Makara Journal of Technology最新文献_第4页

Effects of Plasma Sintering on the Post TIG Weld Joint of Fe-15Cr-25Ni Austenitic Stainless Steel 等离子烧结对Fe-15Cr-25Ni奥氏体不锈钢TIG焊后焊缝的影响

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Makara Journal of Technology Pub Date : 2022-04-30 DOI: 10.7454/mst.v26i1.1577

引用次数: 0

Enhancement of Biogas Production Through Solid-State Anaerobic Co-Digestion of Food Waste and Corn Cobs 通过食物垃圾和玉米芯的固态厌氧共消化提高沼气产量

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Makara Journal of Technology Pub Date : 2022-04-30 DOI: 10.7454/mst.v26i1.1478

引用次数: 1

Control Strategy for Solar Energy-Saving Lamps for Optimized Energy Utilization and Sustainability of Operation Durability: Indonesia Case 太阳能节能灯优化能源利用和运行耐久性的控制策略:印尼案例

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Makara Journal of Technology Pub Date : 2022-04-30 DOI: 10.7454/mst.v26i1.1474

引用次数: 0

Comparative Study of Rankine Cycle Power Generation using Water and Organic Fluids in Saturated and Superheated States 水和有机流体在饱和和过热状态下朗肯循环发电的比较研究

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Makara Journal of Technology Pub Date : 2021-12-30 DOI: 10.7454/mst.v25i3.3942

G. Pikra, Henny Sudibyo

{"title":"Comparative Study of Rankine Cycle Power Generation using Water and Organic Fluids in Saturated and Superheated States","authors":"G. Pikra, Henny Sudibyo","doi":"10.7454/mst.v25i3.3942","DOIUrl":"https://doi.org/10.7454/mst.v25i3.3942","url":null,"abstract":"The Rankine cycle is an electricity generation system that uses water or organic fluids as high-grade or low-grade heat sources, respectively. In this paper, we present the results of our study of Rankine-cycle power generation in which we compared water and organic fluids (toluene and n-nonane) as working fluids in saturated and superheated states. We analyzed the energy and exergy of the Rankine cycle in a saturated vapor state at 300 °C and superheated states at 400 °C and 500 °C (the pressure remained the same as that at 300 °C), and assumed a constant heat input for all states. In the energy analysis, we determined the mass flow rate, heat rejection, work input of the pump, work generated by the turbine, net work output, and thermal efficiency. In the exergy analysis, we determined the exergy input, exergy loss, exergy destruction at the pump and the turbine, and the exergetic efficiency. The results show that water, categorized as a wet fluid, obtains a better performance with respect to both analyses in saturated and superheated states than toluene and nnonane, which are categorized as isentropic and dry fluids, respectively. The water realizes a higher performance in the superheated than in the saturated state, whereas the performances of toluene and n-nonane are poorer in the superheated than in the saturated state.","PeriodicalId":42980,"journal":{"name":"Makara Journal of Technology","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48496167","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}

引用次数: 0

Identification of Thermophilic Bacteria from Tirta Lebak Buana Hot Spring in Serang, Banten, Indonesia 印度尼西亚万丹市雪朗市Tirta Lebak Buana温泉中嗜热细菌的鉴定

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Makara Journal of Technology Pub Date : 2021-12-30 DOI: 10.7454/mst.v25i3.3993

Kenny Lischer

{"title":"Identification of Thermophilic Bacteria from Tirta Lebak Buana Hot Spring in Serang, Banten, Indonesia","authors":"Kenny Lischer","doi":"10.7454/mst.v25i3.3993","DOIUrl":"https://doi.org/10.7454/mst.v25i3.3993","url":null,"abstract":"Since Taq polymerase was first explored and identified from thermophilic bacteria, these bacteria have become wellknown sources of thermostable enzymes. New thermophilic bacteria have been investigated to broaden biodiversity and translation research. Studies have shown interests in Indonesia because of thermophilic bacteria found in hot springs. This country is traversed by the ring of fire and has more than 70 volcanoes, resulting in the wide distribution of hot springs across the country. Although many reports have been performed, studies have yet to explore thermophilic bacteria in Tirta Lebak Buana hot springs, Java Island, Indonesia. This research was the first to examine thermophilic bacteria in Tirta Lebak Buana hot spring. Two samples from two different sampling sites were obtained and analyzed through 16srRNA analysis (sampling sites A and B). Measurements indicated that the temperature (50 °C) in sampling site A was higher than that in sampling site B (40 °C), but they had similar pH (7.0). Polymerase chain reaction (PCR) showed that the 16srRNA of the specimen was around 1465 bp. The analysis of the 16srRNA sequence revealed that the obtained bacteria have a similar sequence and close relationship with Bacillus subtilis subsp. stercoris strain N12.","PeriodicalId":42980,"journal":{"name":"Makara Journal of Technology","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46201554","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}

引用次数: 0

Assessing the E-learning Readiness of Universities in Developing Countries and Expected Obstacles 评估发展中国家大学的电子学习准备情况及预期障碍

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Makara Journal of Technology Pub Date : 2021-12-30 DOI: 10.7454/mst.v25i3.4047

A. Ate, Samar Zaineldeenc, Cai Zhaohui, Yan Zhao

{"title":"Assessing the E-learning Readiness of Universities in Developing Countries and Expected Obstacles","authors":"A. Ate, Samar Zaineldeenc, Cai Zhaohui, Yan Zhao","doi":"10.7454/mst.v25i3.4047","DOIUrl":"https://doi.org/10.7454/mst.v25i3.4047","url":null,"abstract":"To benefit from electronic learning (E-learning), organizations should execute considerable upfront analysis to ascertain their E-learning readiness. Studies have demonstrated a range of models that have been adapted, but they are used in developed counties for whom E-learning readiness is elevated. Thus, these models are not valid in growing countries, such as Sudan. Based on a modified model, this research was performed descriptively by applying a questionnaire-based survey method to assess the level of Sudan universities’ readiness in the employment of the E-learning system. This modified model includes social support, technology readiness, attitude toward E-learning, acceptance of E-learning, and individual learners. Furthermore, the adoption and implementation of E-learning involve numerous challenges and constraints. Therefore, in this study, the challenges that could be faced in applying E-learning in Sudan from students’ perspectives are investigated. The results show that the most prepared factor is individual learners at Sudanese universities. However, this factor still needs a few improvements for E-learning with an overall mean (3.59). Given that the learners are willing to collaborate and share information and knowledge, they can manage time for their learning, and they are also motivated and enthusiastic about using computers. Moreover, attitude toward E-learning is the least prepared factor among all factors (mean = 3.16), which means that this factor is not ready and needs some work. The study recognizes serious barriers that constrain the effective incorporation of E-learning in higher education institutes (HEIs) in developing countries.","PeriodicalId":42980,"journal":{"name":"Makara Journal of Technology","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46990866","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}

引用次数: 3

Behavior of High-plasticity Clay Stabilized with Lime and Rice Husk Ash 石灰和稻壳灰稳定高塑性粘土的行为

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Makara Journal of Technology Pub Date : 2021-12-30 DOI: 10.7454/mst.v25i3.3580

F. Fatnanta, Andarsin Ongko, Adnan Ihsan

引用次数: 2

Modeling and Optimization of Spinning Parameters on Selectivity of Polysulfone Hollow Fiber Membrane for CO2/CH4 Separation 聚砜中空纤维膜分离CO2/CH4选择性的纺丝参数建模与优化

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Makara Journal of Technology Pub Date : 2021-12-30 DOI: 10.7454/mst.v25i3.3865

Shahab Khademi, I. Darus, M. Mailah, L. W. Jye, A. Khademi

{"title":"Modeling and Optimization of Spinning Parameters on Selectivity of Polysulfone Hollow Fiber Membrane for CO2/CH4 Separation","authors":"Shahab Khademi, I. Darus, M. Mailah, L. W. Jye, A. Khademi","doi":"10.7454/mst.v25i3.3865","DOIUrl":"https://doi.org/10.7454/mst.v25i3.3865","url":null,"abstract":"Hollow fiber membrane (HFM) and related technologies have recently become highly in demand and widely used in most industries and other areas recently. HFM could be used in different functions, from water and gas treatment to blood and medical applications. The paper describes the modeling of the effects of the spinning condition of a nonporous HFM on the membrane’s characteristics with the use of an automated hollow fiber fabrication system. An integrated, systematic experimental strategy based on the design of experiments was used to elaborate the effects of each parameter on selectivity. To obtain and sustain a satisfactory, significant selectivity of HFM, an automated system controlled the parameters during the fabrication process. The parameters involved in the fabrication of HFM and used in modeling are dope flow rate, bore flow rate, draw force, and air gap, which are considered inputs to fabricate polysulfone membrane. The fabrication process is improved by automating and instrumenting fabrication systems. An empirical model of the effects of fabrication parameters on the selectivity of the membrane is extracted experimentally. The mathematical model effectively explains the selectivity of CO2/CH4 with 95% fit.","PeriodicalId":42980,"journal":{"name":"Makara Journal of Technology","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45980300","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}

引用次数: 0

Development of A 2D Numerical Model for Pollutant Transport using FTCS Scheme and Numerical Filter 基于FTCS格式和数值滤波器的污染物传输二维数值模型的开发

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Makara Journal of Technology Pub Date : 2021-12-30 DOI: 10.7454/mst.v25i3.3966

Ravena Maitsa, Q. Hafiyyan, M. Adityawan, I. Magdalena, A. A. Kuntoro, H. Kardhana

引用次数: 1

Economic Design, Fabrication, and Performance Evaluation of Conventional Ovens Made of Glass-Fiber-Reinforced Thermoset Composites 玻璃纤维增强热固性复合材料常规烘箱的经济设计、制造和性能评价

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Makara Journal of Technology Pub Date : 2021-12-30 DOI: 10.7454/mst.v25i3.3853

C. Agbo

{"title":"Economic Design, Fabrication, and Performance Evaluation of Conventional Ovens Made of Glass-Fiber-Reinforced Thermoset Composites","authors":"C. Agbo","doi":"10.7454/mst.v25i3.3853","DOIUrl":"https://doi.org/10.7454/mst.v25i3.3853","url":null,"abstract":"This study focuses on the development of a conventional oven using glass-fiber-reinforced thermoset composite sandwich panels. The design process considers the thermomechanical properties of the selected materials. The constructed rectangular box oven has the overall dimensions of 450 mm × 450 mm × 600 mm and internal heat chamber dimensions of 400 mm width, 400 mm depth, and 400 mm height with two stack trays for product placement. The sidewalls consist of inner and outer E-glass-fiber-reinforced composite panels with a sandwiched rockwool insulator. The bottom panel of the oven has an inner ceramic tile plate to suspend the electric heating element. The top panel is made of the same composite sandwich with a constructed superstructure electrical wiring compartment included for the controls. The oven can stably achieve a temperature of 150 °C and a cooking efficiency of approximately 39% when in operation and can sustain heat for more than 6 h standing time when turned off. The oven can be used for both culinary and laboratory experiments, i.e., heating, baking, drying, and curing materials, and is more affordable than alternative designs in the market.","PeriodicalId":42980,"journal":{"name":"Makara Journal of Technology","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45144246","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}

引用次数: 0