10,694 research outputs found
Bromeliaceae species from coastal restinga habitats, Brazilian states of Rio de Janeiro, Espírito Santo, and Bahia.
Bromeliaceae is one of the most representative plant families in restinga habitats. We analyzed the speciesrichness and composition of Bromeliaceae in 13 restinga habitats along the Brazilian coast. We found a total of 41species distributed along the restinga habitats studied. The restinga of Praia do Sul, in the state of Rio de Janeiro, hadthe highest number of species (15), whereas the restinga of Abaeté, in the state of Bahia, had the lowest (4). Our dataare suggestive that the Doce River may represent the limit of distribution for some bromeliad species, with some speciesoccurring only south of that river and others occurring only to the north of it. The differences in Bromeliaceae speciescomposition among restinga habitats probably are not only due to differences in local environmental conditions, butalso due to the geographic distribution pattern of each species and to the present degree of disturbance at each restinga
Efeito de diferentes níveis de fertilizante (NPK) sobre o crescimento e desenvolvimento de mudas enviveiradas de táxi branco (Sclerolobium paniculatum) e fava-orelha-de-negro (Enterolobium schomburgkii, Benth.).
Effect of extended surfaces on lauric acid melting process in annular cavities
The objective of the present work is to parametrically analyze the effect of extended surfaces’ proportion and positioning on the lauric acid melting process, in an annular cavity. In total 46 geometric configurations were studied, varying between 5 area ratios, 5 proportions, and 2 positions of the extended surface. Numerical simulations performed with the finite volume method were used to conduct the study. The numerical model, composed of the continuity, momentum conservation, and energy conservation equations, plus the enthalpy-porosity phase change model, was validated with experimental data from the literature. The Grid Convergence Index (GCI) was used to evaluate the computational mesh, resulting in an average index of 0.0026%. The results are presented in terms of liquid fraction vs Fourier, and Nusselt number vs. Fourier. Besides, velocity vectors, and streamlines, liquid fraction, and temperature fields, were presented, comparing different instants and geometric arrangements. For the analysis of the results, the melting time was considered as a performance indicator. The results revealed that: while there is solid PCM in the cavity's upper section, the melting rate in systems with horizontal extensions is 15% higher than systems with vertical extensions; when the extended surface thinness is increased, the overall melting time is reduced by more than 10% in vertical arrangements and less than 1.5% in horizontal arrangements; the total melting time is nearly 45% faster in systems with vertical extensions than in systems with horizontal extensions
Avaliação biométrica do crescimento de andiroba (Carapa guianensis Aubl.) e mogno-africano (Kaya ivorensis A. Chev.) frente a sazonalidade climática das áreas de várzea.
Germinação de diferentes genótipos de feijão submetidos ao estresse hídrico pela diminuição do potencial osmótico.
O presente trabalho teve como objetivo simular condições padronizadas de déficit hídrico em laboratório para a avaliação da germinação de sementes de diferentes genótipos de feijão. O experimento foi realizado no Laboratório da Universidade Estadual de Goiás - Unidade Universitária de Ipameri
GeoCLEF 2006: the CLEF 2006 Ccross-language geographic information retrieval track overview
After being a pilot track in 2005, GeoCLEF advanced to be a regular track within CLEF 2006. The
purpose of GeoCLEF is to test and evaluate cross-language geographic information retrieval (GIR): retrieval for
topics with a geographic specification. For GeoCLEF 2006, twenty-five search topics were defined by the
organizing groups for searching English, German, Portuguese and Spanish document collections. Topics were
translated into English, German, Portuguese, Spanish and Japanese. Several topics in 2006 were significantly
more geographically challenging than in 2005. Seventeen groups submitted 149 runs (up from eleven groups and
117 runs in GeoCLEF 2005). The groups used a variety of approaches, including geographic bounding boxes,
named entity extraction and external knowledge bases (geographic thesauri and ontologies and gazetteers)
Challenges to evaluation of multilingual geographic information retrieval in GeoCLEF
This is the third year of the evaluation of
geographic information retrieval (GeoCLEF)
within the Cross-Language Evaluation Forum
(CLEF). GeoCLEF 2006 presented topics and
documents in four languages (English,
German, Portuguese and Spanish). After two
years of evaluation we are beginning to
understand the challenges to both Geographic
Information Retrieval from text and of
evaluation of the results of geographic
information retrieval. This poster enumerates
some of these challenges to evaluation and
comments on the limitations encountered in the
first two evaluations
Non-dissipative anomalous currents in 2D materials: the parity magnetic effect as an analog of the chiral magnetic effect
Anomalous electric currents along a magnetic field, first predicted to emerge
during large heavy ion collision experiments, were also observed a few years
ago in condensed matter environments, exploring the fact that charge carriers
in Dirac/Weyl semi-metals exhibit a relativistic-like behavior. The mechanism
through which such currents are generated relies on an imbalance in the
chirality of systems immersed in a magnetic background, leading to the
so-called chiral magnetic effect (CME). While chiral magnetic currents have
been observed in materials in three space dimensions, in this work we propose
that an analog of the chiral magnetic effect can be constructed in two space
dimensions, corresponding to a novel type of intrinsic half-integer Quantum
Hall effect, thereby also offering a topological protection mechanism for the
current. While the 3D chiral anomaly underpins the CME, its 2D cousin is
emerging from the 2D parity anomaly, we thence call it the parity magnetic
effect (PME). It can occur in disturbed honeycomb lattices where both spin
degeneracy and time reversal symmetry are broken. These configurations harbor
two distinct gap-opening mechanisms that, when occurring simultaneously, drive
slightly different gaps in each valley, establishing an analog of the necessary
chiral imbalance. Some examples of promising material setups that fulfill the
prerequisites of our proposal are also listed.Comment: 11 pages, 5 figure
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