology, Graduate School, Chulalongkorn University, Bangkok, THAILAND 10330)

9:15 AM Rapid thermal annealing and structural properties of lattice-matched InGaPN on GaAs (001) grown by MOVPE

Effects of rapid thermal annealing on the structural properties of InGaPN layers grown on GaAs (001) substrates by metal organics vapor phase epitaxy (MOVPE) have comprehensively investigated by using high resolution X-ray diffraction (HRXRD) and Raman spectroscopy, scanning electron microscopy (SEM) and atomic force microscopy (AFM). To obtain the lattice-match InGaPN on GaAs, flow rates of trimethylindium (TMIn, In precursor), trimethylgallium (TMGa, Ga precursor) were respectively kept at 14.7 and 8.6 µmol/min for all the samples. While, the N content was controlled by varying flow rate of dimethyhydrazine (DMHy), which is the N precursor, from 300, 700 and 1,100 µmol/min. Based on HRXRD and Raman scattering results, the In content was examined to be ~56.2 at%. The N content was estimated to be 1.1 at%, 1.6 at% and 1.9 at% with increasing DMHy flow rate. Lattice-mismatch lower than 0.3% was confirmed for all the samples, corresponding to a lattice-matching condition. Each samples were cut into small pieces and, then, annealed by rapid thermal annealing (RTA) process. Annealing temperature was fixed at 650 $^o$C, which is an optimum growth temperature of GaAs buffer layer. Annealing time was varied from 0, 30, 60, 120 and 180 s, in order to verify a composition uniformity and crystal ordering. With increasing annealing time up to 120 s, the N content was slightly increased, while for higher annealing time, the N content was dramatically reduced. Also, root mean square (RMS) roughness was observed to be reduced, when annealing time is lower than 120 s. Raman scattering results demonstrated a lowering of b/a ratio with an increasing N content, resulting in a higher crystal ordering. Furthermore, b/a ratio also decreased after RTA. This implies that the N content was increased due to RTA, which is agreed to the HRXRD results. As a result, the RTA process with optimal annealing time significantly improve the structural properties of the lattice-matched InGaPN layers on GaAs (001) substartes.

Speaker: Mr Phongbandhu Sritonwong (Nanoscience and Technology, Graduate School, Chulalongkorn University, Bangkok, THAILAND 10330)

9:30 AM Chemical Vapor Deposition (CVD) Synthesis of Graphite Encapsulated Magnetite Nanoparticles for Counter Electrode of Dye-sensitized Solar Cells

In this project, graphite encapsulated magnetite nanoparticle in carbon matrix was synthesized using a chemical vapor deposition (CVD) and used as a counter electrode of dye-sensitized solar cells (DSSCs). The CVD reaction employed iron(III)nitrate nanohydrate and glucose as precursors, NaCl as a supporting material and methane as a carbon source. The reaction temperature was varied at 700, 750, 780 and 850 ${}^{\circ}$C. The DSSC with the synthesized graphite encapsulated magnetite nanoparticle in carbon matrix counter electrode performed the highest solar cell efficiency of 4.56 %. This was higher than the DSSCs with graphite counter electrode produced by the same CVD condition and that with magnetite nanoparticle counter electrode which were 2.36 % and 1.34 %, respectively, and comparable to that of the DSSC with Pt counter electrode which was 4.72 %. The high performance of the graphite encapsulated magnetite nanoparticle in carbon matrix counter electrode was accounted for a combination of a good electrical conductivity of graphite and carbon matrix and a good catalytic property of magnetite nanoparticles.

Speaker: Sujinda Chaiyachad (Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen, THAILAND 40002)

8:00 AM → 9:15 AM Optics, Non-linear Optics, Laser Physics, Ultrafast Phenomena

8:00 AM Cuvette’s effect correction for practical light-scattering experiment

Light scattering is a non-invasive technique to characterize small particles, such as microorganism and powder etc. Therefore, it is wildly used in many fields, for instance, pharmaceutical technology and microorganism detection. There are many authors theoretically calculate the scattered light from a particle for fitting to the experimental measurement to determine the particle characteristics. However in practical experiment, scattering particles are usually contained in a cuvette, therefore the detected scattered-light does not come from only a single particle as the theory but combination of the scattered light from each particle contained in the cuvette. Moreover, the refraction and transmission effects cause the deviation of the experimental scattered light from the theory. Consequently, a correction method for applying the scattering theory to the practical has been developed in this research. It combined Fresnel refraction and transmission theories with Snell’s law to correct the effects from the cuvette and integration method to correct the effect of particle collection. The scattering theory with correction was validated using 1.1 µm and 3.0 µm in size polystyrene latex beads suspended in de-ionized water (LB11 and LB30, respectively). The measurement results showed good agreements between the scattered light measured from the experiment and the scattered light calculated from the scattering theory with correction. The correlation between scattered light from the experimental measurement and the scattering theory with correction was 0.996 whereas the scattering theory without correction was 0.894 for LB11. In case of LB30, the correlation between the experiment and the theory with and without correction were 0.979 and 0.685, respectively. These fitting results of scattered intensities from experiment and the scattering theory with and without correction showed that the presented correction methods by Fresnel refraction and transmission and Snell’s law and integration method were effective to correct the factor caused by the combination of particles and the cuvettes surface in the scattering set up.

Speaker: Somporn Buaprathoom (Mahidol Wittayanusorn School, 364 Moo 5 Salaya, Phutthamonthon, Nakorn Pathom, Thailand 73170)

8:15 AM Arc Discharge Drawing Silica Nanowires

We propose a new approach, the Arc Discharge Drawing (ADD) technique, to fabricate silica fibers with diameters less than the wavelength of commercial available lasers. With this single-step technique, silica wires with diameters as small as 50 nm were demonstrated. This technique would provide an attractive alternative to current approaches to fabricate the silica nanowires. For ADD technique, a standard optical fiber is placed in two fiber mounts. One of the fiber mount performs as the computer-controlled stage that pulls the fiber at various speeds in the range of 2 mm/s to 15 mm/s. During this computer-controlled fiber drawing process, the fiber is heated by the arc discharge serving as the heat source. The arc discharge is supplied with a D.C. current from a rectifier with a controlled voltage to 20 kV. The nanowires can be fabricated by varying the voltage in the range of 4 kV to 5 kV. The optimum operational voltage is determined by the scanning electron microscope (SEM) images of the fabricated silica nanowires. Based on the SEM images, it is evident that nanowires obtained by the ADD technique exhibit great diameter uniformity and large length. In addition, the fabricated silica nanowires are flexible due to their large aspect ratio between the diameter and the length. Furthermore, the nanowires can be bent and twisted without breaking.The bent and twisted silica nanowires are extremely useful to guide laser light for small scale photonic devices. In this study, the nanowires obtained by ADD technique were also investigated in the aspect of guiding 633-nm wavelength light. The results reveal the high transmission losses thus providing the greater evanescent field. This represents a significant advancement in the field of nanophotonics. Due to their extraordinary compactness and excellent optical properties, nanowires will find a whole range of nanoscale photonic devices.

Speaker: Rattanachai Kowong (Department of Industrial Physics and Medical Instrumentation, Faculty of Applied Science, Lasers and Optics Research Group (LANDOS), Science and Technology Institute, King Mongkut's University of Technology North Bangkok)

Paper Arc_discharge_drawing_silica_nanowires-Fullpaper_SPC2015.doc Arc_discharge_drawing_silica_nanowires-Fullpaper_SPC2015.pdf

8:30 AM An optical surface measurement for laser removal of graffiti

In this paper, we present the creation of a new class of an optical surface measurement based on laser scattering principle. This technique is aimed to serve as a non-destructive testing tool for laser removal of graffiti. The laser scattering system consists of a weak HeNe laser beam that is split into two arms, the reference arm and the sample arm. The reference arm serves as the unaffected graffiti surface while the sample arm performs as the affected graffiti surface. The diffuse reflection of the scattering light from both arms is projected on a screen. The image of the screen is then captured by a CCD camera. Full Width at Half Maximum (FWHM) of the intensity distribution of the image is analyzed by using a developed image processing program. The measured FWHMs of the two arms can be analyzed and used to identify the laser cleaning threshold. In this study, an experiment on the angular laser removal of graffiti was setup as an example to testify the diagnostic system under practical conditions. A Q-switched Nd:YAG laser operating at 1.06 microns was used to remove graffiti from mortars. The pulse duration of the laser is 10 ns. The laser cleaning procedures were performed by changing the incident angle of the laser beam. The rate of application of pulses was remained at 1 Hz. The laser fluence was varied from 0.1 J/cm$^{2}$ to 7 J/cm$^{2}$. After the application of individual pulse, the assessment of quality of laser cleaning was performed with the laser scattering measurement. The laser fluence of the cleaning threshold varies between 2 J/cm$^{2}$ and 3 J/cm$^{2}$ according to the sample properties. This laser scattering measurement provides the simplicity of the optical setup and allows the further development of an online surface inspection potentially exceeding the performance of the current optical inspection technology.

Speaker: Mr Phumipat Kittiboonanan (Department of Industrial Physics and Medical Instrumentation, Faculty of Applied Science, King Mongkut’s University of Technology North Bangkok, Bangkok 10800 Thailand)

Paper FullpaperSPC2015_Graffiti.doc FullpaperSPC2015_Graffiti.pdf

8:45 AM The Development of Proving an Existence of Single Photon by Three Detectors

The study of quantum optics in Mahidol Wittayanusorn School has established for four years. The latest study was conducted by attenuating blue laser and using the down-conversion crystal. The result of that study was a degree of second-order coherence = 0.412 ± 0.014 which violating the classical inequality. However that is not completely confirmed that single photon exists. The solid confirmation is produced in this study by using three detectors. The 405 nm laser was pumped into the down-converted crystal and 810 nm two beams emitted like a cone. The first beam called G path went to the photon detector and the second traveled to the beam splitter. The second beam was split into two paths, T and R paths, and also went to the photon detectors. For collected the coincident data, the coincident circuit was used as the counting module. Using three detectors with the same laser source obtained the result that = 0.027561 ± 0.000515 which violate the classical inequality ≥ 1 by the 1888 standard deviation within 30 min of counting time. The result is better than previous study and the concrete confirmation of the single photon existence is completely proved.

Speaker: Mr Ratchanikorn Koomramyakul (Division of Physics, Mahidol Wittayanusorn School, Phutthamonthon, Nakhon Pathom 73170, Thailand)

9:00 AM Measurement of linear thermal expansion by using fiber optic displacement sensor method

Fiber optic displacement sensor (FODS) is demonstrated to probe the linear thermal expansion of materials. The device employs an intensity modulation technique which is based on comparing the transmitted light intensity against that of the launch light to provide information on the displacement between the probe and the target. Steel and Aluminum were used as the target. From the thermal expansion phenomena, material will expand when heated. As the displacement between the probe and the material was changed due to the thermal expansion, the intensity signal from reflected light was collected. Although, the displacement between the probe and target was slightly, it could still be detect by the proposal device. The measured linear expansion results are checked against the expected theoretical and the operation of this sensor was also compared with other techniques. Advantages of the proposed technique include non-contact measurement, economical set up and suitability for many applications and precise measurements.

Speaker: Mr Paradai Phanpanich (Department of Physics, Faculty of science, Mahidol university, 272 Rama 6 Road Ratchathewi Bangkok, 10400)

9:15 AM → 9:30 AM Environmental Physics, Atmospheric Physics, Geophysics and Renewable Energy

9:15 AM Theoretical Study of Charge Transport in Alternating Donor-Acceptor Complex Oligomers for Polymer Solar Cell Applications: Poly(3-hexylthiophene) Based Azole

In this research have been simulated geometrical structures, molecular orbital, charge transports and photophysics of complex alternating donor-acceptor oligomers using in photo-active layer of polymer solar cell applications. Poly(3-hexylthiophene) (P3HT) was selected as an electron donor, while different azole such as oxadiazole (OXD), triazole (TAZ) and thienothiadiazole (TD) were used as electron acceptors, resulting in donor-acceptor complex oligomers P3HT-OXD, P3HT-TAZ and P3HT-TD, respectively. The calculation was performed by using Gaussian 09W software package at density functional theory (DFT) level with B3LYP (Becke Three-parameters Lee–Yang–Parr) exchange correlation functional and 6-31G(d) basis sets. Simulation results obtained that energy levels HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) from all isolated electron acceptor molecules (OXD, TAZ and TD) are lower than that of the isolated electron donor (P3HT) indicating that all acceptors can withdraw electrons from the donor molecule. However, analyzing geometrical structure results were revealed that P3HT-OXD and P3HT-TD monomers reveal planarized structure, while TAZ unit from P3HT-TAZ molecule shows twisted conformer. Analyzing of molecular orbitals from complex oligomers were found that at LUMO level, electron transported from the donor to the acceptor unit was found from all complex oligomers but less for P3HT-TAZ due to large torsional angle between donor and acceptor units. Intramolecular charge transfer can be verified by Mulliken population analysis (Mulliken charge) on the acceptor unit. We obtained that OXD provides strongest electron withdrawing than others and polymer of P3HT-OXD can absorb wavelength of light well at 420 nm which is closed to maximum intensity range (around 550 nm) from solar spectrum compared to other (P3HT-TAZ = 371 nm, P3HT-TD = 3024 nm), indicating that OXD behaves as a good electron acceptor. We concluded that OXD provides appropriate characteristics of an electron acceptor unit for complex donor-acceptor using for polymer solar cell application.

Speaker: Dr Areefen Rassamesard (Division of Physics, Faculty of Science and Technology, Prince of Songkla Universtity, Pattani Campus, THAILAND 94000)

9:30 AM → 9:45 AM Photonics and Optoelectronics

9:30 AM Simulation of circular polarization filter in 1D chiral photonic crystal structure with defect using FDTD method: oblique incidence

The circular polarization filter is designed in 1-dimensional (1D) chiral photonic crystal structure with defect. In this simulation, the structure is composed of 10 pairs of periodic layers of high (AgGaS$_2$) and low (quartz) refractive index chiral materials with defect layer in the middle. By using finite-different time-domain (FDTD) method, the transmission spectrum from structure reveals the potential of selected right-/left- circular polarization filter for specific wavelength and the effect of oblique incidence on transmission spectrum is presented.

Speaker: Mr Prateep Pimsarn (Applied Optics Research Group, Department of Physics, Faculty of Science, Mahidol University, Bangkok, Thailand 10400)

9:45 AM → 10:45 AM Surface, Interface and Thin Films

9:45 AM Effect of Argon Pressure on the Structural and Optical Properties of RF-Sputtered ZnO Thin Films

The wide bandgap semiconducting oxide, ZnO is attractive for a range of optoelectronic devices due to its dual advantages of high optical transparency and electrical conductivity. In view of its applications, ZnO films have been grown by a variety of techniques and different methods of material engineering have been used to tailor its properties. In this study, we show the effect of varying oxygen partial pressure on the optical properties of rf-sputtered ZnO films. A set of films were obtained for varying argon pressures of 0.025, 0.03, 0.05, 0.075, and 0.1 mbar. The films were subsequently annealed at 400ºC in an oxygen atmosphere. X-ray diffraction and Raman spectra of the films confirmed the wurtzite structure and a good crystalline quality. The as-deposited films were strained and which relaxed after annealing. Atomic force microscopy was used to monitor the surface topography and the surface roughness before and after annealing. The reflectivity spectra of the films showed a decrease in the number of interference fringes with an increase in argon pressure. This is representative of the increase in thickness of the films. The values of the thickness, refractive index, absorption co-efficient and carrier concentration of the films for varying argon pressures are further determined spectroscopic from ellipsometry measurements by analysing the complex dielectric function (ε (E) = ε$_1$(E) + iε$_2$(E)) in the range of 0.5-5.5 eV and using appropriate optical models. The refractive index of the films decreases from 1.859 to 1.794 when the argon pressure is increased from 0.015 and 0.1 mbar. The bandgap is investigated by photoluminescence spectroscopy and did not exhibit any significant change with argon pressure. However, the bandgap of the as-deposited film showed a blueshift as compared to the annealed film. A widening of the optical bandgap is due to a high carrier concentration induced by non-stoichiometry and explained by the Burstein-Moss shift.

Speaker: Shyama Rath (Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok 10330, THAILAND; Department of Physics and Astrophysics, University of Delhi, Delhi-110007, INDIA)

10:15 AM Polysulfone Gas Separation Membrane: Effect of Evaporation Time on Morphology and Mechanical Strength

Preparing of polysulfone (PSF) gas separation membranes by dry/wet phase inversion technique were conducted in this work. The effect of evaporation time (ET) on the morphology, structure and gas separation performance of produced PSF membranes was investigated. The ET was varied for 0, 10, 30, 60, and 120 s. Morphology and structure of membrane samples were analyzed through the SEM micrograph and Carnoy version 2.0 software while the gas separation performance was evaluated in term of gas permeation. Mechanical strength in term of modulus was measured by DMTA. Results showed that the defect-free and dense top skin layer asymmetric membranes were produced. The top skin thickness was increased with an increment of ET from 0 to 120 s. However, solvent type was influenced to the skin layer thickness, as well. The CO2 and CH4 permeation rate decreased when ET was increased.

Speaker: Mr Chalad Yuenyao (Department of Physics, Faculty of Science, Prince of Songkla University, Hatyai, Songkhla, THAILAND 90112; Thailand Excellence Center in Physics (ThEP), Bangkok, THAILAND 10400)

10:30 AM Effect of growth parameters and gamma ray irradiation on luminescence properties of Eu-doped barium titanate thin films

Eu-doped BaTiO$_3$ thin films were deposited on quartz and borosilicate glass substrates by a sol-gel spin coating process. The films were grown with various growth parameters including film thickness, spinning speed, annealing time, annealing temperature and concentration of europium to evaluate their influence on film luminescent properties. We studied their luminescent properties using excitation wavelengths in a UV range. The electric-dipole transition $^5\mbox{D}_0\rightarrow^7\mbox{F}_2$ at about 615 nm and the magnetic transition $^5\mbox{D}_0\rightarrow ^7\mbox{F}_1$ transition at about 589 nm were observed. With an annealing temperature at 600$^{o}$C for 1 hr, the luminescent intensity of the films deposited on quartz increased with the number of layer deposited. Moreover, the luminescent intensity depended on the spinning speed which was related to the varying film thickness. The luminescent intensity was higher as the thickness increased according to lowering spin speed. The annealing time was varied in the range of 20 min to 80 min and we found that the film annealed for 40 min yielded the best luminescent intensity. Further annealing time and annealing temperature above 600$^{\circ}$C caused the luminescent intensity to decrease. This was due to the fact that the longer annealing time and the higher temperatures caused a reduction of europium concentration, resulting in a rapid quenching of Eu$^{3+}$. Also, we found that the luminescence intensity increased as the Eu concentration increased from 3 mol% to 7 mol% and dropped above 7 mol%. Furthermore, the post-synthesis parameter were also analyzed. The films were gamma irradiated with doses of 10, 20, 30 and 40 kGy, and their emission spectra were compared with those of non-irradiated films. The emission maxima in the spectra decreased after gamma exposure doses higher than 20 kGy. The decrease of the emission peak intensities became most apparent in the case of the irradiated film at 30 kGy, the reduction of the emission was 17.2 % for the 615 nm peak wavelength. Gamma ray doses higher than 30 kGy did not cause any further reduction the emission peak intensities.

Speaker: Mr Tanapat Ratchatorn (Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok, THAILAND 10330)

10:45 AM → 11:00 AM Break

10:45 AM → 11:00 AM Break

10:45 AM → 11:00 AM Break

11:00 AM → 12:00 PM Plenary: Black silicon and the quest for intermediate band semiconductors

11:00 AM Black silicon and the quest for intermediate band semiconductors

Shining intense, ultrashort laser pulses on the surface of a crystalline silicon wafer drastically changes the optical, material and electronic properties of the wafer. The resulting textured surface is highly absorbing and looks black to the eye. The properties of this 'black silicon' make it useful for a wide range of commercial devices. In particular, we have been able to fabricate highly-sensitive PIN photodetectors using this material. The sensitivity extends to wavelengths of 1600 nm making them particularly useful for applications in communications and remote sensing.

Speaker: Prof. Eric MAZUR (Harvard University, USA)

12:00 PM → 1:00 PM Lunch

1:00 PM → 3:15 PM Astronomy, Astrophysics and Cosmology (Sponsored by NARIT)

1:00 PM Influence of Magnetospheric Plasma on Aurora at Magnetic Footprints of Io

Io magnetic footprint (IFP) is a result of interaction between Jovain magnetosphere and Io. Due to Jupiter’s fast rotation in comparison with Io, magnetospheric plasmas collide with atmospheric particles of Io at high speeds. Therefore the interaction region expands into an extended area behind Io. As a result, aurora spot is extended into a tail-like structure. This research study factors that affect variability of interaction between Jupiter’s magnetosphere and Io, which causes the variation of magnetic footprint’s brightness for different positions of the Io in Jupiter’s magnetosphere. Io’s position is indicated by System III longitude. Observations of Io magnetic footprints in this study had been conducted via the Space Telescope Imaging Spectrograph (STIS) and Advanced Camera for Surveys (ACS) instruments along with the Hubble Space Telescope (HST). We compare the magnetic footprint’s brightness from observed data with fitted data since 1999 to 2007. This study found that the brightness is controlled by several factors such as the variation of plasma density in the vicinity of Io, the magnetic field asymmetry, including the duration of volcanic eruption on Io.

Speaker: Ms Tatphicha Promfu (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand)

1:15 PM Angular Extension of Io Magnetic Footprint in Corresponding to Volcanic Activity on Io

FUV images of Jupiter’s auroral region have been taken since the early observational era of the Hubble Space Telescope (HST). In the vicinity of the main auroral oval, an emission spot was detected and appeared to be evidence of electromagnetic interaction between Jupiter’s magnetospheric plasma and Io’s atmosphere. In previous works, the brightness of this emission, which is called Io’s auroral magnetic footprint, reveals strong correlation with Io’s location in Jupiter’s system III longitude. In 2007, with HST’s Advanced Camera for Surveys (ACS), the magnetic footprints of Io were observed, while the volcanoes on Io concurrently erupted. In this study, the magnetic footprint emissions were chosen regarding the variation of Io’s locations. Detailed analysis of the angular extension of Io’s magnetic footprint was presented. Based on the complexity of angular extension due to the multiplicity of the footprint spots, the connection between angular extensions of Io magnetic footprints and the volcanic activity reveals some correlation. This result suggests the possible influence of the picked-up current on the extension of the interaction region between precipitating electrons and Jupiter’s ionospheric particles.

Speaker: Dr Suwicha Wannawichian (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand)

1:30 PM Variations in the Neutron Time Delay Distribution at the Princess Sirindhorn Neutron Monitor

The Princess Sirindhorn Neutron Monitor (PSNM) has operated since late 2007 at the summit of Doi Inthanon, Thailand's highest mountain, in Chiang Mai province. PSNM records the flux of galactic cosmic rays (GCRs) impinging on Earth's atmosphere, as well as the GCR flux variations with time due to solar activity. PSNM has the world's highest cosmic ray vertical cutoff rigidity (momentum per charge) for a fixed station, 16.8 GV. The recorded count rate comes from the detection of nuclear disintegrations of $^{10}$B in BF$_3$-filled proportional counters, mostly due to interactions with neutrons evaporated from the Pb producer when hit by a cosmic-ray-generated atmospheric shower particle (usually a neutron). In addition to monitoring the count rate, the PSNM electronics can record neutron time delays (the time between one count and the next) in each counter. An analysis of time delay histograms shows an exponential tail at long times (> 1 ms) that can be interpreted in terms of chance coincidences, i.e., counts associated with independent atmospheric particles. Shorter time delays, however, are dominated by counts originating from the same interaction between a Pb nucleus and an atmospheric particle. This component contains information about the energy distribution of atmospheric shower particles and, thus, about the GCR energy spectrum as well, and its variations with time are of interest. In this work we analyze neutron time delay histograms from PSNM and derive the leader fraction $L$, i.e., the fraction of neutron counts not associated with a previous count in the same counter from the same nuclear interaction. We report on variations of $L$ with time, their dependence on atmospheric depth and water vapor pressure, and show that, after correcting for these environmental effects, the remaining variations are of interplanetary origin. This represents a qualitatively new type of observation in the 60-year history of neutron monitor science.

Speaker: Dr Alejandro Sáiz (Department of Physics, Faculty of Science, Mahidol University, Bangkok 10400 Thailand)

1:45 PM Observations and Monte Carlo Simulation of the Princess Sirindhorn Neutron Monitor at a Vertical Cutoff Rigidity of 16.8 GV

Neutron monitors (NMs) are large ground-based instruments for precise time tracking of the variations in the Galactic cosmic ray (GCR) flux at GeV-range. NMs are counting the secondary particles (mostly neutrons) issued from the interaction of the cosmic rays in the atmosphere. The sensitivity to GCR variations depends on the geomagnetic cutoff at the location of measurement. Since late 2007, the Princess Sirindhorn Neutron Monitor (PSNM), at the summit of Doi Inthanon, Thailand's highest mountain (2565 m altitude), records the flux of galactic cosmic rays with the world’s highest vertical cutoff rigidity for a fixed station, 16.8 GV. We have developed Monte Carlo simulations of cosmic ray interactions in the atmosphere and in PSNM, and trace cosmic ray trajectories through Earth's magnetic field to model the cosmic ray suppression at low rigidity at the location of PSNM. The simulation shows a fairly good agreement with the data and the variations of the GCR spectrum, such as the solar modulation, can be investigated for the first time with a fixed NM at high rigidity. That expands the range in energy of the worldwide NM network's sensitivity.

Speaker: Dr Pierre-Simon Mangeard (National Astronomical Research Institute of Thailand, Chiang Mai 50200, Thailand)

2:00 PM Simulations of Polar-Region Atmospheric Ionization Induced by the Large Solar Storm on January 20, 2005

Ionizing radiation in the Earth’s troposphere is mainly due to Galactic cosmic rays, high-energy particles from outside the Solar System. Typical solar energetic particles do not have enough energy to penetrate to aircraft or cloud altitudes. However, occasionally solar storms can produce relativistic ions with such enormous intensity that their ionization effect in the Earth’s lower atmosphere is significant. One of the largest solar storms ever observed occurred on January 20, 2005, which resulted in very large increases in the count rates of ground-based particle detectors, especially near the polar regions. We use data recorded by two neutron monitor stations located near the magnetic south pole (McMurdo) and north pole (Inuvik) to reconstruct particle energy spectra at the top of the atmosphere for each location as a function of time. We create realistic atmospheric models from measured meteorological data and use them along with the reconstructed particle flux to perform Monte Carlo simulations of particle-air interactions. We calculate atmospheric ionization at different altitudes and times during the 2005 solar storm for each location. The real-time ionization profiles obtained will be useful for studying aircrew health effects, correlations with cloud formation, and climate change.

Speaker: Dr Warit Mitthumsiri (Department of Physics, Faculty of Science, Mahidol University, Bangkok 10400 Thailand)

2:15 PM Overcoming the Seeing Limitations at 2.4-m Thai National Telescope with Lucky Imaging Technique

Resolving power of large telescopes is limited by seeing condition, the blurring due to the Earth's atmospheric turbulence. This limits the capability of large telescopes, including the 2.4-m diameter Thai National Observatory (TNO) in Chiang Mai, Thailand, from reaching its fullest resolving power. We present an effort to overcome this limitation through the ‘Lucky Imaging' technique, which is done by taking large number of short (e.g., 0.01 second) exposures to “freeze" the atmospheric turbulence, and select the least atmospherically distorted images to combine into a final image with high signal-to-noise ratio. We obtain R-band images of Messier 15 and 79 (M15 and M79) from the TNO during December 2014. The objects are chosen to represent high-density star field suitable for determining the resolving power of the final image. We took 240 and 502 images of M15 and M79, respectively, and selected 1% of images with best quality to combine into final images. We measured the full width at half maximum flux (FWHM) of the final star images and found that we can obtain FWHM as low as 1.17 and 1.25 arcsec, for M15 and M79, respectively. This represents a ~20% improvement to the resolution from the original 1.66 and 1.48 arcsec FWHM for M15 and M79, despite the average seeing conditions and moderate airmass of 1.2 - 1.8. This experiment suggests that the TNO is capable of high-resolution imaging of relatively faint objects such as star clusters through lucky imaging technique if data is acquired at the best seeing and highest elevation possible.

Speaker: Rattanawadee Tekavong (Department of Physics, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok, Thailand 10140)

2:30 PM Can Dark Matter be a Bose-Einstein Condensate?

We consider the possibility that the dark matter, which is required to explain the dynamics of the neutral hydrogen clouds at large distances from the galactic center, could be in the form of a Bose-Einstein condensate. To study the condensate we use the non-relativistic Gross-Pitaevskii equation. By introducing the Madelung representation of the wave function, we formulate the dynamics of the system in terms of the continuity equation and of the hydrodynamic Euler equations. Hence dark matter can be described as a non-relativistic, Newtonian Bose-Einstein gravitational condensate gas, whose density and pressure are related by a barotropic equation of state. In the case of a condensate with quartic non-linearity, the equation of state is polytropic with index n=1. To test the validity of the model we fit the Newtonian tangential velocity equation of the model with a sample of rotation curves of low surface brightness and dwarf galaxies, respectively. We find a very good agreement between the theoretical rotation curves and the observational data for the low surface brightness galaxies. The deflection of photons passing through the dark matter halos is also analyzed, and the bending angle of light is computed. The bending angle obtained for the Bose-Einstein condensate is larger than that predicted by standard general relativistic and dark matter models. Therefore the study of the light deflection by galaxies and the gravitational lensing could discriminate between the Bose-Einstein condensate dark matter model and other dark matter models.

Speaker: Dr Tiberiu Harko (Department of Mathematics, University College London, Gower Street, London WC1E 6BT, United Kingdom)

2:45 PM Lumpy Cosmic Strings

We outline a model of abelian-Higgs strings with variable scalar and vector core radii. In general, the functions determining the time and position-dependent core widths may be expressed as arbitrary left or right movers, of which the usual constant values are a particular solution. In this case the string may carry momentum, even if the embedding of its central axis remains fixed, and the resulting objects resemble "necklaces". Some possible astrophysical applications, such as lumpy strings as engines for anomalous gamma ray bursts, are also discussed.

Speaker: Dr Matthew Lake (The Institute for Fundamental Study, Naresuan University, Phitsanulok 65000, Thailand)

3:00 PM Magnetic Field Line Random Walk in Isotropic Turbulence at Very High Kubo Number

Most of the field line random walk (FLRW) theories proposed in the past were strongly influenced by studies of the limit of weak fluctuations. In this limit, the behavior of the FLRW can be characterized by the Kubo number $R=(b/B_0)(\ell_\parallel/\ell_\perp)$, where $b$ is the root mean squared fluctuation, $\ell_\parallel$ and $\ell_\perp$ are turbulence coherence scales parallel and perpendicular to the mean field $B_0$, respectively. In the case of $R \ll 1$, a quasi-1D limit, all theories and computer simulations agree that the FLRW is quasilinear. In the case of $R \gg 1$, a quasi-2D limit, there are strong trapping effects in which some field lines are trapped in topological structures. Then the Corrsin-based theory is less accurate. To study the FLRW at high $R$, while avoiding the topological effects in the quasi-2D limit at high $R$, we examine different versions of Corrsin-based theory in the limit $R \to \infty$ by taking $B0 \to 0$ for finite $b$ instead of taking $\ell_\parallel/\ell_\perp \to \infty$. Naturally, with $B_0 = 0$, the FLRW is completely isotropic. We test the theory by performing computer simulations of the FLRW. All Corrsin-based theoretical results agree with simulation results for the FLRW at $B_0=0$ ($R=\infty$). We conclude that the applicability of Corrsin-based theories is limited not by high $R$, but by quasi-two-dimensionality.

Speaker: Wirin Sonsrettee (Faculty of Engineering and Technology, Panyapiwat Institute of Management, Nonthaburi 11120, Thailand)

1:00 PM → 3:15 PM Ion and Plasma Physics

1:00 PM Development of cost effective plasma technology at university of Malaya

Recently, the development of atmospheric pressure non-thermal plasma has been the research interest of many research groups world wide. This is because it is now realized that there is a need to develope cost effective plasma technology so that it can be more widely used in industry. The atmospheric pressure plasma devices being considered include the glow discharge and the dielectric barrier discharge. Besides reducing cost by working with atmospheric pressure, another cost factor is the power supply. Currently, RF or microwave sources are commonly used in industry to power the plasma system. For the generation of non-thermal plasmas, it is suitable to use the 50 Hz household supply to power the glow discharge or the dielectric barrier discharge. A step-up transformer can be used to provide a discharge voltage higher than the 240 V peak voltage supply from the mains.

Speaker: Chiow San Wong (Plasma Technology Research Centre Physics Department, University of Malaya 50603 Kuala Lumpur, Malaysia)

1:30 PM Metal nanoparticles synthesis using atmospheric pressure micro discharge jet

Metal nanoparticles (NPs) due to their size and shape, have unique attributes that differ from their macrosized counterparts. These attributes contributed to an ever-growing list of applications, from medicine to electronics. The challenge is not only to create the nanoscale sizes but also to keep the metal NPs dispersed without agglomeration. Conventional methods to synthesize the NPs include the physical (e.g. evaporation-condensation, laser ablation) and chemical (via chemical reducing and capping agents) approaches. An alternative method is to use a specially configured atmospheric pressure micro discharge jet to produce NPs without the addition of reducing and capping agents. In this case, the micro discharge jet is itself the reducing agent, hence, making it environmentally friendly. The synthesis process is quite rapid (within minutes) and no heating is required.

Speaker: O.H. Chin (Plasma Technology Research Centre, Physics Department, University of Malaya 50603 Kuala Lumpur, Malaysia)

2:00 PM Generation of ozone in Dielectric Barrier Discharge and Its Application for Water Treatment

A dielectric barrier discharge (DBD) type ozone generator was designed with oxygen /air as a feed gas. The discharge was generated by using high voltage power supply operating at line frequency (50Hz). The effect of gas flow rate and applied voltage on the concentration of the ozone was investigated. The flow rate was varied from 1 lit/min to 5 lit/ min for electrode area A=143.56 cm${}^2$ and 107.67cm${}^2$ and two values of gap space between electrodes d= 1mm and 2 mm. The applied voltage was varied from (5- 18 kV) for the same gap space and electrode area. It was found that the concentration of ozone produced increases with increasing voltage, and decreases with increasing flow rate for fixed applied voltage. The ozone thus produced was used for the treatment of water. Various physical, chemical and micro-biological parameters were analyzed on the samples before and after the treatment by ozone. Our results indicated that ozone does not alter the physical properties significantly, namely pH, conductivity and turbidity of water. However, the treatment leads to a remarkable reduction in the number of fecal coliform in the samples of water.

Speaker: Prof. Deepak Prasad Subedi (Department of Natural Sciences, School of Science, Kathmandu University, Dhulikhel, Nepal)

2:30 PM New solitonic, periodic and chaotic behaviors of ion acoustic waves in a nonextensive electron-positron-ion plasma

Solitonic, periodic and chaotic behaviors of ion acoustic waves in an unmagnetized plasma with q-nonextensive electrons and positrons are investigated applying the bifurcation theory of planar dynamical systems. Model equations are transformed to a planar dynamical system using a traveling wave transformation. Then by using the bifurcations of phase portraits of this planar dynamical system, we have established that our model has solitary wave solutions and periodic wave solutions. We have obtained new analytical solutions for solitary and periodic waves depending on the parameters. Considering an external periodic perturbation, chaotic behavior of ion acoustic waves has been presented. It is shown that the speed of the traveling wave (v) and other parameters play crucial roles in qualitative changes of the dynamical system and chaotic behavior of the system.

Speaker: Prof. Prasanta Chatterjee (Department of Mathematics, Siksha Bhavana, Visva Bharati University, Santiniketan-731235, Birbhum, India)

2:45 PM Improvement of RD31 rice seed germination using DBD plasma treatment

Effects of atmospheric plasma treatment on RD31 rice seed germination are studied. The seeds are treated with 5 mW of plasma for 10 sec. It is found that plasma treatments have positive effects on seed germination and seeding growth at the early stage. The germination rate is found to improve by 25% compared to non-treated seeds. In addition, the better quality of sprouts is obtained. It is found that after 15 days, the roots’ length and weight of treated seeds is increased by 10% and 20%, respectively, compared to non-treated seeds. In addition, the trunks’ length and weight are increased by 15% and 20%, respectively.

Speaker: Ms Tipwimol Traikool (Thammasat University)

Slides Plasma_and_Fusion_Research_Unit.pdf Plasma_and_Fusion_Research_Unit.pptx

3:00 PM Development of 3.3 kJ Small Plasma Focus for Medical Radioisotopes Production: Preliminary results

PET scan is a medical imaging device for effective cancer diagnosis. It use medical radioisotopes such as 18-F. Since 18-F has short half-life, on site production is inevitable. Normally, cyclotron is used in the big hospital to produce 18-F. Plasma focus, a much cheaper and compact system, is an alternative device for 18-F production. The plasma focus can generate energetic particles which have enough energy for nuclear reaction to generate radio-isotopes. The main part of plasma focus device is consist of vacuum chamber, coaxial electrode, high voltage capacitor, high voltage power supply, spark gap and trigger. The Lee model and current waveform of RLC circuit is used to design the 3.3 kJ plasma focus. The cathode and anode radius are optimized to be 1.25 and 2.50 cm, respectively, where their length are the same as 22.50 cm. The model show that when maximum current of 167 kA is pinched within 13.4 ns, plasma temperature is risen to be 4.08$\times$106K. To verify the Lee model, electric current oscillation in RLC circuit is measured under short circuit, when inductance L, resistor R and capacitor C are 125 nH, 20 m$\Omega$ and 30 $\mu$F, respectively.

Speaker: Mr Arlee Tamman (School of Science, Walailak University, Nakhon Si Thammarat 80161, THAILAND)

1:00 PM → 4:30 PM ThEP

1:00 PM → 4:30 PM Senior project competition

1:00 PM → 4:30 PM Poster-3

1:00 PM CdS/CdSe Co-sensitized on Different TiO${}_2$ Morphologies and its Application to Quantum Dot-sensitized Solar Cells (QDSSCs)

With power conversion efficiency in continuous growth, quantum dot-sensitized solar cells (QDSSCs) are recently under high interest; however there is no such perfect cell yet developed for these devices. As the fundamental model of QDSSCs, the morphology of the TiO${}_2$ photoanode plays an important role in photovoltaic performance. Herein, the TiO${}_2$ films based on nanorods (TiR) and arrays of nanorods having flower blossom-like formations on their surface (FTiR) were synthesized by one- and double-step hydrothermal process, respectively. The CdS and CdSe co-sensitized on TiR and FTiR were deposited by using the successive ion layer absorption and reaction (SILAR) and chemical bath deposition (CBD). To study conversion efficiency, FTiR after CdS/CdSe co-sensitized has shown the improving conversion efficiency (η) compared with TiR photoanode. The efficiencies of CdS/CdSe co-sensitized loading were 0.703% and 0.022% for FTiR and TiR photoanodes, respectively. This study revealed a synergistically beneficial effect (enhanced solar-to-current conversion) of the flower blossom-like formations on the nanorods in CdS/CdSe co-sensitized solar cells.

Speaker: Ms Nattha Buatong (Department of Physics, Faculty of Science, Kasetsart University, Bangkok, THAILAND 10900)

1:00 PM Characteristics of AZO/Ag/AZO Tri-layer Film by RF-sputtering

Al-doped ZnO (AZO)/Ag/AZO tri-layer thin films were deposited on glass substrate by RF-sputtering. The thickness of AZO layer at the top and bottom of the film was varied at 35, 50 and 90 nm and the thickness of Ag layer was fixed at 62 nm. XRD result confirms that all AZO/Ag/AZO tri-layer films were composed of ZnO (HCP) phase in (002) direction and Ag (FCC) phase in (111) and (200) directions. Intensity of ZnO phase was directly increased with increasing AZO layer-thickness. The electrical resistance of the tri-layer film was decreased with increasing the AZO-thickness. The transmittance pattern of the film was significantly depended on the AZO thickness. Tri-layer film with AZO thickness of 35, 50 and 90 nm showed the average transmittance of 24, 28 and 15% in the visible region, respectively and also displayed the maximum transmittance of 50%, 35% and 28% at wavelength of 400, 500 and 700 nm, respectively. The results implied that transmittance pattern, transmission region and wavelength of maximum transmission of AZO/Ag/AZO tri-layer film can be manipulated by the AZO layer thickness.

Speaker: Mr Yuttapichai Khummanee (Department of Physics, Faculty of Science, Kasetsart University, Bangkok, THAILAND 10900)

1:00 PM Characterization and Analyzation of Chitosan from Paphia Undulate Shell

This work aims at characterizing the physical and chemical properties of chitosan which extract from the Paphia Undulate Shell. The physical and chemical properties have been also discussed in detail which Fourier Transform Infrared Spectroscopy (FTIR), Energy Dispersive X-Ray Fluorescence (EDXRF) and X-Ray Diffraction (XRD), respectively. The result of the XRD pattern indicated the sample has amorphous-crystalline structure and FTIR results confirmed the formation of intermolecular hydrogen bonding between the amino and hydroxyl groups of the sample which corresponding with the result of. the EDXRF, which report the highest concentration of chemical composition is CHO.

Speaker: Wichian Siriprom (Faculty of Science at Si Racha, Kasetsart University, Si Racha campus, Chonburi, THAILAND 20230)

1:00 PM Characterization and Magnetic Properties of Fe-doped MgO Nanoparticles

Fe-doped MgO (Mg${}_{1-x}$Fe${}_x$O, $x$ = 0, 0.05, and 0.07) nanoparticles synthesized by the polymer pyrolysis method were investigated. The precursors were calcined at temperatures of 700 ${}^{\circ}$C for 3 hours in air to obtain the phase of MgO. X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray absorption near edge spectroscopy (XANES), and vibrating sample magnetometry (VSM) were used to characterize phase, morphology, valence states and magnetic properties of the samples. The samples had a phase of the face centered cubic with crystallite sizes of 25 $\pm$ 2 nm. The result of XANES spectra showed that the Fe${}^{3+}$ exists in the samples. The weak ferromagnetic (FM) behavior at room temperature (RT) is observed for all Mg${}_{1-x}$Fe${}_x$O samples with a maximum magnetization of 1.30 emu/g for $x$ = 0.07. The origin of ferromagnetism of the prepared Mg${}_{1-x}$Fe${}_x$O samples was discussed.

Speaker: Dr Sumalin Phokha (Department of Physics, Faculty of Science, Udon Thani Rajabhat University, Udon Thani, THAILAND 41000)

1:00 PM Characterization of Ce${}_{1-x}$Pr${}_x$O${}_2$ was Synthesized by a Co-precipitate Method.

Ce${}_{1-x}$Pr${}_x$O${}_2$ ($x$ = 0, 5, 10, 15 and 20) was synthesized by a co-precipitate method. The crystallization temperature started around 300 ${}^{\circ}$C. After calcination at 800 ${}^{\circ}$C for 8 hr, the grains size of undoped sample was about 69 nm. Doping Pr into CeO${}_2$ resulted-in the reduction to grains size. The smallest grains size of 40 nm was observed for Ce${}_{0.8}$Pr${}_{0.2}$O${}_2$. Incorporation of Pr into ceria lattice was confirmed from the increased in lattice parameter and oxygen vacancy. Moreover the area intensity ratio of ceria main peak over the vacancy peak was reduced with the increasing dopant. Ce${}_{0.8}$Pr${}_{0.2}$O${}_2$ have the highest conductivity of 0.01 S/cm above 600 $^{\circ}$C.

Speaker: Mr Pilan Ngiewlay (Department of Material Science and Nanotechnology, Faculty of Science, Khon Kaen University, Khon Kaen, THAILAND 40002)

1:00 PM Comparative Study of Effects of Metal Oxides Modifications on Properties of Pb(Mg${}_{1/3}$Nb${}_{2/3}$)${}_{0.9}$Ti${}_{0.1}$O${}_3$ Ceramics

This work studies effects of metal oxides (MO; M = Zn${}^{2+}$, Cu${}^{+}$ and Ni${}^{2+}$) modifications on phase, microstructure, dielectric, ferroelectric and electrostrictive properties of Pb(Mg${}_{1/3}$Nb${}_{2/3}$)${}_{0.9}$Ti${}_{0.1}$O$_3$ (PMNT) ceramics. Different contents of MO (2 and 4 mol%) were modified into PMNT ceramics. The ceramics with the density about 7.80 g/cm${}^3$ were prepared. XRD pattern and lattice parameters of the PMNT ceramic did not change with the MO modifications. An average grain size of the PMNT ceramic increased with the ZnO and NiO modifications. The grain size was extremely enlarged with the CuO modification. A maximum dielectric constant of the PMNT ceramic was enhanced with 2 mol% ZnO and 2 mol% CuO modifications while 2 mol% NiO modification resulted in a reduction of the maximum dielectric constant. A temperature of a maximum dielectric constant (Tmax) of the PMNT ceramic shifted toward a higher temperature with 2 mol% ZnO modification. It was decreased with 2 mol% CuO and 2 mol% NiO modifications. Polarization-electric field curve of the PMNT ceramic was well developed with a higher remnant polarization (Pr) by 4 mol% ZnO modification while it was slimmer with a lower Pr by the NiO modification. A maximum strain and an electrostrictive coefficient of the PMNT ceramic were enhanced with 2 mol% ZnO and 2 mol% CuO modifications.

Speaker: Dr Methee Promsawat (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai, THAILAND 50200; Materials Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai, THAILAND 50200)

Poster Poster-SPC2015-Methee-211.pdf

1:00 PM Controlled Growth of ZnO Nanostructures in Hydrothermal Process on ZnO Seeds Layer Synthesized with Different Precursor Concentrations

Zinc oxide (ZnO) nanorods and nanosheets were grown via hydrothermal process on ZnO seed layers synthesized by spin-coating technique on silicon and glass substrates with different precursor concentrations of zinc acetate dihydrate. The concentrations of zinc acetate dihydrate in solution were varied from 6 mM to 500 mM. The ZnO seed layers, ZnO nanorods, and ZnO nanosheets were characterized by field-emission scanning electron microscope (FESEM) and X-rays diffractometer (XRD) to study morphology and crystallographic structure, respectively. The results showed that particle size and diffraction pattern of ZnO seed layers changed with various precursor concentration. Moreover, different precursor concentration affected the change of ZnO morphology from nanorods to nanosheets.

Speaker: Mr Nontakoch Siriphongsapak (Department of Physics, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok, THAILAND 10140.)

1:00 PM Crystallization and Dielectric Properties of Nd$^{3+}$ Doped Ferroelectric Glass-Ceramics in the Na$_2$O-BaO-Nb$_2$O$_5$-SiO$_2$ System

Ferroelectric glass-ceramics of the Na${}_2$O-BaO-Nb${}_2$O${}_5$-SiO${}_2$ system were obtained from controlled crystallization process performed on the parent glass of composition 20Na${}_2$O-10BaO-30Nb${}_2$O${}_5$-40SiO${}_2$. Nd${}_2$O${}_3$ doping content was varied in the range 0, 0.1 and 0.5 mol%. The glass samples were prepared via a conventional melting method at 1500 $^{\circ}$C in the platinum crucible for 2 hr following by splashed-quenching on the stainless steel plate. Thermal properties of the as-quenched sample were studied by DTA/TG technique and the results showed the possible crystallization peak at 740 $^{\circ}$C and this was selected as the treatment temperature. Heat treatment process was employed for production of glass-ceramic which is performed in the electrical furnace at selected temperature. The obtained glass-ceramic specimens were investigated in terms of the crystalline phase formation, volume fraction, bulk density and dielectric properties. The results of phase identification using XRD revealed that NaNbO${}_3$ and Ba${}_2$NaNb${}_5$O${}_{15}$ were the dominant crystalline phases for all doped samples. The volume fractions of the crystallites are noticeably increased with the Nd${}_2$O${}_3$ content. Bulk densities of the glass-ceramic samples are higher than that of the related as-quenched glass. The dielectric constants measured at room temperature at various frequencies for doped glass-ceramics seemed to be affected by the presence of Nd$^{3+}$ ion.

Speaker: Mr Paitoon Boonsong (Advanced Ceramics Laboratory, Ubon Ratchathani University, Ubon Ratchathani, THAILAND 34190)

1:00 PM Dielectric Properties of 0-3 Barium Zirconate Titanate˗Portland Cement Composites at 40% BZT Content with Carbon Addition

The 0-3 barium zirconate titanate˗portland cement composites with carbon addition which are expected to find application in civil engineering. The barium zirconate titanate, portland cement and carbon powder were fabricated using 425 µm barium zirconate titanate particle size at 40% by volume and varying carbon addition at 0.3-2% by volume. The composites were then cured at 60 ºC for 3 days before measurements. The dielectric constant and the dielectric loss at room temperature and various frequencies of the barium zirconate titanate˗portland cement composites with different carbon contents were investigated. The results show that the dielectric constant of composites was found to increase as carbon content increases, and that the dielectric constant was increase to the value of $\approx$310 for a carbon content of 2%.

Speaker: Dr Ruamporn Potong (Division of Physics, Faculty of Science and Technology, Rajamangala University of Technology Thanyaburi, Pathum Thani, THAILAND 12110)

1:00 PM Education fuel pellets made from cassava and coffee grounds.

The purpose of this research is to study the biomass fuel pellets. With cold compressed techniques high pressure. The main raw material used in the experiment are cassava and coffee grounds. Cassava was crushed and coffee grounds is baked and gliding grinded and sieved in the grain size of a 300 - 2000 μm. The samples were mixed with cassava and coffee grounds ratio of 10: 0, 9: 1, 8: 2, 7: 3, 5: 5, 7: 3 and 0:10 and compressed with a compression ratio of 5 , 10 and 15 tons/cm2. The cassava flued pellets sample were studied the properties of calorific value and compressive stregh. Experimental results on the cassava and coffee grounds to test the calorific value with a bomb Calorimeter is 3571.40 and 5236.70 cal / g. Keywords: Cassava, coffee grounds, fuel pellets , Compressive strength

Speaker: Mrs Kamonrat Wongsamat (Department of Physics, Faculty of Science, Ubon Ratchathani University)

1:00 PM Effect of Annealing in Reducing Atmosphere on Dielectric Properties of CaCu${}_3$Ti${}_4$O${}_{12}$/CaTiO${}_3$ Composites

The influence of annealing in Ar on the dielectric properties of CaCu${}_3$Ti${}_4$O${}_{12}$/CaTiO${}_3$ (CCTO/CTO) composites prepared by a solid state reaction method was studied. The phase composition and the microstructure were characterized by X-ray diffraction and scanning electron microscope with energy dispersive X-ray spectrometry, respectively. High dielectric permittivity values (2300$-$3000) with low loss tangent (0.01$-$0.03) at 1 kHz and room temperature were achieved in the CCTO/CTO composites. The dielectric permittivity was nearly independent on frequency in the range of 100$-$100000 Hz. Interestingly, the dielectric permittivity of the CCTO/CTO composites was largely reduced by annealing the sample in Ar atmosphere; while the low-frequency loss tangent value was largely increased. These results indicated to the decrease in the total resistance of the internal interfaces, i.e., CCTO-CCTO and CCTO-CTO interfaces. The dielectric behavior of the CCTO/CTO composites can be well explained based on the Maxwell-Wagner polarization at the internal interfaces.

Speaker: Ms Theeranuch Nachaithong (Materials Science and Nanotechnology Program, Faculty of Science, Khon Kaen University, Khon Kaen, THAILAND 40002)

1:00 PM Effect of Annealing on Magnetic Properties of SrTi${}_{1-x}$Co${}_x$O${}_3$ Nanoparticles Prepared by Hydrothermal Method

Co-doped SrTiO${}_3$ (SrTi${}_{1-x}$Co${}_x$O${}_3$) ($x$=0, 0.05, 0.1 and 0.15) nanopowders were synthesized by hydrothermal method. Their morphology and structure were studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). Magnetic properties were measured at room temperature using vibrating sample magnetometer (VSM). All samples show the major phase of a perovskite structure and the nanopowders consist of cubic-like particles with particle sizes in the range of 60- 120 nm. As-synthesized samples exhibit paramagnetic behavior and display the completed saturation ferromagnetic for samples annealed in Argon atmosphere at 800 ${}^{\circ}$C for 3 h. The ferromagnetic behavior in the annealed sample with $x$ = 0.15 is due to the impurity phase of CoO. However, for annealed samples with $x$ = 0.05 and 0.1, the observed ferromagnetic behavior is originated from the F-center mechanism. The saturation magnetization of annealed samples with $x$ = 0.05 and 0.1 are 0.048 and 1.080 emu/g, respectively.

Speaker: Mr Attaphol Karaphun (Department of Material Science and Nanotechnology, Faculty of Science, Khon Kaen University, Khon Kaen, THAILAND 40002)

1:00 PM Effect of Annealing Temperature on the Magnetic Properties of Fe Doped SrTiO${}_3$ Nanopapicles

SrTi${}_{0.90}$Fe${}_{0.10}$O${}_3$ nanoparticles were synthesized by hydrothermal method. SrTi${}_{0.90}$Fe${}_{0.10}$O${}_3$ samples were annealed at 500, 600 and 700${}^{\circ}$C in Ar. X-ray diffraction (XRD) results indicate a perovskite structure of all samples. TEM image shows SrTi${}_{0.95}$Fe${}_{0.05}$O${}_3$ nanoparticles of a cubic shape with an average size of 64.7 nm. X-ray absorption spectroscopy (XAS) was used to study the absorption of SrTi${}_{0.90}$Fe${}_{0.10}$O${}_3$ with various formal valences. The results show that Fe with oxidation states of Fe${}^{2+}$ and Fe${}^{3+}$ are presented in sample. Magnetic properties were measured using vibrating sample magnetometer (VSM). SrTi${}_{0.90}$Fe${}_{0.10}$O${}_3$ exhibits paramagnetic behavior. However, It is found that annealed SrTi${}_{0.95}$Fe${}_{0.05}$O${}_3$ in Ar can increase more oxygen vacancies in the structure causing the F-centre exchange (FCE) coupling interaction of metallic ions resulting in ferromagnetic with the maximum magnetization value of 2.24 emu/g for sample annealed at 700 ${}^{\circ}$C.

Speaker: Mr Likkhasit Wannasen (Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen, 40002, Thailand)

1:00 PM Effect of Eu$^{3+}$ Concentration on Crystallization and Luminescence Properties of CaO-MgO-Al$_2$O$_3$-SiO$_2$-ZnO Glass-Ceramics

Eu$^{3+}$-doped glass-ceramics were prepared in the system CaO-MgO-Al$_2$O$_3$-ZnO-SiO$_2$. Crystallization and luminescence properties of the glass-ceramics were studies by XRD, SEM, and fluorescence spectroscopy. After the heat treatment at the appropriated conditions, the crystalline phase found in the glass-ceramics was diopside (CaMg(SiO$_3$)$_2$) and Mg(Si$_2$O$_6$). There was no pronounced effect on the phase type due to presence of the Eu$^{3+}$ impurity. Participation of the doping content slightly altered the glass-ceramics microstructure. However, the fluorescence spectra determined from glass-ceramics with addition of Eu$^{3+}$ ions have shown the involvement of the diopside phase during phosphorescence process. With aided by Eu$^{3+}$ ions, a much stronger emission spectra was observed comparing to that of the corresponding glass. Increases of Eu$^{3+}$ concentration also give glass-ceramics with stronger emission of the light in red region.

Speaker: Ms Wipada Senanon (Department of Physics, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, THAILAND 34190)

1:00 PM Effect of Fabrication Method on the Structural and Magnetic Properties of Copper Ferrite

Copper ferrites (CuFe$_2$O$_4$) were fabricated by self-combustion urea and glycine process (UNP, GNP), polymerized complex (PC), solid-state reaction (SSR), and molten-salt (MS) methods. The synthesized powders were calcined in static air at different temperature from 500 – 900$^{\circ}$C. The effects of the fabrication method on the microstructural and magnetic properties were investigated. X-ray diffraction (XRD) analysis results revealed the cubic CuFe$_2$O$_4$ spinel structure for UNP and MS samples and tetragonal CuFe$_2$O$_4$ spinel structure for GNP, PC, and SSR samples. Scanning electron microscopy (SEM) investigation showed that the synthesized ferrite is made up of very fine nanoparticles. By using vibrating sample magnetometer (VSM) technique, a significant change in the magnetic properties was absorbed in CuFe$_2$O$_4$ system with fabrication method and heat treatment. The magnetic hysteresis loops measured at room temperature showed that the saturation magnetization increases with increasing calcinations temperature, whereas the coercivity values decrease.

Speaker: Ms Siriwipa Pongpadung (Materials Science and Nanotechnology Program, Faculty of Science, Khon Kaen University, Khon Kaen, THAILAND 40002)

1:00 PM Effect of Sintering Temperature on Behavior of Grain Shape and Grain Growth of Zn${}_{0.97}$Cu${}_{0.01}$V${}_{0.02}$O Ceramics

In this study, the Zn${}_{0.97}$Cu${}_{0.01}$V${}_{0.02}$O ceramics were sintered with It was sintered at the temperature of 900${}^{\circ}$C, 950${}^{\circ}$C, 1000${}^{\circ}$C and 1050${}^{\circ}$C for 5 hours and prepared by using mixed oxide method. The microstructure evolution of the ceramics were studied and investigated. It was found that the grain size were almost constant in the range of study. Furthermore, the faceted rounded grains with straight metal solid interfaces were observed in this study. Moreover, the grain size increased as the amount of sintering temperature. The change in grain size and microstructures evolution could be explained by using the reaction and the diffusion controlled grain growth at low and high temperatures, respectively. Moreover, the x-ray structural analysis indicated that the ceramics formation were dual-phase hexagonal and tetragonal crystal structures with angles between them are called the lattice parameters: Alpha=Beta=90,Gamma=120 and Alpha=Beta=Gamma=90, respectively. The SEM result indicated that the particle size increased with the increasing of sintering temperatures.The x-ray structural analysis indicated that the ceramics formation were dual-phase hexagonal and tetragonal crystal structures.This result confirms that the grain shape and grain growth mechanism can be changed by altering the kinetic factor of temperature.

Speaker: Mareenee Buesa (Department of Physics, Faculty of Science, Thaksin University, Songkhla, THAILAND 90000)

1:00 PM Effect of Temperature on Electrical Properties of BaCeO${}_3$ Ceramics

In this work, BaCeO${}_3$ were prepared by a solid-state reaction method. BaCeO${}_3$ were calcined at 1300 ${}^{\circ}$C for 10 h in air and sintered at various temperatures. Phase formation analysis by X-ray diffraction technique (XRD) revealed that the samples exhibited a perovskite structure. The microstructural analysis indicated that grain size of the ceramics increased with sintering temperature due to higher different at a higher temperature. The dielectric constant of the ceramics tended to increased with the sintering temperature increase. In addition, complex impedance analysis was applied to determine grain boundary and grain responses of the ceramics. The analysis suggested that the electrical properties of BaCeO${}_3$ depended on characteristics of grain and grain boundary.

Speaker: Mr Narongdetch Boothrawong (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai, THAILAND 50200)

1:00 PM Effect on the Mg$_2$Si Synthesized by Solid State Reaction and Hot Pressing Process

Metal/semiconductor Mg$_2$Si compounds was synthesized by solid state reaction method. The sample was calcined at temperature 973 K in vacuum system. It was pressed into pellet, and then was sintered in hot-pressing process at 973 K. The Mg$_2$Si was studied structure properties by XRD and SEM, electrical properties by Hall Effect at room temperature and thermal properties by laser flash method at 300 up to 500 K. Finally, the results of normal process and hot-pressing process effect on thermal conductivity were compared and reported.

Speaker: Mr Chalermpol Rudradawong (Department of Physics, Faculty of Science, King Mongkut's Institute of Technology Ladkrabang, Bangkok, THAILAND 10520)

1:00 PM Effects of Oxygen Vacancies on Dielectric Properties of Na${}_{1/2}$Bi${}_{1/2}$Cu${}_3$Ti${}_4$O${}_{12}$ Ceramics Prepared by a Urea Combustion Method

The influences of oxygen vacancies on the dielectric and electrical properties of Na${}_{1/2}$Bi${}_{1/2}$Cu${}_3$Ti${}_4$O${}_{12}$ ceramics prepared by a urea combustion method were investigated via annealing in oxidizing atmosphere. Interestingly, a single Na${}_{1/2}$Bi${}_{1/2}$Cu${}_3$Ti${}_4$O${}_{12}$ phase was successfully prepared using a low calcination temperature of 800 ${}^{\circ}$C for 6 h. High dielectric permittivity (${\varepsilon}^{\prime}$) and dense ceramic microstructure were achieved by sintering at a low temperature of 980 ${}^{\circ}$C. The values of ${\varepsilon}^{\prime}$ and tan$\delta$ were reduced by annealing in O${}_2$ atmosphere, which were described to correlate with the decrease in oxygen vacancies at grain boundaries. A decrease in low-frequency tan $\delta$ values can be well explained due to the reduction of DC conduction, which was primarily governed by the enhanced grain boundary resistance due to filling oxygen vacancies. A slight decrease in ${\varepsilon}^{\prime}$ due to the annealing process was attributed to the reduction of grain boundary capacitance. By annealing process, the conduction activation energy at the grain boundaries was significantly enhanced, whereas the conduction activation energy inside the grains did not change. The results clearly indicated the effects of oxygen vacancies at the grain boundaries on the giant dielectric response and correlated grain boundary response.

Speaker: Mr Wattana Tuichai (Materials Science and Nanotechnology Program, Faculty of Science, Khon Kaen University, Khon Kaen, THAILAND 40002)

1:00 PM Effects of Reagent Concentration and Ultrasound in the Co-precipitation Synthesis of Maghemite Nanoparticles Studied by Synchrotron X-ray Absorption Spectroscopy

Synchrotron X-ray absorption spectroscopy (XAS) was used to complement X-ray diffraction (XRD) in the characterization of iron oxide nanoparticles synthesized by the ultrasonic-assisted co-precipitation. The influence of ultrasound was highlighted by XRD showing impurity phases in the control synthesized without sonication. The hematite ($\alpha$-Fe${}_2$O${}_3$) phase was ruled out by XRD and the XAS spectra revealed the preference of the maghemite ($\gamma$-Fe${}_2$O${}_3$) phase over magnetite (Fe${}_3$O${}_4$). Results from XAS agreed with XRD patterns that $\gamma$-Fe${}_2$O${}_3$ nanoparticles had larger crystallite sizes and lower structural distortions when higher concentrations of Fe(NO${}_3$)${}_3$•9H${}_2$O, FeCl${}_2$•4H${}_2$O and NaOH and a longer sonication/reaction time were used. Moreover, the synthesis with lowly concentrated reagents gives rise to amorphous $\gamma$-Fe${}_2$O${}_3$.

Speaker: Mr Witoon Tangwatanakul (Molecular Technology Research Unit, School of Science, Walailak University, Nakhon Si Thammarat, THAILAND 80161)

1:00 PM Effects of Substrate Materials on Optical Behavior of ZnO:Al Film Prepared by RF-sputtering

Aluminum-doped ZnO (ZnO:Al) film was deposited by RF-sputtering on different substrates (glass, B-PTFE and W-PTFE). From SEM photographs, the thickness of sputtered ZnO:Al films was about 90 nm. XRD measurements confirms that sputtered ZnO:Al films show ZnO:Al phase in (002) direction. Peak intensity of ZnO:Al phase obviously depends on the type of substrate materials. The highest and lowest peak intensities were observed on the films deposited on glass and B-PTFE substrates, respectively. AFM result reveals that surface roughness of the films on glass substrate shows the lowest value and on W-PTFE substrate shows the highest value. Electrical resistance of the film on glass is about 27 $\Omega$ while on B-PTFE and W-PTFE substrates are the same value of about 26 $\Omega$. The average optical transmission in visible region of the film on glass, B-PTFE and W-PTFE substrates is 80, 60 and 18%, respectively. However, the film on B-PTFE substrate reaches the maximum optical transmission of about 80% in the second near-infrared region. The results imply that the optical properties of sputtered ZnO:Al film can be changed by the type of substrate materials.

Speaker: Ms Jantree Kheanwong (Department Department of Physics, Faculty of Science, Kasetsart University, Bangkok, THAILAND 10900)

1:00 PM Enhanced Dielectric Response in Na${}_{1/3}$Bi${}_{1/3}$Ca${}_{1/3}$Cu${}_3$Ti${}_4$O${}_{12}$/PVDF Composites by Filling with Ni Nanoparticles

In this work, Ni nanoparticle/PVDF-($f$=0.2)Na${}_{1/3}$Bi${}_{1/3}$Ca${}_{1/3}$Cu${}_3$Ti${}_4$O${}_{12}$(Ni/PVDF-NBCCTO) three-phase polymeric nanocomposites with different Ni were fabricated by a liquid-phase assisted dispersion and hot pressing at 200 ${}^{\circ}$C for 0.5 h. The microstructure of the fabricated polymeric nanocomposites were characterized by a scanning electron microscope. The dielectric properties were investigated as a function of frequency (10${}^2$-10${}^7$ Hz) at room temperature. It was found that the dielectric permittivity (${\varepsilon}^{\prime}$) of the Ni/PVDF-NBCCTO nanocomposites increased with increasing Ni filling concentration; whereas, the dielectric loss tangent (tan $\delta$) was also enhanced. The ${\varepsilon}^{\prime}$ values of the Ni/PVDF-NBCCTO nanocomposites with Ni volume fractions of 0.05, 0.10, 0.15, 0.20, 0.225, 0.25, and 0.275 were found to be 34.8, 40.5, 72.6, 119.6, 233.9, 210.7, and 1120.6, respectively. The enhanced dielectric response in the nanocomposites can be well described by the interfacial polarization and the formation of micro-capacitor in the microstructure.

Speaker: Ms Pornsawan Kum-onsa (Materials Science and Nanotechnology Program, Faculty of Science, Khon Kaen University, Khon Kaen, THAILAND 40002)

1:00 PM Enhancing the Cycling Stability of SnO${}_2$ Hollow Spheres for a Li-ion Battery Anode by Titanium Dioxide Coating

SnO${}_2$ material has attracted much attention due to its high theoretical capacity (790 mAh/g) compared to the current carbon- based anode (372 mAh/g). However, the SnO${}_2$ material exhibits a large volume expansion (up to 300 Vol. %) during charging and discharging, which causes crumbling and cracking of the electrode leading to large capacity loss and poor cycling stability. Creating SnO${}_2$ with unique nanostructure such as hollow spheres can reduce but not diminish the volume expansion. In this study, the effect of TiO${}_2$ coating in reducing the volume expansion of the SnO${}_2$ hollow spheres is investigated. Effects of different crystal structures of TiO${}_2$ and thickness of TiO${}_2$ coating are particularly studied. The results show that the amorphous TiO${}_2$ coating with a thickness of about 90 nm has the highest ability to accommodate the volume expansion of SnO${}_2$ hollow spheres leading to an improved cycling stability of the electrode.

Speaker: Songyoot Kaewmala (Materials Science and Nanotechnology Program, Faculty of Science, Khon Kaen University, Khon Kaen, THAILAND 40002)

1:00 PM Effects of Zn Substituted on the Structure of Hydroxyapatite Synthesized from Waste Chicken Eggshells

In this research, Zn substituted Ca hydroxyapatite synthesized from waste chicken eggshells were prepared precipitation method. The structure properties and morphology were investigated by X-ray diffraction (XRD) Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The results showed that the intensity of XRD pattern and crystallite size of hydroxyapatite decreased with increasing Zn concentration and function groups of hydroxyapatite and Zn were confirmed by FTIR. The hydroxyapatite was transformed to parascholzite (CaZn${}_2$ (PO${}_4$)${}_2$•2H${}_2$O) phase after added Zn more than 20 percent weight. The SEM images show that the particle size of hydroxyapatite reduced with increasing Zn concentration. The experimental results indicated that the Zn can be substituted Ca hydroxyapatite by precipitation method.

Speaker: Ms Chutharat Paikaew (Department of Physics, Faculty of Science, King Mongkut’s University of Technology Thonburi, Bangkok, THAILAND 10140)

Slides posterF.pdf

1:00 PM Fabrication and mechanical properties of doped-hydroxyapatite composite.

Ionic substitutions in hydroxyapatite (HA) have been extensively studied to improve its biological and/or mechanical properties. This work aimed to prepare and characterize the composite of polycaprolactone (PCL) and Zn-doped, Sr-doped or Zn/Sr-codoped HA. The doped HA nanoparticles were first prepared via a sol-gel method. XRD and FTIR results of the calcined powder showed that HA is the main phase, with b-TCP as the second phase and chemical composition is accordance to other public data. To prepare the composite, the doped HA and PCL powders were mixed at the ratios of 3:7, 4:6, 5:5 and 6:4, and then compressed into a disc shape using an uniaxial hydraulic pressing technique. The specimens were then subjected to a compression test. Young’s modulus was found to increase as the HA content increased. The composites with the 6:4 Sr-doped HA/PCL ratio have the values of compressive modulus of 16.26 GPa and compressive strength of more than 160 MPa which are close to those of compact bones.

Speaker: Likit Tp (urn:Facebook)

1:00 PM Fabrication of CsSnI$_{1-x}$F$_x$ Doped with ZnO for Photogenerated Holes in Solid-state Dye-sensitized Solar Cells

CsSnI${}_{1-x}$F${}_x$ doped ZnO were synthesized and used as the hole conducting in dye-sensitized solar cells (DSCs). The aim of this work is to study the effect of ZnO on the solid-stat DSC performances. CsSnI${}_3$ powders were prepared by heating a stoichiometric mixture of CsI (0.1 g) and SnI${}_2$ (0.07 g) at 450 ${}^{\circ}$C for 30 min in argon environment. CsSnI${}_{1-x}$F${}_x$ solution were prepared by mixing 0.1 g of CsSnI${}_3$ powder and 0.005 g of SnF${}_2$ into 3 ml of N,N-dimethylformamide and acetonitrile. CsSnI${}_{1-x}$F${}_x$ doped ZnO were prepared by adding ZnO (0.005 - 0.025 g) into the 3 ml CsSnI${}_3$ solution. The energy conversion efficiency of CsSnI${}_{1-x}$F${}_x$ doped ZnO solid state dye-sensitized solar cells (SSDSCs) were evaluated by a solar simulator (PEC-L11) under a light intensity of 100 mW/cm${}^2$. The efficiency of CsSnI${}_{1-x}$F${}_x$ doped ZnO SSDSCs are about 2.24%, 2.68%, 2.91%, 3.09%, 2.88% and 2.66% for 0.0 g (undoped ZnO), 0.005 g, 0.010 g, 0.015 g, 0.020 g and 0.025 g of ZnO, respectively. The detail effect of ZnO nanoparticles with the average size of 30 nm on the SSDSCs performance will be characterized by X-ray diffraction, scanning electron microscopy and UV-VIS spectroscopy.

Speaker: Ms Pornpanarat Ardchongthong (Materials Science and Nanotechnology Program, Faculty of Science, Khon Kaen University, Khon Kaen, THAILAND 40002)

1:00 PM Fabrication of Electrospun LiFePO${}_4$/Carbon Composite Fibers as a Cathode Material for Lithium-ion Batteries

LiFePO${}_4$/Carbon composite fibers were synthesized by using a combination of electrospinning and sol-gel techniques with LiOH•H${}_2$O, FeSO${}_4$•7H${}_2$O, H${}_3$PO${}_4$ and citric acid. Polyvinylpyrrolidone (PVP: 1,300,000 g.mol${}^{−1}$) was used as the fiber-forming agent in the electrospinning method and a carbon source for improving electronic conductivity of LiFePO${}_4$. Surface morphology and carbon coating features of the composite nanofibers were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray energy dispersive spectroscopy microanalysis (EDS). The electrochemical performance of LiFePO${}_4$/carbon composite fibers were evaluated using galvanostatic charge- discharge method.

Speaker: Ms Rattiya Hongtong (Materials Science and Nanotechnology Program, Faculty of Science, Khon Kaen University, Khon Kaen, THAILAND 40002)

1:00 PM Fabrication of Porous Ceramics for Controlling the Release of Bioactive Compounds in Combating Bee Parasites in Bee Hive

Porous ceramics are studied for natural extracts packaging application to control bee mites. Firstly, the amount of starting precursors such as cellulose (pore former) and PVP (surfactant) are varied to find the suitable preparing condition. The ratio of cellulose and PVP are affected by density and porosity of ceramic. The best ceramic condition is cellulose 10 g and PVP 3 cc with 90.54 % porosity. Second, the effects of lemongrass oil on *Varroa jacobsoni* and *Tropilaelaps mercedesae* mites are studied in laboratory scale. The % corrected mortality of *V. jacobsoni* mites and *T. mercedesae* mites were reported 100 %. However, controlled conditions have less that 25 % of corrected mortality. Finally, the effects of lemongrass oil on bees are studied. The lemongrass oil has no effects to bee population. The porous ceramics could be used to release lemongrass oil up to 30 days.

Speaker: Uraiwan Intatha (School of Science, Mea Fah Luang University, Chiang Rai, Thailand 57100)

1:00 PM Formation and Structure of ZrO${}_2$ Added Hydroxyapatite Synthesized from Waste Eggshells

Stabilized zirconia (ZrO${}_2$) added hydroxyapatites were synthesized from waste eggshells at different percent weigh from 1 to 15 with an increment 2 percent weight by precipitation method. The samples were dried at 100 ${}^{\circ}$C for 48 h, grounded with pestle and mortar into powder and heated from 200 to 1300 ${}^{\circ}$C. Structure properties of samples before and after heated were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). The XRD results show that the samples composed hydroxyapatite and tetragonal zirconium dioxide (t-ZrO${}_2$) phase. Hydroxyapatite phase was transformed to tricalcium phosphate (TCP) phase after heated at 700 ${}^{\circ}$C. At 1300 ${}^{\circ}$C, the sample had 3 phase of TCP, t-ZrO${}_2$ and CaZrO${}_3$ phase. The composited of samples were confirmed by FTIR results. The morphology and dispersive particle of samples were investigated by SEM.

Speaker: Mr Aekgaran Sangmala (Department of Physics, Faculty of Science, King Mongkut’s University of Technology Thonburi, Bangkok, THAILAND 10140)

Poster Nut.pdf

1:00 PM Gamma-ray Shielding and Structural Properties of P${}_2$O${}_5$-BaO-Bi${}_2$O${}_3$ Glass System

Fabrication of a (50)P${}_2$O${}_5$ - (50-$x$)BaO - ($x$)Bi${}_2$O${}_3$ glass systems where $x$ = 0, 2.5, 7.5, 12.5 and 17.5 mol% was carried out using a conventional melt-quenching method. The glass system has been investigated to see its potential use as radiation shielding material. The glass density was measured by using Archimedes principle. The micro-hardness of glasses was determined by ultrasonic velocities. The ultrasonic velocities were measured by the pulse echo technique, with a frequency of 4 MHz and at room temperature. FTIR spectroscopy has been used to study the structural properties of the prepared glass systems. The HVL (Half-Value Layer) show that this glass system is suitable as radiation shielding material and has some advantages comparing to the standard radiation shielding concrete.

Speaker: Mr Sarinthonthep Sainet (Department of Physics, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, THAILAND 34190)

1:00 PM Giant Dielectric Properties and Electrical Response Grain Boundary of Na${}_{1/3}$Ca${}_{1/3}$La${}_{1/3}$Cu${}_3$Ti${}_4$O${}_{12}$ Ceramics

The dielectric properties and electrical response of grain boundaries of Na${}_{1/3}$Ca${}_{1/3}$La${}_{1/3}$Cu${}_3$Ti${}_4$O${}_{12}$ ceramics were investigated as a function of frequency. High dielectric permittivity (${\varepsilon}^{\prime}\sim$10${}^4$) and low loss tangent (tan$\delta$<0.1 at 1 kHz) were observed in Na${}_{1/3}$Ca${}_{1/3}$La${}_{1/3}$Cu${}_3$Ti${}_4$O${}_{12}$ ceramics. Through analyses using a complex impedance spectroscopy, it was found that the dielectric properties of Na${}_{1/3}$Ca${}_{1/3}$La${}_{1/3}$Cu${}_3$Ti${}_4$O${}_{12}$ ceramics were closely related to the electrical response of grain boundaries. The investigation of electrical response of the grain boundary suggested that the potential barrier at the grain boundaries of Na${}_{1/3}$Ca${}_{1/3}$La${}_{1/3}$Cu${}_3$Ti${}_4$O${}_{12}$ ceramics was due to the Schottky effect. The giant low frequency dielectric response in Na${}_{1/3}$Ca${}_{1/3}$La${}_{1/3}$Cu${}_3$Ti${}_4$O${}_{12}$ ceramics is attributed to Maxwell-Wagner polarization at the grain boundaries.

Speaker: Mr Pariwat Saengvong (Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen, THAILAND 40002)

1:00 PM Improvement of Bar Bonding Method for Heat-Assisted Magnetic Recording Head

An important step in fabrication of slider magnetic recording head is bonding of bars on a fixture using hot melt synthetic adhesive. For bar bonding of heat-assisted magnetic recording (HAMR) head, the fixture feature is different from a standard fixture yield to excessive bonding agent (EBA) on blade line. Therefore, the aim of this work is to reduce the quantity of EBA on blade line. The effects of fixture heating time (5, 10, 15 and 20 min) at 140 ${}^{\circ}$C, curing time of bonding agent before bar bonding examined using Newton’s cooling law, and time of bar press (0.5, 1, 2 and 3 min) on the quantity of EBA were determined. The results showed that the quantity of EBA reduced with decreasing fixture heating time or increasing bar press time. Furthermore, it can be concluded that an appropriate bar bonding method for HAMR head is heating fixture at 140 ${}^{\circ}$C for 5 min, painting bond agent on fixture surface and leave for 30 s, placing bar on fixture, and pressing bar for 3 min. Using above conditions, the smallest amount of EBA with high adhesion efficiency was achieved.

Speaker: Mr Apiwat Phetsahai (Department of Physics, Faculty of Science, King Mongkut’s University of Technology Thonburi, Bangmod, Bangkok, THAILAND 10140)

1:00 PM Improvement of Mechanical Properties of Rattan Fiber–reinforced/Carbon Nanotube/Epoxy Resin Composites by Alkaline Treatment Method

In this work, mechanical properties of short rattan fiber (Calamus sp.7 of in San Pa Koi, Chiang Mai) approximately length 1.0 cm – Carbon Nanotube reinforced epoxy resin composites were investigated. Rattan fibers were treated in Sodium Hydroxide in different concentration and soaking time. To improve the ability of adhesion compare with non-soaked rattan fibers and destroy external surface, which is coated with waxy substances. Then, compare with different ratio of soaked and non-soaked fiber (5%, 10% and 15% v/v) for reinforced suitable. Moreover mix different ratio of the fibers and Carbon Nanotube and epoxy resin composites for testing mechanical properties, such as impact, stress etc. and the result are showed the impact and stress properties of soaked Rattan Fiber-reinforced/Carbon Nanotube/epoxy resin composited more stronger than soaked and non-soaked Rattan Fiber-reinforced epoxy resin composited and good agreement with SEM characterizations.

Speaker: Mr Priyavit Pattanakitkaset (Faculty of Science, Chiang Mai University, Chiang Mai, THAILAND 50200)

Poster Improvement_of_Mechanical_Properties_of_Rattan_Fiber–reinforcedCarbon_NanotubeEpoxy_Resin_Composites_by_Alkaline_Treatment_Method.pdf

1:00 PM Influence of LiSbO${}_3$ on Microstructure and Electrical Properties of Bi${}_{0.5}$(Na${}_{0.80}$K${}_{0.20}$)${}_{0.5}$TiO${}_3$ Ceramics

This research studied the effect of LiSbO${}_3$ on microstructure and electrical properties of lead-free Bi${}_{0.5}$(Na${}_{0.80}$K${}_{0.20}$)${}_{0.5}$TiO${}_3$ ceramics with the composition belonging to Bi${}_{0.5}$(Na${}_{0.80}$K${}_{0.20}$)${}_{0.5}$TiO${}_3$-LiSbO${}_3$ or (1-$x$)BNKT-$x$LS(when $x$ = 0, 0.005, 0.010, 0.015, 0.020 mol fraction). The BNKT-LS ceramics were prepared by a conventional mixed oxide method and sintered at 1100${}^{\circ}$C for 2h. X-ray diffraction pattern of all compositions exhibited a single perovskite structure without impurity phase. Scanning electron microscopy (SEM) was used to determine the microstructure of ceramics. Pure BNKT ceramic promoted a formation of cubic-like shape grains with an average grain size of 0.25 ± 0.05 mm. With increasing LS concentration, average grain size value gradually increased and showed the maximum value of 0.34 ± 0.10 mm at $x$ = 0.02. The addition of LS into BNKT ceramic did not obviously change grain morphology, however, it caused fracture surface to switch from mixed inter-transgranular fracture for pure BNKT to mainly transgranular fracture for LS-added samples. A large room temperature dielectric constant of 1367 and dielectric loss of 0.0435 were observed for BNKT-0.015LS sample.

Speaker: Ms Pimpilai Wannasut (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai, THAILAND 50200)

1:00 PM Influences of Sn Doping and CaTiO${}_3$ Volume Fraction on Microstructure and Electrical Response of Sn-doped CaCu${}_3$Ti${}_4$O${}_{12}$/CaTiO${}_3$ Composites

The influences of Sn doping concentration and CaTiO$_3$ volume fraction on microstructure and electrical response of Sn-doped CaCu$_3$Ti$_4$O$_{12}$/CaTiO$_3$ composites prepared from a nominal formula of Ca$_{1+x}$Cu$_{3-x}$Ti$_{4-y}$Sn${}_y$O${}_{12}$ (where $x$ = 0, 0.5, 1 and 1.5; $y$ = 0.05 and 0.30) were investigated. The dielectric properties of CaCu${}_3$Ti${}_4$O${}_{12}$/CaTiO${}_3 $ composites were measured as functions of frequency and temperature. The n-type semiconducting grains of CaCu${}_3$Ti${}_4$O${}_{12}$ phase and insulating interfaces between CaCu${}_3$Ti${}_4$O${}_{12}$-CaCu${}_3$Ti${}_4$O${}_{12}$ grains and CaCu${}_3$Ti${}_4$O${}_{12}$-CaTiO${}_3$ grains were studied by an impedance spectroscopy technique. The microstructure of Ca${}_{1+x}$Cu${}_{3-x}$Ti${}_{4-y}$Sn${}_y$O${}_{12}$ ceramics was slightly changed with increasing CaTiO${}_3$ volume fraction. The dielectric properties were strongly affected by Sn content and the volume faction of CaTiO${}_3$. At 1 kHz, the dielectric constant (${\varepsilon}^{\prime}$) increased with increasing Sn doping concentration. It was also found that ${\varepsilon}^{\prime}$ decreased with increasing CaTiO${}_3$ volume fraction. The activation energy for conduction within the grains slightly increased with increasing the Sn content; whereas, the activation energy for conduction at the internal interfaces decreased slightly. Interestingly, it was found that Egb increased significantly with increasing CaTiO${}_3$ volume fraction.

Speaker: Mr Jutapol Jumpatam (Materials Science and Nanotechnology Program, Faculty of Science, Khon Kaen University, Khon Kaen, THAILAND 40002)

1:00 PM Investigation of Elastic Property of Thermoelectric Materials Prepared by Bridgman Method

The study of thermoelectric material BiSbTe was prepared by Bridgman method with a growth rate 4 mm/hr. Structural investigation by using XRD technique. From the XRD pattern apparent peak at plane (1010) of BiSbTe and the orderly arrangement of unit cell. The longitudinal velocity was measured by ultrasonic method. Density was measured by Archimedes method (6.35 g/cm${}^3$). The longitudinal modulus of this material can be calculated by the longitudinal velocity and density (L = 39.6 GPa).

Speaker: Ms Kanyaphach Armart (Department of Physics, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, THAILAND 34190)

1:00 PM Lifetime Span Comparison of Self-Cleaning Glass Annealed by Laser and Furnace Heat Treatments

A self-cleaning glass was prepared by a sparking process. Specimens were coated with titanium oxide thin films, and were annealed by heating at 500 ${}^{\circ}$C using a laser and a furnace heat treatments. A lifetime span of the samples was tested by a rainfall simulator. Effect of the laser heat treatment for 10 mins was compared with that of a furnace heat treatment for 60 mins. It was found that water contact angles of the samples prepared by both conditions were approximately the same after accelerated test for 20 years. Furthermore, surface morphology of the samples before and after the tests was examined by atomic force microscopy and scanning electron microscopy. The results showed that the surface roughness of titanium oxide thin films after annealing with the laser and furnace heat treatments can be reduced from 18.39 nm to 8.99 nm and 9.81 nm, respectively. However, the glass transformation was not found in the samples annealed by the laser heat treatments.

Speaker: Ms Arisara Panthawan (Materials Science Research Center, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai, THAILAND 50200)

1:00 PM Metal Decorations on Graphene as a Hydrogen Storage Material

Metal binding energies of various metals such as Li, Be, B, Na, Al, Mg and Ca trapped on graphene and hydrogen adsorption energies corresponding to these metals are calculated by using the density functional theory. Our results reveal that Li, Be, Na, Al and Ca are trapped on the graphene with metal binding energies of about 3.49–3.87 eV. These binding energies are high enough to hold these metals on graphene at room temperature. Moreover, we also calculated the hydrogen adsorption energy when a hydrogen molecule is adsorbed on these considered metals and found that Li gives the highest hydrogen physisorption energy compared to all considered metals, namely about 0.136 eV. Consequently, Li is regarded as the best choice for adsorbing hydrogen molecule.

Speaker: Mr Suphagrid Wongprakarn (Materials Science and Nanotechnology Program, Faculty of Science, Khon Kaen University, Khon Kaen, THAILAND 40002)

1:00 PM Micro-structural Investigation of InGaAsN Lattice-matched Films Grown on Off-angle Ge (001) Substrates by MOVPE

In this work, the InGaAsN lattice-matched films were grown on off-angle Ge (001) substrates with inclined surfaces of 4$^{\circ}$ and 6$^{\circ}$ towards the [1 1 0] direction. All the samples were grown by metalorganic vapor phase epitaxy (MOVPE) using low temperature (550 $^{\circ}$C) GaAs buffer layer. To compare the InGaAsN film on on-axis Ge (001) substrate, micro-structural properties of the films on off-angle Ge (001) substrates were investigated by high-resolution X-ray diffraction (HRXRD), Raman scattering, atomic force microscopy (AFM) and transmission electron microscopy (TEM). Since, InGaAsN with about 1-eV bandgap and lattice-matching to Ge is a candidate component material for the InGaP(N)/InGaAs/ InGaAsN/Ge four-junction-structure solar cells. HRXRD 2$\theta$/$\omega$ (004) results showed the Pendellösung fringes which clearly indicate a flat interface and a smooth surface for the InGaAsN films on off-angle Ge substrates. Furthermore, the smooth surface with low RMS roughness was obviously observed by AFM. Cross-sectional dark-field TEM images showed the GaAs buffer layer with a few anti-phase domains (APDs) at the GaAs/Ge interface. And then, APDs-free InGaAsN layer was observed on the off-angle Ge substrates. On the other hand, both the InGaAsN films and the GaAs buffer layers on on-axis Ge substrates demonstrated a high density of anti-phase boundaries. Our results indicate that high structural quality InGaAsN lattice-macthed films were successfully grown on the off-angle Ge (001) substrates.

Speaker: Mrs Pornsiri Wanarattikan (Department of Physics, Faculty of Science, King Mongkut’s University of Technology Thonburi, Bangkok, THAILAND 10140)

1:00 PM Microstructure and Impedance Properties of Sr${}_{0.4}$Ca${}_{0.6}$La${}_4$Ti${}_5$O${}_{17}$ Ceramics Doped with ZnO

The microstructure and impedance properties of Sr${}_{0.4}$Ca${}_{0.6}$La${}_4$Ti${}_5$O${}_{17}$ ceramics were studied and determined. The ceramic was doped with 1, 2 and 3% mol of ZnO and prepared using mixed oxide method. It was sintered at the temperature of 1,400 ${}^{\circ}$C for 3 hours. The x-rays diffraction (XRD) technique and scanning electron microscope (SEM) were employed to exam the ceramics microstructure. In addition, the impedance properties of the ceramics were studied and characterized. It was found that the single phase which is SrTiO${}_3$ was appeared in 3% mol of doped ZnO ceramic. The ceramic had the cubic crystal structure with the space group Pm-3m and the average of grain size was in the range of 0.9 $-$ 0.99 micrometer. Moreover, the ceramics behaved as a semiconductor with maximum value of real and imaginary parts of impedance equal to 8.23x10$^5$ and 6.39x10$^6$, respectively.

Speaker: Ms Supunnee Srikeawnawan (Department of Physics, Faculty of Science, Thaksin University Songkhla Campus, Songkhla, THAILAND 90000)

1:00 PM Nano-materials from Rice Husks for Lithium Ion Battery Applications

Our research team has studied the potentials of producing nanostructured silicon and silica using rice husk as starting raw materials. We have developed several nanostructured silicon and silicon derivatives from agricultural wastes due to its large quantity, easy to process, and cheaper to be developed into nanomaterials with high economic value. Nano-silicon and its derivatives can be extracted from rice husk using our chemical and thermal processes. The purity of the silica (>91%) and the investigation crystalline phase formation using X-ray diffraction (XRD) found that the pure phase of silicon. The particle sizes of 10-20 nm and morphology particles are spherical particles can be obtained by the investigation microstructural characterization of nano-materials were carried out using Transmission electron microscopy (TEM) and scanning electron microscopy (SEM). These recovered nano-silicon exhibits high performance as Li-ion battery anodes with a reversible capacity of 1,300 mAhg${}^{-1}$. We can produce high performance electrodes from nano-silicon, silicon composite with carbon, and silicon composite with silicon carbide with sizes on the nanometer scale. Nano-silica can be used as raw material in the synthesis of lithium iron silicate (Li${}_2$FeSiO${}_4$) cathodes for lithium ion battery as well.

Speaker: Mrs Chirapan Chaikawang (Material Science and Nanotechnology Program, Faculty of Science, Khon Kaen University, Khon Khaen, THAILAND 40002)

1:00 PM New Dye Sensitizers from Anthraquinone Derivatives for Application in Dye-Sensitized Solar Cells: a DFT Study

New dye sensitizes from anthraquinone derivatives for application in dye–sensitized solar cells (DSSCs) were theoretical investigated. The ground and excited state properties of the dyes were studied by using density functional theory (DFT) at M06/6–311G(d,p) level and time–dependent DFT (TD–DFT) method at the same level, respectively. The introduction of the anthraquinone derivatives has been shown to interestingly affect the geometrical and electronic properties of dye sensitizes for the DSSCs. In addition, effects of dyes adsorbed on surface of semiconductor TiO${}_2$, namely dye@TiO${}_2$, were also investigated. Moreover, thermodynamic and optical properties have been studied and reported.

Speaker: Mr Sarawut Tontapha (Materials Science and Nanotechnology Program, Faculty of Science, Khon Kaen University, Khon Kaen, THAILAND 40002)

1:00 PM Phase Transition of LiMn${}_{0.85}$Cr${}_{0.15}$PO${}_4$ Cathode Material by In-Situ Time-Resolved XANES

Lithium metal phosphate olivine (LiMPO${}_4$; M= Fe, Mn, Co, Ni) have a great deal of attention as one of the promising cathode material for lithium ion batteries. To date, a considerable number of studies have enhanced the electrochemical behavior of LiFePO${}_4$ from being barely electrochemically active to having a full capacity at high rates. Based on the success of LiFePO${}_4$, an increasing number of research groups have focused their attention on LiMnPO${}_4$, which exhibits an obvious advantage over LiFePO${}_4$ with a redox potential of 4.1 V VS Li/Li${}^+$. However, the LiMnPO${}_4$ kinetics is unusually sluggish due to its intrinsically low ionic and electronic conductivity. Many techniques, including to carbon coating, nano-sized using and aliovalent doping have been done to improve rate capability of this material. The doping of LiFePO${}_4$ with Cr${}^{3+}$ has been investigated in several previous studies which show an enhancement in conductivity and rate performance. However, the Cr-associated mechanism during charge/discharge is not yet revealed. Here, we report phase transition investigation of LiMn${}_{0.85}$Cr${}_{0.15}$PO${}_4$ cathode material by in-situ time-resolved XANES.

Speaker: Mr Sarawut Pongha (Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen, THAILAND 40002)

1:00 PM Photocatalytic Properties of Hydrogenated Titanium Dioxide Thin Films Prepared by Sparking Method

Titanium dioxide (TiO${}_2$) is a widely used photocatalyst in water splitting process for hydrogen production. In this study, hydrogenation of the titanium dioxide thin films was investigated in order to examine the photocatalytic properties and to improve the performance for photoactivity. Titanium dioxide thin films were prepared by sparking method, then annealed at 500 ${}^{\circ}$C in hydrogen atmosphere to get hydrogenated titanium dioxide thin films (H:TiO${}_2$). The result of scanning electron microscopy and atomic force microscopy showed that the thickness of films was 2 µm. The film was porous with high specific surface area which promotes good photocatalytic activity. UV-Vis-NIR spectrometer measurement indicated that the sunlight absorbance of H:TiO${}_2$ was more than the absorbance of TiO${}_2$. For these results suggest that H:TiO${}_2$ has better photocatalytic properties than the TiO${}_2$.

Speaker: Ms Porntipa Pooseekheaw (Materials Science Research Center, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai, THAILAND 50200)

Poster Poster_SPC2015_porntipa.pdf

1:00 PM Preparation and Characterization Chitosan/Hydroxyapatite Composites from Waste for Bio-applications

In this research, chitosan/hydroxyapatite (HAp) composites were prepared using precipitation method. The calcium oxide from waste chicken eggshells as a calcium source was mixed with nitric acid. Chitosan of shrimp solution different percent weight from 1 -15 were added to phosphate solution. The both of the solution were mixed, stirred for 6 h, precipitate forming a chitosan/HAp composite and annealed at 100 ${}^{\circ}$C for 4 h. The structure properties and morphologies of composites were investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The results showed that the crystal structure of composites was decreased with increased %wt of chitosan. FTIR was used to investigate the major transmitting bands of all HAp and chitosan. The amounts of chitosan were increased as increased the particle size of composites. These experiments showed that the chitosan can be mixed into hydroxyapatite for composites material.

Speaker: Mr Chalongwut Boonpratum (Department of Physics, Faculty of Science, King Mongkut’s University of Technology Thonburi, Bangkok, THAILAND 10140)

Poster Poster_Krit.pdf

1:00 PM Preparation and dielectric properties of poly (vinylidenefluoride hexafluoropropylene) fibers

Electrospinning technique has been greatly interested to fabricate nanoscale fibers due to its ease of preparation and adjustment. In this project, the objective is to design and construct the electrospinning setup to replace the high cost and imported electrospinning apparatus. Poly (vinylidenefluoride hexafluoropropylene; P(VDF-HFP)) was used a model polymer to produce fibers to study the effect of fabrication and parameters on morphology and average sizes of fibers, including the distances between tip and collector (9, 10, 11, 12 and 13 cm) and polymer concentrations (33.33, 25.00, 20.00 and 16.67 % W/V) . The morphology and average sizes of fibers were investigated by scanning electron microscope (SEM). Moreover, dielectric constant of these polymer fibers were evaluated by LCR meter. The results showed that the electrospinning setup can produced smooth, identically and high density fibers. According to the optimized condition to fabricated P(VDF-HFP) fibers was 11cm and 20 % concentration. The dielectric constant of obtained fibers is related with average sizes of fibers and texture of polymer.

Speaker: Ms Kanokwan Nawaka (Prince of Songkla University)

1:00 PM Production of Biodiesel through Transesterification of Palm Oil Using Waste Eggshells Catalyst

The aim of this research was synthesized biodiesel from palm oil using transesterification calcium oxide from various eggshells catalyst. The chicken, duck, ostrich, quail, and crocodile eggshells were heated at 1300 ${}^{\circ}$C for 4 h. The ratio of methanol, palm oil and calcium oxide from eggshell were 10 g, 3.0 ml and 0.8 g, respectively. The temperature of biodiesel synthesis was control at 65 ${}^{\circ}$C for 3 h. The properties of biodiesel from eggshell catalyst and commercial were characterized by UV-vis spectroscopy, Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic spectroscopy (NMR). The UV-vis and FTIR results show that the biodiesel synthesized from all eggshells catalyst were corresponding with commercial biodiesel. The NMR results show that the yield of biodiesel from CaO of quail eggshells catalyst had higher than other eggshells. This research shows that the CaO from waste eggshells catalyst can be used transesterification of biodiesel.

Speaker: Ms Juthamas Inthanont (Department of Physics, Faculty of Science, King Mongkut’s University of Technology Thonburi, Bangkok, THAILAND 10140)

Poster Poster_Juthamasin_pdf.pdf

1:00 PM Raman scattering of the N-related vibrational modes in high N-content GaPN films grown on GaP (001) substrates by MOVPE

The N related vibrational modes (N-RVMs) in high quality GaPN films (0 < N ≤ 5.4 at%) on GaP (001) substrates grown by metalorganic vapor phase epitaxy (MOVPE) have been investigated. This study used two sets of samples with different growth times of 5 min and 10 min. N contents, which were examined from high resolution X-ray diffraction (HRXRD) measurements, are 1.8 at%, 2.9 at% and 3.6 at% for growth time of 5 min and are 0.8 at%, 1.8 at%, 3.4 at% and 5.4 at% for growth time of 10 min. Mirror like surface and fairly flat interface were observed for all the films. Atomic force microscopy (AFM) images showed smooth surfaces with root mean square (RMS) roughness lower than 0.5 nm. These results suggest that the high quality GaPN films with high N contents were obtained, despite the fact that an incorporation of N is as high as 5.4 at%. Raman spectroscopy studies were performed to examine the effect of N incorporation on the vibrational modes of the GaP lattice. It is clearly observed that Raman spectra between 440 and 520 cm$^{-1}$ were significantly influenced by the N incorporation, which is attributed to N-RVMs. Integrated Raman intensity ratio of N-RVMs with respect to GaP-LO phonon (at 401 cm$^{-1}$) linearly increased with the N incorporation. Additionally, the N-RVMs, which are attributed to the NN$_i$-pairs, were remarkably appeared at 465 cm$^{-1}$ and 485 cm$^{-1}$ for the films with N contents higher than 1.8 at%. While, local vibrational mode (LVM) of the isolated N-atoms on P sites was clearly observed near 500 cm$^{-1}$.

Speaker: Mr Noppadon Toongyai (Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok, THAILAND 10330)

1:00 PM Simulation and Design High-temperature Microwave Furnace for Thermoelectric Material Synthesis

The thermoelectric is a device that can generate electric energy from solar and waste thermal energies, and generate temperature gradient from electric energy for cooling applications. Recently, researchers are interested in the synthesis of thermoelectric material by microwave furnace. Because the performance of thermoelectric materials are increased by microwave assisted synthesis method because of rapid sintering as leading to small gain size. High-temperature microwave furnace technology is complicated in the design and control system. The commercial high-temperature microwave furnaces are very expensive. In this research, we will develop high-power microwave furnace for synthesis of thermoelectric materials. The design of microwave furnace is optimized by Comsol multiphysics modeling of wave filed propagation in the waveguides and cavity. The waveguide modules are installed on all four sides of the square cavity. The microwave’s door has chokes for microwave field leakage protection. The boundary conditions of waveguides and cavity are perfect conductor. The results show that a cavity size is 28x28x28 cm. and the waveguides are installed to the opposite angle of 90 degrees to each other. The distribution of high intensity microwave radiation in the middle of a cavity and low intensity in the waveguide. The configuration and dimension of the chokes are determined. The fabrication of the furnace is in progress.

Speaker: Mr Direk Boonthum (Plasma technology for agricultural applications research laboratory, School of Science, Walailak University, Nakhonsithammarat, THAILAND 80160)

1:00 PM Sonochemical Synthesis of ZnO Nanospheroid

Spheroidal ZnO nanostructures were synthesized by ultrarapid sonochemistry using 0.1 M zinc nitrate (Zn(NO${}_3$)${}_2$) and 0.2 M sodium hydroxide (NaOH) aqueous solution. These chemical solutions were sonicated under ambient conditions without any template, surfactant, and chelating agents. Only 30 min was needed to complete the formation of highly crystallized nanospheroids. As-prepared ZnO products were characterized by powder X-ray diffraction (XRD) and scanning electron microscope (SEM). The results reveal that spheroidal structures possess a hexagonal wurtzite structure with diameters between 60 and 230 nm. Both concentration of the precursors and ultrasonic irradiation time played a critical roles for formation and optical properties of ZnO nanospheriods. The room temperature photoluminescence (PL) spectra showed a UV emission peak at around 390 nm and a broad visible emission band at around 650 nm. These spheroidal nanostructures may promising applications in anti-aging, anti-microbial, and photocatalytic activities.

Speaker: Dr Chat Pholnak (Department of Physics, Faculty of Science, Thaksin University, Phatthalung, THAILAND 93210)

1:00 PM Strain modification of MOVPE grown cubic GaN on GaAs (001) with GaN/AlGaN multi-interface buffer layer

We have investigated cubic GaN (c-GaN) layers on GaAs (001) substrates by using high resolution X-ray diffraction (HRXRD) to verify strain modification due to a use of the GaN/AlGaN multi-interface buffer layer. To examine lattice parameters and residual strain, both a symmetric (002) and an asymmetric (113) reflections were performed using 2θ-ω mode HRXRD for different types of c-GaN samples. Cross-sectional scanning electron microscopy (SEM) images were used to verily thicknesses of the buffer layer and the GaN top layers. It is found that the fully relaxed lattice constant of c-GaN was determined to be closer to the values of a hypothetical perfect crystal (4.503 Å). Besides, a type of buffer layers remarkably effects on an in-plane strain (ε$_{\textrm{//}}$), which is caused by a combination of a large lattice-mismatch and a difference of thermal expansion coefficients between GaAs and c-GaN. The c-GaN layers with the AlGaN/GaN structure exhibited a tensile strain. While, the c-GaN layers on the conventional low-temperature grown c-GaN buffer layer were examined to be under compressive strain. With the use of GaN/AlGaN as a buffer layer, residual strain in c-GaN thick layers were adjusted to be a tensile strain. Based on our results, we interpreted this strain modification as a competition between the lattice-mismatch and thermal mismatch stresses. This indicates that the relief of strains in the c-GaN layers has a complicated dependence on a type of buffer layers, especially for multi-interface buffer layer.

Speaker: Mr Kunpot Mopoung (Nanoscience and technology, Graduate school, Chulalongkorn University, Bangkok, THAILAND 10330)

1:00 PM Strongly Enhanced Dielectric Response and Dielectric Relaxation in BaTiO${}_3$/poly(vinylidene fluoride) Nanocomposites

In this research work, the BaTiO${}_3$/poly(vinylidene fluoride) (BT/PVDF) nanocomposites were prepared by a solution processing method using spherical BT nanoparticles (<100 nm) with different volume fractions ($f_{\text{BT}}$ = 0$-$0.4). The microstructure of the nanocomposites was characterized by scanning electron microscope. It was found that the strong agglomeration of BT nanoparticles with large spherical cluster of about 10-30 $\mu$m in diameter was formed in the microstructure. Dielectric relaxation behavior in BT/PVDF nanocomposites was investigated at room temperature using a simple parallel capacitor technique. The strong low-frequency dependence of the dielectric permittivity was observed in the BT/PVDF nanocomposites, especially for high-loading BT nanoparticles. This was accompanied with the appearance of the relaxation peak of the loss tangent. The dielectric permittivity and loss tangent values at $10^3$ Hz of the BT/PVDF nanocomposites with $f_{\text{BT}}$ = 0.4 were found to be 623.3 and 0.887, respectively. This enhanced dielectric permittivity is significantly larger than that of the PVDF polymer matrix by a factor of about 50. The strongly enhanced dielectric response was described based on the strong dipole polarization in the large clusters of agglomerated BT nanoparticles and the interfacial polarization at the large interface area of PVDF thin layer between BT clusters.

Speaker: Ms Kanyapak Silakaew (Materials science and Nanotechnology Program, Faculty of Science, Khon Kaen University, Khon Kaen, THAILAND 40002)

1:00 PM Structural and elastic properties investigation of recycle silica gel glass by FTIR and ultrasonic technique

The aim of this work was to study the structural and elastic properties of recycle silica gel glass (denoted as RSGG) using FTIR and ultrasonic technique. The 10CaO – xPbO – (90–x)silica gel glass system (where x = 20, 25, 30, 35, 40 and 45 mol.%) were prepared. In this work, the silica gel was acquired from silica gel degradation in our laboratory. Densities of glass samples with PbO content were measured by Archimedes’s principle using n-hexane as immersion liquid. The longitudinal and shear ultrasonic velocities were measured by using pulse echo technique of 4 MHz at room temperature. Densities data and the ultrasonic velocities data of glass samples were used for calculated the elastic properties such as longitudinal modulus, shear modulus, bulk modulus and Young’s modulus. The results shows that change in elastic properties of the glass samples depend on the concentration of PbO and this can be confirmed using FTIR techniques.

Speaker: Mr Poonnaphob Sopapan (Department of Physics, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, THAILAND 34190)

1:00 PM Structural Investigation of Strontium Lead Silicate Glass Prepared from Silica Gel Waste Using Ultrasonic and FTIR Spectroscopy

Preparation of the glass 6 samples in the system 10SrO – $x$PbO – $(90-x)$Silica gel where $x$ = 20, 25, 30, 35, 40 and 45 mol%. The principle of Archimedes was used to measure the density of the glass samples. The ultrasonic velocities of the glasses were determined at room temperature by using pulse echo technique. The velocity data of the glass system have been used to find the elastic moduli. FTIR spectroscopy which measure in range 400-2000 cm${}^{-1}$ were used to study the structural properties of the glass samples. The results supported our discussion of the formation of NBO and BO in the structural of glass systems.

Speaker: Ms Pattaranipa Gunhakoon (Department of Physics, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, THAILAND 34190)

1:00 PM Study of Thermoelectric Structure Prepared by Hydrothermal Method

Thermoelectric material is very important in the future, because the materials could be used as renewable energy. The PbTe group material prepared by hydrothermal preparation method was studied. Thermoelectric AgPb`${}_{18}$`SbTe`${}_{20}$` alloys were prepare by hydrothermal method at 180 ${}^{\circ}$C for 20 h from AgNO${}_3$, Pb(NO${}_3$)${}_2$, SbCl${}_3$ and TeO${}_2$ compounds and were dried in vacuum furnace for 6 h. The products were investigated by x-ray diffractometer (XRD). The patterns of PbTe in the planes (200) and (220) were observed in the powder sample. Next parts, the powder will be prepared to bulk materials and investigated thermoelectric properties.

Speaker: Mrs Phitsamai KAMONPHA (Department of Physics, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, THAILAND 34190)

1:00 PM Substrate Surface Orientation Dependent GaN Grown on GaAs by MOVPE

This work presents a comparative study on the effect of substrate surface orientation on the growth of GaN by metalorganic vapor phase epitaxy (MOVPE). GaN films was successfully grown on both the (001)- and (110)-oriented GaAs. With compared to GaN on (001)-oriented GaAs, GaN on (110)-oriented GaAs showed a flat surface and a smooth interface. Root mean square roughness (RMS) measured by atomic force microscopy (AFM) was 61.1 nm and 10.3 nm for the films on (001) and (110)-oriented GaAs, restively. Structural characterization of GaN on (001)-oriented GaAs, which was performed by X-ray diffraction (XRD), exhibited a metastable cubic structure, which slightly contained stacking faults (SF), indicating a generation of hexagonal structure. On the other hand, a mixed structure between cubic and hexagonal structures was observed for the GaN on (001)-oriented GaAs. In order to verify a specific crystal structure, micro-Raman scattering spectroscopy was performed with two different excitation wavelengths of 514 nm and 633 nm. Raman spectra showed phonon modes of cubic-TO at 556 cm$^{-1}$ and hexagonal E$_2$-high at 569 cm$^{-1}$ for both excitation wavelengths. It was found that phonon mode, corresponding to hexagonal A$_1$ (TO), was observed at 535 cm$^{-1}$ when the excitation wavelength of 514 nm was used. While, Raman spectra with the excitation wavelength of 633 nm did not show the presence of this phonon mode. Furthermore, when the excitation wavelength was changed from 514 nm to 633 nm, Raman scattering peak at 736 cm$^{-1}$ , which is a signature of hexagonal A$_1$ (LO), was slightly shifted to the cubic-LO phonon at 740 cm$^{-1}$ . Our results verify that substrate surface orientation a key parameter used to control crystal structure of GaN

Speaker: Mr Pitshaya Praigaew (Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok, THAILAND 10330)

1:00 PM Synchrotron X-ray Absorption Spectroscopy Study of Local Structure in Hydroxyapatite Doped by Strontium

Generally, the medical treatment of osteoporosis was used orally by strontium-base medicine because of its stimulative effect on bone formation. In this work, Hydroxyapatite-based bone (HAp) doped by Sr was investigated for the global structure by X-ray diffraction technique and the local structure by Synchrotron X-ray Absorption Spectroscopy technique. The Sr L$_3$-edge X-ray Absorption Near-Edge Structure (XANES) spectra were measured and compared with the simulated spectra. The results show that the local environment of Sr distribute on the different locations of Ca site in Hydroxyapatite material. The Sr was found to substitute on the two different Ca sites with the proportion around 70% in the calcium phosphate site (Ca1) and 30% in Ca2 site close to -OH group.

Speaker: Mr Atipong Bootchanont (School of Physics, Institute of Science, and COE-NANOTEC-SUT on Advanced Functional Nanomaterials, Suranaree University of Technology, Nakhon Ratchasima, THAILAND 30000)

1:00 PM Synthesis and Characterization of Iron-doped Hydroxyapatite by Sol–Gel Method

Nanoporous materials of Ca${}_{(10-x)}$Fe${}_x$(PO${}_4$)6(OH)${}_2$ (FeHAp, x = 0, 0.1, 0.2, and 0.3) were successfully synthesized by sol–gel method. To obtain FeHAp, the prepared precursors were calcined in air at 600, 700 and 800 oC for 2 h. The samples were characterized by X–ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and transmission electron microscope (TEM) observation. The XRD results confirm the formation of HAp phase with a small trace of beta-tricalcium phosphate phase. The crystallite sizes of the powder were found to be 30–60 nm as evaluated by the XRD line broadening method. The morphology of the samples was nanoporous particles of size less than 100 nm as evaluated by TEM. With increasing the Fe-substituted, the particle size of the FeHAp decreased.

Speaker: Dr Jutharatana Klinkaewnarong (Program in Physics, Faculty of Science, Udon Thani Rajabhat University)

1:00 PM Synthesis and Characterization of Vanadium Oxide Film by Sparking Method for Thermochromic Application

Vanadium dioxide (VO${}_2$) has a great potential to be utilized as thermochromic glazing for improving the energy efficiency of buildings. The famous semiconductor-to-metal phase transition (SMT) property of VO${}_2$ shows the reversible optical properties when the temperature is above the critical point at 68 ${}^{\circ}$C. In this work, VO${}_2$ films were prepared by sparking method on glass substrates and annealed for 2 – 6 hours at 300 – 500 ${}^{\circ}$C. Thickness of VO${}_2$ films was varied from 100 to 500 nm by increasing the sparking cycles. The surface morphology of samples was analyzed by atomic force microscopy and scanning electron microscopy. The solar reflectance and transmittance were investigated by UV-Vis-NIR spectroscopy. The results show that the roughness of the films was decreased by rising the annealing temperatures and the near-infrared transmittance trend of products were dropped down by controlling the working temperatures from 30 to 90 ${}^{\circ}$C.

Speaker: Mr Winai Thongpan (Materials Science Research Center, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai, THAILAND 50200)

Poster Poster_Winai-SPC.pdf

1:00 PM Synthesis and Electrochemical Properties of SnO${}_2$ Nanostructures via a Hydrothermal Method for Li-ion Batteries.

Tin oxide (SnO${}_2$) is one of the promising high capacity anode materials for next generation lithium ion batteries due to its ability to uptake a large amount of Li-ion. SnO${}_2$ can provide twice as high specific capacity as graphite electrode currently used in commercial Li-ion batteries today. Therefore, using SnO${}_2$ will reduce the amount of materials used to make the electrodes and reduces the production cost of the materials. In addition, the batteries made by using SnO${}_2$ as the anode will be lightweight and have small size. In this project, SnO${}_2$ was synthesized into three structures: nanoparticle, nanosphere and hollow nanosphere via hydrothermal method. The electrochemical properties were measurement using a galvanostatic mode. We found that the SnO2 nanoparticles provided the highest storage capacity due to its compacted structure with capsule-like nanostructure. The specific capacity at C/5 of the first cycle was around 2200 mAh/g and the average capacity at 1C over 20 cycles was around 660 mAh/g. These results indicate that SnO${}_2$ nanostructures synthesized in this work have a more superior performance than graphite and can be used to replace graphite electrode in lithium-ion batteries.

Speaker: Ms sunisa buekeaw (Materials Science and Nanotechnology Program, Faculty of Science, Khon Kaen University, Khonkaen, THAILAND 40002)

1:00 PM Synthesis of Gold Nanorods with Different Aspect Ratios for Sensing Applications

Gold nanorods show great potential in applications such as imaging, drug delivery, photothermal therapy and biosensing. The optoelectronic properties strongly depend on their sizes and shapes. In this work, gold nanorods with different aspect ratios are synthesized by a seed-mediated growth method. The gold seeds are prepared by the reduction of Gold (III) chloride trihydrate (HAuCl${}_4$) with sodium borohydride (NaBH${}_4$) and cetyltrimethylammonium bromide (CTAB). In the growth process, the role of silver ion and pH on the formation of rod shapes is investigated. The gold nanorods are characterized using transmission electron microscopy (TEM) and UV-visible spectroscopy. The results show that the amount of silver ion yields gold nanorods with different aspect ratios. At high concentration of silver ion, the rectangular shape is observed. In the presence of hydrochloric (HCl) solution, the growth rate of gold nanorods is lowered. The gold nanorods are observed in higher aspect ratio. The localized surface plasmon resonance (LSPR) wavelength of the gold nanorods are shown at 520 nm and 740 nm, corresponding to the transversal and longitudinal plasmon resonance, respectively. The aspect ratio of nanorods can be tailored by varying the amount of silver ion and acidic condition. This method could be used to selectively produce gold nanorods with different sizes and shapes for sensing application.

Speaker: Ms Sawinee Ngernpimai (Materials Science and Nanotechnology Program, Faculty of Science, Khon Kaen University, Khon Kaen, THAILAND 40002)

1:00 PM Synthesis Thermoelectric Material Mg$_2$Si by Quartz Tube Vacuum Furnace from Starting Mg Powder and SiO$_2$ Rice Husk

In this work, magnesium silicide (Mg${}_2$Si) compounds were prepared by solid state reaction with sintering in quartz tube vacuum. Ball milling process is used in the mixture of magnesium (Mg) powder and pure silica obtained from thermal decomposition of rice husks. After that, the powder sample were sintered at 650$^{\circ}$C for 60, 120 and 180 minutes in quartz tube vacuum with argon atmosphere. The XRD patterns show the peak of Mg$_2$Si and MgO was dominant with all conditions. Subsequently, the chemical process to get rid of MgO.

Speaker: Phonlakit Khowjalern (Department of Physics, Faculty of Science, King Mongkut's Institute of Technology Ladkrabang, Bangkok, THAILAND 10520)

1:00 PM Synthesis Thermoelectric Material Mg${}_2$Si by Quartz Tube Vacuum Furnace from Starting Mg Powder and SiO${}_2$ Rice Husk

Magnesium silicide (Mg${}_2$Si) is a promising for thermoelectric materials due to display a high performance for thermoelectric power generation with ZT about 0.9 at operation temperature 600 to 800 K. This work, Mg${}_2$Si compound was prepared from starting powder of SiO${}_2$, which was attracted from rice husk, and Mg powder. The sintering process was performed in quartz tube vacuum at temperature 650 ${}^{\circ}$C with argon atmosphere. Then MgO composition was demolished by chemical process. XRD patterns showed the pure phased of Mg${}_2$Si. Thermoelectric characterization and properties will be reported.

Speaker: Mr Phonlakit Khowjalern (Department of Physics, Faculty of Science, King Mongkut's Institute of Technology Ladkrabang, Chalongkrung Rd., Ladgrabang, Bangkok 10520, Thailand)

1:00 PM Synthesis, Optical and Magnetic Properties of CuCr${}_{1-x}$Fe${}_x$O${}_2$ Delafossite Oxide

Delafossite CuCr${}_{1-x}$Fe${}_x$O${}_2$ (0.0 ≤ $x$ ≤ 0.15) semiconductors were synthesized by self-combustion urea nitrate process. The effects of Fe concentration on microstructural, optical and magnetic properties were investigated. X-ray diffraction (XRD) analysis results reveal the delafossite structure of all the samples. The lattice spacing of CuCr${}_{1-x}$Fe${}_x$O${}_2$ increased slightly with increasing substitution of Fe at the Cr site. The optical properties at room temperature exhibited the transparent in the visible region with direct optical band energy gap of 3.5 eV. The magnetic hysteresis loops measured at room temperature showed that the CuCrO${}_2$ samples exhibit paramagnetic behavior. However, a weak ferromagnetism property was found at the Fe-doped CuCrO${}_2$ samples up to 15%. The substitution of Cr${}^{3+}$ by Fe${}^{3+}$ produces a mixed effect on the magnetic properties of CuCrO${}_2$ delafossite oxide.

Speaker: Ms Chutirat Taddee (Materials Science and Nanotechnology Program, Faculty of Science, Khon Kaen University, Khon Kaen, THAILAND 40002)

1:00 PM The Effect of Calcination Temperature on the Dielectric Properties of $(1-x)$BaZr${}_{0.25}$Ti${}_{0.75}$O${}_3$+$x$SrFe${}_{0.5}$Nb${}_{0.5}$O${}_3$ ceramics

In this research, The $(1-x)$BaZr${}_{0.25}$Ti${}_{0.75}$O${}_3$-$x$Sr Fe${}_{0.5}$Nb${}_{0.5}$O${}_3$ ($(1-x)$ BZT+ $x$ SFN) with 0 ≥$x$ ≥0.9 ($x$ = 0.0$-$0.9) mol% were prepare by solid-state method. The powder were calcined at 1250 ${}^{\circ}$C for 3 h and 1300 ${}^{\circ}$C various dwell times ( 3, 6, and 12 h) and then sintered at 1450 ${}^{\circ}$C for 4 h. Effect of calcination temperature on the physical properties of $(1-x)$ BZT+ $x$ SFN lead-free ceramic was investigated. Phase formation, microstructure, and dielectric properties were investigated. The ceramics of $x$=0.7 exhibited a perovskite structure with cubic symmetry. Furthermore, the ceramics exhibited a dielectric relaxation like behavior with high dielectric constant over a wide temperature rang. The impedance measurements indicated that bulk and grain boundary resistance of BZT ceramics had a strong effect on the dielectric behavior.

Speaker: Ms Lalita Tawee (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai, THAILAND 50200)

1:00 PM The Effect of Calcination Temperature on the Properties of the NiO Films

A NiO film was prepared by heating solution made of nickel acetate dissolved in acetic acid which were drop-casted on a fluorine-doped tin oxide (FTO) substrate. This simple preparation technique has rarely been investigated in the open literatures. The effect of heating temperatures from 250 ${}^{\circ}$C to 500 ${}^{\circ}$C on structural, morphological, electrical and capacitive properties of the films were evaluated. With the increasing temperatures, there were improvement in the crystallinity of NiO and enlargement of NiO's crystallite size, moreover, the films' resistance increased whilst their capacitance values only slightly decreased. The optimum temperature suitable for preparing the NiO film was 300 ${}^{\circ}$C, where the highest capacitance of 150$-$200 F/g were obtain for a symmetrical capacitor made from NiO electrode and 6 M KOH electrolyte solution.

Speaker: Mr ADULPHAN PIMSAWAT (Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen, THAILAND 40002)

1:00 PM The Effect of CaO from Cassava Rhizome to Structural and Elastic Properties of Strontium-borate Glass Systems

The glass system of $x$CaO - (50-$x$)SrO – 50B${}_2$O${}_3$ ($x$ = 0, 10, 20, 30, 40 and 50 wt.%) were prepared using the conventional melt quenching technique. In this work, the calcium oxide was acquired from Cassava Rhizome. Elastic properties of the glasses were determined at room temperature by measuring ultrasonic velocities (both longitudinal and transverse) at a frequency of 4 MHz. The density of glass samples were measured by Archimedes’ principle using n-hexane as the buoyant liquid. From these obtained velocities and densities, Elastic moduli were calculated. All of these parameters were depend upon the CaO concentration. The structural properties of the glasses sample were studied by using Fourier Transform Infrared spectroscopy (FTIR). The obtained results supported our discussion of the formation bridging oxygen (BO) and non-bridging oxygen NBO).

Speaker: Mr Raewat Laopaiboon (Department of Physics, Faculty of Science, Ubon Ratchatani University, Ubon Ratchatani, THAILAND 34190)

1:00 PM The Effect of Doping Cu${}_2$O on Elastic and Structural Properties of Thermoluminescent Glass 90RWG – 10Na${}_2$O – xCu${}_2$O

The purpose of this work was to study the elastic and structural properties of recycle window glass thermoluminescent dosimeter using ultrasonic technique and FTIR spectroscopy. The thermoluminescent glass system 90RWG – 10Na${}_2$O – $x$Cu${}_2$O (where $x$ = 0.001, 0.01, 0.1 and 1.0 mol %) were prepared using the melt quenching technique consisting of 5 hr of 1250${}^{\circ}$C melting and 2 hr of 500${}^{\circ}$C annealing. Densities of glass sample with varied Cu${}_2$O dopant were measured. The longitudinal and shear velocities were measured using pulse echo technique at 4 MHz frequency at room temperature. Densities and the ultrasonic velocities of thermoluminescent glass were used for calculation of elastic properties such as longitudinal modulus, shear modulus, bulk modulus, Young’s modulus and Poisson's ratio. FTIR spectroscopy was measured in wave number range 400$-$4000 cm${}^{−1}$ to study structure of the glass samples. The result shows that the longitudinal and shear velocities of thermoluminescent glass increase with the increasing Cu${}_2$O. The density are not in significant correlation with Cu${}_2$O concentration in glass system. The change in elastic properties of the thermoluminescent glass depends on the concentration of Cu${}_2$O and can be confirmed by FTIR spectroscopy results.

Speaker: Mr Yutthachai Jaichueai (Department of Physics, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, THAILAND 34190)

1:00 PM The effect of ZnO on the kinetic parameters of thermoluminescence window glass exposed to photon irradiation

The present reports the preparation of ZnO doped commercial Thai transparent window glass provided by Gardian Industries Corp. (denoted as WG). The effects of variable concentration of ZnO on thermoluminescence (TL) behavior are studied . The sample were prepared by using the melt quenching technique. The glasses were cut into transparent chips and exposed to X-ray. Trapping parameters are calculated by glow curve shape method for every recorded glow curve. The glow curve structure, order of kinetics and activation energy are related to the concentration of the Zn-doped material. The concentration at 1.000 mol% of ZnO capable of reducing two peak glow curve of the window glass to a single peak.

Speaker: Ms Thanaporn Thumsa-ard (85 Sathonlamark Road, Warin Chamrap, Department of Physics, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190,Thailand)

1:00 PM The Equipment for Crystal Growth Based on the Hydrolysis Technique

With its unique electrical and optical characteristics, triglycinesulphate(TGS) has been studied extensively. However, the solution of glycine and sulfuric acid has the low evaporation rate, and hence, the long period is required to grow large TGS crystals. The main objective of this research is to investigate the potential of the electric-current stimulation to reduce the growth period of TGS crystals in the supersaturated solution.To grow TGS crystals, the solution was stimulated by the current of approximately 0.95 mA. The result shows that electric-current stimulation could reduce the growth period of the TGS to one third of that needed in the thermal crystal growth process. On the other hand, the FTIR spectra show that the stimulation might lead to the proton donation of the carboxylic group from glycines due to of the difference of the pH gradient between the electrodes. Thus, the reduced glycines might influence the formation of the electric domain in TGS crystals. In addition, the electrical and optical properties of the TGS crystal may be controlled by using this approach.

Speaker: Mr Chalermwong Dokpratoom (Department of Physics, Faculty of Science, Mahasarakham University, Mahasarakham, THAILAND 44150)

1:00 PM The Study of Fuel Pellet from Cassava

This research aims to study the cassava biomass fuel pellets prepared by cold compressed techniques with high pressure. Cassava chips were ground and sieved in the grain size of 150-300, 300-2000 and >2000 μm and are compressed with 8, 10, 12, 14 and 16 tons/cm${}^2$. The dimension of cassava fuel pellets is 4 cm in diameter and 1.5 cm in thickness. The results show that the heat of cassava fuel pellets, measured with bomb calorie meter, has a heating value of 3,790 Kcal/Kg, the compressive strength is correlated with the size and the pressure applied compressive cassavas were not significant. (The grain size of 150-300 and 300-2000 μm are compressed at high pressure from 10 - 16 tons/cm${}^2$, which show that they have high compressive strength.) The cost of fuel pellets is equal to 0.12 baht per pellets. In this research, the most effective of biomass fuel pellets is biomass fuel pellets which has grain size >2000 μm and with pressure of 16 tons/cm${}^2$ and biomass fuel pellets with minimum burn rate is biomass fuel pellets with grain size >2000 μm and with pressure of 16 tons/cm${}^2.$ Our results show that the fuel pellets made from this study have the potential to be used as a household fuel to substitute charcoal which is scarce and more expensive.

Speaker: Ms Wipakorn Rittisut (Department of Physics, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, THAILAND 34190)

1:00 PM The Study of Spin Seebeck Effect on Iron Alloy.

When a magnetized magnet is subjected to a temperature gradient, the difference types of electron spin are separated at both ends of sample. This phenomenon is called spin Seebeck effect (SSE). The tool for observing the SSE involves an inverse spin Hall effect (a conversion of spin current to charge current) by attaching a platinum stripe on the magnetic material. In this study, we observed the SSE in iron alloy materials. The magnetic property of a sample was studied by vibrating sample magnetometer (VSM). The platinum stripes were coated on a surface of iron alloy by lithography evaporation technique. The thickness of the platinum stripe was measured by atomic force microscope (AFM). The morphology of a sample was studied by scanning electron microscope (SEM). The magnetic field and temperature dependence on the SSE were studied. The results show that the saturation of a magnetized material is about 1000 Oe. The thickness of the platinum is about 10 nm. We applied a magnetic flied to the sample in range from 0 to 2500 oersted. The study of magnetic flied dependence on the SSE was found at the hot side in contrast to the cool side. The effects of temperature dependence on the SSE of the hot side and the cool side were clearly separated because the signals had opposite sign. However, in order to confirm the SSE on iron alloy, further studied need to be done to distinguish it from other contaminated signals such as Nernst effect.

Speaker: Mr Champ Suksawat (Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen, THAILAND 40002)

1:00 PM Thermal and Electrical Properties of P${}_2$O${}_5$-CaO-Na${}_2$O Glass Containing Ba$_{0.6}$Sr$_{0.4}$TiO${}_3$

Five different compositions of the system P${}_2$O${}_5$-CaO-Na${}_2$O containing 0, 10, 20, 30 and 40 mol% of Ba${}_{0.6}$Sr${}_{0.4}$TiO${}_3$ were prepared by the melt quenching method. The effects of composition on their thermal properties and dielectric properties were evaluated and discussed. The glasses were evaluated for glass transition temperature (Tg) and dielectric constant $\varepsilon$. The electrical and the thermal properties were also compared with theoretical data. Tg of the glasses varied between 450 and 530${}^{\circ}$C.The dielectric constant ranges from 6 to 9 and a dielectric loss of 0.0012 at 4.8 GHz, which provide an attractive feature for microwave applications.

Speaker: Ms Pratthana Intawin (Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai, THAILAND 50200)

1:00 PM WS2 Nanoparticles and Multiwalled Carbon Nanotubes Counter Electrode for Dye-sensitized Solar Cells

WS${}_2$ nanoparticles and multiwalled carbon nanotubes (MWNTs) were hydrothermally prepared and used as a counter electrode (CE) for dye-sensitized solar cells (DSSCs). The highest energy conversion efficiency of 6.69 % was achieved from the produced WS${}_2$/MWNT CE, closely comparable to that of the Pt CE which was 7.34 %, whereas the pure MWNT based DSSC gave the efficiency of 5.2 %. The WS${}_2$ nanoparticles therefore played a crucial role in this enhanced cell efficiency. This superior efficiency was attributed to the combination of the high catalytic activity of the WS${}_2$ nanoparticles and the high electric conductivity of the MWNTs, which were investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurement, respectively.

Speaker: Ms Ladavan Kaewphaisan (Materials Science and Nanotechnology Program, Faculty of Science, Khon Kaen University, Khon Kaen, THAILAND 40002)

1:30 PM → 2:30 PM Physics Education (APRU)

1:30 PM Teaching Physics, Conservation Laws First

Speaker: Prof. Eric Mazur (Harvard University)

3:15 PM → 3:30 PM Break

3:15 PM → 4:15 PM Nuclear and Radiation Physics

3:15 PM Modelling and experimental investigations of irradiation effects in Si radiation detectors

This talk is aimed at presenting an overview of Si radiation detectors. and how different types of radiation influence the short and long term electronic properties and detector performance. The scope of this work is under a Co-ordinated Research Project entitled “ Utilization of ion accelerators for studying and modelling of radiation induced defects in semiconductors and insulators” funded by International Atomic Energy Agency. In particular, I will focus on the activities related to the following aspects: 1. Theoretical modeling and simulation of the device performance: Using commercial device simulation software entailing an electrostatic model using the Poisson and continuity equations. the device parameters such as doping profile, depletion voltage, plots, electric field and potential plots, C-V plots, leakage currents, effect of guard rings, are determined. Such simulation and intercomparison with experimental studies helps in failure assessment of radiation induced damage. 3. Optical protocols for characterization of ion-induced defects: Defects such as oxygen-related vacancies and self-interstitials are inherent in as-grown wafers and are also formed by material processing/irradiation/ and which impact device performance. The use of contactless optical probes to study the formation and annihilation of defects as a result of irradiation will be demonstrated. The overall objective is to disseminate information on radiation effects in Si and other related materials, with a view of motivating undergraduate and Master’s students projects/activities in related areas.

Speakers: Abhay Nayak (St. Stephens College, University of Delhi, Delhi-110007, INDIA), Shyama Rath (Department of Physics and Astrophysics, University of Delhi, Delhi-110007, INDIA)

3:45 PM Neutron spectrometry for radiation protection purposes

Reliable knowledge of the neutron energy spectrum is valuable for determination of neutron dose equivalent for radiation protection purposes. The reasons are twofold: First, neutron dose equivalent depends strongly on the neutron energy spectrum and, second, most of neutron measuring devices are highly energy dependent. Recently, we have developed a neutron spectrometer for measurement of neutron energy spectra in the energy range from thermal energy up to several tens of MeV. The spectrometer is composed of a 3He proportional counter and several cylindrical neutron moderators made of high-density polyethylene. Each of the measurement values represents the convolution of the spectrometer’s energy response function and the neutron spectral fluence under study. In this development, the energy response of the spectrometer was characterized using the Monte Carlo radiation transport code PHITS (Particle and Heavy Ion Transport System), and the deconvolution algorithm for extracting the neutron energy spectrum from the measurement values was developed under MATLAB (Mathwork, Inc.). The detail of the spectrometer development and its application in neutron metrology and radiation protection in workplaces near the research reactor and high-energy medical linear accelerators will be presented.

Speaker: Dr Thiansin Liamsuwan (Thailand Institute of Nuclear Technology (Public Organization), Ongkharak, Nakorn Nayok 26120, Thailand)

4:00 PM Design of a BSA for Producing Epithermal Neutron based on D-T Neutron Source for BNCT

Particle and Heavy Ions Transport code System (PHITS) is used to simulate capability to produce an epithermal neutron flux for BNCT of various beam shaping assembly (BSA) designs. It is assumed in this work that all designs of BSA considered is a cylindrical geometry. It is found that by adopting the flux of 14.1 MeV neutrons from a D-T neutron generator, the design that yields an optimum output is the BSA design with $^{238}$U as multiplier, AlF$_3$ as moderator, Pb as reflector, Al$_2$O$_3$ as fast neutron filter, Li as thermal neutron filter, Ni as gamma shield, and Bi as collimator, in which the out coming of the proposed BSA at the beam port can satisfy the criteria for boron neutron capture therapy (BNCT) from the International Atomic Energy Agency (IAEA). It is also found that the output of the proposed design is better than the output of other BSA designs, such as those reported by Eskandari and Kashian [1], Rasouli et al. [2] and Rasouli and Masoudi [3]. In addition, no thermal neutron is found at the beam port of the proposed design. [1] Eskandari M R and Kashian S 2009 *Annals of Nuclear Energy* **36** 1100-1102 [2] Rasouli F S, Masoudi S F and Kasezas Y 2012 *Ann. Nucl. Energy* **39** 18 [3] Rasouli F S and Masoudi S F 2012 *Appl. Rad. Isotopes* **70** 2755

Speaker: Ms Muharani Asnal (School of Manufacturing Systems and Mechanical Engineering, Sirindhorn International Institute of Technology, Thammasat University, Pathum Thani, THAILAND 12121)

Slides SPC_2015.pdf SPC_2015.ppt

3:30 PM → 4:30 PM Thai National Astronomy Meeting 2015 (TNAM 2015)

4:15 PM → 4:30 PM Accelerators and Synchrotron Radiations

4:30 PM → 5:00 PM Closing ceremony

Fri, May 22

8:00 AM → 6:00 PM Excursion