in this research, rice husk and activated carbon adsorbents were used for removal of lead ion from aqueous solution at ph= 6. in the batch tests experimental parameters were studied, including contact time and initial metal ions concentration.survey of the equilibrium time at different concentration showed that equilibrium time is reduced with decrease of initial concentration of solution from ...

the aim of this paper is to examine and analyze the spatial distribution of population in cities of the southern coastal region of iran by using common models and techniques in the field and to study the trends of evolution in a time period of 40 years (1345-1385). models used in the study can be classified into three main groups. the first group is the primate city indexes (including jefferson...