Artigos de Revista

This reflection explores the advantages of using visual methodologies to understand the urban cultural landscape, focusing on the use and appropriation of public space by immigrants. We based this discussion on an exploratory study developed for the Praça República in Ericeira, within the Metropolitan Area of Lisbon, that identified specific characteristics of the use and appropriation of urban public space by Brazilian immigrants. It identifies five advantages arising from the use of visual methodologies: (1) the process of collection and registration of information; (2) multiple possibilities of articulation between the visual techniques of observation and analysis and the interpretation techniques for other information collected; (3) enhancing inter/multidisciplinary potential through the working methodologies; (4) improving the capacity to respond to urban social diversity and complexity; (5) the potential for mapping the social practices of immigrants.

Princípios gerais da proposta para a revisão do RCCTE

A repetibilidade e a reprodutibilidade são duas caracteristicas metrológicas que, frequentemente, constituem relevantes contribuições para a incerteza de medição associada aos resultados de ensaios laboratoriais realizados em contexto industrial e técnico-cientifico. A sua quantificação permite uma análise diferenciada e combinada do efeito que os principais fatores intervenientes no processo de medição (designadamente, a instrumentação, o método e o operador) têm na qualidade dos resultados, promovendo a melhoria da qualidade dos processos laboratoriais e industriais e, por essa via, constituir uma ferramenta de apoio para a garantia da qualidade de produtos e serviços. Numa fase inicial, a presente comunicação pretende clarificar a definição destes dois conceitos [1] abordando-se, em seguida, o dimensionamento de ensaios laboratoriais de repetibilidade e reprodutibilidade, comparando a aplicação de métodos estatísticos clássicos (por exemplo, o método ANOVA) [2,3] com a exploração do método de simUlação numérica Bootstrap [4]. procurando avaliar a capacidade destes métodos para garantir resultados com elevado nível de confiança e para reduzir os custos económicos para os laboratórios decorrentes da necessidade de se promover este tipo de ensaios. A aplicação dos métodos acima mencionados é exemplificada em ensaios laboratoriais de medição dimensional sendo efetuada uma comparação de resultados experimentais, suportando a discussão da aplicação da abordagem alternativa constituída pela utilização de método de simulação numérica neste e noutros contextos onde a informação resulta essencialmente das amostras experimentais, como é o caso dos ensaios de comparação interlaboratorial.

The current study proposes prediction formulas both for random wave runup and mean overtopping discharge at seawalls constructed on land or in very shallow water. Although several existing formulas for runup and overtopping use the incident wave characteristics at the toes of seawalls, this study adopts the equivalent deepwater wave characteristics and an imaginary seawall slope for easy application of the formulas, especially in relation to seawalls constructed on land. The prediction formulas for overtopping use the predicted runup values. For the wave runup prediction formulas two sets of experimental data are used; i.e., a new set of data and the data obtained in a previous study. For the wave overtopping prediction formulas, the experimental data measured in a previous study are used. Comparisons with measurements show good performances of both new prediction methods.

Wave-current interactions play a major role in the dynamics of shallow tidal inlets. This study investigates these interactions at a natural inlet, with a strong focus on current-induced changes on wave propagation. The analysis of hydrodynamic data collected at the Albufeira lagoon, Portugal, revealed spatiotemporal variations of water levels and wave heights along the inlet, attributed to wave-current interaction processes. We compared the simulations of a coupled wave-circulation modeling system, computed with and without waves, and propagated with and without current feedback. The wave-induced setup inside the lagoon represented 7%–15% of the offshore significant wave height. The accuracy of the wave’s predictions improved when current feedback was included. During ebb, the currents increased the wave height at the mouth of the inlet (up to 20%) and decreased the wave height in the inlet (up to 40%), due to current-induced refraction, steepness dissipation, and partial blocking. During flood, the currents decreased the wave height in the inlet (up to 10%) and increased the wave height at the exterior parts of the ebb shoal (up to 10%), due to current-induced refraction. These effects significantly attenuate seaward sediment fluxes during ebb and contribute to the sediment accretion in the inlet.

A convenient approach to performing stability analysis of concrete gravity dams is the so-called twodimensional ‘‘gravity method.’’ However, concrete gravity dams located in valleys with sloped rock foundation abutments behave as three-dimensional (3D) structures and are often able to share compressive and shear loads between adjacent monoliths, especially when shear keys are present. A general 3D limit equilibrium method was developed in this study to compute global sliding safety factors (SSFg) by considering sequential load redistribution among adjacent monoliths when individual monoliths have mobilized their sliding strength. Two validation examples of the sliding safety assessment of existing dams are presented to illustrate the accuracy and efficiency of the proposed approach compared to that of the full 3D numerical analyses conducted using the distinct element method. It is shown that gravity dams may be formed by individual monoliths on sloped rock foundations that will slide if considered as isolated structures but will constitute a stable assembly when the load-sharing capabilities of monoliths are recognized in the analysis.

The main goal of this work is to establish a correlation between the oxidation induction time (OIT) and the oxidation induction temperature (OIT*), which are frequently used to assess the thermo-oxidative stability of polyolefins, either as raw-materials or as finished products. Several tests have been performed at different temperatures (200, 210 and 220 C) using a set of polyethylene (PE) samples from different sources. The correlations found - based on a quadratic regression – make it possible to estimate the OIT value based on experimental data of OIT* and vice-versa. This method can be quite useful in cases when the PE is highly stabilized so that the OIT test at 200 C is expected to last for hours. Additionally, an Arrhenius plot has been developed to obtain the activation energy (Ea) associated with the beginning of the thermo-oxidation for each PE, which also allows us to determine OIT from calculated Ea. All estimated values, obtained by the developed regression models, using unknown specimens, have been confirmed by experimental testing. The regression models have also been checked by a residual analysis as a way to evaluate their reliability. The contribution of the uncertainties of measurement and calculation has also been evaluated, leading to increased reliability of the findings.

N/A

Num agradável jogo urbano do pormenor é fundamental a participação, extremamente diversificada, das relações com a natureza e, especificamente, dos variadíssimos elementos de verde urbano. Realmente o verde urbano é fundamental e incontornável numa perspectiva de amenização do meio urbano, de melhoria das condições de conforto ambiental na cidade (temperatura, humidade) e é responsável por uma significativa parcela da fixação do CO2.

This study reports the development of a new spatial multi-criteria decision analysis (SMCDA) software tool for selecting suitable sites for Managed Aquifer Recharge (MAR) systems. The new SMCDA software tool functions based on the combination of existing multi-criteria evaluation methods with modern decision analysis techniques. More specifically, non-compensatory screening, criteria standardization and weighting, and Analytical Hierarchy Process (AHP) have been combined with Weighted Linear Combination (WLC) and Ordered Weighted Averaging (OWA). This SMCDA tool may be implemented with a wide range of decision maker’s preferences. The tool’s user-friendly interface helps guide the decision maker through the sequential steps for site selection, those steps namely being constraint mapping, criteria hierarchy, criteria standardization and weighting, and criteria overlay. The tool offers some predetermined default criteria and standard methods to increase the trade-off between ease-ofuse and efficiency. Integrated into ArcGIS, the tool has the advantage of using GIS tools for spatial analysis, and herein data may be processed and displayed. The tool is non-site specific, adaptive, and comprehensive, and may be applied to any type of site-selection problem. For demonstrating the robustness of the new tool, a case study was planned and executed at Algarve Region, Portugal. The efficiency of the SMCDA tool in the decision making process for selecting suitable sites for MAR was also demonstrated. Specific aspects of the tool such as built-in default criteria, explicit decision steps, and flexibility in choosing different options were key features, which benefited the study. The new SMCDA tool can be augmented by groundwater flow and transport modeling so as to achieve a more comprehensive approach to the selection process for the best locations of the MAR infiltration basins, as well as the locations of recovery wells and areas of groundwater protection. The new spatial multicriteria analysis tool has already been implemented within the GIS based Gabardine decision support system as an innovative MAR planning tool.