Tournat V., Gusev V.E., Zaitsev V.Yu., Nazarov V.E., Castagnede B., Bequin Ph., Inserra C. «Nonlinear acoustic effects in unconsolidated granular 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. 86-92 (2005)

This paper deals with various manifestations of classical and non classical nonlinear acoustic effects that have been observed recently in unconsolidated assemblages of glass beads: operation of the parametric antenna with shear pump waves, non monotonous amplitude dynamics of the longitudinal second harmonic generated from a shear fundamental wave, cross-modulation of propagating waves. Theoretical interpretations of each of these non linear effects demonstrate the important role of the so-called weak contacts, i.e. contacts that support weaker static loads than the average one in the medium. In contrast, the linear wave propagation is mainly affected by the average and strong contacts. As a consequence, nonlinear acoustic methods are found to be much more sensitive than the linear methods for the evaluation of the granular materials in general, and may contribute to a better understanding of their peculiar properties.

Зайцев В., Назаров В., Tournat V., Gusev V., Castagnede B. «Люксембург-горьковский эффект в гранулированной среде» Труды (восьмой) научной конференции по радиофизике, посвященной 80–летию со дня рождения Б.Н.Гершмана. 7 мая 2004 г., с. 209-211 (2004)

Catheline Stefan, Tanter Mickael, Gennisson Jean-Luc, Fink Mathias «Nonlinear propagation of shear waves in soft solids» 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. 81-85 (2005)

Transient elastography has shown its efficiency to map the elastic properties of soft tissues. Now like other elastic imaging techniques (sonoelastography or magnetic resonance elastography) transient elastography is faced to the following problem: in order to properly discriminate tumors, additional information such as viscosity, anisotropy or nonlinearity is needed. If nonlinearity has long been studied in metals, crystals or rocks, only a few experimental works are found in the literature concerning soft tissues and none on shear waves. Thanks to the ultrafast scanner that can map the displacement field of shear waves, we present in this paper an overview of three experiments that allow to illustrate and quantify the nonlinear behavior of soft tissue phantoms. In the first one, a static stress is applied on an Agar-gelatin based sample. The change on the shear wave speed characterizes the nonlinear elastic Landau moduli (A = 50 kPa, B = 7 GPa, C = 11 GPa). The surprising difference found between these constants are thought to be closely related to the huge difference between the linear Lame coefficients (λ>>μ). It is the acoustoelasticity experiment. In the second one, we present an experimental observation of a shock shear wave. The very weak Young’s modulus of the tissue phantom allows one to generate plane shear wave with a Mach number as high as unity. In this extreme configuration, the agreement with the numerical simulation of the modified Burgers equation is remarkable. It is the finite-amplitude shear wave experiment. At last, the interaction between two plane transverse waves with frequencies ω1 and ω2 is carefully studied. Harmonics and secondary waves are created during the propagation at the frequencies (3ω1, 3ω2, ω1+2ω2, ω1–2ω2, ω2+2ω1, ω 2–2ω1). It is the nonlinear interaction experiment. The nonlinear coefficients deduced from the two latter experiments are comparable to the order of magnitude of the Landau coefficients found from the first experiment.

Морозов А.В., Cathignol D., Сапожников О.А. «Исследование колебаний поверхности ультразвуковых излучателей: сравнение методов лазерной виброметрии и акустической голографии» Акустические измерения и стандартизация. Ультразвук и ультразвуковые технологии. Атмосферная акустика. Акустика океана. Сборник трудов 15 сессии Российского акустического общества. Т. 2, с. 21 (2004)

Sapozhnikov O.A., Morozov A.V., Cathignol D. «Acoustic holography and laser vibrometry to characterize vibration of piezoceramic and piezocomposite transducers used in ultrasound therapy» 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. 20-29 (2005)

Acoustic pressure radiated by piezoelectric sources can be predicted based on the normal velocity distribution along vibrating surface. However, up to now, there are no reliable direct methods of surface vibration measurement in liquids. The transducer vibration is frequently considered as being uniform (thickness mode), which may be incorrect due to transducer structure or due to excitation of Lamb waves in it. In this work, a holographic method is developed and experimentally used that enables reconstruction of the radiator vibration pattern. The method includes a measurement of wave amplitude and phase in different points of a plane grid perpendicular to the acoustic axis at some distance from the source, theoretical time reversal of the waveform in each grid-point, and back propagation of the field to the source using the Rayleigh integral. In addition to the holographic approach, vibration of piezoelectric transducers was studied using laser vibrometry. It is demonstrated that the latter method gives wrong results when the transducer is in contact with liquid, because of strong acousto-optic interaction. It is shown that although the acoustic holographic approach has limited spatial resolution (of order of a wavelength), it allows fairly exact prediction of the radiated field pattern.

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.

Chiu Linus Y.S., Chang Andrea, Chen Chi-Fang «Nonlinear Internal Wave Effect on Underwater Acoustic Propagation in Costal Zone» Доклады XI научной школы-семинара академика Л. М. Бреховских "Акустика океана", совмещенной с 17 сессией Российского акустического общества, с. 395 (2006)

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.

Chiu Linus Y.S., Chang Andrea, Chen Chi-Fang «Nonlinear Internal Wave Effect on Underwater Acoustic Propagation in Costal Zone» Доклады XI научной школы-семинара академика Л. М. Бреховских "Акустика океана", совмещенной с 17 сессией Российского акустического общества, с. 395 (2006)

Fuks I., Naygolnykh K., Chernitskii M. «Coherence of the frequency separated signals in the moving ocean» Акустика неоднородных сред. Ежегодник Российского акустического общества. Сборник трудов семинара научной школы проф. С. А. Рыбака, с. 58 (2000)

Kopiev V.F., Zaitsev M.Yu., Chernyshev S.A., Kotova A.N. «On the possible role of vortex rings in a turbulent jet noise» Акустика неоднородных сред. Ежегодник Российского акустического общества. Труды научной школы проф. С.А. Рыбака. Вып. 2, с. 138 (2001)

Chiu Linus Y.S., Chang Andrea, Chen Chi-Fang «Nonlinear Internal Wave Effect on Underwater Acoustic Propagation in Costal Zone» Доклады XI научной школы-семинара академика Л. М. Бреховских "Акустика океана", совмещенной с 17 сессией Российского акустического общества, с. 395 (2006)

Kim Byoung-Nam, Lee Kang Il , Yoon Suk Wang , Choi Bok Kyung , Didenkulov I.N. «Nonlinear parameter estimation in water-saturated sandy sediment with difference frequency acoustic waves» Физическая акустика. Нелинейная акустика. Распространение и дифракция волн. Геоакустика. Сборник трудов 15 сессии Российского акустического общества. Т. 1, с. 172 (2004)

Khokhlova V.A., Blanc-Benon P., Averiyanov M.V., Cleveland R.O. «Diffraction of nonlinear waves in randomly inhomogeneous moving 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. 41-47 (2005)

The combined effects of acoustic nonlinearity and diffraction on the propagation of intense acoustic waves in an inhomogeneous moving medium are investigated Л nonlinear parabolic equation that accounts for diffraction, nonlinearity, absorption, scalar inhomogeneities (density and sound speed) and vectorial inhomogeneities (flaw) is employed, A 2D numerical algorithm is used to solve the equation and to investigate the propagation of initially harmonic waves in media with random inhomogeneities of different types. The results are compared with those obtained using ray theory (within the paradigm of nonlinear geometrical acoustics) in order to investigate the impact of diffraction on focusing in inhomogeneous media. It is shown that the prediction of caustics and shadow zones by nonlinear geometrical acoustics only partially corresponds to the regions of high and low pressure levels predicted with the nonlinear parabolic wave equation. The discrepancy between the results of the models increases for smaller size of inhomogeneities and for longer distances in randomly inhomogeneous media. When nonlinearity is present distorted waveforms are obtained in the diffraction field even in the shadow zones of decreased pressure due to scattering of higher frequencies from the areas of focusing.

Воронович А.Г., Осташов В.Е., Colosi J.A., Cornuelle B.D., Dushaw B.D., Dzieciuch M.A., Howe B.M., Mercer J.A., Spindel R.C., Worcester P.F. «Исследование горизонтальной рефракции акустических сигналов по данным акустической лаборатории NPAL» Доклады 9 научной школы-семинара академика Л. М. Бреховских "Акустика океана", совмещенной с 12 сессией Российского акустического общества, с. 88 (2002)

Воронович А.Г., Осташов В.Е., Colosi J.A., Cornuelle B.D., Dushaw B.D., Dzieciuch M.A., Howe B.M., Mercer J.A., Spindel R.C., Worcester P.F. «Исследование горизонтальной рефракции акустических сигналов по данным акустической лаборатории NPAL» Доклады 9 научной школы-семинара академика Л. М. Бреховских "Акустика океана", совмещенной с 12 сессией Российского акустического общества, с. 88 (2002)