Materiais supercondutores HTS para arranjos de antenas e aplicação de PBG para micro-ondas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Ondas de spin em quasi-cristais magnônicos

In this paper we investigate the spectra of band structures and transmittance in magnonic quasicrystals that exhibit the so-called deterministic disorders, specifically, magnetic multilayer systems, which are built obeying to the generalized Fibonacci (only golden mean (GM), silver mean (SM), bronze mean (BM), copper mean (CM) and nickel mean (NM) cases) and k-component Fibonacci substitutional sequences. The theoretical model is based on the Heisenberg Hamiltonian in the exchange regime, together with the powerful transfer matrix method, and taking into account the RPA approximation. The magnetic materials considered are simple cubic ferromagnets. Our main interest in this study is to investigate the effects of quasiperiodicity on the physical properties of the systems mentioned by analyzing the behavior of spin wave propagation through the dispersion and transmission spectra of these structures. Among of these results we detach: (i) the fragmentation of the bulk bands, which in the limit of high generations, become a Cantor set, and the presence of the mig-gap frequency in the spin waves transmission, for generalized Fibonacci sequence, and (ii) the strong dependence of the magnonic band gap with respect to the parameters k, which determines the amount of different magnetic materials are present in quasicrystal, and n, which is the generation number of the sequence k-component Fibonacci. In this last case, we have verified that the system presents a magnonic band gap, whose width and frequency region can be controlled by varying k and n. In the exchange regime, the spin waves propagate with frequency of the order of a few tens of terahertz (THz). Therefore, from a experimental and technological point of view, the magnonic quasicrystals can be used as carriers or processors of informations, and the magnon (the quantum spin wave) is responsible for this transport and processing

Modelagem do clima de ondas e seus efeitos sobre as feições morfológicas costeiras no litoral setentrional do Rio Grande do Norte

This thesis presents the results of application of SWAN Simulating WAves Nearshore numerical model, OF third generation, which simulates the propagation and dissipation of energy from sea waves, on the north continental shelf at Rio Grande do Norte, to determine the wave climate, calibrate and validate the model, and assess their potential and limitations for the region of interest. After validation of the wave climate, the results were integrated with information from the submarine relief, and plant morphology of beaches and barrier islands systems. On the second phase, the objective was to analyze the evolution of the wave and its interaction with the shallow seabed, from three transverse profiles orientation from N to S, distributed according to the parallel longitudinal, X = 774000-W, 783000-W e 800000-W. Subsequently, it was were extracted the values of directional waves and winds through all the months between november 2010 to november 2012, to analyze the impact of these forces on the movement area, and then understand the behavior of the morphological variations according to temporal year variability. Based on the results of modeling and its integration with correlated data, and planimetric variations of Soledade and Minhoto beach systems and Ponta do Tubarão and Barra do Fernandes barrier islands systems, it was obtained the following conclusions: SWAN could reproduce and determine the wave climate on the north continental shelf at RN, the results show a similar trend for the measurements of temporal variations of significant height (HS, m) and the mean wave period (Tmed, s); however, the results of parametric statistics were low for the estimates of the maximum values in most of the analyzed periods compared data of PT 1 and PT 2 (measurement points), with alternation of significant wave heights, at times overrated with occasional overlap of swell episodes. By analyzing the spatial distribution of the wave climate and its interaction with the underwater compartmentalization, it was concluded that there is interaction of wave propagation with the seafloor, showing change in significant heights whenever it interacts with the seafloor features (beachrocks, symmetric and asymmetric longitudinal dunes, paleochannel, among others) in the regions of outer, middle and inner shelf. And finally, it is concluded that the study of the stability areas allows identifications of the most unstable regions, confirming that the greatest range of variation indicates greater instability and consequent sensitivity to hydrodynamic processes operating in the coastal region, with positive or negative variation, especially at Ponta do Tubarão and Barra do Fernandes barrier islands systems, where they are more susceptible to waves impacts, as evidenced in retreat of the shoreline

Estrutura crustal e mantélica da província Borborema através de funções do receptor e dispersão de ondas superficiais

The Borborema Province, located in northeastern Brazil, has a basement of Precambrian age and a tectonic framework structured at the Neoproterozoic (740-560 Ma). After separation between South America and Africa during the Mesozoic, a rift system was formed, giving rise to a number of marginal and inland basins in the Province. After continental breakup, episodes of volcanism and uplift characterized the evolution of the Province. Plateau uplift was initially related to magmatic underplating of mafic material at the base of the crust, perhaps related to the generation of young continental plugs (45-7 Ma) along the Macau-Queimadas Alignment (MQA), due to a small-scale convection at the continental edge. The goal of this study is to investigate the causes of intra-plate uplift and its relationship to MQA volcanism, by using broadband seismology and integrating our results with independent geophysical and geological studies in the Borborema Province. The investigation of the deep structure of the Province with broadband seismic data includes receiver functions and surface-wave dispersion tomography. Both the receiver functions and surface-wave dispersion tomography are methods that use teleseismic events and allow to develop estimates of crustal parameters such as crustal thickness, Vp/Vs ratio, and S-velocity structure. The seismograms used for the receiver function work were obtained from 52 stations in Northeast Brazil: 16 broadband stations from the RSISNE network (Rede Sismográfica do Nordeste do Brasil), and 21 short-period and 6 broadband stations from the INCT-ET network (Instituto Nacional de Ciência e Tecnologia – Estudos Tectônicos). These results add signifi- cantly to previous datasets collected at individual stations in the Province, which include station RCBR (GSN - Global Seismic Network), stations CAUB and AGBL (Brazilian Lithosphere Seismic Project IAG/USP), and 6 other broadband stations that were part of the Projeto Milênio - Estudos geofísicos e tectônicos na Província Borborema/CNPq. For the surface-wave vii tomography, seismograms recorde at 22 broadband stations were utilized: 16 broadband stations from the RSISNE network and 6 broadband stations from the Milênio project. The new constraints developed in this work include: (i) estimates of crustal thickness and bulk Vp/Vs ratio for each station using receiver functions; (ii) new measurements of surfassewave group velocity, which were integrated to existing measurementes from a continental-scale tomography for South America, and (iii) S-wave velocity models (1D) at various locations in the Borborema Province, developed through the simultaneous inversion of receiver functions and surface-wave dispersion velocities. The results display S-wave velocity structure down to the base of the crust that are consistent with the presence of a 5-7.5 km thick mafic layer. The mafic layer was observed only in the southern portion of the Plateau and absent in its northern portion. Another important observation is that our models divide the plateau into a region of thin crust (northern Plateau) and a region of thick crust (southern Plateau), confirming results from independent refraction surveys and receiver function analyses. Existing models of plateau uplift, nonetheless, cannot explain all the new observations. It is proposed that during the Brazilian orogeny a layer of preexisting mafic material was delaminated, as a whole or in part, from the original Brasiliano crust. Partial delamination would have happened in the southern portion of the plateau, where independent studies found evidence of a more resistant rheology. During Mesozoic rifting, thinning of the crust around the southern Plateau would have formed the marginal basins and the Sertaneja depression, which would have included the northern part of the Plateau. In the Cenozoic, uplift of the northern Plateau would have occurred, resulting in a northern Plateau without mafic material at the base of the crust and a southern Plateau with partially delaminated mafic layer.

A Geração de inovação na carcinicultura do RN: Uma análise a partir da imersão social

This dissertation examines the organizational innovation as a nonlinear process, which occurs in a social and political context and, therefore, socially immersed. Examines the case of shrimp in the state of RN, starting from the following problem: although the norteriograndense shrimp occupies the largest producer of farmed shrimp from Brazil, has a series of bottlenecks concerning the generation of industry innovation, concerning the social relationships and policies between the various actors in the network, whether private or public, and its consequences in terms of opportunity and limits generated for the innovative dynamics. The objective of the research is to understand how the social embeddedness of political actors affects norteriograndense shrimp within the context of structural relations, the industry generation of innovation, throughout its technological trajectory . The approach of social embeddedness balances atomised perspectives, undersocialized and oversocialized, of economic action, considering both the human capacity to act as sources of constraint, whose mechanisms are analyzed the structural and political. In methodological terms this is a case study, analyzed from the research literature, documentary and experimental. Primary data were collected through semi-structured interviews and analyzed in depth by the technique of content analysis. Was adopted a longitudinal approach, seeking to understand the phenomenon from the perspective of the subjects, describing it in an inductive process of investigation. After characterizing the sector and defining their technological trajectory, the analysis of the results followed its four stages: (1) Introduction of Technology: 1973-1980, (2) Intensification of Research: 1981-1991, (3) Technological Adaptation, 1992 -2003, (4) Technological Crisis: 2004-2009. A cross-sectional analysis along the evolutionary trajectory revealed the character of structural changes and policies over time, and implications on the generating process of innovation. Note that, the technological limit to which the sector reached requires changes in technology standards, but is more likely that the potiguar shrimp is entering a new phase of his career in technology rather than a new technological paradigm

Jovens terena na cidade de Campo Grande (MS) Política e geração

Research with indigenous in urban context are gaining steam in recent years, particularly with the intensification of migration resulting from problems such as lack of land for subsistence. However, in relation to Terena, subjects in this study, the contemporary anthropological research aimed at residents in cities still are not privileged, especially to youth. Thus, the dissertation has as main objective the discussion around some axes, among them indigenous youth Terena ethnicity politics, - indigenous movement - and racism. These themes appeared during fieldwork where privileged six trajectories of young Terena who migrated to Campo Grande (MS) and have different ways to mean the city and experiencing everyday life

Influência do método de síntese e caracterização de pós compósitos de NiO- Ce1-xEuxO2-δ para anodos catalíticos de células a combustível

Fuel cells are electrochemical devices that convert chemical energy into electricity. Due to the development of new materials, fuel cells are emerging as generating clean energy generator. Among the types of fuel cells, categorized according to the electrode type, the solid oxide fuel cells (SOFC) stand out due to be the only device entirely made of solid particles. Beyond that, their operation temperature is relatively high (between 500 and 1000 °C), allowing them to operate with high efficiency. Another aspect that promotes the use of SOFC over other cells is their ability to operate with different fuels. The CeO2 based materials doped with rare earth (TR+3) may be used as alternatives to traditional NiO-YSZ anodes as they have higher ionic conductivity and smaller ohmic losses compared to YSZ, and can operate at lower temperatures (500-800°C). In the composition of the anode, the concentration of NiO, acting as a catalyst in YSZ provides high electrical conductivity and high electrochemical activity of reactions, providing internal reform in the cell. In this work compounds of NiO - Ce1-xEuxO2-δ (x = 0.1, 0.2 and 0.3) were synthesized from polymeric precursor, Pechini, method of combustion and also by microwave-assisted hydrothermal method. The materials were characterized by the techniques of TG, TPR, XRD and FEG-SEM. The refinement of data obtained by X-ray diffraction showed that all powders of NiO - Cex-1EuxO2-δ crystallized in a cubic phase with fluorite structure, and also the presence of Ni. Through the characterizations can be proved that all routes of preparation used were effective for producing ceramics with characteristics suitable for application as SOFC anodes, but the microwave-assisted hydrothermal method showed a significant reduction in the average grain size and improved control of the compositions of the phases

Síntese hidrotérmica assistida por micro-ondas de tiO2, e aplicação em nanocompósito

In recent decades have seen a sharp growth in the study area of nanoscience and nanotechnology and is included in this area, the study of nanocomposites with self-cleaning properties. Since titanium dioxide (TiO2) has high photocatalytic activity and also antimicrobial, self-cleaning surfaces in your application has been explored. In this study a comparison was made between two synthesis routes to obtain TiO2 nanoparticles by hydrothermal method assisted by microwave. And after analysis of XRD and SEM was considered the best material for use in nanocomposites. It was deposited nanocomposite film of poly (dimethyl siloxane) (PDMS) with 0.5, 1, 1.5 and 2% by weight of nanoparticles of titanium dioxide (TiO2) by the spraying method. The nanocomposite was diluted with hexane and the suspension was deposited onto glass substrate, followed by curing in an oven with forced air circulation. The photocatalytic activity of the nanocomposite impregnated with methylene blue was evaluated by UV- vis spectroscopy from the intensity variation of absorption main peak at 660nm with time of exposure to the UV chamber. Changes in the contact angle and microhardness were analyzed before and after UV aging test. The effect of ultraviolet radiation on the chemical structure of the PDMS matrix was evaluated by spectrophotometry Fourier transform infrared (FTIR).The results indicated that the addition of TiO2 nanoparticles in the coating PDMS gave high photocatalytic activity in the decomposition of methylene blue, an important characteristic for the development of self-cleaning coatings

Estudos analíticos dos grafoelementos do eletroencefalograma em sono: fusos do sono, ondas agudas do vértex e o gradiente de freqüência e amplitude, como indicadores de comprometimento neurológico na criança

Innumerable studies have focused been reported on the sleep spindles (SS), Sharp Vertex Waves (SVW) and REM, NREM Sleep as indicators interpreting EEG patterns in children. However, Frequency and Amplitud Gradient (FAG) is rarely cited sleep parameter in children,that occurs during NREM Sleep. It was first described by Slater and Torres, in 1979, but has not been routinely evaluated in EEG reports. The aim of this study was to assess the absence of SS, SVW and FAG, as an indication of neurological compromise in children. The sample consisted of 1014 EEGs of children referred to the Clinical Neurophysiology Laboratory, Hospital Universitário de Brasília (HUB), from January 1997 to March 2003, with ages ranging from 3 months to 12 years old, obtained in spontaneous sleep or induced by choral hydrate. The study was transversal and analytical, in which, visual analysis of EEG traces was perfumed individually and independently by two electroencephalographers without prior knowledge of the EEG study or neurological findings. After EEG selection, the investigators analyzed the medical reports in order to define and correlate neurological pattern was classified according to the presence or absence of neurological compromise, as Normal Neurological Pattern (NNP), and Altered Neurological Pattern (ANP) respectively. From the visual analysis of the EEG(s), it was possible to characterize 6 parameters: 1- FAG present (64,1%); 2- FAG absent (35,9%); 3 - normal SS (87,9%); 4 - altered SS s (12,1%); 5 - normal SVW s (95,7%); 6 - altered SVW s (4,3%). The prevalence of well-formed FAG is found in the 3 months to 5 years age group in the children with NNF. FAG was totally absent from the age of 10 years. When comparing the three sleep graphielements, it was observed that SVW and SS were predominant in children with NNF. However, FAG absent was more prevalent in the ANF than in altered SS an SVW. The statistical analysis showed that there is a strong association of FAG absent, with isolated alteration, in ANF patients, in that the prevalence ratio was 6,60. The association becomes stronger when FAG absent + altered SS(s) is considered (RP= 6,68). Chi-square test, corrected by Yates technique, showed a highly significant relation for FAG ρ= 0,00000001, for error X of 5%, or else the 95% confidence interval (ρ<0,05). Thus, the FAG absent were more expressive in ANF patient than altered SS(s) and SVW(s). The association becomes stronger in order to establish a prognostic relation, when the FAG is combined with the SS. The results os this study allow us to affirm that the FAG, when absent at ages ranging from 3 months to 5 years , is an indication of neurological compromise. FAG is an age-dependent EEG parameter and incorporated systematically, in the interpretation criteria of the EEG of children s sleep, not only in the maturational point of view, but also neurological disturbances with encephalic compromise

Dos movimentos sociais às funções institucionais: a Consolidação de uma geração política em Sergipe.

This study was presented to the Post-Graduation Program in Social Sciences at UFRN as part of the requisites for obtaining the title of Master in Social Sciences. It describes the results of the research From social movements to the institutional functions: the consolidation of a generation . Its main objective is to describe the history of a political generation that emerged from the social movements, in the 80 s, in Sergipe, and that nowadays occupies the main governmental positions in the State s political scenario. As its specific objectives, the research described the emerging of social movements in the 80s in Sergipe; it found in the social movements in Sergipe, in the 80s, the beginning of the history of a new political generation, and described the consolidation of this new political generation in institutional positions as the expression of a new group of power in Sergipe s politics. Among the social movements that gained visibility in that period and that projected their leadership into the political scenario of Sergipe, this study highlights: the students movement, teacher s movement, bank clercks movement, miners movement, and rural workers movement. It utilized as methodology the research in sites, magazines, and the use of testimonies from semi-structured interviews. The main leadership of the five movements that were analyzed is, nowadays, governing the state, administering the capital s city hall, and performing legislative work at the Legislative Assembly of Sergipe, and at the Chamber of City Councilmen of Aracaju. This study described the political history of the main leadership of that generation of militants and organizers of social movements, and of left party groups in Sergipe, highlighting that their consolidation in the political scenario of the State meant the consolidation of a new group of power in Sergipe s politics.

Geração de renda e ocupações na cadeia agroindustrial de castanha de caju no Rio Grande do Norte: o caso do sertão de Apodi

This work is part of the research group studying agribusiness chains, by characterizing agroindustrial chain of cashew nuts in Rio Grande do Norte, with special emphasis on Sertão de Apodi Citizenship Territory, showing their different flows and linkages and analyzes generating jobs and income in the production of this good, from the experience of COOPAPI, using as a methodology for analyzing the input-output matrix. And this is justified by the fact that Brazil is in the context as the world's fifth largest producer of cashew nuts and the production of this product focus in the Northeast, especially the Rio Grande do Norte, which is the second largest producer of region, behind only the state of Ceará, which is the largest producer in the country. Moreover, in recent years the state has increased its insertion in international markets this product, particularly the Mossoró-Assu Territory, which constitutes the largest producer in the state, particularly the municipality of Serra do Mel, which has an arrangement different yield, based on the model of integrated rural development, embodied in family farming. Nevertheless, the Sertão de Apodi Citizenship appear as the fourth among the Citizenship territories of Rio Grande do Norte in the ranking of the production of cashew nuts, but the prevailing model of Cooperatives in the Territory, based on the Solidarity Economy, i,e, different from the old cooperative, which is based on the precepts as patronage, with cooperative owners, favor, etc.., encourages scientific research. In this, after a careful analysis of data from field research, it was noticed that among the links in the chain, the production link is what generates the most jobs, while the processing link commands to generate income, but a portion meaningful occupations and income are generated outside the territory, especially out of state RN, denouncing the gap in supply of some specific demands within the chain

Navegando nas ondas dos saberes do ser: uma conversa com a sexualidade à luz da corporeidade.

This study aimed to provide a continuing education towards raising teachers for reflection and effective sexual education within the school environment as a possible route of self-education and training of teachers of elementary school. More specifically aim to facilitate through the Continuing Education to discuss the knowledge of the body and knowledge of human sexuality, presenting them as core knowledge in the integral formation of individuals and promote discussion of a Human-centered education Teaching in a vocational training and human .In this sense, we dialogue with the human teaching preconized by Arroyo (2002, 2004) along with the humanization (hominization) of the individuals through education, under Freire´s perspective of the being more (2003) as well as his ideas, Pineau´s (2003) and Josso´s (2004) about the educational practice understanding as a way to build up the autonomy of the individuals who we intend to educate. We defend the inclusion of the body as an essential learning element according to the principles of corporeity presented by Assman (2001), whose comprehension is that every learning experience has a corporal inscription. Furthermore, the knowledge about human sexuality cannot be excluded from this process since the sexuality is inherent of individuals and is constructed and reconstructed during their existence. Our view of the world and of man is supported by the knowledge of the complexity (Morim, 2004) trying to surpass the mechanist view that sees them through the duality view, fragmenting them. For the discussion and construction of knowledge that search for the confluence of these knowledges about the being and the educational practice, aiming at the individual integral formation starting from the process of self-formation/self-knowledge, we´ve directed our research-action-formation having as compass the theoretical-methodological postulate of the research-action (Barbier, 2002; Morin, 2004; Thiollent, 2004) because it makes the participation of all the involved people in the process of resolution or surpassing of problem solving possible. We´ve used the continuing formation as a way of access for data collection, applying a questionnaire with open questions for the ones involved in the research. Based on the findings it´s been possible to infer that for the teaching formation it is necessary the inclusion of the Human sexuality and corporeity theme, so that the teacher can surpass the biological view of sexuality and also the expansion of the mechanist view of the body. To do so, we suggest that the teaching formation happens supported by the teaching capacitation and formation according to Maturana (2004), bringing teaching knowledges (Tardiff, 2002), which contribute effectively for the responsibility to educate people for life.

Formação de educadores de jovens e adultos no Programa Geração Cidadã: relação entre saberes na proposição curricular

This paper deals with the fundamental elements of a curricular proposal aiming at the formation of alphabetizers of young and adults, as long as it concerns the relation between the academic knowledge and that one arising from the classroom experience. The empirical field of the research comes from the work of the teachers responsible for the formation of the alphabetizers of the GerAção Cidadã Program (2004-2005) linked, as an Extension Program, to Federal University of Rio Grande do Norte. Indeed, it tries to understand how these young and adult educators makers figure out the link between the experienced knowledge, which their lives give testimony of, with the scientific knowledge, which they are entitled to mediate in class. This work is funded in the principles of the Collaborative Research, which constitutes a kind of qualitative research. It makes use of procedures supported by qualitative research, especially those ones related to reflexive sessions, as well as to documental researches and semi-structured interviews. These spaces have afforded the group of alphabetizers the opportunity to talk over their practice, not only individually but also collectively, in order to work out contributive proposals having in view changes in the educative actions. As elaborated contributions, we present a discussion about the specificities in the making of educators to EJA, in their differentiated social roles. Reflecting on the experiences of the educators makers, we highlight those elements we regard as essential to the constitution of a formation proposal, like formative times and spaces, dialogue and social memory. The curricular organization is compreneded as part of an enlarged dimension that does not restraint itself to school; rather, it is visualized as a structuring instance that connects different knowledge surpassing community and university. Under this optics, we come to the conclusion that the connection the scientific knowledge establishes with the experienced one, which is immersed in the cultural practices of those who are involved in the formative process, is the basement to a curricular proposal of a formation course destined to educators committed with the need of changing society

Fatores de decisão da adoção do gás natural na geração de energia elétrica em pequena escala em postos de combustíveis: um estudo de anális de decusão usando o processo de hierarquia analítica AHP

A modeling of criterias and alternatives is through and applied a questionnaire based on method AHP to proprietors of gas stations. The considered alternatives had been the maintenance of the current state with electric energy of the deliverer and the generation in small scale based on the natural gas. The used criteria had been Cost of the Investment, Final Cost of the Energy, Operational cost, Ambient Benefits, Risk and Variation of Costs. The study it was carried through in the city of Natal, RN in ranks that make use of the natural as for resale, where the generation alternative on the basis of the available gas is present. The main results evidence in a dimension the viability of use of method AHP with questionnaire by means of validation of the judgments with analysis of variance beyond proper the normal mechanisms of analysis of consistency to the method. The main results of the analysis help to show that in this in case that the profile of models of criteria and judgments of the actors is similar, with the final evidence of that it has a dominance of the maintenance of the energy of the deliverer. The main criterion to influence this decision was the risk

Critérios na tomada de decisão estratégica em projetos de co-geração a gás natural: um estudo em hospitais

This thesis deals with analyzing the actual perception of the brazilian hospital managers about natural gas fired cogeneration. An study of case is developed to obtain information about the viability of the investments in cogeneration technolgies in four hospitals. These studies are made using a questionnaire, to know and to obtain necessaries data of the managers. The main results shows that the investors have a bad feeling about to invest in a different activity. In other hand, the results show that the investors have a good impression about the configuration of the project that uses the project finance like way of financing