Download or read book tude des m canismes de la plasticit dans les verres m talliques massifs written by Minh Thanh Thai and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Étude des mécanismes de la plasticité dans les verres métalliques massifs. Ce travail a porté sur une approche des mécanismes de la plasticité à la transition vitreuse dans les verres métalliques massifs base zirconium. Une étude bibliographique des verres métalliques, ses caractéristiques essentielles a été tout d'abord introduite, particulièrement orientée vers leurs propriétés de stabilité structurale, ainsi que vers leurs propriétés mécaniques à haute température. Le modèle de volume libre (selon l'approche de Spaepen) a été utilisé dans une modélisation par éléments finis de la plasticité du verre. Le verre métallique de composition Zr_{52,5}Cu_{22}Al_{10}Ni_{13}Ti_{2,5}, étudié dans cette thèse, est élaboré par différentes méthodes d'hypertrempe sous forme de barreaux et de rubans. Les caractérisations physico-chimiques ont été menées par DSC, DRX et MEB. Les résultats de DSC ont montré que les verres élaborés possèdent un large intervalle de transition vitreuse et une bonne stabilité thermique. L'étude couplant DSC et DRX à haute température a permis d'établir la nature des phases et leur ordre d'apparition en cours de cristallisation. La transition vitreuse et la cristallisation ont été étudiées en détail par DSC modulée (MDSC) par la suite. La cinétique de cristallisation du verre a été généralement analysée par DSC isotherme.La caractérisation de la relaxation du verre métallique à partir de traitements thermiques successifs, par DSC et DRX à température proche de la température de transition vitreuse T_g pendant des temps différents, est rapportée dans le quatrième chapitre. Ce phénomène de relaxation peut être observé directement par les études structurales en utilisant la DSC et la diffraction des rayons X. Ensuite, l'évolution de la relaxation du verre est étudiée par mesure de dureté et de densité. La variation de la dureté H_v par rapport à la profondeur de pénétrateur h, après les traitements thermiques, a été menée par micro-dureté. La mesure de volumique du verre Zr_{52,5}Cu_{22}Al_{10}Ni_{13}Ti_{2,5} a été menée après les différents temps de relaxation thermique, nous donnent une densité d'environ de 6,769g/cm^3. Les traitements thermiques isothermes sur ce verre ont montré une augmentation de sa densité au cours du temps. Afin d'observer l'apparition puis l'évolution des mécanismes de déformation dans le verre métallique à l'échelle locale, une nouvelle technique - lithographie électronique - avec un dispositif d'essai mécanique in situ, permettant de déposer des microgrilles à la surface d'une éprouvette et de réaliser un essai de compression dans un MEB, est présentée dans le cinquième chapitre. Puis, les résultats sont analysés par corrélation d'images. La démarche expérimentale des essais MEB in situ est détaillée dans ce chapitre.Des essais à vitesse de déformation constante sont présentées dans le chapitre suivant. Ils ont été conduits dans l'intervalle de transition vitreuse (entre 673K et 713K). Enfin, les études de champs de déformation par corrélation d'image ont montré une limite de détection de la localisation supérieure à 2 micromètre sur les cartes de déformation. S'il y a des bandes de cisaillement, soit leurs déformation en inférieure à celles due à l'oxydation, soit elles sont plus fines que 2 micromètre (échelle de mesure). Le dernier chapitre présente une modélisation pour décrire le comportement élastique et plastique des verres métalliques. Dans le cadre de cette thèse, une approche de la modélisation des essais mécanique en se basant sur le modèle du volume libre a été conduite à l'aide du logiciel ZéBulon. Des travaux préliminaires pour étudier la localisation dans le cadre du volume libre ont été conduits et vont nécessiter une étude plus poussée.Mots clef : verre métallique, transition vitreuse, relaxation structurale, volume libre, caractérisation, micro-dureté, lithographie, compression, MEB in situ, modélisation.
Download or read book Contribution l tude des m canismes de plasticit et de fissuration de verres m talliques massifs written by Sovannara Hin and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Les alliages amorphes, ou verres métalliques, sont des matériaux relativement récents, datant au plus d'une cinquantaine d'années. Ils possèdent des propriétés mécaniques exceptionnelles (résistance, dureté, ténacité, énergie élastique stockée, ...) sans commune mesure avec celles de la plupart des alliages métalliques cristallins. Leur fragilité apparente en chargement uniaxial constitue toutefois un frein majeur à leur application à grande échelle et donc à leur industrialisation. Par ailleurs, les études sur le comportement à la fissuration et à la rupture des verres métalliques massifs rapportées dans la littérature sont à la fois peu nombreuses et très diverses dans leurs résultats. Face à ces problématiques, ces travaux de thèse sur les verres métalliques à base de zirconium ont deux objectifs principaux. Le premier consiste à étudier leurs mécanismes de déformation plastique par des essais hétérogènes. L'essai brésilien (ou de compression diamétrale) se révèle, dans ce contexte, efficace pour atteindre des niveaux élevés de déformation plastique à l'échelle macroscopique. Celui-ci permet également d'étudier à plus petite échelle la formation et la propagation des bandes de cisaillement et de quantifier les champs de déformation au cours du chargement par corrélation d'image. Les résultats montrent une bonne reproductibilité à ces deux échelles et offrent une meilleure estimation des déformations intenses se produisant dans les bandes de cisaillement. De plus, une identification basée sur cet essai couplé avec un autre essai hétérogène (nano-indentation) dans le but de discriminer des paramètres élastoplastiques montre qu'une loi de comportement de type von Mises n'est pas pertinente pour ce matériau. Le deuxième objectif de ces travaux vise à caractériser l'influence des défauts cristallins, liés à leur procédé d'élaboration et présents dans la matrice amorphe de nos verres métalliques, sur l'initiation et la propagation des fissures mais aussi sur leur rupture par des essais de flexion. La mesure de la ténacité et l'analyse fractographique des éprouvettes montrent que ces défauts facilitent la pré-fissuration, mais entrainent aussi une fragilisation de nos matériaux. Cette dernière propriété, i.e. la résistance à la fissuration ou ténacité, s'avère alors un bon moyen pour discriminer les différentes qualités de synthèse de ces alliages amorphes.
Download or read book Dictionary of Building and Civil Engineering written by Don Montague and published by Taylor & Francis. This book was released on 1996 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dual-language dictionary lists over 20,000 specialist terms in both French and English, covering architecture, building, engineering and property terms. It meets the needs of all building professionals working on projects overseas. It has been comprehensively researched and compiled to provide an invaluable reference source in an increasingly European marketplace.
Download or read book Terra 2008 written by Leslie Rainer and published by Getty Publications. This book was released on 2011-06-14 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: Earthen architecture constitutes one of the most diverse forms of cultural heritage and one of the most challenging to preserve. It dates from all periods and is found on all continents but is particularly prevalent in Africa, where it has been a building tradition for centuries. Sites range from ancestral cities in Mali to the palaces of Abomey in Benin, from monuments and mosques in Iran and Buddhist temples on the Silk Road to Spanish missions in California. This volume's sixty-four papers address such themes as earthen architecture in Mali, the conservation of living sites, local knowledge systems and intangible aspects, seismic and other natural forces, the conservation and management of archaeological sites, research advances, and training.
Download or read book Underground Disposal of Radioactive Wastes written by International Atomic Energy Agency and published by . This book was released on 1981 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Conceptual Basis Formalisations and Parameterization of the Stics Crop Model written by Nadine Brisson and published by Editions Quae. This book was released on 2009-01-19 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: The STICS crop model has been developed since 1996 at INRA in collaboration with other research and technical institutes. The model syntheses, illustrates and concretizes an important part of the French agronomic knowledge as a point of view on the field and cropping systems working. The formalisations of the STICS crop model presented in this book can be considered as references used in the framework of crop sciences. The book arrangement relies on the way the model designs the crop-soil system functioning, each chapter being devoted to a set of important functions such as growth initiation, yield onset, water uptake, transformation of organic matter etc. One chapter deals with the cropping system and long term simulations and the final chapter is about the involvement of the user in terms of option choices and parameterization. If this book is mainly intended for scientists who use the STICS model, it can also be useful for agronomists, crop modellers, students and technicians looking for elementary formalizations of the crop-soil system functioning.
Download or read book Properties of UO2 written by J. Belle and published by . This book was released on 1957 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Radioactive Waste Management and Regulation written by Mason Willrich and published by . This book was released on 1977 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: Discusses the nature of post-fission radioactive waste, the operations that spent fuel goes through after it is discharged from a reactor, and the problem of waste management.
Download or read book Creating Memory written by John Warkentin and published by Becker Associates. This book was released on 2010 with total page 363 pages. Available in PDF, EPUB and Kindle. Book excerpt: Toronto has over 600 public outdoor sculptures, works of art that provide a sense of the rich variety of life and work in the city, its peoples, cultures and aspirations. Interest in commissioning public sculpture began slowly in the nineteenth and early twentieth century, but increased rapidly after the 1950s.This is a book about the sculptures and how they disclose the city to itself. Creating Memory’s two introductory sections examine the factors behind this expansion over time and the changes in style as one generation of sculptors succeeded another. It looks at the reasons behind the changes as sculptures were conceived, sculpted and erected. More than 10 categories of sculptures are defined and discussed, including Founding the City, Natural Environment, Immigration, Ethnic Groups, Economic Activities, Disaster and Calamity, War And Conflict, Leaders, Ordinary Citizens, Community Life, and Works of the Imagination.
Download or read book Public Art in Vancouver written by John Steil and published by TouchWood Editions. This book was released on 2009 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Featuring more than 500 public art installations, this is the first comprehensive guidebook to explore Vancouver's urban treasures. The character of a city is revealed by the public art that neighborhoods and residents collectively place on streets and walls and in their public spaces. As a city known internationally for its breathtaking cityscapes and mountain backdrop, Vancouver has much to offer visually including the diverse and thriving public art in the city's neighborhoods. Engaging color photos and detailed descriptions that focus on the historical and cultural context of each art piece, its place in modern art and the artist who created it allow for a greater understanding of these urban treasures. Easy-to follow maps take readers to communities and destinations such as False Creek, Chinatown, the West End, Downtown, East Vancouver, VanDusen Garden, Stanley Park and the University of British Columbia. Tour the better known and the unknown art installations that are made from every possible media and include monuments, paintings, murals, tapestries, figures, First Nations art, relics, busts, fountains, gateways, mosaics, sculptures and reliefs.
Download or read book Georges Perec written by Paul Schwartz and published by Summa Publications, Inc.. This book was released on 1988 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Public Art in Canada written by Annie Gérin and published by University of Toronto Press. This book was released on 2011-03-18 with total page 706 pages. Available in PDF, EPUB and Kindle. Book excerpt: Arguably, public art is experienced daily by more people than most offerings in galleries, yet our notion of what constitutes public art is surprisingly limited. Public Art in Canada broadens the critical discussion by exploring public art's varied means of engaging with public space and the public sphere. Annie Gérin and James S. McLean have assembled contributions from new and established Canadian scholars, curators, and artists. Each contributor enlivens our understanding of public art as a practice and its place in the social and aesthetic formation of which it is a part. As a result, the book provides an overview of the current debates in the field of public art that are informed by the theories and critical literature of art history, communication studies, cultural studies, sociology, and urban studies. The rigorous essays and original works of art collected in this volume present a compelling demonstration of the strategies, aesthetic and otherwise, used by artists to elicit intellectual, sensual, or emotional responses that can only be obtained through artistic practices in public places. Public Art in Canada is a major contribution to the study of Canadian art and culture.
Download or read book Exploring Vancouver written by Harold Kalman and published by UBC Press. This book was released on 2011-11-01 with total page 297 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vancouver's streetscapes have changed drastically in recent years. New buildings representing current architectural trends are mixing with and often replacing those of earlier eras and tastes. Exploring Vancouver invites the reader to experience the city's continually evolving landscape in a readable, yet authoritative, guide.
Download or read book Metamorphoses written by Emanuele Coccia and published by John Wiley & Sons. This book was released on 2021-06-09 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: We are all fascinated by the mystery of metamorphosis – of the caterpillar that transforms itself into a butterfly. Their bodies have almost nothing in common. They don’t share the same world: one crawls on the ground and the other flutters its wings in the air. And yet they are one and the same life. Emanuele Coccia argues that metamorphosis – the phenomenon that allows the same life to subsist in disparate bodies – is the relationship that binds all species together and unites the living with the non-living. Bacteria, viruses, fungi, plants, animals: they are all one and the same life. Each species, including the human species, is the metamorphosis of all those that preceded it – the same life, cobbling together a new body and a new form in order to exist differently. And there is no opposition between the living and the non-living: life is always the reincarnation of the non-living, a carnival of the telluric substance of a planet – the Earth – that continually draws new faces and new ways of being out of even the smallest particle of its disparate body. By highlighting what joins humans together with other forms of life, Coccia’s brilliant reflection on metamorphosis encourages us to abandon our view of the human species as static and independent and to recognize instead that we are part of a much larger and interconnected form of life.
Download or read book The Poetics of Experiment written by Warren F. Motte and published by . This book was released on 1984 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Exploring Vancouverism written by Howard Rotberg and published by . This book was released on 2008 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: This insightful book challenges Vancouverites and people everywhere in their view that progressivism is tolerance and challenges us to create a richer, more values-based culture - to move from values of looking good and feeling good, to the higher value of doing good.
Download or read book A Historical Catalogue of Scientists and Scientific Books written by Robert Mortimer Gascoigne and published by Scholarly Title. This book was released on 1984 with total page 1216 pages. Available in PDF, EPUB and Kindle. Book excerpt:
