Physical Sciences and Mathematics Commons^™

A Geophysical Investigation To Locate Missing Graves Utilizing Ground Penetrating Radar, Electromagnetic, And Magnetic Methods, Jared Wyatt Shank

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Old cemeteries often have graves that are unmarked because gravestones are missing or degraded and the graves are in areas for which maps or other historical documents are incomplete. This is the case for one cemetery in southwestern Ohio, known as Stevenson Cemetery, which contains graves of Revolutionary War and War of 1812 veterans. The immediate goal of this study is to locate unmarked graves in this cemetery using geophysical techniques. The broader goal is to evaluate three geophysical techniques to determine the effectiveness of each.

The three geophysical techniques evaluated in this study are magnetics, electro-magnetics, and ground-penetrating radar. …

Quantitative Analysis Of The Polarity Reversal Pattern Of The Earth's Magnetic Field And Self-Reversing Dynamo Models, Patrick Shane Craig

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The geologic record documents that the Earth's magnetic field has reversed 284 times over the past 160 Myr. This study uses two methods to analyze the scaling properties of the pattern of geomagnetic reversals and to analyze the scaling properties of reversals output by two mathematical self-reversing dynamo models, the Rikitake (1958) two-disk dynamo and the magnetohydrodynamic (MHD) model of Driscoll and Olson (2011). The first analysis method plots the duration versus cumulative probability for geomagnetic polarity intervals ranging between 0.01 and 35 Myr. The Kolmogorov-Smirnov statistic is used to determine the optimal minimum value of xmin at which power …

Palaeoecological Analysis Of The Decline In Stromatolite Abundance During The Ordovician Period, Noran Mhm El-Sherif

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A stromatolite is a laminated benthic microbial deposit. Its uniqueness arises from being present since the Precambrian to the present. Stromatolites recorded a peak time during the Mesoproterozoic, subsequently they witnessed abrupt rises and falls in abundance with the steepest decline in the Ordovician period, from which it never recovered from. There is no consensus yet regarding the reasons behind the decline of stromatolites. Thus the decline of these microbial deposits remains an enigma. Additionally, a literature gap exists regarding the reasons that specifically led to the Ordovician decline. Accordingly, the focus of this literature-based MSc. thesis is to find …

Abiotic Degradation Of Chlorinated Hydrocarbons (Chcs) With Zero-Valent Magnesium (Zvm) And Zero-Valent Palladium/Magnesium Bimetallic (Pd/Mg)-Reductant, Fang Yu

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Chlorinated hydrocarbons (CHCs) in groundwater can be treated by monometallic and bimetallic metal reductants through abiotic degradation. The breakdown of CHC is achieved by gaining electrons from those reductants and removing chlorines from CHC molecules to transform the CHCs into less chlorinated compounds. As a proven technology in groundwater treatment, permeable reactive barriers (PRBs) have been used to passively treat contaminated groundwater, in which granular metals can be used as reactive materials. This study explored the abiotic degradation of CHCs by zero-valent magnesium (ZVM) and bimetallic palladium/magnesium (Pd/Mg) reductants. Different CHCs (carbon tetrachloride, chloroform, dichloromethane (DCM), 1,2-dichloroethane (1,2-DCA), 1,1,2-trichloroethane (1,1,2-TCA), …

Enhanced Resolution Of The Paleoenvironmental And Diagenetic Features Of The Silurian Brassfield Formation, Lisa Marie Oakley

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The Brassfield Formation is an early Silurian (Aeronian, Llandoverian) unit of limestone and dolostone with excellent preservation of early reef communities and a diverse invertebrate fauna. A well-preserved outcrop occurs in southwestern Ohio at the Oakes Quarry Park in Fairborn; it contains abundant corals and stromatoporoids that are co-dominant in reef and reef-affected settings. This research provided an enhanced perspective of the Brassfield Formation to better reconstruct its paleoenvironment and better understand its diagenetic features. The depositional and diagenetic features of the Brassfield are described and interpreted using histologic methods and light microscopy. Selected thin sections were treated with carbonate …

Abiotic Reduction Of Nitrite And Nitrate By Nanoscale Chemogenic Magnetite: Pathways For Significant Greenhouse Gas Production, Adam Charles Burdsall

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The biogeochemical cycling of nitrogen in terrestrial systems is a major source of nitrous oxide (N₂O), which is among key greenhouse gases (GHG). While biotic processes are commonly accepted as the major drivers of N₂O production, the role of abiotic processes is less understood, and their importance may be underestimated. This study investigates abiotic reactions in the formation and breakdown of N trace gases, including nitric oxide (NO) and nitrous oxide (N₂O) by naturally occurring nanoscale magnetite in soil as denitrification (reduction of nitrite) intermediates. Nitrogen biogeochemical cycling has been studied extensively with respect …

Copper And Nickel Partitioning With Nanoscale Goethite, Kelsey Marie Danner

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Goethite is an ideal sorbent for investigations of metal partitioning with iron oxyhydroxides because it is the most abundant iron oxyhydroxide in sediments (Langmuir, 1997; van der Zee et al., 2003), and cations have a strong affinity for goethite (Coughlin and Stone, 1995). Steady-state partitioning of nickel (Ni) and copper (Cu) to nanoscale goethite (a-FeOOH) was investigated experimentally under conditions intended to be representative of those in natural waters. Manipulated conditions included i) sorbent mass, ii) solute metal concentration, iii) reaction time, iv) pH, v) ionic strength (I), and vi) humate concentration (competitive ligand) to examine how these factors influenced …

Trace Metals In Sediments On The Continental Margin Of The Northwest Atlantic Ocean, Daniel L. Marsh

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Trace metals in the ocean are derived from natural and anthropogenic sources. Despite increased human impact on the marine environment and biological productivity of continental margins, trace metal studies in marine sediments have focused primarily on near-shore regions. I investigated 22 metals in sediments on the continental margin of the northwest Atlantic Ocean to calculate enrichment factors (EF) relative to upper continental crust and identify spatial variations with distance from shore and depth below the sediment-seawater interface. Metals were well correlated with Al, Fe, organic matter, or CaCO3. No clear trends in metal EFs with distance from shore were evident …

Post-Emplacement Leaching Behaviors Of Nano Zero Valent Iron Modified With Carboxymethylcellulose Under Simulated Aquifer Conditions, Leslie Lavinia Williams

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Nanoscale particles of zero valent iron stabilized with carboxymethylcellulose (CMC-nZVI) have been shown to degrade chlorinated hydrocarbons efficiently in bench-scale investigations. The remediation of contaminated sites by subsurface injection of stabilized nZVI in a slurry form has been investigated at pilot scale and field scale with conflicting results concerning transport of stabilized nZVI and its long-term stability for in situ degradation of chlorinated hydrocarbons. Changes in the hydraulic conductivity in porous media have also been reported following injection of stabilized nZVI slurry in both large tank experiments and in field studies. This study investigated the leaching behavior of CMC-nZVI post-emplacement …