Abstract From the viewpoint of Micro politics in school organizations, the purpose of this study is to investigate the relevancies between the perceptions of micro politics strategies and the levels of organizational trust among the teachers with variable backgrounds in school organizations in Pingtung County. The research method being adopted in this study is Questionnaire Survey and the research tool being utilized is ¡§The Questionnaire Survey on the Perceptions of micro politics Strategies and the Levels of Organizational Trust in School Organizations in Pingtung County¡¨, developed by the researcher himself. After reviewing relevant research documents and analyzing the results of the questionnaire survey, the conclusions of this study include: 1.There is obvious existence of micro politics strategies in the relationship operations in school organizations. 2.Among teachers and schools of different backgrounds, there are notable differences in the perceptions of micro politics strategies in school organizations. 3.Among teachers and schools of different backgrounds, there are notable differences in some aspects in the levels of organizational trust in school organizations. 4.It is shown that there is a low positive correlation between the perceptions of micro politics and the levels of organizational trust in school organizations.

This study presents a novel polyimide-based self-assembly three dimensional micro blade using surface micromachining technology for the development of micro-fan chip. The high surface-tension-force of reflowed polyimide has can be used to lift the free-standing micro blade. In addition, the thesis introduces a micro hinge structure to effectively limit the maximum lifting angle of the micro blade and to accurately lock hinge-pin into the vertical position. Many parameters have been investigated its influence on the surface-tension- force of polyimide, including the thickness of polyimide and the temperature/time in reflow processing. Based on the experimental results, 18 £gm-thick polyimide can lift the micro blade at 70¢X angle under 380 ¢J/10 hrs reflow condition. On the other hand, 25 £gm-thick polyimide has demonstrated its maximum lifting angle can be achieved to 130¢X utilizing the very high surface-tension-force induced by over contraction and deformation when it was reflowed at higher temperature (400 ¢J). Finally, this dissertation has studied the relation between the position of polyimide elastic-joint and the deflection angle (£r). Furthermore, this thesis has successfully demonstrated a novel multi-joint and asymmetrical microstructure for the development of the spiral and out-of-plane 3D micro blade.

Product miniaturization is a long-term trend. Mechanical micro-machining is a suitable technique for manufacturing of microstructures characterized by cheap equipments, less working time, and possible complex geometry. For the requirements for high precision manufacture, the use of minimum/minimal quantity lubrication (MQL) is a good strategy for micro-machining due to long tool life and high product accuracy. This study presents an experimental investigation of the MQL in micro milling. The tool wear, surface roughness, and burr formation are observed at different feeds (1 £gm/rev, 1.5 £gm/rev, and 2 £gm/rev) and cutting speeds ( 37.7 m/min, 56.55 m/min, and 75.4 m/min) under dry and MQL cutting. Unlike conventional milling, greater tool wear is observed at lower feeds. Compared with the same cutting condition for dry cutting (feed 2 £gm/rev, cutting speed 56.55 m/min), MQL can reduce the tool wear about 56%. In terms of the consumption of the cutting fluid, oil flow rate of 1.88 ml/h is sufficient for reducing the tool wear in micro milling. According to the experimental results, deterioration of surface finish and burr formation are closely related to the tool wear. The use of MQL, not only reduces the tool wear, but also diminishes the deterioration of surface finish (the improvement of Ra is at least 0.6 £gm) and the burr formation.

No description available.

Using a Panasonic MG-72 Micro Electro-Discharge Machine, techniques and procedures are developed to fabricate complex microstructures in conductive materials and engineered ceramics.

In the area of translational research, stent developers consult pathologists to obtain the best and most complete amount of data from implanted test devices in the most efficient manner. Through the use of micron-scale computed tomography along with post-fixation staining techniques in this study, full volumes of previously implanted stents have been analyzed in-situ in a non-destructive manner. The increased soft tissue contrast imparted by metal-containing stains allowed for a qualitative analysis of the vessel’s response to the implant with greater sensitivity and specificity while reducing beam-hardening artifact from stent struts. The developed staining techniques included iodine-potassium iodide, phosphomolybdic acid, and phosphotungstic acid, all of which bind to soft tissue and improve image quality through their ability to attenuate high energy X-rays. With these stains, the overall soft tissue contrast increased by up to 85 percent and contrast between medial and neointimal layers of the vessel increased by up to 22 percent. Beam hardening artifact was also reduced by up to 38 percent after staining. Acquiring data from the entirety of the stent and the surrounding tissue increased the quality of stent analysis in multiple ways. The three dimensional data enabled a comprehensive analysis of stent performance, lending information such as neointimal hyperplasia, percent stenosis, delineation of vessel wall layers, stent apposition, and stent fractures. By providing morphological data about stent deployment and host response, this method circumvents the need to make the more traditional histology slides for a morphometric analysis. These same data may also be applied to target regions of interest to ensure histology slides are cut from the optimal locations for a more in-depth analysis. The agents involved in such techniques are readily available in most pathology laboratories, are safe to work with, and allow for rapid processing of tissue. The ability to forego histology altogether or to highly focus what histology is performed on a vessel has the potential to hasten the development process of any coronary stent.

Nous avons abordé dans le cadre de ce travail de thèse diverses problématiques fondamentales qui touchent tout d’abord à l’élaboration de nouveaux polymères à propriétés viscoélastiques contrôlées (exemple : variation du module de Young pour de basses fréquences) et ensuite aborder l’intégration de ces matériaux dans des capteurs ou actionneurs de petites dimensions. Les études amont abordées dans ce travail de thèse nous ont permis de constituer un socle solide de connaissances pour le développement de nouveaux dispositifs mettant en jeu par exemple des matrices de micro-actionneurs ou micro-capteurs sur des substrats souples en polymère. Ces aspects applicatifs sont développés dans le cadre de projets collaboratifs menés avec des partenaires académiques. Dans le cadre de ce travail de thèse, nous avons conçu, fabriqué et caractérisé des matériaux polymères micro-structurés. Nous avons chargé ces matériaux micro-structurés pour obtenir des matériaux avec un comportement piézoélectrique. Ces matériaux sont caractérisés en piézoélectricité indirecte par la spectroscopie d’impédance pour étudier la stabilité thermique de la piézoélectricité dans ces structures. Nos matériaux ont montré une réponse piézoélectrique importante avec un coefficient piézoélectrique longitudinal de 350pC/N. La piézoélectricité est maintenue sur une large gamme de température allant de -25°C à 85°C. Des améliorations ont été réalisées en chargeant les structures à hautes températures comparées aux structures chargées à la température ambiante. Par la suite, Nous avons testé électro-mécaniquement ces structures, ces dernières ont montré des coefficients piézoélectriques importants dans la gamme de fréquence de 1Hz à 100Hz pouvant ainsi couvrir toutes les fréquences de résonance des vibrations existant dans notre vie quotidienne. Des études ont été menées pour les caractérisations diélectriques par la spectroscopie d’impédance des structures non-chargées. De plus des caractérisations des polymères viscoélastiques par DMA (Dynamic Mechanical Analyzer) afin d’obtenir le comportement fréquentiel de leur module de Young. Les résultats expérimentaux sont analysés en lien avec les propriétés structurales des matériaux. Un prototype a été réalisé afin d’étudier la faisabilité d’un accéléromètre ou un récupérateur d’énergie avec les matériaux ainsi obtenus. / We studied within this working thesis various fundamental issues that affect the development of new controlled viscoelastic polymer properties (eg variation of Young's modulus at low frequencies) and then the integration of these materials in sensors.Preliminary studies discussed in this thesis allowed us to build a solid knowledge for the development of new devices involving such micro-actuator arrays or micro-sensors on flexible substrates in polymer. These applications areas are developed through collaborative projects with academic partners.As part of this thesis, we have designed, fabricated and characterized micro-structured polymer materials. We charged these micro-structured materials for a piezoelectric material with behavior. These materials are characterized in inverse piezoelectric mode by the dielectric resonance spectroscopy to study the thermal stability of piezoelectricity in these structures. Our materials showed a significant response with a longitudinal piezoelectric coefficient of 350pC/N. Piezoelectricity is maintained over a wide temperature range from -25 ° C to 85 ° C. Improvements were carried out by charging the structures to high temperatures compared to structures responsible at room temperature.Subsequently, we tested electro-mechanically these structures, the latter showed significant piezoelectric coefficients in the frequency range of 1Hz to 100Hz and can cover all the resonance frequencies of the vibrations existing in our daily life.Studies were realized on the dielectric characterization by impedance spectroscopy of the uncharged structures. In addition, characterizations of the viscoelastic polymers by DMA (Dynamic Mechanical Analyzer) to obtain the frequency behavior of their Young's modulus. The experimental results are analyzed in relation to the structural properties of the materials.A prototype was realized to study the feasibility of an accelerometer or an energy harvester with the obtained materials.

Le domaine des écrans est en pleine mutation. De nouvelles technologies d’écrans (principalement LCD et OLED) ont remplacé l’écran à tube cathodique du XXème siècle et ouvrent la voie vers de nouvelles fonctionnalités (écran 3D, flexible, transparent). Depuis quelques années, un genre particulier d’écran fait l’objet de nombreuses recherches, notamment pour adresser de nouveaux marchés tels que la réalité augmentée : les micro-écrans. Pour cela, les contraintes technologiques sont fortes. L’écran doit être miniature (quelques millimètres de diagonale) tout en permettant une qualité d’image semblable aux écrans traditionnels. Il doit aussi être compact, économe en énergie et très lumineux. Une nouvelle technologie d’écran est à l’étude depuis quelques années et doit permettre d’atteindre ses spécifications. Il s’agit des micro-écrans LED, constitués d’un réseau de LED micrométriques, dans lequel chaque diode constitue un pixel de l’image. L’objectif de cette thèse est d’étudier les spécificités des matrices de LED en nitrure de gallium (GaN) en vue de leur utilisation dans des micro-écrans.Les recherches menées au cours de cette thèse portent sur trois axes d’étude. Le premier concerne l’optimisation du rendement à travers l’étude du procédé de matriçage d’une épitaxie LED. L’amélioration de la métallisation P et de l’intégrité électrique du P-GaN a permis d’augmenter le rendement d’un facteur 10 sur les micro-LED. Le deuxième axe de travail concerne l’étude des effets de taille. La réduction de la taille des LED entraine une forte baisse du rendement maximum. Les études menées ont permis l’attribuer principalement à des recombinaisons non-radiatives sur les bords de pixel. Le troisième axe de recherche porte sur l’étude des micro-LED en tant que réseau bidimensionnel permettant la formation d’images. Les principales sources d’inhomogénéité et de dispersion ont été étudiées. Des solutions ont été proposées pour éliminer le cross-talk optique et améliorer l’extraction lumineuse, principal frein au rendement de nos micro-LED. Enfin, des micro-écrans LED fonctionnels, bleus et verts, à l’état de l’art mondial ont été obtenus et caractérisés au cours de cette thèse / The display industry is facing a fast transformation. New technologies (mainly LCD and OLED) have faded-out the cathode ray tube of the 20th century and lead to new applications (3D, flexible and transparent displays). A very particular type of display has recently emerged to address new markets, such as augmented reality: micro-displays. They can be defined as having a diagonal of around 1 inch or less. One important goal of these micro-displays is to deliver the same image quality as conventional, larger-size displays. Strong challenges arise in terms of definition, compactness, consumption and brightness. To address these, LED micro-displays are currently being studied. In a LED micro-display, a 2D-array of micro-LEDs is fabricated, where each LED acts as a single pixel of a whole image. The main objective of this thesis work is to study the specifics of Gallium Nitride (GaN) micro-LEDs arrays for micro-display applications.Our investigations have been carried out focusing on three major areas of study. Increasing LED efficiency through the study of our fabrication process was the first goal. By improving P metal and enhancing P-GaN electrical performances, we were able to increase efficiency of micro-LED by a factor of 10.The influence of size-reduction on the performances of LEDs have then been thoroughly investigated. As LED size decreases, its maximum efficiency drops. Non-radiative recombinations occurring at the edges of the LED were found to be the main origin. We have then studied LEDs, not as a single diode, but as a dense 2D array of micro-LEDs allowing image display, and optical and electrical spread have been investigated. Furthermore, optical cross-talk has been studied and fabrication was changed to address this issue. New structures have also been suggested to improve light extraction efficiency, which is one of the main hindrance towards high-efficiency micro-LEDs. Finally, state-of-the-art, blue and green, active matrix micro-LED displays have been obtained and characterized during the course of this thesis work.

Les récentes évolutions en microélectronique nécessitent une attention particulière lors de la conception d’un circuit. Depuis les noeuds technologiques de quelques dizaines de nanomètres, les contraintes de consommation deviennent prépondérantes. Pour répondre à ce problème, les concepteurs se penchent aujourd’hui sur l’utilisation d’architectures multi-coeurs hétérogènes incluant des accélérateurs matériels dotés d’une grande efficacité énergétique. Le maintien des spécifications d’un circuit apparait également essentiel à l’heure où sa fabrication est de plus en plus sujette à la variabilité et aux défauts. Il existe donc un réel besoin pour des accélérateurs robustes. Les architectures neuromorphiques, et notamment les réseaux de neurones à impulsions, offrent une bonne tolérance aux défauts, de part leur parallélisme massif, et une aptitude à exécuter diverses applications à faible coût énergétique. La thèse défendue se présente sous deux aspects. Le premier consiste en la conception d’un neurone analogique robuste et à son intégration dans un accélérateur matériel neuro-inspiré à des fins calculatoires. Cet opérateur mathématique à basse consommation a été dimensionné puis dessiné en technologie 65 nm. Intégré au sein de deux circuits, il a pu être caractérisé dans l’un d’entre eux et ainsi démontrer la faisabilité d’opérations mathématiques élémentaires. Le second objectif est d’estimer, à plus long terme, l’impact des nouvelles technologies sur le développement de ce type d’architecture. Ainsi, les axes de recherches suivis ont permis d’étudier un passage vers un noeud technologique très avancé, les opportunités procurées par des Through-Silicon-Vias ou encore, l’utilisation de mémoires résistives à changement de phase ou à filament conducteur. / Due to the latest evolutions in microelectronic field, a special care has to be given to circuit designs. In aggressive technology nodes down to dozen of nanometres, a recent need of high energy efficiency has emerged. Consequently designers are currently exploring heterogeneous multi-cores architectures based on accelerators. Besides this problem, variability has also become a major issue. It is hard to maintain a specification without using an overhead in term of surface and/or power consumption. Therefore accelerators should be robust against fabrication defects. Neuromorphic architectures, especially spiking neural networks, address robustness and power issues by their massively parallel and hybrid computation scheme. As they are able to tackle a broad scope of applications, they are good candidates for next generation accelerators. This PhD thesis will present two main aspects. Our first and foremost objectives were to specify and design a robust analog neuron for computational purposes. It was designed and simulated in a 65 nm process. Used as a mathematical operator, the neuron was afterwards integrated in two versatile neuromorphic architectures. The first circuit has been characterized and performed some basic computational operators. The second part explores the impact of emerging devices in future neuromorphic architectures. The starting point was a study of the scalability of the neuron in advanced technology nodes ; this approach was then extended to several technologies such as Through-Silicon-Vias or resistive memories.

Orientador: Marcia Carneiro Valera / Banca: Carlos Henrique Ribeiro Camargo / Banca: Renato Miotto Palo / Resumo: Os objetivos do presente estudo foram: a) Verificar a carga microbiana e quantificar endotoxinas presentes nos canais radiculares de dentes com infecção endodôntica primária; b) Comparar a efetividade antibacteriana e sobre endotoxinas do preparo biomecânico com dois métodos de irrigação final: com ou sem irrigação ultrassônica passiva; c) Correlacionar sinais e sintomas com a microbiota presente e complexos bacterianos; d) Relacionar níveis de endotoxinas e carga microbiana com sinais e sintomas clinicos. Foram selecionados para o estudo 20 dentes uniradiculares, que apresentavam infecção endodôntica primária e lesão periapical, sendo estes submetidos a TCFC. Os canais foram preparados com sistema reciprocante e irrigação com NaOCl 2.5%, seguido de dois protocolos de irrigação final: com e sem uso de ultrassom. Todos os canais foram preenchidos com MIC com hidróxido de cálcio + soro fisiológico e após 14 dias foram obturados com cones de guta-percha e cimento AH Plus. Foram realizadas coletas do conteúdo do canal, logo após a abertura coronária (1ª Coleta); após PBM (2ª Coleta) e após limpeza final dos canais com NaOCl seguido de EDTA por 5 min (grupo sem PUI); ou irrigação com NaOCl + PUI e EDTA + PUI (3ª Coleta) (grupo com PUI) . Foram avaliados sinais/sintomas clínicos previo ao tratamento.O conteúdo das coletas foi analisado a partir de sondas de DNA pelo método de hibridização DNA-DNA checkerboard e foi realizado teste de avaliação da atividade antimicrobiana por cultu... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract : the objetive of this study were: a) to check the microbial load and to quantify endotoxin present in the root canals of teeth with primary endodontic infection; b) to compare the effectiveness of bacteria and endotoxin reduction of the biomechanical preparation with final irrigation methods: with or without passive ultrasonic irrigation (PUI); c) to correlate signs and symptoms with the present microbiota and bacterial complexes; d) to relate endotoxin and microbial load levels with signs and symptoms before biomechanical preparation. Twenty single-root teeth were selected for the study, presenting primary endodontic infections and periapical lesion, which underwent CBCT. The canals were prepared with reciprocating system and irrigation with 2.5% NaOCl, followed by two final irrigation protocols: with and without ultrasound. All canals were filled with MIC with calcium hydroxide + saline and after 14 days were filled with gutta percha and AH Plus. Samples from the content of canal were harvested, after coronal opening (1st Sample); after PBM (2nd Sample) and after final cleaning of the canals with NaOCl followed by EDTA for 5 min (group without PUI); or irrigation with NaOCl + PUI and EDTA + PUI (3rd Sample) (group with PUI). The contents of the samples were analyzed from DNA probes by the DNA-DNA checkerboard hybridization method and a test was performed to evaluate the antimicrobial activity by microbiological culture. In addition, quantification of endotoxins by Limulus Amebocyte Lysate (LAL) was performed. The canal volumetry was assessed through the CBCT using Nemotec® software. The results were submitted to statistical analysis by Mann Whitney and repeated measures two-way ANOVA (5%). Value of p <0.05 was considered statistically significant. There was an association between pain at percussion and main orange and peripheral orange complexes...(Resumo completo, clicar acesso eletrônico abaixo) / Mestre