Navegação Ciências Exatas e da Terra por Título

Resultados 3778-3797 de 5955

    • Ostracodes (crustacea) from Cananéia-Iguape estuarine/lagoon system and geographical distribution of the mixohaline assemblages in southern and southeastern Brazil 

      Coimbra, João Carlos; Carreño, Ana Luisa; Geraque, Eduardo Augusto; Eichler, Beatriz Beck (2007) [Artigo de periódico]
      As assembléias de ostracodes do sistema estuarino-lagunar de Cananéia-Iguape são pela primeira vez aqui discutidas em detalhe. Foram coletadas amostras em trinta e quatro pontos, eqüidistantes aproximadamente 1 km, incluindo ...

    • Otimização do processo de transesterificação em duas etapas para produção de biodiesel através do planejamento experimental Doehlert 

      Ruschel, Carla Felippi Chiella; Ferrão, Marco Flôres; Santos, Francisco Paulo dos; Samios, Dimitrios (2016) [Artigo de periódico]
      In this work, Doehlert experimental design was used to optimize the Transesterification Double Step Process (TDSP) method of methyl soybean oil biodiesel production which starts with a basic catalysis followed by an acidic ...

    • Outdiffusion of Be during rapid thermal annealing of high dose be implanted gaas 

      Souza, Joel Pereira de; Sadana, Devendra K.; Schad, R.G.; Norcott, M.H.; Cardone, Franck; Baratte, H. (1990) [Artigo de periódico]
      The outdiffusion of Be implanted into GaAs has been found to be identical after capless or capped (Si3N4 or Si02 ) rapid thermal annealing (RTA) at 900-1000 ºC and to depend on the Be dose and its proximity to the surface. ...

    • Outflowing gas in a compact ionization cone in the Seyfert 2 galaxy ESO 153-G20 

      Soto-Pinto, Pamela; Nagar, Neil M.; Finlez, Carolina; Ramakrishnan, Venkatessh; Munõz-Vergara, Dania; Slater, Roy; Humire, Pedro K.; Storchi-Bergmann, Thaisa; Lena, Davide; Kraemer, S. B.; Fischer, Travis C.; Schmitt, Henrique Roberto; Riffel, Rogemar André; Müller, Allan Schnorr; Robinson, Andrew; Crenshaw, Daniel Michael; Elvis, Martin (2019) [Artigo de periódico]
      We present two-dimensional ionized gas and stellar kinematics in the inner 1.4 × 1.9 kpc2 of the Seyfert 2 galaxy ESO 153-G20 obtained with the Gemini-South/Gemini multi-object spectrograph integral field unit (GMOS-IFU) ...

    • Outflows, inflows, and young stars in the inner 200 pc of the Seyfert galaxy NGC 2110 

      Diniz, Marlon Rodrigo; Riffel, Rogemar André; Storchi-Bergmann, Thaisa; Riffel, Rogério (2019) [Artigo de periódico]
      We present a 2D mapping of stellar population age components, emission-line fluxes, gas excitation, and kinematics within the inner ∼200 pc of the Seyfert 2 galaxy NGC 2110. We used the Gemini North Integral Field Spectrograph ...

    • Outflows in the inner kiloparsec of NGC1566 as revealed by molecular (ALMA) and ionized gas (Gemini-GMOS/IFU) kinematics 

      Slater, Roy; Nagar, Neil M.; Müller, Allan Schnorr; Storchi-Bergmann, Thaisa; Finlez, Carolina; Lena, Davide; Ramakrishnan, Venkatessh; Mundell, Carole G.; Riffel, Rogemar André; Peterson, Bradley M.; Robinson, Andrew; Orellana, Gustavo (2019) [Artigo de periódico]
      Context. Tracing nuclear inflows and outflows in active galactic nuclei (AGNs), determining the mass of gas involved in them, and their impact on the host galaxy and nuclear black hole requires 3D imaging studies of both ...

    • Outflows in the narrow-line region of bright Seyfert galaxies : I. GMOS-IFU data 

      Santos, Izabel Cristina Freitas dos; Riffel, Rogemar André; Storchi-Bergmann, Thaisa; Elvis, Martin; Robinson, Andrew; Crenshaw, Daniel Michael; Nagar, Neil M.; Lena, Davide; Schmitt, Henrique Roberto; Kraemer, S. B. (2018) [Artigo de periódico]
      We present two-dimensional maps of emission-line fluxes and kinematics, as well as of the stellar kinematics of the central few kpc of five bright nearby Seyfert galaxies –Mrk 6, Mrk 79, Mrk 348, Mrk 607, and Mrk 1058 – ...

    • Outliers : multicolour photometry guiding the search for evolved binary systems in the globular cluster 47Tucanae 

      Campos, Fabíola; Pelisoli, Ingrid Domingos; Kamann, Sebastian; Husser, Tim Oliver; Dreizler, Stefan; Bellini, Andrea; Robinson, E.L.; Nardiello, Domenico; Piotto, Giampaolo; Kepler, Souza Oliveira; Istrate, Alina G.; Winget, Donald Earl; Montgomery, Michael Houston; Dotter, Aaron Loveren (2018) [Artigo de periódico]
      We use Hubble Space Telescope multicolour photometry of the globular cluster 47 Tucanae to uncover a population of 24 objects with no previous classification that are outliers from the single-star model tracks in the ...

    • Out-of-equilibrium dynamics of the Hopfield model in its spin-glass phase 

      Montemurro, Marcelo A.; Tamarit, Francisco A.; Stariolo, Daniel Adrian; Cannas, Sergio A. (2000) [Artigo de periódico]
      In this paper, we study numerically the out-of-equilibrium dynamics of the Hopfield model for associative memory inside its spin-glass phase. Aside from its interest as a neural network model, it can also be considered as ...

    • Overpressurized bubbles versus voids formed in helium implanted annealed silicon 

      Fichtner, Paulo Fernando Papaleo; Kaschny, Jorge Ricardo de Araujo; Yankov, Rossen A.; Mucklich, A.; Kreissig, Ulrich; Skorupa, Wolfgang (1997) [Artigo de periódico]
      The formation of helium induced cavities in silicon is studied as a function of implant energy (10 and 40 keV) and dose (131015, 131016, and 531016 cm22). Specimens are analyzed after annealing (800 °C, 10 min) by transmission ...

    • Óxidos de ferro em cambissolos brunos no Rio Grande do Sul e sul de Minas Gerais 

      Kampf, Nestor; Dick, Deborah Pinheiro (1984) [Artigo de periódico]
      A mineralogia dos óxidos de ferro em horizontes B incipientes em ferropans e crostas de ferro de Cambis-solos Brunos do Rio Grande do Sul e de Minas Gerais, foi analisada por difratometria de raios X. A goethita é o óxido ...

    • Óxidos de ferro em latossolos tropicais e subtropicais brasileiros em plantio direto 

      Silva Neto, Luis de França da; Inda Junior, Alberto Vasconcellos; Bayer, Cimelio; Dick, Deborah Pinheiro; Tonin, Alano Thiago (2008) [Artigo de periódico]
      O sistema plantio direto (SPD) altera a taxa dos processos que ocorrem no solo, porém pouco se conhece sobre sua influência na mineralogia de solos tropicais e subtropicais. Este estudo teve por objetivo avaliar o efeito ...

    • Oxygen abundances in the narrow line regions of Seyfert galaxies and the metallicity–luminosity relation 

      Armah, Mark; Riffel, Rogério; Dors Júnior, Oli Luiz; Oh, Kyuseok; Koss, Michael; Ricci, Claudio; Trakhtenbrot, Benny; Valerdi, Mabel; Riffel, Rogemar André; Krabbe, Angela Cristina (2023) [Artigo de periódico]
      We present oxygen abundances relative to hydrogen (O/H) in the narrow line regions (NLRs) gas phases of Seyferts 1 (Sy 1s) and Seyferts 2 (Sy 2s) active galactic nuclei (AGNs). We used fluxes of the optical narrow emission ...

    • Oxygen reaction-diffusion in metalorganic chemical vapor deposition HfO/sub 2/ films annealed in O/sub 2/ 

      Bastos, Karen Paz; Morais, Jonder; Miotti, Leonardo; Pezzi, Rafael Peretti; Soares, Gabriel Vieira; Baumvol, Israel Jacob Rabin; Hegde, R.I.; Tseng, Hsing-Huang; Tobin, Phil J. (2002) [Artigo de periódico]
      Composition, atomic transport, and chemical reaction were investigated following annealing in O2 of ultrathin HfO2 films deposited on Si substrates thermally nitrided in NO. The as-prepared thin film composition was ...

    • Oxygen species in HfO/sub 2/ films : an in situ x-ray photoelectron spectroscopy study 

      Driemeier, Carlos Eduardo; Wallace, Robert M.; Baumvol, Israel Jacob Rabin (2007) [Artigo de periódico]
      The chemical bonding of O atoms in HfO2 films on Si was investigated by in situ x-ray photoelectron spectroscopy in the O 1s spectral region. In addition to trivial O forming only O-Hf bonds, O 1s signals corresponding to ...

    • Oxygen transport and GeO2 stability during thermal oxidation of Ge 

      Silva, Samoel Renan Mello da; Rolim, Guilherme Koszeniewski; Soares, Gabriel Vieira; Baumvol, Israel Jacob Rabin; Krug, Cristiano; Miotti, Leonardo; Freire Junior, Fernando Lazaro; Costa, Marcelo Eduardo Huguenin Maia da; Radtke, Claudio (2012) [Artigo de periódico]
      Oxygen transport during thermal oxidation of Ge and desorption of the formed Ge oxide are investigated. Higher oxidation temperatures and lower oxygen pressures promote GeO desorption. An appreciable fraction of oxidized ...

    • Oxygen transport and incorporation mechanisms in the dry thermal oxidation of 6H-SiC 

      Radtke, Claudio; Baumvol, Israel Jacob Rabin; Ferrera, Bauer Costa; Stedile, Fernanda Chiarello (2004) [Artigo de periódico]
      Thermal oxidation of 6H-SiC was investigated by means of isotopic tracing and narrow nuclear resonant reaction profiling techniques. The mechanisms of oxygen transport and incorporation were accessed by sequential oxidations ...

    • Oxygen transport and reaction mechanisms in rhenium gate contacts on hafnium oxide films on Si 

      Pezzi, Rafael Peretti; Copel, Matthew; Gordon, Michael; Cartier, Eduard; Baumvol, Israel Jacob Rabin (2006) [Artigo de periódico]
      Oxygen transport and incorporation were investigated following postdeposition annealing of metal-oxide-semiconductor structures having ultrathin rhenium films as metal electrode and HfO2 films as dielectric on Si 001 . ...

    • OzDES multifibre spectroscopy for the Dark Energy Survey : 3-yr results and first data release 

      Childress, Michael; Ostrovski, F.; DES Collaboration (2017) [Artigo de periódico]
      We present results for the first three years of OzDES, a six year programme to obtain redshifts for objects in the Dark Energy Survey (DES) supernova fields using the 2dF fibre positioner and AAOmega spectrograph on the ...

    • OzDES multi-object fibre spectroscopy for the Dark Energy Survey : results and second data release 

      Lidman, Chris; Santiago, Basilio Xavier; DES Collaboration (2020) [Artigo de periódico]
      We present a description of the Australian Dark Energy Survey (OzDES) and summarize the results from its 6 years of operations. Using the 2dF fibre positioner and AAOmega spectrograph on the 3.9-m Anglo-Australian Telescope, ...