Mathematical modeling in chemical engineering and biotechnology

This article reviews publications in Russian journals on mathematical modeling in chemical engineering and biotechnology. The major emphasis is on crystallization, mass transfer, and dissolution in chemical engineering processes, as well as steady and unsteady states in biotechnology. Two approaches to modeling in biotechnology are considered: structured and unstructured approaches.     

Nonequilibrium heteroepitaxy of silicon carbide on silicon

A method of silicon carbide (SiC) deposition onto silicon via a nonequilibrium disilicon carbide (Si₂C) vapor phase is proposed, theoretically described, and experimentally verified. Estimates obtained using thermochemical calculations show that a sufficiently large number of SiC molecules, which are transported by mobile Si₂C species, are obtained using this method on the silicon surface. It is established that homogeneous epitaxial SiC layers can be grown on a Si(111) substrate surface.     

Effect of the Active Region and Waveguide Design on the Performance of Edge-Emitting Lasers Based on InGaAs/GaAs Quantum Well-Dots

Semiconductors - Edge-emitting lasers with active regions based on novel InGaAs/GaAs quantum heterostructures of transitional dimensionality, i.e., quantum well-dots, which are intermediate in...     

Visualization Methods and Algorithms for Graph Representation of Functional Programs

Programming and Computer Software - This paper is devoted to the visualization of intermediate representations (the so-called IR graphs) of programs in the Cloud Sisal functional language for the...     

Simulation of Drying on the Basis of Nonequilibrium Thermodynamics of Beterogeneous Multiphase Polydispersed Systems.Formation of the Morphological Structure of Emulsive Elastomers Using Method of Spray - Drying for Latexes

ABSTRACT

The process and the technology of fine - dispersed rubber powder production on the basts of spray - drying for latexes were considered. The practical recommendations on usage of physical modification method for elastomers on the basis of interaction mechanism between solid -phase dispersed filler and polymeric panicles were given.

The mathematical model for latex drops during drying in the presence of structured adsorptive layer of surface active substances on the surface of drops was worked out, that allowed us to give the recommendations for production of monolithic particles.     

Steady states of a biotechnological process for producing lactic acid at a given dilution rate

Conditions are determined that ensure the presence of steady states in a continuous biotechnological process for producing lactic acid. The possibility of implementing multiplicity depending on the kinetic parameters and the inlet values of the characteristics of the synthesis process is shown. An algorithm is developed for evaluating the multiplicity of steady states and calculating the characteristics of the process under the conditions of multiplicity.     

On developing a magnetorheological transformer that operates in orthogonal magnetic fields

The operation of a magnetorheological transformer in which choke channels are replaced with a cylindrical clearance between two coaxial cylinders is considered. The cylindrical clearance, as well as the working and compensation chambers, are filled with a magnetorheological fluid. It has been shown that this design of the magnetorheological transformer is preferable for damping impact loads.