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Structural Characterization, Optimization, and Failure Analysis of a Human-powered OrnithopterRobertson, Cameron David 15 February 2010 (has links)
The objective of this work was to develop an analysis framework for the structural design
of the Human-Powered Ornithopter (HPO). This framework was used in a kinematicaerostructural
optimizer for
apping-wing
ight (Ornithia), as well as analytically to design
the HPO, and focused on three goals. First was the development of an accurate and computationally
inexpensive nite-element method, to be integrated with Ornithia, which would
capture the geometric nonlinearity of the aerostructural interaction of the wing when subjected
the large deformations in
ight. Second was the assembly of a model by which the
aircraft primary structure, the wing main spar especially, could be exactly characterized and
designed. Third was the establishment of a process and toolbox for failure analysis which
could be applied universally in the design of the HPO. The validation and tuning of these
models involved extensive testing on prototype carbon ber composite components.
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Etude des comètes en interférométrie mililmétriqueBoissier, Jeremie 23 November 2007 (has links) (PDF)
Les comètes nous renseignent sur les conditions physico-chimiques du Système Solaire en formation. Leur observation en interférométrie millimétrique permet de cartographier l'émission des molécules dans la coma interne et d'étudier la morphologie du dégazage depuis le noyau. Des données de qualité unique ont été obtenues sur la comète C/1995 O1 (Hale-Bopp) avec l'interféromètre du Plateau de Bure de l'IRAM. Au cours de ma thèse j'ai analysé les données concernant H2S, SO, CS et CO. Mes travaux montrent que les molécules H2S et CO proviennent du noyau. La distribution radiale de l'emission de CS est compatible avec une source légèrement étendue, en accord avec sa production par la photolyse de CS2. Le taux de photodissociation de CS est mesuré. La distribution radiale de SO est plus étendue que si ce radical était créé uniquement par la photodissociation de SO2. Cela suggère la présence dans la coma d'une autre source de SO ou d'une source étendue de SO2. Les observations indiquent que H2S est libéré de manière quasi isotrope à la surface du noyau. CS et SO sont présents dans un jet à haute latitude sur le noyau. Le jet de CO proche de l'équateur résulte d'une inhomogénéité de production à la surface et non d'une structure de choc liée à la forme et à la topographie du noyau, comme le montrent les simulations réalisées à partir des résultats d'un modèle hydrodynamique de coma. Nous interprétons les différences entre les profils de dégazage des différentes espèces comme une conséquence de l'inhomogénéité de composition du noyau. Les outils et les méthodes développés seront utiles pour préparer et analyser les futures observations de comètes en interférométrie millimétrique.
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Design strategies for rotorcraft blades and HALE aircraft wings applied to damage tolerant wind turbine blade designRichards, Phillip W. 08 June 2015 (has links)
Offshore wind power production is an attractive clean energy option, but the difficulty of access can lead to expensive and rare opportunities for maintenance. Smart loads management (controls) are investigated for their potential to increase the fatigue life of damaged offshore wind turbine rotor blades. This study will consider two commonly encountered damage types for wind turbine blades, the trailing edge disbond (bond line failure) and shear web disbond, and show how 3D finite element modeling can be used to quantify the effect of operations and control strategies designed to extend the fatigue life of damaged blades.
Modern wind turbine blades are advanced composite structures, and blade optimization problems can be complex with many structural design variables and a wide variety of aeroelastic design requirements. The multi-level design method is an aeroelastic structural design technique for beam-like structures in which the general design problem is divided into a 1D beam optimization and a 2D section optimization. As a demonstration of aeroelastic design, the multi-level design method is demonstrated for the internal structural design of a modern composite rotor blade. Aeroelastic design involves optimization of system geometry features as well as internal features, and this is demonstrated in the design of a flying wing aircraft. Control methods such as feedback control also have the capability alleviate aeroelastic design requirements and this is also demonstrated in the flying wing aircraft example.
In the case of damaged wind turbine blades, load mitigation control strategies have the potential to mitigate the effects of damage, and allow partial operation to avoid shutdown. The load mitigation strategies will be demonstrated for a representative state-of-the-art wind turbine (126m rotor diameter). An economic incentive will be provided for the proposed operations strategies, in terms of weighing the cost and risk of implementation against the benefits of increased revenue due to operation of damaged turbines. The industry trend in wind turbine design is moving towards very large blades, causing the basic design criterion to change as aeroelastic effects become more important. An ongoing 100 m blade (205 m rotor diameter) design effort intends to investigate these design challenges. As a part of that effort, this thesis will investigate damage tolerant design strategies to ensure next-generation blades are more reliable.
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Standing in the Center of the World: The Ethical Intentionality of AutoethnographyWilkes, Nicole 13 July 2009 (has links) (PDF)
Emmanuel Levinas's philosophy of ipseity and alterity has permeated Western thought for more than forty years. In the social sciences and the humanities, the recognition of the Other and focus on difference, alterity, has influenced the way we ethically approach peoples and arts from different cultures. Because focus on the ego, ipseity, limits our ethical obligations, focusing on the Other does, according to Levinas, bring us closer to an ethical life. Furthermore, the self maintains responsibility for the Other and must work within Levinas's ethical system to become truly responsible. Therefore, the interaction between self and Other is Levinas's principal concern as we move toward the New Humanism. The traditional Western autobiography has been centered in the self, the ego, which may prevent the ethical interaction on the part of the writer because the writer often portrays himself or herself as exemplary or unique rather than as an individual within a culture who is responsible for others. Nevertheless, life writing has expanded as writers strive to represent themselves and their cultures responsibly. One form that has emerged is the literary autoethnography, a memoir that considers ancestry, culture, history, and spiritual inheritance amidst personal reflection. In particular, Native American conceptions of the self within story have inspired conventions of literary autoethnography. This project explores the way Native American worldviews have influenced the autoethnography by looking at four Native American authors: Janet Campbell Hale, N. Scott Momaday, Leslie Marmon Silko, and Carter Revard. Through research, family stories, interviews, and returns to ancestral spaces, autoethnographers can bring themselves and their readers closer to cultural consciousness. By investigating standards in autoethnographic works, this project will illustrate the ethical intentionality of autoethnography.
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Diffusion de la lumière par des agrégats irréguliers: simulations numériques et expérimentales, applications aux petits corps dans le système solaireLasue, Jérémie A.F. 29 September 2006 (has links)
Les particules cométaires sont des témoins de l’évolution du système solaire, dont les caractéristiques peuvent être estimées à partir de la lumière qu’elles diffusent et émettent.<p>Je montre qu’un modèle de diffusion lumineuse par un nuage d’agrégats fractals et de sphéroïdes permet d’interpréter, en fonction de la distribution en taille et des matériaux constitutifs, des observations polarimétriques en angle de phase et longueur d'onde. Le modèle est en particulier appliqué à la comète Hale-Bopp, et au milieu interplanétaire en modélisant aussi les observations thermiques.<p>Je développe des outils de diffusion lumineuse (numériques et expérimentaux) pour analyser des agrégats analogues aux particules protoplanétaires qui seront formés avec ICAPS à bord de l’ISS. De façon complémentaire, une simulation expérimentale en vol parabolique avec PROGRA2 me permet de déterminer les propriétés physiques de microparticules d’intérêt astrophysique par des mesures polarimétriques.<p> / Doctorat en sciences appliquées / info:eu-repo/semantics/nonPublished
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La comète Hale-Bopp à l'interféromètre du Plateau de Bure : étude de la distribution du monoxyde de carboneHenry, Florence 23 June 2003 (has links) (PDF)
La comète C/1995 O1 (Hale-Bopp) a sans doute été l'une des comètes les plus brillantes jamais observées jusqu'à présent. Son extraordinaire activité a permis pour la première fois d'entreprendre des observations en interférométrie millimétrique avec une grande sensibilité. Lors de son passage au périhélie, les transitions J(2-1) et J(1-0) du monoxyde de carbone, ont été observées avec l'interféromètre du Plateau de Bure de l'Institut de Radio Astronomie Millimétrique (IRAM), à 230 GHz et 115 GHz respectivement. L'analyse temporelle des observations faites en parallèle en mode antenne unique a d'abord permis de mettre en évidence la présence d'un jet de CO en rotation dans l'atmosphère de la comète. L'étude des cartes interférométriques a ensuite montré que la coma était spatialement et spectralement anisotrope. Afin d'analyser au mieux ces données, nous avons développé un modèle d'atmosphère cométaire en 3 dimensions, et simulé les observations. Le modèle consiste en une coma isotrope à laquelle on ajoute un jet de forme conique qui spirale dans la coma à cause de la rotation du noyau. La comparaison des simulations aux observations s'est faite sur l'évolution temporelle des décalages spectraux, et sur celle des visibilités, qui sont les quantités physiques qu'un interféromètre mesure et qui représentent la Transformée de Fourier de la distribution de brillance du gaz sur le plan du ciel. Cette étude a confirmé la présence d'un jet spiralant dans la coma. De plus, nous avons pu déterminer les paramètres du jet tels que la position, l'ouverture et l'intensité, qui interprètent au mieux les observations. La question de l'origine de CO dans la coma est également abordée en dernière partie. Nos observations suggèrent que cette molécule proviendrait pour moitié du noyau, et pour moitié d'une source étendue.
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Foundations of Deduction's Pedigree: A Non-Inferential AccountSeitz, Jeremy January 2009 (has links)
In this thesis I discuss the problems associated with the epistemological task of arriving at basic logical knowledge. This is knowledge that the primitive rules of inference we use in deductive reasoning are correct. Knowledge of correctness, like all knowledge, is available to us either as the product of inference, or it is available non-inferentially. Success in the campaign to justify the correctness of these rules is mired by opposing views on how to do this properly. Inferential justifications of rules of inference, which are based on reasons, lead to regressive or circular results. Non-inferential justifications, based on something other than reasons, at first do not seem to fare any better: without a basis for these justifications, they appear arbitrary and unfounded.
The works of Boghossian and Dummett who argue for an inferentialist approach, and Hale who supports non-inferentialism are carefully examined in this thesis. I conclude by finding superiority in Hale's suggestion that a particular set of basic logical constants are indispensable to deductive reasoning. I suggest that we endorse a principle which states that rules are not premises, and are therefore to be excluded from expression as statements in a deductive argument. I argue that the quality of being indispensable is sufficient for a basic rule of deduction to be countenanced as default-justified, and therefore need not be expressed in argument. By a rule's evading expression in argument, it avoids circular reasoning in deductive arguments about its own correctness.
Another important outcome that emerges from my research is the finding that non-inferential knowledge is ontologically prior to the inferential sort. This is because plausible inferential knowledge of basic logical constants shall always be justified by circular reasoning that already assumes the correctness of the rule to be vindicated. This initial assumption is tantamount to non-inferential knowledge, and therefore this latter is more primitive-in fact the only primitive-species of basic logical knowledge.
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Foundations of Deduction's Pedigree: A Non-Inferential AccountSeitz, Jeremy January 2009 (has links)
In this thesis I discuss the problems associated with the epistemological task of arriving at basic logical knowledge. This is knowledge that the primitive rules of inference we use in deductive reasoning are correct. Knowledge of correctness, like all knowledge, is available to us either as the product of inference, or it is available non-inferentially. Success in the campaign to justify the correctness of these rules is mired by opposing views on how to do this properly. Inferential justifications of rules of inference, which are based on reasons, lead to regressive or circular results. Non-inferential justifications, based on something other than reasons, at first do not seem to fare any better: without a basis for these justifications, they appear arbitrary and unfounded.
The works of Boghossian and Dummett who argue for an inferentialist approach, and Hale who supports non-inferentialism are carefully examined in this thesis. I conclude by finding superiority in Hale's suggestion that a particular set of basic logical constants are indispensable to deductive reasoning. I suggest that we endorse a principle which states that rules are not premises, and are therefore to be excluded from expression as statements in a deductive argument. I argue that the quality of being indispensable is sufficient for a basic rule of deduction to be countenanced as default-justified, and therefore need not be expressed in argument. By a rule's evading expression in argument, it avoids circular reasoning in deductive arguments about its own correctness.
Another important outcome that emerges from my research is the finding that non-inferential knowledge is ontologically prior to the inferential sort. This is because plausible inferential knowledge of basic logical constants shall always be justified by circular reasoning that already assumes the correctness of the rule to be vindicated. This initial assumption is tantamount to non-inferential knowledge, and therefore this latter is more primitive-in fact the only primitive-species of basic logical knowledge.
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A behavioral analysis of two spaces in Kansas State University's Hale Library based on psychologist Roger Barker's behavior setting theoryManandhar, Sachit January 1900 (has links)
Master of Science / Department of Architecture / David Seamon / This thesis uses behavioral mapping to analyze two contrasting spaces in Kansas State University’s Hale Library. One of the spaces is meant for computer use; and the other for general library use, including study-group work. The conceptual approach chosen to describe and analyze these two library spaces is the behavior-setting theory developed by psychologist Roger Barker, who defines behavior settings as independent units of space, with temporal and spatial boundaries, that have “great coercive power over the behaviors that occur within them” (Barker, 1968, p. 17). The behavioral observations for the two Hale Library spaces were analyzed and compared with findings from other studies of library usage and behaviors.
In the first chapter of the thesis, I introduce my study topic and discuss recent developments in libraries. In the second chapter, I provide a broad overview of library history and library use. I also overview behavior-setting theory and present examples of research on behavior settings and libraries. In the third chapter, I discuss research methods for this thesis, starting with how library spaces can be described as behavior settings. I then discuss specific methodological procedures involved in the behavioral study of activities in the two library spaces. In the fourth chapter, I discuss the two spaces studied in Hale Library, first, describing their physical features and then discussing their behavior-setting attributes. In the fifth chapter, I present my behavioral observations and compare and contrast the two Hale Library spaces in terms of user behaviors and as behavior settings. In the sixth and final chapter of this thesis, I compare my research results with other library research and offer my speculative ideas on the future of the academic library.
The overarching theme of this thesis is evaluating how recent digital technologies have affected libraries, and how traditional library spaces and spaces designated for digital technology can be integrated in future libraries.
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Nonlinear Aeroelastic Analysis of Flexible High Aspect Ratio Wings Including Correlation with ExperimentJaworski, Justin January 2009 (has links)
<p>A series of aeroelastic analyses is performed for a flexible high-aspect-ratio wing representative of a high altitude long endurance (HALE) aircraft. Such aircraft are susceptible to dynamic instabilities such as flutter, which can lead to large amplitude limit cycle oscillations. These structural motions are modeled by a representative linear typical section model and by Hodges-Dowell beam theory, which includes leading-order nonlinear elastic coupling. Aerodynamic forces are represented by the ONERA dynamic stall model with its coefficients calibrated to CFD data versus wind tunnel test data. Time marching computations of the coupled nonlinear beam and ONERA system highlight a number of features relevant to the aeroelastic response of HALE aircraft, including the influence of a tip store, the sensitivity of the flutter boundary and limit cycle oscillations to aerodynamic CFD or test data, and the roles of structural nonlinearity and nonlinear aerodynamic stall in the dynamic stability of high-aspect-ratio wings.</p> / Dissertation
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