We study a two-dimensional granular gas of inelastic spheres subject to multiplicative driving proportional to a power |v(x)|(delta) of the local particle velocity v(x). The steady state properties of the model are examined for different values of delta, and compared with the homogeneous case delta = 0. A driving linearly proportional to v(x) seems to reproduce some experimental observations which could not be reproduced by a homogeneous driving. Furthermore, we obtain that the system can be homogenized even for strong dissipation, if a driving inversely proportional to the velocity is used.

New theoretical and numerical analysis of the one-dimensional contact process with quenched disorder are presented. We derive new scaling relations, different from their counterparts in the pure model, which are valid not only at the critical point but also away from it due to the presence of generic scale invariance. All the proposed scaling laws are verified in numerical simulations. In addition we map the disordered contact process into a Non-Markovian contact process by using the so called Run Time Statistic, and write down the associated field theory. This turns out to be in the same universality class as one derived by Janssen for the quenched system with a Gaussian distribution of impurities. Our findings here support the lack of universality suggested by the field theoretical analysis: generic power-law behaviors are obtained, evidence is shown of the absence of a characteristic time away from the critical point, and the absence of universality is put forward. The intermediate sublinear regime predicted by Bramsom et al. is also found. 05.50.+q,02.50

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We study a two-dimensional gas of inelastic rough spheres, driven on the rotational degrees of freedom. Numerical simulations are compared to mean-field (MF) predictions with surprisingly good agreement for strong coupling of rotational and translational degrees of freedom -even for very strong dissipation in the translational degrees. Although the system is spatially homogeneous, the rotational velocity distribution is essentially Maxwellian. Surprisingly, the distribution of tangential velocities is strongly deviating from a Maxwellian. An interpretation of these results is proposed, as well as a setup for an experiment.