National University of Malaysia

About: National University of Malaysia is a education organization based out in Kuala Lumpur, Malaysia. It is known for research contribution in the topics: Population & Heat transfer. The organization has 26593 authors who have published 41270 publications receiving 552683 citations. The organization is also known as: NUM & Universiti Kebangsaan Malaysia.

Studies on CO2 Adsorption and Desorption Properties from Various Types of Iron Oxides (FeO, Fe2O3, and Fe3O4)

Abstract: Various type iron oxides of FeO, Fe2O3, and Fe3O4 were used for carbon dioxide (CO2) capture at room temperature and pressure by studying its adsorption–desorption properties. Several interactions of carbonate species were detected on its surface. The morphology of carbonate formation shows different structures on FeO (grooves-like), Fe2O3 (fine sharp particles), and Fe3O4 (aggregated nanoparticles). CO2 chemisorption discovered a potential adsorbent of Fe2O3 with an adsorption capacity of 3.95 mgCO2/gadsorbent. The adsorption capacity increased up to 62.8% by using concentrated 99.9% CO2 for adsorption. At higher concentration of CO2 exposure, it partially turns to red color which indicated the less stable Fe3O4 was easily oxidized to Fe2O3 after CO2 regeneration with temperatures up to 500 °C. Hence, Fe2O3 possessed the highest basicity strength (1.26 cm3/g), and the adsorption capacity after four cycles was not significantly reduced by 8.6% indicating an effective chemical or physical adsorption in CO2...

Mixed convection stagnation point flow of a micropolar fluid towards a stretching sheet

Abstract: The mixed convection two-dimensional boundary layer flow of a micropolar fluid near the stagnation point on a stretching vertical sheet is investigated. The stretching velocity and the surface temperature are assumed to vary linearly with the distance from the stagnation point. The transformed ordinary differential equations are solved numerically for some values of the parameters involved using a finite-difference scheme known as the Keller-box method. The features of the flow and heat transfer characteristics are analyzed and discussed. Both assisting and opposing flows are considered. Results are presented in terms of the skin friction coefficient and the local Nusselt number with selections of velocity, microrotation and temperature profiles. Dual solutions are found to exist for the opposing flow.