Gurbatov S.N., Enflo B.O., Pasmanik G.V. «Сравнение корреляционных характеристик прямого и обратного рассеяния на пузырьковых слоях» Научная конференция по радиофизике, посвященная 95-летию со дня рождения М.Т. Греховой Нижний Новгород 7 мая 1997 г. Тезисы докладов, с. 86 (1997)

The base of one-dimensional Burgers’ equation with infinitely small viscosity the quantitative and qualitative analyses of the time evolution of pulses with complex structure are performed.

Penelet G., Gusev V., Lotton P., Bruneau M. «Experimental and theoretical studies of nonlinear saturation processes in annular thermoacoustic prime movers» High intensity acoustic waves in modern technological and medical applications. Joint Workshop of Russian Acoustical Society (RAS) and French Acoustical Society (SFA). Special Session of the XVI Meeting of Russian Acoustical Society (Moscow. 14–18 November 2005), с. 65-74 (2005)

The present study gives a simplified analytical description of spontaneous generation and finite amplitude saturation of sound in annular thermoacoustic engines, and also provides comparison with experiments. The model includes the description of thermoacoustic amplification of sound (induced by interaction between an heterogeneously heated stack of solid plates and resonant gas oscillations), which accounts for the details of the temperature distribution in the whole thermoacoustic device. The saturation of the acoustic wave amplitude is described by taking into account both the reverse influence of the acoustic field on the temperature field, and the dissipation of acoustic power due to higher harmonics generation and minor losses (vortex generation). From the comparison between simulation results and experiments, it is demonstrated that the dynamical behavior observed in our experimental device is predominantly controlled by the effects of acoustic streaming and acoustically enhanced thermal conductivity tending not only to reduce the externally imposed temperature gradient along the stack, but also to change the shape of the temperature field in such a way that additional thermoacoustic amplification may occur.

Bou Matar O., Preobrazhensky V., Pernod P. «2D axisymmetric pseudospectral simulation of supercritical phase conjugation of ultrasound in active solid media» High intensity acoustic waves in modern technological and medical applications. Joint Workshop of Russian Acoustical Society (RAS) and French Acoustical Society (SFA). Special Session of the XVI Meeting of Russian Acoustical Society (Moscow. 14–18 November 2005), с. 48-56 (2005)

The problem of supercritical wave phase conjugation (WPC) has no analytical solution far geometry and operation conditions of real conjugators. Hence, to study the influence of reverberations and multiple mode conversions inside the active element of the conjugator on the parametric WPC processus, a 2D axisymmetric numerical modal in developed for supercritical parametric phase conjugation of ultrasound in a solid active element of cylindrical shape and finite length immersed in water. The pseudo-spectral time domain algorithm (PSTD) is used. PSTD solves elastic wave equation in time dependent heterogeneous isotropic and axisymmetric anisotropic solids using FFTs for high order approximation of the spatial differential operator an staggered grid. Complex frequency shifted perfectly matched layers are introduced to truncate the computational domain. It is shown, that retro-focusing of the incident pulse taken place even in the case of mode conversions inside the active zone. Nevertheless, amplitude and form of the obtained conjugate pulse depend on the simulated configuration. Numerical simulation correctly describes the parametric amplification and retro-focusing of ultrasound observed in experiments, when the conjugator is loaded at one end by water, and is free on the opposite one.

Preobrazhensky V., Pernod P., Bunkin F., Brysev A., Krutyansky L., Pyl'nov Yu., Preobrazhensky S. «Nonlinear acoustics of phase conjugate ultrasound beams. ten years of the russian-french collaboration» High intensity acoustic waves in modern technological and medical applications. Joint Workshop of Russian Acoustical Society (RAS) and French Acoustical Society (SFA). Special Session of the XVI Meeting of Russian Acoustical Society (Moscow. 14–18 November 2005), с. 11-20 (2005)

Overview of nonlinear acoustics of phase conjugate waves (PCW) – the new domain of physical acoustics created by the participants of the Joint Russian–French laboratory LEMAC is presented. The original magneto-acoustic technique of supercritical parametric wave phase conjugation (WPC) is used as a basic method of generation of high intensity PCW. The results of experimental and theoretical studies of nonlinear propagation and interaction of PCW in liquids are considered. Compensation of phase distortions and high quality retro-focusing of PCW in nonlinear and inhomogeneous media in conditions of break of time reversal invariance (TRI) are observed experimentally and described theoretically. Selective WPC of the harmonics of nonlinear beams and its application for harmonic imaging are demonstrated on an example of the nonlinear acoustic microscopy. Detection of nonlinear inhomogeneities by means of WPC is described. Low frequency wave generation by nonlinear interaction of high frequency PCW and its use for velocimetry of scattering objects in liquid are discussed. Applications of TRI break for ultrasonic WPC-imaging of flows and the advantages of nonlinear modes of flow imaging are demonstrated.

Lafon C., Gelet A., Cathignol D., Prat F., Chapelon J.Y. «Interstitial and intracavitary therapeutic ultrasound» High intensity acoustic waves in modern technological and medical applications. Joint Workshop of Russian Acoustical Society (RAS) and French Acoustical Society (SFA). Special Session of the XVI Meeting of Russian Acoustical Society (Moscow. 14–18 November 2005), с. 30-35 (2005)

The non invasive nature of High Intensity Focused Ultrasound (HIFU) for thermal ablation of in-depth tumors is very promising and several medical devices are currently commercially available. Techniques using intracavitary or interstitial applicators have been proposed because extracorporeal HIFU techniques are not always suitable for deepseated tumors. Bones or gaseous pockets may indeed be located in the intervening tissue. The objective is to bring the ultrasound source as close as possible to the target through natural routes in order to minimize the effects of attenuation and phase aberration along the ultrasound pathway. Under these circumstances, it becomes possible to use higher frequency, thus increasing the ultrasonic absorption coefficient and resulting in more efficient heating of the treatment region. In contrast to extra-corporeal applicators, the design of intracavitary probes imposes additional constraints relative to size and ergonomy. When associated to modern imaging modalities, these minimally invasive therapeutic devices offer very promising options for cancer treatment.

Preobrazhensky V., Pernod P., Bunkin F., Brysev A., Krutyansky L., Pyl'nov Yu., Preobrazhensky S. «Nonlinear acoustics of phase conjugate ultrasound beams. ten years of the russian-french collaboration» High intensity acoustic waves in modern technological and medical applications. Joint Workshop of Russian Acoustical Society (RAS) and French Acoustical Society (SFA). Special Session of the XVI Meeting of Russian Acoustical Society (Moscow. 14–18 November 2005), с. 11-20 (2005)

Overview of nonlinear acoustics of phase conjugate waves (PCW) – the new domain of physical acoustics created by the participants of the Joint Russian–French laboratory LEMAC is presented. The original magneto-acoustic technique of supercritical parametric wave phase conjugation (WPC) is used as a basic method of generation of high intensity PCW. The results of experimental and theoretical studies of nonlinear propagation and interaction of PCW in liquids are considered. Compensation of phase distortions and high quality retro-focusing of PCW in nonlinear and inhomogeneous media in conditions of break of time reversal invariance (TRI) are observed experimentally and described theoretically. Selective WPC of the harmonics of nonlinear beams and its application for harmonic imaging are demonstrated on an example of the nonlinear acoustic microscopy. Detection of nonlinear inhomogeneities by means of WPC is described. Low frequency wave generation by nonlinear interaction of high frequency PCW and its use for velocimetry of scattering objects in liquid are discussed. Applications of TRI break for ultrasonic WPC-imaging of flows and the advantages of nonlinear modes of flow imaging are demonstrated.

Bou Matar O., Preobrazhensky V., Pernod P. «2D axisymmetric pseudospectral simulation of supercritical phase conjugation of ultrasound in active solid media» High intensity acoustic waves in modern technological and medical applications. Joint Workshop of Russian Acoustical Society (RAS) and French Acoustical Society (SFA). Special Session of the XVI Meeting of Russian Acoustical Society (Moscow. 14–18 November 2005), с. 48-56 (2005)

The problem of supercritical wave phase conjugation (WPC) has no analytical solution far geometry and operation conditions of real conjugators. Hence, to study the influence of reverberations and multiple mode conversions inside the active element of the conjugator on the parametric WPC processus, a 2D axisymmetric numerical modal in developed for supercritical parametric phase conjugation of ultrasound in a solid active element of cylindrical shape and finite length immersed in water. The pseudo-spectral time domain algorithm (PSTD) is used. PSTD solves elastic wave equation in time dependent heterogeneous isotropic and axisymmetric anisotropic solids using FFTs for high order approximation of the spatial differential operator an staggered grid. Complex frequency shifted perfectly matched layers are introduced to truncate the computational domain. It is shown, that retro-focusing of the incident pulse taken place even in the case of mode conversions inside the active zone. Nevertheless, amplitude and form of the obtained conjugate pulse depend on the simulated configuration. Numerical simulation correctly describes the parametric amplification and retro-focusing of ultrasound observed in experiments, when the conjugator is loaded at one end by water, and is free on the opposite one.

Preobrazhensky V., Pernod P., Bunkin F., Brysev A., Krutyansky L., Pyl'nov Yu., Preobrazhensky S. «Nonlinear acoustics of phase conjugate ultrasound beams. ten years of the russian-french collaboration» High intensity acoustic waves in modern technological and medical applications. Joint Workshop of Russian Acoustical Society (RAS) and French Acoustical Society (SFA). Special Session of the XVI Meeting of Russian Acoustical Society (Moscow. 14–18 November 2005), с. 11-20 (2005)

Overview of nonlinear acoustics of phase conjugate waves (PCW) – the new domain of physical acoustics created by the participants of the Joint Russian–French laboratory LEMAC is presented. The original magneto-acoustic technique of supercritical parametric wave phase conjugation (WPC) is used as a basic method of generation of high intensity PCW. The results of experimental and theoretical studies of nonlinear propagation and interaction of PCW in liquids are considered. Compensation of phase distortions and high quality retro-focusing of PCW in nonlinear and inhomogeneous media in conditions of break of time reversal invariance (TRI) are observed experimentally and described theoretically. Selective WPC of the harmonics of nonlinear beams and its application for harmonic imaging are demonstrated on an example of the nonlinear acoustic microscopy. Detection of nonlinear inhomogeneities by means of WPC is described. Low frequency wave generation by nonlinear interaction of high frequency PCW and its use for velocimetry of scattering objects in liquid are discussed. Applications of TRI break for ultrasonic WPC-imaging of flows and the advantages of nonlinear modes of flow imaging are demonstrated.

Gurbatov S.N., Egorychev S.A., Kurin V.V., Pronchatov-Rubtsov N.V., Kustov L.M. «Experimental investigation of an acoustic field radiated by a parametric antenna in longitudinally inhomogeneous waveguides» Труды научной конференции по радиофизике, посвященной 80-летию Нижегородского государственного университета им. Н.И.Лобачевского. 7 мая 1998 г., с. 96 (1998)

The results of laboratory researching in to propagation of low-frequency waves generated as linear, and parametrical antenna in shallow homogeneous and inhomogeneous in thickness hydroacoustic waveguides are described. As a model of grounds in the experiment either aluminum plates lying on a rubber substrate or a rubber substrate were used. Waveguides with a similar ground are described within the framework of Pekeris model.

Didenkulov I.N., Kustov L.M., Pronchatov-Rubtsov N.V., Stromkov A.A. «Methods of the nonlinear acoustic vision of objects and defects» High intensity acoustic waves in modern technological and medical applications. Joint Workshop of Russian Acoustical Society (RAS) and French Acoustical Society (SFA). Special Session of the XVI Meeting of Russian Acoustical Society (Moscow. 14–18 November 2005), с. 128-134 (2005)

Nonlinear acoustic methods are found increasing applications during the last decade. In this paper we describe methods of acoustic imaging based on the nonlinear effects: the combination acoustic scattering and the modulation of high-frequency acoustic wave by low-frequency wave. Acoustic vision of objects at the difference frequency was studied using bubbles as strongly nonlinear scatterers. The experiments were carried out in a water tank with metal objects covered with electrolysis microbubbles to produce highly nonlinear scattering from the object surfaces. Images of the objects were obtained. The nonlinear scattering by bubbles was also used to obtain an image of the cavitation flow. Nonlinear acoustic vision of small (in the scale of wavelength) defects is possible when tomography schemes are applied. We used the method of nonlinear modulation modal spectroscopy for defectoscopy of cracks in metal samples. Results of investigation demonstrate possibilities of the nonlinear acoustic techniques in nondestructive testing of different media.

Gurbatov S.N., Demin I.Yu., Pronchatov-Rubtsov N.V. «The use bispectral analysis for nonlinear diagnosis of soft tissues» High intensity acoustic waves in modern technological and medical applications. Joint Workshop of Russian Acoustical Society (RAS) and French Acoustical Society (SFA). Special Session of the XVI Meeting of Russian Acoustical Society (Moscow. 14–18 November 2005), с. 100-104 (2005)

The evolution of higher-order spectral functions of random waves propagating in a nonlinear medium are investigated. The possibility of recovering the input spectrum from the measured spectrum and bispectrum at the output of the nonlinear medium is discussed. A method of measurement of nonlinear propagation characteristics of low frequency vibration in the tissues by using bispectral analysis has been described.

Preobrazhensky V., Pernod P., Bunkin F., Brysev A., Krutyansky L., Pyl'nov Yu., Preobrazhensky S. «Nonlinear acoustics of phase conjugate ultrasound beams. ten years of the russian-french collaboration» High intensity acoustic waves in modern technological and medical applications. Joint Workshop of Russian Acoustical Society (RAS) and French Acoustical Society (SFA). Special Session of the XVI Meeting of Russian Acoustical Society (Moscow. 14–18 November 2005), с. 11-20 (2005)

Overview of nonlinear acoustics of phase conjugate waves (PCW) – the new domain of physical acoustics created by the participants of the Joint Russian–French laboratory LEMAC is presented. The original magneto-acoustic technique of supercritical parametric wave phase conjugation (WPC) is used as a basic method of generation of high intensity PCW. The results of experimental and theoretical studies of nonlinear propagation and interaction of PCW in liquids are considered. Compensation of phase distortions and high quality retro-focusing of PCW in nonlinear and inhomogeneous media in conditions of break of time reversal invariance (TRI) are observed experimentally and described theoretically. Selective WPC of the harmonics of nonlinear beams and its application for harmonic imaging are demonstrated on an example of the nonlinear acoustic microscopy. Detection of nonlinear inhomogeneities by means of WPC is described. Low frequency wave generation by nonlinear interaction of high frequency PCW and its use for velocimetry of scattering objects in liquid are discussed. Applications of TRI break for ultrasonic WPC-imaging of flows and the advantages of nonlinear modes of flow imaging are demonstrated.