No abstract

No abstract

Experiments were carried out using a tensile testing machine to study the morphology of rupture lines in paper. Constant velocity strain was applied until the breaking process separated the sample into two pieces. The resulting quasi one-dimensional patterns show scaling correlations usually over two orders of magnitudes. The measured values of the Hurst exponent ζ are in the range 0.63 < ζ < 0.72. The relevance of models of statistical physics in the interpretation of the results is discussed.

Finger on the pulse: in a system of two pulse-coupled Belousov-Zhabotinsky oscillators, introducing a time delay or increasing the coupling strength brings about novel dynamic features (see picture, the two oscillators are shown in different colors), such as reversal of the roles of excitatory and inhibitory coupling or fast anti-phase oscillation. These features are not observed in diffusively coupled systems, and shed light on how such pulse coupling occurs at synapses.