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This paper presents an experimental study of epoxy and sisal fibre composites with and without potassium permanganate and stearic acid treatment. A compression moulding technique was used to develop the composites. Differential Scanning Calorimetry (DSC), tensile and flexural tests, and scanning electron microscopy were used to investigate the thermal and mechanical behaviour of these composites. SEM images of sisal fibres revealed improvements in the fibre's surface topography further to the surface stearic acid treatment process. X-ray diffraction (XRD) analysis reveals that sisal fibre is crystalline in nature. When sisal fibre was treated with streaic acid, the tensile strength increased to 43.45 MPa. Potassium permanganate-treated fibre reinforced composites demonstrated high potential flexural strength. SEM analysis revealed that stearic acid-treated fibre improved interfacial adhesion between the fibres and matrix.

The effect of a heat source and temperature gradient on Brinkman–Bènard Triple-Diffusive magneto-Marangoni (BBTDMM) convection in a two-layer system is investigated. The two-layer system is horizontally infinite and is surrounded on all sides by adiabatic boundaries. It is exposed to basic uniform and non-uniform temperature profiles and heat sources. The appropriate eigenvalues and thermal Marangoni numbers (TMNs), which depend on temperature and concentration, are obtained for the temperature profiles (TPs) for lower rigid and higher free boundaries with surface tension. The transformed system of ordinary differential equations is solved by using an exact technique. For all three TPs, the impact of significant relevant parameters on these eigenvalues, and hence on BBTDMM convection, are investigated versus the thermal ratio. It is observed that, by increasing the values of the modified internal Rayleigh number for the fluid layer and the solute Marangoni numbers, the Darcy number, and the viscosity ratio for the set of physical parameters chosen in the study, one can postpone BBTDMM convection. Higher values of the modified internal Rayleigh numbers for the porous layer augment BBTDMM convection. [ABSTRACT FROM AUTHOR]