The articles published in Teknomekanik Volume 9, Issue 3 (2026) present recent developments in mechanical engineering, materials science, manufacturing technologies, energy systems, tribology, and sustainable engineering applications. This issue brings together 7 scholarly articles authored by researchers from 14 institutions across 4 countries, including Indonesia, Malaysia, Vietnam, and the United Kingdom. The contributions reflect the journal's commitment to promoting scientific collaboration and disseminating research addressing contemporary challenges in engineering and technology.
The contributing institutions include Universitas Negeri Padang, Universitas Diponegoro, Universitas Riau, Universitas Andalas, Universitas Syiah Kuala, Universitas Sumatera Utara, Universitas Negeri Medan, and Jakarta Global University (Indonesia); Universiti Malaysia Sarawak, Universiti Tun Hussein Onn Malaysia, and Universiti Teknologi Malaysia (Malaysia); Vinh Long University of Technology Education and the University of Transport and Communications (Vietnam); and De Montfort University (United Kingdom). These institutional contributions demonstrate collaborative research activities across Southeast Asia and international academic partnerships.
The published papers address a diverse range of engineering topics, including the dielectric and physicochemical properties of palm oil methyl ester nanofluids for liquid transformer insulation, systematic solvent screening for papaya seed oil extraction, enhancement of low-carbon steel hardness through pack carburizing using shellfish shell powder as a natural calcium carbonate activator, and the effects of loading angle and build direction on the tensile behavior of wire arc additive manufactured (WAAM) steel. Other contributions investigate the tribological performance of palm oil-based biolubricants incorporating bacterial cellulose, combustion and emission characteristics of methanol-enriched plastic waste pyrolysis oil in stationary Otto engines, and welding techniques for thermoplastic components produced through fused filament fabrication (FFF). Collectively, these studies highlight the application of experimental investigations, material characterization, process optimization, additive manufacturing, and sustainable resource utilization in addressing current engineering challenges.
In line with the journal's focus and scope, this issue contributes to advancing knowledge in materials engineering, manufacturing and additive manufacturing technologies, mechanical properties and performance, energy conversion systems, tribology, and sustainable engineering. The findings provide valuable scientific insights and practical perspectives for researchers, engineers, academics, and industry practitioners seeking innovative solutions to improve material performance, manufacturing processes, energy efficiency, and environmental sustainability.