In this study, preparation of adsorbent from Merremia emarginata stem and its application for the adsorption of chromium (VI) from aqueous solution was studied. The batch adsorption experiments were carried out to study the effect of contact time, adsorbent dose, effect of pH and effect of other ionic concentration on the removal of chromium (VI) by activated carbon. The equilibrium adsorption data were analyzed by Freundlich and Langmuir isotherm models. The thermodynamic parameters such as change in free energy (G°), enthalpy (H°) and entropy (S°) were determined. Kinetic modeling of the process of removal was carried out and the process of removal was found to follow a pseudo-second order model, Elovich model and Intraparticle diffusion model the value of rate constant for adsorption process was calculated. This study indicated that activated carbon Merremia emarginata, which is inexpensive, has efficiency to remove chromium (VI) from aqueous solution.

Cognitive assistance in knowledge engineering is a growing concern and information visualization is a very useful means to address this. This paper identifies some requirements for ontology visualization tools offering cognitive assistance and presents solutions with simple knowledge representations. This paper also identifies some of its features and describes areas need to be improved for effective visualization.