Bioresource and Agricultural Engineering Commons^™

Electron Donor-Dependent Radionuclide Reduction And Nanoparticle Formation By Anaeromyxobacter Dehalogenans Strain 2cp-C, Matthew J. Marshall, Alice C. Dohnalkova, David Kennedy, Andrew Plymale, Sara Thomas, Frank Löffler, Robert Sanford, John M. Zachara, James K. Fredrickson, Alexander Beliaev

United States Department of Energy: Publications

Anaeromyxobacter dehalogenans strain 2CP-C reduces U(VI) and Tc(VII) to U(IV)O_2(s) (uraninite) and Tc(IV)O2(S) respectively. Kinetic studies with resting cells revealed that U(VI) or Tc(VII) reduction rates using H₂ as electron donor exceeded those observed in acetate-amended incubations. The reduction of U(VI) by A. dehalogenans 2CP-C resulted in extracellular accumulation of ~5 nm uraninite nanoparticles in association with a lectin-binding extracellular polymeric substance (EPS). The electron donor did not affect UO_2(S) nanoparticle size or association with EPS, but the utilization of acetate as the source of reducing equivalents resulted in distinct UO_2(S) nanoparticle aggregates that were ~50 …

The Roles Of Outer Membrane Cytochromes Of Shewanella And Geobacter In Extracellular Electron Transfer, Liang Shi, David J. Richardson, Zheming Wang, Sebastien Kerisit, Kevin Rosso, John M. Zachara, James K. Fredrickson

United States Department of Energy: Publications

As key components of the electron transfer (ET) pathways used for dissimilatory reduction of solid iron [Fe(III)] (hydr)oxides, outer membrane multihaem c-type cytochromes MtrC and OmcA of Shewanella oneidensis MR-1 and OmcE and OmcS of Geobacter sulfurreducens mediate ET reactions extracellularly. Both MtrC and OmcA are at least partially exposed to the extracellular side of the outer membrane and their translocation across the outer membrane is mediated by bacterial type II secretion system. Purified MtrC and OmcA can bind Fe(III) oxides, such as haematite (α-Fe₂O₃), and directly transfer electrons to the haematite surface. Bindings of …

Kinetics Of Uranium(Vi) Desorption From Contaminated Sediments: Effect Of Geochemical Conditions And Model Evaluation, Chongxuan Liu, Zhenqing Shi, John M. Zachara

United States Department of Energy: Publications

Stirred-flow cell experiments were performed to investigate the kinetics of uranyl [U(VI)] desorption from a contaminated sediment collected from the Hanford 300 Area at the U.S. Department of Energy Hanford Site, Washington. Three influent solutions of variable pH, Ca and carbonate concentrations that affected U(VI) aqueous and surface speciation were used under dynamic flow conditions to evaluate the effect of geochemical conditions on the rate of U(VI) desorption. The measured rate of U(VI) desorption varied with solution chemical composition that evolved as a result of thermodynamic and kinetic interactions between the solutions and sediment. The solution chemical composition that led …

Uranium Speciation As A Function Of Depth In Contaminated Hanford Sediments - A Micro-Xrf, Micro-Xrd, And Micro- And Bulk-Xafs Study, David Singer, John M. Zachara, Gordon Brown

United States Department of Energy: Publications

The distribution and speciation of U and Cu in contaminated vadose zone and aquifer sediments from the U.S. DOE Hanford site (300 Area) were determined using a combination of synchrotron-based micro-X-ray fluorescence (μXRF) imaging, micro-X-ray absorption near edge structure (μXANES) spectroscopy, and micro-X-ray diffraction (μXRD) techniques combined with bulk U L_III-edge X-ray absorption fine structure (XAFS) spectroscopy. Samples were collected from within the inactive North Process Pond (NPP2) at 8 ft (2.4 m, NPP2-8) depth and 12 ft (3.7 m, NPP2-12) depth in the vadose zone, and fines were isolated from turbid groundwater just below the water Table …

Newly Recognized Hosts For Uranium In The Hanford Site Vadose Zone, Joanne E. Stubbs, Linda A. Veblen, David C. Elbert, John M. Zachara, James A. Davis, David R. Veblen

United States Department of Energy: Publications

Uranium contaminated sediments from the U.S. Department of Energy’s Hanford Site have been investigated using electron microscopy. Six classes of solid hosts for uranium were identified. Preliminary sediment characterization was carried out using optical petrography, and electron microprobe analysis (EMPA) was used to locate materials that host uranium. All of the hosts are fine-grained and intergrown with other materials at spatial scales smaller than the analytical volume of the electron microprobe. A focused ion beam (FIB) was used to prepare electron-transparent specimens of each host for the transmission electron microscope (TEM). The hosts were identified as: (1) metatorbernite [Cu(UO_{2 …}

Oxidative Dissolution Potential Of Biogenic And Abiogenic Tco2 In Subsurface Sediments, James K. Fredrickson, John M. Zachara, Andrew Plymale, Steve M. Heald, James Mckinley, David Kennedy, Chongxuan Liu, Ponnusamy Nachimuthu

United States Department of Energy: Publications

Technetium-99 (Tc) is an important fission product contaminant associated with sites of nuclear fuels reprocessing and geologic nuclear waste disposal. Tc is highly mobile in its most oxidized state [Tc(VII)O₄⁻] and less mobile in the reduced form [Tc(IV)O₂•nH₂O]. Here we investigate the potential for oxidation of Tc(IV) that was heterogeneously reduced by reaction with biogenic Fe(II) in two sediments differing in mineralogy and aggregation state; unconsolidated Pliocene-age fluvial sediment from the upper Ringold (RG) Formation at the Hanford Site and a clay-rich saprolite from the Field Research Center (FRC) background site …

Characterization Of An Electron Conduit Between Bacteria And The Extracellular Environment, Robert Hartshorne, Catherine Reardon, Daniel Ross, Jochen Nuester, Thomas Clarke, Andrew Gates, Paul Mills, James K. Fredrickson, John M. Zachara, Liang Shi, Alexander Beliaev, Matthew Marshall, Ming Tien, Susan Brantley, Julea N. Butt, David J. Richardson

United States Department of Energy: Publications

A number of species of Gram-negative bacteria can use insoluble minerals of Fe(III) and Mn(IV) as extracellular respiratory electron acceptors. In some species of Shewanella, deca-heme electron transfer proteins lie at the extracellular face of the outer membrane (OM), where they can interact with insoluble substrates. To reduce extracellular substrates, these redox proteins must be charged by the inner membrane/periplasmic electron transfer system. Here, we present a spectro-potentiometric characterization of a trans-OM icosa-heme complex, MtrCAB, and demonstrate its capacity to move electrons across a lipid bilayer after incorporation into proteoliposomes. We also show that a stable MtrAB …

Photoionization Cross Sections For Ions Of The Cerium Isonuclear Sequence, M. Habibi, D. A. Esteves, R. A. Phaneuf, A. L. D. Kilcoyne, A. Aguilar, C. Cisneros

United States Department of Energy: Publications

Photoionization cross sections for Ce^q+ (1 ≤ q ≤ 9) ions were measured in the 105–180 eV energy range of the 4d inner-shell giant resonance by merging a mass-to-charge-ratio-selected ion beam with a beam of monochromatized synchrotron radiation. The Cowan atomic structure code was used as an aid to interpret the experimental data. Four Rydberg series for 4d→nf (n ≥ 4) and 4d→np (n ≥ 6) autoionizing excitations were assigned using the quantum-defect theory in the Ce³⁺ photoionization cross section. The experimental data show the collapse of the nf wave functions (n ≥ 4) with …

Electronic Inhomogeneity And Ag:Sb Imbalance Of Ag1−Ypb18sb1+Zte20 High-Performance Thermoelectrics Elucidated By 125te And 207pb Nmr, E. M. Levin, B. A. Cook, K. Ahn, M. G. Kanatzidis, Ames Laboratory Doe

United States Department of Energy: Publications

Using magic-angle spinning ¹²⁵Te and ²⁰⁷Pb NMR, we have discovered the presence of two phases of approximately tenfold different free-electron concentration, n, in high-performance thermoelectrics Ag_1−yPb₁₈Sb_1+zTe₂₀ (“LAST-18”), proven by pairs of Knight-shifted NMR peaks and biexponential spin-lattice relaxation. The ratio of the phases is typically 2:1 with n ≈ 2 × 10¹⁹ cm⁻³ and 0.2 × 10¹⁹ cm⁻³, respectively, determined from the spin-lattice relaxation times. ¹²⁵Te NMR spectra show that both phases contain similar concentrations of Sb. The low-n component is assigned to …

Fullerene-Encapsulated Atoms In The Light Of Synchrotron Radiation, A. M. Müller, S. Schippers, D. Esteves, M. Habibi, R. A. Phaneuf, A. L. D. Kilcoyne, A. Aguilar, L. Dunsch

United States Department of Energy: Publications

Mass-selected beams of endohedral fullerene Ce@C⁺₈₂ ions, of atomic Ce^q+ ions (q=2,3,4), and of empty fullerene-cage C⁺₈₂ ions were employed to study photoionization of fullerene-encapsulated and free cerium atoms. The Ce 4d inner-shell contributions to single and double ionization of the endohedral Ce@C⁺₈₂ fullerene have been extracted from the data and compared with expectations based on theory and the experiments with atomic Ce ions. Dramatic reduction and redistribution of the ionization contributions to Ce 4d photoabsorption is observed. More than half of the Ce 4d oscillator strength is apparently diverted to …

Biofuels, Land, And Water: A Systems Approach To Sustainability, Gayathri Gopalakrishnan, M. Cristina Negri, Michael Wang, May Wu, Seth W. Snyder, Lorraine Lafreniere

United States Department of Energy: Publications

There is a strong societal need to evaluate and understand the sustainability of biofuels, especially because of the significant increases in production mandated by many countries, including the United States. Sustainability will be a strong factor in the regulatory environment and investments in biofuels. Biomass feedstock production is an important contributor to environmental, social, and economic impacts from biofuels. This study presents a systems approach where the agricultural, energy, and environmental sectors are considered as components of a single system, and environmental liabilities are used as recoverable resources for biomass feedstock production. We focus on efficient use of land and …

Doe Climate Change Research Program: Strategic Plan

United States Department of Energy: Publications

Advance the forefront of climate change research to provide the nation with the scientific knowledge it needs about the effects of greenhouse gas emissions on Earth's climate and biosphere to support effective energy and environmental decision making.

Mineralogical Transformations Controlling Acid Mine Drainage Chemistry, T. Peretyazhko, John M. Zachara, J.-F. Boily, Y. Xia, P.L. Gassman, B.W. Arey, W.D. Burgos

United States Department of Energy: Publications

The role of Fe(III) minerals in controlling acid mine drainage (AMD) chemistry was studied using samples from two AMD sites [Gum Boot (GB) and Fridays-2 (FR)] located in northern Pennsylvania. Chemical extractions, X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) were used to identify and characterize Fe(III) phases. The mineralogical analysis revealed schwertmannite and goethite as the principal Fe(III) phases in the sediments. Schwertmannite particles occurred as sub-micron sized spheroids. Their transformation into goethite occurred at the GB site where poorly-crystallized goethite rich in surface-bound sulfate was initially formed. In contrast, no schwertmannite transformation occurred …

Managing Livestock Manure To Protect Environmental Quality, Brian L. Benham, Richard B. Ferguson, Christopher G. Henry, Michael A. Reynolds, Charles A. Shapiro, James P. Stack, Charles S. Wortmann

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Proper utilization of livestock manure is a major environmental concern. Livestock manure has typically been considered a ‘waste product’ of livestock production. A more accurate name for this material is a ‘recycled resource’ from the production of livestock. By managing livestock manure, the producer has a second chance to utilize the nutrients that have already been paid for but not fully utilized by the animal. Collecting, containing, and properly spreading livestock manure will incur additional costs for the producer. However, these costs can be offset or justified by the producer in terms of the yield enhancement and nutrient credits that …

Integrated Capture And Spectroscopic Detection Of Viruses, Crystal A. Vargas, Allison A. Wilhelm, Jeremy Williams, Pierre Lucas, Kelly A. Reynolds, Mark R. Riley

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The goal of this work is to develop an online monitoring scheme for detection of viruses in flowing drinking water. The approach applies an electrodeposition process that is similar to the use of charged membrane filters previously employed for collection of viruses from aqueous samples. In the present approach, charged materials are driven onto a robust optical sensing element which has high transparency to infrared light. A spectroscopic measurement is performed using the evanescent wave that penetrates no more than 1 m from the surface of an infrared optical element in an attenuated total reflectance measurement scheme. The infrared measurement …

Optical Properties Of Coal Combustion Byproducts For Particle-Size Analysis By Laser Diffraction, Robert B. Jewell, Robert F. Rathbone

Coal Combustion and Gasification Products Journal Archive

Laser diffraction analysis is commonly used for determining the particle-size distribution (PSD) of fly ash. However, there is currently no standard method for preparing samples and analyzing them. The Mie and Fraunhofer optical models are used to calculate the PSD of fly ash from laser diffraction data. The Mie theory is most applicable for particles smaller than 50 mm, and is therefore the most accurate model for the analysis of fly ash. However, the refractive index (RI) of fly ash is complex and not well known. This study presents the analysis of several supplementary cementitious materials (SCMs) such as coal …

Development Of Novel Microwave Cooking Model For Not-Ready-To Eat Foods, Sohan Birla, Krishnamoorthy Pitchai, Jeyamkondan Subbiah, David D. Jones

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

Recently safety of microwave cooked food has come under scrutiny because of recent outbreak and recalls associated with some of these not-ready-to-eat (NRTE) frozen foods. Heating uniformity of these foods is paramount in rendering the foods safe for consumption. Degree of uneven microwave heating is influenced by both microwave oven and characteristics of food load which decides the electric field distribution within the food load. Given the complexity of parameters, a computer model is always desirable to optimize heating uniformity by proper selection of food shape, proportions, plating, packaging selection and more. Earlier many researchers have made one or more …

Farming Systems Education: Case Study Of Swedish Test Pilots, Lennart Salomonsson, Anna Nilsson, Sofia Palmer, Adam Roigart, Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

We describe and analyze a pedagogical experiment that introduced a broad and holistic perspective on complete farming systems, systemic learning tools, and a participatory learning strategy at an early stage in agronomy education. The paper describes the adventure of three students, who came from a conventional agronomy program at the Swedish University of Agricultural Sciences (SLU), who were frustrated with the lack of integrated approaches to the study of agricultural systems and a strong focus on molecular-level processes in their first year of education. They encountered a narrow focus in most courses and the overall curricula of agricultural education that …

Uranium In Framboidal Pyrite From A Naturally Bioreduced Alluvial Sediment, Nikolla P. Qafoku, Ravi K. Kukkadapu, James P. Mckinley, Bruce W, Arey, Shelly D. Kelly, Chongmin Wang, Charles T. Resch, Philip E. Long

United States Department of Energy: Publications

Samples of a naturally bioreduced, U-contaminated alluvial sediment were characterized with various microscopic and spectroscopic techniques and wet chemical extraction methods. The objective was to investigate U association and interaction with minerals of the sediment. Bioreduced sediment comprises ∼10% of an alluvial aquifer adjacent to the Colorado River, in Rifle, CO, that was the site of a former U milling operation. Past and ongoing research has demonstrated that bioreduced sediment is elevated in solid-associated U, total organic carbon, and acid-volatile sulfide, and depleted in bioavailable Fe(III) confirming that sulfate and Fe(III) reduction have occurred naturally in the sediment. SEM/EDS analyses …

Heterogeneous Reduction Of Tc(Vii) By Fe(Ii) At The Solid–Water Interface, T. Peretyazhko, John M. Zachara, S.M. Heald, B.-H. Jeon, Ravi K. Kukkadapu, C. Liu, D. Moore, C.T. Resch

United States Department of Energy: Publications

Experiments were performed herein to investigate the rates and products of heterogeneous reduction of Tc(VII) by Fe(II) adsorbed to hematite and goethite, and by Fe(II) associated with a dithionite–citrate–bicarbonate (DCB) reduced natural phyllosilicate mixture [structural, ion-exchangeable, and edge-complexed Fe(II)] containing vermiculite, illite, and muscovite. The heterogeneous reduction of Tc(VII) by Fe(II) adsorbed to the Fe(III) oxides increased with increasing pH and was coincident with a second event of Fe²⁺_(aq) adsorption. The reaction was almost instantaneous above pH 7. In contrast, the reduction rates of Tc(VII) by DCB-reduced phyllosilicates were not sensitive to pH or to added Fe^{2+ …}

Asymmetry Of Model Bin Wall Loads And Lateral Pressure Induced From Two- And Three-Dimensional Obstructions Attached To The Wall, Marek Molenda, Michael D. Montross, Sidney A. Thompson, Jozef Horabik

Biosystems and Agricultural Engineering Faculty Publications

An obstruction attached to the wall of a bin produced by cohesive, moldy grain has been reported as a source of failure in steel bins. A study was conducted to estimate the effect of two-dimensional (plane) and three-dimensional (block) obstructions attached to the corrugated wall in a flat-floor model bin where the lateral wall pressure and vertical wall loads were measured. The model bin was 1.83 m in diameter, 5.75 m high, and filled with soft red winter wheat to a depth of 5.0 m (height-to-diameter ratio h/d of 2.75). The plane obstruction had the form of an annulus segment …

Retrofitting Tractors With Rollover Protective Structures: Perspective Of Equipment Dealers, Shalome M. Tonelli, Kelley J. Donham, Kerry Leedom-Larson, Wayne Sanderson, Mark A. Purschwitz

Biosystems and Agricultural Engineering Faculty Publications

This study was one of a cluster of studies that originated via requests for proposals from the NIOSH National Agricultural Tractor Safety Initiative. The present study design consisted of several steps: (1) formation of an advisory group, (2) development and testing of a standard paper self-responding survey instrument, (3) sample selection of farm equipment dealers, (4) administration of the survey, (5) assessment and analysis of the survey, and (6) in-person response panel of dealers (n = 80) to review results of the questionnaire for further definition and sharpening of the recommendations from the survey. A key finding is that most …

Integration Of An Extended Octagonal Ring Transducer And Soil Coulterometer For Identifying Soil Compaction, Santosh K. Pitla, Larry G. Wells, Scott A. Shearer

Biosystems and Agricultural Engineering Faculty Publications

The soil coulterometer is an "on-the-go" electro-mechanical system which collects impedance force data at multiple depths using an oscillating coulter. During the initial testing (summer 2006), only vertical soil impedance force data was collected using a pressure sensor. To improve the performance of the coulterometer, an extended octagonal ring transducer was integrated into the system to collect both the horizontal and vertical impedance forces given by the soil. In the summer of 2007, data was collected using the revised sensor from a typical central Kentucky field setting in a 0.8-ha (2-acre) plot. Four passes were made with the coulterometer. Seventy …

Special Issue On Evapotranspiration Measurement And Modeling, Samuel Ortega-Farias, Suat Irmak, R. H. Cuenca

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Water availability for irrigation throughout the world has been reduced in recent years due to a combination of frequent droughts and competition for water resources among agricultural, industrial, and urban users. In addition, some major agricultural areas face moderate to significant reductions of rainfall, or changes in timing of stream flow due to changes in timing of snowmelt, as a result of global climate change. Under such conditions, sophisticated irrigation water management will be required to optimize water use efficiency and maintain sufficient levels of crop productivity and quality. A key factor to achieve these targets is the estimation of …

Regional Co2 And Latent Heat Surface Fluxes In The Southern Great Plains: Measurements, Modeling, And Scaling, W. J. Riley, Sebastien C. Biraud, Margaret S. Torn, Marc L. Fischer, David P. Billesbach, Joe A. Berry

Department of Agricultural and Biological Systems Engineering: Faculty Publications

[1] Characterizing net ecosystem exchanges (NEE) of CO2 and sensible and latent heat fluxes in heterogeneous landscapes is difficult, yet critical given expected changes in climate and land use. We report here a measurement and modeling study designed to improve our understanding of surface to atmosphere gas exchanges under very heterogeneous land cover in the mostly agricultural U.S. Southern Great Plains (SGP). We combined three years of site-level, eddy covariance measurements in several of the dominant land cover types with regional-scale climate data from the distributed Mesonet stations and Next Generation Weather Radar precipitation measurements to calibrate a land surface …

Estimating Percent Residue Cover Using The Line-Transect Method, David P. Shelton, Paul J. Jasa

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Leaving crop residue on the soil surface is one of the easiest and most cost-effective methods of reducing soil erosion. Research in Nebraska and other midwestern states has shown that leaving as little as 20 percent of the soil surface covered with crop residue can reduce soil erosion by one-half of what it would be from residue-free conditions. Greater amounts of residue cover will further reduce erosion. Many Conservation Plans specify crop residue management or residue left on the soil surface as the primary erosion control method. Generally, the amount of cover required after planting ranges from 30 percent to …

Grand Challenges For Biological Engineering, Jeong-Yeol Yoon, Mark R. Riley

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Biological engineering will play a significant role in solving many of the world's problems in medicine, agriculture, and the environment. Recently the U.S. National Academy of Engineering (NAE) released a document "Grand Challenges in Engineering," covering broad realms of human concern from sustainability, health, vulnerability and the joy of living. Biological engineers, having tools and techniques at the interface between living and non-living entities, will play a prominent role in forging a better future. The 2010 Institute of Biological Engineering (IBE) conference in Cambridge, MA, USA will address, in part, the roles of biological engineering in solving the challenges presented …

Impact Of Microclimatic Data Measured Above Maize And Grass Canopies On Penman‐Monteith Reference Evapotranspiration Calculations, Suat Irmak, Lameck O. Odhiambo

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Estimation of reference evapotranspiration (ET_ref) using measured microclimatic data and the Penman‐Monteith (PM) method provides a powerful means of quantifying actual plant evapotranspiration (ET_a) needed for use in various disciplines. When applying the PM method to estimate ET_ref, it is desirable to measure the required microclimatic data over a reference grass or alfalfa surface rather than above non‐reference surfaces. However, in reality, establishing and maintaining a reference surface for long periods of time is a difficult task. Other surface energy balance systems, such as the Bowen ratio energy balance system (BREBS), eddy covariance system, …

Special Issue On Evapotranspiration Measurement And Modeling, Samuel Ortega-Farias, Suat Irmak, R. H. Cuenca

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Water availability for irrigation throughout the world has been reduced in recent years due to a combination of frequent droughts and competition for water resources among agricultural, industrial, and urban users. In addition, some major agricultural areas face moderate to significant reductions of rainfall, or changes in timing of stream flow due to changes in timing of snowmelt, as a result of global climate change. Under such conditions, sophisticated irrigation water management will be required to optimize water use efficiency and maintain sufficient levels of crop productivity and quality. A key factor to achieve these targets is the estimation of …

Magnitude And Trends Of Reference Evapotranspiration Rates In South Central Nebraska: Daily, Monthly, Growing Season Total, And Annual Total, Suat Irmak

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Reference evapotranspiration (ET_ref ) is used to determine the actual water use (ET_a) rate for various crops and is one of the key variables that needs to be determined accurately for effective irrigation management. This extension circular provides information on the magnitude and temporal distribution of daily, monthly, annual, and growing season alfalfa-reference evapotranspiration (ET_ref)) in south central Nebraska. It also discusses why long-term average ET_ref values may not represent non-average years or be accurate enough for irrigation management.

The most common way to calculate actual crop water use (ET_a) for a …