Control of spatiotemporal chaos is one the central problems nonlinear dynamics. We report on suppression chemical turbulence by global delayed feedback using, as an example, catalytic carbon monoxide oxidation a platinum (110) single-crystal surface and partial pressure controlled variable. When intensity was increased, spiral-wave transformed into new intermittent chaotic regimes with cascades reproducing annihilating local structures background uniform oscillations. The further led to...

Stainless steels undergo a sharp rise in pitting corrosion rate as the potential, solution concentration, or temperature is changed only slightly. We report experiments using real-time microscopic situ visualizations that resolve nucleation and evolution of individual pits during transition. They suggest sudden onset explained by an explosive autocatalytic growth number metastable stabilization takes place later. This finding agrees with theoretical approach treating cooperative critical...

Winfree turbulence of scroll waves is a special kind spatiotemporal chaos that exists exclusively in three-dimensional excitable media and currently considered one the principal mechanisms cardiac fibrillation. A chaotic wave pattern develops through negative-tension instability vortex filaments, which tend to spontaneously stretch, bend, loop, produce an expanding tangle fills up volume. We demonstrate such can readily be controlled by weak nonresonant modulation medium excitability....

A bifurcation leading to the onset of translational motion localized particlelike structures (spots) in two-dimensional excitable media with long-range inhibition and global coupling is analytically numerically investigated. Properties slowly traveling spots effects collisions between these objects are studied.

The cytoplasm and biomembranes in biological cells contain large numbers of proteins that cyclically change their shapes. They are molecular machines can function as motors or carry out various other tasks the cell. Many enzymes also undergo conformational changes within turnover cycles. We analyze advection effects nonthermal fluctuating hydrodynamic flows induced by active have on passive molecules solution membranes. show diffusion constants particles enhanced substantially. Furthermore,...

We consider a model of active Brownian agents interacting via harmonic attractive potential in two-dimensional system the presence noise. By numerical simulations, we show that this possesses noise-induced transition characterized by breakdown translational motion and onset swarm rotation as noise intensity is increased. Statistical properties dynamics weak limit are further analytically investigated.

A mesoscopic description of surface chemical reactions, aimed to provide a link between microscopic lattice models and reaction−diffusion equations, is formulated. Such needed when large populations nanoscale structures are considered or patterns characterized by combination macroscopic lengths investigated. By using the example an adsorbate with attractive lateral interactions molecules, evolution equation for fluctuating coverages derived from master respective kinetic model. This...

We consider swarms formed by populations of self-propelled particles with attractive long-range interactions. These represent multistable dynamical systems and can be found either in coherent traveling states or an incoherent oscillatory state where translational motion the entire swarm is absent. Under increasing noise intensity, destroyed abrupt transition to takes place.

We introduce and study systems of randomly coupled maps where the relevant parameter is degree connectivity in system. Global (almost-) synchronized states are found (equivalent to synchronization observed globally maps) until a certain critical threshold for reached. further show that not only average connectivity, but also architecture couplings responsible cluster structure observed. analyze different phases system use various correlation measures order detect ordered nonsynchronized...

Standing waves are a special type of spatio-temporal pattern observed in the CO oxidation reaction on Pt(110). We present new experimental data that indicate important role played by formation subsurface oxygen. The these patterns is correlated with reflective collisions traveling have previously been found same reaction. also show global coupling through gas phase and external forcing essential for stabilizing synchronizing standing wave patterns. principal properties reproduced numerical...

Experiments with catalytic oxidation of carbon monoxide on Pt(110) show that chemical turbulence in this system can be suppressed by application appropriate global delayed feedback. Different spatiotemporal patterns, seen near the transition from to uniform oscillations, are investigated. Such patterns include intermittent turbulence, oscillatory standing waves, cellular structures, and phase clusters. Using a method based Hilbert transform, spatial distributions local amplitude these...

The evolution of spiral waves on a circular domain and spherical surface is studied by numerical integration reaction-diffusion system with global feedback. It shown that depending intensity, sign, and/or time delay in the feedback loop coupling can be effectively used either to stabilize rigid rotation wave or completely destroy suppress self-sustained activity confined an excitable medium. An explanation numerically observed effects produced kinematical model propagation.

Entrainment by a pacemaker, representing an element with higher frequency, is numerically investigated for several classes of random networks which consist identical phase oscillators. We find that the entrainment frequency window network decreases exponentially its depth, defined as mean forward distance elements from pacemaker. Effectively, only shallow can thus exhibit locking to The exponential dependence also derived analytically approximation large asymmetric networks.