Bioresource and Agricultural Engineering Commons^™

Expansion Of A Dust Removal System For The Brae Department Plasma Table, Derek Hansen

BioResource and Agricultural Engineering

This senior project discusses the expansion of a dust removal system for welding and cutting fumes. A Donaldson Torit Powercore TG8 dust collector is used to collect and process the fumes created during welding and cutting operations that take place in the BioResource and Agricultural Engineering department at Cal Poly San Luis Obispo. Expansion of the system allows for greatly increased utilization of the TG8 and a cleaner working environment in Lab #6. Testing shows that the system fluently changes between the plasma table and the three hoods in the shop. Each hood is only capable of collecting a smoke …

Wheat Strip Effects On Nutrient Loads Following Variable Manure Applications, Chance Thayer, John E. Gilley, Lisa M. Durso, David B. Marx

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Vegetative filters have been found to significantly reduce nutrient loads in runoff. This study was conducted to: (1) evaluate the effects of a narrow wheat strip, varying manure application rates, and different overland flow rates on runoff nutrient loads following application of beef cattle manure; (2) determine the upper capacity of a narrow wheat strip to reduce nutrient loads by applying excessive amounts of manure; and (3) compare the effectiveness of narrow wheat strips and grass hedges in reducing runoff nutrient loads. A 1.4 m wide strip of actively growing winter wheat was located at the bottom of selected 0.75 …

Identification And Characterization Of Mtoa: A Decaheme C-Type Cytochrome Of The Neutrophilic Fe(Ii)-Oxidizing Bacterium Sideroxydans Lithotrophicus Es-1, Juan Liu, Zheming Wang, Sara M. Belchik, Marcus J. Edwards, Chongxuan Liu, David W. Kennedy, Eric D. Merkley, Mary S. Lipton, Julea N. Butt, David J. Richardson, John M. Zachara, James K. Fredrickson, Kevin M. Rosso, Liang Shi

United States Department of Energy: Publications

The Gram-negative bacterium Sideroxydans lithotrophicus ES-1(ES-1) grows on FeCO₃ or FeS at oxic–anoxic interfaces at circumneutral pH, and the ES-1-mediated Fe(II) oxidation occurs extracellularly. However, the molecular mechanisms underlying ES-1’s ability to oxidize Fe(II) remain unknown. Survey of the ES-1 genome for candidate genes formicrobial extracellular Fe(II) oxidation revealed that it contained a three-genecluster encoding homologs of Shewanella oneidensis MR-1(MR-1) MtrA, MtrB, and CymA that are involved in extracellular Fe(III) reduction. Homologs of MtrA and MtrB were also previously shown to be involved in extracellular Fe(II) oxidation by Rhodopseudomonas palustris TIE-1. To distinguish them from those found in MR-1, …

2012 Nebraska Groundwater Quality Monitoring Report

Nebraska Department of Environmental Quality: Reports

The 2001 Nebraska Legislature passed LB329 (Neb. Rev. Stat. §46-1304) which, in part, directed the Nebraska Department of Environmental Quality (NDEQ) to report on groundwater quality monitoring in Nebraska. Reports have been issued annually since December 2001. The text of the statute applicable to this report follows: “The Department of Environmental Quality shall prepare a report outlining the extent of ground water quality monitoring conducted by natural resources districts during the preceding calendar year. The department shall analyze the data collected for the purpose of determining whether or not ground water quality is degrading or improving and shall present the …

Antiferromagnetic Order In The Quasicrystal Approximant Cd6tb Studied By X-Ray Resonant Magnetic Scattering, M. G. Kim, G. Beutier, A. Kreyssig, T. Hiroto, T. Yamada, J. W. Kim, M. De Boissieu, R. Tamura, A. I. Goldman

United States Department of Energy: Publications

We have used x-ray resonant magnetic scattering at the Tb L₂ edge to elucidate the nature of magnetic ordering in Cd₆Tb, a 1/1 approximant closely related to the Cd-Mg-R (R = rare earth) icosahedral alloys. Below T_N ≈ 24 K, the ordered moments associated with the icosahedral clusters at the corners and body center of the pseudocubic unit cell are antiferromagnetically correlated, and long-range magnetic order is realized.

Pump Performance With Sand Wear, Charles M. Burt, Kyle Fesit

BioResource and Agricultural Engineering

In many installations, pump performance declines over time due to sand wear. In order to pinpoint the type and rate of wear caused by pumping water with higher-than-average sand concentrations and its direct effect on various pump impeller materials, vertical pump impeller/bowl assemblies of approximately 900 GPM were each pumped for up to 2500 hours with high concentrations of sand in the water. Two different impeller materials were used for a total of five configurations. Well pump operation was simulated by maintaining a constant discharge pressure. The degrading performance, in terms of changing flow rate and kilowatt load, was recorded …

Spatial Variability In Evapotranspiration Related To Irrigation System Distribution Uniformity, Daniel J. Howes, Lucas Hoffmann, Franklin Gaudi

BioResource and Agricultural Engineering

Understanding the causes of variable ET in a field is critical for maximizing yield on a per-acre basis as well as for proper irrigation scheduling and regional water management. Since 2004, the ITRC has provided technical irrigation support and management for over 2,000 acres of center pivot irrigated forage crops being supplied by reclaimed water near Palmdale, California. Irrigation scheduling is conducted using a daily soil water balance dual crop coefficient approach. Detailed records on planting and harvest dates, daily water applications, pivot run speeds, and annual distribution uniformity evaluations are maintained along with daily reference evapotranspiration data from a …

Dielectric Function Spectra And Critical-Point Energies Of Cu2znsnse4 From 0.5 To 9.0 Ev, S. . G. Choi, H. . Y. Zhao, C. Persson, C. L. Perkins, A Donohue, B To, A. G. Norman, J Li, I. L. Repins

United States Department of Energy: Publications

We present dielectric function e=e₁+ie₂spectra and critical-point energies of Cu₂ZnSnSe₄ determined by spectroscopic ellipsometry from 0.5 to 9.0 eV. We reduce artifacts from surface overlayers to the maximum extent possible by performing chemical-mechanical polishing and wet-chemical etching of the surface of a Cu₂ZnSnSe₄ thin film. Ellipsometric data are analyzed by the multilayer model and the e spectra are extracted. The data exhibit numerous spectral features associated with critical points, whose energies are obtained by fitting standard lineshapes to second energy derivatives of the data. The experimental results are in good …

The Sintering Behavior Of Close-Packed Spheres, R. Bjørk, V. Tikare, H. L. Frandsen, N. Pryds

United States Department of Energy: Publications

The sintering behavior and microstructural evolution of a powder compact is influenced strongly by initial properties, such as the relative density, the particle and pore size distribution, and the powder packing. While the influence of the former parameters on the microstructural evolution has been investigated in some detail, the impact of the initial packing of the powder has been mostly overlooked. However, research has shown that the sintering behavior of a powder can be significantly improved if the powder is regularly packed.

This has been shown for monodisperse spherical TiO2 particles [1], which sintered 10 times faster and exhibited almost …

The Hardness And Strength Of Metal Tribofilms: An Apparent Contradiction Between Nanoindentation And Pillar Compression, Corbett C. Battaile, Brad L. Boyce, Christopher Weinberger, Somuri Prasad, Joseph R. Michael, Blythe G. Clark

United States Department of Energy: Publications

After sliding contact of a hard spherical counterface on a metal surface, the resulting wear scar possesses a complex microstructure consisting of dislocations, dislocation cells, ultrafine or nanocrystalline grains, and material that has undergone dynamic recovery. There remains a controversy as to the mechanical properties of the tribolayer formed in this wear scar. To investigate the properties of this thin layer of damaged material in single crystal nickel, we employed two complementary techniques: pillar compression and nanoindentation. In both techniques, the tests were tailored to characterize the near surface properties associated with the top 500 nm of material, where the …

Pore Scale Analysis Of The Impact Of Mixing-Induced Reaction Dependent Viscosity Variations, S.M. Davison, H. Yoon, M. J. Martinez

United States Department of Energy: Publications

Expanding interest in enhanced subsurface natural resource recovery and carbon sequestration motivates study of reacting flows in porous media. In this work, we examine the case of reaction products that increase or decrease the viscosity of the fluid. Parallel reactant streams flow through porous media and react transversely along the centerline. We utilize a pore scale, finite element numerical method that couples the reaction with fluid flow through two arrangements of porous media at three Damkohler (Da) numbers and two viscosity conditions. When the product increases the fluid viscosity, the flow velocity is reduced and higher amounts of …

The Fundamental Equation Of Eddy Covariance And Its Application In Flux Measurements, Lianhong Gu, William J. Massman, Ray Leuning, Stephen Pallardy, Tilden Meyers, Paul Hanson, Jeffery Riggs, Kevin Hosman, Bai Yang

United States Department of Energy: Publications

A fundamental equation of eddy covariance (FQEC) is derived that allows the net ecosystem exchange (NEE) N̅s of a specified atmospheric constituent s to be measured with the constraint of conservation of any other atmospheric constituent (e.g. N2, argon, or dry air). It is shown that if the condition │N̅s│ ˃˃ │X̅s│ │N̅co2│is true, the conservation of mass can be applied with the assumption of no net ecosystem source or sink of dry air and the FQEC is reduced to the following equation and its approximation for horizontally homogeneous mass fluxes:

N̅_s = c̅_dw’X’_{s …}

A Non-Premixed Combustion Model Based On Flame Structure Analysis At Supercritical Pressures, Guilhem Lacaze, Joseph Oefelein

United States Department of Energy: Publications

This work presents a study of non-premixed flames at supercritical-pressure conditions. Emphasis is placed on flame stability in liquid rocket engines fueled with liquid oxygen and gaseous hydrogen. The flame structure sensitivity to strain, pressure, temperature and real-fluid effects was investigated in detailed opposed-jet flames calculations. It is shown that the flame is very robust to strain, that the flamelet assumption is valid for the conditions of interest, and that real-fluid phenomena can have a significant impact on flame topology. At high-pressure supercritical conditions, small pressure or temperature variations can induce strong changes of thermodynamic properties across the flame. A …

Field Ion Source Development For Neutron Generators, B. Bargsten Johnson, P. R. Schwoebel, C. E. Holland, P. J. Resnick, K L. Hertz, D L. Chichester

United States Department of Energy: Publications

An ion source based on the principles of electrostatic field desorption is being developed to improve the performance of existing compact neutron generators. The ion source is an array of gated metal tips derived from field electron emitter array micro fabrication technology. A comprehensive summary of development and experimental activities is presented. Many structural modifications to the arrays have been incorporated to achieve higher tip operating fields, while lowering fields at the gate electrode to prevent gate field electron emission which initiates electrical breakdown in the array. The latest focus of fabrication activities has been on rounding the gate electrode …

Numerical Simulation Of Expansion And Charring Of Carbon-Epoxy Laminates In Fire Environments, Matthew Mcgurn, Paul Desjardin, Amanda Dodd

United States Department of Energy: Publications

A thermal model is developed for the response of carbon-epoxy composite laminates in fire environments. The model is based on a porous media description that includes the effects of gas transport within the laminate along with swelling. Model comparisons are conducted against the data from Quintiere et al. [34]. Verifications are conducted for both coupon level and intermediate scale one-sided heating tests. Comparisons of the heat release rate (HRR) and time-to-ignition as well as the final products (mass fractions, volume percentages, porosity, etc.) are conducted. Overall, the agreement between available the data and model is good considering the simplified approximations …

Combined Finite Element And Peridynamic Analyses For Predicting Failure In A Stiffened Composite Curved Panel With A Central Slot, Erkan Oterkus, Erdogan Madenci, Olaf Weckner, Stewart Silling, Philip Bogert, Alexander Tessler

United States Department of Energy: Publications

This study presents an analysis approach based on a merger of the finite element method and the peridynamic theory. Its validity is established through qualitative and quantitative comparisons against the test results for a stiffened composite curved panel with a central slot under combined internal pressure and axial tension. The predicted initial and final failure loads, as well as the final failure modes, are in close agreement with the experimental observations. This approach demonstrates the capability of the PD approach to assess the durability of complex composite structures.

A Reaction Progress Variable Modeling Approach For Non-Ideal Multiphase Explosives, K. P. Ruggirello, P. E. Desjardin, M. R. Baer, M. J. Kaneshige, E. S. Hertel

United States Department of Energy: Publications

This study concerns the development of a mixture fraction based reaction progress variable formulation for aluminized explosives. Highlights of the formulation include a fully compressible treatment of both the gas and solid phases (both aluminum and alumina), heterogenous and homogenous reactions, and effects of group combustion. Isolated particle simulations are validated against experimental data and DNS and show good agreement of burn times over a range of pressure and oxygen environments. The new models are implemented in the CTH shock physics code using a fractional step approach to allow for efficient computation of particle dynamics. Comparisons are made to experimental …

An Experimental And Theoretical Study Of Heat And Mass Transfer During The Venting Of Gas From Pressure Vessels, W. S. Winters, G. H. Evans, S. F. Rice, R. Greif

United States Department of Energy: Publications

Non condensing gas flow and heat transfer during venting of vessels are studied using experiments and analysis. A high pressure helium supply vessel is connected to a low pressure receiver via orifice and tubing. A single control volume analysis and a multi-dimensional analysis are used to predict pressure and mass-averaged temperature in the supply. Experiments utilizing transient PVT methods are conducted to obtain transient pressure and mass-averaged temperature data for validating the analysis. Measured transient pressures and mass-averaged temperatures in the supply are reproduced by analysis. Heat transfer is due to natural convection except for the early part of transfer.

A Functional Description Of Cyma, An Electron-Transfer Hub Supporting Anaerobic Respiratory Flexibility In Shewanella, Sophie J. Marritt, Thomas G. Lowe, Jordan Bye, Duncan G. G. Mcmillan, Liang Shi, James K. Fredrickson, John M. Zachara, David J. Richardson, Myles R. Cheesman, Lars J. C. Jeuken, Julea N. Butt

United States Department of Energy: Publications

CymA (tetrahaem cytochrome c) is a member of the NapC/NirT family of quinol dehydrogenases. Essential for the anaerobic respiratory flexibility of shewanellae, CymA transfers electrons from menaquinol to various dedicated systems for the reduction of terminal electron acceptors including fumarate and insoluble minerals of Fe(III). Spectroscopic characterization of CymA from Shewanella oneidensis strain MR-1 identifies three lowspin His/His co-ordinated c-haems and a single high-spin chaem with His/H₂O co-ordination lying adjacent to the quinolbinding site. At pH 7, binding of the menaquinol analogue, 2-heptyl-4-hydroxyquinoline-N-oxide, does not alter the midpoint potentials of the high-spin (approximately −240 mV) …

Exploring The Biochemistry At The Extracellular Redox Frontier Of Bacterial Mineral Fe(Iii) Respiration, David J. Richardson, Marcus J. Edwards, Gaye F. White, Nanakow Baiden, Robert S. Hartshorne, James K. Fredrickson, Liang Shi, John M. Zachara, Andrew J. Gates, University Of East Anglia, Thomas Clarke

United States Department of Energy: Publications

Many species of the bacterial Shewanella genus are notable for their ability to respire in anoxic environments utilizing insoluble minerals of Fe(III) and Mn(IV) as extracellular electron acceptors. In Shewanella oneidensis, the process is dependent on the decahaem electron-transport proteins that lie at the extracellular face of the outer membrane where they can contact the insoluble mineral substrates. These extracellular proteins are charged with electrons provided by an inter-membrane electron-transfer pathway that links the extracellular face of the outer membrane with the inner cytoplasmic membrane and thereby intracellular electron sources. In the present paper, we consider the common structural …