An in vitro study of the dose responses of human peripheral blood lymphocytes was conducted with the aim of creating calibrated dose-response curves for biodosimetry measuring up to 4 Gy (0.25-4 Gy) of gamma radiation. The cytokinesis-blocked micronucleus (CBMN) assay was employed to obtain the frequencies of micronuclei (MN) per binucleated cell in blood samples from 16 healthy donors (eight males and eight females) in two age ranges of 20-34 and 35-50 years. The data were used to construct the calibration curves for men and women in two age groups, separately. An increase in micronuclei yield with the dose in a linear-quadratic way was observed in all groups. To verify the applicability of the constructed calibration curve, MN yields were measured in peripheral blood lymphocytes of two real overexposed subjects and three irradiated samples with unknown dose, and the results were compared with dose values obtained from measuring dicentric chromosomes. The comparison of the results obtained by the two techniques indicated a good agreement between dose estimates. The average baseline frequency of MN for the 130 healthy non-exposed donors (77 men and 55 women, 20-60 years old divided into four age groups) ranged from 6 to 21 micronuclei per 1000 binucleated cells. Baseline MN frequencies were higher for women and for the older age group. The results presented in this study point out that the CBMN assay is a reliable, easier and valuable alternative method for biological dosimetry.
We have reviewed the deposition of titanium nitride (TiN) thin films on stainless steel substrates by a DC magnetron sputtering method and annealing at different annealing temperatures of 500, 600, and 700 ∘ C for 120 min in nitrogen/argon atmospheres. Effects of annealing temperatures on the structural and the optical properties of TiN films were investigated using X-ray diffraction (XRD), atomic force microscope (AFM), field emission scanning electron microscopy (FESEM), and UV-VIS spectrophotometer. Our experimental studies reveal that the annealing temperature appreciably affected the structures, crystallite sizes, and reflection of the films. By increasing the annealing temperature to 700 ∘ C crystallinity and reflection of the film increase. These results suggest that annealed TiN films can be good candidate for tokamak first wall due to their structural and optical properties.
Three steps anodization process is used to synthesize highly ordered and uniform multilayered titanium oxide (TiO 2 ) nanotubes and effect of different anodization voltages are studied on their physical properties such as structural, morphological and optical. The crystalized structure of the synthesized tubes is investigated by X-ray diffractometer analysis. To study the morphology of the tubes, field emission scanning electron microscopy is used, which showed that the wall thicknesses and the diameters of the tubes are affected by the different anodization voltages. Moreover, optical studies performed by diffuse reflection spectra suggested that band gap of the TiO 2 nanotubes are also changed by applying different anodization voltages. In this study using physical investigations, an optimum anodization voltage is obtained to synthesize the uniform crystalized TiO 2 nanotubes with suitable diameter, wall thickness and optical properties.
Improved properties of aluminum zinc oxide (AZO) thin films deposited by the magnetron sputtering at room temperature are reported. AZO is one of the most promising transparent conducting oxide materials, which widely used in thin film solar cells. In this study the optimization process of the DC magnetron sputtered AZO films was carried out at room temperature by studying its structural, optical, electrical and morphological properties at different deposition times (5, 10, 15, 20 and 25 min). It can be utilized as a front contact for the cadmium telluride (CdTe) based thin film solar cells. The structural study shows that the preferred orientation of grains is along plane (002), with a hexagonal structure of the grains. The electrical and optical characteristics show that the films has an average transmission of 70 % and a resistivity of the order of 10 -4 X cm. The morphology analysis suggests the formation of packed grains with a homogeneous surface.
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