Dynamical Transition
Mostrando 1-12 de 64 artigos, teses e dissertações.
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1. Transition from Thermokinetic to Chemical Instabilities in a Modified Sal’nikov Model
Traditionally, thermokinetic and chemical oscillations have been studied independently, but in cellular media recent studies have shown that cell’s temperature is not uniform. Thus, on this context it is possible to inquire about the influence of thermal effects on chemical oscillatory behavior and vice versa. To this end, in this paper we propose a dynami
J. Braz. Chem. Soc.. Publicado em: 2018-07
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2. Layered double hydroxides as fillers in poly(l-lactide) nanocomposites, obtained by in situ bulk polymerization
Abstract In this study in situ bulk polymerization of L-lactide filled with layered double hydroxides (LDH) was investigated. Four different LDHs intercalated with two different organic anions (salicylate and sebacate) were synthesized and characterized. After characterization, these synthetic layered compounds were used as fillers in poly(L-lactide) (PLLA)
Polímeros. Publicado em: 31/05/2016
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3. Ondas gravitacionais e o espectro de anisotropia tensorial na presença de neutrinos cosmológicos
In this work we have studied the evolution of primordial gravitational waves coupled to anisotropic stress tensor of cosmological neutrinos. As in a radiation dominated universe, in a universe dominated by radiation and matter the neutrinos can work as an effective dispersive medium for the gravitational waves, besides introduce small modifications over the
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 10/07/2012
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4. Oscillatory interaction in a Bose-Einstein condensate: collective and topological excitations / Interações oscilatórias em um condensado de Bose-Einstein: excitações coletivas e topológicas
In this work, we theoretically analyze the behavior of a Bose-Einstein condensate when it is submitted to oscillatory interactions. For that, a homogeneous magnetic field is applied, tuned near a Feshbach resonance, and then it is set to oscillate in time. This variation of the magnetic field causes a scattering length oscillation, which oscillates to intera
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 23/03/2012
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5. Transições anarmônicas em L-Cisteína: papel das interações fônon-fônon / Anharmonic transitions in L-cysteine: role of phonon-phonon interactions
Estudos teóricos e experimentais sobre as propriedades físicas das biomoléculas têm sido motivados recentemente pela busca da correlação entre as flutuações na forma/função e suas atividades bioquímicas. Estas flutuações em sistemas biológicos são mecanismos intrínsecos da atividade biomolecular. Os modos de vibração desempenham um papel im
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 05/10/2010
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6. Aspects of nonmetricity in gravity theories
In this work, we show that a class of metric-affine gravities can be reduced to a Riemann-Cartan one. The reduction is based on the cancelation of the nonmetricity against the symmetric components of the spin connection. A heuristic proof, in the Einstein-Cartan formalism, is performed in the special case of diagonal unitary tangent metric tensor. The result
Brazilian Journal of Physics. Publicado em: 2010-12
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7. Transição quântico-clássica em sistemas com propensão coletiva / Quantum-to-classical transition in systems with collective propensity
In this thesis, we studied the behavior of quantum systems which in the classical limit may exhibit either regular or chaotic behavior. Our study was based on the dynamical characterization of the, chaotic or regular, behavior of these systems in the classical limit through the analysis of the structure of phase-space distributions functions. Particularly, w
Publicado em: 2010
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8. Repulsive and attractive ferroglasses: a SAXS and XPCS study
A dynamical freezing, which is the analogous of a glass transition, is observed at large concentrations in aqueous dispersions of maghemite nanoparticles. We study experimentally the structure and the dynamical properties of two dense ferroglass-formers in two very distinct states of interparticle interaction, either strongly repulsive or attractive. The sta
Brazilian Journal of Physics. Publicado em: 2009-04
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9. Efeitos de desordem na transição metal-isolante de Mott / Efects of disorder on the Mott metal-insulator transition
We determine the phase diagram of the disordered Hubbard Model as a function of temperature and interaction strength by means of the Statistical Dynamical Mean Field Theory. The metallic and insulating spinodal lines are traced for weak and moderate disorder using Quantum Monte Carlo as the impurity solver. We find that disorder pushes the spinodal lines to
Publicado em: 2009
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10. Sistemas eletrônicos em duas dimensões : desordem e resposta dinâmica
In disordered systems the pinning strength on the carriers due to impurities or defects is one of the most important mechanisms that produce insulator behavior. A transition to a metal phase should occur if a driving field is applied to the system. In the last three decades, such transition in two-dimensional systems has attracted much attention in light of
Publicado em: 2009
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11. Dinâmica de populações: modelo predador-presa estocástico e difusivo em um reticulado / Dynamic population: Predator-prey stochastic and difusive model on a lattice
We have studied the predator-prey stochastic model defined on a lattice with first neighbour interactions. Each site of the lattice may assume one of three states: vacant, occupied by prey and occupied by predator. We have introduced a parameter that controls the possibility of difusion among sites. The model shows an oscilating phase, a non-oscilating phase
Publicado em: 2009
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12. Extended Bell´s Be-ables and Atenuattion × Amplification Competition. / Extensão dos Be-ables de Bell e Competição Atenuação x Amplificação
In the first part of this work we employ the Itô stochastic equation to extend Bells be-able interpretation of quantum mechanics to encompass dissipation, decoherence and quantum-to-classical transition through quantum trajectories. For a particular choice of the source of stochasticity, the one leading to a dissipative Lindblad type correction to the Hamil
Publicado em: 2009