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- Organic Maturation and Source-Rock Potential of the Mesozoic Algarve Basin: southern PortugalPublication . Fernandes, Paulo; Borges, Marisa; Rodrigues, B.; Matos, VascoThe Algarve Basin is an important Mesozoic depocentre in southern Portugal.
- Cost-effective bioethanol production at low content of nitrogen source from carob syrupPublication . Raposo, Sara; Sousa, Catarina; Rodrigues, B.; Lima-Costa, Maria Emília; Quintas, Célia; Rodrigues, F.Ethanol, as biofuel, has received great interest in the latest decades due to its potential as an alternative transport fuel. Nowadays, ethanol can be produced through fermentative processes, using sugar rich agricultural raw material and it may have a significant role in reducing environmental impact of fossil fuels.
- História térmica da bacia carbonífera de Moatize-MinjovaPublication . Fernandes, Paulo; Cogné, N.; Marques, J. M.; Rodrigues, B.; Jorge, R. C. G. S.; Jamal, D.Duas sondagens de prospecção de carvão executadas na Bacia Carbonífera de Moatize-Minjova, foram estudadas usando as técnicas do poder reflector da vitrinite e dos traços de fissão da apatite para avaliar a sua história térmica.
- Idades U-Pb de zircões detríticos do Grupo do Flysch do Baixo Alentejo, Zona Sul PortuguesaPublication . Rodrigues, B.; Chew, Dave; Jorge, R. C. G. S.; Fernandes, Paulo; Veiga-Pires, C.; Oliveira, J. T.Foram obtidas idades U-Pb através de ablação a lazer de zircões detríticos das formações do Grupo do Flysch do Baixo Alentejo. As idades obtidas sugerem uma proveniência sedimentar, no caso das formações de Mértola e Mira, com o envolvimento de uma componente detrítica intrabasinal (Zona Sul Portuguesa) e de áreas fontes associadas ao bordo sul da Zona da Ossa Morena. No caso da Formação de Brejeira as idades sugerem um envolvimento de áreas fontes correlacionáveis com o terreno Avalonia/Meguma assim como de sedimentos reciclados oriundos do Domínio Sul Português.
- Reply to Discussion on 'Detrital zircon geochronology of the Carboniferous Baixo Alentejo Flysch Group (South Portugal); constraints on the provenance and geodynamic evolution of the South Portuguese Zone', Journal of the Geological Society, 172, 294-308Publication . Rodrigues, B.; Chew, D. M.; Jorge, R. C. G. S.; Fernandes, Paulo; Veiga-Pires, C.; Oliveira, J. T.We would like to thank Pereira (2015) for his interest in our work and appreciate the opportunity to clarify some aspects of the Rodrigues et al. (2015) study. Here we dispute several fundamental assertions made in the discussion of our original paper. (1) Pereira (2015) states, based on the U–Pb detrital zircon data of Pereira et al. (2012a, 2014), that the turbidites of the Mértola (late Visean) and the Mira (Serpukhovian to early Bashkirian) formations of the Baixo Alentejo Flysch Group of the South Portuguese Zone (Fig. 1b), were ‘mainly derived from a source terrane dominated by zircon populations of Middle–Late Devonian ages (c. 393–359 Ma) that are absent in the Ossa–Morena Zone’ and that this detrital zircon population forms 37.7% of all detrital zircons of these two formations. However, a large population of zircons of Middle–Late Devonian age was not found in the Rodrigues et al. (2015) study. The Mértola Formation (sample FM1; table 1 of Rodrigues et al. 2015) is clearly dominated by one population whose zircon ages range between 388 and 326 Ma, with this group representing 68% of all ages obtained. This population shows a peak at 336 Ma (middle Visean).
- Geochemistry and provenance of the Carboniferous Baixo Alentejo Flysch Group, South Portuguese ZonePublication . Jorge, R. C. G. S.; Fernandes, Paulo; Rodrigues, B.; Pereira, Zélia; Oliveira, José TomásThis work is focused on the turbiditic sediments from the Carboniferous Baixo Alentejo Flysch Group (BAFG) in the South Portuguese Zone, an external zone of the Iberian Variscides. The aim of this work is to constrain the provenance and tectonic setting of these sediments in a context of a complex evolution of SW Iberian Variscides. For this purpose, we performed a systematic study of petrographical and geochemical signatures of greywackes and shales from the three BAFG formations: Mértola, Mira and Brejeira. Major and trace element composition and ratios suggest heterogeneous source area composition for BAFG shales and greywackes. For the oldest Mértola Formation greywackes, source area is dominated by granitoid rocks with minor mafic input. The latter becomes residual in the Mira Formation. The youngest Brejeira Formation greywackes show clear felsic affiliation associated with an increase in recycled components. The shales of all three BAFG formations denote a granodioritic affiliation. Chemical Index of Alteration (CIA) and Plagioclase Index of Alteration (PIA) values suggest moderate weathering in the source areas of Mértola and Mira formations. These indices, together with A–CN–K relations, point out to steady-state weathering conditions in the source areas of both formations. In contrast, both CIA and PIA values for the Brejeira Formation indicate variable conditions of palaeoweathering, from moderate to intense, as a consequence of non-steady-state conditions probably triggered by tectonic instability in the provenance area. Compared to the greywackes, the shales of all three BAFG formations exhibit higher CIA and PIA values, as well as low K2O/Al2O3 (~0.2) and index of compositional variability (b1), reflecting the cumulative effect of multiple cycles of sedimentary recycling and prolonged chemical weathering history. Major and trace element distribution and upper continental crust-normalized multi-element plots suggest that the sediments of BAFG were derived mainly from a continental arc/active margin with minor contribution from old continental crust. Together, our geochemical data are compatible with BAFG sediments derived mainly from SW border of the Ossa Morena Zone (Gondwanan affinity), with possible contribution from an external (Avalonian) source.
- Bioethanol production using carob pod, as carbon source on submerged fermentationPublication . Lima-Costa, Maria Emília; Sousa, Catarina; Rodrigues, B.; Quintas, Célia; Raposo, SaraIn the latest years the research for new sources of carbon sources, among industry by-products as potential raw material for bioethanol production is a needful and a sustainable strategy for the success of 2nd generation biofuels.
- Thresholds for storm impacts on an exposed sandy coastal area in southern PortugalPublication . Almeida, L. P.; Vousdoukas, Michalis; Ferreira, Óscar; Rodrigues, B.; Matias, AnaStorms are one of the most important phenomena responsible for coastal erosion. Their destructive power presents major challenges for coastal management, and knowledge of their characteristics and associated consequences is therefore of paramount importance. In this study, thresholds for storm impacts are defined for a sandy coast in southern Portugal (Faro beach, Ria Formosa) using two different approaches: i) hydrodynamic conditions associated with historical storm impacts (i.e., infrastructural damage); and (ii) computed maximum wave run-up values (RHIGH) compared with beach morphology. Damage thresholds are defined as limits above which the action of a storm exceeds beach front response capability and starts to act directly on human infrastructures. According to method (i), four different thresholds were defined. For individual storms directed from the SW the threshold is a significant wave height of 4.7 m with a storm duration of 2 days, and for storms directed from the SE is a significant wave height of 6 m with a storm duration of at least 2 days. Regarding storm groups, for those directed from the SW the threshold is 2 storms lasting at least 2 days each with significant wave heights greater than 3.5 m, whilst for those directed from the SE the threshold is 3 short storms (lasting 1 day each) with significant wave height over 3.9 m. The return period for the SW storm group threshold is just 1.7 years. For method (ii), beach morphological parameters (DHIGH — highest elevation of the frontal dune; DLOW — elevation of the dune base; and tanβf — foreshore slope) were determined for five chosen cross-shore profiles along the study area, and RHIGH computed for different hydrodynamic conditions. Results were validated through field observations of storm impacts. The lowest thresholds for overwash are along the central part of the study area where a dune crest is absent due to human occupation. The highest thresholds for overwash are on those profiles where a frontal dune is well developed or a foredune ridge is present (western and eastern parts of the study area). This study presents a methodological strategy to compute realistic thresholds for storm impacts along Faro beach based on historical datasets of hydrodynamics and storm impacts information. The approach could be implemented in other coastal areas to provide a comprehensive assessment of the storm impact, requiring only simple information like offshore storm hydrodynamics characteristics, beach morphology and reports of coastal infrastructure damage.
- Produção de bioetanol a partir de resíduos industriais de alfarroba: cinética de inibição do etanol para diferentes concentrações do nutriente limitante. Fermentação com recirculação de células livres e células imobilizadasPublication . Rodrigues, Brígida; Costa, Maria Emília LimaO bioetanol produzido através de resíduos agroindustriais pode ser a resposta que visa solucionar parte das carências de biocombustíveis em Portugal. A alfarroba é um fruto de elevada produção no Algarve, os resíduos que resultam do processamento da alfarroba são uma potencial origem de produção de bioetanol de segunda geração. Para que a produção de bioetanol seja considerada rentável os custos de produção devem ser mantidos o mais baixos possível. Para abordar esta problemática foram realizados ensaios que determinassem qual a concentração de açúcares totais ótima para a produção de bioetanol. Foram testadas várias concentrações de açúcares de totais (20, 50, 100, 150, 200, 250, 300 e 350 g/L) utilizando extrato de alfarroba como fonte de carbono. A concentração de açúcares totais que apresentou melhor relação de rendimentos foi a 250 g/l com rendimentos próximo do teórico. Foi estudada a capacidade de recirculação celular por parte da levedura Saccharomyces cerevisiae F13A na sua forma livre realizando para tal 2 recirculações celulares. Foi possível observar que as recirculações não variam profundamente o rendimento etanol em relação ao substrato e aumentam as produtividades máximas de etanol. Verificou-se a capacidade de imobilização da levedura em quatro matrizes diferentes, alginato de cálcio, alginato de cálcio com alfarroba, luffa cylindrica e kibbles de alfarroba, e efetuaram-se ensaios de recirculação celular da levedura Saccharomyces cerevisiae F13A na sua forma imobilizada. Foi possível concluir que a matriz de imobilização com kibbles de alfarroba além de ser um meio económico, de elevada disponibilidade e fácil imobilização é um meio robusto capaz de resistir a pelo menos duas recirculações, conduzindo a produtividades e Y E/S elevados mesmo ao fim de duas recirculações.
- Nitrogen Sources Screening for Ethanol Production Using Carob Industrial WastesPublication . Raposo, Sara; Constantino, Ana; Rodrigues, F.; Rodrigues, Brígida; Lima-Costa, Maria EmíliaNowadays, bioethanol production is one of the most important technologies by the necessity to identify alternative energy resources, principally when based on inexpensive renewable resources. However, the costs of 2nd-generation bioethanol production using current biotechnologies are still high compared to fossil fuels. The feasibility of bioethanol production, by obtaining high yields and concentrations of ethanol, using low-cost medium, is the primary goal, leading the research done today. Batch Saccharomyces cerevisiae fermentation of high-density sugar from carob residues with different organic (yeast extract, peptone, urea) and inorganic nitrogen sources (ammonium sulfate, ammonium nitrate) was performed for evaluating a cost-effective ethanol production, with high ethanol yield and productivity. In STR batch fermentation, urea has proved to be a very promising nitrogen source in large-scale production of bioethanol, reaching an ethanol yield of 44 % (w/w), close to theoretical maximum yield value and an ethanol production of 115 g/l. Urea at 3 g/l as nitrogen source could be an economical alternative with a great advantage in the sustainability of ethanol production from carbohydrates extracted from carob. Simulation studies, with experimental data using SuperPro Design software, have shown that the bioethanol production biorefinery from carob wastes could be a very promising way to the valorization of an endogenous resource, with a competitive cost.
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