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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.
61

Erosões e dilatações morfológicas binárias seqüênciais rápidas / Fast sequential morphological binary erosions and dilations

Anderson Fraiha Machado 22 February 2008 (has links)
A Morfologia Matemática (MM) é um arcabouço geral para o estudo de mapeamentos entre imagens binárias. Estes estudos são de especial interesse na área de Processamento de Imagens. Tais mapeamentos entre imagens binárias são conhecidos como operadores de conjunto. Um aspecto importante da MM é a representação destes operadores em termos de dilatações, erosões e outras operações usuais de conjunto (interseção, união, complemento e diferença). Por este motivo, a dilatação e a erosão são ditos operadores morfológicos elementares. Este trabalho visa propor novos métodos para calcular a erosão e a dilatação morfológica binária rapidamente. Tais métodos se fundamentam em conceitos e técnicas de pré-processamento (em tempo linear) introduzidas por este trabalho, como a Transformada da Densidade, ou ainda, um Conjunto de Cascas. O resultado destes pré-processamentos é traduzido em ganho de velocidade dos algoritmos de erosão e dilatação, além de apresentar uma representação compacta dos conjuntos operandos. O consumo de tempo dos métodos propostos é no pior caso quadrático, porém, num estudo experimental preliminar, o algoritmo se comporta eficientemente, chegando a ser até mesmo linear em alguns casos. Além disso, um levantamento sucinto de outros métodos de erosão e dilatação morfológica binária conhecidos pela literatura atual é apresentado. Algumas simulações e uma breve análise de complexidade mostram que os métodos propostos são boas alternativas para implementação de erosão e dilatação morfológica eficiente. / A Mathematical Morphology (MM) is a general framework for the study of mappings between binary images. These studies are of particular interest in the area of Image Processing. Such mappings between binary images are known as set operators. An important aspect of MM is the representation of these operators in terms of dilations, erosions and other usual set operations (intersection, union, complement and difference). For that reason, the dilation and erosion are called elementary morphological operators. This work aims to propose new methods to calculate the morphological binary erosion and dilation quickly. Such methods are based on concepts and techniques of preprocessing (in linear time) introduced by this work, as the density transformed, or even a set of shells. The result of these preprocessing translates into speedup of erosion and dilation algorithms, and present a compact representation of the operands sets. The time complexity of the proposed methods is quadratic in the worst case, however, a preliminary experimental study, the algorithm behaves efficiently, becoming even linear in some cases. Furthermore, a brief survey of other methods of morphological erosion and binary dilation known by current literature is presented. Some simulations and a brief complexity analysis shows that our methods are a good alternative for implementation of erosion and dilation morphological efficient.
62

Stabilité chimique et structurale de pérovskites céramiques de conductrice protoniques pour piles à combustible et électrolyseurs / Chemical and structural stability of proton conducting perovskite ceramic for fuel cells and electrolyzers

Upasen, Settakorn 10 September 2015 (has links)
La stabilité structurale et chimique de céramiques bien densifiées candidates pour leur utilisation comme électrolyte ou matériau d'électrode de piles à combustible, électrolyseur H2/air ou même de convertisseur CO2/Hydrocarbures a été étudiée vis-à-vis de l'eau sous pression (autoclave, eau pauvre ou saturée en CO2). La pressurisation maximise l'efficacité des dispositifs. Quatre familles de pérovskites ont été considérées: BaCe0.4Zr0.5Y0.1Zn0.04O3- (BCZYZ), SrZr0.9Er0.1O3- (SZE), Ln2NiO4+ (LNO, Ln = La, Pr, Nd), and La0.6Sr0.4Co0.2Fe0.8O3- (LSCF6428). Les céramiques denses sont traitées à 550°C en autoclave plusieurs jours à plusieurs semaines, soit dans des conditions de fonctionnement ( 20 bar, eau sans CO2, 550°C), soit en vieillissement accéléré ( 40 bar eau sans ou saturée de CO2, 550°C). Les céramiques ont été analysées avant et après 'protonation' par Microscopie Optique, Thermogravimétrie, Expansion Thermique, (micro/macro) ATR FTIR, Raman micro-Spectroscopie, diffraction des rayons X et des neutrons. En condition de fonctionnement ( 20 bar), la stabilité des matériaux d'électrodes LNO/LSCF6428 et de l'électrolyte SZE est bonne, alors que la céramique BCZYZ se corrode. La céramique LSFC6428 soumis à des conditions sévères (eau saturée en CO2, 40 bar) est 5 à 30 fois moins corrodée que les composés LNO and SZE. La corrosion s'initie en surface, aux joints de grains. La protonation modifie plus ou moins la symétrie, le volume et les paramètres de la maille unitaire ainsi que les transitions de phase en relation avec la modification de la distribution/organisation des lacunes d'oxygène. Le niveau de dopage en proton des différents matériaux est aussi discuté. / The chemical and structural stability of well-densified ceramics potentially used as H2/air fuelcell/electrolyzer (and perhaps in CO2/Hydrocabons Converter) electrolyte or electrodes vs. CO2-free/saturated pressurized water has been studied. The pressurization maximizes the efficiency of theenergy conversion systems. Four types of pervoskite-related oxide ceramics were concerned:BaCe0.4Zr0.5Y0.1Zn0.04O3-d (BCZYZ), SrZr0.9Er0.1O3-d (SZE), Ln2NiO4+d (LNO, Ln = La, Pr, Nd), andLa0.6Sr0.4Co0.2Fe0.8O3-d (LSCF6428). Dense ceramic samples were exposed at 550°C to water vaporpressure in an autoclave for days to weeks. The protonation treatments were performed in twodifferent conditions: operating condition (£20 bar of CO2-free water pressure, 550°C) and acceleratedaging conditions (³40 bar of CO2-free/CO2-saturated water pressure, 550°C). The pristine and‘protonated’ samples were characterized using various analysis techniques: Optical Microscopy,Thermogravimetry, Thermal Expansion, (micro/macro) ATR FTIR, Raman micro-spectroscopy, X-rayand Neutron Scattering. The study reveals that under the operating condition (£20 bar), the stability ofLNO/LSCF6428 electrode materials and of SZE electrolyte appears good, while the BCZYZelectrolyte exhibit significant corrosion. The superior stability of LSFC6428 exposed in extreme CO2-water vapor atmosphere was demonstrated about 5 to 30 times better than LNO and SZE homologues.The surface secondary phases form at the grain boundary. The protonation modifies more or less thestructure symmetry, the unit-cell volume/parameter and the phase transition sequence in relation withthe modification of the oxygen vacancy distribution. The proton doping level for different samples isalso discussed.
63

Comportement thermomécanique de composites réfractaires oxyde-carbone / Thermomechanical behavior of oxide-carbon refractory composites

Dupuy, Diane 18 December 2015 (has links)
Cette thèse avait pour objectif d’étudier les relations existant entre la microstructure de réfractaires alumine-carbone utilisés en coulée continue dans l’industrie sidérurgique et leurs propriétés thermomécaniques. Le travail réalisé ici s’inscrit dans une logique composite, en déterminant les propriétés thermomécaniques des constituants séparément et en analysant ensuite les propriétés des matériaux multiphasiques. Différents systèmes de matériaux modèles ont été étudiés en s’intéressant à deux échelles : agrégats et matrice. Ces matériaux sont constitués d’une part, d’un squelette de graphite et d’agrégats d’alumine et d’autre part d’une matrice carbonée chargée en petits grains d’alumine. La liaison carbone de ces matériaux résultant de la pyrolyse d’une résine phénolique, les propriétés thermomécaniques des matériaux modèles élaborés ont été analysées à la fois pendant et après le traitement thermique de pyrolyse. L’évolution des propriétés au cours de la pyrolyse des échantillons réticulés a mis en évidence l’apparition d’un léger endommagement en fin de montée en température, et un endommagement plus prononcé lors du refroidissement. Cet endommagement résulte d’un différentiel de dilatation thermique entre les grains d'alumine et la liaison carbone. L'influence de ces effets microstructuraux sur le comportement mécanique des matériaux pyrolysés a été étudiée grâce à des essais de traction, mettant en évidence un comportement non-linéaire assez marqué. Des relations entre la fraction volumique et les propriétés physiques clés des matériaux ont pu être établies. Par ailleurs, les résultats obtenus ont montré qu’un changement de composition relativement peu important peut modifier radicalement les propriétés thermomécaniques de ces matériaux. Cette étude sur des matériaux modèles a permis de dégager des pistes pour une amélioration des compositions industrielles. / The present thesis aimed at investigating the relationships existing between the microstructure of alumina-carbon refractories used in steel continuous casting and their thermomechanical properties. The work realized here fall within a composite approach, by determining thermomechanical properties of the single constituents of the materials and analyzing then the properties of the heterogeneous composites. Different systems of double scale model materials, constituted of graphite and alumina aggregates in one hand, and of carbon matrix loaded with fine alumina grains on the other hand were studied here. The carbon bond of these materials resulting from pyrolysis of phenolic resin, the thermomechanical properties of the elaborated model materials were analyzed both during and after the pyrolysis heating treatment. The properties evolutions of the cured samples during the pyrolysis highlighted a slight damage during the end of heating and important damage during cooling, due to a thermal expansion mismatch between the alumina grains and the resin/carbon bond. The influence of the thermal damage has been investigated thanks to tensile tests on the pyrolyzed materials, which exhibit a rather strong non-linear behavior. Relationships between volume fraction and physical key-properties of the materials have been established. Besides, the obtained results highlighted that a small change in composition can drastically change the thermomechanical properties of these materials. This overall study on model materials allowed to develop some ideas in order to improve industrial compositions.
64

The cost-effectiveness of introducing Manual Vacuum Aspiration compared to Dilatation and Curettage for incomplete first trimester abortions at a tertiary hospital in Manzini, Swaziland

Maonei, Costa January 2013 (has links)
Background: Despite proven efficacy, Manual Vacuum Aspiration (MVA) use for incomplete abortions is low in the Swaziland setting, including Raleigh Fitkin Memorial (RFM) Hospital. Uncertainty in the costs implications of introducing MVA to replace Dilatation and Curettage (D&C) is the major hindrance to change. This study aimed to evaluate the cost-effectiveness of introducing MVA as an evacuation method for first trimester incomplete miscarriages as well as assess the implications of the introduction of MVA to the entire post-abortion care budget at RFM Hospital. Methods: The methods comprised cost-effectiveness and budget impact analyses from a healthcare perspective based on a theoretical cohort. Clinical outcomes data for procedures were obtained from relevant literature. Costs were collated from prospective suppliers and then compared for the two treatment modalities. Future numbers of annual evacuations were extrapolated from previous annual figures. First trimester miscarriages were in turn extrapolated from proportions found in previous studies. Total budgets were calculated under the current scenario, as well as if MVA had to be introduced. Results: With initial capital costs of ZAR11 093.00, introduction of MVA for first trimester incomplete abortions will cut post-abortion care costs by 34.7%. MVA would cost ZAR819.86 per procedure while D&C costs ZAR1 255.40 per procedure. An estimated 26 MVA procedures done instead of D&C will compensate for the initial capital investment. Introduction of MVA into the post-abortion care programme will save the hospital about ZAR516 115.30 annually, with at least similar clinical outcomes compared to D&C. Conclusions: MVA should be considered as the first option in first trimester post abortion care. / Dissertation (MSc)--University of Pretoria, 2013. / gm2014 / Clinical Epidemiology / unrestricted
65

Influence des propriétés physico-mécaniques des minéraux argileux dans l'altération de la pierre monumentale / Influence of the physico-mechanical properties of clay minerals on stone deterioration

Tiennot, Mathilde 31 March 2017 (has links)
La desquamation en plaque est une forme de dégradation de la pierre monumentale fréquemment observée. Cette morphologie spécifique résulte de l’initiation et la propagation d’une fissure subparallèle à la surface, qui subit diverses sollicitations en conditions naturelles d’exposition. L’objectif de cette recherche est de mieux comprendre ces mécanismes d’altération et d’appréhender les paramètres déterminants dans l’initiation de la fissuration au sein des pierres mises en œuvre. Une approche en mécanique de la rupture a ainsi été proposée. L’influence des minéraux argileux, mis en cause dans ce phénomène, est étudiée et discutée. Trois pierres ont été sélectionnées, une molasse, un grès et une kersantite, présentant de nombreux exemples de desquamation lorsqu’elles sont exposées. Leur comportement hydromécanique est caractérisé en tenant compte de leur anisotropie naturelle. Les propriétés élastiques, la résistance à la traction et la ténacité sont mesurées après saturation, pour plusieurs humidités relatives en phase d’humidification et de séchage, et après plusieurs cycles de variations d’humidité relative. Un couplage de mesure des dilatations et des vitesses d’ondes acoustiques a permis un suivi précis de l’endommagement au fil des cycles. L’influence des minéraux argileux dans les processus d’altération a pu être vérifiée. Ces phases ont été identifiées comme des facteurs essentiels de la dégradation, car elles constituent des plans de fragilité favorisant l’endommagement et la fissuration du matériau, et ce d’autant plus qu’elles se dilatent lors des sollicitations naturelles. / Flaking is a deterioration pattern widely observed on monumental stone heritage. This pattern is due to the initiation and propagation of a crack subparallel to the surface of the stone exposed to natural weathering. This research aims to better understand the alteration mechanisms and to determine the parameters involved in such crack initiation within monumental stones. A fracture mechanics approach is proposed and the influence of clay minerals on this detachment alteration is discussed. The research is carried out on three stones, a molasse, a sandstone and a kersantite, showing scaling effect when submitted to natural conditions. Their hydromechanical behaviour is studied with respect to their natural anisotropy. Elastic properties, tensile strength and toughness are measured after saturation, at various RH values during humidification and drying, and after several cycles. Wave propagation combined with dilatation measurements is used to follow damage during the RH variations cycles. The influence of clay minerals on alteration processes is verified. These phases are critical factors of stone degradation as they are weakness planes leading to damage and cracking, especially generated by their swelling.
66

Mécanismes de l’angiogénèse bronchique et de la synthèse de VEGF par l’épithélium respiratoire dans les dilatations des bronches. / Mechanisms of bronchial angiogenesis and VEGF airway epithelial synthesis in bronchiectasis : roles of Pseudomonas aeruginosa bronchial infection and CFTR defect.

Martin, Clémence 06 December 2010 (has links)
L'hypervascularisation artérielle bronchique des dilatations des bronches contribue à l'afflux local de cellules inflammatoires et de protéines plasmatiques et favorise la survenue de saignements bronchiques. Les mécanismes de l'angiogénèse des vaisseaux bronchiques dans les dilatations des bronches sont peu connus, mais pourraient impliquer la voie du facteur de croissance endothélial (VEGF)-A.Nous avons émis l'hypothèse que l'infection bronchique dans les dilatations des bronches contribue à l'angiogénèse des vaisseaux bronchiques. Nous avons développé chez la souris un modèle d'infection bronchique persistante par l'instillation intratrachéale de billes d'agarose contenant du Pseudomonas aeruginosa. Nos résultats indiquent que l'infection bactérienne provoque l'angiogénèse des vaisseaux péribronchiques en 7 jours. P. aeruginosa induit la synthèse de VEGF-A par l'épithélium respiratoire in vitro et chez la souris par l'activation du récepteur de l'epidermal growth factor (EGF).Nous avons ensuite évalué l'effet de la perte de fonction de CFTR, l'anomalie caractéristique de la mucoviscidose (une cause génétique de dilatation des bronches), sur l'angiogénèse bronchique et l'expression de facteurs pro-angiogéniques. Ces études ont été menées à partir de poumons de patients mucoviscidosiques, chez des souris mutées pour le gène cftr et par inhibition de CFTR sur des cultures de cellules épithéliales.Nos données indiquent que l'infection bronchique contribue à l'angiogénèse péribronchique, qui nécessiterait une communication épithélium/endothélium. L'épithélium bronchique de la mucoviscidose est dans un état pro-angiogénique en l'absence d'infection. / Abnormal proliferation of bronchial arteries in subjects with bronchiectasis contributes to the recruitment of inflammatory cells and plasma protein within the airways, and promotes endobronchial bleeding. Mechanisms of bronchial angiogenesis in bronchiectasis are largely unknown, but could implicate the vascular endothelial growth factor (VEGF)-A pathway.We hypothesized that bronchial infection that occurs in bronchiectasis contributes to angiogenesis of bronchial blood vessels. We developed a mouse model of persistent bronchial infection by intratracheal instillation of agarose beads containing Pseudomonas aeruginosa. Our results indicate that bacterial infection promotes angiogenesis of peribronchial blood vessels within 7 days. Further, P. aeruginosa induces VEGF-A synthesis in airway epithelium in vitro and in mouse in vivo via activation of the epidermal growth factor (EGF) receptor.Next we examined the role of CFTR defect, associated with cystic fibrosis (CF, a genetic cause of bronchiectasis), on bronchial angiogenesis and expression angiogenic growth factors. These studies were conducted using lung tissues obtained in CF subjects, in various strains of mice mutated for the cftr gene, and by inhibition of CFTR function in cultured airway epithelial cells.Our data indicate that bronchial infection contributes to peribronchial angiogenesis, which probably necessitate interaction of epithelial and endothelial cells. Cystic fibrosis airway epithelium may exhibit a pro-angiogenic phenotype in the absence of infection.
67

Golfový klub / Golf club

Sedláčková, Markéta January 2015 (has links)
The subject matter of my Diploma thesis is the project of a new golf club. The building has one floor and is covered by a flat mono-coated roof. Spacious terraces accessible from first floor are the integral parts. Vertical load bearing and non-load bearing walls are designed from Porotherm walling system. Horizontal load bearing ceiling constructions are designed from an prestressed ceiling panels Spiroll. Foundations are designed reinforced concrete. The building is divided into two separate operating units. The project emphasizes the layout plan, thermal technical properties and safety in use.
68

Součinitele přestupu tepla na parou obtékaných plochách parních turbín / Heat transfer coefficient on surfaces of steam turbines

Belko, Milan January 2013 (has links)
This thesis in introductory part aims to analyze the available literature on the heat transfer coefficient in labyrinth seals and rotating discs of steam turbines. The available experiment studies were processed to summarize heat transfer coefficients on the rotating parts of the turbine. Then, this thesis specifies a design calculation to determine the heat transfer coefficient in selected parts of the turbine, exercisable for specific geometric and operating parameters. The outcome of this work is simulation of rotor dilation of operating steam turbine in the program Ansys during cold start of turbine.
69

The importance of central airway dilatation in patients with bronchiolitis obliterans / 閉塞性細気管支炎患者における中枢気管支拡張の意義

Kogo, Mariko 23 March 2023 (has links)
京都大学 / 新制・課程博士 / 博士(医学) / 甲第24501号 / 医博第4943号 / 新制||医||1064(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 永井 洋士, 教授 大鶴 繁, 教授 江木 盛時 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
70

Paclitaxel alters the function of the small diameter sensory neurons

Gracias, Neilia 08 July 2011 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Although paclitaxel is a commonly used anti-neoplastic agent for the treatment of solid tumors, therapy often results in a number of side effects, the most debilitating of which is peripheral neuropathy. Peripheral neuropathy is defined as a pathology of peripheral nerves, and, depending on the type of nerves damaged, the neuropathy can be classified as sensory, motor, or autonomic neuropathy. In the case of peripheral neuropathy induced by paclitaxel, the symptoms are experienced in the extremities and are sensory in nature. Patients undergoing chemotherapy with paclitaxel often report sensory disturbances such as burning, tingling, numbness, a diminished sensation to pain and temperature, loss of vibration sense, loss of proprioception, and loss of deep tendon reflexes. Electrophysiological abnormalities including decreased sensory nerve action potential amplitude and conduction confirm damage to large myelinated fibers. However, the involvement of damage to small diameter sensory neurons in the etiology of paclitaxel – induced peripheral neuropathy is still controversial. Therefore, experiments were performed to determine if paclitaxel alters the function of small diameter sensory neurons and to examine the mechanisms responsible for the change in function. vi Sensory neuron mediated vasodilatation in paclitaxel – injected animals was examined as an indirect measure of calcitonin gene related peptide (CGRP) release and therefore of sensory neuron function. CGRP release was also directly measured from central terminals in the spinal cord. To examine mechanisms of paclitaxel – induced sensory neuron damage, CGRP release and neurite length was examined in paclitaxel – treated sensory neurons in culture. The results demonstrate that (1) paclitaxel decreases the ability of small diameter sensory neurons to produce an increase in blood flow in the skin; (2) paclitaxel alters the release of CGRP from the small diameter sensory neurons; (3) paclitaxel causes the neuronal processes of isolated sensory neurons to degenerate. This dissertation provides novel information showing that paclitaxel alters the function of small diameter sensory neurons and thus provides a better understanding of the mechanisms mediating the sensory disturbances characteristic of peripheral neuropathy resulting from chemotherapy with paclitaxel.

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