Tracer diffusivity in a time or space dependent temperature field
ArXiv cond-mat/0206500 (2002)
Abstract:
The conventional assumption that the self-diffusion coefficient of a small tracer can be obtained by a local and instantaneous application of Einstein's relation in a temperature field with spatial and temporal heterogeneity is revisited. It is shown that hydrodynamic fluctuations contribute to the self-diffusion tensor in a universal way, i.e. independent of the size and shape of the tracer. The hydrodynamic contribution is anisotropic--it reflects knowledge of the global anisotropy in the temperature profile, leading to anisotropic self-diffusion tensor for a spherical tracer. It is also retarded--it creates memory effects during the diffusion process due to hydrodynamic interactions.Radial distribution function of rod-like polyelectrolytes
European Physical Journal E 9:1 (2002) 41-46
Abstract:
We study the effect of electrostatic interactions on the distribution function of the end-to-end distance of a single polyelectrolyte chain in the rod-like limit. The extent to which the radial distribution function of a polyelectrolyte is reproduced by that of a wormlike chain with an adjusted effective persistence length is investigated. Strong evidence is found for a universal scaling formula connecting the effective persistence length of a polyelectrolyte with the strength of the electrostatic interaction and the Debye screening length.Relaxation of a moving contact line and the Landau-Levich effect (vol 55, pg 228, 2001)
EUROPHYSICS LETTERS 57:2 (2002) 304-304
Probing the strong boundary shape dependence of the Casimir force.
Phys Rev Lett 87:26 (2001) 260402
Abstract:
We study the geometry dependence of the Casimir energy for deformed metal plates by a path integral quantization of the electromagnetic field. For the first time, we give a complete analytical result for the deformation induced change in Casimir energy delta E in an experimentally testable, nontrivial geometry, consisting of a flat and a corrugated plate. Our results show an interesting crossover for delta E as a function of the ratio of the mean plate distance H, to the corrugation length lambda: For lambda<Dissipation in dynamics of a moving contact line
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics 64:3 I (2001) 316011-316017