Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 575 for “"Activation Energy"”.
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Activation energy of Douglas fir char gasification by carbon dioxide
The activation energy of Douglas fir wood char gasified in carbon dioxide was determined. Activation energies were found for chars that had been pyrolyzed in nitrogen at 600, 750, and 900°C. A thermogravimetric analyzer provided the weight versus temperature data used to obtain the activation …
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Controlling Activation Energy to Wafers and Walls in Plasma Processing Reactors for Microelectronics Fabrication
Wafer-to-wafer reproducibility during plasma etching presents another challenge. The use of low-pressure, high-density discharges results in increasing buildup of etch products in the plasma reactor resulting in increased interactions of etch products with wafer and non-wafer surfaces, alike. …
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The Intrinsic Activation Energy as a Guide to Mechanisms of Reactions on Solid Surface
Through the Polanyi Relationship, the intrinsic activation energies calculated from gas phase reactions have been shown to provide practical information about the kinetics and mechanisms of surface reactions. Ab initio calculations showed that reaction pathways which involve C-C or C-O bond …
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A Direct Determination of the Activation Energy for the Reaction of Nitric Oxide With Ozone
A conventional Arrhenius fit to the data is
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The rate and activation energy of the first order dehydration of 2-butanol over a copper chromite catalyst
Call number: LD2668 .T4 1957 C35
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The rate and activation energy of the first order dehydration of 2-butanol over a copper chromite catalyst
Call number: LD2668 .T4 1957 C35
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Quantification Of Auto-Ignition In Diesel Engines
… quality of fuels by calculating global activation energy using Arrhenius plots with data measured for the ignition delay period (ID). Large variation in the activation energy of fuels has been observed even for fuels with closer CN values. More recently, the activation energy values …
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Creep of Copper at Intermediate and Low Temperatures
… for vacuum melted copper, and values for the activation energy term of this equation are determined. The method of determination and some of the difficulties involved in this determination are set forth. Additional values for the activation energy term as determined by Tietz and Dorn(23) are …
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Synthesis, Consolidation, and Mechanical Testing of Nanophase Metals
… exhibiting creep even at room temperature. The activation energies for both specimens are lower than activation energy for grain boundary diffusion in microcrystalline materials. A model is proposed to explain the higher creep rate. It assumes that the specimens produced from vapor condensed …
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Nonlinear Dynamic Combustion of Energetic Solids
The low gas-activation-energy WSB model is used to model the nonlinear unsteady combustion of energetic solids. Additional validation of the model has been obtained by considering the new oxidizer HNF. Comparison of predictions for HNF combustion with a wide range of experimental observations …
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Asymptotic studies of gravity-driven reacting coating flows and pultrusion processes
… flows down an inclined plane. When the reaction activation energy is large and heat release is significant, long wave theory and large activation energy asymptotics are applied jointly to derive a consistent set of governing equations, which describe wave formation on the free surface and …
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Chemiluminescence of Dimethyldioxetanone
… of 0.1 and 1.5% respectively. The composite activation energy for formation of singlet acetone is 3-4 kcal/mol greater than the activation energy for the thermal disappearance of dimethyldioxetanone. This result is interpreted in terms of two parallel competitive pathways for dioxetanone …
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Exploration of catalysis activation emergency as a function of gold nanoparticle surface morphology
… the 1:2 system, and lastly the 2:1 system. The activation energy for each ligand-ratio system was measured and found to be 22.17 kJ/mol for the 2:1 system, 14.7 kJ/mol for the 1:2 system, and 26.52 for the 1:1 system. The 2:1 and 1:2 systems followed the trend of lower activation energy values …
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The Chemical and Physical Properties of Tourmaline
… decomposition temperature was increased. The activation energy for the extraction of boric oxide as a function of the schorl decomposition temperature was found to be equal to 19.2 ± 0.4 kcal/mole. This increase in the rate of extraction of boric oxide was suggested to be associated with the …
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Development of an Analytical Method for Distinguishing Ammonium Bicarbonate from the Products of an Aqueous Ammonia Co2 Scrubber and the Characterization of Ammonium Bicarbonate
… ABC. Kinetic studies of ABC and LEABC gave their Activation Energy. At the 7.5% conversion rate, LEABC’s Activation Energy is 111.9 kJ/mole, which is greater than ABC’s Activation Energy 93.6 kJ/mole. The difference in Activation Energy explains the reason of different stability of ABC and LEABC.
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Diffusion and the thermal stability of amorphous copper-zirconium
… in crystalline Cu at the same temperatures. The activation energies for diffusion in the amorphous alloy are 0.72 to 1.55 ev/atom, much closer to the activation energy for self-diffusion in liquid Cu, 0.42 eV/atom, than that for the crystalline solid, 2.19 eV/atom. The mechanism for diffusion in …
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High temperature alkali corrosion kinetics of low expansion ceramics
… Si,N, and SiC is interfaced-controlled with an activation energy of 199 and 104 kJ/mol, respectively. The overall reaction in these materials involves a complex absorption-dissolution-oxidation process and the rate-controlling step appears to be the interfacial oxidation of Si,N, or SiC to SiO,. …
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Lifetime Testing of Wire-Grid Polarizers with Selected Over-Coatings
… a predetermined optical failure point. The activation energies were calculated by applying the Arrhenius model to the failure data. WGPs with no over-coating were found to have an activation energy ≥ 1.5329 eV, with silicon dioxide an activation energy ≥ 1.7197 eV, and with magnesium …
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Influence of lattice dynamics on the ionic conductivity and stability of solid-state lithium-ion conductors
Electrochemical energy storage devices are clean and efficient, but their current cost and performance limit their use in many transportation and stationary applications. Lithium-ion batteries are one of the leading candidates for these large applications, however their current use of liquid …
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