Murilo P. Almeida

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We demonstrate the difference between local, single-particle dynamics and global dynamics of entangled quantum systems coupled to independent environments. Using an all-optical experimental setup, we showed that, even when the environment-induced decay of each system is asymptotic, quantum entanglement may suddenly disappear. This "sudden death" constitutes(More)
We investigate the origin of the deviations from the classical Darcy law by numerical simulation of the Navier-Stokes equations in two-dimensional disordered porous media. We apply the Forchheimer equation as a phenomenological model to correlate the variations of the friction factor for different porosities and flow conditions. At sufficiently high(More)
We investigate fluid flow through disordered porous media by direct simulation of the Navier-Stokes equations in a two-dimensional percolation structure. We find, in contrast to the log-normal distribution for the local currents found in the analog random resistor network, that over roughly 5 orders of magnitude the distribution n͑E͒ of local kinetic energy(More)
Saltation, the motion of sand grains in a sequence of ballistic trajectories close to the ground, is a major factor for surface erosion, dune formation, and triggering of dust storms on Mars. Although this mode of sand transport has been matter of research for decades through both simulations and wind tunnel experiments under Earth and Mars conditions, it(More)
the date of receipt and acceptance should be inserted later Abstract. We use the single-histogram technique to study the critical behavior of the three-state Potts model on a (random) Voronoi-Delaunay lattice with size ranging from 250 to 8000 sites. We consider the effect of an exponential decay of the interactions with the distance, J(r) = J0 exp(−ar),(More)
Whether the winds of the present Mars are shaping the variety of dune forms observed on the Martian surface has remained an open question that challenged planetary scientists for decades. In order to elucidate this issue, we have studied sand transport and dune formation from two different points of view. The first approach consists of solving the equations(More)
The comments of Andreotti [1] are nonsense. First we do not maximize the flux, instead we calculate the saturated sand flux [2]. Thus, no " criterion " is adopted, since the value of sand flux is a result of the calculations and not an assumption. Second, the statement that our model ignores the ability of the transported grains to eject other grains ("(More)
to the information contained in the abstract submitted by the author(s). The contents of the Technical Paper, as presented, were not reviewed by IBP. The organizers are not supposed to translate or correct the submitted papers. The material as it is presented, does not necessarily represent Brazilian Petroleum, Gas and Biofuels Institute' opinion, nor that(More)