Izhevsk, Russia
Izhevsk, Russia

Udmurt State University is a public university in the city of Izhevsk, Russia. Established in 1931, UdSU is the oldest educational institution in Udmurt Republic. In 1993, it was named among top twenty classical Russian universities, since then consistently ranks 14-16 out of 64 Russian universities.As of 2006 over 28,000 students are enrolled at the Udmurt State University, which offers 86 different majors. About 9,200 of them are full-time undergraduates. Wikipedia.

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Bizyaev I.A.,Udmurt State University | Tsiganov A.V.,Saint Petersburg State University
Journal of Physics A: Mathematical and Theoretical | Year: 2013

We discuss an embedding of a vector field for the nonholonomic Routh sphere into a subgroup of commuting Hamiltonian vector fields on six-dimensional phase space. The corresponding Poisson brackets are reduced to the canonical Poisson brackets on the Lie algebra e*(3). It allows us to relate the nonholonomic Routh system with the Hamiltonian system on a cotangent bundle to the sphere with a canonical Poisson structure. © 2013 IOP Publishing Ltd.

Murina V.,Russian Academy of Sciences | Lekontseva N.,Udmurt State University | Nikulin A.,Russian Academy of Sciences
Acta Crystallographica Section D: Biological Crystallography | Year: 2013

The Hfq protein forms a doughnut-shaped homohexamer that possesses RNA-binding activity. There are two distinct RNA-binding surfaces located on the proximal and the distal sides of the hexamer. The proximal side is involved in the binding of mRNA and small noncoding RNAs (sRNAs), while the distal side has an affinity for A-rich RNA sequences. In this work, the ability of various ribonucleotides to form complexes with Hfq from Pseudomonas aeruginosa has been tested using X-ray crystallography. ATP and ADPNP have been located in the distal R-site, which is a site for poly(A) RNA binding. UTP has been found in the so-called lateral RNA-binding site at the proximal surface. CTP has been found in both the distal R-site and the proximal U-binding site. GTP did not form a complex with Hfq under the conditions tested. The results have demonstrated the power of the crystallographic method for locating ribonucleotides and predicting single-stranded RNA-binding sites on the protein surface. © 2013 International Union of Crystallography.

Bizyaev I.A.,Udmurt State University | Borisov A.V.,National Research Nuclear University MEPhI | Mamaev I.S.,Udmurt State University
Celestial Mechanics and Dynamical Astronomy | Year: 2015

This paper is concerned with the figures of equilibrium of a self-gravitating ideal fluid with a stratified density and a steady-state velocity field. As in the classical formulation of the problem, it is assumed that the figures, or their layers, uniformly rotate about an axis fixed in space. It is shown that the ellipsoid of revolution (spheroid) with confocal stratification, in which each layer rotates with a constant angular velocity, is at equilibrium. Expressions are obtained for the gravitational potential, change in the angular velocity and pressure, and the conclusion is drawn that the angular velocity on the outer surface is the same as that of the corresponding Maclaurin spheroid. We note that the solution found generalizes a previously known solution for piecewise constant density distribution. For comparison, we also present a solution, due to Chaplygin, for a homothetic density stratification. We conclude by considering a homogeneous spheroid in the space of constant positive curvature. We show that in this case the spheroid cannot rotate as a rigid body, since the angular velocity distribution of fluid particles depends on the distance to the symmetry axis. © 2015, Springer Science+Business Media Dordrecht.

Zaitsev V.A.,Udmurt State University
Systems and Control Letters | Year: 2016

We consider a nonlinear control system with periodic coefficients. We study the problem of asymptotic stabilization of the equilibrium x=0 of the closed-loop system by state feedback. We assume that the free dynamic system possesses a periodic Lyapunov function ensuring Lyapunov stability of the equilibrium x=0. We have developed a method for constructing a damping control for affine systems with periodic coefficients based on a generalization of weak Jurdjevic-Quinn conditions, using an extension of the notion of the commutator to non-stationary vector fields. Using this approach, we obtain sufficient conditions for uniform local and global asymptotic stabilization of general nonlinear systems, in particular, affine control systems, with periodic coefficients. Stabilization results generalize known results for time-invariant systems to time-varying periodic systems. © 2016 Elsevier B.V. All rights reserved.

Kharanzhevskiy E.V.,Udmurt State University
Physics of Metals and Metallography | Year: 2016

The structure of compacted specimens produced using the rapid laser melting of ultradispersed Fe–50 wt % Cu powders has been studied. The original powder was produced via the mechanical milling of iron and copper powders in a planetary-type ball mill. It has been found that the structure of the compacted specimens produced using rapid laser melting exhibits signs of the initial stages of separation in supercooled liquid. It has been shown using X-ray diffraction analysis as well as scanning and transmission electron microscopy that the final structure contains a supersaturated (Fe; Cu) solid solution formed from the high-speed movement of the solidification front and the nonequilibrium capture of copper by the moving front. © 2016, Pleiades Publishing, Ltd.

Zaitsev V.,Udmurt State University
Proceedings of 2016 International Conference "Stability and Oscillations of Nonlinear Control Systems" (Pyatnitskiy's Conference), STAB 2016 | Year: 2016

We obtain sufficient conditions for uniform exponential stabilization (with a given exponent) of the zero unperturbed solution to a control system defined by a quasi-linear n-order differential equation by means of static output feedback. © 2016 IEEE.

Kuznetsov S.P.,Udmurt State University
Physics-Uspekhi | Year: 2015

In connection with the problem of a convex-shaped solid body on a rough horizontal plane (the rattleback or Celtic stone), the paper discusses the validity of the nonholonomic model which postulates that the contact point has zero velocity and, hence, friction performs no mechanical work. While abstract, this model is undoubtedly constructive, similar to many idealizations commonly used in science. Despite its energy-conserving nature, the model does not obey Liouville's theorem on phase volume conservation, thus allowing the occurrence in the phase space of objects characteristic of dissipative dynamics (attractors) and thereby leading to phenomena like the spontaneous reversal of rotations. Nonholonomic models, intermediate between conservative and dissipative systems, should take their deserved place in the general picture of the modern theory of dynamical systems. © 2015 Uspekhi Fizicheskikh Nauk, Russian Academy of Sciences.

Chausov F.F.,Udmurt State University
Bulletin of the Russian Academy of Sciences: Physics | Year: 2013

A method for protecting steel against oxygen corrosion in water solutions using an inhibitor that selectively reacts with a metal surface in corrosion centers is proposed. 1-hydroxyethylidenediphosphonatozincate, which contains a localized π bond between its phosphorus and oxygen atoms, is used as the inhibitor in combination with magnesium ions at an oxygen concentration of 0.1 to 6.0 mg dm-3 and pH in a water solution of 5.8 to 11.1. A 91-93% degree of protection is achieved at an inhibitor concentration of 6 mg dm -3. © 2013 Allerton Press, Inc.

Kondratyev B.P.,Udmurt State University
Solar System Research | Year: 2011

A flexible and informative vector approach to the problem of physical libration of the rigid Moon has been developed in which three Euler differential equations are supplemented by 12 kinematic ones. A linearized system of equations can be split into an even and odd systems with respect to the reflection in the plane of the lunar equator, and rotational oscillations of the Moon are presented by superposition of librations in longitude and latitude. The former is described by three equations and consists of unrestricted oscillations with a period of T1 = 2.878 Julian years (amplitude of 1.855″) and forced oscillations with periods of T2 = 27.201 days (15.304″), one stellar year (0.008″), half a year (0.115″), and the third of a year (0.0003″) (five harmonics altogether). A zero frequency solution has also been obtained. The effect of the Sun on these oscillations is two orders of magnitude less than that of the Earth. The libration in latitude is presented by five equations and, at pertrubations from the Earth, is described by two harmonics of unrestricted oscillations (T5 ≈ 74.180 Julian years, T6 ≈ 27.347 days) and one harmonic of forced oscillations (T3 = 27.212 days). The motion of the true pole is presented by the same harmonics, with the maximum deviation from the Cassini pole being 45.3″. The fifth (zero) frequency yields a stationary solution with a conic precession of the rotation axis (previously unknown). The third Cassini law has been proved. The amplitudes of unrestricted oscillations have been determined from comparison with observations. For the ratio sinI/sin(I+i) ≈ 0.2311 the theory gives 0.2319, which confirms the adequacy of the approach. Some statements of the previous theory are revised. Poinsot's method is shown to be irrelevant in describing librations of the Moon. The Moon does not have free (Euler) oscillations; it has oscillations with a period of T5 ≈ 74.180 Julian years rather than T ≈ 148.167 Julian years. © 2011 Pleiades Publishing, Ltd.

Petrov N.N.,Udmurt State University
Automation and Remote Control | Year: 2014

We consider two linear nonstationary pursuit-evasion problems with one evader and a group of pursuers under the conditions that the players have equal dynamic abilities and that the evader cannot leave a certain set. We prove that if the number of pursuers is less than the space dimension, then the evader can avoid capture in the interval [t 0,∞). © 2014 Pleiades Publishing, Ltd.

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