Transformation Of Reagents Research Articles

Assessment of the Environmental Consequences Caused by Endogenous and Anthropogenic Hazards for the Azov Recreation Area

The Russian sector of the Azov recreational area is under the influence of numerous pollution sources of anthropogenic or natural origin. To ensure a comfortable recreation and recovery of the population, it is necessary to apply methods of integrated system monitoring, which makes it possible to identify patterns of the pollution formation in heterogeneous areas of the territory and places of increased environmental risk. Mathematical and simulation modelling should be an integral part of such systems, as a tool for scenario analysis, forecasting and warning. The paper proposes cellular automaton modelling methods, which have the advantages of expressivity, which allows for expansion of the possibilities for studying complex physicochemical processes and phenomena associated with the migration and transformation of reagents in the atmosphere and in the aquatic environment. The method is implemented in the form of a software application. We also present the results of the simulation of diffusion process and two substances - products of combustion in a fire with a point localization of epicentres; independent dispersion and interaction of light fractions of emission products upon activation of a land volcano and heavy fractions of mud volcano breccias of an underwater mud volcano.

Stability of carbon monoxide oxidation process on gold nanoparticles

The stability conditions for mathematical models of carbon monoxide oxidation on the surface of gold nanoparticles are investigated. The cases of reaction mechanisms of one-step and step-by-step transformation of reagents are consecutively considered. Using the stability analysis by Lyapunov method, it is shown that models which take into account the possibility of structural changes of the catalyst surface can predict the occurrence of oscillatory mode in the system as a result of Hopf instability.

Kinetics and mechanism of formaldehyde oxidation—II

Using the method of quasistationary concentrations, the kinetic equations proposed for the mechanism of high temperature formaldehyde oxidation are solved for the reaction taking place in a reactor treated by boric acid, taking into consideration the transformation of reagents in the course of the reaction, and using the Runge-Kutta method of numerical integration of a system of differential equations on Razdan-3 Computer in Algol-60 language. Agreement was obtained between the calculated and experimental values of the maximum rate of the consumption of CH2O, maximum concentrations of H2O2 and the radical HO2 for realistic values of the rate constants of the reaction steps. Calculations for reactors treated by KBr or K2B4O7 fit experimental results, if the rate constants for the removal of HO2 and H2O2 on the walls are increased by one order of magnitude.