International Journal of Engineering Research in Africa最新文献

{"title":"Mitigation of Reactive Power and Harmonics in a Case of Industrial Customer","authors":"Dessalegn Bitew Aeggegn, Ayodeji Olalekan Salau, Y. Gebru, T. Agajie","doi":"10.4028/p-j716jb","DOIUrl":"https://doi.org/10.4028/p-j716jb","url":null,"abstract":"In most industrial plants, power quality is a major issue which hinders productivity and efficiency of the plants due to the use of semiconductor based loads and non-linear loads. As a result, to address the power quality problems in these industries, specialized power devices such as the Unified Power Quality Conditioner (UPQC), can be installed at the customer's location to resolve practically all power quality issues. UPQC consist of a series of active power filters (APF) which mitigate voltage quality issues and shunt active power filters which are used to reduce current quality issues, like harmonics and reactive power burdens. This paper, therefore presents an investigation and assessment of the power quality problems associated with Bahir Dar Textile Share Company. This was achieved by examining the voltage and current harmonic levels of various types of loads using PI and fuzzy logic controllers by measuring the level of total harmonic distortion (THD) with and without the insertion of the UPQC. The novelty of this paper is the implementation of the controller based customized UPQC for power factor and reactive power compensation. It was observed that by designing the system without and with UPQC, the results of the FFT analysis show that the fuzzy logic controller (FLC) reduced the harmonics level of the load voltage and current by 1.10% and 2.14% respectively. Generally, harmonics was alleviated by 90%, reactive power was reduced by 20%, and power factor was improved by 33%. Hence, the proposed UPQC is capable of holding the voltage and current harmonics levels within the acceptable limit, which satisfies the standards imposed by IEEE 519-1995.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49521863","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}

{"title":"New Mobile Cloud Computing Approach Based Multi-Agent System For OWL-S Services","authors":"Souraya Hamida, O. Kazar","doi":"10.4028/p-w76ja7","DOIUrl":"https://doi.org/10.4028/p-w76ja7","url":null,"abstract":"Using mobile cloud technology, local application resources can move into the cloud computing resource pool in the form of web services. The web services discovery and execution processes in the mobile environment are considered as a very difficult challenge. Moreover, these processes may degrade network performance due to the mobile environment. To overcome these issues, we present a new approach for better discovery, selection, execution, and negotiation of OWL-S services by utilizing a multi-agent system in mobile cloud computing. By using the Multi-Agent System (mobile agent and fixed agent), these processes are made with the minimum utilization of resources because the mobile agents migrate to targeted services and interact locally with them. Moreover, the use of mobile agent overcomes the problems related to the mobile environment and wireless devices. Besides, it automatizes the discovery, selection, execution, and negotiation of OWL-S services. The obtained results demonstrate the effectiveness of the proposed system. Moreover, we conclude that the mobile agent is a good solution to eliminate the problem of wireless devices and the mobile environment, and reduced the execution time of service discovery and invocation. Also, the finding indicates that cloud computing is a good solution to eliminate the problem of storage and execution in mobile devices. Besides, the context-aware provides a more accurate service selection.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70641596","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}

{"title":"Optimal Design and Techno-Economic Analysis of a Grid-Connected Photovoltaic and Battery Hybrid Energy System","authors":"T. Adefarati, Gulshan Sharma, A. K. Onaolapo, Ambrose Njepu, K. Akindeji, S. Oladejo, G. Obikoya, I. Adeyanju","doi":"10.4028/p-5v245g","DOIUrl":"https://doi.org/10.4028/p-5v245g","url":null,"abstract":"The application of green energy technologies (GETs) has been accepted universally due to the industrial revolution, increasing energy demand, high standard of living, population growth and fluctuation of crude oil prices. In view of this, GETs have been recognized on a global note as a promising and significant alternative to meet ever increasing power demand. This research work is aimed at optimal operation and design of hybrid renewable energy system (HRES) to enhance the performance of the power system while taking into consideration the energy produced, levelized cost of energy (LCOE), return on investment (ROI), solar fraction (SF), net present value (NPV), payback period and saved CO2 emissions based on the photovoltaic (PV) orientation. This is due to the fact that the solar panel generates more electrical output when its surface is perpendicular to the solar radiation. The PV orientation significantly affects the output of a solar farm, for this reason, fixed tilted plane, vertical axis tracking system and two axes tracking system are proposed in this research work to estimate their effects on the technical, economic and environmental performance of HRES. This paper presents a grid-connected HRES that comprises utility grid, PV, battery system (BS) and load. The modelling and simulation of HRES are implemented by using PVsyst.7 energy tools in conjunction with the meteorological data made available by the National Aeronautics and Space Administration (NASA). The research outputs show that the two axes tracking system is more techno-economic feasible when compared with the fixed tilted plane and vertical axis tracking system based on the following results: Energy obtained from the grid of 4.657 MW/yr, LCOE of 0.075 ZAR/kWh, ROI of 862.7%, SF of 0.6781, NPV of 828,881.74 ZAR, payback period of 3.5 years and carbon balance of 732.240 tons. The outcomes of the study can be used by the power system planners and designers as benchmarks to utilize the prospect of solar resources for power sector reform and the industrial revolution.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46214449","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}

{"title":"Demand Forecasting Application with Regression and IoT Based Inventory Management System: A Case Study of a Semiconductor Manufacturing Company","authors":"Asmae El Jaouhari, Z.A. Alhilali, Jabir Arif, Soumaya Fellaki, Mohamed Amejwal, Khaoula Azzouz","doi":"10.4028/p-8ntq24","DOIUrl":"https://doi.org/10.4028/p-8ntq24","url":null,"abstract":"The accuracy of demand forecasting has a significant impact on the supply chain system's performance, which in turn has a major effect on company performance. Accurate forecasting will allow the organization to make the best use of its resources. The synchronization of customer orders to support production is critical for on-time order fulfillment. However, In fact many organizations report that their forecasting method is not working as effectively as they had hoped because orders regularly alter due to client demands. The purpose of this paper is to present an Internet of Things (IoT)-based inventory management system (IMS) that combines a causal method of multiple linear regressions (MLR) with genetic algorithms (GA) to improve the accuracy of demand forecasting in the future period by the customer as closely as feasible and enable smart inventory for Industry 4.0. Based on the data gathered from a semiconductor company that specializes in low-volume, high-mix contract manufacturing equipment and services integration, the suggested IoT-based IMS indicates that inventory productivity and efficiency could be enhanced, and it is resilient to order fluctuation.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47131695","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}

{"title":"Mixed Convective Heat Transfer in a Lid-Driven Concentric Trapezoidal Enclosure: Numerical Simulation","authors":"O. Olayemi, K. Al‐Farhany, S. E. Ibitoye, A. Obalalu","doi":"10.4028/p-kybe41","DOIUrl":"https://doi.org/10.4028/p-kybe41","url":null,"abstract":"This study investigates the implications of the area ratio (AR) and Grashof number (Gr) on fluid flow properties and heat transfer due to mixed convection around heated trapezoidal blocks located concentrically inside a larger trapezium driven by a lid. The outer trapezium's upper and lower horizontal walls are moving in opposite directions. The model developed was solved using the finite element technique. The inner walls of the trapezium are retained at an isothermal temperature, while the slanted outer walls of the trapezium are perfectly insulated. The upper and lower walls of the enclosure are subjected to normalized sinusoidal temperatures. Grashof number in the range of 103£Gr£105 and area ratios ( ) of , and were investigated. The simulation outcomes are displayed as stream function, isothermal contours, and local Nusselt number. Considering the interval of for the inner block, the Nusselt number increase with diminishing area ratio for the upper wall, while the response of the lower wall to Gr variation is a function of the AR considered. At the bottom wall of the outer trapezium, results showed that the rate of heat transfer was not significantly affected by changes in area ratio. Furthermore, as the AR reduces, the heat transmission along the top wall of the outer trapezium improves with the Grashof number, with the least and peak heat transfer enhancements occurring at 50 % and 100 % percent of the wall length, respectively.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48071189","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}

{"title":"Welding Defects Detection in Radiographic Images Using an Improved Denoising Technique Combined with an Enhanced Chan-Vese Model","authors":"Rabah Abdelkader, N. Ramou, Mohammed Khorchef","doi":"10.4028/p-w863h3","DOIUrl":"https://doi.org/10.4028/p-w863h3","url":null,"abstract":"The detection of welding defects is becoming an important operation in the industry and the field of non-destructive testing. Among the most used techniques in the detection of weld defects, it is radiography. The radiographic images acquired are generally of low contrast, poor quality, and uneven lighting. Therefore, the detection of welding defects becomes a difficult task. In this work, a new hybrid approach based on the combination of several techniques is proposed. It consists of three stages: firstly, we define the region of interest (ROI). Secondly, a preprocessing operation based on an improved version of denoising by soft thresholding of wavelet coefficients and an optimized threshold is applied to improve the image quality (noise reduction, contrast enhancement). Thirdly, an enhanced Chan-Vese model is proposed to segment the denoised ROI region. This enhanced model is based on the choice of a cluster obtained by the Fuzzy C-Mean algorithm (FCM) as the initial contour. The proposed approach is applied to the various radiographic welding images from the GDxray database to extract the characteristics of the welding defects. The results obtained clearly show the effectiveness of the proposed approach compared to conventional techniques.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47040251","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}

{"title":"Testing, Evaluating and Simulate the Performance of the Newly Designed Drum for a Sunflower Threshing Machine","authors":"Khaled Abdeen Mous Ali, Wangyuan Zong, Li Na Ma, G. G. Abd El-Wahhab, Mao Li","doi":"10.4028/p-8s4erw","DOIUrl":"https://doi.org/10.4028/p-8s4erw","url":null,"abstract":"The stationary thresher machines are widely used worldwide in threshing and separating many crops; they proved to have a high performance, especially in small spaces. The threshing drum is the essential working device of the thresher and plays a fundamental role in threshing efficiency, consumed specific energy, machine productivity, and seeds loss. In this study, a structure of sunflower thresher (open style drum with 45 incline degree loop teeth) was tested, and evaluated for performance under different drum rotational speeds (150, 200, 250, and 300 rpm) and different concave clearances ( 10, 15 and 20 mm). The thresher structure and operating parameters were assessed and optimized concerning damaged and unthreshed seed percentage, threshing efficiency, consumed specific energy, and machine productivity. The obtained results revealed that increasing cylinder rotating speed positively related to threshing efficiency, power requirements, and machine productivity while increasing concave negatively related to threshing efficiency, power requirements, and machine productivity. The highest efficiency of 97.40 %, the maximum productivity of 434.50 kg/h, and the lowest consumed specific energy of 6.85 kW.h/t were obtained at the operational condition of 300 rpm drum rotational speed 10 mm concave clearance. Buckingham's π theorem was followed to find an equation to predict the threshing efficiency theoretically, resulting in an equation with an R2 value of 0.8892. These developments were an excellent choice to uprising the performance of the original thresher drum.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45027450","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}

{"title":"Experimental Investigation of Machining Time and Optimization of Machining Parameters Using RSM and Genetic Algorithm (GA) on 2205-Duplex Stainless Steel","authors":"Mahesh Gopal, E. M. Gutema, Yigrem Solomon","doi":"10.4028/p-9933yq","DOIUrl":"https://doi.org/10.4028/p-9933yq","url":null,"abstract":"Duplex stainless steel has become one of the fastest-growing materials in the stainless steel family due to pitting resistance, stress-corrosion cracking, the combination of excellent mechanical properties, production features, and the area of applications such as oil and gas, nuclear and thermal power plants, chemical processing industries, saltwater processing industries, and pipeline systems. However, it is more difficult to machine due to its high toughness, low thermal conductivity, and ductility. The experiment has conducted using 2205- Duplex Stainless steel round bar material considering carbide cutting tools using Computer Numerical Control lathe to estimate machining time to address and meet the industrial need. Using Central Composite Designed by using Response Surface Methodology technique develops a second-order mathematical model based on the machining parameters. The Analysis of Variance technique was used to investigate the material's performance characteristics, and the impact of cutting parameters on the work piece was analyzed using the Design Expert-V12 software. Cutting speed is the most crucial determining factor compared to other factors. The Genetic Algorithm is trained and tested in MATLAB to evaluate the best possible solutions. The genetic Algorithm recommends the most outstanding lowest predicted value of 1.2204 mm. The confirmatory analysis shows the experimental values, and their error percentage is within ±2%; these shows indicated predicted values are very close to the Genetic Algorithm results. The conclusions were in good agreement with the experimental machining time values.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47536179","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}

{"title":"Effect of Agricultural Mechanization on Production and Farmers Economy in Nigeria: A Case Study of Lagos State","authors":"Kehinde Oladoke Olatunji, O. Ogunkunle, Oladunni Adeleke Adisa, Adewumi Taiwo","doi":"10.4028/p-414rk3","DOIUrl":"https://doi.org/10.4028/p-414rk3","url":null,"abstract":"Agricultural mechanization is an essential factor influencing agricultural output and the profitability of farming activities. The influence of agricultural mechanization on agricultural production in Lagos State, where the majority of the farmers use modern technologies for their farming operations, was investigated. The investigative research approach method was employed to retrieve information from farmers through a structured questionnaire. A five rating scale questionnaire was utilized for the respondents to show their level of agreement or disagreement. The percentage was used to analyze the respondents' bio-data. At the same time, the mean was employed to answer the research questions. The null hypotheses were tested using Chi-square statistics at 0.05 significant levels. The results revealed that agricultural mechanization increased the cultivated land, crop yields, and farmers’ income with cumulative means of 2.34, 1.07, and 1.44, respectively. Socioeconomic characteristics, available technology, and government policies influenced agricultural mechanization with cumulative means of 1.93, 1.24, and 1.79, respectively. The entire six hypotheses were rejected based on the results of the Chi-square statistics with the calculated X2 values of 8,989.09, 473.59, 3,977.42, 2,192.63, 226.07 and, 1,878.05; and critical X2 values of 46.19, 46.19, 36.42, 31.41, 21.03, and 31.41, for the significant effect on the size of land cultivated, crop yield, farmer’s income, socioeconomic characteristics, available technology, and government policies respectively. The study showed that agricultural mechanization had a significant influence on crop production and farmers’ income. Therefore, there is a need to improve the available technologies and formulate and implement policies to make agricultural mechanization accessible and sustainable.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45564016","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}

{"title":"Characterization and Mechanical Property Measurements by Instrumented Indentation Testing of Niger Delta Oil Shale Cuttings","authors":"I. E. Kalu, Ericmoore Jossou, E. K. Arthur, S. Ja'afaru, E. Ishidi","doi":"10.4028/p-2m9z7g","DOIUrl":"https://doi.org/10.4028/p-2m9z7g","url":null,"abstract":"Oil shales have unstable mechanical and chemical properties, which makes their extraction for characterization and conventional mechanical testing uneasy and complex. Most often, mechanical property measurements are usually taken from core samples that are costly to extract and test using conventional testing methods. This paper presents a focused study carried out on oil shale cuttings obtained from the sidewalls of two different wellbore depths in the Niger Delta area of Nigeria. Using the X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM) characterization techniques, the morphology of these shales was studied. The results obtained clearly showed the composition, bonding and variations in the morphology of the studied shale samples. Furthermore, the heterogeneity associated with these shales across varied depths were revealed. An efficient and less expensive technique compared to conventional testing methods, instrumented indentation testing (IIT) was carried out to obtain essential mechanical parameters of the shale specimen. These properties are important parameters in determining the hydrocarbon storage space of shale formations, wellbore stability, and optimization of hydraulic fracturing which is necessary for efficient drilling operations.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45997146","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}