Download or read book Elaboration de charbons actifs texture contr l e written by Benoît Cagnon and published by . This book was released on 2002 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ce travail de thèse est consacré à deux grandes voies d'optimisation des propriétés microporeuses des charbons actifs. Le contrôle de la texture poreuse des charbons actifs, pendant leur élaboration, par activation à la vapeur d'eau à partir de coques de noix de coco a été étudié. D'abord, l'étude cinétique et l'étude des effets des paramètres de l'étape de carbonisation ont été entrepris dans le but de mieux comprendre le comportement d'un précurseur lignocellulosique. Puis, l'étude des paramètres de l'étape d'activation, notamment la teneur en eau du gaz vecteur, a permis de couvrir un domaine de propriétés texturales étendu. Enfin, l'utilisation de procédés d'oxydation cyclique à l'air et à l'eau de javel a permis de contrôler, après élaboration, les propriétés microporeuses de charbons actifs aux textures différentes. En outre, l'utilisation de techniques d'analyses physico-chimiques a permis d'identifier et quantifier les groupements oxygénés formés lors des cycles d'oxydation.

Download or read book PREPARATION ET CARACTERISATION DE CHARBONS ACTIFS ISSUS DE TROIS PRECURSEURS LIGNOCELLULOSIQUES written by LUCIE.. LARGITTE and published by . This book was released on 2000 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: DES CHARBONS ACTIFS ONT ETE PREPARES A PARTIR DE PRECURSEURS LIGNOCELLULOSIQUES TROPICAUX : - GRAINES DE GOYAVE (PSIDIUM GUAJAVA L.) - COQUES DE DENDE (ACROCOMIA KARUKERANA) - ET ECORCES D'AMANDE (TERMINALIA CATAPPA L.) LE PROCESSUS DE FABRICATION COMPORTE DEUX ETAPES. LA PREMIERE EST UNE ETAPE DE CARBONISATION. ELLE S'EST REALISEE A 800\C SOUS ATMOSPHERE D'AZOTE. ELLE A PERMIS D'OBTENIR UN CHARBON PLUS OU MOINS ORGANISE EN FONCTION DU TYPE DU PRECURSEUR DE DEPART, RICHE EN CARBONE ET DE POROSITE ETROITE. LA SECONDE EST L'ETAPE D'ACTIVATION. ELLE CONSISTE A FAIRE PASSER UN FLUX DE GAZ OXYDANT SUR LE CHARBON AFIN DE SUPPRIMER DU CARBONE ET DE PERMETTRE LA CREATION D'UNE POROSITE NOUVELLE OU DE REVELER LA POROSITE EXISTANTE. L'ACTIVATION A ETE MENEE A 800\C EN UTILISANT LE DIOXYDE DE CARBONE ET LA VAPEUR D'EAU. LA TEXTURE DES CHARBONS ACTIFS A ETE ETUDIEE AU MICROSCOPE ELECTRONIQUE A BALAYAGE, PAR ADSORPTIOMETRIE ET PAR DIFFUSION X AUX PETITS ANGLES. QUE L'ACTIVATION SOIT MENEE SOUS DIOXYDE DE CARBONE OU SOUS VAPEUR D'EAU, LES TROIS TYPES DE CHARBONS ACTIFS RESTENT ESSENTIELLEMENT MICRO POREUX. CEPENDANT, LE DEVELOPPEMENT DE LEUR MESO POROSITE VARIE EN FONCTION DU TYPE DE CHARBON ACTIF OU DU GAZ OXYDANT UTILISE. SOUS VAPEUR D'EAU, LES TROIS CHARBONS ACTIFS REUSSISSENT UN DEVELOPPEMENT OPTIMAL DE LEUR MESO POROSITE (DES TROIS CHARBONS ACTIFS, LE CHARBON D'ECORCES D'AMANDE EST CELUI QUI DEVELOPPE LA POROSITE MOINDRE). SOUS DIOXYDE DE CARBONE, SEUL LE CHARBON ACTIF DE GRAINES DE GOYAVE PRESENTE UN DEVELOPPEMENT OPTIMAL DE SA MESO POROSITE, LA MESO POROSITE DU CHARBON ACTIF DE COQUES DE DENDE EST MOYENNE, CELLE DU CHARBON ACTIF D'ECORCES D'AMANDE EST QUASI INEXISTANTE. CES CHARBONS ACTIFS DE LABORATOIRE ONT DES PROPRIETES D'ADSORPTION TRES VOISINES DE CELLES DES CHARBONS ACTIFS COMMERCIAUX. OR, LES CHARBONS ACTIFS SONT UTILISES DANS LE CADRE DE L'EPURATION DES ATMOSPHERES POLLUEES ET DES EAUX USEES. LA PROCHAINE ETAPE DE CE TRAVAIL CONSISTERA A UTILISER CES CHARBONS ACTIFS DE MANIERE CONCRETE, A LES TESTER DANS DES ATMOSPHERES OU DES EAUX POLLUEES.

Download or read book Pr paration caract risation et application des mat riaux carbon s written by Meriem Belhachemi-Abdoun and published by Univ Europeenne. This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Elaboration de charbons actifs magn tisables written by Christophe Porquet and published by . This book was released on 1999 with total page 209 pages. Available in PDF, EPUB and Kindle. Book excerpt: Les charbons actifs interviennent dans de nombreux procédés industriels de traitement des eaux résiduaires. Trois grands types de conditionnement sont répertoriés : les charbons actifs en poudres, les charbons actifs en grains et le tissu de charbon activé. La mise au point de charbon actif à propriétés ferromagnétiques permet d'envisager la récupération des adsorbants après utilisation par l'action de champ électromagnétique externe imposé. L'élaboration de tels charbons actifs résulte d'une activation thermochimique appropriée obtenue par pyrolyse ménagée de matière végétale, avec intercalation d'oxydes métalliques qui rendent les charbons actifs aimantables. L'étude des paramètres thermiques et l'utilisation de plans d'expériences factoriels ont permis de déterminer les conditions optimales de température, de vitesse de chauffe ainsi que les temps de séjour de traitement thermique. Des études complémentaires ont mis en évidence l'influence sur la surface BET des charbons actifs élaborés en lit fixe de la longueur de passage des gaz de pyrolyse à travers le lit de matière première en cours de traitement. Des mesures de capacités d'adsorption sur différents types de molécules (diéthylèneglycol-monohéxyléther, hexanol, acide butyrique...) donnent des résultats probants et montrent des affinités entre les charbons actifs testés et les molécules hydrophobes. Ceci en conformité avec la littérature. L'observation d'échantillons au MES, ainsi que des analyses aux rayons ont permis d'établir la présence au sein de la structure carbonée d'oxydes de fer qui se sont révélés être de la magnétite et de l'hématite. La présence de ces cristaux permet de rendre ces charbons actifs ferromagnétiques, comme on a pu le vérifier par hystérésimétrie. Les capacités à l'aimantation des produits obtenus ont été vérifiées à l'aide d'une balance magnétique mise au point au laboratoire. Les propriétés magnétiques des charbons actifs ainsi élaborés sous forme de poudre se sont révélées être indépendantes de la granulométrie dans une gamme variant de 80 m à 2 mm. Enfin, des essais de récupération magnétique en phase liquide ont permis d'établir des taux de récupération de 98 % pour des charbons actifs de granulométrie de 150 m.

Download or read book De l laboration de charbons actifs support s dans une matrice de graphite naturel expans aux applications de s paration de gaz written by Damien Menard and published by . This book was released on 2001 with total page 249 pages. Available in PDF, EPUB and Kindle. Book excerpt: L'objectif de ces travaux est de développer des matériaux améliorant les performances des procédés d'adsorption séparative par une meilleure maîtrise thermique du procédé. L'élaboration des charbons actifs activés dans un support poreux de graphite naturel expansé consolidé permet la réalisation de monolithes macroscopiques aux formes variées. Nos travaux ont permis une meilleure connaissance des phénomènes mis en jeu lors du procédé de fabrication, conduisant à l'élaboration de matériaux à composition densité et volumes ciblés. La caractérisation des différentes propriétés de transfert des composites confirme leur potentiel, notamment du point de vue du transfert thermique, avec des conductivités et des conductances de contact qui peuvent atteindre respectivement 30 Wm-1K-1[exponentiels moins un].

Download or read book M thodes de contr le d valuation des charbons actifs written by Conseil européen des Fédérations de l'industrie chimique and published by . This book was released on 1989 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ancient Wine written by Patrick E. McGovern and published by Princeton University Press. This book was released on 2019-10 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stone age wine -- The Noah hypothesis -- The archaeological and chemical hunt for the earliest wine -- Neolithic wine! -- Wine of the earliest pharaohs -- Wine of Egypt's golden age -- Wine of the world's first cities -- Wine and the great empires of the ancient Near East -- The Holy Land's bounty -- Lands of Dionysos : Greece and western Anatolia -- A beverage for King Midas and at the limits of the civilized world -- Molecular archaeology, wine, and a view to the future.

Download or read book ICREEC 2019 written by Ahmed Belasri and published by Springer Nature. This book was released on 2020-06-10 with total page 659 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Spectroscopic Methods in Mineralogy and Geology written by Frank C. Hawthorne and published by Walter de Gruyter GmbH & Co KG. This book was released on 2018-12-17 with total page 716 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume 18 of Reviews in Mineralogy provides a general introduction to the use of spectroscopic techniques in Earth Sciences. It gives an Introduction To Spectroscopic Methods and covers Symmetry, Group Theory And Quantum Mechanics; Spectrum-Fitting Methods; Infrared And Raman Spectroscopy; Inelastic Neutron Scattering; Vibrational Spectroscopy Of Hydrous Components; Optical Spectroscopy; Mossbauer Spectroscopy; MAS NMR Spectroscopy Of Minerals And Glasses; NMR Spectroscopy And Dynamic Processes In Mineralogy And Geochemistry; X-Ray Absorption Spectroscopy: Applications In Mineralogy ind Geochemistry; Electron Paramagnetic Resonance; Auger Electron And X-Ray Photelectron Spectroscopies and Luminescence, X-Ray Emission and New Spectroscopies. The authors of this volume presented a short course, entitled "Spectroscopic Methods in Mineralogy and Geology", May 13-15, 1988, in Hunt Valley, Maryland.

Download or read book Zola and the Bourgeoisie written by Brian Nelson and published by Springer. This book was released on 1983-06-09 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Equilibria and Dynamics of Gas Adsorption on Heterogeneous Solid Surfaces written by W.A. Steele and published by Elsevier. This book was released on 1996-12-17 with total page 909 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fact that the surfaces of real solids are geometrically distorted and chemically non-uniform has long been realized by the scientists investigating various phenomena occurring on solid surfaces. Even in the case when diffraction experiments show a well-organized bulk solid structure, the surface atoms or molecules will usually exhibit a much smaller degree of surface organization. In addition to the results obtained from electron diffraction, this can be seen in the impressive images obtained from STM and AFM microscopies. This geometric and chemical disorder is the source of the energetic heterogeneity for molecules adsorbing on real solid surfaces. Hundreds of papers have been published showing that this heterogeneity is a major factor in determining the behaviour of real adsorption systems.Studies of adsorption on energetically heterogeneous surfaces have proceeded along three somewhat separate paths, with only minor coupling of ideas. One was the study of adsorption equilibria on heterogeneous solid surfaces. The second path was the study of time evolution of adsorption processes such as surface diffusion or adsorption-desorption kinetics on heterogeneous surfaces, and the third was the study of adsorption in porous solids, or more generally, adsorption in systems with limited dimensions. The present monograph is a first attempt to provide a synthesis of the ways that surface geometric and energetic heterogeneities affect both the equilibria and the time evolution of adsorption on real solids. The book contains 17 chapters written by a team of internationally recognized specialists, some of whom have already published books on adsorption.

Download or read book Wine Analysis and Production written by Zoecklein and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 639 pages. Available in PDF, EPUB and Kindle. Book excerpt: Winemaking as a form of food preseIVation is as old as civilization. Wine has been an integral component of people's daily diet since its discovery and has also played an important role in the development of society, reli gion, and culture. We are currently drinking the best wines ever produced. We are able to do this because of our increased understanding of grape growing, biochemistry and microbiology of fermentation, our use of ad vanced technology in production, and our ability to measure the various major and minor components that comprise this fascinating beverage. Historically, winemakers succeeded with slow but gradual improvements brought about by combinations of folklore, obseIVation, and luck. How ever, they also had monumental failures resulting in the necessity to dis pose of wine or convert it into distilled spirits or vinegar. It was assumed that even the most marginally drinkable wines could be marketed. This is not the case for modem producers. The costs of grapes, the technology used in production, oak barrels, corks, bottling equipment, etc. , have in creased dramatically and continue to rise. Consumers are now accustomed to supplies of inexpensive and high-quality varietals and blends; they con tinue to demand better. Modem winemakers now rely on basic science and xvi Preface xvii the systematic application of their art to produce products pleasing to the increasingly knowledgeable consumer base that enjoys wine as part of its civilized society.

Download or read book Bananas and Food Security written by Claudine Picq and published by Bioversity International. This book was released on 1999 with total page 806 pages. Available in PDF, EPUB and Kindle. Book excerpt: Importance de la banane sur les plans economique et alimentaire; Diversite et dynamique des filieres; Organisation des marches et commercialisation; Systemes de productions/production systems.

Download or read book Guidelines for Soil Description written by Food and Agriculture Organization of the United Nations and published by Food & Agriculture Org.. This book was released on 2006 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soils are affected by human activities, such as industrial, municipal and agriculture, that often result in soil degradation and loss. In order to prevent soil degradation and to rehabilitate the potentials of degraded soils, reliable soil data are the most important prerequisites for the design of appropriate land-use systems and soil management practices as well as for a better understanding of the environment. The availability of reliable information on soil morphology and other characteristics obtained through examination and description of the soil in the field is essential, and the use of a common language is of prime importance. These guidelines, based on the latest internationally accepted systems and classifications, provide a complete procedure for soil description and for collecting field data. To help beginners, some explanatory notes are included as well as keys based on simple test and observations.--Publisher's description.

Download or read book The Yeasts written by Cletus Kurtzman and published by Elsevier. This book was released on 2011-05-09 with total page 2362 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Yeasts: A Taxonomic Study is a three-volume book that covers the taxonomic aspect of yeasts. The main goal of this book is to provide important information about the identification of yeasts. It also discusses the growth tests that can be used to identify different species of yeasts, and it examines how the more important species of yeasts provide information for the selection of species needed for biotechnology. • Volume 1 discusses the identification, classification and importance of yeasts in the field of biotechnology. • Volume 2 focuses on the identification and classification of ascomycetous yeasts. • Volume 3 deals with the identification and classification of basidiomycetous yeasts, along with the genus Prototheca. - High-quality photomicrographs and line drawings - Detailed phylogenetic trees - Up-to-date, clearly presented yeast taxonomy and systematic, easy-to-use reference sequence accession numbers to allow for correct identification

Download or read book French English Medical Dictionary written by Alfred Gordon and published by . This book was released on 1921 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book UNESCO General History of Africa Vol I Abridged Edition written by Jacqueline Ki-Zerbo and published by Univ of California Press. This book was released on 1990 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This volume covers the period from the end of the Neolithic era to the beginning of the seventh century of our era. This lengthy period includes the civilization of Ancient Egypt, the history of Nubia, Ethiopia, North Africa and the Sahara, as well as of the other regions of the continent and its islands."--Publisher's description