Download or read book Effets de l irradiation sur la s paration de phase et sur la viscosit dans un verre B2O 3 PbO written by Isabelle Biron and published by . This book was released on 1988 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt: Les effets d'irradiation aux électrons sur la séparation de phase et sur la viscosité d'un verre d'oxyde binaire b#2o#3 20% pds pbo ont été étudiés en effectuant des observations in situ dans des microscopes électroniques en transmission conventionnelle (125 kev) et haute tension (1 mev). Pour cela l'échauffement local du verre sous le faisceau d'électrons a été soigneusement détermine en fonction du flux d'électrons. Alors que la composition de la phase précipites est de 43% pds pbo hors irradiation, il apparait exclusivement sous irradiation, pour un large domaine de concentration de 2 à 80% pds pbo, une séparation de phase, sous forme de particules sphériques de plomb métallique. Ces particules sont animées d'un mouvement désordonne dans tout le volume irradie ayant les caractéristiques d'un mouvement brownien. Elles coalescent au cours du temps par un mécanisme de coagulation. Ainsi le nombre de particules diminue tandis que leur taille augmente. Cette évolution est d'autant plus rapide que la température et le flux d'électrons sont élevés. Le nombre de précipités est relié à la viscosité du milieu dans lequel ils évoluent par le modèle de coagulation rapide de von smoluchowski. En utilisant cette relation on a calculé sous irradiation le coefficient de viscosité du milieu. On observe une diminution spectaculaire de la viscosité du verre sous irradiation. Celle-ci est d'autant plus importante que la température est basse et le flux d'électrons élevé: 10 ordres de grandeur à 530 k pour un flux de 1,1 10 #1#9e#/cm#2s, aux électrons de 125 kev. On a montré que ce phénomène existe en présence d'excitations électroniques seules. Dans l'hypothèse ou la diminution de la viscosité sous irradiation est provoquée par la création de défauts de types lacunaire et interstitiel, le comportement de la viscosité peut s'interpréter de façon suivante: à 125 kev, par un régime de recombinaison des défauts instables crées par radiolyse et a 1 MeV par l'élimination sur des puits de défauts dus aux déplacements atomiques induits par chocs élastiques
Download or read book Physics and Chemistry of Glasses written by and published by . This book was released on 1967 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Phase Separation in Glass written by Oleg V. Mazurin and published by Elsevier. This book was released on 1984-01-01 with total page 393 pages. Available in PDF, EPUB and Kindle. Book excerpt: Phase Separation in Glass
Download or read book Radiation effects on oxide glasses Importance of energy deposition and relaxation processes written by Anamul Haq Mir and published by . This book was released on 2015 with total page 446 pages. Available in PDF, EPUB and Kindle. Book excerpt: Le but de cette étude est de simuler par des irradiations externes le scénario complexe d’auto-irradiation dans un verre nucléaire. Des irradiations par des électrons et des ions utilisant des faisceaux d’ions simple ou double ont été réalisées sur des verres borosilicatés simples et complexes. L'irradiation aux électrons engendre un appauvrissement en ions alcalins dans les premiers microns en surface, qui conduit pour le verre simple de borosilicate de sodium à une ségrégation des unités boratés, caractéristique d’une séparation de phase. La réponse du volume du verre est différente de celle de la surface et montre une dépolymérisation du réseau vitreux d’ampleur variable selon la composition chimique. Les irradiations simple faisceau ont montré que des ions de pouvoir d’arrêt électronique supérieur à 3keVnm-1 (seuil de création de traces ioniques) simulent le dommage engendré par les noyaux de recul, alors que des d’ions de pouvoir d’arrêt nucléaire négligeable et de pouvoir d’arrêt électronique inférieur à ce seuil simulent le dommage provenant des particules alpha. Les irradiations double faisceaux ont montré que les particules alpha induisent un recuit partiel du dommage généré par les ions lourds. L’impact des flux respectifs des deux particules a été étudié. En utilisant un rapport de flux pertinent, les amplitudes des évolutions de propriétés des verres irradiés en scénario double faisceau sont en très bon accord avec les données de la littérature obtenues sur des verres dopés en actinides. Ainsi, cette étude montre l’importance et le besoin d’utiliser des scénarios d’irradiation multi-faisceaux pour comprendre les effets d’irradiation dans les verres nucléaires.
Download or read book Introduction to Glass Science and Technology written by James E Shelby and published by Royal Society of Chemistry. This book was released on 2015-11-06 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a concise and inexpensive introduction for an undergraduate course in glass science and technology. The level of the book has deliberately been maintained at the introductory level to avoid confusion of the student by inclusion of more advanced material, and is unique in that its text is limited to the amount suitable for a one term course for students in materials science, ceramics or inorganic chemistry. The contents cover the fundamental topics of importance in glass science and technology, including glass formation, crystallization, phase separation and structure of glasses. Additional chapters discuss the most important properties of glasses, including discussion of physical, optical, electrical, chemical and mechanical properties. A final chapter provides an introduction to a number of methods used to form technical glasses, including glass sheet, bottles, insulation fibre, optical fibres and other common commercial products. In addition, the book contains discussion of the effects of phase separation and crystallization on the properties of glasses, which is neglected in other texts. Although intended primarily as a textbook, Introduction to Glass Science and Technology will also be invaluable to the engineer or scientist who desires more knowledge regarding the formation, properties and production of glass.
Download or read book The Influence of Radiation and Multivalent Cation Additions on Phase Separation and Crystallization of Glass written by and published by . This book was released on 1999 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The major objectives of this proposed investigation are as follows: (1) To investigate the influence of multivalent cations on the thermodynamics and kinetics of phase separation and crystallization in simple model glasses. (2) To study the influence of a and b particle, heavy ion bombardment and g irradiation on phase separation and crystallization in simple model glasses. (3) To examine the structural changes produced by radiation just prior to the onset of phase separation and/or crystallization. (4) To develop models to explain the observed effects of multivalent cations and radiation on phase separation and crystallization. (5) To utilize the results of these experimental and modeling studies to provide guidelines for the allowed range of composition choices and processing conditions in order to avoid the formation of unwanted phases in nuclear waste disposal glasses.
Download or read book Influence Of Radiation And Multivalent Cation Additions On Phase Separation And Crystallization Of Glass written by and published by . This book was released on 2000 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The major objectives of this proposed investigation are as follows: (1) To investigate the influence of multivalent cations on the thermodynamics and kinetics of phase separation and crystallization in simple model glasses. (2) To study the influence of a and b particle, heavy ion bombardment and g irradiation on phase separation and crystallization in simple model glasses. (3) To examine the structural changes produced by radiation just prior to the onset of phase separation and/or crystallization. (4) To develop models to explain the observed effects of multivalent cations and radiation on phase separation and crystallization. (5) To utilize the results of these experimental and modeling studies to provide guidelines for the allowed range of composition choices and processing conditions in order to avoid the formation of unwanted phases in nuclear waste disposal glasses.
Download or read book Ceramic Materials written by Philippe Boch and published by John Wiley & Sons. This book was released on 2010-01-05 with total page 593 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is primarily an introduction to the vast family of ceramic materials. The first part is devoted to the basics of ceramics and processes: raw materials, powders synthesis, shaping and sintering. It discusses traditional ceramics as well as “technical” ceramics – both oxide and non-oxide – which have multiple developments. The second part focuses on properties and applications, and discusses both structural and functional ceramics, including bioceramics. The fields of abrasion, cutting and tribology illustrate the importance of mechanical properties. It also deals with the questions/answers of a ceramicist regarding electronuclear technology. As chemistry is an essential discipline for ceramicists, the book shows, in particular, what soft chemistry can contribute as a result of sol-gel methods.
Download or read book Impact of Thermal Conductivity on Energy Technologies written by Aamir Shahzad and published by BoD – Books on Demand. This book was released on 2018-09-05 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is intended to provide a deep understanding on the advanced treatments of thermal properties of materials through experimental, theoretical, and computational techniques. This area of interest is being taught in most universities and institutions at the graduate and postgraduate levels. Moreover, the increasing modern technical and social interest in energy has made the study of thermal properties more significant and exciting in the recent years. This book shares with the international community a sense of global motivation and collaboration on the subject of thermal conductivity and its wide spread applications in modern technologies. This book presents new results from leading laboratories and researchers on topics including materials, thermal insulation, modeling, steady and transient measurements, and thermal expansion. The materials of interest range from nanometers to meters, bringing together ideas and results from across the research field.
Download or read book Glasses and the Vitreous State written by Jerzy Zarzycki and published by Cambridge University Press. This book was released on 1991-07-25 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an up-to-date and comprehensive coverage of the properties of glasses as materials and of the vitreous state in general. The broad coverage of the book includes a study of the methods of studying the structure, glass classification, and electrical, optical, thermal and mechanical properties of glasses.
Download or read book Management of Radioactive Wastes from the Nuclear Fuel Cycle written by and published by . This book was released on 1976 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Glass Chemistry written by Werner Vogel and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 479 pages. Available in PDF, EPUB and Kindle. Book excerpt: Glass Chemistry is concerned with the relation of chemical composition, structure and properties of various glasses. The book has been translated from the third German edition, which serves as a textbook for university students in materials sciences and a reference book for scientists and engineers in glass science and production. The central themes of the book are the chemistry and physics of glass. Detailed knowledge of the compositional and structural facts is the basis for the systematic development of new glasses as construction and optical materials. Glass Chemistry is an interdisciplinary book on the borderlines between chemistry, physics, mineralogy and even biology and medicine. The book represents a well balanced treatment for students, scientists and engineers.
Download or read book Silicate Melts written by Sharon Webb and published by Springer. This book was released on 1997-07-17 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the experimental determination of the physical properties of silicate melts and magmas close to glass transition. Abundant new data are presented. The same type of measurement is performed on a range of melts to test the effect of composition on physical properties; and a range of different techniques are used to determine the same physical properties to illustrate the relationships between the relaxation of the melt structure and the relaxation of its physical properties. This book is of interest to experimental researchers in the discussion of data obtained from both a materials science and a geoscientific point of view.
Download or read book On Induction written by Michael 1791-1867 Faraday and published by Legare Street Press. This book was released on 2021-09-09 with total page 50 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 Conduction in Non Crystalline Materials written by Sir Nevill Mott and published by Clarendon Press. This book was released on 1993-05-20 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: This second edition deals in an elementary way with electrons in non-crystalline systems. It reflects advances in the theory of interactions in non-crystalline systems, provides a more detailed discussion of the "minimum metallic conductivity", and addresses the relevance of disorder in the new high-temperature semiconductors.
Download or read book Glass Science written by R. H. Doremus and published by Wiley-Interscience. This book was released on 1994-04 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This Second Edition of Robert H. Doremus's classic, Glass Science, has been extensively revised and updated to reflect recent advances, while retaining the pedagogical structure that made its predecessor a superb tool for both teaching and professional research. Special emphasis is placed on areas of research that have been particularly active in recent years. Two new chapters have been added: one covers chemical durability [the reaction of glass with water], which includes recent work related to corrosion of glass and radioactive waste disposal: the other concerns the reaction of gasses with glass, especially oxygen. Other new or expanded discussions cover recent advances in the structure of glass, zirconium fluoride glasses, and electrical conductivity of glass.".
Download or read book Kinetics of Geochemical Processes written by Antonio C. Lasaga and published by de Gruyter. This book was released on 1981 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume 8 of Reviews in Mineralogy deals with both descriptions of the kinetics of geochemical processes: the phenomenological and the atomistic. The former relies on macroscopic variables (e.g. temperature or concentrations) to describe the rates of
