Elaboration et caractérisation de matériaux Si-M-C-N (M

Elaboration et caractérisation de matériaux Si-M-C-N (M PDF Author: David Lopez Ferber
Publisher:
ISBN:
Category :
Languages : fr
Pages : 0

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Book Description
La limitation de notre impact environnemental passe en partie par la recherche et le développement de nouveaux procédés et matériaux, et les céramiques techniques ont une place essentielle parmi ceux-ci. Les composites à matrices céramiques (CMCs) permettent le renfort de nombreux types de structures, principalement pour des applications à hautes températures, et notamment dans les turbomachines. Ces CMCs utilisent majoritairement des fibres de carbure de silicium (SiC) en tant qu'agent de renfort. Toutefois, le marché des fibres de SiC est dominé par le Japon. Cet oligopole conduit à des problématiques économiques et stratégiques. De plus, les performances thermomécaniques des fibres SiC se dégradent dès 1400 °C en conditions d'utilisation. Dès lors, il apparaît que l'amélioration des performances des CMCs pourra résider dans la substitution du SiC par d'autres systèmes compositionnels plus stables en température. Dans le cadre de cette thèse, les systèmes quaternaires Si-B-C-N et Si-Al-C-N ont été envisagés en substitution du SiC pour leurs performances thermiques et chimiques de premier plan. La voie PDCs (Polymer-Derived Ceramics) a permis d'ajuster la composition des précurseurs à l'échelle moléculaire. La modularité de cette méthode d'élaboration de céramiques réside dans la possibilité de mettre en forme à façon les précurseurs, permettant la synthèse d'objets, dont des fibres, qui ne sont pas accessibles par les méthodes conventionnelles de synthèses. L'élaboration de fibres creuses de large diamètre pour des applications catalytiques ou membranaires est envisagée en complément des fibres micrométriques pour du renforcement de structures. Dans le cadre de ces travaux de thèse, la synthèse de nouveaux précurseurs à façon a été étudiée en couplant différentes techniques de caractérisation des polymères. La conversion polymère-céramique (1000 °C) a également été suivie à l'aide de méthodes de caractérisation dites ex-situ et in-situ afin d'identifier les mécanismes de pyrolyse liés à cette transformation. L'évolution microstructurale des céramiques obtenues à 1000 °C a quant à elle été caractérisée par spectroscopies RMN, Raman et IRTF ainsi que par DRX, MEB-EDX et MET afin d'identifier l'effet de la teneur en bore, voire en aluminium, des céramiques sur la structuration du système Si-C-N. La capacité au filage de précurseurs sélectionnés dans les chapitres 3, 4 et 5 a été étudiée et discutée.

Elaboration et caractérisation de matériaux Si-M-C-N (M

Elaboration et caractérisation de matériaux Si-M-C-N (M PDF Author: David Lopez Ferber
Publisher:
ISBN:
Category :
Languages : fr
Pages : 0

Get Book Here

Book Description
La limitation de notre impact environnemental passe en partie par la recherche et le développement de nouveaux procédés et matériaux, et les céramiques techniques ont une place essentielle parmi ceux-ci. Les composites à matrices céramiques (CMCs) permettent le renfort de nombreux types de structures, principalement pour des applications à hautes températures, et notamment dans les turbomachines. Ces CMCs utilisent majoritairement des fibres de carbure de silicium (SiC) en tant qu'agent de renfort. Toutefois, le marché des fibres de SiC est dominé par le Japon. Cet oligopole conduit à des problématiques économiques et stratégiques. De plus, les performances thermomécaniques des fibres SiC se dégradent dès 1400 °C en conditions d'utilisation. Dès lors, il apparaît que l'amélioration des performances des CMCs pourra résider dans la substitution du SiC par d'autres systèmes compositionnels plus stables en température. Dans le cadre de cette thèse, les systèmes quaternaires Si-B-C-N et Si-Al-C-N ont été envisagés en substitution du SiC pour leurs performances thermiques et chimiques de premier plan. La voie PDCs (Polymer-Derived Ceramics) a permis d'ajuster la composition des précurseurs à l'échelle moléculaire. La modularité de cette méthode d'élaboration de céramiques réside dans la possibilité de mettre en forme à façon les précurseurs, permettant la synthèse d'objets, dont des fibres, qui ne sont pas accessibles par les méthodes conventionnelles de synthèses. L'élaboration de fibres creuses de large diamètre pour des applications catalytiques ou membranaires est envisagée en complément des fibres micrométriques pour du renforcement de structures. Dans le cadre de ces travaux de thèse, la synthèse de nouveaux précurseurs à façon a été étudiée en couplant différentes techniques de caractérisation des polymères. La conversion polymère-céramique (1000 °C) a également été suivie à l'aide de méthodes de caractérisation dites ex-situ et in-situ afin d'identifier les mécanismes de pyrolyse liés à cette transformation. L'évolution microstructurale des céramiques obtenues à 1000 °C a quant à elle été caractérisée par spectroscopies RMN, Raman et IRTF ainsi que par DRX, MEB-EDX et MET afin d'identifier l'effet de la teneur en bore, voire en aluminium, des céramiques sur la structuration du système Si-C-N. La capacité au filage de précurseurs sélectionnés dans les chapitres 3, 4 et 5 a été étudiée et discutée.

Advanced Materials

Advanced Materials PDF 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.

ICREEC 2019

ICREEC 2019 PDF 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.

Calorimetry and Thermal Methods in Catalysis

Calorimetry and Thermal Methods in Catalysis PDF Author: Aline Auroux
Publisher: Springer Science & Business Media
ISBN: 3642119549
Category : Technology & Engineering
Languages : en
Pages : 569

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Book Description
The book is about calorimetry and thermal analysis methods, alone or linked to other techniques, as applied to the characterization of catalysts, supports and adsorbents, and to the study of catalytic reactions in various domains: air and wastewater treatment, clean and renewable energies, refining of hydrocarbons, green chemistry, hydrogen production and storage. The book is intended to fill the gap between the basic thermodynamic and kinetics concepts acquired by students during their academic formation, and the use of experimental techniques such as thermal analysis and calorimetry to answer practical questions. Moreover, it supplies insights into the various thermal and calorimetric methods which can be employed in studies aimed at characterizing the physico-chemical properties of solid adsorbents, supports and catalysts, and the processes related to the adsorption desorption phenomena of the reactants and/or products of catalytic reactions. The book also covers the basic concepts for physico-chemical comprehension of the relevant phenomena. Thermodynamic and kinetic aspects of the catalytic reactions can be fruitfully investigated by means of thermal analysis and calorimetric methods, in order to better understand the sequence of the elemental steps in the catalysed reaction. So the fundamental theory behind the various thermal analysis and calorimetric techniques and methods also are illustrated.

Faecal Sludge Management

Faecal Sludge Management PDF Author: Linda Strande
Publisher: IWA Publishing
ISBN: 1780404735
Category : Technology & Engineering
Languages : en
Pages : 428

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Book Description
It is estimated that literally billions of residents in urban and peri-urban areas of Africa, Asia, and Latin America are served by onsite sanitation systems (e.g. various types of latrines and septic tanks). Until recently, the management of faecal sludge from these onsite systems has been grossly neglected, partially as a result of them being considered temporary solutions until sewer-based systems could be implemented. However, the perception of onsite or decentralized sanitation technologies for urban areas is gradually changing, and is increasingly being considered as long-term, sustainable options in urban areas, especially in low- and middle-income countries that lack sewer infrastructures. This is the first book dedicated to faecal sludge management. It compiles the current state of knowledge of the rapidly evolving field of faecal sludge management, and presents an integrated approach that includes technology, management, and planning based on Sandecs 20 years of experience in the field. Faecal Sludge Management: Systems Approach for Implementation and Operation addresses the organization of the entire faecal sludge management service chain, from the collection and transport of sludge, and the current state of knowledge of treatment options, to the final end use or disposal of treated sludge. The book also presents important factors to consider when evaluating and upscaling new treatment technology options. The book is designed for undergraduate and graduate students, and engineers and practitioners in the field who have some basic knowledge of environmental and/or wastewater engineering.

Zeolite Microporous Solids: Synthesis, Structure, and Reactivity

Zeolite Microporous Solids: Synthesis, Structure, and Reactivity PDF Author: E.G. Derouane
Publisher: Springer Science & Business Media
ISBN: 9401126046
Category : Science
Languages : en
Pages : 635

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Book Description
Intensive research on zeolites, during the past thirty years, has resulted in a deep understanding of their chemistry and in a true zeolite science, including synthesis, structure, chemical and physical properties, and catalysis. These studies are the basis for the development and growth of several industrial processes applying zeolites for selective sorption, separation, and catalysis. In 1983, a NATO Advanced Study Institute was organized in Alcabideche (portugal) to establish the State-of-the-Art in Zeolite Science and Technology and to contribute to a better understanding of the structural properties of zeolites, the configurational constraints they may exert, and their effects in adsorption, diffusion, and catalysis. Since then, zeolite science has witnessed an almost exponential growth in published papers and patents, dealing with both fundamentals issues and original applications. The proposal of new procedures for zeolite synthesis, the development of novel and sophisticated physical techniques for zeolite characterization, the discovery of new zeolitic and related microporous materials, progresses in quantum chemistry and molecular modeling of zeolites, and the application of zeolites as catalysts for organic reactions have prompted increasing interest among the scientific community. An important and harmonious interaction between various domains of Physics, Chemistry, and Engineering resulted therefrom.

Dynamic Behavior of Materials, Volume 1

Dynamic Behavior of Materials, Volume 1 PDF Author: Bo Song
Publisher: Springer
ISBN: 3319224522
Category : Technology & Engineering
Languages : en
Pages : 265

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Book Description
Dynamic Behavior of Materials, Volume 1 represents the first of nine volumes of technical papers presented at the Society for Experimental Mechanics SEM 15th International Congress & Exposition on Experimental and Applied Mechanics, held at Costa Mesa, California, June 8-11, 2015. The full set of proceedings also includes volumes on: Challenges in Mechanics of Time Dependent Materials, Advancement of Optical Methods in Experimental Mechanics, Experimental and Applied Mechanics 16th International Symposium on MEMS and Nanotechnology, 5th International Symposium on the Mechanics of Biological Systems and Materials, International Symposium on the Mechanics of Composite and Multi-functional Materials, Fracture, Fatigue, Failure and Damage Evolution; and Residual Stress, Thermomechanics & Infrared Imaging, Hybrid Techniques and Inverse Problems.

Fertilizer and Plant Nutrition Guide

Fertilizer and Plant Nutrition Guide PDF Author:
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 200

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Book Description
Handboek samengesteld door "the Fertilizer Association of India (FAI)"

Plasma Polymer Films

Plasma Polymer Films PDF Author: Hynek Biederman
Publisher: World Scientific
ISBN: 1860944671
Category : Technology & Engineering
Languages : en
Pages : 391

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Book Description
Plasma Polymer Films examines the current status of the deposition and characterization of fluorocarbon-, hydrocarbon- and silicon-containing plasma polymer films and nanocomposites, with plasma polymer matrix. It introduces plasma polymerization process diagnostics such as optical emission spectroscopy (OES, AOES), and describes special deposition techniques such as atmospheric pressure glow discharge. Important issues for applications such as degradation and stability are treated in detail, and structural characterization, basic electrical and optical properties and biomedical applications are discussed.

N-Heterocyclic Carbenes

N-Heterocyclic Carbenes PDF Author: Silvia Diez-Gonzalez
Publisher: Royal Society of Chemistry
ISBN: 1782626816
Category : Science
Languages : en
Pages : 637

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Book Description
In less than 20 years N-heterocyclic carbenes (NHCs) have become well-established ancillary ligands for the preparation of transition metal-based catalysts. This is mainly due to the fact that NHCs tend to bind strongly to metal centres, avoiding the need of excess ligand in catalytic reactions. Also, NHC‒metal complexes are often insensitive to air and moisture, and have proven remarkably resistant to oxidation. This book showcases the wide variety of applications of NHCs in different chemistry fields beyond being simple phosphine mimics. This second edition has been updated throughout, and now includes a new chapter on NHC‒main group element complexes. It covers the synthesis of NHC ligands and their corresponding metal complexes, as well as their bonding and stereoelectronic properties and applications in catalysis. This is complemented by related topics such as organocatalysis and biologically active complexes. Written for organic and inorganic chemists, this book is ideal for postgraduates, researchers and industrialists.