Wave Fronts
Mostrando 1-12 de 17 artigos, teses e dissertações.
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1. Transient wave propagation phenomena at visco-elastic half-spaces under distributed surface loadings
This article analyzes the transient wave propagation phenomena that take place at 2D viscoelastic half-spaces subjected to spatially distributed surface loadings and to distinct temporal excitations. It starts with a fairly detailed review of the existing strategies to describe transient analysis for elastic and viscoelastic continua by means of the Boundary
Lat. Am. j. solids struct.. Publicado em: 2012-08
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2. Invariantes de frentes de ondas planas / Invariants of wave fronts
Esta dissertação é dedicada ao estudo dos invariantes de frentes de ondas planas seguindo o trabalho desenvolvido por F. Aicardi em [Ai1]. Ela encontra estes invariantes fazendo uma generalização dos invariantes de curvas planas introduzidos por Arnold utilizando a teoria de Vassiliev. Neste trabalho estudamos e descrevemos os invariantes de Aicardi, as
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 30/04/2010
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3. Estudo de frentes mesosféricas na região equatorial / Study of mesospheric fronts in the equatorial region
An extensive study on mesospheric fronts was carried out by means of mesospheric airglow image observation at at São João do Cariri, PB (7,4oS; 36,5oW) from July 2004 to December 2005. All sky airglow images, meteor radar wind and TIMED/SABER satellite temperature data were used in order to investigate physical scenario of the mesospheric front. Three diff
Publicado em: 2007
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4. Padrões sinóticos de circulação atmosférica associados ao jato em baixos níveis a leste da Cordilheira ds Andes, na América do Sul / Atmospheric circulation patterns associated with the south america low level jet at east of the Andes
The objective of this studywas toidentify the atmospheric patterns circulationassociated with the South American Low-level Jet (LLJ). The zonal (u) and meridional (v) wind, geopotential height (f), temperature (T), specific humidity (q) and other variables from National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR)
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 21/06/2006
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5. Study of generation and propagation of the atmospheric gravity waves / Estudos de geração e propagação de ondas de gravidade atmosféricas
In this study the generation and propagation of the atmospheric gravity waves were investigated. The gravity waves in the mesopause region were observed by airglow all sky imaging technique at Cachoeira Paulista (23°S, 45°W), near tropic of Capricorn, and at São João do Cariri (7°S, 36°W), in the equatorial region. A reverse ray tracing method was test
Publicado em: 2004
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6. Interações trópicos-extratrópicos na escala de tempo intrassazonal durante o verão astral e seus efeitos na América do Sul / Tropical extratropical intraseasonal interactions during austraul summer and effects in south
In this study the interaction among the tropical convection in Indonesian region, the extratropical flow and the tropical convection in the South Atlantic Convergence Zone (SACZ) was analysed regarding the intraseasonal variability. The analyses were performed applying statistical techniques to the daily NCEP/NCAR reanalysis data set and to daily OLR obtaine
Publicado em: 2002
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7. Patterns of sediment dispersion coastwise the State of Bahia - Brazil
Using the average directions of the main wave-fronts which approach the coast of Bahia State - coinciding with that of the main wind occurring in the area - and of their periods, we define a wave climate model based on the construction of refraction diagrams. The resulting model of sediment transport was able to reproduce, in a general way, the sediment disp
Anais da Academia Brasileira de Ciências. Publicado em: 2000-06
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8. Critical size and curvature of wave formation in an excitable chemical medium
The critical radius for the outward propagation of waves in an excitable solution of the Belousov—Zhabotinskii reaction was experimentally analyzed and found to be ≈20 μm, being in a range predicted by theory. Thus, the wave initiation depends on the critical radius in an all-or-none fashion. For waves having high positive curvature of wave fronts, a li
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9. Spatiotemporal complexity of ventricular fibrillation revealed by tissue mass reduction in isolated swine right ventricle. Further evidence for the quasiperiodic route to chaos hypothesis.
We have presented evidence that ventricular fibrillation is deterministic chaos arising from quasiperiodicity. The purpose of this study was to determine whether the transition from chaos (ventricular fibrillation, VF) to periodicity (ventricular tachycardia) through quasiperiodicity could be produced by the progressive reduction of tissue mass. In isolated
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10. Three-dimensional waves of excitation during Dictyostelium morphogenesis.
Cells in Dictyostelium slugs follow well-defined patterns of motion. We found that the chemotactic cell response is controlled by a scroll wave of messenger concentration in the highly excitable prestalk zone of the slug that decays in the less-excitable prespore region into planar wave fronts. This phenomenon is investigated by numerical solutions of partia
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11. A theory of distortion of the reaction zone
A cylindrical detonating explosive behaves like a non-Newtonian viscous fluid emerging from a cylindrical pipe. The expression for non-Newtonian viscous flow has been applied to detonating explosives. The resultant fit to emerging flame fronts from detonation is excellent for a wide variety of detonating explosives both for transients (at various times) and
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12. Three-dimensional scroll waves of cAMP could direct cell movement and gene expression in Dictyostelium slugs.
Complex three-dimensional waves of excitation can explain the observed cell movement pattern in Dictyostelium slugs. Here we show that these three-dimensional waves can be produced by a realistic model for the cAMP relay system [Martiel, J. L. & Goldbeter, A. (1987) Biophys J. 52, 807-828]. The conversion of scroll waves in the prestalk zone of the slug into