Bioresource and Agricultural Engineering Commons^™

Variable Frequency Drive (Vfd) Controlled Irrigation Pumps – Analysis Of Potential Rebate, Charles M. Burt

BioResource and Agricultural Engineering

Well pumps, booster pumps, and a combination of the two are used throughout the agricultural sector to provide water for on-farm irrigation. However, the pump discharge pressures for the majority of irrigation systems are excessive, waiving considerable monetary and power consumption savings. This report analyzes the numerous potential benefits of integrating a variable frequency drive (VFD) to irrigation supply systems and modifying system design philosophies.

Irrigation District Flow Metering, Charles M. Burt

BioResource and Agricultural Engineering

Most readers of this publication are probably somewhat familiar with USBR Reclamation Reform Act requirements for measurement of water deliveries to farm turnouts, in cases where the water is supplied by Reclamation facilities. Basically, volumes within the Mid-Pacific Region are supposed to be measured within ±6%. This sounds like a fairly straightforward requirement, but the reality is anything but simple.

The Irrigation Sector Shift From Construction To Modernization: What Is Required For Success?, Charles M. Burt

BioResource and Agricultural Engineering

External pressures related to environmental protection, commodity prices, energy availability, larger populations, and climate change have combined to require an immediate and substantial improvement in agricultural irrigation performance. Worldwide progression towards modernized irrigation projects has been uneven and slower than desired, but decades of irrigation modernization development have clarified certain requirements for success, as well as illuminated indicators of project failure. Of particular importance are required shifts within the state and national irrigation bureaucracies, as well as universities.

Motor Reference, Mohamed Grissa

BioResource and Agricultural Engineering

This document contains summary information about the following motor topics:

• Motor selection information
• AC induction motors
• Inverter duty motors
• Variable frequency drives
• Motor losses
• Troubleshooting

The information contained in this document was gathered from a variety of online, interview, and print sources, including NEMA specifications, with support from the California Energy Commission (CEC) PIER Program.

Effects Of Damköhler Number On Flame Extinction And Reignition In Turbulent Non-Premixed Flames Using Dns, David Lignell, Jacqueline Chen, Hans Schmutz

United States Department of Energy: Publications

Results from a parametric study of flame extinction and reignition with varying Damköhler number using direct numerical simulation are presented. Three planar, non-premixed ethylene jet flames were simulated at a constant Reynolds number of 5120. The fuel and oxidizer stream compositions were varied to adjust the steady laminar extinction scalar dissipation rate, while maintaining constant flow and geometric conditions. Peak flame extinction varies from approximately 40% to nearly global blowout as the Damköhler number decreases. The degree of extinction significantly affects the development of the jets and the degree of mixing of fuel, oxidizer, and combustion products prior to reignition. …

Variational Theory And Domain Decomposition For Nonlocal Problems, Burak Aksoylu, Michael L. Parks

United States Department of Energy: Publications

In this article we present the first results on domain decomposition methods for nonlocal operators. We present a nonlocal variational formulation for these operators and establish the well-posedness of associated boundary value problems, proving a nonlocal Poincaré inequality. To determine the conditioning of the discretized operator, we prove a spectral equivalence which leads to a mesh size independent upper bound for the condition number of the stiffness matrix. We then introduce a nonlocal two-domain variational formulation utilizing nonlocal transmission conditions, and prove equivalence with the single-domain formulation. A nonlocal Schur complement is introduced. We establish condition number bounds for the …

Automated Analysis Of Mouse Serum Peptidome Using Restricted Access Media And Nanoliquid Chromatography–Tandem Mass Spectrometry, Geun-Cheol Gil, Jim Brennan, Dan Throckmorton, Steven Branda, Gabriela Chirica

United States Department of Energy: Publications

We demonstrate use of restricted access media with reversed phase functionality (RAM-RP) for analysis of low molecular weight proteins and peptides in mouse serum (75ml) using a custom designed modular automated processing system (MAPS). RAM-RP fractionation with simultaneous removal of high molecular weight and high abundance proteins is integrated with a follow-on buffer exchange module (BE) to ensure compatibility with subsequent processing steps (trypsin digestion and intact peptide separation prior to mass spectrometric analysis). The high sample capacity afforded by chromatographic methods generates enough sample to achieve comprehensive serum peptidome identification (357 proteins) through tandem mass spectrometric analysis of both …

An Experimental And Kinetic Modeling Study Of Methyl Formate Low-Pressure Flames, S. Dooley, F. L. Dryer, B. Yang, J. Wang, T. A. Cool, T. Kasper, N. Hansen

United States Department of Energy: Publications

The oxidation of methyl formate (CH₃OCHO), the simplest methyl ester, is studied in a series of burnerstabilized laminar flames at pressures of 22–30 Torr and equivalence ratios (Φ) from 1.0 to 1.8 for flame conditions of 25–35% fuel. Flame structures are determined by quantitative measurements of species mole fractions with flame-sampling molecular-beam synchrotron photoionization mass spectrometry (PIMS). Methyl formate is observed to be converted to methanol, formaldehyde and methane as major intermediate species of mechanistic relevance. Smaller amounts of ethylene and acetylene are also formed from methyl formate oxidation. Reactant, product and major intermediate species profiles …

Reducing Error And Measurement Time In Impedance Spectroscopy Using Model Based Optimal Experimental Design, Francesco Ciucci, Thomas Carraro, William Chueh, Wei Lai

United States Department of Energy: Publications

In this work we introduce several novel tools for the reduction of errors in parameters estimated with electrochemical impedance spectroscopy experiments. An optimization strategy is developed that minimizes an estimate of the errors on the parameters while bounding the experimental time. The approach is also used to reduce experimental time while keeping a bound on the parameter errors. This feature is particularly critical in systems changing significantly within the experimental time. The paper uses a fuel cell electrode model to test this methodology and presents a real time algorithm for coupling experiment with the parameter estimation and experimental optimization.

Real-Space Study Of The Growth Of Magnesium On Ruthenium, T. Herranz, B. Santos, K.F. Mccarty, J. De La Figuera

United States Department of Energy: Publications

The growth of magnesium on ruthenium has been studied by low-energy electron microscopy (LEEM) and scanning tunneling microscopy (STM). In LEEM, a layer-by-layer growth is observed except in the first monolayer, where the completion of the first layer in inferred by a clear peak in electron reflectivity. Desorption from the films is readily observable at 400 K. Real-space STM and low-energy electron diffraction confirm that sub-monolayer coverage presents a moiré pattern with a 12 Å periodicity, which evolves with further Mg deposition by compressing the Mg layer to a 22 Å periodicity. Layer-by-layer growth is followed in LEEM up to …

Methods For Probabilistic Modeling Of Concentrating Solar Power Plants, Clifford Ho, Siri S. Khalsa, Gregory J. Kolb

United States Department of Energy: Publications

Probabilistic modeling of concentrating solar power technologies provides important information regarding uncertainties and sensitivities not available from deterministic models. Benefits of using probabilistic models include quantification of uncertainties inherent in the system and characterization of their impact on system performance and economics. This paper presents the tools necessary to conduct probabilistic modeling of concentrating solar technologies. The probabilistic method begins with the identification of uncertain variables and the assignment of appropriate distributions for those variables. Those parameters are then sampled using a stratified method (Latin Hypercube Sampling) to ensure complete and representative sampling from each distribution. Models of performance, reliability, …

Magnetically Driven Hyper-Velocity Launch Capability At The Sandia Z Accelerator, R. W. Lemke, M. D. Knudson,, J. P. Davis

United States Department of Energy: Publications

The intense magnetic field generated by the Z accelerator at Sandia National Laboratories is used as a pressure source for material science studies. A current of ∼20 MA can be delivered to the loads used in experiments on a time scale of ∼100-600 ns. Magnetic fields (pressures) exceeding 1200 T (600 GPa) have been produced in planar configurations. In one application we have developed, the magnetic pressure launches a flyer plate to ultra-high velocity in a plate impact experiment; equation of state data is obtained on the Hugoniot of a material that is shock compressed to multi-megabar pressure. This capability …

Multiple Benzene-Formation Paths In A Fuel-Rich Cyclohexane Flame, Wenjun Li, Matthew Law, Phillip Westmoreland, Tina Kasper, Nils Hansen, Katharina Kohse-Höinghaus

United States Department of Energy: Publications

Detailed data and modeling of cyclohexane flames establish that a mixture of pathways contributes to benzene formation and that this mixture changes with stoichiometry. Mole-fraction profiles are mapped for more than 40 species in a fuel-rich, premixed flat flame (Φ = 2.0, cyclohexane/O₂/30% Ar, 30 Torr, 50.0 cm/s) using molecular-beam mass spectrometry with VUV-photoionization at the Advanced Light Source of the Lawrence Berkeley National Laboratory. The use of a newly constructed set of reactions leads to an excellent simulation of this flame and an earlier stoichiometric flame (M.E. Law et al., Proc. Combust. Inst. 31 (2007) 565–573), …

Structure Of N-Heptane/Air Triple Flames In Partially-Premixed Mixing Layers, J. Prager, H. N. Najm, M. Valorani, D.A. Goussis

United States Department of Energy: Publications

Results of a detailed numerical analysis of an n-heptane/air edge flame are presented. The equations of a low-Mach number reacting flow are solved in a two-dimensional domain using detailed models for species transport and chemical reactions. The reaction mechanism involves 560 species and 2538 reversible reactions. We consider an edge flame that is established in a mixing layer with a uniform velocity field. The mixing layer spans the equivalence ratios between pure air and 3.5. The detailed model enables us to analyze the chemical structure of the n-heptane edge flame. We identify major species profiles, discuss reactions causing the heat-release, …

Roaming Radicals In The Thermal Decomposition Of Dimethyl Ether: Experiment And Theory, R. Sivaramakrishnan, J. Michael, A. Wagner, R. Dawes, A. Jasper, L. Harding, Y. Georgievskii, S. Klippenstein

United States Department of Energy: Publications

The thermal dissociation of dimethyl ether has been studied with a combination of reflected shock tube experiments and ab initio dynamics simulations coupled with transition state theory based master equation calculations. The experiments use the extraordinary sensitivity provided by H-atom ARAS detection with an unreversed light source to measure both the total decomposition rate and the branching to radical products versus molecular products, with the molecular products arising predominantly through roaming according to the theoretical analysis. The experimental observations also provide a measure of the rate coefficient for H + CH3OCH3. An evaluation of the available experimental results for H …

A Review Of Polymer Electrolyte Membrane Fuel Cells: Technology, Applications, And Needs On Fundamental Research, Yun Wang, Ken Chen, Jeffrey Mishler, Sung Chan Cho, Xavier Cordobes Adroher

United States Department of Energy: Publications

Polymer electrolyte membrane (PEM) fuel cells, which convert the chemical energy stored in hydrogen fuel directly and efficiently to electrical energy with water as the only byproduct, have the potential to reduce our energy use, pollutant emissions, and dependence on fossil fuels. Great deal of efforts has been made in the past, particularly during the last couple of decades or so, to advance the PEM fuel cell technology and fundamental research. Factors such as durability and cost still remain as the major barriers to fuel cell commercialization. In the past two years, more than 35% cost reduction has been achieved …

Direct Numerical Simulations Of Ignition Of A Lean N-Heptane/Air Mixture With Temperature Inhomogeneities At Constant Volume: Parametric Study, Chun Sang Yoo, Tianfeng Lu, Jacqueline Chen, Chung K. Law

United States Department of Energy: Publications

The effect of thermal stratification on the ignition of a lean homogeneous n-heptane/air mixture at constant volume and high pressure is investigated by direct numerical simulations (DNS) with a new 58- species reduced kinetic mechanism developed for very lean mixtures from the detailed LLNL mechanism (H.J. Curran et al., Combust. Flame 129 (2002) 253–280). Two-dimensional DNS are performed in a fixed volume with a two-dimensional isotropic velocity spectrum and temperature fluctuations superimposed on the initial scalar fields. The influence of variations in the initial temperature field, imposed by changing the mean and variance of temperature, and the ratio of turbulence …

Solution And Microbial Controls On The Formation Of Reduced U(Iv) Species, Maxim I. Boyanov, Kelly E. Fletcher, Man Jae Kwon, Xue Rui, Edward J. O’Loughlin, Frank E. Löffler, Kenneth M. Kemner

United States Department of Energy: Publications

Reduction of U^VI to U^IV as the result of direct or indirect microbial activity is currently being explored for in situ remediation of subsurface U plumes, under the assumption that UIV solubility is controlled by the low solubility mineral uraninite (U^IV-dioxide). However, recent characterizations of U in sediments from biostimulated field sites, as well as laboratory U^VI bioreduction studies, report on the formation of U^IV species that lack the U=O₂=U coordination of uraninite, suggesting that phases other than uraninite may be controlling U^IV solubility in environments with complexing surfaces and ligands. …

Identification And Characterization Of Undahrcr-6, An Outer Membrane Endecaheme C-Type Cytochrome Of Shewanella Sp. Strain Hrcr-6, Liang Shi, Sara M. Belchik, Zheming Wang, David W. Kennedy, Alice C. Dohnalkova, Matthew J. Marshall, John M. Zachara, James K. Fredrickson

United States Department of Energy: Publications

UndA_HRCR-6 was identified from the metal-reducing bacterium Shewanella sp. strain HRCR-6. Both in vivo and in vitro characterization results indicate that UndA_HRCR-6 is an outer membrane endecaheme c-type cytochrome and probably has a key functional role in the extracellular reduction of iron [Fe(III)] oxides and uranium [U(VI)] by Shewanella sp. HRCR-6.

Purification And Characterization Of The [Nife]-Hydrogenase Of Shewanella Oneidensis Mr-1, Liang Shi, Sara M. Belchik, Andrew E. Plymale, Steve Heald, Alice C. Dohnalkova, Kateryna Sybirna, Herve Bottin, Thomas C. Squier, John M. Zachara, James K. Fredrickson

United States Department of Energy: Publications

Shewanella oneidensis MR-1 possesses a periplasmic [NiFe]-hydrogenase (MR-1 [NiFe]-H₂ase) that has been implicated in H₂ production and oxidation as well as technetium [Tc(VII)] reduction. To characterize the roles of MR-1 [NiFe]-H₂ase in these proposed reactions, the genes encoding both subunits of MR-1 [NiFe]-H₂ase were cloned and then expressed in an MR-1 mutant without hyaB and hydA genes. Expression of recombinant MR-1 [NiFe]-H₂ase in trans restored the mutant’s ability to produce H₂ at 37% of that for the wild type. Following purification, MR-1 [NiFe]-H2ase coupled H₂ oxidation to …