Digital Commons Network^™

Wirelessly Powering A Sea Of Sensors For Perimeter Security Applications, Ian River Chavez

Electrical and Computer Engineering ETDs

his thesis presents an innovative application of Inductive Power Transfer (IPT) technology for perimeter security systems. The approach leverages the physical properties of IPT to detect intrusions by monitoring voltage changes in wirelessly powered sensor nodes, which can double as components of an intrusion detection system. Disturbances in node orientation, indicative of potential intrusions, alter the sensor node’s resonant frequency and create measurable voltage shifts. This study explores the concept in-depth, from the analysis of resonant inductive coupling in various resonant inductive modes, to the design of transmit loops, sensor nodes, and the techniques required to ensure optimum power transfer. …

Noise-Resilient And Adaptive Distributed Control Techniques For Microgrids, Seyed Iman Habibi

Electrical and Computer Engineering ETDs

This dissertation focuses on addressing the critical tasks of secondary control in microgrids, particularly in the islanding operating mode. The presence of noise in sensors and communication links necessitates the design of a noise-resilient secondary control approach. In response, this dissertation introduces the Nonlinear Generalized Minimum Variance (NGMV) control approach into the islanded AC and DC microgrid's secondary control system. The effectiveness of the proposed approach is demonstrated through MATLAB simulations. Additionally, the dissertation presents an adaptive, model-free, and data-driven control approach for secondary voltage control in AC microgrids, addressing uncertainties. By employing Unfalsified Adaptive Control (UAC), the approach selects …

Application Of Quantum Mechanical Techniques To Optical Waveguide Structures, Stuart Ward

Physics & Astronomy ETDs

The focus of this dissertation is on the application of supersymmetric quantum mechanics to the problem of microbending in optical waveguides and on the analysis of soliton decay due solely to quantum mechanical effects.

The techniques of supersymmetric quantum mechanics are applied to the equation of motion describing light propagation in an optical waveguide which is undergoing microbending. Based on these supersymmetric techniques, given a particular refractive index profile, one may derive a new refractive index profile which results in less loss due to the microbending -- the particular example of the monomial index profile is analyzed in detail. An …

Myeloid Fth1 Deficiency Protects Mice From Colitis And Colitis-Associated Colorectal Cancer Via Reducing Dmt1-Imported Iron And Stat3 Activation, Zhaoli Liu, Mariella Arcos, David R. Martin, Xiang Xue

Pathology Research and Scholarship

BACKGROUND: Myeloid cells are critical for iron and immune homeostasis. Ferritin heavy chain (FTH1) is essential for intracellular iron storage. Myeloid FTH1 is important in the pathogenesis of many inflammatory diseases. However, the role of myeloid FTH1 in colitis and colitis-associated cancer has not been determined.

METHODS: Myeloid FTH1 deficient and wild-type mice were treated with dextran sodium sulfate (DSS) or azoxymethane (AOM)-DSS to compare their susceptibility to acute colitis or colitis-associated cancer.

RESULTS: Myeloid FTH1-deficient mice fed with a high-iron diet were less susceptible to DSS-induced acute colitis than wild type mice. Mechanistic studies showed that myeloid FTH1 deficiency …

The Antiviral Effects Of A Mek1/2 Inhibitor Promote Tumor Regression In A Preclinical Model Of Human Papillomavirus Infection-Induced Tumorigenesis, Adrian J. Luna, Jesse M. Young, Rosa T. Sterk, Virginie Bondu, Fred A. Schultz, Donna F. Kusewitt, Huining Kang, Michelle A. Ozbun

Pathology Research and Scholarship

Human papillomaviruses (HPVs) are a significant public health concern due to their widespread transmission, morbidity, and oncogenic potential. Despite efficacious vaccines, millions of unvaccinated individuals and those with existing infections will develop HPV-related diseases for the next two decades and beyond. The continuing burden of HPV-related diseases is exacerbated by the lack of effective therapies or cures for infections, highlighting the need to identify and develop antivirals. The experimental murine papillomavirus type 1 (MmuPV1) model provides opportunities to study papillomavirus pathogenesis in cutaneous epithelium, the oral cavity, and the anogenital tract. However, to date the MmuPV1 infection model has not …

Seismic Analysis Of The Upper & Lower Falls Of The Yellowstone River, Loring Schaible

Earth and Planetary Sciences ETDs

Twelve years of concurrent hydrologic and continuous seismic data along with temporary seismic data demonstrate that the Upper and Lower Falls of the Grand Canyon of the Yellowstone River comprise a highly localized source of 0.5-5 Hz seismic energy that overwhelms anthropogenic contributions. In aggregate, seismic amplitude from 2008-2019 is linearly related to discharge with a correlation coefficient of 0.96. Repeated deviations from this linear relationship persist for 1-2 weeks prior to the date that Yellowstone Lake becomes clear of winter ice coverage. Seismic efficiency increases by ~50-250% during this period of ice-breakup, during which lake ice flows into the …

Investigation Of Issues Concerning Wellbore Leakage, Ishtiaque Anwar

Civil Engineering ETDs

A range of applications, such as subsurface fluid storage facilities, geothermal wells, and CO2 storage wells, are concerned about leakage along wellbores. The research described in this dissertation was largely directed toward wellbore leakage concerns for the US Strategic Petroleum Reserve (SPR). For SPR wellbores, multiple fluids are likely to exist in fractures and flow paths associated with leaky wellbores, including liquids (e.g., liquid hydrocarbon - crude oil) and gases (e.g., gas ex-solved from liquid and/or nitrogen from MIT tests). Anomalous pressure records have been observed at the wellhead of SPR wellbores, indicative of wellbore leakage. In a few cases, …

Repair Of A Wellbore Microannulus, Serafin Garcia Fernandez

Civil Engineering ETDs

In wellbore systems, the microannulus between the steel and the cement has been shown to be a critical leakage pathway. This microannulus offers unique roughness, aperture distribution, and wetting conditions, which are critical in understanding and explaining the potential sealing efficiency of a repair material. An experimental configuration was developed to better understand how a repair material would displace an existing material in the microannulus, visually evaluate potential instabilities on the flow patterns developed, and how efficient the potential repair would be. For that purpose, the experimental configuration consisted of a planar, rough cement surface and a transparent acrylic plate …

Experimental And Numerical Investigation Of Fluid Flow Behavior Through Fractured Wellbore Cement, Mahya Hatambeigi

Civil Engineering ETDs

Leakage from wellbores has been a major challenge in the energy industry, leading to groundwater contamination, reduced productivity, safety hazards, and increased operating costs. Cemented annulus fractures are a common type of leakage pathway in wellbores that can form due to various physical and chemical conditions. The number of wellbore leaks continues to increase globally, making it imperative to develop a better understanding of the complex mechanisms governing fluid flow through fractured wellbore cement. Understanding the behavior of fluid flow through a leaky cemented annulus is crucial for evaluating the leakage potential and risk assessments in wellbore systems, as well …

The Economic Impact Of Oil And Gas Production In The Permian Basin, Aditi Sarkar

Economics ETDs

The dissertation aims to analyze the economic and social consequences of unconventional oil and gas (UO&G) production in the Permian Basin, located in southeastern New Mexico and West Texas. The first paper focuses on the effect of methane reduction regulations imposed by the United States (US) government on the production of natural gas and the drilling of new wells. Specifically, the question asked is “what is the impact of methane reduction regulations on the drilling of new wells and the production of natural gas over a 40-year time horizon?” I develop dynamic optimization in a system dynamic setting to assess …

Essays On Human Capital, Labor, And Gender, Kritika Sen Chakraborty

Economics ETDs

This dissertation is a collection of chapters that demonstrate the factors affecting human capital and labor market outcomes of adolescents and the gender differences in the quality of employment of adults in South Africa.

The second chapter evaluates the impact of South Africa’s Child Support Grant, an unconditional means-tested grant provided to age-eligible children, on adolescent nutrition outcomes. The findings suggest that welfare programs can alleviate extreme undernutrition and overnutrition among females during the critical growth period of adolescence.

In the third chapter, I use longitudinal data from rural South Africa linked with geospatial climate indicators to examine the effect …

Three Essays On The Economics Of Children’S Health And Education In Nepal, Khusiman Pun

Economics ETDs

First essay: This paper studies the impact of Nepal’s 1996-2006 Maoist insurgency on the nutritional status of children. We employ the difference-in-difference (DID) model. The proxy for conflict intensity is killings per thousand population (KPT). The finding of our study is that a marginal increase in KPT decreases the height-for-age (HAZ) of the children by 0.0844. The loss in child health was statistically not significant in both non-poor and poor households. Therefore, the impact of the insurgency on child health is largely driven by the negative effect of the insurgency on Janajaties, irrespective of their economic status.

Second essay: This …

Between Casas Grandes And Salado: Community Formation And Interaction In The Borderlands Of The American Southwest/Mexican Northwest Region, Ad 1200-1450, Thatcher Andrew Seltzer-Rogers

Anthropology ETDs

The historical record of Indigenous North America at the time of European colonization attests to the presence of borderlands between competing culture cores. Yet, the oftentimes inability of the archaeological record to speak to the presence of such dynamics in the past remains a hinderance to understanding how past peoples engaged with one another in noncolonial settings as well as how these interactions resulted in ethnogenesis or the establishment of new culture cores. This dissertation uses a comparative analysis of settlement layout, architecture traits, ceramic artifacts, and mortuary practices to examine how individuals who resided in the space between two …

Near- And Far- Field Optical Response Of Ensembles Of Nanostructures, Lauren Zundel

Physics & Astronomy ETDs

The ability of metallic nanostructures to support collective oscillations of their conduction electrons, known as surface plasmons, makes them attractive candidates for a wide range of applications in areas as diverse as cancer therapy, biosensing, and solar energy harvesting. These applications are especially promising for periodic arrays of nanostructures, which can support collective modes known as lattice resonances, and for nanostructures with extreme aspect ratios that give rise to enhanced light-matter interaction. In this Thesis, we employ a coupled dipole model to theoretically explore the lattice resonances supported by complex arrays of nanoparticles containing multiple nanoparticles per unit cell. We …

The Haunting Aesthetics Of Empire: Filipinx America, Us Empire, And Cultural Production, Alana J. Bock

American Studies ETDs

Throughout this dissertation, I argue that US imperial knowledge production affirms US exceptionalism by disavowing the imperial violence wrought on the Philippines and its people. This disavowal not only renders the Philippines and Filipinx bodies illegible, but also haunts the Filipinx American diaspora. I argue that the haunted logics of empire are a set of relations, rather than specters of specific times and places, in which knowledge and power work together to continually produce and reproduce a specific and limiting reality and sensorium through which to view the world. In my interrogation of empire’s haunted logics, I not only look …

Examining The Effects Of Iron-Oxide Nanoparticles On Primary Gingival Keratinocytes For The Prevention Of Oral Disease, Jennifer C. Carranza

Dental Hygiene ETDs

Oral plaque biofilm has been identified as the primary contributor to dental conditions such as dental caries and periodontal disease that promotes a diverse and pervasive collection of microbial species to inhabit the oral cavity. Disrupting the plaque matrix early could help combat this global disease burden. This study evaluated the effect of IONPs on primary gingival keratinocytes.

Purpose: This study aimed to examine existing research regarding nanoparticles and determine if IONPs affect the PGK cell membranes with preliminary research to find the maximum lysis possible with PGK cells.

Methods: IONP core/shell syntheses were performed. Considering keratinocyte characteristics, examining data …

Postwar Cooperative Housing: On The Historical And Community Significance Of South Dahlia Lane, John Boydstun

Architecture and Planning ETDs

American cities after WWII including Denver experienced a boom in population resulting in a shortage of affordable housing. One innovative response to the demand for affordable housing was the formation of the Mile High Housing Association (MHHA), a Colorado non-profit organization founded in 1948 by four University of Denver professors. The MHHA was Colorado’s first housing cooperative and founded on the ideals of a supportive and collaborative community. MHHA’s goals included providing affordable single-family homes with a new modernist design and a neighborhood site plan that supported a cooperative lifestyle. Backed by new legislation in 1948 for FHA financing, the …

Probabilistic Modeling Of Social Media Networks, Distinguishing Phylogenetic Networks From Trees, And Fairness In Service Queues, Md Rashidul Hasan

Mathematics & Statistics ETDs

In this dissertation, three primary issues are explored. The first subject exposes who-saw-from-whom pathways in post-specific dissemination networks in social media platforms. We describe a network-based approach for temporal, textual, and post-diffusion network inference. The conditional point process method discovers the most probable diffusion network. The tool is capable of meaningful analysis of hundreds of post shares. Inferred diffusion networks demonstrate disparities in information distribution between user groups (confirmed versus unverified, conservative versus liberal) and local communities (political, entrepreneurial, etc.). A promising approach for quantifying post-impact, we observe discrepancies in inferred networks that indicate the disproportionate amount of automated bots. …

An Investigation Of Freshwater Turtle Ecology Using Stable Isotopes, Jonathan Duran

Biology ETDs

In 2022 I investigated niche partitioning among native and invasive freshwater turtles across three sites in the Middle Rio Grande using bulk stable isotope analysis. I found high degrees of niche partitioning at sites in which Red-eared sliders (Trachemys scripta) have yet to establish. However, at sites in which red-eared sliders are now the most abundant species they overlapped greatly in isotopic niche with all native turtles, in particular the painted turtle (Chrysemys picta). Using these same techniques, I then examined the trophic interactions between red-eared sliders and their acanthocephalan parasites. My results suggest that acanthocephalans …

Diversification By Dispersal Out Of The Andes Revealed By A Newly Discovered Hummingbird Clade, The ‘True Brilliants’, Marialejandra Castro-Farías

Biology ETDs

We identified a novel clade with striking biogeographic implications. Unsampled genera, Hylonympha and Sternoclyta, were found to be close to the genus Heliodoxa within the Brilliants. Heliodoxa tend to occur in lower montane habitats, such as the tropical, upper tropical, and subtropical elevational zones of the Andes and the Neotropics. Analysis of geographic and elevational zones showed that genus Heliodoxa and related genera diversified by out-of-Andes dispersal to mountain ranges of Central America, coastal Venezuela, the Pantepui, and southeastern Brazil, since the mid-Miocene. Within the Brilliants, reductions in elevation preceded these geographic expansions. Secondary colonization of the lowlands from …

Post-Fire Plant Community Response In Subalpine Mixed Conifer Forest, Sasha Escamilla

Biology ETDs

Increased wildfire activity may lead to significant shifts in vegetation dynamics in high elevation mixed conifer forests. These changes raise concerns about the resilience of forests following wildfire, prompting the need for a deeper understanding of post-fire plant community response. We analyzed up to 11 years of post-fire vegetation data from Valles Caldera National Preserve in northern New Mexico to determine how burned vegetation sites were recovering following high severity wildfire, and whether or not plant communities were transitioning to montane grassland. We found burned understory herbaceous communities were not transitioning into distinctive montane grasslands and were instead recovering to …

Evidence Of Competitive Release Following Overstory Mortality In A Semi-Arid Piñon-Juniper Woodland, Corrie D. Gonzalez

Biology ETDs

Extreme temperatures and severe drought events have led to widespread tree mortality worldwide. In semi-arid regions of the Southwest United States, these events pose a significant threat to piñon-juniper (PJ) woodlands. We studied the effects of piñon and juniper mortality on the growth and physiology of existing saplings in PJ woodlands by analyzing water status, photosynthetic activity, and tissue chemistry to gain insights into these impacts. Juniper saplings exhibited improved water status and water use efficiency in response to overstory mortality, whereas piñon saplings did not. Additionally, both piñon and juniper saplings exhibited increased photosynthetic rates, increased photosynthetic capacity, and …

Thermoregulation In Nocturnal Volant Endotherms Occupying Hot Deserts, William A. Talbot

Biology ETDs

The study of thermoregulation is of growing concern in this era of rapid climate change. Earlier studies such as those pioneered by Scholander and Bartholomew directed focus toward the study of endotherm survival in conditions of cold weather adversity. As techniques evolved in the measurement of parameters quantifying thermoregulation, metabolism and energy allocation, the standardization procedures has increased the comparability of data from diverse taxa. We can now search historical records and current research for explanations to the changes in the distribution, migration, extirpation or survival of animal and plant populations through time. It is increasingly common to observe dramatic …

Resolving The Paradox Of Polyploidy: Underexplored Facets Of Polyploid Plants, Benjamin P. Gerstner

Biology ETDs

Polyploidy, or whole genome duplication, is a common phenomenon in plants, but the establishment and persistence of mixed-ploidy populations remains a paradox. This dissertation explores factors that contribute to the persistence and establishment of mixed-ploidy populations in nature. The first chapter investigates the role of unreduced gametes in neopolyploid establishment and finds that variability in their formation rate can have a significant impact on polyploid establishment and persistence. The second chapter searches for evidence of soil microbes exhibiting ploidy-specificity, a pre-condition for microbe-mediated niche differentiation, a possible stabilizing mechanism contributing to ploidy coexistence. Finally, the third chapter tests for microbe-mediated …

Investigation Of Orthohantavirus Genetics In Rodent Reservoirs And Clinical Samples, Samuel Melvin Goodfellow

Biomedical Sciences ETDs

Orthohantaviruses are negative-sense, single stranded RNA viruses with trisegmented genomes that can cause severe disease in humans and are carried by several host reservoirs throughout the world. In the United States, Sin Nombre orthohantavirus (SNV) is the primary cause of hantavirus cardiopulmonary syndrome (HCPS) with a fatality rate of ~36% and the highest cases occuring in the southwest region. The primary SNV host reservoir is thought to be the western deer mouse, Peromyscus maniculatus, however it has been shown that other rodents can carry different orthohantaviruses. We designed a pan-orthohantavirus detection tool to survey several small mammal populations throughout New …

High P-T Single Crystal Elasticity Of Zircon And Its Implications For Determining Metamorphic P-T Conditions In Nature, Arlacee Luu

Earth and Planetary Sciences ETDs

Understanding the natural petrologic and tectonic processes, such as slab subduction, requires accurate determination of the pressure (P) and temperature (T) conditions of these processes. Recent development of elastic thermobarometry based on the difference between the elastic evolution of mineral inclusions and their host minerals allows constraining the formation P-T conditions of the inclusion/host system without assuming thermodynamic equilibrium, which is typically needed for the widely used chemistry-based thermobarometry in metamorphic petrology. However, the reliability of elastic thermobarometry heavily depends on the accurate determination of the high P-T single-crystal elastic properties of relevant minerals. In this study, we performed the …

Testing The Niche Center Hypothesis In The Fossil Record Of Atlantic Bivalves, Rhiannon Z. Nolan

Earth and Planetary Sciences ETDs

Paleoecological analyses of six shallow marine bivalves were conducted to test the Abundant Center Hypothesis using data from the fossil record of the Pleistocene through modern day. This hypothesis predicts the highest abundance of a species is at the center of the geographic or environmental range, decreasing toward the edges. In geographic space, distances to a centerline within a geographic range were variably correlated with population abundances, and some species displayed a sharp drop-off in abundance as distance increased. In environmental space, bivalve species showed moderate correlations between abundance and centrality when measured using cumulative data across the last 2.8 …

Seismic Shadow Zone Investigation In The Upper Magma Reservoir Of The Yellowstone Caldera, Sarah Nolt-Caraway

Earth and Planetary Sciences ETDs

This study investigates whether the Yellowstone Caldera has enough melt to mute S-waves, creating a seismic shadow zone. Using a dense nodal deployment of ~650 stations, 7-9 earthquakes during the nodal deployment, and 21 broadband stations with 3,000-4,000 events per station; amplitude and noise maps, seismograms, and automatic phase picks probabilities from a deep learning model were analyzed to assess the potential role of melt, crustal attenuation, and noise in affecting body waves, particularly S-phases. The results are inconclusive, with unclear evidence whether observed amplitude decay is normal signal decay due to distance, noise-related, melt, or from scattering and intrinsic …

Weathering, Erosion, And Dust Accumulation At Stoneman Lake, Arizona, Usa: Timescales And Drivers Of Geomorphic Activity Across The Southwest, Spencer Staley, Peter J. Fawcett, R. Scott Anderson, Gonzalo Jiménez-Moreno, Vera Markgraf, Erik T. Brown, Matthew E. Kirby

Earth and Planetary Sciences ETDs

Lengthy and well-dated terrestrial records of the Quaternary Period with the appropriate proxies show how the critical zone responds to environmental change. In southwestern North America, resolving the many effects of aridity through time provides crucial context for addressing contemporary climate issues. However, arid conditions are generally non-conducive to paleo-record preservation, causing knowledge gaps during relevant climatic episodes. An ~80 m-long sediment core (STL14) from Stoneman Lake contains a continuous archive of conditions from local to regional scale since the early Pleistocene (~1.3 Ma) and is, therefore, a unique and immensely valuable scientific resource. STL is situated in a montane …

Examining The Measurement Invariance Of The Revised Sociosexual Orientation Inventory Among Hispanic And Non-Hispanic White College Women, Christina Nicole Gillezeau

Psychology ETDs

I examined whether the Revised Sociosexual Orientation Inventory (SOI-R) was invariant between Hispanic/Latina and Non-Hispanic White (NHW) undergraduate women. I performed confirmatory factor analysis to assess model fit and used increasingly restrictive models to test invariance. I included 208 Hispanic/Latina women and 190 NHW women. The CFI and RMSEA model fit statistics (CFI=0.98, RMSEA=0.06 (90% confidence interval=0.04-0.08, p-value=0.16) showed that the model fit well. I constrained factor loadings to be equal in both groups to test metric invariance. I observed non-significant differences in model fit (deltaX² (9)=88.67, p>0.95, deltaCFI=0.003, deltaRMSEA=-0.011). I also constrained intercepts to be equal to …