Vol. 21 No. 1 (2026): April

Praise be to Almighty God for the publication of Jurnal Teknik Mesin Indonesia (JTMI), Volume 21, Number 1, April 2026. This edition reaffirms JTMI’s commitment to providing a high-quality, credible, and relevant scientific publication platform aligned with technological advancements and industrial needs. In this issue, JTMI presents ten scholarly articles covering a broad range of mechanical engineering fields, including sustainable energy, manufacturing, engineering materials, design engineering, as well as mechanical systems and automation. This diversity of topics reflects the ongoing development of mechanical engineering research in Indonesia towards an interdisciplinary, applied, and solution-oriented direction.

The first article examines a life cycle assessment analysis of biobriquette production derived from corn cobs using tapioca as a binder. This study highlights the importance of sustainability approaches in the development of alternative energy. The subsequent article investigates the effect of compression ratio variations in internal combustion engines, contributing to improvements in energy efficiency within the transportation sector. Another study evaluates a solar-powered double-nozzle Venturi aeration system for water quality management in tilapia aquaculture, demonstrating the integration of renewable energy technologies within the fisheries sector. In the field of design engineering, one article presents product design modelling using the finite element method, illustrating the application of numerical simulation in product development.

Within the materials domain, a study analyses the effect of black oxide coating duration on the corrosion resistance and mechanical properties of AISI 4340 steel, providing insights into enhancing engineering material performance. In manufacturing, another study develops a cold forging process for horseshoe nails, indicating efforts to improve the efficiency of conventional production processes. In the context of modern manufacturing, one article applies a condition-based maintenance approach using multisensor data to a wire-cut machine, underscoring the importance of intelligent monitoring systems in industry. Furthermore, additional studies present the development of a livestock feed pellet machine and a pneumatic prototype for material thickness measurement, both reflecting an applied orientation in addressing industrial needs. Another article investigates the effect of piston crown and ring dimensions on motorcycle engine performance, contributing to the advancement of more efficient and reliable automotive technologies.

Overall, the articles in this issue not only demonstrate academic achievement but also reflect efforts to bridge the gap between research and industrial application. Accordingly, the direction of research development is increasingly oriented towards implementation and technological downstreaming. All manuscripts included in this issue have undergone a rigorous peer review process, ensuring their scientific quality, originality, and relevance. In this regard, sincere appreciation is extended to the authors for their valuable contributions, as well as to the reviewers for their dedication and professionalism in the evaluation process.

This edition supports the Sustainable Development Goals (SDGs), particularly in the areas of industry, innovation, and infrastructure (SDG 9), quality education (SDG 4), and sustainable production systems. JTMI remains committed to promoting publications that are not only academically but also impactful for society and industry. Moving forward, JTMI seeks to strengthen its position as an internationally competitive journal through continuous improvement in publication quality, enhancement of global collaboration, and a focus on strategic research areas.

Finally, academics, researchers, and practitioners are cordially invited to contribute to JTMI. Constructive feedback and suggestions are highly appreciated in order to further improve the quality of future editions.