Engineering Commons^™

A 3-D Computational Fluid Dynamics Model For Forced Air Cooling Of Eggs Placed In Trays, Vikas Kumar, Ai Pheeng Wee, Sohan Birla, Jeyamkondan Subbiah, Harshanardhan Thippareddi

Department of Biological Systems Engineering: Papers and Publications

Shell eggs must be cooled quickly after laying for controlling Salmonella Enteritidis (SE) growth. To fulfill a research need identified by Food Safety and Inspection Service (FSIS), a 3-D Computational Fluid Dynamics (CFD) model was developed to predict the temperature of eggs placed on a tray (6 rows × 5 columns) under forced air cooling. The continuity, momentum, and energy equations were solved along with standard k-ε turbulence model using PHOENICS software. The model was validated by conducting experiments in a wind tunnel at various air temperatures (7–11 °C) and velocities (0.3– 0.7 m/s). Root mean square error for predicting …

The Biological Systems Engineering Program In Nebraska 1895-2011, William Splinter

Department of Biological Systems Engineering: Papers and Publications

4. Preface: How Mechanization Has Impacted Food Production THE PIONEERS WHO ESTABLISHED THIS DEPARTMENT 8 Oscar Van Pelt Stout 10 Charles Russ Richards 12 J. Brownlee Davidson 14 Leon W. Chase FORMER FACULTY AND THEIR CONTRIBUTIONS 18 Laurence Froyd Seaton 20 Ivan D.Wood 22 Oscar W. Sjogren 23 Chauncey W. Smith 25 Elmer E. Brackett 27 Claud Kedzie Shedd 29 Ruby M. Loper 31 Lester F. Larsen 33 Lloyd W. Hurlbut 36 Rollin Schnieder 39 Howard D. Wittmuss 41 Deon Axthelm 46 Paul. E. Fischbach 48 Stuart O. Nelson 51 Kenneth von Bargen 56 John R. Davis 58 Robert W. …

Evaluation Of The Impact Of Surface Residue Cover On Single And Dual Crop Coefficient For Estimating Soybean Actual Evapotranspiration, Lameck O. Odhiambo, Suat Irmak

Department of Biological Systems Engineering: Papers and Publications

Single and dual crop coefficient methods are used in conjunction with grass reference evapotranspiration (ET_o) to estimate actual crop evapotranspiration (ET_c). However, the impact of soil surface residue cover on the accuracy of ET_c estimated with these methods is not well understood. The objective of this study is to evaluate and compare the accuracy of the FAO-56 single crop coefficient (single-K_c) and dual crop coefficient (dual-K_c) methods for estimating soybean [Glycine max (L.) Merr.] ET_c in a partially residue covered field. The study was conducted …

Subsurface Phosphorus Transport And Scale Dependent Phosphorus Leaching In Alluvial Floodplains, Derek Michael Heeren

Department of Biological Systems Engineering: Papers and Publications

Increased nutrient loads have resulted in several adverse impacts on surface water quality, including excessive algal growth, fish kills, and drinking water taste and odor issues across the United States and especially in the Ozark ecoregion of northeastern Oklahoma and northwestern Arkansas. Nitrogen is a concern, but phosphorus (P) is generally considered the limiting nutrient in most surface water systems. Scientists and engineers need to identify critical nutrient source areas and transport mechanisms within a catchment in order to cost effectively protect and enhance drinking water systems, recreation activities, and aquatic ecosystems. While surface runoff is considered to be the …

Global Estimation Of Evapotranspiration Using A Leaf Area Index-Based Surface Energy And Water Balance Model, H. Yan, S.Q. Wang, David P. Billesbach, Walter Oechel, J.H. Zhang, Tilden Meyers, Ta. Martin, Roser Matamala, Dennis D. Baldocchi, G. Bohrer, D. Dragoni, R. Scott

Department of Biological Systems Engineering: Papers and Publications

Studies of global hydrologic cycles, carbon cycles and climate change are greatly facilitated when global estimates of evapotranspiration (E) are available. We have developed an air-relative-humidity-based two-source (ARTS) E model that simulates the surface energy balance, soil water balance, and environmental constraints on E. It uses remotely sensed leaf area index (L_ai) and surface meteorological data to estimate E by: 1) introducing a simple biophysical model for canopy conductance (G_c), defined as a constant maximum stomatal conductance g_smax of 12.2mm s⁻¹multiplied by air relative humidity (R_{h …}

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 Biological Systems Engineering: Papers and 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

Department of Biological Systems Engineering: Papers and 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.

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 Biological Systems Engineering: Papers and 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 (ET_os) and alfalfa (ET_rs) reference crop ET were most sensitive to measurement errors in wind speed and air temperature followed by incoming shortwave (solar) radiation, and that data …

Field Performance Evaluation Of A Ventilation System: A Swine Case Study, Jay D. Harmon, Michael C. Brumm, Larry D. Jacobson, Stephen H. Pohl, David R. Stender, Richard R. Stowell

Department of Biological Systems Engineering: Papers and Publications

Swine finishing facility ventilation has become relatively complex and is often mismanaged as a system. One of the few ways to truly understand these systems is to spend time systematically going through the many components of the building and how they work as a system. To learn to help producers better, a team of university Extension specialists that included agricultural engineers and animal scientists spent an extended period carefully documenting conditions in a deep‐pit swine finishing building with two 1,000‐head rooms. Exhaust fans connected to the manure pit and wall fans were operated at various stages as a negative‐pressure ventilation …

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 Biological Systems Engineering: Papers and 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

Department of Biological Systems Engineering: Papers and 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 …

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 Biological Systems Engineering: Papers and 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

Department of Biological Systems Engineering: Papers and Publications

Our study is one of the first to integrate and apply within-canopy radiation physics parameters and scaling-up leaf-level stomatal resistace (r_L) to canopy resistance (r_c) 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 r_c 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

Department of Biological Systems Engineering: Papers and 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. …