M. Bellahkim, Y. Benbouras, A. Maziri, E. Mallil, J. Echaabi
In this work, an experimental test series was carried out in order to evaluate the influence of the geometry of the specimen and stacking sequence on macroscopic behavior and the failure modes. A CFRP prepreg unidirectional was used to perform the tested specimens according to ASTM D790 standard. Five main lay-up configurations have been analyzed: [0]12, [±30]3s, [±45]3s, [±80]3s, and [0/90]3s subjected to flexural loading. The macroscopic behavior was followed by an MTS machine equipped with a bending fixture. A digital microscope is used to follow the microscopic failure modes during loading. These laminates exhibit a more complex behavior due to coupling effects and the combination of different failure modes. However, the most predominant damage observed is delamination accompanied with matrix cracking. Furthermore, the present work has shown a linear behavior of [0]12, [±80]3s, [0/90]3s, and a distinctive behavior of [±45]3s and [±30]3s laminate under flexural loading due to its pseudo ductile behavior.
{"title":"The Effect of the Geometrical Parameter and Stacking Sequence on Damage Behavior of Unidirectional Carbon / Epoxy Laminate","authors":"M. Bellahkim, Y. Benbouras, A. Maziri, E. Mallil, J. Echaabi","doi":"10.4028/p-aou909","DOIUrl":"https://doi.org/10.4028/p-aou909","url":null,"abstract":"In this work, an experimental test series was carried out in order to evaluate the influence of the geometry of the specimen and stacking sequence on macroscopic behavior and the failure modes. A CFRP prepreg unidirectional was used to perform the tested specimens according to ASTM D790 standard. Five main lay-up configurations have been analyzed: [0]12, [±30]3s, [±45]3s, [±80]3s, and [0/90]3s subjected to flexural loading. The macroscopic behavior was followed by an MTS machine equipped with a bending fixture. A digital microscope is used to follow the microscopic failure modes during loading. These laminates exhibit a more complex behavior due to coupling effects and the combination of different failure modes. However, the most predominant damage observed is delamination accompanied with matrix cracking. Furthermore, the present work has shown a linear behavior of [0]12, [±80]3s, [0/90]3s, and a distinctive behavior of [±45]3s and [±30]3s laminate under flexural loading due to its pseudo ductile behavior.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":"64 1","pages":"1 - 16"},"PeriodicalIF":0.7,"publicationDate":"2023-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46909612","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":"International Journal of Engineering Research in Africa Vol. 64","authors":"A. O. Ibhadode","doi":"10.4028/b-o6prky","DOIUrl":"https://doi.org/10.4028/b-o6prky","url":null,"abstract":"","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":"70 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139369420","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}
Textile products remain one of the basic products the human being cannot do without. Textile manufacturing industry is an important source point of waste water as the production of textiles requires large amount of water and over 90% of the water is discharged as waste. Due to the fact that textile products are produced in varieties of colours and patterns, use of dyes and other chemicals are usually unavoidable. consequently, effluents from the manufacturing process contain a quite number of organic and inorganic chemical compounds that have been found to have hazardous impacts on the environment. Coagulation and adsorption processes are important parts conventional waste water treatment methods. The cost of acquiring chemical coagulants and activated adsorbent has triggered research towards low cost alternatives with eco-friendly properties. In this paper, the use of natural coagulants and adsorbents for treatment of textile wastewater is looked into to cover various types of the natural materials employed for the abatement of various pollutants from the industrial effluent. The principle of adsorption and coagulations, methods used in the preparation of the natural coagulants and adsorbents and their application to real textile wastewater-this covers the review of reported works in the recent decade and the latest trend in the treatment textile waste water in such a way that environmental protection and human health are prioritized as textile waste water is known for its toxic constituents. In addition, the survey reveals the research gap in the area of application of nature based materials to industrial textile waste water which may be of importance for intending researchers in natural coagulation and adsorption.
{"title":"Use of Nature Based Materials for Textile Wastewater Treatment - A Review","authors":"S. Giwa","doi":"10.4028/p-6ope95","DOIUrl":"https://doi.org/10.4028/p-6ope95","url":null,"abstract":"Textile products remain one of the basic products the human being cannot do without. Textile manufacturing industry is an important source point of waste water as the production of textiles requires large amount of water and over 90% of the water is discharged as waste. Due to the fact that textile products are produced in varieties of colours and patterns, use of dyes and other chemicals are usually unavoidable. consequently, effluents from the manufacturing process contain a quite number of organic and inorganic chemical compounds that have been found to have hazardous impacts on the environment. Coagulation and adsorption processes are important parts conventional waste water treatment methods. The cost of acquiring chemical coagulants and activated adsorbent has triggered research towards low cost alternatives with eco-friendly properties. In this paper, the use of natural coagulants and adsorbents for treatment of textile wastewater is looked into to cover various types of the natural materials employed for the abatement of various pollutants from the industrial effluent. The principle of adsorption and coagulations, methods used in the preparation of the natural coagulants and adsorbents and their application to real textile wastewater-this covers the review of reported works in the recent decade and the latest trend in the treatment textile waste water in such a way that environmental protection and human health are prioritized as textile waste water is known for its toxic constituents. In addition, the survey reveals the research gap in the area of application of nature based materials to industrial textile waste water which may be of importance for intending researchers in natural coagulation and adsorption.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":"63 1","pages":"45 - 65"},"PeriodicalIF":0.7,"publicationDate":"2023-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41778859","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}
Solomon Workeneh Jima, Emiru Yidnekachew Melesse, Assefa Taye Endale
Currently, rapid development, increasing world population, and industrialization such as electroplating sectors have caused an increase in wastewater, heavy metals, and toxic metals in the environment that directly and indirectly affect human beings and other living things. This study compared the efficiency of electro-flotation and electrocoagulation wastewater treatment methods to treat effluents discharged from electroplating industries based on removal efficiency, energy consumption, electrode consumption, and environmental aspects. Electro-flotation uses an electric current to generate hydrogen and oxygen bubbles, which allow contaminants to flow to the top of the treatment unit. However, the electrocoagulation process involves the use of direct current to accelerate the oxidation of the metal sacrificial anode and to generate positively charged ions that act as destabilizing agents for the emulsion. The electroplating wastewater sample solution (500ml) containing heavy metal ions (Zinc, Chromium, Nickel, Cadmium, and Copper) with a 50g/l metal ion concentration of each and a pH range of 7-10, were investigated using the two methods. Accordingly, the metal ions' degree of removal, energy consumption for the treatments, and electrode consumption 95-99%, 0.25-3.0 kWh/m3, and 2.0 kg/m3 respectively, were obtained using the elector-flotation. Whereas, 90–95% of metal ions' degree of removal, 1.0-5.0 kWh/m3 of energy consumption, and 10kg/m3 of electrode consumption, were obtained via the elector coagulation. The Fe-Fe electrode combination had the highest removal efficiencies of the heavy metal ions of Fe-Al, Al-Fe, and Al-Al combinations. Additionally, the effects of pH, time, and direct current on the removal efficiency of metal ions were investigated.
{"title":"Comparison of the Removal Efficiencies for Electro-Flotation and Electrocoagulation Wastewater Treatment Methods to Treat Effluents Discharged from Electroplating Industries","authors":"Solomon Workeneh Jima, Emiru Yidnekachew Melesse, Assefa Taye Endale","doi":"10.4028/p-8352ep","DOIUrl":"https://doi.org/10.4028/p-8352ep","url":null,"abstract":"Currently, rapid development, increasing world population, and industrialization such as electroplating sectors have caused an increase in wastewater, heavy metals, and toxic metals in the environment that directly and indirectly affect human beings and other living things. This study compared the efficiency of electro-flotation and electrocoagulation wastewater treatment methods to treat effluents discharged from electroplating industries based on removal efficiency, energy consumption, electrode consumption, and environmental aspects. Electro-flotation uses an electric current to generate hydrogen and oxygen bubbles, which allow contaminants to flow to the top of the treatment unit. However, the electrocoagulation process involves the use of direct current to accelerate the oxidation of the metal sacrificial anode and to generate positively charged ions that act as destabilizing agents for the emulsion. The electroplating wastewater sample solution (500ml) containing heavy metal ions (Zinc, Chromium, Nickel, Cadmium, and Copper) with a 50g/l metal ion concentration of each and a pH range of 7-10, were investigated using the two methods. Accordingly, the metal ions' degree of removal, energy consumption for the treatments, and electrode consumption 95-99%, 0.25-3.0 kWh/m3, and 2.0 kg/m3 respectively, were obtained using the elector-flotation. Whereas, 90–95% of metal ions' degree of removal, 1.0-5.0 kWh/m3 of energy consumption, and 10kg/m3 of electrode consumption, were obtained via the elector coagulation. The Fe-Fe electrode combination had the highest removal efficiencies of the heavy metal ions of Fe-Al, Al-Fe, and Al-Al combinations. Additionally, the effects of pH, time, and direct current on the removal efficiency of metal ions were investigated.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":"63 1","pages":"67 - 82"},"PeriodicalIF":0.7,"publicationDate":"2023-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45715653","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}
A. A. Abba Ari, Asside Christian Djedouboum, A. Njoya, Hama Aziz, A. Guéroui, Alidou Mohamadou, Ousmane Thiaré, Nabila Labraoui
In recent years, tremendous advances in communication technologies coupled with the advent of the Internet of Things (IoT) have led to the emergence of the Big Data phenomenon. Big Data is one of the big IT challenges of the current decade. The amount of data produced is constantly increasing and makes it more and more difficult to process. Managing these masses of data requires the use of new data management systems with efficient access methods. Considered as one of the main sources of Big Data, wireless sensors used in networks offer a credible solution to the problem of Big Data management, especially its collection. Several solutions for Big Data collection based on large-scale wireless sensor networks (LS-WSN) are proposed, taking into account the nature of the applications. The hierarchical architecture is the one used for the deployment of these applications. In such an architecture, relay sensors play an important role in finding the balance of the network and maximizing its lifetime. In most LS-WSN applications, once deployed, the LS-WSN does not provide a mechanism to evaluate and improve the positions of the initially deployed relay sensors. This paper proposes, based on the growth model of physarum polycephalum and its ability to prune unnecessary links and retain only those deemed useful for food routing, a mechanism for evaluating and optimizing relay sensors in LS-WSNs. Simulation results indicate that the proposed approach significantly improves the network lifetime compared to the initial deployment and that can be a useful approach for LS-WSNs dedicated to Big Data collection. The effectiveness of the proposed technique is demonstrated by experimental results in terms of connectivity and network lifetime.
{"title":"Optimizing Relay Sensors in Large-Scale Wireless Sensor Networks: A Biologically Inspired Approach","authors":"A. A. Abba Ari, Asside Christian Djedouboum, A. Njoya, Hama Aziz, A. Guéroui, Alidou Mohamadou, Ousmane Thiaré, Nabila Labraoui","doi":"10.4028/p-b75r05","DOIUrl":"https://doi.org/10.4028/p-b75r05","url":null,"abstract":"In recent years, tremendous advances in communication technologies coupled with the advent of the Internet of Things (IoT) have led to the emergence of the Big Data phenomenon. Big Data is one of the big IT challenges of the current decade. The amount of data produced is constantly increasing and makes it more and more difficult to process. Managing these masses of data requires the use of new data management systems with efficient access methods. Considered as one of the main sources of Big Data, wireless sensors used in networks offer a credible solution to the problem of Big Data management, especially its collection. Several solutions for Big Data collection based on large-scale wireless sensor networks (LS-WSN) are proposed, taking into account the nature of the applications. The hierarchical architecture is the one used for the deployment of these applications. In such an architecture, relay sensors play an important role in finding the balance of the network and maximizing its lifetime. In most LS-WSN applications, once deployed, the LS-WSN does not provide a mechanism to evaluate and improve the positions of the initially deployed relay sensors. This paper proposes, based on the growth model of physarum polycephalum and its ability to prune unnecessary links and retain only those deemed useful for food routing, a mechanism for evaluating and optimizing relay sensors in LS-WSNs. Simulation results indicate that the proposed approach significantly improves the network lifetime compared to the initial deployment and that can be a useful approach for LS-WSNs dedicated to Big Data collection. The effectiveness of the proposed technique is demonstrated by experimental results in terms of connectivity and network lifetime.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":"63 1","pages":"119 - 135"},"PeriodicalIF":0.7,"publicationDate":"2023-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47537281","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}
In this study, the Jaya optimization algorithm is used to address the micro-grid energy management optimization problem using a hybrid PV-wind-microturbine-storage energy system. The main goals of this study are to reduce environmental pollution, increase microturbine operating efficiency, and minimize the cost of power generated. The overall objective of the proposed optimization method employed in the PV-WECS system is to run the PV-WECS systems at full capacity while running the microturbine when the PV-WECS systems are unable to produce all of the required power. The amount of emissions and costs of generated energy are reduced when BESS is used in the microgrid system. Furthermore, it is observed from the results that there is about 61.39% cost saving in the micro-grid operational costs and 38% carbon emissions reductions using the proposed optimization algorithm compared to the other metaheuristic algorithms used in this study. To demonstrate the appropriateness and supremacy of the proposed algorithm over the various optimization techniques for energy management of the proposed micro-grid systems, simulation results from the proposed algorithm are compared with those from other population-based metaheuristic algorithms, such as Particle Swarm Optimization (PSO), Differential Evolution (DE), Teaching Learning Based Optimization (TLBO), and Genetic Algorithms (GA). It is clear that the proposed algorithm outperforms and produces better results than the existing metaheuristic optimization techniques. More importantly, it illustrates the viability and efficacy of the proposed JAYA optimization approach in addressing the issue of energy management for large-scale power systems.
{"title":"JAYA Algorithm-Based Energy Management for a Grid-Connected Micro-Grid with PV-Wind-Microturbine-Storage Energy System","authors":"P. Gbadega, Yanping Sun","doi":"10.4028/p-du1983","DOIUrl":"https://doi.org/10.4028/p-du1983","url":null,"abstract":"In this study, the Jaya optimization algorithm is used to address the micro-grid energy management optimization problem using a hybrid PV-wind-microturbine-storage energy system. The main goals of this study are to reduce environmental pollution, increase microturbine operating efficiency, and minimize the cost of power generated. The overall objective of the proposed optimization method employed in the PV-WECS system is to run the PV-WECS systems at full capacity while running the microturbine when the PV-WECS systems are unable to produce all of the required power. The amount of emissions and costs of generated energy are reduced when BESS is used in the microgrid system. Furthermore, it is observed from the results that there is about 61.39% cost saving in the micro-grid operational costs and 38% carbon emissions reductions using the proposed optimization algorithm compared to the other metaheuristic algorithms used in this study. To demonstrate the appropriateness and supremacy of the proposed algorithm over the various optimization techniques for energy management of the proposed micro-grid systems, simulation results from the proposed algorithm are compared with those from other population-based metaheuristic algorithms, such as Particle Swarm Optimization (PSO), Differential Evolution (DE), Teaching Learning Based Optimization (TLBO), and Genetic Algorithms (GA). It is clear that the proposed algorithm outperforms and produces better results than the existing metaheuristic optimization techniques. More importantly, it illustrates the viability and efficacy of the proposed JAYA optimization approach in addressing the issue of energy management for large-scale power systems.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":"63 1","pages":"159 - 184"},"PeriodicalIF":0.7,"publicationDate":"2023-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46598497","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}
R. Hameed, Muhammad Musa Gul, M. Tahir, Shaban Shahzad, Osama Jamil, M. Awais, Zeeshan Asghar
In developing countries, the management of waste continues to be a major challenge, especially in urban areas. One of the major concerns for today’s world is the management of plastic and construction and demolition (C&D) wastes which are increasing with urbanization and population growth. This study aims to explore the possibility of the use of plastic waste as a binder and recycled aggregates obtained from C&D waste to produce concrete paving blocks. The mechanical investigation was carried out to find the optimum content of plastic waste to prepare the plastic concrete. Three different concrete mixes were prepared with plastic contents of 30%, 40%, and 50% by the weight of aggregate. To evaluate the mechanical properties of plastic concrete, compression, flexural, and ultrasonic pulse velocity (UPV) tests were performed on the prepared samples. Cubical specimens of 36 x 40 x 40 mm for compression tests and prismatic specimens of 36 x 40 x 120 mm for flexural tests were cut using a saw from the paving blocks of size 36 x 137 x 290 mm. The results indicated that the strength of plastic concrete increased with the increase in plastic content. The maximum compressive and flexural strength was achieved at 50% plastic content, which was 40.52 MPa and 10.13 MPa, respectively. The compressive and flexural strengths of plastic concrete were compared with the minimum strength requirement specified by various standards specification such as American, Canadian, and Chinese. It was found that plastic concrete with 50% content of plastic waste meets the minimum criteria of mechanical strengths specified in these standards. Presently, many countries of the African continent are facing severe problems of plastic waste. As per the findings of this study, the use of waste plastics in molten form as the only binder in the development of concrete paving blocks could offer a solution for such countries to beneficially manage the plastic waste.
在发展中国家，废物管理仍然是一项重大挑战，特别是在城市地区。当今世界的主要问题之一是塑料和建筑拆除(C&D)废物的管理，这些废物随着城市化和人口增长而增加。本研究旨在探讨利用塑料废物作为粘结剂和从土木工程废物中获得的再生骨料生产混凝土铺路砖的可能性。通过力学试验，找出制备塑性混凝土的最佳掺量。配制了三种不同的混凝土混合料，按骨料重量计塑料含量分别为30%、40%和50%。为了评估塑性混凝土的力学性能，对制备的样品进行了压缩、弯曲和超声脉冲速度(UPV)测试。使用锯从尺寸为36 x 137 x 290 mm的铺装块上切割出用于压缩试验的36 x 40 x 40 mm的立方体试件和用于弯曲试验的36 x 40 x 120 mm的棱柱形试件。结果表明，塑性混凝土的强度随塑性掺量的增加而增大。当含塑量为50%时，其抗压强度和抗折强度分别为40.52 MPa和10.13 MPa。将塑性混凝土的抗压和抗弯强度与美国、加拿大和中国等不同标准规范规定的最低强度要求进行了比较。研究发现，塑料废料掺量为50%的塑性混凝土达到了这些标准规定的机械强度的最低标准。目前，非洲大陆的许多国家都面临着严重的塑料垃圾问题。根据这项研究的结果，在混凝土铺路块的开发中，使用熔融形式的废塑料作为唯一的粘合剂，可以为这些国家提供有益管理塑料废物的解决方案。
{"title":"Mechanical Properties of Plastic Concrete Made Using Recycled Aggregates for Paving Blocks","authors":"R. Hameed, Muhammad Musa Gul, M. Tahir, Shaban Shahzad, Osama Jamil, M. Awais, Zeeshan Asghar","doi":"10.4028/p-hmjs0o","DOIUrl":"https://doi.org/10.4028/p-hmjs0o","url":null,"abstract":"In developing countries, the management of waste continues to be a major challenge, especially in urban areas. One of the major concerns for today’s world is the management of plastic and construction and demolition (C&D) wastes which are increasing with urbanization and population growth. This study aims to explore the possibility of the use of plastic waste as a binder and recycled aggregates obtained from C&D waste to produce concrete paving blocks. The mechanical investigation was carried out to find the optimum content of plastic waste to prepare the plastic concrete. Three different concrete mixes were prepared with plastic contents of 30%, 40%, and 50% by the weight of aggregate. To evaluate the mechanical properties of plastic concrete, compression, flexural, and ultrasonic pulse velocity (UPV) tests were performed on the prepared samples. Cubical specimens of 36 x 40 x 40 mm for compression tests and prismatic specimens of 36 x 40 x 120 mm for flexural tests were cut using a saw from the paving blocks of size 36 x 137 x 290 mm. The results indicated that the strength of plastic concrete increased with the increase in plastic content. The maximum compressive and flexural strength was achieved at 50% plastic content, which was 40.52 MPa and 10.13 MPa, respectively. The compressive and flexural strengths of plastic concrete were compared with the minimum strength requirement specified by various standards specification such as American, Canadian, and Chinese. It was found that plastic concrete with 50% content of plastic waste meets the minimum criteria of mechanical strengths specified in these standards. Presently, many countries of the African continent are facing severe problems of plastic waste. As per the findings of this study, the use of waste plastics in molten form as the only binder in the development of concrete paving blocks could offer a solution for such countries to beneficially manage the plastic waste.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":"63 1","pages":"13 - 31"},"PeriodicalIF":0.7,"publicationDate":"2023-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45875056","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}
In this paper, a microstrip line-fed rectangular-shaped ultra-wideband (UWB) antenna offering triple-band notch characteristics is proposed. The notching was done primarily to provide rejection for Wi-Max (3.3-3.7 GHz), WLAN2 (5.15-5.825 GHz), and ITU (8.025-8.4 GHz) through the combination of slots and a modified electromagnetic band gap (M-EBG). The antenna was simulated using HFSS and CST modelling tools. The antenna was able to notch three frequencies from narrow band communication systems (Wi-Max, WLAN2, and ITU), causing interference within the UWB band. The gain of the system over the operating frequency, the current distributions, and the impedance covered were studied to assess the effectiveness of the antenna. The proposed antenna is simple and compact, with a total antenna size of 19 mm by 24 mm and a wide bandwidth (3.2 to 12.5 GHz). Satisfactory results have been obtained when its performance was analyzed. A stable radiation characteristic is observed with a radiation efficiency of 94% when operating at a UWB resonant frequency of 6.85 GHz with a total gain between -10 dB and 5 dB within the range of the frequency band of 3.2 to 12.3 GHz.
{"title":"Development of a Triple Band Notched UWB Antenna","authors":"G. Fadehan, Y. Olasoji, K. Adedeji","doi":"10.4028/p-525842","DOIUrl":"https://doi.org/10.4028/p-525842","url":null,"abstract":"In this paper, a microstrip line-fed rectangular-shaped ultra-wideband (UWB) antenna offering triple-band notch characteristics is proposed. The notching was done primarily to provide rejection for Wi-Max (3.3-3.7 GHz), WLAN2 (5.15-5.825 GHz), and ITU (8.025-8.4 GHz) through the combination of slots and a modified electromagnetic band gap (M-EBG). The antenna was simulated using HFSS and CST modelling tools. The antenna was able to notch three frequencies from narrow band communication systems (Wi-Max, WLAN2, and ITU), causing interference within the UWB band. The gain of the system over the operating frequency, the current distributions, and the impedance covered were studied to assess the effectiveness of the antenna. The proposed antenna is simple and compact, with a total antenna size of 19 mm by 24 mm and a wide bandwidth (3.2 to 12.5 GHz). Satisfactory results have been obtained when its performance was analyzed. A stable radiation characteristic is observed with a radiation efficiency of 94% when operating at a UWB resonant frequency of 6.85 GHz with a total gain between -10 dB and 5 dB within the range of the frequency band of 3.2 to 12.3 GHz.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":"63 1","pages":"97 - 118"},"PeriodicalIF":0.7,"publicationDate":"2023-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48955430","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}
T. Manssouri, I. Manssouri, A. El Hmaidi, H. Sahbi, Othmane Noureddine
Due to its cruciality, water requires a high care to its physicochemical and microbiological properties to ensure the quality of several utilizations. The particles it carries are likely to be ingested, breathed, or come into contact with the skin. For the classification of the quality of surface water in the Moulouya River (NE, Morocco), this study presents many unsupervised classification methods. The overall quality of surface water in the Moulouya River in northeast Morocco was assessed using nine physicochemical parameters (pH, T°C, EC, O2-diss, NH4+, NO3-, SO42-, PO43-, and biological oxygen demand after 5 days (BOD5)) from March to August 2014. Over a 600-kilometer stretch, twenty-two sites were examined, from the river's source in the High Atlas to its mouth in the Mediterranean. During the first stage, three quality classes (excellent, good and poor) were defined by the calculation of the water quality index (WQI) and water quality evaluation system (QES-Water). In the second stage, the K-means algorithm, the fuzzy C-means algorithm and the self-organizing maps (SOM) of Kohonen were applied to the nine physicochemical parameters used as input variables for the model. The classification method used is capable of projecting high-dimensional data into a lower dimension, typically 2D. This nonlinear projection can be useful in classes’ analysis and their discovery. In terms of performance, the SOM classification showed very close results compared to the K-means and the fuzzy C-means algorithms, with only an insignificant difference across the three models, with SOM maps having a slight advantage.
{"title":"Unsupervised Classification of Water Quality Using Artificial Intelligence: The Case of the Moulouya Wadi's Surface Waters (NE, Morocco)","authors":"T. Manssouri, I. Manssouri, A. El Hmaidi, H. Sahbi, Othmane Noureddine","doi":"10.4028/p-6lm8z8","DOIUrl":"https://doi.org/10.4028/p-6lm8z8","url":null,"abstract":"Due to its cruciality, water requires a high care to its physicochemical and microbiological properties to ensure the quality of several utilizations. The particles it carries are likely to be ingested, breathed, or come into contact with the skin. For the classification of the quality of surface water in the Moulouya River (NE, Morocco), this study presents many unsupervised classification methods. The overall quality of surface water in the Moulouya River in northeast Morocco was assessed using nine physicochemical parameters (pH, T°C, EC, O2-diss, NH4+, NO3-, SO42-, PO43-, and biological oxygen demand after 5 days (BOD5)) from March to August 2014. Over a 600-kilometer stretch, twenty-two sites were examined, from the river's source in the High Atlas to its mouth in the Mediterranean. During the first stage, three quality classes (excellent, good and poor) were defined by the calculation of the water quality index (WQI) and water quality evaluation system (QES-Water). In the second stage, the K-means algorithm, the fuzzy C-means algorithm and the self-organizing maps (SOM) of Kohonen were applied to the nine physicochemical parameters used as input variables for the model. The classification method used is capable of projecting high-dimensional data into a lower dimension, typically 2D. This nonlinear projection can be useful in classes’ analysis and their discovery. In terms of performance, the SOM classification showed very close results compared to the K-means and the fuzzy C-means algorithms, with only an insignificant difference across the three models, with SOM maps having a slight advantage.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":"63 1","pages":"83 - 95"},"PeriodicalIF":0.7,"publicationDate":"2023-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45176360","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}
Abdelaziz Bouras, Djedid Taloub, M. Djezzar, Z. Driss
The second part study of this paper is to numerically study the double-diffusive natural convection phenomenon inside a space annulus, situated between two horizontal confocal elliptic cylinders filled with a laminar flow, is presented. The elliptical coordinates do utilize to transform the physical domain into one rectangular. The basic equations are discretized using the finite-volume method. Using a developed code, the study covers a wide range for (103 ≤ Rat ≤105), Le = 2, N = 1, e = 0.52, 0.62, 0.72, 0.82.We have made some detailed studies covering the influence of the internal eccentricity parameter e1 on heat and mass transfer. Results do present in the form of isotherms, streamlines, and heat transfer. The local and average numbers for Sherwood and Nesselt are also displayed.Comparison with the published results showed that there is a good agreement. Keywords:double-diffusive, natural convection, elliptic cylinders, Rayleigh number, Lewis number.
{"title":"Numerical Research of Double‐Diffusive Natural Convection in Elliptical Cylinders: Influence of Internal Eccentricity","authors":"Abdelaziz Bouras, Djedid Taloub, M. Djezzar, Z. Driss","doi":"10.4028/p-v8e2q8","DOIUrl":"https://doi.org/10.4028/p-v8e2q8","url":null,"abstract":"The second part study of this paper is to numerically study the double-diffusive natural convection phenomenon inside a space annulus, situated between two horizontal confocal elliptic cylinders filled with a laminar flow, is presented. The elliptical coordinates do utilize to transform the physical domain into one rectangular. The basic equations are discretized using the finite-volume method. Using a developed code, the study covers a wide range for (103 ≤ Rat ≤105), Le = 2, N = 1, e = 0.52, 0.62, 0.72, 0.82.We have made some detailed studies covering the influence of the internal eccentricity parameter e1 on heat and mass transfer. Results do present in the form of isotherms, streamlines, and heat transfer. The local and average numbers for Sherwood and Nesselt are also displayed.Comparison with the published results showed that there is a good agreement. Keywords:double-diffusive, natural convection, elliptic cylinders, Rayleigh number, Lewis number.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":"63 1","pages":"33 - 44"},"PeriodicalIF":0.7,"publicationDate":"2023-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44205644","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：