Today, as the process of urbanization is accelerating, the country builds an extensive transportation network through bridges and roads, which facilitates the daily travel of the people and greatly promotes the development of the national economy. However, due to the cross-sea bridge spanning the bay, the overall scale, the complex construction environment, and the high technology content, the objective existence of risk factors in the construction process cannot be completely avoided. In the construction of cross-sea bridges, once a construction safety accident occurs, it will cause irreparable losses to the construction of the project. Taking Hangzhou Bay Bridge as an actual case, using the Analytic Hierarchy Process to identify possible risk factors during the life cycle of Hangzhou Bay Bridge, establish a corresponding risk evaluation system to evaluate the importance and probability of risk, and to rank the importance of risks, and control the corresponding construction risks by adopting measures such as risk transfer and risk retention. The research example shows that the project risk of the cross-sea bridge project can be combined with the analytic hierarchy process to identify, analyze and evaluate the importance of the various risks faced by the project, so as to adopt corresponding avoidance methods to reduce the project risk loss and achieve the project construction expectations Target.
{"title":"Research on Risk Management of Cross-Sea Bridges Based on Analytic Hierarchy Process—Taking Hangzhou Bay Bridge as an Example","authors":"Wenxing Zhang","doi":"10.4236/wjet.2021.93044","DOIUrl":"https://doi.org/10.4236/wjet.2021.93044","url":null,"abstract":"Today, as the process of urbanization is accelerating, the country builds an extensive transportation network through bridges and roads, which facilitates the daily travel of the people and greatly promotes the development of the national economy. However, due to the cross-sea bridge spanning the bay, the overall scale, the complex construction environment, and the high technology content, the objective existence of risk factors in the construction process cannot be completely avoided. In the construction of cross-sea bridges, once a construction safety accident occurs, it will cause irreparable losses to the construction of the project. Taking Hangzhou Bay Bridge as an actual case, using the Analytic Hierarchy Process to identify possible risk factors during the life cycle of Hangzhou Bay Bridge, establish a corresponding risk evaluation system to evaluate the importance and probability of risk, and to rank the importance of risks, and control the corresponding construction risks by adopting measures such as risk transfer and risk retention. The research example shows that the project risk of the cross-sea bridge project can be combined with the analytic hierarchy process to identify, analyze and evaluate the importance of the various risks faced by the project, so as to adopt corresponding avoidance methods to reduce the project risk loss and achieve the project construction expectations Target.","PeriodicalId":344331,"journal":{"name":"World Journal of Engineering and Technology","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124958358","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}
Keeping pressure gradient is an excellent approach to prevent the reveal of airflow direction and cross infection in manufacturing circumstances of pharmaceutical cleanrooms, thus how to keep cleanroom’s pressure is critical. In the paper, we study a positive pressure pharmaceutical cleanroom system which is composed by a cleanroom and an airlock. We divide the system’s disturbances into step disturbance, ramp disturbance and sine wave disturbance. We design its pressure gradient control strategies, including CAV control, PID control and active-disturbance-rejection-control. We build the system’s model and make simulations based on Matlab/Simulink software platform. Results show that active-disturbance-rejection-control algorithm has good capabilities for shorter responding time and lower overshot of the pressure gradient. The results reveal that active-disturbance-rejection-control method has good control performances in responding time, accuracy and disturbance rejection.
{"title":"Pressure Gradient Control Strategies Based on Disturbance Rejection for Typical Pharmaceutical Cleanrooms","authors":"Chunwang Li, Xiaojun Ma, Chun-E. Huang","doi":"10.4236/wjet.2021.93038","DOIUrl":"https://doi.org/10.4236/wjet.2021.93038","url":null,"abstract":"Keeping pressure gradient is an excellent approach to prevent the reveal of airflow direction and cross infection in manufacturing circumstances of pharmaceutical cleanrooms, thus how to keep cleanroom’s pressure is critical. In the paper, we study a positive pressure pharmaceutical cleanroom system which is composed by a cleanroom and an airlock. We divide the system’s disturbances into step disturbance, ramp disturbance and sine wave disturbance. We design its pressure gradient control strategies, including CAV control, PID control and active-disturbance-rejection-control. We build the system’s model and make simulations based on Matlab/Simulink software platform. Results show that active-disturbance-rejection-control algorithm has good capabilities for shorter responding time and lower overshot of the pressure gradient. The results reveal that active-disturbance-rejection-control method has good control performances in responding time, accuracy and disturbance rejection.","PeriodicalId":344331,"journal":{"name":"World Journal of Engineering and Technology","volume":"84 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128608627","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}
Today we are in a technologically explosive information society. The cross- border integration of manufacturing and construction is prefabricated buildings. The cross-border integration of construction and IT is BIM technology, and the emergence of BIM technology provides new ideas for prefabricated building, and the integration of prefabricated building and BIM technology realizes the construction industrialization. This paper studies the application of BIM technology in prefabricated buildings, including the design phase, construction and assembly phase, operation and maintenance phase, and application analysis of related software, so as to improve the high efficiency, high quality and high precision development of prefabricated projects, and promote domestic green environmental protection. The development of the construction industry provides reference value for the application of BIM technology in prefabricated buildings.
{"title":"Research on the Integration of BIM Technology in Prefabricated Buildings","authors":"Yuge Wang, Yueming Wang","doi":"10.4236/wjet.2021.93040","DOIUrl":"https://doi.org/10.4236/wjet.2021.93040","url":null,"abstract":"Today we are in a technologically explosive information society. The cross- border integration of manufacturing and construction is prefabricated buildings. The cross-border integration of construction and IT is BIM technology, and the emergence of BIM technology provides new ideas for prefabricated building, and the integration of prefabricated building and BIM technology realizes the construction industrialization. This paper studies the application of BIM technology in prefabricated buildings, including the design phase, construction and assembly phase, operation and maintenance phase, and application analysis of related software, so as to improve the high efficiency, high quality and high precision development of prefabricated projects, and promote domestic green environmental protection. The development of the construction industry provides reference value for the application of BIM technology in prefabricated buildings.","PeriodicalId":344331,"journal":{"name":"World Journal of Engineering and Technology","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123307079","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}
Nablus-Al Bathan Road which connects Nablus City and Jordan Valley in the West Bank of Palestinian Territories, was widened, reconstructed and rehabilitated in 2009, however, between 2010 and 2012 road defects at several locations were observed. To fix these defects especially at station 2 + 100 of the road, soil replacement in the body of the road and big boulders to support the edge of the road were used. Unfortunately, large settlement occurred in the part of the road under maintenance and more sliding and slope instability occurred in the road at station 2+ 100 during the remedial measures. Studies were carried out to find the causes of this problem. These included surveying of the area, geotechnical studies (making trial pits, performing geophysical seismic exploration and digging out several boreholes), in addition to slope stability analysis. It was found that the main causes of landslides were types of soils at the site, high slopes, groundwater recharged from rainfall and changing of weights (cut and fill). Remedy measures were suggested to overcome sliding problem based on available resources and local technology.
{"title":"Slope Instability at Nablus-Al Bathan Road, Palestinian Territories (Causes, Analysis and Remedy Measurements)","authors":"Isam Jardaneh, Sami Hijjawi, George Odeh","doi":"10.4236/wjet.2021.93036","DOIUrl":"https://doi.org/10.4236/wjet.2021.93036","url":null,"abstract":"Nablus-Al Bathan Road which connects Nablus City and Jordan Valley in the West Bank of Palestinian Territories, was widened, reconstructed and rehabilitated in 2009, however, between 2010 and 2012 road defects at several locations were observed. To fix these defects especially at station 2 + 100 of the road, soil replacement in the body of the road and big boulders to support the edge of the road were used. Unfortunately, large settlement occurred in the part of the road under maintenance and more sliding and slope instability occurred in the road at station 2+ 100 during the remedial measures. Studies were carried out to find the causes of this problem. These included surveying of the area, geotechnical studies (making trial pits, performing geophysical seismic exploration and digging out several boreholes), in addition to slope stability analysis. It was found that the main causes of landslides were types of soils at the site, high slopes, groundwater recharged from rainfall and changing of weights (cut and fill). Remedy measures were suggested to overcome sliding problem based on available resources and local technology.","PeriodicalId":344331,"journal":{"name":"World Journal of Engineering and Technology","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121705760","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}
The car-following models are the research basis of traffic flow theory and microscopic traffic simulation. Among the previous work, the theory-driven models are dominant, while the data-driven ones are relatively rare. In recent years, the related technologies of Intelligent Transportation System (ITS) re- presented by the Vehicles to Everything (V2X) technology have been developing rapidly. Utilizing the related technologies of ITS, the large-scale vehicle microscopic trajectory data with high quality can be acquired, which provides the research foundation for modeling the car-following behavior based on the data-driven methods. According to this point, a data-driven car-following model based on the Random Forest (RF) method was constructed in this work, and the Next Generation Simulation (NGSIM) dataset was used to calibrate and train the constructed model. The Artificial Neural Network (ANN) model, GM model, and Full Velocity Difference (FVD) model are em- ployed to comparatively verify the proposed model. The research results suggest that the model proposed in this work can accurately describe the car- following behavior with better performance under multiple performance indicators.
{"title":"A Data-Driven Car-Following Model Based on the Random Forest","authors":"Huili Shi, Ting-Yen Wang, Fusheng Zhong, Hanqing Wang, Junyan Han, Xiaoyuan Wang","doi":"10.4236/wjet.2021.93033","DOIUrl":"https://doi.org/10.4236/wjet.2021.93033","url":null,"abstract":"The car-following models are the research basis of traffic flow theory and microscopic traffic simulation. Among the previous work, the theory-driven models are dominant, while the data-driven ones are relatively rare. In recent years, the related technologies of Intelligent Transportation System (ITS) re- presented by the Vehicles to Everything (V2X) technology have been developing rapidly. Utilizing the related technologies of ITS, the large-scale vehicle microscopic trajectory data with high quality can be acquired, which provides the research foundation for modeling the car-following behavior based on the data-driven methods. According to this point, a data-driven car-following model based on the Random Forest (RF) method was constructed in this work, and the Next Generation Simulation (NGSIM) dataset was used to calibrate and train the constructed model. The Artificial Neural Network (ANN) model, GM model, and Full Velocity Difference (FVD) model are em- ployed to comparatively verify the proposed model. The research results suggest that the model proposed in this work can accurately describe the car- following behavior with better performance under multiple performance indicators.","PeriodicalId":344331,"journal":{"name":"World Journal of Engineering and Technology","volume":"94 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125940796","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}
Jean Blaise Teguia, G. Kenné, A. S. T. Kammogne, G. C. Fouokeng, Arnaud Nanfak
This work proposes an alternative strategy to the use of a speed sensor in the implementation of active and reactive power based model reference adaptive system (PQ-MRAS) estimator in order to calculate the rotor and stator resistances of an induction motor (IM) and the use of these parameters for the detection of inter-turn short circuits (ITSC) faults in the stator of this motor. The rotor and stator resistance estimation part of the IM is performed by the PQ-MRAS method in which the rotor angular velocity is reconstructed from the interconnected high gain observer (IHGO). The ITSC fault detection part is done by the derivation of stator resistance estimated by the PQ-MRAS estimator. In addition to the speed sensorless detection of ITSC faults of the IM, an approach to determine the number of shorted turns based on the difference between the phase current of the healthy and faulty machine is proposed. Simulation results obtained from the MATLAB/Simulink platform have shown that the PQ-MRAS estimator using an interconnected high-gain observer gives very similar results to those using the speed sensor. The estimation errors in the cases of speed variation and load torque are almost identical. Variations in stator and rotor resistances influence the performance of the observer and lead to poor estimation of the rotor resistance. The results of ITSC fault detection using IHGO are very similar to the results in the literature using the same diagnostic approach with a speed sensor.
{"title":"The Detection of Inter-Turn Short Circuits in the Stator Windings of Sensorless Operating Induction Motors","authors":"Jean Blaise Teguia, G. Kenné, A. S. T. Kammogne, G. C. Fouokeng, Arnaud Nanfak","doi":"10.4236/wjet.2021.93046","DOIUrl":"https://doi.org/10.4236/wjet.2021.93046","url":null,"abstract":"This work proposes an alternative strategy to the use of a speed sensor in the implementation of active and reactive power based model reference adaptive system (PQ-MRAS) estimator in order to calculate the rotor and stator resistances of an induction motor (IM) and the use of these parameters for the detection of inter-turn short circuits (ITSC) faults in the stator of this motor. The rotor and stator resistance estimation part of the IM is performed by the PQ-MRAS method in which the rotor angular velocity is reconstructed from the interconnected high gain observer (IHGO). The ITSC fault detection part is done by the derivation of stator resistance estimated by the PQ-MRAS estimator. In addition to the speed sensorless detection of ITSC faults of the IM, an approach to determine the number of shorted turns based on the difference between the phase current of the healthy and faulty machine is proposed. Simulation results obtained from the MATLAB/Simulink platform have shown that the PQ-MRAS estimator using an interconnected high-gain observer gives very similar results to those using the speed sensor. The estimation errors in the cases of speed variation and load torque are almost identical. Variations in stator and rotor resistances influence the performance of the observer and lead to poor estimation of the rotor resistance. The results of ITSC fault detection using IHGO are very similar to the results in the literature using the same diagnostic approach with a speed sensor.","PeriodicalId":344331,"journal":{"name":"World Journal of Engineering and Technology","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128505122","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}
Construction project management is an important aspect of civil engineering construction. How to use scientific and efficient methods to effectively manage construction projects is the focus of construction project development under the current situation. This article discusses the application of fuzzy mathematics in construction project management. The study found that in the process of construction project management, it was found that a single fuzzy mathematical method was difficult to adapt to the current complex and changeable construction projects. Combining fuzzy mathematics with other management methods and computer applications can better simplify complex things, reduce human subjectivity, increase calculation speed, and achieve a combination of qualitative and quantitative research; selection of optimization schemes and risk assessment, etc. All have a good effect, and can better deal with possible or uncertain things and emergencies in the process of project management. At the same time, combining fuzzy mathematics with heuristic algorithms or meta-heuristic algorithms can make research more objective, improve management efficiency and calculation speed.
{"title":"Summary of Application of Fuzzy Mathematics in Construction Project Management","authors":"Dongyou Tong, Yueming Wang","doi":"10.4236/wjet.2021.93028","DOIUrl":"https://doi.org/10.4236/wjet.2021.93028","url":null,"abstract":"Construction project management is an important aspect of civil engineering construction. How to use scientific and efficient methods to effectively manage construction projects is the focus of construction project development under the current situation. This article discusses the application of fuzzy mathematics in construction project management. The study found that in the process of construction project management, it was found that a single fuzzy mathematical method was difficult to adapt to the current complex and changeable construction projects. Combining fuzzy mathematics with other management methods and computer applications can better simplify complex things, reduce human subjectivity, increase calculation speed, and achieve a combination of qualitative and quantitative research; selection of optimization schemes and risk assessment, etc. All have a good effect, and can better deal with possible or uncertain things and emergencies in the process of project management. At the same time, combining fuzzy mathematics with heuristic algorithms or meta-heuristic algorithms can make research more objective, improve management efficiency and calculation speed.","PeriodicalId":344331,"journal":{"name":"World Journal of Engineering and Technology","volume":"103 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115669110","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}
The mechanical behavior and indentation creep of Al-20 wt% Zn bearing alloy has been modified with adding 0.2 wt%, 0.5 wt%, 1 wt%, 1.5 wt% Sn. These bearing alloys were prepared by melt spinning technique. The scanning electron microscopy (SEM) was used to study the morphology of the melt spun alloys and x-ray diffractometer (XRD) for the identification of the phases pre- sent in these melt-spun bearing alloys. The results show that the structure of Al80-x-Zn20-SnX (X = 0.2%, 0.5%, 1% and 1.5%) bearing alloys is characterized by the presence of α-Al of FCC structure and SnZn intermetallic compound of anorthic structure. The Al-20Zn-1.5Sn has a smaller crystallite size and grain size as indicated from X-ray and SEM analysis respectively, which leading to the enhancement of the mechanical properties. The mechanical properties and indentation creep of these bearing alloys were studied by tensile test machine and vickers indentation testing at room temperature, respectively. The Al-20Zn-1.5Sn has higher hardness value and creep resistance than other alloys. This was attributed to the strengthen effect of Sn as a strong solid solution element in Al-matrix. The stress exponent values in the range 2.4 - 4.2 indicate that the grain boundary sliding is the possible mechanism during room temperature creep deformation of melt-spun Al-Zn-Sn bearing alloys.
{"title":"Microstructures and Mechanical Properties of Al-Zn-Sn Bearing Alloys for High Performance Applications","authors":"N. A. Abdelhakim, R. Shalaby","doi":"10.4236/wjet.2021.93045","DOIUrl":"https://doi.org/10.4236/wjet.2021.93045","url":null,"abstract":"The mechanical behavior and indentation creep of Al-20 wt% Zn bearing alloy has been modified with adding 0.2 wt%, 0.5 wt%, 1 wt%, 1.5 wt% Sn. These bearing alloys were prepared by melt spinning technique. The scanning electron microscopy (SEM) was used to study the morphology of the melt spun alloys and x-ray diffractometer (XRD) for the identification of the phases pre- sent in these melt-spun bearing alloys. The results show that the structure of Al80-x-Zn20-SnX (X = 0.2%, 0.5%, 1% and 1.5%) bearing alloys is characterized by the presence of α-Al of FCC structure and SnZn intermetallic compound of anorthic structure. The Al-20Zn-1.5Sn has a smaller crystallite size and grain size as indicated from X-ray and SEM analysis respectively, which leading to the enhancement of the mechanical properties. The mechanical properties and indentation creep of these bearing alloys were studied by tensile test machine and vickers indentation testing at room temperature, respectively. The Al-20Zn-1.5Sn has higher hardness value and creep resistance than other alloys. This was attributed to the strengthen effect of Sn as a strong solid solution element in Al-matrix. The stress exponent values in the range 2.4 - 4.2 indicate that the grain boundary sliding is the possible mechanism during room temperature creep deformation of melt-spun Al-Zn-Sn bearing alloys.","PeriodicalId":344331,"journal":{"name":"World Journal of Engineering and Technology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130920346","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}
This paper presents a model to simulate the evolution of COVID-19 in the Cameroonian context. The presented model SISDH stands for Susceptible, Infected, Severe, Died, and Healed is made up of the mixture of a Multi-Agent System (SMA) and a SIR (Susceptible, Infected, Recovered)-based model, and mainly addresses the problem of modelling the evolution of pandemics with a high transmission rate. Multi-agent systems are used to design the SIR model’s entities, namely the habitants of the region subject to the study. The experimentation carried out showed that the combination of the two concepts favours rapid decision-making. For example, the requirement to wear a mask or strict adherence to social distancing reduces the risk of spread. The application of these tough measures had theoretically leveled down the spreading of the epidemic. Besides the lowering of the number of cases when strict measures were applied, we also highlighted a significant reduction of deaths and severe illness which is a concomitant result of the lockdown. On the other hand, our experiments revealed a peak of infections a few steps after the beginning when no restrictions are made for barrier measures. The peak is followed by a sudden decrease in infection which might convey immunity of the population.
{"title":"SISDH: A Model Based on SMAs and SIRs for the Simulation of the Evolution of COVID-19 in Cameroon","authors":"Batchakui Bernabe, Fandio Esdras, Ebouky Brown, Kwate Loïc, Waffo Stephane","doi":"10.4236/wjet.2021.93035","DOIUrl":"https://doi.org/10.4236/wjet.2021.93035","url":null,"abstract":"This paper presents a model to simulate the evolution of COVID-19 in the Cameroonian context. The presented model SISDH stands for Susceptible, Infected, Severe, Died, and Healed is made up of the mixture of a Multi-Agent System (SMA) and a SIR (Susceptible, Infected, Recovered)-based model, and mainly addresses the problem of modelling the evolution of pandemics with a high transmission rate. Multi-agent systems are used to design the SIR model’s entities, namely the habitants of the region subject to the study. The experimentation carried out showed that the combination of the two concepts favours rapid decision-making. For example, the requirement to wear a mask or strict adherence to social distancing reduces the risk of spread. The application of these tough measures had theoretically leveled down the spreading of the epidemic. Besides the lowering of the number of cases when strict measures were applied, we also highlighted a significant reduction of deaths and severe illness which is a concomitant result of the lockdown. On the other hand, our experiments revealed a peak of infections a few steps after the beginning when no restrictions are made for barrier measures. The peak is followed by a sudden decrease in infection which might convey immunity of the population.","PeriodicalId":344331,"journal":{"name":"World Journal of Engineering and Technology","volume":"115 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132011719","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}
The present study makes use of two distinct production methods. The first method involves producing 1010 steel-based materials containing SiC, MgO, H3BO3, and B4C (wt%10 - wt%30) with varying weights through powder metallurgy. This step was followed by hot pressing. In the second group, after all the chemicals were stirred, 20 ml of epoxy and epoxy hardener were added to the mixture. Then, the mixture was set aside to harden. XRD and SEM-EDS analyses were conducted on the mixture to observe the morphological impacts. Furthermore, friction coefficient values of the materials were also identified following wear tests under varying weights. The XRD analyses revealed the phase structures of Fe3C, SiC, MgO, H3BO3, B4C, and Fe2O3. As for the SEM-EDS analyses, they concluded the surface appearance of S60 and S55B20, the hot-pressed materials, dependent on liquid phase sintering. SEM of epoxy- based S60E20 and S55B20E20 revealed white spherical structures and a flat matrix structure with shallow surface holes. In the pin-on-disc wear experiment, the friction coefficient value was reduced with the addition of SiC, MgO, and H3BO3 (S60) to 1010 steel (S100). By adding various amounts of B4C, the friction coefficient was reduced even further, resulting in the improvement of wear properties.
{"title":"Analysing the Microstructures and Pin-on-Disc Wear Properties of 1010 Steel-Based and B4C-Added Materials Produced through Powder Metallurgy","authors":"M. Demirel, V. Koç","doi":"10.4236/wjet.2021.93047","DOIUrl":"https://doi.org/10.4236/wjet.2021.93047","url":null,"abstract":"The present study makes use of two distinct production methods. The first method involves producing 1010 steel-based materials containing SiC, MgO, H3BO3, and B4C (wt%10 - wt%30) with varying weights through powder metallurgy. This step was followed by hot pressing. In the second group, after all the chemicals were stirred, 20 ml of epoxy and epoxy hardener were added to the mixture. Then, the mixture was set aside to harden. XRD and SEM-EDS analyses were conducted on the mixture to observe the morphological impacts. Furthermore, friction coefficient values of the materials were also identified following wear tests under varying weights. The XRD analyses revealed the phase structures of Fe3C, SiC, MgO, H3BO3, B4C, and Fe2O3. As for the SEM-EDS analyses, they concluded the surface appearance of S60 and S55B20, the hot-pressed materials, dependent on liquid phase sintering. SEM of epoxy- based S60E20 and S55B20E20 revealed white spherical structures and a flat matrix structure with shallow surface holes. In the pin-on-disc wear experiment, the friction coefficient value was reduced with the addition of SiC, MgO, and H3BO3 (S60) to 1010 steel (S100). By adding various amounts of B4C, the friction coefficient was reduced even further, resulting in the improvement of wear properties.","PeriodicalId":344331,"journal":{"name":"World Journal of Engineering and Technology","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131172315","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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