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Full-Text Articles in Engineering

Effects Of Nutrient Level And Growth Rate On Mutation And Conjugation Processes That Confer Antibiotic Resistance To E. Coli, Mohammadreza Shafieifini Aug 2019

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

Civil Engineering Theses, Dissertations, 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 Jul 2019

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 ...


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 Jun 2019

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 ...


Biomethane Production From Distillery Wastewater, Zachary Christman Jun 2019

Biomethane Production From Distillery Wastewater, Zachary Christman

Theses, Dissertations, and Student Research in Agronomy and Horticulture

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 ...


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 Jun 2019

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 ...


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 Jun 2019

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 ...


Theoretical Model For Shields Diagram And Its Application, Jichao Jiang May 2019

Theoretical Model For Shields Diagram And Its Application, Jichao Jiang

Environmental Engineering Theses and Graduate 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 May 2019

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

Civil Engineering Theses, Dissertations, 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 the ...


Civil Engineering Design Of Cornhusker Council's Outdoor Education Center, Kelly Weiler Apr 2019

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

Honors Theses, University of Nebraska-Lincoln

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 ...


Simulation Of Antimicrobial Resistance Gene Fate In Narrow Grass Hedges, Marzieh Khedmati Apr 2019

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

Civil Engineering Theses, Dissertations, 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 ...


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 Apr 2019

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 ...


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 Feb 2019

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 ...


Biomaterial Substrate Modifications That Influence Cell-Material Interactions To Prime Cellular Responses To Nonviral Gene Delivery, Amy Mantz, Angela K. Pannier Feb 2019

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 ...


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 Jan 2019

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 ...


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 Jan 2019

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 ...


Nucleic Acid Delivery To Mesenchymal Stem Cells: A Review Of Nonviral Methods And Applications, Andrew Hamann, Albert Nguyen, Angela K. Pannier Jan 2019

Nucleic Acid Delivery To Mesenchymal Stem Cells: A Review Of Nonviral Methods And Applications, Andrew Hamann, Albert Nguyen, Angela K. Pannier

Biological Systems Engineering: Papers and Publications

Background: Mesenchymal stem cells (MSCs) are multipotent stem cells that can be isolated and expanded from many tissues, and are being investigated for use in cell therapies. Though MSC therapies have demonstrated some success, none have been FDA approved for clinical use. MSCs lose stemness ex vivo, decreasing therapeutic potential, and face additional barriers in vivo, decreasing therapeutic efficacy. Culture optimization and genetic modification of MSCs can overcome these barriers. Viral transduction is efficient, but limited by safety concerns related to mutagenicity of integrating viral vectors and potential immunogenicity of viral antigens. Nonviral delivery methods are safer, though limited by ...


Design Of Plant Protection Uav Variable Spray System Based On Neural Networks, Sheng Wen, Quanyong Zhang, Xuanchun Yin, Yubin Lan, Jiantao Zhang, Yufeng Ge Jan 2019

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 ...


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 Jan 2019

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 ...


Water Effects On Optical Canopy Sensing For Late-Season Site-Specific Nitrogen Management Of Maize, Tsz Him Lo, Daran Rudnick, Brian Krienke, D. M. Heeren, Yufeng Ge, Tim M. Shaver Jan 2019

Water Effects On Optical Canopy Sensing For Late-Season Site-Specific Nitrogen Management Of Maize, Tsz Him Lo, Daran Rudnick, Brian Krienke, D. M. Heeren, Yufeng Ge, Tim M. Shaver

Biological Systems Engineering: Papers and Publications

The interpretation of optical canopy sensor readings for determining optimal rates of late-season site-specific nitrogen application to corn (Zea mays L.) can be complicated by spatially variable water sufficiency, which can also affect canopy size and/or pigmentation. In 2017 and 2018, corn following corn and corn following soybeans were subjected to irrigation×nitrogen fertilizer treatments in west central Nebraska, USA, to induce variable water sufficiency and variable nitrogen sufficiency. The vegetation index-sensor combinations investigated were the normalized difference vegetation index (NDVI), the normalized difference red edge index (NDRE), and the reflectance ratio of near infrared minus red edge over ...


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 Jan 2019

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 ...


The Development Of The Infews-Er: A Virtual Resource Center For Transdisciplinary Graduate Student Training At The Nexus Of Food, Energy, And Water, Luis F. Rodriguez, Anna-Maria Marshall, Dan Cotton, Richard K. Koelsch, Jacek Koziel, Deanne Meyer, Dan Steward, Jill Heemstra, Anand Padmanabahn, John Classen, Nathan J. Meyer, Benjamin L. Ruddell, Sean M. Ryan, Ximing Cai, Emad Habib, Peter D. Saundry Jan 2019

The Development Of The Infews-Er: A Virtual Resource Center For Transdisciplinary Graduate Student Training At The Nexus Of Food, Energy, And Water, Luis F. Rodriguez, Anna-Maria Marshall, Dan Cotton, Richard K. Koelsch, Jacek Koziel, Deanne Meyer, Dan Steward, Jill Heemstra, Anand Padmanabahn, John Classen, Nathan J. Meyer, Benjamin L. Ruddell, Sean M. Ryan, Ximing Cai, Emad Habib, Peter D. Saundry

Biological Systems Engineering: Papers and Publications

Problems at the nexus of Food, Energy and Water Systems (FEWS) are among the most complex challenges we face. Spanning simple to complex temporal, geographic, social, and political framings, the questions raised at this nexus require multidisciplinary if not transdisciplinary approaches. Answers to these questions must draw from engineering, the physical and biological sciences, and the social sciences. Practical solutions depend upon a wide community of stakeholders, including industry, policymakers, and the general public. Yet there are many obstacles to working in a transdisciplinary environment: unfamiliar concepts, specialized terminology, and countless “blind” spots. Graduate education occurs in disciplinary ‘silos’, often ...