968 resultados para Fluxos Ópticos
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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O objetivo deste trabalho foi caracterizar e relacionar a radiação líquida com o calor latente equivalente, em mm de água, nos cultivos protegido e de campo, na cultura de pimentão. O experimento foi feito em Botucatu, SP. A estimativa do fluxo de calor latente foi feita pelo método do balanço de energia, por meio da razão de Bowen. Foram feitas medidas instantâneas da radiação líquida (Rn), dos fluxos convectivos de calor latente (LE) e sensível (H), do fluxo de calor no solo (G), e dos gradientes psicrométricos sobre a cultura. O cultivo protegido, apesar de receber menor quantidade de radiação solar global, foi mais eficiente na conversão da radiação líquida disponível em matéria seca total e na produtividade de frutos. No balanço de energia, o cultivo protegido apresentou razões G/Rn e LE/Rn inferiores e H/Rn superior, com um fluxo de calor latente, equivalente em milímetros, 45,43% menor que no cultivo no campo. Apresentou, ainda, menor quantidade de radiação líquida disponível e menores perdas de energia, mostrando-se mais eficiente no uso da água.
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Este artigo avalia os resultados do processo de reestruturação da indústria brasileira de máquinas têxteis, originado pelas reformas econômicas liberalizantes iniciadas no final dos anos 1980 e início dos 1990 e pelas medidas macroeconômicas que deram sustentação ao Plano Real, a partir de julho de 1994. Inicialmente, fazemos uma avaliação teórica das fontes do conhecimento e das formas de capacitação tecnológica nessa indústria. A seguir, expomos brevemente as principais características da indústria de máquinas têxteis em âmbito global. Posteriormente, direcionando a discussão para o caso brasileiro, apresentamos as especificidades da indústria têxtil, usuária daqueles bens, e do próprio setor de máquinas nacional. Através dos fluxos de comércio exterior do Brasil entre 1990 e 2004 e da variação do valor médio (US$ FOB/KG) desses fluxos, o artigo examina as mudanças estruturais, tecnológicas e, por conseguinte, na competitividade, que culminaram na transformação da indústria brasileira de máquinas têxteis, em termos de dimensão (escala) e escopo, e em uma nova inserção internacional, agora mais especializada e subordinada.
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With the need to deploy management and monitoring systems of natural resources in areas susceptible to environmental degradation, as is the case of semiarid regions, several works have been developed in order to find effective models and technically and economically viable. Therefore, this study aimed to estimate the daily actual evapotranspiration (ETr) through the application of the Surface Energy Balance Algorithm for Land (SEBAL), from remote sensing products, in a semiarid region, Seridó of the Rio Grande do Norte, and do the validation of these estimates using ETr values obtained by the Penman-Monteith (standard method of the Food and Agriculture Organization-FAO). The SEBAL is based on energy balance method, which allows obtaining the vertical latent heat flux (LE) with orbital images and, consequently, of the evapotranspiration through the difference of flows, also vertical, of heat in the soil (G), sensitive heat (H) and radiation balance (Rn). The study area includes the surrounding areas of the Dourado reservoir, located in the Currais Novos/RN city. For the implementation of the algorithm were used five images TM/Landsat-5. The work was divided in three chapters in order to facilitate a better discussion of each part of the SEBAL processing, distributed as follows: first chapter addressing the spatio-temporal variability of the biophysical variables; second chapter dealing with spatio-temporal distribution of instant and daily radiation balance; and the third chapter discussing the heart of the work, the daily actual evapotranspiration estimation and the validation than to the study area
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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This piece focuses on the issue of media in the contemporary context, taking for its object the sociocultural phenomenon of mediatization‟, understood as the dilution of media culture in the everyday life, according to the perspective from Fausto Neto (2008) e Sodré (2002). This phenomenon is viewed from the angle of reception, that is, one that considers the individuals as pro-actives in this dynamic. The media culture is perceived as a fundamental element in the process of social structuring, and also is taken as a symbolic arm of great importance for the elaboration of the notion of reality as it interferes with the flow of information. Thus, we emphasize the process of symbolic consumption that we do with media content (Canclini, 1999), through a dynamic of appropriation and reframing, given from the interweaving of the meanings proposed with extra-media elements, recaptured from the perspective of mediations, by Barbero (2006), which concerns the articulation of the contents we appropriate from media with interactions from other social practices. We also consider the dimension of memory according to Sarlo (2007) and Halbwachs (2004) in order to, through speeches made in its scope, reach empirically the phenomenon of mediatization‟, and overlapping it, the media consumption on a specific theme, "science". Nevertheless, in terms of field work, we use the technique of in-depth interviews, so that the speech of our interviewers was our corpus. Through their narratives, speeches considered by us as memory-related, we visualize the dynamics of media consumption on given topic. At the level of conclusions, we realize that mediatization‟ as a phenomenon occurred, but its flows and orders showed discontinuities and pluralities not initially conceived; regarding the consumption of science through media, we see hybrid perceptions by our respondents, that is, one that include both elements aligned with the positivist conception of science - which we consider to be the view of science proposed by the media and elements that would contradict this view
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
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There is nowadays a growing demand for located cooling and stabilization in optical and electronic devices, haul of portable systems of cooling that they allow a larger independence in several activities. The modules of thermoelectrical cooling are bombs of heat that use efect Peltier, that consists of the production of a temperature gradient when an electric current is applied to a thermoelectrical pair formed by two diferent drivers. That efect is part of a class of thermoelectrical efcts that it is typical of junctions among electric drivers. The modules are manufactured with semiconductors. The used is the bismuth telluride Bi2Te3, arranged in a periodic sequence. In this sense the idea appeared of doing an analysis of a system that obeys the sequence of Fibonacci. The sequence of Fibonacci has connections with the golden proportion, could be found in the reproductive study of the bees, in the behavior of the light and of the atoms, as well as in the growth of plants and in the study of galaxies, among many other applications. An apparatus unidimensional was set up with the objective of investigating the thermal behavior of a module that obeys it a rule of growth of the type Fibonacci. The results demonstrate that the modules that possess periodic arrangement are more eficient
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n this master s dissertation a Kerr Magneto Optic s magnetometer effect was set up to do characterization of samples type films fine and ultra thin, these samples will be grown after the implementation of the sputtering technique at the magnetism laboratory of of this department. In this work a cooled electromagnet was also built the water and that it reaches close values to 10kOe with a gap of 22 mm including an area of uniform field of 25mm of diameter. The first chapter treats of the construction of this electromagnet from its dimensioning to the operation tests that involve measures of reached maximum field and temperature of the reels when operated during one hour. The second chapter is dedicated to the revision of the magnetism and the magnetization processes as well as it presents a theoretical base regarding the magnetic energies found in films and magnetic multilayer. In the sequence, the third chapter, is especially dedicated the description of the effects magneto opticians the effect kerr in the longitudinal, traverse and polar configurations, using for so much only the classic approach of the electromagnetism and the coefficients of Fresnel. Distinguished the two areas of observation of the effect regarding thickness of the film. The constructive aspects of the experimental apparatus as well as the details of its operation are explained at the room surrender, also presenting the preliminary results of the measures made in one serializes of permalloy films and concluding with the results of the characterization of the first films of iron and permalloy grown here at the theoretical and experimental physics department at UFRN
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The physical properties and the excitations spectrum in oxides and semiconductors materials are presented in this work, whose the first part presents a study on the confinement of optical phonons in artificial systems based on III-V nitrides, grown in periodic and quasiperiodic forms. The second part of this work describes the Ab initio calculations which were carried out to obtain the optoeletronic properties of Calcium Oxide (CaO) and Calcium Carbonate (CaCO3) crystals. For periodic and quasi-periodic superlattices, we present some dynamical properties related to confined optical phonons (bulk and surface), obtained through simple theories, such as the dielectric continuous model, and using techniques such as the transfer-matrix method. The localization character of confined optical phonon modes, the magnitude of the bands in the spectrum and the power laws of these structures are presented as functions of the generation number of sequence. The ab initio calculations have been carried out using the CASTEP software (Cambridge Total Sequential Energy Package), and they were based on ultrasoft-like pseudopotentials and Density Functional Theory (DFT). Two di®erent geometry optimizations have been e®ectuated for CaO crystals and CaCO3 polymorphs, according to LDA (local density approximation) and GGA (generalized gradient approximation) approaches, determining several properties, e. g. lattice parameters, bond length, electrons density, energy band structures, electrons density of states, e®ective masses and optical properties, such as dielectric constant, absorption, re°ectivity, conductivity and refractive index. Those results were employed to investigate the confinement of excitons in spherical Si@CaCO3 and CaCO3@SiO2 quantum dots and in calcium carbonate nanoparticles, and were also employed in investigations of the photoluminescence spectra of CaCO3 crystal
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Background: Obesity may affect the respiratory system, causing changes in respiratory function and in the pulmonary volumes and flows. Objectives: To evaluate the influence of obesity in the movement of thoracoabdominal complex at rest and during maximal voluntary ventilation (MVV), and the contribution between the different compartments of this complex and the volume changes of chest wall between obese and non-obese patients. Materials and Methods: We studied 16 patients divided into two groups: the obese group (n = 8) and group non-obese (n = 8). The two groups were homogeneous in terms of spirometric characteristics (FVC mean: 4.97 ± 0.6 L - 92.91 ± 10.17% predicted, and 4.52 ± 0.6 L - 93.59 ± 8.05%), age 25.6 ± 5.0 and 26.8 ± 4.9 years, in non-obese and obese respectively. BMI was 24.93 ± 3.0 and 39.18 ± 4.3 kg/m2 in the groups investigated. All subjects performed breathing calm and slow and maneuver MVV, during registration for optoelectronic plethysmography. Statistical analysis: we used the unpaired t test and Mann-Whitney. Results: Obese individuals had a lower percentage contribution of the rib cage abdominal (RCa) during breathing at rest and VVM. The variation of end expiratory (EELV) and end inspiratory (EILV) lung volumes were lower in obese subjects. It has been found asynchrony and higher distortion between compartments of thoracoabdominal complex in obese subjects when compared to non-obese. Conclusions: Central obesity impairs the ventilation lung, reducing to adaptation efforts and increasing the ventilatory work
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This work treats about the speeches that produced the crisis of symbols of Ceará, researching on matters and ways of expression of space between 1950s and 1970s. Therefore, we search discursive practices that since the end of nineteenth century built the identity of Ceará and in the middle of twentieth century produced the crisis of modes of seeing and telling the space in front of enunciations of the national modernization, especially with the emergence of politics by SUDENE to the Northeast, the progressive actions by Catholic Church, the defense of tradition by regional literature of union of Ceará Clã. The contradictions between the glorification and fear the modernization of Brazil produced on the space speeches that his identity would be fractured, that the old symbols of drought, cangaço, mysticism and colonels declined. Among analyzed speeches, we centered the analysis of Trilogia da Maldição formed of novels O Dragão, of 1964, Os Verdes Abutres da Colina and João Pinto de Maria: a biografia de um louco by José Alcides Pinto. In this novel, the enunciation of the crisis of symbologies about the space produced another aesthetic, the allegory, which, mixed with the mystical and melancholy, in search of ways to restore the language of the old themes Ceará, drop of Ceará the same stigma of anti-modern space, where the images of delay changed icons of a fractured identity in front of the modern streams, where the word was transformed in the dimension precarious and redeemer of the tradition, of old, of nature, of the plenitude of senses. In Jose Alcides, the colonel returns as the origin of the lost space, the drought is the revolt of God against the devil place, the apocalypse, the end imminent threat to the village, signs that fantastic, however, are in dialogue with the settings space and time in which they were produced
A Produção do Flagelo : a re-produção do espaço social da seca na cidade de Mossoró (1877-1903-1915)
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The great droughts re- produced spaces in the city of Mossoró / RN in the end of the nineteenth century to the beginning of the twentieth century. Its dimension exceeds the climatic effects becoming social locus when advances over the political and economic sectors, social and cultural of the North / Northeast Brazilian societies during that period. This way, analyzing the re-production of social space in episodes of Mossoró‟s droughts is our toil. So try to reveal each segment, route and aspect of production of space in its size and interface between the perceived, conceived and lived, and subjects related to it - refugees, population and authorities - during the droughts of 1877, 1903 and 1915 within Mossoró city. Therefore, issues such as the constitution and representation of the city and social space in the terrifying experience of the drought of 1877, the production of fixed objects and flows of the urban web through of migrant labor, attempts to control, discipline and spatial planning and ways to resistance to these charges in daily sphere are key issues addressed in this work. For this we use diverse sources as minutes of the city council, reports from provincial presidents, media, memory books and others that sustain us in building our narrative and problematic. This way, the spatial production of Mossoró‟s droughts reveals itself in the field of relations and political-economic transformations and sociocultural, inextricably, that shapes and mobilizes your own social space
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Recently, genetically encoded optical indicators have emerged as noninvasive tools of high spatial and temporal resolution utilized to monitor the activity of individual neurons and specific neuronal populations. The increasing number of new optogenetic indicators, together with the absence of comparisons under identical conditions, has generated difficulty in choosing the most appropriate protein, depending on the experimental design. Therefore, the purpose of our study was to compare three recently developed reporter proteins: the calcium indicators GCaMP3 and R-GECO1, and the voltage indicator VSFP butterfly1.2. These probes were expressed in hippocampal neurons in culture, which were subjected to patchclamp recordings and optical imaging. The three groups (each one expressing a protein) exhibited similar values of membrane potential (in mV, GCaMP3: -56 ±8.0, R-GECO1: -57 ±2.5; VSFP: -60 ±3.9, p = 0.86); however, the group of neurons expressing VSFP showed a lower average of input resistance than the other groups (in Mohms, GCaMP3: 161 ±18.3; GECO1-R: 128 ±15.3; VSFP: 94 ±14.0, p = 0.02). Each neuron was submitted to current injections at different frequencies (10 Hz, 5 Hz, 3 Hz, 1.5 Hz, and 0.7 Hz) and their fluorescence responses were recorded in time. In our study, only 26.7% (4/15) of the neurons expressing VSFP showed detectable fluorescence signal in response to action potentials (APs). The average signal-to-noise ratio (SNR) obtained in response to five spikes (at 10 Hz) was small (1.3 ± 0.21), however the rapid kinetics of the VSFP allowed discrimination of APs as individual peaks, with detection of 53% of the evoked APs. Frequencies below 5 Hz and subthreshold signals were undetectable due to high noise. On the other hand, calcium indicators showed the greatest change in fluorescence following the same protocol (five APs at 10 Hz). Among the GCaMP3 expressing neurons, 80% (8/10) exhibited signal, with an average SNR value of 21 ±6.69 (soma), while for the R-GECO1 neurons, 50% (2/4) of the neurons had signal, with a mean SNR value of 52 ±19.7 (soma). For protocols at 10 Hz, 54% of the evoked APs were detected with GCaMP3 and 85% with R-GECO1. APs were detectable in all the analyzed frequencies and fluorescence signals were detected from subthreshold depolarizations as well. Because GCaMP3 is the most likely to yield fluorescence signal and with high SNR, some experiments were performed only with this probe. We demonstrate that GCaMP3 is effective in detecting synaptic inputs (involving Ca2+ influx), with high spatial and temporal resolution. Differences were also observed between the SNR values resulting from evoked APs, compared to spontaneous APs. In recordings of groups of cells, GCaMP3 showed clear discrimination between activated and silent cells, and reveals itself as a potential tool in studies of neuronal synchronization. Thus, our results indicate that the presently available calcium indicators allow detailed studies on neuronal communication, ranging from individual dendritic spines to the investigation of events of synchrony in neuronal networks genetically defined. In contrast, studies employing VSFPs represent a promising technology for monitoring neural activity and, although still to be improved, they may become more appropriate than calcium indicators, since neurons work on a time scale faster than events of calcium may foresee
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O presente trabalho objetivou a avaliação da remoção de matéria orgânica carbonácea e nitrogenada, bem como a determinação do fluxo crítico, em biorreator de membranas, com zona pré-anóxica, tratando águas residuárias industriais da produção de aminoácidos. O reator foi operado sob carga orgânica volumétrica de 1,91 kg.DQO.m-3.d-1 e 0,18 kg.NTK.m-3.d-1; a recirculação do reator aeróbio para o reator anóxico foi de quatro vezes a vazão afluente. O reator apresentou médias de remoção de DQO, NTK e NT de 97, 98 e 92%, respectivamente. O sistema de ultrafiltração foi testado em vários fluxos entre 25 e 37 L.m-2.h-1 e determinou-se o fluxo crítico de 28 L.m-2.h-1 quando operado com 11,4 g.L-1 de SST e 35 dias de tempo de retenção celular. Os resultados mostraram que houve viabilidade técnica no uso de biorreator de membranas para remoção de matéria orgânica de águas residuárias industriais da produção de aminoácidos.