. 1996. Sound scattering by hydrodynamic wakes of sea animals. -ICES Journal of Marine Science, 53: 377-381.It was observed that the hydrodynamic wake of sea animals such as squid or dolphin can have a considerably greater target strength than that of the animal itself.1996 International Council for the Exploration of the Sea
Bubbles in a subsurface ocean layer play a significant role in underwater acoustics and oceanography. Many works have been devoted to different methods of bubble density measurement. Among them, the nonlinear methods of bubble sizing based on combination acoustic scattering have a very high selectivity. These methods were utilized in several types of bubble counters developed in the Institute of Applied Physics for the last decade. In the devices the difference and the sum frequency waves of the incident ones generated by a bubble in the working volume are detected. Another approach to the problem based on the parametric generation of subharmonic of the incident wave frequency was also tested. The results of the measurements of bubble size distribution and density in the subsurface ocean layer and in the wakes of ships are given in the paper. Simulteneous measurements by different linear and nonlinear methods were done to make a comparison between them. The results of linear acoustic echosounding of a subsurface bubble cloud from an underwater research platform are also presented. Possibilities and advantages of linear and nonlinear methods of spectroscopy of structure and movements in a subsurface layer are discussed. [Work supported by RFBR (Grants 94-05-16755, 95-05-15632).]
The present paper describes the results of measurements of hydrogen peroxide concentration in water under the action of relatively low-frequency sound without cavitation. Measurements of hydrogen peroxide concentration have been carried out with a high-sensitivity chemoluminescent method which has been elaborated for these experiments. De-ionized, degassed, high-purity water has been used. Acoustic resonators of a quarter of a sound wavelength were used as vertical columns made from high-purity quartz glass. Resonance frequencies were 1.2, 5.6, and 15 kHz. The pressure amplitude in the node at the hard bottom was smaller than 0.6 atm. The formation and accumulation of hydrogen peroxide were observed. For example, for the 20 °C water temperature and 1.2-kHz frequency the rate of increasing concentration rate is equal to 2×10−11 mol/(ℓ/h) for the degassed water and 8×10−10 mol/(ℓ/h) for a solution of magnesium sulfate in degassed water with a concentration similar to the one of the sea. The absence of gas bubbles was controlled by optical and acoustical methods. It is known that the appearance of hydrogen peroxide is a result of dissociation of a part of the water molecules. A hypothesis on the possibility of dissociation of water molecules at a small energy density due to acoustical and mechanical action is discussed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.