Engineering Science and Materials Commons^™

A Systematic Review Of Alkali-Treated Polylactic Acid Biocomposites Relevant To Pineapple Leaf And Water Hyacinth Hybrid Design, Muhammad Rizky Adrianto Subandi, Tri Hartutuk Ningsih, Hanna Zakiyya

Journal of Mechanical Engineering Science and Technology (JMEST)

The increasing demand for sustainable materials has accelerated the development of biodegradable polymer composites. Polylactic acid (PLA)-based natural fiber composites have attracted significant attention due to their renewable characteristics; however, their performance remains limited by weak fiber–matrix compatibility, moisture sensitivity, and inconsistent interfacial behavior. Alkali treatment has been widely applied to modify lignocellulosic fibers by removing non-cellulosic components and improving surface characteristics, although its effectiveness remains dependent on treatment conditions and fiber properties. This systematic review evaluates the influence of alkali treatment on PLA-based natural fiber composites and assesses the available evidence supporting future pineapple leaf fiber (PALF) and water …

Effect Of Cryogenic Soaking Duration On The Crystallographic Structure And Corrosion Resistance Of Astm A36 Steel, Sukri Mubarok, Andoko Andoko, Retno Wulandari

Journal of Mechanical Engineering Science and Technology (JMEST)

This study investigates the influence of cryogenic soaking duration on the crystallographic characteristics and corrosion resistance of ASTM A36 structural steel. Specimens were immersed in liquid nitrogen at −196°C for 0, 12, 36, and 60 hours. Crystallographic analysis was conducted using X-ray diffraction (XRD), while electrochemical corrosion behavior was assessed through Tafel polarization in 3.5% NaCl solution using an Autolab PGstat. Key parameters evaluated included crystallite size, microstrain, dislocation density, corrosion rate, and material degradation. The results showed that soaking up to 36 hours significantly refined the microstructure, as indicated by reduced crystallite size and increased dislocation density and microstrain. …

Thermal Performance Analysis And Heat Transfer Characteristics Of A Solar Powered Paddy Dryer Using A Flat Plate Solar Collector, Peter Sahupala, Daniel Parenden

Journal of Mechanical Engineering Science and Technology (JMEST)

Freshly harvested paddy holds much water (23.00% wet basis in this study) and spoils quickly without prompt drying. Open sun drying depends on the weather and heats the grain unevenly. This study tested an indirect solar paddy dryer with a 0.60 m² flat plate collector, a 10 kg capacity, and natural convection airflow in Merauke, South Papua. Six thermocouples (collector, drying chamber, and chimney), a pyranometer, and a moisture meter recorded data every 15 minutes at drying temperatures of 40°C, 50°C, and 60°C. The data gave useful heat energy, collector thermal efficiency, and drying rate. Useful heat energy ranged from …

The Effects Of Transportation Distribution On Dry Ice Insulated Containers' Thermal Performance, Edmund Tang

Journal of Applied Packaging Research

This study builds upon methodologies established in a 2024 investigation of the combined effects of physical distribution stresses and thermal environments on cold chain packaging performance. Prior results showed that moisture-resistant gel packs generally maintained a vaccine storage range of +2°C to +8°C. However, when exposed to extreme combined stresses, thermal performance degradation of up to 13.5% was observed. The present work applies a similar experimental framework to transportation systems that rely on dry ice as the primary cooling medium, addressing the distinct challenges associated with ultra-cold distribution.

Pharmaceutical products requiring dry ice are highly temperature-sensitive and vulnerable to performance …

Metal Oxide Semiconductor Gas Sensors For Exhaled Breath Cancer Biomarker Detection, Guang-Lan Chen, Hui-Hui Luo, Wen-Wen Peng, Shi-Yu Xu, Yu-Ting Li, Hui-Jie Ke, Si-Hui Zhong, Jia-Ao Wei, Tong Chen, Xiao-Kun Li, You-Lin Zhang, Wei Chen

Journal of Electrochemistry

Early cancer screening can significantly improve therapeutic outcomes, volatile organic compounds (VOCs) and other related gases in exhaled breath, as cancer-specific biomarkers, offer a novel approach for non-invasive diagnosis. Metal oxide semiconductor (MOS)-based gas sensors are pivotal for exhaled breath VOCs detection, featuring compact size, cost-effectiveness, and rapid response. This review summarizes the most recent five-year research advances in cancer biomarker detection, and clarifies the core mechanisms of electrical property changes from sensing material-VOCs interactions and key performance metrics including sensitivity, selectivity, humidity tolerance, response/recovery time, stability, and operating temperature. This review also highlights the optimization strategies of sensing materials …

Electrocatalytic Oxidation Of Ethylene Glycol To Glycolic Acid: From Mechanism And Catalyst Design To Emerging Neutral Electrolyte Systems, Man Zhang, Xue Li, Xin-Yu Peng, Lin Wang, Wen-Wen Chen, Yao-Yue Yang

Journal of Electrochemistry

Polyethylene terephthalate (PET) waste represents both an environmental burden and a loss of carbon resources. Alkaline depolymerization of PET yields terephthalic acid and ethylene glycol (EG). Electrocatalytic oxidation of EG to glycolic acid (GA), the monomer of biodegradable polyglycolic acid (PGA), offers a sustainable route driven by renewable electricity. However, the ethylene glycol oxidation reaction (EGOR) involves competing pathways toward C2 products (GA and oxalic acid) and C1 products (formic acid and CO₂), making selective GA production a central challenge. This review provides a comprehensive overview of recent progress in selective EG-to-GA electrooxidation from catalyst design, mechanistic understanding, …

Regularization-Based Crystallite Size Distribution Analysis Of Pt/C Catalysts From X-Ray Diffraction, Cheng-Long Ma, Wei-Yu Shi, Zhong-Jun Hou

Journal of Electrochemistry

Accurate determination of the platinum crystallite size distribution in carbon-supported platinum (Pt/C) catalysts is critical for evaluating both the initial performance and long-term durability of proton exchange membrane fuel cells (PEMFCs). Conventional characterization approaches—including transmission electron microscopy (TEM), small-angle X-ray scattering (SAXS), and the Scherrer equation—are limited by restricted statistical sampling, sensitivity to support interference, or the inability to resolve the full breadth of the size distribution. In this work, we present a regularization-based inversion framework that extracts the volume-weighted crystallite size distribution directly from X-ray diffraction (XRD) line profiles, without requiring any a priori assumption regarding the functional form …

Propuesta Metodológica Para La Evaluación De La Pobreza Energética En Chiapas, México, Mario Alejandro Sánchez Trujillo, Pascual López De Paz, Marcelino García Benítez, Amina El Mekaoui, Bassam Alí, Jesús Francisco Escalante Euán

Journal of Maya Heritage

Resumen. El acceso inequitativo e insuficiente a servicios energéticos de calidad constituye uno de los principales obstáculos para el desarrollo socioeconómico y el bienestar humano en México, siendo el estado de Chiapas una de las entidades con mayor vulnerabilidad socioambiental. Este trabajo presenta una propuesta metodológica cuantitativa y geoespacial para evaluar la pobreza energética de las siete subprovincias fisiográficas de Chiapas. La metodología combina datos de censos de población y vivienda 2020 (INEGI), la estandarización Min-Max, el análisis de correlación de Pearson y el análisis de componentes principales (PCA) para la construcción de un índice de pobreza energética (IPE) multidimensional. …

Investigation Of The Production Technology Of Environmentally Safe Urethane Oligomers Based On Local Raw Materials, Bakhtiyor Kudratovich Shaykulov, Dilafruza Ruziboevna Akbarova Gulboeva, Fayzulla Nurmuminovich Nurqulov

Technical science and innovation

This paper investigates the step-by-step poly condensation pathway for synthesizing environmentally friendly, non-isocyanate urethane oligomers derived from local and safe raw materials: urea and ethylene glycol. The influence of thermodynamic parameters on the target product yield was systematically evaluated to determine the optimum technological matrix. Specifically, a 1:2 reactant mass ratio, a stable stationary temperature of 150-155 °C, and a reaction duration of 2 hours under an inert nitrogen atmosphere resulted in a sustainable and reproducible yield of 72%. Thermal degradation and competitive side-product condensations were activated above 160 °C, leading to a sharp drop in overall chemical efficiency. The …

Integrating Gis With Interim Payment Valuation In Road Construction Projects: A Conceptual Framework, Abdulrahman I. Iro, Juma M. Matindana, Julian Ijumulana

Tanzania Journal of Engineering and Technology (TJET)

Abstract

Interim Payment Valuation is a critical process in road construction contract administration, yet conventional valuation practices remain heavily dependent on manual measurements, fragmented documentation, spreadsheets, and professional judgement. These limitations can affect measurement accuracy, transparency, traceability, and the timeliness of payment certification. Although Geographic Information Systems have increasingly been applied to construction planning, quantity measurement, progress monitoring, infrastructure management, and decision support, their integration with contractual and financial processes for interim payment valuation remains insufficiently explored. This study therefore develops a conceptual framework for integrating GIS with Interim Payment Valuation in road construction projects. A PRISMA-guided structured literature review …

Voltage-Related Power Quality Issues And Impacts On Distribution Networks With Sensitive Loads - A Review, Godwin Elinazi Mnkeni, Jackson Justo, Aviti Thadei Mushi, Bakari M. M. Mwinyiwiwa

Tanzania Journal of Engineering and Technology (TJET)

Voltage disturbances are the most important power quality (PQ) complications that customers and power utilities face in this smart era. The growing adoption of sophisticated electronic equipment and integration of renewable energy sources (RES) into power grids has increased the susceptibility of power distribution networks (PDNs) to voltage sags, swells, interruptions, flicker, and voltage imbalance. These disturbances, mainly caused by upstream faults, switching operations, and RES integration, compromise voltage PQ and system reliability. Consequently, they accelerate equipment degradation, increase electronic waste (e-waste), raise reactive power demand and maintenance costs, increase power losses, and impose substantial economic losses on customers and …

Experimental Study On The Behavior Of High-Strength Reinforced Concrete Beams With A Longitudinal Void, With And Without Micro Steel Fibers, At Different Shear Spans, Farah M. Hussein, Saif Altai, Shatha Alasadi, Ayoob A. Ibrahim, Arshad Nadhom Shubber

Journal of Sustainable Construction Materials and Technologies

This study examines the impact of creating a longitudinal void in high-strength reinforced concrete (RC) beams to decrease concrete volume. Testing involved three groups: solid beams (SB), beams with a 75 mm void (VB), and beams with a void incorporating 1.2% micro-steel fibers (VBSF), across various shear spans (a/d) of 1.8, 2.7, and 3.6. Results indicated that increased a/d led to a 54.2% reduction in peak loads and a 119.2% increase in deflection for solid beams. The void negatively affected load-bearing at a/d = 1.8 with a 25% peak load reduction and brittle failure. At a/d = 2.7, effects were …

Dense Platinum Nanoparticles Confined In Mn-N-C Nanocages For Robust Heavy-Duty Pemfcs, Lei Zhao, Zhen-Min Cao, Jia-Yu Zuo, Ming-Liang Yang, Hong-Yan Qiao, Jun-Song Chen, Rui Wu

Journal of Electrochemistry

High-loading Pt cathodes are essential for heavy-duty proton exchange membrane fuel cells but suffer from a critical tradeoff between ionomer sulfonate poisoning and nanoparticle instability. Herein, we report a spatial confinement strategy to encapsulate dense Pt nanoparticles (~51.8 wt%) within Mn/N-co-doped mesoporous carbon nanocages (denoted as Pt-MnNC). This architecture excludes bulky ionomers to create an ionomer-shielded environment against sulfonate poisoning, while Mn-N_x-mediated strong metal-support interactions anchor the Pt nanoparticles to prevent agglomeration and further boost durability. In the 5 × 5 cm² membrane electrode assembly tests, the Pt-MnNC catalyst delivers an exceptional power density of 1.26 W·cm …

Efficient Acidic H2O2 Electrosynthesis Over Co Atoms Anchored On Nitrogen-Doped Hierarchical Porous Carbon, Xiao Huang, Zi-Hao Zhan, Hao-Xu Niu, Guan-Yu Luo, Jin-Tao Huang, Bo-Xuan Jin, De-Li Wang

Journal of Electrochemistry

The two-electron oxygen reduction reaction (2e⁻ ORR) presents a promising route for the on-site production of hydrogen peroxide (H₂O₂), offering a green alternative to energy-consuming anthraquinone process. However, the high selectivity toward the competing 4e⁻ ORR over the desired 2e⁻ pathway leads to low Faradaic efficiency for H₂O₂, posing a critical challenge in catalyst design. In this work, a nitrogen-doped hollow hierarchical porous carbon with anchored Co atoms (CoN/HPC) was constructed for high-performance H₂O₂ production. The as-prepared Co-N/HPC catalyst showed excellent 2e⁻ ORR performance, achieving …

Engineering Small-Sized Cations With Strong Solvation For High-Voltage Supercapacitors, Tong Huo, Pan Liu, Hao Chen, Peng Zhang, Zhen-Lei Chen, Guo-Fu Sun, Zhi-Qiang Shi, Jing Wang

Journal of Electrochemistry

Supercapacitors (SCs) have attracted much attention in the field of energy storage due to their high power density and long cycle life. However, their relatively low energy density limits their application in a wider range of fields. Methods to increase energy density include enhancing specific capacitance and extending operating voltage window. Herein, we report a novel electrolyte salt, tetramethylammonium bis(fluorosulfonyl)imide (TMA-FSI), the resulting electrolyte formed with propylene carbonate (PC), designated as TMF, exhibited a wide electrochemical stability window (ESW) of 5.09 V. On the one hand, we found that the small size of TMA⁺ enables it to enter the …

Physical Modeling To Represent Molten-Slag Entrapment Behavior Into Molten-Steel Under Simultaneous Similitude Condition Of Multiple Dimensionless Numbers, Yuichi Tsukaguchi, Sho Nakano

Progress in Scale Modeling, an International Journal

Physical model construction and experiment are essential for scientific investigations of flow phenomena such as high temperature two phase flow of molten metal and inert gas. It has been a common method to construct a physical model with a convenient scale then proceed experiments under similitude condition of one or two dimensionless number(s) of dominant forces to represent. It is an ideal experimental method to satisfy the simultaneous similitude condition of multiple dimensionless numbers concerned with the objective flow phenomena but has been considered difficult or impossible to realize for many years. Contrarily, the concept of the simultaneous similitude of …

Structure Property And Wear Correlations In Al–Ni Intermetallic Coatings Produced By Atmospheric Plasma Spraying, Eman Zayed

Mechanical Engineering

No abstract provided.

Aerodynamic Effects Optimisation Of Water-Powered Funicular Car Body Exposed To Headwind And Crosswind, Theodorus Agung Wicaksono, Bagus Wahyudi, Syamsul Hadi, Wirawan Wirawan, Hangga Wicaksono

Journal of Mechanical Engineering Science and Technology (JMEST)

Water-powered funicular railways are an environmentally friendly mode of transport whose efficiency heavily depends on the principle of gravity. However, their operation is vulnerable to natural wind disturbances that can hinder speed or cause a risk of overturning on steep, curved tracks. This study aims to analyse the influence of funicular car model design on the rolling moment exerted on the rails as the car turns to enter a track branch. The research methodology involves aerodynamic simulations using SolidWorks flow simulation, comparing three body models: WAHYUDI, FUNAERO, and AEROFUN. Simulations were conducted with variations in turn angles (10° to 30°) …

Parametric Study On The Plastic Hinge Length Of Precast Concrete Columns With Grouted Sleeve Connections, Rizky Tri Amalia, Harun Alrasyid

Journal of Sustainable Construction Materials and Technologies

The use of precast concrete structures with grouted sleeve (GS) connections has gained significant traction in the acceleration of bridge construction. The plastic hinge length (Lp) is a critical parameter for assessing the seismic performance and deformation capacity of such structural members. The previous study has proposed empirical equations for Lp in monolithic columns; however, a comprehensive understanding of the influential parameters on Lp in precast concrete columns with GS connections remains limited. This study presents a detailed parametric investigation to evaluate the effects of key design parameters on the plastic hinge length of a precast concrete columns with GS …

Activation-Induced Surface Reconstruction Enables Enhanced Pseudocapacitive Charge Storage And Industrial-Current Hydrogen Evolution In Tetra-Metallic Sulfide Nanoflowers, Menna Hasan

Nanotechnology Research Centre

Developing efficient, durable, and earth-abundant electrocatalysts for alkaline water electrolysis is critical for sustainable hydrogen production. Transition-metal sulfides have emerged as promising hydrogen evolution reaction (HER) catalysts; however, their catalytic behavior is often governed by dynamic structural transformations occurring under operating conditions. Herein, we report the synthesis of tetra-metallic Ni-Co-Fe-Mn sulfide nanoflowers directly grown on Ni foam via a one-step hydrothermal approach. The as-prepared catalysts underwent significant electrochemical activation, leading to surface reconstruction and enhanced catalytic activity. The optimized catalyst exhibited a remarkable reduction in overpotential from 300 mV to 121 mV at 100 mA cm⁻², further decreasing to 100 …