A closed excitable pathway with one point-to-point connection is used to generate a rotating wave both in experiments using the photosensitive Belousov-Zhabotinsky system and numerically with an Oregonator reaction-diffusion model. By varying the excitability and geometrical properties of the medium, propagation can be made unidirectional or bidirectional, giving rise, respectively, to the exis...

Unstable concentration gradients inherent in traveling chemical waves can give rise to buoyancy-driven convection, altering the speed of the wave. When an excitable Belousov– Zhabotinsky reaction system is confined within a sufficiently narrow, vertical two-dimensional channel, convection arises at a symmetry-breaking bifurcation point. The observed linear rate of change of wave speed with the ...

We demonstrate the existence of steadily translating filaments in the Belousov-Zhabotinsky reaction. The filaments have self-reinforcing shapes tracing planar hairpins and constant velocities that are inversely proportional to their width. These features are well described by an analytical solution of the mean curvature flow problem. Using numerical simulations based on an excitable reaction-di...

Spatiotemporal networks are studied in a photosensitive Belousov-Zhabotinsky medium that allows both local and nonlocal transmission of excitation. Local transmission occurs via propagating excitation waves, while nonlocal transmission takes place by nondiffusive jumps to destination sites linked to excited sites in the medium. Static, dynamic, and domain link networks are experimentally and co...

Experimental and computational studies of the formation and evolution of scroll waves in three-dimensional excitable media are presented. Scroll waves are initiated in the photosensitive Belousov-Zhabotinsky reaction by perturbing traveling waves transverse to their direction of propagation. Scroll rings are generated by perturbing circular waves, which expand or contract depending on the stren...

Wave propagation in a photosensitive, subexcitable Belousov-Zhabotinsky medium is made possible by periodic modulation of a homogeneous illumination field. The propagation can be understood in terms of an interplay between the radial expansion of the wave and the motion of its free ends as the excitability varies periodically. This description leads to a simple kinematic analysis that provides ...

Chemical waves are initiated in an excitable medium by resonance with local periodic forcing of the excitability. Experiments are carried out with a photosensitive Belousov-Zhabotinsky medium, in which the excitability is varied according to the intensity of the imposed illumination. Complex resonance patterns are exhibited as a function of the amplitude and frequency of the forcing. Local reso...

Integration of a larger stiff system initial value problems emerging from chemical kinetics models requires method that is both efficient and accurate, with large absolute stability region. To determine the solutions ordinary differential equations help in explaining chemically reactive flows, numerical integration methodology known as 3-point variable step block hybrid has been devised. An app...