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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.
291

Characterizing the Low Net-to-Gross, Fluviodeltaic Dry Hollow Member of the Frontier Formation, Western Green River Basin, Wyoming

Meek, Scott Romney 01 August 2017 (has links)
The Frontier Formation in the Green River Basin of southwestern Wyoming consists of Late Cretaceous (Cenomanian-Turonian) marine and non-marine sandstones, siltstones, mudstones and coals deposited on the western margin of the Cretaceous Interior Seaway. Tight gas reservoirs exist in subsurface fluviodeltaic sandstones in the upper Frontier Formation (Dry Hollow Member) on the north-south trending Moxa Arch within the basin. These strata crop out in hogback ridges of the Utah-Idaho-Wyoming Thrust Belt approximately 40 km west of the crest of the Moxa Arch. Detailed, quantitative outcrop descriptions were constructed using emerging photogrammetric techniques along with field observations and measured sections at five key outcrop localities along the thrust belt. Understanding the architectural style of this low net-to-gross fluvial system allows for improved reservoir prediction in this and other comparable basins. The architectural style of the Dry Hollow Member fluvial deposits varies vertically as the result of a relative shoreline transgression during Dry Hollow deposition. Amalgamated conglomerates and associated fine to coarse sandstones near the base of the section and much thinner, isolated sandstones near the top of the Dry Hollow occur in laterally extensive units that can be identified over tens of kilometers. These units also provide means to relate outcrop and subsurface stratigraphic architecture. Combined with available subsurface data, fully-realized 3D static reservoir models for use as analogs in subsurface reservoir characterization may be constructed. Grain size, reservoir thickness and connectivity of fluvial sandstones is generally greatest near the base of this member and decreases upward overall. Despite relative isolation of some channel bodies, geocellular facies modeling indicates good lateral and vertical connectivity of most channel sandstones. The Kemmerer Coal Zone, with little sandstone, divides lower and upper well-connected sandy units.
292

Zjištění výskytu vadného držení těla a svalové nerovnováhy u dívek ve věku 15-19 let a možnosti ovlivnění prvky zdravotní tělesné výchovy / Determination of the occurrence of poor posture and muscle imbalance of female students aged 15-19 and possibilities of influencing that by elements of health physical education

Grundová, Michaela January 2019 (has links)
Title: Determination of the occurrence of poor posture and muscle imbalance of female students agend 15-19 and possibilities of influencing that by elements of health physical education. Objectives: The aim of this study is determination of change in posture and muscle imbalance due to regural health exercise for the period of 3 months Methods: Klein, Thomas and Mayer test method was used to determine posture of each proband. Functional tests of muscles with tendency to shorten were performed according to Bursová (2005), Hošková and Matoušová (2000), Pernicová et al. (1993). Functional tests of muscles with a tendency to become flabby were tested according to Hošková and Matoušová (2000). The method of theoretical analysis and synthesis was used for the chapter "Piece of knowledge" (Štumbauer, 1990). The chapter "Knowledge of data" was processed by Microsoft Office Excel. One-piece non-parametric Wilcoxon test was used to verify the results. Results: In the chapter "Results" we find detailed information about probands, which we have gained from the questionnaire and from a personal interview. Each proband is discussed and evaluated by means of testing posture and muscle imbalance. Keywords: posture, muscle imbalance, muscle balance, testing, tight muscles, flabby muscles, health physical education,...
293

Clinical Significance of the Straight-Leg-Raising Test

吉田, 徹, 井戸田, 仁, YOSHIDA, TOHRU, IDOTA, HITOSHI 11 1900 (has links)
名古屋大学博士学位論文 学位の種類 : 博士(医学)(論文) 学位授与年月日:平成4年3月25日 井戸田仁氏の博士論文として提出された
294

L’entérotoxine STb d’Escherichia coli affecte les jonctions serrées des cellules intestinales épithéliales

Ngendahayo Mukiza, Clément 08 1900 (has links)
La toxine thermostable d’E.coli (STb) est une cause de diarrhée chez l’homme et l’animal. STb se lie au sulfatide, son récepteur, puis s’internalise. Dans le cytoplasme, par une cascade d’événements, STb déclenche l’ouverture des canaux ioniques permettant la sécrétion des ions et la perte d’eau menant à la diarrhée. Les jonctions serrées forment une barrière physique intercellulaire dans les cellules épithéliales intestinales, contrôlant ainsi le flux paracellulaire des ions et de l’eau. Les jonctions serrées sont affectées par divers pathogènes et par leurs toxines. À ce jour, l’effet de STb sur les jonctions serrées n’a pas été étudié. L’étude entreprise visait à explorer l’effet de STb sur les jonctions serrées et la barrière épithéliale des cellules intestinales. Des cellules épithéliales intestinales du colon humain (T84) ont été traitées pendant 24h soit avec la toxine STb purifiée soit avec une souche d’E.coli exprimant STb. La résistance transépithéliale (TER), le flux de marqueurs paracellulaires et la microscopie confocale ont été utilisés pour analyser les effets de STb sur les jonctions serrées. Les monocouches traitées par la souche E.coli exprimant STb et la toxine STb purifiée ont manifesté une forte réduction de TER (p<0.0001) parallèlement à une augmentation significative de la perméabilité paracellulaire à l’Albumine de Sérum Bovin marqué avec l’IsoThioCyanate Fluoroscéine, BSA-FITC (p<0.0001) comparativement aux cellules non traitées et aux cellules traitées par une souche d’E.coli commensale non-toxinogène. L’augmentation de la perméabilité paracellulaire induite par STb a été associée à une dissolution générale et une condensation des fibres de stress centrales des filaments d’actine. Le réarrangement des filaments d’actine a été accompagné par une redistribution et une fragmentation des protéines des jonctions serrées dont l’occludine, la claudine-1 et la Zonula Occludens-1. Les mêmes modifications on été observées après l’intoxication des cellules T84 avec un octapeptide synthétique retrouvé dans la séquence de STb correspondant à une séquence consensus de la toxine ZOT de Vibrio cholerae, impliquée dans la réorganisation des jonctions serrées. Cet effet n’a pas été observé lorsque les cellules ont été traitées avec un octapeptide synthétique comportant les mêmes acides aminés mais distribués de façon aléatoire ou avec la toxine mutée (D30V). Nos résultats montrent pour la première fois que STb induit le dysfonctionnement de la barrière épithéliale intestinale en modifiant la distribution des protéines des jonctions serrées. Ces résultats ouvrent une nouvelle voie pour la compréhension de la pathogenèse de diarrhée causée par la toxine STb. / Escherichia coli heat-stable toxin (STb) causes diarrhea in Man and animals. STb binds to sulfatide, its receptor, followed by its internalization. Inside the cytoplasm, through a cascade of events, STb triggers the opening of ion channels allowing ion secretion and water loss leading to diarrhea. Tight junctions (TJs) are well known for controlling paracellular traffic of ions and water by forming a physical intercellular barrier in epithelial cells. Some bacterial toxinz are known to affect adversibly TJs. To date, the impact of STb on TJs has not been investigated. The present study aimed to explore the effect of STb on TJs and the barrier function in intestinal epithelial cells. Human colon intestinal epithelial cells (T84) were treated for 24h with either purified STb toxin or an E. coli strains expressing STb. TransEpithelial Resistance (TER), paracellular flux marker and confocal microscopy were used to analyze the effect of STb toxin on TJs. An E. coli strains expressing STb as well as purified STb caused a significant reduction of TER (p<0.0001) parallely to an increase in paracellular permeability to BSA-FITC (p<0.0001) compared to untreated cells or a commensal non toxinogenic E.coli strain. The increased paracellular permeability induced by STb was associated with a marked general dissolution and condensation of central F-actin stress fibers. F-actin disorganisation was accompanied by redistribution and fragmentation of occludin, claudin-1 and ZO-1 (Zonula Occludens-1) proteins. These changes were also observed following intoxication of T84 cells with an 8 amino acids peptide found in the STb sequence corresponding to a consensus sequence of Vibrio cholerae Zot toxin, shown to be involved in TJs disassembly. This effect was not observed with the scramble peptide and D30V mutant. Our findings suggest that STb induces epithelial barrier dysfunction by changes in tight junction proteins that could contribute to the observed diarrhea. These results provide new insight into the diarrhea pathogenesis caused by STb.
295

Étude en dynamique moléculaire par approximation des liaisons fortes de l'influence des défauts ponctuels dans la relaxation du silicium amorphe

Urli, Xavier January 2007 (has links)
Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal
296

The Electronic Band Structure Of Iii (in, Al, Ga)-v (n, As, Sb) Compounds And Ternary Alloys

Mohammad, Rezek Mahmoud Salim 01 July 2005 (has links) (PDF)
In this work, the electronic band structure of III (In, Al, Ga) - V (N, As, Sb) compounds and their ternary alloys have been investigated by density functional theory (DFT) within generalized gradient approximation (GGA) and empirical tight binding (ETB) calculations, respectively. The present DFT-GGA calculations have shown direct band gap structures in zinc-blende phase for InN, InAs, InSb, GaN, and GaAs. However, indirect band gap structures have been obtained for cubic AlN, AlSb and AlAs com- pounds / here, the conduction band minima of both AlN and AlAs are located at X symmetry point, while that of AlSb is at a position lying along Gamma- X direction. An important part of this work consists of ETB calculations which have been parameterized for sp3d2 basis and nearest neighbor interactions to study the band gap bowing of III(In / Al)- V(N / As / Sb) ternary alloys. This ETB model provides a satisfactory electronic properties of alloys within reasonable calculation time compared to the calculations of DFT. Since the present ETB energy parameters reproduce successfully the band structures of the compounds at &iexcl / and X symme- try points, they are considered reliable for the band gap bowing calculations of the ternary alloys. In the present work, the band gap engineering of InNxAs1&iexcl / x, InNxSb1&iexcl / x, InAsxSb1&iexcl / x, Al1&iexcl / xInxN, Al1&iexcl / xInxSb and Al1&iexcl / xInxAs alloys has been studied for total range of constituents (0 &lt / x &lt / 1). The downward band gap bowing seems the largest in InNxAs1&iexcl / x alloys among the alloys considered in this work. A metallic character of InNxAs1&iexcl / x, InNxSb1&iexcl / x and InAsxSb1&iexcl / x has been ob- tained in the present calculations for certain concentration range of constituents (N / As) as predicted in the literature. Even for a small amount of contents (x), a decrease of the electronic e&reg / ective mass around &iexcl / symmetry point appears for InNxAs1-x, InNxSb1-x and InAsxSb1-x alloys manifesting itself by an increase of the band curvature. The calculated cross over from indirect to direct band gap of ternary Al alloys has been found to be consistent with the measurements. As a last summary, the determinations of the band gaps of alloys as a function of contents, the concentration range of con- stituents leading to metallic character of the alloys, the change of the electronic effective mass around the Brillioun zone center (Gamma) as a function of alloy contents, the cross over from indirect to direct band gap of the alloys which are direct on one end, indirect on the other end, are main achievements in this work, indispensable for the development of mate- rials leading to new modern circuit components.
297

A spin- and angle-resolved photoemission study of coupled spin-orbital textures driven by global and local inversion symmetry breaking

Bawden, Lewis January 2017 (has links)
The effect of spin-orbit coupling had once been thought to be a minor perturbation to the low energy band structure that could be ignored. Instead, a surge in recent theoretical and experimental efforts have shown spin-orbit interactions to have significant consequences. The main objective of this thesis is to investigate the role of the orbital sector and crystal symmetries in governing the spin texture in materials that have strong spin- orbit interactions. This can be accessed through a combination of spin- and angle-resolved photoemission spectroscopy (ARPES and spin-ARPES), both of which are powerful techniques for probing the one-electron band structure plus interactions, and supported by density functional theory calculations (DFT). We focus first on a globally inversion asymmetric material, the layered semiconductor BiTeI, which hosts a giant spin-splitting of its bulk bands. We show that these spin-split bands develop a previously undiscovered, momentum-space ordering of the atomic orbitals. We demonstrate this orbital texture to be atomic element specific by exploiting resonant enhancements in ARPES. These orbital textures drive a hierarchy of spin textures that are then tied to the constituent atomic layers. This opens routes to controlling the spin-splitting through manipulation of the atomic orbitals. This is contrasted against a material where inversion symmetry is globally upheld but locally broken within each monolayer of a two layer unit cell. Through our ARPES and spin-ARPES measurements of 2H-NbSe2, we discover the first experimental evidence for a strong out-of-plane spin polarisation that persists up to the Fermi surface in this globally inversion sym- metric material. This is found to be intrinsically linked to the orbital character and dimensionality of the underlying bands. So far, previous theories underpinning this (and related) materials' collective phases assume a spin- degenerate Fermi sea. We therefore expect this spin-polarisation to play a role in determining the underlying mechanism for the charge density wave phase and superconductivity. Through these studies, this thesis then develops the importance of global versus local inversion symmetry breaking and uncovers how this is intricately tied to the underlying atomic orbital configuration.
298

Towards quantum optics experiments with single flying electrons in a solid state system / L'expériences d'optique quantique avec un unique électron volant dans la matière condensée

Bautze, Tobias 19 December 2014 (has links)
Ce travail de thèse porte sur l’étude fondamentale de systèmes nano-électroniques,mesurés à très basse température. Nous avons réalisé des interféromètres électroniques àdeux chemins à partir d’électrons balistiques obtenus dans un gaz 2D d’électrons d’unehétéro-structure GaAs/AlGaAs. Nous montrons que la phase des électrons, et ainsileur état quantique,peut être contrôlée par des grilles électrostatiques. Ces dispositifsse révèlent être des candidats prometteurs pour la réalisation d’un qubit volant. Nousavons développé une simulation numérique évoluée d’un modèle de liaisons fortes à partirde transport quantique ballistique qui décrit toutes les découvertes expérimentales etnous apporte une connaissance approfondie sur les signatures expérimentales de cesdispositifs particuliers. Nous proposons des mesures complémentaires de ce système dequbit volants. Pour atteindre le but ultime, à savoir un qubit volant à un électron unique,nous avons assemblé la source à électron unique précédemment développée dans notreéquipe à un beam splitter électronique. Les électrons sont alors injectés depuis une boîtequantique à un train de boîte quantiques en mouvement. Ce potentiel électrostatique enmouvement est généré par des ondes acoustiques de surface créées par des transducteursinter-digités sur le substrat GaAs piézo-électrique. Nous avons étudié et optimisé chacunde ces composants fondamentaux nécessaires à la réalisation d’un beam splitter à électronunique et développé un procédé local et fiable de fabrication. Ce dispositif nous permet d’étudier les interactions électroniques pour des électrons isolés et pourra servir de basede mesure pour des expériences d’optique quantiques sur un système électronique del’état condensé. Enfin, nous avons développé un outil puissant de simulation du potentielélectrostatique à partir de la géométrie des grilles. Ceci permet d’optimiser la conceptiondes échantillons avant même leur réalisation. Nous proposons ainsi un prototype optimiséde beam splitter à électron unique. / This thesis contains the fundamental study of nano-electronic systems at cryogenictemperatures. We made use of ballistic electrons in a two-dimensional electron gasin a GaAs/AlGaAs heterostructure to form a real two-path electronic interferometerand showed how the phase of the electrons and hence their quantum state can becontrolled by means of electrostatic gates. The device represents a promising candidateof a flying qubit. We developed a sophisticated numerical tight-binding model based onballistic quantum transport, which reproduces all experimental findings and allows togain profound knowledge about the subtle experimental features of this particular device.We proposed further measurements with this flying qubit system. With the ultimate goalof building a single electron flying qubit, we combined the single electron source that hasbeen developed in our lab prior to this manuscript with an electronic beam splitter. Theelectrons are injected from static quantum dots into a train of moving quantum dots.This moving potential landscape is induced in the piezoelectric substrate of GaAs bysurface acoustic waves from interdigial transducers. We studied and optimized all keycomponents, which are necessary to build a single electron beam splitter and built up areliable local fabrication process. The device is capable of studying electron interactionson the single electron level and can serve as a measurement platform for quantum opticsexperiments in electronic solid state systems. Finally, we developed a powerful toolcapable of calculating the potential landscapes of any surface gate geometry, which canbe used as a fast feedback optimization tool for device design and proposed an optimizedprototype for the single electron beam splitter.
299

Estat?stica n?o-extensiva aplicada ao c?lculo do calor espec?fico eletr?nico em estruturas quasiperi?dicas

Ferreira, Alzey Gomes 02 October 2008 (has links)
Made available in DSpace on 2014-12-17T15:14:49Z (GMT). No. of bitstreams: 1 AlzeyGF.pdf: 1374839 bytes, checksum: 04a6f9d10ed4cb9e18af438a89ba7f26 (MD5) Previous issue date: 2008-10-02 / Systems whose spectra are fractals or multifractals have received a lot of attention in recent years. The complete understanding of the behavior of many physical properties of these systems is still far from being complete because of the complexity of such systems. Thus, new applications and new methods of study of their spectra have been proposed and consequently a light has been thrown on their properties, enabling a better understanding of these systems. We present in this work initially the basic and necessary theoretical framework regarding the calculation of energy spectrum of elementary excitations in some systems, especially in quasiperiodic ones. Later we show, by using the Schr?odinger equation in tight-binding approximation, the results for the speci&#64257;c heat of electrons within the statistical mechanics of Boltzmann-Gibbs for one-dimensional quasiperiodic systems, growth by following the Fibonacci and Double Period rules. Structures of this type have already been exploited enough, however the use of non-extensive statistical mechanics proposed by Constantino Tsallis is well suited to systems that have a fractal pro&#64257;le, and therefore our main objective was to apply it to the calculation of thermodynamical quantities, by extending a little more the understanding of the properties of these systems. Accordingly, we calculate, analytical and numerically, the generalized speci&#64257;c heat of electrons in one-dimensional quasiperiodic systems (quasicrystals) generated by the Fibonacci and Double Period sequences. The electronic spectra were obtained by solving the Schr?odinger equation in the tight-binding approach. Numerical results are presented for the two types of systems with di&#64256;erent values of the parameter of nonextensivity q / Sistemas cujos espectros s?o fractais ou multifractais t?m sido bastante estudados nos ?ltimos anos. O entendimento completo do comportamento de muitas propriedades f?sicas destes sistemas ainda est? longe de ser completamente efetivado devido ? complexidade dos pr?prios sistemas. Desta maneira, novas aplica??es e novos m?todos de estudo dos seus espectros t?m sido feitos, possibilitando uma melhor compreens?o acerca desses sistemas. Apresentamos neste trabalho de disserta??o inicialmente todo o arcabou?o te?rico b?sico e necess?rio no tocante ? obten??o dos espectros de energia de excita??es elementares em alguns sistemas, mais especi&#64257;camente nos sistemas quasiperi?dicos. Posteriormente mostramos, usando a equa??o de Schrodinger na aproxima??o de liga??o forte, os resultados para o calor espec?&#64257;co de el?trons com a mec?nica estat?stica de Boltzmann-Gibbs para sistemas quasiperi?dicos unidimensionais tipo Fibonacci e Per?odo Duplo. Estruturas desse tipo j? foram bastante exploradas, no entanto o uso da mec?nica estat?stica n?o-extensiva proposta por Constantino Tsallis ? bem adequado para sistemas que apresentam de alguma forma um per&#64257;l fractal, e portanto nosso principal objetivo foi aplic?-la para o c?lculo de grandezas termodin?micas ampliando um pouco mais a compreens?o das propriedades desses sistemas. Neste sentido, calculamos anal?tica e numericamente o calor espec?&#64257;co generalizado de el?etrons em sistemas quasiperi?dicos unidimensionais (quasicristais) gerados pelas sequ?ncias de Fibonacci e Per?odo Duplo. Os espectros eletr?nicos foram obtidos fazendo-se uso tamb?m da equa??o de Schrodinger na aproxima??o de liga??o forte. Resultados num?ricos s?o apresentados para os dois tipos de sistemas com diferentes valores do par?metro de n?o-extensividade q
300

Transport électronique dans les nanotubes de carbone individuels sous conditions extrêmes / Electronic transport in individual carbon nanotubes under extreme conditions

Caillier, Christophe 11 December 2009 (has links)
Cette thèse a pour objet l'étude des propriétés de transport électronique des nanotubes de carbone soumis à des pressions hydrostatiques de l'ordre du gigapascal. L'originalité de ce travail réside dans le fait d'étudier ces propriétés sur des nanotubes individuels. Ceci permet de simplifier la géométrie du système et de faire apparaître des comportements propres à chaque type de nanotubes. Le cas d'un nanotube multifeuillets composé d'un tube externe à faible bande interdite et d'un tube interne métallique a permis d'observer i) l'évolution sous pression de la barrière de Schottky aux contacts or-nanotube, ii) l'évolution de la résistance inter-feuillet, mettant en évidence une transition associée au changement de section du nanotube, iii) la diminution de l'hystérésis en tension de grille. D'autre part, une étude systématique sur des nanotubes métalliques permet de faire ressortir un comportement général pour le contact or-nanotube sous pression, indépendant de la chiralité du nanotube et du milieu transmetteur de pression. Nombre de ces effets peuvent être utilisés pour des applications électroniques ou électro-mécaniques, tels que des capteurs de pression miniatures et environ dix fois plus sensibles que certains standards actuels. Un modèle simple de calculs par la méthode des liaisons fortes est aussi mis en œuvre afin de prédire l'évolution des propriétés électroniques des nanotubes de carbone sous pression en fonction de leur chiralité. Ce modèle permet de prédire d'autres phénomènes qui pourraient être observés grâce à une étude approfondie et systématique utilisant la méthode expérimentale développée au cours de cette thèse / This thesis focuses on the electronic transport properties of carbon nanotubes under hydrostatic pressures as high as one gigapascal. The originality of this work is the study of these properties on individual nanotubes. This simplifies the geometry of the system and allows studying the behaviour of each type of nanotubes. The case of a multiwalled nanotube made of at least an external semiconducting tube and an internal metallic one led us to observe i) a pressure induced change of the Schottky barrier at the gold-nanotube contacts, ii) a evolution of the intershell resistance, featuring a transition associated to the change of the nanotube cross section, iii) the decrease of the gate voltage hysteresis. Additionally, a systematic study on metallic nanotubes allowed pointing out a general behaviour of the gold-nanotube contact under pressure, which is independent on the nanotube chirality and on the pressure transmitting medium. Many of these effects can be useful to design electronic or electro-mechanical devices, such as miniature pressure sensors that would be about ten times more sensitive than some of today's standards. A simple tight-binding model is also applied to predict the evolution of the carbon nanotube electronic properties under pressure with respect to their chirality. This model allows predicting other phenomena, which could be observed in the context of a deeper and systematic study using the experimental method that was developed in this thesis.

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