V2O5/SiO2 catalyst was utilized to oxidize SO2 to SO3 species in the presence of oxygen mainly for producing sulfuric acid. For this catalyst, the active phase was a mixture of vanadium pentoxide and basic sulfate/pyrosulfate material. This active phase at the reaction temperature behaved as a liquid filling up the pores of the silica support. On the other hand, amounts of the SO3 and V5+ speci...

effect of water gas shift reaction (co+h2o=co2+h2) on wustite reduction has been investigated by a transient, non-isothermal mathematical model based on grain model. in this model, wustite porous pellet is reduced using syngas, namely a mixture of hydrogen, carbon monoxide, carbon dioxide and water vapor. for this purpose, governing equations containing continuity equation of species and energy...

3,4-dihydropyrimidinones and their derivatives are synthesized via biginelli routes involving an aromatic aldehydes, ethylacetoacetates and urea in one-pot procedure by using cds nanoparticles as efficient heterogeneous catalyst in solvent-free conditions. compared with classical biginelli reaction reported in 1893, this new method provides much improved modification in terms of simplicity. the...

Simultaneous determinations exploiting the rates of reactions of different analytes with a common reagent, often referred to as differential kinetic analysis, is efficiently implemented in the flow analyser. To this end, specific strategies for pumping, commuting and/or detecting have been proposed. This review critically discusses the potentialities, limitations and application ranges of the d...

the olefins polymerization process in a slurry reactor is discussed. the reaction rate dynamics was analyzed and the contributions of feed flow, gas-liquid mass transfer, polymerization reaction, and catalyst deactivation were estimated. the propylene solubility in a solvent mixture “heptane” was calculated using soave-redlich-kwong equation of state. these data were then approximated by henry-...

mantoux test using 2 iu of tuberculin prepared in iran was performed on 6675 healthy persons randomly selected from an urban population (shiraz) of iran. in 3776 persons with no evidence of previous bcg vaccination the rate of positive reaction was less than 2% up to the age of 14, slightly more than 2% among those 15-19 years of age, but strikingly higher (45.5%) in older age groups (p<0.001)....

We show in detail how the presence of a heat bath of photons effectively gives charged particles in the final state of a decay process a temperature-dependent mass, and changes the effective strength of the force responsible for the decay. At low temperature, gauge invariance causes both these effects to be largely cancelled by absorption of photons from the heat bath and by stimulated emission...