Igor Margulis

Work: Measurement of acoustic power at cavitation. Laboratory of Sonochemistry of Acoustics Institute.

Date of birth: September 5, 1977.

Place of birth: Moscow, Russia.

Education: 2000, Graduated from Moscow Engineer-Physics Institute (Technical University).

E-mail: .

Main results: Determination of acoustic power of ultrasound sources that operate at cavitation is a very difficult problem and only the comparative calorimetric method can be used to determine this power absolutely (e.g. in Watts). It is based on continuous registration of temperature T course on time t at the action of ultrasound and the heater. If the curves T(t) are very close, the heater power is considered as an equivalent of the acoustic power absorbed in liquid. If this method is used, one doesn't need to know exactly the bubbly liquid impedance, the transducer conversion coefficient etc. Measurements can be carried out independently on type of irradiators and sound frequency. Accordingly to this method, we have developed for the first time the device that can measure absolutely (e.g. in Watts) the irradiated acoustic power and that one absorbed in a total volume of liquid at cavitation regime. We have obtained high accuracy (3%) at measurements of acoustic power in a wide range. But at the special conditions (for example, measurements are done inside the sound transparent vessel) a part of sound energy can go out from the considered volume and only absorbed acoustic power can be measured. We have concluded that at developed cavitation the absorbed (and irradiated) acoustic power doesn't depend on geometry of vessel, volume of liquid and depth of horn submergence if the form of cavitation cloud is unchangeable. These results can be used, for example, at calibration of ultrasound equipment, for scientific applications at studying of processes at cavitation regime etc.

Main publications:

1. Account of imperfect vapour-gas mixture pressure at studying of cavitation bubble dynamics, Russ. J. Phys. Chem., v.75, p.527-535, 2001.
2. M.A. Margulis, I.M. Margulis, Contemporary review on nature of sonoluminescence and sonochemical reactions, 7th Meeting of the European Society of Sonochemistry, Biarritz, France, May 14-18, 2000.
3. M.A. Margulis, I.M. Margulis, Contemporary review on nature of sonoluminescence and sonochemical reactions, Ultrasonics Sonochemistry, 2001 (in printing).
4. I.M. Margulis, M.A. Margulis, The Mechanism of Sonoluminescence and Sonochemical Reactions, International Conference "Ultrasonic Technological Processes - 2000", Severodvinsk, Russia, 27-30 September, 2000.
5. M.A. Margulis, I.M. Margulis, New Experimental Evidence of Electrical Nature of Multibubble Sonoluminescence, Russ. J. Phys. Chem., 2001, v.75 (in printing).