Physical Sciences and Mathematics Commons^™

Paradox Diapir Inclusions As A Window Into Diapiric Processes In Proximity To The Uncompahgre Uplift And The Early History Of The Paradox Basin, Utah And Colorado, Madison Clare Woelfel

Open Access Theses & Dissertations

Layered evaporite sequences, cyclic, kilometer-thick deposits of salt, are among the most unusual and fascinating lithologies that geologists encounter. There is no recent analogue to their formation, and their ability to flow when subject to differential pressure makes them unique. Salt structures serve as sources for halite, bittern salts, metals, and hydrocarbons and can be used for storage of materials, including hydrocarbons, carbon dioxide, hydrogen, and nuclear waste. Basins in which layered evaporite sequences are deposited receive detrital input sporadically from adjacent areas, depositing inclusions of non-evaporite lithologies that are entrained when salt flows. These inclusions are exposed in a …

Growth Of Purple Sulfur Bacteria Allochromatium Vinosum On Solid Phase Metal Sulfides As Sulfur And Electron Sources, Hugo Alarcon

Open Access Theses & Dissertations

Purple sulfur bacteria (PSB) are photosynthetic microorganisms known for their vital roles in geochemical cycles, especially the sulfur cycle, within anoxic photic environments. PSB are also key contributors to the nitrogen, carbon, and oxygen cycles. This study focuses on the autotrophic growth of Allochromatium vinosum, a model strain of PSB, that utilize solid-phase metal sulfides (MS) as both sulfur and electron donors. Through characterizing the growth profiles of A. vinosum on pyrite (FeS2), nickel sulfide (NiS), and iron monosulfide (FeS) nanoparticles, respectively, and investigating the bacteria-MS interaction mechanisms, this work expands our current knowledge of the metabolic capabilities and flexibility …

Design And Development Of Transition Metal-Based Electrocatalysts For Environmentally Friendly And Efficient Hydrogen Evolution Reactions (Her), Navid Attarzadeh

Open Access Theses & Dissertations

Hydrogen fuel is a clean energy source primarily because it emits no carbon dioxide (CO2). Sustainable energy alternatives have attracted the scientific community and policymakers as concerns over global warming and depletion of fossil fuels have increased significantly. Substituting H2 gas as a primary source for our daily energy consumption under the guideline of the hydrogen economy concept has not progressed as anticipated because of inadequate efficiency associated with the generation (electrolyzer) and utilization (fuel cell) devices. However, there are challenges associated with hydrogen that must be overcome for it to become a truly sustainable and widespread energy source. The …

Performance Evaluation Of A Coupled Photovoltaic-Thermal Solar Powered Desalination Pilot System, Martin Chavarin

Open Access Theses & Dissertations

A pilot scale coupled photovoltaic-thermal solar powered desalination system was evaluated at the Brackish Groundwater National Desalination Research Facility (BGNDRF). The pilot system consisted of a 3-kW photovoltaic-thermal (PVT) solar panel array and a 2.3 kW photovoltaic (PV) array coupled with a 4 gal/min single-stage 4 membrane reverse osmosis (RO) desalination system. A heat exchange system was in place to provide simultaneous cooling for the PVT system and heating to the RO system feed water. This system was evaluated with three objectives in mind. The first objective was to identify whether cooling of the PVT panels resulted in a significant …

Partial Auto-Correlation Of Low Magnitude Earthquakes From The 2016 Iris Aray In Grant County, Oklahoma, Alex Christopher Eddy

Open Access Theses & Dissertations

The Anadarko Basin in is a seismically active basin that spans central and western Oklahoma into Kansas. In June and July of 2016, the IRIS Community Wavefield Experiment array was deployed for approximately a month, recording over 300 earthquakes. Using 4 of these earthquakes and an east â?? west array of 129 Fairfield Nodal Z-land 3C nodes, I present a novel application of correlation. These four earthquakes with a ML of 2.8-3.0 represent a varied azimuthal distribution and are between 9 and 40km from the array and have a frequency peak at approximately 10 Hz.

As a proof of concept, …

Increasing The Efficiency And Accuracy Of Collective Intelligence Methods For Image Classification, Md Mahmudulla Hassan

Open Access Theses & Dissertations

Collective intelligence has emerged as a powerful methodology for annotating and classifying challenging data that pose difficulties for automated classifiers. It works by leveraging the concept of "wisdom of the crowds" which approximates a ground truth after aggregating experts' feedback and filtering out noise. However, challenges arise when certain applications, such as medical image classification, security threat detection, and financial fraud detection, demand accurate and reliable data annotation. The unreliability of experts due to inconsistent expertise and competencies, coupled with the associated cost and time-consuming judgment extraction, presents additional challenges.

Input aggregation is the process of consolidating and combining multiple …

The Ecological Effects Of Nitrogen Enrichment In Aridlands, Jennifer Holguin

Open Access Theses & Dissertations

Anthropogenic nitrogen (N) deposition is one of the most prominent factors driving global change. Across the globe, N deposition has driven major changes in terrestrial ecosystems, such as declines in plant biodiversity, enhanced exotic plant growth, and changes to biogeochemical processes involved in carbon and nutrient cycling. While noteworthy effort has been put forth to investigate the effects of N deposition on terrestrial ecosystems, a disproportionate number of N addition studies have been conducted in temperate mesic systems. Thus, we lack a holistic and mechanistic understanding of how N deposition impact aridland ecosystems. Additionally, our predictions of the effects of …

How Active Rainwater Harvesting May Help Reduce Nuisance Flooding: Flood Analysis And Social Barriers To Adoption, Isabel Lopez

Open Access Theses & Dissertations

As urbanization continues to expand, fewer pervious surfaces are available to help reduce stormwater runoff from rainfall. The impacts of urbanization are becoming evident through sunny day flooding - flooding that occurs in areas not designated by the Federal Emergency Management Agency (FEMA) as flood zones. Nevertheless, water accumulates in low-lying areas and compromises street intersections and other parts of neighborhoods. Some methods can help alleviate the impacts of unexpected heavy rains, such as passive and active rainwater harvesting. As a pilot study, in a selected area in the northeast of El Paso, the level of adoption (e.g., what percentage …

Robust Penalized Density Power Divergence Regression With Scad Penalty For High Dimensional Data Analysis, Maxwell Kwesi Mac-Ocloo

Open Access Theses & Dissertations

Amidst the exponential surge in big data, managing high-dimensional datasets across diverse fields and industries has emerged as a significant challenge. Conventional statistical methods struggle to handle their complexity, making analysis intricate. In response, we've formulated a robust estimator tailored to counter outliers and heavy-tailed errors. Our approach integrates the SCAD penalty into the Density Power Divergence method, effectively reducing insignificant coefficients to zero. This enhances analysis precision and result reliability.We benchmark our robust and penalized model against existing techniques like Huber, Tukey, LASSO, LAD, and LAD-LASSO. Employing both simulated and UCI machine learning repository datasets, we assess method performance …

Continuous Risk Assessment For Large-Scale Cyber Systems, Adeel A. Malik

Open Access Theses & Dissertations

Cyberspace, with its multiple forms of device integration, is rapidly evolving and introducing loopholes within the cyber infrastructure, which creates opportunities for attackers. Despite the presence of network security devices such as firewalls, anti-virus, intrusion detection, and prevention systems, network intrusions still occur due to vulnerabilities within organizational assets or socially engineered cyber attacks. The lack of information about threats, vulnerabilities, and threat actors often leaves cyber defenders on a wild goose chase, making it critical to evaluate network security to mitigate adversarial threats periodically.

Various risk assessment frameworks, third-party tools, and online databases containing comprehensive threat information have been …

A Dft Analysis And Simple Hamiltonian Modeling Of A Molecular System Employed For Experimental Evidence Of Quantum Teleportation, Pedro Ulises Medina Gonzalez

Open Access Theses & Dissertations

Radical ion pairs (RIPs) have been used to demonstrate quantum teleportation in molecular systems for applications in quantum information science. Covalent organic donor-acceptor (D-A) molecules can produce RIPs through photo-induced charge transfer and an additional radical (R) molecule makes quantum teleportation possible. We present the electronic structure and analyze charge transfer excited states of a recently studied [1] D-A-R molecular system using density functional theory. The distances between donor-acceptor and donor-radical are about 12.9 \AA $\,$ and 21.9 \AA, respectively. The excitation energies are calculated using the perturbative delta-SCF method and agree with other conventional excited-state methods and experimental reference …

Advances In One-Electron Self-Interaction-Correction Methods For Accurate And Efficient Self-Interaction-Free Density Functional Calculations, Selim Romero

Open Access Theses & Dissertations

Density functional theory (DFT) is a widely used computational method for studying electronic structures of atoms, molecules, and solids. It provides an exact theory for obtaining ground state energy from the ground state density. However, since the exact exchange-correlation functional remains unknown, approximate exchange-correlation functionals called approximate density approximations (DFAs) are used. The foundation of many DFAs is the local spin density approximation (LSDA). It serves as the starting point for constructing various DFAs. However, DFAs are prone to self-interaction errors (SIE) due to the improper cancellation of the approximate exchange energy and the Coulomb energy. This issue impacts the …

Robust Mahalanobis K-Means Algorithm In Comparison With Other Existing Clustering Methods., Eleazer Tabi Serebour

Open Access Theses & Dissertations

This study enhances K-means Mahalanobis clustering using Density Power Divergence (DPD) for outlier handling and detection. Through the utilization of simulations and the analysis of real-world data, our approach consistently outperforms standard K-means, Mahalanobis K-means, Fuzzy C-means, and others in clustering datasets with outliers. While our method performs similarly to others on spherical datasets, it ranks second to DBSCAN for arbitrary shapes. We showcase its superiority on real-life datasets (Iris flower and wheat seed), demonstrating resilient outlier identification. By navigating various structures and cluster characteristics, our Modified Mahalanobis K-means method proves adaptable and robust, offering insights into diverse clustering scenarios. …

Volatility Modeling Of Time Series Using Fractal And Self-Similarity Models, William Kubin

Open Access Theses & Dissertations

The study uses various methods to compare financial and geophysical time series scaling parameters and long-term memory behavior. The Cantor Detrended Fluctuation Analysis (CDFA) method is proposed to provide more accurate estimates of Hurst exponents. The CDFA method is applied to real-time series and the results are verified. The study also analyzes the memory behavior of daily Covid-19 cases before and after the announcement of effective vaccines. Low and high-frequency dataâ??s influence on the Hurst Index estimation is investigated, and a new PCDFA method is proposed. The stability of the Dow Jones Industrial Average is analyzed using a multi-scale normalized …

Nonparametric Estimation Of Elliptical Copulas, Panfeng Liang

Open Access Theses & Dissertations

Elliptical copulas provide flexibility in modeling the dependence structure of a random vector. They are often parameterized with a correlation matrix and a scalar function, called generator. The estimation of the generator can be challenging, because it is a functional parameter. In this dissertation, we provide a rigorous approach to estimating the generator in a Bayesian framework, which is simpler, more robust, and outperforms existing estimation methods in the literature. Based on the proposed framework in this dissertation, other researchers may modify the model for other types of generators in their own research.

Microscopic And Spectroscopic Analysis Of Nordihydroguaiaretic Acid Effect On Astrocytes, Lizbeth Vanessa Martinez Lopez

Open Access Theses & Dissertations

Astrocytes, one of the most abundant cell components in the central nervous system (CNS), have been a research target in the last few years. Several studies have found that astrocytes are not only mere supporters of neurons but also of essential processes developed in the CNS. Their malfunction could induce neurodegenerative diseases and brain tumors. Thus, further understanding of astrocytes and their role is of high interest to develop possible new treatments and methods of disease diagnosis, especially in brain cancer. The plant Larrea tridentata (La Gobernadora in Mexico or Creosote bush in the United States) is known to have …

On The Predictability Of Appropriate Prosody Of Dialog Markers Directly From The Local Context, Anindita Nath

Open Access Theses & Dissertations

Today's state-of-the-art spoken dialog systems lack context-appropriate prosody in their responses, often making them sound unnatural. Better modeling of this contextual dependency would enable natural prosodic responsiveness. Accordingly, this dissertation explores the extent to which the prosody of a dialog marker can be predicted directly from the prosody of its local context. The prediction performance was evaluated in terms of the similarity between the predicted and the observed prosodic features as measured by the reduction of root mean square error from the baseline. This prediction task was accomplished for multiple combinations of various sets of context features and different machine …

Developing A Risk Assessment Instrument For Immigration Cases Under Federal Supervision, Mayra Eydie Pacheco

Open Access Theses & Dissertations

No abstract provided.

Recursive Forms For Determinant Of K-Tridiagonal Toeplitz Matrices, Eugene Agyei-Kodie

Open Access Theses & Dissertations

Toeplitz matrices have garnered renewed interest in recent years due to their practical applications in engineering and computational sciences. Additionally, research has shown their connection to other matrices and their significance in matrix theory. For example, one study demonstrated that any matrix can be expressed as the product of Toeplitz matrices \citep{ye2016every}, while another showed that any square matrix is similar to a Toeplitz matrix \citep{mackey1999every}.

Numerous studies have examined various properties of Toeplitz matrices, including ideals of lower triangular Toeplitz matrices \citep{dogan9some}, matrix power computation with band Toeplitz structures \citep{dogan2017matrix}, and norms of Toeplitz matrices. Moreover, the use of …

Novel Pathways To Tailor Charge And Spin In Materials And Investigating The Impact On Sensing And Electrochemical Energy Applications, Aruna Narayanan Nair

Open Access Theses & Dissertations

Catalysis is integral to our daily lives, as it streamlines and accelerates numerous chemical reactions essential for producing various materials, fuels, and chemicals. With the rising demand for clean, sustainable energy sources, optimizing catalytic materials and processes becomes increasingly vital. In the realm of renewable energy production, catalysis is crucial for efficiently converting energy from sustainable resources, such as solar, wind, and biomass, into chemical energy stored in fuels or directly into electrical energy.The electronic charge distribution in materials significantly influences their physical and chemical properties, facilitating the development of advanced electronic, optoelectronic, sensing, and energy conversion devices. Since catalysis …

Differentiating Biotic Vs. Abiotic Co2 In The Formation Of Pedogenic Carbonate In Agriculture And Natural Dryland Soils, Valeria Isabel Molina

Open Access Theses & Dissertations

Drylands, characterized by low and sporadic precipitation, require irrigation for crop growth. However, irrigation practices can lead to salt accumulation in soil due to high evaporation rates and reduced leaching. In addition to loading salts to soil, irrigation promotes the accumulation of secondary calcite. In natural systems, the formation of pedogenic carbonate (secondary calcite, CaCO3) is critical, impacting the soil properties hydrologically and biogeochemically, and modifying the global carbon cycle over geological time, albeit at a lower rate. In agricultural sites, irrigation water supplies HCO3- and Ca2+, accelerating the rates of CaCO3 formation and releasing abiotic CO2. This study investigated …

Field Observations And Stable Isotope Analysis Of Alunite At The Sulphur Bank Mercury Mine, Clear Lake, California, David Edward Muller

Open Access Theses & Dissertations

The Sulphur Bank mercury mine is a historic mine located in Lake County, California, first exploited in the 1860s. Underground mining of mercury took place from 1873 to 1906 and open-pit mining of mercury was done from 1927 to 1957. The U.S. Environmental Protection Agency listed the Sulphur Bank mine and the adjacent Clear Lake as a Superfund site in 1990 due to mercury contamination at the mine site and in the sediment and food web of Clear Lake. Previous studies have described the vein material mineralogy and wall-rock alteration at Sulphur Bank as well as the composition of water …

Incorporating Community Science In Improving Environmental Data Quality Through Model Based Reasoning Techniques, John Gilbert Olgin

Open Access Theses & Dissertations

This dissertation will address the questions: In what ways can MBR theory be applied to designtraining that will improve the capacity of Citizen scientists to collect and analyze high quality scientific data? To what degree does this training impact their ability to formulate complex understandings of environmental problems in their Citizen? The project will be comprised of three research objectives focused in three sections, carried out with NASAâ??s GLOBE Observer Citizen Science Program:

Section 1: An analysis of existing GLOBE data will be conducted, identifying whereerrors in data collection originate. At least three principal errors will be selected from this …

Addressing The Challenged Of Dcop Based Decision-Making Algorithms In Modern Power Systems, Luis Daniel Ramirez Burgueno

Open Access Theses & Dissertations

Natural disasters have been determined as the leading cause of power outages, causing not only huge economic losses, but also the interruption of crucial welfare activities and the arise of security concerns. Because of the later, decision-making considering grid modernization, power system economics, and system resiliency has been a crucial theme in power systemsâ?? research. The need to better withstand catastrophic events and reducing the dependency of bulky generating units has propelled the development and better management of behind-the-meter generation or distributed energy resources (DERs). DERs can assist in the grid in different manners, not only by meeting energy demand …

Developing And Applying Computational Methods On Biomolecules, Shengjie Sun

Open Access Theses & Dissertations

Computational biophysics is an interdisciplinary subject that uses numerical algorithms to study the physical principles underlying biological phenomena and processes. Electrostatic interactions play an important role in computational molecular biophysics and their potential impact on disease mechanisms. At distances larger than several Angstroms, electrostatic interactions dominate all other forces, while the alteration of short-range electrostatic pairwise interactions can also have significant effects. The dual nature of electrostatic interactions, being dominant at long-range and specific at short-range, underscores their profound implications for wild-type structure and function. Any disruption of the complex electrostatic network of interactions may abolish wild-type functionality and could …

Seismicity, Tectonics, And Site Response In The Nepalese Himalayas, Mohan Pant

Open Access Theses & Dissertations

The continental collision between the Indian plate and the Eurasian plate at ~55 Ma (Molnar and Tapponnier, 1975) has uplifted the northern part of Nepal forming the Himalayas. This convergence of India and Eurasia produced intra-upper crustal shear zones and thickened the crust to its present thickness of 70 km (Molnar, 1988; Zhao et al, 1993). The convergence rate across the Nepalese Himalayas is estimated between 17-21 mm/yr. (Ader et al., 2012). Because of this convergence, the region has experienced large, devastating earthquakes, including the 1934 Mw~8.2 Nepal-Bihar earthquake (Dunn et al., 1939) and two recent earthquakes on April 25, …

Flexible Models For The Estimation Of Treatment Effect, Habeeb Abolaji Bashir

Open Access Theses & Dissertations

Estimation of treatment effect is an important problem which is well studied in the literature. While the regression models are one of the most commonly used techniques for the estimation of treatment effect, they are prone to model misspecification. To minimize the model misspecification bias, flexible nonparametric models are introduced for the estimation. Continuing this line of research, we propose two flexible nonparametric models that allow the treatment effect to vary across different levels of covariates. We provide estimation algorithms for both these models. Using simulations and data analysis, we illustrate the usefulness of the proposed methods.

Multi-Objective Optimization Framework For Electrified Vehicle Penetration Based On Life Cycle Assessment And Life Cycle Cost., Eva Alondra Diaz Lozano

Open Access Theses & Dissertations

This research proposed a novel framework for creating optimal transportation scenarios that consider multiple objectives such as minimum greenhouse gas emissions, air pollutant levels, and cost of ownership. The thesis approach is a multi-objective evolutionary algorithm coupled with the AFEET tool, allowing us to efficiently explore the complex trade-offs between these objectives and identify a diverse set of optimal solutions. Through several case studies and a design of experiments, this demonstrates the effectiveness and practicality in different scenarios. This approach has significant implications for policymakers and industry professionals seeking to make sustainable and cost-effective decisions in the transportation sector.

Generalized Additive Model Using Marginal Integration Estimation Techniques With Interactions, Tahiru Mahama

Open Access Theses & Dissertations

Marginal Integration (MI) is a statistical method that is extensively employed to estimatecomponent functions of the nonparametric additive models. The shortcoming of the purely additive model is that interaction between predictor variables is often ignored, and it may produce poor performance in some real applications. As a result, this research considers the second-order interactions in the regression models. The primary objective is to use marginal integration techniques to estimate the nonparametric additive functions. We compare this model with other models/estimators such as the Generalized Additive Model (GAM), Generalized Additive Model with Selection (GAMSEL), Robust Marginal Integration (RMI), Ordinary Least Squares …

Linking Decomposition Reactions In Arctic Soils To Microbial Enzyme Production, Jane Karen Martinez

Open Access Theses & Dissertations

Microbial processes such as soil enzyme production are a major driver of decomposition and a current topic of interest in arctic soils due to the effects of climate warming. Despite the advances in understanding soil enzymes, there are still knowledge gaps regarding the role of enzymes in decomposition. In this dissertation, I addressed three of those gaps in the following chapters: (Ch.2) to explore the location of enzymes within the soil matrix, (Ch.3) to identify peptides matched to soil enzymes produced by microorganisms for organic matter decomposition, and (Ch.4) understand the longevity of enzymes in the soil after microbial production. …