On generation of a shock wave in a hail protection setup

Problems of generation of a shock wave in a hail protection setup are considered. The results of oscillographing the shock wave by microphones arranges at different altitudes along the direction of its propagation are reported. The average velocity of the shock wave is determined. The processes occurring in the explosion combustion chamber are analyzed using the recorded oscillograms.     

On acoustic stimulation of atmospheric precipitation

Stimulation of atmospheric precipitation by acoustic waves is considered. The interaction of acoustic waves with fog particles and the acoustic coagulation phenomenon are analyzed. It is proposed that the effect of amplification of sound in a weakly ionized gas be used to prevent sound decay away from the source in a foggy environment.     

Superluminescence of atomic oxygen in the upper atmosphere

It is demonstrated that the radiation of red sprites and blue jets formed in the upper atmosphere is due to the superluminescence of highly excited atomic oxygen induced by an acoustic wave. The field observations of the effect of acoustic waves on the atmosphere are presented. The responses that represent high-frequency electromagnetic and optical pulses are obtained. The laboratory experimental study of the gas discharge is performed to simulate the processes in the upper atmosphere.     

A gas laser controlled by an acoustic wave

An acoustically induced laser is described. Conditions for producing an inverse population in the discharge in increased-pressure argon by reducing the intensity of an acoustic wave directed along the positive column are considered.     

Percolation model of relative permeability hysteresis

A mathematical model of relative permeability hysteresis in drainage and imbibition is constructed on the basis of percolation theory. It is shown that the results are in qualitatively agreement with experimental data.     

Characteristics of sound wave generation in a gas discharge

An analysis is made of the generation of sound waves in a dc gas-discharge tube by applying an alternating component, and the optimum generation conditions are determined. Zh. Tekh. Fiz. 67, 53–56 (August 1997)