Artigos de Revista

This work intends to study the adsorption of the cyanotoxins microcystin-LR (MC-LR) and anatoxin-a(ATX-a) on a nanofiltration membrane (150 Da molar mass cut-off and an isoelectric point of 5

Mortars constituted of lime mixtures with pozzolanic additions have been extensively used in the past for the construction of historic and traditional buildings. This paper presents the results of blended pastes of lime and metakaolin (MK), namely compounds formed and their stability over time. This research is part of an extensive study aiming at the formulation of lime based mortars for restoration purposes. It has been shown for several years that MK has been applied in inorganic binders due to its capacity to react vigorously with calcium hydroxide (CH). In the presence of water originating a series of major hydrated phases, namely tetra calcium aluminate hydrate (C4AH13), calcium silicates hydrates (CSH) and calcium aluminium silicate hydrates (stratlingite – C2ASH8). Several blended pastes of lime and MK, with different substitution rates of lime by MK (wt%) were prepared and cured at a temperature of 20 ?C and relative humidity RH > 95%. The phase composition of the formed hydrated phases was determined by X-ray diffraction (XRD) and simultaneous thermal analysis (TG–DTA). The obtained results showed that lime/MK pastes compositions displayed different reaction kinetics during curing time, being the pozzolanic products content directly proportional to the substitution rate of lime by MK. Also, a relationship between the increase stratlingite content and the MK substitution rate of lime by MK was found.

As a new alternative countermeasure to protect the coastal zone and to increase the surfing possibilities in the Leirosa area ofPortugal, multifunctional artificial reefs were investigated numerically in this paper. The primary surfing parameters used in the design(i.e., breaker type, peel angle, wave height at breaking, and currents around the artificial reef) were analyzed. The reef functionalitywas also analyzed for coastal protection. Two reef geometries with different reef angles of 45 and 66° were tested, considering two designwave conditions (storm and common) and two tide levels (medium and low). Simulations show that both reef geometries are adequate forsurfing, although the reef angle of 66° is more suitable for standard surfers, and the 45° angle is more adequate for advanced/professionalsurfers. A morphodynamic study should be carried out to analyze the efficiency of the artificial surf reef for coastal protection. DOI: 10.1061/(ASCE)WW.1943-5460.0000128. © 2012 American Society of Civil Engineers.

N/A

This study aims to hindcast and analyze the storm surge associated with Xynthia, a mid-latitude depressionthat severely hit the French central part of the Bay of Biscay on the 27

O paradigma da construção de estruturas de madeira em Portugal mudou nos últimos 15 anos, com o aparecimento de grandes estruturas modernas, sobretudo de madeira lamelada colada, com formas arrojadas e grande impacto visual. Mas essa novidade e visibilidade acarretam igualmente a responsabilidade acrescida de todos os intervenientes, no sentido de garantir uma boa imagem destas realizações. O bom funcionamento, a segurança e a durabilidade das estruturas de madeira dependem de muitos fatores, designadamente de opções corretas ao nível do projeto e das soluções construtivas, do fabrico, da montagem e da manutenção.A garantia da qualidade passa pela revisão de projeto, a certificação dos produtos, a fiscalização e o controlo de qualidade do processo de construção.É também fundamental investir na formação de todos os intervenientes sobre aspetos específicos e problemas típicos das estruturas de madeira.São específicos e particularmente importantes: o dimensionamento e a pormenorização das ligações; os efeitos da humidade e variações dimensionais da madeira e os esforços de tração perpendicular às fibras, aspetos que se conjugam muitas vezes no desenvolvimen¬to de anomalias.Neste contexto, a inspeção e a monitorização das estruturas de madeira assumem um papel fundamental na deteção (e correção) atempada de situações problemáticas ou anomalias, devendo ser levadas a cabo por técnicos com conhecimento e experiência neste domínio.

Para a avaliação da perceção de medidas de minimização de ruído de tráfego rodoviário, em zonas urbanas, foram desenvolvidos no presente trabalho, dois inquéritos, um para avaliação da estrutura cognitiva dos indivíduos ao ruído de tráfego e o outro relativo à perceção das medidas de minimização de ruído. A estrutura e formulação das questões e o seu conteúdo foram baseados na pesquisa bibliografia efetuada, e em entrevistas semiestruturadas previamente realizadas. Para a sua efetivação, foi necessária uma abordagem multidisciplinar, na medida em que se utilizou conhecimentos de psicologia ambiental, estatística, acústica e de psicoacústica.

In the framework of a research project entitled

In the framework of a research project entitled

Since ancient times, it is understood that stormwater from constructed areas should bemanaged somehow. Waste and pollution transported by stormwater poses quantity andquality problems, affecting public health and the quality of the environment. Sanitationinfrastructures in urbanized regions have different development levels and the perceptionof stormwater changed considerably during the centuries and especially in recent years.Still, there is an evident worldwide heterogeneity when analyzing the lack of studies onurban stormwater conducted in some Asian or African countries.Strategies for sustainable stormwater management are needed at different decisionlevels (political, regional or local scale, for instance) but all of them need information anda clear understanding of the possibilities that are at stake as well as the main consequencesof each decision. A sound approach to stormwater management should be flexible,based on local characteristics, and should take into consideration temporal, spatialand administrative factors and law, among other issues. Economic or technical constraintsdefine different decision scenarios.Best Management Practices should be seen as an opportunity for development andimprovement of social, educational and environmental conditions in urbanized andsurrounding areas. Therefore they require an ample perspective and the participation ofdifferent stakeholders. High-quality decision needs time and a fair overview of theproblem: the purpose of this document is to contribute to sustainable stormwatermanagement, informing on the most relevant factors that should be assessed and theirinteraction. A flowchart has been produced and is presented, indicating the most relevant steps, processes and information that should be taken into account in urban development.