Download or read book Etude par diffraction des rayons X in situ des m canismes d oxydation de l acier AISI 304 entre 800 C et 1000 C written by Noureddine Karimi and published by . This book was released on 2007 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ce travail a porté sur l'étude des mécanismes d'oxydation de l'acier AISI 304 sur une gamme de température allant de 800 à 1000°C. Nous avons examiné plus particulièrement l'influence des dépôts sol-gel de lanthane et de cérium sur les processus d'oxydation. L' apport de la spectroscopie IR a permis de mieux identifier les oxydes mixtes de type spinelle FeCrO4 et Mn1,5Cr1,5O4 et corindon Fe2O3. L'association des différentes techniques d'analyse telles que la DRX in situ, la spectroscopie IR, le MEB, l'EDS et la microscopie électronique à transmission (MET) ont permis de proposer un nouveau mécanisme d'oxydation de l'acier AISI 304 au cours de son oxydation à 1000°C. Les dépôts sol-gel de lanthane et de cérium conduisent à une diminution importante des constantes de vitesse d'oxydation. Dans le cas de l'AISI 304 recouvert d'un dépôt sol-gel d'oxyde de lanthane, la DRX in situ montre que la croissance de l'oxyde mixte LaCrO3 intervient dès le début de l'oxydation. Cet oxyde est localisé à l'interface interne et bloque la diffusion externe du fer tout en retardant la diffusion externe du manganèse. Ceci peut être dû au fait que le lanthane agit de façon synergique avec le silicium afin de bloquer la diffusion externe du fer et favoriser la formation de la chromine. Le lanthane peut aussi agir en bloquant la diffusion externe des cations métalliques au travers de la couche de chromine selon un processus de ségrégation dynamique au joint de grains. Dans le cas du dépôt sol-gel d'oxyde de cérium le régime linéaire que nous avons observé à toute température est le témoin d'un processus de croissance de la couche d'oxyde limité par la diffusion à travers une couche de CeO2 d'épaisseur constante située à l'interface externe. Dans ce cas l'absence des oxydes contenant du fer dans la couche d'oxyde permet de conclure à un effet synergique avec le silicium qui bloque la diffusion externe du fer. Les essais de cycles thermiques montrent que l'adhérence des couches d'oxyde formées en présence de dépôts sol gel ne s'en trouve pas améliorée
Download or read book Application de la diffraction des rayons X in situ l tude de l oxydation isotherme et cyclique de l acier 304L haute temp rature 800 1000 C Effet de l introduction d yttrium written by Frédéric Riffard and published by . This book was released on 2001 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Apport de la diffraction des rayons X in situ l tude de l oxydation des aciers haute temp rature written by Christophe Issartel and published by . This book was released on 2003 with total page 117 pages. Available in PDF, EPUB and Kindle. Book excerpt: La DRX in situ a été l'outil commun de trois études. Nous avons étudié les effets de l'yttrium et de son mode d'incorporation sur l'oxydation d'un alliage alumino-formeur de très haute pureté à 1100° C. L'yttrium ajouté dans la masse de l'alliage a un effet bénéfique tandis que l'yttrium ajouté sous forme de dépôt à la surface de l'alliage non. Nous avons aussi étudié l'effet du titane et du niobium sur l'oxydation à 950° d'un acier FeCr chromino-formeur. La DRX in situ montre que le titane semble s'oxyder à l'intérieur du métal aux premiers stades de l'oxydation en formant les oxydes Cr2TiO5 et TiO2 qui contribuent à une augmentation de la prise de masse des échantillons. Nous avons aussi montré que le niobium n'a pas d'influence sur l'oxydation de ce type d'acier à 950 C°. La troisième étude a porté sur l'effet de la nitruration sur l'oxydation de l'alliage 304. A 800 C°, nous avons observé une amélioration de la résistance à l'oxydation. Ce qui n'est plus vrai à 900 et 1000 C°
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 Catalysts in Petroleum Refining 1989 written by D.L. Trimm and published by Elsevier. This book was released on 1990-01-22 with total page 621 pages. Available in PDF, EPUB and Kindle. Book excerpt: These proceedings reflect the important role of catalysis in petroleum refining and the effects of factors such as environmental legislation on the industry. They also show the emergence of significant scientific expertise in the Middle East - the cradle of the oil industry. Participants from all over the world took part in the meeting and the book contains a well-balanced selection of articles from both academia and industry. Current trends in the oil industry focused attention mainly on heavy end hydrotreating, but other processes also gained their share of attention. An invaluable feature of the meeting was the two panel discussions where participants took the opportunity to obtain advance on many real and immediate problems.
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 Nanocellulose written by Jin Huang and published by John Wiley & Sons. This book was released on 2019-08-05 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensively introduces readers to the production, modifications, and applications of nanocellulose This book gives a thorough introduction to the structure, properties, surface modification, theory, mechanism of composites, and functional materials derived from nanocellulose. It also provides in-depth descriptions of plastics, composites, and functional nanomaterials specifically derived from cellulose nanocrystals, cellulose nanofibrils, and bacterial cellulose. It includes the most recent progress in developing a conceptual framework of nanocellulose, as well as its numerous applications in the design and manufacture of nanocomposites and functional nanomaterials. The book also looks at the relationship between structure and properties. Featuring contributions from many noted experts in the field, Nanocellulose: From Fundamentals to Advanced Materials examines the current status of nanocomposites based on nanocelluloses. It covers surface modification of nanocellulose in the nanocomposites development; reinforcing mechanism of cellulose nanocrystals in nanocomposites; and advanced materials based on self-organization of cellulose nanocrystals. The book studies the role of cellulose nanofibrils in nanocomposites, as well as a potential application based on colloidal properties of cellulose nanocrystals. It also offers strategies to explore biomedical applications of nanocellulose. Provides comprehensive knowledge on the topic of nanocellulose, including the preparation, structure, properties, surface modification and strategy Covers new reports on the application of nanocellulose Summarizes three kinds of nanocellulose (cellulose nanocrystals, cellulose nanofibrils, and bacterial cellulose) and their production, modification, and applications Nanocellulose: From Fundamentals to Advanced Materials is a useful resource for specialist researchers of chemistry, materials, and nanotechnology science, as well as for researchers and students of the subject.
Download or read book Flexoelectricity in Liquid Crystals written by Agnes Buka and published by World Scientific. This book was released on 2013 with total page 299 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book intends to give a state-of-the-art overview of flexoelectricity, a linear physical coupling between mechanical (orientational) deformations and electric polarization, which is specific to systems with orientational order, such as liquid crystals. Chapters written by experts in the field shed light on theoretical as well as experimental aspects of research carried out since the discovery of flexoelectricity. Besides a common macroscopic (continuum) description the microscopic theory of flexoelectricity is also addressed. Electro-optic effects due to or modified by flexoelectricity as well as various (direct and indirect) measurement methods are discussed. Special emphasis is given to the role of flexoelectricity in pattern-forming instabilities. While the main focus of the book lies in flexoelectricity in nematic liquid crystals, peculiarities of other mesophases (bent-core systems, cholesterics, and smectics) are also reviewed. Flexoelectricity has relevance to biological (living) systems and can also offer possibilities for technical applications. The basics of these two interdisciplinary fields are also summarized.
Download or read book Spectral and Total Emissivity written by Maynard P. Bauleke and published by . This book was released on 1953 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Diffusion in Materials DIMAT 2011 written by Igor Bezverkhyy and published by Trans Tech Publications Ltd. This book was released on 2012-04-12 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt: The International Conference on Diffusion in Materials (DIMAT) is the benchmark conference series for diffusion in solids. DIMAT 2011 was organized by the University of Bourgogne in association with CNRS, Dijon (France). The conference showcased new results concerning theoretical tools as well as applied research approaches. Diffusion processes affect all types of materials: nanomaterials, materials for energy, metallurgy, glasses and ceramics, but each requires its own numerical tools. Volume is indexed by Thomson Reuters CPCI-S (WoS). This volume comprises most of the contributions presented at DIMAT 2011: 4 plenary lectures delivered by famous high-level scientists plus 88 contributions in the form of keynote lectures, talks and posters.
Download or read book Industrial Application of Radioisotopes written by Gábor Földiák and published by . This book was released on 1986 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Polysaccharide Based Nanocrystals written by Jin Huang and published by John Wiley & Sons. This book was released on 2014-12-03 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polysaccharide nanocrystals can be derived from the renewable resources cellulose, chitin or starch, which makes them ideal candidates for "Green Materials Science". This versatile material class can be used in nanocomposites such as rubber or polyester, and in functional materials such as drug carriers, bio-inspired mechanically adaptive materials or membranes. Moreover, polysaccharide-based nanomaterials are environmentally friendly due to their intrinsic biodegradability. With its interdisciplinary approach the book gives a thorough introduction to extraction, structure, properties, surface modification, theory, and mechanisms of material formation of polysaccharide nanocrystals from renewable resources. In addition, it provides an in-depth description of plastics, composites, and nanomaterials from cellulose nanocrystals, chitin nanowhiskers and starch nanocrystals. The first focused, concise and coherent treatment of nanomaterials made from renewable resources such as cellulose, chitin, and starch - for scientists, engineers, graduate students and industrial researchers in the field of polymeric materials.
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 Nonlinear Optical Materials written by Jerome V. Moloney and published by Springer Science & Business Media. This book was released on 1998-08-13 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mathematical methods play a significant role in the rapidly growing field of nonlinear optical materials. This volume discusses a number of successful or promising contributions. The overall theme of this volume is twofold: (1) the challenges faced in computing and optimizing nonlinear optical material properties; and (2) the exploitation of these properties in important areas of application. These include the design of optical amplifiers and lasers, as well as novel optical switches. Research topics in this volume include how to exploit the magnetooptic effect, how to work with the nonlinear optical response of materials, how to predict laser-induced breakdown in efficient optical devices, and how to handle electron cloud distortion in femtosecond processes.
Download or read book Cellulose Nanoparticles written by Vijay Kumar Thakur and published by . This book was released on 2021-07-09 with total page 1154 pages. Available in PDF, EPUB and Kindle. Book excerpt: This two-volume set covers Cellulose Nanoparticles: Chemistry and Fundamentals and Cellulose Nanoparticles: Synthesis and Manufacturing. These books form a useful reference work for graduate students and researchers in chemistry, materials science, nanoscience and green nanotechnology.
Download or read book Traditional Conservation Practices in Africa written by Thierry Joffroy and published by . This book was released on 2005 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Power Reactor Development written by and published by . This book was released on 1960 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:
