Pub Date : 2024-05-01Epub Date: 2023-08-30DOI: 10.1177/1742271X231188659
Christopher Ekene Ilounoh, Rajuno Ernest Eteng, Yuriy Arlachov
Introduction: Undifferentiated sarcoma is considered a rare and aggressive type of soft tissue sarcoma with the lower extremity reported as the common site for soft tissue sarcomas.
Case presentation: We present a rare incidental finding of undifferentiated sarcoma during lower limb Doppler ultrasound with a presenting symptom of right thrombotic-like calf pain in a 49-year-old female.
Discussion: On ultrasound, the presented undifferentiated sarcoma appeared as a large heterogeneous, oval-shaped, soft tissue mass deeply seated in the right calf with involvement of the soleus muscle. The features on ultrasound mimicked those of a hematoma; however, the possibility of the lesion being a haematoma was promptly ruled out with the demonstration of internal vascularity on colour Doppler application. The case was then referred to a sarcoma triage multidisciplinary team for a review. Magnetic resonance imaging, computed tomography and biopsy were parts of the diagnostic workup for this case, histology confirmed the soft tissue lesion to be an undifferentiated sarcoma. Emergency above knee amputation of the right leg was performed as part of the patient's treatment.
Conclusion: This case report presents a rare incidental finding of undifferentiated sarcoma encountered during lower limb Doppler ultrasound causing thrombotic-like calf pain. Sonographers are encouraged to pay necessary attention and carefully examine any adjacent and incidental soft tissue lesion during lower limb Doppler ultrasound using compression, two-dimensional imaging and colour imaging, especially those that appear with characteristic features of malignancy; urgent referral should be made of such cases to a tertiary soft tissue sarcoma centre for further evaluation and management.
{"title":"Incidental finding of an undifferentiated sarcoma during lower limb Doppler ultrasound: A case report.","authors":"Christopher Ekene Ilounoh, Rajuno Ernest Eteng, Yuriy Arlachov","doi":"10.1177/1742271X231188659","DOIUrl":"10.1177/1742271X231188659","url":null,"abstract":"<p><strong>Introduction: </strong>Undifferentiated sarcoma is considered a rare and aggressive type of soft tissue sarcoma with the lower extremity reported as the common site for soft tissue sarcomas.</p><p><strong>Case presentation: </strong>We present a rare incidental finding of undifferentiated sarcoma during lower limb Doppler ultrasound with a presenting symptom of right thrombotic-like calf pain in a 49-year-old female.</p><p><strong>Discussion: </strong>On ultrasound, the presented undifferentiated sarcoma appeared as a large heterogeneous, oval-shaped, soft tissue mass deeply seated in the right calf with involvement of the soleus muscle. The features on ultrasound mimicked those of a hematoma; however, the possibility of the lesion being a haematoma was promptly ruled out with the demonstration of internal vascularity on colour Doppler application. The case was then referred to a sarcoma triage multidisciplinary team for a review. Magnetic resonance imaging, computed tomography and biopsy were parts of the diagnostic workup for this case, histology confirmed the soft tissue lesion to be an undifferentiated sarcoma. Emergency above knee amputation of the right leg was performed as part of the patient's treatment.</p><p><strong>Conclusion: </strong>This case report presents a rare incidental finding of undifferentiated sarcoma encountered during lower limb Doppler ultrasound causing thrombotic-like calf pain. Sonographers are encouraged to pay necessary attention and carefully examine any adjacent and incidental soft tissue lesion during lower limb Doppler ultrasound using compression, two-dimensional imaging and colour imaging, especially those that appear with characteristic features of malignancy; urgent referral should be made of such cases to a tertiary soft tissue sarcoma centre for further evaluation and management.</p>","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":"33 1","pages":"128-134"},"PeriodicalIF":4.5,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11060118/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82813616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Martins Obaseki, P. B. Alfred, P. T. Elijah, S. O. Okuma
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.
{"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":" 2","pages":"27 - 48"},"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}
Mohamed Zohair Kaab, B. Athamnia, Tarek Djedid, H. Khelaifa
Utilizing local materials and recycling waste has the potential to yield both ecological and economic advantages in the field of construction materials. In this context, the object of this work is to apply Taguchi's design of experiments on cement eco-mortar, which were designed using an L-9 orthogonal array, to optimize and model the effect of dune sand of the El Oued region, rubber aggregates, and crushed clay brick waste on the mechanical strength at 28 days. The different interactions were also investigated between the factors targeted in our study, namely: dune sand (DS) content, rubber aggregates (RA) content, and brick waste (BW) content. The results of the analysis of variation (ANOVA) as well as the mathematical models developed in this study showed that the BW factor content has a positive effect on compressive strength and a negative effect on flexural strength. In addition, the interactions between DS and BW contents and between RA and BW contents have a negative effect on the compressive strength of eco-mortar. With regard to flexural strength, the results showed that the interaction between the factors DS and RA contents has a negative effect on flexural strength, in contrast to the interaction between the RA and BW contents, which has a positive effect.
在建筑材料领域，利用当地材料和回收废物有可能产生生态和经济优势。在此背景下，本研究采用田口试验设计法对水泥生态砂浆进行试验，试验设计采用 L-9 正交阵列，以优化和模拟埃尔韦德地区沙丘砂、橡胶骨料和碎粘土砖废料对 28 天机械强度的影响。我们还研究了沙丘砂（DS）含量、橡胶集料（RA）含量和砖块废料（BW）含量这几个目标因素之间的相互作用。变异分析（ANOVA）和本研究建立的数学模型的结果表明，BW 因子含量对抗压强度有正向影响，而对抗折强度有负向影响。此外，DS 和 BW 含量之间以及 RA 和 BW 含量之间的交互作用对生态砂浆的抗压强度有负面影响。在抗折强度方面，结果表明 DS 和 RA 含量之间的交互作用对抗折强度有负面影响，而 RA 和 BW 含量之间的交互作用则有正面影响。
{"title":"Optimization of the Impact of Dune Sand, Recycled Rubber Aggregates, and Clay Brick Waste on Eco-Mortar Mechanical Strength by the Taguchi Method","authors":"Mohamed Zohair Kaab, B. Athamnia, Tarek Djedid, H. Khelaifa","doi":"10.4028/p-s0mYlB","DOIUrl":"https://doi.org/10.4028/p-s0mYlB","url":null,"abstract":"Utilizing local materials and recycling waste has the potential to yield both ecological and economic advantages in the field of construction materials. In this context, the object of this work is to apply Taguchi's design of experiments on cement eco-mortar, which were designed using an L-9 orthogonal array, to optimize and model the effect of dune sand of the El Oued region, rubber aggregates, and crushed clay brick waste on the mechanical strength at 28 days. The different interactions were also investigated between the factors targeted in our study, namely: dune sand (DS) content, rubber aggregates (RA) content, and brick waste (BW) content. The results of the analysis of variation (ANOVA) as well as the mathematical models developed in this study showed that the BW factor content has a positive effect on compressive strength and a negative effect on flexural strength. In addition, the interactions between DS and BW contents and between RA and BW contents have a negative effect on the compressive strength of eco-mortar. With regard to flexural strength, the results showed that the interaction between the factors DS and RA contents has a negative effect on flexural strength, in contrast to the interaction between the RA and BW contents, which has a positive effect.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":"138 3","pages":"67 - 78"},"PeriodicalIF":0.7,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138995393","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}
B. M. Ganou Koungang, Luc Courard, Ulrich Tatchum Defo, D. Ndapeu, E. Njeugna, Shady Attia
A novel low-cost earthen construction system integrating biosourced aggregates is proposed for houses’ erection of low-income households. This study is based on in-situ measurements on two representative test cells constructed in Douala, with a typical hot and humid climate. One of these buildings is made with a hollow cement block as a reference, and the other with biosourced earth bricks modified with Cocos nucifera and Canarium schweinfurthii aggregates. Dynamic thermal simulations of the two test cells were performed using the EnergyPlus building performance simulation program. The results are based on measuring air temperature and humidity, and the simulation leads to defining the discomfort hours and the annual energy consumption. The adaptive ASHRAE 55 thermal comfort model was used to evaluate the comfort conditions. The results show that air conditioning systems provide the best comfort systems with minimums of about 95% for plastered and unplastered wall construction systems. Biosourced compressed earth brick constructions offered the best thermal performance with comfort ranges of around 96% and 44% for air conditioning and natural ventilation, respectively. In terms of energy consumed, there was a gain of about 100 kWh over the year. Energy consumption is lower in the biosourced compressed earth brick building than in the hollowed cement block building: this one offered the lowest comfort range of about 40% in natural ventilation. The construction provisions were considered for the life cycle assessment, and two scenarios describing the origin of the cement raw materials were considered. It can be seen that cement accounts for more than 95% of the impacts for both construction systems, as well as for the scenarios of its origin. In all situations, the hollowed cement block construction presented the highest impact on the global warming potential: 66 KgCO2eq and 89 KgCO2eq, respectively, without plaster and with plaster. It can also be seen that the plastered layer had a carbon footprint (in terms of Green House Gas Emissions (GHG emissions)) of almost 40% on the overall functional unit. Canarium Schweinfurthii and Cocos Nucifera materials accounted for only 1% of the overall impact.
{"title":"Evaluating Thermal Performance and Environmental Impact of Compressed Earth Blocks with Cocos and Canarium Aggregates: A Study in Douala, Cameroon","authors":"B. M. Ganou Koungang, Luc Courard, Ulrich Tatchum Defo, D. Ndapeu, E. Njeugna, Shady Attia","doi":"10.4028/p-71UmdZ","DOIUrl":"https://doi.org/10.4028/p-71UmdZ","url":null,"abstract":"A novel low-cost earthen construction system integrating biosourced aggregates is proposed for houses’ erection of low-income households. This study is based on in-situ measurements on two representative test cells constructed in Douala, with a typical hot and humid climate. One of these buildings is made with a hollow cement block as a reference, and the other with biosourced earth bricks modified with Cocos nucifera and Canarium schweinfurthii aggregates. Dynamic thermal simulations of the two test cells were performed using the EnergyPlus building performance simulation program. The results are based on measuring air temperature and humidity, and the simulation leads to defining the discomfort hours and the annual energy consumption. The adaptive ASHRAE 55 thermal comfort model was used to evaluate the comfort conditions. The results show that air conditioning systems provide the best comfort systems with minimums of about 95% for plastered and unplastered wall construction systems. Biosourced compressed earth brick constructions offered the best thermal performance with comfort ranges of around 96% and 44% for air conditioning and natural ventilation, respectively. In terms of energy consumed, there was a gain of about 100 kWh over the year. Energy consumption is lower in the biosourced compressed earth brick building than in the hollowed cement block building: this one offered the lowest comfort range of about 40% in natural ventilation. The construction provisions were considered for the life cycle assessment, and two scenarios describing the origin of the cement raw materials were considered. It can be seen that cement accounts for more than 95% of the impacts for both construction systems, as well as for the scenarios of its origin. In all situations, the hollowed cement block construction presented the highest impact on the global warming potential: 66 KgCO2eq and 89 KgCO2eq, respectively, without plaster and with plaster. It can also be seen that the plastered layer had a carbon footprint (in terms of Green House Gas Emissions (GHG emissions)) of almost 40% on the overall functional unit. Canarium Schweinfurthii and Cocos Nucifera materials accounted for only 1% of the overall impact.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":"28 1","pages":"49 - 66"},"PeriodicalIF":0.7,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139176356","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}
Freddy Sotto Capera, Juan Gonzalo Ardila Marín, Camila Cerquera Sandoval
Technologies that take advantage of alternative sources, such as Michell-Banki turbines, can improve electric power conditions in rural or non-interconnected areas with low environmental impact, but they need to be further studied to better understand their phenomenology and ways to increase their performance. The numerical evaluation of rotors under specific operating conditions results in efficiency curves for the evaluated prototypes such that devices that take full advantage of the flow conditions of a given location are proposed. Considering the above, the main objective of this work was to design the rotor and the injector of a Michell-Banki turbine and to evaluate it numerically for the conditions of 0.24 m3/s and 18 m of head available at a point with potential energy use in the irrigation district Canal Iguá in Huila - Colombia. The design was made following OLADE recommendations, and the simulations were made utilizing computational fluid dynamics, the k- ω turbulence model was used and the torque was monitored, then the GCI and TCI were calculated to establish the numerical uncertainty of the results. Finally, the numerical curves of efficiency versus rotor speed were created. Both the design and simulation results show that the design is feasible for the operating conditions and meets the expectations of serving for the installation of a 20 kW micro-hydroelectric power plant at the site, but the design predicted an atypically high 86.3% efficiency, while the simulation reported an atypically low 51.8%, being 78% the average reported according to OLADE.
{"title":"Numerical Study of the Opening Angle Incidence in Michell-Banki Turbine’s Performance without Guide Blades","authors":"Freddy Sotto Capera, Juan Gonzalo Ardila Marín, Camila Cerquera Sandoval","doi":"10.4028/p-EO6We7","DOIUrl":"https://doi.org/10.4028/p-EO6We7","url":null,"abstract":"Technologies that take advantage of alternative sources, such as Michell-Banki turbines, can improve electric power conditions in rural or non-interconnected areas with low environmental impact, but they need to be further studied to better understand their phenomenology and ways to increase their performance. The numerical evaluation of rotors under specific operating conditions results in efficiency curves for the evaluated prototypes such that devices that take full advantage of the flow conditions of a given location are proposed. Considering the above, the main objective of this work was to design the rotor and the injector of a Michell-Banki turbine and to evaluate it numerically for the conditions of 0.24 m3/s and 18 m of head available at a point with potential energy use in the irrigation district Canal Iguá in Huila - Colombia. The design was made following OLADE recommendations, and the simulations were made utilizing computational fluid dynamics, the k- ω turbulence model was used and the torque was monitored, then the GCI and TCI were calculated to establish the numerical uncertainty of the results. Finally, the numerical curves of efficiency versus rotor speed were created. Both the design and simulation results show that the design is feasible for the operating conditions and meets the expectations of serving for the installation of a 20 kW micro-hydroelectric power plant at the site, but the design predicted an atypically high 86.3% efficiency, while the simulation reported an atypically low 51.8%, being 78% the average reported according to OLADE.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":" 11","pages":"101 - 122"},"PeriodicalIF":0.7,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138964451","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}
Younes Faouzi, Omkaltoume El Fatni, A. Maftouh, Bouchra Laarabi, A. Barhdadi
This paper presents a comprehensive study conducted as part of the Propre.ma's project, comparing data from several identical photovoltaic systems installed at multiple sites in Morocco. The project capitalizes on twenty distinct locations equipped with the same solar photovoltaic system and three varieties of solar modules (Mono-si, Poly-si, and Amorphous-si) with nearly identical rated power (2kWp) and a standardized 2 kW inverter. The main objectives are to compare the energy production of different solar photovoltaic systems over two years (2015 to 2016) and to assess the performance of PVsyst and SAM simulation software, renowned for their precision. The study reveals that Mono-si and Poly-si systems produce higher energy outputs than Amorphous-si. Moreover, PVsyst demonstrates closer alignment with real-world energy production rates across all technologies (Mono-si, Poly-si, and Amorphous-si) compared to SAM. This research represents a pioneering effort in evaluating simulation software for photovoltaic systems deployed across multiple sites, providing valuable insights for future solar energy projects and technological advancements.
{"title":"Comparative Analysis of Energy Production and Simulation Software for Photovoltaic Systems in Multiple Moroccan Sites","authors":"Younes Faouzi, Omkaltoume El Fatni, A. Maftouh, Bouchra Laarabi, A. Barhdadi","doi":"10.4028/p-j5vhDU","DOIUrl":"https://doi.org/10.4028/p-j5vhDU","url":null,"abstract":"This paper presents a comprehensive study conducted as part of the Propre.ma's project, comparing data from several identical photovoltaic systems installed at multiple sites in Morocco. The project capitalizes on twenty distinct locations equipped with the same solar photovoltaic system and three varieties of solar modules (Mono-si, Poly-si, and Amorphous-si) with nearly identical rated power (2kWp) and a standardized 2 kW inverter. The main objectives are to compare the energy production of different solar photovoltaic systems over two years (2015 to 2016) and to assess the performance of PVsyst and SAM simulation software, renowned for their precision. The study reveals that Mono-si and Poly-si systems produce higher energy outputs than Amorphous-si. Moreover, PVsyst demonstrates closer alignment with real-world energy production rates across all technologies (Mono-si, Poly-si, and Amorphous-si) compared to SAM. This research represents a pioneering effort in evaluating simulation software for photovoltaic systems deployed across multiple sites, providing valuable insights for future solar energy projects and technological advancements.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":" 42","pages":"189 - 206"},"PeriodicalIF":0.7,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138963697","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}
B. Moulai Ali, Djilali Bouha, Abdellah Kaou, El Bahri Ould Chikh, H. Meddah, Athmane Khalifa Bouha
The objective of the current work is to analyze the influence of water cooling of high density polyethylene (HDPE) sheet welding by friction stir process (FSW) on mechanical strength, based on microhardness tests. In the present work, the process using the conventional tool (C-FSW) is presented with the new procedure developed for FSW for HDPE, called water conventional friction stir welding (W-FSW). Test results for water-cooled and non-cooled welded samples were compared. HDPE sheets were initially welded by FSW process, and intensive water cooling was performed to weld after the tool exceeded the initial welding position by 30mm. The tool rotation speed of 1100 rpm and welding speed of 26 mm/min was used. The results were compared and evaluated with the hardness tests. A decrease in the hardness was observed when the sheets were treated by quenching, especially in the weld cores. It was found that the average hardness was much lower than that of untreated welded plates. Additionally, there is a region outside the core that has more or less the same stiffness value. The use of intensive quenching and conventional tooling has proven to be of great importance in improving surface finish, reducing defects, and increasing the mechanical strength of welds. The resulting recrystallization modified the hardness and thus increased the efficiency of the joint. These findings indicate the welding quality of the studied polyethylene.
{"title":"Effect of Water Cooling on the Microhardness of Friction Stir Welded High-Density Polyethylene Sheets: Experimental Study","authors":"B. Moulai Ali, Djilali Bouha, Abdellah Kaou, El Bahri Ould Chikh, H. Meddah, Athmane Khalifa Bouha","doi":"10.4028/p-QPbA1o","DOIUrl":"https://doi.org/10.4028/p-QPbA1o","url":null,"abstract":"The objective of the current work is to analyze the influence of water cooling of high density polyethylene (HDPE) sheet welding by friction stir process (FSW) on mechanical strength, based on microhardness tests. In the present work, the process using the conventional tool (C-FSW) is presented with the new procedure developed for FSW for HDPE, called water conventional friction stir welding (W-FSW). Test results for water-cooled and non-cooled welded samples were compared. HDPE sheets were initially welded by FSW process, and intensive water cooling was performed to weld after the tool exceeded the initial welding position by 30mm. The tool rotation speed of 1100 rpm and welding speed of 26 mm/min was used. The results were compared and evaluated with the hardness tests. A decrease in the hardness was observed when the sheets were treated by quenching, especially in the weld cores. It was found that the average hardness was much lower than that of untreated welded plates. Additionally, there is a region outside the core that has more or less the same stiffness value. The use of intensive quenching and conventional tooling has proven to be of great importance in improving surface finish, reducing defects, and increasing the mechanical strength of welds. The resulting recrystallization modified the hardness and thus increased the efficiency of the joint. These findings indicate the welding quality of the studied polyethylene.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":"49 2","pages":"17 - 25"},"PeriodicalIF":0.7,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139173178","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. 67","authors":"","doi":"10.4028/b-sr8gxf","DOIUrl":"https://doi.org/10.4028/b-sr8gxf","url":null,"abstract":"","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":"38 4","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139174690","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. Njoya, Alice Wangui Wachira, A. A. Abba Ari, Rockefeller Rockefeller, A. Guéroui, Christopher Thron, Sondes Khemiri Kallel, Wahabou Abdou, Emmanuel Tonye
Congestion has become a big issue in major cities throughout the world. Numerous transportation activities have been affected, and travel times have increased as a result of many travelers spending lengthy hours on the road. To overcome these challenges, the Intelligent Transportation System (ITS), which provides efficient traffic service and management, has sparked widespread attention. Collection and analysis of traffic data has been made possible by the algorithms implemented by the ITS. Huge volumes of data are produced by the vast wide range of sensors used in the Internet of Things (IoT), enabling the collection of a variety of traffic information. Development of short-term traffic speed prediction, has been made possible using deep learning models such as Long Short Term Memory (LSTM) and Bidirectional LSTM. Numerous variables, including the weather, the state of the roads, and traffic congestion, can have long-term dependencies and influence traffic speed. The bidirectional architecture of Bi-LSTMs enables them to handle long-term dependencies in sequences and efficiently capture both past and future context in a sequence, which is crucial for producing accurate forecasts of traffic speed. In this paper, the upstream and downstream flow of traffic speed on various pathways has been investigated using a traffic path planning algorithm based on Bi-LSTM models. The algorithm considers the factors affecting the flow of traffic at different seasons and time of the day and tries to predict the average speed associated to that path several timeslots ahead. The experimental results demonstrated that the Bi-LSTM model has the benefit of predicting speed for various timeslots while retaining a high level of accuracy.
{"title":"A Machine Learning Scheme for Speed Prediction in Intelligent Transportation Systems Using a Bi-LSTM Based Model","authors":"A. Njoya, Alice Wangui Wachira, A. A. Abba Ari, Rockefeller Rockefeller, A. Guéroui, Christopher Thron, Sondes Khemiri Kallel, Wahabou Abdou, Emmanuel Tonye","doi":"10.4028/p-FZ0iNi","DOIUrl":"https://doi.org/10.4028/p-FZ0iNi","url":null,"abstract":"Congestion has become a big issue in major cities throughout the world. Numerous transportation activities have been affected, and travel times have increased as a result of many travelers spending lengthy hours on the road. To overcome these challenges, the Intelligent Transportation System (ITS), which provides efficient traffic service and management, has sparked widespread attention. Collection and analysis of traffic data has been made possible by the algorithms implemented by the ITS. Huge volumes of data are produced by the vast wide range of sensors used in the Internet of Things (IoT), enabling the collection of a variety of traffic information. Development of short-term traffic speed prediction, has been made possible using deep learning models such as Long Short Term Memory (LSTM) and Bidirectional LSTM. Numerous variables, including the weather, the state of the roads, and traffic congestion, can have long-term dependencies and influence traffic speed. The bidirectional architecture of Bi-LSTMs enables them to handle long-term dependencies in sequences and efficiently capture both past and future context in a sequence, which is crucial for producing accurate forecasts of traffic speed. In this paper, the upstream and downstream flow of traffic speed on various pathways has been investigated using a traffic path planning algorithm based on Bi-LSTM models. The algorithm considers the factors affecting the flow of traffic at different seasons and time of the day and tries to predict the average speed associated to that path several timeslots ahead. The experimental results demonstrated that the Bi-LSTM model has the benefit of predicting speed for various timeslots while retaining a high level of accuracy.","PeriodicalId":45925,"journal":{"name":"International Journal of Engineering Research in Africa","volume":"19 1","pages":"207 - 233"},"PeriodicalIF":0.7,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139175865","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}
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