Asmalina Mohamed Saat

The objective of this research is to explore the nature of non-linear flow and heat transfer of the Casson fluid at the stagnation region in view of variable surface heat flux, viscous dissipation, and temperature-dependent thermal properties of the fluid. The model developed here represents the influence of non-linear rheological behavior, surface thermal loading, viscous heating, and variations in fluid properties on flow dynamics. The nonlinear boundary layer equations are reduced to a dimensionless form and solved using the Residual-Based Adaptive Parametric Physics-Informed Neural Network (RAP-PINN) method. This is an improvement on traditional numerical solution methods, which repeatedly solve each parameter combination separately. The new approach incorporates the physics into the training algorithm and places more importance on regions where there are higher residual errors. This allows the network to learn the physics-based solution for different governing parameters while keeping the accuracy of the solution high. An investigation of the influence of velocity ratio parameter, Casson parameter, Eckert number, and variable property parameters on the velocity, nanoparticle concentration, and temperature profiles along with their respective heat and mass transfer behaviors is conducted. Comparison with already published results shows very good consistency, which once again verifies the efficiency, accuracy, and reliability of the presented RAP-PINN approach in solving the present nonlinear problem. The suggested model can be used especially in the fields of thermal management, coating and polymer processing, cooling processes, and other engineering applications that involve non-Newtonian fluids under non-uniform thermal boundary conditions.

Hybrid natural and synthetic fibre composites are gaining significant attention as sustainable reinforcement materials. However, hybridization of natural fibres like kenaf with synthetic fibres such as fibreglass for marine applications remains unexplored and the underlying system and mechanisms are yet to be fully understood. This study presents the mechanical characterization of a novel green marine composite hybrid reinforced with kenaf fibres and fibreglass, fabricated via the resin infusion method. The research focuses on developing an eco-friendly, sustainable composite material aimed at marine structural applications. Kenaf, a natural fibre, combined with fibreglass, enhances the mechanical performance while reducing environmental impact compared to conventional composites. The composite was fabricated using an optimized infusion technique and its tensile, flexural and impact properties were systematically evaluated. Results show that the hybrid composite exhibits improved strength and durability, suitable for marine environments, with the added benefit of sustainability. Hybrid kenaf/polypropylene/woven roving fibreglass hybrid composite shows highest in tensile strength and least percentage of water absorption. Meanwhile hybrid kenaf/polypropylene/chopped strand mat fibreglass hybrid composite possess highest in flexural strength and impact strength. This work contributes to the advancement of green materials engineering, aligning with Sustainable Development Goals (SDGs) 9 (Industry, Innovation and Infrastructure), 12 (Responsible Consumption and Production) and 14 (Life Below Water), by promoting sustainable industrial innovation, reducing synthetic fibre use and protecting marine ecosystems. The findings highlight the potential of natural fibre-reinforced hybrid composites as viable alternatives in marine applications, supporting environmentally responsible manufacturing and resource conservation.