Download or read book ETUDE COMPARATIVE DES PROPRIETES DE TRANSPORT ET DES PROPRIETES MAGNETIQUES D ALLIAGES A BASE DE PALLADIUM ET PALLADIUM HYDROGENE written by Blaise Souffache and published by . This book was released on 1986 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: ON PRESENTE UNE METHODE DOUCE D'HYDROGENATION DE PD ET DE SES ALLIAGES PERMETTANT D'OBTENIR DES CONCENTRATIONS X POUR DES COMPOSES PDH::(X) VOISINES DE 1. LES VARIATIONS DE RESISTIVITE RESIDUELLE AU COURS DE L'HYDROGENATION SONT EXPLIQUEES PAR UN MODELE DE MILIEU EFFECTIF POUR X0,65 ET PAR UN MODELE DE DIFFUSION LOCALE POUR X0,65. L'ETUDE DE LA RESISTIVITE DE PHONONS DE PDH FAIT APPARAITRE UNE BRANCHE DE PHONONS OPTIQUES TRES BIEN DECOUPLEE DE LA BRANCHE ACOUSTIQUE RESPONSABLE DE LA SUPRACONDUCTIVITE DE CE COMPOSE. L'ETUDE DES INTERACTIONS MAGNETIQUES DANS LES ALLIAGES AVEC UNE IMPURETE FE, CO OU MN REVELE DEUX TYPES DE COUPLAGES ENTRE LES MOMENTS LOCALISES SUIVANT LA CONCENTRATION

Download or read book Some Transport Properties of Palladium hydrogen and Palladium deuterium Alloys microform written by Nan-Sang Ho and published by National Library of Canada. This book was released on 1969 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Palladium Hydrogen System written by F. A. Lewis and published by . This book was released on 1967 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Recovery of Platinum Palladium and Gold from Stillwater Complex Flotation Concentrate by a Roasting leaching Procedure written by and published by . This book was released on 1985 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Bureau of Mines devised a procedure for selectively extracting platinum-group metals (PGM) and gold from Stillwater Complex flotation concentrate. The Stillwater Complex is the only major U.S. PGM resource. Development of a suitable extraction technique will contribute to its exploitation. The concentrate was roasted at 1,050° C to convert host base-metal sulfides to oxides and the PGM from sulfide minerals to their elemental states. The roasted concentrate was preleached with dilute sulfuric acid to remove easily soluble gangue minerals. After pre-leaching, the concentrate was slurried with 6M HCI and leached at ambient temperature and pressure with a strong-oxidizing agent. Hydrogen peroxide, chlorine, sodium hypochlorite, nitric acid, and a persulfate salt were the oxidants investigated. The two-stage leaching scheme ex-tracted up to 97 pct of the platinum, 92 pct of the palladium, and 99 pct of the gold from the roasted concentrate. The base metals were not solubilized and reported to the residue. No attempt was made to devise a procedure to recover the copper and nickel because they comprise less than 5 pct of the value of the concentrate. Viable techniques for recovering the precious metals from the pregnant solution were sulfide precipitation, cementation with nickel, or adsorption on activated carbon.

Download or read book Some Transport Properties of Palladium hydrogen and Palladium deuterium Alloys written by Nan-Sang Ho and published by . This book was released on 1969 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Palladium Emissions in the Environment written by Fathi Zereini and published by Springer Science & Business Media. This book was released on 2006 with total page 680 pages. Available in PDF, EPUB and Kindle. Book excerpt: To date the investigations of metal emissions from automotive catalysts has focused mainly on platinum. Since 1993, however, platinum has been increasingly replaced by palladium as the predominant substance in pollution-control catalysts. Now the release of palladium in automotive catalysts is becoming just a critical problem as that of platinum. The editors present the latest research results related to all aspects of palladium emissions in the environment, as well as an assessment of their effects on the environment and health. The book focuses on the following topics: analytical methods; sources of palladium emissions; occurrence, chemical behaviour and fate in the environment; bioavailability and biomonitoring; and health-risk potential.

Download or read book Hydrogen Transport and Embrittlement for Palladium Coated Vanadium chromium titanium Alloys written by and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Hydrogen Transport in Palladium and Iron Palladium Thin Films and Nanocomposites written by Paul Fitzgerald Buckley and published by . This book was released on 2002 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Palladium Recovery Properties and Uses written by Edmund Merriman Wise and published by . This book was released on 1968 with total page 187 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Contribution l tude de l or du palladium et de leurs alliages par spectrographie X written by Chintamani MANDE and published by . This book was released on 1958 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Palladium written by Kenneth M. Brady and published by Nova Science Pub Incorporated. This book was released on 2011 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: Palladium is a chemical element with the chemical symbol Pd. Palladium is also a rare and lustrous silvery-white metal. The unique properties of palladium and other platinum group metals account for their widespread use. One in four goods manufactured today either contain platinum group metals or had platinum group metals play a key role during their manufacturing process. Palladium is found in many electronics including computers, mobile phones, multi-layer ceramic capacitors, component plating, low voltage electrical contacts, and SED/OLED/LCD televisions. Palladium is also used in dentistry, medicine, hydrogen purification, chemical applications, and groundwater treatment. Palladium plays a key role in the technology used for fuel cells, which combines hydrogen and oxygen to produce electricity, heat and water. This book presents topical research data from across the globe in the study of palladium and its production and applications.

Download or read book Int raction de l hydrog ne avec la microstructure des alliages de palladium written by Viviane Monteiro Azambuja and published by . This book was released on 2008 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dans cette thèse, l'interaction de l'hydrogène avec la structure cristalline d'alliages de palladium contenant du cérium et du zirconium a été étudié. Les alliages synthétisés dans un four à arc, dans les compositions Pd0.97Ce0.03; Pd0.97Zr0.03 et Pd0.97Zr0.015Ce0.015, ont été laminés à froid et un échantillon de chaque alliage a été soumis à une oxydation interne par traitement thermique sous différentes conditions. L'oxydation interne promeut la formation de précipités d'oxydes de cérium et zirconium dans les alliages. Ceux-ci ont été caractérisés par microscopie électronique à balayage et par transmission. Les alliages ont aussi été testés par perméation à l'hydrogène pour caractériser l'influence de la microstructure sur la diffusivité et solubilité de l'hydrogène ainsi que sur la formation d'hydrures dans ces alliages. Les alliages oxydés internement à 1073 K pendant 24 h présentent des valeurs de diffusivité d'hydrogène plus faibles (0,3 x 10-11m^2s^-1 pour l'alliage Pd0,97Zr0,03) et des valeurs de solubilité d'hydrogène plus grands (5672 molHm-3 pour l'alliage Pd0,97Zr0,015Ce0,015) par rapport aux autres échantillons traités dans d'autres conditions, à cause de la formation de précipites nanométriques de CeO2 et ZrO2 provenant de l'oxydation interne. Ces précipités sont cohérents avec la matrice de palladium, distordent beaucoup la matrice et, pour cette raison, interagissent effectivement avec l'hydrogène. Avec l'augmentation de la taille des précipités, l'interaction avec l'hydrogène diminue, les valeurs de diffusivité augmentent et les valeurs de solubilité de l'hydrogène diminuent dans les alliages. En relation à la formation de phase hydrure, les échantillons sans traitement d'oxydation interne présentent une plus grande difficulté à former des hydrures par rapport à ceux oxydés internement, à cause de la présence d'atomes en solution solide et de grandes quantités de dislocations et lacunes dans la matrice de palladium, qui ne permettent pas à la matrice de former une phase hydrure.

Download or read book Absorption and Diffusion of Hydrogen by Alloys of Palladium written by Dennis David Artman and published by . This book was released on 1975 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Transport Properties of Palladium gold Alloys written by Nguyen Hy Hau and published by . This book was released on 1966 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Caract risation thermodynamique microstructurale et cin tique d alliages de palladium au contact de l hydrog ne written by Joseph Rostand Ngameni Jiembou and published by . This book was released on 2010 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: Palladium-silver alloys are used in the industry for the purification of hydrogen. State-of-the-art materials still require optimization (i) to increase permeation flows ; (ii) to maintain performances on the long-term ; (iii) to reduce investment costs (development of thin membranes). To achieve these goals, it is necessary to measure in situ surface (H2 dissociative chemisorption) and bulk (diffusion transport of atomic H) kinetic contributions. The kinetics of chemical (gas-phase) and electrochemical (electrolyte) hydrogen insertion have been compared. Electrochemical and chemical impedance diagrams have been obtained from “potential step” and from “pressure step” experiments. Rate constants of individual steps have been measured. Then, the insertion of gaseous hydrogen into a metallic membrane of known surface state (texture and roughness factor) and known volume microstructure (grain size distribution) has been investigated. Values of surface resistance and hydrogen diffusion coefficient have been measured with temperature. By measuring the impedance of membranes of different thicknesses, it has been shown that the surface step is rate-determining. Then, the surface roughness of a membrane has been increased by electrochemical deposition of palladium black. A membrane showing a reduced surface resistance has been prepared and a diffusion impedance diagram has been obtained for the first time for a gas phase experiment.

Download or read book ETUDE DE LA SOLUBILITE ET DE LA DIFFUSION DE L HYDROGENE DANS DES ALLIAGES PALLADIUM SILICIUM AMORPHES written by Abdelhalim Magnouche and published by . This book was released on 1986 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: MESURES THERMOGRAVIMETRIQUES SOUS DES PRESSIONS DE GAZ INFERIEURES A 2,5MPA ENTRE 200 ET 400**(O)C POUR LE PALLADIUM CRISTALLIN ET ENTRE 20 ET 200**(O)C POUR LES ALLIAGES AMORPHES. MESURES DE RESISTANCE ELECTRIQUE POUR DES PRESSIONS DE GAZ ALLANT JUSQU'A 12,5MPA. OBSERVATION DE LA DEVIATION PAR RAPPORT A LA LOI DE SIEVERTS. INFLUENCES DE LA TEMPERATURE ET DE LA CONCENTRATION SUR L'ENTHALPIE DE DISSOLUTION. DETERMINATION DU COEFFICIENT DE DIFFUSION ET DE L'ENERGIE D'ACTIVATION. TENTATIVES D'INTERPRETATION PAR LE MODELE DE LACHER DES DEVIATIONS PAR RAPPORT A LA LOI DE SIEVERTS. APPROCHE DE LA STRUCTURE DU SYSTEME PD-SI, EN CONSIDERANT DEUX TYPES DE SITES ACCEPTEURS DE L'HYDROGENE DISTRIBUES EN NOMBRE ET EN ENERGIE

Download or read book ETUDE DES PROCESSUS IMPLIQUANT L HYDROGENE SUR DES FILMS MINCES DE PALLADIUM EN MILIEU ACIDE written by Pierre-Philippe Grand and published by National Library of Canada = Bibliothèque nationale du Canada. This book was released on 2001 with total page 277 pages. Available in PDF, EPUB and Kindle. Book excerpt: LE TRAVAIL REALISE AU COURS DE CETTE THESE PORTE SUR L'ETUDE DU SYSTEME HYDROGENE/PALLADIUM DANS LA GAMME DE SURTENSIONS PERMETTANT LA FORMATION DES PHASES ET -PDH. A L'AIDE DE NOMBREUSES TECHNIQUES ELECTROCHIMIQUE, LES PROCESSUS AYANT LIEU A LA SURFACE ET DANS LES FILMS DE PALLADIUM ONT ETE ETUDIES. UNE ATTENTION PARTICULIERE A ETE PORTEE AU ROLE DE LA CONTRAINTE DUE A L'INSERTION DE L'HYDROGENE DANS LE PD ET DU PIEGEAGE DE L'HYDROGENE DANS LES FILMS. LES TECHNIQUES PIEZO-ELECTRIQUES ONT PERMIS DE METTRE EN EVIDENCE UN EFFET DE CONTRAINTE TRANSITOIRE DU A L'INSERTION DE L'HYDROGENE. UN DYSFONCTIONNEMENT DE LA MICROBALANCE LIE A UN EFFET DE CONTRAINTE GENEREE PAR L'INSERTION DE L'HYDROGENE DANS LE RESEAU DU PD A EGALEMENT ETE OBSERVE DANS LA PHASE -PDH. LES RESULTATS D'IMPEDANCE ET DE VOLTAMPEROMETRIE POUR LES FAIBLES EPAISSEURS DE FILMS ONT MONTRE UN COMPORTEMENT DIFFERENT DE CELUI DES FILMS DE PLUS FORTE EPAISSEUR. CE COMPORTEMENT POURRAIT ETRE ATTRIBUE A UN PIEGEAGE DE L'HYDROGENE DANS UNE SOUS-COUCHE SOUS LA SURFACE DU PALLADIUM EN CONTACT AVEC L'ELECTROLYTE. UN MODELE, EN BON ACCORD AVEC LES RESULTATS EXPERIMENTAUX, INCLUANT UNE CINETIQUE DE PIEGEAGE/DEPIEGEAGE REVERSIBLE DE L'HYDROGENE DANS LE FILM ET D'UNE DESORPTION DIRECTE DE L'HYDROGENE A ETE PROPOSE.