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Full-Text Articles in Physics

The Aging And Impacts Of Atmospheric Soot: Closing The Gap Between Experiments And Models, Ogochukwu Yvonne Enekwizu Dec 2020

The Aging And Impacts Of Atmospheric Soot: Closing The Gap Between Experiments And Models, Ogochukwu Yvonne Enekwizu

Dissertations

The main goal of this dissertation is to generate data and parameterizations to accurately represent soot aerosols in atmospheric models. Soot from incomplete combustion of fossil fuels and biomass burning is a major air pollutant and a significant contributor to climate warming. The environmental impacts of soot are strongly dependent on the particle morphology and mixing state, which evolve continuously during atmospheric transport via a process known as aging. To make predictions of soot impacts on the environment, most atmospheric models adopt simplifications of particle structure and mixing state, which lead to substantial uncertainties. Using an experimentally constrained modeling approach, …


Studying Near-Critical And Super-Critical Fluids In Reduced Gravity, Christian Hawkins, Ana Oprisan, Carole Lecoutre-Chabot, Yves Garrabos, Daniel Beysens Aug 2019

Studying Near-Critical And Super-Critical Fluids In Reduced Gravity, Christian Hawkins, Ana Oprisan, Carole Lecoutre-Chabot, Yves Garrabos, Daniel Beysens

Journal of the South Carolina Academy of Science

Critical and supercritical fluids have a variety of applications, from use as machine lubricants in high pressure or high temperature environments to the manufacturing of materials such as aerogel. The optical properties of fluids undergo rapid changes near the critical point resulting in a rapid increase in turbidity known as critical opalescence. These optical changes can be used to probe the universality of critical behavior. As a fluid approaches the critical point, the compressibility rapidly increases. In a gravitational field, this increase in compressibility leads to near-critical fluids stratifying by phase and density, making it difficult to observe the optical …


Analysis Of The Red And Green Optical Absorption Spectrum Of Gas Phase Ammonia, Nikolai F. Zobov, Phillip A. Coles, Roman I. Ovsyannikov, Aleksandra A. Kyuberis, Robert J. Hargreaves, Peter F. Bernath, Jonathan Tennyson, Sergei N. Yurchenko, Oleg L. Polyansky Jan 2018

Analysis Of The Red And Green Optical Absorption Spectrum Of Gas Phase Ammonia, Nikolai F. Zobov, Phillip A. Coles, Roman I. Ovsyannikov, Aleksandra A. Kyuberis, Robert J. Hargreaves, Peter F. Bernath, Jonathan Tennyson, Sergei N. Yurchenko, Oleg L. Polyansky

Chemistry & Biochemistry Faculty Publications

Room temperature NH3 absorption spectra recorded at the Kitt Peak National Solar Observatory in 1980 are analyzed. The spectra cover two regions in the visible: 15,200 - 15,700 cm-1 and 17,950 - 18,250 cm-1. These high overtone rotation-vibration spectra are analyzed using both combination differences and variational line lists. Two variational line lists were computed using the TROVE nuclear motion program: one is based on an ab initio potential energy surface (PES) while the other used a semi-empirical PES. Ab initio dipole moment surfaces are used in both cases. 95 energy levels with J = 1 …


Exchange Mechanisms In Macroscopic Ordered Organic Magnetic Semiconductors, Naveen Rawat Jan 2015

Exchange Mechanisms In Macroscopic Ordered Organic Magnetic Semiconductors, Naveen Rawat

Graduate College Dissertations and Theses

Small molecule organic semiconductors such as phthalocyanines and their derivatives represent a very interesting alternative to inorganic semiconductor materials for the development of flexible electronic devices such as organic thin field effect transistors, organic Light Emitting Diodes and photo-voltaic cells. Phthalocyanine molecules can easily accommodate a variety of metal atoms as well in the central core of the molecule, resulting in wide range of magnetic properties. Exploration of optical properties of organic crystalline semiconductors thin films is challenging due to sub-micron grain sizes and the presence of numerous structural defects, disorder and grain boundaries. However, this can be overcome by …