Digital Commons Network^™

Investigating Molecular Rotation And Vibration With Ultrafast Electron Diffraction, Haoran Zhao

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Ultrafast electron diffraction (UED) has emerged since the late 20th century as a powerful technique for resolving molecular dynamics. With its high spatial and temporal resolution, UED can now measure rotational motion induced by linearly polarized, nonresonant, nonadiabatic laser pulses—one of the fundamental molecular degrees of freedom with broad applications. By combining laser-induced alignment with UED, new capabilities such as three-dimensional structural retrieval and isotope detection have been demonstrated, as discussed in Chapter 2.

In Chapter 3, three symmetry relations in the coefficients of rotational wave packets are identified and derived, reducing the computational cost of simulating asymmetric-top molecular alignment …

Electrical And Magnetic Properties Of Ferroic Oxide Thin Films And Free-Standing Membranes, Qiuchen Wu

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

This dissertation presents a comprehensive study of the electrical, magnetic, and transport properties of epitaxial ferroic oxide thin films and free-standing membranes, including ferroelectric PbZr_0.2Ti_0.8O₃ (PZT) and ferrimagnetic NiCo₂O₄ (NCO).

We evaluate the effects of electrostatic and mechanical boundary conditions on the ferroelectric properties of free-standing PZT membranes by transferring them on three types of base layers: the metallic Au, strongly correlated oxide La_0.67Sr_0.33MnO₃ (LSMO), and 2D semiconductor MoS₂. The coercive field and domain wall roughness depend sensitively on the metallicity and surface roughness of …

Ai-Enabled Robotic Nitrogen Management, Ankita Kalra

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Nitrogen management in corn agriculture faces economic and environmental challenges, motivating development of precision, site-specific solutions. This dissertation presents AIR-N (AI-Enabled Robotic Nitrogen Management), a novel system that integrates cloud-based artificial intelligence with an autonomous field robot (Flex-Ro) to optimize nitrogen fertilizer application in real time. The research is driven by the need to improve nitrogen use efficiency while reducing leaching and emissions.

Comprehensive architecture (Cloud-E) was designed using Amazon Web Services to ingest multi-modal agronomic data (soil sensors, crop reflectance, weather) and host machine learning models. A Random Forest-based model was trained on historical field data to predict spatially …

From Vision To Practice: Implementing An Instructional Model Through Teacher Experience And Leadership Support, Stefanie Novotny

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Implementing change in any organization is challenging. It requires careful planning, effective communication, and strong leadership. Principals provide support and empower stakeholders to take ownership of the change process. They create opportunities for others to contribute ideas, take on leadership roles, and drive innovation, fostering a culture of shared responsibility and collective action. Change leaders inspire creativity and encourage teachers to think outside the box, leading to the development of new ideas and processes that drive growth and success. This mixed-methods action research study investigated how teachers can enhance educational practices by implementing an instructional model to improve teaching strategies …

Evaluating Fall And Spring Planted Cover Crops For Integrated Management Of Herbicide Resistant Palmer Amaranth And Effect On Soil Health, Vipin Kumar

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Herbicide-resistant Palmer amaranth (Amaranthus palmeri S. Watson) pose a severe threat to agronomic crop productivity in the United States, including corn and soybean production in Nebraska. Therefore, there is an urgent need for diversified and sustainable management approaches. Integrating cover crops (CCs) with herbicide programs represents a promising strategy to achieve Palmer amaranth suppression, sustain crop yields, and contribute to long-term soil health in irrigated corn–soybean production systems in Nebraska.

A meta-analysis of 41 studies and 595 paired observations demonstrated that CCs reduced Amaranthus spp. density and biomass by 37–59% depending on the growing season, with grasses and mixtures …

The Long Arc Of Love: A Humanizing Meditation On Enduring Former Student–Teacher Relationships, Cara Morgenson

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

As 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 …

Synthesis And Study Of Stable Organic Radicals For Mri Contrast Agents And New Materials, Sabina Dhakal

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

The first part of this dissertation focuses on the design, synthesis, and characterization of a thermally robust S =1/2 phototetrazolinyl monoradical and the development of synthetic methodologies for a high-spin (S = 1) phototetrazolinyl diradical. Electrochemical studies of the phototetrazolium cation (precursor to the monoradical) revealed a remarkably narrow electrochemical band gap (Ecell ≈ 0.82 V), suggesting promising electrical conductivity. Thermal analysis of the monoradical demonstrated excellent stability, with the onset of decomposition at 232 °C. Building on the excellent thermal stability and promising properties for electrical conductivity of the monoradical, we developed two condensation-based synthetic routes that provide viable …

Integrating Chinese Tradition And Western Techniques In Jiang Zuxin’S Piano Works: A Study Of Temple Fair And Mountain Flower Collection, Qi Zhang

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

This document focuses on Jiang Zuxin’s two piano suites, Temple Fair and Mountain Flower Collection, examining how traditional Chinese musical materials interact with Western compositional techniques. Through close analytical readings of selected excerpts, combined with considerations of performance practice and modal context, the research demonstrates that Jiang systematically employs pentatonic collections and their modal configurations (gong, shang, jue/zhi/yu), along with certain altered tones (such as biangong and qingjue), as foundational pitch material. He also draws on folk songs, dances, and theatrical elements from traditional Chinese culture. At the same time, he simulates the timbres and idiomatic playing techniques of …

From Ghorer Golpo To Global Voices: Digital Storytelling As A Decolonial Pedagogy For English Language Learning In Bangladesh, Tamanna Sharmin Kabir

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

From Ghorer Golpo to Global Voices: Digital Storytelling as a Decolonial Pedagogy for English Language Learning in Bangladesh highlights how Digital Storytelling operates as a culturally sustaining and technologically supported approach within Bangladeshi undergraduate English education. Informed by my own navigation of Western and South Asian narrative traditions, the study responds to a longstanding challenge in English instruction: exam-focused, Eurocentric pedagogies often marginalize learners’ cultural identities and lived experiences. The research investigates how participants engaged with Digital Storytelling as a multimodal, technology-enhanced practice that supports language development, identity expression, and intercultural communication.

The study employed an arts-informed case study design …

Rainfall-Runoff Modelling In An Indonesian Humid Tropical Area Using Satellite-Based Precipitation Products, Noordiah Helda

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

This dissertation explores three rainfall-runoff models in the humid tropical regions of Indonesia using satellite-based precipitation products (SBPPs) and develops integrated machine-learning modeling frameworks. Several ground-based observations from BMKG (Badan Meteorologi, Klimatologi, dan Geofisika (also known as the Indonesian Agency for Meteorology, Climatology, and Geophysics)) stations across Indonesia (133−165 stations) are compared and evaluated against satellite products, indicating that GPM performs well, with R-squared values ranging from 0.54 to 0.76 and correlation coefficients ranging from 0.45 to 0.69, respectively.

In the Martapura Watershed, South Kalimantan, due to a lack of observational discharge data, streamflow was generated using the FJ Mock …

The Integration Of Western Compositional Techniques And Traditional Chinese Folk Music In The Piano Works Of Jianzhong Wang, Yingqi Wang

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

This document explores the method by which Jianzhong Wang (王建中) (1933–2016), a celebrated Chinese composer and pianist, integrates traditional Chinese folk melodies with Western compositional techniques in his solo piano works, including Western harmonic techniques and tonal language, contrapuntal and polyphonic textures, formal structure and thematic development, and the imitation of instruments and sounds. Introduced to Wang’s music during high school through the piece, “Embroidering the Golden Plaque” from Four Northern Shaanxi Folk Songs, the author reflects on the artistic challenges posed by Wang. Over years of study, an appreciation for Wang’s innovative fusion of Chinese folk elements and Western …

African American Women And Blogs: The Allure Of Culture-Specific Beauty Blogs, Kalari Flotree

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

The 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, …

Global, Continental, And Local Scale Paleoenvironmental Reconstruction Methods For Interpreting The History Of Miocene North America And The Great Plains, Willow Hue Nguy

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

The Miocene of North America is characterized by dynamic changes in herbivore communities, habitat composition, and global climate. Long-term cooling and drying trends influenced large changes in floral and faunal communities. The Great Plains, North America shifted from closed-canopy biomes to open-canopy biomes with C3-grasses to biomes with C4-grasses. This shift affected the herbivore communities as browsing-adapted ungulates were replaced by grazing-adapted ungulates. Much focus has centered on the Great Plains, so it is not well understood how the changes in biomes compare to other regions of North America. The models used for vegetation density indicate open-canopy biomes since at …

Public Perceptions Of Leadership Effectiveness In Ethiopia Over The Last Decade, Fikadu Reta Alemayehu

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Ethiopia is one of the largest countries in Africa, with a fast-growing economy, rich history, diverse agroecology, more than 70 languages, and a population exceeding 130 million. However, the country continues to face serious internal conflict, high malnutrition, and economic hardship, while the study of leadership effectiveness remains limited and lacks consistent longitudinal research. To help fill this gap, this study examined how public perceptions of leadership effectiveness and development outcomes changed in Ethiopia between 2013 and 2023, using Afrobarometer survey data. The analysis explored how citizens’ views about governance, wellbeing, and access to services evolved during a decade of …

Residential Hvac Installation Faults: Field Prevalence, Drivers, And Energy Impacts, Seyed Ali Rooholghodos

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Faults in residential comfort systems can have detrimental effects on the performance of the system, reducing the energy efficiency, affecting indoor comfort, and shortening equipment lifespan. Many of the faults occur at installation. However, there has not previously been a systematic and nationally representative study to indicate the prevalence of the faults, meaning the distribution of faults by fault type and fault intensity. Understanding true fault prevalence is essential to be able to identify derivers, and to assess the incremental electricity consumption of the new installation systems.

This study presents on-site data from 341 new central cooling systems—air conditioners and …

Investigating Preservice Elementary Teachers’ Stem Teaching Self-Efficacy And Goal Orientation, Derek Scott Cox

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

In the context of teacher education, self-efficacy and goal orientation can have an impact on one’s motivation, desire to improve, and maintaining a growth mindset in teachers. This study utilized an explanatory mixed methods design to investigate how and why preservice elementary science, technology, engineering, and mathematics (STEM) teachers’ confidence and views on competency changes after completing an array of courses built around integrated STEM.

Sixty-five preservice teachers participated in the pre- post-test quantitative data collection to determine changes in integrated STEM self-efficacy and achievement goal orientations (mastery-approach, mastery-avoidance, performance-approach, performance-avoidance). Data collection measures include Self-Efficacy for Teaching Integrated STEM …

Large-Scale Experimental Study On The Impact Of Air Cleaning & Ventilation On Indoor Air Quality And Student Illness-Related Absenteeism, Daud Nosham

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

This large-scale randomized experimental field study investigated the effect of portable air purifiers (PAPs) on classroom’s air quality and student’s illness related absenteeism. PAPs were installed in 317 classrooms from various school districts located in Eastern Nebraska. The classrooms were randomly assigned into four conditions: three treatment conditions (T1, T2 & T3) and one control condition (device without any filter). T1 was equipped with HEPA filters, T2 added Activated Carbon (AC) layer to HEPA, and T3 further integrated Germicidal Ultraviolet (GUV) alongside HEPA and AC filters. The measured variables were carbon dioxide (CO2), fine particles (PN2.5) and coarse particles (PNcoarse), …

Assessing Crop Rotation Productivity, Soil Health, And Fertility, And Economic Performance, To Enhance Semi-Arid High Plains Cropping Systems Sustainability, Ezequiel Maria Villamil

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Sustainable crop production in the semi-arid High Plains of Nebraska faces challenges from limited precipitation, high interannual variability, and economic risk. This dissertation investigates the long-term productivity, water use, soil health, and economic sustainability of dryland crop rotations, with emphasis on the role of pulses as alternatives to fallow.

Chapter 1 analyzes nearly three decades (1995–2023) of on-farm data from the High Plains Agricultural Laboratory (Sidney, Nebraska) to compare seven crop rotations, including wheat, corn, millet, sunflower, and field peas. Results showed that wheat–corn–fallow (W–C–F) consistently outperformed traditional wheat–fallow (W–F) and more intensified four-year rotations, providing the highest grain yields, …

Resources For The Beginning And Intermediate Jazz Educator: Reviews Of Modern Resources And Implementation In The Classroom, Bryan Canonigo

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

This document is a compilation and discussion of different modern jazz education resources geared towards beginning and intermediate students. It is intended for the younger high school jazz educator who may have just started their careers and are searching for new(er) resources to aid their teaching and rehearsal techniques. For the seasoned high school jazz educator, this document may suggest additions to their current lesson plans and/or updates to their current resource compilations and rehearsal practices. A primary goal of this document is to suggest ideas to aid these educators in teaching jazz music more wholistically, in small or large …

Development Of Databases For Glycan Utilization And Anti-Prokaryotic Defense In Microbiomes, Yuchen Yan

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Microbiomes in humans, animals, plants, and other environments are necessary components of the biosphere for global nutrient cycling and maintaining ecosystem balance. In particular, the gut microbiome plays an essential role in modulating human health through glycan utilization. Carbohydrate-active enzymes (CAZymes), CAZyme gene clusters (CGCs), and polysaccharide utilization loci (PULs) are key genomic features that determine microbial capacities for carbohydrate metabolism. Meanwhile, the arms race between phages and prokaryotes has led to the evolution of various anti-prokaryotic immune systems (APIS) in phages to counteract prokaryotic immune systems (PIS).

As bioinformatics methods used to analyze microbiome information advance rapidly, there is …

Advancing Precision Agriculture Through The Application Of Remote Sensing Technologies In Plant Health Assessment, Thomas Wilbur Davis

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Monitoring 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 …

Detecting Prescribed Fire, Haying And Grazing Events Via Remote Sensing To Create Grassland Disturbance Landcovers For The Ring-Necked Pheasant (Phasianus Colchicus), Megan A. Baldissara

School of Natural Resources: Dissertations, Theses, and Student Research

This dissertation developed disturbance detection models to fulfill the need for remote sensing landcover products describing grassland structure. The use of landcover products derived from remote sensing is increasing over time in pheasant (Phasianus colchicus) research. Such landcover, however, does not provide relevant pheasant structural habitat information (Chapter 1). Pheasants require tall, high-density grassland for nesting, tall grassland with medium density for brood rearing, and tall grassland for wintering. Time since disturbance can serve as a proxy for structure, as it shapes vegetation by removing biomass and resetting succession. Disturbance is easier to detect than structure with current …

On Bayesian Empirical Likelihood-Based Method For Complex Survey Data With Application To Non-Probability Sampling, Md Hasibur Rahman

Department of Statistics: Dissertations, Theses, and Student Research

This thesis develops a Bayesian empirical likelihood (BEL) framework for inference under complex survey designs and extends it to non-probability sampling. Parametric likelihood based methods are difficult to apply to complex survey data because the likelihood is rarely available in closed form. EL provides a flexible alternative by replacing the parametric likelihood with an empirical likelihood constructed from moment conditions. The proposed method first integrates empirical likelihood constraints with survey design features then extends BEL to non-probability sampling through selection models and design consistent restrictions. Posterior inference is carried out using a Metropolis–Hastings MCMC algorithm. A real-data analysis further illustrates …

Brands & Virtual Personas: How Virtual Influencer Types Impact Brand Awareness, Carol Calderon Ambelis

Department of Textiles, Merchandising and Fashion Design: Dissertations, Theses, and Student Research

As social media continues to shape how consumers interact with brands, virtual influencers (VIs) have emerged as a new type of digital celebrity. While previous research has explored how VIs contribute to brand image and awareness, there has been limited attention on how different types of VIs, both anime-like and human-like, affect consumer perceptions across different markets. This study examines how these two types of VIs impact relatability, aspiration, and brand awareness, with a focus on the differences between luxury and mass market. Using a within-subjects experimental design, this study recruited 574 participants with social media experience using MTurk. The …

Modeling The Greenland-Iceland-Faroe Ridge Using Integrated Geophysical Analysis, Zachary Clowdus

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

The Greenland-Iceland-Faroe Ridge (GIFR) is an area of significant geologic interest with anomalously thick crust related to enhanced melt generation from the interaction between the Mid-Atlantic Ridge and the Iceland hotspot. To the northeast of Iceland lies the Jan Mayen Microcontinent (JMMC), which is a continental fragment separated from Greenland during the opening of the Northern Atlantic. The overall extent of the JMMC, especially its southern boundary, remains poorly constrained. The crust beneath the GIFR is believed to be primarily of oceanic affinity. However, a recent discovery of felsic lavas in Iceland led to an alternative hypothesis that implies the …

The Urban Heat Island And Its Role In Shaping Convective Environments: An Observational Study, Benjamin W. Moll

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

The continued spread of urbanization and its well-documented effects on regional weather and climate necessitate further research. Urban environments are often warmer and drier than their rural surroundings. This trade-off between a warmer but drier environment could have a complex impact on deep convection and its initiation. Previous studies have noted significant changes in precipitation patterns around cities as well as changes to ongoing deep convection. Given the well-documented theory and past research, it is hypothesized here that urban areas have a significant impact on the PBL thermodynamics of convective environments. The urban heat island (UHI) component of the Micro …

The Role Of Peroxisomal Acot4 And Acot8 In Modulating Lipid Metabolism And Stress Pathways In Steatotic Hepatocytes, Sylwia Miekus

Department of Nutrition and Health Sciences: Dissertations, Theses, and Student Research

Metabolic dysfunction-associated steatotic liver disease (MASLD) is characterized by excessive lipid accumulation in hepatocytes and the development of lipotoxic stress that disrupts cellular homeostasis. Peroxisomal lipid metabolism plays an important role in maintaining acyl-CoA balance during fatty acid overload, yet the contribution of peroxisomal acyl-CoA thioesterases to early lipotoxic responses remains insufficiently understood. The aim of this study was to investigate the functional involvement of the peroxisomal enzymes acyl-CoA thioesterase 4 (ACOT4) and acyl-CoA thioesterase 8 (ACOT8) in hepatocyte lipid handling under acute lipotoxic conditions. An in vitro model of steatosis was established in AML12 cells through exposure to a …

A Strategic Audit Of Live Nation Entertainment: Industry Position, Competitive Dynamics, And Long-Term Growth Outlook, William H. Wooden Iv, Owen B. Crone, Reece L. Flores, Grace A. Schaefer, Eric M. Jacob, Sydney A. Beck

Honors Program: Senior Projects (Public)

Live Nation Entertainment is the dominant global leader in the concert and live events industry, supported by a vertically integrated model that spans artist management, concert promotion, venue operations, ticketing, and sponsorship. This strategic audit evaluates Live Nation’s internal strengths, external threats, competitive position, corporate governance, and long-term strategic prospects based on comprehensive analysis of company reports, industry dynamics, and market trends. Live Nation benefits from unmatched scale, global venue ownership, exclusive artist relationships, and the substantial network effects generated by Ticketmaster, which collectively create high barriers to entry and sustained competitive advantage. The audit also examines significant challenges such …

Evaluation Of Ramp Instead Of Forage During Grain Adaptation And Different Sorghum Varieties On Enteric Methane Production From Cattle, Jack T. Fort

Department of Animal Science: Dissertations, Theses, and Student Research

Two experiments were conducted to evaluate the use of RAMP (Cargill Corn Milling, Blair, Nebraska) compared with traditional forage-based adaptations on methane (CH₄) and carbon dioxide (CO₂) emissions, performance, and carcass characteristics. Experiment 1, 64 yearling British × Continental steers (initial BW = 423 ± 6 kg) were adapted using 100% RAMP (RAMP) or a traditional forage diet (CON; 43% forage) before transitioning 22 d to a common finishing diet containing 65.6% steam-flaked corn. Emissions were measured in paired replications using a two-chamber indirect calorimetry barn. During adaptation RAMP did not affect CH₄ production (g/d; …

Impact Of Constant Versus Variable Inclusions Of Modified Distillers Grains Plus Solubles On Feedlot Cattle Performance And Carcass Characteristics And Impact Of The Frequency Of Varying Modified Distillers Grains Plus Solubles Inclusions In Feedlot Diets On Performance, Carcass Characteristics, Feeding Behavior, And Ruminal Ph Of Finishing Steers, Paige M. Madison

Department of Animal Science: Dissertations, Theses, and Student Research

Inconsistent availability or supply of distillers grains (DGS) can cause more variation in DGS inclusions throughout the feeding period. Two feedlot experiments evaluated the effects of varying inclusions of modified distillers grains plus solubles (MDGS) in feedlot diets. Beef steers (n = 400; initial BW = 287) were used in a 2 × 2 + 1 factorial experiment with treatments including: control with no MDGS compared to 2 inclusions (10% and 25%) of MDGS diet inclusions fed consistently or variably. No interactions were observed between MDGS consistency and inclusion for any performance or carcass characteristics (P > 0.10), so …