The finite wavelength instability generates trigger and packet waves in an extended three-variable Brusselatortype model. The trigger waves account for experimentally observed stacking (shock) structures and acceleration of oncoming waves before collision observed in the Belousov-Zhabotinsky system. Packet waves exhibit specular reflection from surfaces. The mouth of a narrow tube connected to ...

The temporal degradation of the Belousov-Zhabotinskii substrates lactic acid, pyruvic acid, bromoand dibromo pyruvic acid is investigated. The only final product of non-brominated substrates is acetic acid. From brominated educts only brominated acetic acids result. The con­ centrations of the stable products are determined as a function of time. The gross reactions are mainly based on simple c...

In this paper we revisit the existence of traveling waves for delayed reaction diffusion equations by the monotone iteration method. We show that Perron Theorem on existence of bounded solution provides a rigorous and constructive framework to find traveling wave solutions of reaction diffusion systems with time delay. The method is tried out on two classical examples with delay: the predator-p...

Resonance regions similar to the Arnol'd tongues found in single oscillator frequency locking are observed in experiments using a spatially extended periodically forced Belousov-Zhabotinsky system. We identify six distinct 2:1 subharmonic resonant patterns and describe them in terms of the position-dependent phase and magnitude of the oscillations. Some experimentally observed features are also...

We discuss a novel type of spatiotemporal pattern that can be observed in subexcitable media when coupled to a thermal environment. These patterns have been recently observed in several different types of systems: a subexcitable photosensitive Belousov-Zhabotinsky reaction, hippocampal slices of rat brains, and astrocyte syncytium. In this paper, we introduce the basic concepts of subexcitable ...

Cluster-cluster transitions in the periodically illuminated photosensitive Belousov-Zhabotinsky (BZ) reaction-diffusion system exhibit the same scenario as in the autonomous BZ system with negative global feedback: two-phase clusters <--> three-phase clusters <--> irregular clusters <--> localized clusters. Transitions induced by changing the dark ( TD) or light ( TL) phases of the periodic ext...

We describe a novel nucleation mechanism of scroll rings in three-dimensional reaction-diffusion systems with anomalous dispersion. The vortices form after the collision of two spherical wave fronts from a third, trailing wave that only partially annihilates in the wake of its predecessor. Depending on the relative positions of the three relevant wave sources, one obtains untwisted or twisted s...

Finger on the pulse: in a system of two pulse-coupled Belousov-Zhabotinsky oscillators, introducing a time delay or increasing the coupling strength brings about novel dynamic features (see picture, the two oscillators are shown in different colors), such as reversal of the roles of excitatory and inhibitory coupling or fast anti-phase oscillation. These features are not observed in diffusively...