Materials Science and Engineering Commons^™

Spectroscopic, Thermal, And Physical Analysis Of The Raw Materials In Europium Doped Cesium Strontium Iodide Scintillator, Bonnie Dell Blalock

Masters Theses

Scintillators are widely used in homeland security applications that utilize gamma-ray spectroscopy. An ideal scintillator for this purpose should possess a high effective atomic number, high light yield, and good energy resolution. The scintillator CsSrI₃: Eu [cesium strontium iodide: europium], recently developed at the Scintillation Materials Research Center, has excellent properties. Recent efforts have been made to evaluate the basic thermal properties and IR spectra of the compound’s raw materials as part of a project to improve the quality of grown crystals. Fourier transform infrared spectroscopy of high purity anhydrous CsI [cesium iodide], SrI₂ [strontium iodide], and …

An Investigation Of Energy Migration In Rare Earth Oxyorthosilicate Scintillation Materials, Harold Edward Rothfuss

Doctoral Dissertations

In most scintillator applications, the energy resolution is an important scintillation property and is related to other scintillator properties. In order to observe how these properties relate to the energy resolution, a simulation was created to quantify most of these characteristics for a LSO:Ce scintillator. These results were validated with good agreement to experimental results. From the separable components of the simulation, an understanding of the contributions to the energy resolution broadening was developed. A thought to improve the energy resolution by improving the energy migration was tested by observing and modifying the scintillation kinetics of YSO:Ce. The scintillation kinetics …

Plasmonics Resonance Enhanced Active Photothermal Effects In Aluminum Nanoenergetics For Propulsion Applications, Jacques Abboud

Doctoral Dissertations

In this dissertation, aluminum nanoparticles (Al NPs) are shown capable to on-demand enhance and control the local photothermal energy deposition, both spatially and temporally, via active photothermal effects initiated by the localized surface plasmon resonance (LSPR) phenomenon, and amplified by the Al exothermal oxidation reactions. Experiments in dry and wet environments along with computational modeling of the photothermal process are very desirable for gaining fundamental understanding, ignition optimization and parameter exploration.

Combined phenomena of motion and ignition of Al NPs are explored first in this study. Both resulting from exposing a pile of the nanoenergetics in hand to a single …

Structural And Kinetic Studies Of Structure I Gas Hydrates Via Low Temperature X-Ray Diffraction And High Resolution Neutron Diffraction, Susan Michelle Everett

Doctoral Dissertations

Gas hydrates are materials of interest as sources for clean energy, carbon sequestration, greenhouse gas mitigation, and gas storage. This body of work presents two projects that each separately explore one aspect of the potential found in gas hydrates. Chapter 1 tackles the structural changes found to occur over the CO₂ [carbon dioxide] - CH₄ [methane] hydrate solid solution. The application here pertains to the sequestration of CO₂ in natural gas hydrates found in permafrost regions and ocean floors. As CO₂ is injected into the hydrate reservoir, CH₄ is released and recovered for energy use. …

Evaluation Of The Transient Thermal Performance Of A Graphite Foam/Phase Change Material Composite, Michael Paul Trammell

Masters Theses

The thermal transient response of graphite foam infiltrated with paraffin wax as a thermal protection composite was investigated. Graphite foam is a rigid open-celled porous carbon material that exhibits high thermal conductivity along the ligaments. To increase the ability of graphite foam to store heat energy, it was infiltrated with a phase change material, paraffin wax. Filling the foam with a phase change material (PCM) creates a composite that transfers heat through an interconnected network of ligaments to a large surface area of PCM for absorption. Foams were made at various pressures to understand the effect of porosity, which also …