Generation and propagation of polarization singularities in second harmonic generation from the surface of the isotropic gyrotropic medium

When proceeding to the oblique incidence from thenormal incidence geometry in surface secondharmonic generation, the symmetry of the problemand, thus, of the reflected signal beam breaks. Inthis case there can appear C-points in thetransversal section of the signal beam. Using theanalytical formulae obtained in previous works, westudied the conditions of appearance and thebehaviour of the C-points in reflected signal beam(in particular case of SHG), and also the way of theline-to-point singularity transformation

Effect of Preparation Conditions in the Pressure Range of Atmospheric Nitrogen (2 ... 50) 10-4 Torr on the Structural and Phase State of the Vacuum-Arc Coatings of Mo-N

Nanocrystalline vacuum-arc nitride coatings possess the totality of unique structural states and properties (high hardness, wear resistance, oxidation stability, etc.). The coatings of the Mo-N system show a high hardness and low solubility of nonferromagnetic materials, thereby attracting great interest in their industrial use. Unfortunately, at present there is an apparent lack of information on the regularities of phase-structural state formation in the Mo-N system. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3535

Semiclassical Study of Baryon and Lepton Number Violation in High-Energy Electroweak Collisions

We make use of a semiclassical method for calculating the suppression exponent for topology changing transitions in high-energy electroweak collisions. In the Standard Model these processes are accompanied by violation of baryon and lepton number. By using a suitable computational technique we obtain results for s-wave scattering in a large region of initial data. Our results show that baryon and lepton number violation remains exponentially suppressed up to very high energies of at least 30 sphaleron masses (250 TeV). We also conclude that the known analytic approaches inferred from low energy expansion provide reasonably good approximations up to the sphaleron energy (8 TeV) only.Comment: 23 pages, 18 figures. Phys.Rev.D journal version (two references added

Ferromagnetic properties of charged vector boson condensate

Bose-Einstein condensation of W bosons in the early universe is studied. It is shown that, in the broken phase of the standard electroweak theory, condensed W bosons form a ferromagnetic state with aligned spins. In this case the primeval plasma may be spontaneously magnetized inside macroscopically large domains and form magnetic fields which may be seeds for the observed today galactic and intergalactic fields. However, in a modified theory, e.g. in a theory without quartic self interactions of gauge bosons or for a smaller value of the weak mixing angle, antiferromagnetic condensation is possible. In the latter case W bosons form scalar condensate with macroscopically large electric charge density i.e. with a large average value of the bilinear product of W-vector fields but with microscopically small average value of the field itself.Comment: Some numerical estimates and discussions are added according to the referee's suggestions. This version is accepted for publication in JCA

ACCOUNTING THE DEGREE ОF IMPROVEMENT MASS OF GTE WITH FREE TURBINE FOR HELICOPTERS

Refinement in the mass model of a helicopter GTE coefficient characterizing the improvement of engine mass by the introduction of design and technological activities, which, in many respects, depends on the year of the start of the mass production of the projected GTE

ACTUALIZATION OF THE MASS MODEL GTE WITH FREE TURBINE FOR HELICOPTERS

When performing parametric research of gas turbine engines with a free turbine, it is important to use such models that correctly reflect the influence of the parameters of the working process on the nature of the change in the specific fuel consumption and engine mass. As new GTE variants appear, it is required to periodically update the values of the coefficients, which was done in the paper

ACCOUNTING THE INFLUENCE ОF GAS TEMPERATURE IN THE MODEL OF MASSES GTE WITH FREE TURBINE FOR HELICOPTERS

The achievement of the best performance of aircraft engines in terms of economy is realized to a large extent due to the development of ever higher gas temperatures at the entrance to the turbine. There are two ways to solve this problem - the organization of systems for intensive cooling of turbine elements, and the use of new technologies and materials capable of ensuring reliable operation of all GTE elements. The article describes the nature of the effect of various elements to the cooling system of the engine masses

Wick type deformation quantization of Fedosov manifolds

A coordinate-free definition for Wick-type symbols is given for symplectic manifolds by means of the Fedosov procedure. The main ingredient of this approach is a bilinear symmetric form defined on the complexified tangent bundle of the symplectic manifold and subject to some set of algebraic and differential conditions. It is precisely the structure which describes a deviation of the Wick-type star-product from the Weyl one in the first order in the deformation parameter. The geometry of the symplectic manifolds equipped by such a bilinear form is explored and a certain analogue of the Newlander-Nirenberg theorem is presented. The 2-form is explicitly identified which cohomological class coincides with the Fedosov class of the Wick-type star-product. For the particular case of K\"ahler manifold this class is shown to be proportional to the Chern class of a complex manifold. We also show that the symbol construction admits canonical superextension, which can be thought of as the Wick-type deformation of the exterior algebra of differential forms on the base (even) manifold. Possible applications of the deformed superalgebra to the noncommutative field theory and strings are discussed.Comment: 20 pages, no figure

Chern-Simons production during preheating in hybrid inflation models

We study the onset of symmetry breaking after hybrid inflation in a model having the field content of the SU(2) gauge-scalar sector of the standard model, coupled to a singlet inflaton. This process is studied in (3+1)-dimensions in a fully non-perturbative way with the help of lattice techniques within the classical approximation. We focus on the role played by gauge fields and, in particular, on the generation of Chern-Simons number. Our results are shown to be insensitive to the various cut-offs introduced in our numerical approach. The spectra preserves a large hierarchy between long and short-wavelength modes during the whole period of symmetry breaking and Chern-Simons generation, confirming that the dynamics is driven by the low momentum sector of the theory. We establish that the Chern-Simons production mechanism is associated with local sphaleron-like structures. The corresponding sphaleron rates are of order 10^{-5} m^4, which, within certain scenarios of electroweak baryogenesis and a (not unnaturally large) additional source of CP violation, could explain the present baryon asymmetry of the universe.Comment: 28 pages, 15 figures, ReVTeX. With minor corrections, version to appear in Phys. Rev.

PEDAGOGIC SCHOOL OF THEORY OF WORKFLOW AND TESTING OF GAS TURBINE ENGINES OF SAMARA UNIVERSITY

Brief history ofpedagogic school of Theory of workflow and testing of gas turbine engines of Samara University is provided. The features and benefits of the courses of Theory of gas turbine engines, Theory and calculation of blade machines. Workflow theory of combustion chambers and Testing aircraft engines are considered