As origens dos elementos residuais (trace element) nas ligas à base de Ni provém basicamente de duas fontes: (1) minérios e (2) sucatas. O controle da concentração destes elementos residuais é muito importante, pois afetam as propriedades mecânicas dessas ligas. Alguns estudos mostram que os elementos Pb e Bi têm um sério impacto negativo nos resultados dos ensaios de fluência das ligas a base de Ni. A presença dessas impurezas causa o aumento da quantidade de cavidades nos contornos de grão que resultam em fracasso prematuro na vida útil desse material. Dessa forma, este trabalho tem como objetivo estudar a cinética da remoção de elementos residuais, tais como Pb e Bi da liga VAT32 através da aplicação de vácuo durante a elaboração da liga. Os resultados obtidos demonstraram que a taxa de remoção dos residuais Pb e Bi no refino a vácuo atingiram percentuais de 99,6% e 96,1% respectivamente. Fatores como volume do cadinho, elevação de temperatura, níveis de vácuo abaixo de 10-4 mbar, limpeza do sistema que compreende câmara e cadinho (residuais de corridas anteriores), contribuem significativamente para as taxas acima descritas. Por outro lado, quanto maior o volume de liga fundida, diminuição de temperatura, vácuo deficiente ou contaminação do sistema, a taxa de remoção de Pb e Bi são prejudicadas. / The origins of trace elements in Ni-based alloys come basically from two sources: (1) minerals and (2) scrap. Control of the concentration of trace elements is very important because they affect the mechanical properties of these alloys. Some studies show that the elements Pb and Bi have a serious negative impact on the results of creep tests of Ni based alloys. The presences of these impurities cause the increase of the number of cavities at grain boundaries that result in premature failure of this material. Thus, this work aims to study the kinetics of removal of trace elements such as Pb and Bi in alloy VAT32 by applying vacuum during the preparation of the alloy. The results showed that the rate of removal of residual Pb and Bi in the vacuum refining reached 99.6% and 96.1% respectively. Parameters such as the crucible volume, high temperature, vacuum levels below 10-4 mbar, cleaning of the system which comprises chamber and crucible (residual from previous races), contribute significantly to the rates described above. Moreover, the higher the volume of molten alloy, low temperature, vacuum system contamination and low vacuum pressure decrease, refining degree of Pb and Bi.

Made available in DSpace on 2014-06-12T18:04:20Z (GMT). No. of bitstreams: 2 arquivo7199_1.pdf: 1182475 bytes, checksum: 724962fa64eabf08ab6566504a220672 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2006 / A distribuição Birnbaum-Saunders bi-paramétrica de parâmetros α e β vem sendo amplamente usada para modelar o tempo de vida de materiais e equipamentos. Os estimadores de máxima verossimilhança dos parâmetros que indexam esta distribuição podem não apresentar desempenho satisfatório em amostras de tamanho pequeno. Assim, o cálculo dos vieses destes estimadores torna-se importante, visto que, em geral, quanto menor o tamanho da amostra, maior o viés. A derivação de expressões que permitam calcular os vieses desses estimadores possibilita a obtenção de estimadores corrigidos, que, em principio, são mais precisos que os não-corrigidos. Um dos objetivos deste trabalho é fornecer expressões para os vieses de segunda ordem dos estimadores de máxima verossimilhança dos parâmetros que indexam a distribuição Birnbaum-Saunders bi-paramétrica. Com a finalidade de reduzir os vieses destes estimadores em amostras finitas, utilizam-se correções de viés obtidas a partir de esquemas analíticos [Cox & Snell (1968); Firth (1993)] e por bootstrap [Efron (1979)]. Também apresentamos intervalos de confiança do tipo assintótico, bootstrap percentil, bootstrap BCa e bootstrap-t para os parâmetros desta distribuição. Apresentamos testes de hipóteses para o parâmetro α desta distribuição considerando β como um parâmetro de perturbação. Consideramos o teste da razão de verossimilhanças, cuja estatística de teste possui, assintoticamente, distribuição qui-quadrado sob a hipótese nula. Obtemos, para este teste assintótico, um fator de correção em amostras de tamanho finito. Consideramos ainda uma versão bootstrap do teste da razão de verossimilhanças

Efter en omfattande SAP implementering finns det oftast ännu mer datamaterial i en organisation. Moderna ERP-system som SAP skapar å ena sidan en stor transparens, men å andra sidan förändras processerna och det är viktigt för en organisation att kunna analysera affärsinformation snabbt och enkelt och att kunna reagera på förändringar på marknaden. Detta arbete ska ge en överblick över olika verktyg för ett BI-system i samband med analysen av omsättningen och faktureringsprocessen vid ett aluminiumvalsverk. Processerna har förändrats vid aluminiumvalsverket p g a SAP implementeringen och det är en akut och viktig fråga att bygga upp ett informationssystem som baserar sig på SAP information. Därför valde Man att implementera BI-verktyget Cubeware samt att programmera några SAP Query för att kontrollera faktureringsprocessen. Men första steget vid starten av denna informationsprocess av BI-verktyg var ett Excel-program som på ett enkelt sätt kan analysera data som kommer från faktureringsprocessen. Det visade sig dock snabbt att det fanns problem i denna informationsprocess. Å ena sidan fanns det felaktig information inom SAP systemet, därför utvecklades SAP Query; och å andra sidan har Excel-filen blivit allt för stor och nästan oanvändbar för att kunna göra snabba analyser. Därför implementerades Cubeware i samband med databasen MS SQL Server 2005. I mitt arbete ska jag beskriva denna utvecklingsprocess för informationshanteringen och samtidigt analysera olika felorsaker och beskriva informationskvalitetsutvecklingen.

L’objectif de ces travaux est de développer une nouvelle voie de valorisation de différents coproduits agricoles et forestiers. L’étude s’est focalisée sur l’étape de séparation entre les hémicelluloses et les lignines contenues dans des extraits aqueux obtenus par extrusion bi-vis. La technologie bi-vis du fait de sa modularité a été choisie pour évaluer différentes conditions d’extraction. Les essais ont été menés afin de mettre en évidence l’influence des effets mécanique, thermique et chimique sur l’extraction des hémicelluloses à partir des différentes matrices végétales étudiées. Les travaux ont été conduits soit en conditions hydrothermales, eau sous pression et haute température, soit en conditions faiblement alcalines pour extraire des molécules les plus natives possibles. Ceci a permis d’identifier les conditions d’extraction les plus favorables en fonction des caractéristiques de chacune des biomasses. Dans un second temps, les extraits obtenus, contenants des hémicelluloses et des composés phénoliques, ont été purifiés au moyen de méthode de fixation sur résines d’échange d’ions et d’adsorption. Les travaux se sont focalisés sur la compréhension des mécanismes de fixation des molécules avec des solutions modèles contenant un ou plusieurs solutés. La cinétique et les isothermes d’échanges ont été évaluées pour l’acide férulique, l’acide coumarique et la lignine. Les résultats ont ensuite été comparés à ceux obtenus avec les extraits alcalins. Cette étude a permis d’identifier les mécanismes d’échanges qui interviennent lors de la séparation des complexes lignine-polysaccharides.

L’athérosclérose est une pathologie chronique inflammatoire qui résulte du dérèglement d’une réaction inflammatoire non résolue ayant pour but initial d’éliminer l’accumulation excessive de lipides au niveau de l’intima. Cette élimination est exercée par les monocytes/macrophages, dont l’infiltration et l’accumulation au niveau des lésions contribue à l’inflammation chronique locale.SR-BI est un récepteur scavenger multi-fonction capable de reconnaître un large spectre de ligands allant des lipoprotéines natives et modifiées jusqu’aux endotoxines. Outre de jouer un rôle crucial dans l’homéostasie du cholestérol dans le foie, est considéré comme un PRR capable d’être impliqué dans l’immunité inné. Un nombre croissant de données suggère un rôle athéro-protecteur de SR-BI dans les cellules dérivées de la moelle osseuse et notamment dans les macrophages. La contribution de SR-BI dans les macrophages au cours de l’athérosclérose et l’identification des mécanismes sous-jacents ne sont pas élucidées. Nous avons démontré que la délétion de SR-BI dans les macrophages entraîne une accélération du développement de l’athérosclérose et une augmentation de la cellularité au sein des lésions en absence d’effet sur la cholestérolémie. Ces effets athéro-protecteurs peuvent être attribués à une diminution de l’apoptose et à une augmentation de la prolifération cellulaire au sein des plaques.Nos données suggèrent également que la diminution de la susceptibilité à l’apoptose des macrophages déficients en SR-BI pourrait impliquer la voie d’activation P38. En parallèle de cette étude, le rôle de SR-BI dans la réponse inflammatoire a été exploré dans des conditions d’endotoxémie. / Atherosclerosis is a chronic inflammatory pathology which results from an uncontrolled inflammatory reaction secondary to an abnormal accumulation of lipids in the intima. The lipid clearance is performed by monocytes/macrophages. Their infiltration and accumulation in lesions contribute/ enhance the chronic local inflammation. SR-BI is a multifunction scavenger receptor capable of recognizing and binding a large spectrum of ligands from native and modified lipoproteins to endotoxins. Besides its crucial role in cholesterol homeostasis in the liver, SR-BI is also described as a PRR. An increasing number of data suggests that SR-BI exerts an atheroprotective role in bone marrow-derived cells and in particular macrophages.The specific contribution of SR-BI in macrophages in atherosclerosis development and the identification of the underlying mechanisms have yet to be elucidated.We have demonstrated that SR-BI deletion in macrophages increases atherosclerosis development and lesion cellularity without affecting cholesterolemia. These atheroprotective effects could be explained by decreased apoptosis and increased cell proliferation in plaques.Our data also suggest that the decrease in apoptosis sensitivity in SR-BI deficient macrophages could involve the P38 MAPK and STAT1 signaling pathways.In parallel to this study, the role of SR-BI in the inflammatory response has also been explored in endotoxemia and sepsis.

Self-propagating High-temperature Synthesis (SHS) is the synthesis of solid materials by a reaction wave propagating into the initial reactants, typically two metals, which can alloy exothermically. Typically, experiments are performed with the reactants in powder form, with relatively low density. Recent experiments by Bacciochini et al. revealed much larger flame speeds in densified powders near TMD (theoritical maximum density), obtained by the cold spray process. The present thesis investigates why the flame speed increases dramatically with an increase in density of the powders. The investigation rests on the analytical model formulated by Makino by controlling how the variables are affected by changes in density. Flame speed measurements were performed in mixtures of nickel (Ni) and aluminum (Al) at different initial densities. The density was varied by controlling the cold-pressing of the samples inside metallic channels and tubes. Experiments were also performed in ball-milled powders, in order to permit comparison with the experiments performed by Bacciochini in these mixtures at nearly maximum densities. The measurements revealed that the flame speed increases with the initial density, with a discontinuous transition occurring at approximately 60% theoretical maximum density (TMD). This transition also corresponds to the point where the powders deform plastically during the compaction process, suggesting that the intimate contact between the particles is responsible for the flame speed increase. The flame speed dependence on powder density is attributed to the changes in the heat conductivity of the pressed powders. At high densities, where the powders have plastically deformed, the continuous structure yields conductivities close to the idealized solid matrix. At these high densities, the conductivity was modeled using the Effective Medium Theory (EMT). Analytical predictions of the flame speed, using available thermo-chemical data for the Al-Ni system were found in good agreement with the present experiments at high densities. At low densities, since Al-Ni is a mixture of loose powders, the EMT model is no longer applicable. Thus, the thermal conductivity was experimentally measured and then was fitted using the semi-empirical model suggested by Aivazov. Using this data, Makino's model predicts the correct flame speed dependence observed experimentally. The present thesis has thus established that the dependence of flame speed on density is due mainly to the changes in the structure and thermal conductivity of the powders.

My thesis deals with comparison with Business Intelligence software for data visualization for Microsoft platform to selected open source product. The aim of my thesis is to find visualization software that is suitable for small company and firm can handle visualization by itself. At first there is introduction to issues of Business Intelligence following description of visualization resources of Microsoft platform, specifically Excel, Power View, Power Map and Reporting. Subsequently open source software was chosen that is able to compete with visualization products of Microsoft platform specifically CDE Dashboard from Pentaho platform. There are compared chosen products via proposed scenario and evaluated standards. Finally there are evaluated suitability of individual software for data visualization.

The topic of the current Master's thesis is Business Intelligence's data presentation using maps. Through integrating BI and geographic information systems a new discipline is emerging - Location Intelligence. The main goal of this thesis is to highlight and analyse reporting possibilities of the BI tools in the framework of maps. The theoretical part of this paper is dedicated to the foundation and principles of geographic information systems and their intersection with BI, where such field as Location Intelligence is being created. In the practical part of the thesis the BI tools IBM Cognos and Oracle BI are compared. The comparison is based on the following criteria: field of implementation, visualization, map external sources and performance. The evaluating criteria are defined in the beginning of the practical part as well as the evaluation method. The methods of analysis and information collecting were used to extract and revise the knowledge from specific electronic and printed sources in Czech or English. Sources for the practical part origin from my technical knowledge of the field of BI, as well as practical experience with implementation of map sources as a feature of Business Intelligence. Statistical methods are used for evaluation of the criteria results. The practical and theoretical value of the thesis lies in creating the lucid comparison of implementation of the map sources into the selected BI tools and options for reporting or visualization of BI data over map. Apart from comparison the framework for implementation of maps into the selected BI tools is established in the above mentioned work.

The aim of the thesis is to define the term Self-service Business Intelligence. It is followed by an introduction of need of this technology in present information society. Thesis at last defines technologies and practices, which are applicable in most general situations. All defined recommendations are based on vast range of theoretical data sources. Second aim is to prove that all customers' requirements can be in specified case covered by functionality of Self-service BI solution. This proof is presented by an introduction of architectural proposal using chosen technological platform. This proposal is furthermore part of bigger elaboration, which by its content loosely follows all tasks present in the initial Case study.

La génération de signaux microondes, millimétriques, voire THz par voie optique est actuellement une solution technique privilégiée pour la réalisation de systèmes de (télé)communications mobiles haut débit mais encore, les réseaux de distribution d'oscillateurs locaux et de signaux d'observation ou de radar intrasatellitaires, la distribution de signaux vidéo, la communication automobile, les systèmes de visualisation THz pour la sécurité, etc… Nous reportons ici la réalisation et la caractérisation d'une source optique ultra-compacte en matériau semiconducteur permettant de générer deux modes optiques séparés de la fréquence que l'on désire créer au niveau de la photodétection. Cette source prend la forme d'un laser DFB bi-longueur d'onde émettant dans la gamme de longueurs d'onde autour de 1,55µm. Le composant a été fabriqué chez Alcatel-Thales III-VLab à partir d'une technologie propriétaire de laser DFB et dans le cade du projet Européen IPHOBAC. Différents objectifs avaient été fixés pour ce composant: accordabilité de l'écartement intermodal jusque 300 GHz, largeur de raie de l'ordre du MHz et divergence dans le plan horizontal et vertical de 10°. Le premier objectif a été atteint par la réalisation de deux lasers DFB dont l'écart de pas de réseau est différent de 0,3nm et par la variation des courants d'injection de chaque section. Le second a été globalement atteint par l'utilisation d'une structure active à puits quantiques, une nouvelle version du composant utilisant des boites quantiques devrait remplir complètement cet objectif. Le dernier objectif a été partiellement atteint par la conception et l'adjonction d'un adaptateur de mode en sortie de composant, la divergence obtenue est de 10°x17° (HxV). Dans le plan vertical, les 10° de divergence n'ont pas pu être obtenus principalement à cause de la structure du composant et des limitations que l'on s'était imposées sur la longueur totale de celui-ci. / Generation of microwave, millimetre-wave even THz signals by optical means is currently a favoured technique for a lot of system applications such as: high bit-rate wireless telecommunications, local oscillator or radar signal distribution within satellites, video signal distribution, automotive communications, THz security systems, etc… We report here the fabrication and the characterization of an ultra-compact optical source made of semiconductor material. It allows generating two optical modes that are separated by the frequency that is requested at the photodetector level. This source is composed of two DFB lasers constituting a dual-mode laser emitting in the 1.55µm wavelength range. The device has been fabricated at Alcatel-Thales III-VLab using a proprietary DFB technology and the work has been supported under the "IPHOBAC" European project. Several targets were fixed for this device: tunability of intermodal spacing up to 300GHz, optical linewidth close to the MHz as well as horizontal and vertical divergences around 10°. The first goal has been achieved by using two DFB structures with a 0.3nm difference in the grating pitch and tuning the drive current of each section. The second goal has been globally achieved by using a quantum well based active layer. A new version including quantum dot based active layer should answer positively to this target. Last objective was partially obtained by the design and the integration of a spot size converter. The divergence has been measured as 10°x17° (HxV). Concerning the vertical divergence, the target of 10° was not obtained mainly linked to the device structure and the limitations we fixed on the overall length of the device.