Motion sickness (MS) is a common issue for vehicle passengers, characterized by symptoms such as nausea, dizziness, and discomfort due to sensory conflicts between the visual and vestibular systems. This study aims to identify and quantify the modulating factors contributing to MS in vehicles within the Malaysian context. A systematic questionnaire was conducted, incorporating subjective feedback from 634 participants. The results highlight key factors like seating position, visual activities, and environmental conditions that influence MS susceptibility showing the most prominent factors are from Visual Activity with a mean of 3.44 among the others contributing most susceptibility from the activities of Reading (83.2%) and Writing (79.2%). Older people and females seemed to report greater susceptibility to motion sickness. This vulnerability is shown to increase with age as those 45+ years and above show the highest susceptibility, reporting a 69% rate on curvy roads and 66% during reading, in contrast with those between 18-29 who report a 52% and 50% susceptibility rate. Females again reported consistently higher rates than males, with the difference being larger in situations involving rear-facing seating or tasks requiring significant visual focus, such as reading (female 63% vs. male 46%) and driving on curvy roads (female 68% vs. male 50%). These factors of rear-facing seating and tasks involving intense visual focus, like reading or watching videos, were the strongest modulators identified, with a strong aggravating influence on symptoms across all groups. The findings provide crucial baselines for engineering future vehicle layouts, optimizing cabin climate systems, and designing targeted mitigation systems required to support human comfort and accelerate Automated Vehicle (AV) adoption in developing transport infrastructures.
The performance of a proton exchange membrane fuel cell (PEMFC) is strongly influenced by its operating conditions. In this study, a one-dimensional (1-D) mathematical model is developed to investigate PEMFC performance while explicitly accounting for water transport within the fuel cell during operation. The results demonstrate that the cell output performance is significantly affected by key operating parameters, including operating temperature, operating pressure, membrane thickness, exchange current density, and charge transfer coefficient. In addition, gas species transport and water management are incorporated into the model. The developed model is further applied to evaluate and analyze the dynamic performance characteristics of a hydrogen fuel cell electric motorcycle, including hydrogen consumption, water generation, and energy efficiency under the World Motorcycle Test Cycle (WMTC). This study provides a meaningful framework for predicting and designing the dynamic performance of hydrogen fuel cell electric motorcycles under realistic operating conditions.
Crashworthiness is a critical requirement for lightweight structures in automotive, electric vehicle and aerospace applications, where efficient energy absorption and controlled force transmission are essential. This review looks at more than 100 experimental, numerical, and analytical studies published between 2013 and 2025. It focuses on how materials, geometry, manufacturing processes, and loading conditions work together to affect the crashworthiness of thin-walled structures. Using a PRISMA inspired systematic narrative review combined with bibliometric and thematic analyses, key performance metrics: peak crushing force (PCF), mean crushing force (MCF), energy absorption (EA), specific energy absorption (SEA) and crushing force efficiency (CFE) are evaluated across metals, polymers, composites and hybrid systems, as well as non-tapered, tapered geometries under quasi-static and dynamic loading. The reviewed studies show that crashworthiness is best improved through a good combination of material, geometry, manufacturing quality and loading conditions. Hybrid structures are particularly promising, but their performance depends heavily on the interface quality, shape, and testing conditions.
The electrification of two-wheelers (E2Ws) is increasingly recognised as a high-impact decarbonisation strategy in emerging Asian markets, where motorcycles are the dominant mode of transport. However, the literature remains fragmented, and behavioural studies consistently report a persistent gap between stated adoption intentions and actual purchase behaviour. This study provides a robust empirical proxy to address these limitations through a two-phase hybrid approach: a Scoping Review and Bibliometric Analysis (ScoRBA) of 278 Scopus-indexed articles, synthesised using the PAGER framework, followed by empirical validation via a multi-model machine learning approach applied to a stated-preference dataset of 6,040 respondents from Solo, Indonesia. Bibliometric mapping identified three core socio-technical research clusters. The empirical analysis revealed a finding that departs substantially from prevailing assumptions: Perceived E-bike Quality, not financial incentives or operational costs, emerged as the dominant predictor of adoption. While initially identified via a baseline Decision Tree, this dominance was robustly validated across advanced ensemble algorithms and confirmed via SHAP analysis (Mean |SHAP Value| = 17.88%). Correctly situated within the Technology Perception dimension of the Technology Acceptance Model (TAM), this variable's dominance implies a sequential cognitive architecture: technology credibility must be established before economic evaluation becomes relevant. Consequently, policymakers in similar motorcycle-dominated transitional markets should prioritise quality certification and demonstration programmes before deploying purchase subsidies at scale.
The performance of hydraulic braking systems is strongly influenced by the condition of brake fluid, particularly boiling point and tendency to form vapor bubbles that may lead to vapor lock. Glycol-based brake fluids, such as DOT 4 and 5.1, are hygroscopic, causing moisture content to increase over their service life. Therefore, this study aimed to examine the effect of moisture percentage on boiling point and bubble formation characteristics of DOT 4 and 5.1 brake fluid. An experimental method was applied by adding distilled water to brake fluid at varying concentrations of 0%, 1%, 2%, 3%, and 4%, followed by gradual heating. The boiling point was recorded using a temperature sensor connected to a data logger. At the same time, bubble formation was visually observed during the heating process using a high-speed camera with a frame rate of 240 fps. The recorded images during the analysis were subsequently examined using ImageJ processing software. The results showed that increasing moisture content led to a significant reduction in boiling point for both types of brake fluid. At identical temperature levels, fluids with higher moisture content indicated larger bubble volume formation. These results indicated that moisture content played a critical role in degrading the thermal performance of brake fluid and increased the risk of vapor lock in automotive braking systems.
