47 documents found, page 1 of 5
Stream sediments geochemistry in the Valongo anticline, northern Portugal: arse...
Carvalho, Paula; Albuquerque, Teresa; Chambel, Luís; Silva, Manuela; Rocha, FernandoABSTRACT: The Valongo anticline is known for the occurrence of several Sb-Au and As-Au mineral deposits, many of which have been exploited since Roman times. The Sb-Au and As-Au deposits occur in brecciated quartz veins, predominantly trending NE-SW, NNW-SSE, and ENE-WSW, cutting Cambrian to Carboniferous formations. An 801-stream sediment campaign was conducted in this area. Factorial kriging was applied as an...
Stream sediment pollution: a compositional baseline assessment
Albuquerque, Teresa; Fonseca, Rita; Araújo, Joana; Silva, Natália; Araújo, AntónioA high concentration of potentially toxic elements (PTEs) can affect ecosystem health in many ways. It is therefore essential that spatial trends in pollutants are assessed and monitored. Two questions must be addressed when quantifying pollution: how to define a non-polluted sample and how to reduce the problem’s dimensionality. A geochemical dataset is a composition of variables (chemical elements), where the...
O Rivermead Mobility Index é o instrumento de medida mais completo para avaliar...
Santos, Hugo; Martins, Maria Elisabete; Brandão, Rita; Baleia, Isabel; Santos, Beatriz; Gonçalves, Inês; Peixoto, Isabel; Costa, Sarantrodução: O Acidente Vascular Cerebral (AVC) é a principal causa de incapacidade a longo prazo da população mundial. As alterações estruturais e funcionais consequentes da condição contribuem para a redução da mobilidade funcional (MF), tornando-se fundamental a sua avaliação com instrumentos de medida (IM) adequados e fundamentados, permitindo uma prática clínica mais objetiva e rigorosa. Objetivos: Investiga...
Environmental factors and metals mobilisation in alluvial sediments - Minas Ger...
Fonseca, Rita; Pinho, Catarina; Albuquerque, Teresa; Araújo, JoanaIn areas contaminated by potentially toxic elements (PTEs), knowledge of processes of metal mobilisation is the basis for the choice of appropriate remediation methodologies. The mobilisation of metals is a function of several factors and the response to these factors must be well known during the planning of remediation strategies. The activity of an ore metallurgical plant in SE Brazil resulted in major conta...
Evaluating the Effectiveness of Nanotechnology in Environmental Remediation of ...
Fonseca, Rita; Araújo, Joana; Pinho, Catarina; Albuquerque, TeresaA column experiment at a laboratory level was carried out to assess the effect of the application of nanotechnology in the decontamination of soils and alluvial deposits with high levels of poten-tially toxic elements (PTEs). A suspension of zero-valent iron nanoparticles (nZVI) was injected at three different concentrations in selected samples (two sediments, one soil). For most of the el-ements, the retention...
Catastrophe Vulnerability and Risk Mapping in the Iron Quadrangle, Brazil – Pre...
Vicq, Raphael; Albuquerque, Teresa; Fonseca, Rita; Leite, MariangelaThe geochemistry of fluvial deposits is one of the most used proxies for contamination assessment in mined areas. A river sediment survey was carried out in Iron Quadrangle (IQ), Brazil, between 2013 and 2015. Subsequently, in the last four years, two dam failures happened, causing great environmental damage. Geostatistical modelling was used to model Potentially Toxic Elements’ spatial patterns and the definit...
Stream sediments: a compositional baseline assessment at the Caveira mine, Port...
Araújo, Joana; Fonseca, Rita; Silva, Natália; Araújo, António; Albuquerque, TeresaA high concentration of Potentially Toxic Elements (PTE) can affect ecosystem health. It is therefore essential that spatial trends of pollutants are assessed and controlled. River sediment pollution is widespread in mining communities around the world, including in developing countries. This study, as part of the GeoMaTre project, restoration of water bodies impacted by mine drainage, an ongoing collaborative ...
A Geostatistical approch for Mercury spatial patterns assessment in sediments i...
Mota, Natália; Fonseca, Rita; Araújo, Joana; Antunes, Margarida; Valente, Teresa; Barroso, Ana; Araújo, António; Albuquerque, TeresaMercury pollution is significant in many former mining communities worldwide, including in developing countries. Anthropic contributions to environmental Hg pollution are mostly connected to fuel fossil emissions, industrial and mining activities. Among mining operations, gold exploration contributes to the highest Hg contamination rates, given the processes, widely used in the past, of mixing Hg with the gold ...
Caraterização da vulnerabilidade associada a águas subterrâneas: o estudo de ca...
Albuquerque, Teresa; Roque, Natália; Rodrigues, Joana; Antunes, Isabel Margarida Horta Ribeiro; Silva, CatarinaA avaliação da vulnerabilidade dos sistemas aquíferos tornou-se uma ferramenta útil para prevenir a poluição das águas subterrâneas. Os mapas de vulnerabilidade fornecem dados valiosos para proteger os recursos hídricos subterrâneos. A identificação de modelos agrícolas é uma questão importante para uma gestão otimizada da água. O Geopark Naturtejo Mundial da UNESCO, localizado no centro interior de Portugal, i...
Prediction scenarios of past, present, and future environmental suitability for...
Almeida, Alice Maria; Martins, Maria João; Campagnolo, Manuel Lameiras; Fernandez, Paulo; Albuquerque, Teresa; Gerassis, Saki; Gonçalves, José CarlosClimate change is a challenge for forests in the coming decades, with a major impact on species adaptation and distribution. The Mediterranean Basin is one of the most vulnerable hotspots for biodiversity conservation under climate change in the world. This research aimed at studying a Mediterranean species well adapted to the region: the Arbutus unedo L. (strawberry tree). The MaxEnt, a presence-only species-d...