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Showing 1 to 20 of 163 for “"Energy barrier"”.
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Development of novel methodologies to analyze the adsorption kinetics of nonionic surfactants
… rate-limiting step, and (2) the mixed diffusion-barrier controlled model, which hypothesizes the existence of an energy barrier for surfactant adsorption from the bulk solution to the surface, and assumes that both diffusion and the energy barrier determine the overall rate of surfactant …
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Energetics Calculation of {10-12} Twin Nucleation and Growth in Magnesium and Alloys using Density Functional Theory and Atomistic Simulation
… the initial systems. The result shows that the energy barrier for {"10" "1" ̅"2" } twin nucleation is approximately 33.5 meV/atom from the MEAM potential for pure Mg, which is close to 34.5 meV/atom from DFT calculation with 16 Mg atoms. The energy barrier for twin growth is approximately 12.2 …
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Metastability of Magnetic Nanoparticles in Magnetization Relaxation with Different Dynamics and Distributions of Magnetic Anisotropy
… state follows a modified-Arrhenius law where the energy barrier has a dependency on temperature and standard deviation of the distributions in addition to magnetic field and magnetic anisotropy. The magnetic anisotropy barrier is determined by the smallest particle within a given distribution. We …
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Investigation of transport mechanisms for n-p-n InP/InGaAs/InP double heterojunction bipolar transistors
… components. The potential distribution of the energy barrier constitutes a fundamental analytical concept and is employed for applying the diffusion, the thermionic emission, and the tunneling theories in investigating the injection mechanisms at the e-b heterojunction interface. The diffusion …
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Separation of Colloidal Particles in a Packed Column using Depletion Forces
… the binary dispersion measurements. Potential energy profiles between a PS particle and a flat silica plate were calculated. The secondary energy barrier for the 1.5 µm particles was two times greater than for the 0.82 µm particles. Hence, the 0.82 µm particles were more likely to overcome …
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A Time-Resolved Fluorescence Study of Silicon Nanoparticles: Testing the Dimer Stretching Model
… their simple stretching model produces an energy barrier inconsistent with the observed temperature-lifetime trends. The discrepancy is attributed to the neglect of more complicated dimer motions, e.g. hydrogen bond wagging.
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Probing Spin Glass Energy Landscapes with 1/f Noise
… and to the understanding of the underlying energy barrier distribution. Analysis of our measurements provides the first explicit determination of the evolution of the spin-glass energy barrier distribution as a function of film thickness and temperature. By fabricating samples of multiple …
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Skyrmions and Biskyrmions in Magnetic Films
… are topologically protected, so there is a large energy barrier preventing their annihilation. Furthermore, they can exist at the nanoscale, be manipulated with very small currents, and be created by a number of different methods. This makes them attractive for use in potential computing …
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On the relationship between carrier mobility and velocity in sub-50 mm MOSFETs via calibrated Monte Carlo simulation
… velocity at the source-channel potential energy barrier was investigated. The results show a strong correlation, as was demonstrated previously experimentally. Moreover, further proof is provided that the velocity at which carriers are injected from the source region in modem NMOSFET's is …
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Direct energy landscape sampling of the homogeneous nucleation and crystal growth of a model liquid
… processes involving the crossing of free-energy barriers. Attempts to capture the entire crystallization process over long timescales with molecular dynamic simulations have met major obstacles because of the temporal constraints of molecular dynamics. Herein, we circumvent this temporal …
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Exploring Downhill Protein Folding Free Energy Landscapes
… protein folding, i.e., folding with the free energy barrier comparable to the thermal energy kBT, is investigated by combining laser induced temperature-jump kinetics measurements and Langevin dynamics simulations. A kinetic and thermodynamic survey of multiple WW domain mutants is performed …
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FIRST-PRINCIPLES DENSITY FUNCTIONAL THEORY STUDIES OF REACTIVITIES OF HETEROGENEOUS CATALYSTS DETERMINED BY STRUCTURE AND SUBSTRATE
… the γ-Al<sub>2</sub>O<sub>3</sub> support, (2) energy barrier of H<sub>2</sub> dissociative adsorption over Mg clusters affected by its electronic structure, and (3) comparison of the activities of CeO<sub>2</sub> clusters affected by two different supports--monoclinic ZrO<sub>2</sub> and …
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A computational investigation of nucleation processes in organic crystals
… is an activated process, meaning that a free energy barrier must be overcome for the transition to take place, and the height of the free energy barrier determines the rate at which the process will occur. Despite considerable advances in both theoretical and experimental techniques to date, …
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DFT Studies of the Organocatalytic Aldol Reaction and a Frustrated Lewis Pair
… modeling and calculating the hydrogen activation energy barrier.
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Pore-scale Interfacial and Transport Phenomena in Hydrocarbon Reservoirs
… for meeting the society's ever-increasing energy demand and requires a thorough understanding of the multiphase interfacial and transport phenomena in these reservoirs. This dissertation performs pore-scale studies of interfacial thermodynamics and multiphase hydrodynamics in shale …
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Structural and Elastic Properties of Degenerate SnO Monolayers at Finite Temperature
… cell at zero temperature and a charge-tunable energy barrier that leads to a thermally-controllable structural phase change. Doped SnO monolayers with rectangular degenerate unit cells give rise to two-dimensional multiferroicity. Their two-dimensional elastic energy landscape adopts a basic …
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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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Investigating Dislocation Behavior in High Entropy Alloys Using Atomistic Simulations
… conventional alloys. Its negative stacking fault energy and high yield strength allows unique dislocation behavior. Also, the annealing temperature of NiCoCr system leads to a wide range of short range orders which directly affect the energy barrier of dislocation movement.[22] This work …
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Towards More Efficient Enhanced Sampling Methods To Study Phase Transitions
… can be identified by a singularity in the free energy or one of its derivatives. More modern classification of phase transitions relies on the order parameters as exemplified by the Landau's theory. An order parameter is a quantity that takes a value of zero in the disordered phase and assumes …
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LOW-DIMENSIONAL CHALCOGENIDE BASED THERMOELECTRIC COMPOSITES
… also create a high trap-state by introducing the energy barrier at the organic/inorganic interface, thus a high level of Seebeck coefficient is maintained while a remarkable improvement on electrical conductivity was achieved. To our best knowledge, we are the first group developing the flexible …
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