in this paper, a five–dimensional mathematical model is proposed for the transmission dynamics of hiv/aids within a population of varying size. in writing the model, we have divided the population under consideration into five sub classes of susceptible, infective, pre-aids, aids related complex and that of aids patients. the model has two non- negative equilibria namely, a disease free and the...

in this study, liquid-liquid extraction process in a kuhni extraction column was modeled and simulated. a non-equilibrium dynamic model was developed for modeling liquid-liquid extraction processes based on a rate-based model. the model equations are inclusive of partial and ordinary differential equations which were discretized in column height direction. the population balance model was used ...

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...

a procedure is presented that synthesizes fractional crystallization separation processes to obtain pure solids from multi-component solutions. the method includes a procedure to generate a network flow model to identify alternative process designs for fractional crystallization. the main advantage of this systematic procedure with respect to other reported procedures is using non-equilibrium s...

in this study, nano-tio2 was employed for the adsorption of chloroform from aqueous solution in batch equilibrium experiments to investigate its adsorption properties. the effects of ph, initial chloroform concentration and nano-tio2 dosage were also investigated. optimal conditions for chloroform removal by nano-tio2 have been then identified. results of equilibrium experiments showed that the...

the molecular sieves are selective adsorbents. they can adsorb some kind of molecules that are different in size or shape from the others. in separation of n-paraffins from iso-paraffins and aromatics, sa molecular sieve is the suitable adsorbent, and can adsorb n-paraffins to separate them from other hydrocarbons. in this paper equilibrium isotherms of n-cs, n-c6 and n-c7 from an inert solvent...

In this study, nano-TiO2 was employed for the adsorption of chloroform from aqueous solution in batch equilibrium experiments to investigate its adsorption properties. The effects of pH, initial chloroform concentration and nano-TiO2 dosage were also investigated. Optimal conditions for chloroform removal by nano-TiO2 have been then identified. Results of equilibrium experiments showed that the...