Vol. 57 No. 2 (2025)

Lactic acid is a metabolite produced during glucose glycolysis, typically generated industrially through the fermentation of glucose using microorganisms. However, the high production cost of this fermentation process makes lactic acid relatively expensive, rendering biodegradable plastics made from polylactic acid less competitive. This research focuses on the initial stages of glucose glycolysis process, in which glucose is split into dihydroxyacetone and glyceraldehyde, both of which are isomers of lactic acid. Biomimetic metal-organic catalysts composed of Mg-Zn tripolyphosphate,…

Buildings account for approximately 40% of the total global energy consumption. Therefore, accurate prediction of building energy consumption is necessary to optimize resource allocation and promote sustainable energy usage. A key challenge in developing building energy consumption models is their adaptability to abrupt changes in consumption patterns owing to extraordinary events, such as the COVID-19 pandemic. Therefore, a two-layer ensemble-learning (EL) model incorporating sliding windows as input features is proposed. The model is a two-layer stacking EL consisting of two base learning…

Working in hot and humid environments poses significant challenges to thermoregulation and potentially affects performance and health. Strategies for mitigating heat stress are critical for workers exposed to high thermal loads. This study investigated practical cooling strategies, that is, phase-change vest (PCV) cooling and crushed ice (ICE) ingestion, before a physical activity in a hot and humid environment to alleviate heat strain. Two experiments were conducted to evaluate the efficacy of the cooling methods: the first experiment involved participants wearing a PCV for precooling, and…

The demand for nanomaterials is rapidly increasing in most applications, such as energy storage devices. Many nanomaterial synthesis methods are energy-consuming methods requiring high temperatures, prolonged reaction time, complicated steps, or expensive equipment. Herein, nanostructures of cobalt hydroxide chloride, Co2(OH)3Cl, have been directly deposited on carbon cloth microfibers by a fast and simple step of chemical bath deposition. Co2(OH)3Cl nanoparticles appear in only 10 minutes of the deposition time, then the nanoflakes are grown in 60 minutes, as imaged by scanning electron…

The consolidation analysis becomes complicated when conducted on varying layers of soil. To simplify and solve these problems, designers often employ Finite Element Method (FEM) modeling, a widely used technique for analyzing geotechnical issues. However, many limitations associated with this method can lead to model results that do not accurately reflect actual conditions. Consequently, the consolidation settlement analysis during design may differ from actual conditions in the field. This study examines the influence of consolidation parameters and explores how to analyze consolidation…

This review comprehensively explores the application of Forward Osmosis technology in the food processing industry, focusing on its role in concentration processes. Amidst growing concerns over water scarcity, energy consumption, and environmental impact, Forward Osmosis emerges as a sustainable alternative to traditional methods, offering lower energy requirements and reduced environmental footprint. The paper delves into the theoretical foundations of Forward Osmosis, examining the osmotic process and the dynamics of semi-permeable membranes. It further investigates the technological…

Umbilical or umbilical cable supplies are required for an apparatus, such as a space vehicle, or for a person, a diver, or an astronaut. For launch vehicles, umbilical cables provide essential elements like electrical power, communication, and pressurized gases before liftoff. Ensuring the retraction of these cables is crucial for preventing potential damage during the launch process. This paper addresses a novel mechanism for umbilical retraction in the launch vehicle loading process. This mechanism is based only on the principles that borrow the vehicle’s launch motion to generate a…

The study aims to investigate the effect of numerical analysis on a bitubular circular tube subjected to dynamic loading. To compare its performance, a circular monotube specimen with a perimeter of 300 mm, a thickness of 2 mm, and a length of 350 mm was used as a reference. The bitubular circular tubes consist of two tubes, an inner and an outer. The outer tube's perimeter was initially set at 350mm with a wall thickness of 1 mm, while the inner tube had a perimeter of 250 mm and a thickness of 1 mm. The outer perimeter was gradually decreased by 10 mm, while the inner tube's perimeter was…

Hybrid machining processes (HMP) have been developed to double the benefits of advanced or conventional machining processes by combining them. The challenges that occur in machining of intricate shapes and features, micromachining, and machining of very hard and soft materials can be overcome by HMPs. Assistance from external sources like vibrations, abrasives, and magnetic fields can facilitate material removal and enhance machining efficiency. This paper analyses some important recent research and innovations carried out in the domain of vibration-assisted HMPs and presents them to enrich…

Correction to: Journal of Engineering and Technological Sciences https://doi.org/10.5614/j.eng.technol.sci.2024.56.3.1 The article titled "Investigation of Liquefaction in Balaroa, Petobo, and Jonooge (Central Sulawesi, Indonesia) Caused by the 2018 Palu Earthquake Sequence", written by Rahmat Triyono, Sri Widiyantoro, Zulfakriza, Pepen Supendi, Aditya Setyo Rahman, Mohamad Taufik Gunawan, Nur Hidayati Oktavia, Fajri Syukur Rahmatullah,Fildzah Zaniati Fadhilah, Nur Fani Habibah, Oriza Sativa, Dadang Permana, Robby Wallansha, Ardian Yudhi Octantyo, Yoga Dharma Persada, Bayu Pranata, and…