Electron microprobe analysis of cryolite

Comunicação apresentada em: EMAS 2013 : 13th European Workshop on Modern Developments and Applications in Microbeam Analysis, Centro de Congressos da Alfândega do Porto, Portugal, 12 to 16 May 2013A sample of cryolite was studied with a JEOL JXA 8500-F electron microprobe under several operating conditions. A TAP crystal was used to analyse Na and Al and a LDE1 crystal to analyse F. As F and Na are both highly "volatile" elements, special care must be taken during analysis. The measurement order of Na, F and Al is not irrelevant and optimum conditions may also result in different combinations of accelerating voltage, beam current, beam size or counting times. Relevant X-ray signals were recorded in order to investigate the behaviour of the Na Ka and F Ka counts with elapsed time. The incident beam current was also recorded at the same time. In a clear contrast to what has normally been reported in the EPMA analysis of aluminosilicates and silicate glasses, we found that the Na X-ray counts increase with time. This increment of X-rays intensities for sodium in cryolite depends on the operating conditions and is accompanied by a strong migration of fluorine from the beam excitation volume, leading to a decrease in F X-ray counting rates. It was also observed that higher incident beam currents induce higher radiation damage in the mineral. The current instability is consistent with possible electron induced dissociation in the cryolite structure. An analytical protocol was achieved for 6 kV and 15kV accelerating voltage for the correct EPMA analysis of cryolite

Geochemistry of minerals, waters and weathering from the Fonte Santa mine area, NE of Portugal

The quartz veins containing scheelite from Fonte Santa mine area were exploited for W between 1942 and 1982. At the end of November 2006, a flood event damaged the dam land of Fonte Santa mine and metal content of water increased. Fonte Santa mine area cuts the quartzites close to the Fonte Santa muscovite granite. The granite contains quartz, microcline, albite, muscovite, chlorite, columbite-tantalite, volframite, W-ixiolite and ilmenite. The quartz veins contain muscovite, chlorite, tourmaline, scheelite, pyrrhotite, pyrite, sphalerite, chalcopyrite, galena, arsenopyrite, magnetite, jarosite, phosphates of Pb, Fe and AI. The waters related to the Fonte Santa mine are poorly mineralized, with electrical conductivity < 965 ~S / cm, of mixed type or HCO3- and SO42- types. These waters have Fe and Mn contents that forbid to use that for human consumption and agriculture. Sodium, Mg and K water contents are associated with the alteration of albite, chlorite and muscovite of country rock, while Ca is related to the W-bearing quartz veins

Febrile Seizures. Association with HHV6 and CMV Infection?

Febrile seizures (FS) occur between the age of 1 and 60 months, with fever, are generalized and usually lasting less than 15 minutes. The etiology of FS is not known, although infections, immunizations and genetic susceptibility, all have been linked to an increased risk of FS. Herpes virus 6 (HHV6) and Cytomegalovirus (CMV) are neurotropic virus and remain latent after a primary infections. 10 to 50% of FS cases in children are associated with HHV6 primary infection. An association between FS and CMV infection has not been established.info:eu-repo/semantics/publishedVersio

Criação e manutenção de colônias de Ceratitis capitata e Anastrepha obliqua para estudos de biologia e ecologia da praga na Bahia.

As moscas-das-frutas são consideradas pragas agrícolas de uma extensa variedade de frutíferas apresentando algumas características biológicas que as favorecem, como elevado potencial biótico, habilidade de se dispersarem no meio ambiente e de se adaptarem a novos hospedeiros (GALLO et al., 1993). Essas espécies são responsáveis por danos diretos e indiretos, sendo consideradas um dos principais problemas fitossanitários da fruticultura brasileira e mundial (MORGANTE, 1991).Em paralelo aconteceram também os seguintes eventos: V Seminário de Pesquisa do Recôncavo da Bahia; V Seminário Estudantil de Pesquisa da UFRB; V Seminário da Pós-Graduação da UFRB; II Seminário Regional de Pesquisa da EBDA; 5ª Jornada Científica da Embrapa Mandioca e Fruticultura; VIII Seminário Estudantil de Pesquisa e Extensão da FAMAM; Semana de Ciência, Tecnologia e Inovação no Agronegócio; Fórum de Gestores de Iniciação Científica e Tecnológica da Bahia; II Simpósio Baiano de Defesa Agropecuária; I Semana de Educação Tutorial da UFRB