Bioresource and Agricultural Engineering Commons^™

Grass Referenced Based Vegetation Coefficients For Estimating Evapostranspiration For A Variery Of Natural Vegetation, Daniel J. Howes, Mariana Pasquet

BioResource and Agricultural Engineering

In arid and semi-arid regions, evapotranspiration from vegetation results in the significant utilization of available water. Accurate estimates of evapotranspiration are required for surface and subsurface hydrologic evaluations as well as irrigation district water balance studies. A significant amount of transferable information exists for irrigated agricultural crops through past and current research in the form of grass or alfalfa reference based crop coefficients (Kc) and basal crop coefficients (Kcb). However, transferable evapotranspiration information on natural vegetation is limited. Much of the work was conducted in the early to mid-1900’s and is presented as actual evapotranspiration from the vegetation at the …

Adaptive Targeting: Engaging Farmers To Assess Perceptions And Improve Watershed Modeling, Optimization, And Adoption Of Agricultural Conservation Practices, Margaret Mccahon Kalcic

Open Access Dissertations

Targeting agricultural conservation practices to farmland that has the greatest impact on surface water quality has received wide support from scientists and watershed managers. The targeting approach has, however, been politically contentious as many believe farmers will oppose the approach on grounds such as privacy invasion and unfair distribution of government incentives. Targeting conservation practices using complex optimization models has become common in the scientific community, and yet targeted results are underutilized in practice because of difficulties such as knowledge transfer and absence of a political framework for their use. For targeting to be successful, it must be politically supported …

Using X-Ray Imaging Techniques To Determine Density Of Foods, Shivangi Mohan Kelkar

Open Access Dissertations

Density depends on the experimental technique and structural properties of food. True, apparent and bulk are different types of densities. For porous foods such as baked food products and complex food systems, accurate measurement of density is challenging. Empirical correlations dependent on composition and temperature exist to calculate true density. Thus if composition and apparent density are known, porosity can be calculated, porosity = [1 - (apparent density/ true density)]. Various non-destructive diagnostic tools have been employed to study food microstructure. Among these, computed tomography (CT) and digital radiography (DR) utilizing x-ray imaging showed greater capability for evaluation of food …

Ozonation Systems As A Non-Chemical Alternative For Stored Grain Protection, Carlos A. Campabadal

Open Access Dissertations

The use of ozone as a non-chemical alternative in stored grain protection was studied by conducting scale-up demonstrations using a fixed bed ozonation system and developing a semi-continuous counterflow and a continuous flow ozonation treatment system. The objectives of this research were to determine the efficacy of ozonation to control insect pests without affecting end-use quality; to prove the concept of the semi-continuous counterflow ozonation system to ozonate grain at a faster rate and quantify its effect on mold growth reduction; to evaluate the efficacy of a modified screw conveyor for pest control by treating grain in a continuous-flow ozonation …

Advanced Control Strategies For Mobile Hydraulic Applications, Davide Cristofori

Open Access Dissertations

Mobile hydraulic machines are affected by numerous undesired dynamics, mainly discontinuous motion and vibrations. Over the years, many methods have been developed to limit the extent of those undesired dynamics and improve controllability and safety of operation of the machine. However, in most of the cases, today's methods do not significantly differ from those developed in a time when electronic controllers were slower and less reliable than they are today.

This dissertation addresses this aspect and presents a unique control method designed to be applicable to all mobile hydraulic machines controlled by proportional directional valves. In particular, the proposed control …

Direct And Indirect Greenhouse Gas Emissions From Biomass Storage: Implications For Life Cycle Assessment Of Biofuels, Isaac Robert Emery

Open Access Dissertations

Ethanol and other biofuels from cellulosic feedstocks are currently the most promising candidates to replace a large fraction of gasoline consumption in the United States and reduce greenhouse gas emissions. Gaps in current approaches to estimating the net greenhouse gas emissions from second-generation biofuels may lead to underestimation of the carbon intensity of these fuels. Current life cycle assessment models of biofuels do not sufficiently account for biomass losses and emissions associated with the harvest and storage of biomass feedstocks, which can require additional fuel and materials use on the farm as well as reducing the effective yield of a …

Yield And Crop Water Use Efficiency Response Of Drought-Tolerant And Conventional Maize Hybrids Under Different Irrigation Regimes, Plant Populations And Climate Gradients, Ali T. Mohammed

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

Water scarcity in many regions of the world, including Nebraska, is imposing increasing pressure on water demands in agriculture to meet future food and fiber demand of rapidly growing world populations. One of the viable alternatives to counter this challenge is cultivating new drought-tolerant hybrids/varieties/cultivars. Recently, new drought-tolerant maize (Zea mays L.) hybrids have been developed by major seed companies. However, it is essential to evaluate the performance of these hybrids, in terms of grain yield and crop water use (actual evapotranspiration) in various climatic and soil conditions under large production settings. Research was conducted at four locations across the …

Enzymatic Hydrolysis Of Biomass At High-Solids Loadings – A Review, Alicia A. Modenbach, Sue E. Nokes

Biosystems and Agricultural Engineering Faculty Publications

Enzymatic hydrolysis is the unit operation in the lignocellulose conversion process that utilizes enzymes to depolymerize lignocellulosic biomass. The saccharide components released are the feedstock for fermentation. When performed at high-solids loadings (≥ 15% solids, w/w), enzymatic hydrolysis potentially offers many advantages over conversions performed at low- or moderate-solids loadings, including increased sugar and ethanol concentrations and decreased capital and operating costs.

The goal of this review is to provide a consolidated source of information on studies using high-solids loadings in enzymatic hydrolysis. Included in this review is a brief discussion of the limitations, such as a lack of available …

Juxtaposing Nasa’S Aeronet Aod With Carb Pm Data Over The San Joaquin Valley To Facilitate Multi-Angle Imaging Spectroradiometer (Misr) Pm Pollution Research, John Kanemoto

STAR Program Research Presentations

Airborne particulate matter (PM) has been shown to increase the risk for asthma, chronic bronchitis, cardiopulmonary complications, and respiratory cell membrane damage/infection/leakage. PM levels are currently analyzed from two perspectives: stationary land-based monitoring (LBM) sites and total Aerosol Optical Depth (AOD) atmospheric column measurements. Both perspectives often leave miles of space between measuring locations and will have a continually increasing cost from introducing/maintaining sites. The Multi-angle Imaging SpectroRadiometer (MISR) satellite team hopes to begin investigating/archiving PM levels comprehensively via inputting MISR AOD measurements into a function/model which predicts the amount of ground level PM.

In the future, multivariable spatial correlations …

Low-Pressure Testing: Pressure Regulating Valves, Charles M. Burt, Kyle Feist

BioResource and Agricultural Engineering

ITRC tested performance characteristics of pressure regulating valves from a variety of manufacturers. The purpose of the testing was to evaluate the ability of different models of valves to regulate the pressure in a low-pressure system. The testing concentrated on three specific valve performance characteristics: minimal variance from the target downstream pressure caused by changes in flow rate or inlet pressure; minimal hysteresis in outlet pressures; minimal pressure loss (at low inlet pressures) across the valve.

Characterization And Quantification Of Monomers, Oligomers, And By-Products From Switchgrass Hemicelluloses During Biomass Pretreatment, Kris Allan Bunnell

Graduate Theses and Dissertations

Production of fuels and chemicals from biomass is contingent upon economical release of carbohydrates from biomass. Carbohydrates can then be used for production of bio-based products using a biochemical conversion process. Pretreatment, the first step of the biochemical conversion process, has been suggested to be the most costly step of the conversion process. Thus, better understanding the behavior of biomass during pretreatment is imperative for an economically viable production of biofuels and chemicals. Elucidating the physicochemical properties of biomass and developing an understanding the depolymerization patterns of biomass during pretreatment will help progress towards this goal.

In this study, July- …

Evaluation Of Broiler Litter Heat Production During Windrowing & Nitrogen Based Gas Emission Mitigation Using Biofilter, Min Lei

Graduate Theses and Dissertations

Ammonia emission from animal feeding operations (AFOs) has negative effects on environment and animals' health. Thus measuring and mitigating ammonia emission from AFOs is important for environmental protection. In chapter I, different ammonia measurements were discussed and a mitigation technology- biofilter was represented.

In-house windrowing of built-up litter has been used by broiler producers to reduce pathogen loads and rejuvenate litter for the next flock. When litter is piled up for an extended period during downtime, heat generated by the litter pile can become a substantial heat source due to the metabolism of microorganisms. In chapter II, heat production rates …

Low-Pressure Testing: Microirrigation Emitters, Charles M. Burt, Kyle Feist

BioResource and Agricultural Engineering

ITRC tested 28 different pressure-compensating (PC) models of microirrigation emitting devices from a total of nine manufacturers in order to compare independent laboratory testing with manufacturer specifications. It is the intention of this report to investigate the ability of currently marketed products to operate in a truly low pressure irrigation system where energy inputs, in the form of pump discharge requirements, can be minimized.

The Use Of Co-Culturing In Solid Substrate Cultivation And Possible Solutions To Scientific Challenges, Wanying Yao, Sue E. Nokes

Biosystems and Agricultural Engineering Faculty Publications

This perspective systematically summarizes the use of solid substrate co‐cultures in agriculture, food, plant, and industrial biotechnology applications. The summarization is organized by organism, i.e. fungus, bacteria, yeast and then co‐cultivation of either two or three organisms. Generally, in solid substrate co‐culture, the organisms synergistically penetrate and degrade the solid substrate, thereby increasing product yield and productivity over a monoculture. Efforts to increase co‐culture performance include optimizing process parameters (pH, temperature, moisture, and oxygen demand) and defining the acceptable types of substrate. Scientific challenges exist in understanding the interactions between microbial stains, such as viability, suite of products, and bio‐transformations. …

Horizontal Pressures In Cylindrical Metal Silos And Comparison With Different International Standards, José W. B. Do Nascimiento, José P. Lopes Neto, Michael D. Montross

Biosystems and Agricultural Engineering Faculty Publications

The focus of this research was to evaluate the horizontal pressures on a cylindrical metal silo of corrugated walls and flat bottom with 1.82m diameter and 5.4m high, and to compare the values with those obtained theoretically by the ISO 11697, EP 433 and AS 3774 standards. The silo was symmetrically filled and constant speed with wheat cv. soft red for two different height/diameter ratios (H/D) and was unloaded through three orifices with a diameter of 71.6mm, one concentric and two eccentrics. Horizontal pressures were measured on the walls of the silo at three positions using hydraulic type pressure cells. …

Zein: Novel Natural Polymer For Nanoparticle- And Film-Mediated Gene Delivery, Jessica D. Taylor

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

Gene delivery, the introduction of DNA into cells, is applicable to gene therapy, DNA vaccination, functional genomics and diagnostics, tissue engineering, and drug-eluting medical devices. Particulates incorporating DNA are promising vehicles for gene delivery and overcome some of the barriers that hinder successful gene transfer, with the ability to protect DNA and provide for controlled, localized, and sustained release and transfection. Furthermore, innovative new gene delivery strategies that incorporate DNA particulates or complexes within films or coatings for devices and scaffolds could further provide for controlled and sustained transfection at the site of implant. Zein, a hydrophobic protein from corn, …

Nanowell-Trapped Charged Ligand-Bearing Nanoparticle Surfaces – A Novel Method Of Enhancing Flow-Resistant Cell Adhesion, Phat L. Tran, Jessica R. Gamboa, Katherine E. Mccracken, Mark R. Riley, Marvin J. Slepian, Jeong-Yeal Yoon

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Assuring cell adhesion to an underlying biomaterial surface is vital in implant device design and tissue engineering, particularly under circumstances where cells are subjected to potential detachment from overriding fl uid fl ow. Cell–substrate adhesion is a highly regulated process involving the interplay of mechanical properties, surface topographic features, electrostatic charge, and biochemical mechanisms. At the nanoscale level, the physical properties of the underlying substrate are of particular importance in cell adhesion. Conventionally, natural, pro-adhesive, and often thrombogenic, protein biomaterials are frequently utilized to facilitate adhesion. In the present study, nanofabrication techniques are utilized to enhance the biological functionality of …

Impact Of Measurement Scale On Infiltration And Phosphorus Leaching In Ozark Floodplains, Derek M. Heeren, Garey A. Fox, Daniel E. Storm, Brian E. Haggard, Chad J. Penn, Todd Halihan

Department of Agricultural and Biological Systems Engineering: Faculty 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. The significance of this problem has been highlighted by litigation, with one case even reaching the U.S. Supreme Court (Arkansas et al. v. Oklahoma et al., 503 U.S. 91) which required the upstream state to meet downstream water quality standards. The overarching objective of this line of research was to characterize phosphorus leaching to alluvial aquifers in the …

Finite Element Modeling Of Phosphorus Leaching Through Floodplain Soils Dominated By Preferential Flow Pathways, Ryan P. Freiberger, Derek M. Heeren, Garey A. Fox

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Phosphorus is a critical nutrient in soils, providing both positive and negative effects to different systems. While optimum crop growth requires a range of P above 0.2 mg/L, preventing surface water enrichment generally requires P to be below 0.03 mg/L. Proper application and control of phosphorus is important to increase farming efficiency and to protect freshwater systems from toxic algal growth. While the movement of phosphorus through many soil types has been well-documented, the presence of highly conductive, gravel outcrops and macropores in soil can have a significant, poorly-documented effect on phosphorus movement. In the Ozark ecoregion, for example, the …

Application Of Isothermal Calorimetry To The Study Of Phosphorus Sorption Onto Soils In A Flow-Through System, Chad J. Penn, Derek M. Heeren, Garey A. Fox

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The degree, mechanisms, and kinetics of phosphorus (P) sorption onto soils can have a significant influence on leaching losses of P from soil. The objectives of this study were to measure the impact of retention time (RT) on P sorption in a flow-through system intended to simulate downward movement of a P solution through two different riparian soils, and determine if isothermal titration calorimetry (ITC) can provide useful information reflective of flow-through results. Topsoil from two riparian/alluvial soils was sampled and characterized for P concentrations and parameters related to P sorption. Flow-through P sorption experiments were conducted in order to …