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Journal of Energy and Power Engineering 2011年第6期5卷 528-535页

作者： N. Afghan S.A. Mallick M.A. Habib Institute of Business Administration （IBA） Karachi 75270 Pakistan Pakistan nuclear regulatory authority （PNRA） Islamabad 44000 Pakistan

The purpose of this paper is to define a leadership competency framework for nuclear within Pakistan nuclear regulatory authority （PNRA）. It provides arguments for a more holistic approach towards leadership development in nuclear organization. It further provides leadership framework that can be used （adapted/adopted） by other regulatory bodies for developing leadership within the organization. It is expected that new countries embarking on nuclear power programme will especially find this interesting and useful as they will also face similar challenges as faced by Pakistan nuclear regulatory authority during its formative year. Paper further provides insights into the process of leadership development in organization. It is suggested that an integrated approach is important to develop nuclear leadership within the organization. It was also found that an effective leadership development program is not only long process but requires commitment from top leadership. Leadership gap analysis, providing open feedback and action learning project were important elements for leadership development.

关键词： PNRA NRC leadership.

Assessment of Axial Power Peaking Factors in GHARR-1 LEU Core: A Decadal Simulation Analysis

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World Journal of nuclear Science and Technology 2024年第1期14卷 72-85页

作者： Emmanuel Kwame Ahiave Emmanuel Ampomah-Amoako Rex Gyeabour Abrefah Mathew Asamoah Department of Mathematics and Statistics Ho Technical University Ho Ghana Department of nuclear Engineering Graduate School of Nuclear and Allied Sciences University of Ghana Accra Ghana nuclear regulatory authority Accra Ghana National nuclear Research Institute Accra Ghana

This study aims to thoroughly investigate the axial power peaking factors (PPF) within the low-enriched uranium (LEU) core of the Ghana Research Reactor-1 (GHARR-1). This study uses advanced simulation tools, like the MCNPX code for analysing neutron behavior and the PARET/ANL code for understanding power variations, to get a clearer picture of the reactor’s performance. The analysis covers the initial six years of GHARR-1’s operation and includes projections for its whole 60-year lifespan. We closely observed the patterns of both the highest and average PPFs at 21 axial nodes, with measurements taken every ten years. The findings of this study reveal important patterns in power distribution within the core, which are essential for improving the safety regulations and fuel management techniques of the reactor. We provide a meticulous approach, extensive data, and an analysis of the findings, highlighting the significance of continuous monitoring and analysis for proactive management of nuclear reactors. The findings of this study not only enhance our comprehension of nuclear reactor safety but also carry significant ramifications for sustainable energy progress in Ghana and the wider global context. nuclear engineering is essential in tackling global concerns, such as the demand for clean and dependable energy sources. Research on optimising nuclear reactors, particularly in terms of safety and efficiency, is crucial for the ongoing advancement and acceptance of nuclear energy.

关键词： GHARR-1 Power Peaking Factor nuclear Reactor Safety Low Enriched Uranium Core Operational Longevity Thermal Hydraulics

Modeling and simulation of induction motor drive system to investigate and mitigate of PWM inverter’s adverse effects

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Journal of Harbin Institute of Technology(New Series) 2007年第1期14卷 83-88页

作者： ESMAELI Abdolreza 孙力 Dept. of National Radiation Protection Iranian Nuclear Regulatory Authority

Modeling and simulation of induction motor drive system to investigate and mitigate the adverse effects of PWM inverter based on analysis, modeling and simulation are presented. The estimation of conducted disturbances and other adverse effects of PWM inverter by simulation offer a considerable gain from the economic point of view. For an accurate model of the motor drive system including mains, rectifier, inverter, motor and its long cables, the high frequency parasitic current paths are taken into account. The novel model and its parasitic values for three-phase induction motor system are presented. Finally a new solution for suppressing EMI, common mode voltage, leakage current, bearing current and shaft voltages is proposed and the results show the excellent performances of proposed solution including active and passive filters.

关键词： induction motor PWM inverter adverse effects EMC high frequency model

Pion emission in α-particle interactions with various targets of nuclear emulsion detector

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Chinese Physics C 2015年第9期39卷 35-42页

作者： A.Abdelsalam Z.Abou-Moussa N.Rashed B.M.Badawy H.A.Amer W.Osman M.M.El-Ashmawy N.Abdallah Physics Department Faculty of Science Cairo University Mohamed El-Nadi High Energy Lab Faculty of Science Cairo University Physics Department Faculty of Science Fayoum University Reactor Physics Department Nuclear Research Center Atomic Energy Authority nuclear and Radiological regulatory authority NRRA

The behavior of relativistic hadron multiplicity for 4He-nucleus interactions is investigated. The experi- ment is carried out at 2.1 A and 3.7 A GeV （Dubna energy） to search for the incident energy effect on the interactions inside different emulsion target nuclei. Data are presented in terms of the number of emitted relativistic hadrons in both forward and backward angular zones. The dependence on the target size is presented. For this purpose the statistical events are discriminated into groups according to the interactions with H, CNO, Em, and AgBr target nuclei. The separation of events, into the mentioned groups, is executed based on Glauber＇s multiple scattering theory approach. Features suggestive of a decay mechanism seem to be a characteristic of the backward emission of relativistic hadrons. The results strongly support the assumption that the relativistic hadrons may already be emitted during the de-excitation of the excited target nucleus, in a behavior like that of compound-nucleus disintegration. Regarding the limiting fragmentation hypothesis beyond 1 A GeV, the target size is the main parameter affecting the backward production of the relativistic hadron. The incident energy is a principal factor responsible for the forward relativistic hadron production, implying that this system of particle production is a creation system. However, the target size is an effective parameter as well as the projectile size considering the geometrical concept regarded in the nuclear fireball model. The data are analyzed in the framework of the FRITIOF model.

关键词： α-particle interactions at Dubna energies shower particle sources target size dependence FRITIOFmodel

Determination of gamma ray spectrometry efficiency for the attenuation coefficients of some bismuth borate glasses by MCNP and(ISOCS)techniques

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Radiation Detection Technology and Methods 2018年第2期2卷 67-74页

作者： Ahmed Y.El-Haseib Z.Ahmed Yasser B.Saddeek Radiation Safety Department Egyptian Nuclear and Radiological Regulatory Authority(ENRRA)Nasr CityCairoEgypt nuclear Safeguards and Physical Protection Department Egyptian Nuclear and Radiological Regulatory Authority(ENRRA)Nasr CityCairoEgypt Physics Department Faculty of ScienceAl-Azhar UniversityAssiut 71524Egypt

Background Radiation detection has been a main interest for researchers as all kind of produced particles in atomic and subatomic physics based on the measurement systems so-called *** efficiency is one of the main parameters in detection system besides many other different parameters of the *** detector in experimental physics is an instrument that converts radiation energy into an electrical signal,and this is achieved basically by either ionization or *** choice for any type of a detector(gas-filled,scintillation or semiconductor)for any application depends upon the X-ray of gamma energy range of interest.A working model is therefore developed which is capable of describing the overall NaI(Tl)detection efficiency as a function of several known *** The attenuation coefficients for the bismuth borate glasses with different concentrations were measured using gamma spectroscopy *** numerical absolute efficiency calibration of a detector can be determined by In-Situ Object Calibration Software(ISOCS)and Monte Carlo Neutral Particle version 5(MCNP5)techniques which does not require any calibration standards or reference *** By using the ISOCS and MCNP5 methodologies,the full energy peak efficiency of a scintillator detector(3“X3”NaI(Tl))exposed to Co-60 and Cs-137 gamma ray sources with average accuracy range 0.126–1.224%for the used samples can be *** used materials are ternary and are located between the detector and the source to determine the attenuation coefficients for these samples by using the calculated full energy peak efficiencies of a *** The average accuracy ranged from−1.808 to 1.960%for linear attenuation coefficient(μ),while it ranged from−1.999 to 1.888%and from−1.924 to 1.960%for half value layer(HVL)and mass linear attenuation coefficient(μm),*** The calculated values of the absolute full energy peak efficiency have been used to determi

关键词： Detection efficiency Sodium iodine(NaI) Linear attenuation coefficient(μ) Mass linear attenuation coefficient(μm) Half-value layer(HVL)

An Interior-Point Algorithm for Linear Programming with Optimal Selection of Centering Parameter and Step Size

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Journal of the Operations Research Society of China 2021年第3期9卷 659-671页

作者： Ya-Guang Yang nuclear regulatory Commission Office of ResearchRockville 20850USA

For interior-point algorithms in linear programming,it is well known that the selection of the centering parameter is crucial for proving polynomiality in theory and for efficiency in ***,the selection of the centering parameter is usually by heuristics and separated from the selection of the line-search step *** heuristics are quite different while developing practically efficient algorithms,such as Mehrotra’s predictor–corrector(MPC)algorithm,and theoretically efficient algorithms,such as short-step path-following *** introduces a dilemma that some algorithms with the best-known polynomial bound are least efficient in practice,and some most efficient algorithms may not be convergent in polynomial ***,in this paper,we propose a systematic way to optimally select the centering parameter and linesearch step size at the same time,and we show that the algorithm based on this strategy has the best-known polynomial bound and may be very efficient in computation for real problems.

关键词： Interior-point method Convergence Polynomial algorithm Linear programming

Assessment of the Heavy Metals and Natural Radioactivity in Phosphate Mines and Occupational Health Effects at Some Egyptian Regions

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Journal of Environmental Protection 2016年第11期7卷 1657-1669页

作者： E. R. Atta Kh. M. Zakaria M. S. Ibrahim nuclear and Radiological regulatory authority Cairo Egypt

In this work, the specific activities of natural radionuclides, namely 238U series, 232Th series and 40K, have been measured in collected sedimentary phosphate deposits samples from El-Hamraween, El-Quser and Safaga phosphate mines in Egypt. HPGe γ-spectrometry was used. This study was undertaken to estimate the radiation hazard indices in phosphate mining at the studied mines on their occupational workers, to establish correlation relationships between the some measured heavy metals such as As, Cd and Pb in blood workers and their concentration in phosphate rock ores and to determinate the biomarkers in the blood workers such as malondialdehyde (MDA) and superoxide dismutase (SOD). The phosphate mine sample of El-Hamrawein has the lowest activity concentration of 226Ra, 232Th and 40K in comparison to the phosphate mine samples of El-Quseir and Safaga (El-Hamrawein kg-1, 122.4 to 188.3 Bq·kg-1 and 115.4 to 165.8 Bq·kg-1 for Safaga, El-Quseir and El-Hamrawein, respectively. For 232Th activity concentrations varied from 135.6 to 212.3 Bq·kg-1, 112.8 to 167.4 Bq·kg-1 and 132.8 to 188.6 Bq·kg-1 for Safaga, El-Quseir and El-Hamrawein, respectively. For 40K activity concentrations varied from 225.2 to 312.8 Bq·kg-1, 168.7 to 268.9 Bq·kg-1 and 95.2 to 155.8 Bq·kg-1 for Safaga, El-Quseir and El-Hamrawein, respectively. The workers of old ages have higher concentration of the investigated heavy metals than those of young ages. There is a good relation between the concentration of the investigated metals in phosphate mine samples and their concentration in blood of the occupational workers in these mines.

关键词： Superoxide Dismutase Malondialdehyde Natural Radionuclides Heavy Metals Phosphate Occupational Workers Health Effects

Comparative Study between Lead Oxide and Lead Nitrate Polymer as Gamma-Radiation Shielding Materials

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Journal of Environmental Protection 2016年第2期7卷 268-276页

作者： A. M. Madbouly E. R. Atta Egyptian nuclear and Radiological regulatory authority Cairo Egypt

In this work, the Styrene-butadiene rubber (SBR)/lead oxide and the Styrene-butadiene rubber (SBR)/lead nitrate composites were prepared as gamma-radiation shielding materials. The investigated materials were prepared with three different weight percentage of lead oxide and lead nitrate (30, 50 and 70 wt%). The mass attenuation coefficients (μm) for all composite samples were measured experimentally at 511 and 661.6 keV photon energies. The measurements were made by performing transmission experiments with a 3'' × 3'' NaI (Tl) scintillation detector, which had an energy resolution of 7% at 0.662 MeV for the gamma-rays from the decay of 137Cs. The effective atomic numbers (Zeff) and the effective electron densities (Neff) were determined experimentally. Also they were determined theoretically using the obtained μm values for the studied composites samples by WinXCom program. The obtained results show that the experimental values of the composites are found to be in a good agreement with the theoretical values. It is recognized that the mass attenuation coefficient (μm), effective atomic numbers (Zeff) and the effective electron densities (Neff) are increased in the composite samples which contain lead oxides than which contain lead nitrates. Finally, the Styrene-butadiene rubber (SBR)/lead oxide is better than Styrene-butadiene rubber (SBR)/lead nitrate polymer as gamma radiation shielding.

关键词： Leads Oxide Lead Nitrate Mass Attenuation Coefficient Electron Density Effective Atomic Number XCOM Program Gamma Ray Shielding

Evaluation of Some Radioactive Materials and Heavy Metals in Marine Environment of Alexandria Coastline, Egypt

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Journal of Environmental Protection 2014年第17期5卷 1618-1629页

作者： E. R. Atta Kh. M. Zakaria Egyptian nuclear and Radiological regulatory authority Cairo Egypt

The present work is carried out to obtain quantitative information of some natural radioactive materials and heavy metals in water and sediment samples along the Alexandria Coastline, as a step to construct the baseline map of the background radioactivity level in the Egyptian environment and also as a base data to assess the future physicochemical changes of surface coastal water and sediment in the studied area. The distribution of natural gamma emitting radionuclides such as 238U, 232Th and 40K has been established by gamma spectrometry. The results show that the area of Alexandria coast is affected by the existence of high back-ground radiation from the Rashid coast at the eastern side which has high levels of radioisotope concentrations due to black sand deposits which are dominant in this area. The absorbed dose rate (D, nGy·h-1), annual effective dose equivalent, external hazard index (Hex) and representative level index (Ir) of the investigated radioactive materials were calculated. The concentration of Pb2+, Cd2+, Ni2+, Mn2+, Cu2+, Co2+, Zn2+ and Cr3+ ions has been determined using Atomic Absorption Spectroscopy. The total dissolved solids (TDS) in water samples ranged from 33,000 mg/l to 42,000 mg/l, the salinity ranged from 37.9% to 40.5% and pH ranged from 7.6 to 7.9. Some of the sediment quality guidelines are calculated and they are the metal pollution index (MPI), the contamination factor (CF), degree of contamination (Cdeg), and Pollution load index (PLI).

关键词： Mediterranean Sea Water Sediment Radioactive Materials Heavy Metals Sediment Quality Guidelines

Cell fate regulation governed by p53: Friends or reversible foes in cancer therapy

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Cancer Communications 2024年第3期44卷 297-360页

作者： Bin Song Ping Yang Shuyu Zhang Laboratory of Radiation Medicine West China Second University HospitalSichuan UniversityChengduSichuanP.R.China The Second Affiliated Hospital of Chengdu Medical College China National Nuclear Corporation 416 HospitalChengduSichuanP.R.China Laboratory of Radiation Medicine NHC Key Laboratory of Nuclear Technology Medical TransformationWest China School of Basic Medical Sciences&Forensic MedicineSichuan UniversityChengduSichuanP.R.China

Cancer is a leading cause of death *** therapies aimed at key oncogenic driver mutations in combination with chemotherapy and radiother-apy as well as immunotherapy have benefited cancer patients *** protein p53(TP53),a crucial tumor suppressor gene encoding p53,reg-ulates numerous downstream genes and cellular phenotypes in response to various *** affected genes are involved in diverse processes,includ-ing cell cycle arrest,DNA repair,cellular senescence,metabolic homeostasis,apoptosis,and ***,accumulating recent studies have contin-ued to reveal novel and unexpected functions of p53 in governing the fate of tumors,for example,functions in ferroptosis,immunity,the tumor microenvi-ronment and microbiome *** the possibilities,the evolutionary plasticity of p53 is the most controversial,partially due to the dizzying array of biological functions that have been attributed to different regulatory mechanisms of p53 *** 40 years after its discovery,this key tumor suppressor remains somewhat *** intricate and diverse functions of p53 in reg-ulating cell fate during cancer treatment are only the tip of the iceberg with respect to its equally complicated structural biology,which has been painstak-ingly ***,TP53 mutation is one of the most significant genetic alterations in cancer,contributing to rapid cancer cell growth and tumor ***,we summarized recent advances that implicate altered p53 in modulating the response to various cancer therapies,including chemotherapy,radiotherapy,and ***,we also discussed potential strategies for targeting p53 as a therapeutic option for cancer.

关键词： cancer chemotherapy drug targeting immunotherapy p53 tumor suppressor