Artigos de Revista

O artigo desenvolve uma análise sobre as homogeneidades sócio-económicoas e ambientais das zonas costeiras continentais portuguesas, explorando a exposição humana ao risco de erosão costeira e perspectivas interdisciplinares de abordagem sobre os riscos ambientais. A análise desenvolvida cruza indicadores sociais e geofísicos, embora o enfoque de partida privilegie as dimensões sócio-ecológicas dos usos e ocupações humanas do território. O artigo resume actividades concluídas no âmbito de um projecto em curso financiado pela Fundação para a Ciência e Tecnologia, tendo como objectivo principal contribuir para uma gestão integrada das zonas costeiras, desenvolver indicadores de vulnerabilidade e discutir, a propósito do risco de erosão costeira, medidas de prevenção, protecção e socorro.

Porosity and degree of saturation - or the water content - are important parameters for hydrogeological, geotechnical and environmental studies. Geophysical methods, especially the resistivity method, are routinely employed to study the spatial variations of these parameters. Resistivity is highly influenced by the presence of water in pore spaces and hence is well suited for studying the presence of fluids on a site and its saturation condition However, the non-uniqueness of the solution of resistivity models has lead to the joint use of more than one geophysical method in order to reach more accurate geophysical models. In this research work, we have decided to combine resistivity and seismic refraction profiles. The integration of these methods was particularly aimed to obtain 2D sections for estimating porosity, water saturation and volumetric water content rather than to obtain a better geophysical solution. Independently inverted resistivity and P-wave refraction sections are the input data of an iterative process using Simulated Annealing. Empirical equations from literature are used, which relate both the seismic velocity and the electrical resistivity with porosity and water saturation. Several parameters, such as resistivity of water and clay; velocity of water, clay, air and matrix; clay percentage and Archie

Within the GeoSIS_Lx project, a geotechnical data base is being implementedand methodologies to generate tridimensional geological and geotechnical models of thecity of Lisbon are being developed. The generation of the tridimensional model is beingpursued through an iterative process using a Geographical Information System (GIS) platform,designed to be open to the use of several technicians that may not be geology orsoftware experts. Geological surfaces were derived based on information interpolated fromcross-sections, resulting in a simple model where first order geological patterns are present,following a validation with the cartographic patterns of geological outcrops and with selectedinformation of the geological database. Future developments include refinement of modelingof faults and an automatic validation procedure against the borehole database and geologiccartographic patterns taking into account the data uncertainties. Results indicate that themethodology in this test suits the requisites of the geological formations of Lisbon.

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O texto discute a importância de se pensar a cidade com o imigrante

A madeira foi historicamente um dos materiais mais utilizados em caixilharia e ainda hoje é utilizada para a realização de caixilharia de elevado desempenho.

A performance assessment system (PAS) is an important instrument to provide a costeffective and sustainable management of wastewater treatment plants (WWTPs). Despite the fact that many PASs have been developed in recent years, important aspects of WWTPevaluation have not yet been considered. This paper presents the framework and the overall performance indicators of a PAS developed for urban WWTPs.

An electrochemical study of prestressed steel in saturated Ca(OH)2 aqueous solutions (pH 12) was carried out in the absence and in the presence of chloride ions, in such a concentration that simulates the composition of seawater. Cyclic voltammetry, linear sweep voltammetry, open circuit potential transients, atomic absorption spectroscopy and scanning electron microscopy coupled to electron diffraction spectroscopy were employed. The linear polarisation curves analysis led to the determination of polarisation resistance, Rp, corrosion potential, Ecorr, corrosion current density, jcorr, Tafel slopes, breakdown potential, Eb and repassivation potential Erepass. A linear dependence of the breakdown potential, Eb, on the square root of scan rate was obtained, according to the Point Defect Model (PDM). A crossover characteristic of the nucleation processes was observed in the presence of chloride ions. SEM/EDS studies revealed, as expected, a strong influence of the presence of chloride ions observed in the transpassive and the active regions. In conclusion, chloride ions contribute to enhance the corrosion of steel, most probably due to their adsorption on both the active and the passive electrode surfaces.

Tal como em muitas outras áreas, no domínio dos sistemas e serviços urbanos de água(abastecimento de água e de gestão de águas residuais) a actividade normativa desempenhaum papel importante na eliminação de barreiras técnicas ao comércio de produtos e serviços,através da uniformização de procedimentos e critérios. Também as crescentes exigências emtermos de Qualidade têm vindo a demonstrar a necessidade da existência de uma estruturanormativa adequada em que se apoiem os processos de certificação. O presente artigo tem porobjectivo fazer a apresentação da actividade de normalização em curso neste domínio levada acabo pela Comissão Técnica CT90