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

Desenvolvimento de antenas de microfita com aberturas nos patches condutores através do método da segmentação

Microstrip antennas are widely used in modern telecommunication systems. This is particularly due to the great variety of geometries and because they are easily built and integrated to other high frequency devices and circuits. This work presents a study of the properties of the microstrip antenna with an aperture impressed in the conducting patch. Besides, the analysis is performed for isotropic and anisotropic dielectric substrates. The Multiport Network Model MNM is used in combination with the Segmentation Method and the Greens function technique in the analysis of the considered microstrip antenna geometries. The numerical analysis is performed by using the boundary value problem solution, by considering separately the impedance matrix of the structure segments. The analysis for the complete structure is implemented by choosing properly the number and location of the neighboor element ports. The numerial analysis is performed for the following antenna geometries: resonant cavity, microstrip rectangular patch antenna, and microstrip rectangular patch antenna with aperture. The analysis is firstly developed for microstrip antennas on isotropic substrates, and then extended to the case of microstrip antennas on anisotropic substrates by using a Mapping Method. The experimental work is described and related to the development of several prototypes of rectangular microstrip patch antennas wtih and without rectangular apertures. A good agreement was observed between the simulated and measured results. Thereafter, a good agreement was also observed between the results of this work and those shown in literature for microstrip antennas on isotropic substrates. Furthermore, results are proposed for rectangular microstrip patch antennas wtih rectangular apertures in the conducting patch

Análise da magnetohidrodinâmica com transferência de calor em canais de placas paralelas via transformação integral

The main goal of the present work is related to the dynamics of the steady state, incompressible, laminar flow with heat transfer, of an electrically conducting and Newtonian fluid inside a flat parallel-plate channel under the action of an external and uniform magnetic field. For solution of the governing equations, written in the parabolic boundary layer and stream-function formulation, it was employed the hybrid, numericalanalytical, approach known as Generalized Integral Transform Technique (GITT). The flow is sustained by a pressure gradient and the magnetic field is applied in the direction normal to the flow and is assumed that normal magnetic field is kept uniform, remaining larger than any other fields generated in other directions. In order to evaluate the influence of the applied magnetic field on both entrance regions, thermal and hydrodynamic, for this forced convection problem, as well as for validating purposes of the adopted solution methodology, two kinds of channel entry conditions for the velocity field were used: an uniform and an non-MHD parabolic profile. On the other hand, for the thermal problem only an uniform temperature profile at the channel inlet was employed as boundary condition. Along the channel wall, plates are maintained at constant temperature, either equal to or different from each other. Results for the velocity and temperature fields as well as for the main related potentials are produced and compared, for validation purposes, to results reported on literature as function of the main dimensionless governing parameters as Reynolds and Hartman numbers, for typical situations. Finally, in order to illustrate the consistency of the integral transform method, convergence analyses are also effectuated and presented

Elaboração e aplicação de uma estratégia de ensino sobre os conceitos de calor e de temperatura

This piece of work has investigated the alternative conceptions shown by students of secondary school, concerned to the concepts of warmth and temperature, aiming the elaboration and application of a learning strategy as of the diagnose risen from the conceptions present in students. The learning strategy was built up by a sequence of activities that involve History of Science and experiments, put in a course that had as a base the proposal of the Group of Redevelopment of Physics Teaching (GREF). We have used as the conductor wire of our research the development of thermo dynamics since the development of the first thermo machines, passing by the Industrial Revolution and the evolution of concepts of warmth and temperature. The learning strategy was applied to a group of second grade of secondary school in a public school in Mossoró (RN). By doing these activities we tried to become the concepts, which are part of thermo dynamics, more meaningful to the students. We have estimated that the application of the strategy has represented some profits to the students of the group, concerning to learning of laws and concepts of thermo dynamics (specifically the concepts of warmth and temperature), as well as what it is referred to the overcoming of its initial conceptions

Marcas da escritura oralizada em Sagarana

This work presents a surveyabout the short stories of Sagarana. first book by Guimarães Rosa, publishedin 1946, and that marked the Brazilian litterature definitely, since we are in front of a new construction of the language, linked to the establishment of a new Portuguese, trough the association between the cult speech and the speech from the sertão, always with a pretence sensitivity that rouses when joins archaisms, neologisms, regional expressions and literary language. Among the nine short stories that made up the work, we will select the following ones, to be analysed: "O Burrinho Pedrês", Traços Biográficos de Lalino Salãthiel ou A volta do marido pródigo , "São Marcos" and A hora e vez de Augusto Matraga". Among the hypothesis that organize and surround this work, we will approach the narrative aesthetics, the creative process and the orallity, i.e., how Rosa trans1ate the oral world, rescuing the archaizing speech in the written narrative construction.We will choose for the establishment of developed questions in this ressearch the theories of Paul Zumthor, Câmara Cascudo, Sílvio Romero, Antonio Candido and Alfredo Bosi, among others. Therefore, we will see, through the narrative reading, how the popular parlances are used, which they are linked. The citations that show the popular tradition presence will be pointed out, through anecdotes, folk songs, legends, myths, folktales and proverbs. Therefore, we, readers, will see the popular tradition presence, that will show itself, and the Rosa's thinking will be known through language art, what is the result of the writer's deliberate choice. We will see the popular experience turned to art

O chiste em Tutaméia: riso que (des)vela

The aim of this paper is to present the study of the laughter in Tutaméia, by João Guimarães Rosa, throughtout the four forewords and ten novels selected from the author s literary work. It is based on the psychoanalytical theory of Sigmund Freud and Jacques Lacan about the laughter (and delight in the humorous nuances) and the unconscious mind. By taking the laughter as the point of exploitation and understanding, the narration can be understood from an esthetical pattern established on the variety of orallity retained by the narrator and the cordel pamphlets (known as string literature ) and its bypassing on the classical literature and the popular literature revealing its own logical linguistic and conception apart from the official one. It is taken a comparative conception of life in the François Rabelais characters and some characters from Tutaméia having Melim-Meloso as a paradigm showing how one s life can be happy in spite of all adversities by using laughter as the antidote potion against human being s misery and pain to achieve sense of freedom and pleasure

Um ser de lá do sertão e a construção da(s) suas(s) identidade(s) no discurso cancionista nordestino

This work was formulated in order to study the use of words in a specific sphere of human communication - the world of music. From a selection of compositions by Luiz Gonzaga (1912 -1989) and partners, the research goes in search of the identity(ies) of the migrant from Brazilian Northeast's "sertão". The work uses a discursive analysis based on a theoretical framework strongly supported by Mikhail Bakhtin's reflections and whose thread is the theme of migration discussed by Zygmunt Bauman. Thus, this qualitative and interpretivist research focuses on a particular type of text, originating from a specific sphere of human communication that is roughly known as "lyrics" ("words of songs")

O exílio no romance primavera com una esquina rota de Mario Benedetti

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Das cinzas aos mafuás: infância e morte na lírica de Manuel Bandeira

Cet article étudie la poésie de l'enfance et de la mort de Manuel Bandeira, à partir de la relation entre l'expérience, le langage et le sens, afin de mettre en place une nouvelle perspective sur ce thème, qui sert de guide et structure son Estrela da vida inteira (1966). Pour cela, il faut introduire la notion de lyrique, discutée par Theodor Adorno, pendant la conférence Lírica e sociedade (1958), à promouvoir la compréhension du poète, comme c'est le cas de Bandeira, implique son art par le biais de la dimension négative face à une situation de fétichisation des choses, afin d'appréhender des expériences qui constituent la substance de la vie et l'essence de la poésie. À cette perspective de lyrique s ajoutent les concepts de l'enfance et de la mort, exploités par Giorgio Agamben, dans les oeuvres Infância e história (2005) et A linguagem e a morte (2006), étant largement favorables à la compréhension de la poétique de l'enfance chez Manuel Bandeira, comme une sorte de discours qui récupère l'idée d'expérience dans l actualité, en marquant la limite entre une expérience muette et une expérience de la langue, de même, la mort apporte des implications relatives à la négativité, comme une brèche par laquelle l'auteur explore la signification de sa lyrique et la«dénoue» des incrustations du monde réifié, pour être dans la défense du langage non contaminé par le clôturée qui entravent la conservation de la créature et la donnée originaire des choses . Cela culmine l aboutissement de la thèse, la conclusion d être la négativité la voie qui explicite, dans l oeuvre bandeirienne, la culture brésilienne non comme une totalité positivée dans une ethnie, classe ou nation, mais comme un langage qui reconstruit, avec lyrisme, le coloré mosaïque qui est le Brésil

Lógos e noûs no Fedro de Platão

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Sujeito e liberdade no pensamento de Michel Foucault

The leitmotif of this dissertation research is on the relationship between two fields of questioning in the Foucauldian works that may be considered, at a first glance, irreconcilable: the understanding of subject as the result of determinations, on the one hand, and its ethical stance of seeking the creation of liberty, on the other. Since, despite this apparent inconsistency, both ideas are present with much emphasis on the work of the French thinker, to understand the way Foucault articulated these two ideas was necessary to elucidate and interrelate the way in which he thought about the concepts of subject, power and liberty. Traveling with the author his intellectual itinerary, it was revealed that his conception of subject and liberty can be reconciled (although maintaining its problematic nature) and, also, both are inextricably linked each one as a result of the other. Tracing, with the author, his intellectual itinerary, it was also possible to identify and describe the fruitful conceptual tools for thinking about our own determinations and about the possibilities we have of creating new subjectivities and liberating experiences

A coleção mossoroense e a construção dos mitos: Dix-Sept Rosado, o herói imolado

This research comprises a study on the values and ideals attributed to Dix-sept Rosado, by the Coleção Mossoroense journal. Local researchers demonstrate how the Coleção Mossoroense constructs an image of Mossoró, forming in the members of the city an identity with the place, a social cohesion or creating one forms to see and to say about the Mossoró city. The Coleção Mossoroense, through Vingt-un Rosado together with its family, established a form of seeing and identifying of the Mossoró s population with the city, just because it associated and it was, at the same time, a movement at the same time social (civic parties for example), political (the domination of the Rosado s family) and cultural (the books and theatrical parties about the city). The conjunction of the Coleção Mossoroense as and with a social movement, cultural and political was capable to establish a social identity, a subjective constituent . With this background, it was possible to make a study of the image attributed to Dix-sept Rosado, by the Coleção Mossoroense, through an analysis of the inherent discourse in the works by Bakhtin (1989) and Bourdieu (2000), of and on Dix-sept Rosado in the Coleção Mossoroense based on. The image of Dix-sept Rosado was constructed by the Coleção Mossoroense after its death, and the responsible for this was Vingt-un Rosado, which was the chief-editor of the Coleção Mossoroense up to 2006, year of its death. The Coleção Mossoroense built an image of Dix-sept Rosado as an enterprising man, progressive and innovator, of great capacity of leadership and oratory (a conductor of the crowds ), popular and charismatic, an honest and dynamic politician. This image made by the Coleção Mossoroense, although when enhancing in surplus the qualities of Dix-sept Rosado have as objective to transmit an image of a heroic personage, it has some relation with the reality. Dix-sept Rosado was a man identified with its locality. This can resemble a regional nationalism. The attitudes of Dix-sept Rosado must be understood inside of a broader social context, of a time marked by the populist politics. Qualities also appreciated and developed inside of a specific historical context and determined both national and locally. The Coleção Mossoroense enhances the qualities of Dix-sept Rosado so that the current politicians of the Rosado s family can establish a link of continuity in its contemporary political practice

Urbanização turística em ponta negra: relações de força e processos sociais no período de 1979-2009

This master thesis aimed to investigate how the power relations operating in the tourism social processes, have shaped the urbanization of Ponta Negra district, Natal, Rio Grande do Norte - RN. The study assumes that the production of space is the result of global phenomena individualized by local forces a process of glocalization. The method used was the case study. It used primary and secondary data and information were treated using the technique of content analysis. The urbanization of Ponta Negra is inserted in the context of global process triggered in the 1970s. The Park of Dunas and Costeira Highway (PD/VC) urbanization project marks the beginning of the Tourisms since 1979. The period in focus was 1979 to 2009. The tourism was dived into four major sections time: tourism in Natal before the Coastal Highway (1939-1979); Project Parque das Dunas / Coastal Highway to the first boom in domestic tourism (1979 - 1990); the internationalization of tourism (1991-2000) and, of first "boom" to "decline" of international tourism (2001-2009). Based on the historical evolution of the tourism were elected three different social processes, able to demonstrate how relations of social forces brought in space act on them and help shape the process of urbanization of the neighborhood in question: The removal of beach hut , the soccer field Botafogo Football Club and the skyscrapers . Finally, it should summarize the research identified interests and conflicts among the actors that form the thrust of spatial transformations: cultural conflicts resulting from the imposition of social practices that differ from the taste of native; clashes between different groups that reflect the duality between use value and exchange value; and interests in land values. In addition, demonstrated that the social relations that involve the production of the area are stimulated by deep-seated societal processes historically and camouflaged by market relations and a modern facade that the city has acquired in recent times; revealed that the actors are linked in networks to increase their influence and that this influence varies mainly according to economic and political power that they or their associates hold

Uma nova proposta de antena planar multibanda para comunicações móveis

The great interest observed in wireless communication systems has required the development of new configurations of microstrip antennas, because they are easily built and integrated to other microwave circuit components, which is suitable for the construction and development of planar antenna arrays and microwave integrated circuits. This work presents a new configuration of tapered microstrip antenna, which is obtained by impressing U-slots on the conducting patch combined with a transmission line matching circuit that uses an inset length. It is shown that the use of U-slots in the microstrip antenna conducting patch excites new resonating modes, that gives a multiband characteristic for the slotted microstrip antenna, that is suitable for applications in communication systems that operates several frequencies simultaneously. Up to this date, the works reported in the literature deals with the use of Uslotted microstrip rectangular antennas fed by a coaxial probe. The properties of a linear array of microstrip patch tapered antennas are also investigated. The main parameters of the U slotted tapered microstrip antennas are investigated for different sizes and locations of the slots impressed on the conducting patch. The analysis of the proposed antenna is performed by using the resonant cavity and equivalent transmission line methods, in combination with a parametric study, that is conducted by the use of the Ansoft Designer, a commercial computer aided microwave software well known by its accuracy and efficiency. The mentioned methods are used to evaluate the effect in the antennas parameters, like resonant frequency and return loss, produced by variations of the antenna structural parameters, accomplished separately or simultaneously. An experimental investigation is also developed, that consists of the design, construction and measurement of several U slotted microstrip antenna prototypes. Finally, theoretical and simulated results are presented that are in agreement with the measured ones. These results are related to the resonating modes identification and to the determination of the main characteristics of the investigated antennas, such as resonant frequency, return loss, and radiation pattern

Ser cuidador de paciente com acidente vascular cerebral: histórias não contadas

The present study aimed to understand the experience of being a family caregiver of a patient with Cerebrovascular Accident (CVA). The relevance of the study is to prove existence of a large number of caregivers of incapacitated patients, due to the CVA and it is not an academic research object, according to the literature. It is a qualitative research, which the guiding principle is the oral history of life, according to the theoretical foundation and operating of Meihy. Therefore, the following steps were highlighted: the target community, composed of all family caregivers of CVA patients; the colony, composed by family caregivers of CVA patients assisted by Home Care Service (HCS) of the Hospital José Pedro Bezerra (HJPB), in the city of Natal/RN; the network was composed of six caregivers who met the criteria for inclusion, and as zero point the first volunteer group. The population was composed of all family caregivers of patients attended by the HCS, of the HJPB having been addressed through interviews. For the empirical research there was the consent of that institution and approval by the Ethics Committee in Research of the Federal University of Rio Grande do Norte as CAAE 24569413.0.0000.5537 and, above all, with the acquiescence of employees in participating in the investigation, signing an informed consent. Of the empirical material, five categories of analysis were identified: the sense of being a caregiver; what has changed in the life of the caregiver; the feelings emerge in the relationship of care; the distance from family and friends; difficulties faced by the caregiver. The results show that the caregiver's life goes through profound transformations within the family as well as in all spheres of life. For the caregivers, assuming the care of a relative with CVA means renunciation and donation, compromising sometimes the individual projects and the family as a whole. In addition, they point out the confrontation of difficulties within the the assistance and humanization in healthcare, information, physical and emotional overload, as well as financial problems. Despite all the adversities that compromise the caregiver's life, it was possible to identify attitudes of resilience among caregivers, making them their daily life less strenuous and with more lightness. It is expected, therefore, that this research can contribute to a better orientation of professionals with the caregivers