Civil and Environmental Engineering Commons^™

Axial Hypersensitivity Is Associated With Aberrant Nerve Sprouting In A Novel Model Of Disc Degeneration In Female Sprague Dawley Rats, David J. Lillyman, Fei San Lee, Evie C. Barnett, Tyler J. Miller, Moreno Lozano Alvaro, Henry C. Drvol, Rebecca A. Wachs

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Chronic low back pain is a global socioeconomic crisis and treatments are lacking in part due to inadequate models. Etiological research suggests that the predominant pathology associated with chronic low back pain is intervertebral disc degeneration. Various research teams have created rat models of disc degeneration, but the clinical translatability of these models has been limited by an absence of robust chronic painlike behavior. To address this deficit, disc degeneration was induced via an artificial annular tear in female Sprague Dawley rats. The subsequent degeneration, which was allowed to progress for 18-weeks, caused a drastic reduction in disc volume. Furthermore, …

Tracing Geochemical Sources And Health Risk Assessment Of Uranium In Groundwater Of Arid Zone Of India, P. Pandit, Atul Saini, Sabarathinam Chidambaram, Vinod Kumar, Banjarani Panda, A. L. Ramanathan, Netrananda Sahu, A. K. Singh, Rohit Mehra

Nebraska Water Center: Faculty Publications

Water quality degradation and metal contamination in groundwater are serious concerns in an arid region with scanty water resources. This study aimed at evaluating the source of uranium (U) and potential health risk assessment in groundwater of the arid region of western Rajasthan and northern Gujarat. The probable source of vanadium (V) and fluorine (F) was also identified. U and trace metal concentration, along with physicochemical characteristics were determined for 265 groundwater samples collected from groundwater of duricrusts and palaeochannels of western Rajasthan and northern Gujarat. The U concentration ranged between 0.6 and 260 μg L⁻¹ with a mean …

Evaluation Of An Equivalent Mean Grain Size Diameter To Rationally Predict The Erodibility Of Fine Riverbed Soils In Nebraska, Basil Abualshar

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

The erosion of riverbed soils under the bridges is one of the major reasons that cause bridge closure or failure leading to a significant effect on the local economy. One of the commonly used methods to predict the erosion rate of soils is the excess shear stress method, which is based on two parameters describing the erodibility behavior; the erodibility coefficient and the critical shear stress. On the other hand, studies showed that the mean grain size diameter D₅₀ could be correlated to the erosion resistance of soils, usually for cohesionless soils but not for cohesive soils. It is …

Outdoor Laboratory And Testbed For Bridge Health, Richard L. Wood, Mitra Nasimi, Bowen Yang, Christine E. Wittich, Joshua Steelman, Jay Puckett, Daniel Linzell, Jinying Zhu, Mohammad Ebrahim Mohammadi

Nebraska Department of Transportation: Research Reports

Due to the aging problem of bridges and the limited financial resources in the United States, it is necessary to form a deeper understanding of existing, aging bridges in an effort to extend their in-service life. To address this problem, researchers from the University of Nebraska-Lincoln (UNL) and engineers from the Nebraska Department of Transportation (NDOT) identified three, out-of-service bridges (two steel and one concrete) to establish the Nebraska Outdoor Bridge Lab (NOBL). As the first step in NOBL’s development, geometric surveys of the current condition of each bridge were produced using lidar and Structure-from-Motion (SfM). This data contributed to …

Data-Driven Prioritization And Empirical Predictions For Bridge Scour In Nebraska, Richard L. Wood, Awgku Ahmad Hashim B. Awg Bolhasan, Basil Abualshar, Christine E. Wittich, Chung R. Song, Junke Guo, Mohammad Ebrahim Mohammadi, Mitra Nasimi, Yijun Liao

Nebraska Department of Transportation: Research Reports

The effect of scour at the bridge substructure results in an increase in the vulnerability of the overall bridge stability. Previous studies have found that current guidelines are often overly-conservative with respect to scour. This project aims to provide guidance on hydraulic modeling parameters and reasonable scour estimates specific to Nebraska conditions. This will enable engineers to assess bridge sites for scour more precisely for efficient and effective design and countermeasures. Four sites were surveyed for scour changes between the period of December 9, 2020, to April 20, 2021. At these four sites, overland and bathymetry survey data were collected. …

Single-Pass Inline Pipeline 3d Reconstruction Using Depth Camera Array, Zhexiong Shang, Zhigang Shen

Department of Construction Engineering and Management: Faculty Publications

A novel inline inspection (ILI) approach using depth cameras array (DCA) is introduced to create high-fidelity, dense 3D pipeline models. A new camera calibration method is introduced to register the color and the depth information of the cameras into a unified pipe model. By incorporating the calibration outcomes into a robust camera motion estimation approach, dense and complete 3D pipe surface reconstruction is achieved by using only the inline image data collected by a self-powered ILI rover in a single pass through a straight pipeline. The outcomes of the laboratory experiments demonstrate one-millimeter geometrical accuracy and 0.1-pixel photometric accuracy. …

Assessing The Effectiveness Of Problem-Based Learning Across Two Concrete Construction Courses, Anthony Torres, Jiong Hu, Vedaraman Sriraman, Araceli Martínez-Ortiz, Jorge Membrillo-Hernández

Department of Civil and Environmental Engineering: Faculty Publications

The goal of this study is to assess the effectiveness of a Problem-Based Learning (PBL) pedagogy that was implemented in two different concrete construction courses. Both courses are a part of an industry focused four-year undergraduate concrete degree program. One of the classes focused on concrete problems, diagnosis, and repair of existing concrete, while the other class focused on handling and management methods of various concrete mixtures. In both courses, a PBL pedagogy was implemented such that students were self-learning and discovering the knowledge through an action-research case study. The action-research case study was specific to the course outcomes relevant …

A Segmentation-Guided Deep Learning Framework For Leaf Counting, Xijian Fan, Rui Zhou, Tardi Tjahjadi, Sruti Das Choudhury, Qiaolin Ye

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Deep learning-based methods have recently provided a means to rapidly and effectively extract various plant traits due to their powerful ability to depict a plant image across a variety of species and growth conditions. In this study, we focus on dealing with two fundamental tasks in plant phenotyping, i.e., plant segmentation and leaf counting, and propose a two-steam deep learning framework for segmenting plants and counting leaves with various size and shape from two-dimensional plant images. In the first stream, a multi-scale segmentation model using spatial pyramid is developed to extract leaves with different size and shape, where the fine-grained …

Towards A Cybersecurity Testbed For Agricultural Vehicles And Environments, Mark Freyhof, George Grispos, Santosh Pitla, Cody Stolle

Department of Agricultural and Biological Systems Engineering: Faculty Publications

In today’s modern farm, an increasing number of agricultural systems and vehicles are connected to the Internet. While the benefits of networked agricultural machinery are attractive, this technological shift is also creating an environment that is conducive to cyberattacks. While previous research has focused on general cybersecurity concerns in the farming and agricultural industries, minimal research has focused on techniques for identifying security vulnerabilities within actual agricultural systems that could be exploited by cybercriminals. Hence, this paper presents STAVE – a Security Testbed for Agricultural Vehicles and Environments – as a potential solution to assist with the identification of cybersecurity …

Intelligent Work Zone Using Automatic Queue Detection Systems, Li Zhao, Laurence Rilett, Ernest Tufuor

Nebraska Department of Transportation: Research Reports

This report documents the the evaluation of the effectiveness of the Advanced Queue Detection (AQD) systems installed on Interstate work zones in Nebraska. Specifically, (1) the system performance was verified by examining whether the messages displayed on the portable dynamic message signs (PDMS) were consistent with the underlying AQD logic; (2) the system efficacy was measured by determining whether driver speeds were reduced when warning messages were provided on the PDMS; and (3) the system safety impact was modeled using statistical models. It was found that overall, the AQD systems had an error rate of 0.7% – 2.3%. Drivers reduced …

A Physical Model Of Deadmans Run, Quinn Brandt

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

A physical model of Deadmans Run and a pair of railroad bridges was constructed to assess the impacts of the bridges on flood flows. Lower Platte South Natural Resources District is planning a series of improvements to Deadmans Run to improve flood conveyance capacity and remove approximately 500 homes and businesses from the floodplain. The rail bridges are located less than a mile from the confluence of Deadmans Run and Salt Creek, meaning the bridges present a significant bottleneck to the planned improvements. The physical model was used to characterize the drag effects caused by the bridges, which was used …

An Investigation Of Water Obstructions And Related Weather Conditions For Nebraska Roadways, Mark R. Anderson, Logan R. Bundy

Nebraska Department of Transportation: Research Reports

Roadway resilience across the 10,000 miles of road and 3,500 bridges in Nebraska is critical to the economic success of productionand logistics. In a state where historical flooding scenarios, such as the one in March 2019 that caused $150 million in damage,could potentially be increasing, it has become essential to understand the spatial and temporal distribution of high-frequency waterobstruction areas on roadways. Therefore, in order to further investigate these areas, the main objectives of this research were toperform statistical and spatial analyses to quantify the relationship between water obstructions and their associated meteorologicalconditions, and identify the potential linkages between water …

Estimating System And Traveler Costs Due To Lane Closures During Construction And Maintenance Operations, Ernest Tufuor, Li Zhao, Mm Haque, Laurence Rilett Ph.D., John Anderson, Eric Thompson

Nebraska Department of Transportation: Research Reports

Lane closures are used to facilitate activities related to road construction and maintenance or operations. However, there are economic costs associated with lane closures and these may accrue to both the traveling public as well as to traffic agencies. The Nebraska Governor’s office has identified maximizing the effectiveness of lane closures as a priority for the Nebraska Department of Transportation (NDOT). The goal of this project is to assist NDOT in effectively managing the operations of work zones to maximize the effectiveness of lane closures under Nebraska conditions. This report summarizes the findings of the current state of the practice …

Estimating System And Traveler Costs Due To Lane Closures During Construction And Maintenance Operations, Ernest Tufuor, Lianlin Zhao, Mm Shakiul Haque, Laurence Rilett, John Anderson, Eric Thompson

Nebraska Department of Transportation: Research Reports

Lane closures are used to facilitate activities related to road construction and maintenance or operations. However, there are economic costs associated with lane closures and these may accrue to both the traveling public as well as to traffic agencies. The Nebraska Governor’s office has identified maximizing the effectiveness of lane closures as a priority for the Nebraska Department of Transportation (NDOT). The goal of this project is to assist NDOT in effectively managing the operations of work zones to maximize the effectiveness of lane closures under Nebraska conditions. This report summarizes the findings of the current state of the practice …

Repair And Strengthening Of Concrete Bridges Using Ultra-High-Performance Concrete (Uhpc), Antony Kodsy

Department of Construction Engineering and Management: Dissertations, Theses, and Student Research

Reinforced/Prestressed concrete bridges are subjected to environmental effects that cause premature deterioration and require structural repair and strengthening during their service life. Currently 42% of bridges in the United States are at least 50 years old, and 7.5% of them are structurally deficient and need to be repaired/strengthened. Recently, new repair and strengthening techniques using Ultra-High-Performance concrete (UHPC) have shown a great potential with respect to performance, economy, and speed. UHPC is a new class of concrete that has mechanical and durability properties that are far superior to those of conventional concrete (CC). In addition, UHPC offers several advantages compared …

Development Of A Next-Generation Non-Proprietary Portable Concrete Barrier, Riley Ruskamp

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

Portable concrete barriers (PCBs) are segmented barriers made of precast concrete units that are connected by various load-bearing hardware. PCBs are typically used to shield work zones by redirecting errant vehicles upon impact with the barrier system. Most commonly-available PCBs have demonstrated performance issues arising from the sloped face of the barrier, which encourages vehicles to pitch and roll during impact, potentially resulting in vehicle rollover. Concerns also exist regarding the large dynamic deflections exhibited by these systems that can encroach upon the protected work zone or require anchoring to prevent large displacements. In addition to these concerns, the American …

Risk Assessment Of Hazardous Material Transportation For Small And Tribal Communities, Harrison Redepenning

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

By and large transportation of hazardous materials (HazMat) across the US is increasing, with truck transportation as the most common method of transport. Smaller communities (population <5,000) and Native American communities often lack the economic and political influence to quantify the dangers that HazMat incidents present to the immediate and surrounding areas. Lack of such information is an impediment to adequate preparedness in cases of HazMat incidents. This research focuses on assessing the vulnerability of small and tribal communities in Nebraska to the impacts of highway HazMat incidents. This was done by estimating the expected number and type of HazMat incidents per population in each community. Additionally, statistical analysis was conducted on actual HazMat incidents to determine if small and Native American communities experience a higher rate of incidents per population and per HazMat VMT than large and other small communities respectively. For per population, it was found small versus large is statistically significant while Native American versus other small communities was not significant. For per HazMat VMT, neither comparison was found to be statistically significant. In estimated HazMat incidents, actual HazMat incidents per population, and actual HazMat incidents per HazMat VMT, small communities had higher mean values than their large counterparts. Communities on Native American reservation land experienced a higher estimated and lower actual HazMat incident rate per population than other small communities. For actual HazMat incidents per VMT, Native American communities had a higher rate than other small communities.

Advisor: Aemal Khattak

Experimental And Numerical Analysis Of Soil-Geosynthetic Composite For A Geosynthetic-Reinforced Roadway System, Daniel Robertson

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

The present research conducted tests to evaluate the reinforcing performance of geosynthetics including three geogrids (GG1, GG2, and GG3) and one geotextile (GT) for three different soil types – sand, clay, and red shale. All geosynthetics showed great improvement under the lowest confining pressure. The report concluded that between the Large-Scale Direct Shear test, the Large-Scale Pullout Box, and the FLAC simulation, the three geogrids showed the greatest improvement when conducted with sand. The sand could withstand a much greater normal pressure than either clay or red shale. The biaxial geogrids, GG1 and GG3, had ideal results for lower stress …

Using Cost Simulation And Computer Vision To Inform Probabilistic Cost Estimates, Shu Jing Ding

Department of Construction Engineering and Management: Dissertations, Theses, and Student Research

Cost estimating is a critical task in the construction process. Building cost estimates using historical data from previously performed projects have long been recognized as one of the better methods to generate precise construction bids. However, the cost and productivity data are typically gathered at the summary level for cost-control purposes. The possible ranges of production rates and costs associated with the construction activities lack accuracy and comprehensiveness. In turn, the robustness of cost estimates is minimal. Thus, this study proposes exploring a range of cost and productivity data to better inform potential outcomes of cost estimates by using probabilistic …

Performance Of Concrete With Different Cement Finenesses And Nano-Activators, Brandon Faltin

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

The excessive shrinkage in modern concrete is the result of the construction industry in its quest to complete the job as soon as possible. In order to accomplish this, the fineness of cement was increased significantly in recent decades for a faster rate of strength gain. To combat the cement fineness and reverse the trend of shrinkage, the usage of coarse cements and nanoparticles should be strongly considered. The coarse cement is used to reduce the shrinkage of concrete, while the nanoparticle increases the early strength, alleviating the original concerns of reduced early strength when using coarse cement.

Work in …

Estimation Of Methane Emissions From Beef Cattle Manure In Nebraska, Noe Hernandez

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

The emission of methane from livestock production contributes to climate change. Cattle manure accounts for one-third of the total methane emission over the lifecycle of beef and dairy production and represents an opportunity to lower the environmental footprint of the beef industry. While models have been developed to estimate methane emissions from manure under certain types of manure storage methods, there is a lack of a user-friendly interface that agricultural or environmental engineers can use to estimate the methane emission from manure for specific regions. Therefore, the goal of this study was to build an interface to estimate methane emissions …

Surface Urban Energy And Water Balance Scheme (V2020a) In Vegetated Areas: Parameter Derivation And Performance Evaluation Using Fluxnet2015 Dataset, Hamidreza Omidvar, Ting Sun, Sue Grimmond, Dave Bilesbach, Andrew Black, Jiquan Chen, Zexia Duan, Zhiqiu Gao, Hiroki Iwata, Joseph P. Mcfadden

Department of Agricultural and Biological Systems Engineering: Faculty Publications

To compare the impact of surface–atmosphere exchanges from rural and urban areas, fully vegetated areas (e.g. deciduous trees, evergreen trees and grass) commonly found adjacent to cities need to be modelled. Here we provide a general workflow to derive parameters for SUEWS (Surface Urban Energy and Water Balance Scheme), including those associated with vegetation phenology (via leaf area index, LAI), heat storage and surface conductance. As expected, attribution analysis of bias in SUEWS-modelled QE finds that surface conductance (g_s) plays the dominant role; hence there is a need for more estimates of surface conductance parameters. The workflow …

Reducing Early-Age Shrinkage Cracks Of Bridge Decks And Rails, Soumitra Das, George Morcous, Jiong Hu

UNL Student Research Days Posters, Graduate

Early-age shrinkage cracking of concrete bridge decks and rails accelerates the penetration of water and chemicals which leads to reinforcement corrosion, delamination, and eventually spalling. All this results in shorter service life, road closure, and costly repair. Development of Low-cement concrete(LCC) mix to reduce early age shrinkage crack through aggregate grading optimization was done in this research work. This approach also reduces concrete cost ($15-$20/cyd) (15–25%) and its carbon footprint (≈15%).

Reflection Types And Students’ Viewing Of Feedback In A First-Year Engineering Course Using Standards-Based Grading, Heidi A. Diefes-Dux, Laura M. Cruz Castro

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Background: Feedback is one of the most powerful and essential tools for learning and assessment, particularly when it provides the information necessary to close an existing gap between actual and reference levels of performance. The literature on feedback has primarily focused on addressing strategies for providing effective feedback rather than aspects of students’ readiness to engage with feedback. Purpose/Hypothesis: This study investigated whether reflection, as a routine pedagogical intervention grounded in self-regulated learning theory, promotes the frequency with which students view feedback. Design/Method: A quasi-experimental design was employed to examine the relationship between the use of four different reflection types, …

Biogeosciences Perspectives On Integrated, Coordinated, Open, Networked (Icon) Science, D. Dwivedi, A. L.D. Santos, M. A. Barnard, T. M. Crimmins, A. Malhotra, K. A. Rod, K. S. Aho, S. M. Bell, B. Bomfim, F. Q. Brearley, H. Cadillo-Quiroz, J. Chen, C. M. Gough, E. B. Graham, C. R. Hakkenberg, L. Haygood, G. Koren, E. A. Lilleskov, L. K. Meredith, S. Naeher, Z. L. Nickerson, O. Pourret, H. S. Song, M. Stahl, N. Taş, R. Vargas, S. Weintraub-Leff

Department of Agricultural and Biological Systems Engineering: Faculty Publications

This article is composed of three independent commentaries about the state of Integrated, Coordinated, Open, Networked (ICON) principles in the American Geophysical Union Biogeosciences section, and discussion on the opportunities and challenges of adopting them. Each commentary focuses on a different topic: (a) Global collaboration, technology transfer, and application (Section 2), (b) Community engagement, community science, education, and stakeholder involvement (Section 3), and (c) Field, experimental, remote sensing, and real-time data research and application (Section 4). We discuss needs and strategies for implementing ICON and outline short- and long-term goals. The inclusion of global data and international community engagement are …

Land Use Influences The Composition And Antimicrobial Effects Of Propolis, Amara J. Orth, Emma H. Curran, Eric J. Haas, Andrew C. Kraemer, Audrey M. Anderson, Nicholas J. Mason, Carol A. Fassbinder-Orth

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Honey bee propolis is a complex, resinous mixture created by bees using plant sources such as leaves, flowers, and bud exudates. This study characterized how cropland surrounding apiaries affects the chemical composition and antimicrobial effects of propolis. The chemical composition and compound abundance of the propolis samples were analyzed using Gas Chromatography- Mass Spectrometry (GC-MS) and the antimicrobial effects were analyzed using the 50% minimum inhibitory concentration (MIC₅₀) assay against four relevant bee pathogens, Serratia marcescens, Paenibacillus larvae, Lysinibacillus sphaericus, and Klebsiella pneumoniae. Propolis composition varied significantly with apiary, and cropland coverage predicted mean sum abundance of …

Precipitation And Temperature Extremes And Association With Large-Scale Climate Indices: An Observational Evidence Over India, S Rehana, Pranathi Yeleswarapu, Ghouse Basha, Francisco Munoz-Arriola

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Climate change exposes more frequent natural hazards and physical vulnerabilities to the built and natural environments. Extreme precipitation and temperature events will have a significant impact on both the natural environment and human society. However, it is unclear whether precipitation and temperature extremes increase physical vulnerabilities across scales and their links with large-scale climate indices. This study investigates the relationship between precipitation and temperature extremes, as recommended by the Expert Team on Climate Change Detection and Indices (ETCCDI), and large scale climatological phenomenon indices (Indian Summer Monsoon Index (ISMI), Arctic Oscillation (AO), and North Atlantic Oscillation (NAO)), using India as …

Modeling Vapor Transfer In Soil Water And Heat Simulations: A Modularized, Partially-Coupled Approach, Zhuangji Wang, Dennis Timlin, David Fleisher, Wenguang Sun, Sahila Beegum, Sanai Li, Ya Chen, Vandimalla R. Reddy, Katherine Tully, Robert Horton

Nebraska Water Center: Faculty Publications

Coupled water and heat transfer models are widely used to analyze soil water content and temperature dynamics, evaluate agricultural management systems, and support crop growth modelling. In relatively dry soils, vapor transfer, rather than liquid water flux, becomes the main pathway for water redistribution. However, in some modularized soil simulators, e.g., 2DSOIL (Timlin et al., 1996), vapor transfer is not included, which may induce errors in soil water and heat modelling. Directly embedding vapor transfer into existing water and heat transfer modules may violate the modularized architecture of those simulators. Therefore, the objectives of this study are to design a …

Conceptual Framework To Integrate Economic Drivers Of Decision Making For Technology Adoption In Agriculture, Thiago L. Romanelli, Francisco Muñoz-Arriola, Andre F. Colaço

Department of Agricultural and Biological Systems Engineering: Faculty Publications

This study evaluates how much technology adoption could cost in a variety of crop-production scenarios. Cost-reduction simulations consider scenarios of higher input use efficiency such as reducing the usage of diesel, labor, irrigation, fertilizer, herbicide, and seed, among others. The scenarios aim to increase yields by integrating the effect of each input-reduction on the total operating costs. Agricultural production estimates for Nebraska in the US indicates that a technology that saves 1% of diesel is cost-effective, costing between USD 0.15/ha and USD 0.32/ha (for corn). Improvements on input use efficiency should be prioritized to incentivize technology development and adoption. This …

Maize Response To Coupled Irrigation And Nitrogen Fertilization Under Center Pivot, Subsurface Drip And Surface (Furrow) Irrigation: Growth, Development And Productivity, Suat Irmak, Ali T. Mohammed, Meetpal S. Kukal

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Water availability and water quality problems negatively impact agricultural productivity due to improper nitrogen (N) and irrigation management, which can also negatively affect environmental services. Coupled irrigation and N management practices must be developed and practiced for alleviating these challenges. Investigating crop growth and development and yield response to coupled irrigation and N management under different irrigation methods can aid in developing optimum agronomic management practices to enhance crop production efficiency. Field experiments were conducted in 2016 and 2017 growing seasons to measure and compare maize (Zea mays L.) grain yield, leaf area index (LAI), plant height (and their …