in this paper, the adsorption of cerium on modified mesoporous aluminosilicate (with si/al mole ratio of 10) was studied. the effects of ph, contact time, initial concentration of cerium on adsorption of cerium were investigated. the adsorption capacity was high in the ph range of 4-8 and decreases with decreasing of the ph value. the langmuir and freundlich isotherms were applied to represent ...

INTRODUCTION One of the ethical issues surrounding birth cohort studies is how to obtain informed assent from children as they grow up. What and how parents tell their children affects children's future choices about the study, yet few studies have focused on parents' influence on children. OBJECTIVE This study examines parents' attitudes towards telling their children about their participati...

Conceptual modelling has emerged as a means to capture the relevant aspects of the world on which it is necessary to provide information. Whereas conceptual models succeeded in telling us how to represent some excerpt of the world in informational terms, they failed to guide system analysts in conceptualising purposeful systems, i.e. systems that meet the expectations of their users. This chapt...