Pub Date : 2022-09-15DOI: 10.5614/j.eng.technol.sci.2022.54.5.11
Nguyễn Phụ Thượng Lưu, L. H. Anh
This study simulated and evaluated the safety of a small car structure in a collision with the rear of a truck. The parameters of bumpers currently used in Vietnam were employed to build a model of the rear truck bumper. The setting of simulation conditions was based on the NCAP (New Car Assessment Program) crash test. According to actual crash conditions, a collision simulation was performed with different vehicle speeds from 40 to 60 km/h, corresponding to the case of a passenger vehicle moving in a city colliding with a truck standing still. In addition, the percentage of rear-end collision was also taken into account, just like in real-world collisions, at 25%, 50%, and full rear impact. The simulation results were analyzed and evaluated according to the IIHS rating (Institute Insurance for Highway Safety). The results from different case studies showed that the rear bumper typically used on trucks is only safe for passenger cars in a collision at a low speed of 40 km/h and that in a collision at a higher speed will affect the passenger’s safe space and cause high injuries and casualties. Therefore, it is necessary to improve safety by optimizing the rear bumper design and the frontal structure of the small car chassis.
本研究模拟并评估了小型汽车结构与卡车后部碰撞时的安全性。采用越南目前使用的保险杠参数，建立了货车后保险杠模型。模拟条件的设置基于NCAP (New Car Assessment Program)碰撞试验。根据实际碰撞情况，以40 ~ 60 km/h不同车速进行碰撞仿真，对应城市中行驶的乘用车与静止不动的货车碰撞的情况。此外，还考虑了追尾碰撞的百分比，就像在现实世界的碰撞中一样，分别为25%、50%和完全的追尾碰撞。根据IIHS (Institute Insurance for Highway Safety)评级对仿真结果进行了分析和评价。不同案例研究的结果表明，通常用于卡车的后保险杠仅在40公里/小时的低速碰撞中对乘用车是安全的，而在更高速度的碰撞中会影响乘客的安全空间并造成高伤害和人员伤亡。因此，有必要通过优化后保险杠设计和小型车底盘正面结构来提高安全性。
{"title":"A Study on Small Vehicle Structure in Rear Under-Ride Impact by Using A CAE Based Methodology","authors":"Nguyễn Phụ Thượng Lưu, L. H. Anh","doi":"10.5614/j.eng.technol.sci.2022.54.5.11","DOIUrl":"https://doi.org/10.5614/j.eng.technol.sci.2022.54.5.11","url":null,"abstract":"This study simulated and evaluated the safety of a small car structure in a collision with the rear of a truck. The parameters of bumpers currently used in Vietnam were employed to build a model of the rear truck bumper. The setting of simulation conditions was based on the NCAP (New Car Assessment Program) crash test. According to actual crash conditions, a collision simulation was performed with different vehicle speeds from 40 to 60 km/h, corresponding to the case of a passenger vehicle moving in a city colliding with a truck standing still. In addition, the percentage of rear-end collision was also taken into account, just like in real-world collisions, at 25%, 50%, and full rear impact. The simulation results were analyzed and evaluated according to the IIHS rating (Institute Insurance for Highway Safety). The results from different case studies showed that the rear bumper typically used on trucks is only safe for passenger cars in a collision at a low speed of 40 km/h and that in a collision at a higher speed will affect the passenger’s safe space and cause high injuries and casualties. Therefore, it is necessary to improve safety by optimizing the rear bumper design and the frontal structure of the small car chassis.","PeriodicalId":15689,"journal":{"name":"Journal of Engineering and Technological Sciences","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41442028","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 : 2022-09-07DOI: 10.5614/j.eng.technol.sci.2022.54.5.7
Muhammad Saafan, M. Mohyaldinn, K. Elraies
Capillary pressure is a crucial input in reservoir simulation models. Generally, capillary pressure measurements are expensive and time-consuming; therefore, there is a limitation on the number of cores tested in the laboratory. Accordingly, numerous capillary pressure models have been suggested to match capillary pressure curves and overcome this limitation. This study developed a new fractal capillary pressure model by depicting the porous system as a bundle of tortuous triangular tubes. The model imitates the pores’ angularity, providing a more accurate representation of the pore system than smooth circular openings. Moreover, triangular tubes allow the wetting phase to be retained in the tube’s corners. A genetic algorithm was employed to match the capillary pressure curves and obtain the proposed model’s parameters. Capillary pressure data of eight low-permeability sandstone samples from the Khatatba formation in the Western Desert of Egypt were utilized to test the proposed model. The results revealed that the developed model reasonably matched the laboratory-measured data.
{"title":"An Improved Capillary Pressure Model for Fractal Porous Media: Application to Low-Permeability Sandstone","authors":"Muhammad Saafan, M. Mohyaldinn, K. Elraies","doi":"10.5614/j.eng.technol.sci.2022.54.5.7","DOIUrl":"https://doi.org/10.5614/j.eng.technol.sci.2022.54.5.7","url":null,"abstract":"Capillary pressure is a crucial input in reservoir simulation models. Generally, capillary pressure measurements are expensive and time-consuming; therefore, there is a limitation on the number of cores tested in the laboratory. Accordingly, numerous capillary pressure models have been suggested to match capillary pressure curves and overcome this limitation. This study developed a new fractal capillary pressure model by depicting the porous system as a bundle of tortuous triangular tubes. The model imitates the pores’ angularity, providing a more accurate representation of the pore system than smooth circular openings. Moreover, triangular tubes allow the wetting phase to be retained in the tube’s corners. A genetic algorithm was employed to match the capillary pressure curves and obtain the proposed model’s parameters. Capillary pressure data of eight low-permeability sandstone samples from the Khatatba formation in the Western Desert of Egypt were utilized to test the proposed model. The results revealed that the developed model reasonably matched the laboratory-measured data.","PeriodicalId":15689,"journal":{"name":"Journal of Engineering and Technological Sciences","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44132378","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 : 2022-09-06DOI: 10.5614/j.eng.technol.sci.2022.54.5.6
M. Asadi, F. Iranawati, Fairus Nafidya, Supriyadi Supriyadi, A. Talukder
The contamination of microplastics have been reported in a wide array of marine organisms, including bivalve molluscs. This study aimed to investigate the occurrence and abundance of microplastics in bivalves from coastal waters of Paciran, Lamongan, East Java, Indonesia. High population and anthropogenic activities in the area may lead the contamination of microplastics in its marine organisms. Microplastics were recovered from the soft tissues of three species of wild clams, Gafrarium tumidum, Anadara antiquata, and Venerupis philippinarum. In each species, microplastics were grouped based on their types and sizes. The extraction of microplastics was using 30% H2O2, while flotation method using NaCl was used to separate the dissolved liquid of the clam’s soft tissues. Microplastic ingestion was found in 99.23% of the clam samples with average concentration of 3.5 ± 2.8 items/individual and 3.2 ± 2.52 items/g. V. philippinarum had the highest microplastics concentration (4.9 ± 2.80 items/g and 5.6 ± 3.22 items/individual). Microplastic types from all samples were dominated by fibers (80.77%), in which 57% of them were less than 200 µm in size. The ubiquitous contamination of microplastics in clams of the coastal waters of Lamongan, Indonesia is serious concerns for marine food webs and human health.
{"title":"Microplastics in wild clams harvested from coastal waters of Lamongan, Indonesia","authors":"M. Asadi, F. Iranawati, Fairus Nafidya, Supriyadi Supriyadi, A. Talukder","doi":"10.5614/j.eng.technol.sci.2022.54.5.6","DOIUrl":"https://doi.org/10.5614/j.eng.technol.sci.2022.54.5.6","url":null,"abstract":"The contamination of microplastics have been reported in a wide array of marine organisms, including bivalve molluscs. This study aimed to investigate the occurrence and abundance of microplastics in bivalves from coastal waters of Paciran, Lamongan, East Java, Indonesia. High population and anthropogenic activities in the area may lead the contamination of microplastics in its marine organisms. Microplastics were recovered from the soft tissues of three species of wild clams, Gafrarium tumidum, Anadara antiquata, and Venerupis philippinarum. In each species, microplastics were grouped based on their types and sizes. The extraction of microplastics was using 30% H2O2, while flotation method using NaCl was used to separate the dissolved liquid of the clam’s soft tissues. Microplastic ingestion was found in 99.23% of the clam samples with average concentration of 3.5 ± 2.8 items/individual and 3.2 ± 2.52 items/g. V. philippinarum had the highest microplastics concentration (4.9 ± 2.80 items/g and 5.6 ± 3.22 items/individual). Microplastic types from all samples were dominated by fibers (80.77%), in which 57% of them were less than 200 µm in size. The ubiquitous contamination of microplastics in clams of the coastal waters of Lamongan, Indonesia is serious concerns for marine food webs and human health.","PeriodicalId":15689,"journal":{"name":"Journal of Engineering and Technological Sciences","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48073690","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 : 2022-09-05DOI: 10.5614/j.eng.technol.sci.2022.54.5.2
A. Al-Luhybi, N. H. Al-Jubory, Anas Ahmed
This study investigated the effect of adding a type of superplasticizer (polycarboxylate ether -PCE) on the workability and mechanical properties of concrete containing recycled coarse aggregate (RCA). The effect of increasing the PCE dosage while changing the water/cement ratio on RCA strength was also studied. To accomplish these goals, three groups of concrete mixtures were prepared. The variable in these groups was the water/cement ratio (0.53, 0.57, and 0.615). In each group, the natural aggregate was replaced by two proportions of RCA (50 and 100%) and different proportions of PCE were added for each replacement ratio. The findings encourage the use of PCE in recycled concrete. It was found that the addition of PCE improves the properties of recycled concrete in terms of workability and compactness. The addition of PCE also compensates for the compressive strength that is lost due to the replacement of natural aggregate with recycled coarse aggregate.
{"title":"Influence of Superplasticizer Dosage on Workability and Mechanical properties of Concrete made with Recycled Aggregate","authors":"A. Al-Luhybi, N. H. Al-Jubory, Anas Ahmed","doi":"10.5614/j.eng.technol.sci.2022.54.5.2","DOIUrl":"https://doi.org/10.5614/j.eng.technol.sci.2022.54.5.2","url":null,"abstract":"This study investigated the effect of adding a type of superplasticizer (polycarboxylate ether -PCE) on the workability and mechanical properties of concrete containing recycled coarse aggregate (RCA). The effect of increasing the PCE dosage while changing the water/cement ratio on RCA strength was also studied. To accomplish these goals, three groups of concrete mixtures were prepared. The variable in these groups was the water/cement ratio (0.53, 0.57, and 0.615). In each group, the natural aggregate was replaced by two proportions of RCA (50 and 100%) and different proportions of PCE were added for each replacement ratio. The findings encourage the use of PCE in recycled concrete. It was found that the addition of PCE improves the properties of recycled concrete in terms of workability and compactness. The addition of PCE also compensates for the compressive strength that is lost due to the replacement of natural aggregate with recycled coarse aggregate.","PeriodicalId":15689,"journal":{"name":"Journal of Engineering and Technological Sciences","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42096521","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 : 2022-09-05DOI: 10.5614/j.eng.technol.sci.2022.54.5.1
Quang Dong Pham, Van-Linh Ngo, The Viet Tran, M. Trinh
This study evaluated the use of the Asaoka and hyperbolic methods to estimate the ultimate settlement of soft ground treated by vacuum preloading combined with prefabricated vertical drains. For this aim, a large-scale physical laboratory model was constructed. The model was a reinforced-tempered glass box containing a soil mass with dimensions of 2.0 × 1.0 × 1.2 m (length × width × depth). Physical models of this scale for the same purpose are rare in the literature. The soil was taken from a typical coastal region in Dinh Vu Hai Phong, Vietnam. The surface settlement near and between the two drains was measured right after the vacuum preloading started. Important properties of the soil were tested to evaluate the effectiveness of the treatment method. The measured settlement was used in the Asaoka and hyperbolic methods to predict the potential ultimate settlement. The results showed the superiority of the vacuum consolidation approach in improving fundamental engineering properties of soft soil. Furthermore, the ultimate settlement predicted by both methods showed a good agreement with the measured value, proving that the Asaoka and hyperbolic methods are suitable for the estimation of the ultimate settlement of soft soil treated with vacuum consolidation.
本研究评估了用Asaoka法和双曲线法来估计真空预压结合预制垂直排水管处理的软土地基的最终沉降。为此，建立了大型物理实验室模型。模型为钢化玻璃强化箱，箱内土体尺寸为2.0 × 1.0 × 1.2 m(长×宽×深)。这种规模的物理模型用于相同的目的在文献中是罕见的。土壤取自越南Dinh Vu Hai Phong的典型沿海地区。在真空预压开始后立即测量了两个排水管附近和排水管之间的地表沉降。对土壤的重要性质进行了测试，以评价处理方法的有效性。实测沉降采用Asaoka法和双曲线法预测潜在的最终沉降。结果表明，真空固结法在改善软土基本工程性质方面具有优越性。两种方法预测的最终沉降值与实测值吻合较好，证明了Asaoka法和双曲法适用于真空固结软土的最终沉降估计。
{"title":"Evaluation of Asaoka and Hyperbolic Methods for Settlement Prediction of Vacuum Preloading Combined with Prefabricated Vertical Drains in Soft Ground Treatment","authors":"Quang Dong Pham, Van-Linh Ngo, The Viet Tran, M. Trinh","doi":"10.5614/j.eng.technol.sci.2022.54.5.1","DOIUrl":"https://doi.org/10.5614/j.eng.technol.sci.2022.54.5.1","url":null,"abstract":"This study evaluated the use of the Asaoka and hyperbolic methods to estimate the ultimate settlement of soft ground treated by vacuum preloading combined with prefabricated vertical drains. For this aim, a large-scale physical laboratory model was constructed. The model was a reinforced-tempered glass box containing a soil mass with dimensions of 2.0 × 1.0 × 1.2 m (length × width × depth). Physical models of this scale for the same purpose are rare in the literature. The soil was taken from a typical coastal region in Dinh Vu Hai Phong, Vietnam. The surface settlement near and between the two drains was measured right after the vacuum preloading started. Important properties of the soil were tested to evaluate the effectiveness of the treatment method. The measured settlement was used in the Asaoka and hyperbolic methods to predict the potential ultimate settlement. The results showed the superiority of the vacuum consolidation approach in improving fundamental engineering properties of soft soil. Furthermore, the ultimate settlement predicted by both methods showed a good agreement with the measured value, proving that the Asaoka and hyperbolic methods are suitable for the estimation of the ultimate settlement of soft soil treated with vacuum consolidation.","PeriodicalId":15689,"journal":{"name":"Journal of Engineering and Technological Sciences","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48119375","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 : 2022-09-05DOI: 10.5614/j.eng.technol.sci.2022.54.5.5
H. Rustamaji, T. Prakoso, H. Devianto, P. Widiatmoko
The supercapacitor has gotten a lot of attention as a high-performance energy storage device because of its high power density, good energy density, long life cycle, and extensive application in various electronic applications. To effectively assess its performance, the electrode material composition was optimized with a blend of activated carbon (AC), multiwall carbon nanotube (MWCNT), and graphene (GR). The synergistic effect of AC, CNT, and GR supports the usage of AC/MWCNT/GR as a viable supercapacitor electrode. Furthermore, the surrounding MWCNT enhances AC and GR electronic conductivity, while AC efficiently suppresses GR re-stacking sheets and aggregates MWCNT particles. For supercapacitor electrodes, the optimal composite mixtures of AC, MWCNT, and GR were 71.7%, 20%, and 8.3% wt, respectively. Meanwhile, an outstanding capacitance value of 33.5 F g-1 in 6 M KOH electrolyte was obtained at 2 mV s-1.
超级电容器由于其功率密度高、能量密度好、寿命周期长，在各种电子应用中得到了广泛的应用，作为一种高性能的储能器件受到了广泛的关注。为了有效评估其性能，将活性炭(AC)、多壁碳纳米管(MWCNT)和石墨烯(GR)混合在一起，对电极材料组成进行了优化。AC、CNT和GR的协同效应支持AC/MWCNT/GR作为可行的超级电容器电极。此外，周围的MWCNT增强了交流和GR的电子导电性，而交流有效地抑制了GR重新堆叠片和MWCNT颗粒的聚集。对于超级电容器电极，AC、MWCNT和GR的最佳复合混合物分别为71.7%、20%和8.3% wt。同时，在6 M KOH电解液中，在2 mV s-1下获得了33.5 F -1的优异电容值。
{"title":"Optimization of Electrode Material Composition from Activated Carbon, MWCNT & Graphene to Enhance Performance of Supercapacitor","authors":"H. Rustamaji, T. Prakoso, H. Devianto, P. Widiatmoko","doi":"10.5614/j.eng.technol.sci.2022.54.5.5","DOIUrl":"https://doi.org/10.5614/j.eng.technol.sci.2022.54.5.5","url":null,"abstract":"The supercapacitor has gotten a lot of attention as a high-performance energy storage device because of its high power density, good energy density, long life cycle, and extensive application in various electronic applications. To effectively assess its performance, the electrode material composition was optimized with a blend of activated carbon (AC), multiwall carbon nanotube (MWCNT), and graphene (GR). The synergistic effect of AC, CNT, and GR supports the usage of AC/MWCNT/GR as a viable supercapacitor electrode. Furthermore, the surrounding MWCNT enhances AC and GR electronic conductivity, while AC efficiently suppresses GR re-stacking sheets and aggregates MWCNT particles. For supercapacitor electrodes, the optimal composite mixtures of AC, MWCNT, and GR were 71.7%, 20%, and 8.3% wt, respectively. Meanwhile, an outstanding capacitance value of 33.5 F g-1 in 6 M KOH electrolyte was obtained at 2 mV s-1.","PeriodicalId":15689,"journal":{"name":"Journal of Engineering and Technological Sciences","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44197484","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 : 2022-09-05DOI: 10.5614/j.eng.technol.sci.2022.54.5.4
Atika Rahmahwati, Aryo Wibowo, F. Rosyid
Indonesia is a leading producer of a wide range of minerals, including copper. Nonetheless, the copper-based industry in Indonesia is still not well developed, especially the limited number of products from the intermediate copper industry which will become raw materials for its downstream industry. The underdeveloped intermediate copper industry has forced Indonesia to import several types of copper-based semi-finished products to meet the needs of the downstream industry. On the other hand, the mining industry still exports copper concentrate and some copper cathodes produced by smelting. As a result, the added value obtained by Indonesia from copper is not optimal. Therefore, it is necessary to conduct research on the copper industry chain and to estimate the increase in added value that could be generated. In this study, a system dynamics (SD) model was developed. During the simulation period of 2020 to 2030, the total added value along the copper industry chain that can be obtained is USD 70,422,840,000 if the planned smelter and refinery is completed in 2023 to process all domestic concentrates and to increase intermediate industry capacity.
{"title":"Analysis of the Copper Industry Chain in Indonesia Using a System Dynamics Approach to Optimize Its Added Value","authors":"Atika Rahmahwati, Aryo Wibowo, F. Rosyid","doi":"10.5614/j.eng.technol.sci.2022.54.5.4","DOIUrl":"https://doi.org/10.5614/j.eng.technol.sci.2022.54.5.4","url":null,"abstract":"Indonesia is a leading producer of a wide range of minerals, including copper. Nonetheless, the copper-based industry in Indonesia is still not well developed, especially the limited number of products from the intermediate copper industry which will become raw materials for its downstream industry. The underdeveloped intermediate copper industry has forced Indonesia to import several types of copper-based semi-finished products to meet the needs of the downstream industry. On the other hand, the mining industry still exports copper concentrate and some copper cathodes produced by smelting. As a result, the added value obtained by Indonesia from copper is not optimal. Therefore, it is necessary to conduct research on the copper industry chain and to estimate the increase in added value that could be generated. In this study, a system dynamics (SD) model was developed. During the simulation period of 2020 to 2030, the total added value along the copper industry chain that can be obtained is USD 70,422,840,000 if the planned smelter and refinery is completed in 2023 to process all domestic concentrates and to increase intermediate industry capacity.","PeriodicalId":15689,"journal":{"name":"Journal of Engineering and Technological Sciences","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43650431","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 : 2022-09-05DOI: 10.5614/j.eng.technol.sci.2022.54.5.3
F. Ferryanto, A. Mahyuddin, M. Nakashima
This work presents the development of a markerless optical motion capture system of the front-crawl swimming stroke. The system only uses one underwater camera to record swimming motion in the sagittal plane. The participant in this experiment was a swimmer who is active in the university’s swimming club. The recorded images were then segmented to obtain silhouettes of the participant by a Gaussian Mixture Model. One of the swimming images was employed to generate a human body model that consists of 15 segments. The silhouette and model of the participant were subjected to an image matching process. The shape of the body segment was used as the feature in the image matching. The model was transformed to estimate the pose of the participant. The intraclass correlation coefficient between the results of the developed system and references were evaluated. In general, all body segments, except head and trunk, had a correlation coefficient higher than 0.95. Then, dynamics analysis by SWUM was conducted based on the joint angle acquired by the present work. The simulation implied that the developed system was suitable for daily training of athletes and coaches due to its simplicity and accuracy.
{"title":"Markerless Optical Motion Capture System for Asymmetrical Swimming Stroke","authors":"F. Ferryanto, A. Mahyuddin, M. Nakashima","doi":"10.5614/j.eng.technol.sci.2022.54.5.3","DOIUrl":"https://doi.org/10.5614/j.eng.technol.sci.2022.54.5.3","url":null,"abstract":"This work presents the development of a markerless optical motion capture system of the front-crawl swimming stroke. The system only uses one underwater camera to record swimming motion in the sagittal plane. The participant in this experiment was a swimmer who is active in the university’s swimming club. The recorded images were then segmented to obtain silhouettes of the participant by a Gaussian Mixture Model. One of the swimming images was employed to generate a human body model that consists of 15 segments. The silhouette and model of the participant were subjected to an image matching process. The shape of the body segment was used as the feature in the image matching. The model was transformed to estimate the pose of the participant. The intraclass correlation coefficient between the results of the developed system and references were evaluated. In general, all body segments, except head and trunk, had a correlation coefficient higher than 0.95. Then, dynamics analysis by SWUM was conducted based on the joint angle acquired by the present work. The simulation implied that the developed system was suitable for daily training of athletes and coaches due to its simplicity and accuracy.","PeriodicalId":15689,"journal":{"name":"Journal of Engineering and Technological Sciences","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41648723","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 : 2022-07-18DOI: 10.5614/j.eng.technol.sci.2022.54.4.1
C. Chiemchaisri, W. Chiemchaisri, Sujipat Dachsrijan, Chitsuphang Saengam
This study investigated coliform removal from hospital wastewater in a membrane bioreactor (MBR) and disinfection using either chlorine or ozone. A laboratory-scale MBR equipped with a hollow-fiber membrane module was operated with hydraulic retention times varied at 3 and 6 hours. The disinfection of MBR effluent was carried out using either chlorine or ozone with concentrations varied between 1 and 10 mg/l and contact time varied between 1 and 30 min. During 150 days of MBR operation, organic removal efficiencies averaged 96.5% and 97.7% for BOD and 73.6% and 84.1% during its operation at an HRT of 3 and 6 hours respectively. Simultaneously, 6.7 and 6.4 log reduction of total coliforms and 6.2 and 6.1 log reduction of E. coli were achieved under these respective HRT conditions. The use of chlorine for disinfection of MBR effluent could eliminate total coliforms and E. coli completely at >6 and 3 mg/L at 30 min contact time, whereas only >3 and 1 mg/L was required for ozone at the same contact time. There was a significant improvement of disinfection efficacy of solid-free MBR effluent compared to that of activated sludge effluent.
{"title":"Coliform Removal in Membrane Bioreactor and Disinfection during Hospital Wastewater Treatment","authors":"C. Chiemchaisri, W. Chiemchaisri, Sujipat Dachsrijan, Chitsuphang Saengam","doi":"10.5614/j.eng.technol.sci.2022.54.4.1","DOIUrl":"https://doi.org/10.5614/j.eng.technol.sci.2022.54.4.1","url":null,"abstract":"This study investigated coliform removal from hospital wastewater in a membrane bioreactor (MBR) and disinfection using either chlorine or ozone. A laboratory-scale MBR equipped with a hollow-fiber membrane module was operated with hydraulic retention times varied at 3 and 6 hours. The disinfection of MBR effluent was carried out using either chlorine or ozone with concentrations varied between 1 and 10 mg/l and contact time varied between 1 and 30 min. During 150 days of MBR operation, organic removal efficiencies averaged 96.5% and 97.7% for BOD and 73.6% and 84.1% during its operation at an HRT of 3 and 6 hours respectively. Simultaneously, 6.7 and 6.4 log reduction of total coliforms and 6.2 and 6.1 log reduction of E. coli were achieved under these respective HRT conditions. The use of chlorine for disinfection of MBR effluent could eliminate total coliforms and E. coli completely at >6 and 3 mg/L at 30 min contact time, whereas only >3 and 1 mg/L was required for ozone at the same contact time. There was a significant improvement of disinfection efficacy of solid-free MBR effluent compared to that of activated sludge effluent.","PeriodicalId":15689,"journal":{"name":"Journal of Engineering and Technological Sciences","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48933739","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 : 2022-07-18DOI: 10.5614/j.eng.technol.sci.2022.54.4.3
C. Adnel, L. Zuhal
Discretization corrected particle strength exchange (DC PSE) is a particle based spatial differential operator designed to solve meshless continuum mechanics problems. DC PSE is a spatial gradient operator that can discretize a computational domain with randomly distributed particles, provided that each particle has enough neighboring particles. In contrast, conventional methods such as the standard finite difference method require the computational domain to be discretized into a Cartesian grid. In linear elasticity simulations, especially steady state cases, this domain is mostly discretized using mesh-based methods such as finite element. However, while particle methods such as smoothed particle hydrodynamics (SPH) have been widely applied to solve dynamic elasticity problems, they have rarely been used in steady state simulations. In this study, a DC PSE operator was used to solve steady linear elasticity problems in a two-dimensional domain. The result of the DC PSE numerical simulation was compared to numerical results, empirical formula results, and results from conventional commercial finite element software, respectively.
{"title":"Discretization Corrected Particle Strength Exchange for Steady State Linear Elasticity","authors":"C. Adnel, L. Zuhal","doi":"10.5614/j.eng.technol.sci.2022.54.4.3","DOIUrl":"https://doi.org/10.5614/j.eng.technol.sci.2022.54.4.3","url":null,"abstract":"Discretization corrected particle strength exchange (DC PSE) is a particle based spatial differential operator designed to solve meshless continuum mechanics problems. DC PSE is a spatial gradient operator that can discretize a computational domain with randomly distributed particles, provided that each particle has enough neighboring particles. In contrast, conventional methods such as the standard finite difference method require the computational domain to be discretized into a Cartesian grid. In linear elasticity simulations, especially steady state cases, this domain is mostly discretized using mesh-based methods such as finite element. However, while particle methods such as smoothed particle hydrodynamics (SPH) have been widely applied to solve dynamic elasticity problems, they have rarely been used in steady state simulations. In this study, a DC PSE operator was used to solve steady linear elasticity problems in a two-dimensional domain. The result of the DC PSE numerical simulation was compared to numerical results, empirical formula results, and results from conventional commercial finite element software, respectively.","PeriodicalId":15689,"journal":{"name":"Journal of Engineering and Technological Sciences","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42280496","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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