Download or read book Structure et cristallisation de verres d oxydes simples riches en bore et en terres rares written by Hélène Trégouët and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ce travail de thèse s'intéresse à la structure de verres d'oxydes simples, riches en bore et en terre rare (TR). Cette famille de verres trouve des applications dans différents domaines, de l'optique au confinement des déchets nucléaires. Ici, nous étudions la structure de verres du système le plus simple regroupant ces deux oxydes, à savoir le binaire B2O3-TR2O3. Un intérêt particulier est porté à la composition métaborate de terre rare TRB3O6, à fusion congruente. Cette étude structurale est menée au moyen de différentes techniques spectroscopiques, notamment la RMN du solide sur les noyaux 11B et 17O, l'absorption optique de Nd3+ et la diffusion des neutrons et des rayons X, associée à de la modélisation par RMC. Nous obtenons ainsi des informations sur la structure du réseau vitreux (nature des groupements structuraux, connectivité du réseau¿) et l'environnement des ions TR3+. La tendance à la cristallisation de ces verres binaires est également étudiée, par ATD, DRX et MEB. Le second volet de ces travaux concerne le système ternaire SiO2-B2O3-TR2O3. Tout d'abord, l'étendue du domaine vitrifiable est déterminée, pour nos conditions d'élaboration, puis certains verres homogènes et transparents obtenus font l'objet d'une étude structurale, de manière analogue aux verres du système binaire. Les premiers résultats concernant la tendance à la cristallisation de ces verres sont obtenus.
Download or read book Cristallisation dans un verre d aluminosilicate de calcium written by Maike Hillers and published by . This book was released on 2007 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: La cristallisation est un phénomène qui intéresse directement les procédés d’élaboration et de formage verriers. Dans ce travail, nous étudions les mécanismes de cristallisation dans des verres du système CaO-Al2O3-SiO2-B2O3. Il s’agit d’évaluer l’effet d’un ajout progressif d’oxyde de bore et l’influence de paramètres tels que la granulométrie et la voie d’élaboration sur la croissance cristalline. Différentes techniques comme l’analyse thermique, les microscopies optique et électronique à balayage, la diffraction des rayons X et les spectroscopies Raman et RMN ont été utilisées pour caractériser la cristallisation de verres entre 0 et 10 % de B2O3.Nous avons caractérisé les phases qui cristallisent : la wollastonite, la pseudowollastonite, l’anorthite, le quartz et la cristobalite. Les températures de liquidus et de transition vitreuse diminuent avec l’ajout de bore. Les vitesses maximales de croissance diminuent également avec l’augmentation de la teneur en bore. L’étude structurale par RMN (11B, 27Al, 29Si) a révélé que la formation d’unités BO4 est favorisée avec l’ajout de bore. La mobilisation du calcium par le bore pourrait expliquer l’effet inhibiteur du bore par rapport à la croissance cristalline. Les techniques in situ de MEB et DRX en température ont apporté des informations complémentaires sur l’évolution des vitesses de croissance et sur les séquences de cristallisation : la vitesse de croissance n’est pas constante mais diminue avec le temps ; dans les verres à faibles teneurs en bore, la dernière phase cristalline à apparaître est la cristobalite, dans les verres plus riches en bore c’est l’anorthite.
Download or read book Chronique written by Saint-John Perse and published by . This book was released on 1961 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Poetic Image written by C. Day Lewis and published by Read Books Ltd. This book was released on 2013-05-31 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a very rich book of poetic criticism, focusing on the role of the 'image' in poetry. A fantastic book for any poetry fan.
Download or read book Defending Ancient Springs written by Kathleen Raine and published by . This book was released on 1996-10-01 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Creative Intuition in Art Poetry written by Jacques Maritain and published by . This book was released on 2018-08-20 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt: Creative Intuition in Art and Poetry encompasses the six lectures Jacques Maritain delivered as the inaugural lecturer in the A. W. Mellon Lectures in the Fine Arts. The book paints a rich and compelling portrait of both Maritain's own philosophy and the debates surrounding art and meaning in the twentieth century as a whole.
Download or read book Anthology of Modern French Poetry written by Cecil Arthur Hackett and published by . This book was released on 1952 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Archetypal Patterns in Poetry written by Maud Bodkin and published by . This book was released on 1963 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dialogues and a Diary written by Igor 1882-1971 Stravinsky and published by Hassell Street Press. This book was released on 2021-09-09 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work has been selected by scholars as being culturally important and is part of the knowledge base of civilization as we know it. This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. To ensure a quality reading experience, this work has been proofread and republished using a format that seamlessly blends the original graphical elements with text in an easy-to-read typeface. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Download or read book Birds written by Saint-John Perse and published by . This book was released on 2002 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: Saint-John Perse A version by Derek Mahon These are birds, pure and simple, nothing more, their truth the secret of life itself . . . Derek Mahon s previous translation work includes versions of Jaccottet (Words in the Air, 1998) and Valéry (The Seaside Cemetery, 2001). To these he now adds Birds by Saint-John Perse whose long, discursive, musical texts owe something to Rimbaud s Illuminations but are finally unique. Among twentieth-century poets Perse is remarkable for his oceanic qualities, his global reach and philosophical optimism. Birds is about birds, but also about the artistic vocation itself, Yeats s lonely impulse of delight
Download or read book Christianity and Mythology written by John Mackinnon Robertson and published by . This book was released on 1900 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Illusion and Reality written by Christopher Caudwell and published by . This book was released on 1966 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Fragments of Heraclitus written by Heraclitus and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Heraclitus of Ephesus was a pre-Socratic Greek philosopher who lived a lonely life earning him the moniker of the "Weeping Philosopher." His principal philosophy is embodied in the following statement "No man ever steps in the same river twice," in other words man faces an ever-present change in the universe. He believed in the unity of opposites, stating that "the path up and down are one and the same." According to Diogenes, Heraclitus worked on "a continuous treatise On Nature," which "was divided into three discourses, one on the universe, another on politics, and a third on theology." Only fragments of this work remain today many of which are quoted from other authors. Those fragments are presented here in a translation and with critical commentary by G. T. W. Patrick.
