University Federal do Esprito Santo


University Federal do Esprito Santo

Time filter
Source Type

Miwa R.H.,University Federal Of Uberlndia | Schmidt T.M.,University Federal Of Uberlndia | Scopel W.L.,University Federal Do Esprito Santo | Scopel W.L.,Federal University of Fluminense | Fazzio A.,University of Sao Paulo
Applied Physics Letters | Year: 2011

We have performed an ab initio theoretical investigation of a graphene sheet adsorbed on amorphous SiO2 surface (G/a-SiO2). We find that graphene adsorbs on the a-SiO2 surface through van der Waals interactions. The inhomogeneous topology of the a-SiO2 clean surface promotes a total charge density displacement on the adsorbed graphene sheet, giving rise to electron-rich as well as hole-rich regions on the graphene. Furthermore, the adsorbed graphene sheet exhibits a net total charge density gain. In this case, the graphene sheet becomes n-type doped, however, no chemical bonds form at the graphene-SiO2 interface. The electronic charge transfer from a-SiO2 to the graphene sheet occurs upon the formation of a partially occupied level lying above the Dirac point. We find that this partially occupied level comes from the three-fold coordinated oxygen atoms in the a-SiO2 substrate. © 2011 American Institute of Physics.

Pereira-Filho G.H.,Federal Rural University of Rio de Janeiro | Amado-Filho G.M.,Institute Pesquisas Jardim Botanico Do Rio Of Janeiro | De Moura R.L.,University Estadual Of Santa Cruz | Bastos A.C.,University Federal Do Esprito Santo | And 7 more authors.
Journal of Coastal Research | Year: 2012

Calcium carbonate production by marine organisms is an essential process in the global budget of CO 3 2-, and coralline reefs are the most important benthic carbonate producers. Crustose coralline algae (CCA) are well recognized as the most important carbonate builders in the tropical Brazilian continental shelf, forming structural reefs and extensive rhodolith beds. However, the distribution of CCA beds, as well as their role in CO 3 2- mineralization in mesophotic communities and isolated carbonate banks, is still poorly known. To characterize the bottom features of several seamount summits in the Southwestern Atlantic (SWA), side-scan sonar records, remotely operated vehicle imagery, and benthic samples with mixed-gas scuba diving were acquired during two recent research cruises (March 2009 and February 2011). The tops of several seamounts within this region are relatively shallow (∼60 m), flat, and dominated by rhodolith beds (Vitria, Almirante Saldanha, Davis, and Jaseur seamounts, as well as the Trindade Island shelf). On the basis of abundance, dimensions, vitality, and growth rates of CCA nodules, a mean CaCO3 production was estimated, ranging from 0.4 to 1.8 kg m -2 y -1, with a total production reaching 1.5 × 10 -3 Gt y -1. Our results indicate that these SWA seamount summits provide extensive areas of shallow reef area and represent 0.3% of the worlds carbonate banks. The importance of this habitat has been highly neglected, and immediate management needs must be fulfilled in the short term to ensure long-term persistence of the ecosystem services provided by these offshore carbonate realms. © 2012, the Coastal Education & Research Foundation (CERF).

Benevides A.B.,University Federal Do Esprito Santo | Bastos T.F.,University Federal Do Esprito Santo | Sarcinelli Filho M.,University Federal Do Esprito Santo
Proceedings - IEEE International Symposium on Circuits and Systems | Year: 2011

This paper presents the classification of three mental tasks, using the electroencephalographic signal and simulating a real-time process, that is, the pseudo-online technique. Linear Discriminant Analysis is used to recognize the mental tasks, and the feature extraction uses the Power Spectral Density. The choice of EEG channel and frequency uses the Kullback-Leibler symmetric divergence and a reclassification model is proposed to stabilize the classifier. Finally, it is expected that the proposed method can be implemented in a Brain-Computer Interface associated with a robotic wheelchair. © 2011 IEEE.

Komati K.S.,University Federal do Esprito Santo | Salles O.T.E.,University Federal do Esprito Santo | Sarcinelli-Filho M.,University Federal do Esprito Santo
Computing in Science and Engineering | Year: 2011

This fully automated process uses edge map information to eliminate false boundaries in an image's region map, and region map information to remove noise in its edge map. It then integrates the two maps into a single, final result. Experiments on a large dataset of natural color images show that this approach matches human perception better than individual methods in terms of both quantity and quality. © 2011 IEEE.

Lim J.,Korea National Arboretum | Lee J.,Yeungnam University | Koh S.,Korea forest Research Institute | Lee B.,Korea National Arboretum | And 2 more authors.
Zootaxa | Year: 2011

Nineteen Epyris species are recorded from Korea. Ten new species: E. aequalis Lim et S. Lee, sp. nov., E. breviclypeatus Lim et S. Lee, sp. nov., E. dulicus Lim et S. Lee, sp. nov., E. finitus Lim et S. Lee, sp. nov., E. jeonbukensis Lim et S. Lee, sp. nov., E. limatulus Lim et S. Lee, sp. nov., E. longiantennatus Lim et S. Lee, sp. nov., E. mureungensis Lim et S. Lee, sp. nov., E. yetus Lim et S. Lee, sp. nov., and E. sudosanensis Lim et S. Lee, sp. nov. are described from Korea. Hitherto unknown females are described for E. fuscipes (Kieffer 1906) and E. yamatonis Terayama 1999. New synonymy is proposed for E. sauteri (Enderlein 1920) = E. formosus Terayama 2006, syn. nov. New combination is proposed for E. fuscipes (Kieffer 1906), comb. nov. (from Rhabdepyris). Seven species: E. asura Terayama 2006, E. darani Terayama 2006, E. fuscipes (Kieffer 1906), E. idaten Terayama 2006, E. niwoh Terayama 2006, E. sauteri (Enderlein 1920), and E. yamatonis Terayama 1999 are recorded for the first time from Korea. Descriptions, illustrations of diagnostic characteristics for each species are presented with a key to the Korean Epyris species. © 2011.

Nunes E.T.,University Federal Do Esprito Santo | Furquim K.C.S.,Claro | Bechara G.H.,São Paulo State University | Camargo-Mathias M.I.,Claro
Ultrastructural Pathology | Year: 2010

The ultrastructure of the salivary glands of Rhipicephalus (Boophilus) microplus females is described during feeding. In beginning of feeding, individuals show acini I with many mitochondria and wide basal labyrinth in peripheral cells; glycoprotein granules only in b and c3 cells (acini II); and epithelial interstitial cells with developed basal labyrinth between f cells (acini III). Semi-engorged females show cells in degeneration, with autophagic vacuoles, lysosomes, myelin figures, and irregular, condensed, and/or fragmented nuclei, in addition to apoptotic bodies. R. B. microplus points to apoptosis in these organs before the detachment from the host, in contrast to others tick species. © 2010 Informa Healthcare USA, Inc.

De Campos R.S.,University Federal Do Esprito Santo | Philipp R.P.,Federal University of Rio Grande do Sul | Massonne H.-J.,University of Stuttgart | Chemale F.,University Of Braslia Unb | Theye T.,University of Stuttgart
International Geology Review | Year: 2012

The Brusque Metamorphic Complex (BMC) is one of the main units of the Tijucas Terrain within the Dom Feliciano Belt, located in the state of Santa Catarina in southern Brazil. In the Itapema region, the BMC is composed chiefly of metasediments, including subordinate metabasalts, meta-ultramafic rocks, and clinoamphibole schists. The metavolcanic rocks form 4m-thick lenses interlayered with metapelites and calc-silicate schists. Based on the observed textures and the associated structural, bulk-rock geochemical, and mineral chemical data, these metamafites and ultramafites were ancient lava flows of tholeiitic basalts and ultramafic cumulates. The mineral parageneses of the metabasalts are albite+actinolite+chlorite+epidote+titanite+magnetite and oligoclase+hornblende+epidote+titanite+magnetite, indicating progressive transformations produced under greenschist to amphibolite facies conditions. Volcanogenic metasediments show the same geochemical patterns as the metabasalts, whereas the metamorphosed ultramafic rocks consist of cumulates generated by crystal fractionation and flow segregation. The studied rocks show similar rare-earth element (REE) patterns, characterized by clearly higher normalized contents of light REEs compared with heavy REEs, without Eu anomalies in the metabasalts and positive Eu anomalies in meta-ultramafic rocks and volcanogenic metasediments. In accordance with the trace element contents that indicate a within-plate nature, the corresponding mafic melts apparently formed in the mantle by partial fusion and were subsequently enriched with crustal components during ascent into the sialic crust. The analysed 143Nd/ 144Nd and 87Sr/ 86Sr ratios lie between 0.5123 and 0.5126 and 0.7067 and 0.7086, respectively, and are thus typical of tholeiitic basalts of the continental plateau type. Initial Nd(936) values and derived model ages (T DM) between 1028 and 1762 million years support a mantle source or sources, with extraction and emplacement in the Neoproterozoic. Field relations and geochemical data (including isotopic data) indicate the generation of the studied mafic and ultramafic rocks in a continental rift. In the regional geologic context, the formation of the BMC volcanic and metasedimentary units marks a period of fragmentation of the Palaeoproterozoic continental crust. This extensional event is preserved regionally in gneisses from the Santa Catarina Granulitic Complex and the Cambori Complex. © 2012 Copyright Taylor and Francis Group, LLC.

Loading University Federal do Esprito Santo collaborators
Loading University Federal do Esprito Santo collaborators