Encontrados 12 documentos, a visualizar página 1 de 2
Contribuição dos sistemas isotópicos Sm-Nd e Rb-Sr para o estudo petrogenético ...
Almeida, A.; Santos, J. F.; Noronha, F.O Granito do Porto corresponde a um granito hercínico, leucocrata, de duas micas, fortemente peraluminoso. No presente trabalho foram realizadas análises para os sistemas isotópicos Rb-Sr e Sm-Nd, em cinco amostras frescas do granito em estudo. Obteve-se uma isócrona Rb-Sr de 306±7 Ma (MSWD=0,71; 87Sr/86Sr inicial=0,7128), que dentro da margem de erro, deverá refletir a instalação magmática. Em termos de geoquí...
Emplacement of the Lavadores granite (NW Portugal): U/Pb and AMS results
Martins, H C. B.; Santovaia, Helena; Abreu, J.; Oliveira, M.; Noronha, F.Studies of Anisotropy of Magnetic Susceptibility (AMS) and U-Pb geochronology, in zircon fractions, were carried out in a magnetite type-granite, the Lavadores granite, which is an example of a late to post-orogenic Variscan granite in northern Portugal (NW Iberian Peninsula). The U-Pb zircon analyses yield an age of 298 +/- 11 Ma that is considered to be the emplacement age of this granite and thus suggesting ...
Estudo da microfracturação do maciço granítico de Castelo Branco através dos Pl...
Dória, A.; Morais, P.; Santos, M.; Gomes, C. R.; Sant'Ovaia, H.; Noronha, F.O principal objectivo deste trabalho consistiu na determinação da geometria dos PIF, no maciço granítico de Castelo Branco. Este estudo mostrou que para além de PIF em Modo I, também estão presentes em Modo II, sugerindo que as orientações encontradas NE-SW a NNE-SSW e E-W a ESEWNW podem ser interpretadas como conjugados relacionados com uma tensão máxima (σ1) orientada NE-SW. A orientação NNW-SSE corresponde a...
Genesis and emplacement of felsic Variscan plutons within a deep crustal lineat...
Martins, H C. B.; Santovaia, H.; Noronha, F.Multidisciplinary studies integrating, U-Pb geochronology, whole-rock geochemical data, isotope geochemistry, anisotropy of magnetic susceptibility (AMS) studies and gravimetry were carried out on the Vila Pouca de Aguiar and the Aguas Frias-Chaves porphyritic biotite granite plutons. Both plutons occur independently in a distance of about 20 km. The Vila Pouca de Aguiar and Aguas Frias-Chaves plutons are examp...
Definition of the Portuguese frameworks with international relevance as an inpu...
Bilha, J.; Andrade, C.; Azerêdo, Ana C.; Barriga, F.; Cachão, M.; Cunha, P. P.; Crispim, J. A.; Dantas, P.; Duarte, L. V.; Freitas, M.C.; Granja, M. H.This work constitutes the first contribution for the systematisation of the geological heritage knowledge in Portugal, following the international recomendations for the characterisation of geological heritage (IUGS, ProGEO). The application of the ProGEO methodology has resulted on the creation of fourteen frameworks with international relevance, established by consensus among the Portuguese geological communi...
Definition of the Portuguese frameworks with international relevance as an inpu...
Brilha, J.; Cunha, Pedro P.; Azerêdo, A.; Barriga, F. J. A. S.; Azeredo, A.; Cachão, M.; Couto, H.; Andrade, C.; Crispim, J. A.; Dantas, P.This work constitutes the first contribution for the systematisation of the geological heritage knowledge in Portugal, following the international recomendations for the characterisation of geological heritage (IUGS, ProGEO). The application of the ProGEO methodology has resulted on the creation of fourteen frameworks with international relevance, established by consensus among the Portuguese geological communi...
Characterization of steam-reforming catalysts
Santos,D. C. R.M.; Lisboa,J. S.; Passos,F. B.; Noronha,F. B.The effect of the addition of Mg and Ca to Ni/ a-Al2O3 catalysts was investigatedstudied, aiming to detail the promotion mechanismaddress their role as promoters in the steam reforming reaction. Temperature- programmed reduction and H2 and CO temperature-programmed desorption experiments indicated that Mg interacts with the metallic phase. Mg-promoted catalysts showed a greater difficulty for Ni precursors redu...
Comparison of two different synthesis methods of perovskites, SrCo0.5FeO3 type,...
Noronha,F.B.; Mattos,L.V.; Souza,H.P. de; Morelli,M.R.; Passos,F.B.; Greca,Maria ConceiçãoIn this work two different synthesis methods of perovskites, SrCo0.5FeO3, were compared: combustion synthesis and oxides mixture aiming at evaluating their use as membranes for partial oxidation of methane. The combustion synthesis method explores an exothermic, generally very fast and self-sustaining chemical reaction between the desired metal salts and a suitable organic fuel, which is ignited at a temperatur...
Projeto Parque Frei Veloso: levantamento detalhado dos solos do Campus da Ilha ...
SANTOS, R. D.; AGAREZ, F. V.; NORONHA, F.2000
EXAFS as a tool for catalyst characterization: a review of the data analysis me...
NORONHA,F. B.A review of the EXAFS data analysis methods is presented. A detailed description of the EXAFS signal extraction and the Fourier transform of the data are discussed. The procedure for determining interatomic distances, coordination numbers and disorder effects from EXAFS data is described. This paper also discusses the data analysis statistics. Finally, one example of catalyst characterization by the EXAFS techn...
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