Análise da resiliência sócio-ecológica em unidades de conservação de uso sustentável: subsídios para o manejo da pesca artesanal no Brasil

O uso da biodiversidade pelo homem leva a alterações no funcionamento dos ecossistemas, podendo ainda levar a perda de resiliência. Pode-se definir resiliência como a capacidade de um sistema absorver um distúrbio e reorganizar-se, enquanto submetido a mudanças, mantendo a mesma estrutura e funcionamento. Em um sistema social, entende-se como a capacidade dos usuários de recursos naturais de enfrentar e adaptar-se as mudanças nas regras que regem o uso e acesso a estes. Alterações na resiliência, tanto ecológica quanto social, podem ser resultantes das ações de exploração e manejo destes recursos. Assim, torna-se essencial compreender como funcionam as estratégias de manejo e sua interação com a resiliência sócio-ecológica, permitindo a auto-avaliação das ações e possíveis modificações das mesmas. Neste projeto, propõe-se comparar a resiliência sócio-ecológica de três Unidades de Conservação (UCs) de uso sustentável: Reserva de Desenvolvimento Sustentável (RDS) Ponta do Tubarão, localizada no estado do Rio Grande do Norte; e as Reservas Extrativistas do Batoque e Prainha do Canto Verde, ambas localizadas no estado do Ceará. Em cada área de estudo serão escolhidas comunidades pesqueiras, permitindo a comparação entre elas. A partir destas comunidades, alguns aspectos relacionados ao uso dos recursos serão analisados, como atividade pesqueira, dieta e modo de vida. Os dados serão coletados através de questionários semi-estruturados, contendo questões baseadas em aspectos sociais, econômicos e ecológicos. Os resultados obtidos servirão de indicadores para a resiliência ecológica (informações obtidas com base na atividade pesqueira) e social (informações obtidas com base no acompanhamento da dieta e análise do modo de vida). Apesar da similaridade ecológica entre as áreas de estudo, algumas estratégias de manejo distintas em função da categoria da UC podem apresentar diferentes resultados sobre a resiliência sócio-ecológica. Desta forma, compreender como a resiliência sócio-ecológica se comporta, dentro dos sistemas de manejo estudados, permitirá avaliar a influência destes dois tipos de UCs (RDS e RESEX) na promoção da sustentabilidade ecológica e/ou social

Crescimento econômico e restrição externa da economia brasileira: uma análise do padrão das exportações em relação ao BRIC e do Sistema de Inovação do Brasil (1980-2012)

This Master s Thesis aims to use the theoretical models of growth with restricted balance of payments, specifically Kaldor (1970) and Thirlwall (1979) models, to analyze the behavior and the pattern of specialization of Brazilian exports and imports in the last years. It is observed that, in some periods, the pattern of specialization has contributed in restricting long-term growth of the Brazilian economy. It has been hypothesized that overall this is due to lack of structural transformation policies. To achieve this goal, it analyzed the performance of Brazilian exports and imports disaggregating them according to their technological content. The basis for comparison was a group of countries to which Brazil is inserted in, the BRIC. In this regard, the work is a comparative analysis by using descriptive statistics. It is concluded that the low rate of GDP growth experienced by Brazil since the 1980s can be explained in part by the decoupling of the Brazilian National Innovation System (NIS) and the Brazilian productive structure. This would be reducing the income elasticity of exports and raising imports, causing a pattern of specialization intensive primary commodities and labor and low-skill labor

Reconfigurações industriais das regiões metropolitanas do Nordeste: uma análise a partir do emprego formal

Industrial development experienced by Brazil from the 1950s, changed the concentration of population in the country. The process of development of domestic industry, concentrated in urban areas, crowded growing portion of the population.The Southeast region during the first stage of industrialization driven by the state, with the implementation of Plan goals, captained the major industrial projects implemented in the period and became the main industrial center of the country.In the decade from 1960 to 1980 the state action was marked by numerous regional development projects, softening the industrial concentration and Brazilian investment redirected to the Northeast.The second National Development Plan implemented in the 1970s led to major investments Northeast.This period marked the widespread urban growth and institutionalization of the first metropolitan areas in Brazil.The change of this developmental process is altered with the fiscal and financial crisis of the state in the 1980s and 1990s and spending cuts aimed at national development, reorienting the economy to liberal policies of economic liberalization and reduction of activity in the economy.Industrial policy was relegated to local development plans from the 1990s to the federating units fitting the wide use of tax incentives, the "war tax" to the continued industrialization process.In this context of the national economy work seeks to analyze the industrial setting in the metropolitan areas of Fortaleza, Recife and Salvador between 1995 and 2010.Although the metropolitan areas of Fortaleza, Recife and Salvador are the main urban centers of the Northeast, responsible for the advancement of industrial development, reconfigurations occurred between 1995 and 2010 by changing the level of industrial specialization built by regional division of labor in these regions.The work will be carried out by the method of descriptive analysis of the literature review on regional and urban development.Constitute quantitative method as the secondary data analysis of formal employment from the Annual Social Information (RAIS) Ministry of Labour and Employment (MTE).Using data RAIS / MTE analyzes the industrial specialization index using the Locational Quotient (LQ).Thus, it is assumed as a parameter analysis QL> 1, when the region has become specialized in a particular sector or QL <1, when the region does not have expertise in industrial sector analyzed.The conclusion of study indicates that there was in these metropolitan areas maintained the same bias hub.Fiscal policies, the states, was not successful in diversifying the productive structure and the Northeast region itself.This result is demonstrated by the need and dependence on state investments in the region to promote development.Industrial policies of recent years have been positive to meet the objectives of employment generation, but there must be specific policies for better diversification of production, in addition to integrating the economy of the Northeast sector and regionally

Compreendendo a educação para a inclusão digital: uma análise dos sentidos atribuidos pelos monitores das escolas de inclusão digital e cidadania da EMATER-RN

According to the methodological presuppositions of the understanding interview (KAUFMAAN, 1996), the present work aims to understand the Digital Inclusion starting from the oral speeches of eight monitors of Digital Inclusion and Citizenship Schools of the Technical Assistance and Rural Extension Company EMATER, located in municipal districts that belong to six regions of the state of Rio Grande do Norte. It also had the intention to analyze it (the Digital Inclusion), while educational process and its relation with the citizenship. In its first part, an analysis of the discussions about digital inclusion was developed, and a reflection about the new technologies in current times, followed by a contextualization of the rural space and the methodological course of the study, when its guiding axis and the travelled roads were presented, where the object of study is built slowly and progressively through a theoretical elaboration that increases day by day, as of the technologies forged in the field of research and formation of the subject. The second part presents the study of the collected information, that is organized in three chapters denominated as follows: Conceptions of the local context; What does digital inclusion mean? and The monitor as an educator. The reports do evidence a peculiar dissatisfaction with the social reality where they are found, that contradicts the positive reflections and perspectives of the studied authors, once that, within the actual conjuncture, the rural space has acquired another meaning, no longer being seen as a far late place. By trying to define the digital inclusion, the monitors make an association with change, the access to knowledge, active participation in society and improvement of the life conditions. Here a mission sense stands out, related to the ideological precept, which has been managing its activities. Towards the monitor‟s relation within the classroom, the senses evidence how they are and how they have been developing their daily activities. Tensions, fears and insecurities are identified, but at the same time, a compromise. The final considerations implicate to the need of reorientations in the formative process of this professionals, detaching the importance of their activities while agents of inclusion and social transformation

As contribuições do proformação/pedagogia/UERN para a melhoria da prática pedagógica de professores

This dissertation aims at analyzing some relations established between teachers‟ formative proposal for docent knowledge and pedagogical practices in the Special Program of Professional Formation to Basic Education (Proformação in Portuguese) with the objective of investigating how teachers evaluate knowledge acquired during their course formation to identify its improvement in their pedagogical practice. This is a Pedagogical Program of the State University of Rio Grande do Norte chosen to be analyzed. The objective is to investigate how teachers, Proformação/Pedagogy course students evaluate privileged knowledge in that university formation and how the relation between this knowledge and their pedagogical practice are experienced in classroom as teachers, defining in which way knowledge constructed and reconstructed during the course contributes for an improvement of their pedagogical practices. We have interviewed fourteen Proformação/Pedagogy last-term teachers, emphasizing the analysis of their point of view as social actors related to docent university formation in service. The principles for this investigation comprehend a qualitative approach, in a case study modality, with an exploratory tendency, presented in the introductory section and along four chapters. The research is theoretically guided by Andoino (1998), Bardin (2009); Laville e Dione (1999); Bogdan and Biklen (1994), Hernandez Sampieri, Hernandez Collado and Baptista Lúcio (2006), among others. We justify this thematic choice, considering docent formation and its interface with an improvement for students‟ leaning, taking into account the strict relations between those elements. We have discussed on docent formative paradigms, based on a multireferential perspective, whose main authors that developed research in this area are: Gómez (1998), Sacristán e Gómez (1998), Tardif (2002), Altet (2001) Paquay e Wagner (2001), Garcia (1999), Baldi (2008), La Torre e Barrios (2002). We interviewed fourteen teachers, all of them in the last term of the Program. In the second chapter, we justify the choice of the subject, approaching docent formation and its relation with basic teaching. We understand that there is a strong relation between those aspects. In the third chapter, we discuss on some docent formative paradigms, among them, Gomes (1998), Sacristán and Gomez (1998), Tardig (2002), Altet (2001) Paquay and Wagner (2001), Garcia (1999), Baldi (2008), La Torre and Barrios (2002). We introduce the Pedagogical Program structure and specify which formative paradigms characterize it and identifying that one of the most prominent paradigm is a practical perspective with emphasis on reflexivity about the practice based on the premise that docent formation is be based on from learning to practice theory. We present an data analysis obtained from thematic categorization extracted subjects‟ discourses and, at the end, we discuss on evaluation of the teachers involved in the research related to the course contributions to provide an improvement for pedagogical practices developed by them inside their classrooms. We consider, thus, that teachers evaluate the Program as a guideline for (re)construction of diversified knowledge, which, in turn, provides the development of abilities to analyze classroom situations based on pedagogical theories and to develop investigative practice based on everyday experience. The results point out that some implications are relevant, among them: the thematic-choice, discussed previously, needs other kinds of investigations. The relation between theory and practice proposed in formation programs requires more systematic studies considering others aspects that characterize teaching process, and mainly, to provide investigative proposals of and about such practices

Gêneros do discurso e escrita: o que as coleções didáticas de português (des)prestigiam no ensino da produção textual?

Through the examination of official indicators, it can be observed that writing is pointed out as one of the main problems concerning formal basic education. However, this teaching-learning object is one of the central objectives at school, having an essential role in different curricular components as well as in the interaction demands required by society. Such paradox indicates, therefore, the relevance of investigations which analyze the intrinsic elements of child development as written text producer. Hence, the main purpose of this research consists of analyzing the treatment given to the types of discourse and the teaching situations in which the written text are produced, concerning Portuguese language didactic material collections approved by Programa Nacional do Livro Didático (PNLD 2010) the Brazilian program of didactic book and worked at elementary school. Such materials correspond to the collections adopted in municipal education system schools from Natal, RN which were below the official education indicator IDEB 2009. Thus, the questions that guide this work are: 1. During writing production lessons, is the diversity of types of discourse effectively worked on didactic collections? 2. Which are the types of discourse and the social spheres prioritized when teaching writing production? 3. How is the situation addressed in the production of the written text should be produced? For this research, we retook the authors Bakhtin, Bunzen, Faraco, Freire, Rodrigues, Rojo, Schneuwly e Dolz and we made a list of all types of discourse and spheres contemplated in the propositions of the writing production in didactical books, concerning the eight collections which compounds the first moment of analysis. Then, we verified how the situation of production is oriented by examining two didactic collections if and how they express the elements referring to the social-historical, functional and linguistic-discursive context of the text to be produced. The data obtained indicate: lack of diversification of types of discourse in the collection that compounds the Aggregate Sample of the research; the conception of a diversity based on the didactic of visiting; the recognition of all canonical and hegemonic types of text as one of the privileged objects of study; the centralization on the standard variety of the language and the devaluation of the representative types of cultural diversity; the shortage of productions which retrace to written language related to different technologies of communication and information; and the little emphasis on the types of discourse related to public language practices. As for the situations of production, it is observed the predominance of the school as a producer of dialogic relationships, whose propositions present, for example, text addressees, enunciative positions, support and contexts of restricted circulation, especially at school. Two divergent situations are observed among the collections: the lack of a work in which the situation of production is under the perspective of the types of discourse as object of teaching-learning; the concept of the types of discourse as object of reflection, presenting a differentiated didactic orientation towards the situation of production. This research contributes, therefore, with a mapping of the existence and the treatment of the types of discourse on propositions of writing production in didactic books; with the critical analysis of the approach of written activities, considering the elements of the historical-social, functional and linguistic-discursive context; thus, through teaching, research and public policies, use and selection of didactic material for the area

Representações sociais do comportamento agressivo do homem sob a ótica da mulher em situação de violência

We aim to understand the social representations of man's aggressive behavior from the perspective of women in situations of domestic violence. This is a descriptive, exploratory and representational study, whose methodological approach falls into the qualitative category. We chose as a scenario for research, by the Reference Center for Citizen Women (CRMC), Natal / RN. The criteria for selection of participants were women who lived/live in situations of domestic violence, with affective or relationship bonding with the assailant, in psychological and emotional positions appropriated to the reality; that are being protected or assisted by the service listed above; whose aggressor is male. We adopted as data collection instruments: questionnaire, Drawing-Story (DE) and a field diary. For analysis of textual data, we decided to use the ALCESTE software conjugated to editing analyze and initial reading. Were investigated 20 women victims of domestic violence, whose author of the attacks was the husband/partner. We identified, from the respondents, that 70% (n = 14) of men with aggressive behavior also had a family history of violence and fragile family relationships. About the physical and emotional condition of the assailant at the time of violence, 50% (n = 10) of these men, regardless the use of alcohol, had often quarrelsome and/or nervous behavior, impatient and unpredictable humor facing a setback, worry or annoyance. Regarding the nature of violence, we observed that women were victims of all types of violence, however, the psychological prevailed in 100% of cases. The corpus "Men" has three classes, whose focuses are, respectively: resignation, denounce and violence/aggression, being possible categorizing them as well: Category 1: The imprisonment of women; Category 2: Violence and its meanings; Category 3: Breaking the violent cycle. We show that the social representations of man s aggressive behavior, from the women in situations of violence, are anchored in the social roles of men in family and society, becoming a dominant model of masculinity. It is aimed, on one hand, from the reproduction of what is already known and/or experienced by male aggressors in the family, as repetitions of behavior. And on the other, present themselves as a state of illness, addiction or psychopathy

Atuação do enfermeiro no acompanhamento do crescimento e desenvolvimento da criança

The nurses assistance in monitoring the growth and development of children has been characterized mostly a service based on the biological dimension of illness, when in reality, the actions should be combined in the reorientation of care model of the Family Health Strategy. Thus, the research aimed to examine the role of nurses in the growth and development of children. This is an exploratory and descriptive, qualitative approach. The project was approved by the Ethics Committee of the Universidade Federal do Rio Grande do Norte under Opinion No. 191/2012. Data collection was developed in the Health Units from the city of Natal, RN, Brazil. Survey participants were nurses who worked in the Family Health Strategy for at least two years and who performed the monitoring of child growth and development in the health unit selected. Data were collected through an in-depth interview, and seized material from speeches was treated as categorical thematic analysis proposed by Bardin. This process revealed three themes, which were analyzed in the light of Relief Models and Process Work in Health and Nursing and discussed based on the findings literary. The results elucidated that nurses consider their performance satisfactory as it has favored the accession of mothers of children under one year nursing visits, contributing to the reduction of morbidity and mortality due to prevalent diseases, as well as the establishment of a connection between the professionals and mothers. It was shown that despite having a promotion and prevention with the use of lightweight technologies, the nurses also emphasized the care of mothers in complaints and signs and symptoms of children, followed by referrals to professionals in the unit or to other sectors. Furthermore, we found that the process of working nurses face challenges regarding the organizational structure of services and social situation of the family. Given these statements, it is observed that despite the strong interference from hegemonic health model in the performance of nurses, it is found that these professionals have been investing in promotion and prevention to injuries to children in care, with a focus on family context. Thus, nurses are embarking on making the reorientation of health care through the use of relational technologies, which has contributed to solving the integral care to the pediatric population

Seleção seqüencial de descritores por análise da semântica para recuperação de imagens baseada no conteúdo

With the rapid growth of databases of various types (text, multimedia, etc..), There exist a need to propose methods for ordering, access and retrieve data in a simple and fast way. The images databases, in addition to these needs, require a representation of the images so that the semantic content characteristics are considered. Accordingly, several proposals such as the textual annotations based retrieval has been made. In the annotations approach, the recovery is based on the comparison between the textual description that a user can make of images and descriptions of the images stored in database. Among its drawbacks, it is noted that the textual description is very dependent on the observer, in addition to the computational effort required to describe all the images in database. Another approach is the content based image retrieval - CBIR, where each image is represented by low-level features such as: color, shape, texture, etc. In this sense, the results in the area of CBIR has been very promising. However, the representation of the images semantic by low-level features is an open problem. New algorithms for the extraction of features as well as new methods of indexing have been proposed in the literature. However, these algorithms become increasingly complex. So, doing an analysis, it is natural to ask whether there is a relationship between semantics and low-level features extracted in an image? and if there is a relationship, which descriptors better represent the semantic? which leads us to a new question: how to use descriptors to represent the content of the images?. The work presented in this thesis, proposes a method to analyze the relationship between low-level descriptors and semantics in an attempt to answer the questions before. Still, it was observed that there are three possibilities of indexing images: Using composed characteristic vectors, using parallel and independent index structures (for each descriptor or set of them) and using characteristic vectors sorted in sequential order. Thus, the first two forms have been widely studied and applied in literature, but there were no records of the third way has even been explored. So this thesis also proposes to index using a sequential structure of descriptors and also the order of these descriptors should be based on the relationship that exists between each descriptor and semantics of the users. Finally, the proposed index in this thesis revealed better than the traditional approachs and yet, was showed experimentally that the order in this sequence is important and there is a direct relationship between this order and the relationship of low-level descriptors with the semantics of the users

Análise de superfícies seletivas de freqüência para aplicações em ondas milimétricas

This work consists in the development of a theoretical and numerical analysis for frequency selective surfaces (FSS) structures with conducting patch elements, such as rectangular patches, thin dipoles and cross dipoles, on anisotropic dielectric substrates. The analysis is developed for millimeter wave band applications. The analytical formulation is developed in the spectral domain, by using a rigorous technique known as equivalent transmission line method, or immitance approach. The numerical analysis is completed through the use of the Galerkin's technique in the Fourier transform domain, using entire-domain basis functions. In the last decades, several sophisticated analytical techniques have been developed for FSS structure applications. Within these applications, it can be emphasized the use of FSS structures on reflecting antennas and bandpass radomes. In the analysis, the scattered fields of the FSS geometry are related to the surface induced currents on the conducting patches. After the formulation of the scattering problem, the numerical solution is obtained by using the moment method. The choice of the basis functions plays a very important role in the numerical efficiency of the numerical method, once they should provide a very good approximation to the real current distributions on the FSS analyzed structure. Thereafter, the dyadic Green's function components are obtained in order to evaluate the basis functions unknown coefficients. To accomplish that, the Galerkin's numerical technique is used. Completing the formulation, the incident fields are determined through the incident potential, and as a consequence the FSS transmission and reflection characteristics are determined, as function of the resonant frequency and structural parameters. The main objective of this work was to analyze FSS structures with conducting patch elements, such as thin dipoles, cross dipoles and rectangular patches, on anisotropic dielectric substrates, for high frequency applications. Therefore, numerical results for the FSS structure main characteristics were obtained in the millimeter wave bando Some of these FSS characteristics are the resonant

Algoritmo SOM com estrutura hierárquica e dinâmica aplicado a compressão de imagens

ln this work the implementation of the SOM (Self Organizing Maps) algorithm or Kohonen neural network is presented in the form of hierarchical structures, applied to the compression of images. The main objective of this approach is to develop an Hierarchical SOM algorithm with static structure and another one with dynamic structure to generate codebooks (books of codes) in the process of the image Vector Quantization (VQ), reducing the time of processing and obtaining a good rate of compression of images with a minimum degradation of the quality in relation to the original image. Both self-organizing neural networks developed here, were denominated HSOM, for static case, and DHSOM, for the dynamic case. ln the first form, the hierarchical structure is previously defined and in the later this structure grows in an automatic way in agreement with heuristic rules that explore the data of the training group without use of external parameters. For the network, the heuristic mIes determine the dynamics of growth, the pruning of ramifications criteria, the flexibility and the size of children maps. The LBO (Linde-Buzo-Oray) algorithm or K-means, one ofthe more used algorithms to develop codebook for Vector Quantization, was used together with the algorithm of Kohonen in its basic form, that is, not hierarchical, as a reference to compare the performance of the algorithms here proposed. A performance analysis between the two hierarchical structures is also accomplished in this work. The efficiency of the proposed processing is verified by the reduction in the complexity computational compared to the traditional algorithms, as well as, through the quantitative analysis of the images reconstructed in function of the parameters: (PSNR) peak signal-to-noise ratio and (MSE) medium squared error

Análise de antenas de microfita em rampa com múltiplas camadas dielétricas

The present work deals with the ana1ysis of microstrip patch antennas printed on tapered dielectric substrates. We investigate the influence ofthe substrate height variations on the properties of configurations such as microstrip patch antennas, microstrip patch antennas with overlay and suspendeô microstrip patch antennas. The dielectric substrates can be isotropic or anisotropic ones. This accurate analysis is based on the full-wave formulation. It is carried out initially for the determination of the impedance matrix, through the use of the spectral¬domain immitance approach. We use a model based on a segmentation of the considered line into uniform microstrip line subsections. Normalized phase constants and characteristic impedances are obtained by means of the Galerkin numerical technique. Then, the cascaded combination of the uniform microstrip subsections are analyzed through an interactive procedure. Numerical results are presented for the input reflection coefficient, voltage standing wave ratio, resonant frequency, and radiation pattems ofthe E_plane and H-plane diagrams. It is found that the variations in the substrate height profile produce a great influence on the bandwidth of microstrip antennas. This procedure gives bandwidth improvements without altering considerably the resonant frequency. Furthermore, the tapered microstrip antenna can be used as a lightweight altemative for bandwidth control and to eXtend the use of microstiip antenna technology to a wider variety of applications. Finally, suggestions for the continuity of this work are presented

Análise de onda completa de superfície seletiva em freqüência do tipo anteparo duplo

This work presents a theoretical analysis and numerical and experimental results of the scattering characteristics of frequency selective surfaces, using elements of type patch perfectly conductor. The structures are composed of two frequency selective surfaces on isotropic dielectric substrates cascaded, separated by a layer of air. The analysis is performed using the method of equivalent transmission line in combination with the Galerkin method, to determine the transmission and reflection characteristics of the structures analyzed. Specifically, the analysis uses the impedance method, which models the structure by an equivalent circuit, and applies the theory of transmission lines to determine the dyadic Green's function for the cascade structure. This function relates the incident field and surface current densities. These fields are determined algebraically by means of potential incidents and the imposition of the continuity of the fields in the dielectric interfaces. The Galerkin method is applied to the numerical determination of the unknown weight coefficients and hence the unknown densities of surface currents, which are expanded in terms of known basis functions multiplied by these weight coefficients. From the determination of these functions, it becomes possible to obtain numerical scattered fields at the top and bottom of the structures and characteristics of transmission and reflection of these structures. At work, we present numerical and experimental results for the characteristics of transmission and reflection. Comparisons were made with other results presented in literature, and it was observed a good agreement in the cases presented suggestions continuity of the work are presented

Análise espectral de reflectarrays com substratos de duas camadas dielétricas anisotrópicas uniaxiais

Recently, an amazing development has been observed in telecommunication systems. Two good examples of this development are observed in mobile communication and aerospace systems. This impressive development is related to the increasing need for receiving and transmitting communication signals. Particularly, this development has required the study of new antennas and filters. This work presents a fullwave analysis of reflectarrays. The considered structures are composed by arrays of rectangular conducting patches printed on multilayer dieletric substrates, that are mounted on a ground plane. The analysis is developed in the spectral domain, using an equivalent transmission line method in combination with Galerkin method. Results for the reflection coefficient of these structures are presented and compared to those available in the literature. A good agreement was observed. Particularly, the developed analysis uses the transmission lines theory in combination with the incident potentials and the field continuity equations, at the structures interfaces, for obtaining the scattered field components expressions as function of the patch surface currents and of the incident field. Galerkin method is used to determine the unknown coefficients in the boundary value problem. Curves for the reflection coefficient of several reflectarray geometries are presented as function of frequency and of the structural parameters

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