This paper studies the influence of convection by periodic or cellular flows on the effective diffusivity of a passive scalar transported by the fluid when the molecular diffusivity is small. The flows are generated by two-dimensional, steady, divergence-free, periodic velocity fields.

We compute periodic, analytic and local cyclic cohomology for convolution algebras of compact Lie groups in order to exhibit differences between these theories. A surprising result is that the periodic and analytic cyclic cohomology of the smooth convolution algebras differ, although these algebras have finite homological dimension.

cyclic neutropenia is a rare immunodeficiency syndrome, characterized by regular periodic oscillations in the circulating neutrophil count from normal to neutropenic levels through 3 weeks period, and lasting for 3-6 days. in order to determine the clinical features of cyclic neutropenia, this study was performed. seven patients with cyclic neutropenia (3 males and 4 females), who experienced n...

As originally formulated, the Generalized Alignment Index (GALI) method of chaos detection has so far been applied to distinguish quasiperiodic from chaotic motion in conservative nonlinear dynamical systems. In this paper, we extend its realm of applicability by using it to investigate the local dynamics of periodic orbits. We show theoretically and verify numerically that for stable periodic ...

Fluid flows play a central role in scientific and technological development, many of these are characterized by dominant oscillation, such as the vortex shedding wake nearly all transportation vehicles. The ability to control is critical improve aerodynamic performance unsteady fluid flow systems. This goal requires precise characterization how perturbations affect long-time phase oscillatory f...