Download or read book Contribution des cyclodextrines au d veloppement de syst mes photocatalytiques base de TiO2 written by Anthony Lannoy and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: La photocatalyse hétérogène est une technique d'oxydation avancée prometteuse dans le domaine de la dépollution d'effluents aqueux ou gazeux industriels contenant des composés organiques tels que les colorants, engrais, pesticides ou composés organiques volatils (COV). La photocatalyse met en oeuvre l'excitation d'un matériau semi-conducteur par une radiation lumineuse et dans ce contexte le dioxyde de titane (TiO2) est le photocatalyseur le plus couramment employé. Cependant, son activité est liée à de nombreux paramètres (longueur d'onde d'irradiation, paramètres texturaux, composition cristalline...) qu'il convient de maitriser si on veut concevoir un système de dépollution efficace. Afin d'améliorer les performances du TiO2, différentes approches ont émergé durant les dernières décennies, telles que ledopage par des métaux de transition ou le dopage par des composés organiques.Le sujet de la thèse s'est inscrit dans ce contexte et a porté sur le développement de systèmes photocatalytiques élaborés en présence de cyclodextrines (molécules cages formées par l'enchainement d'unités glucosidiques) pour la dégradation de polluants organiques en phase aqueuse. Il s'articule en trois parties principales. La première partie a été consacrée à la possibilité de combiner directement l'action d'un dioxyde de titane commercial (P25) en suspension aqueuse en présence de cyclodextrines pour améliorer le rendement de réactions photocatalysées. Appliquée à la dégradation photocatalytique d'un COV hydrophobe (toluène) dans l'UV, l'étude n'a pas montré d'impact positif des cyclodextrines. Les résultats ont été rationnalisés par l'évaluation des capacités d'adsorption des cyclodextrines sur la surface duphotocatalyseur et des constantes d'association 1:1 CD:toluène. Le deuxième partie a porté sur la synthèse d'une série de matériaux mésoporeux TiO2 par voie sol-gel colloïdale en utilisant comme agents structurants des assemblages supramoléculaires de type Pluronic 123-cyclodextrine partiellement méthylée (micelles). L'introduction de cyclodextrine méthylée en quantité contrôlée permet de jouer sur le glonflement des micelles. Après élimination de l'agent template par calcination, il est mis en évidence qu'il est possible de moduler les paramètres texturaux et structuraux du dioxyde de titane. Ces matériaux ont été évalués dans la réaction de dégradation de l'acide phénoxyacétique en phase aqueuse sous une irradiation proche du rayonnement visible (365 nm). Dans la troisième partie, le développement de matériaux mésoporeux TiO2 par voie sol-gel colloïdale a été poursuivi en substituant les assemblages supramoléculaires comme agents structurants par des cyclodextrines seules. Les paramètres de synthèse ont été optimisés avec différentes types de cyclodextrines (natives ou modifiées) et différentes concentrations.Les meilleurs résultats en termes de dégradation photocatalytique de l'acide phénoxyacétique à 365 nm ont été obtenus avec le matériau R25-T500 préparé à partir de cyclodextrine alétoirement méthylée à 25 g/L. Enfin, l'incorporation d'or sous forme HAuCl4 durant le protocole de synthèse a même permis d'observer une augmentation de l'activité photocatalytique sous irradiation à 420 nm comparativement au catalyseur référence TiO2 P25.
Download or read book N Heterocyclic Carbenes written by Silvia Diez-Gonzalez and published by Royal Society of Chemistry. This book was released on 2016-11-04 with total page 637 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Phosphorus Compounds written by Maurizio Peruzzini and published by Springer Science & Business Media. This book was released on 2011-06-10 with total page 477 pages. Available in PDF, EPUB and Kindle. Book excerpt: Each chapter of Phosphorus Compounds: Advanced Tools in Catalysis and Material Sciences have been carefully selected by the editors in order to represent a state-of-the-art overview of how phosphorus chemistry can provide solutions in various fields of applications. The editors have assembled an international array of world-renowned scientists and each chapter is written by experts in the fields of synthetic chemistry, homogeneous catalysis, dendrimers, theoretical calculations, materials science, and medicinal chemistry with a special focus on the chemistry of phosphorus compounds. Phosphorus Compounds: Advanced Tools in Catalysis and Material Sciences is of interest to a general readership ranging from advanced university course students to experts in academia and industry.
Download or read book Biomolecular Catalysis written by Seong H. Kim and published by . This book was released on 2008 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides up-to-date reviews of nanomaterials synthesis, characterization, and applications in biomolecular catalysis. It contains useful references for researchers in this field and will be a practical guide for future researchers.
Download or read book Principles of Physical Biochemistry written by Kensal Edward Van Holde and published by Prentice Hall. This book was released on 2006 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Second Edition of Principles of Physical Biochemistry provides the most current look at the theory and techniques used in the study of the physical chemistry of biological and biochemical molecules--including discussion of mass spectrometry and single-molecule methods. As leading experts in biophysical chemistry, these well-known authors offer unique insights and coverage not available elsewhere. Physical techniques currently used by practicing biochemists, including new chapters dedicated to extended material on mass spectrometry and single-molecule methods are included. The book's streamlined organization groups all hydrodynamic methods in Chapter 5 and combines Raman spectroscopy with the spectroscopy section. Relevant problems and applications help readers develop critical-thinking skills that they can apply to real biochemical and biological situations facing professionals in the industry. Biological Macromolecules; Thermodynamics and Biochemistry; Molecular Thermodynamics; Statistical Thermodynamics; Methods for the Separation and Characterization of Macromolecules; X-Ray Diffraction; Scattering From Solutions of Macromolecules; Quantum Mechanics and Spectros© Absorption Spectros© Linear and Circular Dichroism; Emission Spectros© Nuclear Magnetic Resonance Spectros© Macromolecules in Solution: Thermodynamics and Equilibria; Chemical Equilibria Involving Macromolecules; Mass Spectrometry of Macromolecules; Single-Molecule Methods. A useful reference for biochemistry professionals or for anyone interested in learning more about biochemistry.
Download or read book Magic Bullets to Conquer Malaria written by Irwin W. Sherman and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A clear, concise discourse of 300 years of malarial drug research. Serves as a resource for microbiologists, parasitologists, pharmacologists, medicinal chemists, biochemists, physicians, and drug researchers.
Download or read book The Privileged Pincer Metal Platform Coordination Chemistry Applications written by Gerard van Koten and published by Springer. This book was released on 2015-08-27 with total page 381 pages. Available in PDF, EPUB and Kindle. Book excerpt: The series Topics in Organometallic Chemistry presents critical overviews of research results in organometallic chemistry. As our understanding of organometallic structure, properties and mechanisms increases, new ways are opened for the design of organometallic compounds and reactions tailored to the needs of such diverse areas as organic synthesis, medical research, biology and materials science. Thus the scope of coverage includes a broad range of topics in pure and applied organometallic chemistry, where new breakthroughs are being achieved that are of significance to a larger scientific audience. The individual volumes of Topics in Organometallic Chemistry are thematic. Review articles are generally invited by the volume editors.
Download or read book Dynamics and Control of Underactuated Multibody Spacecraft written by Sangbum Cho and published by . This book was released on 2002 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Filtering for Some Stochastic Processes with Discrete Observations written by Oleg V. Makhnin and published by . This book was released on 2002 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Guidance Strategies for Microburst Escape written by Atilla Dogan and published by . This book was released on 2000 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Performance Prediction of a Ducted Rocket Combustor microform written by Robert Alan Stowe and published by National Library of Canada = Bibliothèque nationale du Canada. This book was released on 2001 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fixed structure Adaptive improvement Control written by Daniel P. Scharf and published by . This book was released on 2001 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Numerical Investigation of Sound Generation in Supersonic Jet Screech written by Ted A. Manning and published by . This book was released on 1999 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Adaptive Harmonic Balance Method for Unsteady Nonlinear One Dimensional Periodic Flows written by Raymond C. Maple and published by . This book was released on 2002-09-01 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new adaptive split-domain harmonic balance computational fluid dynamics (CFD) method is developed to solve highly nonlinear time-periodic flows such as those found in turbomachinery. The basic harmonic balance CFD method transforms an unsteady time-periodic problem into a steady-state problem by assuming a solution in the form of a Fourier series in time. The new method employs a unique multi-domain split-operator solution technique to remove a large-series stability restriction present in previous harmonic balance CFD approaches. In addition, the new method adapts the frequency content to the flow, starting with a small number of Fourier frequencies and augmenting the frequency content in each cell as necessary to capture local flow physics. The method reduces compute times by allowing larger integration time steps, eliminating Fourier transforms, and reducing overall problem size. The stability and accuracy of the method are verified with solutions to the 1-D inviscid Burger's equation and 1-D Euler's equation. Accurate adapted quasi-1-D Euler solutions for a supersonic/subsonic diverging nozzle with periodic unsteady outflow conditions are generated in 86% less time than an equivalent non-adapted split-domain solution, demonstrating the performance benefit of matching frequency content to the local flow conditions.
Download or read book Engine Airframe Integration written by and published by . This book was released on 1992 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Velocity and Vorticity Fields of a Single Stream Shear Layer written by Scott Christopher Morris and published by . This book was released on 2002 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Properties of Spray Formation by Turbulent Primary Breakup written by Khaled A. Sallam and published by . This book was released on 2002 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt:
