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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
251

Sobre seÃÃes cÃnicas / On conic sections

Josà Adriano dos Santos Oliveira 18 June 2015 (has links)
CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / O estudo realizado nesta dissertaÃÃo, busca apresentar as seccÃes cÃnicas, dando Ãnfase a uma abordagem por meio de uma geometria sintÃtica e elementar, onde o trabalho à desenvolvido da seguinte forma: inicia-se com uma abordagem histÃrica, assim como a sua relaÃÃo com o cone circular; em seguida, à feito um estudo sintÃtico sobre as cÃnicas, exclusivamente, no plano; apresenta-se algumas superfÃcies quÃdricas; a equaÃÃo geral do segundo grau à apresentada como uma representaÃÃo algÃbrica de uma cÃnica e sÃo mostradas diversas situaÃÃes, onde as cÃnicas surgem de forma, curiosamente, natural, alÃm das inÃmeras aplicaÃÃes prÃticas em diversas Ãreas do conhecimento. / The study in this dissertation, seeks to present the conic sections, emphasizing an approach by means of a synthetic and elementary geometry, where the work is carried out as follows: begins with a historical approach, as well as their relationship with the circular cone; then itâs done a synthetic study on the conical exclusively on the plan; It presents some quadric surfaces; the general equation of the second degree is presented as an algebraic representation of a conic and are shown several situations where the conical arise so, curiously, natural, in addition to numerous practical applications in various fields of knowledge.
252

Susceptibilidade do piloro de Bombyx mori (Lepidoptera, bombycidae) ao bombyx mori multiple nucleopolyhedrovirus

Baggio, Mayarha Patricia Dequigiovanni 01 August 2013 (has links)
Made available in DSpace on 2017-07-10T14:17:04Z (GMT). No. of bitstreams: 1 Mayaha.pdf: 4416602 bytes, checksum: 8b663982eaff70076dc570733618b841 (MD5) Previous issue date: 2013-08-01 / Bombyx mori multiple nucleopolyedrovirus (BmMNPV) is an entomopathogenic virus of the Baculoviridaefamily, genera Alphabaculovirus, which infects the silkworm (Bombyx Mori) and causes nuclear polyhedrosis disease. This virus is poliorganotrophic and a series of tissues are known as targets; however, literature does not present information in regards to the pylorus, segment of the hindgut, present in the transition with the midgut and responsible for regulating the passage of food towards the ileum. The organ is, thus, of fundamental importance in the ending of the digestive process, affecting the insect s metabolic balance and, the present study sought to analyze its susceptibility and cytopathology in regards to BmMNPV, geographic isolate of Paraná, Brazil. Moreover, due to the complexity of this segment, its general morphology will also be analyzed. In order to do so, hybrid B.mori caterpillars at 5º instar were inoculated experimentally with a viral suspension of BmMNPV. On different day post-inoculation (dpi), from 2º to 9ºdpi, segments of the intestine, containing the pylorus, with its subdivisions (posterior interstitial ring, pyloric cone and pyloric valve), were dissected, following the routine histological processing for paraffin wax blockage and dyes in haematoxylin and eosin, for general morphology analysis, and in modified Azan staining, for cytopathology. Segments also processed to form scanning electronic microscope for analized of morphological details. So the pylorus general morphology the caterpillars of B. mori, was similar to that observed in other insects. The cytopathology showed that the anterior area of the posterior interstitial ring is a secondary target of infection for the BmMNPV, after 5º dpi, and its infectious cycle is similar to that described in literature. In the hypertrophic nucleus one there the formation of viroplasm, place for production of enveloped nucleocapsids or virions, following the formation and development of the polyhedra. Later on, cytolysis occurred, promoting the liberation of polyhedra and the spreading of the disease, mainly in the B. mori creation sheds. The posterior area of the posterior interstitial ring, the pyloric cone and the pyloric valve did not reveal any traces of infection by BmMNPV and, thus, resistance mechanisms involving genetic factors could be acting. The knowledge obtained from this work will contribute in the establishment of the infectious cycle of this important entomopathogenic virus, which may lead to an epizootic that can negatively affect the whole productive chain of silk / Bombyx mori multiple nucleopolyedrovirus (BmMNPV) é um vírus entomopatogênico da família Baculoviridae, gênero Alphabaculovirus, que infecta o bicho-da-seda (Bombyx mori) e causa a doença poliedrose nuclear. Este vírus é poliorganotrófico e uma série de tecidos são conhecidos como alvos; contudo, a literatura não apresenta informações sobre o piloro, segmento do intestino posterior, presente na transição com o médio e responsável pela regulação da passagem do alimento em direção ao ileo. O órgão é assim de fundamental importância na finalização do processo digestório, afetando o equilíbrio metabólico do inseto e, o presente estudo objetivou analisar sua susceptibilidade e citopatologia frente ao BmMNPV, isolado geográfico do Paraná, Brasil. Ainda, devido a complexidade deste segmento, também será analisada sua morfologia geral. Para tanto, lagartas híbridas de B. mori no 5° instar foram inoculadas experimentalmente com uma suspensão viral de BmMNPV. Em diferentes dias pós-inoculação (dpi), do 2° ao 9° dpi, segmentos do intestino, contendo o piloro, com suas subdivisões (anel intersticial posterior, cone pilórico e válvula pilórica), foram dissecados, seguindo o processamento histológico de rotina para emblocamento em parafina e colorações em hematoxina e eosina, na análise da morfologia geral, e em Azan modificado, para a citopatologia. Segmentos também foram processados em microscopia eletrônica de varredura para análise de detalhes morfológicos. Assim, a morfologia geral do piloro das lagartas da B. mori foi semelhante à observada em outros insetos. A citopatologia mostrou que a área anterior do anel intersticial posterior é alvo secundário de infecção pelo BmMNPV, a partir do 5° dpi, e seu ciclo infeccioso é semelhante ao descrito em literatura. No núcleo hipertrófico houve a formação do viroplasma, local de produção dos nucleocapsídeos envelopados ou virions, seguindo a formação e o desenvolvimento dos poliedros. Posteriormente, ocorreu a citólise, promovendo a liberação dos poliedros e disseminação da doença, principalmente nos barracões de criação de B. mori. A área posterior do anel intersticial posterior, o cone pilórico e a válvula pilórica não revelaram quaisquer indícios de infecção pelo BmMNPV e, desta forma, mecanismos de resistência envolvendo fatores genéticos poderiam estar atuando. Os conhecimentos obtidos irão contribuir no estabelecimento do ciclo infeccioso deste importante vírus entomopatogênico, cuja conseqüência de uma epizootia pode afetar negativamente toda a cadeia produtiva da seda
253

Interpreting density enhancement of coronal mass ejections

Smith, Kellen January 2019 (has links)
Coronal mass ejections (CMEs) are some of the extraterrestrialevents most impactful to earth. Eorts to model and predict theireects have seen new possibilities in the two most recent decades dueto multiple new spacecrafts providing a wider range of data than everbefore. Models of these events suer from a number of inaccuracies,one of them being the density ratio between the CME and the ambientsolar wind. Since the arrival time for potentially harmful disturbancespredicted by models has been proved to be highly sensitive to thisparameter we therefore take care to set it as accurately as possible.Traditionally this value is either set to a default, justied by denitionand theory, or set to the density ratio between the bulk if the ejectedgas and the surrounding medium. A proposition has been made tomeasure density enhancement dierently, using a reference point at theshock wave preceding the CME for each event. This method strives toimprove arrival time predictions and was in this paper tested for onecoronal mass ejection event. Two runs if the model WSA-ENLIL+Conewas made; one with the default value of density enhancement, onewith a value determined through the revised method using coronographdata. Running the model with the revised value improved the predictedarrival time by moving it forwards in time by 4h, which was still tooearly. Other input data into the model run was then discussed as apossible cause of the remaining inaccuracy. / Koronamassutkastningar är ett av solfenomenen som påverkar jorden mest.Nya rymdfarkoster med instrument som satts i arbete de senaste två decenniernahar gett data som gjort det möjligt att modellera och förutse dessaevent till en högre precision än någonsin. Alla dessa modeller lider av någonform av felkälla, en av vilka är kvoten mellan densitet för massutkastningenoch den omgivande miljön. Eftersom förutsedda ankomsstider för potentielltskadliga störningar har visat sig vara särskilt känsliga för denna parameterså tar vi särskild hänsyn till att ange den så precist som möjligt. Vanligtvissätts detta värde till ett fast standardvärde, som anges av dess denitionoch bakomliggande teori, eller till kvoten mellan utkastningens bulk ochomgivningen. Ett förslag har dock lagts fram om att omdeniera parametern.Denna metod strävar efter att förbättra förutsedda ankomsttider ochhar i denna text testats för en koronamassutkastning. Två körningar avmodellen WSA-ENLIL+Cone gjordes; en med defaultvärdet för densitetsratiot,en med värdet satt genom mätning av empirisk cononagrafdata enligtden föreslagna metoden. Att köra modellen med den nya parametern förbättrade den förutsedda ankomsttiden genom att ytta den framåt i tidenmed 4 timmar, vilket fortfarande är för tidigt. Andra inputdata i modellendiskuterades då som möjliga orsaker till den återstående diskrepansen.
254

Study of the spatio-temporal dynamics of guidance receptors during commissural axon navigation in the spinal cord / Étude de la dynamique spatio-temporelle des récepteurs de guidage au cours de la navigation des axones commissuraux de la moelle épinière

Pignata, Aurora 10 December 2018 (has links)
Les commissures forment un ensemble de connexions nerveuses assurant la communication entre les neurones de chaque hémi partie du système nerveux central des bilatériens. Au cours du développement embryonnaire, les axones des neurones commissuraux sont guidés au travers de la ligne médiane délimitant ces deux parties. Plusieurs sources de signaux de guidage attractifs et répulsifs agissent de concert pour organiser les trajectoires de ces axones. Dans la moelle épinière, les axones commissuraux traversent la ligne médiane dans un territoire ventral, la plaque du plancher (PP). Au cours de la traversée de la PP, ils acquièrent une sensibilité à des signaux répulsifs exprimés par ce territoire qui leur empêchent de rebrousser le chemin et qui les poussent hors de la PP. Plusieurs couples ligands/récepteurs médient ces forces répulsives mais les mécanismes qui sous-tendent l'acquisition de la sensibilité aux signaux répulsifs restent encore peu connus. Par exemple on ignore si les axons se sensibilisent à tous les signaux répulsifs en même temps, quand précisément ce switch de réponse se fait, et les contributions précises de chacun de ces signaux. Une spécificité fonctionnelle est suggérée par l'analyse des phénotypes d'invalidation des gènes codant pour ces récepteurs chez la souris ou encore par des manipulations d'expression chez l'embryon de poulet. L'objectif de mes travaux de thèse a été de tester l'hypothèse selon laquelle la génération de spécificités fonctionnelles pourrait résulter de contrôles précis et distincts de la dynamique spatiale et temporelle des récepteurs de guidage à la surface du cône de croissance. J'ai tout d'abord développé un dispositif de vidéomicroscopie adapté à l'enregistrement de cônes de croissance accomplissant la traversée de la PP, sur des moelles épinières en configuration de «livre ouvert». Afin de visualiser l'adressage à la surface du cône de croissance, j'ai exploité une forme de GFP sensible au pH, dont les propriétés de fluorescence à pH neutre permettent un suivi spécifique du pool de surface des protéines (Nawabi et al., 2010; Delloye-Bourgeois et al, 2014). J'ai utilisé ce paradigme pour comparer la dynamique temporelle de 4 récepteurs médiant les réponses aux divers signaux répulsifs de la PP: Nrp2, Robo1, Robo2 et PlxnA1. Les vecteurs d'expression de ces formes pHLuo de récepteurs ont été introduits dans les neurones commissuraux de la moelle épinière d'embryon de poulet par électroporation in ovo. Par des approches de microscopie à super-résolution sur les livres-ouverts, j'ai aussi étudié la distribution spatiale des récepteurs répulsifs à la surface des cônes de croissances au cours de la traversée. L'ensemble de ces expériences a pu démontrer que les récepteurs sont adressés à la membrane à différents temps de la navigation de la PP et occupent, de plus, des domaines distincts du cône de croissance. J'ai ensuite adapté la technique d'électroporation à la moelle épinière d'embryon de souris. Ces expériences ont montré que les séquences temporelles observées chez le poulet sont conservées chez la souris. J'ai également réintroduit le récepteur Robo1 dans une lignée de souris présentant une invalidation des récepteurs Robo1/2 et montré que l'altération de la traversée de la PP caractéristique de cette lignée est abolie dans la population d'axones capables d'adresser le récepteur Robo1 à la membrane. Au final, mes résultats démontrent que les axones commissuraux ne sont pas sensibilisés aux signaux répulsifs par la mise en œuvre d'un programme général. Au contraire, les récepteurs de guidage possèdent des profils de dynamiques temporelles spécifiques, et des domaines de distribution distincts dans le cône de croissance. Le contrôle de la dynamique d'adressage représente ainsi un mécanisme permettant de discriminer des signaux concomitants, en les fonctionnalisant à différents temps de la navigation de la moelle épinière / During embryonic development, commissural axons are guided through the midline, crossing from one side of the CNS to the other one at specific time points and positions to project onto contralateral neurons. Several sources of attractive cues regulate their navigation. In addition, repulsive forces act at different steps to keep the axons along their path. In the developing spinal cord, commissural axons cross the midline in a ventral territory, the floor plate (FP). Commissural axons gain sensitivity to repellents present in the FP after their crossing. The setting of these novel properties is necessary for preventing the axons to cross back and also for pushing them towards FP exit. Various ligand/receptor couples have been reported to mediate these repulsive forces. Whether commissural axons gain response to all the repulsive cues at the same time is not known. Whether these repulsive cascades have specific functions is suggested by different outcome of their invalidation in mouse models, but how are set these differences also remains unknown. We hypothesized that the generation of functional specificities could be achieved though specific controls of the spatial and temporal dynamics of guidance receptors at the growth cone surface. During my PhD, I developed a set up for time-lapse imaging of “open book” spinal cords, to monitor the dynamics of guidance receptors in axons experiencing native guidance decisions across the midline. To visualize their cell surface sorting, receptors were fused to the pH-sensitive GFP, pHLuorin, whose fluorescence at neutral pH reports membrane protein pools (Nawabi et al, 2010; Delloye-Bourgeois et al, 2014), and were expressed in spinal commissural neurons through in ovo electroporation. This paradigm revealed striking differences in the temporal dynamics of Nrp2, Robo1, Robo2 and PlexinA1, the receptors known to mediate the responsiveness to the major midline repellents referenced in vertebrates: Slit-Ns, Slit-Cs and Semaphorin3B. Moreover, using super-resolution microscopy, I could evidence that PlexinA1 and Robo1 are sorted in distinct subdomains of commissural growth cones navigating the floor plate. I also introduced the pHLuo-tagged receptors in the mouse embryo. These experiments showed that the temporal sequences established in the chick are conserved in the mouse, and that FP crossing in Robo1/2 mutant embryos was rescued in growth cones that could achieve cell surface sorting of Robo1. Thus, my results show that guidance receptors for midline repellents have highly specific spatial and temporal dynamics. The generation of a temporal sequences of cell surface sorting thus represents a mechanism whereby commissural growth cones discriminate concomitant signals by functionalizing them at different timing of their spinal cord navigation
255

Experimental Study Of Large Angle Blunt Cone With Telescopic Aerospike Flying At Hypersonic Mach Numbers

Srinath, S 12 1900 (has links)
The emerging and competitive environment in the space technology requires the improvements in the capability of aerodynamic vehicles. This leads to the analysis in drag reduction of the vehicle along with the minimized heat transfer rate. Using forward facing solid aerospike is the simplest way among the existing drag reduction methodologies for hypersonic blunt cone bodies. But the flow oscillations associated with this aerospike makes it difficult to implement. When analyzing this flow, it can be understood that this oscillating flow can be compared to conical cavity flow. Therefore in the spiked flows, it is decided to implement the technique used in reducing the flow oscillation of the cavities. Based on this method the shallow conical cavity flow generated by the aerospike fixed ahead of a 120o blunt cone body is fissured as multiple cavities by so many disks formed from 10o cone. Now the deep conical cavities had the length to mean depth ratio of unity; this suppresses the unnecessary oscillations of the shallow cavity. The total length of the telescopic aerospike is fixed as 100mm. And one another conical tip plain aerospike of same length is designed for comparing the telescopic spike’s performance at hypersonic flow Mach numbers of 5.75 and 7.9. A three component force balance system capable of measuring drag, lift and pitching moment is designed and mounted internally into the skirt of the model. Drag measurement is done for without spike, conical tip plain spiked and telescopic spiked blunt cone body. The three configurations are tested at different angles of attack from 0 to 10 degree with a step of 2. A discrete iterative deconvolution methodology is implemented in this research work for obtaining the clean drag history from the noisy drag accelerometer signal. The drag results showed the drag reduction when compared to the without spike blunt cone body. When comparing to the plain spiked, the telescopic spiked blunt cone body has lesser drag at higher angles of attack. Heat transfer measurements are done over the blunt cone surface using the Platinum thin film gauges formed over the Macor substrate. These results and the flow visualization give better understanding of the flow and the heat flux rate caused by the flow. The enhancement in the heat flux rate over the blunt cone surface is due to the shock interaction. And in recirculation region the heat flux rate is very much lesser when compared to without spike blunt cone body. It is observed that the shock interaction in the windward side is coming closer towards the nose of the blunt cone as the angle of attack increases and the oscillation of the oblique shock also decreases. Schlieren visualization showed that there is dispersion in the oblique shock, particularly in the leeward side. In the telescopic spike there are multiple shocks generated from each and every disk which coalesces together to form a single oblique shock. And the effect of the shock generated by the telescopic spike is stronger than the effect of the shock generated by the conical tip plain spike.
256

Statinio zondavimo rodiklių santykio naudojimas Lietuvos moreninių gruntų pavadinimui nustatyti / Using CTP parameters ratio to determine the name of Lithuanian till soils

Tranizaitė, Toma 17 June 2013 (has links)
Baigiamajame magistriniame darbe susietas Lietuvos moreninių molinių gruntų pavadinimas (pagal LST EN ISO 14688-2:2006) su statinio zondavimo (CPTu) duomenimis. Darbą sudaro teorinė ir praktinė dalys. Teorinėje dalyje aptartos sudarytos gruntų klasifikacijos pagal CPT ir CPTu duomenis, aprašytos tyrime naudojamų gruntų vietovės inžinerinės-geologinės sąlygos bei sudaryta tyrimo metodologija, kurioje pateiktos formulės CPT ir CPTu rodiklių santykio apskaičiavimui, aprašomas grunto pavadinimo nustatymas pagal granuliometrinę sudėtį bei taikomas metodas molinių gruntų granuliometrinės sudėties nustatymui. Trumpai aprašomi tyrime taikyti principai. Praktinėje dalyje išsamiai aprašyti ir išanalizuoti skaičiavimuose naudojami duomenys, surastos priklausomybės, sudaryta gruntų pavadinimo nustatymo schema bei įvertinta gruntų klasifikacija pagal aptartus 4 metodus. Pateiktos išvados ir siūlymai tolimesniam darbui bei gautų rezultatų patikslinimui. Darbą sudaro 8 pagrindinės dalys: įvadas, atliktų darbų apžvalga, vietovės inžierinės-geologinės sąlygos, tyrimo metodologija, tyrimo rezultatai, išvados, literatūros sąrašas ir priedai. Darbo apimtis – 50 p. teksto be priedų, 59 p. priedų, 20 literatūros šaltiniai, 30 pav. ir 5 lentelės. / The present Master Thesis forms a link between the names of the Lithuanian moraine argillaceous soils (according to LST EN ISO 14688-2:2006) and the data of the cone penetration test (CPTu). The paper consists of a theoretical part and a research. The theoretical part is devoted to discussing formulated soil classifications according to the data of CPT and CPTu, describing the engineering/ geological conditions of the soil locations investigated in the research and presenting the research methods. The research methods include the formulas for calculating the CPT and CPTu indicator ratio, description of determining the soil name according to the particle size distribution and application of the method for determining the particle size distribution of argillaceous soils. The principles employed in the research are also briefly described. The research includes a detailed description and analysis of the data used in the calculations and the discovered dependencies, the formulated soil name determination plan and the soil classification assessed according to the discussed four methods. At the end of the paper, conclusions and recommendations are given for further work and specification of the received results. The study consists of the following eight parts: introduction, review of the earlier studies, engineering/ geological conditions of the location, research methods, research results, conclusions, references and annexes. The paper consists of 50 pages without annexes, 59 pages... [to full text]
257

"Que América Latina se sincere" : uma análise antropológica das políticas e poéticas do atavismo negro em face às ações afirmativas e às reparações no Cone Sul

Lopez, Laura Cecilia January 2009 (has links)
Esta tese se propõe a examinar os itinerários e as perspectivas das mobilizações políticas negras contemporâneas no Cone Sul, com ênfase nas redes de ativistas que atuam em Porto Alegre (Brasil), Montevidéu (Uruguai) e Buenos Aires (Argentina), frente aos atuais desafios da implementação de políticas públicas com enfoque étnico-racial. A partir do aporte da perspectiva antropológica que orienta uma aproximação da "experiência de perto" dos sujeitos, detenho-me no protagonismo de ativistas em face aos desdobramentos de políticas públicas e ações reparatórias. O trabalho se insere nas discussões sobre a questão multicultural e o multiculturalismo nas sociedades latino-americanas. Interrogo como sujeitos tidos e vistos como minoritários, que não foram contemplados no projeto de "igualdade" preconizado pelos ideais eurocêntricos de nação moderna instituído nos países da região, vêm a interferir na esfera pública, ao passo que evidenciam noções e projetos de nação em disputa. O trabalho busca compreender os movimentos afro-latino-americanos através das formas com que ocupam a esfera pública e manejam noções e projetos de sociedade multicultural. Analiso as conexões entre o "nacional" e o transnacional a partir das políticas raciais e das militâncias negras, bem como da experiência com identificações étnicas afro-diaspóricas. Parto das configurações locais das militâncias negras contemporâneas que se expandem e modelam numa arena trans-local e diaspórica e se projetam para o espaço da nação. Proponho-me delinear cartografias da militância negra nas três cidades contempladas nesta tese a partir de percorrer experiências múltiplas de engajamento na esfera pública. E por fim, examino: i) os modos como as redes de militância são mobilizadas na construção de demandas e ii) as disputas por políticas públicas em torno da saúde e da educação com perspectiva étnico-racial e de gênero, analisando as complexas e múltiplas relações entre atores sociais envolvidos no processo de tradução de resistências locais em problemas que irrompem as arenas públicas e disputam por sua legitimação perante agentes e instituições com condições para disseminálos. / This thesis aims at analyzing the itineraries and perspectives of the contemporary black movement political mobilization in the Southern Cone, focusing on the network of activists of Porto Alegre (Brazil), Montevideo (Uruguay) and Buenos Aires (Argentina), before the current challenges introduced by the implementation of ethnical-racial focused public policies. From an anthropological viewpoint that emphasizes a personal approach to the subjects' experiences, I concentrate on the activists' actions in the face of the consequences of public policies and reparatory actions. In the context of the debates on multicultural issues and multiculralisms in Latin-American societies, I will try to understand how those subjects that belong to the so-called minority groups, which, in turn, went unacknowledged by the European centered ideal of "equality" in the regional modern nation-states, impinge on the public sphere while they evidence notions and national projects that collide with each other. I, therefore, aim at understanding the political expression of African Latin- American movements through their uses of space in the public spheres and of dealing with the notions and projects of a multicultural society. I analyze the connections between the national and transnational from the viewpoint of racial policies, black militancies and the identification with the African diasporas. I begin by mapping contemporary black militancy configurations, which are shaped and expand in a translocal and diasporic arenas, while they project themselves as part of a nation, I delineate the black militancy cartographies in the three cities on the basis of their involvement in the public sphere. I examine: i) how the militancy networks are mobilized in the construction of their demands and, ii) their disputes for public policies in the fields of health and education, from gender and ethnic-racial perspectives. I also analyze the diversity of complex relations among social actors involved in the processes of translating local forms of resistance into problems, which will be brought to the public arena and will dispute for legitimization before agents and institutions that are capable of spreading them.
258

Hipersuperfícies em Rp+q+2 de curvatura escalar nula invariantes por O(p+1) x O(q+1). / O(p+1) x O(q+1) Invariant hypersurfaces with zero scalar curvature in Euclidean space Rp+q+2.

Melo, Rodrigo Fernandes de Moura 18 December 2009 (has links)
This dissertation has as base Jocelino Sato and Vicente de Souza Neto's paper called Complete and Stable O(p + 1) x O(q + 1)-Invariant Hypersurfaces with Zero Scalar Curvature in Euclidean Space Rp+q+2, published on the Annals of Global Analysis and Geometry - 29 in 2006. The main result of this dissertation is the Classi_cation Theorem, which states: The O(p+1) x O(q+1)-Invariant Hypersurfaces in Rp+q+2, p; q > 1, with zero scalar curvature belong to one of the following classes: (1) Cones with a singularity at the orign of Rp+q+2; (2) Hypersurfaces having one orbit of singularity and asymptoting both of the cones Cα and Cβ; (3) Regular hypersurfaces asymptoting the cone Cα; (4) Regular hypersurfaces asymptoting the cone Cβ; (5) Regular hypersurfaces asymptoting both of the cones Cα and Cβ. It was reached by the studies of the ordinary differential equation on R2, involving the coordenate curves that generate these hypersurfaces. Such differential equation, in its turn, is associated with a vector field X : R22 → R2 on the plan. The study of the orbits space in this field is essential; after all, because of it, it was possible to translate the X orbits' behavior into information concerning the profile curves and, finally, reach the theorem. / Fundação de Amparo a Pesquisa do Estado de Alagoas / Esta dissertação está baseada no artigo de Jocelino Sato e Vicente de Souza Neto intitulado Complete and Stable O(p+1) x O(q+1) - Invariant Hypersurfaces with Zero Scalar Curvature in Euclidean Space Rp+q+2, publicado na revista Annals of Global Analysis and Geometry, volume 29, em 2006. O principal resultado desta dissertação é o Teorema de Classicação, que afirma o seguinte: Uma hipersuperfície Mp+q+1 que é invariante pela açãoao do grupo O(p + 1) x O(q + 1), p; q > 1, com curvatura escalar identicamente nula deve pertencer a uma das seguintes classes: (1) Cones com uma singularidade na origem de Rp+q+2; (2) Hipersuperfícies possuindo uma órbita de singularidades e assintotando ambos os cones Cα e Cβ; (3) Hipersuperfícies regulares que assintotam o cone Cα; (4) Hipersuperfícies regulares que assintotam o cone Cβ; (5) Hipersuperfícies regulares que assintotam ambos os cones Cα e Cβ. A demonstração do teorema requer um estudo de uma equação diferencial ordinária envolvendo as coordenadas das curvas, no plano, que geram estas hipersuperfícies. Esta equação diferencial, por sua vez, está associada a um campo de vetores X : R2 → R2 no plano. O estudo do retrato de fase deste campo é fundamental. Através dele, foi possível traduzir o comportamento das trajetórias de X em informações com respeito às curvas geratrizes e desta maneira obter o teorema.
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"Que América Latina se sincere" : uma análise antropológica das políticas e poéticas do atavismo negro em face às ações afirmativas e às reparações no Cone Sul

Lopez, Laura Cecilia January 2009 (has links)
Esta tese se propõe a examinar os itinerários e as perspectivas das mobilizações políticas negras contemporâneas no Cone Sul, com ênfase nas redes de ativistas que atuam em Porto Alegre (Brasil), Montevidéu (Uruguai) e Buenos Aires (Argentina), frente aos atuais desafios da implementação de políticas públicas com enfoque étnico-racial. A partir do aporte da perspectiva antropológica que orienta uma aproximação da "experiência de perto" dos sujeitos, detenho-me no protagonismo de ativistas em face aos desdobramentos de políticas públicas e ações reparatórias. O trabalho se insere nas discussões sobre a questão multicultural e o multiculturalismo nas sociedades latino-americanas. Interrogo como sujeitos tidos e vistos como minoritários, que não foram contemplados no projeto de "igualdade" preconizado pelos ideais eurocêntricos de nação moderna instituído nos países da região, vêm a interferir na esfera pública, ao passo que evidenciam noções e projetos de nação em disputa. O trabalho busca compreender os movimentos afro-latino-americanos através das formas com que ocupam a esfera pública e manejam noções e projetos de sociedade multicultural. Analiso as conexões entre o "nacional" e o transnacional a partir das políticas raciais e das militâncias negras, bem como da experiência com identificações étnicas afro-diaspóricas. Parto das configurações locais das militâncias negras contemporâneas que se expandem e modelam numa arena trans-local e diaspórica e se projetam para o espaço da nação. Proponho-me delinear cartografias da militância negra nas três cidades contempladas nesta tese a partir de percorrer experiências múltiplas de engajamento na esfera pública. E por fim, examino: i) os modos como as redes de militância são mobilizadas na construção de demandas e ii) as disputas por políticas públicas em torno da saúde e da educação com perspectiva étnico-racial e de gênero, analisando as complexas e múltiplas relações entre atores sociais envolvidos no processo de tradução de resistências locais em problemas que irrompem as arenas públicas e disputam por sua legitimação perante agentes e instituições com condições para disseminálos. / This thesis aims at analyzing the itineraries and perspectives of the contemporary black movement political mobilization in the Southern Cone, focusing on the network of activists of Porto Alegre (Brazil), Montevideo (Uruguay) and Buenos Aires (Argentina), before the current challenges introduced by the implementation of ethnical-racial focused public policies. From an anthropological viewpoint that emphasizes a personal approach to the subjects' experiences, I concentrate on the activists' actions in the face of the consequences of public policies and reparatory actions. In the context of the debates on multicultural issues and multiculralisms in Latin-American societies, I will try to understand how those subjects that belong to the so-called minority groups, which, in turn, went unacknowledged by the European centered ideal of "equality" in the regional modern nation-states, impinge on the public sphere while they evidence notions and national projects that collide with each other. I, therefore, aim at understanding the political expression of African Latin- American movements through their uses of space in the public spheres and of dealing with the notions and projects of a multicultural society. I analyze the connections between the national and transnational from the viewpoint of racial policies, black militancies and the identification with the African diasporas. I begin by mapping contemporary black militancy configurations, which are shaped and expand in a translocal and diasporic arenas, while they project themselves as part of a nation, I delineate the black militancy cartographies in the three cities on the basis of their involvement in the public sphere. I examine: i) how the militancy networks are mobilized in the construction of their demands and, ii) their disputes for public policies in the fields of health and education, from gender and ethnic-racial perspectives. I also analyze the diversity of complex relations among social actors involved in the processes of translating local forms of resistance into problems, which will be brought to the public arena and will dispute for legitimization before agents and institutions that are capable of spreading them.
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[en] METROLOGICAL EVALUATION OF THE V-CONE TYPE METER PERFORMANCE FOR WET GAS FLOW RATE MEASUREMENT / [pt] AVALIAÇÃO METROLÓGICA DO DESEMPENHO DO MEDIDOR TIPO V-CONE PARA MEDIÇÃO DE VAZÃO DE GÁS ÚMIDO

THIAGO BARRA VIDAL DE OLIVEIRA 15 February 2018 (has links)
[pt] O objetivo deste trabalho é avaliar o desempenho metrológico e o potencial de aplicação do medidor tipo v-cone para medição de vazão de gás natural em condições de gás úmido. Observa-se que os medidores do tipo placa de orifício, geralmente utilizados na medição de vazão de gás no segmento de Exploração e Produção (E e P), podem não representar a tecnologia mais adequada. O medidor v-cone representa uma tecnologia relativamente recente, que vem demonstrando bom desempenho para a medição de vazão e vem ganhando aceitação de órgãos reguladores. O interesse e a motivação do pesquisador residem na busca de maior exatidão na medição de vazão em condições operacionais adversas (gás úmido não especificado), sem impacto significativo sobre o custo do sistema. O presente trabalho, por meio de uma pesquisa bibliográfica e documental, apresenta o estágio atual de desenvolvimento da tecnologia de medição por v-cone e detalha as características dos sistemas de medição de vazão de gás natural, além de abordar as normas e regulamentos relacionados ao tema em questão. A fase experimental busca avaliar o desempenho do medidor por meio de uma investigação empírica realizada em laboratório, simulando condições de gás úmido encontradas em campo. Essa análise envolve também a determinação de erros e incertezas de medição. A pesquisa realizada, em conjunto com a avaliação dos resultados dos testes e das correlações utilizadas, demonstra que o medidor v-cone apresenta boa confiabilidade na medição de vazão de gás natural em escoamento de gás úmido, podendo ser utilizado em aplicações encontradas no segmento de E e P. / [en] The aim of this study is to evaluate the metrological performance and potential of use of the v-cone type meter for measuring the natural gas flow rate under wet gas conditions. The orifice plate type meters, that are usually used to measure the gas flow rate in the Exploration and Production segment (E and P), may not represent the most appropriate technology. The v-cone meter represents a relatively recent technology, which has shown good performance for the flow rate measurement and is gaining acceptance from the regulators. The interest and motivation of the researcher are related to the quest for greater flow rate measurement accuracy in adverse operating conditions (unspecified wet gas), with no significant impact on the cost of the system. This work, through a literature and documentary search, presents the current stage of development of the v-cone flow rate measurement technology and details the characteristics of natural gas flow rate measurement systems, in addition to addressing the standards and regulations relating to the subject. The experimental phase aims to evaluate the meter performance through an empirical research conducted in laboratory, by simulating wet gas conditions found in the field. This analysis also involves the determination of measurement errors and uncertainties. The research and the evaluation of test results and correlations show that the v-cone meter has good reliability in natural gas flow rate measurement under wet gas conditions, allowing it to be used in applications found in E and P.

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