Bioresource and Agricultural Engineering Commons^™

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

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

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 …

Hydraulic Conditions Required To Not Move Unconsolidated Surface Material Located Within Feedlots, John E. Gilley, Gregory D. Boone, David B. Marx

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Beef cattle feedlots contain unconsolidated surface material that accumulates within feedlot pens during a feeding cycle. Runoff from feedlot surfaces is diverted into settling basins. The storage capacity of the settling basins will be substantially reduced if large quantities of solid material are transported in runoff from the feedlot surfaces. The objective of this study was to identify the hydraulic conditions that will not move unconsolidated surface material located within feedlots in order to minimize sediment transport. Selected sizes and a composite sample of unconsolidated surface material were placed within 0.75 m wide by 4.0 m long metal frames. Flow …

Two-Dimensional Blood Flow Velocity Estimation Using Ultrasound Speckle Pattern Dependence On Scan Direction And A-Line Acquisition Velocity, Tiantian Xu, Gregory R. Bashford

Department of Agricultural and Biological Systems Engineering: Faculty Publications

We have previously investigated the change of apparent lateral speckle size caused by the direction and spatial rate of scanner A-line acquisition (scan velocity). An algorithm which measures the lateral component of blood flow velocity was developed based on the increase in speckle size resulting from relative motion between moving scatterers and the scan velocity. In this paper, the change of the apparent dominant angle of the speckle pattern in a straight vessel was investigated and a new method of two-dimensional blood flow velocity estimation is introduced. Different scan velocities were used for data acquisition from blood flow traveling at …

Unique Replogle Flume Installations At The Truckee-Carson Irrigation District, Stuart Styles, Brandon Downing, Walter Winder

BioResource and Agricultural Engineering

The Water Measurement Program (WMP) for Truckee-Carson Irrigation District (TCID) began in 1997, when the Irrigation Training and Research Center (ITRC) of Cal Poly State University was asked to develop a volumetric measurement plan for TCID, funded by the U.S. Bureau of Reclamation, Mid-Pacific Region. This program was intended to develop and install reasonably accurate turnout delivery measurement techniques in the district. As part of the WMP, TCID was required to install a number of new open-channel measurement devices. TCID opted for the Replogle flume as its primary flow measurement device using the newly developed WinFlume computer program.

A few …

Vineyard Drip Irrigation Design, Roman Ferro

BioResource and Agricultural Engineering

The goal of this project is to develop a cost and water efficient drip irrigation system. This irrigation system will deliver irrigation needs to a future 2.5 acre vineyard owned by the Jaqua family. The design accounts for the specifics of the field such as soil type, slope, crop water requirement, etc. A detailed design was created which includes part specifications, cost estimate and field map.

Design And Evaluation Of An Irrigation System For Meyer Lemons, Anthony Atchley

BioResource and Agricultural Engineering

This senior project discusses the design and implementation procedures for an irrigation system for Meyer lemons. The irrigation system is designed from an economical standpoint incorporating limitations set by the ranch manager such as the use of existing pipe lines and emitter selection preference. Within this project there are the steps taken to ensure a healthy crop utilizing the data and advice collected from other fields and their managers in the same area.

The entire field is run as a single set with two manifolds to supply the Western and Eastern ends of the field. A total of 555 trees …

Modeling Biofuel Expansion Effects On Land Use Change Dynamics, Ethan Warner, Daniel Inman, Benjamin Kunstman, Brian Bush, Laura Vimmerstedt, Steve Peterson

Dartmouth Scholarship

Increasing demand for crop-based biofuels, in addition to other human drivers of land use, induces direct and indirect land use changes (LUC). Our system dynamics tool is intended to complement existing LUC modeling approaches and to improve the understanding of global LUC drivers and dynamics by allowing examination of global LUC under diverse scenarios and varying model assumptions. We report on a small subset of such analyses. This model provides insights into the drivers and dynamic interactions of LUC (e.g., dietary choices and biofuel policy) and is not intended to assert improvement in numerical results relative to other works.

Demand …

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.

Pressure Regulating Valve Pilot Characteristics - 2-Way Vs. 3-Way Pilots, Charles M. Burt, Kyle Feist

BioResource and Agricultural Engineering

Pressure regulation valves, with 3” – 6” diameters, are commonly found at the entrance to agricultural irrigation blocks and manifolds. These valves are typical of a “hydraulic” design, in which a chamber above a flexible disc/diaphragm is filled or emptied. As the chamber is filled or emptied, the irrigation water passes through a smaller or larger orifice, and the pressure downstream of the valve is lowered, increased, or maintained at a constant target pressure. The flow in/out of the chamber is controlled by a small “pilot valve”. The characteristics of these pilot valves are discussed here, in general terms. Of …

Design And Use Of An Adjustable Clearance Flailing Knife Biomass Shredder To Mechanically Increase Particle Surface Area, Shawn Gregory Ehlers

Open Access Theses

A flailing knife shredder was designed and tested as an alternative to a hammermill for processing biomass. The machine was comprised of two cylinders with four rungs, each with five free-swinging blades. Each of the two cylinders had adjustable clearance hoods and variable speed drives. Energy usage, output characteristics and device capacities were compared with corn stover processed at moisture contents (MC) of 10%, 35% and 50% wet basis (WB). The hammermill produced a more uniform particle size distribution in comparison to the shredder. Accessibility, indicated by conductivity index, to plant constituents, revealed that the method of treatment was not-significant …

Techno-Economic And Fluid Dynamics Analysis For Growing Microalgae With The Intent Of Producing Biofuel Using A System Model, Leah R. Raffaeli

Electronic Theses and Dissertations

Techno-economic and systems studies on microalgal growth scenarios to date are abbreviated and missing a number of important variables. By including these variables in a detailed model integrating biology, chemistry, engineering, and financial aspects, a more defined systems analysis is possible. Through optimizing the model productivity based on the resulting net profit, the system analysis results in a more accurate assessment of environmental and economic sustainability of specific algal growth scenarios. Photobioreactor algal growth scenario optimization in the system model has resulted in realistic engineering design requirements based on algal growth requirements and fluid dynamics analysis. Results show feasibility for …

The John Zink Hamworthy Combustion Handbook, 2nd Edition, Volume 1: Fundamentals, Edited By Charles E. Baukal, Jr., Crc Press, Boca Raton, Fl, 2013., Payal A. Chandan

Coal Combustion and Gasification Products Journal Archive

No abstract provided.

Pipeline And Canal Downstream Control System For Recirculation - Patterson Id Case Study, John Sweigard, Charles M. Burt, Peter Rietkerk

BioResource and Agricultural Engineering

Patterson ID in Central California has five long, along-the-contour lateral canals that flow northward from a main canal. The main canal operates on downstream control, providing excellent flexibility to heads of the laterals. The lateral canals operate with manual upstream control and have little storage. The classic tail-ender problem existed; spill from the tail end was necessary to avoid under-supplying tail-end customers.

To eliminate the spill and to provide better flexibility, a system was designed and constructed to tie the ends of the five laterals together with pipes and pumps, with one central regulating reservoir. The automatic control system allows …

Structure And Properties Of Cocoons And Silk Fibers Produced By Attacus Atlas, Narendra Reddy, Yi Zhao, Yiqi Yang

Department of Textiles, Merchandising and Fashion Design: Faculty Publications

Silk fibers in the three layers of Attacus atlas (A. atlas) cocoons have morphological structure and tensile properties similar to that of Bombyx mori silk. Attempts are being made to produce silk for commercial applications from cocoons of relatively unknown wild insects due to the unique properties of the fibers and as a source of income and employment. In this research, A. atlas cocoons were used to study the chemical composition, morphology, physical structure and tensile properties of the silk fibers in the cocoons and ability of the fibers to support the attachment and proliferation of mouse fibroblast cells. It …

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

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

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Hourly evapotranspiration (ET) crop coefficients (K_c) 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 K_c values for soybean. In addition, locally developed K_c 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 (ET_a) 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

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)-r_s 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 r_s, 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

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 (ET_a) 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

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, …