Süleymaniye Kütüphanesi

Taha Toros Arşivi, Dosya No: 111-Kütüphanelerİstanbul Kalkınma Ajansı (TR10/14/YEN/0033) İstanbul Development Agency (TR10/14/YEN/0033

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

An experimental study on the linear differential scattering coefficients of the Trommel Sieve Waste (TSW)

The linear differential scattering coefficients (LDSCs) at 60 keV are measured for TSW at seven angles ranging from 60 degrees to 120 degrees at intervals of 10 degrees. The results are compared with relativistic and non-relativistic theoretical values. The purpose of this work is to seek evidence whether there is a relationship between the LDSC and the scattering angle. This is the first time the LDSCs have been measured at energies lower than 100 keV, so there is a lack of comparable findings reported in the literature. (C) 2009 Elsevier Ltd. All rights reserved

Radiation interaction parameters for blood samples of breast cancer patients: an MCNP study

The main goal of this study was to determine radiation interaction parameters such as mass attenuation coefficients, effective atomic numbers, and effective electron densities depending on element concentrations (Na, K, Cu, Zn, Al, Ca, Mg Cr, Fe, Se) in blood samples of patients with breast cancer. Eighty blood samples were collected and analyzed in this study (40 from breast cancer patients and 40 from healthy patients). The determination of element concentrations of the samples was performed with inductively coupled plasma-mass spectrometry (ICP-MS) and inductively coupled plasma-optical emission spectrometry (ICP-OES) after which the element concentrations were normalized to percentage. Mass attenuation coefficients were calculated by Monte Carlo simulation method. In addition, effective atomic numbers and effective electron density values of the blood samples were calculated with the ZXCOM program. One of the most important results of this study is that differences in radiation interaction parameters between the two groups were observed. More specifically, the mass attenuation coefficients of the healthy group's blood samples were higher than those of the cancerous group at photon energies of 50 keV, 100 keV, 250 keV and 500 keV, while they were lower at 1 MeV. All the MCNP results were consistent with the results obtained from ZXCOM. As the main result of this study it is concluded that photon atomic parameters such as mass attenuation coefficient, effective atomic number and electron density may be considered in cancer diagnosis or treatment modalities.Türkiye Bilimsel ve Teknolojik Araştırma KurumuBAP Yildiz Technical Universit

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]

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