Mostrando recursos 1 - 20 de 28

  1. Método do enxame de partículas para otimização de modelos de regressão multivariada empregados na determinação de biodiesel em blendas biodiesel/óleo vegetal/diesel

    Rizzi, Marlize; Furtado, João Carlos; Costa, Adilson Ben da; Gerbase, Annelise Engel; Ferrão, Marco Flôres
    Foram comparados diferentes modelos de regressão multivariada por mínimos quadrados parciais para a quantificação de biodiesel nas blendas binárias e ternárias biodiesel/óleo vegetal/diesel empregando espectrofotometria no infravermelho médio com reflexão total atenuada (FTIR/ATR). Um total de oitenta blendas binárias ou ternárias foram empregadas para a construção e validação dos modelos. O método do enxame de partículas (PSO) foi implementado para a otimização das regiões espectrais juntamente com a regressão por mínimos quadrados parciais por intervalo (iPLS). Dentre os modelos por PLS empregando: toda a faixa espectral 4000-650 cm-1, as regiões espectrais sugeridas pela norma ASTM NBR 15568 (1750-1735 cm-1 e...

  2. Spin-glass phase transition and behavior of nonlinear susceptibility in the Sherrington-Kirkpatrick model with random fields

    Morais, C. V.; Zimmer, Fábio Mallmann; Lazo, Matheus Jatkoske; Magalhaes, Sergio Garcia; Nobre, Fernando D.
    The behavior of the nonlinear susceptibility χ3 and its relation to the spin-glass transition temperature Tf in the presence of random fields are investigated. To accomplish this task, the Sherrington-Kirkpatrick model is studied through the replica formalism, within a one-step replica-symmetry-breaking procedure. In addition, the dependence of the Almeida-Thouless eigenvalue λAT (replicon) on the random fields is analyzed. Particularly, in the absence of random fields, the temperature Tf can be traced by a divergence in the spin-glass susceptibility χSG, which presents a term inversely proportional to the replicon λAT. As a result of a relation between χSG and χ3, the...

  3. Fate of topological states in incommensurate generalized Aubry-André models

    Cestari, Jardel Caminha Carvalho; Foerster, Angela; Gusmao, Miguel Angelo Cavalheiro
    We study one-dimensional optical lattices described by generalized Aubry-André models that include both commensurate and incommensurate modulations of the hopping amplitude. This brings together two interesting features of this class of systems: Anderson localization and the existence of topological edge states. We follow changes of the single-particle energy spectrum induced by variations of the system parameters, with focus on the survival of topological states in the localized regime.

  4. A SINFONI view of the nuclear activity and circumnuclear star formation in NGC 4303

    Riffel, Rogemar André; Colina, Luis; Storchi-Bergmann, Thaisa; Piqueras López, Javier; Arribas, Santiago; Riffel, Rogério; Pastoriza, Miriani Griselda; Sales, Dinalva Aires de; Dametto, Natacha Zanon; Labiano, Alvaro; Davies, Richard I.
    We present new maps of emission-line flux distributions and kinematics in both ionized (traced by HI and [Fe II] lines) and molecular (H2) gas of the inner 0.7 × 0.7 kpc2 of the galaxy NGC 4303, with a spatial resolution 40–80 pc and velocity resolution 90–150 km s−1 obtained from near-IR integral field spectroscopy using the Very Large Telescope instrument SINFONI. The most prominent feature is a 200–250 pc ring of circumnuclear star-forming regions. The emission from ionized and molecular gas shows distinct flux distributions: while the strongest HI and [Fe II] emission comes from regions in the west side...

  5. redMaGiC : selecting luminous red galaxies from the DES Science Verification data

    Rozo, Eduardo; Rykoff, Eli; Abate, Alexandra; Bonnet, Christopher Clive; Crocce, Martin; Davis, Christopher P.; Hoyle, Ben; Leistedt, Boris; Peiris, Hiranya V.; Wechsler, Risa H.; Abbott, Timothy M. C.; Abdalla, Filipe B.; Banerji, M.; Bauer, Anne Hollister; Benoit-Lévy, Aurélien; Bernstein, Gary M.; Bertin, Emmanuel; Brooks, D.; Buckley-Geer, Elizabeth; Burke, David Lyle; Capozzi, Diego; Carnero Rosell, Aurelio; Carollo, Daniela; Carrasco Kind, Matías; Carretero Palacios, Jorge; Castander Serentill, Francisco Javier; Childress, Michael; Cunha, Carlos Eduardo; D'Andrea, Christopher B.; Davis, Tamara M.; DePoy, Darren L.; Desai, S.; Diehl, H. Thomas; Dietrich, Jörg P.; Doel, Peter; Eifler, Tim; Evrard, August E.; Fausti Neto, Angelo; Flaugher, Brenna; Fosalba Vela, Pablo; Frieman, Joshua A.; Gaztañaga, Enrique; Gerdes, David W.; Glazebrook, Karl; Gruen, Daniel; Gruendl, Robert A.; Honscheid, K.; James, David J.; Jarvis, Michael; Kim, A. G.; Kuehn, Kyler; Kuropatkin, Nikolay P.; Lahav, Ofer; Lewis, Geraint F.; Lidman, Chris; Lima, Marcos Vinicius Borges Teixeira; Maia, Marcio Antonio Geimba; March, Marisa Cristina; Martini, Paul; Melchior, Peter M.; Miller, Christopher J.; Miquel, Ramon; Mohr, Joseph J.; Nichol, Robert C.; Nord, Brian Dennis; O'Neill, C. R.; Ogando, Ricardo L.C.; Plazas Malagón, Andrés Alejandro; Romer, Anita K.; Roodman, Aaron; Sako, Masao; Sanchez-Alvaro, Eusebio; Santiago, Basilio Xavier; Schubnell, Michael; Sevilla Noarbe, Ignacio; Smith, Robert Christopher; Soares-Santos, Marcelle; Sobreira, Flávia; Suchyta, Eric; Swanson, Molly E. C.; Thaler, Jon J.; Thomas, Daniel B.; Uddin, Syed; Vikram, Vinu; Walker, Alistair; Wester, William Carl; Zhang, Yuying; Costa, Luiz N. da
    We introduce redMaGiC, an automated algorithm for selecting luminous red galaxies (LRGs). The algorithm was specifically developed to minimize photometric redshift uncertainties in photometric large-scale structure studies. redMaGiC achieves this by self-training the colour cuts necessary to produce a luminosity-thresholded LRG sample of constant comoving density. We demonstrate that redMaGiC photo-zs are very nearly as accurate as the best machine learning-based methods, yet they require minimal spectroscopic training, do not suffer from extrapolation biases, and are very nearly Gaussian. We apply our algorithm to Dark Energy Survey (DES) Science Verification (SV) data to produce a redMaGiC catalogue sampling the redshift...

  6. Alternative method to characterize continuous and discontinuous phase transitions in surface reaction models

    Fernandes, Henrique Almeida; Silva, Roberto da; Santos, Eder D.; Gomes, Paulo F.; Arashiro, Everaldo Y.
    In this paper we revisited the Ziff-Gulari-Barshad model to study its phase transitions and critical exponents through time-dependent MonteCarlo simulations.We use amethod proposed recently to locate the nonequilibrium second-order phase transitions and that has been successfully used in systems with defined Hamiltonians and with absorbing states. This method, which is based on optimization of the coefficient of determination of the order parameter, was able to characterize the continuous phase transition of the model, as well as its upper spinodal point, a pseudocritical point located near the discontinuous phase transition. The static critical exponents β, ν , and ν⊥, as well...

  7. Physical properties of star clusters in the outer LMC as observed by the DES

    Pieres, Adriano; Santiago, Basilio Xavier; Balbinot, Eduardo; Luque Canaza, Elmer Fidel; Queiroz, Anna Bárbara de Andrade; Costa, Luiz N. da; Maia, Marcio Antonio Geimba; Drlica-Wagner, Alex; Roodman, Aaron; Abbott, Timothy M. C.; Alam, Shadab; Benoit-Lévy, Aurélien; Bertin, Emmanuel; Brooks, D.; Buckley-Geer, Elizabeth; Burke, David Lyle; Carnero Rosell, Aurelio; Carrasco Kind, Matías; Carretero Palacios, Jorge; Cunha, Carlos Eduardo; Desai, S.; Diehl, H. Thomas; Eifler, Tim; Finley, David A.; Flaugher, Brenna; Fosalba Vela, Pablo; Frieman, Joshua A.; Gerdes, David W.; Gruen, Daniel; Gruendl, Robert A.; Gutierrez, Gaston R.; Honscheid, K.; James, David J.; Kuehn, Kyler; Kuropatkin, Nikolay P.; Lahav, Ofer; Li, T. S.; Marshall, Jennifer L.; Martini, Paul; Miller, Christopher J.; Miquel, Ramon; Nichol, Robert C.; Nord, Brian Dennis; Ogando, Ricardo L.C.; Plazas Malagón, Andrés Alejandro; Romer, Anita K.; Sanchez-Alvaro, Eusebio; Scarpine, Victor Emanuel; Schubnell, Michael; Sevilla Noarbe, Ignacio; Smith, Robert Christopher; Soares-Santos, Marcelle; Sobreira, Flávia; Suchyta, Eric; Swanson, Molly E. C.; Tarle, Gregory; Thaler, Jon J.; Thomas, Daniel B.; Tucker, Douglas L.; Walker, Alistair
    The Large Magellanic Cloud (LMC) harbours a rich and diverse system of star clusters, whose ages, chemical abundances and positions provide information about the LMC history of star formation. We use Science Verification imaging data from the Dark Energy Survey (DES) to increase the census of known star clusters in the outer LMC and to derive physical parameters for a large sample of such objects using a spatially and photometrically homogeneous data set. Our sample contains 255 visually identified cluster candidates, of which 109 were not listed in any previous catalogue.We quantify the crowding effect for the stellar sample produced...

  8. Effects of the quark-hadron phase transition on highly magnetized neutron stars

    Franzon, Bruno; Gomes, Rosana de Oliveira; Schramm, Stefan
    The presence of quark-hadron phase transitions in neutron stars can be related to several interesting phenomena. In particular, previous calculations have shown that fast rotating neutron stars, when subjected to a quark-hadron phase transition in their interiors, could give rise to the backbending phenomenon characterized by a spin-up era. In this work, we use an equation of state composed of two phases, containing nucleons (and leptons) and quarks. The hadronic phase is described in a relativistic mean field formalism that takes many-body forces into account, and the quark phase is described by the MIT bag model with a vector interaction....

  9. A dark energy camera search for missing supergiants in the LMC after the advanced LIGO gravitational-wave event GW150914

    Annis, James T.; Soares-Santos, Marcelle; Berger, Edo; Brout, Dillon J.; Chen, Hsinyu; Chornock, Ryan; Cowperthwaite, Philip S.; Diehl, H. Thomas; Doctor, Z.; Drlica-Wagner, Alex; Drout, Maria R.; Farr, Benjamin F.; Finley, David A.; Flaugher, Brenna; Foley, Ryan Joseph; Frieman, Joshua A.; Gruendl, Robert A.; Herner, Kenneth R.; Holz, Daniel E.; Kessler, Richard S.; Lin, H.; Marriner, John P.; Neilsen, Eric H.; Rest, Armin; Sako, Masao; Smith, Matthew Wilson L; Smith, Nathan D.; Sobreira, Flávia; Walker, Alistair; Yanny, Brian; Abbott, Timothy M. C.; Abdalla, Filipe B.; Allam, Sahar S.; Benoit-Lévy, Aurélien; Bernstein, Gary M.; Bertin, Emmanuel; Buckley-Geer, Elizabeth; Burke, David Lyle; Capozzi, Diego; Carnero Rosell, Aurelio; Carrasco Kind, Matías; Carretero Palacios, Jorge; Castander Serentill, Francisco Javier; Cenko, Stephen Bradley; Crocce, Martin; Cunha, Carlos Eduardo; D'Andrea, Christopher B.; Costa, Luiz N. da; Desai, S.; Dietrich, Jörg P.; Eifler, Tim; Evrard, August E.; Fernández, Eva María; Fischer, John A.; Fong, Wenfai; Fosalba Vela, Pablo; Fox, Derek B.; Fryer, Chris L.; García-Bellido, Juan; Gaztañaga, Enrique; Gerdes, David W.; Goldstein, Daniel Abraham; Gruen, Daniel; Gutierrez, Gaston R.; Honscheid, K.; James, David J.; Karliner, Inga; Kasen, Daniel N.; Kent, Stephen M.; Kuehn, Kyler; Kuropatkin, Nikolay P.; Lahav, Ofer; Li, T. S.; Lima, Marcos Vinicius Borges Teixeira; Maia, Marcio Antonio Geimba; Martini, Paul; Metzger, Brian D.; Miller, Christopher J.; Miquel, Ramon; Mohr, Joseph J.; Nichol, Robert C.; Nord, Brian Dennis; Ogando, Ricardo L.C.; Peoples, John; Petravick, Donald L.; Plazas Malagón, Andrés Alejandro; Quataert, Eliot J.; Romer, Anita K.; Roodman, Aaron; Rykoff, Eli; Sanchez-Alvaro, Eusebio; Santiago, Basilio Xavier; Scarpine, Victor Emanuel; Schindler, Rafe H.; Schubnell, Michael; Sevilla Noarbe, Ignacio; Sheldon, Erin; Smith, Robert Christopher; Stebbins, Albert J.; Swanson, Molly E. C.; Tarle, Gregory; Thaler, Jon J.; Thomas, Rollin C.; Tucker, Douglas L.; Vikram, Vinu; Wechsler, Risa H.; Weller, Jochen; Wester, William Carl; DES Collaboration
    The collapse of a stellar core is expected to produce gravitational waves (GWs), neutrinos, and in most cases a luminous supernova. Sometimes, however, the optical event could be significantly less luminous than a supernova and a direct collapse to a black hole, where the star just disappears, is possible. The GW event GW150914 was detected by the LIGO Virgo Collaboration via a burst analysis that gave localization contours enclosing the Large Magellanic Cloud (LMC). Shortly thereafter, we used DECam to observe 102 deg2 of the localization area, including 38 deg2 on the LMC for a missing supergiant search. We construct...

  10. Os mestrados profissionais em ensino das ciências da natureza no Brasil

    Ostermann, Fernanda; Santos, Flavia Rezende Valle dos
    Resumo não disponível

  11. O protagonismo controverso dos mestrados profissionais em ensino de ciências

    Santos, Flavia Rezende Valle dos; Ostermann, Fernanda
    O aumento da implantação de cursos de mestrado profissional em ensino vem sendo indicador dos novos contornos das políticas de formação impostos pela CAPES como agência reguladora da formação de professores. Dada a atual predominância desses cursos na área de ensino, empreendemos uma reflexão sobre o papel dos mestrados profissionais na busca da qualidade da educação brasileira e, em particular, da educação em ciências. Para tal, o caminho metodológico apoiou-se em um quadro crítico da situação do Ensino Médio no país e em um referencial marxista sobre a formação docente. Tanto pelos aspectos curriculares, que variam muito de acordo com...

  12. The Phoenix stream : a cold stream in the southern hemisphere

    Balbinot, Eduardo; Yanny, Brian; Li, T. S.; Santiago, Basilio Xavier; Marshall, Jennifer L.; Finley, David A.; Pieres, Adriano; Abbott, Timothy M. C.; Abdalla, Filipe B.; Allam, Sahar S.; Benoit-Lévy, Aurélien; Bernstein, Gary M.; Bertin, Emmanuel; Brooks, D.; Burke, David Lyle; Carnero Rosell, Aurelio; Carrasco Kind, Matías; Carretero Palacios, Jorge; Cunha, Carlos Eduardo; Costa, Luiz N. da; DePoy, Darren L.; Desai, S.; Diehl, H. Thomas; Doel, Peter; Estrada, Juan; Flaugher, Brenna; Frieman, Joshua A.; Gerdes, David W.; Gruen, Daniel; Gruendl, Robert A.; Honscheid, K.; James, David J.; Kuehn, Kyler; Kuropatkin, Nikolay P.; Lahav, Ofer; March, Marisa Cristina; Martini, Paul; Miquel, Ramon; Nichol, Robert C.; Ogando, Ricardo L.C.; Romer, Anita K.; Sanchez-Alvaro, Eusebio; Schubnell, Michael; Sevilla Noarbe, Ignacio; Smith, Robert Christopher; Soares-Santos, Marcelle; Sobreira, Flávia; Suchyta, Eric; Tarle, Gregory; Thomas, D.; Tucker, Douglas L.; Walker, Alistair; DES Collaboration
    We report the discovery of a stellar stream in the Dark Energy Survey Year 1 (Y1A1) data. The discovery was made through simple color–magnitude filters and visual inspection of the Y1A1 data. We refer to this new object as the Phoenix stream, after its resident constellation. After subtraction of the background stellar population we detect a clear signal of a simple stellar population. By fitting the ridge line of the stream in color–magnitude space, we find that a stellar population with age τ=11.5±0.5 Gyr and [Fe/H]<−1.6, located 17.5±0.9 kpc from the Sun, gives an adequate description of the stream stellar...

  13. Observation of two new L4 Neptune Trojans in the Dark Energy Survey supernova fields

    Gerdes, David W.; Jennings, R. J.; Bernstein, Gary M.; Sako, Masao; Adams, Fred; Goldstein, Daniel Abraham; Kessler, Richard S.; Hamilton, S.; Abbott, Timothy M. C.; Abdalla, Filipe B.; Allam, Sahar S.; Benoit-Lévy, Aurélien; Bertin, Emmanuel; Brooks, D.; Buckley-Geer, Elizabeth; Burke, David Lyle; Capozzi, Diego; Carnero Rosell, Aurelio; Carrasco Kind, Matías; Carretero Palacios, Jorge; Cunha, Carlos Eduardo; D'Andrea, Christopher B.; Costa, Luiz N. da; DePoy, Darren L.; Desai, S.; Dietrich, Jörg P.; Doel, Peter; Eifler, Tim; Fausti Neto, Angelo; Flaugher, Brenna; Frieman, Joshua A.; Gaztañaga, Enrique; Gruen, Daniel; Gruendl, Robert A.; Gutierrez, Gaston R.; Honscheid, K.; James, David J.; Kuehn, Kyler; Kuropatkin, Nikolay P.; Lahav, Ofer; Li, T. S.; Maia, Marcio Antonio Geimba; March, Marisa Cristina; Martini, Paul; Miller, Christopher J.; Miquel, Ramon; Nichol, Robert C.; Nord, Brian Dennis; Ogando, Ricardo L.C.; Plazas Malagón, Andrés Alejandro; Romer, Anita K.; Roodman, Aaron; Sanchez-Alvaro, Eusebio; Santiago, Basilio Xavier; Schubnell, Michael; Sevilla Noarbe, Ignacio; Smith, Robert Christopher; Soares-Santos, Marcelle; Sobreira, Flávia; Suchyta, Eric; Swanson, Molly E. C.; Tarle, Gregory; Thaler, Jon J.; Walker, Alistair; Wester, William Carl; Zhang, Y.; DES Collaboration
    We report the discovery of the eighth and ninth known Trojans in stable orbits around Neptune’s leading Lagrange point, L4. The objects 2014QO441 and 2014QP441 were detected in data obtained during the 2013–14 and 2014–15 observing seasons by the Dark Energy Survey, using the Dark Energy Camera (DECam) on the 4-m Blanco telescope at Cerro Tololo Inter-American Observatory. Both are in high-inclination orbits (18°.8 and 19°.4, respectively). With an eccentricity of 0.104, 2014QO441 has the most eccentric orbit of the 11 known stable Neptune Trojans. Here we describe the search procedure and investigate the objects’ long-term dynamical stability and physical...

  14. Discovery of a stellar overdensity in Eridanus-Phoenix in the Dark Energy Survey

    Li, T. S.; Balbinot, Eduardo; Mondrik, Nicholas Payne; Marshall, Jennifer L.; Yanny, Brian; Bechtol, Keith; Drlica-Wagner, Alex; Oscar, Douglas Darcie; Santiago, Basilio Xavier; Simon, Josh D.; Vivas, Anna Katherina; Walker, Alistair; Wang, M.; Abbott, Timothy M. C.; Abdalla, Filipe B.; Benoit-Lévy, Aurélien; Bernstein, Gary M.; Bertin, Emmanuel; Brooks, D.; Burke, David Lyle; Carnero Rosell, Aurelio; Carretero Palacios, Jorge; Costa, Luiz N. da; DePoy, Darren L.; Desai, S.; Diehl, H. Thomas; Doel, Peter; Estrada, Juan; Finley, David A.; Flaugher, Brenna; Frieman, Joshua A.; Gruen, Daniel; Gruendl, Robert A.; Gutierrez, Gaston R.; Honscheid, K.; James, David J.; Kuehn, Kyler; Kuropatkin, Nikolay P.; Lahav, Ofer; Maia, Marcio Antonio Geimba; March, Marisa Cristina; Martini, Paul; Ogando, Ricardo L.C.; Plazas Malagón, Andrés Alejandro; Reil, Kevin; Romer, Anita K.; Roodman, Aaron; Sanchez-Alvaro, Eusebio; Scarpine, Victor Emanuel; Schubnell, Michael; Sevilla Noarbe, Ignacio; Smith, Robert Christopher; Soares-Santos, Marcelle; Sobreira, Flávia; Suchyta, Eric; Swanson, Molly E. C.; Tarle, Gregory; Tucker, Douglas L.; Zhang, Y.; DES Collaboration
    We report the discovery of an excess of main-sequence turnoff stars in the direction of the constellations of Eridanus and Phoenix from the first-year data of the Dark Energy Survey (DES). The Eridanus–Phoenix (EriPhe) overdensity is centered around l ~ 285 and b ~ -60 and spans at least 30° in longitude and 10° in latitude. The Poisson significance of the detection is at least 9s. The stellar population in the overdense region is similar in brightness and color to that of the nearby globular cluster NGC 1261, indicating that the heliocentric distance of EriPhe is about d ~ 16...

  15. Evaluation of Coastal Scenery in Urban Beach: Torres, Rio Grande do Sul, Brazil

    Cristiano, Samanta da Costa; Rockett, Gabriela Camboim; Portz, Luana Carla; Anfuso, Giorgio; Gruber, Nelson Luiz Sambaqui; Williams, Allan T.
    Two polyethylene-based on single-site metallocene catalyst (mLLDPE) were selected to characterize the effect of long chain branching (LCB) on blown film processability, optical and mechanical properties. 13C NMR and parallel plate rheology were used to identify LCB presence on LLDPEs. Blown films were produced from 100% LLDPEs using three different machine direction (MD) stretch ratios. When the same processing conditions for the two LLDPEs grades were used, better processability was observed for LLDPE with LCB. In relation to mechanical and physical properties, Elmendorf tear and optical properties were highly influenced by the presence of LCB. Tear resistance is affected by...

  16. Eight ultra-faint galaxy candidates discovered in year two the Dark Energy Survey

    Drlica-Wagner, Alex; Bechtol, Keith; Rykoff, Eli; Luque Canaza, Elmer Fidel; Queiroz, Anna Bárbara de Andrade; Mao, Yao-Yuan; Wechsler, Risa H.; Simon, Josh D.; Santiago, Basilio Xavier; Yanny, Brian; Balbinot, Eduardo; Dodelson, Scott; Fausti Neto, Angelo; James, David J.; Li, T. S.; Maia, Marcio Antonio Geimba; Marshall, Jennifer L.; Pieres, Adriano; Stringer, Katelyn M.; Walker, Alistair; Abbott, Timothy M. C.; Abdalla, Filipe B.; Allam, Sahar S.; Benoit-Lévy, Aurélien; Bernstein, Rebecca A.; Bernstein, Gary M.; Bertin, Emmanuel; Brooks, D.; Buckley-Geer, Elizabeth; Burke, David Lyle; Carnero Rosell, Aurelio; Carrasco Kind, Matías; Carretero Palacios, Jorge; Crocce, Martin; Costa, Luiz N. da; Desai, S.; Diehl, H. Thomas; Dietrich, Jörg P.; Doel, Peter; Eifler, Tim; Evrard, August E.; Flaugher, Brenna; Fosalba Vela, Pablo; Frieman, Joshua A.; Gaztañaga, Enrique; Gerdes, David W.; Gruen, Daniel; Gruendl, Robert A.; Gutierrez, Gaston R.; Honscheid, K.; Kuehn, Kyler; Kuropatkin, Nikolay P.; Lahav, Ofer; Miquel, Ramon; Nord, Brian Dennis; Ogando, Ricardo L.C.; Plazas Malagón, Andrés Alejandro; Reil, Kevin; Roodman, Aaron; Sako, Masao; Sanchez-Alvaro, Eusebio; Scarpine, Victor Emanuel; Schubnell, Michael; Sevilla Noarbe, Ignacio; Smith, Robert Christopher; Soares-Santos, Marcelle; Sobreira, Flávia; Suchyta, Eric; Swanson, Molly E. C.; Tarle, Gregory; Tucker, Douglas L.; Vikram, Vinu; Wester, William Carl; Zhang, Y.; Zuntz, J.; DES Collaboration
    We report the discovery of eight new ultra-faint dwarf galaxy candidates in the second year of optical imaging data from the Dark Energy Survey (DES). Six of these candidates are detected at high confidence, while two lowerconfidence candidates are identified in regions of non-uniform survey coverage. The new stellar systems are found by three independent automated search techniques and are identified as overdensities of stars, consistent with the isochrone and luminosity function of an old and metal-poor simple stellar population. The new systems are faint (MV > −4.7mag) and span a range of physical sizes (17 pc < r1/2 <...

  17. O mestrado profissional na área de ensino de ciências e matemática : alguns esclarecimentos

    Moreira, Marco Antonio; Nardi, Roberto
    Este artigo, elaborado a partir de documentos gerados e utilizados nos últimos anos pelas comissões e coordenações da Área de Ensino de Ciências e Matemática da CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior)/MEC, contém alguns esclarecimentos relativos ao Mestrado Profissional em Ensino de Ciências e Matemática. Esse tipo de mestrado é uma inovação no Brasil e constitui-se em uma iniciativa promissora para a melhoria do ensino de Ciências e Matemática no país. Poderá também estimular o desenvolvimento de propostas em outros países que apresentam similaridades com a situação educacional brasileira.

  18. Análise da transformação da Floresta Amazônica a partir do uso de geotecnologias : Google Earth engine – nas aulas de geografia do Ensino Fundamental

    Caña, Betania Bonada; Rosa, Kátia Kellem da; Costella, Roselane Zordan
    Este trabalho compreende uma discussão da aplicação de uma atividade de ensino de Geografia com o uso de geotecnologias. A prática pedagógica objetivou o estudo do desmatamento da Amazônia através do uso de geotecnologias que permitem análises das transformações espaço/temporais na floresta, utilizando as imagens de satélites e o programa Google Earth Engine. Verificou-se que o uso paralelo destes produtos representa uma ferramenta essencial para a aprendizagem ativa dos alunos, levando em consideração as experiências e os saberes dos mesmos, através do desenvolvimento de capacidades cognitivas/operativas e da construção de conceitos importantes da disciplina de Geografia. Resultando em uma aproximação...

  19. Massive open star clusters using the VVV survey : III. A young massive cluster at the far edge of the Galactic bar

    Ramírez Alegría, Sebastián; Borissova, Jura; Chené, André-Nicolas; O'Leary, E.; Amigo, Pia; Minniti, Dante; Saito, Roberto K.; Geisler, Doug; Kurtev, Radostin Georgiev; Hempel, Maren; Gromadzki, Mariusz; Clarke, J. R. A.; Negueruela Díez, Ignacio; Marco Tobarra, Amparo; Fierro, C.; Bonatto, Charles Jose; Catelan, Márcio
    Context. Young massive clusters are key to map the Milky Way’s structure, and near-infrared large area sky surveys have contributed strongly to the discovery of new obscured massive stellar clusters. Aims. We present the third article in a series of papers focused on young and massive clusters discovered in the VVV survey. This article is dedicated to the physical characterization of VVVCL086, using part of its OB-stellar population. Methods. We physically characterized the cluster using JHKS near-infrared photometry from ESO public survey VVV images, using the VVV-SkZ pipeline, and near-infrared K-band spectroscopy, following the methodology presented in the first article...

  20. Topological hypothesis on phase transitions : the simplest case

    Teixeira, Ana Carolina Ribeiro; Stariolo, Daniel Adrian
    We critically analyze the possibility of finding signatures of a phase transition by looking exclusively at static quantities of statistical systems, like, e.g., the topology of potential energy submanifolds (PES’s). This topological hypothesis has been successfully tested in a few statistical models but up to now there has been no rigorous proof of its general validity. We make a new test of it analyzing the, probably, simplest example of a nontrivial system undergoing a continuous phase transition: the completely connected version of the spherical model. Going through the topological properties of its PES it is shown that, as expected, the...

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