Strain-energy failure criterion for rigid-plastic bodies

In the framework of the theory of strain-hardening rigid-plastic bodies, we suggest a strain-energy failure criterion. The strain states of a rigid-plastic body are depicted as points in the principal strain space and form a third-order hyperbolic surface for incompressible bodies. The strain processes are depicted by lines on this surface. The loading surface related to the strain surface lines is introduced, which permits calculating the energy dissipation as a parameter determining the failure.     

Laser-induced transport of atoms from an illuminated region in a gas

A new optical effect in the transport of atoms in dense gases, capillaries, and porous media is predicted. The origin of this effect lies in superelastic collisions of excited atoms, which give rise to thermal diffusion processes. Model estimates are made for the magnitude of the effects in the absence of flows and in the presence of flows in capillary systems. It is shown that under certain assumptions regarding superelastic collisions of atoms with the walls, the optical effect changes the transmission of a capillary. Zh. Tekh. Fiz. 68, 9–13 (May 1998)     

Regulating aspects of biosoluble and insoluble film release systems containing protein proteinase inhibitor

New types of potent aprotinin-containing medicinal polymer films are elaborated for topical applications. The higher the temperature of drying, the lower the steam absorption, the film swelling, and the velocity of aprotinin in vitro release. The presence of antimicrobials having the basic functional groups contributed to compacting the structure of the films and retention of aprotinin in them. The velocity of aprotinin release from the films is regulated by adding different polymers. Inclusion of polyvinylpirrolidone in the film resulted in acceleration and increase of aprotinin release. This was probably because of increasing the film swelling by a factor of 1.7. Additional retention of the inhibitor in films was achieved by inclusion of sodium alginate and cellulose powder capable of binding aprotinin. Soluble bioadhesive films derived from a copolymer of acrylamide,N-vinyl-pirrolidone, ethyl acrylate (M _r 30,000-600,000) and aprotinin were obtained and analyzed. Kinetics of aprotinin release from biosoluble films was studied under various conditions. The duration of aprotinin release was comparable with duration of gradual dissolution of the matrix. Bioavailability of aprotinin from soluble films was linear with time.     

The Steinhaus theorem on equiconvergence for functional-differential operators

We establish the equiconvergence of the series S(af) and a(x)S(f), where S(f) is the Fourier series in the eigenfunctions and associated functions of a certain functional-differential operator with involution.     

Reaction of 3-azidoisoxazoles with active methylene compounds

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Statistical calculations of tracer and intrinsic diffusion coefficients in concentrated alloys and estimates of microscopic parameters of diffusion from experimental data

The earlier-developed statistical theory of diffusion in concentrated alloys based on the master equation approach is generalized to treat tracer diffusion in binary alloys. The theory developed is used to describe concentration dependencies of both tracer and intrinsic diffusion coefficients and to estimate microscopic parameters of diffusion in alloys CuNi, CuZn and AgCd for which necessary experimental data are available. We show that all main features of strong and peculiar concentration dependencies of diffusion coefficients observed in these alloys are naturally explained by the theory. Signs and scales of interatomic interactions important for diffusion in these alloys are found to strongly depend on the ratio of atomic sizes of alloy components, and types of these dependencies agree with simple physical considerations. We also discuss physical reasons for sharp concentration dependencies of diffusion coefficients characteristic of real alloys.