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Showing 1 to 20 of 55 for “"coprecipitation"”.
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Scavenging of particulate and dissolved lead compounds by coprecipitation with manganese oxyhydroxides
… to provide a quantitative understanding of the coprecipitation of Pb with Mn oxyhydroxides to demonstrate their capacity to remove Pb permanently from contaminated solutions. To accomplish this, a series of factorial experiments with varying initial Mn and Pb concentrations were run in the …
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Low-Temperature Densification of Lead Zirconate Titanate With Vanadium Pentoxide Additions
… Pb (Zr(,0.53)Ti(,0.47))O(,3), was prepared by coprecipitation from mixed oxides and butoxides. V(,2)O(,5) was incorporated as mill additions to the precalcined base PZT, as batch additions to the PZT during the coprecipitation process, and as mill additions to a commercially available PZT …
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Exploration of the mechanism of rhodium(III) co-precipitation with copper sulfide (at low rhodium concentrations) incorporating the cationic substitution reaction path
… into the mechanism and kinetics of Rh3+ coprecipitation with CuS upon aqueous thiosulphate addition to acidic base metal sulphate solutions, where Rh3+ concentration is two orders of magnitude lower than Cu2+, over 50 - 150 °C. The heterogeneous cationic substitution has been identified …
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The effect of Carbopol 934 rheological properties on the dissolution rate of sulphadamidine crystals.
… were produced; recrystallized, coated by coprecipitation from aqueous solution and coated by coprecipitation from organic solvent. Their physical characteristics were elucidated using particle size analysis (Coulter), chemical analysis, X-ray diffraction and optical and scanning electron …
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The supramolecular modification of trans-resveratrol and related antioxidant molecules
… and the native CDs (β- and γ-CD) by kneading and coprecipitation, as well as with methylated CDs by coprecipitation. The resulting inclusion complexes were characterised using powder X-ray diffraction (PXRD), ¹H nuclear magnetic resonance spectroscopy (¹H-NMR), thermogravimetric analysis (TGA), …
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Insights on the reactivity of environmental iron-containing nanoparticles.
… dissolution kinetics of ferrihydrite prepared by coprecipitation with or adsorption of up to 10 wt% arsenate were quantified. Arsenic adsorbed preferentially onto the most reactive surface sites substantially lowering the reductive dissolution rate. Coprecipitation led to structural defects, but …
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Encapsulamento de nanopartículas magnéticas em polímeros acrílicos e avaliação de hipertermia para potencial tratamento de câncer
… polymers. Magnetite (Fe3O4) was obtained through coprecipitation and encapsulated by inverse and direct miniemulsion polymerization, in poly(acrylic acid) and poly(methyl methacrylate), respectively. Besides, the folic acid bioconjugation with the surface of polymeric particles obtained by inverse …
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Magneto-Optical Study of Cobalt Ferrite Nanoparticles
… non-aqueous polar medium (diethylene glycol). A coprecipitation reaction with sodium hydroxide produces ferrite nanoparticles with average diameter of 6 nm. The nanoparticles can be stabilized by tetramethyl ammonium hydroxide in water, or, alternatively, the nanoparticles can be treated with a …
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Determination of radium-226 in drinking water by alpha spectroscopy
… The method involves concentrating radium by coprecipitation with barium sulfate; separating radium from barium and other alkaline earth metals by ion exchange; and electrodepositing radium onto stainless steel disc for radioactivity counting. The procedure requires the using a chemical yield …
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ΚΑΤΑΛΥΤΙΚΕΣ ΙΔΙΟΤΗΤΕΣ ΧΗΜΙΚΩΝ ΟΞΕΙΔΙΩΝ ΤΟΥ ΣΙΔΗΡΟΥ ΚΑΘΑΡΩΝ ΚΑΙ ΜΙΚΤΩΝ ΣΤΗ ΜΕΤΑΤΡΟΠΗ ΤΟΥ ΜΟΝΟΞΕΙΔΙΟΥ ΤΟΥ ΑΝΘΡΑΚΑ ΤΟΥ ΥΔΡΑΕΡΙΟΥ
… CR, CO OR NI AS A PROMOTER WERE PREPARED BY COPRECIPITATION, CALCINATION AND, WHEN NEEDED, REDUCTION X-RAY DIFFRACTION AND MOSSBAUER SPECTROSCOPY CONFIRMED THEFORMATION OF SPINEL FERRITES. THE ACTIVITIES OF THE PREPARED AND TWO INDUSTRIAL CATALYSTS WERE MEASURED IN AN ALL-GLASS FLOW-TYPE …
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Carbeto de molibdênio promovido por níquel como catalisador na reação de reforma seca do metano
… or not) were synthesized by the methods of coprecipitation (CP), wet impregnation and mechanical mixture in order to achieve the Ni/Mo molar ratio of 0.2. These oxides were carburized to synthetize the catalysts. The precursors and catalysts were characterized by X-ray diffraction (XRD), …
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Nanoparticle-chiral nematic liquid crystal composites
… of 10-20 nm. Direct nanoparticle synthesis via coprecipitation in microemulsions produced superior results, resulting in a pure YIG material with diameters on the order of 30-50 nm.
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Effects of phytic acid sorption on iron polymerization and at the ferrihydrite-water interface
… an additional P5 functional group became active. Coprecipitation experiments showed evidence of the formation of Fe(III)-phytate-like bulk precipitates when the initial phytic acid/Fe(III) molar ratio was high (0.45-0.5). At the low phytic acid/Fe(III) (<0.1), the formation of ferrihydrite was …
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Promoting material circularity in pulp and paper mills: organic-inorganic cellulosic composites for slow-release of nutrients
… of hydroxyapatite was performed via wet coprecipitation with two different calcium salts from the pulp and paper mill system: calcium hydroxide (Ca(OH)₂) and calcium carbonate (CaCO₃). The immobilisation of urea was conducted via in-situ wet coprecipitation using Ca(OH)₂, forming a …
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Analysis of a model to describe lead transport by the small intestine
… the tissue binding of lead by a process of coprecipitation, and may ultimately increase the entry of lead into the body. Chelated lead species exhibit different kinetic characteristics to that of the lead cation. The data suggests that chelation accelerates lead absorption, probably by the …
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Studies of tartaric acid modified nickel supported catalysts for enantioselective hydrogenation reactions
… ability, whereas materials prepared by the coprecipitation method does not. Also, this thesis researches the use of different types of ordered mesoporous silicas as supports of tartaric‐acid nickel in the aforementioned reaction. Even though the techniques of metal deposition explored did …
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A characterization and study of barium promoted silver catalysts for the partial oxidation of ethylene
… in the case of the catalysts prepared by coprecipitation. Octanol, used in the catalyst preparation step as a mulling agent, reacted with and altered the unconditioned AgO catalysts. However, the conditioning procedure removed the octanol reaction residue.</p> <p>The barium additives …
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Studies on the analytical chemistry of chromium in aqueous solutions
… of the various oxidation states of chromium by coprecipitation and preconcentration of trivalent chromium in aqueous solutions using iron(III) hydroxide as the coprecipitating agent has been studied. Recoveries of trivalent chromium are less than 100% because of formation of complexes of …
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Magnetophoretic focusing on submicron particles dispersed in a polymer-stabilized magnetic fluid
… solute to be separated. They were prepared by coprecipitation of iron (II) and (III) ions to form magnetite, which is coated by a comb copolymer that serves two purposes: to limit growth of magnetite to about 10 nm and to stabilize the particles against aggregation.
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Characterisation of Schwertmannite - Geochemical Interactions with Arsenate and Chromate and Significance in Sediments of Lignite Opencast Lakes
… and chromate) these anions were used for coprecipitation, adsorption- and stability-investigations with schwertmannite, to characterise its geochemical interactions. Synthesis (coprecipitation) experiments proved that schwertmannite, normally containing 12 to 14 wt.-% sulfate (both, …
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