for large and complex reacting systems, computational efficiency becomes a critical issue in process simulation, optimization and model-based control. mechanism simplification is often a necessity to improve computational speed. we present a novel approach to simplification of reaction networks that formulates the model reduction problem as an optimization problem and solves it using genetic al...

the effect of mechanical activation on structural changes and kinetics of carbothermic reduction of hematite with graphite was studied in this research. hematite powder mixture with graphite (with stoichiometry ratio c/o=1) was milled for the time periods of zero to 50 hours, and the structural changes were studied using x ray diffraction (xrd). the effect of mechanical activation on the kineti...

Methods to derive macroscopic transport equations for rarefied gases from the Boltzmann equations are presented. Featured methods include the Chapman-Enskog expansion, Grad’s moment method, and the author’s order of magnitude method. The resulting macroscopic equations are compared and discussed by means of simple problems, including linear stability, shock wave structures, and Couette flow.

in this work the kinetic data demanded for kinetic modeling were obtained in temperatures 350, 400, 450 and 500 oc by conducting experimentations on a fe-cr nanocatalyst prepared from a novel method and a commercial fe-cr-cu one. the collected data were subjected to kinetic modeling by using two models derived from redox and associative mechanisms as well as an empirical one. the coefficients o...