检索结果-内蒙古大学图书馆

Mechanical Properties of Hydraulic Concretes with Partial Replacement of Portland Cement by Pozzolans Obtained from Agro-Industrial Residues: A Review

SSRN

引用

SSRN 2024年

作者： De Jesus Torres-Ortega, Ramon Torres-Sanchez, Diego Luis Lopez-Lara, Teresa Civil Engineering Program University of Cartagena Cartagena de Indias130015 Colombia Department of Civil and Engineering Environmental Engineering Florida International University United States Faculty of Engineering Autonomous University of Queretaro Qro Santiago de Queretaro76010 Mexico

The following article presents an overview of the research conducted on the use of pozzolans obtained from agro-industrial by-products such as rice husk, palm oil husk, and sugarcane bagasse. The improvements these pozzolans provide in the mechanical properties of compressive, flexural, and tensile strength in concretes with percentages of substitution of conventional Portland cement by these materials have been investigated. This situation is mainly due to their high content of amorphous silica that reacts with calcium hydroxide, when the hydration of Portland cement begins, giving rise to the production of calcium silicate hydrate (CSH) gel, with cementitious properties. In this way, an analysis of the chemical properties of these pozzolans is presented based on their basic oxide content, in particular, the amorphous silica they contain and their reactive activity. Thus, the influence of the temperature and grinding processes used to obtain it will be considered, finding that the optimal temperatures for obtaining amorphous silica range between 600°C and 700 °C. On the other hand, the optimal replacement doses to improve the mechanical properties of concretes are between 10% and 20% replacement. © 2024, The Authors. All rights reserved.

关键词： Tensile strength

来源：评论

学校读者我要写书评

暂无评论

The adsorption potential of andisol/zeolite/fly ash as adsorbents on chromium hexavalent removal 6

The adsorption potential of andisol/zeolite/fly ash as adsor...

引用

6th International Conference on Advanced Materials for Better Future, ICAMBF 2021

作者： Mustofa, R.E. Inayati Pranoto Master Program of Environmental Sciences Universitas Sebelas Maret Surakarta57126 Indonesia Chemical Engineering Department Faculty of Engineering Universitas Sebelas Maret Surakarta57126 Indonesia Department of Chemistry Universitas Sebelas Maret Surakarta57126 Indonesia

The study of Andisol/Zeolite/Fly ash (AZF) as adsorbents has been investigated. This research was aimed to study the characteristics of AZF as an adsorbent for Chromium metal ion removal. Andisol soil and zeolite were activated using NaOH solutions. All materials were characterized by Fourier Transform Infrared (FTIR), Surface Area Analyzer (SAA), and Ultraviolet-Visible Spectrometry (UV-Vis). Based on the results, the optimum composition of AZF was obtained at the ratio of andisol/zeolite/fly ash of 2.4/2.4/0.2 (w/w%), with a decrease on Chromium(VI) concentration above 92%. The optimum condition occurred at a pH of 3 and 150 minutes of contact time. The isotherm study showed that Freundlich isotherm was more dominant rather than Langmuir isotherm. © 2022 Published under licence by IOP Publishing Ltd.

关键词： Zeolites

来源：评论

学校读者我要写书评

暂无评论

Design and Analysis of Automatic Fish Dryer Prototype 2nd

Design and Analysis of Automatic Fish Dryer Prototype

引用

2nd International Conference on Experimental and Computational Mechanics in engineering, ICECME 2020

作者： Raynaldo, Kevin Andrianto, Richie Darmawan, Steven Study Program of Mechanical Engineering Faculty of Engineering Universitas Tarumanagara Jalan Letjen S. Parman No. 1 Jakarta Barat11440 Indonesia

ISBN: (纸本)9789811607356

Indonesia has lots of natural resources especially in marine sector such as yellowstripe scad and long-jawed mackerel. Those fish are usually dried by fisherman for longer storage using conventional drying by heat from the sun. This conventional drying method takes hours, about two or three days depends on sun heat intensity. Based on that problem, mechanical drying system may overcome the problem. Automatic fish dryer is designed to dry the fish effectively with even heat distribution with palette rotation system which is hoped to increase productivity and economic potential for coastal communities. The prototype is designed theoretically with mechanical design to generate part specification including heater, shaft, electric motor, bearing, pulley and transmission. CFD method to discover the heat distribution inside with 5,239 nodes and STD k-Ε turbulence model. A 400 mm × 500 mm × 420 mm prototype is generated to dry 2 kg of long-jawed mackerels in 5.3 h with 0.00419 g/s for drying mass flow rate from 70 to 30% water content. CFD simulation shows the exhaust fan need to be installed at outlet for better water-vapor flow distribution. This research indicates that automatic fish dryer can dry 4 times faster than conventional drying system. © 2021, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： CFD Fish dryer Mechanical design Prototype

来源：评论

学校读者我要写书评

暂无评论

The Effect of Filter Media Size and Loading Rate to Filter Performance of Removing Microplastics using Rapid Sand Filter

引用

Journal of engineering and Technological Sciences 2022年第5期54卷

作者： Fajar, Mutiara Sembiring, Emenda Handajani, Marisa Environmental Engineering Study Program Faculty of Civil and Environmental Engineering Institut Teknologi Bandung Jalan Ganesha No. 10 Bandung40132 Indonesia Environmental Engineering Department Institut Teknologi Sumatera Jalan Terusan Ryacudu Way Huwi Kec. Jati Agung South Lampung 35365 Indonesia

Microplastics (MP) can pose a serious threat to the environment and human health because of their tiny size and ability to spread easily in water. One of the alternative treatments to remove MP from water is the rapid sand filter (RSF). The objective of this study was to analyze the effects of filter media size and loading rate on RSF performance in removing MP. The applied filter media was silica sand with effective sizes (ES) of 0.39 and 0.68 mm. The loading rates of filtration were 4;6;8 and 10 m3/m2-h. The MP samples were made from plastic bags and torn tires (artificial samples: 10 to 800 µm). This study showed that the MP removal percentage was up to 96.6% (MP size larger than 200 µm). The head loss increment for loading rates 4;6;8;10 m3 /m2-h was 0.16;0.35;0.34;0.25 m (ES 0.39 m) and 0.10;0.18;0.18;0.19 m (ES 0.68 m)), respectively. Meanwhile, the filtration cycle for loading rates 4;6;8;and 10 m3/m2-h was 5, 2, 2, and 1 days (ES 0.39 mm) and 9, 4, 3, and 3 days (ES 0.68 mm), respectively. The result of this study showed that the smaller the filter media size, the higher the head loss of the filter media bed. Furthermore, there is an increased head loss of the filter media bed when the loading rate is greater. © 2022 Published by ITB Institute for Research and Community Services,.

关键词： Microplastic

来源：评论

学校读者我要写书评

暂无评论

Biogas production and its utilization in internal combustion engines - A review

引用

Process Safety and environmental Protection 2024年 186卷 518-539页

作者： Vasan, Vinod Sridharan, Naveen Venkatesh Feroskhan, M. Vaithiyanathan, Sugumaran Subramanian, Balaji Tsai, Pei-Chien Lin, Yuan-Chung Lay, Chyi-How Wang, Chin-Tsan Ponnusamy, Vinoth Kumar Vellore Institute of Technology Chennai600127 India Department of Mechanical Engineering Faculty of Engineering and Technology SRM Institute of Science and Technology Kattankulathur Chennai603203 India Kaohsiung City807 Taiwan Department of Computational Biology Institute of Bioinformatics Saveetha School of Engineering Saveetha Institute of Medical and Technical Sciences Tamil Nadu Chennai602105 India Institute of Environmental Engineering National Sun Yat-sen University Kaohsiung804 Taiwan Center for Emerging Contaminants Research National Sun Yat-sen University Kaohsiung804 Taiwan Master's Program of Green Energy Science and Technology Feng Chia University Taichung City407102 Taiwan Department of Mechanical and Electro-Mechanical Engineering National I-Lan University I Lan Taiwan Research Center for Precision Environmental Medicine Kaohsiung Medical University Kaohsiung City807 Taiwan Kaohsiung City807 Taiwan Division of Operation and Maintenance Engineering Luleå University of Technology Luleå Sweden Department of Chemistry National Sun Yat-sen University Kaohsiung804 Taiwan

This review presents the significance and current challenges associated with fossil fuels, highlighting the need for cleaner and more sustainable energy sources. The significant object of the current study is to concentrate on increased interest in utilizing biogas as a viable substitute for traditional fuels, delving into its characteristics, benefits, accessibility, feasibility, and prospects as an environmentally sustainable energy option. The current study extensively analyses the prospect and significance of biogas in mitigating emissions regulations in Internal Combustion Engines (ICEs). This paper provides a comprehensive overview of recent research on incorporating biogas in internal combustion engines, focusing on emission reduction and the corresponding impact on engine performance. The subject matter encompasses a range of facets about biogas, encompassing its origins, chemical composition, purification, enhancement techniques, and requisite engine adjustments to enable the effective utilization of biogas as an alternative fuel. The study also evaluates the performance of biogas-fuelled ICEs based on the results of cross-referencing with contemporary research and investigates peripheral aspects such as additive inclusion to increase biogas capabilities as fuel and potential applications in advanced engine modes of operation. The review identifies research gaps in the domains of biogas processing and utilization in ICEs and acknowledges existing challenges specific to the adoption of biogas as a conventional fuel alternative. Future research directions are also prescribed, further highlighting the importance of transitioning from fossil fuels to meet environmental goals and global energy demands. © 2024 The Institution of Chemical Engineers

关键词： Biogas

来源：评论

学校读者我要写书评

暂无评论

Implementation of AI-Based Support Vector Machine Algorithm for Fraud Detection in Digital Payment Systems

Implementation of AI-Based Support Vector Machine Algorithm ...

引用

International Seminar on Research of Information Technology and Intelligent Systems (ISRITI)

作者： Edy Prayitno Rikie Kartadie Uning Lestari Munengsih Sari Bunga Accounting Information Systems Faculty of Information Technology Universitas Teknologi Digital Indonesia Yogyakarta Indonesia Computer Engineering Study Program Faculty of Information Technology Universitas Teknologi Digital Indonesia Yogyakarta Indonesia Informatics Study Program Faculty of Science and Information Technology Universitas Akprind Indonesia Yogyakarta Indonesia Department of Computer Engineering Smart City Information Systems Politeknik Negeri Indramayu Indramayu Indonesia

ISBN: (数字)9798331519643

ISBN: (纸本)9798331519650

The increasing use of digital payment systems has led to a rise in fraudulent activities, presenting a significant challenge in ensuring secure transactions. This research focuses on implementing the Support Vector Machine (SVM) algorithm with a Radial Basis Function (RBF) kernel to detect fraud in digital payment systems. One of the main challenges addressed in this study is the severe class imbalance in the dataset, where fraudulent transactions account for only 0.17% of total transactions. To overcome this, the SMOTE (Synthetic Minority Over-sampling Technique) method was applied to balance the dataset, allowing the model to better recognize fraudulent patterns. The results indicate that the SVM model achieved an accuracy of 99.93%, with a precision of 86.23% and a recall of 75.51%. These results demonstrate that SVM, combined with SMOTE and RBF kernel, is highly effective in detecting fraudulent transactions while minimizing false positives. This research provides a strong foundation for improving fraud detection models in the context of digital payment systems, offering enhanced security and trust for users. Further research could explore hybrid models and real-time data analysis to improve performance.

关键词： Support vector machines Seminars Adaptation models Accuracy Data models Real-time systems Fraud Security Kernel Intelligent systems

来源：评论

学校读者我要写书评

暂无评论

Enhancing Search Efficiency: Analyzing Learning Mechanisms in Metaheuristics

Enhancing Search Efficiency: Analyzing Learning Mechanisms i...

引用

Information Technology and Computing (ICITCOM), International Conference on

作者： Teddy Nurcahyadi Christian Blum Mechanical Engineering Study Program Engineering Faculty Universitas Muhammadiyah Yogyakarta Yogyakarta Indonesia Consejo Superior de Investigaciones Científicas Institut d'Investigació en Inielligència Artificial Barcelona Spain

ISBN: (数字)9798350379839

ISBN: (纸本)9798350379846

Metaheuristics have evolved significantly in the last few decades. Nowadays, more complex problems and essential applications are emerging, requiring more powerful metaheuristics to handle them. This article analyzes the characteristics and performance of existing metaheuristics, with particular emphasis on their learning mechanisms. Several critical aspects for improvement are identified, and several promising future research areas are recommended.

关键词： Learning systems Metaheuristics Memory Benchmark testing Maintenance Information technology Standards Faces

来源：评论

学校读者我要写书评

暂无评论

Self-loop Laplacian Formation Control for Linear Systems

Self-loop Laplacian Formation Control for Linear Systems

引用

Computer Sciences, engineering, and Technology Innovation (ICoCSETI), International Conference on

作者： Ashton Bradley Hendrawan Djati Wibowo Djamari Ignatius Pulung Nurprasetio Harry Septanto Mechanical Engineering Study Program Sampoerna University Jakarta Indonesia Faculty of Mechanical and Aerospace Engineering Institut Teknologi Bandung Bandung Indonesia Research Center for Smart Mechatronics National Agency for Research and Innovation (BRIN) Bogor Indonesia

ISBN: (数字)9798331508616

ISBN: (纸本)9798331508623

This study works on scalable formation control of general linear system agents which based on self-loop Laplacian method. Self-loop Laplacian method for scalable formation is used when it is desired that the initial states of agents and communication topology of agents affects the formation size directly. Proof is provided demonstrating that the self-loop Laplacian matrix shares spectral properties with the standard Laplacian matrix, and the two can be related through a transformation matrix. Existing works on scalable formation mostly focused on single and double integrator agents, particularly where the control input algorithm uses self-loop Laplacian matrix. Extending the work on self-loop Laplacian matrix, this study proposes a control input algorithm for agents in linear system dynamics. The algorithm uses both self-loop Laplacian formulation and general linear system consensus methods, and the stability of the whole system is proven using Lyapunov direct method. Two numerical examples with 4 and 5 agents are shown to verify the result.

关键词： Linear systems Technological innovation Laplace equations Heuristic algorithms Formation control Topology Collision avoidance Standards Numerical stability Multi-agent systems

来源：评论

学校读者我要写书评

暂无评论

Development of a cyclone separator for particulate matter control in fique bag production: A case study at Empaques del Cauca S.A.

引用

Case Studies in Chemical and environmental engineering 2024年 10卷

作者： Gutierrez, Johana Astudillo Guerrero Narvaez, Jhon Alexander Campo Ceballos, Diego Andres Muñoz Chaves, Javier Andres Environmental Engineering Program Faculty of Engineering Universidad Del Cauca Popayán 190003 Colombia Faculty of Engineering Intelligent System Research Group Corporación Universitaria Comfacauca-Unicomfacauca Popayán 190003 Colombia

environmental pollution has become a pressing global concern that poses significant health risks and socioeconomic challenges. Developing countries are witnessing increased chronic diseases attributed to water and air pollution. This study focuses on Empaques del Cauca S.A., a Colombian company that manufactures fique bags for domestic and international markets. Due to the existing technological and technical infrastructure, the production process of these bags generates the emission of particulate material, specifically PM10 and PM2.5. Thus, developing a cyclone separator is proposed, following the V-quadrant methodology, incorporating the requirements of problem recognition and integrating it into design and simulation stages through computer-aided design and engineering. In this way, the results of the design and simulation of the Stairmand-type cyclone separator demonstrate the fulfillment of the functional, technical, and operational requirements established by the problem of the case study company. The cyclone separator achieved an 88 % average separation efficiency for particles between 1 and 10 μm. In addition, static studies on displacement and stress in the critical component of the outlet pipe indicate the optimum performance of stainless steel as a construction material, outperforming black steel plate. Stainless steel not only has minimal static displacement but also has maximum stress tolerance and operating speed limits. The materials proposed for the cyclone separators show commendable performance, especially for 10 μm particulate material (PM10). Both materials effectively eject zero particles per second into the air and collect the particles in the collector condenser with variable velocity profiles. In the case of the stainless-steel design, a marginal increase in particle collection is observed at specific velocity profiles, highlighting its overall efficiency. This research not only presents a satisfactory solution to reduce particulate emission

关键词： CAD/CAE simulation Cyclone separator Fique bags Particulate matter Separation efficiency

来源：评论

学校读者我要写书评

暂无评论

Improvement of PID Based on Fuzzy Logic Controller for Controlling Attitude of a Quadcopter

Improvement of PID Based on Fuzzy Logic Controller for Contr...

引用

Aerospace Electrical engineering and Informatics (ICAAEEI), International Conference of Adisutjipto on

作者： Ernando Rizki Dalimunthe Horas Nico L. P. Sibuea Dirga Rama Setiadi Akhmad Jayadi Jaka Persada Sembiring Elka Pranita Faculty of Engineering and Computer Science Universitas Teknokrat Indonesia Bandar Lampung Indonesia Informatic Management Study Program Politenik Negeri Lampung Bandar Lampung Indonesia

ISBN: (数字)9798331507930

ISBN: (纸本)9798331507947

The quadcopter has a fairly simple mechanical design because it does not require other drives to perform various movements such as roll, pitch, and yaw. The simplicity of this mechanical design has a considerable impact on the complexity of its control. Therefore, it is necessary to have a good control method to maintain the stability of the quadcopter. The research aims to maintain stability of quadcopter by using a combination of the Fuzzy Logic Controller (FLC) with the Proportional-Integral-Derivative (PID) method, where FLC is used to initialize the input of the PID method to find the quadcopter stability point. The application of fuzzy methods for the initial tuning of PID parameters has proven effective in enhancing the system's fundamental performance, such as overshoot, rise time, and settling time, compared to the conventional PID approach. The proposed method can reduce overshoot by over 20%, with reductions reaching up to 88% in yaw motion. Additionally, the Fuzzy-PID approach significantly improves stability, shortening the time to achieve steady-state by less than 1 seconds for all movements while PID did more than 2s for pitch and roll motions and over 1s for yaw motion.

关键词： Fuzzy logic Power demand PI control Attitude control Stability analysis Regulation Steady-state PD control Tuning Quadrotors

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：