Listar Ciencias Exactas y Naturales por título
Mostrando ítems 1906-1925 de 5964
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Explorando recursos simples de informática e audiovisuais : uma experiência no ensino de fluidos
(2004) [Artículo de periódico]Relata-se a utilização de trechos de filmes produzidos pela indústria cinematográfica como elemento motivador de alunos do Ensino Médio, no estudo de um tema específico de Física. O tema Fluidos foi abordado com a utilização ... -
Explorando uma colmeia : uma proposta de modelagem com o GeoGebra 3D
(2020) [Artículo de periódico]O objetivo deste artigo é refletir sobre possibilidades de trabalho com um modelo matemático dinâmico em sala de aula e potencialidades do software GeoGebra nestes possíveis cenários. Para isso, consideramos um modelo ... -
Exploration of jet substructure using iterative declustering in pp and Pb–Pb collisions at LHC energies
(2020) [Artículo de periódico]The ALICE collaboration at the CERN LHC reports novel measurements of jet substructure in pp collisions at √s = 7 TeV and central Pb–Pb collisions at √sNN = 2.76 TeV. Jet substructure of track-based jets is explored via ... -
Exploratory behavior, trap models, and glass transitions
(2004) [Artículo de periódico]A random walk is performed on a disordered landscape composed of N sites randomly and uniformly distributed inside a d-dimensional hypercube. The walker hops from one site to another with probability proportional to ... -
Exploring FSR open cluster candidates within ιΔι = 20º of the Galactic anticentre
(2008) [Artículo de periódico]Context. We investigate the nature of a sample of star cluster candidates detected as stellar overdensities towards the Galactic anticentre. Aims. Taken from the catalogue of Froebrich, Scholz, and Raftery (FSR), the sample ... -
Exploring the AGN-merger connection in Arp 245 : I: nuclear star formation and gas outflow in NGC 2992
(2021) [Artículo de periódico]Galaxy mergers are central to our understanding of galaxy formation, especially within the context of hierarchical models. Besides having a large impact on the star formation history, mergers are also able to influence gas ... -
Exploring the Barkas effect with keV-electron scattering
(2013) [Artículo de periódico]The energy loss of fast ions at close collision is mainly due to electron-ion collisions. The electrons are approximately stationary and they collidewith a fast-moving ion. Herewe study the same collision experimentally, ... -
Exploring the brown dwarf desert : new substellar companions from the SDSS-III MARVELS survey
(2017) [Artículo de periódico]Planet searches using the radial velocity technique show a paucity of companions to solar-type stars within ∼5 au in the mass range of ∼10–80 MJup. This deficit, known as the brown dwarf desert, currently has no conclusive ... -
Exploring the NΛ–NΣ coupled system with high precision correlation techniques at the LHC
(2022) [Artículo de periódico]The interaction of Λ and Σ hyperons (Y) with nucleons (N) is strongly influenced by the coupled-channel dynamics. Due to the small mass difference of the NΛ and NΣ systems, the sizable coupling strength of the NΣ ↔ NΛ ... -
Exponential estimates for "not very large deviations" and wave front propagation for class of reaction-diffusion equations
(1997) [Artículo de periódico]A Large Deviation Principle for a class of ranclom processes depending on a small parameter ε > O is established. This class of processes arises from a random perturbation of a dynamical system. Then, exponential estimates ... -
Extended gas in Seyfert 2 galaxies : implications for the nuclear source
(2003) [Artículo de periódico]We use long-slit spectroscopic optical data to derive the properties of the extended emitting gas and the nuclear luminosity of a sample of 18 Seyfert 2 galaxies. From the emissionline luminosities and ratios we derive the ... -
Extended gas in Seyfert galaxies : near-infrared observations of 15 active nuclei
(2000) [Artículo de periódico]Results from an analysis of low-resolution …(R ~ 250)† near-infrared long-slit spectra covering simultaneously the I, J, H and K bands, for a sample of 15 Seyfert galaxies and the NGC5253 starburst nucleus, are presented. ... -
Extended gas in Seyfert galaxies: near-infrared observations of NGC 2110 and Circinus
(1999) [Artículo de periódico]We present results of near-IR long-slit spectroscopy in the J and K bands of the Seyfert 2 galaxies NGC2110 and Circinus. Our goal is to investigate the gaseous distribution, excitation, reddening and kinematics, looking ... -
Extensão do método de análise de robustez para múltiplos outliers
(2016) [Artículo de periódico]Na análise de robustez, a "robustez" de uma rede geodésica é compreendida como a capacidade desta rede geodésica em "resistir" a deformações causadas por erros "não detectados" nas observações. A análise de robustez foi ... -
Extinction within 10 of the Galactic centre using 2MASS
(2003) [Artículo de periódico]We extract J and Ks magnitudes from the 2MASS Point Source Catalog for approximately 6×106 stars with 8 < - Ks < - 13 in order to build an AK extinction map within 10◦ of the Galactic centre. The extinction was determined ... -
Extração de Al(III), Cr(III) e Fe(III) de meio etanólico usando o xerogel anilinapropilsílica
(2004) [Artículo de periódico]In this study, the preparation of the xerogel anilinepropylsilica is reported. The ability of the xerogel for extracting Al(III), Cr(III) and Fe(III) from ethanol was investigated at 25 ºC. The xerogel adsorption capacities ... -
Extração semi-automática de cruzamentos de vias em áreas urbanas usando imagem de intensidade do pulso laser
(2011) [Artículo de periódico]O mapeamento de vias e malhas viárias é de fundamental importância para o desenvolvimento econômico de qualquer país, uma vez que representam os meios para o transporte convencional de bens e pessoas. Neste traballio é ... -
Extracting parameters from colour–magnitude diagrams
(2015) [Artículo de periódico]We present a simple approach for obtaining robust values of astrophysical parameters from the observed colour–magnitude diagrams (CMDs) of star clusters. The basic inputs are the Hess diagram built with the photometric ... -
Extraction kinetics and molecular size fractionation of humic substances from two brazilian soils
(1999) [Artículo de periódico]No presente trabalho foi estudada sistematicamente a extração de substâncias húmicas (SH) de um Oxisol e de um Mollisol do Sul do Brazil, empregando-se soluções de NaOH 0.1 e 0.5 mol L-1 e de Na4P2O7 0.15 mol L-1 a pH 7. ... -
Extreme and superextreme events in a loss-modulated CO2 laser : nonlinear resonance route and precursors
(2017) [Artículo de periódico]We investigate the occurrence of extreme and rare events, i.e., giant and rare light pulses, in a periodically modulated CO2 laser model. Due to nonlinear resonant processes, we show a scenario of interaction between chaotic ...
