Ce mémoire présente la synthèse et la caractérisation du matériau composite Ce-TZP/Al2O3 et l’étude de ce matériau dans une mise en forme par impression 3D de type stéréolithographie (SLA). Le matériau Ce-TZP présente une résistance au vieillissement en milieu aqueux (par transformation martensitique de la phase tétragonale vers la phase monoclinique) accrue en comparaison à Y-TZP. L’ajout d’alumine (Al2O3) comme seconde phase confère au matériau des propriétés mécaniques (résistance à la flexion en particulier) similaires à Y-TZP. La mise en forme par SLA offre la possibilité de fabriquer des objets avec des structures complexes tout en limitant l’utilisation et la perte de matière en comparaison à la fabrication soustractive, bien connue dans le domaine dentaire.Le composite Ce-TZP/Al2O3 a été synthétisé à partir d’une poudre Ce-TZP à laquelle est ajoutée de l’Al2O3 selon deux protocoles : la méthode Pechini modifiée et la méthode Isopropoxyde. Les études dilatométriques et microstructurales des composites ont montré que le matériau obtenu selon la méthode Isopropoxyde était plus homogène. Cette synthèse a donc été sélectionnée pour réaliser l’étude du frittage. Les conditions optimales résultants de cette étude (rampe de 300 °C/h, T°palier de 1500 °C pendant 1h, air), permettent d’atteindre une densité relative de l’ordre de 98% avec une taille de grains submicronique pour les deux phases.Des formulations photoréticulables sous exposition UV, chargées avec ce composite ainsi qu’avec le matériau de référence Y-TZP, ont été développées et étudiées afin de pouvoir mettre en forme ces matériaux par SLA. Avant utilisation dans le procédé, les formulations ont été caractérisées d’un point de vue rhéologique, thermique et également d’un point de vue de la réactivité sous exposition UV. Ces caractérisations ont permis de déterminer l’influence de la nature et de la taille des particules sur la réactivité principalement, paramètre également gouvernée par la composition des résines et notamment par le système amorceur, composé de un ou plusieurs photoinitiateur(s). Pour finir, les pièces fabriquées par SLA ont été frittées et caractérisées d’un point de vue mécanique et microstructural. / This thesis presents the synthesis and characterization of Ce-TZP/Al2O3 composite material and the study of this material in stereolithography process (SLA). Ce-TZP material exhibits an enhanced resistance to low temperature degradation (materialized by the tetragonal/monoclinic phase transformation) compared to Y-TZP. The addition of alumina (Al2O3) as a second phase gives to the material mechanical properties (especially flexural strength) similar to Y-TZP. SLA shaping offers the ability to make objects with complex structures while limiting the use and loss of material compared to subtractive manufacturing, well known in the dental field.The Ce-TZP/Al2O3 composite was synthesized from a Ce-TZP powder mixed with Al2O3 added according to two protocols: the modified Pechini method and the Isopropoxide method. The dilatometric and microstructural studies of the composites have showed that the material obtained by the Isopropoxide method was more homogeneous. This synthesis was therefore selected to carry out the sintering study. The optimal conditions resulting from this study (heating rate of 300 °C/h, T°soak of 1500 °C for 1h, air) allow to reach a relative density of 98 % with a submicron grain size for the two phases.Photocurable under UV exposure formulations, loaded with this composite as well as with the reference material Y-TZP, have been developed and studied in order to be able to shape these materials by SLA. Prior to use in the process, the formulations were characterized from a rheological, thermal and also from a viewpoint of reactivity under UV exposure. These characterizations made it possible to determine the influence of the nature and the size of the particles on the reactivity mainly, also governed by the composition of the resins and in particular by the initiator system, composed of one or more photoinitiator(s). Finally, the parts manufactured by SLA were sintered and characterized from a mechanical and microstructural point of view.

<i>The Unravelers</i> is a Buddhist novel of literary fiction, which to my knowledge is the first in the last one hundred years to synthesize the Buddhist teachings and values found in the suttas of the <i>Pāli</i> Canon, the theory of ancient Indian <i>kāvya</i> literature, and the latest stylistic and structural innovations of contemporary literary fiction. The narrative follows four characters from the moment of their deaths as they manipulate the process of becoming—the mental act of creating and entering into “worlds”. The novel depicts the characters’ development of dispassion for a variety of realms, resulting in their eventual return to the human world with the motivation necessary to practice the Buddhist path. My critical essay opens with an introduction to <i>kāvya </i>and Theravāda Buddhist concepts that are particularly relevant to the process of creating a fictional world— namely, <i>saṅkhāra </i>(fabrication) and <i>bhava </i>(becoming)—and the inherent karma of writing. Section II “Literary Review” explores narrative modes from Theravāda Buddhist literature and develops them through experimental narrative modes of contemporary literary fiction. Section III discusses the depiction of becoming, fabrication, and dispassion through the novel’s characters. Section IV “<i>Rasa</i>,” explains the theory of how a reader experiences the work’s savor, while relating the use of <i>rasa </i>in<i> The Unravelers</i> to the early Buddhist <i>kāvyas </i>(the <i>Pāli </i>Canon’s <i>Udāna </i>and <i>Dhammapada</i>, and two works by Aśvaghoṣa). Section V evaluates the classic use of Buddhist concepts and metaphors in Aśvaghoṣa’s <i>Handsome Nanda</i> as compared to<i> The Unravelers</i>. Section VI examines Jack Kerouac’s <i>The Dharma Bums</i> as a forerunner to the genre of the Buddhist novel and Keith Kachtick’s <i>Hungry Ghost</i> as archetypal. Section VII concludes by detailing<i> The Unravelers</i>’ contribution to the Buddhist novel.

Cette thèse a pour but d’augmenter la durée de vie des moules pour l’injection plastique. Les principaux phénomènes à refréner sont l’usure par abrasion et l’usure par corrosion. Pour ce faire, deux familles de matériaux ont été présélectionnées. Il s’agit des aciers à outils inoxydables et des verres métalliques massifs. Ces travaux détaillent donc la sélection, le développement et la caractérisation d’une nuance pour chacune de ces familles. In fine, cette thèse délivre un nouvel acier adapté à la fabrication additive et aux moules d’injection plastique, allant de l’élaboration de la poudre à l’optimisation des paramètres LBM et de ceux du traitement thermique. Cet acier permet d’offrir un bon compromis en termes de propriétés thermiques, mécaniques et de résistance à la corrosion. Quant au verre métallique massif, ces travaux de thèse démontrent que la nuance choisie permet de conserver suffisamment de matériau amorphe pour induire des propriétés exceptionnelles. / The aim of this thesis is to increase molds lifetime. Mains phenomena to limit are abrasion wear and corrosion. For this purpose, two material families have been preselected. They have been identified among stainless steels and bulk metallic glasses. This work details their selection, development in additive manufacturing and characterization for both materials. In the end, this thesis delivers a new steel grade adapted to the additive manufacturing and plastic injection molds, which affords good corrosion resistance, high hardness and a comparatively good thermal conduction. Concerning the bulk metallic glass, this work shows that the chosen composition allowed to preserve enough amorphous material to induce exceptional properties and give strong hopes to continue in this vein.

Até recentemente as novas tecnologias de fabricação digital só eram encontradas na indústria e em algumas universidades. Hoje essas tecnologias estão cada vez mais acessíveis e baratas e têm se consolidado como grandes aliadas no processo de projeto em áreas como Arquitetura, Design e Engenharia. Ambientes como os Fab Labs têm auxiliado o processo de desenvolvimento de produto e a realização de experimentações através da prototipagem rápida e da fabricação digital, oferecendo de forma aberta, suporte na utilização de um conjunto de ferramentas digitais. Dessa forma, buscou-se, como objetivo geral neste trabalho, evidenciar o potencial dos Fab Labs como ambientes para o uso da fabricação digital e da prototipagem rápida no processo de projeto. Como forma de atingir esse objetivo, foi realizada uma pesquisa qualitativa, através de estudo de caso e por meio de entrevista com gestores de três Fab Labs situados no Brasil. Inicialmente, foi feita uma abordagem sobre temas como prototipagem rápida e fabricação digital, buscando o esclarecimento do tema e a formação do corpo teórico. A pesquisa bibliográfica abordou temas como tipos de protótipos e a importância do ato de prototipar. Os resultados obtidos por intermédio das entrevistas e das observações, apresenta considerações importantes em relação ao conceito Fab Lab enquanto potencializador no desenvolvimento de projetos. / Until recently the new digital manufacturing technologies were only found in the industry and some universities. Today these technologies are increasingly affordable and cheap and have been established as major allies in the design process in areas such as Architecture, Design and Engineering. Environments such as Fab Labs have aided the product development process and performing trials through rapid prototyping and digital fabrication, providing an open, support the use of a set of digital tools. Thus, it sought to, the general objective of this study was to highlight the potential of Fab Labs as environments for the use of digital manufacturing and rapid prototyping in the design process. In order to achieve this goal, a qualitative survey was conducted through case study and through interviews with managers of three Fab Labs located in Brazil. Initially, an approach on issues such as rapid prototyping and digital manufacturing was made, seeking the theme of enlightenment and the formation of the theoretical body. The literature has addressed such topics as types of prototypes and the importance of prototyping act. The results obtained through the interviews and observations, presents important considerations regarding the concept Fab Lab while potentiating the development projects.

abstract: This dissertation presents my work on development of deformable electronics using microelectromechanical systems (MEMS) based fabrication technologies. In recent years, deformable electronics are coming to revolutionize the functionality of microelectronics seamlessly with their application environment, ranging from various consumer electronics to bio-medical applications. Many researchers have studied this area, and a wide variety of devices have been fabricated. One traditional way is to directly fabricate electronic devices on flexible substrate through low-temperature processes. These devices suffered from constrained functionality due to the temperature limit. Another transfer printing approach has been developed recently. The general idea is to fabricate functional devices on hard and planar substrates using standard processes then transferred by elastomeric stamps and printed on desired flexible and stretchable substrates. The main disadvantages are that the transfer printing step may limit the yield. The third method is "flexible skins" which silicon substrates are thinned down and structured into islands and sandwiched by two layers of polymer. The main advantage of this method is post CMOS compatible. Based on this technology, we successfully fabricated a 3-D flexible thermal sensor for intravascular flow monitoring. The final product of the 3-D sensor has three independent sensing elements equally distributed around the wall of catheter (1.2 mm in diameter) with 120° spacing. This structure introduces three independent information channels, and cross-comparisons among all readings were utilized to eliminate experimental error and provide better measurement results. The novel fabrication and assembly technology can also be applied to other catheter based biomedical devices. A step forward inspired by the ancient art of folding, origami, which creating three-dimensional (3-D) structures from two-dimensional (2-D) sheets through a high degree of folding along the creases. Based on this idea, we developed a novel method to enable better deformability. One example is origami-enabled silicon solar cells. The solar panel can reach up to 644% areal compactness while maintain reasonable good performance (less than 30% output power density drop) upon 40 times cyclic folding/unfolding. This approach can be readily applied to other functional devices, ranging from sensors, displays, antenna, to energy storage devices. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2014

L'industrie microélectronique est engagée depuis longtemps dans des mesures visant à réduire ses impacts sur l'environnement, et ce sur toutes les phases du cycle de vie de ses produits. Sur les sites de fabrication, la suite logique à la mise en place de système de traitement des pollutions est l'anticipation de ces dernières. L'éco-conception des technologies microélectroniques, c'est-à-dire l'intégration de paramètres environnementaux dans leur processus de développement, permet de répondre à cet objectif. Notre travail de recherche a pour but de caractériser environnementalement les procédés de fabrication microélectronique afin de proposer des outils et méthodes pour leurs concepteurs. Nous avons donc modélisé une technologie microélectronique, et associé des impacts environnementaux aux flux entrants et sortants. Cela nous a permis de proposer des indicateurs environnementaux destinés à la R&D et adaptés à un site de développement et de production microélectronique. / The microelectronic industry has been engaged for a long time in measures to reduce its impacts on the environment, regarding all the life cycle phases of its products. For the manufacturing sites, the logical follow-ups to the implementation of pollutions treatment systems are their anticipation. The eco-design of microelectronic technologies, that is the integration of environmental parameters in their development process, enables to meet this objective. The aim of our research work is to environmentally characterize the microelectronic manufacturing processes to propose tools and methods for their designers. Therefore, we modeled a microelectronic technology, and we matched environmental impacts with its inputs and outputs. This allows us to suggest environmental indicators for the R&D, which are adapted to a microelectronic development and manufacturing site.

The use of optical fibre as a mechanism for the delivery of the trapping laser beam to the sample chamber significantly reduces both the size and the build costs of “Optical Tweezers”. Furthermore, the use of fibre facilitates the decoupling of the optical trapping beam from the microscope optics, which provides further scope for the development of a portable optical trapping system, and the potential for uncomplicated integration with other advanced microscopy systems such as an atomic force microscope (AFM) for example. For use with an AFM, the optical fibre must be inserted at an angle of 10° with respect to the sample chamber floor. However, previous literature suggests that 3D optical trapping with a single fibre inserted at an angle ≤20° is not feasible. This thesis presents the design, development, build and test of a single beam optical fibre based gradient force optical tweezers system and its associated software. An investigation is conducted to ascertain why optical trapping, using single fibre systems, cannot be achieved at sub 20° insertion angles, the result of which formed the basis of a hypothesis that explains this limitation. This finding led to the development of tapered optical fibre tips that are cable of 3D optical trapping at an insertion angle of ≤10°. The optimised optical fibre tapers are presented and their ability to trap both organic and inanimate material in 3D at an insertion angle of 10° is demonstrated. The near-horizontal insertion angle introduced a maximum trapping range (MTR). The MTR of the tips is determined empirically, evaluated against simulated data, and found to be tuneable through taper optimisation. Optical trap characterisation has been undertaken in terms of the optical trapping forces acting on the trapping subjects. Finally, the fibre tapering devices ability to reproduce identical tapers, or not, using the same device parameters, was investigated and the results in terms of geometric profile and optical performance are presented.

Submitted by Izabel Franco (izabel-franco@ufscar.br) on 2016-10-10T19:45:50Z No. of bitstreams: 1 DissCCSad.pdf: 4130188 bytes, checksum: ae1739e6fd0c5b8eb0bd2f55b1be6301 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-10-21T12:03:41Z (GMT) No. of bitstreams: 1 DissCCSad.pdf: 4130188 bytes, checksum: ae1739e6fd0c5b8eb0bd2f55b1be6301 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-10-21T12:03:47Z (GMT) No. of bitstreams: 1 DissCCSad.pdf: 4130188 bytes, checksum: ae1739e6fd0c5b8eb0bd2f55b1be6301 (MD5) / Made available in DSpace on 2016-10-21T12:03:53Z (GMT). No. of bitstreams: 1 DissCCSad.pdf: 4130188 bytes, checksum: ae1739e6fd0c5b8eb0bd2f55b1be6301 (MD5) Previous issue date: 2016-06-17 / Não recebi financiamento / The paper it is a scientific and technological study about quality control in the fabrication and assembly of steel structures, developed through the analysis and interpretation of information obtained from literature surveys, technical visits and interviews with companies in the sector, highlighting the knowledge the existing literature. Therefore, they will discuss the processes for obtaining structural steel and its properties, the various stages of fabrication and assembly of steel structures, as well as nondestructive testing. The survey aims to define inspection criteria for the fabrication and assembly of steel structures for early identification of pathological manifestations, present the main pathological symptoms found in steel structures, establishing its origins and causes, exposing a flow chart of the process production of a steel structure showing the main performance checkpoints and, finally, to analyze certain pathological events, indicating failures in the production process. It is concluded that there are precautions to be observed not to make constructive errors, easily preventable through efficient planning and supervision. The study's aim is to promote the exchange of research results to the productive sector and assist in the review and development of standards. / Este trabalho é um estudo científico e tecnológico sobre o controle de qualidade na fabricação e montagem de estruturas metálicas, elaborado por meio da análise e interpretação de informações obtidas em levantamentos bibliográficos, visitas técnicas e entrevistas à empresas do setor, evidenciando o conhecimento da literatura existente. Sendo assim, são abordados os processos de obtenção do aço estrutural e suas propriedades, as diversas etapas da fabricação e da montagem das estruturas metálicas, assim como ensaios não destrutivos. A pesquisa tem como objetivos, definir critérios de inspeção durante a fabricação e a montagem das estruturas metálicas, para identificação prematura de manifestações patológicas, apresentar os principais sintomas patológicos encontradas em estruturas de aço, estabelecendo suas origens e causas, expor um fluxograma sobre o processo de produção de uma estrutura metálica, indicando os principais pontos de checagem de desempenho e, por fim, analisar algumas manifestações patológicas, indicando as falhas no processo de produção. Conclui-se que existem cuidados a serem observados para não cometer erros construtivos, facilmente evitáveis por meio de planejamento e fiscalização eficientes. O intuito do estudo é promover o intercâmbio dos resultados da pesquisa com o setor produtivo e colaborar na revisão e elaboração de normas.

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Made available in DSpace on 2014-10-09T12:44:24Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:08:21Z (GMT). No. of bitstreams: 0 / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP