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Growth Monitoring of Ultrathin Copper and Copper Oxide Films Deposited by Atomic Layer Deposition / Untersuchungen zum Wachstum ultradünner Kupfer- und Kupferoxid Schichten mittels AtomlagenabscheidungDhakal, Dileep 25 October 2017 (has links) (PDF)
Atomic layer deposition (ALD) of copper films is getting enormous interest. Ultrathin Cu films are applied as the seed layer for electrochemical deposition (ECD) of copper in interconnect circuits and as the non-magnetic material for the realization of giant magnetoresistance (GMR) sensors. Particularly, Co/Cu multi-layered structures require sub 4.0 nm copper film thickness for obtaining strong GMR effects. The physical vapor deposition process for the deposition of the copper seed layers are prone to non-conformal coating and poor step coverage on side-walls and bottoms of trenches and vias, and presence of overhanging structures. This may cause failure of interconnections due to formation of voids after copper ECD. ALD is the most suitable technology for the deposition of conformal seed layers for the subsequent ECD in very high aspect ratio structures, also for the technology nodes below 20 nm. Surface chemistry during the ALD of oxides is quite well studied. However, surface chemistry during the ALD of pure metal is rather immature. This knowledge is necessary to optimize the process parameters, synthesize better precursors systems, and enhance the knowledge of existing metal ALD processes. The major goal of this work is to understand the surface chemistry of the used precursor and study the growth of ultrathin copper films using in-situ X-ray photoelectron spectroscopy (XPS). Copper films are deposited by ALD using the precursor mixture consisting of 99 mol% [(nBu3P)2Cu(acac)], as copper precursor and 1 mol% of Ru(η5 C7H11)(η5 C5H4SiMe3), as ruthenium precursor. The purpose in having catalytic amount of ruthenium precursor is to obtain the Ru doped Cu2O layers for subsequent reduction with formic acid at temperatures below 150 °C on arbitrary substrates. Two different approaches for the growth of ultrathin copper films have been studied in this dissertation. In the first approach, direct thermal ALD of copper has been studied by using H2 as co-reactant on Co as catalytic substrate. In the second approach, Ru-doped Cu2O is deposited by ALD using wet-O2 as co-reactant on SiO2 as non-catalytic substrate. The Ru-doped Cu2O is successfully reduced by using either formic acid or carbon-monoxide on SiO2. / Atomlagenabscheidung (ALD) von Kupfer steht im Fokus der ALD Gemeinschaft. Ultradünne Kupferschichten können als Keimschicht für die elektrochemische Abscheidung (ECD) von Kupfer in der Verbindungstechnologie eingesetzt werden. Sie können ebenfalls für Sensoren, welche auf den Effekt des Riesenmagnetowiderstandes (GMR) basieren, als nicht-ferromagnetische Zwischenschicht verwendet werden. Insbesondere Multischichtstrukturen aus ferromagnetische Kobalt und Kupfer erfordern Schichtdicken von weniger als 4,0 nm, um einen starken GMR-Effekt zu gewährleisten. Das derzeit verwendete physikalische Dampfabscheidungsverfahren für ultradünne Kupferschichten, ist besonders anfällig für eine nicht-konforme Abscheidung an den Seitenwänden und Böden von Strukturen mit hohem Aspektverhältnis. Des Weiteren kann es zur Bildung von Löchern und überhängenden Strukturen kommen, welche bei der anschließenden Kupfer ECD zu Kontaktlücken (Voids) führen können. Für die Abscheidung einer Kupfer-Keimschicht ist die ALD besonders gut geeignet, da sie es ermöglicht, ultradünne konforme Schichten auf strukturierten Oberflächen mit hohem Aspektverhältnis abzuscheiden. Dies macht sie zu einer der Schlüsseltechnologien für Struckturgrößen unter 20 nm. Im Gegensatz zur Oberflächenchemie rein metallischer ALD sind die Oberflächenreaktionen für oxidische ALD Schichten sehr gut untersucht. Die Kenntnis der Oberflächenchemie während eines ALD Prozesses ist essenziel für die Bestimmung von wichtigen Prozessparametern als auch für die Verbesserung der Präkursorsynthese ansich. Diese Arbeit beschäftigt sich mit der Untersuchung der Oberflächenchemie und Charakterisierung des Wachstums von ultradünnen Metall-Cu-Schichten mittels In-situ XPS, welche eines indirekten (Oxid) bzw. direkten Metall-ALD Prozesses abgeschieden werden, wobei die Kupfer-Oxidschichten im Anschluss einem Reduktionsprozess unterworfen werden. Hierfür wird eine Präkursormischung bestehend aus 99 mol% [(nBu3P)2Cu(acac)] und 1 mol% [Ru(η5 C7H11)(η5-C5H4SiMe3)] verwendet. Die katalytische Menge an Ru, welche in der entstehenden Cu2O Schicht verbleibt, erhöht den Effekt der Reduktion der Cu2O Schicht auf beliebigen Substraten mit Ameinsäure bei Wafertemperaturen unter 150 °C. In einem ersten Schritt wird ein direkter thermisches Kupfer ALD-Prozess, unter Verwendung von molekularem Wasserstoff als Coreaktant, auf einem Kobalt-Substrat untersucht. In einem zweiten Schritt wird ein indirekter thermischer Cu2O-ALD-Prozess, unter gleichzeitiger Verwendung von Sauerstoff und Wasserdampf als Coreaktant, mit anschließender Reduktion durch Ameinsäure oder Kohlenstoffmonoxid zu Kupfer auf den gleichen Substraten betrachtet. Die vorliegende Arbeit beschreibt das Wachstum von ultradünnen und kontinuierlichen Kupfer-Schichten mittels thermischer ALD auf inerten- SiO2 und reaktiven Kobalt-Substraten.
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Growth Monitoring of Ultrathin Copper and Copper Oxide Films Deposited by Atomic Layer DepositionDhakal, Dileep 16 December 2016 (has links)
Atomic layer deposition (ALD) of copper films is getting enormous interest. Ultrathin Cu films are applied as the seed layer for electrochemical deposition (ECD) of copper in interconnect circuits and as the non-magnetic material for the realization of giant magnetoresistance (GMR) sensors. Particularly, Co/Cu multi-layered structures require sub 4.0 nm copper film thickness for obtaining strong GMR effects. The physical vapor deposition process for the deposition of the copper seed layers are prone to non-conformal coating and poor step coverage on side-walls and bottoms of trenches and vias, and presence of overhanging structures. This may cause failure of interconnections due to formation of voids after copper ECD. ALD is the most suitable technology for the deposition of conformal seed layers for the subsequent ECD in very high aspect ratio structures, also for the technology nodes below 20 nm. Surface chemistry during the ALD of oxides is quite well studied. However, surface chemistry during the ALD of pure metal is rather immature. This knowledge is necessary to optimize the process parameters, synthesize better precursors systems, and enhance the knowledge of existing metal ALD processes. The major goal of this work is to understand the surface chemistry of the used precursor and study the growth of ultrathin copper films using in-situ X-ray photoelectron spectroscopy (XPS). Copper films are deposited by ALD using the precursor mixture consisting of 99 mol% [(nBu3P)2Cu(acac)], as copper precursor and 1 mol% of Ru(η5 C7H11)(η5 C5H4SiMe3), as ruthenium precursor. The purpose in having catalytic amount of ruthenium precursor is to obtain the Ru doped Cu2O layers for subsequent reduction with formic acid at temperatures below 150 °C on arbitrary substrates. Two different approaches for the growth of ultrathin copper films have been studied in this dissertation. In the first approach, direct thermal ALD of copper has been studied by using H2 as co-reactant on Co as catalytic substrate. In the second approach, Ru-doped Cu2O is deposited by ALD using wet-O2 as co-reactant on SiO2 as non-catalytic substrate. The Ru-doped Cu2O is successfully reduced by using either formic acid or carbon-monoxide on SiO2. / Atomlagenabscheidung (ALD) von Kupfer steht im Fokus der ALD Gemeinschaft. Ultradünne Kupferschichten können als Keimschicht für die elektrochemische Abscheidung (ECD) von Kupfer in der Verbindungstechnologie eingesetzt werden. Sie können ebenfalls für Sensoren, welche auf den Effekt des Riesenmagnetowiderstandes (GMR) basieren, als nicht-ferromagnetische Zwischenschicht verwendet werden. Insbesondere Multischichtstrukturen aus ferromagnetische Kobalt und Kupfer erfordern Schichtdicken von weniger als 4,0 nm, um einen starken GMR-Effekt zu gewährleisten. Das derzeit verwendete physikalische Dampfabscheidungsverfahren für ultradünne Kupferschichten, ist besonders anfällig für eine nicht-konforme Abscheidung an den Seitenwänden und Böden von Strukturen mit hohem Aspektverhältnis. Des Weiteren kann es zur Bildung von Löchern und überhängenden Strukturen kommen, welche bei der anschließenden Kupfer ECD zu Kontaktlücken (Voids) führen können. Für die Abscheidung einer Kupfer-Keimschicht ist die ALD besonders gut geeignet, da sie es ermöglicht, ultradünne konforme Schichten auf strukturierten Oberflächen mit hohem Aspektverhältnis abzuscheiden. Dies macht sie zu einer der Schlüsseltechnologien für Struckturgrößen unter 20 nm. Im Gegensatz zur Oberflächenchemie rein metallischer ALD sind die Oberflächenreaktionen für oxidische ALD Schichten sehr gut untersucht. Die Kenntnis der Oberflächenchemie während eines ALD Prozesses ist essenziel für die Bestimmung von wichtigen Prozessparametern als auch für die Verbesserung der Präkursorsynthese ansich. Diese Arbeit beschäftigt sich mit der Untersuchung der Oberflächenchemie und Charakterisierung des Wachstums von ultradünnen Metall-Cu-Schichten mittels In-situ XPS, welche eines indirekten (Oxid) bzw. direkten Metall-ALD Prozesses abgeschieden werden, wobei die Kupfer-Oxidschichten im Anschluss einem Reduktionsprozess unterworfen werden. Hierfür wird eine Präkursormischung bestehend aus 99 mol% [(nBu3P)2Cu(acac)] und 1 mol% [Ru(η5 C7H11)(η5-C5H4SiMe3)] verwendet. Die katalytische Menge an Ru, welche in der entstehenden Cu2O Schicht verbleibt, erhöht den Effekt der Reduktion der Cu2O Schicht auf beliebigen Substraten mit Ameinsäure bei Wafertemperaturen unter 150 °C. In einem ersten Schritt wird ein direkter thermisches Kupfer ALD-Prozess, unter Verwendung von molekularem Wasserstoff als Coreaktant, auf einem Kobalt-Substrat untersucht. In einem zweiten Schritt wird ein indirekter thermischer Cu2O-ALD-Prozess, unter gleichzeitiger Verwendung von Sauerstoff und Wasserdampf als Coreaktant, mit anschließender Reduktion durch Ameinsäure oder Kohlenstoffmonoxid zu Kupfer auf den gleichen Substraten betrachtet. Die vorliegende Arbeit beschreibt das Wachstum von ultradünnen und kontinuierlichen Kupfer-Schichten mittels thermischer ALD auf inerten- SiO2 und reaktiven Kobalt-Substraten.
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Atomic Layer Deposition and High Sensitivity-Low Energy Ion Scattering for the Determination of the Surface Silanol Density on Glass and Unsupervised Exploratory Data Analysis with Summary Statistics and Other MethodsGholian Avval, Tahereh 18 July 2022 (has links)
With the increasing importance of hand-held devices with touch displays, the need for flat panel displays (FPDs) will likely increase in the future. Glass is the most important substrate for FPD manufacturing, where both its bulk and surface properties are critical for its performance. Many properties of the glass used in FPDs are controlled by its surface chemistry. Surface hydroxyls are the most important functional groups on a glass surface, which control processes that occurs on oxide surfaces, including wetting, adhesion, electrostatic charging and discharge, and the rate of contamination. In this dissertation, I present a new approach for determining surface silanol densities on planar surfaces. This methodology consists of tagging surface silanols using atomic layer deposition (ALD) followed by low energy ion scattering (LEIS) analysis of the tags. The LEIS signal is limited to the outermost atomic layer, i.e., LEIS is an extremely surface sensitive technique. Quantification in LEIS is straightforward in the presence of suitable reference materials. An essential part of any LEIS measurement is the preparation and characterization of the sample and appropriate reference materials that best represent the samples. My tag-and-count method was applied to chemically and thermally treated fused silica. In this work, I determined the silanol density of a fully hydroxylated fused silica surface to be 4.67 OH/nm2. This value agrees with the literature value for high surface area silica powder. My methodology should be important in future glass studies. Surface Science Spectra (SSS) is an important, peer-reviewed database of spectra from surfaces. Recently, SSS has been expanding to accept spectra from new surface techniques. I created the first SSS submission form for LEIS spectra (see appendix 5), and used it to create the first SSS LEIS paper (on CaF2 and Au reference materials, see chapter 3). I also show LEIS reference spectra for ZnO, and copper in the appendix 1. The rest of my dissertation focuses on my chemometrics/informatics and data analysis work. For example, I showed the performance and capabilities of a series of summary statistics as new tools for unsupervised exploratory data analysis (EDA) (see chapter 4). Unsupervised EDA is often the first step in understanding complex data sets because it can group, and even classify, samples according to their spectral similarities and differences. Pattern recognition entropy (PRE) and other summary statistics are direct methods for analyzing data - they are not factor-based approaches like principal component analysis (PCA) or multivariate curve resolution (MCR). I show that, in general, PRE outperforms the other summary statistics, especially in image analysis, although I recommend a suite of summary statistics be used in exploring complex data sets. In addition, I introduce the concept of divided spectrum-PRE (DS-PRE) as a new EDA method and use it to analyze multiple data sets. DS-PRE increases the discrimination power of PRE. I have also prepared a guide that discusses the vital aspects and considerations for chemometrics/informatics analyses of XPS data along with specific EDA tools that can be used to probe XPS data sets, including PRE, PCA, MCR, and cluster analysis (see chapter 5). I emphasize the importance of an initial evaluation/plotting of raw data, data preprocessing, returning to the original data after a chemometrics/informatics analysis, and determining the number of abstract factors to keep in an analysis, including reconstructing the data using PCA. In my thesis, I also show the analysis of commercial automotive lubricant oils (ALOs) with various chemometrics techniques (see chapter 6). Using these methods, the ALO samples were readily differentiated according to their American Petroleum Institute (API) classification and base oil types: mineral, semi-synthetic, and synthetic.
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A captação de recursos de empreendimentos socioculturais no Estado de São Paulo / The acquisiton of resources for socio-cultural enterprises in the State of São PauloSaroute, Renata Roquetti 12 June 2018 (has links)
O presente trabalho visa compreender teórica e empiricamente como empreendimentos socioculturais, com sedes e iniciativas no Estado de São Paulo, captam os seus recursos financeiros, sob três aspectos principais: estratégia, estrutura e fontes de captação de recurso. Entende-se como empreendimentos socioculturais, aqui nomeados, as iniciativas que utilizam a cultura e a arte como ferramentas de transformação social, objetivando o acesso à cultura artística, bem como à formação educacional, por via das mesmas, de indivíduos que não poderiam vivenciá-las devido às suas condições sociodemográficas, socioeconômicas e/ou físico-intelectuais. Para isto, foram analisados seis empreendimentos socioculturais, são eles: BuZum Produções Artísticas; ImageMagica Organização Cultural da Sociedade Civil; Doutores da Alegria - arte na promoção da saúde, na formação e no desenvolvimento social; Ibirajá Produções Culturais; Companhia Pia Fraus de Teatro e Cia Vagalum Tum Tum de Teatro Infantil - todos ativos no estado de São Paulo. A pesquisa foi de natureza aplicada, exploratória e qualitativa, utilizando-se a estratégia de estudos de casos múltiplos. Com coleta de dados secundários, através de análise documental e de arquivos somada à coleta de dados primários, através de entrevista estrutura com questionário de perguntas abertas. Os resultados consolidados evidenciaram que não é possível traçar um modelo único para a captação de recursos de empreendimentos socioculturais, mas é possível traçar estratégias e estruturas, que podem ser replicadas, afim de se ter sucesso na obtenção de recursos, nas mais variadas fontes disponíveis. / This work aimed to understand theoretically and empirically as socio-cultural enterprises, with headquarters and initiatives located in the State of São Paulo, are seeking their financial resources. It is understood as socio-cultural enterprises, here named, the initiatives that uses culture and art as a tool of social transformation, objectifying the access to the artistic culture, as well as to the educational formation, aiming to attend individuals would not experience it, due to their socio-demographic, socioeconomic and/or physical-intellectual conditions. In this regard, six socio-cultural projects were analyzed; which are: BuZum Artistic Productions, ImageMagica civil society organization; Doctors of Joy; Ibirajá Cultural Production; Pia Fraus\' Company Theatre and Vagalum Tum Tum Children\'s Theatre Company - all assets in the State of São Paulo. The research was applied, exploratory and qualitative, using the strategy of multiple case studies. With secondary data collection, through documentary and file analysis added to the primary data collection, by structural interview with questionnaire with open questions. The consolidated results showed that it is not possible to trace a single model for the acquisition of resource for socio-cultural enterprises, but it is possible to replay strategies and structures to obtain success in the acquisition of resources.
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Desenvolvimento de esquema upwind para equações de conservação e implementação de modelagens URANS com aplicação em escoamentos incompressíveis / Development of a new upwind scheme for conservationlaws and implementation on URANS modelling with application on incompressible flowsCandezano, Miguel Antonio Caro 10 December 2012 (has links)
Nesta tese é apresentado um esquema novo de alta resolução upwind (denominado TDPUS-C3) para reconstrução de fluxos numéricos para leis de conservação não lineares e problemas relacionados em DFC. O esquema é baseado nos critérios de estabilidade CBC e TVD e desenvolvido utilizando condições de diferenciabilidade \'C POT. 3\'. Além disso, é realiozada a implementação da associação do esquema TDPLUS-C3 com a modelagem de turbulência RNG \'\\kappa - \\epsilon\'. O propósito é obter soluções numéricas de sistemas hiperbólicos de leis de conservação para dinâmica dos gases e equações de Navier-Stokes para escoamento incompreensível de fluidos newtonianos e não newtonianos (viscoelásticos). Fazendo o uso do esquema TDPUS-C3, a precisão global dos métodos numéricos é verificada acessando o erro em problemas teste (benchmark) 1D e 2D. Um estudo comparativo entre os resultados do esquema TDPUS-C3 e os esquemas upwind convencionais para leis de conservação hiperbólicas complexas é também realizado. A Associação das modelagens numéricas (upwinding mais RNG \'\\kappa - \\epsilon\') é , então, examinada na simulação de escoamentos turbulentos de fluidos newtonianos envolvendo superfícies livres móveis, usando a metodologia URANS. No geral, em termos do comportamento global, concordância satisfatória é observada / In this thesis, a new high-resolution upwind scheme (named TDPUS-C3) for reconstruction of numerical fluxes for nonlinear conservation laws and related CFD problems in presented. The scheme is based on CBC and TVD stability criteria and developed by employing differentiability condictions (\'C POT. 3\'). In additon, the implementation of an association of the TDPUS-C3 scheme with the RNG \'\\kappa - \\epsilon\' turbulence modelling is also performed. The purpose is to obtain numerical solutions of systems of hyperbolic conservation laws for gas dynamics and Navier-Stokes equations for incompressible flow of Newtonian and non-Newtonian (viscoelstic) fluids. By using the TDPUS-C3 scheme, the global accuracy of the numerical methods is verified by assessing the error on 1D and 2D benchmark test cases. A comparative study between the TDPUS-C3 scheme and convectional upwind schemes to solve standard and complex hyperbolic conservation laws is also accomplished. The association of the numerical modelling (upwinding plus RNG \'\\kappa - epsilon\') is then examined in the simulation of turbulent Newtonian fluid flows involving moving free surfaces, by using URANS methodology. Overall, satisfactory agreement is found in terms of the overall behaviour
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Lateral stability of ultra-high performance fiber-reinforced concrete beams with emphasis in transitory phases / Instabilidade lateral de vigas de concreto de ultra-alto desempenho reforçado com fibras com ênfase em fases transitóriasKrahl, Pablo Augusto 04 July 2018 (has links)
The development of advanced fiber reinforced cement-based materials to provide higher strength, ductility, and durability, as ultra-high performance fiber-reinforced concrete (UHPFRC), enables the design of precast beams with thin sections and reduced self-weight to meet the required flexural performance. However, such slender elements when subjected to transitory phases, and possibly also in permanent stages, are prone to instability failure. So, the present study aims to provide experimental data and analytical solution for UHPFRC beams during the lifting phase, and studies about the other stages. This type of test is rare and was not reported for UHPFRC beams. For testing, the beams were lifted by inclined cables and subjected to a transversal load applied at midspan to induce lateral instability. The displacements of the beams were monitored with total station equipment. Also, a new analytical solution was proposed to predict the failure load of lifted beams and closed-form analytical solutions to predict the rollover load of beams supported by bearing pads and subjected to different loading conditions. Furthermore, there are limited data that characterizes the constitutive behavior of this material. In this context, the present research also focused on providing such laboratory results for UHPFRC with different fiber contents. Besides, analytical models for damage evolution and stress-strain relationship are proposed and applied in numerical simulations. From the results, the UHPFRC beams failed by instability with a load capacity 3.7 times smaller than the flexural load capacity. Furthermore, the analytical solution for lifting predicted the peak load of the experiment with great accuracy. Also, the proposed equations for beams on bearing pads accurately predicted the experimental results available in the literature. The analytical and experimental rollover loads differed by 4.37% and 13.6% for the two studied cases. From material, the stiffness degradation occurred rapidly in UHPFRC under tensile loading while occurred gradually in compression. Also, fiber content influenced toughness and degradation evolution significantly over the loading cycles. Proposed equations were utilized in the Plastic-Damage model of Abaqus that predicted accurately damage growth and cyclic envelopes during all the phases of the tension, compression, and bending tests. The calibrated numerical model also predicted the experimental results with the UHPFRC beams. / O desenvolvimento de materiais avançados à base de cimento reforçado com fibra para fornecer maior resistência, ductilidade e durabilidade, como o concreto de ultra-alto desempenho reforçado com fibras (UHPFRC), permite o projeto de vigas pré-moldadas com seções esbeltas e peso próprio reduzido que atendem desempenho estrutural requerido. No entanto, esses elementos delgados quando submetidos a fases transitórias e também em serviço são propensos a falhar por instabilidade. Então, o presente estudo tem por objetivo apresentar resultados experimentais e soluções analíticas para vigas de UHPFRC durante a fase de içamento e estudos sobre as outras fases. Este tipo de teste é raro e não foi reportado para vigas de UHPFRC. Para o teste, as vigas foram levantadas por cabos inclinados e submetidas a uma carga concentrada transversal aplicada no meio do vão para induzir a instabilidade lateral. Os deslocamentos das vigas foram monitorados com estação total. Além disso, uma nova solução analítica foi proposta para prever a carga de instabilidade das vigas içadas e soluções analíticas para prever a carga de tombamento de vigas suportadas por aparelho de apoio e submetidas a diferentes condições de carregamento. Além disso, existem poucos resultados experimentais que caracterizam o comportamento constitutivo deste material. Neste contexto, a presente pesquisa também se concentrou em fornecer tais resultados experimentais para UHPFRC com diferentes teores de fibras. Além disso, modelos analíticos para evolução de dano e relação tensão-deformação são propostos e aplicados em simulações numéricas. A partir dos resultados, as vigas em içamento falharam por instabilidade com uma capacidade de carga 3,7 vezes menor que a capacidade à flexão. Além disso, a solução analítica para içamento previu carga máxima do experimento com grande precisão. As equações propostas para vigas sobre aparelhos de apoio previram com precisão os resultados experimentais disponíveis na literatura. As cargas de tombamento analíticas e experimental diferiram em 4,37% e 13,6% para os dois casos estudados. Dos resultados do material, a degradação da rigidez ocorreu de maneira rápida no UHPFRC submetido à tração enquanto ocorreu gradualmente na compressão. O teor de fibras influenciou significativamente a tenacidade e a degradação nos ciclos de carregamento. As equações propostas foram utilizadas em um modelo de Dano acoplado à plasticidade que previu com precisão a evolução do dano e as envoltórias cíclicas durante todas as fases dos testes de tração, compressão e flexão. O modelo numérico calibrado também previu os resultados experimentais das vigas de UHPFRC.
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[en] USING FINITE ELEMENT MODEL IN THE DEVELOPMENT OF CUTTING MATERIAL MODELS / [pt] UTILIZAÇÃO DO MÉTODO DOS ELEMENTOS FINITOS NO DESENVOLVIMENTO DE MODELOS DE CORTE DE MATERIALCARLOS FERNANDO COGOLLO APONTE 10 June 2019 (has links)
[pt] Entre os vários processos envolvidos na produção de petróleo e gás, o processo de perfuração tem recebido grande atenção recentemente. Pesquisas estão sendo direcionadas para este tema com o objetivo de melhorar o desempenho das brocas de perfuração. Assim, o interesse da indústria do petróleo é aumentar a taxa de penetração, reduzir o tempo de manobras, aumentar a vida útil das brocas e consequentemente reduzir gastos durante o processo de perfuração. Para alcançar estes objetivos, tradicionalmente, são empregados métodos de otimização de perfuração baseados em energia mecânica específica. Estes métodos utilizam como dados de entrada o peso sobre a broca, taxa de penetração, torque e resistência à compressão da rocha. Os métodos de otimização de perfuração ainda apresentam algumas dificuldades, tais como: relacionar energia mecânica específica com resistência à compressão simples e os métodos dependem de dados de perfuração de poços, como listados acima. Este trabalho tem como objetivo apresentar um estudo alternativo do processo de corte em rocha baseado em simulação numérica, especificamente utilizando um programa comercial de elementos finitos chamado Abaqus. A primeira parte do trabalhou consistiu no desenvolvimento de modelos de corte em metais baseado na lei de plasticidade de Johnson-Cook. A motivação na escolha destes modelos foi a grande quantidade de trabalhos encontrados na literatura que tratam do processo de usinagem em metais. Posteriormente, a segunda parte do trabalho, que trata do corte em rocha, foi conduzida. Modelos tridimensionais de ensaios de single cutter foram elaborados e simulados utilizando a lei de plasticidade de Drucker-Prager, adequada para rochas, que considera o efeito da pressão de confinamento. / [en] Among the various processes involved in producing oil and gas, the drilling process has received great attention recently. Research is being directed to this issue in order to improve the performance of drill bits. Thus, the interest of the oil industry is to increase the penetration rate, reduce the time of switching, extending the life of drills and consequently reduce spending during the drilling process. To achieve these goals are traditionally used for drilling optimization methods based on mechanical specific energy. These methods use as input the weight on the drill penetration rate, torque and compressive strength of rock. The drilling optimization methods still present some difficulties, such as mechanical specific energy relationship with compressive strength and the methods depend on data-drilling, as listed above. This dissertation aims to present a study of alternative rock cutting process based on numerical simulation, specifically using a commercial finite element program called Abaqus. The first part of the work was the development of models of metal cutting based on the plasticity law of Johnson-Cook. The motivation in choosing these models was the large number of studies in the literature dealing with the machining process in metals. Subsequently, the second part of the work, which is cut in rock, was conducted. Three-dimensional models of single cutter tests were designed and simulated using the plasticity law of Drucker-Prager, suitable for rocks, which considers the effect of confining pressure.
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Esquemas de captura de descontinuidades para equações gerais de conservação / Stock capturing scheme for general conservation equationsNarváez, Rodolfo Junior Pérez 22 February 2013 (has links)
Três esquemas de captura de descontinuidade são apresentados para simular hiperbólicos de leis de conservação e equações de Navier-Stokes incompressíveis, a saber: FDHERPUS (Five Degree Hermite Upwind Scheme); RUS (Rational Upwind Scheme); e CSPUS (Cubic Spline Polynomial Upwind Scheme). Esses esquemas são baseados nos critérios de estabilidade CBC e TVD e implementados nos contextos das metodologias diferenças finitas e volumes finitos. A precisão local dos esquemas é verificada acessando o erro e a taxa de convergência em problemas testes de referência. Um estudo comparativo entre os esquemas estudados (incluido o WENO5) e o esquema bem estabelecido de van Albada, para resolver leis de conservação lineares e não lineares, é também realizado. O esquema de convecção que fornece melhores resultados em leis de conservação hiperbólicas é então examinado na simulação de escoamentos de fluidos newtonianos com superfícies livres móveis de complexidade crescente; resultados satisfatórios têm sido observados em termos do comportamento global / Three shock capturing schemes for numerical solution of hyperbolic conservation laws and incompressible Navier-Stokes equations are presented, namely: FDHERPUS (Five Degree Hermite Polynomial Upwind Scheme); RUS (Rational Upwind Scheme); and CSPUS ( Cubic Spline Polynomial Upwind Scheme). These schemes are based on CBC and TVD stability criteria and implemented in the context of finite volume methodologies. The local observed accuracy of the schemes is verified by assessing the error and convergence rate on benchmark test cases. A comparative study between the schemes (including WENO5) and the well established van. Albada scheme to solve standard linear and nonlinear hyperbolic conservation laws is also accomplished. The scheme that has provided better results in hyperbolic conservation laws is then examined in the simulation of Newtonian moving free surface flows of increasing complexity, satisfactory agreement has been observed in terms of the overall behavior
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Ato administrativo de concessão de benefício / The administrative act for granting benefitsNascimento, Ricardo de Castro 11 May 2006 (has links)
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Previous issue date: 2006-05-11 / The objective of this dissertation is the study of the practices in the management of the social security by the public service. We begin by analyzing the main characteristics of the administrative function, from the various points of view under the perspectives of the national and foreign doctrines, and through the history of social security as a function of the state.
We describe the peculiarities of the public service of social security, the major objective of which to provide social protection according to the law is embodied and characterized legally through an administrative act. We present a list of the main characteristics of the administrative act, its elements, and the vices that can invalidate it. The study of the peculiarities of the administrative act for granting benefits is the next step.
We also analyze the demand to present an initial application for the benefit, as well as the duty-power of decision of the social security administration and the legal consequences of its inaction or silence. Finally, we examine the virtual administrative act, through which the benefits will be granted in the future / O objeto da dissertação é o exercício da função administrativa no serviço público de previdência social. Começaremos pela análise das principais características da função administrativa, nas diversas visões da doutrina nacional e estrangeira, e pelo histórico da previdência social como atividade estatal.
Discorreremos sobre as peculiaridades do serviço público de previdência social, cuja finalidade maior de outorgar a proteção social prevista em lei é materializada e individualizada, juridicamente, por meio de ato administrativo. Serão arroladas as principais características do ato administrativo, seus elementos e os vícios que podem invalidá-lo. O passo seguinte será o estudo das peculiaridades do ato administrativo de concessão de benefício.
Será também analisada a exigibilidade de requerimento prévio de concessão de benefício, assim como o dever-poder de decisão por parte da Administração previdenciária e as conseqüências jurídicas de sua inação ou silêncio. Por último, abordaremos o ato administrativo virtual, pelo qual os benefícios, no futuro, serão concedidos
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A doutrina da proteção integral da criança e do adolescente frente à lei 8069/90Mendes, Moacyr Pereira 19 June 2006 (has links)
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Previous issue date: 2006-06-19 / The main Idea of this work is to discuss the doctrine of full protection to the infant,
foreseen by the Child and Adolescent Statute. For that, we will study the main
international conventions and treaties that rule the subject, in order to fallow the
historical evolution of this new doctrine in our legal system, since the Constitution
of 1988, until the issue of the Child and Adolescent Statute.
We will analize the relevant aspects of the full protection doctrine necessities and
importance, as well as the new of the infant presented by the Statute, who is no
longer seen as an object, but as a person in a peculiar development condition.
We will discuss the new view, and the necessity of the protection doctrine,
presenting and referring to some of its aspects, which, as we shall see, are vital to
the infant development.
This way, we believe that full protection doctrine will be widely discussed, with a
perfect understanding of this new view presented by the Child and Adolescent
Statute, that, as said before, considers the infant a person in peculiar condition / A idéia central desse trabalho é falarmos sobre a doutrina da proteção integral do
menor, prevista no Estatuto da Criança e do Adolescente. Para tanto, faremos um
estudo das principais convenções e tratados internacionais que regem a matéria,
para, em seguida, trilharmos uma evolução histórica dessa nova doutrina no
nosso ordenamento jurídico, a partir da Constituição de 1988, culminando com a
edição do Estatuto da Criança e do Adolescente.
Analisaremos os aspectos relevantes da necessidade e importância da doutrina
da proteção integral, bem como dessa nova visão apresentada pelo Estatuto da
Criança e do Adolescente, em face dos menores, os quais são tratados como
pessoas em condição peculiar de desenvolvimento.
Faremos uma abordagem dessa visão apresentada pelo Estatuto da Criança e do
Adolescente, da qualidade de menores ainda em desenvolvimento, e da
necessidade da doutrina da proteção integral à criança e ao adolescente,
abordando alguns aspectos que a compõem, os quais, como veremos, são vitais
para os menores.
Com isso, cremos que tanto a doutrina da proteção integral será compreendida,
como a nova visão apresentada pelo Estatuto da Criança e do Adolescente, que
enfoca o menor como pessoa em condição peculiar
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