8,381 research outputs found
New Green-Kubo formulas for transport coefficients in hard sphere-, Langevin fluids and the likes
We present generalized Green-Kubo expressions for thermal transport
coefficients in non-conservative fluid-type systems, of the generic form,
+\int^\infty_0 dt V^{-1} \av{I_\epsilon \exp(t {\cal L})
I}_0 where is a pseudo-streaming operator. It consists of a
sum of an instantaneous transport coefficient , and a time integral
over a time correlation function in a state of thermal equilibrium between a
current and its conjugate current . This formula with
and covers vastly different systems,
such as strongly repulsive elastic interactions in hard sphere fluids, weakly
interacting Langevin fluids with dissipative and stochastic interactions
satisfying detailed balance conditions, and "the likes", defined in the text.
For conservative systems the results reduce to the standard formulas.Comment: 7 pages, no figures. Version 2: changes in the text and references
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Programas de controle das mastites causadas por microrganismos contagiosos e do ambiente
Este trabalho foi elaborado com o objetivo de apresentar os conceitos em que se baseiam os programas de controle da mastite, em uso na maioria das indústrias leiteiras desenvolvidas. Foram abordados os fundamentos dos programas de controle, as características dos patógenos mais comuns, os fatores relacionados à ocorrência da doença e a síntese do programa de controle. Destina-se prioritariamente a médicos veterinários e estudantes, embora outros profissionais e produtores interessados no tema possam também usá-lo.bitstream/item/81916/1/Programas-de-controle-das-mastites.pd
Effective models of quantum gravity induced by Planck scale modifications in the covariant quantum algebra
In this paper we introduce a modified covariant quantum algebra based in the
so-called Quesne-Tkachuk algebra. By means of a deformation procedure we arrive
at a class of higher derivative models of gravity. The study of the particle
spectra of these models reveals an equivalence with the physical content of the
well-known renormalizable and super-renormalizable higher derivative gravities.
The particle spectrum exhibits the presence of spurious complex ghosts and, in
light of this problem, we suggest an interesting interpretation in the context
of minimal length theories. Also, a discussion regarding the non-relativistic
potential energy is proposed.Comment: Small corrections were made; improved figures; results unchanged;
published versio
Asymmetrical bloch branes and the hierarchy problem
We investigate a two scalar fields split braneworld model which leads to a
possible approach to the hierarchy problem within the thick brane scenario. The
model exhibits a resulting asymmetric warp factor suitable for this purpose.
The solution is obtained by means of the orbit equation approach for a specific
value of one of the parameters. Besides, we analyze the model qualitative
behaviour for arbitrary parameters by inspecting the underlying dynamical
system defined by the equations which give rise to the braneworld model. We
finalize commenting on the metric fluctuation and stability issues.Comment: 8 pages, 7 figure
Rinite atrófica dos suínos: alternativas de controle.
bitstream/item/59363/1/CUsersPiazzonDocuments3.pd
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