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

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

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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（核科学与技术国际期刊） 2024年第1期

作者： Emmanuel Kwame Ahiave Emmanuel Ampomah-Amoako Rex Gyeabour Abrefah mathew asamoah

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The Pairing Analysis Improvement of Magnetized Structure in Electromagnetic Bulging Process in Case of Tube with Field Shaper

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Journal of Electromagnetic Analysis and Applications 2024年第4期16卷 43-67页

作者： Blaise Kevine Lenz Soronga Zhanqian Zhan Jing Liu Jonas asamoah Mohamed Bangali Bangura Matala Makiese N’kodia Kambani Chrionie Md Jobayer Hossain Yongdong Chen Program Debugging and Design Department Guangdong Lyric Robot Automation Co. Ltd Huizhou China Electrical and Automation Department China Three Gorges University Yichang China Electronic Department Power Electronic Research Center University of Kent Giles Ln Canterbury UK Program Debugging Department Guangdong Lyric Robot Automation Co. Ltd. Huizhou China Electrical and Computer Engineering Department South China University of Technology Guangzhou China World Standardization Certification and Testing Group (Shenzhen) Co. Ltd. Shenzhen China Electrical Engineering-Power System Mapon University Kindu Democratic Republic of Congo Department of Economy Managment School of Management Computer and Telecomunication Rabbat Marocco Materials Visual Calibration Department Guangdong Lyric Robot Automation Co. Ltd. Huizhou China Program Design Department Guangdong Lyric Robot Automation Co. Ltd. Huizhou China

In the current practical science, the accuracy in the formability of metal alloys being the goal when using electromagnetic forming (EMF) technology, which is a high-speed processing technology that uses Lorentz forces to achieve plastic deformation of sheet metal;according to the previous analysis, the results have shown that in most cases, the Lorentz force acting on the workpiece (metal) is not uniform, there are uneven axial deformations of the metal plates which prevent the rapid advancement of today’s technology. In this article, we presented some advanced analyzes which will lead us to improve the technical solution for the problems of non-uniform axial deformations of the metals in the traditional tube electromagnetic forming technology (EMF). A field shaper is used as a practical forming tool to influence the magnetic field and magnetic pressure distribution, thereby improving the forming ability and result during the electromagnetic forming (EMF) process and we see that induced eddy current control is realized by changing the structural parameters of the magnetic field shaper;which improves the strength and controllability of the magnetic force that acts on the workpiece;thereby a greater radial magnetic pressure can be achieved with field shaper than the case without it;the field shaper regulates the electromagnetic force, the distribution of the magnetic pressure decreases, and the uniform force area of the tube increases which effectively enhances the uniform range of the pipe electromagnetic bulging and the electromagnetic induction coupling between the coil and the metallic workpiece is generally required to produce the Lorentz forces. Using COMSOL Multiphysics® simulation software helped us to accurately represent the real world, simulating multiple physical effects that happened in this model during the process.

关键词： Electromagnetic Forming Field Shaper Lorentz Force Magnetic Pressure Distribution

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Influence of Laser Energy on the Electron Temperature of A Laser-induced Mg Plasma

Influence of Laser Energy on the Electron Temperature of A L...

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作者： Emmanuel asamoah 江苏大学

学位级别：硕士

作为光谱学技术之一,过去几十年激光诱导击穿技术(LIBS)在科学界引起了众多关注。由于在材料加工,生物学,军事,工业分析,医药研究和环境监测等领域的潜在应用。激光诱导击穿技术(LIBS),有时被称作激光等离子体光谱技术(LIPS),利用激光... 详细信息

作为光谱学技术之一,过去几十年激光诱导击穿技术(LIBS)在科学界引起了众多关注。由于在材料加工,生物学,军事,工业分析,医药研究和环境监测等领域的潜在应用。激光诱导击穿技术(LIBS),有时被称作激光等离子体光谱技术(LIPS),利用激光和目标材料相互作用激发的等离子体产生的辐射,来定性定量地分析目标样本的元素组成。LIBS相对其他传统原子发射光谱技术有着众多优势。LIBS同时适用于导电及非导电目标样品分析,仅需较少甚至无需样本制备。LIBS采用了通过一个聚焦透镜聚焦于目标材料的大功率激光脉冲烧蚀目标表面,从而产生等离子体羽。发出的激光诱导等离子体被收集,通过光纤进入光谱仪。利用光谱仪对光进行分析,用以表征和研究样本组成,电子温度和数密度。激光-靶相互作用过程可分类为:表面蒸发(目标材料消融)、等离子膨胀、等离子体辐射及冷却。激光产生等离子的分析性能受几个因素影响:(i)材料性质,(ii)激光参数(能量、压力)。影响发光的的等离子性能大致分为电子密度,电子数密度,以及电子温度。因此等离子温度和电子密度方面的知识对于理解涉及到的物理过程是十分有必要的。本文中,我们将阐述在大气中使用Q开关1064nm波长Nd-YAG激光器,研究激光诱导镁等离子体光谱。通过在不同激光能量以及延时情况下获取光谱图像,研究了等离子体的演化。我们发现光谱线的密度随着延时的增大而减小。利用玻尔兹曼图法确定了电子温度。在延时100ns,激光能量为350mJ的情况下,电子温度达到最高值10164K,并逐渐在500ns时降低至8833.6K。我们同时利用距离函数对镁等离子体进行评价,随着延时从1um到16um,等离子体距离从0.5膨胀至5.5。电子温度和电子数密度分别由玻尔兹曼图和斯塔克展宽法确定。我们的研究中可知,在激光能量为500mJ时,电子温度估计在17556-9785K之间;在激光能量为450mJ时,电子温度估计在17341-8946K之间。电子数密度分别从1.46×10 -1.89×10 cm降低到1.29×10-1.78×1077 cm。从我们的评估中,我们发现镁离子的电子温度随着激光能量的上升而迅速上升。同时也发现,电子温度和数密度随着等离子体膨胀的距离的增大而降低

关键词：激光诱导等离子电子温度发射光谱镁光谱

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The Study of Municipal Solid Waste Management and the Environmental Impacts of Artisanal Gold Mining

The Study of Municipal Solid Waste Management and the Enviro...

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作者： ERIC OWUSU asamoah 江苏大学

学位级别：硕士

城市固体废物管理已成为全球关注的焦点,影响到全球的各个的国家,特别是受影响最严重的发展中国家。大多数国家的经济发展、城市化、人口增长和大规模工业化产生的废物逐渐增加。然而,随着世界的发展,固体废物的增加预计会比想象中的更... 详细信息

城市固体废物管理已成为全球关注的焦点,影响到全球的各个的国家,特别是受影响最严重的发展中国家。大多数国家的经济发展、城市化、人口增长和大规模工业化产生的废物逐渐增加。然而,随着世界的发展,固体废物的增加预计会比想象中的更快。因此,各国有必要探索有效的废物管理措施,因为管理不善的废物会影响到社会发展,如:生态环境、人类健康等。城市固体废物中含有有机成分的温室气体排放已经影响到全球环境。虽然,发达国家有符合国际标准的有效废物处置工具和政策;但,大多数发展中国家,固体废物的收集、分类、运输、处理和处置都存在问题。目前,可持续的废物管理把重点放在废物来源减少,再利用,并通过热应用回收,而不是单纯的废物收集和倾倒或填埋。例如,3Rs原则的有效应用,形成了良好的废物管理的基础,减少废物产生的甲烷、二氧化碳等,从而减少环境中的温室气体,两者的联系错综复杂。因此,本论文探讨了加纳和中国的固体废物问题和前景,两个国家如何更好的相互借鉴废物管理的优势,同时提供一个共同的合作平台,以解决城市固体废物面临的挑战。论文重点介绍了手工金矿(AGM),AGM给所涉社区带来许多社会经济效益,但,其对环境也有很大的影响。AGM带来了水污染、土地退化和空气污染等环境问题,这些问题影响到当地的人类社会发展。但大多数人不知道如何使用替代技术来实现AGM的可持续性发展,加纳作为非洲最高的黄金生产国,对环境的影响是巨大的。因此,本文讨论了AGM活动与环境影响之间的利害关系,并探讨了如何采用替代方法减轻AGM对环境带来的危害,使AGM持续化、规范化发展。

关键词：固体废物回收处置环境影响环境管理环境污染

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Investigation on the Flow Behavior of Side Channel Pumps Based on Vortex Identification

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Chinese Journal of Mechanical Engineering 2021年第6期34卷 298-315页

作者： Fan Zhang Desmond Appiah Ke Chen Shouqi Yuan Kofi asamoah Adu-Poku Lufeng Zhu National Research Center of Pumps Jiangsu UniversityZhenjiang212013China Department of Physics Education University of EducationWinnebaGhana

The momentum flow exchange between the impeller and side channel produces highly turbulent flows in side channel *** turbulent flows feature complex patterns of vortex structures that are partly responsible for the dissipation of energy losses and unsteady pressure *** concept of turbulent flows in side channel pumps requires a reliable vortex identification criterion to capture and predict the effects of the vortex structures on the *** this reason,the current study presents the application of the new Ω-criterion to a side channel pump model in comparison with other traditional methods such as Qand λ2 *** 3D flow fields of the pump were obtained through unsteady Reynolds-averaged Navier-Stokes(RANS)*** studies showed that the Ω-criterion identifies the vortex of different intensities with a standard threshold,Ω=*** Q and λ2 criteria required different thresholds to capture vortex of different intensities thus leads to subjective *** theΩ-criterion intensity on different planes with the entropy losses and pressure pulsation,the longitudinal vortex plays an important role in the momentum exchange development which increases the head performance of the ***,the rate of exchange is impeded by the axial and radial vortices restricted in the ***,the impeller generates the highest entropy loss and pressure pulsation intensities which lower the output ***,the findings provide a fundamental background to the morphology of the vortex structures in the turbulent flows which can be dependent upon for efficiency improvement of side channel pumps.

关键词： Side channel pumps Ω-criterion Vortex Entropy loss

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Olivine Compositional Mapping of Mafic-Ultramafic Complexes in Eastern Xinjiang(NW China):Implications for Cu-Ni Mineralization and Tectonic Dynamics

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Journal of Earth Science 2012年第1期23卷 41-53页

作者： Benxun Su Kezhang Qin He Sun Dongmei Tang Qinghua Xiao Pingping Liu Patrick asamoah Sakyi Key Laboratory of Mineral Resources Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Department of Geology University of GhanaLegon-AccraGhana

Early Permian mafic-ultramafic complexes in eastern Xinjiang （新疆） are mainly distributed in the Beishan （北山） area, Mid-Tianshan （天山） massif and Jueluotage （觉罗塔塔） belt. Systematic compositional mapping of olivines from these Early Permian mafic-ultramafic complexes demonstrates that an apparently spatial distribution and heterogeneous partial melting in the mantle source exists from the Beishan area, across the Mid-Tianshan massif, to the Jueluotage belt from the south to the north. This is probably consistent with the spatial evolutional differences and tectonic features of these three belts. The decreasing degree of partial melting, as revealed by decreasing Fo contents of olivines, from south to north and from east to west reflects the southward subduction of the Paleo-Asian Ocean and the south location of the indistinct mantle plume in the Permian. Simultan ously, NiO and Fo-mapping in olivine also indicates that sulfide segregation before olivine crystallization played an important role in Ni-Cu mineralization in the mafic-ultramafic complexes. Olivines with the compositional range of Fo （77-86） and NiO （less than 0.22 wt.%） are more favorable for Ni-Cu sulfide mineralization.

关键词： mafic-ultramafic complex oli-vine compositional mapping Ni-Cu sulfide min-eralization Beishan Mid-Tianshan massif Jue-luotage belt.

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Zircon Trace Element Constraints on the Evolution of the Paleoproterozoic Birimian Granitoids of the West African Craton(Ghana)

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Journal of Earth Science 2018年第1期29卷 43-56页

作者： Patrick asamoah Sakyi Benxun Su Daniel Kwayisi Chen Chen Yang Bai Melesse Alemayehu Department of Earth Science School of Physical and Mathematical Sciences University of Ghana Key Laboratory of Mineral Resources Institute of Geology and Geophysics Chinese Academy of Sciences School of Earth Science University of Chinese Academy of Sciences School of Applied Natural Science Applied Geology Department Adama Science and Technology University

The Paleoproterozoie Birimian granitoids of the West African Craton （WAC） in the northwestern part of Ghana, have been studied for their zircon trace elements concentrations to infer the source characteristics, origin, and magmatic evolution. The zircons in the granitoids have Th/U ratios ranging from 0.03 to 1.55, and display depleted light rare earth elements 0LREE） and enriched heavy rare earth elements （HREE） contents, characterized by pronounced positive to negative anomalies of Eu （Eu/Eu＊=0.14-0.98 and 1.01-6.06, respectively） and Ce （Ce/Ce＊=0.08-0.98 and 1.02-116, respectively）, which may imply that they were derived from both magmatic and hydrothermal sources. The geochemical plots of U/Yb vs. Y and Hf, the positive correlation between Hf and the other high field strength elements 0tFSE） and high rare earth elements （REE） contents, with enrichment in Ce and depletion in Eu, indicate that the granitoids possibly formed from partial melting of the crust. The trace elements characteristics （i.e., wide range of Hf, Ce/Ce＊, Th/U and Zr/Hf values） of the zircons suggest that crystallization of the magma occurred under variable oxidation states, which spanned over a longer period, implying that our data corroborate interpretations from studies of whole-rock geochemistry and geochronology on the granitoids of northwestern Ghana. This further indicates that the evolution of the Birimian granitoids in this part of the WAC occurred earlier than what had been reported in the literature.

关键词： West African Craton granitoids zircon trace elements magmatic evolution hydro-thermal alteration.

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Transformation of olivine to diopside via interaction with carbonatite melts

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Science China Earth Sciences 2023年第10期66卷 2332-2339页

作者： Jing WANG Ben-Xun SU Sanjeewa P.K.MALAVIARACHCHI Patrick asamoah SAKYI Prasanna L.DHARMAPRIYA Key Laboratory of Mineral Resources Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China University of Chinese Academy of Sciences Beijing100049China Department of Geology Faculty of ScienceUniversity of PeradeniyaPeradeniya20400Sri Lanka Department of Earth Science School of Physical and Mathematical SciencesUniversity of GhanaLegon-AccraGhana

Numerous empirical and experimental studies have documented the consumption of orthopyroxene and production of clinopyroxene in mantle peridotite during carbonatite metasomatism,whereas little attention has been paid to whether and how olivine is compositionally modified through the same process of carbonatite ***,we present the discovery of well-preserved reaction features in olivine from typical calciocarbonatites from Sri *** olivine grains experienced serpentinization along the cracks and in their rims and are generally surrounded outwardly by serpentine,tremolite and diopside *** inner serpentine zone is dominated by serpentine with tiny magnetite,whereas the mantle tremolite zone is characterized by euhedral tremolite and intergrowth of dolomite with small amounts of serpentine relics and *** outer diopside zone shows spongy texture and commonly encloses olivine,serpentine,tremolite and dolomite,which are also observed in interstitial diopside grains in the *** profile analyses reveal that these olivine grains display decreasing FeO and increasing MgO contents and thus elevating Fo values from their cores to the reaction rims,while the serpentine inherits compositions from the *** mapping images demonstrate outward diffusion of Si and Mg in the serpentine zones and contribution of Ca from carbonatite melts during tremolite *** interaction with carbonatite melts produced Si-and Mg-poor and Ca-rich diopside relative to the reactant *** observations suggest that the interaction with carbonatite melts first transformed olivine to diopside through serpentinization,followed by *** diopside formed through olivine-carbonatite melt interaction is anomalously depleted in Na and Al and enriched in Ca,which are distinct from those generated in interactions between orthopyroxene and both carbonatite and silicate *** implies that for the first time some w

关键词： Olivine Carbonatite Diopside Tremolite Melt-mineral interaction

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Analysis of geo-spatiotemporal data using machine learning algorithms and reliability enhancement for urbanization decision support

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International Journal of Digital Earth 2020年第12期13卷 1717-1732页

作者： Kwame O.Hackman Xuecao Li Daniel Asenso-Gyambibi Emmanuella A.asamoah Isaac.D.Nelson Data Management Department WASCAL Competence CenterOuagadougouBurkina Faso Department of Geological and Atmospheric Sciences Iowa State UniversityAmesUSA Department of Environmental Management University of Energy and Natural ResourcesSunyaniGhana Building and Road Research Institute(BRRI) Council for Scientific and Industrial Research(CSIR)KumasiGhana

We present systematic analyses of the temporal dynamics of the growth of Kumasi,the fastest growing city in Ghana using 20-year Landsat timeseries data from 2000 to 2020(with 1986 Landsat image as a baseline).Two classification algorithms–random forest(RF)and support vector machines(SVM)–were used to produce binary(built-up/non-built up)maps for all years within the temporal *** further implemented an anomaly detection and temporal consistency algorithm followed by a changing logic to correct the classification anomalies due to image contamination from the cloud and other *** mean overall accuracies obtained for RF and SVM were 94.9%(kappa=0.90)and 95.5%(kappa=0.91),*** results reveal that the mean builtup area percentages of the metropolis are approximately 74,65,47,and 23 for the years 2020,2010,2000,and 1986,respectively,representing a mean annual change of 3.5%over the 34 *** the present lack of labeled data in Ghana for in-depth analyses of the evolution of land use,we believe that this study serves as an initial attempt to a better understanding of the effects of increasing anthropogenic activities due to urbanization,on human and environment health.

关键词： Urbanization Kumasi support vector machine random forest Landsat

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