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It has been possible to develop a modified Oregonator model showing photoinduced behaviour in the Ru(bpy)(sub 3)(super 2+)-catalyzed Belousov-Zhabotinsky reaction. The photoinduction of oscillations is reproduced quantitatively.

A study was conducted to analyze stochastic resonance under two-parameter modulation in a framework of the photosensitive Belousov-Zhabotinsky reaction in a flow system. Two control parameters of the model were light flux and flow rate. The effect of the flow rate modulation in the system was examined from the perspective of the peristaltic effect of a pump. Results indicated that the additional flow rate modulation promoted increases and decreases in the resonance.

The photosensitive Belousov-Zhabotinsky reaction in a flow system was described using a two-parameter stochastic resonance model. The novel Oregonator-type model contains light flux and a flow rate as control parameters and treats the oscillatory behavior of the system as dynamically observable. Experimental results showed that stochastic resonance is caused by modulation of an excitable focal steady-state close to a Hopf bifurcation by a periodic signal in one parameter and noise in the other parameter.

The Belousov-Zhabotinsky (BZ) reaction is an important experimental model for the study of chemical oscillations and waves far from the thermodynamic equilibrium. Earlier studies had observed that individual BZ microbeads can show both global oscillations and traveling waves, but failed to select these different dynamic states. Here, we report experiments, in which this control was achieved by an externally applied electrical potential. The spherical microbeads were first loaded with the catalyst, then immersed into a catalyst-free BZ solution, and finally placed onto a planar platinum electrode. For positive electrical potentials, we observed global oscillations, whereas negative potentials resulted in traveling waves. The spatio-temporal characteristics of these phenomena are discussed in relation to the activator, HBrO 2 , which is produced by an electrochemical reaction.