Time filter

Source Type

Zalutski A.A.,Yaroslavl State Technical University
Protection of Metals and Physical Chemistry of Surfaces

Using a technique that is developed using Mössbauer spectroscopy, parameters of the diffusion motion and data on geography of the exchangeable iron complexes on a silica–alumina surface of clays were presented. The analyzed natural causes of the temperature behavior of the dynamic Mössbauer parameters allowed the pattern of the atoms' motion to be determined on the basis of various models of diffusion motion. For iron atoms adsorbed in the interwrapper space of the mineral, a jumplike translational diffusion is typical, which allowed determination of the sizes of the fluctuation hollow (r ~ 0.16 nm) necessary for the diffusion of atoms. A nonisotropic character of the diffusion for the interlayer and surface iron atoms caused by structural anisotropy of a clay substrate and by the structure of the iron complexes themselves was found. The surface diffusion of iron dimers occurs in a bounded area (L ~ 0.25 nm) and is rotational. © 2016, Pleiades Publishing, Ltd. Source

Simakov N.N.,Yaroslavl State Technical University
Technical Physics

The effect of the incoming flow geometry on the hydrodynamic drag of a body is investigated in a numerical experiment simulating a free gas flow past a sphere as well as flows in cylindrical tubes of various radii, in a confuser, and a diffuser. The results of calculations lead to the conclusion that the confinement of the flow by the tube walls, its contraction and expansion may change the hydrodynamic force and the drag acting on the body insignificantly (not more than by 30%). This cannot explain the early drag crisis, in which the values of these quantities decrease by 4-7 times for Reynolds numbers on the order of 100. This phenomenon is explained theoretically by the effect of strong turbulence of the incoming flow to the body. © 2011 Pleiades Publishing, Ltd. Source

Simakova M.N.,Institute of Complex Systems | Simakov N.N.,Yaroslavl State Technical University
Molecular Biology

The structure of membrane proteins specifies their functional properties, which are important for medicine and pharmacology and, therefore, is of significant interest. The repetition of transmembrane regions that consist of hydrophobic amino acids is a characteristic and organic feature of polytopic membrane proteins. The ordered repetition (periodicity) can be detected by the Fourier method applied to a digital image of the symbolic amino acid sequence of a protein. In the present work, this investigation was carried out for 24 transmembrane proteins (successfully for 14 of them). If the repetition of transmembrane regions is aperiodic, it can be revealed by another method, that is, the method of the reiterated (four to five times) averaging of the protein hydrophobicity function in a window within the limits of 9-11 amino acids that moves along the sequence. This novel method was applied to the 24 transmembrane proteins (successfully for 19 of them) and demonstrated higher suitability than the Fourier method for predicting the secondary structure of these proteins and the corresponding functional properties. © 2013 Pleiades Publishing, Ltd. Source

Ivanov P.A.,Yaroslavl State Technical University
Proceedings of SPIE - The International Society for Optical Engineering

There are presented results of scaled image recognition modeling with the help of optical correlator with invariant correlation filters like MACE, GMACE, MINACE and DCCF. The image database for testing include images of true and false classes. There are presented qualitative and quantitative characteristics of output correlation peaks. Also there is provided an analysis of positive and negative side of each filter's type as for single class only scaled images recognition so for multiclass one. Also there are shown results for modeling of images with more complex distortions recognition using all mentioned types of filters. © 2014 Copyright SPIE. Source

To investigate the influence of a strongly turbulent incoming flow on the hydrodynamic drag of a body and occurrence of the early crisis of drag, a numerical experiment is conducted in which a free gas flow about a sphere is simulated for two cases, namely, for a laminar flow and for a strongly turbulent flow. Turbulence is simulated by assuming a high kinematic coefficient of turbulent viscosity. Calculation data lead us to conclude that the early crisis of drag at Reynolds numbers near 100, which shows up as a considerable (four-to sevenfold) decrease in the hydrodynamic force and the drag coefficient of the body, can be explained by the strong turbulence of the incoming flow. © 2013 Pleiades Publishing, Ltd. Source

Discover hidden collaborations