one of the popular and well known models in boundary layer that is implemented in most of the operational and familiar models is the mellor-yamada model of atmospheric boundary layer. one reason that this model is so popular is its ability in simulations and exposing of different phenomena in the boundary layer. this model has been constructed based on second order closure hypothesis. beside al...

In this study, removal of Acid blue 62 from aqueous solution by mesoporous silicate MCM-41 modified by Aminopropyltriethoxysilane (APTES) composite was studied. Properties of synthesized composite were analyzed and confirmed by SEM, EDX and FTIR. Results show that Langmuir adsorption isotherm has the best compatibility with the results of experiments. Kinetic analysis using pseudo-first-order m...

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...

A mathematical model for commercial naphtha catalytic reformer of Tehran refinery was developed. This model includes three sequencing fixed beds of Pt/Al2O3 catalyst at the steady state condition using detailed kinetic scheme involving 26 pseudo-components connected by a network of 47 reactions, in the range of C6 to C9 hydrocarbons. The reaction network consisted dehy...

objective(s): in this work, electrospun nanofibers were explored as drug delivery vehicles using tetracycline as a model drug.  nanocomposite fibers including chitosan (cs)/poly (ethylene oxide) (peo) and antibiotic were successfully prepared using electrospinning. cs blended with peo considering a weight ratio of (90/10), and then, nanofibrous samples were successfully electrospun from their a...

for preventing groundwater and soil from heavy metal contamination and/or to decrease contamination, and to clean up the former disposal sites from these metals, one must be beforehand able to predict the movement of these pollutants in soils. in this research in order to describe cadmium [cd (ii)] transport in soils, we incorporated an equilibrium-kinetic two-site model into the convection-dis...

the bubble effectiveness in liquid phase cylohexane non-catalytic oxidation process is discussed in this paper. then the bubble effectiveness and a new proposed kinetic model are used in the mathematical model of the industrial reactor for the cyclohexane non-catalytic oxidation process. furthermore, simulation and optimization based on this reactor model are carried out. the results of simulat...

In this study simulation and optimization of an industrial acetylene hydrogenation reactor was studied. Three well known kinetic models were used for a nearly similar catalyst to predict the industrial data. Due to the complexity of the reactions, none of the offered kinetic models could be considered as an exact kinetic model and it is necessary to determine the kinetic parameters. One of the ...

A kinetic model of a fixed bed tubular reactor incorporating catalyst deactivation was developed for the ISOMAX unit of Arak refinery. The kinetic parameters for the hydrocracking reactions over the commercial catalyst were determined using initial activity plant data i.e. when the catalyst is fresh. Catalyst deactivation was then taken into account by means of deactivation function based on pl...

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...