Papers by Keyword: Dose Rate

Abstract: Radon concentrations in fertilizer samples collected from agricultural areas in Cameron Highlands and Penang, Peninsular Malaysia were studied throughout this paper. The concentrations were measured using a sealed-can technique based on the CR-39 SSNTDs. Results indicate that the concentration of radon in the phosphorus sample was the highest whereas the minimum values were found in CDM (Cow dung manure). The levels of radon concentration were found to lie within the range of (634.0151.42 to 79.2523.24) Bq m^-3.

Abstract: Abstract. The dose calculation parameters of ¹⁰³Pd radioactive seed need to be determined strictly before clinical application for tumor implanted treatment. The radial dose function and the anisotropy factor are data analyzed and nonlinear fitted based on the value of dose parameters in American Association of Physicists in Medicine (AAPM) TG-43 and TG-43U1 by Cftool and SFTool toolbox in Matlab. Result was selected according to the optimum principle of fitting accuracy that is the coefficient of determination is close to 1 and gets the minimum value of the sum of square of deviations in fitting process. The calculation of the radial dose function and the anisotropy factor result are obtained in an ideal situation, and then the dose calculation of ¹⁰³Pd radioactive seed is determined. The calculation of ¹⁰³Pd radioactive seed provides a theoretical basis for ¹⁰³Pd implanted treatment of tumor in clinical.

Abstract: In this study, electron beam irradiated (EB) was applied as a crosslinker agent for both pristine high density polyethylene (HDPE) and HDPE/ ethylene propylene diene monomer (EPDM) nanocomposite systems. The doses rate for EB irradiated technique were varied between 50, 100, 150 and 200 kGy. The nanocomposites systems were first prepared via melt intercalation method with different organophilic montmorillonite (OMMT) loadings. It was found that, with 4 vol% organophilic montmorillonite (OMMT) loading, the barrier resistance of nanocomposite against oxygen transmission was significantly enhanced by EB irradiation dose rate of 100 kGy. The oxygen transmission for nanocomposite was reduced by 23.48%. The interplanar spacing, d-spacings of OMMT in nanocomposites were monitored using x-ray diffraction (XRD) and the extent of delamination was examined by transmission electron microscope (TEM). The wide angle of XRD patterns showed the increased interplanar spacing, d of clay layers, indicating enhanced compatibility between polymer matrix and OMMT with EB irradiation. TEM photomicrographs illustrated the mixed intercalated and partial exfoliated structures of the nanocomposites with the irradiation process.

Abstract: Mechanisms of degradation of physical-mechanical properties of PVI steels during irradiation are studied. Microstructure evidence of influence of irradiation temperature, dose and dose rate on processes of low-temperature swelling and embritllement of pressure vessel internal materials, 18Cr-10Ni-Ti steel, of reactor WWER 1000 are presented. Micro mechanisms of plastic deformation and steel failure in wide range of temperatures and irradiation doses are described. Analysis of influence of subsequent and simultaneous irradiation with beams of gas and heavy ions is carried out for investigation of influence of gaseous impurities that form through transmutation nuclear reactions on defected structure evolution under irradiation.