• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 19
  • 10
  • 3
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 41
  • 7
  • 5
  • 5
  • 5
  • 5
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 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.
21

Caractérisation et valorisation de protections solaires pour la conception de bâtiments : analyse expérimentale et propositions de modélisations

Dugué, Antoine 18 October 2013 (has links) (PDF)
Lors d'une démarche de modélisation énergétique d'un bâtiment, la prise en compte de l'enveloppe solaire reste souvent imprécise. L'objet du travail présenté ici est la description détaillée de solutions de protections solaires, induisant un tirage thermique (bardage, store), dans un objectif de modélisation et de valorisation pour répondre aux besoins d'industriels du secteur ; la caractérisation des performances permet alors d'assister la maitrise d'œuvre en phase conception.La mise en place d'une plateforme expérimentale - mur exposé sud muni d'une protection solaire devant lame d'air - a permis la mesure de températures d'airs et d'éléments solides présents dans le système, de vitesses d'écoulement dans la lame d'air ouverte, et du flux radiatif incident. Deux types de bardage bois, un type de store et un type de métal déployé ont été considérés.Parallèlement, un modèle 1D amélioré de transfert de chaleur dans le système étudié est développé. Trois familles de modèle de convection dans la lame d'air sont identifiées, présentées et intégrées dans le modèle global. La description de l'écoulement dans la lame d'air est retenue à partir d'analyses des résultats expérimentaux.Un modèle simplifié d'intégration de tels systèmes de protections solaires dans des plateformes de simulation thermique de bâtiments est proposé, basé sur la paramétrisation des sollicitations extérieures par le facteur solaire. La méthode de calcul du facteur solaire est présentée. Le caractère intrinsèque facteur solaire et son intérêt sont discutés notamment à partir d'analyse de sensibilités.
22

Etude des caractéristiques d'un faisceau contrôlé en polarisation après transmission à travers différentes nanostructures / Study of the characteristics of a polarization-controlled beam after transmission through different nanostructures

Lombard, Emmanuel 24 February 2012 (has links)
Dans ce travail, nous avons étudié l’interaction entre une lumière contrôlée en polarisation et deux structures sub-longueurs d’onde gravées dans un film métallique opaque, en utilisant la méthode de la « matrice de Mueller ». Tout d’abord, nous avons montré qu’un réseau concentrique de fentes sub-longueurs d’onde percées à travers le film permet de filtrer et de convertir une polarisation incidente, ce qui génère une polarisation radiale. Nous avons aussi montré sa capacité à générer des faisceaux de Bessel non-diffractifs J0 ou J2 à travers de telles structures, et à contrôler leur hélicité en changeant la polarisation circulaire en préparation ou en analyse. Ensuite, nous avons montré la création d’une cible plasmonique ayant les propriétés d’une lame quart d’onde, en travaillant sur l’ellipticité des anneaux – pour générer une phase plasmonique – etdu trou central – pour compenser les forts effets de dichroïsme induits par l’absorption différentielle des plasmons de surface. / In this work, we studied the interaction between light with well-defined polarization and two subwavelength structures milled through an opaque metallic film by using the « Mueller matrix » method. In a first part, we showed that a subwavelength annular concentric slit array, milled completely through the film, allows the filtering and conversion of the incident polarization,generating a radial polarization after transmission. We also showed that it was possible to generate non-diffracting J0 or J2 Bessel beams through such structures and to control their helicity by changing the circular polarization either in preparation or in analysis. In a second part, we showed the creation of a plasmonic bull’s eye structure having the same properties as a quarter wave-plate, by acting on the ellipticities of the rings - to generate a plasmonic phase - and of the central hole - to compensate the strong dichroïsm induced by the differential surface plasmon absorption.
23

Rôle et impact des protéines associées à la lame basale spécialisée dans l’attache gingivale et la maladie parodontale

Fouillen, Aurélien 04 1900 (has links)
No description available.
24

Siekte en gebrokenheid teenoor genesing en restourasie in Johannes (Afrikaans)

Kok, Jacobus (Kobus) 07 November 2008 (has links)
In this dissertation the healing acts of Jesus in John are investigated against the ancient Mediterranean socio-religious and cultural background in which it realized. All sickness and healing realities realize within a particular socio-cultural context and may differ significantly within different cultures. For example, less than one hundred years ago depression was not diagnosed as an illness and there existed no therapeutic processes for the disease. When one investigates ancient healing narratives which tell of sickness realities almost 2000 years ago, before the dawn of the Western Bio-Medical research system and modernism, one must remember that the sickness realities of that time will differ to a great extent from the modern project‘s sickness realities and its constructs. The researcher must in other words be very sensitive about anachronistic misinterpretations and ethnocentrism - that is, a reductionistic view of sickness (and other) realities through your own worldview. For this reason the term sickness is used as an umbrella term, and a distinction is made between the curing of a disease and the healing of an illness. The word group curing and disease are words that are used in the Western Bio-Medical world, and are also deeply imbedded within the modernistic philosophical worldview. On the other hand the word group healing of an illness is more inclusive in the sense that it is sensitive to sickness realities as experienced and constructed in ancient Mediterranean societies. In the first century ancient Mediterranean temple oriented Judaism for example, a particular disease (like skin disease), unlike today, also had negative socio-religious implications for the afflicted person which sometimes resulted in marginalization and status deconstruction. Turning to John‘s healing narratives it should also be taken into account that his healing acts are presented as σημετα that is, signs which illustrate that Jesus is the Son of God, the source of life (cf. John 20:30-31; 10:32; 6:14). The question to be answered is, in what way does John present the healing narratives in order to illustrate that Jesus is the true source of Life (cf. John 1:4). The thesis is thus developed that John presents sickness realities that closely represent ¯"death”, crisis, disorientation, brokenness and loss of life possibilities within the ancient Mediterranean symbolic universe. John then presents Jesus as the divine transformation Agent, who restores and recreates life possibilities after a transformational interaction with the sick person. It is also argued that John‘s understanding of healing is not to be limited to the traditional Western Biomedical paradigm revolving around the curing of disease but also includes a view of Jesus‘ role as healer and restorer of spiritual brokenness, a tradition which originated in the Old Testament. The narrative regarding the discussion between Jesus and the Samaritan woman is used as an example of a situation in which Jesus offers someone the gift of life and spiritual restoration or healing which resulted in the representation of reality. Lastly it will be argued why the resurrection could be understood as a Johannine σημετον and also be interpreted as the culminating healing act in John‘s Gospel, illustrating that Jesus is the true source of life in abundance (cf. John 1:4; 10:10). / Thesis (PhD)--University of Pretoria, 2008. / New Testament Studies / PhD / Unrestricted
25

Étude des propriétés du moment angulaire orbital des ondes EM : développement de capteurs, transfert de moment et applications / Study of the properties of the orbital angular momentum of EM waves : development of sensors, transfer of moment and applications

Niemiec, Ronan 08 December 2014 (has links)
Une onde électromagnétique est définie par son amplitude, son vecteur d'onde, sa fréquence et son moment angulaire. Ce dernier peut être séparé en deux parties : la polarisation (associée au moment angulaire de spin), et le moment angulaire orbital. Ce dernier n'a vraiment été étudié qu'à partir de ces dernières années. Cette thèse a pour but d'approfondir les connaissances sur ce moment angulaire orbital. Des prototypes ont ainsi été réalisés, et des outils d'analyse ont été développés. Dans un premier temps, une étude du transfert de ce moment angulaire orbital à un objet macroscopique, à la fréquence de 870 MHz, est présentée. Une interprétation du mécanisme de transfert est ensuite proposée, supportée par le calcul des équations de champs et des simulations électromagnétiques. Dans un second temps, la conception et la réalisation de deux antennes, pouvant générer une onde possédant un moment angulaire orbital, sont présentées. Ces deux antennes utilisent une lame de phase avec une loi à dépendance angulaire. La première est une lame de phase dite « spirale », à permittivité constante et à hauteur variable. La seconde est une lame à gradient d'indice, à permittivité variable et à hauteur constante. Ces deux antennes ont été simulées, puis mesurées au sein de la chambre anéchoïque CHEOPS (DGA-MI, Bruz). Des cartographies sur un plan du champ ont ainsi été obtenues. Dans un dernier temps, la réflexion sur des surfaces courbes et planes, et l'influence de l'échantillonnage sur l'estimation des modes d'OAM, ont été étudiées. En ce qui concerne la réflexion, les résultats de simulations sont prometteurs, et semblent indiquer l'existence d'une relation entre les déformations du faisceau réfléchi et le type de surface. Pour l'estimation des modes d'OAM, les valeurs de champs sont extraites sur un cercle. Différents paramètres (positionnement et rayon du cercle) ont été considérés, et une méthode d'estimation des modes d'OAM sur une large bande de fréquence est proposée. / An electromagnetic wave is defined by its amplitude, its wave vector, its frequency and its angular momentum. This momentum can be decomposed into two components: polarization (associated to spin angular momentum), and orbital angular momentum. The later has not been investigated thoroughly until the last few years. To deepen the knowledge on orbital angular momentum, both prototypes and analysis tools have been developed in this thesis. First, study of orbital angular momentum transfer to a macroscopic object, at a frequency of 870 MHz, is presented. An interpretation of the transfer mechanism is then proposed, supported by the calculation of field equations and electromagnetic simulations. Secondly, the conception and the realization of two antennas able to generate an EM wave with orbital angular momentum are presented. These antennas use phase plates with an angular dependent law. The first one is a “spiral” phase plate, with constant permittivity and variable height. The second one has variable permittivity and constant height. Both have been simulated and characterized in CHEOPS anechoic chamber (DGA-MI, Bruz). Measurements of magnitude and phase, on a plane, have been obtained. Lastly, total reflection on planar and curved surfaces and influence of sampling on OAM modes estimation were investigated. Simulation results of reflected waves are promising and show a relationship between the induced deformations and the object reflected on. As for OAM modes estimation, study has been performed using an extraction circle on the wave front. Several parameters (center of the circle, radius) have been considered, and a method for OAM modes estimation on a large bandwidth is proposed.
26

Le Staffordshire Hoard : une interprétation d'après ses matériaux et ses techniques de fabrication

Côté, Cathy 08 1900 (has links)
Pour respecter les droits d'auteur, la version électronique de ce mémoire a été dépouillée de certains documents visuels. La version intégrale du mémoire a été déposée à la Division de la gestion des documents et des archives. / Le Staffordshire Hoard est un trésor anglo-saxon qui date des 6e et 7e siècles qui fut découvert en juillet 2009 par un détectoriste dans un champ du comté du Staffordshire en Angleterre. Ce trésor est composé d’environ 4600 fragments d’artéfacts représentant pour la plupart des garnitures d’épées en or et en argent. Bien que nous retrouvions aussi dans le Hoard certains objets ecclésiastiques, comme une grande croix en or ainsi qu’une bande inscrite en latin, aucune pièce de monnaie ne fut retrouvée, ni aucune lame d’épée. Le Staffordshire Hoard pose beaucoup de questions, notamment par sa composition inédite et aussi en raison du mauvais état dans lequel les objets furent retrouvés. Depuis sa découverte en 2009, les chercheurs se sont majoritairement posé les mêmes questions, à savoir de quel type de Hoard il s’agit, à qui il appartient et pourquoi il fut enterré. Avec ce mémoire, nous allons plutôt emprunter un autre chemin. En effet, nous étudierons plutôt les aspects matériels et techniques de la construction des artéfacts en or décorés avec la technique du cloisonné, et particulièrement le seax set. Ceci nous permettra dans un premier temps de comprendre comment ce type d’objet fut fabriqué par une société en particulier à l’époque du haut Moyen-Âge. Dans un second temps, l’étude de ces sujets aidera à répondre à une question qui fut souvent mise de côté par les différents chercheurs s’étant intéressés au Staffordshire Hoard, à savoir pourquoi aucune lame d’épée ne fut retrouvée dans cet assemblage. / The Staffordshire Hoard is an Anglo-Saxon treasure dating from the 6th and 7th centuries that was discovered in July 2009 by a detectorist in a field in the county of Staffordshire, England. This treasure is composed of approximately 4600 fragments of artefacts representing mostly gold and silver sword fittings. Although some ecclesiastical items were also found in the Hoard, such as a gold Great Cross and a Latin inscribed strip, neither coins nor sword blades were found. The Staffordshire Hoard raises many questions, due to its unusual composition and the poor condition in which the objects were found. Since its discovery in 2009, researchers have mostly asked the same questions, namely what type of hoard it is, to whom it belongs and why it was buried. With this dissertation, we will take a different path. Instead, we will study the material and technical aspects of the construction of gold artefacts decorated with the cloisonné technique, specifically the seax set. This will allow us in first place to understand how this type of object was made by a particular society in the early Middle Ages. Secondly, the study of these objects will help us to answer a question that has often been put aside by various researchers interested in the Staffordshire Hoard, namely why no sword blades were found in this assemblage.
27

On the quasi-optimal convergence of adaptive nonconforming finite element methods in three examples

Rabus, Hella 23 May 2014 (has links)
Eine Vielzahl von Anwendungen in der numerischen Simulation der Strömungsdynamik und der Festkörpermechanik begründen die Entwicklung von zuverlässigen und effizienten Algorithmen für nicht-standard Methoden der Finite-Elemente-Methode (FEM). Um Freiheitsgrade zu sparen, wird in jedem Durchlauf des adaptiven Algorithmus lediglich ein Teil der Gebiete verfeinert. Einige Gebiete bleiben daher möglicherweise verhältnismäßig grob. Die Analyse der Konvergenz und vor allem die der Optimalität benötigt daher über die a priori Fehleranalyse hinausgehende Argumente. Etablierte adaptive Algorithmen beruhen auf collective marking, d.h. die zu verfeinernden Gebiete werden auf Basis eines Gesamtfehlerschätzers markiert. Bei adaptiven Algorithmen mit separate marking wird der Gesamtfehlerschätzer in einen Volumenterm und in einen Fehlerschätzerterm aufgespalten. Da der Volumenterm unabhängig von der diskreten Lösung ist, kann einer schlechten Datenapproximation durch eine lokal tiefe Verfeinerung begegnet werden. Bei hinreichender Datenapproximation wird das Gitter dagegen bezüglich des neuen Fehlerschätzerterms wie üblich level-orientiert verfeinert. Die numerischen Experimente dieser Arbeit liefern deutliche Indizien der quasi-optimalen Konvergenz für den in dieser Arbeit untersuchten adaptiven Algorithmus, der auf separate marking beruht. Der Parameter, der die Verbesserung der Datenapproximation sicherstellt, ist frei wählbar. Dadurch ist es erstmals möglich, eine ausreichende und gleichzeitig optimale Approximation der Daten innerhalb weniger Durchläufe zu erzwingen. Diese Arbeit ermöglicht es, Standardargumente auch für die Konvergenzanalyse von Algorithmen mit separate marking zu verwenden. Dadurch gelingt es Quasi-Optimalität des vorgestellten Algorithmus gemäß einer generellen Vorgehensweise für die drei Beispiele, dem Poisson Modellproblem, dem reinen Verschiebungsproblem der linearen Elastizität und dem Stokes Problem, zu zeigen. / Various applications in computational fluid dynamics and solid mechanics motivate the development of reliable and efficient adaptive algorithms for nonstandard finite element methods (FEMs). To reduce the number of degrees of freedom, in adaptive algorithms only a selection of finite element domains is marked for refinement on each level. Since some element domains may stay relatively coarse, even the analysis of convergence and more importantly the analysis of optimality require new arguments beyond an a priori error analysis. In adaptive algorithms, based on collective marking, a (total) error estimator is used as refinement indicator. For separate marking strategies, the (total) error estimator is split into a volume term and an error estimator term, which estimates the error. Since the volume term is independent of the discrete solution, if there is a poor data approximation the improvement may be realised by a possibly high degree of local mesh refinement. Otherwise, a standard level-oriented mesh refinement based on an error estimator term is performed. This observation results in a natural adaptive algorithm based on separate marking, which is analysed in this thesis. The results of the numerical experiments displayed in this thesis provide strong evidence for the quasi-optimality of the presented adaptive algorithm based on separate marking and for all three model problems. Furthermore its flexibility (in particular the free steering parameter for data approximation) allows a sufficient and optimal data approximation in just a few number of levels of the adaptive scheme. This thesis adapts standard arguments for optimal convergence to adaptive algorithms based on separate marking with a possibly high degree of local mesh refinement, and proves quasi-optimality following a general methodology for three model problems, i.e., the Poisson model problem, the pure displacement problem in linear elasticity and the Stokes equations.
28

An Investigation of the ca. 2.7 Ga Late Archean Magmatic Event (LAME) in the Superior Province using 1-D Thermal Modelling

Ahmad, Seema 03 March 2010 (has links)
The Late Archean Magmatic Event (LAME), ca. 2.7 Ga, was the greatest crustal addition event in Earth history. My focus is the Superior Province of Canada, where LAME occurred ca. 2.75 – 2.65 Ga. Mantle plumes impinged on the Abitibi subprovince, where ~ 16 km regional thickness of tonalite-trondhjemite-granodiorite (TTG) melt was produced. Granites (sensu stricto) were the last magmatic phase of LAME, with a Superior-wide regional thickness of ~ 1 – 3 km. Assuming a crustal source for both TTG and granites, I use 1-D thermal models to investigate the origin of TTG in the Abitibi subprovince and that of late granites in the Superior Province. Melting curves appropriate to the source of TTG and granites are used to determine the thickness of melt produced in the models. I show that the incorporation of upward melt transfer into a standard model of lower crustal melting may increase the amount of predicted melt by ~ 1/(1-f), where f denotes the fraction of melt that is on average being extracted from the source rocks. Partitioning of heat producing elements between melt and restite reduces the amount of melt produced, but the effect is secondary compared to the increase in melt production through upward melt transfer. For the Abitibi subprovince, I show that the emplacement of a single plume coupled with the emplacement of a 12-km-thick greenstone cover can generate a maximum of ~ 9-km-thickness of TTG melt. However, the emplacement of a series of plumes, each coupled with the emplacement of a 3-km-thick greenstone cover and a 10-km-thick sill results in ~ 20-km-thickness of TTG melt. My model incorporates delamination of restitic eclogite. Finally, I show that late granites in the Superior Province may have resulted from thickening of a crust that had been “pre-heated” during earlier arc activity and that prolonged granitic magmatism observed in some areas of the Superior Province may be explained by late underthrusting of fertile source rocks into deeper and hotter regions of the crust.
29

An Investigation of the ca. 2.7 Ga Late Archean Magmatic Event (LAME) in the Superior Province using 1-D Thermal Modelling

Ahmad, Seema 03 March 2010 (has links)
The Late Archean Magmatic Event (LAME), ca. 2.7 Ga, was the greatest crustal addition event in Earth history. My focus is the Superior Province of Canada, where LAME occurred ca. 2.75 – 2.65 Ga. Mantle plumes impinged on the Abitibi subprovince, where ~ 16 km regional thickness of tonalite-trondhjemite-granodiorite (TTG) melt was produced. Granites (sensu stricto) were the last magmatic phase of LAME, with a Superior-wide regional thickness of ~ 1 – 3 km. Assuming a crustal source for both TTG and granites, I use 1-D thermal models to investigate the origin of TTG in the Abitibi subprovince and that of late granites in the Superior Province. Melting curves appropriate to the source of TTG and granites are used to determine the thickness of melt produced in the models. I show that the incorporation of upward melt transfer into a standard model of lower crustal melting may increase the amount of predicted melt by ~ 1/(1-f), where f denotes the fraction of melt that is on average being extracted from the source rocks. Partitioning of heat producing elements between melt and restite reduces the amount of melt produced, but the effect is secondary compared to the increase in melt production through upward melt transfer. For the Abitibi subprovince, I show that the emplacement of a single plume coupled with the emplacement of a 12-km-thick greenstone cover can generate a maximum of ~ 9-km-thickness of TTG melt. However, the emplacement of a series of plumes, each coupled with the emplacement of a 3-km-thick greenstone cover and a 10-km-thick sill results in ~ 20-km-thickness of TTG melt. My model incorporates delamination of restitic eclogite. Finally, I show that late granites in the Superior Province may have resulted from thickening of a crust that had been “pre-heated” during earlier arc activity and that prolonged granitic magmatism observed in some areas of the Superior Province may be explained by late underthrusting of fertile source rocks into deeper and hotter regions of the crust.
30

A ‘revision’ of Antonio Caro’s formative period : 1970—1976

Bossa, Paula 21 September 2011 (has links)
This thesis will examine the conceptual strategies articulated by a corpus of six works created within the first seven years of Colombian conceptual artist Antonio Caro’s career (1970-1976.) The works—Cabeza de Lleras (1970) [Head of Lleras], Aqui no cabe el arte (1972) [Art Does Not Fit Here], Manuel Quintín Lame información y variación visual (1972) [Manuel Quintín Lame, Information and Visual Variation], El imperialismo es un tigre de papel (1973) [Imperialism is a Paper Tiger], Colombia—Marlboro (1973-1975), and Colombia—Coca-Cola (1976)—despite stressing dematerialization, displaying simple designs, and communicating concise messages addressing political and cultural issues that are tied to a historical and geographic specificity, have been repeated until acquiring an iconic status. As a crucial tactic that is central to Caro’s work, this thesis will analyze both the advantages and disadvantages inherent in the strategy of repetition and how these have altered or enhanced the meaning of the works through time. Furthermore, five out of the six works in question employ text in a very particular way that results from Caro’s keen awareness of the visual potential of words. Likewise, they display anti-conventionalisms particularly with regards to the implementation of informal procedures (i.e. photocopying, posters, art actions, etc…) and the utilization of precarious materials (i.e. salt) that are often charged with historical meanings; the inherent short-lived nature of the materials used by Caro also points to the ephemeral quality of his production and to the rejection of the notion of art as a commodity. Finally, the works enact institutional critique on two fronts: they criticize the art institution from within, while simultaneously denouncing the politics of the state apparatus and the hegemonic values imposed by the dominant sectors of society. All in all, the salient features present in these six works point to Caro’s commitment to his environment while also contributing to the development of contemporary Colombian art. / text

Page generated in 0.0645 seconds