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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.
931

Submerged Transmission in Wave Energy Converters : Full Scale In-Situ Experimental Measurements

Strömstedt, Erland January 2012 (has links)
Different wave power technologies are in development around the world in different stages of prototype testing. So far only a few devices have been deployed offshore at full scale for extended periods of time. Little data is published about how these different devices perform. This thesis presents results from experiments with the full-scale offshore wave energy converters at the Lysekil research site on the Swedish west coast. The theories, experiments, measurements, performance evaluations and developments of the submerged transmission in the direct driven permanent magnet linear generator are in focus. The reciprocating submerged transmission fulfills the purpose of transmitting the absorbed mechanical wave energy through the capsule wall into the generator, while preventing the seawater from entering the capsule and reducing the life time of the converter. A measuring system with seven laser triangulation sensors has been developed to measure small relative displacements between piston rod and seal housing in the submerged transmission with excellent accuracy for the purpose of evaluating both functional behavior and successive wear in-situ. A method for calculating relative tilt angles, azimuth angles, differential tilt angles, and successive wear in the submerged transmission has been developed. Additional sensors systems have been installed in the converter enabling correlation and a thorough investigation into the operating conditions of the transmission and the converter. The thesis presents unique results from the measurements. A data acquisition system transmits the signals from the converter on the seabed to an onshore measuring station. Results are presented in time-, frequency- and the time-frequency domain. The results have given important information for further development of the submerged transmission, which is important to the survivability of the system. The thesis describes the status of research, and is a step that may influence future designs of wave energy devices for reaching survivability and a cost-effective renewable energy system. / <p>Published is a preprint version of the full text and should be combined by the errata.</p> / The Lysekil Wave Power Project
932

Overcoming problems with limiting DNA samples in forensics and clinical diagnostics using multiple displacement amplification

Muharam, Firman Alamsyah January 2006 (has links)
The availability of DNA samples that are of adequate quality and quantity is essential for any genetic analysis. The fields of forensic biology and clinical diagnostic pathology testing often suffer from limited samples that yield insufficient DNA material to allow extensive analysis. This study examined the utility of a recently introduced whole genome amplification method termed Multiple Displacement Amplification (MDA) for amplifying a variety of limited sample types that are commonly encountered in the fields of forensic biology and clinical diagnostics. The MDA reaction, which employs the highly processive bacteriophage φ29 DNA polymerase, was found to generate high molecular weight template DNA suitable for a variety of downstream applications from low copy number DNA samples down to the single genome level. MDA of single cells yielded sufficient DNA for up to 20,000,000 PCR assays, allowing further confirmatory testing on samples of limited quantities or the archiving of precious DNA material for future work. The amplification of degraded DNA material using MDA identified a requirement for samples of sufficient quality to allow successful synthesis of product DNA templates. Furthermore, the utility of MDA products in comparative genomic hybridisation (CGH) assays identified the presence of amplification bias. However, this bias was overcome by introducing a novel modification to the MDA protocol. Future directions for this work include investigations into the utility of MDA products in short tandem repeat (STR) assays for human identifications and application of the modified MDA protocol for testing of single cell samples for genetic abnormalities.
933

STATIC SHAPE CONTROL OF LAMINATED COMPOSITE PLATE SMART STRUCTURE USING PIEZOELECTRIC ACTUATORS �

Chee, Clinton Yat Kuan January 2000 (has links)
The application of static shape control was investigated in this thesis particularly for a composite plate configuration using piezoelectric actuators. A new electro-mechanically coupled mathematical model was developed for the analysis and is based on a third order displacement field coupled with a layerwise electric potential concept. This formulation, TODL, is then implemented into a finite element program. The mathematical model represents an improvement over existing formulations used to model intelligent structures using piezoelectric materials as actuators and sensors. The reason is TODL does not only account for the electro-mechanical coupling within the adaptive material, it also accounts for the full structural coupling in the entire structure due to the piezoelectric material being attached to the host structure. The other significant improvement of TODL is that it is applicable to structures which are relatively thick whereas existing models are based on thin beam / plate theories. Consequently, transverse shearing effects are automatically accounted for in TODL and unlike first order shear deformation theories, shear correction factors are not required. The second major section of this thesis uses the TODL formulation in static shape control. Shape control is defined here as the determination of shape control parameters, including actuation voltage and actuator orientation configuration, such that the structure that is activated using these parameters will conform as close as possible to the desired shape. Several shape control strategies and consequently algorithms were developed here. Initial investigations in shape control has revealed many interesting issues which have been used in later investigations to improve shape controllability and also led to the development of improved algorithms. For instance, the use of discrete actuator patches has led to greater shape controllability and the use of slopes and curvatures as additional control criteria have resulted in significant reduction in internal stresses. The significance of optimizing actuator orientation and its relation to piezoelectric anisotropy in improving shape controllability has also been presented. Thus the major facets of shape control has been brought together and the algorithms developed here represent a comprehensive strategy to perform static shape control.
934

Memory, music and displacement in the minor memoirs of Evelyn Crawford, Ruby Langford Ginibi and Lily Brett

Breyley, Gay Jennifer. January 2005 (has links)
Thesis (Ph.D.)--University of Wollongong, 2005. / Typescript. Includes bibliographical references: leaf 224-250.
935

Coming and going, the effects of displacement in novels by Atwood, Poulin, Robin, Urquhart

Moore, Monica Leigh-Anne January 1999 (has links) (PDF)
No description available.
936

Τεχνικογεωλογικές συνθήκες κατά τη διάνοιξη των σηράγγων Πλατάνου και Τράπεζας της Σ.Γ.Υ.Τ. Κιάτου – Αιγίου. Εφαρμογή αναλυτικών προσεγγίσεων για τον προσδιορισμό της αλληλεπίδρασης αντιστήριξης και περιβάλλουσας βραχομάζας / Geotechnical conditions during the excavation of two tunnels at Platanos and Trapeza of the Kiato - Egio railroad . Application of analytical programs (Plaxis) for determining the interaction between primary support and surrounding rock mass

Σωτήρχος, Αλέξανδρος 07 October 2011 (has links)
Σκοπός της παρούσας διατριβής είναι η παρουσίαση και μελέτη των τεχνικογεωλογικών συνθηκών κατά την διάνοιξη των σηράγγων Πλάτανου και Τράπεζας της Σ.Γ.Υ.Τ. Κιάτου – Αίγιου. Στην παρούσα εργασία θα γίνει η χρήση αναλυτικών μεθόδων και συγκεκριμένα της μεθόδου ανάλυσης πεπερασμένων στοιχείων του κώδικα Plaxis για τον προσδιορισμό της αλληλεπίδρασης μέτρων αντιστήριξης και περιβάλλουσας βραχομάζας. Αυτό θα γίνει μελετώντας τις μετρημένες κατά την διάνοιξη σύγκλισης και σύγκριση τους με τις υπολογισμένες από την μέθοδο των πεπερασμένων στοιχειών. / In this dissertation are presented and examined the geotechnical conditions during the excavation of two tunnels at Platanos and Trapeza of the Kiato - Egio railroad. Using analytical methods namely finite element method (FEM) and the code Plaxis for determining the interaction between primary support and surrounding rock mass. There examined the real displacement measured during the excavation in contrast with the calculated displacement by FEM. Also, there are correlated vertical displacements at the roof of the tunnel with overburden height.
937

Remediação de um argissolo contaminado por zinco e cobre com o uso da bentonita. / Remediation of a zinc and copper contaminated argisol with the use of bentonite.

TITO, Gilvanise Alves. 13 June 2018 (has links)
Submitted by Deyse Queiroz (deysequeirozz@hotmail.com) on 2018-06-13T13:49:19Z No. of bitstreams: 1 GILVANISE ALVES TITO - TESE PPGEA 2009..pdf: 11064945 bytes, checksum: bac5edce5a2a3875418ba29344312d3e (MD5) / Made available in DSpace on 2018-06-13T13:49:19Z (GMT). No. of bitstreams: 1 GILVANISE ALVES TITO - TESE PPGEA 2009..pdf: 11064945 bytes, checksum: bac5edce5a2a3875418ba29344312d3e (MD5) Previous issue date: 2009-09 / A contaminação dos solos por metais pesados tem sido um problema crescente ao meio ambiente e à saúde das pessoas em função da alta toxicidade, razão por que a ciência busca alternativas que possam impedir ou pelo menos minimizar os efeitos poluidores desses metais ou, ainda, remediar os ambientes já contaminados. Assim, vários estudos utilizando matérias adsorventes estão sendo conduzidos como forma de reduzir os efeitos poluidores desses metais. E importante conhecer o processo de adsorção de metais pesados por minerais de argila, uma vez que estes são capazes de imobilizar referidos metais. No presente trabalho avaliou-se, através de três experimentos, a capacidade da bentonita na remediação de solos contaminados com zinco e cobre. O primeiro experimento consistiu no estudo da adsorção desses metais pela bentonita, em pH 4; 5 e 6, utilizando-se os modelos matemáticos de Langmuir e Freundlich. A partir de experimentos tipo "batch" foram elaboradas isotermas de adsorção com quantidades crescentes de zinco e cobre (5; 10; 20; 30; 50; 100; 150 e 200 mg L"1); o segundo experimento consistiu no estudo da mobilidade de zinco e cobre em colunas de lixiviação, preparadas com solo e doses crescentes de bentonita (0; 30 e 60 t ha"1). Os parâmetros de transporte foram calculados através do modelo computacional DISP. No último experimento avaliou-se, em casa de vegetação, o efeito das doses de zinco e cobre (50; 250 e 450 mg kg"1) e de bentonita (0; 30 e 60 t ha"1), adicionados ao solo, na produção de fitomassa e composição mineral do feijoeiro. Terminado o experimento (65 dias), foram determinadas as concentrações do zinco e do cobre nas partes aéreas e nas raízes das plantas e no solo das unidades experimentais, cujos resultados permitiram concluir que a incorporação de bentonita ao solo aumentou a adsorção do zinco e do cobre e que esta adsorção é dependente do pH da solução; que os modelos de Langmuir e Freundlich se apresentaram adequados para descrever a adsorção desses metais; que o tamanho das partículas da bentonita não influenciou na adsorção e a incorporação de bentonita ao solo contribuiu para diminuir a concentração e o acúmulo dos metais zinco e cobre, nas plantas de feijão-macassar. / The contamination of soil by heavy metais has been a growing problem to the environment and to the people's health in function of their toxicity, that has induced the science to search alternatives to prevent, or at least, minimize the pollutant effects of those metais or still, remediate the already polluted environment. Thus, several studies using sorbent materiais are conducted aiming to reduce the pollution problems produced by the excess of heavy metais. It is important to know the process of adsorption of heavy metais by clay minerais, because these are capable to immobilize such metais. The present study was carried out aiming, through three experiments, to evaluate the ability of the bentonite clay on the remediation of soils contaminated with zinc and copper. The fírst experiment consisted in studying the adsorption of these metais by bentonite at pH 4; 5 and 6, using the mathematical models of Langmuir and Freundlich. Adsorption isotherms were elaborated from batch adsorption assays, with increasing zinc and copper concentrations (5; 10; 20; 30; 50; 100; 150 and 200 mg L"1); the second experiment consisted in studying the zinc and copper mobility through leaching columns, prepared with soil and increasing bentonite leveis (0; 30 and 601 ha"1). The transport parameters were calculated using the computer model DISP. Finally, a greenhouse experiment was conducted to evaluate the effects of zinc and copper (50; 250 and 450mg kg"1) and bentonite (0; 30 and 60 t ha"1) added to the soil, on the phytomass production and mineral composition of a bean plant (Vigna unguiculata.h). At the end of the experiment (65 days) the phytomass and the content of zinc and copper in the aerial part, in the roots and in the soil were determined. It was observed that the adsorption of the elements increased with the bentonite application being dependent of the pH of the solution; the two studied models are appropriate to describe the zinc and copper adsorption for the bentonite; the granulometric size of the bentonite does not influence the metais adsorption and that the application of bentonite to the soil contributed to the decrease the concentration and accumulation of the heavy metais in the bean plant.
938

Analyse de "Time Lapse" optiques stéréo et d'images radar satellitaires : application à la mesure du déplacement de glaciers / Analysis of optical stereo Time Lapse and radar satellite images : application to the measurement of glacier displacement

Pham, Ha Thai 24 February 2015 (has links)
L’observation de la Terre par des systèmes d’acquisition d’images permet de suivre l’évolution temporelle de phénomènes naturels tels que les séismes, les volcans ou les mouvements gravitaires. Différentes techniques existent dont l’imagerie satellitaire, la photogrammétrie terrestre et les mesures in-situ. Les séries temporelles d’images issues d’appareils photo automatiques (Time Lapse) sont une source d’informations en plein essor car elles offrent un compromis intéressant en termes de couverture spatiale et de fréquence d’observation pour mesurer les déplacements de surface de zones spécifiques. Cette thèse est consacrée à l’analyse de séries d’images issues de la photographie terrestre et de l’imagerie radar satellitaire pour la mesure du déplacement des glaciers Alpins. Nous nous intéressons en particulier aux problèmes du traitement de Time Lapse stéréo pour le suivi d’objets géophysiques dans des conditions terrain peu favorables à la photogrammétrie. Nous proposons une chaîne de traitement mono-caméra qui comprend les étapes de sélection automatique des images, de recalage et de calcul de champs de déplacement bidimensionnel (2D). L’information apportée par les couples stéréo est ensuite exploitée à l’aide du logiciel MICMAC pour reconstruire le relief et obtenir le déplacement tridimensionnel(3D). Plusieurs couples d’images radar à synthèse d’ouverture (SAR) ont également été traités à l’aide des outils EFIDIR pour obtenir des champs de déplacement 2D dans la géométrie radar sur des orbites ascendantes ou descendantes. La combinaison de mesures obtenues quasi-simultanément sur ces deux types d’orbites permet de reconstruire le déplacement 3D. Ces méthodes ont été mises en oeuvre sur des séries de couples stéréo acquis par deux appareils photo automatiques installés sur la rive droite du glacier d’Argentière et sur des images du satellite TerraSAR-X couvrant le massif du Mont-Blanc. Les résultats sont présentés sur des données acquises lors d’une expérimentation multi-instruments menée en collaboration avec l’IGN à l’automne 2013, incluant le déploiement d’un réseau de Géocubes qui ont fournit des mesures GPS. Elles sont utilisées pour évaluer la précision des résultats obtenus par télédétection proximale et spatiale sur ce type de glacier. / Earth observation by image acquisition systems allows the survey of temporal evolution of natural phenomena such as earthquakes, volcanoes or gravitational movements. Various techniques exist including satellite imagery, terrestrial photogrammetry and in-situ measurements. Image time series from automatic cameras (Time Lapse) are a growing source of information since they offer an interesting compromise in terms of spatial coverage and observation frequency in order to measure surface motion in specific areas. This PhD thesis is devoted to the analysis of image time series from terrestrial photography and satellite radar imagery to measure the displacement of Alpine glaciers. We are particularly interested in Time Lapse stereo processing problems for monitoring geophysical objects in unfavorable conditions for photogrammetry. We propose a single-camera processing chain that includes the steps of automatic photograph selection, coregistration and calculation of two-dimensional (2D) displacement field. The information provided by the stereo pairs is then processed using the MICMAC software to reconstruct the relief and get the three-dimensional (3D) displacement. Several pairs of synthetic aperture radar (SAR) images were also processed with the EFIDIR tools to obtain 2D displacement fields in the radar geometry in ascending or descending orbits. The combination of measurements obtained almost simultaneously on these two types of orbits allows the reconstruction of the 3D displacement. These methods have been implemented on time series of stereo pairs acquired by two automatic cameras installed on the right bank of the Argentière glacier and on TerraSAR-X satellite images covering the Mont-Blanc massif. The results are presented on data acquired during a multi-instrument experiment conducted in collaboration with the French Geographic National Institute (IGN) during the fall of 2013,with a network of Géocubes which provided GPS measurements. They are used to evaluate the accuracy of the results obtained by proximal and remote sensing on this type of glacier.
939

Migration de cellules cancéreuses dans des gels de collagène 3D / Cancer cells migration in 3D collagen gels

Laforgue, Laure 16 December 2016 (has links)
Au cours du développement du cancer, la migration des cellules cancéreuse en 3D joue un rôle essentiel dans le processus de dissémination des métastases. L’étude de la migration cellulaire dans des matrices 3D ainsi que les conséquences induites sur cette matrice sont actuellement étudiées par plusieurs équipes de recherche. Notamment, la réorganisation de la matrice extracellulaire et plus précisément les déplacements des fibres de la matrice induits par les forces que la cellule exerce sont des études en plein essor. Nous avons étudié comment les cellules cancéreuses migrent dans des gels 3D en utilisant du collagène et de la fibronectine pour mimer la matrice extracellulaire des tissus. Nous avons utilisé un microscope confocal afin de visualiser le cytosquelette d’actine des cellules en fluorescence et les fibres de collagène en réflexion. Dans ce travail,nous avons utilisé différentes concentrations de collagène et des lignées cellulaires d’invasivités différentes. A partir des films 3D obtenus en microscopie, nous avons déterminé la vitesse et la persistance des cellules cancéreuses en fonction de leur invasivité et de la concentration de collagène. La vitesse augmente avec l’invasivité cellulaire et diminue avec l’augmentation de la concentration en collagène. La persistance ne dépend que de la concentration en collagène et décroit avec celle-ci. Nous avons également calculé les champs de déplacement des fibres de collagène à l’aide d’un programme de corrélation de volume. Nous avons pu étudier ces champs de déplacement en fonction du type de migration de la cellule, de l’invasivité cellulaire et de la concentration en collagène des gels. Nous avons montré que les normes de vecteurs de déplacement augmentent avec l’invasivité cellulaire et diminuent avec l’augmentation de concentration en collagène. Enfin, ces champs de déplacement nous ont permis de déterminer les étapes des migrations mésenchymateuse et amiboïde en 3D. Nous avons découvert 5 étapes pour la migration mésenchymateuse correspondant au repos de la cellule, à la création d’une extension membranaire, à l’adhésion de la cellule aux fibres, au détachement de l’arrière du corps cellulaire afin de permettre à la cellule de migrer et à la dissolution de l’adhésion cellule/fibre. 4 étapes ont été déterminées pour la migration amiboïde et correspondent au repos de la cellule, à la création d’une extension membranaire, au déplacement de la cellule en poussant sur son environnement et à la rotation de la cellule. Ces étapes associées à des champs de déplacement sont en accord avec la littérature et nous avons pu mettre en évidence de nouvelles étapes comme la rotation de la cellule dans la migration amiboïde.Ces résultats permettent de mieux comprendre comment se déroule la migration des cellules cancéreuses dans une matrice extracellulaire. / 3D migration of cancer cells plays an essential role in the dissemination of cells during metastasisin cancer. The behavior of cancer cells migrating in a 3D extracellular matrix and its consequences on themicroenvironment are still currently under investigation. The study of the reorganization of the extracellular matrixfibers and more precisely how the fibers move due to the forces that the cell exerts just start to be investigating.We studied how cancer cells migrate in 3D gels using collagen and fibronectin to mimic the extracellularmatrix. We used confocal microscopy to image the actin cytoskeleton of cells in fluorescence and fibers in reflectionover time. In our studies, we used different collagen concentrations and cell lines with different invasivities. Fromthese 3D movies, we determined cancer cell velocities and persistence as a function of collagen gel concentration aswell as cell invasiveness. The cells velocities increase with invasiveness and decrease with collagen concentration.As for persistence, it decreases with collagen concentration but it do not change with cells invasiveness. We alsocalculated the displacement field of the collagen using a volume correlation program. Using this information, westudied the fibers displacement induced by the cell depending on its migration type, its invasivity and the collagenconcentration. We showed norms of fibers deplacement vectors increase with cell invasiveness and decrease withcollagen concentration. Finally, the displacement fields enabled us to determine the migration steps of mesenchymaland amiboid migrations. We discovered 5 steps in mesenchymal migration : cell rest, creation of extension, adhesionof the cell to the fibers, detachment of the cell rear and dissolution of cell/fibers adhesions. 4 steps have beencharacterized in amiboid migration : cell rest, creation of extension, displacement of the cell by pushing on fibersand rotation of the cell. These steps associated with displacement fields are in agreement with litterature and wehighlighted new steps as the rotation of the cell in amiboid migration.Taken together these results enable us to better understand how the migration of cancer cells takes place in a3D matrix.
940

[en] EVALUATION OF THE DYNAMIC BEHAVIOR OF A GRAVITY WALL / [pt] AVALIAÇÃO DO COMPORTAMENTO DINÂMICO DE UM MURO DE GRAVIDADE

TANIA VANESSA BUSTAMANTE UBILLUS 05 October 2010 (has links)
[pt] O projeto de estruturas de contenção de solos submetidas a carregamentos dinâmicos é um importante tema da engenharia geotécnica, principalmente nos países andinos. A abordagem mais comum consiste no emprego de métodos de equilíbrio limite (pseudo-estáticos) ou de técnicas baseadas na formulação de Newmark (1965) para cálculo de deslocamentos permanentes da estrutura. Um método pseudo-estático clássico é o apresentado por Mononobe-Okabe (1929) como uma extensão da teoria de Coulomb (1773), enquanto que Richards e Elms (1979) sugeriram um método de projeto baseado em deslocamentos permanentes. Nesta dissertação os resultados da aplicação do método dos elementos finitos na análise dinâmica do comportamento de um muro de gravidade são comparados com aqueles previstos por diversos outros métodos analíticos propostos na literatura, tanto em termos do cálculo de empuxos quanto de deslocamentos permanentes. As vantagens e limitações destes métodos são discutidas, bem como são discutidos vários aspectos da modelagem numérica que devem ser cuidadosamente considerados pelo engenheiro geotécnico para obter uma simulação representativa do problema dinâmico. / [en] The design of earth retaining structures during earthquakes is an important subject of the geotechnical engineering, mainly in the Andesian countries of South America. The most common approach consists in the use of some quasi-static method or technique based on Newmark s (1965) model to estimate inelastic displacements of the structure. The classical quasi-static method is the one proposed by Mononobe -Okabe (1926, 1929), as an extension of the Coulomb s (1773) theory to a dynamic context, while Richards and Elms (1979) suggested a design method based on inelastic displacements. In this thesis the dynamic response of a gravity retaining wall obtained through the finite element method are compared with those predicted by several other analytical formulation proposed in the literature, concerning both the resultant of the earth pressures and the wall displacements experienced during the earthquake. The advantages and shortcomings in the application of all these methods are discussed herein, as well as several modeling aspects are discussed that must be carefully considered by the geotechnical engineer in order to obtain a representative simulation of the dynamical problem.

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