Browsing Master's Theses by Title
Now showing items 1-20 of 15822
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1-D Rans Model Optimization for Turbulent Richtmyer-Meshkov Instability Experiments in the University of Arizona Vertical Shock TubeIn this study, a comparison of experimental and computational results for the Richtmyer-Meshkov instability in a shock tube at the University of Arizona with a diffuse interface is carried out. Two turbulence models, the K-L-a and K-L-a-V models, are used to obtain the computational data using 1D simulations. The models are optimized for a new set of membraneless experiments performed in the University of Arizona vertical shock tube. The varied parameters are L_0, the initial turbulent length scale, and α_b, the Rayleigh-Taylor bubble growth parameter. One parameter, the Richtmyer-Meshkov growth exponent θ, was adjusted from a value of 0.25 to 0.5 to match the experimental setup. The experiments used to calibrate these models used membranes to initially separate the two gases in the shock tube. The presence of a membrane affects the development of the fluid instability and turbulence. However, the model has an option to model a diffuse interface. It was therefore desired to determine if this model can accurately model the membraneless experiments by utilizing this diffuse interface modeling. Many different optimization parameter pairs were tested and the goodness of fit to the experimental data was calculated. The diagnostic metrics used to evaluate the goodness of fit were the width of the turbulent mixing region and the turbulent kinetic energy (TKE) over time. Experimental data with both high and low amplitude initial perturbations were used. The best fits for each of these metrics are presented. It was found that the parameters that provided the best fits for these experiments did not match the model defaults. When α_b is not changed from its default value of 0.06, it was found that the model fits the data well before reshock, but overpredicts the post-reshock growth of both mixed width and TKE. Better fits were found when α_b was able to vary over a range of [0.02,0.06] and L_0 was varied as well. For the best fits, the values of α_b were not the same for the high and low amplitude cases. The best fit values of α_b did agree when comparing mixed width and TKE in the high amplitude case, but not for the low amplitude case. A value of α_b=0.025 was found to work for all metrics fairly well. Although this did not provide the best fit overall, it did provide a reasonable fit for both the low and high amplitude cases. It should be, however, expected that there is a relationship between α_b and the amplitude of the initial perturbation.
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1. Mechanistic studies on the formation of glycosyl iodides 2. Synthesis of amino sugars via glycosyl iodidesThe synthesis of oligosaccharides remains a challenging task. In our studies, we applied glycosyl iodides to the synthesis of oligosaccharides. The mechanism of formation of glycosyl iodides from anomeric acetates of glucose, galactose and mannose, and 1,2 and 1,6 anhydro sugars were investigated by NMR. Glycosyl iodides were then applied in glycosidation studies and specifically in the synthesis of a precursor to the trisaccharide of Lewis x, a blood group antigen.
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13C and 37Cl characterization of PCE and application to contamination of the Harrison Landfill: Tucson, ArizonaTetrachloroethene (PCE) contamination of groundwater and soil air underneath Harrison Landfill in Tucson, Arizona, likely occurred by downward vapor phase transport of PCE dumped in the landfill. This study has explored the possibility of using isotopic techniques to better understand this process. The author designed and used a technique for the extraction of PCE vapors from soil air, for 6 13C and 637C1 analysis. It involved collecting PCE vapors by passing soil air through PCE adsorbent traps, then processing and transferring the PCE to a combustion tube. The author also measured for 6 13C and 637C1 values from manufactured trichloroethene (TCE, same as measured by another lab) and PCE samples. An additional experiment measured the 6 13C and 837C1 values of the liquid PCE residual after evaporating various fractions of PCE. 8 13C and 837Cl values of the TCE samples previously described were similar to the earlier values, indicating that 8 13C and 637C1 measurements of solvents (including PCE) were reproducible. Successive evaporation of PCE followed a Rayleigh trend, indicating a values of 1.0006 for carbon and 0.9992 for chlorine. The author simulated the PCE soil vapor sampling in the laboratory, achieving high yields and good separation of PCE. 8 13C values from Harrison soil PCE vapors ranged from — 27.3 to —25.1 0/00 and were within previous values for PCE. 637C1 values were at least 2.3 0/00 higher than any previously reported for PCE samples. 637C1 values for PCE, indicated that either the PCE in Harrison landfill became fractionated in situ, or was already 37C1 rich when dumped at the site.
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The 1889 and 1900 Paris Universal Expositions: French masculine nationalism and the American responseUniversal expositions of the later nineteenth century were opportunities for the host country to reinforce its sense of nationalism and to showcase its technological progress or, read differently, the progress of man. This thesis examines nationhood as defined in terms of masculinity at the 1889 Paris Universal Exposition, which demonstrated French technological, colonial, and artistic superiority over all other nations. This superiority was trumpeted not just through architecture and colonial exhibits, but also through criticism of other countries' artwork, particularly painting and sculpture from the United States. Also discussed is the reaction of American artists to the criticism received in 1889 by producing art at the 1900 Paris Universal Exposition that resonated with masculinity, thereby projecting an enhanced national identity in fine art.
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1990 Spousal rape occurrenceThe purpose of this study was to (1) determine the number of Spousal Rapes reported to law enforcement agencies of the Tucson Metropolitan Area during 1990, (2) measure expert perceptions regarding the occurrence of Spousal Rape in the Tucson Metropolitan Area during 1990, (3) compare official reports and expert perceptions regarding the occurrence of Spousal Rape, and (4) determine what experts believe to cause under-reporting, if found. The population for this study consisted of 30 experts working with victims of spousal rape. These experts were from 4 categories: human service workers, therapists, attorneys, and researchers. Thirteen spousal rape reports were received by law enforcement agencies in the Tucson Metropolitan Area. Experts believed that spousal rape occurrence was 10-2500 times higher than the number reported. Most reasons for under-reported that were shared by experts pertained to low public awareness regarding the causes for spousal rape. Also presented are conclusions, recommendations, and implications.
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2 X 2 Monolithic Mirror Camera Design for MID-IRThis paper presents the design of a mid-infrared (mid-IR) 2 × 2 monolithic mirror camerahaving an entrance pupil diameter of 259 ??, a focal length of 537.253 ??, and a 1° field-of-view (FoV). This camera shows optical performance with 15 ?? spot radius of the given FoV requirements for IR array of detectors (30 ?? pixel pitch). Specifically designed for mid-IR sensing, the camera uses an IR detector with a quantum interband cascade structure of InAs/GaSb type-II superlattice (T2SL) materials, which was developed at the physics laboratory of Chonnam National University in South Korea This camera design contained only two monolithic mirrors, one consisting of two surfaces with different radius of curvature. Therefore, this design has a compact and simple structure; hence, easy to manufacture, test, and align. The optical design for the camera inspired by the Vera C. Rubin Observatory’s Large Synoptic Survey Telescope (LSST), an improved Paul-Baker three-mirror system with three refractive lenses and a color filter. Considering the need to add cooling and signal processing equipment behind the detector, we decided to modify the design to add a quaternary mirror instead of the camera lenses. To determine tolerances, M2/M4 mirror substrate was misaligned, and the direction of maximum error was measured. As a result, in the range of 30 ?? RMS spot radius for the three DoF, the calculated tolerances were 0.4° for X-rotation, 0.17 ?? for Y-translation, and 0.03 ?? for Z-translation. This outcome confirmed that Z-translation is the most sensitive of the three.
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2017 Portfolio of CompositionsThe following collection represents the sum of works created by composer W. Aaron Rice during his Master's studies at The University of Arizona. This document provides programmatic introductions to each piece performed at the composer's Master's Recital, and the program from said recital is included at the end for archiving. The many separate pieces are introduced with details on compositional intent and brief analyses. In the pages following the introductions, full scores of each piece are included for detailed analysis.
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21st Century Change Agents? A Description of the Entrepreneurial Leadership Proclivities of Arizona Extension EducatorsThe current knowledge-based economy demands a workforce equipped with the skills to advance innovation through entrepreneurial strategies (Powell & Snellman, 2004). Currently, Extension educators contribute to social and economic development in the sectors of agriculture, natural resource, consumer education, and youth development. Extension educators provide community members with the knowledge and skills needed to obtain a higher quality of life. The strategies of entrepreneurial leadership are relevant to the contemporary work of Extension educators and would provide the opportunity to increase Cooperative Extension’s program planning and implementation success. For the purpose of this study entrepreneurial leadership proclivity is measured through two constructs, innovation and entrepreneurial strategy, in those identified as Cooperative Extension Educators throughout Arizona. The data collected in this study illustrated the lack of entrepreneurial leadership in Extension educators in Arizona, as well as recommends educational possibilities to increase the presence of entrepreneurial leadership.
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21st Century Workplace Competencies and the Connection between the University of Arizona College of Agriculture and Life Sciences and Undergraduate StudentsIn 2010, an Association of Public and Land Grant Universities (APLU) study (Crawford, 2010) found that the agricultural industry representatives, Land Grant University alumni, and government employees look for certain skillsets (e.g., communication, leadership) in prospective employees. With the U.S economy recovering from a major economic recession, a greater number of new UA graduates with undergraduate degrees from CALS have cause to be concerned about their overall workforce competitiveness. Crawford's 2010 study examined which soft skills students should possess in order to be deemed hirable by the agriculture industry. Building off of Crawford's research, the current study involves a needs assessment that examines how students perceive 21st century workplace competencies. Specifically, this study will explore and describe the level of perceived importance and ability of 2015 UA CALS students graduating with baccalaureate degrees specific to 21st century workplace soft skill sets. Such identification of needs gaps will lead to greater understanding of the connection between industry demands, higher education institutions, and undergraduate students. The current research required the generation of data capable of leading to insights into the current development needs of undergraduate students in the agriculture and life sciences disciplines specific to 21st century workplace competencies. Student perceptions of such competencies were measured first according to perceived importance, and then perceived ability (Borich, 1980). This descriptive research gathered information from participants with the goal of measuring, summarizing and generalizing among the study's target population (Ary et al., 2010). The results suggest which competencies UA CALS undergraduate students perceive to be important and how they perceive their own abilities within each competency. Descriptive statistics were used to describe the data relevant to each of the four research objectives framing this study. In particular, measures of central tendency and variability were used to assess the perceived levels of importance and ability subjects placed on individual competencies. To describe the professional development needs of CALS students in the seven constructs that together categorize 21st century workplace competencies as a whole (professionalism, team, leadership, decision making/ problem solving, experiences, communication, and self-management), mean weighted discrepancy scores (MWDS) were used to analyze the need for the competencies. Borich's needs assessment model was used to reveal the areas of highest training priority as determined by the MWDS.A web based questionnaire with multiple points of contact yielded 61 respondents with diverse backgrounds (e.g., transfer status, geographical background, major fields of study, co-/extra-curricular involvement) from across the college. Of the 52 competencies included within the seven competency categories, 16 had an MWDS that was prioritized as a tier I professional development need, which is of the highest priority. Of the remaining competencies, 20 of them had MWDS's that indicated tier II priority level set for professional development need. Lastly, there were 23 competencies that had MWDS's that indicated tier III priority level set for professional development need, which is the lowest priority level. Recommendations for curricular innovation to better foster student development in the context of the 21st century workplace are provided.
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A 3-dimensional structural analysis of diploid chromosomesIn this study, we are looking at the 3-dimensional chromosome structure of interphase diploid nuclei of Drosophila melanogaster. The goal is to determine the higher order structure of interphase chromosomes in these nuclei. Higher order structures include those structures larger than the 30nm fiber. Over the years, several general models for higher order chromosome structures have been presented. We look at three popular models for the organization of chromatin during embryogenesis, as each of these models make predictions that can be tested using high resolution in situ hybridization and image processing techniques. For this study we are using the Notch gene for in situ hybridization to embryos in cycles 10-14.Our preliminary results are inconsistent with the radial loop model. It appears that the chromatin might be arranged in folds of 30 and 10nm fibers. We also observe a difference in chromatin structure as the embryo gets older. As the Notch gene is being transcribed during cycle 14 we observe a puffing event. In this study we hope to expand on these observations and present further areas that need to be explored in order to conclusively distinguish these phenomena during early embryogenesis.
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340b Pharmacy Geographic Variation and Associated Socioeconomic Status340b Drug Discount program was originated in 1992 believing only 90 DSH hospitals who treat low income patients might qualify and with the simple mandate of ‘stretching scare federal resources.’ This research project evaluated the HRSA covered entity database testing hypotheses that the 340b program is growing disproportionately into higher SES neighborhoods over time. The data was categorized into three distinct time periods and each location entering the program was mapped over time from 1992 – Oct 2019. Using the most conservative and time relevant of three SES thresholds, SES variables were dichotomized into low and high SES. This research showed the 340b program, post ACA has grown in just 9 years from 6k entities to include over 64 k locations and is growing by an average of 850 new entities a month. Now over 4/5ths of all 340b entities are located in higher income areas. Ongoing rapid growth of 340b entities predominantly in High SES neighborhoods needs further discussion and research. (supplemental file: Tableau GIS map of 340b entities entering 340b program over time – 1992-Oct 2019)