314 research outputs found
Tamanho de gotas de pontas de pulverização em diferentes condições operacionais por meio da técnica de difração do raio laser
Observational constraint on generalized Chaplygin gas model
We investigate observational constraints on the generalized Chaplygin gas
(GCG) model as the unification of dark matter and dark energy from the latest
observational data: the Union SNe Ia data, the observational Hubble data, the
SDSS baryon acoustic peak and the five-year WMAP shift parameter. It is
obtained that the best fit values of the GCG model parameters with their
confidence level are ()
, ()
. Furthermore in this model, we can see that the
evolution of equation of state (EOS) for dark energy is similar to quiessence,
and its current best-fit value is with the confidence
level .Comment: 9 pages, 5 figure
Constraining the dark energy with galaxy clusters X-ray data
The equation of state characterizing the dark energy component is constrained
by combining Chandra observations of the X-ray luminosity of galaxy clusters
with independent measurements of the baryonic matter density and the latest
measurements of the Hubble parameter as given by the HST key project. By
assuming a spatially flat scenario driven by a "quintessence" component with an
equation of state we place the following limits on the
cosmological parameters and : (i) and (1) if the
equation of state of the dark energy is restricted to the interval (\emph{usual} quintessence) and (ii) and
() if violates the null energy condition and assume values (\emph{extended} quintessence or ``phantom'' energy). These results are in
good agreement with independent studies based on supernovae observations,
large-scale structure and the anisotropies of the cosmic background radiation.Comment: 6 pages, 4 figures, LaTe
Abundances of the elements in the solar system
A review of the abundances and condensation temperatures of the elements and
their nuclides in the solar nebula and in chondritic meteorites. Abundances of
the elements in some neighboring stars are also discussed.Comment: 42 pages, 11 tables, 8 figures, chapter, In Landolt- B\"ornstein, New
Series, Vol. VI/4B, Chap. 4.4, J.E. Tr\"umper (ed.), Berlin, Heidelberg, New
York: Springer-Verlag, p. 560-63
Dermatophylosis in Santa Inês sheep from Distrito Federal
Relataram-se quatro casos de dermatofilose em ovinos da raça Santa Inês, no período de um ano. Microscopicamente observaram-se filamentos na forma de "trilho de bonde" e zoósporos nos quatro casos. A tentativa do isolamento do microrganismo foi realizada por meio do método de Haalstra e em apenas um caso obteve-se sucesso, observando-se colônias de aparência lisa, formato circular, cor amarelada e hemolítica em ágar sangue. O exame direto com coloração de Gram mostrou-se um método bastante eficiente na confirmação da presença do microrganismo afetando a epiderme em razão da morfologia típica do agente.Four cases of dermatophylosis were reported in Santa Inês sheep in a study period of one year. Microscopically, septate filaments and coccoid forms zoospores were observed. Attempts to isolate the microorganisms were accomplished using Haastra's method and it was successful in only one case. Dermatophilus congolensis samples have grown on blood agar, colonies where hemolytic, small, round and pigmentation vary from yellow to orange. The gram staining method was efficient to confirm the presence of the microorganism affecting the epidermis due to typical morphology of the agent
Cardy-Verlinde Formula and Achucarro-Ortiz Black Hole
In this paper it is shown that the entropy of the black hole horizon in the
Achucarro-Ortiz spacetime, which is the most general two-dimensional black hole
derived from the three-dimensional rotating BTZ black hole, can be described by
the Cardy-Verlinde formula. The latter is supposed to be an entropy formula of
conformal field theory in any dimension.Comment: 10 pages, LaTeX, v2: minor changes, references added, to appear in
Phys. Rev.
Bianchi Type-I Cosmological Models with Variable G and 4\Lambda$-Terms in General Relativity
Einstein's field equations with variable gravitational and cosmological
``constant'' are considered in presence of perfect fluid for Bianchi type-I
spacetime. Consequences of the four cases of the phenomenological decay of
have been discussed which are consistent with observations. The
physical significance of the cosmological models have also been discussed.Comment: 12 pages, no figur
Etiologia e quantificação dos agentes causais de manchas foliares na cultura do trigo nas safras 2008 a 2011
Parâmetros fisiológicos e desempenho para ovelhas Santa Inês e cordeiros ½ Dorper - Santa Inês nas estações verão e inverno
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