[en] A new approach is presented for experimental determination of the cadmium correction factor F_Cd using the method of varying Cd thickness. In this method, the shift of the effective Cd cut-off value by varying the Cd thickness was taken into consideration. F_Cd for the following isotopes was determined with 1 mm cadmium covers: ⁷⁵Se, ^110mAg, ^114mIn, ^116mIn, ¹⁵⁴Eu, ¹⁸²Ta and ¹⁹⁸Au. (author)

[en] The late effect of gamma radiation on blood clearance of ^99mTc-sodium pertechnetate (^99mTc-SP) in rats was examined. The disappearance rate of ^99mTc-SP from blood decreased with the increase in dose of ionizing radiation. Changes of the blood clearance of ^99mTc-SP after irradiation treatment in rats may be influenced by the disorder in the hepatocytes rather than in the bile ductule cells. The blood clearance test of ^99mTc-SP in rats showed a sensitive reaction for the acute hepatic dysfunction induced by gamma radiation. (author)

[en] Results of a survey of ²²²Rn concentration using direct measurement in 834 Cairo houses are reported. Although the study was not random with respect to population or land area, it was useful in identifying areas at risk and locating several houses having elevated indoor ²²²Rn air concentrations. Approximately 22% of the houses tested exceeded 37 Bq/m³, with 2.4% exceeding 70 Bq/m³. Several Cairo regions had larger fractions of houses exceeding 49 Bq/m³, such as Madinat Al-Muquattam (44%), Manshiyyat Nasir (31%), Al-Abbasiyyah (29%) and Hadiak Al-Qubbah (17%), Elevated ²²²Rn concentrations were measured for a variety of house types having different construction materials. The effect of water was identified as a potentially significant source of ²²²Rn in Madinat Al-Muquattam homes. This survey is the first by this method in Egypt (a hot region). The indoor concentration of ²²²Rn were measured in homes, in different locations within the flat, also the concentration of radon has been shown to decrease with the increase of the distance of room investigated from ground level with different heights in a tall building during the winter and summer seasons. Indoor radon concentration ranged from 6.32 Bq/m³ to 97.68 Bq/m³ and averaged value with standard deviation was 21.77±7.85 Bq/m³. The concentrations of radon in the unoccupied flats were observed to be considerably higher than those occupied one. (author)

[en] Non-nuclear industries, consuming bulk amounts of raw materials which are high in uranium and emitting waste in the environment, have been identified as significant sources of environmental toxic and radioactive contamination. In Egypt, one of the most important sector of industrial activity responsible for this phenomenon is the phosphoric acid producing industry. Toxic and radioactive lead can be determined in environmental samples without chemical pretreatment using energy dispersive X-ray fluorescence analysis and HPGe-detector. The concentration of lead were determined by energy dispersive X-ray fluorescence technique in blood, water, grains, roadside vegetation (trefoil) and soil. The geometric mean blood lead concentration in non-smoking adult males, 89 μg/l was higher than the 67 μg/l reported for residents of some European or Chinese cities. Lead concentrations in different bodies of water has been studied, as well as guinea corn, soil and vegetation were also lower than values for similar environmental samples from the USA, Western Europe or China. Lead concentrations in roadside soil and the trefoil increased with daily traffic volume and decreased exponentially with distance from the agricultural high way. (author)

[en] By comparison of experimental Ksub(e,0) factors, determined in reactor positions with greatly different thermal-to-epithermal neutron flux ratios, with theoretically calculated Ksub(e,0) factors, it is possible in some cases to select the best values from literature data for (n,γ) activation cross-sections and for absolute gamma intensities. Twenty different isotopes were considered. (author)

[en] Short communication

[en] With the help of reactor neutron activation analysis investigations of the trace elements such as copper, manganese, zinc, selenium, nickel, cadmium and mercury have been performed purposing to settle the problems of distinction between healthy persons and patients suffering from diabetes. In this technique, K_e,₀-method as a new standardization technique, were applied, in which, the deviation of the 1/E^1+α epithermal neutron flux distributions from 1/E law, true coincidence effects of cascade γ-rays, and the efficiency of the Ge-detector were taken into consideration. Short lived nuclides were determined by a short activation with the help of a pneumatic irradiation facility and automatic correction of dead time and decay. The medium and long lived nuclides were determined after 48 h irradiation and ten days cooling. The patients head-hair samples showed a significant differences in the Cu, Zn, Se and Hg. The result indicates that early diagnosis by means of trace elements determination could be possible. (author)

No abstract available

[en] By comparison of experimental Ksub(e,0) factors determined in reactor positions with greatly different thermal-to-epithermal neutron flux ratios, with theoretically calculated Ksub(e,0) factors, it is possible in some cases to select the best values from literature data for (n,γ) activation cross-section and for absolute gamma intensities. Eighteen different isotopes were considered. (author)

[en] High-purity germanium (HPGe) detectors are widely used to determine quantitatively the concentrations of natural and artificial radionuclides in environmental samples. Even with detectors of high performance, it is difficult to measure environmental samples with small activity concentrations. In the case of low-level radioenvironmental measurements at close geometry, much care has to be dedicated to the efficiency calibration of the spectrometer used. This is because the full-energy-peak efficiency is a complicated function of many parameters, such as the energy of gamma-ray, the dimension of the detector, the dimensions of the source, the geometrical arrangement of the detector and source, and the density of the sample. In the present work, the relative efficiency curves for the 10% p-type HPGe detector for environmental samples placed in a cylindrical container were constructed using ⁶⁰Co, ¹³³Ba and ¹⁸²Ta solutions. (author)