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)

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.