Journal of Engineering and Technological Sciences

Influence of Heat and Mechanical Treatments on the Mechanical and Structural Characteristics of Molded Manganese Steels

2025-11-13T08:57:40+07:00

This paper presents a study to improve the performance of Fe-Mn-C cast steels containing 1.7% and 2.7% Cr by weight, using two treatment methods (thermal and mechanical) applied separately to two different steel grades. This approach enables an extended service life for components such as crusher liners, mill hammers, and level crossings, without requiring complete recasting. The experimental techniques used for characterization included spark optical emission spectroscopy, optical microscopy, scanning electron microscopy, as well as micro- and macro-hardness testing. Steel 1, with a composition of 15.51% Mn, 2.68% Cr, and 1.29% C, was heat-treated at 1070 °C and quenched in water, using different holding times and thicknesses. It was found that increasing the holding time from 30 to 50 minutes and reducing the thickness from 150 to 100 millimeters led to a complete and homogeneous dissolution of carbides. As a result, Steel 1 exhibited increased ductility. Steel 2 contains 13.45% Mn, 1.72% Cr, and 1.21% C. It underwent manual mechanical treatment, which resulted in surface hardening due to the transformation of austenite into martensite.

Polyoxometalates as Catalysts for Biomass Conversion: Properties, Applications, and Regenerability

2025-10-17T12:46:46+07:00

Polyoxometalates (POMs) have emerged as exceptionally versatile catalysts for green chemical reactions, demonstrating significant potential in the sustainable valorization of biomass. Their tunable Brønsted/Lewis acidity and redox properties enable a broad range of chemical transformations, offering remarkable flexibility in process design. This mini review provides a summary of recent advances in the thermocatalytic conversion of biomass using POMs, addressing their utilization as both homogeneous and heterogeneous catalysts. Key reaction pathways, including solvolysis, oxidation, esterification, and condensation, are highlighted as fundamental processes in biomass valorization. A central focus is placed on the crucial challenge of catalyst regenerability and stability, examining strategies to ensure the long-term viability and economic feasibility of these systems while facing the apparent low-temperature stability challenge of POMs. Finally, this review synthesizes current regeneration methods and presents a forward-looking perspective on the future challenges and opportunities in the field of biomass conversion catalyzed by polyoxometalates.

Design and Development of a Water Flow Monitoring Device using Mitsubishi FX3U-14MT PLC

2025-11-13T09:30:26+07:00

Efficient water management is essential for ensuring sustainability and reducing operational costs, especially in small to medium-scale buildings such as schools, health clinics, and office facilities. This paper presents the design and implementation of a cost-effective automated water flow monitoring system, integrating a Mitsubishi FX3U-14MT PLC with an Arduino module to facilitate real-time flow measurement and precise control of solenoid valves. The PLC is programmed using ladder logic, while the Arduino is responsible for processing sensor data, thereby enhancing measurement accuracy and contributing to overall system flexibility. In contrast to conventional industrial automation solutions, this system is specifically designed for small-scale applications, offering an effective balance of affordability, simplicity, and reliability. Experimental testing demonstrates that the system achieves high measurement accuracy, operational stability over extended use, and optimized energy efficiency, ensuring long-term reliability in water flow management. Additionally, the system’s modular design enables straightforward adaptation to various facility sizes and plumbing configurations. These findings validate the proposed system as an accessible yet effective automation solution, particularly suitable for environments where implementing large-scale industrial control systems may be impractical. Future research could focus on incorporating adaptive control algorithms and enhancing sensor integration to further improve system performance and flexibility.

Optimizing Evaporator Design in ORC Systems for Waste-to-Energy Conversion Using FAST Diagram and Value Engineering

2025-09-25T10:24:51+07:00

The global waste crisis necessitates innovative solutions for sustainable energy conversion. This study presents a comprehensive optimization framework for evaporator design in Organic Rankine Cycle (ORC) systems utilized in waste-to-energy conversion. This research integrates the Function Analysis System Technique (FAST) diagram with Value Engineering (VE) principles to assess the logical hierarchy and cost analysis components of system effectiveness. Evaluation of the 887 kW shell-and-tube evaporator showed tubes, baffles, and shells account for 90% of production costs and are the most thermally efficient components. Further strategic redesign under VE principles resulted in 23% cost reduction with 15% efficiency improvements, demonstrating resource expenditure without performance compromise. The proposed approach offers a foundational methodology for advancing enduring ORC system design while harnessing high waste-to-value electrical energy conversion at low expenses, fostering the circular economy.

Enhanced Finite Element Numerical Analysis of Rigid Inclusion Lateral Resistance for Embankment on Slightly Overconsolidated Soft Clay

2025-10-20T14:11:31+07:00

Soft clay soils represent a significant challenge for embankment construction due to high compressibility, low shear strength, low bearing capacity, and excessive settlement potential. This study presents an enhanced finite-element model to evaluate the performance of Mortar Column Inclusion (Inklusi Kolom Mortar, or IKM) as a rigid inclusion supporting embankments over slightly overconsolidated soft clays, as implemented in the Serang-Panimbang Toll Road Project (STA 75+600 to STA 75+800). The propose approach integrates depth-dependent multilinear lateral resistance with structural “dummy” plate elements to capture soil arching within the Load Transfer Platform (LTP) and lateral column-soil interaction—an approach not previously applied in rigid inclusions modeling for soft clays. Studies on numerical modeling of IKM systems in slightly overconsolidated soft clays remain limited. Finite element analyses are conducted using PLAXIS 2D and 3D with axisymmetric, unit-cell, and plane strain approaches. The results show that the "dummy" plate simulates soil arching in the LTP and improves the representation of negative skin friction, neutral-plane transition, and axial load distribution. Depth-dependent lateral resistance enhances predictions of column bending moments and horizontal deformation within varying soil layers. Field validation indicates good agreement, with inclinometer displacement predicted at 40.79 mm (difference < 10%). Predicted vertical settlements of 20.71 cm (centerline) and 19.38 (edge) are also consistent with settlement plate readings of 15.80 and 11.00 cm, respectively. These findings confirm that the enhanced model provides a comprehensive evaluation of stress distribution, pile deformation, and global stability for ground improvement design in soft clays