Electronic Theses and Dissertations

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About: Electronic theses and dissertations (ETDs) are the graduate research outputs of Texas Tech University. They represent years of work from our Master's and Doctoral graduates. If you find the ThinkTech digital repository useful, please tell us! Share how open access to scholarship benefits you. Your story matters to us.

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    Post-fire herbicide application yields largest reductions of Macartney rose (Rosa bracteata) in Attwater’s prairie-chicken habitat
    (2023-05) Lechnar, Catherine V.
    Macartney rose (Rosa bracteata) and red imported fire ants (Solenopsis invicta, RIFA) have invaded the coastal prairie of Texas, a highly fragmented ecosystem. The Attwater’s prairie-chicken is endemic to the coastal prairie and is critically endangered due to habitat loss and a lack of resources. At Attwater Prairie Chicken National Wildlife Refuge, patch burn grazing as well as pesticides are used to manage invasive species and improve plant and arthropod diversity as a diet source for Attwater’s prairie-chickens. We implemented four herbicide treatments surrounding Winter 2021/2022 prescribed fires to better understand how herbicide (GrazonNext HL) alters Macartney rose cover and density, the plant and arthropod communities, and RIFA populations. Herbicide was applied either before fire, after fire, before and after fire, or not at all in plots throughout the refuge. We found plots that received herbicide before and after fire to be the only plots that had significant reductions in both cover and density while plots that did not receive herbicide or only received it after fire had reductions only in density and plots that only had herbicide before fire did not see any reduction in cover or density. Further, we found over all increases in plant community diversity throughout the study with a great increase following prescribed fire. Arthropod diversity was not influenced by treatments, plant diversity, or RIFA populations, and RIFA were not correlated with any independent variables. This study found the herbicide GrazonNext HL to be ineffective when used only before fire and most effective when used both before and after fire to best reduce cover and density of Macartney rose. We found land history to be the most significant factor when understanding Macartney rose management where areas with frequent treatments away from surrounding private lands has much lower cover and density. Spraying herbicide and implementing prescribed fire every 2-3 years in this region over time has limited Macartney rose expansion.
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    Investigating the influence of dietary fiber source and multicarbohydrase supplementation on digestibility, energy, systemic health, water balance, and gut motility in gestating sows
    (2023-05) Crome, Thomas A.
    Carbohydrases supplemented in grow-finish pig diets can improve energy and nutrient digestibility and gastrointestinal function of growing pigs. However, research on their effectiveness in gestation diets is limited. The experimental objective was to evaluate the efficacy and mechanisms associated with multicarbohydrases in gestating sows fed soluble and insoluble fiber diets typical to U.S. production. A total of 36 confirmed gestating sows (186 ± 4.6 kg BW) were blocked by parity randomly assigned to 1 of 4 diets (n=9) in a 2×2 factorial arrangement of treatments on d 28 of gestation. Factors included fiber type of insoluble (IF; 15.1 IDF%) or soluble fiber (SF; 4.6 SDF%) and with (+) or without (-) enzyme (0.05%, Rovabio Advance P10; Adisseo, Antony, France). Diets were fed from d 28 to 109 of gestation at a feeding level of 2.1 kg (SID-Lys 11 g/d and 4.5 NE-Mcal/d). Two separate 9-d metabolism periods were conducted on d 50 to 59 (mid) and 99 to 108 (late) of gestation where serum and plasma were collected via jugular venipuncture. During each period, d 1 to 3 served as an adaptation period, d 4 to 7 total urine and feces were collected (96-h) and followed by a 48-h lactulose-mannitol study. Data were analyzed as repeated records using a linear mixed model with block as a random effect, and fiber type, enzyme, and period and their interactions as fixed effects. Irrespective of collection period, enzyme supplementation increased GM-CSF in sows fed IF but reduced it in those fed SF (Fiber×Enzyme P=0.042). Sows fed SF+ had increased serum IL-1ra (Fiber×Enzyme P=0.035), and IL-2 (Fiber×Enzyme P=0.042). In the presence of IF, multicarbohydrases increased serum LBP, but not when supplemented with SF (Fiber×Enzyme P=0.028). Circulating IL-8 (0.24 vs. 0.10 ng/ml) and TNF-a (1.26 vs. 0.60 ng/ml) were decreased in sows fed multicarbohydrases (Enzyme P<0.05). Multicarbohydrase supplementation increased the apparent total tract digestibility (ATTD) of GE, DM, and NDF by 2.8%, 3.4%, and 8.3%, respectively (Enzyme P<0.05). Compared to IF-, the ATTD of hemicellulose was 5.3% greater in sows fed IF+ but did not differ from SF- and SF+ (Fiber×Enzyme P=0.037). Furthermore, in late gestation sows fed IF had 11% greater ATTD of hemicellulose (Period×Fiber P=0.035). Sows fed multicarbohydrases excreted less energy in their urine (519 vs. 469 GE kcal/d; Enzyme P=0.033) and in their feces (985 vs. 900 GE kcal/d; Enzyme P=0.003). This resulted in an improvement in both DE (3723 vs. 3856 kcal/kg; Enzyme P<0.01) and ME (3484 vs. 3583 kcal/kg; Enzyme P=0.041), irrespective of fiber type. Sows had a 3.5% greater ME in late gestation (3451 vs. 3572 kcal/kg; Period P<0.01). In conclusion, multicarbohydrase supplementation increased the energetic contribution of IF and SF in sow diets and may reduce systemic endotoxin and inflammatory pressures throughout gestation, but mechanisms are unique to dietary fiber type.
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    Do College Students’ Views of Psychedelics Depend on the Context for Psychedelic Use?
    (2023-05) Petrovitch, Dan
    There are three unique contexts for psychedelic use: clinical therapies, naturalistic use, and microdosing. Emerging clinical psychedelic therapies in particular present a promising opportunity to reduce more harmful forms of substance use (e.g., alcohol, tobacco). To inform future research investigating opportunities for treatment and harm reduction, this study examined psychedelic-naïve college students’ views of psilocybin and LSD. Specifically, it compared participants’ expectancies, perceptions of benefits, and perceptions of harms across each context and examined relations between these views and levels of non-psychedelic substance use. Method: Participants completed multiple item pools assessing views of psychedelics, which were adapted from several previous studies; questions from the AUDIT, CUDIT-R, and DUDIT were used as proxies for other substance consumption. Data were analyzed at the item level using non- parametric techniques that are appropriate for categorical data (i.e., Friedman, sign, Cochran’s Q, and McNemar tests; Goodman and Kruskal’s gamma). Corrections for multiple comparisons were made using the Benjamini-Hochberg procedure. Data: Participants were 317 undergraduate students enrolled at a large, Southwestern US university (74.76% female; 80.76% white; 74.13% non-Hispanic), with a mean age of approximately 19.78 (SD = 3.09). All reported being psychedelic-naïve (i.e., never having consumed a psychedelic substance in their lifetime). Results: 29 omnibus tests assessing participants’ views of psychedelic substances across contexts were statistically significant; descriptive statistics and follow-up tests indicated that, when participants’ views of psychedelics were context dependent, they generally had the most positive views of clinical contexts, then microdosing, and then naturalistic contexts. 89 associations between participants’ views of psychedelic substances and their levels of non-psychedelic substance use were significant; these relationships all involved levels of cannabis use (not alcohol or other drugs); and they were all directionally positive, such that more positive views of psychedelics were associated with higher levels of substance use. Conclusions: Taken as a whole, these data indicate that psychedelic-naïve undergraduates tend to view clinical contexts for psychedelic use as the most beneficial and least risky, followed by microdosing, and lastly naturalistic contexts. However, a) this pattern may depend on how such perceptions are operationalized and measured and b) effect sizes of significant distinctions between contexts tended to be small. They may also exhibit stronger relationships between views of psychedelics and levels of cannabis use than views of psychedelics and levels of alcohol or other drug use. Implications include the importance of sharply defining differences between contexts to assess context-related variables as separate constructs where necessary (e.g., clearly explaining microdosing when an item/scale refers to that).
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    Internalizing Symptomology and the Role of Perceived Partner Drinking
    (2023-05) Himes, Katie P.
    The current study examined relations between perceived partner drinking and symptoms of anxiety and depression, described components of different drinking partnerships, and tested how these partnerships relate to internalizing symptomology. Participants included a sample of 181 Texas Tech University undergraduate students in current romantic relationships who completed self-report questionnaires on measures evaluating internalizing symptomology, relationship satisfaction, as well as reported and perceived partner drinking behaviors. K-means and K-medoid cluster analysis was utilized to partition collected data into distinct clusters that varied on self-reported and perceived partner drinking as well as self-reported and perceived partner drinking problems. Hierarchical linear regression was used to examine how these dummy-coded clusters relate to reported anxiety, depression, and relationship satisfaction. Perceived partner drinking quantity and problems were significantly associated with symptoms of depression (r=.08-.16). Further, two drinking quantity (concordant light, concordant heavy) and three drinking problem partnerships (concordant light, discordant female high, discordant male high) were identified. Interaction terms between drinking partnership and sex explained significantly more variance in reported relationship satisfaction, depression, and anxiety than prior models accounting for the effects of sex, one’s reported drinking, and drinking partnership. Broadly, it was demonstrated that men’s anxiety and relationship satisfaction were significantly impacted by their drinking quantity and problem partnerships; this effect was not observed for women. Men’s depression was not significantly impacted by their drinking quantity and problem partnerships. The results of this study suggest that individual and relational outcomes are impacted by perceptions of their partner’s drinking, and have important treatment implications for clinical interventions with men, such as developing coping skills and monitoring alcohol-related distress.
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    Increasing Efficiency of Aeroponic Vegetable Production
    (2023-05) Newberry, Kamron L.
    The adoption of soilless culture in controlled environment agriculture (CEA) has gained popularity in recent years. Innovative technologies have aided in the advancement of CEA. Hydroponically grown produce is widespread in the industry today, but this method of growing uses large quantities of water in order to bring a production facility online. While this is often less than field production, other options can further increase water use efficiency in CEA. Aeroponic crop production could be the solution because it has shown promising results in increasing resource efficiency. However, there is no standard for designing, building, and best practices within aeroponic production systems today. Therefore, the objective of this study was to design and build an aeroponic system and track lettuce growth and development in deep water hydroponic and aeroponic systems. Then determine if by decreasing the spray durations within an aeroponic system, can we maintain lettuce yield while reducing the total water and nutrients used compared to a deep-water hydroponic unit. Plant physiological data on aerial and root tissues were collected throughout these experiments. Data showed that aeroponically produced lettuce had larger yields, increased root development, and higher CO2 assimilation. Furthermore, head weight was 60% greater in the aeroponic production systems during the first experiment. Roots were analyzed using WinRhizoPro, which showed that aeroponically produced plants had more roots in the fine and very fine classifications than hydroponically produced plants. To analyze optimal spray durations, we adjusted durations to 100% (30 sec on 5 minutes off), 75% (22.5 sec on 5 minutes off), and 50% (15 sec on 5 minutes off) for Trial 1 and 100% (15 sec on 5 minutes off), 75% (11.25 sec on 5 minutes off), and 50% (7.5 sec on 5 minutes off) for Trial 2 for the second experiment. This study found that a spray duration of 30 sec, 22.5 sec, and 15 sec produced plants with higher yields, longer roots, and increased Nutrient Uptake Efficiency (NUE) compared to the hydroponic system. A decrease in plant vigor was observed at a 7.5 sec spray duration, leading to smaller plants, lower NUE, and decreased chlorophyll concentrations. Therefore, we conclude that while all but the aeroponic 7.5 sec spray duration outperformed the hydroponic system, the spray durations within the aeroponics systems were similar in yield and resource use efficiencies.
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    Effect of a novel Alternate Day Intermittent Energy Restriction Intervention vs. Standard Reduced Calorie Diet on Body Weight, Body Composition, and Resting Metabolic Rate in College Students with Overweight / Obesity: A Pilot Study
    (2022-12) Basu, Tanisha
    Previous research has shown a high prevalence of overweight / obesity among the population of college students. Erratic schedules and feeding behaviors, disordered sleep and increased stress are also common within this population. Intermittent fasting / energy restriction regimes focus on alternating between periods of ad libitum feeding and energy restriction. These are similar to calorie restriction diets in yielding weight loss and adherence. Currently, there is a gap in research that examines the effect of specific dietary interventions targeting weight loss among undergraduate students. Therefore, we aimed to determine the effect of a novel, alternate day intermittent energy restriction intervention on body weight, fat mass and resting metabolic rate of college students with overweight/obesity as compared to a standard reduced calorie diet. To achieve this, we designed a 4-week randomized controlled trial (4-week) with an experimental group that received the novel alternate day intermittent energy restriction (AltER) diet and a control group that received a standard reduced calorie diet (RCD). 17 participants were enrolled, data was analyzed from the 10 who completed both visit 1 and 2 of the study. At the first visit, demographic/health and weight history information was obtained. At both visits, body composition and resting metabolic rate (RMR) were measured; and the following self-report questionnaires were obtained: Pittsburg Sleep Quality Index (PSQI), Perceived Stress Scale (PSS), and the International Physical Activity Questionnaire (IPAQ). Change scores were calculated to see pre- and post- differences. T-tests were done to compare the difference in mean change scores of body weight, body fat percentage and RMR between the two groups. There were no significant differences observed between the two groups with regard to the primary outcomes of interest. Sleep and stress were also not found to be significant predictors of the primary outcomes. Interestingly, it was noted that the dropout rate in the AltER group was much lower than the RCD group. This pilot study was a successful feasibility trial as both groups lost weight and there were some patterns noted that warrant further investigation. It is likely with longer duration, adequately powered studies we may see how the unique attributes of the AltER diet be beneficial to college students and other similar populations.
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    Design and Characterization of an Explosive Opening Switch for Flux Compression Generator Applications
    (2022-12) Harrison, Nicolas
    The study of an explosive opening switch (EOS), including the design and build of a test bed, is discussed in this thesis. An explosive opening switch (EOS) operates on the principle of a conductor’s mechanical destruction from the detonation of a high explosive (HE). Specifically, an explosive opening switch acting as a circuit disconnect capable of a 200 kA pulse just before opening and a voltage hold off of 50 kV for 100 us after opening is studied with application in a multipulse FCG. The EOS under discussion differs from the traditional use of EOSs, including but not limited to current pulse sharpening and power conditioning, with typical applications in MCGs and FCGs, or other explosive-type generators. This research considers two configurations of EOSs: a cylindrical EOS with detonating cord as the HE core and copper/aluminum tubing as the outer conductor and a flat configuration with copper/aluminum foil laying flat over detonating cord. Varying lengths and thicknesses of the conductors are studied. The switches’ effectiveness is studied using voltage and current measurements and high-speed imaging. This thesis discusses in detail a testbed comprised of a 36 uF capacitor, EOS housing structure, 50 kV pulse supply, high-speed cameras, and other equipment and tools for diagnostics and explosive detonation. This thesis contributes to the overall better understanding of explosive opening switches. Further, it reveals a sense of EOS parameters for applications where a circuit disconnect or circuit isolation is needed.
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    Movement Ecology of the Black Flying Fox (Pteropus alecto) in a Changing Landscape: Implications for Hendra Virus Spillover in Eastern Australia
    (2022-12) Dale, Adrienne
    Historically nomadic, black flying foxes (Pteropus alecto) traveled hundreds of kilometers across the landscape in search of seasonally ephemeral plant food resources. Land clearing has decreased native habitat of P. alecto in coastal eastern Australia and increased seasonal variability in native food sources, driving flying foxes into continuously-occupied roosts in and around urban areas. As a natural host for Hendra virus, understanding P. alecto movement is critical to understanding Hendra virus and its transmission and spillover dynamics. High densities of smaller roosts, along with consistent resources temporally, led us to hypothesize that bats in urban roosts would forage closer to the roost sites than previously recorded for bats at non-urban roosts. However, we expected that bats would exhibit seasonally variable movements, especially as native resources are increasingly unavailable in winter months. We investigated foraging distances, track tortuosity, and foraging ranges, by tracking 76 adult P. alecto from two continuously occupied roosts using GPS-GSM trackers. One roost is in a highly urbanized area, and the other is in a peri-urban area, adjacent to native habitat. We collected 883 bat-nights of tracking data (722 foraging nights and 161 roost-switching nights) throughout 2019–2021. Although we observed occasional extreme nightly movements (up to 218.27 km), most nightly foraging distances and maximum displacement calculations from the roost were comparatively short (mean 7.0 ± 5.0 km). Bats travelled longer distances when foraging from the peri-urban roost, with individual mean track lengths ranging from 8.7 – 51.6 km compared to 3.7 – 44.4 km at the urban roost. Bats from the urban roost predominantly foraged locally in developed areas, whereas bats from the peri-urban roost displayed a mixed foraging strategy, exploring developed, agricultural, and native landscapes. Understanding foraging movements of urban resident flying foxes can help prevent human-wildlife conflicts and promote coexistence in and around increasingly urban environments. Insight into how the movement ecology and foraging behaviors of P. alecto could affect Hendra virus spillover and dynamics in this system could also further help us understand other zoonotic diseases globally.
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    A first-principles study of transition metal surfaces
    (2022-12) Diaz, Leopoldo III
    The effect an adsorbate species on copper (Cu) and tungsten (W) is examined in two parts using first-principles density functional theory calculations; for both studies the (100), (110), and (111) surfaces were studied. An oxygen monolayer was adsorbed onto the surface of Cu and the electronic properties were examined. The existence of an oxygen monolayer on the surface of Cu was verified by calculating the adsorption energy. The total density of states revealed little changes upon adsorption of the oxygen monolayer. However, when an external electric field was applied to the clean and oxidized surfaces it was shown that the clean surface was greatly impacted while the O/Cu surface was not. The O/Cu surface was not effected because of the presence of strong directional bonding and the O-Cu bond being strong enough to overcome the effects of the electric field. A first-principle approach was used to study the effects of an alkali metal iodide \emph{X}I ($X=$ Li, Na, K, Rb, and Cs) on the work function of the (100), (110), and (111) surfaces of W. The adsorption of the alkali iodides revealed three distinct trends: (1) for all systems the most energetically (lowest formation energy) stable XI/W (111) surface had the smallest work function reduction while the least energetically stable (highest formation energy) XI/W (110) surface had the largest work function reduction. Using the total density of states (TDOS), it was determined that XI/W (111) surfaces had the strongest bonds resulting in the highest work functions. (2) For all surface orientations, from LiI/W to CsI/W, the formation energies are increasing while the work functions are decreasing, and (3) the calculated work function reduction was largest for the XI/W (110) surface despite having the largest clean surface work function (up a 3:51 eV reduction for CsI/W (110)). Additionally, it was previously suggested that the electrostatic energy is responsible for the dipole orientation and work function reduction. Contrary to the suggested model, the dipole orientation and work function reduction is dependent on the elastic strain (size-effects) caused by the alkali metals.
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    Preventing User Radicalization by Automatically Detecting Misinformation Videos
    (2022-12) Latif, Lawzeem
    Online misinformation has become a very large problem with the rise in information sharing capabilities of social media. The rise in such misinformation has in turn influenced and lead to many cases of radicalization which has resulted in many unfortunate situations. Detecting misinformation is computationally expensive and usually by the time it is found and removed, the content has spread to many places. Additionally, online echo-chambers often exacerbate the spread of misinformation and without any oversight can lead to users getting radicalized. In this thesis, I will look at leading research papers on how to detect misinformation using multiple methods and how to detect potential echo-chambers. Using that knowledge, I will propose a video ranking algorithm that will attempt to prevent user radicalization by automatically detecting potential misinformation content.
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    Co-overexpression of AVP1/PP2A-C5 in cotton to enhance cotton abiotic stress tolerance and fertilizer use efficiency
    (2022-12) Cai, Yifan
    Food security is currently threatened by more challenges such as the increasing world population, climate change, and toxic metal contaminated arable land. To meet the demand of feeding and clothing the increasing world population, it is necessary to enhance crop yield in the world. Cotton is a major fiber crop for Texas Southern High Plains, as well as for US, unfortunately cotton production is facing a severe challenge imposed by those threats. Overuse of fertilizer in agricultural production has caused salinization in soils worldwide, leading to unbalanced nutrients in soils that caused huge yield losses in many semiarid regions in the world. In addition, toxic metal is another important threat limiting agriculture production and it affects plant, animal, and human health. This research uses Agrobacterium-mediated plant transformation to co-overexpress PP2A-C5, and AVP1 in cotton and aims at generating a cotton variety with high fertilizer use efficiency that can also functions as a metal hyperaccumulator to clean toxic metal contaminated arable land. AVP1 is a vacuolar membrane-bound H+ pyrophosphatase, and overexpression of AVP1 in plants could increase tolerance of toxic metals and fertilizer use efficiency. The PP2A-C5 is the catalytic subunit 5 of the Arabidopsis protein phosphatase 2A. Overexpression of PP2AC5 in Arabidopsis could increase tolerance to NaCl, KCl, LiCl, and KNO3. In this study, we found that AVP1/PP2AC5 co-overexpressing cotton performed better under low fertilizer conditions than AVP1-overexpressing cotton and wild-type cotton. In addition, we found that AVP1/PP2AC5 co-overexpressing cotton performed better and accumulated more lithium under high lithium condition than wild-type cotton. Interestingly, AVP1/PP2AC5 co-overexpressing cotton exhibited higher N, P, K use efficiency under high lithium conditions as well in comparison with wild-type cotton plants. Those data prove that AVP1/PP2AC5 co-overexpressing cotton could serve as a hyperaccumulator plant for lithium, and it could be used to clean fertilizer overused soils.
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    Understanding piezoresistive soft composites as applied to multi-directional tactile sensing arrays
    (2022-12) Rogers, Jeremy
    An improvement in tactile force sensing has far reaching implications in many fields. To enable human robot interaction machines must be able to mimic human dexterity. Piezoresistive soft composite materials are one transduction mechanism of great interest to researchers for this purpose. Flexible piezoresistive films are often used as skin analogs and integrated into complex array sensors for tactile sensing. Each mechanism has distinct advantages and disadvantages, but the optical, thermal, and mechanical properties - combined with cheap fabrication cost - make these composite materials good candidates for force sensors. The main goal in this work is to characterize a soft piezoresistive layer in both tension and compression to enable a model system for a piezoresistive tactile force sensor and a characterization platform. In this paper a cantilevered beam is proposed as a base mounted force sensing mechanism. The uniformity of the sensor characteristics heavily depends on the homogeneity of the composite. However, the processes are complex and must be characterized before use. Tests carried out at multiple locations yielded consistent sensitivity values, making these types of composites suitable for array type force sensors. Therefore, the ability to locally characterize a film that will be integrated into a complex force sensor could be critical. Here, several methods to characterize the local sensitivity of flexible piezoresistive films is presented. Multi-walled carbon nanotubes and carbon black are mixed by weight with soft polyurethanes in 13% to 18% concentrations. Numerical calculations are used to simulate several aspects of the materials and the sensors. These simulations are then compared to the experimental tests. Results show that lower weight percentage composites exhibit a higher rate of change of resistivity and gauge factor than films of the same thickness with higher percentages. On the other hand, thicker films exhibit higher gauge factors for the two tested carbon black contents. A linear fit is applied to the ∆ R⁄R vs strain graphs to calculate the gauge factors. ∆ R⁄R vs strain graphs for tension and compression show gauge factors between -8 and 10.3 with the range decreasing with increasing MWCNT percentage.
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    The Men of Echelon One: Comparative Analysis of Company Aid-Men in Pacific and European Theaters of World War II
    (2022-12) Yates, Trevor C.
    The United States’ aid man or medical corpsman’s World War II experience was largely unprecedented in U.S. military history. There are several reasons why World War II served as watershed moment in the duties of the aid man. First, the mobility of the front lines increasingly removed the aid man from the established aid stations, where his performance of treating combatants and civilians was conspicuous to those who might call on him, like front-line infantry, airborne troops, and mechanized forces. The philosophy of treating battlefield wounded has been present in “Western” militaries since the days of Alexander. The primary effort for removing wounded from the field was not always based on a humanitarian effort, but more one of physically and psychologically maintaining a fighting force. This persists until the advent of first aid and the acceptance of the principles of the International Red Cross. Borrowing from European experience in battlefield care, the United States aid man was borne of two philosophies, a logistical aspect of battlefield care and a spiritual one. Second, while disease was the predominant casualty producer in previous American conflicts, 1944 was the year battlefield casualties exceeded disease related, non-combat casualties. This was not apparent to the aid men at the time, as they served in a multitude of functions near the front, including, litter-bearers, aid station attendants, drivers and sometimes, triage agents in identifying the onset of psychoneuroses in the front-line troops. Unlike previous wars, the United States fought on an unprecedented scale, on two fronts. The unique circumstances that each major theater encumbered upon the aid men are compared to explore the similarities and differences of their experiences, mostly through the perspective of the aid men who were there, and the people who witnessed their acts. Although the aid man role had been in practice since 1887 and had been deployed in two previous wars, it is the experiences of the aid men on two fronts that give rise to a collective respect of this healer, culminating in the creation and awarding of the Combat Medic’s Badge, and eventually a” combat pay.” The general perseverance of the aid man was noted not only by the troops, who increasingly referred to him “doc” but also the writings of Ernie Pyle, the U.S. Army’s campaign to highlight infantry, the drawing of Bill Mauldin, and the accounts of physicians he worked for and most of all the men he treated.
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    “No somos gitanos”: Cracking the Code of the Kale Blacksmiths of Early Modern Triana
    (2022-12) Williams, Gretchen
    This ethnographically informed micro-history focuses on the Romani (Kale) blacksmiths of the Triana neighborhood in Seville in the long sixteen century, emphasizing the importance of place for this community. So often the Romani are generally assumed to have little connection to a singular location because they are “inherently nomadic wanderers.” They are portrayed in paintings, plays, poems, and laws as drifters who seek the freedom of the road to the detriment of society. This dissertation presents a starkly different reality of these blacksmithing families from Triana, focusing on this neighborhood as it was home to a notable Kale population since their arrival into the Iberian Peninsula in the fifteenth century. By focusing at the community level we now see specific ways in which this group, often assumed to exist at the margins, in fact played a central role in a centrally important trade for the ever-expanding Spanish Empire. These families, living on Castilla Street for approximately 150 years were experts in producing screws and other small iron works known as chapurrería. It appears that the Kale blacksmiths of Triana were the primary producers of small iron works in the city of Seville for centuries, and specifically for various types of ships constructed and repaired in Seville’s bustling ship building industry. The research for this dissertation is archivally based but also draws from evidence of material culture to connect Kalo individuals who would have otherwise remained historically invisible. This dissertation will also explore the process of ethnic reclassification which has contributed to the archival invisibility of the Kale, touching on the concept of race in early modern Spain. This work brings to light the story of a community who has remained largely invisible, but who played an important role in the Spanish economy both in Spain and the Americas.
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    Introduction and Application to “High School of Cello Playing” 40 Etudes Op.73
    (2022-12) Xie, Yali
    The “High School of Cello Playing” 40 Etudes, Op.73 was composed in the romantic period by Czech cellist and educator, David Popper. It is not only a significant teaching and practicing aid for cellists, but indispensable for the cultivation of a well-developed ear. This paper will introduce the etudes, composer and other relevant works. Then analyze and summarize the etudes by performing technique and difficulty to help teach or practice in a specific, targeted manner.
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    Advances in Modeling Adsorption and Adsorption Processes
    (2022-12) Sees, Michael D.
    Incremental improvements in computing power and process simulation software, as well as concerns over sustainability and cost of chemical processes, has brought adsorption technology back to the forefront of research in the last several decades. Academics and industrial practitioners alike need guidance on methods for modeling these processes, particularly for historically difficult processes like pressure swing adsorption. This dissertation seeks to help fill this role by discussing advances in modeling adsorption processes in steady-state simulators from thermodynamics to process systems engineering. A tiered modeling methodology for PSA is recommended to make modeling more accessible for engineers. A shortcut model for simulation of PSA processes is proposed, based solely on mass and energy balances, which uses the concept of “adsorption efficiency” to account for non-ideal behavior which occurs during operation. The model is then used in a simulation task to demonstrate its potential, and transient simulations are used to investigate the behavior of the model’s parameters. An additional model based on equilibrium countercurrent stages is prepared to model a related gas separation process, and the applicability of efficiency concepts is investigated. Lastly recommendations for models for heterogeneous adsorbents were made based on their theoretical and practical merits.
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    An Optimized Noncontact Vital Signs (NCVS) System for Potential Patient Monitoring Enabled by Robust Software Defined Radio (SDR)
    (2022-12) Liu, Yang
    Monkeypox is starting to spread while COVID_19 is still around, and the seasonal flu also breaks out yearly. As many of these diseases affect the vital signs of the patients such as blood pressure, temperature, respiration rate (RR), and heart rate (HR), these vital signs data will greatly help the medical workers to do the early diagnosis. This paper describes an optimized Software Defined Radio (SRD)-Enable Noncontact Vital Sign (NCVS) system which has the potential to monitor patients heart rate and (HR) respiration rate (RR) remotely with very high accuracy. Dr. Lie’s lab has been on working on this project for several years, and a prototype system was delivered in 2019. The paper begins with the motivation that inspired the project. Next the fundamental principle of the system is described. An illustration about the hardware devices, their setup and software programing is given. The optimization process with experiment results obtained at lab and clinical trial data will be further discussed. Next, a conclusion and the prospect of the system are presented. Finally, test data verifying the integrity of the system is presented along with its use in additional applications.
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    The Influence of Selenium on: Selenium Uptake, Salt Stress, and Fluoxetine Uptake in Hydroponically Produced Indian Mustard (Brassica juncea cv. Red Giant)
    (2022-12) Cognasi-York, Savannah
    Selenium (Se) is an essential nutrient in the human diet and helps build selenoproteins involved in DNA construction, thyroid hormone production, and reproductive success. Plants are the primary source of Se in the human diet; therefore, humans can be deficient in Se if a balanced diet is not achieved. However, Se toxicity can also harm humans, animals, and plants if present in excessive amounts. Se occurs naturally in the environment and can be deficient or excessive in different regions. Therefore, previous studies have endeavored to biofortify or remediate Se to produce Se-enriched produce or remove excess Se in the environment to protect surrounding ecosystems. Incorporating Se into production methods to improve Se content in plants has shown many promising results, but these vary by crop, Se dose, and Se species. Though not essential for plant growth and development, Se can be beneficial at specific concentrations. Se can behave as an antioxidant at low concentrations, improve resistance to pests, and mitigate abiotic stress influences; however, high concentrations can act as a pro-oxidant and induce oxidative stress. The delicate balance between beneficial and toxic concentrations is species-specific and depends on environmental conditions and production methodology. Therefore, our experiment was designed to determine the beneficial threshold for Indian mustard biofortification in a hydroponic system. Through this experiment, we determined a 10 µM Se dose, applied as sodium selenate (Na2SeO4), was least detrimental to Indian mustard height, fresh and dry biomass, and nutrient content compared to a 20 µM Se dose. More Se was also recovered from plant tissues and water systems in the 10 µM Se dose compared to the 20 µM Se dose. Alternative water sources such as greywater and wastewater have proven beneficial in safeguarding potable water, providing year-round reliability, reducing the cost associated with water use, and providing essential plant nutrients. However, these secondary water sources contain 1.5-2 times higher salinity levels than freshwater sources, which can be detrimental to agricultural production systems subject to this irrigation. Salinization is a global issue that costs the agricultural sector approximately $12 billion annually, and persistent irrigation with poor-quality water will only intensify salinity issues and negative environmental impacts. Se is a beneficial element to plant growth and development with antioxidative properties that can help plants mitigate some stress responses. Current research demonstrates the benefit of Se supplementation in systems irrigated with saline water, but results vary by crop, production method, salinity concentration, and Se concentration. Therefore, to study the impacts of Se on salt stress in a hydroponics system, we conducted a replicated experiment with Indian mustard and evaluated plant growth and physiology. The primary objective of this experiment was to demonstrate the tolerance of Indian mustard to different salt concentrations when treated with 10 µM Se. Salinity treatments 2.5 and 5.0 dS/m spiked with 10 µM Se were compared to a control treatment containing no Se and no NaCl to compare the physiological differences between an optimal growth system with pure water and a growth system mimicking poor-quality water sources. Results from these experiments conclude that there is no significant difference between the control and 2.5 dS/m salinity treatment in height, fresh and dry root weight, and micronutrient composition in shoot and root tissues upon Se supplementation. The 5.0 dS/m treatment, however, was significantly lower in height, biomass, and nutrient composition compared to the control and 2.5 dS/m NaCl treatment. Proline concentrations were also elevated with increasing salt application and demonstrated increasing salinity stress at a physiological level, even at the lower salinity treatment. These findings show that while Se can mitigate some of the negative impacts of salt stress, physiological stress responses can still occur. Fluoxetine (FLU) is a frequently prescribed selective serotonin reuptake inhibitor (SSRI) used for the treatment of clinical depression, obsessive-compulsive disorder (OCD), and bulimia. This medication is non-bioaccumulative by design, resistant to degradation and is therefore often found in different water systems following water treatment procedures. FLU disrupts multiple biologically essential functions in non-target organisms, consequently affecting their stress responses, reproductive success, and feeding patterns. Multiple research disciplines have investigated different remediation techniques for FLU; phytoremediation is an agricultural remediation technique for a variety of contaminants, yet few studies have investigated the removal of FLU from different water effluents by phytoremediation. Therefore, this study was designed to determine the uptake and partitioning of FLU into different Indian mustard tissues. Results from this experiment show that a 9.0 µg/L FLU treatment negatively impacted harvest height, fresh shoot biomass, and dry shoot and root biomass, compared to a control and 18.0 µg/L FLU treatment. It was also determined that FLU concentrations were significantly greater in shoot tissues compared to root tissues, which is likely due to the molecular weight (MW) of FLU. Overall, FLU was recovered from water and plants in lower amounts than expected, ranging from 30-40% depending on FLU dose applications. This suggests that degradation of FLU occurred, yet no metabolites of FLU were analyzed in this study.
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    Genomic and Economic Study for Improvement of Peanut Water Deficit Stress Tolerance
    (2022-12) Sung, Cheng-Jung
    The Ogallala Aquifer has been depleting rapidly, and this poses a significant long-range challenge to agriculture in the Southern High Plains area of Texas. Peanut is one of the most important crops in this region but requires more water relative to some crops. Therefore, it is important to develop peanut varieties that are tolerant to water deficit for reducing the use of irrigation water. One of the research projects estimated yield, grade, hundred-seed weight, revenue, and gross margin for evaluation of genotypes performed well under water deficit. Some breeding lines and mini core accessions showed overall better performance among all genotypes including some current varieties when under water deficit stress. These genotypes have potential to be released or used as breeding material for developing drought tolerant peanut varieties. To assist with breeding programs, the identification of useful molecular markers could help for selection toward desired traits related to water deficit stress tolerance. Marker identification in this research was done by using two approaches, SNP chip and RAD-Seq. Both approaches were performed using the U.S. peanut mini core collections in different locations and different years. GWAS analyses were performed, and around 300 significant SNPs were identified to be associated with yield, hundred-seed weight, NDVI, flower counts, SPAD, plant width, plant height, leaf closure, leaf wilting, seed grade, and CTD. To make useful markers become a routine tool for breeding programs, developing a suitable and reduced-cost genotyping system was important. In this research, 2,770 SNP targets were selected and designed into custom probes using the Tecan Allegro Targeted Resequencing V2 system, and 48 peanut samples that included some closely related genotypes such as sister lines were used as a trial experiment. Sequencing data from MiSeq were analyzed for identifying SNPs, and the results showed that this genotyping by targeted resequencing approach reduced the cost to around $18.88 per plant sample, with providing several polymorphic markers with accurate SNP calls.
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    Effect of Soot and Coal Fly Ash Particles on Human Lung Cells
    (2022-12) Dhaliwal, Hassanpreet K.
    Soot and coal fly-ash (CFA) are common anthropogenic aerosol particles emitted into the atmosphere. Their sources include vehicular/aircraft engines and industrial emissions. Millions of people are exposed directly or indirectly to these particles, as they work or live nearby coal power plants and airports. Both airborne CFA and soot are classified under carbon based PM2.5. These particles are small in size and can penetrate deeply into human lungs causing deleterious health outcomes, such as cardiovascular problems, lung cancer, adverse birth outcomes, and damage to the central nervous system, some of which may be fatal. The coal fly ash particles are a complex amalgam of different elements and minerals. Even though CFA is a major pollutant worldwide, there are very few studies which coherently characterize its toxicity based on its constituents. The pure toxicity of isolated soot particles is also not clearly understood. Its impact is predominantly known in the context of diesel engine exhaust due to the carcinogenic nature of vehicular emissions. Most of the in-vitro studies on the health impact of soot are done with ambient particulate matter and represent toxicity due to secondary pollutants like poly-aromatic hydrocarbons and heavy metals. There is very limited data on the toxic effects of isolated soot particles. This project investigated the impact of CFA and soot particles on human lung epithelial cells (A549). The CFA samples were obtained from three coal power plants in the United States while the soot samples were prepared in the laboratory. The cells were exposed to six different concentrations (0, 150, 200, 600, 900, and 1200 μg ml-1) for 24 hours and changes in cell viability for each concentration was assessed via cell population assay. The primary aims were to understand the impact of these particles on cell death, examine their dose dependent effects on cell viability, analyze the difference between their toxicities, as well as identify the constituents and physicochemical characteristics of an anthropogenic particle that make it toxic. The results showed significant (P < 0.05) toxicity for both the CFA and soot particles at all exposure concentrations compared to the control (no exposure). Further, a dosage-dependent trend in toxicity was observed. The CFA particles were sourced from the ambient environment and their particle toxicity was predominantly related to their constituent metal content and particle sizes. A higher cell death was found with increase in concentration of smaller particles (< 1 μm) and higher proportion of constituent metals such as calcium, selenium, and mercury in the CFA matrix. The soot particles were prepared in the laboratory from a propane flame and were relatively free from secondary pollutants. The relatively more hydrophilic black soot particles showed higher cell death at all concentrations in comparison to the more hydrophobic brown soot particles. The soot particles were significantly less toxic in comparison to CFA particles, mainly at higher concentrations. The cell death at highest concentration in the most toxic CFA (Missouri) sample was six times higher than that in brown soot. Thus, smaller size particles with higher amounts of constituent metals were responsible for higher toxicity of all carbon-based anthropogenic particles yet for pure, synthesized soot particles the physical properties such as solubility were a primary determinant of cell viability.