Physics Colloquium
Friday, September 24th, 2004, 4:00 P.M.
E300 Math/Science Center; Refreshments 3:30 P.M. Room E200 Math/Science Center
Kenneth Showalter
Department of Chemistry, West Virginia University
Controlling Spatiotemporal Dynmics in Chemical Systems
Chemical waves are propagating concentration disturbances, typically with constant velocities and concentration profiles, that arise from the coupling of autocatalytic reaction with molecular diffusion. Wave propagation is influenced by medium inhomogeneities and can be supported by imposed noise. The excitability limit for spiral waves can be characterized by stabilizing unstable waves with a feedback control algorithm. Wave behavior can be controlled by imposing feedback-regulated excitability gradients to guide propagation in specified directions. The relevance of these features to wave behavior in biological systems will be discussed. [T. Sakurai, E. Mihaliuk, F. Chirila, and K. Showalter, "Design and Control Patterns of Wave Propagation Patterns in Excitable Media," Science 296, 2009-2012 (2002).]
|
