Função de distribuição generalizada aplicada à velocidade de rotação estelar

In the present work we use a Tsallis maximum entropy distribution law to fit the observations of projected rotational velocity measurements of stars in the Pleiades open cluster. This new distribution funtion which generalizes the Ma.xwel1-Boltzmann one is derived from the non-extensivity of the Boltzmann-Gibbs entropy. We also present a oomparison between results from the generalized distribution and the Ma.xwellia.n law, and show that the generalized distribution fits more closely the observational data. In addition, we present a oomparison between the q values of the generalized distribution determined for the V sin i distribution of the main sequence stars (Pleiades) and ones found for the observed distribution of evolved stars (subgiants). We then observe a correlation between the q values and the star evolution stage for a certain range of stel1ar mass

Fractais e percolação na recuperação de Petróleo

The complex behavior of a wide variety of phenomena that are of interest to physicists, chemists, and engineers has been quantitatively characterized by using the ideas of fractal and multifractal distributions, which correspond in a unique way to the geometrical shape and dynamical properties of the systems under study. In this thesis we present the Space of Fractals and the methods of Hausdorff-Besicovitch, box-counting and Scaling to calculate the fractal dimension of a set. In this Thesis we investigate also percolation phenomena in multifractal objects that are built in a simple way. The central object of our analysis is a multifractal object that we call Qmf . In these objects the multifractality comes directly from the geometric tiling. We identify some differences between percolation in the proposed multifractals and in a regular lattice. There are basically two sources of these differences. The first is related to the coordination number, c, which changes along the multifractal. The second comes from the way the weight of each cell in the multifractal affects the percolation cluster. We use many samples of finite size lattices and draw the histogram of percolating lattices against site occupation probability p. Depending on a parameter, ρ, characterizing the multifractal and the lattice size, L, the histogram can have two peaks. We observe that the probability of occupation at the percolation threshold, pc, for the multifractal is lower than that for the square lattice. We compute the fractal dimension of the percolating cluster and the critical exponent β. Despite the topological differences, we find that the percolation in a multifractal support is in the same universality class as standard percolation. The area and the number of neighbors of the blocks of Qmf show a non-trivial behavior. A general view of the object Qmf shows an anisotropy. The value of pc is a function of ρ which is related to its anisotropy. We investigate the relation between pc and the average number of neighbors of the blocks as well as the anisotropy of Qmf. In this Thesis we study likewise the distribution of shortest paths in percolation systems at the percolation threshold in two dimensions (2D). We study paths from one given point to multiple other points. In oil recovery terminology, the given single point can be mapped to an injection well (injector) and the multiple other points to production wells (producers). In the previously standard case of one injection well and one production well separated by Euclidean distance r, the distribution of shortest paths l, P(l|r), shows a power-law behavior with exponent gl = 2.14 in 2D. Here we analyze the situation of one injector and an array A of producers. Symmetric arrays of producers lead to one peak in the distribution P(l|A), the probability that the shortest path between the injector and any of the producers is l, while the asymmetric configurations lead to several peaks in the distribution. We analyze configurations in which the injector is outside and inside the set of producers. The peak in P(l|A) for the symmetric arrays decays faster than for the standard case. For very long paths all the studied arrays exhibit a power-law behavior with exponent g ∼= gl.

Processos difusivos generalizados

We investigate several diffusion equations which extend the usual one by considering the presence of nonlinear terms or a memory effect on the diffusive term. We also considered a spatial time dependent diffusion coefficient. For these equations we have obtained a new classes of solutions and studied the connection of them with the anomalous diffusion process. We start by considering a nonlinear diffusion equation with a spatial time dependent diffusion coefficient. The solutions obtained for this case generalize the usual one and can be expressed in terms of the q-exponential and q-logarithm functions present in the generalized thermostatistics context (Tsallis formalism). After, a nonlinear external force is considered. For this case the solutions can be also expressed in terms of the q-exponential and q-logarithm functions. However, by a suitable choice of the nonlinear external force, we may have an exponential behavior, suggesting a connection with standard thermostatistics. This fact reveals that these solutions may present an anomalous relaxation process and then, reach an equilibrium state of the kind Boltzmann- Gibbs. Next, we investigate a nonmarkovian linear diffusion equation that presents a kernel leading to the anomalous diffusive process. Particularly, our first choice leads to both a the usual behavior and anomalous behavior obtained through a fractionalderivative equation. The results obtained, within this context, correspond to a change in the waiting-time distribution for jumps in the formalism of random walks. These modifications had direct influence in the solutions, that turned out to be expressed in terms of the Mittag-Leffler or H of Fox functions. In this way, the second moment associated to these distributions led to an anomalous spread of the distribution, in contrast to the usual situation where one finds a linear increase with time

Ánálise da capacidade funcional e da distribuição regional da ventilação pulmonar em pacientes com doença de chagas

INTRODUCTION: Cardiac and pulmonary manifestations of the Chagas disease (CD) affect between 20-30% of the infected subjects. The chronic Chagas cardiomyopathy (CCC) has some peculiarities such as arrhythmias and, especially heart failure (HF) and is potentially lethal due to left ventricular dysfunction. How respiratory disorders, patients get progressive loss of functional capacity, which contributes to a poor quality of life related to disease. Measurements of lung volume by the movement of the chest wall surface are an alternative evaluation of lung function and kinematics of complex thoracoabdominal for these patients. OBJECTIVE: evaluate the kinematics of the thoracoabdominal complex through the regional pulmonary volumes and to correlate with functional evaluation of the cardiorrespiratory system in patients with Chagas disease at rest. MATERIALS AND METHODS: a cross-section study with 42 subjects had been divided in 3 groups, 15 composed for patients with CCC, 12 patients with HF of different etiologies and 15 healthful presented control group. An optoelectronic plethysmography (POE), Minnesota questionnaire, six minute walk test, spirometer and manovacuometer was used. RESULTS: It was observed in the 6MWT where group CRL presented greater distance 464,93±44,63m versus Group HF with 399,58± 32,1m (p=0,005) and group CCC 404±68,24m (p=0,015), both the groups presented difference statistics with regard to Group CRL. In the manovacuometer 54,59±19,98; of the group CCC and 42,11±13,52 of group IC found group CRL presented 81,31±15,25 of the predicted versus, presenting in relation to group CRL. In the POE it observed a major contribution in abdominal compartment in patients with IC if compared like CCC and control groups. On the basis of the questionnaire of quality of life of Minessota, verified a low one groups CCC and IC 43,2±15,2 and 44,4±13,1, respectively (p<0,05) when compared with the control group (19,6±17,31). CONCLUSION: it seems that the patients with CCC possess same functional and respiratory characteristics, observed for the POE, 6MWT, manovacuometer and spirometer to the patients of group HF, being able to consider similar interventions for this complementary group as therapeutical of this neglected disease

Ssitema integrado de gestão pública: proposta de implantação de um sistema integrado de gestão, autuação e distribuição de termos circunstanciados e inquéritos policiais entre os juizados especiais criminais e delegacias de Natal

Universidade Federal do Rio Grande do Norte