Physics I

In this paper we present experimental results concerning Acoustic Emission (AE) recorded during cyclic compression tests on two different kinds of brittle building materials, namely concrete and basalt. The AE inter-event times were investigated through a non- extensive statistical mechanics analysis which shows that their comple- mentary cumulative probability distributions follow q-exponential laws.

The equivalence between canonical and microcanonical ensembles (describing systems with soft and hard constraints respectively) is a basic assumption in statistical physics, traditionally verified through the vanishing of the relative fluctuations of the constraints in the thermodynamic limit. However, evidence has accumulated that, in presence of phase transitions or long-range interactions, this property will break down, a phenomenon known as ensemble nonequivalence.

The aim of this work is the elaboration of a methodology for the quantitative characterization of the complexity of nanostructured surfaces in order to provide novel means to link nanostructure morphology to surface properties and functionalities. The key point is the distinction of complexity from randomness contrary to the usual approaches in nanometrology. The inspiration is based on the work of R. Alamino [1] where the notion of the average symmetry is proposed to put on the same footing full order and full randomness.

The constituents of a complex system exchange information to function properly. Their signalling dynamics often leads to the appearance of emergent phenomena, such as phase transitions and collective behaviors. While information exchange has been widely modeled by means of distinct spreading processes - such as continuous-time diffusion, random walks, synchronization and consensus - on top of complex networks, a unified and physically-grounded framework to study information dynamics and gain insights about the macroscopic effects of microscopic interactions, is still eluding us.