Caracterização estrutural e paragenética do Campo Pegmatítico do Licungo (Mocuba, Moçambique): identificação de recursos base associados

Publicado em "A engenharia no combate à pobreza, pelo desenvolvimento e competitividade", ISBN 978-972-8826-19-2Geological thematic mapping in Licungo pegmatite field (Mocuba, Mozambique) has clarified the distribution of mineral resources in NYF hyperaluminous pegmatites and revealed its structural control. Two distinct spatial and deformational areas can be distinguished. In the north structural domain, large pegmatites are associated with early tangential tectonic. Besides feldspar with ceramic qualification, industrial beryl and gems are also non-systematic resources. Small pegmatite dykes predominate in the south domain and their emplacement is conditioned by later distensive phases (Dn+1 and Dn+2). Their economic interest comes from gem beryl enrichment and its crystallisation as true-blue varieties

Micronucleus test and comet assay in erythrocytes of the Amazonian electric fish Apteronotus bonapartii exposed to benzene

In this study we address the genotoxicity and putative mutagenic effects of benzene (BZN) in the erythrocytes of the electric fish Apteronotus bonapartii (Gymnotiformes, Apteronotidae) using the micronucleus test (MN) and comet assay, under controlled laboratory conditions. Electric fish were collected in the Solimões River, Manaus-AM, Brazil, and the specimens were exposed to 10 and 25 ppm concentrations of BZN, in 150L tanks. Blood samples were collected at 0 (T0), 24, 48, 72 and 96 hours of exposure. For the concentration of 10 ppm BZN, the number of comets was significantly higher than T0 levels after exposure of 48 hours, whereas the nuclear abnormalities (including MN) did not show any increase in relation to the controls (T0) up to 96 hours. For the 25 ppm BZN, MN rates presented a significant increase after 72 hours, whereas other types of nuclear abnormalities increased in frequency after various exposure times, ranging from 24 to 72 hours. The number of comets increased significantly from 24 hours onwards for 25 ppm BZN. Both assays also showed a gradual increase in the number of damaged cells after longer exposure periods, indicating a time-dependent effect, especially at the highest BZN concentrations tested. This investigation reinforces the potential use of the endemic South American electric fish as a suitable genotoxicity biological model for biomonitoring purposes in the Amazon. Keywords: Comet assay, Micronucleus test, Apteronotus bonapartii, Benzene, Biomonitoring, Electric fish, Amazo

Human case of West Nile neuroinvasive disease in Portugal, summer 2015

A case of West Nile virus (WNV) infection was reported in the Algarve region, Portugal, in the first week of September 2015. WNV is known to circulate in Portugal, with occasional reports in horses and birds (2004 to 2011) and very sporadically human cases (in 2004 and in 2010). Here we present the clinical and laboratory aspects related to the first human case of West Nile neuroinvasive disease reported in Portugal

Levantamento arqueológico do Algarve: concelho de Lagoa

O Concelho de Lagoa, apesar da sua apreciável riqueza arqueológica, onde se destaca a estação pré-histórica de Caramujeira, descoberta em 1974 e cujos menires são hoje conhecidos do mundo científico, não se têm nele processado trabalhos de investigação que o valorizem. São excepção as pequenas escavações realizados no Ilhéu do Rosário, em meados do passado século e sob orientação de Estácio da Veiga, em Ferragudo e na Gruta de lbn Amar (Mexilhoeira), ainda quase inéditas, apesar de terem sobre elas decorrido mais de vinte e cinco anos, ou as breves campanhas verificadas na Caramujeira. De facto, os conhecimentos disponíveis sobre o seu património arqueológico resultam, sobretudo, de alguns achados ocasionais, das prospecções de Estácio da Veiga , das que um de nós procedeu nos anos setenta (M.V.G.), e das agora efectuadas e a que se somaram muitas informações dispersas, tendo em vista a elaboração do presente estudo.info:eu-repo/semantics/publishedVersio

On spin-1 massive particles coupled to a Chern-Simons field

We study spin one particles interacting through a Chern-Simons field. In the Born approximation, we calculate the two body scattering amplitude considering three possible ways to introduce the interaction: (a) a Proca like model minimally coupled to a Chern-Simons field, (b) the model obtained from (a) by replacing the Proca's mass by a Chern-Simons term and (c) a complex Maxwell-Chern-Simons model minimally coupled to a Chern-Simons field. In the low energy regime the results show similarities with the Aharonov-Bohm scattering for spin 1/2 particles. We discuss the one loop renormalization program for the Proca's model. In spite of the bad ultraviolet behavior of the matter field propagator, we show that, up to one loop the model is power counting renormalizable thanks to the Ward identities satisfied by the interaction vertices.Comment: 14 pages, 5 figures, revte

Ultrasound-assisted casting of AZ91D-1.5%Ca – Shifting T4 paradigm for downstream processing

Available online 8 October 2022The effect of the as-cast microstructure on solution treatment of AZ91D-1.5%Ca was investigated. Ultrasound treatment was applied during the casted alloy's cooling, promoting the refinement of alpha-Mg and /9-Mg17Al12 phases. Fine and divorced /9-phase was found in the ultrasound-treated sample, resulting in a superior dissolution rate of this intermetallic during subsequent solution treatment. The results indicate that tailoring the as-cast microstructure may be a route for optimizing the solution treatment necessary for downstream plastic defor-mation processes. The solution treatment's duration and temperature may be decreased, making the process economically and ecologically sustainable.National funds supported this work through the research doctoral Grant PD/BD/140094/2018 and under R&D unit with reference project UIDB/04436/2020