Open Access. Powered by Scholars. Published by Universities.®

Bioresource and Agricultural Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

2012

Discipline
Institution
Keyword
Publication
Publication Type

Articles 61 - 90 of 121

Full-Text Articles in Bioresource and Agricultural Engineering

Complete Genome Sequence Of Thauera Aminoaromatica Strain Mz1t, Ke Jiang, John Sanseverino, Archana Chauhan, Susan Lucas, Alex Copeland, Alla Lapidus, Tijana Glavina Del Rio, Eileen Dalin, Hope Tice, David Bruce, Lynne Goodwin, Sam Pitluck, David Sims, Thomas Brettin, John C. Detter, Cliff Han, Y.J. Chang, Frank Larimer, Miriam Land, Loren Hauser, Nikos C. Kyrpides, Natalia Mikhailova, Scott Moser, Patricia Jegier, Dan Close, Jennifer M. Debruyn, Ying Wang, Alice C. Layton, Michael S. Allen, Gary S. Sayler Jan 2012

Complete Genome Sequence Of Thauera Aminoaromatica Strain Mz1t, Ke Jiang, John Sanseverino, Archana Chauhan, Susan Lucas, Alex Copeland, Alla Lapidus, Tijana Glavina Del Rio, Eileen Dalin, Hope Tice, David Bruce, Lynne Goodwin, Sam Pitluck, David Sims, Thomas Brettin, John C. Detter, Cliff Han, Y.J. Chang, Frank Larimer, Miriam Land, Loren Hauser, Nikos C. Kyrpides, Natalia Mikhailova, Scott Moser, Patricia Jegier, Dan Close, Jennifer M. Debruyn, Ying Wang, Alice C. Layton, Michael S. Allen, Gary S. Sayler

United States Department of Energy: Publications

Thauera aminoaromatica strain MZ1T, an isolate belonging to genus Thauera, of the family Rhodocyclaceae and the class the Betaproteobacteria, has been characterized for its ability to produce abundant exopolysaccharide and degrade various aromatic compounds with nitrate as an electron acceptor. These properties, if fully understood at the genome-sequence level, can aid in environmental processing of organic matter in anaerobic cycles by short-circuiting a central anaerobic metabolite, acetate, from microbiological conversion to methane, a critical greenhouse gas. Strain MZ1T is the first strain from the genus Thauera with a completely sequenced genome. The 4,496,212 bp chromosome and 78,374 bp plasmid …


The Crystal Structure Of The Extracellular 11-Heme Cytochromeundareveals A Conserved 10-Heme Motif And Defined Binding Site For Soluble Iron Chelates, Marcus J. Edwards, Andrea Hall, Liang Shi, James K. Fredrickson, John M. Zachara, Julea N. Butt, David J. Richardson, Thomas A. Clarke Jan 2012

The Crystal Structure Of The Extracellular 11-Heme Cytochromeundareveals A Conserved 10-Heme Motif And Defined Binding Site For Soluble Iron Chelates, Marcus J. Edwards, Andrea Hall, Liang Shi, James K. Fredrickson, John M. Zachara, Julea N. Butt, David J. Richardson, Thomas A. Clarke

United States Department of Energy: Publications

Members of the genus Shewanella translocate decaor undeca-heme cytochromes to the external cell surface thus enabling respiration using extracellular minerals and polynuclear Fe(III) chelates. The high resolution structure of the first undeca-heme outer membrane cytochrome, UndA, reveals a crossed heme chain with four potential electron ingress/ egress sites arranged within four domains. Sequence and structural alignment of UndA and the deca-heme MtrF reveals the extra heme of UndA is inserted between MtrF hemes 6 and 7. The remaining UndA hemes can be superposed over the heme chain of the decaheme MtrF, suggesting that a ten heme core is conserved between …


Three-Dimensional Bayesian Geostatistical Aquifer Characterization At The Hanford 300 Area Using Tracer Test Data, Xingyuan Chen, Haruko Murakami, Melanie S. Hahn, Glenn E. Hammond, Mark Rockhold, John M. Zachara, Yoram Rubin Jan 2012

Three-Dimensional Bayesian Geostatistical Aquifer Characterization At The Hanford 300 Area Using Tracer Test Data, Xingyuan Chen, Haruko Murakami, Melanie S. Hahn, Glenn E. Hammond, Mark Rockhold, John M. Zachara, Yoram Rubin

United States Department of Energy: Publications

Tracer tests performed under natural or forced gradient flow conditions can provide useful information for characterizing subsurface properties, through monitoring, modeling, and interpretation of the tracer plume migration in an aquifer. Nonreactive tracer experiments were conducted at the Hanford 300 Area, along with constant-rate injection tests and electromagnetic borehole flow meter tests. A Bayesian data assimilation technique, the method of anchored distributions (MAD) (Rubin et al., 2010), was applied to assimilate the experimental tracer test data with the other types of data and to infer the three-dimensional heterogeneous structure of the hydraulic conductivity in the saturated zone of the Hanford …


Analysis Of Phase Separation In High Performance Pbte–Pbs Thermoelectric Materials, Steven N. Girard, Klaus Schmidt-Rohr, Thomas C. Chasapis, Euripides Hatzikraniotis, B. Njegic, E. M. Levin, A. Rawal, Konstantinos M. Paraskevopoulos, Mercouri G. Kanatzidis Jan 2012

Analysis Of Phase Separation In High Performance Pbte–Pbs Thermoelectric Materials, Steven N. Girard, Klaus Schmidt-Rohr, Thomas C. Chasapis, Euripides Hatzikraniotis, B. Njegic, E. M. Levin, A. Rawal, Konstantinos M. Paraskevopoulos, Mercouri G. Kanatzidis

United States Department of Energy: Publications

Phase immiscibility in PbTe–based thermoelectric materials is an effective means of top-down synthesis of nanostructured composites exhibiting low lattice thermal conductivities. PbTe1− x Sx thermoelectric materials can be synthesized as metastable solid solution alloys through rapid quenching. Subsequent post-annealing induces phase separation at the nanometer scale, producing nanostructures that increase phonon scattering and reduce lattice thermal conductivity. However, there has yet to be any study investigating in detail the local chemical structure of both the solid solution and nanostructured variants of this material system. Herein, quenched and annealed (i.e., solid solution and phase-separated) samples of PbTe–PbS are analyzed …


Nanoscale Structure And Structural Relaxation In Zr50cu45al5 Bulk Metallic Glass, Jinwoo Hwang, Z. H. Melgarejo, Y. E. Kalay, I. Kalay, Matthew J. Kramer, D. S. Stone, P. M. Voyles Jan 2012

Nanoscale Structure And Structural Relaxation In Zr50cu45al5 Bulk Metallic Glass, Jinwoo Hwang, Z. H. Melgarejo, Y. E. Kalay, I. Kalay, Matthew J. Kramer, D. S. Stone, P. M. Voyles

United States Department of Energy: Publications

Hybrid reverse Monte Carlo simulations of the structure of Zr50Cu45Al5 bulk metallic glass incorporating medium-range structure from fluctuation electron microscopy data and short-range structure from an embedded atom potential produce structures with significant fractions of icosahedral- and crystal-like atomic clusters. Similar clusters group together into nanometer-scale regions, and relaxation transforms crystal-like clusters into icosahedral clusters. A model refined against only the potential does not agree with the fluctuation microscopy data and contains few crystal-like clusters.


Enhancement Of Thermopower Of Tags-85 High-Performance Thermoelectric Material By Doping With The Rare Earth Dy, E. M. Levin, S. L. Bud’Ko, K. Schmidt-Rohr Jan 2012

Enhancement Of Thermopower Of Tags-85 High-Performance Thermoelectric Material By Doping With The Rare Earth Dy, E. M. Levin, S. L. Bud’Ko, K. Schmidt-Rohr

United States Department of Energy: Publications

Enhancement of thermopower is achieved by doping the narrow-band semiconductor Ag6.52Sb6.52Ge36.96Te50 (acronym TAGS-85), one of the best p -type thermoelectric materials, with 1 or 2% of the rare earth dysprosium (Dy). Evidence for the incorporation of Dy into the lattice is provided by X-ray diffraction and increased orientation-dependent local fields detected by 125Te NMR spectroscopy. Since Dy has a stable electronic configuration, the enhancement cannot be attributed to 4f -electron states formed near the Fermi level. It is likely that the enhancement is due to a small reduction in the carrier …


Incorporating A Completely Renormalized Coupled Cluster Approach Into A Composite Method For Thermodynamic Properties And Reaction Paths, Sean A. Nedd, Nathan J. Deyonker, Angela K. Wilson, Mark S. Gordon, Piotr Piecuch Jan 2012

Incorporating A Completely Renormalized Coupled Cluster Approach Into A Composite Method For Thermodynamic Properties And Reaction Paths, Sean A. Nedd, Nathan J. Deyonker, Angela K. Wilson, Mark S. Gordon, Piotr Piecuch

United States Department of Energy: Publications

The correlation consistent composite approach (ccCA), using the S4 complete basis set two-point extrapolation scheme (ccCA-S4), has been modified to incorporate the left-eigenstate completely renormalized coupled cluster method, including singles, doubles, and non-iterative triples (CR-CC(2,3)) as the highest level component. The new ccCA-CC(2,3) method predicts thermodynamic properties with an accuracy that is similar to that of the original ccCA-S4 method. At the same time, the inclusion of the single-reference CR-CC(2,3) approach provides a ccCA scheme that can correctly treat reaction pathways that contain certain classes of multi-reference species such as diradicals, which would normally need to be treated by more …


Experimental And Theoretical Electronic Structure Of Eurh2as2, A. D. Palczewski, R. S. Dhaka, Y. Lee, Yogesh Singh, D. C. Johnston, B. N. Harmon, Adam Kaminski Jan 2012

Experimental And Theoretical Electronic Structure Of Eurh2as2, A. D. Palczewski, R. S. Dhaka, Y. Lee, Yogesh Singh, D. C. Johnston, B. N. Harmon, Adam Kaminski

United States Department of Energy: Publications

The Fermi surfaces (FS’s) and band dispersions of EuRh2As2 have been investigated using angle-resolved photoemission spectroscopy. The results in the high-temperature paramagnetic state are in good agreement with the full-potential linearized augmented-plane-wave calculations, especially in the context of the shape of the two-dimensional FS’s and band dispersion around the Γ (0,0) and X (π,π) points. Interesting changes in band folding are predicted by the theoretical calculations below the magnetic transition temperature TN ≈ 47 K. However, by comparing the FS’s measured at 60 and 40 K, we did not observe any signature of this transition at …


Magnetic And Structural Transitions In The Iron-Chalcogenide High-Tc Superconductor: K0.8fe1.76se2.00, W. N. Rowan-Weetaluktuk, D. H. Ryan, J. M. Cadogan, R. Hu, S. L. Bud’Ko, Paul C. Canfield Jan 2012

Magnetic And Structural Transitions In The Iron-Chalcogenide High-Tc Superconductor: K0.8fe1.76se2.00, W. N. Rowan-Weetaluktuk, D. H. Ryan, J. M. Cadogan, R. Hu, S. L. Bud’Ko, Paul C. Canfield

United States Department of Energy: Publications

57Fe Mössbauer spectroscopy was used to study single-crystals of K0.8Fe1.76Se2.00 from 6K to 673 K. At 6 K, the hyperfine field (Bhf) is canted away from the c-axis by 18±3°. The temperature dependence of Bhf follows a spin wave model with a spin excitation gap of 9±1 meV. A sudden increase in the line width and a corresponding drop in (1/2)eQVzz at TN = 532 K are indications of strong coupling between the magnetic and structural transitions.


Evaluation Of Niobium As Candidate Electrode Material For Dc High Voltage Photoelectron Guns, M. Bastaninejad, Md. Abdullah Mohamed, A. A. Elmustafa, P. Adderley, J. Clark, S. Covert, J. Hansknecht, C. Hernandez-Garcia, M. Poelker, R. Mammei, K. Surles-Law, P. Williams Jan 2012

Evaluation Of Niobium As Candidate Electrode Material For Dc High Voltage Photoelectron Guns, M. Bastaninejad, Md. Abdullah Mohamed, A. A. Elmustafa, P. Adderley, J. Clark, S. Covert, J. Hansknecht, C. Hernandez-Garcia, M. Poelker, R. Mammei, K. Surles-Law, P. Williams

United States Department of Energy: Publications

The field emission characteristics of niobium electrodes were compared to those of stainless steel electrodes using a DC high voltage field emission test apparatus. A total of eight electrodes were evaluated: two 304 stainless steel electrodes polished to mirror like finish with diamond grit and six niobium electrodes (two single-crystal, two large-grain, and two fine-grain) that were chemically polished using a buffered-chemical acid solution. Upon the first application of high voltage, the best large-grain and single-crystal niobium electrodes performed better than the best stainless steel electrodes, exhibiting less field emission at comparable voltage and field strength. In all cases, field …


Saturated–Unsaturated Flow In A Compressible Leaky-Unconfined Aquifer, Phoolendra Mishra, Velimir Vesselinov, Kristopher Kuhlman Jan 2012

Saturated–Unsaturated Flow In A Compressible Leaky-Unconfined Aquifer, Phoolendra Mishra, Velimir Vesselinov, Kristopher Kuhlman

United States Department of Energy: Publications

An analytical solution is developed for three-dimensional flow towards a partially penetrating largediameter well in an unconfined aquifer bounded below by a leaky aquitard of finite or semi-infinite extent. The analytical solution is derived using Laplace and Hankel transforms, then inverted numerically. Existing solutions for flow in leaky unconfined aquifers neglect the unsaturated zone following an assumption of instantaneous drainage due to Neuman. We extend the theory of leakage in unconfined aquifers by (1) including water flow and storage in the unsaturated zone above the water table, and (2) allowing the finite-diameter pumping well to partially penetrate the aquifer. The …


P96. Three-Dimensional Morphometry Of Human Cervical Endplates, Rebecca A. Wachs, Victoria M. Michna, Eric H. Ledet Jan 2012

P96. Three-Dimensional Morphometry Of Human Cervical Endplates, Rebecca A. Wachs, Victoria M. Michna, Eric H. Ledet

Department of Agricultural and Biological Systems Engineering: Faculty Publications

BACKGROUND CONTEXT: Degeneration of the cervical intervertebral disc is the underlying cause for many patients suffering from neck and upper extremity pain. Anterior cervical discectomy and fusion, and cervical disc replacements are common, but next generation implants and less invasive surgical techniques are predicated on a comprehensive characterization of cervical endplate morphology. To date, cervical endplate morphometry has not been described in detail, and age-related and gender- dependent differences have not been characterized.

PURPOSE: The purposes of this research were to measure cervical endplate morphometry in both men and women across three decades of life and characterize age, gender, and …


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 Jan 2012

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 Agricultural and Biological Systems Engineering: Faculty 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 …


Microstructural And Mineralogical Transformation Of Hydraulically Disposed Fly Ash—Implications To The Environment, Jabulani S. Mahlaba, Elsabe P. Kearsley, Richard A. Kruger Jan 2012

Microstructural And Mineralogical Transformation Of Hydraulically Disposed Fly Ash—Implications To The Environment, Jabulani S. Mahlaba, Elsabe P. Kearsley, Richard A. Kruger

Coal Combustion and Gasification Products Journal Archive

Increasing amounts of coal are combusted annually to meet the ever-increasing energy demands. The inevitable by-products include fly ash and saline effluents, which require acceptable disposal. The aim of this article is to compare the effect of hydraulic disposal with dry ash dumping. The results indicate that the former carries more environmental benefits based on the physical, chemical, and mineralogical aspects that were investigated.


Cordyline Fruticosa Growth And Soil Microbial Quality With Topical Application Of Coal Combustion By-Products Aggregates, Sangchul Hwang, Isomar Latorre, Eileen Irizarry Jan 2012

Cordyline Fruticosa Growth And Soil Microbial Quality With Topical Application Of Coal Combustion By-Products Aggregates, Sangchul Hwang, Isomar Latorre, Eileen Irizarry

Coal Combustion and Gasification Products Journal Archive

Coal combustion by-products aggregates (CCAs) are a solidified composite of fly and bottom ashes (2:1, by wt). Here, we assessed the feasibility of beneficial use of CCAs as a soil amendment or conditioner by conducting an outdoor experiment with Cordyline fruticosa (lucky plant) to determine its growth and soil microbial quality under the influence of topical CCA application (95 tons ha21). Enhanced growth of C. fruticosa with CCA application was noted, with respect to plant height, growth rate, leaf size, and leaf chlorophyll intensity. Soil dehydrogenase activity and total heterotrophic bacteria count were greater with topical CCA application, especially in …


Influence Of Activator Solution Formulation On Fresh And Hardened Properties Of Low-Calcium Fly Ash Geopolymer Concrete, Carlos Montes, Erez N. Allouche Jan 2012

Influence Of Activator Solution Formulation On Fresh And Hardened Properties Of Low-Calcium Fly Ash Geopolymer Concrete, Carlos Montes, Erez N. Allouche

Coal Combustion and Gasification Products Journal Archive

The effect of the composition of activator solutions on fresh and hardened properties of geopolymer concrete was investigated. Research variables included liquid sodium silicate product (DH, NH, and StarH), sodium hydroxide molar concentration (6, 10, and 14), and sodium silicate–to–sodium hydroxide ratio (1, 2, and 3). Response variables were compressive strength, corrosion resistance expressed as remaining compressive strength and mass loss, and flowability. Results were analyzed using Minitab statistical software. Findings suggest that activator solution formulation has a significant effect on the properties of the resulting geopolymer binder. The experimental design used was found effective in establishing the optimum activator …


Mineralogical Transformations In Coal Feedstocks During Carbon Conversion, Based On Packed-Bed Combustor Tests: Part 2. Behavior Of Individual Particles, Ratale H. Matjie, Colin R. Ward, Zhongsheng Li Jan 2012

Mineralogical Transformations In Coal Feedstocks During Carbon Conversion, Based On Packed-Bed Combustor Tests: Part 2. Behavior Of Individual Particles, Ratale H. Matjie, Colin R. Ward, Zhongsheng Li

Coal Combustion and Gasification Products Journal Archive

Handpicked carbon-rich particles (coal or char), mineral-rich particles (heated stones), and bonded stone aggregates (clinkers) from the upper and lower parts of a pilot-scale packed-bed combustor bed, designed to simulate conversion or combustion processes, were subjected to mineralogical and inorganic geochemical studies, in order to evaluate the reactions that may occur during carbon conversion at a particle-by-particle scale. The mineral matter of the carbon-rich particles was found to have higher proportions of carbonate minerals and kaolinite than the mineral-rich (stone) particles in the coal feedstocks used in the study, and to form phases such as anorthite, gehlenite, pyrrhotite, troilite, and …


Mineralogical Transformations In Coal Feedstocks During Carbon Conversion, Based On Packed-Bed Combustor Tests: Part 1. Bulk Coal And Ash Studies, Ratale H. Matjie, Colin R. Ward, Zhongsheng Li Jan 2012

Mineralogical Transformations In Coal Feedstocks During Carbon Conversion, Based On Packed-Bed Combustor Tests: Part 1. Bulk Coal And Ash Studies, Ratale H. Matjie, Colin R. Ward, Zhongsheng Li

Coal Combustion and Gasification Products Journal Archive

Mineralogical and inorganic geochemical studies have been carried out on composite samples of six different coarse-crushed (,120 mm) feed coals tested in a pilot-scale packed-bed combustor designed to simulate conversion and some fixed-bed combustion processes, and also on composite samples of the ashes produced. The mineral matter of the coals consisted mainly of quartz, kaolinite, and Ca-bearing carbonate minerals (calcite, dolomite, aragonite), with minor proportions of illite, pyrite, and several other phases, along with some Ca in an organically associated form. The base to acid ratio of the coal ashes ranged from 0.1 to 0.3, due mainly to variations in …


Potential Indoor Air Exposures And Health Risks From Mercury Off-Gassing Of Coal Combustion Products Used In Building Materials, Christopher M. Long, Sonja N. Sax, Ari S. Lewis Jan 2012

Potential Indoor Air Exposures And Health Risks From Mercury Off-Gassing Of Coal Combustion Products Used In Building Materials, Christopher M. Long, Sonja N. Sax, Ari S. Lewis

Coal Combustion and Gasification Products Journal Archive

Coal combustion products (CCPs), including coal fly ash (CFA) and flue gas desulfurization (FGD) gypsum, have gained accepted use as substitutes for traditional substances in building materials. Because of the presence of mercury (Hg) in CCP materials, some concerns have been raised regarding the potential for Hg to off-gas from building materials into indoor air. Risk assessment offers a well-accepted, objective framework in which to determine whether such off-gassing could result in humanexposures of health concern. We thus conducted a screening-level human health risk assessment to estimate worst-case inhalation risks from indoor air exposures to Hg for multiple CCP utilization …


Quantifying The Benefits Of Using Flue Gas Desulfurization Gypsum In Sustainable Wallboard Production, Jin Cheol Lee, Sabrina L. Bradshaw, Tuncer B. Edil, Craig H. Benson Jan 2012

Quantifying The Benefits Of Using Flue Gas Desulfurization Gypsum In Sustainable Wallboard Production, Jin Cheol Lee, Sabrina L. Bradshaw, Tuncer B. Edil, Craig H. Benson

Coal Combustion and Gasification Products Journal Archive

Electric utilities produce more than 11.2 Mt of flue gas desulfurization (FGD) gypsum annually. Approximately 7.5 Mt is used in wallboard production. This article examines the environmental and cost benefits associated with replacement of natural gypsum in wallboard with FGD gypsum. A life-cycle analysis program was used to quantify the benefits of using FGD gypsum from electric power production in wallboard construction. Comparisons were made between energy consumption, water use, and greenhouse gas (GHG) emissions associated with obtaining and processing virgin gypsum material and those with FGD gypsum. The added impact of disposing of the unused FGD gypsum in landfills …


Waste Classification Of Slag Generated In A Pilot-Scale Entrained-Flow Gasifier, Ashleigh Cousins, Robin W. Hughes, David J. Mccalden, Dennis Y. Lu, Edward J. Anthony Jan 2012

Waste Classification Of Slag Generated In A Pilot-Scale Entrained-Flow Gasifier, Ashleigh Cousins, Robin W. Hughes, David J. Mccalden, Dennis Y. Lu, Edward J. Anthony

Coal Combustion and Gasification Products Journal Archive

Series of gasification tests have been completed in the pilot-scale entrained-flow slagging gasifier at CanmetENERGY using Canadian coals, oil-sand coke, and blends of these fuels to determine if the produced slags are nonhazardous in nature. Solid wastes generated during these tests were analyzed for their trace metals, crystallinity, and toxic constituent leaching tendency in an attempt to provide more insight into the possibility of disposal or by-product use of gasifier-produced solid waste. The gasification tests were performed at conditions representative of commercial gasifiers using a dry-fuel-feed configuration. The lower-volatility elements were found to partition between the slag and process-water solids …


Trapping Phosphorus In Runoff With A Phosphorus Removal Structure, Chad J. Penn, Joshua M. Mcgrath, Elliott Rounds, Garey A. Fox, Derek M. Heeren Jan 2012

Trapping Phosphorus In Runoff With A Phosphorus Removal Structure, Chad J. Penn, Joshua M. Mcgrath, Elliott Rounds, Garey A. Fox, Derek M. Heeren

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Reduction of phosphorus (P) inputs to surface waters may decrease eutrophication. Some researchers have proposed fi ltering dissolved P in runoff with P-sorptive byproducts in structures placed in hydrologically active areas with high soil P concentrations. Th e objectives of this study were to construct and monitor a P removal structure in a suburban watershed and test the ability of empirically developed fl ow-through equations to predict structure performance. Steel slag was used as the P sorption material in the P removal structure. Water samples were collected before and after the structure using automatic samples and analyzed for total dissolved …


A Submersible Magnetic Stirrer For Use In Measuring Photosynthesis In A Biofloc Technology Production System, Bartholomew W. Green, E. Gregory O'Neal Jan 2012

A Submersible Magnetic Stirrer For Use In Measuring Photosynthesis In A Biofloc Technology Production System, Bartholomew W. Green, E. Gregory O'Neal

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Measuring photosynthesis or primary productivity in biofloc technology production systems is challenging because the biofloc must be maintained in suspension constantly. Photosynthesis can be measured in external incubators designed to keep the biofloc suspended in the biochemical oxygen demand (BOD) bottle, but primary productivity must be measured in the biofloc technology production system culture unit. Therefore, a submersible device is required to keep the biofloc suspended in the BOD bottle. This report details a submersible, air-powered magnetic stirrer that we designed, fabricated from off-the-shelf materials, and tested in biofloc technology production system tanks.


2012 Nebraska Water Monitoring Programs Report, Marty Link, Mike Archer Jan 2012

2012 Nebraska Water Monitoring Programs Report, Marty Link, Mike Archer

Nebraska Department of Environmental Quality: Reports

The following Nebraska Department of Environmental Quality staff have contributed to this report with their photos, maps, numbers, words, and editing. Their efforts are greatly appreciated and gratefully acknowledged here: Mike Archer, Ken Bazata, Dave Bubb, Ryan Chapman, Jason Garber, Patrick Hartman, Tom Heatherly, Dave Ihrie, Dan Inman, Greg Michl, Will Myers, Patrick O’Brien (NARD), Brad Routt, and Dave Schumacher.


Sparse Pseudospectral Approximation Method, Paul G. Constantine, Michael Eldred, Eric Phipps Jan 2012

Sparse Pseudospectral Approximation Method, Paul G. Constantine, Michael Eldred, Eric Phipps

United States Department of Energy: Publications

Multivariate global polynomial approximations – such as polynomial chaos or stochastic collocation methods – are now in widespread use for sensitivity analysis and uncertainty quantification. The pseudospectral variety of these methods uses a numerical integration rule to approximate the Fourier-type coefficients of a truncated expansion in orthogonal polynomials. For problems in more than two or three dimensions, a sparse grid numerical integration rule offers accuracy with a smaller node set compared to tensor product approximation. However, when using a sparse rule to approximately integrate these coefficients, one often finds unacceptable errors in the coefficients associated with higher degree polynomials.

By …


Raman/Rayleigh Scattering And Co-Lif Measurements In Laminar And Turbulent Jet Flames Of Dimethyl Ether, Frederik Fuest, Robert S. Barlow, Jyh-Yuan Chen, Andreas Dreizler Jan 2012

Raman/Rayleigh Scattering And Co-Lif Measurements In Laminar And Turbulent Jet Flames Of Dimethyl Ether, Frederik Fuest, Robert S. Barlow, Jyh-Yuan Chen, Andreas Dreizler

United States Department of Energy: Publications

To reduce the impact of combustion of fossil fuels on air quality and climate change, dimethyl ether (DME) is a promising alternative diesel fuel candidate. Technical combustion processes, including formation of pollutants, are influenced by turbulence–chemistry interaction. Therefore, accurate prediction by computational combustion models of combustion systems burning DME must account for multiple scalars and scalar gradients. The testing of such models requires detailed experiments. Here a study is presented on the feasibility of simultaneous species and temperature measurements in turbulent dimethyl ether flames, using line-imaged Raman/Rayleigh scattering of the major species H2, O2, N2 …


Application Of Pdf Mixing Models To Premixed Flames With Differential Diffusion, Edward Richardson, Jacqueline Chen Jan 2012

Application Of Pdf Mixing Models To Premixed Flames With Differential Diffusion, Edward Richardson, Jacqueline Chen

United States Department of Energy: Publications

Differential diffusion alters the balance of reaction and diffusion in turbulent premixed combustion, affecting the performance and emissions of combustion devices. Modelling combustion devices with Probability or Filtered Density Function (PDF or FDF) methods provides an exact treatment for the change in composition due to chemical reaction, while molecular mixing has to be modelled. Previous PDF molecular mixing models do not account for differential diffusion in a manner which satisfies realizability requirements. A new approach for treating differential diffusion, which ensures realizability, is proposed for pairwise-exchange mixing models in general, and applied in the Interaction by Exchange with the Mean …


Pore-Scale Characterization Of Biogeochemical Controls On Iron And Uranium Speciation Under Flow Conditions, Carolyn I. Pearce, Michael J. Wilkins, Changyong Zhang, Steve M. Heald, James K. Fredrickson, John M. Zachara Jan 2012

Pore-Scale Characterization Of Biogeochemical Controls On Iron And Uranium Speciation Under Flow Conditions, Carolyn I. Pearce, Michael J. Wilkins, Changyong Zhang, Steve M. Heald, James K. Fredrickson, John M. Zachara

United States Department of Energy: Publications

Etched silicon microfluidic pore network models (micromodels) with controlled chemical and redox gradients, mineralogy, and microbiology under continuous flow conditions are used for the incremental development of complex microenvironments that simulate subsurface conditions. We demonstrate the colonization of micromodel pore spaces by an anaerobic Fe(III)-reducing bacterial species (Geobacter sulfurreducens) and the enzymatic reduction of a bioavailable Fe(III) phase within this environment. Using both Xray microprobe and X-ray absorption spectroscopy, we investigate the combined effects of the precipitated Fe(III) phases and the microbial population on uranium biogeochemistry under flow conditions. Precipitated Fe(III) phases within the micromodel were most effectively …


Quantitative 3-D Elemental Mapping By La-Icp-Ms Of A Basaltic Clast From The Hanford 300 Area, Washington, Usa, Sheng Peng, Qinhong Hu, Robert Ewing, Chongxuan Liu, John M. Zachara Jan 2012

Quantitative 3-D Elemental Mapping By La-Icp-Ms Of A Basaltic Clast From The Hanford 300 Area, Washington, Usa, Sheng Peng, Qinhong Hu, Robert Ewing, Chongxuan Liu, John M. Zachara

United States Department of Energy: Publications

Laser ablation with inductively coupled plasma-mass spectrometry (LA-ICP-MS) was used to measure elemental concentrations at the 100-μm scale in a 3-dimensional manner within a basaltic clast sample collected from the Hanford 300 Area in south-central Washington State, United States. A calibration method was developed to quantify the LAICP- MS signal response using a constant-sum mass fraction of eight major elements; the method produced reasonable concentration measurements for both major and trace elements when compared to a standard basalt sample with known concentrations. 3-Dimensional maps (stacked 2-D contour layers, each representing 2100 μm × 2100 μm) show …


Molecular Underpinnings Of Fe(Iii) Oxide Reduction By Shewanella Oneidensis Mr-1, Liang Shi, Kevin Rosso, Tomas Clarke, David Richardson, John M. Zachara, James K. Fredrickson Jan 2012

Molecular Underpinnings Of Fe(Iii) Oxide Reduction By Shewanella Oneidensis Mr-1, Liang Shi, Kevin Rosso, Tomas Clarke, David Richardson, John M. Zachara, James K. Fredrickson

United States Department of Energy: Publications

In the absence of O2 and other electron acceptors, the Gram-negative bacterium Shewanella oneidensis MR-1 can use ferric [Fe(III)] (oxy) (hydr) oxideminerals as the terminal electron acceptors for an aerobic respiration. At circumneutral pH and in the absence of strong complexing ligands, Fe(III) oxides are relatively insoluble and thus are external to the bacterial cells. S. oneidensis MR-1 and related strains of metal-reducing Shewanella have evolved machinery (i.e.,metal-reducing or Mtr pathway) for transferring electrons from the inner-membrane, through the periplasmanda cross the outer-membrane to the surface of extracellular Fe(III) oxides. The protein components identified to date for the Mtr …