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Updating Rainfall Zones and Intensities in Nebraska for Improved Design of Non-bridge-sized Drainage Structures
No full textThis study assesses the effectiveness of precipitation zones and Intensity-Duration-Frequency (IDF) curves used by the Nebraska Department of Transportation (NDOT) for designing drainage structures. Twenty stations were selected for the analysis of revised IDF curves out of forty-two stations. Datasets have been considered from the National Center for Environmental Information (NCEI). By Comparing the new curves with existing ones, the study efforts examine the frequency, duration and severe rainfall. The results show that the IDF curves for various zones and stations varied noticeably from one another. Also, noticed that Zone A and B shows lower rainfall intensities in short to medium duration. While, Zone C shows higher rainfall intensities short to medium duration. The variation can be seen by a verification using ATLAS-14 IDF curves and historical data, suggesting the necessity for an updated methodology. Additionally, this study used the Kriging and Inverse Distance Weighting (IDW) approach to analyze rainfall spatially. The study employed the k-means clustering technique to identify if the new cluster was considered to be a rainfall zone. The studies show the development of three spatial zones and a new IDF is created based on this clustering analysis. The research being conducted provides crucial information to ensure the sustainability of the Nebraska transportation system and increase the accuracy of hydrological assessments
Analyzing Reciprocating Piston Expander Performance in Small-scale CAES Considering Expansion Mismatch and Residual Mass Losses
No full textEnergy storage (ES) has become an essential element of modern energy systems, particularly with the rapid growth of renewable energy sources. While these sources are central to global decarbonization efforts, their intermittent nature creates significant challenges for both grid operators and end users. To address these challenges, a wide range of storage technologies have been developed ranging from large utility-scale to small behind-the-meter units. Among these, Compressed Air Energy Storage (CAES) stands out for its long lifespan, low storage cost per unit of energy, and ability to provide both electricity and thermal energy. However, small- and micro-scale CAES systems, unlike large-scale units that employ caverns, rely on storage tanks which significantly increases the investment required for such systems. Therefore, integrating CAES systems into existing infrastructures has been explored to reduce capital costs. One such example is the use of building foundation piles, where storage volume and maximum allowable pressure are dictated by structural constraints rather than energy optimization. These limitations reinforce the importance of carefully designing the expander and discharge strategy to maximize useful work output.
This study addresses a critical and previously unexplored question: How does a reciprocating piston expander (RPE) perform when operated under free-flow discharge, without a pressure regulating valve (PRV), and connected to a finite-size storage tank that mimics building foundation piles? To answer this question, RPE performance under free-flow discharge is modeled based on thermodynamic fundamentals, with correlations developed to calculate overall work output under both the free-flow and throttled flow discharge. Notably, the analysis explicitly incorporates expansion-ratio mismatch and residual-mass losses, two loss mechanisms that remain understudied in RPEs. By directly comparing the two discharge scenarios, this dissertation addresses whether the inclusion of a PRV is justified in small-scale systems.
Through modelling the free flow performance and the development of theoretical correlations for estimating overall useful work, it was determined that the free-flow strategy has a consistent superior performance over using a PRV in the range of parameters studied. Moreover, the developed correlations show that overall useful work is a function of four distinct parameters: 1. Storage tank volume, which is shown to act as a linear scaling factor, 2. Storage pressure, which has a linear effect under throttled flow and is nearly linear in free flow, 3. Stopping pressure, which is the PRV setpoint pressure in the throttled valve and final pressure in the free-flow scenario, and is shown to have a quadratic correlation with overall work output, and 4. The expander geometry, which by itself is divided into the expander cylinder’s maximum volume, the crank-to-rod ratio, and the clearance volume ratio. Geometric ratios have modest influence: a higher crank-to-rod ratio and a smaller clearance ratio both improve performance, with clearance having a larger effect. Furthermore, it is proven that the cylinder’s maximum volume does not impact the performance of the expander. These insights suggest that system designers should prioritize pressure optimization, and, where stability and control requirements allow, adopt free-flow discharge to maximize efficiency in small-scale CAES.
Advisor: David Yuil
Beyond Being Famous for Being Famous: A Phenomenological Approach to Understand the Leadership of Kim Kardashian
No full textThis phenomenological study explores the meaning of the influence of Kim Kardashian on millennial women based on their followership on social media platforms, exploring the intersection of leadership studies, celebrity capital, and popular culture. Social media has democratized influence and transformed power dynamics through access and immediacy of information allowing the celebrity-turned-influencer-turned leader Kim Kardashian to build a billion-dollar empire spanning entertainment, and the media, beauty, fashion, and retail industries. Through qualitative interviews and analysis with 11 millennial women, this research sought to understand the meaning of her influence in their lives.
Explored through the theoretical frameworks of French and Raven’s bases of power, Barbuto’s influence triggers, and Driessens’ celebrity capital theory, four themes emerged. First, Kardashian generates a sense of belonging and social capital by ensuring participants are current on popular culture and trends in conversations with their peers. Second, content posted to her social media platforms influence consumer behavior and self-perception, specifically with body image and online shopping behavior. Third, Kardashian’s power is primarily acknowledged from her legitimate position in society, however her wealth and perceived political alignments prompts ethical and moral concerns in tandem with values misalignment for the study participants. Lastly, participants demonstrate a disconnect on Kardashian and her leadership. Participants assigned traditional leadership characteristics to Kardashian including vision, strength, business acumen, and influence, however, many hesitated to assign the label of “leader” to her. Instead, they contextualized her leadership within specific elements of her life or rejected the designation completely.
The findings showcase how digital platforms have evolved influence beyond traditional organizational and social-movement contexts, highlighting a complex experience between inspiration and criticism, relatability and aspiration, feminism and capitalism. This dissertation contributes to leadership scholarship by expanding the understanding of power and influence across digital spaces to demonstrate how celebrity capital functions as social currency to generate target compliance. This research challenges traditional leadership studies’ frameworks to integrate influencer culture and the power over follower behavior, beliefs, and consumption patterns, while prompting questions of authenticity, relatability, ethics of wealth, and the positioning of leadership in a media-saturated society outside the walls of an organization.
Advisor: Heather Aki
African American Women and Blogs: The Allure of Culture-specific Beauty Blogs
No full textThe purpose of this qualitative, multi-case study was to explore the identity-related dress and appearance management implications of culture-specific beauty blog readership. The study was informed by three research questions: (a) Why and how do African American women seek out culture-specific beauty blogs? (b) What roles do African American women assume while engaging with culture-specific beauty blog communities? (c). How do African American women use culture-specific beauty blog content to inform identity-related processes of appearance management and dress?
The sample of this multiple-case study included nine participants, each representing a distinct case. Data were collected through individual, semi-structured, in-depth interviews, field notes, and a process of data mining the culture-specific beauty blogs introduced during the interviews. Interviews were transcribed verbatim, analyzed, and coded for themes.
Data analysis revealed that study participants sought out culture-specific beauty blogs because they were interested in locating beauty media that featured Black representation of beauty and cultural ideals. The Natural Hair Aesthetic was a key driver of interest for study participants, as they sought information to adapt the aesthetic. Participants overwhelmingly identified an online search engine query for a beauty-related interest as their original method of connection to culture-specific beauty blog content.
All participants reported that, following their initial introductions, they regularly returned to culture-specific beauty blogs for content of that type. During those visits, participants reported only engaging with their chosen blogs from the perspective of a viewer. That is, although blogs feature optional two-way communication, participants elected not to engage in online dialogue with bloggers or members of blog communities. Instead, some reported discussing culture-specific beauty blog content with friends or family members offline.
Finally, data revealed that a large majority of study participants routinely visited culture-specific beauty blogs for content related to their natural hair. Beauty resources for hair care and styling, such as step-by-step tutorials and product reviews, were identified by participants as resources that they regularly referenced and used in processes of appearance management.
Advisor: Mary Alice Cast
Advancing Precision Agriculture Through the Application of Remote Sensing Technologies in Plant Health Assessment
No full textMonitoring plant health, including nutritional status assessment, is an important component of crop management decisions. This doctoral document addresses the use of agricultural remote sensing through focused investigations of plant disease detection and nutrient status assessment technologies that advance precision agriculture. The first chapter provides a comprehensive overview of remote sensing technologies in agriculture and examines current capabilities, limitations, and future directions. The final two chapters address studies that evaluated the virus-nitrogen interaction in wheat and compared methods to determine the nitrogen status of midseason field corn.
The first study evaluated the wheat streak mosaic virus (WSMV) × nitrogen interaction in early growth stage winter wheat. It integrated traditional plant pathology assessments with hyperspectral remote sensing to identify nitrogen levels that either suppress or exacerbate WSMV symptoms and virus titer and determine which vegetation indices better detect the interactive effects of nitrogen and virus infection. It was observed that adequate nitrogen partially maintained chlorophyll levels in infected plants and delayed symptom development. The Chlorophyll Red Edge (Clred_edge) index demonstrated the best sensitivity in detecting virus × nitrogen interactions. Under sufficient or high nitrogen supply, Clred_edge detected spectral changes associated with virus presence before visible symptoms became apparent. This suggests that virus effect on red edge reflectance is at least partially independent of nitrogen-induced chlorophyll variation, potentially allowing early detection of infection under conditions of adequate nutrition.
A second study investigated the accuracy of real-time nutrient assessment technology through comparative analysis using visual assessment, the Leaf Evaluated-Nutrient System (Picketa LENS system; 2024 Corn Model), and conventional laboratory tissue sampling methods. For nutrient assessment, each method provided unique insights into plant nitrogen status but also revealed some limitations. Visual assessment effectively identified severe nitrogen deficiency through characteristic leaf firing symptoms. The Picketa LENS system showed similar overall trends in nutrient concentration measurement compared with the conventional laboratory method. The advantage of Picketa rests in the capability of immediate assessment of nutrient status; however, continued development and validation will be required.
Advisors: Gary Hein and Jeffrey Bradsha
The Long Arc of Love: A Humanizing Meditation on Enduring Former Student–Teacher Relationships
No full textAs the title suggests, this is a humanizing meditation on enduring relationships beyond the classroom construct of student-teacher, with a theoretical framing that braids strands of critical theories and pedagogies to consider critical love, authentic caring, and humanization as a liberatory and justice-oriented framework (see del Carmen Salazar, 2013; Freire, 1970/2020; hooks, 1994; Sealey-Ruiz, 2020, 2021; Valenzuela, 1999). In the spirit of multiple and eclectic methods (Nader, 1972), the methodological framing braids (1) critical autoethnography as feminist method (Adams et. al, 2015; Boylorn & Orbe, 2014; Ettorre, 2017), (2) portraiture (Lawrence-Lightfoot & Hoffman Davis, 1997), and (3) narrative epistemology in the tradition testimonio, (counter)stories, feminist narrative writing, and a genre-bending turn in qualitative research. Inspired by the theoretical and embodied writing of women thinkers and scholars like bell hooks, Gloria Anzaldúa, and Audre Lorde, the author centers feminist commitments to women\u27s bonding, women\u27s speech, dialogic relationality, and (counter)storytelling. Central to this work is hooks\u27 (1984; 1992) notion of theorizing as a liberatory practice—that theory itself can emerge from lived experience and relational knowing as an act of resistance and freedom. The dissertation enacts this principle by engaging participants not as research subjects, but as co-theorists in the ongoing work of meaning-making.
The author first met the women who are central to this research–now as former students, mentees, co-theorists, and friends–in grade 9–12 English Language Learner (ELL) classrooms in Lincoln, Nebraska, a midwestern site of refugee resettlement. As our relationships evolved after graduation, roles shifted into collaborative partnerships that resist fixed categories. This dissertation critiques traditional research boundaries and advances narrative, dialogue, and relationship as rigorous forms of knowledge production and as feminist, relational, and liberatory practice rooted in co-created meaning-making.
Situated within the liminal realm between social sciences and humanities research, the entire dissertation extends that sense of liminality to format, conceptual and methodological framing, and content; it is informed by categories and resistance to their intrinsic reductionism. The study meditates upon the long arc of love and reciprocity of care that evolves after the normative endpoints of schooling, exploring the questions of (1) Who am I to them? (2) Who are they to me? and (3) What is reciprocity that emerges from this dynamic, enduring connection? This evolution resists essentialized classification; as one subject notes, Americans love putting things in categories. The project wrestles with this impulse toward categorization and, in doing so, with the constraints of the classical dissertation format itself. It offers both a methodological and ethical contribution to reimagining educational inquiry into relational pedagogies as a liberatory, collaborative, and profoundly human act.
Advisor: Edmund Haman
Nebraska Invasive Species Council, 2025-2027 Adaptive Management Plan
No full textNebraska Invasive Species Council, 2025-2027 Adaptive Management Pla
Creating Meaningful Proportionality Review: Expanding the Universe of Cases for Nebraska’s Capital Punishment Scheme
No full textAnalyzes the Nebraska Supreme Court’s proportionality review to show why Nebraska should expand its universe of “same or similar” cases to include all first-degree murder convictions. Discusses the federal case law relating to the death penalty and how Nebraska statutes responded. Considers how various states reacted to the Court’s decision in Pulley v. Harris. Offers a new perspective on Nebraska’s proportionality review for death sentences to show why a more expansive universe of cases will allow Nebraska to achieve true proportionality in its death penalty scheme
Contributors and Acknowledgments for \u3ci\u3eRoots of Justice: A History of Race and Racism in Nebraska\u3c/i\u3e
No full textPaul A. Olson, M. Dewayne Mays, Gabriel Bruguier, Kevin Abourezk, Preston Love, Jr., with Adam Fletcher Sasse, Heather Fryer, Sharon Ishii-Jordan, Emira Ibrahimpašić, and Julia Reilly
Acknowledgement