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ASA and IIAV scholars 2004
ASA scholars
 
  1. Alexei Batrin
    Photo of Alexei Batrin
    Place of work: Taganrog State University of Radio Engineering.
    Date of birth: 01.31.1979
    Research title: Phase dependence of nonlinear wave processes in quadratically-nonlinear non-dispersion media.
    Main results:
    The role of amplitude, phase and frequency relationships is considered at nonlinear interaction of two acoustic waves with multiple frequencies in the quadratically-nonlinear medium without dispersion. The solution of Riemannian equation for a biharmonic wave of end amplitude with multiple frequencies in forebreak areas is received. Within the framework of this solution decrease in influence of phase relationships is shown at increase in the relation of frequencies as on process of formation of break in a time structure, and on behaviour of initial and secondary waves. By the example of interaction of waves with frequencies with a ratio 1:3 it is shown, that selection of amplitude-phase relationships it is possible to achieve various practically significant effects. For example, an interdiction of generation of the second harmonic, weakening or amplification of nonlinear attenuation of the first harmonic, etc. The experimental researches which have been carried out in fresh water, confirm theoretically received laws.
    Main publications:
    1. Gavrilov A.M., Batrin A.K. Nonlinear interaction of waves with multiple frequencies and undefined amplitude-phase relationship. Proceedings of the 15-th session of the Russian acoustical society, GEOS, 2004, vol.1, p. 16-20.
  2. Alexandr Dymov
    Photo of Alexandr Dymov
    Place of work: Moscow State University.
    Date of birth: 06.07.1979
    Research title: Spontaneous activity and internal periodic oscillations in neurons of the auditory system.
    Main results:
    We recorded extracellularly the spontaneous activity in the medullar and midbrain auditory units of the frog (Rana t. temporaria). The variability of the statistical characteristics of the spontaneous activity in the midbrain (torus semicircularis) units increased considerably in comparison to the medullar (cochlear nucleus) units. In particular, in the midbrain some midbrain units demonstrated peaked, multi-peaked and peak-notch-peak hazard and autocorrelation functions. The complex forms of these functions have been also observed in several medullar acoustically droved units those were located outside of the region of the secondary-order auditory cells.
    In the majority of the units of both auditory nuclei the discharge pattern of spontaneous activity for comparatively short (less then 0.5 sec) intervals could be simulated by a point renewal process. Fano factor analysis was used to characterize the process. Values of the variance of the number of recorded spikes divided by the mean number of spikes were calculated for window sizes of systematically varied length. For short time windows the Fano factor was close to one. In some (very rare) cases this factor dipped below one at some intermediate sizes of the time window. This effect could be determined by a quasi-periodicity of the spontaneous firing, determined usually (in monomodal auditory units) by a long refractoriness period. For a wide range of longer window sizes the Fano factor curves took a form of power law function. The power law relationship in the Fano factor curves have been partly or completely eliminated by randomly shuffling the interspike intervals. The presence of long-term correlation across different time scales reflects the property of statistical self-similarity that is characteristic of fractal process.
    Main publications:
    1. Bibikov N.G., Dymov A.B., Panyutin A.D., Patin K.I., Iordanskaya S.K. The program for 3D presentations of neuronal structures of separate nuclei of the brain. Computer and mathematic modeling in natural and technical sciences. 2002, v.18, p.16.
    2. Bibikov N.G., Dymov A.B. Search of internal periodic oscillations in neurons of the auditory system. Proceedings of 13 Sessions of Russian Acoustical Society. Moscow, G┼╬S, 2003, v.3, pp. 239-243.
    3. Bibikov N.G., Nizamov S.V., Dymov A.B. Analysis of spontaneous and evoked activity of neurons located in auditory centers of medulla and midbrain of the frog //in Proceedings of the 3th conference "Physiology of hearing and speech" devoted to G.V. Gershuni. St-Petersburg, 2003, pp.13-14.
    4. Dymov A.B. The some features spontaneous activity statistics of the neurons. Abstracts of the III Congress of biophysicists of Russia. Voronezh, 2004, v.1, pp. 340-341.
  3. Marina Glavatskikh
    Photo of Marina Glavatskikh
    Place of work: Physical Technical Institute, Ural Division, RAS.
    Date of birth: 03.08.1969
    Research title: Electromagnetic excitation of ultrasound.
    Main results:
    Research was dedicated to the study of the elastic and magnetoelastic properties of ferromagnetic metals and their alloys by the method of excitation of ultrasound by an external electromagnetic field. Materials with high magnetostriction value, like Fe, Ni, Co and alloys based on these metals, were used as the subject of study. The experiments have shown the possibility to apply this method to the study of amorphous materials. The type of the excited wave (longitudinal, shear, surface etc.) depends on the construction of the transducer (inductive coil) and on the directions of the action of the constant polarizing magnetic field and the variable magnetic field of the transducer on the sample. The measured parameters provide information about the velocity of the wave, the internal friction, the dynamic magnetostriction. The method makes it possibile to excite the ultrasound at both the frequency of the electromagnetic field and the higher harmonics. It was noticed that the ultrasound generation increases in the vicinity of the magnetic phase transitions connected with the change of the type of magnetic ordering or the disappearance of the magnetic order, as well as in the region of structural transformation. For example, a sharp rise of the amplitude of ultrasonic oscillations was observed near the temperature of the "ferromagnet-paramagnet" transition in Fe-Ni-Co alloys and the amorphous Fe(81%)-B(13.5%)-Si(3.5)-C(2%) alloy, and in the vicinity of the spin reorientation (the change of the spontaneous magnetization direction) in cobalt. Analysis of the temperature and field dependences of the amplitude of ultrasound generation allows one to estimate the magnetic phase boundaries and to construct the H-T diagram.
    Main publications:
    1. Il'yasov R.S., Glavatskikh M.Yu. Electomagnetic-Acoustic Conversion in the Vicinity of Spin Reorientation Transition in Cobalt. The Physics of Metals and Metallography, Vol.84, No.2, 1997, pp.149-152.
    2. Il'yasov R.S., Glavatskikh M.Yu. Electromagnetic Generation of the Second Ultrasonic Harmonics in the Vicinity of Spin Reorientation Transition in Cobalt. The Physics of Metals and Metallography, Vol.88, No.2, 1999, pp.170-173.
    3. Glavatskikh M.Yu., Il'yasov R.S. Electromagnetic Generation of Ultrasound in Cobalt. The Physics of Metals and Metallography, Vol.92, Suppl.1, 2001, S.147-149.
    4. Glavatskikh M.Yu., Il'yasov R.S. Electromagnetic-Acoustic Transformation in the Amorphous Materials. Proceeding of the XI Session of the Russian Acoustical Society, V.2. - Moscow: GEOS, 2001, pp.168-172.
    5. Il'yasov R.S., Glavatskikh M.Yu. Electomagnetic-Acoustic Transformation in the Amorphous Fe81B13.5Si3.5C2 Alloy. The Physics of Metals and Metallography, Vol.95, No.3, 2003, pp.237-241.
  4. Stanislav Il'ine
    Photo of Stanislav Il'ine
    Place of work: Moscow Institute of Electronic Technology.
    Date of birth: 29.05.1978
    Research title: Segmentation of ultrasonic images using learning vector quantization network.
    Main results:
    In this study, a novel method for biomedical image segmentation that provides an effective classification of similar pixel groups and their following extraction into separate regions was proposed and analyzed. Original image pixels intensities were used as a source of input data. The classification was carried out by means of a learning vector quantization network, which was employed to obtain the extraction of main classes (structures, tissues, artifacts etc.) presented in the image. A series of experiments was conducted to estimate the influence of network parameters (such as quantity of neurons in network layers, initial weights of the network) on accuracy and speed of image segmentation. It was determined, that increment of Kohonen layer neurons makes sense only until defined quantity of neurons, after that segmentation accuracy remains sensibly constant, but computational time increases. Analyses of image preprocessing as a mean to accuracy improvement were made; in particular, Gaussian blurring of the image allows to remove a part of presented noise term.
    Main publications:
    1. 1. S. V. Il'in, M. N. Rychagov Segmentation of Acoustic Images by Neural Network Processing, Acoustical Physics, Vol. 50, No. 5, pp. 528-534, 2004.
  5. Victor Inkov
    Place of work: Moscow State Mining University.
    Date of birth: 11.06.1980
    Research title: The development of laser ultrasonic method for testing of rocks structure and properties.
    Main results:
    For nondestructive rocks structure and properties testing the problem of generation ultrasonic signals with frequency band from 300kHz to 50 MHz and pressure amplitude up to 10 MPa is appeared. The optoacoustical method of excitation ultrasonic pulses is quite promising for decision of this problem. The work was devoted to the research of the effect of thermophysical rock's properties on generated acoustical signals parameters. Theoretical model of powerful wideband sound excitation was suggested. The ability of the effect of thermal nonlinearty application for laser ultrasonic testing rocks was proved. The structure circuit of geological materials monitoring based on kinematic and dynamic properties measurements of elastic waves, which were excited by Q-switch solid laser, was developed.
    Main publications:
    1. In'kov V.N., Karabutov A.A., Pelivanov I.M. A theoretical model of the linear thermo-optical response of an absorbing particle immersed in a liquid //Laser Physics, 2001, 11(12), pp.1283-1291.
    2. V.N. In'kov, A.A. Karabutov and I.M. Pelivanov Optoacoustic response from absorbed particle in liquid// Nonlinear Acoustics at the Beginning of the 21st Century, edited by O.V. Rudenko and O.A. Sapozhnikov (Faculty of Physics, MSU, Moscow 2002), vol.2, pp.901-904.
  6. Khokhlova Tatiana
    Photo of Khokhlova Tatiana
    Place of work: Lomonosov Moscow State University.
    Date of birth: 06.12.1982
    Research title: Focused array transducer for optoacoustic tomography.
    Main results:
    A new design of an array transducer for optoacoustic imaging was proposed. The array consisted of 32 wideband hydrophones, each one of them was focused. Transient response of a single focused piezo-detector has been studied both theoretically and experimentally. A new simplified approach has been applied for the transient response calculation. The results of the calculations were in a good agreement with experimental data that validates the proposed approach. The minimal in-depth resolution was estimated according to transient response studies, which yielded 0.5 mm. Low-frequency sensitivity of a single detector was measured and yielded 8 mV/Pa. For determination of the resolution in direction perpendicular to the imaging plane the focal zone maps for detectors with various aperture angles were plotted using experimentally obtained integrated OA signals. According to these studies, minimal value of resolution in this direction equals to 2 mm for the detector with aperture angle. These values are in a good agreement with the results of numerical modeling. Monte-Carlo modeling was applied to investigation of light propagation in turbid medium containing an absorbing heterogeneities with optical properties typical for human breast and cancerous tumor. It was shown that the laser wavelength 1064 nm is not optimal for use in optoacoustic diagnostics of breast cancer on early stages as maximum diagnostic depth was only 3.5 cm. The use of 800 nm wavelength allowed to increase the diagnostic depth to 6 cm. OA response from the turbid medium under different irradiation conditions was calculated and according to these studies optimal geometry of tissue irradiation was determined. The contrast of OA images of absorbing heterogeneity embedded into a turbid medium was calculated. It was shown that the contrast of OA images depends on the depth of tumor (absorbing heterogeneity) location. The contrast of the OA image of absorbing object embedded at depth 6 cm within turbid medium was 0.65 under irradiation by laser light with the wavelength 800 nm.
    Main publications:
    1. A.N.Zharinov, A.A.Karabutov, V.V.Kozhushko, I.M.Pelivanov, V.S.Solomatin, and T.D.Khokhlova, Wideband Focused Film Transducer for Optoacoustic Tomography,// Acoustical Physics, Vol.49, No.6, pp.682-688, 2003.
    2. Vladimir A.Makarov, Ivan M.Pelivanov, Victor V.Kozhushko, Tat'yana D.Khokhlova, Alexei N.Zharinov, Alexander A.Karabutov. "Focused Array Transducer for 2D Optoacoustic Tomography", // Proc. SPIE edited by A.A. Oraevsky, Vol. 4960, pp. 156-167, 2003.
    3. A.N. Zharinov, A.A. Karabutov, V.V. Kozhushko, I.M. Pelivanov, V.S. Solomatin, T.D. Khokhlova "Spatial Resolution of the Focused Array Transducer for Optoacoustic Tomography" Laser Physics, number 1, vol.14, pp 106-113, 2004.
    4. Victor Kozhushko, Tanya Khokhlova, Alexei Zharinov, Ivan Pelivanov, Vladimir Solomatin, Alexander Karabutov "Focused array transducer for 2D optoacoustic tomography", Journal of Acoustical Society of America, 116(3), pp. 1498-1506, September 2004.
  7. Elena Kim
    Photo of Elena Kim
    Place of work: Physics Department, Moscow State University.
    Date of birth: 27.02.1978
    Research title: Application of spectral and morphological methods to classification of acoustical images of tissues and structures.
    Main results:
    The problem of classifying the images of different biological tissues and composite structures is solved using the spectral and morphological analysis based on the Bayesian method for the statistical hypothesis verification. The basic functions are used being constructed from a learning set. The spatial-spectral approach and its simplified particular realizations in the form of Bartlett's and Pisarenko's methods adapted to the problem are considered. The advantage of these particular methods consists in reduced quantity of computing operations. An extension of the spectral approach to the more general spectral-morphological classification is proposed. The latter takes into account the spatial-spectral features of the structure types to be classified, as well as their morphological features, which manifest themselves in a correlation between the expansion coefficients.
    Main publications:
    1. Burov V.A., Kim E.L. and Rumyantseva O.D. Spectral-morphological analysis of acoustical images of biological tissues and composite structures: Statistical approach // Acoustical Physics (Translated from Akusticheskii Zhurnal). 2005. V.51. ╣1.
    2. Burov V.A., Kim E.L. and Rumyantseva O.D. Classification of acoustic images by spectral-morphological methods // Proc. of the XV Session of the Russian Acoustical Society, Medical and biological acoustics, November 15-18,V.3. P.87-92, 2004.
    3. Burov V.A., Kim E.L. Configurational classification of stochastic structures as a way of tissues classification for acoustical tomography // Acoust. Imag. N.Y.: Kluwer Academic/Plenum Publishers, 2002. V.26. P.273-280.
    4. Burov V.A., Kim E.L. and Rumyantseva O.D. Spectral-morphological analysis of acoustical images of biological tissues and composite structures. II. Test classification of acoustomicroscopical images // Acoustical Physics (Translated from Akusticheskii Zhurnal). 2005. V.51. ╣2.
  8. Denis Neradovsky
    Photo of Denis Neradovsky
    Place of work: Tyumen Branch of Institute of Theoretical and Applied Mechanics of SB RAS.
    Date of birth: 23.05.1981
    Research title: The mathematical model of the bubble cluster on the basic of Lagrange's equations.
    Main results:
    The influence of heat exchange on the dynamics of acoustic influence was numerically investigated. It is established that dissipation of oscillation energy of bubbles due to interphase heat exchange and fluid viscosity leads to amplitude contraction of oscillations of central bubble of cluster. Nevertheless, this amplitude is greater than amplitude of oscillation of single bubble in the same conditions. Evolution of pressure fields of liquid containing bubble cluster is investigated. It is shown that shielding of external pressure impulse by peripheral bubbles is observed as bubbles growth.
    Main publications:
    1. D. F. Neradovsky, I. N. Sannikov. 2004. The effect of heat exchange on the dynamics of bubbles in the cluster at the acoustic influence // Thesis of VIII All-Russian Conf. Of Young Scientists "Actual questions of thermophysics and physical hydro- and gas dynamics". Novosibirsk, 2004. P. 76-77.
  9. Sergey Shlychkov
    Photo of Sergey Shlychkov
    Place of work: The Mari State Technical University.
    Date of birth: 01.08.1970
    Research title: A Computation technique of body members of designs of string musical instruments.
    Main results:
    The numerical-experimental investigations of influencing the acoustic internal cavities (resonator) on spectrum of the eigenfrequencies of a guitar soundboard were done. With the help of a system for vibration diagnostics the set of time-digital sequences (acceleration from time) was obtained. On the basis of methods of digital spectral analysis the spectral concentration of power was estimated. The relations for the soundboard with allowance of a resonator and without it in range up to 1000 Hz were obtained. It is stated, how the presence of the resonator influences dynamic characteristics of a soundboard of an acoustic guitar. The technique of obtaining and analysis of results is particularized in activity. The problem of simulation of dynamic behavior of curvilinear shell designs made of composite materials is put. The approaches to its solution are designed.
    Main publications:
    1. Shlychkov S.V. Investigation of the dynamic characteristics of the sound radiating elements of string musical instruments: Computation and experiment// Wave diffraction and propagation. Proceeding of the XI session of the RAS. ╠.: Geos, 2002. pp. 205-208.
    2. Shlychkov S.V. The influence of the bracing geometry on the resonance characteristic of a guitar soundboard// Proceeding of the XIII session of the RAS. ╠.: Geos, 2003. pp.210-213.
    3. Shlychkov S.V. About influencing an acoustic resonator on the dynamic characteristics of a guitar soundboard// Acoustical measurements and standardization. Proceeding of the XV session of the RAS. P. 265-268.
  10. Vasilisa Solntseva
    Photo of Vasilisa Solntseva
    Place of work: Andreyev Acoustics Institute
    Date of birth: 24.02.1981
    Research title: Aeroacoustics of waveguides with corrugated walls.
    Main results:
    The air flow in the corrugated pipe generates the tone or multitone noise. This sound looks like the flute one and at first sight it is not connected with the pipe size - the pipe length could be a few meters or a half-meter, but the main frequency of pipe noise is located in the same region. The measured spectrum show that the noise is a collection of closely located peaks distributed in a narrow band region with central frequency proportional to the flow velocity and inversely to the corrugation period. The noise mechanism is very stable and acoustic output at the duct outlet is very high. The sound generation begins when the air velocity is higher some threshold value.
    When external sound field presents in the corrugated tube with flow, the following phenomena are observed. In the absence of the flow the spectrum of the sound radiated at the tube outlet has typical view with the resonant peaks at the tube fundamental frequencies. For small velocities only a little change in the low frequencies area is observed. When the flow velocity becomes higher then the threshold value peaks at high frequencies increase (sound generation), but at low frequencies peaks height decreases more than 2 times. When the flow velocity grows more, the resonance peaks increasing range moves to higher frequencies, but the decrease (i.d. absorption of sound) takes place now on both low and high frequencies. This effect is described quantitatively.
    Main publications:
    1. Gorenberg A.Y., Dolgih V.A., Kamenets F.F., Mironov ╠.└., Sizov I.I., Solntseva V.S. Aeroacoustic researches on periodically non-uniform waveguides. In the handbook: Acoustic waveguides/ under edition N.└. Dubrovskiy, F.F. Kamenets. Moscow: Publishing house of MIPT, 2003.
    2. V.F. Kopiev, ╠.└. ╠ironov, V.S. Solntseva, I.I. Sizov, └.Y. Gorenberg. Absorption and generation of a sound by air flow in waveguid with periodically rough borders. Proceedings of XIII conference of the Russian Acoustical Society, Moscow, GEOS, 2003.
    3. Solntseva V.S. Absorption of a sound in the corrugated tube with a flow of air. Proceedings of XLVI scientific conference MIPT. Part 2, p. 48. Moscow, 2003.
    4. V.F. Kopiev, ╠.└. ╠ironov, V.S. Solntseva. Aeroacoustic interactions in the corrugated waveguides. Proceedings of XIV conference of the Russian Acoustical Society, Moscow, GEOS, 2004.
  11. Michail Uleysky
    Place of work: Il'ichev Pacific Oceanological Institute of the Russian Academy of Sciences.
    Date of birth: 14.11.1980
    Research title: Ray dynamics in spatially inhomogeneous underwater sound channel.
    Main results:
    The present study was mainly devoted to the phenomenon of a remarkable stability of the steep rays forming the early portion of the received pulse. At first we considered an idealistic model of a periodic spatial inhomogeneity. It was found that decreasing of the vertical length scale of perturbation's oscillations leads to suppressing of chaos of the steep rays, while the flatter rays become strongly chaotic. The resonant interaction of ray motion with vertical perturbation's oscillations can amplify chaos in local areas in the phase space. An analytical criterion of stabilization of the steep rays was derived. At the next step we considered stochastic sound-speed perturbation. It was found that the strength of chaos depends on ray topology in a similar way. When the vertical oscillations are slow, the coherent ray clusters in the late portion of the arrival pattern can be formed. A link between coherent clusters and stable regions in the phase space was demonstrated analytically and numerically. With decreasing of the vertical length scale of perturbation's oscillations the coherent clusters are found to be destroyed and the flatter rays become unstable with fast diffusion in the phase space.
    Main publications:
    1. D.V. Makarov, M.Yu. Uleysky, S.V. Prants. On possibility of determining internal waves characteristics with the help of distributions of ray's travel times in an underwater sound channel under chaos conditions. //Technical Physics Letters. V. 29, N 5, P. 430--432 (2003).
    2. D.V. Makarov, M.Yu. Uleysky, S.V. Prants. Ray chaos and ray clustering in an ocean waveguide.// Chaos. V. 14, N. 1, P. 1-17 (2004).
    3. S.V. Prants, M.Yu. Uleysky. Atomic fractals in cavity quantum electrodynamics. // Physics Letters A. V. 309 N5-6 (2003) 357-362.
  12. Nataliya Zhukova (Kartamisheva)
    Photo of Nataliya Zhukova (Kartamisheva)
    Place of work: Taganrog State University of Radio Engineering.
    Date of birth: 15.07.1981
    Research title: The investigation of acoustic waves' dispersion on the surface of a complex shape.
    Main results:
    The subject of investigation is the simulator of plane acoustic wave dispersion by the cranium's surface. Preliminary was made the computational modeling of plane acoustic wave's dispersion, the wave falls on the verge of the curved surface with the average radius of curvature that is much more then wave-length (the sizes diffusing subject are too big in comparison with the length of the wave). The investigations of phase-reflected wave change were made within Frenel region under the different forms of reflector (surface, crescent, hemisphere, semi-cylinder). For the complex form of the surface (hemisphere, semi-cylinder) was entered the assumption of the radius of curvature reflector's change according to the sinusoidal law. The analyses of design data have showed that the change of the surface curvature, that changes in time, entails the change of reflected-wave's phase. Thus, measuring the wave's phase on the distance, limited by Frenel region, from the surface of a complex form it's possible to estimate the change of radius of surface's curvature. Now the image of frozen trail of an object that is situated under the layer of dissimilar dispersers is received. Using the method of speckle-interferometry the computational modeling of determination of the depth of object's deposition for the sound source is made, that is situated in the distant wave zone of the receiving antenna, under the permanent position of the object and dispersers. Speckle-interferometry methods are applied to determine the depth of an object located under a layer of scatters. This algorithms estimates distances to the object and to the layer with accuracy, determined by the wavelength size of the receiving antenna. As you know biologic signal usually corrupted with noise and information cannot be available directly from the raw signal. The computational modeling was done without taking account any acoustical noises. However there are many additional coherent interferences at real conditional. The main reasons of that problems are a presence inhomogeneous layers and scattered objects in the propagation region (in this case - hair in the cranium surface). Usually the noisy interference level greatly exceed reflected signal, which contained significant information. The decision for this problem was found using speckle-interferometry method. The initial method was modificated and a good agreement between theory and simulated results was achieved. This theory might be used for the investigation of bones' mobility of the cranium, for predicting possible attacks of decease, and in research of the breathing dynamics.
    Main publications:
    1. Voronin V.A., Kartamisheva N.S. The problem solution of determination wave's reflection field from the object with the complex shape. // Taganrog, Izvestiya TRTU. 2003, ╣6.
    2. Voronin V.A., Kartamisheva N.S. The research of the surface fluctuations signs. // Collection of reports "APEE", NGTU. 2004.
    3. Voronin V.A., Kartamisheva N.S. The research of acoustic wave's dispersion from the moving surface, covered by the layer of heterogeneous diffuser. // Taganrog, Izvestiya TRTU. 2004, ╣7.
IIAV scholars
  1. Arkady Mikhalev
    Place of work: Saint-Petersburg State University, Department of Solid State Physics, Laboratory of Quantum Acoustics and Ultrasonic Spectroscopy.
    Date of birth: 17.10.1969
    Research title: Dependence of acoustic properties of the heterogeneous systems on consideration and of spacial distribution of the dispersed phase in a matrix.
    Main results:
    The studies were dealt with the consideration of heterogeneous systems acoustic properties dependence on the concentration, physical properties and the structure of spacial distribution of the dispersed phase in a matrix. The measurements were held at 3 MHz in the range of volume concentrations from 0 up to 50%. 10% gelatine solution is used as the matrix and particles of various sizes (3-40 mcm) with rather different physical properties (glass spheres, glass and metal particles ) are used as the dispersed phase. The attenuation, scattering, back-scattering, the reflection coefficient and ultrasonic waves velocity were measured. From the results of our previous studies three regions of concentrations with specifical for each another character of the acoustic properties dependence on the dispersed phase concentration were determinated. It was supposed that these differencies were arised from the structure rearrangements inside of the heterogeneous system. The further experiments may be of interest for the evolution of the ultrasonic waves propagation in heterogeneous systems theory (particularly in a range of percolation concentration of the dispersed phase) as well as for the development of non-destructive methods to control the materials` properties.
    Main publications:
    1. I.S.Koltzova, Mukel Mysun and A.Y.Mikhalev Propagation of Ultrasound in Disperse, Porouse and Composite Materials.// Proc. of the X-th Sess. of RAS Moscow. 2000, Vol.2. P.99-101.
    2. I.S.Koltzova and A.Y.Mikhalev. Concentrational Dependences of Velocity of Ultrasonic Waves Spreading in Composites.// Proc. of the XI-th Sess. of RAS Moscow. 2001 Vol.2. P.244-246.
    3. I.S.Koltzova, E.N.Dyatlova, M.A.Ivanov and A.Y.Mikhalev. Propagation of Ultrasonic Waves in Ferrocomposites.// Proc. of the XIII-th Sess. of RAS Moscow 2003 Vol.1. P.88-91.
  2. Alexsandra Teplyakova
    Place of work: St.-Petersburg State Electric Engineering University. (SPGETU), dept. Electroacoustics and Ultrasound Techniques.
    Date of birth: 10.10.1981
    Research title: The scattering properties of resilient infinitely long cylindrical obstacle with unregular structure in the solid medium and finite system of obstacles with normal drop of elastic wave.
    Main results:
    There were examined the scattering properties of resilient infinitely long cylindrical obstacle with unregular structure in the solid medium and finite system of obstacles with normal drop of elastic wave. A disturbance of adhesive bond on the part of the surface of cylindrical engaging limited by too generatrix is implied by unregular structure. Cylinders in the system can have different dimensions and can be located arbitrary. On the surface of each cylinder, of the system, can be observed a disturbance of adhesion within the limits of some sector. Disposition and dimension of this sector are arbitrary. Received solutions - coefficients of dispersion permit to components of the voltage and the displacement in the scattering wave and to calculate estimate the efficiency of conversion of waves's types at scatter. There were examined different combinations of materials of base medium and engaging. When there is a diffraction on lone engagings, as when it is on the finite system of engaging, there is observed abrupt changes of scattering field under fixed angle of sector exposure with disturbed adhesion. By the direction of incident wave has a place marked base lobe, which becomes pointed as wave distance between long axes of cylinders is increases. For numerical testing of received results and also for practical recommendations in realization of ultrasonic control of real production on basis of Fourier conversion received and analyzed the acoustical section equation of ultrasonic conversion. Adjusted dependences for definition of equivalent dimensions of obstacles (taking into account interfaces of metal - engaging) were received.
    Main publications:
    1. Abbakumov K.E., Gorbatsevitch V.F., Novokshonov D.B., Teplyakova A.B. Particularities of scattering properties of sphere obstacles with unregular structure. // Proc. of the XI-th Sess. of RAS, V.1, Moscow, GEOS, 2001, P.198-201.