Artigos de Revista

The water availability estimation in large regions is a relevant procedure to define broad water resources management policies but may prove difficult due to the lack of data and uncertainty to related regional hydrological and hydrogeological characterization. BALSEQ, a daily sequential water budget model, was applied in a set of twenty-two watersheds in southern Portugal, aiming to understand the possible relations between the model parameters and watershed characteristics that may allow assembling calibration functions for non-monitored watersheds. A sensitivity analysis was conducted by comparing BALSEQ results with measured surface flow, focusing specifically on the fraction of the potential maximum retention (?) and the maximum amount of water available in the soil for evapotranspiration (AGUT) parameters and the underlying hydrogeological conceptual model that ultimately controls the surface-groundwater interactions. The overall results did not allow to identify clear relations that permit extrapolation to other regions without data as the sensitivity analysis procedures returned similar results for wide intervals of parameters for the majority of watersheds. The results confirmed that the groundwater discharge is an important component for the total measured surface flow and that the ? parameter should not be overlooked when calculating direct runoff. Poor adjustments between the model results and measured flow were observed in watersheds with a low Surface flow – Rainfall ratio.

Neste quarto artigo (de oito) da série editorial intitulada “Desenvolver a qualidade arquitectónica e a satisfação residencial na nova habitação de interesse social portuguesa”, faz-se uma síntese, essencialmente qualitativa, do que se julga ter sido o processo de apoio à promoção de Habitação a Custos Controlados (HCC), indiretamente pelo INH/IHRU e diretamente por municípios, cooperativas e empresas. Em primeiro lugar desenvolve-se um reenquadramento sistemático e justificativo dos diversos artigos desta série editorial. Depois e sequencialmente: (i) apontam-se algumas das problemáticas/questões globais levantadas pela promoção de HCC; (ii) apresentam-se as principais características da HCC e suas principais tendências, primeiro numa perspectiva dos diversos níveis físicos residenciais e, depois, no âmbito dos três tipos de promoção de HCC – cooperativa, municipal e privada; e (iii) finalmente apontam-se as facetas mais significativas do desenvolvimento dos conjuntos residenciais de HCC, desde a fase de obtenção do terreno à ocupação das habitações.

Stability analyses of geotechnical structures in rock are traditionally performed using deterministic methods. In Europe, Eurocode7, introduced in the beginning of the 21st century, adopts limit state design and semi-probabilistic methods, using partial factors for the design of geotechnical structures. Meanwhile, reliability-based design, using probabilistic methods, is becoming more common in practical cases. The paper considers an intentionally simple case study?the analysis of a slope in a rock mass with one discontinuity, considered in a discrete way, forming a rock block to be stabilised by anchors?to compare the results obtained with the different methods. The objective is to calculate the force applied by the anchors so that the ultimate limit states of sliding of the rock block is verified. Deterministic-based design optimization considering both the traditional global safety factor approach and the partial factor approach following the Eurocode 7 are first applied. A reliability-based design optimization procedure?which takes geometrical and mechanical properties of the discontinuities as random variables?is then used, and the results are compared to the former ones. A discussion is presented concerning the consistency of the obtained results.

TiO2-containing photocatalysts, which combine TiO2 with carbon-based materials, are promising materials for wastewater treatment due to synergistic photodegradation and adsorption phenomena. In this work, TiO2/AC composites were produced by the in situ immobilization of TiO2 nanoparticles over activated carbon (AC) derived from spent coffee grains, using different TiO2/AC proportions. The TiO2/AC composites were tested as adsorbents (dark) and as photocatalysts in a combined adsorption+photocatalytic process (solar irradiation) for methylene blue (MB) removal from ultrapure water, and from a secondary effluent (SecEf) of an urban wastewater treatment plant. All the materials were characterized by XRD (X-ray powder diffraction), N2 adsorption–desorption isotherms at ?196 °C, SEM (scanning electron microscopy), UV-Vis diffuse reflectance, FTIR (Fourier-transform infrared spectroscopy), TPD (temperature programmed desorption), XPS (X-ray photoelectron spectroscopy) and TGA (thermogravimetric analysis). The TiAC60 (60% C) composite presented the lowest band gap (1.84 eV), while, for TiAC29 (29% C), the value was close to that of bare TiO2 (3.18 vs. 3.17 eV). Regardless of the material, the solar irradiation improved the percentage of MB discolouration when compared to adsorption in dark conditions. In the case of simultaneous adsorption+photocatalytic assays performed in ultrapure water, TiAC29 presented the fastest MB removal. Nevertheless, both TiAC29 and TiAC60 led to excellent MB removal percentages (96.1–98.1%). UV-induced photoregeneration was a promising strategy to recover the adsorption capacity of the materials, especially for TiAC60 and AC (>95%). When the assays were performed in SecEf, all the materials promoted discolouration percentages close to those obtained in ultrapure water. The bulk water parameters revealed that TiAC60 allowed the removal of a higher amount of MB, associated with the overall improvement of the SecEf quality.

The subgrade of old railway tracks often exhibits poor geotechnical behaviour, particularly regarding the soils on which the ballast layer rests. Such poor behaviour implies significant maintenance costs and possession times. The reinforcement of subgrade soils by injection of binders may mitigate these malfunctions, but previous applications showed some limitations, and the quality of the results depends on many factors. Herein, the authors present some studies on the development of a subgrade reinforcement method, which minimises the impact on train operation, by using short soil–binder columns, formed with grouts injected into the subgrade by drilling through the ballast layer. Laboratory studies were performed to determine the strength and deformability of the mixtures of a clay soil with lime or cement. To assess the improvement of the geotechnical characteristics of that soil and to determine the permanent deformation of the track structure under cyclic loading, tests were performed on full-scale physical models. A reduction of about 60–80% was observed in settlement amplitudes of the reinforced physical models under cyclic loading. Lastly, the reinforcement method was employed on a track in operation that exhibited a poor behaviour, the subsequent geotechnical improvements were assessed and the dynamic responses of the track before and after grouting were compared. After the treatment, a general reduction of about 15–20% was observed in peak vertical accelerations measured on the sleepers. The results suggest that, from both the technical and the economic viewpoints, the proposed reinforcement method is a valid alternative for rehabilitating railway platforms, notably in old single-track lines.

Sensor networks used in environmental monitoring applications are subject to harsh environmental conditions and hence are prone to experience failures in its measurements. Comparing to the common task of outlier detection in sensor data, we review herein the complex problem of detecting systematic failures such as drifts and offsets. Performing this detection in environmental monitoring networks becomes a stringent task especially when we need to distinguish data errors from real data deviations due to natural phenomenon. In this paper, we detail the scope of events and failures in sensor networks and, considering those differences, we introduce a new instantiation of a proven methodology for dependable runtime detection of outliers in environmental monitoring systems to address drifts and offsets. Lastly, we discuss the use of machine learning techniques to estimate the network sensors measurements based on the knowledge of processed past measurements alongside with the current neighbor sensors observations.

The introduction of new species in forest management must be undertaken with a degree of care, to help prevent the spread of invasive species. However, new species with higher profitability are needed to increase forest products value and the resilience of rural populations. Paulownia tomentosa has an extremely fast growth. The objective and novelty of this work was to study the potential use of young Paulownia trees grown in Portugal by using heat treatment to improve its properties, thereby allowing higher value applications of the wood. The average chemical composition of untreated and heat-treated wood was determined. The extractive content was determined by successive Soxhlet extraction with dichloromethane (DCM), ethanol and water as solvents. The composition of lipophilic extracts was performed by injection in GC-MS with mass detection. Insoluble and soluble lignin, holocellulose and ?-cellulose were also determined. Physical (density and water absorption and dimensional stability) and mechanical properties (bending strength and bending stiffness) and termite resistance was also determined. Results showed that extractive content increased in all solvents, lignin and ?-cellulose also increased and hemicelluloses decreased. Compounds derived from the thermal degradation of lignin were found in heat-treated wood extractions. Dimensional stability improved but there was a decrease in mechanical properties. Resistance against termites was better for untreated wood than for heat-treated wood, possibly due to the thermal degradation of some toxic extractives.

Although the chronology of the tiling of Bacalhôa with majolica azulejos was always known to be around 1565, given the date inscribed in the panel representing the biblical episode of Susanna and the Elders, their provenance as well as the authorship of the figurative panels, remained clouded and open to personal opinion. A previous analytical study of the main panels and linings with patterned tiles of Bacalhôa concluded that some of them could not be ascribed to the workshops of Lisbon at that chronology, differing in terms of glaze and biscuit compositions and micro-morphology, suggesting that they may have been imported. The present paper presents a detailed study of those presumably imported panels and patterned tiles, firstly setting a reference based on the micro-morphological and analytical characteristics of the two panels depicting coats of arms, and then comparing the remaining items with them to verify whether they may be clustered together. Finally, we discuss their possible provenance.

This essay provides an overview of the architecture of the Bacalhôa palace and estate, and of some of its ceramic panels and linings. The estate comprises a varied range of tiles but the research project encompassing the present study focuses exclusively on the 16th century majolica type. Consequently, this article will make only sporadic or indirect references to Hispano-Moresque tiles. The project also included iconographic interpretations of certain significant azulejo panels and patterned tiles but these will be included in future papers specifically dedicated to those particular parts of the majolica tile linings, rather than as an integral aspect of the present study. Accordingly, this essay only includes iconographic details of groups of tiles that will not be examined in subsequent articles. This applies to the tiles of the Lake Wall and in the Vineyard Chapels.

This paper reviews the state-of-the-art in storm surge forecasting and its particular application in the northern Adriatic Sea. The city of Venice relies crucially on a good flood forecasting system in order to protect the extensive cultural heritage, their population, and their economic activities. Storm surge forecasting systems are in place to warn the population of imminent flood threats. In the future, it will be of paramount importance to increase the reliability of these forecasting systems, especially with the new MOSE mobile barriers that will be completed by 2021, and will depend on accurate storm 35 surge forecasting to control their operation. In this paper, the physics behind the flooding of Venice is discussed, and the state of the art of European storm surge forecasting is reviewed. The challenges that lie ahead for Venice and its forecasting systems are analyzed, especially in view of uncertainty. Some extreme events that happened in the past and were particularly difficult to forecast are also described