Pub Date : 2023-12-04DOI: 10.1080/23311916.2023.2269652
Vrunda N. Katagi, Manasa S, Raghavendra P, Sohani G. Bhat, Divyashree M S
Abstract Wide applications of conventional plastics across the world have made its production inevitable. To avoid the ecocide occurring due to conventional plastics, studies on the production and extraction of renowned biopolymers like polyhydroxyalkanoates (PHAs) are explored. PHA is a family of polyesters naturally produced by bacterial fermentation with the potential to replace conventional hydrocarbon-based polymers. The efficient utilization of industrial discard as renewable feedstocks in the production of eco-friendly products such as bioplastics has been studied. This study focuses on the production of PHA using cashew industry wastewater (CIW). Since cashew industry wastewater (CIW) is rich in phenolic compounds and other sources, this study explores the possibility of eliminating the toxic phenol compounds from the waste by the production of PHA using cashew industry wastewater as a secondary source of carbon by paving the way to eco-friendly process. In this context, PHA-producing bacterium was isolated from wastewater samples collected from cashew industries. The morphological, microscopic, and biochemical characterization revealed that the isolated strain CFM1 is Bacillus sp. The strain CFM1 that gave maximum (30%) PHA in control medium was taken up for further studies with wastewater. The concentration of sucrose in the control production media was replaced with cashew industry wastewater. Wastewater was introduced to the medium at different concentrations (10–100%). As CIW concentration was increased, the sucrose concentration was decreased in the medium accordingly. CFM1 isolates produced 34% PHA with 20% wastewater. The biopolymer produced was characterized by FTIR and NMR.
{"title":"Valorization of cashew industry wastewater as a carbon and nutrient source for the microbial growth and production of the polyhydroxyalkanoates: A potential biopolymer by Bacillus species","authors":"Vrunda N. Katagi, Manasa S, Raghavendra P, Sohani G. Bhat, Divyashree M S","doi":"10.1080/23311916.2023.2269652","DOIUrl":"https://doi.org/10.1080/23311916.2023.2269652","url":null,"abstract":"Abstract Wide applications of conventional plastics across the world have made its production inevitable. To avoid the ecocide occurring due to conventional plastics, studies on the production and extraction of renowned biopolymers like polyhydroxyalkanoates (PHAs) are explored. PHA is a family of polyesters naturally produced by bacterial fermentation with the potential to replace conventional hydrocarbon-based polymers. The efficient utilization of industrial discard as renewable feedstocks in the production of eco-friendly products such as bioplastics has been studied. This study focuses on the production of PHA using cashew industry wastewater (CIW). Since cashew industry wastewater (CIW) is rich in phenolic compounds and other sources, this study explores the possibility of eliminating the toxic phenol compounds from the waste by the production of PHA using cashew industry wastewater as a secondary source of carbon by paving the way to eco-friendly process. In this context, PHA-producing bacterium was isolated from wastewater samples collected from cashew industries. The morphological, microscopic, and biochemical characterization revealed that the isolated strain CFM1 is Bacillus sp. The strain CFM1 that gave maximum (30%) PHA in control medium was taken up for further studies with wastewater. The concentration of sucrose in the control production media was replaced with cashew industry wastewater. Wastewater was introduced to the medium at different concentrations (10–100%). As CIW concentration was increased, the sucrose concentration was decreased in the medium accordingly. CFM1 isolates produced 34% PHA with 20% wastewater. The biopolymer produced was characterized by FTIR and NMR.","PeriodicalId":10464,"journal":{"name":"Cogent Engineering","volume":"19 6","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138603363","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}
Pub Date : 2023-11-30DOI: 10.1080/23311916.2023.2278259
S. Anandarao, Sweetlin Hemalatha Chellasamy
Abstract Density peak clustering (DPC) has shown promising results for many complex problems when compared with other existing clustering techniques. Inspite of many advantages, DPC suffers with lack of cluster centroids and cut-off distance identification. Cut-off distance is the prominent parameter used in the calculation of local density. The improper choice of cut-off distance leads to improper cluster results. Currently, the cut-off distance is selected using decision graph or delta density or knee point detection or silhouette score or kernel functions. The main problem with the above functions for selecting the cut-off distance in DPC is that they often rely on heuristic or visually subjective criteria, making the choice of the optimal cut-off distance challenging and potentially sensitive to data characteristics. By leveraging metaheuristic optimisation algorithms, the process of selecting the cut-off distance becomes less subjective and data-driven, potentially leading to improved clustering results in DPC. This motivated us to work on the choice of cut-off distance by the usage of remora optimisation algorithm (ROA). The cluster results are improved by the usage of remora in selection of reliable cut-off distance (${d_c})$dc). The effectiveness of the updated DPC with ROA is evaluated by applying on the eight datasets and compared with K-means, traditional DPC, DPC merged with other optimisation results. The three parameters used here to check the quality of the cluster are homogeneity, completeness and silhouette analysis. ROA is new and built on the inspiration of remora which moves from one place to another using the sea fishes like shark, whale, sword fish, etc. It is clear from the results that DPC with ROA has produced the better homogeneity value of 0.807, completeness of 0.699 and silhouette analysis of 0.79 than the other clustering algorithms.
{"title":"Nature inspired-based remora optimisation algorithm for enhancement of density peak clustering","authors":"S. Anandarao, Sweetlin Hemalatha Chellasamy","doi":"10.1080/23311916.2023.2278259","DOIUrl":"https://doi.org/10.1080/23311916.2023.2278259","url":null,"abstract":"Abstract Density peak clustering (DPC) has shown promising results for many complex problems when compared with other existing clustering techniques. Inspite of many advantages, DPC suffers with lack of cluster centroids and cut-off distance identification. Cut-off distance is the prominent parameter used in the calculation of local density. The improper choice of cut-off distance leads to improper cluster results. Currently, the cut-off distance is selected using decision graph or delta density or knee point detection or silhouette score or kernel functions. The main problem with the above functions for selecting the cut-off distance in DPC is that they often rely on heuristic or visually subjective criteria, making the choice of the optimal cut-off distance challenging and potentially sensitive to data characteristics. By leveraging metaheuristic optimisation algorithms, the process of selecting the cut-off distance becomes less subjective and data-driven, potentially leading to improved clustering results in DPC. This motivated us to work on the choice of cut-off distance by the usage of remora optimisation algorithm (ROA). The cluster results are improved by the usage of remora in selection of reliable cut-off distance (${d_c})$dc). The effectiveness of the updated DPC with ROA is evaluated by applying on the eight datasets and compared with K-means, traditional DPC, DPC merged with other optimisation results. The three parameters used here to check the quality of the cluster are homogeneity, completeness and silhouette analysis. ROA is new and built on the inspiration of remora which moves from one place to another using the sea fishes like shark, whale, sword fish, etc. It is clear from the results that DPC with ROA has produced the better homogeneity value of 0.807, completeness of 0.699 and silhouette analysis of 0.79 than the other clustering algorithms.","PeriodicalId":10464,"journal":{"name":"Cogent Engineering","volume":"56 7","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139206249","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}
Pub Date : 2023-11-30DOI: 10.1080/23311916.2023.2287296
M. Kalayarasan, Jonathan Reginald, J. Corda, P. Dhanbal, Prathik S. Jain, Laxmikant G. Keni, K. Chethan, Zhongmin Jin
Abstract Hip implants are available in various shapes and sizes. This study aims to select the better hip implant stem design and the optimal material that can be used for the implant. For all the material combinations, radial clearance of 0, 0.1, 0.2, and 0.3 had been given between each of the junctions. Analytical calculation using Hertz contact stress formulation to find the contact pressure has been employed for a load of 2300N, which goes hand in hand with the Finite element method (FEM). The results showed that the optimal combination consists of a CoCr alloy stem, femoral head, and cup material, paired with a UHMWPE liner, for the most effective performance. This study thoroughly evaluates various hip implant options and offers important insights into their effectiveness. The results of this research will assist in choosing the most appropriate hip implant design and material, leading to better patient outcomes and advancements in medical technology for the betterment of mankind.
{"title":"Computational investigation of various stem designs with different radial clearances in total hip arthroplasty","authors":"M. Kalayarasan, Jonathan Reginald, J. Corda, P. Dhanbal, Prathik S. Jain, Laxmikant G. Keni, K. Chethan, Zhongmin Jin","doi":"10.1080/23311916.2023.2287296","DOIUrl":"https://doi.org/10.1080/23311916.2023.2287296","url":null,"abstract":"Abstract Hip implants are available in various shapes and sizes. This study aims to select the better hip implant stem design and the optimal material that can be used for the implant. For all the material combinations, radial clearance of 0, 0.1, 0.2, and 0.3 had been given between each of the junctions. Analytical calculation using Hertz contact stress formulation to find the contact pressure has been employed for a load of 2300N, which goes hand in hand with the Finite element method (FEM). The results showed that the optimal combination consists of a CoCr alloy stem, femoral head, and cup material, paired with a UHMWPE liner, for the most effective performance. This study thoroughly evaluates various hip implant options and offers important insights into their effectiveness. The results of this research will assist in choosing the most appropriate hip implant design and material, leading to better patient outcomes and advancements in medical technology for the betterment of mankind.","PeriodicalId":10464,"journal":{"name":"Cogent Engineering","volume":"119 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139198844","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}
Pub Date : 2023-11-29DOI: 10.1080/23311916.2023.2283293
Tale Geddafa
Abstract The Ethiopian Investment Commission was established to formulate suitable investment policy with good investment climate that enables investors to operate in a more macroeconomic friendly environment. Despite all efforts, domestic private investment in Ethiopia is still in its early stages. Therefore, this study aimed to investigate the trends and determinants of domestic private investment in Ethiopia using a time series data over the period 1992–2022. To meet its goal, the study employed an Autoregressive Distributed Lag (ARDL) bounds testing approach through E-views version 12. The findings show that domestic private investment was negatively and significantly affected by the inflation rate, public investment, and real effective exchange rate over a period of both the short- and long-run. While domestic credit to the private sector, foreign direct investment, real GDP and trade openness were found to have positive and significant effect on domestic private investment in long run. Unemployment rate was found to have positive and significant effect in short run but insignificant in long run. Annual interest rate was found negative significant effect in short run but insignificant in long run. While total government expenditure was insignificant in both short and long run. Inflation has a negative relation with domestic private investment in both short and long run, therefore the study suggested that policymakers should recognize the cause for fluctuations in inflation and keep in a stable manner.
{"title":"Trends and determinants of domestic private investment in Ethiopia: Time series analysis","authors":"Tale Geddafa","doi":"10.1080/23311916.2023.2283293","DOIUrl":"https://doi.org/10.1080/23311916.2023.2283293","url":null,"abstract":"Abstract The Ethiopian Investment Commission was established to formulate suitable investment policy with good investment climate that enables investors to operate in a more macroeconomic friendly environment. Despite all efforts, domestic private investment in Ethiopia is still in its early stages. Therefore, this study aimed to investigate the trends and determinants of domestic private investment in Ethiopia using a time series data over the period 1992–2022. To meet its goal, the study employed an Autoregressive Distributed Lag (ARDL) bounds testing approach through E-views version 12. The findings show that domestic private investment was negatively and significantly affected by the inflation rate, public investment, and real effective exchange rate over a period of both the short- and long-run. While domestic credit to the private sector, foreign direct investment, real GDP and trade openness were found to have positive and significant effect on domestic private investment in long run. Unemployment rate was found to have positive and significant effect in short run but insignificant in long run. Annual interest rate was found negative significant effect in short run but insignificant in long run. While total government expenditure was insignificant in both short and long run. Inflation has a negative relation with domestic private investment in both short and long run, therefore the study suggested that policymakers should recognize the cause for fluctuations in inflation and keep in a stable manner.","PeriodicalId":10464,"journal":{"name":"Cogent Engineering","volume":"188 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139215235","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}
Pub Date : 2023-11-28DOI: 10.1080/23311916.2023.2283337
M. Gedefaw
Abstract This study analyzed the trends of precipitation and temperature in two eco-regions, which represent the whole part of Ethiopia based on climate variations. Mann–Kendall, Sen’s slope estimator test and innovative trend analysis method were used to detect precipitation and temperature trends. The observed historical meteorological data from 1980 to 2016 were used to analyze the trends in this study. MATLAB software was used to analyze the trends of climate variability. The findings of this study showed that the trends of precipitation were statistically significant with a positive trend in Gondar (β = 1.84) and Bahir Dar (β = 1.80) of highland eco-regions, whereas a significant increasing trend was observed in Negele (β = 23.40) and Gewane (β = 0.10) of lowland eco-regions. However, Sekoru (β = 0.01) and Degahabur (β = 4.13) stations showed a significant decreasing trend. As far as trends of temperature are concerned, a statistically significant increasing trend of temperature was observed in Gondar (β = 0.04) and Bahir Dar (β = 0.08), and a sharp significant decreasing trend was observed in Sekoru (β = 0.01) stations of highland eco-regions. The lowland eco-regions (Gewane (β = 0. 10), Degahabur (β = 0.03) and Negele (β = 0.07)) showed a statistically significant increasing trend. The consistency in precipitation and temperature trends over the two eco-regions of Ethiopia confirms the robustness of the change in trends. Further study should be done by taking more stations and datasets to reach a conclusion whether climate change has occurred or not. However, the findings of this study could provide insights for policy- and decision-makers to take proactive measures for climate change mitigation.
{"title":"Analysis of the trends of climate variability over two different eco-regions of Ethiopia","authors":"M. Gedefaw","doi":"10.1080/23311916.2023.2283337","DOIUrl":"https://doi.org/10.1080/23311916.2023.2283337","url":null,"abstract":"Abstract This study analyzed the trends of precipitation and temperature in two eco-regions, which represent the whole part of Ethiopia based on climate variations. Mann–Kendall, Sen’s slope estimator test and innovative trend analysis method were used to detect precipitation and temperature trends. The observed historical meteorological data from 1980 to 2016 were used to analyze the trends in this study. MATLAB software was used to analyze the trends of climate variability. The findings of this study showed that the trends of precipitation were statistically significant with a positive trend in Gondar (β = 1.84) and Bahir Dar (β = 1.80) of highland eco-regions, whereas a significant increasing trend was observed in Negele (β = 23.40) and Gewane (β = 0.10) of lowland eco-regions. However, Sekoru (β = 0.01) and Degahabur (β = 4.13) stations showed a significant decreasing trend. As far as trends of temperature are concerned, a statistically significant increasing trend of temperature was observed in Gondar (β = 0.04) and Bahir Dar (β = 0.08), and a sharp significant decreasing trend was observed in Sekoru (β = 0.01) stations of highland eco-regions. The lowland eco-regions (Gewane (β = 0. 10), Degahabur (β = 0.03) and Negele (β = 0.07)) showed a statistically significant increasing trend. The consistency in precipitation and temperature trends over the two eco-regions of Ethiopia confirms the robustness of the change in trends. Further study should be done by taking more stations and datasets to reach a conclusion whether climate change has occurred or not. However, the findings of this study could provide insights for policy- and decision-makers to take proactive measures for climate change mitigation.","PeriodicalId":10464,"journal":{"name":"Cogent Engineering","volume":"27 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139215173","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}
Pub Date : 2023-11-28DOI: 10.1080/23311916.2023.2287299
Y. Akil, S. Mangngenre, Sri Mawar Said, K. Amar, A. M. Shiddiq, Saiful Akil, Sri Mawar Mangngenre, Kifayah Said, M. AmarA, Shiddiq Yunus
Abstract This study aims to analyze vital indicators for urban consumer’s behavior regarding electricity saving appliances (ESA) to reduce energy consumption at home in Indonesia. The studied appliances are limited to two, refrigerator and air conditioner, as these appliances are the most dominant in consuming electricity energy. There are two equation models proposed for each appliance by using consumers’ perceptions (general and specific perceptions) and external (social environment, weather, and mass media) group variables, usage and habitual behaviors. Using stepwise regression and statistical approaches for 232 surveyed household consumers in Makassar city, the adjusted R2 value for four composed models is between 52% and 59%. Study findings reveal that specific perception significantly influences the usage of both appliances including the habit of consumers for energy saving. Among the examined external factors, the variable of mass media has significance in almost all models. Implications for policymakers suggest applying a priority approach in promoting energy saving to consumers with low specific perception based on the aspect of installed electric power capacity at home, and giving more information via mass media about attributes of ESA including introducing intervention strategies is essential to support sustainable electricity consumption from the consumer’s side.
{"title":"Factors influencing urban consumers on selecting electricity saving home appliances for managing energy consumption in Indonesia","authors":"Y. Akil, S. Mangngenre, Sri Mawar Said, K. Amar, A. M. Shiddiq, Saiful Akil, Sri Mawar Mangngenre, Kifayah Said, M. AmarA, Shiddiq Yunus","doi":"10.1080/23311916.2023.2287299","DOIUrl":"https://doi.org/10.1080/23311916.2023.2287299","url":null,"abstract":"Abstract This study aims to analyze vital indicators for urban consumer’s behavior regarding electricity saving appliances (ESA) to reduce energy consumption at home in Indonesia. The studied appliances are limited to two, refrigerator and air conditioner, as these appliances are the most dominant in consuming electricity energy. There are two equation models proposed for each appliance by using consumers’ perceptions (general and specific perceptions) and external (social environment, weather, and mass media) group variables, usage and habitual behaviors. Using stepwise regression and statistical approaches for 232 surveyed household consumers in Makassar city, the adjusted R2 value for four composed models is between 52% and 59%. Study findings reveal that specific perception significantly influences the usage of both appliances including the habit of consumers for energy saving. Among the examined external factors, the variable of mass media has significance in almost all models. Implications for policymakers suggest applying a priority approach in promoting energy saving to consumers with low specific perception based on the aspect of installed electric power capacity at home, and giving more information via mass media about attributes of ESA including introducing intervention strategies is essential to support sustainable electricity consumption from the consumer’s side.","PeriodicalId":10464,"journal":{"name":"Cogent Engineering","volume":"12 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139224358","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}
Pub Date : 2023-11-27DOI: 10.1080/23311916.2023.2283279
Praveena Krishna P S, Vishnu S, Abinash Dash, Vijay Babu Koreboina, Jayalakshmi N. S.
Abstract Research and development concerning the electrification of the easily affordable two-wheel vehicle segments operating at low power capacity are significant for a highly populated country like India to attain sustainable transportation. Hence, a novel approach is proposed in this paper focussing on the investigation of bi-directional quasi-Z source inverter (BD-qZSI) using a modified shoot through hysteresis current control (STHCC) loop for brushless direct current (BLDC)-motor-based low power electric vehicle (EV) applications to address this issue. The practical vehicle dynamics, without the computational burden of the complete drive cycle. are suitably established in this research work by achieving different speed and torque conditions with the inclusion of five different modes of operations consisting of three motoring modes (eco, coast, and wrap) and two regenerative braking modes (soft regen and hard regen). The combination of the closed loop speed control of BLDC motor involving PI control in cascade with modified STHCC for the operation of BD-qZSI is analysed in MATLAB/Simulink environement. The performance of the bidirectional power transfer in a single stage including regenerative braking is examined. The results confirm the validity of the proposed system for low-power EV applications. The modified STHCC is easy to implement with quick response compared to other control methods. The performance of single stage BD-qZSI is superior to the conventional two stage converter topologies and to that of Z source inverters. The commutation ripple observed in the torque profile is insignificant in low-power BLDC drive applications. The overall drivetrain efficiency of 84.82% is achieved at rated load condition.
摘要 对于印度这样一个人口众多的国家来说，研究和开发低功率运行的经济型两轮汽车电气化对实现可持续交通具有重要意义。因此，本文提出了一种新方法，重点研究基于无刷直流（BLDC）电机的低功率电动汽车（EV）应用中使用改进的射穿磁滞电流控制（STHCC）回路的双向准 Z 源逆变器（BD-qZSI），以解决这一问题。在这项研究工作中，通过实现不同的速度和扭矩条件，适当地建立了实际的车辆动力学，其中包括五种不同的运行模式，包括三种驾驶模式（环保、沿海和环绕）和两种再生制动模式（软再生和硬再生）。在 MATLAB/Simulink 环境中分析了无刷直流电机的闭环速度控制，包括级联 PI 控制和改进的 STHCC，以实现 BD-qZSI 的运行。研究了包括再生制动在内的单级双向功率传输性能。结果证实了所提系统在低功耗电动汽车应用中的有效性。与其他控制方法相比，改进后的 STHCC 易于实现且响应迅速。单级 BD-qZSI 的性能优于传统的两级转换器拓扑结构和 Z 源逆变器。在低功耗 BLDC 驱动应用中，转矩曲线中观察到的换向纹波微不足道。在额定负载条件下，传动系统的整体效率达到 84.82%。
{"title":"Investigation of bidirectional quasi Z-Source inverter for BLDC drive with modified shoot-through hysteresis current control in low power EV applications","authors":"Praveena Krishna P S, Vishnu S, Abinash Dash, Vijay Babu Koreboina, Jayalakshmi N. S.","doi":"10.1080/23311916.2023.2283279","DOIUrl":"https://doi.org/10.1080/23311916.2023.2283279","url":null,"abstract":"Abstract Research and development concerning the electrification of the easily affordable two-wheel vehicle segments operating at low power capacity are significant for a highly populated country like India to attain sustainable transportation. Hence, a novel approach is proposed in this paper focussing on the investigation of bi-directional quasi-Z source inverter (BD-qZSI) using a modified shoot through hysteresis current control (STHCC) loop for brushless direct current (BLDC)-motor-based low power electric vehicle (EV) applications to address this issue. The practical vehicle dynamics, without the computational burden of the complete drive cycle. are suitably established in this research work by achieving different speed and torque conditions with the inclusion of five different modes of operations consisting of three motoring modes (eco, coast, and wrap) and two regenerative braking modes (soft regen and hard regen). The combination of the closed loop speed control of BLDC motor involving PI control in cascade with modified STHCC for the operation of BD-qZSI is analysed in MATLAB/Simulink environement. The performance of the bidirectional power transfer in a single stage including regenerative braking is examined. The results confirm the validity of the proposed system for low-power EV applications. The modified STHCC is easy to implement with quick response compared to other control methods. The performance of single stage BD-qZSI is superior to the conventional two stage converter topologies and to that of Z source inverters. The commutation ripple observed in the torque profile is insignificant in low-power BLDC drive applications. The overall drivetrain efficiency of 84.82% is achieved at rated load condition.","PeriodicalId":10464,"journal":{"name":"Cogent Engineering","volume":"4 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139233087","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}
Pub Date : 2023-11-27DOI: 10.1080/23311916.2023.2283282
Ashraf Alam, Atasi Mohanty
Abstract Efforts at the intersection of technology and pedagogy converge upon four pivotal axes that collectively delineate the future educational landscape. These axes, namely mobility, interactivity, artificial intelligence (AI), and technological learning tools like games and augmented reality, encompass the domain of educational transformation. The fusion of these elements necessitates the development of a mobile-interactive paradigm that duly acknowledes the learner’s temporal availability and optimal convenience. Currently, technology is already integrated into the educational realm. However, its diverse manifestations across various contexts underscore the urgent need to integrate and amalgamate these facets within pedagogical frameworks that prioritize students’ erudition. This research undertakes a comprehensive analysis of multifarious technological modalities and puts forth a harmonized model that could furnish a foundational structure for classroom instruction. Central to this paradigm is the recognition of the paramountcy of intelligent tutoring systems, which serve to democratize access to tutoring. By imbuing these systems with advanced AI capabilities, learners can benefit from personalized and adaptive support, irrespective of their location or socioeconomic background. Furthermore, the significance of conducting technological experiments cannot be understated, as it allows for the exploration of new frontiers and the subsequent application of findings to “teaching-learning models.” These models harness a diverse range of interaction patterns to enhance the educational experience. By embracing these transformative elements, educational frameworks can better cater to the evolving needs of learners, while intelligent tutoring systems and ongoing technological experimentation serve as cornerstones in advancing the educational journey.
{"title":"Educational technology: Exploring the convergence of technology and pedagogy through mobility, interactivity, AI, and learning tools","authors":"Ashraf Alam, Atasi Mohanty","doi":"10.1080/23311916.2023.2283282","DOIUrl":"https://doi.org/10.1080/23311916.2023.2283282","url":null,"abstract":"Abstract Efforts at the intersection of technology and pedagogy converge upon four pivotal axes that collectively delineate the future educational landscape. These axes, namely mobility, interactivity, artificial intelligence (AI), and technological learning tools like games and augmented reality, encompass the domain of educational transformation. The fusion of these elements necessitates the development of a mobile-interactive paradigm that duly acknowledes the learner’s temporal availability and optimal convenience. Currently, technology is already integrated into the educational realm. However, its diverse manifestations across various contexts underscore the urgent need to integrate and amalgamate these facets within pedagogical frameworks that prioritize students’ erudition. This research undertakes a comprehensive analysis of multifarious technological modalities and puts forth a harmonized model that could furnish a foundational structure for classroom instruction. Central to this paradigm is the recognition of the paramountcy of intelligent tutoring systems, which serve to democratize access to tutoring. By imbuing these systems with advanced AI capabilities, learners can benefit from personalized and adaptive support, irrespective of their location or socioeconomic background. Furthermore, the significance of conducting technological experiments cannot be understated, as it allows for the exploration of new frontiers and the subsequent application of findings to “teaching-learning models.” These models harness a diverse range of interaction patterns to enhance the educational experience. By embracing these transformative elements, educational frameworks can better cater to the evolving needs of learners, while intelligent tutoring systems and ongoing technological experimentation serve as cornerstones in advancing the educational journey.","PeriodicalId":10464,"journal":{"name":"Cogent Engineering","volume":"27 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139233588","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}
Pub Date : 2023-11-23DOI: 10.1080/23311916.2023.2283316
L. Shbeeb
Abstract Road authorities are committed to improving community infrastructure through Bus Rapid Transit (BRT) projects. Yet, these initiatives often disrupt traffic, as seen in the Amman BRT project. A study assessed traffic conditions during various stages to address these disruptions, including simulated BRT operations. The research collected data on traffic volume, travel time, delays, and transit ridership before, during, and after construction and after BRT operations began. As a case study, the study focused on the impact of Amman’s first mass transit system at the Yajouz intersection. Traffic volumes decreased by 28% during construction, reducing delays significantly from 118.03 to 91.04 seconds. Although average speeds increased slightly (one km/h, on average), travel time doubled, negatively impacting 84% of businesses due to considering alternative routes for traveller destinations. However, delays significantly reduced after construction to 58 seconds per vehicle despite the higher traffic volume. Traffic simulations during construction underestimated observed delays (53.5 seconds per vehicle vs. 73.7 seconds per vehicle), still indicating a Level of Service (LOS) E. In BRT operation, modelled delays (55.8 seconds per vehicle) were lower than observed (63.8 seconds per vehicle), maintaining same LOS level. BRT minimally impacted ridership, an expected outcome given its trial phase. Environmental assessments revealed emissions peaking during construction, with a 25% modal shift to BRT yielding the lowest emissions. The study stresses sustainable urban mobility, advocating for meticulous planning, adaptable policies, and public awareness, emphasizing the need for detailed pedestrian research in this context.
{"title":"Traffic and environmental impacts of constructing and operating a BRT service: Case study in Amman, Jordan","authors":"L. Shbeeb","doi":"10.1080/23311916.2023.2283316","DOIUrl":"https://doi.org/10.1080/23311916.2023.2283316","url":null,"abstract":"Abstract Road authorities are committed to improving community infrastructure through Bus Rapid Transit (BRT) projects. Yet, these initiatives often disrupt traffic, as seen in the Amman BRT project. A study assessed traffic conditions during various stages to address these disruptions, including simulated BRT operations. The research collected data on traffic volume, travel time, delays, and transit ridership before, during, and after construction and after BRT operations began. As a case study, the study focused on the impact of Amman’s first mass transit system at the Yajouz intersection. Traffic volumes decreased by 28% during construction, reducing delays significantly from 118.03 to 91.04 seconds. Although average speeds increased slightly (one km/h, on average), travel time doubled, negatively impacting 84% of businesses due to considering alternative routes for traveller destinations. However, delays significantly reduced after construction to 58 seconds per vehicle despite the higher traffic volume. Traffic simulations during construction underestimated observed delays (53.5 seconds per vehicle vs. 73.7 seconds per vehicle), still indicating a Level of Service (LOS) E. In BRT operation, modelled delays (55.8 seconds per vehicle) were lower than observed (63.8 seconds per vehicle), maintaining same LOS level. BRT minimally impacted ridership, an expected outcome given its trial phase. Environmental assessments revealed emissions peaking during construction, with a 25% modal shift to BRT yielding the lowest emissions. The study stresses sustainable urban mobility, advocating for meticulous planning, adaptable policies, and public awareness, emphasizing the need for detailed pedestrian research in this context.","PeriodicalId":10464,"journal":{"name":"Cogent Engineering","volume":"18 4","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139244925","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}
Pub Date : 2023-11-21DOI: 10.1080/23311916.2023.2283297
M. Aredo, T. K. Lohani, A. Mohammed
Abstract Groundwater is the primary source of water supply in Ethiopia. The study area was challenged due to increasing water demand, uneven water resource distribution, and noticeable changes in groundwater levels. The study focused on the examining of existing abstraction and future water demand scenarios on groundwater balance in the Weyib watershed using the WetSpass-M and MODFLOW-2005 models. The input datasets, such as aquifer properties, observed groundwater heads, hydrogeology, groundwater recharge, the Digital Elevation Model (DEM), and hydrological data were used. Datasets were prepared to better represent subsurface hydrology and its future demand effects evaluated using calibrated steady-state numerical groundwater modeling. The WetSpass-M and MODFLOW-2005 models depicted good performances during the simulations of groundwater recharge and groundwater budget under existing abstractions and estimated demand scenarios, respectively. The mean annual groundwater recharge estimated was 177.66 mm/year. The existing groundwater abstraction was 34,686.39, estimated short-term and long-term water demand scenarios were 72,113.61 and 93,795.57 m3/day, respectively. The upstream area has the highest groundwater head and recharge, while decreasing as it approaches the Weyib watershed outlet. During the outflow groundwater budget, the groundwater abstractions increased as expenses of river leakage and head dept. bounds increased. Moreover, the increasing groundwater withdrawal would reduce groundwater heads, and the estimated future water demand scenarios would substantially impact the groundwater budget, which would also have an impact on the watershed hydrology and ecosystem.
{"title":"Numerical groundwater modelling under changing water abstraction in Weyib watershed, Ethiopia","authors":"M. Aredo, T. K. Lohani, A. Mohammed","doi":"10.1080/23311916.2023.2283297","DOIUrl":"https://doi.org/10.1080/23311916.2023.2283297","url":null,"abstract":"Abstract Groundwater is the primary source of water supply in Ethiopia. The study area was challenged due to increasing water demand, uneven water resource distribution, and noticeable changes in groundwater levels. The study focused on the examining of existing abstraction and future water demand scenarios on groundwater balance in the Weyib watershed using the WetSpass-M and MODFLOW-2005 models. The input datasets, such as aquifer properties, observed groundwater heads, hydrogeology, groundwater recharge, the Digital Elevation Model (DEM), and hydrological data were used. Datasets were prepared to better represent subsurface hydrology and its future demand effects evaluated using calibrated steady-state numerical groundwater modeling. The WetSpass-M and MODFLOW-2005 models depicted good performances during the simulations of groundwater recharge and groundwater budget under existing abstractions and estimated demand scenarios, respectively. The mean annual groundwater recharge estimated was 177.66 mm/year. The existing groundwater abstraction was 34,686.39, estimated short-term and long-term water demand scenarios were 72,113.61 and 93,795.57 m3/day, respectively. The upstream area has the highest groundwater head and recharge, while decreasing as it approaches the Weyib watershed outlet. During the outflow groundwater budget, the groundwater abstractions increased as expenses of river leakage and head dept. bounds increased. Moreover, the increasing groundwater withdrawal would reduce groundwater heads, and the estimated future water demand scenarios would substantially impact the groundwater budget, which would also have an impact on the watershed hydrology and ecosystem.","PeriodicalId":10464,"journal":{"name":"Cogent Engineering","volume":"107 3","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139252401","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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