Biomedical subjects

K Avinash

Publications and source records attributed to K Avinash.

10 recordsLinked to original sources

PubMed2003

Nonlinear theory of void formation in colloidal plasmas.

A nonlinear time-dependent model for void formation in colloidal plasmas is proposed. For experimentally relevant initial conditions, the model describes the nonlinear evolution of a zero-frequency linear instability that grows rapidly in the nonlinear regime and subsequently saturates to form a void. A number of features of the model are consistent with experimental observations under laboratory and microgravity conditions.

Journal Article↗

PubMed2002

Evolution of a dust void in a radio-frequency plasma sheath.

The onset and growth of a dust void are investigated in a radio-frequency (rf) sheath of a capacitively coupled argon plasma. A circularly symmetric void emerges and grows with increasing rf power and pressure in the central region of the dust cloud levitating in the sheath. Experimental measurements of the void diameter are compared with the predictions of a simple phenomenological theory, based on a balance of forces on dust grains.

Journal Article↗

PubMed2002

Phonon spectrum in a plasma crystal.

The Fourier spectra of longitudinal and transverse waves corresponding to random particle motion were measured in a two-dimensional plasma crystal. The crystal was composed of negatively charged microspheres immersed in a plasma at a low gas pressure. The phonons were found to obey a dispersion relation that assumes a Yukawa interparticle potential. The crystal was in a nonthermal equilibrium, nevertheless phonon energies were almost equally distributed with respect to wave number over the entire first Brillouin zone.

Journal Article↗

PubMed2002

Statistical mechanics of axisymmetric vortex rings.

We construct maximum entropy states of a collection of interacting uniform (omega/R=const) axisymmetric vortex rings in a semiperiodic bounded volume. Following Miller [Phys. Rev. Lett. 65, 2137 (1990)] and Robert and Sommeria [J. Fluid Mech. 229, 291 (1991)], we obtain an equilibrium measure that preserves all the ideal invariants such as the total energy, total impulse, circulation, and an infinity of Casimirs. The numerical solution for a wide range of total flow energy and for given values of total circulation and total impulse is presented.

Journal Article↗

PubMed2001

Phase transitions in Euler fluids.

Phase transitions in two-dimensional (2D) Euler fluids are studied using mean field theory (MFT) solutions and Monte Carlo simulations. The MFT solutions show the possibility of first and second order phase transitions and the critical pointlike behavior. The simulations of the dynamics of 2D vortex patches agree with the MFT solutions over a wide range of parameters except at high energies where there are deviations between the two.

Journal Article↗

PubMed1996