Numerical demonstration of fluctuation dynamo at low magnetic Prandtl numbers

Direct numerical simulations of incompressible nonhelical randomly forced MHD turbulence are used to demonstrate for the first time that the fluctuation dynamo exists in the limit of large magnetic Reynolds number Rm>1 and small magnetic Prandtl number Pm<1. The dependence of the critical Rmc for dynamo on the hydrodynamic Reynolds number Re is obtained for 1 less than or similar Re less than or similar 6700. In the limit Pm<1, Rmc is about 3 times larger than for the previously well-established dynamo at large and moderate Prandtl numbers: Rmc less than or similar 200 for Re greater than or similar 6000 compared to Rmc approximately 60 for Pm>or=1. It is not yet possible to determine numerically whether the growth rate of the magnetic energy is proportional, Rm1/2 in the limit Rm-->infinity, as it should be if the dynamo is driven by the inertial-range motions at the resistive scale.     

Composites based on doped polyaniline and polyimide with tricyclodecene structures in the backbone

Conducting composites based on an alicyclic polyimide and polyaniline doped with nonylnaphthalenesulfonic acid or with undoped polyaniline were prepared. Their physicomechanical and electrical properties were studied. The accelerating effect of conducting polymers on the polycondensation was demonstrated.     

Composite films based on an alicyclic polyimide and a natural mineral,montmorillonite

Specific features of preparing composites of an alicyclic polyimide with various forms of montmorillonite were studied. The kinetic parameters of the polyimide formation under the conditions of the onestep polycondensation in the presence of the modified mineral were determined, and some physicomechanical and thermal properties of the films were examined.     

Synthetic and natural polymers as drug carriers for tuberculosis treatment

Drug forms based polymer carriers of prolong action were created for toxicologic effect of drug to be reduced in spite of long treatment of diseases. In present work a number of synthesis and natural polymers have been studied as carriers of antituberculous drugs for controlled delivery application. Following as drugs as isoniazid and ethionamide were incorporated into polymeric matrix (segmented polyurethanes, polyvinyl alcohol) and chemically bound with the polymer chain by covalent or electrostatic forces (aldehyde- and carboxymethylderivatives of polysaccharides). Biodegradation of polymeric systems and the release of drugs were studied by various physico-chemical methods. It was shown that the drug release depends of method of the immobilization, type of the drug/polymer bonding, drug loading. The bacteriostatic activity of obtained systems was determined. The possibility of tuberculosis treatment was proved in experiments of animals.     

Spectral Decompositions for the Solutions of Lyapunov Equations for Bilinear Dynamical Systems

Doklady Mathematics - In this paper, novel spectral decompositions are obtained for the solutions of generalized Lyapunov equations, which are observed in the study of controllability and...     

Spectral decompositions for the solutions of Sylvester,Lyapunov, and Krein equations

Doklady Mathematics - Spectral decompositions for the solutions of Lyapunov equation obtained earlier are generalized to a more general class of solutions of Krein matrix equations including as a...     

Justification of the Steepest Descent Method for the Integral Statement of an Inverse Problem for a Hyperbolic Equation

Under consideration is the steepest descent method for solving the problem of determination of a coefficient in a hyperbolic equation in integral statement. The properties of solutions to the direct and inverse problems are studied. Estimates for the objective functional and its gradient are obtained. Convergence in the mean is proved for the steepest descent method for minimizing the residual functional.     

Polymeric composites based on alicyclic polyimide and polyaniline

Specific features of modification of an alicyclic polyimide with polyaniline were examined. The thus obtained new polymeric composites exhibit better capability for silver plating.