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 …

Artificial Insemination In South American Camelids And Wild Equids, G. P. Adams, M. H. Ratto, C. W. Collins, D. R. Bergfelt

United States Environmental Protection Agency: Publications

An overview of the present status of the use of artificial insemination (AI) in South American camelids and wild equids is offered. Technical aspects of semen collection, dilution and cryopreservation have limited the development and use of AI in camelid and equid species. To-date, efficiency is low but progress has been made and viable offspring have been produced through the use of AI in domestic South American camelids using both fresh and frozen semen. The origin, composition, and function of the viscous component of camelid seminal plasma remain a mystery and an obvious area for future research. A better understanding …

The Solar Transformity Of Petroleum Fuels, S. Bastianoni, D. E. Campbell, R. Ridolfi, F. M. Pulselli

United States Environmental Protection Agency: Publications

Petroleum fuels are the primary energy basis for transportation and industry. They are almost always an important input to the economic and social activities of humanity. Emergy analyses require accurate estimates with specified uncertainty for the transformities of major energy and material inputs to economic and environmental systems. In this study, the oil refining processes in Italy and the United States were examined to estimate the transformity and specific emergy of petroleum derivatives. Based on our assumptions that petroleum derivatives are splits of a complex hydrocarbon mixture and that the emergy is split based on the fraction of energy in …

Foodweb Modeling For Polychlorinated Biphenyls (Pcbs) In The Twelvemile Creek Arm Of Lake Hartwell, South Carolina, Usa, Brenda Rashleigh, M. Craig Barber, David M. Walters

United States Environmental Protection Agency: Publications

PCBs from the Sangamo-Weston Superfund Site near Clemson, South Carolina, USA, were released into the Twelvemile Creek Arm of Lake Hartwell until the early 1990s. Monitoring data have shown that while PCB concentration in sediments declined since 1995, PCB concentrations in fish have remained elevated, e.g., largemouth bass (Micropterus salmoides) concentrations have ranged from 5 to 10 ppm. The EPA aquatic ecosystem model AQUATOX was applied to this system to better characterize foodweb dynamics that lead to biomagnification of PCBs. The model was calibrated with observed fish biomass data. Simulated PCB loading over a 12-year period provided a …

Comparing The Mutagenicity Of Toxaphene After Aging In Anoxic Soils And Accumulating In Fish, James C. Young, Anne D. Freeman, Robert M. Bruce, Douglas Williams, Keith Maruya

United States Environmental Protection Agency: Publications

A test program was conducted to evaluate the mutagenicity of toxaphene residuals extracted from aged soils and from fish collected in creeks near a toxaphene-contaminated site. The ultimate objective was to determine if the residual toxaphene congeners were more or less mutagenic than those in technical- grade toxaphene.The study showed that the mutagenicity of the bioaccumulated toxaphenecongeners in fish, expressed as colony revertants per mg of residual toxaphene, was no greater than that of technical-grade toxaphene.Themutagenicimpactofthetoxapheneresidualsinagedsoilstatistically was less than that for technical-grade toxaphene. Two specific congeners, a hexachlorobornane(labeled Hx-Sd) and a heptachlorobornane (labeled Hp-Sd), were found to accumulate over time …

Test 1955 John Deere 5055e Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Missouri River Recovery Program: From Steamboats To Barges: Missouri River Navigation

United States Army Corps of Engineers, Omaha District

Since the early 1800s, the Missouri River has been a thoroughfare for the
transportation of goods. The U.S. government began taking an active interest in Missouri River navigation in 1832, as steamboats became the preferred means of transporting goods and people. On July 3, 1832, Congress authorized channel improvements on the Missouri River. These early river improvements involved mainly addressing obstacles in the river.

Since 1912, the U.S. Army Corps of Engineers (Corps) has managed the river to
allow for modern commercial navigation and trade. This fact sheet will describe the history of navigation on the Missouri River, navigation today, …

Effects Of Aggregate Angularity On Mix Design Characteristics And Pavement Performance, Yong-Rak Kim, Leonardo T. Souza

Mid-America Transportation Center: Final Reports and Technical Briefs

This research targeted two primary purposes: to estimate current aggregate angularity test methods and to evaluate current aggregate angularity requirements in the Nebraska asphalt mixture/pavement specification. To meet the first research objective, various aggregate angularity tests were estimated with the same sets of aggregates and were compared by investigating their characteristics on testing repeatability, cost, testing time, workability, and sensitivity of test results. For the second objective, the effect of aggregate angularity on mixture performance was investigated by conducting laboratory performance tests (the uniaxial static creep test and the indirect tensile fracture energy test) of five mixes designed with different …

Signal Classification In Fading Channels Using Cyclic Spectral Analysis, Eric Like, Vasu D. Chakravarthy, Paul Ratazzi, Zhiqiang Wu

Electrical Engineering Faculty Publications

Cognitive Radio (CR), a hierarchical Dynamic Spectrum Access (DSA) model, has been considered as a strong candidate for future communication systems improving spectrum efficiency utilizing unused spectrum of opportunity. However, to ensure the effectiveness of dynamic spectrum access, accurate signal classification in fading channels at low signal to noise ratio is essential. In this paper, a hierarchical cyclostationary-based classifier is proposed to reliably identify the signal type of a wide range of unknown signals. The proposed system assumes no a priori knowledge of critical signal statistics such as carrier frequency, carrier phase, or symbol rate. The system is designed with …

Chipless Rfid Sensor Tag System With Microstrip Transmissionline Based Id Generation Schemes, Sudhir Shrestha

Doctoral Dissertations

This dissertation presents a chipless radio frequency identification (RFID) sensor tag system consisting of passive chipless RFID sensor tags and specialized reader. The chipless sensor tags are fabricated on a flexible substrate and contain an ID generation circuit, a sensor, and a microstrip antenna. The ID generation circuit consists of meandered microstrip transmission lines and uses a novel reflection and delay based ID generation scheme. The scheme, using an input RF pulse, constructs an on-off keying (OOK) or pulse position modulated (PPM) signal pattern representing a unique ID code. Two transmission lines and OOK representation are used and the generation …

Quick Test For Percent Of Deleterious Material, David Newton Richardson

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The Missouri Department of Transportation (MoDOT) is considering the replacement of its deleterious materials test method (TM-71) with test methods that are more objective. MoDOT contracted with the Missouri University of Science and Technology (Missouri S&T) to develop a system of test methods. Nine quarry/ledge samples representing seven geologic formations (four limestones and three dolomites) were supplied by MoDOT. The ledge samples represented three aggregates each for use in concrete, asphalt, and granular base. Samples with controlled contamination were also tested, bringing the total to 18. The aggregates were subjected to fifteen test methods. This data, coupled with MoDOT historical …

Graduate School Academic Catalog 2009-2010, Graduate School Of Engineering And Management, Air Force Institute Of Technology

AFIT Documents

The Graduate Catalog represents the offerings, programs, and requirements in effect at the time of publication.

Ground-Plane Quasicloaking For Free Space, Efthymios Kallos, Christos Argyropoulos, Yang Hao

Department of Electrical and Computer Engineering: Faculty Publications

Ground-plane cloak designs are presented, which minimize scattering of electromagnetic radiation from metallic objects in the visible spectrum. It is showed that simplified ground-plane cloaks made from only a few blocks of all-dielectric isotropic materials, either embedded in a background medium or in free space, can provide considerable cloaking performance while maintaining their broadband nature. A design which operates isolated in free space that cloaks radiation originating from a specified direction is also analyzed. These schemes should be much easier to be demonstrated experimentally compared to full designs.

Controlled Growth Of Carbon Nanotubes On Electrodes Under Different Bias Polarity, Yi Gao, Yunshen Zhou, W. Xiong, M. Mahjouri-Samani, M. Mitchell, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

Carbon nanotubes (CNTs) of different alignments, such as surface-bounded and vertically aligned arrays, enable applications in different fields. In this study, controlled growth of CNTs with different alignments was achieved by electrically biasing catalyzed electrodes with different polarities in a laser-assisted chemical vapor deposition process. CNT growth was suggested to be guided by the movement of electrically charged catalyst-nanoparticles under the influence of an external electric field. This discovery provides a convenient approach to control the alignment of CNT arrays for different applications.

The Impact Of Qos Constraints On The Energy Efficiency Of Fixed-Rate Wireless Transmissions, Deli Qiao, M. Cenk Gursoy, Senem Velipasalar

Department of Electrical and Computer Engineering: Faculty Publications

Transmission over wireless fading channels under quality of service (QoS) constraints is studied when only the receiver has channel side information. Being unaware of the channel conditions, transmitter is assumed to send the information at a fixed rate. Under these assumptions, a two-state (ON-OFF) transmission model is adopted, where information is transmitted reliably at a fixed rate in the ON state while no reliable transmission occurs in the OFF state. QoS limitations are imposed as constraints on buffer violation probabilities, and effective capacity formulation is used to identify the maximum throughput that a wireless channel can sustain while satisfying statistical …

Coordinated Reactive Power Control Of A Large Wind Farm And A Statcom Using Heuristic Dynamic Programming, Wei Qiao, Ronald D. Harley, Ganesh Kumar Venayagamoorthy

Department of Electrical and Computer Engineering: Faculty Publications

A novel interface neurocontroller (INC) is proposed for the coordinated reactive power control between a large wind farm equipped with doubly fed induction generators (DFIGs) and a static synchronous compensator (STATCOM). The heuristic dynamic programming (HDP) technique and radial basis function neural networks (RBFNNs) are used to design this INC. It effectively reduces the level of voltage sags as well as the over-currents in the DFIG rotor circuit during grid faults, and therefore, significantly enhances the fault ride-through capability of the wind farm. The INC also acts as a coordinated external damping controller for the wind farm and the STATCOM, …

Output Maximization Control For Dfig Wind Turbines Without Using Wind And Shaft Speed Measurements, Wei Qiao, Xiang Gong, Liyan Qu

Department of Electrical and Computer Engineering: Faculty Publications

Wind turbine generators (WTGs) are usually equipped with mechanical sensors to measure wind speed and turbine shaft rotating speed for system monitoring, control, and protection. The use of these sensors increases the cost and hardware complexity and reduces the reliability of the WTG system. This paper proposes a novel real-time speed estimation algorithm for wind turbines equipped with doubly-fed induction generators (DFIGs). In the proposed algorithm, both the wind and turbine shaft speeds are estimated from the measured DFIG output electrical power. The estimated speeds are then used to determine the maximum power point of the DFIG wind turbine. A …

Missing-Sensor-Fault-Tolerant Control For Sssc Facts Device With Real-Time Implementation, Wei Qiao, Ganesh Kumar Venayagamoorthy, Ronald G. Harley

Department of Electrical and Computer Engineering: Faculty Publications

Control of power systems relies on the availability and quality of sensor measurements. However, measurements are inevitably subjected to faults caused by sensor failure, broken or bad connections, bad communication, or malfunction of some hardware or software. These faults, in turn, may cause the failure of power system controllers and consequently, severe contingencies in the power system. To avoid such contingencies, this paper presents a sensor evaluation and (missing sensor) restoration scheme (SERS) by using auto-associative neural networks (auto encoders) and particle swarm optimization. Based on the SERS, a missing-sensor-fault-tolerant control is developed for controlling a static synchronous series compensator …

Voltage Analysis Of Distribution Systems With Dfig Wind Turbines, Baohua Dong, Sohrab Asgarpoor, Wei Qiao

Department of Electrical and Computer Engineering: Faculty Publications

Wind energy is becoming the most viable renewable energy source mainly because of the growing concerns over carbon emissions and uncertainties in fossil fuel supplies and the government policy impetus. The increasing penetration of wind power in distribution systems may significantly affect voltage stability of the systems, particularly during wind turbine cut-in and cut-off disturbances. Currently, doubly fed induction generator wind turbine (DFIG-WT) is the most popular wind turbine. This paper investigates the issues of voltage stability improvement and grid-loss reduction of distribution systems which include DFIG-WTs under unbalanced heavy loading conditions. Simulation studies are carried out in IEEE 34-bus …

Missing-Sensor-Fault-Tolerant Control For Sssc Facts Device With Real-Time Implementation, Wei Qiao, Ganesh Venayagamoorthy, Ronald G. Harley

Department of Electrical and Computer Engineering: Faculty Publications

Control of power systems relies on the availability and quality of sensor measurements. However, measurements are inevitably subjected to faults caused by sensor failure, broken or bad connections, bad communication, or malfunction of some hardware or software. These faults in turn may cause the failure of power system controllers and consequently severe contingencies in the power system. To avoid such contingencies, this paper resents a sensor evaluation and (missing sensor) restoration scheme (SERS) by using auto-associative neural networks (auto-encoders) and particle swarm optimization (PSO). Based on the SERS, a missing-sensor-fault-tolerant control (MSFTC) is developed for controlling a static synchronous series …