O papel dos valores e crenças africanas no tempo de trabalho circular, nas estratégias, na negociação das diferenças entre operários e dirigentes no corredor de Maputo

A categoria tempo circular ou indiferenciado mostra que o trabalho formal é vivido de acordo com a subjetividade dos seus participantes, com uma multiplicidade de significados e de configurações sempre variáveis. Neste estudo, identificou-se a existência de uma relação entre o tempo circular e as estratégias elaboradas pelos trabalhadores na conquista de uma maior autonomia nos espaços de trabalho. Além disso, observou-se a convivência entre trabalhadores, empresários e dirigentes governamentais e sindicais presentes num projeto de modernização no sul de Moçambique, denominado Corredor de Desenvolvimento de Maputo e constatou-se o modo como é realizada a negociação das diferenças. Realizou-se um levantamento das principais estratégias levadas a cabo por empresários nacionais, estrangeiros, governo e sindicatos na gestão da força de trabalho, formação, qualificação e o uso do tempo nos espaços de trabalho, bem como as perspectivas de desenvolvimento humano trazido por este projeto na região de Maputo. Por enquanto, ainda não foi possível detectar um interesse real dos grupos empresariais e governamentais em delinear caminhos tendentes a encontrar equilíbrios possíveis entre a modernização e a tradição, que sejam compatíveis com a satisfação das necessidades, valores e crenças e o respeito ao imaginário dos grupos envolvidos na construção da modernização tecnológica do país. Parecem evidentes estratégias em que a responsabilidade social está ausente e a estratégia de abertura das Zonas Francas Industriais ao investimento externo carece de uma verdadeira negociação entre “parceiros” em que sejam distribuídas de forma equitativa as vantagens e desvantagens inerentes aos projetos de industrialização a serem implantados localmente. Os testemunhos obtidos junto dos protagonistas moçambicanos expressaram uma grande frustração e desencantamento quanto a resultados que possam vir a ser promissores para as populações, trabalhadores e empresários nacionais do projeto em curso. Portanto, este projeto mostra ser um processo exógeno introduzido à revelia de seus principais protagonistas nesta fase de implantação em território moçambicano e onde os aspectos culturais foram desrespeitados, além de serem usados como estratégia para tirar vantagens adicionais.

Análise experimental do sistema "vórtice ferradura" no escoamento ao redor de um cilindro circular

Este trabalho apresenta o estudo de um sistema hidrodinâmico encontrada em muitas situações dentro da mecânica dos fluidos: o Vórtice Ferradura. Esta estrutura possui características bastante complexas e seu comportamento ainda é pouco compreendido e explicado. Assim, o escoamento ao redor do cilindro circular, em leito fixo, foi investigado experimentalmente, com o propósito de tentar caracterizar o comportamento hidrodinâmico do Vórtice Ferradura através da visualização de escoamento e medições de pressão. Para o trabalho, um cilindro foi montado. As visualizações do Vórtice foram feitas através de uma janela de visualização na seção de testes do canal. A filmagem foi feita através de uma câmera de vídeo VHS, de uso doméstico, e injeção de corante. As medições de pressão foram feitas através do emprego de transdutores de pressão, e divididas em dois grupos: (i) medições de pressão feitas no leito do canal, na linha de simetria, na região de escoamento próxima ao Vórtice; (ii) medições de pressão do escoamento na superfície do cilindro. As imagens, assim como os dados de transdutor, foram transportados para o meio digital para posterior manipulação e análise. Os resultados confirmam algumas descrições fornecidas pela literatura, bem como, também levantam algumas considerações sobre o assunto: as imagens permitiram a visualização das etapas de formação do Vórtice, descrever modificações em seu diâmetro ao longo dos ensaios, reconhecer a variabilidade espacial de sua posição e detectar a presença de um vórtice secundário. Os dados de transdutor descreveram o campo de pressões no leito do canal, modificado pela presença do cilindro e, ao redor da superfície do mesmo, bem como, o comportamento das flutuações de pressão, correlações, autocorrelações e espectros das flutuações de pressão dos transdutores, para estas situações.

Memória de um tempo circular no território de Carlos Fuentes

Ao contrário da concepção linear do pensamento ocidental, o tempo mexicano, situado na tradição pré-hispânica, indica uma multiplicidade de tempos, possibilitando que variadas e distantes épocas sejam realidades presentes. Nesse enfoque, diferentes tempos da história mexicana incorporam a narrativa de Carlos Fuentes, onde é comum passado, presente e futuro estarem imbricados em circularidades que resgatam com a imaginação e a linguagem uma memória encoberta pelo discurso totalizador. Na sua obra, Carlos Fuentes percorre mitos, tempos e espaços através de uma escritura que traduz uma cultura mestiça construída por vertentes americanas e européias. No entrelaçamento da pluralidade dos mundos, descobre os acontecimentos do passado, introduzindo significações aos silêncios relegados à margem da história. Através das análises de “Las dos orillas” – conto do livro El naranjo; do romance La muerte de Artemio Cruz e de personagens que transitam nos contos de La frontera de cristal, são investigados três momentos da história mexicana: Conquista espanhola, Revolução mexicana e migrações da atualidade na fronteira. Desse modo, são exploradas possibilidades históricas disseminadas na produção de Carlos Fuentes

Ampliação de movimentos na dança circular com pessoas com deficiência visual

This paper aims at studying how circular dance can afford to sight-disabled peoples movement and how they can learn to cope with the deep movement of relation, consciousness, appropriation and communion with the world. Inside circular dance, a cosmic metaphor, is inscribed the movement of the world, which tells and changes amorously the human history. In the works of Paulo Freire and Maurice Merleau-Ponty one can find the necessary support to discuss, as long as possible, movement and existence. Research-action is used as a methodological approach whose empirical center is placed on the Institute of Education and Rehabilitation of Blind, in Natal, which shelters eight sightdisabled adults. The research s data reveal that the practice of circular dance concurs to enlarge the movement of the research s subjects, to develop a more accurate perception of their selves and of their own capacities, as well as improve the relations Me/Others, Me/World, which require a context of differences. The study has revealed that the practice of dance develops a better perception of the limits and surpasses as a human condition and, in consequence, the discovery of one s own body and the other s body as a resource of lessons and representations of the self and of the world. It lets out the development of a new way of thinking and coping with discrimination surrounding the disabled persons. In movement, in circular dance, the barrier between sight disablement and vision loses force.

Desenvolvimento de antenas de microfita e antenas DRA Broadband

The search for ever smaller device and without loss of performance has been increasingly investigated by researchers involving applied electromagnetics. Antennas using ceramics materials with a high dielectric constant, whether acting as a substract element of patch radiating or as the radiant element are in evidence in current research, that due to the numerous advantages offered, such as: low profile, ability to reduce the its dimensions when compared to other devices, high efficiency of ratiation, suitability the microwave range and/or millimeter wave, low temperature coefficient and low cost. The reason for this high efficiency is that the dielectric losses of ceramics are very low when compared to commercially materials sold used in printed circuit boards, such as fiberglass and phenolite. These characteristics make ceramic devices suitable for operation in the microwave band. Combining the design of patch antennas and/or dielectric resonator antenna (DRA) to certain materials and the method of synthesis of these powders in the manufacture of devices, it s possible choose a material with a dielectric constant appropriate for the design of an antenna with the desired size. The main aim of this work is the design of patch antennas and DRA antennas on synthesis of ceramic powders (synthesis by combustion and polymeric precursors - Pe- chini method) nanostructured with applications in the microwave band. The conventional method of mix oxides was also used to obtain nanometric powders for the preparation of tablets and dielectric resonators. The devices manufactured and studied on high dielectric constant materials make them good candidates to have their small size compared to other devices operating at the same frequency band. The structures analyzed are excited by three different techniques: i) microstrip line, ii) aperture coupling and iii) inductive coupling. The efficiency of these techniques have been investigated experimentally and compared with simulations by Ansoft HFSS, used in the accurate analysis of the electromagnetic behavior of antennas over the finite element method (FEM). In this thesis a literature study on the theory of microstrip antennas and DRA antenna is performed. The same study is performed about the materials and methods of synthesis of ceramic powders, which are used in the manufacture of tablets and dielectric cylinders that make up the devices investigated. The dielectric media which were used to support the analysis of the DRA and/or patch antennas are analyzed using accurate simulations using the finite difference time domain (FDTD) based on the relative electrical permittivity (er) and loss tangent of these means (tand). This work also presents a study on artificial neural networks, showing the network architecture used and their characteristics, as well as the training algorithms that were used in training and modeling some parameters associated with the devices investigated

Análise dos Modos Ressonantes em Antenas de Microfita sobre Substratos Iso/Anisotrópicos por Técnicas da Ressonância Transversa

Neste trabalho, são utilizadas a Técnica da Ressonância Transversa (TRT) e a Técnica da Ressonância Transversa Modificada (MTRT), para a determinação das freqüências dos modos ressonantes de antenas de microfita com patch quadrado, retangular e circular e com substratos isotrópicos e anisotrópicos. Para isso, é proposto um modelo da cavidade equivalente, onde a antena tipo patch retangular é representada como sendo a superposição de duas linhas infinitas em microfita, uma de largura W, representando a dimensão que expressa a largura do patch, e a outra com largura L, representando a dimensão que expressa o comprimento do patch. A avaliação da eficiência e aplicabilidade dos métodos citados é realizada comparando-se com resultados experimentais e obtidos através de outras técnicas. Três situações serão verificadas: estruturas com substrato infinito, estrutura com substrato tipo pedestal e estruturas com substrato truncado além dos limites da fita metálica. Os resultados obtidos demonstram que as técnicas de análise de onda completa utilizadas neste trabalho, por um formalismo matemático mais rigoroso, são eficientes e precisas tanto na aplicação em estruturas com substrato isotrópico como nas que possuem substrato anisotrópico. Inicialmente são consideradas apenas as estruturas com substratos isotrópicos, com diferentes constantes dielétricas, e é avaliada a influência da largura do substrato sobre as freqüências dos modos ressonantes das antenas. Posteriormente, a análise do truncamento do dielétrico é realizada para estruturas com substrato anisotrópico. Em todos os casos, os resultados experimentais, obtidos a partir da construção de protótipos, são confrontados com os obtidos a partir de simulação, utilizando as técnicas TRT e MTRT. No final, as técnicas descritas são utilizadas para antenas tipo patch circular, sendo utilizada uma técnica de equivalência para transformar a antena circular em outra quadrada ou retangular equivalente, dependendo do modo que se queira encontrar. Os resultados obtidos são então analisados, observando-se uma boa concordância e indicando a viabilidade do método. Após isso, são apresentadas as conclusões e sugeridos alguns temas para a continuidade deste trabalho

Antenas de microfita com patch quase-fractal para aplicações em Redes WPAN/WLAN

The microstrip antennas are in constant evidence in current researches due to several advantages that it presents. Fractal geometry coupled with good performance and convenience of the planar structures are an excellent combination for design and analysis of structures with ever smaller features and multi-resonant and broadband. This geometry has been applied in such patch microstrip antennas to reduce its size and highlight its multi-band behavior. Compared with the conventional microstrip antennas, the quasifractal patch antennas have lower frequencies of resonance, enabling the manufacture of more compact antennas. The aim of this work is the design of quasi-fractal patch antennas through the use of Koch and Minkowski fractal curves applied to radiating and nonradiating antenna s edges of conventional rectangular patch fed by microstrip inset-fed line, initially designed for the frequency of 2.45 GHz. The inset-fed technique is investigated for the impedance matching of fractal antennas, which are fed through lines of microstrip. The efficiency of this technique is investigated experimentally and compared with simulations carried out by commercial software Ansoft Designer used for precise analysis of the electromagnetic behavior of antennas by the method of moments and the neural model proposed. In this dissertation a study of literature on theory of microstrip antennas is done, the same study is performed on the fractal geometry, giving more emphasis to its various forms, techniques for generation of fractals and its applicability. This work also presents a study on artificial neural networks, showing the types/architecture of networks used and their characteristics as well as the training algorithms that were used for their implementation. The equations of settings of the parameters for networks used in this study were derived from the gradient method. It will also be carried out research with emphasis on miniaturization of the proposed new structures, showing how an antenna designed with contours fractals is capable of a miniaturized antenna conventional rectangular patch. The study also consists of a modeling through artificial neural networks of the various parameters of the electromagnetic near-fractal antennas. The presented results demonstrate the excellent capacity of modeling techniques for neural microstrip antennas and all algorithms used in this work in achieving the proposed models were implemented in commercial software simulation of Matlab 7. In order to validate the results, several prototypes of antennas were built, measured on a vector network analyzer and simulated in software for comparison

Arranjo de antenas de microfita com substrato anisotrópico com patch supercondutor e aplicações em nanotecnologia

The main objective in this work is the analysis of resonance frequency microstrip structures with glass fiber and electromagnetic band gap (EBG/PBG) substrate and analysis of microstrip antennas with rectangular patch of superconductor of high critical temperature (HTS). In this work was used the superconductors YBCO (critical temperature of 90K), SnBaCaCuOy (critical temperature of 160K), and Sn5InCa2Ba4Cu10Oy (critical temperature of 212K) with results in Gigahertz and Terahertz. Was used microstrip antennas arrays planar and linear phase and linear phase planar with patch with superconductor. It presents a study of the major theories that explain superconductivity. In phase arrays were obtained the factors arrays for such configurations, and the criteria of phase and spacing between the elements compound in the array, which were examined in order to get a main lobe with high directivity and high gain. In the analysis we used the method of Transverse Transmission Line (TTL) used in domain of the Fourier Transform (FTD). The LTT is a full wave method, which obtains the electromagnetic field in terms of the components transverse of the structure. The addition of superconductive patch is made using the boundary condition resistive complex. Results are obtained resonance frequency as a function of the parameters of the antenna, radiation patterns of the E and H Planes, for the phase antenna arrays in linear and planar configurations, for different values of the phase and the spacing between elements

Um estudo de metamaterial em antenas de microfita

Metamaterials have attracted a great attention in recent years mostly due to their electromagnetic properties not found in nature. Since metamaterials began to be synthesized by the insertion of artificially manufactured inclusions in a medium specified host , it provides the researcher a broad collection of independent parameters such as the electromagnetic properties of the material host. In this work was presents an investigation of the unique properties of Split Ring Resonators and compounds metamaterials was performed. We presents a theoretical and numerical analysis , using the full-wave formalism by applying the Transverse Transmission Line - LTT method for the radiation characteristics of a rectangular microstrip antenna using metamaterial substrate, as is successfully demonstrated the practical use of these structures in antennas. We experimentally confirmed that composite metamaterial can improved the performance of the structures considered in this thesis

Antenas e superfícies seletivas de freqüência reconfiguráveis para sistemas de comunicação sem fio

This work aims to present how the reconfigurable microstrip antennas and frequency selective surfaces can be used to operate at communication systems that require changing their operation frequency according to system requirements or environmental conditions. The main purpose is to present a reconfigurable circular microstrip antenna using a parasitic ring and a reconfigurable dipole frequency selective surface. Thereupon there are shown fundamental topics like microstrip antennas, PIN diodes and the fundamental theory of reconfigurable antennas and frequency selective surfaces. There are shown the simulations and measurements of the fabricated prototypes and it is done an analysis of some parameters like the bandwidth and radiation pattern, for the antennas, and the transmission characteristics, for the frequency selective surface. Copper strips were used in place of the diodes for proof of the reconfigurability concept

Aplicações de arranjos de antenas de microfita com patch supercondutor

This work has as main objective the study of arrays of microstrip antennas with superconductor rectangular patch. The phases and the radiation patterns are analyzed. A study of the main theories is presented that explain the microscopic and macroscopic phenomena of superconductivity. The BCS, London equations and the Two Fluid Model, are theories used in the applications of superconductors, at the microstrip antennas and antennas arrays. Phase Arrangements will be analyzed in linear and planar configurations. The arrangement factors of these configurations are obtained, and the phase criteria and the spacing between the elements, are examined in order to minimize losses in the superconductor, compared with normal conductors. The new rectangular patch antenna, consist of a superconducting material, with the critical temperature of 233 K, whose formula is Tl5Ba4Ca2Cu9Oy, is analyzed by the method of the Transverse nTransmission Line (TTL), developed by H. C. C. Fernandes, applied in the Fourier Transform Domain (FTD). The TTL is a full-wave method, which has committed to obtaining the electromagnetic fields in terms of the transverse components of the structure. The inclusion of superconducting patch is made using the complex resistive boundary condition, using the impedance of the superconductor in the Dyadic Green function, in the structure. Results are obtained from the resonance frequency depending on the parameters of the antenna using superconducting material, radiation patterns in E-Plane and H -Plane, the phased antennas array in linear and planar configurations, for different values of phase angles and different spacing between the elements

Antenas de microfita com patch supercondutor a 212 K

This work has as main objective to study the application of microstrip antennas with patch and use of superconducting arrays of planar and linear phase. Was presented a study of the main theories that explain clearly the superconductivity. The BCS theory, Equations of London and the Two Fluid Model are theories that supported the implementation of the superconducting microstrip antennas. Arrangements phase was analyzed in linear and planar configuration of its antennas are reported factors such arrays to settings and criteria of phase and the spacing between the elements that make the arrayst was reviewed in order to minimize losses due to secondary lobes. The antenna used has a rectangular patch Sn5InCa2Ba4Cu10Oy the superconducting material was analyzed by the method of Transverse Transmission Line (TTL) applied in the field of Fourier transform (FTD). The TTL is a full-wave method, which has committed to obtaining the electromagnetic fields in terms of cross-cutting components of the structure. The inclusion of superconducting patch is made using the boundary condition, complex resistive. Are obtained when the resonant frequency depending on the parameters of the antenna, radiation pattern of E-Plan and H-Plan for the M-phase arrangements of antennas in the linear and planar configurations for different values of phase and spacing between the elements.

Antenas de microfita com patch em anel e múltiplas camadas dielétricas anisotrópicas uniaxiais

This work presents an analysis of the annular ring microstrip antennas printed on uniaxial anisotropic substrates and with superstrate.The analysis uses the full-wave formulation by means of the Hertz vector potentials method, in the Hankel transform domain. The definition of the Hertz vector potentials and the application of the appropriate boundary conditions to the structure allow determining the dyadic Green functions, relating the current densities in the conducting patch to the transforms of the tangential electric field components. Galerkin s method is then used to obtain the matrix equation whose nontrivial solution gives the complex resonant frequency of the antenna. From the modeling, it is possible to obtain results for the resonant frequency, bandwidth and quality factor, as a function of several parameters of the antenna, for different configurations. We have considered annular ring microstrip antennas on a single dielectric layer, antennas with two anisotropic dielectric layers, and annular ring microstrip antennas on suspended substrates. Numerical results for the resonant frequency of the these structures printed on isotropic substrates are also presented and compared with those published by other authors, showing a good agreement

Análise de antenas de microfita com patches circulares sobre substratos anisotrópicos usando o método dos potenciais de Hertz

This work consists on the theoretical and numerical analysis of some properties of circular microstrip patch antennas on isotropic and uniaxial anisotropic substrates. For this purpose, a full wave analysis is performed, using Hertz Vector Potentials method in the Hankel Transform domain. In the numerical analysis, the moment method is also used in order to determine some characteristics of the antenna, such as: resonant frequency and radiation pattern. The definition of Hertz potentials in the Hankel domain is used in association with Maxwell´s equations and the boundary conditions of the structures to obtain the Green´s functions, relating the components of the current density on the patch and the tangential electric field components. Then, the Galerkin method is used to generate a matrix equation whose nontrivial solution is the complex resonant frequency of the structure. In the analysis, a microstrip antenna with only one isotropic dielectric layer is initially considered. For this structure, the effect of using superconductor patches is also analyzed. An analysis of a circular microstrip antenna on an uniaxial anisotropic dielectric layer is performed, using the Hertz vector potentials oriented along the optical axis of the material, that is perpendicular to the microstrip ground plane. Afterwards, the circular microstrip antenna using two uniaxial anisotropic dielectric layers is investigated, considering the particular case in which the inferior layer is filled by air. In this study, numerical results for resonant frequency and radiation pattern for circular microstrip antennas on isotropic and uniaxial anisotropic substrates are presented and compared with measured and calculated results found in the literature

Aplicação do método LTT às estruturas retangulares e triangulares em multicamadas e empilhadas em substratos PBG para comunicações móveis

Recently the planar antennas have been studied due to their characteristics as well as the advantages that they offers when compared with another types of antennas. In the mobile communications area, the need for this kind of antennas have became each time bigger due to the intense increase of the mobile communications that needs of antennas which operate in multifrequency and wide bandwidth. The microstrip antennas presents narrow bandwidth due the loss in the dielectric generated by radiation. Another limitation is the radiation pattern degradation due the generation of surface waves in the substrate. In this work some used techniques to minimize the disadvantages (previously mentioned) of the use of microstrip antennas are presented, those are: substrates with PBG material - Photonic Bandgap, multilayer antennas and with stacked patches. The developed analysis in this work used the TTL - Transverse Transmission Line method in the domain of Fourier transform, that uses a component of propagation in the y direction (transverse to the direction real of propagation z), treating the general equations of electric and magnetic field as functions of y and y . This work has as objective the application of the TTL method to microstrip structures with single and multilayers of rectangular and triangular patches, to obtaining the resonance frequency and radiation pattern of each structure. This method is applied for the treatment of the fields in stacked structures. The Homogenization theory will be applied to obtaining the effective permittivity for s and p polarizations of the substrate composed of PBG material. Numerical results for the triangular and rectangular antennas with single layer, multilayers resonators with triangular and rectangular patches are presented (in photonic and isotropic substrates). Conclusions and suggestions for continuity of this work are presented