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Showing 1 to 20 of 242 for “"Activation energies"”.
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Semiconduction and photoconduction activation energies of the retinals
Thesis (M.S.)--Michigan State University. Dept. of Biophysics, 1966
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Thermal vacancies in hcp helium-4
Activation energies of thermal vacancies have been determined in hcp 4He as a function of molar volume. A sensitive strain gauge was used to measure the temperature dependence of the pressure in twenty crystals between 18.17 and 20.9 cm3/mole. Absolute lattice parameters at low temperatures were …
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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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Silver Diffusion and Isotope Effect in Silver-Rubidium-Iodide
… with a low temperature sectioning apparatus. The activation energies for diffusion in alpha-RbAg(,4)I(,5) and beta-RbAg(,4)I(,5), respectively, are .11 (+OR-) .01 eV and .20 (+OR-) .04 eV. These values are the same, within experimental error, as the observed activation energies for conduction.
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A study of the self-diffusion of certain of the lower alkyl halides
… literature were insufficient for calculation of energies of activation. The diffusion coefficients were of the order of 2 x 10⁻⁵ cm².sec⁻ with activation energies of 2 kcal./mole; determined from plots of log D/T versus l/T. The temperatures at which coefficients were measured were 7.35, 19.35 …
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DFT insight into the oxygen reduction reaction (ORR) on the Pt₃Co(111) surface
… the transition states and to calculate the activation energies of the different elementary reaction steps. The calculated dissociation reaction activation energies for the Pt₃Co(111) surface are found to be lower than the dissociation activation energies calculated on the Pt(111) surface. …
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Computational Evaluation of Mechanistic Pathways of Action of Superoxide Dismutase
… by observing its effect on reducing the activation energies. Activation energies were computed for various transition states complex involved in concerted, two step and three step mechanisms catalyzed by [Cu(NH<sub>3</sub>)<sub>4</sub>(H<sub>2</sub>O)<sub>2</sub>]<sup>2+</sup>. Based on …
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Investigation of the Interface Recombination Velocity of Native Oxide/iii-V Semiconductor Interfaces
The activation energy of the IRV was extracted from variable temperature TRPL measurements performed on selected samples. The activation energies of the interface recombination velocities agreed with previously established results on unoxidized material interfaces.
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Organometallic Synthesis Kinetics of CdSe Quantum Dots
… rates followed Arrhenius behavior governed by activation energies, which were tailored by the choice of solvent. Synthesis in solvents, such as stearic acid, with lower activation energies produced faster initial nanocrystal growth and longer critical wavelengths. The highest photoluminescence …
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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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Atomic motion on the close-packed plane of a hexagonally close-packed metal
… of Re and W adatoms on Re (0001). Prefactors and activation energies to diffusion of $\rm6.13(\times2.6\sp{\pm1}){\times}10\sp{-6}\ cm\sp2/s,\ 11.11\pm.43$ kcal/mol and $\rm2.17(\times2.7\sp{\pm1}){\times}10\sp{-3}\ cm\sp2/s,\ 11.04\pm.34$ kcal/mol were measured for Re and W, respectively. The …
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Atomic motion on the close packed plane of a hexagonally close packed metal
… of Re and W adatoms on Re (0001). Prefactors and activation energies to diffusion of 6.13(x2.6±1 )x10-6 cffil. Is, 11.11±.43 kcal/mol and 2.17(x2.7±1)x10-3 cffil/s, 11.04±.34 kcal/mol were measured for Re and W, respectively. The large difference in prefactor values, the largest yet seen for two …
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Constrained sintering of gold circuit films on rigid substrates
… kinetics of the constrained gold films. The activation energies for densification of the porous gold films during isothermal sintering, were found to be 21.54±1.03 Kcal/mole and 45.12±1.6 Kcal/mole for freestanding and constrained gold films respectively. These values corresponded very well …
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The resistivity recovery of dilute alloys of silver, copper, and gold, proton irradiated at 80°K
… were then obtained from -130°C to 90°C and activation energies were determined every 10°C using the change of slope method. The order associated with the reaction kinetics was determined at temperatures appropriate for the various annealing peaks by fitting 2l.0 minute isothermal anneals to …
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A Study of Electron Traps in Vapor Phase Epitaxial Gallium-Arsenide Grown in the Presence of Oxygen (Dlts, Deep Level Transient Spectroscopy, Semiconductors, Defects)
… determination of deep level concentrations and activation energies. The design and construction of the automated measurement apparatus are described, and the computer programs for the data acquisition and analysis are included.
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A Thermogravimetric Study of the Pyrolytic Behaviour of South Wales Coals
… a series of temperature regions with their own activation energy. These regions and activation energies vary with the heating rate. It is suggested that each activation energy relates to a different kind of pyrolysis reaction, and although some suggestions have been made, further research …
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Thermally Generated Traps in Boron Implanted Phosphorus Doped Silicon (Semiconductor, Defect)
… emission rates, emission cross sections, and activation energies for two thermally generated hole traps and six thermally generated electron traps. These traps do not appear to be present in the silicon immediately after implantation; they are formed by heat treatment of the damaged silicon at …
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Thermal vacancies in HCP helium-4
Activation energies of thermal vacancies have been determined in hcp $\sp4$He as a function of molar volume. A sensitive strain gauge was used to measure the temperature dependence of the pressure in twenty crystals between 18.17 and 20.9 cm$\sp3$/mole. Absolute lattice parameters at low …
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Radiation-enhanced diffusion of oxygen-18 in uranium dioxide thin films
… an effect on RED and thermal diffusion. For RED, activation energies found from best fit analysis were Ea = 0.83 and Ea = 0.37, for single crystal and textured samples, respectively. RED for single crystal UO2 thin films can be represented by, D_RED=8.7×〖10〗^(-14) exp((-0.83)/kT) 〖cm〗^2/sec RED …
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Computing the energetic component of the charge-transfer symmetry factor
… the location of the transition state and activation parameters. The knowledge of the reaction coordinate is exploited in two ways: to compute activation parameters from umbrella integration (UI) and Marcus theory (MT) based simulations assuming linear response and to test the accuracy of …
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