Dissertations / Theses: 'Material motion'

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Geissinger, John Herman. "On Natural Motion Processing using Inertial Motion Capture and Deep Learning." Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/98523.

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Human motion collected in real-world environments without instruction from researchers - or natural motion - is an understudied area of the field of motion capture that could increase the efficacy of assistive devices such as exoskeletons, robotics, and prosthetics. With this goal in mind, a natural motion dataset is presented in this thesis alongside algorithms for analyzing human motion. The dataset contains more than 36 hours of inertial motion capture data collected while the 16 participants went about their lives. The participants were not instructed on what actions to perform and interacted freely with real-world environments such as a home improvement store and a college campus. We apply our dataset in two experiments. The first is a study into how manual material handlers lift and bend at work, and what postures they tend to use and why. Workers rarely used symmetric squats and infrequently used symmetric stoops typically studied in lab settings. Instead, they used a variety of different postures that have not been well-characterized such as one-legged lifting and split-legged lifting. The second experiment is a study of how to infer human motion using limited information. We present methods for inferring human motion from sparse sensors using Transformers and Seq2Seq models. We found that Transformers perform better than Seq2Seq models in producing upper-body and full-body motion, but that each model can accurately infer human motion for a variety of postures like sitting, standing, kneeling, and bending given sparse sensor data.
Master of Science
To better design technology that can assist people in their daily lives, it is necessary to better understand how people move and act in the real-world with little to no instruction from researchers. Personal assistants such as Alexa and Google Assistant have benefited from what researchers call natural language processing. Similarly, natural motion processing will be useful for everyday assistive devices like prosthetics and exoskeletons. Unscripted human motion in real-world environments - or natural motion - has been made possible with recent advancements in motion capture technology. In this thesis, we present data from 16 participants who wore a suit that captures accurate human motion. The dataset contains more than 36 hours of unscripted human motion data in real-world environments that is usable by other researchers to develop technology and advance our understanding of human motion. In addition, we perform two experiments in this thesis. The first is a study into how manual material handlers lift and bend at work, and what postures they tend to use and why. The second is a study into how we can determine what a person's body is doing with a limited amount of information from only a few sensors. This study could be useful for making commercial devices like smartphones, smartwatches, and smartglasses more valuable and useful.

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Wills, Joshua J. "Data analysis methods for motion segmentation and material reflectance." Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2006. http://wwwlib.umi.com/cr/ucsd/fullcit?p3211281.

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Thesis (Ph. D.)--University of California, San Diego, 2006.
Title from first page of PDF file (viewed June 7, 2006). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 104-112).

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Wong, Chun Lok. "Cardiac motion estimation with finite deformation and composite material models /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202004%20WONGCL.

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Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2004.
Includes bibliographical references (leaves 84-87). Also available in electronic version. Access restricted to campus users.

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Goleniewski, G. "Equations of motion for viscoelastic moving crack problems." Thesis, University of Bath, 1988. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383260.

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Bouman, Katherine L. (Katherine Louise). "Estimating the material properties of fabric through the observation of motion." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/84905.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2013.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 49-51).
We present a framework for predicting the physical properties of moving deformable objects observed in video. We apply our framework to analyze videos of fabrics moving under various unknown wind forces, and recover two key material properties of the fabric: stiffness and mass. We extend features previously developed to compactly represent static image textures to describe video textures such as fabric motion. A discriminatively trained regression model is then used to predict the physical properties of fabric from these features. The success of our model is demonstrated on a new database of fabric videos with corresponding measured ground truth material properties that we have collected. We show that our predictions are well correlated with both measured material properties and human perception of material properties. Our contributions include: (a) a method for predicting the material properties of fabric from a video, (b) a database that can be used for training and testing algorithms for predicting fabric properties containing RGB and RGBD videos of real videos with associated material properties and rendered videos of simulated fabric with associated model parameters, and (c) a perceptual study of humans' ability to estimate the material properties of fabric from videos and images.
by Katherine L. Bouman.
S.M.

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Williamson, Diana Michelle. "The degradation of cellulose acetate base motion picture film." Thesis, Manchester Metropolitan University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359295.

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The natural degradation of processed black and white cellulose acetate based 35mm motion picture film material has been investigated using 1H and 13C NMR spectroscopy. According to current standards only this material is considered to be an archival recording medium. It has been recognised that understanding the relationship between structure and physical properties would provide knowledge to help inhibit motion picture film degradation. A correlation between observed changes in molecular structure and physical property changes namely, % moisture regain, acidity and viscosity has been obtained. Results of these studies indicate that the primary mode of degradation is hydrolysis of ester groups leading to deacetylation of the C6 acetyl group in the polymer chain. On further deactylation, the C3 acetyl group is lost in preference to the C2 acetyl group. Therefore, it can be concluded that a decrease in viscosity retention and an increase in acidity concurs with deacetylation of the polymer chain. On this basis mechanisms of deacetylation would predominate since oxidative chain-scission would take place through the C2 acetyl group which is less accessible. NMR spectroscopy also reveals that the plasticisers, namely triphenyl phosphate and diethyl phthalate incorporated into cellulose acetate base, influence its stability. Under archival conditions the triphenyl phosphate plasticiser appears not to undergo degradation but becomes increasingly incompatible with the cellulose acetate base. Diethyl phthalate however was seen to degrade as the cellulose acetate base itself degrades. A more detailed understanding of the macromolecular structure of cellulose acetate based motion picture film has been obtained with the use of Molecular Modelling and Graphics studies using QUANTA software. This supports the NMR study indicating that the C6 and C3 acetyl groups are clearly more exposed in the polymer matrix and therefore, are more likely to be lost as hydrolysis of the polymer chain occurs. Modelling studies also supported reduced stability of the polymer in the presence of plasticisers. When plasticisers were docked within the polymer matrix distortions of the polymers chains were observed as chains were pushed apart and dihedral angles altered. The role of the emulsion in film degradation was also examined by electrophoresis. This separation of proteins has shown that under archival conditions, naturally aged gelatin emulsion layers show a decrease in molecular weight. This has been attributed to the acid catalysed deacetylation of the cellulose acetate base lowering the pH of the film and inducing hydrolysis of gelatin. Only when considerable amounts of acid have been evolved are changes to the emulsion observed. Finally, the effects of storage containers were characterised using viscosity and acidity measurements. Accelerated ageing studies at 50%RH 70°C to emulate archival storage conditions revealed that in the early stages of degradation polyethylene and polypropylene cans were more detrimental to film stability than the more traditional metal can. The plastic cans were shown to promote oxidative degradation of the film and polypropylene was shown to lead to higher levels of peroxide in films than polyethylene

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Dal, Taylan. "A dynamic behavior modeler for future inclusion into a multi-tasking motion planning system for material handling in construction." Thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-08142009-040314/.

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Pandharkar, Rohit (Rohit Prakash). "Hidden object doppler : estimating motion, size and material properties of moving non-line-of-sight objects in cluttered environments." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/67783.

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Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2011.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 111-117).
The thesis presents a framework for Non-Line-of-Sight Computer Vision techniques using wave fronts. Using short-pulse illumination and a high speed time-of-flight camera, we propose algorithms that use multi path light transport analysis to explore the environments beyond line of sight. What is moving around the corner interests everyone including a driver taking a turn, a surgeon performing laparoscopy and a soldier entering enemy base. State of the art techniques that do range imaging are limited by (i) inability to handle multiple diffused bounces [LIDAR] (ii) Wavelength dependent resolution limits [RADAR] and (iii) inability to map real life objects [Diffused Optical Tomography]. This work presents a framework for (a) Imaging the changing Space-time-impulse-responses of moving objects to pulsed illumination (b) Tracking motion along with absolute positions of these hidden objects and (c) recognizing their default properties like material and size and reflectance. We capture gated space-time impulse responses of the scene and their time differentials allow us to gauge absolute positions of moving objects with knowledge of only relative times of arrival (as absolute times are hard to synchronize at femto second intervals). Since we record responses at very short time intervals we collect multiple readings from different points of illumination and thus capturing multi-perspective responses allowing us to estimate reflectance properties. Using this, we categorize and give parametric models of the materials around corner. We hope this work inspires further exploration of NLOS computer vision techniques.
by Rohit Pandharkar.
S.M.

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Frick, Urszula. "Culture in motion : Material culture in the inventory of Catherine Jagiellon’s dowry from 1562 and its analysis from culture transfer perspective." Thesis, Uppsala universitet, Konstvetenskapliga institutionen, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-387408.

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On the 4th of October 1562, the Polish princess Catherine Jagiellon married the Swedish prince and duke of Finland Johan Vasa. Leaving Poland, Catherine Jagiellon was equipped with a very rich dowry and followed by an entourage of nearly 50 people. The objective of this study is to investigate the objects and people surrounding the newly wedded 16th century princess and asses if the document mirrors the complex cultural interactions of the early modern world. The analysis of the inventory is carried out using two theoretical approaches: material culture and culture transfer. The study is constructed in two parts. The first part focuses on the analysis of the sections of the inventory following the order of the document. If possible, the objects are mapped, their history is traced through the sources, their appearance and function are discussed. The examination of the members of the court is also carried out. With the deepened analysis of the inventory as a basis, the second part of the study is dedicated to the search of culture hybridization markers in described artefacts, people, practices as well as the language of the document itself. With the result of this investigation, the author is able to pinpoint the complex international cultural processes that were occurring in an early modern world.

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Ginach, Erich Lie. "Discurso, silenciamento e alteração material no filme Deus e Brasileiro." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/268930.

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Orientador: Suzy Lagazzi-Rodrigues
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Estudos da Linguagem
Made available in DSpace on 2018-08-04T17:45:59Z (GMT). No. of bitstreams: 1 Ginach_ErichLie_M.pdf: 697552 bytes, checksum: e595415052bb956aa6aa6807119da219 (MD5) Previous issue date: 2005
Résumé: Cette recherche, prenant comme référentiel théorique l¿Analyse du discours de la ligne matérialiste, avec le film Dieu est Brésilien s¿est proposée à apporter à la pratique analytique la matérialité du cinéma, en prenant comme approche les scènes dans lesquelles l¿accord entre les interventions divines et les changements filmiques sont traversés par le silence. Dans ces extraits de l¿intrigue, Dieu entre en contact direct avec les humains, produisant des interventions de différents ordres. Les changements filmiques marqués sont caractérisés par caméra lente ou rapide, introduction d¿effet visuel et sonore, suppression dês bruits et remplissage de l¿espace sonore avec de la musique. Cependant, deux diferentes relations de sens sont distingées dans le corpus: d¿un côté par des démonstrations de puissance divine face à l¿insolence des mortels Taoca et Quinca das Mulas, un effet disjonctif est là produit; d¿un autre côté, les interventions pacifiques et humanisées de Dieu dans lês scènes avec la jeune femme Madá produisent un effet conjonctif. Dans les deux groupes de relations certains sens ne sont formulées pas, ce qui se marque à la surface textuelle sous la forme de suspension de l¿interlocution des personnages. De sorte que la nature du silence dans l¿ensemble de scènes soit comprise, il a été nécessaire de renvoyer les formulations ¿ comprenant les images, les gestes, la musique, lês bruits, les mots ¿ aux interdiscours ou mémoire discursive. Ce travail a montré des déplacements de sens dans la position du devin dans la formation discursive religieuse
Resumo: Esta pesquisa, tomando como referencial teórico a Análise de Discurso de linha materialista, com o filme Deus é Brasileiro se dispôs a trazer para a prática analítica a materialidade do cinema, tendo como enfoque cenas nas quais é regular a concomitância entre intervenções divinas e alterações fílmicas atravessadas de silenciamentos. Nesses trechos do enredo, Deus entra em contato direto com os humanos, produzindo intervenções de diferentes ordens. As alterações fílmicas aí marcadas se caracterizam por câmera rápida ou lenta, introdução de efeitos visuais e sonoros, supressão de ruídos e preenchimento do espaço sonoro por música. No entanto, distinguem-se no corpus dois recortes, definidos segundo diferentes relações de sentidos inscritas nas cenas: de um lado, com as demonstrações do poder divino diante da insolência dos mortais Taoca e Quinca das Mulas, produz-se um efeito disjuntivo; de outro, as intervenções pacíficas e humanizadas de Deus nas cenas com a moça Madá produzem um efeito conjuntivo. Em ambos os recortes certos sentidos são silenciados, o que se marca na superfície textual sob a forma da suspensão da interlocução dos personagens. Para que se compreendesse a natureza do processo de silenciamento no conjunto de cenas foi preciso remeter as formulações ¿ incluindo as imagens, os gestos, a música, os sons, as palavras ¿ ao interdiscurso ou memória discursiva. Este trabalho mostrou deslizes de sentidos na posição do divino na formação discursiva religiosa
Mestrado
Mestre em Linguística

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Braun, Michael Rainer. "Characterization of nonlinearity parameters in an elastic material with quadratic nonlinearity with a complex wave field." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26566.

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Thesis (M. S.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2009.
Committee Chair: Jacobs, Laurence; Committee Co-Chair: Qu, Jianmin; Committee Member: DesRoches, Reginald. Part of the SMARTech Electronic Thesis and Dissertation Collection.

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Piovano, Paulo. "Evolution and Regularity Results for Epitaxially Strained Thin Films and Material Voids." Research Showcase @ CMU, 2012. http://repository.cmu.edu/dissertations/96.

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In this dissertation we study free boundary problems that model the evolution of interfaces in the presence of elasticity, such as thin film profiles and material void boundaries. These problems are characterized by the competition between the elastic bulk energy and the anisotropic surface energy. First, we consider the evolution equation with curvature regularization that models the motion of a two-dimensional thin film by evaporation-condensation on a rigid substrate. The film is strained due to the mismatch between the crystalline lattices of the two materials and anisotropy is taken into account. We present the results contained in [62] where the author establishes short time existence, uniqueness and regularity of the solution using De Giorgi’s minimizing movements to exploit the L2 -gradient flow structure of the equation. This seems to be the first analytical result for the evaporation-condensation case in the presence of elasticity. Second, we consider the relaxed energy introduced in [20] that depends on admissible pairs (E, u) of sets E and functions u defined only outside of E. For dimension three this energy appears in the study of the material voids in solids, where the pairs (E, u) are interpreted as the admissible configurations that consist of void regions E in the space and of displacements u of the atoms of the crystal. We provide the precise mathematical framework that guarantees the existence of minimal energy pairs (E, u). Then, we establish that for every minimal configuration (E, u), the function u is C 1,γ loc -regular outside an essentially closed subset of E. No hypothesis of starshapedness is assumed on the voids and all the results that are contained in [18] hold true for every dimension d ≥ 2.

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Miranda, Moltedo Diego I. "Propuesta de material audiovisual para el desarrollo de un modelo experimental de Workshop sobre Motion Graphics, en la Escuela de Diseño de la Universidad de Chile." Tesis, Universidad de Chile, 2012. http://repositorio.uchile.cl/handle/2250/100477.

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En el presente proyecto, pretendo abarcar un área del Diseño que no ha sido profundamente estudiada en Chile, y que su desarrollo en la actualidad es, muchas veces, asumida por diseñadores gráficos que han buscado fuera de sus escuelas las herramientas necesarias para ingresar a un mercado que crece junto a los medios de comunicación. Con las nuevas tecnologías y tendencias aplicadas en el Diseño Gráfico, se han abierto nuevas oportunidades profesionales, sobre todo en el ámbito audiovisual. Gracias al crecimiento del mercado de la publicidad y la televisión, el Motion Graphics ha logrado consolidarse como un área específica de desarrollo del Diseño, la que ofrece múltiples posibilidades expresivas. Bajo este contexto, sería necesario incluir espacios educativos, que entreguen las he-rramientas necesarias a los estudiantes para desenvolverse en un mercado laboral cada día más exigente. Se propone desarrollar una unidad de aprendizaje en torno al Motion Graphics, que considere una experiencia significativa para el usuario y que sirva como complemento a la enseñanza del diseño multimedia en la Universidad de Chile.

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Kundu, Sangeeta J. "Facial strain maps as a biometric source." [Tampa, Fla.] : University of South Florida, 2005. http://purl.fcla.edu/fcla/etd/SFE0001280.

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Loget, Gabriel. "Electric field-generated asymmetric reactivity : from materials science to dynamic systems." Thesis, Bordeaux 1, 2012. http://www.theses.fr/2012BOR14572/document.

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L’électrochimie bipolaire est un phénomène générant une réactivité asymétrique à la surface d’objets conducteurs, sans contact électrique direct. Ce concept est basé sur le fait que lorsqu’un objet conducteur est localisé dans un champ électrique, il se polarise. Par conséquent, une différence de potentiel est générée entre ses deux extrémités, et peut être utilisée pour induire des réactions redox localisées. Dans cette thèse, l’utilisation de l’électrochimie bipolaire pour la science des matériaux et pour la locomotion d’objets est présentée.Jusqu’à présent, la plupart des méthodes ou procédés utilisés pour générer des objets asymétriques,appelés aussi objets « Janus », nécessitent l’introduction d’une interface pour briser la symétrie. Nous avons développé une nouvelle approche basée sur l’électrodéposition bipolaire pour générerce type d’objet en grande quantité. Grâce à cette technologie différents matériaux tels que des métaux, des polymères et des semi‐conducteurs ont pu être déposés sur diverses particulesconductrices. Il a été aussi démontré que l’électrochimie bipolaire pouvait être utilisée pour lamicrostructuration de substrats conducteurs.Nous avons induit des mouvements à des objets conducteurs en exploitant le phénomèned’électrochimie bipolaire. Certains objets Janus synthétisés par l’approche précédente ont pu être utilisés comme micronageurs. La brisure de symétrie qui est générée par l’électrochimie bipolaire peut être aussi utilisée directement pour générer un mouvement de particules isotropes. En employant ce concept, nous avons pu provoquer des mouvements de translation, rotation et lévitation pour des particules de carbones ou métalliques
The phenomenon of bipolar electrochemistry generates an asymmetric reactivity on the surface ofconductive objects in a wireless manner. This concept is based on the fact that when a conducingobject is placed in an electric field, it gets polarized. Consequently, a potential difference appearsbetween its two extremities, that can be used to drive localized redox reactions. In the presentthesis, bipolar electrochemistry was used for material science and the locomotion of objects.So far, the majority of methods and processes used for the generation of asymmetric objects, alsocalled “Janus” objects, is based on using interfaces to break the symmetry. We developed a newapproach based on bipolar electrodeposition for generating this type of objects in the bulk. Using thistechnology, various materials like metals, polymers and semiconductors could be deposited ondifferent types of conducting particles. We also showed that bipolar electrochemistry can be used forthe microstructuration of conducting substrates.Motion generation by bipolar electrochemistry has also been demonstrated. Some of the Janusobjects synthesized by the previous approach can be used as microswimmers. The asymmetricreactivity that is induced by bipolar electrochemistry can also be used directly to generate motion ofnon‐hybrid objects. With this concept we induced translations, rotations and levitations of carbonand metal particles

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Murphree, Hyon Joo Yoo. "Cowboys, Postmodern Heroes, and Anti-heroes: The Many Faces of the Alterized White Man." Thesis, University of North Texas, 2000. https://digital.library.unt.edu/ark:/67531/metadc2620/.

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This thesis investigates how hegemonic white masculinity adopts a new mode of material accumulation by entering into an ambivalent existence as a historical agent and metahistory at the same time and continues to function as a performative identity that offers a point of identification for the working class white man suggesting that bourgeois identity is obtainable through the performance of bourgeois ethics. The thesis postulates that the phenomenal transitions brought on by industrialization and deindustrialization of 50's through 90's coincide with the representational changes of white masculinity from paradigmatic cowboy incarnations to the postmodern action heroes, specifically as embodied by Bruce Willis. The thesis also examines how postmodern heroes' "intero-alterity" is further problematized by antiheroes in Tim Burton's films.

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Yang, Lei. "Current induced domain wall motion : analysis and simulation /." View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?MATH%202008%20YANG.

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Brufau, Penella Jordi. "Smart materials for microrobotics motion control and power harvesting." Doctoral thesis, Universitat de Barcelona, 2009. http://hdl.handle.net/10803/1512.

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This thesis focuses on the use of smart materials in microrobotic applications. The development of materials with the capabilities to mechanically respond to electrical stimuli or, at the same time, to electrically respond to mechanical stimuli, has entailed the microrobotics rapid evolution. Along this thesis the use of three smart materials families in the filed of microrobotics is studied. The materials used are the piezoelectric ceramics, the piezoelectric polymers and the ionic polymers metal composites IPMC. The similitude in the way they respond to external stimuli has motivated this study. The three materials respond with an induced mechanical strain under the application of an electric field and respond with an induced electrical charge variation when a mechanical pressure is applied. Although these materials respond similarly, their application in microrobotic systems entails different problems. In this thesis their use in different applications is studied and the problems enclosed with their use are treated.
First of all in this thesis the use of piezoelectric polymers and ionic polymers as materials for motion control of microrobots is studied. Their flexibility opens the door to new applications for microrobot systems as is the case of biomimetics. The first application regards the use of piezoelectric polymers in insect-like mm3 microrobot. The microrobot is composed with three legs and one antenna or tool for object collision based on piezoelectric polymers. The object collision tool is used as a sensor for motion control to avoid collisions with other objects. The work presented consists on the development of theoretical models to predict the motion of he leg and the tool of the microrobot. The second application regards the development of a control system for controlling the motion of an ionic polymer IPMC underwater. It is difficult to obtain physical models that describe the motion of these materials, thus it is important to design control strategy to work with IPMCs. Furthermore in this thesis, the problem of manufacturing electrodes for IPMC is also treated.
In the second part of the thesis the use of piezoelectric ceramics to harvest power from mechanical vibrations is studied. Piezoelectric ceramics have higher energy densities compared with other methods for power harvesting from vibrations. In comparison with the piezoelectric polymers, the piezoelectric ceramics produce voltages and current levels more acceptable. From the study performed in this thesis the conditions for a maximum power generation are obtained and an optimum electronic circuit for energy storage and management is designed. At the end of the thesis the capabilities to harvest power using ionic polymers are studied.

KEY WORDS: Smart Materials, Microrobotic, Harvesting, Motion Control, Fonic Polimer, FPMC Piezoelectric, Modelling
Aquesta tesis es centra en l'ús de materials "smart" o intel·ligents en aplicacions de microrobòtica. Al llarg de la tesi treballem amb tres famílies de materials "smart" diferents: les ceràmiques piezoelèctriques, els polímers piezoelèctrics i els polímers iònics coneguts com Ionic Polymer Metal Composites (IPMC). Aquests materials tenen en comú que al aplica'ls-hi un camp elèctric pateixen una deformació mecànica mentre que si els sotmetem a una deformació mecànica, aquests materials pateixen una variació en la seva càrrega elèctrica interna. Degut a aquestes propietats aquests materials poden ser utilitzats com a sensors o com a actuadors.
A la primera part de la tesi estudiem l'ús dels polímers piezoelèctrics i dels polímers iònics per al control del moviment dels microrobots. La primera aplicació que es presenta tracta d'un microrobot de dimensions mm3 que utilitza els polímers piezoelèctrics com a potes i com a sensors de col·lisió. Tot seguit presentem una aplicació a on els IPMCs són utilitzats com a microposicionadors treballant sota de l'aigua.
A la segona part de la tesis estudiem la viabilitat d'utilitzar les ceràmiques piezoelèctriques i els polímers iònics per a generar energia a partir de vibracions mecàniques residuals ambientals. L'estudi presentat determina els nivells de potència generats i les condicions òptimes per a la generació de la màxima potencia.

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Sivilli, Robert. "Vision-Based Testbeds for Control System Applicaitons." Master's thesis, University of Central Florida, 2012. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5504.

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In the field of control systems, testbeds are a pivotal step in the validation and improvement of new algorithms for different applications. They provide a safe, controlled environment typically having a significantly lower cost of failure than the final application. Vision systems provide nonintrusive methods of measurement that can be easily implemented for various setups and applications. This work presents methods for modeling, removing distortion, calibrating, and rectifying single and two camera systems, as well as, two very different applications of vision-based control system testbeds: deflection control of shape memory polymers and trajectory planning for mobile robots. First, a testbed for the modeling and control of shape memory polymers (SMP) is designed. Red-green-blue (RGB) thresholding is used to assist in the webcam-based, 3D reconstruction of points of interest. A PID based controller is designed and shown to work with SMP samples, while state space models were identified from step input responses. Models were used to develop a linear quadratic regulator that is shown to work in simulation. Also, a simple to use graphical interface is designed for fast and simple testing of a series of samples. Second, a robot testbed is designed to test new trajectory planning algorithms. A template-based predictive search algorithm is investigated to process the images obtained through a low-cost webcam vision system, which is used to monitor the testbed environment. Also a user-friendly graphical interface is developed such that the functionalities of the webcam, robots, and optimizations are automated. The testbeds are used to demonstrate a wavefront-enhanced, B-spline augmented virtual motion camouflage algorithm for single or multiple robots to navigate through an obstacle dense and changing environment, while considering inter-vehicle conflicts, obstacle avoidance, nonlinear dynamics, and different constraints. In addition, it is expected that this testbed can be used to test different vehicle motion planning and control algorithms.
M.S.A.E.
Masters
Mechanical and Aerospace Engineering
Engineering and Computer Science
Aerospace Engineering; Space Systems Design and Engineering

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Kuechler, Sebastian. "Wave Propagation in an Elastic Half-Space with Quadratic Nonlinearity." Thesis, Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/19823.

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This study investigates wave propagation in an elastic half-space with quadratic nonlinearity due to a line load on the surface. The consideration of this problem is one of the well known Lamb problems. Even since Lamb's original solution, numerous investigators have obtained solutions to many different variants of the Lamb problem. However, most of the solutions existing in the current literature are limited to wave propagation in a linear elastic half-space. In this work, the Lamb problem in an elastic half-space with quadratic nonlinearity is considered. For this, the problem is first formulated as a hyperbolic system of conservation laws, which is then solved numerically using a semi-discrete central scheme. The numerical method is implemented using the package CentPack. The accuracy of the numerical method is first studied by comparing the numerical solution with the analytical solution for a half-space with linear response (the original Lamb's problem). The numerical results for the half-space with quadratic nonlinearity are than studied using signal-processing tools such as the fast Fourier transform (FFT) in order to analyze and interpret any nonlinear effects. This in particular gives the possibility to evaluate the excitation of higher order harmonics whose amplitude is used to infer material properties. To quantify and compare the nonlinearity of different materials, two parameters are introduced; these parameters are similar to the acoustical nonlinearity parameter for plane waves.

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21

Larsson, Ashley Ian. "Mathematical aspects of wave theory for inhomogeneous materials /." Title page, table of contents and summary only, 1991. http://web4.library.adelaide.edu.au/theses/09PH/09phl334.pdf.

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22

Keller, Trevor. "Bias in polycrystal topology caused by grain boundary motion by mean curvature." Thesis, Rensselaer Polytechnic Institute, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3705608.

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During heat treatment of polycrystalline materials, grain shape affects the rate of grain growth. In 2-D, the von Neumann-Mullins Law requires grains with fewer than six edges to shrink, greater than six edges to grow, and hexagonal grains to be stable regardless of edge lengths or curvatures. The 3-D analogue, described by the MacPherson-Srolovitz relation, does not explicitly depend on any topological feature (number of faces, edges, or vertices), yet there is bias in the observed grain topologies in 3-D metal polycrystals. In order to investigate this bias and determine its origins, numerical simulations of ideal polycrystalline materials, characterization of topologies, and comparisons to possible polyhedral shapes were performed.

Normal grain growth in polycrystalline materials is characterized by a self-similar distribution of topological properties: the average grain area increases with heat treatment time, but the average number of faces per grain remains constant. Therefore, distributions of the number of faces per grain are commonly reported characteristics of polycrystals. To investigate bias in grain topologies, the number of edges per face on each grain in the polycrystal was extracted, then the standard deviation of this quantity was computed for each grain. For grains resembling Platonic solids with equal numbers of edges on each face, such as the Platonic tetrahedron, hexahedron, and dodecahedron, this quantity is zero. In typical grains with more diverse faces, the standard deviation increases. The average, upper, and lower bound of standard deviations possible for all polyhedra with a given number of faces were determined by enumerating each using a graph theory-based code, plantri. Several polycrystalline datasets were then obtained and analyzed: two synthetic, two simulated grain growth, and one experimental reconstruction of titanium. The polycrystals all exhibited lower averages of the standard deviation of edges per face than the enumerated polyhedra, demonstrating bias. Specifically, the bias in grain growth favors more "regular" topologies, with a smaller spread in the number of edges per face than would occur at random.

One dataset, a synthetic microstructure with flat edges and faces, was biased more weakly than the rest. The remaining four datasets involved motion by mean curvature, the fundamental mechanism of grain growth, under which interfaces move toward their center of curvature with velocity proportional to that curvature: sharply curved faces move faster than more gently curved ones, and flat faces move not at all. To satisfy force balance at the vertices, three-edged faces in polycrystals become highly curved and quickly collapse during grain growth, but the laws of topology require that grains with between ten and sixteen faces have five edges per face, on average. This span covers the median and mean number of faces in polycrystalline grain populations. Therefore, as three-edged faces collapse, faces with more than 5 edges must also lose edges to maintain grain boundary network connectivity.

By changing the physics of grain growth to decrease edge and face curvature, the population of three-edged faces should increase, with the standard deviation in edges per face increasing proportionally. To test this hypothesis, a phase-field model of grain growth was implemented with lower mobility on triple junctions than on other features. This approach, known as a "vertex drag" model in 2-D, tends to straighten grain edges. From large-scale 2-D simulations, vertex mobility 100x lower than the edge mobility was found to increase the relative proportion of 3-edged grains by 25%. While the effect is small in magnitude, this result supports motion by mean curvature as the root cause of bias in polycrystalline grain topology.

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Rios, Jorge Machado. "Temperature/motion feedback loop for fast firing." Master's thesis, Universidade de Aveiro, 2012. http://hdl.handle.net/10773/10062.

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Mestrado em Engenharia Mecânica
Durante a sinterização de sistemas policristalinos ocorrem processos às partículas do material entre os quais densificação, engrossamento do grão, controlo da porosidade, segregação das partículas entre outros. Estes processos resultam num de três transportes de mecanismos condensação/evaporação na superfície, pela difusão nos limites do grão e pela difusão da látice. A microestrutura final pode ser modificada ao forçar um específico fenómeno a ser predominante sobre os restantes durante o processo de sinterização. Por exemplo, o processo de sinterização por aquecimento rápido representa um procedimento onde o perfil Temperatura-Tempo (T-t) é alterado rapidamente para atingir uma Temperatura (T) onde a densificação predominante sobre o crescimento do grão. Desta maneira é possível obter um tamanho de grão mínimo mantendo no entanto um grau de densificação elevado em materiais policristalinos. O trabalho aqui apresentado irá projectar e construir um dispositivo mecânico que permita introduzir amostras cerâmicas dentro de um forno com uma rampa de aquecimento controlada, enquanto tendo um feedback constante da posição e temperatura das amostras.
The processes that occur during sintering of polycrystalline systems, are those of particle necking, densification, grain coarsening, porosity control, and segregation. These processes result from three mass transport mechanisms: surface condensation/evaporation, grain boundary diffusion, and lattice diffusion. The final microstructure can be varied by forcing a specific phenomenon to predominate over the others during the sintering process. For example, the fast-firing process represents a sintering procedure where the temperature– time (T–t) profile is altered to rapidly reach the T regime where densification dominates over grain growth. In this way, a small grain size can be maintained while still offering a high densification of polycrystalline materials. Therefore, the current work will design and build a mechanical device, to introduce ceramic samples into a furnace at a controlled ramp rate, with an instantaneous temperature/motion feedback loop.

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24

Marioni, Miguel Augusto 1971. "Pulsed magnetic field-induced twin boundary motion on Ni-Mn-Ga." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/7965.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2003.
Includes bibliographical references (p. 201-210).
The magnetic field-induced strain (ferromagnetic shape memory effect - FSME) in Ni-Mn-Ga was first reported in 1996 by Ullakko et al. Since then, up to 6% FSME in single-crystal tetragonal-Ni-Mn-Ga samples has been observed in static fields, and up to 3% at 500 Hz. The present work demonstrates 6% FSME of a Ni-Mn-Ga single crystal of 5 x 5 x 9.85 mm³ in 200[mu]s is by application of a magnetic field pulse. It proves the feasibility of actuators operating at frequencies above of 1 kHz at room temperature for this geometry, and that the actuation can be accomplished using compact, air-core Helmholtz coils operated in pulsed mode. The eddy-current attenuation of 620 [mu]s-long pulses in the samples tested is small, reducing the need for lamination. The field-induced extension does not begin at the same time as the field. Part of the delay is the time that the field takes to reach the threshold level for actuation. The mass-inertia of the sample results in an additional delay, which depends on the position and number of mobile twin-boundaries in the crystal. The delay is maximum for a single twin-boundary moving from the fixed to the free end of the crystal. For several twin-boundaries distributed uniformly throughout the crystal the delay is shorter. The peak acceleration observed is 50 ± 10 m/s². For typical twin-boundary energies of the order of 40 erg/cm² homogeneous nucleation of partial dislocations was found to be unlikely. Accordingly, twin-boundaries must be seeded through stress. High-speed video images and photographs have demonstrated that field-induced twin-boundary motion is not uniform along a Ni-Mn-Ga single crystal. Twin boundaries stop when they reach certain positions of the crystal, and remain pinned unless the field is increased. The observed scatter in the data of field-induced extension is related to the existence of pinning sites. The maximum rate of extension can be expressed as an exponential function of the driving force, andreaches 6 m/s for saturated driving force in the present case.
by Miguel Augusto Marioni.
Ph.D.

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25

Lübben, Michael [Verfasser]. "Redox Processes at Interfaces and Ionic Motion in Resistively Switching Materials / Michael Lübben." München : Verlag Dr. Hut, 2020. http://d-nb.info/1219475300/34.

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26

Bizon, Christopher Andrew. "Simulations of wave patterns in oscillated granular media /." Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.

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27

Morales, Polar Martha Luz. "Memoria y materia." Bachelor's thesis, Pontificia Universidad Católica del Perú, 2019. http://hdl.handle.net/20.500.12404/14345.

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28

Zhang, Kechun Dougherty Dennis A. Tirrell David A. "Engineering protein-based materials through coiled-coil motifs /." Diss., Pasadena, Calif. : California Institute of Technology, 2007. http://resolver.caltech.edu/CaltechETD:etd-01232007-144117.

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29

Samuila, Adrian-Paun. "Charge et trajectoires des particules dans les séparateurs électrostatiques." Université Joseph Fourier (Grenoble), 1997. http://www.theses.fr/1997GRE10090.

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L'objectif de ce travail a ete d'ameliorer la comprehension des phenomenes physiques mis en jeu dans les separateurs electrostatiques a electrode cylindrique tournante. Les etudes ont porte essentiellement sur les mecanismes de charge des particules et sur les facteurs qui influencent les trajectoires de celles-ci dans le champ electrique de ces installations. Une methode originale, basee sur l'analyse numerique du champ electrique, est proposee pour le calcul de la charge acquise en champ ionise par des particules isolantes de forme et de dimensions variees posees sur une electrode ou a proximite de celle-ci. Les predictions theoriques sont confirmees par des mesures effectuees sur une installation experimentale qui modelise les conditions de charge specifiques aux separateurs electrostatiques et qui permet une evaluation de l'efficacite de divers types d'electrodes ionisantes. Des experiences realisees avec un autre dispositif montrent que cette efficacite est liee a l'intensite du courant genere par l'electrode et a l'uniformite de sa distribution a la surface de l'electrode collectrice. La these ameliore aussi le modele numerique utilise pour l'etude du comportement des particules conductrices en champ harmonique ou ionise et pour le calcul de leurs trajectoires dans les separateurs electrostatiques a electrode cylindrique tournante. Le modele a ete valide par des experiences realisees dans diverses configurations d'electrodes. Les resultats de ces etudes contribuent au developpement de quelques applications industrielles. La these montre la possibilite d'utiliser un separateur electrostatique a zone etendue de champ ionise pour la recuperation du laiton des dechets industriels. Diverses solutions sont analysees pour recycler les materiaux isolants et les metaux provenant des dechets de cables electriques. Enfin, une technologie nouvelle est proposee pour la purification des concentres de mica.

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30

Perbring, Anna, and Karin Åkesson. "”Konsten är att sovra i allt material” : om val av material och aktiviteter i ämnet svenska som andraspråk." Thesis, Högskolan i Borås, Institutionen för Pedagogik, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-19885.

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BAKGRUND: I vår bakgrund redogör vi för den tidigare forskning som bedrivits kring fysiskt undervisningsmaterial i ämnet. Vår teoretiska ram utgörs av Cummins modell för andraspråksinlärning samt Vygotskijs sociokulturella förhållningssätt vilka båda ligger till grund för vår resultatdiskussion.SYFTE: Syftet med vår undersökning är att med utgångspunkt i klassrummets konkreta material studera undervisningssituationer i ämnet svenska som andraspråk, samt undersöka vilka motiv lärare anger för sina val av material och val av aktiviteter.METOD: För att nå studiens syfte använde vi oss utav observationer och kvalitativa intervjuer. I vår undersökning ingår tre lärare på olika skolor som undervisar i ämnet svenska som andraspråk.RESULTAT: I vår undersökning fann vi att lärarna arbetade med ett varierat material och olika aktiviteter i sin undervisning utan att vara styrda av läroboken. Gemensamt för de tre lärarna var att de arbetade med skönlitteratur, läsförståelse och ordkunskap. Resultatet visade också att lärarnas motiv till det material de använde ofta grundade sig på en ambition av anpassning till elevernas tidigare kunskaper och vardagliga liv.

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31

Webber, Kyle Grant. "Effect of Domain Wall Motion and Phase Transformations on Nonlinear Hysteretic Constitutive Behavior in Ferroelectric Materials." Diss., Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/22695.

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The primary focus of this research is to investigate the non-linear behavior of single crystal and polycrystalline relaxor ferroelectric PMN-xPT and PZN-xPT through experimentation and modeling. Characterization of single crystal and polycrystalline specimens with similar compositions was performed. These data give experimental insight into the differences that may arise in a polycrystal due to local interaction with inhomogeneities. Single crystal specimens were characterized with a novel experimental technique that reduced clamping effects at the boundary and gave repeatable results. The measured experimental data was used in conjunction with electromechanical characterizations of other compositions of single crystal specimens with the same crystallographic orientation to study the compositional effects on material properties and phase transition behavior. Experimental characterization provided the basis for the development of a model of the continuous phase transformation behavior seen in PMN-xPT single crystals. In the modeling it is assumed that a spatial chemical and structural heterogeneity is primarily responsible for the gradual phase transformation behavior observed in relaxor ferroelectric materials. The results are used to simulate the effects of combined electrical and mechanical loading. An improved rate-independent micromechanical constitutive model based on the experimental observations of single crystal and polycrystalline specimens under large field loading is also presented. This model accounts for the non-linear evolution of variant volume fractions. The micromechanical model was calibrated using single crystal data. Simulations of the electromechanical behavior of polycrystalline ferroelectric materials are presented. These results illustrate the effects of non-linear single crystal behavior on the macroscopic constitutive behavior of polycrystals.

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32

Age, Alessander Henrique. "Musica no alvo : um estudo da musica publicitaria nas decadas de 1950 e 1960 no Brasil." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/284761.

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Orientador: Claudiney Rodrigues Carrasco
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Artes
Made available in DSpace on 2018-08-07T18:01:31Z (GMT). No. of bitstreams: 1 Age_AlessanderHenrique_M.pdf: 860700 bytes, checksum: bf90f16240cbd731e21ec17603d9de3f (MD5) Previous issue date: 2006
Resumo: A presente dissertação de mestrado aborda a inserção da música na linguagem publicitária e sua influência no processo de comunicação. Através de um levantamento histórico e analítico, procura-se entender como a música atuou dentro do contexto publicitário nas décadas de 1950 e 1960. Para tanto, com base na teoria da publicidade e música de cinema, foram analisados filmes publicitários e anúncios de rádio produzidos nas cidades de São Paulo e Rio de Janeiro nesse período
Mestrado
Mestre em Música

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33

Houton, Kelly Ann. "Use of heterocomplementary hydrogen bonding motifs for supramolecular materials chemistry." Thesis, University of Leeds, 2015. http://etheses.whiterose.ac.uk/9217/.

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Hydrogen bonding is one of the most useful of the non-covalent interactions. Highly directional and easily tuneable, the strength of hydrogen bonded arrays enable controlled assembly of macromolecular structures. Because association can be designed to be selective, self-assembly involving low-molecular-weight amides and ureas has been expanded to higher order polymeric structures, so called ‘supramolecular polymers’. Chapter 1 introduces and develops upon the current themes of research in small-molecule hydrogen bonding, and the subsequent application towards the assembly of supramolecular polymers, in particular polyurethanes. The Wilson group is focused on the development of orthogonal recognition pathways, and their future application in the controlled assembly of polymers. The work presented in this thesis, therefore focuses on the development of self-sorting cascades- where molecules capable of hydrogen bonding have defined partners at specific stages of the cascade. Selecting two heterocomplementary hydrogen bonding arrays, and using them to form supramolecular polymers then advance this. Chapter 2 introduces the design and investigation of these self-sorting pathways involving hydrogen bonding arrays reported both in the literature and from within the Wilson group. The application of two of these hydrogen bonding motifs to assemble supramolecular polyurethanes is described in Chapter 3. The effect of the thermal history of supramolecular polyurethanes is then investigated, highlighting the change in response to thermal stimuli dependent on previous processing and treatment. The latter part of Chapter 3 introduces a ‘toolbox’ for supramolecular chemists, whereby components of the supramolecular polymer are changed systematically to gauge effect on subsequent mechanical properties. The synthetic route to supramolecular polymers is then discussed in Chapter 4, and the evolution of a solvent-free route to this particular class of polyurethanes is realised.

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34

Smidt, Tess Eleonora. "Toward the Systematic Design of Complex Materials from Structural Motifs." Thesis, University of California, Berkeley, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10817362.

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With first-principles calculations based on density functional theory, we can predict with good accuracy the electronic ground state properties of a fixed arrangement of nuclei in a molecule or crystal. However, the potential of this formalism and approach is not fully utilized; most calculations are performed on experimentally determined structures and stoichiometric substitutions of those systems. This in part stems from the difficulty of systematically generating 3D geometries that are chemically valid under the complex interactions existing in materials. Designing materials is a bottleneck for computational materials exploration; there is a need for systematic design tools that can keep up with our calculation capacity. Identifying a higher level language to articulate designs at the atomic scale rather than simply points in 3D space can aid in developing these tools.

Constituent atoms of materials tend to arrange in recognizable patterns with defined symmetry such as coordination polyhedra in transition metal oxides or subgroups of organic molecules; we call these structural motifs. In this thesis, we advance a variety of systematic strategies for understanding complex materials from structural motifs on the atomic scale with an eye towards future design.

In collaboration with experiment, we introduce the harmonic honeycomb iridates with frustrated, spin-anisotropic magnetism. At the atomic level, the harmonic honeycomb iridates have identical local geometry where each iridium atom octahedrally coordinated by oxygen hosts a J_eff = 1/2 spin state that experiences interactions in orthogonal spin directions from three neighboring iridium atoms. A homologous series of harmonic honeycomb can be constructed by changing the connectivity of their basic structural units.

Also in collaboration with experiment, we investigate the metal-organic chalcogenide assembly [AgSePh]∞ that hosts 2D physics in a bulk 3D crystal. In this material, inorganic AgSe layers are scaffolded by organic phenyl ligands preventing the inorganic layers from strongly interacting. While bulk Ag₂Se is an indirect band gap semiconductor, [AgSePh]∞ has a direct band gap and photoluminesces blue. We propose that these hybrid systems present a promising alternative approach to exploring and controlling low-dimensional physics due to their ease of synthesis and robustness to the ambient environment, contrasting sharply with the difficulty of isolating and maintaining traditional low-dimensional materials such as graphene and MoS₂.

Automated density functional theory via high throughput approaches are a promising means of identifying new materials with a given property. We automate a search for ferroelectric materials by integrating density functional theory calculations, crystal structure databases, symmetry tools, workflow software, and a custom analysis toolkit. Structural distortions that occur in the structural motifs of ferroelectrics give rise to a switchable spontaneous polarization. In ferroelectrics lattice, spin, and electronic degrees of freedom couple leading to exotic physical phenomena and making them technologically useful (e.g. non-volatile RAM).

We also propose a new neural network architecture that encodes the symmetries of 3D Euclidean space for learning the structural motifs of atomic systems. We describe how these networks can be used to speed up important components of the computational materials discovery pipeline and generate hypothetical stable atomic structures.

Finally, we conclude with a discussion of the materials design tools deep learning may enable and how these tools could be guided by the intuition of materials scientists.

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35

McKean, Christopher R. "Relative contributions of the lumbar spine and pelvis to trunk motion during sagittal plane manual materials handling." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ40429.pdf.

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36

Darvishi, Kamachali Reza [Verfasser], Ingo [Gutachter] Steinbach, and Dierk [Gutachter] Raabe. "Grain boundary motion in polycrystalline materials / Reza Darvishi Kamachali ; Gutachter: Ingo Steinbach, Dierk Raabe ; Fakultät für Maschinenbau." Bochum : Ruhr-Universität Bochum, 2013. http://d-nb.info/1205971882/34.

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37

LEITE, RICARDO TEIXEIRA. "A NOVEL AND STRAIGHTFORWARD METHODOLOGY TO ANALYZE MATERIALS UNDER CONSTANT-STRUCTURE OSCILLATORY MOTION (SAOS AND QL-LAOS)." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2017. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=32485@1.

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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
Nessa pesquisa, desenvolvemos uma nova metodologia para analizar materiais nos regimes oscilatórios linear e quasilinear. Foi mostrado que poucos experimentos reológicos são necessários. Além disso, a análise de dados apresentada é objetiva já apenas processamentos simples são necessários para avaliar as funções materiais. Esse fato contrasta com grande parte das análises de escoamento oscilatório de alta amplitude, tendo em vista que essas metodologias requerem manipulação matemática complexa dos dados. Por fim, a metodologia desenvolvida também apresenta grande evolução com relação às metodologias utilizadas anteriormente para analisar materiais no regime QL-LAOS.
In this research, we developed a novel methodology to analyze materials in the linear and quasilinear oscillatory regimes (constant structure motions). It was shown that very few rheometric experiments are necessary. Furthermore, data analysis presented on this thesis is straightforward as raw data obtained from the rheometer requires simple data processing before being input into the equations that evaluate the material functions. This fact is in contrast with most large amplitude oscillatory shear analysis methods since they aim to analyze structure-changing motions and this requires complex mathematical manipulation of data. At last, both experimental methodology and data analysis presented in this research are much simpler than the previous methodologies used to analyze materials in the QL-LAOS regime.

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38

Jia, Yabo. "Numerical simulation of steady states associated with thermomechanical processes." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEE007.

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De nombreux procédés de fabrication thermomécanique comme le laminage, le soudage ou encore l’usinage mettent en jeu soit des sollicitations mobiles par rapport à la matière fixe, soit de la matière mobile par rapport à des sollicitations fixes. Dans tous les cas, après un régime transitoire en général assez court, les champs thermiques, métallurgiques et mécaniques associés à ces procédés atteignent un état stationnaire. La recherche de ces états stationnaires à l’aide de la méthode des éléments finis classique nécessite de mettre en œuvre des modèles complexes et couteux où les sollicitations se déplacent par rapport à la matière (ou l’inverse). La recherche directe des états stationnaires a fait l’objet de nombreux travaux de recherche ces trente dernières années. Des méthodes sont aujourd’hui disponibles et pour certaines sont proposées dans des codes de calcul du commerce. Ainsi, une option de calcul dite repère mobile proposée par différents auteurs est disponible dans le logiciel SYSWELD. Cette méthode permet de calculer les états thermique, métallurgique et mécanique stationnaires associés à un procédé de soudage, en résolvant un problème de diffusion-convection en thermique et en intégrant, en mécanique, les équations constitutives du comportement du matériau le long des lignes de courant. Si cette méthode a été utilisée avec succès dans de nombreuses applications, elle présente néanmoins quelques limitations. Ainsi le maillage doit être structuré et la convergence des calculs est en général assez lente. Nous proposons dans cette thèse de résoudre le problème mécanique dans un repère lié aux sollicitations, en nous appuyant sur une méthode de calcul par éléments finis reposant sur l’intégration nodale et la technique SCNI (Stabilized Conforming Numerical Integration). Cette méthode permet l’utilisation de maillages en tétraèdres (ou triangles en 2D) sans rencontrer de problème de verrouillage volumique résultant de l’incompressibilité plastique associée au critère de plasticité de von Mises. Plutôt que de rechercher directement l’état stationnaire, l’idée générale est ici de construire l’état stationnaire à partir d’une analyse transitoire en faisant entrer pas à pas la matière par l’amont et en la faisant sortir par l’aval d’un maillage fixe par rapport aux sollicitations et de taille limitée. L’état stationnaire n’est donc atteint qu’au bout d’un certain temps d’analyse. Après une introduction générale (Chapitre 1) et un état de l’art sur les méthodes existantes (Chapitre 2), nous présentons une approche de simulation du mouvement de matière dans le cadre de la méthode des éléments finis classique sur un problème de soudage (Chapitre 3). Nous y proposons également des conditions aux limites thermiques pertinentes pour calculer directement la distribution de températures en régime stationnaire. La méthode des éléments finis reposant sur l’intégration nodale est ensuite décrite au Chapitre 4. Les avantages et inconvénients de la méthode sont discutés. La méthode est validée sur une application en grandes déformations élastoplastiques, un problème de flexion et une simulation thermomécanique de soudage. La méthode des éléments finis reposant sur l’intégration nodale est alors développée pour prendre en compte un mouvement de matière (Chapitre 5). Trois types de mouvement sont considérés : en translation, circulaire et en hélice. Différentes méthodes de transport de champ sont abordées et discutées ainsi que le couplage thermomécanique. Des perspectives à ce travail sont proposées au Chapitre 6. Les perspectives envisagées visent d’une part à améliorer la méthode proposée et d’autre part, à développer la méthode pour simuler d’autres procédés. Une première application de la méthode à la simulation de la coupe orthogonale y est présentée
In the numerous thermomechanical manufacturing processes such as rolling, welding, or even machining involve either moving loads with respect to the fixed material or moving material with respect to fixed loads. In all cases, after a transient regime which is generally quite short, the thermal, metallurgical, and mechanical fields associated with these processes reach a steady state. The search for these stationary states using the classical finite element method requires the implementation of complex and expensive models where the loads move with respect to the material (or vice versa). The steady-state simulation in one increment has been the subject of much researches over the past thirty years. Methods are now available and some are integrated into calculation codes commercial. Thus, a so-called Moving Reference Frame method proposed by various authors is available in the SYSWELD software. This method makes it possible to calculate the steady-state of thermal, metallurgical, and mechanical states associated with a welding process, by solving a thermal diffusion-convection problem in thermal-metallurgy and by integrating, in mechanics, the constitutive equations of the material along the streamline. Moreover, this method has been used successfully in many applications, it nevertheless has some limitations. Thus the mesh must be structured and the convergence of computations is generally quite slow. In this thesis, we propose to solve the mechanical problem in a frame linked to the solicitations, by relying on a finite element calculation method based on nodal integration and the SCNI (Stabilized Conforming Numerical Integration) technique. This method allows the use of tetrahedron meshes (or 2D triangles) without encountering a locking problem resulting from the plastic incompressibility associated with the von Mises plasticity criterion. Rather than directly calculating the steady-state, the general idea here is to construct the steady-state from a transient analysis by bringing material step by step upstream and by making it exit downstream of a fixed mesh related to the solicitations and of the limited mesh size. The steady-state is therefore only achieved after certain steps of analysis. Apart from a general introduction (Chapter 1) and a state of the art on the existing methods (Chapter 2), we present an approach of simulation of the movement of material within the framework of the classical finite element method on a welding problem (Chapter 3). We also provide relevant thermal boundary conditions for directly calculating the steady-state of temperature distribution. The finite element method based on the nodal integration technique is then described in Chapter 4. The advantages and disadvantages of the method are discussed. The nodal-integration-based finite element is validated by comparing its simulation results with classical finite element methods in large elastoplastic strains, a bending problem, and a thermomechanical simulation of welding. The nodal-integration-based finite element is then developed and applied to simulate material motion (Chapter 5). Three types of movement are considered: translational, circular, and helical. Different methods of field transport are approached and discussed as well as thermomechanical coupling. Perspectives for this work are presented in Chapter 6. The envisaged perspectives aim, on the one hand, to improve the proposed method and on the other hand, to develop the method to simulate other processes. A first application of the material motion method to the simulation of the orthogonal cut is presented there

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James, Sheronica L. "Transcranial Ultrasound as a Potential Modality for Real-Time Observation of Brain Motion." Cleveland State University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=csu1491237629973431.

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Gooch, Adam. "Design, synthesis and self-assembly of hydrogen bonding motifs for materials applications." Thesis, University of Leeds, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.540561.

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Cicogna, Thiago Rodrigo. "Identificação de matrizes de função de resposta em freqüência multidirecionais em estruturas complexas." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/18/18135/tde-19012011-142931/.

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Este trabalho apresenta o desenvolvimento de uma metodologia para a estimativa de funções de resposta em freqüência angulares (FRFAs). Trata-se de uma técnica que utiliza transdutores piezelétricos (PZT) do tipo bimorph para a medição da curvatura local da estrutura através do potencial elétrico induzido pela extensão e compressão do sensor. A partir da estimativa da curvatura, a rotação pode ser obtida diretamente através de várias técnicas de interpolação (polinomial, formas modais, etc). Apresenta-se a modelagem téorica da qual se deriva as equações que governam a dinâmica de estruturas uni-dimensionais, do tipo viga, e estruturas bidimensionais, do tipo placa, ambas isotrópicas, onde se incorpora o sensor bimorph. Modelos em elementos finitos foram propostos no intuito de avaliar a utilização destes sensores (bimorphs) aplicados à estimativa das FRFAs. Apresentam-se também resultados numéricos e experimentais considerando-se uma viga engastada-livre (cantilever) e resultados numéricos considerando-se uma placa simplesmente apoiada. Um algoritmo genético foi ainda desenvolvido no intuito de determinar a posição e dimensão ótimas dos bimorphs em estruturas do tipo viga.
The present work aims to perform the development of an attractive approach for accurate measurement of angular frequency response functions (AFRFs). It uses bimorph piezoceramic patches to measure the structure\'s local curvature through the measurement of the electric potential induced by the extension and compression of the patch\'s top and bottom stripes, respectively. From this curvature, rotation can be obtained directly by several interpolation techniques (single polynomial, modes basis). Theoretical modeling of the vibration incorporating piezoelectric bimorph sensor is presented and equations governing the dynamics for one-dimensional structures, like a beam, and for two-dimensional structures, like a plate, are derived for isotropic structures. Finite element model for the dynamic analysis were proposed to evaluate bimorphs patches applied to the measurement of angular FRFs. Numerical and experimental results are presented considering a cantilever beam and numerical results for a simply supported plate as tested structured. Also, in this work, a genetic algorithm was used as an adaptive heuristic search algorithm for optimal placement and sizing of the bimorph sensor into beam like structures.

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Hussain, Hyder. "Torsion fatigue system for mechanical characterization of materials." Ohio : Ohio University, 2000. http://www.ohiolink.edu/etd/view.cgi?ohiou1172002877.

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Amirova, Svetlana R. "The influence of a simple shear deformation on a long wave motion in a pre-stressed incompressible elastic layer." Thesis, Keele University, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.491831.

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Kwok, Pui-wai. "The effects of gelomyrtol forte on human ciliary beat frequency and intracellular cyclic adenosine monophosphate in vitro /." View the Table of Contents & Abstract, 2007. http://sunzi.lib.hku.hk/hkuto/record/B38296913.

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Kwok, Pui-wai, and 郭佩瑋. "The effects of gelomyrtol forte on human ciliary beat frequency and intracellular cyclic adenosine monophosphate in vitro." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B4501291X.

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Potireddy, Santhi. "TRANSLATIONAL CONTROL OF MATERNAL mRNA POPULATION IN MOUSE EMBRYOS." Diss., Temple University Libraries, 2010. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/67111.

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Biochemistry
Ph.D.
Early mammalian development before the oocyte-to-embryo transition is under 'maternal control' from factors deposited in the cytoplasm during oocyte growth, synthesized independent of de novo transcription. Maternal mRNAs encode proteins necessary for early embryo development. Two elements in the mRNA 3’untranslated region (UTR), the cytoplasmic polyadenylation element (CPE) and the hexanucleotide (AAUAAA) are involved in the control of translation of specific mRNAs during meiotic maturation. Despite advances in understanding the translational regulation during meiotic maturation, regulation at the 1-cell stage has not been explained. More studies are required to explain this complex mechanism of temporal mRNA recruitment after fertilization. Maternal mRNAs translated at different stages were examined to understand how specific maternal mRNAs are synthesized and stored, what are these maternal mRNAs, which maternal mRNAs are translated, and how these maternal mRNAs are temporally regulated. Polysomal mRNAs from eggs and 1-cell embryos were analyzed by microarray analysis and this indicated that temporally significant biological activities were encoded by mRNAs recruited at different stages of development. The mRNAs recruited in eggs were involved in homeostasis and transport mechanisms and those recruited in zygotes were involved in biosynthesis and metabolic activities. These data indicated that there is a temporal regulation of maternal mRNAs to meet the different biological requirements of the embryos. After the identification of temporally translated mRNAs, experiments were performed to understand the mechanism underlying temporal translation. The prevalence of the CPE differed between the two mRNA populations translated i.e., egg and 1-cell stage polysomal mRNAs. CPEs were present in ~53% of transcripts at the 1-cell stage compared to ~86% at the MII stage. This indicated that novel motifs other than CPEs regulate translation of mRNAs at the 1-cell stage. Truncation and deletion experiments were conducted using chimeric mRNAs based on one mRNA that was enriched in the 1- cell polysomes (Bag4). These experiments led to the identification of two regulatory regions that control translation at the 1-cell stage, an 80 nt region and a 43 nt region with different regulatory motifs. The 80 nt region is involved in activation of translation and the 43 nt region has an inhibitory effect on translation at the MII and early 1-cell stage. These results provide a detailed picture of how specific maternal mRNAs are prevented from undergoing translation at the MII stage and how the effect of inhibition is eliminated by the late 1-cell stage.
Temple University--Theses

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Komoráš, Miroslav. "Pulsace toku kapaliny v pružné trubici." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2019. http://www.nusl.cz/ntk/nusl-401537.

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This master’s thesis is dealing with analysis of fluid flow pulse in a flexible tube representing e.g. an artery in a human body. In ANSYS program, 3D simulations were performed, and these are so-called interrelated FSI analysis. In Maple software, 1D simulations of fluid flow in the tube were performed for various thin-walled and thick-walled variants. The aim is using these programs to determine the flow rates and pressures in the tube, its wall deformation and stress. Therefore, the theoretical part deals mainly with basic equations of flow dynamics, linear and nonlinear models and rotationally symmetric vessels. In the computational part are described individual procedures in the mentioned programs.

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Kučerová, Tereza. "Čína v Africe - vývoj a motivy vzájemných vztahů." Master's thesis, Vysoká škola ekonomická v Praze, 2009. http://www.nusl.cz/ntk/nusl-11229.

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The China-African relations have a tradition of several centuries. However, in last two decades, the character of their relations changes and is getting the dimension of a phenomenon. Currently, China is in a very advantageous position - one leg in the developing world, the other in the developed one. Its economic growth reaches about ten percent a year and its economy has enlarged beyond the state's frontiers. China thus becomes dependent on the international trade in both export and import of sources. The African continent can offer both. This situation, however, is hardly compatible with the role of a superpower which China desires and which is attributed to it by many specialists. This thesis analyses three motives of mutual cooperation - commerce, raw materials and political and strategic interests. Its aim is to give a compact and comprehensive picture which will prove the trueness of the three motives. For better accession and understanding, case studies of selected countries are an integral part of the thesis.

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Ludwanowski, Simon [Verfasser], and Andreas [Akademischer Betreuer] Walther. "Bottom-up design of materials: from light-responsive molecular motifs to precise macroscopic properties." Freiburg : Universität, 2020. http://d-nb.info/1233966502/34.

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Hošek, Václav. "Distributed Ray Tracing." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2008. http://www.nusl.cz/ntk/nusl-235956.

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VYSOKÉ UČENÍ TECHNICKÉ V BRNĚ Distributed Ray Tracing, also called distribution ray tracing and stochastic ray tracing, is a refinement of ray tracing that allows for the rendering of "soft" phenomena, area light, depth of field and motion blur.

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Dissertations / Theses on the topic 'Material motion'

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