2,277 research outputs found
Mecanismos de transmissão e resistência dos principais vírus causadores de doenças em suínos.
bitstream/item/85334/1/DCOT-305.pd
Influenza em Suínos: situação brasileira e mundial.
Projeto/Plano de Ação: 02.11.01.006
The Purple Haze of Eta Carinae: Binary-Induced Variability?
Asymmetric variability in ultraviolet images of the Homunculus obtained with
the Advanced Camera for Surveys/High Resolution Camera on the Hubble Space
Telescope suggests that Eta Carinae is indeed a binary system. Images obtained
before, during, and after the recent ``spectroscopic event'' in 2003.5 show
alternating patterns of bright spots and shadows on opposite sides of the star
before and after the event, providing a strong geometric argument for an
azimuthally-evolving, asymmetric UV radiation field as one might predict in
some binary models. The simplest interpretation of these UV images, where
excess UV escapes from the secondary star in the direction away from the
primary, places the major axis of the eccentric orbit roughly perpendicular to
our line of sight, sharing the same equatorial plane as the Homunculus, and
with apastron for the hot secondary star oriented toward the southwest of the
primary. However, other orbital orientations may be allowed with more
complicated geometries. Selective UV illumination of the wind and ejecta may be
partly responsible for line profile variations seen in spectra. The brightness
asymmetries cannot be explained plausibly with delays due to light travel time
alone, so a single-star model would require a seriously asymmetric shell
ejection.Comment: 8 pages, fig 1 in color, accepted by ApJ Letter
Mumificaçao fetal em suínos associada à toxoplasmose.
bitstream/item/58346/1/CUsersPiazzonDocuments271.pd
A nonequilibrium renormalization group approach to turbulent reheating
We use nonequilibrium renormalization group (RG) techniques to analyze the
thermalization process in quantum field theory, and by extension reheating
after inflation. Even if at a high scale the theory is described by a
non-dissipative theory, the RG running induces nontrivial
noise and dissipation. For long wavelength, slowly varying field
configurations, the noise and dissipation are white and ohmic, respectively.
The theory will then tend to thermalize to an effective temperature given by
the fluctuation-dissipation theorem.Comment: 8 pages, 2 figures; to appear in J. Phys. A; more detailed account of
the calculation of the noise and dissipation kernel
Diagnóstico da síndrome multisistêmica do definhamento do leitao desmamado (SMDLD) no Brasil causada pelo circovírus suíno Tipo 2.
bitstream/item/58347/1/CUsersPiazzonDocuments270.pd
Kinetic-controlled hydrodynamics for multilane traffic models
We study the application of a recently introduced hierarchical description of
traffic flow control by driver-assist vehicles to include lane changing
dynamics. Lane-dependent feedback control strategies are implemented at the
level of vehicles and the aggregate trends are studied by means of
Boltzmann-type equations determining three different hydrodynamics based on the
lane switching frequency. System of first order macroscopic equations
describing the evolution of densities along the lanes are then consistently
determined through a suitable closured strategy. Numerical examples are then
presented to illustrate the features of the proposed hierarchical approach
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