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Bioresource and Agricultural Engineering Commons

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2012

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Articles 91 - 120 of 121

Full-Text Articles in Bioresource and Agricultural Engineering

The ‘Porin–Cytochrome’ Model For Microbe-To-Mineral Electron Transfer, David Richardson, Julea Butt, James K. Fredrickson, John M. Zachara, Liang Shi, Marcus Edwards, Gaye White, Nanakow Baiden, Andrew Gates, Sophie Marritt, Thomas Clarke Jan 2012

The ‘Porin–Cytochrome’ Model For Microbe-To-Mineral Electron Transfer, David Richardson, Julea Butt, James K. Fredrickson, John M. Zachara, Liang Shi, Marcus Edwards, Gaye White, Nanakow Baiden, Andrew Gates, Sophie Marritt, Thomas Clarke

United States Department of Energy: Publications

Many species of bacteria can couple anaerobic growth to the respiratory reduction of insoluble minerals containing Fe(III) or Mn(III/IV). It has been suggested that in Shewanella species electrons cross the outer membrane to extracellular substrates via ‘porin–cytochrome’ electron transport modules. The molecular structure of an outer-membrane extracellular-facing deca-haem terminus for such a module has recently been resolved. It is debated how, once outside the cells, electrons are transferred from outer-membrane cytochromes to insoluble electron sinks. This may occur directly or by assemblies of cytochromes, perhaps functioning as ‘nanowires’, or via electron shuttles. Here we review recent work in this field …


Assessment Of Conductivity Sensors Performance For Monitoring Mined Land Discharged Waters And An Evaluation Of The Hydrologic Performance Of The Guy Cove Stream Restoration Project, Travis Pritchard Maupin Jan 2012

Assessment Of Conductivity Sensors Performance For Monitoring Mined Land Discharged Waters And An Evaluation Of The Hydrologic Performance Of The Guy Cove Stream Restoration Project, Travis Pritchard Maupin

Theses and Dissertations--Biosystems and Agricultural Engineering

The surface mining method of mountaintop removal has been shown to adversely affect the water quality and hydrologic characteristics of downstream regions. Based on recent scientific literature, the U.S. EPA issued guidance on the specific conductivity (EC25ºC) of waters discharged from mined lands in the Appalachian Coal Belt Region stating that these waters should have an EC25ºC less than 300-500 μS cm-1. Hence, accurately measuring EC25ºC levels of mine discharged waters has significant implications. Furthermore, the development of reclamation techniques that positively impact the hydrological and water quality aspects of valley fill (VF) discharge is needed. To tackle these questions, …


Evaluation Of Transitions For Testing Agricultural Ventilation Fans With The Fan Assessment Numeration System (Fans), Igor Moreira Lopes Jan 2012

Evaluation Of Transitions For Testing Agricultural Ventilation Fans With The Fan Assessment Numeration System (Fans), Igor Moreira Lopes

Theses and Dissertations--Biosystems and Agricultural Engineering

The Fan Assessment Numeration System (FANS) is an improved air velocity traverse method for measuring in situ fan performance. The FANS has been widely used, but variations of its test procedure are commonly employed to accommodate physical or operational barriers encountered in the field. This laboratory study evaluated the use of transitions to connect a 1.37m FANS unit to two smaller fans (1.22m and 0.91m diameter) and one 1.37m diameter fan. Tests were conducted with the FANS unit positioned on both intake and discharge sides of the fans. Three different transition angles (30o, 45o and 60o …


Development Of A Noncontact Sensor For Monitoring Milk Coagulation And Cutting Time Prediction In Cheese Making, Molly D. Craft-Jenkins Jan 2012

Development Of A Noncontact Sensor For Monitoring Milk Coagulation And Cutting Time Prediction In Cheese Making, Molly D. Craft-Jenkins

Theses and Dissertations--Biosystems and Agricultural Engineering

Cheese products are manufactured more consistently and with better quality if the curd cutting time can be consistently selected. An optical sensor that accurately predicts cutting time has been developed for large cheese vats, but the initial cost of these sensors makes them uneconomical for small artisan cheese manufacturers. The small artisan cheese vats require an inexpensive sensor technology that can be implemented simply. The initial cost of purchasing a sensor and installing these sensors plus the need for a computational program for implementing the algorithm make this technology excessively expensive for these smaller cheese manufacturers. The objective of this …


Evaluation Of Separation Method Additives For The Recovery Of Bacteria From Food Matrices, Jennifer Leanne Frederick Jan 2012

Evaluation Of Separation Method Additives For The Recovery Of Bacteria From Food Matrices, Jennifer Leanne Frederick

Theses and Dissertations--Biosystems and Agricultural Engineering

The microbiological testing of foods is a well-established science. Due to the severity of foodborne pathogen illnesses, the widespread use and implementation of rapid detection methods in food testing labs is increasingly important. The first step for successful testing is sampling. Surfactants have been highly used in food microbiology, but there is not much, if any, published research about the use of fatty alcohols and chemical dispersants as aids in microbial separation. The microbial extraction efficiency of Escherichia coli K12 and Listeria innocua from hot dogs, spinach, and milk was measured using chemical additives (surfactants, fatty alcohols, and a chemical …


Computational Tools For Improving Route Planning In Agricultural Field Operations, Rodrigo S. Zandonadi Jan 2012

Computational Tools For Improving Route Planning In Agricultural Field Operations, Rodrigo S. Zandonadi

Theses and Dissertations--Biosystems and Agricultural Engineering

In farming operation, machinery represents a major cost; therefore, good fleet management can have a great impact on the producer’s profit, especially considering the increasing costs of fuel and production inputs in recent years. One of the tasks to be accomplished in order to improve fleet management is planning the path that the machine should take to cover the field while working. Information such as distance traveled, time and fuel consumption as well as agricultural inputs wasted due to off-target-application areas are crucial in the path planning process. Parameters such as field boundary size and geometry, machine total width as …


Evaluating The Effectiveness Of Weep Berm Systems For Treating Runoff From A Horse Muck Composting Operation, Ross L. Guffey Jan 2012

Evaluating The Effectiveness Of Weep Berm Systems For Treating Runoff From A Horse Muck Composting Operation, Ross L. Guffey

Theses and Dissertations--Biosystems and Agricultural Engineering

Two contour weep berms systems were designed and implemented to evaluate their performance at mitigating water quantity problems from a horse muck composting operation. The field-scale study focused on the hydrologic response of a standard contour weep berm and a modified contour weep berm. The modified contour weep berm incorporated a woodchip trench upgradient of a typical standard contour weep design. Monitoring occurred from July 2011 through spring 2012. Eight storm events produced measureable runoff for the standard contour weep berm; however, only five storm events produced measurable runoff for the modified contour weep berm. The largest storm event occurred …


Development And Deployment Of A Bioreactor For The Removal Of Sulfate And Manganese From Circumneutral Coal Mine Drainage, C. B. Mastin, J. D. Edwards, Christopher D. Barton, Anastasios D. Karathanasis, Carmen T. Agouridis, Richard C. Warner Jan 2012

Development And Deployment Of A Bioreactor For The Removal Of Sulfate And Manganese From Circumneutral Coal Mine Drainage, C. B. Mastin, J. D. Edwards, Christopher D. Barton, Anastasios D. Karathanasis, Carmen T. Agouridis, Richard C. Warner

Forestry and Natural Resources Faculty Publications

Surface mining, in the form of contour mining and mountain-top removal, is a common means for retrieving coal in the Appalachian Coal Belt region of Kentucky. Overburden or excess spoil generated by these two methods is placed in valley fills. Traditionally Constructed fills have been shown to adversely impact headwater ecosystems via stream burial and through alterations to the hydrology, sediment supply, water quality and biological composition of downstream reaches. Mine drainages emanating from the toe of valley fills often contain elevated levels of total dissolved solids and heavy metals. Drainage chemistry from Guy Cove, a valley fill located in …


Evaluation Of Algae Concentration In Manure Based Media, Maira Freire Pecegueiro Do Amaral Jan 2012

Evaluation Of Algae Concentration In Manure Based Media, Maira Freire Pecegueiro Do Amaral

Theses and Dissertations--Biosystems and Agricultural Engineering

Algae can be used to treat wastewater and manure while producing a feedstock for renewable energy. Algae require nutrients to achieve their maximum growth and manure could provide those nutrients, thereby reducing the cost of algae production and the impact of manure treatment. Algae concentration during cultivation is a critical variable that is difficult to measure due to the high concentration of suspended solids present in manure. This dissertation addresses methods to measure algae concentration in the presence of manure solids.

Quantifying the algae concentration gravimetrically or by optical density was unreliable due to manure solids interfering with the measurement. …


Automated System To Improve Levelness Of Reconstructed Soil, Venkata Srikiran Bodapati, Larry G. Wells Jan 2012

Automated System To Improve Levelness Of Reconstructed Soil, Venkata Srikiran Bodapati, Larry G. Wells

Biosystems and Agricultural Engineering Faculty Publications

Extraction of coal, ores, and minerals from the earth by surface mining has occurred for many years and has always presented a significant challenge with regard to restoration of productive soil to mined areas. Federal and state regulations require that land should be returned to pre-mine productivity or reclaimed as per specific standards following mining. Excessive compaction of reconstructed soil caused by traffic of heavy earth moving equipment has been an enduring challenge regarding successful restoration of soil. A mechanical system was previously designed and developed to reconstruct soil to a depth of 1.22 m (48 in.) while completely avoiding …


Prescribed Grazing On Pasturelands, Lynn E. Sollenberger, Carmen T. Agouridis, Eric S. Vanzant, Alan J. Franzluebbers, Lloyd B. Owens Jan 2012

Prescribed Grazing On Pasturelands, Lynn E. Sollenberger, Carmen T. Agouridis, Eric S. Vanzant, Alan J. Franzluebbers, Lloyd B. Owens

Biosystems and Agricultural Engineering Faculty Publications

No abstract provided.


Methane And Carbon Dioxide Production From Simulated Anaerobic Degradation Of Cattle Carcasses, Qi Yuan, Samuel Saunders, Shannon L. Bartelt-Hunt Jan 2012

Methane And Carbon Dioxide Production From Simulated Anaerobic Degradation Of Cattle Carcasses, Qi Yuan, Samuel Saunders, Shannon L. Bartelt-Hunt

Department of Civil and Environmental Engineering: Faculty Publications

Approximately 2.2 million cattle carcasses require disposal annually in the United States. Land burial is a convenient disposal method that has been widely used in animal production for disposal of both daily mortalities as well as during catastrophic mortality events. To date, greenhouse gas production after mortality burial has not been quantified, and this study represents the first attempt to quantify greenhouse gas emissions from land burial of animal carcasses. In this study, anaerobic decomposition of both homogenized and unhomogenized cattle carcass material was investigated using bench-scale reactors. Maximum yields of methane and carbon dioxide were 0.33 and 0.09 m …


Soil Phosphorus Availability And Buffering Capacity In Eastern South Dakota Assessed Using Quantity-Intensity Relationships And Diffusive Gradients In Thin Films, Rose Eitemiller Jan 2012

Soil Phosphorus Availability And Buffering Capacity In Eastern South Dakota Assessed Using Quantity-Intensity Relationships And Diffusive Gradients In Thin Films, Rose Eitemiller

Electronic Theses and Dissertations

Phosphorus (P) availability is influenced by soil properties and depth, creating challenges for nutrient management across agricultural landscapes. This study evaluated two complementary approaches for quantifying P availability and adsorption dynamics in eastern South Dakota soils: Diffusive Gradients in Thin Films (DGT) and P quantity–intensity (Q–I) relationships. The objectives were to (1) quantify bioavailable P using DGT, (2) compare DGT measurements with established soil test P (STP), (3) evaluate Q–I parameters describing P adsorption characteristics, and (4) assess spatial variability in P availability across eastern South Dakota soils. DGT-measured P increased with STP levels and was strongly correlated with Bray-1, …


Coupled Electromagnetic And Heat Transfer Model For Microwave Heating In Domestic Ovens, Krishnamoorthy Pitchai, Sohan Birla, Jeyamkondan Subbiah, D. D. Jones, Harshanardhan Thippareddi Jan 2012

Coupled Electromagnetic And Heat Transfer Model For Microwave Heating In Domestic Ovens, Krishnamoorthy Pitchai, Sohan Birla, Jeyamkondan Subbiah, D. D. Jones, Harshanardhan Thippareddi

Department of Food Science and Technology: Faculty Publications

Microwave ovens are used extensively for heating a variety of not-ready-to-eat food products. Non-uniform heating of foods in microwave ovens is a major concern in assuring microbiological safety of such products. The non-uniform heating of foods is attributed by complex interaction of microwaves with foods. To understand this complex interaction, a comprehensive model was developed to solve coupled electromagnetic and heat transfer equations using finite-difference time-domain based commercial software. The simulation parameters, cell size, heating time step, and number of iterations for steady state electromagnetic field were optimized. The model was validated by 30 s heating profile of a cylindrical …


An Investigation Of Reflective Mulches For Use Over Capillary Mat Systems For Winter-Time Greenhouse Strawberry Production, George E. Meyer, Ellen T. Paparozzi, Elizabeth Walter-Shea, Erin E. Blankenship, Stacy A. Adams Jan 2012

An Investigation Of Reflective Mulches For Use Over Capillary Mat Systems For Winter-Time Greenhouse Strawberry Production, George E. Meyer, Ellen T. Paparozzi, Elizabeth Walter-Shea, Erin E. Blankenship, Stacy A. Adams

Department of Agronomy and Horticulture: Faculty Publications

Photosynthethically active radiation (PAR) is a principle environmental variable used by horticultural specialists, agronomists and ecosystem modelers to characterize the quantity and quality of light conducive to plant growth and development. Spatial distribution of PAR in a greenhouse can be quite variable and diffuse throughout the day time photoperiod, especially at low sun angles in northern regions of the United States. Four colors of reflective plastic mulches (white, red, olive, and black) were evaluated for winter-time strawberry (Fragaria × ananassa Duch.) production based on their reflectance and transmittance properties in a double-polyethylene, plastic-glazed Quonset greenhouse inNebraska. The spectral properties …


Fabrication And Characterization Of Dna-Loaded Zein Nanospheres, Mary C. Regier, Jessica D. Taylor, Tyler Borcyk, Yiqi Yang, Angela K. Pannier Jan 2012

Fabrication And Characterization Of Dna-Loaded Zein Nanospheres, Mary C. Regier, Jessica D. Taylor, Tyler Borcyk, Yiqi Yang, Angela K. Pannier

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Background: Particulates incorporating DNA are promising vehicles for gene delivery, with the ability to protect DNA and provide for controlled, localized, and sustained release and transfection. Zein, a hydrophobic protein from corn, is biocompatible and has properties that make it a promising candidate material for particulate delivery, including its ability to form nanospheres through coacervation and its insolubility under physiological conditions, making it capable of sustained release of encapsulated compounds. Due to the promise of this natural biomaterial for drug delivery, the objective of this study was to formulate zein nanospheres encapsulating DNA as the therapeutic compound, and to …


Runoff Nutrient Loads As Affected By Residue Cover, Manure Application Rate, And Flow Rate, Chance Thayer, John E. Gilley, Lisa M. Durso, David B. Marx Jan 2012

Runoff Nutrient Loads As Affected By Residue Cover, Manure Application Rate, And Flow Rate, Chance Thayer, John E. Gilley, Lisa M. Durso, David B. Marx

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Manure is applied to cropland areas with varying surface cover to meet single‐year or multiple‐year crop nutrient requirements. The objectives of this field study were to: (1) examine runoff water quality characteristics following land application of manure to sites with and without wheat residue, (2) compare the water quality impacts of land application of manure to meet 0‐, 1‐, 2‐, 4‐, and 8‐year P‐based requirements for corn, and (3) evaluate the effects of varying runoff rates on runoff nutrient loads. Three 30‐min simulated rainfall events, separated by 24 h intervals, were applied at an intensity of 70 mm h‐1 …


Quantification And Heterogeneity Of Infiltration And Transport In Alluvial Floodplains, Derek M. Heeren, Garey A. Fox, Daniel E. Storm, Peter Q. Storm, Brian E. Haggard, Todd Halihan, Ronald B. Miller Jan 2012

Quantification And Heterogeneity Of Infiltration And Transport In Alluvial Floodplains, Derek M. Heeren, Garey A. Fox, Daniel E. Storm, Peter Q. Storm, Brian E. Haggard, Todd Halihan, Ronald B. Miller

Department of Agricultural and Biological Systems Engineering: Faculty Publications

In order to protect drinking water systems and aquatic ecosystems, all critical nutrient source areas and transport mechanisms need to be characterized. It is hypothesized that hydrologic heterogeneities (e.g., macropores and gravel outcrops) in the subsurface of floodplains play an integral role in impacting flow and contaminant transport between the soil surface and shallow alluvial aquifers which are intricately connected to streams. Infiltration is often assumed to be uniform at the field scale, but this neglects the high spatial variability common in anisotropic, heterogeneous alluvial floodplain soils. In the Ozark ecoregion, for example, the erosion of carbonate bedrock (primarily limestone) …


Berm Method For Quantification Of Infiltration And Leaching At The Plot Scale In High Conductivity Soils, Derek M. Heeren, Garey A. Fox, Daniel E. Storm Jan 2012

Berm Method For Quantification Of Infiltration And Leaching At The Plot Scale In High Conductivity Soils, Derek M. Heeren, Garey A. Fox, Daniel E. Storm

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Measuring infiltration and leaching at the plot scale is difficult, especially for high hydraulic conductivity soils. Infiltration rate has been indirectly calculated at the plot scale by comparing surface runoff to rainfall. Direct measurement of infiltration and leaching beyond the point scale is typically limited to locations where land forming has been performed, e.g. infiltration ponds and fields with basin irrigation. The standard method for field measurement of infiltration is a double ring infiltrometer, which is limited in size (typically 30 cm diameter). In this research, a new method is proposed that uses a temporary berm constructed of a water …


Field Scale Modeling To Estimate Phosphorus And Sediment Load Reductions Using A Newly Developed Graphical User Interface For Soil And Water Assessment Tool, Aaron R. Mittelstet, Erin R. Daly, Daniel E. Storm, Michael J. White, Greg A. Kloxin Jan 2012

Field Scale Modeling To Estimate Phosphorus And Sediment Load Reductions Using A Newly Developed Graphical User Interface For Soil And Water Assessment Tool, Aaron R. Mittelstet, Erin R. Daly, Daniel E. Storm, Michael J. White, Greg A. Kloxin

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Streams throughout the North Canadian River watershed in northwest Oklahoma, USA have elevated levels of nutrients and sediment. Soil and Water Assessment Tool (SWAT) was used to identify areas that likely contributed disproportionate amounts of Phosphorus (P) and sediment to Lake Overholser, the receiving reservoir at the watershed outlet. These sites were then targeted by the Oklahoma Conservation Commission (OCC) to implement conservation practices, such as conservation tillage and pasture planting as part of a US Environmental Protection Agency Section 319(h) project. Conservation practices were implemented on 238 fields. The objective of this project was to evaluate conservation practice effectiveness …


Whose Water Is It Anyway? Comparing The Water Rights Frameworks Of Arkansas, Oklahoma, Texas, New Mexico, Georgia, Alabama, And Florida, M. D. Smolen, Aaron R. Mittelstet, Bekki Harjo Jan 2012

Whose Water Is It Anyway? Comparing The Water Rights Frameworks Of Arkansas, Oklahoma, Texas, New Mexico, Georgia, Alabama, And Florida, M. D. Smolen, Aaron R. Mittelstet, Bekki Harjo

Department of Agricultural and Biological Systems Engineering: Faculty Publications

In most states surface waters, (streams, lakes, and coastal waters) are owned by the public. On the other hand, ground water may be privately or publicly owned. Because all waters are linked through the hydrologic cycle, and the hydrologic cycle is not confined within any geographic or political boundary, the question of ownership is generally replaced by one of who has the right to manage, divert, use, or sell the water.


Comparison Of 2-Way Versus Metered 3-Way Boom Shut-Off Valves For Automatic Section Control On Agricultural Sprayers, Ajay Sharda, Joe D. Luck, John P. Fulton, Timothy P. Mcdonald, Scott A. Shearer, Daniel K. Mullenix Jan 2012

Comparison Of 2-Way Versus Metered 3-Way Boom Shut-Off Valves For Automatic Section Control On Agricultural Sprayers, Ajay Sharda, Joe D. Luck, John P. Fulton, Timothy P. Mcdonald, Scott A. Shearer, Daniel K. Mullenix

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Modern spray rate controllers along with technologies such as automatic section control (ASC) provide benefits such as overlap reduction on agricultural sprayers. However, product (liquid) dynamics within the boom plumbing affect off-rate errors and application uniformity during rate changes and ASC actuation. Therefore, this study was conducted to compare nozzle flow stability and uniformity across the boom when using two different boom shut-off valves (2-way and metered 3-way) on an 18.3-m sprayer boom. Pressure transducers were mounted at 1) the boom manifold, 2) randomly at 12 nozzle bodies across the spray boom, and 3) upstream and downstream of the flow …


Selecting Sprinkler Packages For Center Pivots, Derrel L. Martin, William L. Kranz, Allen L. Thompson, Hong Liang Jan 2012

Selecting Sprinkler Packages For Center Pivots, Derrel L. Martin, William L. Kranz, Allen L. Thompson, Hong Liang

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Center pivots are the primary method of irrigation across the U.S. Great Plains. Center-pivot irrigation is also the fastest growing method of irrigation in the U.S. and around the world. Pivots have the potential to be very efficient and uniform if sprinkler devices are properly selected for local field conditions. New water application devices provide for selection that minimizes runoff and controls droplet sizes to reduce evaporation and drift losses. We present updates to models for computing runoff potential based on characteristics of sprinkler devices and soil textural classes. A dimensionless solution to the Green-Ampt infiltration method for center pivots …


Sensitivity Of Grass- And Alfalfa-Reference Evapotranspiration To Weather Station Sensor Accuracy, Dana O. Porter, Prasanna H. Gowda, Thomas H. Marek, Terry A. Howell, Jerry Moorhead, Suat Irmak Jan 2012

Sensitivity Of Grass- And Alfalfa-Reference Evapotranspiration To Weather Station Sensor Accuracy, Dana O. Porter, Prasanna H. Gowda, Thomas H. Marek, Terry A. Howell, Jerry Moorhead, Suat Irmak

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A sensitivity analysis was conducted to determine the relative effects of measurement errors in climate data input parameters on the accuracy of calculated reference crop evapotranspiration (ET) using the ASCE-EWRI Standardized Reference ET Equation. Data for the period of 1995 to 2008 from an automated weather station located at the USDA-ARS Conservation and Production Research Laboratory at Bushland, Texas were used for the analysis. Results

indicated that grass (ETos) and alfalfa (ETrs) reference crop ET were most sensitive to measurement errors in wind speed and air temperature followed by incoming shortwave (solar) radiation, and that data …


Evaluation Of A Rhodamine-Wt Dye/Glycerin Mixture As A Tracer For Testing Direct Injection Systems For Agricultural Sprayers, Joe D. Luck, Scott A. Shearer, Brian D. Luck, Fred A. Payne Jan 2012

Evaluation Of A Rhodamine-Wt Dye/Glycerin Mixture As A Tracer For Testing Direct Injection Systems For Agricultural Sprayers, Joe D. Luck, Scott A. Shearer, Brian D. Luck, Fred A. Payne

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The purpose of this study was to provide valuable insight regarding the use of Rhodamine WT (red) dye as a tracer for evaluating injected concentrations. More specifically, the effects of mixing the dye with glycerin to simulate the viscosity of a pesticide (e.g., glyphosate) or injecting the dye/glycerin mixture into deionized (DI) versus tap water on developing appropriate calibration equations were evaluated. Test results indicated that mixing the dye in a solution of glycerin and DI water significantly affected absorbance measurements compared to the dye mixed solely in DI water. The error in estimating absorbance was 7.4% between the two …


Swat: Model Use, Calibration, And Validation, Jeffrey G. Arnold, Daniel N. Moriasi, Philip W. Gassman, Karim C. Abbaspour, Michael J. White, Raghavan Srinivasan, Chinnasamy Santhi, Daren Harmel, Ann Van Griensven, Michael W. Van Liew, Narayanan Kannan, Manoj K. Jha Jan 2012

Swat: Model Use, Calibration, And Validation, Jeffrey G. Arnold, Daniel N. Moriasi, Philip W. Gassman, Karim C. Abbaspour, Michael J. White, Raghavan Srinivasan, Chinnasamy Santhi, Daren Harmel, Ann Van Griensven, Michael W. Van Liew, Narayanan Kannan, Manoj K. Jha

Department of Agricultural and Biological Systems Engineering: Faculty Publications

SWAT (Soil and Water Assessment Tool) is a comprehensive, semi-distributed river basin model that requires a large number of input parameters, which complicates model parameterization and calibration. Several calibration techniques have been developed for SWAT, including manual calibration procedures and automated procedures using the shuffled complex evolution method and other common methods. In addition, SWAT-CUP was recently developed and provides a decision-making framework that incorporates a semi-automated approach (SUFI2) using both manual and automated calibration and incorporating sensitivity and uncertainty analysis. In SWAT-CUP, users can manually adjust parameters and ranges iteratively between autocalibration runs. Parameter sensitivity analysis helps focus the …


Soil Water Extraction Patterns And Crop, Irrigation, And Evapotranspiration Water Use Efficiency Of Maize Under Full And Limited Irrigation And Rainfed Settings, Koffi Djaman, Suat Irmak Jan 2012

Soil Water Extraction Patterns And Crop, Irrigation, And Evapotranspiration Water Use Efficiency Of Maize Under Full And Limited Irrigation And Rainfed Settings, Koffi Djaman, Suat Irmak

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The effects of full and limited irrigation and rainfed maize production practices on soil water extraction and water use efficiencies were investigated in 2009 and 2010 under center-pivot irrigation near Clay Center, Nebraska. Four irrigation regimes (fully irrigated treatment (FIT), 75% FIT, 60% FIT, and 50% FIT) and a rainfed treatment were implemented. The crop water use efficiency (CWUE, or crop water productivity), irrigation water use efficiency (IWUE), and evapotranspiration water use efficiency (ETWUE) were used to evaluate the water productivity performance of each

treatment. The seasonal rainfall amounts in 2009 and 2010, respectively, were 426 mm (18% below normal) …


Large-Scale On-Farm Implementation Of Soil Moisture-Based Irrigation Management Strategies For Increasing Maize Water Productivity, Suat Irmak, Michael J. Burgert, Haishun Yang, Kenneth G. Cassman, Daniel T. Walters, William R. Rathje, Jose O. Payero, Patricio Grassini, Mark S. Kuzila, Kelly J. Brunkhorst, Dean E. Eisenhauer, William L. Kranz, Brandy Vandewalle, Jennifer M. Rees, Gary L. Zoubek, Charles A. Shapiro, Gregory J. Teichmeier Jan 2012

Large-Scale On-Farm Implementation Of Soil Moisture-Based Irrigation Management Strategies For Increasing Maize Water Productivity, Suat Irmak, Michael J. Burgert, Haishun Yang, Kenneth G. Cassman, Daniel T. Walters, William R. Rathje, Jose O. Payero, Patricio Grassini, Mark S. Kuzila, Kelly J. Brunkhorst, Dean E. Eisenhauer, William L. Kranz, Brandy Vandewalle, Jennifer M. Rees, Gary L. Zoubek, Charles A. Shapiro, Gregory J. Teichmeier

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Irrigated maize is produced on about 3.5 Mha in the U.S. Great Plains and western Corn Belt. Most irrigation water comes from groundwater. Persistent drought and increased competition for water resources threaten long-term viability of groundwater resources, which motivated our research to develop strategies to increase water productivity without noticeable reduction in maize yield. Results from previous research at the University of Nebraska-Lincoln (UNL) experiment stations in 2005 and 2006 found that it was possible to substantially reduce irrigation amounts and increase irrigation water use efficiency (IWUE) and crop water use efficiency (CWUE) (or crop water productivity) with little or …


Evaporative Losses From A Common Reed-Dominated Peachleaf Willow And Cottonwood Riparian Plant Community, Isa Kabenge, Suat Irmak Jan 2012

Evaporative Losses From A Common Reed-Dominated Peachleaf Willow And Cottonwood Riparian Plant Community, Isa Kabenge, Suat Irmak

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Our study is one of the first to integrate and apply within-canopy radiation physics parameters and scaling-up leaf-level stomatal resistace (rL) to canopy resistance (rc) approach to quantify hourly transpiration (TRP) rates of individual riparian plant species—common reed (Phragmites australis), peachleaf willow (Salix amygdaloides), and cottonwood (Populus deltoides)— in a mixed riparian plant community in the Platte River Basin in central Nebraska. Two experimental years (2009 and 2010) were contrasted by warmer air temperature and presence of flood water in 2010. The seasonal average rc values for common reed, …


P95. In Vivo Loads In The Cervical Spine: A Preliminary Investigation Using A Force-Sensing Implant, Rebecca A. Wachs, Mary Beth M. Grabowsky, Joseph C. Glennon, Eric H. Ledet Jan 2012

P95. In Vivo Loads In The Cervical Spine: A Preliminary Investigation Using A Force-Sensing Implant, Rebecca A. Wachs, Mary Beth M. Grabowsky, Joseph C. Glennon, Eric H. Ledet

Department of Agricultural and Biological Systems Engineering: Faculty Publications

BACKGROUND CONTEXT: It is estimated that up to 80% of the general population will experience at least one significant bout of low back pain in their lifetime. The leading known cause of low back pain is degenerative disc disease (DDD). Many established risk factors for low back pain and DDD are mechanical in nature and are often related to occupational activities, such as poor posture and frequent/heavy lifting. Altered mechanical loading in the spine has been shown to be a potential stimulus for disc degeneration. However, a link between occupational/environmental factors and intervertebral loading has never been demonstrated in vivo. …