Papers

A multi-analytical approach was used to study the pictorial layers of a set of 17th century historic glazed tiles (azulejos) of Portuguese manufacture. The pictorial layer was studied by ?-EDXRF, ?-Raman, SEM-EDS and OM. Although the established palette comprises few pigments, it was found that the tiles were enhanced by the use of pigment mixtures, which were identified by ?-Raman and ?-EDXRF. As expected, the blue colour derives from cobalt oxide, purple from manganese oxide and emerald-green from copper oxide. Regarding the yellow pigment, ?-Raman results show it is consistent with the composition of a ternary oxide, whereas ?-EDXRF shows a high intensity of Zn in this colour, indicating a composition close to a Pb–Sb–Zn ternary oxide. Some compounds from the original ores were also indentified: in two very dark blue samples, cobalt and nickel olivines (?-Co2SiO4, ?-Ni2SiO4), and in a dark brown sample, braunite (a manganese silicate).

Nanostructured coatings exhibit a high potential for corrosion protection of metallic materials, namely, the hybrid sol-gel coatings due to the synergic effect on the mechanical and chemical properties achieved by interconnecting organic and inorganic components. In this study, a nanostructured hybrid sol-gel coating with optimized anticorrosive properties was developed for protection of an aluminium alloy frequently used in the construction field. Its performance was assessed in different corrosive conditions, showing an effective ability to protect the alloy either individually or integrated an anticorrosive coating system usually applied in architecture, replacing the toxic Cr(VI) based pre-treatments.

As «Normas técnicas para melhoria da acessibilidade das pessoas com mobilidade condicionada» foram aprovadas pelo Decreto-Lei n.º 163/2006, de 8 de Agosto, e estabelecem um conjunto de especificações de acessibilidade a satisfazer no projeto e na construção de espaços públicos, edifícios públicos, edifícios e estabelecimentos que recebem público e edifícios de habitação. Passados seis anos após a sua entrada em vigor destas Normas técnicas, é apresentada uma análise do seu processo de elaboração. Nesta análise são salientados os principais aspetos positivos e as limitações do referido processo. Tendo como exemplo as Normas técnicas, são depois tecidas algumas considerações sobre o processo de produção e revisão dos regulamentos que enquadram a construção em Portugal.

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The vortex-induced vibration (VIV) phenomenon has drawn the attention of researchers in Engineering for several decades. An example is the riser used for petroleum exploration, in which it is subjected to marine flows that may cause oscillations due to vortex shedding. In this paper, numerical analyses of the phenomena that occur in the interaction among flows at low Reynolds numbers and elastically mounted cylinders are presented. The simulation is carried out by using the numerical model Ifeinco that uses a semi-implicit two-step Taylor-Galerkin method to discretize the Navier-Stokes equations and the arbitrary Lagrangean-Eulerian formulation to follow the cylinder motion. The rigid body motion description is calculated by using the Newmark method. Firstly, the characteristics of the vortex generation process for the fixed cylinder are analyzed. In this case, the Strouhal number, the mean drag and the RMS lift coefficients for Reynolds numbers ranging from 90 to 140 are shown. Afterwards, an analysis of a flexible supported cylinder (with a spring and a damper) in transverse direction subject to flows with Reynolds numbers ranging from 90 to 140 is carried out. The cylinder displacement and the vibration frequencies are studied; the synchronization between the vortex shedding and the vibration frequency (lock-in) is analyzed. Similar results to the experimental ones developed by Anagnostopoulos and Bearman (1992) were obtained in this study.

Vários grandes projectistas têm insistido em que a Arquitectura é, essencialmente, um jogo de relações; por exemplo, Álvaro Siza referiu-o explicitamente e houve mesmo obras teórico-práticas que foram feitas exactamente nesta perspectiva da abordagem da franja entre edificado e espaço exterior. Comenta-se que as matérias do ambiente constituem, aqui, talvez, cerca de um terço da totalidade da matéria, que se desenvolve, igualmente, pela “expressão construtiva” e pelo “refúgio do imaginário” – e sobrarão ainda outras facetas arquitectónicas nesta franja entre interior e exterior, lugar estratégico das relações que são, afinal, a própria matéria-base da Arquitectura.

Atentemos, então, agora, neste artigo e ainda globalmente, um pouco mais nas entradas das nossas casas, dos edifícios em que habitamos e, para iniciar esta reflexão de como ajudar a constituir vizinhanças coesas com edifícios habitados, coloquemos uma questão exploratória e um pouco provocatória: Será que as condições de relação directa entre as nossas casas e as nossas ruas, que caracterizaram e ainda caracterizam muitas povoações e, especialmente, muitos bairros citadinos tradicionais, não são recuperáveis em intervenções novas e de renovação urbana? E será da apurada adequação desta pequena rede de acessos que resultará boa parte da desejada vitalidade e da essencial curiosidade das respectivas vizinhanças, assim como será da estratégia da sua distribuição que resultará a prevenção do desenvolvimento de eventuais “pontos” “mortos”, inseguros e potencialmente difíceis de manter limpos e atraentes, e não tenhamos dúvida que será deste positivo jogo entre espaços urbanos e acessos a fogos que poderá resultar uma boa obra de Arquitectura e uma boa obra na aproximação à satisfação dos habitantes.

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Coastal waters are an integral part of the natural environment. Careful planning and management is needed to protect and conserve them, and to ensure that the water supply is useful for a variety of uses. Submarine outfalls for effluent disposal are used to ensure that the water quality is maintained and that the environmental values and water uses are protected. Decision on treatment and disposal is based on objectives set by national and international legislation and on coastal and maritime uses identification. An operational forecast methodology is proposed for the management of submarine outfalls providing information to deal with the marine environment problems and to satisfy needs at different levels for coastal communities. From a management perspective the forecast methodology will support decision making by predicting where a discharged plume is likely to be transported over a few days from its last known location. Short-term forecasts of maritime climate and hydrological conditions along with foreseen effluent characteristics (depending on seasons and population equivalent) of the studied region are used for an accurate estimation of the effluent plume advection and diffusion processes near the coastline. The operational forecast methodology, continuously evaluating the plume behavior and its relation with the protection perimeter (identified through a coastal usage map), allows the implementation of a precautionary and adjustable management of the submarine outfall. Corrective measures (e.g. increase dilution, increase the number of outlets, increase outflow speed) may avoid possible operational disruptions and minimize potential water quality impacts. To illustrate the application of the procedure, a submarine outfall case study located in the Portuguese coast is analysed.