[en] In X-ray absorption experiment, the dependence of the photoelectric absorption cross-section varied with atomic number Z.In this paper, the dependence on Z of the cross-section or coefficient of photoelectric absorption is first evaluated from published data for (20) elements ranging from Al-Sn, and then the cross-section for Fe is obtained experimentally by measuring the X-ray intensity with and without the Fe absorber and compared with the theoretical value, the variation of the photoelectric absorption coefficient (μ/ρ_m) showed less dependence on Z for the two tested of Z regions.This is because of the inclusion of mass density (ρ_m) of the absorber in the coefficient.The values of m obtained in the present work increases linearly with energy for both ranges of elements

[en] Nowadays proton beam radiation therapy is considered in few centers for management of malignancies. This study is aimed to explore the effect of proton, helium or carbon irradiation on free radicals. This study was conducted in department of Physiology/Medical physics, College of Medicine, Al-Mustansiriya University in Baghdad, Iraq during October 2009. TRIM-SRIM software version 1998 and2003 were used for computed Bragg peak and for calculated the effect of proton, helium and carbon ions against free radicals related to oxygen, nitrogen and halogen species. The lowest stopping power near Bragg's peak of proton targeting free radicals was against superoxide anion and its curve (the stopping power against energy) was shifted down while that of peroxynitrite(ONOO^-) was shifted up. The stopping powers of helium targeting all studied free radicals were lower than corresponding proton irradiation but it required higher energy. Lower stopping power of carbon irradiation targeted hydroxyl(OH^-) and halogenated radicals than the other reactive species were observed. It concludes that such from of external beam irradiation is associated with direct scavenging effect on free radicals of whatever sources.

[en] The aim of this research was to measure the radiation exposure rates in three selected locations in southern part of Iraq (two in Nassireya, and one in Amara) resulted from the existence of depleted uranium in soil and metal pieces have been taken from destroyed tank and study mathematically the concentration of Depleted Uranium by its dispersion from soil surface by winds and rains from 2003 to 2007. The exposure rates were measured using inspector device, while depleted uranium contamination in soil samples and tank's metal pieces were detected with Solid State Nuclear Track Detectors (SSNTDs). The wind and rain effects were considered in the calculation of dispersion effect on depleted uranium concentration in soil, where the wind effect were calculated with respect to the sites nature and soil conditions, and rain effect with respect to dispersive-convective equation for radionuclide and low in soil and metal pieces. The Depleted Uranium concentration in soil and metal pieces have the highest value in Nassireya .The results from dispersion calculation (wind & rain) showed that the depleted uranium concentration in 2008 will be less than the danger level and in allowable contamination range. (author)

[en] Effect of ionizing radiation induced by cobalt-60 (Co-60) on Escherichia coli cells was investigated.A cellular survival curve and mutant frequencies versus absorbed doses were determined.The results showed that the level of bacteria in survival curve decrease to (2) log with gamma ray doses increase and D-value was equals (0.079) Gy.After irradiation the mutant frequencies increased with doses increase, the greatest mutant frequency was 3.4*10^-12 (1 mutation for 0.29*10¹² CFU for 150 μg of rifampicine) induced by (1) Gy, while the smaller was 0.39*10^-12 (1 mutation for 3.41*10¹² CFU for 150 μg of rifampicine) induced by (0.1)Gy

[en] Inhalation of indoor has been recognized as one of the health hazards.In the present work a set of indoor radon measurements was carried out, in different Iraqi houses in Al-Gazalia city/ Baghdad, built of the same type of building materials.Radon concentration determined by using time-integrated passive radon dosimeters containing CR-39 solid state nuclear track detector.Measurements were carried out from September to November 2011.The results show that, the radon concentrations varied from (38.7 to 200) Bq m^-3.The mean values of radon concentrations in second floor hall and first floor of living rooms, Kitchens and bathrooms, were: (46.56±9.13), (68.32±8.55), (128.03±21.65) and (168.92±33.52) Bqm^-3 respectively.This data shows that, bathrooms and Kitchens have significantly higher radon concentration and the second floor is lower radon concentration in all dwellings

[en] In this study, the fission track registration technique with the CR-39 detector are using to determination the uranium concentration for twenty-eight samples of soil distributed in seven districts in Jalawla'a City in Iraq by depth in 5 cm.The uranium concentrations in soil samples measured by using fission tracks registration in (R-39) track detector that caused by the bombardment of (U) with thermal neutrons from (²⁴¹Am-Be) neutron source that has flux of (5*10³ n cm^-2 s^-1).The concentrations values were calculated by a comparison with standard samples.The results showed that the maximum value of uranium is (1.280 ppm) in Al-Talea district and the minimum is (0.719 ppm) in Al-Uruba district

[en] The optical reflection, transmission,and UV/VIS- absorption spectra had been recorded in the wavelength (200-500nm) for PM-355 before and after irradiation with thermal neutrons by using (Am-Be) neutron source of flux (5000n/cm².Sec) for a week, then γ-ray irradiation by using ⁶⁰Co-dose withen range of (20-120Mrad) at normal conditions.The absorption spectra of irradiated samples showed radiation induced absorption changes by photodegradation.There was an increment in absorption proportional with irradiation dose.It was attributed to the interfaces traps, which are formed by thermal neutrons & γ-irradiation.It was found that the absorption and reflectance spectra were in opposite behavior of transmittance.The optical constants (α,K_ex,n,ε,Ε_g,ΔΕ, and Ε_u) were calculated for all samples.The effect of irradiation on the optical constants of the PM-355 before and after irradiation had been discussed and investigated

[en] The gamma ray buildup factor for a point isotopic monoenergetic source (0.1, 1 and 10 MeV) have been studied up to depth of 10mean free paths (mfp) for water, iron, lead, and uranium dioxide (UO₂).Also the exposure buildup factor for gamma radiation in heterogeneous (double layer) shielding were determined for different order of (layer closer to the source consist of either a low atomic number material followed by a high atomic number material or a high atomic number material followed by low atomic number material)

[en] The present study was under taken to measure the uranium concentration in female teeth samples collected from different nationalities.The determination of uranium concentration in these samples has been done by using CR-39 track detector.The nuclear reaction is used as a source of nuclear fission fragments is (n, f) obtained by the bombardment of U-235 with thermal neutrons with flux (5*10³ n/cm² .s) was used from (Am-Be) neutron source.The obtained results show the concentration is ranging from (0.58±0.7ppm) in Oman and Uae to (0.35±0.03ppm)in Iraqi for male, the uranium concentration was the highest in Oman and Uae for female

[en] Blood bank stored RBCs were reported to undergo several changes including RBCs membrane protein changes. The present study was designed to investigate the responses of stored RBCs in term of membrane stability of cells to γ-ray. Stored RBCs for 15 days and 30 days was associated with a significant decrease in the stability of RBCs relative to (fresh RBCs). In addition , 1Gy gamma radiation was associated with a further significant decrease in the stability of 15 days stored RBCs relative to (fresh RBCs). However, an apparent significant increase in the stability was observed for the RBCs stored for 30 days and irradiated by 10 Gy gamma radiation