Digital Commons Network^™

Internal Waves Of Port Everglades: Experimental And Numerical Studies To Characterize Ambient Magnetic Signals, Johanna Riley Evans

Theses and Dissertations

Ocean dynamics are an important contributing factor to measurable environmental magnetic noise. Seawater is conductive and as an internal wave oscillates across Earth’s magnetic field, a small yet detectable induced magnetic field develops. A significant source of underwater magnetic noise off the southeast coast of Florida comes from internal waves. Characterizing the magnetic signals present required a combination of computational modeling effort and field experiments. For this research, undersea sensors were monitored as a continuous field experiment and a computational fluid dynamic (CFD) magneto-hydrodynamic (MHD) model was customized to simulate internal wave-induced magnetic fields at the site. I developed the …

Evolutionary Cartographies Of Language Diversification: Quantitative Approaches To The Geolinguistic Mapping Of The Kayanic Languages (Central Borneo), Deandré A. Espree-Conaway

Theses and Dissertations

Why are there so many languages in the world and how did this diversity come about? Every day, humans around the world speak over 7,000 languages. One of the most impactful theories describing the processes and mechanisms of language diversification is that of the Linguistic Niche Hypothesis (Lupyan & Dale 2010). The Linguistic Niche Hypothesis suggests that languages adapt to their environments (Lupyan & Dale 2010: 1). Lupyan and Dale describe it, stating that "just as biological organisms are shaped by ecological niches, languages structures...adapt to the environment (niche) in which they are being learned and used" (2010: 1). Taking …

Developmental Evaluation Of The B-1b Aircraft, Jonathon Malycke

Theses and Dissertations

The purpose of this test was to perform a Developmental Phase IIA evaluation of the B-1B Lancer for the land-based, long-range, all-weather ground attack mission. One two-hour ground evaluation, one simulator and one flight totaling 7.5 hours was conducted under daylight, visual meteorological conditions from Dyess Air Force Base (AFB) in Abilene, Texas (337th Test and Evaluation Squadron). All test objectives were completed except the low altitude flight evaluation, landing pattern operations, and AFCS operations due to weather, maintenance and time constraints. The test aircraft was representative of a production B-1B aircraft and included a Sniper Targeting Pod and a …

Operational And Cost Analysis Of A Leo Radar-Based Satellite Constellation, Kyle O. Norbert

Theses and Dissertations

This thesis presents a methodology to assess the ability of a Low-Earth Orbit (LEO) satellite constellation to successfully accomplish the GMTI mission in a cost-effective fashion. A simulation model was developed to test the coverage performance of 512 unique constellation designs. Significant factors were revealed by developing regression models that revealed the most critical constellation trade-offs on measures of performance. A Value-Focused Thinking (VFT) approach was applied to assign weights to a broad range of measures of performance from which the Pareto distribution on a cost-capability plot revealed cost-effectiveness. A novel measure of performance was developed and analyzed that accounted …

Employment Transitions From Active-Duty Army Officer To Civilian: An Exploration Of The Knowledge, Skills, And Abilities Possessed By Combat-Experienced, Army Field-Grade Officers, James Daniel Crook

Theses and Dissertations

Two decades of wars in Iraq and Afghanistan have concluded, bringing an end to the longest military conflicts in the history of the United States of America. Following the example of post-war history, the military’s posture is to reduce personnel end-strength. The post-war military requires fewer soldiers, and a significant number of transitioning officers make the journey from military to civilian employment. This quantitative study discovered the knowledge, skills, and abilities of combat-experienced, active-duty, Army field-grade officers and explored the change from military to civilian employment. This study addressed the gap in the literature regarding this specific group of transitioning …

Simeon Hart, The "Milmo Affair," And The Confederate Cotton Trade On The Rio Grande, 1861-65, Leonel Rodriguez

Theses and Dissertations

The cotton trade on the Rio Grande played a crucial role in the transnational history of Confederate-Mexican diplomacy as well as the history of the American Civil War and the Second French Intervention in Mexico. The renowned merchant from El Paso, Simeon Hart, was an important figure in the cotton trade since he helped facilitate diplomatic and commercial relations between Mexico and the Confederacy. Due to his reputation as an emissary and supplier for the Confederate Army of New Mexico, Hart was appointed quartermaster of the Trans-Mississippi Department. During the winter of 1863-64, the son-in-law of the Governor of Nuevo …

Exploring Misinformation Campaigns And How To Defend Against Them, Michelle S. Kuralt

Theses and Dissertations

Misinformation campaigns can have very real and lasting effects. Misinformation has been known to impact elections, create vaccine hesitancy, and increase polarization within societies. This paper reviewed existing literature regarding misinformation research, collected information from research participants to discern factors which may contribute to an increased susceptibility to misinformation, and examined Rule Based Training and a training program which utilized both rules and mindfulness to ascertain if these training programs might be effective in reducing participant susceptibility to misinformation.

Trypanosome Infection Disturbs The Gut Microbiota Of Bumble Bee Hosts, Bryan Sierra-Rivera

Theses and Dissertations

Host-microbe interactions are ubiquitous with both positive and negative outcomes for host health and fitness. While pathogens abound, there has been an increased focus beneficial host-microbial community associations, such as native gut microbiota that can aid in disease resistance, nutrient sequestration, and detoxification. However, while beneficial microbes can protect against infection, there is a limited appreciation for how pathogen infection may disrupt healthy gut microbiota structure and function. Crithidia bombi is a common trypanosomatid gut parasite of bumble bees with fitness-relevant effects on individuals and colonies. The native bumble bee gut microbiota has been shown to increase protection against Crithidia, …

Cultural Exchange: Defining The Native American And African Slave Interaction At Rich Neck Plantation, Theartis R. Butler

Theses and Dissertations

Surprisingly few studies of the history of American slavery have investigated the interconnectedness of Native Americans and Africans and African Americans. We now know Native Americans were instrumental in helping the first trans-Atlantic colonizers settle in the Americas. However, history shows that this alliance did not last, and settlers took Native American lands. While settlers dispossessed Indigenous peoples, they also shifted the sources of labor for their new plantations on unceded land. Native Americans were the first source of cheap, coerced labor. American slavery eventually brought Africans from their homes to the early American colonies. Africans had to learn and …

Conflict And Nature: How War In Cambodia Shaped Its Natural Landscape, Emily Lifs

Theses and Dissertations

Through the efforts of the Cambodian people and historians, the world is familiar with the tragic human story that unfolded over decades of war and the brutal rule of the Khmer Rouge. This thesis is an attempt to tell the equally tragic but untold story of how decades of conflict shaped the Cambodian landscape and the lives and populations of elephants and other animals.

Investigation Of Polymer Nanocomposites With Silicon Dioxide Fillers As Helium Cooled High-Temperature Superconducting Cable Dielectrics, Jordan Thomas Cook

Theses and Dissertations

In this thesis, three polymer nanocomposite configurations are fabricated for investigation as dielectrics in helium-cooled high-temperature superconducting (HTS) cables. Polyimide, polyamide, and polymethyl methacrylate are utilized as host polymers. The composite samples are synthesized through an in situ process, dispersing silicon dioxide nanoparticles throughout the polymer hosts. Fourier transform infrared spectroscopy and scanning electron microscopy were employed to validate the synthesis of each composite configuration. Thin film samples of each configuration were also tested for their dielectric strength at both room (300 K) and cryogenic (92 K) temperatures. When going from room to cryogenic temperatures, all materials demonstrated a significant …

Analysis Of Selected Pieces Influenced By Taiwanese Aboriginal Music For Solo Violin And String Quartet, Isabel Hsin-Yi Ong

Theses and Dissertations

This is an analysis of three pieces that contribute to solo violin and string quartet repertoire through the lens of intervallic relationships, rhythmic and gestural motifs, and instrumental technique. Briefly delving into the Aboriginal history of Taiwan and illuminating aural concepts inherent within each tribe, the research blends musicological research, theoretical analysis, and intuitive performance-based interpretations to meld and expand the technical and musical possibilities of the violin with the essence and impact of these songs.

Low Temperature Dielectric Strength Of Polyimide-Silica Nanocomposites For Applications In High-Temperature Superconducting Cables, Michael John Mccaffrey

Theses and Dissertations

Gaseous helium is often considered as an alternative to liquid nitrogen to cool modern high-temperature superconducting cables in support of increased power capacity and/or reduction of required cable size. However, the small size of helium molecules and relatively poor dielectric strength of helium gas create challenges which limit the usefulness of modern cable dielectrics. Continuous dielectric coatings have been considered as an alternative to traditional lapped tape dielectrics to support gaseous helium refrigerants, but unmatched thermal contraction between the coating and cable components would induce failures due to mechanical stress. Composite materials have been considered as a means of matching …

A Methodological Framework For Parametric Combat Analysis, Dustin L. Hayhurst Sr.

Theses and Dissertations

This work presents a taxonomic structure for understanding the tension between certain factors of stability for game-theoretic outcomes such as Nash optimality, Pareto optimality, and balance optimality and then applies such game-theoretic concepts to the advancement of strategic thought on spacepower. This work successfully adapts and applies combat modeling theory to the evaluation of cislunar space conflict. This work provides evidence that the reliability characteristics of small spacecraft share similarities to the reliability characteristics of large spacecraft. Using these novel foundational concepts, this dissertation develops and presents a parametric methodological framework capable of analyzing the efficacy of heterogeneous force compositions …

Generative Methods, Meta-Learning, And Meta-Heuristics For Robust Cyber Defense, Marc W. Chalé

Theses and Dissertations

Cyberspace is the digital communications network that supports the internet of battlefield things (IoBT), the model by which defense-centric sensors, computers, actuators and humans are digitally connected. A secure IoBT infrastructure facilitates real time implementation of the observe, orient, decide, act (OODA) loop across distributed subsystems. Successful hacking efforts by cyber criminals and strategic adversaries suggest that cyber systems such as the IoBT are not secure. Three lines of effort demonstrate a path towards a more robust IoBT. First, a baseline data set of enterprise cyber network traffic was collected and modelled with generative methods allowing the generation of realistic, …

Democracy Or Capitalism? The United States And Latin America, Grace Burgener

Theses and Dissertations

The democratic peace theory holds that democracies rarely, if ever, go to war with one another based on the institutional and normative features of democratic governments. Alternatively, the capitalist peace theory insists that, rather than the democratic nature of a government, states opt out of warfare when their economic interests are at play – whether that be trade interdependence or general market features. Traditionally, scholars have focused on explaining the causes of Militarized Interstate Disputes (MIDs) among advanced industrialized democracies. Based on the tenets of capitalism and a new outcome variable of intervention (e.g., coups), this thesis uses two instances …

Weaving Ethnic Identity: Discovering The Threads Of Multilingual Diversity In The Fabric Of Group Identity Among Karen Communities Of Denver, Colorado, Charity J. Seidler

Theses and Dissertations

How do Karen immigrants use language within Colorado communities? My thesis answers this question through narrative case studies of six S’gaw Karen women. Many Karen refugees, who flee the decades-long conflict within their homeland in Myanmar (Burma), find themselves navigating life first in Thailand, and eventually in the United States as foreign-language speakers. These refugees encounter numerous linguistic and cultural barriers in their new U.S. homeland, where it is difficult to function in many domains if they do not have the opportunity to learn much English upon arrival.

The six case studies are based on recorded sociolinguistic qualitative open interviews. …

Assessing New Wars Theory In The Post-Arab Spring Era: The Libyan And Yemeni Wars (2011-2020), Shady El-Sherif

Theses and Dissertations

Mary Kaldor’s “New Wars” theory which was first published in 1991 argues that warfare has changed after the Cold War with the growing globalization and the rise of violent non-state actors. According to the theory, globalization augmented certain problems that are considered the main causes of these “new wars” such as; state fragility/failure, identity politics, and war economy methods which all account at present for the continuation of conflicts, especially in the MENA region with more civilian casualties. To assess this theory, I am using a comparative case study methodology with a historical process-tracing approach for the Yemeni and Libyan …

Water-Soluble Porphyrin Complexes For The Biological Inactivation Of Fentanyl, Anneli Nina

Theses and Dissertations

This work aimed to investigate the degradation of fentanyl in aqueous solutions using unsupported water-soluble cobalt(III) porphyrins (55 and 56), AuNP supported water-soluble cobalt(III) porphyrins (67 and 68), and liposome supported water-soluble cobalt(III) porphyrins (69 and 70). Complexes 55, 56, 68, and 69 have been shown to remove fentanyl from aqueous solutions at 37 ºC. The degradation of fentanyl, and the identification of breakdown products were analyzed with the use of time-of-flight mass spectrometry (TOFMS). Complex 55 has been shown to completely degrade fentanyl at 37 ºC in as little as two hours with a 400 mol% catalyst loading. Complex …

Electromagnetic Interference Shielding Effectiveness Of A Layered System Consisting Of A Carbon Nano-Reinforced Polymer Composite Coated With Metal Oxide And Graphite, Veronica Montserrat Serrato

Theses and Dissertations

In this study, the electromagnetic interference (EMI) shielding effectiveness (SE) of vapor grown carbon nanofiber (VGCNF) reinforced polyvinylidene difluoride (PVDF) composite and PVDF/VGCNF thermally sprayed with magnetite (Fe3O4) and graphite has been investigated. EMI SE evaluations were performed in the frequency range of 30 kHz-1.5 GHz. The developed nanocomposite (NC) system was fabricated by high shear mixing using a Banbury type mixer. The material was then subjected to compression molding. Subsequently, the films were thermally sprayed using Fe3O4/graphite powder. The NC and coated NC films had average thicknesses of 0.82 mm and 0.93 mm, respectively. The NC films were subjected …

Detection Of Microcystin Aerosol Particles, Alexis D. Dabney

Theses and Dissertations

Harmful Algal Blooms (HABs) are a growing global concern due to their increased prevalence and magnitude, frequency, and duration in affecting both aquatic ecosystems and human health (Brooks et al. 2015). In a series of experiments, lab-generated aerosol particles containing Microcystis and Microseira were captured using filters to analyze for concentrations of Microcystin, Saxitoxin, and Lyngbya toxins. The solutions were found to contain aerosols but did not contain detectable levels of Microcystin, Saxitoxin, and Lyngbya toxins following analysis by HPLC-MS. While the techniques for generating aerosols were shown to be effective, the generation and analysis of toxins did not produce …

Cities Of God Under Occupation: Settler Colonial Practices And Pacification In The Favelas Of Rio De Janeiro And The Occupied Palestinian Territories, Amanda Pimenta Da Silva

Theses and Dissertations

The 2002 film ‘City of God’ tells an anecdotal story of violence in the favelas of Rio de Janeiro, and is a reminder that the societies we tend to take for granted can actually be a luxury. The film portrays the daily life of the peripheries of Rio and its relation with drug trafficking, crime, and poverty, and how it has deteriorated into a war zone so dangerous that anyone risk being shot to death. Thousands of miles away from the Brazilian slums there is another so-called city of God, or the city chosen by God to be the home’s …

The Violence In Our Humanity: Principles, Action, And The Erosion Of State Sovereignty, Rasheed Idou

Theses and Dissertations

The past two decades have witnessed an increasing number of armed conflicts, both inter- and intra-nationally, and an even more increasing number of multilateral military interventions without UN Security Council authorization. Central to the discussion of these interventions are the themes of humanitarianism and state sovereignty. The aim of this thesis is to investigate the relationship between humanitarian imperatives and principles of sovereignty within the context of armed conflict to better understand the tensions that have led to the current global outcomes. In so doing, it identifies how humanitarian principles, imperatives, and actions have affected the contemporary conception of state …

Reconciliation, Restoration And Reconstruction Of A Conflict Ridden Country, Muhammad S. Riaz

Theses and Dissertations

Conflict has sadly been a constant part of history. Winning a conflict and making a lasting peace are often not the same thing. While a peace treaty ends a conflict and often dictates terms from the winners’ perspective, it may not create a lasting peace. Short of unconditional surrender, modern conflict ends with a negotiated cessation of hostilities. Such accords may have some initial reconstruction agreements, but Reconciliation, Restoration and Reconstruction (RRR) is a long term process. This study maintains that to achieve a lasting peace: 1) The culture and beliefs of the conflict nation must be continuously considered and …

A Model-Based Approach To Cubesat Propulsion And Payload Analysis, Madeline H. Johnson

Theses and Dissertations

Currently, there are only limited ways to increase mission success of CubeSats in terms of component and mission compatibility. The Payload Analysis Tool (PAT), developed by Air Force Institute of Technology (AFIT) students, combines the power of multiple tools to analyze payload compatibility on a single CubeSat bus. The PAT simulates a CubeSat mission with a variety of payloads to better understand how the payloads interact with the bus in terms of power, data rate, and memory, but it lacks a propulsion system. This thesis research advances the PAT by including a propulsion system which allows for increased mission time …

Experimental Characterization And Manufacture Of Polymer Nanocomposite Dielectric Coatings For High-Temperature Superconductor Applications, Jacob Ryan Mahon

Theses and Dissertations

Increased implementation of high-temperature superconducting (HTS) power transmission has the potential to revolutionize the efficiency of electrical grids and help unlock a fully electric transportation infrastructure. Realizing the benefits of HTS systems has been impeded by a lack of available dielectric insulation materials that can 1) withstand the extreme cryogenic operating environment of superconductors and 2) demonstrate low temperature processing that is compatible with existing superconductor manufacturing methods. Solving this problem necessitates a high-performance dielectric material with multifunctional properties specifically suited for operation in HTS systems. A polyamide and silicon dioxide (PA/SiO2) nanocomposite material with exceptional thermal stability has been …

“Infantry Would Not Do:” Appalachia, The Environment, And The Evolution Of Mountain Warfare During The American Civil War, Lucas Michael Wilder

Theses and Dissertations

Union General Ambrose E. Burnside launched his invasion of East Tennessee in the summer of 1863. The corps he used consisted of half-infantry and half-mounted units to utilize their speed to overcome mountain obstacles. The successful campaign and the capture of the agriculturally rich region of East Tennessee and its vital East Tennessee & Virginia Railroad deprived the Confederacy of resources, ultimately contributing to Confederate defeat. The American Civil War saw commanders plunge into the mountains of Appalachia and encounter a terrain and a people with which many were unacquainted. This dissertation argues that their tactics and strategies for dealing …

Design, Construction, And Characterization Of A Test Stand Used To Test Filter Media, Adam W. Parsons

Theses and Dissertations

Air filters are routinely used to remove various aerosols ranging from radioactive particles to airborne viruses. The overall performance of a filter may be simplified to consider only two main performance characteristics: 1) the efficiency at which particles are removed by the filter, and 2) the filter’s resistance to air flow. Per the DOE Nuclear Air Cleaning Handbook, HEPA filters require a minimum filter efficiency of 99.97% for particles 0.3 micrometers in diameter. Understanding how filters will perform with respect to time and mass loading is essential towards building more robust filters that operate more efficiently and safely. Analyzing the …

Detecting Cybersecurity And Behavioral Anomalies In Smart Grid Substation, Anfal Yahya Hathah

Theses and Dissertations

Due to the increasing number of cyberattacks on smart grid networks globally in the last decade, maintaining a stable electric power supply has become increasingly challenging. The shift from traditional means of measurement instrumentation to smarter devices in electrical substations is experiencing increasing incidents of intrusion. Defense against those intrusions is now a global trending research topic and is attracting governments’ attention. Various techniques have been developed to mitigate the effect of cyberattacks on national power grid systems. The state estimation technique has proven its capability in detecting random false data-injection attacks (FDIAs). However, attackers may have considerable knowledge of …

Holocene Human Influence In The Ecuadorean Amazon, Meghan Mary O'Connor

Theses and Dissertations

The extent to which the spectacular biodiversity of Amazonia has been shaped by Pre-Columbian humans is actively debated. Forests that today appear to be pristine wildernesses may have supported complex human societies as recently as 300 years ago. Understanding human history and the potential successional trajectories that result from site abandonment are important to conservation and policy-making. The Yasuni, is famed for its human and biological diversity and yet its pre-history is poorly known. Lake Añangucocha, a small blackwater lake in northwestern Ecuador, is unusual in that it is not a riverine lake, and has the potential to provide the …