K-State Electronic Theses, Dissertations, and Reports: 2004 -
Permanent URI for this collectionhttps://hdl.handle.net/2097/4
This is the collection for doctoral dissertations and masters theses and reports submitted electronically by K-State students. Electronic submission of doctoral dissertations was required beginning Fall semester 2006. Electronic submission for masters theses and reports was required beginning Fall 2007. The collection also contains some dissertations, theses, and reports from the years 2004 and 2005 that were submitted during a pilot test project. Some items before 2004 have been digitized and are available in K-State Electronic Theses, Dissertations, and Reports: pre-2004. Check the Library catalog for dissertations, theses, and reports not found in these collections.
All items included in this collection have been approved by the K-State Graduate School. More information can be found on the ETDR Information Page. Items within this collection are protected by U.S. Copyright. Copyright on each item is held by the individual author.
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Item Open Access Laboratory learning’s role on chemistry self-concept: A mixed methods approach(2024) Base, DerekThis study examines the impact of hands-on chemistry laboratories in shaping secondary students’ chemistry self-concepts. Utilizing a mixed methods approach, the research sought to address how students’ chemistry self-concept varied during the first semester of an introductory chemistry course and give voice to students’ understanding of the role that laboratories play in their chemistry self-concept development. Data collection involved qualitative and quantitative methods, including surveys, open-ended responses, and semi-structured student interviews. Findings revealed that students formed a stable chemistry self-concept quickly during their introductory course, with some groups experiencing no variation during the first semester. Additionally, the findings highlight that students enrolled in a laboratory-intensive chemistry course highly valued the influence of hands-on laboratory experiments in shaping their chemistry self-concept, particularly those with lower chemistry self-concepts. Conclusions underscore the importance for educators and curriculum developers to recognize the role of chemical experiments in shaping students’ chemistry self-concept development. Recommendations for future research encourage the investigation of teachers' understanding of students’ development of their chemistry self-concept, a call to investigate students outside of honors chemistry, and further investigation into students' perception of inquiry and non-inquiry laboratories.Item Open Access Illuminating black student experiences in higher education: a critical narrative inquiry(2024) Harrison, ShukeylaWhite fragility has created a number of problems and challenges for Black students regarding authenticity and equality in the classroom. Racial discrimination in education and its disparities have come full circle mirroring history with the continued fight for an equitable education as a Black student. Black students continue to be mistreated and experience racial discrimination in the classroom (Witteveen &Attewell, 2022). For Black students, the effects of white fragility has had a detrimental impact on their academic success, especially on college campuses that are predominately white. Additionally, white fragility has led to disproportionate opportunities for Black students’ post-graduation (Witteveen &Attewell, 2022). Black women and men seeking employment post-graduation have a much more difficult time obtaining and retaining work because of white fragility (Witteveen & Attewell, 2022). Research literature surrounding authentic leadership theory (ALT) analyzes the “individual’s” authentic behaviors found between the subordinate and the supervisor in a work environment. My research talks about the gap in ATL that disregards authenticity in an academic environment specifically looking at the relationship between Black students and white faculty at predominately white universities. Therefore, the purpose of this study is to understand how white fragility impacts Black students and their self- authenticity in college and post-graduation. Findings from my research will provide data detailing how Black students struggle with white fragility in the classroom and that white faculty and staff are unaware of this. Findings also provide reasonable solutions for white faculty and staff to help improve and build healthy relationships with Black students in their classrooms.Item Open Access Optimization and design of isolated microgrid systems with the daily energy balance method(2024) Plett, EduardA state-of-the art alternative or supplement to the legacy electric power delivery system – the electric power grid – is the microgrid, a decentralized, local group of interconnected loads and distributed power sources that can operate in conjunction with or independently of the main grid, in a cooperative group or as stand-alone entities. The focus of this dissertation is the optimization and design of stand-alone, also called islanded or isolated, microgrids. Microgrids typically include various power sources such as engine generators, solar panels, wind turbines, fuel cells, and energy storage devices such as batteries. Given the high variability of power demand of loads, and the high variability of generated power by different types of energy sources; considering the completely different cost structures for different microgrid components, a major technical challenge is designing an optimal microgrid system, that is, determining the optimal combination of components for a reliable, stable, cost-effective and environmentally friendly microgrid system. Virtually all currently existing optimization approaches use extensive simulations to attempt to select configurations that match the generated and consumed power for each hour over the course of the project lifetime. This approach requires detailed system data, is computationally inefficient and slow; is not easily adaptable to different systems, different consumer profiles and different locations; requires expensive and complex software to operate; and in general is not very suitable for making practical engineering decisions. The novel method presented in this dissertation is uniquely different from all existing approaches in that it does not attempt to match power quantities. Instead, this method aims to achieve a balance between generated and consumed energy over the course of a day. To determine the amount of energy that can be generated by different sources, new and revised equations were developed that calculate the expected amount of energy generated by solar and wind power systems. In addition, new equations were developed to calculate the expected amount of energy that needs to be stored in batteries for reliable operation. A Generalized Reduced Gradient (GRG) and a genetic algorithm (GA) were then used to determine the optimum combination of components that minimize cost and maximize reliability. Unlike some other approaches, this method allows a high degree of customization. Various power profiles and various components can be selected, and multi-objective optimization operators produce optimization results according to the preferences of the user. The equations and results are easily verifiable and provide a high degree of confidence in the obtained solutions. This method is much more computationally efficient than other methods, and can be implemented on widely available computation platforms such as MS Excel. In short, this method is much more engineer friendly compared to all other approaches. To verify the validity of this method, the developed models and equations were tested with real-life production data of operational generator, wind, and solar power systems. The optimization algorithms were then run with power demand data of real-life small, medium, and large individual users, as well as with demand data for a community of multiple users. For all systems, the resulting configurations were then bench-marked to configurations determined by a specialty software tool called HOMER. In all cases the obtained solutions by the new method were superior in terms of reliability and economic as well as environmental costs, hereby confirming the validity of this method as well as its superiority to competing approaches.Item Open Access Genetic parameter estimation for beef bull fertility: A review(2024) Semler, MichaelReproductive efficiency is the major driver of profitability and genetic performance among all livestock species; advancements in husbandry practices and genetic selection tools to increase reproductive output have been well documented for cow fertility, but largely ignored for beef bull fertility in research and published literature. Estimation of beef sire fertility is economically relevant to not only the U.S. beef herd, but to the world, as the economic losses from sub fertile bulls and late pregnancies can have major implications on profitability while slowing genetic progress. Published studies that have assessed the genetic parameters of beef bull fertility traits are sparse in number, but indicate low to moderate heritability estimates for semen quality traits. Correlations amongst semen quality traits are also low to moderate, but favorable, indicating that indirect selection could provide opportunity for genetic advancement of particular traits. Genomic selection continues to make strides forward within the beef industry among other performance traits but has been underdeveloped in terms of fertility selection. Quantitative trait loci (QTL) for bull fertility discovered in dairy cattle have provided a basis for further research and examples of sire selection methods, however separations in management practices and slower adoption of AI forces the beef industry to look for other opportunities for data collection of phenotypic fertility traits. Ultimately, improvements in beef bull fertility have the potential to significantly impact the profitability of the global beef system by reducing cost, increasing selection intensity, and rapidly increasing genetic gain. Research regarding estimation of the genetic parameters of beef bull semen quality traits, development of genomic selection tools for fertility, and utilization of breeding soundness examination (BSE) records to provide valuable fertility phenotypes is gravely needed to make advancements in bull fertility a reality. The objective of this report is to discuss the various literature surrounding male fertility genetic parameters within both the beef and dairy industries.Item Embargo Influence of genetics on fertility traits in Angus bulls(2025) Stock, DanielleWhether a bull is used for natural mating or artificial insemination (AI), a single bull with suboptimal fertility can have a greater impact on herd productivity compared to a single female with reduced fertility. Despite this, extensive research on advanced reproductive technologies and genetic evaluations has focused primarily on female fertility, leaving a gap in the understanding of factors influencing male fertility. Therefore, the objectives of this study were to estimate the genetic parameters for scrotal circumference, sperm motility, and sperm morphology traits, evaluate the utility of combining breeding soundness examination (BSE) and AI bull stud collection data, and perform a genome-wide association study. Breeding soundness examination data were obtained from 4,996 Angus bulls, and stud collection data were obtained from 1,862 Angus stud bulls. The data were analyzed as a BSE dataset, a stud dataset, and a combined dataset with both BSE and stud records. Each of the three datasets were evaluated individually for genetic parameters. A single-step genomic best linear unbiased prediction (ssGBLUP) was used to estimate variance components and heritabilities of bull reproductive traits with the BLUPF90+ suite of programs (Misztal et al., 2014). The heritabilities estimated for scrotal circumference ranged from 0.36 to 0.55, while semen motility and morphology traits had lower heritability estimates of 0.04 to 0.12. Phenotypic and genetic correlations across traits in a single dataset ranged from low to high. Additionally, genetic correlations were estimated within traits to assess the relationship between a measurement taken during a BSE and at a bull stud, which resulted in low to moderate correlations. The significant quantitative trait loci (QTL) regions in the genome were identified at a significance threshold of -log10 P-value greater than 4.0 for scrotal circumference (SC), percentage of progressive motility (%MOT), motility score (MOTSC), percentage of secondary abnormalities (%SEC), and percentage of normal spermatozoa (%NORM). Previously reported QTL and candidate genes associated with fertility traits were identified. Results indicate that bull fertility is influenced by genetics, and selecting bulls with enhanced fertility could improve reproductive efficiency and herd productivity.Item Open Access Advising and belonging among undergraduate women in engineering: A narrative approach(2024) Adams-Wright, GaylaHigher education has long recognized women’s numerous challenges in undergraduate engineering programs. Several factors contribute to this lack of belonging, including a lack of diversity among student populations, microaggressions, prejudices, and traditions still rooted in male customs. An overlooked factor that may help foster a sense of belonging is undergraduate women’s conversations with academic advisors. Other studies have demonstrated that these conversations can contribute to a sense of belonging for underrepresented student groups. Faculty academic advisors, primary role advisors, and peer advisors are crucial in helping students connect with their educational, career, and life goals. This qualitative study focused on the following research question: To what extent do conversations with academic advisors contribute to a sense of belonging among undergraduate women in engineering? Using narrative inquiry to examine the stories women shared about their academic advising experiences, three themes emerged from the findings and underscore how these conversations contributed to feelings of belonging among undergraduate women in engineering. The first theme involves conversations with academic advisors who provide personalized support and guidance. The second theme revolves around conversations with academic advisors who offer encouragement during challenging experiences. The third and final theme concerns participation and engagement in conversations with peer advisors. This study highlights the positive impact that academic advising can have in fostering a sense of belonging among this population.Item Open Access Development of lipid-based nanoparticles for combination treatment of pancreatic cancer with hyperthermia(2024) Aparicio-Lopez, CesarPancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy, often asymptomatic and typically diagnosed at advanced stages. At the same time, treatment options include surgery, radiotherapy, and chemotherapy, only 20% of patients present with surgically resectable tumors. For most patients, chemotherapy remains the primary therapeutic approach, with gemcitabine, a nucleoside analog, serving as the standard of care. However, the dense fibrotic stroma, irregular blood supply, and heterogeneous tumor cell populations present significant biological and physical barriers, reducing gemcitabine’s efficacy and contributing to drug resistance. Drug delivery systems have been developed to address these obstacles by enhancing gemcitabine accumulation at the tumor site, primarily through encapsulation in long-circulating nanoparticles that exploit the enhanced permeation and retention (EPR) effect. Nevertheless, the unique architecture of PDAC tumors often limits the success of this strategy, with poor penetration and low bioactivity of gemcitabine at the tumor site remaining significant challenges. Additionally, gemcitabine’s physicochemical properties hinder effective nanoparticle loading, complicating therapeutic outcomes further. The primary objective of this dissertation is to address two major challenges in drug delivery for PDAC. First, it aims to develop gemcitabine-loaded nanoparticles that prevent drug degradation and enhance stability. Second, it aims to design these nanoparticles to be heat-sensitive, enabling controlled drug release through heat triggering mechanisms. We first designed and manufactured thermosensitive liposomes using varying ratios of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC), optimizing them for minimal drug release at physiological temperature (37°C). A two-stage hot water bath setup was employed to simulate temperature-induced drug release. In the first stage, the temperature was rapidly increased, followed by a holding stage at hyperthermic levels (42°C). This setup demonstrated that the liposomes exhibited fast drug release at hyperthermia temperatures. Despite successful thermosensitive performance, the liposomes displayed low encapsulation efficiency, which is consistent with existing literature but raises concerns about cost-effectiveness. To address the limitations of nonspecific hyperthermia, we developed a novel microwave-sensitive microemulsion. Multiple ionic liquids and surfactants were screened to formulate this system. To improve biocompatibility, DPPC, DSPC, 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N- [amino (polyethylene glycol)-2000] (PEG), and 1-palmitoyl-2-hydroxy-sn-glycero-3-phosphocholine (Lyso-PC) were incorporated. The final formulation included 1-butyl-3-methyl imidazolium bromide ionic liquid as the primary component, Tween 80/20 as surfactants, and ethanol-isopropyl myristate with lipids as co-surfactants. Dielectric measurements confirmed the microemulsion’s microwave sensitivity and further hyperthermia treatment demonstrated temperature-dependent cytotoxic effects in vitro. The drug delivery systems developed in this study exhibited negligible drug release at room temperature and physiological conditions (37°C) while showing effective cytotoxicity upon heat stimulation. Incorporating lipids and PEG ensured biocompatibility and stability in suspension, enhancing the potential for clinical application. This proof of concept marks a significant advancement in targeted drug delivery systems. Future improvements in gemcitabine-loaded vehicles, particularly those responsive to hyperthermia, could lead to critical clinical developments in drug delivery and hyperthermia-based treatments for PDAC.Item Open Access Real-time detection and recognition of license plate using YOLO11 object detection model(2024) Vempati, Ravi TejaThis research explores the need for accurate and efficient license plate detection and recognition using advanced computer vision and deep learning techniques. Traditional approaches to license plate identification are often manual, time-consuming, and prone to error, driving the need for automated solutions. This study aims to develop a real-time system for license plate detection and recognition by utilizing the You Only Look Once (YOLO) 11 object detection model in combination with Google Cloud Vision. The project involves gathering a dataset of high-resolution license plate images, annotating these images with bounding boxes, and performing data augmentation to enhance variability and standardize the data. The dataset is divided into training, validation, and testing sets to optimize model performance. The YOLO11 model is trained on this annotated dataset, followed by a detailed performance evaluation. The research also includes a review of existing methods in license plate detection and character recognition, highlighting the role of deep learning techniques in intelligent traffic solutions. Experimental results indicate that the YOLO11 model achieves impressive precision and recall rates, validating its effectiveness for this task. The final model is deployed on a real-time platform, integrating YOLO11 for detecting license plates and Google Cloud Vision for character recognition, thereby demonstrating its practical utility in traffic monitoring systems. This study provides a scalable and efficient framework for license plate recognition, contributing to the development of smart transportation solutions that enhance vehicle tracking and traffic management.Item Open Access Midwest by southeast: Aircraft manufacturing and the journey to Lao community building in Wichita, Kansas, 1975—1995(2024) Hill, HollyIn May of 1975, a refugee crisis began as the wars in Southeast Asia came to a close. When the communist Pathet Lao overthrew the Laotian monarchy and established a new country, hundreds of thousands of Laotians were made into refugees and fled their country. The ethnic Lao, separate from the northern Hmong tribespeople, were among the 1.1 million Southeast Asians resettled in the United States beginning in 1975. Though they share similarities with fellow Vietnamese, Cambodian, and Hmong refugees, the ethnic Lao have often had their histories overlooked, which this thesis seeks to rectify. It discusses the long journey of ethnic Lao refugees from their homeland to Wichita, Kansas, showing them as actors in their stories rather than victims acted upon. It begins with the role the United States had in turning refugees into refugees, their experiences in refugee camps, and the legislation which allowed them entry into the country. Once here, they struggled to adapt while finding jobs and building their lives amidst the country’s devastating economic recession. This thesis asserts that coveted aircraft jobs in Wichita, “the Air Capital of the World,” provided security to ethnic Lao refugees and helped them to build a distinctly Lao American community in the American heartland.Item Embargo Seed yield and quality of soybeans across the US: an overview of management and environmental characterization(2024) Pereyra Picabea, Maria ValentinaSoybean (Glycine max L.) is the main oilseed worldwide with the United States (US) producing 29 % of the global production (125 million Tn). The main targets of crop production in soybeans are yield (farmer profit), and seed quality in terms of protein (soybean meal for animal feed), and oil (for human consumption and biofuels). Seed yields are relatively stable due to the capacity of branches and nodes to adapt and maintain yield per area in diverse environmental conditions. However, soybean quality exhibits significant variation both within and between regions due to environmental, genetic, and management factors. Therefore, optimizing growth and understanding how management and environmental factors modulate seed yield and quality is critical for improving productivity and use of soybeans. This dissertation comprises six chapters (Chapter 1, Introduction, and Chapter 6, Conclusions). In Chapter 2, we explored metrics to characterize plant-to-plant spacing and its impact on yield across seeding rate and yield environments. We found that lack of plant-to-plant uniformity negatively impacted yield in both low- and medium-yield environments (<3 Mg ha-1) under low plant densities (<20 plants m-2), but with no effect at high yields (4.3 Mg ha-1). In Chapter 3, we developed an assessment of yield and seed quality allocation to mainstems and branches of an old and modern soybean genotype at varying row spacings. The modern genotype presented 50% greater yields, with a three-fold greater contribution from branches compared to the old genotype at narrow rows (<0.38 m). In addition, the modern genotype maintained protein levels despite high yields. In Chapter 4, we collected 235 on-farm seed and soil samples across 13 states of the United States (US). In addition, we collected management and weather data seeking to relate environment covariates to seed quality variation across regions. We predicted yield and seed oil concentration with better accuracy (R2 0.56 and 0.39, respectively) than protein concentration (R2 0.09). Yield and oil in the south were mainly limited by delayed planting dates that exposed early stages to high temperatures and shortened the season length. In the north, limitations were related to low temperatures during seed formation due to long maturity groups or late planting dates. Finally, in Chapter 5, we built a robust model for predicting oil (R2 0.54, MAE. 0.75%) and protein (R2 0.45, MAE 1.13%) concentration in all soybean fields of the US. We gathered satellite data on weather and soil, calculated the green chlorophyll vegetation index (GCVI) and derived the growing season length at a 1 x 1 km resolution. The outcomes of this study will assist farmers to develop near-real time predictions of soybean quality changes not only for segregation at field-scale but providing essential information for soybean exports.Item Open Access Influence of woody cover and other landscape characteristics on Northern raccoon (Procyon lotor) occupancy(2024) Durbin, CalebNorthern raccoons (Procyon lotor; hereafter raccoon) are generalist omnivores prevalent across North America. Raccoons occur in a variety of landscapes, especially those including woody areas. Increases in woody cover over the last century may have benefited northern raccoons. My first objective was to evaluate the influence of woody cover and other landscape drivers influencing raccoon occupancy in the contiguous United States. My second objective was to evaluate raccoon occupancy on a smaller scale within Kansas where grasslands are being lost to woody encroachment. To assess continental-scale patterns, I used camera trap data from Snapshot USA from 2019–2021. I analyzed data from 4,512 camera trap survey points and linked raccoon occupancy to land cover variables derived from the 2021 National Land Cover Database (NLCD; Dewitz 2023), 2023 National Hydrography Database (NHD; USGS 2023), and 2022 Rangeland Analysis Platform (RAP; Jones et al. 2018) tree layer. Occupancy models revealed interactions between the proportion of woody cover and the proportion of cropland land use within 1 km was most parsimonious. This effect of woody cover was positively influenced by the proportion of cropland. Occupancy was greatest when there was a proportion of woody cover at 0.10 and a proportion of cropland at 0.90 (βwoody = 0.632, SE = 0.119; βcrop = 4.121, SE = 0.715; βwoody:crop = 1.905, SE = 0.359). Additionally, raccoon occupancy is greater in areas closer to water (β = -0.722, SE = 0.0773). My results indicate woody cover may increase raccoon use, particularly in landscapes with cropland. Raccoons provide many positive and negative impacts to ecosystems and may benefit from altered cropland landscapes that provide minimal woody cover. Building on these findings, I aimed to find if similar patterns of raccoon occupancy are observed in woody encroached areas specifically within Kansas. The invasion of woody species is a major threat to grasslands and grazing operations. Woody species invasion not only poses challenges for grasslands and grazing operations but also contributes to a widespread decline in grassland bird species. The presence of woody plants may benefit nest predators like raccoons. My objective was to relate woody cover to raccoon occupancy in landscapes that can provide inference on how woody encroachment could alter raccoon distributions. I used camera traps and remotely sensed data to evaluate the influence of landscape composition on raccoon occupancy in Kansas. I conducted a stacked single-season occupancy analysis to identify relationships with site covariates. My most-supported single-season occupancy model included the additive influence of proportion of grassland within 1 km and distance to water and suggested that occupancy probabilities were lower at survey points with greater proportions of grassland and farther from water sources (βintercept = -1.89, SE = 0.25, βgrass = -1.072, SE = 0.22, βdistwater = -0.58, SE = 0.24; Fig. 2). Another competitive model included proportion of cropland within 1 km and proportion of woody cover within 1 km in an additive model and suggested that raccoon occupancy increased with woody cover and cropland (βintercept = -1.81, SE = 0.24, βcrop= 1.13, SE = 0.22, βwoody = 0.63, SE = 0.20). My results suggested a positive influence of woody cover, proximity to water, croplands, and a negative influence of grassland on raccoon occupancy. Consequently, raccoons may derive benefits from woody encroachment in Kansas. Conserving grassland areas may decrease raccoon occupancy and in doing so may reduce the use of areas that are important for landowners and other species and may then ease the human-wildlife conflicts that exist for this species with the potential for disease spread and damage to crops as well as benefit ground nesting birds.Item Open Access Efficacy of selected grain protectants on hulled Kernza®, dehulled Kernza®, and hard red winter wheat against two economically important stored product insect species(2024) Bhattarai, NatashaNo grain protectants are currently registered for use on the perennial grass, Thinopyrum intermedium (Host) Barkworth & D.R. Dewey (Poales: Poaceae), marketed under the trade name Kernza®. Phosphine is the only fumigant approved for treating perennial grasses. The efficacy of selected commercial formulations of grain protectants namely, deltamethrin, methoprene, methoprene plus deltamethrin, and spinosad on hulled and dehulled Kernza® were evaluated at labeled rates in the laboratory against the lesser grain borer, Rhyzopertha dominica (Fabricius) (Coleoptera: Bostrichidae) and rice weevil, Sitophilus oryzae (Linnaeus) (Coleoptera: Cucrculionidae). The concentrations of the protectants used were 0.5 and 1 ppm for deltamethrin, 1.25 ppm methoprene, 1.25 ppm methoprene plus 0.5 ppm deltamethrin as a combination product, and spinosad at 1 ppm. At each concentration of an insecticide, 100 g of dehulled Kernza®, hulled Kernza®, and hard red winter wheat were treated and placed in 0.47-L glass mason jars. Into each jar, 50 unsexed adults of mixed ages of R. dominica or S. oryzae were added, after which the jars were closed with metal lids fitted with wire mesh screens and filter papers. Jars with insects were placed in environmental growth chambers at 28ºC and 65% r.h. Mortality was assessed on independent samples after 7, 14, and, 21 days post-infestation. Mortality of the insects was expressed as percentage of the total insects exposed. In separate replicates, all three grain types were treated with the same protectants and infested as described above. These jars were checked after 42 days to count adult progeny produced. After determination of adult progeny production, the grains were passed through the Boerner divider® to get a working sample of 6 g for wheat and 1.5 g for hulled and dehulled Kernza®. From the working sample, the number of damaged and undamaged kernels were counted, and their weights were measured to determine grain weight loss and expressed as a percentage. The results showed that high mortality (> 90%) of R. dominica adults, low progeny production, and low grain weight loss were observed at 7, 14, and 21 days in dehulled Kernza® and hard red winter wheat at 0.5 and 1 ppm of deltamethrin. The mortality of S. oryzae adults was > 50% after 14 and 21 days of exposure to the two deltamethrin concentrations on all grain types. No or very low adult progeny numbers were observed in all grain types treated with both concentrations of deltamethrin. Low mortality (< 50%) of both insect species were observed in methoprene treated grains at all observation times. However, low adult progeny numbers were obtained in methoprene treated grains despite low mortality of adults. In methoprene plus deltamethrin treatments, the mortality of R. dominica adults was ≥ 93% in all grain times at all observation times, whereas the mortality of S. oryzae on all grain types and observation times ranged from 60 to 100%. There was no progeny production of R. dominica on all grain types, whereas S. oryzae mean progeny production at 7, 14, and 21 days ranged from 0 to 2.4 adults/jar; at 42 days adult progeny production ranged from 0.8 to 21.2 adults/jar. Grain weight loss was < 0.2 to 0.9% in treated grains exposed to R. dominica and S. oryzae. Spinosad caused 100% mortality of R. dominica adults and no progeny were produced, and no grain weight loss was observed on all grain types and observation times. In the case of S. oryzae, mean adult mortality at 7, 14, and 21 days in treated grains ranged from 87.2 to 100%, and progeny production and grain weight loss ranged 0 to 21.4 adults/jar and 0%, respectively. Spinosad at 1 ppm, deltamethrin at 0.5 and 1 ppm, methoprene and deltamethrin at 1.25 + 0.5 ppm were most effective grain protectants on Kernza® against R. dominica. In conclusion, spinosad at 1 ppm was the most effective grain protectant on Kernza® against R. dominica and S. oryzae. For dehulled Kernza the efficacy of tested grain protectants could not be satisfactorily gauged because of high mortality of R. dominica and S. oryzae adults in the control treatments.Item Open Access American sign language and facial expression recognition using YOLO11 object detection model.(2024) Lakkireddy, Pavan Kumar ReddyThis project addresses the critical need for effective communication solutions for the Deaf and hard-of-hearing community by focusing on the recognition of American Sign Language (ASL) gestures and facial expressions. Utilizing advanced deep learning techniques, specifically the YOLOv10 and YOLO11 object detection models, the study aims to develop a real-time system capable of accurately interpreting ASL signs and the associated facial cues. A custom dataset was created, consisting of high-resolution images that capture various ASL gestures along with corresponding facial expressions. These images were carefully manually annotated and preprocessed to ensure consistency and enhance model performance through data augmentation techniques. The dataset was then divided into training, testing, and validation sets for thorough model training and evaluation. The YOLOv10 and YOLO11 models were rigorously tested, demonstrating high precision and recall rates in ASL gesture recognition. Comparative analysis highlighted the advantages of each model, particularly in terms of their accuracy and computational efficiency. By offering a scalable and effective solution, this study significantly contributes to the fields of computer vision and communication accessibility, with the potential to enhance interactions between hearing individuals and the Deaf community. The outcomes of this research underscore the importance of technology in promoting inclusivity and improving communication for the Deaf and hard of hearing.Item Open Access Enhancing Soybean Phosphorus Management: Integrating Cover Crop Strategies and Targeted Fertilizer Placement and Timing(2024) de Oliveira Demarco, JovaniPhosphorus (P) management is essential for promoting soybean growth and maximizing productivity while also reducing the environmental risks associated with nutrient runoff. Cover crops (CC) are considered a promising tool in sustainable agriculture, offering benefits such as improved soil health, enhanced nutrient availability, and better soil moisture dynamics. This thesis investigates two key aspects of P management in soybean production: the influence of cover crops on P management and the effects of different P fertilizer placement techniques. The first study examined how CC impacts P management, soil moisture, and soybean productivity across multiple sites in Kansas during the 2022 and 2023 growing seasons. Using a randomized complete block design with a 3x2 factorial treatment structure, the study compared CC treatments with and without fertilizer application. Results showed that fall-planted triticale produced significantly more biomass than spring-planted oats, especially when fertilized, but increased biomass led to reduced soil moisture at the time of soybean planting. Despite variations in CC biomass and fertilizer use, no significant differences in soybean seed yield were observed across CC and fertilizer treatments. A critical biomass threshold of 2465 kg ha⁻¹ was identified, beyond which soybean yield declined under Kansas environment, highlighting the need for careful management of CC growth and termination timing. Although CC improved overall P accumulation in the soil, they reduced soybean P uptake at the V4 growth stage. Phosphorus application, however, improved P concentration in soybean trifoliate leaves at later stages. The second study focused on optimizing P fertilization techniques by comparing subsurface and broadcast P applications at different rates (45, 90, and 135 kg ha⁻¹) across nine study sites in Kansas. Early season results indicated that subsurface P placement improved P uptake, particularly in soils with low Mehlich-3 soil test P values, but this advantage was diminished by the time of R6 growth stage. No significant differences in P uptake or seed yield were found between subsurface and broadcast treatments at the end of the season. Seed yield analysis showed significant responses to P treatments at only two sites, suggesting that applied P rates frequently exceeded the requirements of the crop for optimal yield. These results emphasize the importance of aligning P application rates with soil P levels and indicate that subsurface placement could offer environmental benefits by reducing P runoff. Overall, this thesis highlights the importance of balanced P management strategies that integrate the benefits of cover crops and precise fertilizer placement to enhance soybean production and promote sustainable agricultural practices. The findings underscore the need for careful management of cover crops to balance biomass growth with moisture retention, as well as the importance of optimizing P application rates to prevent over-application and minimize environmental impacts.Item Open Access Optimizing last-mile logistics with drones: A simulation-based stochastic deep Q-learning approach(2024) Pratap, SuyashThis research addresses the optimization of last-mile logistics using unmanned aerial vehicles (drones), focusing on the challenges of limited battery capacity, diverse charging strategies, and efficient routing in a complex, stochastic environment. The study aims to enhance drone delivery operations through advanced modelling and reinforcement learning techniques. The inherent complexity of drone delivery systems, characterized by high-dimensional state spaces, continuous action spaces, and stochastic elements such as variable delivery demands and energy consumption, necessitates the use of advanced optimization methods. Traditional optimization approaches often struggle with such complex, dynamic systems. Therefore, this study employs deep Q-learning, a powerful reinforcement learning technique capable of handling high-dimensional state spaces and learning optimal policies in complex environments without explicit programming. A deep Q-learning model was implemented to optimize decision-making processes, with particular attention to the state and action space, reward function, and training procedure. The model's performance was evaluated based on its ability to improve operational efficiency and make optimal charging and routing decisions in real-time. A simulated drone delivery network comprising 14 nodes, including 2 origin nodes and 1 charging station, was created using Simio to test the model. This setup allowed for the capture of discrete timings for drone movements and charging decisions, informing the development of a stochastic model that accurately represents system uncertainties. Key findings reveal significant improvements in drone operation efficiency through the application of the deep Q-learning model. The model demonstrated the ability to learn complex strategies, balancing immediate rewards with long-term consequences in a way that would be challenging for traditional optimization methods. Analysis of charging behaviours provided insights into the trade-offs between fast and normal charging options and their impact on overall delivery performance, showcasing the model's capability to make nuanced decisions in a multi-objective optimization context. This research contributes to the field by offering a scalable and effective solution for managing the complexity of drone delivery networks, with potential applications across various logistics scenarios. The proposed approach demonstrates the potential for substantial improvements in last-mile logistics efficiency and reliability, highlighting the value of combining advanced optimization techniques with deep learning to address complex transportation challenges in dynamic, uncertain environments.Item Open Access Survival and progeny production of three economically important stored product insect species on hulled Kernza®, dehulled Kernza®, and hard red winter wheat(2024) Ahmad, FizraA variety of insect pests are responsible for postharvest losses of cereal grains. Stored product insect pests adversely affect grain quality and quantity of stored commodities. The lesser grain borer, Rhyzopertha dominica (Fabricius) (Coleoptera; Bostrichidae); red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae); and rice weevil Sitophilus oryzae (Linnaeus), are among the most common, serious and polyphagous stored product insect pests that feed on a variety of stored grains. Kernza®, Thinopyrum intermedium (Host) Barkworth & D.R. Dewey, is a low-input perennial cool-season intermediate wheatgrass, grown as a dual-purpose crop for high-quality grazing in the winter and for nutritious whole grain in the summer. No data are available on susceptibility of this novel grain crop to stored-product insect pests, although there are anecdotal reports that the grains from this crop are suffering insect related losses in storage. The aim of this study was to evaluate the survival and progeny production of R. dominica, T. castaneum, and S. oryzae on hulled Kernza®, dehulled Kernza®, and hard red winter wheat. Laboratory reared populations of these stored grain insect pests were introduced in all three tested grain types to record moisture contents (%), survival rate (%), progeny production, kernel damage, and weight loss. Separate experiments were performed for each insect species using completely randomized design (CRD), with 35 replications and seven observation times (7, 14, 21, 28, 35, 42, and 56 d) per grain type. The 7 to 28 d observation times determined survival of the three insect species on the grain types, while the 35 to 56 d observations were used to collect data on adult progeny production. In each replication, 25 adults of mixed sexes and ages were exposed to each of the grain types (50 g) in 150 ml round plastic containers under laboratory conditions of 28°C and 65% r.h. Adult survival (%) was assessed at 7, 14, 21, and 28 d post-infestation. Adult progeny production, kernel damage, and weight loss assessments were done on samples after 35, 42, and 56 d post-infestation. The moisture content during the duration of the experiment varied but the variation was marginal, despite some significant differences. The survival of all three insect species was significantly and consistently lower on hulled Kernza® compared to dehulled Kernza® and hard red winter wheat. Progeny production and weight loss results for R. dominica at 35 to 56 d varied with different grain types, but was generally lowest on hulled Kernza®. In T. castaneum experiments, the mean ± SE survival rate 28 d post-infestation period was significantly lower in hulled Kernza® (9.6 ± 2.4%) compared to dehulled Kernza® (100.0%) and hard red winter wheat (99.2 ± 0.8%). Hulled Kernza® exhibited complete suppression of T. castaneum progeny production in 35, 42, and 56 d samples. However, the mean ± SE kernel damage and weight loss percentage due to T. castaneum infestation was significantly lower i.e., 7.9 ± 0.9 and 1.1 ± 0.5, respectively, in hulled Kernza® compared to the other grain types in 56 d samples. The survival percentages of S. oryzae adults in hulled Kernza® decreased from a mean ± SE of 84.8 ± 2.9 at 7 d to 27.2 ± 4.1 at 28 d. Similarly, smaller numbers of adult progenies of S. oryzae were produced in hulled and dehulled Kernza® than that of hard red winter wheat. At 28 d post-infestation, no adult progeny of S. oryzae was recorded in both hulled and dehulled Kernza®, but a mean ± SE of 21.0 ± 5.4 number of adults were recorded in hard red winter wheat. The mean ± SE weight loss percentage resulting from S. oryzae infestation was in the following order after 56 d: hulled Kernza® (2.2 ± 1.1) < dehulled Kernza® (5.5 ± 0.5) < hard red winter wheat (6.5 ± 0.6). In conclusion, hulled Kernza® appears to be an unsuitable commodity for R. dominica, T. castaneum, and S. oryzae survival and progeny production compared to that of dehulled Kernza®. Therefore, storing Kernza® in its hulled form can be a practical approach to curtail postharvest losses and preserve grain quality, with additional studies warranted on further understanding the possible reasons for poor performance of the three species on hulled Kernza®.Item Open Access Social media influence on self-image and motivation for cosmetic and plastic surgery in Kuwait(2024) Alfares, MohammedThis thesis explores the influence of social media on body image perceptions and the motivations for cosmetic and plastic surgery (CPS) among individuals in Kuwait. With the increasing presence of Western beauty standards on social media platforms such as Instagram and Snapchat, this research investigates how these standards affect body dissatisfaction and intentions to undergo CPS in a society that balances traditional values with modern beauty ideals. The study uses the Theory of Planned Behavior (TPB) to analyze the role of attitudes, subjective norms, and perceived behavioral control in shaping CPS intentions within the Kuwaiti context. Other key variables included social media use, exposure to Western beauty standards, body image perceptions (both positive and negative), intentions to undergo CPS, beliefs regarding CPS, concerns and risks involved in CPS, and perceived subjective norms of CPS. A quantitative approach was employed, with data collected through an online survey (n=300). The sample was composed of 128 men, 137 women, and 23 who preferred not to identify. Descriptive statistics were calculated, including percentages, means, and standard deviations. Correlation and regression analyses were conducted to test the hypotheses and answer the research questions. The results show that frequent social media use was correlated with greater motivation for CPS. This was confirmed by significant correlations between social media use and attitudes (r = .172, p < .01), intentions (r = .195, p < .01), and beliefs regarding CPS (r = .211, p < .01). Exposure to Western beauty standards influences negative body image perceptions (r = .636, p < .01). Similarly, exposure to these beauty standards is positively correlated with attitudes toward CPS and intentions to undergo CPS, which was supported by the data (r = .178, p < .01 and r = .287, p < .01, respectively). Results also show that subjective norms on CPS intentions, that is, support from friends and family significantly increased motivation to undergo CPS (β = .293, p < .001). In testing the research questions results show significant differences in positive body image perceptions between those who had undergone CPS and those who had not. However, it was the subjective norms, especially social acceptance, and support from close circles, that significantly predicted intentions to undergo CPS (β = .293, p < .001). Lastly, identified beliefs about CPS and social motivations as strong predictors of CPS intentions, accounting for 40% of the variance in intention (R² = .403). This study demonstrates the significant role of social media in shaping body image and influencing cosmetic surgery trends in Kuwait. These findings suggest that culturally sensitive interventions are needed to promote healthier body image perceptions and reduce the negative psychological impacts of social media-driven beauty ideals.Item Open Access Using dynamic geometry software to examine its effects on student progression through the van Hiele levels(2024) Lehman, AndrewGeometry is a strand of mathematics that can benefit individuals in many areas of life. Test results, such as the TIMSS results, indicate that geometry is an area for growth among American students. With a need for students to better understand geometry, several academic standards have been created to direct geometry instruction in the United States. Aside from this growing need, advances in technology have been introduced to classrooms. Dynamic geometry software, such as GeoGebra, is an example of this technology. Does GeoGebra help students develop their geometric reasoning skills? This study used a mixed methods design to investigate the effects that GeoGebra has in the progression of fifth-grade students through the first three levels of the van Hiele theory.Item Open Access In vitro Screening of Sorghum Parental Lines for Digestibility as a Step Toward Development of Superior Sorghum Hybrids for Cattle Feeding(2024) Nasiu, FirmanFifty-one cultivars of sorghum parental lines were used in a series of in vitro assays to assess fermentation by mixed ruminal microorganisms as a step toward the development of superior sorghum hybrids. Sorghum grains were milled to pass a 1-mm screen of a cyclone mill, and subsequently incubated for 30 hours with a mixture of artificial saliva and strained ruminal contents from fistulated cattle. The study was designed as an incomplete randomized block design due to the large number of sorghum cultivars tested. Maximum cumulative gas production (K) and time required to reach half the maximum gas production were different (P<0.01) across sorghum cultivars. Similarly, terminal pH of cultures and in vitro dry matter disappearance (IVDMD) were also different among sorghum parental lines (P<0.01). Production of volatile fatty acids (VFA) also was assessed, and substantial differences among cultivars were noted for concentrations of propionate, iso-butyrate, isovalerate, valerate, and acetate:propionate ratio (P<0.01), but no differences were observed for concentrations of acetate, butyrate, and total VFA production (P>0.05). Furthermore, forty-eight sorghum cultivars of the parental lines from in vitro experiment were investigated to measure the gelatinization temperatures using differential scanning calorimetry (DSC). Results showed that onset temperature (To) ranged from 67.54 to 83.90⁰C, peak temperature (Tp) ranged from 74.94 to 98.35⁰C, and conclusion temperature (Tc) ranged from 74.53 to 105.32⁰C. In addition, gelatinization enthalpies (ΔHgel) were ranged from 1.06 to 6.49 J/g. Lower peak temperature and gelatinization enthalpies could indicate higher digestibility of sorghum grain tested. Variations in results demonstrated from both in vitro assay and DSC analysis suggest there is potential for development of sorghum cultivars that are more suitable than current cultivars as feeds for ruminants.Item Embargo Mathematical Modeling of Plant-Herbivore Interactions: Stability Analysis and Period-Doubling Bifurcation in a Modified Nicholson-Bailey Model(2024) Albayyadhi, Maram IbrahimA Nicholas-Bailey model was initially created with the purpose of examining the dynamics of the population between a parasite and its host. In 1935, Nicholson and Bailey proposed a model for predicting the interactions between Encarsia Formosa parasites and Trialeurodes vaporariorum hosts that focused on the interaction between parasites and hosts1. In the study of biological systems, these types of models, such as discrete-time equations, can be considered invaluable tools for studying the interactions between two species. This dissertation presents a refined iteration of the Nicholson-Bailey discrete host-parasite model in the first chapter 1. The research unfolds in several chapters. The initial chapter provides a comprehensive background and reviews pertinent literature. Subsequently, fundamental definitions of ordinary differential equations are expounded upon, elucidating key concepts in dynamical systems such as stability analysis, manifold theory and bifurcations. Moreover, essential results and theorems pertinent to the study are delineated. In the second chapter, an investigation scrutinizes the dynamics of the newly formulated host-parasite model, featuring three essential parameters confined to the first quadrant. A rescaling technique is employed to condense the model into a two-parameter format, capturing its dynamics. Notably, the model consistently manifests two boundary steady states, with the potential emergence of a third interior steady state under specific parameter conditions. Utilizing linearized stability analysis, thresholds for system stability are identified, distinguishing between stable and unstable regimes. Further exploration delves into the long-term stability of steady states and center manifold theory, particularly focusing on non-hyperbolic steady states and transitions from stable to unstable regions. The analysis extends to bifurcation scenarios, encompassing one or two parameter bifurcations based on varying parameter ranges. Period-doubling bifurcations, leading to chaotic behavior, are observed as eigenvalues cross critical thresholds. Numerical simulations substantiate the theoretical findings, reinforcing the validity of the analysis conclusions.
