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University of Nebraska - Lincoln

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2013

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Articles 1 - 30 of 32

Full-Text Articles in Environmental Engineering

Narrow Grass Hedge Effects On The Transport Of Antimicrobials And Antimicrobial Resistance Genes Following Land Application Of Swine Slurry, Bhavneet Soni Dec 2013

Narrow Grass Hedge Effects On The Transport Of Antimicrobials And Antimicrobial Resistance Genes Following Land Application Of Swine Slurry, Bhavneet Soni

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

The objective of this study was to determine the effects of manure amendment and narrow grass hedges on the fate and transport of antimicrobials and ARGs in runoff and in soil following the land application of swine manure slurry. Swine manure slurry was land applied to 0.75m wide by 4.0m long plots established on an Aksarben silty clay loam soil located in southeast Nebraska. The treatment factor manure amendment consisted of two levels: no manure application and manure application to meet the 3 year nitrogen (N) requirements for corn. The treatment factor of grass hedge was established for half of …


Drainage Structure Datasets And Effects On Lidar-Derived Surface Flow Modeling, Ruopu Li, Zhenghong Tang, Xu Li, Jessie Winter Dec 2013

Drainage Structure Datasets And Effects On Lidar-Derived Surface Flow Modeling, Ruopu Li, Zhenghong Tang, Xu Li, Jessie Winter

School of Natural Resources: Faculty Publications

With extraordinary resolution and accuracy, Light Detection and Ranging (LiDAR)-derived digital elevation models (DEMs) have been increasingly used for watershed analyses and modeling by hydrologists, planners and engineers. Such high-accuracy DEMs have demonstrated their effectiveness in delineating watershed and drainage patterns at fine scales in low-relief terrains. However, these high-resolution datasets are usually only available as topographic DEMs rather than hydrologic DEMs, presenting greater land roughness that can affect natural flow accumulation. Specifically, locations of drainage structures such as road culverts and bridges were simulated as barriers to the passage of drainage. This paper proposed a geospatial method for producing …


Development Of A Field Test For Total Suspended Solids Analysis, Jessica Branigan Dec 2013

Development Of A Field Test For Total Suspended Solids Analysis, Jessica Branigan

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

Total suspended solids (TSS) are all particles in water that will not pass through a glass fiber filter with a pore size less than 2 μm, including sediments, algae, nutrients, and metals. TSS is an important water quality parameter because of its adverse effects on aquatic species and wildlife. The EPA has proposed a regulation for turbidity, a related water quality parameter, which has been stayed pending further testing. TSS is regulated through the EPA via the NPDES in many states. Since there are no accepted field tests for TSS, projects with TSS regulations must send samples to a laboratory …


Elementary Implantable Force Sensor For Smart Orthopaedic Implants, Rebecca A. Wachs, David Ellstein, John Drazan, Colleen P. Healey, Richard L. Uhl, Kenneth A. Connor, Eric H. Ledet Dec 2013

Elementary Implantable Force Sensor For Smart Orthopaedic Implants, Rebecca A. Wachs, David Ellstein, John Drazan, Colleen P. Healey, Richard L. Uhl, Kenneth A. Connor, Eric H. Ledet

Department of Biological Systems Engineering: Papers and Publications

Implementing implantable sensors which are robust enough to maintain long term functionality inside the body remains a significant challenge. The ideal implantable sensing system is one which is simple and robust; free from batteries, telemetry, and complex electronics. We have developed an elementary implantable sensor for orthopaedic smart implants. The sensor requires no telemetry and no batteries to communicate wirelessly. It has no on-board signal conditioning electronics. The sensor itself has no electrical connections and thus does not require a hermetic package. The sensor is an elementary L-C resonator which can function as a simple force transducer by using a …


Improving The Sweeping Efficiency Of Permanganate Into Low Permeable Zones To Treat Tce: Experimental Results And Model Development, Chanat Chokejaroenrat, Negin Kananizadeh, Chainarong Sakulthaew, Steve D. Comfort, Yusong Li Oct 2013

Improving The Sweeping Efficiency Of Permanganate Into Low Permeable Zones To Treat Tce: Experimental Results And Model Development, Chanat Chokejaroenrat, Negin Kananizadeh, Chainarong Sakulthaew, Steve D. Comfort, Yusong Li

Nebraska Water Center: Faculty Publications

The residual buildup and treatment of dissolved contaminants in low permeable zones (LPZs) is a particularly challenging issue for injection-based remedial treatments. Our objective was to improve the sweeping efficiency of permanganate into LPZs to treat dissolved-phase TCE. This was accomplished by conducting transport experiments that quantified the ability of xanthan-MnO4 solutions to penetrate and cover (i.e., sweep) an LPZ that was surrounded by transmissive sands. By incorporating the non-Newtonian fluid xanthan with MnO4, penetration of MnO4 into the LPZ improved dramatically and sweeping efficiency reached 100% in fewer pore volumes. To quantify …


Passive Stormwater Samplers For Sampling Highway Runoff From Bmps: Feasibility Studies, Mitchell R. Klein Aug 2013

Passive Stormwater Samplers For Sampling Highway Runoff From Bmps: Feasibility Studies, Mitchell R. Klein

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

Pollution from highway stormwater runoff has been an increasing area of concern within the environmental field. To respond to the need for reduced contamination within runoff many Best Management Practices (BMPs) have been implemented. One difficult aspect of BMPs is monitoring their effectiveness along with determining effluent concentrations. The current methods for stormwater sampling include sending technicians or installing an auto-sampler to collect either grab or composite samples. These methods become costly, cumbersome and infeasible due to the potentially large amount of BMPs across a region and the irregularity and difficulty of predicting storms. Passive samplers have proven themselves as …


Laboratory Evaluation Of A Turn Compensation Control System For A Ground Sprayer, W. M. Porter, J. A. Rascon, Yeyin Shi, Randal K. Taylor, Paul A. Weckler Jun 2013

Laboratory Evaluation Of A Turn Compensation Control System For A Ground Sprayer, W. M. Porter, J. A. Rascon, Yeyin Shi, Randal K. Taylor, Paul A. Weckler

Department of Biological Systems Engineering: Papers and Publications

The ability to compensate sprayer nozzle flow across a horizontal boom has the potential to mitigate the problem of inaccurate chemical application rate due to lateral speed differences when sprayers are turning. A laboratory testing platform and procedure were developed and tested with a commercial turn compensation control system for a ground sprayer. Virtual paths consisting of simulated GPS signals representing right and left turns separated by straight segments were simulated with four turning radii (75%, 125%, 250%, and 500%) based on boom width. Actual application rates from 11 nozzles spread across the boom were measured using load cells in …


Preliminary Analysis Of Ghg Production From The Lincoln Water System To Determine Operating Energy And Infrastructure Construction Impacts, Martin Gakuria May 2013

Preliminary Analysis Of Ghg Production From The Lincoln Water System To Determine Operating Energy And Infrastructure Construction Impacts, Martin Gakuria

Department of Environmental Engineering: Theses and Student Research

The Lincoln Water System (LWS) provides water to the citizens, industries, and commercial areas within and near the City of Lincoln, Nebraska. The intent of this thesis is to determine if reductions in future per capita water demand will help reduce the building of infrastructure and reduce future pumping costs and uses the computation of greenhouse gasses to compare the effects of different degrees of water conservation.

Data analysis was performed on water production statistics and data (1994-2011) collected and provided by the City of Lincoln, Nebraska. Projections in accordance with the Lincoln-Lancaster County 2040 Comprehensive Plan were made to …


Stormwater Pollution Treatment Bmp Discharge Structures, Miles F. Simmons May 2013

Stormwater Pollution Treatment Bmp Discharge Structures, Miles F. Simmons

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

Structural best management practices (BMPs) are used to capture and treat stormwater runoff. Most structural BMPs provide treatment by filtering runoff through a filter media or collecting it in a detention basin and slowly discharging it over an extended period of time to allow suspended solids and associated contaminants to settle out. The purpose of this study is to design an effective outlet structure that provides adequate filtration or slows discharge to 40 hours.

A model detention basin was constructed in the Civil Engineering Hydraulics Laboratory at the University of Nebraska-Lincoln (UNL) and two full scale outlet structures were tested …


Predicting Groundwater Trading Participation In The Upper Republican River Natural Resource District, Elizabeth M. Juchems May 2013

Predicting Groundwater Trading Participation In The Upper Republican River Natural Resource District, Elizabeth M. Juchems

Department of Agricultural Economics: Dissertations, Theses, and Student Research

The goal of this thesis is to predict participation in groundwater trading and the directions of trades among participants. Specifically, the paper considers both formal and informal trading of groundwater used for crop irrigation purposes and attempts to identify those characteristics that predict the probability of trade participation and whether an individual is a buyer or seller of groundwater rights. While the public benefits from efficient use of groundwater include adequate stream flow in hydrologically connected areas and future use of groundwater supplies, there are significant private benefits to landowners especially in water-short areas. Groundwater trading can help move water …


Soil Organic Carbon Dynamics In Agriculture: Model Development And Application From Daily To Decadal Timescales, Matthew P. Pelton May 2013

Soil Organic Carbon Dynamics In Agriculture: Model Development And Application From Daily To Decadal Timescales, Matthew P. Pelton

Department of Biological Systems Engineering: Dissertations and Theses

Soil carbon (C) is the largest terrestrial C pool globally, containing more C than the atmosphere and biosphere. Soil organic carbon (SOC) is a source and sink of CO2 emissions to and from the atmosphere, thus influencing future climate change. Understanding SOC dynamics is also important for maintaining C stocks to sustain and improve crop yields. An existing model to estimate changes in SOC due to respiration was modified to operate in three computational platforms: MS Excel, MS Excel with Visual Basic for Applications, and supercomputing. This model was validated against CO2 flux data from a 9-year field …


Building Upon Common-Pool Resource Theory To Explore Success In Transitioning Water Management Institutions, Christina M. Hoffman Apr 2013

Building Upon Common-Pool Resource Theory To Explore Success In Transitioning Water Management Institutions, Christina M. Hoffman

School of Natural Resources: Dissertations, Theses, and Student Research

Nebraska, like many regions around the world, is faced with the challenge of adapting to a new era in water management. Increasing demands for water resources, mounting concerns over threatened and endangered species, and obligations to abide by interstate water allocation agreements have motivated Nebraska to revisit traditional water management approaches. However, although Nebraska’s water management institutions have undergone much change, little research exists on the influence these changes have had on the ability of water institutions to successfully manage water allocations. This research (1) qualitatively explores the perspectives and experiences of stakeholders in the overappropriated region of the Platte …


2013 Nebraska Water Monitoring Programs Report, Marty Link, Joe Kenning Jan 2013

2013 Nebraska Water Monitoring Programs Report, Marty Link, Joe Kenning

Nebraska Department of Environmental Quality: Reports

The Nebraska Department of Environmental Quality (NDEQ) is charged with monitoring, assessing, and to the extent possible, managing the state’s water resources. The purpose of this work is to protect and maintain good quality water and encourage or execute activities to improve poor water quality. Monitoring is done on the over 16,000 miles of flowing rivers and streams, our greater than 148,000 acres of surface water in lakes and reservoirs, and the vast storage of groundwater in Nebraska’s aquifers.


Impact Of Water And Nitrogen Management Strategies On Maize Yield And Water Productivity Indices Under Linear-Move Sprinkler Irrigation, Daran Rudnick, Suat Irmak Jan 2013

Impact Of Water And Nitrogen Management Strategies On Maize Yield And Water Productivity Indices Under Linear-Move Sprinkler Irrigation, Daran Rudnick, Suat Irmak

Department of Biological Systems Engineering: Papers and Publications

With uncertainty in future irrigation water availability and regulations on nutrient application amounts, experimentally determined effects of “controllable” management strategies such as nitrogen (N), water, and their combination on crop water productivity (CWP, also known as crop water use efficiency) and actual evapotranspiration (ETa) are essential. The effects of various N application rates (0, 84, 140, 196, and 252 kg ha-1) under fully irrigated (FIT), limited irrigation (75% FIT), and rainfed conditions on maize (Zea mays L.) yield and various CWP indices were investigated in 2011 and 2012 growing seasons under linear-move sprinkler irrigation in south …


Variability Of Extreme Precipitation In Coastal River Basins Of The Southern Mexican Pacific Region, Nancy Perez-Morga, Thomas Kretzschmar, Tereza Cavazos, Stephen V. Smith, Francisco Munoz-Arriola Jan 2013

Variability Of Extreme Precipitation In Coastal River Basins Of The Southern Mexican Pacific Region, Nancy Perez-Morga, Thomas Kretzschmar, Tereza Cavazos, Stephen V. Smith, Francisco Munoz-Arriola

Department of Biological Systems Engineering: Papers and Publications

Extreme wet and dry years (± 1 standard deviation, respectively), as well as the top 95 percentile (P95) of daily precipitation events, derived from tropical cyclone (TC) and nontropical cyclone (NTC) rainfall, were analyzed in coastal river basins in Southern Oaxaca, Mexico (Río Verde, Río Tehuantepec, and the Southern Coast). The study is based on daily precipitation records from 47 quality-controlled stations for the 1961 to 1990 period and TC data for the Eastern Tropical Pacific (EPAC). The aim of this study was to evaluate extreme (dry and wet) trends in the annual contribution of daily P95 precipitation events and …


Use Of A Surrogate To Evaluate The Impact Of Tillage On The Transport Of Steroid Hormones From Manure-Amended Agricultural Fields, Sagor Biswas, William L. Kranz, Charles A. Shapiro, Mitiku Mamo, Shannon L. Bartelt-Hunt, Daniel D. Snow, David P. Shelton, David D. Tarkalson, Terry L. Mader, Simon J. Van Donk, Tian C. Zhang Jan 2013

Use Of A Surrogate To Evaluate The Impact Of Tillage On The Transport Of Steroid Hormones From Manure-Amended Agricultural Fields, Sagor Biswas, William L. Kranz, Charles A. Shapiro, Mitiku Mamo, Shannon L. Bartelt-Hunt, Daniel D. Snow, David P. Shelton, David D. Tarkalson, Terry L. Mader, Simon J. Van Donk, Tian C. Zhang

Department of Biological Systems Engineering: Papers and Publications

Beef feedlot manure distributed to row crop production areas is a potential surface water contaminant source of the steroid hormones commonly used in beef cattle production. This article reports on research conducted at the University of Nebraska Haskell Agricultural Laboratory near Concord, Nebraska, in July 2009. Manure, collected from beef feedlot pens, was stockpiled for ten months prior to application to a row crop field. Previous research identified that the detection frequency of steroid hormones in beef manure varies greatly. Thus, a surrogate (17α-ethynylestradiol, EE2) was applied at a rate of 75 g ha-1 to ensure detectable concentrations in …


Runoff Nutrient Transport As Affected By Land Application Method, Swine Growth Stage, And Runoff Rate, J. E. Gilley, Shannon L. Bartelt-Hunt, S. J. Lamb, X. Li, D. B. Marx, D. D. Snow, D. B. Parker, B. L. Woodbury Jan 2013

Runoff Nutrient Transport As Affected By Land Application Method, Swine Growth Stage, And Runoff Rate, J. E. Gilley, Shannon L. Bartelt-Hunt, S. J. Lamb, X. Li, D. B. Marx, D. D. Snow, D. B. Parker, B. L. Woodbury

Department of Biological Systems Engineering: Papers and Publications

This study was conducted to measure the effects of slurry application method, swine growth stage, and flow rate on runoff nutrient transport. Swine slurry was obtained from production units containing grower pigs, finisher pigs, or sows and gilts. The swine slurry was applied using broadcast, disk, or injection methods at a rate required to meet annual nitrogen requirements for corn. Three 30 min simulated rainfall events, separated by 24 h intervals, were applied to the experimental plots at an intensity of 70 mm h-1. Inflow was applied at the top of each plot in four successive increments after …


2013 Nebraska Groundwater Quality Monitoring Report Jan 2013

2013 Nebraska Groundwater Quality Monitoring Report

Nebraska Department of Environmental Quality: Reports

The 2001 Nebraska Legislature passed LB329 (Neb. Rev. Stat. §46-1304) which, in part, directed the Nebraska Department of Environmental Quality (NDEQ) to report on groundwater quality monitoring in Nebraska. Reports have been issued annually since December 2001. The text of the statute applicable to this report follows: “The Department of Environmental Quality shall prepare a report outlining the extent of ground water quality monitoring conducted by natural resources districts during the preceding calendar year. The department shall analyze the data collected for the purpose of determining whether or not ground water quality is degrading or improving and shall present the …


Maize Evapotranspiration, Yield Production Functions, Biomass, Grain Yield, Harvest Index, And Yield Response Factors Under Full And Limited Irrigation, Koffi Djaman, Suat Irmak, William R. Rathje, Derrel L. Martin, Dean E. Eisenhauer Jan 2013

Maize Evapotranspiration, Yield Production Functions, Biomass, Grain Yield, Harvest Index, And Yield Response Factors Under Full And Limited Irrigation, Koffi Djaman, Suat Irmak, William R. Rathje, Derrel L. Martin, Dean E. Eisenhauer

Department of Biological Systems Engineering: Papers and Publications

South-central Nebraska is one of the most extensively irrigated areas in the U.S., with over 65,000 active irrigation wells, and maize is the major agronomical crop produced. Maize production in this region requires supplementary irrigation for maximum productivity. Effective on-farm implementation of full and limited irrigation practices for potential improvements of crop productivity requires knowledge of locally developed crop yield response to water functions. In this study, the effects of full and limited irrigation practices on maize (Zea mays L.) plant height, leaf area index (LAI), grain yield and biomass production, actual crop evapotranspiration (ETa), yield production functions, …


Assessing Climate Change Impacts On Water Balance, Runoff, And Water Quality At The Field Scale For Four Locations In The Heartland, Michael W. Van Liew, Song Feng, T. B. Pathak Jan 2013

Assessing Climate Change Impacts On Water Balance, Runoff, And Water Quality At The Field Scale For Four Locations In The Heartland, Michael W. Van Liew, Song Feng, T. B. Pathak

Department of Biological Systems Engineering: Papers and Publications

This study employed the Soil and Water Assessment Tool (SWAT) to evaluate the impacts of projected future climate change scenarios on water balance, runoff, sediment, total nitrogen (N), and total phosphorus (P) at the field scale for four locations in the Heartland region: Sioux City (Iowa) and Columbus, Mullen, and Harrison (Nebraska). A conventional two-year corn-soybean rotation was assumed to be grown on each field. All fields were simulated identically in terms of topographic and cover/land management conditions. Model inputs for the fields differed in only

three ways: the forcing conditions for existing and future climatic scenarios (SRES A2, A1B, …


Use Of A Surrogate To Evaluate The Impact Of Tillage On The Transport Of Steroid Hormones From Manure-Amended Agricultural Fields, Sagor Biswas, William Kranz, Charles A. Shapiro, Mitiku Mamo, Shannon L. Bartelt-Hunt, Daniel D. Snow, David P. Shelton, David D. Tarkalson, Terry L. Mader, Simon J. Van Donk, Tian C. Zhang Jan 2013

Use Of A Surrogate To Evaluate The Impact Of Tillage On The Transport Of Steroid Hormones From Manure-Amended Agricultural Fields, Sagor Biswas, William Kranz, Charles A. Shapiro, Mitiku Mamo, Shannon L. Bartelt-Hunt, Daniel D. Snow, David P. Shelton, David D. Tarkalson, Terry L. Mader, Simon J. Van Donk, Tian C. Zhang

Department of Biological Systems Engineering: Papers and Publications

Beef feedlot manure distributed to row crop production areas is a potential surface water contaminant source of the steroid hormones commonly used in beef cattle production. This article reports on research conducted at the University of Nebraska Haskell Agricultural Laboratory near Concord, Nebraska, in July 2009. Manure, collected from beef feedlot pens, was stockpiled for ten months prior to application to a row crop field. Previous research identified that the detection frequency of steroid hormones in beef manure varies greatly. Thus, a surrogate (17α-ethynylestradiol, EE2) was applied at a rate of 75 g ha-1 to ensure detectable concentrations in …


Water Productivity Of Corn And Dry Bean Rotation On Very Fine Sandy Loam Soil In Western Nebraska, William E. Spurgeon, C. Dean Yonts Jan 2013

Water Productivity Of Corn And Dry Bean Rotation On Very Fine Sandy Loam Soil In Western Nebraska, William E. Spurgeon, C. Dean Yonts

Department of Biological Systems Engineering: Papers and Publications

Subsurface drip irrigation (SDI) was used to irrigate corn and dry beans in a crop rotation study for four years from 2005 to 2008 to evaluate the accumulative effect of irrigation amount on yield and irrigation water use efficiency (IWUE). This study was conducted on a very fine sandy loam soil using a short season corn hybrid typical for the area. Four irrigation treatments based on providing a fraction of the estimated crop evapotranspiration (ETc) were evaluated. The treatments were designed to replace a certain percentage of ETc and were denoted as I125, …


Development And Evaluation Of Ordinary Least Squares Regression Models For Predicting Irrigated And Rainfed Maize And Soybean Yields, Vivek Sharma, Daran R. Rudnick, Suat Irmak Jan 2013

Development And Evaluation Of Ordinary Least Squares Regression Models For Predicting Irrigated And Rainfed Maize And Soybean Yields, Vivek Sharma, Daran R. Rudnick, Suat Irmak

Department of Biological Systems Engineering: Papers and Publications

Understanding the relationships between climatic variables and soil physical and chemical properties with crop yields on large scales is critical for evaluating crop productivity to make better assessments of local and regional food security, policy, land and water resource allocation, and management decisions. In this study, ordinary least squares(OLS) regression models were developed to predict irrigated and rainfed maize and soybean yields at the county level as a

function of explanatory variables [precipitation (P), actual crop evapotranspiration (ETa), organic matter content (OMC), cation exchange capacity (CEC), clay content (CC), and available soil water capacity (ASW)] of the dominant soil type …


Transport Of Steroid Hormones In The Vadose Zone After Land Application Of Beef Cattle Manure, Simon Van Donk, Sagor Biswas, William L. Kranz, Daniel D. Snow, Shannon L. Bartelt-Hunt, Terry L. Mader, Charles A. Shapiro, David P. Shelton, David D. Tarkalson, Tian .. Zhang, Steve Ensley Jan 2013

Transport Of Steroid Hormones In The Vadose Zone After Land Application Of Beef Cattle Manure, Simon Van Donk, Sagor Biswas, William L. Kranz, Daniel D. Snow, Shannon L. Bartelt-Hunt, Terry L. Mader, Charles A. Shapiro, David P. Shelton, David D. Tarkalson, Tian .. Zhang, Steve Ensley

Department of Biological Systems Engineering: Papers and Publications

Few studies have been conducted to investigate the potential contamination of groundwater from manureborne steroid hormones. The objective of this study was to monitor leaching of steroid hormones at the bottom of 2.4 m deep percolation lysimeters installed in plots treated with beef cattle manure. Soil samples were also collected from surrounding field plots. Treatments consisted of application of manure from two treatment methods (stockpiling and composting) or no manure application. Laboratory analyses of manure, soil, and leachate samples used liquid chromatography and tandem mass spectrometry to identify 17 steroid hormones and metabolites. Progesterone, estrone, β-zearalenol, and 4-androstenedione were detected …


Implementation Of A ”Rapid Design Challenge” In A Cross-Disciplinary Senior Capstone Course And Evaluation Of Device Performance, Abby M. Kelly, Austin Lammers, David D. Jones, Richard Stowell, Roger Hoy, Evan Curtis, Angela K. Pannier Jan 2013

Implementation Of A ”Rapid Design Challenge” In A Cross-Disciplinary Senior Capstone Course And Evaluation Of Device Performance, Abby M. Kelly, Austin Lammers, David D. Jones, Richard Stowell, Roger Hoy, Evan Curtis, Angela K. Pannier

Department of Biological Systems Engineering: Papers and Publications

The senior capstone experience within the Department of Biological Systems Engineering at the University of Nebraska-Lincoln is a two-semester, two-course sequence intended to give senior students realistic design experience, working with real projects, real clients, faculty consultants, and teammates to produce a deliverable that meets the client’s needs. Students within this course sequence come from two different degree programs (agricultural engineering and biological systems engineering) and within each degree program from a variety of “emphasis areas”, e.g. biomedical engineering, environmental engineering, machine design. While the goal of this course is for students to experience a “real” design project, we felt …


Fate And Transport Of Antimicrobials And Antimicrobial Resistance Genes In Soil And Runoff Following Land Application Of Swine Manure Slurry, Stacy R. Joy, Shannon L. Bartelt-Hunt, Daniel D. Snow, John Gilley, Brian L. Woodbury, David B. Parker, David B. Marx, Xu Li Jan 2013

Fate And Transport Of Antimicrobials And Antimicrobial Resistance Genes In Soil And Runoff Following Land Application Of Swine Manure Slurry, Stacy R. Joy, Shannon L. Bartelt-Hunt, Daniel D. Snow, John Gilley, Brian L. Woodbury, David B. Parker, David B. Marx, Xu Li

Department of Civil and Environmental Engineering: Faculty Publications

Due to the use of antimicrobials in livestock production, residual antimicrobials and antimicrobial resistance genes (ARGs) could enter the environment following the land application of animal wastes and could further contaminate surface and groundwater. The objective of this study was to determine the effect of various manure land application methods on the fate and transport of antimicrobials and ARGs in soil and runoff following land application of swine manure slurry. Swine manure slurries were obtained from facilities housing pigs that were fed chlortetracyline, tylosin or bacitracin and were land applied via broadcast, incorporation, and injection methods. Three rainfall simulation tests …


Network Analysis Of Endogenous Gene Expression Profiles After Polyethyleneimine-Mediated Dna Delivery, Timothy M. Martin, Sarah A. Plautz, Angela K. Pannier Jan 2013

Network Analysis Of Endogenous Gene Expression Profiles After Polyethyleneimine-Mediated Dna Delivery, Timothy M. Martin, Sarah A. Plautz, Angela K. Pannier

Department of Biological Systems Engineering: Papers and Publications

Background—DNA delivery systems, which transport exogenous DNA to cells, have applications that include gene therapy, tissue engineering and medical devices. Although the cationic nonviral DNA carrier polyethyleneimine (PEI) has been widely studied, the molecular factors and pathways underlying PEI-mediated DNA transfer remain largely unknown, preventing the design of more efficient delivery systems.

Methods—HEK 293 T cells were treated with polyplexes formed with PEI and pEGFPLuc encoding for green fluorescent protein (GFP). Transfected cells expressing GFP were flowseparated from treated, untransfected cells. Gene expression profiles were obtained using Affymetrix HG-U133 2.0 microarrays and differentially expressed genes were identified using R/ Bioconductor. …


Hourly And Daily Single And Basal Evapotranspiration Crop Coefficients As A Function Of Growing Degree Days, Days After Emergence, Leaf Area Index, Fractional Green Canopy Cover, And Plant Phenology For Soybean, Suat Irmak, Lameck O. Odhiambo, James Specht, Koffi Djaman Jan 2013

Hourly And Daily Single And Basal Evapotranspiration Crop Coefficients As A Function Of Growing Degree Days, Days After Emergence, Leaf Area Index, Fractional Green Canopy Cover, And Plant Phenology For Soybean, Suat Irmak, Lameck O. Odhiambo, James Specht, Koffi Djaman

Department of Biological Systems Engineering: Papers and Publications

Hourly evapotranspiration (ET) crop coefficients (Kc) are needed to optimize the effectiveness and efficiency of high-frequency micro- and sprinkler irrigation practices involving the application of water multiple times a day. However, not much is known about the daily and seasonal patterns and magnitudes in hourly Kc values for soybean. In addition, locally developed Kc values are necessary for more robust within-season irrigation management, crop ET estimation, and water balance analyses. Hourly and daily Kc functions were developed for soybean in south-central Nebraska through extensive field research. Actual crop evapotranspiration (ETa) was measured using a …


Transferability Of Jarvis-Type Models Developed And Re-Parameterized For Maize To Estimate Stomatal Resistance Of Soybean: Analyses On Model Calibration, Validation, Performance, Sensitivity, And Elasticity, Denis Mutiibwa, Suat Irmak Jan 2013

Transferability Of Jarvis-Type Models Developed And Re-Parameterized For Maize To Estimate Stomatal Resistance Of Soybean: Analyses On Model Calibration, Validation, Performance, Sensitivity, And Elasticity, Denis Mutiibwa, Suat Irmak

Department of Biological Systems Engineering: Papers and Publications

In a previous study by the same authors, a new modified Jarvis model (NMJ-model) was developed, calibrated, and validated to estimate stomatal resistance (rs) for maize canopy on an hourly time step. The NMJ-model’s unique subfunctions, different from the original Jarvis model (J-model), include a photosynthetic photon flux density

(PPFD)-rs response subfunction developed from field measurements and a new physical term, Aexp(1/LAI), where A is the minimum stomatal resistance and LAI is the green leaf area index, to account for the influence of canopy development on rs, especially during partial canopy stage in the early season and …


Evapotranspiration And Surface Energy Balance Of A Common Reed-Dominated Riparian System In The Platte River Basin, Central Nebraska, Isa Kabenge, Suat Irmak, John E. Gilley, George E. Meyer, Stevan Z. Knezevic, Timothy J. Arkebauer, Duane Woodward, Milton Moravek Jan 2013

Evapotranspiration And Surface Energy Balance Of A Common Reed-Dominated Riparian System In The Platte River Basin, Central Nebraska, Isa Kabenge, Suat Irmak, John E. Gilley, George E. Meyer, Stevan Z. Knezevic, Timothy J. Arkebauer, Duane Woodward, Milton Moravek

Department of Biological Systems Engineering: Papers and Publications

Quantifying actual evapotranspiration (ETa) of riparian zones is important for more robust water balance analyses that will enable better planning, managing, and allocating of water resources as well as developing strategies to protect delicate riparian ecosystem functions. The ETa, sensible heat flux (H), net radiation (Rn), soil heat flux (G), meteorological variables (air temperature, Ta; incoming shortwave radiation, Rs; wind speed, u3; relative humidity, RH; vapor pressure deficit, VPD; precipitation, etc.), and albedo were measured on an hourly time step, and leaf area index (LAI) and plant height …