Bioresource and Agricultural Engineering Commons^™

Cation Exchange Reactions Controlling Desorption Of 90sr2+ From Coarse-Grained Contaminated Sediments At The Hanford Site, Washington, James Mckinley, John M. Zachara, Steven Smith, Chongxuan Liu

United States Department of Energy: Publications

Nuclear waste that bore ⁹⁰Sr²⁺ was accidentally leaked into the vadose zone at the Hanford site, and was immobilized at relatively shallow depths in sediments containing little apparent clay or silt-sized components. Sr²⁺, ⁹⁰Sr²⁺, Mg2+, and Ca²⁺ was desorbed and total inorganic carbon concentration was monitored during the equilibration of this sediment with varying concentrations of Na⁺, Ca²⁺. A cation exchange model previously developed for similar sediments was applied to these results as a predictor of final solution compositions. The model included binary exchange reactions for the four …

Geochemical Processes Controlling Migration Of Tank Wastes In Hanford’S Vadose Zone, John M. Zachara, Jeff Serne, Mark Freshley, Fred Mann, Frank Anderson, Marcus Wood, Tom Jones, Dave Myers

United States Department of Energy: Publications

Nuclear wastes from Hanford’s processing for separation of plutonium are stored in massive, buried, single-shell tanks in 18 tank farms. These so-called tank wastes were initially thermally hot because of radioactive decay, and many exhibited extreme chemical character in terms of pH, salinity, and radionuclide concentration. At present, 67 of the 149 single shell tanks are suspected to have released over 1.9 million L of tank waste to the vadose zone, with most leak events occurring between 1950 and 1975. Boreholes have been placed through the largest vadose zone plumes to define the extent of contaminant migration and to develop …

Generation Of Electron Bunches At Low Repetition Rates Using A Beat-Frequency Technique, M. Poelker, J. Grames, J. Hansknecht, R. Kazimi, J. Musson

United States Department of Energy: Publications

Even at a continuous wave facility such as CEBAF at Jefferson Lab, an electron beam with long time intervals (tens of ns) between individual bunches can be useful, for example, to isolate sources of background via time of flight detection or to measure the energy of neutral particles that cannot be separated with a magnetic field. This paper describes a demonstrated method to quickly and easily deliver bunches with repetition rates of 20 to 100 MHz corresponding to time intervals between 50 and 10 ns (respectively). This is accomplished by changing the ON/OFF frequency of the photogun drive laser by …

Small Wind Electric Systems: A Nebraska Consumer’S Guide

United States Department of Energy: Publications

Can I use wind energy to power my home? This question is being asked across the country as more people look for affordable and reliable sources of electricity. Small wind electric systems can make a significant contribution to our nation’s energy needs. Although wind turbines large enough to provide a significant portion of the electricity needed by the average U.S. home generally require one acre of property or more, approximately 21 million U.S. homes are built on one-acre and larger sites, and 24% of the U.S. population lives in rural areas.

A small wind electric system will work for you …

Geochemical Controls On Contaminant Uranium In Vadose Hanford Formation Sediments At The 200 Area And 300 Area, Hanford Site, Washington, James Mckinley, John M. Zachara, Jiamin Wan, David Mccready, Steven M. Heald

United States Department of Energy: Publications

Long-term historic spills of uranium at the 300 Area fuel fabrication site (58,000 kg of disposed uranium over 32 yr) and at the 200 East Area BX tank farm (7000 kg of spilled uranium in one event), both within the Hanford formation in the Hanford Site, Washington State, were investigated by subsurface sampling and subsequent microscale investigations of excavated samples. The 200 Area sediments contained uranyl silicate mineralization (sodium boltwoodite) in restrictive microfractures in granitic clasts, in the vadose zone over a narrow range in depth. Well logging and column experiments indicated that tank wastes migrated deeper than observed in …

Hanford Site Vadose Zone Studies: An Overview, G. W. Gee, M. Oostrom, M. D. Freshley, M. L. Rockhold, John M. Zachara

United States Department of Energy: Publications

Large quantities of radioactive and chemical wastes resulting from Pu production for nuclear weapons are located in the vadose zone at the USDOE’s Hanford Site, north of Richland, WA. The vadose zone here is characterized by often highly stratified glacial-fluvial sediments that give rise to complex subsurface-flow paths that contribute to uncertainty of contaminant fate and transport. Research efforts have focused on answering questions of contaminant transport from the viewpoint of geologic, biologic, geochemical, and hydrologic controls. This special section highlights key research topics concerning vadose zone problems at the Hanford Site. Research indicates that some of the contaminant species …

Development Of A High Average Current Polarized Electron Source With Long Cathode Operational Lifetime, C. K. Sinclair, P. Adderley, B. M. Dunham, J. C. Hansknecht, P. Hartmann, M. Poelker, J. S. Price, P. M. Rutt, W. J. Schneider, M. Steigerwald

United States Department of Energy: Publications

Substantially more than half of the electromagnetic nuclear physics experiments conducted at the Continuous Electron Beam Accelerator Facility of the Thomas Jefferson National Accelerator Facility (Jefferson Laboratory) require highly polarized electron beams, often at high average current. Spinpolarized electrons are produced by photoemission from various GaAs-based semiconductor photocathodes, using circularly polarized laser light with photon energy slightly larger than the semiconductor band gap. The photocathodes are prepared by activation of the clean semiconductor surface to negative electron affinity using cesium and oxidation. Historically, in many laboratories worldwide, these photocathodes have had short operational lifetimes at high average current, and have …

Photoionization And Electron-Impact Ionization Of Ar5+, Jing Cheng Wang, M. Lu, D. A. Esteves, M. Habibi, G. Alna’Washi, R. A. Phaneuf, A. L. D. Kilcoyne

United States Department of Energy: Publications

Absolute cross sections for photoionization and electron-impact ionization of Ar⁵⁺ have been measured using two different interacting-beams setups. The spectra consist of measurements of the yield of products due to single ionization as a function of electron or photon energy. In addition, absolute photoionization and electron-impact ionization cross sections were measured to normalize the measured Ar⁶⁺ product-ion yield spectra. In the energy range from 90 to 111 eV, both electron-impact ionization and photoionization of Ar⁵⁺ are dominated by indirect 3s subshell excitation-autoionization. In the energy range from 270 to 285 eV, resonances due to 2p …

Convergence Of Peridynamics To Classical Elasticity Theory, S. A. Silling, R. B. Lehoucq

United States Department of Energy: Publications

The peridynamic model of solid mechanics is a nonlocal theory containing a length scale. It is based on direct interactions between points in a continuum separated from each other by a finite distance. The maximum interaction distance provides a length scale for the material model. This paper addresses the question of whether the peridynamic model for an elastic material reproduces the classical local model as this length scale goes to zero. We show that if the motion, constitutive model, and any nonhomogeneities are sufficiently smooth, then the peridynamic stress tensor converges in this limit to a Piola-Kirchhoff stress tensor that …

Uranium(Vi) Release From Contaminated Vadose Zone Sediments: Estimation Of Potential Contributions From Dissolution And Desorption, Deborah L. Bond, James A. Davis, John M. Zachara

United States Department of Energy: Publications

A key difficulty in developing accurate, science-based conceptual models for remediation of contaminated field sites is the proper accounting of multiple coupled geochemical and hydrologic processes. An example of such a difficulty is the separation of desorption and dissolution processes in releasing contaminants from sediments to groundwaters; very few studies are found in the literature that attempt to quantify contaminant release by these two processes. In this study, the results from several extraction techniques, isotopic exchange experiments, and published spectroscopic studies were combined to estimate the contributions of desorption and dissolution to U(VI) release from contaminated sediments collected from the …

Kinetics Of Reductive Dissolution Of Hematite By Bioreduced Anthraquinone-2,6-Disulfonate, Chongxuan Liu, John M. Zachara, Nancy Foster, Janae Strickland

United States Department of Energy: Publications

The reductive dissolution of hematite (α-Fe₂O₃) was investigated in a flow-through system using AH2DS, a reduced form of anthraquinone-2,6-disulfonate (AQDS), which is often used as a model electron shuttling compound in studies of dissimilatory microbial reduction of iron oxides. Influent flow rate, pH, and Fe(II) and phosphate concentrations were varied to investigate the redox kinetics in a flow-through reactor. The hematite reduction rates decreased with increasing pH from 4.5 to 7.6 and decreased with decreasing flow rate. The rates also decreased with increasing influent concentration of Fe(II) or phosphate that formed surface complexes at the experimental …

Respiration Of Metal (Hydr)Oxides By Shewanella And Geobacter: A Key Role For Multihaem C-Type Cytochromes, Liang Shi, Thomas C. Squier, John M. Zachara, James K. Fredrickson

United States Department of Energy: Publications

Dissimilatory reduction of metal (e.g. Fe, Mn) (hydr)oxides represents a challenge for microorganisms, as their cell envelopes are impermeable to metal (hydr)oxides that are poorly soluble in water. To overcome this physical barrier, the Gram-negative bacteria Shewanella oneidensis MR-1 and Geobacter sulfurreducens have developed electron transfer (ET) strategies that require multihaem c-type cytochromes (c-Cyts). In S. oneidensis MR-1, multihaem c-Cyts CymA and MtrA are believed to transfer electrons from the inner membrane quinone/quinol pool through the periplasm to the outer membrane. The type II secretion system of S. oneidensis MR-1 has been implicated in the reduction of metal …

Dust Emission From South Dakota Cattle Feedlots, Rick Weber

The Journal of Undergraduate Research

Dust and particle emissions (PM) from cattle feedlots is a concern for producers in order to maintain good relations with neighbors and also to comply with the EPA proposed PM_2.5 particulate emission rules. Dust at 2.5 microns, which cannot be seen by the naked eye, is a potential health hazard since it can be ingested into the lungs of humans. One of the proposed regulations of the Federal Clean Air Act is to apply the PM_2.5 standard to the agricultural sector. This research project examines the particulate matter dust emissions of various sizes in microns including 2.5, 10, …

Economic Analysis Of Cellulase Production Methods For Bio-Ethanol, Jun Zhuang, Mary A. Marchant, Sue E. Nokes, Herbert J. Strobel

Biosystems and Agricultural Engineering Faculty Publications

The cost of cellulase enzymes has limited the feasibility of producing ethanol from fibrous biomass. Traditional submerged fermentation (SmF) was compared to an alternative method of producing cellulase, solid state cultivation (SSC). Results from an economic analysis indicated that the unit costs for cellulase enzyme production were $15.67 (The prices are all 2004 prices in this article, except otherwise stated. We deflated newer prices to 2004 prices using a deflation factor 0.9 per year and inflated older prices to 2004 prices using an inflation factor 1.1.) per kilogram ($/kg) and $40.36/kg, for the SSC and SmF methods, respectively, while the …

Anaerobic Digestion: Decision Support Software, Marco Poliafico

Theses

Ireland has significant quantities of livestock; meat exportation is a vibrant sector of the economy. Environmental management of animal wastes has therefore become an important concern. On the other hand in the last decade, national and EU policy debate has highlighted the need to investigate alternative energy: in particular energy for transport.

This study investigates the quantities of animal wastes produced in Ireland and their potential treatment using Anaerobic Digestion technologies. In 2005 Ireland had over 8 millions animals (cattle and pigs) and the annual slaughter accounted for over 4.2 million of these creatures. These animals have been responsible for …

Discrimination Of Bacteria And Bacteriophages By Raman Spectroscopy And Surface-Enhanced Raman Spectroscopy, Lindsay J. Goeller, Mark R. Riley

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Detection of pathogenic organisms in the environment presents several challenges due to the high cost and long times typically required for identification and quantification. Polymerase chain reaction (PCR) based methods are often hindered by the presence of polymerase inhibiting compounds and so direct methods of quantification that do not require enrichment or amplification are being sought. This work presents an analysis of pathogen detection using Raman spectroscopy to identify and quantify microorganisms without drying. Confocal Raman measurements of the bacterium Escherichia coli and of two bacteriophages, MS2 and PRD1, were analyzed for characteristic peaks and to estimate detection limits using …

Introducing Journal Of Biological Engineering, Mark R. Riley

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Welcome to Journal of Biological Engineering (JBE), the flagship publication of the Institute of Biological Engineering. Biological Engineering is a new and unique discipline that encompasses a wide range of engineering theory and practice connected to and derived from biology. This emerging science-based engineering discipline and related applications are experiencing rapid growth. Prior to publication of JBE there is no refereed publication that encompasses the breadth and depth of biological engineering as a science- based discipline, rather than a collection of applications. Our goal in publishing JBE is to provide a forum for topics that address the foundational …

Biocompatibility Of Te–As–Se Glass Fibers For Cell-Based Bio-Optic Infrared Sensors, Allison A. Wilhelm, Pierre Lucas, Diana L. Derosa, Mark R. Riley

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The chemical stability and toxicity of Te–As–Se (TAS) infrared fibers are investigated. These fibers are used for biosensing applications that involve direct contact with live cultivated human cells. It is shown that TAS fibers exhibit a small oxidation layer after extended exposure to air. This layer is highly soluble in water and easily removed. However, the TAS glass itself is stable in water over several days. While oxidized fibers release arsenate ions, which result in toxic effects to the cells, fresh or washed fibers show no toxic effects. A good correlation is shown between surface etching and the disappearance of …

Subsurface Characterization Using Textural Features Extracted From Gpr Data, R. S. Freeland, Lameck O. Odhiambo

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Subsurface conditions can be non-intrusively mapped by observing and grouping patterns of similarity within ground-penetrating radar (GPR) profiles. We have observed that the intricate and often visually indiscernible textural variability found within a complex GPR image possesses important parameters that help delineate regions of similar subsurface characteristics. In this study, we therefore examined the feasibility of using textural features extracted from GPR data to automate subsurface characterization. The textural features were matched to a “fingerprint” database of previous subsurface classifications of GPR textural features and the corresponding physical probings of subsurface conditions. Four textural features (energy, contrast, entropy, and homogeneity) …

Analysis Of An Ion‐Selective Electrode Based Methodology For Integrated On‐The‐Go Mapping Of Soil Ph, Potassium, And Nitrate Contents, B. Sethuramasamyraja, V. I. Adamchuk, D. B. Marx, A. Dobermann, G. E. Meyer, D. D. Jones

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Knowledge of the spatial variation of soil attributes is critical for precision agriculture. On‐the‐go soil sensors have been able to provide relatively high mapping density while assessing this variation. A new ion‐selective electrode (ISE) based approach was developed and tested for simultaneous mapping of soil pH, residual nitrate (NO3 -), and soluble potassium (K+) contents. In this article, results of laboratory experiments investigating the effects of key measurement factors on ISE performance are presented. In addition to four different soils, these factors included: soil/water ratio (SWR), quality of water used for electrode rinsing (QWR) and for …

Spatiotemporal Variations In Growing Season Exchanges Of Co2, H2o, And Sensible Heat In Agricultural Fields Of The Southern Great Plains, Marc L. Fischer, Dave P. Billesbach, Joseph A. Berry, William J. Riley, Margaret S. Torn

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Climate, vegetation cover, and management create finescale heterogeneity in unirrigated agricultural regions, with important but not well quantified consequences for spatial and temporal variations in surface CO2, water, and heat fluxes. Eddy covariance fluxes were measured in seven agricultural fields—comprising winter wheat, pasture, and sorghum—in the U.S. Southern Great Plains (SGP) during the 2001–03 growing seasons. Land cover was the dominant source of variation in surface fluxes, with 50%–100% differences between fields planted in winter–spring versus fields planted in summer. Interannual variation was driven mainly by precipitation, which varied more than twofold between years. Peak aboveground biomass and growing season …

Pyrene Mineralization By Mycobacterium Sp. Strain Kms In A Barley Rhizosphere, R. Child, C. Miller, Y. Liang, Ronald C. Sims, A. J. Anderson

Biological Engineering Faculty Publications

To determine whether the soil Mycobacterium isolate KMS would mineralize pyrene under rhizosphere conditions, a microcosm system was established to collect radioactive carbon dioxide released from the labeled polycyclic aromatic hydrocarbon. Microcosms were designed as sealed, flow-through systems that allowed the growth of plants. Experiments were conducted to evaluate mineralization of ¹⁴C-labeled pyrene in a sand amended with the polycyclic aromatic hydrocarbons degrading Mycobacterium isolate KMS, barley plants, or barley plants with roots colonized by isolate KMS. Mineralization was quantified by collecting the ¹⁴CO₂ produced from ¹⁴C-labeled pyrene at intervals during the 10-d incubation period. Roots …

Temperature Effect On Tert-Butyl Alcohol (Tba) Biodegradation Kinetics In Hyporheic Zone Soils, M. H. Greenwood, Ronald C. Sims, J. E. Mclean, W. J. Doucette

Biological Engineering Faculty Publications

Background

Remediation of tert-butyl alcohol (TBA) in subsurface waters should be taken into consideration at reformulated gasoline contaminated sites since it is a biodegradation intermediate of methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), and tert-butyl formate (TBF). The effect of temperature on TBA biodegradation has not been not been published in the literature.

Methods

Biodegradation of [U ¹⁴C] TBA was determined using hyporheic zone soil microcosms.

Results

First order mineralization rate constants of TBA at 5°C, 15°C and 25°C were 7.84 ± 0.14 × 10^-3, 9.07 ± 0.09 × 10^-3, and 15.3 ± 0.3 …

Theory And Application Of Landfarming To Remediate Pahs And Mineral Oil Contaminated Sediments: Beneficial Reuse, J. Harmsen, W. Rulkens, Ronald C. Sims, P. Ritjema, A. Zweers

Biological Engineering Faculty Publications

When applying landfarming for the remediation of contaminated soil and sediment, a fraction of the soil-bound contaminant is rapidly degraded; however, a residual concentration may remain, which slowly degrades. Degradation of polycyclic aromatic hydrocarbons (PAHs) and mineral oil can be described using a multi-compartment model and first-order kinetics, in which three degradable fractions are distinguished; (1) rapid, (2) slowly, and (3) very slowly degradable. Using this model populated with data from long-term experiments (initiated in 1990), it is shown that time frames from years to decades can be necessary to clean the soil or sediment to obtain a target below …