Position Control in Integro-Differential Pursuit Games

A game problem of pursuit for a dynamic process described by a system of integro-differential equations is considered. Sufficient conditions are derived for its termination in a class of positional controls. Model examples illustrate the results obtained.     

Reducing the wear of motor components by polymer additions

The formation of a polymer coating from Ultra polytetrafluorethylene (PTFE) in frictional systems is analyzed, for the example of Forum antifrictional additive. Self-organization of the system is observed. The best frequency of additive introduction in the lubrication system of an automobile is determined.     

Wet vibro-grinding of zircon with surfactants

Conclusions An investigation was carried out of the effect of various surfactants added during the wet vibrogrinding of zircon on the degree of dispersion of the powder and on the sintering of specimens molded from the powders. When added in proportions up to 0.2% all surfactants tested (naphthenate soap, Asidol, titanium soap, GKZh-94, GKZh-10, triethanolamine, and sugar) helped to reduce the time required to grind the zircon to a given fineness from 15–20 to 4 h, i.e., by a factor of about 2.5–4.It was found that the proportion of fine fractions and the specific surface of the powder influence the open porosity and apparent density of the fired specimens. It was confirmed that sintering to an open porosity below 1% can be achieved with powders containing at least 80% grains finer than 5 including at least 60% grains finer than 2 which corresponds to a powder with a specific surface of at least 12 m²/g.It was established that in wet vibro-grinding a relation exists between the amount of accumulated iron grindings, on the one hand, and the degree of dispersion of the ground material and the apparent density of the fired specimens, on the other. The amount of iron grindings can serve as an indirect indicator of the suitability of the ground zircon for the production of superhigh density refractories. When wet vibrogrinding zircon it is recommended that an additive be used in the form of 0.05–0.1% triethanolamine.Translated from Ogneupory, No. 6, pp. 38–44, June, 1977.     

Etude voltamperometrique de la n-acetyl l-tyrosine amide sur electrode a pate de graphite en milleux aqueux I—comportement dans les domaines de balayage superieurs a 0,5 v/enh

Graphite paste electrode allows to determine elementary processes of the electrochemical oxidation in aqueous media of an electrochemical probe such as: N-acetyl L-tyrosine amide. Mathematical analysis of voltammograms gives the following EC mechanism: R?C₆H₅OH?R?C₆H₅O^. + H⁺ + e 2 R?C₆H₅O^. → R?C₆H₅O⁺ + R?C₆H₅O^?, R?C₆H₅O^? + H⁺ → R?C₆H₅OH, R?C₆H₅O⁺ → [R?C₆H₄O]^.. + H⁺, n[R?C₆H₄O]^.. → ?[R?C₆H₄O]^?_n.     

Matrix Resolving Functions in Dynamic Games of Approach

The concept of matrix resolving function is introduced to study dynamic game problems. The sufficient conditions are derived ensuring the possibility for the pursuer to bring the trajectory of a conflict-controlled process to the terminal set. The cases of using quasi-strategies and counter-controls by the pursuer are analyzed separately. Guaranteed times of the game termination for different method’s schemes are compared. The theoretical results are illustrated with a model example of “simple motions” on a plane.     

Thermomechanical effect in a cylindrically-hybrid nematic liquid crystal

Thermomechanical rotation of a cylindrically-hybrid nematic liquid crystal in the presence of a longitudinal temperature gradient is predicted theoretically and detected experimentally. Pis’ma Zh. Tekh. Fiz. 25, 71–73 (March 26, 1999)