Search

The formation of structured films consisting of ensembles of micro- or nanoparticles and possessing preset functional characteristics is studied both experimentally and theoretically. The films are obtained by drying out droplets of colloidal solutions on a solid substrate under the acoustic effect produced by a standing SAW field. [ABSTRACT FROM AUTHOR]

Expressions for calculating the directional characteristics of an array of sound receivers positioned in a waveguide with impedance walls are obtained from the solution to the problem on the diffraction of a plane sound wave by the waveguide open end with impedance flanges. The waveguide can be of a finite length, and, in this case, it can be considered as an open cavity in an impedance screen. The solution of the integral equation for the sound pressure distribution over the opening area is reduced to the solution of an infinite system of algebraic equations for the coefficients of the field expansion in normal waveguide waves. Examples of calculated directional characteristics are presented for arrays with receivers positioned at different distances from the opening and for different values of the impedances of the waveguide walls and flanges. [ABSTRACT FROM AUTHOR]

Focuses on reports presented at the Saint Petersburg workshop on computational and theoretical acoustics of the Scientific Council on Acoustics of the Russian Academy of Sciences. I.V. Andronov's reports on wave propagation along a narrow crack in an elastic plate in contact with an acoustic medium; A.V. Aref'ev study on the propagation of waves of different origin in smoothly inhomogeneous stratified media.