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Full-Text Articles in Other Civil and Environmental Engineering

Water-Stable Three-Dimensional Ultrafine Fibrous Scaffolds From Keratin For Cartilage Tissue Engineering, Helan Xu, Shaobo Cai, Lan Xu, Yiqi Yang Jan 2014

Water-Stable Three-Dimensional Ultrafine Fibrous Scaffolds From Keratin For Cartilage Tissue Engineering, Helan Xu, Shaobo Cai, Lan Xu, Yiqi Yang

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Intrinsically water-stable scaffolds composed of ultrafine keratin fibers oriented randomly and evenly in three dimensions were electrospun for cartilage tissue engineering. Keratin has been recognized as a biomaterial that could substantially support the growth and development of multiple cell lines. Besides, three-dimensional (3D) ultrafine fibrous structures were preferred in tissue engineering due to their structural similarity to native extracellular matrices in soft tissues. Recently, we have developed a nontraditional approach to developing 3D fibrous scaffolds from alcohol-soluble corn protein, zein, and verified their structural advantages in tissue engineering. However, keratin with highly cross-linked molecular structures could not be readily dissolved …


Intrinsically Water-Stable Keratin Nanoparticles And Their In Vivo Biodistribution For Targeted Delivery, Helan Xu, Zhen Shi, Narendra Reddy, Yiqi Yang Jan 2014

Intrinsically Water-Stable Keratin Nanoparticles And Their In Vivo Biodistribution For Targeted Delivery, Helan Xu, Zhen Shi, Narendra Reddy, Yiqi Yang

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Highly water-stable nanoparticles of around 70 nm and capable of distributing with high uptake in certain organs of mice were developed from feather keratin. Nanoparticles could provide novel veterinary diagnostics and therapeutics to boost efficiency in identification and treatment of livestock diseases to improve protein supply and ensure safety and quality of food. Nanoparticles could penetrate easily into cells and small capillaries, surpass detection of the immune system, and reach targeted organs because of their nanoscale sizes. Proteins with positive and negative charges and hydrophobic domains enable loading of various types of drugs and, hence, are advantageous over synthetic polymers …


Development And Testing Of An In-Stream Phosphorus Cycling Model For The Soil And Water Assessment Tool, Michael J. White, Daniel E. Storm, Aaron R. Mittelstet, Philip R. Busteed, Brian E. Haggard, Colleen Rossi Jan 2014

Development And Testing Of An In-Stream Phosphorus Cycling Model For The Soil And Water Assessment Tool, Michael J. White, Daniel E. Storm, Aaron R. Mittelstet, Philip R. Busteed, Brian E. Haggard, Colleen Rossi

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The Soil and Water Assessment Tool is widely used to predict the fate and transport of phosphorus (P) from the landscape through streams and rivers. The current in-stream P submodel may not be suitable for many stream systems, particularly those dominated by attached algae and those affected by point sources. In this research, we developed an alternative submodel based on the equilibrium P concentration concept coupled with a particulate scour and deposition model. This submodel was integrated with the SWAT model and applied to the Illinois River Watershed in Oklahoma, a basin influenced by waste water treatment plant discharges and …


The Hydraulic Conductivity Structure Of Gravel-Dominated Vadose Zones Within Alluvial Floodplains, Ronald B. Miller, Derek M. Heeren, Garey A. Fox, Todd Halihan, Daniel E. Storm, Aaron R. Mittelstet Jan 2014

The Hydraulic Conductivity Structure Of Gravel-Dominated Vadose Zones Within Alluvial Floodplains, Ronald B. Miller, Derek M. Heeren, Garey A. Fox, Todd Halihan, Daniel E. Storm, Aaron R. Mittelstet

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The floodplains of many gravel-bed streams have a general stratigraphy that consists of a layer of topsoil covering gravel-dominated subsoil. Previous research has demonstrated that this stratigraphy can facilitate preferential groundwater flow through focused linear features, such as paleochannels, or gravelly regions within the vadose zone. These areas within the floodplain vadose zone may provide a route for interactions between the floodplain surface and alluvial groundwater, effectively extending the hyporheic zone across the floodplain during high stream stage. The objective of this research was to assess the structure and scale of texture heterogeneity within the vadose zone within the gravel …


Simulation Supported Estimation Of End-To-End Transmission Parameters In Non-Viral Gene Delivery, Beata J. Wysocki, Tadeusz A. Wysocki, Timothy M. Martin, Angela K. Pannier Jan 2014

Simulation Supported Estimation Of End-To-End Transmission Parameters In Non-Viral Gene Delivery, Beata J. Wysocki, Tadeusz A. Wysocki, Timothy M. Martin, Angela K. Pannier

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Communications, in general, involve delivery of information from a source to a sink. At nano-scale, an example of a man-made communications involving interfacing with biological systems at intra-cellular level is non-viral gene delivery. From a telecommunications engineering perspective, important end-to-end parameters of such a system are: the endto- end delay, system capacity, and packet loss rate. There are neither known methods to estimate those parameters theoretically nor they are ready available from standard measurements. The paper provides estimates for those parameters based on the simulation of non-viral gene delivery system based on the queuing theory. The simulator used has been …


Alginate/Silica Hybrid Materials For Immobilization Of Green Microalgae Chlorella Vulgaris For Cellbased Sensor Arrays, Angela K. Pannier, Ulrich Soltmann, Bettina Soltmann, Rolf Altenburger, Mechthild Schmitt-Jansen Jan 2014

Alginate/Silica Hybrid Materials For Immobilization Of Green Microalgae Chlorella Vulgaris For Cellbased Sensor Arrays, Angela K. Pannier, Ulrich Soltmann, Bettina Soltmann, Rolf Altenburger, Mechthild Schmitt-Jansen

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Thin layers and patterned dot arrays of sodium alginate containing living microalgal cells were deposited onto glass carriers which were subsequently gelled using amino-functionalized silica sol to obtain reinforced alginate hydrogels. The resulting alginate/silica hybrid materials showed improved stability in salt-containing solutions compared to alginate gels gelled by traditional methods using Ca2+-ions. Cell arrays were patterned by printing nanolitre-scale drops of sodium alginate/cell suspension using a noncontact micro-dosage system which allows the printing of solutions of high viscosity. Cultures of the green microalga Chlorella vulgaris were immobilized within the newly developed alginate/silica hydrogels in order to demonstrate the …


In Vitro Development Of Preimplantation Porcine Embryos Using Alginate Hydrogels As A Three-Dimensional Extracellular Matrix, Catherine Sargus-Patino, Elane C. Wright, Sarah A. Plautz, Jeremy R. Miles, Jeff L. Vallet, Angela K. Pannier Jan 2014

In Vitro Development Of Preimplantation Porcine Embryos Using Alginate Hydrogels As A Three-Dimensional Extracellular Matrix, Catherine Sargus-Patino, Elane C. Wright, Sarah A. Plautz, Jeremy R. Miles, Jeff L. Vallet, Angela K. Pannier

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Between Days 10 and 12 of gestation, porcine embryos undergo a dramatic morphological change, known as elongation, with a corresponding increase in oestrogen production that triggers maternal recognition of pregnancy. Elongation deficiencies contribute to embryonic loss, but exact mechanisms of elongation are poorly understood due to the lack of an effective in vitro culture system. Our objective was to use alginate hydrogels as three-dimensional scaffolds that can mechanically support the in vitro development of preimplantation porcine embryos. White cross-bred gilts were bred at oestrus (Day 0) to Duroc boars and embryos were recovered on Days 9, 10 or 11 of …


Long-Term Activity Of Biohybrid Coatings Of Atrazine-Degrading Bacteria Pseudomonas Sp. Adp, Angela K. Pannier, T. Lehrer, M. Vogel, U. Soltmann, H. Bottcher, S. Tarre, M. Green, J. Raff, K. Pollmann Jan 2014

Long-Term Activity Of Biohybrid Coatings Of Atrazine-Degrading Bacteria Pseudomonas Sp. Adp, Angela K. Pannier, T. Lehrer, M. Vogel, U. Soltmann, H. Bottcher, S. Tarre, M. Green, J. Raff, K. Pollmann

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The atrazine-degrading bacterial strain Pseudomonas sp. ADP was immobilized by the sol–gel process within thin silica layers coated onto water-retaining carrier materials (expanded clay pellets and scoria). The performance of the obtained biohybrid material has been investigated concerning long-term activity under non-growth conditions. Experiments were run in phosphate buffer containing atrazine (20 mg l-1) as the sole source of carbon and nitrogen. Even after one year of consecutive batch tests, P. ADP immobilized onto expanded clay pellets showed a high atrazine degradation activity. In the course of long-term batch experiments, the average amount of removed atrazine was about …


Nutrient Concentrations Of Runoff As Affected By The Diameter Of Unconsolidated Material From Feedlot Surfaces, John E. Gilley, Gregory Boone, David B. Marx Jan 2014

Nutrient Concentrations Of Runoff As Affected By The Diameter Of Unconsolidated Material From Feedlot Surfaces, John E. Gilley, Gregory Boone, David B. Marx

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Beef cattle feedlots contain unconsolidated material that accumulates on the feedlot surface during a feeding cycle. This study was conducted to measure the effects of varying diameters of unconsolidated surface material and varying flow rates on nutrient concentrations in runoff. Unconsolidated surface material with an average diameter of 4.76, 9.53, 19.1, or 47.5 mm and a composite sample with a 15.2 mm mean diameter were placed within 0.75 m wide × 4.0 m long plot areas. Flow was then introduced at the top of the plots in successive increments, and runoff samples for water quality analyses were obtained. Particle diameter …


Dynamic Analysis Of Dna Nanoparticle Immobilization To Model Biomaterial Substrates Using Combinatorial Spectroscopic Ellipsometry And Quartz Crystal Microbalance With Dissipation, Tadas Kasputis, Alex Pieper, Mathias Schubert, Angela K. Pannier Jan 2014

Dynamic Analysis Of Dna Nanoparticle Immobilization To Model Biomaterial Substrates Using Combinatorial Spectroscopic Ellipsometry And Quartz Crystal Microbalance With Dissipation, Tadas Kasputis, Alex Pieper, Mathias Schubert, Angela K. Pannier

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Gene expression within cells can be altered through gene delivery approaches, which have tremendous potential for gene therapy, tissue engineering, and diagnostics. Substrate-mediated gene delivery describes the delivery of plasmid DNA or DNA complexed with nonviral vectors to cells from a surface, with the DNA immobilized to a substrate through specific or nonspecific interactions. In this work, DNA-nanoparticle (DNA–NP) adsorption to substrates is evaluated using combinatorial, in situ spectroscopic ellipsometry and quartz crystal microbalance with dissipation (SE/QCM-D), to evaluate the basic dynamic processes involved in the adsorption and immobilization of DNA–NP complexes to substrates. The concentration of DNA–NP solutions influences …


Seed Tape Effects On Corn Emergence Under Greenhouse Conditions, Ramarao Venkatesh, Peter R. Thomison, Colette K. Gabriel, Mark A. Bennett, Elaine M. Grassbaugh, Matthew D. Kleinhenz, Scott A. Shearer, Santosh Pitla Jan 2014

Seed Tape Effects On Corn Emergence Under Greenhouse Conditions, Ramarao Venkatesh, Peter R. Thomison, Colette K. Gabriel, Mark A. Bennett, Elaine M. Grassbaugh, Matthew D. Kleinhenz, Scott A. Shearer, Santosh Pitla

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Seed tape has recently received attention as an alternative planting system for smallholder farmers in underdeveloped regions of South America, Africa, China, and India (Mateus, 2014). Seed companies are also developing seed-tape planting systems for germplasm evaluations (Deppermann et al., 2013). Although seed tape has been promoted as a method for ensuring uniform seed spacing and plant density of small-seeded flowers, herbs, and vegetables (Chancellor, 1969), little or no information is available on the use of seed tape for larger-seeded row crops and its effect on crop emergence. The objective of this study was to compare the emergence of corn …


Soybean Yield, Evapotranspiration, Water Productivity, And Soil Water Extraction Response To Subsurface Drip Irrigation And Fertigation, Suat Irmak, James E. Specht, Lameck O. Odhiambo, J. M. Rees, K. G. Cassman Jan 2014

Soybean Yield, Evapotranspiration, Water Productivity, And Soil Water Extraction Response To Subsurface Drip Irrigation And Fertigation, Suat Irmak, James E. Specht, Lameck O. Odhiambo, J. M. Rees, K. G. Cassman

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Soybean [Glycine max (L.) Merr.] yield, irrigation water use efficiency (IWUE), crop water use efficiency (CWUE), evapotranspiration water use efficiency (ETWUE), and soil water extraction response to eleven treatments of full, limited, or delayed irrigation versus a rainfed control were investigated using a subsurface drip irrigation (SDI) system at a research site in south-central Nebraska. The SDI system laterals were 0.40 m deep in every other row middle of 0.76 m spaced plant rows. Actual evapotranspiration (ETa) was quantified in all treatments and used to schedule irrigation events on a 100% ETa replacement basis in all but …


Combined Qcm-D/Ge As A Tool To Characterize Stimuli-Responsive Swelling Of And Protein Adsorption On Polymer Brushes Grafted Onto 3d-Nanostructures, Meike Koenig, Tadas Kasputis, Daniel Schmidt, Keith B. Rodenhausen Jr., Klaus-Jochen Eichhorn, Angela K. Pannier, Mathias Schubert, Manfred Stamm, Petra Uhlmann Jan 2014

Combined Qcm-D/Ge As A Tool To Characterize Stimuli-Responsive Swelling Of And Protein Adsorption On Polymer Brushes Grafted Onto 3d-Nanostructures, Meike Koenig, Tadas Kasputis, Daniel Schmidt, Keith B. Rodenhausen Jr., Klaus-Jochen Eichhorn, Angela K. Pannier, Mathias Schubert, Manfred Stamm, Petra Uhlmann

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A combined setup of quartz crystal microbalance and generalized ellipsometry can be used to comprehensively investigate complex functional coatings comprising stimuli-responsive polymer brushes and 3D nanostructures in a dynamic, noninvasive in situ measurement. While the quartz crystal microbalance detects the overall change in areal mass, for instance, during a swelling or adsorption process, the generalized ellipsometry data can be evaluated in terms of a layered model to distinguish between processes occurring within the intercolumnar space or on top of the anisotropic nanocolumns. Silicon films with anisotropic nanocolumnar morphology were prepared by the glancing angle deposition technique and further functionalized by …


Parallel Synthesis Of Poly(Amino Ether)-Templated Plasmonic Nanoparticles For Transgene Delivery, James Ramos, Thrimoorthy Potta, Olivia Scheideler, Kaushal Rege Jan 2014

Parallel Synthesis Of Poly(Amino Ether)-Templated Plasmonic Nanoparticles For Transgene Delivery, James Ramos, Thrimoorthy Potta, Olivia Scheideler, Kaushal Rege

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Plasmonic nanoparticles have been increasingly investigated for numerous applications in medicine, sensing, and catalysis. In particular, gold nanoparticles have been investigated for separations, sensing, drug/nucleic acid delivery, and bioimaging. In addition, silver nanoparticles demonstrate antibacterial activity, resulting in potential application in treatments against microbial infections, burns, diabetic skin ulcers, and medical devices. Here, we describe the facile, parallel synthesis of both gold and silver nanoparticles using a small set of poly(amino ethers), or PAEs, derived from linear polyamines, under ambient conditions and in absence of additional reagents. The kinetics of nanoparticle formation were dependent on PAE concentration and chemical composition. …


Surface-Enhanced Raman Spectral Biomarkers Correlate With Ankle Brachial Index And Characterize Leg Muscle Biochemical Composition Of Patients With Peripheral Arterial Disease, Kim Cluff, Abby M. Kelly, Panagiotis Koutakis, Xiang N. He, Xi Huang, Yongfeng Lu, Iraklis I. Pipinos, George P. Casale, Jeyamkondan Subbiah Jan 2014

Surface-Enhanced Raman Spectral Biomarkers Correlate With Ankle Brachial Index And Characterize Leg Muscle Biochemical Composition Of Patients With Peripheral Arterial Disease, Kim Cluff, Abby M. Kelly, Panagiotis Koutakis, Xiang N. He, Xi Huang, Yongfeng Lu, Iraklis I. Pipinos, George P. Casale, Jeyamkondan Subbiah

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Peripheral arterial disease (PAD) is characterized by atherosclerotic blockages of the arteries supplying the lower extremities, which cause a progressive accumulation of ischemic injury to the skeletal muscles of the lower limbs. This injury includes altered metabolic processes, damaged organelles, and compromised bioenergetics in the affected muscles. The objective of this study was to explore the association of Raman spectral signatures of muscle biochemistry with the severity of atherosclerosis in the legs as determined by the Ankle Brachial Index (ABI) and clinical presentation. We collected muscle biopsies from the gastrocnemius (calf muscle) of five patients with clinically diagnosed claudication, five …


Use Of Controller Area Network (Can) Data To Determine Field Efficiencies Of Agricultural Machinery, Santosh Pitla, N. Lin, Joe D. Luck, Scott A. Shearer Jan 2014

Use Of Controller Area Network (Can) Data To Determine Field Efficiencies Of Agricultural Machinery, Santosh Pitla, N. Lin, Joe D. Luck, Scott A. Shearer

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Controller Area Network (CAN) bus is used on current agricultural equipment for in-vehicle communication among multiple microcontrollers. In this study, CAN data was collected from the tractor diagnostic port during three field operations: anhydrous ammonia (NH3) application, field cultivation, and planting. Specifically, CAN messages corresponding to engine fuel use rate were filtered, decoded, and analyzed. High fuel use rates were recorded from the tractor when implements were engaged in the soil compared to when the implements were lifted out of the ground at the end of the passes or, when the tractor was turning and idling. Threshold fuel …


A Simple Method For Estimation Of Queue Length, S. P. Anusha, Lelitha Devi Vanajakshi, Anuj Sharma Dec 2013

A Simple Method For Estimation Of Queue Length, S. P. Anusha, Lelitha Devi Vanajakshi, Anuj Sharma

Department of Civil and Environmental Engineering: Faculty Publications

Urban arterials are characterized by frequent intersections. Queue length and delay are the two primary measures of performance of intersection. These measures play a primary role in determining the arterial performance. This article presents a methodology to determine the number of vehicles in queue at a signalized intersection for under saturated traffic conditions. The results obtained were validated using actual values that are manually extracted. The root-mean-square error is of the range 1.3 vehicles for estimation of number of vehicles in queue. The various aspects that have to be considered in accurate estimation of performance measures are also discussed.


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 Agricultural and Biological Systems Engineering: Faculty 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 …


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, Wesley M. Porter, Jorge A. Rascon, Yeyin Shi, Randal K. Taylor, Paul A. Weckler Jun 2013

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

Department of Agricultural and Biological Systems Engineering: Faculty 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 …


Preparing Nebraska Future Water Leaders: Nwla Academy Class Iii (2013), Connie I. Reimers-Hild Mar 2013

Preparing Nebraska Future Water Leaders: Nwla Academy Class Iii (2013), Connie I. Reimers-Hild

Nebraska Water Leaders Academy: Publications and Materials

Group communications, Phyllis Schoenholz, UNL

Communication and transformational leadership. Dr. Mark Burbach and Dr. Connie Reimers-Hild, UNL

Nebraska's instream flow laws and applications, Ann Bleed, board member, Lower Platte Natural Resources District

River Basin Compacts; Nebraska's obligations, Michael Jess, water resources engineer; consultant.

Conservation along the Central Platte, Mark Peyton, senior biologist, Central Nebraska Public Power and Irrigation District

Central Platte River water issues in regard to habitat for endangered species, Jason Farnsworth, natural resources specialist, Headwaters Corporation & Jerry Kenny, executive director of the Platte River Recovery Implementation Program

Rowe Sanctuary; discussion and viewing …


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 Agricultural and Biological Systems Engineering: Faculty 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 …


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 Agricultural and Biological Systems Engineering: Faculty 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 …


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 Agricultural and Biological Systems Engineering: Faculty 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 Agricultural and Biological Systems Engineering: Faculty 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 …


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 Agricultural and Biological Systems Engineering: Faculty 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 …


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 Agricultural and Biological Systems Engineering: Faculty 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, …


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 Agricultural and Biological Systems Engineering: Faculty 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 …


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 Agricultural and Biological Systems Engineering: Faculty 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 …


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 Agricultural and Biological Systems Engineering: Faculty 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 …