The purpose of this work is to study and develop a forward modelling computer program of 2D seismic wave by using finite-difference method. Forward modeling is a method that shows how seismic wave propagates through particular subsurface area, and also one of the schemes in Inversion method which is used for modeling the prospect area from the acquired seismic field data. Despite the fact that...
The qualitative and quantitative study of gunshot residue (GSR) obtained from M16 and AK47 rifles are reported. The GSR samples were collected from various different sources of the shooter (hand, cloth, and helmet), elapsed time, and number of shooting. The scanning electron microscope with electron dispersive X-ray spectrometry (SEM/EDS) showed that the various shapes and sizes of the GSR...
A novel polymer composite material with high stiffness and thermal endurance can be designed by optimizing the filler content. We investigated the microscopic properties of the interfacial regions between cis-polyisoprene (natural rubber) and carbon-based fillers, e.g. fullerenes by using classical molecular dynamics (MD) simulations. The microscopic analysis shows that increasing filler...
In this work, we discussed about our construction of a portable flat vacuum cell and our study of the effect of surface adsorption in the cell in which thermal atoms were trapped. The cell comprised two parallel glass plates that were separated by a narrow gap in order to accentuate the dominance of collisional frequency along the glass surface’s normal. The identification and measurement...
This study aims to investigate the elemental compositions in 50 Thai rice samples using instrumental neutron activation analysis (INAA) and to identify rice according to their types and rice cultivars using statistical analysis. As, Mg, Cl, Al, Br, Mn, K, Rb and Zn in Thai jasmine rice and Sung Yod rice samples were successfully determined by INAA. The accuracy and precision of the INAA method...
Standard cosmological model containing barotropic fluid in arbitrary spatial curvature and scalar field under arbitrary potential can be described in the form of non-linear Schr\"{o}dinger (NLS) formulation. The formulation leads to the simpler way in obtaining exact scalar field solutions. NLS may be useful for interpretation of wave function in quantum cosmology.
This research aims to study hydrogen alpha emission, corresponding to star formation of galaxies in the NGC 4213 group that has an average recession velocity of 6,821 km/s. The imaging observations with broad-band filters (B, V and R$_\text{C}$) and narrow-band filters ([S II] and Red-continuum) were carried out from the 2.4-m reflecting telescope at Thai National Observatory (TNO). There are...
A two-qubit system is studied in the quantum operator formalism to analyze the open system consisting of two atoms in a cavity. The evolution of an open system is usually described in the Kraus representation which is constructed by considering a large closed system. In this work, we consider the short time scale of the evolution of systems in terms of interaction Hamiltonian. We focus on the...
This research was aimed to study the period variation rate of V1292 Taurus RR Lyrae variable star. The observational data was obtained on 0.5 meter Reflecting Telescope with CCD photometer camera in (Blue light, B) and (Visible light, V) bands at Regional Observatory for the Public, Nakhon Ratchasima province. The data have been analyzed to plot the light curves. From the...
In this research, engine emissions from different vehicle age, type and used fuel in Amphoe Muang Lampang in Thailand were measured and studied with a portable gas combustion analyzer. Concentrations of carbon monoxide (CO), carbon dioxide (CO2), oxygen (O2), nitrogen oxides (NOx) and sulfur dioxide (SO2), as well as exhaust gas temperature (flue temperature, FT), net calorific efficiency...
In this work we will present the analysis results of the explorer-0 chips which have been irradiated by 5.9 keV X-ray from $^{55}$Fe sources. The explorer-0 chip is a prototype CMOS imaging sensor designed for new Inner Tracking System of ALICE detector. Here we focus on four important parameters, the pixel pitch, the collection electrode size, the distance between the electrode and the...
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. A light curve of V2790 Ori was analyzed using program Maxlm DL4 and its period change was also calculated. The result revealed that the orbital period of V2790 Ori was continuously...
IrMn alloy has been intensively studied during last few years in order to improve exchange bias strength in magnetic storage. IrMn layer is usually coupling with a ferromagnetic layer to increase sensitivity in magnetic sensor due to its critical thickness. It can maintain high exchange strength even at ultra-thin layer. In this study, thermal annealing was performed at different temperatures...
As an excellent source of nutrients, riceberry has gained more intention than white rice. However, information of instant rice obtained from riceberry is scarce. An alternative technique of instant rice preparation was therefore proposed in this work. The combined gas-fired infrared burner and air convection drying at different gas-fired infrared burner intensities was investigated. Gas...
The upper Chao Phaya Basin is the largest Cenozoic sedimentary basin that is located in the upper central part of Thailand. The basin is a high potential area for agricultural activities, such as growing rice, sugarcane and vegetables. In each year, the groundwater level has decreased continuously about 10-30 cm/year. Groundwater levels dropped from 5-10 m. to 10-25 m below ground surface at...
Atmospheric water vapor is a crucial component of the Earth's atmosphere, which is shown by precipitable water vapor. It is calculated from the upper air data. In Thailand, the data were collected from four measuring stations located in Chiang Mai, Ubon Ratchathani, Bangkok, and Songkhla during the years 1998-2013. The precipitable water vapor obtained from this investigation were used to...
Jupiter’s polar emission, whose brightness behavior appears to be unstable. This work focuses on the bright spot in active region which is a section of Jupiter’s polar emission. Images of the aurora were taken by Advanced Camera for Surveys (ACS) on board the Hubble Space Telescope (HST). Previously, two bright spots, which were found on May 13th 2007, were suggested to be fix on location...
A thermionic RF-gun is an essential component in electron injector for producing a quality electron beam for a THz radiation source at Plasma and Beam Physics Research Facility, Chiang Mai University. The RF gun consists of one and a half normal conducting resonant cavities and a side-coupling cavity which operates in pi/2-mode at frequency of 2856 MHz. In 2014, the gun design was improved by...
In the wood production manufacturing process, there are a lot of wood scraps must be left to waste. To product a pole from the wood scrap, which help to reduce cost in the production, is to use the wood scrap more efficiently. In this work, the wood poles were be designed, constructed and tested from teak and Para wood scrap by using finger joint with Polyvinyl Acetate. To constitute of these...
This research study Calcium oxide synthesis from cockle shells for catalyst in biodiesel production from palm oil. The shells are calcium is transformed into calcium oxide. This is a powerful catalyst for the transesterrifcation reaction. The research was burned cockle shells at 900 °C for 5 hours. The ratio of methanol : oil is 9 : 1 molar. The temperature reaction at 80 °C for 30 minutes....
Cesium iodide doped with Thallium (CsI:Tl) is one of the most materials used for radiation detector applications. In this work, the CsI:Tl crystals that made from the material sources with different precursor purity were investigated by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Raman scattering, UV-Vis spectroscopy and...
We report here the use of machine vision and support vector machine for automatic identification of Glutinous rice RD6. This project is motivated from the problem of maintaining purity of RD6 seed stock, since they can mutate back to its parent KDML105. Seed stock is needed to be checked to ensure that contamination percentage does not exceed the excepted value. We use flat bed scanner to...
The aim of this work was to compare characteristics of hydroxyapatite synthesized by precipitation and ball milling techniques. The cuttlefish bone powder was a precursor in calcium source and the di ammonium hydrogen orthophosphate powders was a precursor in phosphate source. The hydroxyapatite was synthesized by the both techniques such as precipitation and ball milling techniques. The phase...
The NMR signal transmission system at earth magnetic field was constructed. The system consists of 5 important components: Arduino Mega 2560 microcontroller, frequency generator module (DDS synthesizerAD9850), switching integrated circuit (DG419), operational amplifier (THS3001) and audio-power amplifier. The microcontroller was programmed to receive the pulsed width values from computer and...
Soil is heterogeneous medium which consist of liquid, solid and gaseous phases. Natural soils of various types have different electrical properties due to the composition, structure, water content, pH and temperature. This research aims to study the correlation of electrical resistivity for predicting pH of lateritic soil. The samples of soil were collected from farm of Kasetsart University...
This research studies on the nature of aurora feature on Jupiter, especially the aurora that connects to its satellite, Io. Jupiter has a large magnetosphere, as a result of strong magnetic field strength. This magnetosphere corotates with Jupiter and extends over all of Galilean satellites. The interaction between Jupiter’s rotating magnetic field and Io cause plasma particles to flow along...
CuFeO$_2$ is a metal oxide mineral material which is called delafossite. It can potentially be used as a chemical catalyst, and gas sensing material. There are methods to fabricate CuFeO$_2$ such as chemical synthesis, sintering, sputtering, and chemical vapor deposition. In our work, CuFeO$_2$ is prepared by Fused Deposition Modeling (FDM) 3D printer. The composite filament which composed of...
Bangkok is located on the soft marine clay of the Lower Chaopraya Basin which can amplify seismic wave and affect to building shaking. Shallow shear wave velocity to depth 30 m. (V$_s$30) is widely studied recently but data of deeper layer to bedrock still absent. The missing data are useful for earthquake engineering design and ground shaking estimation.
This study aims to measure deep shear...
The general high temperature furnaces are usually used in the atmosphere, a sample it consequently contacts the air that has pollutants, there makes the sample impure by exposure in a particular way to be not required and difficult to control gas that requires to an interaction within a sample. A heating technique in a vacuum environment is required to fix the referred problems. The purpose of...
This work was aimed to design and construction of portable survey meter for radiation dose measuring. The designed system consists of 6 parts including GM-tube radiation detector, low voltage power supply, high voltage power supply, pulse conditioning, processing and display on android phone. The test results indicated that the ripple voltage of low and high voltage power supply were less...
Transverse emittance of a charged particle beam is one of the most important properties that reveals the quality of the beam. It is related to intensity, size and angular displacement of charged particles in transverse phase space. There are several techniques to measure the transverse emittance value. One of a practical method is the pepper-pot technique. This research concentrates on...
The $\omega-\phi$ mixing plays an important role in particle interactions involving vector mesons. The SU(3) flavor symmetry predicts the flavor mixing in vector meson nonet. The $\omega-\phi$ mixing angle was predicted by several physical processes, such as decay rate, radiative decay of $\omega$ and $\phi$. In this work, we calculated vector meson masses by using chiral Lagrangian at leading...
In present day, rainfall estimation by weather radar is widely used. Meteorologists use various z-r relationships to appropriate rainfall estimation for different study areas which have different factors such as topography, climate, rain pattern, types of clouds, etc. This research aims to determine the appropriate altitude of radar reflectivity (Z-Level) to provide accurate rainfall...
This research aims to investigate the relationship between atmospheric carbon dioxide (CO2) concentrations, traffic count, vehicle type and meteorology at three study sites in Amphoe Muang Lampang in Thailand. Initial measurements were conducted since December 2016 from 2:00-4:00 PM. Since CO2 concentrations also depend on biospheric processes (photosynthesis and respiration), the chosen...
This research project has developed electrospinning system for performance increasing of the system. Operating system was changed from the computer controlled to command on the machine and status of system show on display on LCD screen. Moreover, this research has developed working control programs with Arduino board. Component of electrospinning system are source of voltage, flow rate control...
This research focuses on design and development of beam diagnostic system of an electron linear accelerator (linac) for natural rubber vulcanization at the Plasma and Beam Physics Research Facility, Chiang Mai University. The main components of the accelerator include a DC thermionic electron gun and an S-band standing-wave linac. The system will be used to produce electron beams with...
We developed a measurement system for collecting and analyzing the fringe pattern images from a gauge block interferometer. The system was based on raspberry pi which is an open source system with python programming and opencv image manipulate library. The images were recorded by the raspberry pi camera with 8 mega pixel capacity. The noise of images was suppressed for the best result in...
The main objective of this work is to synthesized Zn0.96Al0.04O thermoelectric materials for fabrication thermoelectric modules and invention thermoelectric generator. The Zn0.96Al0.04O sample was prepared by a conventional solid state reaction method. The formation of structure was proved by X-ray diffraction and the thermoelectric properties were measured. The results showed that the...
Jinda Sinlapanuntakul, Puchong Kijamnartsuk, Chanthawut Jetjamnong, S. Chotikaprakhan
Department of Physics, Faculty of Science, Kasetsart University, Bangkok, 10900 Thailand.
Keywords: Digital lock-in amplifier, RLC circuit, Physics laboratory.
The purpose of this paper is to develop a digital lock-in amplifier based on soundcard interface for undergraduate physics laboratory. Both series...
Eclipsing binaries with pulsating components are very crucial objects for asteroseismology. We present the results of an analysis of photometric time series observations for the intermediate-age open cluster NGC 2126 acquired during the years 2004, 2013 and 2015 with the aim to detect new variable stars and to study binary systems. The CCD photometric light curves in V band of the eclipsing...
The mechanical properties of cementitious materials, widely applied in construction, could be improvedby reinforcement with cellulosic natural fibres. In this study, another type of natural fibers, i.e. the bacterial cellulose (BC) obtained from coconut jelly (nata de coco) was added to cement paste to form the reinforced composites. The coconut jelly was thoroughly washed and blended prior to...
Geopolymer is an environmental friendly construction material which has a potential for replacing cement. In the present study, the addition of carbon fiber and nano-silica in geopolymer paste was studied in terms of the electrical and mechanical properties, and the microstructure. The geopolymer paste was made from fly ash by blending it in Na$_2$SiO$_2$/NaOH solution using the liquid/ash...
Molecular dynamics simulations of Cationic ions in mud and Laterite, indigo blue molecules and cotton molecules have been carried out to investigate effect of Cationic ions to indigo blue interactions. The results show that appearances of cations improve both indigo blue - indigo blue interaction and indigo blue - cotton interaction. This result obey the experimental results.
Recycled borosilicate glass (RBSG) was used a composition in 80RBSG–20Na2O glass systems doped with different transition metal oxides (TMOs) (where TMOs = V2O5, Cr2O3, CuO, ZnO, ZrO2, Ag2O and CdO). The ultrasonic velocities (both longitudinal and shear) of glass systems were measured by using pulse echo technique. Measurements were carried out at 4 MHz frequency at room temperature. The...
In this work, the stock price variation in a form of dynamic hysteresis was investigated via Monte Carlo simulation. The Ising spin Hamiltonian was considered as the level of ‘disagreement’ (in the social economic) which has to be minimized for the market sustainability. The Ising spin directions (either +1 and -1) were considered to refer to an agent’s intention to perform his action on...
Lightweight aggregates were prepared from fly ash of by-products from the paper industry. The influence of the ratio of clay to fly ash and processing conditions on lightweight aggregates properties were investigated. It was found that the amount of fly ash directly affected to porosity of lightweight aggregates. Lightweight aggregates with the ratio of clay to fly ash at 80:20 wt% using the...
The synthesis of Mg$_x$Fe$_{(3-x)}$O$_4$, X = 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 and 0.9 was performed by solid state reaction with various rotating speed of ball milling (160, 240 and 320 rpm). Samples were characterized by X-Ray diffraction (XRD), scanning electron microscopy (SEM). Shrinkage and Vickers were used to determine the phase structure, physical properties and mechanical...
This research studied about reduction of void under die in die attach process. Die attach process is one that is very importance process in the integrated circuit(IC) packaging. A popular adhesive material used for attaching between die and leadframe or substrate of a package which is an epoxy. Snap cure process is also important to make a completed epoxy due to cross linking to enhance...
We study the Josephson effect in a gapped graphene-based superconductor/barrier/superconductor junction as using the Dirac-Bogoliubov de Gennes (DBdG) equation for theoretical prediction. A massive gap of this regime is induced by fabricating a monolayer graphene on substrate-induced bandgap and superconductivity is acquired by the proximity effect of conventional superconductor (s-wave...
This research studied about effecting aging time of epoxy molding compound (EMC) that effect to reliability performance of integrated circuit (IC) package in molding process. Molding process is so important of IC packaging process for protecting IC chip (or die) from temperature and humidity environment using encapsulated EMC. For general molding process, EMC are stored in the frozen at 5...
We proposed a method to calculate the effective capacitance of a metallic single-electron transistor using the quantum Monte Carlo method to describe the Coulomb blockade effect. The effective capacitance depended on the induced gate charge, temperature, and conductance of the system. Furthermore, the results can be used to calculate the effective charging energy, which can characterize the...
Effects of an intermediate cubic GaN (c-GaN) buffer layer on structural and optical properties of AlN films on MgO (001) substrates via radio frequency plasma assisted molecular beam epitaxy (RF-MBE) were investigated with Raman scattering, X-ray diffraction, and UV spectroscopy. The samples studied in this work are AlN films grown under Al-rich condition with and without intermediate c-GaN...
Two-dimensional (2D) material is a specific type of materials with its thickness being thinned down to single atomic layer. In many materials, their 2D sheets have been reported to yield very different physical properties from those of their ordinary bulk and other forms of nanostructures. For instance, the band gap of 2D semiconductor sheets can vary from zero band gap (semi-metals, e.g.,...
This research studied about electricity cogenerator from Hydrogen and Biogas and the factors that cause that effecting Hydrogen from Aluminum which was a cylindrical features. By using a catalyst was NaOH and CaO, it was reacted in distilled water with percentage of Aluminum : the catalyst ( NaOH and CaO ) : the distilled water, which were 2 : 8 : 1, respectivety. And the percentage of...
Teerayut loylip1,2*, Suwicha Wannawichian2,3
1Graduate School, Chiang Mai University, Chiang Mai, Thailand
2National Astronomical Research Institute of Thailand (NARIT), Chiang Mai, Thailand
3Department of physics and Materials Science, Chiang Mai University, Chiang Mai, Thailand
E-mail: teerayut@Narit.or.th
Abstract
A meteorite is a fragment of iron, stone or stony–iron rock. The...
The Nelson-Seiberg arguments of the connection between supersymmetry breaking and R-symmetry breaking is determined for gauged and localized supersymmetry theories with generic superpotential. This is a study of symmetry breaking in supergravity theory. The metastable vacua of supergravity from the contribution of F and D auxiliary fields in superpotential are determined, and also anti-de...
Polycrystalline Ca$_{12}$Al$_{14}$O$_{33}$ (C12A7) were synthesized by conventional solid state reaction method and were calcined/sintered at 1300˚C. The Mg powder was used to reduce oxygen inside of nano-cage to form free electron in the cage for enhancing the electrical and optical properties of C12A7 cement compound. The crystal structure of the C12A7 and Mg-reducing C12A7 were...
Excitonic solar cells (XSC) based on heterojunction nanostructure composed of low-dimensional materials have gained a great deal of interest due to its large interface area and hence the high possibility in generating excitons. In general, the power conversion efficiency (PCE) of this XSC depends strongly on the interface band alignment between donor and acceptor materials. Therefore,...
Transparent conducting oxides (TCOs) are widely used for many applications. Typically, most of TCOs are intrinsically n-type semiconductors and are difficult to be doped for p-type conductivity. The spinel ZnRh$_2$O$_4$ has been recognized as a potential p-type TCO. In this work, we present energetics and electronic properties of native defects including vacancy, interstitial and antisite...
Neutron monitors (NMs) are ground-based detector designed to measure the cosmic ray (CR) intensity, sometimes observe a sudden reduction in galactic CR intensity, the so-called Forbush decreases (FDs) event. The Princess Sirindhorn NM (PSNM) was established in 2007, an NM64-type and 3 bare tubes located at the world's highes geomagnetic vertical cutoff rigidity 16.8 GV was installed at Doi...
In standard magneto-optical trap (MOT), three pairs of cooling beams orthogonally intersect at the magnetic field minimum produced by anti-Helmholtz coils. The degree of off-centering seriously determines the trapping velocity, lowest temperature reached, decoherence time, and the shape and density of the cold atomic cloud. Our alternative two-beam trap was designed for efficiently cooling and...
The gamma-ray attenuation coefficients of strontium–lead–silicate glasses have been measured by using a narrow beam transmission technique for gamma ray photon energies at 122, 662, 1173 keV and X-ray attenuation technique for gamma ray photon energies at 74.228 keV. These coefficients were then used to obtain the values of mass attenuation coefficients and half value layer. In order to...
We investigate coherent single photon in the infrared regime traveling in the positive z direction passing through a single layer of strained graphene. The angle of rotation relates to space deformation by the terms of directional dependent fermi velocity. Analytical expressions of full quantum mechanics, by second-quantization approach, are obtained for components of the magneto-optical...
Sb-single doped rutile-TiO$_2$ (STO) ceramics were prepared by a conventional mixed oxide method. The high-dielectric performance with giant dielectric constant value ($\epsilon$'$\approx$10$^4$) with low dielectric loss (tan$\delta$<0.05) of STO ceramics over a wide temperature range were obtained. Scanning electron microscope coupled with energy-dispersive X-ray analysis (EDX) and X-ray...
Alcohols are solvents for organic and inorganic substances. Kinematic viscosity of liquid is important transport properties. In this study model for estimating n-alkane-1-ol kinematic viscosity are correlated to the Martin’s rule of free energy additivity. Data available in literatures are used to validate and support the proposed equations. The kinematic viscosity of n-alkane-1-ol can be...
The hadronic products that result from proton-proton collisions at the Large Hadron Collider (LHC) can give rise to jet formation that can be detected be the Compact Muon Solenoid (CMS) detector. Several interesting physics, both Standard Model (SM) and Beyond Standard Model (BSM), processes can result the final states with charm quark jets. Analyzes rely on the algorithms that try to identify...
The Nelder-Mead method or Simplex algorithm was proposed in 1965 by John Nelder and Roger Mead. It is widely used to fi?nd minimum values of speci?c functions in Mathematics and Physics. We implemented a framework for minimization algorithm
in C++ based on the non-parallel Simplex scheme and a parallel adaptation. For the
parallel simplex algorithm, we used the Message Passing Interface (MPI)...
The reductive perturbation technique is applied to obtain the dust acoustic wave equation from the governing equations for dust grains in plasma. Some electrons and ions can be trapped in the charged dust potential and the populations of these two particles will be described by the Maxewellian distribution. The growth rate can be determined by applying a long-wavelength perturbation to the...
We report the differences in light stable isotopes between two kinds of Thai rice (Thai jasmine and Sung Yod rice). Thai jasmine rice and Sung Yod rice cultivated in the northeast and the south of Thailand. Light isotopes including 13C, 15N and 18O of Thai jasmine rice and Sung Yod rice samples were carried out using isotope ratio mass spectrometry (IRMS). Thai jasmine rice (Khao Dawk Mali...
Wavelet analysis is an excellent technique for data processing analysis based on linear vector algebra since it has an ability to perform local analysis and is able to analyze an unspecific localized area of a large signal. In this work, the wavelet analysis of cyclic waveform was investigated in order to find the distingue feature from the cyclic data. The analyzed wavelet coefficients were...
Graphene oxide (GO) is graphene sheet laced with oxygen-containing functional groups that located at edge of the lattice. The properties of GO can be modified depending on the degree of reduction of oxygen-containing functional groups. Typical methods to reduce GO include wet chemical processes and thermal annealing in which hazardous chemical substances and high temperature are applied. In...
We present a portable device for long-time recording of the temperature at multiple measuring points. Thermocouple wires are utilized as the sensors attached to the objects. To minimize the production cost, the measured voltage signals are amplified and sequentially relayed via a multiplexer to a single microcontroller. The observed temperature and the corresponding date and time, obtained...
In this work, magnetic force microscopy (MFM) was utilized to observe the magnetic write head remanence, which is the remaining out-of-plane magnetic field on magnetic write heads after a write current is turned off. This remnant field can write unwanted tracks or erase written tracks on a magnetic media. The write head remanence can also occur from device and slider fabrication, either by...
One of significant problems limiting the performance of perpendicular magnetic write heads is wide adjacent track erasure (WATEr), causing stored data near and also far from a written track being erased. Understanding WATEr mechanisms and its locations is crucial both for design and process engineers. Typically, the presence of WATEr in magnetic write heads is monitored using a spin-stand...
This research studies the material’s properties which aim to analyze and evaluate the appropriateness of selection the material for repairing propeller shafts of fishing boats. The materials’ preferential ranking is used as the method of study, which uses the criterion of materials’ properties, including mechanical properties and chemical properties, as an assessment tool. The result of...
One of critical beam parameters for a linear accelerator is a beam energy. This research studies on measurements of energy and energy spread of electron beams produced from a thermionic cathode RF electron gun at the Plasma and Beam Physics Research Facility, Chiang Mai University. An alpha magnet is used for energy filtering by using energy slits located inside the alpha magnet vacuum...
Electrical double probe measurement is one of the techniques used to find plasma parameters. Plasma parameters which electrical double probe can determine are electron temperature and electron density. Plasma parameters can be extracted from I-V characteristic graph of double probe which is inserted inside plasma. A program which is responsible for all calculations and control are written in...
Fabrication of perpendicular magnetic recording heads in hard disk drives involves many processing steps and control parameters. One of the control monitors is side wall angles of the write pole tip which is typically measured by a scanning electron microscope (SEM). SEM observation is, however, a destructive testing as magnetic recording heads were damaged by electron bombarding. This paper...
The aim of this research was to study mechanical and physical properties of epoxy composites reinforced by the fibers of banana were analyzed. Three different specimens were made by varying the species of Musa ABB CV. Kluai “Namwa”, Musa balbisiana Colla.at and Musa (AAA group) "Kluai Hom thong" at 12% by weight. Specimens were formed by hand-layup process. The tensile strength, tensile...
Cement is a very important material for building and construction but the main drawback is its brittleness due to high porosity. The brittleness of cement was found to be improved by reinforcing the cement matrix with celluloses extracted from plants. In present work, we studied another type of natural cellulose produced by bacteria, i.e. bacterial nano-cellulose (BNC). The BNC was obtained...
In this work, the cubic GaN with AlGaN interlayers was selectively grown on the [110]-stripe patterned GaAs (001) substrate by metal organic vapor phase epitaxy (MOVPE). Since the cubic phase of GaN is meta-stable and hexagonal phase always exist, the structural phase and features of the film were investigated by micro-Raman spectroscopy and scanning electron microscopy (SEM), respectively....
Hydroxyapatite-ZrO$_2$ composite ceramic were synthesized using a thermal precipitation techniques. The chemical precursors were prepared from di-ammonium hydrogen orthophosphate, calcium oxide (CaO) derived from chicken eggshell, zirconium dioxide (ZrO$_2$) and distilled water. The mixture were heated at the various temperatures from 100 to 700$^o$C in the furnace with an incremental...
In this work, the disease spreading under the framework of SIS (susceptible-infected-susceptible) compartment model was investigated using the magnetic Ising model, the stochastic Monte Carlo simulation, and the knowledge based Neural Network analysis. The defined systems were lattice-like and varied in sizes to observe the finite size effect, where the agents (either susceptible or infected)...
The study on measurement of moisture content in paddy rice by capacitance method, using the principle of physics is capacitance that relate with dielectric of water. The study use IC555 frequency circuit for measure moisture content. We put the paddy rice in parallel plates that replace a capacitance in circuit. The frequency will change follow by capacitance of paddy rice, by the way if the...
Monte Carlo (MC) samples are the essential components for almost all particle physics related experimental analyses. These samples are widely used for the preparations of physics analyses and for predictions regarding future experiments. The MC production for a large-scale experiment like CMS is a huge effort in which billions of simulated events for thousands of individual physics processes...
Galactic cosmic radiation emanates from outside the solar system, while occasionally a disturbance in the sun’s atmosphere leads to a surge in radiation particles.
Protection is provided by the sun’s magnetic field, the earth’s magnetic field, and the earth’s atmosphere. Dose rates are dependent on the altitude, the geomagnetic latitude and the solar cycle. For occupational exposure to...
This research studies the characteristics of local earthquakes occurring in the northern Thailand during the year 2006 to 2015. 780 seismic events (ML ≥ 0.1) are recorded and analyzed from densed seismic networks in Thailand. Seisan earthquake analysis software was used to calculate the magnitudes and to relocate the earthquake locations with the seismic velocity model of Thailand (TRF,...
We present a home-built sensor for measuring the soil moisture along the depth. The sensor is constructed as a vertical stack of hollow cylindrical capacitive probes, each of them separated by very thin insulators. For long-term usage purposes, the probes are equipped in a plastic tube so that they are not contact to the soil samples. At each depth position, the soil moisture is measured by a...
We present and analyze phase portraits of dynamical scalar field of Non-Minimal Derivative Coupling Gravity model in Palatini formalism.
This study did observation of Geostationary Equatorial Orbit (GEO) satellite above Thailand’s sky by 0.7-meter telescope at Inthanon Mountain, Chiangmai, Thailand. The observation took place 14 nights with Sidereal Stare Mode (SSM) in which the moving object will show during the streak detection. The star identification for image calibration is based on a star catalogue. The streak detection...
A new type of canonical transformations for the multiplicative Hamiltonian, which considered as a 1-parameter: $\lambda$-extended class from the standard additive form of the Hamiltonian, was found and called $\lambda$-extended class of the standard canonical transformations. The $\lambda$-extended canonical transformations could be treated as a generating function to produce an infinite...
The study of orbital element of Asteroids (in Cometary Orbits, ACO) is based on images taken by 0.7 m diameter telescopes to find position of asteroids and calculate their orbital elements. This work focuses on variation of position and orbit shape of ACO, which are obtained by analyzing orbital element and Minimum Orbital Intersection Distance (MOID). Each observation, those parameters are...
The temperature control system was designed and built for application in dielectric spectroscopy. It is based on dual-stage Peltier element that decreases electrical power and no cryogenic fluids are required. A proportional integral derivative controller was used to keep the temperature stability of the system. Temperature of the system was measure by a Pt100 temperature sensor. Effect of...
Nanocomposite piezoelectric films based on the blend of poly(vinylidenefluoride-hexafluoropropylene) (PVDF-HFP) and magnesium chloride hexahydrate (MgCl$_2$•6H$_2$O) have been investigated in this work. The films incorporated with 0.5 wt% MgCl$_2$•6H$_2$O were prepared using a solution casting technique and uniaxially stretched at various ratios from 2 to 6 times in order to characterize phase...
This report studied the necessary condition to obtain different phase of synthesized CaCO$_3$ and their corresponding electrical properties. The precipitation with varied reaction temperature was performed, and the structure of product was determined by using x-ray diffraction and scanning electron microscope. The micrograph of derived CaCO$_3$ was observed as rice-grain structure as reaction...
Mg-IV-N$_2$ semiconductors, with the group-IV (Si, Ge, and Sn), are alternative materials beside a series of III-N, e.g. AlN, GaN and InN, which is used widely for optoelectronic devices. This work presents phonon frequencies, Born effective charges and longitudinal optical - transverse optical (LO-TO) splitting of these compounds at gamma point by using the density-functional perturbation...
In this paper, we present using photometric data study to derive an Hertzsprung - Russell (HR) diagram for the spectral types of open cluster M35 (NGC 2168). Astrophotography data of M35 observation with a telescope prompt 8 at Chile. Download 10 photo images data of the blue and visual filter from Skynet Catalog, then the photos will be reduction to eliminate noises in order to use stack...
Recurrent novae (RNe) are novae with multiple recorded outbursts powered by a thermonuclear runaway. This occurs on the surface of the white dwarf in a close binary system in which a late type main-sequence or giant secondary star is filling its Roche lobe and transferring material onto the white dwarf primary star. They resemble classical novae (CNe) outbursts in several aspects and by...
This research was conducted to find out the pattern of the lunar mansions from the position change of the Moon. These positions were called as the lunar mansions. The lunar mansions have 27 groups with important 27 fixed stars. The Moon’s position was calculated from nearby stars by cosine formula. The smallest angular separation between the Moon and the fixed stars was the lunar mansion of...
In this study, Potential increasing of rubber sheet production with fungus displacement by solar tunnel dryer. By integrating a biomass gasifier as an assisting heat source for drying Rubber Sheet produce and its performance analysis has been investigated. Experimental study has been carried out with the stand-alone solar tunnel dryer and the dryer with the assisted biomass gasifier.
For...
We study the preheating process in the universe after inflation for the inflationary model in which the coupling between the inflaton and the matter scalar field is a result of disformal transformation. We find that the disformal coupling between inflaton and matter scalar field can lead to efficient preheating process.
Platinum (Pt) counter electrode was coated by electrochemical method as high surface area and abiding adhere to substrate. Electrochemical system consist the dc power supply control, heating to electrolyte solution and substrate holder can adjust distance of electrode. Electrolyte solution was synthesized by platinum (IV) choloride (PtCl$_4$) powder (purity, 99.9 %) dissolved in hydrochloric...
Principle chiral models and their deformations are interesting systems with QCD-like behaviour. Furthermore, their integrable structure makes them potentially tractable. I discuss quantum mechanical theories arising in various limits of the models, with a view to analysing the non-perturbative dynamics.
The bamboo is highest growth rate plant in the world. Bamboo can grow 10 cm. in the days. Moreover it is environmental friendly and easy to regrow. Research studies founded spicy with high energy, drought resistance, can withstand flooding and suitable for growing in Thailand is ‘Dendrocalamus Asper Backer Bamboo’
The purposes of this study were found the best ratio of fuel briquettes from...
Today, dried shrimp in the market were refused food coloring and drying until shrimp are colorful and tasty. Meanwhile, Community groups, women's health trying to produce food products come from herbs. As an alternative to consumers. The production process is also a traditional way to dry. In order to extend the shelf life longer. Sometimes, potential risks, both in quality and quantity of...
Abstract
This research is studying dried banana. Using solar drying greenhouse. To compare the rate of drying Weight loss, Humidity and wet. Materials used in the experiments is Cultivated Banana. Banana Full ball and banana cut in half. The experiment compared to dry naturally with using 3-Shelves Solar Oven for a period of 3 days from the time. 09:00 to 16:00 hrs. Which records the...
Young star clusters harbor a large number of stars in pre-main-sequence (PMS) stage of their evolution. Physical properties of these stars can be constrained using various astrophysical techniques (e.g. by plotting them on HR diagram, studying their spectral energy distribution, times series photometric analysis, spectral studies, etc.). In this work we present preliminary time series...
Mismatch effect of renormalized Fermi velocity of massive Dirac fermions on the spin transport properties and tunneling magnetoresistance in a gapped graphene-based ferromagnetic/velocity barrier/ferromagnetic (FG/VB/FG) junction is investigated. The electrostatic potential created by the applied voltage on the VB region can generate spin-dependent collimation of Dirac fermions. The quantum...
Abstract
The quasinormal modes(qnm) of a massless charged scalar field in the 3+1 dimensional anti de Sitter(AdS) Reissener-Nordstrom(RN) spacetime are analytically calculated. The solutions of the scale field under the influence of the RN black hole are approximated by satisfying the boundary conditions at the horizon and the far away zone from the black hole. Our result for the small...
Radio astronomical observations have increasingly been threaten by the march of today telecommunication and wireless technology. Performance of radio telescopes lies within the fact that astronomical sources are extremely weak, e.g more than 15 orders of magnitude weaker than most mobile phones. The National Astronomy Research Institute of Thailand (NARIT) has initiated a 5-year project, known...
Abstract
Thailand was under the influence two types of monsoon winds, Northeast monsoon and Southwest monsoon. The Northeast monsoon (October – February) brings the cold and dry air from China to cover the major parts of Thailand. The Southwest monsoon (May – October) brings a stream of warm moist air from Indian Ocean towards Thailand causing abundant rain over the country. The objective...
Delamination is a mode of failure for composite different materials and can cause layer to separate between silicon die and die attach material. Because there is a mismatch in the thermal of materials, lead to cracking and damaging on integrated circuit (IC) packages. In this study, we attempted to reduce the delamination of mini small outline package (MSOP) in die attach process. The...
The purpose of this research aims to reduce of setup time in wafer sorting before integrated circuit packaging. To add hardware respectability detection process without prober setup before correlation wafer check process with modification of test program and making up a tool kid. Then, the experimental data was correlated with the respect range. Finally, this setting up was limited that it...
Biogas produced from the fermentation in the province of Maha Sarakham of excreta from cow dung, fattening pigs and buffalo dung in small scale farms contained hydrogen sulfide (H2S) at 764, 926 and 1,103 ppm, respectively. This gas has offensive smell and is corrosive to motor and metal stove of farmers, thus needs to be eliminated. The adsorbent granules soaking in FeCl3 and NaOH made from...
Riceberry is a highly nutritious rice variety with dark purple grain. Previous studies have shown that the darker shade of grain color has a higher nutrient content. In this work, we study the color distribution of the Riceberry rice grains in order to provide a quantitative quality indicator. Here, pictures of the grains were taken using a digital CCD camera. To make the data more...
The blue color of the blue sapphire is caused by the Fe-Ti pairs. Recently, the oxidation states of Fe and Ti on high-quality blue sapphire were found as Fe$^{3+}$ and Ti$^{4+}$. However, the oxidation state of Fe on natural sapphire with some inclusions was reported as mixing of Fe$^{2+}$ and Fe$^{3+}$ using the x-ray absorption near edge structure spectroscopy (XANES). Generally, there are...
We have focused on dark matter annihilation into electron-positron pairs, neglecting other processes, such as dark matter decay, or other annihilation products. Instead of focusing on a specific dark matter annihilation model, we have adopted a model-independent approach, in which all particles are created with the same initial energy, of the order of the mass of the dark matter particle. The...
The Schiff base was synthesized by 2,5-thiophenedicarboxaldehyde and 1,2,4-thiadiazole-3,5-diamine with condensation method. There was modified on Carbon paste electrode (CPE) and Printed circuit board (PCB) gold electrode for determination silver ion. The Schiff base film of modified electrodes was characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM),...
We investigate the behavior of Dirac Particle (electron and hole) confined on the surface of graphene wormhole, specifically, curvature induced by the geometry of graphene wormhole.
For calculation, we use numerical shooting method of finding eigenvalue of the Dirac equation in a curved space of graphene wormhole.
Our numerical results demonstrate that energy of band structures of the...
A system for measuring Seebeck coefficient has been designed and constructed which can be measures at room temperature. The system consists of three main parts, a temperature controlling, a data acquisition and a programming. The temperature controlling include of a PID temperature controller which fabricated by using an Arduino microcontroller boards. The data acquisition consists of two...
Electron beam irradiation can modify or improve chemical and physical properties of polymer and natural rubber. It is one of interesting and effective industrial applications of electron accelerators. This paper describes about the design of electron beam irradiation apparatus to find the efficient and convenient system for the natural rubber vulcanization. In addition, electron beam...
This research is a simulated and experimental study on effects of bipolar electrodes of a PEM fuel cell on its power conversion efficiency. The PEM fuel cell structure consists of bipolar electrodes, proton exchange membrane with catalysts, flow channels of gases. This research used fuel cell of 49 $cm^2$ in active area as a research sample and the Comsol 4.4 was employed to simulate flow...
In this study, the effect of urban structures (e.g. buildings, trees, bridges, etc.) on surface wind speed and wind direction was investigated using a Navier-Stokes equation solver to simulate wind over complex topography. The simulations were performed over the Lampang-Ngao highway and surrounding areas in Amphoe Muang Lampang in Thailand. This area is characterized by vehicular traffic...
Solar flare is the huge explosion on the Sun’s surface and releases the solar energetic particles (SEPs) to interplanetary medium.The objective of this work is studying the propagation of SEPs from the Sun to the Earth. We simulate the particle propagation for the solar event on August 9, 2011 with the transport equation of Ruffolo 1998. We solve the transport equation by the numerical...
Gemstone commercial is a high revenue for Thailand especially ruby and sapphire. Moreover, Phrae is a potential gem field located at the northern part of Thailand. The studies of spectroscopic properties are mainly to identify gemstone using advanced techniques (e.g. UV-Vis-NIR spectroscopy, FTIR spectroscopy and Raman spectroscopy). Typically, UV-Vis-NIR spectroscopy is a technique to study...
We use the Moiré fringe patterns to measure the stress and strain values of rubber in tension, and analyze the stress-strain relationship. With the printed straight-line pattern on a standard dog-bone specimen, the Moiré patterns can be constructed when the rubber specimen is stretched. The geometrical relationship of bright and dark fringes is used to calculate the strain values both in the...
The structural and optical properties of the mercury chalcogenide HgSxSe1-x and HgSxTe1-x nanocrystals with zinc-blende structure are analyzed using the sp3s* empirical tight-binding method. We calculate the single-particle spectra, band gaps, charge densities, density of state (DOS), electron-hole interaction and optical properties as a function of diameters and alloying concentrations (x)....
The Metal Organic Vapor Phase Epitaxy is single crystal growth process, forming GaAsN films on GaAs (001) substrates, built up by chemical method using trimethylgallium (TMGa), dimethylhydrazine (DMHy) and tertiarybutylarsine (TBAs) as Ga, N and As, respectively. Commonly, the process is contained hydrogen (H$_2$) gas, a carrier gas, to convey precursor to the reaction chamber. Alternatively,...
YH$_{2.83}$ and ScH$_{2.83}$ are a defected system in which some interstitial sites of hydrogen atoms are void. We used \textit{ab-initio} method to study their structural stability and electronic structures. The hcp phase of YH$_3$ and ScH$_3$ is used as an initial structures, which composes of 6 metal atoms and 18 H atoms per unit cell. Then, YH$_{2.83}$ and ScH$_{2.83}$ are obtained by...
The magnesium oxide (MgO) nanoparticles were synthesized by microwave-assisted thermal oxidation. The crystal structural, morphology, optical property were characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), UV-Vis Spectrophotometry, Photoluminescence (PL) spectra, respectively. It was observed that, the synthesized...
Cobalt ferrite nanoparticle (NP) is a class of ferrite which has a potential for many applications but the agglomeration of magnetic NPs limits its full potential usage. In this research, cobalt ferrite NPs were synthesized in the presence of bacterial cellulose (BC) nanofibers which acted as the scaffolding templates. The BC was obtained from a commercially available nata de coo (coconut...
Micrometre-scale graphene sensors can detect individual molecule adsorptions or desorptions [1]. This is due to its low-noise electronic characteristics. However, molecules in gas phase rarely adsorb on non-defect graphene surfaces. By doping graphene with nitrogen, the atomic structure and electronic properties of graphene were modified. Here, we measured the sensitivity of graphene and...
We study a subclass of GLPV modified gravity theories generated by a general disformal metric $\bar g_{\mu\nu} = g_{\mu\nu} + D(\phi,\partial \phi) \partial_\mu\phi \partial_\nu \phi$. By solving the background evolution equation, we found that such theory cannot provide the self-accelerating solution.
This research studied about an epoxy molding compound (EMC) floor life to reliability performance of integrated circuit (IC) package. Molding is the process for protecting the die of IC package form mechanical and chemical reaction from external environment by shaping EMC. From normal manufacturing process, the EMC is stored in the frozen at 5 C and left at around room temperature for aging...
We have reported physical and electric properties of Mg1-xMnxFe2O4 (MMF) (x = 0.5 - 0.7) ceramics were prepared using co–precipitation method. The effects of Mn content on the phase formation, morphology, density and electrical properties were investigated. The XRD analysis of the as synthesized powder confirms the formation of the single phase MgMnFe2O4 spinel structure. The microstructure...
Cosmic-ray muons are produced in the atmosphere as results of the collision of incoming high-energy particles, i.e. cosmic rays, from outer space with atmospheric particles. In this work, a simple detector has been built to measure the speed of cosmic-ray muons. The detector is composed of two scintillation bars of a rectangular cross-sectional area of 4×6 cm$^2$ and a length of 127.5 cm, with...
The kaon production in heavy ion collisions at intermediate energies provides a sensitive probe to study the in-medium properties and nuclear equation of state. Kaon properties in dense hadronic matter are important for understanding of nuclear matter at high densities. We investigated the in-medium kaon potential by rapidity density distribution and transverse mass spectra for ${K^ +...
RX Hydrae is a bright Algol-type eclipsing binary system with orbital period is 2.2825 days. This system was classified as the member group of oEA stars in 2002. The short-periodic pulsations of a primary component were detected by Kim et.at (2002) who classified the system as a new member of oEA group of pulsators. The new CCD photometric and spectroscopic observations of RXHya were obtained...
In this research we investigate the relationships between wind speed and temperature time series data in Bangkok, Thailand, from the time interval of January 2009 to December 2011 using wavelet transform (WT), cross wavelet transform (XWT) and wavelet coherence (WTC). The results from all three wavelet analysis show the strong periodicity around period 1 day (hourly data) and period band...
Now the Sun is in the 24$^{th}$ solar cycle. The peak of solar cycle corresponding to the number of the Sun activities, which one of them is solar flare. The solar flare is the violent explosion on the surface of the Sun and releases the high energy ion from the Sun to the interplanetary medium. Solar energetic particles or solar cosmic ray have important effect on the Earth, such as...
Nowadays, the studies of exoplanets are extensive and various. The different techniques are used to analyze the masses, radii and other specific data about exoplanets. HAT-P-47b transiting exoplanet candidate is a recent discovered low density sub-Saturn mass exoplanet. The planet is one of the lowest mass planets with the radius larger than Jupiter radius, which is a suitable candidate for...
Abstracts
The purpose was study about the properties of the insulation fibers panels from waste of tea leaves and water hyacinth. it mixed together in 5 ratio 100:0 , 80:20 , 50:50 , 20:80 , 0:100 with compress insulation by machine by 120 kg/square centimeter in 10 minutes product is flat size 400x 400 mm. and thickness is 10 mm. will produce insulation at a density of two...
The hybrid quantum mechanical/molecular mechanical (QM/MM) method has been used to investigate on mono-hydration and poly-hydration phenomena of the polar head group of Span 60 molecule in both gas and aqueous phases. Our calculations were performed by using Gaussian 09 program. The result indicates that Span 60 interacting with one water molecule shows the mono-hydration effect of the head...
Polypyrrole (PPy) have been considered as one of the most promising conducting polymers for gas sensor application due to it can operate efficiently at room temperature, light weight, thermal stability and high sensibility. In this research, we have been reported the geometric and electronic structure of PPy based on B3LYP/3-21G$^*$, B3LYP/6-31G$^*$ and SCC-DFTB methods. The effects of polymer...
In this research, a nondestructive, simple and rapid method, photothermal deflection technique or the so-called “mirage effect”, is setup. A flat and smooth sample is heated by a modulated 532nm 14mW pump beam on the surface. The heat flow induced by the surface layer is detected by the deflected 632nm 0.14mW probe beam. The frequency-dependent signal in the range of 1 - 800 Hz is measured by...
This research is to study thermal efficiency of natural convection. Working principle of natural convection solar dryer is, once air in solar dryer is heated by solar energy, the air relative humidity will drop and floating up through the drying. This air will take moisture out of the product and flow out to ambient air. It was found from the experiment that, in the duration of 8.00 am – 4.00...
The objective of this research was to produce green fuel briquettes from corncobs by adding macadamia shell charcoal powder. The study was sectioned into 3 parts: 1) Quality improvement of green fuel briquettes by adding macadamia; 2) Fuel property analysis based on ASTM standards and efficiency on heat capacity; and 3) Economics appropriateness in producing green fuel briquettes. This...
Abstract
In microelectronic industry, the lubricants are used in the wafer-to-chip grinding and lapping processes before device assembly step. The based lubricant and additives play important roles in the product quality and reliability for those nano-scale fabrications. In this study, the tribological behaviors of AlTiC surface that sliding against AISI304 balls were studied in...
This research studied about warpage of QFN package in post mold cure process of integrated circuit (IC) packages using pre-plated (PPF) leadframe. For IC package, epoxy molding compound (EMC) are molded by cross linking of compound stiffness but incomplete crosslinked network and leading the fully cured thermoset by post mold cure (PMC) process. The cure temperature of PMC can change...
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Ultraluminous X-ray sources (ULXs) are non-nuclear, extra-galactic X-ray point sources with X-ray luminosity ($L_{\rm X}$) in excess of the Eddington limit for a 10 M$_{\odot}$ black hole ($L_{\rm X}$ $>$ $10^{39}$ erg s$^{-1}$). It is thought that the majority of ULXs are accreting black holes. However, due to their extreme brightness, the mass of black holes...
