ABOUT THE COLLECTION

The UA Master's Theses Collection provides open access to masters theses and reports produced at the University of Arizona, including theses submitted online from 2005-present and theses from 1895-2005 that were digitized from microfilm and print holdings, in addition to master's reports from the College of Architecture, Planning and Landscape Architecture from 1966 onwards. The collection includes hundreds of titles not available in ProQuest.

We have digitized the entire backfile of master's theses and doctoral dissertations that have been submitted to the University of Arizona Libraries - since 1895! If you can't find the item you want in the repository and would like to check its digitization status, please contact us.

The UA Master's Theses collection is not comprehensive; master's theses from 1993-2015 were only received and archived by the UA Library and ProQuest if the student chose to pay the optional archiving fee. The Library does not have copies of many master's theses submitted during this time period. Some academic departments may keep copies of theses submitted to their programs. Colleges and departments wishing to archive master's theses not available in the University Libraries are encouraged to contact us at repository@u.library.arizona.edu.

QUESTIONS?

Please refer to the Dissertations and Theses in the UA Libraries guide for more details about UA Theses and Dissertations, and to find materials that are not available online. Email repository@u.library.arizona.edu with your questions about UA Theses and Dissertations.


Recent Submissions

  • Cavitation and cavitation damage

    Rogers, W. L.; Wang, Shih-cheng, 1938- (The University of Arizona., 1965)
  • Monolithic Three-Mirror Anastigmat Telescope

    Kim, Daewook; Han, Yuqiao; Choi, Heejoo; Kupinski, Meredith (The University of Arizona., 2023)
    This thesis presents the design of a near-infrared (near-IR) three-mirror anastigmat telescope with a focal length of 38,675.1 ??, an entrance pupil diameter of 1,933.75 ??, and a 0.12° full field-of-view (FoV). This diffraction-limited telescope has a RMS spot radius of 36.6 μm (similar to the radius of Airy disk) to satisfy the design resolution requirements of the IR telescope. Designed specifically for near-IR sensing, the system benchmarked a widely known module of an IR detector, called the Near-Infrared Camera (NIRCam) detector, with ten Teledyne HgCdTe H2RG detectors. The NIRCam detector was assumed in this TMA design study, similar to the James Webb Space Telescope case. This three-mirror telescope design contains only two substrates, one consisting of two mirror surfaces with different radii of curvature. Consequently, the structure of this robust telescope design is straightforward and it is therefore easy to manufacture and align. The starting point for the optical design of this telescope was the Vera C. Rubin Observatory (a.k.a. Large Synoptic Survey Telescope), a three-mirror anastigmat system combined with more refractive lenses and a color filters. Importantly, the specifications of these three mirrors were changed to achieve the goal of aberration balancing. To determine the tolerances of the optical design, the M2 mirror substrate was misaligned with respect to the M1/M3 monolithic mirror, and the realistic maximum error was evaluated. As a result, in the range of 36.6 ?? root mean square (RMS) spot radius for the three degrees of freedom (DoF), the calculated tolerances were 0.0072° for X-rotation, 43 µ? for Y-translation, and 7.6 µ? for Z-translation. This result confirmed that the required machining accuracy to build the proposed telescope is within the advanced optical fabrication (e.g., diamond turning) and modern integration capabilities.
  • Efficacy of Chlorine and Peracetic Acid to Reduce Shiga Toxin-Producing Escherichia Coli and Impact of Simultaneous Nitrogen-Based Fertilizer Use on Microbial Die-Off in Preharvest Agricultural Water

    Rock, Channah; Scott, Zoe; Cooper, Kerry; Gerba, Charles (The University of Arizona., 2023)
    Several foodborne disease outbreaks in the United States have been linked to the consumption of various types of leafy greens in which irrigation water was suspected as the potential source of contamination. To reduce potential produce contamination from agricultural water, the U.S. Food and Drug Administration (FDA) has proposed regulations/metrics which would require growers to assess their agricultural water systems. In some cases, this would mean monitoring their water quality and taking corrective action, by way of antimicrobial treatments, when agricultural waters are deemed as a “reasonably likely foreseeable hazard”. Additionally, the Arizona and California Leafy Greens Marketing Agreements (AZ/CA LGMA) require growers utilizing surface water for overhead irrigation to treat their water within 21 days of harvest to meet acceptable risk indicators; generic Escherichia coli (E. coli) (non-detect per 100mL) and Total Coliform bacteria (<99 MPN/100mL). For many growers, this will be the first time that water quality data may necessitate them to use an antimicrobial treatment before irrigation can be applied safely. Additionally, growers are faced with a myriad of options related to antimicrobial water treatment with very little guidance on the most appropriate treatment option for their ranch, or the requirements needed for successful implementation. With limited guidance, water treatment decisions are likely to be unsuccessful and expend both excess time and money while seeing little to no reduction in potential pathogen loading in an agricultural water source and thus little to no reduction in microbiological risk. To provide guidance on antimicrobial agricultural water treatment options available to industry, the efficacy of two antimicrobial treatments Peroxyacetic Acid (PAA) and Calcium Hypochlorite (Cl) were tested, in triplicate. Tests were executed for various rates of each antimicrobial product (sanitizer), 6 & 8 PPM for PAA and 2 & 4 PPM for Cl. For each sanitizer at each PPM, tests were conducted at temperatures 12°C and 32°C. To evaluate sanitization efficacy, the team measured the reduction of a 109 CFU/mL cocktail of Shiga toxin-producing E. coli (STEC) strains (ATCC MP-9 and 43895) in four water sources from across the southwestern United States (Yuma and Maricopa, AZ, Uvalde and Edinburgh, TX). Four different water sources were used to gauge if water quality impacted sanitization efficacy. The experimental design was based on an EPA/FDA protocol to assess the efficacy of an antimicrobial product to reduce foodborne bacteria in pre-harvest agricultural water (https://www.fda.gov/media/140640/download) . This protocol dictates that STEC cocktail be added to agricultural water then equilibrated at either temperature (12°C or 32°C); post equilibration, each sanitizer, for each concentration, is injected into the mixed solution. The appointed contact time (1 or 5 minutes) is given and then the solution is neutralized and evaluated. To further growers’ comprehension of best management practices for successful antimicrobial treatment application, the impact of two nitrogen-based fertilizers (UAN32 and CAN17) on the efficacy of Sodium Hypochlorite 6% (chlorine) and PAA against naturally occurring coliforms was also evaluated. The first study provides evidence that chlorine meets EPA’s required 3-log reduction of pathogens in order to receive label approval. At a one-minute contact time, the chlorine treatment resulted in log reduction values (LRVs) ranging from 3.24 to 6.15 regardless of temperature, dose/PPM, or water source. PAA however did not perform as well with LRVs ranged from 0.0 to 1.10 with higher reduction occurring at the higher temperature and dose of PAA. When the contact time of PAA treatment was increased to five minutes, LRVs increased and ranges from 1.5 to 5.4 were observed; the efficacy of the sanitizer increased with increased solution temperature. Furthermore, the addition of nitrogen-based fertilizer to the water source in tandem with treatment application significantly affected the antimicrobial capabilities of chlorine. For chlorine, when applied unaccompanied an average log reduction of 3 logs was seen. However, LRVs decreased on average by 1.34 logs when fertilizer was introduced: with the greatest reduction in efficacy resulting in a nearly 2-log decrease. Contrarily, combined application of PAA and either fertilizer showed little to no interaction with a 0.4 log increase in disinfection efficacy when UAN32 was used. Results indicate that a prolonged contact time may be needed to meet regulations when PAA is used as an antimicrobial treatment. As well, growers must be cautious when applying fertilizer conjointly with antimicrobial treatment to their agricultural waters to ensure compliance with new proposed food safety metrics.
  • Structural and Diffusion MRI to Study the Effects of Hypertension in Rat Brain Macrostructure and Microstructure

    Trouard, Theodore; Wiskoski, Haley Elizabeth; Hutchinson, Elizabeth; Chen, Nan-kuei (The University of Arizona., 2023)
    Hypertension (HTN) is associated with an increased risk of cardiovascular disease (CVD) and cognitive decline in aging humans, with onset occurring around middle age, and responsible for roughly 7 million deaths worldwide, annually. Prior research has also shown that mid-life HTN is associated with negative effects on brain structure and function in late life. Therefore, it is important to study the symptoms of HTN on the central nervous system as the disease progresses with age, and specifically how this may affect neurological anatomy, development, and function. Animal models are an integral tool in preclinical, translational research of the human body, facilitating greater understanding, treatment, and prevention of diseases such as HTN. The Fischer-344 Cyp1a1-Ren2 transgenic xenobiotic-inducible rat model is an appreciable strain in studies of HTN due to the fact that the induction of increased blood pressure, as induced via the administration of dietary molecule Indole-3-Carbinol (I3C), is reversible, controllable, and dose-dependent in magnitude. The purpose of this study was to investigate the longitudinal effects of induced HTN in macrostructural and microstructural neuroanatomy of F344 Cyp1a1-Ren2 transgenic rats through the use of noninvasive diffusion-weighted MRI (dMRI) and imaging analyses. Results of this study show that even in the face of sustained increases in blood pressure and end-organ damage in the heart and kidney, a majority of the brain remained unaffected in terms of volume and microstructural characteristics. This indicates the presence of an intrinsic, protective mechanism of the brain in this model, forestalling the onset of detrimental effects of HTN on brain structure and function.
  • Gender Identity and Expression in Drum Corps Performance: An Ethnographic Study of Performers' Experiences

    Gubner, Jennie; Frew, Johnathan; Alexander, Kathryn; Mora, Amalia (The University of Arizona., 2023)
    This project seeks to understand how gender is constructed, performed, and experienced through participation in drum corps. Drum corps is a North American youth performing arts practice in which musicians and dancers perform themed marching band shows throughout the United States and are judged competitively against one another. The data used in this project comes from four weeks of ethnographic fieldwork with the Blue Knights drum corps during the summer of 2022. Personal accounts from the corps’ members and staff, fieldwork photographs, and the author’s observations are analyzed in this project to explore performers’ experiences with gender in drum corps.
  • Parametric Urban Analysis & Design: Integrating Flood Risk Mitigation Strategies, Socioeconomic and Industrial Heritage Priorities in the Gowanus Canal Area

    Weinstein, Beth; Florentino, Felipe Rodrigues; Dickinson, Susannah; Silver, Michael (The University of Arizona., 2022)
    The threat of climate change, sea level rise, and the increasing risk of flooding is a severe challenge to coastal cities worldwide. The Gowanus Canal Neighborhood, located in New York City, is also among the places facing this issue and was investigated in this research. In addition to climate change, a second issue investigated that is poised to have an increasingly significant influence on the Gowanus Canal's future is the impending rezoning of this area by New York City's Department of City Planning.With substantial vacant or underused properties, of which a significant number of those have historic industrial characteristics, rising demand and value of housing, and the ever-present pressure of development, residents, stakeholders, and city officials have been engaging in a conversation together about how the land surrounding the Gowanus Canal should be used in the future. They consider that the neighborhood's existing socioeconomic, historical, and demographic context has been generally ignored at the expense of purely infrastructure solutions. In recent years, community planning initiatives were undertaken. The city's planning department has since begun the formal process of considering the results of this planning process in formulating a new zoning framework for the neighborhood. The outcomes of this process will dictate land use policies for the foreseeable future. To address this oversight and develop strategies that address all the above subjects, this research investigated how parametric tools, generally used for developing projects on an isolated lot and parcel scale or for creating masterplans in uninhabited areas, could be explored in already developed areas. Specifically, the research tested how the parametric interaction could generate a zoning that more adequately meets community's expectations in line with the environmental challenges in the Gowanus Canal area. Two sites with similar characteristics to the Gowanus Canal, both environmental, social, and economic, were studied. In addition, two studies addressing parametric tools' efficiency in developing strategies to mitigate the harmful effects caused by floods were investigated. Then, different parametric tools were tested to select the most accurate for the specific data types related to the site of Gowanus Canal. The research collected qualitative data, such as the community’s desire to create safer streets and improved access to employment opportunities, and quantitative data including topography and sea level rise indexes, of the Gowanus area. These were overlapped and compared, brought into a parametric model, to generate, through parametric analysis and simulations, proposals for a new zoning with resilient strategies optimizing responses to the existing challenges in the Gowanus Canal area. In the final stage of the work's development, it was revealed that the scale of the analysis of the Gowanus Canal was overly complex, both in terms of the number of social and economic factors, as well as in environmental aspects; for a better response from the parametric software yielding a proposal for coherent zoning, reducing the scale of the analysis was necessary—closer to parcel than district scale. For this, a perimeter was delimited in the center of the neighborhood. The reduction of the research area significantly improved control of the data inserted in the parameterization programs. After several iterations, a divergence in the parametric model’s functionality was noticed concerning the insertion of qualitative data. Its privileging the quantitative, to obtain more precise models for viable zoning the parameterization of qualitative was set aside for the benefit of the project. In conclusion, the research revealed both potentials of recent innovations in parametric software research and limitations of these; they currently are limited in their capacity to integrate qualitative (i.e., flooding, street pattern) data with quantitative data (social goals and heritage priorities). Furthermore, the Gowanus Canal, as a developed area full of infrastructure and which faces challenges related to sea level rise, served as a concrete site of inquiry to test the limits of parametric research applied to complex urban areas. Finally, the significance of this research is that it has revealed the need to further develop qualitative data translation methods and parameterization tools to allow the analysis and synthesis of contrasting types of complex data, such as social factors, to generate resilient and socially responsible projects in urban areas.
  • Investigating Symbiotic Microbial Community Variation Across Different Genotypes

    Hackett, Jeremiah; Bowers, Hailey; Enard, David; Thompson, Diane (The University of Arizona., 2022)
    Understanding the roles and relationships within the coral microbiome may further help scientists understand coral’s resilience to climate change. Previous studies have examined the coral microbiome to delineate coral microbial communities (Meyer et al., 2014; Hernandez-Agreda et al., 2017; Kellogg & Pratte, 2021). Further, scholars have previously identified species-specific associations within the coral microbiome (Ritchie & Smith, 1997; Koren & Rosenberg, 2006; Carlos et al., 2013; Hernandez-Agreda et al., 2017). However, a gap in the literature exists examining the genotypic variation within one species while controlling for abiotic factors. This study hypothesizes that genotype may play a significant role in microbiome diversity by investigating the microbial communities of five different genotypes of Porites astreoides maintained at Biosphere 2. While controlling for abiotic factors, various bioinformatics techniques through QIIME2 identified the taxonomic composition of each sample’s microbiome and Alpha and Beta Diversity metrics. Alpha and Beta Diversity metrics produced no statistically significant results when testing the relationship between genotype and microbial community. This study suggests that external abiotic factors may significantly impact a coral’s microbiome composition more than its genotype. Alternatively, individual species may show a high degree of specificity in their microbial associations among individuals and environments, with proximity among individuals of a species playing a first-order role in the differences in microbial community.
  • Dido: Queen of Carthage

    Groves, Robert; Minson, Sarah; McCallum, Sarah; Park, Arum (The University of Arizona., 2022)
    In this thesis project, I partake in classical reception and write an alternate story of the life of Dido, the mythical founder and Queen of Carthage. I interact with sources such as Virgil’s Aeneid and Justin’s Epitome of the Philippic History of Pompeius Trogus. I include the first and last chapter of this novel, as well as a detailed outline of the events of the chapters in-between. Each chapter is followed by a detailed commentary of the way in which I interact with the ancient sources, as well as my analysis of the themes I incorporate throughout – for example feminism and female agency. In my introduction I explain my intentions with the piece, as well as detailing the process of writing a piece of reception and analyzing other pieces which I have drawn inspiration from.
  • Oxytocin and Aggression in Verreaux's Sifaka (Propithecus verreauxi) in Kirindy Mitea National Park, Madagascar

    Tecot, Stacey R.; Liu, Arielle Xiaofen; Lewis, Rebecca J.; MacLean, Evan L.; Papaj, Daniel R. (The University of Arizona., 2022)
    Many species, particularly group-living species, display aggression. To help understand the biological basis of aggression, aggression is often analyzed with hormonal biomarker levels, but this usually occurs in highly aggressive species. Therefore, we know little of the patterns of aggression and its hormonal mechanisms in low-aggression species. Aggressive behaviors in such species may serve different functions or occur through different mechanisms. The goal of this study is to examine intragroup aggression in male and female P. verreauxi, a low-aggression species with female power over males. Aggression may be inhibited by higher levels of oxytocin (OT), so I examine the relationship between aggression and OT in males and hypothesize that they are negatively associated. I explore aggression patterns in male and female P. verreauxi using data from January 2007 to December 2019. We use enzyme-linked immunosorbent assays (ELISAs) to determine OT levels in male urine samples from July 2018 and January through March 2019. I found that females had higher rates of aggression than males, that most aggression occurred during the mating season, and that males received the most aggression from females while females received the most aggression from males during the mating season. Also, male OT levels were lower during the mating season compared to the non-mating season. Contrary to expectations, aggression rate was not a significant predictor of male OT levels, though they showed inverse seasonal patterns. The results of this study support previous research indicating that aggression is one means of achieving female power over males and suggest that male OT levels are not directly related to intragroup aggression. However, future research should explore whether OT levels are associated with intergroup rather than intragroup aggression.
  • A Modular SPECT Camera Combining PMTs and SiPMs

    Furenlid, Lars R.; Doty, Kimberly Jolene; Kupinski, Matthew A.; Gmitro, Arthur F. (The University of Arizona., 2022)
    In this work, novel modular gamma camera concepts for SPECT imaging systems were investigated. The camera designs included curved scintillation crystal to address parallax errors and 3D position resolution In addition, fiber optics plates as a light guides to transfer scintillation light from the curved exit face of the scintillation crystal to the planar light sensors for readout. The estimated intrinsic spatial resolution of the cameras averaged over the detector volumes were used as the figures of merit for comparisons. Spatial resolution was estimated using the Cramér-Rao lower bound condition from Fisher Information Matrices. The components of the Fisher Information Matrices were derived under an assumption of Poisson statistics by finding mean detector response function using a custom Monte-Carlo photon transport code written in Swift and Metal. All the designs were candidates for the AdaptiSPECT-C system, and ultimately a camera design using a hybrid combination of silicon photomultipliers and photomultiplier tubes balanced cost and performance goals for this system. The addition of curvature into modular gamma cameras did not significantly change the intrinsic spatial resolution of the cameras but does improve the point spread function for oblique rays from a single pinhole collimator. The addition of fiber optic plates as light guides does offer a path to improved 3D positioning that is worth exploring with a prototype camera and point-spread-function measurements.
  • Oxytocin and Affiliative Behavior in Male P. Verreauxi at Kirindy Mitea National Park, Madagascar

    Tecot, Stacey; King, Katherine; MacLean, Evan; Lewis, Rebecca J. (The University of Arizona., 2022)
    Though social behavior is widespread in primates, patterns and drivers of affiliation are not well understood, especially in males and strepsirrhine species. Recent studies have identified the role of oxytocin, a neuropeptide involved in maternal and pair-bonding behaviors, in general affiliation. However, these studies have exclusively used haplorrhine species and primarily rely on laboratory or captive work. Here, we use wild male Verreaux’s sifaka (P. verreauxi), a group living lemur species with opposite and same-sex affiliative behaviors, to investigate the association between oxytocin (OT) and affiliative behavior. We collected behavioral data and urine samples from individually marked Verreaux's sifaka in Kirindy Mitea National Park, Madagascar between 2018 and 2019. In the Laboratory for the Evolutionary Endocrinology of Primates (LEEP) we used ELISA Arbor Assays OT kits to conduct urinary OT analysis on 127 samples. We compared behavior, OT concentrations, and the relationship between the two across two seasons: mating and non-mating. We found that OT is higher in the non-mating season, while affiliative behaviors are more frequently observed in the mating season. In the non-mating season, there was a significant negative association between OT and affiliative behavior. Our results demonstrate seasonal patterns of both OT and affiliative behavior and a lack of association between these two variables, suggesting further investigation of the understudied roles of OT across seasons, and other potential hormonal mechanisms for seasonal differences in behavior.
  • Evaluation of Ancient Fengshui Principles and their Impact on Layouts of Contemporary Residences for Human Health

    Engineer, Altaf; Rui, Chumei; Schrenk, Lisa D.; Yang, Bo (The University of Arizona., 2022)
    Architectural Fengshui is a living guideline that the ancients developed and adopted to live a comfortable life. Architectural Fengshui expresses the “unity of heaven and earth” concept through the structural features of mountains surrounded by water and the accumulation of wind and air, and this concept is linked to the core idea of how ancient people perceived and interacted with nature. Fengshui and Traditional Chinese medicine (TCM) has a close relationship, both of which are derived from the “The I Ching (Book of Changes),” so the theoretical basis of Fengshui is the same as that of TCM. However, due to the complexity of Fengshui and the limitations of people’s knowledge, the dualities of mystery and superstition are blended with Fengshui in the West, and the scientific nature of Fengshui theory has been questioned and challenged by Western scholars. This thesis combines the Five Elements and Eight Trigrams with TCM theory to examine how Fengshui principles apply to the layout design of contemporary residences and their impact on human health. The analysis of the courtyard house and how Fengshui principles were applied provides a preliminary assessment of the reasonability and objectivity of Fengshui in architectural layout design. The thesis also examines the relationship between people’s health and the spatial layout of their homes through questionnaires, verifies and analyzes how Fengshui in residential layout affects people’s health, and then discusses how the practice of Fengshui can help create a residential environment that promotes good health and well-being. Research reveals that the Five Elements and Eight Trigrams in Fengshui theory have specific references in residential layout design, and poor spatial layout would impact human health.
  • Crossflow On A Sharp 7 Degree Cone At Mach 5 At A 6 Degree Angle Of Attack

    Craig, Stuart A.; Padilla, Victor Emmanuel; Little, Jesse C.; Threadgill, James A. (The University of Arizona., 2022)
    Experiments were performed on a 7 degree sharp cone at 6 degree angle of attack in the University of Arizona Mach 5 Ludwieg Tube (LT5) aimed at exploring the breakdown of crossflow vortices. A Torlon sharp tip with discrete roughness elements (DREs) was manufactured and utilized to excite stationary waves associated with the crossflow instability while attenuating traveling waves. The campaign was administered to establish a foundation for crossflow research at the University of Arizona, and to observe the crossflow secondary instabilities that lead to breakdown at a hypersonic Mach number of 5. Transducers onboard the cone and infrared (IR) thermography were the tools used to record findings. Black matte 3M Wrap Film Series 2080 was applied to the cone's main frustum to facilitate IR measurements, which were recorded with a FLIR X8501sc middle wavelength infrared (MWIR) camera. Measurements by the IR camera were calibrated using constants converting radiance captured by the camera to temperature. These temperatures are then converted to heat flux. PCB 132B38 and Kulite XCE-062-20A transducers were used to record fluctuating pressures which were then converted to the frequency domain using the fast Fourier transform, and then the power spectral density (PSD) is calculated using Welch's method. Eleven PCBs were installed along with two Kulites. Two clusters of 4 PCBs and 1 Kulite were employed to measure traveling waves. The PSD of the PCBs showed peaks of possible secondary-instabilities and the second mode.
  • Commercial Networks and Marks of Trade on Athenian Pots

    Hasaki, Eleni; Smith, Cole Matthew; Blake, Emma; Soren, David; Lawall, Mark (The University of Arizona., 2022)
    The study of Athenian vase trade presents several complexities and can be better approached through a variety of perspectives aimed to understand equally the roles of its key actors: potters, painters, traders, and consumers. The entire spectrum of mechanisms involved in the pottery trade is not fully apparent, and the decision-making of middlemen/traders typically remains particularly obscure to scholars (Gill 2009; Bundrick 2019). The markings found on the bottom of primarily Attic figured pots from the 6th through 4th centuries BCE, termed trademarks, could provide therefore a crucial dataset for enriching our understanding of how trade occurred during this period. The trademarks, meticulously collected and classified by Alan W. Johnston, have been underutilized. The present thesis aims to dig deeper and to approach this untapped resource more systematically through statistical and network analysis, in order to underscore the importance of the trademarks for analyzing the nuances of the Attic vase trade. The trademarks can encourage scholars to further examine the interconnections between pottery workshops and producers, and traders, and evaluate better the complex and geographically- varied consumer bases across the Mediterranean and beyond.I used, as a proxy, an updated and expanded dataset I built from Johnston’s Trademarks on Greek Vases: Addenda (2006). The updated dataset of 3100 entries represents 147 types of trademarks, over 250 artists and 97 distinct destinations, mostly in Italy but also throughout the Mediterranean from the Black Sea to Spain. I ran the first-ever set of statistics for techniques, shapes, and destinations, extracting thus the most information from this rich dataset. On a more advanced level of analysis, I employed social network visualizations to investigate the relationships of painters, trademarks, and destinations. With focused analyses on the cities and artists with the most trademarks and with time-sliced network graphs for the period from 600-300 BCE, I also explored both the extent of a pot-marking system, how it functioned, and how it changed over time. The network analysis helped establish a fuller picture of the interconnection present between traders, producers, and consumers, through the intentionality of mark placement on specific pots for export. Through the study of these systematic marking systems, I highlight the important role of traders and their mechanisms, the mercantile savviness of the producers in their pottery workshops, and the market impact of consumer choices.
  • Intravital Two-Photon Microscopy and the Glymphatic System: Settling the Bulk Flow Debate

    Hutchinson, Elizabeth; Samoy-Alvarado, Alexander Joseph; Utzinger, Urs; Sawyer, Travis (The University of Arizona., 2022)
    The glymphatic system, also known as the paravascular system, is a recently discovered physiological pathway that clears wastes and metabolites from the brain via flow of cerebrospinal fluid (CSF) and interstitial fluid (ISF). The nature of the driving force behind CSF and ISF flow is a hot topic of debate, as some groups suggest there is bulk flow driven by arterial pulsations and/or vis a tergo CSF production from the chorid plexus, and other groups postulate diffusion or dispersion occurs in the absence of bulk flow. In vivo observation of the paravascular system is particularly challenging to accomplish and usually involves injection of fluorophores directly into the Cisterna Magna or into the interstitial space so fluorescence microscopy can take place. Opponents of this method of dye delivery state that direct injection affects intracranial pressure and disrupts the natural fluid dynamics of the system. The work conducted in this thesis introduces a new paradigm of dye delivery via focus ultrasound mediated blood brain barrier disruption, which allows the fluid dynamics of the glymphatic system to be observed undisrupted using intravital two-photon microscopy. Preliminary analysis of the images suggests that bulk flow is not present at a depth of approximately 60-120 microns from the surface of the cortex and that diffusion is the major driving force in the paravascular system. Further work needs to be done in order to support this claim enough to reject the bulk flow hypothesis at all depths of the brain.
  • Improving Extractive Summaries through Abstractive Transformers

    Surdeanu, Mihai; Kreso, Marko; Bethard, Steven; Blanco, Eduardo (The University of Arizona., 2022)
    This paper focuses on using a novel unsupervised summarization layer, called BART-textrank, that uses both abstractive and extractive techniques to produce a final extractive summary. This unsupervised layer is versatile since it can be added on top of any abstractive summarizer without additional training. It is used in conjunction with a base size transformer that achieves SOTA performance in a few metrics when comparing to transformer methods with similar parameter size, and remains competitive with large transformers. The competitiveness of BART-textrank is apparent in figure 4.2.
  • Glycolipid Surfactants as Chemical Precipitants for Metal Remediation

    Hogan, David E.; Maier, Raina M.; McCawley, Ida Ann; Chorover, Jon; Curry, Joan E. (The University of Arizona., 2022)
    The expansion of low carbon technologies such as solar power, electric vehicles, and wind turbines has increased demand of critical elements such as rare earth elements (REEs). Hardrock mining produces 99% of the REE supply, but mining is environmentally costly; therefore, it is essential to examine nontraditional production methods. Identifying and exploiting cost-effective and green methods of metal recovery from natural and contaminated aqueous systems is widely recognized as necessary to supplement the supply of critical elements, decrease the environmental impacts associated with hardrock mining, and remediate metal-contaminated waters. The objective of this research is to examine a novel approach based on glycolipid-facilitated chemical precipitation of metals and REEs. Three techniques were assessed to remove the glycolipid:metal complex from solution: mixing only, and mixing followed by filtration or centrifugation. Recent advancements in the ability to synthetically produce glycolipid surfactants has allowed for the investigation of a variety of glycolipid structures. Sixteen glycolipids were assessed to determine the effect of structure on the molecule’s ability to chemically precipitate Pb2+, La3+, and Mg2+ from single metal solutions. It was determined that under certain conditionsmetals can be removed by the addition of a glycolipid only, but the addition of an active removal step (filtration or centrifugation) greatly improved the removal of the metals. Results suggest tailoring the glycolipid structure and removal methods may enable selective metal removal to achieve specific outcomes. Future studies in mixed-metal and real-world solutions will be needed to confirm the viability of these techniques in complex systems. Aqueous mining will likely be increasingly important in the mining industry, but additional research and technological innovation are needed to further develop it into an effective tool to meet industrial demands.
  • Visualization of Verification Information Throughout The System Lifecycle Using a Model-Based Tool

    Salado, Alejandro; Thrower, Ashley; Valerdi, Ricardo; Lepore, Robert (The University of Arizona., 2022)
    The continual increase of system complexity in industry has demanded more innovative ways to handle its organization and development. One organizational component that can be easily mishandled is that of verification. Without streamlined or highly visible verification and validation, miscommunication can arise between the involved parties such as the client, the systems engineer, the test engineers, and the other engineering groups involved in the design and fabrication of the product. This thesis leverages the shift towards model-based environments to produce a verification framework to be implemented within the Model-Based Systems Engineering field. The framework is implemented in a modeling tool to produce an information view capturing detailed verification information from element coupling. Using object-oriented design pattern considerations, this approach supports the evolution towards model-centric environments in industry and adaptation for differing verification strategies. It encourages early implementation of verification in the system development lifecycle and can be the starting point for a standard model-based verification information output. This structure enhances visibility of information across all involved parties and allows for growth when integrated with a system architecture model and additional digital environment artifacts. As a foundation, this visibility enhanced representation may be combined with other verification strategies to enable automation and/or optimization of a system’s design.
  • Pointing Angle Characterization of Optical Axes in a Multi-Camera System

    Chalifoux, Brandon D.; Dominguez, Daniel; Liang, Rongguang; Kim, Daewook (The University of Arizona., 2022)
    Geometric camera calibration is critical for many Computer Vision applications. This process characterizes intrinsic and extrinsic parameters of the camera. Intrinsic parameters typically include the camera’s center point and focal length. Extrinsic parameters describe the orientation of the camera with respect to a common coordinate system. A common method, developed by Zhang, computes these parameters given multiple poses of a dimensionally-known calibration target; using an optimization algorithm to transform the target’s 3D world points to the corresponding 2D points imaged on the camera sensor (Zhang, 1998). In this report, the author proposes an alternative method for computing camera pointing angle (rotational extrinsic parameters Rx/Ry) which strives to serve as a ground-truth for systems requiring accuracy less than 2 arcmin (2σ). Dubbed the Camera Centration Method, this approach utilizes a collimated light source whose beam is split and redirected in a predictable manner to each camera of a Multi-Camera-System (MCS). The common light source and known beam path serve as a bridge to identify the position of each camera with respect to the other. Given each camera’s intrinsic parameters, its orientation with respect to the incoming collimated laser source, and the sensor pixel activated by that source, the author shows that one can compute camera pointing angle of the left and right cameras with respect to the center. The proposed method is finally estimated to have a measurement uncertainty of 5.85 arcmin, an order of magnitude larger than the desired 0.1 – 0.25 arcmin uncertainty. In the Discussion Section, the author recommends improvements, which are outside the scope of this project, that reduce the estimated measurement uncertainty to 2.33 arcmin according to a first-order analysis. While the Camera Centration Method cannot replace the Zhang Method, the author concludes that it has the potential to serve as a ground truth for extrinsic rotation parameters, Rx/Ry, where the system accuracy spec is greater than ±46 arcmin (2σ).

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