Engineering Commons^™

Hierarchical Ni-Mn Ldhs@Cuc2O4 Nanosheet Arrays-Modified Copper Mesh: A Dual-Functional Material For Enhancing Oil/Water Separation And Supercapacitors, Yue Wu, Guangyuan Lu, Ping Xu, Tian Zhang, Huaqiang He, Shaojun Yuan

Department of Civil and Environmental Engineering: Faculty Publications

The pursuit of superhydrophilic materials with hierarchical structures has garnered significant attention across diverse application domains. In this study, we have successfully crafted Ni-Mn LDHs@CuC₂O₄ nanosheet arrays on a copper mesh (CM) through a synergistic process involving chemical oxidation and hydrothermal deposition. Initially, CuC₂O₄ nanosheets were synthesized on the copper mesh, closely followed by the growth of Ni-Mn LDHs nanosheets, culminating in the establishment of a multi-tiered surface architecture with exceptional superhydrophilicity and remarkable underwater superoleophobicity. The resultant Ni-Mn LDHs@CuC₂O₄ CM membrane showcased an unparalleled amalgamation of traits, including superhydrophilicity, underwater …

Resilin Distribution And Abundance In Apis Mellifera Across Biological Age Classes And Castes, Audrey Anderson, Noah Keime, Chandler Fong, Andrew Kraemer, Carol Fassbinder-Orth

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The presence of resilin, an elastomeric protein, in insect vein joints provides the flexible, passive deformations that are crucial to flapping flight. This study investigated the resilin gene expression and autofluorescence dynamics among Apis mellifera (honey bee) worker age classes and drone honey bees. Resilin gene expression was determined via ddPCR on whole honey bees and resilin autofluorescence was measured in the 1m-cu, 2m-cu, Cu-V, and Cu2-V joints on the forewing and the Cu-V joint of the hindwing. Resilin gene expression varied significantly with age, with resilin activity being highest in the pupae. Autofluorescence of the 1m-cu and the Cu-V …

Stomatal Opening Efficiency Is Controlled By Cell Wall Organization In Arabidopsis Thaliana, Sedighe Keynia, Leila Jaafar, You Zhou, Charles T. Anderson, Joseph A. Turner

Department of Mechanical and Materials Engineering: Faculty Publications

Stomatal function in plants is regulated by the nanoscale architecture of the cell wall and turgor pressure, which together control stomatal pore size to facilitate gas exchange and photosynthesis. The mechanical properties of the cell wall and cell geometry are critical determinants of stomatal dynamics. However, the specific biomechanical functions of wall constituents, for example, cellulose and pectins, and their impact on the work required to open or close the stomatal pore are unclear. Here, we use nanoindentation in normal and lateral directions, computational modeling, and microscopic imaging of cells from the model plant Arabidopsis thaliana to investigate the precise …

Water-Energy-Food Linkages In Community Smallholder Irrigation Schemes: Center Pivot Irrigation In Rwanda, Ankit Chandra, Derek M. Heeren, Lameck O. Odhiambo, N. Brozovic

Daugherty Water for Food Global Institute: Faculty Publications

Water, energy, and food are linked in intricate ways in irrigated agriculture and understanding the interplay of these components is crucial for sustainable and profitable crop production, particularly in smallholder setting such as in sub-Saharan Africa. This study evaluates water-energy-food linkages, engineering and economic performance, irrigation decision making, and challenges faced around water management in a community-based mechanized irrigation scheme in Rwanda. The research is the first to analyze such as scheme, which uses technology typically used by large farmers in a smallholder setting. The study investigates the variation in water requirements and the relationship and impacts of this variability …

Reaction Steps In Heterogeneous Photocatalytic Oxidation Of Toluene In Gas Phase—A Review, Yerzhigit Tulebekov, Zhandos Orazov, Bagdat Satybaldiyev, Daniel D. Snow, Raphaël Schneider, Bolat Uralbekov

Nebraska Water Center: Faculty Publications

A review of the current literature shows there is no clear consensus regarding the reaction mechanisms of air-borne aromatic compounds such as toluene by photocatalytic oxidation. Potential oxidation reactions over TiO₂ or TiO₂-based catalysts under ultraviolet and visible (UV/VIS) illumination are most commonly considered for removal of these pollutants. Along the pathways from a model pollutant, toluene, to final mineralization products (CO₂ and H₂O), the formation of several intermediates via specific reactions include parallel oxidation reactions and formation of less-reactive intermediates on the TiO₂ surface. The latter may occupy active adsorption sites and …

Energy Dissipation Optimization For Circular Culverts, David M. Admiraal, Chi Zhang

Nebraska Department of Transportation: Research Reports

Two types of energy dissipation devices at circular culvert outlets were investigated: full-length weirs and staggered weirs. Related literature was reviewed; a model broken-back circular culvert and dissipation basin was built; instrumentation was installed to measure discharge, piezometric head, and velocities; and four sizes of full-length and staggered weirs were tested over a range of discharges and tailwaters. Weir heights ranged from D/8 to 4D/8, in which D was the culvert diameter. The two weir types were subjected to two styles of tests: (1) tests unaffected by tailwater and (2) tailwater-influenced tests. For tall full-length weirs (3D/8 and 4D/8), basin …

Integrating Glycolysis, Citric Acid Cycle, Pentose Phosphate Pathway, And Fatty Acid Beta‑Oxidation Into A Single Computational Model, Sylwester M. Kloska, Krzysztof Pałczyński, Tomasz Marciniak, Tomasz Talaśka, Beata J. Wysocki, Paul H. Davis, Tadeusz A. Wysocki

Department of Electrical and Computer Engineering: Faculty Publications

The metabolic network of a living cell is highly intricate and involves complex interactions between various pathways. In this study, we propose a computational model that integrates glycolysis, the pentose phosphate pathway (PPP), the fatty acids beta-oxidation, and the tricarboxylic acid cycle (TCA cycle) using queueing theory. The model utilizes literature data on metabolite concentrations and enzyme kinetic constants to calculate the probabilities of individual reactions occurring on a microscopic scale, which can be viewed as the reaction rates on a macroscopic scale. However, it should be noted that the model has some limitations, including not accounting for all the …

Plant Height Estimation Using Rtk-Gnss Enabled Unmanned Aerial Vehicle (Uav) Photogrammetry, Pascal Izere

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Using Unmanned Aerial Vehicle (UAV) based remote sensing technology to provide high-throughput plant phenotypic traits has shown a great potential of eliminating manual measurements. For example, the use of UAV imaging to estimate plant height is of great interest to plant breeders and agronomists. Height is linked to a plant’s physical growth, light competition, health, biomass, and yield; thus, its accurate estimation is crucial in breeding. Conventionally, accurate height estimation by UAV platforms relies heavily on the use of ground control points (GCPs) for geometric calibration due to the relatively low positioning accuracy of regular differential global navigation satellite system …

Truck Platooning Effects On Girder Bridges: Phase Ii-Service, Joshua Steelman, Jay Puckett, Daniel Linzell, Bowen Yang

Nebraska Department of Transportation: Research Reports

Truck platooning—wirelessly linking two or more trucks to travel in a closely spaced convoy—is federally promoted to save fuel, improve the environment, and improve traffic operations. Platooning places trucks much closer than current design codes anticipate. While this strategy can provide higher fuel efficiency, it also can potentially overload structures. Previous reliabilitybased studies (Steelman et al., 2021; Yang et al., 2021) have focused on the Strength I limit state and have shown that trucks can operate at weights exceeding standard legal load limits even with short headways at operating-level reliability. However, service limit states in the AASHTO LRFD Bridge Design …

Influence Of Ultrasound Machine Settings On Quantitative Measures Derived From Spatial Frequency Analysis Of Muscle Tissue, Scott K. Crawford, Stephanie A. Kliethermes, Bryan C. Heiderscheit, Greg Bashford

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Background Ultrasound is a powerful tool for diagnostic purposes and provides insight into both normal and pathologic tissue structure. Spatial frequency analysis (SFA) methods characterize musculoskeletal tissue organization from ultrasound images. Both sonographers in clinical imaging and researchers may alter a minimized range of ultrasound settings to optimize image quality, and it is important to know how these small adjustments of these settings affect SFA parameters. The purpose of this study was to investigate the effects of making small adjustments in a typical default ultrasound machine setting on extracted spatial frequency parameters (peak spatial frequency radius (PSFR), Mmax, Mmax%, and …

Characterizing Feedlot Feed Using Depth Cameras And Imaging Technology, Jean Niwenshuti

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Imaging technology is a growing field that provides solutions in many areas from manufacturing to agriculture. Through previous research, imaging technologies have been studied in livestock farming to monitor the animal’s health and welfare in the production process. However, the feedlot industry is still behind in validating the feasibility to use some of these technologies nor to adopt such technologies to address challenges the industry is facing, such as lack of skilled labor.This work proposes using novel imaging methods to identify feed types and estimate the amount of feed remaining in a typical Midwestern feedlot feed bunk. These methods have …

Potential Of Mirnas In Plasma Extracellular Vesicle For The Stratification Of Prostate Cancer In A South African Population, Dada Oluwaseyi Temilola, Martha Wium, Juliano Paccez, Azola Samkele Salukazana, Hasan H. Otu, Giuseppina M. Carbone, Lisa Kaestner, Stefano Cacciatore, Luiz Fernando Zerbini

Department of Electrical and Computer Engineering: Faculty Publications

Prostate cancer (PCa) is the most common cause of cancer death among African men. The analysis of microRNAs (miRNAs) in plasma extracellular vesicles (EVs) can be utilized as a non-invasive tool for the diagnosis of PCa. In this study, we used small RNA sequencing to profile miRNAs cargo in plasma EVs from South African PCa patients. We evaluated the differential expression of miRNAs between low and high Gleason scores in the plasma EVs of South African patients and in the prostatic tissue from data available in the Cancer Genome Atlas (TCGA) Data Portal. We identified 7 miRNAs differently expressed in …

Flex-Ro: Development And Testing Of A Semi-Autonomous Robotic Planter, Ian Tempelmeyer

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

The need for more crop production with minimal negative environmental impact is a continuing pursuit around the world. As the population continues to increase at an exponential rate, the demand for food, fiber, fuel, and energy also increases. Robotics and automation are seen as one of the useful technology tools to increase field productivity. This work specifically focuses on addressing labor challenges for one of the most important field operations, planting. A robotic planter unit was designed as part of this work that mounted on unmanned ground vehicle (UGV) to perform autonomous planting operation in a 1 ha (2.5 acre) …

Integration Of Meta-Multi-Omics Data Using Probabilistic Graphs And External Knowledge, Handan Can, Sree K. Chanumolu, Barbara D. D., Sophie Alvarez, Michael J. Naldrett, Gülhan Ünlü, Hasan H. Otu

Department of Electrical and Computer Engineering: Faculty Publications

Multi-omics has the promise to provide a detailed molecular picture of biological systems. Although obtaining multi-omics data is relatively easy, methods that analyze such data have been lagging. In this paper, we present an algorithm that uses probabilistic graph representations and external knowledge to perform optimal structure learning and deduce a multifarious interaction network for multi-omics data from a bacterial community. Kefir grain, a microbial community that ferments milk and creates kefir, represents a self-renewing, stable, natural microbial community. Kefir has been shown to have a wide range of health benefits. We obtained a controlled bacterial community using the two …

A Portable, Low Power Radiation Detection And Identification System For High Count Rate, Long Term Monitoring, Samuel J. Murray

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

This dissertation presents the design of a novel radiation detection and identification system that can operate continuously over a period of 8 days while detecting at 30,000 counts per second, consuming a total of 11 mW. The entire system is highly integrated, containing a gamma ray detector, a high voltage detector power supply, and a multichannel analyzer (MCA) system-on-a-chip (SoC), which are all combined into a compact form using a multi-level, configurable printed circuit board design. The MCA SoC, fabricated using a 65 nm CMOS technology, features two enabling resources to allow low power detections at high count rates for …

Seek And Classify: End-To-End Joint Multi-Signal Detection And Classification Using Deep Learning, Prashant Subedi

School of Computing: Dissertations, Theses, and Student Research

The rise in the use of wireless communication has led to the problem of spectrum scarcity in licensed bands. The popularity of Internet of Things (IoT) requires innovative solutions that maximize the use of available spectrum to support the increasing number of connected devices. This thesis tackles two significant problems in wireless communication: the need for efficient spectrum sensing techniques and the scarcity of large, diverse raw in-phase (I) and quadrature (Q) datasets.

The ability to detect and classify modulation of the signals efficiently can enable a cognitive radio to monitor the spectrum activity in real time and utilize unused …

Experimental Study Of Linux Flightsize Estimation, Mingrui Zhang

School of Computing: Dissertations, Theses, and Student Research

Transmission Control Protocol (TCP) is a fundamental Internet protocol responsible for controlling and coordinating the Internet traffic. As a result, TCP significantly influences the overall performance and stability of the Internet. One critical information required by a TCP connection to make decisions is FlightSize, which is the total amount of outstanding data contributed by the connection to the Internet. The FlightSize information is used by a TCP connection to determine its future sending rate and also avoid traffic congestion and collapse in the Internet. Consequently, an inaccurate estimation of FlightSize can result in degraded performance and instability of the Internet. …

Assessment Of Integrated Nutrient Management Practices On Soil Health And Nitrogen Efficiency In Cropping Systems, María José Oviedo Ventura

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Groundwater quality in Nebraska is threatened by non-point source contributions of nitrate-nitrogen, primarily by agricultural systems. Intensive crop and livestock production that neglects the value of manure in crop fertility plans can contribute to soil degradation and natural resource impairment. The purpose of this study is to evaluate opportunities to improve agricultural nutrient management throughout Nebraska by quantifying opportunities for manure distribution, evaluating soil health implications of organic and inorganic soil amendments, and assessing nutrient management practices focused on reducing nitrate leaching in agricultural soils.

This study described in Chapter 2 provides a spatial illustration of nitrogen and phosphorus balances …

Prairie Protector: Student Development Of Systems Thinking Habits In The Context Of Agroecosystems, Erin Ingram, Jennifer Keshwani

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Introduction: The Great Plains ecosystem offers an opportunity for young people to gain knowledge about intricate systems through practical learning. The spread of woody plants into grasslands, known as the “Green Glacier,” poses a risk to biodiversity and animal production. Although effective management strategies exist, some land managers are reluctant to use them. It is critical to cultivate a scientifically literate population that can think systematically and make informed decisions based on STEM principles to address such complex agroecosystem problems.

Methods: In this study, semi-structured focus group discussions with high school students were analyzed to determine whether Prairie …

Drinking Water Quality Management Progress In Ontario, Two Decades After Walkerton, Megan Fuller, Emma Wells, Laith Furatian, Ian Douglas, Kaycie Lane

Department of Civil and Environmental Engineering: Faculty Publications

Following the waterborne disease outbreak in Walkerton, Ontario, the province made significant efforts to implement recommendations of the public inquiry that resulted. As Ontario reformed its drinking water sector, other jurisdictions were advancing risk-based quality management frameworks for drinking water, including the World Health Organization (WHO) through its water safety plan (WSP) framework. Two decades after the Walkerton tragedy, this paper seeks to: (i) evaluate alignment of Ontario’s Drinking Water Quality Management Standard (DWQMS) with the WSP framework (ii) review readily available data for evidence that Ontario’s DWQMS implementation has improved drinking water safety and promoted a preventive approach through …

Energy Dissipation Optimization For Circular Culverts, Chi Zhang

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

The principal goal of the current research is to develop and improve weir-based energy dissipator designs at the outlets of circular culverts. In the present case, we are interested in full-length weirs and staggered weirs. A review of related literature was completed and reported; a test facility was carefully designed and constructed to collect flow information in a basin downstream of a model broken-back circular culvert; instrumentation was installed to measure discharges, streamwise depths, and velocities. Both full-length and staggered weirs were tested over a range of discharges and tailwaters. The two types of weirs were subjected to two types …

Investigation And Modification Of Single-Post Aluminum Sign Supports For Mash Crashworthiness, Rodrigo Quintero

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

Traffic signs are used to display information to drivers and are one of the most commonly encountered roadside structures. Although they are a vital traffic control device, signs can pose a significant safety risk to errant drivers due to their extensive placement and proximity to the roadway. Therefore, traffic signs and their supports must be designed with crashworthiness in mind to reduce the likelihood of injury in the event of a vehicle impact. Prior to 2009, these systems were evaluated using the crash testing criteria found in the National Cooperative Highway Research Program (NCHRP) Report No. 350 [1]. Currently, they …

Twin-Solute, Twin-Dislocation And Twin-Twin Interactions In Magnesium, Materials Yue, Jian Wang, Jian-Feng Nie

Department of Mechanical and Materials Engineering: Faculty Publications

Magnesium alloys have received considerable research interest due to their lightweight, high specific strength and excellent castability. However, their plastic deformation is more complicated compared to cubic materials, primarily because their low-symmetry hexagonal closepacked (hcp) crystal structure. Deformation twinning is a crucial plastic deformation mechanism in magnesium, and twins can affect the evolution of microstructure by interacting with other lattice defects, thereby affecting the mechanical properties. This paper provides a review of the interactions between deformation twins and lattice defects, such as solute atoms, dislocations and twins, in magnesium and its alloys. This review starts with interactions between twin boundaries …

A Unified Switched Nonlinear Dynamic Model Of An Electric Vehicle For Performance Evaluation, Dibyendu Khan, Kuntal Mandal, Anjan Kumar Ray, Abdelali El Aroudi

Department of Electrical and Computer Engineering: Faculty Publications

The advanced modeling and estimation of overall system dynamics play a vital role in electric vehicles (EVs), as the selection of components in the powertrain and prediction of performance are the key market qualifiers. The state-space averaged model and small-signal transfer function model are useful for assessing long-term behavior in system-level analysis and for designing the controller parameters, respectively. Both models take less computation time but ignore the high-frequency switching dynamics. Therefore, these two models could be impractical for the development and testing of EV prototypes. On the other hand, the multi-domain model in available simulation tools gives in-depth information …

An Ai-Based Intervention For Improving Undergraduate Stem Learning, Mohammad Rashedul Hasan, Bilal Khan

Department of Electrical and Computer Engineering: Faculty Publications

We present results from a small-scale randomized controlled trial that evaluates the impact of just-in-time interventions on the academic outcomes of N = 65 undergraduate students in a STEM course. Intervention messaging content was based on machine learning forecasting models of data collected from 537 students in the same course over the preceding 3 years. Trial results show that the intervention produced a statistically significant increase in the proportion of students that achieved a passing grade. The outcomes point to the potential and promise of just-in-time interventions for STEM learning and the need for larger fully-powered randomized controlled trials.

Atomistic Simulations Of Twin Facets Associated With Three-Dimensional { []011 } Twins In Magnesium, Qiyu Zeng, Mingyu Gong, Houyu Ma, Yao Shen, Jian-Feng Nie, Jian Wang, Yue Liu

Department of Mechanical and Materials Engineering: Faculty Publications

Twinning is a deformation mechanism that creates three-dimensional (3D) twin domains through the migration of twin facets. This occurs via the nucleation and glide of twinning disconnections (TDs), which can pile up to create twin facets. A comprehensive under- standing of twin facets associated with 3D twins, including their atomic structures and energies, is crucial for understanding deformation twinning. In this study, we propose a molecular statics/dynamics (MS/MD) approach to determine characteristic twin facets enclosing 3D non-equilibrium/equilibrium { [] 011 } twin domains, which has been much less studied than the counterpart { [] 012 } twin domains. The stability …

The Essential Work Of Fracture In Peridynamics, Christer Stenström, Kjell Eriksson, Florin Bobaru, Stefan Golling, Pär Jonsén

Department of Mechanical and Materials Engineering: Faculty Publications

In this work, the essential work of fracture (EWF) method is introduced for a peridynamic (PD) material model to characterize fracture toughness of ductile materials. First, an analytical derivation for the path-independence of the PD J -integral is provided. Thereafter, the classical J -integral and PD J-integral are computed on a number of analytical crack problems, for subsequent investigation on how it performs under large scale yielding of thin sheets. To represent a highly nonlinear elastic behavior, a new adaptive bond stiffness calibration and a modified bonddamage model with gradual softening are proposed. The model is employed for two …

Generation Of Vector Vortex Wave Modes In Cylindrical Waveguides, Md Khadimul Islam, Pawan Gaire, Arjuna Madanayake, Shubhendu Bhardwaj

Department of Electrical and Computer Engineering: Faculty Publications

In this paper, we propose a method to generate Vector Vortex Modes (VVM) inside a metallic cylindrical waveguide at microwave frequencies and demonstrate the experimental validation of the concept. Vector vortex modes of EM waves can carry both spin and orbital angular momentum as they propagate within a tubular medium. The existence of such waves in tubular media can be beneficial to wireless communication in such structures. These waves can carry different orbital angular momentum and spin angular momentum, and therefore, they feature the ability to carry multiple orthogonal modes at the same frequency due to spatial structure of the …

Crashworthy Perforated Square Steel Tube (Psst) Mailbox Support – Phase I, Robert W. Bielenberg, Cody S. Stolle, Ronald K. Faller

Nebraska Department of Transportation: Research Reports

Federal requirements have made it mandatory that safe mailbox support systems be designed to yield or breakaway whenimpacted by a vehicle. The Nebraska Department of Transportation (NDOT) has previously used a non-proprietary, U-channel post mailbox support that was evaluated at the Midwest Roadside Safety Facility (MwRSF) in the 1980's. NDOT desires that the mailbox support be updated to meet MASH 2016 TL-3 safety performance criteria and be redesigned to use perforated square steel tubing (PSST) for the mailbox support post.

The objective of this research project is to develop a non-proprietary mailbox support using PSST support posts that is MASH …

Mesoporous Particle Embedded Nanofibrous Scaffolds Sustain Biological Factors For Tendon Tissue Engineering, Chiara Rinoldi, Ewa KijeńSka-GawrońSka, Marcin Heljak, Jakub Jaroszewicz, Artur KamińSki, Ali Khademhosseini, Ali Tamayol, Wojciech Swieszkowski

Department of Mechanical and Materials Engineering: Faculty Publications

In recent years, fiber-based systems have been explored in the frame of tissue engineering due to their robustness in recapitulating the architecture and mechanical properties of native tissues. Such scaffolds offer anisotropic architecture capable of reproducing the native collagen fibers’ orientation and distribution. Moreover, fibrous constructs might provide a biomimetic environment for cell encapsulation and proliferation as well as influence their orientation and distribution. In this work, we combine two fiber fabrication techniques, such as electrospinning and wet-spinning, in order to obtain novel cell-laden 3D fibrous layered scaffolds which can simultaneously provide: (i) mechanical support; (ii) suitable microenvironment for 3D …