Digital Commons Network^™

Occupancy Of Fish Species Of Greatest Conservation Need And Temporal Patterns Of Assemblage Occurrence In Sandhills Ecoregion, Nebraska Streams, Braxton M. Newkirk

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

Fish species’ occurrence is influenced by environmental conditions across multiple spatial and temporal scales. Alteration to stream systems has the potential to affect occurrence patterns of fish species. Stream systems of the North American Great Plains face threats originating from climate change and anthropogenic activities resulting in negative implications for many fish species. The Sandhills Ecoregion, Nebraska is considered one of the largest intact grasslands in North America, and thus may experience fewer threats than surrounding areas. Stream systems of the Sandhills Ecoregion are home to 12 fish species of greatest conservation need (SGCN). Little context exists regarding the environmental …

Spatial Ecology Of American Bison On Vermejo Park Ranch, New Mexico, Kate Ann Asmus

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

American bison (Bison bison) are a keystone species that impact grassland productivity, plant diversity, and landscape heterogeneity. We used GPS telemetry and a replicate herbivore grazing experiment on Vermejo Park Ranch in northeastern New Mexico to advance understanding of bison spatial ecology and grazing dynamics. First, we evaluated the potentially disparate influences of forage productivity and site fidelity on the size and selection of home ranges of bison. Home range size was strongly negatively influenced by forage productivity. However, home range selection was influenced more strongly by site fidelity than spatial variation in forage, as bison selected home …

Vale Strategic Audit, Nikolas Mancio

Honors Program: Senior Projects (Public)

The Chinese government is critical in shaping the global mining and metals industry, specifically for companies like Vale S.A., the world’s largest iron ore and nickel producer. China’s dominance as the largest importer of iron ore significantly impacts commodity prices and demand, with its government exerting substantial influence through production quotas, infrastructure spending, and environmental regulations. Vale’s strategic position in the Chinese market is a cornerstone of its operations. It is supported by investments in distribution centers, blending facilities, and high-grade iron ore that align with China’s environmental goals. However, this reliance also makes Vale vulnerable to shifts in Chinese …

Exploring The Physiological, Biochemical, And Enzymatic Responses Of Vigna Mungo Varieties To Mungbean Yellow Mosaic India Virus (Mymiv) Infection, Subham Dutta, Poly Saha, Mritunjoy Barman, R. Poorvasandhya, Moumita Panda, Tarique Ahmed, Thomas Wilbur Davis, Bulbul Ahmed, Mudagadde G. Deeksha, Jayanta Tarafdar

Department of Entomology: Faculty Publications

This study aims to enhance sustainable disease management in black gram by identifying varieties resistant to Mungbean Yellow Mosaic India Virus (MYMIV). We screened sixteen black gram genotypes, assessing physiological, biochemical and enzymatic basis. Results revealed a range of resistance levels, with PANT URD-19 showing the highest resistance (PDI 0.47%) and Pejua the lowest (PDI 37.24%). Seven genotypes demonstrated strong resistance, highlighting the necessity for targeted breeding. Variations in leaf thickness, trichome density, stomatal frequency, and epicuticular wax content were significant, with resistant varieties like LBG-888 and PANT URD-19 exhibiting thicker leaves, higher trichome density, and more wax, correlating with …

Growing Industry-University Partnerships: Virtual Workshop On Industry Sponsored Research, Mark Stone, Santosh K. Pitla

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

The Department of Biological Systems Engineering (BSE) at the University of Nebraska-Lincoln (UNL) hosted a virtual workshop on developing capacity for industry-sponsored research (ISR). This dynamic event brought together faculty, researchers, industry leaders, and students to explore innovative strategies for advancing ISR.

The workshop addressed four key themes: (1) fostering sustainable industry-academic partnerships; (2) tackling intellectual property (IP) challenges; (3) building institutional and individual capacity for ISR, and (4) empowering students as critical contributors to industry research. Through expert-led presentations, an engaging panel discussion, and interactive brainstorming sessions, participants identified actionable steps and articulated a vision for the future of …

Gamma Sigma Delta, Nebraska Chapter Newsletter, Issue #66 December 2024

Gamma Sigma Delta, Nebraska Chapter: Newsletters

Nominations Solicitations Issue

President's Message, John R. Ruberson

Members

Grad Student Award

Teaching Award

Research Award

Extension Award

Award of Merit

Annual Membership Info

Student Award Fund

In Memoriam: John L. Lambert (April 25, 1942-July 3, 2024), Larry Elmer Germer (April 24, 1941-October 25, 2024), Leo Lucas (1931-November 13, 2024)

Pledge

United States Environmental Protection Agency Response To The Ofiice Of Science And Technology Policy Memo, 2022: Public Access Plan (December 2024)

Copyright, Fair Use, Scholarly Communication, etc.

EPA response to OSTP memo, 2022: Public Access Plan (December 2024)

United States Fish And Wildlife Service Response To The Office Of Science And Technology Policy Memo, 2022: Public Access Plan (December 2024)

Copyright, Fair Use, Scholarly Communication, etc.

FWS response to OSTP memo, 2022: Public Access Plan (December 2024)

United States Department Of Defense Response To The Office Of Science And Technology Policy Memo, 2022: Public Access Plan (December 2024)

Copyright, Fair Use, Scholarly Communication, etc.

DOD response to OSTP memo, 2022: Public Access Plan (December 2024)

Acf Response To Ostp Memo, 2022: Public Access Plan (December 2024)

Copyright, Fair Use, Scholarly Communication, etc.

ACF response to OSTP memo, 2022: Public Access Plan (December 2024)

Using High-Pressure Processing To Improve The Quality Of Dark-Cutting Beef, Ashley A. Hahn

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

Previous studies have shown high-pressure processing (HPP) can be utilized to improve lean color of dark-cutting beef color by increasing the lightness and redness of steaks. However, the optimal parameters of length of time product is held under pressure and at which pressure must be applied have yet to be fully defined. Furthermore, the impact of HPP on color labile muscles in dark-cutting beef are currently unknown. Therefore, two studies were designed and specific efforts were focused on first defining optimal parameters for color stable muscles, followed by determining the effect of HPP on dark-cutting color labile muscles.

In the …

Relationship Between Host Genomics And Microbiomics In Beef Cattle, Andrew D. Lakamp

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

As sequencing technology becomes more affordable and throughput increases, microbiome information is becoming more readily available. For beef cattle selection, microbial information has a variety of uses including being a target for genetic prediction or used as a means to explicitly describe additional phenotypic variability in other traits.

Infectious bovine keratoconjunctivitis (IBK), commonly known as pinkeye, is a disease that infects the ocular surface and surrounding tissue which is an animal health and producer economic concern. Vaccinations have shown to have variable effectiveness, while limited genetics studies have suggested that direct genetic selection for resistance would be slow. Therefore, an …

Examining Factors Of Variance In Energy Metabolism Of Dairy Cattle, Addison L. Carroll

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

Variation is thought to occur in the use of dietary energy for production in dairy cattle. First, variance can be observed when new methane mitigation strategies are fed resulting in increased H₂ output potentially resulting in downstream effects on estimates of heat production via the Brouwer (1965) equation. Therefore, in chapter 3 a review was created to systematically describe the mathematics and theory behind the Brouwer equation, and rederive a heat production equation to integrate H₂ production. Results indicate heat production using the classical Brouwer equation (1965) relative to the rederived equation resulted in an overestimation of heat …

Impacts Of Annual Forage Management On Grazing Cattle Performance And Carrying Capacity, Shelby Davies Jenkins

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

Rapid conversion of historical grasslands to cropland in recent history has led to limited perennial pasture availability and an increase in cost of pasture rent. Annual forages are an alternative grazing source. Many annual forages can grow and accumulate stockpile following summer harvest of wheat. Strip grazing is often suggested to increase grazing efficiency of stockpiled forages. To evaluate this, a stockpiled mixture of annual forages were either strip grazed or grazed continuously in the fall and winter. The mixture contained oats and rapeseed in the first year and a diverse warm season annual mixture in the second. Strip grazing …

Virtual Control: A Comparison Of Methods For Hand-Tracking Implementation, Nathan Roberts

Honors Program: Senior Projects (Public)

This thesis examines the design philosophy of modern virtual reality applications that utilize hand-tracking as a primary form of user input. The analysis presented hopes to provide ideas for future implementations of this technology so that more immersive experiences are developed. This analysis starts with the discussion of a modern example of successful hand-tracking implementation, then comparing that implementation to a recent senior design project. This comparison is primarily based on each experience’s ability to create interactivity and immediacy. Interactivity is the degree to which the user can quickly and reliably make changes to their virtual environment, while immediacy is …

Nebraska Department Of Transportation Strategic Audit, Chloe Hoover

Honors Program: Senior Projects (Public)

The Nebraska Department of Transportation (NDOT) is a state government agency that is responsible for the planning, development, design, construction, maintenance, and administration of the state highway system. Two strategic analyses are completed about NDOT: a PESTEL analysis and Porter’s Five Forces analysis. Both of these analyses showed that since NDOT is a state agency, it impacts foundational aspects of its strategy. NDOT’s strategy is influenced by its financial strategy, policies or political influence, and public importance. NDOT competes with other companies in its workforce and employees and/or applicants leaving NDOT for other companies. This report details NDOT’s strategy, competitive …

Development And Characterization Of Organic Electrocatalysts For Use In Zinc-Air Batteries, Christopher John Merkel

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

The global deployment of solar photovoltaic and wind power is projected by the International Energy Agency as the primary pathway to reduce dependence on fossil fuels. However, these technologies face a critical bottleneck: their inherently intermittent power generation. For “intermittent renewables” to become the dominant source of electrical energy, efficient energy storage systems are essential. Current storage solutions are not viable on a global scale due to material scarcity, safety concerns, and high capital costs. Among emerging technologies, zinc-air batteries (ZABs) have garnered significant interest. ZABs offer a theoretical energy density five times greater than traditional lithium-ion batteries, utilize safe …

Impacts Of Stream Bed Adjustment On Local Bridge Morphology At Highway 281, Molly G. Likins

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Nebraska sand-bed rivers have long been a part of sediment transport studies and have been used in the development of numerous well-known empirical bedload equations. Some of these studies have shown how adjustments in streambed elevation led to changes in local stream morphology. The sand-bed rivers of Nebraska are highly susceptible to such changes due to their wide, shallow cross-sections and erodibility. The objective of our study is to synthesize a hydrodynamic model with high-resolution field data and improved methods of representing sediment transport to better predict both short and long-term channel adjustments for an aggraded sand-bed river.

The field …

Numerical Study On The Behavior Of Natural And Recycled Aggregate Concretes, Shahriar Mardpour

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

This thesis investigates the mechanical behavior of natural and recycled aggregate concretes (NAC and RAC) using a multi-phase numerical approach to predict performance. Growing interest in sustainable materials has led to using recycled concrete aggregates (RCA) to replace natural aggregates, creating Recycled Aggregate Concrete (RAC). Due to their different structural components, RAC and NAC exhibit varying mechanical properties, particularly in strength and durability.

This study validated tension and bending (flexural) test models by comparing numerical results with similar models from the literature. Following validation, a multi-phase approach modeled NAC and RAC for the bending (flexural) and tension tests, providing a …

Development And Evaluation Of Highly Thixotropic Uhpc Mixtures For Bridge Overlay Applications, Akbota Aitbayeva

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Ultra-high-performance concrete (UHPC) is an advanced construction material renowned for its exceptional strength and durability. However, conventional UHPC is typically self-consolidating, making it unsuitable for bridge deck overlay applications due to challenges posed by potential surface slopes. UHPC overlay construction requires a highly thixotropic material that not only responds well to vibration but also maintains workability over an extended period and remains stable on sloped surfaces. Despite the complex rheological properties of highly thixotropic UHPC, limited testing methods are available to effectively assess the workability and rheology of overlay mixtures. To address this gap, the present study provides a comprehensive …

Exploring Variably Saturated Flow Formulations For Modflow: Implementing A Fully 3d Richards' Equation In Modflow 6, Sebastian Vazquez-Gasty

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

This thesis explores the implementation of a fully 3D Richards’ equation solution into MODFLOW 6 to solve for saturated/unsaturated flow. Currently, MODFLOW 6 has limited capability for solving unsaturated zone flow problems by using the Unsaturated Zone Flow (UZF) package, which neglects capillarity and assumes vertical 1-dimensional flow. Various formulations of the Richards’ equation were first evaluated for their strengths and weaknesses. Various numerical solution approaches to Richards’ equation were also studied to understand the robustness and efficiency of different approaches and to select one that would best fit into the MODFLOW 6 framework. The MODFLOW 6 framework was also …

Improving Thermionic Power Generation Via The Reduction Of Emission Barriers, Chace E. Franey

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

This thesis investigates methods to improve the performance of thermionic energy converters (TECs) by reducing the emission barriers. A TEC generates electricity from thermal energy when electrons are emitted from a hot electrode (the emitter) through a vacuum gap and absorbed by a cooler electrode (the collector). Due to their lack of working fluids and inherently compact nature, TECs have garnered attention over the years for their potential as a means of power generation in space or high-grade waste heat recovery. Historically, however, the practical implementation of TECs has been hindered by significant technical challenges. Recent advancements in microfabrication techniques …

Electrochemical Treatment Of Mining And Oilfield Wastewater Using Recycled Titanium Alloy Electrodes, Sean Michael Thompsen

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

This thesis explores the integration of circular economy principles into wastewater treatment through the innovative use of recycled Ti-6Al-4V titanium alloy electrodes. By repurposing titanium alloys from metal additive manufacturing (AM) waste, the research aims to address the treatment of acidic and oil-contaminated industrial wastewater in a sustainable manner. The recycled electrodes demonstrate notable stability and fouling resistance in challenging acidic conditions, attributed to their unique surface porosity and conductive properties. Electrochemical processes, including hydrogen evolution at the cathode, facilitate metal ion precipitation and destabilize surfactant-stabilized oil droplets. Cyclic voltammetry and long-term stability tests highlight the electrodes’ resilience, providing an …

Development Of A Surface-Mounted Strong Post For The Midwest Guardrail System, Gnyarienn Selva Kumar

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

This research investigated the development of a surface-mounted strong post for the Midwest Guardrail System (MGS), designed to replicate the behavior of the standard MGS post, a W6 x8.5, 72-in. long post embedded 40 in. into strong soil. The MGS is a strong post, W-beam guardrail system that has been successfully evaluated in many applications using crashworthiness criteria described in the American Association of State Highway and Transportation Officials (AASHTO) Manual for Assessing Safety Hardware (MASH). However, in some locations, conventional soil-embedded posts are impossible to install due to subgrade obstructions like concrete slabs, mow strips, utilities, and limited right-of-way. …

Predictors Of Belongingness In First-Year College Students: Examining Mental Health And Adjustment, Jordan D. Foreman-Black

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

The initial transition to college is a pivotal moment for emerging adults, often influencing whether a student will remain successful. Students face a significant challenge adapting to the new environment that has been compounded by their experiences through the COVID-19 pandemic. Despite these challenges, a sense of belonging for students has been shown to be a key aspect of a successful transition to college. Students are often confronted with increasing levels of mental health challenges throughout the transition, specifically experiencing increasing mental health difficulties or challenges throughout their initial adjustment to college. Moreover, parents have become increasingly involved in students’ …

Argument Schema Of Undergraduate Engineering Students, Anu Singh

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

Critical thinking is one of the most desired skills in the workplace, as it assists an individual in solving complex problems and making informed decisions, resulting in their workplace success. Argumentation is one instructional approach that provides students an opportunity to engage in higher-order thinking and improve their communication skills. Argumentative writing provides opportunities to engage in multiple perspectives of a problem, provide evidence for the claim, evaluate evidence, engage in reasoning, and acknowledge self-bias, which automatically engages students in critical thinking. Previous literature has shown that despite the use of interventions and scaffolding approaches, students' argumentative texts lack elements …

Increasing The Impact Of Dietary Fiber From Grains On Human Health Through Gut Microbiome, Sujun Liu

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

The relationship between dietary fiber intake and human health has gained significant attention due to its potential in preventing chronic diseases and promoting gut health. Grains are a primary source of dietary fiber; however, the health impact of grain fibers is often limited because they are incompletely metabolized by gut bacteria. This dissertation explores innovative strategies to enhance the concentration and of dietary fiber from grains and its utilization by gut bacteria. By investigating various treatments, this research aims to maximize the health benefits of grain-derived dietary fibers, thereby contributing to a healthier society.

This dissertation is organized into four …

Help-Seeking For College Algebra Students' Success: A Phenomenological Mixed Methods Study, Colby Lamb

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

Because the failure rate for college algebra is large and sometimes up to 50%, college algebra serves as a gatekeeper to STEM fields and degree completion. Therefore, it is critical to examine students who are at risk of dropping, withdrawing, and failing college algebra help-seeking behavior. The purpose of this mixed methods study was to focus on students’ perceptions of in-classroom and out-of-classroom activities and systems in a college algebra course designed based on principles of active learning and how those activities and systems are affordances or barriers to help-seeking. The research questions to be addressed were:

Central Research Question: …

Three New Pieces For Double Bass By Colombian Composers Influenced By Colombian Traditions, Javier Alejandro Barreto Olaya

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

This document presents a study on the double bass as a solo instrument within traditional Colombian music, a tradition in which it has generally been relegated to accompaniment functions. I have commissioned three original works by Colombian composers, the integration of traditional genres, including sanjuanero, caña, danza, guabina, and llanero Airs, with modern compositional approaches. The commissioned pieces expand the solo repertoire of the double bass and highlight its potential and ability to adapt to traditional musical contexts. The lack of original repertoire for solo double bass in Colombian music is also addressed, integrating the commissioned pieces. The contribution of …

Dynamics Of Flexible Freestanding Structures Under Ground Motion Excitation, Seyed Mohammadreza Farooghi Mehr

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

Freestanding structures are characterized by being unattached at the base, exhibiting rigid or flexible motion under ground motion excitation with various potential responses including rocking (rotation at the base about corner points), pure sliding, slide-rocking, and overturning. While rigid freestanding structures have been extensively studied, the behavior of flexible freestanding structures—particularly the interaction between modes involving sliding—remains underexplored. Existing literature has focused on the deformation and rocking motions of flexible freestanding structures through both analytical and experimental approaches, which have shown indications of sliding at the base. These findings highlight the necessity of incorporating sliding motion into analytical models to …