Hari Setiabudi Husni, Ford Lumban Gaol, Suhono Harso Supangkat, Benny Ranti
This paper explores the possibility of digital twin concept implementation framework in Indonesia Digital Government Systems (IDGS) using Information Technology (IT) Governance indicators states in Indonesian Government regulation. The concept of Indonesia Digital Government regulated by Indonesia Presidential Regulation no. 95 year 2018 that define digital government as a governance that adapting to advances of technology information and communication and utilize optimally so it can provide service to citizen in most efficient and effective way. Indonesia government implement IT Governance using regulation publish by the Minister of State Apparatus and Bureaucracy Reform No. 59 year 2020 about monitoring and evaluation of Indonesia Digital Government System. In the regulation, the governance consists of monitoring, which is a systematic assessment process through verification of information on the results of the Self-Assessment to measure the maturity level of implementation and the evaluation, is a process of self-assessment systematically through verification and clarification of information which can be continued with information validation to the results of the Self-Assessment to measure maturity level of digital government system implementation. The concept of exploiting digital twin concept to Governed IT Management is a framework introduce by Geert Poels, Henderik A. Proper and Dominik Bork in 2021. The Digital Twin concept itself already utilize to do such as monitoring data, data analysis, conduct simulation, and enhances performance of assets. The framework will be use as a technology infrastructure reference model that facilitate Digital Twin in conceptual aspect where process of IT governance, organizational IT assets management and IT management processes, connected.
本文利用印尼政府监管中的信息技术(IT)治理指标，探讨了数字孪生概念实施框架在印尼数字政府系统(IDGS)中的可能性。印尼数字政府的概念由印尼总统条例第1号规定。95年2018年将数字政府定义为一种适应技术信息和通信进步并最佳利用其以最高效和有效的方式为公民提供服务的治理。印度尼西亚政府利用国家机器和官僚机构改革部长发布的2020年第59号关于印度尼西亚数字政府系统监测和评估的规定实施IT治理。在该法规中，治理包括监测，即通过对自我评估结果的信息进行验证来衡量实施和评估的成熟度的系统评估过程;是一个系统的自我评估过程，通过对信息的验证和澄清，并对自我评估结果进行信息验证，以衡量数字政府系统实施的成熟度水平。利用数字孪生概念治理IT管理的概念是Geert Poels、Henderik a . Proper和Dominik Bork在2021年提出的一个框架。数字孪生概念本身已经被用于监控数据、数据分析、进行模拟和提高资产性能。该框架将用作技术基础设施参考模型，在概念方面促进数字孪生，其中连接了IT治理过程、组织IT资产管理和IT管理过程。
{"title":"DIGITAL TWIN CONCEPT FOR INDONESIA DIGITAL GOVERNMENT INFORMATION TECHNOLOGY GOVERNANCE","authors":"Hari Setiabudi Husni, Ford Lumban Gaol, Suhono Harso Supangkat, Benny Ranti","doi":"10.56127/ijst.v1i2.146","DOIUrl":"https://doi.org/10.56127/ijst.v1i2.146","url":null,"abstract":"This paper explores the possibility of digital twin concept implementation framework in Indonesia Digital Government Systems (IDGS) using Information Technology (IT) Governance indicators states in Indonesian Government regulation. The concept of Indonesia Digital Government regulated by Indonesia Presidential Regulation no. 95 year 2018 that define digital government as a governance that adapting to advances of technology information and communication and utilize optimally so it can provide service to citizen in most efficient and effective way. Indonesia government implement IT Governance using regulation publish by the Minister of State Apparatus and Bureaucracy Reform No. 59 year 2020 about monitoring and evaluation of Indonesia Digital Government System. In the regulation, the governance consists of monitoring, which is a systematic assessment process through verification of information on the results of the Self-Assessment to measure the maturity level of implementation and the evaluation, is a process of self-assessment systematically through verification and clarification of information which can be continued with information validation to the results of the Self-Assessment to measure maturity level of digital government system implementation. The concept of exploiting digital twin concept to Governed IT Management is a framework introduce by Geert Poels, Henderik A. Proper and Dominik Bork in 2021. The Digital Twin concept itself already utilize to do such as monitoring data, data analysis, conduct simulation, and enhances performance of assets. The framework will be use as a technology infrastructure reference model that facilitate Digital Twin in conceptual aspect where process of IT governance, organizational IT assets management and IT management processes, connected.","PeriodicalId":14145,"journal":{"name":"International journal of engineering science and technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82393925","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 study aims to analyze the quality of the Shopee and Lazada Indonesia websites which have beenmeasured using the Webqual method. To find out in the midst of the COVID-19 outbreak like this, whethermany people are switching to online shopping or are still loyal to shopping directly at the market, and users'trust in making non-cash payments. The research methodology used is a qualitative approach. The sampleused is people from any circle who have made purchases at Shopee or Lazada at least 1 time as many as 100respondents. The data collection instrument used primary data. Primary data was obtained by using aquestionnaire distributed through social media. Analysis of the data used in this study were normality test,multicollinearity test, heteroscedasticity test, multiple linear regression analysis test, f test and t test with thehelp of SPSS version 22. By showing the Asymp value. Sig (2-tailed) shows 0.200. Because the value ofAsymp. Sig (2-tailed) > 0.050 this means that the residual data is normally distributed so that the data can beaccepted. The VIF value of X1 and X2 is less than 10 and the tolerance value is more than 0.10. So, it can beconcluded that in the regression model there is no multicollinearity. The scatterplot graph shows that thepoints spread randomly and are spread both above and below zero on the Y axis, there is no heteroscedasticity.The constant of 10.215 states that if the independent variables, namely website quality and trust, areconsidered constant. H1 is accepted, namely the quality of the website has a significant positive effect onuser satisfaction, this can be seen in the significance value of 0.003 or p value <0.05.
{"title":"ANALYSIS OF THE EFFECT OF WEBSITE SERVICE QUALITY AND TRUST ON USER SATISFACTION WITH WEBQUAL METHOD IN E-COMMERCE INDONESIA","authors":"Tubagus Achmadi","doi":"10.56127/ijst.v1i2.220","DOIUrl":"https://doi.org/10.56127/ijst.v1i2.220","url":null,"abstract":"This study aims to analyze the quality of the Shopee and Lazada Indonesia websites which have beenmeasured using the Webqual method. To find out in the midst of the COVID-19 outbreak like this, whethermany people are switching to online shopping or are still loyal to shopping directly at the market, and users'trust in making non-cash payments. The research methodology used is a qualitative approach. The sampleused is people from any circle who have made purchases at Shopee or Lazada at least 1 time as many as 100respondents. The data collection instrument used primary data. Primary data was obtained by using aquestionnaire distributed through social media. Analysis of the data used in this study were normality test,multicollinearity test, heteroscedasticity test, multiple linear regression analysis test, f test and t test with thehelp of SPSS version 22. By showing the Asymp value. Sig (2-tailed) shows 0.200. Because the value ofAsymp. Sig (2-tailed) > 0.050 this means that the residual data is normally distributed so that the data can beaccepted. The VIF value of X1 and X2 is less than 10 and the tolerance value is more than 0.10. So, it can beconcluded that in the regression model there is no multicollinearity. The scatterplot graph shows that thepoints spread randomly and are spread both above and below zero on the Y axis, there is no heteroscedasticity.The constant of 10.215 states that if the independent variables, namely website quality and trust, areconsidered constant. H1 is accepted, namely the quality of the website has a significant positive effect onuser satisfaction, this can be seen in the significance value of 0.003 or p value <0.05.","PeriodicalId":14145,"journal":{"name":"International journal of engineering science and technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88165025","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}
Text classification is the process of grouping text into distinct categories. Text classifiers may automatically assess text input and allocate a set of pre-defined tags or categories depending on its content or a pre-trained model using Natural Language Processing (NLP), which actually is a subset of Machine Learning (ML). The notion of text categorization is becoming increasingly essential in enterprises since it helps firms to get ideas from facts and automate company operations, lowering manual labor and expenses. Linguistic Detectors (the technique of determining the language of a given document), Sentiment Analysis (the process of identifying whether a text is favorable or unfavorable about a given subject), Topic Detection (determining the theme or topic of a group of texts), and so on are common applications of text classification in industry. The nature of the dataset is Multi-class and multi-hierarchical, which means that the hierarchies are in multiple levels, each level of hierarchy is multiple class in nature. One of ML’s most successful paradigms is supervised learning from which one can build a generalization model. Hence, a custom model is built, so that the model fits with the problem. Deep learning (DL), part of Artificial Intelligence (AI) , does functions that replicate the human brain's data processing capabilities in order to identify text or artifacts, translate languages, detect voice, draw conclusions and so on. Bidirectional Encoder Representations from Transformers (BERT), a Deep Learning Algorithm performs an extra-ordinary task in NLP text classification and results in high accuracy. Therefore, BERT is combined with the Custom Model developed and compared with the native algorithm to ensure the increase in accuracy rates.
文本分类是将文本分组为不同类别的过程。文本分类器可以自动评估文本输入并根据其内容或使用自然语言处理(NLP)的预训练模型分配一组预定义标签或类别，这实际上是机器学习(ML)的一个子集。文本分类的概念在企业中变得越来越重要，因为它可以帮助公司从事实中获得想法并使公司操作自动化，从而降低体力劳动和费用。语言检测器(确定给定文档的语言的技术)、情感分析(确定文本对给定主题是有利还是不利的过程)、主题检测(确定一组文本的主题或主题)等是文本分类在工业中的常见应用。数据集的本质是多类、多层次的，即层次结构是多层次的，每一层次结构本质上是多类的。机器学习最成功的范例之一是监督学习，人们可以从中构建泛化模型。因此，构建了一个定制模型，以便该模型适合问题。深度学习(DL)是人工智能(AI)的一部分，其功能是复制人类大脑的数据处理能力，以识别文本或人工制品、翻译语言、检测声音、得出结论等。BERT (Bidirectional Encoder Representations from Transformers)是一种深度学习算法，在NLP文本分类中发挥了非凡的作用，具有很高的准确率。因此，BERT与开发的自定义模型相结合，并与本机算法进行比较，以确保准确率的提高。
{"title":"An innovative approach to classify hierarchical remarks with multi-class using BERT and customized naïve bayes classifier","authors":"M. Dhina, S. Sumathi","doi":"10.4314/ijest.v13i4.4","DOIUrl":"https://doi.org/10.4314/ijest.v13i4.4","url":null,"abstract":"Text classification is the process of grouping text into distinct categories. Text classifiers may automatically assess text input and allocate a set of pre-defined tags or categories depending on its content or a pre-trained model using Natural Language Processing (NLP), which actually is a subset of Machine Learning (ML). The notion of text categorization is becoming increasingly essential in enterprises since it helps firms to get ideas from facts and automate company operations, lowering manual labor and expenses. Linguistic Detectors (the technique of determining the language of a given document), Sentiment Analysis (the process of identifying whether a text is favorable or unfavorable about a given subject), Topic Detection (determining the theme or topic of a group of texts), and so on are common applications of text classification in industry. The nature of the dataset is Multi-class and multi-hierarchical, which means that the hierarchies are in multiple levels, each level of hierarchy is multiple class in nature. One of ML’s most successful paradigms is supervised learning from which one can build a generalization model. Hence, a custom model is built, so that the model fits with the problem. Deep learning (DL), part of Artificial Intelligence (AI) , does functions that replicate the human brain's data processing capabilities in order to identify text or artifacts, translate languages, detect voice, draw conclusions and so on. Bidirectional Encoder Representations from Transformers (BERT), a Deep Learning Algorithm performs an extra-ordinary task in NLP text classification and results in high accuracy. Therefore, BERT is combined with the Custom Model developed and compared with the native algorithm to ensure the increase in accuracy rates.","PeriodicalId":14145,"journal":{"name":"International journal of engineering science and technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74154595","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}
Rolling element bearings are broadly used in the rotating machines to support static and dynamic loads. In this research, the advance signal processing techniques are use for processing of bearing fault signals. Experimental validation with genuine vibration signals calculated from bearings with seeded defects on bearing elements. The model-based fault diagnosis method has attempted to diagnose incipient fault detection and classification of bearing with data driven approach. Feature extraction technique has been developed with hybrid signal processing technique based on the band pass filter nature of Empirical mode decomposition (EMD), the resonant frequency bands have owed in specific mono component signals called Intrinsic Mode Functions (IMFs). Synchronized resonant frequency band (SRFB) is obtained on based of orthogonal real wavelet using spectral kurtosis. Biorthogonal 5.5 wavelet, a real wavelet has been selected as a suitable wavelet for WPT based on “Maximum Relative Wavelet Energy” and “Maximum Energy-to-Shannon entropy ratio”. Three, Feature extraction techniques like continuous wavelet transform (CWT), wavelet packet transform (WPT) and modified Hilbert Huang Transforms (HHT) are compared on bases of their classification accuracy with different classification algorithm and filters. Various supervised classifiers have been compared through a common platform of Waikato Environment for Knowledge Analysis (WEKA) and concluded the k- nearest neighbour (KNN) as an effective available classifier for rolling element bearing. Further, asymmetric proximity function based KNN (APF-KNN) has out performs with modified feature selection criteria. Feature extraction through modified HHT and APFKNN has been future as a most effectual fault classification method. For testing any unknown data, simplified method has been demonstrated, which make the proposed data driven approach more realistic, faster and automated.
{"title":"Fault diagnosis of SKF-6205 bearing with modified empirical mode decomposition","authors":"A. Darji, D. Pandya","doi":"10.4314/ijest.v13i4.2","DOIUrl":"https://doi.org/10.4314/ijest.v13i4.2","url":null,"abstract":"Rolling element bearings are broadly used in the rotating machines to support static and dynamic loads. In this research, the advance signal processing techniques are use for processing of bearing fault signals. Experimental validation with genuine vibration signals calculated from bearings with seeded defects on bearing elements. The model-based fault diagnosis method has attempted to diagnose incipient fault detection and classification of bearing with data driven approach. Feature extraction technique has been developed with hybrid signal processing technique based on the band pass filter nature of Empirical mode decomposition (EMD), the resonant frequency bands have owed in specific mono component signals called Intrinsic Mode Functions (IMFs). Synchronized resonant frequency band (SRFB) is obtained on based of orthogonal real wavelet using spectral kurtosis. Biorthogonal 5.5 wavelet, a real wavelet has been selected as a suitable wavelet for WPT based on “Maximum Relative Wavelet Energy” and “Maximum Energy-to-Shannon entropy ratio”. Three, Feature extraction techniques like continuous wavelet transform (CWT), wavelet packet transform (WPT) and modified Hilbert Huang Transforms (HHT) are compared on bases of their classification accuracy with different classification algorithm and filters. Various supervised classifiers have been compared through a common platform of Waikato Environment for Knowledge Analysis (WEKA) and concluded the k- nearest neighbour (KNN) as an effective available classifier for rolling element bearing. Further, asymmetric proximity function based KNN (APF-KNN) has out performs with modified feature selection criteria. Feature extraction through modified HHT and APFKNN has been future as a most effectual fault classification method. For testing any unknown data, simplified method has been demonstrated, which make the proposed data driven approach more realistic, faster and automated. ","PeriodicalId":14145,"journal":{"name":"International journal of engineering science and technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72795798","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}
In the recent past, the importance of geopolymer concrete as an eco-friendly product to replace portland cement concrete is continuously increasing over time. Yet less research effort has been invested in this area compared with some topical issues in civil engineering. Thus, the objective of this article is to analyse the mechanical properties of geopolymer concrete where the cement is replaced by fly ash and ground granulated blast-furnace slag (GGBS). Sodium silicate and sodium hydroxide 8 molarity solution was used. The compressive strength of a cube in an 8 molarity solution was measured for various mixtures (i.e. G50F50 where G and F stand for GGBS and flyash, respectively while the numerical value denotes the cement percentage) and the cement contents (i.e. 0, 10, 20, 30, 40%). The cube specimens are 100mmx100mmx100mm with the ambient curing at 35- 400C. In total, 9 cubes, 3 beams and 3 cylinders are cast at 7days, 14days and 28days while the compressive strengths of different mixes and cubes are calculated. For 28days, beams and cylinders are measured for flexural and tensile strength. The compressive strength at 7,14 and 28 days nearly doubled the target strength by using geopolymer concrete instead of normal concrete. Compressive strength is about 10% higher at 7 and 14days and 20% higher at 28days after replacing 40% of the cement. Flexural strength increased by 50% when 40% of the cement was replaced but split tensile strength only increased by 1%.
{"title":"Mechanical properties of geopolymer concrete with varying cement content using flyash and ground granulated blast furnace slag","authors":"P. Ashveenkumar, M. Preethi, P. Prashanth","doi":"10.4314/ijest.v13i4.7","DOIUrl":"https://doi.org/10.4314/ijest.v13i4.7","url":null,"abstract":"In the recent past, the importance of geopolymer concrete as an eco-friendly product to replace portland cement concrete is continuously increasing over time. Yet less research effort has been invested in this area compared with some topical issues in civil engineering. Thus, the objective of this article is to analyse the mechanical properties of geopolymer concrete where the cement is replaced by fly ash and ground granulated blast-furnace slag (GGBS). Sodium silicate and sodium hydroxide 8 molarity solution was used. The compressive strength of a cube in an 8 molarity solution was measured for various mixtures (i.e. G50F50 where G and F stand for GGBS and flyash, respectively while the numerical value denotes the cement percentage) and the cement contents (i.e. 0, 10, 20, 30, 40%). The cube specimens are 100mmx100mmx100mm with the ambient curing at 35- 400C. In total, 9 cubes, 3 beams and 3 cylinders are cast at 7days, 14days and 28days while the compressive strengths of different mixes and cubes are calculated. For 28days, beams and cylinders are measured for flexural and tensile strength. The compressive strength at 7,14 and 28 days nearly doubled the target strength by using geopolymer concrete instead of normal concrete. Compressive strength is about 10% higher at 7 and 14days and 20% higher at 28days after replacing 40% of the cement. Flexural strength increased by 50% when 40% of the cement was replaced but split tensile strength only increased by 1%.","PeriodicalId":14145,"journal":{"name":"International journal of engineering science and technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78427654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. R. Tavadi, Y. Naik, K. Kumaresan, N. I. Jamadar, C. Rajaravi
Basalt fiber is a low cost materiel obtained from the Basalt rock from earth, and it can be divided into small pieces to form fiber. In this paper dealing with Basalt fiber manufacturing, property of composites and application are reviewed. The results indicate that as compared to glass fibers, carbon fibers and armide fiber, basalt fiber possesses excellent machine driven properties such as wave permeability, electrical properties, non-conductive and insulation properties. BFRP has higher flexural strength and better adhesion as related to CFRP and GFRP. When temperature increases thermal and mechanical properties of BFRP reduces considerable. Due to the above advantages, the addition of Basalt fiber and its composites can be used in sound and sound absorption and thermal insulation application.
{"title":"Basalt fiber and its composite manufacturing and applications: An overview","authors":"A. R. Tavadi, Y. Naik, K. Kumaresan, N. I. Jamadar, C. Rajaravi","doi":"10.4314/ijest.v13i4.6","DOIUrl":"https://doi.org/10.4314/ijest.v13i4.6","url":null,"abstract":"Basalt fiber is a low cost materiel obtained from the Basalt rock from earth, and it can be divided into small pieces to form fiber. In this paper dealing with Basalt fiber manufacturing, property of composites and application are reviewed. The results indicate that as compared to glass fibers, carbon fibers and armide fiber, basalt fiber possesses excellent machine driven properties such as wave permeability, electrical properties, non-conductive and insulation properties. BFRP has higher flexural strength and better adhesion as related to CFRP and GFRP. When temperature increases thermal and mechanical properties of BFRP reduces considerable. Due to the above advantages, the addition of Basalt fiber and its composites can be used in sound and sound absorption and thermal insulation application.","PeriodicalId":14145,"journal":{"name":"International journal of engineering science and technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88794245","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}
Salt from Bahi wetlands is allegedly containing high concentrations of heavy metals since the wetlands are in the proximity of the prospective uranium mining sites. This means Bahi salt could be an important route through which salt consumers are exposed to high concentrations of heavy metals. This study has analysed 50 salt samples of Bahi salt in order to determine the concentrations of both heavy metals and essential elements using the Energy Dispersive X-Ray Fluorescence Spectrometry (EDXRF). Analytical results show that apart from Na and Cl, Bahi salt is composed of several elements including heavy metals such as Cr, Cd, Pb, Th and U. The salt also contains essential elements such as Mg, K, Ca, Mn, Fe, Co, Zn and Br. The mean concentrations of Cr, Cd, Pb, Th and U ranged from 20 - 25μg/g, 3.8 – 8.85 μg/g, 2.29 – 5.8 μg/g, 6.22 – 15.8 μg/g and 6.5 – 9.12 μg/g respectively. All these toxic elements were in higher concentrations than the recommended maximum tolerable limits (MTL). Meanwhile the daily intake rate of essential elements due consumption of Bahi salt leads to the hazard index (HI) greater than 1 for children. This implies that unless purified, Bahi salt may be unsafe for children. Thus, both salt producers and responsible authorities at Bahi wetlands should collaborate to introduce suitable production methods ensuring effective salt purification before it reaches its consumers.
{"title":"Heavy metals and essential elements in table salt extracted from Bahi wetlands in Central Tanzania","authors":"I. Lugendo, John Bugumba","doi":"10.4314/ijest.v13i4.3","DOIUrl":"https://doi.org/10.4314/ijest.v13i4.3","url":null,"abstract":"Salt from Bahi wetlands is allegedly containing high concentrations of heavy metals since the wetlands are in the proximity of the prospective uranium mining sites. This means Bahi salt could be an important route through which salt consumers are exposed to high concentrations of heavy metals. This study has analysed 50 salt samples of Bahi salt in order to determine the concentrations of both heavy metals and essential elements using the Energy Dispersive X-Ray Fluorescence Spectrometry (EDXRF). Analytical results show that apart from Na and Cl, Bahi salt is composed of several elements including heavy metals such as Cr, Cd, Pb, Th and U. The salt also contains essential elements such as Mg, K, Ca, Mn, Fe, Co, Zn and Br. The mean concentrations of Cr, Cd, Pb, Th and U ranged from 20 - 25μg/g, 3.8 – 8.85 μg/g, 2.29 – 5.8 μg/g, 6.22 – 15.8 μg/g and 6.5 – 9.12 μg/g respectively. All these toxic elements were in higher concentrations than the recommended maximum tolerable limits (MTL). Meanwhile the daily intake rate of essential elements due consumption of Bahi salt leads to the hazard index (HI) greater than 1 for children. This implies that unless purified, Bahi salt may be unsafe for children. Thus, both salt producers and responsible authorities at Bahi wetlands should collaborate to introduce suitable production methods ensuring effective salt purification before it reaches its consumers.","PeriodicalId":14145,"journal":{"name":"International journal of engineering science and technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86664303","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 Low Reynolds S1223 airfoil has been modeled and performance has been evaluated numerically through CFD open source OpenFOAM suite. The numerical results have been validated with available experimental data at Re = 2e05 obtained by means of wind-tunnel tests. Results are also reported at Re = 2e04 and Re = 2.06 in terms of lift and coefficients, streamlines, pressure coefficient and velocity distributions, at 3 different AOA. The main original aspect of this numerical research has been the sensitivity analysis of the aerodynamic performance of the S1223 airfoil over a wide range of Reynolds number. In particular, the effects at low Reynolds number 2e04 have been investigated.
{"title":"CFD analysis of the low Reynolds S1223 airfoil","authors":"E. Mollica, A. Timmoneri","doi":"10.4314/ijest.v13i4.5","DOIUrl":"https://doi.org/10.4314/ijest.v13i4.5","url":null,"abstract":"The Low Reynolds S1223 airfoil has been modeled and performance has been evaluated numerically through CFD open source OpenFOAM suite. The numerical results have been validated with available experimental data at Re = 2e05 obtained by means of wind-tunnel tests. Results are also reported at Re = 2e04 and Re = 2.06 in terms of lift and coefficients, streamlines, pressure coefficient and velocity distributions, at 3 different AOA. The main original aspect of this numerical research has been the sensitivity analysis of the aerodynamic performance of the S1223 airfoil over a wide range of Reynolds number. In particular, the effects at low Reynolds number 2e04 have been investigated.","PeriodicalId":14145,"journal":{"name":"International journal of engineering science and technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72656819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
B. Viswanatha, M. Prasanna Kumar, S. Basavarajappa, T. Kiran, S. Kanchiraya
In the present investigation on fabrication and microstructure of aluminium based hybrid composites. A356 based aluminium matrix material with varying reinforcement percentage from 0 to 9 wt. % in steps of 3 wt. % silicon carbide (SiCp) and fixed quantity of 3 wt. % of graphite (Gr) particles were used in fabrication. The specimens were fabricated by stir-cast method. Heat treatment was carried out for the cast specimen at 540oC for 12 hours and further ageing was carried out at 155ºC for 3, 6, 9 and 12 hours durations. The specimen after heat treatment and ageing were quenched in water at 60oC. The prepared specimens (ascast and aged) were examined using optical microscope to know the particle distribution in the matrix. Hardness and tensile were carried out for as-cast and aged specimen. The results were compared with as-cast and aged specimens. There was a significant improvement in hardness and tensile properties due to increase in the weight percentage of SiCp. The specimen A356-9SiCp-3Gr aged at 9 hrs showed improved hardness, and tensile when compared to other tested specimen. The presence of reinforcements (SiCp and Gr) significantly affects the solid state transition kinetics that improves the properties of composites. The presences of reinforcements in the specimens are evident from the electron dispersive spectroscopy (EDS) analysis.
{"title":"Effect of heat treatment and ageing on microstructure for hypoeutectic Al-7Si alloy and hybrid metal matrix composites","authors":"B. Viswanatha, M. Prasanna Kumar, S. Basavarajappa, T. Kiran, S. Kanchiraya","doi":"10.4314/ijest.v13i4.1","DOIUrl":"https://doi.org/10.4314/ijest.v13i4.1","url":null,"abstract":"In the present investigation on fabrication and microstructure of aluminium based hybrid composites. A356 based aluminium matrix material with varying reinforcement percentage from 0 to 9 wt. % in steps of 3 wt. % silicon carbide (SiCp) and fixed quantity of 3 wt. % of graphite (Gr) particles were used in fabrication. The specimens were fabricated by stir-cast method. Heat treatment was carried out for the cast specimen at 540oC for 12 hours and further ageing was carried out at 155ºC for 3, 6, 9 and 12 hours durations. The specimen after heat treatment and ageing were quenched in water at 60oC. The prepared specimens (ascast and aged) were examined using optical microscope to know the particle distribution in the matrix. Hardness and tensile were carried out for as-cast and aged specimen. The results were compared with as-cast and aged specimens. There was a significant improvement in hardness and tensile properties due to increase in the weight percentage of SiCp. The specimen A356-9SiCp-3Gr aged at 9 hrs showed improved hardness, and tensile when compared to other tested specimen. The presence of reinforcements (SiCp and Gr) significantly affects the solid state transition kinetics that improves the properties of composites. The presences of reinforcements in the specimens are evident from the electron dispersive spectroscopy (EDS) analysis. ","PeriodicalId":14145,"journal":{"name":"International journal of engineering science and technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78428471","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}
Injection is manufacturing process for make a product using thermoplastic material, critical part for electric normally should be self-protecting from fire. Flame Retardant (FR) is a type of thermoplastic material that is resistant to fire and can to mixed additive between resin plastic. Application of FR on various types of plastic resins such as polypropylene (PP). This study discusses the analysis of flame retardant for cover electrical using material polypropylene and benzene additive compound. This study shows that PP and benzene can mixed for create FR grade for application injection plastic. In the physical structure this material has a crack after scanning ×10,000. that elongation of material has a different in some temperature, for 30 ◦C elongation of material is 50%, for 60 ◦C elongation material is 60% and for 90◦C elongation about 90%. Heat capacity of material average in 2700J/kg◦C. average of drop time fire in cover electric average is 1,12 second.
{"title":"ANALYSIS OF FLAME RETARDANT FOR COVER ELECTRICAL PLASTIC INJECTIONUSING MATERIAL POLYPROPYLENE","authors":"Muhammad Yusuf Nurfani","doi":"10.56127/ijst.v1i1.136","DOIUrl":"https://doi.org/10.56127/ijst.v1i1.136","url":null,"abstract":"Injection is manufacturing process for make a product using thermoplastic material, critical part for electric normally should be self-protecting from fire. Flame Retardant (FR) is a type of thermoplastic material that is resistant to fire and can to mixed additive between resin plastic. Application of FR on various types of plastic resins such as polypropylene (PP). This study discusses the analysis of flame retardant for cover electrical using material polypropylene and benzene additive compound. This study shows that PP and benzene can mixed for create FR grade for application injection plastic. In the physical structure this material has a crack after scanning ×10,000. that elongation of material has a different in some temperature, for 30 ◦C elongation of material is 50%, for 60 ◦C elongation material is 60% and for 90◦C elongation about 90%. Heat capacity of material average in 2700J/kg◦C. average of drop time fire in cover electric average is 1,12 second.","PeriodicalId":14145,"journal":{"name":"International journal of engineering science and technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80897359","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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