Conveners
Poster Session - NAT
- Juan Estevez (CEADEN, Cbua)
- Oscar Diaz-Rizo (InSTEC, Cuba)
- Piet Van Espen (University of Antwerp)
Poster Session - NAT
- Juan Estevez (CEADEN, Cuba)
- Oscar Diaz-Rizo (InSTEC, Cuba)
- Piet Van Espen (University of Antwerp)
The age of sediment layers in regions near to the coast in Pinar del Rio province are determined using the quartz photoluminescence method. In some locations the studied layer could be associated with altimetry measurements allowing future analysis of recent tectonic movements. The method for sample collection, preparation and measurement are described. The results analysis indicates...
The natural dose rate is one of the physical magnitudes calculated during the process of age determination of geological sediments with the luminescence technique. The dose rate is calculated on the basis of the radioactive content presented in the sediments. Because of the low content of these radioactive isotopes a low background system should be used. In the present work the low background...
The gamma spectrometry is the most popular technique for the determination and quantification of the radioactive nuclei present in a radioactive source. In order to obtain the quantification of the radioactive material it is necessary to determine the efficiency of the detector for the energies of the gamma photons emitted from the source.
In the present work we present the theoretical...
In previous researches, it has been identified the presence of tetragonal and rhombohedral crystalline phases in ferroelectric ceramic samples of PbZr$_{0.53}$Ti$_{0.47}$O$_3$ doped with La (1%) (PLZT) irradiated with $^{60}$Co gamma rays, showing their corresponding XRD patterns not conclusive evidences of phase transformations between both phases assisted by gamma irradiation.
The present...
On the basis of the atomic displacement energy ($T_d$) calculated using the Density Functional Theory with Tight Binding Approximation (DFTB), the cross sections of electron-induced atomic displacement were obtained as a function of the order of the fullerene. Three types of defects commonly induced by radiation (mono-vacancy, di-vacancy and Stone-Wales) were also analyzed, determining their...
The ionizing radiation absorbed by semiconductor devices can change their properties by modifying the electrical parameters that characterize them and, in the case of memories, processors, can modify the information contained in these devices. In this way, the development of electronic devices resistant to radiation and the qualification of devices confirming that they are more tolerant to the...
For luminescence dating to be an accurate absolute dating technique it is very important that we are able to deliver absolutely known radiation doses in the laboratory. This is normally done using a beta source calibrated against an absolutely known reference source or by using a reference luminescence material that has been irradiated in a radiation calibration facility. Here we describe in...
For decades, the great economic benefit that represents the use of radiotracers has been recognized by the international industry, however, this technique is still underutilized. The main cause is the lack of timely availability of required radiotracer. Previous studies show the possibility of labeling sediments (with a high content of aluminosilicates) with $^{99m}$Tc. This paper aims to...
Semiconductor devices are susceptible to ionization radiation and this kind of event can change their behaviour and electrical properties, causing since a simple current peak on output of the circuit to a logical inversion, each event have your own root cause that can variable from an absorbed radiation dose to a different source of radiation. To deal with these problems is necessary...
The simulation of the spectroscopy systems using MC codes is a common practice in these days. The most popular softwares to do this are MCNP and Geant4 codes. In this work we present the simulation of a gamma spectroscopy system based on a coaxial HPGe detector using FLUKA code. The geometrical characterization of the detector was done from manufacturer information and using the spatial FEP...
Every day, the population is exposed to various types of radiation sources. In particular, the radon is the most common radiation present in a gas form. Radon belongs to the radioactive series of uranium and in its decay emits alpha particles of 5.49 MeV. To detect these alpha particles, an effective method very commun is to use Solid State Nuclear Track Detectors (SSNTD). This work propose a...
2-hydroxyethyl methacrylate/Acrylamide hydrogels were prepared by simultaneous radiation induced cross-linking copolymerization of acrylamide (AAm), 2-hydroxyethyl methacrylate (HEMA) and water mixtures at a radiation dose of 10 kGy. Hydrogesl were characterized by infrared spectroscopy. Dynamic and equilibrium swelling of hydrogels in water and in buffer solutions were investigated. They were...
Biomaterials have received a considerable attention over the last 30 years as a means of treating diseases and easing suffering. These materials have found applications in approximately 8000 different kinds of medical devices; even though biomaterials have had a pronounced impact in medical treatment, a need still exists to be able to design and develop better polymer, ceramic, and metal...
The intrinsic spatial efficiency method is a general and absolute method to determine the efficiency of any extended source. This was experimentally demonstrated and validated only for cylindrical sources and the gamma photons emitted by $^{137}$Cs (661,65 keV).
Also, we carried out a research to tested the method for different shapes and sizes. Due to the difficulty that the preparation of...
Electric Field Gradients (EFG) at Zn and O sites in disordered $^{57}$Fe doped ZnO matrixes arising from $^{57}$Mn irradiated ZnO samples with wurtzite crystal structure were simulated through DFT atomistic calculations methods. The ZnO disordered crystal defective structures were simulated by means of overdimensioned unit cells (supercell) containing Zn vacancies at different concentrations...
The objective of the experiment is to measure NORM (Naturally Occurring Radioactive Material) in natural samples and calculate their concentrations. For this purpose, experiments detecting the radiation of several gamma-ray calibration sources located at different positions around an HPGe detector were conducted. The efficiency calibration curve for each position was obtained, a piece of...
In OSL dating of sediments the application of the single aliquot regenerative (SAR) protocol requires the calibration of each aliquot by giving them a known dose using an internal beta source with a dose rate ranging from 100 to 30 mGy/s. In the case of old samples that have received in natural conditions doses higher than 70 Gy the time employed to equate this dose may be significant. One...
Air quality models are an important tool to assess the responsibility for existing air pollution levels through the evaluation of source-receptor relationships. Back trajectories have frequently been used to identify potential source areas of air pollutants and to clarify their respective contribution at receptor sites.
CALMET/CALPUFF modelling system is well known, and several validation...
Slags are final by-products involved in the iron and steelmaking process. The general tendency in the foundry workshops in Cuba is to consider slag as a waste material and deposit it in the yards of the workshops or in municipal landfills affecting the environment. Its composition and characteristics depend and vary widely according to the raw material used, the technology employed and the...
The objective of this work was to evaluate the exposure levels to PM10 to which workers are exposed during the working day. Sampling was carried out in two workplace areas of a factory located in Santa Clara city: the iron casting workshop and the unmolding workshop. The factory utilizes as raw materials: iron scrap, ferroalloys, coke, and materials from the own process as pig iron and return...
One of the nuclear techniques that are being investigated by different groups in the field of explosives detection and demining is the thermal Neutron Backscattering Technique (NBT). NBT is based on the fact that the buried target is Hydrogen-rich and therefore if it is in a media with different Hydrogen content and it is exposed to a fast neutron source, the number of backscattered thermal...
Tri-structural Isotropic (TRISO) based fuel with SiC matrix can be used in Light Water Reactors (LWRs) for enhancing its safety features in extreme situations. Besides the simplification of the design, the utilization of TRISO fuel particles in PWR technology enhances its integrity by confining the radioactive fission products within fuel itself during the reactor operation. In this work, the...
Building on the success of the large nuclear plants, SMRs offer the potential to expand the use of clean, reliable nuclear energy to a broad range of customers and energy applications. In this work, a model to describe the neutronics parameters of a SMR core that can produce up to 530 MW of thermal power was developed. Using this model, several configurations of fuel enrichment to obtain the...
In this work, several oil samples from different Brazilian basins were investigated using Energy Dispersive X-Ray Fluorescence spectroscopy technique (ED-XRF) aiming to obtain qualitative information about their chemical composition [1,2]. The budget of analyzed samples was composed of twelve oil samples from five distinct oil fields belonging to the Campos Basin of the Esp ́ırito Santo and to...
The present work presents a procedure designed for the improvement of the Quality Management System (QMS) implemented in the laboratories of Chemical Analysis and Materials of the CEADEN according to NC ISO / IEC 17025: 2006 in order to allow a stability in time of their status as accredited laboratories. In these laboratories, nuclear and complementary techniques are used in research and...
Radioactivity levels in peloids from some Cuban spas (San Diego, Elguea, Santa Lucía and Cajío) have been studied. The radionuclide concentration (in Bq.kg-1 dry weight) varied as follows: $^{226}$Ra = 6 – 1800, $^{137}$Cs = <2 – 5, $^{232}$Th = 6 – 38 and $^{40}$K = 47 – 365, being comparable to concentrations reported for therapeutic peloids used worldwide. Considering the short exposition...
The regional offset correction ΔR of Marine Reservoir Effect (MRE), crucial for correcting $^{14}$C ages calibration for marine influenced samples, was determined for Cuban Northwest coast. Fifteen different locations were studied by $^{14}$C dating of pre-bomb known-age marine shells specimens of bivalves and gastropods from the Felipe Poey Museum collection. The distribution of results...
The application of the method of radioactive indicators in research and development of drugs is of great importance for the pharmaceutical industry. Many non-clinical and clinical trials rely on the radiolabelling of the molecules being tested as potential drugs. In the present investigation, a preliminary computational model was developed to obtain the possible structures of the CIGB-300...
Concentrations of various chemical elements in street dusts from Camagüey city were studied by X-ray fluorescence analysis. The mean Cr, Co, Ni, Cu, Zn and Pb contents (in mg.kg$^{-1}$ dry weight) in the urban dust samples were compared with mean concentrations in other cities around the world. Spatial distribution maps indicated the same behaviour for Cr–Ni and Pb–Zn–Cu, whereas the spatial...
As part of the instrumentation development program of the luminescence dating laboratory at CEADEN a package of open-source software supporting the luminescence measuring process is carried out. The package released under the name of Sequence-Toolkit is routinely used to create and analyze the results of the measuring sequences introduced to the automated luminescence reader LF02. Here we...
Rhenium bis-arenes can be obtained by heating the corresponding potassium perrhenate (KReO$_4$) salt with an arene as a solvent and in the presence of aluminum chloride (AlCl$_3$) and zinc. Variations of this method, originally proposed by Fischer and Hafner, demonstrated that, in some cases, the reaction occurs without using Zn as a reductive agent, but also, that the presence of the Lewis...
The losartan and its fluoro n-ethoxy-methyl-triazole losartan derivatives (FEM, n=0-3) were studied as potential candidates of $^{18}$F-labeled radiopharmaceuticals. Each derivate is obtained by the reaction of a terminal alkyne with a substituted azide in presence of Cu(I) catalyst. The stability and association energy of four FEM to the AT1 receptor was evaluated. The Density Functional...
The objective of the present study was to evaluate the distribution and accumulation of some heavy metals in surface sediments from the Mamposton reservoir (Mayabeque province, Cuba) and its main tributaries (Ganuza and Mamposton rivers and Pedroso dam). Furthermore, it was of great interest to assess their potential risk with regard to human health. Concentrations of Fe, Ni, Cu, Zn and Pb...
