Flash processing is a new heat treatment process being developed to produce steel with relatively high strength and ductility. It involves rapidly heating steel sheet or strip to a temperature in the austenite range and quenching; the entire thermal cycle takes place within 15 seconds. The resulting microstructure is fine and difficult to resolve using standard metallographic techniques. In this investigation, electron backscatter diffraction was used to measure the grain size, grain orientations, and phase fractions in AISI 8620 samples flash processed to a series of different maximum temperatures. The combination of high strength with moderate ductility obtained by flash processing arises from a refined martensitic microstructure. The morphology of the microstructure depends upon the maximum processing temperature; a lower maximum temperature appears to produce a finer prior austenite grain size and an equiaxed martensite structure whereas a higher maximum processing temperature yields a more conventional lath martensite morphology. / Master of Science

Magíster en Tecnologías de la Información / La administración de cuentas de acceso en los sistemas y recursos TI (Tecnologías de Información) es una actividad compleja y costosa que actualmente preocupan a las grandes empresas. El problema radica principalmente en la coexistencia de múltiples fuentes de registros de usuario, cada uno de estos con diferentes formatos, estándares y objetivos, enfocados a responder a las necesidades de negocio particulares. Por otra parte, la presencia de numerosos sistemas heterogéneos demanda un sobreesfuerzo por parte del equipo de soporte, con lo que no se pudo garantizar que las cuentas de acceso fueran creadas o eliminadas en el momento adecuado. Todo esto, tiene como consecuencia un incremento en los costos de administración, disminuyendo la productividad de los equipo de soporte encargados de esta actividad. La empresa Telefónica se hace cargo de esta realidad, adquiriendo un Sistema de Gestión de Identidad (IDM) de llamado Oracle Identity Manager (OIM). Lamentablemente, al integrar OIM a la compañía, se provocaron problemas de interoperabilidad, dado a que módulos de conexión de esta plataforma fueron ineficientes y poco amigables para manejar las inconsistencias de las fuentes autoritativas de identidad (repositorios de registros de usuario) y en la reutilización de componentes al conectarse con los diferentes recursos TI de la empresa. A razón de esto, la presente tesis de grado, tiene por objetivo construir un Middleware que estandarice y agilice la integración de OIM tanto con los servicios de usuarios como con las aplicaciones de la empresa. Como resultado de este trabajo, se obtiene una aplicación web en donde se presenta información tanto de usuarios como recursos en cuanto a aspectos de seguridad y auditoría. Para esto, también se dispone una Fuente Única Autoritativa de Identidad donde se concentraron todos los registros de usuarios. Finalmente, se provee un medio único de autentificación para todos los sistemas que se integren a esta Plataforma de Gestión de Identidad.

Uppsatsen tar avstamp i de ökade krav om samhällsansvar som ställs på företag. Kravenresulterar i att företagen antingen tar större ansvar eller framställer sig som att de tar störreansvar. Problematiken som uppsatsen adresserar är följaktligen svårigheten i att avgörahur pass hållbara företag egentligen är, om de externa hållbarhetsredovisningarna ärvinklade i syfte att öka läsarens tro att företaget arbetar hållbart. Syftet med uppsatsen äratt undersöka likheter och skillnader i hur företag som anses hållbara respektive ickehållbaraskapar intryck av ett hållbart företagande i sina hållbarhetsredovisningar. Tvåhållbarhetsredovisningar från hållbara företag och två från icke-hållbara företagundersöktes utifrån teorin om impression management. Undersökningen bestod av tvådelar, där den ena innebar en mätning av fyra impression management taktiker och denandra en öppen ansats där fokus låg på att studera visuell information samt löpande text.Undersökningen gav att både de hållbara och de icke-hållbara företag använderimpression management i sina hållbarhetsredovisningar, men att de icke-hållbaraföretagen använder fler och i vissa fall mer aggressiva former.

A method for the retrieval of grain boundary inclination parameters of the grain boundary character distribution by oblique double-sectioning is proposed. The method, which is similar to the recovery of the orientation distributions from sets of incomplete pole-figures, is described along with a framework for implementation. The method directly measures grain boundary inclinations in a manner similar to serial sectioning while statistically sampling the microstructure comparably to stereological methods. Computer simulations of the method were used to confirm the mathematical framework. Additional simulations, where the grain boundary normal distributions were recovered by both oblique double-sectioning and stereological methods, showed that results recovered by 3 orthogonal double-sections from oblique double-sectioning proved to be just as accurate as the 25 section-cuts required for stereology in resolving the finer details in the recovered distribution.

Advanced high strength steels (AHSS) have high susceptibility to hydrogen embrittlement, and are often exposed to hydrogen environments in processing. In order to study the embrittlement and recovery of steel, tensile tests were conducted on two different types of AHSS over time after hydrogen charging. Concentration measurements and hydrogen microprinting were carried out at the same time steps to visualize the hydrogen behavior during recovery. The diffusible hydrogen concentration was found to decay exponentially, and equations were found for the two types of steel. Hydrogen concentration decay rates were calculated to be -0.355 /hr in TBF steel, and -0.225 /hr in DP. Hydrogen concentration thresholds for embrittlement were found to be 1.04 mL/100 g for TBF steel, and 0.87 mL/100g for DP steel. TBF steel is predicted to recover from embrittlement within 4.1 hours, compared to 7.2 hours in DP steel. A two-factor method of evaluating recovery from embrittlement, requiring hydrogen concentration threshold and decay rate, is explained for use in predicting recovery after exposure to hydrogen. Anisotropic hydrogen diffusion rates were also observed on the surface of both steels for a short time after charging, as hydrogen left the surface through <001> and <101> grains faster than grains with <111> orientations. This could be explained by differences in surface energies between the different orientations.

Microstructure changes that occur during the deformation and heat treatments involved in wrought processing of metals are of central importance in achieving the desired properties or performance characteristics in the finished products. However, thorough understanding of the evolution of microstructure during thermo-mechanical processing of metallic materials is largely hampered by lack of methods for characterizing reliably their local (anisotropic) properties at the sub-micron length scales. Recently, remarkable advances in nanoindentation data analysis techniques have been made which now make it possible to obtain quantitative information about the local mechanical properties of constituent individual grains in polycrystalline metallic samples. In this work, a novel approach that combines mechanical property information obtained from spherical nanoindentation with the complementary structure information measured locally at the indentation site, using Electron Backscattered Diffraction (EBSD), is used to systematically investigate the local structure-property relationships in fcc metals. This work is focused on obtaining insights into the changes in local stored energies of polycrystalline metallic samples as a function of their crystal orientation at increasing deformation levels. Furthermore, using the same approach, the evolution of mechanical properties in the grain boundary regions in these samples is studied in order to better understand the role of such interfaces during deformation and recrystallization processes. The findings provide valuable information regarding development of stored energy gradients in polycrystalline materials during macroscopic deformation.

Le retour volontaire est une pratique d’éloignement qui a la particularité de s’appuyer sur la« volonté » des migrants, ou tout du moins, sur leur participation au processus de retour. Cetteambiguïté ne se révèle analytiquement féconde, qu’à condition de dépasser les schèmesdichotomiques d’appréhension des relations de pouvoir que renferme le retour volontaire. C’està cet effort de conceptualisation que nous invitent les migrants ouest et centre africains quis’engagent, depuis le Maroc, dans une procédure d’ « Aide au Retour Volontaire et à laRéintégration » (AVRR) diligentée par l’Organisation Internationale pour les Migrations(OIM). Selon la formule consacrée par les candidats au retour sur le terrain marocain, s’inscrireà l’OIM revient à « signer la déportation ». À travers cette expression émique, ils et ellesrévèlent dans quelle mesure épreuve de la violence et manifestation de l’agencéité tendent à seconfondre dans l’expérience du retour volontaire.La dialectique du contrôle et de l’agencéité cependant, ne constitue qu’une étape de la réflexionpermettant d’appréhender avec rigueur la participation des migrants à l’éloignement. En effet,l’ethnographie des retours volontaires démontre qu’entre la violence des frontières et la capacitéd’action des migrants, se trouvent des acteurs hétérogènes – humanitaires, caritatifs etassociatifs – qui jouent un rôle intermédiaire dans la mise en retour des migrants. C’est danscet espace médian que se joue la part d’indétermination, non seulement de l’issue, maiségalement des modalités du processus de retour volontaire. L’intermédiation constitue dans cesens un espace relationnel où convergent, se contestent et se déforment l’un l’autre, lesmécanismes d’éloignement et les expressions de l’agencéité migrante.En somme, ni tout à fait réductible à une forme d’expulsion, ni exclusivement synonyme d’uneliberté d’action des migrants, la participation des migrants au retour volontaire se façonne àpartir de trois pôles en tension :la violence, l’intermédiation et l’agencéité migrante. / Doctorat en Sciences politiques et sociales / info:eu-repo/semantics/nonPublished

Approved for public release, distribution is unlimited / This study evaluated dome test samples of a superplastic AA5083 aluminum alloy deformed at nominally constant strain rates under biaxial strain conditions. Dome test samples resulted from gas-pressure forming of sheet material; for this study, samples were deformed at strain rates corresponding either to grain boundary sliding or dislocation creep control of deformation. Orientation Imaging Microscopy was utilized to determine texture development, grain size and grain-to-grain misorientation angle distributions for locations located along a line of latitude of the dome samples. The goal was to identify the location of the transition from grain boundary sliding to dislocation creep. Grain boundary sliding, which dominates at lower strain rates, can be recognized by a randomized texture and a higher concentration of high disorientation angles. Dislocation creep, which dominates at higher strain rates, is characterized by fiber texture formation and development of a peak at lower angles in the grain-to-grain misorientation angle distribution. / Ensign, United States Navy

Le gouvernement international des frontières d’Asie centrale (Kirghizstan, Tadjikistan, Ouzbékistan, Kazakhstan, Turkménistan) comprend les projets de gestion des frontières conduits par l’OSCE, la Commission européenne, l’ONUDC et l’OIM entre 1992 et 2012. Ils organisent l’import/export d’une expertise alignant les limites étatiques dans cette région sur un double impératif de mobilité et de sécurité. Comment ces savoirs sur la frontière circulent-ils à travers ces dernières ? Les projets passent par trois univers distincts. Ils prennent attache sur les sociétés centrasiatiques aux intersections entre flux et contrôle. Les équipements qu’ils fournissent n’encadrent toutefois les pratiques de vérification que dans une mesure très variable. Ces investissements sont décidés dans des comités de pilotage situés dans un microcosme qu’on appelle le champ d’opérations. Cet espace se configure selon un capital dont le volume décrit l’autonomie des opérateurs, et dont la structure signale leur niveau de spécialisation dans les mondes du développement et de la sécurité. Sa structure sanctionne positivement les acteurs qui accumulent la plus grande quantité de capital social. Les enceintes d’autorisation sont quant à elles encastrées dans un espace transnational gravitant autour de Bruxelles et de Vienne. Tandis que l’Asie centrale est construite comme un enjeu d’intérêt secondaire au sein du champ de l’Eurocratie, les acteurs de la place viennoise lui accordent une importance plus grande. Les élites transnationales les plus subalternes sont incitées à s’établir dans cette zone de relégation, car elles peuvent plus facilement y rétablir leurs positions respectives. / The international government of Central Asian Borders (Kyrgyzstan, Tajikistan, Uzbekistan, Kazakhstan, Turkmenistan) refers to projects in the field of border management that have been implemented by the OSCE, the European Commission, the UNODC and IOM between 1992 and 2012. These activities import and export a type of expertise aimed at bringing state boundaries in line with an imperative of mobility and security. But how does this border knowledge circulate across borders in the first place? During their life cycle, projects go through three different social universes. Firstly, they connect with Central Asian societies where control and flows intersect. They provide some equipment which only frames checks and controls to some extent. The steering committees deciding over these investments are embedded in a particular social universe that we call the field of operation. This second space is configured according to a capital whose volume corresponds to the level of autonomy that each implementing agency holds, and whose structure refers to their specialization in development and/or security. The practical logic of this field positively sanctions the accumulation of social capital by individual brokers. The authorization-giving arenas, finally, are situated in a transnational space polarized around Brussels and Vienna. Whilst Central Asia is constructed as a place of secondary interest within the field of Eurocracy, actors working from Vienna perceive this region as a more important issue. Subaltern transnational elites tend establish themselves in such unattractive areas because they gain leeway where they can re-establish themselves as important players from there.

Crystalline films of vanadium dioxide were obtained through thermal annealing of amorphous vanadium dioxide thin films sputtered on silicon dioxide. An annealing process was found that yielded polycrystalline vanadium dioxide thin films, semi-continuous thin films, and films of isolated single-crystal particles. Orientation Imaging Microscopy (OIM) was used to characterize and study the phase and the orientation of the vanadium dioxide crystals obtained, as well as to diferentiate them from other vanadium oxide stoichiometries that may have formed during the annealing process. There was no evidence of any other vanadium oxides present in the prepared samples. Indexing of the crystals for the orientation study was performed with the Kikuchi patterns for the tetragonal phase of vanadium dioxide, since it was observed that the Kikuchi patterns for the monoclinic and tetragonal phases of vanadium dioxide are indistinguishable by OIM. It was found that a particle size of 100 nm was in the lower limit of particles that could be reliably characterized with this technique. It was also found that all VO2 crystals large enough to be indexed by OIM had a preferred orientation with the C axis of the tetragonal phase parallel to the plane of the specimen.