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A Rail-Conveyor can be used as one of solutions for transportation of coal production. This system was rated to have either a competitive capital investment, and operational & maintenance cost, when compared with conventional transportation system.This paper studies a stability analysis of the wagon of the Rail-Conveyor in order to prevent derailment in longitudinal and lateral directions. The main aims of this study are to determine the maximum acceleration, deceleration, operational velocity for all possible conditions such as incline slope, decline slope, and turning with a specific radius. Case study was conducted for the wagon diameter of 0.76 m. The loading conditions were classified into two cases: empty wagon and fully-loaded wagon. It was assumed that the maximum allowable slope was 20%. The result of this analysis will be used as a basic design for rail-conveyor operation, route selection, and power station location & its capacity.

The establishment of decentralized drinking water systems in urban areas is technically and financially feasible, and these 'off-grid' systems can complement investment in traditional piped water systems. However, users often see ‘off-grid’ systems as the second-best option, compared to citywide piped water systems. Thus, although they are designed to improve access to water and reduce inequality, they can be perceived by users as infrastructural manifestations of extant inequality. In this paper, we present original research on the perceptions of users in Cimahi, Indonesia, surrounding their access to water and willingness to use and maintain ‘off-grid’ infrastructure. The majority of respondents used groundwater and packaged water as their primary water sources, and paid approximately twice the maximum tariff of piped water service. We interpreted the survey data with the theory of planned behavior framework and determined that respondents demonstrated a willingness to pay fees for ‘off-grid’ water systems, participate in water supply programs, and switch to new water sources. These intentions were affected by their attitude towards the behavior, subjective norm, and perceived behavioral control to various degrees. The findings are useful for those designing strategies to introduce novel water delivery systems aimed at improving water access for diverse and disadvantaged socioeconomic groups in urban areas in the Global South.

There have been several attempts to solve Hertz equation for curved surface contact problem. One application of Hertzian contact problem is to determine the contact properties between wheel and rail. It is important to understand the contact between wheel and rail so that excessive wear can be avoided and train accidents can be minimized. In this work, an attempt has been made to solve Hertzian contact for small radius of curvature using a simple newly invented formula. A finite element modeling was also performed to observe the variations of maximum contact stress in rail with respect to the change rail radius of curvature. The invented formula was to modify the formula of Fischer et.al especially for the major and minor axis so that a more accurate result was obtained in determining the contact dimensions and maximum contact pressure.

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The split Hopkinson shear bar (SHSB) test is a modification of the high rate-impact test using a split Hopkinson pressure bar (SHPB). The SHSB has been developed for a variety of techniques, for example, the hat-shaped (circular or flat), double-notch, and punch (with or without notch) techniques. The main purpose of this study was to compare these three techniques to determine the shear stress-shear strain of aluminum alloy 2024-T351. The study was conducted using the Abaqus/CAE® software. The circular hat-shaped and punch (with and without notch) techniques used a quarter-section solid 3D model. The flat hat-shaped and double-notch techniques used a half-section solid 3D model. This study successfully tested and compared the three SHSB techniques, with a number of considerations, i.e. the same parameter values for kinetic energy, shear area and shear angle. Each technique has its own advantages and disadvantages in terms of force equilibrium, flow stress fluctuation, constant strain rate, machine-ability, ease of experiment, etc. The optimum technique among the three is the hat-shaped technique.

Cellular structures can be classified into foams, honeycombs, and lattice structures. Each type of structure has its characteristics. Various applications of cellular structures can be found in aviation, bioengineering, automotive, and other fields. In the automotive sector, cellular structures have been used for structural applications and impact- absorbing modules, for example, for protecting the electric vehicle battery pack against impact loading. The challenges that limit the application of cellular structures today include systematically designing pseudo-random cellular structures, assessing which cellular patterns are most suitable for a particular application, and mastery of manufacturing technology for efficient mass production of cellular structures. In this paper, the authors examine the state-of-the-art technology in geometry, applications, and manufacturing of various cellular structures carried out by researchers to obtain an overview of the current conditions for further development of these cellular structures. Limited manufacturing capabilities encourage researchers to design an optimal cellular structure to be applied to a particular function but have high manufacturability. The development of additive manufacturing technology has provided opportunities for researchers to produce an optimal cellular structure commercially soon.