Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / Nesta dissertação foram estudas rochas máficas dos complexos alcalinos de Morro de São João, Rio Bonito, Tanguá, Gericinó-Mendanha, Morro Redondo, Itatiaia e Passa Quatro. Essas rochas ocorrem na forma de diques e/ou sills. As amostras coletadas foram classificadas como lamprófiros, fonolitos, gabros e diabásios alcalinos. A análise geoquímica permitiu identificar um trend fortemente insaturado e um trend moderadamente alcalino para os complexos estudados. O primeiro é caracterizado por foiditos e fonolitos como membros parentais e mais evoluídos, respectivamente, enquanto o segundo tem basaltos alcalinos como membros parentais e traquitos como os mais evoluídos. Todas as amostras plotam no campo da série alcalina, sendo majoritariamente miaskíticas, sódicas ou potássicas. Adicionalmente, o estudo geoquímico indicou que os complexos alcalinos representam câmaras magmáticas distintas, onde diferentes processos evolutivos tiveram lugar. As modelagens apontaram dois processos de diferenciação distintos nos complexos estudados. Os complexos alcalinos de Morro de São João, Morro Redondo, Gericinó-Mendanha e Itatiaia estariam relacionados a processos de cristalização fracionada. Por outro lado, o Complexo Alcalino de Passa Quatro teria sido diferenciado por processos de cristalização fracionada com esvaziamento e posterior reabastecimento da câmara magmática (RTF). De um modo geral, esses modelos indicaram a presença de mais do que uma série magmática nos complexos estudados e a não cogeneticidade entre as séries agpaíticas e miaskíticas. A discriminação de fontes foi feita com base na análise dos elementos terras raras das amostras parentais de cada um dos complexos (gabro em Morro de São João e lamprófiro nos demais). No entanto, este procedimento não foi aplicado para o Complexo Alcalino de Morro Redondo, uma vez que todas as suas amostras apresentaram valores de MgO muito abaixo do típico para líquidos parentais. O líquido parental do Complexo Alcalino do Gericinó-Mendanha apresentou razões de La/Yb e La/Nb, maior e menor que a unidade, respectivamente, típicas de derivação a partir fontes férteis. Os líquidos parentais dos outros complexos alcalinos tiveram suas razões La/Yb e La/Nb maiores que a unidade, típicas de derivação a partir de fontes enriquecidas. Os modelos desenvolvidos revelaram que os líquidos parentais de cada um dos complexos estudados estariam relacionados a fontes lherzolíticas com granada residual. Além disso, a fusão parcial destas fontes teria ocorrido num intervalo de 1 a 7% dentro da zona da granada. Finalmente, as modelagens petrogenéticas elaboradas permitiram a proposição de um cenário geodinâmico, envolvendo a descompressão adiabática do manto litosférico e sublitosférico anomalamente aquecidos. As características geoquímicas dos líquidos parentais parecem ter sido controladas essencialmente pela mistura desses dois tipos de fontes. / Mafic rocks from the Morro de São João, Rio Bonito, Tanguá, Gericinó-Mendanha, Morro Redondo, Itatiaia and Passa Quatro alkaline complexes were studied based on field, petrographic and lithogeochemical data. The mafic rocks are mostly alkaline lamprophyres and alkaline gabbro (in Morro de São João). The complexes show both strongly undersaturated and mildly alkaline evolutionary trends, having foidites and alkaline basalts as parental compositions. Trachytes and phonolites are the most common evolved rocks. Geochemical modelling has show that miaskitic and agpaitic series are unlikely to be related by fractional crystallization. Enriched mantle sources predominate although a fertile mantle source seems to be related with the Gericinó-Mendanha complex. Parental compositions are related to small amounts of partial melting (1-7%) of garnet lherzolite within the garnet stability field in the mantle. Simple geodynamic models indicate that the alkaline complexes are related to the adiabatic decompression of anomalously hot (~1570C) mantle although unrelated to lithospheric translation over a fixed hotspot or mantle plume. Parental compositions are likely to be strongly controled by mixing of distinctive lithospheric mantle sources and a more homogeneous sublithospheric mantle. The lithospheric components seem to be related with the accreted terranes during the Gondwana amalgamation in Early Proterozoic times.

O resíduo estudado neste trabalho é originado do processo de obtenção de alumínio metálico, de grande interesse no Brasil pelo fato do país ser detentor de algumas das maiores reservas do mineral bauxita no mundo, utilizado como fonte de alumínio. Tendo como estratégia a geração de resíduo zero, colaborando para as tecnologias ambientalmente amigáveis, este trabalho estuda a incorporação de um resíduo resultante da recuperação de alumínio presente na escória gerada durante o processo de produção primária do alumínio metálico, por plasma térmico. Utilizando-se o diagrama de equilíbrio de fases do sistema Al2O3-CaO-SiO2, fez-se a adequação das composições visando a incorporação de resíduo no produto cerâmico sem alterar as características de processamento do material. A obtenção de vidros e de fritas vitrocerâmicas com o resíduo borra branca foi realizada fazendo-se a fusão das composições calculadas e, para os vitrocerâmicos, tratamento térmico posterior de devitrificação. Os produtos obtidos foram caracterizados utilizando-se técnicas de análise tais como difração de raios X (DRX), microscopia eletrônica de varredura (MEV) e espectroscopia do infravermelho (FTIR). Foi possível obter material vitrocerâmico com até 30% de resíduo de alumínio, após a fusão a 1300°C e devitrificação a 900°C. Em adição, o resíduo demonstrou ser um promissor material auxiliar na formação de fases cristalinas em baixos tempos de tratamento térmico. / This work studies the residue obtained from the process of aluminum metal extraction activities, a great interest process, because of Brazil own some of the biggest bauxite mineral reserves in all the world. As a useful choice for no residue generation, and a support for environmentally friendly technologies, this work studies the white dross residue (WDR), from the process of aluminum metal reduction by thermal plasma. The phase equilibrium diagram of Al2O3-Ca O-SiO2 system was used to calculate the compositions. The WDR were incorporated in a ceramic product without modifying its principal characteristics. The fusion and devitrification treatments were studied. XRD (X-ray diffractometry), SEM (scanning electron microscopy) and FTIR (transformed Fourier infrared) were used to investigate the glass and glassceramic samples. These techniques showed that is possible to get glassceramic with up to 30 mass% of WDR after molten at 1300 deg C and annealed at 900 deg C. In addition, the WDR showed to be a promising material in attainment of crystalline phases in less times of heat treatment for annealing.

This work describes advanced fabrication of custom orthopaedic implants using unconventional additive manufacturing technology - Selective Laser Melting (SLM). There was a main focus on custom knee replacement and certainly on its femoral component. The study investigated three general issues within the domain of the usage of additive manufacturing technology in medical application. First, there was an evaluation of process parameters influences of SLM fabrication method on surface and mechanical properties of titanium Ti6Al4V ELI specimens. This material was used because of its biocompatibility and its wide use within implant fabrication. Then, a proposal of the manufacturing strategy was carried out and the fabrication of customized knee femoral component prototype by SLM technology was done. The elaboration of the numerical chain prior the SLM implant fabrication, from patient's CT knee scan to final femoral replacement model, was also done. Then, a proposal of different 3-axis and 5-axis strategies of machining of the fitting femoral surface of bone prototype (3D printed from the powder) using CNC machines FV 25 CNC and TAJMAC ZPS MCV 1210 was projected and also, the 3-axis spiral machining was realised. The individual machining tool paths were generated by software Power Mill from Delcam group. Finally, these machining strategies were generated as a prior step before a machining of real patient’s bone, therefore the machining tests of cartilage and bone were done.

Les procédés de fabrication additive sont aujourd'hui de plus en plus utilisés dans l'industrie. Parmi les différentes technologies existantes, les procédés additifs métalliques, et notamment les procédés en couches, sont les plus prometteurs pour la conception de produits mécaniques. Des travaux ont été menés sur la thématique de la conception de produits réalisés par ces moyens, il traitent principalement du choix du procédé le plus adapté, de l'optimisation de formes ou présentent des cas de reconception. Il n'existe cependant pas de démarche globale de conception de produits qui permettent de prendre en compte les spécificités des procédés additifs en couches, notamment leurs contraintes de fabrication.Lors de ce travail de thèse, les changements que ces procédés introduisent dans le domaine des possibles en conception de produits ont été montrés et illustrés par des pièces réalisées par EBM. De nouvelles opportunités s'offrent au concepteur, comme l'accès à l'ensemble du volume de fabrication, la facilité de réalisation de pièces complexes, la possibilité de réaliser des treillis tridimensionnels et la capacité de produire des mécanismes sans assemblage. Les contraintes de fabrication de ces procédés sont spécifiques. Les phénomènes thermiques lors de la fabrication ont une incidence sur la fabricabilité et la qualité des pièces. La phase de retrait de poudre impose quant à elle des contraintes d'accessibilités. Pour prendre en compte cette évolution, il est nécessaire de concevoir spécifiquement les pièces pour la fabrication additive.Le procédé EBM est au centre du travail réalisé. Il s'agit d'un moyen de fabrication additive en couches, par fusion, à l'aide faisceau d'électrons. Les phénomènes thermiques, qui peuvent causer déformations et mauvaise intégrité de la matière, l'opération de dépoudrage et la problématique de la qualité des pièces fabriquées par EBM ont fait l'objet de caractérisations expérimentales. La durée de fabrication et le coût de revient technique des pièces réalisées par EBM ont également été étudiés, afin d'établir la relation entre durée, coût et géométrie des pièces.Pour de prendre en compte les contraintes explicitées auparavant, et pour bénéficier des importantes libertés que ce procédé offre aux concepteurs, une démarche de conception a été proposée. Cette démarche consiste à générer une ou plusieurs géométries initiales, soit directement par le concepteur, soit par l'utilisation d'outils d'optimisation topologique, à partir de données extraites du cahier des charges. Une fois le balançage de la pièce choisi (en prenant en compte les contraintes de fabrication, le tolérancement de la pièce et la productivité de la fabrication), la pièce est modélisée en incluant un jeu de paramètres pour effectuer une optimisation paramétrique. Cette optimisation permet de dimensionner la pièce, tout en prenant en compte les contraintes de fabrication. A l'issue de cette phase d'optimisation, la géométrie finale est obtenue en prenant en compte les exigences des opérations de parachèvement éventuelles et en définissant les supports, s'ils sont nécessaires. Cette démarche a été illustrée par la reconception de deux pièces mécaniques qui répondent aux exigences de leur cahier des charges fonctionnel, sont fabricables à l'aide du procédé EBM et offrent des gains de masse importants.Enfin, un chapitre particulier est consacré aux perspectives mises en évidence (et ayant parfois fait l'objet de travaux préliminaires) à l'occasion de ce travail de thèse. / Nowadays, the use of Additive Manufacturing processes keeps growing in the industry. Among the numerous kinds of AM processes, metallic additive manufacturing processes, and metallic Additive Layer Manufacturing in particular, are the most interesting from a mechanical designer point of view. Several research studies have been conducted on the topic of Design For Additive Manufacturing, mostly discussing the choice of AM processes or presenting the redesign of parts. There is no specific design methodology for ALM processes that takes their specificities into account.During this PhD thesis, the changes that ALM processes bring to the design space were investigated. The designer has the opportunity to easily manufacture thin parts, complex parts, lattice structures or mechanisms that don't need any assembly. These processes also have specific manufacturing constraints compared to conventional processes. The heat dissipation is the most important factor since it can cause distortions and porosities. Powder removal, surface and geometrical quality also need to be considered during design. A specific design for additive manufacturing methodology is necessary to take these changes into account.This work focuses on the Electron Beam Manufacturing process. Experiments were conducted and analyzed to assess the manufacturability regarding the thermal phenomena (during melting), the powder removal and the quality of the parts produced by EBM. The impact of the part geometry on manufacturing duration and manufacturing cost was also established.In order to use allow designers to use these pieces of information, we suggested a designing methodology. From the requirements of the parts, one or several parts are generated by the designer or by using topological optimization tools. The orientation of the part inside the manufacturing space is set before designing a refined parametric geometry. This parametric geometry is optimized in order to meet the user requirements as well as the EBM requirements. The last step is the modification of the geometry to comply with the finishing operations (machining allowances for example) and the placement of supports, if needed. This methodology was illustrated with the redesign of two example parts and showed important mass savings from the parts (while meeting user and process requirements).The prospects discovered and highlighted during this work, some of which were preliminary investigated, are presented in a specific chapter.

Ce travail de thèse considère les modes de déformations des verres métalliques produits sous différentes formes (verres massifs, rubans et particules). La déformation hétérogène dans des échantillons massifs de verres métalliques à base de zirconium est étudiée par microscopie électronique à balayage. Le dégagement rapide de l'énergie élastique stockée sous forme de chaleur lors de la déformation est responsable de la fusion locale observée dans les bandes de cisaillement. Le calcul du profil de température autour d'une bande par un modèle analytique est cohérent avec les observations morphologiques et les rapports d'apparition de nano-cristaux dans la zone déformée. La mise en forme par recuit des rubans de verres métalliques a été étudiée. L'étude aboutit à la mise en forme sans fragilisation des rubans appartenant à différentes compositions de systèmes d'alliages dit métal-métal et métal-métalloïde. Un processus de traitement thermique est suggéré pour assurer la redistribution des contraintes imposées avant l'intervention de la fragilité thermique. Un brevet industriel basé sur ces résultats a été conjointement déposé avec un grand fabriquant de montres mécaniques. De nouveaux matériaux composites d'alliages légers commerciaux à base de Mg et d'Al renforcés par des dispersions de particules de verres métalliques ont été réalisés sans porosité. Une amélioration très nette des propriétés mécaniques est obtenue. / This thesis features the two modes of deformation of metallic glasses produced under different forms (bulk, ribbons and particles). Inhomogeneous deformation in bulk samples is studied by scanning electron microscopy. Heat generated by elastic energy release during deformation is responsible for the melting observed in shear bands, and calculations using an analytical model of the temperature profile around a band are consistent with morphological observations and reports of appearance of nano-crystals in or next to deformed areas. Shaping by annealing glassy ribbons was carried out. The study presents successful shaping without embrittlement of ribbons of different metal-metal and metal-metalloid compositions of glassy systems. A heat treatment process is suggested for redistribution of applied stresses before the intervention of thermal embrittlement. A joint patent for exploiting the findings has been filed with a major producer of mechanical watches. Development of new strong and light composite materials by dispersing glassy particles in aluminum and magnesium based matrices is presented and significant improvement in mechanical properties is obtained.

[pt] O conhecimento organizacional, ou capital intelectual, é hoje reconhecido como o fator fundamental não só para o crescimento, como para a própria sobrevivência das organizações em ambientes dinâmicos, turbulentos, incertos, altamente inovadores e competitivos, como os do presente contexto de economias crescentemente globalizadas. A gestão do conhecimento organizacional (KM) apresenta-se, então, como uma das condições necessárias ao sucesso de estratégias competitivas, embora, por certo, não suficiente, sendo a demanda de conhecimento externo existente, por meio de negócios de fusão e aquisição (M&A), reconhecida como um dos processos essenciais da gestão, alternativamente a procedimentos inovadores em P&D, em geral lentos e onerosos. Todavia, pesquisas têm comprovado que, mundialmente, apenas cerca de 30% dos casos de M&A têm alcançado sucesso em seus objetivos estratégicos. Não obstante, esse tipo de negócio tem se afigurado como essencial à expansão de empresas de classe mundial, dada a insuficiência do mero crescimento orgânico, o que constitui um paradoxo. Este estudo de caso teve por objetivo descrever e explicar as causas do fenômeno do insucesso no desempenho da estratégia da empresa Xerox|MHW, combinada em processo de aquisição, tendo como componente essencial a gestão do conhecimento. A literatura examinada para a compreensão dos conceitos básicos pertinentes contemplou tópicos sobre padrões organizacionais; estratégias de organizações; conhecimento organizacional e sua gestão e resultados de processos de fusão e aquisição de empresas. A coleta de evidências, adotando procedimentos de triangulação, foi realizada a partir de documentos, entrevistas e duas pesquisas, visando, a segunda, validar os dados coletados anteriormente. Com base no modelo integrativo-sistêmico GI de MACEDO-SOARES (2000), a realidade revelada pela pesquisa mostrou-se contraditória relativamente aos requisitos, pressupostos e suposições implícitos na formulação estratégica, resultando, daí, a sua não-adequação ao desempenho da organização na busca de seu objetivo estratégico. A conclusão é que um processo de aquisição está longe de ser algo trivial, sendo os problemas de não- integração organizacional, principalmente cultural, em casos de aquisição por escopo, em particular envolvendo uma grande empresa burocrática e uma pequena empresa de padrão organizacional flexível, os grandes responsáveis por esse elevado percentual. Quanto ao conhecimento organizacional, evidenciou-se que não basta a uma organização entendê-lo como um recurso essencial no contexto de negócios atual. É imprescindível a implementação de procedimentos e práticas para a sua gestão, não obstante constituir processo recente e complexo que requer, até por isso mesmo, efetivo apoio da alta administração das organizações e o desenvolvimento de uma cultura adequada à sua efetivação. / [en] Organizational knowledge, or intellectual capital, is nowadays recognized as a key factor not only for growth, but for survival of organizations in dynamic, disturbed, uncertain and highly innovative and competitive environments, such as the ones in the current scenario of rising global economies. Organizational knowledge management (KM) is introduced, therefore, as one of the necessary conditions for competitive strategies success. However, of course, it is not enough, and the need for external knowledge, through merger and acquisition (M&A), is recognized as an essential management process, an alternative for innovative P&D procedure, normally slow and burdensome. Anyway, researches have assured that, worldwide, only 30% of M&A cases have reached success in their business goals. Nevertheless, this kind of business have been considered essential for the expansion of worldwide companies, since mere organic growth is insufficient, which is a paradox. This case study aims to describe and explain the causes for the failure phenomena in Xerox|MHW company strategy performance, combined when Xerox acquired MHW, with knowledge management as its key component. The literature consulted to comprehend these basic concerning concepts encompasses topics about organizational models, strategies, knowledge management and results of company merger and acquisition processes. The gathering of evidences, adopting triangulation procedures, has been performed using documents, interviews and two surveys. The second survey aimed to validate the data collected previously. Based on MACEDO-SOARES (2000) GI systemic-integrative model, the reality revealed by the research is contradictory in relation to the requirements, presuppositions and suppositions implicit in the strategy conception, resulting, from this, its nonadjustment to the organization performance, trying to pursuit its strategic objective. The conclusion is that an acquisition process is far from being something trivial, and the problems of organizational non- adjustment - mainly cultural, in cases of scope acquisition, particularly involving a major bureaucratic company and a minor one with flexible organization model - are the responsible factors for this high percentage. About organizational knowledge, it is clear that understanding it as an essential resource in the current business scenario is not enough. It is crucial the implementation of practices and procedures to its management. However, building this new and complex process requires, because of it, solid support from high level management in the companies and the development of a proper culture, fitting its accomplishment.

Le systeme bidimensionnel etudié dans cette thèse est un film de Langmuir, film constitué d'une unique couche de molécules amphiphiles à l'interface eau-air. Une transition du premier ordre, observée dans une monocouche d'acide NBD-stéarique révèle la coexistence entre une phase cristalline et une phase liquide. Les domaines monocristallins se présentent sous la forme de longs bâtonnets, parfaitement adaptés aux études mécaniques. Nous étudions certaines propriétés de ce cristal bidimensionnel. La première étude concerne la rupture de ce solide bidimensionnel. Un cristal maintenu fléchi dans le plan de l'eau se rompt après une durée bien déterminée. Cette durée s'est avérée être fonction de la déformation appliquée au cristal. A fortescontraintes, on second mode de rupture coexiste : un certains nombre de cristaux cassent intantanément tandis que d'autres présentent une rupture différée. La seconde étude s'intéresse à la fusion des cristaux en équilibre avec leur phase liquide. La fusion peut être provoquée par trois processus distincts : deux processus thermodynamiques (réchauffement et décompression) et un processus photochimique. Ce dernier s'est avéré dû à une réaction photochimique réversible avec l'oxygène de l'air, conduisant a l'abaissement du point de fusion du cristal. Les trois processus de fusion conduisent à des observations similaires, indiquant ainsi l'existence d'un mécanisme commun dans l'initiation de la fusion. Les observation montrent que l'intérieur du crystal fond bien avant ses bords. De plus, la fusion d'un cristal maintenu déformé a lieu le long d'une ligne ou la contrainte s'annule. Nous suggérons que le mécanisme responsable de ce phénomène est la migration de défauts, probablement des dislocations, à l'endoit du cristal non déformé.; Ces défauts jouant le rôle de centres de nucléation de la fusion. Ces résultats montrent le rôle primordial des défauts dans la fusion à deux dimension.

<p>We have studied the critical properties of three-dimensional U(1)-symmetric lattice gauge theories. The models apply to various physical systems such as insulating phases of strongly correlated electron systems as well as superconducting and superfluid states of liquid metallic hydrogen under extreme pressures. This thesis contains an introductory part and a collection of research papers of which seven are published works and one is submitted for publication.</p><p>Paper I: Critical properties of the 2+1-dimensional compact abelian Higgs model with gauge charge q=2 are studied. We introduce a novel method of computing the third moment M₃ of the action which allows us to extract correlation length and specific heat critical exponents ν and α without invoking hyperscaling. Finite-size scaling analysis of M₃ yields the ratio (1+α)/ν and 1/ν separately. We find that α and ν vary along the critical line of the theory, which however exhibits a remarkable resilience of Z₂ criticality. We conclude that the model is a fixed-line theory, which we propose to characterize the zero temperature quantum phase transition from a Mott-Hubbard insulator to a charge fractionalized insulator in two spatial dimensions.</p><p>Paper II: Large scale Monte Carlo simulations are employed to study phase transitions in the three-dimensional compact abelian Higgs model in adjoint representations of the matter field, labeled by an integer q, for q=2,3,4,5. We also study various limiting cases of the model, such as the Z_q lattice gauge theory, dual to the 3DZ_q spin model, and the 3D xy spin model which is dual to the Z_q lattice gauge theory in the limit q → ∞. In addition, for benchmark purposes, we study the 2D square lattice 8-vertex model, which is exactly solvable and features non-universal critical exponents. The critical exponents α and ν are calculated from finite size scaling of the third moment of the action, and the method is tested thoroughly on models with known values for these exponents. We have found that for q=3, the three-dimensional compact abelian Higgs model exhibits a second order phase transition line which joins a first order phase transition line at a tricritical point. The results for q=2 in Paper I are reported with a higher lever of detail.</p><p>Paper III: This paper is based on a talk by F. S. Nogueira in the Aachen HEP 2003 conference where a review of the results for the compact abelian Higgs model from Paper I and Paper II was presented, as well as the results for the q=1 case studied by F. S. Nogueira, H. Kleinert and A. Sudbø.</p><p>Paper IV: We study the effects of a Chern-Simons (CS) term in the phase structure of two different abelian gauge theories in three dimensions. By duality transformations we show how the compact U(1) gauge theory with a CS term for certain values of the CS coupling can be written as a gas of vortex loops interacting through steric repulsion. This theory is known to exhibit a phase transition governed by proliferation of vortex loops. We also employ Monte Carlo simulations to study the non-compact U(1) abelian Higgs model with a CS term. Finite size scaling of the third moment of the action yields critical exponents α and ν that vary continuously with the strength of the CS term, and a comparison with available analytical results is made.</p><p>Paper V: The critical properties of N-component Ginzburg-Landau theory are studied in d=2+1 dimensions. The model is dualized to a theory of N vortex fields interacting through a Coulomb and a screened potential. The model with N=2 shows two anomalies in the specific heat. From Monte Carlo simulations we calculate the critical exponents α and ν and the mass of the gauge field. We conclude that one anomaly corresponds to an inverted 3D xy fixed point, while the other corresponds to a 3D xy fixed point. There are N fixed points, namely one corresponding to an inverted 3D xy fixed point, and N-1corresponding to neutral 3D xy fixed points. Applications are briefly discussed.</p><p>Paper VI: The phase diagram and critical properties of the N-component London superconductor are studied both analytically and through large-scale Monte-Carlo simulations in d=2+1 dimensions. The model with different bare phase stiffnesses for each flavor is a model of superconductivity which should arise out of metallic phases of light atoms under extreme pressure. A projected mixture of electronic and protonic condensates in liquid metallic hydrogen under extreme pressure is the simplest example, corresponding to N=2 with individually conserved matter fields. We compute critical exponents α and ν for N=2 and N=3. The results from Paper V are presented at a higher level of detail. For the arbitrary N case, there are N fixed points,namely one charged inverted 3D xy fixed point, and N-1 neutral 3D xy fixed points. We explicitly identify one charged vortex mode and N-1 neutral vortex modes. The model for N=2 and equal bare phase stiffnesses corresponds to a field theoretical description of an easy-plane quantum antiferromagnet. In this case, the critical exponents are computed and found to be non 3D xy values. Furthermore, we study the model in an external magnetic field, and find a novel feature, namely N-1 superfluid phases arising out of N charged condensates. In particular, for N=2 we point out the possibility of two novel types of field-induced phase transitions in ordered quantum fluids: i) A phase transition from a superconductor to a superfluid or vice versa, driven by tuning an external magnetic field. This identifies the superconducting phase of liquid metallic hydrogen as a novel quantum fluid. ii) A phase transition corresponding to a quantum fluid analogue of sublattice melting, where a composite field-induced Abrikosov vortex lattice is decomposed and disorders the phases of the constituent condensate with lowest bare phase stiffness. Both transitions belong to the 3D xy universality class.</p><p>Paper VII: We consider the vortex superconductor with two individually conserved condensates in a finite magnetic field. The ground state is a lattice of cocentered vortices in both order parameters. We find two novel phase transitions when temperature is increased at fixed magnetic field. i) A "vortex sublattice melting" transition where vortices in the field with lowest phase stiffness ("light vortices") loose cocentricity with the vortices with large phase stiffness ("heavy vortices"), entering a liquid state (the structure factor of the light vortex sublattice vanishes continuously.) This transition is in the 3D xy universality class. ii) A first order melting transition of the lattice of heavy vortices in a liquid of light vortices.</p><p>Paper VIII: We report on large-scale Monte Carlo simulations of a novel type of a vortex matter phase transition which should take place in a three dimensional two-component superconductor. We identify the regime where first, at a certain temperature a field-induced lattice of co-centered vortices of both order parameters melts, causing the system to loose superconductivity. In this state the two-gap system retains a broken composite symmetry and we observe that at a higher temperature it undergoes an extra phase transition where the disordered composite one-flux-quantum vortex lines are "ionized" into a "plasma" of constituent fractional flux vortex lines in individual order parameters. This is the hallmark of the superconductor-to-superfluid-to-normal fluid phase transitions projected to occur in e.g. liquid metallic hydrogen.</p>

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