Helium-II at (finite) temperature below the transition T ≈ 2.17 K can be described as the superposition of two interacting fluids. A normal fluid which has non-zero viscosity and an inviscid superfluid, in which vorticity is confined to quantized vortices [1]. The large-scale dynamics of these two copenetrating fluids obey respectively the Navier-Stokes and Euler equations (at low Mach number) ...

A finite-volume method is applied to the numerical simulation of flows of viscoelastic fluids in the benchmark confined-cylinder problem under creeping flow conditions. The fluids are modeled using the Oldroyd-B constitutive equation, the calculation of the polymer stress contribution is carried out using the logconformation methodology [1] and the results are compared with data using the stand...

Two types of damping are commonly applied to describe ferromagnets at the macroscopic level: one by Landau and Lifshitz, and the other by Gilbert. This work successively applies the methods of irreversible thermodynamics to insulators, insulating paramagnets, and uniform insulating ferromagnets, in the last case uniquely obtaining Landau-Lifshitz damping. These methods are then applied to non-u...

Several instrumental developments to examine the spectroscopic response of molecularly thin fluids confined between mica sheets are described. They are predicated on using a redesigned surface forces apparatus where dielectric coatings, transparent to light at needed optical wavelengths, retain the ability to measure interferometric thickness at other optical wavelengths. Examples of recent mea...