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Abstract
The main innovative features of a new model developed for plutonium dose assessments are presented. The physiological assumptions and the improvement of model predictions for plutonium activity in biological samples are discussed. Preliminary results relating to dose calculations and sensitivity analysis are also presented. The model has been applied to a well documented case of contamination. This was the first opportunity to test the new features of the model in a practical case and to show how to apply sensitivity techniques to a complex data set of a contamination case.
Abstract
The state of trace concentrations of95Zr–95Nb and134Cs was studied at an initial pH>13 in an uranyl triperoxidate medium using the electromigration method. OH– ions governing the potential are adsorbed on the colloidal Nb(V)-hydroxide which leads to an increase in its negative electric charge; while95Zr did not move during the procedure. However, the electrophoretic mobility of the134Cs could be explained in terms of their agglomerations attributed to the interaction of Cs+ ions with water molecules to give larger aggregations.
Abstract
In order to develop an 125I seed for brachytherapy of prostate cancer, a carrier body consisting of Al2O3 and silver powder was developed. To optimize the adsorption conditions of 125I on the rods, various experiments were performed. The adsorption capacity was more than 95% after 4 hours at a volume of 50 μl containing about 5 mCi of 125I. Dosimetric properties were measured for the radial and longitudinal directions. Variations were below 11% in the longitudinal distribution and 5% in the radial distribution. This method is effective for the preparation of 125I seeds to be used in brachytherapy treatment.
Abstract
A radiochemical procedure comprising ion chromatography for preconcentration, oxalate precipitation for alkali/alkaline earth separation, strontium specific extraction chromatography with a crown ether for calcium/strontium separation, carbonate precipitation for counting on a low background proportional counter, provides a simple, rapid (48 h) and effective method for radiostrontium determination in emergency situation in milk. The separation scheme gives a strontium recovery rate of 62% and an empiric relative standard deviation of 11%. The detection limit for 500 ml milk and 3600-second counting time is 0.090 Bq.l-1.
Abstract
The possible association of dental amalgam surface exposure, brain mercury (Hg) levels, and pathological markers of Alzheimer's disease (AD) in the brain is the subject of an on-going study in our laboratory. Two radiochemical neutron activation analysis methods and the use of instrumental neutron activation analysis (INAA) with Compton suppression spectrometry have been evaluated for improving our INAA Hg detection limit (2.8±0.6 ng/g, wet-weight basis) in human tissue. Large numbers of samples dictated the use of a purely instrumental method or rapid, simple radiochemical separations. Human brain tissues and NIST biological standards were analyzed using a precipitation of Hg2Cl2, a solvent extraction utilizing sodium diethyldithiocarbomate, conventional INAA, and INAA with Compton suppression. The radiochemical precipitation of Hg2Cl2 proved to be the most useful method for use in our study because it provided a simultaneous, quantitative determination of silver (Ag) and a Hg detection limit in brain tissue of 1.6±0.1 ng/g (wet-weight basis).
Abstract
Chronic lead (Pb) intoxication has been linked to Alzheimer's disease (AD). Lead, like many heavy elements, tends to accumulate in bone. PIXE is a powerful analytical tool which permits the determination of Pb at the 
g/g level without requiring sample digestion. GFAAS is one of the most sensitive methods for the determination of Pb and is capable of determining ng/g levels in solution. For bone analyses by GFAAS, sample dissolution and a matrix modifier are required. Rib bone samples were analyzed for Pb by PIXE and GFAAS. IAEA Animal Bone (H-5) was used as a secondary standard for Pb with both methods to ensure accuracy. The range of Pb concentrations in human rib bone was 1.4–11.5 g/g for the trabecular surface by PIXE, 1.3–45 g/g for the cortical surface by PIXE, and 1.54–11.75 g/g for whole bone by GFAAS. No significant difference (p>0.05) was found for AD versus control for either surface or for whole bone.
960981A). SEM (Hitachi S-4200) was used to investigate the surface morphology of the PSILs. Reactivity test The synthesis of allyl glycidyl carbonate (AGC or 4-[(prop-2-en-1-yloxy)methyl]-1,3-dioxolan-2-one) from AGE
Introduction Degree of polymerization (DP) is the main factor playing role in the ageing of cellulose fibers. Processes of ageing are associated with the degradation of cellulose macromolecules, increasing the proportion of low
