The spreading of a tracer in a bubbly two-phase grid-generated turbulent flow system is studied. In this work both particle image velocimetry (PIV) and planer laser-induced <span style="font-size: 10pt...

Differential enforcement of employment protection by explicit design of the legislation, for example through exemptions for small firms, has been exploited in a growing body of research. However, little is known about the effects of differential enforcement that is not defined by the letter of the law, presumably due to the lack of data. Our study incorporates aspects of both types of different...

Suppose that f and f ′ are axiom A flows with attractors A and A′. Then the attractor A×A′ for the product flow gt = ft×f ′ t on the product manifold is no longer hyperbolic (although there is a hyperbolic action of R2). It is easy to see that the attractor cannot explode but we show here that it cannot implode: for any flow (ht) sufficiently close to (gt) any attractor whose basin is not too t...

Let G be a Lie group and Γ be a discrete subgroup. We show that if {μn} is a convergent sequence of probability measures on G/Γ which are invariant and ergodic under actions of unipotent one-parameter subgroups, then the limit μ of such a sequence is supported on a closed orbit of the subgroup preserving it, and is invariant and ergodic for the action of a unipotent one-parameter subgroup of G.

The number of computational cells assigned to a small bubble is liable to be small in a volume tracking simulation of a poly-dispersed bubbly flow. The volume tracking method is, therefore, expected to at least give qualitatively reasonable predictions of bubble motion without assigning many cells. In this study, bubble motions in stagnant water and shear flows are simulated with low spatial re...

We report observations of a striking reversal in the direction of electroosmotic flow (EOF) outside a conical glass nanopore as a function of salt concentration. At high ionic strengths (>100 mM), we observe EOF in the expected direction as predicted by classical electrokinetic theory, while at low salt concentrations (<1 mM) the direction of the flow is reversed. The critical crossover salt co...

The paper describes the implementation of stress dependent boundary conditions in the FEMTOOL code developed for numerical solution of coupled problems. Moving interface flows including breaking waves are considered. The performance of the numerical technique is validated by solving the dam break problem in the confined domain. The code development issues and the detailed investigation of param...