Artigos de Revista

Descrevem-se os procedimentos para a avaliação da distribuição dos movimentos verticais de um navio em manobranuma bacia portuária e que incluem a definição da função resposta do navio a ondas monocromáticas nele incidentes,bem como a determinação das características da agitação marítima ao longo do trajeto do navio. Ilustra-se a influênciada velocidade de avanço do navio naquela distribuição avaliando-se a probabilidade de ocorrência de movimentosverticais superiores a um limiar pré-definido na manobra de um navio no porto da Praia da Vitória, Açores.

Numerical modeling of the interaction between waves and coastal structures is a challenge due to the many nonlinearphenomena involved, such as wave propagation, wave transformation with water depth, interaction between incident andreflected waves, runup/rundown and wave overtopping. For simulating such complex free-surface flows, numerical modelsbased on Lagrangian formulation, such as Smoothed Particle Hydrodynamics (SPH), are on option. Even though validationof these numerical models is essential, comparing numerical results with experimental data is not an easy task. In thepresent paper, an SPH numerical model is validated comparing numerical results of waves interacting with a compositebreakwater with data obtained from physical model tests carried out in one of the LNEC

Groins are cross shore structures built to promote shoreline stabilization. However, the specific impact of these structures on the wave conditions and velocity field nearshore (and hence, on sediment transport) is still poorly understood. Therefore, this study wishes to extend this knowledge using a numerical model, COULWAVE, previously validated with field data. For that, a typical bar-trough profile is considered and different groin lengths and orientations are tested, under the influence of different significant incident-wave heights and sea-surface levels.The hydrodynamics factors are found to have a greater impact on the nearshore wave conditions than the groin geometry. The variation of significant incident-wave height imparts the greater changes in wave height nearshore, where the groin would be located. The typical tidal range is also important, since a 2 m change in sea surface level can cause great depth changes over bathymetric features and thus influence wave propagation. Although less important, the geometry of the groin should also be considered. The greater the length, the greater the sheltering effect expected, extending further to the lee-side of the groin. The impact will also reach a broader region. With a smaller impact verified, the best orientation of the groin is hard to unravel.

The Aveiro coastal area is highly vulnerable to erosion, becauseit is constituted primarily by low-lying lands of sandy sedimentsthat are frequently subjected to severe wave conditions and largetidal amplitudes (Coelho et al., 2011), as well as due to the closeproximity to the Aveiro lagoon and several urban waterfronts. Inthis region the problems associated with coastal erosion are oftenreported and discussed (Coelho, 2005; EUrosion, 2006;Pais-Barbosa et al., 2006; Coelho et al., 2007), constituting aconcern for the local populations and stakeholders. Furthermore,the retreat of the shoreline may imply the breaching of a newentrance to the Aveiro lagoon, which would cause major social,economic and environmental impacts. This breaching has onlybeen avoided by emergency works which have been carried outfrequently over the past few years. Increased vulnerability ismainly related to the sedimentary deficit registered in thePortuguese coast, due to the decrease of incoming sediments fromriver sources (Mota-Oliveira, 1997).Over the years the Esmoriz-Furadouro and Vagueira-Mirastretches have been affected by flood and erosion processes due tocoastal vulnerability to sea wave

The study of ways of converting ocean wave energy into a useful one and the improvement of theexisting equipment are complex engineering problems and very important issues in today

A reciprocidade e aceitação mútua entre grupos sociais em copresença são indispensáveis à integração social e à coesão social mais alargada. A identidade social (Tafjel, 1972) constitui um conceito incontornável no entendimento das relações intergrupais, dado que reflecte trajectórias individuais e sociais e fornece sinais sobre situações de (des)ajustamento social. Através de uma entrevista estruturada, o presente estudo procura compreender os processos identitários de imigrantes africanos e de ciganos e discute o papel destes processos na promoção da integração social. A partir da identificação de valorização de aspectos do grupo étnico/etno-nacional e do grupo maioritário em vários domínios construiu-se uma tipologia de identidade étnica (Hutnik, 1991). Os principais resultados indicam a existência de uma dicotomia entre aculturação (adesão simultânea a valores, normas e regras de ambos os grupos) e dissociação (expressão de forte identificação em relação ao próprio grupo e afastamento relativamente ao grupo maioritário). A baixa prevalência de indivíduos em processos de marginalização, ou seja, que veiculam representações negativas sobre ambos os grupos, é um bom indício de integração destas populações. No entanto, o peso razoável de pessoas em dissociação representa um risco social marcante dado que traduz um fechamento no próprio grupo e um afastamento da sociedade de acolhimento. Estes resultados salientam a promoção da proximidade social entre maioria-minoria, o que ajudaria os grupos a encararem a sua cultura de uma forma mais flexível, mais negociada e, sobretudo, mais ajustada aos valores actuais, reduzindo, desta forma, conflitos e tensões entre grupos étnicos e etno-nacionais e com a maioria.

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Road restraint systems are roadside structures that include safety barriers, crash cushions, terminal of barriers, the transitions among different road restraint systems, motorcyclist protection devices, etc. These systems are used to protect vehicle occupants from dangerous roadside elements and are a key issue in roadside safety.In Europe, safety barriers are currently designed for different performance levels using three main criteria: containment, impact severity and deformation of the barrier.The impact severity level is exclusively associated with injury risk to vehicle occupants and assumes that different severity levels correspond to different levels of injuries.From these observations, three questions emerge: what consequences can be expected for the passengers of an errant vehicle when it is contained by a safety barrier? Systems with different impact severity levels lead to diverse severity consequences? What are the benefits of using barriers with lower impact severity levels?To answer these questions this paper examines how the number of run-off-the-road crashes and victims

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