Abstract
A prominent feature of turbulence is the enhancement of mixing or diffusion effects, generally contributing to the loss of macroscopic steeply-varying structures in flows. In a variety of flows, however, those structures may persist against diffusion effects. This fact suggests the existence of some action balancing with diffusion effects. In the present talk, such balancing process is sought in light of the concept of diffusion and counterdiffusion in turbulent flows related to combustion, the transport barrier in fusion-plasma confinement, swirling effects in engineering and astronomical jets, etc
