Hawking radiation for non asymptotically flat dilatonic black holes using gravitational anomaly

The $d$-dimensional scalar field action may be reduced, in the background geometry of a black hole, to a 2-dimensional effective action. In the near horizon region, it appears a gravitational anomaly: the energy-momentum tensor of the scalar field is not conserved anymore. This anomaly is removed by introducing a term related to the Hawking temperature of the black hole. Even if the temperature term introduced is not covariant, a gauge transformation may restore the covariance. We apply this method to compute the temperature of the black hole of the dilatonic non asymptotically flat black holes. We compare the results with those obtained through other methods.Comment: Latex file, 22 pages. Some discussions enlarged. New references. Accepted for publication in the European Physical Journal

Local entropic effects of polymers grafted to soft interfaces

In this paper, we study the equilibrium properties of polymer chains end-tethered to a fluid membrane. The loss of conformational entropy of the polymer results in an inhomogeneous pressure field that we calculate for gaussian chains. We estimate the effects of excluded volume through a relation between pressure and concentration. Under the polymer pressure, a soft surface will deform. We calculate the deformation profile for a fluid membrane and show that close to the grafting point, this profile assumes a cone-like shape, independently of the boundary conditions. Interactions between different polymers are also mediated by the membrane deformation. This pair-additive potential is attractive for chains grafted on the same side of the membrane and repulsive otherwise.Comment: 10 pages, 9 figure

Scattering from Solutions of Star Polymers

We calculate the scattering intensity of dilute and semi-dilute solutions of star polymers. The star conformation is described by a model introduced by Daoud and Cotton. In this model, a single star is regarded as a spherical region of a semi-dilute polymer solution with a local, position dependent screening length. For high enough concentrations, the outer sections of the arms overlap and build a semi-dilute solution (a sea of blobs) where the inner parts of the actual stars are embedded. The scattering function is evaluated following a method introduced by Auvray and de Gennes. In the dilute regime there are three regions in the scattering function: the Guinier region (low wave vectors, q R << 1) from where the radius of the star can be extracted; the intermediate region (1 << q R << f^(2/5)) that carries the signature of the form factor of a star with f arms: I(q) ~ q^(-10/3); and a high wavevector zone (q R >> f^(2/5)) where the local swollen structure of the polymers gives rise to the usual q^(-5/3) decay. In the semi-dilute regime the different stars interact strongly, and the scattered intensity acquires two new features: a liquid peak that develops at a reciprocal position corresponding to the star-star distances; and a new large wavevector contribution of the form q^(-5/3) originating from the sea of blobs.Comment: REVTeX, 12 pages, 4 eps figure

Portugal gestual : a importância do utilizador na criação da interface

Para o estudo da criação gráfica de uma interface de tradução entre a Língua Gestual Portuguesa e a Língua Portuguesa, é primordial considerar o utilizador. Centrar o design no Surdo [1] e identificar as lacunas existentes nos espaços públicos comunicacionais são os objetivos deste artigo. Embora, nas últimas décadas, se tenha vindo a registar o reconhecimento dos direitos dos Surdos, oficialmente com a promulgação de leis, os resultados deste estudo apontam para a persistência de um fosso entre os princípios e as práticas. Em síntese, falta reconhecer que a “deficiência” pode estar na sociedade por esta não querer, não poder ou não saber organizar-se no sentido de se incrementar como inclusiva.ABSTRACT: In order to study the graphic creation of a interface for translation between the Portuguese sign language and the Portuguese language, it is essential to consider the user. The main purpose of this article is to centre the design around the deaf and identify the existing gaps in the public communication spaces. Although in the past decades there has been a growing acknowledgement of the rights of the Deaf through the promulgation of Laws, the results from this study point to the persistence of a gap between the principles and what is, in facts, practiced. In conclusion, it is necessary to acknowledge that the "handicap" may lay in society because it either does no want, can not or does not know how to organize itself in the sense of increasing the inclusion.info:eu-repo/semantics/publishedVersio

Robotic deployment of stabilized shearography unit for wind turbine blade inspection

A wind turbine blade inspection system called Winspector has been developed by a European consortium to automate the in-situ non-destructive testing of wind blades. A robot platform is winched up a wind turbine tower to reach a blade locked into a 90-degree pitch angle. The blade region to be inspected is reached by a combination of an extension ladder and a 5-axis robot arm to place an end-effector onto the blade surface. The end-effector is critical to the success of the shearography technique used to detect subsurface defects when the blade is experiencing inevitable out-of-plane, in-plane, and root-to-tip vi-brations. The paper describes the development of the end-effector which carries the shearography unit and ensures (with passive compliance and design based on analysis of aerodynamic blade shapes) that the unit remains at a constant distance from blade surface in the presence of blade vibrations. The system has been tested with three separate field trials in a wind farm near Athens in Greece. Sub-surface defect detection with shearography has been successfully demon-strated