5 research outputs found
Jamming and percolation in random sequential adsorption of straight rigid rods on a two-dimensional triangular lattice
Monte Carlo simulations and finite-size scaling analysis have been performed
to study the jamming and percolation behavior of linear -mers (also known as
rods or needles) on the two-dimensional triangular lattice, considering an
isotropic RSA process on a lattice of linear dimension and periodic
boundary conditions. Extensive numerical work has been done to extend previous
studies to larger system sizes and longer -mers, which enables the
confirmation of a nonmonotonic size dependence of the percolation threshold and
the estimation of a maximum value of from which percolation would no longer
occurs. Finally, a complete analysis of critical exponents and universality
have been done, showing that the percolation phase transition involved in the
system is not affected, having the same universality class of the ordinary
random percolation.Comment: 6 figure
Memory effects in vibrated granular systems: Response properties in the generalized random sequential adsorption model
We investigate, by numerical simulation, the dynamical response of a granular
system to an abrupt change in shaking intensity within the framework of the
reversible random sequential adsorption models. We analyse the two-dimensional
lattice model in which, in addition to the adsorption-desorption process, there
is diffusion of the adsorbed particles on the surface. Our model reproduces
qualitatively the densification kinetics and the memory effects of vibrated
granular materials. An interpretation of the simulation results is provided by
the analysis of the insertion probability function. The importance of the
diffusional relaxation is discussed. We conclude that a complex time-evolution
of the density could be explained as a consequence of the variation of the
diffusion rate during the compaction. We study the nonequilibrium
time-dependent density-density autocorrelation function and show that the model
displays out-of-equilibrium dynamical effects such as aging.