Download or read book Nitration aromatique sur catalyseurs acides solides written by Toufiq Akouz and published by . This book was released on 1991 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: LA NITRATION DES COMPOSES AROMATIQUES EN PHASE GAZEUSE PAR LE PEROXYDE D'AZOTE EST CATALYSEE PAR LES SILICOALUMINATES AMORPHES (SILICE-ALUMINE) OU CRYSTALLISES (ZEOLITHES). LES RESULTATS CINETIQUES SONT EN ACCORD AVEC UN MECANISME PAR TRANSFERT MONOELECTRONIQUE CONDUISANT A UN RADICAL CATION AROMATIQUE INTERMEDIAIRE. L'ETUDE COMPARATIVE DE DIVERS CATALYSEURS MONTRE QUE L'ACTIVITE EST LIEE AU NOMBRE ET A LA FORCE DES SITES ACIDES AINSI QU'A LEUR ACCESSIBILITE. L'ADDITION DE VAPEUR D'EAU AMELIORE LA STABILITE DES CATALYSEURS AINSI QUE L'ACTIVITE DES ZEOLITHES MAIS DIMINUE L'ACTIVITE DE LA SILICE ALUMINE. LA STRUCTURE DES ZEOLITHES N'A PAS D'EFFET SUR LA SELECTIVITE DE POSITION ORTHO, META, PARA

Download or read book Catalyse acido basique written by Christian Marcilly and published by TECHNIP OPHRYS EDITIONS. This book was released on 2003 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book ETUDE COMPARATIVE DES ECHANGES 1H 2H ENTRE DIVERS CATALYSEURS ACIDES SOLIDES ET L ISOBUTANE DOSAGE DES SITES ACIDES DE PAR RMN written by DAVID.. HABERMACHER and published by . This book was released on 1999 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: AU COURS DE CE TRAVAIL NOUS AVONS PU CONFIRMER QUE LA REGIOSPECIFICITE DE L'ECHANGE H/D ENTRE LES ACIDES SOLIDES FORTS DEUTERES ET LES ALCANES LEGERS CONCERNAIT UNIQUEMENT LES PROTONS EN ALPHA DU CARBONE RAMIFIE. LE PROCESSUS D'ECHANGE APPARAIT APRES L'IONISATION DE L'ALCANE ET S'EFFECTUE PAR UNE SERIE DE REPROTONATIONS/DEPROTONATIONS IMPLIQUANT DES IONS CARBENIUMS ADSORBES ET DES ALCENES INTERMEDIAIRES. UNE METHODE QUANTITATIVE DE TITRATION DES SITES ACIDES DE BRNSTED A ETE DEVELOPPEE, BASEE D'UNE PART SUR LA QUANTITE D'ECHANGE H/D ENTRE L'EAU DEUTEREE ET LE SOLIDE ACIDE, D'AUTRE PART SUR LA TITRATION RETOUR BASEE SUR L'ECHANGE H/D ENTRE L'ACIDE SOLIDE DEUTERE ET L'ISOBUTANE. LE POINT FORT DE CETTE METHODE CONTRAIREMENT AUX AUTRES METHODES DE TITRATION BASEES SUR L'ADSORPTION, EST QU'ELLE DOSE UNIQUEMENT LES SITES DE BRNSTED CATALYTIQUEMENT ACTIFS. ELLE A PERMIS DE CARACTERISER AVEC SUCCES L'ACIDITE DE LA ZIRCONE SULFATEE, D'HETEROPOLYACIDES ET DE ZEOLITHES VARIEES COMME LA H-BEA, H-USY ET LA H-SAPO-5. D'AUTRE PART ELLE A PERMIS D'ETUDIER LE ROLE INHIBITEUR DU MONOXYDE DE CARBONE SUR L'ECHANGE ET AINSI D'APPORTER DE NOUVELLES INFORMATIONS SUR LE MECANISME DE CETTE REACTION. LE CARACTERE POSITIF DE L'HYDROGENE A PAR AILLEURS ETE MIS EN EVIDENCE. IL A AUSSI ETE VU QUE LES TRACES D'ALCENES PRESENTES DANS L'ISOBUTANE N'INFLUAIENT AUCUNEMENT SUR LA REACTION ET QU'IL EN FALLAIT PLUSIEURS POURCENTS DANS L'ALCANE POUR QUE LA CINETIQUE DE L'ECHANGE EN SOIT MODIFIEE.

Download or read book La Catalyse en chimie organique written by Paul Sabatier and published by Nouveau Monde éditions. This book was released on 2014-01-01 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: Réputé pour être l'un des plus grands chimistes du XXe siècle et lauréat du prix Nobel de chimie en 1912, Paul Sabatier est, par ses découvertes, à l'origine de progrès fondamentaux en chimie organique. Il apporta notamment une contribution majeure à la compréhension de la catalyse, à travers l'étude du rôle et des fonctions que peuvent jouer les substances chimiques, et en proposa un mécanisme général. Il nous offre, dans cet ouvrage, une synthèse claire et complète de ses travaux pionniers et de sa découverte de l'hydrogénation catalytique. Elle reste l'étude de référence sur ce phénomène chimique à l'origine de nombreux développements industriels et dont les potentialités sont encore considérables.

Download or read book Alkylation des aromatiques par les alcools sur des catalyseurs z olithiques acides written by Monique Lambret and published by . This book was released on 1990 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: LA DISMUTATION DU TOLUENE EN BENZENE ET XYLENES, AINSI QUE L'ALKYLATION DU BENZENE ET DU TOLUENE PAR L'ETHANOL ONT ETE ETUDIES SUR DES CATALYSEURS ZEOLITHIQUES ACIDES. LA DISMUTATION DU TOLUENE APPARAIT COMME ETANT CATALYSEE PAR LES SITES ACIDES FORTS. SUR MORDENITE LA SELECTIVITE DEPEND SEULEMENT DE LA CONVERSION ET EST INDEPENDANTE DE LA QUANTITE DE COKE ET DU CONTENU EN ALUMINIUM DE LA ZEOLITHE. IL EST DONC CONCLU QUE LE PARAXYLENE EST LE PRODUIT PRIMAIRE DE LA REACTION, ET QUE LA SELECTIVITE NE DEPEND PAS DE LA FORCE DES SITES ACIDES DU SOLIDE. LES RESULTATS SUR OFFRETITE SUGGERENT QUE LA SELECTIVITE EST DETERMINEE DANS CE CAS PAR DES CONTRAINTES STERIQUES SUR L'ETAT DE TRANSITION. DANS L'ALKYLATION DU TOLUENE PAR L'ETHANOL, LA COKEFACTION AFFECTE PRINCIPALEMENT LA DISMUTATION. LES DEUX REACTIONS D'ALKYLATION ET DE DISMUTATION SUIVENT UN MECANISME D'ELEY RIDEAL. LA DISMUTATION EST EN PARTIE INHIBEE PAR L'ETHANOL OU L'EAU PRODUITE PAR SA DEHYDRATATION. CET EFFET EST PLUS IMPORTANT SUR LES SOLIDES RICHES EN AL, CE QUI SUGGERE UNE INTERVENTION DE L'HYDROPHOBICITE DU SOLIDE. LA REACTION PRODUIT DES XYLENES ET DES ETHYLTOLUENES, ET IL EST REMARQUABLE D'OBSERVER QUE TANDIS QUE LA SELECTIVITE EN PARAXYLENE ATTEINT 86%, LES ETHYLTOLUENES SONT EN EQUILIBRE SUR TOUTES LES ZEOLITHES SAUF LA ZSM5. LA PLUS HAUTE SELECTIVITE EN PARAXYLENE DANS L'ALKYLATION EST RELIEE A LA DECROISSANCE DE LA CONVERSION PAR L'INHIBITION DE LA REACTION PAR L'ETHANOL OU L'EAU. LES CONTRAINTES STERIQUES SONT CEPENDANT IMPORTANTES POUR LA FORMATION SELECTIVE DU PARA ETHYLTOLUENE

Download or read book A German English Dictionary for Chemists written by Austin M 1876-1956 Patterson and published by Scholar Select. This book was released on 2015-08-08 with total page 340 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 was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work. 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.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. 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 Actes Et Documents written by and published by . This book was released on 1955 with total page 460 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Petrochemicals products written by Alberto Barbier and published by . This book was released on 1955 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings written by and published by . This book was released on 1956 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Annual tables of constants and numerical data chemical physical and technological written by and published by . This book was released on 1922 with total page 808 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Cancer written by L. Tomatis and published by . This book was released on 1990 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive volume presents the available evidence on the preventability of cancer. It describes the occurrence of, and variations in the different forms of cancer, as well as information on risk factors causally associated with cancer in humans, estimating the extent to which death from cancer at specific body sites can be prevented. The book outlines the methods of descriptive epidemiology, reviews the categories of carcinogenic agents, and examines the effects of screening and the possibilities of primary prevention.

Download or read book Gazette Du Bureau Des Brevets written by Canada. Patent Office and published by . This book was released on 1984 with total page 1198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Includes annual cumulative index of inventors and patentees.

Download or read book Ruthenium Catalysts and Fine Chemistry written by Christian Bruneau and published by Springer Science & Business Media. This book was released on 2004-06-30 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: With contributions by numerous experts

Download or read book Light Water Hydrogen written by CRAIG GRIMES and published by Springer Science & Business Media. This book was released on 2007-12-03 with total page 561 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the field of solar production of hydrogen by water photo-splitting (photoelectrolysis) using semiconductor photoanodes. The emphasis of the discussion is on the use of nanotechnology in the field. The theories behind photocatalysis and photoelectrochemical processes responsible for hydrogen production are given in detail. This provides a state-of-the-art review of the semiconductor materials and methods used for improving the efficiency of the processes. The book also gives an account of the techniques used for making the nanostructures.

Download or read book The Kyoto Protocol written by Sebastian Oberthür and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 369 pages. Available in PDF, EPUB and Kindle. Book excerpt: The adoption of the Kyoto Protocol in December 1997 was a major achievement in the endeavour to tackle the problem of global climate change at the dawn of the 21st century. After many years of involvement in the negotiation process, the book's two internationally recognised authors now offer the international community a first hand and inside perspective of the debate on the Kyoto Protocol. The book provides a comprehensive scholarly analysis of the history and content of the Protocol itself as well as of the economic, political and legal implications of its implementation. It also presents a perspective for the further development of the climate regime. These important features make this book an indispensable working tool for policy makers, negotiators, academics and all those actively involved and interested in climate change issues in both the developed and developing world.

Download or read book Green Metathesis Chemistry written by Valerian Dragutan and published by Springer Science & Business Media. This book was released on 2009-10-26 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: An outstanding international scientific event in the field of metathesis chemistry, the NATO ASI "Green Metathesis Chemistry: Great Challenges in Synthesis, Catalysis and Nanotechnology" has been recently organized in Bucharest, Romania (July 21- August 2, 2008). Numerous renowned scientists, young researchers and students, convened for two weeks to present and debate on the newest trends in alkene metathesis and identify future perspectives in this fascinating area of organic, organometallic, catalysis and polymer chemistry with foreseen important applications in materials science and technology. Following the fruitful practice of NATO Advanced Study Institutes, selected contributions covering plenary lectures, short communications and posters have been compiled in this special volume dedicated to this successful convention on green metathesis chemistry. General interest was primarily focused on relevant "green chemistry" features related to all types of metathesis reactions (RCM, CM, enyne metathesis, ADMET and ROMP). Diverse opportunities for green and sustainable technologies and industrial procedures based on metahesis have been identified. Largely exemplified was the utility of this broadly applicable strategy in organic synthesis, for accessing natural products and pharmaceuticals, and also its ability to fit in the manufacture of smart and nanostructured materials, self-assemblies with nanoscale morphologies, macromolecular engineering.

Download or read book Essentials in Modern HPLC Separations written by Serban C. Moldoveanu and published by Elsevier. This book was released on 2022-06-24 with total page 718 pages. Available in PDF, EPUB and Kindle. Book excerpt: Essentials in Modern HPLC Separations, Second Edition discusses the role of separation in high performance liquid chromatography (HPLC). This new and updated edition systematically presents basic concepts as well as new developments in HPLC. Starting with a description of basic concepts, it provides important guidance for the practical utilization of various HPLC procedures, such as the selection of the HPLC type, proper choice of the chromatographic column, selection of mobile phase and selection of the method of detection, all of which are in correlation with the physico-chemical characteristics of the compounds separated. Every chapter has been carefully reviewed, with several new sections added to bring the book completely up-to-date. Hence, it is a valuable reference for students and professors in chemistry. - Provides a thoroughly updated resource, with an entirely new section on Computer-aided Method Development in HPLC and new subsections on miniaturization and automation in HPLC, chemometric aspects of HPLC, green solvent use in HPLC, and more - Includes insights into the chromatographic process to find the optimum solution for analyzing complex samples - Presents a basis for understanding the utilization of modern HPLC for applications, particularly for the analysis of pharmaceutical, biological, food, beverage and environmental samples