Experiments on phase diffusion waves

Bodet, J. M.; Ross, John; Vidal, C.

doi:10.1063/1.452713

Cited by 28 publications

(11 citation statements)

References 15 publications

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“…Schematic representation of the experimental setup: (1) reactor, (2) Br --selective electrode, (3) diode-array spectrophotometer, (4) ion analyzer, (5) data acquisition unit, (6) tungsten-halogen lamp, (7) photomultiplier tube (PMT), (8) stirrer, (9) thermostating liquid, (10) argon gas input, (11) thermocouple,(12) computer.…”

mentioning

confidence: 99%

Reaction Mechanism for Light Sensitivity of the Ru(bpy)₃²⁺-Catalyzed Belousov−Zhabotinsky Reaction

1997

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The effects of light on the Ru(bpy) 3 2+ -catalyzed Belousov-Zhabotinsky (BZ) reaction are investigated. Experiments were carried out on an organic subset of the reaction comprised of bromomalonic acid, sulfuric acid, and Ru(bpy) 3 2+ as well as on an inorganic subset comprised of bromate, sulfuric acid, and Ru(bpy) 3 2+ . Experiments were also carried out on the full Ru(bpy) 3 2+ -catalyzed BZ system. The experiments, together with modeling studies utilizing an Oregonator scheme modified to account for the light sensitivity, show that irradiation gives rise to two separate processes: the photochemical production of bromide from bromomalonic acid and the photochemical production of bromous acid from bromate.

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confidence: 99%

Reaction Mechanism for Light Sensitivity of the Ru(bpy)₃²⁺-Catalyzed Belousov−Zhabotinsky Reaction

1997

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“…21 The features that distinguish these two types of waves are described in Ref. 22. In the calculations described in this paper we have observed both self-sustaining trigger wave patterns as well as chemical waves that evolve according to the scenario described in Ref.…”

Section: A the Homogeneous Regionmentioning

confidence: 71%

“…In the calculations described in this paper we have observed both self-sustaining trigger wave patterns as well as chemical waves that evolve according to the scenario described in Ref. 22. Below we call the persistent, self-sustaining chemical waves with sharp gradients trigger waves, while the trigger waves that decay to phase diffusion waves will be called incipient trigger waves.…”

Section: A the Homogeneous Regionmentioning

confidence: 78%

Inhomogeneous perturbations and phase resetting in an oscillatory reaction–diffusion system

Chee

Kapral

Whittington

1990

The Journal of Chemical Physics

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The response of the Brusselator reaction-diffusion system to inhomogeneous perturbations is studied. The main focus of this work is on a spatial generalization of the phase resetting problem. A randomly chosen fraction p of an initially homogeneous oscillatory system is locally perturbed and driven off the limit cycle. The asymptotic local phase is monitored and averaged over local regions and realizations of the perturbation process. From this information a phase response curve can be constructed which depends both on the local stimulus amplitude and on p. The system exhibits two qualitatively different kinds of response depending on the stimulus amplitude and the phase at which the perturbation is applied. It either relaxes to a spatially homogeneous oscillatory state or develops persistent spatial patterns. The origin of this behavior is discussed.

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“…The waves generated by such a mechanism have a tendency to vanish after some time. 4 Target waves also appear if the parameters of the pacemaker region are slightly different from the remaining part of the medium. In this paper the waves were The size of the window is j l c .…”

Section: X-xo=zs U2 A(pt)e I(0otmentioning

confidence: 98%

Propagation of target waves in the presence of obstacles

Sepulchre

Babloyantz

1991

Phys. Rev. Lett.

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The propagation of target waves in the presence of walls and windows is considered. It is shown that in a finite system, for sufficiently small passages no target waves are triggered. Propagation through a large opening can inhibit the onset of waves from smaller windows.PACS 03.40.Kf Concentric waves of chemical activity have been observed in reacting systems as well as in other media. The theoretical aspect of the problem has also drawn much attention from researchers in diverse fields. 1,2 In this paper we report numerical simulations of target waves in a reaction-diffusion medium where a partition is introduced in the system. Two openings of various size insure the communication between the two compartments. In such an environment, target waves show some unexpected behavior which is the object of this Letter.The reaction is assumed to proceed in a twodimensional square vessel in the presence of diffusion. The compartment walls are subject to "no-flux" boundary conditions. The general equation describing this system is -^=F(X)+Z>V 2 X,(1) dt where X(r,/) is a vector representing the concentration variables and D is the diffusion matrix taken here to be a multiple of the identity matrix.It is assumed that the reaction kinetics is such that for a range of parameter values a supercritical Hopf bifurcation leading to bulk oscillations takes place. Near the instability point, such a system may be reduced to a Ginzburg-Landau-type equation which characterizes the behavior of the slowly varying complex amplitude A(p,r) defined aswhere Xo describes the concentration values of a steady solution of Eq. (1) which has become unstable via the Hopf bifurcation and £ is the critical mode, i.e., the eigenvector related to the eigenvalue icoo of the Jacobian matrix of F computed at Xo. The small parameter e<£ 1 is a measure of the distance from the bifurcation point and the complex field A(p,r) evolves on the slow time scale r = et and on the large length scale p^is/D) 1/2 r. In the postcritical regime Eq. (1) gives 3 ^--nA-(g, + ig,)\A?A+\ 2 A.The real constants g r , g/, and JJ. can be related to the parameters of the model. In the case of a supercritical bifurcation, we have ,u and g r > 0. With the help of the amplitude equation (3), one shows that to the lowest order in e, the bulk frequency of the homogeneous oscillation of concentrations X is r = ft>o~" £/*£//#>• When the nonlinear dispersion g t is normal, i.e., when the period of the oscillations increases with the amplitude, then g, > 0.We first study the events in the compartment I when only one window is considered [ Figs. 1(a) and 1(b)]. In the system described by Eq. (2), target waves may be generated around centers by introducing in the system local inhomogeneities that we shall call pacemaker centers. First, traveling waves are generated under the action of a small local fluctuation in the concentration variable. The waves generated by such a mechanism have a tendency to vanish after some time. 4 Target waves also appear if the parameters of the pacemaker r...

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Experiments on phase diffusion waves

Cited by 28 publications

References 15 publications

Reaction Mechanism for Light Sensitivity of the Ru(bpy)₃²⁺-Catalyzed Belousov−Zhabotinsky Reaction

Reaction Mechanism for Light Sensitivity of the Ru(bpy)₃²⁺-Catalyzed Belousov−Zhabotinsky Reaction

Inhomogeneous perturbations and phase resetting in an oscillatory reaction–diffusion system

Propagation of target waves in the presence of obstacles

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Experiments on phase diffusion waves

Cited by 28 publications

References 15 publications

Reaction Mechanism for Light Sensitivity of the Ru(bpy)32+-Catalyzed Belousov−Zhabotinsky Reaction

Reaction Mechanism for Light Sensitivity of the Ru(bpy)32+-Catalyzed Belousov−Zhabotinsky Reaction

Inhomogeneous perturbations and phase resetting in an oscillatory reaction–diffusion system

Propagation of target waves in the presence of obstacles

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Product

Resources

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Reaction Mechanism for Light Sensitivity of the Ru(bpy)₃²⁺-Catalyzed Belousov−Zhabotinsky Reaction

Reaction Mechanism for Light Sensitivity of the Ru(bpy)₃²⁺-Catalyzed Belousov−Zhabotinsky Reaction