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Full-Text Articles in Chemistry
Electron-Positron Annihilation Lifetime Spectroscopy Of Mgo And Aluminum-Doped Mgo, Elise Liebow
Electron-Positron Annihilation Lifetime Spectroscopy Of Mgo And Aluminum-Doped Mgo, Elise Liebow
Honors Theses
Radiation is a form of energy that can damage materials at an atomic level. This has implications for the mobility of radioactive waste through containment materials. We are characterizing atomic defects in materials by using Electron-Positron Annihilation Lifetime Spectroscopy (EPALS). When an electron and positron come into contact with each other, they annihilate and release two antiparallel 511-keV gamma rays. In a pristine crystalline sample, positrons can easily annihilate with electrons, but in a sample with vacancies/defects in the crystal structure, positrons take longer to annihilate. Therefore, the more vacancies in a sample, the longer the average lifetime of a …
Understanding Ice Mixtures Under Pluto Simulated Conditions And Their Implications For Geophysical Processes, Caitlin Joannah Ahrens
Understanding Ice Mixtures Under Pluto Simulated Conditions And Their Implications For Geophysical Processes, Caitlin Joannah Ahrens
Graduate Theses and Dissertations
New Horizons at Pluto has given the planetary science community the first images of Pluto’s surface, including geologic wonders and compositional variability. Methane, nitrogen, and carbon monoxide make up the bulk of the volatile plutonian surface along with water ice. In this work, these three main volatiles are specifically investigated in the laboratory setting to understand the spectral properties and behavior of binary and ternary mixtures. The spectra are taken in the near-infrared wavelengths (1 – 2.5 µm) using Fourier transform infrared (FTIR) spectroscopy techniques utilizing the Pluto Simulation Chamber housed at the University of Arkansas, which can reach conditions …