4,073 research outputs found
Evidence of strong dynamic core excitation in C resonant break-up
The resonant break-up of C on protons measured at RIKEN [Phys. Lett. B
660, 320 (2008)] is analyzed in terms of a valence-core model for C
including possible core excitations. The analysis of the angular distribution
of a prominent peak appearing in the relative-energy spectrum could be well
described with this model and is consistent with the previous assignment of
for this state. Inclusion of core-excitation effects are found to be
essential to give the correct magnitude of the cross section for this state. By
contrast, the calculation assuming an inert C core is found to largely
underestimate the data.Comment: 5 pages, 2 figures, to be submitte
The continuum description with pseudo-state wave functions
Benchmark calculations are performed aiming to test the use of two different
pseudo-state bases on the the Multiple Scattering expansion of the total
Transition amplitude (MST) scattering framework. Calculated differential cross
sections for p-6He inelastic scattering at 717 MeV/u show a good agreement
between the observables calculated in the two bases. This result gives extra
confidence on the pseudo-state representation of continuum states to describe
inelastic/breakup scattering.Comment: 4 pages, 2 figures. Published in Physical Review
Time as a limited resource: Communication Strategy in Mobile Phone Networks
We used a large database of 9 billion calls from 20 million mobile users to
examine the relationships between aggregated time spent on the phone, personal
network size, tie strength and the way in which users distributed their limited
time across their network (disparity). Compared to those with smaller networks,
those with large networks did not devote proportionally more time to
communication and had on average weaker ties (as measured by time spent
communicating). Further, there were not substantially different levels of
disparity between individuals, in that mobile users tend to distribute their
time very unevenly across their network, with a large proportion of calls going
to a small number of individuals. Together, these results suggest that there
are time constraints which limit tie strength in large personal networks, and
that even high levels of mobile communication do not fundamentally alter the
disparity of time allocation across networks.Comment: 10 pages, 3 figures. Accepted for publication in Social Network
Produção animal e meio ambiente: o caso TAC da suinocultura em Santa Catarina.
Projeto/Plano de Ação: 03.06.05.020
Hybrid method for simulating front propagation in reaction-diffusion systems
We study the propagation of pulled fronts in the
microscopic reaction-diffusion process using Monte Carlo (MC) simulations. In
the mean field approximation the process is described by the deterministic
Fisher-Kolmogorov-Petrovsky-Piscounov (FKPP) equation. In particular we
concentrate on the corrections to the deterministic behavior due to the number
of particles per site . By means of a new hybrid simulation scheme, we
manage to reach large macroscopic values of which allows us to show
the importance in the dynamics of microscopic pulled fronts of the interplay of
microscopic fluctuations and their macroscopic relaxation.Comment: 5 pages, 4 figure
- …