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A Systems Biology Approach To Predict Phenotypes From Genotypes For Plants And Bacteria, Niaz Bahar Chowdhury Oct 2024

A Systems Biology Approach To Predict Phenotypes From Genotypes For Plants And Bacteria, Niaz Bahar Chowdhury

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

Predicting phenotypes from genotypes is a central challenge in systems biology in understanding how organisms respond to environmental and genetic changes. To address this, genome-scale metabolic models (GSMs) integrated with omics data and machine learning provide a comprehensive framework to connect genotype to phenotype. This dissertation utilizes these approaches in plants and bacterial systems, revealing key metabolic adaptations. In maize, a root-specific GSM reveals metabolic reprogramming under nitrogen stress, offering strategies for improving stress tolerance. Building on this, a multi-organ maize GSM of temperature stress identifies metabolic bottlenecks, providing targets to enhance crop resilience. Similarly, in rice, a grain-specific GSM …


Classifying Open Access Business Models, Tasha Mellins-Cohen Oct 2024

Classifying Open Access Business Models, Tasha Mellins-Cohen

Copyright, Fair Use, Scholarly Communication, etc.

The proliferation of open access (OA) business models has been rapid, presenting challenges for stakeholders in communicating and working effectively with one another. This article aims to clarify terminologies and address the inconsistencies and gaps in previous attempts to categorize OA models, supporting informed decision-making. It presents five core types, each with distinct characteristics and implications for funding, equity, and implementation. Operating at the level of individual pieces of content, transactional models expose authors to the financial implications of their decisions to make content OA; they often must pay out of their own funds. Driven by negotiations between libraries or …


Voltage-Controlled Spintronics And Fundamentals Of Magnetoelectricity In Magnetoelectric Antiferromagnetic Chromia, Syed Qamar Abbas Shah Oct 2024

Voltage-Controlled Spintronics And Fundamentals Of Magnetoelectricity In Magnetoelectric Antiferromagnetic Chromia, Syed Qamar Abbas Shah

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

Spintronics, which exploits both the spin and charge of electrons, offers a path to more energy-efficient and functionally enhanced devices compared to traditional CMOS electronics. A significant development in this field is voltage-controlled spintronics, where electric fields manipulate magnetic and spin states without the large power dissipation seen in current-based technologies. Among the materials explored for this purpose, magnetoelectric (ME) antiferromagnetic (AFM) materials show promise for energy-efficient, non-volatile memory technologies. Controlling AFM ordering via voltage application is essential for realizing these devices.

This dissertation focuses on ME AFM materials, specifically chromia (Cr2O3), to advance voltage-controlled spintronics. …


Invasive Forest Pest Education Through Identification, Reporting, And Children’S Introduction Brochures, Lauren E. Keefe Oct 2024

Invasive Forest Pest Education Through Identification, Reporting, And Children’S Introduction Brochures, Lauren E. Keefe

Department of Entomology: Distance Master of Science Projects

Forest pest insects, whether native or non-native, can be extremely detrimental to the health of a landscape, and can contribute to massive ecological, economic, and cultural losses. Unless directly exposed to the damage these pests cause, many people do not seek to become informed on the insects. A series of brochures was thus created as a collaboration between the online UNL M.S. in Entomology requirements and a need for updated Nebraska Forest Service Forest Health brochures. These brochures focus on invasive forest insect identification and reporting, as well as introducing the concepts of the invasives to children.

Five invasive insects …


A Teaching Resource Guidebook: Insect Edition, Autumn Greer Oct 2024

A Teaching Resource Guidebook: Insect Edition, Autumn Greer

Department of Entomology: Distance Master of Science Projects

Welcome to A Teaching Resource Guidebook: Insect Edition. This book was created with an aim to help educators develop lesson plans for children of all ages. This book contains a list of books and other activities for the developmental understanding of insects, as well as helpful information for you, the educator. This section of the book was designed to help you, the educator, understand the layout of this resource guide and provide you with an example of how to navigate this guidebook.


Intrinsic And Environmental Drivers Of Pairwise Cohesion In Wild Canis Social Groups, John F. Benson Sep 2024

Intrinsic And Environmental Drivers Of Pairwise Cohesion In Wild Canis Social Groups, John F. Benson

School of Natural Resources: Faculty Publications

Animals within social groups respond to costs and benefits of sociality by adjusting the proportion of time they spend in close proximity to other individuals in the group (cohesion). Variation in cohesion between individuals, in turn, shapes important group-level processes such as subgroup formation and fission–fusion dynamics. Although critical to animal sociality, a comprehensive understanding of the factors influencing cohesion remains a gap in our knowledge of cooperative behavior in animals. We tracked 574 individuals from six species within the genus Canis in 15 countries on four continents with GPS telemetry to estimate the time that pairs of individuals within …


Climate Smart Agriculture, J. David Aiken Sep 2024

Climate Smart Agriculture, J. David Aiken

Cornhusker Economics

There are several programs encouraging producers to reduce their carbon intensity, including United States Department of Agriculture climate-smart agriculture programs, the 2024 Nebraska Climate Action Plan, and the 2024 Nitrogen Reduction Incentive Act. The hope is that producers with lower carbon intensity (CI) scores will receive a premium for their products. Producers would be well advised to learn more about these programs, as reducing carbon intensity in agriculture seems to be an emerging agricultural policy trend that will be with us for some time to come.


Institutional Data Repositories Are Vital, Jen Darragh, Mikala R. Narlock, Halle Burns, Peter A. Cerda, Wind Cowles, Leslie M. Delserone, Seth Erickson, Joel Herndon, Heidi Imker, Lisa R. Johnston, Sherry Lake, Michael Lenard, Alicia Hofelich Mohr, Jennifer Moore, Jonathan Petters, Brandie Pullen, Shawna Taylor, Briana Wham Sep 2024

Institutional Data Repositories Are Vital, Jen Darragh, Mikala R. Narlock, Halle Burns, Peter A. Cerda, Wind Cowles, Leslie M. Delserone, Seth Erickson, Joel Herndon, Heidi Imker, Lisa R. Johnston, Sherry Lake, Michael Lenard, Alicia Hofelich Mohr, Jennifer Moore, Jonathan Petters, Brandie Pullen, Shawna Taylor, Briana Wham

University of Nebraska-Lincoln Libraries: Faculty Publications

As funding agencies and publishers reiterate research data sharing expectations (1), many higher-education institutions have demonstrated their commitment to the long-term stewardship of research data by connecting researchers to local infrastructure, with dedicated staffing, that eases the burden of data sharing. Institutional repositories are an example of this investment (2). They provide support for researchers in sharing data that might otherwise be lost: data without a disciplinary repository, data from projects with limited funding, or data that are too large to sustainably store elsewhere. The staffing and technical infrastructure provided by institutional repositories ensures responsible access to information while considering …


Appraising Groundwater Quality And Probabilistic Human Health Risks From Fluoride-Enriched Groundwater Using The Pollution Index Of Groundwater (Pig) And Gis: A Case Study Of Adama Town And Its Vicinities In The Central Main Ethiopian Rift Valley, Hassen Shube, Shankar Karuppannan, Muhammed Haji, Balamurugan Paneerselvam, Nafyad Kawo, Abraham Mechal, Ashu Fekadu Sep 2024

Appraising Groundwater Quality And Probabilistic Human Health Risks From Fluoride-Enriched Groundwater Using The Pollution Index Of Groundwater (Pig) And Gis: A Case Study Of Adama Town And Its Vicinities In The Central Main Ethiopian Rift Valley, Hassen Shube, Shankar Karuppannan, Muhammed Haji, Balamurugan Paneerselvam, Nafyad Kawo, Abraham Mechal, Ashu Fekadu

School of Natural Resources: Faculty Publications

This research's main objective is to identify the level of contamination in drinking water in Adama town and its environs by employing PIG, GIS and HHRA. The physical–chemical parameters of groundwater were determined, and the results were compared to regional and global drinking water quality guidelines. The pH of groundwater is alkaline, and the contents of Ca2+, Na+, HCO3 −, and F− in the majority of samples surpassed the permissible drinking limit. The hydrochemical facies were identified in the following order: Ca–Mg–HCO3, Na–Ca–HCO3, and Na–HCO3. Cation …


Gamma Sigma Delta, Nebraska Chapter Newsletter, Issue #65 September 2024 Sep 2024

Gamma Sigma Delta, Nebraska Chapter Newsletter, Issue #65 September 2024

Gamma Sigma Delta, Nebraska Chapter: Newsletters

Chapter Officers and Committees for 2024

2023 Chapter Awards Recipients: Undergraduate Awards, Graduate, Teaching and Research Awards

Lack of Award nominations and New Initiates

Membership information and Dues form

Chapter Student Award Fund Info

In Memoriam: Lyle E. Davis (January 27, 1927-January 23, 2023); David John Andrews (June 28, 1933-February 15, 2024); Richard A. Wiese (April 3, 1928-February 22, 2024); William T. “Bill” Ahlschwede (January 31, 1942-February 27, 2024); Theodore (Ted) Eugene Hartung (January 26, 1929-June 5, 2024); John Edward Foster (May 22, 1940-October 1, 2024)


Unl Emeriti And Retirees Association Newsletter, September 2024 Sep 2024

Unl Emeriti And Retirees Association Newsletter, September 2024

UNL Emeriti and Retirees Association: Newsletters and Other Materials

University of Nebraska-Lincoln Emeriti and Retirees Association Newsletter, September 2024


Dirt/Μ: Automated Extraction Of Root Hair Traits Using Combinatorial Optimization, Peter Pietrzyk, Neen Phan-Udom, Chartinun Chutoe, Lise Pingault, Ankita Roy, Marc Libault, Patompong Johns Saengwilai, Alexander Bucksch Sep 2024

Dirt/Μ: Automated Extraction Of Root Hair Traits Using Combinatorial Optimization, Peter Pietrzyk, Neen Phan-Udom, Chartinun Chutoe, Lise Pingault, Ankita Roy, Marc Libault, Patompong Johns Saengwilai, Alexander Bucksch

Department of Entomology: Faculty Publications

As with phenotyping of any microscopic appendages, such as cilia or antennae, phenotyping of root hairs has been a challenge due to their complex intersecting arrangements in two-dimensional images and the technical limitations of automated measurements. Digital Imaging of Root Traits at Microscale (DIRT/μ) is a newly developed algorithm that addresses this issue by computationally resolving intersections and extracting individual root hairs from two-dimensional microscopy images. This solution enables automatic and precise trait measurements of individual root hairs. DIRT/μ rigorously defines a set of rules to resolve intersecting root hairs and minimizes a newly designed cost function to combinatorically identify …


Willingness To Pay And Market Potential For Biowrap: An Economic Study Of A New Biodegradable Mulch Product In Home Gardening, Gengchen Cai Sep 2024

Willingness To Pay And Market Potential For Biowrap: An Economic Study Of A New Biodegradable Mulch Product In Home Gardening, Gengchen Cai

Department of Agricultural Economics: Dissertations, Theses, and Student Research

This study explores the market potential of BioWRAP, a biodegradable sprayable weed suppression product, by assessing the willingness to pay (WTP) among American home gardeners. Traditional plastic mulch offers significant agronomic benefits but poses considerable environmental challenges, making BioWRAP a promising alternative due to its similar benefits and reduced environmental impact. Using a double-bounded contingent valuation method, we analyze the WTP for BioWRAP among different demographic groups and gardening practices. Our findings indicate that the highest WTP for BioWRAP is among home gardeners who currently use chemical sprays for weed suppression, followed by those using physical barriers, with the lowest …


Imaging Photoinduced Dynamics In Gas-Phase Molecules Using Ultrafast Electron And X-Ray Diffraction, Sri Bhavya Muvva Sep 2024

Imaging Photoinduced Dynamics In Gas-Phase Molecules Using Ultrafast Electron And X-Ray Diffraction, Sri Bhavya Muvva

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

Investigating the ultrafast structural changes in photoexcited molecules provides essential information on their governing reaction mechanisms and product formation. Time-resolved electron and X-ray diffraction are crucial techniques for capturing the structural information of photoexcited molecules on femtosecond timescales. This thesis presents the investigations of photochemical reactions in gas-phase molecules using ultrafast electron and X-ray diffraction experiments.

Photoexcitation of conjugated diene molecules with ultraviolet (UV) laser pulses can lead to different reaction mechanisms, depending on their double bonds’ positions and molecular rigidity. Chapter 2 of this dissertation discusses the femtosecond time-resolved UV-induced excited-state structural dynamics of cis,cis-1,3-cyclooctadiene, an eight-membered cyclic conjugated …


How Much Green To Keep The Garden Clean? An Analysis Of The Willingness To Pay (Wtp) Of Home Gardeners For Biowrap Technology, Gengchen Cai, Kanij Fatema, Karina A. Schoengold Aug 2024

How Much Green To Keep The Garden Clean? An Analysis Of The Willingness To Pay (Wtp) Of Home Gardeners For Biowrap Technology, Gengchen Cai, Kanij Fatema, Karina A. Schoengold

Cornhusker Economics

A research team from the University of Nebraska-Lincoln, Kansas State University, and South Dakota School of Mines are working on creating an alternative product that would use locally available materials to create a spray-on, biodegradable polymer that can suppress weeds and will biodegrade in a timeframe that is amenable to crop production. We broadly refer to this technology as BioWRAP (Bioplastics with Regenerative Agricultural Properties).

Our results show that the home garden market is potentially a significant one for a BioWRAP product. Continued work in the development of the BioWRAP technology is necessary to determine what the cost of a …


Ponca State Park Vascular Plant Species List, Robert F. Steinauer Aug 2024

Ponca State Park Vascular Plant Species List, Robert F. Steinauer

Nebraska Game and Parks Commission: White Papers, Conference Presentations, and Manuscripts

A list of vascular plant species found in Ponca State Park. Arranged by plant family and then species name. Also included are descriptions of locations where the species is commonly found.


Wildcat Hills Rare Plant Survey Final Report, Steven B. Rolfsmeier Aug 2024

Wildcat Hills Rare Plant Survey Final Report, Steven B. Rolfsmeier

Nebraska Game and Parks Commission: White Papers, Conference Presentations, and Manuscripts

This survey report summarizes fifteen days of field work in eleven sites scattered across the Wildcat Ridge that were completed between May and August of 1996. Forty-five occurrences of 15 plant species on the Nebraska Natural Heritage element list were found. Ten tracts of high quality (or otherwise noteworthy) native communities were identified. Included in the report are site descriptions and element occurrences.


Groundwater Modeling Of The Ogallala Aquifer: Use Of Machine Learning For Model Parameterization And Sustainability Assessment, Tewodros Aboret Tilahun Aug 2024

Groundwater Modeling Of The Ogallala Aquifer: Use Of Machine Learning For Model Parameterization And Sustainability Assessment, Tewodros Aboret Tilahun

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

Addressing groundwater depletion problems in heterogeneous aquifer systems is a challenge. The heterogeneous Ogallala Aquifer, a critical source of groundwater in the central United States, has undergone decades of decline in water levels due to pumping. This project aims to build a robust groundwater model to evaluate optimal scenarios for sustainable use of the groundwater resource within a section of the Ogallala aquifer located in the Middle Republican Natural Resources District (MRNRD). This study follows a comprehensive approach involving parameterization, construction, and optimization. The model is parametrized using hydraulic conductivity and recharge values obtained from a random forest-based machine learning …


The Feasibility Of Utilizing The Open Dynamic Interaction Network (Odin) App To Assess Rema Data Across 30 Days Among Those Recovering From Alcoholism, Dennis E. Mcchargue, Bilal Khan, Jesscia Phelps, Patrick Duryea, Kimberly A. Tyler, Arthur Andrews, Ellie Reznicek, Lucy Napper, Mohamed Saad, Hsuan-Wee Lee Aug 2024

The Feasibility Of Utilizing The Open Dynamic Interaction Network (Odin) App To Assess Rema Data Across 30 Days Among Those Recovering From Alcoholism, Dennis E. Mcchargue, Bilal Khan, Jesscia Phelps, Patrick Duryea, Kimberly A. Tyler, Arthur Andrews, Ellie Reznicek, Lucy Napper, Mohamed Saad, Hsuan-Wee Lee

Department of Psychology: Faculty Publications

About ~4 million people with an alcohol use disorder receive treatment annually, and frequent relapse has produced a rapid revolving door between recovery and use. This paper presents preliminary data from a prospective micro-longitudinal study (30 days) that examines co-evolution of relapse risk processes of people with alcohol use disorders who entered a short-term residential substance use treatment. The primary goal of the current data was to assess the feasibility of using the open dynamic interaction network (ODIN) responsive ecological momentary assessment (rEMA). rEMA collected daily estimates on affect, urges, sober-support engagement, and use. The ODIN app administered twelve questions …


Development Of A Multidimensional Measure Of Wellbeing For Emerging Adults Utilizing A Convergent Parallel Mixed Method Design, Kelley Marie Wick Aug 2024

Development Of A Multidimensional Measure Of Wellbeing For Emerging Adults Utilizing A Convergent Parallel Mixed Method Design, Kelley Marie Wick

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

Attempting to conceptualize wellbeing is difficult, and the current research literature does not offer a standard definition that encapsulates the complexity of this construct, nor has there been a thorough consideration the impact of culture and societal standards of behavior on wellbeing. Additionally, the emergence of a new developmental period between adolescence and true adulthood (emerging adulthood) offers an additional layer of nuance, as many of the traditional scales currently used to measure wellbeing are inappropriate for emerging adults. A major gap in the current research literature is the reluctance in developing measures with the help of the target population. …


Conservation Decision Making And Agricultural Land Leasing - An Experimental Investigation Of The Role Of Gender, Diya Ganguly, Simanti Banerjee, Christopher Gustafson Aug 2024

Conservation Decision Making And Agricultural Land Leasing - An Experimental Investigation Of The Role Of Gender, Diya Ganguly, Simanti Banerjee, Christopher Gustafson

Cornhusker Economics

This research investigated the impact of landowner gender and of the different types of contract leases offered by them to a male tenant, on the conservation (or non-conservation) choice made by the tenant. Specifically, we investigate if a) female and male landowners offer different rental contracts and b) whether tenants choose different actions based on the landowner’s gender. For this purpose, we implemented a controlled, gender-context-loaded economic experiment with university students, in which we tested contract and land use choice under different treatments for three types of rental contracts – fixed rent, fixed rent with penalty, and fixed rent with …


Fourier Transform Ion Cyclotron Resonance Mass Spectrometry Applications For Metabolomics, Darcy Cochran, Robert Powers Aug 2024

Fourier Transform Ion Cyclotron Resonance Mass Spectrometry Applications For Metabolomics, Darcy Cochran, Robert Powers

Robert Powers Publications

Metabolomics is an interdisciplinary field that aims to study all metabolites < 1500 Da that are ubiquitously found within all organisms. Metabolomics is experiencing exponential growth and commonly relies on high-resolution mass spectrometry (HRMS). Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) is a form of HRMS that is particularly well suited for metabolomics research due to its exceptionally high resolution (105–106) and sensitivity with a mass accuracy in parts per billion (ppb). In this regard, FT-ICR-MS can provide valuable insights into the metabolomics analysis of complex biological systems due to unique capabilities such as the easy separation of isobaric and isomeric species, isotopic fine structure analysis, spatial resolution of metabolites in cells and tissues, and a high confidence (error) in metabolite identification. Alternatively, the large and complex data sets, long acquisition times, high cost, and limited access mainly through national mass spectrometry facilities may impede the …


A Measurement Of The Differential Drell-Yan Cross Section As A Function Of Invariant Mass In Proton–Proton Collisions At √ S = 13 Tev, William Robert Tabb Aug 2024

A Measurement Of The Differential Drell-Yan Cross Section As A Function Of Invariant Mass In Proton–Proton Collisions At √ S = 13 Tev, William Robert Tabb

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

The Drell-Yan process, a crucial mechanism for producing lepton pairs in highenergy hadron collisions, serves as an essential probe for testing the Standard Model of particle physics. This dissertation presents a comprehensive measurement of the differential cross section with respect to the invariant mass of the lepton pairs, utilizing data collected by the CMS experiment at CERN from 2016 to 2018. Cross sections are essential for refining our understanding of parton distribution functions and the underlying quantum chromodynamics processes, thereby providing constraints on theoretical predictions. In this analysis, the cross sections are compared to theoretical models and simulations, offering new …


Psychosocial Well-Being Facilitation Of Leader Identity Transitions For Retirees, Brooke Wells Aug 2024

Psychosocial Well-Being Facilitation Of Leader Identity Transitions For Retirees, Brooke Wells

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

Leadership scholars have worked to advance the knowledge of leader identity—how one views oneself as a leader—across many age groups. However, there is still little known about leader identity in older adults. This study explored how older adults identified as leaders after exiting the workforce and in retirement. The retirement process often indicates a transition in which one plans to navigate life post-workforce. For some, retirement may be a signal of growing older. Social identity theory scholars argue that retirees do not always embrace this aging identity. Individuals’ thoughts regarding aging are complex. For those able to embrace and navigate …


Nebline, August/September 2024 Aug 2024

Nebline, August/September 2024

NEBLINE Newsletter Archive from Nebraska Extension in Lancaster County

Preserving the Harvest: Canning, Freezing and Drying Tips, Kayla Colgrove

How Savvy are YOU with Home Canning?

Recipe of the Month: Freezing Onions, Kayla Colgrove

Deep, Infrequent Irrigation Makes Lawns and Trees Healthier, Sarah Browning

Garden Guide: Things to Do This Month, Mary Jane Frogge

Get the Jump on Jumping Worms, Kait Jumpman

Preparing Water for Use in an Emergency, Becky Schuerman

Heart of 4-H Volunteer Award: Nicole Miller and Cole Meador

4-H Teen Council Invites New Members

4-H Announcements

Lancaster County Super Fair, August 1-10, 2024

4-H Premiere Communication Event Top Results

4-H Clover College: 55 Hands-on Workshops

4-H …


Assessing Soil Properties & Suitability For Optimized Irrigation Development In Sudan, Northern Africa, Suhib O. Hamid Aug 2024

Assessing Soil Properties & Suitability For Optimized Irrigation Development In Sudan, Northern Africa, Suhib O. Hamid

Department of Agricultural and Biological Systems Engineering: Masters Project Reports

In Chapter 1, soil properties essential for efficient irrigation are thoroughly assessed. Factors such as soil texture, infiltration rates, and nutrient content are analyzed to provide insights into the selection of modern irrigation systems. Utilizing data collected from 3,192 locations through GPS and laboratory analyses, alongside sophisticated ranking systems, the research determines the most suitable irrigation methods for specific soil series. Findings highlight the remarkable efficiency of drip irrigation across various soil types, contrasting with the consistently lower performance of surface irrigation. The chapter emphasizes the significance of considering soil variability, evapotranspiration, and investment factors in selecting irrigation methods for …


Developing A Comprehensive Genome-Scale Metabolic Model For The Arabidopsis Thaliana Root System, Lohani Esterhuizen Aug 2024

Developing A Comprehensive Genome-Scale Metabolic Model For The Arabidopsis Thaliana Root System, Lohani Esterhuizen

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

Arabidopsis thaliana (Arabidopsis) is the most well-established model plant to date. Being the first plant to have its genome mapped, studies on Arabidopsis have provided insurmountable insights into the physiological and biochemical nature of plants. Methods that allow us to computationally study the metabolism of organisms include the use of genome-scale metabolic models (GEMs). Despite its popularity, no GEM currently maps the metabolic activity in the root system of Arabidopsis, which is the first organ to face and respond to stress conditions in the soil. This work aims to develop and implement a comprehensive GEM of the Arabidopsis root system …


Evaluation Of Unreinforced And Geosynthetic-Reinforced Subgrade Material Performance With Large-Scale Tracking Wheel Tests And Dynamic Cone Penetrometer Tests, Kenaz Owusu Aug 2024

Evaluation Of Unreinforced And Geosynthetic-Reinforced Subgrade Material Performance With Large-Scale Tracking Wheel Tests And Dynamic Cone Penetrometer Tests, Kenaz Owusu

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

Subgrade has a significant impact on the performance of a pavement as it serves as the foundation layer on which traffic loads are transferred. Many pavement failures can be attributed to weak subgrade strength. The integration of geosynthetics in road pavements has been identified as an effective solution for enhancing subgrade performance to withstand imposed traffic. This study evaluated the performance of unreinforced and geosynthetic-reinforced subgrades in Nebraska to quantify the contribution of geosynthetics to unpaved layer systems.

The strength and stiffness of different soil subgrades were assessed through unconfined compressive strength tests and repeated load triaxial (RLT) tests, which …


Smart Automatic Modal Hammer Predictor–Corrector Approach For Accurate Excitation Of Dynamical Systems, Mohammad Nasr Aug 2024

Smart Automatic Modal Hammer Predictor–Corrector Approach For Accurate Excitation Of Dynamical Systems, Mohammad Nasr

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

This research introduces an innovative solution that revolutionizes the study of linear and nonlinear dynamical systems—a smart automatic modal hammer. With its affordability and intelligent capabilities, this automatic modal hammer becomes an invaluable tool for research and industry, enabling repeatable strikes with precise force control. This system's significance becomes particularly evident when studying nonlinear systems, which heavily rely on the excitation level for their dynamics. By offering a cost-effective design this proposed system proves to be robust in accelerating research on nonlinear dynamics, providing researchers with an efficient and accessible means to delve deeper into these complex systems. The proposed …


Studies Of Exotic Electronic, Optical, And Electrochemical Properties In Nanoparticle Assembly And Graphene, Jay Min Lim Aug 2024

Studies Of Exotic Electronic, Optical, And Electrochemical Properties In Nanoparticle Assembly And Graphene, Jay Min Lim

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

It is well known that exotic properties and phenomena emerge as structural dimensions shrink to nanoscales. We self-assembled one-dimensional chains of gold nanoparticles in solution and quantified the growth process by monitoring the redshift of localized surface plasmon resonance (LSPR). Curiously, the redshift stopped while the chains continued to rearrange as manifested by gradual reduction in the LSPR peak. Using electromagnetic simulations, we quantitatively explained the phenomena as a rapid “addition-polymerization” followed by a sharp transition to “condensation-process.” Next, recognizing the significant electric field enhancement in the interparticle gap, a photoluminescent-active Eu3+ ion was used to probe Surface-Enhanced Photoluminescence …