When DNA molecules are heated they undergo a denaturation transition by which the two strands of the molecule are separated and become unbound. Experimental studies strongly indicate that the denaturation transition is first order. The main theoretical approach to study this transition,...

First-order phase transitions in finite systems can be defined through the bimodality of the distribution of the order parameter. This definition is equivalent to the one based on the inverted curvature of the thermodynamic potential. Moreover we show that it is in a one-to-one correspondence...

The relation between thermodynamic phase transitions in classical systems and topology changes in their state space is discussed for systems in which equivalence of statistical ensembles does not hold. As an example, the spherical model with mean field-type interactions is considered. Exact...

More investigated situations in the field of traffic modelling are those of traffic bottlenecks caused by slow vehicles or road defects. The new aspect of this paper is the simulation of vehicular dynamics near a partial reduction in a road from two lanes to one lane. In order to reduce the bad...

Very dense bidimensional systems of inelastic hard disks excited from the base are studied by means of Newtonian event driven molecular dynamics. A stationary regime is reached where almost perfect crystallographic order is present in the system. When the energy injection is varied in a wide...

In this work we analyze a simple model of adsorption-induced surface reconstruction, which is developed in the framework of the lattice gas model. The critical behavior of the substrate atoms is obtained by monitoring the specific heat and the fluctuations in the fraction of unreconstructed...

In the standard minority game, each agent in the minority group receives the same payoff regardless of the size of the minority group. Of great interest for real social and biological systems are cases in which the payoffs to members of the minority group depend on the size of the minority...

In spite of the intricacy of its phase diagram, a pertinent investigation of bismuth at high pressure is possible with the help of a model-potential, if perturbation expansion is extended up to third order, as evidenced by the calculations presented here (phonon spectrum of phase I, prediction...

The specific Gibbs free energy has been calculated for the infinite range Ising model with fixed and finite interaction strength. The model shows a temperature driven first-order phase transition that differs from the infinite ranged Ising model with weak coupling. In the temperature-field phase...

Making use of the Rugh's micro-canonical approach to temperature we study XY-spin systems by the strictly energy conserving over-relaxation algorithm. In this micro-canonical simulation the temperature and also the specific heat are determined as averages of expressions easy to implement. The...