10,773 research outputs found
Desenvolvimento de metodologias de RMN on-line de baixa potência para análise da qualidade do óleo em sementes intactas.
Non-nequilibrium model on Apollonian networks
We investigate the Majority-Vote Model with two states () and a noise
on Apollonian networks. The main result found here is the presence of the
phase transition as a function of the noise parameter . We also studies de
effect of redirecting a fraction of the links of the network. By means of
Monte Carlo simulations, we obtained the exponent ratio ,
, and for several values of rewiring probability . The
critical noise was determined and also was calculated. The
effective dimensionality of the system was observed to be independent on ,
and the value is observed for these networks. Previous
results on the Ising model in Apollonian Networks have reported no presence of
a phase transition. Therefore, the results present here demonstrate that the
Majority-Vote Model belongs to a different universality class as the
equilibrium Ising Model on Apollonian Network.Comment: 5 pages, 5 figure
Desenvolvimento de uma técnica de RMN de baixa potência para análise da qualidade de óleo em sementes intactas
Efficient formalism for large scale ab initio molecular dynamics based on time-dependent density functional theory
A new "on the fly" method to perform Born-Oppenheimer ab initio molecular
dynamics (AIMD) is presented. Inspired by Ehrenfest dynamics in time-dependent
density functional theory, the electronic orbitals are evolved by a
Schroedinger-like equation, where the orbital time derivative is multiplied by
a parameter. This parameter controls the time scale of the fictitious
electronic motion and speeds up the calculations with respect to standard
Ehrenfest dynamics. In contrast to other methods, wave function orthogonality
needs not be imposed as it is automatically preserved, which is of paramount
relevance for large scale AIMD simulations.Comment: 5 pages, 3 color figures, revtex4 packag
Rapid determination of food quality using steady state free precession sequences in TD-NMR spectroscopy.
bitstream/item/180768/1/Rapid-determination-of-food-quality-using-steady-state-free-precession-sequences-in-TD-NMR-spectroscopy..pd
Imaging the postoperative patient: long-term complications of gastrointestinal surgery
The objectives of this review are (1) to become acquainted with the long-term complications of surgery of the gastrointestinal tract, and (2) to appreciate the appropriate use of imaging in the assessment of long-term complications
Invasion Percolation Between two Sites
We investigate the process of invasion percolation between two sites
(injection and extraction sites) separated by a distance r in two-dimensional
lattices of size L. Our results for the non-trapping invasion percolation model
indicate that the statistics of the mass of invaded clusters is significantly
dependent on the local occupation probability (pressure) Pe at the extraction
site. For Pe=0, we show that the mass distribution of invaded clusters P(M)
follows a power-law P(M) ~ M^{-\alpha} for intermediate values of the mass M,
with an exponent \alpha=1.39. When the local pressure is set to Pe=Pc, where Pc
corresponds to the site percolation threshold of the lattice topology, the
distribution P(M) still displays a scaling region, but with an exponent
\alpha=1.02. This last behavior is consistent with previous results for the
cluster statistics in standard percolation. In spite of these discrepancies,
the results of our simulations indicate that the fractal dimension of the
invaded cluster does not depends significantly on the local pressure Pe and it
is consistent with the fractal dimension values reported for standard invasion
percolation. Finally, we perform extensive numerical simulations to determine
the effect of the lattice borders on the statistics of the invaded clusters and
also to characterize the self-organized critical behavior of the invasion
percolation process.Comment: 7 pages, 11 figures, submited for PR
Espaçamento de plantio de maracujá sob dois sistemas de irrigação localizada.
bitstream/item/72656/1/CPAMN-PESQ.-AND.-13-91.pd
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