Efeito do campo elétrico em nanocones formados por aln e BN: um estudo por primeiros princípios

The development of computers and algorithms capable of making increasingly accurate and rapid calculations as well as the theoretic foundation provided by quantum mechanics has turned computer simulation into a valuable research tool. The importance of such a tool is due to its success in describing the physical and chemical properties of materials. One way of modifying the electronic properties of a given material is by applying an electric field. These effects are interesting in nanocones because their stability and geometric structure make them promising candidates for electron emission devices. In our study we calculated the first principles based on the density functional theory as implemented in the SIESTA code. We investigated aluminum nitride (AlN), boron nitride (BN) and carbon (C), subjected to external parallel electric field, perpendicular to their main axis. We discuss stability in terms of formation energy, using the chemical potential approach. We also analyze the electronic properties of these nanocones and show that in some cases the perpendicular electric field provokes a greater gap reduction when compared to the parallel field

Cálculos AB initio de propriedades estruturais, eletrônicas e ópticas de colmpostos CaXo3 (X=Si, Ge, Sn)

In this work we present a study of structural, electronic and optical properties, at ambient conditions, of CaSiO3, CaGeO3 and CaSnO3 crystals, all of them a member of Ca-perovskite class. To each one, we have performed density functional theory ab initio calculations within LDA and GGA approximations of the structural parameters, geometry optimization, unit cell volume, density, angles and interatomic length, band structure, carriers effective masses, total and partial density of states, dielectric function, refractive index, optical absorption, reflectivity, optical conductivity and loss function. A result comparative procedure was done between LDA and GGA calculations, a exception to CaSiO3 where only LDA calculation was performed, due high computational cost that its low symmetry crystalline structure imposed. The Ca-perovskite bibliography have shown the absence of electronic structure calculations about this materials, justifying the present work

Sistemas Nanoestruturados: Heteroestruturas Quasi-Periódicas de Nitretos e Cálculos Ab initio em Polimorfos CaCO3

The physical properties and the excitations spectrum in oxides and semiconductors materials are presented in this work, whose the first part presents a study on the confinement of optical phonons in artificial systems based on III-V nitrides, grown in periodic and quasiperiodic forms. The second part of this work describes the Ab initio calculations which were carried out to obtain the optoeletronic properties of Calcium Oxide (CaO) and Calcium Carbonate (CaCO3) crystals. For periodic and quasi-periodic superlattices, we present some dynamical properties related to confined optical phonons (bulk and surface), obtained through simple theories, such as the dielectric continuous model, and using techniques such as the transfer-matrix method. The localization character of confined optical phonon modes, the magnitude of the bands in the spectrum and the power laws of these structures are presented as functions of the generation number of sequence. The ab initio calculations have been carried out using the CASTEP software (Cambridge Total Sequential Energy Package), and they were based on ultrasoft-like pseudopotentials and Density Functional Theory (DFT). Two di®erent geometry optimizations have been e®ectuated for CaO crystals and CaCO3 polymorphs, according to LDA (local density approximation) and GGA (generalized gradient approximation) approaches, determining several properties, e. g. lattice parameters, bond length, electrons density, energy band structures, electrons density of states, e®ective masses and optical properties, such as dielectric constant, absorption, re°ectivity, conductivity and refractive index. Those results were employed to investigate the confinement of excitons in spherical Si@CaCO3 and CaCO3@SiO2 quantum dots and in calcium carbonate nanoparticles, and were also employed in investigations of the photoluminescence spectra of CaCO3 crystal

Estudo teórico das propriedades eletrônicas e termodinâmicas de nanofitas quasiperiódicas BCN

Nanoscale materials composed of boron, nitrogen, and carbon have unique properties and may be useful in new technologies. In this thesis, we investigate some properties of BCN nanoribbons constructed according to the Fibonacci quasiperiodic sequence. We analyze properties such as structural stability, electronic density of states, electronic specific heat, band structure, and energy band gap. We have performed first-principles calculations based on density functional theory implemented in the SIESTA code. The results showed that nanoribbons present a fixed value of the formation energy. The electronic density of states was used to calculate the specific heat. We found an oscillatory behavior of the electronic specific heat, in the low temperature regime. We analyze the electronic band structure to determine the energy band gap. The energy band gap oscillates as a function of the Fibonacci generation index n. Our work suggest that appropriate choice of the building block materials of the quasiperiodic sequence, may lead to a tuneable band gap of the quasiperiodic nanoribbons.

Inclusão de alunos com deficiência no ensino superior: ações no contexto da Universidade Federal do Rio Grande do Norte

Aborda a educação inclusiva no âmbito da Universidade Federal do Rio Grande do Norte (UFRN), com vistas às ações estruturantes para alunos com deficiência, no período de 2001 a 2007. O seu objetivo principal é situar as ações que foram desenvolvidas por essa universidade e, ainda, as que estão em andamento e que privilegiam o acesso e a qualidade do ensino, particularmente, a esses alunos. Este estudo caracteriza-se também por uma abordagem qualitativa e exploratória, por meio do qual empregou-se a análise documental. Os primeiros resultados apontam para ações de diversas naturezas, tais como: criação de uma comissão para elaborar diretrizes gerais e propor ações acadêmicas para a educação especial; realização de Seminários de Educação Inclusiva; criação do ‘espaço inclusivo” na biblioteca central; adequação e construção de ambientes acessíveis; aprovação de projeto no Programa Incluir, dentre outras. Portanto, a partir dessas ações a UFRN demonstra ser fiel aos princípios que norteiam a construção de um sistema educacional democrático e inclusivo, ao buscar garantir a qualidade da oferta e do acesso aos seus cursos, respeitando a diversidade de todos os que nela ingressam

Ajuste estrutural e educação superior no Brasil: princípios negados

SILVA, Hiran Francisco Oliveira Lopes da. A juste estruturale educação superior no Brasil: princípios negados. 206 f., 2007. Tese (Doutorado em Educação) - Universidade Federal da Paraiba, João Pessoa, 2007.

Círculos ao invés de linhas: em busca de valores e princípios estruturantes da gestão social. Projeto juventude, participação e autonomia (Instituto Universidade Popular - UNIPOP)

The organizations are characterized as dynamic spaces, they are being revisited and redefined, because they constitute structural human spaces and new vain outlines won expression. As it begins, of the non consensus in its conception, it is explicit the complexity degree that is identified in the plurality and diversity, brought by the people that compose them, characterizing it as accomplishment space, of happiness and also of conflict, of relationships of power and organizational limits and from birth and burial of faiths, values, norms, symbols, knowledge and rituals, therefore, deeply human. In that way, to know the administration of the organization is preponderant condition for the format of the human relationships to be delineated in its living. Like this the work makes an option in knowing the social administration, this work tries to know and analyze the values and beginnings of the social administration; revealling characteristics and specificities of the organizational performance of UNIPOP that contribute to the formation of the conception of Social Administration, it tends as source of the information the managers of the institution; to identify the formative values of UNIPOP that contribute to the youths' partner-political action in the community, tends for reference the current students of the organization and last to evaluate values structurates and supporting that interconnection between the organizational Administration, formation youth's program, participation and autonomy and attendance, starting from the existences gained by the exits, of that program. This way, the research will be qualitative, looking for understanding starting from their documents, the existence of those values

Identificação dos princípios ativos presentes no extrato etanólico de cereus jamacaru e avaliação em ratos dos possíveis efeitos tóxicos e/ou comportamentais da exposição prolongada

Conselho Nacional de Desenvolvimento Científico e Tecnológico

A economia social e os estados do cooperativismo: ascensão ou declínio dos princípios do cooperativismo em empreendimentos autogestionários

Crisis in the capitalist system of production, contributes to appearance of social enterprises. In spite of, to believe these undertakings were to promote a true revolution that supply alternatives to consolidation of a socialist society, which it wasn t succeed. The cooperatives which was our object of study, get appearance in the middle of the capitalist system of production in a disorganized way, therefore, many of them Just get rich or they became true work machines and exploration of the human work. This study has like main objective: Do cooperatives have knowledge and/or they pratice rudments of the cooperativist moviment?. Get some conclusions, the cooperatives of work come promoting a decline of the rudments of the cooperativism and they don t have a knowledge about the rudments of the cooperativism and they don t pratice the same ones, instead of, the ccoperative of production comes promoting the appearance of the self-management idealism which they know the rudments of thecooperativism and they pratice the same ones

Reforma administrativa e gestão de políticas sociais em Mossoró: a falácia dos atores institucionais e sociais

The thesis entitled The administrative reform and social political management in Mossoró: the institutional and social staff's falacy. Comprehends a moment of apprehensiveness and analysis in the reestrcturing process of the city, whose process will show the formation of strategies and deployment of its relation with the social political affectiveness. It represents a single moment in the approach of such a kind of experience in the city. The analysis starts from the third mandate of the Mayor Rosalba Ciarlini Rosado, during the quadriennium 2001/2004, for being the time in which the public management got materialized, such as in the operational way of the social politics. For that, we delimitate this study in two distinct moments: the first one refers to the reform elaboration from the creation of the additional law nº 001/2000 GP/PMM: the second one refers to a practical reform from the social and institutional staff's speech. Within that scenary it was seen that the approaching, though partially, the State Reform and, consequently, the master plan of the state apparatus, which were made of theoretical matrices of such a project locally. However, that is a complex experience, that required the use of field and documental research for the proposed investigation and at the same time, prove the guiding hypothesis of it, what means a grouping of areas like: education, healthy, and social development in only one department City Citizenship Department that is able to materialize a new intitutional arrangement, according to the management principles in the public administration at the govern local level, configuring a reform and not just an institutional adequacy. In that context, it got necessary to apprehending the institutional and social actors' falacy as a way to prove or not the presented hypothesis. Among the first staff, we have the mayor's direct leaders and advisors' perception that express the politcal administrative aspects of the reform and, in the second, the perception of the political view of what has changed concerning the management of the social politics

Licenciamento ambiental em postos de revenda de combustíveis à luz dos princípios constitucionais de defesas do meio ambiente: o caso do município de Natal/RN

This study approaches the question of the administrative procedure of the environmental licensing of ranks of fuel resale, taking as basis a study case of the reality of the City of Natal/RN (Brazil). For in such a way, it was done a retrospect on the evolution of the system of road transport in Brazil, having started to briefly analyze the urbanization process that if after accented in the capitals of the Brazilian States the decade of 1950, relating these subjects with the growth of the sector of fuel resale. After that, it was transferred boarding of the defense of the national environment to the light of ambient principles constitutional. In the sequence, a boarding on the ambient guardianship in the Federal Constitution of 1988 was made, treating basically specifies and on the national urban politics and the national politics of the environment, with its instruments. In the sequence, it was transferred the analysis of the abilities and attributions of the National Advice of the Environment (CONAMA) and its Resolutions, for then only enter in the most important part of this work: an analysis of the environmental licensing of ranks of fuel resale, in the reality of the City of Natal/RN. Before this specific boarding, it was proceeded specifically a survey and communication from the applicable norms to such establishments (Resolutions of the CONAMA and norms of the ABNT), for after that carrying through an geo-ambient characterization of the City of Natal/RN. Finally, a reflection was made on the possibility of magnifying of the state activity, in terms of guarantees for the responsible members for the environmental policy and of administrative efficiency, through the idea of the ambient regulation. For the accomplishment of this study, it was proceeded research in diverse sources such as books, magazines, sites of the Internet, periodicals, thesis and dissertations, among others material, beyond visits the agencies that direct or indirectly act with the ambient defense and as fuel resale, such as Secretariat of Environment and Urbanism of the City of Natal (SEMURB), Institute of Economic Development and Environment of RN (IDEMA), Brazilian Institute of the Environment and the Natural resources You renewed, Executive Management of RN (IBAMA/RN), Public prosecutor's office of the Environment of Natal (Public prosecution service of the RN), National Agency of Oil (ANP) and Union of the Retailing of Derivatives of Oil of the RN, among others. To the end, satiated regulation is observed that although on the substance of the ambient licensing in ranks of fuel resale, also with federal, state and municipal norms, the municipal Public Power is very far from the fulfilment of its institutional functions, in the question environmental policy of these establishments, a time that few are the permitted ranks of resale in the city of Natal/RN

A Constitucionalidade do decreto de licitações da Petrobrás à luz dos princípios da legalidade e da eficiência

PETROBRAS, a Brazilian oil company, follows principles of public administration and from the Constitutional Amendment 9/95 in Brazil began to compete with other companies with the flexibility of the oil monopoly. In this new model started to use the simplified procedure for bidding so that could compete on equal terms. The ordinance that adopted a simplified procedure for bidding has been the subject of some criticism and lawsuits especially under the Court of Audit and the Supreme Court in Brazil. The analysis of their constitutionality, and the possibility of their use by other group companies is the theme of this work, and for this purpose, permeates through the notions of judicial review in the Brazilian law on the stage of law and economics analysis of the norm, and the principles applicable to PETROBRAS and the devices most frequently asked about the implementation of 2745/98 Decree. For this, the basic issue that should be investigated further is the regulatory power of the Federal Executive and the delegation of powers within the legislature and its conformation to the constitutional regency

Efetividade dos direitos trabalhistas e os princípios constitucionais concretizadores da proteção laboral

The Brazilian Constitution aims to regularize the broadest possible the fundamental grounded in the value and supreme principle of human dignity, supporting a Democratic State of Law, to essentially give basic rights to all for a dignified existence. As the result of a historical development, fundamental rights incorporated by legal order represents a real reaction against acts that ignored the dignity of each person in one of these scenarios, especially inserted into the labor relationship, the principle of protection comes to balance and compose such relationship between employers and workers, raising this principle as axiological essence of this subject, based especially on the protection and guarantee of fundamental rights of the worker. For this study, was developed a literature research using books, legislation, legal websites and articles related to the subject, in order to analyze the principle of protection insert in the legal order, properly authoritative on the principle of equality, the social value of the work of human dignity to confer protection to the most vulnerable and admittedly weak of the labor relationship in order to serve the specific regulations legal practical tools and effective protection, against the employer hierarchical power and steering that can not change into abuses and attacks on the fundamental rights of the worker. In conclusion, is not enough, recognizing the vulnerability of the worker, it is necessary to carry out protective legal instruments in line with the the human dignity, consectário logical fundamental rights of workers, to be held in a proportional manner and sometimes flexible, depending on the case. Protection has a beginning and end to ensure that the human dignity that must presuppose a working relationship achieved by orderly and normative power of constitutional norms, with the aim of designing that labor is not an end in itself, but a means to the achievement of the economic advancement by promoting social development and providing necessary support for the increasingly marked impairment of fundamental rights of the worker

Gestão escolar e alfabetização de crianças na escola pública

Dans le scénario actuel marqué par l'insuccès de l'école publique en alphabétiser les enfants, l'objectif de cet étude est d'analyser, dans le cadre d'une école publique (dont les enfants, d'après les numéros officiels, deviennent lettrés au cours des trois premières années), des actions de gestion scolaire qui favorisent le processus d'alphabétisation. Pour cela nous suivons les principes de la méthode qualitative et adoptons l‟études de cas. Le terrain empirique est une école publique de la ville de Parnamirim (RN) et les sujets sont sa directrice, la vice-directrice, trois enseignantes des trois premières années de l'enseignement fondamental, deux coordinatrices pédagogiques, deux parents et six enfants. Pour la construction des données nous adoptons le questionnaire, l'analyse documentaire, des entretiens semi-dirigés et l'observation non-participante. Les fondements théoriques qui servirent de jalon à nos interprétations se retrouvent dans les conceptions actuelles de gestion éducationnelle et d'alphabétisation, ainsi que sur le processus d'apprentissage et de développement et pratique éducative. Dans cette étude, le concept de gestion est pris comme manière de dépasser la perspective bornée, bureaucratique, comme condition fondamentale de la qualité d'enseignement et de transformation de la propre identité des écoles, des systèmes d'enseignement et de l'éducation brésilienne; un concept déposé sur (et à partir de ) la mobilisation dynamique des sujets humains organisés collectivement. L'alphabétisation d'enfants est comprise en tant qu'enseignement-apprentissage du langage écrit dans une processus qui entoure deux dimensions indissociables: l'appropriation du système d'écriture alphabétique et le développement d'habilités/pratiques textuelles, dont les spécificités de développement impliquent systématisation et internationalité, caractéristiques de l'école en tant qu'institution éducative. A travers l'analyse des données fondé en quelques principes de l'analyse de contenu nous constatâmes que la gestion de l'école objet de la recherche, bien que marquée par des contradictions, développe des actions qui exercent un rôle fondamental dans les processus et résultats de l'apprentissage de l'écriture par les enfants. Ayant identifié les actions, nous construisîmes les catégories suivantes: 1) Actions relatives à l'organisation de l'école comme institution; 2) Actions relatives à organisation du processus enseignement-apprentissage; et sous-catégories: 1.1 Création et manutention d'infra-structure adéquate; 1.2 Promotion du travail collectif et autonome des professionnels; 1.3 Construction/formation permanente de l'équipe de professeurs; 1.4 Participation des parents dans la dynamique de l'école; 2.1 Disponibilité de ressources pour l'apprentissage; 2.2 Systématisation de la planification du processus enseignement-apprentissage e 2.2.1 Systématisation de l'évaluation de l'apprentissage. La catégorisation construite, bien que sa réflexion, signale que les actions qui favorisent l'alphabétisation des enfants s'approchent des conceptions d'une éducation de qualité sociale et de la démocratisation de l'éducation, bien que la propre institution de la gestion de l'école ne soit, pas encore, démocratisée. Notre étude réaffirme que la gestion de l'école, comme tout pratique humaine et sociale, a un caractère essentiellement contradictoire, inachevé et lacunaire, mais qui, jusqu'aux limites des contradiction, l'on trouve des possibilités, mises en évidence dans les actions de la gestion intimement articulées avec le succès de l'apprentissage et qui, par conséquent, peuvent construire une référence pour la réflexion sur les pratiques de gestion de l'école engagées engagée avec l'apprentissage et avec l'alphabétisation des enfants

O Programa Pró-Letramento e a formação de alfabetizadores: repercussões nas concepções e práticas de professores cursistas

This paper intents to investigate the repercussions of the Pró-Letramento - Alphabetization and Language Course Program in the practices and conceptions of alphabetization of learning teachers, according to their own perspectives. The program, part of the National Formation Network of the Education Ministry, in partnership with public universities since 2006, is destined to aid the formation of teachers acting in the first three years of public basic education, with the goal of qualifying them to work with alphabetization and improve quality of learning processes and results. This investigation adopted the qualitative research paradigm as well as the Case Study methodology, being our empirical field a Belém do Brejo do Cruz/PB public school. The subjects are five Program graduation female teachers, including the tutor-trainer and four graduated teachers that already teach in the first three years of basic education. The data, gathered with documental analysis, individual and collective semi-structured interview, and non-participant observation, were analyzed according with Speech Analysis principals. Based on those principals, we intersected teachers enunciations, observation sessions registries and the Program s propositions and built interpretations based on theorization taken as fundaments of the investigation, among which we highlight: studies on a criticalreflexive perspective of a teacher s formation; continued formation as a permanent development process; the principals of historical-cultural approach on alphabetization processes and development with the centrality of language; alphabetization in a interactionist approach. The analysis focused on the Program s repercussions: 1) in the teachers conceptions about: 1.1) learning; 1.2) Alphabetization and literacy; and in the practices and conceptions related to: 1.3) alphabetization in a literacy perspective and 1.4) appropriation of the writing system. The corpus analysis evidenced relations of continuity and discontinuity, approach and distancing between the teachers conceptions and the Program s propositions, as well as conceptions/significance of their speeches and related or observed practices. Observing teachers elaborations evidences the repercussion of the Program s formation, whilst also showing gaps and mismatches in their appropriation process in concepts/assumptions as well as teaching propositions. These mismatches involve interaction relationships between teachers and students, with their possibilities and limitations surrounding the Program s knowledge objects complexity, also linking to the social, economical, political, and cultural conditions that involve both the implementation of the Program in each context and the conditions in which alphabetization in public schools are developed, demanding permanent and accompanied formation processes, investments to improve work conditions and valuing teaching