La microscopie électronique à balayage sous environnement gazeux (MEB-EG) PDF Download

Author: Lahcen Khouchaf
Publisher:
ISBN: 9782340018068
Category :
Languages : fr
Pages : 230

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Book Description
Cet ouvrage est destiné à tous les étudiants qui suivent des formations scientifiques ou techniques en relation avec l'étude des matériaux, aux chercheurs, aux ingénieurs et techniciens de laboratoires. Il traite de l'utilisation de la microscopie électronique à balayage sous environnement gazeux (MEB-EG). Cette technique est très répandue aussi bien dans le monde académique qu'industriel. Avec les avancées dans le domaine des matériaux, il devient crucial de pouvoir étudier les matériaux dans des conditions réelles d'utilisation. Le MEB-EG est une technique de choix pour étudier tout type de matériaux et nanomatériaux quel que soit son état : sec, humide, isolant, conducteur... Cet ouvrage s'articule autour de trois parties. Une première partie concerne le fonctionnement du MEB conventionnel (MEB-C) et ses limites. La seconde partie détaille le fonctionnement du MEB-EG en relation avec la présence du gaz et ses effets. Le contenu de la troisième partie permet à l'expérimentateur de choisir les meilleures conditions pour l'imagerie et pour la microanalyse X dans le MEB-EG. Cet ouvrage est une référence pour les utilisateurs des MEB environnementaux (ESEM) et à pression variable ou contrôlée (VP-SEM, CP-SEM).

Author: Shun-Hsyung Chang
Publisher: Springer Science & Business Media
ISBN: 3319037498
Category : Technology & Engineering
Languages : en
Pages : 378

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Book Description
Advanced materials are the basis of modern science and technology. This proceedings volume presents a broad spectrum of studies of novel materials covering their processing techniques, physics, mechanics, and applications. The book is concentrated on nanostructures, ferroelectric crystals, materials and composites, materials for solar cells and also polymeric composites. Nanotechnology approaches, modern piezoelectric techniques and also latest achievements in materials science, condensed matter physics, mechanics of deformable solids and numerical methods are presented. Great attention is devoted to novel devices with high accuracy, longevity and extended possibilities to work in wide temperature and pressure ranges, aggressive media etc. The characteristics of materials and composites with improved properties opening new possibilities of various physical processes, in particular transmission and receipt of signals under water, are described.

Author: Ahmed Belasri
Publisher: Springer Nature
ISBN: 9811554447
Category : Technology & Engineering
Languages : en
Pages : 659

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Book Description
This book highlights peer reviewed articles from the 1st International Conference on Renewable Energy and Energy Conversion, ICREEC 2019, held at Oran in Algeria. It presents recent advances, brings together researchers and professionals in the area and presents a platform to exchange ideas and establish opportunities for a sustainable future. Topics covered in this proceedings, but not limited to, are photovoltaic systems, bioenergy, laser and plasma technology, fluid and flow for energy, software for energy and impact of energy on the environment.

Author: W. Petruk
Publisher: Elsevier
ISBN: 0080527337
Category : Technology & Engineering
Languages : en
Pages : 287

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Book Description
Techniques of performing applied mineralogy investigations, and applications and capabilities of recently developed instruments for measuring mineral properties are explored in this book intended for practicing applied mineralogists, students in mineralogy and metallurgy, and mineral processing engineers. The benefits of applied mineralogy are presented by using in-depth applied mineralogy studies on base metal ores, gold ores, porphyry copper ores, iron ores and industrial minerals as examples. The chapter on base metal ores includes a discussion on the effects of liberation, particle sizes and surfaces coatings of Pb, Cu, Fe, Ca and So4- on the recoveries of sphalerite, galena and chalcopyrite. The chapter on gold discusses various methods of determining the quantities of gold in different minerals, including 'invisible' gold in pyrite and arsenopyrite, so that a balance of the distribution of gold among the minerals can be calculated. This book also discusses the roles of pyrite, oxygen, moisture and bacterial (thiobacillus ferrooxidans) on reactions that produce acidic drainage from tailings piles, and summarizes currently used and proposed methods of remediation of acidic drainage.

Author: Fulvio Amato
Publisher: Academic Press
ISBN: 0128117516
Category : Medical
Languages : en
Pages : 344

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Book Description
Non-Exhaust Emissions: An Urban Air Quality Problem for Public Health comprehensively summarizes the most recent research in the field, also giving guidance on research gaps and future needs to evaluate the health impact and possible remediation of non-exhaust particle emissions. With contributions from some of the major experts and stakeholders in air quality, this book comprehensively defines the state-of-the-art of current knowledge, gaps and future needs for a better understanding of particulate matter (PM) emissions, from non-exhaust sources of road traffic to improve public health. PM is a heterogeneous mix of chemical elements and sources, with road traffic being the major source in large cities. A significant part of these emissions come from non-exhaust processes, such as brake, tire, road wear, and road dust resuspension. While motor exhaust emissions have been successfully reduced by means of regulation, non-exhaust emissions are currently uncontrolled and their importance is destined to increase and become the dominant urban source of particle matter by 2020. Nevertheless, current knowledge on the non-exhaust emissions is still limited. This is an essential book to researchers and advanced students from a broad range of disciplines, such as public health, toxicology, atmospheric sciences, environmental sciences, atmospheric chemistry and physics, geochemistry, epidemiology, built environment, road and vehicle engineering, and city planning. In addition, European and local authorities responsible for air quality and those in the industrial sectors related to vehicle and brake manufacturing and technological remediation measures will also find the book valuable. - Acts as the first book to explore the health impacts of non-exhaust emissions - Authored by experts from several sectors, including academia, industry and policy - Gathers the relevant body of literature and information, defining the current knowledge, gaps and future needs

Author: Enrique Balech
Publisher:
ISBN:
Category : Alexandrium Halim
Languages : en
Pages : 172

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Author: Ludvig Landälv
Publisher: Linköping University Electronic Press
ISBN: 9176850889
Category :
Languages : en
Pages : 42

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The state-of-the-art tools for machining metals are primarily based on a metal-ceramic composite (WC-Co) coated with different combinations of carbide, nitride, and oxide coatings. Combinations of these coating materials are optimized to withstand specific wear conditions. Oxide coatings, mainly α-Al2O3, are especially desired because of their high hot-hardness, chemical inertness with respect to the workpiece, and their low friction. The search for possible alloy elements, which may facilitate the deposition of such oxides by means of physical vapor deposition (PVD) techniques, has been the goal of this thesis. The sought alloy should form thermodynamically stable or metastable compounds, compatible with the temperature of use in metal cutting application. This thesis deals with process development and coating characterization of such new oxide alloy thin films, focusing on the Al-V-O, Al-Cr-Si-O, and Cr-Zr-O systems. Alloying aluminum oxide with iso-valent vanadium is a candidate for forming the desired alloys. Therefore, coatings of (Al1-xVx)2O3, with x ranging from 0 to 1, were deposited with reactive sputter deposition. X-ray diffraction showed three different crystal structures depending on V-metal fraction in the coating: α-V2O3 rhombohedral structure for 100 at.% V, a defect spinel structure for the intermediate region, (63 - 42 at.% V), and a gamma-alumina-like solid solution at lower V-content, (18 and 7 at.%), were observed, the later was shifted to larger d-spacing compared to the pure γ-Al2O3 sample obtained if deposited with only Al-target. Annealing the Al-rich coatings in air resulted in formation of V2O5 crystals on the surface of the coating after annealing to 500 °C for 42 at.% V and 700 °C for 18 at.% V metal fraction respectively. The highest thermal stability was shown for pure γ-Al2O3-coating which transformed to α-Al2O3 after annealing to 1100° C. Highest hardness was observed for the Al-rich oxides, ~24 GPa. The hardness then decreases with increasing V-content, larger than 7 at.% V metal fraction. Doping the Al2O3 coating with 7 at.% V resulted in a significant surface smoothening compared to the binary oxide. The measured hardness after annealing in air decreased in conjunction with the onset of further oxidation of the coatings. This work increases the understanding of this complicated material system with respect to possible phases formed with pulsed DC magnetron sputtering deposition as well as their response to annealing in air. The inherent difficulties of depositing insulating oxide films with PVD, requiring a closed electrical circuit, makes the investigation of process stability an important part of this research. In this context, I investigated the influence of adding small amount of Si in Al-Cr cathode on the coating properties in a pulsed DC industrial cathodic arc system and the plasma characteristics, process parameters, and coating properties in a lab DC cathodic arc system. Si was chosen here due to a previous study showing improved erosion behavior of Al-Cr-Si over pure Al-Cr cathode without Si incorporation in the coating. The effect of Si in the Al-Cr cathode in the industrial cathodic arc system showed slight improvements on the cathode erosion but Si was found in all coatings where Si was added in the cathode. The Si addition promoted the formation of the B1-like metastable cubic oxide phase and the incorporation led to reduced or equal hardness values compared to the corresponding Si-free processes. The DC-arc plasma study on the same material system showed only small improvements in the cathode erosion and process stability (lower pressure and cathode voltage) when introducing 5 at.% Si in the Al70Cr30-cathode. The presence of volatile SiO species could be confirmed through plasma analysis, but the loss of Si through these species was negligible, since the coating composition matched the cathode composition also under these conditions. The positive effect of added Si on the process stability at the cathode surface, should be weighed against Si incorporation in the coating. This incorporation seems to lead to a reduction in mechanical properties in the as-deposited coatings and promote the formation of a B1-like cubic metastable oxide structure for the (Al,Cr)2O3 oxide. This formation may or may not be beneficial for the final application since literature indicates a slight stabilization of the metastable phase upon Si-incorporation, contrary to the effect of Cr, which stabilizes the α-phase. The thermal stability of alloys for metal cutting application is crucial for their use. Previous studies on another alloy system, Cr-Zr-O, had shown solid solution, for Cr-rich compositions in that material system, in the sought corundum structure. The thermal stability of α-Cr0.28Zr0.10O0.61 coating deposited by reactive radio frequency (RF)-magnetron sputtering at 500 °C was therefore investigated here after annealing in vacuum up to 870 °C. The annealed samples showed transformation of α-(Cr,Zr)2O3 and amorphous ZrOx-rich areas into tetragonal ZrO2 and bcc-Cr. The instability of the α-(Cr,Zr)2O3 is surprising and possibly related to the annealing being done under vacuum, facilitating the loss of oxygen. Further in situ synchrotron XRD annealing studies on the α-Cr0.28Zr0.10O0.61 coating in air and in vacuum showed increased stability for the air annealed sample up to at least 975 °C, accompanied with a slight increase in ex-situ measured nanohardness. The onset temperature for formation of tetragonal ZrO2 was similar to that for isothermally vacuum annealing. The synchrotron-vacuum annealed coating again decomposed into bcc-Cr and t-ZrO2, with an addition of monoclinic–ZrO2 due to grain growth. The stabilization of the room temperature metastable tetragonal ZrO2 phase, due to surface energy effects present with small grains sizes, may prove to be useful for metal cutting applications. The observed phase segregation of α-(Cr,Zr)2O3 and formation of tetragonal ZrO2 with corresponding increase in hardness for this pseudobinary oxide system also opens up design routes for pseudobinary oxides with tunable microstructural and mechanical properties.

Author: J. Belle
Publisher:
ISBN:
Category : Nuclear fuels
Languages : en
Pages : 146

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Author: World Intellectual Property Organization
Publisher: WIPO
ISBN: 9280530542
Category : Law
Languages : en
Pages : 191

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This Guide is primarily intended for applicants and holders of international registrations of marks, as well as officials of the competent administrations of the Member States of the Madrid Union. It leads them through the various steps of the international registration procedure and explains the essential provisions of the Madrid Agreement, the Madrid Protocol and the Common Regulations.

Author: Ursula Jakob
Publisher: Springer Science & Business Media
ISBN: 9400757875
Category : Science
Languages : en
Pages : 488

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Book Description
Many physiological conditions such as host defense or aging and pathological conditions such as neurodegenerative diseases, and diabetes are associated with the accumulation of high levels of reactive oxygen species and reactive nitrogen species. This generates a condition called oxidative stress. Low levels of reactive oxygen species, however, which are continuously produced during aerobic metabolism, function as important signaling molecules, setting the metabolic pace of cells and regulating processes ranging from gene expression to apoptosis. For this book we would like to recruit the experts in the field of redox chemistry, bioinformatics and proteomics, redox signaling and oxidative stress biology to discuss how organisms achieve the appropriate redox balance, the mechanisms that lead to oxidative stress conditions and the physiological consequences that contribute to aging and disease.