Thesis (Ph. D.)--Dept. of History and School of Education. University of Missouri--Kansas City, 2004. / "A dissertation in history and urban leadership and policy studies in education." Advisor: Louis W. Potts. Typescript. Vita. Title from "catalog record" of the print edition Description based on contents viewed Feb. 22, 2006. Includes bibliographical references (leaves 363-372). Online version of the print edition.

Thesis (Ph. D.)--Dept. of Geosciences and Social Science Consortium. University of Missouri--Kansas City, 2004. / "A dissertation in geosciences and Social Science Consortium." Advisor: Wei Ji. Typescript. Vita. Title from "catalog record" of the print edition Description based on contents viewed Feb. 28, 2006. Includes bibliographical references (leaves 118-125). Online version of the print edition.

VAZ,G.L. O. Eletrodeposição, Caracterização e Estudos de Corrosão de Revestimentos de Ni-Mo e Ni-W 2007. 85 f. Dissertação (Mestrado em Ciências) – Centro de Ciências , Universidade Federal do Ceará, Fortaleza, 2007. / Submitted by irlana araujo (irlanaaraujo@gmail.com) on 2011-12-14T18:55:54Z No. of bitstreams: 1 2007dis_Gust_Vaz.pdf: 5262736 bytes, checksum: 7e10de74f24375b9e91a9301ceb635b7 (MD5) / Approved for entry into archive by Aline Nascimento(vieiraaline@yahoo.com.br) on 2011-12-19T14:50:29Z (GMT) No. of bitstreams: 1 2007dis_Gust_Vaz.pdf: 5262736 bytes, checksum: 7e10de74f24375b9e91a9301ceb635b7 (MD5) / Made available in DSpace on 2011-12-19T14:50:29Z (GMT). No. of bitstreams: 1 2007dis_Gust_Vaz.pdf: 5262736 bytes, checksum: 7e10de74f24375b9e91a9301ceb635b7 (MD5) Previous issue date: 2007-02-05 / The corrosion behavior and mechanical properties of Ni-Mo and Ni-W electrocoatings in NaCl solutions are investigated in this work. A comparative study has been done with the properties of Cr. All electrocoatings were obtained under galvanostatic control at room temperature and were evaluated in terms of composition, microstructure, microhardness, cristalinity and corrosion resistance. The surface morphology was characterized by scanning electron microscopy (SEM), the chemical composition was determined by energy dispersive X-rays (EDX), the microhardness was measured by the Vickers hardness test and the structure was determined by X-ray diffraction (DRX). The electrochemical corrosion tests were carried out by linear potenciodinamic polarization (PP) and electrochemical impedance spectroscopy (EIS). The results showed that Ni-Mo and Ni-W present good corrosion resistance when compared with Cr coatings, and the best were Ni-13Mo and Ni-14W. The layer’s micrographs present homogeneous layers with nodules distributed in the surface and cracks can be observed to Ni-17Mo and Ni-25Mo. Ni-Mo and Ni-W coatings are crystalline exhibiting a face-centred-cubic structure in the solid solution. The microhardness increased with the Mo or W percentage and heat treatments increased the hardness of the coatings, while Cr decreased its hardness with heat treatment. / O comportamento da corrosão e as propriedades mecânicas de revestimentos de Ni-Mo e Ni-W em soluções de NaCl foram investigados neste trabalho, sendo feito um estudo comparativo com as propriedades do revestimento de cromo industrial. Todas as camadas foram obtidas sob controle galvanostático em temperatura ambiente e foram avaliadas em termos de composição química, microestrutura, icrodureza, cristalinidade e resistência à corrosão. A morfologia superficial foi caracterizada por microscopia de varredura eletrônica (MEV), a composição química foi determinada por energia dispersiva de raios X (EDX), a microdureza foi medida pelo teste de dureza de Vickers e a estrutura cristalina foi determinada por difração de raios X (DRX). Os testes eletroquímicos de corrosão foram realizados por polarização potenciodinâmica linear (PP) e pela espectroscopia de impedância eletroquímica (EIE). Os resultados mostraram que os revestimentos de Ni-Mo e Ni-W apresentam boa resistência à corrosão quando comparados com os revestimentos de Cr, sendo os melhores Ni-13Mo e Ni-14W. As camadas foram homogêneas, com nódulos distribuídos na superfície e a presença de trincas para as camadas Ni-17Mo e Ni-25Mo. Os revestimentos apresentam uma estrutura cristalina do tipo cúbica de face centrada com a formação de uma solução sólida. A microdureza aumentou com o percentual de Mo e W na camada e com o tratamento térmico a dureza das ligas aumentaram, enquanto as camadas de Cr diminuíram sua dureza com o tratamento térmico.

Made available in DSpace on 2016-08-29T15:38:48Z (GMT). No. of bitstreams: 1 tese_8527_Dissertação - Luciana Altoé.pdf: 1951389 bytes, checksum: 771cdbdb6f110ca88f6253a91aab573a (MD5) Previous issue date: 2016-03-30 / Pesquisas têm apontado que a exposição ao metal pesado arsênio, um contaminante ambiental, pode resultar em efeitos tóxicos, agudos ou crônicos, ocasionando diferentes patologias, inclusive podendo levar a danos na fertilidade masculina. Substâncias com potencial ação protetora vêm sendo investigadas. Entre elas estão o zinco e a vitamina C, ambas com conhecida ação antioxidante, sendo cofatores da divisão celular e exercendo importante papel na reprodução. O objetivo do presente estudo foi avaliar a função testicular de ratos expostos ao arsênio, na forma de arsenito de sódio, e o possível papel protetor da administração concomitante de zinco ou da vitamina C através da realização de análises seminais, biométricas e morfológicas (morfometria e estereologia) do testículo. Ratos Wistar (60 dias de idade) foram divididos em seis grupos, com seis animais cada: (1) controle (água destilada), (2) arsenito de sódio (5 mg/kg/dia), (3) vitamina C (100 mg/kg/dia), (4) cloreto de zinco (20 mg/kg/dia), (5) arsenito de sódio e vitamina C e (6) arsenito de sódio e cloreto de zinco. A administração das dosagens foi realizada diariamente por gavagem, durante 60 dias. Ao final do período de tratamento, os animais foram eutanasiados, os testículos e órgãos acessórios foram coletados e pesados e fragmentos do ducto deferente foram coletados para análises seminais. Em seguida, fragmentos de testículos foram processados para análise em microscopia de luz. Não foram observadas alterações significativas na biometria dos animais tratados, porém alterações nas células de Leydig e nos túbulos seminíferos foram notadas. O arsênio reduziu o diâmetro dos túbulos seminíferos e a altura do epitélio germinativo, resultando em um menor número de espermátides por grama de testículo. A vitamina C e o zinco foram capazes de proteger as células de Leydig e a proporção de espermatozoides normais dos efeitos do arsênio. Conclui-se que a exposição crônica ao arsenito de sódio altera o processo espermatogênico, reduzindo o número total de espermatozoides normais, o que pode levar redução da fertilidade em ratos e que a administração concomitante de zinco ou vitamina C mesmo não sendo capaz de neutralizar o dano numérico levou ao aumento da proporção de espermatozoides normais. Palavras chave: metal pesado, sistema reprodutor masculino, antioxidante, morfometria.

This thesis consists of an annotated translation, with introduction, of the first two of the ten rolls of the Mo-ho-chih-kuan The Mo-ho-chih-kuan is no. 1911 of the works contained in the Taisho edition of the Chinese Buddhist canon (Taisho-shinshu-daizokyo in Vol. 46 from page 1 to page 140. The first two rolls, Chapter One of the whole work, run from page 1 to page 21. The Mo-ho-chih-kuan derives from a series of lectures given over the summer months of the year 594 A.D. by the founder of the T'ien-t'ai school of Chinese Buddhism, Chih-I (538-597). Kuan-ting, a disciple of Chih-i, took notes on these lectures and subsequently revised and edited them until they reached approximately the form in which the text is now available. The Mo-ho-chih-kuan is devoted to the elucidation of meditation techniques and their philosophical underpinnings. This is apparent from the title alone, which I have rendered "The Great Calming and Contemplation," and which represents the Sanskrit maha-samatha-vipasyana. Chih and kuan are the two aspects of meditation for Chih-I and the T'ien-t'ai school, signifying the negative and the positive approaches to religious practise: on the one hand the mental defilements, illusions and errors must be calmed, halted and eradicated (chih), and on the other hand the practitioner views, contemplates and has insight into (kuan ) the nature of Ultimate Reality. "Calming" (ohih) is quieting the mind, contemplation (kuan) is making it work properly. What I have undertaken to translate is the first chapter of the whole work, the Synopsis. This chapter may be considered a reduced-size version of the whole, though it also contains much material that is either not in the other chapters or is there presented in a different way. It is best known for its exposition of the "Four Kinds of Samadhi" or programs of religious practise: the constantly-sitting samadhi, the constantly-walking samadhi, the half-walking/half-sitting samadhi, and the neither-walking-nor-sitting samadhi. These involve respectively sitting quietly in the lotus posture, walking while reciting the name of the Buddha Amitabha, pronouncing dhavanls while alternating between sitting and walking, and using one's every thought and every act for contemplation. The author Chih-i classifies meditation (calming-and-contemplation) into three types: the gradual, the variable and the sudden. The Mo-ho- chih-kuan deals with the "sudden" variety, in which the practitioner's identity with Ultimate Reality is recognized from the very beginning of his religious practise. This form of meditation is consistent with the Mahayana Buddhist position that there is no ontological difference between the defilements of mind and enlightenment: there is nothing that does not enter into the nature of the Real. This chapter may be considered / Arts, Faculty of / Asian Studies, Department of / Graduate

No description available.

E système Mo-Ni-Re est un sous-système majeur des superalliages à base de Ni conçus pour une utilisation dans les applications à haute température. Compte tenu des contradictions entre les informations publiées antérieurement, cette étude a été consacrée à la détermination expérimentale complète des équilibres entre phases dans le système Mo-Ni-Re, à la caractérisation structurale des phases intermétalliques et à la modélisation thermodynamique du système à l'aide de la méthode CALPHAD. L'étude expérimentale des équilibres entre phases a été effectuée en utilisant des alliages à l'équilibre, et les diagrammes de phases du système Ni-Re et Mo-Ni-Re (à 1200°C et à 1600°C) ont été proposées. En comparaison avec les études précédentes, le diagramme de phases Ni-Re déterminé au cours de ce travail a montré des différences significatives en termes de domaines d'homogénéité, des domaines de cristallisation et de température de réaction péritectique. La coupe isotherme à 1200°C du système Mo-Ni-Re proposée lors de cette étude a montré l'extension importante de la phase σ du système binaire Mo-Re et de la phase δ du système Mo-Ni dans le diagramme ternaire. En outre, la présence de deux phases ternaires jusque-là inconnues a également été observée. La coupe isotherme du système Mo-Ni-Re à 1600°C a également montré une grande extension de la phase σ dans le diagramme ternaire tandis que l'extension de la phase χ du système Mo-Re dans les deux coupes isothermes est limitée à un étroit domaine de composition. Les phases ternaires observées dans la coupe isotherme à 1200°C ne sont pas présentes dans la coupe isotherme à 1600°C. D'autre part, les études partielles des domaines de composition des phases dans les systèmes binaires Mo-Ni et Mo-Re ainsi que la détermination de la projection du liquidus du système Mo-Ni-Re ont également été effectuées. La projection du liquidus du système Mo-Ni-Re proposée lors de la présente étude a également montré des champs de cristallisation primaire de la phase σ de système Mo-Re et la solution solide de Re dans la région ternaire qui sont largement étendus. Puisque la coupe isotherme du système Mo-Ni-Re a montré un domaine d'homogénéité de la phase σ très étendu, la caractérisation structurale de la phase σ du système ternaire Mo-Ni-Re a été effectuée en mettant l'accent sur la détermination de l'occupation des sites en fonction de la composition par affinement de Rietveld combiné des données de diffraction des rayons X et des neutrons. Les résultats expérimentaux recueillis au cours de cette étude ainsi que les informations disponibles dans la littérature ont été utilisés comme données d'entrée pour la modélisation thermodynamique du système Mo-Ni-Re. La description thermodynamique du système Mo-Re a été prise de la littérature tandis que les optimisations thermodynamiques des systèmes Mo-Ni, Ni-Re et Mo-Ni-Re ont été effectuées au cours de ce travail avec la méthode CALHAD.Mots-clés: Mo-Ni, Mo-Re, Ni-Re, Mo-Ni-Re; diagramme de phases; coupe isotherme; caractérisation structurale; modélisation thermodynamique; méthode CALPHAD / The Mo-Ni-Re system is one of the important subsystems of the Ni based superalloys engineered for use in high temperature applications. Considering the contradictions among previously reported information, the present study was devoted to the complete experimental determination of the phase equilibria in the Mo-Ni-Re system, structural characterization of its intermetallic phases and thermodynamic modeling of the system with the help of the CALPHAD method. The experimental investigation of phase equilibria was carried out with the help of equilibrated alloys and phase diagrams of the Ni-Re and Mo-Ni-Re system (at 1200°C and 1600°C) were proposed. In comparison with previous investigations, the Ni-Re phase diagram determined during the present study showed significant difference in terms of homogeneity domains, freezing ranges and peritectic reaction temperature. The 1200°C isothermal section of the Mo-Ni-Re system proposed during the present study showed large extension of the Mo-Re σ phase and Mo-Ni δ phase in the ternary region. In addition, presence of two previously unknown ternary phases was also observed. The isothermal section of the Mo-Ni-Re system at 1600°C also showed large extension of σ phase in the ternary region whereas extension of the Mo-Re χ phase in both isothermal sections was restricted to narrow composition range. The presence of the ternary phases observed in the 1200°C isothermal was not evidenced in 1600°C isothermal section. On the other hand, partial investigations of phase boundaries in the Mo-Ni and Mo-Re binary systems and determination of liquidus projection of the Mo-Ni-Re system was also carried out. The liquidus projection of the Mo-Ni-Re system proposed during present study also showed largely extended primary crystallization fields of the Mo-Re σ phase and Re solid solution in the ternary region. Since isothermal sections of the Mo-Ni-Re system showed largely extended homogeneity domain of σ, structural characterization of the Mo-Ni-Re σ with particular emphasis on determination of site occupancy trends as a function of composition was carried out by combined Rietveld refinement of the X-ray and neutron diffraction data. The experimental results gathered during the present study along with the information available in the literature were used as input for thermodynamic modeling of the Mo-Ni-Re system. The thermodynamic description of the Mo-Re system was taken from literature whereas thermodynamic modeling of the Mo-Ni, Ni-Re and Mo-Ni-Re system was carried out during the present study with the help of the CALHAD method.Keywords: Mo-Ni; Mo-Re; Ni-Re; Mo-Ni-Re; phase diagram; isothermal section; structural characterization; thermodynamic modeling; CALPHAD method

L’étude menée sur le système Mo-Pt-Si vise à contribuer à la connaissance d’alliages métalliques complexes destinés à des applications à hautes températures rencontrées dans les industries aéronautiques ou verrières. Sa description d’un point de vue thermodynamique est rendu difficile par son caractère réfractaire lié à la présence du molybdène d’une part et à sa complexité due au nombre élevé de ses constituants (3 éléments) d’autre part. Seule une approche du problème par une modélisation thermodynamique de type CALPHAD permet d’aboutir à un résultat significatif. Comme l’impose l’établissement d’une modélisation d’un système ternaire, à savoir l’étude préalable des trois bordures binaires, le premier volet de ce travail a été consacré à l’étude des systèmes Pt-Si, Mo-Pt et Mo-Si. Parallèlement au travail d’optimisation, des mesures expérimentales réalisées dans le cadre de cette étude (radiocristallographie, analyse thermique, microsonde,….) ont permis de déterminer les équilibres entre phases, les enthalpies de formation des différents composés intermétalliques ainsi que les mécanismes structuraux responsables des grands domaines de stabilité observés pour certaines phases. La première approche du système ternaire Mo-Pt-Si, obtenue à partir de la banque de données intégrant les optimisations binaires, a permis de cibler et interpréter des expériences de contrôles des équilibres entre phases en condition isotherme et anisotherme. Un nouveau siliciure ternaire a ainsi été découvert et pris en compte dans le calcul. Enfin, à travers de nombreux exemples nous montrons la cohérence de la modélisation avec l’ensemble des données expérimentales. / The study on the Mo-Pt-Si system contributes to the knowledge of complex metal alloy, which are intended for applications at high temperatures in the aerospace or glass industries. Its thermodynamic description is difficult because its refractory character related to the presence of the molybdenum and to its complexity due to the high number of the constituents (3 elements). Only an approach of problem by a modelling thermodynamics of CALPHAD type gives to a significant result. As imposes the establishment of a modelling of a ternary system by the study of three binary borders, the first part of this work was devoted to the study of Pt-Si, Mo-Pt and Mo-Si systems. Along with the optimization, an experimental measurements used in this study (X-ray, thermal analysis, microprobe,….) allowed to determine the equilibria phases, the enthalpies of formation of the various intermetallic compounds as well as the structural mechanisms responsible for large domains of stability observed for some phases. The first approach of the Mo-Pt-Si ternary system obtained from the database including the binary optimisations, allowed to interpret the experiments of controls of equilibria phases in isotherm and anisotherm conditions. A new ternary silicide was discovered and took into account in calculation. Finally, through many examples we show the agreement of the modelling with all experimental data.

Neste trabalho os parâmetros de fabricação de alvos de dispersão UAlx-Al foram definidos aplicando-se a tecnologia de montagem e laminação de um conjunto núcleo-moldura-revestimentos tradicionalmente adotada na fabricação de placas combustíveis usadas em reatores de pesquisa. O uso das técnicas de dilatometria e difração de raios-x com refinamento de Rietveld contribuíram para desenvolver um processamento termomecânico para controle das fases presentes no núcleo do alvo. Um método inovador que permitiu o aumento da produtividade desse tipo de alvo também foi desenvolvido com base na laminação de múltiplos núcleos. O processo de fabricação mostrou-se adequado para produção de alvos com a especificação para produção de Mo-99 no Reator Multipropósito Brasileiro (RMB). / At this work, the manufacturing parameters of uranium aluminide dispersion targets (UAlx-Al) were defined applying the picture-frame technique, traditionally adopted to manufacture fuel plates used in research reactors. The use of dilatometric and X-ray analysis supported the development of a thermomechanical processing to control the phases present in the target meat. It was also developed a method to quantify uranium aluminides phases. An innovative method that allowed to increase the productivity of this type of target was also developed based on multicore rolling. The manufacturing process proved to be suitable for the production of targets fulfilling the specification to produce Mo-99 in the Brazilian Multipurpose Reactor.

Estudou-se a caracterização de blocos sinterizados à base de Co-Cr-Mo visando a obtenção de próteses odontológicas por fresagem CAD/CAM. O processo de sinterização foi estudado e ocorreu através do transporte difusional de massa e calor no estado sólido, denominado sinterização no estado sólido. Esse fenômeno produz uma forte união entre as partículas devido ao transporte de massa, em escala atômica, sob condições controladas de tempo, temperatura e atmosfera. Foram realizadas sinterizações interrompidas a 800, 1000, 1200 e 1300°C nos tempos de 15 minutos, 1 hora e 4 horas. A liga foi caracterizada nas condições recebida e sinterizadas em termos de composição química, propriedades mecânicas e caracterização microestrutural. Para isto, utilizou-se fluorescência de raios X, dilatometria, ensaios de Arquimedes, ensaios de dureza, ensaios de compressão, microscopia eletrônica de varredura (MEV), microscopia óptica e microanálise eletrônica dispersiva (EDS). Os resultados composicionais indicam que a liga se encontrava dentro da faixa de composição química estabelecida pelo manual do fabricante e pela norma ASTM 1537. As partículas analisadas na condição pré-sinterizada exibiram formato esférico, indicando uma provável utilização de pós atomizados. A estimativa do levantamento da distribuição do tamanho das partículas foi realizado utilizando o programa de computador ImageJ, e a distribuição foi caracterizada como assimétrica positiva. O material no estado recebido se apresentou monofásico. A fase presente encontrada foi ?Co com estrutura cristalina CFC. Em contrapartida, as amostras sinterizadas apresentaram porções de fase ?Co, com estrutura cristalina hexagonal, fase esta formada a partir da transformação ?Co <-> ?Co, na qual, a energia armazenada na forma de defeitos é a força motriz da transformação. E sugere que a transformação ocorreu durante resfriamento. A amostra sinterizada por quatro horas em 1200°C apresentou-se no estágio final de sinterização, dado que os poros encontrados tinham aspecto arredondado e com densificação maior que 90%. Os resultados de compressão indicam tensão média de ruptura de 2523 ± 168 MPa. / This work studied the characterization of Co-Cr-Mo sintered blocks in order to obtain dental prosthesis by prototyping CAD/CAM. The sintering process was studied through diffusional mass transport in solid state, termed solid state sintering. This phenomenon produces a strong bond between the particles due to mass transport, at the atomic scale, under controlled conditions of time, temperature and atmosphere. The interrupted sintering was performed at 800, 1000, 1200 and 1300 ° C in times to 15 minutes, 1 hour and 4 hours. The alloy was characterized in conditions as received and sintered in terms of chemical composition, mechanical properties and microstructural characterization. For this, we used X-ray fluorescence, dilatometry, Archimedes tests, hardness tests, compression tests, scanning electron microscopy (SEM), optical microscopy and dispersive electron microanalysis (EDS). The results indicate that the alloy was within the chemical composition range established by the manufacturer and ASTM 1537. The particles analyzed in the pre-sintered condition showed spherical shape, indicating a likely use of atomized powders. The estimate of the particle size distribution was performed using ImageJ software, and the distribution is characterized as positive asymmetric. The samples in the received state were monophasic. This phase was found ?Co with FCC crystal structure. On the order hand, the sintered samples showed ?Co phase portions with hexagonal crystal structure, phase formed from the transformation ?Co <-> ?Co, in which the energy stored in the form of defects is the driving force of transformation and suggests that transformation occurred during the cooling. Sample sintered during four hours at 1200°C was in the final stages of sintering, since the pores were found aspect rounded and densification above 90%. The compression results indicate rupture stress at 2523 ± 168 MPa.