Artigos de Revista

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.

N/A

N/A

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

N/A

The use of adhesives to produce assembled structural joints in the building industry is increasing, particularly in the context of on-site rehabilitation of timber structures. On their own or together with steel or fibre reinforced polymer composite connecting materials, adhesives can provide low intrusive, fast, versatileand effective on-site repair or reinforcement interventions to timber structures. Most common applicationsinvolve sealing and repair of cracks, drying fissures and delamination of glued laminated members; replacement of decayed beam ends; strengthening of timber members; and repair and strengthening of mechanical timber joints. The performance of bonded joints highly depends on their design and detailing, surfaces preparation, selection and application of adhesives, and full compliance with their cure schedule. Therefore, the work should be carried out by well-informed, trained and certified operators following a QualityAssurance Program to ensure satisfactory end-product strength and durability.Despite some recent developments, the exploitation of the full potential for on-site bonded joints is mainlyrestrained at present by the lack of structural design guidance, standards for durability assessment and onsiteacceptance testing.This article discusses briefly the use of adhesives on the construction site in the context of structural repair and reinforcement; the requirements and practical difficulties in the work on site with regards to the strength and durability of the rehabilitated timber structure; and the consequent need for quality control. It also highlights the characteristics and requirements that must be fulfilled by structural adhesives and reinforcingmaterials; factors affecting performance and durability of bonded joints; and ways to improve adhesion and durability. Finally, it points out some research needs and future developments identified by the authors.© Koninklijke Brill NV, Leiden, 2010