32,855 research outputs found
Coarse graining scale and effectiveness of hydrodynamic modeling
Some basic questions about the hydrodynamical approach to relativistic heavy
ion collisions are discussed aiming to clarify how far we can go with such an
approach to extract useful information on the properties and dynamics of the
QCD matter created. We emphasize the importance of the coarse-graining scale
required for the hydrodynamic modeling which determines the space-time
resolution and the associated limitations of collective flow observables. We
show that certain kinds of observables can indicate the degree of inhomogeneity
of the initial condition under less stringent condition than the local thermal
equilibrium subjected to the coarse-graining scale compatible to the scenario.Comment: 12 pages, 4 figures, Quark Matter 201
Wannier-based calculation of the orbital magnetization in crystals
We present a first-principles scheme that allows the orbital magnetization of
a magnetic crystal to be evaluated accurately and efficiently even in the
presence of complex Fermi surfaces. Starting from an initial
electronic-structure calculation with a coarse ab initio k-point mesh,
maximally localized Wannier functions are constructed and used to interpolate
the necessary k-space quantities on a fine mesh, in parallel to a
previously-developed formalism for the anomalous Hall conductivity [X.Wang, J.
Yates, I. Souza, and D. Vanderbilt, Phys. Rev. B 74, 195118 (2006)]. We
formulate our new approach in a manifestly gauge-invariant manner, expressing
the orbital magnetization in terms of traces over matrices in Wannier space.
Since only a few (e.g., of the order of 20) Wannier functions are typically
needed to describe the occupied and partially occupied bands, these Wannier
matrices are small, which makes the interpolation itself very efficient. The
method has been used to calculate the orbital magnetization of bcc Fe, hcp Co,
and fcc Ni. Unlike an approximate calculation based on integrating orbital
currents inside atomic spheres, our results nicely reproduce the experimentally
measured ordering of the orbital magnetization in these three materials.Comment: 13 pages, 3 figures, 4 table
Uso de equipamentos de proteção individual na pulverização de videiras.
bitstream/CNPUV/8816/1/cir067.pd
Torsion-Adding and Asymptotic Winding Number for Periodic Window Sequences
In parameter space of nonlinear dynamical systems, windows of periodic states
are aligned following routes of period-adding configuring periodic window
sequences. In state space of driven nonlinear oscillators, we determine the
torsion associated with the periodic states and identify regions of uniform
torsion in the window sequences. Moreover, we find that the measured of torsion
differs by a constant between successive windows in periodic window sequences.
We call this phenomenon as torsion-adding. Finally, combining the torsion and
the period adding rules, we deduce a general rule to obtain the asymptotic
winding number in the accumulation limit of such periodic window sequences
Resposta da cultivar BRS Clara ao manejo da copa e do cacho.
A cultivar de uva apirênica BRS Clara, lançada em 2003, é produzida em diferentes regiões do paÃs. As principais recomendações para cultivo da mesma foram relatadas por Camargo et al. (2003), em comunicado técnico para a variedade. Entretanto, alguns problemas, os quais desestimulam o aumento da área de produção com essa cultivar, têm sido relatados por produtores oriundos de diferentes regiões. Um dos principais problemas refere-se aos sintomas similares aos apresentados na Figura 1A, onde se pode observar o cacho com bagas manchadas, caracterizadas por estrias areoladas que surgem a partir da extremidade da baga no perÃodo final de maturação, contrastando com cachos de tamanho e coloração adequados, com bagas com altos teores de açúcar (Figura 1B). Essas manchas são respostas fisiológicas da planta, à s vezes decorrentes de desequilÃbrios nutricionais, mas que, normalmente, têm como causas principais o excesso de carga e a desfolha acentuada, devido ao tratamento fitossanitário inadequado.bitstream/item/31555/1/cot099.pd
Effect of nucleon exchange on projectile multifragmentation in the reactions of 28Si + 112Sn and 124Sn at 30 and 50 MeV/nucleon
Multifragmentation of quasiprojectiles was studied in reactions of 28Si beam
with 112Sn and 124Sn targets at projectile energies 30 and 50 MeV/nucleon. The
quasiprojectile observables were reconstructed using isotopically identified
charged particles with Z_f <= 5 detected at forward angles. The nucleon
exchange between projectile and target was investigated using isospin and
excitation energy of reconstructed quasiprojectile. For events with total
reconstructed charge equal to the charge of the beam (Z_tot = 14) the influence
of beam energy and target isospin on neutron transfer was studied in detail.
Simulations employing subsequently model of deep inelastic transfer,
statistical model of multifragmentation and software replica of FAUST detector
array were carried out. A concept of deep inelastic transfer provides good
description of production of highly excited quasiprojectiles. The isospin and
excitation energy of quasiprojectile were described with good overall
agreement. The fragment multiplicity, charge and isospin were reproduced
satisfactorily. The range of contributing impact parameters was determined
using backtracing procedure.Comment: 11 pages, 8 Postscript figures, LaTeX, to appear in Phys. Rev. C (
Dec 2000
- …