Artigos de Revista

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Aquifer systems are an important part of anintegrated water resources management plan as foreseen in the European Union

Estuaries are unique systems with an unquestionable economical, ecological and recreational value which has motivated a large amount of research work. Out of the research focus emerge the estuarine margins and more particularly the estuarine beaches, especially in what concerns their macro-scale evolution. This work aims tounderstand the origin and evolution of Tagus estuary beaches. To meet this objective, a detailed geomorphological characterization of peri-estuarine margins, complemented with geological and sedimentological data, was performed. This study was coupled with the analysis of meteorological andhydrodynamic processes that control the estuarine sedimentary dynamics; particular attention was given to local waves through the application of a wind-wave generated model calibrated with field data.The origin of Tagus estuarine beaches is related with the Holocene transgression, which promoted the drowning of the present-day upper estuarine depression and generated a wide and shallow fetch-limited basin. From the transgressive maximum onwards the estuary initiated an infilling process dominated by fluvial fine-graineddeposition within the estuarine basin, whereas sand input was retained in a bay-head delta. At the same time,fetch-limited waves promoted the erosion of estuarine margins, initiating beach development, related to the growth of sand spits anchored in Plio-Pleistocene reliefs. This process depended on wave energy and also on mean wave power direction, which controlled the spit growing pattern. At present, beach evolution reflects thedisturbance of sediment budget due to the increase of human intervention in estuarine margins.

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The importance of performance assessment in the water industry is demonstrated bythe increasing number of initiatives taking place around the world. Since the firstinitiatives, which started 15 years ago, the topic has evolved significantly although itstill presents challenges to be tackled.Five years ago, a project on performance assessment of urban infrastructure serviceswas submitted to the European Union under the COST programme. As aconsequence, the COST C18 Action was created. This paper presents the mainconclusions and future key research areas from the project. In the solid waste sector,existing practical experience is less advanced, but methodologies and conclusions willbe equally applicable in performance assessment projects.

As placas de derivados de madeira apresentam-se como produtos de baixa variabilidade e relativa facilidade de manipulação das suas propriedades físicas e mecâ¢nicas, adaptando-se a aplicações como sejam revestimentos de piso, paredes e coberturas ou placas para cofragem. O termo placas de derivados de madeira abarca actualmente um largo conjunto de produtos, caracterizados por serem constituídos por elementos de madeira, um ligante e aditivos (englobando produtos hidrófugos, ignífugos e preservadores). A classificação das placas é realizada de acordo com a dimensão (fibra, partículas, folha) e a geometria dos elementos de madeira que entram na sua composição.

The knowledge of physical and mechanical characteristics of ancient mortars is very important to select repair mortars and to plan adequately any repair intervention. There is a need to define characterization test methods applicable to irregular, friable samples to assess those characteristics. In the present work some results of experimental characterization of Portuguese old mortars are presented and discussed. The test methods used to evaluate the water behaviour and the compressive resistance are described. A comparison with results of compressive strength obtained for new mortars, using the same method and also the methods proposed by EN standards, is used to extract conclusions about the method

Portugal is one of many countries in the world to suffer from coastal erosion. Conventional ways of protecting acoastline appear to entail some disadvantages. An innovative and interesting way of protecting a local coastalzone by means of multi-functional artificial reefs avoids some of them. A multi-functional artificial reef is asubmerged breakwater which protects the local coastline and may also enhance the surfing possibilities and theenvironmental value of the local area. The structure has several positive side-effects: first, it provides anunimpaired visual amenity; second, it offers tourist and economic benefits by improving the surfing. A physicaland numerical study has been undertaken to investigate the influence of the length and submergence of the reef.Preliminary conclusions on the length of the reef suggest that it should be 0.5 times the wave length at the startof the reef, and regarding the submergence they indicate that a value smaller than the offshore wave height isnecessary to get a surfable wave for a reef slope of 1:10.

Digital preservation aims at maintaining digital objectsaccessible over a long period of time, regardless of thechallenges of organizational or technological changes orfailures. In particular, data produced in e-Science domains couldbe reliably stored in today