Vol. 58 No. 1 (2026)

Studying the basement depth and fault structures is crucial for understanding basin geometry and fluid migration pathways. This study aims to understand basin geometry using gravity data in the Banten area, Indonesia, as a region with possible hydrocarbon prospects. Anomaly gradients derived from the Bouguer anomaly were conducted for fault analysis. Meanwhile, basement depth estimation was performed using Euler deconvolution, with a Structural Index (SI) of 0 and window sizes of 7 km × 7 km and 10 km × 10 km. Additionally, 3D inversion modelling with Grablox 1.6 was applied to model the…

High-temperature melting and rolling is the key process of laminated steel production. The dynamic fluctuation of the rolling force during the film covering process causes an alternating effect of positive and negative pressures in the film covering area. The roll vibration causes the film to vibrate up and down, leading to the generation and intensification of bubbles, which seriously affects the product quality. In this study, considering the nonlinear stiffness characteristics of a polyethylene terephthalate (PET) film under unidirectional compression in the roll gap, a melting and rolling…

Rail transportations are among the most environmentally friendly modes of transportation due to their low per capita emissions and carbon footprint. This study aims to analyze the total CO2 emissions and per capita emissions of long-distance and local rail transports operating on the island of Java in 2023. Emission calculations were conducted using the IPCC methodology and Sebos’s approach, incorporating factors such as locomotive types, which predominantly use B30 biodiesel and electricity as energy sources. The results are presented in the form of spatial maps for a comprehensive…

To study the large deformation of surrounding rock during the passage of a soft rock tunnel through a fractured zone, a numerical simulation analysis was conducted on a specific tunnel section. The investigation focused on the extrusion deformation at the face, settlement deformation of the arch roof, and stress in the surrounding rock, considering the two support types used in the New Austrian Tunneling Method. The results show that the use of anchor bolts can reduce the pre-convergence deformation by 58.1% and its proportion by 23.5%, significantly increasing the minimum principal stress at…

This study investigated flexural performance of Bangkirai timber beams jointed with glued-in threaded steel rods using epoxy-resin adhesive through experimental test and numerical analysis. Six beam specimens were tested under four-point bending with varying rod diameters, anchorage lengths, and beam widths: GIR B.65.16.17 (65 mm width, 16 mm rod, 170 mm anchorage), GIR B.65.12.25 (65 mm width, 12 mm rod, 250 mm anchorage), and GIR B.110.12.25 (110 mm width, 12 mm rod, 250 mm anchorage). The results showed that anchorage length significantly influenced moment capacity and stiffness of the…

The objective of this study was to evaluate the effects of single-stage thermochemical pretreatment using sodium hydroxide (NaOH) and a double-stage pretreatment combining NaOH and hydrochloric acid (HCl) on the production of reducing sugars and total phenolic compounds (TPC). The influence of pretreatment duration (30–120 minutes) and solvent concentration (NaOH: 0.2–1 N; HCl: 0.05–0.4 N) at 100 °C was systematically investigated. The results showed that the double-stage pretreatment led to a higher yield of reducing sugars while maintaining relatively low TPC levels. Analysis of variance…

Electric vehicles are equipped with electric motors that convert electrical energy into mechanical energy to propel the vehicle. The motor experiences an increase in temperature during operation due to various losses that cause the motor temperature to rise. The performance of the electric motor will be reduced or even damaged if the heat continues to increase and the temperature exceeds 60°C. Therefore, there is a need for a cooling system that can maintain the electric motor

The construction industry

This study investigates the active tectonics of Sulawesi, Indonesia, a seismically active region at the convergence of the Pacific, Australian, and Eurasian plates. We analyze the geological influence on faulting styles and kinematics across the island by integrating geological, geodetic, and geophysical data. Our analysis, which includes geomorphic interpretations, reevaluation of GPS velocities, and earthquake catalogs, reveals diverse deformation regimes in Sulawesi. The North Arm exhibits thrust faulting associated with the subduction zone and normal faulting due to extensional…

This study investigated the effects of partial cement replacement with Fly Ash (FA) and Ground Granulated Blast-furnace Slag (GGBS), as well as the addition of Polyvinyl Alcohol (PVA), on the mechanical and hardness properties of mortars. Mortar mixes were prepared with 15-30% FA (F-series), 15-30% GGBS (G-series), and varying PVA additions (P-series), and compared against a reference mix (Ref). Compressive, tensile, and flexural strengths at 28 days, along with Shore D hardness, were evaluated. Results indicated that both FA and GGBS improved 28-day compressive strength over the reference…