Measurement of photon interaction parameters of high-performance polymers and their composites

WOS: 000438143300012In the present study, commercially important high-performance polymers and their composites have been investigated with respect to photon interactions as means of mass attenuation coefficient (/), mean free path (MFP), half-value layer (HVL), effective atomic number (Z(eff)), effective electron density (N-eff), and energy absorption and exposure buildup factors (EABF and EBF) at different photon energies. For this purpose, sample plates were prepared by extrusion and injection techniques using polyethersulfone, polyetherimide, acrylonitrile butadiene styrene copolymer, polyamide 66, polyphthalamide, and polypropylene copolymers as high-performance polymers and glass and carbon fibers as reinforcement. The (/) s of the materials were measured at 81 and 356keV photon energies to determine MFP, HVL, Z(eff), and N-eff. The theoretical values of these parameters were calculated via ZXCOM, WinXCom and Monte Carlo N-Particle simulation code (MCNP), and a good agreement was obtained between WinXCom-MCNP and MCNP-Exp. Finally, EABFs and EBFs of the samples were calculated up to around 40 MFP in the energy region 0.015-15MeV and significant variations were observed in the continuous energy and MFP regions

The assessment of usage of epoxy based micro and nano-structured composites enriched with Bi2O3 and WO3 particles for radiation shielding

This study has been devoted to investigate the radiation shielding performance of epoxy-based micro and nano Bi2O3 and WO3 reinforced composites. While the research has been carried out by using experimental data and MCNP6 simulation for the micro-structured composites; the effect of nano Bi2O3 and WO3 particles addition on the radiation shielding property of epoxy has been discussed by using experimental data. While the gamma-ray spectroscopy experiments have been carried by using NaI(Tl) scintillation detector and Ba-133, Cs-137, and Co-60 sources, the MCNP version 6.2 code has been utilized for the simulation. The experimental and MCNP6 simulation results showed good consistency for both particle reinforcement and different incoming photon energies. Particle size effect investigation also indicated that for both kinds of dopant particles, the nano dopant is more successful in attenuating the intensity of incoming photons than the micro dopant even if they are used in the same percentages. In conclusion, it can be suggested that the micro and nano-structured composites having the highest Bi2O3 and WO3 contents have a considerable potential to shield the harmful effects of some of the diagnostic radionuclides utilized in nuclear medicine as well as the radiation imaging machines such as roentgen, mammography or PET scans

Computation of EABF and EBF for basalt rock samples

In this study, certain photon absorption parameters including the energy absorption buildup factor (EABF) and exposure buildup factor (EBF) have been investigated for three different basalt samples collected from different parts of Van city. Radiation shielding properties of the basalt samples indicated a strong correlation between photon energy absorption parameters and values of EABF and EBF of basalt samples. It was found that EABF and EBF parameters are related to radiation shielding properties of basalt samples. A new method and algorithm based on ZXCOM was used. Instead of calculating G-P fitting parameters for every effective atomic number (Z(eff)), EABF and EBF were calculated for Z(eff) by interpolation, using ANSI/ANS 6.4.3 standard data available for Z(eff). (C) 2015 Elsevier B.V. All rights reserved

Availability of water glass/Bi2O3 composites in dielectric and gamma-ray screening applications

Sodium silicate (Na2Si3O7) also known as water glass is a very low cost material which is used in many industrial applications such as a builder in detergents, as a binder and adhesive etc. But so far the electrical properties of sodium silicate and its ability to screen radiation have never been investigated. In the present study, the frequency dependent electrical properties and gamma-ray shielding performance of water glass based bismuth oxide composites have been studied for the first time. In accordance with this purpose, Na2Si3O7/Bi2O3 glassy composites have been prepared for searching their possible applications in electronics and radiation screening. The surface morphology of the samples have been determined by Scanning Electron Microscope (SEM). The frequency dependent electrical properties such as complex impedance, complex dielectric function and conductivity have been analyzed at room temperature between 1 and 40 MHz. As a result of alternative current (ac) electrical analysis, it has been determined that the Na2Si3O7/Bi2O3 composites can be utilized as a dielectric layer in capacitors. On the other hand, since bismuth oxide is an anti-radiative material, the gamma-ray screening parameters such as mass attenuation coefficient, half layer and tenth layer values along with mean free path of the composites have been defined experimentally by using NaI(Tl) scintillation detector for the Ba-133 radiation source at 81 and 356 keV. The values of these parameters have also been checked by Monte–Carlo simulation. Since a good agreement has been assigned between experimental and Monte–Carlo simulation results, the related gamma ray shielding parameters have been determined by Monte–Carlo simulation for other gamma photon energies (140 keV, 208 keV, 468 keV, and 661 keV) which are generated from Tc-99, Lu-177, Ir-132, and Cs-137 sources. Ultimately, Na2Si3O7/Bi2O3(35%) composite has been suggested as an eco-friendly, lead-free glassy structured material for the gamma radiation shielding in medical applications.2015-01-01-KAP0

PT/BORAX COMPOSITE AS A HIGH DIELECTRIC CONSTANT MATERIAL WITH LOWER DIELECTRIC LOSS

In recent years, high dielectric constant composites have been considered as the key materials for many cutting-edge applications such as supercapacitors, memory devices, electrical, mechanical, and biochemical engineering. However, the high dielectric loss at low frequencies become a crucial problem which makes the composite unsuitable for these technological applications. In this respect, this work has been devoted to prepare a new high dielectric constant composite material with low dielectric loss. From this point of view, Polythiophene /Na₂B₄O₇ (PT/Borax) composites with different borax contents varying from 10.0 wt.% to 50.0 wt.% have been prepared. The morphology and chemical structure of the composites as well as pure PT have been determined by Scanning Electron Microscopy (SEM) and Fourier Transformed Infrared (FTIR) Spectroscopy, respectively. The dielectric properties of the samples have been measured within 100Hz-16.5MHz frequency region at room temperature. The polymer composite with high dielectric constant and low dielectric loss at low frequency for various technological applications has been achieved for 50.0 wt.% Borax additive. The dielectric relaxation mechanism of the samples have also been identified as non-Debye type. The electrical conductivity properties of the samples have also been discussed in terms of Jonscher’s Universal power law

BXCOM: A software for computation of radiation sensing

WOS: 000469740700001The main objective of this work is to develop user-friendly software, called BXCOM, for computation of the exposure build-up factor (EBF) and the energy absorption build-up factor (EABF), using geometric progression (G-P) fitting method for element, compound or mixture in the energy region 0.015-15 MeV, and for penetration depths up to 40 mean free path (mfp). Furthermore, BXCOM can generate the equivalent atomic number and five fitting parameters used in the G-P method for mixtures and compounds over an interval of photon energies extended from 0.015 to 15 MeV. In addition, the program is designed to calculate the effective atomic number and effective electron number via the direct method. BXCOM program has been verified by comparing its results with approved data by American National Standards Institute. BXCOM runs under MS Windows (R) operating system. It has an improved user interface that provides examination of material's radiation interaction parameters. Finally, BXCOM allows rapid and reliable calculation of many gamma-ray interaction parameters such as , , , G-P fitting parameters and build-up factors that are essential in a wide range of applications such as radiation shielding, radiotherapy, technology and so on.Turkiye Bilimsel ve Teknolojik Arastirma Kurumu [2015-115F311]This work was supported by Turkiye Bilimsel ve Teknolojik Arastirma Kurumu [Grant Number 2015-115F311]

Dielectric and gamma shielding properties of sodium silicate glassy structure modified with tungsten

WOS: 000465570500006In this study, (x)%Na2Si3O7/(100 - x)%W glassy structured composites where x = 100, 25 and 60 were prepared for the investigation of their dielectric and gamma-ray shielding properties for the first time. The surface morphology of the samples was imaged by Scanning Electron Microscope. The room temperature complex impedance and dielectric function analysis of the samples revealed that the Na2Si3O7/40%W composite has a promising potential for the decoupling capacitor and electromagnetic shielding applications. From this point of view, the gamma-ray shielding performance of the samples including pure Na2Si3O7 was tested by Ba-133 radioactive point source for transmission of the gamma rays at 81 and 356 keV photon energies. The mass attenuation coefficients (mu/rho) of the composites were measured at these energies by using NaI(Tl) scintillation detector. The experimental half-value layer (HVL), tenth-value layer (TVL) and mean free path (lambda) were also calculated. The theoretical values of the (mu/rho), HVL, TVL and lambda were determined by using Monte Carlo N-Particle simulation code and WinXCom for the comparison. A good agreement between the experimental and theoretical results for the gamma-ray shielding parameters was obtained. While the mass attenuation coefficient increased considerably with an increasing tungsten concentration doping, it decreased with increasing gamma-ray energy. It was observed that the mass attenuation coefficient of Na2Si3O7/40%W composite is higher than that of lead at 81 keV. In addition, HVL, TVL and lambda parameters were found to decrease with increasing W doping. Since there is a good agreement between MNCP results and experimental data, the gamma radiation shielding performance of the samples for some low and high energetic gamma-ray sources such as Am-241, I-131, Cs-137 and Co-60. Ultimately, Na2Si3O7/40%W composite can be suggested as a new alternative non-toxic radiation shielding material for low energetic gamma rays.Yildiz Technical University Scientific Research Projects Coordination Department [2015-01-01-, KAP06]This work was supported by Yildiz Technical University Scientific Research Projects Coordination Department under Project number: 2015-01-01-.KAP06. Y. Karabul, one of the authors of the paper, was also supported by a 2228 Tubitak scholarship program

Na2Si3O7/Ag micro and nano-structured glassy composites: The experimental and MCNP simulation surveys of their radiation shielding performances

In the present work, the very low-cost glassy structured sodium silicate (Na2Si3O7) matrix has been reinforced with micro-and nano-sized silver (Ag) particles in different weight percentages. The ionizing radiation shielding performances of the micro and nano-structured composites have been determined experimentally and theoretically for the first time. The experiments have been realized by the gamma-ray spectroscopy setup equipped with NaI(Tl) detector and Ba-133 point radioactive source. The radiation shielding performance has been discussed in the context of mass attenuation coefficient (μ/ρ) half-value layer (HVL), and mean free path (MFP). Besides, the theoretical research related to the radiation shielding ability of the samples has been carried out by using the Monte Carlo N-Particle Transport (MCNP) v6.2© simulation code. Since the experimental values and MCNP findings are very close to each other, MCNP simulation has been extended to a large incoming photon energy interval ranging from 25 keV to 1000 keV for both micro-and nano-structured composites. The particle size effect (PSE) on radiation shielding performance has been investigated and discussed. As a result of PSE research, it has been revealed that the addition of nanoparticles is more effective in the improvement of the radiation shielding for the lowest Ag concentration and low photon energies. Additionally, the radiation shielding capability of the composites has been discussed in the context of ambient dose equivalent, H∗(10) which is one of the operational quantities. By using the ambient dose equivalent definition, the ambient dose rate values of the composites have been calculated for the first time. In conclusion, it has been determined the composites with higher micro-and nano-Ag particle additives have considerably good radiation shielding ability against low energy photons that are mostly utilized in diagnostic and treatment medical applications

Determination of Se, Cr, Mn, Zn, Co, Na, and K in blood samples of breast cancer patients to investigate their variation using ICP-MS and ICP-OES

The aim of this study was to investigate the concentration changes of Se, Mn, Cr, Zn, Co, Na and K in blood samples of breast cancer patients. Determination of the elements was performed using ICP-MS and ICP-OES instruments. Kolmogorov- Smirnov normality tests, Mann-Whitney U tests, Independent sample T tests and Spearman’s rank correlation tests were performed for statistical comparisons. It was found that the concentrations of Na and K in breast cancer patients were higher than for healthy people. The Se, Mn, and Cr concentrations were found to be lower in patients with breat cancer. No increase/decrease in Zn concentrations between the two groups was observed. A positive correlation was found between the distribution of Zn and K elements. Independent sample t and Mann- Whitney U tests demonstrated that statistical differences were observed between patients having the diagnosis of breast cancer and healthy people in terms of the concentrations of Se, Cr and Na. The results presented in this study will contribute to the literature by showing the relationship between breast cancer and element concentrations.2210C 2015-01-01-YL04, 832Yildiz Technical Universit

X-ray irradiated LDPE/PP blends with high mechanical and dielectric performance

WOS: 000432005700019In this study, the influences of polypropylene (PP) additive (varying from 20% to 80% wt) and low dose X-ray irradiation (changing from 25 to 100 Gy) on the mechanical and dielectric properties of low-density polyethylene (LDPE) were investigated. LDPE/PP film blends were prepared by hot press technique. While the highest Young modulus and tensile strength were observed for the 20%LDPE/80%PP blend at 25 Gy X-ray irradiation, the same blend had the highest energy at break and percentage strain at break values for 50 Gy X-ray exposure. These results also indicated a chain scission in the material. The differential scanning calorimetry curves also indicated a chain scission and crosslinking effects in the blends due to X-ray irradiation. Hence, the higher concentration of PP additive and exposure of low dose X-ray resulted in a polymer composite with high mechanical performance. On the other hand, the dielectric investigations revealed that the 25 Gy X-ray irradiated 20%LDPE/80%PP blend may also attract attention for capacitor applications due to its increased static dielectric constant and reduced dielectric loss.Yildiz Technical University Scientific Research Projects Coordination Department [2015-01-01-GEP03]This work has been supported by Yildiz Technical University Scientific Research Projects Coordination Department under Project number: 2015-01-01-GEP03