Digital Commons Network^™

Mass Effects On Energy Transfer Paths In Nonlinear Vibrating Systems, Manal Mustafa

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

This dissertation examines the role of mass in nonlinear systems, uncovering its role in enabling passive energy redistribution and robust vibration control in both idealized and real-world structures. Focusing on a strongly nonlinear two-degree-of-freedom system, it investigates how changes in mass ratio influence the dynamics of energy transfer, nonlinear normal modes (NNMs), and dissipation behavior.

A number of significant contributions are introduced in this work beginning with the introduction of the frequency-energy-peaks (FE-pks) plot, a novel tool that visualizes how energy flows through the system, revealing transient resonance orbits, internal resonance effects, and effectively capturing the different nonlinear phenomena with …

Study Of Ai Applications In Biomedical Data Acquisition, Communication, And Analysis: Cest Mri Acceleration And Ecg Transmissions, Adarsha Bhattarai

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

This dissertation investigates the application of artificial intelligence in biomedical data acquisition, communication, and analysis to advance neurological research and to enable the early detection of cardiovascular conditions. Despite significant advances in imaging and physiological modalities, challenges persist. Imaging modalities, such as the chemical exchange saturation transfer magnetic resonance imaging (CEST MRI) technique are challenged by a prolonged data acquisition time and high operational costs. In addition, physiological modalities such as electrocardiogram (ECG) sensors face constraints in providing uninterrupted signal monitoring which is crucial for the timely detection of premature cardiac abnormalities. The primary goal of this work is to …

The Career Resilience Of Women Of Color Amidst Intersectional Racism-Sexism In The Us: A Consensual Qualitative Study, Hannah Ahmad Ridzuan

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

Women of color have historically and presently experienced both sexism and racism on interpersonal, institutional, and cultural levels (Sue et al., 2007). While discrimination based on racial-ethnic and gender identities has by far the most extensive literature base (Duffy et al., 2016), literature on the development of women of color career resilience is not as expansive. Informed by the Psychology of Working Theory (PWT) (Blustein, 2006; Duffy et al., 2016), the intersectionality framework (Crenshaw, 1989; Collins et al., 2021), and critical consciousness (Freire, 1971; Quiñones-Rosado, 2020), this consensual qualitative research (CQR; Hill, 2006) explored how women of color in the …

On Kernels And Antiderivatives Of Nonlocal Derivatives, Alex John Heitzman

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

Nonlocal operators are mathematical operators taking functions to other functions f → Df , where to evaluate the operator Df at a point x, one must know the value of f in some region around x, and that region cannot be arbitrarily small. Nonlocal derivatives are like derivatives in that they measure the deviation of a function f(z) from f(x) when z is close to x. In this thesis, we will study nonlocal operators of the form

D_kf(x) = [integral]_Ω [f(x) …

Flooding: Risk Assessment And Its Interaction With Population & Environmental Health, Shivendra Srivastava

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

Flood events have significant implications for both population and environmental health. This dissertation aims to explore flood risk and its interaction with humans and the environment. The key questions addressed in this dissertation include improving the existing flood risk framework to better assess population vulnerability and associated risk. Additionally, it explores how interactions among risk components vary across spatial scales and regions, and how these variations influence overall flood risk. The dissertation also investigates how to design a vulnerability component specific to flooding within flood risk estimation. Finally, it answers whether flood-specific vulnerability differs for a population compared to vulnerability …

From Classroom To Content Creator: Leadership Practices And Identities Of Female Science Teachers On Tiktok, Rachel M. Benzoni

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

This qualitative multiple case study investigates how four secondary science teachers use TikTok to advocate for science education and how content creation shapes their professional identities as leaders. Using interviews and video content with a framework integrating constructivist leadership, Leader Identity Construction Theory (LICT), and the Social Change Model (SCM), findings show participants enacted leadership outside formal roles through distributed and relational practices leveraging social media's affordances. Five themes emerged from the analysis: (1) Reconceptualizing Teacher Leadership on Social Media, (2) Leadership Through Equity-Driven Practice, (3) Constructing and Leading in Online Professional Learning Communities, (4) Forming and Negotiating Identities in …

“Self-Compassion Has To Be The Heartbeat Of How I Move Through Life”: A Mixed Methods Study Of Family Caregiver Emotional Well-Being, Sarah O. Rasby

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

Often referred to as “hidden patients,” family caregivers endure numerous physical, emotional, psychological, and social hardships due to the demands of caregiving, which often results in their own needs going unmet. With the projected 61.3 million of the baby boomer generation entering the long-term care phase by 2029 along with a mass shortage of professional caregivers post-pandemic, more and more family members are expected to fill in for the role of care without sufficient access to support services (Pollard & Scommegna, 2014; Smith & Chang, 2016). An exploratory, mixed-methods study using a three-group intervention design was utilized to investigate the …

Honoring Childhood Agency In Developmental Research: Best Practices, Applications, And Insights, Amanda N. Howery, Olivia J. Lashley, Hanna R. Wright, Julia L. Williams, Olivia K. Nomura, Eline Lenne, Elizabeth K. Wood, Hanna C. Gustafsson, Elinor L. Sullivan

School of Social Work Faculty Publications and Presentations

Pediatric research requires caregivers to provide informed consent on behalf of their children. While not a formal requirement for children under the age of seven, it is important to involve child participants in the assent and decision-making processes in developmentally appropriate ways. This is especially important in longitudinal research, where the extent to which a developing child understands study tasks evolves over time. Although there is consensus that assent procedures are important and necessary, limited resources synthesizing strategies for pediatric researchers to encourage positive and respectful research experiences for young children exist. We describe methods used in an ongoing longitudinal …

A Comprehensive Look At Pudg-R21: Stellar Population And Kinematics Of A Globular Cluster-Rich Ultra-Diffuse Galaxy In The Perseus Cluster, Arsen Levitskiy, Duncan A. Forbes, Jonah S. Gannon, Anna Ferré-Mateu, Aaron J. Romanowsky, Jean P. Brodie, Warrick J. Couch, Lydia Haacke

Faculty Research, Scholarly, and Creative Activity

We present the analysis of the stellar populations and kinematics of the globular cluster (GC)-rich ultra-diffuse galaxy (UDG), PUDG-R21, using spectroscopic observations obtained with the Keck Cosmic Web Imager. The recessional velocity is measured to be 5536 ± 10 km s⁻¹, confirming its association with the Perseus Cluster. The galaxy exhibits mild rotation of 15.6 ± 10 km s⁻¹ and a stellar velocity dispersion of 19.4 ± 3.5 km s⁻¹ within the galaxy effective radius. From this, we infer a dynamical mass of Mdyn = 9.3 ± 3.3 × 108 M☉. Based on a halo mass …

Kinematic Confirmation Of A Remarkable Linear Trail Of Galaxies In The Ngc 1052 Field, Consistent With Formation In A High-Speed Bullet Dwarf Collision, Michael A. Keim, Pieter Van Dokkum, Zili Shen, Harrison Souchereau, Imad Pasha, Shany Danieli, Roberto Abraham, Aaron J. Romanowsky, Yimeng Tang

Faculty Research, Scholarly, and Creative Activity

A unique linear trail of diffuse galaxies was recently identified in the NGC 1052 field. This trail includes the remarkable, ultradiffuse galaxies DF2 and DF4, which lack dark matter and host unusually luminous globular clusters. It has been proposed that the trail formed via a high-speed collision between two gas-rich dwarf galaxies. This scenario predicts that the trail galaxies are kinematically connected and follow a specific trend in radial velocity as a function of position, based on the known velocities and positions of DF2 and DF4. To test this hypothesis, we measured radial velocities for seven additional galaxies on the …

Dynamic Mode Decomposition Of Geostrophically Balanced Motions From Swot Cal/Val In The Separated Gulf Stream, Takaya Uchida, Badarvada Yadidya, Karl E. Lapo, Xiaobiao Xu, Jeffrey J. Early, Brian K. Arbic, Dimitris Menemenlis, Luna Hiron, Eric P. Chassignet, Jay F. Shriver, Maarten C. Buijsman

Faculty Research, Scholarly, and Creative Activity

The decomposition of oceanic flow into its geostrophically balanced and unbalanced motions carries theoretical and practical significance for the oceanographic community. These two motions have distinct dynamical characteristics and affect the transport of tracers differently from one another. The launch of the Surface Water and Ocean Topography (SWOT) satellite provides a prime opportunity to diagnose the surface balanced and unbalanced motions on a global scale at an unprecedented spatial resolution. Here, we apply dynamic-mode decomposition (DMD), a linear-algebraic data-driven method, to tidally-forced idealized and realistic numerical simulations at submesoscale-permitting resolution and one-day-repeat SWOT observations of sea-surface height (SSH) in the …

How Developers Use Type-System Related Programming Language Features, Samuel W. Flint

School of Computing: Dissertations, Theses, and Student Research

Optional type annotations are a popular feature of programming languages that allow developers to omit explicit type information in code while, in some cases, retaining many of the benefits of static typing, such as in-code documentation, improved detection of type errors, or enforcement of code properties. However, how developers use and understand optional type annotations is not clear. The focus of this dissertation is to understand the use and comprehension of optional type annotations.

Optional type annotations are examined through four lenses: first, by examining the evolution of usage in a statically typed programming language (Kotlin, the default language for …

The Earliest University Of Nebraska Graduate Degrees, 1886-1909, Mark A. Griep

Mark A. Griep Publications

This list of the earliest graduate degrees awarded by the University of Nebraska (NU) in Lincoln was assembled to learn about the university’s research activity that preceded its admission to the prestigious Association of American Universities (AAU) in 1909.

Pseudo-Soft-Switching Switched-Capacitor Drive Circuits For Small-Scale Dielectric Actuators, Yanqiao Li

Dartmouth College Ph.D Dissertations

Applications including micro-robotics and haptics have motivated extensive exploration of dielectric actuators due to their high bandwidth and high efficiency at cm and mm scales. To maximize their benefits, dielectric actuators, including piezoelectric and electrostatic actuators, typically require high driving voltages, ranging from 100V to several kV. Generating such high driving voltages presents a challenge for drive circuits, particularly when powered by a small battery. Dielectric actuators are predominantly capacitive in most circumstances, necessitating the drive circuits to deliver and recover reactive energy for efficient operation. In some applications, such as micro-robotics, the drive circuits may need to have a …

Opportunistic Short-Term Water Uptake Dynamics By Subalpine Trees Observed Via In Situ Water Isotope Measurements, Matthias Sprenger, Stefan Seeger, Max Berkelhammer, Nathaniel A. Bogie, Raymond J. Hess, Wendy S. Brown, Sylvain Kuppel, James Knighton

Faculty Research, Scholarly, and Creative Activity

Variations in tree water sources are important to understand in semi-arid ecosystems because climatic shifts towards lower snowpack and increased drought affect water availability in subalpine forests of the western US. Here, we use daily in situ measurements of stable isotopes (²H & ¹⁸O) in soil and tree stem water, soil matric potential and sap flow to study tree water uptake dynamics. We instrumented three soil profiles down to 90 cm, as well as three aspen and engelmann spruce trees near Gothic, Colorado, in the East River watershed. We observed the fate of natural isotopic variations in …

Bulloch County National Register Of Historic Places Collection, Zach S. Henderson Library Special Collections

Finding Aids

Spanning 1970 to 1997, the collection contains materials regarding the application process for various Bulloch County properties to the National Register of Historic Places. Materials include official application paperwork, along with correspondence between various officials and property owners regarding processing, status updates, or requests for more information. Photographs of properties and supplemental documents such as genealogical records, newspaper clippings, and written narratives surrounding the development of the properties are also included.

Find this collection in the libraries' catalog.

Exploring The Long-Term Impact Of Dating And Family Violence On American Indian Youth And Adults: The Role Of Belongingness In Moderating Negative Effects, Racheal M. Killgore

All Graduate Theses and Dissertations, Fall 2023 to Present

Exposure to violence during childhood and adolescence is an important issue, particularly among Native Americans, who experience violence at higher rates compared to other racial/ethnic groups. This early exposure to violence can significantly affect future physical and mental health outcomes—including depression, substance abuse, suicide attempts, obesity, and premature death—while also shaping subsequent relationships in adulthood. Though widely studied in the general population, research focused on American Indians is lacking, with cultural contexts and factors uniquely shaping the experiences of those affected. In AI/AN communities, belongingness is important for well-being and, as such, is a relevant cultural factor that calls for …

Quantifying The Sensitivity Of Land Use Land Cover Metrics Through Simulation Techniques, Haley Burger

All Graduate Theses and Dissertations, Fall 2023 to Present

As human activities and climate change continue to reshape our landscape, understanding how land use changes over time is becoming increasingly important. Accurate ways to track and analyze these changes are essential for governments, businesses, and communities to make informed decisions. Monitoring agricultural land is particularly critical, as shifts in land use can impact food production and environmental pollutants. One of the primary tools used in the United States to monitor agricultural land is the Cropland Data Layer (CDL), an annual map created by the United States Department of Agriculture (USDA) from satellite images. While the CDL is highly accurate, …

So Much Cooler Online: Social Media Usage By Agricultural Educators In Secondary Sbae Classrooms, Saydee C. Longhurst

All Graduate Theses and Dissertations, Fall 2023 to Present

Social media has become a powerful tool in education, helping teachers connect with students and share information in new ways. Agricultural educators are using platforms like Facebook and Instagram to promote agricultural literacy and engage students in an online format. This study explores how high school agriculture teachers use social media, what challenges they face, and how comfortable they are using it. Through an online survey and analysis of social media engagement data, this research highlights the benefits and personal evaluation educators have when using these platforms. The results show that while social media helps teachers share resources and connect …

Optimal Distributed Energy Resource Control And Scheduling In A Microgrid Framework, Timothy M. Dodge

All Graduate Theses and Dissertations, Fall 2023 to Present

As we use more renewable energy, such as solar power, and add new devices, such as electric vehicle chargers and battery storage, to our buildings, the management of electricity becomes more complex. These local energy sources and devices can form small "microgrids" that need careful coordination to work efficiently with the main power grid. The system figures out the best times to use, store or charge different devices (such as batteries and EVs) to avoid costly, high electricity demand spikes and help stabilize the main power grid, especially when asked by the utility company. A major part of this work …

A Value Sensitive Design Approach To Reimagining Parental Control Apps, Prakriti Dumaru

All Graduate Theses and Dissertations, Fall 2023 to Present

Parental control apps are often used by families to regulate children's device usage and keep them safe online. However, existing tools focus on monitoring and restricting children, which can lead to tension and mistrust within families. This research takes a new approach by exploring how parental control apps can be redesigned to support positive family values, like encouraging open communication between parents and children and helping children self-regulate their behaviors. Through four in-depth studies, this dissertation looks at how these values play out in different real-life situations. It includes families with children on the autism spectrum, divorced households where parents …

Cognitive Behavioral Therapy Complemented With Emotion Regulation Training For Patients With Somatic Symptom Disorder: 3-Year Follow-Up To A Randomized Controlled Trial, John Barr

All Graduate Theses and Dissertations, Fall 2023 to Present

This manuscript is a 3-year follow-up analysis of a multicenter, randomized, parallel group, controlled trial (N = 254) employed with individuals struggling with somatic symptom disorder (SSD; Kleinstäuber et al., 2019) comparing the effects of cognitive behavioral therapy (CBT) alone and enriching cognitive behavioral therapy with emotion regulation training (ENCERT). Results from Kleinstäuber et al. (2019) suggested that both of these interventions were similarly efficacious for SSD for symptom severity (primary outcome), with moderate to large effects at post treatment and 6-month follow-up. Further analysis of secondary outcomes and moderation effects demonstrated results suggesting ENCERT was superior to CBT-SOMA …

The Socioecology Of Indigenous Archaeological Maize In The Uinta Basin, Utah, Sara Saouma

All Graduate Theses and Dissertations, Fall 2023 to Present

This thesis investigates the phenotypic variability of maize (Zea mays spp.) from archaeological sites located in the Uinta Basin, Utah. Maize was first introduced to the American Southwest around 5,000 years ago following its migration via trade routes from its native region of southern Mexico (Vint 2017). The adaptation of maize to the arid and temperate conditions of the American Southwest and Mexico triggered significant phenotypic change resulting from human and environmental selection pressures. This thesis focuses on the analysis of uncharred maize cobs from seven archaeological sites in the Uinta Basin. The analysis includes 70 corn cobs—most …

An Exploratory Study Of The Vertical Snarc Effect In Mayan Numerals: Effects Of Language Transparency And Reading Direction, Emmett A. Speed

All Graduate Theses and Dissertations, Fall 2023 to Present

The Mayan numerical system, used by the ancient Maya people, is very different from the Western Arabic numerical system. Instead of being based on 10, it's based on 20, and it uses dots and bars instead of the numbers 0 through 9. This study explored how people learn and understand Mayan numbers.

Participants took a 2.5-hour online course to learn Mayan numerals and number words. They were tested to see how quickly and accurately they could recognize and compare Mayan numerals. The results showed that people can learn the Mayan number system and use it automatically.

The study also looked …

Mathematical Modeling Of Effects Of Tumor Location On Lung Function., Lamargaret Temukisa Johnson

Master of Engineering Theses

Lung cancer has the highest rates of incidence and mortality of all cancers. Most lung cancer tumors are Non-Small Cell Lung Cancer (NSCLC). NSCLC patients with lesions in the upper lobes are found to have better prognosis compared to those with lesions in the middle and lower lobes. Previous studies have suggested various causes for this discrepancy at both the organ-scale and tissue-scale. To model NSCLC growth in different locations within the lung, an organ scale lung model and tissue scale tumor model were coupled through the tissue pressure, and oxygen and carbon dioxide partial pressures. The coupling was used …

Feasibility Study On Using Blue Clay As A Supplementary Cementitious Material (Scm)., Clark Lemon

Master of Engineering Theses

An effective strategy for reducing CO₂ emissions in the global cement industry is replacing a percentage of cement with supplementary cementitious materials (SCMs). As the availability of conventional SCMs such as fly ash and slag is decreasing, alternative SCMs such as calcined clays have been studied for their use as effective pozzolans. The present work investigates the feasibility of using a waste product from the quarrying industry known as blue clay as a viable SCM. It is composed of multiple clay minerals, predominantly muscovite. Raw and calcined at four temperatures (500, 650, 800, and 950°C), blue clay was analyzed …

Low-Level Memory Attacks On Edge Assisted Robotic Applications, William Arnold

Master of Engineering Theses

This thesis investigates how low-level memory faults can undermine edge-assisted robotic systems that rely on memory optimization. As robots are utilized in real world applications, the ability to operate safely and successfully in mission critical deployment becomes important. To help achieve these goals, developers are increasingly starting to place computation nodes at network edges to meet latency and reliability requirements. Edge nodes, however, are resource-constrained and resources conservation techniques such as Kernel Same-page Merging (KSM) are enabled to deduplicate identical pages across processes or virtual machines. This thesis shows that this optimization technique quietly widens the attack surface and can …

A Novel Diastolic Doppler Index Less Affected By Aortic Arch Anomalies Co-Existing With Coarctation, Arash Ghorbannia, Andrew D. Spearman, Shahd Sawalhi, Ronald K. Woods, Mehdi Maadooliat, John F. Ladisa Jr.

Mathematical and Statistical Science Faculty Research and Publications

Severity assessment for coarctation of the aorta (CoA) is challenging due to concomitant morphological anomalies (complex CoA) and inaccurate Doppler-based indices. Promising diagnostic performance has been reported for the continuous flow pressure gradient (CFPG), but it has not been studied in complex CoA. Our objective was to characterize the effect of complex CoA and associated hemodynamics on CFPG in a clinical cohort. Retrospective analysis identified discrete juxtaductal (n = 25) and complex CoA (n = 43; transverse arch and/or isthmus hypoplasia) patients with arm-leg systolic blood pressure gradients (BPG) within 24 h of echocardiography for comparison to BPG …

Trust In Healthcare Ai Can’T Just Be Designed – It Must Be Felt By Clinicians And Patients, Adriana Banozic-Tang, Heng Wang

Research Collection Yong Pung How School Of Law

Trust in healthcare AI currently over-relies on system design, not lived medical realities.Continuous feedback loops are necessary to embed trust in healthcare AI that is responsive to clinician and patient needs.Initiatives in South-East Asia show how trust in technology can be extended from policy to practice.

Ai In The Judiciary: The Singapore Case, Nydia Remolina Leon

Research Collection Yong Pung How School Of Law

This paper examines the integration of Artificial Intelligence (AI) within the judicial system of Singapore. Singapore's judiciary has embraced AI not as a tool for adjudication, but as an augmentative instrument for legal research, procedural efficiency, and access to justice. It provides a detailed account of AI use cases in the courts, including case summarization, evidence review, assistance for selfrepresented litigants, and tools like the Divorce Assets Informative Division Estimator. The discussion then turns to the legal profession, exploring how law firms in Singapore are adopting AI technologies. The paper also addresses how AI implementation in the judicial system is …