University, Diss., 2003--Freiburg (Breisgau).

Universiẗat, Diss., 2002--Osnabrück.

La radiogoniométrie consiste à mesurer l’angle d’incidence de signaux électromagnétiques. Elle a pour applications principales le contrôle du spectre et la guerre électronique. Dans le domaine des réseaux d’antennes pour la radiogoniométrie, de nouvelles problématiques sont apparues alors que les algorithmes de traitement d’antenne se perfectionnent. Ces dernières concernent la largeur de bande, la compacité et la diversité de polarisation. De précédents travaux ont initié la démarche de conception de telles antennes et réseaux pour la radiogoniométrie. L’objectif de ce travail de recherche a consiste en premier lieu a proposer une antenne de dimensions réduites opérant dans les bandes V/UHF et présentant une diversité de polarisation. Par la suite, il s’est agi de concevoir un réseau fonctionnel de radiogoniométrie intégrant l’antenne développe. Une antenne planaire de dimensions 150mm x 150mm (λ/4 x λ/4) a alors été conçue et réalisée entre 500 MHz et 3000 MHz. Sa mise en réseau permet des performances angulaires de l’ordre de 2° et moins sur la même bande pour des dimensions de 260mm (diamètre) x 150mm (hauteur) soit λ/2,3 x λ/4. Par la même occasion, un absorbant de faible épaisseur (25mm soit λ/24) a été développé et mesuré. Il permet une augmentation du rapport avant/arrière d’au moins 10dB de l’antenne développe sur sa bande de fonctionnement. / Radio direction finding (DF) allows for the measurement of the direction of arrival of incoming electromagnetic signals. Its main applications include spectrum monitoring and electronic warfare. DF antennas and arrays are subject to new problematics (bandwidth, compactness and polarization diversity) while DF algorithms have kept on improving. Previous works have initiated the design of such antennas and arrays. This work aims at designing an antenna with reduced dimensions for the VHF and UHF frequency bands and with a polarization diversity. This antenna shall then be integrated in a functional DF array. For this purpose, a planar antenna has been designed and measured in the 500-3000 MHz frequency band. Its final dimensions are 150mm x 150mm (λ/4 x λ/4). This antenna has then been integrated in the final DF array whose accuracy on the same frequency band is of the order of 2° for a final size of 260mm (diameter) x 150mm (height), that is λ/2,3 x λ/4. This study has also allowed for the design of a low-profile absorber (with a height of 25mm, that is λ/24 at its lowest frequency of operation). An increase of 10dB in the front to back ratio of the proposed antenna has been enabled by this absorber on its whole frequency band.

The influence of non-linearities on wave-induced motions and loads has been the focus of many investigations in the past few years and continues to be an important issue. A number of two- and three-dimensional methodologies have been developed, by and large, partly accounting for various non-linearities. Non-linear radiation, and to an extent diffraction, is the main problem and its solution via a three-dimensional method using Eulerian-Lagrangian schemes is likely to be complex and time consuming for practical applications. On the other hand two-dimensional methods, in spite of issues associated with accounting for forward speed, offer more possibilities of making practical advances in dealing with non-linearities. A two-dimensional hydroelasticity analysis for symmetric (i.e. vertical motions, distortions and loads) dynamic behaviour in waves, including the influence of nonlinearities, is presented in this thesis using two methods. In the first method the total response is decomposed into linear and non-linear parts. The linear part is evaluated using the conventional two-dimensional linear hydroelasticity analysis. The nonlinear hydrodynamic forces are due to changes in added mass and damping coefficients, as well as restoring and incident wave forces, all evaluated over the instantaneous wetted surface. Non-linear forces due to slamming (bottom impact and flare) and green water (treated in a quasi-static manner) are also added. One aim of the thesis is to investigate the influence/importance of each of the non-linear hydrodynamic forces. Furthermore, the effects of assumptions made when using these hydrodynamic forces, e.g. frequency dependence of added mass, neglecting the damping coefficients in some components and evaluation of derivatives, are investigated. The solution in the time domain is obtained using direct integration and convolution integration, the latter based on the impulse response functions of the hull in its mean wetted surface. In the second method the response, including nonlinearities, is obtained from the solution of one system of equations of motion, where the added mass and damping coefficients and the restoring, incident wave and diffraction forces are evaluated at the instantaneous draft. Non-linear forces due to slamming (bottom impact and flare) and green water (treated in a quasi-static manner) are also added. Both methods are applied to the S-175 containership, for which experimental measurements of motions and loads in large amplitude regular head waves are available. Comparisons made between predictions and measurements (heave and pitch motions, vertical acceleration and vertical bending moment) indicate good overall agreement. The comparisons also show that the influence of flare slamming is important for the range of speeds and wave amplitudes investigated.

Kite propulsion has emerged as an attractive means to harness wind power in a way that yields environmental and financial benefits. An understanding of the dynamics that affect kite motion and the resulting forces is required to facilitate the design and optimization of kite propulsion systems. In this thesis results from two line tension models are compared with experimentally recorded time histories for dynamic kite flight. New methodologies for investigating kite performance are established. The first zero mass model assumes that the kite and lines are weightless. The second, lumped mass model, considers the kites mass and thus makes use of the equations of motion. It is found that the two different models converge to the same result in the limit where the kite mass tends to zero. The zero mass model has been shown to compare favourably with experimental results. A method for parameterising figure of eight shape kite trajectories and for predicting kite velocity is presented. Results are shown for a variety of manoeuvre shapes, assuming realistic performance characteristics from an experimental test kite. Using a 320m2 kite, with 300m long flying lines in 6.18ms.

CARVALHO,Eunice Bobô. Detecção do fator V Leiden em pacientes trombofílicos no Estado do Ceará. 2004. 78 f. Dissertação (Mestrado em Patologia) - Universidade Federal do Ceará. Faculdade de Medicina, Fortaleza, 2004. / Submitted by denise santos (denise.santos@ufc.br) on 2011-12-21T11:29:49Z No. of bitstreams: 1 2004_dis_ebcarvalho.pdf: 998962 bytes, checksum: c560c5936245ac6fd18968caebc03259 (MD5) / Approved for entry into archive by Eliene Nascimento(elienegvn@hotmail.com) on 2012-02-01T16:11:33Z (GMT) No. of bitstreams: 1 2004_dis_ebcarvalho.pdf: 998962 bytes, checksum: c560c5936245ac6fd18968caebc03259 (MD5) / Made available in DSpace on 2012-02-01T16:11:33Z (GMT). No. of bitstreams: 1 2004_dis_ebcarvalho.pdf: 998962 bytes, checksum: c560c5936245ac6fd18968caebc03259 (MD5) Previous issue date: 2004 / As doenças trombóticas constituem um sério problema na saúde mundial. Diversas desordens hereditárias, que afetam o sistema fisiológico anticoagulante, estão atualmente estabelecidas como fatores de risco para a ocorrência do evento trombótico. Dentre estes o fator V Leiden é o mais freqüente. A associação entre alterações no gene do fator V e a ocorrência de eventos trombóticos desencadeou o desenvolvimento de diversas pesquisas. Neste estudo, 100 pacientes portadores de eventos trombóticos, atendidos no ambulatório de Hematologia do Centro de Hematologia e Hemoterapia do Ceará - HEMOCE/SESA/UFC, foram analisados para a detecção da presença do fator V Leiden. O grupo controle consistiu de 110 voluntários sadios. A freqüência encontrada na população controle foi de 2,7% (03/110), enquanto que nos pacientes trombofílicos foi de 9% (09/100). Destes, 77,8% (07/09) eram do sexo feminino e 22,2% (02/09) do sexo masculino e a cor predominante foi a parda [66,7% (06/09)]. A faixa etária mais freqüente foi entre 26 e 33 anos [33,4% (03/09)]. Do total dos pacientes portadores do fator V Leiden, 88,9% (08/09) apresentaram trombose venosa profunda e 11,1% (01/09) trombose arterial com recorrência do evento trombótico de 22,2% (02/09). A correlação entre a presença do evento trombótico/presença do fator V Leiden e o uso de contraceptivo oral foi de 71,4% (05/07). Das pacientes portadoras e que usaram contraceptivo oral não ocorreu o aborto. A localização do primeiro evento trombótico, nos portadores, foi predominantemente nos membros inferiores [88,9% (08/09)] e 11,1% (01/09), nas artérias coronárias. Em 44,4% (04/09) havia um ou mais fatores de risco/morbidade associado. A freqüência da mutação encontrada no estado do Ceará mostrou-se inferior aos dados obtidos na região de Botucatu (SP) - 12% e ao estudo de Benson, em Atlanta (EUA)- 12,4 e ainda menor que os encontrados na região de Campinas (SP)- 20% e à população com ancestral europeu-18%. A diferença entre pacientes trombofílicos e população controle não foi estatisticamente significante (p=0,19), mas o risco estimado para o evento trombótico foi de 2,46.

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