998 resultados para fluxos


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João Pessoa, the capital city of the state of Paraíba (Northeast Brazil), is reputed throughout the country as a quiet place, although it has been acquiring, over the past years, an urban character with social implications similar to those of major metropolitan Brazilian areas. The new situation is evident by the social inequalities, with the creation of confined spaces, which segregate and cause enclosure of the inhabitants, leading to death the public space. This study correlates accessibility in spatial structure with two types of crime data, burglary and robbery, recorded in 2008 and 2009, by the Secretaria de Segurança da Paraíba (The government agency public in charge of safety), in the district of Manaíra, an upper middle class neighborhood, which has, in recent times, been considered one of the most violent areas in João Pessoa. Sought to understand connections between these events and morpho-social aspects of the built environment, where examined the spatial properties, such as accessibility of the urban net, the presence of control measures, the safety of buildings and their uses. Spatial properties were also validated by the observation of pedestrian flows at strategic points of the study area. It was concluded that the presence of intense flows helps to attract potential thieves, physical security and control offers little protection

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This study reviews the spatial configuration from the road network of an urban compound formed by the cities of Crato, Juazeiro do Norte and Barbalha (the Crajubar - core of the Cariri metropolitan region, in the State of Ceará, Brazil), in order to establish nexus (or relations) between different levels of accessibility and the formation/ transformation and specialization of centralities in local and metropolitan scales. Stemming from the Social Logic of Space theoretical and operational apparatus, the study explores modeling possibilities (with axial lines, segments and lines of continuity) which is then confronted to empirical observations concerning movement flows and land use, within a Geographic Information System database. At different scales of analysis, the results suggest evidences of continuity were found in the permanence of intra-urban centres and sub-centres within each town, whereas evidences of change pointed out to the formation of a new centrality of metropolitan magnitude in the neighbourhood referred to as the Triângulo, in the municipality of Juazeiro, where high levels of topological accessibility coincides with the appearance of new business buildings as well as with the emergence of urban equipment of a scale more adequate to meet a regional demand

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Physical-chemical properties of Ti are sensible to the presence of interstitial elements. In the case of thermochemical treatments plasma assisted, the influence of different active species is not still understood. In order to contribute for such knowledge, this work purposes a study of the role played by the active species atmosphere into the Ar N2 CH4 carbonitriding plasma. It was carried out a plasma diagnostic by OES (Optical Emission Spectroscopy) in the z Ar y N2 x CH4 plasma mixture, in which z, y and x indexes represent gas flow variable from 0 to 4 sccm (cm3/min). The diagnostic presents abrupt variations of emission intensities associated to the species in determined conditions. Therefore, they were selected in order to carry out the chemical treatment and then to investigate their influences. Commercial pure Ti disks were submitted to plasma carbonitriding process using pre-established conditions from the OES measurements while some parameters such as pressure and temperature were maintained constant. The concentration profiles of interstitial elements (C and N atoms) were determined by Resonant Nuclear Reaction Analysis (NRA) resulting in a depth profile plots. The reactions used were 15N(ρ,αγ)12C and 12C(α,α)12C. GIXRD (Grazing Incidence X-Ray Diffraction) analysis was used in order to identify the presence of phases on the surface. Micro-Raman spectroscopy was used in order to qualitatively study the carbon into the TiCxN1 structure. It has been verified which the density species effectively influences more the diffusion of particles into the Ti lattice and characteristics of the layer formed than the gas concentration. High intensity of N2 + (391,4 nm) and CH (387,1 nm) species promotes more diffusion of C and N. It was observed that Hα (656,3 nm) species acts like a catalyzer allowing a deeper diffusion of nitrogen and carbon into the titanium lattice.

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Titanium nitride films were grown on glass using the Cathodic Cage Plasma Deposition technique in order to verify the influence of process parameters in optical and structural properties of the films. The plasma atmosphere used was a mixture of Ar, N2 and H2, setting the Ar and N2 gas flows at 4 and 3 sccm, respectively and H2 gas flow varied from 0, 1 to 2 sccm. The deposition process was monitored by Optical Emission Spectroscopy (OES) to investigate the influence of the active species in plasma. It was observed that increasing the H2 gas flow into the plasma the luminescent intensities associated to the species changed. In this case, the luminescence of N2 (391,4nm) species was not proportional to the increasing of the H2 gas into the reactor. Other parameters investigated were diameter and number of holes in the cage. The analysis by Grazing Incidence X-Ray Diffraction (GIXRD) confirmed that the obtained films are composed by TiN and they may have variations in the nitrogen amount into the crystal and in the crystallite size. The optical microscopy images provided information about the homogeneity of the films. The atomic force microscopy (AFM) results revealed some microstructural characteristics and surface roughness. The thickness was measured by ellipsometry. The optical properties such as transmittance and reflectance (they were measured by spectrophotometry) are very sensitive to changes in the crystal lattice of the material, chemical composition and film thicknesses. Therefore, such properties are appropriate tools for verification of this process control. In general, films obtained at 0 sccm of H2 gas flow present a higher transmittance. It can be attributed to the smaller crystalline size due to a higher amount of nitrogen in the TiN lattice. The films obtained at 1 and 2 sccm of H2 gas flow have a golden appearance and XRD pattern showed peaks characteristics of TiN with higher intensity and smaller FWHM (Full Width at Half Maximum) parameter. It suggests that the hydrogen presence in the plasma makes the films more stoichiometric and becomes it more crystalline. It was observed that with higher number of holes in the lid of the cage, close to the region between the lid and the sample and the smaller diameter of the hole, the deposited film is thicker, which is justified by the most probability of plasma species reach effectively the sample and it promotes the growth of the film

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Interstitial compounds of titanium have been mainly studied due to the large range of properties acquired when C, N, O and H atoms are added. In this work, surfaces of TiCxNy were produced by thermochemical treatments assisted by plasma with different proportions of Ar + N2 + CH4 gas mixture. The Ar gas flow was fixed in 4 sccm, varying only N2 and CH4 gas flows. During the thermochemical treatment, the plasma was monitored by Optical Emission Spectroscopy (OES) for the investigation of the influence of active species. After treatments, C and N concentration profile, crystalline and amorphous phases were analyzed by Nuclear Reaction (NRA). Besides tribomechanical properties of the Ti surface were studied through the nanohardness measurements and friction coefficient determination. The worn areas were evaluated by profilometry and Scanning Electronic Microscope (SEM) in order to verify the wear mechanism present in each material. It has been seen which the properties like nanohardness and friction coefficient have strong relation with luminous intensity of species of the plasma, suggesting a using of this characteristic as a parameter of process

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Metal substrates were coated by thermal spraying plasma torch, they were positioned at a distance of 4 and 5 cm from the nozzle exit of the plasma jet. The starting materials were used for deposition of tantalum oxide powder and aluminium. These two materials were mixed and ground into high-energy mill, then immersed in the torch for the production of alumina coating infused with particles of tantalum with nano and micrometric size. The spraying equipment used is a plasma torch arc not transferred, which operating in the range of 250 A and 80 V, was able to produce enough heat to ignite aluminothermic between Ta2O5 and aluminum. Upon reaching the plasma jet, the mixing powders react with the heat of the blaze, which provides sufficient energy for melting aluminum particles. This energy is transferred through mechanisms of self-propagating to the oxide, beginning a reduction reaction, which then hits on the surface of the substrate and forms a coating on which a composite is formed by a junction metal - ceramic (Ta +Al2O3). The phases and quantification of each were obtained respectively by X-ray diffraction and the Rietveld method. Morphology by scanning electron microscopy and chemical analysis by energy dispersive spectroscopy EDS. It was also performed measurements of the substrate roughness, Vickers microhardness measurements in sprays and determination of the electron temperature of the plasma jet by optical emission spectroscopy EEO. The results confirmed the expectation generated around the end product of spraying the mixture Ta2O5 + Al, both in the formation of nano-sized particles and in their final form. The electron excitation temperature was consistent with the purpose of work, in addition, the thermodynamic temperature was efficient for the reduction process of Ta2O5. The electron excitation temperature showed values of 3000, 4500 and 8000 K for flows10, 20 and 30 l / min respectively, these values were taken at the nozzle exit of the plasma jet. The thermodynamic temperature around 1200 ° C, was effective in the reduction process of Ta2O5

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Plasma diagnostics by Optical Emission Spectroscopy were performed for electrical discharge in three gas mixture respecting the combinations z N2 y Ar x H2, z N2 y Ar x O2 e z N2 y Ar x CH4, in which the indexes z and y systematically vary from 1 to 4 and x varies from 0 to 4, every one has dimension SCCM, resulting in 80 combinations. From the all obtained spectrums, the species CH (387,1 nm), N2+ (391,4 nm), Hβ (486,1 nm), Hα (656,3 nm), Ar (750,4 nm), O (777,4 nm) e O (842,6 nm) were analyzed because of their abundance and importance on the kinetic of reaction from the plasma to surface, besides their high dependences on the gases flows. Particularly interesting z, y and x combinations were chosen in order to study the influence of active species on the surface modification during the thermochemical treatment. From the mixtures N2 Ar O2 e N2 Ar CH4 were chosen three peculiar proportions which presented luminous intensity profile with unexpected maximum or minimum values, denominated as plasma anomaly. Those plasma concentrations were utilized as atmosphere of titanium treatment maintaining constant the control parameters pressure and temperature. It has been verified a relation among luminous intensity associated to N2+ and roughness, nanohardness and O atoms diffusion into the crystalline lattice of treated titanium and it has been seen which those properties becomes more intense precisely in the higher points found in the optical profile associated to the N2+ specie. Those parameters were verified for the mixture which involved O2 gas. For the mixture which involves CH4 gas, the relation was determinate by roughness, number of nitrogen and carbon atoms diffused into the titanium structure which presented direct proportionality with the luminous intensity referent to the N2+ and CH. It has been yet studied the formation of TiCN phases on the surface which presented to be essentially directly proportional to the increasing of the CH specie and inversely proportional to the increasing of the specie N2+

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The technique of surface coating using magnetron sputtering is one of the most widely used in the surface engineering, for its versatility in obtaining different films as well as in the micro / nanometric thickness control. Among the various process parameters, those related to the active species of the plasma are of the most fundamental importance in the mechanism and kinetics of deposition. In order to identify the active species of the plasma, parameters such as gas flow, pressure and density of electric power were varied during titanium coating on glass substrate. By flowing argon gas of 10, 20, 30, 40 and 50 sccm (cubic centimeters per minute) for each gas flow a sequential scan of the electric current of 0.10, 0.20, 0.30, 0.40 , 0.50 A. The maximum value of 0.50 A was chosen based both on literature data and on limitations of the equipment. The monitoring of plasma species present during the deposition was carried out in situ by the technique of optical emission spectroscopy (OES) through the spectrometer Ocean Optics USB2000 Series. For this purpose, an apparatus was developed to adapt the OES inside the plasma reactor to stay positioned closest to the target. The radiations emitted by the species were detected by an optical fiber placed behind the glass substrate and their intensities as a function of wavelength were, displayed on a monitor screen. The acquisition time for each condition of the plain parameters was related to the minima of spectral lines intensities due to the film formed on the substrate. The intensities of different emission lines of argon and titanium were then analyzed as a function of time, to determine the active species and estimate the thickness of the deposited films. After the deposition, the coated glasses thin films were characterized by optical transmittance through an infrared laser. It was found that the thickness and deposition rate determined by in situ analysis were consistent with the results obtained by laser transmittance

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The aim of this study is the labour market at Natal Metropolitan Region with emphasis in occupations and incomes that took place at the nineties. The definition of its chronological boundaries passed by verification of existence of evident socio-spatial impacts for output, occupation and income in national economy, with rebounds in all national territory, conditioned by institutional and socio-economical transformations which marked Brazilian insertion to capital flows and commodities globalization movement that took place at the cited decade. It has been shown that such impacts did not distributed themselves equally between diverse spatial levels (great regions, federate unities, municipalities) because of historical specificities in each place in terms of output structures and organization of distinct social agents. Having as its basis the Marxist perspective, it tackled theoretically occupations and incomes, transformations in labour universe occurred at world level, mainly in most urbanized areas, and following that to focus changes occurred in Brazilian society related to the search for competitive insertion in global economy during the period regarded. Special attention was gave to Natal Metropolitan Region, because it was historically a concentration area for investments, productive structure, people, occupations and incomes generated/appropriated in Rio Grande do Norte State. The basic data sources for research were the demographic Census (micro data) made by the Instituto Brasileiro de Geografia e Estatística (IBGE) intending to present the structure and the labour market dynamics, having as basis: 1) traditional indicators about labour market; 2) sectors of economic activities and 3) social positions and classes segments. One of the purposes is the demonstration that occupations and incomes keep relation with the restructuring which occurred in each specific sector during the period. Other purpose is to make explicit the factors which bear the participation of distinct segments in production or service execution that make possible the different participation in income distribution. Results are revealing the increasin precariousness in labour market, enlargement of occupations in tertiary sector and greater concentration of average incomes in the social segments which were owners of the greatest capital allowances between residents in Natal Metropolitan Region during the nineties

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The present study aimed to understand how and to what extent the electronic forró, currently hegemonic in the music market in the state of Rio Grande do Norte, establishes and maintains relations of domination in the social contexts in which it is produced, transmitted and received. Based, in significant form-content, on the writings of the first generation of theorists of the so-called Frankfurt School (Critical Theory), particularly with Theodor W. Adorno, and systematically using the contributions of the Cultural Studies (from the Centre for Contemporary Cultural Studies of Birmingham) and of the sociology of Pierre Bourdieu, this study aimed to perform, in the fertile intersection of these references, a critical possibility of interpretation of the electronic forró predominantly spread in the state of Rio Grande do Norte. To this end, aiming at a better apprehension of the so-called capital circuits/culture circuits , this study resulted from a qualitative investment of research, based on structured interviews with musicians, entrepreneurs of the sector and music consumers, as well as on the analysis of the themes contained in the official discography of the electronic forró band called Garota Safada (Shameless Girl). As a general empirical conclusion, it was possible to infer that far from the significant presence of domination or mere prevalence of oppositions, there is a relational pluralism of forms of domination and ways of resistances present in the production and consumption of electronic forró, regardless of gender, age, income, education or place of residence. However, the artifices of the cultural industry has been shown to be efficient: from large-scale businessmen to small producers enabled by the so-called open markets . The currentness of the concept of cultural industry is based on the idea that its products are offered systematically (the systematic insistence of everything to everyone) and on the notion that its production primarily meets the administrative criteria of control over the effects on the receiver (capacity of prescription of desires). Thus, the Adornian reflection on the pseudo-individualization leads to the inference that even in some of the most apparent ways of negotiation and/or refusal regarding the consumption of forró, certain behaviors of the cultural industry still prevail both in the very (re)interpretation of the forró and in the choice of other music genres also standardized, rationalized and massified. Therefore, despite the absence of cause-effect relation and the recognition of the popular capacity of re-elaboration and contestation of the media consumption, some world views prevailing in relation to the electronic forró establish or, at least, support some hegemonic ideologies, especially those concerning the life style, consumption and genre relations (fun by all means). Therefore, due the massification of certain songs, some ways of dissemination of values, beliefs and feelings are potentially experienced from the electronic forró. So, it is presumable that in the current advance of the process of semiformation (Halbbildung), the habitus of a part of the youth from the state of Rio Grande do Norte reinforces and is reinforced by the centrality of the trinomial fun, love and sex present in the songs, emphasized in some constructive practices of sense and in certain flows of social significance

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Parties are one of the most communicative languages, full of contents and symbolic meanings. The devotion to the saints is a kind of communication. In this thesis communicational processes, its languages and its flows are sought at the Saint Sebastian s party, at Alecrim neighborhood, in Natal/RN. The view is focused on the individuals and collective behaviors, in a dynamic which involves the saint s interlocutors at the party space, which supports the pre-novena, the novena and the procession. It tries to show through observation, ethnography and interviews the elements that composes the symbolic language present on the gestures, on the performances and bodies movements, on the clothing colors, as well as on what is said orally or in silence, on the spontaneous prayers or pre-elaborated ones, on the written messages that the devout addresses to the saint at the patron s festivity

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The decomposition process exercises an extensive control over the carbon cycle, affecting its availability and nutrient cycling in terrestrial ecosystems. The understanding of leaf decomposition patterns above the soil and fine roots decomposition below the soil is necessary and essential to identify and quantify more accurately the flow of energy and matter in forest systems. There is still a lack of studies and a large gap in the knowledge about what environmental variables act as local determinants over decomposition drivers. The knowledge about the decomposition process is still immature for Brazilian semiarid region. The aim of this study was to analyze the decomposition process (on leaves and fine roots) of a mixture of three native species for 12 months in a semiarid ecosystem in Northeast Brazil. We also examined whether the rate of decomposition can be explained by local environmental factors, specifically plant species richness, plant density and biomass, soil macro-arthropods species richness and abundance, amount of litterfall and fine root stock. Thirty sampling points were randomly distributed within an area of 2000 m x 500 m. To determine the decomposition rate, the litterbag technique was used and the data analysis were made with multiple regressions. There was a high degradation of dead organic matter along the experiment. Above ground plant biomass was the only environmental local factor significantly related to leaf decomposition. The density of vegetation and litter production were positively and negatively related to decay rates of fine roots, respectively. The results suggest that Caatinga spatial heterogeneity may exert strong influences over the decomposition process, taking into account the action of environmental factors related to organic matter exposure of and the consequent action of solar radiation as the decomposition process main controller in this region

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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