Papers

In this contribution we summarize the current status of the known termites of the Azores(North Atlantic; 37-40° N, 25-31° W). Since 2000, four species of termites have been identified in the Azorean archipelago. These are spreading throughout the islands and becoming common structural and agricultural pests. Two termites of the Kalotermitidae family, Cryptotermesbrevis (Walker) and Kalotermes flavicollis (Fabricius) are found on six and threeof the islands, respectively. The other two species, the subterranean termites Reticulitermes grassei Clemént and R. flavipes (Kollar) of the Rhinotermitidae family are found only in confined areas of the cities of Horta (Faial) and Praia da Vitória (Terceira) respectively.Due to its location and weather conditions the Azorean archipelago is vulnerable to colonization by invasive species. The fact that there are four different species of termites in the Azores, all of them considered pests, is a matter of concern. Here we present a comparativedescription of these species, their known distribution in the archipelago, which control measures are being used against them, and what can be done in the future to eradicate and control these pests in the Azores.

The economic appraisal of the external effects of transport options can provide important data for policy making. On the other hand, impacts of non-motorized modes have often been undervalued in comparison to other transport modes. To this end, assessing the potential health benefits of walking and cycling is being increasingly recognized as an important step to promote sustainable mobility policies.This paper is built upon the contracted study for the World Health Organization (WHO) on the economic appraisal of health benefits of walking and cycling investments for the City of Viana do Castelo. This Portuguese city which integrates the WHO European Healthy Cities Network provided a suitable policy context for the former application in Portugal of the WHO Health Economic Assessment Model (HEAT) for appraising the health benefits of non-motorized transport. The study comprised the evaluation of the following investment actions: a) Improvements of the urban public space for pedestrians; b) Planning future cycling infrastructures. This paper provides a discussion of the methodological challenges and key findings that have arisen from the WHO HEAT application study, when trying to answer the following questions:- If x people cycle (or walk) a distance of y kilometers on most days, what is the economic value of the correspondent health benefits? - What levels of uptake of cycling in the future are required for the cycling plan to be economic viable? - What health benefits are associated to a projected increase in the traffic levels of pedestrians (% increase from the reference level)? - Do health benefits of cycling (and walking) investments outweigh their costs?Results from this study make it able to add novel evidence for the Portuguese urban context on the potential health benefits of walking and cycling (maximum and mean annual health benefits), including the cost-benefit ratio indicators. These indicators are expected to be useful for policy makers and city officers involved in the promotion of sustainable mobility.

This paper summarizes the result of a study regarding the creation of tools that can be used in intervention methods in the planning and management of urban road networks in Portugal. The first tool relates the creation of a geocoded database of road accidents occurred in Lisbon between 2004 and 2007, which allowed the definition of digital maps, with the possibility of a wide range of consultations and crossing of information.The second tool concerns the development of models to estimate the frequency of accidents on urban networks, according to different desegregations: road element (intersections and segments); type of accident (accidents with and without pedestrians); and inclusion of explanatory variables related to the road environment. Several methods were used to assess the goodness of fit of the developed models, allowing more robust conclusions.This work aims to contribute to the scientific knowledge of accidents phenomenon in Portugal, with detailed and accurate information on the factors affecting its occurrence. This allows to explicitly include safety aspects in planning and road management tasks.

Ventilation systems play an important role in the energy consumption of heating and cooling, defining hygrothermal conditions and air quality of dwellings. Among other functions, they are absolutely necessary to ensure oxygen levels needed for household combustion appliances. In Portugal in multifamily housing and with natural ventilation systems, installing a mechanical exhaust fan in every kitchen (decentralized ventilation) is common. In this paper, the impact of such a device is evaluated regarding the performance of a water heating appliance for heating the indoor environment or for domestic hot water (B-type gas appliance usually installed in the kitchen). The combination of natural or mechanical ventilation in the kitchen with the natural exhaust of the gas appliance’s combustion products were tested as well as the evaluation of critical conditions that lead to stopping the gas appliance safely or to reversing the combustion products in the respective exhaust duct. One of the main conclusions to be drawn is that in the case of mechanical exhaust in the kitchen simultaneously with the natural exhaust of the gas appliance’s combustion products, the kitchen’s exterior air inlet is a key device for ensuring proper exhaust of combustion products. In extreme situations, reduced air intake by other means or high extraction flows, they can prevent safely stopping the appliance or even reversing the flow of the combustion products. For this purpose, the maximum flow of mechanical exhaust should also be limited.

The purpose of this research work is to identify the effect of the daily variation of the air temperature on the structural response of a concrete dam. It is intended to obtain a better knowledge about structuralbehaviour of concrete dams. In current day to day activities, quantitative interpretation models are used for the assessment of structural dam behaviour of concrete dams. Most models ignore the temperature effect of a wave with a daily variation. However, in dams with automated data acquisition systems this daily effect can be used to anticipate the detection of abnormal behaviour.In this paper, the Short Time Fourier Transform analysis of the residuals is used, obtained by the quantitative interpretation models and measurement data, to identify the signature that the daily variation of the air temperature has on the structural behaviour of a concrete dam. A case study is presented based on the analysis of a horizontal displacement measured on a pendulum, in the Alto Lindoso concrete dam. As a result, the relation between magnitudes of daily variations of the horizontal displacement analysed and the air temperature was defined. The relation obtained can be used to assess if there is alterations or not in the dam response to short period loads corresponding to the daily variations analysed.

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The reported experimental study assesses the effects of flow non-uniformity on the momentum flux in straight compound channels. Two flumes wereused, featuring vertical and sloping banks. Starting with uniform flow condition, various imbalances in the upstream discharge distribution wereintroduced. This resulted in a time-averaged lateral flow and advective transport of momentum, which interacted with the shear-layer turbulencegenerated by the compound geometry. To investigate this interaction, the three contributions to transverse momentum flux (depth-averaged flow,shear-layer turbulence and dispersive term of spanwise velocity) are assessed. The first two contributions were strengthened by the sloping banks,while the third becomes important for the case of the vertical bank. With a lateral flow towards the main channel, the first contribution rises at theexpense of the second. With a lateral flow towards the floodplain, the first two contributions have the same order of magnitude, and the Boussinesqapproach is invalidated.

Modelos detalhados de partículas têm sido adotados na modelação da fratura em materiais quase-frágeis. Neste artigo é adotado um modelo de partículas 2D que tem sido desenvolvido tendo em vista o estudo da fratura em rocha. Os sistemas de partículas são gerados com base num algoritmo de geração de partículas poligonais baseado nos Voronois de Laguerre da triangulação de Delaunay dos centros de gravidade das partículas circulares. O modelo de partículas poligonais, aproximado através de partículas circulares que interagem entre si através de um esquema de contacto múltiplo, é validado em ensaios biaxiais, e em ensaios do tipo Brasileiro, em rocha. São apresentados vários estudos paramétricos que permitem identificar a influência dos parâmetros micromecânicos nas propriedades macroscópicas, elásticas e resistentes. É por fim analisada a relevância de um modelo de contacto com leis de enfraquecimento bilinear em tração e corte de modo a obter valores coerentes de tração última nos ensaios diretos e nos ensaios Brasileiros.

This study is focused on the electrochemical behavior and surface analysis of an eco-friendly organic–inorganic hybrid (OIH) coating for hot dip galvanized steel (HDGS) in contact with cementitious media. This treatment is a proposed alternative to replace toxic Cr(VI)-based pre-treatments used to control reactions between the zinc and wet concrete. HDGS samples were coated with two different sets of OIH gels obtained by a sol-gel process using a dip-coating method. Five distinct OIH matrices were obtained by reaction of functionalized metal-alkoxide (3-isocyanatopropyltriethoxysilane) with five different molecular weight diamine-alkylethers. One set of HDGS samples was coated with each of the five pure OIH matrices and another was coated with similar matrices doped with Cr(III). The morphology of OIH coatings over HDGS surface was characterized by SEM/EDS. Similar films were prepared separately and the respective resistivity was measured by electrochemical impedance spectroscopy. Polarization resistance and macrocell current density were used to evaluate the corrosion protection properties of the HDGS coated samples in contact with cementitious media for a period of 74 days. Results showed that the produced coatings provide barrier properties that withstand the high pH of the electrolyte, protecting the HDGS when it first contacts cementitious media.

This work uses a simple method based on the defect law that is able to reproduce the horizontal velocities within the wave bottom boundary layer, using a limited number of parameters. The theory is checked against the measured velocity profiles gathered with a high resolution Acoustic Doppler Velocity Profiler. The velocities were collected during an experimental project performed at the Large Oscillating Water Tunnel of Deltares under flat-bed/sheet flow conditions, allowing the analysis of the effects of wave nonlinearities and of a net current on the sediment transport processes. The velocity estimates are used to infer the time-varying bed shear stress, using the momentum-integral method. Secondly, the bed shear stresses are incorporated in a quasi-steady bed load formulation and the transport rate predictions are compared with the net transport rate measurements obtained in the same facility. The results show that the methodology presented in this work provides a suitable estimation of the horizontal near-bed sediment transport rates under non-linear oscillatory flows.