Logarithmic relaxation due to minimization of interactions in the Burridge-Knopoff model

Contains fulltext : 35676.pdf (publisher's version ) (Open Access)The time evolution of macroscopic quantities describing the relaxation of complex systems often contains a domain with logarithmic time dependence. This logarithmic behavior at the macroscopic level is often associated with strongly interacting elements at the microscopic level, whose interactions depend significantly on their history. In this paper we show that stress relaxation in the Burridge-Knopoff (BK) model of multicontact friction behaves logarithmically, when the model is in, or close to, the solitary state where the elements move independently. For this regime we present an automaton that allows us to follow the decay of stress relaxation over the entire range where it behaves logarithmically in time. We show that our model can be mapped onto a system of noninteracting elements subject to a uniform distribution of forces, for which logarithmic stress relaxation is derived analytically

Transition to strictly solitary motion in the Burridge-Knopoff model of multicontact friction

Contains fulltext : 33115.pdf (publisher's version ) (Open Access

Influence of latent heat and thermal diffusion on the growth of nematic liquid crystal nuclei

Contains fulltext : 34630.pdf (publisher's version ) (Open Access

Phase transition to bundles of flexible supramolecular polymers

Contains fulltext : 36310.pdf (preprint version ) (Closed access)We report Monte Carlo simulations of the self-assembly of supramolecular polymers based on a model of patchy particles. We find a first-order phase transition, characterized by hysteresis and nucleation, toward a solid bundle of polymers, of length much greater than the average gas phase length. We argue that the bundling transition is the supramolecular equivalent of the sublimation transition, that results from a weak chain-chain interaction. We provide a qualitative equation of state that gives physical insight beyond the specific values of the parameters used in our simulations.4704 p