Rheotropism of the dowser texture.

In spite of its metastability, the pseudo-planar texture of a nematic layer confined between surfaces with homeotropic anchoring can be preserved indefinitely in certain conditions. The pseudo-planar texture, dubbed "the dowser texture", is degenerated and therefore sensitive to perturbations. It has been shown recently that the dowser texture is cuneitropic, that is to say, has a tendency to follow thickness gradients.

Laminar-turbulent cycles in inclined lock-exchange flows.

We consider strongly confined, stably stratified shear flows generated as a lock exchange in a tube inclined at an angle of θ=45(∘). This paper focuses on a transitional regime, in which the flow alternates between two distinct states: laminar, parallel shear flow and intense transverse motion characteristic of turbulence. Laminar-turbulent cycles were captured at Atwood numbers At≡(ρ(2)-ρ(1))/(ρ(1)+ρ(2)) ranging from 2.

Low self-affine exponents of fractured glass ceramics surfaces.

The geometry of postmortem rough fracture surfaces of porous glass ceramics made of sintered glass beads is shown experimentally to be self-affine with an exponent zeta=0.40+/-0.04, remarkably lower than the "universal" value zeta=0.

Dynamical Janssen effect on granular packing with moving walls.

Apparent mass (M(app)) measurements at the bottom of granular packings inside a vertical tube in relative motion are reported. They demonstrate that Janssen's model is valid over a broad range of velocities v. The variability of the measurements is lower than for static packings and the theoretical exponential increase of M(app) with the height of the packing is precisely followed (the corresponding characteristic screening length is of the order of the tube diameter).