Release of metallic fission products from fully intact tri-structural isotropic (TRISO) fuel particles raises serious concern on the safety of high temperature gas-cooled reactors (HTGRs). In TRISO particles, SiC and/or ZrC coating is considered as the major barrier for the migration of the fission products. This thesis focuses on the migration mechanism study of Ag in SiC and Pd in ZrC.The mechanism of the migration of Ag in SiC is a long-lasting mystery. None of the currently existing models could satisfactorily explain the reported experimental facts. In this work, a new mechanism, termed as the “reaction-recrystallization” model, is proposed to explain the Ag migration behavior through SiC. Designed SiC/Ag diffusion couple experiments were carried out, and the results indicate that Ag migrates in SiC by the following three steps. First, Ag reacts with SiC to form an Ag-Si alloy (reaction). Second, carbon precipitates as a second phase and subsequently reacts with the Ag-Si alloy to form new β-SiC (recrystallization). Third, the Ag-Si alloy penetrates through the SiC layer by wetting its grain boundaries (migration). The validity of the proposed model was supported by thermodynamic calculations. (Chapter 3) The finding that SiC could be recrystallized in the presence of Ag inspires the idea of Ag-assisted crack healing in SiC. Cracks were intentionally generated by indenting the bulk SiC by a Vickers indenter. After vacuum annealing with Ag powder, the indent impressions were healed by newly-formed β-SiC grains with a recovery ratio of~ 60%. Median cracks were fully healed by both newly formed SiC and Ag-Si nodules. TEM observation reveals that the newly formed β-SiC layer is presented between the Ag-Si nodule and pristine SiC crack surface and smooths the tortuous crack surface. The above result is in potential to solve the problem of brittleness of SiC as a structural material. (Chapter 4)ZrC is considered as a candidate to replace SiC in TRISO fuel particles. The migration behavior of Pd in ZrC was investigated by designed Pd/ZrC diffusion couple experiments. It is found that ZrC reacts with Pd at temperatures higher than 600 °C to form Pd3Zr and amorphous carbon. The reaction kinetics parameters, i.e., the activation energy and the reaction order, along with the inter-diffusion coefficients of Zr and Pd, were calculated based on established models. These results provide preliminary explanation to the Pd migration in ZrC (Chapter 5).

Submitted by Núcleo de Pós-Graduação Administração (npgadm@ufba.br) on 2018-04-06T14:59:30Z No. of bitstreams: 1 Dissertação de Mestrado - Clarice Rodrigues da Silva.pdf: 1349322 bytes, checksum: fd7161034dded186d14a457032848709 (MD5) / Approved for entry into archive by Maria Angela Dortas (dortas@ufba.br) on 2018-04-10T18:04:56Z (GMT) No. of bitstreams: 1 Dissertação de Mestrado - Clarice Rodrigues da Silva.pdf: 1349322 bytes, checksum: fd7161034dded186d14a457032848709 (MD5) / Made available in DSpace on 2018-04-10T18:04:56Z (GMT). No. of bitstreams: 1 Dissertação de Mestrado - Clarice Rodrigues da Silva.pdf: 1349322 bytes, checksum: fd7161034dded186d14a457032848709 (MD5) / Ao longo dos últimos anos o Brasil vem editando leis que se destinam a promover a transparência pública, bem como incentivar a participação da sociedade na tomada de decisão e na gestão das instituições. Este estudo visa contribuir para a reflexão sobre essa transparência e participação nos processos institucionais do IFNMG por meio dos canais de interlocução e-SIC e Ouvidoria. Essas instâncias de participação, portanto, serviram como Feedback, fornecendo informações críticas para o ajuste das rotinas e procedimentos da Instituição. Assim, este trabalho propõe-se pesquisar a rotina de análise e atendimento dessas demandas para verificar se as mesmas trazem, em sua essência, propostas de melhorias dos processos institucionais. Buscou-se, também, avaliar a percepção dos gestores dos setores demandados em relação aos temas pesquisados, assim como verificar os encaminhamentos dados pelos mesmos ao responder a demanda. Outro item avaliado foi a qualidade das demandas recebidas sob a perspectiva da promoção de melhorias nos processos. Por meio de pesquisa documental e de questionários respondidos pelos gestores demandados, baseado em uma abordagem qualitativa, foi possível classificar as demandas dos cidadãos e identificar as que tinham possibilidade de promover mudanças. O trabalho está dividido em três partes: A primeira justifica a pesquisa, descrevendo seus objetivos. Em seguida apresenta-se o IFNMG e a região onde o mesmo está inserido. A segunda parte inicia-se com a reforma do Estado e os modelos de gestão adotados ao longo do tempo. Conceitua também a transparência pública, participação social, a Lei de acesso a informação, os canais de interlocução e-SIC e Ouvidoria e a importância de todos eles no modelo de gestão atual. A terceira parte descreve como a pesquisa foi realizada, apresentando uma análise sobre as demandas dos canais e sobre as respostas dos gestores ao questionário. Ao final, com base nas análises, apresenta-se a conclusão do trabalho. / Over the last few years, Brazil has been issuing laws designed to promote public transparency, as well as encouraging the participation of society in decision-making and in the management of institutions. This study aims to contribute to the reflection on this transparency and participation in IFNMG institutional processes through the interlocution channels of e-SIC and Ombudsman. These participation instances, therefore, would serve as Feedback, providing critical information for the adjustment of routines and procedures of the Institution. Thus, what we are going to research is the routine of analysis and attendance of these demands to verify if they bring, in essence, proposals of improvements of the institutional processes. It was also sought to evaluate the perception of the managers of the respondent sectors in relation to the researched topics, as well as to verify the referrals given by them when responding to the demand. Another item evaluated was the quality of the demands received from the perspective of promoting improvements in the processes. Through documentary research and questionnaires answered by the respondent managers, based on a qualitative approach, it was possible to classify the demands of the citizens and to identify those that had the possibility to promote changes. The paper is divided into three parts: The first justifies the research, describing its objectives. Then displays the IFNMG and the region where it is inserted. The second part begins with the reform of the State and the management models adopted over time. It also conceptualizes public transparency, social participation, the Law on access to information, e-SIC and Ombudsmanchannels of communication and the importance of all of them in the current management model. The third part describes how the research was carried out, presenting an analysis on the demands of the channels and on the questionnaire managers' responses. At the end, based on the analyzes, the conclusion of the work is presented.

La gestion de l'énergie électrique est au cœur des enjeux environnementaux. L'éclosion de semi-conducteurs à grand gap comme le carbure de silicium (SiC) permet la réalisation de composants aux performances supérieures à celles des composants en silicium pour l'électronique de puissance. Toutefois, le comportement de ces dispositifs lors de décharges électrostatiques (ESD) ou lors de radiations est mal connu et nécessite des études spécifiques. Dans ces travaux, plusieurs composants MESFET SiC ont ainsi été testés face aux ESD et l'étude des mécanismes de défaillance a montré soit la défaillance de l'oxyde de passivation, soit la sublimation du SiC suite au déclenchement d'une structure parasite. L'intégration d'une diode Zener sur le drain du MESFET a ainsi été testée et validée comme protection ESD. La simulation démontre que la protection est inefficace par rapport à la tenue aux radiations d'ions lourds. Assurer la robustesse de ces technologies n'apparaît pas plus simple que pour les composants en silicium. Des solutions sont toutefois envisageables pour aider les concepteurs à améliorer la robustesse aux ESD, bien que des études supplémentaires restent à mener. / Power management is nowadays crucial with the global warming and the electronic needs of the society. Wideband gap semi-conductors like Silicon Carbide (SiC) are emerging in power electronic landscape because of their better properties in comparison with Silicon. Nevertheless reliability and knowledge about internal physic during electrostatic discharge (ESD) or radiation event is still missing and need specific studies. In this work, several SiC MESFET have been tested and results show two mains failure mechanism. First the passivation oxide clamping, and secondly the SiC sublimation induced by a parasitic structure in the device. An ESD protection was tested and validated. Unfortunately, this solution isn't efficient for heavy ion protection. Indeed, no impact on the radiation robustness is noticed on the MESFET during a radiation event. SiC ESD reliability doesn't look better than for Silicon devices. ESD robustness improvements are proposed in this work even if integration of this MESFET is still required to validate the improvement.

abstract: Two major challenges in the transformer-less, single-phase PV string inverters are common mode leakage currents and double-line-frequency power decoupling. In the proposed doubly-grounded inverter topology with innovative active-power-decoupling approach, both of these issues are simultaneously addressed. The topology allows the PV negative terminal to be directly connected to the neutral, thereby eliminating the common-mode ground-currents. The decoupling capacitance requirement is minimized by a dynamically-variable dc-link with large voltage swing, allowing an all-film-capacitor implementation. Furthermore, the use of wide-bandgap devices enables the converter operation at higher switching frequency, resulting in smaller magnetic components. The operating principles, design and optimization, and control methods are explained in detail, and compared with other transformer-less, active-decoupling topologies. A 3 kVA, 100 kHz single-phase hardware prototype at 400 V dc nominal input and 240 V ac output has been developed using SiC MOSFETs with only 45 μF/1100 V dc-link capacitance. The proposed doubly-grounded topology is then extended for split-phase PV inverter application which results in significant reduction in both the peak and RMS values of the boost stage inductor current and allows for easy design of zero voltage transition. A topological enhancement involving T-type dc-ac stage is also developed which takes advantage of the three-level switching states with reduced voltage stress on the main switches, lower switching loss and almost halved inductor current ripple. In addition, this thesis also proposed two new schemes to improve the efficiency of conventional H-bridge inverter topology. The first scheme is to add an auxiliary zero-voltage-transition (ZVT) circuit to realize zero-voltage-switching (ZVS) for all the main switches and inherent zero-current-switching (ZCS) for the auxiliary switches. The advantages include the provision to implement zero state modulation schemes to decrease the inductor current THD, naturally adaptive auxiliary inductor current and elimination of need for large balancing capacitors. The second proposed scheme improves the system efficiency while still meeting a given THD requirement by implementing variable instantaneous switching frequency within a line frequency cycle. This scheme aims at minimizing the combined switching loss and inductor core loss by including different characteristics of the losses relative to the instantaneous switching frequency in the optimization process. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2017

The market for renewable energy sources, and solar cells in particular is growing year by year, as a result there is a large interest in research on new materials and new technologies for solar power applications. In this thesis the photovoltaic properties of cubic silicon carbide (3C-SiC) has been investigated. The research includes material growth using the sublimation epitaxy method, both n-type and p-type SiC have been investigated. 3C-SiC pn junctions have been produced and their electrical properties have been characterized, this is the first time 3C-SiC pn junctions have been studied in the research group. Photoresponse has been demonstrated from a 3C-SiC pn junction with Al and N used as p- and ntype dopants. This is the first demonstrated solar cell performance using 3C-SiC, to our knowledge.

Esta dissertação tem como tema a onerosidade excessiva no direito civil brasileiro. Primeiramente, fazem-se necessários uma noção inicial da figura, uma delimitação conceitual do problema e uma síntese de seu desenvolvimento histórico no direito civil brasileiro. Feito isso, são apresentadas as teorias utilizadas para sua fundamentação pela doutrina e pela jurisprudência brasileiras antes do advento de texto legal expresso sobre a matéria. Concluída essa fase preparatória, adentra-se no direito positivo vigente, precisamente no Código Civil, para explicar o conteúdo da onerosidade excessiva, de seus pressupostos e de suas conseqüências. São diretamente estudados os artigos 478, 479, 480, 317 e ainda outros específicos de alguns tipos contratuais. São abordados ainda alguns tópicos correlatos que finalizam o entendimento da matéria, como os pressupostos negativos da figura, sua incidência em contratos de sinalagma indireto e nos contratos aleatórios e as diferenças nos pressupostos para sua configuração no Código de Defesa do Consumidor. / The theme of this dissertation is known in english as hardship, which means the fundamental alteration of the equilibrium of the contract. Firstly, it is necessary to make an introductional notion of the figure, a conceptual delineation of the problem and a summary of its historical evolution in the brazilian civil law. After that, it is presented the theories used by authors and courts to reason the solution of the problem before the existence of legal text about the issue. Then, we study the related articles of the Brazilian Civil Code to explain the content of hardship, the content of its requirements, and the content of its consequences. The articles 478, 479, 480, 317 are directly studied, and also other articles from particular named contracts. Some related issues finalize the understanding of the theme, as the negative requirements of the figure, its incidence in some particular categories of contracts, and the difference of its requirements in the Consumer Defense Code.

abstract: The most important metrics considered for electric vehicles are power density, efficiency, and reliability of the powertrain modules. The powertrain comprises of an Electric Machine (EM), power electronic converters, an Energy Management System (EMS), and an Energy Storage System (ESS). The power electronic converters are used to couple the motor with the battery stack. Including a DC/DC converter in the powertrain module is favored as it adds an additional degree of freedom to achieve flexibility in optimizing the battery module and inverter independently. However, it is essential that the converter is rated for high peak power and can maintain high efficiency while operating over a wide range of load conditions to not compromise on system efficiency. Additionally, the converter must strictly adhere to all automotive standards. Currently, several hard-switching topologies have been employed such as conventional boost DC/DC, interleaved step-up DC/DC, and full-bridge DC/DC converter. These converters face respective limitations in achieving high step-up conversion ratio, size and weight issues, or high component count. In this work, a bi-directional synchronous boost DC/DC converter with easy interleaving capability is proposed with a novel ZVT mechanism. This converter steps up the EV battery voltage of 200V-300V to a wide range of variable output voltages ranging from 310V-800V. High power density and efficiency are achieved through high switching frequency of 250kHz for each phase with effective frequency doubling through interleaving. Also, use of wide bandgap high voltage SiC switches allows high efficiency operation even at high temperatures. Comprehensive analysis, design details and extensive simulation results are presented. Incorporating ZVT branch with adaptive time delay results in converter efficiency close to 98%. Experimental results from a 2.5kW hardware prototype validate the performance of the proposed approach. A peak efficiency of 98.17% has been observed in hardware in the boost or motoring mode. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2018

Submitted by Fernanda Rodrigues de Lima (fernanda.rlima@ufpe.br) on 2018-08-28T22:32:40Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) TESE Roseana Florentino Pereira.pdf: 5029115 bytes, checksum: 567d2593b0716a916a10f59de192c44d (MD5) / Approved for entry into archive by Alice Araujo (alice.caraujo@ufpe.br) on 2018-09-06T22:58:01Z (GMT) No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) TESE Roseana Florentino Pereira.pdf: 5029115 bytes, checksum: 567d2593b0716a916a10f59de192c44d (MD5) / Made available in DSpace on 2018-09-06T22:58:01Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) TESE Roseana Florentino Pereira.pdf: 5029115 bytes, checksum: 567d2593b0716a916a10f59de192c44d (MD5) Previous issue date: 2017-07-27 / No presente trabalho, revestimentos nanocompósitos de Ni-Co/SiC foram desenvolvidos por codeposição de nanopartículas de SiC em um banho eletrolítico com níquel e cobalto, utilizando o aço API 5L X80 como substrato. A influência da densidade de corrente catódica nas propriedades dos depósitos foi investigada e correlacionada com a eficiência de corrente. A morfologia e composição química da superfície e secção transversal dos revestimentos foi analisada por microscopia eletrônica de varredura acoplada com energia dispersiva de raios-X (MEV-EDS) e relacionadas aos resultados de microdureza Vickers (HV) e difração de raios-X (DRX). A adesividade foi verificada pela indentação Rockwell C. Medidas de potencial de circuito aberto (PCA), curvas de polarização potenciodinâmica (PP) e espectroscopia de impedância eletroquímica (EIE) foram realizadas em solução de NaCl 3,5% para investigar a resistência à corrosão. Os resultados mostraram que os revestimentos obtidos possuem morfologia de grãos ramificados em forma de agulha, com valores de microdureza mais elevados do que a microdureza do aço carbono e estrutura de fase cúbica de face centrada com orientação preferencial do plano (220). Através da análise da secção transversal dos depósitos, verificou-se que os mesmos eram formados por camadas intermediárias com composições e microdurezas distintas, de acordo com a densidade de corrente catódica aplicada. Os revestimentos nanocompósitos de Ni-Co/SiC deslocaram o potencial de corrosão para valores mais nobres e aumentaram a resistência à polarização, que resultou em taxas de corrosão mais baixas quando comparadas ao aço API 5L X80 sem revestimento. O revestimento obtido na condição de 55 mA/cm² obteve as melhores propriedades de resistência à corrosão e o estudo cinético realizado nesta corrente revelou que a formação do revestimento ocorre através da depositação de camadas com caráter autocatalítico. / In the present work, Ni-Co / SiC nanocomposite coatings were developed by codepositioning of SiC nanoparticles in an electrolytic bath with nickel and cobalt using API 5L X80 steel as substrate. The influence of cathodic current density on deposit properties was investigated and correlated with current efficiency. The morphology and chemical composition of the surface and cross-section of the coatings was analyzed by scanning electron microscopy coupled with X-ray dispersive energy (SEM-EDS) and related to the results of Vickers microhardness (HV) and X-ray diffraction (XRD ). The adhesiveness was verified by the Rockwell C indentation. Open circuit potential (PCA) measurements, potentiodynamic polarization curves (PP) and electrochemical impedance spectroscopy (EIS) were performed in a 3.5% NaCl solution to investigate corrosion resistance . The results showed that the coatings obtained have a needle shaped branched grain morphology, with microhardness values higher than the carbon steel microhardness and a cubic face structure with a preferred orientation of the plane 220. Through the cross-sectional analysis of the deposits, it was found that they were formed by intermediary layers with different compositions and microhardness, according to the applied cathodic current density. Ni-Co / SiC nanocomposite coatings shifted corrosion potential to nobler values and increased bias resistance, which resulted in lower corrosion rates when compared to uncoated API 5L X80 steel. The coating obtained under the condition of 55 mA / cm 2 obtained the best corrosion resistance properties and the kinetic study carried out in this chain revealed that the formation of the coating occurs through the deposition of layers with an autocatalytic character.

Submitted by Geyciane Santos (geyciane_thamires@hotmail.com) on 2015-10-27T14:53:24Z No. of bitstreams: 1 Dissertação - Bartolomeu Miranda Pereira.pdf: 2513984 bytes, checksum: ac4f90f59a8936504d8143511e5ee406 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-10-27T19:58:17Z (GMT) No. of bitstreams: 1 Dissertação - Bartolomeu Miranda Pereira.pdf: 2513984 bytes, checksum: ac4f90f59a8936504d8143511e5ee406 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-10-27T20:07:15Z (GMT) No. of bitstreams: 1 Dissertação - Bartolomeu Miranda Pereira.pdf: 2513984 bytes, checksum: ac4f90f59a8936504d8143511e5ee406 (MD5) / Made available in DSpace on 2015-10-27T20:07:15Z (GMT). No. of bitstreams: 1 Dissertação - Bartolomeu Miranda Pereira.pdf: 2513984 bytes, checksum: ac4f90f59a8936504d8143511e5ee406 (MD5) Previous issue date: 2014-10-02 / OUTRAS / In global scenario the companies seek for tools to minimize their cost and maximize their returns. The inventory management, as literature and evidenced in companies day-to-day activities, represents one important part of companies operational cost reduction strategy. The present research objective is evaluate the inventory management process and accounting information system (AIS) in one multinational at Amazon in agreement with IAS 2. The methodology can be classified as unique study case with descriptive scientific characteristic. The case selection happen by convenience and accessibility criteria. The research happen with bibliographies collection search and documental in legal bases, books, magazines and internet, searching the found material interpretation without data handling with study trusty focus. For study credibility increasing the individual questions have been developed for involved person enabling the theory and explored reality comparison. In the results there is evidence of inventory cost recognition as acquisition cost and its maintenance guide with key activities stopping acceptible risk. There is also evidence of AIS characteristics following IAS2 deeply influencing the business continuity and their maintenance process with high relevance. The research conclusion presents both inventory management processes and AIS as important items for business continuity. Both support key activities and provide information for organization strategic decision making. / No cenário globalizado, as empresas buscam ferramentas que minimizem seus custos operacionais e maximizem seus resultados. A gestão dos estoques, conforme a literatura e comprovadamente evidenciado no dia-a-dia das empresas, representa uma parte importante na composição das estratégias de redução de custo operacional das empresas. O objetivo principal desta pesquisa é avaliar os processos de gestão de estoque e sistema de informação contábil em uma multinacional na Amazônia conforme CPC 16R1. A metodologia utilizada pode ser classificada como estudo de caso único com características científicas descritivas. A seleção do caso ocorreu por critérios de acessibilidade e conveniência. A pesquisa aconteceu com consultas a acervos bibliográficos e documentais em bases legais, livros, revistas e internet, buscando a interpretação do material encontrado sem qualquer manipulação de dados focando na confiabilidade do estudo. Para aumento da credibilidade do estudo levantou-se necessidade de elaboração de questionários individuais para pessoas envolvidas nos processos e check list de características do SIC, habilitando a comparação da teoria com a realidade investigada. Nos resultados há evidências de reconhecimento dos custos dos estoques pelo valor de aquisição e sua manutenção é referenciada pelo nível aceitável dos riscos de parada das atividades chaves do negócio da empresa. Também evidencia-se a conformidade das características do SIC com CPC 16R1 influenciando profundamente os negócios da empresa sendo de alta relevância sua manutenção. A conclusão da pesquisa apresenta tanto a gestão dos estoques quanto os processos do SIC como itens de grande influência na continuidade dos negócios da empresa. Ambos suportam atividades chaves e fornecem informações para tomadas de decisões estratégicas para a organização.

Avec l’essor des technologies de l’information et de la communication, la société et les organisations se transforment, serecomposent tous secteurs confondus. On appelle communément disruption, le changement de paradigme économique etorganisationnel lié aux TIC, plus précisément, à la digitalisation des processus.Les modes d’échanges entre les hommes ont évolué. Notre mémoire de master 2 (Numérique, recomposition organisationnelles et appropriation des TIC, Gravereaux, 2013) nous aura permis de comprendre que les véritables changements qui opèrent en organisation se situent au-delà des usages des espaces numériques de travail et des outils TIC.Notre thèse s’inscrit dans la continuité de ce travail préliminaire qui nous avait offert de questionner, de manière introductive, quelle pouvait être la portée de la dimension politique dans l’appropriation des technologies numériques.Cette thèse de doctorat a pour but de saisir, d’identifier, d’analyser et de conceptualiser, tant sur le plan théorique que pratique, le processus de transition organisationnelle qui opère dans les établissements de santé traversés par l’informatisation du dossier de soin et par la maturation des Systèmes d’Information Hospitalier. Après avoir compris qu’il fallait dépasser les usages pour comprendre l’appropriation des TIC, nous orienterons nos réflexions et enquêtes de façon à confronter ce point de vue et à lui donner une portée opérationnelle.Les phénomènes communicationnels liés aux changements et aux transformations en organisations constituent un élément central de ces recompositions. Le chercheur doit enquêter pour questionner et saisir ces phénomènes à l’aune de la compréhension particulière d’un établissement de santé.Le regard communicationnel porté sur un espace, un vécu, en transition, tentera de mettre à jour les conditions qui participent de l’appropriation des nouveaux outils liés à la traçabilité des soins : la forme informatisée du dossier patient.Notre thèse de doctorat se propose d’apporter une contribution à des problématiques de recherches actuelles en questionnant l’individu au travail au regard des questions politico-organisationnelles liées à l’appropriation du dossier patient informatisé.Ces acteurs que nous sommes venus « étudié », soignants, médecins, personnels administratif, sont au coeur, vivent, en même temps que l’organisation, ce phénomène de disruption qui affecte l’intégralité du dispositif organisationnel.À partir d’une rupture disruptive, de nouvelles formes d’organisation du travail, liées aux changements de pratiques del’information médicale, apparaissent, émerge des dissonances. De la même façon, pour accompagner cette organisation émergente, les formes et normes de management en santé, sont amenées à se recomposer et donc à se spécialiser.Nous assistons à une recomposition globale de la Santé, dont les composantes du dispositif tendent à faire de la contribution, de la collaboration, de l’autonomie et de la traduction, les nouveaux fondamentaux du management en organisations de santé accompagnant la métamorphose digitale des routines des acteurs. / With the growth of information and communication technologies, society and organizations are transforming, recomposing all sectors combined. The common paradigm shift is to change the economic and organizational paradigm linked to ICT, more precisely, to the digitalization of processes.The modes of exchange between men have evolved. Our Master 2 thesis (Digital, Organizational Reorganization andAppropriation of ICTs, Gravereaux, 2013) allowed us to understand that the real changes that operate in organization arebeyond the use of digital workspaces and ICT tools.Our thesis is part of the continuation of this preliminary work which offered us to question, in an introductory way, what could be the scope of the political dimension in the appropriation of digital technologies.This doctoral thesis aims at capturing, identifying, analyzing and conceptualizing, both theoretically and practically, the process of organizational transition that operates in the healthcare institutions through which the computerization of the care file And by the maturation of Hospital Information Systems. Having understood that we need to go beyond the uses to understand ICT appropriation, we will orient our reflections and investigations in order to confront this point of view and to give it an operational scope.The communicationa phenomena linked to changes and transformations in organizations are a central element of theserecompositions. The researcher must investigate and question these phenomena in terms of the particular understanding of a healthcare institution.The communicative look at a space, a experience, in transition, will try to update the conditions that participate in the appropriation of the new tools related to the traceability of care: the computerized form of the patient record.Our doctoral thesis proposes to make a contribution to current research questions by questioning the individual at work withregard to the politico-organizational issues related to the appropriation of the computerized patient record.These actors, who have come to be "studied", caregivers, doctors and administrative staff, are at the heart of this phenomenon of disruption, which affects the entire organizational system, at the same time as the organization.From a disruptive rupture, new forms of work organization, linked to changes in the practices of medical information, emerge, emerging from dissonances. In the same way, to support this emerging organization, the forms and standards of health management, are led to recompose and therefore to specialize.We are witnessing a global recomposition of health, whose components of the system tend to make contribution, collaboration, autonomy and translation, new fundamentals of management in health organizations accompanying the digital metamorphosis of routines actors.