Browsing by Author "Ferreira, A."
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- CHRONIBERIA : ongoing development of a geochronological GIS database of IberiaPublication . Lopes, C.; Ferreira, A.; Chichorro, Martim; Pereira, Manuel Francisco Costa; Almeida, J. A.; Solá, A. Rita
- Chroniberia : the ongoing development of a geochronological GIS database of IberiaPublication . Lopes, C.; Ferreira, A.; Chichorro, Martim; Pereira, M. Francisco; Almeida, J. A.; Solá, A. Rita
- Decipher a multi-event in a non-complex set of detrital zircon U-Pb agesPublication . Ferreira, A.; Lopes, C.; Chichorro, Martim; Pereira, Manuel Francisco Costa; Solá, A. Rita
- Deciphering a multi-event in a non-complex set of detrital zircon U-Pb ages from Carboniferous graywackes of SW IberiaPublication . Ferreira, A.; Lopes, C.; Chichorro, Martim; Pereira, M. Francisco; Solá, A. RitaThe determination of U–Pb ages from detrital zircons of sedimentary rocks using LA-ICP-MS has been widely used for the purpose of provenance analysis. One problem that frequently arises is finding a population that appears to be non-complex despite several perceptible age peaks in its spectrum. These peaks are qualitatively defined by means of relative probability diagrams, or PDFs, but it is difficult to quantify their statistical significance relative to a zircon forming multi-event. Thus, can a multi-event in a non-complex set of detrital zircon U–Pb ages be deciphered and characterized? The aim of this study is to attempt to provide an answer to this question by means of statistical analysis. Its objectives are: a) to determine the best minimum number of zircon age populations (peaks), BmPs, b) for the characterization of each peak in terms of age and event duration; c) to compare the results obtained from two datasets showing similar zircon ages; and d) to demonstrate the usefulness of deciphering these BmPs. First, cluster analysis is carried out, aimed at grouping zircon ages into a set of consistent clusters. A Gaussian Kernel function is then fitted to each cluster and summed to obtain a theoretical PDFm (modeled probability density function). Finally, the selected modeled PDFm (that built on the BmPs) is that which reports the lowest number of peaks for which the difference as compared with the original gPDF (global probability density function) is equal to or below 5%. Deciphered BmP peaks can be characterized and used for characterizing and providing an understanding of related event(s). A geological interpretation, based on the results obtained, is attempted. This includes a robust measure for maximum age of deposition for both Cabrela and Mértola graywackes.
- Deciphering a multipeak event in a noncomplex set of detrital zircon U-Pb agesPublication . Ferreira, A.; Lopes, C.; Chichorro, Martim; Pereira, M. Francisco; Solá, A. Rita
- Heavy metal pollution in Mine-Soil-Plant System in S. Francisco de Assis - Panasqueira mine (Portugal)Publication . Melo, Rita; Candeias, Carla; Ávila, Paula Freire; Salgueiro, Ana Rita; Ferreira, A.; Silva, Eduardo Ferreira da
- Intra-crustal recycling and crustal-mantle interactions in North Gondwana revealed by oxygen isotopic composition of Neoproterozoic to Ordovician zircons from SW Iberia rocksPublication . Chichorro, Martim; Solá, A. Rita; Pereira, M. Francisco; Sánchez-García, Teresa; Ferreira, A.; Silva, J. Brandão; Armstrong, R.
- Intra-crustal recycling and crustal-mantle interactions revealed by oxygen isotopic composition of SW Iberia rocksPublication . Chichorro, Martim; Solá, A. Rita; Pereira, M. F.; Ferreira, A.; Sánchez-García, Teresa; Silva, J. B.; Williams, Ian S.; Armstrong, R. A.
- Late Holocene climate variability in the Tagus prodelta, Portugal : benthic foraminiferal perspectivePublication . Bartels-Jónsdóttir, Helga B.; Knudsen, Karen L.; Abrantes, Fátima; Eiríksson, J.; Ferreira, A.; Gil, Isabelle M.; Lebreiro, Susana; Rodrigues, Teresa
- Treatment and reutilization of effluents: one Mediterranean projectPublication . Duarte, José Cardoso; Mateus, Marta; Eusebio, Ana; Almeida-Vara, Elsa; Ribeiro, Belina; Baeta-Hall, Lina; Hassani, Lahcen; Nejmeddine, Ahmed; Moreira, C.; Sukan, Fazilet; Sayadi, Sami; Federici, F.; Gónzalez López, J.; Ferreira, A.; Fenice, M.The problematic of effluent treatment from olive oil industry as been the subject of an European Commission funded project (INCO-MED programme): “Mediterranean Usage of Biotechnological Treated effluent Water”. The potential that effluent offers to increase the availability of water, in mediterranean regions, was the final goal of the project, co-ordinated by INETI with partners from EU and MPC. In the project different systems for the treatment of this effluent had been studied: reactors systems (Intensive type) based on the jet-loop principle (JACTO) and an anaerobic UASB hybrid type reactor technology; lagoons (extensive type) for municipal wastewater treatment were also applied. The aerobic JACTO system demonstrated high unit capacity for biological conversion and operation at different loadings, allowing the removal of the pollutant organic load and the toxicity associated with this effluent. The use of this type of reactor for pre-treatment of OOWW prior to disposal on a lagoon system was tested at FSS (Morocco). Use of fungi as a pre-treatment was tested by UNITUS (Italy), EBC (Turkey) and CBS (Tunisia). In this way the effluent could be “improved” as demonstrated in the case of anaerobic digestion and biogas production (CBS). Effluent improvement and enrichment with phosphate was also tested by UNITUS. Analytical monitoring methodologies were developed at IA (Spain) and treated effluents were tested for a number of agricultural applications in different countries. The different alternatives studied will be analysed and compared taking account of technological and socio-economical criteria in relation with the project objectives.