37 research outputs found

    A combined theoretical and experimental study of electronic structure and optical properties of β-ZnMoO4 microcrystals

    Get PDF
    In this paper, a combined theoretical and experimental study on the electronic structure and photoluminescence (PL) properties of beta zinc molybdate ( -ZnMoO4) microcrystals synthesized by the hydrothermal method has been employed. These crystals were structurally characterized by means of X-ray diffraction (XRD), Rietveld refinement, Fourier transform Raman (FT-Raman) and Fourier transform infrared (FT-IR) spectroscopies. Their optical properties were investigated by ultraviolet-visible (UV-vis) absorption spectroscopy and PL measurements. First-principles quantum mechanical calculations based on the density functional theory at the B3LYP calculation level have been carried out. XRD patterns, Rietveld refinement, FT-Raman and FT-IR spectra showed that these crystals have a wolframite-type monoclinic structure. The Raman and IR frequencies experimental results are in reasonable agreement with theoretically calculated results. UV-vis absorption measurements shows an optical band gap value of 3.17 eV, while the calculated band structure has a value of 3.22 eV. The density of states indicate that the main orbitals involved in the electronic structure of -ZnMoO4 crystals are (O2p-valence band and Mo 4d-conduction band). Finally, PL properties of -ZnMoO4 crystals are explained by distortions effects in octahedral [ZnO6] and [MoO6] clusters and inhomogeneous electronic distribution into the lattice with the electron density map

    Distribution of black flies (Diptera: Simuliidae) in the State of Espírito Santo, Brazil

    Get PDF
    Entre os anos de 2004 e 2008 foram realizadas coletas de Simuliidae em várias localidades no Estado do Espírito Santo, Brasil. No total, 66 córregos e rios das doze principais bacias hidrográficas do estado foram amostrados. Dezessete espécies foram coletadas, sendo que nove delas representam ocorrências novas para o estado (Simulium pertinax, S. jujuyense, S. rubrithorax, S. subnigrum, S. travassosi, S. spinibranchium, S. hirtipupa, S. lutzianum e S. anamariae), duplicando o número de espécies conhecidas no estado.We conducted a freshwater survey from 2004 to 2008 in several localities of Espírito Santo, Brazil. In total, 66 streams and rivers were sampled in the 12 hydrographic basins of the state. We collected and identified 17 species of which nine represent new records (Simulium pertinax, S. jujuyense, S. rubrithorax, S. subnigrum, S. travassosi, S. spinibranchium, S. hirtipupa, S. lutzianum e S. anamariae). These findings doubled the number of records of black fly species to the State of Espírito Santo, Brazil

    Vascular Flora Of The Legado Das Águas, Reserva Votorantim, Municipalities Of Tapiraí, Miracatú And Juquiá, São Paulo, Brazil

    Get PDF
    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)We present a list of vascular plants found in Legado das Águas, Reserva Votorantim, a private reserve having an area of approximately 35,000 ha that spans the municipalities of Tapiraí, Miracatú, and Juquiá, in the state of São Paulo, Brazil. The reserve is part of a complex of state-protected areas including Alto Ribeira Touristic State Park, Intervales State Park, Carlos Botelho State Park, Jurupará State Park, and Serra do Mar State Park. Together, these form an important and large area of continuous and well-preserved forest. Our study, which involved two main floristic surveys in March/April 2013 and April 2014, recorded 768 species, representing 131 families and 432 genera. The majority of species were angiosperms (619) representing 106 families and 370 genera. There were also two species of gymnosperms belonging to two genera in separate families; 147 species of ferns and lycophytes belonging to 23 families and 60 genera. In demonstrating the presence of almost 800 species of plants, of which 16 are threatened, our study highlights the importance of floristic surveys and the critical role of private protected areas in managing and preserving native flora. © 2016 Check List and Authors.1262011/22923-8, FAPESP, Fundação de Amparo à Pesquisa do Estado de São Paulo2015/9444-4, FAPESP, Fundação de Amparo à Pesquisa do Estado de São PauloFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

    Tectonics and sedimentation of the central sector of the Santo Onofre rift, north Minas Gerais, Brazil

    Full text link

    Polycystic hydatid disease in Brazil: report of five new human cases and a short review of other published observations

    No full text
    This paper describes five additional Brazilian human cases of polycystic hydatid disease due to Echinococcus vogeli, reviews the previous cases reported in Brazil, including one report of E. oligarthus (20 in total), and some epidemiological aspects of this disease which is no longer a curiosity but rather a problem that is not medically easy to handle. Its presence should be expected in any rural area of the New World where humans have not eliminated wild felids/canids, bush dogs, pacas, agoutis and other wild rodents
    corecore