Digital Commons Network^™

Advancing High Spatial And Spectral Resolution Remote Sensing For Observing Plant Community Response To Environmental Variability And Change In The Alaskan Arctic, Sergio Armando Vargas

Open Access Theses & Dissertations

The Arctic is being impacted by climate change more than any other region on Earth. Impacts to terrestrial ecosystems have the potential to manifest through feedbacks with other components of the Earth System. Of particular concern is the potential for the massive store of soil organic carbon to be released from arctic permafrost to the atmosphere where it could exacerbate greenhouse warming and impact global climate and biogeochemical cycles. Even though substantial gains to our understanding of the changing Arctic have been made, especially over the past decade, linking research results from plot to regional scales remains a challenge due …

Bragg Gratings In Polarization Maintaining Optical Fiber As Three Dimensional Strain Sensor, Joel Quintana

Open Access Theses & Dissertations

Fiber-Bragg Gratings (FBG) for Structural Health Monitoring (SHM) have been studied extensively as they offer electrically passive operation, electromagnetic interference (EMI) immunity, high sensitivity and multiplexing as compared to conventional electric strain sensors. FBG sensors written within polarization maintaining (PM) optical fiber offer ad- ditional dimensions of strain measurement, greatly reducing the number of sensors needed to properly monitor a structure. This reduction however, adds complexity to the dis- crimination of the sensorâ??s optical response to its corresponding applied strains. This Dissertation defines the set of algorithms needed to measure planar strain using PM-FBGs exclusively. It defines the minimum number …

Imaging Live Drosophila Brain With Two-Photon Fluorescence Microscopy, Syeed Ehsan Ahmed

Open Access Theses & Dissertations

Two-photon fluorescence microscopy is an imaging technique which delivers distinct benefits for in vivo cellular and molecular imaging. Cyclic adenosine monophosphate (cAMP), a second messenger molecule, is responsible for triggering many physiological changes in neural system. However, the mechanism by which this molecule regulates responses in neuron cells is not yet clearly understood. When cAMP binds to a target protein, it changes the structure of that protein. Therefore, studying this molecular structure change with fluorescence resonance energy transfer (FRET) imaging can shed light on the cAMP functioning mechanism. FRET is a non-radiative dipole-dipole coupling which is sensitive to small distance …

Self-Interaction Corrected Polarizabilities Of Small Molecules, Sharmin Akter

Open Access Theses & Dissertations

Density Functional Theory (DFT) is one of the most successful and popular computational Quantum Mechanical approaches to understand materials. DFT allows the prediction of material properties from the electron density. Although in principle density functional theory is exact, it, however, relies on approximate functional for exchange-correlation energy. Due to the approximate nature of the exchange-correlation functional, the self-Coulomb energy of the electrons is not exactly canceled out by the self-exchange leading the spurious self-interaction error (SIE). This error is responsible for the unphysical orbital energies of DFT and delocalization of the orbitals. The orbital energies of the valence electrons are …

Studies Of Direct Solar Irradiance And Aerosol Optical Depth Using An Mfrsr And A Microtop Sunphotometer In The El Paso-Juarez Airshed, Arjun Aryal

Open Access Theses & Dissertations

The study of Solar Irradiance and Aerosol Optical Depth (AOD) plays an important role in understanding the regional and global climate distribution, and is also important in air pollution studies. In this work an MFRSR (Multi-Filter Rotating Shadowband Radiometer) and a Portable Microtop Sunphotometer were used to measure irradiances and to obtain optical depth values for the El Paso-Juarez Airshed. The Langley method applied on the MFRSR irradiance data was used to calculate the AOD values. The spatial distribution of AOD for this region was obtained using a Microtop Sunphotometer. The graphs were generated using GIS Shapefiles. In addition, the …

Depositional Controls And Sequence Stratigraphy Of Lacustrine To Marine Transgressive Deposits In A Rift Basin, Lower Cretaceous Bluff Mesa, Indio Mountains, West Texas, Andrew Anderson

Open Access Theses & Dissertations

Successful hydrocarbon exploration in former rift basins of the South Atlantic pre-salt has generated interest in understanding depositional, diagenetic, and stratigraphic controls on pre-salt deposits. However, most studies to date have focused on attributes and controls on presalt lacustrine carbonate reservoir systems and little work has been done on the overlying marine sealing facies. Currently our standard sequence stratigraphic model of marine transgression of rift systems involves a single pulse of marine flooding over fluvially-incised valleys resulting in backstepping of fluvial and estuarine siliciclastic facies within the erosionally confined zone of an incised valley. However, the pre-salt systems of the …

Studies Of Air Pollutants And Their Impact On Respiratory And Cardiovascular Diseases In The El Paso Del Norte Region With Emphasis On Mobile Emissions, Juan Gustavo Arias Ugarte

Open Access Theses & Dissertations

Air pollution may cause different diseases, such as cardiovascular and lung diseases. Traffic is a major source of mobile emissions causing air pollution. Exhaust emissions from mobile sources (Emissions of Carbon Monoxide, Nitrogen Oxides and Hydrocarbons) and Non-exhaust (Brake and Tire) are complex mixtures of gases and dust, including a large number of ultrafine particles, especially in areas with high traffic density. Recent studies have shown high rates of morbidity and mortality in people exposed to these types of emissions because the fine and ultrafine particles can be transported from the respiratory airways to the organs, thus contributing to increase …

Estimating The Coefficients Of A Linear Differential Operator, Maria Ivette Barraza

Open Access Theses & Dissertations

Principal Differential Analysis (PDA; Ramsay, 1996) is used to obtain low dimensional representations of functional data, where each observation is represented as a curve. PDA seeks to identify a Linear Differential Operator (LDO) L = ω0I + ω 1D + ... + ωmDm, where I denotes the identity function and D j the jth derivative, that satisfies as closely as possible that Lx = 0 for each functional observation x. A theorem from analysis establishes that the coefficients of the LDO are in the Sobolev space, and thus can be approximated by B-splines. Current PDA software used to estimate the …

Electronic Structure Studies On Transition Metal Containing Endohedral Fullerenes, Carbon Onions And Zinc Sulfide Cages, Shusil Bhusal

Open Access Theses & Dissertations

We present the most stable structures for VXSc3-XN@C2n (where X=1-3 and 2n=70, 76, 78 and 80) using a systematic procedure that involves all possible isomers of the host fullerene cages. Subsequently, a detailed investigation of structural and electronic properties of the lowest energy isomers is performed using density functional theory in combination with large polarized Gaussian basis sets. The search procedure developed involved structural optimizations of thousands of fullerenes and correctly identifies the experimentally observed VSc2N@C80 and V2ScN@C80 isomer as the most stable structures. The structural analysis shows that a few V-doped endohedral fullerenes do not follow the isolated pentagon …

Investigation On A Cooling Channel Design For A High Heat Flux Oxy-Fuel Direct Power Extraction Combustor, Luisa Alejandra Cabrera Maynez

Open Access Theses & Dissertations

The implementation of oxy-fuel technology in fossil-fuel power generation could result in a drastic increase of system efficiencies and a reduction of emissions. While typical system temperatures are dictated by material constraints, open-cycle magnetohydrodynamic (MHD) power generators have the potential to utilize the energy of undiluted flames. This work presents design and modeling strategies to develop steady-state supersonic MHD combustors operating at temperatures exceeding 3000 K. Throughout the study, computational fluid dynamics (CFD) models were extensively used as a design and optimization tool. A proof-of-concept 60 kWth model was designed, manufactured and tested in accordance to methods relevant to rocket …

Utilizing Historical Mosquito Surveillance Data To Investigate The Efficacy Of Municipal Fogging In Controlling Mosquito Population Density, Andrea Betina Carzoli

Open Access Theses & Dissertations

Background: Mosquito borne diseases are the cause of many different disease syndromes and deaths in animals, both wild and domesticated, and humans of all ages and ethnicities. Though El Paso, TX is located in an arid region, mosquito populations are still rapidly growing in urban and agricultural communities and so are the mosquito borne illnesses. The most common vectors associated with mosquito borne illnesses in El Paso County are Culex quinquefasciatus, Culex tarsalis, and Aedes aegypti. Vector management is often the primary option to prevent and control outbreaks of mosquito borne illnesses and very often utilize fogging as the primary …

Synthesis Of New Fullerene Derivatives For Photovoltaic And Biological Applications, Edison Castro

Open Access Theses & Dissertations

Functionalized fullerenes exhibit improved solubility and different chemical and physical properties that allow applications in multiple fields such as photovoltaic and biological applications. Currently, perovskite solar cells (PSCs) are the most rapidly developing type of solar cells with certified efficiencies rising from 3.8% in 2009 to 22.1% in 2016. The good electron transporting and solution processable properties of most fullerene derivatives make them the most popular electron transporting materials (ETMs) in inverted perovskite solar cells (PSCs).

The work is reported in 11 chapters. We start with a fullerene overview followed by cleaver and elegant methodologies that allow the synThesis of …

Development Of Post-Pareto Optimality Methods For Multiple Objective Optimization, Juan Valentin Fernandez

Open Access Theses & Dissertations

In the past years, multiple objective optimization has been considered, as an important research area since in many real life problems there exists multiple criteria that need to be optimized simultaneously. The use of evolutionary algorithms or metaheuristic methods as solution methodologies lead to a large number of Pareto solutions rather than a single unique optimum. This Pareto-optimal set most of the time tends to be very large and the decision maker now faces the challenge of reducing its size to analyze a feasible number of solutions, thus deciding the best possible solution. In this work, two methods will be …

A Novel Approach To Enhancing Upper Extremity Coordination In Children With Autism Spectrum Disorder, Alejandra Sarahi Gamez Corral

Open Access Theses & Dissertations

With current estimates of 1 in 68 children being affected, Autism Spectrum Disorder (ASD) is regarded as one of the most rampant forms of disability globally. Although typically diagnosed through social impairment and repetitive stereotypical behavior, recent work has shown distinct motor impairments across the autism spectrum. These motor deficits can be gross or fine in nature and can be seen not only in reaching and grasping, but also in the kinematic composition of the actual movement, such as decreased velocity, decreased accuracy, irregular movement smoothness, etc. The goal of this study was to further the understanding of the kinematic …

Tracing Anthropogenic Salinity Inputs To The Semi-Arid Rio Grande River: A Multi-Isotope Tracer Approach, Sandra Garcia

Open Access Theses & Dissertations

Water is an important component for life and as such water quality and availability are major concerns in the world today. In arid to semi-arid regions, freshwater quality is especially important due to its scarcity. Elevated salinity of rivers in arid regions poses potentially devastating consequences for the communities that depend on these rivers as a source of freshwater. In the Rio Grande region, high salinity has led to severe reductions in crop productivity and accumulation of salts in soils. Salinity inputs into the river may come from both anthropogenic and natural sources. Thus, identifying and quantifying salinity inputs to …

Investigation Of Earthquake And Geyser Activity From Short-Term Nodal Array Deployment Centered At Old Faithful Geyser, Susana I. Garcia

Open Access Theses & Dissertations

Yellowstone National Park is home to an active caldera, centrally located on the North American continent. Several studies have concluded the existence of a hotspot that fuels the hydrothermal, geothermal and earthquake activity in the Yellowstone region. The geologic record of Yellowstone contains multiple layers of volcanic deposits that indicate the region experienced three previous massive volcanic eruptions dating back 2.05Mya, 1.2Mya and the most recent 640,000 years ago. Yellowstone is also home to one of the largest geothermal areas in the world. With this study, an in-depth look at seismicity and geyser events recorded within an active geothermal region, …

Analysis Of Bias-Corrected And Exact Estimators For Binomial Generalized Linear Model Parameters, Hamna Hannan

Open Access Theses & Dissertations

Typically, small samples have always been a problem for binomial generalized linear models. Though generalized linear models are widely popular in public health, social sciences etc. In small sample scenarios the non-existence of the maximum likelihood (ML) estimators is very common as well as separation occurs in the data. In logistic regression the maximum likelihood estimates are found to have biased away from origin. My work examines the bias-reduced and exact estimators that have been used to estimate the slope parameters and standard errors of the estimated slope parameters as compared to the traditional ML method.

The present work is …

Quantifying The Characteristic Length Of A Combustor For An Ionic Liquid Monopropellant Thruster, Kimberly Marie Hogge

Open Access Theses & Dissertations

Ionic liquid monopropellants are currently being researched as a promising alternative to hydrazine in propulsion systems. This report presents a flame study that delineates the flame length of the expected decomposition products from an ionic liquid monopropellant. Through these studies, the characteristic length of a combustion chamber will be defined through calculations and empirical correlations. There is limited information on designing a propulsion system for an ionic liquid monopropellant. Therefore, defining the magnitude for an effective characteristic length serves as beneficial in designing a propulsion system for an ionic liquid monopropellant thruster.

Ac Susceptibility And Epr Investigations Of Superspin Dynamics In Manganese Oxide Nanoparticles, Mahesh Koirala

Open Access Theses & Dissertations

We have investigated the superspin dynamics of 5 nm and 10 nm mixed state Mn3O4 nanoparticles utilizing ac-susceptibility and electron paramagnetic resonance measurements. The out of phase component of the ac-susceptibility measurements show a magnetic anomaly below (T

Contextual Representation Of Documents, Entities, And Faces Of People Using A News Corpus, Md Abdul Kader

Open Access Theses & Dissertations

A massive amount of unstructured data, in this information age, is composed of document collections. Examples include news articles, blog posts, scholarly publications, and reports generated by organizations as well as people. Many data mining and machine learning algorithms have been developed in the past decade to support text mining in many applications. Text mining applications cover a wide range of tasks spanning from personal information management --- to organizational decision making, to disease control through epidemic prediction, and to intelligence analysis for national security. One bottleneck has been dominating data mining and machine learning theories for all these text …

The Nonparametric Estimation Of Elliptical Distributions, Panfeng Liang

Open Access Theses & Dissertations

In practice, many multivariate datasets have identical marginal distributions. Elliptical distributions can be used to model many of those datasets. In this Thesis, we will propose a Bayesian method using Markov chain Monte Carlo (MCMC) methods to estimate the density function underlying multivariate datasets assuming it is an elliptical distribution.

Gypsum, Calcite, And Dolomite Caprock Fabrics And Geochemistry From The Gypsum Valley Salt Diapir, Paradox Basin, Southwestern Colorado, Kevin Lerer

Open Access Theses & Dissertations

Caprocks are found on top of or in a lateral position relative to salt diapirs. The caprocks predominantly comprise sulfate minerals such as anhydrite or gypsum, which presumably accreted during the dissolution of salt from evaporite sediments. In some cases, the sulfate minerals are replaced by carbonate minerals, referred to as "carbonate caprock". Carbonate caprocks associated with salt diapirs are important because they can act as reservoirs or conduits for hydrocarbons, and because they can be easily misidentified as carbonate lithologies belonging to the stratigraphy of the sedimentary sequences adjacent to the diapir, which can jeopardize the accurate interpretation of …

Jury Simulation Goals, Jonathan J. Koehler, John B. Meixner Jr.

Scholarly Works

What are the goals that researchers who conduct jury simulations have or should have? Drawing on Pennington and Hastie (1981), we identify three primary goals: (1) develop theory, (2) describe how juries perform, and (3) improve the jury process. Where basic theory matters most, studies should be designed in ways that stress internal validity. Where describing the behaviors of real juries or persuading policy makers about changes that should be made, studies should focus on external and ecological validity as well. We urge researchers who are interested in describing jury behavior and improving the jury process to conduct ecologically valid …

Proportionality Lost? The Rise Of Enforcement-Based Equity In The Deportation System And Its Limitations, Jason A. Cade

Scholarly Works

This article briefly explains and critiques the legal framework that has made enforcement discretion the primary means of injecting proportionality and fairness into the modern deportation system. The article provides an overview of shifting approaches to this enforcement discretion under the Obama and Trump administrations, and describes some of the key Supreme Court jurisprudence interpreting this framework.

Which Supreme Court Cases Influenced Recent Supreme Court Ip Decisions? A Citation Study, Joseph S. Miller

Scholarly Works

The U.S. Supreme Court has decided an increasing number of intellectual property cases — especially patent cases — over the last several terms. Which prior cases influence the stated reasoning in these recent Supreme Court IP cases? A handful of citation studies of supreme courts in the U.S., both state and federal, conducted over the last 40 years suggest that the Court would most often cite its own prior cases; that it would cite its more recent cases more often than its older cases; and that a small number of its prior cases would receive a large share of the …

Lamps, Maps, Mud-Machines, And Signal Flags: Science, Technology, And Commerce In The Early United States, James Russell Risk

Theses and Dissertations

As the United States looked forward to its future as an independent nation at the end of the eighteenth century, many saw commerce as a way to secure the nation’s future. American commerce, however, was plagued by a number of commercial problems. Solving these commercial problems facilitated an interest in science and the practical arts as engineers, inventors, mechanics, public officials, and everyday tinkerers innovated new apparatuses to preserve, promote, and protect American commerce. Many of America’s commercial problems in the early nineteenth century, however, resulted from the young nation’s varied geography and environments. Combating the environment’s unrelenting forces often …

In Your Experience: Pathways And Barriers For Female Students Of Stem, Elizabeth J. Hartnett

Theses and Dissertations

This study addresses the gender gap that exists in the STEM professions. The number of jobs in STEM is climbing rapidly, but participation by women is disproportionately low. Although they make up roughly half of the overall population, women account for only about one quarter of the STEM workforce. A similar gap exists among undergraduates majoring in STEM fields. This is an exploratory study intended to identify and explore factors contributing to this gender gap, as perceived by undergraduate students. Through an online survey and follow-up interviews of undergraduates at two universities in the southeastern United States, data were collected …

Sanitary Sewer Overflows In Columbia, South Carolina And Their Impact On Mercury And Metal Cycling, Alison Emmons

Theses and Dissertations

Objectives. Microbial pathogens and their threat to human health have been the primary concern of sanitary sewer overflows (SSO); however, SSOs may also be a source of metals, including methylmercury, to local waterways. We hypothesized that SSOs had elevated concentrations of metals compared to nearby reference creeks.

Methods. Unfiltered and filtered (0.2 μm) surface water samples were collected monthly between November 2015 and March 2016 from three sewage-impacted creeks in Columbia, South Carolina. During this period, three sewage events were captured including an active SSO, a ruptured force main sewer pipe, and one site downstream from SSOs. In October 2016 …

Development And Testing Of Cool-Season Grass Species, Varieties And Hybrids For Biomass Feedstock Production In Western North America, Steven R. Larson, Calvin H. Pearson, Kevin B. Jensen, Thomas A. Jones, Ivan W. Mott, Matthew Darwin Robbins, Jack E. Staub, Blair L. Waldron

Plants, Soils, and Climate Faculty Publications

Breeding of native cool-season grasses has the potential to improve forage production and expand the range of bioenergy feedstocks throughout western North America. Basin wildrye (Leymus cinereus) and creeping wildrye (Leymus triticoides) rank among the tallest and most rhizomatous grasses of this region, respectively. The objectives of this study were to develop interspecific creeping wildrye (CWR) × basin wildrye (BWR) hybrids and evaluate their biomass yield relative to tetraploid ‘Trailhead’, octoploid ‘Magnar’ and interploidy-hybrid ‘Continental’ BWR cultivars in comparison with other perennial grasses across diverse single-harvest dryland range sites and a two-harvest irrigated production system. Two …

Gridded Snow Water Equivalent Reconstruction For Utah Using Forest Inventory And Analysis Tree-Ring Data, Daniel Barandiaran, Shih-Yu (Simon) Wang, R. Justin Derose

Plants, Soils, and Climate Faculty Publications

Snowpack observations in the Intermountain West are sparse and short, making them difficult for use in depicting past variability and extremes. This study presents a reconstruction of April 1 snow water equivalent (SWE) for the period of 1850–1989 using increment cores collected by the U.S. Forest Service, Interior West Forest Inventory and Analysis program (FIA). In the state of Utah, SWE was reconstructed for 38 snow course locations using a combination of standardized tree-ring indices derived from both FIA increment cores and publicly available tree-ring chronologies. These individual reconstructions were then interpolated to a 4-km grid using an objective analysis …