background and objectives: lipases are valuable biocatalysts which are widely used in the detergent, food, dairy and pharmaceutical industries. the aims of the present study included the isolation of a lipase-producer from industrial zones and the partial characterization of the enzyme. materials and methods: a number of bacteria were isolated from sites related to the oil industries. an isolat...

the automobile industry’s wastewater not only contains high levels of suspended and total solids such as oil, grease, dyestuff, chromium, phosphate in washing products, and coloring, at various stages of chassis manufacturing but also, a significant amount of dissolved organics,resulting in high bod or cod loads. suspended solids can be removed from the wastewater by chemical precipitation. h...

in atom transfer radical polymerization (atrp) of methyl acrylate (ma) with polyvinyl acetate macroinitiator in bulk at 90°c the plots of ln [m]0/[m] increased linearly with reaction time. the apparent propagation rate constant (kp app) of the reaction was obtained from the linear curve and used to calculate the free macroradical concentration ([r°]) in polymerization medium. the [r°] and also ...

classical trajectory (monte carlo) calculation is used to calculate collision rate constants of ion-quadrupolar molecule interactions for the h¯+c2h2 system. the method presented here takes into account the effect of the induced dipole-induced dipole potential on ion-quadrupolar molecule collision rate constants. it is also assumed that the colliding particles have a definite size. the thermal ...

Classical trajectory (Monte Carlo) calculation is used to calculate collision rate constants of ion-quadrupolar molecule interactions for the H¯+C2H2 system. The method presented here takes into account the effect of the induced dipole-induced dipole potential on ion-quadrupolar molecule collision rate constants. It is also assumed that the colliding particles have a d...

Coming out from the growth kinetics, the Gompertz model has been developed and considered as the best one for simulating the biogas production from anaerobic digestion. However, the model has failed to describe the starting point of the process, and no-sense of lag phase constant has been pointed out. Thus, the goal of this study is to develop a new kinetic model of biogas production with meani...

Methods are described for estimation of kinetic constants from the integrated rate equations for a number of reaction mechanisms. In general, these ( methods depend upon elimination of either zero order or fist order terms between rate curves determined at two initial substrate concentrations or more. This operation is followed by graphic or statistical evaluation of the kinetic constants in th...

Reaction constants and heat release during thermophilic aerobic digestion of typical secondary and mixed sludges were determined. Maximum reaction constant, determined by measuring the amounts of biodegradable volatile suspended solids (bVSS) removed, occurred in the temperature range of 55-60 ºC. Measurement of heat releases were carried out, at the same range, by the aid of a temperature ...