Browsing by Issue Date, starting with "2009"
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- An integrated investigation of the Rio tailings, Panasqueira mine, Centre PortugalPublication . Grangeia, Carlos; Ávila, Paula Freire; Matias, Manuel; Silva, E. Ferreira daThe risks associated with mine tailings have different nature and, thus, only a multiple approach can investigate and monitor comprehensively the characteristics and evolution of mine tailings impacts on the environment. Deposition at the Rio tailings (Panasqueira Mine) lasted about ninety years. Over one million cubic metres, of complex very fine to fine material, are deposited on a mountain side overlaying the Zezere river, increasing the risk of contamination of one of the most important hydrographic basins in central Portugal. Herein, a multidisciplinary study including geophysics, geochemistry and borehole information, organized in a GIS, is used to characterize the Rio tailings. The geophysical survey comprised ERT (Electrical Resistivity Tomography) and GPR (Ground Penetrating Radar) on the mud impoundment, as well as, on the slope of the tailings. The geochemical survey consisted on collecting water and tailings samples, iron coatings, arsenopyrite stockpile material and ferruginous crust. Samples collected in boreholes, drilled specifically for this project, were also analyzed. The GIS provided imaging of the geophysical, geochemical and particle size spatial distribution, so that comparisons between the different data sets are easily done. Resistivity and GPR allowed bedrock positioning. GPR was able to give layering results within the tailings. Finally, comparison and correlation between geophysical and geochemical results are carried out and evaluated on the GIS platform.
- Hydrodynamics of triangular-grid arrays of floating point-absorber wave energy converters with inter-body and bottom slack-mooring connectionsPublication . Vicente, Pedro C.; Falcão, António F. de O.; Gato, L.M.C.; Justino, Paulo AlexandreIt may be convenient that dense arrays of floating point absorbers are spread-moored to the sea bottom through only some of their elements (possibly located in the periphery), while the other array elements are prevented from drifting and colliding with each other by connections to adjacent elements. An array of identical floating point absorbers located at the grid points of an equilateral triangular grid is considered in the paper. A spread set of slack-mooring lines connect the peripheric floaters to the bottom. A weight is located at the centre of each triangle whose function is to pull the three floaters towards each other and keep the inter-body moorings lines under tension. The whole system – buoys, moorings and power take-off systems – is assumed linear, so that a frequency domain analysis may be employed. Equations are presented for a set of three identical point absorbers. This is then extended to more complex equilateral triangular grid arrays. Results from numerical simulations, with regular and irregular waves, are presented for the motions and power absorption of hemispherical converters in arrays of three and seven elements and different mooring and PTO parameters, and wave incidence angles. Comparisons are given with the unmoored and independently-moored buoy situations.
- Recursos minerais na Região do Alentejo : potencial e ordenamento do territórioPublication . Catrapona, Afonso; Carvalho, Jorge
- Recursos geológicos e o ordenamento do território : o exemplo do PDM de BragançaPublication . Pinto de Meireles, Carlos Augusto
- Composition and biological activity of the essential oil peruvian lantana camaraPublication . Benites, Julio; Moiteiro, Cristina; Miguel, Graça; Rojo, Leonel; Lopez, José; Venâncio, Florência; Ramalho, Luís; Feio, Sónia; Dandlen, Susana; Casanova, Hugo; Torres, IvanThe composition of the essential oil from Lantana camara L. (Verbenaceae) obtained by hydrodistillation of the aerial parts was examined by GC, GC/MS, and 13C-NMR. The GC analysis showed that carvone is the most abundant monoterpene 75.9%, together with limonene 16.9%, accounting for 92.8% of the oil. The major components were also tested by 13C-NMR analysis of the essential oil. The L. camara oil was assayed against several microorganisms, showing moderate antibacterial activity against the human pathogen Staphylococcus aureus (MIC 200 μg/ml). High antioxidant activity evaluated by the Trolox equivalent antioxidant capacity assay (TEAC) was found (29.0 mmol Trolox/kg) and relative low anti-inflammatory activity due to its weak ability for inhibiting lipoxygenase (IC50 = 81.5 μg/ml).
- Inventário do património geológico do concelho de Vila Velha de Ródão : contributo para a caracterização do Geopark Naturtejo da Meseta MeridionalPublication . Carvalho, Carlos Neto; Rodrigues, Joana; Metodiev, DanielCom a recente classificação do Monumento Natural das Portas de Ródão e a eminente revisão do Plano Director Municipal de Vila Velha de Ródão, o inventário do património geológico do Geopark Naturtejo da Meseta Meridional, em fase de enquadramento no Inventário do Património Geológico de Portugal, é visto como uma ferramenta fundamental para o ordenamento do concelho de Vila Velha de Ródão. Os 25 locais e áreas de interesse geológico e mineiro são caracterizados, apresentando-se ainda propostas de protecção e valorização individualmente. Algumas destas propostas têm aplicações práticas no desenvolvimento de actividades educativas para a comunidade escolar de Vila Velha de Ródão e como factor de atracção do público escolar peninsular. O desenvolvimento de projectos turísticos fundamentados no património geológico e arqueológico (incluindo o mineiro), aqui reunidos, permitirá uma diferenciação turística sustentada ao nível dos macronichos Turismo de Natureza e Touring Cultural.
- Alterações pedogenéticas de idade indeterminada : Paleogénico-QuaternárioPublication . Dias, Ruben Pereira; Barbosa, Bernardo; Pais, João; Azerêdo, Ana Cristina; Pimentel, Nuno; Cabral, Maria Cristina
- Argemela, a high-tonnage Sn-Li deposit in Central Portugal [Abstract]Publication . Inverno, Carlos; Ferraz, Paulo J. V.
- Synthesis, spectroscopy, photophysics and thermal behaviour of stilbene-based triarylamines with dehydroabietic acid methyl ester moietiesPublication . Gigante, Bárbara; Esteves, M. Alexandra; Pires, N.; Davies, Matthew L.; Douglas, Peter; Fonseca, Sofia M.; Burrows, Hugh D.; Pina, João; Melo, João Seixas deNovel stilbene-based triarylamines with dehydroabietic acid methyl ester moieties have been synthesised by palladium catalysed C–N coupling reactions. The presence of the bulky dehydroabietic acid group increases solubility, hinders crystallisation and permits their sublimation while preserving their electronic and optical characteristics. This makes them good candidates for various molecular electronic applications. We report a detailed characterisation of their electrochemical, spectroscopic and photophysical properties. In addition, the thermal stability and behaviour is discussed with reference to the potential for preparation of stable thin films.
- Distribuição de estanho em solos e em estevas da área envolvente das minas de Neves CorvoPublication . Batista, Maria Joao; Abreu, Maria Manuela; Pinto, M. Serrano