Artigos de Revista

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A flexible 2D/3D oil spill modeling system addressing the distinct nature of the surface and water columnfluids, major oil weathering and improved retention/reposition processes in coastal zones is presented.The system integrates hydrodynamic, transport and oil weathering modules, which can be combinedto offer different-complexity descriptions as required by applications across the river-to-ocean continuum.Features include accounting for different composition and reology in the surface and water columnmixtures, as well as spreading, evaporation, water-in-oil emulsification, shoreline retention, dispersionand dissolution. The use of unstructured grids provides flexibility and efficiency in handling spills in complexgeometries and across scales. The use of high-order Eulerian

A numerical model for analysis of masonry gravity dams based on the Discrete Element Method is presented.The dam and the rock foundation are represented as block assemblies, using elementary 3- and 4-node blocks. Complex block shapes are obtained by assembling the elementary blocks into macroblocks,allowing the model to be applied in various situations ranging from equivalent continuum to fully discontinuumanalysis. A contact formulation was developed, which represents the interaction between macroblocksin terms of contacts established between elementary blocks, based on an accurate edge

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Neste artigo, apresenta-se uma breve descrição do papel da modelação física no apoio ao projeto de obras marítimas, seguida de um exemplo de ensaios realizados no âmbito da ampliação do porto de pesca de Rabo de Peixe, São Miguel

The Roman town of Ammaia (in Marvão Region) is considered one of the most important recent findings of the Roman presence in Portuguese territory. It was settled in Republican times and abandoned in the seventh century. In this research, 17 masonry mortars and renders from the West Tower (South Gate), the residential area near the West Tower, the macellum, the peristylium, the public bath building, the podium of the temple and the portico of the forum were analysed. The methodology of chemical, mineralogical and microstructural characterization has involved several complementary techniques, including stereomicroscopy, X-ray diffraction, thermal analysis and scanning electron microscopy coupled with energydispersive X-ray spectroscopy. The results indicate that the mortars from the beginning of the town’s edification were mainly composed of soil (clays). Later, during the main Roman building period, mortars were composed using a calcitic binder and the mortar composition varied according to their use and function. The samples from a period subsequent to the Roman occupation are based on a dolomitic binder. From the present study, relevant information has been acquired about the technological evolution of Roman construction in Ammaia, the historical context of the archaeological structures and guidelines for the conservation and restoration of mortars.

The control of water losses is a major concern in the sustainability of urban water utilities and inpromoting the efficient use of this natural resource. Recent advances in telemetry technology providehigh-resolution consumption data at the consumer level, allowing for a remarkable knowledgeimprovement on the different water balance components. However, few studies focus on systematicapproaches for improving system operation and maintenance by processing and analysing largeamounts of consumption data. This paper presents a new methodology to calculate real losses andapparent losses in distribution networks using data collected from telemetry systems. Themethodology proposes a set of algorithms that are simple to implement. These algorithms were testedon different district metered areas (DMA) to improve understanding about water loss components andhave already been included in commercial software. The results showed that these algorithms arerobust and allow for accurately estimating the background leakage level (and unreported leaks andbursts), detecting earlier the occurrence of bursts and providing important insights into the type ofillegal water uses. The use of these approaches reduced non-revenue water by more than 10% in themajority of the DMA tested. These findings are promising and demonstrate the strong potential oftelemetry systems to reduce water losses and to improve the understanding of water uses.

Em Portugal, e a nível mundial, existe um número significativo de estruturas de betão, que inclui pontes, viadutos, barragens, etc., onde se verifica a ocorrência de processos de deterioração com origem em reações expansivas internas do betão, mais especificamente reações álcalis-sílica (RAS) e reações sulfáticas internas (RSI). Face à importância social e económica daquelas estruturas e às consequências gravosas que podem advir deste tipo de reações, o LNEC tem desenvolvido uma intensa atividade de investigação e de realização de estudos e pareceres no domínio da prevenção da sua ocorrência em estruturas novas e do seu diagnóstico e prognóstico em estruturas já afetadas por estas anomalias. Na presente comunicação refere-se, de forma sucinta, a atividade que o LNEC tem vindo a realizar neste âmbito e as perspetivas futuras para a mitigação dos riscos associados ao desenvolvimento das reações expansivas internas no betão.

The increased demand for fuelwood may have the side-effect of unsustainable use of forest resource. The case of Kosovo fuelwood production is of a peculiar relevance to studying the drivers of the unsustainable patterns of forest biomass use in a post-war and poor economic context. The domestic market demand for fuelwood in Kosovo is estimated at more than 1.5 hm3, while the legal supply, including imports, is slightly higher than 0.3 hm3. Illegal logging for satisfying Kosovo population fuelwood needs is therefore widespread.The annual illegal fuelwood harvesting represents a market of up to 21.6 million euro and is done mostly by well organised groups of individuals, with market-oriented behaviour, acting rather in State than in private forests. After identifying the drivers of illegal logging for fuelwood, the paper provides an analysis of fuelwood extraction in relation with property rights distribution, structured along two lines: a) which was the evolution of the management and exclusion rights over the forest resource during the latest decades; b)which are the current enforcement mechanisms of the property rights and how are theyperforming. The paper describes a decades-long history of mismatching economic property rights arrangements. Thus, the dispute between the central agency and municipalities in performing exclusion rights on timber extraction definitely weakened the Kosovo system of law enforcement. Currently, the enforcement mechanism proved to be unhelpful incontrolling illegal logging. As result, most of the Kosovo fuelwood production is based onan de facto open-access regime.

The main goal of a wastewater treatment plant (WWTP) is to comply with the treated wastewater(TWW) quality requirements. However, the assessment of this compliance is a rather complex processfor WWTPs in the EU Member States, since it requires the integration of a large volume of data andseveral criteria according to EU Directives 91/271/EEC and 2000/60/EC. A tool for a comprehensiveassessment of TWW quality in this context is herein presented. The tool's novelty relies on an integratedanalysis of performance indicators (PIs) and new performance indices (PXs). PIs integrate the severalcompliance criteria into a single framework, supported by flowcharts for a straightforward assessment ofTWW compliance by practitioners. PXs are obtained by applying a performance function to the con-centration values analysed in the TWW for discharge or reuse. PXs are dimensionless and the scaleadopted (0e300) defines three performance levels: unsatisfactory, acceptable and good performance.The reference values proposed for these levels and for the PIs were based on the EU legislation. The PXscomplement the information provided by the PIs. While the latter assess the plant effectiveness in agiven year (i.e. the TWW compliance with the requirements), PXs tackle the plant reliability, i.e. theyallow to easily compare the performance of different parameters over the time and to identify when theperformance did satisfy or fail the pre-established objectives and the distance that remains to achievethese targets. The tool was tested in 17WWTPs and the most representative results are herein illustrated.