Submitted by Pedro Barros (pedro.silvabarros@ufpe.br) on 2018-10-05T22:32:55Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Ana Raquel Marinho Correia.pdf: 2999222 bytes, checksum: e3fa108193a111ac817e772ce4ad66bc (MD5) / Approved for entry into archive by Alice Araujo (alice.caraujo@ufpe.br) on 2018-11-14T22:05:46Z (GMT) No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Ana Raquel Marinho Correia.pdf: 2999222 bytes, checksum: e3fa108193a111ac817e772ce4ad66bc (MD5) / Made available in DSpace on 2018-11-14T22:05:46Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Ana Raquel Marinho Correia.pdf: 2999222 bytes, checksum: e3fa108193a111ac817e772ce4ad66bc (MD5) Previous issue date: 2017-06-30 / A Tecnologia da Informação é um grande fator de sucesso para uma organização quando a Governança de TI é eficaz. Nesse sentido, buscou-se avaliar como está sendo a atuação do Comitê de TI nos Institutos Federais, uma vez que este colegiado é considerado como um dos principais responsáveis por efetivar a Governança de TI; bem como apresentar os Fatores Críticos de Sucesso (FCS) dos comitês de TI dos Institutos Federais de Ensino. Os procedimentos metodológicos utilizados foram pesquisa exploratória, bibliográfica, análise documental e survey, onde foi aplicado o método Estudo de Caso realizado em três Institutos Federais. Os dados obtidos foram comparados com os mecanismos de Governança de TI considerados responsáveis pela sua efetividade. Os resultados indicam que há institutos cujo comitê atua próximo de modelos ideais, enquanto outros apresentam atuação relativamente distante destes modelos, precisando realizar grandes evoluções. Um dos Fatores que tem grande influência sobre a atuação dos comitês é a sua composição e o apoio da Alta Administração do Instituto. Foi disponibilizado também uma tabela com 32 FCS considerados relevantes para a realização dos objetivos do colegiado de maneira satisfatória. / Information Technology is a great success factor for an organization when IT Governance is effective. In this sense, it was tried to evaluate how the IT Committee is acting in the Federal Institutes, since this collegiate is considered as one of the main responsible for effecting IT Governance; as well as to present the Critical Success Factors (FCS) of the IT committees of the Federal Institutes of Education. The methodological procedures used were exploratory, bibliographic, documentary analysis and survey, where the Case Study method was applied in three Federal Institutes. The obtained data were compared with the IT Governance mechanisms considered responsible for its effectiveness. The results indicate that there are institutes whose committee acts close to ideal models, while others present relatively distant performance of these models, needing to make great evolutions. One of the Factors that has a great influence on the work of the committees is its composition and the support of the High Administration of the Institute. A table was also made available with 32 FCS considered relevant for achieving the objectives of the collegiate in a satisfactory manner.

Materiais com fases intermetálicas têm sido avaliados para aplicações estruturais em altas temperaturas devido à baixa massa específica e interessantes propriedades de resistência mecânica e resistência à oxidação de vários compostos. As ligas de Ti são reconhecidas pela sua excelente combinação de alta-resistência, baixa massa específica e alta resistência à corrosão. Tendo em vista a importância de estudos em temperaturas na faixa de 700 a 1000 oC para futuras aplicações, avaliou-se neste trabalho as relações de fases do sistema Ti-Si-B na região rica em Ti nesta faixa de temperatura. Sabendo-se que a utilização de técnicas de solidificação rápida permite a obtenção de ligas com maior homogeneidade química e microestruturas finas, utilizou-se a técnica \"splat-cooling\" de solidificação rápida para produção das amostras, no sentido de obter microestruturas de equilíbrio em tempos e temperaturas menores nos tratamentos térmicos. As técnicas de microscopia, difração de raios X, análise térmica e dureza foram utilizadas para caracterização dos materiais. O processo de solidificação rápida (\"splat cooling\") promoveu refinamento de microestrutura e formação de fase amorfa em diversas composições de liga com temperaturas de início de cristalização (Tx) na faixa de 524 a 641oC. Foram confirmadas a estabilidade das fases αTi, Ti6Si2B e Ti3Si a 700oC e 1000oC. Os valores de dureza dos discos solidificados rapidamente ficaram na faixa de 434 HV a 1207 HV. / Materials with intermetallic phases have been evaluated for structural applications at high temperatures due to low specific mass and attractive mechanical properties as high-strength and oxidation resistance of various compounds. Ti alloys are recognized for their excellent combination of high-strength, low specific mass and high oxidation resistance. About future applications, studies at temperatures ranging from 700 to 1000 oC are important, we evaluated in this work the phase relationships of the system Ti-Si-B in the Ti-rich region in this temperature range. Knowing that the use of rapid solidification techniques results in alloys with higher chemical homogeneity and fine microstructure, the \"splat-cooling\" technique was used to produce the samples, in order to obtain stable microstructures in lower times and temperatures at the heat treatment. Microscopy, X-ray diffraction, thermal analysis and hardness measurement techniques were used for the materials characterization. The rapid solidification - splat cooling promoted the refinement of microstructure and even the formation of amorphous phase in the microstructure of materials with initial temperatures of crystallization (Tx) in the range from 524 to 641oC. We confirmed the stability of the phases αTi, Ti6Si2B and Ti3Si at 700oC and 1000oC. The hardness of the rapidly solidified discs were in the range of 434 HV to 1207 HV.

Made available in DSpace on 2014-06-12T17:42:35Z (GMT). No. of bitstreams: 2 arquivo7488_1.pdf: 2696600 bytes, checksum: c580dacde3637e2e5e3b13d9ba753aab (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2005 / Atualmente, as empresas estão se tornando cada vez mais dependentes de informações para alcançarem seus objetivos institucionais. As empresas privadas precisam de informações para competir no mercado; as públicas, para garantir o bem estar da população. Em qualquer caso, a área de tecnologia da informação (TI) exerce um papel fundamental que é o de apoiar a estratégia empresarial. No entanto, evidências históricas têm mostrado que as empresas falham ao investir nessa área, seja por ineficiência no seu modelo de gestão ou no de governança. Ademais, nem sempre esses investimentos são vistos pelos executivos como justificáveis, considerando que, muitas vezes, eles tendem a fixar atenção apenas no retorno financeiro que da tecnologia da informação pode advir. Faltam, neste caso, métricas não financeiras capazes de avaliar a contribuição dessa área à organização. Este trabalho apresenta um modelo de governança de TI, baseado no Balanced Scorecard e Quality Function Deployment. Tais ferramentas serão utilizadas no planejamento da função, de forma a alinhá-lo à estratégia do negócio, dotá-lo de métricas de avaliação e identificar as necessidades de sistemas informações para, finalmente, priorizar investimentos. Concluindo, será apresentado um estudo de caso com a área de TI da Secretaria de Defesa Social de Pernambuco

Kyle Heller, for the Master of Science degree in Mechanical Engineering, presented on October 2020, at Southern Illinois University Carbondale.MAJOR PROFESSOR: Dr. Kanchan Mondal Using powder X-ray diffraction, a material can have its crystalline structure identified. Powder X-ray diffraction alone is not enough if a material is unknown. Usually the exact chemical formula of the material is known, or a secondary analytical method is used to extract additional data in order to analyze the crystalline structure using Bragg’s law and the interplanar relationships. Secondary analytical methods are not as easy or inexpensive though. Generic values could be placed into the more basic structure types to obtain a rough idea of potential crystal types including space groups for the material based on its diffraction peaks. However, with a material that has an unknown spacing between its atoms (d-spacing) this is harder to implement. Thus, the use of a secondary software was employed to further analyze the possibilities. In this thesis, the software used for data extraction and refining were Expo 2014 and CrystalMaker X paired with CrystalDiffract and the final visualization was achieved using Endeavor. Two different titanium based organic inorganic halide perovskites (Dye 3 and Dye 4) prepared at different temperatures were evaluated to identify the crystallographic structure using only x-ray data available. The crystal parameters were calculated, and potential unit cells were visualized. Both the materials were found to be 4 (ABX3) type perovskites. The organic component for Dye 3 was methyl ammonium ion and that of Dye 4 was formamidinium ion. These perovskites have shown potential for use as sensitizers in visible light photovoltaic cells. It was concluded that Dye 4 was orthorhombic with a space grouping of C m c a (space group 64). The associated values were a = b =7.94 Å and c =11.55 Å. Dye 3 was also found to be orthorhombic with space grouping of P c c n (space group 56) being a better fit than C m c a. The associated values were a=b=16 Å and c=11 Å.

In order for additive-manufactured parts to become widely utilized and trusted in application, their mechanical properties must be characterized. This study investigates the fatigue behavior and failure mechanisms of Ti-6Al-4V specimens fabricated using Laser Engineered Net Shaping (LENS), an additive manufacturing (AM) process. Fully-reversed strain-controlled fatigue tests were conducted on Ti-6Al-4V specimens manufactured via LENS in their as-built and heat-treated conditions. Scanning Electron Microscopy (SEM) is used to examine the fracture surfaces to qualify the failure mechanism, crack initiation sites, and defects. Due to the relatively high localized heating and cooling rates experienced during deposition, fabricated parts possess anisotropic microstructures and different mechanical properties than those of their traditionally-manufactured wrought counterparts. Porosity promotes unpredictable fatigue behavior, as evidenced by data scatter. Pore shape, size, location, and number were found to impact the fatigue behavior of additive-manufactured parts.

No description available.

La Tecnología de la Información (TI) es considerada una herramienta relevante para obtener ventajas competitivas, lo que ha motivado a las empresas a realizar inversiones cada vez más en tecnología. Sin embargo, el volumen y la variedad de las inversiones en TI requieren nuevas herramientas y técnicas para ayudar a los administradores en el proceso de evaluación de esta tipología de inversiones caracterizadas por su alto contenido de activos intangibles. En primer lugar esta tesis describe cuál es la percepción que tienen el empresario y profesional contador respecto de las inversiones en TI; y en segundo lugar, propone un modelo para evaluar proyectos de inversión en tecnología de la información (TI) cuando no existen activos financieros comparables y la información es ambigua. El modelo propuesto de valoración específico para las inversiones en TI permite contemplar la flexibilidad e incertidumbre, y se presenta como herramienta para el análisis estratégico de inversiones utilizando un esquema de posibilidad que aplica matemáticas borrosas y distribuciones triangulares. / The Information Technology (IT) is considered a relevant tool for competitive advantage, which has motivated companies to invest increasingly in technology. However, the volume and variety of IT investments require new tools and techniques to help managers in the process of evaluating this type of investments characterized by its high content of intangible assets. In first place the present thesis describes the kind of perception that entrepreneur and accountant have regarding with IT investment; and secondly proposes a model for evaluating investment projects in information technology (IT) in the absence of comparable financial assets and the information is ambiguous. The proposed assessment for specific IT investments contemplate model allows flexibility and uncertainty, and is presented as a tool for strategic investment analysis using a scheme that applies fuzzy math ability and triangular distributions.

Em radioterapia a entrega de doses deve apresentar incerteza máxima de 5%. Para isso, realiza-se o controle de qualidade dos equipamentos usados. Para feixes de raios X de kilovoltagem (kV), a câmara de ionização (CI) de ar-livre é instrumento de referência para determinar o kerma no ar. Na prática clínica, são usadas CIs de placas paralelas, dependendo da energia dos feixes. Segundo o TRS-398, as CIs usadas nestes feixes deveriam ser calibradas em dose absorvida na água, no entanto, no Brasil ainda não há um método implantado para este tipo de calibração. Para agravar a situação, atualmente, não se tem também disponíveis no Brasil serviços de calibração para CI em kerma no ar ou exposição nesta faixa de energia e muitos serviços ainda utilizam feixes kV, com a sua dosimetria mantida pelas condições disponíveis em cada serviço. Essa pesquisa tem o objetivo de estudar a resposta do TLD quando irradiado com feixes de kV, a fim de obter uma alternativa dosimétrica para verificações de doses nestes feixes. Utilizamos dois grupos com 100 TLDs, que foram calibrados por uma fonte de Césio-137. Quatro equipamentos diferentes de raios X de kV foram usados para levantamento de curvas relacionando as doses lidas pelos TLDs e as doses calculadas pela dosimetria de cada equipamento. Para o estudo da dependência energética, realizamos correções nas medidas utilizando três diferentes métodos. Após observarmos que os fatores de correção da dependência energética variam quando comparados entre si, calculamos o valor médio desses fatores e os utilizamos como fator de correção ótimo, obtendo variações médias de -2,8% entre as doses entregues em comparação com as doses lidas, sendo a máxima variação 17% e a mínima variação -23% entre os equipamentos. / In radiotherapy the doses must be delivered with a maximum deviation of 5% in comparison to those planned. Therefore, it\'s necessary to ensure the quality of the equipment used. For kilovoltage (kV) X-rays beams the dosimetry standard reference instrument is a free-air ionization chamber (IC). In usual clinical procedures, plane-parallel IC are used, depending on the beam\'s energy. The TRS-398 says that the ionization chambers used for those beam should be calibrated in absorbed dose to water; nevertheless there is not a method for such a calibration in Brazil. Nowadays, there isn\'t even an available IC calibration service in air kerma or exposure in this range of energy in the country, a lot of services in Brazil still make good use of kV radiation therapy and its dosimetry is limited by the local available conditions. This research\'s goal is to study the thermoluminescent dosimeter (TLD) response when irradiated by kV beams to come up with a dosimetric alternative for the verification of absorbed doses for those beams. We have used two groups composed by 100 TLDs each, whose calibration was done using a source of Cesium-137. Four different kV X-rays equipments were used to create the curves showing the relation between TLDs response and the actual doses calculated by the dosimetry used for each equipment. Three different methods were used to study the dosimeters energetic dependency. After we noticed that the factors obtained using each method were considerably different from each other in the same group, we calculated the mean values of these groups of factors and we set the mean values as an optimal correction factor. We obtained mean deviations of -2.8% among the doses delivered in comparison to the TLDs doses responses - the maximum deviation was 17% and the minimum was -23% among the equipaments tested.

Ces travaux de thèse s'inscrivent dans le cadre du projet européen ACCENT qui fait suite au projet européen ManHIRP (2001-2005). Ces travaux ont pour objectifs principaux de développer une méthodologie expérimentale permettant d'établir une fenêtre de conditions de coupe garantissant une intégrité matière acceptable de la pièce en Ti-6Al-4V usinée, en s'appuyant sur la mesure des signaux des moyens de surveillance en cours d'usinage.Une attention particulière s'est portée sur l'identification et la classification des anomalies géométriques et de celles produites sur la surface usinée en fonction de la vitesse de coupe et de l'avance. Parallèlement aux investigations sur les anomalies géométriques et de surface, une étude du mode d'endommagement de l'outil en carbure cémenté WC-Co non revêtu et de celle de l'évolution des signaux de surveillance ont conduit à une bien meilleure compréhension des phénomènes liés à la coupe.Les anomalies générées en sous-couche de la surface usinée, telles que les couches à grains déformés et les « couches blanches » ont été étudiées par l'intermédiaire d'analyses métallurgiques fines comme la microsonde de Castaing et par des observations et des analyses au microscope électronique à transmission (MET). Des mesures de microdureté et de contraintes résiduelles ont complété ces analyses chimiques et microstructurales. Aussi, la connaissance de l'état métallurgique et mécanique de ces anomalies a permis de déduire leur genèse et les mécanismes de déformation et de transformations métallurgiques (phases et taille de grains) qui ont opéré en sous-couche du Ti-6Al-4V. Le suivi par la technique de l'analyse d'images des paramètres microstructuraux attachés aux grains globulaires alpha a conduit à mieux comprendre l'écoulement de la matière selon les directions de coupe et d'avance ainsi que les mécanismes de dissolution de ces phases globulaires alpha lorsque l'effet thermique prend le pas sur l'effet mécanique pendant l'usinage. A l'issue de ces caractérisations métallurgiques, des corrélations ont été entreprises entre les anomalies générées et les signaux des moyens de surveillance. Celles-ci s'appuient principalement sur les efforts radiaux dont l'évolution singulière au cours du temps indique l'apparition de défauts. L'amplitude de cet effort radial se corrèle avec la profondeur de la couche de Ti-6Al-4V affectée thermomécaniquement. / The scientific works presented in this thesis is taken place within the framework of an European project ACCENT which is the continuity of the ManHIRP European project (2001-2005). The main aim of these studies is the development of an experimental approach allowing of the determination of an acceptable surface integrity within the validity domain according to the cutting parameters by using the recorded monitoring signals during turning operation. The identification and the classification of the geometrical anomalies generated on the machined surface versus the cutting speed and feed rate were especially investigated. At the same time, damage on uncoated cemented carbide and evolution on process monitoring signals have conducted to a better understanding of cutting phenomena. The anomalies generated within the machined sub-surface such as the highly worked layers and “white layers” were studied with fine metallurgical analysis like the use of Castaing microprobe and transmission electron microscopy (TEM). In addition, micro-hardness and residual stresses measurements have completed the previous analysis. The knowledge of the metallurgical and mechanical states within the sub-layer have enabled to deduce the causes of their formation and to define the deformation mechanisms and the metallurgical transformations (phases and grains size) which have occurred during the machining operation. The tracking of the microstructural features related to globular alpha grains by the investigations of the images analysis have led to a better understanding of material flow according to the cutting and feed directions. Also, the dissolution phenomena of globular alpha grains occurring when the thermal loading becomes preponderant before the mechanical one has been highlighted. After these metallurgical analyses, correlations between the surface integrity and the process monitoring signals have been found. The singular evolution of the radial force signal indicates the anomalies appearance. Its amplitude is linked with the depth of the thermo-mechanically affected sub-layer of the machined surface.

O desenvolvimento de biomateriais com estrutura porosa visa permitir uma boa ancoragem biológica através do crescimento do tecido ósseo no interior dos poros, além de no caso de algumas ligas de titânio, proporcionar valores de módulo elástico semelhantes ao do osso, prevenindo assim o insucesso por reabsorção óssea na interface com o implante. O objetivo deste estudo foi avaliar o processamento de implantes porosos à base de titânio produzidos por metalurgia do pó, utilizando polímeros naturais como aditivos (albumina, amidos de arroz, batata, milho e a gelatina), e analisar a osteointegração desses implantes por ensaio in vivo. Foram obtidas, amostras de titânio comercialmente puro (Ticp) e da Liga Ti-13Nb-13Zr pelos processos de space-holder e suspensão; os polímeros naturais foram removidos termicamente (350°C/1h) previamente a sinterização (1300°C/1h e 1300°C/3h, respectivamente). As metodologias de processamento utilizando aditivos de baixo custo propiciaram a obtenção de implantes metálicos porosos de maneira simplificada, com porosidades diferenciadas, boa homogeneidade estrutural, grau de porosidade adequado (entre 40% e 60%), distribuição e tamanho dos poros conforme o polímero natural formador. Na caracterização biológica, o teste in vitro de citotoxicidade validou a utilização dos implantes para a realização do teste in vivo. A avaliação da osteointegração foi realizada em coelhos da raça New Zealand em períodos de 49 dias. Na análise histológica por microscopia eletrônica de varredura e fluorescência, foram obtidos os resultados quantitativos e qualitativos da osteointegração, com crescimento ósseo em todos os implantes, apresentando osteocondutividade. Os melhores resultados ocorreram em implantes com porosidade homogênea, e com tamanho médio de poros entre 100 e 200 μm. Assim, os materiais porosos de titânio e da liga Ti-13Nb-13Zr produzidos com os polímeros naturais (amido de arroz, amido de batata, amido de milho, gelatina e albumina), permitiram a nutrição e manutenção necessárias para a sobrevivência das células, comprovando a osteointegração e osteocondução dos implantes desenvolvidos. / The development of biomaterials with porous structure, seeks to allow a good biological anchorage through bone tissue ingrowth within the pores, besides to propitiate elastic modulus values similar to bone, thus preventing the failure by bone resorption, on implants interface. The goals of this study was to evaluate the processing of titanium based porous implants by powder metallurgy (PM), using natural polymers as additive (rice, potato and corn starches, albumin and gelatin), and evaluate these implants osseointegration by in vivo assay. Samples were obtained of commercially pure titanium (cpTi) and Ti-13Nb-13Zr alloy by space-holder and suspension techniques; the natural polymers were removed by thermal treatment (350C/1h) prior to sintering (1300C/1h and 1300C/3h respectively). The processing methodologies using low cost additives propitiate the production of porous metallic implants in a simplified manner, with differentiated porosities, good structural homogeneity, proper porosity degree (between 40% and 60%), distribution and pore size as the related natural polymer. The biological characterization was first performed in vitro with a cytotoxicity test, which allowed the use of implants in vivo. The osseointegration evaluation was performed in New Zealand White rabbits for 49 days period. Histological analyses with scanning electron microscopy and fluorescence microscopy were obtained quantitative and qualitative results of osseointegration, with bone growth in all implants, presenting osteoconductivity. The best results were in implants with homogenous porosity and with mean pore size between 100 and 200 μm. Thus, titanium and Ti-13Nb-13Zr alloy porous materials produced with natural polymers (rice, potato and corn starches, albumin and gelatin), allowed the nutrition and nourishing needed to bone cells survival, proving the osseointegration and osteoconduction features of developed implants.