International Journal of Engineering Research in Africa最新文献

Transient Stability Analysis of an Integrated Photovoltaic Systems in a Power System 电力系统中集成光伏系统的暂态稳定性分析

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International Journal of Engineering Research in Africa Pub Date : 2024-07-25 DOI: 10.4028/p-alnpg0

Sibonakaliso Mzebetshana, Rudiren Sarma

{"title":"Transient Stability Analysis of an Integrated Photovoltaic Systems in a Power System","authors":"Sibonakaliso Mzebetshana, Rudiren Sarma","doi":"10.4028/p-alnpg0","DOIUrl":"https://doi.org/10.4028/p-alnpg0","url":null,"abstract":"Integration of PV systems into the grid is growing rapidly around the world, and PV penetration plays a huge role in minimizing the effect of greenhouse gases in the atmosphere and also contributes to minimizing the impact of load shedding. However, PV systems contribute to grid integration issues such as transients, voltage, and frequency instabilities and reductions in the generator's inertia, respectively; therefore, it is essential to investigate the effect of the PV system on the grid before integrating it. This paper utilized a modified IEEE 9 bus system to investigate the impact of large-scale PV on the power system, and PSCAD software has been used for this study. Four scenarios with different PV penetration levels were considered in this paper. Moreover, for each scenario, the transient stability was assessed based on five parameters, namely: active power, reactive power, rotor angle, rotor speed, and the terminal voltage. Scenario 1 examines the PV systems integrated into a single bus and finds that the optimal PV penetration is 60% of the total power generation. Scenario 2 investigates the effect of integrating PV systems using the optimal PV penetration of 60% distributed into two buses, which was found to be the best for transient stability improvement after a fault condition. Scenario 3 investigates the impact of the power system stabilizer (PSS), using the optimal PV penetration of 60%, and the results reveal that system stability improves when a fault occurs on the bus where the PV system is also connected. Scenario 4 investigates the effectiveness of the fault clearing time on the response of the system with an integrated PV system, using the optimal PV penetration of 60%. The results revealed that a PV system only improves transient stability if the fault-clearing time is below 0.5 seconds; otherwise, the system loses stability. Overall, the study demonstrates that the system’s stability improves up to 60% of the PV penetration level of total generation power.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141803670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enhancing Gold Assaying Crucibles in Ghana: Optimizing Fosu Clay Grog with Sintered Mullite for Improved Performance 改进加纳的黄金化验坩埚：用烧结莫来石优化福苏粘土坩埚以提高性能

IF 0.8

International Journal of Engineering Research in Africa Pub Date : 2024-07-25 DOI: 10.4028/p-ez8uqf

Yong-Dan Hou, L. Gbologah, Derrick Boateng Asante, P. S. Kwawukume

{"title":"Enhancing Gold Assaying Crucibles in Ghana: Optimizing Fosu Clay Grog with Sintered Mullite for Improved Performance","authors":"Yong-Dan Hou, L. Gbologah, Derrick Boateng Asante, P. S. Kwawukume","doi":"10.4028/p-ez8uqf","DOIUrl":"https://doi.org/10.4028/p-ez8uqf","url":null,"abstract":"Due to material and structural issues, fire-assaying crucibles used for analyzing precious metals in ores have encountered challenges related to poor thermal cycling in Ghana’s sub-Saharan region. This study aimed to enhance the crucibles by analyzing aluminosilicate minerals' multiphase development using X-ray diffraction and understanding the effects of composition determined by X-ray fluorescence on thermal behavior and water absorption observed through optical microscopy. The improved crucible design exhibited enhanced thermal cycling stability and lower permeability to the assay charge. Analysis showed that Fosu Clay (FC) demonstrated promise with a favorable Al2O3:SiO2 ratio and low impurities; mullite was identified as the primary phase formed at high temperatures, with quartz and cristobalite also present. Introducing 6% CSM dopant to FC increased the mullite content while supporting the transformation from quartz to cristobalite. The optimal crucible sample included coarse and fine-doped grog with an FC-clay binder, demonstrating excellent thermal stability, adequate porosity, and water absorption. Adjusting the percentage of doped grog further increased mullite content while reducing silica content; this suggests that locally produced improved crucibles are feasible through sintering commercial clay with mullite doping and precise composition adjustments.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141804959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An Analytic Model for the 2-DEG Density Current-Voltage Characteristic for AlGaN/GaN HEMTs AlGaN/GaN HEMT 的 2-DEG 密度电流-电压特性分析模型

IF 0.8

International Journal of Engineering Research in Africa Pub Date : 2024-07-25 DOI: 10.4028/p-s9f14c

Chaimae El Yazami, S. Bri

引用次数: 0

International Journal of Engineering Research in Africa Vol. 70 非洲工程研究国际期刊》第 70 卷

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International Journal of Engineering Research in Africa Pub Date : 2024-07-25 DOI: 10.4028/b-k5mgbk

引用次数: 0

Numerical Finite Element Analysis of Cracked Stainless-Steel Pipe Repaired by GFRP in a Moist Environment 在潮湿环境中用 GFRP 修复开裂不锈钢管的有限元数值分析

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International Journal of Engineering Research in Africa Pub Date : 2024-07-25 DOI: 10.4028/p-poix1c

Abdelouahed Elamine, S. Kaddour, Aour Benaoumeur, H. Benzaama, M. S. Bennouna, Mohamed Mokhtari

{"title":"Numerical Finite Element Analysis of Cracked Stainless-Steel Pipe Repaired by GFRP in a Moist Environment","authors":"Abdelouahed Elamine, S. Kaddour, Aour Benaoumeur, H. Benzaama, M. S. Bennouna, Mohamed Mokhtari","doi":"10.4028/p-poix1c","DOIUrl":"https://doi.org/10.4028/p-poix1c","url":null,"abstract":"Bonding metallic structures with composite materials is widely considered to be the most optimal method for joining damaged and fractured structures. This method offers important advantages, such as reducing the stress intensity factor (SIF) and increasing the lifetime of the joined structure. However, hygrothermal aging is a phenomenon that can reduce the lifetime of reinforced structures made of glass fiber-reinforced polymer (GFRP). This study used numerical modeling to investigate a cracked stainless steel pipe operating in a hygrothermal environment and repaired with three patches. The main objective of this work is to determine the effect of adhesive aging due to hygrothermal damage on the repair efficiency of a cracked SA312 type 304 stainless steel pipe. The Finite Element Method (FEM) is used to evaluate the SIF as a function of applied load for different immersion times and at two different temperatures. First, the developed model was validated against literature results. A parametric study was then carried out. The obtained results showed that the adhesive maintains its stiffness for 7.5 months of immersion and that the mechanical properties of the adhesive are acceptable even at temperatures of 90°C or lower and internal pressures less than or equal to 50 bar. However, when the pressure load exceeds 50 bar (pint > 50 bar), the degradation of the adhesive becomes more significant, and the hygrothermal aging leads to variations in the mechanical properties of the joined structure. It is important to note that these results can contribute to the improvement of the existing composite repair design standard and can provide reliability for the application of GFRP in different humid environments.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141803769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Prediction of Flexural Properties of Additively Manufactured Short Fiber-Reinforced Polymer Composite Parts 加成型短纤维增强聚合物复合材料部件的挠曲性能预测

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International Journal of Engineering Research in Africa Pub Date : 2024-07-25 DOI: 10.4028/p-pils8d

Lucy W. Kariuki, B. Ikua, Samuel K. Karanja, Stephen P. Ng'ang'a

{"title":"Prediction of Flexural Properties of Additively Manufactured Short Fiber-Reinforced Polymer Composite Parts","authors":"Lucy W. Kariuki, B. Ikua, Samuel K. Karanja, Stephen P. Ng'ang'a","doi":"10.4028/p-pils8d","DOIUrl":"https://doi.org/10.4028/p-pils8d","url":null,"abstract":"Fibre-reinforced polymer (FRP) composites have many desirable properties such as high corrosion resistance and a high strength-to-weight ratio. They can also be easily optimised to suit different loading requirements. To produce functional components through 3D printing using FRPs, it is important to optimize the printing process parameters and to predict the mechanical properties of the printed components. The mathematical predictive approach is preferred over experiments it is flexible, fast and not as costly as experiments. In this work, a coupled finite element model for predicting flexural strength properties of additively manufactured parts is developed. The model takes into account the structure, material microstructure, and fused filament fabrication (FFF) process parameters in predicting the flexural strength of parts. The validity of the model is tested using a standard flexural bending specimen and an ankle-foot orthosis (AFO) prototype which are fabricated using short carbon fibre-reinforced polyamide 12 (PA12-CF) filament. The validity of the coupled analysis model was tested by comparing the model predictions of flexural strength with experimental results. The results provide a good prediction of part performance.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141804052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A 4-Dimensional Strategy for Managing Construction Waste Originating during the Design Process within Architectural Design Firms in Egypt 管理埃及建筑设计公司设计过程中产生的建筑垃圾的四维战略

IF 0.8

International Journal of Engineering Research in Africa Pub Date : 2024-07-25 DOI: 10.4028/p-aa0qds

A. Othman, Aya Said Muawad Saad

{"title":"A 4-Dimensional Strategy for Managing Construction Waste Originating during the Design Process within Architectural Design Firms in Egypt","authors":"A. Othman, Aya Said Muawad Saad","doi":"10.4028/p-aa0qds","DOIUrl":"https://doi.org/10.4028/p-aa0qds","url":null,"abstract":"This study aims to develop and validate a comprehensive strategy consisting of four dimensions for effectively managing construction waste (CW) arising during the Architectural Design Process (ADP) within Architectural Design Firms (ADFs) in Egypt. To accomplish this aim, a hybrid research approach, integrating qualitative and quantitative methods, was designed to address four specific objectives. Firstly, a thorough literature review was conducted to explore the topics of ADP, CW, Waste Management (WM), as well as national and international Waste Management Strategies (WMS). Secondly, three construction-based case studies from Saudi Arabia, China, and Thailand were gathered and analyzed to investigate the efficacy of identified WMS in managing CW originating during ADP. Thirdly, a survey questionnaire was administered to a representative sample of ADFs in Egypt to assess their understanding and utilization of WMS during ADP. Finally, the research formulated and validated a four-dimensional strategy for managing CW originating during ADP in ADFs. Data analysis revealed that ADFs possess a moderate level of knowledge regarding WMS, with limited awareness of Egyptian laws, regulations, and WMS during ADP. Among the identified WMS, \"Prefabrication\" emerged as the most favoured, followed by Building Information Modeling (BIM) and \"on-site waste management\". However, the implementation of these strategies faces several challenges. Furthermore, the research identified \"preparation and briefing\" as the design stage most susceptible to CW causes, with \"waiting\" and \"defects\" being the most prevalent forms of CW originating during ADP.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141804580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Geometrical Parameter Optimization of Circular Cross-Section Conformal Cooling Channels in Injection Molds of Plastic Paving Block Molds 塑料铺路块模具注塑模具中圆形截面共形冷却通道的几何参数优化

IF 0.8

International Journal of Engineering Research in Africa Pub Date : 2024-07-25 DOI: 10.4028/p-b6f4rn

Laura W. Simiyu, James M. Mutua, P. Muiruri, B. Ikua, Simon N. Gacharu

{"title":"Geometrical Parameter Optimization of Circular Cross-Section Conformal Cooling Channels in Injection Molds of Plastic Paving Block Molds","authors":"Laura W. Simiyu, James M. Mutua, P. Muiruri, B. Ikua, Simon N. Gacharu","doi":"10.4028/p-b6f4rn","DOIUrl":"https://doi.org/10.4028/p-b6f4rn","url":null,"abstract":"High productivity and product quality are sought after by manufacturers due to the increasing demand for and use of plastic items. Injection molding is the most famous method used to make majority of the plastic items. Injection molding is however known for its lengthy production durations and poor product quality. This study shows the optimization of multiple design characteristics of circular cross-sectioned conformal cooling channels in response to reducing production time while improving product quality, at the same time, using Taguchi design-of-experiments approach. Diameter, depth, and pitch were the three main design variables examined. A Computer Aided Design software was used to create three dimensional designs and to conduct simulations. The responses obtained from simulations were time for cooling to ejection temperature, overall product shrinkage, extents of warpage and dimensions of sink marks. These output parameters were taken as input variables for multi-response optimization utilizing the method of Taguchi Grey Relational evaluation. The outcome obtained revealed that the minimum design variables resulted in the concurrent minimization of all responses for the particular geometry studied. Study of variance showed that the diameter to be the design factor that most significantly influenced all the responses simultaneously. Additionally, it was shown that conformal cooling channels yield better production outcomes than straight cooling channels whereby they gave the minimum cooling time and product defects. The optimized conformal cooling channels, when compared with straight cooling channels, reduced the time to cool the product, product shrinkage, dimension of warpage, and extent of sink marks by 29.35%, 5.99%, 19.77%, and 38.85% respectively.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141802200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Managing Design Changes through Integrating Concurrent Engineering into the Architectural Design Process 通过将并行工程融入建筑设计流程来管理设计变更

IF 0.8

International Journal of Engineering Research in Africa Pub Date : 2024-07-25 DOI: 10.4028/p-3ia6vk

A. Othman, Mariam Sherif Ali

{"title":"Managing Design Changes through Integrating Concurrent Engineering into the Architectural Design Process","authors":"A. Othman, Mariam Sherif Ali","doi":"10.4028/p-3ia6vk","DOIUrl":"https://doi.org/10.4028/p-3ia6vk","url":null,"abstract":"This research aims to investigate the role of concurrent engineering (CE) towards managing design changes (DCs) during the architectural design process (ADP). To achieve this aim, a mixed research approach combining qualitative and quantitative methods was designed to accomplish four objectives. Firstly, the literature review investigated ADP, causes and impacts of DCs and CE. Secondly, three case studies of construction projects from Finland, China and Indonesia were collected and analysed to validate the identified causes and impacts of DCs and examine the role of CE towards managing DCs during ADP. Thirdly, a survey questionnaire was conducted with a representative sample of Architectural Design Firms (ADFs) in Egypt to assess their perception and application of CE as an approach for managing DCs during ADP. Based on the above, the research developed and validated a framework to manage DCs by integrating CE into ADP. Data analysis showed that the “Inability of clients and end-users to comprehend and explain the project requirements due to lack of technical knowledge” and “Inability of clients and end-users to accept advice and guidance” were ranked the highest influential causes of design changes (CDCs). In addition, the “Nature of the traditional procurement approach” and “Insufficient support from the senior management” were ranked the highest challenges of integrating CE in ADFs. These findings informed the research and helped in the development of the proposed framework, which represents a novel and creative synthesis that adds value to knowledge in a way that has not previously occurred.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141804582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Corrosion Rate Prediction in Oil and Gas Pipelines Based on Multiphase Flow Modelling 基于多相流建模的油气管道腐蚀率预测

IF 0.7

International Journal of Engineering Research in Africa Pub Date : 2023-12-18 DOI: 10.4028/p-brqaI1

Martins Obaseki, P. B. Alfred, P. T. Elijah, S. O. Okuma

{"title":"Corrosion Rate Prediction in Oil and Gas Pipelines Based on Multiphase Flow Modelling","authors":"Martins Obaseki, P. B. Alfred, P. T. Elijah, S. O. Okuma","doi":"10.4028/p-brqaI1","DOIUrl":"https://doi.org/10.4028/p-brqaI1","url":null,"abstract":"Corrosion has severe consequences for the integrity of pipelines used in the petroleum industry. Modelling and optimising the parameters of a circulating fluid are two of the numerous methods for combating corrosion. The objective of this study was to develop a multiphase flow simulation model for estimating the corrosion rate of oil and gas pipelines, considering the erosional effect. In addition to carbon dioxide (CO2) and hydrogen sulphide (H2S) corrosion, the present model also takes into account the impacts of chloride concentrations. The current model evaluates and reflects a comprehensive understanding of corrosion in a saline environment, making it readily applicable for estimating corrosion rates for industrial applications. The model's results indicate a prediction accuracy of about 85%. Field data gathered under a broad range of environmental conditions confirms the model's prediction accuracy. The predictions from the present model are in good agreement with the field data. In addition, the present model was found to be more effective than the model created by Dewaard and Milliam. This research is likely to have widespread applications in the oil and gas industry for predicting more accurate corrosion rates.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138994608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0