Physical Sciences and Mathematics Commons^™

Investigating The Roles Of Plants, Fungi, And Biocrusts In Nutrient Movement Within Dryland Ecosystems, Catherine E. Cort

Open Access Theses & Dissertations

In dryland ecosystems, plant productivity and microbial decomposition are often separated in space and time due to the asynchronous availability of soil moisture and organic matter inputs. It has been proposed that fungi play a key functional role in connecting these cycles by facilitating movement of water, carbon (C), and nitrogen (N) through a network of shared hyphae between plant roots and biological soil crust (biocrust) communities at the soil surface. This connection, also known as the â??fungal loop,â?? effectively re-couples processes of nutrient release and uptake between primary producers and minimizes ecosystem N losses due to leaching, erosion, and …

Effect Of Self-Interaction Correction On Molecular Polarizabilities And Core Ionization Energies, Sharmin Akter

Open Access Theses & Dissertations

Density Functional Theory (DFT) is one of the most successful and popular computational Quantum Mechanical approaches to understanding 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 to the spurious self-interaction error (SIE). Due to this error, the potential shows incorrect behavior which leads to errors in calculated properties such as ionization energies, electron affinities, polarizabilities, …

Activity Patterns Of Whiptail Lizards (Aspidoscelis) Found In The Northern Chihuahuan Desert, Guillermo Alvarez

Open Access Theses & Dissertations

Traditional lizard pitfall traps were modified to allow organisms to escape, while collecting valuable ecological data. Modified camera traps were capable of detecting the same species as traditional traps in a semi-arid environment, without posing the associated mortality risks. Pitfall-camera traps were used to sample the activity of the Side-blotched Lizard (Uta stansburiana) and the Southwestern Fence Lizard (Sceloporus cowlesi) in an urban wetland during four continuous years. Evaluations on activity pattern and the activity overlap between the two species revealed extensive overlap, with minor but significant seasonal shifts mediating coexistence. Traps were also effective at detecting other reptiles, invertebrates, …

Addressing Binational Issues For Water Quality Along The United States-Mexico Border And The Use Of The 1944 Water Treaty As A Means For Developing Transboundary Aquifer Agreements, Gilbert Anaya

Open Access Theses & Dissertations

The water resources of the United States (U.S.) and Mexico are under tremendous pressure due to declining reservoir levels, changes in climate, and prolonged drought. The U.S.-Mexico border region relies on the Rio Grande and Colorado River, and shared groundwater resources that are transboundary in nature. These resources are vital to the U.S.-Mexico border and are susceptible to drought that leads to reduced flow and allocation to the users. In addition, there are impacts to water quality caused by return flows and from failing sanitation infrastructure. In this study, we focus on 1) the contribution of springs in an area …

Towards A Model Of The Mapping Between English And Spanish Prosody, Jonathan Avila

Open Access Theses & Dissertations

Current speech-to-speech translation systems face challenges in effectively translating the nuances of prosody, which plays a pivotal role in conveying speaker intent and stance in dialog. This limitation restricts cross-lingual communication, especially in situations demanding deeper interpersonal understanding. To address this, this research delves into the relationships between prosody and its pragmatic functions, in English and Spanish. First, I discuss a data collection protocol in which bilingual speakers re-enact utterances from an earlier conversation in their other language, then describe an English-Spanish corpus, consisting of 3816 matched utterance pairs. Second, I describe a prosodic dissimilarity metric based on Euclidean distance …

Upcyclying Of Polyethylene Terephtalate By Addition Of Thermoplastic Elastomer, Diego Francisco Bermudez

Open Access Theses & Dissertations

Continual overconsumption of single-use plastics has generated challenges of solid waste management across the United States. Common plastic waste management solutions, such as landfill, have caused the migration of contaminants into the environment consequently affecting not only the health of wildlife, but also that of human beings. Alternative strategies for the handling of single-use plastic such as polyethylene terephthalate (PET), used in the food packaging industry, can ultimately help mitigate the noxious consequences of single-use plastics affecting entire ecosystems. This study demonstrates a potential avenue of materials upcycling by studying the effects of coupling PET with the thermoplastic elastomer styrene-ethylene-butylene-styrene …

Evaluation Of Evapotranspiration Estimates Using An Existing Hybrid Machine Learning Model In A Natural And A Managed Dryland Site, Katya Esquivel Herrera

Open Access Theses & Dissertations

Evapotranspiration (ET) is a critical component of the hydrologic cycle, encompassing both evaporative water loss from surfaces and transpiration through plant stomata. The environmental factors influencing ET include water and energy availability, atmospheric capacity for water uptake, and various meteorological variables. ET serves as a unique climate variable linking water, energy, and carbon cycles. In agroecosystems, accurate ET quantification is vital for optimizing water use efficiency, irrigation management, and crop yield. Traditional methods for ET estimation involve direct measurements and indirect models, with both presenting limitations.

Recent years have witnessed the integration of remote sensing and machine learning (ML) algorithms …

Context-Aware Temporal Embeddings For Text And Video Data, Ahnaf Farhan

Open Access Theses & Dissertations

Recent years have seen an exponential increase in unstructured data, primarily in the form of text, images, and videos. Extracting useful features and trends from large-scale unstructured datasets -- such as news outlets, scientific papers, and videos like security cameras or body cam recordings -- is faced with substantial challenges of volume, scalability, complexity, and semantic understanding. In analyzing trends, comprehending the temporal context is vital for uncovering patterns and narratives that are not apparent from a single video frame or text document. Despite its importance, many existing data mining and machine learning approaches overlook extracting evolutionary contextual features in …

Investigating Seismicity And Structure Of The Pecos, Texas Region Of The Delaware Basin Using A Temporary Nodal Network, Jenna Lynn Faith

Open Access Theses & Dissertations

With increasing earthquakes in the Delaware Basin since 2009, earthquake studies, including accurate hypocenters, are critically needed in the Delaware Basin to identify the structures producing earthquakes, and to determine if they are related to unconventional petroleum development and production. In 2018, with funding from the Texas Seismological Network (TexNet), the University of Texas at El Paso deployed and maintained a nodal network of 25 Magseis Fairfield Z-Land Generation 2 5-Hz seismic nodes in the Pecos, Texas region of the Delaware Basin, known as The Pecos Array. The network was deployed from November 2018 until the beginning of January 2020, …

A Noninvasive Urine-Based Method For Kidney Cancer Early Detection, Kiana Holbrook

Open Access Theses & Dissertations

Based on the traditional serological uses to obtain diagnoses of cancer and biopsy techniques, common cancer detection could be not only invasive but expensive and some tests are also unreliable. Currently, urine is one of the most frequently used and collected specimens in the clinical diagnoses. While the areas of urinalysis and metabolomic profiling has received interest in the top clinical research, there are limited components to the validity, specificity, as well as sensitivity of endogenous urine substrates to detect early stages of cancers. Although there is research showcasing that urine is impacted by age, cancer type, geographical location, and …

Computation-Assisted Molecular Discovery For Biomedical Applications: Seeking Small Molecules And Dna Sequences With High Affinity Target Binding, Payam Kelich

Open Access Theses & Dissertations

Binding affinity between two molecules is an essential property in drug and sensor discovery. Several computational and experimental methods exist to find molecules with high binding affinities to desired target molecules. These methods are often complementary, where fast computational methods can be used for the initial screening of molecules, and experimental methods can then screen and determine the molecules of interest and sometimes define the structures of bound complexes. After these steps, computational methods, like molecular dynamics (MD) simulations, can provide detailed insights into atomic interactions and binding, and machine learning approaches can analyze experiment-derived data to discern patterns and …

Southern Rio Grande Rift Kinematics And Geochronology, Big Bend Fold Geometry, And The Use Of Real Data In Geoscience Education: Contributions To The Understanding Of Big Bend Geology And To Public Geoscientific Literacy, Jessica Kelsch

Open Access Theses & Dissertations

The Big Bend region of Trans-Pecos Texas preserves a rich record of Rio Grande rifting and Laramide-age contraction that provide intrigue to national and state park visitors and field trips for undergraduate geology students. Despite its well-exposed geologic record, the Big Bend region remains an underutilized natural laboratory for studying these two tectonic events. This dissertation combines structural studies of Rio Grande rift and Laramide structures with public outreach and geoscience education studies focused on the Big Bend region. In Chapter 2, existing extensional-kinematic studies from parts of this region are compiled with new fault kinematic and U-Pb geochronologic data …

Leveraging Agile Software Methodologies Within Software Development To Introduce A Novel Educational Software Methodology, Montserrat Guadalupe Molina

Open Access Theses & Dissertations

Agile Software Development has been growing increasingly popular in the software engineering industry as a way to produce working software in a quick and people-centered manner. Agile methodologies require practitioners to have strong technical and non-technical skills, such as teamwork, project management, and communication skills. Students graduating from the software engineering discipline have been found to be lacking in these areas, leading to many difficulties faced by recent graduates as they begin their professional careers. Given that Agile Software Development is the most popular software development lifecycle currently used by practitioners in industry, it is important to expose students to …

Sterically Encumbering Ligands For The Synthesis And Stabilization Of Iron Nitride And Iron Oxo Compounds, Asiel Mena

Open Access Theses & Dissertations

The study of iron-nitrides has been found to be very attractive due to their potential role in processes like Haber-Bosch and nitrogen fixation by nitrogenase. The role of iron-nitrides in these processes is yet not well understood, and the fact that only handful of terminal iron-nitrides have been isolated or spectroscopically detected motivates us to study this type of systems, since much remains to be learned about the electronic and structural factors that affect the chemistry of the Feâ?¡N bond. Recently in our group, by using a super-bulky guanidinate ligand (LAr*), the obtention of an iron-nitride ([LAr*]FeN(py) (LAr* = (Ar*N)2C(NCtBu2), …

Enhancing Our Understanding Of Ancient Oceans Through The Investigation Of Molybdenum Behavior Under Sulfidic Conditions, Rachel Faye Phillips

Open Access Theses & Dissertations

The most abundant trace metal in the ocean today, molybdenum (Mo), exhibits distinct behavior in oxygenated water, where it remains predominantly dissolved, compared to euxinic (i.e., oxygen-free and sulfidic) water, in which it is sequestered into the sediment. This dissimilar behavior allows us to use Mo concentrations and isotopic compositions in sediment to reconstruct marine oxygenation conditions throughout geologic history. However, Mo sequestration mechanisms under euxinic conditions remain unresolved, which limits the accuracy and precision of reconstructions made using Mo signatures in the rock record. For my doctoral research, I experimentally investigated abiotic and biotic Mo sequestration mechanisms under various …

Bitcoin's Technical Foundation And Its Potential For A Decentralized And Environmentally Friendly Future, Iqtiar Md Siddique

Open Access Theses & Dissertations

This research examines a systematic analysis of Bitcoin, employing a Coefficient of Variation (CV) approach to gauge its degree of decentralization. Bitcoin, an innovative decentralized digital currency, has received much attention for its potential to revolutionize traditional financial systems. This study employs the Coefficient of Variation (CV) to acquire insights into the wealth distribution and concentration among Bitcoin users. This research demonstrates how decentralized the network of Bitcoin is. The methodology uses real data on Bitcoin addresses and their holdings to compute the Coefficient of Variation (CV). This approach provides valuable insights into the ongoing discourse surrounding Bitcoin's decentralization, offering …

Green Analytical Methods For The Determination Of Perfluorocarboxylic Acids (Pfcas) And Fluorotelomer Alcohols (Ftohs) In Water, Ahsan Habib

Open Access Theses & Dissertations

Per- and polyfluoroalkyl substances (PFAS) are a large group of synthetic organic compounds manufactured for their heat, water, and stain-resistant properties. PFAS can be found ubiquitously in the environment because they are widely used in everyday consumer products such as fast-food wrappers, non-stick cookware, stain-resistant products, cosmetics, aqueous film-forming foams, etc. As a result, PFAS are commonly detected in surface water, wastewater, and biosolids from wastewater treatment plants (WWTPs). These are the direct sources of PFAS contamination in drinking water supplies, which are substantial sources of human exposure. Among these PFAS chemicals, two major groups are perfluoroalkyl carboxylic acids (PFCAs) …

Co2-Dependent Nanoscale Organization In Bulk And Interfacial Carbon Dioxide Capture Liquids Elucidated Using X-Ray Scattering, Daniel Eduardo Moran

Open Access Theses & Dissertations

The pressing need to control carbon dioxide emissions has propelled extensive research efforts employing a variety of approaches across the globe. In flue-gas recovery of CO2, the water-lean amine-based solvent N-(2-ethoxyethyl)-3-morpholinopropan-1-amine (2-EEMPA), has shown exceptional performance. Recent studies show that 2-EEMPA exhibits intermediate-range order (IRO), beyond the first nearest neighbor length scale, consisting of tetrameric clusters. In view of the need to find solutions for direct air capture (DAC) of CO2, this system may represent a critical linkage in a DAC strategy, yet structural insights on EEMPA's behavior at solid surfaces are still lacking. To this end, we applied the …

Integrating Machine Learning Methods For Medical Diagnosis, Jazmin Quezada

Open Access Theses & Dissertations

Abstract:The rapid advancement of machine learning techniques has revolutionized the field of medical diagnosis by offering powerful tools to analyze complex data sets and make accurate predictions. In this proposed method, we present a novel approach that integrates machine learning and optimization models to enhance the accuracy of medical diagnoses. Our method focuses on fine-tuning and optimizing the parameters of machine learning algorithms commonly used in medical diagnosis, such as logistic regression, support vector machines, and neural networks. By employing optimization techniques, we systematically explore the parameter space of these algorithms to discover the most optimal configurations. Moreover, by representing …

Metrics For Comparison Of Complex Networks, Clarissa Reyes

Open Access Theses & Dissertations

Heuristic network statistics are used as a preliminary approach to identify change across networks. In networks where there is known node correspondence (KNC), conventional network comparison methods include taking a norm of the difference matrix, or calculating dissimilarity measures like DeltaCon and cut distance. Since different KNC measures provide varying insight to the network comparison problem, we propose employing Rank Score Characteristic Functions (RSCFs) and the rank-score process as a method for reaching a consensus when ranking quantified change across multiple pairs of networks â?? which is particularly useful for ranking change across subpopulations or subgraphs. Additionally, we propose a …

Using Shallow Electromagnetic And Magnetic Techniques To Map Soil Texture And Characterize Salinity And Water Dynamics Below Pecan Orchards, El Paso County, Texas, Kristina Sasser

Open Access Theses & Dissertations

Non-invasive, near surface geophysical tools provide a time efficient and cost-effective approach to study the shallow subsurface. Electromagnetic induction (EMI) instruments are a category of these near surface methods that provide spatial and temporal information (2-D to 4-D) about shallow (<6 m) subsurface properties, from which soil salinity, clay content, and water content can be estimated. However, deconstructing soil apparent electrical conductivity (ECa) from EMI methods into its component parts remains a challenge. This research uses EMI and magnetic geophysical techniques to: (1) compare and contrast the distribution and behavior of ECa, both spatially and temporally, at two flood irrigated agricultural sites (pecan orchards) with different soil layers, properties, and controls on electrical conductivities that lie within the same floodplain in far west Texas; and (2) develop a one-dimensional inversion model using ECa and soil texture data at specified layers from established sites of known high and low ECa to determine soil layer resistivities at various dates during the irrigation season. Data are compared to soil sensor bulk EC and volumetric water content data at corresponding depths to validate results. Soils at both sites exhibit large ECa contributions from textural controls, and irrigation frequency. The combination of these two controls dictate where and how quickly secondary minerals precipitate, clog soil pores, reduce infiltration, and salinize the groundwater. Insight from this research aids in ongoing efforts to characterize vadose zone hydrology in dryland critical zones with high infiltration and serves as a guide for locations where future soil sampling will occur.

Intercomparison Of Planetary Boundary Layer Over El Paso-Juarez Region Using Vaisala Ceilometers, Vianey Arvilla

Open Access Theses & Dissertations

Vaisala ceilometers (models CL 31 and Cl 51) were used to monitor and study the planetary boundary layer (PBL). There were four ceilometer stations that we connected to create the Paso del Norte ceilometer network. These stations are located at: UTEP, Socorro, Ivanhoe, and Juarez. This network has been automatized and its hourly averaged mean boundary layer height data is being downloaded into a computer accessible to TCEQ (Texas Commission on Environmental Quality) and to the public. In this study, data from each ceilometer was used to produce scatter plots. These scatter plots were analyzed to obtain the PBL heights …

Diverse Impacts Of Commercial Ev Charging Load Infrastructure On Electric Power Grid, Antonio Avila

Open Access Theses & Dissertations

With the rising prominence of electric vehicles (EVs) in the transportation sector, this thesis delves into the critical nexus between commercial EVs, charging infrastructure, and their consequential impacts on the power grid. As commercial EVs, particularly medium and heavy-duty variants, gain traction as viable alternatives in the commercial transportation landscape, understanding the intricacies of their charging requirements becomes paramount. This thesis critically examines the technological and logistical dimensions of the charging infrastructure for supporting commercial EVs, evaluating the consequential implications on the power grid and proposing strategies for mitigation through the utilization of Distributed Energy Resources (DERs). In tandem with …

Alteration And Mineralization Of The Deep Extension Of The Giant Chuquicamata Porphyry Copper Deposit, Northern Chile, Claudio Andres Araya Torres

Open Access Theses & Dissertations

Porphyry copper deposits are the major source of copper and molybdenum in the world. The deposits consist of large volumes of rock altered by hydrothermal fluids released by shallow, intermediate composition magma chambers, with metallic mineralization present in veins, breccias, and disseminations; ore grades are typically 0.3-1.0 wt.% Cu. The subject of this study, the Chuquicamata porphyry copper deposit in northern Chile, is one of the most productive such deposits in the world, with over 45 million tons of Cu produced since large scale, open pit mining started early in the XXth century. Current production at Chuquicamata is from an …

Viability Of Magnetic Nanoparticles For Magnetic Hyperthermia Cancer Therapy, Marcos Adrian Garcia

Open Access Theses & Dissertations

Over the last few decades magnetic nanoparticles have gained an extraordinary amount of attention in the science community. Their versatile use in many different research areas such as medicine, engineering and technology and many other areas has made them a popular subject. In this thesis, the synthesis of different systems of magnetic nanoparticles will be explored along with the potential use of the MNP's as viable candidates for Magnetic Hyperthermia Cancer Therapy. With values of over 200 emu/g for Iron-Silver magnetic nanoparticles with particle sizes ranging from 30-70nm and their heating properties under an AC magnetic field. As well of …

Study Of Human Circadian Protein (Hrory) And Lipid-Protein Interaction In Giant Virus (Pbcv-1), Laila Noor

Open Access Theses & Dissertations

Project 1: Circadian rhythm is a 24-hour cycle that regulates physical and behavioral changes such as sleep-wake patterns in humans, tailoring the daily light and dark changes. Long-term disruption in circadian rhythms can cause sleep disorders such as sleep apnea, insomnia, et al. Limited research has been done on potential drugs to treat against circadian related sleep disorders. Inside the cell at molecular level, the circadian rhythm is regulated by interlocked time-delayed feedback loops, which involve positive and negative transcriptional regulators. Experimental results showed transcriptional factors Retinoic Acid Receptor-Related Orphan Receptors (RORs) improve the stability and functionality of the circadian …

Synthesis And Characterization Of Acetaminophen-Derived Nanoparticles: A Novel Approach To Inhibit Fibril Formation, Hannia Elena Mendoza-Dickey

Open Access Theses & Dissertations

In the realm of nanotechnology, nanoparticles (NPs), have garnered significant notoriety in recent scientific research due to their unique physical and chemical properties, such as fluorescence emissions, nanoscale dimensions (typically <1000 nm), ease of surface modification, and biocompatibility. Nanoparticles have shown their potential across a variety of areas, including advanced industrial applications and cutting-edge biomedical research. Considering their cost-effective synthesis, they have shown promise as therapeutic agents for a variety of bioimaging and biomedical applications. This thesis describes the synthesis and detailed analysis of acetaminophen-derived nanoparticles. Techniques such as Dynamic Light Scattering (DLS), Thioflavin T (THT) assay, Attenuated Total Reflectance Infrared Spectroscopy (ATR-IR), 1H NMR spectroscopy, and Ultraviolet-Visible Spectroscopy (UV-VIS) were utilized for structural and functional assessments. Acetaminophen derived nanoparticles (ANPs) exhibit potential to hinder the amyloidogenic conversion of soluble amyloid-forming proteins into their toxic form. The novelty of this research focuses on the utilization of chemical structures capable of traversing the Blood Brain Barrier (BBB) to mitigate xenotoxicant-induced neuronal damage, a notable contributor to neurodegenerative disorders. This thesis describes the synthesis and characterization of acetaminophen derived-nanoparticles (ANPs). Our nanoparticles possess anti-amyloidogenic properties as evidenced by their ability to disrupt in the soluble-to-toxic trajectory of HEWL. The prevalence and evolution of amyloid fibrils are consistent features in the pathology of neurodegenerative diseases such as Parkinson's disease (PD), Alzheimerâ??s Disease (AD), and Huntingtonâ??s Disease (HD), as well as metabolic disorders like Type 2 diabetes (T2D). The relationship between amyloidogenic pathways and these disorders highlights the imperative for enhanced understanding and the formulation of specific therapeutic interventions.

Towards Explaining Neural Networks: Tools For Visualizing Activations And Parameters, Juan Puebla

Open Access Theses & Dissertations

There is a growing number of applications using neural networks for making decisions. However, there is a general lack of understanding of how neural networks work. Neural networks have even been described as black boxes which has led to a lack of trust in artificially intelligent programs. To remedy this, explainable artificial intelligence has risen as a means to validate the decision-making processes and the results of computer programs that use artificial intelligence. The work in this masterâ??s thesis is our contribution to explainable artificial intelligence, focusing on neural networks with the goal of helping users make more sense of …

Preliminary Assessment For Critical Minerals In The Terlingua Quicksilver District, Texas And Tres Marias Mine, Chihuahua, Mexico, Eduardo Lee Zuniga

Open Access Theses & Dissertations

The Terlingua Quicksilver district was discovered around the 1880s and was a mercury producing district from 1900 through 1946. The most productive years were during World War one and two. From 1900-1946 the Terlingua Quicksilver District (TQD) produced 150,000 flasks; 80% came from three mines: the Rainbow-Chisos, Mariposa, and Study Butte mines. The structural controls of the Mercury mineralization within these mines are breccia pipes and fractures, often located near igneous intrusions. This study will assess the potential for Critical Minerals and Rare Earth Elements in the Terlingua Quicksilver District. Fifty-five samples have been collected and analyzed for forty-four different …

Inkjet-Printed Electrochemical Sensors For Lead Detection, Annatoma Arif

Open Access Theses & Dissertations

This PhD dissertation research has developed a simple, miniaturized, sensitive, selective, reproducible, and disposable 3D (inkjet printed – additive manufacturing technology) gold (Au) plated electrochemical sensor (ECS) on shape memory polymer (SMP) for aqueous lead detection. This technology has shown promising performance in the application of electrochemical sensing (lead (II) detection) due to increased effective electrode surface area (7.25 mm^2 ± 0.15 mm^2) despite miniaturizing lateral surface area (4.19 mm^2). The design, fabrication processes, optimization including bismuth functionalization, evaluation, uncertainty analysis, and cost analysis of the novel SMP based inkjet printed Au plated sensor have been delineated in this manuscript …