13 resultados para Centre for Theoretical Studies

em Universidade Federal do Rio Grande do Norte(UFRN)


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The pair contact process - PCP is a nonequilibrium stochastic model which, like the basic contact process - CP, exhibits a phase transition to an absorbing state. While the absorbing state CP corresponds to a unique configuration (empty lattice), the PCP process infinitely many. Numerical and theoretical studies, nevertheless, indicate that the PCP belongs to the same universality class as the CP (direct percolation class), but with anomalies in the critical spreading dynamics. An infinite number of absorbing configurations arise in the PCP because all process (creation and annihilation) require a nearest-neighbor pair of particles. The diffusive pair contact process - PCPD) was proposed by Grassberger in 1982. But the interest in the problem follows its rediscovery by the Langevin description. On the basis of numerical results and renormalization group arguments, Carlon, Henkel and Schollwöck (2001), suggested that certain critical exponents in the PCPD had values similar to those of the party-conserving - PC class. On the other hand, Hinrichsen (2001), reported simulation results inconsistent with the PC class, and proposed that the PCPD belongs to a new universality class. The controversy regarding the universality of the PCPD remains unresolved. In the PCPD, a nearest-neighbor pair of particles is necessary for the process of creation and annihilation, but the particles to diffuse individually. In this work we study the PCPD with diffusion of pair, in which isolated particles cannot move; a nearest-neighbor pair diffuses as a unit. Using quasistationary simulation, we determined with good precision the critical point and critical exponents for three values of the diffusive probability: D=0.5 and D=0.1. For D=0.5: PC=0.89007(3), β/v=0.252(9), z=1.573(1), =1.10(2), m=1.1758(24). For D=0.1: PC=0.9172(1), β/v=0.252(9), z=1.579(11), =1.11(4), m=1.173(4)

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This work examines the connection Syndicate/teachers profession trying to unveil the important role taken over by the Syndical movement in the process of professionalization of the militant teachers. For that, it describes and analyses the historical course of three Syndicates representatives of the teachers category Associação dos Professores Licenciados da Bahia APLB; Sindicato dos Trabalhadores em Educação de Pernambuco SINTEPE; Sindicato dos Servidores Municipais de Petrolina SINDSEMP acting in the micro-region of the San Francisco Valley, especially, in the municipalities of Juazeiro Bahia , and of Petrolina Pernambuco. It concentrates its interests on the contribution of the Syndicates for the professional development of these teachers in this region analysing the aspects related to emerging conflicts into the Syndical organization, to the attitude of these entities before the educational reality to their reinvindicative struggles to the formative dimension of the group actions. This study tries to answer the following questions: How has this syndical movement of teachers of state school of S. Francisco Valley been characterized? How do their actions reflect in the formation and professionalization of the teachers? Do teachers recognize the syndicate as a constructive space for the teaching profession? The methodological trajectory was directed through a qualitative approach of an etnomethodological character, using instruments for the understanding of this reality, The treatment of the data was based on the interpretative analysis of the speeches present in documents and through answers of the interviwees, having as a reference in this analysis the theoretical studies about syndicalism and the teacher professionalization. For a conceptual construction of this work it was studied these two categories from their genesis, from the social historical evolution of their concepts and the up to date discussions that give explanations about the teachers syndical movement and about the process of teachers professionalization. As thesis of this study it was defended the idea of that the teachers syndicates have contributed expressively in the process of the construction of the teacher profession of the militant teachers of this in the micro-region of the S. Francisco Valley. Once the teachers participate actively in this movement promoted by the syndical entities, the teachers develop the critical sense of the educational realty; improve their formation and reinvindicate from the State this condition as a Right; fight for better conditions in the work; reinvindicate the salary valuation and, try to construct an image of teacher basing on a professional model. The contribution of the Syndicate in the process of teachers profissionalization, is more evident in its external dimension that chacterizes the profissionalism, on the related aspects: to the forms of participation in the definition and the management of the educational politics; to the political struggles for the achievements of the professional status, to the recognition and of his eventual valuation. The syndical actions have repercussions with less intensity in the inside dimension that defines the profissionality, in the related aspects: to the administratation of the pedagogical processes in schools and in the classroom; to the acquisition of branches of knowledges; to the epistemological criticism of the acquirements mobilized in the teaching; the curricular question to the mediation that make possible the learning at school and in the classroom

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This work examines the connection Syndicate/teachers profession trying to unveil the important role taken over by the Syndical movement in the process of professionalization of the militant teachers. For that, it describes and analyses the historical course of three Syndicates representatives of the teachers category Associação dos Professores Licenciados da Bahia APLB; Sindicato dos Trabalhadores em Educação de Pernambuco SINTEPE; Sindicato dos Servidores Municipais de Petrolina SINDSEMP acting in the micro-region of the San Francisco Valley, especially, in the municipalities of Juazeiro Bahia , and of Petrolina Pernambuco. It concentrates its interests on the contribution of the Syndicates for the professional development of these teachers in this region analysing the aspects related to emerging conflicts into the Syndical organization, to the attitude of these entities before the educational reality to their reinvindicative struggles to the formative dimension of the group actions. This study tries to answer the following questions: How has this syndical movement of teachers of state school of S. Francisco Valley been characterized? How do their actions reflect in the formation and professionalization of the teachers? Do teachers recognize the syndicate as a constructive space for the teaching profession? The methodological trajectory was directed through a qualitative approach of an etnomethodological character, using instruments for the understanding of this reality, The treatment of the data was based on the interpretative analysis of the speeches present in documents and through answers of the interviwees, having as a reference in this analysis the theoretical studies about syndicalism and the teacher professionalization. For a conceptual construction of this work it was studied these two categories from their genesis, from the social historical evolution of their concepts and the up to date discussions that give explanations about the teachers syndical movement and about the process of teachers professionalization. As thesis of this study it was defended the idea of that the teachers syndicates have contributed expressively in the process of the construction of the teacher profession of the militant teachers of this in the micro-region of the S. Francisco Valley. Once the teachers participate actively in this movement promoted by the syndical entities, the teachers develop the critical sense of the educational realty; improve their formation and reinvindicate from the State this condition as a Right; fight for better conditions in the work; reinvindicate the salary valuation and, try to construct an image of teacher basing on a professional model. The contribution of the Syndicate in the process of teachers profissionalization, is more evident in its external dimension that chacterizes the profissionalism, on the related aspects: to the forms of participation in the definition and the management of the educational politics; to the political struggles for the achievements of the professional status, to the recognition and of his eventual valuation. The syndical actions have repercussions with less intensity in the inside dimension that defines the profissionality, in the related aspects: to the administratation of the pedagogical processes in schools and in the classroom; to the acquisition of branches of knowledges; to the epistemological criticism of the acquirements mobilized in the teaching; the curricular question to the mediation that make possible the learning at school and in the classroom

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This collaborative research is a qualitative approach, from historical and cultural perspective, made about a teacher of third grade of basic education in the area of history, in the municipality of Caicó / RN. It has as objective to investigate, in a collaborative action, if the design process of teaching and learning the discipline of history based on the relationship before / after allows the development of critical reflective thinking of the teacher in school practices. The theoretical and methodological approaches are supported in the postulates of Vygotsky (1998), Rubinstein (1973) and Linblinskaia (1979), among others, whose understanding has led us to reflect if the teacher develops the reflective critical-thinking in history discipline classes. The complexity of the study led us to an analysis exercise, using different methodological procedures, such as: bibliographic review of the literature, considering also the literature of the history area, interviews, observation in the classroom, video recordings and reflective sessions, enabling clarify the construction and reconstruction of thought that the teacher had been developing during the process of teaching and learning. The test results point to a dichotomy between theory and practice, and also to a certain fragility in the position of professor in teaching and learning the discipline of history, at the third grade of basic education. The teacher recognizes that she requires a theoretical deepening with more intensity, as a process of continuous training to improve the practice of teaching in history school, though, stating in her speech that her teaching practice is based on critical reflection. However, she presents serious limitations in classroom practices. We conclude that, although she has shown willing to work on a critical perspective of reality, showed also poor change at school practices, starting to reflect about her own actions, pointing her limits and the changes needed that didn t become reality yet. It s necessary a formative process for her. The study therefore showed that even with the sessions and reflective of deepening theoretical studies, the teacher does not change its profile, while maintaining its traditional vision in any pedagogical action. This research recommends the formation of school groups for further studies and discussion on the practices of education in history area from a reflective-critical thought perspective as a mean of personal and professional development

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In the past 50 years, large efforts have been made toward the understanding of the stellar evolution. In the observational context, large sets of precise measurements of projected rotational velocity were produced, in particular by the Natal and Geneva groups. From these data, it is now possible to establish the behavior of stellar rotation from the turnoff to the red giant branch. In addition, these data have shown the role of tidal effects on stellar rotation in close binary systems. Nevertheless, relatively little attention has been paid to theoretical studies on the evolution of rotation along the HR Diagram, a topic itself directly associated to the evolution of the stars. Basically, there are two reasons for such a fact, (i) spherical symmetry is not assumed, what leads to a substantial increase in the numerical complexity of equations and (ii) non rotating models have been very successful in explaining relevant observational data, including the mass-luminosity relation and chemical abundances. In spite of these facts, it is clear that considerable work remains to be done on the role of rotation in the later stages of the evolution, where clear disagreements arise from confrontations between theoretical predictions and observations. In the present work we study the evolutionary behavior of stellar rotation along the HR Diagram, taking into account constraint conditions issued from recent observational survey of rotational velocity carried out with high precision procedures and new evolutionary codes

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A fundamental analysis on Behavioral Ecology is the construction of Activities Budget, which can be defined as the quantification of the time that each animal uses in activities that are important for its survival and reproduction. Initially developed for theoretical studies about Optimal Foraging, the construction of Activities Budgets has recently being used for analyses in Conservation Biology. However, the measurement of behavior through an adequate methodology that allows the comparison between different samples is a challenge for researchers in the area of Ethology. This problem is even bigger for the students of cetaceans behavior due to the difficulty of visualization of these animals. The present work deals with two aspects of the specialized literature on cetaceans: i) it explores possible variations of results in quantification of behavioral states decurrent of the application of different methods of data collection, and ii) it describes the activity budget of a population of Sotalia guianensis that inhabits coastal waters, south Rio Grande do Norte. The results showed that the use different methods of data collection result in significant differences, but of small scale, in the quantification of the behavioral frequency. The activity budget of Sotalia in the area here analyzed was similar to that described for other populations of this species inhabiting typically estuarine habitats. Tide and day-hour did not influence the dolphin s behavior, however, significant differences were found related to the position of the animals within the area. These results are discussed considering the dietary and behavioral flexibility of the species, contributing to the scientific knowledge and offering information that will be useful in comparative studies and for analyses on the determination of areas for species conservation

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The public and private politics that was implemented in Natal, have always been attracting, great contingent of people in search of employments. However, not always, they can attend the migratory demands. Recently, Nova Parnamirim that is situated in the municipal district of Parnamirim - RN, due to proximity with Natal, it is passing for an intensive and accelerated occupation process impelled by the urban politics that created and they determined new diversities, leaning in the growth of the modern tertiary. In this context, Nova Parnamirim is suffering, along the time, substantial transformations in your espace, so much of nature social as environmental, that are affecting in the quality of your residents' life. This fact is mainly linked in the absence of an appropriate urban planning that have to be considered as an instrument norteador of the development of the city in its constant construction process. The study has as objective to analyze the social-space dynamics of the area and their implications, identifying the principal agents that promote and they benefit of that urbanization process. For the ccomplishment of this research it was executed bibliographical readings that turn of theoretical studies about the urban subjects and enviroments, besides field activities for the rising of the data investigated in the methodological approach

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In this work it were developed synthetic and theoretical studies for clerodane-type diterpenes obtained from Croton cajucara Benth which represents one of the most important medicinal plant of the Brazil amazon region. Specifically, the majoritary biocompound 19-nor-clerodane trans-dehydrocrotonin (t-DCTN) isolated from the bark of this Croton, was used as target molecule. Semi-synthetic derivatives were obtained from t-DCTN by using the followed synthetic procedures: 1) catalytic reduction with H2, 2) reduction using NaBH4 and 3) reduction using NaBH4/CeCl3. The semi-synthetic 19-nor-furan-clerodane alcohol-type derivatives were denominated such as t-CTN, tCTN-OL, t-CTN-OL, t-DCTN-OL, t-DCTN-OL, being all of them characterized by NMR. The furan-clerodane alcohol derivatives t-CTN-OL and tCTN-OL were obtained form the semi-synthetic t-CTN, which can be isolated from the bark of C. cajucara. A theoretical protocol (DFT/B3LYP) involving the prevision of geometric and magnetic properties such as bond length and angles, as well as chemical shifts and coupling constants, were developed for the target t-DCTN in which was correlated NMR theoretical data with structural data, with satisfactory correlation with NMR experimental data (coefficients ranging from 0.97 and 0.99) and X-ray diffraction data. This theoretical methodology was also validated for all semi-synthetic derivatives described in this work. In addition, topological data from the Quantum Theory of Atoms in Molecules (QTAIM) showed the presence of H-H and (C)O--H(C) intramolecular stabilized interactions types for t-DCTN e t-CTN, contributing to the understanding of the different reactivity of this clerodanes in the presence of NaBH4.

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The discovery of giant stars in the spectral regions G and K, showing moderate to rapid rotation and single behavior, namely with constant radial velocity, represents one important topic of study in Stellar Astrophysics. Indeed, such anomalous rotation clearly violates the theoretical predictions on the evolution of stellar rotation, since in evolved evolutionary stages is expected that the single stars essentially have low rotation due to the evolutionary expansion. This property is well-established from the observational point of view, with different studies showing that for single giant stars of spectral types G and K values of the rotation are typically smaller than 5kms−1 . This Thesis seeks an effective contribution to solving the paradigm described above, aiming to search for single stars of spectral types G and K with anomalous rotation, tipically rotation of moderate to rapid, in other luminosity classes. In this context, we analyzed a large stellar sample consisting of 2010 apparently single stars of luminosity classes IV, III, II and Ib with spectral types G and K, with rotational velocity v sin i and radial velocity measurements obtained from observations made by CORAVEL spectrometers. As a first result of impact we discovered the presence of anomalous rotators also among subgiants, bright giants and supergiants stars, namelly stars of luminosity classes IV, II and Ib, in contrast to previous studies, that reported anomalous rotators only in the luminosity class III classic giants. Such a finding of great significance because it allows us to analyze the presence of anomalous rotation at different intervals of mass, since the luminosity classes considered here cover a mass range between 0.80 and 20MJ, approximately. In the present survey we discovered 1 subgiant, 9 giants, 2 bright giants and 5 Ib supergiants, in spectral regions G and K, with values of v sin i ≥ 10kms−1 and single behavior. This amount of 17 stars corresponds to a frequency of 0.8% of G and K single evolved stars with anomalous rotation in the mentioned classes of luminosities, listed at the Bright Star Catalog, which is complete to visual magnitude 6.3. Given these new findings, based on a stellar sample complete in visual magnitude, as that of the Bright Star Catalog, we conducted a comparative statistical analysis using the Kolmogorov- Smirnov test, from where we conclude that the distributions of rotational velocity, v sin i, for single evolved stars with anomalous rotation in luminosity classes III and II, are similar to the distributions of v sin i for spectroscopic binary systems with evolved components with the same spectral type and luminosity class. This vii result indicates that the process of coalescence between stars of a binary system might be a possible mechanism to explain the observed abnormal rotation in the referred abnormal rotators, at least among the giants and bright giants, where the rotation in excess would be associated with the transfer of angular momentum for the star resulting from the merger. Another important result of this Thesis concerns the behavior of the infrared emission in most of the stars with anomalous rotation here studied, where 14 stars of the sample tend to have an excess in IR compared with single stars with low rotation, within of their luminosity class. This property represents an additional link in the search for the physical mechanisms responsible for the abnormal observed rotation, since recent theoretical studies show that the accretion of objects of sub-stellar mass, such as brown dwarfs and giant planets, by the hosting star, can significantly raise its rotation, producing also a circumstellar dust disk. This last result seems to point in that direction, since it is not expected that dust disks occurring during the stage of star formation can survive until the stages of subgiants, giants and supergiants Ib. In summary, in this Thesis, besides the discovery of single G and K evolved stars of luminosity classes IV, II and Ib with anomalously high rotation compared to what is predicted by stellar evolution theory, we also present the frequency of these abnormal rotators in a stellar sample complete to visual magnitude 6.3. We also present solid evidence that coalescence processes in stellar binary systems and processes of accretion of brown dwarfs star or giant planets, by the hosting stars, can act as mechanisms responsible for the puzzling phenomenon of anomalous rotation in single evolved stars.

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Synchronous machines, widely used in energy generation systems, require constant voltage and frequency to obtain good quality of energy. However, for large load variati- ons, it is difficult to maintain outputs on nominal values due to parametric uncertainties, nonlinearities and coupling among variables. Then, we propose to apply the Dual Mode Adaptive Robust Controller (DMARC) in the field flux control loop, replacing the tradi- tional PI controller. The DMARC links a Model Reference Adaptive Controller (MRAC) and a Variable Structure Model Reference Adaptive Controller (VS-MRAC), incorpora- ting transient performance advantages from VS-MRAC and steady state properties from MRAC. Moreover, simulation results are included to corroborate the theoretical studies.

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In the midst of growing preservationist awareness, regarding methods of architectural intervention of buildings with a recognized heritage value, there are numerous approaches on how the original heritage value can be protected. However, can these intervention projects be differentiated? Is it possible to identify how they differ (if in fact they do) from an architectural project not related to preservation? Although there are numerous theoretical studies regarding methods utilized in architectonical projects, there appear to be a lack of studies focused on an architectural intervention exclusively focused on areas or edifications that have a recognized heritage value, thereby requiring a reflection on which methodological procedures in an architectonical project serve the purpose of the preservation of the historical aspects. This discussion is of even greater importance because, at the national level, some recent discussions on this type of architectural design seem arbitrary and lack methodological rigor. Therefore, this research attempts to focus equally on the theoretical-methodological practices of preservation as well as the architectural project methods. In an attempt to address these aspects, the focus of this research centers on the case studies of the intervention projects of the maritime passenger terminal of Natal (Terminal Marítimo de Passageriros de Natal), the old government hall (Palacio do Governo - EDTAM) and the old central hotel (Hotel Central) which are situated in the area known as the historic downtown of the city of Natal, within the federal heritage protection polygon. The analyses of these is intended to identify what methodological procedures were recorded in the final product (in the graphical representation of the architectural design and other documents) delivered to IPHAN / RN, the body responsible for review and approval of these architectural projects, noting whether such procedures appear, in some way, in the final product, and if an understanding of the complexity of preservation is evident. The analyses of these projects corroborate the hypothesis that there are unique characteristics, which must be addressed in the intervention project for preservation when compared to new project design. The main characteristic to be addressed is related to the very nature of the project. It is inherent in the dialectical relationship between the need to preserve (the identified heritage values) and the need to modernize (making adaptations to contemporary life). This relationship, denominated in this dissertation as "radical restraint", must, or at least should, guide the actions in the project as well as the technical analyses of the preservationist organization. However, this radical restriction appears more evident in the guidelines put forth by legislators than in the decisions of designers. These legislators require the presentation of documents, aimed at identifying and contextualizing intervention (Ordinance No. 420 of December 22, 2010), that grant (or should grant) assistance in the decision making process. It was evident in the analyses of these documents that there existed a disconnect between the documents produced and the decisions made in the project. This fact can be seen in the total absence of dialogue about theoretical-methodological preservationist principles, which, in our view, is an essential element of the methodological procedures of the intervention project needed to guide the legislative and project design discussions.

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Some of the current discussions in the teaching of Portuguese Language (LP) pertain to how the school should deal with the phenomenon of language variation in the classroom. In 2010, for example, an explosion of talk took over the academic corridors: a book, entitled "Por uma vida melhor", the collection "Viver, Aprender", published by the MEC (Ministry of Education and Culture) to students EJA (Youth and Adults) brought notions regarding linguistic variation, even in their first chapter. In it is clear the notion that it is possible to make use of structures as "pretty boy", instead of "pretty boys", depending on the context in which such use is insert. Therefore, the discussions focused around the notions of variety cultivated, standard and popular measuring them to the possibilities of linguistic appropriateness. The community was surprised by the defense of the "power" to use, since it would be the school space to teach a standard "default", and not the possibility of legitimate use of grammatical patterns that clashed with those recommended in traditional grammars. The television media has been responsible for a major blaze that MEC had endorsed the use in schools of a book that legitimized such linguistic patterns. The quarrel was released on Youtube and in that space, netizens expressed themselves for or against the proposal of LD often directing the discussion to questions of a purely political. We observed that, on one side, loomed arguments related to Sociolinguistics (BAGNO , 2002, 2003, 2007, 2009; BAGNO, M.; STUBBS, M., Gagne, G., 2006; Bortoni - RICARDO, S.M., 2008; Tarallo, F., 1982; U. Weinreich, MARVIN I. HERZOG, Labov, W., 1968, Labov 1972, etc.); another, arguments concentrated on defending the school is the area of language teaching standard, and not fit to bring certain discussions within an LD. It was from these words, that this research was born. Interested in the particular way that the community media, which seemed to have no training in linguistics, understand the concepts of right, wrong, appropriate and inappropriate, so intimate in academic circles. Our thoughts take as reference the theoretical studies on the question of sociolinguistic variation and education, official documents that guide the "work" with the Portuguese language in the classroom, like the NCP (National Curriculum) and Curriculum Proposal for Education Youth and Adult (PCEJA). In our analysis, we found that LD" For a better life "makes no apology for teaching the "error", but it raises discussions about the possibility of "change", linked to factors and different order. We realize how significant it is to observe how speakers of a language are positioned in relation to language teaching which they are not speakers and scholars. Our study showed that certain issues regarding the teaching of the Portuguese language, as is the case of linguistic variation, points are far from being resolved, either for linguists and/or grammarians, whether for language speakers.

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The pair contact process - PCP is a nonequilibrium stochastic model which, like the basic contact process - CP, exhibits a phase transition to an absorbing state. While the absorbing state CP corresponds to a unique configuration (empty lattice), the PCP process infinitely many. Numerical and theoretical studies, nevertheless, indicate that the PCP belongs to the same universality class as the CP (direct percolation class), but with anomalies in the critical spreading dynamics. An infinite number of absorbing configurations arise in the PCP because all process (creation and annihilation) require a nearest-neighbor pair of particles. The diffusive pair contact process - PCPD) was proposed by Grassberger in 1982. But the interest in the problem follows its rediscovery by the Langevin description. On the basis of numerical results and renormalization group arguments, Carlon, Henkel and Schollwöck (2001), suggested that certain critical exponents in the PCPD had values similar to those of the party-conserving - PC class. On the other hand, Hinrichsen (2001), reported simulation results inconsistent with the PC class, and proposed that the PCPD belongs to a new universality class. The controversy regarding the universality of the PCPD remains unresolved. In the PCPD, a nearest-neighbor pair of particles is necessary for the process of creation and annihilation, but the particles to diffuse individually. In this work we study the PCPD with diffusion of pair, in which isolated particles cannot move; a nearest-neighbor pair diffuses as a unit. Using quasistationary simulation, we determined with good precision the critical point and critical exponents for three values of the diffusive probability: D=0.5 and D=0.1. For D=0.5: PC=0.89007(3), β/v=0.252(9), z=1.573(1), =1.10(2), m=1.1758(24). For D=0.1: PC=0.9172(1), β/v=0.252(9), z=1.579(11), =1.11(4), m=1.173(4)