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.
Results
Showing 1 to 20 of 49 for “"Transition State theory"”.
-
High Pressure Nmr Studies of the Dynamic Structure of Liquids
… the first experimental proof of the breakdown of transition state theory, thus confirming recent predictions of stochastic models for isomerization reactions in condensed phases. In these models it is proposed that there are dynamical effects on isomerization because the reaction coordinate is …
-
A multiscale model for the oxide ion conducting and proton conducting solid oxide cells
… a multiscale model combining density functional theory calculations, transition state theory and continuum modeling to elucidate the essential reaction steps and predict the performance of the device. Density functional theory calculations are used to obtain the free energy barriers for different …
-
Computational Analysis of Molecules and Chemical Reactions from Cheminformatic Databases
A large number of organic reactions feature post-transition state bifurcations. Selectivities in such reactions are difficult to analyse because they cannot be determined by comparing the energies of competing transition states. Molecular dynamics approaches can provide answers but are …
-
Illuminating reaction pathways in low-temperature combustion, pyrolysis & atmospheric oxidation
… first chapter corrects a longstanding issue in transition state theory by determining the proper symmetry in reactions with identical reactants and estimating the error from taking incorrect approach. The next chapter then applies transition state theory to develop high pressure limit and …
-
Ab initio determination of kinetics for atomic layer deposition modeling
… obtained from quantum-chemical studies. Using transition state theory and partition functions from statistical mechanics, equilibrium constants and reaction rates can be calculated. Several tools were created in Python to aid in the calculation of these quantities, and this procedure was …
-
Computational approaches to understand the atomistic drivers of enzyme catalysis
… reactivity has been contextualized through transition-state theory (TST), in which catalytic strategies are described by their ability to minimize the activation energy to cross the reaction barrier through a combination of ground-state destabilization (GSD) and transition-state …
-
Ab initio screening of lithium diffusion rates in transition metal oxide cathodes for lithium ion batteries
… in lithium ion battery cathodes is derived using transition state theory and common materials properties. The metric relies on net activation barrier for lithium diffusion. Several cathode materials are screened using this approach: [beta]'-LiFePO4, hexagonal LiMnBO3, monoclinic LiMnBO3, Li …
-
Supercritical Fluids: Kinetic Solvent Effect and the Correlation of Solid-Fluid Equilibria
… dimerization results were analyzed in terms of transition state theory using the Peng-Robinson equation. The slowing of the dimerization and the implications of this result for the general case of a reactive system in a supercritical solvent are discussed in terms of the relative sizes and …
-
Theoretical investigation of the kinetics and thermodynamics of conformational equilibrium in crowded medium
… of the Monte Carlo, extended scaled particle theory, and the transition state theory models is employed to compute the thermodynamic activities of three systems in virtually crowded media filled with polyethylene glycol molecules chosen from appropriately constructed conformational ensembles. …
-
Theoretical Study of oxygen reduction reaction (ORR) on poly-terthiophene
… poly-terthiophene by means of Density Functional Theory (DFT) computation. The calculations predict a large electron affinity of terthiophene (THP) of ~2.4 eV in aqueous phase that supports the idea that activation of the polymer catalyst occurs via an initial one-electron reduction step. The …
-
Density Functional Theory modeling of heterogeneous reactions of hydrocarbon intermediates on silicon carbide: surrogate kinetic model development for Chemical Vapor Infiltration
… on the substrate using Density Functional Theory is the key point of current research. By focusing on the adsorption, reaction, and desorption mechanisms that control SiC development, our method incorporates quantum mechanical models. Using Transition State Theory, the study examines …
-
Stress-mediated reaction pathways for dislocation nucleation in copper
… nucleation is well described in the framework of transition state theory as a stress-mediated, thermally activated process. We have used reaction pathway sampling methods and well-fit empirical potentials to determine the stress-dependent behavior of and atomistic mechanisms for dislocation …
-
Atomistic Study of Grain Boundary Sliding
… conjunction with Nudged Elastic Band (NEB) and Transition State Theory (TST) to do atomistic calculation. The observations in atomistic calculations, that the sliding rate is lower than the previous atomistic calculations by several orders of magnitude, has given a way to bridge the gap between …
-
A combined approach of electronic structure calculations and spectroscopy for elucidating reaction mechanisms in organic and bioinorganic systems
… thesis describes the use of density functional theory (DFT) to assist the interpretation of advanced spectroscopic techniques such as stopped flow Fourier transform infrared spectroscopy (FTIR), muon spin resonance (�SR), and nuclear inelastic scattering (NIS). These complementary techniques are …
-
Competitive Nucleation in Nanoclusters
… of the critical nucleus. In classical nucleation theory (CNT), the embryo size is solely used as the reaction coordinate, but this does not capture the formation of different structures in a competitive nucleation event. Competitive nucleation is modeled using a two dimensional Potts model …
-
Glassy models of protein folding
… of the model. The model has many metastable states and the distribution of the lifetimes of these states is log-normal at high temperatures and becomes much broader in the glassy phase. Also, we calculate the folding time by deriving a generalization of transition state theory that takes into …
-
Kinetic Studies of Hydroxyl and Hydrogen Atom Reactions
… fluorescence (LP-RF) technique. The transition state theory (TST) analysis coupled with the measurements support the suggestion that the reaction shows significant curvature in the Arrhenius plot. The LP-RF technique was also used to measure the rate constant of the H + CH3Br reaction …
-
Insights for designing mechanochromic spiropyrans from first principles dynamics and minimum energy pathways
… arrangement of reactant molecules on the ground state or place them on an excited state to surmount an energy barrier. An alternative and less well-explored way of initiating a chemical reaction is to use an applied force to distort the reactant molecules along a specific reaction coordinate. …
-
Predicting combustion properties of hydrocarbon fuel mixtures
… used to model combustion chemistry. I performed transition state theory calculations for several reactions that are critical in combustion, including a detailed analysis of the pressure dependence of these rate coefficients. I developed a new method for rapidly estimating the vibrational modes …
-
Developing fundamentally based models for autoignition
… the rate constants using the well-known transition state theory (TST). The effects of substituent, nature of radical center, and ring size were also studied. Generalized rate estimation rules for these reactions were derived for later use in automated generation of oxidation mechanisms. …
Page 1 of 3