Mechanics

Asymptotic methods for obtained solutions in vicinities of wave fronts in viscoelastic rod at large time

Authors: Anofrikova N. S., Kossovich L. Y., Chernenko V. P.

Non-stationary longitudinal waves in viscoelastic rod at large time are considered. Equations for the wave fronts are derived by means of asymptotic methods. Solutions of these equations are obtained.

T-irreducible extension for unions of complete graphs

Authors: Kurnosova S. G.

T-irreducible extension is one of kinds of optimal extensions of graphs. Constructions of optimal extensions are used in diagnosis of discrete systems and in cryptography. A graph H with n+1 vertices is called an extension of a graph G with n vertices if G can be embedded in every maximal subgraph of H. Any graph Ghas the trivial extension that is the join ng+of G with some outer vertex v. T-irreducible extensions are obtained from the trivial extension by removal of maximal number of edges in such a way that the extension property is preserved.

Research into the time-depended transactional processes in viscoplastic fluids

Authors: Safronchik M. I., Safronchik A. I.

The paper presents problem of transition from one steady-state conditions of viscoplastic fluid flow to another between parallel planes. The problem definition is given within the limits of five- parameter model, which permits to take up differences between behavior under stress and without stress and possible slippage along the solid walls. Hysteresis of deformation is considered by means of model of smooth transition from adhesion to slippage. The solution is determined by method of momentary eigenfunctions of Melamed-Grinberg.