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Showing 1 to 20 of 56 for “"Surface oxidation"”.
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Modeling Manganese Sorption and Surface Oxidation During Filtration
… to experimental data and used to evaluate the oxidation rate constant, which was the only unknown parameter. An inverse relationship between the fitted reaction rate constant and chlorine concentration was observed, showing that the oxidation reaction does not depend on chlorine concentration …
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Surface Oxidation and Dissolution of Metal Nanocatalysts in Acid Medium
… pure catalyst. However, the acid medium and the oxidation of the surface reduce the activity and durability of the alloy catalyst through changes in its local composition and structure. Molecular simulation techniques are applied to characterize the thermodynamics and dynamic evolution of the …
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Effects of Surface Oxidation on Vacancy Defects in Beta Nickel-Aluminum Alloys
… has been used to make observations of the oxidation process in (beta)-NiAl alloys annealed under controlled conditions of temperature and oxygen partial pressure. Binary Ni-Al alloys, with nominally 47.5, 50.4 and 52.5 at .% Al, were examined. The Auger spectroscopy analysis showed that the …
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Anodic Behavior of Gold: I. Surface Oxidation. Ii. Monolayer Adsorption of Palmitic Acid
Made available in DSpace on 2014-12-05T19:37:40Z (GMT). No. of bitstreams: 1 6101600.pdf: 3514553 bytes, checksum: 679ce013fcd4a77df27153813cf7be7b (MD5) Previous issue date: 1961
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The use of simple analytical techniques to assess surface oxidation of sulphide ores
Surface oxidation is known to have a negative impact on the flotation performance of sulphide minerals. This is because severe oxidation makes it more difficult to process low-grade sulphide minerals, which reduces the recovery of valuable minerals during flotation. It may be possible to …
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The role of surface oxidation in the break-up of laminar liquid metal jets
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1996.
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Computational Investigations at the Gas-Surface Interface: Organic Surface Oxidation and Hydrolysis of Chemical Warfare Agents and Simulants
Motivated by recent experiments in gas-surface chemistry, we report our results from computational investigations of heterogeneous systems relevant to atmospheric chemistry and protection against chemical weapons. To elucidate findings of ultra-high vacuum experiments that probe the oxidation of …
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Study on the surface chemistry behavior of pyrochlore during froth flotation
… typically accomplished by froth flotation. The surface chemistry of pyrochlore is similar to many of its associated non-value minerals. Therefore, understanding the surface chemical properties of the pyrochlore for selective pyrochlore flotation will potentially aid in the design of flotation …
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Collectorless flotation of chalcopyrite and sphalerite ores
… sulfide, presumably to remove the hydrophilic surface oxidation products. On the other hand, the flotation of sphalerite ores was found to require both sodium sulfide treatment and copper-activation. The ratio of these two reagents was most critical, the optimum Cu²⁺/S²⁻ atomic ratio being …
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Effect of Alkali on the Efficiency and Reliability of Cu(In,Ga)Se2 Solar Cells
… thin films showed drastic micro-structural, surface morphology, electrical and optical properties deterioration leading to the degradation of solar cell performance. In the case of bare CIGS thin films, we observed surface oxidation and degraded electronic properties, also leading to …
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Synthesis of Silicone Magnetic Fluids for Use in Eye Surgery
… are thought to coordinate onto the particle surface, while the PDMS endblocks protrude into the reaction medium to provide steric stability. The particle size can be controlled by adjusting the cobalt to copolymer ratio. Ordered self-assemblies of these cobalt nanoparticles are observed when …
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Carbon nanotube supported electrocatalysts for polymer electrolyte membrane fuel cells
… A sonochemical treatment method was applied for surface oxidation of multiwalled carbon nanotubes to achieve highly dispersed nanoparticles on them. Several surface functional groups were generated on the nanotubes, which contribute to the binding of nanoparticles"--Abstract, page iii.
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Second-harmonic generation as a probe of chemically modified Si(111) surfaces and the initial oxidation of hydrogen terminated Si(111)
… generation (SHG) is used to probe Si(111) surfaces with covalently attached monolayers. The surfaces are prepared using wet chemical modification to form -H, -C 10 H 21 (decyl) and -O-C 10 H 21 (decyloxy) monolayers. The SHG efficiency for these surfaces as well as a Si(111) surface with a …
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The role of nitrogen on the flotation performance of a complex sulphide ore
… of pH, temperature, dissolved oxygen (DO) and oxidation reduction potential (ORP, measured with a Pt - Ag/AgCI electrode) were recorded for each flotation test so as to monitor the changes in the pulp chemical environment, as a response to changes in milling media, reagent addition and gas …
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Heterogeneous Metallurgical Patterning of Semiconducting Oxide Nanostructures
By directly heating a surface-dezincified polycrystalline brass (Cu70Zn30 alloy) in ambient conditions, semiconductor nanostructure networks composed of CuO nanofilm and ZnO nanowires have been successfully fabricated. The dezincification induced by metallographic etching on Cu70Zn30 …
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Evaluation of Novel and Low-Cost Materials for Bipolar Plates in PEM Fuel Cells
… 200 hours, while the other sample experienced surface oxidation and eventually failed. With improvements in part conductivity coming from conductive polymers, this manufacturing technique holds the promise of producing monopolar and bipolar plates that could eventually be scaled up for use in …
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Crystallization kinetics of phase change materials for novel data storage concepts
… focus to the effect of the generally oxidized surface of the measured samples. It will be shown that for some materials the surface oxidation leads to an earlier crystallization of a layer close to the material's surface. Afterwards, the influence of capping layers preventing the surface …
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Effect of controlled oxidation processes on the emission and excitation of porous silicon
… radiative recombination and novel radiative surface state recombination. In small crystallites the number of surface atoms is a sizeable fraction of the total and therefore surface conditions (both type and quality) are expected to play an important role. We have performed time-resolved …
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Radiant Auto-Ignition of Wood
… and normal video cameras were used to view the surface of the wood. Surface temperature (by thermocouple and IR) and mass loss were continuously recorded. The wood grain orientation was aligned either perpendicular or parallel to the incident heat flux. The time for flaming ignition is measured …
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