Engineering Commons^™

Effects Of Nutrient Level And Growth Rate On Mutation And Conjugation Processes That Confer Antibiotic Resistance To E. Coli, Mohammadreza Shafieifini

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

Antibiotic resistance genes (ARGs) may enter surface water with the discharge of treated wastewater. Conjugation is a main mechanism for the horizontal gene transfer of ARGs from wastewater microbiome to the microbiome indigenous to surface water. However, little is known about how environmental factors affect the conjugation process of ARGs.

In this thesis, an extensive research related to spreading antibiotic resistance genes in the environment is reported. The project investigated how environmental parameters may affect the rate of dissemination of ARGs and in what extent the resistance level of the population is changed after mutation and conjugation event. The chemostat …

Microbial Transport As Affected By Residue Cover And Manure Application Rate, Lisa M. Durso, John E. Gilley, Dave B. Marx, Chance A. Thayer, Brian L. Woodbury

Biological Systems Engineering: Papers and Publications

Manure is applied to cropland areas with varying surface cover to meet single- or multiple-year crop nutrient requirements. The objectives of this field study were to (1) examine microbial transport following land application of manure to sites with and without wheat residue, (2) compare microbial loads following land application to meet the 0, 1, 2, 4, and 8-year P-based requirements for corn, and (3) evaluate the effects of rainfall simulation run on microbial transport. Manure was added and incorporated by disking plots that were 0.75 m wide by 2.0 m long. Three 30 min simulated rainfall events, separated by 24 …

High‑Throughput Analysis Of Leaf Physiological And Chemical Traits With Vis–Nir–Swir Spectroscopy: A Case Study With A Maize Diversity Panel, Yufeng Ge, Abbas Atefi, Huichun Zhang, Chenyong Miao, Raghuprakash Kastoori Ramamurthy, Brandi Sigmon, Jinliang Yang, James C. Schnable

Biological Systems Engineering: Papers and Publications

Hyperspectral reflectance data in the visible, near infrared and shortwave infrared range (VIS–NIR– SWIR, 400–2500 nm) are commonly used to nondestructively measure plant leaf properties. We investigated the usefulness of VIS–NIR–SWIR as a high-throughput tool to measure six leaf properties of maize plants including chlorophyll content (CHL), leaf water content (LWC), specific leaf area (SLA), nitrogen (N), phosphorus (P), and potassium (K). This assessment was performed using the lines of the maize diversity panel. Data were collected from plants grown in greenhouse condition, as well as in the field under two nitrogen application regimes. Leaf-level hyperspectral data were collected with …

Biomethane Production From Distillery Wastewater, Zachary Christman

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Distillery wastewater treatment is a great ecological problem, for example, India produces 2.7 billion liters of alcohol that results in 40 billion liters of wastewater. However, this material can be seen as a resource since 11 million cubic meters of biogas at 60% methane could be produced in addition to cleaning the water. The distillery has two options of what to do with the biogas. The first is to use the biogas to fuel the distillery making the production plant more energy efficient and removing some of the need to buy natural gas. The other is to upgrade the biogas …

A Spatially Enhanced Data‐Driven Multimodel To Improve Semiseasonal Groundwater Forecasts In The High Plains Aquifer, Usa, A. Amaranto, Francisco Munoz-Arriola, D. P. Solomatine, G. Corzo

Biological Systems Engineering: Papers and Publications

The aim of this paper is to improve semiseasonal forecast of groundwater availability in response to climate variables, surface water availability, groundwater level variations, and human water management using a two‐step data‐driven modeling approach. First, we implement an ensemble of artificial neural networks (ANNs) for the 300 wells across the High Plains aquifer (USA). The modeling framework includes a method to choose the most relevant input variables and time lags; an assessment of the effect of exogenous variables on the predictive capabilities of models; and the estimation of the forecast skill based on the Nash‐Sutcliffe efficiency (NSE) index, the normalized …

Environmental And Occupational Impacts From U.S. Beef Slaughtering Are Of Same Magnitude Of Beef Foodborne Illnesses On Human Health, Shaobin Li, Jeyamkondan Subbiah, Bruce Dvorak

Biological Systems Engineering: Papers and Publications

Foodborne pathogens and occupational hazards are two primary safety concerns for U.S. beef slaughterhouses. The anthropogenic environmental impacts due to intensive resource use and pollution also exert threats to human health. Quantifying human health impacts from various sources remain a grand sustainability challenge for U.S. beef industry. We develop a framework to systematically estimate and compare human health impacts associated with U.S. beef foodborne illnesses from major pathogens and environmental impacts and occupational hazards from U.S. beef slaughtering on a common metric, disability-adjusted life year (DALY). Foodborne illnesses and occupational hazards are estimated by synthesizing published data and methodologies while …

Theoretical Model For Shields Diagram And Its Application, Jichao Jiang

Department of Environmental Engineering: Theses and Student Research

The transition from the condition of “no motion” to initial sediment moment, defined as sediment initiation, has been related to practical engineering (channel degradation, stable channel design), oceanographic (dredging, pipelines, cables), sedimentologic (sediment mobility, transport rates), geologic (the hydraulic interpretation of paleoenvironments), geochemical (pollutant transport), and gained considerable interest since nineteenth century.

Shields diagram for sediment initiation in terms of critical shear stress is a classic problem in sediment transport, but it is still an empirical law without a simple and practical theory despite extensive research since the 1930s. Hence, this research presents a simple theoretical model for critical shear …

Biofiltration Of Volatile Organic Compounds Emitted At Ethanol Plants, Christopher Arthur Duerschner

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

Ethanol manufacturing is an important and growing sector in the biofuels marketplace. At ethanol plants, the control of volatile organic compound containing emissions from fermentation tanks and distillers dried grains with solubles driers is accomplished through the use of air scrubbers and regenerative thermal oxidizers. The operation of these control units imposes substantial operating costs for the ethanol plant. Biotrickling filters have the ability to replace scrubbers and regenerative thermal oxidizers resulting in significant economic and environmental benefits. Two biotrickling filters were operated in parallel under acetaldehyde loadings ranging from 4 to 136 gm^-3hr^-1. To examine …

Unl-Cc Outdoor Education Center Master Plan, Marie Wagner

Honors Theses

The following report contains the work done by the group Griswold Engineering in completion of the Senior Design requirements for Civil Engineering and the Honors Requirements of the Project Manager. As the project manager, my job was to organize the project as a whole and to work alongside the Structural Engineer on the project. One of the main problems to overcome was the division of labor amongst the group. The project was originally conceived as a group project with one project manager and five other students to serve as the project engineers in each subdiscipline. Since this group only had …

Civil Engineering Design Of Cornhusker Council's Outdoor Education Center, Kelly Weiler

Honors Theses

A team of geotechnical, structural, hydraulic, environmental, and transportation experts collaborated to provide engineering solutions to the Cornhusker Council in an effort to solve the current problems facing their Outdoor Education Center. This results of this project provided the structural design of three bridges on the property, transportation plans for two parking lots and roadway design, geotechnical recommendations for soil testing and erosion prevention, and an environmental and hydraulic analysis of the property. A major challenge in the design of this project is the consideration of the dangers and regulations that accompany the floodway and floodplain regions on site. Various …

Wheat Strip Effects On Microbial Transport Following Variable Applications Of Beef Cattle Manure, Lisa M. Durso, John E. Gilley, David B. Marx, Chance A. Thayer, Bryan L. Woodbury

Biological Systems Engineering: Papers and Publications

Vegetative filter strips (VFS) consisting of perennial vegetation have been successfully used to reduce the transport of contaminants in runoff from land application areas. The effectiveness of a winter wheat strip, which may be more acceptable to producers, in reducing microbial transport was examined in this study. A 1.4 m wheat strip was used to allow direct comparison with experimental results obtained in previous studies. Beef cattle manure was applied to 0.75 m wide by 4.0 m long plots established on an Aksarben silty clay loam located in southeast Nebraska. Manure was added at rates required to meet the 0- …

Simulation Of Antimicrobial Resistance Gene Fate In Narrow Grass Hedges, Marzieh Khedmati

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

Vegetative Filter Strips (VFS) are used for controlling the volume of runoff and decreasing the contaminants in runoff before entering the water bodies. Many studies investigated the role of VFS in sediment and nutrient removal, but little is known about their efficiency in the removal of emerging contaminants such as antimicrobial resistance genes (ARGs). VFSMOD was used to simulate the efficiency of VFS in this regard. The objectives of this study were to calibrate the VFSMOD with some experimental data and asses the efficiency of the model in simulating the filter behavior in removing ARGs. The tests were conducted in …

Evaluation Of Selected Watershed Characteristics To Identify Best Management Practices To Reduce Nebraskan Nitrate Loads From Nebraska To The Mississippi/Atchafalaya River Basin, Aaron R. Mittelstet, Troy E. Gilmore, Tiffany Messer, Daran Rudnick, Thomas Heatherly

Biological Systems Engineering: Papers and Publications

Nebraskan streams contribute excess nitrogen to the Mississippi/Atchafalaya River Basin and Gulf of Mexico, which results in major water-quality impairments. Reducing the amount of nitrogen (N) exported in these streams requires the use of best management practices (BMPs) within the landscape. However, proper BMP utilization has rarely been statistically connected to potential controls of N export within watersheds, particularly precipitation and soil characteristics. In this study, 19 watershed variables were evaluated in five categories (hydrological, physiographic, point sources, land use, and soil properties) to determine the characteristics that influenced variable nitrate nitrogen (NO₃-N) concentrations in 17 Nebraska watersheds …

Quantifying And Correcting For Clay Content Effects On Soil Water Measurement By Reflectometers, Jasreman Singh, Tsz Him Lo, Daran Rudnick, Suat Irmak, Humberto Blanco-Canqui

Biological Systems Engineering: Papers and Publications

The presence of clay particles increases the specific surface area of a soil and can affect the calibration of electromagnetic soil water sensors including reflectometers. To quantify and correct for this effect in two relatively new reflectometers, three TDR315 and three CS655 sensors were installed in each of five soils with clay content ranging from 5 to 49%. As the soils were dried in a temperature controlled room, sensor reported soil volumetric water content (θ_v) according to the factory calibration was compared against reference θ_v determined by weighing the soils. Sensor reported θ_v was similar to …

Aesthetics, Ethics, And Lose-Lose Dilemmas In The Anthropocen, Adam Liska

Biological Systems Engineering: Papers and Publications

Anthropogenic climate change will cause violence to increase globally, and nonlinear increases in sea level could cause a major escalation in global conflict. After 2100, a 22-meter sea-level rise is estimated here to dislocate two billion people from coastal areas. These impending civilization-changing events require us to again reevaluate our prevalent aesthetic preferences for luxury that produce a significant fraction of anthropogenic greenhouse gas emissions. Due to industrial inertia, a central dilemma discussed here is the contradictions between the goals and impacts of aesthetics and ethics. Either we lose our own well-being (a loss of high-emission aesthetics) for the benefit …

Biomaterial Substrate Modifications That Influence Cell-Material Interactions To Prime Cellular Responses To Nonviral Gene Delivery, Amy Mantz, Angela K. Pannier

Biological Systems Engineering: Papers and Publications

Gene delivery is the transfer of exogenous genetic material into somatic cells to modify their gene expression, with applications including tissue engineering, regenerative medicine, sensors and diagnostics, and gene therapy. Viral vectors are considered the most effective system to deliver nucleic acids, yet safety concerns and many other disadvantages have resulted in investigations into an alternative option, i.e. nonviral gene delivery. Chemical nonviral gene delivery is typically accomplished by electrostatically complexing cationic lipids or polymers with negatively charged nucleic acids. Unfortunately, nonviral gene delivery suffers from low efficiency due to barriers that impede transfection success, including intracellular processes such as …

Deficit Irrigation Management Of Maize In The High Plains Aquifer Region: A Review, Daran Rudnick, Sibel Irmak, C. West, J.L. Chavez, I. Kisekka, T.H. Marek, J.P. Schneekloth, D. Mitchell Mccallister, V. Sharma, K. Djaman, J. Aguilar, M.E. Schipanski, D.H. Rogers, A. Schlegel

Biological Systems Engineering: Papers and Publications

Irrigated agriculture is a major economic contributor of the High Plains Region and it primarily relies on the High Plains Aquifer as a source of water. Over time, areas of the High Plains Aquifer have experienced drawdowns limiting its ability to supply sufficient water to sustain fully irrigated crop production. This among other reasons, including variable climatic factors and differences in state water policy, has resulted in some areas adopting and practicing deficit irrigation management. Considerable research has been conducted across the High Plains Aquifer region to identify locally appropriate deficit irrigation strategies. This review summarizes and discusses research conducted …

Time-Domain And Frequency-Domain Reflectometry Type Soil Moisture Sensor Performance And Soil Temperature Effects In Fine- And Coarse-Textured Soils, Y. Zhu, S. Irmak, A. J. Jhala, M. C. Vuran, A. Diotto

Biological Systems Engineering: Papers and Publications

The performances of six time-domain reflectometry (TDR) and frequency-domain reflectometry (FDR) type soil moisture sensors were investigated for measuring volumetric soil-water content (θ_v) in two different soil types. Soil-specific calibration equations were developed for each sensor using calibrated neutron probe-measured θ_v. Sensors were also investigated for their performance response in measuring θ_v to changes in soil temperature. The performance of all sensors was significantly different (P<0.05) than the neutron probe-measured θ_v, with the same sensor also exhibiting variation between soils. In the silt loam soil, the 5TE sensor had the lowest root mean squared error (RMSE) of 0.041 …

System For Optimizing Fed-Batch Hydrolysis Of Biomass, Chao Tai, Deepak R. Keshwani

Biological Systems Engineering: Papers and Publications

Provided herein is a system for optimizing the fed - batch hydrolysis of biomass.

Actual Evapotranspiration And Crop Coefficients Of Irrigated Lowland Rice (Oryza Sativa L.) Under Semiarid Climate, Koffi Djaman, Daran R. Rudnick, Yonnelle D. Moukoumbi, Abdoulaye Sow, Suat Irmak

Biological Systems Engineering: Papers and Publications

Lowland irrigated rice is the predominant crop produced in the Senegal River Valley characterized by very low annual rainfall, high temperatures, and low relative humidity. The Senegal River is shared by Senegal, Mali, Mauritania, and Guinea, and serves as the main source of irrigation water for the adopted double rice cropping system. Developing appropriate resource management strategies might be the key factor for the sustainability of rice production in the region. This study aims to estimate rice seasonal evapotranspiration (ETa), irrigation water requirement, and to develop rice growth stage specific crop coefficients (Kc) to improve rice water productivity. Field experiments …

Nebraska Water Center Annual Report 2017-2018, The Nebraska Water Center

Literature from The Nebraska Water Center

Contents

Introduction: Foreword • Director’s Letter by Chittaranjan Ray • Nebraska Water Center Overview and Timeline • Nebraska’s Top 10 Water Challenges

Research: Water Sciences Laboratory Overview • Nebraska Vadose Zone Program • Novel Nitrate Leaching Reduction • Ogallala Water Coordinated Agriculture Project (OWCAP) • Nebraska Water Productivity Report • USDA-NIFA Water End-User Grant • U.S. Geological Survey 104b Projects

Extension & Outreach: Bazile Groundwater Management Area • Platte River Basin Ecosystem Symposium • Testing Ag Performance Solutions (TAPS) • 2018 National Institutes for Water Resources Regional Symposium • Water Quality + Citizen Science • Nebraska Water and Natural Resources …

Free Polyethylenimine Enhances Substrate-Mediated Gene Delivery On Titanium Substrates Modified With Rgd-Functionalized Poly(Acrylic Acid) Brushes, Amy Mantz, Alice Rosenthal, Eric Farris, Tyler Kozisek, Eva Bittrich, Saghar Nazari, Eva Schubert, Mathias Schubert, Manfred Stamm, Petra Uhlmann, Angela K. Pannier

Biological Systems Engineering: Papers and Publications

Substrate mediated gene delivery (SMD) is a method of immobilizing DNA complexes to a substrate via covalent attachment or nonspecific adsorption, which allows for increased transgene expression with less DNA compared to traditional bolus delivery. It may also increase cells receptivity to transfection via cell-material interactions. Substrate modifications with poly(acrylic) acid (PAA) brushes may improve SMD by enhancing substrate interactions with DNA complexes via tailored surface chemistry and increasing cellular adhesion via moieties covalently bound to the brushes. Previously, we described a simple method to graft PAA brushes to Ti and further demonstrated conjugation of cell adhesion peptides (i.e., RGD) …

Genetic Diversity And Population Structure Of A Camelina Sativa Spring Panel, Zinan Luo, Jordan Brock, John M. Dyer, Toni Kutchan, Daniel P. Schachtman, Megan Augustin, Yufeng Ge, Noah Fahlgren, Hussein Abdel-Haleem

Biological Systems Engineering: Papers and Publications

There is a need to explore renewable alternatives (e.g., biofuels) that can produce energy sources to help reduce the reliance on fossil oils. In addition, the consumption of fossil oils adversely affects the environment and human health via the generation of waste water, greenhouse gases, and waste solids. Camelina sativa, originated from southeastern Europe and southwestern Asia, is being re-embraced as an industrial oilseed crop due to its high seed oil content (36–47%) and high unsaturated fatty acid composition (>90%), which are suitable for jet fuel, biodiesel, high-value lubricants and animal feed. C. sativa’s agronomic advantages include …

Narrow Grass Hedge Effects On Microbial Transport Following Variable Applications Of Beef Cattle Manure, Lisa M. Durso, John E. Gilley, Dave B. Marx, Brian L. Woodbury

Biological Systems Engineering: Papers and Publications

The effectiveness of a 1.4 m wide grass hedge in reducing microbial transport following manure application was examined in this study. Beef cattle manure was applied to 0.75 m wide by 4.0 m long plots established on an Aksarben silty clay loam located in southeast Nebraska. Manure was added at rates required to meet none or the 1-, 2-, or 4-year nitrogen requirements for corn. The transport of phages, total coliforms, E. coli, and enterococci was measured for three 30 min simulated rainfall events, which were separated by approximately 24 h intervals. The narrow grass hedge reduced total counts of …

Rapeseed Seedling Stand Counting And Seeding Performance Evaluation At Two Early Growth Stages Based On Unmanned Aerial Vehicle Imagery, Biquan Zhao, Jian Zhang, Chenghai Yang, Guangsheng Zhou, Youchun Ding, Yeyin Shi, Dongyan Zhang, Jing Xie, Qingxi Liao

Biological Systems Engineering: Papers and Publications

The development of unmanned aerial vehicles (UAVs) and image processing algorithms for field-based phenotyping offers a non-invasive and effective technology to obtain plant growth traits such as canopy cover and plant height in fields. Crop seedling stand count in early growth stages is important not only for determining plant emergence, but also for planning other related agronomic practices. The main objective of this research was to develop practical and rapid remote sensing methods for early growth stage stand counting to evaluate mechanically seeded rapeseed (Brassica napus L.) seedlings. Rapeseed was seeded in a field by three different seeding devices. A …

Early Prediction Of Soybean Traits Through Color And Texture Features Of Canopy Rgb Imagery, Wenan Yuan, Nuwan Kumara Wijewardane, Shawn Jenkins, Geng Bai, Yufeng Ge, George L. Graef

Biological Systems Engineering: Papers and Publications

Global crop production is facing the challenge of a high projected demand, while the yields of major crops are not increasing at sufficient speeds. Crop breeding is an important way to boost crop productivity, however its improvement rate is partially hindered by the long crop generation cycles. If end-season crop traits such as yield can be predicted through early-season phenotypic measurements, crop selection can potentially be made before a full crop generation cycle finishes. This study explored the possibility of predicting soybean end-season traits through the color and texture features of early-season canopy images. Six thousand three hundred and eighty-three …

Optimization Of Process Parameters And Fermentation Strategy For Xylanase Production In A Stirred Tank Reactor Using A Mutant Aspergillus Nidulans Strain, Asmaa Abdella, Fernando Segato, Mark R. Wilkins

Biological Systems Engineering: Papers and Publications

The present work studied the optimization of aeration rate, agitation rate and oxygen transfer and the use of various batch fermentation strategies for xylanase production from a recombinant Aspergillus nidulans strain in a 3 L stirred tank reactor. Maximum xylanase production of 1250 U/mL with productivity of 313 U/mL/day was obtained under an aeration rate of 2 vvm and an agitation rate of 400 rpm using batch fermentation. The optimum volumetric oxygen transfer coefficient (kLa) for efficient xylanase production was found to be 38.6 h1. Fed batch mode and repeated batch fermentation was also performed with kLa was 38.6 h1. …

Design Of Plant Protection Uav Variable Spray System Based On Neural Networks, Sheng Wen, Quanyong Zhang, Xuanchun Yin, Yubin Lan, Jiantao Zhang, Yufeng Ge

Biological Systems Engineering: Papers and Publications

Recently, unmanned aerial vehicles (UAVs) have rapidly emerged as a new technology in the fields of plant protection and pest control in China. Based on existing variable spray research, a plant protection UAV variable spray system integrating neural network based decision making is designed. Using the existing data on plant protection UAV operations, combined with artificial neural network (ANN) technology, an error back propagation (BP) neural network model between the factors affecting droplet deposition is trained. The factors affecting droplet deposition include ambient temperature, ambient humidity, wind speed, flight speed, flight altitude, propeller pitch, nozzles pitch and prescription value. Subsequently, …

Factors Related To Intra-Tendinous Morphology Of Achilles Tendon In Runners, Kai-Yu Ho, Ari Baquet, Yu-Jen Chang, Lung-Chang Chien, Michelle Harty, Gregory Bashford, Kornelia Kulig

Biological Systems Engineering: Papers and Publications

The purpose of this study was to determine and explore factors (age, sex, anthropometry, running and injury/pain history, tendon gross morphology, neovascularization, ankle range of motion, and ankle plantarflexor muscle endurance) related to intra-tendinous morphological alterations of the Achilles tendon in runners. An intra-tendinous morphological change was defined as collagen fiber disorganization detected by a low peak spatial frequency radius (PSFR) obtained from spatial frequency analysis (SFA) techniques in sonography. Ninety-one runners (53 males and 38 females; 37.9 ± 11.6 years) with 8.8 ± 7.3 years of running experience participated. Height, weight, and waist and hip circumferences were recorded. Participants …

Grain Yield, Crop And Basal Evapotranspiration, Production Functions And Water Productivity Response Of Drought-Tolerant And Non-Drought-Tolerant Maize Hybrids Under Different Irrigation Levels, And Population Densities: Part I. In Western Nebraska's Semi-Arid Environments, Ali T. Mohammed, Suat Irmak, William Kranz, Simon Van Donk, C. Dean Yonts

Biological Systems Engineering: Papers and Publications

Grain yield, crop evapotranspiration (ETc), basal evapotranspiration (ETb), ETc-yield production functions (ETYPF), and crop water use efficiency (CWUE) response of three drought-tolerant (DT) and one non-drought-tolerant (NDT) maize (Zea mays L.) hybrids to two plant population densities (PPDs) [84,000 plants ha-1 (high PPD) and 59,300 plants ha-1 (low PPD)] and three irrigation levels were researched at two semi-arid locations: North Platte (WCREC) and Scottsbluff (MAL), Nebraska, in 2010, 2011, and 2012. The irrigation levels were fully irrigated (FIT), early cutoff (ECOT), and rainfed (RFT). Precipitation in 2010 was above average, 2011 was a normal year, and 2012 was one of …