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 $\mu$ in non-conservative fluid-type systems, of the generic form, $\mu$ $= \mu_\infty$ +\int^\infty_0 dt V^{-1} \av{I_\epsilon \exp(t {\cal L}) I}_0 where $\exp(t{\cal L})$ is a pseudo-streaming operator. It consists of a sum of an instantaneous transport coefficient $\mu_\infty$, and a time integral over a time correlation function in a state of thermal equilibrium between a current $I$ and its conjugate current $I_\epsilon$. This formula with $\mu_\infty \neq 0$ and $I_\epsilon \neq I$ 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 adde

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