Methods to improve immunity noise detection and direction finding using a vector-scalar modules
Methods to improve immunity noise detection and direction finding using a vector-scalar modules
G. N. Kuznetsov$^1$, A. F. Kurchanov$^2$
Made direction finding of broadband sources of scalar antenna (SA) and vector-scalar modules (VSM) using processing the flow of power and the new method based on the use of pseudovectors built on the projection of vector vibrational rate (VVV). Investigated method of interference suppression from a local source with using of vector fields.
Show AbstractResearch unidirectional reception, evaluation range and source depth using scalar and vector-scalar antennas
Research unidirectional reception, evaluation range and source depth using scalar and vector-scalar antennas
G. M. Glebova$^1$, G. N. Kuznetsov$^2$
We analyze the spatial spectra at the output of the linear scalar or vector-scalar antenna (SA or VSA) at signal processing methods having a different resolution, consistent or inconsistent with the transfer function of the waveguide. The experiments were conducted in a shallow pool at the stationary location of the antenna and the emitter and in regime of the towing with the moving noise source. VSA, unlike SA, suppresses signals coming on «mirror» petals and has unidirectional direction finding, and at using consistent processing in passive mode uniquely determines the distance and the depth of the source.
Show AbstractTheoretical analysis of a torque exerted by the vortex ultrasonic beam on the absorber located in liquid
Theoretical analysis of a torque exerted by the vortex ultrasonic beam on the absorber located in liquid
M. E. Terzi, S. A. Tsysar, P. V. Yuldashev, O. A. Sapozhnikov
Waves of any nature carry energy and momentum. In certain configurations of wave beams, angular momentum transfer is also possible: the corresponding beams are called “vortex beams”. In this paper, we study the ability of a vortex acoustic beam of the megahertz range to rotate a large-sized absorber (of several dozen wavelengths in diameter) in a liquid. The vortex beam was formed in water by passing ultrasonic radiation from a focusing piezoceramic source through a non-uniform in thickness 12-sector phase plate made from Plexiglas. The beam propagated vertically upward and was directed to an acoustic absorber in the form of a cylinder 10 cm in diameter and 3 cm in height made of silicone rubber. The absorber was freely suspended on a thin elastic thread. It is demonstrated that when the absorber is irradiated, it is rotated. By scanning the acoustic field in the transverse plane by a miniature hydrophone, two-dimensional distributions of the amplitude and phase of the wave were found, and on the basis of these calculations the moment of the radiation beam force applied to the absorber was calculated. The results of the calculations are in agreement with the observations.
Show AbstractUltrasonic gas flowmeters with laid-on sensors
Ultrasonic gas flowmeters with laid-on sensors
A. D. Mansfeld$^1$, A. G. Sanin$^1$, G. P. Volkov$^1$, R. V. Beliaev$^1$, D. V. Moroskin$^2$
Two types of ultrasonic flowmeters with laid-on sensors have been described realizing gas flow measurement through metal pipe wall. The main advantage of developed flowmeters is an ability to measure gas flow without sensor insertion into the wall even at low pressure. Different probing methods (pulse, continuous), "wall" signals influence, useful signal selection methods have been considered. Laboratory and field experimental results are presented.
Show Abstract3D-printing possibilities for the manufacturing technology development of hydroacoustic longitudinal bending type emitters with the complex radiator's body geometry
3D-printing possibilities for the manufacturing technology development of hydroacoustic longitudinal bending type emitters with the complex radiator's body geometry
A. K. Britenkov$^{1,2}$, B. N. Bogolybov$^1$, S. A. Smirnov$^1$, V. A. Perfilov$^1$
Low-frequency hydroacoustic emitters are being used in a wide range of tasks: from long-distance sound communication and remote control to seismoacoustic reconnaissance. Thus the manufacturing of compact high-power radiators emitting in a sufficiently wide frequency band is an actual task. Making the radiator shell is one of the most laborious and complicated technological operations in the process of creating and customizing hydroacoustic transducers. Unrealizable for the ordinary metalworking complex shapes of radiator's body can be produced by layering laser melting (SLM-technology). Making the radiator shell longitudinal bending-type piezoelectric active element by laser 3D-printing of metal powders eliminates the problem of encapsulation, resistance to hydrostatic pressure and reduce the parameters dispersion of the radiator to facilitate its configuration, as well as improve reliability of the transducer.
Show AbstractInfluence of the reactive atmosphere during magnetron sputtering on evolution of the phase composition of diamond-like coatings doped with chromium
Influence of the reactive atmosphere during magnetron sputtering on evolution of the phase composition of diamond-like coatings doped with chromium
I. S. Levin$^{1,2}$, V. M. Avdyukhina$^1$, M. M. Khrushchov$^2$, V. A. Schergunov$^2$
In the work, samples of diamond-like carbon coatings doped with chromium, obtained with the help of magnetron sputtering technology in active gas media, were investigated. The influence of the features of coating deposition (first of all, the composition of the sputtering atmosphere) on their phase composition and the fine atomic structure was studied. X-ray diffractometry was used as the main research method.
Show AbstractMethods of accelerated convergence in statistical physics
Methods of accelerated convergence in statistical physics
P. N. Nikolaev
In the work the classification of the methods of accelerated convergence used in statistical physics is given. Among them a combined method using physical analysis of the system and mathematical methods of accelerated convergence is picked out. Its effectiveness is shown for obtaining the Carnahan-Starling equation. The proposed method is of a general nature and is applicable to a wide class of systems.
Show AbstractModern physics in the course "History and methodology of physics"
Modern physics in the course "History and methodology of physics"
P. N. Nikolaev
The principles of the construction the exposition of the modern physics in the course "History and methodology of physics" is investigated. The causal link between the state of modern physics and the content of the course "History and the methodology of physics" has been noted.
Show AbstractAnalysis of information search capabilities in physics: the problem of internet searching on the example of acoustics
Analysis of information search capabilities in physics: the problem of internet searching on the example of acoustics
V. G. Shamaev$^1$, A. B. Gorshkov$^2$, L. G. Guschina$^3$, V. I. Yakimenko$^4$
Problems of online access to scientific information are discussed. Brief information on foreign information retrieval systems is given. The state of information support for Russian-language sources in the USSR and now is described. The absence of a single center for collecting and providing information on Russian-language scientific publications is noted. A scheme is proposed for use in the creation of such a center. A possible cluster of this center is described on the example of acoustic topics, already implemented at the Acoustics Department of the Physics Department of the M.V. Lomonosov Moscow State University. The corresponding portal «Acoustics» (http://akdata.ru) is in the public domain on the Internet. Entrance points of the portal: full-text archive of «Acoustic Journal», «Signaling information» on acoustics and «Information retrieval system. Acoustics. Russian-language sources». Brief description of the work with the system is provided. The developed technologies for the preparation of information resources and the resources themselves constitute a complete system of information support for acoustic research in the Russian-speaking segment. They also make it possible to provide a full reflection of the Russian-language scientific literature for monitoring and expert evaluation of the scientific activities of Russian scientists, which can contribute to strengthening the positive image of Russian sci-ence in the world. Questions of priority and preservation of intellectual property are being raised. It is concluded that only properly organized information support can guarantee the pu-rity and novelty of the scientific results that underlie the research process.
Show AbstractMathematical model of periodic waveguide systems with rectangular cross-section
Mathematical model of periodic waveguide systems with rectangular cross-section
M. I. Svetkin, A. N. Bogolubov, A. I. Erokhin, V. M. Pikunov
A mathematical model of an ideally conducting periodic waveguide system with piecewise constant rectangular cross-section is proposed. This type of geometry is finding application in the development of terahertz devices more often recently. The problem to solve is a system of Maxwell equations supplemented by metal boundary conditions and Floquet conditions on cross-sections spaced by one period of the structure. The solution of the problem is based on incomplete Galerkin's method and projection field conjunction in the region of cross-sections jumps. Direct use of this approach leads to matrix problems with ill-conditioned matrices due to simultaneous presence of exponentially increasing and decreasing matrix coefficients. In this context the method to be proposed additionally takes into account the directions of wave propagation in any regular section in the system, which makes it possible to eliminate exponentially increasing elements and make the matrices well-conditioned. Internal wave reflections occurring within the considering period of the system are taken into account explicitly. Based on the proposed model the dispersion characteristics of various structures are constructed. The convergence of the method to the limiting cases is investigated.
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