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Full-Text Articles in Physical Sciences and Mathematics

Bedrock Mapping Using Shear Wave Velocity Characterization And H/V Analysis, James P. Gonsiewski Jan 2015

Bedrock Mapping Using Shear Wave Velocity Characterization And H/V Analysis, James P. Gonsiewski

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An experiment was conducted to constrain the HVSR (Horizontal to Vertical Spectral Ratio) or H/V spectral ratio method at a glaciated site in northeast Ohio. Multiple methods were used to determine the shear wave velocity (Vs) and depth (h) to bedrock in relation to the fundamental resonant frequency (fo) determined from 3-component seismic data, as defined by the relationship f0=Vs/4h. The shear wave velocity structure was determined at three sites using MASW (Multi-channel Analysis of Surface Waves) and shear wave refraction methods, and the fundamental resonant frequency was passively observed using 3-component Guralp broadband seismometers. The …


A Computational Study Of A Photovoltaic Compound Parabolic Concentrator, William M. Vance Jan 2015

A Computational Study Of A Photovoltaic Compound Parabolic Concentrator, William M. Vance

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Routines have been written and added to the Wright State developed solar system simulation program called Solar_PVHFC to model incident solar radiation for a compound parabolic concentrator (CPC) that uses solar panels (photovoltaic panels) to produce electrical energy. Solar_PVHFC is a program that models a solar energy system composed of solar panels to produce electricity from the sun, hydrogen storage tanks to chemically store the energy produced by the solar panels, and fuel cells to convert between electrical and chemical energy when required. Solar_PVHFC features several adjustable parameters to model a solar panel, hydrogen storage, and fuel cell system. Now …


Algal Quality Controls The Distribution, Behavior And Growth Of Algivorous Cichlids In Lake Tanganyika, Renalda Nanziga Munubi Jan 2015

Algal Quality Controls The Distribution, Behavior And Growth Of Algivorous Cichlids In Lake Tanganyika, Renalda Nanziga Munubi

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The nutritional value of primary producer is dependent on the concentrations of C, N and P. These elements are the building blocks for protein, carbohydrates, lipids, nucleic acids and other biochemical compounds. The balance between the supply of dietary elements and the herbivore's demand is crucial for the growth of algivorous organisms, including fish. However, anthropogenic changes in primary producer quality due to sediments may alter the value and quantity of food in the littoral zone of Lake Tanganyika, which may affect both herbivorous near shore and pelagic fisheries. This dissertation focuses on the influence of algae food on herbivore …


Growth Of Sparingly-Soluble Ab-Type Minerals As A Function Of Their A:B Ratio, Jacquelyn N. Bracco Jan 2015

Growth Of Sparingly-Soluble Ab-Type Minerals As A Function Of Their A:B Ratio, Jacquelyn N. Bracco

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A fundamental understanding of mineral growth kinetics is necessary to predict mineral reactivity in geologic environments. We use hydrothermal atomic force microscopy (HAFM) to measure step advance speeds and morphological evolution of the sparingly-soluble minerals magnesite (MgCO3), barite (BaSO4) and celestite (SrSO4) while systematically varying the concentrations of their constituent cations and anions in solution. For all three minerals, a maximum step velocity is reached at an aqueous cation:anion concentration (r) near unity and decreases with extreme r despite order of magnitude differences in the water exchange rate for the cations comprising the minerals. Affinity based models fail to reproduce …


Accelerated Degradation Of Chlorinated Solvents By Nanoscale Zero-Valent Iron Coated With Iron Monosulfide And Stabilized With Carboxymethyl Cellulose, Shirin Ghahghaei Nezamabadi Jan 2015

Accelerated Degradation Of Chlorinated Solvents By Nanoscale Zero-Valent Iron Coated With Iron Monosulfide And Stabilized With Carboxymethyl Cellulose, Shirin Ghahghaei Nezamabadi

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Nanoscale zero-valent iron (nZVI) injections have proven to be a promising approach for the remediation of aquifers contaminated by chlorinated organic pollutants. This study compares the efficacy of nZVI in sulfidated and unamended forms in degrading selected chlorinated hyrocarbons (CHCs). Results show that nZVI amended with iron monosulfide (FeS) increases the rate of dechlorination of CT, CF and 1,1,1-TCA compared to that by unamended nZVI. The focus of this research was to characterize degradation kinetics and degradation byproduct distributions of CT, CF and 1,1,1-TCA by nZVI coated by iron monosulfide, which is represented as nZVI/FeS. To prevent nZVI particles from …


Atmospheric Effects On Radar/Ladar Detection Of Seismic Activity, Michelle Frances Via Jan 2015

Atmospheric Effects On Radar/Ladar Detection Of Seismic Activity, Michelle Frances Via

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This thesis investigates how well ground vibrations can be detected at ladar or radar wavelengths and how the atmosphere may impact the observation of such activity. First understanding atmospheric hindrances at each of these wavelengths is helpful to prioritize by those yielding best transmission results. A prerequisite to the outdoor field experiment performed for this study involves analyzing atmospheric effects characterization at six probable wavelengths using the Laser Environmental Effects Definition and Reference tool (LEEDR) developed by the Air Force Institute of Technology's (AFIT) Center for Directed Energy (CDE). These wavelengths, selected from the shortwave infrared and microwave portions of …


Processing And Interpretation Of Three-Component Borehole/Surface Seismic Data Over Gabor Gas Storage Field, Li Wei Jan 2015

Processing And Interpretation Of Three-Component Borehole/Surface Seismic Data Over Gabor Gas Storage Field, Li Wei

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Analysis of a seismic dataset recorded as part of a collaborative project between Wright State University, Spectraseis, Precision Geophysical, and Dominion East Ohio over the Gabor gas storage field, Canton, Ohio, is the topic of this study. Two types of sources (vibroseis and small seismic shot-holes) as well as three types of recording systems (passive 3C broadband on the surface, experimental 3C borehole sondes, and conventional 2D surface geophone profiles) were employed with different purposes. The shot hole explosives were calibration check-shots for the 3C borehole array repeatedly deployed at multiple levels. The vibrators of the conventional 2D seismic profiles …


Determination Of Vp, Vs, Glacial Drift Thickness And Poisson's Ratio At A Site In Jay County, Indiana, Using Seismic Refraction And Multichannel Analysis Of Surface Wave (Masw) Analysis On A Common Data Set, Shamim Ahammod Jan 2015

Determination Of Vp, Vs, Glacial Drift Thickness And Poisson's Ratio At A Site In Jay County, Indiana, Using Seismic Refraction And Multichannel Analysis Of Surface Wave (Masw) Analysis On A Common Data Set, Shamim Ahammod

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In July 2013, an industry-scale seismic reflection survey was conducted at a site in northern Jay County, Indiana, by geophysics students and faculty of Wright State University. As a part of that effort, a separate near-surface seismic dataset was collected to examine the Vp, Vs, and Poisson's Ratio of the glacial drift and upper bedrock. This near-surface study successfully used a common dataset that was separately analyzed for both Vp (seismic refraction) and Vs (MASW) to calculate the Poisson's Ratio of the glacial drift and underlying bedrock. The driller's log for a water well near the east end of this …


Accelerated Degradation Of Chlorinated Solvents By Copper-Modified Nanoscale Zero Valent Iron (Cu-Nzvi) Stabilized With Carboxymethyl Cellulose, Andrew Franze Jan 2015

Accelerated Degradation Of Chlorinated Solvents By Copper-Modified Nanoscale Zero Valent Iron (Cu-Nzvi) Stabilized With Carboxymethyl Cellulose, Andrew Franze

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Nanoscale zero valent iron (nZVI) is a remediation technology that can be used to treat chlorinated hydrocarbons (CHCs) in contaminated aquifers. Nanoparticles remain mobile in water and can be transported with groundwater flow to contaminated zones. However, due to magnetic and van der Waals forces, unstabilized nZVI agglomerates. Carboxymethylcellulose (CMC) was used as a polyelectrolyte stabilizer in this study. nZVI serves as an electron donor and can dechlorinate CHCs. nZVI reactivity with CHCs can be enhanced by addition of a secondary metal catalyst. This study evaluates the potential of copper amended nZVI (Cu-nZVI) to degrade select CHCs. The objective of …


Stability Of Monomethylmercury In Water, Sarah Elyse Harvey Jan 2015

Stability Of Monomethylmercury In Water, Sarah Elyse Harvey

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Monomethylmercury (MMHg) bioaccumulates in aquatic food webs, leading to concentrations in fish that increase health risks for humans who consume fish. As a result of processes that produce and decompose it, MMHg concentrations are notoriously unstable in many natural waters. I examined the stability of MMHg in both filter-sterilized (< 0.1 µm) reagent-grade water and 0.22-µm filtered sediment pore water from Grand Lake St. Marys, Auglaize and Mercer Counties, Ohio, each at three MMHg treatment concentrations (1, 5, and 50 ng/L). Reagent-grade water samples were incubated under both light and dark conditions at either 5 or 26 °C for 112 days. Pore water samples were incubated in the dark at 26 °C, mimicking environmental conditions, for a period of 98 days. Decay constants (± 95% CI) for solutions containing either 1 or 5 ng/L MMHg in reagent-grade water ranged from 0.0009 ± 0.0013 to 0.1225 ± 0.0150 d-1, with greater decay constants at higher temperature and no significant effect of light exposure. In contrast, decay constants for 50 ng/L MMHg in reagent-grade water were much less than those in more dilute solutions, ranging from 0.0018 ± 0.0015 to 0.0055 ± 0.0023 d-1, with both light and temperature influencing MMHg decomposition. Decay constants of MMHg in pore water were found to be independent of initial concentration of MMHg; however, decay constants in pore water samples were 3-fold higher than those in reagent-grade water amended with the same initial concentration (p = 0.007). These results suggest that natural constituents in pore water accelerate MMHg decay reactions.


Dna-Nucleobase Guanine As Passivation/Gate Dielectric Layer For Flexible Gfet-Based Sensor Applications, Adrienne Dee Williams Jan 2015

Dna-Nucleobase Guanine As Passivation/Gate Dielectric Layer For Flexible Gfet-Based Sensor Applications, Adrienne Dee Williams

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The main goal of this dissertation was two-fold: first, to study and design a graphene-based transistor environmentally friendly by replacing a standard substrate and gate dielectric with different flexible/rigid and biodegradable films and secondly, to study their effects on graphene's charge carrier mobility. A thin film of deoxyribonucleic acid nucleobase purine guanine deposited by physical vapor deposition onto up to ten layers of graphene that were transferred onto various rigid and flexible substrates was characterized more thoroughly. Several test platforms were fabricated with guanine 1) as a standalone gate dielectric, 2) as the control and 3) as a passivation layer …


Verification And Validation Of A Transient Heat Exchanger Model, Jayme Lee Carper Jan 2015

Verification And Validation Of A Transient Heat Exchanger Model, Jayme Lee Carper

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A statistical based verification and validation process is applied to the transient modeling of a shell and tube heat exchanger. A generic model of a heat exchanger was developed based on first principles as a sub-system of a larger thermal system model. This model was originally created without any experimental data, as it was not readily available. To provide the data necessary to apply the validation process, a thermal emulator was designed and built that allowed control of all system inputs to the heat exchanger, while also providing the instrumentation to record all required data. A wide test matrix was …


Relating Reactive Transport To Hierarchical And Multiscale Sedimentary Architecture, Mohamad Reza Soltanian Jan 2015

Relating Reactive Transport To Hierarchical And Multiscale Sedimentary Architecture, Mohamad Reza Soltanian

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This dissertation addresses the transport of reactive solutes in groundwater. The goal is to better link reactive transport processes to what is known about sedimentary architecture. New forms of Lagrangian-based models for the processes of retardation and dispersion are derived through linking the models to hierarchical and multiscale sedimentary architecture. This allows for a fundamental understanding of how these processes arise from the hierarchical architecture of sedimentary facies, and allows for a quantitative decomposition of these processes into facies-related contributions at different scales within the hierarchy.

The main focus is on reactive transport characterized by a high Damkohler number, DN, …


Water Quality Of The Upper Little Miami River Watershed In Ohio: Impacts Of Natural And Anthropogenic Processes, David Allan Huff Jan 2015

Water Quality Of The Upper Little Miami River Watershed In Ohio: Impacts Of Natural And Anthropogenic Processes, David Allan Huff

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Stream water quality is increasingly threatened by expanding anthropogenic activities, mainly through point source discharges and urban and agricultural runoffs of contaminants getting through a water body's watershed resulting in pollution. Concerns developed as to whether urban or agricultural type activities were causing most water quality impairment issues in the upper Little Miami River watershed in southwest Ohio.

Characterizing the upper Little Miami River (LMR) watershed with respect to water chemistry and Land Use/Land Cover (LULC) while evaluating the sources of any higher than expected natural parameter concentrations, with a strong emphasis on the nutrients phosphorus and nitrate, serves as …


Cometabolic Biodegradation Of Halogenated Aliphatic Hydrocarbons By Ammonia-Oxidizing Microorganisms Naturally Associated With Wetland Plant Roots, Ke Qin Jan 2015

Cometabolic Biodegradation Of Halogenated Aliphatic Hydrocarbons By Ammonia-Oxidizing Microorganisms Naturally Associated With Wetland Plant Roots, Ke Qin

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Bench-scale microcosms with wetland plant roots were investigated to characterize the microbial contributions to contaminant degradation of halogenated aliphatic hydrocarbons (HAHs) with ammonium. The batch system microcosms consisted of a known mass of wetland plant roots in aerobic growth media where the roots provided both an inoculum of root-associated ammonium-oxidizing microorganisms and a microbial habitat. Aqueous growth media, ammonium, and HAHs including trichloroethene (TCE), cis-1,2-dichloroethene (cis-DCE), chloroform (CF), 1,1,2-trichloroethane (1,1,2-TCA), ethylene dibromide (EDB, or 1,2-dibromoethane, 1,2-DBA) and 1,2-dichloroethane (1,2-DCA) were replaced weekly in batch microcosms while retaining roots and root-associated biomass.

Molecular biology results indicated that ammonium-oxidizing bacteria (AOB) were …


Evaluating Threats To The Rare Butterfly, Pieris Virginiensis, Samantha Lynn Davis Jan 2015

Evaluating Threats To The Rare Butterfly, Pieris Virginiensis, Samantha Lynn Davis

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Humans have caused drastic changes in ecosystems and communities through their modification of the natural landscape. Rare species, often highly specialized, are more impacted by these changes. Pieris virginiensis is a rare butterfly native to eastern North America that is a species of concern due to negative influences from habitat loss and plant invasion. This thesis discusses several threats to P. virginiensis, including habitat loss, climate change, competition, and the cascading effects of a novel European invasive plant, Alliaria petiolata, that attracts oviposition but does not allow for larval survival.

First, I examined a local extinction event and …


World-Wide Body Size Patterns In Freshwater Fish By Geography, Size Class, Trophic Level, And Taxonomy, Shishir Adhikari Jan 2015

World-Wide Body Size Patterns In Freshwater Fish By Geography, Size Class, Trophic Level, And Taxonomy, Shishir Adhikari

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The unifying themes of my thesis are patterns in world-wide freshwater fish body sizes and their underlying mechanisms. First, I explored Bergmann's rule in unprecedented detail, which states that body size is negatively correlated to temperature. Categorizing species by body size into quantiles and by trophic levels, I regressed the classes against latitude, temperature, seasonality, minimum temperature and habitable space. I found that Bergmann's rule applies to freshwater fish in general but the strength varies by size class and trophic levels. I concluded that Bergmann's rule in fish is driven by the exclusion of small fish from cold climate due …