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The dependences of the polarization parameters of probe radiation on the observation geometry and relations between the Stokes vector parameters have been simulated based on the bidirectional reflectance distribution function as applied to active polarimetric systems.

In studies [1–7] a method of adaptive artificial viscosity (AAV) was proposed for the solution of gas dynamics equations. In this paper, this method is extended to the case of triangular grids for two-dimensional (2D) equations in the variables x, y, and r, z, and of tetrahedral grids for equations in Cartesian variables x, y, and z. The calculation results for the test problems are presented.

The method of two-dimensional not equidistant antenna arrays design is based on magic squares is proposed. The properties of antenna arrays (directivity pattern, side lobe level, frequency overlap) are studied. An algorithm for providing full frequency coverage of synthesized arrays using magic squares and a method for obtaining arrays of large size using compound squares is proposed.

The possibility of creating a dictionary of signs for the radar recognition of the aerodynamic and terrestrial mechanical objects through the use of data about as dimensions of the objects, and the acoustic noise is analyzed. RCS of aerodynamic objects at resonant and short wavelengths as well as their speeds of revolution are estimated.

The possibility of using finite atomic functions of Kravchenko-Rvachev for description of the laws of distribution of the refractive index of the troposphere, the intensity of the scattering from the sea, seasonal behavior unit RCS of land areas with vegetation covering, as well as the spectrum of electromagnetic spikes of lithospheric origin is considered.

The features of optimal reception of signals propagating in media with the absorption and dispersion are considered. It is shown that in this case bandwidth of emission-reception should be adapted to the desired range of distances, as well as to compensate the phase distortion is introduced by medium of propagation. It is proposed using of the modified correlation functions for signal analysis in such cases.

An approach to the restoration of the image is distorted by turbid media is based on the use of a priori information about the form of distributions in the presence and lack of distortion is proposed. Examples of the use of the proposed approach for the restoration of the image when viewed through a turbid medium as contaminated water are shown.

The methods of determination of complex permittivity of the substance filling the resonator on changing the frequency and steepness of adjustment of generator is stabilized by them is considered. Calculated ratios and the results of their experimental check are presented.

We have developed a low-cost Ka-band radar sensor for railway applications, including the check and remote control of the track occupancy/vacancy and the car speed at hump yards and guarded and non-guarded rail crossings in an effort to reduce the risk of accident on railroads. The radar sensor is equipped with systems of remote control and internal parameter diagnostics, which provided transmission systems pass the radar and service information to the control point.

A new numerical method for the solution of gas dynamics problems for three-dimensional (3D) systems in Eulerian variables is presented in the paper. The proposed method uses the approximation O(τ2 + hx2 + hy2 + hz2) in the areas of the solution’s smoothness and beyond the compression waves; τ is the time step; and hx, hy, and hz are space variable steps. In the proposed difference scheme, in addition to Lax-Wendroff corrections, artificial viscosity μ that monotonizes the scheme is introduced. The viscosity is obtained from the conditions of the maximum principle. The results of the computation of the 3D test problem for the Euler equation are presented.

A new finite-difference method for the numerical solution of gas dynamics equations is proposed. This method is a uniform monotonous finite-difference scheme of second-order approximation on time and space outside of domains of shock and compression waves. This method is based on inputting adaptive artificial viscosity (AAV) into gas dynamics equations. In this paper, this method is analyzed for 2D geometry. The testing computations of the movement of contact discontinuities and shock waves and the breakup of discontinuities are demonstrated.

The method of adaptive artificial viscosity (AAV) [1, 2] as applied to gas dynamics problems in cylindrical, spherical, and Cartesian coordinates is considered in the paper. A new way of choosing artificial viscosity, resulting in the weak diffusion of shock waves (into three intervals), and accurate smoothing of oscillations of solutions having a grid nature is suggested. The calculation results are presented.

The method of adaptive artificial viscosity (AAV) is used for one-dimensional viscous Burger’s equations, linear and nonlinear transportation equations, and boundary layer equations. Generalization of the adaptive artificial viscosity method [1, 2] to problems with the second derivatives is shown to result in implicit difference schemes.

The paper is concerned with calculations of two-dimensional test gas dynamic problems through a new artificial viscosity grid method. A detailed account of this method is given in [1, 2]; it was extended in [3] to two and three dimensions. The equations are considered in a rectangle and in step-shaped regions using Cartesian coordinates and Euler variables, and they are closed by the gas law of ideal polytropic gas. Test problems are taken from [4–6]. A comparison of the solution of these problems as obtained by the AAV method and other methods put forward in [4–6] is made.

В статье отмечены трудности, возникающие в процессе механической обработки резанием титановых сплавов, и рассмотрены вопросы рационального выбора режущего инструмента, оснащенного сменными многогранными неперетачиваемыми пластинами (СМП) из твердого сплава, для чернового точения деталей из титанового сплава ВТ6, на основании оценки эффективности его работы и стоимости. Оценка эффективности производилась на основании показателей, определяющих их стойкость. С этой целью были проведены сравнительные стойкостные испытания СМП отечественного и зарубежного производства. Стойкостные испытания проводились в производственных условиях АО «Воткинский завод». В качестве критерия был выбран износ по задней грани за строго определенное время. По итогам проведенных испытаний было выявлено, что наименьшее изнашивание продемонстрировали СМП SNMM 250724MR 2025 фирмы Sandvik Coromant. Пластины SNMM 250724 E-NR2 Н05 фирмы Pramet примерно на 10 % изнашивались меньше их аналогов Кировоградского завода твердых сплавов SNMM 250724 Rl AP20TM и SNMM 250724 Rl TP20TM. Сравнение их по стоимости показало, что наименьшей цену имеют пластины отечественного производства, и их цена почти в три раза ниже лидера производственных испытаний. По итогам работы и исходя из соотношения цена - качества для производства были рекомендованы СМП Кировоградского завода твердых сплавов.

The induction interactions between ensembles of secondary oceanic bottom structures were studied by a 2D conductivity model. It was found that frequent intercalation of such structures lead to significant cumulative effects that had to be taken into account when modeling the structures of the first order. The study was performed for the magnetovariational sounding results obtained in the Arctic Ocean.

A method of adaptive artificial viscosity (AAV2D-3D) for the solution of two-and three-dimensional equations of gas dynamics for Euler variables in the Cartesian coordinates system is considered. This paper continues works [1, 2]. The computational scheme is described in detail and the results of the test case are given.

Parallel versions of the modified incomplete Cholesky conjugate gradient method with regularized preconditioner are proposed for solving elliptic equations on tetrahedral grids on MIMD parallel computers. The constructed parallel method use special grid point orderings correlated with domain decomposition. The convergence rates of the proposed parallel methods are examined both theoretically and numerically by analyzing a number of model problems. The comparison of the convergence rates of the proposed method and some other well-known methods is performed.

New approximations of Navier-Stokes equations are proposed for incompressible fluid on triangular and tetrahedral grids in the predictor-corrector method. Estimates are presented for the unconditional stability of difference schemes, and calculation results for a two-dimensional problem about a fluid flow in a cavity with a floating top cover; and they are compared with the solutions of other authors. The problems of grid equations monotonization are discussed.

A finite-difference method is proposed for solving gas dynamics equations, i.e., a homogeneous, monotonous finite-difference scheme of the second- order time approximation and space variables outside the areas of discontinuities and compression waves. A new way to introduce adaptive artificial viscosity (AAV) in a difference scheme is considered. The stability of the proposed difference scheme is numerically studied. Test calculations are presented for the motion of contact discontinuities, blast waves, and disintegration of discontinuities.

Presented are common and distinctive mechanisms of behavior of rotary and kinetic moments of an individual free charged particle, which particle is located in the potential well of condensed matter, depending on the type of the applied external magnetic field (MF): constant and alternating fields are orthogonal or co-linear (the combined field). It is shown, that the action of combined MF leads to energy resonance of rotary moment and to amplification of kinetic moment, whereas the action of orthogonal MF leads to magnetic resonance. The problem of appearance of additional magnetization of matter depending on the type of MF is discussed.

Interaction between the thermal fluctuation electromagnetic field of a condensed medium and a weak external factor, say, a weak effective magnetic field including an external magnetic field, rigid rotation of the medium, and Coriolis force, imparts a torque to any charged free or bound particles (atoms, molecules, etc.). which indicates that the medium is sensitive to weak actions. The torque is proportional to thermal energy kT and may increase substantially under the cyclotron resonance conditions. The so-called kT problem is solved, so that many observations having to do with the field of physics that can be called the physics of weak actions (≪kT) can now be theoretically explained.

Results are presented from studies of the spectral characteristics of a glowing plasma object that forms behind a shock wave propagating in a background gas at a pressure of 1 Torr after laser irradiation of a spherical organic target in the MKV-4 device (a component of the Iskra-5 facility). The experimental data are compared to the results of calculations.

Based on two-dimensional numerical simulations, a study was made of the radiation absorption, the energy transfer, and the plasma formation upon the interaction of a laser beam with a homogeneous medium consisting of light elements with a density not exceeding the critical plasma density, which corresponds to the plasma resonance for the wavelength of the driving laser radiation. The calculations were performed by the HEAT-3D code, which involved the solution of a two-dimensional heat conduction equation with an energy source describing the absorption of laser radiation due to inverse bremsstrahlung in the material. The simulations were performed of the interaction of laser beams of radii 10-2—6×10-2 cm, 1014—5×1015 W cm-2 in intensity, and with wavelengths of 1.053 and 0.527 μm with materials composed of light elements with densities of 1–10 mg cm-3. An analysis of the simulations showed that the spatial temperature distribution of the resultant plasma is determined by the anisotropy of energy transfer. In its turn, the degree of anisotropy depends on the relation between the beam radius and the laser radiation absorption length, which is a function of the density and the temperature of the resultant plasma. The results of simulations are compared with the findings of experiments on laser irradiation of targets composed of low-density materials.

Radiation absorption, energy transport, and plasma production due to the interaction of a laser beam with a homogeneous medium of light elements is considered on the basis of 2D numerical calculations. We assume that the density of this medium is lower than the critical density of plasma corresponding to the plasma resonance for the wavelength of the laser radiation. Calculations are performed within the framework of the HEAT-3D program which includes the equation for 2D thermal conductivity with the source of energy provided by the inverse bremsstrahlung absorption of the laser beam in the medium.

Results of updating the reducer between the LPC and the condenser involving removal of lens compensators and stiffening of the bar and rib frames are presented. Air inflows into the vacuum system through cracks in welded joints of flexible elements with total welded length of 240 m are lowered considerably by replacing them by stiff sheet structures. Computations of the thermal and stress-strain states of the system are performed.

The “metamaterials”, or artificial materials with electromagnetic properties, which can be designed by experimenter are of strong interest now for the GHz and THz band devices construction. One of promising realization of this idea is a wire media lens [1, 2] which also intended on the energy concentration. Moreover, it was demonstrated the possibility to make such a device (the wire-media lens), which allows to overcome the diffraction limit [3, 4] at frequencies of about 1 GHz. However, on the technological problems, the question of the realization of such structures (metamaterials) in the frequency range of tens, hundreds and more gigahertz is still open.

Ten patients with electrical injury (over 3000 V) of the forearm and hand were operated on during the period of 11.6±3.1 months after accident. Soft tissue plasty with free microsurgical flap and simultaneous tendon and nerve plasty with nonvascularized autograft was performed in eight patients. In two patients with extensive soft tissue defects microsurgical flap included musculus latissimus dorsi that was reinnervated using the anastomoses with anterior interosseous nerve. For the restoration of sensation along the palmar surface of the hand, transposition of ulnar nerve segment on a vascular pedicle from the arm to the forearm was performed. Although no severe postoperative complications developed all patients required tendolysis and transposition of tendons for the restoration of tendon function. Those additional interventions provided the restoration of the wrist grip and social rehabilitation of all patients.

Two-dimensional numerical calculations were made in a study of heat-conduction and hydrodynamic equalisation of the asymmetry of heating and compression of `laser greenhouse` targets. It is shown that small-scale perturbations become equalised by the high thermal conductivity and by transverse shock waves in the absorber component of a target. It is proposed to use working targets with a surface relief for compensating the strong heating asymmetry associated with coupling of laser radiation through apertures in an outer chamber. 9 refs., 8 figs.

The Ka-band radar autodyne sensors are suggested for railway applications, including the check and remote control of the track occupancy/vacancy and the car speed at hump yards and as part of an obstacle detection unit for monitoring the rail tracks and the block unit lids on guarded and non-guarded rail crossings in an effort to reduce the risk of accident on railroads. © 2012 IEEE.

This report presents the results of a theoretical study and 2D numerical simulations of the interaction of subnanosecond iodine laser pulses with an Al-foil target. The target and laser parameters correspond to the experimental conditions of the “PERUN” iodine laser facility (IP, Prague: pulse energy

The dynamics of an infinite chain of like particles linked both to each other and to a certain immobile base (a chain of bound oscillators) is considered. The chain of oscillators occurs in a variable and spatially inhomogeneous thermal electromagnetic field inducing significant fluctuations in the shape of potential of the interparticle interaction. It is shown that the field action renders the bound oscillators a parametric system pumped by the thermal field. An increase in the temperature (accompanied by an increase in the spectral density and frequency range of the thermal field) leads to an increase in the relaxation time of oscillators and eventually to their self-excitation. A condition of the corresponding first-order phase transition is obtained.

Efficiency of narrow-band Doppler selections has been considered. Characteristics of detectors with adaptation of a threshold and rank at various polarizations of radiation and reception are estimated.