Physical Sciences and Mathematics Commons^™

Production And Adsorption Of Volatile Tellurium Hexafluoride, Stephanie H. Bruffey

Doctoral Dissertations

Research and development supporting the management of off-gases from nuclear fuel reprocessing has historically been focused on the off-gas streams that arise from aqueous reprocessing technology. With the advent of advanced reactor designs off-gas streams arising from advanced reprocessing methodology, such as that of FV [fluoride volatility] processing, also merit consideration. This work focuses on TeF₆ [tellurium hexafluoride], one of the most volatile radioactive compounds produced during FV, and investigates TeF₆ production, measurement, and abatement technologies.

To assist in on-line monitoring of TeF₆ by Fourier-transformed infrared spectroscopy, this work systematically used the ideal gas law and Beer’s …

Lithium-Aluminum Layered Double Hydroxide Chlorides: Structural And Thermodynamic Studies To Understand Dynamics, Functionality, And Applications In Lithium Adsorption, Samuel Frederi Evans

Doctoral Dissertations

No abstract provided.

Thermodynamics Of Short Chain Perfluoroalkanes Adsorbed On The Surfaces Of The Graphite Basal Plane And Mgo (100), Nathaniel Keenan Bass

Doctoral Dissertations

Molecular adsorption of short-chain linear perfluoroalkanes was studied by volumetric isotherm and by molecular dynamics simulation. Isotherms of perfluoroethane, perfluoropropane, and perfluorobutane gas were measured on clean surfaces of the graphite basal plane nanometer-scale cubic magnesium oxide (100). Each system was measured over a range of temperatures, and thermodynamic determinations of the entropies, enthalpies, and heats of adsorption were determined as a result. Potential phase transitions between the surface structures were identified, and the constant-coverage heats of adsorption for each system were determined. Comparisons to molecular dynamics simulations provided guidance in the assignment of phase diagrams, giving insights to the …

Alkane Adsorption On Mgo(100): Volumetric Isotherm, Inelastic Neutron Scattering, And Computational Studies, Andrew Spencer Hicks

Doctoral Dissertations

Volumetric adsorption isotherms and computational molecular dynamics (MD) simulations were performed for nonane and decane adfilms on MgO(100) nanocubes. From the isotherms, variety of thermodynamic quantities are calculated. These values, along with visual inspection of the isotherms, indicate a layer by layer trend from 2D to 3D behavior. This is attributed to the increasing importance of vertical adsorbate-adsorbate interactions as distance from the surface increases. Additionally, a 2D phase transition is observed for the first adsorbed layer as indicated by the evolution of the widths of the isotherm first derivative peaks. These experimental results are complemented by the MD calculations, …

Adsorption Of Hydrogen Onto Bare And Metal Decorated Metal Oxides, Paige Elizabeth Landry

Doctoral Dissertations

Catalytically relevant metal clusters were deposited on metal oxide supports. Palladium and gold were deposited on mixed morphology ZnO, and palladium was deposited on MgO(100). The materials were characterized with electron microscopy, photoluminescent spectroscopy, and X-ray photoelectron spectroscopy. The behavior of hydrogen on these materials, as well as bare ZnO, was studied using volumetric isotherms. The isotherms were used to determine the monolayer gas coverage, surface

area, and heats of adsorption of hydrogen on these materials over the temperature range of approximately 8-13 K. At the temperatures and pressures studied, hydrogen physically adsorbed onto the materials. Additional investigations with inelastic …