Artigos de Revista

The present project addresses a problem related to the erosion effects on a breakwater barrier due to waves which leads to its degradation and that may eventually lead to lack of functionality of the structure. In the present case, the breakwater acts as a physical barrier between the Atlantic Ocean and the cargo Harbour of Leixões, in Matosinhos, Portugal, justifying the needs of health monitoring of the barrier.To monitor this structure, with a length of roughly 700 m, the need of a fast data acquisition system led to the choice of imaging techniques which allow for a fast acquisition of a diversified data set. The images were acquired using a high-resolution camera attached to an unmanned aerial vehicle (UAV), enabling a faster and more automated procedure that leads to the systematization of the process, while being compatible with the difficult accessibility of the structure, which is surrounded by sea waves. Point clouds corresponding to the breakwater

Storms impacting sandy coastal areas produce hazard such as erosion as overwash, in turn, promote risk to life and property damage in occupied areas.

A tunnel fire is a dangerous accident, which may lead to serious injuries and deaths. This work studies the flow of combustion products during naturally ventilated tunnel fires, i.e., without a mechanical ventilation system. In such an event, two stratified layers with opposing velocity directions are formed. The safety of tunnel users is compromised if the smoke, initially flowing in the upper layer, contaminates the lower one, which has been found to happen abruptly at a distance xc from the fire. This is caused by the cooling of the jet leading to a large enough decrease in momentum for the smoke to be entrained by the lower layer. Natural ventilation may be an effective and inexpensive smoke control strategy if the fire-to-portal distance is shorter than xc. However, there is a lack of research to predict under which conditions this occurs and how xc is influenced by factors such as natural wind. An open-source Computational Fluid Dynamics (CFD) code, fireFoam, was used to conduct Large Eddy Simulations (LES) of naturally ventilated tunnel fires. The numerical model was validated by performing a simulation of a large-scale tunnel fire test. Additionally, 7 fire scenarios with varying wind velocities were simulated. The contamination distance xc was found to decrease for higher wind velocities. Furthermore, a simple semi-analytical model was employed to obtain quick estimates of xc, by calculating ceiling jet properties using balance equations and empirical correlations. Model coefficients were calculated using the CFD results.

Performance assessment is essential for effectively managing drinking water systems. It allows to understand the system's behaviour, identify critical components and subsystems, and help with the decision analysis of measures to improve economic, infrastructural and water and energy resources. The current paper proposes an updated methodology for diagnosing drinking water networks, considering different perspectives: water and energy efficiency, infrastructural sustainability, and the quality of service provided, including resilience and redundancy concepts. Several performance indicators and indexes, including Resilience index and Entropy, are recommended to describe each perspective. The methodology is applied to a real-life network, and the attained results are discussed. The status quo situation for the network area is assessed, and the main problems are identified (i.e., high friction losses, inefficient pump operation, old pump equipment). Different improvement solutions are considered (e.g., pipe replacement with higher diameter, pump operation improvement, pump replacement). These interventions are considered individually or combined. Using the resilience-based perspective with other performance assessment criteria has provided a broader assessment. The resilience index has proven sensitive to the different alternatives, endorsing the system's efficiency. Smaller values of the resilience index indicate that a small amount of energy in excess is available as surplus energy in the consumption nodes, being dissipated, either as pumping inefficiencies, water losses, or friction and singular head losses. The Entropy metric is sensitive to the network layout and is helpful in alternatives that consider flow path alterations to prevent the impact of pipe failure. The best improvement alternative achieves a considerable enhancement in energy efficiency, maintains a good quality of service, improves the system's infrastructural sustainability, and corresponds to the highest resilience index value.

Among thermal insulation solutions for historic walls, thermal renders and plasters appear to be a very feasible option. Thus, this work analyses commercially available thermal mortars suitable for the scope.An extensive experimental campaign showed that testing single materials only, which is the standard requirement for thermal mortar-based systems, is in fact not sufficient for understanding the potential impact of the intervention on walls: whole-systems should also be examined. This study provides a detailed characterization of materials and systems, useful as a database for forthcoming investigations on compatibility and efficacy for application on historic walls, via numerical hygrothermal simulations.

A complexidade do sistema via-férrea, em termos da variabilidade do comportamento estrutural e material ao longo de seu ciclo de vida, tem-se constituído um obstáculo para o estabelecimento de métodos robustos de previsão do seu comportamento de longo-prazo. Neste trabalho apresenta-se uma implementação computacional que incorpora algumas funcionalidades para uma reprodução mais realista desse comportamento, face a outras existentes. Para demonstrar as potencialidades desta ferramenta, são analisados cenários de plena via, tendo-se introduzido, em alguns deles, uma travessa sem apoio na camada de balastro (

Twenty-four pharmaceutical active compounds (PhACs) were evaluated in the soft tissues of clams Ruditappesdecussatus exposed along a 1.5-km dispersal gradient of the treated effluent from an urban wastewater treatment plant discharging in Ria Formosa, and compared with those in the marine waters and discharged effluents.

Methodologies to be used in numerical models based on Reynolds-averaged Navier

Na primeira parte do artigo e no que se refere ao quadro físico de um habitar que se deseja adequado e estimulante de um convívio natural, apontam-se aspetos ligados a uma agradável opção entre privacidade/solidão e convívio iniciada no espaço público envolvente, passa-se, em seguida, para o favorecimento de condições naturais de convívio residencial, aborda-se o privilegiar de espaços e ambientes residenciais que favoreçam o convívio espontâneo e, finalmente, comenta-se o que se deseja que seja uma agradável opção entre privacidade e convívio doméstico.Na segunda parte do artigo e no que se refere à diferenciação entre uma solidão imposta e uma seclusão opcional e acompanhada por um convívio natural, aborda-se, em primeiro lugar, o que se julga ser uma situação atual muito marcada por uma solidão imposta (não desejada), avança-se, em seguida, para uma comparação entre o prazer de viver só e o convívio desejado e aponta-se, finalmente, o que se deseja possa ser a construção de um quadro social e físico « de companhia » (que favoreça um sentimento de « companhia » natural).Na terceira parte do artigo e ainda na matéria da diferenciação entre uma solidão imposta e uma seclusão opcional e acompanhada por um convívio natural, mas agora numa perspetiva mais física e ligada a soluções de habitar tratam-se, sequencialmente as seguinte subtemáticas: poder estar sozinho, mas sempre estrategicamente, acompanhado; a importância de um espaço habitacional adaptado às necessidades dos mais frágeis e consequentemente promotor do seu bem-estar e da sua saúde ; a importância dos espaços exteriores residenciais como promotores do bem-estar e da saúde dos mais frágeis ; e os aspetos associados ao viver juntos em edifícios funcionalmente mistos e estimulantes.O artigo integra, ainda, uma quarta parte com uma abordagem sintética dos problemas conjugados associados à solidão e à prestação de cuidados pessoais.