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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.
71

Untersuchungen zur Hochrateabscheidung harter DLC-Schichten

Graupner, Karola 11 January 2005 (has links) (PDF)
Amorphous, hydrogenated carbon films (a-C:H) have been prepared in a PECVD device from methane and ethine as the source gases.The aim was to deposit films at high growth rates while keeping high hardness (25 ± 3 GPa). Hardness, hydrogen content and surface roughness were investigated dependent on the process conditions. Further investigation showed, that the mechanical properties of the a-C:H films are determined by the energy of the ions and the ratio between the film forming ion and the film forming neutral fluxes. On the basis of the collected data the optimal deposition conditions were determined and suggestions for further improvement of the deposition were made. / Amorphe, wasserstoffhaltige Kohlenstoffschichten (a-C:H) wurden mittels PECVD-Verfahren abgeschieden, wobei Methan und Ethin als Quellgase verwendet wurde. Ziel war dabei die Abscheidung der Schichten mit hohen Aufwachsraten unter Beibehaltung hoher Härten (25 ± 3 GPa). Härte, Wasserstoffgehalt und Oberflächenrauhigkeit der Schichten wurden in Abhängigkeit von den Prozeßbedingungen untersucht. Weitere Untersuchungen zeigten, daß die mechanischen Eigenschaften der a-C:H Schichten von der Energie der Ionen und dem Verhältnis der schichtbildenden Ionen- und Neutralteilchenflüsse bestimmt werden. Auf der Grundlage der gewonnenen Daten können die optimalen Abscheidebedingungen festgelegt, und Vorschläge zur weiteren Verbesserung der Schichtabscheidung gemacht werden.
72

Surface Properties of Hard Fluorinated Amorphous Carbon Films Deposited by Pulsed-DC Discharges

Rubio Roy, Miguel 26 February 2010 (has links)
New Generation Lithographic (NGL) techniques have been recently investigated in order to overcome the limitations of the long-used UV lithography. Several techniques have been proposed during the last decades, but the continued improvement of UV lithography rendered them useful only for a limited number of applications. More recently, nanoimprint lithography (NIL), invented in the nineties, has been considered as the new NGL due to its extreme simplicity and high resolution. Thermal NIL consists in the deformation of a thermoplastic under pressure and temperature by a nanostructured mold, while UV-NIL consists in the polymerization by UV light of a monomer at room temperature and under a lower pressure than Thermal NIL. One of the main problems of this technique is mold-polymer separation after the process. This problem is especially important for UV-NIL, because the working treatments for Thermal NIL degrade with UV light. In order to assess this problem, thin diamond-like amorphous carbon films (DLC) have been proposed as an alternative to existing treatments for their low chemical reactivity and the possibility to incorporate other chemical elements to further reduce their surface energy. Amorphous carbon exists in different forms, depending on how it is grown. Its mechanical properties range from polymer or graphite-like to almost as resistant as diamond. Besides the excellent mechanical properties of DLC (high hardness, elasticity and wear resistance, and low dry friction), amorphous carbon has also been found useful in applications requiring inert and/or biocompatible surfaces. The project DPI2007-61349 of the Science and Innovation Department of Spain, named “Amorphous carbon molds for micro and nanoimprint of polymeric surfaces”, aims to study the effect of the incorporation of different elements in DLC films for the improvement of NIL molds. This thesis has focused on a series of objectives of this project: - Design and construction of a very high vacuum reactor for deposition processes and ionic etch - Incorporation of fluorine to amorphous carbon films and subseqüent characterization by different surface, mechanical and tribological techniques, as well as spectroscopy for the characterization of the plasma used for the process. - Set up and optimization of a deep ion etch technique with ion beam for the production of molds. - The use of different lithographic techniques oriented to the production in large scale of nanometric patterns. - The exploration of mold coating to increase its durability and antisticking properties in nanoimprint processes. The incorporation of fluorine in DLC films has demonstrated to be useful in the improvement of the properties of NIL molds, because it avoids the use of the current surface treatments, which in addition to being less durable, can react with polymers in presence of UV light. In this thesis, the influence of fluorine incorporation in the films has been studied. Fluorinated amorphous carbon films have been deposited by pulsed-DC plasma enhanced chemical vapor deposition, by progressively replacing methane by trifluoromethane. The experimental device used for deposition has been designed and built to allow a number of multiple processes in the same reactor. The results of the study demonstrate the feasibility of this technique, of easy industrial implementation, for the deposition of this type of coatings. The characterization of both the active species in the plasma and the groups incorporated into the deposited films has helped to understand the process of fluorine incorporation, as well as the change in the surface properties that it entails. / La dificultad de extender el uso de la litografía de luz ultravioleta (UV) a los cada vez más estrictos requisitos de resolución, llevaron desde hace ya un par de décadas, a plantearse la necesidad de buscar técnicas litográficas llamadas de “Nueva Generación” (NGL) que las superasen. Son diversas las técnicas se han ido proponiendo durante estos años, pero la mejora de la litografía UV las ha ido relegando fuera del ámbito industrial. Más recientemente, la litografía por nanoestampación (NIL), ha tomado fuerza como la nueva NGL por su extrema sencillez y por su demostrada elevada resolución. La NIL térmica (T-NIL) consiste en la deformación de un termoplástico bajo presión y temperatura por un molde con estructuras nanométricas, mientras que la NIL por UV (UV-NIL) consiste en la polimerización de un monómero a temperatura ambiente con menor presión ejercida por un molde transparente al UV. Uno de los principales problemas de esta técnica es la separación de molde y polímero, una vez finalizado el proceso. Como alternativa a los tratamientos existentes, se han propuesto los recubrimientos de carbono amorfo tipo diamante (DLC) por su baja reactividad química, elevada dureza y posibilidad de incorporación de otros elementos químicos a fin de reducir su energía superficial. El proyecto del Ministerio de Ciencia e Innovación DPI2007-61349, “Moldes de carbono amorfo para micro y nanograbado de superficies poliméricas”, en el cuál se ha enmarcado esta tesis, pretende estudiar los efectos de la incorporación de diferentes elementos en capas de DLC para la mejora de los moldes de NIL. La incorporación de flúor en capas de DLC ha demostrado recientemente ser útil en la mejora de las propiedades de los moldes de NIL, porque evita el uso de los actuales tratamientos superficiales (por ejemplo siloxanos), los cuales, además de ser menos duraderos, pueden reaccionar con los polímeros en presencia de luz UV. Así, en esta tesis se ha estudiado la influencia de la incorporación de flúor a capas de DLC en la composición y en las propiedades de superfície obtenidas.
73

Percepção da equipe multiprofissional sobre o cuidado humanizado nas unidades de terapia intensiva de um hospital escola

Evangelista, Viviane Canhizares [UNESP] 28 February 2013 (has links) (PDF)
Made available in DSpace on 2014-08-13T14:50:45Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-02-28Bitstream added on 2014-08-13T18:00:45Z : No. of bitstreams: 1 000754108.pdf: 394259 bytes, checksum: 372ab7b92edcfbd2411ebf12ca907775 (MD5) / A experiência adquirida em contextos de Unidades de Terapia Intensiva (UTIs) desperta questionamentos sobre temas relacionados a ações humanizadas. As UTIs são locais destinados a cuidados críticos, assistidos por uma equipe multiprofissional qualificada, sob as melhores condições possíveis. A responsabilidade da equipe se estende para além das intervenções tecnológicas e farmacológicas focalizadas no paciente, inclui avaliação das necessidades dos familiares, grau de satisfação destes sobre os cuidados realizados, além da preservação da integridade do paciente, acreditando-se que a humanização da assistência auxilia a diminuir os traumas do paciente, da família e norteia os profissionais envolvidos para uma assistência menos mecanizada. O objetivo deste estudo foi compreender o significado do cuidado humanizado para profissionais das Unidades de Terapia Intensiva, a partir da vivência em equipe multiprofissional de um hospital escola. Foi um estudo de campo, exploratório e descritivo, com abordagem qualitativa; utilizou como base teórica a Política Nacional de Humanização (PNH) e metodológica, a Análise de Conteúdo. Os sujeitos foram 24 profissionais da equipe multiprofissional (enfermeiros, fisioterapeutas, psicólogos, nutricionistas, médicos e assistente social) atuantes em UTIs Adulto. A coleta de dados se deu por meio de entrevista semiestruturada, tendo como foco principal a questão norteadora: Como é a sua experiência no desenvolvimento do cuidar humanizado junto a pacientes internados na UTI, atuando em equipe multiprofissional?. Nos resultados deste estudo, os 24 profissionais da equipe multiprofissional, com idade média de 35 anos, sendo a maioria do sexo feminino e religião católica. O tempo médio de formação destes profissionais é de 10 anos, sendo 6 anos o tempo de atuação em unidade crítica e, 15 dos entrevistados, atuam em um único emprego. Na análise das entrevistas, emergiram ... / The experience gained in the context of Intensive Care Units (ICUs) awakens questions to topics related to humanized actions. ICUs are places for critical care, assisted by a skilled multidisciplinary team, under the best possible conditions. The team's responsibility extends beyond the technological and pharmacological interventions focused on the patient. It includes assessing the patient’s family needs, their degree of satisfaction on the offered care, preserving the integrity of the patient, believing that the humanization of care helps reduce the patient’s and family’s trauma, and guides the professionals involved to a less mechanized assistance. The aim of this study was to understand the meaning of humanized care among professionals in the Intensive Care Units of a teaching hospital, from the working experience of a multidisciplinary team. This is a field study, with an exploratory and descriptive qualitative approach; the National Humanization Policy (NHP) was used as theoretical framework, and the Content Analysis as methodological framework. The subjects were 24 multidisciplinary team professionals (nurses, physiotherapists, psychologists, nutritionists, doctors and social workers) working in Adult ICUs. Data collection occurred through semi-structured interviews, focusing on the main question: What is your experience in the development of humanized care with patients admitted to an ICU, working in multidisciplinary team '. In this study, the multidisciplinary team of 24 professionals had average age of 35 years, the majority being female and Catholic. These professionals had an average of 10 years from graduation, 6 years of working in the ICU, and 15 professionals worked in a single job. In the interviews, themes and units of meaning emerged. Theme 1 - Multidisciplinary Team and what facilitates humanized care: focusing in the practice of individualized care; understanding and contextualizing the ...
74

Selektivní růst kovových materiálů. / Selective growth of metallic materials.

Šimíková, Michaela January 2009 (has links)
The diploma thesis deals with selective growth of cobalt thin films on lattices created by focused ion beam on Si(111) substrates with thin film of silicon dioxide. Further, the growth and morphology of iron thin films growing on Si/SiO2 substrate without modification was studied. In the last part, thin film of a-C:H, influence of preparation parameters on their growth and ratio of sp2 and sp3 bonds, was investigated. For analysis of those films XPS, AFM, and SEM metods were used.
75

Technology for the Advancement of Die Casting Tooling

Corey Mitchell Vian (11160009) 21 July 2021 (has links)
<p>High pressure die casting is an industrial metal casting process used to manufacture goods for use in many aspects of society. Within this manufacturing process, the tooling is subjected to chemical attack from molten aluminum while also being responsible for heat removal during solidification. The purpose of this study is to develop and test materials that allow the tools to better withstand the chemical attack, and to develop design rules to guide the use of additive manufacturing for improving the heat exchange function of by way of conformal cooling.</p> <p> </p> <p>Within the material studies, a gooseneck with a niobium lining was developed to allow the successful implementation of hot chamber aluminum die casting. In addition, a manufacturing plan is described that will allow the niobium gooseneck design to be easily sourced by die casting companies. The material studies also included dunk testing of several coatings, including a plasma assisted chemical vapor deposition silicon doped diamond like carbon (PACVD Si-DLC). The Si-DLC coating performed the best in the dunk testing as compared to bare and nitrocarburized tool steel, and a number of other coating architectures.</p> <p> </p> Within the study of additively manufactured conformal cooling design, a finite difference model is developed that allows a simulated experiment that produced a number of useful equations that guide the design of die casting tooling. During the development of the models, it was discovered that little is known regarding the friction factors of additively manufactured steel pipes, so a factorial experiment was employed to empirically determine said friction factors. Charts allowing design engineers to quickly determine pressure drops and heat transfer coefficients of conformal cooling designs was produced as well.<br>
76

DDM: Study of deer detection and movement using deep learning techniques

Siddique, Md Jawad 01 December 2021 (has links)
Deer Vehicle Collisions (DVCs) are a global problem that is not only resulting in seriousinjuries to humans but also results in loss of human and deer lives. Deer are more active and less attentive during the mating and hunting seasons. Roadside deer activity such as feeding and strolling along the roadside has a significant correlation with DVCs. To mitigate DVCs, several strategies were used that include vegetation management, fences, underpasses and overpasses, population reduction, warning signs and animal detection systems (ADS). These strategies vary in their efficacy. These strategies may help to reduce DVCs. However, they are not always easily feasible due to false alarms, high cost, unsuitable terrain, land ownership, and other factors. Thus, DVCs are increasing due to the increase in number of vehicles and the absence of intelligent highway safety and alert systems. Detecting deer in real-time on our roads is a challenging problem. Thus, this research work proposed a deer detection and movement DDM technique to automate DVCs mitigation system. The DDM combines computer vision, artificial intelligent methods with deep learning techniques. DDM includes two main deep learning algorithms 1)onestage deep learning algorithm based on Yolov5 that generates a detection model(DM) to detect deer and 2) deep learning algorithm developed by python toolkit DeepLabCut to generate movement model(MM) for detecting the movement of the deer. The proposed method can detect deer with 99.7% precision and succeeds to ascertain if the deer is moving or static with an inference speed of 0.29s. The proposed method can detect deer with 99.7% precision and using DeepLabCut toolkit on the detected deer we can ascertain if the deer is moving or static with an inference speed of 0.29s.
77

Investigating the Rapid Clearance of Oscillating Transcripts during Vertebrate Segmentation

Tietz, Kiel Thomas 20 June 2019 (has links)
No description available.
78

Characterization of Diamond Like Carbon Thin Films Fabricated by Unbalanced Magnetron Sputtering under Ultra-High Vacuum Conditions

Cooper, Kevin W. 24 September 2013 (has links)
No description available.
79

Estudo dos parâmetros de deposição de filmes finos de carbono amorfo hidrogenado obtidos pelo processo PECVD em embalagens de PET pós-consumo reciclado

Oliveira, Eder Costa January 2010 (has links)
Orientadora: Sandra Andrea Cruz. / Dissertação (mestrado) - Universidade Federal do ABC. Programa de Pós Graduação em Nanociências e Materiais Avançados, 2010.
80

Surfaces Designed for High and Low Friction / Ytor utformade för hög och låg friktion

Pettersson, Ulrika January 2005 (has links)
<p>This thesis comprises tribological studies of extremely well-defined surfaces of different designs. Both low-friction and high-friction surfaces were manufactured and experimentally evaluated.</p><p>In the low-friction studies, lithography and anisotropic etching of silicon was first used as a texturing technique. The textured surfaces were subsequently PVD coated with TiN or DLC to achieve tribologically relevant interfaces. The results showed that under starved lubricated conditions, fine surface textures lowered the coefficient of friction and the wear rate. It was shown that also the orientation of the texture is of major importance for the lubricating function.</p><p>Further, a novel embossing technique was developed, permitting texturing of steel and other materials. A micro mechanically designed diamond tool was used to emboss steel surfaces. The roller/piston contact from a hydraulic motor was simulated and introduction of an embossed texture on the piston decreased the level and the fluctuation of the friction. The effect of the texture was here similar to the effect of an additional polish step. However, in general it is not an easy task to substantially improve a boundary lubricated contact by introducing a texture. </p><p>Studies of high friction surfaces were performed on micro mechanically designed diamond surfaces equipped with sharp pyramids or ridges. Just as theory predicts, the coefficient of friction was dependent on the shape of the ploughing bodies, but not on the counter material or the load. The tested surfaces resulted in static coefficients of friction between 1.1 and 1.6, depending on surface design and orientation. These are extremely high values, and therefore very interesting for practical applications requiring a high static friction.</p><p>Conclusively, the present thesis shows that it is possible to design and produce surfaces both for improved lubrication in sliding contact and for substantially improved high friction performance in static contacts.</p>

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