a catalytic-kinetic method for the determination of selenium is proposed. alizarin navy blue is reduced by sodium sulfide to from a colorless product. the reaction is accelerated by trace amounts of se (iv), and can be followed by measuring the decrease in absorbance of the dye at 620nm and 30 °c by the fixed time method. selenium can be determined in the range of 0.004 — 0.12 1.1g.m1-1 . ...

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 ...

this paper considers a class of one-dimensional solidification problem in which kinetic undercooling is incorporated into the temperature condition at the interface. a model problem with nonlinear kinetic law is considered. the main result is an existence theorem. the mathematical effects of the kinetic term are discussed

the kinetic of photo oxidative decolorization of c.i. acid yellow 23 (ay23) was investigated in uv/ process. the semi-logarithmic of the concentrations of ay23 versus irradiation time were linear, suggesting pseudo-first order reaction. a simple kinetic model is proposed which confirms pseudo- first order reaction. the results indicate that the apparent reaction rate constant is a function of l...