English-Chinese Abstract Collection
Abstract of Teknomekanik
English–Chinese Abstract Collection
Explore article abstracts published in Teknomekanik since 2024, presented in English and Chinese, with selected articles available in additional international languages.
Comparison of MCDM methods effectiveness in the selection of plastic injection molding machines
塑料注塑机选型中MCDM方法有效性的比较
Do Duc Trung, School of Mechanical and Automotive Engineering, Hanoi University of Industry, Hanoi, Vietnam
Branislav Dudić, Comenius University Bratislava, Faculty of Management, Slovakia
Duong Van Duc, School of Mechanical and Automotive Engineering, Hanoi University of Industry, Hanoi, Vietnam
Nguyen Hoai Son, School of Mechanical and Automotive Engineering, Hanoi University of Industry, Hanoi, Vietnam
Aleksandar Ašonja, Faculty of Economics and Engineering Management, Novi Sad, Serbia
DOI: https://doi.org/10.24036/teknomekanik.v7i1.29272
Abstract
In each specific problem of finding the best solution among many available options, where each option has multiple criteria, multi criteria decision making methods are considered equally effective when they converge to the same optimal solution. Proximity Indexed Value, Preference Selection Index, Faire Un Choix Adéquat (in French), and Collaborative Unbiased Rank List Integration are four Multi Criteria Decision Making methods with very different characteristics. All these four methods have been used a lot in recent times. The effectiveness of these four methods have been confirmed to be comparable to other multi criteria decision making methods in many applications. However, the comparison of these four methods with each other has never been performed in any studies. This article is performed to fill that gap. These four methods have been used to find to the best option among five types of plastic injection molding machine. Ten criteria have been chosen to describe each alternative. Two different methods that have been used to calculate the weights for the criteria are the MEAN weight method and the CRiteria Importance Through Intercriteria Correlation weight method. Different scenarios have been created to compare the effectiveness of these four methods. The results have shown that the four multi criteria decision making methods mentioned above are equally effective in the selection of plastic injection molding machines. Among the five types of plastic injection molding machines, namely JSW J350EII-SPA ANBE-002-02, Meiki M-200B-SJ, Meiki M-350C-DF-SJ, JSW J350E II, and JSW J550E-C5, the JSW J550E-C5 is the best type.
摘要
对于每一个需要在多个可选方案中寻找最佳解决方案的具体问题，当每个方案均具有多个评价准则时，如果不同的多准则决策方法最终得到相同的最优解，则可认为这些方法具有同等的有效性。Proximity Indexed Value、Preference Selection Index、Faire Un Choix Adéquat（法语）和Collaborative Unbiased Rank List Integration是四种具有显著不同特征的多准则决策方法。近年来，这四种方法均得到了广泛应用。在许多应用中，这四种方法的有效性已被证实与其他多准则决策方法具有可比性。然而，迄今为止，尚未有研究对这四种方法彼此之间的有效性进行比较。本文旨在填补这一研究空白。研究采用这四种方法，从五种塑料注塑机中选出最佳方案。选取十项准则对每个备选方案进行描述。用于计算各准则权重的两种不同方法分别为MEAN权重法和CRiteria Importance Through Intercriteria Correlation权重法。研究设置了不同情景，以比较这四种方法的有效性。结果表明，上述四种多准则决策方法在塑料注塑机选型中具有同等的有效性。在五种塑料注塑机，即JSW J350EII-SPA ANBE-002-02、Meiki M-200B-SJ、Meiki M-350C-DF-SJ、JSW J350E II和JSW J550E-C5中，JSW J550E-C5为最佳机型。
Keywords: MCDM, PIV method, PSI method, FUCA method, CURLI method
关键词： MCDM；PIV方法；PSI方法；FUCA方法；CURLI方法
How to Cite: Trung, D. D., Dudić, B., Duc, D. V., Son, N. H., & Ašonja, A. (2024). Comparison of MCDM methods effectiveness in the selection of plastic injection molding machines. Teknomekanik, 7(1), 1–19. https://doi.org/10.24036/teknomekanik.v7i1.29272
Enhancing mechanical properties of polylactic acid through the incorporation of cellulose nanocrystals for engineering plastic applications
通过添加纤维素纳米晶体增强聚乳酸的力学性能及其在工程塑料中的应用
Shih-Chen Shi, Department of Mechanical Engineering, National Cheng Kung University, Taiwan
Chia-Feng Hsieh, Department of Mechanical Engineering, National Cheng Kung University, Taiwan
Dieter Rahmadiawan, Department of Mechanical Engineering, Universitas Negeri Padang, Indonesia
DOI: https://doi.org/10.24036/teknomekanik.v7i1.30072
Abstract
This study investigates the potential of enhancing the mechanical properties of polylactic acid (PLA) using cellulose nanocrystals (CNC). Recognized for their high specific strength and stiffness, CNCs are considered to improve the performance of PLA in engineering plastic applications. The synthesis involves a twin-screw extrusion process, which facilitates the uniform dispersion of CNC within the PLA matrix. The mechanical properties, including tensile strength and elongation at break, are comprehensively analyzed, highlighting the effects of CNC concentrations on the performance of PLA composites. Notably, the addition of 1 wt% CNC resulted in a 20% increase in strain at break compared to pure PLA, demonstrating enhanced ductility. Additionally, the thermal resistance of the composite increased by 0.3% with the inclusion of 5 wt% CNC. This study highlights the positive effect of CNC addition on the mechanical properties of PLA composites, making them more suitable for specialized engineering uses.
摘要
本研究探讨了利用纤维素纳米晶体（CNC）增强聚乳酸（PLA）力学性能的潜力。CNC具有较高的比强度和刚度，被认为能够改善PLA在工程塑料应用中的性能。材料制备采用双螺杆挤出工艺，该工艺有助于实现CNC在PLA基体中的均匀分散。研究对包括拉伸强度和断裂伸长率在内的力学性能进行了全面分析，重点考察CNC浓度对PLA复合材料性能的影响。值得注意的是，与纯PLA相比，添加1 wt%的CNC使断裂应变提高了20%，表明材料的延展性得到增强。此外，加入5 wt%的CNC后，复合材料的耐热性能提高了0.3%。本研究表明，添加CNC能够对PLA复合材料的力学性能产生积极影响，使其更适用于特定的工程应用。
Keywords: Polylactic acid, Cellulose nanocrystals, Mechanical properties, Biocomposites, Engineering plastics
关键词： 聚乳酸；纤维素纳米晶体；力学性能；生物复合材料；工程塑料
How to Cite: Shi, S.-C., Hsieh, C.-F., & Rahmadiawan, D. (2024). Enhancing mechanical properties of polylactic acid through the incorporation of cellulose nanocrystals for engineering plastic applications. Teknomekanik, 7(1), 20–28. https://doi.org/10.24036/teknomekanik.v7i1.30072
Exploring QSAR of FLAP inhibitors using kernel partial least squares modeling: Insights from molecular binary fingerprints
基于核偏最小二乘建模探索FLAP抑制剂的QSAR：来自分子二元指纹的研究见解
Mandeth Kodiyil Geetha Nambiar, Department of Chemistry, Govt College Malappuram, India
Thaikadan Shameera Ahamed, Department of Chemistry, Govt College Malappuram, India
DOI: https://doi.org/10.24036/teknomekanik.v7i1.29772
Abstract
FLAP (5-Lipoxygenase Activating Protein) inhibitors, offering targeted intervention in leukotriene biosynthesis and holding therapeutic promise for inflammatory diseases like asthma, are hindered by current inhibitors' off-target effects, limited efficacy, safety concerns, potential drug interactions, and accessibility issues. Given these challenges, computational methods, particularly Quantitative Structure Activity Relationships (QSAR) modeling, are vital for developing novel FLAP inhibitors. This study specifically investigates the QSAR of FLAP inhibitors using Kernel Partial Least Squares (KPLS) modeling. Leveraging a dataset of FLAP inhibitors, we employ KPLS within the Schrödinger Canvas environment to correlate molecular descriptors with biological activity. Out of the eight models developed, the "atom pairs" fingerprint yielded a statistically significant 2D QSAR model with outstanding regression coefficient values (R2=0.9624). The model demonstrated high predictive ability for external test set data (R2pred = 0.7105), underscoring its robustness and reliability in accurately predicting biological activity based on molecular structure. Additionally, we tried to visualize the relative contributions of individual atoms within FLAP inhibitors, providing insights into their favorable and unfavorable characteristics. Through the analysis of atomic contributions, we identify key structural motifs crucial for predicting FLAP inhibitor activity. Our findings not only advance our understanding of FLAP inhibitor SAR but also demonstrate the utility of KPLS modeling and atomic contribution analysis in drug discovery efforts. Furthermore, this study contributes to the development of anti-inflammatory therapeutics by elucidating the structural determinants of FLAP inhibitor activity, with potential applications in the treatment of inflammatory disorders.
摘要
FLAP（5-脂氧合酶激活蛋白）抑制剂能够靶向干预白三烯的生物合成，并对哮喘等炎症性疾病具有潜在的治疗价值。然而，现有FLAP抑制剂受到脱靶效应、疗效有限、安全性问题、潜在药物相互作用以及可及性等因素的限制。鉴于这些挑战，计算方法，尤其是定量构效关系（Quantitative Structure Activity Relationships, QSAR）建模，对于开发新型FLAP抑制剂具有重要意义。本研究采用核偏最小二乘（Kernel Partial Least Squares, KPLS）建模方法，专门研究FLAP抑制剂的QSAR。基于FLAP抑制剂数据集，本研究在Schrödinger Canvas环境中应用KPLS，将分子描述符与生物活性进行关联分析。在建立的八个模型中，“atom pairs”指纹生成了具有统计学显著性的二维QSAR模型，其回归系数值表现优异（R2=0.9624）。该模型对外部测试集数据表现出较高的预测能力（R2pred = 0.7105），表明其具有良好的稳健性和可靠性，能够根据分子结构准确预测生物活性。此外，本研究尝试对FLAP抑制剂中各个原子的相对贡献进行可视化，从而揭示其有利和不利的结构特征。通过分析原子贡献，我们确定了对预测FLAP抑制剂活性至关重要的关键结构基序。本研究结果不仅加深了对FLAP抑制剂构效关系（SAR）的理解，而且展示了KPLS建模和原子贡献分析在药物发现研究中的应用价值。此外，本研究通过阐明FLAP抑制剂活性的结构决定因素，为抗炎治疗药物的开发提供了支持，并具有应用于炎症性疾病治疗的潜在价值。
Keywords: 5-Lipoxygenase Activating Protein, Inflammatory disorders, Kernel partial least squares regression, Visualization of atomic
关键词： 5-脂氧合酶激活蛋白；炎症性疾病；核偏最小二乘回归；原子可视化
How to Cite: Nambiar, M. K. G., & Ahamed, T. S. (2024). Exploring QSAR of FLAP inhibitors using kernel partial least squares modeling: Insights from molecular binary fingerprints. Teknomekanik, 7(1), 29–37. https://doi.org/10.24036/teknomekanik.v7i1.29772
A comparative study utilizing hybridized ant colony optimization algorithms for solving dynamic capacity of vehicle routing problems in waste collection system
利用混合蚁群优化算法求解废物收集系统动态容量车辆路径问题的比较研究
Thaeer Mueen Sahib, Department of Electrical Techniques, Kufa Technical Institute, Al-Furat Al-Awsat Technical University, Iraq
Rosmiwati Mohd-Mokhtar, School of Electrical and Electronic Engineering, Engineering Campus, Universiti Sains Malaysia, Nibong Tebal, Pulau Pinang, Malaysia
Azleena Mohd-Kassim, School of Computer Science, Universiti Sains Malaysia, Pulau Pinang, Malaysia
DOI: https://doi.org/10.24036/teknomekanik.v7i1.28872
Abstract
The waste collection stage generated 70% of the cost of the total Municipal Solid Waste (MSW) management system. Therefore, choosing the most affordable waste collection method is essential to accurately estimate the waste collection and transportation costs, thus selecting the required vehicle capacity. The study aims to design a waste collection system for calculating waste collection and transportation costs using a systematic framework that includes Hybridized Ant Colony Optimization (HACO) with Sequential Variable Neighborhood Search Change Step (SVNSCS) and Sequential Variable Neighborhood Decent (SVND). The framework addresses a Dynamic Capacity of Vehicle Routing Problem (DCVRP) and improves ACO's ability in exploration and exploitation stages. The objectives are to minimize the cost of travel distance and arrival time formulated in a mathematical model and to design a new strategy for eliminating the sub-tour problem in the following steps: (1) minimize the number of routes assigned, (2) increase the amount of waste in the vehicle capacity, and (3) define the best amount of waste allowed in vehicle capacity. The waste collection system compared HACO with ACO across four benchmark datasets. The results indicate HACO outperformance ACO at 100%, 91%, 100%, and 87%, respectively. The visualization results demonstrated that HACO has fast convergence and can be considered another essential tool for route optimization in the waste collection system.
摘要
废物收集阶段占整个城市固体废物（Municipal Solid Waste, MSW）管理系统总成本的70%。因此，选择成本最低的废物收集方式对于准确估算废物收集和运输成本，并据此确定所需车辆容量至关重要。本研究旨在设计一种废物收集系统，通过采用系统化框架计算废物收集和运输成本，该框架包括结合顺序可变邻域搜索变步长（Sequential Variable Neighborhood Search Change Step, SVNSCS）和顺序可变邻域下降（Sequential Variable Neighborhood Decent, SVND）的混合蚁群优化（Hybridized Ant Colony Optimization, HACO）算法。该框架针对动态容量车辆路径问题（Dynamic Capacity of Vehicle Routing Problem, DCVRP），并提升ACO在探索和开发阶段的能力。研究目标是通过数学模型最小化行驶距离和到达时间的成本，并设计一种新的子回路问题消除策略，包括以下步骤：（1）最小化分配的路径数量；（2）增加车辆容量中所装载的废物量；以及（3）确定车辆容量所允许的最佳废物装载量。废物收集系统采用四个基准数据集对HACO与ACO进行了比较。结果表明，在四个基准数据集上，HACO分别以100%、91%、100%和87%的比例优于ACO。可视化结果表明，HACO具有较快的收敛速度，可作为废物收集系统路径优化的另一种重要工具。
Keywords: Ant colony optimization; Dynamic capacity of vehicle routing problem; Sequential variable neighborhood search change step; Waste collection
关键词： 蚁群优化；动态容量车辆路径问题；顺序可变邻域搜索变步长；废物收集
How to Cite: Sahib, T. M., Mohd-Mokhtar, R., & Mohd-Kassim, A. (2024). A comparative study utilizing hybridized ant colony optimization algorithms for solving dynamic capacity of vehicle routing problems in waste collection system. Teknomekanik, 7(1), 38–61. https://doi.org/10.24036/teknomekanik.v7i1.28872
Experimental study of gas adsorption using high-performance activated carbon: Propane adsorption isotherm
使用高性能活性炭进行气体吸附的实验研究：丙烷吸附等温线
Tine Aprianti, Department of Chemical Engineering, Faculty of Engineering, Universitas Sriwijaya, Indonesia
Harrini Mutiara Hapsari, Department of Architecture Engineering, Faculty of Engineering, Universitas Sriwijaya, Indonesia
Debby Yulinar Permata, Department of Civil Engineering, Faculty of Engineering, Universitas Sriwijaya, Indonesia
Selvia Aprilyanti, Department of Industrial Engineering, Faculty of Engineering, Universitas Tridinanti, Indonesia
Justin Sobey, Department of Chemical Engineering, School of Engineering, The University of Western Australia, Australia
Kallan Pham, Department of Chemical Engineering, School of Engineering, The University of Western Australia, Australia
Srinivasan Kandadai, Department of Chemical Engineering, School of Engineering, The University of Western Australia, Australia
Hui Tong Chua, Department of Chemical Engineering, School of Engineering, The University of Western Australia, Australia
DOI: https://doi.org/10.24036/teknomekanik.v7i1.28672
Abstract
Activated carbon is widely used for its diverse adsorptive abilities, with a vast range of current and emerging uses. This study developed a data set for high-performing activated carbon, its adsorption abilities with differing adsorbents, and an understanding of what deviations are present compared to the widely used adsorption models. This study included the construction of Tóth isotherms in varying conditions. Building a strong isotherm correlation is desired, with an understanding of the relationship between the pores of the activated carbon sample, operating parameters, and the adsorbent. The present data could complement efforts in designing adsorbed natural gas storage systems. Experimental data was collected using a Constant Volume Variable Pressure (CVVP) apparatus, consisting of a temperature-regulated vessel containing the activated carbon sample dosed with varying adsorbents through a controlled dosing vessel. Analysis of the derived data gave a well-fitted Tóth adsorption isotherm, giving the maximum specific adsorption capacity of the activated carbon to be 2.28 g of propane per gram of activated carbon with a standard error of regression
摘要
活性炭因具有多样化的吸附能力而被广泛应用于当前及新兴的众多领域。本研究建立了高性能活性炭的数据集，研究其对不同吸附质的吸附能力，并分析其与广泛使用的吸附模型相比所存在的偏差。本研究在不同条件下构建了Tóth等温线。建立具有良好相关性的等温线模型对于理解活性炭样品孔隙、操作参数与吸附质之间的关系具有重要意义。当前数据可为吸附式天然气储存系统的设计工作提供补充。实验数据采用恒容变压（Constant Volume Variable Pressure, CVVP）装置进行采集，该装置由一个温度受控的容器组成，其中装有活性炭样品，并通过受控加料容器加入不同的吸附质。对所得数据进行分析后，得到拟合良好的Tóth吸附等温线，活性炭的最大比吸附容量为每克活性炭吸附2.28 g丙烷，回归标准误差
Keywords: Refrigeration cycle, Helium calibration, Thermodynamic, Industry, innovation and infrastructure
关键词： 制冷循环；氦气校准；热力学；工业、创新和基础设施
How to Cite: Aprianti, T., Hapsari, H. M., Permata, D. Y., Aprilyanti, S., Sobey, J., Pham, K., Kandadai, S., & Chua, H. T. (2024). Experimental study of gas adsorption using high-performance activated carbon: Propane adsorption isotherm. Teknomekanik, 7(1), 62–73. https://doi.org/10.24036/teknomekanik.v7i1.28672
Comparative analysis of the least squares method and double moving average technique for forecasting product inventory
最小二乘法与二重移动平均法在产品库存预测中的比较分析
Surfa Yondri, Department of Electronic Engineering, Politeknik Negeri Padang, Indonesia
Dwiny Meidelfi, Department of Information Technology, Politeknik Negeri Padang, Indonesia
Tri Lestari, Department of Information Technology, Politeknik Negeri Padang, Indonesia
Fanni Sukma, Department of Information Technology, Politeknik Negeri Padang, Indonesia
I.S Mutia, Department of Information Technology, Politeknik Negeri Padang, Indonesia
DOI: https://doi.org/10.24036/teknomekanik.v7i1.29672
Abstract
The cosmetics industry necessitates efficient inventory management to balance customer demand with stock control. This case study explores how Liza Cosmetics Shop optimized inventory for Lip Cream Implora 01, a popular product, using data-driven forecasting techniques. Traditional trend-based methods often resulted in inaccurate forecasts. This study proposed implementing the SDLC Waterfall Model to apply two forecasting techniques: Least Squares and Double Moving Average. Historical sales data (April 2021 - June 2022) was analyzed to identify demand patterns, seasonality, and trends. The Least Squares method was chosen for its suitability in capturing stable, linear relationships between sales and time, while the Double Moving Average method catered to data exhibiting both long-term trends and short-term fluctuations. Rigorous testing using white-box and black-box methods ensured the accurate functionality and system behavior of the implemented models. The Mean Absolute Percentage Error (MAPE) determined the method best suited for predicting July 2022 demand. This case study contributes insights into data-driven inventory management in cosmetics, highlighting benefits such as optimized stock levels, reduced costs, and enhanced customer satisfaction through improved demand fulfillment. This studys’ limitations including unforeseen marketing campaigns and economic fluctuations impacting forecasts were acknowledged. Despite these challenges, the study emphasizes the potential of data-driven techniques to optimize inventory management and meet customer demands effectively.
摘要
化妆品行业需要高效的库存管理，以平衡客户需求与库存控制。本案例研究探讨了Liza Cosmetics Shop如何利用数据驱动的预测技术，对热门产品Lip Cream Implora 01的库存进行优化。传统的基于趋势的方法通常会导致预测结果不准确。本研究提出采用SDLC瀑布模型，应用两种预测技术，即最小二乘法和二重移动平均法。通过分析2021年4月至2022年6月的历史销售数据，识别需求模式、季节性和趋势。最小二乘法因适用于捕捉销售量与时间之间稳定的线性关系而被选用，而二重移动平均法则适用于同时呈现长期趋势和短期波动的数据。通过白盒测试和黑盒测试进行严格测试，以确保所实施模型的功能和系统行为准确可靠。采用平均绝对百分比误差（Mean Absolute Percentage Error, MAPE）确定最适用于预测2022年7月需求量的方法。本案例研究为化妆品行业的数据驱动型库存管理提供了有价值的见解，突出表明通过优化库存水平、降低成本以及通过改善需求满足程度提高客户满意度等方式，可以获得显著效益。研究同时认识到，无法预见的营销活动和经济波动可能会对预测结果产生影响，这些因素构成了本研究的局限性。尽管存在这些挑战，本研究强调了数据驱动技术在优化库存管理和有效满足客户需求方面的应用潜力。
Keywords: Industry, innovation and infrastructure, Cosmetics industry, Management production, Demand prediction
关键词： 工业、创新和基础设施；化妆品行业；生产管理；需求预测
How to Cite: Yondri, S., Meidelfi, D., Lestari, T., Sukma, F., & Mutia, I. (2024). Comparative analysis of the least squares method and double moving average technique for forecasting product inventory. Teknomekanik, 7(1), 74–84. https://doi.org/10.24036/teknomekanik.v7i1.29672
Application of ground penetrating radar for evaluating foundation structure condition after earthquake
地质雷达在地震后基础结构状况评估中的应用
Risma Apdeni, Department of Civil Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Zel Citra, Department of Civil Engineering, Faculty of Engineering, Universitas Mercu Buana, Indonesia
Fitra Rifwan, Department of Civil Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Prima Yane Putri, Department of Civil Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Nevy Sandra, Department of Civil Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Yosie Malinda, Department of Civil Engineering, Faculty of Engineering, Universitas Mercu Buana, Indonesia
Paksi Dwiyanto Wibowo, Department of Civil Engineering, Faculty of Engineering, Universitas Mercu Buana, Indonesia
Reza Ferial Ashad, Department of Civil Engineering, Faculty of Engineering, Universitas Mercu Buana, Indonesia
Annisa Prita Melinda, Department of Architecture and Civil Engineering, Toyohashi University of Technology, Japan
DOI: https://doi.org/10.24036/teknomekanik.v7i1.26772
Abstract
At the time of seismic activity, the failure of the foundation structure will lead to building damage. When the West Pasaman 2022 earthquake occurred, PT. XYZ is constructing a feed mill tower. Since strong earthquake shocks were felt at the project location, foundation structure evaluation is needed to ensure the safety of the building. Ground Penetrating Radar (GPR) is a tool that is widely used to detect subsurface conditions. This study used GPR as a non-destructive testing technique to evaluate the condition of the foundation structure. The building evaluated is a high-rise steel building, using spun pile foundation. GPR test was carried out in specified lanes, with measurement tracks set at 10 lanes. Any cracks or fractures on the foundation will be indicated by the interruption of waves at the point of the crack or fracture. The GPR test results from readings of electromagnetic wave propagation showed that waves can reach the end of each foundation tested, ranging from 17.10 m to 17.82 m deep. It means that there are no cracks or fractures found on the slab, pile cap, or foundation. Analysis results showed that all slabs and pile caps thicknesses and the detected foundation piles depths are in accordance with the foundation design, which means that the foundations are still in good condition.
摘要
在地震活动发生期间，基础结构的失效将导致建筑物受损。2022年西巴松地震发生时，PT. XYZ正在建设一座饲料厂塔。由于项目所在地感受到强烈的地震震动，因此有必要对基础结构进行评估，以确保建筑物的安全。地质雷达（Ground Penetrating Radar, GPR）是一种广泛用于探测地下状况的工具。本研究采用GPR作为一种无损检测技术，对基础结构的状况进行评估。所评估的建筑物为一座采用预应力离心管桩（spun pile）基础的高层钢结构建筑。GPR测试在指定的测线进行，共设置10条测量线路。基础上的任何裂缝或断裂均会通过裂缝或断裂位置处波的中断来显示。通过对电磁波传播的读取进行分析，GPR测试结果显示，波能够到达每个被测试基础的末端，探测深度范围为17.10 m至17.82 m。这意味着在楼板、承台或基础中均未发现裂缝或断裂。分析结果表明，所有楼板和承台的厚度以及检测到的基础桩深度均符合基础设计要求，这表明基础结构仍处于良好状态。
Keywords: Sustainable cities and communities, Mitigation and disaster risk reduction, Steel Tower, Indo-Australian plate
关键词： 可持续城市与社区；减灾与灾害风险降低；钢塔；印度-澳大利亚板块
How to Cite: Apdeni, R., Citra, Z., Rifwan, F., Putri, P. Y., Sandra, N., Malinda, Y., Wibowo, P. D., Ashadi, R. F., & Melinda, A. P. (2024). Application of ground penetrating radar for evaluating foundation structure condition after earthquake. Teknomekanik, 7(1), 85–100. https://doi.org/10.24036/teknomekanik.v7i1.26772
Enhanced durability and tribological performance of polyvinyl alcohol/layered double hydroxide/tannic acid composites under repeated swelling cycles
聚乙烯醇/层状双氢氧化物/单宁酸复合材料在反复溶胀循环下的耐久性与摩擦学性能增强
Dieter Rahmadiawan, Department of Mechanical Engineering, National Cheng Kung University, Taiwan
Shih-Chen Shi, Department of Mechanical Engineering, National Cheng Kung University, Taiwan
Wei-Ting Zhuang, Department of Mechanical Engineering, National Cheng Kung University, Taiwan
Eko Indrawan, Department of Mechanical Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Yolli Fernanda, Department of Mechanical Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Budi Syahri, Department of Mechanical Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Irzal Irzal, Department of Mechanical Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
DOI: https://doi.org/10.24036/teknomekanik.v7i2.32872
Abstract
In recent years, the exploration of polyvinyl alcohol (PVA) composites has garnered significant attention due to their versatility applications in aqueous environments. However, despite their promise, neat PVA exhibit limitations such as significant mechanical degradation under repeated swelling cycles. This study investigates the durability and tribological performance of polyvinyl alcohol (PVA) composites reinforced with nickel-iron layered double hydroxide (LDH) and tannic acid (TA) under repeated swelling cycles. Building on previous research that explored composite preparation and initial characterization, this research emphasizes the effects of cyclic swelling on wear resistance, friction behavior, and mechanical properties. Tribological tests were conducted to evaluate the coefficient of friction (COF) and wear rate before and after multiple swelling cycles, alongside tensile strength and strain measurements. The results revealed that the PVA/TA2/LDH2 composite, containing the highest additive content, exhibited the lowest wear rate of 11.52 × 10⁻⁵ mm³/Nm after 3 swelling cycles, demonstrating superior resistance to material degradation. Although PVA/TA2/LDH1 exhibited a slightly lower COF, its wear rate was higher due to reduced reinforcement. Compared to neat PVA, which showed a COF increase from 0.45 to 0.53, the PVA/LDH/TA composites retained their tribological stability, with only a marginal increase in COF and wear rate. Similarly, tensile strength of PVA/TA2/LDH2 decreased by only 11% after 3 cycles (from 33.3 MPa to 30 MPa), while neat PVA experienced a 25.5% reduction (from 30 MPa to 22.5 MPa). These findings highlight the potential of PVA/LDH/TA composites for applications in aqueous environments, offering significantly enhanced long-term performance and reliability.
摘要
近年来，聚乙烯醇（PVA）复合材料因其在水环境中的多样化应用而受到广泛关注。然而，尽管具有良好的应用前景，纯PVA仍存在一定局限性，例如在反复溶胀循环过程中会发生显著的力学性能退化。本研究考察了镍铁层状双氢氧化物（LDH）和单宁酸（TA）增强的聚乙烯醇（PVA）复合材料在反复溶胀循环下的耐久性和摩擦学性能。在前期关于复合材料制备和初始表征研究的基础上，本研究重点分析循环溶胀对耐磨性、摩擦行为和力学性能的影响。通过摩擦学测试评估多次溶胀循环前后的摩擦系数（COF）和磨损率，同时测量拉伸强度和应变。结果表明，含有最高添加剂含量的PVA/TA2/LDH2复合材料在3次溶胀循环后的磨损率最低，为11.52 × 10⁻⁵ mm³/Nm，表现出优异的抗材料降解能力。尽管PVA/TA2/LDH1的COF略低，但由于增强组分含量较低，其磨损率反而较高。与COF从0.45增加至0.53的纯PVA相比，PVA/LDH/TA复合材料保持了良好的摩擦学稳定性，其COF和磨损率仅出现轻微增加。同样，PVA/TA2/LDH2的拉伸强度在3次循环后仅下降11%，从33.3 MPa降至30 MPa，而纯PVA则下降25.5%，从30 MPa降至22.5 MPa。这些研究结果表明，PVA/LDH/TA复合材料具有在水环境中应用的潜力，并能够提供显著增强的长期性能和可靠性。
Keywords: polyvinyl alchohol, LDH, tannic acid, swelling test
How to Cite: Rahmadiawan, D., Shi, S.-C., Zhuang, W.-T., Indrawan, E., Fernanda, Y., Syahri, B., & Irzal, I. (2024). Enhanced durability and tribological performance of polyvinyl alcohol/layered double hydroxide/tannic acid composites under repeated swelling cycles. Teknomekanik, 7(2), 101–111. https://doi.org/10.24036/teknomekanik.v7i2.32872
Vapor compression refrigeration system with air and water cooled condenser: Analysis of thermodynamic behavior and energy efficiency ratio
采用空气冷却与水冷式冷凝器的蒸汽压缩制冷系统：热力学行为与能效比分析
Muji Setiyo, Department of Mechanical Engineering, Faculty of Engineering, Universitas Muhammadiyah Magelang, Indonesia
Retno Rusdjijati, Department of Industrial Engineering, Faculty of Engineering, Universitas Muhammadiyah Magelang, Indonesia
Ilham Habibi, Department of Mechanical Engineering, Faculty of Engineering, Universitas Muhammadiyah Magelang, Indonesia
Muhamad Latifur Rochman, Center of Energy for Society and Industry (CESI), Universitas Muhammadiyah Magelang, Indonesia
Bagiyo Condro Purnomo, Department of Mechanical Engineering, Faculty of Engineering, Universitas Muhammadiyah Magelang, Indonesia
Fungky Dyan Pertiwi, Department of Mechanical Engineering, Faculty of Engineering, Universitas Muhammadiyah Magelang, Indonesia
Budi Waluyo, Department of Mechanical Engineering, Faculty of Engineering, Universitas Muhammadiyah Magelang, Indonesia
Rifky Ismail, Departement of Mechanical Engineering, Faculty of Engineering, Diponegoro University, Indonesia
Aditya Kolakoti, School of Marine Engineering and Technology, Indian Maritime University, India
DOI: https://doi.org/10.24036/teknomekanik.v7i2.31972
Abstract
This study presents the analysis of thermodynamic behavior and energy efficiency of a vapor compression refrigeration system with two types of condensers: air-cooled (ACC) and water-cooled (WCC). The main objective is to assess the system performance by comparing the Coefficient of Performance (COP) and Energy Efficiency Ratio (EER) under both condenser configurations. During a 12-hour test period, data on refrigerant pressure, temperature, and electrical energy consumption were collected and analyzed. The results show that the WCC system outperforms the ACC system, showing a 5.7% increase in heat rejection and a 4.2% increase in cooling capacity. In addition, the WCC system exhibits a lower compressor duty cycle and consumes less electrical energy, resulting in a higher total EER of 5.658 compared to ACC of 1.945. These findings suggest that integrating a water-cooled condenser into a refrigeration system can significantly improve energy efficiency and reduce operating costs, making it a viable option for commercial applications in tropical regions.
摘要
本研究分析了采用两种不同类型冷凝器的蒸汽压缩制冷系统的热力学行为和能效，即空气冷却式冷凝器（ACC）和水冷式冷凝器（WCC）。主要目标是通过比较两种冷凝器配置下的性能系数（Coefficient of Performance, COP）和能效比（Energy Efficiency Ratio, EER）来评估系统性能。在为期12小时的测试期间，采集并分析了制冷剂压力、温度以及电能消耗数据。结果表明，WCC系统的性能优于ACC系统，其散热量提高了5.7%，制冷量提高了4.2%。此外，WCC系统具有较低的压缩机工作周期，并消耗更少的电能，因此其总能效比（EER）达到5.658，高于ACC系统的1.945。这些研究结果表明，在制冷系统中采用水冷式冷凝器能够显著提高能源效率并降低运行成本，因此对于热带地区的商业应用而言是一种可行的选择。
Keywords: air cooled condenser, water cooled condenser, Energy Efficiency Ratio, coefficient of performance, thermodynamic behaviour
关键词： 空气冷却式冷凝器；水冷式冷凝器；能效比；性能系数；热力学行为
How to Cite: Setiyo, M., Rusdjijati, R., Habibi, I., Rochman, M. L., Purnomo, B. C., Pertiwi, F. D., Waluyo, B., Ismail, R., & Kolakoti, A. (2024). Vapor compression refrigeration system with air and water cooled condenser: Analysis of thermodynamic behavior and energy efficiency ratio. Teknomekanik, 7(2), 112–125. https://doi.org/10.24036/teknomekanik.v7i2.31972
Infiltration capacity based on soil geophysical constants using artificial infiltration in residential land
利用人工入渗研究住宅用地基于土壤地球物理常数的入渗能力
Totoh Andayono, Department of Civil Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Mas Mera, Department of Civil Engineering, Faculty of Engineering, Universitas Andalas, Indonesia
Junaidi Junaidi, Department of Civil Engineering, Faculty of Engineering, Universitas Andalas, Indonesia
Dalrino Dalrino, Department of Civil Engineering, Politeknik Negeri Padang, Indonesia
DOI: https://doi.org/10.24036/teknomekanik.v7i2.31372
Abstract
Conversion of catch-land into residential land in urban areas reduces infiltration, and increases surface flow and flood risk. Artificial infiltration is a potential solution to increase infiltration capacity, but its effectiveness is highly dependent on the physical characteristics of the soil, including geophysical constants. This study aims to determine the level of infiltration capacity based on the value of soil geophysical constants using artificial infiltration in residential land in Padang. Measurements were carried out using the Horton method and double-ring infiltrometer in several residential locations. The study results show that the soil characteristics of residential land in Padang consist of the soil texture of sand, loamy sand, and sandy loam, which have high moisture content, large fill weight, and low porosity, causing low infiltration rate and high surface flow. Artificial infiltration can significantly increase the infiltration capacity, especially on sandy soils with high hydraulic conductivity. The soil geophysical constant, k, is classified according to field measurement results. In the lower range of 1.2 < k ≤ 1.9, the average infiltration capacity was found at 625.1 mm/hour. Within the interval of 1.9 < k ≤ 2.6, the mean capacity decreased to 587.7 mm/hour, but in the upper interval of 2.6 < k ≤ 3.3, the average infiltration capacity was 499 mm/hour. Large soil geophysical constants reveal higher infiltration capacity, while small geophysical constants indicate low infiltration capacity.
摘要
城市地区将集水土地转变为住宅用地会降低土壤入渗能力，并增加地表径流和洪水风险。人工入渗是一种提高入渗能力的潜在解决方案，但其有效性高度依赖于土壤的物理特性，包括地球物理常数。本研究旨在利用人工入渗方法，根据土壤地球物理常数的数值确定巴东住宅用地的入渗能力水平。研究采用Horton方法和双环入渗仪，在多个住宅区域进行测量。研究结果表明，巴东住宅用地的土壤特征包括砂土、壤质砂土和砂质壤土，其具有较高的含水量、较大的填土重量和较低的孔隙率，从而导致较低的入渗速率和较高的地表径流。人工入渗能够显著提高入渗能力，尤其是在水力传导系数较高的砂质土壤中。根据现场测量结果，对土壤地球物理常数k进行了分类。在较低范围1.2 < k ≤ 1.9内，平均入渗能力为625.1 mm/hour。在1.9 < k ≤ 2.6的区间内，平均入渗能力下降至587.7 mm/hour；而在较高区间2.6 < k ≤ 3.3内，平均入渗能力为499 mm/hour。较大的土壤地球物理常数表明具有较高的入渗能力，而较小的地球物理常数则表明入渗能力较低。
Keywords: infiltration capacity, artificial infiltration, residential land, geophysical constants
关键词： 入渗能力；人工入渗；住宅用地；地球物理常数
How to Cite: Andayono, T., Mera, M., Junaidi, J., & Dalrino, D. (2024). Infiltration capacity based on soil geophysical constants using artificial infiltration in residential land. Teknomekanik, 7(2), 126–138. https://doi.org/10.24036/teknomekanik.v7i2.31372
The conversion of nata de coco bacterial cellulose into cellulose nanofibers using high shear mixer with eco-friendly fluid dynamics method
利用高剪切混合器通过环保流体动力学方法将椰果细菌纤维素转化为纤维素纳米纤维
Amun Amri, Department of Chemical Engineering, Faculty of Engineering, Universitas Riau, Indonesia
Diana Eka Putri, Department of Chemical Engineering, Faculty of Engineering, Universitas Riau, Indonesia
Dhina Febryza, Department of Chemical Engineering, Faculty of Engineering, Universitas Riau, Indonesia
Salsabilla Diva Voadi, Department of Chemical Engineering, Faculty of Engineering, Universitas Riau, Indonesia
Syelvia Putri Utami, Department of Chemical Engineering, Faculty of Engineering, Universitas Riau, Indonesia
Hussein A. Miran, Department of Physics, College of Education for Pure Science, Ibn Al-Haitham, University of Baghdad, Iraq
M. Mahbubur Rahman, Department of Physics, Jahangirnagar University, Bangladesh
DOI: https://doi.org/10.24036/teknomekanik.v7i2.32972
Abstract
Nanocellulose is widely applied in various fields due to its superior characteristics. Several methods have been developed to synthesize it, but they still have limitedness as being non-eco-friendly and inefficient use. Therefore, the synthesis of nanocellulose from sustainable sources is being developed using a simple and eco-friendly method. This study successfully produced a low viscosity gel suspension of cellulose nanofibers (CNF) from bacterial cellulose (BC) derived from Nata de Coco using a high shear mixer (HSM). The mixture of BC and water in a 1:1 ratio was processed with various rotational speeds and times in the HSM. The suspension result was characterized using an Ostwald viscometer, UV-vis spectrophotometer, lux meter, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), particle size analyzer (PSA), and x-ray diffraction (XRD). Based on the characterization, it was confirmed that higher rotational speeds and extended processing times reduced the suspension viscosity and increased light transmittance, indicating a reduction in BC size to the submicron/nanometer scale. The best light transmittance was achieved with the HSM at 4500 rpm for 180 min, resulting in a viscosity drop from 232.67 mPa.s to 1.45 mPa.s. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis showed that the CNF retained its fibrous structure with nanometer-scale widths and high porosity without significant changes in crystallinity.
摘要
纳米纤维素因其优异的特性而被广泛应用于各个领域。尽管已经开发了多种纳米纤维素合成方法，但这些方法仍存在不够环保和使用效率较低等局限性。因此，研究人员正在开发一种采用简单且环保方法从可持续资源中合成纳米纤维素的技术。本研究利用高剪切混合器（High Shear Mixer, HSM），成功将来源于椰果（Nata de Coco）的细菌纤维素（Bacterial Cellulose, BC）制备成低黏度的纤维素纳米纤维（Cellulose Nanofibers, CNF）凝胶悬浮液。将BC与水按照1:1的比例混合，并在HSM中采用不同的转速和处理时间进行处理。所得悬浮液分别采用Ostwald黏度计、紫外-可见分光光度计、照度计、扫描电子显微镜（SEM）、傅里叶变换红外光谱（FTIR）、粒度分析仪（PSA）和X射线衍射（XRD）进行表征。根据表征结果确认，提高转速和延长处理时间能够降低悬浮液黏度并提高透光率，表明BC尺寸减小至亚微米/纳米尺度。在4500 rpm下处理180 min时，HSM获得了最佳透光率，黏度由232.67 mPa.s降至1.45 mPa.s。扫描电子显微镜（SEM）和X射线衍射（XRD）分析表明，CNF仍保持纤维状结构，具有纳米尺度的纤维宽度和较高的孔隙率，且结晶度未发生显著变化。
Keywords: high shear mixer, bacterial cellulose, cellulose nanofibers, viscosity, light transmittance
关键词： 高剪切混合器；细菌纤维素；纤维素纳米纤维；黏度；透光率
How to Cite: Amri, A., Putri, D. E., Febryza, D., Voadi, S. D., Utami, S. P., Miran, H. A., & Rahman, M. M. (2024). The conversion of nata de coco bacterial cellulose into cellulose nanofibers using high shear mixer with eco-friendly fluid dynamics method. Teknomekanik, 7(2), 139–155. https://doi.org/10.24036/teknomekanik.v7i2.32972
Transformative process: Crafting imines from nitrobenzene and benzyl alcohol coupling with cerium oxide modified mesoporous SBA-15
转化过程：利用氧化铈改性介孔SBA-15催化硝基苯与苄醇偶联合成亚胺
Soumini Chandralayam, Department of Chemistry, Mes Keveeyam College Valanchery Keveeyam College, India
Sugunan Sankaran, Department of Applied Chemistry, Cochin University of Science and Technology, India
DOI: https://doi.org/10.24036/teknomekanik.v7i2.31772
Abstract
A low-cost and eco-friendly cerium oxide modified mesoporous SBA-15 catalyst was developed by wet impregnation. It enables sequential oxidation of benzyl alcohol and reduction of nitrobenzene, followed by imine formation in a single and solvent-free system. Characterization confirms homogeneous cerium oxide dispersion, high stability, and enhanced redox properties. The optimized catalyst demonstrates excellent conversion and selectivity, attributed to the mesoporous SBA support, acidic properties, and cerium's redox functionality. Elevated temperatures enhance benzyl alcohol dehydration and hydrogen diffusion, facilitating intermediate aniline formation by a borrowing-hydrogen mechanism and followed by imine synthesis. It eliminates solvents, reduces byproducts, and achieves high atom economy and renewability. It presents a significant advance in sustainable catalysis. The catalyst's robustness and ease of recovery strengthen its practicality for repeated cycles. The findings provide a scalable and energy-efficient solution for greener imine synthesis with potential applications in industrial processes requiring efficient and eco-friendly chemical production. It ensures minimal environmental impact and offers a cost-effective pathway for high-value chemical synthesis. This study supports the SDGs by promoting sustainable industrial practices through the development of a low-cost and eco-friendly catalyst that reduces environmental impact, enhances energy efficiency, and contributes to greener chemical production.
摘要
采用湿法浸渍法制备了一种低成本且环保的氧化铈改性介孔SBA-15催化剂。该催化剂能够在单一且无溶剂体系中依次实现苄醇氧化和硝基苯还原，随后形成亚胺。表征结果证实，氧化铈在催化剂中均匀分散，具有较高的稳定性和增强的氧化还原性能。优化后的催化剂表现出优异的转化率和选择性，这归因于介孔SBA载体、酸性性质以及铈的氧化还原功能。在较高温度下，苄醇脱水和氢扩散得到增强，通过借氢机制促进中间体苯胺的形成，随后进一步合成亚胺。该过程无需使用溶剂，可减少副产物，并实现较高的原子经济性和可再生性，体现了可持续催化领域的重要进展。催化剂具有良好的稳定性且易于回收，从而增强了其在重复循环中的实用性。研究结果为更绿色的亚胺合成提供了一种可规模化且具有能源效率的解决方案，并有望应用于需要高效、环保化学品生产的工业过程。该方法能够最大限度地降低环境影响，并为高附加值化学品的合成提供具有成本效益的途径。本研究通过开发一种低成本、环保且能够降低环境影响、提高能源效率并促进绿色化学品生产的催化剂，支持可持续发展目标（SDGs），推动可持续工业实践。
Keywords: mesoporous SBA-15, imine formation, ceria, catalyst development
关键词： 介孔SBA-15；亚胺形成；氧化铈；催化剂开发
How to Cite: Chandralayam, S., & Sankaran, S. (2024). Transformative process: Crafting imines from nitrobenzene and benzyl alcohol coupling with cerium oxide modified mesoporous SBA-15. Teknomekanik, 7(2), 156–175. https://doi.org/10.24036/teknomekanik.v7i2.31772
Classifying four maturity categories of coffee cherry using CNN-VGG19
利用CNN-VGG19对咖啡果实四种成熟度类别进行分类
Dominic Olango Cagadas, Department of Electronics Technology, University of Science and Technology of Southern Philippines, Philippines
Dwi Sudarno Putra, Department of Automotive Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Kristine Mae Paboreal Dunque, Department of Electronics Technology, University of Science and Technology of Southern Philippines, Philippines
Meri Azmi, Department of Information Technology, Politeknik Negeri Padang, Indonesia
DOI: https://doi.org/10.24036/teknomekanik.v7i2.31072
Abstract
The local coffee farmers employ manual inspection to identify the maturity of coffee cherries that are inefficient in labor and time. Thus, the objective of this study is to develop a CNN-VGG19 algorithm model that can accurately detect the maturity image of coffee cherry samples, and classify them into: unripe, semi-ripe, ripe, and overripe categories. The proposed solution will provide local coffee farmers with an automated and more accurate classification of the quality of coffee cherries. The visual geometry group-19 was employed to increase the object recognition model performance of the proposed algorithm while maintaining higher accuracy and quicker throughput, thus increasing revenues. The images are utilized as training and test set data. They were then processed by using the feature extraction of CNN-VGG19 deep learning model, and got four coffee cherry maturity classes. The model architecture attained a 90.00 % accuracy. Furthermore, the increase in both the validation and training accuracy graph with a corresponding decrease in both the validation and training loss graph propounds that the model performance has improved.
摘要
当地咖啡农民通常采用人工检查方式来识别咖啡果实的成熟度，这种方法在人力和时间方面效率较低。因此，本研究旨在开发一种CNN-VGG19算法模型，能够准确检测咖啡果实样本图像的成熟度，并将其分为未成熟、半成熟、成熟和过熟四个类别。所提出的解决方案将为当地咖啡农民提供一种自动化且更加准确的咖啡果实品质分类方法。研究采用Visual Geometry Group-19（VGG19）来提高所提出算法的目标识别模型性能，同时保持较高的准确率和更快的处理速度，从而提高收益。研究使用图像作为训练集和测试集数据，随后利用CNN-VGG19深度学习模型进行特征提取，并获得四种咖啡果实成熟度类别。该模型架构达到了90.00%的准确率。此外，验证准确率和训练准确率曲线均呈上升趋势，同时验证损失和训练损失曲线均呈下降趋势，这表明模型的性能得到了改善。
Keywords: coffee fruit, convolutional neural network, image processing, object detection, visual geometry group
关键词： 咖啡果实；卷积神经网络；图像处理；目标检测；视觉几何组
How to Cite: Cagadas, D. O., Putra, D. S., Dunque, K. M. P., & Azmi, M. (2024). Classifying four maturity categories of coffee cherry using CNN-VGG19. Teknomekanik, 7(2), 176–184. https://doi.org/10.24036/teknomekanik.v7i2.31072
The impact of exponentially varying viscosity on magnetized tangent hyperbolic nanofluid over a nonlinear stretching sheet with PHF and PMF conditions
指数变化黏度对具有PHF和PMF条件的非线性拉伸表面上磁化切向双曲正切纳米流体的影响
Mohamed Magdy Ghazy, Department of Mathematics, Faculty of Science (Men), Al-Azhar University, Egypt
Khalid Saad Mekheimer, Department of Mathematics, Faculty of Science (Men), Al-Azhar University, Egypt
Rabea Elshennawy Abo-Elkhair, Department of Basic Science, October High Institute of Engineering Technology-OHI, Egypt
Ahmed Mostafa Megahed, Department of Mathematics, Faculty of Science, Benha University, Egypt
DOI: https://doi.org/10.24036/teknomekanik.v8i1.33772
Abstract
This article aims to explore the characteristics of tangent hyperbolic nanofluid flow over a nonlinear exponentially stretching sheet with suction or injection embedded in a Darcy porous medium. We consider a non-Newtonian magnetohydrodynamic fluid with prescribed surface temperature and temperature-dependent viscosity, relevant to applications in aerospace, automotive and marine engineering, electronic cooling, solar-energy systems, and filtration. Given its fundamental importance, the study of prescribed exponential order heat flux (PHF) and prescribed mass flux (PMF) of hyperbolic tangent nanofluid became a key in research aimed at improving the efficiency and performance of these systems. The partial differential equations are converted into ODES by using transformation procedure. The system of transformed equations is numerically solved by Chebyshev spectral method. Graphical results illustrate the impact of key parameters on concentration, velocity, and temperature profiles, while tabulated data report the local Nusselt number, Sherwood number, and skin friction coefficient. Our results show that increasing both the power-law index and the variable-viscosity parameter reduces the fluid’s velocity while elevating its temperature and concentration. The comparative analysis confirms a high degree of agreement with previous studies. This research holds significant importance as it focuses on the extensive utilization of tangent hyperbolic nanofluids in cooling electronic components that produce substantial heat during their operation.
摘要
本文旨在探讨嵌入Darcy多孔介质中的非线性指数拉伸表面上具有吸入或喷射条件的切向双曲正切纳米流体流动特性。研究考虑了一种具有给定表面温度和温度依赖黏度的非牛顿磁流体动力学流体，该研究与航空航天、汽车与船舶工程、电子设备冷却、太阳能系统以及过滤等应用密切相关。鉴于其基础性重要意义，对指数阶给定热通量（PHF）和给定质量通量（PMF）条件下双曲正切纳米流体的研究已成为提高相关系统效率和性能的重要研究方向。通过变换过程，将偏微分方程转换为常微分方程（ODEs）。采用Chebyshev谱方法对变换后的方程组进行数值求解。图形结果展示了关键参数对浓度、速度和温度分布的影响，同时表格数据给出了局部Nusselt数、Sherwood数和皮肤摩擦系数。研究结果表明，随着幂律指数和可变黏度参数的增加，流体速度降低，而流体温度和浓度升高。比较分析结果表明，本研究结果与已有研究具有高度一致性。本研究具有重要意义，因为其重点关注双曲正切纳米流体在冷却运行过程中产生大量热量的电子元件方面的广泛应用。
Keywords: tangent hyperbolic nanofluid, variable heated viscosity, exponential stretching sheet, PHF and PMF, chebyshev spectral method
关键词： 切向双曲正切纳米流体；可变加热黏度；指数拉伸表面；PHF和PMF；Chebyshev谱方法
How to Cite: Ghazy, M. M., Mekheimer, K. S., Abo-Elkhair, R. E., & Megahed, A. M. (2025). The impact of exponentially varying viscosity on magnetized tangent hyperbolic nanofluid over a nonlinear stretching sheet with PHF and PMF conditions. Teknomekanik, 8(1), 1–23. https://doi.org/10.24036/teknomekanik.v8i1.33772
Evaluation and characterization of charcoal briquettes using damar binder for sustainable energy
使用达玛树脂粘结剂制备木炭煤球用于可持续能源的评价与表征
Hendri Nurdin, Department of Mechanical Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Waskito Waskito, Department of Mechanical Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Dani Harmanto, Department of Aeronautical Engineering, De Montfort University, United Kingdom
Purwantono Purwantono, Department of Mechanical Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Andre Kurniawan, Department of Mechanical Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Dori Yuvenda, Department of Mechanical Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Yoszi Mingsih Anaperta, Department of Mining Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
DOI: https://doi.org/10.24036/teknomekanik.v8i1.33672
Abstract
Palm kernel shells have great potential as biomass and renewable energy sources. Its utilization has not been maximized which is only directly burned which causes air pollution. The accumulation of solid waste in the crude palm oil processing industry negatively impacts the environment. The research aims to determine the characteristics and quality of charcoal briquettes with palm kernel shell carbonization. The main findings of this study are the calorific value, water content, volatile matter, ash content, and fixed carbon in palm kernel shell charcoal briquettes with damar binder. The experimental research method was carried out by carbonizing the raw materials of palm kernel shell briquettes, applying various concentrations of damar binder mixtures. The technical parameters of briquette making were 10 MPa pressure, 60 mesh size, and different carbonization temperatures by furnace. The calorific and proximate were empirically measured by using a bomb calorimeter. This research produced palm kernel shell charcoal briquettes with a calorific value of 30.72 MJ/kg at a carbonization temperature of 500oC and concentration of 85%:15%, a moisture content of 5.18%, volatile matter of 32.72%, ash content of 2.81%, and fixed carbon of 57.90%. Palm kernel shell charcoal briquetting technology is potentially a recommended alternative solid fuel. Consequently, developing renewable energy that is environmentally friendly leads to achieve sustainable energy security. By utilizing waste, the negative impacts on the environment can be overcome and energy needs are also resolved.
摘要
棕榈仁壳具有作为生物质和可再生能源的巨大潜力。然而，目前其利用尚未得到充分开发，主要是直接燃烧，从而造成空气污染。毛棕榈油加工行业中固体废物的积累也会对环境产生负面影响。本研究旨在确定棕榈仁壳炭化制备木炭煤球的特性和质量。本研究的主要研究内容包括使用达玛树脂粘结剂制备的棕榈仁壳木炭煤球的热值、含水量、挥发分、灰分和固定碳含量。实验研究通过对棕榈仁壳煤球原料进行炭化，并采用不同浓度的达玛树脂粘结剂混合物进行制备。煤球制备的技术参数为10 MPa压力、60目粒度以及采用炉子进行不同温度的炭化处理。热值和工业分析通过氧弹量热仪进行实验测定。本研究制备的棕榈仁壳木炭煤球在500°C炭化温度和85%:15%的配比条件下，热值达到30.72 MJ/kg，含水量为5.18%，挥发分为32.72%，灰分为2.81%，固定碳含量为57.90%。棕榈仁壳木炭煤球技术具有作为替代固体燃料的潜力。因此，开发环保型可再生能源有助于实现可持续能源安全。通过废物资源化利用，可以减少其对环境造成的负面影响，同时满足能源需求。
Keywords: affordable and clean energy, alternative energy, renewable energy, calorific value
关键词： 经济实惠和清洁能源；替代能源；可再生能源；热值
How to Cite: Nurdin, H., Waskito, W., Harmanto, D., Purwantono, P., Kurniawan, A., Yuvenda, D., & Anaperta, Y. M. (2025). Evaluation and characterization of charcoal briquettes using damar binder for sustainable energy. Teknomekanik, 8(1), 24–37. https://doi.org/10.24036/teknomekanik.v8i1.33672
Characteristics of sisal-epoxy composite boards with sodium chloride-treated fibers at different treatment temperatures
不同处理温度下氯化钠处理剑麻纤维增强环氧树脂复合板的特性
Tamaryska Setyayunita, Department of Mechanical and Industrial Engineering, Faculty of Engineering, Universitas Negeri Malang, Indonesia
Heru Suryanto, Department of Mechanical and Industrial Engineering, Faculty of Engineering, Universitas Negeri Malang, Indonesia
Aminnudin Aminnudin, Department of Mechanical and Industrial Engineering, Faculty of Engineering, Universitas Negeri Malang, Indonesia
Azlin Fazlina, Osman Faculty of Chemical Engineering & Technology, Universiti Malaysia Perlis, Malaysia
Uun Yanuhar, Department of Aquatic Resources Management, Universitas Brawijaya, Indonesia
DOI: https://doi.org/10.24036/teknomekanik.v8i1.35572
Abstract
The growing environmental concerns associated with synthetic fibers have led to the increased adoption of bio-fibers as reinforcements in polymer composites. Sodium chloride (NaCl) is explored as a fiber treatment agent to enhance the adhesion between fibers and the matrix. The study aims to evaluate the effects of NaCl treatment on the characteristics of sisal fiber-epoxy composite boards. A completely randomized design was applied with three factors: treatment temperature (25 °C and 100 °C), NaCl concentration (1, 3, and 5 wt%), and composite board density (0.40, 0.60, and 0.80 g/cm³). Sisal fibers were soaked in NaCl solutions for one hour, rinsed, dried, and manually blended with epoxy at a ratio of 80:20 wt%. Composite board properties were observed according to the standards of JIS-A-5908, Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy (SEM). Results indicated that increasing the NaCl concentration and treatment temperature significantly improved the properties of the composite board. The optimal parameters (5wt% NaCl, 100 °C, 0.80g/cm³) yielded a modulus of elasticity of 4.59±0.26 GPa, modulus of rupture of 18.88±0.03 MPa, and internal bond strength of 3.92±0.18 MPa, representing increases of 200.32%, 130.65%, and 218.70%, respectively. Thickness swelling decreased to 2.13±0.43% (48.14%) and water absorption to 8.95±0.05% (32.25%). These findings confirm that NaCl treatment is an eco-friendly method to enhance the mechanical strength and moisture resistance of biofiber composites. It also supports the development of high-performance composite boards.
摘要
与合成纤维相关的环境问题日益受到关注，促使生物纤维作为聚合物复合材料增强材料的应用不断增加。本研究探索使用氯化钠（NaCl）作为纤维处理剂，以增强纤维与基体之间的黏附性。本研究旨在评估NaCl处理对剑麻纤维-环氧树脂复合板特性的影响。采用完全随机设计，设置三个因素：处理温度（25 °C和100 °C）、NaCl浓度（1、3和5 wt%）以及复合板密度（0.40、0.60和0.80 g/cm³）。剑麻纤维在NaCl溶液中浸泡1小时，随后进行冲洗、干燥，并按照80:20 wt%的比例与环氧树脂进行手工混合。根据JIS-A-5908标准、傅里叶变换红外光谱（FTIR）和扫描电子显微镜（SEM）对复合板性能进行表征。结果表明，提高NaCl浓度和处理温度能够显著改善复合板的性能。最佳参数条件（5 wt% NaCl、100 °C、0.80 g/cm³）下，弹性模量达到4.59±0.26 GPa，破坏模量达到18.88±0.03 MPa，内结合强度达到3.92±0.18 MPa，分别提高了200.32%、130.65%和218.70%。厚度膨胀率降低至2.13±0.43%（降低48.14%），吸水率降低至8.95±0.05%（降低32.25%）。这些研究结果证实，NaCl处理是一种环保的方法，可用于提高生物纤维复合材料的机械强度和耐湿性能，同时有助于高性能复合板材的开发。
Keywords: composite boards, mechanical properties, epoxy, NaCl treatment, sisal fiber
关键词： 复合板；机械性能；环氧树脂；NaCl处理；剑麻纤维
How to Cite: Setyayunita, T., Suryanto, H., Aminnudin, A., Osman, A. F., & Yanuhar, U. (2025). Characteristics of sisal-epoxy composite boards with sodium chloride-treated fibers at different treatment temperatures. Teknomekanik, 8(1), 38–51. https://doi.org/10.24036/teknomekanik.v8i1.35572
High-pressure adsorption isothermal on a novel microporous material from polyethylene terephthalate plastic waste in carbon dioxide capture applications
聚对苯二甲酸乙二醇酯塑料废弃物制备新型微孔材料的高压吸附等温线及其在二氧化碳捕集中的应用
Awaludin Martin, Department of Mechanical Engineering, Faculty of Engineering, Universitas Riau, Indonesia
Erman Taer, Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Riau, Indonesia
Nasruddin Nasruddin, Department of Mechanical Engineering, Faculty of Engineering, Universitas Indonesia, Indonesia
Nur Khotimah, Department of Mechanical Engineering, Faculty of Engineering, Universitas Riau, Indonesia
DOI: https://doi.org/10.24036/teknomekanik.v8i1.36172
Abstract
Carbon capture is a vital strategy for mitigating climate change by reducing industrial CO2 emissions. Adsorption technology using microporous material shows significant promise. However, significant challenges persist in developing cost-effective and sustainable adsorbents. This study addresses this issue by simultaneously enabling CO2 adsorption and plastic waste utilization through activated carbon derived from polyethylene terephthalate (PET). It was evaluated under isothermal conditions (27°C, 35°C, and 45°C) at pressures up to 3500 kPa. The maximum CO2 adsorption capacity was 0.21313 kg/kg at 27°C and 3504.39 kPa, demonstrating the effectiveness of PET-derived activated carbon in capturing CO2. The Toth isotherm model exhibited a strong fit with experimental data, with an R2 of more than 99%. The Clausius-Clapeyron equation yielded an adsorption heat of 2223.66 kJ/kg using the Toth fitting, and the Chakraborty-Saha-Koyama model yielded a heat of 2383.65 kJ/kg, confirming strong adsorption potential. These results underline PET waste as a viable precursor for sustainable carbon capture adsorbents. Furthermore, the results provide essential data for developing numerical models to optimize adsorption-based carbon capture technologies
摘要
碳捕集是通过减少工业CO2排放来缓解气候变化的重要策略。利用微孔材料的吸附技术具有巨大的应用潜力。然而，开发具有成本效益且可持续的吸附剂仍面临重大挑战。本研究通过利用聚对苯二甲酸乙二醇酯（PET）制备活性炭，同时实现CO2吸附和塑料废弃物资源化利用，从而解决这一问题。该材料在27°C、35°C和45°C的等温条件下进行了评价，压力最高达到3500 kPa。最大CO2吸附容量为0.21313 kg/kg，在27°C和3504.39 kPa条件下获得，表明PET衍生活性炭具有良好的CO2捕集效果。Toth等温线模型与实验数据具有良好的拟合效果，R2超过99%。采用Toth拟合结合Clausius-Clapeyron方程计算得到吸附热为2223.66 kJ/kg，而Chakraborty-Saha-Koyama模型得到的吸附热为2383.65 kJ/kg，进一步证实了其较强的吸附潜力。这些结果表明，PET废弃物可作为制备可持续碳捕集吸附剂的可行前驱体。此外，本研究结果为建立数值模型和优化基于吸附的碳捕集技术提供了重要数据。
Keywords: carbon capture, adsorption isotherm, heat of adsorption, isosteric adsorption
How to Cite: Martin, A., Taer, E., Nasruddin, N., & Khotimah, N. (2025). High-pressure adsorption isothermal on a novel microporous material from polyethylene terephthalate plastic waste in carbon dioxide capture applications. Teknomekanik, 8(1), 52–66. https://doi.org/10.24036/teknomekanik.v8i1.36172
Microstructural and mechanical properties of 17-4PH stainless steel fabricated via material extrusion 3D printing
材料挤出3D打印制备17-4PH不锈钢的微观结构与力学性能
Dang Long Cao, Department of Mechanical Engineering, Vinh Long University of Technology Education, Vietnam
Van Cuong Nguyen, Department of Mechanical Engineering, University of Transport and Communications, Vietnam
Van Nga Tran Thi, Department of Mechanical Engineering, University of Transport and Communications, Vietnam
DOI: https://doi.org/10.24036/teknomekanik.v8i1.34872
Abstract
This study investigates the microstructural and mechanical properties of metal 3D printing products fabricated using material extrusion technology. It focuses on the critical post-processing stages: printing, washing, and sintering. A Markforged 3D printing system and 17-4 PH stainless steel material were utilized to assess the effect of printing orientation and sintering conditions on microstructural and mechanical properties of the final product. The results demonstrate that printing orientation and sintering conditions critically govern the microstructural and mechanical properties of the final product. During sintering, the microstructure undergoes significant phase transformation and densification, while micropores and shrinkage voids emerge due to capillary stresses during binder removal. Furthermore, the mechanical properties are significantly influenced by the combined effects of printing orientation and sintering conditions. Optimizing deposition parameters (printing orientations and sintering conditions) substantially enhances the mechanical performance of the final printed product.
摘要
本研究研究了采用材料挤出技术制备的金属3D打印产品的微观结构和力学性能，重点关注打印、清洗和烧结等关键后处理阶段。研究采用Markforged 3D打印系统和17-4 PH不锈钢材料，评估打印方向和烧结条件对最终产品微观结构和力学性能的影响。结果表明，打印方向和烧结条件对最终产品的微观结构和力学性能具有关键影响。在烧结过程中，微观结构发生显著的相变和致密化，而在粘结剂去除过程中，由于毛细应力的作用，会产生微孔和收缩孔隙。此外，打印方向和烧结条件的综合作用会显著影响材料的力学性能。通过优化沉积参数（打印方向和烧结条件），能够显著提高最终打印产品的力学性能。
Keywords: additive manufacturing, material extrusion technology, 3D Metal printing, microstructure
关键词： 增材制造；材料挤出技术；金属3D打印；微观结构
How to Cite: Cao, D. L., Nguyen, V. C., & Thi, V. N. T. (2025). Microstructural and mechanical properties of 17-4PH stainless steel fabricated via material extrusion 3D printing. Teknomekanik, 8(1), 67–78. https://doi.org/10.24036/teknomekanik.v8i1.34872
Durability performances of ferronickel slag aggregate and seawater concrete
镍铁渣骨料与海水混凝土的耐久性能
Nevy Sandra, Department of Civil Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Muhammad Akbar Caronge, Department of Civil Engineering, Faculty of Engineering, Universitas Hasanuddin, Indonesia
Jati Sunaryati, Department of Civil Engineering, Faculty of Engineering, Universitas Andalas, Indonesia
Keiyu Kawaai, Department of Civil and Environmental Engineering, Faculty of Engineering, Ehime University, Japan
Willick Nsama, Department of Water Supply and Sanitation, Ministry of Water Development and Sanitation, Zambia
Yaumal Arbi, Department of Civil Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Ari Syaiful Rahman Arifin, Department of Civil Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
DOI: https://doi.org/10.24036/teknomekanik.v8i1.34572
Abstract
The rising demand for concrete in the building sector has resulted in the exhaustion of natural sand and freshwater supplies, leading to the pursuit of sustainable substitutes. Coastal areas have plentiful ferronickel slag (SL) and seawater (SW), which can be used to manufacture concrete. Nevertheless, the possibility of corrosion to steel reinforcement raises concerns that require further research. This investigation examines the mechanical and durability performance of concrete that incorporates SL as a partial replacement for fine aggregate and SW as a mixing component. The objective is to optimize SL content to improve compressive strength, resistance to chloride ions, and overall durability. Experimental results show that replacing 25% of the aggregate with SL yields the best combination of workability, strength, and durability, significantly enhancing compressive strength, decreasing porosity, and lessening chloride ion penetration, as evidenced by the Rapid Chloride Penetration Test (RCPT). Although seawater promotes early-age hydration and strength development, its extended use slightly diminishes compressive strength due to salt-induced micro-cracking. However, SL counters these effects, making SW–SL mixture a feasible and sustainable option for concrete production in coastal and resource-limited areas. A significant relationship between RCPT and compressive strength underscores the important role of SL in densifying the matrix and improving impermeability. The concrete mixture with 25% SL exhibits the lowest abrasion weight loss at 28 and 120 days, showing improved durability. This study highlights the potential of using SL and seawater to create eco-friendly and high-performance concrete for harsh environments.
摘要
建筑行业对混凝土日益增长的需求导致天然砂和淡水资源逐渐枯竭，从而促使人们寻求可持续的替代材料。沿海地区拥有丰富的镍铁渣（SL）和海水（SW）资源，可用于混凝土生产。然而，钢筋可能发生腐蚀的问题引起了关注，需要进一步研究。本研究考察了以SL部分替代细骨料并以SW作为拌合组分的混凝土的力学性能和耐久性能。研究旨在优化SL含量，以提高抗压强度、抗氯离子性能和整体耐久性。实验结果表明，以SL替代25%的骨料能够获得和易性、强度和耐久性之间的最佳组合，显著提高抗压强度，降低孔隙率，并减少氯离子渗透，这一点通过快速氯离子渗透试验（Rapid Chloride Penetration Test, RCPT）得到了证实。尽管海水能够促进早期水化和强度发展，但长期使用会因盐诱导的微裂纹而使抗压强度略有降低。然而，SL能够抵消这些影响，使SW–SL混合体系成为沿海地区和资源有限地区混凝土生产中一种可行且可持续的选择。RCPT与抗压强度之间存在显著关系，进一步凸显了SL在使基体致密化和提高抗渗性能方面的重要作用。含25% SL的混凝土在28天和120天时表现出最低的磨耗质量损失，显示出更好的耐久性。本研究表明，利用SL和海水制备环保型高性能混凝土具有应用于恶劣环境的潜力。
Keywords: workability, permeability, pozzolanicity, no poverty, sustainable cities and communities
关键词： 和易性；渗透性；火山灰活性；无贫穷；可持续城市与社区
How to Cite: Sandra, N., Caronge, M. A., Sunaryati, J., Kawaai, K., Nsama, W., Arbi, Y., & Arifin, A. S. R. (2025). Durability performances of ferronickel slag aggregate and seawater concrete. Teknomekanik, 8(1), 79–98. https://doi.org/10.24036/teknomekanik.v8i1.34572
Natural fiber substitution in glass fiber-reinforced plastics: A Tensile properties simulation
玻璃纤维增强塑料中的天然纤维替代：拉伸性能模拟
Alief Wikarta, Department of Mechanical Engineering, Faculty of Industrial Technology and Systems Engineering, Institut Teknologi Sepuluh Nopember, Indonesia
Chandya Andikusuma, Department of Mechanical Engineering, Faculty of Industrial Technology and Systems Engineering, Institut Teknologi Sepuluh Nopember, Indonesia
Julendra Ariatedja, Department of Mechanical Engineering, Faculty of Industrial Technology and Systems Engineering, Institut Teknologi Sepuluh Nopember, Indonesia
I Made Londen Batan, Department of Mechanical Engineering, Faculty of Industrial Technology and Systems Engineering, Institut Teknologi Sepuluh Nopember, Indonesia
Femiana Gapsari, Department of Mechanical Engineering, Faculty of Engineering, Universitas Brawijaya, Indonesia
Sze Wei Khoo, Department of Industrial Engineering, Universiti Tunku Abdul Rahman, Malaysia
DOI: https://doi.org/10.24036/teknomekanik.v8i1.33472
Abstract
Glass fiber-reinforced polymer composite materials, commonly used for industrial axial flow fan blades due to their high strength-to-weight ratio, are environmentally criticized for their non-biodegradability. This concern has prompted the investigation of eco-friendly alternatives, such as sisal and kenaf as natural fibers. Although they generally have lower mechanical properties than synthetic fibers, they offer advantages in terms of biodegradability, cost, and density. This study aims to evaluate the feasibility of partially substituting glass fiber with unidirectional natural fibers kenaf and sisal in a 14-layer GFRP axial fan blade through numerical simulation. The research employed a finite element method (FEM) to simulate tensile testing in accordance with ASTM D-638 standards. Several hybrid layer configurations were analyzed, focusing on the number and position of natural fiber layers replacing glass fiber, particularly the glass roving (GR) layers. The simulation investigated how these substitutions influence the overall tensile stress and elastic modulus of the composite blade structure. The findings suggest that this substitution does not significantly affect tensile characteristics but substantially improves the biodegradability of the composite, resulting in a more environmentally friendly material without compromising mechanical performance.
摘要
玻璃纤维增强聚合物复合材料因具有较高的强度重量比，通常用于工业轴流风机叶片，但其不可生物降解性也引发了环境方面的批评。这一问题促使研究人员探索剑麻和黄麻等天然纤维作为环保替代材料。尽管天然纤维的力学性能通常低于合成纤维，但其具有可生物降解、成本低和密度较低等优势。本研究旨在通过数值模拟，评估在14层GFRP轴流风机叶片中采用单向黄麻和剑麻天然纤维部分替代玻璃纤维的可行性。研究采用有限元法（FEM），按照ASTM D-638标准对拉伸试验进行模拟。分析了多种混合铺层配置，重点研究天然纤维层替代玻璃纤维层的数量和位置，尤其是玻璃粗纱（GR）层。模拟研究了这些替代方案对复合材料叶片结构整体拉伸应力和弹性模量的影响。研究结果表明，这种替代方式不会显著影响材料的拉伸特性，但能够显著提高复合材料的生物降解性，从而在不牺牲机械性能的情况下获得更加环保的材料。
Keywords: finite element analysis, GFRP, hybrid composite, natural fiber, tensile test
关键词： 有限元分析；GFRP；混合复合材料；天然纤维；拉伸试验
How to Cite: Wikarta, A., Andikusuma, C., Ariatedja, J., Batan, I. M. L., Gapsari, F., & Khoo, S. W. (2025). Natural fiber substitution in glass fiber-reinforced plastics: A Tensile properties simulation. Teknomekanik, 8(1), 99–116. https://doi.org/10.24036/teknomekanik.v8i1.33472
Design, simulation, and static testing of an eco-friendly prosthetic foot using ramie-PLA composite
使用苎麻纤维-PLA复合材料的环保型假肢足设计、仿真与静态测试
Iyan Sopiyan, Department of Mechanical Engineering, Faculty of Engineering, Universitas Indonesia, Indonesia
Tresna P. Soemardi, Department of Mechanical Engineering, Faculty of Engineering, Universitas Indonesia, Indonesia
Herry Purnomo, Aeronautics and Spaces Research Organization, National Research and Innovation Agency (BRIN), Indonesia
Olivier Polit, Laboratoire Energétique Mécanique Electromagnétisme, Université Paris Nanterre, France
DOI: https://doi.org/10.24036/teknomekanik.v8i1.36572
Abstract
This study developed a sustainable lower-limb prosthetic prototype using biodegradable ramie fiber-reinforced PLA composite as its primary material. The design specifically addresses the needs of individuals with limb amputation while prioritizing environmental sustainability. PLA-based composites for structural biomedical applications—particularly those in lower-limb prosthetics—must meet rigorous mechanical and fatigue performance requirements under repetitive loading. This study investigates the development of a transtibial prosthetic foot prototype using a quasi-isotropic lay-up prepreg ramie-PLA composite fabricated via the hot press method. Material characterization was conducted per ASTM standards, and the design was evaluated using the Finite Element Method (FEM). The prototype underwent static testing according to ISO 22675 with a user load criterion. The laminate exhibited an ultimate tensile strength of 48.36 ± 0.95 MPa, an elastic modulus of 4.125 ± 0.25 GPa, and a flexural strength of 62.06 ± 3.43 MPa. FEM results showed that all normal and shear stresses during heel strike (17.78 MPa and 1.71 MPa) and toe-off (12.38 MPa and 5.69 MPa) phases remained below fatigue limits. Experimental static stresses were heel strike (12.72 MPa) and toe-off (20.09 MPa), both within safe operational limits. These findings highlight the structural viability and environmental sustainability of ramie-PLA composites, positioning them as a promising material for next-generation prosthetic foot development.
摘要
本研究采用可生物降解的苎麻纤维增强PLA复合材料作为主要材料，开发了一种可持续型下肢假肢原型。该设计旨在满足截肢者的使用需求，同时优先考虑环境可持续性。用于结构生物医学应用的PLA基复合材料，尤其是下肢假肢材料，必须在重复载荷作用下满足严格的力学性能和疲劳性能要求。本研究采用通过热压法制备的准各向同性铺层预浸苎麻-PLA复合材料，开发了一种胫骨假肢足原型。材料表征按照ASTM标准进行，并采用有限元法（FEM）对设计进行评估。根据ISO 22675标准并采用用户载荷准则，对假肢原型进行了静态测试。层合板的极限拉伸强度为48.36 ± 0.95 MPa，弹性模量为4.125 ± 0.25 GPa，弯曲强度为62.06 ± 3.43 MPa。有限元分析结果表明，在足跟着地阶段，法向应力和剪切应力分别为17.78 MPa和1.71 MPa；在脚趾离地阶段，分别为12.38 MPa和5.69 MPa，所有应力均低于疲劳极限。实验静态测试得到的应力分别为足跟着地阶段12.72 MPa和脚趾离地阶段20.09 MPa，均处于安全运行范围内。这些研究结果表明，苎麻-PLA复合材料具有良好的结构可行性和环境可持续性，是下一代假肢足开发的一种具有应用前景的材料。
Keywords: ramie fibers, PLA, bio-composite, lower limb prosthetic foot, prosthetic design and development
关键词： 苎麻纤维；PLA；生物复合材料；下肢假肢足；假肢设计与开发
How to Cite: Sopiyan, I., Soemardi, T. P., Purnomo, H., & Polit, O. (2025). Design, simulation, and static testing of an eco-friendly prosthetic foot using ramie-PLA composite. Teknomekanik, 8(1), 117–135. https://doi.org/10.24036/teknomekanik.v8i1.36572
Performance analysis of soybean oil with CuO/Graphene hybrid additive nanoparticles as cutting fluid on CNC machining processes
大豆油添加CuO/石墨烯混合纳米颗粒作为切削液在CNC加工过程中的性能分析
Agus Setiawan, Mechanical Engineering Education Study Program, Universitas Pendidikan Indonesia, Indonesia
Poppy Puspitasari, Department of Mechanical and Industrial Engineering, Universitas Negeri Malang, Indonesia
Mohammad Tauviqirrahman, Department of Mechanical Engineering, Faculty of Engineering, Universitas Diponegoro, Indonesia
Diki Dwi Pramono, Centre of Advanced Material and Renewable Energy, Universitas Negeri Malang, Indonesia
Haipan Salam, Chemical Engineering Study Program, Universitas Pendidikan Indonesia, Indonesia
DOI: https://doi.org/10.24036/teknomekanik.v8i2.42472
Abstract
This study investigates the performance of soybean oil-based nano-lubricants with CuO, graphene, and CuO/graphene hybrids under MQL-assisted CNC milling of AISI 1045 steel. The research aims to evaluate the thermophysical, rheological, and tribological properties of various lubricant formulations, including pure soybean oil and soybean oil with individual or hybrid nanoparticle additives. Nanoparticles were characterized by SEM, XRD, and FTIR, and fluid samples were evaluated for density, viscosity, thermal conductivity, sedimentation stability, and rheological behavior. Machining performance was assessed through tool wear, surface roughness, cutting temperature, wear debris morphology, and chip color analysis. Results showed that adding graphene nanoparticles significantly improved machining performance, achieving a surface roughness of 1.033 µm, tool wear of 0.0493 mm, and a cutting temperature of 46.1 °C, outperforming both conventional and alternative nanofluid formulations. Among all formulations, the graphene-based nanofluid delivered the lowest cutting temperature, surface roughness, and flank wear under MQL. The CuO/graphene hybrid improved performance relative to the base fluids but did not surpass the graphene formulation, indicating limited synergistic benefits under the present soybean oil-based-MQL conditions.
摘要
本研究研究了在MQL辅助CNC铣削AISI 1045钢过程中，分别采用CuO、石墨烯以及CuO/石墨烯混合纳米颗粒的大豆油基纳米润滑剂的性能。研究旨在评估不同润滑剂配方的热物理、流变和摩擦学性能，包括纯大豆油以及添加单一或混合纳米颗粒的大豆油。采用SEM、XRD和FTIR对纳米颗粒进行表征，并对流体样品的密度、黏度、热导率、沉降稳定性和流变行为进行评价。通过刀具磨损、表面粗糙度、切削温度、磨屑形貌和切屑颜色分析对加工性能进行评估。结果表明，添加石墨烯纳米颗粒能够显著改善加工性能，表面粗糙度达到1.033 µm，刀具磨损为0.0493 mm，切削温度为46.1 °C，性能优于传统和其他替代纳米流体配方。在所有配方中，石墨烯基纳米流体在MQL条件下表现出最低的切削温度、表面粗糙度和后刀面磨损。与基础流体相比，CuO/石墨烯混合纳米流体能够改善加工性能，但其性能未超过石墨烯配方，表明在当前大豆油基MQL条件下，其协同效应有限。
Keywords: biolubricant, nanolubricant, minimum quantity lubrication, CNC milling, eco-friendly cutting fluid
关键词： 生物润滑剂；纳米润滑剂；微量润滑；CNC铣削；环保型切削液
How to Cite: Setiawan, A., Puspitasari, P., Tauviqirrahman, M., Pramono, D. D., & Salam, H. (2025). Performance analysis of soybean oil with CuO/Graphene hybrid additive nanoparticles as cutting fluid on CNC machining processes. Teknomekanik, 8(2), 136–163. https://doi.org/10.24036/teknomekanik.v8i2.42472
Investigation of corrosion, hardness, and wear rate of rice husk-zinc composite coating on A36 steel using dual anode electrolytic deposition technique
采用双阳极电解沉积技术研究稻壳-锌复合涂层在A36钢上的腐蚀、硬度和磨损率
Samuel Ajayi, Department of Mechatronics Engineering, College of Agriculture, Engineering and Science, Bowen University, Nigeria
Peter Ikubanni, Department of Mechanical Engineering, College of Engineering, Landmark University, Nigeria
Peter Onu, Department of Mechatronics Engineering, College of Agriculture, Engineering and Science, Bowen University, Nigeria
Timothy A. Adekanye, Department of Mechanical Engineering, College of Engineering, Landmark University, Nigeria
Abideen T. Oyewo, Department of Mechanical Engineering, Faculty of Engineering, Osun State University, Nigeria
Olufemi Ajide, Department of Mechanical Engineering, Faculty of Engineering, University of Ibadan, Nigeria
DOI: https://doi.org/10.24036/teknomekanik.v8i2.42172
Abstract
Zinc-bas ed composite coatings developed from synthetic ceramics (Si3N4, SiC, and Al2O3) have recently been employed as reinforcement to enhance their resistance to deterioration. However, there is limited literature on the utilization of ceramic particles sourced from agro-industrial wastes in the formulation of these coatings. This study investigated the effect of the surface improvement process (SIP) using rice husk (RH) nanoparticles on the hardness and wear rate of A36 steel. The A36 steel, zinc bar, and RH nanoparticles were procured and characterized using Energy Dispersive Spectroscopy (EDS). Four cathode specimens were produced, including an as-received specimen of A36 steel and two anodes of zinc. Four steel specimens coated with Zn-10RH(t25), Zn-10RH(t30), Zn-15RH(t25), and Zn-15RH(t30), denoted as S1, S2, S3, and S4, respectively, were developed with concentrations of 10 or 15 g/L and deposition times of 25 or 30 minutes at a constant cell voltage of 0.5 V. The as-received substrate steel was used as the control specimen (CS). The hardness and wear rate (WR) properties of the deposited samples were examined using Vickers hardness (HV) and a Pin-on-disc tribometer, respectively. All coated specimens exhibited substantial improvements in hardness and wear rate properties compared to CS (Hardness = 85.82±0.45 HV and WR = 2.45±0.34 g/min). For the coated specimens, the hardness and WR values ranged from 188.50 to 288.37 HV, 260.34 to 284.38 MPa, and 0.01 to 0.02 g/min, respectively. The inclusion of the coatings significantly enhanced the mechanical properties of the deposited specimens.
摘要
近年来，由合成陶瓷（Si3N4、SiC和Al2O3）制备的锌基复合涂层已被用作增强材料，以提高其抗劣化性能。然而，关于利用来源于农工业废弃物的陶瓷颗粒制备此类涂层的文献仍较为有限。本研究研究了采用稻壳（RH）纳米颗粒进行表面改性处理（SIP）对A36钢硬度和磨损率的影响。A36钢、锌棒和RH纳米颗粒经采购后，采用能量色散X射线光谱（EDS）进行表征。制备了四个阴极试样，其中包括一块原始状态的A36钢试样和两个锌阳极。分别制备了Zn-10RH(t25)、Zn-10RH(t30)、Zn-15RH(t25)和Zn-15RH(t30)四种涂层钢试样，分别记为S1、S2、S3和S4，其RH浓度分别为10或15 g/L，沉积时间分别为25或30分钟，恒定电池电压为0.5 V。原始状态的基体钢作为对照试样（CS）。采用维氏硬度（HV）和销盘式摩擦磨损试验机分别测试沉积试样的硬度和磨损率（WR）性能。与CS相比，所有涂层试样的硬度和磨损率性能均得到显著改善（硬度 = 85.82±0.45 HV，WR = 2.45±0.34 g/min）。对于涂层试样，其硬度和WR值分别在188.50～288.37 HV、260.34～284.38 MPa和0.01～0.02 g/min范围内。涂层的引入显著提高了沉积试样的机械性能。
Keywords: electrodeposition, rice husk, zinc-base, composite coatings, A36 steel
How to Cite: Ajayi, S., Ikubanni, P., Onu, P., Adekanye, T. A., Oyewo, A. T., & Ajide, O. (2025). Investigation of corrosion, hardness, and wear rate of rice husk-zinc composite coating on A36 steel using dual anode electrolytic deposition technique. Teknomekanik, 8(2), 164–182. https://doi.org/10.24036/teknomekanik.v8i2.42172
SIWEC-R: A rank-sensitive improvement to SIWEC methodology
SIWEC-R：一种对排名敏感的SIWEC方法改进
Do Duc Trung, School of Mechanical and Automotive Engineering, Hanoi University of Industry, Vietnam
Mehmet Özçalıcı, Kilis 7 Aralik Üniversitesi, Türkiye
Nazlı Ersoy, Osmaniye Korkut Ata University, Türkiye
Duong Van Duc, School of Mechanical and Automotive Engineering, Hanoi University of Industry, Vietnam
Nguyen Chi Bao, School of Mechanical and Automotive Engineering, Hanoi University of Industry, Vietnam
Nguyen Hoai Son, School of Mechanical and Automotive Engineering, Hanoi University of Industry, Vietnam
DOI: https://doi.org/10.24036/teknomekanik.v8i2.40172
Abstract
Determining the weights of criteria is a critical step in ranking alternatives characterized by multiple, often conflicting criteria which is a core challenge in Multi-Criteria Decision Making (MCDM). This study introduces the SIWEC-R method, a novel two-stage approach that integrates the SIWEC and R methodology to achieve more accurate and reliable weighting of criteria. Alongside the SIWEC-R method, a new performance metric, the UTAC score, was introduced to capture ranking consistency and strength across various MCDM methods. To ensure a comprehensive evaluation, sensitivity analysis was extended to cover all possible subsets of alternatives, offering an unprecedented level of scrutiny. Comparative assessments across three diverse case studies demonstrated that SIWEC-R consistently outperforms the original SIWEC method, achieving higher Spearman rank correlation coefficients and demonstrating superior robustness under sensitivity analysis. These compelling results firmly establish SIWEC-R as a significant advancement in the field of criteria weighting, delivering enhanced decision-making reliability for complex and uncertain environments.
摘要
确定准则权重是对具有多个且通常相互冲突的准则的备选方案进行排序的关键步骤，也是多准则决策（MCDM）中的核心挑战。本研究提出SIWEC-R方法，这是一种新型两阶段方法，通过整合SIWEC和R方法，实现更加准确和可靠的准则权重确定。除SIWEC-R方法外，本研究还引入了一种新的性能指标UTAC得分，用于衡量不同MCDM方法之间排名的一致性和强度。为确保全面评价，敏感性分析扩展至涵盖所有可能的备选方案子集，从而提供前所未有的分析严谨程度。通过三个不同案例研究的比较评估结果表明，SIWEC-R始终优于原始SIWEC方法，获得更高的Spearman秩相关系数，并在敏感性分析中表现出更强的稳健性。这些有力的研究结果充分证明，SIWEC-R是准则权重确定领域的一项重要进展，能够提高复杂和不确定环境下决策的可靠性。
Keywords: MCDM, SIWEC method, R method, SIWEC-R, UTAC
关键词： MCDM；SIWEC方法；R方法；SIWEC-R；UTAC
How to Cite: Trung, D. D., Özçalıcı, M., Ersoy, N., Duc, D. V., Bao, N. C., & Son, N. H. (2025). SIWEC-R: A rank-sensitive improvement to SIWEC methodology. Teknomekanik, 8(2), 183–210. https://doi.org/10.24036/teknomekanik.v8i2.40172
Optimizing vertical-axis wind turbine designs: A comparative CFD analysis of savonius, darrieus, and savonius-darrieus configurations
垂直轴风力机设计优化：Savonius、Darrieus及Savonius-Darrieus构型的CFD对比分析
Nelvi Erizon, Department of Mechanical Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Refdinal Refdinal, Department of Mechanical Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Jasman Jasman, Department of Mechanical Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Irzal Irzal, Department of Mechanical Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Yufrizal A, Department of Mechanical Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Muhammad Shadiq Fahrezi, Department of Mechanical Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Firza Fernanda, Department of Mechanical Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Egi Fadillah, Department of Mechanical Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Ma Leona Maye B. Pepito, Department of Mechanical Engineering, University of Science and Technology of Southern Philippines, Philippines
DOI: https://doi.org/10.24036/teknomekanik.v8i2.33172
Abstract
This study aims to evaluate the performance of vertical-axis wind turbines (VAWTs) with three different configurations, including Savonius, Darrieus, and a Savonius-Darrieus hybrid wind turbine, using Computational Fluid Dynamics (CFD) simulations. The methodology involves 3D geometry modeling, simulation parameter setup, meshing, and post-simulation analysis using SolidWorks 2022 software. The simulation results indicate that the Savonius turbine achieves the highest power coefficient (Cp) and torque coefficient (Ct) among the three designs, with a maximum Cp value of 0.5 at a Tip-Speed Ratio (TSR) of 0.4. Conversely, the hybrid turbine demonstrates lower efficiency, although it theoretically offers potential for improving performance at low wind speeds. Pressure and flow velocity distributions reveal that the Savonius turbine maintains the most stable pressure pattern compared to the other configurations. These findings highlight the potential of the Savonius turbine as a small-scale renewable energy solution, particularly in urban areas with low wind speeds. Further research is recommended to optimize hybrid turbine designs using machine learning approaches and empirical validation through field experiments to support the achievement of Sustainable Development Goals (SDGs), particularly Goal 7, affordable and clean energy.
摘要
本研究采用计算流体动力学（CFD）模拟，对三种不同构型的垂直轴风力机（VAWT）性能进行评估，包括Savonius、Darrieus以及Savonius-Darrieus混合型风力机。研究方法包括三维几何建模、仿真参数设置、网格划分以及使用SolidWorks 2022软件进行仿真后分析。仿真结果表明，在三种设计中，Savonius风力机具有最高的功率系数（Cp）和扭矩系数（Ct），其最大Cp值为0.5，对应的尖速比（TSR）为0.4。相比之下，混合型风力机表现出较低的效率，尽管从理论上看，其在低风速条件下具有改善性能的潜力。压力和流速分布表明，与其他构型相比，Savonius风力机能够保持最稳定的压力分布。研究结果凸显了Savonius风力机作为小型可再生能源解决方案的潜力，尤其适用于低风速的城市区域。建议未来研究采用机器学习方法进一步优化混合型风力机设计，并通过现场试验进行实验验证，以支持可持续发展目标（SDGs）的实现，特别是目标7，即经济实惠和清洁能源。
Keywords: renewable energy, aerodynamic efficiency, power coefficient, vertical axis wind turbine, computational fluid dynamics
关键词： 可再生能源；气动效率；功率系数；垂直轴风力机；计算流体动力学
How to Cite: Erizon, N., Refdinal, R., Jasman, J., Irzal, I., A, Y., Fahrezi, M. S., Fernanda, F., Fadillah, E., & Pepito, M. L. M. B. (2025). Optimizing vertical-axis wind turbine designs: A comparative CFD analysis of savonius, darrieus, and savonius-darrieus configurations. Teknomekanik, 8(2), 211–222. https://doi.org/10.24036/teknomekanik.v8i2.33172
Monitoring mission for multi-drones using decentralized chaos-bidding consensus with backstepping control via lyapunov barrier functions
基于去中心化混沌竞价共识与Lyapunov障碍函数反步控制的多无人机监测任务
Muhammad Zakiyullah Romdlony, Department of Electrical Engineering, School of Electrical Engineering, Telkom University, Indonesia
Rashad Abul Khayr, Domain of Mechanical Science and Technology, School of Science and Technology, Gunma University, Japan
Yul Yunazwin Nazaruddin, Department of Engineering Physics, Faculty of Industrial Technology, Institut Teknologi Bandung, Indonesia
Tua Agustinus Tamba, Department of Electrical Engineering, Parahyangan Catholic University, Indonesia
Md. Abdus Samad Kamal, Domain of Mechanical Science and Technology, School of Science and Technology, Gunma University, Japan
DOI: https://doi.org/10.24036/teknomekanik.v8i2.36072
Abstract
The mobility and flexibility of a quadrotor make it a popular choice for monitoring missions in remote areas. However, remote environments introduce constraints due to limited charging and communication stations that must be considered, alongside the possibility of collision with the environment. To ensure the quadrotor task was completed, a decentralized chaos-bidding consensus for decentralized task allocation was proposed, accompanied by control, Lyapunov, and barrier functions. These functions were simplified using the backstepping method to ensure the quadrotor's safety during task execution. The proposed method was evaluated through numerical simulation in multiple situations. The results indicate a minimum of 3% reduction in task completion time compared to other methods. When the battery constraint was applied, the proposed method successfully directed the drone to return to base before battery depletion and reassigned the task to other available quadrotors, thereby reducing the overall completion time for the entire system. Furthermore, this framework demonstrates the potential to support long-duration missions where continuous operation is required without relying heavily on ground control. The decentralized nature of the system also increases scalability, allowing multiple quadrotors to cooperate efficiently under dynamic environmental conditions. These advantages highlight the relevance of the proposed control strategy for practical field deployment, particularly in inaccessible locations.
摘要
四旋翼无人机具有良好的机动性和灵活性，因此成为偏远地区监测任务的常用选择。然而，偏远环境存在充电站和通信站有限等约束，需要在任务执行过程中加以考虑，同时还存在与环境发生碰撞的可能性。为确保四旋翼无人机能够完成任务，本研究提出了一种用于去中心化任务分配的去中心化混沌竞价共识方法，并结合控制函数、Lyapunov函数和障碍函数。采用反步法对这些函数进行简化，以确保四旋翼无人机在任务执行过程中的安全性。通过多种情形下的数值仿真对所提出的方法进行了评价。结果表明，与其他方法相比，该方法至少可将任务完成时间缩短3%。在施加电池约束的情况下，所提出的方法能够成功引导无人机在电池耗尽前返回基地，并将任务重新分配给其他可用的四旋翼无人机，从而减少整个系统的总体任务完成时间。此外，该框架展现出支持长时间任务的潜力，可在不高度依赖地面控制的情况下实现持续运行。系统的去中心化特性还提高了可扩展性，使多架四旋翼无人机能够在动态环境条件下实现高效协同。这些优势表明，所提出的控制策略具有实际现场部署的应用价值，尤其适用于难以到达的区域。
Keywords: UAV, safety control, backstepping method, Lyapunov barrier function, decentralized scheduling
关键词： UAV；安全控制；反步法；Lyapunov障碍函数；去中心化调度
How to Cite: Romdlony, M. Z., Khayr, R. A., Nazaruddin, Y. Y., Tamba, T. A., & Kamal, M. A. S. (2025). Monitoring mission for multi-drones using decentralized chaos-bidding consensus with backstepping control via lyapunov barrier functions. Teknomekanik, 8(2), 223–242. https://doi.org/10.24036/teknomekanik.v8i2.36072
Loading-dependent mechanical performance of alkali-treated areca nut husk fiber reinforced polyester composites modified with Uncaria gambir extract
碱处理槟榔果壳纤维增强聚酯复合材料经钩藤提取物改性后的载荷依赖性力学性能
Rahmat Azis Nabawi, Department of Mechanical Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Syahril Syahril, Department of Mechanical Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Hairul Abral, Department of Mechanical Engineering, Faculty of Engineering, Universitas Andalas, Indonesia
DOI: https://doi.org/10.24036/teknomekanik.v8i2.52472
Abstract
Natural fiber-reinforced polymer composites often experience mechanical performance limitations due to weak interfacial bonds between hydrophilic fibers and hydrophobic matrices. This study experimentally examined the effect of alkali treatment and modification using Uncaria gambir extract (UGE) on the mechanical properties and interface morphology of polyester composites reinforced with areca nut husk fiber (ANHF). Four composite configurations were prepared with a constant fiber weight fraction of 40 wt.% after alkali treatment using 6% NaOH for 24 hours, while the remaining 2 wt.% UGE was selectively applied as a fiber surface treatment, matrix additive, or a combination of both. Tensile and flexural properties were evaluated in accordance with ASTM standards, while interface morphology was examined using scanning electron microscopy (SEM). The results showed that alkali-treated composites without UGE addition had the highest tensile strength, which was attributed to increased fiber surface roughness and mechanical interlocking mechanisms. Conversely, fiber surface modification using UGE significantly increased flexural strength, indicating better stress distribution under flexural loading due to increased interface continuity. However, the addition of UGE to the matrix caused a decrease in tensile strength, which was thought to be related to a reduction in matrix stiffness. SEM observations confirm the presence of distinct interface morphology differences according to the treatment applied. These findings indicate that UGE serves primarily as a bio-based interfacial modifier, enhancing flexural performance, while its effectiveness is strongly governed by the mechanical loading mode.
摘要
天然纤维增强聚合物复合材料通常由于亲水性纤维与疏水性基体之间界面结合较弱而存在力学性能受限的问题。本研究通过实验考察了碱处理以及采用Uncaria gambir提取物（UGE）改性对槟榔果壳纤维（ANHF）增强聚酯复合材料力学性能和界面形貌的影响。经过6% NaOH碱处理24小时后，制备了四种复合材料构型，纤维质量分数保持为40 wt.%，其余2 wt.%的UGE分别选择性地用于纤维表面处理、基体添加剂处理或两者结合处理。根据ASTM标准对拉伸和弯曲性能进行了评价，并采用扫描电子显微镜（SEM）观察界面形貌。结果表明，不添加UGE的碱处理复合材料具有最高的拉伸强度，这归因于纤维表面粗糙度增加以及机械互锁机制的作用。相反，采用UGE进行纤维表面改性能够显著提高弯曲强度，表明由于界面连续性增强，在弯曲载荷作用下具有更好的应力分布。然而，将UGE添加到基体中会导致拉伸强度下降，这可能与基体刚度降低有关。SEM观察证实，不同处理方式会导致明显不同的界面形貌。这些研究结果表明，UGE主要作为一种生物基界面改性剂，通过提高界面性能增强弯曲性能，而其有效性在很大程度上取决于机械载荷模式。
Keywords: natural composites, renewable material, natural fibers, engineering materials
关键词： 天然复合材料；可再生材料；天然纤维；工程材料
How to Cite: Nabawi, R. A., Syahril, S., & Abral, H. (2025). Loading-dependent mechanical performance of alkali-treated areca nut husk fiber reinforced polyester composites modified with Uncaria gambir extract. Teknomekanik, 8(2), 243–251. https://doi.org/10.24036/teknomekanik.v8i2.52472
Trends in anti-UV films or composites: A bibliometric study
抗紫外线薄膜或复合材料的发展趋势：一项文献计量学研究
Dieter Rahmadiawan, Department of Mechanical Engineering, National Cheng Kung University, Taiwan
Thiago F. SantosPost, graduate Program in Chemical Engineering, Technology Center, Federal University of Rio Grande do Norte, Brazil
Navid Aslfattahi, Department of Fluid Dynamics and Thermodynamics, Faculty of Mechanical Engineering, Czech Technical University in Prague, Czech Republic
Shih-Chen Shi, Department of Mechanical Engineering, National Cheng Kung University, Taiwan
Eko Indrawan, Department of Mechanical Engineering, Faculty of Engineering Universitas Negeri Padang, Indonesia
Athaya Ramadhan, Laboratory of Nanoscience and Technology, Department of Mechanical Engineering, Andalas University, Indonesia
Zainal Abadi, Department of Mechanical Engineering, Faculty of Engineering Universitas Negeri Padang, Indonesia
DOI: https://doi.org/10.24036/teknomekanik.v8i2.44072
Abstract
Anti-UV films and composites play a critical role in protecting materials from ultraviolet-induced degradation, which can weaken polymers, reduce product lifespan, and compromise performance in sectors such as food packaging, outdoor coatings, and biomedical devices. The growing emphasis on sustainability and the need for environmentally friendly protective materials have further accelerated research on UV-shielding technologies that incorporate biopolymers, multifunctional additives, and renewable resources. This study presents a comprehensive bibliometric analysis of global research on anti-UV films and composites over the period 2014–2024. Data were retrieved from the Scopus database and analyzed using Bibliometrix (R package) and VOSviewer were employed to analyze publication patterns, map keyword networks, and visualize thematic evolution, as these tools enable robust quantitative and structural mapping of large bibliographic datasets. Three dominant thematic clusters were identified: (i) nanoparticle-based UV shielding using inorganic fillers such as ZnO and TiO₂, (ii) multifunctional films integrating UV protection with antibacterial and antioxidant properties, and (iii) biopolymer-based matrices emphasizing mechanical durability and environmental sustainability. These clusters highlight the convergence of performance, sustainability, and multifunctionality as key drivers shaping current research directions. Despite significant progress, the analysis reveals limited attention to scalability, industrial compatibility, and long-term performance evaluation. The findings underscore the need for future research to incorporate pilot-scale processing, life-cycle assessments, and interdisciplinary collaboration to bridge the gap between laboratory formulations and commercial implementation. Overall, this bibliometric study provides a consolidated understanding of the evolution and research landscape of anti-UV films and composites.
摘要
抗紫外线薄膜和复合材料在保护材料免受紫外线诱导的降解方面发挥着关键作用，因为紫外线降解可能导致聚合物性能下降、产品使用寿命缩短，并影响食品包装、户外涂层和生物医学器件等领域的性能。随着人们对可持续发展的日益重视以及对环保型防护材料需求的不断增加，采用生物聚合物、多功能添加剂和可再生资源的紫外线屏蔽技术研究进一步加速。本研究对2014—2024年全球抗紫外线薄膜和复合材料研究进行了全面的文献计量分析。数据从Scopus数据库中获取，并采用Bibliometrix（R package）和VOSviewer对出版模式进行分析、关键词网络进行映射以及主题演化进行可视化，这些工具能够对大规模文献数据集进行稳健的定量和结构化分析。研究确定了三个主要主题聚类：（i）采用ZnO和TiO₂等无机填料的基于纳米颗粒的紫外线屏蔽；（ii）将紫外线防护与抗菌和抗氧化性能相结合的多功能薄膜；以及（iii）强调机械耐久性和环境可持续性的生物聚合物基体。这些主题聚类表明，性能、可持续性和多功能性的融合正在成为推动当前研究方向发展的关键因素。尽管相关研究已取得显著进展，但分析显示，对于规模化生产、工业兼容性和长期性能评价的关注仍然有限。研究结果强调，未来研究需要纳入中试规模加工、生命周期评估以及跨学科合作，以弥合实验室配方与商业化应用之间的差距。总体而言，本研究通过文献计量学方法，对抗紫外线薄膜和复合材料的发展演变及其研究格局提供了系统性的认识。
Keywords: anti-UV films, composites, bibliometric analysis, VOSviewer, sustainable materials
关键词： 抗紫外线薄膜；复合材料；文献计量分析；VOSviewer；可持续材料
How to Cite: Rahmadiawan, D., Santos, T. F., Aslfattahi, N., Shi, S.-C., Indrawan, E., Ramadhan, A., & Abadi, Z. (2025). Trends in anti-UV films or composites: A bibliometric study. Teknomekanik, 8(2), 252–268. https://doi.org/10.24036/teknomekanik.v8i2.4407
Comparative analysis of bio-inspired and topology-optimized lattices under compressive loading
仿生晶格结构与拓扑优化晶格结构在压缩载荷下的对比分析
Ahmad Anas Arifin, Department of Mechanical Engineering, Institut Teknologi Sepuluh Nopember, Indonesia
I Made Londen Batan, Department of Mechanical Engineering, Institut Teknologi Sepuluh Nopember, Indonesia
Michele Bici, Department of Mechanical and Aerospace Engineering, Sapienza University of Rome, Italy
Arif Wahjudi, Department of Mechanical Engineering, Institut Teknologi Sepuluh Nopember, Indonesia
Agus Sigit Pramono, Department of Mechanical Engineering, Institut Teknologi Sepuluh Nopember, Indonesia
DOI: https://doi.org/10.24036/teknomekanik.v9i1.45472
Abstract
Lattice structure design is still dominated by strut-based forms and surface-based shapes, such as triply periodic minimal surfaces (TPMS), which both exhibit overlapping limitations. Strut lattices often show strong anisotropy because their response depends heavily on cell orientation, while TPMS lattices are difficult to adjust when bounded by geometric constraints. These conditions eventually led to stagnation in the development of lattice morphology. Hybrid and topology-optimization methods have appeared as possible alternatives, but many of them still produce modified versions of classical patterns. This study examined two lattice geometries: the Pyramorph, inspired by the shape of a pyramid, and the Topomorph, generated through a topology optimization framework. Both structures were designed using a CAD unit cell patterning technique and manufactured using the FDM method, with relative densities ranging from 0.40 to 0.44. Their mechanical behaviour was examined through FEA simulation and uniaxial compression testing. The parameter variations included cell orientations of 0°, 15°, 30°, and 45°, and cell sizes of 8 mm and 12 mm within a 24 mm specimen. The Topomorph showed superior strength, reaching 15–20 MPa, while the Pyramorph reached only 7–8 MPa. The highest value, about 20.5 MPa, was obtained from the Topomorph at 0° and with an 8 mm cell size. Failure modes indicated buckling and delamination in the Pyramorph, while the Topomorph tended to collapse progressively. These findings indicate that topology optimization combined with CAD-based patterning could significantly improve lattice performance.
摘要
晶格结构设计目前仍主要采用杆状结构和基于曲面的形态，例如三周期极小曲面（TPMS），而这两类结构均存在一些相互重叠的局限性。杆状晶格通常表现出较强的各向异性，因为其响应高度依赖于晶胞取向；而当受到几何约束时，TPMS晶格则难以进行调整。这些因素最终导致晶格形态的发展陷入停滞。混合方法和拓扑优化方法已成为潜在的替代方案，但其中许多方法仍然只是对经典结构形式进行修改。本研究考察了两种晶格几何结构：受金字塔形状启发的Pyramorph，以及通过拓扑优化框架生成的Topomorph。两种结构均采用CAD晶胞阵列技术进行设计，并通过FDM方法制造，相对密度范围为0.40～0.44。通过FEA仿真和单轴压缩试验对其力学行为进行了研究。参数变化包括0°、15°、30°和45°的晶胞取向，以及在24 mm试样中采用8 mm和12 mm的晶胞尺寸。Topomorph表现出更高的强度，达到15～20 MPa，而Pyramorph的强度仅为7～8 MPa。最高值约为20.5 MPa，出现在0°取向且晶胞尺寸为8 mm的Topomorph中。失效模式表明，Pyramorph主要发生屈曲和分层，而Topomorph则倾向于发生渐进式塌陷。这些研究结果表明，将拓扑优化与基于CAD的阵列设计相结合能够显著提高晶格结构的性能。
Keywords: lattice structures, topology optimization, compressive behaviour, material engineering
How to Cite: Arifin, A. A., Batan, I. M. L., Bici, M., Wahjudi, A., & Pramono, A. S. (2026). Comparative analysis of bio-inspired and topology-optimized lattices under compressive loading. Teknomekanik, 9(1), 1–24. https://doi.org/10.24036/teknomekanik.v9i1.45472
Multiclass gas pipeline leak detection using multi-domain signals and genetic algorithm-optimized classification models
基于多域信号与遗传算法优化分类模型的多类别天然气管道泄漏检测
Wiwit Suprihatiningsih, Department of Mechanical Engineering, Universitas Mercu Buana, Indonesia
Dedik Romahadi, School of Mechanical Engineering, Beijing Institute of Technology, China
Hadi Pranoto, Department of Mechanical Engineering, Universitas Mercu Buana, Indonesia
Rikko Putra Youlia, Department of Mechanical Engineering, Universitas Mercu Buana, Indonesia
Fajar Anggara, Department of Mechanical Engineering, Universitas Mercu Buana, Indonesia
Rizky Rahmatullah, School of Integrated Circuits and Electronics, Beijing Institute of Technology, China
DOI: https://doi.org/10.24036/teknomekanik.v9i1.38372
Abstract
Pipeline networks are critical infrastructure for oil and gas transport because the occurrence of leaks can rapidly escalate into safety, economic, and environmental crises. Operators are practically required to identify the presence and type of leaks; however, applying multiclass recognition is challenging when labeled data and computing power are limited. Therefore, this study proposes a three-stage pipeline which consists of: (1) adopting the GPLA-12 dataset of acoustic or vibration signals spanning 12 leak types; (2) extracting multi-domain features by combining time-domain descriptors with Power Spectral Density (PSD)-based spectral features; and (3) applying a genetic algorithm (GA) as a wrapper for feature selection to enhance discriminability and reduce dimensionality, which was followed by benchmarking seven conventional classifiers and GA-based refinement of the top model with a focus on the feature subset and hyperparameters. A maximum accuracy of 96.35% was achieved on the GPLA-12 dataset with low computation time and a simple model architecture. The proposed pipeline also attained similar or better accuracy at substantially lower complexity and data requirements compared with prior deep CNN approaches. These results support timely multiclass decision-making in resource-constrained industrial settings. A key observation was that the focus was on supervised leak-type classification from acoustic or vibration signals, while localization, severity estimation, and multi-sensor fusion were beyond the scope of this study.
摘要
管道网络是油气运输的重要基础设施，因为泄漏事故可能迅速演变为安全、经济和环境危机。实际运行中，操作人员需要识别泄漏的存在及其类型；然而，当标注数据和计算能力有限时，多类别识别的应用具有较大挑战。因此，本研究提出了一种由三个阶段组成的管道泄漏检测流程：（1）采用GPLA-12数据集，该数据集包含涵盖12种泄漏类型的声学或振动信号；（2）提取多域特征，将时域描述符与基于功率谱密度（PSD）的频谱特征相结合；（3）采用遗传算法（GA）作为特征选择的包装器，以提高特征的可辨识性并降低维度，随后对七种传统分类器进行基准测试，并利用GA对性能最佳的模型进行进一步优化，重点关注特征子集和超参数。在GPLA-12数据集上，该方法获得了最高96.35%的准确率，同时具有较低的计算时间和简单的模型架构。与此前的深度CNN方法相比，所提出的流程在显著降低复杂度和数据需求的情况下，也获得了相当或更高的准确率。这些结果支持资源受限工业环境下及时开展多类别决策。需要指出的是，本研究重点关注基于声学或振动信号的监督式泄漏类型分类，而泄漏定位、泄漏严重程度估计以及多传感器融合不属于本研究的研究范围。
Keywords: gas pipeline leak detection, multiclass classification, acoustic signal, genetic algorithm
关键词： 天然气管道泄漏检测；多类别分类；声学信号；遗传算法
How to Cite: Suprihatiningsih, W., Romahadi, D., Pranoto, H., Youlia, R. P., Anggara, F., & Rahmatullah, R. (2026). Multiclass gas pipeline leak detection using multi-domain signals and genetic algorithm-optimized classification models. Teknomekanik, 9(1), 25–41. https://doi.org/10.24036/teknomekanik.v9i1.38372
Grid convergence analysis of an H-Darrieus wind turbine for multiple blade configurations
多叶片构型H-Darrieus风力机的网格收敛性分析
Sanjaya Baroar Sakti Nasution, Department of Mechanical Engineering, Faculty of Engineering, Universitas Sumatera Utara, Indonesia
Dian Morfi Nasution, Department of Mechanical Engineering, Faculty of Engineering, Universitas Sumatera Utara, Indonesia
Elang Pramudya Wijaya, Mechanical Engineering Study Program, IPB University, Indonesia
Oki Suprada Ompusunggu, Department of Mechanical Engineering, Faculty of Engineering, Universitas Sumatera Utara, Indonesia
DOI: https://doi.org/10.24036/teknomekanik.v9i1.45272
Abstract
Mesh size and number significantly affected the accuracy of CFD simulations in wind turbine analysis. However, most studies focused solely on turbine performance, such as the blade torque or power coefficients. Therefore, this study adopted a broader perspective by analyzing the influence of mesh resolution on both aerodynamic performance and key fluid-dynamic parameters, including vorticity and pressure coefficients, for an H-type Darrieus vertical-axis wind turbine. Two-dimensional CFD simulations were performed using ANSYS Fluent with the k–ω SST turbulence model. Five mesh levels were evaluated across different blade configurations, and the Grid Convergence Index (GCI) was used to quantify discretization errors. The results indicate that increasing mesh resolution yields more stable torque predictions and improved resolution of near-wall flow features, with consistent grid-convergence behaviour observed across all blade configurations. GCI analysis shows that discretization errors consistently decrease as the mesh becomes finer. It also shows that a grid size of about 1.6 x 105 cells is sufficient to keep errors below 5%. These findings show that including flow-field details in mesh sensitivity analysis gives a better way to check the accuracy of CFD simulations for Darrieus wind turbines.
摘要
网格尺寸和数量会显著影响风力机分析中CFD模拟的准确性。然而，大多数研究仅关注风力机性能，例如叶片扭矩或功率系数。因此，本研究采用更为全面的视角，分析网格分辨率对H型Darrieus垂直轴风力机气动性能以及关键流体动力学参数的影响，包括涡量和压力系数。采用ANSYS Fluent软件和k–ω SST湍流模型进行二维CFD模拟。在不同叶片构型下评估了五个网格等级，并采用网格收敛指数（GCI）量化离散误差。结果表明，提高网格分辨率能够获得更加稳定的扭矩预测结果，并改善近壁面流动特征的分辨率，同时在所有叶片构型中均观察到一致的网格收敛行为。GCI分析表明，随着网格逐渐加密，离散误差持续降低。分析还表明，约1.6 x 105个单元的网格尺寸足以将误差控制在5%以下。这些研究结果表明，在网格敏感性分析中纳入流场细节，能够为检验Darrieus风力机CFD模拟的准确性提供更好的方法。
Keywords: CFD, Darrius wind turbine, grid convergence index, vorticity
关键词： CFD；Darrieus风力机；网格收敛指数；涡量
How to Cite: Nasution, S. B. S., Nasution, D. M., Wijaya, E. P., & Ompusunggu, O. S. (2026). Grid convergence analysis of an H-Darrieus wind turbine for multiple blade configurations. Teknomekanik, 9(1), 42–59. https://doi.org/10.24036/teknomekanik.v9i1.45272
Spatial modelling of shallow groundwater quality in coastal areas with Kriging interpolation
采用克里金插值的沿海地区浅层地下水水质空间建模
Yaumal Arbi, Doctoral Program of Environmental Science, Universitas Negeri Padang, Indonesia
Nurhasan Syah, Department of Civil Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Iswandi Umar, Department of Geography, Universitas Negeri Padang, Indonesia
Indang Dewata, Department of Chemistry, Universitas Negeri Padang, Indonesia
Mulya Gusman, Department of Mining Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Nevy Sandra, Department of Civil Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
DOI: https://doi.org/10.24036/teknomekanik.v9i1.47272
Abstract
This study maps shallow coastal groundwater quality in Padang, Indonesia, using four operational parameters: potential of hydrogen (pH), electrical conductivity (EC), total dissolved solids (TDS), and salinity. We characterize spatial dependence using empirical variograms, evaluate directional anisotropy, and generate prediction surfaces with Ordinary Kriging. The variogram analysis indicates stronger spatial continuity along the coastline for EC and TDS, while salinity shows shorter continuity with a distinct directional structure, reflecting localized freshwater-seawater mixing processes. Groundwater pH remains neutral to slightly alkaline and exhibits lower spatial variability than EC, TDS, and salinity. Leave-one-out cross-validation supports the reliability of the kriging estimates at the study scale, indicating low prediction error and strong agreement between observed and predicted values. The resulting thematic maps enable a three-level quality zoning that differentiates a lower-risk northern segment, a transitional central belt, and a higher-risk southern segment consistent with seawater intrusion influence. These outputs provide a practical basis for prioritizing monitoring locations, protecting vulnerable wells, and strengthening evidence-based coastal groundwater management aligned with SDG 6 Clean Water and Sanitation and SDG 11 Sustainable Cities and Communities.
摘要
本研究采用四项运行参数——氢离子浓度指数（pH）、电导率（EC）、总溶解固体（TDS）和盐度，对印度尼西亚巴东沿海浅层地下水水质进行空间制图。研究利用经验变异函数表征空间依赖性，评估方向异质性，并采用普通克里金（Ordinary Kriging）生成预测表面。变异函数分析表明，EC和TDS沿海岸线方向具有更强的空间连续性，而盐度表现出较短的空间连续性及明显的方向性结构，这反映了局部淡水-海水混合过程。地下水pH保持中性至弱碱性，其空间变异性低于EC、TDS和盐度。留一交叉验证结果支持研究尺度下克里金估计的可靠性，表明预测误差较低，且观测值与预测值之间具有较高的一致性。所得专题地图实现了三级水质分区，将研究区域划分为北部低风险区、中部过渡带和南部高风险区，这与海水入侵影响的分布特征相一致。这些成果为确定监测点优先级、保护脆弱水井以及加强基于证据的沿海地下水管理提供了实践基础，并与可持续发展目标（SDG）6“清洁饮水和卫生设施”和SDG 11“可持续城市和社区”相一致。
Keywords: coastal groundwater, seawater intrusion, ordinary kriging, clean water and sanitation, sustainable and communities
关键词： 沿海地下水；海水入侵；普通克里金；清洁饮水和卫生设施；可持续发展和社区
How to Cite: Arbi, Y., Syah, N., Umar, I., Dewata, I., Gusman, M., & Sandra, N. (2026). Spatial modelling of shallow groundwater quality in coastal areas with Kriging interpolation. Teknomekanik, 9(1), 60–76. https://doi.org/10.24036/teknomekanik.v9i1.47272
Optimization of bio-based cellulose-phosphate hydrogel production from rice husk waste using the Taguchi method
采用Taguchi方法优化稻壳废弃物制备生物基纤维素-磷酸盐水凝胶
Selvia Aprilyanti, Department of Industrial Engineering, Faculty of Engineering, Universitas Tridinanti, Indonesia
Irnanda Pratiwi, Department of Industrial Engineering, Faculty of Engineering, Universitas Tridinanti, Indonesia
Winny Andalia, Department of Industrial Engineering, Faculty of Engineering, Universitas Tridinanti, Indonesia
Tine Aprianti, Department of Chemical Engineering, School of Engineering, The University of Western Australia, Australia
Hariman Al Faritzie, Department of Civil Engineering, Faculty of Engineering, Universitas Tridinanti, Indonesia
DOI: https://doi.org/10.24036/teknomekanik.v9i1.47172
Abstract
This work reports the development and statistical optimization of a fully Bio-based absorbent hydrogel synthesized from rice husk–derived cellulose via phosphoric acid crosslinking. Cellulose was extracted through sequential chemical treatments and subsequently converted into a phosphate-crosslinked hydrogel using a controlled synthesis process. A Taguchi L16 (4⁵) orthogonal array was employed to optimize four key synthesis parameters: cellulose content, reaction time, heating temperature, and phosphoric acid volume. Hydrogel structure and morphology were characterized using Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). FTIR results confirmed the formation of phosphate ester linkages, indicating successful crosslinking, while SEM observations revealed a porous and interconnected network structure favorable for water absorption. The optimized hydrogel formulation achieved a maximum swelling ratio of 91.25 g/g, demonstrating effective absorbent performance despite the absence of synthetic monomers or grafting agents. These findings indicate that rice husk waste can be efficiently valorized into an environmentally benign absorbent material through a simple and statistically guided synthesis route, supporting sustainable hydrogel development and agricultural waste utilization.
摘要
本研究报道了采用磷酸交联法，以稻壳衍生纤维素为原料制备完全生物基吸水水凝胶，并对其进行统计优化。纤维素通过连续化学处理进行提取，随后采用受控合成工艺转化为磷酸盐交联水凝胶。采用Taguchi L16（4⁵）正交试验设计，对四个关键合成参数进行优化，包括纤维素含量、反应时间、加热温度和磷酸体积。采用傅里叶变换红外光谱（FTIR）和扫描电子显微镜（SEM）对水凝胶的结构和形貌进行表征。FTIR结果证实了磷酸酯键的形成，表明交联成功；SEM观察显示水凝胶具有有利于吸水的多孔互连网络结构。优化后的水凝胶配方实现了91.25 g/g的最大溶胀比，尽管未使用合成单体或接枝剂，仍表现出良好的吸水性能。这些研究结果表明，通过简单且具有统计学指导的合成路线，可以将稻壳废弃物高效转化为环境友好型吸水材料，为可持续水凝胶开发和农业废弃物资源化利用提供支持。
Keywords: cellulose, extraction, hydrogel, rice husk, Taguchi method
关键词： 纤维素；提取；水凝胶；稻壳；Taguchi方法
How to Cite: Aprilyanti, S., Pratiwi, I., Andalia, W., Aprianti, T., & Faritzie, H. A. (2026). Optimization of bio-based cellulose-phosphate hydrogel production from rice husk waste using the Taguchi method. Teknomekanik, 9(1), 77–90. https://doi.org/10.24036/teknomekanik.v9i1.47172
Effects of process parameters on the evaporative pattern casting of scrap aluminum–RHA composites
工艺参数对废铝–RHA复合材料消失模铸造的影响
Rudi Siswanto, Department of Mechanical Engineering, Faculty of Engineering, Universitas Lambung Mangkurat, Indonesia
Abdul Ghofur, Department of Mechanical Engineering, Faculty of Engineering, Universitas Lambung Mangkurat, Indonesia
Rachmat Subagyo, Department of Mechanical Engineering, Faculty of Engineering, Universitas Lambung Mangkurat, Indonesia
Mastiadi Tamjidillah, Department of Mechanical Engineering, Faculty of Engineering, Universitas Lambung Mangkurat, Indonesia
Mahmud Mahmud, Department of Environmental Engineering, Faculty of Engineering, Universitas Lambung Mangkurat, Indonesia
Ma’ruf Ma’ruf, Department of Mechanical Engineering, Faculty of Engineering, Universitas Lambung Mangkurat, Indonesia
Adi Nordiman, Department of Mechanical Engineering, Faculty of Engineering, Universitas Lambung Mangkurat, Indonesia
DOI: https://doi.org/10.24036/teknomekanik.v9i1.46072
Abstract
This study investigates the fabrication and characterization of aluminium matrix composites reinforced with rice husk ash (RHA), using scrap aluminium as the base material and evaporative pattern casting as the manufacturing method. The work evaluates the effects of three key independent variables: pouring temperature, aluminium (Al)-RHA composition ratios, and styrofoam pattern thickness on the resulting composite properties. The dependent variables examined include surface roughness, Brinell hardness, and dimensional shrinkage-expansion. Experimental results show that increasing the pouring temperature and adjusting the composition ratio significantly influence the mechanical and physical properties of the composites. The highest hardness (45.6 HB) and fluidity (252.65 mm) were achieved at a 60:40 composition ratio and a pouring temperature of 750 °C, albeit at the cost of increased porosity. Additionally, the styrofoam pattern thickness was found to affect the dimensional stability and surface roughness of the composites, with thicker patterns resulting in higher surface roughness. This study highlights the potential of utilizing rice husk ash as a reinforcing material in aluminium matrix composites, offering a sustainable approach to improving material properties. The findings suggest that an optimal balance of composition ratio, pouring temperature, and pattern thickness is crucial to achieving desirable mechanical and physical characteristics, with implications for advanced manufacturing processes in the materials industry.
摘要
本研究采用废铝作为基体材料，并以消失模铸造作为制造方法，研究和表征稻壳灰（RHA）增强铝基复合材料的制备过程及性能。研究评估了三个关键自变量对复合材料性能的影响，包括浇注温度、铝（Al）-RHA组成比例以及聚苯乙烯泡沫（styrofoam）模型厚度。考察的因变量包括表面粗糙度、布氏硬度以及尺寸收缩-膨胀。实验结果表明，提高浇注温度和调整组成比例会显著影响复合材料的机械性能和物理性能。在Al-RHA组成比例为60:40、浇注温度为750 °C的条件下，获得了最高硬度45.6 HB和流动性252.65 mm，但同时伴随着孔隙率增加。此外，聚苯乙烯泡沫模型厚度会影响复合材料的尺寸稳定性和表面粗糙度，较厚的模型会导致更高的表面粗糙度。本研究凸显了利用稻壳灰作为铝基复合材料增强材料的潜力，为改善材料性能提供了一种可持续的方法。研究结果表明，组成比例、浇注温度和模型厚度之间的最佳平衡对于获得理想的机械和物理性能至关重要，并可为材料工业中的先进制造工艺提供参考。
Keywords: evaporative casting, Al-RHA composite, pouring temperature, pattern thickness, physical-mechanical properties
关键词： 消失模铸造；Al-RHA复合材料；浇注温度；模型厚度；物理-机械性能
How to Cite: Siswanto, R., Ghofur, A., Subagyo, R., Tamjidillah, M., Mahmud, M., Ma’ruf, M., & Nordiman, A. (2026). Effects of process parameters on the evaporative pattern casting of scrap aluminum–RHA composites. Teknomekanik, 9(1), 91–109. https://doi.org/10.24036/teknomekanik.v9i1.46072
Hydrodynamic optimization of a Sweptback Stern Foil for resistance reduction in flat-hull ships: A CFD-based extension of the Hull Vane concept
平底船减阻用后掠艉部翼的水动力优化：基于CFD的Hull Vane概念扩展
Rahmat Azis Nabawi, Department of Mechanical Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Budi Syahri, Department of Mechanical Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Yogi Dian Alfana, Department of Mechanical Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Donny Fernandez, Department of Automotive Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
DOI: https://doi.org/10.24036/teknomekanik.v9i1.54872
Abstract
Flat-hull ships are known to have higher resistance than streamlined hulls. Although the Hull Vane® concept has been proven effective as a stern-mounted energy-saving device through pressure-field modification and stern-wave interaction, most previous studies have focused on straight-foil configurations (straight planform). The effect of planform shape optimization, particularly the sweptback configuration, on the hydrodynamic performance of flat-hull ships is limited in the literature. This study modifies the geometry of a Hull Vane® into a sweptback stern foil and evaluates its performance using Computational Fluid Dynamics simulations. The results show that a 15° sweptback angle yields the greatest reduction in total drag. Velocity contour analysis shows a narrower wake and a more uniform velocity-gradient distribution in the stern area for the 15° swept-back stern-foil configuration compared to other configurations. Meanwhile, the turbulence length distribution shows a tendency toward reduced intensity of large-scale turbulent structures behind the ship, indicating improved wake-flow characteristics. The identified drag reduction mechanism primarily stems from improved pressure recovery and modified pressure distribution in the stern area, which is consistent with the working principle of Hull Vane®. Optimizing the sweptback planform geometry yields more efficient flow interaction than the straight-foil configuration. These findings indicate that planform optimization is an important design parameter in the development of stern foils to improve the hydrodynamic efficiency of medium-to high-speed commercial vessels.
摘要
众所周知，平底船的阻力高于流线型船体。尽管Hull Vane®概念通过改变压力场和与船尾波相互作用，已被证明是一种有效的船尾安装式节能装置，但以往大多数研究主要集中于直翼型构型（直线平面形）。关于平面形状优化，尤其是后掠构型对平底船水动力性能影响的研究在现有文献中仍较为有限。本研究将Hull Vane®的几何形状改进为后掠艉部翼，并采用计算流体力学（CFD）模拟对其性能进行评估。结果表明，15°后掠角能够实现最大的总阻力降低。速度云图分析显示，与其他构型相比，15°后掠艉部翼构型在船尾区域形成了更窄的尾流以及更加均匀的速度梯度分布。同时，湍流长度分布显示船后大型湍流结构的强度呈降低趋势，表明尾流特性得到改善。所识别的减阻机制主要源于船尾区域压力恢复性能的改善以及压力分布的改变，这与Hull Vane®的工作原理一致。优化后掠平面形状能够实现比直翼构型更高效的流动相互作用。这些研究结果表明，平面形状优化是船尾翼开发中的重要设计参数，可用于提高中高速商用船舶的水动力效率。
Keywords: flat-hull ship, flow simulation, energy-saving device, affordable and clean energy, ship resistance reduction
关键词： 平底船；流动模拟；节能装置；经济适用的清洁能源；船舶减阻
Keywords: flat-hull ship, flow simulation, energy-saving device, affordable and clean energy, ship resistance reduction
关键词： 平底船；流动模拟；节能装置；经济适用的清洁能源；船舶减阻
How to Cite: Nabawi, R. A., Syahri, B., Alfana, Y. D., & Fernandez, D. (2026). Hydrodynamic optimization of a Sweptback Stern Foil for resistance reduction in flat-hull ships: A CFD-based extension of the Hull Vane concept. Teknomekanik, 9(1), 110–120. https://doi.org/10.24036/teknomekanik.v9i1.54872
Uniaxial and biaxial hot pressing of PVDF films: A pathway toward high-performance piezoelectric sensors and energy harvesters
PVDF薄膜的单轴与双轴热压：通向高性能压电传感器和能量采集器的途径
Suprapto Suprapto, Department of Mechanical Engineering, Universitas Negeri Medan, Indonesia
Jubaidah, Department of Mechanical Engineering, Universitas Negeri Medan, Indonesia
Selamat Triono, Department of Mechanical Engineering, Universitas Negeri Medan, Indonesia
Harianto Gunawan, Department of Mechanical Engineering, Chung Yuan Christian University, Taiwan
Lisyanto Lisyanto, Department of Mechanical Engineering, Universitas Negeri Medan, Indonesia
Aditya Sukma Nugraha, National Research and Innovation Agency (BRIN), Indonesia
Yopan rahmad Aldori, Department of Mechanical Engineering, Universitas Medan Area, Indonesia
DOI: https://doi.org/10.24036/teknomekanik.v9i1.44972
Abstract
The piezoelectric efficiency of Poly (vinylidene fluoride) (PVDF) membranes becomes restricted by the challenge of generating and stabilizing electroactive β-phase during processing. Stretching requires control of deformation parameter, while solvent-based methods bring environmental and occupational health risks. This research suggests hot-pressing as an alternative method for enhancing β-phase fraction, utilizing multidirectional stress without solvent or chemical exposure. This study systematically compares uniaxial hot-pressing (Uniaxial HP) and biaxial hot-pressing (Biaxial HP) setups to determine which stress distribution is more effective at promoting changes and improving piezoelectric properties in PVDF membranes. The main objective of this research is to systematically evaluate and compare the impacts of uniaxial and biaxial hot-pressing on the crystalline phase transformation and electromechanical performance, including the piezoelectric coefficient (d33) and output voltage response of PVDF membranes. PVDF pellets were hot-pressed at 220o C under a pressure of 60 MPa for 15 minutes followed by rapid quenching in ice water. X-Ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) confirmed phase composition, correlated with performance via the piezoelectric coefficient (d33), and assessed piezoelectric activity. Experimental results show that biaxial loading provides a higher b-phase fraction (50.47%) compared to untreated membranes (47.80%) and UHP samples (49.30%). The crystallinity and the piezoelectric coefficient also increased to 49% and 18.8 pC/N, respectively. Biaxial stress pattern during hot-pressing induces favourable thermodynamic and kinetic conditions for b-phase expansion. Beyond phase-related results, the approach delivers competitive piezoelectric effectiveness while maintaining simplicity and reducing solvent-dependent processing steps.
摘要
聚偏二氟乙烯（PVDF）膜的压电效率受到加工过程中生成并稳定电活性β相这一挑战的限制。拉伸过程需要控制变形参数，而基于溶剂的方法则会带来环境和职业健康风险。本研究提出热压作为提高β相含量的一种替代方法，通过施加多方向应力，在无需使用溶剂或接触化学物质的情况下实现β相含量的提升。本研究系统比较了单轴热压（Uniaxial HP）和双轴热压（Biaxial HP）两种工艺，以确定哪种应力分布更有利于促进PVDF膜的相变并改善其压电性能。本研究的主要目标是系统评估和比较单轴与双轴热压对PVDF膜晶体相变和机电性能的影响，包括压电系数（d33）和输出电压响应。PVDF颗粒在220o C、60 MPa压力下热压15分钟，随后在冰水中快速淬冷。采用X射线衍射（XRD）和傅里叶变换红外光谱（FTIR）对相组成进行确认，并通过压电系数（d33）与性能建立关联，同时评估压电活性。实验结果表明，双轴加载获得了更高的β相含量（50.47%），高于未经处理的膜（47.80%）和UHP样品（49.30%）。结晶度和压电系数也分别提高至49%和18.8 pC/N。热压过程中的双轴应力模式为β相扩展诱导了有利的热力学和动力学条件。除相组成相关结果外，该方法在保持工艺简便性的同时实现了具有竞争力的压电性能，并减少了对溶剂依赖的加工步骤。
Keywords: PVDF, uniaxial and biaxial, hot press, piezoelectric
How to Cite: Suprapto, S., jubaidah, J., Triono, S., Gunawan, H., Lisyanto, L., Nugraha, A. S., & Aldori, Y. rahmad. (2026). Uniaxial and biaxial hot pressing of PVDF films: A pathway toward high-performance piezoelectric sensors and energy harvesters. Teknomekanik, 9(1), 121–136. https://doi.org/10.24036/teknomekanik.v9i1.44972
Comparative study on the corrosion behavior of TiCN-coated austenitic and ferritic stainless steels in geothermal environments
TiCN涂层奥氏体和铁素体不锈钢在地热环境中的腐蚀行为对比研究
Agus Solehudin, Study Program of Chemical Engineering, Faculty of Engineering and Industrial Education, Universitas Pendidikan Indonesia, Indonesia
Haipan Salam, Study Program of Chemical Engineering, Faculty of Engineering and Industrial Education, Universitas Pendidikan Indonesia, Indonesia
Enda Permana, Study Program of Mechanical Engineering Education, Faculty of Engineering and Industrial Education, Universitas Pendidikan Indonesia, Indonesia
Atiek Rostika Noviyanti, Study Program of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Padjajaran, Indonesia
Akrajas Ali Umaar, Institute of Microengineering and Nanoelectronics, Universiti Kebangsaan Malaysia, Malaysia
Risti Ragadhita, Study Program of Chemical Engineering, Faculty of Engineering and Industrial Education, Universitas Pendidikan Indonesia, Indonesia
DOI: https://doi.org/10.24036/teknomekanik.v9i2.44172
Abstract
Corrosion in stainless steel (SS) remains a critical limitation for its application, particularly in harsh environments such as geothermal systems. This study aims to evaluate the corrosion resistance of two SS substrates, namely SS 11-0 (ferritic) and SS 18-8 (austenitic), used as drill bit materials, both before and after the application of a TiCN protective coating. The coating was deposited by Physical Vapor Deposition (PVD) for 15, 25, and 35 minutes at 250°C. Corrosion resistance was assessed using a salt spray test with a 5% NaCl solution (pH 6–7) for 100 hours to simulate a neutral corrosive environment. Surface morphology and elemental composition were characterized using Field Emission Scanning Electron Microscopy–Energy Dispersive X-ray Spectroscopy (FESEM–EDS), while coating thickness and hardness were evaluated using Fischerscope® X-RAY XAN and Vickers microhardness testing, respectively. Corrosion performance was quantitatively analyzed using mass-loss-based corrosion rate calculations and polarization resistance measurements with a potentiostat instrument, providing insights into the electrochemical behavior of the coating–substrate system. The results demonstrate that increasing deposition time enhances coating thickness and overall coating quality. FESEM–EDS analysis confirms the successful formation of the TiCN layer and reveals changes in surface morphology and elemental composition after coating and corrosion exposure. Among the tested substrates, SS 18-8 consistently exhibits superior hardness, surface uniformity, and corrosion resistance compared to SS 11-0. Based on the weight loss method, the corrosion rates of uncoated and TiCN-coated SS 18-8 are 0.2600 mm/year and 0.1625 mm/year, respectively, both lower than those observed for SS 11-0. This enhanced performance is attributed to the synergistic effect between the TiCN coating and the Cr- and Ni-rich chemical composition of SS 18-8, which facilitates the formation of a stable and protective passive layer. These findings highlight the strong potential of TiCN-coated SS 18-8 for applications in geothermal environments under neutral corrosive conditions.
摘要
不锈钢（SS）的腐蚀问题仍然是限制其应用的关键因素，尤其是在地热系统等恶劣环境中。本研究旨在评估两种不锈钢基材，即SS 11-0（铁素体）和SS 18-8（奥氏体）作为钻头材料时，在施加TiCN保护涂层前后的耐腐蚀性能。采用物理气相沉积（PVD）方法，在250°C条件下分别沉积15、25和35分钟形成涂层。采用5% NaCl溶液（pH 6–7）进行盐雾试验，持续100小时，以模拟中性腐蚀环境，从而评估材料的耐腐蚀性能。采用场发射扫描电子显微镜-能量色散X射线光谱（FESEM–EDS）对表面形貌和元素组成进行表征，同时分别采用Fischerscope® X-RAY XAN和维氏显微硬度测试评估涂层厚度和硬度。通过基于失重法的腐蚀速率计算以及采用恒电位仪进行的极化电阻测量，对腐蚀性能进行定量分析，从而揭示涂层-基材体系的电化学行为。结果表明，延长沉积时间能够提高涂层厚度和整体涂层质量。FESEM–EDS分析证实TiCN层成功形成，并揭示了涂层处理及腐蚀暴露后表面形貌和元素组成的变化。在所测试的基材中，SS 18-8始终表现出优于SS 11-0的硬度、表面均匀性和耐腐蚀性能。根据失重法，未涂层和TiCN涂层SS 18-8的腐蚀速率分别为0.2600 mm/year和0.1625 mm/year，均低于SS 11-0对应的腐蚀速率。这种性能提升归因于TiCN涂层与SS 18-8富含Cr和Ni的化学组成之间的协同作用，该作用促进了稳定且具有保护作用的钝化层形成。这些研究结果表明，TiCN涂层SS 18-8在中性腐蚀条件下的地热环境应用中具有良好的应用潜力。
Keywords: corrosion resistance, geothermal condition, PVD, polarization resistance, stainless steel, weight loss
关键词： 耐腐蚀性；地热条件；PVD；极化电阻；不锈钢；失重
How to Cite: Solehudin, A., Salam, H., Permana, E., Noviyanti, A. R., Umaar, A. A., & Ragadhita, R. (2026). Comparative study on the corrosion behavior of TiCN-coated austenitic and ferritic stainless steels in geothermal environments. Teknomekanik, 9(2), 137–161. https://doi.org/10.24036/teknomekanik.v9i2.44172
The effect of T6 heat treatment on the tensile, impact, and fatigue properties of Al6061-fly ash composites
T6热处理对Al6061-粉煤灰复合材料拉伸、冲击和疲劳性能的影响
Zainun Achmad, Department of Mechanical Engineering, Faculty of Engineering, Universitas 17 Agustus 1945 Surabaya, Indonesia
Al Emran bin Ismail, Faculty of Mechanical and Manufacturing Engineering, Universiti Tun Hussein Onn Malaysia, Malaysia
Harjo Seputro, Department of Mechanical Engineering, Faculty of Engineering, Universitas 17 Agustus 1945 Surabaya, Indonesia
Eka Marliana, Department of Mechanical Engineering, Faculty of Engineering, Universitas 17 Agustus 1945 Surabaya, Indonesia
DOI: https://doi.org/10.24036/teknomekanik.v9i2.50672
Abstract
This study investigates the effect of controlled precipitation hardening on the mechanical behavior of Al6061–fly ash metal matrix composites fabricated using stir casting and subjected to T6 heat treatment. The specimens underwent solution treatment at 510°C for 1 and 2 hours, followed by oil quenching and artificial aging at 120°C, 140°C, and 160°C for 2 hours. Tensile, Rockwell hardness, impact, and fatigue tests were used to assess the mechanical characteristics, in accordance with ASTM standards, and were supported by microstructural and SEM studies. The findings indicate that T6 treatment greatly improves strength and fatigue tolerance compared with the untreated state. The highest tensile strength and impact energy were achieved under the T6-A2 condition (510 °C for 2 h + aging at 120 °C for 2 h), whereas the longest fatigue life was obtained under the T6-B1 condition (510 °C for 1 h + aging at 140 °C for 2 h). This shows a good balance between strength and toughness, which is related to the formation of fine Mg2Si precipitates and enhanced interfacial bonding. Aging at 120°C resulted in the highest hardness at 510°C (2 hours). Over-aging reduced ductility and impact resistance because of precipitate coarsening. For durable aluminum–fly ash composites, these results show a distinct link between processing, microstructure, and material characteristics.
摘要
本研究采用搅拌铸造法制备Al6061–粉煤灰金属基复合材料，并进行T6热处理，研究受控析出硬化对其力学行为的影响。试样分别在510°C下进行1小时和2小时的固溶处理，随后进行油淬，并在120°C、140°C和160°C下进行2小时的人工时效。根据ASTM标准，采用拉伸、洛氏硬度、冲击和疲劳试验评估材料的力学性能，并结合显微组织和SEM分析进行研究。结果表明，与未经处理的状态相比，T6处理显著提高了材料的强度和疲劳耐受性。在T6-A2条件（510°C保温2小时+120°C人工时效2小时）下获得了最高的拉伸强度和冲击能，而最长的疲劳寿命则在T6-B1条件（510°C保温1小时+140°C人工时效2小时）下获得。这表明材料在强度和韧性之间实现了良好的平衡，这与细小Mg2Si析出物的形成以及界面结合增强有关。在120°C时效条件下，510°C固溶处理2小时的试样获得了最高硬度。过时效由于析出物粗化而导致延性和抗冲击性能下降。对于耐久型铝–粉煤灰复合材料而言，这些结果表明加工工艺、显微组织与材料性能之间存在明确的关联。
Keywords: Al6061, fly ash, T6 heat treatment, tensile strength, impact energy, fatigue strength
关键词： Al6061；粉煤灰；T6热处理；拉伸强度；冲击能；疲劳强度
How to Cite: Achmad, Z., Ismail, A. E. bin, Seputro, H., & Marliana, E. (2026). The effect of T6 heat treatment on the tensile, impact, and fatigue properties of Al6061-fly ash composites. Teknomekanik, 9(2), 162–176. https://doi.org/10.24036/teknomekanik.v9i2.50672
Component-wise exergy loss analysis under injection timing and EGR variations in a heavy-duty diesel engine
重型柴油机在喷油正时和EGR变化下的部件级火用损失分析
Eihab A. Raouf Mustafa, Department of Mechanical Engineering, College of Engineering, Qassim University, Saudi Arabia
DOI: https://doi.org/10.24036/teknomekanik.v9i2.54472
Abstract
This study investigates the component-wise exergy behavior of a heavy-duty diesel engine under combined variations in injection timing and exhaust gas recirculation (EGR). A calibrated Diesel-RK model was used to simulate steady-state operation over a representative speed-load range. Fuel, brake, exhaust, wall heat, and destruction exergy terms were then evaluated using a consistent post-processing framework. The results showed that increasing EGR from 0 to 0.20 reduced the brake exergy fraction from 33% to 14%. In comparison, the destruction fraction increased from 44% to 73%, indicating that dilution intensified combustion-related irreversibility with a greater influence on irreversibility than on wall heat transfer. Across the investigated speed-load range without EGR, destruction typically remained within about 39–45% of fuel exergy. Advancing injection timing shifted heat release toward top dead center and redistributed wall heat exergy from the liner (40% to 26%) toward the piston and cylinder head, with contributions increased to approximately 37–40% each. At high load, moderate advancement improved thermodynamic efficiency, whereas excessive advancement increased wall thermal loading and reduced further gains. At part load, sensitivity increased because combustion duration appeared to influence thermal response more strongly than peak temperature. A limited trade-off region was identified in which exergy efficiency exceeded about 30%, and destruction dropped below roughly 45%, primarily at advanced timing and high load. However, excessive injection advancement resulted in physically infeasible EGR operation due to insufficient exhaust pressure to sustain recirculation flow, thereby defining a practical operating boundary. Injection timing affected not only efficiency but also whether EGR could function, therefore, optimal calibration must balance combustion phasing, dilution-induced irreversibility, and component-level thermal loading.
摘要
本研究研究了喷油正时与废气再循环（EGR）联合变化条件下重型柴油机的部件级火用特性。采用经过标定的Diesel-RK模型，对具有代表性的转速-负荷范围内的稳态运行工况进行模拟。随后，采用一致的后处理框架对燃料火用、制动火用、排气火用、壁面传热火用和火用毁灭项进行评估。结果表明，当EGR从0增加至0.20时，制动火用率由33%降至14%。相比之下，火用毁灭率由44%增加至73%，表明稀释作用加剧了与燃烧相关的不可逆性，其对不可逆性的影响大于对壁面传热的影响。在所研究的无EGR转速-负荷范围内，火用毁灭通常保持在燃料火用的约39–45%范围内。提前喷油正时使放热过程向上止点方向移动，并使壁面传热火用由气缸套（40%降至26%）重新分配至活塞和气缸盖，两者的贡献率分别提高至约37–40%。在高负荷条件下，适度提前喷油正时可提高热力学效率，而过度提前则会增加壁面热负荷，并使进一步的效率提升受到限制。在部分负荷条件下，系统敏感性增加，这是因为燃烧持续时间似乎比峰值温度对热响应具有更强的影响。研究确定了一个有限的权衡区域，在该区域内火用效率超过约30%，且火用毁灭率低于约45%，该区域主要出现在提前喷油正时和高负荷条件下。然而，过度提前喷油会由于排气压力不足以维持再循环流动而导致物理上不可行的EGR运行状态，从而确定了实际运行边界。喷油正时不仅影响效率，还影响EGR能否正常运行。因此，最佳标定必须在燃烧相位、稀释引起的不可逆性以及部件级热负荷之间实现平衡。
Keywords: combustion irreversibility, diesel engine, exergy analysis, exhaust gas recirculation, injection timing
关键词： 燃烧不可逆性；柴油机；火用分析；废气再循环；喷油正时
How to Cite: Mustafa, E. A. R. (2026). Component-wise exergy loss analysis under injection timing and EGR variations in a heavy-duty diesel engine. Teknomekanik, 9(2), 177–202. https://doi.org/10.24036/teknomekanik.v9i2.54472
CFD-based Taguchi optimization of impeller geometry to improve centrifugal fan efficiency
基于CFD的离心风机叶轮几何参数Taguchi优化以提高风机效率
Delima Yanti Sari, Department of Mechanical Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Bagas Santoso, Department of Mechanical Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Hendri Nurdin, Department of Mechanical Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Hastuti Hastuti, Department of Electrical Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Rifelino Rifelino, Department of Mechanical Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Fitrah Qalbina, Department of Mechanical Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Tsung-Liang Wu, Department of Mechatronics Engineering, National Kaohsiung University of Science and Technology, Taiwan
Dani Harmanto, Department of Aeronautical Engineering, De Montfort University, United Kingdom
DOI: https://doi.org/10.24036/teknomekanik.v9i2.53772
Abstract
Centrifugal fans play a significant role in industrial ventilation systems. Their performance is affected by aerodynamic losses such as flow separation and non-uniform pressure distribution, thereby reducing the overall efficiency. Since design parameters influence the fan efficiency, design parameter optimization becomes one option for addressing this issue. Some optimization methods involve high computational cost and complex procedures. This raises the necessity for a more efficient and systematic optimization procedure. The aim of this study is to propose an integrated approach which involves Computational Fluid Dynamics (CFD) and the Taguchi method to improve the performance of a centrifugal fan. CFD is used to evaluate the performance of different design combinations, while the Taguchi method is used to optimize design parameters. The investigated design parameters are the inlet blade angle (β1), the outlet blade angle (β2), the number of blades (n), and the flow rate (Q). Each of the design factors has three levels, therefore, an L9 orthogonal array was utilized as the design of experiments. Analysis of variance (ANOVA) is used to determine their relative significance. The results show that the optimal combination of design parameters increase the efficiency from 39.79% (the reference) to 63.26%. The CFD simulations for the optimal combination exhibit the improved flow behaviour, which explains the enhanced efficiency. The results show the feasibility of the proposed method for improving the performance of the centrifugal fan.
摘要
离心风机在工业通风系统中发挥着重要作用。其性能受到流动分离和压力分布不均匀等气动损失的影响，从而导致整体效率降低。由于设计参数会影响风机效率，因此优化设计参数成为解决这一问题的一种途径。一些优化方法具有较高的计算成本和复杂的操作流程，因此有必要采用更加高效和系统化的优化方法。本研究旨在提出一种结合计算流体力学（CFD）与Taguchi方法的集成方法，以提高离心风机的性能。采用CFD评估不同设计参数组合下的风机性能，并利用Taguchi方法对设计参数进行优化。研究所考察的设计参数包括进口叶片角（β1）、出口叶片角（β2）、叶片数量（n）和流量（Q）。每个设计因素设置三个水平，因此采用L9正交试验表进行试验设计。通过方差分析（ANOVA）确定各参数的相对显著性。结果表明，优化后的设计参数组合可使风机效率由参考值39.79%提高至63.26%。最优组合的CFD模拟结果显示，流动特性得到改善，这解释了风机效率的提高。研究结果表明，所提出的方法能够有效用于改善离心风机的性能。
Keywords: centrifugal fan, design configurations, HVAC systems, impeller geometry optimization
关键词： 离心风机；设计配置；HVAC系统；叶轮几何参数优化
How to Cite: Sari, D. Y., Santoso, B., Nurdin, H., Hastuti, H., Rifelino, R., Qalbina, F., Wu, T.-L., & Harmanto, D. (2026). CFD-based Taguchi optimization of impeller geometry to improve centrifugal fan efficiency. Teknomekanik, 9(2), 203–217. https://doi.org/10.24036/teknomekanik.v9i2.53772
Flow-rate estimation in PVC and carbon-steel pipes using flow-induced vibrations and data-driven models
基于流致振动与数据驱动模型的PVC和碳钢管道流量估算
Khalid Alnabhani, Department of Mechanical and Industrial Engineering, College of Engineering, University of Technology and Applied Sciences, Sultanate of Oman
Musaab Zarog, Department of Mechanical and Industrial Engineering, College of Engineering, Sultan Qaboos University, Sultanate of Oman
Hadj Bourdoucen, Department of Electrical and Computer Engineering, College of Engineering, Sultan Qaboos University, Sultanate of Oman
DOI: https://doi.org/10.24036/teknomekanik.v9i2.53072
Abstract
Non-intrusive flow measurement methods are increasingly required in pipeline systems to eliminate pressure losses, prevent contamination, and avoid structural modifications. Flow-induced vibration (FIV) offers a promising alternative; however, its applicability to standard industrial carbon-steel pipelines and its integration with data-driven modeling remain limited. This study experimentally investigates FIV-based flow estimation in 1-inch PVC and carbon-steel pipes conveying water under controlled conditions using regression and machine learning models while examining the influence of pipe material and vibration-response characteristics on flow-rate prediction performance. Vibration responses were measured using a tri-axial accelerometer and analyzed to identify flow-sensitive frequency bands. Regression and machine-learning models were developed to relate vibration characteristics to flow rate. The results demonstrate a predominantly monotonic relationship between band-averaged vibration amplitude and flow rate, with material-dependent sensitivity observed between PVC and carbon-steel pipes. Data-driven models improved prediction performance and robustness based on the dynamic behavior of flow-induced vibrations. The findings demonstrate the potential of combining FIV analysis with intelligent modeling as a non-intrusive approach for flow measurement in industrial pipelines. Neural time-series modeling was used for training purposes only. Open-loop training provides a stable and efficient way for the network to learn the underlying dynamic relationship between inputs and outputs. A meaningful assessment of the model's predictive capability requires closed-loop testing, where the network relies on its own previous predictions. This was not conducted in the present study.
摘要
非侵入式流量测量方法在管道系统中的需求日益增加，因为它能够消除压力损失、防止介质污染，并避免对管道结构进行改造。流致振动（Flow-Induced Vibration, FIV）是一种具有应用前景的替代方案。然而，其在标准工业碳钢管道中的适用性以及与数据驱动建模的结合研究仍然有限。本研究通过实验研究了在受控条件下，利用回归模型和机器学习模型对输送水介质的1英寸PVC管和碳钢管进行基于FIV的流量估算，并分析了管道材料及振动响应特性对流量预测性能的影响。采用三轴加速度计测量振动响应，并对数据进行分析，以识别对流量敏感的频率区间。随后建立回归模型和机器学习模型，将振动特征与流量建立关联。结果表明，频带平均振动幅值与流量之间呈现出明显的单调关系，同时PVC管和碳钢管表现出与材料相关的灵敏度差异。基于数据驱动的方法提高了流量预测的性能和鲁棒性，并能够更好地反映流致振动的动态特性。研究结果表明，将FIV分析与智能建模相结合，可作为工业管道非侵入式流量测量的一种有效方法。本研究中的神经网络时间序列模型仅用于训练阶段。开环训练能够使网络稳定且高效地学习输入与输出之间的动态关系，而对模型预测能力进行有效评估则需要采用闭环测试，即网络依赖自身先前的预测结果进行推断。本研究尚未开展闭环测试。
Keywords: frequency-domain analysis, flow-induced vibrations, machine learning, neural network, non-intrusive flow measurement
关键词： 频域分析；流致振动；机器学习；神经网络；非侵入式流量测量
How to Cite: Alnabhani, K., Zarog, M., & Bourdoucen, H. (2026). Flow-rate estimation in PVC and carbon-steel pipes using flow-induced vibrations and data-driven models. Teknomekanik, 9(2), 218–237. https://doi.org/10.24036/teknomekanik.v9i2.53072
Performance evaluation of a standalone PCA-based denoising method for Distributed Acoustic Sensing (DAS) data
基于独立PCA的分布式声学传感（DAS）数据去噪方法性能评估
Monowar Mahmud, Department of Electrical and Electronic Engineering, Universiti Tenaga Nasional, Malaysia
Aiman Ismail, Department of Electrical and Electronic Engineering, Universiti Tenaga Nasional, Malaysia
Fairuz Abdullah, Department of Electrical and Electronic Engineering, Universiti Tenaga Nasional, Malaysia
Hui Jing Lee, Department of Electrical and Electronic Engineering, Universiti Tenaga Nasional, Malaysia
Nur Luqman Saleh, Department of Computer and Communications System Engineering, Faculty of Engineering, Universiti Putra Malaysia, Malaysia
Abdul Hadi Sulaiman, School of Physics, Universiti Sains Malaysia, Malaysia
DOI: https://doi.org/10.24036/teknomekanik.v9i2.44372
Abstract
This paper experimentally evaluates the effectiveness of Principal Component Analysis (PCA) for denoising distributed acoustic sensing (DAS) data. Experiments were conducted by applying different vibration strengths using a piezo-electric transducer (PZT) at various sensing locations along the sensing fiber. Unlike existing hybrid PCA-based DAS denoising approaches, this work explicitly investigates PCA as a standalone denoising framework, addressing the lack of systematic evaluation of its effectiveness and practical applicability. Results show that PCA improves the signal-to-noise ratio (SNR) by at least 4.7 dB across a range of strain levels. The SNR also shows improvements exceeding 5 dB for sensing fiber lengths up to ~5.2 km. For ~10.2 km vibration location, PCA still achieved around 2.45 dB of SNR improvement. The PCA algorithm was then compared with traditional denoising algorithms, i.e., Moving Average, Low-Pass Filtering, and Wavelet Denoising, at a fixed sensing fiber length of 3.2 km and 2 Vpp applied to the PZT. PCA outperformed these approaches in noise reduction while maintaining moderate computational cost. Overall, PCA effectively suppresses background noise while preserving the integrity of the vibration signal. These results indicate that standalone PCA is a practical denoising option for DAS applications that require improved SNR at a moderate processing cost.
摘要
本文通过实验评估主成分分析（Principal Component Analysis, PCA）对分布式声学传感（Distributed Acoustic Sensing, DAS）数据进行去噪的有效性。实验采用压电式换能器（PZT）在传感光纤沿线的不同传感位置施加不同强度的振动。与现有基于混合PCA的DAS去噪方法不同，本研究明确考察了PCA作为独立去噪框架的性能，以解决目前对其有效性和实际适用性缺乏系统评估的问题。结果表明，在不同应变水平范围内，PCA能够使信噪比（SNR）至少提高4.7 dB。对于长度最高约5.2 km的传感光纤，SNR的提升幅度超过5 dB。在约10.2 km的振动位置处，PCA仍可实现约2.45 dB的SNR提升。随后，在固定传感光纤长度为3.2 km且施加于PZT上的电压为2 Vpp的条件下，将PCA算法与传统去噪算法，即移动平均（Moving Average）、低通滤波（Low-Pass Filtering）和小波去噪（Wavelet Denoising）进行了比较。结果表明，PCA在保持适中计算成本的同时，在噪声抑制方面优于上述方法。总体而言，PCA能够有效抑制背景噪声，同时保持振动信号的完整性。这些结果表明，对于需要在适中处理成本下提高SNR的DAS应用，独立PCA是一种具有实际应用价值的去噪方法。
Keywords: denoising algorithm, distributed acoustic sensing, PCA performance, principal component analysis
关键词： 去噪算法；分布式声学传感；PCA性能；主成分分析
How to Cite: Mahmud, M., Ismail, A., Abdullah, F., Lee, H. J., Saleh, N. L., & Sulaiman, A. H. (2026). Performance evaluation of a standalone PCA-based denoising method for Distributed Acoustic Sensing (DAS) data. Teknomekanik, 9(2), 238–255. https://doi.org/10.24036/teknomekanik.v9i2.44372
Design, control, and development of a low-cost single-tilt-rotor Tricopter
低成本单倾转旋翼三旋翼无人机的设计、控制与开发
Fahmizal Fahmizal, Department of Electrical Engineering and Informatics, Vocational College, Universitas Gadjah Mada, Indonesia
Ahmad Jaelani Sidik, Department of Electrical Engineering and Informatics, Vocational College, Universitas Gadjah Mada, Indonesia
Priyova Muhammad Rafief, Department of Electrical Engineering and Informatics, Vocational College, Universitas Gadjah Mada, Indonesia
Hari Maghfiroh, Department of Electrical Engineering, Universitas Sebelas Maret, Indonesia
Mariusz Jabłoński, Department of Electrical Engineering, Lodz University of Technology, Poland
Piotr Borkowski, Department of Electrical Engineering, Lodz University of Technology, Poland
DOI: https://doi.org/10.24036/teknomekanik.v9i2.53172
Abstract
This paper presents the design, implementation, and experimental validation of a low-cost PID-based attitude control system for a single-tilt-rotor tricopter. The proposed platform employs a Y-shaped frame configuration with a servo-driven tail-tilt mechanism and is implemented using a low-cost ATmega328P microcontroller and GY-88A IMU sensor. A PID controller was used for inner-loop attitude stabilization of roll, pitch, and yaw motions due to its low computational complexity and suitability for resource-constrained embedded systems. The PID gains were obtained through manual tuning using a tricopter test-bed rig under disturbance-free conditions and experimentally evaluated under both static and dynamic wind disturbances. Under a static wind disturbance of 7.2 m/s, the roll and pitch mean absolute error (MAE) values reached 0.977° and 4.826°, respectively, while dynamic disturbance testing produced MAE values of 0.823° for roll and 2.094° for pitch. Outdoor flight tests resulted in MAE values of 1.133° for roll and 1.831° for pitch. The experimental results demonstrated that the proposed low-cost tricopter platform can maintain stable attitude control under the evaluated disturbance conditions and outdoor flight scenarios. The study highlights the feasibility of implementing reliable tricopter stabilization using computationally lightweight PID control on inexpensive embedded hardware.
摘要
本文介绍了一种低成本、基于PID的单倾转旋翼三旋翼无人机姿态控制系统的设计、实现与实验验证。所提出的平台采用Y形机架结构，并配备由舵机驱动的尾部倾转机构，系统基于低成本ATmega328P微控制器和GY-88A IMU传感器实现。由于PID控制器具有较低的计算复杂度，并适用于资源受限的嵌入式系统，因此采用PID控制器对滚转、俯仰和偏航运动进行内环姿态稳定控制。PID增益通过在无扰动条件下使用三旋翼测试台架进行手动调试获得，并在静态和动态风扰动条件下进行了实验评估。在7.2 m/s的静态风扰动下，滚转和俯仰的平均绝对误差（MAE）分别达到0.977°和4.826°；而在动态扰动测试中，滚转和俯仰的MAE分别为0.823°和2.094°。室外飞行测试中，滚转和俯仰的MAE分别为1.133°和1.831°。实验结果表明，所提出的低成本三旋翼无人机平台能够在所评估的扰动条件和室外飞行场景下保持稳定的姿态控制。研究结果突出了在低成本嵌入式硬件上采用计算量较小的PID控制实现可靠三旋翼无人机稳定控制的可行性。
Keywords: low-cost UAV development, PID-based attitude control, single-tilt-rotor UAV, tricopter
关键词： 低成本UAV开发；基于PID的姿态控制；单倾转旋翼UAV；三旋翼无人机
How to Cite: Fahmizal, F., Sidik, A. J., Rafief, P. M., Maghfiroh, H., Jabłoński, M., & Borkowski, P. (2026). Design, control, and development of a low-cost single-tilt-rotor Tricopter. Teknomekanik, 9(2), 256–271. https://doi.org/10.24036/teknomekanik.v9i2.53172
Trade-offs in thermal and mechanical properties of cellulose films from bacterial cellulose powder induced by ultrasonication duration
超声处理时间对细菌纤维素粉末制备纤维素薄膜热性能与力学性能权衡的影响
Dieter Rahmadiawan, Department of Mechanical Engineering, National Cheng Kung University, Taiwan
Tio Baskara, Department of Mechanical Engineering, Faculty of Engineering, Universitas Andalas, Indonesia
Hairul Abral, Department of Mechanical Engineering, Faculty of Engineering, Universitas Andalas, Indonesia
Eni Sugiarti, Research Center for Advanced Materials, National Research and Innovation Agency (BRIN), Indonesia
Ahmad Novi Muslimin, Research Center for Advanced Materials, National Research and Innovation Agency (BRIN), Indonesia
Shih-Chen Shi, Department of Mechanical Engineering, National Cheng Kung University, Taiwan
Thiago F. Santos, Postgraduate Program in Chemical Engineering, Federal University of Rio Grande do Norte, Brazil
Imtiaz Ali Laghari, Department of Electrical Engineering, The University of Larkano, Pakistan
DOI: https://doi.org/10.24036/teknomekanik.v9i2.57372
Abstract
Understanding the trade-offs between thermal and mechanical properties is crucial for optimizing the performance of cellulose films from bacterial cellulose powders (BCP). This study leverages ultrasonication as an eco-friendly method to enhance these properties in BCP-based films while investigating the consequences of varying ultrasonication durations. BCP was sonicated at 250 W for 15 and 30 minutes. Results demonstrated that increasing ultrasonication duration significantly improves tensile strength, toughness, and transparency. The 30-minute sonication yielded the most robust and transparent films, with the highest mechanical strength and toughness. Conversely, while a shorter sonication of 15 minutes slightly improved the thermal stability of the films, increasing Tmax from 317°C for non-sonicated films to 351°C, a longer duration of 30 minutes reduced Tmax to 323°C. This illustrates a clear trade-off between enhancing mechanical properties and maintaining thermal stability. The findings provide insights into a simple yet effective approach for producing environmentally friendly, non-wood-based BC films, emphasizing the need to balance both thermal and mechanical enhancements through controlled ultrasonication.
摘要
了解热性能与力学性能之间的权衡关系，对于优化细菌纤维素粉末（BCP）制备纤维素薄膜的性能至关重要。本研究采用超声处理作为一种环保方法，以改善BCP基纤维素薄膜的性能，同时研究不同超声处理时间所产生的影响。BCP分别在250 W功率下进行15分钟和30分钟的超声处理。结果表明，延长超声处理时间能够显著提高薄膜的拉伸强度、韧性和透明度。经过30分钟超声处理后，所得薄膜表现出最高的机械强度和韧性，同时具有最佳的透明度。相比之下，15分钟的较短超声处理时间能够略微提高薄膜的热稳定性，使未经过超声处理薄膜的最大热分解温度（Tmax）由317°C提高至351°C；然而，当超声处理时间延长至30分钟时，Tmax下降至323°C。这表明，提高力学性能与保持热稳定性之间存在明显的权衡关系。本研究为利用受控超声处理制备环保型、非木材来源的细菌纤维素薄膜提供了一种简单而有效的方法，同时强调了在改善热性能与力学性能之间进行平衡的重要性。
Keywords: bacterial cellulose, cellulose nanocrystal, thermal resistance, ultrasonication duration
关键词： 细菌纤维素；纤维素纳米晶体；耐热性；超声处理时间
How to Cite: Rahmadiawan, D., Baskara, T., Abral, H., Sugiarti, E., Muslimin, A. N., Shi, S.-C., Santos, T. F., & Laghari, I. A. (2026). Trade-offs in thermal and mechanical properties of cellulose films from bacterial cellulose powder induced by ultrasonication duration. Teknomekanik, 9(2), 272–284. https://doi.org/10.24036/teknomekanik.v9i2.57372
Experimental investigation of palm oil methyl ester nanofluid as a liquid insulating material
棕榈油甲酯纳米流体作为液体绝缘材料的实验研究
Yusri Jumat, Department of Electrical & Electronic Engineering, Faculty of Engineering, Universiti Malaysia Sarawak, Malaysia
Yanuar Z. Arief, Department of Electrical & Electronic Engineering, Faculty of Engineering, Universiti Malaysia Sarawak, Malaysia
Hendri Masdi, Department of Electrical & Electronic Engineering, Faculty of Engineering, Universitas Negeri Padang, Indonesia
Valentine M. A. A. Jabu, Department of Electrical & Electronic Engineering, Faculty of Engineering, Universiti Malaysia Sarawak, Malaysia
Sharifah M. W. Masra, Department of Electrical & Electronic Engineering, Faculty of Engineering, Universiti Malaysia Sarawak, Malaysia
Nurul I. Hashim, Department of Electrical & Electronic Engineering, Faculty of Engineering, Universiti Malaysia Sarawak, Malaysia
S. K. Sahari, Department of Electrical & Electronic Engineering, Faculty of Engineering, Universiti Malaysia Sarawak, Malaysia
N. Junaidi, Department of Electrical & Electronic Engineering, Faculty of Engineering, Universiti Malaysia Sarawak, Malaysia
S. Rufus, Department of Electrical & Electronic Engineering, Faculty of Engineering, Universiti Malaysia Sarawak, Malaysia
Hamzah Eteruddin, Department of Electrical Engineering, Faculty of Engineering & Computer Science, Jakarta Global University, Indonesia
Sinka Wilyanti, Department of Electrical Engineering, Faculty of Engineering & Computer Science, Jakarta Global University, Indonesia
DOI: https://doi.org/10.24036/teknomekanik.v9i3.52872
Abstract
This study evaluates Palm Oil Methyl Ester (POME) as a potential base fluid for transformer insulation, enhanced with Titanium Dioxide (TiO₂) nanoparticles. The research aims to assess the dielectric strength and physicochemical properties of TiO₂-POME nanofluids at two concentrations (0.05 g/L and 0.10 g/L) and compare them with pure POME. The breakdown voltage (BDV) test was conducted before and after thermal ageing to determine how the nanofluid's dielectric strength changes over time. Results showed that both nanofluid samples had higher BDV values than pure POME, with the 0.05 g/L sample increasing from 19.27 kV to 25.85 kV and the 0.10 g/L sample showing the most significant improvement, with a BDV of 33.17 kV. Ageing caused a slight decrease in BDV, but the values remained higher than those of the base fluid (15.40 kV for aged pure POME), with the 0.05 g/L and 0.10 g/L samples maintaining averages of 20.68 kV and 24.44 kV, respectively, suggesting improved insulation performance. The kinematic viscosity of pure POME was 8.85 cSt, while the 0.05 g/L and 0.10 g/L TiO₂ nanofluids showed values of 9.09 cSt and 9.52 cSt, respectively, with all the samples falling within the acceptable range of 3-12 cSt specified by IEC 60296 for transformer insulating oils. The addition of TiO₂ slightly increased viscosity, more noticeably at 0.10 g/L. FTIR analysis indicated that the chemical structure of the fluid remained stable after ageing and nanoparticle addition.
摘要
本研究评估了棕榈油甲酯（POME）作为变压器绝缘潜在基础液体的应用，并通过添加二氧化钛（TiO₂）纳米颗粒对其进行改性。研究旨在评估两种浓度（0.05 g/L和0.10 g/L）的TiO₂-POME纳米流体的介电强度和理化性质，并将其与纯POME进行比较。通过在热老化前后进行击穿电压（BDV）测试，确定纳米流体介电强度随时间的变化。结果表明，两种纳米流体样品的BDV值均高于纯POME，其中0.05 g/L样品的BDV由19.27 kV提高至25.85 kV，而0.10 g/L样品表现出最显著的改善，其BDV达到33.17 kV。热老化导致BDV略有下降，但其数值仍高于基础液体老化后纯POME的15.40 kV；其中，0.05 g/L和0.10 g/L样品的平均BDV分别保持在20.68 kV和24.44 kV，表明其绝缘性能得到改善。纯POME的运动黏度为8.85 cSt，而0.05 g/L和0.10 g/L TiO₂纳米流体的运动黏度分别为9.09 cSt和9.52 cSt，所有样品均处于IEC 60296规定的变压器绝缘油可接受范围3–12 cSt内。TiO₂的加入使黏度略有增加，在0.10 g/L浓度下表现得更为明显。FTIR分析表明，经过热老化及添加纳米颗粒后，液体的化学结构仍保持稳定。
Keywords: AC breakdown voltage, FTIR spectra, nanofluid, palm oil methyl ester, physicochemical properties
关键词： 交流击穿电压；FTIR光谱；纳米流体；棕榈油甲酯；理化性质
How to Cite: Jumat, Y., Arief, Y. Z., Masdi, H., Jabu, V. M. A. A. ., Masra, S. M. W., Hashim, N. I., Sahari, S. K., Junaidi, N., Rufus, S., Eteruddin, H., & Wilyanti, S. (2026). Experimental investigation of palm oil methyl ester nanofluid as a liquid insulating material. Teknomekanik, 9(3), 285–301. https://doi.org/10.24036/teknomekanik.v9i3.52872
Systematic solvent screening and selection for papaya seeds oil (PSO) extraction
木瓜籽油（PSO）提取的系统溶剂筛选与选择
Misbahudin Alhanif, Doctorate Program of Chemical Engineering, Faculty of Engineering, Universitas Diponegoro, Indonesia
Andri Cahyo Kumoro, Institute of Food and Remedies Biomaterial, Department of Chemical Engineering Faculty of Engineering, Universitas Diponegoro, Indonesia
Dyah Hesti Wardhani, Institute of Food and Remedies Biomaterial, Department of Chemical Engineering Faculty of Engineering, Universitas Diponegoro, Indonesia
DOI: https://doi.org/10.24036/teknomekanik.v9i3.53672
Abstract
Papaya seed oil (PSO) is a promising sustainable edible oil, owing to its high oleic acid content. PSO extraction can be carried out by first determining the appropriate solvent, method, and operating conditions. Solvent selection significantly influences extraction efficiency, energy demand, and operating cost. However, selecting a solvent via quantitative experiments across various solvents is expensive and time-consuming. Therefore, this study proposes a systematic framework to screen 50 solvents using key criteria: Hansen solubility parameters (HSPs), physical properties, and safety, health, and environment (SHE) aspects. Five selected solvents, including ethyl acetate, acetone, n-hexane, ethanol, and water, were combined in binary and ternary mixtures for experimental testing. The main findings showed that PSO extraction using the Soxhlet method for 6 hours with a binary mixture of ethyl acetate–n-hexane (77.20 and 22.80 vol%) produced the highest yield of 19.28 ± 0.21 wt%, followed by a ternary mixture of n-hexane–acetone–ethanol (64.58, 8.13, and 27.28 vol%) with a yield of 19.15 ± 0.22 wt%. Despite its slightly lower yield, the ternary mixture of n-hexane–acetone–ethanol has physical properties that may improve mass transfer and reduce energy demand during extraction and separation. A preliminary assessment based on current market price indicates that the ternary solvent mixture is cheaper (997.5 USD/MT) than the binary solvent of ethyl acetate–n-hexane (1247.3 USD/MT). Therefore, while identifying the ideal solvent for PSO extraction depends on specific factors, this study offers a systematic approach to solvent selection that streamlines screening and reduces the number of solvents requiring experimental testing.
摘要
木瓜籽油（PSO）因其较高的油酸含量而成为一种具有发展前景的可持续食用油。PSO的提取首先需要确定合适的溶剂、提取方法和操作条件。溶剂的选择会显著影响提取效率、能源需求和运行成本。然而，通过针对多种溶剂开展定量实验来选择溶剂，不仅成本高，而且耗时较长。因此，本研究提出了一种系统的溶剂筛选框架，依据Hansen溶解度参数（HSPs）、物理性质以及安全、健康与环境（SHE）等关键指标，对50种溶剂进行筛选。最终选取乙酸乙酯、丙酮、正己烷、乙醇和水五种溶剂，并将其配制成二元和三元混合物进行实验测试。主要研究结果表明，采用Soxhlet方法提取6小时，使用乙酸乙酯–正己烷二元混合溶剂（77.20和22.80 vol%）时，PSO的提取率最高，达到19.28 ± 0.21 wt%；其次为正己烷–丙酮–乙醇三元混合溶剂（64.58、8.13和27.28 vol%），其提取率为19.15 ± 0.22 wt%。尽管三元混合溶剂的提取率略低，但正己烷–丙酮–乙醇三元混合物的物理性质可能有利于改善传质过程，并降低提取和分离过程中的能源需求。基于当前市场价格的初步评估表明，三元混合溶剂的价格为997.5 USD/MT，低于乙酸乙酯–正己烷二元混合溶剂的1247.3 USD/MT。因此，虽然PSO提取的理想溶剂选择取决于具体因素，但本研究提供了一种系统的溶剂选择方法，可简化筛选过程，并减少需要进行实验测试的溶剂数量。
Keywords: extraction, papaya seeds oil, solvent mixture, solvent screening
How to Cite: Alhanif, M., Kumoro, A. C., & Wardhani, D. H. (2026). Systematic solvent screening and selection for papaya seeds oil (PSO) extraction. Teknomekanik, 9(3), 302–329. https://doi.org/10.24036/teknomekanik.v9i3.53672
