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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.
1

Simulation of Squat Exercise Effectiveness Utilizing a Passive Resistive Exoskeleton in Zero Gravity

Stetz, Eric J. 28 June 2016 (has links)
No description available.
2

Vliv specifického pohybového programu na kvalitu skeletu u pacientek s osteoporózou hodnocený kostní DXA denzitometrií / The influence of a specific movement therapy for bone density in female patients evaluated by bone DXA densitomentry

Kuba, Kryštof January 2012 (has links)
Title: The influence of a specific movement therapy for bone density in female patients evaluated by bone DXA densitometry Objectives: The aim was to demonstrate the positive impact of movement on bone mineral density in patients suffering from postmenopausal osteoporosis. Summary: The main topic of this thesis is to evaluate potential benefits of an intensive program to the treatment of patients suffering from postmenopausal osteoporosis treated with the standard pharmacological therapy. The marker determined to evaluate the effect of change in bone density was DXA bone densitometry in the standard locations (lumbar spine, proximal femur). The evaluation of measurement results was performed after six-month program. Methods: The experiment, which was the substantial part of this thesis, was based on the method of comparison of input and output values in experimental and control groups. Each group consisted of 15 patients. Measured parameters of bone density were deliberately affected by means of physical interventions in the experimental group of patients. The results were processed and evaluated by Microsoft Excel and SAS 9. 2 programs. Results: Physical intervention is an essential part of therapy in patients suffering from postmenopausal osteoporosis. The experiment proved that a six-month...
3

Topology optimization of acoustic metamaterials / 音響メタマテリアルのトポロジー最適化

Lu, Li Rong 23 May 2014 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18469号 / 工博第3905号 / 新制||工||1599(附属図書館) / 31347 / 京都大学大学院工学研究科機械理工学専攻 / (主査)教授 西脇 眞二, 教授 椹木 哲夫, 教授 松原 厚 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
4

Significance of the Alfvén waves in the thermospheric dynamics in the cusp region / カスプ域の熱圏ダイナミクスにおけるアルフベン波の重要性

Oigawa, Tomokazu 23 March 2022 (has links)
京都大学 / 新制・課程博士 / 博士(理学) / 甲第23709号 / 理博第4799号 / 新制||理||1687(附属図書館) / 京都大学大学院理学研究科地球惑星科学専攻 / (主査)教授 田口 聡, 教授 松岡 彩子, 教授 榎本 剛 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM
5

Bayesian Hierarchical Latent Model for Gene Set Analysis

Chao, Yi 13 May 2009 (has links)
Pathway is a set of genes which are predefined and serve a particular celluar or physiological function. Ranking pathways relevant to a particular phenotype can help researchers focus on a few sets of genes in pathways. In this thesis, a Bayesian hierarchical latent model was proposed using generalized linear random effects model. The advantage of the approach was that it can easily incorporate prior knowledges when the sample size was small and the number of genes was large. For the covariance matrix of a set of random variables, two Gaussian random processes were considered to construct the dependencies among genes in a pathway. One was based on the polynomial kernel and the other was based on the Gaussian kernel. Then these two kernels were compared with constant covariance matrix of the random effect by using the ratio, which was based on the joint posterior distribution with respect to each model. For mixture models, log-likelihood values were computed at different values of the mixture proportion, compared among mixtures of selected kernels and point-mass density (or constant covariance matrix). The approach was applied to a data set (Mootha et al., 2003) containing the expression profiles of type II diabetes where the motivation was to identify pathways that can discriminate between normal patients and patients with type II diabetes. / Master of Science
6

Résonateurs mécaniques pour la mesure de la masse volumique et de la viscosité de liquide / Mechanical resonators for liquid viscosity and mass density sensing

Heinisch, Martin 25 September 2015 (has links)
Cette thèse synthétise les travaux récents de l’auteur sur l’utilisation de résonateurs mécaniques pour la détermination simultanée de la viscosité et de la masse volumique de liquides. Ces travaux ont été réalisés entre 2010 et 2015 dans le cadre d’une thèse en cotutelle entre l’Institut de Microélectronique et des Microcapteurs de l’Université Johannes Kepler à Linz en Autriche et le Laboratoire de l’Intégration du Matériau au Système de l’Université de Bordeaux en France. Dans des études précédentes effectuées sur ce sujet par les groupes des deux laboratoires, le concept de l’utilisation de résonateurs mécaniques actionnés et mesurés électriquement pour la détermination de la viscosité et de la masse volumique deliquide avait été établi et validé. Ces travaux antérieurs ont montré que la fréquence de résonance et le facteur de qualité de résonateurs immergés dépendent à la fois de la viscosité et de la masse volumique du fluide environnant.L’intérêt d’utiliser de tels microcapteurs résonants vient du fait qu’il est possible de les utiliser in-situ,notamment pour des applications industrielles. Pour ce type d’applications, il est important que les capteurs aient entre autre une bonne résistance physique, une bonne stabilité à long terme, une bonne fiabilité, ainsi qu’une bonne précision de mesure. Pour satisfaire ces exigences et compte tenu des résultats des travaux antérieurs, les objectifs principaux de cette thèse étaient (1) la mise en oeuvre de configurations de mesure robustes offrant une bonne stabilité à long terme et une bonne précision de mesure, ce qui nécessite une faible sensibilité à la température, (2) la mesure simultanée de la viscosité et de la masse volumique avec un seul capteur et (3) la modélisation et la comparaison des performances des différents dispositifs mis au point et testés. Ces trois objectifs ont été atteints en combinant des approches expérimentales et théoriques (hydrodynamique, mécanique du solide et électrodynamique). [...] / This thesis summarizes the author’s recent work on the topic of mechanical resonators for liquidviscosity and mass density sensing, which were achieved between 2010 and 2015 in the course of aninternational joint doctorate program performed at the Institute for Microelectronics and Microsensorsat the Johannes Kepler University Linz, Austria and the Laboratoire de l’Intégration du Matériau auSystème in Bordeaux, France. In previous studies performed by work groups of both laboratories,the concept of using electrically actuated and read-out mechanical resonators for the determination ofliquids’ viscosities and mass densities has been established and elaborated. These works showed that theresonance frequencies and quality factors of immersed resonators are affected by the liquids’ viscositiesand mass densities, respectively. The investigated concepts included devices using structured polymeror wet-etched new silver sheets as well as micro-machined silicon and screen-printed PZT resonators.The motivation for investigating and developing such miniaturized resonators was formed, amongstothers, by their capability for in-line, in-situ and handheld-devices for laboratory as well as for industrialapplications. Especially for the latter, physical robustness, long-term stability and reliability,as well as accurate measurement results are basic requirements. To satisfy these requirements andconsidering the results and insights of earlier works, the objectives of this thesis were first, implementingrobust measuring setups featuring long-term stability and high measurement accuracy, where thelatter furthermore requires low cross-sensitivity to temperature. Second, investigating the capabilityof measuring both, a liquid’s mass density and viscosity with a single device as well as providing anestimate of achievable measurement accuracies for both quantities. And third, enabling the modelingof the performance of different viscosity and mass density sensors on the one side and their comparisonon the other side. These three specifications were accomplished by following mainly experimental approachesand investigations but also by elaborating the underlying theory of hydrodynamics, structuralmechanics, and electrodynamics. [...] / Die vorliegende Dissertation fasst die rezenten Forschungsergebnisse des Verfassers im Bereich mechanischerResonatoren für Viskositäts- und Dichtesensorik zusammen, welche zwischen 2010 und 2015 imRahmen eines international joint doctorate programs am Institut für Mikroelektronik und Mikrosensorikder Johannes Kepler Universität Linz, sowie am Laboratoire de l’Intégration du Matériau auSystème der Université de Bordeaux erreicht wurden. In den Vorarbeiten von Arbeitsgruppen beiderInstitute wurden bereits Konzepte für elektrisch angeregte und ausgelesene mechanische Resonatorenzur Bestimmung von Viskosität und Dichte von Flüssigkeiten erarbeitet und umgesetzt. Hierbei konntegezeigt werden, dass die Resonanzfrequenz und Güte eingetauchter Resonatoren abhängig sindvon Viskosität und Dichte der jeweiligen Flüssigkeiten. Die dabei untersuchten Konzepte beinhaltetenstrukturierte Polymerfolien, nass-chemisch geätzte Neusilberbleche, mikromechanisch hergestellte Siliziumstrukturen,sowie siebgedruckte PZT Resonatoren.Die Motivation zur Untersuchung und Entwicklung solcher miniaturisierter Resonatoren resultiert unteranderem aus deren Anwendbarkeit für Inline-, Insitu- und Handgeräte für Labor- bzw. industrielle Anwendungen.Besonders für Letztere sind Robustheit, Langzeitstabilität und Zuverlässigkeit, aber auchpräzise Messergebnisse Grundvoraussetzung. Um den Anforderungen der Ergebnisse und Erkenntnisseder zuvor genannten Arbeiten gerecht zu werden, wurden folgende Ziele für diese Dissertationdefiniert. Erstens, die Entwicklung robuster, langzeitstabiler Messaufbauten zur Erreichung präziserMessergebnisse, wodurch eine geringe Temperaturquerempfindichkeit als weitere Bedingung aufgestelltwurde. Zweitens sollte untersucht werden ob und mit welcher Genauigkeit sowohl Viskosität als auchDichte mit einem einzigen Instrument gemessen werden können. Drittens, sollte einerseits das Verhaltenverschiedener Viskositäts- und Dichtesensoren modelliert bzw. deren Vergleich ermöglicht werden.Basierend auf einer vorwiegend experimentellen Herangehensweise und unter Miteinbeziehung der zugrundeliegendenTheorien von Strömungs- und Strukturmechanik sowie der Elektrodynamik, konntendie o.g. Anforderungen erfüllt werden. [...]
7

Konstrukční vlastnosti ultralehkých betonů a jeho optimální využití v konstrukcích / Structural Properties of Ultralight Concrete and its Optimal Application in Structures

Kadlec, Jaroslav January 2017 (has links)
This doctoral thesis deals with design of three variants of ultra lightweight concrete (ULC) and their mechanical properties. The ULC usually has the dry density of 900-1200 kg/m3 and it is possible to use it for load bearing structures. Low density of ULC is achieved by replacing heavy aggregate for lightweight aggregate. The lightweight aggregate is known under the trade name Liapor in the Czech Republic. To achieve density below 1000 kg/m3, an aeration of the paste has to be done. An exchange of heavy aggregate for lightweight aggregate results in a very fragile behavior of ULC. A great attention is paid to bond strength between concrete and reinforcing steel in the thesis. In addition to the standard test of bond strength testing by pull-out, a modified pull-out test is designed, which includes the effect of minimum reinforcement cover. The mentioned test more precisely simulates a real behaviour of the structure exposed to bending moment. The doctoral thesis tries to point out on different parameters between measured data and the applicable standard for the design of load-bearing structures.
8

Enhanced 3-Dimensional Carbon Nanotube Based Anodes for Li-ion Battery Applications

Kang, Chi Won 28 June 2013 (has links)
A prototype 3-dimensional (3D) anode, based on multiwall carbon nanotubes (MWCNTs), for Li-ion batteries (LIBs), with potential use in Electric Vehicles (EVs) was investigated. The unique 3D design of the anode allowed much higher areal mass density of MWCNTs as active materials, resulting in more amount of Li+ ion intake, compared to that of a conventional 2D counterpart. Furthermore, 3D amorphous Si/MWCNTs hybrid structure offered enhancement in electrochemical response (specific capacity 549 mAhg-1). Also, an anode stack was fabricated to further increase the areal or volumetric mass density of MWCNTs. An areal mass density of the anode stack 34.9 mg/cm2 was attained, which is 1,342% higher than the value for a single layer 2.6 mg/cm2. Furthermore, the binder-assisted and hot-pressed anode stack yielded the average reversible, stable gravimetric and volumetric specific capacities of 213 mAhg-1 and 265 mAh/cm3, respectively (at 0.5C). Moreover, a large-scale patterned novel flexible 3D MWCNTs-graphene-polyethylene terephthalate (PET) anode structure was prepared. It generated a reversible specific capacity of 153 mAhg-1 at 0.17C and cycling stability of 130 mAhg-1 up to 50 cycles at 1.7C.
9

Detecção da transformação da austenita retida por deformação plástica em aços para gasodutos classe API 5L X80 através de medidas magnéticas. / Detecting austenite transformation by plastic deformation in grade API 5L X80 pipeline steel by magnetic properties.

Almeida, Alan Barros de 06 December 2013 (has links)
O presente trabalho avaliou o efeito de tratamentos térmicos ou diferentes graus de deformação plástica na transformação da austenita do microconstituinte AM de uma chapa de aço alta resistência baixa liga (ARBL) classe API 5L X80 usada para gasodutos. A chapa tem espessura de 19 mm e passaria pelo processo de conformação UOE, mas a deformação foi realizada por laminação a frio, a temperatura ambiente, com reduções de 5 a 20%. O propósito foi compreender melhor o microconstituinte AM, explorar a transformação martensítica induzida por deformação (SIMT) e a decomposição austenítica por tratamento térmico, com ênfase em seu comportamento magnético. A transformação da austenita foi acompanhada através de medidas de polarização magnética, comparada com a densidade de massa e difração de raios X. A deformação plástica e os tratamentos térmicos alteraram a polarização magnética de saturação e a densidade de massa da amostra de aço de forma compatível com a eliminação da austenita retida metaestável. O método de densidade hidrostática foi considerado sensível para mensurar transformações de fase. Os dados obtidos revelam expansão volumétrica de aproximadamente 0,13%, correspondendo a 3,2% a quantidade de austenita retida original do material, enquanto os valores obtidos por polarização magnética de saturação são 2,8% pelo histeresígrafo e 2,1% por MAV. A difração de raios X nas amostras sob deformação ou tratamentos térmicos resultaram em queda nos primeiros picos da austenita quando comparadas com a amostra como recebida. / This study evaluated the effect of different degrees of plastic deformation or heat treatment on the transformation of austenite into martensite of an HSLA steel plate API 5L X80 for pipelines. A 19 mm thickness plate would be submitted to UOE forming process, but the cold work instead occurred by cold rolling at room temperature, with reductions of 5 up to 20%. The purpose was to better understand the MA constituent, explore the strain-induced martensitic transformation (SIMT) and austenitic decomposition by heat treatment with emphasis on its magnetic behavior. The transformation was accompanied by saturation magnetization measurements, compared with the mass density and X-ray diffraction. The plastic deformation or the heat treatment altered the saturation magnetization and the mass density in a manner consistent with the elimination of metastable retained austenite. The density method is sensible to measure phase transformations induced by strain. The data obtained shows a volumetric expansion of about 0.13%, corresponding to an amount of retained austenite of the original material of 3.2%, while the values obtained by magnetization saturation are 2.8% by hysteresigraph and 2.1% by VSM. By X-ray diffraction there is a clear drop in first peaks of austenite of the samples under deformation or heat treatment compared with the sample as-received.
10

Detecção da transformação da austenita retida por deformação plástica em aços para gasodutos classe API 5L X80 através de medidas magnéticas. / Detecting austenite transformation by plastic deformation in grade API 5L X80 pipeline steel by magnetic properties.

Alan Barros de Almeida 06 December 2013 (has links)
O presente trabalho avaliou o efeito de tratamentos térmicos ou diferentes graus de deformação plástica na transformação da austenita do microconstituinte AM de uma chapa de aço alta resistência baixa liga (ARBL) classe API 5L X80 usada para gasodutos. A chapa tem espessura de 19 mm e passaria pelo processo de conformação UOE, mas a deformação foi realizada por laminação a frio, a temperatura ambiente, com reduções de 5 a 20%. O propósito foi compreender melhor o microconstituinte AM, explorar a transformação martensítica induzida por deformação (SIMT) e a decomposição austenítica por tratamento térmico, com ênfase em seu comportamento magnético. A transformação da austenita foi acompanhada através de medidas de polarização magnética, comparada com a densidade de massa e difração de raios X. A deformação plástica e os tratamentos térmicos alteraram a polarização magnética de saturação e a densidade de massa da amostra de aço de forma compatível com a eliminação da austenita retida metaestável. O método de densidade hidrostática foi considerado sensível para mensurar transformações de fase. Os dados obtidos revelam expansão volumétrica de aproximadamente 0,13%, correspondendo a 3,2% a quantidade de austenita retida original do material, enquanto os valores obtidos por polarização magnética de saturação são 2,8% pelo histeresígrafo e 2,1% por MAV. A difração de raios X nas amostras sob deformação ou tratamentos térmicos resultaram em queda nos primeiros picos da austenita quando comparadas com a amostra como recebida. / This study evaluated the effect of different degrees of plastic deformation or heat treatment on the transformation of austenite into martensite of an HSLA steel plate API 5L X80 for pipelines. A 19 mm thickness plate would be submitted to UOE forming process, but the cold work instead occurred by cold rolling at room temperature, with reductions of 5 up to 20%. The purpose was to better understand the MA constituent, explore the strain-induced martensitic transformation (SIMT) and austenitic decomposition by heat treatment with emphasis on its magnetic behavior. The transformation was accompanied by saturation magnetization measurements, compared with the mass density and X-ray diffraction. The plastic deformation or the heat treatment altered the saturation magnetization and the mass density in a manner consistent with the elimination of metastable retained austenite. The density method is sensible to measure phase transformations induced by strain. The data obtained shows a volumetric expansion of about 0.13%, corresponding to an amount of retained austenite of the original material of 3.2%, while the values obtained by magnetization saturation are 2.8% by hysteresigraph and 2.1% by VSM. By X-ray diffraction there is a clear drop in first peaks of austenite of the samples under deformation or heat treatment compared with the sample as-received.

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