Belousov-Zhabotinsky reaction target patterns

J. J. Tyson and P. C. Fife. Target patterns in a realistic model of the Belousov-Zhabotinsky reaction. J. Chem. Phys., 73 2224, 1980. 

Tyson, J.J., K.A. Alexander, V.S. Manoranjan J.D. Murray. 1989. Spiral waves of cyclic AMP in a model of slime mold aggregation. Physica 34D 193-207. Tyson, J.J. P.C. Fife. 1980. Target patterns in a realistic model of the Belousov-Zhabotinsky reaction. J. Chem. Phys. 73 2224-37. 

Figure 1.7 Target patterns and spiral waves in the Belousov-Zhabotinsky reaction observed in a Petri dish. (Courtesy of T. Yamaguchi.)...

Pacault, A. Hanusse, P. De Kepper, P. Vidal, C. Boissonade, J. 1976. Phenomena in Homogeneous Chemical Systems far from Equilibrium, Acc. Chem. Res. 9,438-445. Pagola, A. Vidal, C. 1987. Wave Profile and Speed near the Core of a Target Pattern in the Belousov Zhabotinsky Reaction, J. Phys. Chem. 91, 501-503. 

Expanding target patterns in the Belousov-Zhabotinsky reaction were first discovered by Zaikin and Zhabotinsky (1970). In their experiment, they used a spontaneously oscillating thin layer of solution which was contained in a Petri dish of diameter 100 mm. The reagent contained bromate, bromomalonic acid and ferroin. With this prescription, one may observe periodic alternation of oxidized and reduced forms of the catalyst through a dramatic color change of the solution between red (reduced state) and blue (oxidized state). Some features of the pattern observed by them and by later experimenters are the following . ... 

Fig. 1. Target and spiral patterns of chemical waves in a thin layer (thickness, 0.7 mm) of an excitable Belousov-Zhabotinsky solution at an early (left) and a later stage (right). The reaction mixture contains CH2(COOH)2, NaBrOs, NaBr, H2SO4, and ferroin. Initial concentrations as given in [10].

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