662 resultados para Simetrias de Lorentz e CPT


Relevância:

10.00% 10.00%

Publicador:

Resumo:

O estudo tem como objetivo identificar na evolução das políticas públicas para erradicação do trabalho escravo os diferentes atores e a dinâmica das relações entre eles. A ocorrência da escravidão contemporânea pôde se dar a partir da contribuição de alguns fatores estruturais e conjunturais, tais como o processo de aprofundamento do capitalismo e de modernização conservadora no país e especificamente na agricultura e relações políticas, sociais e históricas que perpetuam a enorme concentração fundiária brasileira. Além disso, algumas relações pessoais, sociais e políticas de intermediação de interesses entre Estado e sociedade, tais como clientelismo e patronagem e redes de políticas, de modo geral e de forma mais específica nas políticas agrárias, também interferem no desenvolvimento dos processos de políticas públicas e dentre elas nas políticas de combate ao trabalho escravo. Desse modo, a dissertação tem como problema a investigação da dinâmica das relações entre atores governamentais e nãogovernamentais na formulação e implantação das políticas públicas de erradicação ao trabalho escravo no Brasil. Para tanto, o estudo foi realizado por meio de pesquisa bibliográfica, documental e de campo, tendo entrevistado os seguintes atores políticos: MTE, MPT, OIT, CPT, ONG Repórter Brasil, GPTEC e OAB. Os dados foram analisados pelo método de análise de conteúdo, sob um viés qualitativo. Os resultados da pesquisa permitiram identificar a formação de múltiplas redes entre os atores governamentais e não-governamentais envolvidos nesta questão, demonstrando certa divisão entre as redes que atuam lutando pelo combate ao trabalho escravo e outras que se posicionam como uma certa resistência a esse combate, devido a interesses econômicos e políticos, revelando, assim, um jogo de forças que ora apresenta avanços e conquistas, ora mostra retrocessos ou estagnação na luta contra a escravidão contemporânea brasileira.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Uma análise da estabilidade não-linear de feixes com seção transversal circular considerando perturbações sem simetria axial é executada. Mostra-se que as oscilações simétricas oficialmente circulares de um feixe podem induzir oscilações não-lineares do tipo anti-simétrica(elípticas), com um conseqüente aumento do tamanho do feixe ao logo de uma direção preferencial. O mecanismo da instabilidade e sua relevância às perdas de partícula no feixe são discutidos.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Este trabalho teve por objetivo estimar equações de regressão linear múltipla tendo, como variáveis explicativas, as demais características avaliadas em experimento de milho e, como variáveis principais, a diferença mínima significativa em percentagem da média (DMS%) e quadrado médio do erro (QMe), para peso de grãos. Com 610 experimentos conduzidos na Rede de Ensaios Nacionais de Competição de Cultivares de Milho, realizados entre 1986 e 1996 (522 experimentos) e em 1997 (88 experimentos), estimaram-se duas equações de regressão, com os 522 experimentos, validando estas pela análise de regressão simples entre os valores reais e os estimados pelas equações, com os 88 restantes, observando que, para a DMS% a equação não estimava o mesmo valor que a fórmula original e, para o QMe, a equação poderia ser utilizada na estimação. Com o teste de Lilliefors, verificou-se que os valores do QMe aderiam à distribuição normal padrão e foi construída uma tabela de classificação dos valores do QMe, baseada nos valores observados na análise da variância dos experimentos e nos estimados pela equação de regressão.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Les connaissances de la tradition et position de la Science dehors pour un non-hiérarchique dialoguez qui frappe pour les distinguer mais ils sont undésavouer inséparable étant donné les compléments ils composent. Cet essai assume la possibilité de ce roi de dialogue dans un place spéciale: la classe. Sur ce qui vient au connaissance de la tradition, le centre remarquable est pour la construction de bateaux du travail manuel, una pratique culturellement déployé dans la ville d'Abaetetuba, dans le État de Pará, Brésil. En revanche, la Science est concentrée par le le contenu d'école a adopté dans l'Ensino Fundamental (École primaire). La construction du dialogue est faite en utilisant des activités de l'enseignement qui accentuez des aspects géométriques (solide, géométrique, angles et symétries) aussi bien que par information qui implique le tableau, poésie, histoire, géographie et physique - les deux inspiré dans le chiffre de bateau résumé dans un CD-ROM interactif. Les activités ont eu lieu dans D'Escola Ensino Pedro Teixeira Fondamental (Abaetetuba-Pa), avec étudiants du 6e niveau (plus spécifiquement avec un groupe de 13 étudiants) d'août à octobre2004. Ethnomathématiques et transdisciplinarité sont le support théorique sous-jacent du projet. Dans résumé, c'est possible pour dire que l'interaction entre Science et Tradition, à travers activités au-delà lesquelles vont le le contenu a restreint à mathématiques d'école, contribuées à,: identifiez le contenu a appris pas sur dans série antérieure; renouveler le rôle joué par école dans ses fonctions didactique pédagogiques; réduire le isolement entre information passée historique et les étudiants présent culturel; indiquer des obstacles à l'érudition des mathématiques intéresser aux aspects cognitifs et behavioristes; et provoquer un participation affective qui rôle principal à la qualité d'apprendre l'école contenu aussi bien que les connaissances de la tradition

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This thesis aims to investigate the Agronomy course in the perspective of the graduation course for the settlers of the Universidade Federal do Pará- Marabá. This course requires a partnership with the social movements of the North region of the country, with the purpose to understand knowledge production and how learning process occurs from the point of interaction and reliable relationships which are established in the organization during the course. The base of theses studies is to reflect of how the dialogue and learning processes occurred during the Agronomy course and resulted in changing in the teachers behavior and in the other integrated members of the group and mainly in the graduating settlers students. These changings happens as a consenquence of the dialogue production between the most varied areas, different people and institutions which take collective decisions. I observe educational actions, researches, extention concepts of extension and also development researches presented in the educative actions discussed by Freire (1985), Simões (2001, 2003) e de Amartya Sen (2000). The theory in which I am basing these studies are based in Boaventura de Souza Santos Simões (2001, 2003) and Amartya Sen (2000). Methodologically I analyse knowledge production by sudying the thesis and scientific works related to rural education, social movements, university and higher education in the last 20 years. I analyze the scientific works of all settler students, and besides, I do open interviews with the students, as well as, with the teachers and the leaders of social movements (MST, FETAGRI, CPT, EFA/FATA). I organize and analyze all the speeches from the ecological knowledge as defined by Boaventura de Souza Santos (2006). Finally, I visit five towns of municipal districts of the southeast of Pará, which represents the final methodological part of the research, in order to verify in loco the practices of the experiments purposed as final activity of the Agronomy course. I organize the work in five areas composed by the occupational process and the initiatives which emerged from them; development model and the social and environmental consequences; I also organize the university role and the relationship established between people and institutions which gave origin to the Agronomy course of UFPA and the programs developed in the region; conjuncture of creation of the groups of settled students, curriculum, principles and focus on the course and the experienced actions; developed practices in the course and the relations of reliability experienced internally and externally to the Academy, the learning and dialogue promoted by the course. I believe that the dialogue has caused changes in the organization of the knowledge and in the educative practices of the teachers, as well as, in the socio-productive practices of the regressed settled students

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The usual Ashkin-Teller (AT) model is obtained as a superposition of two Ising models coupled through a four-spin interaction term. In two dimension the AT model displays a line of fixed points along which the exponents vary continuously. On this line the model becomes soluble via a mapping onto the Baxter model. Such richness of multicritical behavior led Grest and Widom to introduce the N-color Ashkin-Teller model (N-AT). Those authors made an extensive analysis of the model thus introduced both in the isotropic as well as in the anisotropic cases by several analytical and computational methods. In the present work we define a more general version of the 3-color Ashkin-Teller model by introducing a 6-spin interaction term. We investigate the corresponding symmetry structure presented by our model in conjunction with an analysis of possible phase diagrams obtained by real space renormalization group techniques. The phase diagram are obtained at finite temperature in the region where the ferromagnetic behavior is predominant. Through the use of the transmissivities concepts we obtain the recursion relations in some periodical as well as aperiodic hierarchical lattices. In a first analysis we initially consider the two-color Ashkin-Teller model in order to obtain some results with could be used as a guide to our main purpose. In the anisotropic case the model was previously studied on the Wheatstone bridge by Claudionor Bezerra in his Master Degree dissertation. By using more appropriated computational resources we obtained isomorphic critical surfaces described in Bezerra's work but not properly identified. Besides, we also analyzed the isotropic version in an aperiodic hierarchical lattice, and we showed how the geometric fluctuations are affected by such aperiodicity and its consequences in the corresponding critical behavior. Those analysis were carried out by the use of appropriated definitions of transmissivities. Finally, we considered the modified 3-AT model with a 6-spin couplings. With the inclusion of such term the model becomes more attractive from the symmetry point of view. For some hierarchical lattices we derived general recursion relations in the anisotropic version of the model (3-AAT), from which case we can obtain the corresponding equations for the isotropic version (3-IAT). The 3-IAT was studied extensively in the whole region where the ferromagnetic couplings are dominant. The fixed points and the respective critical exponents were determined. By analyzing the attraction basins of such fixed points we were able to find the three-parameter phase diagram (temperature £ 4-spin coupling £ 6-spin coupling). We could identify fixed points corresponding to the universality class of Ising and 4- and 8-state Potts model. We also obtained a fixed point which seems to be a sort of reminiscence of a 6-state Potts fixed point as well as a possible indication of the existence of a Baxter line. Some unstable fixed points which do not belong to any aforementioned q-state Potts universality class was also found

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In this work, we have studied the acoustic phonon wave propagation within the periodic and quasiperiodic superlattices of Fibonacci type. These structures are formed by phononic crystals, whose periodicity allows the raise of regions known as stop bands, which prevent the phonon propagation throughout the structure for specific frequency values. This phenomenon allows the construction of acoustic filters with great technological potential. Our theoretical model were based on the method of the transfer matrix, thery acoustics phonons which describes the propagation of the transverse and longitudinal modes within a unit cell, linking them with the precedent cell in the multilayer structure. The transfer matrix is built taking into account the elastic and electromagnetic boundary conditions in the superllatice interfaces, and it is related to the coupled differential equation solutions (elastic and electromagnetic) that describe each model under consideration. We investigated the piezoelectric properties of GaN and AlN the nitride semiconductors, whose properties are important to applications in the semiconductor device industry. The calculations that characterize the piezoelectric system, depend strongly on the cubic (zinc-bend) and hexagonal (wurtzite) crystal symmetries, that are described the elastic and piezoelectric tensors. The investigation of the liquid Hg (mercury), Ga (gallium) and Ar (argon) systems in static conditions also using the classical theory of elasticity. Together with the Euler s equation of fluid mechanics they one solved to the solid/liquid and the liquid/liquid interfaces to obtain and discuss several interesting physical results. In particular, the acoustical filters obtained from these structures are again presented and their features discussed

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The paper presents the results of instrumented compression load tests carried out in three uncased cast-in-place piles (pounded piles, called apiloadas in Brazil) which is largely used in interior part of the state of São Paulo. The tests were conducted with the soil in the natural condition and after soaking with water, before loading, in order to evaluate the influence of the soil collapsibility in the results. The values of the ultimate loads (total, point and lateral loads) obtained in the tests are presented and compared with the values predicted by empirical methods that utilize SPT and CPT results.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

For redundant second-class constraints the Dirac brackets cannot be defined and new brackets must be introduced. We prove here that the Jacobi identity for the new brackets must hold on the surface of the second-class constraints. In order to illustrate our proof we work out explicitly the cases of a fractional spin particle in 2 + 1 dimensions and the original Brink-Schwarz massless superparticle in D = 10 dimensions in a Lorentz-covariant constraints separation.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Dirac-like monopoles are studied in three-dimensional Abelian Maxwell and Maxwell-Chern-Simons models. Their scalar nature is highlighted and discussed through a dimensional reduction of four-dimensional electrodynamics with electric and magnetic sources. Some general properties and similarities whether considered in Minkowski or Euclidean space are mentioned. However, by virtue of the structure of the space-time in which they are studied, a number of differences among them occur. Furthermore, we pay attention to some consequences of these objects when they act upon the usual particles. Among other subjects, special attention is given to the study of a Lorentz-violating nonminimal coupling between neutral fermions and the field generated by a monopole alone. In addition, an analogue of the Aharonov-Casher effect is discussed in this framework.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Exact analytic solutions are found to the Dirac equation for a combination of Lorentz scalar and vector Coulombic potentials with additional non-Coulombic parts. An appropriate linear combination of Lorentz scalar and vector non-Coulombic potentials, with the scalar part dominating, can be chosen to give exact analytic Dirac wave functions.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The problem of confinement of spinless particles in 1 + 1 dimensions is approached with a linear potential by considering a mixing of Lorentz vector and scalar couplings. Analytical bound-states solutions are obtained when the scalar coupling is of sufficient intensity compared to the vector coupling. (c) 2005 Elsevier B.V. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The problem of confinement of fermions in 1 + 1 dimensions is approached with a linear potential in the Dirac equation by considering a mixing of Lorentz vector and scalar couplings. Analytical bound-states solutions are obtained when the scalar coupling is of sufficient intensity compared to the vector coupling. (C) 2002 Elsevier B.V. B.V. All rights reserved.