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RISS 인기검색어
- 검색키워드
- 저자 : Abdel-Rahman Mohamed A.E. (검색결과 4 건)
- 무료
- 기관 내 무료
- 유료
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Synthesis and Reactions of New Thienopyridines, Pyridothieniopyrimidines and Pyridothienotriazines
Bakhite, E.A.,Abdel Rahman, A.E.,Mohamed, O.S.,Thabet, E.A. Korean Chemical Society 2002 Bulletin of the Korean Chemical Society Vol.23 No.12
4-Aryl-3-cyano-6-(2'-thienyl)-pyridine-2(1H)-thiones(1a-c) were reacted with phenacyl bromide, chloro-N-arylacetanmides or 2-chloroacetylaminopyridine to furnish 2-functionalized 3-amino-4-aryl-6-(2'-thienyl)-thieno[2,3-b]pyridines 4a-c and 5a-c or 5d respecitively. The compounds 5a-d underwent different sequence of reactions to produce a variety of thienylpyridothienopyrimidines and, thienylpyridothienotriazines. Some of the prepared compounds were tested in vitro for their antimicrobial activities.
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Analysis of radioactivity levels and hazard assessment of black sand samples from Rashid area, Egypt
Mohamed A.E. Abdel-Rahman,Sayed A. El-Mongy 한국원자력학회 2017 Nuclear Engineering and Technology Vol.49 No.8
The aim of this study is to evaluate the radioactivity levels and radiological impacts of representative black sand samples collected from different locations in the Rashid area, Egypt. These samples were prepared and then analyzed using the high-resolution gamma ray spectroscopy technique with a highpurity germanium detector. The activity concentration (Ac), minimum detectable activity, absorbed gamma dose rate, external hazard index (Hex), annual effective dose rate equivalent, radium equivalent, as well as external and internal hazard index (Hex and Hin, respectively) were estimated based on the measured radionuclide concentration of the 238U(226Ra) and 232Th decay chains and 40K. The activity concentrations of the 238U, 232Th decay series and 40K of these samples varied from 45.11 ± 3.1 Bq/kg to 252.38 ± 34.3 Bq/kg, from 64.65 ± 6.1 Bq/kg to 579.84 ± 53.1 Bq/kg, and from 403.36 ± 20.8 Bq/kg to 527.47 ± 23.1 Bq/kg, respectively. The activity concentration of 232Th in Sample 1 has the highest value compared to the other samples; this value is also higher than the worldwide mean range as reported by UNSCEAR 2000. The total absorbed gamma dose rate and the annual effective dose for these samples were found to vary from 81.19 nGy/h to 497.81 nGy/h and from 99.86 μSv/y to 612.31 μSv/y, which are higher than the world average values of 59 nGy/h and 70 μSv/y, respectively. The Hex values were also calculated to be 3.02, 0.47, 0.63, 0.87, 0.87, 0.51 and 0.91. It was found that the calculated value of Hex for Sample 1 is significantly higher than the international acceptable limit of <1. The results are tabulated, depicted, and discussed within national and international frameworks, levels, and approaches.
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Searching for the viability of using thorium-based accident-tolerant fuel for VVER-1200
Mohsen Mohamed Y.M.,Abdel-Rahman Mohamed A.E.,Omar Ahmed,Alnassar Nassar,Galahom A. Abdelghafar 한국원자력학회 2024 Nuclear Engineering and Technology Vol.56 No.1
This study explores the feasibility of employing (U, Th)-based accident tolerant fuels (ATFs), specifically (0.8UO2, 0.2ThO2), (0.8UN, 0.2ThN), and (0.8UC, 0.2ThC). The investigation assesses the overall performance of these proposed fuel materials in comparison to the conventional UO2, focusing on deep neutronic and thermal-hydraulic (Th) analyses. Neutronic analysis utilized the MCNPX code, while COMSOL Multiphysics was employed for thermal-hydraulic analysis. The primary objective of this research is to overcome the limitations associated with traditional UO2 fuel by exploring alternative fuel materials that offer advantages in terms of abundance and potential improvements in performance and safety. Given the limited abundance of UO2, long-term sustainable nuclear energy production faces challenges. From a neutronic standpoint, the U–Th based fuels demonstrated remarkable fuel cycle lengths, except (0.8UN, 0.2ThN), which exhibited the minimum fuel cycle length and, consequently, the lowest fuel burn-up. Regarding thermal-hydraulic performance, (0.8UN, 0.2ThN) exhibited outstanding performance with significant margins against fuel melting compared to the other materials. Overall, when considering the integrated performance, the most favourable results were obtained with the use of the (0.8UC, 0.2ThC) fuel configurations. This study contributes valuable insights into the potential benefits of (U, Th)- based ATFs as a promising avenue for enhanced nuclear fuel performance.
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