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101.
A procedure is described for the functional fitting of reactor neutron spectra with C/En and fission spectra. The method is applied to multicomponent activation detector measurements in a Triga research reactor.
In multicomponent detectors a mixture of several detector materials is irradiated as a single unit and measured simultaneously
for all reaction products with a Ge(Li) gamma ray spectrometer. 相似文献
102.
Bhanja R Joseph R Tuli SK Beri SB Bhatia VS Kaur G Kaur M Mittra IS Bhalla KB Bharti A Lokanathan S Gupta SK Gupta VK Kaul GL Kumar V Mangotra LK Prakash Y Rao NK Sankhydhar S Satti S Claesson G Garpman S Herrström NY Jakobsson B Lund I Norén B Oskarsson A Otterlund I Persson S Sherif MM Söderström K 《Physical review letters》1985,54(8):771-774
103.
104.
Sastry MD Gustafsson H Lund A Lund E 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2004,60(10):2363-2367
With a view to monitoring the changes in coloration caused by the nuclear reaction 51V(n, beta)52Cr in solution of vanadyl sulphate and using it for neutron dosimetry, electronic absorption spectra of vanadyl sulphate solutions were investigated at different concentrations of chromate impurity in micromolar range. It was observed that the presence of chromate enhances the absorptivity over a wide wavelength range serving essentially as a colouring agent for vanadium matrix, presumably due to charge transfer process. The absorbance at 380 nm varied linearly over a wide concentration range. The limit of detection of chromate obtained is shown to be adequate for detecting neutron-induced chemical transmutation of vanadium to chromium under standard reactor conditions, when used with long path length cells. It was observed that the absorbance does not change on electron irradiation, suggesting that radiolytic effects due to beta decay, if any, do not interfere in the measurement of neutron-induced changes. In addition to its potential for neutron dosimetry, this is the first report of a simple and direct method of estimation of Cr in vanadium matrix at sub ppm level. 相似文献
105.
Lund A Olsson S Bonora M Lund E Gustafsson H 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2002,58(6):1301-1311
New materials for electron spin resonance (ESR) dosimetry have been investigated with the aim to find systems more sensitive than L-alanine accepted as a standard for high dose determinations. Among the investigated systems ammonium tartrate, 2-methylalanine, salts of formic acids and dithionates have been found to be more sensitive than alanine by a factor 2-10. The lower limit applies to tissue equivalent materials, while much higher sensitivities were obtained with formates and dithionates containing heavier atoms. The increased sensitivity was mainly attributed to suitable ESR properties of the room temperature stable radicals as regards spectral shape (narrow lines, little or no hyperfine structure) and microwave saturation properties (short relaxation times). The radical structures have when necessary been clarified by ENDOR spectroscopy, while the saturation properties have been screened by pulsed ESR measurements. 相似文献
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107.
Hanne Lund Ann Helene Snilsberg Elisabeth Paus Trine Grønhaug Halvorsen Peter Hemmersbach Léon Reubsaet 《Analytical and bioanalytical chemistry》2013,405(5):1569-1576
The applicability of a mass spectrometry (MS)-based method for determination of various forms of human chorionic gonadotropin (hCG) in doping analysis was demonstrated. A clinical study involving the hCG-containing pharmaceuticals Pregnyl and Ovitrelle was carried out, comprising a single injection of one pharmaceutical per participant to a total of 24 healthy male voluntaries. Hereafter, serum and urine samples were collected over a period of 14 days. The analysis of the samples using immuno-MS demonstrated elimination profiles of intact hCG for both pharmaceuticals, with last day of detection following administration at day 7 in serum, and at day 10 in urine, at limit of detections as defined by the World Anti-Doping Agency. Furthermore, the method allowed detection and differentiation of the various forms of hCG known to be present in serum and urine as a function of metabolism. For both pharmaceuticals, only the intact hCG was detected in serum, whereas in urine the injection of Pregnyl as hCG source (containing urinary hCG, i.e., most hCG variants) was shown to generate a more complex hCG variant pattern compared to Ovitrelle (contains only intact hCG). By detecting hCG using this MS-based approach in doping analysis, strong analytical evidence is provided minimizing the risk of false-positive and false-negative results. 相似文献
108.
Lund Liaquat Ali Omar Zurni Raza Jawad Khan Ilyas 《Journal of Thermal Analysis and Calorimetry》2021,143(2):915-927
Journal of Thermal Analysis and Calorimetry - This study shows multiple solutions, heat transfer characteristics, and stability analysis of the magnetohydrodynamic (MHD) flow of hybrid nanofluid... 相似文献
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110.