949 resultados para topological equivalence of attractors


Relevância:

100.00% 100.00%

Publicador:

Resumo:

In spite of the stated Brazilian policy on medicines that their quality, effectiveness and safety should be ensured at reasonable cost, hospitals in the ANVISA Surveillance Network have been receiving notifications of technical complaints, adverse reactions and suspected therapeutic ineffectiveness (STI) of medicines. The purpose of this study was to identify the medicines notified for suspicion of therapeutic ineffectiveness, at a university hospital participating in the national Surveillance Network, and to investigate the existence of polymorphs of any of the drugs involved, by examining the literature. There were 31 notifications of STI in a period of 18 months, concerning 11 different drugs, all of which were 'similar' drugs (neither original nor licensed by originator); five of these could contain polymorphs, according to the literature. However, this does not mean that the other drugs could not contain some unknown polymorphs, more studies being needed on polymorphism, especially in the cases of reported therapeutic ineffectiveness. Therefore, tests of polymorphism should be made part of the routine quality control of the raw materials during the development of medicines and in the studies of pharmaceutical equivalence to 'reference' medicines (innovative brands). The stability test should also involve a study of polymorphism, in order to confirm the solid state stability of the drug. All these measures will assure the effectiveness of medicines, since the reproducibility in the quality of pharmaceutical products could be monitored, as well as the equivalence of each production batch with the batch selected to determine the bioequivalence with the reference brand.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A modification of the one-dimensional Fermi accelerator model is considered in this work. The dynamics of a classical particle of mass m, confined to bounce elastically between two rigid walls where one is described by a nonlinear van der Pol type oscillator while the other one is fixed, working as a reinjection mechanism of the particle for a next collision, is carefully made by the use of a two-dimensional nonlinear mapping. Two cases are considered: (i) the situation where the particle has mass negligible as compared to the mass of the moving wall and does not affect the motion of it; and (ii) the case where collisions of the particle do affect the movement of the moving wall. For case (i) the phase space is of mixed type leading us to observe a scaling of the average velocity as a function of the parameter (χ) controlling the nonlinearity of the moving wall. For large χ, a diffusion on the velocity is observed leading to the conclusion that Fermi acceleration is taking place. On the other hand, for case (ii), the motion of the moving wall is affected by collisions with the particle. However, due to the properties of the van der Pol oscillator, the moving wall relaxes again to a limit cycle. Such kind of motion absorbs part of the energy of the particle leading to a suppression of the unlimited energy gain as observed in case (i). The phase space shows a set of attractors of different periods whose basin of attraction has a complicated organization. © 2013 American Physical Society.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

We use dimensional regularization (DR) to evaluate a one-loop four-point function to order g2 in a scalar φ4 model using the light-front coordinates and performing the light-front energy variable integration in the first place. The DR in the light-front is applied to the D - 2 transverse variables. We show the equivalence of the result thus obtained with the standard DR applied to D dimensions. © 2013 American Institute of Physics.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The Kaup-Newell (KN) hierarchy contains the derivative nonlinear Schrödinger equation (DNLSE) amongst others interesting and important nonlinear integrable equations. In this paper, a general higher grading affine algebraic construction of integrable hierarchies is proposed and the KN hierarchy is established in terms of an Ŝℓ2Kac-Moody algebra and principal gradation. In this form, our spectral problem is linear in the spectral parameter. The positive and negative flows are derived, showing that some interesting physical models arise from the same algebraic structure. For instance, the DNLSE is obtained as the second positive, while the Mikhailov model as the first negative flows. The equivalence between the latter and the massive Thirring model is also explicitly demonstrated. The algebraic dressing method is employed to construct soliton solutions in a systematic manner for all members of the hierarchy. Finally, the equivalence of the spectral problem introduced in this paper with the usual one, which is quadratic in the spectral parameter, is achieved by setting a particular automorphism of the affine algebra, which maps the homogeneous into principal gradation. © 2013 IOP Publishing Ltd.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Pós-graduação em Engenharia Mecânica - FEIS

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Pós-graduação em Engenharia Mecânica - FEIS

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Pós-graduação em Matemática - IBILCE

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Pós-graduação em Matemática em Rede Nacional - IBILCE