Search results for "Diss"
showing 10 items of 2500 documents
Anhydrous Amorphous Calcium Oxalate Nanoparticles from Ionic Liquids: Stable Crystallization Intermediates in the Formation of Whewellite
2015
The mechanisms by which amorphous intermediates transform into crystalline materials are not well understood. To test the viability and the limits of the classical crystallization, new model systems for crystallization are needed. With a view to elucidating the formation of an amorphous precursor and its subsequent crystallization, the crystallization of calcium oxalate, a biomineral widely occurring in plants, is investigated. Amorphous calcium oxalate (ACO) precipitated from an aqueous solution is described as a hydrated metastable phase, as often observed during low-temperature inorganic synthesis and biomineralization. In the presence of water, ACO rapidly transforms into hydrated whewe…
Complexes of molybdenum(VI) with organic diacid ligands: The molybdenum(VI)-malonic acid system
1983
Malonic acid (C3O4H4) and MoVI form in aqueous solution two dinuclear dioxo-complexes of which the stability is a function of the pH of the medium. Both complexes have a 1∶1 metal-ligand stoichiometric ratio, and the interconversion may involve a structural rearrangement. Conditional dissociation constants have been determined spectrophotometrically. Saline cryoscopy supports the spectrophotometric results. Salts of [Co(en)3]3+ have been isolated. The ligand behaviour of malonic acid differs partially from that observed for α-polyhydroxy ligands.
Cation and anion electrochemically assisted solid-state transformations of malachite green
2020
[EN] The possibility of the electrochemical promotion of different solid-to-solid transformations including the performance of successive cation and anion insertion processes has been tested using malachite green, a triphenylmethane dye, in contact with aqueous NaCl electrolyte. Electrochemical data using the voltammetry of microparticles methodology reveal significant differences with the solution phase electrochemistry of the dye. Voltammetric data, combined with atomic force microscopy, focusing ion beam-field emission scanning electron microscopy, and high-resolution field emission scanning electron microscopy permit characterization of the oxidative dissolution, oxidation with anion in…
Effect of Anions and Oxygen on the Kinetics of the Anodic Dissolution of Nickel
2006
An electrochemical impedance spectroscopy study on electrochemical dissolution and active/passive transition of polycrystalline nickel in acid media has been performed in sulfate and nitrate aqueous solutions. Oxygen favors the nickel electrodissolution in a nitrate aqueous acid medium, but the dissolution decreases in the sulfate medium due to nickel passivation. The anion and oxygen effect is analyzed from a model where Ni(I) species are stabilized on the Ni metal surface and all anions present in the solution compete in the neutralization of Ni(I) and Ni(II) and in the solubilization of Ni(II).
Fractional dissolution of “solid” unsubstituted cellulose
2000
Activated cellulose (Solucell, DP w = 1400) was extracted stepwise at room temperatures by means of mixed solvents consisting of N,N-dimethylacetamide (DMAc) and LiCl, starting with a salt concentration of 1 wt.-% and increasing it in increments of 1 wt.-% up to 7 wt.-%. Upon the regeneration of the thus obtained cellulose fractions by pouring the solutions dropwise into a large surplus of water, part of the mixed solvent is occluded in the polymer. For that reason the cellulose samples were purified by redissolving them in Ni-tren and by a second precipitation. This process, however, leads to pronounced polymer degradation. For that reason we have used a spinning nozzle to press the extrac…
Sentence arbitrale. Secret du délibéré, Opinion dissidente, Communication aux parties, Conséquence, Le contrôle de la décision d'incompétence des arb…
1995
International audience; (Paris, 7 juill. 1994, Rev. arb. 1995. 106, note S. Jarvin ; Uzinexportimport Romanian Co c/ Attock Cement C°)
La validité de l'opinion dissidente en droit français interne et international de l'arbitrage
2009
International audience; (Paris, 1re ch. C, 9 oct. 2008, n° 07/6619, SAS Merial c/ Sté Klocke Verpackungs - Service Gmbh, inédit)
Design and implementation of an augmented reality application for rock art visualization in Cova dels Cavalls (Spain)
2019
[EN] Prehistoric rock art paintings, specifically rock-shelters exposed to environmental and anthropogenic factors, are usually faint and severely damaged, being them difficult to identify and understand by visitors. Augmented Reality (AR) supplements reality with virtual information superimposed onto the real world. This sensor-based technology in smartphones/tablets can improve the paintings experience displaying the 2D digital tracings overlapped onto the real scene (rock with faint paintings). This paper presents an AR application (app) developed in Cova dels Cavalls that shows a recreation of a possible original composition full of motifs with descriptive information to improve current…
Modeling And Measurements Of The Arc Plasma In A Mixture Of Gases
2006
Radial distributions of Ar mass fractions and temperatures in plasmas produced in a wall-stabilized arc have been calculated. Modeling have been performed for many different mixtures of Ar+N2 and three different arc currents. The obtained results show that the radial distributions of Ar mass fractions strongly depend on the chemical composition of the plasma. In plasmas containing large amount of Ar the distributions have local minima at the arc axis (in high temperature plasma regions), whereas in plasmas consisting mainly of nitrogen the distributions reveal maxima on the discharge axis. Those features seem to be connected with the dissociation of the nitrogen.
Chemisorption of hydrogen on a V5+ cluster
1996
Abstract The binding between V 5 + and hydrogen is studied by collision induced dissociation of the cluster-adsorbate V 5 + H 2 . Vanadium clusters are produced by laser vaporization and injected into an electromagnetic ion trap. After mass separation of V 5 + , the pulsed addition of hydrogen yields V 5 + H 2 . The desorption of hydrogen is studied by acceleration of V 5 + H 2 with variable rf voltages and collisions with argon atoms. From the threshold voltage necessary for dissociation a binding energy of H 2 on V 5 + of 2.4 ± 0.3 eV is estimated. This value is consistent with a dissociative chemisorption of hydrogen.