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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 …

Using Rapid Geomorphic Assessments To Assess Streambank Stability In Oklahoma Ozark Streams, Derek M. Heeren, Aaron R. Mittelstet, Garey A. Fox, Daniel E. Storm, Abdulsahib T. Al-Madhhachi, Taber L. Midgley, Ashley F. Stringer, Kevin B. Stunkel, Ron D. Tejral

Department of Biological Systems Engineering: Papers and Publications

High streambank erosion and failure rates on streams in the Ozark ecoregion of Oklahoma may be attributed to land use change and degradation of riparian areas. Numerous benefits may be achieved from streambank stabilization, but methods are needed to determine the most critical reaches for investing limited funds. Rapid geomorphic assessments (RGAs) have been used to aid in prioritizing stream reaches. This research (1) applied an existing RGA, the channel stability index (CSI), on several reaches along the Barren Fork Creek and Spavinaw Creek, and (2) modified the existing RGA to create an ecoregion-specific RGA called the Oklahoma Ozark streambank …

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 …}

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 Biological Systems Engineering: Papers and 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 …}

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 …

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 …