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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

Análise termodinâmica da formação de Al2O3 durante o lingotamento contínuo através da interação química entre pós fluxantes sem flúor e uma liga de Fe líquido saturada com alumínio e oxigênio

Silva, Daniel dos Reis January 2010 (has links)
Pós fluxantes são escórias sintéticas utilizadas no processamento do aço via lingotamento contínuo com o objetivo de promover maior qualidade superficial ao produto lingotado. Para tanto, os pós fluxantes desempenham as seguintes funções: (i) promoção do isolamento térmico e químico do aço, (ii) absorção das inclusões nãometálicas provenientes do aço, (iii) promoção da lubrificação do molde e (iv) controle da transferência de calor entre o aço e o molde. O bom desempenho de cada função está diretamente relacionado às propriedades físicas e químicas que os pós apresentam, as quais são funções de sua composição química. Durante o processo de lingotamento, os pós fluxantes sofrem alterações em sua composição original proporcionadas por diferentes mecanismos que afetam as propriedades dos pós fluxantes. Um dos principais mecanismos responsáveis pelas alterações da composição das escórias é a interação química que ocorre entre o aço líquido e o pó fluxante fundido. Nesse trabalho foram realizadas simulações via aplicativo termodinâmico FactSage com o intuito de avaliar as interações entre metal líquido e escória. Três sistemas simples para a escória – um ternário (CaO-Al2O3-SiO2), um quaternário (CaO-Al2O3-SiO2-MgO) e um quinário (CaO-Al2O3-SiO2-MgO-Na2O) – e uma liga de Fe saturada em alumínio e oxigênio – 0,1%, 0,01% e 0,001% de Al – foram escolhidos para a realização das simulações, visando avaliar o incremento de Al2O3 da escória através da interação entre o alumínio dissolvido no ferro e a sílica presente na escória. O aumento do teor de alumina na escória foi quantificado para cada um dos três sistemas estudados em função do teor de Al e da razão S/M (kg de pó fluxante/t de metal líquido). Foram realizadas curvas de resfriamento para as escórias – que sofreram alterações em sua composição – para avaliar a influência da variação da composição sobre o comportamento de solidificação destas, baseadas em diagramas pseudobinários. Por fim, foram realizados cálculos de viscosidade para estas escórias através do modelo IRSID, para analisar a influência da composição sobre a viscosidade. Mostrou-se, para as condições escolhidas, que as alterações da composição química das escórias devido às interações entre metal líquido e escória são significativas, afetando as propriedades dos pós fluxantes, tais como seu comportamento de solidificação e sua viscosidade. / Mold powders are synthetic slags used in steel processing via continuous casting in order to promote greater surface quality to casting product. Thus, the mold powders perform the following functions: (i) promotion of the thermal and chemical insulate of steel, (ii) absorption of non-metallic inclusions from the steel, (iii) promotion of the lubrication of the mold and (iv) control of the heat transfer between steel and mold. The good performance of each function is directly related to physical and chemical properties presented by the powders, which are functions of their chemical compositions. During casting process, the mold powders undergo changes in their original composition provided by different mechanisms that affect the properties of mold powders. One of the main mechanisms responsible for changes in the composition of the slag is the chemical interaction that occurs between liquid steel and molten mold powders. In this work, simulations were carried out via thermodynamics software FactSage with the purpose of evaluating the interactions between the liquid metal and slag. Three simple systems – a ternary (CaO-Al2O3-SiO2), a quaternary (CaO-Al2O3- SiO2-MgO) and a quinary (CaO-Al2O3-SiO2-MgO-Na2O) – and a Fe alloy saturated with aluminum and oxygen – 0,1%, 0,01% and 0,001% Al – were chosen to perform the simulations in order to evaluate the increase of Al2O3 in slag through the interaction between the dissolved aluminum in iron and silica present in the slag. The increase of alumina content in the slag was quantified for each of the three systems studied as a function of Al content and the ratio S/M (mold powder kg/t liquid metal). Cooling curves were performed for slags – that suffered changes in their composition – to assess the influence of the composition variation on the behavior of slags, based on the pseudo-binary diagrams. Calculations of viscosity for these slags through the IRSID model to analyze the influence of chemical composition on the viscosity were performed. For the conditions chosen, it was shown that changes in chemical composition of the slag due to interactions between liquid metal and slag are significant, affecting the properties of fluxing powders, such as the solidification behavior and viscosity.
72

Aplicações do geoplano no ensino básico

Pinheiro, Rodrigo Pereira 27 February 2014 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-02-23T20:06:20Z No. of bitstreams: 1 rodrigopereirapinheiro.pdf: 19219092 bytes, checksum: 981c7f639918c247012b7020c94952e0 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-03-03T13:24:15Z (GMT) No. of bitstreams: 1 rodrigopereirapinheiro.pdf: 19219092 bytes, checksum: 981c7f639918c247012b7020c94952e0 (MD5) / Made available in DSpace on 2016-03-03T13:24:15Z (GMT). No. of bitstreams: 1 rodrigopereirapinheiro.pdf: 19219092 bytes, checksum: 981c7f639918c247012b7020c94952e0 (MD5) Previous issue date: 2014-02-27 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Na matemática, quando se consegue associar o concreto com o abstrato, colhem-se muitos frutos. Dada as dificuldades encontradas para ensinar Geometria Plana no Ensino Básico, o presente estudo tem como objetivo aplicar o Geoplano na tentativa de melhorar a aprendizagem dos alunos bem como aumentar o interesse dos mesmos no assunto. O empenho em estudar melhor este material surgiu através de um minicurso realizado na cidade de Juiz de Fora no início de 2013, no qual percebi nesse material uma grande oportunidade de trabalhar os diversos conceitos de geometria bem como resolver problemas de baixa e grande complexidade. Nesse material, nós encontraremos a fórmula de Pick, que é uma alternativa para o cálculo de áreas de diversos polígonos simples. Foram feitas aplicações nos 7º, 8º e 9º anos do Ensino Fundamental na Escola Estadual Francisco Manuel em Descoberto, Minas Gerais, onde um dos pontos mais marcantes foi a interatividade dos alunos com o material. / In mathematics, when you can associate the concrete with the abstract, men gather many fruits. Given the difficulties encountered in teaching plane geometry in formal education, this study aims to apply the Geoplano in an attempt to improve student learning and increase interest in the same subject. The commitment to better study this material came through a short course held in the city of Juiz de Fora in early 2013, in which I realized that material a great opportunity to work the various concepts of geometry and how to solve problems of low and high complexity. In this material, we find the formula for Pick, which is an alternative to the calculation of various areas of simple polygons. Applications were made on the 7th, 8th and 9th years of elementary school in the State School Discovered in Manuel Francisco, Minas Gerais, where one of the most striking points was the interaction of students with the material.
73

Área de figuras planas e Teorema de Pick: uma abordagem diferenciada para alunos do 6° ano do Ensino Fundamental

Rodrigues, Ivana do Monte 06 June 2014 (has links)
Submitted by Lúcia Brandão (lucia.elaine@live.com) on 2015-12-14T16:33:17Z No. of bitstreams: 1 Dissertação - Ivana do Monte Rodrigues.pdf: 13975389 bytes, checksum: 64cd8442fee6590aab6a0ae9f0f5728d (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-01-20T17:26:25Z (GMT) No. of bitstreams: 1 Dissertação - Ivana do Monte Rodrigues.pdf: 13975389 bytes, checksum: 64cd8442fee6590aab6a0ae9f0f5728d (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-01-20T17:27:53Z (GMT) No. of bitstreams: 1 Dissertação - Ivana do Monte Rodrigues.pdf: 13975389 bytes, checksum: 64cd8442fee6590aab6a0ae9f0f5728d (MD5) / Made available in DSpace on 2016-01-20T17:27:53Z (GMT). No. of bitstreams: 1 Dissertação - Ivana do Monte Rodrigues.pdf: 13975389 bytes, checksum: 64cd8442fee6590aab6a0ae9f0f5728d (MD5) Previous issue date: 2014-06-06 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The main objective of this work is to introduce students to the 6th grade of elementary school a differentiated approach to the study of plane figures areas and present a new way of performing the areas of measurement: the Pick's Theorem. From a brief history of the area calculation, we conducted a demonstration of the main areas of plane figures worked in elementary school using the concept of equivalence, and extend the study to limited areas by other curves approaching the concept of integral. Then we expose the Pick's Theorem and its demonstration and described the practice developed with students. The activity carried out in the 2nd half of 2013 and 1 / half of 2014 with the volunteer students of the College Math Club Militar de Manaus aimed to develop a major planned skill in the NCP [6] (National Curriculum Standards for Teaching Mathematics): joint scientific and technological knowledge in an interdisciplinary perspective. Explore the deduction of the areas of the full figures using the TANGRAM, providing education in a playful, participatory and argumentative. Introducing Pick's Theorem and apply it in the rough measure of the areas of states and regions of Brazil using maps and graph paper, the concept of working ranges and providing an interdisciplinary activity. / O objetivo principal do trabalho é apresentar aos alunos do 6° ano do Ensino Fundamental uma abordagem diferenciada sobre o estudo de áreas de figuras planas e apresentar uma nova forma de realizar a medição de áreas: o Teorema de Pick. A partir de um breve histórico sobre o cálculo de áreas, realizamos a demonstração das áreas das principais figuras planas trabalhadas no ensino fundamental utilizando o conceito de equivalência, e estendemos o estudo para áreas limitadas por outras curvas abordando o conceito de integral. Em seguida, expomos o Teorema de Pick e sua demonstração e descrevemos a prática desenvolvida com os alunos. A atividade realizada no 2 ° semestre de 2013 e 1/ semestre de 2014 com os alunos voluntários do Clube de Matemática do Colégio Militar de Manaus visou desenvolver uma importante habilidade prevista no PCN [6] (Parâmetros Curriculares Nacionais para o Ensino da Matemática): articular o conhecimento científico e tecnológico numa perspectiva interdisciplinar. Exploramos a dedução das áreas das figuras plenas utilizando o TANGRAM, proporcionando o ensino de forma lúdica, participativa e argumentativa. Apresentamos o Teorema de Pick e o aplicamos na medição aproximada das áreas de estados e regiões do Brasil utilizando mapas e papel quadriculado, trabalhando o conceito das escalas e propiciando uma atividade interdisciplinar.
74

Cálculo das fórmulas de Euler e Pick no geoplano e no GeoGebra / Euler and pick’s numerical methods in calculus with geoplan and GeoGebra

Carvalho, Wesley da Silva 09 December 2016 (has links)
Submitted by Cássia Santos (cassia.bcufg@gmail.com) on 2017-03-20T12:17:35Z No. of bitstreams: 2 Dissertação - Wesley da Silva Carvalho - 2016.pdf: 2739140 bytes, checksum: 009cb3705c3ac6a28927493419d88e0c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-03-20T14:06:03Z (GMT) No. of bitstreams: 2 Dissertação - Wesley da Silva Carvalho - 2016.pdf: 2739140 bytes, checksum: 009cb3705c3ac6a28927493419d88e0c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-03-20T14:06:03Z (GMT). No. of bitstreams: 2 Dissertação - Wesley da Silva Carvalho - 2016.pdf: 2739140 bytes, checksum: 009cb3705c3ac6a28927493419d88e0c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-12-09 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this dissertation, we first state Euler's polyhedral formula for a set of points with Euler characteristic 2. We address the two known ways to prove Euler's Theorem: beginning with the classical proof by using Euclidian Geometry and afterwards we take the advantage of Spherical Geometry to give another proof. Furthermore, we address a version of Euler's formula for planar polyhedron, as well as, Pick's formula and the equivalence between Euler and Pick's formula. In the end, we provide application of Euler and Pick's formula, via two pedagogy tools Geoplano and GeoGebra, by giving examples to teach in classroom. / Esta dissertação trata inicialmente da Fórmula de Euler e de sua validade para os conjuntos de pontos com característica de Euler igual a 2. São feitas duas demonstrações da Fórmula de Euler, uma utilizando conceitos de Geometria Euclidiana e uma outra via Geometria Esférica, além da apresentação de uma versão para poliedros planos da Fórmula de Euler. Posteriormente, é apresentada a Fórmula de Pick para o cálculo de áreas de polígonos simples reticulados e sua relação de equivalência com a Fórmula de Pick para poliedros planos. Finalmente mostramos duas possibilidades de trabalho com a Fórmula de Pick, no Geoplano e no software GeoGebra.
75

Reversal of the NPC Phenotype by START Domain Proteins

Sparrer, Tavis H 01 January 2017 (has links)
Niemann Pick Type C (NPC) disease is a fatal childhood neurological disease caused by mutations in the NPC-1 protein, resulting in cholesterol buildup in the late endosomes. StarD4 and StarD5 are cholesterol binding proteins that play a role in the intracellular cholesterol transport. In this study we overexpress StarD4 and StarD5 in in vitro and in vivo models, and find evidence of amelioration of the NPC phenotype. This study demonstrates that the overexpression of these proteins has the potential to be a therapeutic treatment for NPC disease.
76

'The World is Not a Safe Place for Men': The Representational Politics of the Manosphere

Lilly, Mary January 2016 (has links)
This thesis offers an overview of the representational politics of the online antifeminist community known as the ‘manosphere’. It analyzes how gender and gender politics are represented in the discourse, with an eye to how traditional gender constructs, and traditional gendered norms and inequalities, are reproduced. This project—the first study to focus exclusively on the manosphere—contributes to our understanding of the community in two ways; it addresses a significant gap in the literature on the topic, and it tests the accuracy of the ‘conventional wisdom’ on the manosphere. Using mixed-methods critical discourse analysis, the study analyzed the discourse of the two primary subcultures of the community, and found that traditional gender norms and relations are reproduced therein, and that for the most part the conventional wisdom is accurate: femininity and women are disparaged, masculinity is imagined to be ‘in crisis’ (constantly under siege by feminizing forces), and feminism is represented as hypocritical and oppressive.
77

Factors affecting the in vitro embryo production in cattle associated to ovum pick up sistem

Cebrián Serrano, Alberto 21 March 2013 (has links)
La producción de embriones mediante la recuperación de ovocitos inmaduros por ovum pick up (OPU), y su posterior maduración, fecundación y cultivo en el laboratorio in vitro, presenta numerosos beneficios para optimizar el potencial reproductivo, tanto de hembras como de machos. Además, frente a la superovulación convencional mediante tratamiento hormonal y la recogida de embriones in vivo, la producción in vitro de embriones (PIVE) con ovocitos de OPU ofrece considerables ventajas. Sin embargo, actualmente la PIVE continua siendo ineficiente e incapaz de producir embriones de calidad similar a los in vivo, lo cual ha limitado una aplicación más amplia de esta tecnología. Así pues, el objetivo de esta tesis fue la optimización de la PIVE en ganado vacuno, condicionado por las peculiaridades y deficiencias de la PIVE cuando los ovocitos son recuperados por la técnica de OPU. Con este fin, cinco experimento se llevaron a cabo en esta tesis. En el primero de ellos se estudió el efecto del fluido oviductal bovino (FOb) sobre el desarrollo y la calidad embrionaria (Experimento 1). Las fases del proceso de PIVE en las cuales el cultivo de ovocitos/embriones, bien individualmente o bien en número reducido, pudiera perjudicar el posterior desarrollo hasta el estadio de blastocisto y/o a su calidad, se estudiaron en el Experimento 2. En el Experimento 3 se testó si el desarrollo y la calidad de embriones cultivados in vitro en número reducido podría ser mejorada con la adición conjunta de factor de crecimiento epidérmico, insulina, transferrina y selenio (FCE-ITS) o por el sistema de cultivo de embriones llamado well of well (WOW). Las propiedades protectoras de la melatonina frente a los daños causados por el estrés oxidativo, subsecuentes de las condiciones de PIVE o de un estrés térmico durante la maduración ovocitaria, fueron evaluadas en el Experimento 4. Por último, en el Experimento 5 usamos ovocitos recolectados por OPU para evaluar el efecto del semen sexado sobre / Cebrián Serrano, A. (2013). Factors affecting the in vitro embryo production in cattle associated to ovum pick up sistem [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/27646 / Palancia
78

Development of a Pick-Up-And-Play Gamification Geography Game for Learnability / Utveckling av ett pick-up-and-play gamification geografispel för lärbarhet

Pitarevic, Ermin January 2020 (has links)
Gamification, immersion and flow are well known within game design, and more frequently considered within the development of educational applications. The simplicity and comprehensibility of an educational game can result into improved learning and a more enjoyable experience, as the focus on the gameplay increases with less instructions and a more straightforward approach for playing and learning. The aim is to focus on the relevant areas in order to implement a pick-up-and-play gamification geography game for learnability, as well as understanding the considerations when developing an educational application of this kind. Moreover, the work mainly focuses on the implementation of relevant and central game design elements, including animations, correlated to the researched areas. Given the information and the implementation, evaluation and analyzation were performed using Think-Aloud protocol combined with two scripted tests. Additionally, two slightly modified questionnaires were used, the Game Experience Questionnaire and User Engagement Scale Short Form, as a completion for any uncertainties or missing information after the Think-Aloud protocol. The work has brought up the importance of understanding the correlation between the relevant areas and the game design elements, as well as discussed these in context of this work. Moreover, it describes the importance of the well-balanced usage of animations, which improves the dynamic and engaging experience, while also contributing to a clearer feedback. The Think-Aloud protocol have shown being very useful and effective for the evaluation and analyzation. However, the questionnaires were only useful to some extent, but overall ambiguous and confusing, mainly because of the short playtime by the participants, as well as the difficulties in interpreting the assumptions.
79

Pick interpolation, displacement equations, and W*-correspondences

Norton, Rachael M. 01 May 2017 (has links)
The classical Nevanlinna-Pick interpolation theorem, proved in 1915 by Pick and in 1919 by Nevanlinna, gives a condition for when there exists an interpolating function in H∞(D) for a specified set of data in the complex plane. In 1967, Sarason proved his commutant lifting theorem for H∞(D), from which an operator theoretic proof of the classical Nevanlinna-Pick theorem followed. Several competing noncommutative generalizations arose as a consequence of Sarason's result, and two strategies emerged for proving generalized Nevanlinna-Pick theorems: via a commutant lifting theorem or via a resolvent, or displacement, equation. We explore the difference between these two approaches. Specifically, we compare two theorems: one by Constantinescu-Johnson from 2003 and one by Muhly-Solel from 2004. Muhly-Solel's theorem is stated in the highly general context of W*-correspondences and is proved via commutant lifting. Constantinescu-Johnson's theorem, while stated in a less general context, has the advantage of an elegant proof via a displacement equation. In order to make the comparison, we first generalize Constantinescu-Johnson's theorem to the setting of W*-correspondences in Theorem 3.0.1. Our proof, modeled after Constantinescu-Johnson's, hinges on a modified version of their displacement equation. Then we show that Theorem 3.0.1 is fundamentally different from Muhly-Solel's. More specifically, interpolation in the sense of Muhly-Solel's theorem implies interpolation in the sense of Theorem 3.0.1, but the converse is not true. Nevertheless, we identify a commutativity assumption under which the two theorems yield the same result. In addition to the two main theorems, we include smaller results that clarify the connections between the notation, space of interpolating maps, and point evaluation employed by Constantinescu-Johnson and those employed by Muhly-Solel. We conclude with an investigation of the relationship between Theorem 3.0.1 and Popescu's generalized Nevanlinna-Pick theorem proved in 2003.
80

Sekvenční osazování povrchově montovaných součástek / Sequential Placement of Surface Mounted Devides

Štětina, Hynek January 2015 (has links)
This thesis deals with the design and realization of SMD pick and place machine. Significant part of thesis was focused on computer vision and its application for SMD devices centering. Beside the mechanical construction the control software capable of use in production environment have been realized.

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