Elementos de geoquímica das rochas do maciço ígneo de Sines

The chemical and mineralogical characteristics of the intrusive and extrusive rocks of this igneous complex are presented. The suggest affinities between these rocks. The major and the trace elements lead us to conclude that these rocks were originated in a common magmatic chamber by fractional crystallization

Elementos de geoquímica das rochas do maciço ígneo de Sines

The chemical and mineralogical charactetistics of the intrusive and extrusive rocks of this igneous complex are presented. The suggest affinities between these rocks. The major and the trace elements lead us to conclude that these rocks were originated in a common magmatic chamber by fractional crystallization

Contribuição para o conhecimento petrográfico e geoquímico do maciço ígneo de Benavila (Avis)

The igneous rocks of Benavila area consist predominantly of granodiorite and monzonitic granite. Chemically they exhibit typical calco-alkaline differentiation trends and appear to represent a co-magmatic series on the basis of major - and trace - element geochemistry. There is a lot of somewhat more basic igneous enclaves

Nota sobre a constituição dos muros de uma das fábricas de salga da Ilha do Pessegueiro

Dos resultados apresentados, verifica-se que a larga maioria das rochas utilizadas na construção dos tanques da fábrica de salga são xistos e grauvaques, do Carbonífero marinho de fácies " flysch", mais ou menos alterados, cuja proveniência poderia ser a própria área fronteira à ilha. Em alguns casos, torna-se difícil a separação destas rochas de outras, igualmente siliciosas e esverdeadas, que ocorrem na arriba litoral adjacente: trata-se de tufos ácidos riolíticos e quartzo-queratofíricos, e felsitos (d. Carta Geológica de Portugal na escala de 1/200 000, Folha 7) .info:eu-repo/semantics/publishedVersio

Ânforas da Villa Romana de Vilares de Alfundão (Ferreira do Alentejo)

Os autores estudam um conjunto anfórico recolhido nos restos conservados à superfície de uma villa romana, Vilares de Alfundão (Ferreira do Alentejo). Da análise tipológica e do estudo das pastas cerâmicas, conclui-se que a maioria terá sido fabricada nos fornos do Baixo Sado, predominando largamente as formas Dressel 14b e Almagro 51c. Tais resultados são comparados e discutidos, especialmente com os obtidos do estudo das ânforas de S. Cucufate (Vidigueira). Em dois fundos de ânforas DresseI 14 aparece o mesmo grafito e um dos exemplares da forma Almagro 50 ostenta na asa a marca [ . .. ] CVRVCVNIN

Effect of morphology and hydrophobization of MoS2 microparticles on the stability of poly-α-olefins lubricants

International audienceThe use of MoS ⁠ 2 nanoparticles as additive to lubricating oils is restricted by their low stability in oily media, which limits their use despite the enormous benefits associated with their intrinsic properties in terms of reduction of friction and wear coefficients. In this context, we investigated the effect of morphologies (platelets vs spheres) and surface functionalization of nanoparticles on the stability of their suspensions in poly-α-olefins (PAO) with various viscosities, which are base oils used in wind turbines. The particles were characterized by XRD, FTIR, scanning electron microscopy, atomic force microscopy and dynamic light scattering, and the stability of the resultant formulations was followed by optical (non-contact) measurements. It was found that the dispersions had similar stability despite the larger size of platelet-like particles compared to spherical ones (1-5 μm vs 600-800 nm). The dispersibility could be increased through grafting of alkylsilane on the surface defects (the longer the alkyl chain, the more stable the formulation) and with the increase of the oil kinematic viscosity (from 34 to 1705 cps at 25 °C)

A Portuguese East Indiaman from the 1502-1503 Fleet of Vasco da Gama off Al Hallaniyah Island, Oman: An interim report

Two Portuguese naus from Vasco da Gama's second voyage to India, left behind to disrupt maritime trade between India and the Red Sea, were wrecked in May 1503 off the north-eastern coast of Al Hallaniyah Island, Oman. The ships, Esmeralda and São Pedro, had been commanded by da Gama's maternal uncles, Vicente and Brás Sodré, respectively. A detailed study and scientific analysis of an artefact assemblage recovered during archaeological excavations conducted in Al Hallaniyah in 2013 and 2014 confirms the location of an early 16th-century Portuguese wreck-site, initially discovered in 1998. Esmeralda is proposed as the probable source of the remaining, un-salved wreckage

O pórfiro dacítico de Valverde (Alcácer do Sal) idade Rb-Sr e suas implicações

The unexpected discovery of a small outcrop of igneous rock isolated within an extensive outcrop of Neogene and Quaternary sediments called for the attention of CEPUNL's researchers. The rock is a dacite whose Rb-Sr age (C. A. and M. H. C.) is 291 M. y. upper Carboniferous. Hence the dacite may be related to volcanism in the Santa Suzana tectonic basin