Capillary oscillations of a drop in an electric field

The capillary oscillations of a conducting spheroidal drop with small eccentricity in an electric field are studied. The effect of the electric field is to lower the natural frequencies of oscillations and the damping coefficient.     

Liquid-crystal diode generator of low-frequency oscillations

The excitation of rhythmic current oscillations in a diode cell containing a nematic liquid crystal is studied. The external electric field in the interelectrode gap is directed parallel to the surfaces which orient the liquid crystal molecules. The current oscillations are accompanied by the formation of an autosoliton at the cathode, which propagates and disappears at the anode. A hypothetical model is proposed to explain this current instability. Zh. Tekh. Fiz. 68, 125–127 (January 1998)     

Characteristics of an electric discharge XeCl laser

The results are given of an experimental investigation into the influence of the parameters of the discharge circuit on the characteristics of an XeCl laser. The unsaturated gain was measured and found to be 15% per centimeter.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 15–19, February, 1981.We thank Yu. I. Bychkov for interest in the work and valuable comments.     

Two types of current oscillations in a low-current spark discharge initiated in a nonuniform electric field

Experimental data for a spark discharge in the tip-plane electrode configuration in argon are considered for the case when the discharge current is limited by a high-resistivity ballast resistor. It is shown that the current passing in the thin plasma channel of a low-current spark represents a steady sequence of regular pulses. It is found that low-frequency current pulses of the low-current spark are accompanied with high-frequency current oscillations of nanosecond duration.     

On the discharge in laser plasma in an external electric field

The possibility of creating discharge in laser plasma in an external electric field with quasi-static current generation along the field is discussed. The knowledge of the quasi-static current generation mechanism in laser plasma, associated with the rarefaction shock wave (RSW), allows the determination of the spatial distribution of these currents during laser irradiation of a planar target. Having included the (planar or cylindrical) target into an external contour, we propose a discharge scheme in laser plasma, where the discharge current increases during the laser pulse.     

The effect of low-frequency oscillations on cardio-respiratory synchronization

We show that the transitions which occur between close orders of synchronization in the cardiorespiratory system are mainly due to modulation of the cardiac and respiratory processes by low-frequency components. The experimental evidence is derived from recordings on healthy subjects at rest and during exercise. Exercise acts as a perturbation of the system that alters the mean cardiac and respiratory frequencies and changes the amount of their modulation by low-frequency oscillations. The conclusion is supported by numerical evidence based on a model of phase-coupled oscillators, with white noise and lowfrequency noise. Both the experimental and numerical approaches confirm that low-frequency oscillations play a significant role in the transitional behavior between close orders of synchronization.     

Dispersion properties of low-frequency electrostatic oscillations in metallic carbon nanotubes

Dispersion properties of low-frequency electrostatic waves in metallic carbon nanotubes (CNTs) are investigated. We assume that metallic CNTs are charged due to the field emission, and hence the metallic nanotubes can be regarded as charged dust rods surrounded by degenerate electrons and ions. We deduce the perturbed electron and ion number densities by using the quantum hydrodynamic model, while the dust rod density perturbation follows the classical expression. The Poisson equation, in turn, gives the dispersion relation for the low-frequency electrostatic oscillations in our three-species bounded plasma system composed of metallic CNTs. The oscillation frequency of CNTs can be used for diagnostic purposes, e.g. for the determination of charge on nanotubes.     

Generation of intense shock waves by an electric discharge in gases

A device for generating intense shock waves at low energies of an electric discharge in a gas is suggested and tested.     

Asymmetry of spontaneous helium radiation in retarded excitation in an electric discharge

The dynamics of formation of optical radiation in spectral lines in a longitudinal nanosecond helium discharge under conditions of wave breakdown is investigated. A discharge tube with a diameter of 0.4 cm and a length of 50 cm was placed in a metallic shield 1 cm in diameter. The gas pressure was varied within 1–60 torr for an amplitude of the voltage pulses of up to 50 kV. Asymmetry of spontaneous radiation recorded from different ends of the discharge tube is detected. This is shown to be a consequence of nonuniform distribution of the functions of the primary brightness of the flux and the absorption coefficient along the tube length. Dagestan State University, 43a, M. Gadzhiev Str., Makhachkala, 367025, Russia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 3, pp. 415–420, May–June, 1999.     

Stages of an electric discharge gliding on a water surface

Three stages of a pulse electric discharge were revealed. The discharge occurred in the atmosphere along a free water surface between a tip placed at some distance from the water surface and a distant electrode immersed in the water. Original Russian Text ? A.F. Aleksandrov, D.N. Vaulin, A.P. Ershov, V.A. Chernikov, 2009, published in Vestnik Moskovskogo Universiteta. Fizika, 2009, No. 1, pp. 95–97.     

Equation of solvated ion oscillations in solution under an external periodic electric field

An equation describing ion oscillations with respect to solvent molecules is derived as a result of the consideration of the interaction of an external electric field with free and bound charges in the volume of a salt solution in a polar dielectric liquid. An analysis of the equation shows that the ion motion represents a drift toward one of the electrodes forming the field in the electroinsulated solution volume if amplitudes and durations of sinusoidal field half-periods are different.