Journal Issue

Proper curing of concrete is essential for attaining required strength and long-term durability. This study investigates Polyethylene Glycol-400 (PEG-400) as an internal curing agent for M20 and M30 grade concrete. Conventional and self-curing concrete mixes containing different percentages of PEG-400 were evaluated through compressive and split tensile strength tests at different curing ages. The results indicate that PEG-400 improves moisture retention and supports adequate strength development. A dosage of 1.5% PEG-400 produced the highest compressive strength, while 1.0% PEG-400 provided favorable tensile strength performance.

The vortex tube is a mechanical device without moving parts that separates compressed air into hot and cold streams. This study numerically investigates the flow behaviour and temperature separation inside a Ranque-Hilsch vortex tube with modified nozzle configurations. Three-dimensional CFD simulations are performed using ANSYS Fluent with an RNG turbulence model. Grid-independence testing and comparison with published numerical and experimental results are used to validate the simulation approach and assess the influence of nozzle geometry on vortex-tube thermal performance.

This study reviews modeling, simulation, optimization, kinematics and dynamic analysis methods used for robotic arm manipulators. The work represents an initial phase toward broader research involving robot trajectory generation. Recent approaches to kinematic and dynamic analysis, motion optimization and robot trajectory modeling are discussed with emphasis on improving the efficiency and performance of industrial robotic systems.

Arc welding is widely used for joining similar and dissimilar materials, and the quality of a welded joint depends strongly on process parameters such as current, voltage and welding speed. This study examines approaches for determining optimal welding-process settings to achieve desired weld quality and mechanical properties. The work reviews optimization methods capable of reducing the lengthy trial-and-error procedure traditionally used for selecting suitable welding parameters.

Composite materials consist of two or more constituents combined to obtain enhanced structural and mechanical characteristics. This survey discusses composite material classifications and their mechanical properties, with emphasis on analytical and numerical methods used to evaluate structural behaviour. Previous research involving laminated composite plates, vibration characteristics, finite-element methods and related numerical techniques is reviewed as a foundation for evaluating the mechanical strength of composite structures.

Die casting is a high-volume manufacturing process widely used for producing lightweight metal components with limited post-machining requirements. This study focuses on reducing defects in die-cast components through optimization of the gating system and process parameters. The influence of injection pressure and dimensional factors on component quality is considered. Response Surface Methodology, Genetic Algorithm techniques and ANOVA are used to evaluate process responses and identify influential parameters and their interactions.