Artigos de Revista

Estuaries are coastal systems particularly vulnerableto climate change. Within these systems, agricultureis one of the most potentially affected sectors. This paperproposes a risk assessment approach for helping thedecision-making process at a local level, addressing two risksthat affect agricultural areas located in estuarine margins:the unavailability of freshwater for irrigation resulting fromthe upstream propagation of estuarine brackish water duringdroughts and land inundation by high water levels associatedwith high tides and storm surges. For each risk,quantitative consequence descriptors are proposed to supportrisk level determination and evaluation through a continuousconsequence

Abstract: Vertical air curtains are often used to separate two different zones to reduce contaminant transfer or even to provide aerodynamic sealing from one zone to the other. In this isothermal full-size experimental research work, the contaminant transfer between zones is reduced using an air extraction from the “contaminated” compartment and an air curtain. This work correlates the minimum exhaust air flow rate required to reach the aerodynamic sealing at the opening connecting two different zones with the jet nozzle velocity for small nozzle thicknesses (5 mm, 10 mm and 16 mm), particularly for Reynolds numbers below 3800. Following the experimental study, a general physical law that relates the jet parameters (angle, nozzle thickness and jet velocity at the nozzle) with the average velocity through the opening (for the condition of acceptable contaminant tightness) was obtained. The results showed that the average velocity of the flow across a door protected by an air curtain required to keep the aerodynamic sealing varies linearly with Re. The slope, however, is different below and above Re = 3820.

The geomechanical behaviour of railway ballast is a key aspect in the performance of ballasted tracks, mainly under increased axle loads and/or train speeds. Recently, and driven by the circular economy paradigm, some researchers have evaluated the use of alternative ballast materials as replacement for traditional natural crushed rocks. This work presents a comparison between the geomechanical behaviour of a granite aggregate and the one of an electrical arc furnace steel slag aggregate, with the trade designation of

A prestação dos serviços de água e esgotamento sanitário depende de infraestruturas constituídas por ativosde longa duração, com elevados custos de investimento, de construção e de reabilitação. Por essa razão, agestão de ativos, ou seja, a gestão estratégica e racional de infraestruturas, é atualmente reconhecida comoindispensável para a eficiência, a eficácia e a sustentabilidade dos serviços. Porém, essa prática ainda não estágeneralizada, havendo um longo caminho a percorrer. Os reguladores do setor têm uma especial responsabilidadepara alterarem a situação, sensibilizando a sociedade e os decisores políticos, contribuindo para umacultura de gestão que inclua o longo prazo, criando medidas promotoras de gestão de ativos. Este artigocontextualiza o tema e sistematiza medidas de regulação promotoras de uma melhor gestão de ativos.

Rehabilitation of facades may be carried out with the application of External Thermal Insulation Systems (ETICS). Their main contribution is the increase of the energy efficiency of buildings. In the literature, hygrothermal, impact and fire performance studies have been carried out on several systems with different insulation materials, such as expanded polystyrene, mineral wool and extruded polystyrene foam insulation. Due to the growing concern with the environment, systems are being developed with more sustainable and ecological materials, such as ICB (expanded cork). These type of boards are responsible for a negative impact in global warming potential, significantly improving the environmental benefits of their use. As these systems were recently introduced to the market, applications on site are very recent and their behaviour over time still unknown. In this research, the durability and global performance of more sustainable systems (with ICB) were analysed through an experimental campaign and compared with EPS (expanded polystyrene) systems. The results show that the systems with ICB obtained satisfactory global behaviour comparable with the EPS systems. The ICB sustainable systems analysed stood out in acoustic performance. ...

For 12 years, in Portugal, a waste deposit was in contact with the underlying ground. The waste, fly ash, wasproduced by electric arc furnaces of the Portuguese Iron and Steel Company. The subsoil consisted of waste rock spoils from an old coal mine site. The waste was transported to the site as part of a recovery operation. At the time of the operation, the waste was classified as

Two pilot trials of powdered activated carbon (PAC)/(coagulation)/ceramic microfiltration were conducted to compare continuous 10

The Paraíba and Pernambuco basins are part of the Northeast Brazilian rift system, which contains a series ofCretaceous terrestrial to marine sediments covered by Neogene-Quaternary deposits. Their main aquifers (i.e.Barreiras, Beberibe, Cabo, Quaternary and, Fractured) constitute multi-layered aquifer systems and are the mainstrategical source of drinking water for the Recife Metropolitan Region. In this research, 323 physical-chemicalsamples along with 25 isotopic groundwater analyses were used to characterize the main hydrochemical processescontrolling groundwater

Keeping an effective disinfectant residual concentration in reclaimed water is still a challenge, due to its high levels of ammonia and organic matter when compared with those in drinking water. This research proposes the integration of the reaction schemes of monochloramine autodecomposition with an empirical kinetic mechanism accounting for reactive chlorine species decay in the presence of organic matter, for which three mechanisms were hypothesized and tested. A parallel second order mechanism, where monochloramine reacts both with fast and slow organic matter reactive fractions, was identified as the most suitable. The model, comprising two rate constants and two fictive concentrations of organic matter as parameters, was further successfully calibrated with real reclaimed waters with two initial free chlorine doses of 8.01 x 10-5 M (