The role of dissipation in biasing the vacuum selection in quantum field theory at finite temperature

We study the symmetry breaking pattern of an O(4) symmetric model of scalar fields, with both charged and neutral fields, interacting with a photon bath. Nagasawa and Brandenberger argued that in favourable circumstances the vacuum manifold would be reduced from S^3 to S^1. Here it is shown that a selective condensation of the neutral fields, that are not directly coupled to photons, can be achieved in the presence of a minimal ``external'' dissipation, i.e. not related to interactions with a bath. This should be relevant in the early universe or in heavy-ion collisions where dissipation occurs due to expansion.Comment: Final version to appear in Phys. Rev. D, 2 figures added, 2 new sub-section

Towards a digitally fabricated disassemble-able building system: a CNC fabricated T-Slot joint

Growing dissemination of digital fabrication technologies coupled with a renewed interest in wood as a construction material have led to a resurgence of research into integral wood joints. Recent research on digitally fabricated wood joints has focused primarily on robotic or on CNC router produced snap-fit or tab-and-slot joints. These types of joints have several problems in sheathing to structure connections. The present paper reports on research into design and fabrication of T-slot joints that allow hidden back-face connections which are disassemble-able. It is part of an ongoing research whose aim is to develop disassemble-able and mass customizable construction system of partition walls for building renovation.info:eu-repo/semantics/publishedVersio

Predicting the critical density of topological defects in O(N) scalar field theories

O(N) symmetric $\lambda \phi^4$ field theories describe many critical phenomena in the laboratory and in the early Universe. Given N and $D\leq 3$, the dimension of space, these models exhibit topological defect classical solutions that in some cases fully determine their critical behavior. For N=2, D=3 it has been observed that the defect density is seemingly a universal quantity at T_c. We prove this conjecture and show how to predict its value based on the universal critical exponents of the field theory. Analogously, for general N and D we predict the universal critical densities of domain walls and monopoles, for which no detailed thermodynamic study exists. This procedure can also be inverted, producing an algorithm for generating typical defect networks at criticality, in contrast to the canonical procedure, which applies only in the unphysical limit of infinite temperature.Comment: 4 pages, 3 figures, uses RevTex, typos in Eq.(11) and (14) correcte

Técnicas alternativas no controle de podridões pós-colheita de pêssegos.

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Propagação vegetativa de clones de umezeiro.

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Construção de cartografias de vulneraribilidade

Caracterización ambiental y análisis de riesgos en cuencas transfronterizas: proyecto piloto en el río Águeda. Custo Total 668.820,00 €A apresentação enquadra-se no âmbito do II workshop do projecto POCTEP ÁGUEDA.O projeto nasceu da necessidade de desenvolver, numa zona transfronteriça como a bacia do río Águeda, ferramentas de análise e diagnóstico ambiental para avaliação de impactes e riscos. O projeto nasceu da necessidade de desenvolver, ferramentas de análise e diagnóstico ambiental para avaliação de impactes e riscos. O ordenamento territorial sustentável permitirá planear de forma adequada todas as actividades desenvolvidas, tendo em conta os impactes e os riscos ambientais previsíveis e constituindo, desta forma, um projeto piloto para todo o eixo Luso-Espanhol. Para a sua concretização encontra-se em curso o desenvolvimento de uma plataforma metodológica de articulação territorial onde se desenvolverá uma memória descritiva que auxiliará em decisões futuras.União Europeia; FEDER

Sequential Gaussian Simulation of uranium spatial distribution : a transboundary watershed case study

Este artigo deriva de uma comunicação apresentada em International workshop “Uranium, Environment and Public Health”, UrEnv 2013.The main purpose of this work is the uranium spatial distribution patterns in groundwater, within the Águeda river transboundary watershed (Portugal-Spain). Mineral resources occur distributed throughout the watershed, mainly sulphide and uranium minerals. Sixty-five groundwater samples were analyzed. Geostatistical modeling was used, throughout conventional variography and Sequential Gaussian Simulation algorithm, to model the groundwater uranium spatial distribution. A hundred simulations, differing in their initial random-number seed, were performed. Spatial uncertainty evaluation allowed the definition of future monitoring and sampling strategies as well as the measurement of remediation possibilities. Uranium hot spots are strongly embedded in the central area (Ciudad Rodrigo)

Taste panel quality evaluation of 'Hayward' kiwifruit of different origins

In Portugal, the regions of Entre-Douro e Minho and Beira Litoral have exceptional conditions for the production of good quality kiwifruit. However, demand exceeds local supply resulting in importation of kiwifruit from Italy, Chile and New Zealand. Taste panels were run in December, May and June to study the preferences of Portuguese consumers for 'Hayward' kiwifruit. In December, a comparison was made between kiwifruit from Portugal and Italy, in May between kiwifruit from Portugal and Chile and in June between kiwifruit from Portugal, Chile and New Zealand. Attributes assessed by panellists were: appearance, texture, flavour, sweetness and acidity. The same samples were analyzed for: weight, equatorial and longitudinal diameter, firmness, soluble solids (as measured by refractometer) and titratable acidity. In May, panellists preferred Portuguese kiwifruit, but in December and June the preference was not so clear. In December, Portuguese kiwifruit were not at the eating ripe stage and in June they were at the end of their storage life (bad appearance but better flavour, sweetness and texture)