A Study of the Dust Collection Process in the Production of Refractories

An experimental setup for studying filter-assisted dust collection is described. The role of various factors — hydraulic resistance, filtering velocity, dust concentration, pressure drop, efficiency of recovery — in the performance of filters intended for use in the production of refractory materials is considered. The dust removal method was tested under industrial conditions at the Semilukskii Refractory Plant and can be recommended for wider use in different branches of industry.     

Polyfunctional Properties of Liposomes in Preparation of Textile Materials

The stability of liposomal preparations in basic media and their wetting, detergent, and foaming power are evaluated. The results obtained indicate the promise of using liposomes as textile auxiliaries in preparation of textile materials of different fibre composition. The effectiveness of using liposomal preparations in peroxide bleaching of wool and fabrics made of hydrated cellulose fibres and blends of them with cotton and polyester fibres is established. The stabilizing effect of liposomes in the bleaching bath is demonstrated, which allows totally eliminating silicate stabilizers in bleaching of wool. Addition of liposomal preparations to the peroxide bath allows significantly increasing the quality of bleaching of textile materials.     

Stabilizability of the linear algebro-differential one-input control systems

Consideration was given to the controllable system of ordinary linear differential equations with the matrix at the derivative of the desired vector function that is identically degenerate in the domain of definition. For the one-input systems, the questions of stabilizability and solvability of the control problem by the Lyapunov indices were studied for the stationary and nonstationary cases. Analysis was based on the assumptions providing existence of the so-called “equivalent form” where the “algebraic” and “differential” parts are separated. An arbitrarily high index of insolvability and variable rank of the matrix at the derivative were admitted.     

Controllability of Linear Algebraic Differential Systems

A controllable linear system of ordinary differential equations not solvable for the derivative of the vector state function of the system is investigated. The coefficient matrix at the derivative of the vector state function is assumed to be degenerate at all points of the domain of definition. Controllability criteria for systems with constant and variable coefficient matrices are formulated in terms of input data.     

Use of alternating-current polarography for determining the lead and cadmium content of wheat grain

The authors studied the possibility of determining lead and cadmium in wheat grain by polarography in the presence of O. 1 N hydrochloric acid. The determination of lead and cadmium in the grain can be performed with the use of the addition method and the calibrating curve. However, during cadmium determination, the calibrating curve provides more reproducible results. Altogether 100 samples of wheat grown in different regions of the European part of the USSR were analyzed by polarography. The data obtained indicate that the content of lead and cadmium in wheat grain does not depend on the region where that culture was grown. It amounts to 0-0.2 micrograms/g for lead and 0-0.04 micrograms/g for cadmium for the majority of samples. If the content of these elements is higher than the amounts indicated, there is every reason to suggest that in this region there are sources of grain contamination with lead and cadmium.     

The surface-active compounds of a Pseudomonas sp. S-27 culture

Pseudomonas species S-27 was grown on various substrates. It was established that the Pseudomonas species S-27 strain can produce biosurfactants of ramnolipid nature decreasing the surface and interfacial tension to 29.2 and 0.05 mN/m. respectively, as well as a biopolymer stabilizing the emulsions with hydrocarbons and oils. The biosurfactant and bioemulsifier synthesis is shown to depend of the substrate nature.