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Updated: Aug 13, 2026
11:03
An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
Spatiotemporal chaos and nonequilibrium transitions in a model excitable medium
1Centre for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore 560 012, India.
Summary
Boundary conditions critically affect CO oxidation on Pt(110). Periodic conditions yield a complex mixture state (MP), while Neumann conditions produce a single spiral state (MN), both transitioning differently to turbulence.
Area of Science:
- Surface chemistry
- Chemical kinetics
- Statistical mechanics
Background:
- The Bar model describes CO oxidation on Pt(110), a key catalytic reaction.
- Understanding statistical steady states is crucial for predicting reaction dynamics.
- Previous work briefly mentioned a meandering spiral state (M).
Purpose of the Study:
- Investigate the statistical steady states of the Bar model for CO oxidation on Pt(110).
- Elucidate novel properties of the meandering spiral (M) state under different boundary conditions.
- Characterize transitions between different steady states and their underlying mechanisms.
Main Methods:
- Detailed computational study of the Bar model.
- Analysis of statistical steady states under periodic and Neumann boundary conditions.
- Characterization of phase transitions between states MP, MN, S, and T1.
Main Results:
- The stability diagram is highly sensitive to boundary conditions.
- Periodic boundary conditions lead to state MP: a mix of quasiperiodic spirals and chaotic defects.
- Neumann boundary conditions result in state MN: a single quasiperiodic spiral.
- MP to turbulent (T1) transition is continuous; MN to T1 transition is discontinuous.
- Transitions to state S (quasiperiodic spirals) were characterized.
Conclusions:
- Boundary conditions fundamentally alter the dynamics of CO oxidation on Pt(110).
- The meandering spiral state exhibits distinct behaviors (MP vs. MN) based on boundary conditions.
- Qualitative mechanisms for transitions between steady states were proposed.
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