Selection of efficient control circuits for a tram traction electric drive on the basis of development of a simulation model

The development of simulation model for a tram traction electric drive with asynchronous motors using the MATLAB program in the SimPowerSystems application is considered.     

Direct Catalytic Oxidation of Hydrogen Sulfide

Hydrogen sulfide– containing natural gases are considered a fundamental source for obtaining elemental sulfur due to depletion of natural reserves. The basic industrial method of extraction of hydrogen sulfide from natural gases with production of elemental sulfur is the Claus method. The method of partial catalytic oxidation of hydrogen sulfide, which does not require preliminary treatment of the gases and concentration of the hydrogen sulfide, is more promising. This method is being increasingly used in industry.     

Modeling deflection of 450-GeV protons in a bent silicon crystal

It is shown that the numerical solution of the kinetic Fokker-Planck equation (proposed by Kitagawa and Ohtsuki in 1973) by means of computer simulation of the trajectories of channeled particles using the PST program describes the experimental data on the deflection of 450-GeV protons in a bent silicon crystal well.     

Injectional Equilibrium Spin Polarization in a Magnetic Transition,Taking into Account the Electron Spin Mobility

Journal of Communications Technology and Electronics - Taking into account the electron spin mobility, the paper considers the numerical solution to the equation for nonequilibrium spin...     

Applied kinetics of styrene suspension polymerization

In order to describe the kinetics of styrene suspension polymerization, it was proposed to apply the concept of the organized space of experiment formed by the results of kinetic experiments at different combinations of initial conditions, the properties of which can be determined using factor analysis. For this purpose, a 5 × 5 matrix of experiments performed at five temperatures and five initiator concentrations was implemented. Using the reduction of the obtained curves to the unified dimensionless time scale and performing the merge and ordering operation on the curves, it was shown that the introduction of seven empirical parameters was sufficient for the complete characterization of the entire space. A semi-empirical dependence of the monomer conversion on the dimensionless time was obtained; it was adequate to the experiment.     

Increasing the Efficiency of Terahertz Generation during the Current Flow through Magnetic Junctions Formed by Inhomogeneous Ultrathin Films of a Ferromagnetic Metal

Operating modes of terahertz (THz) generators with “rod–film” magnetic junctions formed by a Fe rod with one pointed end with a diameter of 10–50 nm and various nanometer-thick (single-layer and multilayer) Со films are studied. It is demonstrated that the efficiency of the THz radiation increases (due to an increase in the current density) if the thickness of a single-layer film decreases to the point when it becomes discontinuous (ultrathin) while retains its conductivity. If a multilayer structure with several such films separated by nonmagnetic conductive layers is used, the radiation power can also be increased.     

Surfactant effect on the catalytic synthesis of 4,4-dimethyl-1,3-dioxane

The main problem of 4,4-dimethyl-1,3-dioxane synthesis is the phase separation arising from the mutual insolubility of the aqueous phase, which contains formaldehyde and an acid catalyst, and the hydrocarbon phase, which contains isobutylene. Isobutylene condensation with formaldehyde has been investigated for the first time in the presence of surfactants with the aim of increasing the efficiency of the process. Surfactant admixtures provide high selectivity and a high reactant conversion, thus allowing the starting material consumption rate to be reduced. The surface and interfacial activities of the admixtures are evaluated. It is assumed that the surfactants cause the formation of microemulsions in the reaction medium and bring about micellar catalysis.