Engineering Commons^™

Research On High-Rap Mixtures With Rejuvenator - Field Implementation, Nitish R. Bastola, Mahdieh Khedmati, Hamzeh Haghshenas

Nebraska Department of Transportation: Research Reports

The use of Rejuvenating Agents (RAs), as Recycled Asphalt Pavement (RAP) modifiers, has been increasing over the past years. However, the field performance of asphalt mixtures containing high-RAP materials and modified with RAs has raised some concerns regarding the long-term performance of RAs. This study evaluated the laboratory and field performance of high-RAP mixtures with and without bio-oil RA. Three sets of plant-produced specimens were collected: 1) laboratory-compacted; 2) field-compacted and cored after paving; and 3) field-compacted and cored after one and two years. The Hamburg Wheel Tracking (HWT) test was used to evaluate the specimens' resistance to rutting and …

Low-Level Groundwater Atrazine In High Atrazine Usage Nebraska Counties: Likely Effects Of Excessive Groundwater Abstraction, Moses New-Aaron, Olufemi P. Abimbola, Raheleh Mohammadi, Oluwaseun Famojuro, Zaeema Naveed, Azar M Abadi, Jesse E. Bell, Shannon Bartelt-Hunt, Eleanor G. Rogan

Department of Biological Systems Engineering: Papers and Publications

Recent studies observed a correlation between estrogen-related cancers and groundwater atrazine in eastern Nebraska counties. However, the mechanisms of human exposure to atrazine are unclear because low groundwater atrazine concentration was observed in counties with high cancer incidence despite having the highest atrazine usage. We studied groundwater atrazine fate in high atrazine usage Nebraska counties. Data were collected from Quality Assessed Agrichemical Contaminant Nebraska Groundwater, Parameter–Elevation Regressions on Independent Slopes Model (PRISM), and water use databases. Descriptive statistics and cluster analysis were performed. Domestic wells (59%) were the predominant well type. Groundwater atrazine was affected by well depth. Clusters consisting …

Gis-Based Volunteer Cotton Habitat Prediction And Plant-Level Detection With Uav Remote Sensing, Tianyi Wang, Xiaohan Mei, J. Alex Thomasson, Chenghai Yang, Xiongzhe Han, Pappu Kumar Yadav, Yeyin Shi

Department of Biological Systems Engineering: Papers and Publications

Volunteer cotton plants germinate and grow at unwanted locations like transport routes and can serve as hosts for a harmful cotton pests called cotton boll weevils. The main objective of this study was to develop a geographic information system (GIS) framework to efficiently locate volunteer cotton plants in the cotton production regions in southern Texas, thus reducing time and economic cost for their removal. A GIS network analysis tool was applied to estimate the most likely routes for cotton transportation, and a GIS model was created to identify and visualize potential areas of volunteer cotton growth. The GIS model indicated …

Source Apportionment And Health Risk Assessment Of Nitrate In Foothill Aquifers Of Western Ghats, South India, Banajarani Panda, S. Chidambaram, Daniel D. Snow, Arindam Malakar, Dhiraj Kr Singh, L. Ramanathan

Nebraska Water Center: Faculty Publications

The present research reports the level of nitrate (NO₃^-), associated health risks and possible sources of contamination in groundwater from south India. Many samples (32%) are above or approaching the recommended level of NO₃^- for safe drinking water. The correlation analysis indicates different sources of NO₃^- contamination in different regions rather than a common origin. The isotopic measurements provide information about potential nitrogen sources contributing NO₃^- to the groundwater. Based on isotope analysis, the sources of NO₃^- in the groundwater of this region are likely to be from (a) …

Global Analysis Of Differential Gene Expression Within The Porcine Conceptus Transcriptome As It Transitions Through Spherical, Ovoid, And Tubular Morphologies During The Initiation Of Elongation, Sophie C. Walsh, Jeremy R. Miles, Brittney N. Keel, Lea A. Rempel, Elane C. Wright‐Johnson, Amanda K. Lindholm‐Perry, William T. Oliver, Angela K. Pannier

Department of Biological Systems Engineering: Papers and Publications

This study aimed to identify transcriptome differences between distinct or transitional stage spherical, ovoid, and tubular porcine blastocysts throughout the initiation of elongation. We performed a global transcriptome analysis of differential gene expression using RNA‐Seq with high temporal resolution between spherical, ovoid, and tubular stage blastocysts at specific sequential stages of development from litters containing conceptus populations of distinct or transitional blastocysts. After RNA‐Seq analysis, significant differentially expressed genes (DEGs) and pathways were identified between distinct morphologies or sequential development stages. Overall, 1898 significant DEGs were identified between distinct spherical and ovoid morphologies, with 311 total DEGs between developmental stages …

Injectable Decellularized Nucleus Pulposus Tissue Exhibits Neuroinhibitory Properties, Logan M. Piening, David J. Lillyman, Fei San Lee, Alvaro Moreno Lozano, Jeremy R. Miles, Rebecca A. Wachs

Department of Biological Systems Engineering: Papers and Publications

Background: Chronic low back pain (LBP) is a leading cause of disability, but treatments for LBP are limited. Degeneration of the intervertebral disc due to loss of neuroinhibitory sulfated glycosaminoglycans (sGAGs) allows nerves from dorsal root ganglia to grow into the core of the disc. Treatment with a decellularized tissue hydrogel that contains sGAGs may inhibit nerve growth and prevent discassociated LBP.

Methods: A protocol to decellularize porcine nucleus pulposus (NP) was adapted from previous methods. DNA, sGAG, α-gal antigen, and collagen content were analyzed before and after decellularization. The decellularized tissue was then enzymatically modified to be …

Irrigation Systems Management, Dean Eisenhauer, Derrel L. Martin, Derek M. Heeren, Glenn J. Hoffman

Department of Biological Systems Engineering: Papers and Publications

Management of irrigation systems should be based on the desired objectives or outcomes consistent with economic, energy, environmental, labor, water, and resource constraints. Goals can vary from maximizing profit, producing a contracted yield, optimizing water resource use, maintaining the quality of produce, or assuring an attractive landscape. Managers cannot achieve these goals without considering the performance of the irrigation system. This chapter discusses the basic characteristics of various irrigation systems, defines terms that quantify performance, describes basic requirements all systems must provide, gives a range of attributes for systems, and discusses how water supply requirements are governed by ET and …

Measuring Foundation Course Modulus Using Falling Weight Deflectometer, Light Weight Deflectometer, And Dynamic Cone Penetration, Bruce Barrett, Kellie Troxel, Brady Dresselhaus, David Hansen

Nebraska Department of Transportation: Research Reports

The purpose of this investigation was to determine the feasibility of measuring bituminous foundation course modulus under concrete roadways by comparing testing results derived before and after paving using FWD, Light Weight Deflectometer (LWD), and Dynamic Cone Penetrometer (DCP). The foundation course modulus was determined using FWD data and Darwin design software (‘93 AASHTO). Results from Phase I data collection, which occurred prior to pavement placement, provided a baseline for comparison. The maximum modulus was 398,000 PSI and the minimum was 85,000 PSI, yielding a range of 315,000 PSI and an average modulus of 123,000 PSI over the length of …

Application Of Biochar As Beneficial Additive In Concrete, Temirlan Barissov

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

Biochar is a high-carbon solid material produced via thermal decomposition of organic biomass in a low-oxygen environment. Characterized with high water retention properties and high alkalinity, biochar is generally used for soil amendment and fertilization purposes. This study is intended to explore the feasibility of using biochar as a beneficial additive of the most used manmade material, concrete. Literature review revealed several studies where biochar was successfully implemented as an additive in concrete. The beneficial influence of biochar on the mechanical characteristics of concrete is based on nucleation and densification effects. However, the internal microstructure, porosity and chemical composition of …

Modeling Watershed Sensitivity To Climate Change In Systems Affected By Discharge Of Mine Tailings, Johnette C. Shockley

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

For more than a century, a large volume of gold-mining tailings was deposited in Whitewood Creek and the Belle Fourche River, tributaries to the Cheyenne River in western South Dakota. Much of it still remains, and field and historical evidence indicates continued remobilization of tailings-containing alluvium in these bedrock-dominated channels. Both long-term, natural fluctuations in climate and anthropogenically driven changes can impact regional precipitation, temperature, hydrologic patterns, and ecosystem functions. Such changes have the potential to affect both the transport and distribution of arsenic-laden sediments and mechanical erosion that can undermine the stability of channel-bed and overbank material.

This study …

Measuring Foundation Course Modulus Using Falling Weight Deflectometer, Light Weight Deflectometer, And Dynamic Cone Penetration, Bruce Barrett, Kellie Troxel, Brady Dresselhaus, David Hansen

Nebraska Department of Transportation: Research Reports

Phase I results showed that FWD, LWD, and DCP provided valid results and trended with each other at the stations all three tests were run. This gives confidence that any test method is reliable when used on an exposed bituminous foundation course.

The results of Phase I and Phase II indicate that using FWD testing after concrete is built does not provide an accurate modulus of the foundation course. As demonstrated through the statistical analysis, foundation course moduli cannot be reliably calculated by using FWD on top of doweled concrete pavements and back-calculated using Darwin software or ME Design. Additionally, …

Detecting And Evaluating Cracks On Aging Concrete Members With Deep Convolutional Neural Networks, Brendan Barnes

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

Cracks in concrete structures are evaluated through a timely and subjective manual inspection. The location of cracks is often recorded in an inspection report where some cracks are measured. Although measurements or locations may not be necessary for all cracks observed in concrete members, if quantitative data can be gathered in an autonomous way, allowing measurement data to be used in tracking changes in spatial and temporal scales, this quantitative data can provide useful information not yet captured in the manual inspection process. This thesis aims to construct an image-based crack detection and evaluation pipeline that can assist health monitoring …

Corn Fiber As A Biomass Feedstock For Production Of Succinic Acid, Lisbeth Vallecilla-Yepez, Divya Ramchandran, Dianna Long, Rajib Saha, Mark R. Wilkins

Department of Biological Systems Engineering: Papers and Publications

The selection of an economical carbon source is a fundamental parameter to establish a successful industrial succinic acid (SA) bioprocess. In this work, corn fiber (CF), a renewable and an inexpensive source of carbohydrates, was successfully used for bioproduction of SA. Optimized liquid hot water (LHW) pretreatment followed by enzymatic hydrolysis were used to obtain corn fiber hydrolysate (CFH). Results in batch fermentation with Actinobacillus succinogenes showed that a control solution mimicking CFH produced 28.7 g/L of SA with a yield of 0.67 g SA/g sugars, while fermentation of CFH produced 27.8 g/L of SA with a yield of 0.61 …

Preferential Flow In Riparian Buffers: Current Research And Future Needs., Derek M. Heeren, Lucie Guertault, Kyle Mankin

Department of Biological Systems Engineering: Papers and Publications

Preferential flow in riparian buffers can substantially compromise their effectiveness in reducing contaminants from overland runoff. The objective of this article is to introduce a collection of five articles on current research into subsurface preferential flow measurement, visualization, modeling, and impacts on contaminant fate and transport at scales ranging from the subsurface pore scale to the plot scale to the watershed scale. This collection presents selected works from a broader invited session on “Preferential flow and piping in riparian buffers” at the 2020 ASABE Annual International Meeting. Major findings include: new methodologies, such as light transmission and geophysics, to characterize …

Association Between Aqueous Atrazine And Pediatric Cancer In Nebraska, Jagadeesh Puvvula, Shannon L. Bartelt-Hunt, Balkiss S. Ouattara, Alan S. Kolok, Jesse E. Bell, Eleanor G. Rogan

Department of Civil and Environmental Engineering: Faculty Publications

Agrichemicals, chemicals used to maximize crop and animal production, can lead to water quality concerns when these chemicals run off into surface and groundwater after precipitation events. In Nebraska, one such chemical is atrazine, a suspected carcinogen. This study evaluated the association between atrazine in surface and groundwater, in relation to the incidence of pediatric cancer in Nebraska watersheds over 30 years (1 January 1987 to 31 December 2016). The watersheds were grouped into four categories based on the average atrazine concentration over the study period, using quantile classification. The associations between atrazine (ground/surface) and pediatric cancer after adjusting for …

Greenhouse Gas Emissions And Drought Projections For Nebraska, Adam Liska

Adam Liska Papers

This lecture will focus on three issues. The first is a presentation of data from the first greenhouse gas emissions inventory for the State of Nebraska, which will be published in the coming weeks. In 2016, emissions from beef cattle made up 23% of net state emissions, and coal for electricity made up 23.7% of net state emissions. The second issue to be addressed are the impacts of the 2012 drought on agriculture in Nebraska and the region. The drought of 2012 indicates that future droughts in the 21^st century in the region can be a dominant influence on …

Recent Updates On Ions And Nutrients Uptake By Halotolerant Freshwater And Marine Microalgae In Conditions Of High Salinity, Abdul Mannan Zafar, Muhammad Asad Javed, Ashraf Aly Hassan, Khalid Mehmood, Endalkachew Sahle-Demessie

Department of Civil and Environmental Engineering: Faculty Publications

Algae is an appropriate natural resource to augment the optimal use of undesired ions in water and wastewater. Increasing algal cells, the consumption of particular ions, including chloride, nitrate, phosphate, and ammonium, provides a suitable way to optimize water treatment processes. Different algal species have the capability to survive in extreme salinities by developing resistance against osmotic pressure in saline water. The current study reviews the effect of salinity on algal biomass production, algal growth rate, chlorides, nitrates, phosphates, chemical oxygen demand (COD), total nitrogen, total phosphorus, and ammonium ions. Mainly algae cultivated in freshwater, synthetic brackish water, seawater, and …

Inter-Relationships Between Water Depletion And Temperature Differential In Row Crop Canopies In A Sub-Humid Climate, Jasreman Singh, Yufeng Ge, Derek M. Heeren, Elizabeth Walter-Shea, Christopher M.U. Neale, Suat Irmak, Wayne Woldt, Geng Bai, Sandeep Bhatti, Mitchell S. Maguire

Department of Biological Systems Engineering: Papers and Publications

Irrigation has a great impact on global food security as it contributes to the majority of the world’s agricultural food supply. It is essential to judiciously utilize water resources through efficient irrigation management since the majority of U.S. groundwater aquifers are rapidly depleting. Thus, quantification of the relationships between water depletion and environmental factors is important for understanding crop response to varying levels of water stresses that depletion can cause. The objectives of this research were to: 1) investigate the relationship between root zone water depletion (D_rw) and canopy temperature differential (ΔT) at different ranges of D_{rw …}

Https://Dot.Nebraska.Gov/Media/4yaemfil/M100-Nebraska-Buried-Archeological-Sites-Phase-Ii.Pdf, Anthony L. Layzell, Rolfe D. Mandel, Courtney L. Ziska, John R. Bozell

Nebraska Department of Transportation: Research Reports

This project developed a GIS to assist with the identification of deeply buried archeological sites in alluvial settings across Nebraska with the exception of the Sandhills region. Soil survey data, previous geoarcheological investigations, landform position, and other information was used to rank the potential of any stream valley setting as low, low-moderate, moderate-high, or high potential to contain buried soils (paleosols). While the presence of buried soils does not necessarily translate to presence of buried archeological sites, the potential for such sites is far greater in paleosols. The GIS can be used by NDOT and other agencies with statutory historic …

Assessment Of A Program For Sars-Cov-2 Screening And Environmental Monitoring In An Urban Public School District, John Crowe, Andy T. Schnaubelt, Scott Schmdit Bonne, Kathleen Angell, Julia Bai, Teresa Eske, Molly Nicklin, Catherine Pratt, Bailey White, Brodie Crotts-Hannibal, Nicholas Staffend, Vicki Herrera, Jeramie Cobb, Jennifer Connor, Julie Carstens, Jonell Tempero, Lori Bouda, Matthew Ray, James V. Lawler, W Scott Campbell, John-Martin Lowe, Joshua Santarpia, Shannon Bartelt-Hunt, Michael Wiley, David Brett-Major, Cheryl Logan, Jana Broadhurst

Department of Civil and Environmental Engineering: Faculty Publications

IMPORTANCE Scalable programs for school-based SARS-CoV-2 testing and surveillance are needed to guide in-person learning practices and inform risk assessments in kindergarten through 12th grade settings. OBJECTIVES To characterize SARS-CoV-2 infections in staff and students in an urban public school setting and evaluate test-based strategies to support ongoing risk assessment and mitigation for kindergarten through 12th grade in-person learning. DESIGN, SETTING, AND PARTICIPANTS This pilot quality improvement program engaged 3 schools in Omaha, Nebraska, for weekly saliva polymerase chain reaction testing of staff and students participating in in-person learning over a 5-week period from November 9 to December 11, 2020. …

Characterization Of Tea (Camellia Sinensis) Granules For Quality Grading Using Computer Vision System, Md Towfiqur Rahman, Sabiha Ferdous, Mariya Sultana Jenin, Tanjina Rahman Mim, Masud Alam, Muhammad Rashed Al Mamun

Department of Biological Systems Engineering: Papers and Publications

Tea (Camellia sinensis) has been found as an important medicinal beverage for human which is consumed all over the world. Primarily, the majority of tea is being cultivated in Asia and Africa, however it is commercially produced by more than 60 countries. Though substantial amount is produced, its processing system is still underdeveloped which leads to decrease in export opportunity as well as low monetary value. Moreover, the traditional method of tea grading and sorting is laborious, inefficient, and costly which ultimately produces the low-quality heterogeneous products. Processing and grading of tea granules after drying is very important …

Pollution Prevention/Environmental Sustainability For Industry, Bruce Dvorak

Department of Civil and Environmental Engineering: Faculty Publications

It has been 30 years since, in the United States, the Pollution Prevention Act of 1990 focused attention on reducing pollution through cost-effective changes in production, operation, and raw materials use. The pollution prevention approach was novel in focusing on increasing the efficiency of a process and reducing the amount of pollution generated at its source. Worldwide, industrial organizations embraced cleaner production approaches that result in reducing pollution at the source. Governmental bodies are exploring the best prevention and control polices for pollution and energy management. Since that time, the industry has successfully applied the three pillars of sustainability—economic, environmental, …

Exploring The Structural Uniformity And Integrity Of Protonic Ceramic Thin Film Electrolyte Using Wet Powder Spraying, Wuxiang Feng, Wei Wu, Congrui Grace Jin, Meng Zhou, Wenjuan Bian, Wei Tang, Joshua Y. Gomez, Richard Boardman, Dong Ding

Department of Civil and Environmental Engineering: Faculty Publications

Thin protonic ceramic electrolyte contributes to lower ohmic resistance and enhances electrochemical performance of protonic ceramic electrochemical cells. However, manufacturing of large-scale thin electrolyte remains a challenge. Wet powder spraying is an attractive technique to deposit <10 >μm thin electrolyte when advanced atomizing techniques and optimized spraying process are integrated. Here ultrasonic atomization is integrated in the wet powder spray technique to reduce the thickness of electrolyte. Moreover, a parametric study is conducted to optimize the wet powder spray process to deposit uniform and crack-free electrolyte film. It is illustrated that tuning of solid loading rates and spray passes can affect …

Validation Of The Mathematics Motivation Questionnaire (Mmq) For Secondary School Students, Logan Fiorella, So Yoon Yoon, Kinnari Atit, Jason R. Power, Grace Panther, Sheryl Sorby, David H. Uttal, Norma Veurink

Department of Civil and Environmental Engineering: Faculty Publications

Background: Motivation is critical for supporting persistence and achievement in science, technology, engineering, and mathematics (STEM) disciplines. In this study, we focus on the assessment of mathematics motivation among secondary school students. We provide validity and reliability evidence for the Mathematics Motivation Questionnaire (MMQ)—adapted from the Science Motivation Questionnaire designed for college students—using data from 2551 secondary students from seven states across the United States. Results: Exploratory and confirmatory factor analyses confirmed five latent factors of the MMQ indicated by 19 items: intrinsic value, self-regulation, self-efficacy, utility value, and test anxiety. The nonlinear SEM reliability coefficients of the five constructs …

Disturbance Triggers Non-Linear Microbe–Environment Feedbacks, Aditi Sengupta, Sarah J. Fansler, Rosalie K. Chu, Robert E. Danczak, Vanessa A. Garayburu-Caruso, Lupita Renteria, Hyun-Seob Song, Jason Toyoda, Jacqueline Wells, James C. Stegen

Department of Biological Systems Engineering: Papers and Publications

Conceptual frameworks linking microbial community membership, properties, and processes with the environment and emergent function have been proposed but remain untested. Here we refine and test a recent conceptual framework using hyporheic zone sediments exposed to wetting–drying transitions. Our refined framework includes relationships between cumulative properties of a microbial community (e.g., microbial membership, community assembly properties, and biogeochemical rates), environmental features (e.g., organic matter thermodynamics), and emergent ecosystem function. Our primary aim was to evaluate the hypothesized relationships that comprise the conceptual framework and contrast outcomes from the whole and putatively active bacterial and archaeal communities. Throughout the system we …

Making Space For Social And Emotional Learning In Science Education, Erin Ingram, Kristie Reddick, Jessica M. Honaker, Gwen A. Pearson

Department of Biological Systems Engineering: Papers and Publications

Social-emotional learning (SEL) is known to improve student outcomes but is rarely combined with STEM. In this paper we present an action research study to examine the impact of a STEM + SEL curriculum intervention to address a real-world school conflict. One hundred sixth–eighth graders and four teachers participated in an in-person facilitation of a SEL Arthropod curriculum, DIFFERENT. After the intervention, students completed open-ended couplet statements about arthropod behavior, tarantulas, and humans designed to measure sentiment change. Answers were manually coded using inductive coding on a scale of negative (1) to positive (5). Statement sentiments significantly shifted from negative …

Probabilistic Seismic Vulnerability Assessment Of Freestanding Historic Monuments, Marie E. Wagner

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

Seismic events can cause significant damage to structures, especially to freestanding structures which are not fixed to the ground and are free to rock independently. This thesis will study the response of freestanding statues and monuments to ground motions and develop probabilistic models for overturning, in order to assist in retrofitting and repair efforts. To do this, single and dual block system models were created with a variety of sizes, aspect ratios, and asymmetries, then subjected to several historic ground motions to determine whether they overturn using three-dimensional distinct element analysis as a result of rocking, sliding or twisting in …

Biofiltration Application At Ethanol Plants: Analysis Of Aqueous Streams And Treatment Of Vocs, Katie Mowat

Department of Environmental Engineering: Theses and Student Research

The United States used 14.5 billion gallons of the biofuel ethanol in 2019 produced primarily (82%) in dry-mill corn ethanol plants. These plants produce volatile organic compounds (VOCs) — some of which are hazardous air pollutants (HAPs) — during production. Traditional treatment methods for gaseous emissions use a large quantity of water or natural gas. Thus, a bio-trickling filter (BTF) is considered an innovative alternative treatment method. A lab-scale BTF was used in this study to look at the effect of ethanol concentration and temperature on the treatment of a HAPs mixture. Gaseous and aqueous testing were performed on the …

Prioritization Of Research On Bridge Railings For Use On Timber Deck Bridges And Development Of Two Glulam Bridge Railing Systems, Jared Duren

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

In the past, many timber bridge railings, bridge railings for use on timber deck bridges, and approach guardrail transition systems to accompany these railings, have been developed to meet different impact safety criteria. Through an extensive literature review, the design details of these systems were identified and organized. A survey was then developed and distributed to multiple government agencies and timber industry members to identify their desire for these bridge railing and approach guardrail transition systems to be developed to meet current American Association of State Highway and Transportation Officials (AASHTO) Manual for Assessing Safety Hardware (MASH) impact safety criteria. …

Establishing Safe Operating Speeds For Autonomous Vehicles: A Case Study From The Automated Skyway Express In Jacksonville, Florida, Andrew Loken

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

Autonomous vehicles (AVs) differ significantly from traditional passenger vehicles in both their behavior and physical characteristics. As such, the validity of the guidance provided in the Manual for Assessing Safety Hardware, Second Edition (MASH 2016) is questionable in AV applications. Impact conditions specified in MASH 2016 are inextricably linked to the traditional vehicles underlying the estimates. For AV applications, conditions must be estimated from the ground up, stepping outside the guidance of MASH 2016. Herein, a method for evaluating existing infrastructure to support AV traffic is proposed. The method integrates traditional structural analyses with unconventional methods of estimating impact conditions. …