National Library of Energy BETA

Sample records for granular zero-valent iron

  1. Degradation of organic and inorganic contaminants by zero valent iron 

    E-Print Network [OSTI]

    Malla, Deepak Babu

    1997-01-01

    Reduction of trichloroethylene (TCE), chromium (VI), and 2,4 dinitrotoluene (2,4-DNT) by zero valent iron and palladized iron under anaerobic conditions was investigated. Reduction experiments of the contaminants were carried out individually...

  2. Electrochemical deposition of green rust on zero-valent iron 

    E-Print Network [OSTI]

    Kulkarni, Dhananjay Vijay

    2006-08-16

    Perchloroethylene (PCE) is a toxic contaminant that has been introduced into the environment over many years through industrial and agricultural wastes. Research has been done in the past to investigate PCE degradation by zero-valent iron (ZVI...

  3. Chromate transport through columns packed with surfactant-modified zeolite/zero valent iron pellets

    E-Print Network [OSTI]

    Li, Zhaohui

    Chromate transport through columns packed with surfactant-modified zeolite/zero valent iron pellets Chromate transport through columns packed with zeolite/zero valent iron (Z/ZVI) pellets, either untreated originated from chromate sorption onto the HDTMA modified Z/ZVI pellets. Due to dual porosity, the presence

  4. Reduction of Aromatic Hydrocarbons by Zero-Valent Iron and Palladium Catalyst

    SciTech Connect (OSTI)

    Kim, Young-Hun; Shin, Won Sik; Ko, Seok-Oh; Kim, Myung-Chul

    2004-03-31

    Permeable reactive barrier (PRB) is an alternative technology for soil and groundwater remediation. Zero valent iron, which is the most popular PRB material, is only applicable to halogenated aliphatic organics and some heavy metals. The objective of this study was to investigate reductive dechlorination of halogenated compounds and reduction of non-halogenated aromatic hydrocarbons using zero valent metals (ZVMs) and catalysts as reactive materials for PRBs. A group of small aromatic hydrocarbons such as monochlorophenols, phenol and benzene were readily reduced with palladium catalyst and zero valent iron. Poly-aromatic hydrocarbons (PAHs) were also tested with the catalysts and zero valent metal combinations. The aromatic rings were reduced and partly reduced PAHs were found as the daughter compounds. The current study demonstrates reduction of aromatic compounds by ZVMs and modified catalysts and implicates that PRB is applicable not only for halogenated organic compounds but nonhalogenated aromatic compounds such as PAHs.

  5. Bench Scale Application of the Hybridized Zero Valent Iron Process for the Removal of Dissolved Silica From Water 

    E-Print Network [OSTI]

    Morar, Nilesh Mohan

    2014-11-12

    is effective. A more robust and cost-effective dissolved silica removal technique is desirable. The hybridized zero-valent iron (hZVI) process, now commercially available as Pironox™, uses zero-valent iron (Fe^0 ) as its main reactive media developed to remove...

  6. Reduction and Immobilization of Radionuclides and Toxic Metal Ions Using Combined Zero Valent Iron and Anaerobic Bacteria

    SciTech Connect (OSTI)

    Lenly J. Weathers; Lynn E. Katz

    2002-05-29

    The use of zero valent iron, permeable reactive barriers (PRBs) for groundwater remediation continues to increase. AN exciting variation of this technology involves introducing anaerobic bacteria into these barriers so that both biological and abiotic pollutant removal processes are functional. This work evaluated the hypothesis that a system combining a mixed culture of sulfate reducing bacteria (SRB) with zero valent iron would have a greater cr(VI) removal efficiency and a greater total Cr(VI) removal capacity than a zero valent iron system without the microorganisms. Hence, the overall goal of this research was to compare the performance of these types of systems with regard to their Cr(VI) removal efficiency and total Cr(VI) removal capacity. Both batch and continuous flow reactor systems were evaluated.

  7. Calcite precipitation dominates the electrical signatures of zero valent iron columns under simulated field conditions

    SciTech Connect (OSTI)

    Wu, Yuxin; Versteeg, R.; Slater, L.; LaBrecque, D.

    2009-06-01

    Calcium carbonate is a secondary mineral precipitate influencing zero valent iron (ZVI) barrier reactivity and hydraulic performance. We conducted column experiments to investigate electrical signatures resulting from concurrent CaCO{sub 3} and iron oxides precipitation under simulated field geochemical conditions. We identified CaCO{sub 3} as a major mineral phase throughout the columns, with magnetite present primarily close to the influent based on XRD analysis. Electrical measurements revealed decreases in conductivity and polarization of both columns, suggesting that electrically insulating CaCO{sub 3} dominates the electrical response despite the presence of electrically conductive iron oxides. SEM/EDX imaging suggests that the electrical signal reflects the geometrical arrangement of the mineral phases. CaCO{sub 3} forms insulating films on ZVI/magnetite surfaces, restricting charge transfer between the pore electrolyte and ZVI particles, as well as across interconnected ZVI particles. As surface reactivity also depends on the ability of the surface to engage in redox reactions via charge transfer, electrical measurements may provide a minimally invasive technology for monitoring reactivity loss due to CaCO{sub 3} precipitation. Comparison between laboratory and field data shows consistent changes in electrical signatures due to iron corrosion and secondary mineral precipitation.

  8. An Experimental Study of Micron-Size Zero-Valent Iron Emplacement in Permeable Porous Media Using Polymer-Enhanced Fluids

    SciTech Connect (OSTI)

    Oostrom, Mart; Wietsma, Thomas W.; Covert, Matthew A.; Vermeul, Vince R.

    2005-12-22

    At the Hanford Site, an extensive In Situ Redox Manipulation (ISRM) permeable reactive barrier was installed to prevent chromate from reaching the Columbia River. However, chromium has been detected in several wells, indicating a premature loss of the reductive capacity in the aquifer. One possible cause for premature chromate breakthrough is associated with the presence of high-permeability zones in the aquifer. In these zones, groundwater moves relatively fast and is able to oxidize iron more rapidly. There is also a possibility that the high-permeability flow paths are deficient in reducing equivalents (e.g. reactive iron), required for barrier performance. One way enhancement of the current barrier reductive capacity can be achieved is by the addition of micron-scale zero-valent iron to the high-permeability zones within the aquifer. The potential emplacement of zero-valent iron (Fe0) into high-permeability Hanford sediments (Ringold Unit E gravels) using shear-thinning fluids containing polymers was investigated in three-dimensional wedge-shaped aquifer models. Polymers were used to create a suspension viscous enough to keep the Fe0 in solution for extended time periods to improve colloid movement into the porous media without causing a permanent detrimental decrease in hydraulic conductivity. Porous media were packed in the wedge-shaped flow cell to create either a heterogeneous layered system with a high-permeability zone in between two low-permeability zones or a high-permeability channel surrounded by low-permeability materials. The injection flow rate, polymer type, polymer concentration, and injected pore volumes were determined based on preliminary short- and long-column experiments.

  9. Performance of a Permeable Reactive Barrier Using Granular Zero-Valent

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterested PartiesBuilding energy codes havePUBLICofPatricia A.Crowns|26,Uranium

  10. Chemical Reduction of PCE by Zero Valent Iron Colloids Batch and Column Experiments

    E-Print Network [OSTI]

    Cirpka, Olaf Arie

    -Tests: Source Remediation Partners · Undesired side reaction between nZVI and water: anaerobic corrosion Loss also in greater depth and underneath buildings - Applicable to large range of contaminants (chlorinated hydrocarbons, heavy metals, pesticides etc.) NAPASAN-Particle Flakes D50 = 900 nm aS = 1.3 m²/g Thickness ~ 70

  11. Dechlorination of PCE by mixtures of green rust and zero-valent iron 

    E-Print Network [OSTI]

    Marchal, Fabienne

    2002-01-01

    Chlorinated compounds are toxic environmental contaminants that have been used for industrial and agricultural purposes. Research has been conducted on abiotic dechlorination of tetrachloroethylene (PCE) by sulfate green rust (GR[S]??) and zero...

  12. Calcite precipitation dominates the electrical signatures of zero valent iron columns under simulated field conditions

    E-Print Network [OSTI]

    Wu, Yuxin

    2009-01-01

    S. , 1998. Reductive precipitation of uranium(VI) by zero-W. , 2003. Predicting the precipitation of mineral phases inT.M. , 1999. Mineral precipitation and porosity losses in

  13. Dispersivity Testing of Zero-Valent Iron Treatment Cells: Monticello, Utah,

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:FinancingPetroleum Based| Department8,Department of Energy2EM's CleanupPower »

  14. Third (March 2006) Coring and Analysis of Zero-Valent Iron Permeable

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankADVANCEDInstallers/ContractorsPhotovoltaicsState ofSavings for Specific2 DOEThermoelectrics:Thinking

  15. Removal of Selenium from Wastewater using ZVI and Hybrid ZVI/Iron Oxide Process 

    E-Print Network [OSTI]

    Yang, Zhen

    2012-12-20

    CN- treatment. Zero-valent iron (ZVI) technology, with some successes in remediating toxic-metal contaminated groundwater remediation, emerges as a potential solution for addressing SeCN- problem. In this study, bench scale tests were conducted to investigate...

  16. Separating the Kinetic and Sorption Parameters of Mixed Chlorinated Solvents in Contact with Granular Iron

    E-Print Network [OSTI]

    Huang, Bei

    2011-08-31

    , validating the methodology. Finally, the activation energy of the 4-chloronitrobenzene reacting with two types of granular iron, Connelly iron and QMP, in batch reactors was obtained to assess the role of mass transfer in controlling the kinetics. Previous...

  17. Conversion of Steel Mill's Surface Waste into Zero Valent Iron (ZVI) Nanoparticles for Hydrogen Generation for PEMFCs

    E-Print Network [OSTI]

    Azad, Abdul-Majeed

    Generation for PEMFCs Sathees Kumar Kesavan* and Abdul-Majeed Azad Department of Chemical and Environmental@eng.utoledo.edu The proton exchange membrane fuel cells (PEMFCs) are the most preferred and efficient energy conversion devices for automotive applications. PEMFCs demand high purity hydrogen which comes at a premium price

  18. Factors Affecting the Reactvity of Granular Iron in contact with Chlorinated Solvents

    E-Print Network [OSTI]

    Firdous, Rubina

    2013-12-31

    to magnetite (Fe3O4) (Odziemkowski et al., 1998; Pourbaix, 1973; Reardon, 1995) which occurs as the dominant corrosion product on the iron surface under anaerobic conditions (equation 1.8). 3??????? ? ??? ?? ? ?? ? 2??? 1.8 Magnetite (Fe3O4) acts...

  19. Transport in granular systems

    E-Print Network [OSTI]

    Wendell, Dawn M. (Dawn Marie), 1983-

    2011-01-01

    There are many situations in which a continuum view of granular systems does not fully capture the relevant mechanics. In order for engineers to be able to design systems for transporting granular materials, there needs ...

  20. Forced Granular Orifice Flow

    E-Print Network [OSTI]

    Zheng Peng; Hepeng Zheng; Yimin Jiang

    2009-09-06

    The flow of granular material through an orifice is studied experimentally as a function of force $F$ pushing the flow. It is found that the flow rate increases linearly with $F$ -- a new, unexpected result that is in contrast to the usual view that $F$, completely screened by an arch formed around the orifice, has no way of altering the rate. Employing energy balance, we show that this behavior results mainly from dissipation in the granular material.

  1. Coarsening in granular systems

    E-Print Network [OSTI]

    Andrea Baldassarri; Andrea Puglisi; Alessandro Sarracino

    2015-04-28

    We review a few representative examples of granular experiments or models where phase separation, accompanied by domain coarsening, is a relevant phenomenon. We first elucidate the intrinsic non-equilibrium, or athermal, nature of granular media. Thereafter, dilute systems, the so-called "granular gases" are discussed: idealized kinetic models, such as the gas of inelastic hard spheres in the cooling regime, are the optimal playground to study the slow growth of correlated structures, e.g. shear patterns, vortices and clusters. In fluidized experiments, liquid-gas or solid-gas separations have been observed. In the case of monolayers of particles, phase coexistence and coarsening appear in several different setups, with mechanical or electrostatic energy input. Phenomenological models describe, even quantitatively, several experimental measures, both for the coarsening dynamics and for the dynamic transition between different granular phases. The origin of the underlying bistability is in general related to negative compressibility from granular hydrodynamics computations, even if the understanding of the mechanism is far from complete. A relevant problem, with important industrial applications, is related to the demixing or segregation of mixtures, for instance in rotating tumblers or on horizontally vibrated plates. Finally, the problem of compaction of highly dense granular materials, which has many important applications, is usually described in terms of coarsening dynamics: there, bubbles of mis-aligned grains evaporate, allowing the coalescence of optimally arranged islands and a progressive reduction of total occupied volume.

  2. Multiscale modeling in granular flow

    E-Print Network [OSTI]

    Rycroft, Christopher Harley

    2007-01-01

    Granular materials are common in everyday experience, but have long-resisted a complete theoretical description. Here, we consider the regime of slow, dense granular flow, for which there is no general model, representing ...

  3. Perchlorate reduction using electrochemically induced pitting corrosion of zero-valent titanium 

    E-Print Network [OSTI]

    Lee, Chun Woo

    2009-05-15

    Perchlorate is a threat to public health through water but also food. However, there is no effective chemical treatment process which can destroy perchlorate found in groundwater and surface water. Thus, there is growing ...

  4. Field Projects: Cañon City, Colorado

    Broader source: Energy.gov [DOE]

    In June 2000, Cotter Corporation installed a PRB at its uranium ore processing millsite in Cañon City, Colorado. The PRB contains zero-valent iron (ZVI) that treated molybdenum and uranium...

  5. Field Projects: Monticello, Utah

    Broader source: Energy.gov [DOE]

    A permeable reactive barrier (PRB) of zero-valent iron is helping to clean up groundwater at a former uranium and vanadium ore processing mill at Monticello, Utah. LM managed remediation of...

  6. Water Resources Center Annual Technical Report

    E-Print Network [OSTI]

    . A. Arnold, and R. L. Penn. 2011. Zero Valent Iron: Impact of Anions Present During Synthesis of Goethite During the Reduction of Nitroaromatics. Goldschmidt 2011, Prague, Czech Republich, August 14

  7. Pilot-Scale Demonstration of hZVI Process for Treating Flue Gas Desulfurization Wastewater at Plant Wansley, Carrollton, GA 

    E-Print Network [OSTI]

    Peddi, Phani 1987-

    2011-12-06

    The hybrid Zero Valent Iron (hZVI) process is a novel chemical treatment platform that has shown great potential in our previous bench-scale tests for removing selenium, mercury and other pollutants from Flue Gas Desulfurization (FGD) wastewater...

  8. Lyapunov spectrum of granular gases

    SciTech Connect (OSTI)

    McNamara, Sean; Mareschal, Michel

    2001-06-01

    We calculate and study the Lyapunov spectrum of a granular gas maintained in a steady state by an isokinetic thermostat. Considering restitution coefficients greater than unity allows us to show that the spectra change smoothly and continuously at equilibrium. The shearing instability of the granular gas, however, provokes an abrupt change in the structure of the spectrum. The relationship between various physically relevant quantities and the energy dissipation rate differs from previously studied nonequilibrium steady states.

  9. On impinging near-field granular jets

    E-Print Network [OSTI]

    Arbelaez, D.; Zohdi, T. I.; Dornfeld, D. A.

    2009-01-01

    evolution models in abrasive jet micromachining. Wear 2008;SIMULATION OF GRANULAR JETS 26. Cheng X, Varas G, Citron D,behavior in a granular jet: emergence of a liquid with zero

  10. HYPERELASTIC MODELS FOR GRANULAR MATERIALS

    SciTech Connect (OSTI)

    Humrickhouse, Paul W; Corradini, Michael L

    2009-01-29

    A continuum framework for modeling of dust mobilization and transport, and the behavior of granular systems in general, has been reviewed, developed and evaluated for reactor design applications. The large quantities of micron-sized particles expected in the international fusion reactor design, ITER, will accumulate into piles and layers on surfaces, which are large relative to the individual particle size; thus, particle-particle, rather than particle-surface, interactions will determine the behavior of the material in bulk, and a continuum approach is necessary and justified in treating the phenomena of interest; e.g., particle resuspension and transport. The various constitutive relations that characterize these solid particle interactions in dense granular flows have been discussed previously, but prior to mobilization their behavior is not even fluid. Even in the absence of adhesive forces between particles, dust or sand piles can exist in static equilibrium under gravity and other forces, e.g., fluid shear. Their behavior is understood to be elastic, though not linear. The recent “granular elasticity” theory proposes a non-linear elastic model based on “Hertz contacts” between particles; the theory identifies the Coulomb yield condition as a requirement for thermodynamic stability, and has successfully reproduced experimental results for stress distributions in sand piles. The granular elasticity theory is developed and implemented in a stand- alone model and then implemented as part of a finite element model, ABAQUS, to determine the stress distributions in dust piles subjected to shear by a fluid flow. We identify yield with the onset of mobilization, and establish, for a given dust pile and flow geometry, the threshold pressure (force) conditions on the surface due to flow required to initiate it. While the granular elasticity theory applies strictly to cohesionless granular materials, attractive forces are clearly important in the interaction of micron-sized particles; extension of the theory to account for these effects is also considered. A set of continuum models are proposed for use in the future dust transport modeling.

  11. Momentum Transport in Granular Flows

    E-Print Network [OSTI]

    Gregg Lois; Anael Lemaitre; Jean M. Carlson

    2006-02-10

    We investigate the error induced by only considering binary collisions in the momentum transport of hard-sphere granular materials, as is done in kinetic theories. In this process, we first present a general microscopic derivation of the momentum transport equation and compare it to the kinetic theory derivation, which relies on the binary collision assumption. These two derivations yield different microscopic expressions for the stress tensor, which we compare using simulations. This provides a quantitative bound on the regime where binary collisions dominate momentum transport and reveals that most realistic granular flows occur in the region of phase space where the binary collision assumption does not apply.

  12. Investigating the potential for long-term permeable reactive barrier (PRB) monitoring from the electrical signatures associated with the reduction in reactive iron performance

    SciTech Connect (OSTI)

    Slater, Lee D.; Korte, N.; Baker, J.

    2005-12-14

    The objective of this work was to conduct laboratory and field experiments to determine the sensitivity of low frequency electrical measurements (resistivity and induced polarization) to the processes of corrosion and precipitation that are believed to limit permeable reactive barrier (PRB) performance. The research was divided into four sets of experiments that were each written up and submitted to a peer-reviewed journal: [1] A laboratory experiment to define the controls of aqueous chemistry (electrolyte activity; pH; valence) and total zero valent iron (Fe0) available surface area on the electrical properties of Fe0 columns. [2] A laboratory experiment to determine the impact of corrosion and precipitation on the electrical response of synthetic Fe0 columns as a result of geochemical reactions with NaSO4 and NaCO3 electrolytes. [3] Laboratory experiments on a sequence of cores retrieved from the Kansas City PRB to determine the magnitude of electrical and geochemical changes within a field active PRB after eight years of operation [4] Field-scale cross borehole resistivity and induced polarization monitoring of the Kansas City PRB to evaluate the potential of electrical imaging as a technology for non-invasive, long-term monitoring of indicators of reduced PRB performance This report first summarizes the findings of the four major experiments conducted under this research. The reader is referred to the four papers in Appendices 1-4 for a full description of each experiment, including motivation and significance, technical details, findings and implications. The deliverables of the project, including the publications, conference papers and new collaborative arrangements that have resulted are then described. Appendices 5-6 contain two technical reports written by co-PI Korte describing (1) supporting geochemical measurements, and (2) the coring procedure, conducted at the Kansas City PRB as part of this project.

  13. Shock wave propagation in vibrofluidized granular materials

    E-Print Network [OSTI]

    Kai Huang; Guoqing Miao; Peng Zhang; Yi Yun; Rongjue Wei

    2005-11-29

    Shock wave formation and propagation in two-dimensional granular materials under vertical vibration are studied by digital high speed photography. The steepen density and temperature wave fronts form near the plate as granular layer collides with vibrating plate and propagate upward through the layer. The temperature front is always in the transition region between the upward and downward granular flows. The effects of driving parameters and particle number on the shock are also explored.

  14. Rheological properties of dense granular flows

    E-Print Network [OSTI]

    Pierre Jop

    2015-03-18

    Recent progresses in understanding the behavior of dense granular flows are presented. After presenting a bulk rheology of granular materials, I focus on the new developments to account for non-local effects, and on ongoing research concerning the surface rheology and the evolution of mechanical properties for heterogeneous systems.

  15. Chaoticity of the Wet Granular Gas

    E-Print Network [OSTI]

    A. Fingerle; S. Herminghaus; V. Yu. Zaburdaev

    2007-05-22

    In this work we derive an analytic expression for the Kolmogorov-Sinai entropy of dilute wet granular matter, valid for any spatial dimension. The grains are modelled as hard spheres and the influence of the wetting liquid is described according to the Capillary Model, in which dissipation is due to the hysteretic cohesion force of capillary bridges. The Kolmogorov-Sinai entropy is expanded in a series with respect to density. We find a rapid increase of the leading term when liquid is added. This demonstrates the sensitivity of the granular dynamics to humidity, and shows that the liquid significantly increases the chaoticity of the granular gas.

  16. Impact compaction of a granular material

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Fenton, Gregg; Asay, Blaine; Dalton, Devon

    2015-05-19

    The dynamic behavior of granular materials has importance to a variety of engineering applications. Structural seismic coupling, planetary science, and earth penetration mechanics, are just a few of the application areas. Although the mechanical behavior of granular materials of various types have been studied extensively for several decades, the dynamic behavior of such materials remains poorly understood. High-quality experimental data are needed to improve our general understanding of granular material compaction physics. This study will describe how an instrumented plunger impact system can be used to measure pressure-density relationships for model materials at high and controlled strain rates and subsequentlymore »used for computational modeling.« less

  17. Impact compaction of a granular material

    SciTech Connect (OSTI)

    Fenton, Gregg; Asay, Blaine; Dalton, Devon

    2015-05-19

    The dynamic behavior of granular materials has importance to a variety of engineering applications. Structural seismic coupling, planetary science, and earth penetration mechanics, are just a few of the application areas. Although the mechanical behavior of granular materials of various types have been studied extensively for several decades, the dynamic behavior of such materials remains poorly understood. High-quality experimental data are needed to improve our general understanding of granular material compaction physics. This study will describe how an instrumented plunger impact system can be used to measure pressure-density relationships for model materials at high and controlled strain rates and subsequently used for computational modeling.

  18. Granular Dynamics in Pebble Bed Reactor Cores

    E-Print Network [OSTI]

    Laufer, Michael Robert

    2013-01-01

    Design Criteria for Nucler Power Plants,” U.S. NuclearDesign Criteria GRECO Granular Recirculation Code HDPE High-Density Polyethylene HTR High-Temperature Reactor NRC Nuclear

  19. Mechanisms of dissipation in wet granular matter

    E-Print Network [OSTI]

    A. Fingerle; S. Herminghaus

    2007-08-20

    The impact dynamics between wet surfaces, which dominates the mechanical properties of wet granular matter, is studied both experimentally and theoretically. It is shown that the hysteretic formation and rupture of liquid capillary bridges between adjacent grains accounts reasonably well for most relevant cases of wet granular matter. The various dissipation mechanisms are discussed with particular emphasis on their relevance. Variations of the rupture energy loss with the impact energy are quantified and discussed.

  20. Shear dispersion in dense granular flows

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Christov, Ivan C.; Stone, Howard A.

    2014-04-18

    We formulate and solve a model problem of dispersion of dense granular materials in rapid shear flow down an incline. The effective dispersivity of the depth-averaged concentration of the dispersing powder is shown to vary as the Péclet number squared, as in classical Taylor–Aris dispersion of molecular solutes. An extension to generic shear profiles is presented, and possible applications to industrial and geological granular flows are noted.

  1. Liquid migration in sheared unsaturated granular media

    E-Print Network [OSTI]

    Roman Mani; Dirk Kadau; Hans J. Herrmann

    2012-06-25

    We show how liquid migrates in sheared unsaturated granular media using a grain scale model for capillary bridges. Liquid is redistributed to neighboring contacts after rupture of individual capillary bridges leading to redistribution of liquid on large scales. The liquid profile evolution coincides with a recently developed continuum description for liquid migration in shear bands. The velocity profiles which are linked to the migration of liquid as well as the density profiles of wet and dry granular media are studied.

  2. Contact micromechanics in granular media with clay

    SciTech Connect (OSTI)

    Ita, S.L.

    1994-08-01

    Many granular materials, including sedimentary rocks and soils, contain clay particles in the pores, grain contacts, or matrix. The amount and location of the clays and fluids can influence the mechanical and hydraulic properties of the granular material. This research investigated the mechanical effects of clay at grain-to-grain contacts in the presence of different fluids. Laboratory seismic wave propagation tests were conducted at ultrasonic frequencies using spherical glass beads coated with Montmorillonite clay (SWy-1) onto which different fluids were adsorbed. For all bead samples, seismic velocity increased and attenuation decreased as the contact stiffnesses increased with increasing stress demonstrating that grain contacts control seismic transmission in poorly consolidated and unconsolidated granular material. Coating the beads with clay added stiffness and introduced viscosity to the mechanical contact properties that increased the velocity and attenuation of the propagating seismic wave. Clay-fluid interactions were studied by allowing the clay coating to absorb water, ethyl alcohol, and hexadecane. Increasing water amounts initially increased seismic attenuation due to clay swelling at the contacts. Attenuation decreased for higher water amounts where the clay exceeded the plastic limit and was forced from the contact areas into the surrounding open pore space during sample consolidation. This work investigates how clay located at grain contacts affects the micromechanical, particularly seismic, behavior of granular materials. The need for this work is shown by a review of the effects of clays on seismic wave propagation, laboratory measurements of attenuation in granular media, and proposed mechanisms for attenuation in granular media.

  3. Chromium(VI) Reduction by Hydrogen Sulfide in Aqueous

    E-Print Network [OSTI]

    Deng, Baolin

    , A N D H U I F A N G X U § Department of Environmental Engineering, New Mexico Institute of Mining reductants including zero-valent iron (5, 6), divalent iron (7-15), Fe(II)-bearing minerals (8, 16

  4. Dynamic effective mass of granular media

    E-Print Network [OSTI]

    Chaur-Jian Hsu; David L. Johnson; Rohit A. Ingale; John J. Valenza; Nicolas Gland; Hernan A. Makse

    2008-08-15

    We develop the concept of frequency dependent effective mass, M(omega), of jammed granular materials which occupy a rigid cavity to a filling fraction of 48%, the remaining volume being air of normal room condition or controlled humidity. The dominant features of M(omega) provide signatures of the dissipation of acoustic modes, elasticity and aging effects in the granular medium. We perform humidity controlled experiments and interpret the data in terms of a continuum model and a "trap" model of thermally activated capillary bridges at the contact points. The results suggest that attenuation in the granular materials is influenced significantly by the kinetics of capillary condensation between the asperities at the contacts.

  5. Fourier's Law for a Granular Fluid

    E-Print Network [OSTI]

    James W. Dufty

    2007-07-07

    Newton' viscosity law for the momentum flux and Fourier's law for the heat flux define Navier-Stokes hydrodynamics for a simple, one component fluid. There is ample evidence that a hydrodynamic description applies as well to a mesoscopic granular fluid with the same form for Newton's viscosity law. However, theory predicts a qualitative difference for Fourier's law with an additional contribution from density gradients even at uniform temperature. The reasons for the absence of such terms for normal fluids are indicated, and a related microscopic explanation for their existence in granular fluids is presented.

  6. Melting a granular glass by cooling

    E-Print Network [OSTI]

    Jan Plagge; Claus Heussinger

    2013-02-05

    Driven granular systems readily form glassy phases at high particle volume fractions and low driving amplitudes. We use computer simulations of a driven granular glass to evidence a re-entrance melting transition into a fluid state, which, contrary to intuition, occurs by \\emph{reducing} the amplitude of the driving. This transition is accompanied by anomalous particle dynamics and super-diffusive behavior on intermediate time-scales. We highlight the special role played by frictional interactions, which help particles to escape their glassy cages. Such an effect is in striking contrast to what friction is expected to do: reduce particle mobility by making them stick.

  7. Design and analysis of jammable granular systems

    E-Print Network [OSTI]

    Cheng, Nadia G. (Nadia Gen San)

    2013-01-01

    Jamming--the mechanism by which granular media can transition between liquid-like and solid-like states-has recently been demonstrated as a variable strength and stiffness mechanism in a range of applications. As a low-cost ...

  8. Trajectory entanglement in dense granular materials

    E-Print Network [OSTI]

    James G. Puckett; Frédéric Lechenault; Karen E. Daniels; Jean-Luc Thiffeault

    2012-02-23

    The particle-scale dynamics of granular materials have commonly been characterized by the self-diffusion coefficient $D$. However, this measure discards the collective and topological information known to be an important characteristic of particle trajectories in dense systems. Direct measurement of the entanglement of particle space-time trajectories can be obtained via the topological braid entropy $\\Sbraid$, which has previously been used to quantify mixing efficiency in fluid systems. Here, we investigate the utility of $\\Sbraid$ in characterizing the dynamics of a dense, driven granular material at packing densities near the static jamming point $\\phi_J$. From particle trajectories measured within a two-dimensional granular material, we typically observe that $\\Sbraid$ is well-defined and extensive. However, for systems where $\\phi \\gtrsim 0.79$, we find that $\\Sbraid$ (like $D$) is not well-defined, signifying that these systems are not ergodic on the experimental timescale. Both $\\Sbraid$ and $D$ decrease with either increasing packing density or confining pressure, independent of the applied boundary condition. The related braiding factor provides a means to identify multi-particle phenomena such as collective rearrangements. We discuss possible uses for this measure in characterizing granular systems.

  9. Frequency-dependent fluctuation-dissipation relations in granular gases

    E-Print Network [OSTI]

    Guy Bunin; Yair Shokef; Dov Levine

    2008-05-19

    The Green-Kubo relation for two models of granular gases is discussed. In the Maxwell model in any dimension, the effective temperature obtained from the Green-Kubo relation is shown to be frequency independent, and equal to the average kinetic energy, known as the granular temperature. In the second model analyzed, a mean-field granular gas, the collision rate of a particle is taken to be proportional to its velocity. The Green-Kubo relation in the high frequency limit is calculated for this model, and the effective temperature in this limit is shown to be equal to the granular temperature. This result, taken together with previous results, showing a difference between the effective temperature at zero frequency (the Einstein relation) and the granular temperature, shows that the Green-Kubo relation for granular gases is violated.

  10. Period tripling causes rotating spirals in agitated wet granular layers

    E-Print Network [OSTI]

    Kai Huang; Ingo Rehberg

    2011-07-07

    Pattern formation of a thin layer of vertically agitated wet granular matter is investigated experimentally. Rotating spirals with three arms, which correspond to the kinks between regions with different colliding phases, are the dominating pattern. This preferred number of arms corresponds to period tripling of the agitated granular layer, unlike predominantly subharmonic Faraday crispations in dry granular matter. The chirality of the spatiotemporal pattern corresponds to the rotation direction of the spirals.

  11. Refraction of shear zones in granular materials

    E-Print Network [OSTI]

    Tamas Unger

    2007-01-08

    We study strain localization in slow shear flow focusing on layered granular materials. A heretofore unknown effect is presented here. We show that shear zones are refracted at material interfaces in analogy with refraction of light beams in optics. This phenomenon can be obtained as a consequence of a recent variational model of shear zones. The predictions of the model are tested and confirmed by 3D discrete element simulations. We found that shear zones follow Snell's law of light refraction.

  12. Dynamic effective mass of granular media

    E-Print Network [OSTI]

    John Valenza; Chaur-Jian Hsu; Rohit Ingale; Nicolas Gland; Hernán A. Makse; David Linton Johnson

    2009-05-08

    We report an experimental and theoretical investigation of the frequency-dependent effective mass, $\\tilde{M}(\\omega)$, of loose granular particles which occupy a rigid cavity to a given filling fraction, the remaining volume being air of differing humidities. This allow us to study the mechanisms of elastic response and attenuation of acoustic modes in granular media. We demonstrate that this is a sensitive and direct way to measure those properties of the granular medium that are the cause of the changes in acoustic properties of structures containing grain-filled cavities. Specifically, we apply this understanding to the case of the flexural resonances of a rectangular bar with a grain-filled cavity within it. The dominant features of $\\tilde{M}(\\omega)$ are a sharp resonance and a broad background, which we analyze within the context of simple models. We find that: a) These systems may be understood in terms of a height-dependent and diameter-dependent effective sound speed ($\\sim 100-300$ m/s) and an effective viscosity ($\\sim 5\\times 10^4$ Poise). b) There is a dynamic Janssen effect in the sense that, at any frequency, and depending on the method of sample preparation, approximately one-half of the effective mass is borne by the side walls of the cavity and one-half by the bottom. c) By performing experiments under varying humidity conditions we conclude that, on a fundamental level, damping of acoustic modes is dominated by adsorbed films of water at grain-grain contacts in our experiments, not by global viscous dampening. d) There is a monotonically increasing effect of humidity on the dampening of the fundamental resonance within the granular medium which translates to a non-monotonic, but predictable, variation of dampening within the grain-loaded bar.

  13. Executive Summary The remediation of radionuclides and heavy metals using current technology is generally

    E-Print Network [OSTI]

    and effectively in the management of radioactive waste almost from the start of the nuclear age; zeolites, now is generally a costly and challenging proposition. Though funds for new technology development are limited and waste reduction. For example, zero-valent iron (ZVI) nanoparticles for the remediation of chlorinated

  14. Environmental Aspects of Two Volatile Organic Compound Groundwater Treatment Designs at the Rocky Flats Site - 13135

    SciTech Connect (OSTI)

    Michalski, Casey C.; DiSalvo, Rick; Boylan, John

    2013-07-01

    DOE's Rocky Flats Site in Colorado is a former nuclear weapons production facility that began operations in the early 1950's. Because of releases of hazardous substances to the environment, the federally owned property and adjacent offsite areas were placed on the CERCLA National Priorities List in 1989. The final remedy was selected in 2006. Engineered components of the remedy include four groundwater treatment systems that were installed before closure as CERCLA-accelerated actions. Two of the systems, the Mound Site Plume Treatment System and the East Trenches Plume Treatment System, remove low levels of volatile organic compounds using zero-valent iron media, thereby reducing the loading of volatile organic compounds in surface water resulting from the groundwater pathway. However, the zero-valent iron treatment does not reliably reduce all volatile organic compounds to consistently meet water quality goals. While adding additional zero-valent iron media capacity could improve volatile organic compound removal capability, installation of a solar powered air-stripper has proven an effective treatment optimization in further reducing volatile organic compound concentrations. A comparison of the air stripper to the alternative of adding additional zero-valent iron capacity to improve Mound Site Plume Treatment System and East Trenches Plume Treatment System treatment based on several key sustainable remediation aspects indicates the air stripper is also more 'environmentally friendly'. These key aspects include air pollutant emissions, water quality, waste management, transportation, and costs. (authors)

  15. Dispersion enhanced metal/zeolite catalysts

    DOE Patents [OSTI]

    Sachtler, W.M.H.; Tzou, M.S.; Jiang, H.J.

    1987-03-31

    Dispersion stabilized zeolite supported metal catalysts are provided as bimetallic catalyst combinations. The catalyst metal is in a reduced zero valent form while the dispersion stabilizer metal is in an unreduced ionic form. Representative catalysts are prepared from platinum or nickel as the catalyst metal and iron or chromium dispersion stabilizer.

  16. Unified force law for granular impact cratering

    E-Print Network [OSTI]

    H. Katsuragi; D. J. Durian

    2007-03-02

    Experiments on the low-speed impact of solid objects into granular media have been used both to mimic geophysical events and to probe the unusual nature of the granular state of matter. Observations have been interpreted in terms of conflicting stopping forces: product of powers of projectile depth and speed; linear in speed; constant, proportional to the initial impact speed; and proportional to depth. This is reminiscent of high-speed ballistics impact in the 19th and 20th centuries, when a plethora of empirical rules were proposed. To make progress, we developed a means to measure projectile dynamics with 100 nm and 20 us precision. For a 1-inch diameter steel sphere dropped from a wide range of heights into non-cohesive glass beads, we reproduce prior observations either as reasonable approximations or as limiting behaviours. Furthermore, we demonstrate that the interaction between projectile and medium can be decomposed into the sum of velocity-dependent inertial drag plus depth-dependent friction. Thus we achieve a unified description of low-speed impact phenomena and show that the complex response of granular materials to impact, while fundamentally different from that of liquids and solids, can be simply understood.

  17. Dynamic Behaviors of Supersonic Granular Media under Vertical Vibration

    E-Print Network [OSTI]

    Kai Huang; Peng Zhang; Guoqing Miao; Rongjue Wei

    2005-11-29

    We present experimental study of vibrofluidized granular materials by high speed photography. Statistical results present the averaged dynamic behaviors of granular materials in one cycle, including the variations of height, velocity and mechanical energy of the center of mass. Furthermore, time-space distribution of granular temperature which corresponds to the random kinetic energy shows that a temperature peak forms in the compression period and propagates upward with a steepened front. The Mach number in the steepened front is found to be greater than unity, indicating a shock propagating in the supersonic granular media.

  18. Studies of the regeneration of activated bauxite used as granular...

    Office of Scientific and Technical Information (OSTI)

    GRANULAR BED FILTERS; HOT GAS CLEANUP; POTASSIUM CHLORIDES; SORPTION; SODIUM CHLORIDES; AIR POLLUTION CONTROL; COAL; FLUIDIZED-BED COMBUSTORS; ALKALI METAL COMPOUNDS; ALUMINIUM...

  19. Studies of the regeneration of activated bauxite used as granular...

    Office of Scientific and Technical Information (OSTI)

    bauxite used as granular sorbent for the control of alkali vapors from hot flue gas of coal combustion Citation Details In-Document Search Title: Studies of the...

  20. Nonlinear elasto-plastic model for dense granular flow

    E-Print Network [OSTI]

    Ken Kamrin

    2009-05-07

    This work proposes a model for granular deformation that predicts the stress and velocity profiles in well-developed dense granular flows. Recent models for granular elasticity (Jiang and Liu 2003) and rate-sensitive plastic flow (Jop et al. 2006) are reformulated and combined into one universal granular continuum law, capable of predicting flowing regions and stagnant zones simultaneously in any arbitrary 3D flow geometry. The unification is performed by justifying and implementing a Kroner-Lee elasto-plastic decomposition, with care taken to ensure certain continuum physical principles are necessarily upheld. The model is then numerically implemented in multiple geometries and results are compared to experiments and discrete simulations.

  1. Concurrent multiscale computational modeling for dense dry granular materials interfacing

    E-Print Network [OSTI]

    Regueiro, Richard A.

    of interfacial mechanics between granular soil and tire, tool, or penetrometer, while properly representing far computational modeling of interfacial mechanics between granular materials and deformable solid bodies, agricultural grains (in silo flows), dry soils (sand, silt, gravel), and lunar and martian regolith (soil found

  2. Simulation of Gravity Flow of Granular Materials in Silos

    E-Print Network [OSTI]

    and handle vast quantities of raw materials in granular form. The material is usually retrieved throughSimulation of Gravity Flow of Granular Materials in Silos Pierre A. Gremaud1 and John V. Matthews1 materials in silos under the action of gravity is considered. In the case of a Mohr-Coulomb material

  3. Geological and mathematical framework for failure modes in granular rock

    E-Print Network [OSTI]

    Borja, Ronaldo I.

    Geological and mathematical framework for failure modes in granular rock Atilla Aydina, *, Ronaldo I. Borjab , Peter Eichhubla,1 a Department of Geological and Environmental Sciences, Stanford processes in granular rock and provide a geological framework for the corresponding structures. We describe

  4. Using NMR to Validate First-Principles Granular Flow Equations

    E-Print Network [OSTI]

    D. Candela; C. Huan; K. Facto; R. Wang; R. W. Mair; R. L. Walsworth

    2005-10-23

    Nuclear magnetic resonance (NMR) experiments are described for two granular-flow systems, the vibrofluidized bed and the gas-fluidized bed. Using pulsed field gradient, magnetic resonance imaging, and hyperpolarized gas NMR, detailed information is obtained for the density and motions of both grains and interstitial gas. For the vibrofluidized bed, the granular temperature profile is measured and compared with a first-principles formulation of granular hydrodynamics. For the gas-fluidized bed, dynamic correlations in the grain density are used to measure the bubble velocity and hyperpolarized xenon gas NMR is used to measure the bubble-emulsion exchange rate. A goal of these measurements is to verify in earth gravity first-principles theories of granular flows, which then can be used to make concrete predictions for granular flows in reduced gravity.

  5. An Expression for the Granular Elastic Energy

    E-Print Network [OSTI]

    Yimin Jiang; Hepeng Zheng; Zheng Peng; Liping Fu; Shixiong Song; Qicheng Sun; Michael Mayer; Mario Liu

    2012-06-13

    Granular Solid Hydrodynamics (GSH) is a broad-ranged continual mechanical description of granular media capable of accounting for static stress distributions, yield phenomena, propagation and damping of elastic waves, the critical state, shear band, and fast dense flow. An important input of GSH is an expression for the elastic energy needed to deform the grains. The original expression, though useful and simple, has some draw-backs. Therefore, a slightly more complicated expression is proposed here that eliminates three of them: (1) The maximal angle at which an inclined layer of grains remains stable is increased from $26^\\circ$ to the more realistic value of $30^\\circ$. (2)Depending on direction and polarization, transverse elastic waves are known to propagate at slightly different velocities. The old expression neglects these differences, the new one successfully reproduces them. (3) Most importantly, the old expression contains only the Drucker-Prager yield surface. The new one contains in addition those named after Coulomb, Lade-Duncan and Matsuoka-Nakai -- realizing each, and interpolating between them, by shifting a single scalar parameter.

  6. Pressure-shear experiments on granular materials.

    SciTech Connect (OSTI)

    Reinhart, William Dodd; Thornhill, Tom Finley, III; Vogler, Tracy John; Alexander, C. Scott

    2011-10-01

    Pressure-shear experiments were performed on granular tungsten carbide and sand using a newly-refurbished slotted barrel gun. The sample is a thin layer of the granular material sandwiched between driver and anvil plates that remain elastic. Because of the obliquity, impact generates both a longitudinal wave, which compresses the sample, and a shear wave that probes the strength of the sample. Laser velocity interferometry is employed to measure the velocity history of the free surface of the anvil. Since the driver and anvil remain elastic, analysis of the results is, in principal, straightforward. Experiments were performed at pressures up to nearly 2 GPa using titanium plates and at higher pressure using zirconium plates. Those done with the titanium plates produced values of shear stress of 0.1-0.2 GPa, with the value increasing with pressure. On the other hand, those experiments conducted with zirconia anvils display results that may be related to slipping at an interface and shear stresses mostly at 0.1 GPa or less. Recovered samples display much greater particle fracture than is observed in planar loading, suggesting that shearing is a very effective mechanism for comminution of the grains.

  7. Granular impact and the critical packing state

    E-Print Network [OSTI]

    Umbanhowar, Paul; 10.1103/PhysRevE.82.010301

    2010-01-01

    Impact dynamics during collisions of spheres with granular media reveal a pronounced and non-trivial dependence on volume fraction \\phi. Post impact crater morphology identifies the critical packing state \\phi_{cps}, where sheared grains neither dilate nor consolidate, and indicates an associated change in spatial response. Current phenomenological models fail to capture the observed impact force for most \\phi; only near \\phi_{cps} is force separable into additive terms linear in depth and quadratic in velocity. At fixed depth the quadratic drag coefficient decreases (increases) with depth for \\phi \\phi_{cps}). At fixed low velocity, depth dependence of force shows a Janssen-type exponential response with a length scale that decreases with increasing \\phi; and is nearly constant for \\phi > \\phi_{cps}.

  8. Granular impact and the critical packing state

    E-Print Network [OSTI]

    Paul Umbanhowar; Daniel I. Goldman

    2010-07-16

    Impact dynamics during collisions of spheres with granular media reveal a pronounced and non-trivial dependence on volume fraction \\phi. Post impact crater morphology identifies the critical packing state \\phi_{cps}, where sheared grains neither dilate nor consolidate, and indicates an associated change in spatial response. Current phenomenological models fail to capture the observed impact force for most \\phi; only near \\phi_{cps} is force separable into additive terms linear in depth and quadratic in velocity. At fixed depth the quadratic drag coefficient decreases (increases) with depth for \\phi \\phi_{cps}). At fixed low velocity, depth dependence of force shows a Janssen-type exponential response with a length scale that decreases with increasing \\phi; and is nearly constant for \\phi > \\phi_{cps}.

  9. Frictional granular mechanics: A variational approach

    SciTech Connect (OSTI)

    Holtzman, R.; Silin, D.B.; Patzek, T.W.

    2009-10-16

    The mechanical properties of a cohesionless granular material are evaluated from grain-scale simulations. Intergranular interactions, including friction and sliding, are modeled by a set of contact rules based on the theories of Hertz, Mindlin, and Deresiewicz. A computer generated, three-dimensional, irregular pack of spherical grains is loaded by incremental displacement of its boundaries. Deformation is described by a sequence of static equilibrium configurations of the pack. A variational approach is employed to find the equilibrium configurations by minimizing the total work against the intergranular loads. Effective elastic moduli are evaluated from the intergranular forces and the deformation of the pack. Good agreement between the computed and measured moduli, achieved with no adjustment of material parameters, establishes the physical soundness of the proposed model.

  10. Universal robotic gripper based on the jamming of granular material

    E-Print Network [OSTI]

    Jaeger, Heinrich M.

    it and conforms to its shape. Upon application of a vacuum the granular material contracts and hardens quickly individual fingers by a material or interface that upon contact molds itself around the object. Such a

  11. Good Sources of Nutrients: Iron 

    E-Print Network [OSTI]

    Scott, Amanda; Replogle, Jacqueline

    2008-08-28

    Iron is a mineral that functions primarily to carry oxygen in the body. This publication explains how people can get enough iron in their diets and how to prepare foods to retain iron. It also lists foods that are good sources of iron. (2 pp., 2...

  12. Standleg Moving Granular Bed Filter development program

    SciTech Connect (OSTI)

    Newby, R.A.; Yang, W.C.; Smeltzer, E.E.

    1992-11-01

    The design, fabrication, and installation of the cold flow test facility has been completed. The SMGBF test facility shown in Figure 2 consists of a solids feed hopper, a transparent test vessel, a screw conveyor, a 55-gal drum for solids storage, a dust feeder, a baghouse filter, and the associated instrumentation for flow and pressure control and measurement. The standleg is 11-in ID by 3-ft long, and also transparent to facilitate observation. The crushed acrylic particles of characteristics shown in Table 1 are used as the bed media. The bed particles were selected, by maintaining the particle size while reducing the particle density, to simulate the minimum fluidization velocity expected under high-temperature, high-pressure conditions. By maintaining the particle size, the bed effectively simulates the bed packing and voidage in the moving bed which is directly related to the efficiency of particulate removal and pressure drop characteristics. The test facility performed as designed and no particular difficulties were encountered. The baseline data on pressure profiles across the stationary and the moving granular beds were obtained for gas face velocities up to 6 ft/s, higher than the minimum fluidization velocity of the bed material (5 ft/s), and no visible fluidization was observed at the base of the standleg. This confirms the operational feasibility of the compact SMGBF design.

  13. Standleg Moving Granular Bed Filter development program

    SciTech Connect (OSTI)

    Newby, R.A.; Yang, W.C.; Smeltzer, E.E.

    1992-01-01

    The design, fabrication, and installation of the cold flow test facility has been completed. The SMGBF test facility shown in Figure 2 consists of a solids feed hopper, a transparent test vessel, a screw conveyor, a 55-gal drum for solids storage, a dust feeder, a baghouse filter, and the associated instrumentation for flow and pressure control and measurement. The standleg is 11-in ID by 3-ft long, and also transparent to facilitate observation. The crushed acrylic particles of characteristics shown in Table 1 are used as the bed media. The bed particles were selected, by maintaining the particle size while reducing the particle density, to simulate the minimum fluidization velocity expected under high-temperature, high-pressure conditions. By maintaining the particle size, the bed effectively simulates the bed packing and voidage in the moving bed which is directly related to the efficiency of particulate removal and pressure drop characteristics. The test facility performed as designed and no particular difficulties were encountered. The baseline data on pressure profiles across the stationary and the moving granular beds were obtained for gas face velocities up to 6 ft/s, higher than the minimum fluidization velocity of the bed material (5 ft/s), and no visible fluidization was observed at the base of the standleg. This confirms the operational feasibility of the compact SMGBF design.

  14. Quasi-static mechanics of granular materials

    E-Print Network [OSTI]

    P. Evesque

    2005-07-13

    This textbook in French describes the rheology of granular materials in the quasi static regime at a macroscopic scale. It starts defining cohesion, friction and the Coulomb approach, from the large-strain range. Then it focuses on the range of small and intermediate deformation when the medium can dilate if it is dense; different specific typical tests (oedometric, constant pressure, constant volume) are defined, the behaviours they lead are carefully described and their dependences upon initial density recalled. Roles of friction and dilatancy are exemplified and their link with the deviatoric stress too. "Natural" "phase space" is defined, which is (specific volume, mean pressure, axial or deviatoric stress). Then the "critical" state, the "characteristic" state and the Rowe's law of dilatancy are defined, and the previous behaviours analysed in term of plastic deformation, showing that these behaviours obey a specific rule of dissipation. An isotropic incremental modelling is then proposed and studied, with a pseudo Poisson coefficient that evolves with the stress ratio. It shows a good agreement with experimental trends, while the theory keeps simple, which describes in particular the isochoric compression and the oedometric compression correctly. Cyclic behaviours are then described, and their link with soil liquefaction, with a peculiar attention to the role of stress ratio. Basic concepts on micro-macro passage are given, starting with a theoretical approach leading to an exponential distribution of forces ; then it proposes a theory for the compaction of the medium with pressure, that predicts the v-log(p) law for the critical state.

  15. A predictive, size-dependent continuum model for dense granular flows

    E-Print Network [OSTI]

    Henann, David Lee

    Dense granular materials display a complicated set of flow properties, which differentiate them from ordinary fluids. Despite their ubiquity, no model has been developed that captures or predicts the complexities of granular ...

  16. Phases of granular segregation in a binary mixture P. M. Reis,1,

    E-Print Network [OSTI]

    Reis, Pedro Miguel

    and show that segregation can be suppressed as the total filling fraction of the granular layer, C and empirical knowledge. More recently the physics community has taken an increased interest in granular mate

  17. Erosion of a granular bed driven by laminar fluid flow

    E-Print Network [OSTI]

    A. E. Lobkovsky; A. V. Orpe; R. Molloy; A. Kudrolli; D. H. Rothman

    2008-05-01

    Motivated by examples of erosive incision of channels in sand, we investigate the motion of individual grains in a granular bed driven by a laminar fluid to give us new insights into the relationship between hydrodynamic stress and surface granular flow. A closed cell of rectangular cross-section is partially filled with glass beads and a constant fluid flux $Q$ flows through the cell. The refractive indices of the fluid and the glass beads are matched and the cell is illuminated with a laser sheet, allowing us to image individual beads. The bed erodes to a rest height $h_r$ which depends on $Q$. The Shields threshold criterion assumes that the non-dimensional ratio $\\theta$ of the viscous stress on the bed to the hydrostatic pressure difference across a grain is sufficient to predict the granular flux. Furthermore, the Shields criterion states that the granular flux is non-zero only for $\\theta >\\theta_c$. We find that the Shields criterion describes the observed relationship $h_r \\propto Q^{1/2}$ when the bed height is offset by approximately half a grain diameter. Introducing this offset in the estimation of $\\theta$ yields a collapse of the measured Einstein number $q^*$ to a power-law function of $\\theta - \\theta_c$ with exponent $1.75 \\pm 0.25$. The dynamics of the bed height relaxation are well described by the power law relationship between the granular flux and the bed stress.

  18. Plug flow and the breakdown of Bagnold scaling in cohesive granular flows Robert Brewster,1

    E-Print Network [OSTI]

    Levine, Alex J.

    Plug flow and the breakdown of Bagnold scaling in cohesive granular flows Robert Brewster,1 Gary S Cohesive granular media flowing down an inclined plane are studied by discrete element simulations. Previous work on cohesionless granular media demonstrated that within the steady flow regime where gravi

  19. Advances in the simulation and automated measurement of well-sorted granular material

    E-Print Network [OSTI]

    ] In a plan view image of a granular material, as the geometric projection of a 3D surface onto a 2D plane on the structure of well-sorted natural granular material (sediment), new methods are described for automated granular material. The principal objective here is to provide simple optical techniques for the non

  20. A two-layer granular landslide model for tsunami wave generation: Theory and computation

    E-Print Network [OSTI]

    Kirby, James T.

    A two-layer granular landslide model for tsunami wave generation: Theory and computation Gangfeng for granular landslide motion and tsunami wave generation. The landslide, either submarine or subaerial experiments on impulsive wave generation by subaerial granular landslides. Model results illustrate a complex

  1. Runaway electrification of friable self-replicating granular matter

    E-Print Network [OSTI]

    Julyan H. E. Cartwright; Bruno Escribano; Hinrich Grothe; Oreste Piro; C. Ignacio Sainz Díaz; Idan Tuval

    2014-11-19

    We establish that the nonlinear dynamics of collisions between particles favors the charging of a insulating, friable, self-replicating granular material that undergoes nucleation, growth, and fission processes; we demonstrate with a minimal dynamical model that secondary nucleation produces a positive feedback in an electrification mechanism that leads to runaway charging. We discuss ice as an example of such a self-replicating granular material: We confirm with laboratory experiments in which we grow ice from the vapor phase in situ within an environmental scanning electron microscope that charging causes fast-growing and easily breakable palm-like structures to form, which when broken off may form secondary nuclei. We propose that thunderstorms, both terrestrial and on other planets, and lightning in the solar nebula are instances of such runaway charging arising from this nonlinear dynamics in self-replicating granular matter.

  2. New patterns in high-speed granular flows

    E-Print Network [OSTI]

    Nicolas Brodu; Renaud Delannay; Alexandre Valance; Patrick Richard

    2015-03-04

    We report on new patterns in high-speed flows of granular materials obtained by means of extensive numerical simulations. These patterns emerge from the destabilization of unidirectional flows upon increase of mass holdup and inclination angle, and are characterized by complex internal structures including secondary flows, heterogeneous particle volume fraction, symmetry breaking and dynamically maintained order. In particular, we evidenced steady and fully developed "supported" flows, which consist of a dense core surrounded by a highly energetic granular gas. Interestingly, despite their overall diversity, these regimes are shown to obey a scaling law for the mass flow rate as a function of the mass holdup. This unique set of 3D flow regimes raises new challenges for extending the scope of current granular rheological models.

  3. Iron oxyhydroxide mineralization on microbial extracellular polysaccha...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Iron oxyhydroxide mineralization on microbial extracellular polysaccharides Citation Details In-Document Search Title: Iron oxyhydroxide mineralization on...

  4. Power-law friction in closely-packed granular materials

    E-Print Network [OSTI]

    Takahiro Hatano

    2007-05-08

    In order to understand the nature of friction in closely-packed granular materials, a discrete element simulation on granular layers subjected to isobaric plain shear is performed. It is found that the friction coefficient increases as the power of the shear rate, the exponent of which does not depend on the material constants. Using a nondimensional parameter that is known as the inertial number, the power-law can be cast in a generalized form so that the friction coefficients at different confining pressures collapse on the same curve. We show that the volume fraction also obeys a power-law.

  5. Energy Loss at Propagating Jamming Fronts in Granular Gas Clusters

    E-Print Network [OSTI]

    Justin C. Burton; Peter Y. Lu; Sidney R. Nagel

    2013-10-15

    We explore the initial moments of impact between two dense granular clusters in a two-dimensional geometry. The particles are composed of solid CO$_{2}$ and are levitated on a hot surface. Upon collision, the propagation of a dynamic "jamming front" produces a distinct regime for energy dissipation in a granular gas in which the translational kinetic energy decreases by over 90%. Experiments and associated simulations show that the initial loss of kinetic energy obeys a power law in time, $\\Delta E=-Kt^{3/2}$, a form that can be predicted from kinetic arguments.

  6. Craters Formed in Granular Beds by Impinging Jets of Gas

    E-Print Network [OSTI]

    Philip T. Metzger; Robert C. Latta III; Jason M. Schuler; Christopher D. Immer

    2009-05-29

    When a jet of gas impinges vertically on a granular bed and forms a crater, the grains may be moved by several different mechanisms: viscous erosion, diffused gas eruption, bearing capacity failure, and/or diffusion-driven shearing. The relative importance of these mechanisms depends upon the flow regime of the gas, the mechanical state of the granular material, and other physical parameters. Here we report research in two specific regimes: viscous erosion forming scour holes as a function of particle size and gravity; and bearing capacity failure forming deep transient craters as a function of soil compaction.

  7. Numerical analysis of impact processes of granular jets

    E-Print Network [OSTI]

    Tomohiko G. Sano; Hisao Hayakawa

    2013-03-20

    The rheology of a three-dimensional granular jet during an impact is investigated numerically. The cone-like scattering pattern and the sheet-like pattern observed in an experiment [X. Cheng, et al. Phys. Rev. Lett. 99, 188001 (2007)] can be reproduced through our calculation. We discuss the constitutive equation for granular jet impact in terms of our simulation. From the analysis of an effective friction constant, which is the ratio between the shear stress and the pressure the assumption of the zero yield stress would be natural in our setup and the shear visocity is not small in contrast to the suggestion by the experiment.

  8. Experimental Investigation of Plastic Deformations Before Granular Avalanche

    E-Print Network [OSTI]

    Axelle Amon; Roman Bertoni; Jérôme Crassous

    2012-11-23

    We present an experimental study of the deformation inside a granular material that is progressively tilted. We investigate the deformation before the avalanche with a spatially resolved Diffusive Wave Spectroscopy setup. At the beginning of the inclination process, we first observe localized and isolated events in the bulk, with a density which decreases with the depth. As the angle of inclination increases, series of micro-failures occur periodically in the bulk, and finally a granular avalanche takes place. The micro-failures are observed only when the tilt angles are larger than a threshold angle much smaller than the granular avalanche angle. We have characterized the density of reorganizations and the localization of micro-failures. We have also explored the effect of the nature of the grains, the relative humidity conditions and the packing fraction of the sample. We discuss those observations in the framework of the plasticity of granular matter. Micro-failures may then be viewed as the result of the accumulation of numerous plastic events.

  9. Numerical issues in plasticity models for granular flows

    E-Print Network [OSTI]

    has a long history, largely due to its connection to soil mechan- ics in civil and military 27695-8205, USA Abstract Friction plays a fundamental role in the Mechanics of granular materials. Two material mechanics also plays a fun- damental role in countless geophysical phenomena. While most

  10. Granular impact and the critical packing state Paul Umbanhowar

    E-Print Network [OSTI]

    Goldman, Daniel I.

    during collisions of spheres with granular media reveal a pronounced and nontrivial dependence on volume phenomenological models fail to capture the observed impact force for most ; only near cps is force separable into additive terms linear in depth and quadratic in velocity. At fixed depth the quadratic drag coefficient

  11. SECONDARY CIRCULATION IN GRANULAR FLOW THROUGH NONAXISYMMETRIC HOPPERS

    E-Print Network [OSTI]

    25 1. Introduction. In manufacturing industries, raw materials are stored in gran- ular form. MATTHEWS, AND DAVID G. SCHAEFFER Abstract. Jenike's radial solution, widely used in the design of materials of granular material through an infinite, right-circular cone. In this paper we study how the geometry

  12. SECONDARY CIRCULATION IN GRANULAR FLOW THROUGH NONAXISYMMETRIC HOPPERS

    E-Print Network [OSTI]

    25 1. Introduction. In manufacturing industries, raw materials are stored in gran­ ular form of materials­handling equipment, is a similarity solution of steady­state continuum equations for the flow under gravity of granular material through an infinite, right­circular cone. In this paper we study how

  13. Gas Bubbles Emerging from a Submerged Granular Bed

    E-Print Network [OSTI]

    Meier, John A; Brennen, Christopher E

    2009-01-01

    This fluid dynamics video was submitted to the Gallery of Fluid Motion for the 2009 APS Division of Fluid Dynamics Meeting in Minneapolis, Minnesota. In this video we show some results from a simple experiment where air was injected by a single nozzle at known constant flow rates in the bottom of a granular bed submerged in water. The injected air propagates through the granular bed in one of two modes. Mode 1 emergence involves small discrete bubbles taking tortuous paths through the interstitial space of the bed. Multiple small bubbles can be emitted from the bed in an array of locations at the same time during Mode 1 emergence. Mode 2 emergence involves large discrete bubbles locally fluidizing the granular bed and exiting the bed approximately above the injection site. Bead diameter, bead density, and air flow rate were varied to investigate the change in bubble release behavior at the top of the granular bed. This system is a useful model for methane seeps in lakes. Methane bubbles are released from the ...

  14. Comparison of Mesomechanical and Continuum Granular Flow Models for Ceramics

    SciTech Connect (OSTI)

    Curran, D. R.

    2006-07-28

    Constitutive models for the shear strength of ceramics undergoing fracture are needed for modeling long rod and shaped-charge jet penetration events in ceramic armor. The ceramic material ahead of the penetrator has been observed to be finely comminuted material that flows around the nose of the eroding penetrator (Shockey et al.). The most-used continuum models are of the Drucker-Prager type with an upper cutoff, or of the Mohr-Coulomb type with strain rate dependence and strain softening. A disadvantage of such models is that they have an unclear connection to the actual microscopic processes of granular flow and comminution. An alternate approach is to use mesomechanical models that describe the dynamics of the granular flow, as well as containing a description of the granular comminution and resultant material softening. However, a disadvantage of the mesomechanical models is that they are computationally more burdensome to apply. In the present paper, we compare the behaviors of a mesomechanical model, FRAGBED2, with the Walker and Johnson-Holmquist continuum models, where the granular material is subjected to simple strain histories under various confining pressures and strain rates. We conclude that the mesomechanical model can provide valuable input to the continuum models, both in interpretation of the continuum models' parameters and in suggesting their range of applicability.

  15. Flows of Dense Granular Yoel Forterre and Olivier Pouliquen

    E-Print Network [OSTI]

    Forterre, Yoël

    explore the different flow regimes and discuss the granular solid-liquid and liquid-gas transition are aware that a collection of solid grains can behave macroscopically like a liquid and flow. However in geophysics for the description and prediction of natural hazards such as landslides, rock avalanches

  16. Nonlinear dynamics, granular media and dynamic earthquake triggering

    E-Print Network [OSTI]

    Paris 7 - Denis Diderot, Université

    triggering appears more commonly in geothermal areas3 . Proposed mecha- nisms include increased pore pressure load corresponding to effective pressure P (effective pressure ¼ confining pressure minus pore pressure, and the pore pressure is 1 atm (0.101 MPa)) ranging from 0.07 to 0.3 MPa is applied to the granular sample

  17. High-Frequency Resistivity of Soft Magnetic Granular Films

    E-Print Network [OSTI]

    High-Frequency Resistivity of Soft Magnetic Granular Films Weidong Li Yuqin Sun C. R. Sullivan From TRANSACTIONS ON MAGNETICS, VOL. 41, NO. 10, OCTOBER 2005 3283 High-Frequency Resistivity of Soft Magnetic resistivity. In order to confirm their electrical characteristics at high frequency, the frequency and current

  18. Oblique shocks in rapid granular flows Kristin Martha Hkonardttir

    E-Print Network [OSTI]

    Hogg, Andrew

    -surface granular flows and deflecting dams is investigated by laboratory experimentation and by the formulation with the impermeable barrier. Deflecting dams are deployed to defend against large-scale snow avalanches almost discontinuous transi- tions between flow states bores and hydraulic jumps

  19. Microbial reduction of iron ore

    DOE Patents [OSTI]

    Hoffmann, Michael R. (Pasadena, CA); Arnold, Robert G. (Pasadena, CA); Stephanopoulos, Gregory (Pasadena, CA)

    1989-01-01

    A process is provided for reducing iron ore by treatment with microorganisms which comprises forming an aqueous mixture of iron ore, microorganisms operable for reducing the ferric iron of the iron ore to ferrous iron, and a substrate operable as an energy source for the microbial reduction; and maintaining the aqueous mixture for a period of time and under conditions operable to effect the reduction of the ore. Preferably the microorganism is Pseudomonas sp. 200 and the reduction conducted anaerobically with a domestic wastewater as the substrate. An aqueous solution containing soluble ferrous iron can be separated from the reacted mixture, treated with a base to precipitate ferrous hydroxide which can then be recovered as a concentrated slurry.

  20. Microbial reduction of iron ore

    DOE Patents [OSTI]

    Hoffmann, M.R.; Arnold, R.G.; Stephanopoulos, G.

    1989-11-14

    A process is provided for reducing iron ore by treatment with microorganisms which comprises forming an aqueous mixture of iron ore, microorganisms operable for reducing the ferric iron of the iron ore to ferrous iron, and a substrate operable as an energy source for the microbial reduction; and maintaining the aqueous mixture for a period of time and under conditions operable to effect the reduction of the ore. Preferably the microorganism is Pseudomonas sp. 200 and the reduction conducted anaerobically with a domestic wastewater as the substrate. An aqueous solution containing soluble ferrous iron can be separated from the reacted mixture, treated with a base to precipitate ferrous hydroxide which can then be recovered as a concentrated slurry. 11 figs.

  1. MECS 2006- Iron and Steel

    Broader source: Energy.gov [DOE]

    Manufacturing Energy and Carbon Footprint for Iron and Steel Sector (NAICS 3311, 3312) with Total Energy Input, October 2012 (MECS 2006)

  2. Clustering instability in a freely falling granular jet

    E-Print Network [OSTI]

    Matthias E. Möbius

    2006-04-03

    This paper investigates a clustering instability of a freely falling granular jet composed of 100 micron glass spheres. The granular flow out of a circular nozzle starts out spatially uniform and then, further downstream, breaks up into well defined clusters. The role of air is investigated in this phenomenon by changing the ambient air pressure down to 1/5000th atm. An optical method is used that measures inhomogeneities in the flow in order to quantify the growth of the clusters. Clustering is observed down to the lowest pressure and the presence of air leads to larger drops but does not initiate the drop formation. The analysis shows that the drop size is set by fluctuations on the order of the size of the particles at the nozzle.

  3. On the capillary stress tensor in wet granular materials

    E-Print Network [OSTI]

    Luc Scholtès; Pierre-Yves Hicher; François Nicot; Bruno Chareyre; Félix Darve

    2011-05-05

    This paper presents a micromechanical study of unsaturated granular media in the pendular regime, based upon numerical experiments using the discrete element method, compared to a microstructural elastoplastic model. Water effects are taken into account by adding capillary menisci at contacts and their consequences in terms of force and water volume are studied. Simulations of triaxial compression tests are used to investigate both macro and micro-effects of a partial saturation. The results provided by the two methods appear to be in good agreement, reproducing the major trends of a partially saturated granular assembly, such as the increase in the shear strength and the hardening with suction. Moreover, a capillary stress tensor is exhibited from capillary forces by using homogenisation techniques. Both macroscopic and microscopic considerations emphasize an induced anisotropy of the capillary stress tensor in relation with the pore fluid distribution inside the material. In so far as the tensorial nature of this fluid fabric implies shear effects on the solid phase associated with suction, a comparison has been made with the standard equivalent pore pressure assumption. It is shown that water effects induce microstrural phenomena that cannot be considered at the macro level, particularly when dealing with material history. Thus, the study points out that unsaturated soil stress definitions should include, besides the macroscopic stresses such as the total stress, the microscopic interparticle stresses such as the ones resulting from capillary forces, in order to interpret more precisely the implications of the pore fluid on the mechanical behaviour of granular materials.

  4. Moving granular-bed filter development program topical report

    SciTech Connect (OSTI)

    Newby, R.A.; Dilmore, W.J.; Fellers, A.W.; Gasparovic, A.C.; Kittle, W.F.; Lippert, T.E.; Smeltzer, E.E.; Yang, W.C.

    1991-10-17

    The Westinghouse Science Technology Center has proposed a novel moving granular-bed filter concept, the Standleg Moving Granular-Bed Filter (S-MGBF) system, that overcomes the inherent deficiencies of the current state-of-the-art moving granular-bed filter technology. The S-MGBF system combines two unique features that make it highly effective for use in advanced coal-fueled power plants. First, the S-MGBF system applies pelletization technology to generate filter pellets from the power plant solid waste materials, and uses these pellets as a once-through'' filtering media to eliminate the need for costly, complex, and large filter media recycling equipment. This pelletizing step also generates a more environmentally acceptable solid waste product and provides the potential to incorporate gas-phase contaminant sorbents into the filtering media. Secondly, the S-MGBF system passes these pellets and the flyash laden power plant gas through a highly compact S-MGBF that uses cocurrent gas-pellet contacting in an arrangement that greatly simplifies and enhances the distribution of dirty gas to the moving bed and the disengagement of clean gas from the moving bed.

  5. Moving granular-bed filter development program. Topical report

    SciTech Connect (OSTI)

    Newby, R.A.; Yang, W.C.; Smeltzer, E.E.; Lippert, T.E.

    1994-04-01

    Advanced, coal-based, power plants, such as IGCC and Advanced-PFBC, are currently nearing commercial demonstration. These power plant technologies require hot gas filtration as part of their gas cleaning trains. Ceramic barrier filters are the major filter candidates being developed for these hot gas cleaning applications. While ceramic barrier filters achieve high levels of particle removal, concerns exist for their reliability and operability in these applications. An alternative hot gas filtration technology is the moving granular bed filter. An advanced, moving granular bed filter has been conceived, and early development activities performed by the Westinghouse Electric Corporation, Science and Technology Center. This document reports on the Base Contract tasks performed to resolve the barrier technical issues for this technology. The concept, the Standleg Moving Granular Bed Filter (SMGBF) has a concurrent downward, gas and bed media flow configuration that results in simplified features and improved scaleup feasibility compared to alternative designs. Two modes of bed media operation were assessed in the program: once-through using pelletized power plant waste as bed media, and recycle of bed media via standleg and pneumatic transport techniques. Cold Model testing; high-temperature, high-pressure testing; and pelletization testing using advanced power plant wastes, have been conducted in the program. A commercial, economic assessment of the SMGBF technology was performed for IGCC and Advanced-PFBC applications. The evaluation shows that the barrier technical issues can be resolved, and that the technology is potentially competitive with ceramic barrier filters.

  6. Universal Robotic Gripper based on the Jamming of Granular Material

    E-Print Network [OSTI]

    Eric Brown; Nicholas Rodenberg; John Amend; Annan Mozeika; Erik Steltz; Mitchell R. Zakin; Hod Lipson; Heinrich M. Jaeger

    2010-11-05

    Gripping and holding of objects are key tasks for robotic manipulators. The development of universal grippers able to pick up unfamiliar objects of widely varying shape and surface properties remains, however, challenging. Most current designs are based on the multi-fingered hand, but this approach introduces hardware and software complexities. These include large numbers of controllable joints, the need for force sensing if objects are to be handled securely without crushing them, and the computational overhead to decide how much stress each finger should apply and where. Here we demonstrate a completely different approach to a universal gripper. Individual fingers are replaced by a single mass of granular material that, when pressed onto a target object, flows around it and conforms to its shape. Upon application of a vacuum the granular material contracts and hardens quickly to pinch and hold the object without requiring sensory feedback. We find that volume changes of less than 0.5% suffice to grip objects reliably and hold them with forces exceeding many times their weight. We show that the operating principle is the ability of granular materials to transition between an unjammed, deformable state and a jammed state with solid-like rigidity. We delineate three separate mechanisms, friction, suction and interlocking, that contribute to the gripping force. Using a simple model we relate each of them to the mechanical strength of the jammed state. This opens up new possibilities for the design of simple, yet highly adaptive systems that excel at fast gripping of complex objects.

  7. Microscopic dissipation in a cohesionless granular jet impact

    E-Print Network [OSTI]

    Nicholas Guttenberg

    2012-03-29

    Sufficiently fine granular systems appear to exhibit continuum properties, though the precise continuum limit obtained can be vastly different depending on the particular system. We investigate the continuum limit of an unconfined, dense granular flow. To do this we use as a test system a two-dimensional dense cohesionless granular jet impinging upon a target. We simulate this via a timestep driven hard sphere method, and apply a mean-field theoretical approach to connect the macroscopic flow with the microscopic material parameters of the grains. We observe that the flow separates into a cone with an interior cone angle determined by the conservation of momentum and the dissipation of energy. From the cone angle we extract a dimensionless quantity $A-B$ that characterizes the flow. We find that this quantity depends both on whether or not a deadzone --- a stationary region near the target --- is present, and on the value of the coefficient of dynamic friction. We present a theory for the scaling of $A-B$ with the coefficient of friction that suggests that dissipation is primarily a perturbative effect in this flow, rather than the source of qualitatively different behavior.

  8. Stress Wave Anisotropy in Centered Square Highly Nonlinear Granular Systems A. Leonard and C. Daraio

    E-Print Network [OSTI]

    Daraio, Chiara

    material layer [9]. Regarding the ability to redirect stress wave energy, more complex y-shaped granular. Daraio Graduate Aerospace Laboratories (GALCIT), California Institute of Technology, Pasadena, California

  9. Method and means for continuous precipitation of easy-dry, granular uranium peroxide

    DOE Patents [OSTI]

    Cahill, Allen E. (Roland, IA); Burkhart, deceased, Lawrence E. (late of Ames, IA)

    1992-02-28

    A method and means for continuous precipitation of granular uranium peroxide. The reaction vessel and agitation method practiced in it avoid filter plugging and caking problems.

  10. Localization of Shear in Saturated Granular Media: Insights from a Multi-Scaled Granular-Fluid Model

    E-Print Network [OSTI]

    Aharonov, Einat; Sparks, David; Toussaint, Renaud

    2013-01-01

    The coupled mechanics of fluid-filled granular media controls the behavior of many natural systems such as saturated soils, fault gouge, and landslides. The grain motion and the fluid pressure influence each other: It is well established that when the fluid pressure rises, the shear resistance of fluid-filled granular systems decreases, and as a result catastrophic events such as soil liquefaction, earthquakes, and accelerating landslides may be triggered. Alternatively, when the pore pressure drops, the shear resistance of these systems increases. Despite the great importance of the coupled mechanics of grains-fluid systems, the basic physics that controls this coupling is far from understood. We developed a new multi-scaled model based on the discrete element method, coupled with a continuum model of fluid pressure, to explore this dynamical system. The model was shown recently to capture essential feedbacks between porosity changes arising from rearrangement of grains, and local pressure variations due to ...

  11. Evidence of local superconductivity in granular Bi nanowires fabricated by electrodeposition Mingliang Tian, Nitesh Kumar, and Moses H. W. Chan

    E-Print Network [OSTI]

    by electrodepositing Bi into porous polycarbonate membranes, showed granular morphology consisting of crystalline nanowires. In the 20 nonsuper- conducting granular wires we investigated, nine of them showed an unusual

  12. NonNewtonian Granular Fluids: Simulation and Theory Engineering Mechanics Unit, Jawaharlal Nehru Center for Advanced Scientific Research

    E-Print Network [OSTI]

    Luding, Stefan

    Non­Newtonian Granular Fluids: Simulation and Theory M. Alam Engineering Mechanics Unit, Jawaharlal properties of granular fluids are probed via event­driven simulations of the inelastic hard­sphere model. We find that granular fluids support large normal stress differences for the whole range of densities

  13. Non-Newtonian Granular Fluids: Simulation and Theory Engineering Mechanics Unit, Jawaharlal Nehru Center for Advanced Scientific Research

    E-Print Network [OSTI]

    Luding, Stefan

    Non-Newtonian Granular Fluids: Simulation and Theory M. Alam Engineering Mechanics Unit, Jawaharlal properties of granular fluids are probed via event-driven simulations of the inelastic hard-sphere model. We find that granular fluids support large normal stress differences for the whole range of densities

  14. Stationary shear ows of dense granular materials : a tentative continuum modelling

    E-Print Network [OSTI]

    . The granular stress is split into a rate-dependent part representing the rebound-less impacts between grains- ables. One could also suggest the uctuational kinetic energy of the grains (the granular "temperature, the collisional contribution is concerned with rebound-less impacts characteristic of high grain concen- tration

  15. Birth and growth of a granular jet John R. Royer,1

    E-Print Network [OSTI]

    Jaeger, Heinrich M.

    through a granular pack 8,9 and the functional form of the drag force on an object moving through a granu. This is demon- strated by the granular jet formed by the impact of a solid sphere into a bed of loose, fine sand is the result of an interplay between ambient gas, bed particles, and impacting sphere. Here we present

  16. Scaling and dynamics of sphere and disk impact into granular media Daniel I. Goldman*

    E-Print Network [OSTI]

    Goldman, Daniel I.

    on the sphere in the vicinity of these features leads to an experimentally based granular force model of the grains, g is the gravitational acceleration, and Fd is the drag force due to the presence of the granular medium. Im- pact models typically represent the drag force as the sum of two terms: Fd = Fz + v2 , 2

  17. The Mechanical Coupling of Fluid-Filled Granular Material Under Shear L. GOREN,1,2

    E-Print Network [OSTI]

    Einat, Aharonov

    The Mechanical Coupling of Fluid-Filled Granular Material Under Shear L. GOREN,1,2 E. AHARONOV,1 D. SPARKS,3 and R. TOUSSAINT 4 Abstract--The coupled mechanics of fluid-filled granular media controls of these geosystems increases. Despite the great importance of the coupled mechanics of grain­fluid systems, the basic

  18. Transport of a heated granular gas in a washboard potential Giulio Costantini

    E-Print Network [OSTI]

    Cecconi, Fabio

    in superconductors containing a periodic arrange- ment of defects,2,3 adsorption on crystal surfaces,4 super- ionic conduction,5 motion of molecular motors along microtubules,6 granular flows on rough inclined substrates,7 formulation, a granular system is a large number of particles grains colliding with one another and losing

  19. Spatial Resolution for Processing Seismic Data: Type-2 Methods for Finding the Relevant Granular Structure

    E-Print Network [OSTI]

    Kreinovich, Vladik

    Spatial Resolution for Processing Seismic Data: Type-2 Methods for Finding the Relevant Granular. NEED TO FIND GRANULARITY (SPATIAL RESOLUTION) OF THE RESULTS OF SEISMIC DATA PROCESSING In evaluations--One of the main methods of determining the Earth structure is the analysis of the seismic data. Based

  20. Pore pressure evolution in deforming granular material: A general formulation and the infinitely stiff approximation

    E-Print Network [OSTI]

    Einat, Aharonov

    Pore pressure evolution in deforming granular material: A general formulation and the infinitely of the granular network leads to pore fluid pressure (PP) changes. If the PP rises enough, the fluidfilled the two possible modes of pore fluid pressurization: (1) via rapid fluid flow when fluid drainage is good

  1. Cellular Responses in Sea Fan Corals: Granular Amoebocytes React to Pathogen and Climate Stressors

    E-Print Network [OSTI]

    Harvell, Catherine Drew

    Cellular Responses in Sea Fan Corals: Granular Amoebocytes React to Pathogen and Climate Stressors amoebocyte responses indicate that sea fan corals use cellular defenses to combat fungal infection SF, Peters EC, Harvell CD (2008) Cellular Responses in Sea Fan Corals: Granular Amoebocytes React

  2. Resistive transition anisotropy in superconducting granular ceramics: Interplay of effective medium approximation and percolation

    E-Print Network [OSTI]

    Strelniker, Yakov M.

    Resistive transition anisotropy in superconducting granular ceramics: Interplay of effective medium directions of the c axis, the current j and the magnetic field H in Bi2Sr2CaCu2O8 x ceramics. We provided in high-Tc superconduct- ing granular ceramics remain an intriguing subject of inten- sive investigations

  3. Pulsed Gradient Spin Echo Nuclear Magnetic Resonance Imaging of Diffusion in Granular Flow

    SciTech Connect (OSTI)

    Seymour, Joseph D.; Caprihan, Arvind; Altobelli, Stephen A.; Fukushima, Eiichi

    2000-01-10

    We derive the formalism to obtain spatial distributions of collisional correlation times for macroscopic particles undergoing granular flow from pulsed gradient spin echo nuclear magnetic resonance diffusion data. This is demonstrated with an example of axial motion in the shear flow regime of a 3D granular flow in a horizontal rotating cylinder at one rotation rate. (c) 2000 The American Physical Society.

  4. Granular front formation in free-surface flow of concentrated suspensions

    E-Print Network [OSTI]

    Leonardi, A; Wittel, F K; Kaitna, R; Mendoza, M; Wu, W; Herrmann, H J

    2015-01-01

    Granular fronts are a common yet unexplained phenomenon emerging during the gravity driven free-surface flow of concentrated suspensions. They are usually believed to be the result of fluid convection in combination with particle size segregation. However, suspensions composed of uniformly sized particles also develop a granular front. Within a large rotating drum, a stationary recirculating avalanche is generated. The flowing material is a mixture of a visco-plastic fluid obtained from a kaolin-water dispersion, with spherical ceramic particles denser than the fluid. The goal is to mimic the composition of many common granular-fluid materials, like fresh concrete or debris flow. In these materials, granular and fluid phases have the natural tendency to segregate due to particle settling. However, through the shearing caused by the rotation of the drum, a reorganization of the phases is induced, leading to the formation of a granular front. By tuning the material properties and the drum velocity, it is possib...

  5. Note: "Lock-in accelerometry" to follow sink dynamics in shaken granular matter

    E-Print Network [OSTI]

    Sánchez-Colina, G; Martínez-Román, E; Batista-Leyva, A J; Clement, C; Fliedner, C; Toussaint, R; Altshuler, E

    2015-01-01

    Understanding the penetration dynamics of intruders in granular beds is relevant not only for fundamental Physics, but also for geophysical processes and construction on sediments or granular soils in areas potentially affected by earthquakes. While the penetration of intruders in two dimensional (2D) laboratory granular beds can be followed using video recording, it is useless in three dimensional (3D) beds of non-transparent materials such as common sand. Here we propose a method to quantify the sink dynamics of an intruder into laterally shaken granular beds based on the temporal correlations between the signals from a reference accelerometer fixed to the shaken granular bed, and a probe accelerometer deployed inside the intruder. Due to its analogy with the working principle of a lock in amplifier, we call this technique Lock in accelerometry (LIA). During Earthquakes, some soils can lose their ability to sustain shear and deform, causing subsidence and sometimes substantial building damage due to deforma...

  6. Note: "Lock-in accelerometry" to follow sink dynamics in shaken granular matter

    E-Print Network [OSTI]

    G. Sánchez-Colina; L. Alonso-Llanes; E. Martínez-Román; A. J. Batista-Leyva; C. Clement; C. Fliedner; R. Toussaint; E Altshuler

    2015-09-14

    Understanding the penetration dynamics of intruders in granular beds is relevant not only for fundamental Physics, but also for geophysical processes and construction on sediments or granular soils in areas potentially affected by earthquakes. While the penetration of intruders in two dimensional (2D) laboratory granular beds can be followed using video recording, it is useless in three dimensional (3D) beds of non-transparent materials such as common sand. Here we propose a method to quantify the sink dynamics of an intruder into laterally shaken granular beds based on the temporal correlations between the signals from a reference accelerometer fixed to the shaken granular bed, and a probe accelerometer deployed inside the intruder. Due to its analogy with the working principle of a lock in amplifier, we call this technique Lock in accelerometry (LIA). During Earthquakes, some soils can lose their ability to sustain shear and deform, causing subsidence and sometimes substantial building damage due to deformation or tumbling

  7. Method for reducing iron losses in an iron smelting process

    DOE Patents [OSTI]

    Sarma, Balu (Airmont, NY); Downing, Kenneth B. (Greenville, SC)

    1999-01-01

    A process of smelting iron that comprises the steps of: a) introducing a source of iron oxide, oxygen, nitrogen, and a source of carbonaceous fuel to a smelting reactor, at least some of said oxygen being continuously introduced through an overhead lance; b) maintaining conditions in said reactor to cause (i) at least some of the iron oxide to be chemically reduced, (ii) a bath of molten iron to be created and stirred in the bottom of the reactor, surmounted by a layer of slag, and (iii) carbon monoxide gas to rise through the slag; c) causing at least some of said carbon monoxide to react in the reactor with the incoming oxygen, thereby generating heat for reactions taking place in the reactor; and d) releasing from the reactor an offgas effluent, is run in a way that keeps iron losses in the offgas relatively low. After start-up of the process is complete, steps (a) and (b) are controlled so as to: e) keep the temperature of the molten iron at or below about 1550.degree. C. and f) keep the slag weight at or above about 0.8 tonne per square meter.

  8. Energy Transport in a One-Dimensional Granular Gas

    E-Print Network [OSTI]

    Italo Ivo Lima Dias Pinto; Alexandre Rosas; Katja Lindenberg

    2009-02-13

    We study heat conduction in one-dimensional granular gases. In particular, we consider two mechanisms of viscous dissipation during inter-grain collisions. In one, the dissipative force is proportional to the grain's velocity and dissipates not only energy but also momentum. In the other, the dissipative force is proportional to the relative velocity of the grains and therefore conserves momentum even while dissipating energy. This allows us to explore the role of momentum conservation in the heat conduction properties of this one-dimensional nonlinear system. We find normal thermal conduction whether or not momentum is conserved.

  9. The nature of quasistatic deformation in granular materials

    E-Print Network [OSTI]

    Jean-Noël Roux

    2009-01-15

    Strain in granular materials in quasistatic conditions under varying stress originate in (I) contact deformation and (II) rearrangements of the contact network. Depending on sample history and applied load, either mechanism might dominate. One may thus define rheological regimes I and II accordingly. Their properties are presented and illustrated here with discrete numerical simulation results on sphere packings. Understanding the microscopic physical origin of strain enables one to clarify such issues as the existence of macroscopic elasticity, the approach to stress-strain relations in the large system limit and the sensitivity to noise.

  10. Shear zone refraction and deflection in layered granular materials

    E-Print Network [OSTI]

    Tamas Borzsonyi; Tamas Unger; Balazs Szabo

    2009-12-09

    Refraction and deflection of shear zones in layered granular materials was studied experimentally and numerically. We show, that (i) according to a recent theoretical prediction [T. Unger, Phys. Rev. Lett. 98, 018301 (2007)] shear zones refract in layered systems in analogy with light refraction, (ii) zone refraction obeys Snell's law known from geometric optics and (iii) under natural pressure conditions (i.e. in the presence of gravity) the zone can also be deflected by the interface so that the deformation of the high friction material is avoided.

  11. KNOTS AND RANDOM WALKS IN VIBRATED GRANULAR CHAINS

    SciTech Connect (OSTI)

    E. BEN-NAIM; ET AL

    2000-08-01

    The authors study experimentally statistical properties of the opening times of knots in vertically vibrated granular chains. Our measurements are in good qualitative and quantitative agreement with a theoretical model involving three random walks interacting via hard core exclusion in one spatial dimension. In particular, the knot survival probability follows a universal scaling function which is independent of the chain length, with a corresponding diffusive characteristic time scale. Both the large-exit-time and the small-exit-time tails of the distribution are suppressed exponentially, and the corresponding decay coefficients are in excellent agreement with the theoretical values.

  12. Transport Coefficients for the Hard Sphere Granular Fluid

    E-Print Network [OSTI]

    Aparna Baskaran; James W. Dufty; J. Javier Brey

    2006-12-15

    In the preceding paper, linear response methods have been applied to obtain formally exact expressions for the parameters of Navier-Stokes order hydrodynamics. The analysis there is general, applying to both normal and granular fluids with a wide range of collision rules. Those results are specialized here to the case of smooth, inelastic hard spheres with constant coefficient of normal restitution, for further elaboration. Explicit expressions for the cooling rate, pressure, and the transport coefficients are given and compared with the corresponding expressions for a system of elastic hard spheres. The scope of the results for further analytical explorations and possible numerical evaluation is discussed.

  13. Analysis of the velocity field of granular hopper flow

    E-Print Network [OSTI]

    F. G. R. Magalhães; A. P. F. Atman; J. G. Moreira; H. J. Herrmann

    2015-07-22

    We report the analysis of radial characteristics of the flow of granular material through a conical hopper. The discharge is simulated for various orifice sizes and hopper opening angles. Velocity profiles are measured along two radial lines from the hopper cone vertex: along the main axis of the cone and along its wall. An approximate power law dependence on the distance from the orifice is observed for both profiles, although differences between them can be noted. In order to quantify these differences, we propose a Local Mass Flow index that is a promising tool in the direction of a more reliable classification of the flow regimes in hoppers.

  14. The building blocks of dynamical heterogeneities in dense granular media

    E-Print Network [OSTI]

    R. Candelier; O. Dauchot; G. Biroli

    2009-01-22

    We investigate experimentally the connection between short time dynamics and long time dynamical heterogeneities within a dense granular media under cyclic shear. We show that dynamical heterogeneities result from a two timescales process. Short time but already collective events consisting in clustered cage jumps concentrate most of the non affine displacements. On larger timescales such clusters appear aggregated both temporally and spatially in avalanches which eventually build the large scales dynamical heterogeneities. Our results indicate that facilitation plays an important role in the relaxation process although it does not appear to be conserved as proposed in many models studied in the literature.

  15. Short Pulse Dynamics in Strongly Nonlinear Dissipative Granular Chains

    E-Print Network [OSTI]

    Alexandre Rosas; Aldo H. Romero; Vitali F. Nesterenko; Katja Lindenberg

    2008-08-04

    We study the energy decay properties of a pulse propagating in a strongly nonlinear granular chain with damping proportional to the relative velocity of the grains. We observe a wave disturbance that at low viscosities consists of two parts exhibiting two entirely different time scales of dissipation. One part is an attenuating solitary wave, is dominated by discreteness and nonlinearity effects as in a dissipationless chain, and has the shorter lifetime. The other is a purely dissipative shocklike structure with a much longer lifetime and exists only in the presence of dissipation. The range of viscosities and initial configurations that lead to this complex wave disturbance are explored.

  16. Fractal dimension analysis in a highly granular calorimeter

    E-Print Network [OSTI]

    Ruan, M; Brient, J.C; Jeans, D; Videau, H

    2015-01-01

    The concept of “particle flow” has been developed to optimise the jet energy resolution by distinguishing the different jet components. A highly granular calorimeter designed for the particle flow algorithm provides an unprecedented level of detail for the reconstruction of calorimeter showers and enables new approaches to shower analysis. In this paper the measurement and use of the fractal dimension of showers is described. The fractal dimension is a characteristic number that measures the global compactness of the shower. It is highly dependent on the primary particle type and energy. Its application in identifying particles and estimating their energy is described in the context of a calorimeter designed for the International Linear Collider.

  17. Arrest stress of uniformly sheared wet granular matter

    E-Print Network [OSTI]

    S. H. Ebrahimnazhad Rahbari; M. Brinkmann; J. Vollmer

    2015-06-21

    We conduct extensive independent numerical experiments considering frictionless disks without internal degrees of freedom (rotation etc.) in two dimensions. We report here that for a large range of the packing fractions below random-close packing, all components of the stress tensor of wet granular materials remain finite in the limit of zero shear rate. This is direct evidence for a fluid-to-solid arrest transition. The offset value of the shear stress characterizes plastic deformation of the arrested state {which corresponds to {\\em dynamic yield stress} of the system}. {Based on an analytical line of argument, we propose that the mean number of capillary bridges per particle, $\

  18. A Maxwell Construction for Phase Separation in Vibrated Granular Matter?

    E-Print Network [OSTI]

    James P. D. Clewett; Jack Wade; R. M. Bowley; Stephan Herminghaus; Michael R. Swift; Marco G. Mazza

    2015-02-28

    Experiments and computer simulations are carried out to investigate ordering principles in a granular gas which phase separates under vibration. The densities of the dilute and the dense phase are found to follow a lever rule. A Maxwell construction is found to predict both the coexisting pressure and binodal densities remarkably well, despite the fact that the pressure-volume characteristic $P(v)$ is not an isotherm. Although the system is far from equilibrium and energy conservation is strongly violated, we derive the construction from the minimization of mechanical work and fluctuating particle currents.

  19. Iron catalyzed coal liquefaction process

    DOE Patents [OSTI]

    Garg, Diwakar (Macungie, PA); Givens, Edwin N. (Bethlehem, PA)

    1983-01-01

    A process is described for the solvent refining of coal into a gas product, a liquid product and a normally solid dissolved product. Particulate coal and a unique co-catalyst system are suspended in a coal solvent and processed in a coal liquefaction reactor, preferably an ebullated bed reactor. The co-catalyst system comprises a combination of a stoichiometric excess of iron oxide and pyrite which reduce predominantly to active iron sulfide catalysts in the reaction zone. This catalyst system results in increased catalytic activity with attendant improved coal conversion and enhanced oil product distribution as well as reduced sulfide effluent. Iron oxide is used in a stoichiometric excess of that required to react with sulfur indigenous to the feed coal and that produced during reduction of the pyrite catalyst to iron sulfide.

  20. Process for the synthesis of iron powder

    DOE Patents [OSTI]

    Welbon, William W. (Belleair, FL)

    1983-01-01

    A process for preparing iron powder suitable for use in preparing the iron-potassium perchlorate heat-powder fuel mixture used in thermal batteries, comprises preparing a homogeneous, dense iron oxide hydroxide precipitate by homogeneous precipitation from an aqueous mixture of a ferric salt, formic or sulfuric acid, ammonium hydroxide and urea as precipitating agent; and then reducing the dense iron oxide hydroxide by treatment with hydrogen to prepare the iron powder.

  1. Process for the synthesis of iron powder

    DOE Patents [OSTI]

    Welbon, W.W.

    1983-11-08

    A process for preparing iron powder suitable for use in preparing the iron-potassium perchlorate heat-powder fuel mixture used in thermal batteries, comprises preparing a homogeneous, dense iron oxide hydroxide precipitate by homogeneous precipitation from an aqueous mixture of a ferric salt, formic or sulfuric acid, ammonium hydroxide and urea as precipitating agent; and then reducing the dense iron oxide hydroxide by treatment with hydrogen to prepare the iron powder. 2 figs.

  2. Process for the synthesis of iron powder

    DOE Patents [OSTI]

    Not Available

    1982-03-06

    A process for preparing iron powder suitable for use in preparing the iron-potassium perchlorate heat-powder fuel mixture used in thermal batteries, comprises preparing a homogeneous, dense iron oxide hydroxide precipitate by homogeneous precipitation from an aqueous mixture of a ferric salt, formic or sulfuric acid, ammonium hydroxide and urea as precipitating agent; and then reducing the dense iron oxide hydroxide by treatment with hydrogen to prepare the iron powder.

  3. Explorations of iron-iron hydrogenase active site models by experiment and theory 

    E-Print Network [OSTI]

    Tye, Jesse Wayne

    2009-05-15

    This dissertation describes computational and experimental studies of synthetic complexes that model the active site of the iron-iron hydrogenase [FeFe]H2ase enzyme. Simple dinuclear iron dithiolate complexes act as functional models of the ironiron...

  4. Westinghouse standleg moving granular bed filter development program

    SciTech Connect (OSTI)

    Newby, R.A.; Yang, W.C.; Smeltzer, E.E.; Lippert, T.E.

    1994-10-01

    Advanced, coal-based, power plants, such as IGCC and Advanced-PFBC, are currently nearing commercial demonstration. These power plant technologies require hot gas filtration as part of their gas cleaning trains. Ceramic barrier filters are the major filter candidates being developed for these hot gas cleaning applications. While ceramic barrier filters achieve high levels of particle removal, there are concerns for their reliability and operability. An alternative hot gas filtration technology is the moving granular bed filter. These systems are at a lower state of development than ceramic barrier filters, and their effectiveness as filters is still in question. Their apparent attributes, result from their much less severe mechanical design and materials constraints, and the potential for more reliable, failure-free particle removal operation. The standleg moving granular-bed filter (SMGBF) system, is a compact unit that uses cocurrent gas-pellet contacting in an arrangement that greatly simplifies and enhances the distribution of dirty, process gas to the moving bed and allows effective disengagement of clean gas from the moving bed. This paper describes the equipment and process test results.

  5. Temporal analysis of acoustic emission from a plunged granular bed

    E-Print Network [OSTI]

    Daisuke Tsuji; Hiroaki Katsuragi

    2015-09-18

    The statistical property of acoustic emission (AE) events from a plunged granular bed is analyzed by means of actual time and natural time analyses. These temporal analysis methods allow us to investigate the details of AE events that follow a power-law distribution. In the actual time analysis, the calm time distribution and the decay of the event-occurrence density after the largest event (i.e., Omori-Utsu law) are measured. Although the former always shows a power-law form, the latter does not always obey a power law. Markovianity of the event-occurrence process is also verified using a scaling law by assuming that both of them exhibit power laws. We find that the effective shear strain rate is a key parameter to classify the emergence rate of power-law nature and Markovianity in the granular AE events. For the natural time analysis, the existence of self organized critical (SOC) states is revealed by calculating the variance of natural time $\\chi_k$, where $k$th natural time of N events is defined as $\\chi_k=k/N$. In addition, the energy difference distribution can be fitted by a $q$-Gaussian form, which is also consistent with the criticality of the system.

  6. Invited review: Clogging of granular materials in bottlenecks

    E-Print Network [OSTI]

    Iker Zuriguel

    2014-12-18

    During the past decades, notable improvements have been achieved in the understanding of static and dynamic properties of granular materials, giving rise to appealing new concepts like jamming, force chains, non-local rheology or the inertial number. The `saltcellar' can be seen as a canonical example of the characteristic features displayed by granular materials: an apparently smooth flow is interrupted by the formation of a mesoscopic structure (arch) above the outlet that causes a quick dissipation of all the kinetic energy within the system. In this manuscript, I will give an overview of this field paying special attention to the features of statistical distributions appearing in the clogging and unclogging processes. These distributions are essential to understand the problem and allow subsequent study of topics such as the influence of particle shape, the structure of the clogging arches and the possible existence of a critical outlet size above which the outpouring will never stop. I shall finally offer some hints about general ideas that can be explored in the next few years.

  7. Onset and cessation of motion in hydrodynamically sheared granular beds

    E-Print Network [OSTI]

    Abram H. Clark; Mark D. Shattuck; Nicholas T. Ouellette; Corey S. O'Hern

    2015-10-06

    We performed molecular dynamics simulations of granular beds driven by a model hydrodynamic shear flow to elucidate general grain-scale mechanisms that determine the onset and cessation of sediment transport. By varying the Shields number (the nondimensional shear stress at the top of the bed) and particle Reynolds number (the ratio of particle inertia to viscous damping), we explore how variations of the fluid flow rate, particle inertia, and fluid viscosity affect the onset and cessation of bed motion. For low to moderate particle Reynolds numbers, a critical boundary separates mobile and static states. Transition times between these states diverge as this boundary is approached both from above and below. At high particle Reynolds number, inertial effects become dominant, and particle motion can be sustained well below flow rates at which mobilization of a static bed occurs. We also find that the onset of bed motion (for both low and high particle Reynolds numbers) is described by Weibullian weakest-link statistics, and thus is crucially dependent on the packing structure of the granular bed, even deep beneath the surface.

  8. Energy transport in one-dimensional disordered granular solids

    E-Print Network [OSTI]

    V. Achilleos; G. Theocharis; Ch. Skokos

    2015-09-11

    We investigate the energy transport in one-dimensional disordered granular solids by extensive numerical simulations. In particular, we consider the case of a granular chain composed of spherical beads of the same material and with radii taken from a random distribution. We start by examining the linear limit, in which it is known that the energy transport strongly depends on the type of initial conditions. Thus, we consider two sets of initial conditions: i) an initial displacement and ii) an initial momentum excitation of a single bead. After establishing the regime of sufficiently strong disorder, we focus our studies on the role of nonlinearity for both sets of initial conditions. By increasing the initial excitation amplitudes we are able to identify three distinct dynamical regimes with different energy transport properties: a near linear, a weakly nonlinear and a highly nonlinear regime. Although energy spreading is found to be increasing for higher nonlinearities, in the weakly nonlinear regime no clear asymptotic behavior of the spreading is found. In this regime, we additionally find that energy, initially trapped in a localized region, can be eventually detrapped and this has a direct influence on the fluctuations of the energy spreading. We also demonstrate that in the highly nonlinear regime, the differences in energy transport between the two sets of initial conditions vanish. Actually, in this regime the energy is almost ballistically transported through shock-like excitations.

  9. Jet-induced jammed states of granular jet impacts

    E-Print Network [OSTI]

    Tomohiko G. Sano; Hisao Hayakawa

    2013-08-17

    The impacts of granular jets for both frictional and frictionless grains in two dimensions are numerically investigated. A dense flow with a dead zone emerges during the impact. From our two-dimensional simulation, we evaluate the equations of state and the con- stitutive equations of the flow. The asymptotic divergences of pressure and shear stress similar to the situation near the jamming transition appear for the frictionless case, while their exponents are smaller than those of the sheared granular systems, and are close to the extrapolation from the kinetic theoretical regime. In a similar manner to the jam- ming for frictional grains, the critical density decreases as the friction constant of grains increases. For bi-disperse systems, the effective friction constant defined as the ratio of shear stress to normal stress, monotonically increases from near zero, as the strain rate increases. On the other hand, the effective friction constant has two metastable branches for mono-disperse systems because of the coexistence of a crystallized state and a liquid state.

  10. Energy transport in one-dimensional disordered granular solids

    E-Print Network [OSTI]

    V. Achilleos; G. Theocharis; Ch. Skokos

    2015-12-06

    We investigate the energy transport in one-dimensional disordered granular solids by extensive numerical simulations. In particular, we consider the case of a polydisperse granular chain composed of spherical beads of the same material and with radii taken from a random distribution. We start by examining the linear case, in which it is known that the energy transport strongly depends on the type of initial conditions. Thus, we consider two sets of initial conditions: i) an initial displacement and ii) an initial momentum excitation of a single bead. After establishing the regime of sufficiently strong disorder, we focus our studies on the role of nonlinearity for both sets of initial conditions. By increasing the initial excitation amplitudes we are able to identify three distinct dynamical regimes with different energy transport properties: a near linear, a weakly nonlinear and a highly nonlinear regime. Although energy spreading is found to be increasing for higher nonlinearities, in the weakly nonlinear regime no clear asymptotic behavior of the spreading is found. In this regime, we additionally find that energy, initially trapped in a localized region, can be eventually detrapped and this has a direct influence on the fluctuations of the energy spreading. We also demonstrate that in the highly nonlinear regime, the differences in energy transport between the two sets of initial conditions vanish. Actually, in this regime the energy is almost ballistically transported through shock-like excitations.

  11. Gas-Mediated Impact Dynamics in Fine-Grained Granular Materials

    E-Print Network [OSTI]

    John R. Royer; Eric I. Corwin; Peter J. Eng; Heinrich M. Jaeger

    2007-07-17

    Non-cohesive granular media exhibit complex responses to sudden impact that often differ from those of ordinary solids and liquids. We investigate how this response is mediated by the presence of interstitial gas between the grains. Using high-speed x-ray radiography we track the motion of a steel sphere through the interior of a bed of fine, loose granular material. We find a crossover from nearly incompressible, fluid-like behavior at atmospheric pressure to a highly compressible, dissipative response once most of the gas is evacuated. We discuss these results in light of recent proposals for the drag force in granular media.

  12. Rare Iron Oxide in Ancient Chinese Pottery

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Rare Iron Oxide in Ancient Chinese Pottery Rare Iron Oxide in Ancient Chinese Pottery Print Friday, 26 September 2014 14:37 Jian ware (or Tenmoku) ceramic bowls, famous for their...

  13. Correcting Iron Deficiencies in Grain Sorghum 

    E-Print Network [OSTI]

    Livingston, Stephen; Coffman, Cloyce G.; Unruh, L. G.

    1996-02-20

    Until grain sorghum develops an extensive root system, young plants may be unable to obtain enough ferrous iron to maintain normal growth. This publication offers strategies for avoiding, identifying and correcting iron deficiencies....

  14. Fluctuations of internal energy flow in a vibrated granular gas

    E-Print Network [OSTI]

    A. Puglisi; P. Visco; A. Barrat; E. Trizac; F. van Wijland

    2005-09-05

    The non-equilibrium fluctuations of power flux in a fluidized granular media have been recently measured in an experiment [Phys. Rev. Lett. 92, 164301, 2004], which was announced to be a verification of the Fluctuation Relation (FR) by Gallavotti and Cohen. An effective temperature was also identified and proposed to be a useful probe for such non equilibrium systems. We explain these results in terms of a two temperature Poisson process. Within this model, supported by independent Molecular Dynamics simulations, power flux fluctuations do not satisfy the FR and the nature of the effective temperature is clarified. In the pursue of a hypothetical global quantity fulfilling the FR, this points to the need of considering other candidates than the power flux.

  15. $1/f$ noise on the brink of wet granular melting

    E-Print Network [OSTI]

    Kai Huang

    2015-07-23

    The collective behavior of a two-dimensional wet granular cluster under horizontal swirling motions is investigated experimentally. Depending on the balance between the energy injection and dissipation, the cluster evolves into various nonequilibrium stationary states with strong internal structure fluctuations with time. Quantitative characterizations of the fluctuations with the bond orientational order parameter $q_{\\rm 6}$ reveal power spectra of the form $f^{\\alpha}$ with the exponent $\\alpha$ closely related to the stationary states of the system. In particular, $1/f$ type of noise with $\\alpha\\approx-1$ emerges as melting starts from the free surface of the cluster, suggesting the possibility of using $1/f$ noise as an indicator for phase transitions in systems driven far from thermodynamic equilibrium.

  16. Evolution of dynamical facilitation approaching the granular glass transition

    E-Print Network [OSTI]

    R. Candelier; O. Dauchot; G. Biroli

    2009-12-02

    We investigate the relaxation dynamics of a dense monolayer of bidisperse beads by analyzing the experimental data previously obtained in a fluidized bed. We show that the dynamics is formed by elementary relaxation events called cage jumps. These aggregate on a very short time into clusters. Increasing the packing fraction makes the spatio-temporal organization of the clusters evolve from a rather scattered and random distribution towards a collection of sparse and large events, called avalanches. The avalanche process is a manifestation of dynamical facilitation. The study of its evolution with density reveals that dynamical facilitation becomes less conserved and play a lesser role for the structural relaxation approaching the granular glass transition.

  17. Hydrodynamic instabilities in shear flows of cohesive granular particles

    E-Print Network [OSTI]

    Kuniyasu Saitoh; Satoshi Takada; Hisao Hayakawa

    2015-05-15

    We extend the dynamic van der Waals model introduced by A. Onuki [Phys. Rev. Lett. 94, 054501 (2005)] to the description of cohesive granular flows under a plane shear to study their hydrodynamic instabilities. Numerically solving the dynamic van der Waals model, we observe various heterogeneous structures of the density in steady states, where the viscous heating is balanced with the energy dissipation caused by inelastic collisions. Based on the linear stability analysis, we find that the spatial structures are determined by the mean volume fraction, the applied shear rate, and the inelasticity, where the instability is triggered if the system is thermodynamically unstable, i.e. the pressure, $p$, and the volume fraction, $\\phi$, satisfy $\\partial p/\\partial\\phi<0$.

  18. Charging effects and quantum crossover in granular superconductors

    SciTech Connect (OSTI)

    Granato, E. (LAS, Instituto Nacional de Pesquisas Espaciais, 12.225 Sao Jose dos Campos, Sao Paulo (Brazil)); Continentino, M.A. (Instituto de Fisica, Universidade Federal Fluminense, Outeiro de S.J. Batista s/n, Niteroi, 24.020, Rio de Janeiro (Brazil))

    1993-12-01

    The effects of the charging energy in the superconducting transition of granular materials or Josephson-junction arrays are investigated using a pseudo-spin-one model. Within a mean-field renormalization-group approach, we obtain the phase diagram as a function of temperature and charging energy. In contrast to earlier treatments, we find no sign of a reentrant transition in agreement with more recent studies. A crossover line is identified in the nonsuperconducting side of the phase diagram and along which we expect to observe anomalies in the transport and thermodynamic properties. We also study a charge ordering phase, which can appear for large nearest-neighbor Coulomb interaction, and show that it leads to first-order transitions at low temperatures. We argue that, in the presence of charge ordering, a nonmonotonic behavior with decreasing temperature is possible with a maximum in the resistance just before entering the superconducting phase.

  19. Laboratory variables for assessing iron deficiency in REDS-II Iron Status Evaluation (RISE) blood donors

    E-Print Network [OSTI]

    2013-01-01

    value overall. Use of ancillary testing in this manner couldthan iron deficiency. Ancillary tests (especially ferritin

  20. Mechanisms size segregation binary granular mixture Matthias Schrter,* Stephan Ulrich, Jennifer Kreft, Jack Swift, Harry

    E-Print Network [OSTI]

    Mechanisms size segregation binary granular mixture Matthias Schröter,* Stephan Ulrich, Jennifer mechanisms have been suggested explain when each segregation observed. However, dependence of mechanisms number mechanisms consid­ ered seven. observe both BNE RBNE varying systematically driving frequency

  1. Shape and dynamics of seepage erosion in a horizontal granular bed

    E-Print Network [OSTI]

    Berhanu, Michael

    We investigate erosion patterns observed in a horizontal granular bed resulting from seepage of water motivated by observation of beach rills and channel growth in larger scale land forms. Our experimental apparatus consists ...

  2. Discrete Breathers in One-Dimensional Diatomic Granular Crystals N. Boechler,1

    E-Print Network [OSTI]

    Daraio, Chiara

    but also for the implementation of engineering applications, including shock and energy absorbing layers- standing and controlling localization in granular crystals might lead to new energy-harvesting or filtering

  3. Discrete breathers and intrinsic energy localization in one-dimensional diatomic granular crystals

    E-Print Network [OSTI]

    Porter, Mason A.

    materials but also for the implementation of engineering applications, including shock and energy absorbing and controlling energy localization in granular crystals might lead to new energy-harvesting or filtering devices

  4. Study of granular temperature in dense fluidized beds by diffusing wave spectroscopy 

    E-Print Network [OSTI]

    Zivkovic, Vladimir

    2009-01-01

    Diffusing wave spectroscopy (DWS), a non-intrusive multiple scattering technique, can be used to study the fundamentals of particle motion in dynamic dense granular media and measure the mean of the square of the particle ...

  5. Study of gas flow dynamics in porous and granular media with laser-polarized ¹²?Xe NMR

    E-Print Network [OSTI]

    Wang, Ruopeng, 1972-

    2005-01-01

    This thesis presents Nuclear Magnetic Resonance (NMR) studies of gas flow dynamics in porous and granular media by using laser-polarized ¹²?Xe . Two different physical processes, the gas transport in porous rock cores and ...

  6. Effective moduli of granular and layered composites with piezoelectric constituents Tamara Olsony and Marco Avellanedaz

    E-Print Network [OSTI]

    Olson, Tamara

    made from piezoelectric materials are examined, with particular emphasis on applications to unpoledEffective moduli of granular and layered composites with piezoelectric constituents Tamara Olsony piezoelectric ceramics and layered materials. Explicit formulae for the effective moduli and coupling

  7. Study on Granular Dynamics in Vertically Vibrated Beds using Tracking Technique

    E-Print Network [OSTI]

    Wong, Yee Sun

    The study of granular material is of great interest to many researchers in both engineering and science communities. The importance of such a study derives from its complex rheological character and also its significant ...

  8. Arch-based configurations in the volume ensemble of static granular systems

    E-Print Network [OSTI]

    D. Slobinsky; Luis A. Pugnaloni

    2014-11-27

    We propose an alternative approach to count the microscopic static configurations of granular packs under gravity by considering arches. This strategy simplifies the problem of filtering out configurations that are not mechanically stable, opening the way for a range of granular models to be studied via ensemble theory. Following this arch-based approach, we have obtained the exact density of states for a two-dimensional non-interacting rigid arch model of granular assemblies. The calculated arch size distribution and volume fluctuations show qualitative agreement with realistic simulations of tapped granular beds. We have also validated our calculations by comparing with the analytic solution for the limiting case of a quasi-one-dimensional column of frictionless disks.

  9. Granular rotor as a probe for a non-equilibrium bath

    E-Print Network [OSTI]

    Tomohiko G. Sano; Kiyoshi Kanazawa; Hisao Hayakawa

    2015-11-27

    The dynamics of a rotor under viscous or dry friction is investigated as a non-equilibrium probe of a granular gas numerically and analytically. To demonstrate a role of the rotor as a probe for a non-equilibrium bath, we perform the molecular dynamics (MD) simulation of the rotor under viscous or dry friction surrounded by a steady granular gas under gravity. We theoretically derive a one-to-one map between the velocity distribution function (VDF) for the granular gas and the angular one for the rotor. With the aid of the MD simulation, we demonstrate that the one-to-one map works well to infer the local VDF of the granular gas from the angular one of the rotor, and vice versa.

  10. Evolution of a non-cohesive granular bed subject to a succession of erosive turbidity currents

    E-Print Network [OSTI]

    Rangel, Roberto Carlos

    2006-01-01

    An experiment was performed to study the evolution of a non-cohesive granular bed subject to a succession of erosive turbidity currents to evaluate the applicability of a proposed interface model that prescribes a relationship ...

  11. Depletion forces drive polymer-like self-assembly in vibrofluidized granular Jennifer Galanis,*ab

    E-Print Network [OSTI]

    Harries, Daniel

    to 2D environments. It is unclear, however, if self-assembly principles governing thermally, entropy driven, order­disorder type phase transitions and steady-state granular experiments,17­21 even

  12. Granular front formation in free-surface flow of concentrated suspensions

    E-Print Network [OSTI]

    A. Leonardi; M. Cabrera; F. K. Wittel; R. Kaitna; M. Mendoza; W. Wu; H. J. Herrmann

    2015-02-19

    Granular fronts are a common yet unexplained phenomenon emerging during the gravity driven free-surface flow of concentrated suspensions. They are usually believed to be the result of fluid convection in combination with particle size segregation. However, suspensions composed of uniformly sized particles also develop a granular front. Within a large rotating drum, a stationary recirculating avalanche is generated. The flowing material is a mixture of a visco-plastic fluid obtained from a kaolin-water dispersion, with spherical ceramic particles denser than the fluid. The goal is to mimic the composition of many common granular-fluid materials, like fresh concrete or debris flow. In these materials, granular and fluid phases have the natural tendency to segregate due to particle settling. However, through the shearing caused by the rotation of the drum, a reorganization of the phases is induced, leading to the formation of a granular front. By tuning the material properties and the drum velocity, it is possible to control this phenomenon. The setting is reproduced in a numerical environment, where the fluid is solved by a Lattice-Boltzmann Method, and the particles are explicitly represented using the Discrete Element Method. The simulations confirm the findings of the experiments, and provide insight into the internal mechanisms. Comparing the time-scale of particle settling with the one of particle recirculation, a non-dimensional number is defined, and is found to be effective in predicting the formation of a granular front.

  13. Stress-dependent normal mode frequencies from the effective mass of granular matter

    E-Print Network [OSTI]

    Yanqing Hu; David L. Johnson; John J. Valenza; Francisco Santibanez; Hernán A. Makse

    2014-10-20

    A zero-temperature critical point has been invoked to control the anomalous behavior of granular matter as it approaches jamming or mechanical arrest. Criticality manifests itself in an anomalous spectrum of low-frequency normal modes and scaling behavior near the jamming transition. The critical point may explain the peculiar mechanical properties of dissimilar systems such as glasses and granular materials. Here, we study the critical scenario via an experimental measurement of the normal modes frequencies of granular matter under stress from a pole decomposition analysis of the effective mass. We extract a complex-valued characteristic frequency which displays scaling $|\\omega^*(\\sigma)|\\sim\\sigma^{\\Omega'}$ with vanishing stress $\\sigma$ for a variety of granular systems. The critical exponent is smaller than that predicted by mean-field theory opening new challenges to explain the exponent for frictional and dissipative granular matter. Our results shed light on the anomalous behavior of stress-dependent acoustics and attenuation in granular materials near the jamming transition.

  14. Iron production maintenance effectiveness system

    SciTech Connect (OSTI)

    Augstman, J.J. [Dofasco Inc., Hamilton, Ontario (Canada)

    1996-12-31

    In 1989, an internal study in the Coke and Iron Maintenance Department identified the opportunities available to increase production, by decreasing unscheduled maintenance delays from 4.6%. A five year front loaded plan was developed, and presented to the company president. The plan required an initial investment of $1.4 million and a conservative break-even point was calculated to be 2.5 years. Due to budget restraints, it would have to be self-funded, i.e., generate additional production or savings, to pay for the program. The program began in 1991 at number 2 coke plant and the blast furnaces. This paper will describe the Iron Production Maintenance Effectiveness System (ME), which began with the mechanical and pipefitting trades.

  15. Technology and social process : oscillations in Iron Age copper production and power in Southern Jordan

    E-Print Network [OSTI]

    Ben-Yosef, Erez

    2010-01-01

    Valley (Tell Hammeh) and iron mining at Mugharat al-Wardahpress. Patterns of Iron Age Mining and Iron Age Settlementresearch concerning Iron Age mining and metallurgy in the

  16. Flow rule of dense granular flows down a rough incline

    E-Print Network [OSTI]

    Tamas Borzsonyi; Robert E. Ecke

    2007-07-09

    We present experimental findings on the flow rule for granular flows on a rough inclined plane using various materials including sand and glass beads of various sizes and four types of copper particles with different shapes. We characterize the materials by measuring $h_s$ (the thickness at which the flow subsides) as a function of the plane inclination $\\theta$ on various surfaces. Measuring the surface velocity $u$ of the flow as a function of flow thickness $h$, we find that for sand and glass beads the Pouliquen flow rule $u/\\sqrt{gh} \\sim \\beta h/h_s$ provides reasonable but not perfect collapse of the $u(h)$ curves measured for various $\\theta$ and mean particle diameter $d$. Improved collapse is obtained for sand and glass beads by using a recently proposed scaling of the form $u/\\sqrt{gh} =\\beta \\cdot h \\tan^2\\theta /h_s\\ \\tan^2\\theta_1$ where $\\theta_1$ is the angle at which the $h_s(\\theta)$ curves diverge. Measuring the slope $\\beta$ for ten different sizes of sand and glass beads, we find a systematic, strong increase of $\\beta$ with the divergence angle $\\theta_1$ of $h_s$. The copper materials with different shapes are not well described by either flow rule with $u \\sim h^{3/2}$.

  17. Head-on collisions of dense granular jets

    E-Print Network [OSTI]

    Ellowitz, Jake

    2015-01-01

    When a dense stream of dry, non-cohesive grains hits a fixed target, a collimated sheet is ejected from the impact region, very similar to what happens for a stream of water. In this study, as a continuation of the investigation why such remarkably different incident fluids produce such similar ejecta, we use discrete particle simulations to collide two unequal-width granular jets head-on in two dimensions. In addition to the familiar coherent ejecta, we observe that the impact produces a far less familiar quasi-steady-state corresponding to a uniformly translating free surface and flow field. Upon repeating such impacts with multiple continuum fluid simulations, we show that this translational speed is controlled only by the total energy dissipation rate to the power $1.5$, and is independent of the details of the jet composition. Our findings, together with those from impacts against fixed targets, challenge the principle of scattering in which material composition is inferred from observing the ejecta prod...

  18. Improved granular activated carbon for the stabilization of wastewater PH

    SciTech Connect (OSTI)

    Farmer, R.W.; Dussert, B.W.; Kovacic, S.L. [Calgon Carbon Corp., Pittsburgh, PA (United States)

    1996-12-31

    Laboratory studies have identified the cause of the pH rise, which occurs during water treatment with activated carbon, as an interaction between the naturally occurring anions and protons in the water and the carbon surface. The interaction can be described as an ion exchange type of phenomenon, in which the carbon surface sorbs the anions and corresponding hydronium ions from the water. These studies have shown that the anion sorption and resulting pH increase is independent of the raw material used for the activated carbon production, e.g. bituminous or subbituminous coal, peat, wood or coconut. Also, the pH excursions occur with virgin, reactivated, and acid washed granular carbons. Current pH control technologies focus on adjustment of the wastewater pH prior to discharge or recycle of the initial effluent water until the pH increase abates. However, improved water pH control options have been realized by altering the carbon surface through controlled oxidation rather than the water chemistry or extended preprocessing at the treatment site.

  19. Fluid-driven deformation of a soft granular material

    E-Print Network [OSTI]

    Christopher W. MacMinn; Eric R. Dufresne; John S. Wettlaufer

    2015-02-24

    Compressing a porous, fluid-filled material will drive the interstitial fluid out of the pore space, as when squeezing water out of a kitchen sponge. Inversely, injecting fluid into a porous material can deform the solid structure, as when fracturing a shale for natural gas recovery. These poromechanical interactions play an important role in geological and biological systems across a wide range of scales, from the propagation of magma through the Earth's mantle to the transport of fluid through living cells and tissues. The theory of poroelasticity has been largely successful in modeling poromechanical behavior in relatively simple systems, but this continuum theory is fundamentally limited by our understanding of the pore-scale interactions between the fluid and the solid, and these problems are notoriously difficult to study in a laboratory setting. Here, we present a high-resolution measurement of injection-driven poromechanical deformation in a system with granular microsctructure: We inject fluid into a dense, confined monolayer of soft particles and use particle tracking to reveal the dynamics of the multi-scale deformation field. We find that a continuum model based on poroelasticity theory captures certain macroscopic features of the deformation, but the particle-scale deformation field exhibits dramatic departures from smooth, continuum behavior. We observe particle-scale rearrangement and hysteresis, as well as petal-like mesoscale structures that are connected to material failure through spiral shear banding.

  20. Synthesis of iron based hydrocracking catalysts

    SciTech Connect (OSTI)

    Farcasiu, M.; Eldredge, P.A.; Ladner, E.P.

    1993-05-25

    A method of preparing an iron based hydrocracking catalyst is described, comprising reacting iron (111) oxide powders and elemental sulfur with a liquid hydrogen donor having a hydroaromatic structure present in the range of from about 5 to about 50 times the weight of iron (111) oxide at a temperature in the range of from about 180 C to about 240 C for a time in the range of from about 0 to about 8 hours.

  1. Onset of erosion of a granular bed in a channel driven by fluid flow Anyu Hong, Mingjiang Tao, and Arshad Kudrolli

    E-Print Network [OSTI]

    Kudrolli, Arshad

    Onset of erosion of a granular bed in a channel driven by fluid flow Anyu Hong, Mingjiang Tao); 10.1063/1.4863989 Simulations of granular bed erosion due to laminar shear flow near the critical.1063/1.2213641 Onset of erosion and avalanche for an inclined granular bed sheared by a continuous laminar flow Phys

  2. Frequency-and Amplitude-Dependent Transmission of Stress Waves in Curved One-Dimensional Granular Crystals

    E-Print Network [OSTI]

    Daraio, Chiara

    the stress wave propagation in curved chains of particles (granular crystals) confined by bent elastic guides Crystals Composed of Diatomic Particles Jinkyu Yang & Chiara Daraio Received: 19 January 2012 /Accepted: 25 the granular crystals with small-amplitude, broadband perturbations using a piezoelectric actuator to generate

  3. Static properties of granular In this chapter, we are interested in static pilings of cohesionless grains. For example, we

    E-Print Network [OSTI]

    Claudin, Philippe

    Static properties of granular materials In this chapter, we are interested in static pilings in another language than english, as well as conference proceedings or reviews difficult to access. 1 Statics at the grain scale 1.1 Static solutions Equilibrium conditions Let us consider a single grain in a granular

  4. JOURNAL OF GEOPHYSICAL RESEARCH, VOL. ???, XXXX, DOI:10.1029/, Pore pressure evolution in deforming granular1

    E-Print Network [OSTI]

    Toussaint, Renaud

    JOURNAL OF GEOPHYSICAL RESEARCH, VOL. ???, XXXX, DOI:10.1029/, Pore pressure evolution in deforming. Often deformation of the granular network leads to pore fluid8 pressure (PP) changes. If the PP rises coupling6 between two deforming phases: the solid granular network and the fluid-filled7 pore network

  5. Kinetics of dissolution and bio-availability of iron in amorphous siliceous iron oxides 

    E-Print Network [OSTI]

    Seaman, John C.

    1990-01-01

    KINETICS OF DISSOLUTION AND BIO-AVAILABILITY OF IRON IN AMORPHOUS SILICEOUS IRON OXIDES A Thesis By John C. Seaman Submitted to the Graduate College of Texas AIIM University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE December 1990 Major Subject: Soil Science KINETICS OF DISSOLUTION AND BIO-AVAILABILITY OF IRON IN AMORPHOUS SILICEOUS IRON OXIDES A Thesis By John C. Seaman Approved as to style and content by: Richard H. Loeppert (Chair of Committee...

  6. Method for producing iron-based catalysts

    DOE Patents [OSTI]

    Farcasiu, Malvina (Pittsburgh, PA); Kaufman, Phillip B. (Library, PA); Diehl, J. Rodney (Pittsburgh, PA); Kathrein, Hendrik (McMurray, PA)

    1999-01-01

    A method for preparing an acid catalyst having a long shelf-life is provided comprising doping crystalline iron oxides with lattice-compatible metals and heating the now-doped oxide with halogen compounds at elevated temperatures. The invention also provides for a catalyst comprising an iron oxide particle having a predetermined lattice structure, one or more metal dopants for said iron oxide, said dopants having an ionic radius compatible with said lattice structure; and a halogen bound with the iron and the metal dopants on the surface of the particle.

  7. Iron oxyhydroxide mineralization on microbial extracellular polysaccha...

    Office of Scientific and Technical Information (OSTI)

    a creek and abandoned mine; these samples are dominated by iron oxyhydroxide-coated structures with sheath, stalk, and filament morphologies. In addition, we characterized the...

  8. Nanostructure, Chemistry and Crystallography of Iron Nitride...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Nanostructure, Chemistry and Crystallography of Iron Nitride Magnetic Materials by Ultra-High-Resolution Electron Microscopy and Related Methods Nanostructure, Chemistry and...

  9. Lithium Insertion Chemistry of Some Iron Vanadates

    E-Print Network [OSTI]

    Patoux, Sebastien; Richardson, Thomas J.

    2008-01-01

    in A. Nazri, G.Pistoia (Eds. ), Lithium batteries, Science &structure materials in lithium cells, for a lower limitLithium Insertion Chemistry of Some Iron Vanadates Sébastien

  10. Iron Availability in the Southern Ocean

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Iron Availability in the Southern Ocean Print The Southern Ocean, circling the Earth between Antarctica and the southernmost regions of Africa, South America, and Australia, is...

  11. Rapid granular flows on a rough incline: phase diagram, gas transition, and effects of air drag

    E-Print Network [OSTI]

    Tamas Borzsonyi; Robert E. Ecke

    2006-11-16

    We report experiments on the overall phase diagram of granular flows on an incline with emphasis on high inclination angles where the mean layer velocity approaches the terminal velocity of a single particle free falling in air. The granular flow was characterized by measurements of the surface velocity, the average layer height, and the mean density of the layer as functions of the hopper opening, the plane inclination angle and the downstream distance x of the flow. At high inclination angles the flow does not reach an x-invariant steady state over the length of the inclined plane. For low volume flow rates, a transition was detected between dense and very dilute (gas) flow regimes. We show using a vacuum flow channel that air did not qualitatively change the phase diagram and did not quantitatively modify mean flow velocities of the granular layer except for small changes in the very dilute gas-like phase.

  12. Crucial role of side walls for granular surface flows: consequences for the rheology

    E-Print Network [OSTI]

    Pierre Jop; Yoël Forterre; Olivier Pouliquen

    2014-10-16

    In this paper we study the steady uniform flows that develop when granular material is released from a hopper on top of a static pile in a channel. We more specifically focus on the role of side walls by carrying out experiments in setup of different widths, from narrow channels 20 particle diameters wide to channels 600 particle diameters wide. Results show that steady flows on pile are entirely controlled by side wall effects. A theoretical model, taking into account the wall friction and based on a simple local constitutive law recently proposed for other granular flow configurations (GDR MiDi 2004), gives predictions in quantitative agreement with the measurements. This result gives new insights in our understanding of free surface granular flows and strongly supports the relevance of the constitutive law proposed.

  13. Free cooling and high-energy tails of granular gases with variable restitution coefficient

    E-Print Network [OSTI]

    Ricardo J. Alonso; Bertrand Lods

    2010-05-31

    We prove the so-called generalized Haff's law yielding the optimal algebraic cooling rate of the temperature of a granular gas described by the homogeneous Boltzmann equation for inelastic interactions with non constant restitution coefficient. Our analysis is carried through a careful study of the infinite system of moments of the solution to the Boltzmann equation for granular gases and precise Lp estimates in the selfsimilar variables. In the process, we generalize several results on the Boltzmann collision operator obtained recently for homogeneous granular gases with constant restitution coefficient to a broader class of physical restitution coefficients that depend on the collision impact velocity. This generalization leads to the so-called L1-exponential tails theorem. for this model.

  14. Superdiffusive Transport and Energy Localization in Disordered Granular Crystals

    E-Print Network [OSTI]

    Alejandro J. Martínez; P. G. Kevrekidis; Mason A. Porter

    2015-09-11

    We study the spreading of initially localized excitations in 1D disordered granular crystals. We thereby investigate localization phenomena in strongly nonlinear systems, which we demonstrate to be fundamentally different from localization in linear and weakly nonlinear systems. We compare wave dynamics in chains with 3 different types of disorder: an uncorrelated (Anderson-like) disorder and 2 types of correlated disorders (random dimer arrangements), and for 2 types of initial conditions: displacement excitations and velocity excitations. For strongly precompressed chains, the dynamics depend strongly on the initial condition. For displacement excitations, the long-time behavior of the second moment $\\tilde{m}_2$ has oscillations that depend on the type of disorder, with a complex trend that differs markedly from a power law and which is particularly evident for an Anderson disorder. For velocity excitations, we find a scaling $\\tilde{m}_2\\sim t^{\\gamma}$ (for a constant $\\gamma$) for all 3 types of disorder. For weakly precompressed (strongly nonlinear) chains, $\\tilde{m}_2$ and the inverse participation ratio $P^{-1}$ satisfy $\\tilde{m}_2\\sim t^{\\gamma}$ and $P^{-1}\\sim t^{-\\eta}$, and the dynamics is superdiffusive for all examined cases. When precompression is strong, the IPR decreases slowly for all 3 types of disorder, and we observe a partial localization around the core and the leading edge of the wave. For an Anderson disorder, displacement perturbations lead to localization of energy primarily in the core, and velocity perturbations cause the energy to be divided between the core and the leading edge. This localization phenomenon does not occur in the sonic-vacuum regime, which yields the surprising result that the energy is no longer contained in strongly nonlinear waves but instead is spread across many sites. In this regime, the exponents are very similar in all cases.

  15. Iron Cycling and Redox Evolution in the Precambrian

    E-Print Network [OSTI]

    Planavsky, Noah John

    2012-01-01

    J.C.G. , 1984. Suboxic Diagenesis in Banded Iron Formations.J.C.G. , 1984. Suboxic Diagenesis in Banded Iron Formations.J.C.G. , 1984. Suboxic diagenesis in banded iron formations.

  16. Iron and Steel (2010 MECS) | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Iron and Steel (2010 MECS) Iron and Steel (2010 MECS) Manufacturing Energy and Carbon Footprint for Iron and Steel Sector (NAICS 3311, 3312) Energy use data source: 2010 EIA MECS...

  17. Microbial reduction of iron ore (Patent) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    reducing the ferric iron of the iron ore to ferrous iron, and a substrate operable as an energy source for the microbial reduction; and maintaining the aqueous mixture for a...

  18. Maternal and Infant Iron Status and First Year Illness

    E-Print Network [OSTI]

    Douglas, Sarah E.

    2011-04-20

    Abstract The primary research aims were to understand the relationship between maternal postpartum body iron and birth and 4-month infant body iron and to determine if maternal or newborn iron status was a predictor of first year illness. Subjects...

  19. The production of iron carbide

    SciTech Connect (OSTI)

    Anderson, K.M.; Scheel, J. [Nucor Iron Carbide, Inc., Point Lisas (Trinidad and Tobago)

    1997-12-31

    From start-up in 1994 to present, Nucor`s Iron Carbide plant has overcome many obstacles in achieving design production. Many of these impediments were due to flaws in equipment design. With the integration existing within the plant, limitations in any one system reduced the operating capacity of others. For this reason, as modifications were made and system capacities were increased, the need for additional modifications became apparent. Subsequently, operating practices, maintenance scheduling, employee incentives, and production objectives were continually adapted. This paper discusses equipment and design corrections and the quality issues that contributed to achieving the plant`s production capacity.

  20. Under consideration for publication in J. Fluid Mech. 1 Erosion of a granular bed driven

    E-Print Network [OSTI]

    Kudrolli, Arshad

    relating some #12;Bed Erosion by Laminar Flow 3 measure of the fluid forcing at the onset of granular flowUnder consideration for publication in J. Fluid Mech. 1 Erosion of a granular bed driven by laminar fluid flow By A L E X A N D E R E. L O B K O V S K Y1, A S H I S H V. O R P E2, R Y A N M O L L O Y2

  1. Low-field diamagnetic response of granular superconductors at finite temperatures

    SciTech Connect (OSTI)

    Auletta, C.; Raiconi, G. ); De Luca, R.; Pace, S. )

    1994-05-01

    We study the low-field diamagnetic response of granular superconductors at finite temperatures by means of a simple two-dimensional Josephson-junction array. The temperature effects are taken into account by inserting white-noise current sources in parallel to the resistively shunted junction circuit models of the Josephson junctions of the network. By this analysis we argue that a simplified one-dimensional description of the equivalent circuit, proposed by the authors for cylindrical granular superconductors, is still valid even in the presence of thermally activated flux jumps. A flux-creep picture for intergranular flux motion follows.

  2. Force distribution in granular media studied by an energy method based on statistical mechanics

    E-Print Network [OSTI]

    S. A. Galindo-Torres

    2010-03-31

    In the present letter a method to find a proper expression for the force distribution inside a granular sample in static equilibrium is proposed. The method is based in statistical mechanics and the force distribution is obtained by studying how the potential elastic energy is divided among the different contacts between grains. It is found with DEM simulations with spheres that the elastic potential energy distribution follows a Bose Einstein law from which the force distribution is deduced. The present letter open a way in which granular materials can be studied with the tools provided by statistical mechanics.

  3. Dechlorination of TCE with palladized iron

    DOE Patents [OSTI]

    Fernando, Quintus (Tucson, AZ); Muftikian, Rosy (Tucson, AZ); Korte, Nic (Grand Junction, CO)

    1997-01-01

    The present invention relates to various methods, such as an above-ground method and an in-ground method, of using a palladized iron bimetallic system for the dechlorination of chlorinated organic compounds from various effluents or contaminated soil containing the same. The use of palladized iron bimetallic system results in the dechlorination of the chlorinated organic compound into environmentally safe reaction products.

  4. ANEMIA OF DISORDERED IRON METABOLISM AND HEME

    E-Print Network [OSTI]

    decreased Transferrin Receptor increased Bone Marrow decreased M:E ratio THERAPY Treatment of Cause Fatigue Arthralgia Infertility and Impotence Cardiac Disease Diabetes Cirrhosis Hyperpigmented Skin LABORATORY Increased Iron Saturation Increased Ferritin #12;9/16/2013 9 TREATMENT Phlebotomy Iron

  5. Iron is the Key to Preserving Dinosaur Soft Tissue

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    for this unexpected preservation-iron nanoparticles associated with dinosaur blood vessels were identified at the ALS. Researchers hypothesized that the iron had come from...

  6. Manufacturing Energy and Carbon Footprint - Sector: Iron and...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Steel (NAICS 3311, 3312), October 2012 (MECS 2006) steelfootprint2012.pdf More Documents & Publications MECS 2006 - Iron and Steel Iron and Steel (2010 MECS) MECS 2006 - Cement...

  7. Phase Discrimination through Oxidant Selection for Iron Oxide...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Phase Discrimination through Oxidant Selection for Iron Oxide Ultrathin Films Home > Research > ANSER Research Highlights > Phase Discrimination through Oxidant Selection for Iron...

  8. Next Generation Metallic Iron Nodule Technology in Electric Furnace...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Next Generation Metallic Iron Nodule Technology in Electric Furnace Steelmaking Next Generation Metallic Iron Nodule Technology in Electric Furnace Steelmaking This factsheet...

  9. Preparations of rare earth-iron alloys by thermite reduction

    DOE Patents [OSTI]

    Schmidt, Frederick A. (Ames, IA); Peterson, David T. (Ames, IA); Wheelock, John T. (Nevada, IA)

    1986-09-16

    An improved method for the preparation of high-purity rare earth-iron alloys by the aluminothermic reduction of a mixture of rare earth and iron fluorides.

  10. Iron Cycling and Redox Evolution in the Precambrian

    E-Print Network [OSTI]

    Planavsky, Noah John

    2012-01-01

    aqueous ferrous iron and goethite. Earth and PlanetaryAdsorption of Phosphate on Goethite in Marine Electrolytes.aqueous ferrous iron and goethite and found an equilibrium

  11. Iron is the Key to Preserving Dinosaur Soft Tissue

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the iron associated with fossil tissues, which occurred primarily as the mineral goethite. They then employed experiments to show that iron, derived from hemoglobin lysate,...

  12. Neutron scattering of iron-based superconductors (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    Neutron scattering of iron-based superconductors Citation Details In-Document Search Title: Neutron scattering of iron-based superconductors Low-energy spin excitations have been...

  13. Incremental stress and microstructural response of granular soils under undrained axisymmetric deformation

    E-Print Network [OSTI]

    Luding, Stefan

    Incremental stress and microstructural response of granular soils under undrained axisymmetric deformation N. Kumar, S. Luding & V. Magnanimo MultiScale Mechanics, CTW, MESA+ University of Twente, Enschede different deformation paths (history) affect the actual mechanical state of the system. Here, we study

  14. Hydrodynamics and transport coefficients for dilute granular gases Nikolai Brilliantov1,2

    E-Print Network [OSTI]

    of engineering and soil mechanics e.g., Refs. 1,2 a first-principles theory for dense granular media is still observa- tions e.g., Refs. 14­16 nor with basic mechanics of par- ticle collisions 17 . The coefficient

  15. Observation of Two-Wave Structure in Strongly Nonlinear Dissipative Granular Chains Alexandre Rosas

    E-Print Network [OSTI]

    Lindenberg, Katja

    model under consideration here is perhaps the simplest example of a strongly nonlinear discrete system available for ex- perimental verification. It is a chain of granules that inter- acts via a power law system. While we only dem- onstrate this phenomenon in a one-dimensional granular chain, this new

  16. Gas-Mediated Impact Dynamics in Fine-Grained Granular Materials John R. Royer,1

    E-Print Network [OSTI]

    Jaeger, Heinrich M.

    , The University of Chicago, Chicago, Illinois 60637, USA 2 Consortium for Advanced Radiation Sources as it moves through the granular me- dium. Various competing force laws have been proposed, based on scaling laws relating the penetration depth to the impact energy or momentum [5,6], or on direct measure- ment

  17. Energy Decay in Three-Dimensional Freely Cooling Granular Gas Sudhir N. Pathak,1,*

    E-Print Network [OSTI]

    Ravindran, Rajesh

    -600113, India 2 Department of Physics, University of Michigan, Ann Arbor, Michigan 48109-1040, USA 3 Department of Physics, Indian Institute of Technology, Bombay, Powai, Mumbai-400076, India (Received 2, the cluster statistics and velocity distribution differ from it. Thus, the freely cooling granular gas fits

  18. Model of coarsening and vortex formation in vibrated granular rods Igor S. Aranson

    E-Print Network [OSTI]

    Tsimring, Lev S.

    Model of coarsening and vortex formation in vibrated granular rods Igor S. Aranson Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 Lev S. Tsimring Institute for Nonlinear Science spontaneous formation of the long-range orientational order and large- scale vortices in a system of vibrated

  19. Continuum description of avalanches in granular media Igor S. Aranson1

    E-Print Network [OSTI]

    Tsimring, Lev S.

    '' phases is more subtle and itself is controlled by the dynamics. In this Rapid Communication we propose from the Landau theory of phase transitions 16 . We assume that the shear stresses in a partially ordinary matter, the phase transition in granular matter is controlled not by the temperature

  20. Analysis of granular flow in a pebble-bed nuclear reactor Chris H. Rycroft,1

    E-Print Network [OSTI]

    Bazant, Martin Z.

    Analysis of granular flow in a pebble-bed nuclear reactor Chris H. Rycroft,1 Gary S. Grest,2 James February 2006; published 24 August 2006 Pebble-bed nuclear reactor technology, which is currently being States, the Modular Pebble Bed Reactor MPBR 4,8 is a candidate for the next generation nuclear plant

  1. 4/3 law of Granular Particles Flowing through a Vertical Pipe

    E-Print Network [OSTI]

    Hayakawa, Hisao

    excitations under vertical vibration [5,6] and a fluidized bed due to air injected inside a box containing dimensional realiza­ tion of a fluidized bed is also a typical example of unusual features of granular motion behaviors [1], such as convection [2], size segregation [3], bubbling [4], standing waves and localized

  2. Experiments using non-intrusive particle tracing techniques for granular chute flows. Final report

    SciTech Connect (OSTI)

    Rosato, A.D.; Dave, R.N.; Fischer, I.S.

    1998-12-31

    The objective of this contract was to develop a system capable of non-intrusively tracking the motion of an individual particle for the study of granular flows down inclined chutes. The result of the project is a system capable of following the three-dimensional translational and rotational motion of an individual particle embedded with a flowing granular material. The basic system consists of a sphere embedded with three orthogonal transmitters emitting at different frequencies which induce voltages in an antenna array surrounding the flow regime. Analysis of the induced voltage signals within the framework of a derived model yields both the position and orientation of the sphere. Tests were performed in a small scale model chute as well as in a cylindrical vibrated granular bed, which clearly demonstrates the capability of the system. As a result of discussions at meetings held semi-annually for the Granular Flow Advanced Research Objectives (GFARO) contractors, it was deemed necessary to pursue an additional experimental program as part of this contract related to the measurement of sphere collision properties. The outcome of the work (reported in Appendix C) is the determination of certain properties which are needed for use in computer simulations and theory.

  3. An accurate elasto-plastic frictional tangential forcedisplacement model for granular-flow

    E-Print Network [OSTI]

    Vu-Quoc, Loc

    An accurate elasto-plastic frictional tangential force­displacement model for granular for both elastic and plastic deformations together with interfacial friction occurring in collisions of spherical particles. This elasto-plastic frictional TFD model, with its force-driven version presented in [L

  4. Close-Packed Floating Clusters: Granular Hydrodynamics Beyond the Freezing Point? Baruch Meerson,1

    E-Print Network [OSTI]

    Meerson, Baruch

    Close-Packed Floating Clusters: Granular Hydrodynamics Beyond the Freezing Point? Baruch Meerson,1 a simple explanation for the success of NSGH beyond the freezing point. DOI: 10.1103/PhysRevLett.91 the packing fraction approaches the freezing point value f ' 0:49 (in three dimensions) or 0.69 (in two

  5. Collapse dynamics and runout of dense granular materials in a fluid V. Topina,b

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    [3]. The dis- persion of fuel fragments in the coolant water during a hypothetic nuclear accidentCollapse dynamics and runout of dense granular materials in a fluid V. Topina,b , Y. Moneriea,b , F. (Dated: April 16, 2012) We investigate the effect of an ambient fluid on the dynamics of collapse

  6. Static and flowing regions in granular collapses down channels: Insights from a sedimenting shallow water model

    E-Print Network [OSTI]

    Huppert, Herbert

    Static and flowing regions in granular collapses down channels: Insights from a sedimenting shallow extend the model of Larrieu 2006 to include an estimation for the interface between the static, 043301 2007 . An empirical sedimentation term Ls and the instantaneous removal of a static deposit wedge

  7. A General Criterion for Liquefaction in Granular Layers with Heterogeneous Pore Pressure

    E-Print Network [OSTI]

    Einat, Aharonov

    A General Criterion for Liquefaction in Granular Layers with Heterogeneous Pore Pressure Liran that liquefaction oc- curs when the pore pressure within the layer becomes equal to the applied normal stress pressure is spatially heterogeneous and it is not clear what measurement of pore pressure should be used

  8. Dynamic fracture of granular material under quasi-static loading Amir Sagy,1,2

    E-Print Network [OSTI]

    Fineberg, Jay

    Dynamic fracture of granular material under quasi-static loading Amir Sagy,1,2 Gil Cohen,3 Ze; published 13 April 2006. [1] The dynamics of rapid fracturing of heterogeneous grainy media are studied in laboratory experiments in which artificial rock slabs are fractured under uniaxial tension. By performing

  9. Stress and fabric for polydisperse, frictionless, dense 2D granular media , S. M. Peyghoon

    E-Print Network [OSTI]

    Luding, Stefan

    Stress and fabric for polydisperse, frictionless, dense 2D granular media M. Madadi , S. M For fabric and stress tensor, correlations of microscopic quantities are studied and the influence show that fabric and stress can be factorized into products of some averaged quantities (like

  10. Shock-Wave Attenuation and Energy-Dissipation Potential of Granular Materials

    E-Print Network [OSTI]

    Grujicic, Mica

    Shock-Wave Attenuation and Energy-Dissipation Potential of Granular Materials Mica Grujicic, B this approach, both compression shocks and decompression waves are treated as (stress, specific volume, particle velocity, mass-based internal energy density, temperature, and mass-based entropy density) propagating

  11. Numerical simulation of comminution in granular materials with an application to fault gouge evolution 

    E-Print Network [OSTI]

    Lang, Richard Anthony

    2004-09-30

    of comminution in a sheared granular material. The model, based on the Discrete Element Method, simulates a layer of 2-D circular grains subjected to normal stress and sheared at constant velocity. An existing code was modified to allow grains to break when...

  12. Numerical tests of constitutive laws for dense granular flows Gregg Lois,1

    E-Print Network [OSTI]

    Carlson, Jean

    theories of plasticity, these ap- proaches were restricted to quasistatic deformation and in- cipient physics and thermodynamics 12,13 . The first theories of granular materials were motivated primarily with the develop- ment of kinetic theory 17­29 . But kinetic theory is based on the assumption that interactions

  13. A Continuum DamageBreakage Faulting Model and Solid-Granular Transitions VLADIMIR LYAKHOVSKY

    E-Print Network [OSTI]

    Lyakhovsky, Vladimir

    and YEHUDA BEN-ZION 2 Abstract--We present a thermodynamically-based formulation for mechanical modeling of a granular phase in a failure slip zone with a breakage parameter. The stress­strain relation and kinetics models. Shear heating during deformation can lead to a secondary finite-width internal localization

  14. Synthesis of iron based hydrocracking catalysts

    DOE Patents [OSTI]

    Farcasiu, Malvina (Pittsburgh, PA); Eldredge, Patricia A. (Barboursville, VA); Ladner, Edward P. (Pittsburgh, PA)

    1993-01-01

    A method of preparing a fine particle iron based hydrocracking catalyst and the catalyst prepared thereby. An iron (III) oxide powder and elemental sulfur are reacted with a liquid hydrogen donor having a hydroaromatic structure present in the range of from about 5 to about 50 times the weight of iron (III) oxide at a temperature in the range of from about 180.degree. C. to about 240.degree. C. for a time in the range of from about 0 to about 8 hours. Various specific hydrogen donors are disclosed. The catalysts are active at low temperature (<350.degree. C.) and low pressure.

  15. Dechlorination of TCE with palladized iron

    DOE Patents [OSTI]

    Fernando, Quintus (Tucson, AZ); Muftikian, Rosy (Tucson, AZ); Korte, Nic (Grand Junction, CO)

    1998-01-01

    The present invention relates to various methods, such as an above-ground method and an in-ground method, of using a palladized iron bimetallic system for the dechlorination of chlorinated organic compounds from effluents containing the same. The use of palladized iron bimetallic system results in the dechlorination of the chlorinated organic compound into environmentally safe reaction products. The present invention also provides kits, devices, and other instruments that use the above-mentioned palladized iron bimetallic system for the dechlorination of chlorinated organic compounds.

  16. Dechlorination of TCE with palladized iron

    DOE Patents [OSTI]

    Fernando, Quintus (Tucson, AZ); Muftikian, Rosy (Tucson, AZ); Korte, Nic (Grand Junction, CO)

    1997-01-01

    The present invention relates to various methods, such as an above-ground method and an in-ground method, of using a palladized iron bimetallic system for the dechlorination of chlorinated organic compounds from effluents containing the same. The use of palladized iron bimetallic system results in the dechlorination of the chlorinated organic compound into environmentally safe reaction products. The present invention also provides kits, devices, and other instruments that use the above-mentioned palladized iron bimetallic system for the dechlorination of chlorinated organic compounds.

  17. Dechlorination of TCE with palladized iron

    DOE Patents [OSTI]

    Fernando, Q.; Muftikian, R.; Korte, N.

    1997-03-18

    The present invention relates to various methods, such as an above-ground method and an in-ground method, of using a palladized iron bimetallic system for the dechlorination of chlorinated organic compounds from effluents containing the same. The use of palladized iron bimetallic system results in the dechlorination of the chlorinated organic compound into environmentally safe reaction products. The present invention also provides kits, devices, and other instruments that use the above-mentioned palladized iron bimetallic system for the dechlorination of chlorinated organic compounds. 10 figs.

  18. Dechlorination of TCE with palladized iron

    DOE Patents [OSTI]

    Fernando, Q.; Muftikian, R.; Korte, N.

    1998-06-02

    The present invention relates to various methods, such as an above-ground method and an in-ground method, of using a palladized iron bimetallic system for the dechlorination of chlorinated organic compounds from effluents containing the same. The use of palladized iron bimetallic system results in the dechlorination of the chlorinated organic compound into environmentally safe reaction products. The present invention also provides kits, devices, and other instruments that use the above-mentioned palladized iron bimetallic system for the dechlorination of chlorinated organic compounds. 10 figs.

  19. Complement receptor type 2conjugated superparamagnetic iron oxide nanoparticles

    E-Print Network [OSTI]

    Levin, Judith G.

    ). Cross-linked iron oxide (CLIO) and other iron oxide formulations affect T2 primarily and lead+), accelerate T1 relaxation and lead to brighter contrast images. The superparamagnetic iron oxide (SPIOComplement receptor type 2­conjugated superparamagnetic iron oxide nanoparticles [CR2-Fc-SPIO] Kam

  20. Iron and the ecology of marine microbes

    E-Print Network [OSTI]

    Ventouras, Laure-Anne

    2013-01-01

    Iron is a cofactor of a number biochemical reactions that are essential for life. In the marine environment, this micronutrient is a scarce resource that limits processes of global importance such as photosynthesis and ...

  1. Elastic moduli of nickel and iron aluminides 

    E-Print Network [OSTI]

    Manjigani, Sreedhar

    1993-01-01

    A research program has been completed on the dynamic elastic modulus measurements for several nickel and iron aluminide based intermetallics. The PUCOT (piezoelectric ultrasonic composite oscillator technique) was used for this purpose. Stress...

  2. System and method for producing metallic iron

    DOE Patents [OSTI]

    Englund, David J.; Schlichting, Mark; Meehan, John; Crouch, Jeremiah; Wilson, Logan

    2014-07-29

    A method of production of metallic iron nodules comprises assembling a hearth furnace having a moveable hearth comprising refractory material and having a conversion zone and a fusion zone, providing a hearth material layer comprising carbonaceous material on the refractory material, providing a layer of reducible material comprising and iron bearing material arranged in discrete portions over at least a portion of the hearth material layer, delivering oxygen gas into the hearth furnace to a ratio of at least 0.8:1 ponds of oxygen to pounds of iron in the reducible material to heat the conversion zone to a temperature sufficient to at least partially reduce the reducible material and to heat the fusion zone to a temperature sufficient to at least partially reduce the reducible material, and heating the reducible material to form one or more metallic iron nodules and slag.

  3. Mach cone in a shallow granular fluid Patrick Heil, E. C. Rericha # , Daniel I. Goldman, and Harry L. Swinney +

    E-Print Network [OSTI]

    ]. For example, measurements on the Von Kâ??armâ??an vortex street of flow past a cylinder, the drag force reduc is inserted into a shallow, vibrofluidized granular layer consisting of bronze spheres with a diameter d = 0

  4. Dechlorination of TCE with palladized iron

    DOE Patents [OSTI]

    Fernando, Q.; Muftikian, R.; Korte, N.

    1997-04-01

    The present invention relates to various methods, such as an above-ground method and an in-ground method, of using a palladized iron bimetallic system for the dechlorination of chlorinated organic compounds from various effluents or contaminated soil containing the same. The use of palladized iron bimetallic system results in the dechlorination of the chlorinated organic compound into environmentally safe reaction products. 10 figs.

  5. Iron availability limits the ocean nitrogen inventory stabilizing feedbacks between marine denitrification and nitrogen fixation

    E-Print Network [OSTI]

    Moore, J. Keith; Doney, Scott C

    2007-01-01

    Falkowski (2001), Iron availability, cellular iron quotas,C. Doney (2007), Iron availability limits the ocean nitrogentemperature, P and Fe availability. Diazotrophs have higher

  6. Understanding the Factors Affecting the Formation of Carbonyl Iron Electrodes in Rechargeable Alkaline Iron Batteries

    SciTech Connect (OSTI)

    Manohar, AK; Yang, CG; Malkhandi, S; Yang, B; Prakash, GKS; Narayanan, SR

    2012-01-01

    Rechargeable iron-based alkaline batteries such as iron - air and nickel - iron batteries are attractive for large-scale electrical energy storage because iron is inexpensive, globally-abundant and environmentally-friendly. Further, the iron electrode is known for its robustness to repeated charge/discharge cycling. During manufacturing these batteries are charged and discharged 20 to 50 times during which the discharge capacity of the iron electrode increases gradually and attains a stable value. This process of achieving stable capacity is called formation. In this study we have focused our efforts on understanding the effect of electrode design on formation. We have investigated the role of wetting agent, pore-former additive, and sulfide additive on the formation of carbonyl iron electrodes. The wetting agent increased the rate of formation while the pore-former additive increased the final capacity. Sodium sulfide added to the electrolyte worked as a de-passivation agent and increased the final discharge capacity. We have proposed a phenomenological model for the formation process that predicts the rate of formation and final discharge capacity given the design parameters for the electrode. The understanding gained here will be useful in reducing the time lost in formation and in maximizing the utilization of the iron electrode. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.021301jes] All rights reserved.

  7. Acoustically-induced slip in sheared granular layers: application to dynamic earthquake triggering

    E-Print Network [OSTI]

    Ferdowsi, Behrooz; Guyer, Robert A; Johnson, Paul A; Marone, Chris; Carmeliet, Jan

    2015-01-01

    A fundamental mystery in earthquake physics is "how can an earthquake be triggered by distant seismic sources?" A possible explanation is suggested by results found in discrete element method simulations of a granular layer, during stick-slip, that is subject to transient vibrational excitation. We find that at a critical vibrational amplitude (strain) there is an abrupt transition from negligible time-advanced slip (clock advance) to full clock advance, i.e., transient vibration and earthquake are simultaneous. The critical strain is of order 10^{-6}, similar to observations in the laboratory and in Earth. The transition is related to frictional weakening of the granular layer due to a dramatic increase in the number of slipping contacts and decrease in the coordination number. Associated with this frictional weakening is a pronounced decrease in the elastic moduli of the layer.

  8. Mechanical properties of granular materials: A variational approach to grain-scale simulations

    SciTech Connect (OSTI)

    Holtzman, R.; Silin, D.B.; Patzek, T.W.

    2009-01-15

    The mechanical properties of cohesionless granular materials are evaluated from grain-scale simulations. A three-dimensional pack of spherical grains is loaded by incremental displacements of its boundaries. The deformation is described as a sequence of equilibrium configurations. Each configuration is characterized by a minimum of the total potential energy. This minimum is computed using a modification of the conjugate gradient algorithm. Our simulations capture the nonlinear, path-dependent behavior of granular materials observed in experiments. Micromechanical analysis provides valuable insight into phenomena such as hysteresis, strain hardening and stress-induced anisotropy. Estimates of the effective bulk modulus, obtained with no adjustment of material parameters, are in agreement with published experimental data. The model is applied to evaluate the effects of hydrate dissociation in marine sediments. Weakening of the sediment is quantified as a reduction in the effective elastic moduli.

  9. A General Criterion for Liquefaction in Granular Layers with Heterogeneous Pore Pressure

    E-Print Network [OSTI]

    Goren, Liran; Aharonov, Einat; Sparks, David; Flekkøy, Eirik Grude

    2013-01-01

    Fluid-saturated granular and porous layers can undergo liquefaction and lose their shear resistance when subjected to shear forcing. In geosystems, such a process can lead to severe natural hazards of soil liquefaction, accelerating slope failure, and large earthquakes. Terzaghi's principle of effective stress predicts that liquefaction occurs when the pore pressure within the layer becomes equal to the applied normal stress on the layer. However, under dynamic loading and when the internal permeability is relatively small the pore pressure is spatially heterogeneous and it is not clear what measurement of pore pressure should be used in Terzaghi's principle. Here, we show theoretically and demonstrate using numerical simulations a general criterion for liquefaction that applies also for the cases in which the pore pressure is spatially heterogeneous. The general criterion demands that the average pore pressure along a continuous surface within the fluid-saturated granular or porous layer is equal to the appl...

  10. A General Criterion for Liquefaction in Granular Layers with Heterogeneous Pore Pressure

    E-Print Network [OSTI]

    Liran Goren; Renaud Toussaint; Einat Aharonov; David Sparks; Eirik Grude Flekkøy

    2013-12-22

    Fluid-saturated granular and porous layers can undergo liquefaction and lose their shear resistance when subjected to shear forcing. In geosystems, such a process can lead to severe natural hazards of soil liquefaction, accelerating slope failure, and large earthquakes. Terzaghi's principle of effective stress predicts that liquefaction occurs when the pore pressure within the layer becomes equal to the applied normal stress on the layer. However, under dynamic loading and when the internal permeability is relatively small the pore pressure is spatially heterogeneous and it is not clear what measurement of pore pressure should be used in Terzaghi's principle. Here, we show theoretically and demonstrate using numerical simulations a general criterion for liquefaction that applies also for the cases in which the pore pressure is spatially heterogeneous. The general criterion demands that the average pore pressure along a continuous surface within the fluid-saturated granular or porous layer is equal to the applied normal stress.

  11. Earthquake behaviour and large-event predictability in a sheared granular stick-slip system

    E-Print Network [OSTI]

    Dalton, F; Dalton, Fergal; Corcoran, David

    2002-01-01

    We present results from a physical experiment which demonstrates that a sheared granular medium behaves in a manner analogous to earthquake activity. The device consists of an annular plate rotating over a granular medium in a stick-slip fashion. Previous observations by us include a bounded critical state with a power law distribution of event energy consistent with the Gutenberg-Richter law, here we also reveal stair-case seismicity, clustering, foreshocks, aftershocks and seismic quiescence. Subcritical and supercritical regimes have also been observed by us depending on the system configuration. We investigate the predictability of large events. Using the quiescence between `shock' events as an alarm condition, it is found that large events are respectively unpredictable, marginally predictable and highly predictable in the subcritical, critical and supercritical states.

  12. Earthquake behaviour and large-event predictability in a sheared granular stick-slip system

    E-Print Network [OSTI]

    Fergal Dalton; David Corcoran

    2002-11-13

    We present results from a physical experiment which demonstrates that a sheared granular medium behaves in a manner analogous to earthquake activity. The device consists of an annular plate rotating over a granular medium in a stick-slip fashion. Previous observations by us include a bounded critical state with a power law distribution of event energy consistent with the Gutenberg-Richter law, here we also reveal stair-case seismicity, clustering, foreshocks, aftershocks and seismic quiescence. Subcritical and supercritical regimes have also been observed by us depending on the system configuration. We investigate the predictability of large events. Using the quiescence between `shock' events as an alarm condition, it is found that large events are respectively unpredictable, marginally predictable and highly predictable in the subcritical, critical and supercritical states.

  13. IEA Energy conservation in the iron and steel industry. [US and Western Europe

    SciTech Connect (OSTI)

    Tunnah, B.G.

    1981-01-01

    The NATO Committee on the Challenges of Modern Society research program, under the auspices of the IEA, had the objectives of collecting data on material requirements and energy-consumption patterns in selected energy-intensive industries in the US and Western Europe, of identifying technologies and operating practices with the potential for energy conservation in those industries, and of recommending research projects that could lead to improved energy efficiency. The steel industry was selected for analysis and ideas for an international cooperative program were developed. Representatives from various countries conducted meetings and the form of an implementing agreement for a research and development program was finalized in December, 1980. The program includes three technical areas: hot-surface inspection, heat recovery, and coal gasification. Hot-surface inspection methods to be demonstrated are: optical, induction, electromagnetic ultrasonic, electromagnetic ultrasonic surface testing methods, and eddy current method for hot surface inspection and an infrared system (possibly). Three heat-recovery projects are: ceramic heat wheel development; demonstration of granular bed/heat pipe system for heat recovery; and demonstration of tubular ceramic recuperators. Processes in coal gasification are: converter process, gas treatment, and iron treatment. Each project is described in detail. (MCW)

  14. Hydrodynamics on non-commutative space --A step toward hydrodynamics of granular materials--

    E-Print Network [OSTI]

    Mayumi Saitou; Kazuharu Bamba; Akio Sugamoto

    2014-09-16

    Hydrodynamics on non-commutative space is studied based on a formulation of hydrodynamics by Y. Nambu in terms of Poisson and Nambu brackets. Replacing these brackets by Moyal brackets with a parameter $\\theta$, a new hydrodynamics on non-commutative space is derived. It may be a step toward to find the hydrodynamics of granular materials whose minimum volume is given by $\\theta$. To clarify this minimum volume, path integral quantization and uncertainty relation of Nambu dynamics are examined.

  15. Angular velocity distribution of a granular planar rotator in a thermalized bath

    E-Print Network [OSTI]

    J. Piasecki; J. Talbot; P. Viot

    2006-10-04

    The kinetics of a granular planar rotator with a fixed center undergoing inelastic collisions with bath particles is analyzed both numerically and analytically by means of the Boltzmann equation. The angular velocity distribution evolves from quasi-gaussian in the Brownian limit to an algebraic decay in the limit of an infinitely light particle. In addition, we compare this model with a planar rotator with a free center. We propose experimental tests that might confirm the predicted behaviors.

  16. DETECTION OF SMALL-SCALE GRANULAR STRUCTURES IN THE QUIET SUN WITH THE NEW SOLAR TELESCOPE

    SciTech Connect (OSTI)

    Abramenko, V. I.; Yurchyshyn, V. B.; Goode, P. R.; Kitiashvili, I. N.; Kosovichev, A. G.

    2012-09-10

    Results of a statistical analysis of solar granulation are presented. A data set of 36 images of a quiet-Sun area on the solar disk center was used. The data were obtained with the 1.6 m clear aperture New Solar Telescope at Big Bear Solar Observatory and with a broadband filter centered at the TiO (705.7 nm) spectral line. The very high spatial resolution of the data (diffraction limit of 77 km and pixel scale of 0.''0375) augmented by the very high image contrast (15.5% {+-} 0.6%) allowed us to detect for the first time a distinct subpopulation of mini-granular structures. These structures are dominant on spatial scales below 600 km. Their size is distributed as a power law with an index of -1.8 (which is close to the Kolmogorov's -5/3 law) and no predominant scale. The regular granules display a Gaussian (normal) size distribution with a mean diameter of 1050 km. Mini-granular structures contribute significantly to the total granular area. They are predominantly confined to the wide dark lanes between regular granules and often form chains and clusters, but different from magnetic bright points. A multi-fractality test reveals that the structures smaller than 600 km represent a multi-fractal, whereas on larger scales the granulation pattern shows no multi-fractality and can be considered as a Gaussian random field. The origin, properties, and role of the population of mini-granular structures in the solar magnetoconvection are yet to be explored.

  17. Solitary waves and conservation laws for highly nonlinear wave equations modeling granular chains

    E-Print Network [OSTI]

    Michelle Przedborski; Stephen C. Anco

    2015-07-16

    An exact solitary wave solution is derived for two nonlinear wave equations. These equations model the long wavelength behavior of compression waves in one-dimensional homogeneous granular chains having weak and strong initial pre-compression. The derivation utilizes conservation laws for energy, momentum, and net displacement speed, which are found through a direct method without using Noether's theorem. Properties of the solitary wave solution, including its width and height, are examined.

  18. Rheology of weakly wetted granular materials - a comparison of experimental and numerical data

    E-Print Network [OSTI]

    Ruediger Schwarze; Anton Gladkyy; Fabian Uhlig; Stefan Luding

    2014-09-12

    Shear cell simulations and experiments of weakly wetted particles (a few volume percent liquid binders) are compared, with the goal to understand their flow rheology. Application examples are cores for metal casting by core shooting made of sand and liquid binding materials. The experiments are carried out with a Couette-like rotating viscometer. The weakly wetted granular materials are made of quartz sand and small amounts of Newtonian liquids. For comparison, experiments on dry sand are also performed with a modified configuration of the viscometer. The numerical model involves spherical, monodisperse particles with contact forces and a simple liquid bridge model for individual capillary bridges between two particles. Different liquid content and properties lead to different flow rheology when measuring the shear stress-strain relations. In the experiments of the weakly wetted granular material, the apparent shear viscosity $\\eta_g$ scales inversely proportional to the inertial number $I$, for all shear rates. On the contrary, in the dry case, an intermediate scaling regime inversely quadratic in $I$ is observed for moderate shear rates. In the simulations, both scaling regimes are found for dry and wet granular material as well.

  19. Granular mixtures modeled as elastic hard spheres subject to a drag force

    E-Print Network [OSTI]

    Francisco Vega Reyes; Vicente Garzo; Andres Santos

    2007-04-24

    Granular gaseous mixtures under rapid flow conditions are usually modeled by a multicomponent system of smooth inelastic hard spheres with constant coefficients of normal restitution. In the low density regime an adequate framework is provided by the set of coupled inelastic Boltzmann equations. Due to the intricacy of the inelastic Boltzmann collision operator, in this paper we propose a simpler model of elastic hard spheres subject to the action of an effective drag force, which mimics the effect of dissipation present in the original granular gas. The Navier--Stokes transport coefficients for a binary mixture are obtained from the model by application of the Chapman--Enskog method. The three coefficients associated with the mass flux are the same as those obtained from the inelastic Boltzmann equation, while the remaining four transport coefficients show a general good agreement, especially in the case of the thermal conductivity. Finally, the approximate decomposition of the inelastic Boltzmann collision operator is exploited to construct a model kinetic equation for granular mixtures as a direct extension of a known kinetic model for elastic collisions.

  20. Moving granular-bed filter development program topical report. Base contract test plan

    SciTech Connect (OSTI)

    Newby, R.A.; Dilmore, W.J.; Fellers, A.W.; Gasparovic, A.C.; Kittle, W.F.; Lippert, T.E.; Smeltzer, E.E.; Yang, W.C.

    1991-10-17

    The Westinghouse Science & Technology Center has proposed a novel moving granular-bed filter concept, the Standleg Moving Granular-Bed Filter (S-MGBF) system, that overcomes the inherent deficiencies of the current state-of-the-art moving granular-bed filter technology. The S-MGBF system combines two unique features that make it highly effective for use in advanced coal-fueled power plants. First, the S-MGBF system applies pelletization technology to generate filter pellets from the power plant solid waste materials, and uses these pellets as a ``once-through`` filtering media to eliminate the need for costly, complex, and large filter media recycling equipment. This pelletizing step also generates a more environmentally acceptable solid waste product and provides the potential to incorporate gas-phase contaminant sorbents into the filtering media. Secondly, the S-MGBF system passes these pellets and the flyash laden power plant gas through a highly compact S-MGBF that uses cocurrent gas-pellet contacting in an arrangement that greatly simplifies and enhances the distribution of dirty gas to the moving bed and the disengagement of clean gas from the moving bed.

  1. Moving granular-bed filter development program - option 1 - component test facilities

    SciTech Connect (OSTI)

    Newby, R.A.; Yang, W.C.; Smelzer, E.E.; Lippert, T.E.

    1995-08-01

    The Westinghouse Science & Technology Center has proposed a novel moving granular bed filter concept, the Standleg Moving Granular Bed Filter (SMGBF). The SMGBF has inherent advantages over the current state-of-the-art moving granular bed filter technology and is potentially competitive with ceramic barrier filters. The SMGBF system combines several unique features that make it highly effective for use in advanced coal-fueled power plants, such as pressurized fluidized-bed combustion (PFBC), and integrated coal-gasification combined cycles (IGCC). The SMGBF is being developed in a phased program having an initial Base Contract period followed by optional periods. The Base Contract period was successfully completed and previously documented by Westinghouse. The Option 1 period, {open_quote}Component Test Facilities{close_quotes}, has also been completed and its results are reported in this document. The objective of the Option 1 program was to optimize the performance of the SMGBF system through component testing focused on the major technology issues. The SMGBF has been shown to be a viable technology in both cold flow simulations and high-temperature, high-pressure testing, and conditions to lead to best performance levels have been identified. Several development activities remain to be complete before the SMGBF can achieve commercial readiness.

  2. Mechanisms for impulsive energy dissipation and small scale effects in micro-granular media

    E-Print Network [OSTI]

    Jonathan Bunyan; Alexander F. Vakakis; Sameh Tawfick

    2015-08-04

    We study impulse response in 1-D homogeneous micro-granular chains on a linear elastic substrate. Micro-granular interactions are analytically described by the Schwarz contact model which includes nonlinear compressive as well as snap-to/from-contact adhesive effects forming a hysteretic loop in the force deformation relationship. We observe complex transient dynamics, including disintegration of solitary pulses, local clustering and low- to high-frequency energy transfers resulting in enhanced energy dissipation. We study in detail the underlying dynamics of cluster formation in the impulsively loaded medium, and relate enhanced energy dissipation to the rate of cluster formation. These unusual and interesting dynamical phenomena are shown to be robust over a range of physically feasible conditions, and are solely scale effects, since they are attributed to surface forces, which have no effect at the macro-scale. We establish a universal relation between the re-clustering rate and the effective damping in these systems. Our findings demonstrate that scale effects generating new nonlinear features can drastically affect the dynamics and acoustics of micro-granular materials.

  3. Deformation-Driven Diffusion and Plastic Flow in Two-Dimensional Amorphous Granular Pillars

    E-Print Network [OSTI]

    Wenbin Li; Jennifer M. Rieser; Andrea J. Liu; Douglas J. Durian; Ju Li

    2015-02-04

    We report a combined experimental and simulation study of deformation-induced diffusion in compacted two-dimensional amorphous granular pillars, in which thermal fluctuations play negligible role. The pillars, consisting of bidisperse cylindrical acetal plastic particles standing upright on a substrate, are deformed uniaxially and quasistatically by a rigid bar moving at a constant speed. The plastic flow and particle rearrangements in the pillars are characterized by computing the best-fit affine transformation strain and non-affine displacement associated with each particle between two stages of deformation. The non-affine displacement exhibits exponential crossover from ballistic to diffusive behavior with respect to the cumulative deviatoric strain, indicating that in athermal granular packings, the cumulative deviatoric strain plays the role of time in thermal systems and drives effective particle diffusion. We further study the size-dependent deformation of the granular pillars by simulation, and find that different-sized pillars follow self-similar shape evolution during deformation. In addition, the yield stress of the pillars increases linearly with pillar size. Formation of transient shear lines in the pillars during deformation becomes more evident as pillar size increases. The width of these elementary shear bands is about twice the diameter of a particle, and does not vary with pillar size.

  4. Tsunami generated by a granular collapse down a rough inclined plane

    E-Print Network [OSTI]

    Viroulet, Sylvain; Kimmoun, Olivier

    2014-01-01

    In this Letter, we experimentally investigate the collapse of initially dry granular media into water and the subsequent impulse waves. We systematically characterize the influence of the slope angle and the granular material on the initial amplitude of the generated leading wave and the evolution of its amplitude during the propagation. The experiments show that whereas the evolution of the leading wave during the propagation is well predicted by a solution of the linearized Korteweg-de Vries equation, the generation of the wave is more complicated to describe. Our results suggest that the internal properties of the granular media and the interplay with the surrounding fluid are important parameters for the generation of waves at low velocity impacts. Moreover, the amplitude of the leading wave reaches a maximum value at large slope angle. The runout distance of the collapse is also shown to be smaller in the presence of water than under totally dry conditions. This study provides a first insight into tsunam...

  5. Catalytic iron oxide for lime regeneration in carbonaceous fuel combustion

    DOE Patents [OSTI]

    Shen, Ming-Shing (Rocky Point, NY); Yang, Ralph T. (Middle Island, NY)

    1980-01-01

    Lime utilization for sulfurous oxides absorption in fluidized combustion of carbonaceous fuels is improved by impregnation of porous lime particulates with iron oxide. The impregnation is achieved by spraying an aqueous solution of mixed iron sulfate and sulfite on the limestone before transfer to the fluidized bed combustor, whereby the iron compounds react with the limestone substrate to form iron oxide at the limestone surface. It is found that iron oxide present in the spent limestone acts as a catalyst to regenerate the spent limestone in a reducing environment. With only small quantities of iron oxide the calcium can be recycled at a significantly increased rate.

  6. Tropical forest soil microbial communities couple iron and carbon biogeochemistry

    SciTech Connect (OSTI)

    Dubinsky, E.A.; Silver, W.L.; Firestone, M.K.

    2009-10-15

    We report that iron-reducing bacteria are primary mediators of anaerobic carbon oxidation in upland tropical soils spanning a rainfall gradient (3500 - 5000 mm yr-1) in northeast Puerto Rico. The abundant rainfall and high net primary productivity of these tropical forests provide optimal soil habitat for iron-reducing and iron-oxidizing bacteria. Spatially and temporally dynamic redox conditions make iron-transforming microbial communities central to the belowground carbon cycle in these wet tropical forests. The exceedingly high abundance of iron-reducing bacteria (up to 1.2 x 10{sup 9} cells per gram soil) indicated that they possess extensive metabolic capacity to catalyze the reduction of iron minerals. In soils from the higher rainfall sites, measured rates of ferric iron reduction could account for up to 44 % of organic carbon oxidation. Iron reducers appeared to compete with methanogens when labile carbon availability was limited. We found large numbers of bacteria that oxidize reduced iron at sites with high rates of iron reduction and large numbers of iron-reducers. the coexistence of large populations of ironreducing and iron-oxidizing bacteria is evidence for rapid iron cycling between its reduced and oxidized states, and suggests that mutualistic interactions among these bacteria ultimately fuel organic carbon oxidation and inhibit CH4 production in these upland tropical forests.

  7. Broad iron lines in Active Galactic Nuclei

    E-Print Network [OSTI]

    A. C. Fabian; K. Iwasawa; C. S. Reynolds; A. J. Young

    2000-04-26

    An intrinsically narrow line emitted by an accretion disk around a black hole appears broadened and skewed as a result of the Doppler effect and gravitational redshift. The fluorescent iron line in the X-ray band at 6.4-6.9keV is the strongest such line and is seen in the X-ray spectrum of many active galactic nuclei and, in particular, Seyfert galaxies. It is an important diagnostic with which to study the geometry and other properties of the accretion flow very close to the central black hole. The broad iron line indicates the presence of a standard thin accretion disk in those objects, often seen at low inclination. The broad iron line has opened up strong gravitational effects around black holes to observational study with wide-reaching consequences for both astrophysics and physics.

  8. Iron Availability in the Southern Ocean

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACT EVALUATIONIntroducing the RichardBudgetIowaOctoberNovember 3,IronIron

  9. The marine biogeochemistry of dissolved and colloidal iron

    E-Print Network [OSTI]

    Fitzsimmons, Jessica Nicole

    2013-01-01

    Iron is a redox active trace metal micronutrient essential for primary production and nitrogen acquisition in the open ocean. Dissolved iron (dFe) has extremely low concentrations in marine waters that can drive phytoplankton ...

  10. Preparations of rare earth-iron alloys by thermite reduction

    DOE Patents [OSTI]

    Schmidt, F.A.; Peterson, D.T.; Wheelock, J.T.

    1985-10-28

    Disclosed is an improved method for the preparation of high-purity rare earth-iron alloys by the aluminothermic reduction of a mixture of rare earth and iron fluorides.

  11. Candidate anode materials for iron production by molten oxide electrolysis

    E-Print Network [OSTI]

    Paramore, James D

    2010-01-01

    Molten oxide electrolysis (MOE) has been identified by the American Iron and Steel Institute (AISI) as one of four possible breakthrough technologies to alleviate the environmental impact of iron and steel production. This ...

  12. Iron acquisition and utilization by Rhodococcus equi: potential virulence factors 

    E-Print Network [OSTI]

    Carnes, Misty Lee

    2002-01-01

    The course of any infection depends upon the pathogenicity of a particular organism and the status of the host's defense mechanisms. Because most bacterial pathogens need iron to multiply, they must develop mechanisms to acquire iron...

  13. Evaluation of Characterization Techniques for Iron Pipe Corrosion...

    Office of Scientific and Technical Information (OSTI)

    by drinking water studies is that of properly characterizing the corrosion products (CP) in iron pipescor synthetic Fe (hydr)oxides used to simulate the iron pipe used in...

  14. Contribution of Iron-Reducing Bacteria to Mercury Methylation in Marine Sediments

    E-Print Network [OSTI]

    Fleming, Emily J.; Nelson, D C

    2006-01-01

    iron, which is characteristic of acid weathering of exposed miningexposed mining areas, a suite of other metals (such as iron,

  15. Minnesota Jobs to Come with Efficient Iron Plant

    Broader source: Energy.gov [DOE]

    New energy-efficient iron plant offers a ray of hope for workers after local mining company shuts down.

  16. Bronze metallurgy in Iron Age central Europe : a metallurgical study of Early Iron Age bronzes from Sti?na, Slovenia.

    E-Print Network [OSTI]

    Cooney, Elizabeth Myers

    2007-01-01

    The Early Iron Age (750-450 BCE) marks a time in the European Alpine Region in which cultural ideologies surrounding bronze objects and bronze production were changing. Iron was becoming the preferred material from which ...

  17. Reduction of Vinyl Chloride in Metallic Iron-Water Systems

    E-Print Network [OSTI]

    Deng, Baolin

    Reduction of Vinyl Chloride in Metallic Iron-Water Systems B A O L I N D E N G * Department of Mineral and Environmental Engineering, New Mexico Institute of Mining and Technology, Socorro, New Mexico) reduction by metallic iron in aqueous systems were performed. The effects of various iron loadings, VC

  18. Iron distribution and phytoplankton iron limitation in the southern California Current System

    E-Print Network [OSTI]

    King, Andrew Luke

    2008-01-01

    layer density (sigma-theta) are shown for six CalCOFI surveysolution (Sigma-Aldrich) in 0.016 M ultrapure HCl every sixsigma-theta. Macronutrients, dissolved iron, and chl were elevated during all six

  19. Iron Air collision with high density QCD

    E-Print Network [OSTI]

    Hans-Joachim Drescher

    2006-12-08

    The color glass condensate approach describes successfully heavy ion collisions at RHIC. We investigate Iron-air collisions within this approach and compare results to event generators commonly used in air shower simulations. We estimate uncertainties in the extrapolation to GZK energies and discuss implications for air shower simulations.

  20. Iron loss calculation for synchronous reluctance machines

    SciTech Connect (OSTI)

    Leonardi, F.; Matsuo, T.; Lipo, T.A. [Univ. of Wisconsin, Madison, WI (United States)

    1995-12-31

    A numerical method for iron loss calculation is presented in this paper. The method is suitable for any synchronous and most dc machines, especially if the current waveforms are known a priori . This technique will be principally useful for high speed machines and in particular for the synchronous reluctance machines and in particular for the synchronous reluctance machine, where the iron losses are often an important issue. The calculation is based on Finite Element Analysis, which provides the flux density waveforms in the iron, and on the Fourier Analysis of these waveforms. Several Finite Element Simulations are necessary to obtain the induced voltage versus time waveforms. To reduce the post-processing time the majority of the elements of the model are grouped together to create super elements. Also the periodicity of the motor can be used to reduce the number of required simulations. The method is applied to the calculation of the iron losses of a synchronous reluctance generator, and a number of interesting results are discussed in the paper.

  1. Superconductivity in iron compounds G. R. Stewart

    E-Print Network [OSTI]

    Wu, Zhigang

    of the superconductivity in this new class of compounds. These iron pnictide and chalcogenide (FePn/Ch) superconductors-phonon coupled ``conventional'' superconductors. Clearly, superconductivity and magnetism or magnetic of magnetism and superconductivity in FePn/Ch superconductors 1606 D. Tc and TS=TSDW versus pressure 1607 1

  2. Iron oxyhydroxide mineralization on microbial extracellular polysaccharides

    E-Print Network [OSTI]

    Iron oxyhydroxide mineralization on microbial extracellular polysaccharides Clara S. Chan a oxidation and create polymers that localize mineral precipitation. In order to classify the microbial polymers that influence FeOOH miner- alogy, we studied the organic and mineral components of biominerals

  3. The magnetic properties of the iron-rich, iron-nickel-zinc alloys 

    E-Print Network [OSTI]

    Gupton, Paul Stephen

    1961-01-01

    THE MAGNETIC PROPERTIES OF THE IRON-RICH, IRON-NICKEL-ZINC ALLOYS A Thesis By Paul Stephen Gupton Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial fulfillment of the requirements for the degree...' work. Accordingly, the decision was reached that only explora- tory studies would be made. These would involve mechanical hardness and magnetic properties and a limited number of tests of corrosion re- sistance. 950 900 850 9IO II+ L 800 750...

  4. Development of an integrated, in-situ remediation technology. Topical report for task No. 9. Part I. TCE degradation using nonbiological methods, September 26, 1994--May 25, 1996

    SciTech Connect (OSTI)

    Shapiro, A.P.; Sivavec, T.M.; Baghel, S.S. [General Electric Research and Development, Schenectady, NY (United States)

    1997-04-01

    Contamination in low-permeability soils poses a significant technical challenge for in situ remediation efforts. Poor accessibility to the contaminants and difficulty in delivery of treatment reagents have rendered existing in situ treatments such as bioremediation, vapor extraction, pump and treat rather ineffective when applied to low-permeability soils present at many contaminated sites. The technology is an integrated in situ treatment in which established geotechnical methods are used to install degradation zones directly in the contaminated soil and electro-osmosis is used to move the contaminants back and forth through those zones until the treatment is completed. The present Draft Topical Report for Task No. 9 summarizes laboratory investigations into TCE degradation using nonbiological methods. These studies were conducted by the General Electric Company. The report concentrates on zero valent iron as the reducing agent and presents data on TCE and daughter product degradation rates in batch experiments, column studies, and electroosmotic cells. It is shown that zero valent iron effectively degrades TCE in electroosmotic experiments. Daughter product degradation and gas generation are shown to be important factors in designing field scale treatment zones for the Lasagna{trademark} process.

  5. Continuous production of granular or powder Ti, Zr and Hf or their alloy products

    DOE Patents [OSTI]

    White, Jack C. (Albany, OR); Oden, Laurance L. (Albany, OR)

    1993-01-01

    A continuous process for producing a granular metal selected from the group consisting of Ti, Zr or Hf under conditions that provide orderly growth of the metal free of halide inclusions comprising: a) dissolving a reducing metal selected from the group consisting of Na, Mg, Li or K in their respective halide salts to produce a reducing molten salt stream; b) preparing a second molten salt stream containing the halide salt of Ti, Zr or Hf; c) mixing and reacting the two molten streams of steps a) and b) in a continuous stirred tank reactor; d) wherein steps a) through c) are conducted at a temperature range of from about 800.degree. C. to about 1100.degree. C. so that a weight percent of equilibrium solubility of the reducing metal in its respective halide salt varies from about 1.6 weight percent at about 900.degree. C. to about 14.4 weight percent at about 1062.degree. C.; and wherein a range of concentration of the halide salt of Ti, Zn or Hf in molten halides of Na, Mg, Li or K is from about 1 to about 5 times the concentration of Na, Mg, Li or K; e) placing the reacted molten stream from step c) in a solid-liquid separator to recover an impure granular metal product by decantation, centrifugation, or filtration; and f) removing residual halide salt impurity by vacuum evaporator or inert gas sweep at temperatures from about 850.degree. C. to 1000.degree. C. or cooling the impure granular metal product to ambient temperature and water leaching off the residual metal halide salt.

  6. Non-Newtonian hydrodynamics for a dilute granular suspension under uniform shear flow

    E-Print Network [OSTI]

    Moisés G. Chamorro; F. Vega Reyes; V. Garzó

    2015-07-07

    We study in this work a steady shearing laminar flow with null heat flux (usually called "uniform shear flow") in a gas-solid suspension at low density. The solid particles are modeled as a gas of smooth hard spheres with inelastic collisions while the influence of the surrounding interstitial fluid on the dynamics of grains is modeled by means of a volume drag force, in the context of a rheological model for suspensions. The model is solved by means of three different but complementary routes, two of them being theoretical (Grad's moment method applied to the corresponding Boltzmann equation and an exact solution of a kinetic model adapted to granular suspensions) and the other being computational (Monte Carlo simulations of the Boltzmann equation). Unlike in previous studies on granular sheared suspensions, we include in our Grad's solution nonlinear terms in the stress tensor in the collisional moment associated with the momentum transfer. This theoretical enhancement allows us for the detection and evaluation of the normal stress differences in the plane normal to the laminar flow. In addition, the exact solution of the kinetic model gives the explicit form of the velocity moments of the velocity distribution function. Comparison between our theoretical and numerical results shows in general a good agreement for the non-Newtonian rheological properties, the kurtosis (fourth velocity moment of the distribution function) and the velocity distribution of the kinetic model for quite strong inelasticity and not too large values of the (scaled) friction coefficient characterizing the viscous drag force. This shows the accuracy of our analytical results that allows us to describe in detail the flow dynamics of the granular suspension with zero heat flux throughout the paper.

  7. Development and Testing of a Moving Granular Bed Filter at the Taiwan Industrial Technology Research Institute

    SciTech Connect (OSTI)

    Peng, C.Y.; Hsiau, S-S.; Lee, H-T.; Smid, J.; Wu, T-C.

    2002-09-18

    The main purpose of developing high temperature gas cleaning technologies are to clean the gas under high temperature in order to be cost effective and to improve energy efficiency. Moving granular bed filters are technically and economically applicable for high temperature cleaning system because of low cost, possible to keep operation at a constant pressure drop, simple structure, easy in operation and maintenance, no high risk internals, and more tolerant to process thermal flow. Energy and Resource Laboratories, Taiwan Industrial Technology Research Institute (ERL/ITRI) has been developing a moving granular bed filter (MGBF) for BIGCC(Biomass Integrated Gasification Combined Cycle) high temperature gas cleanup. The filter granules move downwards directed by louver-like guide plates and the hot gases penetrate the MGBF horizontally. Filtration mechanisms include collection of the dust cake over the bed media surface and deep bed filtration. Stagnant zones of filter granules combining with the dusts always exist along the louver walls. Such stagnant zones often corrode the louver-like guide plates, increase the system pressure drop and decrease the total reaction efficiency that may endanger MGBF operation. Series louver and inert structure research that modify the granular flow pattern have been designed to eliminate the formation of these stagnant zones. By connecting to an auxiliary dust/bed media separation system, MGBF can be operated continuously at a stable pressure drop with a stable high efficiency. There are several MGBF R&D activities in progress: (1) a 3-dimensional cold flow system for testing the MGBF filtration efficiency; (2) a high temperature gas cleanup experimental system that has been designed and installed; (3) a 2-dimensional flow pattern experimental system for approving design concepts.

  8. The jamming surface of granular matter determined from soil mechanics results

    E-Print Network [OSTI]

    P. Evesque

    2005-06-17

    Classical soil mechanics results are used to propose the equation of the jamming transition surface in the (stress, specific volume) space. Taking axis-ymmetric conditions, labelling q the deviatoric stress and p' the mean pressure applied on the granular skeleton, and considering normal range of pressure (10 kPa-10MPa) the equation of the surface of jamming transition is v = vo-m ln(p'/p'o)+ md ln(1+q q/(M' M' p' p')); M' is related to the friction angle, m and md are two constants which depend on soil characteristics; p'o is a "unit" pressure.

  9. Shear Zones in granular materials: Optimization in a self-organized random potential

    E-Print Network [OSTI]

    J Torok; T. Unger; J. Kertesz; D. E. Wolf

    2006-07-06

    We introduce a model to describe the wide shear zones observed in modified Couette cell experiments with granular material. The model is a generalization of the recently proposed approach based on a variational principle. The instantaneous shear band is identified with the surface that minimizes the dissipation in a random potential that is biased by the local velocity difference and pressure. The apparent shear zone is the ensemble average of the instantaneous shear bands. The numerical simulation of this model matches excellently with experiments and has measurable predictions.

  10. Testing Hadronic Interaction Models using a Highly Granular Silicon-Tungsten Calorimeter

    E-Print Network [OSTI]

    The CALICE Collaboration; B. Bilki; J. Repond; J. Schlereth; L. Xia; Z. Deng; Y. Li; Y. Wang; Q. Yue; Z. Yang; G. Eigen; Y. Mikami; T. Price; N. K. Watson; M. A. Thomson; D. R. Ward; D. Benchekroun; A. Hoummada; Y. Khoulaki; C. Cârloganu; S. Chang; A. Khan; D. H. Kim; D. J. Kong; Y. D. Oh; G. C. Blazey; A. Dyshkant; K. Francis; J. G. R. Lima; P. Salcido; V. Zutshi; V. Boisvert; B. Green; A. Misiejuk; F. Salvatore; K. Kawagoe; Y. Miyazaki; Y. Sudo; T. Suehara; T. Tomita; H. Ueno; T. Yoshioka; J. Apostolakis; G. Folger; G. Folger; V. Ivantchenko; A. Ribon; V. Uzhinskiy; S. Cauwenbergh; M. Tytgat; N. Zaganidis; J. -Y. Hostachy; L. Morin; K. Gadow; P. Göttlicher; C. Günter; K. Krüger; B. Lutz; M. Reinecke; F. Sefkow; N. Feege; E. Garutti; S. Laurien; S. Lu; I. Marchesini; M. Matysek; M. Ramilli; A. Kaplan; E. Norbeck; D. Northacker; Y. Onel; E. J. Kim; B. van Doren; G. W. Wilson; M. Wing; B. Bobchenko; M. Chadeeva; R. Chistov; M. Danilov; A. Drutskoy; A. Epifantsev; O. Markin; R. Mizuk; E. Novikov; V. Popov; V. Rusinov; E. Tarkovsky; D. Besson; E. Popova; M. Gabriel; C. Kiesling; F. Simon; C. Soldner; M. Szalay; M. Tesar; L. Weuste; M. S. Amjad; J. Bonis; S. Callier; S. Conforti di Lorenzo; P. Cornebise; Ph. Doublet; F. Dulucq; M. Faucci-Giannelli; J. Fleury; T. Frisson; B. Kégl; N. van der Kolk; H. Li; G. Martin-Chassard; F. Richard; Ch. de la Taille; R. Pöschl; L. Raux; J. Rouëné; N. Seguin-Moreau; M. Anduze; V. Balagura; E. Becheva; V. Boudry; J-C. Brient; R. Cornat; M. Frotin; F. Gastaldi; F. Magniette; A. Matthieu; P. Mora de Freitas; H. Videau; J-E. Augustin; J. David; P. Ghislain; D. Lacour; L. Lavergne; J. Zacek; J. Cvach; P. Gallus; M. Havranek; M. Janata; J. Kvasnicka; D. Lednicky; M. Marcisovsky; I. Polak; J. Popule; L. Tomasek; M. Tomasek; P. Ruzicka; P. Sicho; J. Smolik; V. Vrba; J. Zalesak; D. Jeans; M. Götze

    2015-05-08

    A detailed study of hadronic interactions is presented using data recorded with the highly granular CALICE silicon-tungsten electromagnetic calorimeter. Approximately 350,000 selected negatively charged pion events at energies between 2 and 10 GeV have been studied. The predictions of several physics models available within the Geant4 simulation tool kit are compared to this data. A reasonable overall description of the data is observed; the Monte Carlo predictions are within 20% of the data, and for many observables much closer. The largest quantitative discrepancies are found in the longitudinal and transverse distributions of reconstructed energy.

  11. Power law in the angular velocity distribution of a granular needle

    E-Print Network [OSTI]

    J. Piasecki; P. Viot

    2005-12-27

    We show how inelastic collisions induce a power law with exponent -3 in the decay of the angular velocity distribution of anisotropic particles with sufficiently small moment of inertia. We investigate this question within the Boltzmann kinetic theory for an elongated granular particle immersed in a bath. The power law persists so long as the collisions are inelastic for a large range of angular velocities provided the mass ratio of the anisotropic particle and the bath particles remains small. Suggestions for observing this peculiar feature are made.

  12. Study of Micro Pixel Photon Counters for a high granularity scintillator-based hadron calorimeter

    E-Print Network [OSTI]

    D'Ascenzo, N; Garutti, E

    2007-01-01

    A new Geiger mode avalanche photodiode, the Micro Pixel Photon Counter (MPPC), was recently released by Hamamatsu. It has a high photo-detection efficiency in the 420 nm spectral region. This product can represent an elegant candidate for the design of a high granularity scintillator based hadron calorimeter for the International Linear Collider. In fact, the direct readout of the blue scintillation photons with a MPPC is a feasible techological solution. The readout of a plastic scintillator by a MPPC, both mediated by the traditional wavelength shifting fiber, and directly coupled, has been systematically studied.

  13. Method for preparing hydrous iron oxide gels and spherules

    DOE Patents [OSTI]

    Collins, Jack L.; Lauf, Robert J.; Anderson, Kimberly K.

    2003-07-29

    The present invention is directed to methods for preparing hydrous iron oxide spherules, hydrous iron oxide gels such as gel slabs, films, capillary and electrophoresis gels, iron monohydrogen phosphate spherules, hydrous iron oxide spherules having suspendable particles homogeneously embedded within to form composite sorbents and catalysts, iron monohydrogen phosphate spherules having suspendable particles of at least one different sorbent homogeneously embedded within to form a composite sorbent, iron oxide spherules having suspendable particles homogeneously embedded within to form a composite of hydrous iron oxide fiber materials, iron oxide fiber materials, hydrous iron oxide fiber materials having suspendable particles homogeneously embedded within to form a composite, iron oxide fiber materials having suspendable particles homogeneously embedded within to form a composite, dielectric spherules of barium, strontium, and lead ferrites and mixtures thereof, and composite catalytic spherules of barium or strontium ferrite embedded with oxides of Mg, Zn, Pb, Ce and mixtures thereof. These variations of hydrous iron oxide spherules and gel forms prepared by the gel-sphere, internal gelation process offer more useful forms of inorganic ion exchangers, catalysts, getters, dielectrics, and ceramics.

  14. Role of gravity or confining pressure and contact stiffness in granular rheology

    E-Print Network [OSTI]

    Abhinendra Singh; Vanessa Magnanimo; Kuniyasu Saitoh; Stefan Luding

    2014-12-02

    The steady shear rheology of granular materials is investigated in slow quasi-static states and inertial flows. The effect of the gravity field and contact stiffness, which are conventionally trivialized is the focus of this study. Series of Discrete Element Method simulations are performed on a weakly frictional granular assembly in a split-bottom geometry considering various gravity fields and contact stiffnesses. While traditionally the inertial number, i.e., the ratio of stress to strain-rate timescales describes the flow rheology, we find that a second dimensionless number, the ratio of softness and stress timescales, must also be included to characterize the bulk flow behavior. For slow, quasi-static flows, the density increases while the macroscopic friction decreases with respective increase in particle softness and gravity. This trend is added to the $\\mu(I)$ rheology and can be traced back to the anisotropy in the contact network, displaying a linear correlation between macroscopic friction and deviatoric fabric in the steady state. Interestingly, the linear relation holds when the external rotation rate is increased for a given gravity field and contact stiffness.

  15. Kinematic flow patterns in slow deformation of a dense granular material

    E-Print Network [OSTI]

    Koushik Viswanathan; Anirban Mahato; Tejas G. Murthy; Tomasz Koziara; Srinivasan Chandrasekar

    2015-07-19

    The kinematic flow pattern in slow deformation of a model dense granular medium is studied at high resolution using \\emph{in situ} imaging, coupled with particle tracking. The deformation configuration is indentation by a flat punch under macroscopic plane-strain conditions. Using a general analysis method, velocity gradients and deformation fields are obtained from the disordered grain arrangement, enabling flow characteristics to be quantified. The key observations are the formation of a stagnation zone, as in dilute granular flow past obstacles; occurrence of vortices in the flow immediately underneath the punch; and formation of distinct shear bands adjoining the stagnation zone. The transient and steady state stagnation zone geometry, as well as the strength of the vortices and strain rates in the shear bands, are obtained from the experimental data. All of these results are well-reproduced in exact-scale Non-Smooth Contact Dynamics (NSCD) simulations. Full 3D numerical particle positions from the simulations allow extraction of flow features that are extremely difficult to obtain from experiments. Three examples of these, namely material free surface evolution, deformation of a grain column below the punch and resolution of velocities inside the primary shear band, are highlighted. The variety of flow features observed in this model problem also illustrates the difficulty involved in formulating a complete micromechanical analytical description of the deformation.

  16. Extraction of Force-Chain Network Architecture in Granular Materials Using Community Detection

    E-Print Network [OSTI]

    Danielle S. Bassett; Eli T. Owens; Mason A. Porter; M. Lisa Manning; Karen E. Daniels

    2015-04-23

    Force chains form heterogeneous physical structures that can constrain the mechanical stability and acoustic transmission of granular media. However, despite their relevance for predicting bulk properties of materials, there is no agreement on a quantitative description of force chains. Consequently, it is difficult to compare the force-chain structures in different materials or experimental conditions. To address this challenge, we treat granular materials as spatially-embedded networks in which the nodes (particles) are connected by weighted edges that represent contact forces. We use techniques from community detection, which is a type of clustering, to find sets of closely connected particles. By using a geographical null model that is constrained by the particles' contact network, we extract chain-like structures that are reminiscent of force chains. We propose three diagnostics to measure these chain-like structures, and we demonstrate the utility of these diagnostics for identifying and characterizing classes of force-chain network architectures in various materials. To illustrate our methods, we describe how force-chain architecture depends on pressure for two very different types of packings: (1) ones derived from laboratory experiments and (2) ones derived from idealized, numerically-generated frictionless packings. By resolving individual force chains, we quantify statistical properties of force-chain shape and strength, which are potentially crucial diagnostics of bulk properties (including material stability). These methods facilitate quantitative comparisons between different particulate systems, regardless of whether they are measured experimentally or numerically.

  17. Lift and drag in intruders moving through hydrostatic granular media at high speeds

    E-Print Network [OSTI]

    Potiguar, Fabricio Q

    2013-01-01

    Recently, experiments showed that forces on intruders dragged horizontally through dense, hydrostatic granular packings mainly depend on the local surface orientation and can be seen as the sum of the forces exerted on small surface elements. In order to understand such forces more deeply, we perform 2D soft-sphere molecular dynamics simulation, on similar set up, of an intruder dragged through a 50-50 bi-disperse granular packing, with diameters 0.30 and 0.34 cm. We measure, for both circular and half-circle shapes, the forces parallel (drag) and perpendicular (lift) to the drag direction as functions of the drag speed, with V=10.3-309 cm/s, and intruder depths, with D=3.75-37.5 cm. The drag forces on an intruder monotonically increase with V and D, and are larger for the circle. However, the lift force does not depend monotonically on V and D, and this relationship is affected by the shape of the intruder. The vertical force was negative for the half-circle, but for a small range of V and D, we measure posi...

  18. Turning intractable counting into sampling: computing the granular entropy of three-dimensional jammed packings

    E-Print Network [OSTI]

    Stefano Martiniani; K. Julian Schrenk; Jacob D. Stevenson; David J. Wales; Daan Frenkel

    2015-09-14

    We report a numerical calculation of the total number of disordered jammed configurations $\\Omega$ of $N$ repulsive, three-dimensional spheres in a fixed volume $V$. To make these calculations tractable, we increase the computational efficiency of the approach of Xu et al. (Phys. Rev. Lett. 106, 245502 (2011)) and Asenjo et al. (Phys. Rev. Lett. 112, 098002 (2014)) and we extend the method to allow computation of the granular entropy as a function of pressure. The approach that we use computes the granular entropy by sampling the absolute volume of basins of attraction of the stable packings in the potential energy landscape. We find a surprisingly strong correlation between the pressure of a configuration and the volume of its basin of attraction in the potential energy landscape. This relation is well described by a power law. Our methodology to compute the number of stable packings should be applicable to a wide range of other enumeration problems that aims to find the extrema of a scalar cost function that depends on many degrees of freedom.

  19. Turning intractable counting into sampling: computing the granular entropy of three-dimensional jammed packings

    E-Print Network [OSTI]

    Martiniani, Stefano; Stevenson, Jacob D; Wales, David J; Frenkel, Daan

    2015-01-01

    We report a numerical calculation of the total number of disordered jammed configurations $\\Omega$ of $N$ repulsive, three-dimensional spheres in a fixed volume $V$. To make these calculations tractable, we increase the computational efficiency of the approach of Xu et al. (Phys. Rev. Lett. 106, 245502 (2011)) and Asenjo et al. (Phys. Rev. Lett. 112, 098002 (2014)) and we extend the method to allow computation of the granular entropy as a function of pressure. The approach that we use computes the granular entropy by sampling the absolute volume of basins of attraction of the stable packings in the potential energy landscape. We find a surprisingly strong correlation between the pressure of a configuration and the volume of its basin of attraction in the potential energy landscape. This relation is well described by a power law. Our methodology to compute the number of stable packings should be applicable to a wide range of other enumeration problems that aims to find the extrema of a scalar cost function tha...

  20. Analysis of Granular Flow in a Pebble-Bed Nuclear Reactor

    E-Print Network [OSTI]

    Chris H. Rycroft; Gary S. Grest; James W. Landry; Martin Z. Bazant

    2006-02-16

    Pebble-bed nuclear reactor technology, which is currently being revived around the world, raises fundamental questions about dense granular flow in silos. A typical reactor core is composed of graphite fuel pebbles, which drain very slowly in a continuous refueling process. Pebble flow is poorly understood and not easily accessible to experiments, and yet it has a major impact on reactor physics. To address this problem, we perform full-scale, discrete-element simulations in realistic geometries, with up to 440,000 frictional, viscoelastic 6cm-diameter spheres draining in a cylindrical vessel of diameter 3.5m and height 10m with bottom funnels angled at 30 degrees or 60 degrees. We also simulate a bidisperse core with a dynamic central column of smaller graphite moderator pebbles and show that little mixing occurs down to a 1:2 diameter ratio. We analyze the mean velocity, diffusion and mixing, local ordering and porosity (from Voronoi volumes), the residence-time distribution, and the effects of wall friction and discuss implications for reactor design and the basic physics of granular flow.

  1. Grad's moment method for a granular fluid at moderate densities. Navier-Stokes transport coefficients

    E-Print Network [OSTI]

    Vicente Garzó

    2013-03-18

    The Navier-Stokes transport coefficients of a granular dense fluid of smooth inelastic hard disks or spheres are explicitly determined by solving the inelastic Enskog equation by means of Grad's moment method. The transport coefficients are explicitly determined as functions of the (constant) coefficient of restitution and the solid volume fraction. In addition, the cooling rate is also calculated to first order in the spatial gradients. The calculations are performed for an arbitrary number of dimensions. The results are not limited to small dissipation and are expected to apply at moderate densities. It is found that the expressions of the Navier-Stokes transport coefficients and the cooling rate agree with those previously obtained from the Chapman-Enskog method by using the leading terms in a Sonine polynomial expansion. This shows the equivalence between both methods for granular fluids in the Navier-Stokes approximation. A comparison with previous results derived from Grad's moment method for inelastic disks and spheres is also carried out.

  2. An Itinerant Oscillator model with cage inertia for mesorheological granular experiments

    E-Print Network [OSTI]

    A. Lasanta; A. Puglisi

    2015-08-03

    Recent experiments with a rotating probe immersed in weakly fluidized granular materials show a complex behavior on a wide range of timescales. Viscous-like relaxation at high frequency is accom- panied by an almost harmonic dynamical trapping at intermediate times, with possibly anomalous long time behavior in the form of super-diffusion. Inspired by the Itinerant Oscillator model for dif- fusion in molecular liquids, and other models with coupled thermostats acting at different timescales, here we discuss a new model able to account for fast viscous relaxation, dynamical trapping and super-diffusion at long times. The main difference with respect to liquids, is a non-negligible cage inertia for the surrounding (granular) fluid, which allows it to sustain a slow but persistent mo- tion for long times. The computed velocity power density spectra and mean-squared displacement qualitatively reproduce the experimental findings. We also discuss the linear response to external perturbations and the tail of the distribution of persistency time, which is associated with superdif- fusion, and whose cut-off time is determined by cage inertia.

  3. GRANULAR MICROBIAL HABITATS BUILT FROM IRON SULFIDES: ALTERNATIVE MICROBIAL LIFESTYLES? J. Schieber, Department of Geological Sciences, Indiana University, Bloomington, Indiana 47405,

    E-Print Network [OSTI]

    Schieber, Juergen

    @indiana.edu. Introduction: Concentrically zoned pyrite grains of sand to pebble size occur in shallow marine sandstones surface sediment. Cross-bedding and ripples in these sandstones indicate an energetic envi- ronment samples are from the lower Siyeh Formation, interbedded sandstones and carbona- ceous shales that were

  4. Water Clustering on Nanostructured Iron Oxide Films

    SciTech Connect (OSTI)

    Merte, L. R.; Bechstein, Ralf; Peng, Guowen; Rieboldt, Felix; Farberow, Carrie A.; Zeuthen, Helene; Knudsen, Jan; Laegsgaard, E.; Wendt, Stefen; Mavrikakis, Manos; Besenbacher, Fleming

    2014-06-30

    The adhesion of water to solid surfaces is characterized by the tendency to balance competing molecule–molecule and molecule–surface interactions. Hydroxyl groups form strong hydrogen bonds to water molecules and are known to substantially influence the wetting behaviour of oxide surfaces, but it is not well-understood how these hydroxyl groups and their distribution on a surface affect the molecular-scale structure at the interface. Here we report a study of water clustering on a moire´-structured iron oxide thin film with a controlled density of hydroxyl groups. While large amorphous monolayer islands form on the are film, the hydroxylated iron oxide film acts as a hydrophilic nanotemplate, causing the formation of a regular array of ice-like hexameric nanoclusters. The formation of this ordered phase is localized at the nanometre scale; with increasing water coverage, ordered and amorphous water are found to coexist at adjacent hydroxylated and hydroxyl-free domains of the moire´ structure.

  5. Iron-sulfide redox flow batteries

    DOE Patents [OSTI]

    Xia, Guan-Guang; Yang, Zhenguo; Li, Liyu; Kim, Soowhan; Liu, Jun; Graff, Gordon L

    2013-12-17

    Iron-sulfide redox flow battery (RFB) systems can be advantageous for energy storage, particularly when the electrolytes have pH values greater than 6. Such systems can exhibit excellent energy conversion efficiency and stability and can utilize low-cost materials that are relatively safer and more environmentally friendly. One example of an iron-sulfide RFB is characterized by a positive electrolyte that comprises Fe(III) and/or Fe(II) in a positive electrolyte supporting solution, a negative electrolyte that comprises S.sup.2- and/or S in a negative electrolyte supporting solution, and a membrane, or a separator, that separates the positive electrolyte and electrode from the negative electrolyte and electrode.

  6. Thin Wall Cast Iron: Phase II

    SciTech Connect (OSTI)

    Doru M. Stefanescu

    2005-07-21

    The development of thin-wall technology allows the designers of energy consuming equipment to select the most appropriate material based on cost/material properties considerations, and not solely on density. The technology developed in this research project will permit the designers working for the automotive industry to make a better informed choice between competing materials and thin wall cast iron, thus decreasing the overall cost of the automobile.

  7. Superconductivity at Dawn of the Iron Age

    ScienceCinema (OSTI)

    Tesanovic, Zlatko [Johns Hopkins University, Baltimore, Maryland, United States

    2010-09-01

    Superconductivity is a stunning quantum phenomenon and among the deepest paradigms in all of physics. From fundamental theories of the universe to strange goings-on in exotic materials to medical imaging and cell phones, its conceptual and practical dimensions span a reach as wide as anything in science. Twenty-odd years ago, the discovery of copper oxides ushered in a new era of high-temperature superconductivity, and the joyous exuberance that followed - with physicists throwing everything from fancy gauge theories to synchrotron radiation into its kitchen sink - only recently began to show any signs of waning. In the spring of 2008, as if on cue, a new family of iron pnictide high-temperature superconductors burst on the scene, hinting at an alternative route to room-temperature superconductivity and all of its momentous consequences. Fueled by genuine excitement - and a bit of hype - the iron-based superconductivity turned into a science blockbuster of 2009. I will present a pedagogical review of this new field, contrast the physics of iron- and copper-based systems, and speculate on the microscopic origins of the two types of high-temperature superconductivity.

  8. The iron abundance of the Magellanic Bridge

    E-Print Network [OSTI]

    P. L. Dufton; R. S. I. Ryans; H. M. A. Thompson; R. A. Street

    2008-02-01

    High-resolution HST ultra-violet spectra for five B-type stars in the Magellanic Bridge and in the Large and Small Magellanic Clouds have been analysed to estimate their iron abundances. Those for the Clouds are lower than estimates obtained from late-type stars or the optical lines in B-type stars by approximately 0.5 dex. This may be due to systematic errors possibly arising from non-LTE effects or from errors in the atomic data as similar low Fe abundances having previously been reported from the analysis of the ultra-violet spectra of Galactic early-type stars. The iron abundance estimates for all three Bridge targets appear to be significantly lower than those found for the SMC and LMC by approximately -0.5 dex and -0.8 dex respectively and these differential results should not be affected by any systematic errors present in the absolute abundance estimates. These differential iron abundance estimates are consistent with the underabundances for C, N, O, Mg and Si of approximately -1.1 dex relative to our Galaxy previously found in our Bridge targets. The implications of these very low metal abundances for the Magellanic Bridge are discussed in terms of metal deficient material being stripped from the SMC.

  9. Seal welded cast iron nuclear waste container

    DOE Patents [OSTI]

    Filippi, Arthur M. (Pittsburgh, PA); Sprecace, Richard P. (Murrysville, PA)

    1987-01-01

    This invention identifies methods and articles designed to circumvent metallurgical problems associated with hermetically closing an all cast iron nuclear waste package by welding. It involves welding nickel-carbon alloy inserts which are bonded to the mating plug and main body components of the package. The welding inserts might be bonded in place during casting of the package components. When the waste package closure weld is made, the most severe thermal effects of the process are restricted to the nickel-carbon insert material which is far better able to accommodate them than is cast iron. Use of nickel-carbon weld inserts should eliminate any need for pre-weld and post-weld heat treatments which are a problem to apply to nuclear waste packages. Although the waste package closure weld approach described results in a dissimilar metal combination, the relative surface area of nickel-to-iron, their electrochemical relationship, and the presence of graphite in both materials will act to prevent any galvanic corrosion problem.

  10. Structural characterization and statistical properties of two-dimensional granular systems Gad Frenkel,1,* Raphael Blumenfeld,1,2

    E-Print Network [OSTI]

    Blumenfeld, Rafi

    Frenkel,1,* Raphael Blumenfeld,1,2 Zdenek Grof,3 and Peter R. King1 1 Earth Science and Engineering conventional thermodynamic systems, loosely compressed granular materials are not in equilibrium unless science of porous media is based on the premise that the statistics of a given block of a particular rock

  11. Decompaction and fluidization of a saturated and confined granular medium by injection of a viscous liquid or gas

    E-Print Network [OSTI]

    Schmittbuhl, Jean

    in fluidized beds under gravity is perhaps the most studied issue related to this case 26­37 . NeverthelessDecompaction and fluidization of a saturated and confined granular medium by injection of a viscous rely, are rather poorly understood and their study is in its infancy. The case of bubbling instability

  12. Dynamic fracture of granular material under quasi-static loading , The Institute of Earth Sciences, The Hebrew University of Jerusalem

    E-Print Network [OSTI]

    Fineberg, Jay

    Dynamic fracture of granular material under quasi-static loading Amir Sagy1 , The Institute;Abstract The dynamics of rapid fracture in heterogeneous grainy media are studied in a series of laboratory experiments in which artificial rock slab is fractured under conditions of uniaxial tension. By performing

  13. European Journal of Mechanics A/Solids 25 (2006) 358369 An elastoplastic framework for granular materials becoming

    E-Print Network [OSTI]

    Bigoni, Davide

    2006-01-01

    of this paper. 2005 Elsevier SAS. All rights reserved. Keywords: Elastoplasticity; Large strains; Granular matter 2005 Elsevier SAS. All rights reserved. doi:10.1016/j.euromechsol.2005.10.002 #12;A. Piccolroaz; accepted 10 October 2005 Available online 22 November 2005 Abstract The two key phenomena occurring

  14. Iron phosphate compositions for containment of hazardous metal waste

    DOE Patents [OSTI]

    Day, D.E.

    1998-05-12

    An improved iron phosphate waste form for the vitrification, containment and long-term disposition of hazardous metal waste such as radioactive nuclear waste is provided. The waste form comprises a rigid iron phosphate matrix resulting from the cooling of a melt formed by heating a batch mixture comprising the metal waste and a matrix-forming component. The waste form comprises from about 30 to about 70 weight percent P{sub 2}O{sub 5} and from about 25 to about 50 weight percent iron oxide and has metals present in the metal waste chemically dissolved therein. The concentration of iron oxide in the waste form along with a high proportion of the iron in the waste form being present as Fe{sup 3+} provide a waste form exhibiting improved chemical resistance to corrosive attack. A method for preparing the improved iron phosphate waste forms is also provided. 21 figs.

  15. Iron phosphate compositions for containment of hazardous metal waste

    DOE Patents [OSTI]

    Day, Delbert E. (Rolla, MO)

    1998-01-01

    An improved iron phosphate waste form for the vitrification, containment and long-term disposition of hazardous metal waste such as radioactive nuclear waste is provided. The waste form comprises a rigid iron phosphate matrix resulting from the cooling of a melt formed by heating a batch mixture comprising the metal waste and a matrix-forming component. The waste form comprises from about 30 to about 70 weight percent P.sub.2 O.sub.5 and from about 25 to about 50 weight percent iron oxide and has metals present in the metal waste chemically dissolved therein. The concentration of iron oxide in the waste form along with a high proportion of the iron in the waste form being present as Fe.sup.3+ provide a waste form exhibiting improved chemical resistance to corrosive attack. A method for preparing the improved iron phosphate waste forms is also provided.

  16. Reduction and carburization reactions in the iron bath smelter

    SciTech Connect (OSTI)

    Uemura, Kenichiro

    1993-01-01

    Slag-metal-coal reactions in the iron-bath smelter were analyzed based on a reaction model. It was concluded that the productivity and carbon content of the hot metal produced in a smelter can be controlled by adjusting the slag volume and iron oxide content in slag. Furthermore, iron oxide content is determined by the slag volume and the stirring intensity of the slag.

  17. Hepcidin Is Involved in Iron Regulation in the Ischemic Brain

    E-Print Network [OSTI]

    Ding, Hui; Yan, Cai-Zhen; Shi, Honglian; Zhao, Ya-Shuo; Chang, Shi-Yang; Yu, Peng; Wu, Wen_Shuang; Zhao, Chen-Yang; Chang, Yan-Zhong; Duan, Xiang-Lin

    2011-09-21

    : #2; 2011 Ding et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source... an important role in the management of iron metabolism. Accumulated evidence suggests that the transferrin– transferrin receptor (Tf–TfR) pathway might be the major route of iron transport across the luminal membrane of the capillary endothelium and iron uptake...

  18. Iron-titanium-mischmetal alloys for hydrogen storage

    DOE Patents [OSTI]

    Sandrock, Gary Dale (Ringwood, NJ)

    1978-01-01

    A method for the preparation of an iron-titanium-mischmetal alloy which is used for the storage of hydrogen. The alloy is prepared by air-melting an iron charge in a clay-graphite crucible, adding titanium and deoxidizing with mischmetal. The resultant alloy contains less than about 0.1% oxygen and exhibits a capability for hydrogen sorption in less than half the time required by vacuum-melted, iron-titanium alloys.

  19. Iron Corrosion Observations: Pu(VI)-Fe Reduction Studies

    SciTech Connect (OSTI)

    Reed, Donald T. [Los Alamos National Laboratory; Swanson, Juliet S. [Los Alamos National Laboratory; Richmann, Michael K. [Los Alamos National Laboratory; Lucchini, Jean-Francois [Los Alamos National Laboratory; Borkowski, Marian [Los Alamos National Laboratory

    2012-09-11

    Iron and Pu Reduction: (1) Very different appearances in iron reaction products were noted depending on pH, brine and initial iron phase; (2) Plutonium was associated with the Fe phases; (3) Green rust was often noted at the higher pH; (4) XANES established the green rust to be an Fe2/3 phase with a bromide center; and (5) This green rust phase was linked to Pu as Pu(IV).

  20. Vitamin A, Iron, and Anemia: from observation to hypotheses

    E-Print Network [OSTI]

    Miller, Jed

    1998-01-01

    Beynen, A.C. "Supplemental vitamin A enhances the recoveryin rats with chronic vitamin A deficiency." British Journal1996). Thurnham, D.I. "Vitamin A, Iron, and haemopoiesis"

  1. Beyond iron: non-classical biological functions of bacterial siderophores

    E-Print Network [OSTI]

    Nolan, Elizabeth M.

    Bacteria secrete small molecules known as siderophores to acquire iron from their surroundings. For over 60 years, investigations into the bioinorganic chemistry of these molecules, including fundamental coordination ...

  2. Metal regeneration of iron chelates in nitric oxide scrubbing

    DOE Patents [OSTI]

    Chang, S.G.; Littlejohn, D.; Shi, Y.

    1997-08-19

    The present invention relates to a process of using metal particles to reduce NO to NH{sub 3}. More specifically, the invention concerns an improved process to regenerate iron (II) (CHELATE) by reduction of iron (II) (CHELATE) (NO) complex, which process comprises: (a) contacting an aqueous solution containing iron (II) (CHELATE) (NO) with metal particles at between about 20 and 90 C to reduce NO present, produce ammonia or an ammonium ion, and produce free iron (II) (CHELATE) at a pH of between about 3 and 8. The process is useful to remove NO from flue gas and reduce pollution. 34 figs.

  3. Metal regeneration of iron chelates in nitric oxide scrubbing

    DOE Patents [OSTI]

    Chang, Shih-Ger (El Cerrito, CA); Littlejohn, David (Oakland, CA); Shi, Yao (Berkeley, CA)

    1997-08-19

    The present invention relates to a process of using metal particles to reduce NO to NH.sub.3. More specifically, the invention concerns an improved process to regenerate iron (II) (CHELATE) by reduction of iron (II) (CHELATE) (NO) complex, which process comprises: a) contacting an aqueous solution containing iron (II) (CHELATE) (NO) with metal particles at between about 20.degree. and 90.degree. C. to reduce NO present, produce ammonia or an ammonium ion, and produce free iron (II) (CHELATE) at a pH of between about 3 and 8. The process is useful to remove NO from flue gas and reduce pollution.

  4. Effects of dissimilatory sulfate reduction on iron (hydr)oxide...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Effects of dissimilatory sulfate reduction on iron (hydr)oxide reduction and microbial community development May 14, 2014 Tweet EmailPrint Aquatic and terrestrial environments are...

  5. The Fate of Bioavailable Iron in Antarctic Coastal Seas | Advanced...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of iron mirrors the distribution of silicon. Science is exploring many options for carbon dioxide sequestration in order to mitigate the climatological impact of CO2. One of...

  6. Bandwidth Study U.S. Iron and Steel Manufacturing | Department...

    Broader source: Energy.gov (indexed) [DOE]

    (or bandwidth) of potential energy savings opportunities. This bandwidth study examines energy consumption and potential energy savings opportunities in U.S. iron and steel...

  7. Effects of Iron Oxides on the Rheological Properties of Cementitious...

    Office of Scientific and Technical Information (OSTI)

    properties of the cementitious slurry were studied using rheometry and ultrasonic wave reflection to understand the effects of various iron oxides (magnetite, hematite,...

  8. Microstructural Modification of a Cast Iron by Magnetic Field Processing

    SciTech Connect (OSTI)

    Kenik, Edward A [ORNL; Ludtka, Gail Mackiewicz- [ORNL; Ludtka, Gerard Michael [ORNL; Wilgen, John B [ORNL; Kisner, Roger A [ORNL

    2010-01-01

    The current study deals with the microstructural modification of a nodular cast iron during solidification under the influence of high magnetic fields (up to 18 tesla).

  9. MATHEMATICAL MODELING OF THE LITHIUM-ALUMINUM, IRON SULFIDE BATTERY

    E-Print Network [OSTI]

    Pollard, Richard

    2012-01-01

    and J. Newman, Proc. Syrup. Battery Design and Optimization,123, 1364 (1976). Symp, Battery Design and Optimization, S.~ALUMINUM, IRON SULFIDE BATTERY Contents ACKNOWLEDGEMENTS

  10. X-ray tomography system to investigate granular materials during mechanical loading

    SciTech Connect (OSTI)

    Athanassiadis, Athanasios G. [James Franck Institute and Department of Physics, The University of Chicago, Chicago, Illinois 60637 (United States); Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); La Rivière, Patrick J.; Sidky, Emil; Pan, Xiaochuan [Department of Radiology, The University of Chicago, Chicago, Illinois 60637 (United States); Pelizzari, Charles [Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, Illinois 60637 (United States); Jaeger, Heinrich M., E-mail: h-jaeger@uchicago.edu [James Franck Institute and Department of Physics, The University of Chicago, Chicago, Illinois 60637 (United States)

    2014-08-15

    We integrate a small and portable medical x-ray device with mechanical testing equipment to enable in situ, non-invasive measurements of a granular material's response to mechanical loading. We employ an orthopedic C-arm as the x-ray source and detector to image samples mounted in the materials tester. We discuss the design of a custom rotation stage, which allows for sample rotation and tomographic reconstruction under applied compressive stress. We then discuss the calibration of the system for 3D computed tomography, as well as the subsequent image reconstruction process. Using this system to reconstruct packings of 3D-printed particles, we resolve packing features with 0.52?mm resolution in a (60 mm){sup 3} field of view. By analyzing the performance bounds of the system, we demonstrate that the reconstructions exhibit only moderate noise.

  11. Flow rule, self-channelization and levees in unconfined granular flows

    E-Print Network [OSTI]

    S. Deboeuf; E. Lajeunesse; O. Dauchot; B. Andreotti

    2006-10-12

    Unconfined granular flows along an inclined plane are investigated experimentally. During a long transient, the flow gets confined by quasistatic banks but still spreads laterally towards a well-defined asymptotic state following a nontrivial process. Far enough from the banks a scaling for the depth averaged velocity is obtained, which extends the one obtained for homogeneous steady flows. Close to jamming it exhibits a crossover towards a nonlocal rheology. We show that the levees, commonly observed along the sides of the deposit upon interruption of the flow, disappear for long flow durations. We demonstrate that the morphology of the deposit builds up during the flow, in the form of an underlying static layer, which can be deduced from surface velocity profiles, by imposing the same flow rule everywhere in the flow.

  12. Dynamics of Air-Fluidized Granular System Measured by the Modulated Gradient Spin-echo

    E-Print Network [OSTI]

    Janez Stepisnik; Samo Lasic; Igor Sersa; Ales Mohoric; Gorazd Planinsic

    2005-10-05

    The power spectrum of displacement fluctuation of beads in the air-fluidized granular system is measured by a novel NMR technique of modulated gradient spin-echo. The results of measurement together with the related spectrum of the velocity fluctuation autocorrelation function fit well to an empiric formula based on to the model of bead caging between nearest neighbours; the cage breaks up after a few collisions \\cite{Menon1}. The fit yields the characteristic collision time, the size of bead caging and the diffusion-like constant for different degrees of system fluidization. The resulting mean squared displacement increases proportionally to the second power of time in the short-time ballistic regime and increases linearly with time in the long-time diffusion regime as already confirmed by other experiments and simulations.

  13. Power-law rheology and the dynamical heterogeneity in a sheared granular material

    E-Print Network [OSTI]

    Takahiro Hatano

    2008-11-09

    Rheology of a granular material at the jamming density is investigated using molecular dynamics simulation. It is found that shear stress exhibits power-law dependence on shear rate with a nontrivial exponent. Due to the criticality of the jamming transition point, finite-size effect is observed in smaller systems at lower shear rates. Finite-size scaling indicates the correlation length algebraically diverges in the zero shear rate limit. It is also found that the dynamical susceptibility monotonically decreases with time so that the dynamical heterogeneity is detected by a two-point correlation function. Several exponents that describe rheology, the correlation length, and the amplitude of the dynamical susceptibility are estimated.

  14. Universality and criticality of a second-order granular solid-liquid-like phase transition

    E-Print Network [OSTI]

    Gustavo Castillo; Nicolás Mujica; Rodrigo Soto

    2015-01-20

    We experimentally study the critical properties of the non-equilibrium solid-liquid-like transition that takes place in vibrated granular matter. The critical dynamics is characterized by the coupling of the density field with the bond-orientational order parameter $Q_4$, which measures the degree of local crystallization. Two setups are compared, which present the transition at different critical accelerations as a a result of modifying the energy dissipation parameters. In both setups five independent critical exponents are measured, associated to different properties of $Q_4$: the correlation length, relaxation time, vanishing wavenumber limit (static susceptibility), the hydrodynamic regime of the pair correlation function, and the amplitude of the order parameter. The respective critical exponents agree in both setups and are given by $\

  15. Competition of Brazil nut effect, buoyancy, and inelasticity induced segregation in a granular mixture

    E-Print Network [OSTI]

    Ricardo Brito; Rodrigo Soto

    2010-12-21

    It has been recently reported that a granular mixture in which grains differ in their restitution coefficients presents segregation: the more inelastic particles sink to the bottom. When other segregation mechanisms as buoyancy and the Brazil nut effect are present, the inelasticity induced segregation can compete with them. First, a detailed analysis, based on numerical simulations of two dimensional systems, of the competition between buoyancy and the inelasticity induced segregation is presented, finding that there is a transition line in the parameter space that determines which mechanism is dominant. In the case of neutrally buoyant particles having different sizes the inelasticity induced segregation can compete with the Brazil nut effect (BNE). Reverse Brazil nut effect (RBNE) could be obtained at large inelasticities of the intruder. At intermediate values, BNE and RBNE coexist and large inelastic particles are found both near the bottom and at the top of the system.

  16. The structural origin of the hard-sphere glass transition in granular packing

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Xia, Chengjie; Li, Jindong; Cao, Yixin; Kou, Binquan; Xiao, Xianghui; Fezzaa, Kamel; Xiao, Tiqiao; Wang, Yujie

    2015-09-28

    Glass transition is accompanied by a rapid growth of the structural relaxation time and a concomitant decrease of configurational entropy. It remains unclear whether the transition has a thermodynamic origin, and whether the dynamic arrest is associated with the growth of a certain static order. Using granular packing as a model hard-sphere glass, we show the glass transition as a thermodynamic phase transition with a ‘hidden’ polytetrahedral order. This polytetrahedral order is spatially correlated with the slow dynamics. It is geometrically frustrated and has a peculiar fractal dimension. Additionally, as the packing fraction increases, its growth follows an entropy-driven nucleationmore »process, similar to that of the random first-order transition theory. In conclusion, our study essentially identifies a long-sought-after structural glass order in hard-sphere glasses.« less

  17. R&D for a highly granular silicon tungsten electromagnetic calorimeter

    E-Print Network [OSTI]

    Pöschl, R

    2015-01-01

    This article reports on first experience with the technological prototype of a highly- granular silicon-tungsten electromagnetic calorimeter as envisaged for the detectors at a future lepton collider. In the focus of the analysis is the performance of a highly integrated Application Specific Integrated Circuit designed to meet the requirements in terms of dynamic range, compactness and power consumption. The beam test results show that the circuit will allow a future detector with a signal over noise ratio of at least 10:1. To minimise the power dissipation the ASIC will be operated in a power pulsed mode. So far no conceptual problem was revealed but the studies show the way for further work. The prototype is read out by a DAQ system conceived to meet the needs of a trigger less system with a huge number of readout cells.

  18. A Phase Diagram Unifies Energy Dissipation, Kinetics, and Rheology in Inertial Granular Flows

    E-Print Network [OSTI]

    E. DeGiuli; J. N. McElwaine; M. Wyart

    2015-09-11

    Flows of hard granular materials depend strongly on the interparticle friction coefficient $\\mu_p$ and on the inertial number ${\\cal I}$, which characterizes proximity to the jamming transition where flow stops. Guided by numerical simulations, we derive the phase diagram of dense inertial flow of spherical particles, finding three regimes for $10^{-4} \\lesssim {\\cal I} \\lesssim 0.1$: frictionless, frictional sliding, and rolling. These are distinguished by the dominant means of energy dissipation, changing from collisional to sliding friction, and back to collisional, as $\\mu_p$ increases from zero at constant ${\\cal I}$. The three regimes differ in their kinetics and rheology; in particular, the velocity fluctuations and the stress anisotropy both display non-monotonic behavior with $\\mu_p$, corresponding to transitions between the three regimes of flow. We characterize the scaling properties of these regimes, show that energy balance yields scaling relations for each of them, and explain why friction qualitatively affects flow.

  19. Nonlinear Low-to-High Frequency Energy Cascades in Diatomic Granular Crystals

    E-Print Network [OSTI]

    E. Kim; R. Chaunsali; H. Xu; J. Jaworski; J. Yang; P. Kevrekidis; A. F. Vakakis

    2015-08-07

    We study wave propagation in strongly nonlinear 1D diatomic granular crystals under an impact load. Depending on the mass ratio of the `light' to `heavy' beads, this system exhibits rich wave dynamics from highly localized traveling waves to highly dispersive waves featuring strong attenuation. We experimentally demonstrate the nonlinear resonant and anti-resonant interactions of particles and verify that the nonlinear resonance results in strong wave attenuation, leading to highly efficient nonlinear energy cascading without relying on material damping. In this process, mechanical energy is transferred from low to high frequencies, while propagating waves emerge in both ordered and chaotic waveforms via a distinctive spatial cascading. This energy transfer mechanism from lower to higher frequencies and wavenumbers is of particular significance towards the design of novel nonlinear acoustic metamaterials with inherently passive energy redistribution properties.

  20. Method and apparatus for filtering gas with a moving granular filter bed

    DOE Patents [OSTI]

    Brown, Robert C. (Ames, IA); Wistrom, Corey (Ames, IA); Smeenk, Jerod L. (Ames, IA)

    2007-12-18

    A method and apparatus for filtering gas (58) with a moving granular filter bed (48) involves moving a mass of particulate filter material (48) downwardly through a filter compartment (35); tangentially introducing gas into the compartment (54) to move in a cyclonic path downwardly around the moving filter material (48); diverting the cyclonic path (58) to a vertical path (62) to cause the gas to directly interface with the particulate filter material (48); thence causing the gas to move upwardly through the filter material (48) through a screened partition (24, 32) into a static upper compartment (22) of a filter compartment for exodus (56) of the gas which has passed through the particulate filter material (48).

  1. THE ROLE OF FERRIC IRON UPTAKE REGULATOR (FUR) PROTEIN ON IRON REGULATION IN COXIELLA BURNETII 

    E-Print Network [OSTI]

    Wilson, Mary J

    2006-08-16

    in the phagolysosome, an acidic vacuole meant to kill the bacterium, where it survives and replicates. C. burnetii must be able to acquire all the nutrients necessary for survival within this acidic environment. In all but one species of bacteria, iron has been shown...

  2. Enhancing the Performance of the Rechargeable Iron Electrode in Alkaline Batteries with Bismuth Oxide and Iron Sulfide Additives

    SciTech Connect (OSTI)

    Manohar, AK; Yang, CG; Malkhandi, S; Prakash, GKS; Narayanan, SR

    2013-09-07

    Iron-based alkaline rechargeable batteries have the potential of meeting the needs of large-scale electrical energy storage because of their low-cost, robustness and eco-friendliness. However, the widespread commercial deployment of iron-based batteries has been limited by the low charging efficiency and the poor discharge rate capability of the iron electrode. In this study, we have demonstrated iron electrodes containing bismuth oxide and iron sulfide with a charging efficiency of 92% and capable of being discharged at the 3C rate. Such a high value of charging efficiency combined with the ability to discharge at high rates is being reported for the first time. The bismuth oxide additive led to the in situ formation of elemental bismuth and a consequent increase in the overpotential for the hydrogen evolution reaction leading to an increase in the charging efficiency. We observed that the sulfide ions added to the electrolyte and iron sulfide added to the electrode mitigated-electrode passivation and allowed for continuous discharge at high rates. At the 3C discharge rate, a utilization of 0.2 Ah/g was achieved. The performance level of the rechargeable iron electrode demonstrated here is attractive for designing economically-viable large-scale energy storage systems based on alkaline nickel-iron and iron-air batteries. (C) 2013 The Electrochemical Society. All rights reserved.

  3. Lift and drag in intruders moving through hydrostatic granular media at high speeds

    E-Print Network [OSTI]

    Fabricio Q. Potiguar; Yang Ding

    2013-07-18

    Recently, experiments showed that forces on intruders dragged horizontally through dense, hydrostatic granular packings mainly depend on the local surface orientation and can be seen as the sum of the forces exerted on small surface elements. In order to understand such forces more deeply, we perform 2D soft-sphere molecular dynamics simulation, on similar set up, of an intruder dragged through a 50-50 bi-disperse granular packing, with diameters 0.30 and 0.34 cm. We measure, for both circular and half-circle shapes, the forces parallel (drag) and perpendicular (lift) to the drag direction as functions of the drag speed, with V=10.3-309 cm/s, and intruder depths, with D=3.75-37.5 cm. The drag forces on an intruder monotonically increase with V and D, and are larger for the circle. However, the lift force does not depend monotonically on V and D, and this relationship is affected by the shape of the intruder. The vertical force was negative for the half-circle, but for a small range of V and D, we measure positive lift. We find no sign change for the lift on the circle, which is always positive. The explanation for the nonmonotonic dependence is related to the decrease in contacts on the intruder as V increases. This is qualitatively similar to supersonic flow detachment from an obstacle. The detachment picture is supported by simulation measurements of the velocity field around the intruder and force profiles measured on its surface.

  4. Friction and Pressure-Dependence of Force Chain Communities in Granular Materials

    E-Print Network [OSTI]

    Yuming Huang; Karen E. Daniels

    2015-08-23

    Granular materials transmit stress via a network of force chains. Despite the importance of these chains to characterizing the stress state and dynamics of the system, there is no common framework for quantifying their their properties. Recently, attention has turned to the tools of network science as a promising route to such a description. In this paper, we apply community detection techniques to numerically-generated packings of spheres over a range of interparticle friction coefficients and confining pressures. In order to extract chain-like features, we use a modularity maximization with a recently-developed geographical null model \\cite{Bassett2015}, and optimize the technique to detect branched structures by minimizing the normalized convex hull of the detected communities. We characterize the force chain communities by their size (number of particles), network strength (internal forces), and normalized convex hull ratio (sparseness). We find the that the first two exhibit an approximately linear correlation and are therefore largely redundant. For both pressure $P$ and interparticle friction $\\mu$, we observe crossovers in behavior. For $\\mu \\lesssim 0.1$, the packings exhibit more sensitivity to pressure. In addition, we identify a crossover pressure where the frictional dependence switches from having more large/strong communities at low $\\mu$ vs. high $\\mu$. We explain these phenomena by comparison to the spatial distribution of communities along the vertical axis of the system. These results provide new tools for considering the mesoscale structure of a granular system and pave the way for reduced descriptions based on the force chain structure.

  5. Improved granular activated carbon for the stabilization of wastewater pH

    SciTech Connect (OSTI)

    NONE

    1996-10-01

    Many times the start up of granular activated carbon adsorption systems for the control of organic contaminants in wastewater cm exhibit unacceptable increases in the adscurber effluent pH. Experience shows that the duration of the pH increase ranges from several hours to several days, during which time several hundred bed volumes of water can be discharged with a pH in excess of 9. Laboratory studies have identified the cause of the pH rise as an interaction between the naturally occurring anions and protons ar the water and the carbon surface. The interaction can be described as an ion exchange type of phenomenon, in which the carbon surface sorbs the anions and corresponding hydronium ions from the water. Capacities of the carbon for the anions range from 2 to 9 mg/g GAC, depending upon the water characteristics, the carbon type, the nature of the anion and its influent concentration. These studies have shown de the anion sorption and resulting pH increase is independent of the raw material used for die activated carbon production, e.g. bituminous or sub-bituminous coal, peat, wood or coconut. Also, the pH excursions occur with virgin, reactivated, and acid washed granular carbons. Current pH control technologies focus on adjustment of wastewater pH prior to discharge or recycle of the initial effluent water until the pH increase abates. However, improved water pH control options have been realized by altering the carbon surface rather than the water chemistry. The change to the carbon surface is accomplished through a controlled oxidation process. This process provides a more acidic carbon surface with a reduced affinity for the anions in the waste water. As a result, the pH excursions above 9 are eliminated and the initial effluent from the adsorption system can be discharged without further treatment.

  6. Arsenic remediation of drinking water using iron-oxide coated coal bottom ash

    E-Print Network [OSTI]

    MATHIEU, JOHANNA L.

    2010-01-01

    using Iron-oxide Coated Coal Ash. In Arsenic Contaminationwater using  iron?oxide coated coal bottom ash  Johanna L.  using iron-oxide coated coal bottom ash JOHANNA L. MATHIEU

  7. Public good dynamics drive evolution of iron acquisition strategies in natural bacterioplankton populations

    E-Print Network [OSTI]

    Cordero Sanchez, Otto Xavier

    A common strategy among microbes living in iron-limited environments is the secretion of siderophores, which can bind poorly soluble iron and make it available to cells via active transport mechanisms. Such siderophore–iron ...

  8. Cooperation, the Craft Economy, and Metal Technology during the Bronze and Iron Ages in Central Anatolia

    E-Print Network [OSTI]

    Lehner, Joseph William

    2015-01-01

    of Iron Age copper production (including extraction mining,and Mining in Eastern Anatolia in the Urartian Period: Silver, Copper and Iron.mining district of the central Taurus and immediately north of Cilicia includes mostly iron,

  9. Electrically insulating phosphate coatings for iron powder based electromagnetic core applications

    E-Print Network [OSTI]

    Nolan, William Rane

    2009-01-01

    Powdered metals, such as iron, are a common building block for electromagnetic cores. An iron powder was reacted with phosphoric acid to create a layer of iron phosphate on each particle. This electrically insulating ...

  10. Suspension Hydrogen Reduction of Iron Oxide Concentrates

    SciTech Connect (OSTI)

    H.Y. Sohn

    2008-03-31

    The objective of the project is to develop a new ironmaking technology based on hydrogen and fine iron oxide concentrates in a suspension reduction process. The ultimate objective of the new technology is to replace the blast furnace and to drastically reduce CO2 emissions in the steel industry. The goals of this phase of development are; the performance of detailed material and energy balances, thermochemical and equilibrium calculations for sulfur and phosphorus impurities, the determination of the complete kinetics of hydrogen reduction and bench-scale testing of the suspension reduction process using a large laboratory flash reactor.

  11. Iron and Manganese in Potable Water

    E-Print Network [OSTI]

    Young, Clifford Caudy

    1911-06-01

    and wash once or twice Toy decantation; dissolve the Iron in the same beaker in wViich original precipitation was made and re-precipitate with UH4 OH. Care should he taken to have plenty of ammonium salts present. The second precipitation is fil­ tered... nitrate solution containing two grams of the salt per liter. Lead Peroxide Method. The reaction employed in this method is that known a3 the Volhard Treadwell reaction. Sufficient quantity of the water to yield one-tenth to one milligram of Manganese...

  12. Kumba Iron Ore | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History View NewTexas: EnergyKulpsville, Pennsylvania: Energy Resources Jump to: navigation,Kumba Iron Ore

  13. Iron Availability in the Southern Ocean

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACT EVALUATIONIntroducing the RichardBudgetIowaOctoberNovember 3,Iron

  14. Iron Availability in the Southern Ocean

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACT EVALUATIONIntroducing the RichardBudgetIowaOctoberNovemberIron

  15. Iron Availability in the Southern Ocean

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation CurrentHenryInhibitingInteractivePGAS andUniversity Ion BeamsIraIron

  16. Electron Correlation in Iron-Based Superconductors

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submitKansas Nuclear ProfileMultiferroicAward |Electron Correlation in Iron-Based

  17. Rare Iron Oxide in Ancient Chinese Pottery

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservation of Fe(II) by Carbon-RichProton DeliveryRadioactiveRare Iron Oxide in Ancient

  18. Mechanisms of Selenate Adsorption on Iron Oxides and Hydroxides

    E-Print Network [OSTI]

    Sparks, Donald L.

    Mechanisms of Selenate Adsorption on Iron Oxides and Hydroxides D . P E A K * A N D D . L . S P A R are important sorbents for SeO4 2- in soils and sediments, but the mechanism of selenate adsorption on iron- bonding mechanisms on hematite, goethite, and hydrous ferric oxide (HFO). It was learned that selenate

  19. OBSERVATIONS OF THE EFFECT OF ACID-IRON

    E-Print Network [OSTI]

    OBSERVATIONS OF THE EFFECT OF ACID-IRON WASTE DISPOSAL AT SEA ON ANIMAL POPULATIONS tj^iitinn p AND WILDLIFE SERVICE #12;#12;OBSERVATIONS OF THE EFFECT OF ACID-IRON WASTE DISPOSAL AT SEA ON ANIMAL scope, intended to aid or direct management or utilization practices and as guides for administrative

  20. Next Generation Metallic Iron Nodule Technology in Electric Furnace Steelmaking

    Broader source: Energy.gov [DOE]

    This factsheet describes a research project whose objective is to investigate reducing processing temperature, controlling the gas temperature and gas atmosphere over metalized iron nodules, and effectively using sub-bituminous coal as a reductant for producing high quality metalized iron nodules at low cost.

  1. Octadecylphosphonate (ODP) for corrosion inhibition of iron using

    E-Print Network [OSTI]

    Petta, Jason

    Octadecylphosphonate (ODP) for corrosion inhibition of iron using the T-BAG technique Tiffany V of corrosion include pipelines, mining facilities, oil and gas production sites, marine ships, hazmat storage), and electrochemical impedance spectroscopy (EIS). #12;Corrosion of iron in contact with water Overall Reaction: 4Fe

  2. MATHEMATICAL MODELING OF THE LITHIUM-ALUMINUM, IRON SULFIDE BATTERY. I. GALVONOSTATIC DISCHARGE BEHAVIOR

    E-Print Network [OSTI]

    Pollard, Richard

    2012-01-01

    composition profiles in lithium/sulfur battery analogues hasTHE LITHIUM-ALUMINUM, IRON SULFIDE BATTERY. I. GALVONOSTATICthe Lithium-Aluminum, Iron Sulfide Battery I. Galvanostatic

  3. Mechanisms controlling dissolved iron distribution in the North Pacific: A model study

    E-Print Network [OSTI]

    2011-01-01

    iron transport off the coast of California. 5. Conclusion [the coast of California. Detailed transport processes differcoast of California (Figure 11). Offshore iron transport by

  4. Electrochemical Deposition of Iron Nanoneedles on Titanium Oxide Nanotubes

    SciTech Connect (OSTI)

    Gan Y. X.; Zhang L.; Gan B.J.

    2011-10-01

    Iron as a catalyst has wide applications for hydrogen generation from ammonia, photodecomposition of organics, and carbon nanotube growth. Tuning the size and shape of iron is meaningful for improving the catalysis efficiency. It is the objective of this work to prepare nanostructured iron with high surface area via electrochemical deposition. Iron nanoneedles were successfully electrodeposited on Ti supported TiO2 nanotube arrays in a chlorine-based electrolyte containing 0.15 M FeCl2 {center_dot} 4H2O and 2.0 M HCl. Transmission electron microscopic analysis reveals that the average length of the nanoneedles is about 200 nm and the thickness is about 10 nm. It has been found that a high overpotential at the cathode made of Ti/TiO2 nanotube arrays is necessary for the formation of the nanoneedles. Cyclic voltammetry test indicates that the electrodeposition of iron nanoneedles is a concentration-limited process.

  5. System and method for producing metallic iron nodules

    DOE Patents [OSTI]

    Bleifuss, Rodney L. (Grand Rapids, MN); Englund, David J. (Bovey, MN); Iwasaki, Iwao (Grand Rapids, MN); Lindgren, Andrew J. (Grand Rapids, MN); Kiesel, Richard F. (Hibbing, MN)

    2011-09-20

    A method for producing metallic iron nodules by assembling a shielding entry system to introduce coarse carbonaceous material greater than 6 mesh in to the furnace atmosphere at location(s) where the temperature of the furnace atmosphere adjacent at least partially reduced reducible iron bearing material is between about 2200 and 2650.degree. F. (1200 and 1450.degree. C.), the shielding entry system adapted to inhibit emission of infrared radiation from the furnace atmosphere and seal the furnace atmosphere from exterior atmosphere while introducing coarse carbonaceous material greater than 6 mesh into the furnace to be distributed over the at least partially reduced reducible iron bearing material, and heating the covered at least partially reduced reducible iron bearing material in a fusion atmosphere to assist in fusion and inhibit reoxidation of the reduced material during fusion to assist in fusion and inhibit reoxidation of the reduced material in forming metallic iron nodules.

  6. FeCycle: Attempting an iron biogeochemical budget from a mesoscale SF6 tracer experiment in unperturbed low iron waters

    E-Print Network [OSTI]

    Wilhelm, Steven W.

    FeCycle: Attempting an iron biogeochemical budget from a mesoscale SF6 tracer experiment to ocean physics. In summer 2003 we conducted FeCycle, a 10-day mesoscale tracer release in HNLC waters SE biogeochemical budget from a mesoscale SF6 tracer experiment in unperturbed low iron waters, Global Biogeochem

  7. Selective dissolution of magnetic iron oxides in the acidammonium oxalate/ferrous iron extraction method--I. Synthetic samples

    E-Print Network [OSTI]

    Utrecht, Universiteit

    (AAO) method, in which Fe2+ is added to the extraction solution prior to the experiment [the AAO-Fe(II) method]. The procedure was divided into several 30 min extraction steps to check the dissolution progressSelective dissolution of magnetic iron oxides in the acid­ammonium oxalate/ferrous iron extraction

  8. Laser-Doppler acoustic probing of granular media with in-depth property gradient and varying pore pressures

    SciTech Connect (OSTI)

    Bodet, L.; Dhemaied, A.; Mourgues, R.; Tournat, V.; Rejiba, F.

    2012-05-24

    Non-contacting ultrasonic techniques recently proved to be efficient in the physical modeling of seismic-wave propagation at various application scales, as for instance in the context of geological analogue and seismic modeling. An innovative experimental set-up is proposed here to perform laser-Doppler acoustic probing of unconsolidated granular media with varying pore pressures. The preliminary experiments presented here provide reproducible results and exploitable data, thus validating both the proposed medium preparation and pressure gradient generation procedure.

  9. Role of material properties and mesostructure on dynamic deformation and shear instability in Al-W granular composites

    E-Print Network [OSTI]

    K. L. Olney; P. H. Chiu; C. W. Lee; V. F. Nesterenko; D. J. Benson

    2011-05-24

    Dynamic experiments with Al-W granular/porous composites revealed qualitatively different behavior with respect to shear localization depending on bonding between Al particles. Two-dimensional numerical modeling was used to explore the mesomechanics of the large strain dynamic deformation in Al-W granular/porous composites and explain the experimentally observed differences in shear localization between composites with various mesostructures. Specifically, the bonding between the Al particles, the porosity, the roles of the relative particle sizes of Al and W, the arrangements of the W particles, and the material properties of Al were investigated using numerical calculations. It was demonstrated in simulations that the bonding between the "soft" Al particles facilitated shear localization as seen in the experiments. Numerical calculations and experiments revealed that the mechanism of the shear localization in granular composites is mainly due to the local high strain flow of "soft" Al around the "rigid" W particles causing localized damage accumulation and subsequent growth of the meso/macro shear bands/cracks. The "rigid" W particles were the major geometrical factor determining the initiation and propagation of "kinked" shear bands in the matrix of "soft" Al particles, leaving some areas free of extensive plastic deformation as observed in experiments and numerical calculations.

  10. Theoretical Investigation of Hydrogen Adsorption and Dissociation on Iron and Iron Carbide Surfaces Using the ReaxFF Reactive Force Field Method

    SciTech Connect (OSTI)

    Zou, Chenyu; van Duin, Adri C.T.; Sorescu, Dan C.

    2012-06-01

    We have developed a ReaxFF reactive force field to describe hydrogen adsorption and dissociation on iron and iron carbide surfaces relevant for simulation of Fischer–Tropsch (FT) synthesis on iron catalysts. This force field enables large system (>>1000 atoms) simulations of hydrogen related reactions with iron. The ReaxFF force field parameters are trained against a substantial amount of structural and energetic data including the equations of state and heats of formation of iron and iron carbide related materials, as well as hydrogen interaction with iron surfaces and different phases of bulk iron. We have validated the accuracy and applicability of ReaxFF force field by carrying out molecular dynamics simulations of hydrogen adsorption, dissociation and recombination on iron and iron carbide surfaces. The barriers and reaction energies for molecular dissociation on these two types of surfaces have been compared and the effect of subsurface carbon on hydrogen interaction with iron surface is evaluated. We found that existence of carbon atoms at subsurface iron sites tends to increase the hydrogen dissociation energy barrier on the surface, and also makes the corresponding hydrogen dissociative state relatively more stable compared to that on bare iron. These properties of iron carbide will affect the dissociation rate of H{sub 2} and will retain more surface hydride species, thus influencing the dynamics of the FT synthesis process.

  11. Experimental Investigation of Iron Plasma Opacity Models

    SciTech Connect (OSTI)

    Bailey, J. E.; Rochau, G. A.; Hansen, S. B.; Nash, T. J.; Nielsen, D. S.; Lake, P. W. [Sandia National Laboratories, Albuquerque, N.M., 87185-1196 (United States); Iglesias, C. A. [University of California, Lawrence Livermore National Laboratory, Livermore, CA, 94550 (United States); Mancini, R. C. [University of Nevada, Reno, NV (United States); MacFarlane, J. J.; Golovkin, I.; Wang, P. [Prism Computational Sciences, Madison, WI (United States); Blancard, C.; Cosse, Ph.; Faussurier, G.; Gilleron, F.; Pain, J. C. [CEA, DAM, DIF, F-91297 Arpajon (France); Abdallah, J. Jr. [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico, 87545 (United States); Pradhan, A. K.; Nahar, S. N. [Dept. of Astronomy, The Ohio State University, Columbus, Ohio, 43210 (United States)

    2009-09-10

    Recent experiments extended iron opacity model tests to temperatures above 150 eV for the first time. The experiments use the Z Facility to volumetrically heat a CH-tamped Fe/Mg plasma using x-rays. The frequency dependent sample transmission is measured by viewing a backlight through the sample. The plasma conditions are inferred from the Mg K-shell absorption. The strategy for this research is to examine the underlying physics within Fe opacity models by comparisons with the measured transmission. Physics topics of interest include charge state distribution, energy level structure, and line broadening. In this talk we discuss methods to exploit the data and advance understanding for these topics. In addition, we review new experiments under way to further improve the data and to achieve higher energy density conditions.

  12. System and method for producing metallic iron

    DOE Patents [OSTI]

    Bleifuss, Rodney L; Englund, David J; Iwasaki, Iwao; Fosnacht, Donald R; Brandon, Mark M; True, Bradford G

    2013-09-17

    A hearth furnace for producing metallic iron material has a furnace housing having a drying/preheat zone, a conversion zone, a fusion zone, and optionally a cooling zone, the conversion zone is between the drying/preheat zone and the fusion zone. A moving hearth is positioned within the furnace housing. A hood or separation barrier within at least a portion of the conversion zone, fusion zone or both separates the fusion zone into an upper region and a lower region with the lower region adjacent the hearth and the upper region adjacent the lower region and spaced from the hearth. An injector introduces a gaseous reductant into the lower region adjacent the hearth. A combustion region may be formed above the hood or separation barrier.

  13. Predict carbonation rate on iron catalyst

    SciTech Connect (OSTI)

    Dry, M.E.

    1980-02-01

    On solely thermodynamic grounds, the main hydrocarbon product of the Fischer-Tropsch reaction should be methane; in practice, however, carbon is frequently produced as well and deposited on the iron catalyst, fouling the active surface sites. South African Coal, Oil and Gas Corp., Ltd.'s experiments with a fluidized Fischer-Tropsch catalyst bed demonstrate that the rate of carbon deposition is strongly dependent on the hydrogen partial pressure in the reactor, much less dependent on the CO pressure, and not affected at all by the pressure of CO/sub 2/. A suggested reaction scheme for the Fischer-Tropsch synthesis explains these observations and provides a basis for a correlation useful in predicting carbon-deposition rates.

  14. Multiple hearth furnace for reducing iron oxide

    DOE Patents [OSTI]

    Brandon, Mark M. (Charlotte, NC); True, Bradford G. (Charlotte, NC)

    2012-03-13

    A multiple moving hearth furnace (10) having a furnace housing (11) with at least two moving hearths (20) positioned laterally within the furnace housing, the hearths moving in opposite directions and each moving hearth (20) capable of being charged with at least one layer of iron oxide and carbon bearing material at one end, and being capable of discharging reduced material at the other end. A heat insulating partition (92) is positioned between adjacent moving hearths of at least portions of the conversion zones (13), and is capable of communicating gases between the atmospheres of the conversion zones of adjacent moving hearths. A drying/preheat zone (12), a conversion zone (13), and optionally a cooling zone (15) are sequentially positioned along each moving hearth (30) in the furnace housing (11).

  15. System and method for producing metallic iron

    DOE Patents [OSTI]

    Bleifuss, Rodney L. (Grand Rapids, MN); Englund, David J. (Bovey, MN); Iwasaki, Iwao (Grand Rapids, MN); Fosnacht, Donald R. (Hermantown, MN); Brandon, Mark M. (Charlotte, NC); True, Bradford G. (Charlotte, NC)

    2012-01-17

    A hearth furnace 10 for producing metallic iron material has a furnace housing 11 having a drying/preheat zone 12, a conversion zone 13, a fusion zone 14, and optionally a cooling zone 15, the conversion zone 13 is between the drying/preheat zone 12 and the fusion zone 14. A moving hearth 20 is positioned within the furnace housing 11. A hood or separation barrier 30 within at least a portion of the conversion zone 13, fusion zone 14 or both separates the fusion zone 14 into an upper region and a lower region with the lower region adjacent the hearth 20 and the upper region adjacent the lower region and spaced from the hearth 20. An injector introduces a gaseous reductant into the lower region adjacent the hearth 20. A combustion region may be formed above the hood or separation barrier.

  16. RUSTY OLD STARS: A SOURCE OF THE MISSING INTERSTELLAR IRON?

    SciTech Connect (OSTI)

    McDonald, I.; Zijlstra, A. A.; Markwick, A. J. [Jodrell Bank Centre for Astrophysics, Alan Turing Building, Manchester, M13 9PL (United Kingdom); Sloan, G. C.; Bernard-Salas, J. [Cornell University, Astronomy Department, Ithaca, NY 14853-6801 (United States); Matsunaga, N. [Institute of Astronomy, University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan); Matsuura, M. [UCL-Institute of Origins, Astrophysics Group, Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Kraemer, K. E., E-mail: iain.mcdonald-2@jb.man.ac.u, E-mail: albert.zijlstra@manchester.ac.u, E-mail: andrew.markwick@manchester.ac.u, E-mail: sloan@isc.astro.cornell.ed, E-mail: matsunaga@ioa.s.u-tokyo.ac.j, E-mail: mikako@star.ucl.ac.u [Air Force Research Laboratory, Space Vehicles Directorate, Hanscom AFB, MA 01731 (United States)

    2010-07-10

    Iron, the universe's most abundant refractory element, is highly depleted in both circumstellar and interstellar environments, meaning it exists in solid form. The nature of this solid is unknown. In this Letter, we provide evidence that metallic iron grains are present around oxygen-rich asymptotic giant branch stars, where it is observationally manifest as a featureless mid-infrared excess. This identification is made using Spitzer Space Telescope observations of evolved globular cluster stars, where iron dust production appears ubiquitous and in some cases can be modeled as the only observed dust product. In this context, FeO is examined as the likely carrier for the 20 {mu}m feature observed in some of these stars. Metallic iron appears to be an important part of the dust condensation sequence at low metallicity, and subsequently plays an influential role in the interstellar medium. We explore the stellar metallicities and luminosities at which iron formation is observed, and how the presence of iron affects the outflow and its chemistry. The conditions under which iron can provide sufficient opacity to drive a wind remain unclear.

  17. Spall behavior of cast iron with varying microstructures

    SciTech Connect (OSTI)

    Plume, Gifford; Rousseau, Carl-Ernst, E-mail: rousseau@uri.edu [Mechanical Engineering, University of Rhode Island, 92 Upper College Rd., Kingston, Rhode Island 02881 (United States)

    2014-07-21

    The spall strength of cast iron with varying microstructures has been investigated using plate impact at moderate speed. Stress history measurements were made with manganin stress gauges embedded between the back face of the specimen and a low impedance polycarbonate backing. Five separate cast irons were tested. Four of these consisted of gray cast iron with graphite in flake form, with three classified as Type VII A2 and the fourth containing a bimodal distribution of Types VII A4 and VII D8. The fifth casting consisted of ductile cast iron with graphite in nodular form, classified as Type I, size class 5. The spall strength for the Type VII A2 gray cast irons varied between 40 and 370?MPa, and that of the additional gray cast iron, between 410 and 490?MPa. The spall strength of the ductile cast iron fell within the range of 0.94–1.2?GPa. It is shown that the spall strength is linked to the damage level at the spall plane, where an increased level of tensile stress is required to generate higher levels of damage. Post mortem analysis was performed on the recovered samples, revealing the graphite phase to be the primary factor governing the spall fracture of cast irons, where crack nucleation is directly correlated to the debonding of graphite from the metal matrix. The average length of graphite found within a casting is linked to the material's strength, where strength increases as a function of decreasing length. The morphology and mean free path of graphite precipitates further govern the subsequent coalescence of initiated cracks to form a complete fracture plane. In cases where graphite spacing is large, increased energy level is required to complete the fracture process. A secondary factor governing the spall fracture of cast irons has also been linked to the microstructure of the metal matrix, with pearlite yielding higher spall strengths than free ferrite.

  18. Iron is the Key to Preserving Dinosaur Soft Tissue

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACT EVALUATIONIntroducing the RichardBudgetIowaOctoberNovemberIronIronIron

  19. Effects of 12 metal ions on iron regulatory protein 1 (IRP-1...

    Office of Scientific and Technical Information (OSTI)

    FERRITIN; GENES; HOMEOSTASIS; HYDROXYLASES; INHIBITION; IRON; LIGASES; LUCIFERASE; LUNGS; METALLOTHIONEIN; OCCUPATIONAL EXPOSURE; RESPIRATORY TRACT CELLS; STABILIZATION;...

  20. Wintertime pytoplankton bloom in the Subarctic Pacific supported by continental margin iron

    E-Print Network [OSTI]

    Lam, Phoebe J.; Bishop, James K.B.; Henning, Cara C.; Marcus, Matthew A.; Waychunas, Glenn A.; Fung, Inez

    2008-01-01

    of iron hydroxide (60% goethite) and amorphous irona linear combination of goethite (60%) and ferrihydrite (

  1. Stages of destruction and elastic compression of granular nanoporous carbon medium at high pressures

    E-Print Network [OSTI]

    I. M. Neklyudov; O. P. Ledenyov; N. B. Bobrova; A. A. Chupikov

    2015-05-14

    The granular nanoporous carbon medium, made of the cylindrical coal granules of the adsorbent of SKT 3, at an influence by the high pressures from 1MPa to 3GPa has been researched. The eight consecutive stages of the materials specific volume change, which is characterized by a certain dependence of the volume change on the pressure change, have been registered. It is shown that there is a linear dependence on the double log log plot of the materials specific volume change on the pressure for an every stage of considered process. The two stages are clearly distinguished such as a stage of materials mechanical destruction, and a stage of elastic compression of material without the disintegration of structure at a nanscale. The hysteresis dependence of the materials specific volume change on the pressure change at the pressure decrease is observed. The small disperse coal dust particles jettisoning between the high pressure cell and the base plate was observed, resulting in the elastic stress reduction in relation to the small disperse coal dust particles volume. The obtained research data can be used to improve the designs of air filters for the radioactive chemical elements absorption at the NPP with the aims to protect the environment.

  2. Poroelastic measurement schemes resulting in complete data sets for granular and other anisotropic porous media

    SciTech Connect (OSTI)

    Berryman, J.G.

    2009-11-20

    Poroelastic analysis usually progresses from assumed knowledge of dry or drained porous media to the predicted behavior of fluid-saturated and undrained porous media. Unfortunately, the experimental situation is often incompatible with these assumptions, especially when field data (from hydrological or oil/gas reservoirs) are involved. The present work considers several different experimental scenarios typified by one in which a set of undrained poroelastic (stiffness) constants has been measured using either ultrasound or seismic wave analysis, while some or all of the dry or drained constants are normally unknown. Drained constants for such a poroelastic system can be deduced for isotropic systems from available data if a complete set of undrained compliance data for the principal stresses are available - together with a few other commonly measured quantities such as porosity, fluid bulk modulus, and grain bulk modulus. Similar results are also developed here for anisotropic systems having up to orthotropic symmetry if the system is granular (i.e., composed of solid grains assembled into a solid matrix, either by a cementation process or by applied stress) and the grains are known to be elastically homogeneous. Finally, the analysis is also fully developed for anisotropic systems with nonhomogeneous (more than one mineral type), but still isotropic, grains - as well as for uniform collections of anisotropic grains as long as their axes of symmetry are either perfectly aligned or perfectly random.

  3. Time-Periodic Solutions of Driven-Damped Trimer Granular Crystals

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Charalampidis, E. G.; Li, F.; Chong, C.; Yang, J.; Kevrekidis, P. G.

    2015-01-01

    We consider time-periodic structures of granular crystals consisting of alternate chrome steel (S) and tungsten carbide (W) spherical particles where each unit cell follows the pattern of a 2?:?1 trimer: S-W-S. The configuration at the left boundary is driven by a harmonic in-time actuation with given amplitude and frequency while the right one is a fixed wall. Similar to the case of a dimer chain, the combination of dissipation, driving of the boundary, and intrinsic nonlinearity leads to complex dynamics. For fixed driving frequencies in each of the spectral gaps, we find that the nonlinear surface modes and the statesmore »dictated by the linear drive collide in a saddle-node bifurcation as the driving amplitude is increased, beyond which the dynamics of the system becomes chaotic. While the bifurcation structure is similar for solutions within the first and second gap, those in the first gap appear to be less robust. We also conduct a continuation in driving frequency, where it is apparent that the nonlinearity of the system results in a complex bifurcation diagram, involving an intricate set of loops of branches, especially within the spectral gap. The theoretical findings are qualitatively corroborated by the experimental full-field visualization of the time-periodic structures.« less

  4. The Role of Contact Angle Hysteresis for Fluid Transport in Wet Granular Matter

    E-Print Network [OSTI]

    Roman Mani; Ciro Semprebon; Dirk Kadau; Hans J. Herrmann; Martin Brinkmann; Stephan Herminghaus

    2015-08-06

    The stability of sand castles is determined by the structure of wet granulates. Experimental data about the size distribution of fluid pockets are ambiguous about their origin. We discovered that contact angle hysteresis plays a fundamental role in the equilibrium distribution of bridge volumes, and not geometrical disorder as commonly conjectured, which has substantial consequences on the mechanical properties of wet granular beds, including a history dependent rheology and lowered strength. Our findings are obtained using a novel model where the Laplace pressures, bridge volumes and contact angles are dynamical variables associated to the contact points. While accounting for contact line pinning, we track the temporal evolution of each bridge. We observe a cross-over to a power-law decay of the variance of capillary pressures at late times and a saturation of the variance of bridge volumes to a finite value connected to contact line pinning. Large scale simulations of liquid transport in the bridge network reveal that the equilibration dynamics at early times is well described by a mean field model. The spread of final bridge volumes can be directly related to the magnitude of contact angle hysteresis.

  5. Average balance equations, scale dependence, and energy cascade for granular materials

    E-Print Network [OSTI]

    Riccardo Artoni; Patrick Richard

    2015-03-09

    A new averaging method linking discrete to continuum variables of granular materials is developed and used to derive average balance equations. Its novelty lies in the choice of the decomposition between mean values and fluctuations of properties which takes into account the effect of gradients. Thanks to a local homogeneity hypothesis, whose validity is discussed, simplified balance equations are obtained. This original approach solves the problem of dependence of some variables on the size of the averaging domain obtained in previous approaches which can lead to huge relative errors (several hundred percentages). It also clearly separates affine and nonaffine fields in the balance equations. The resulting energy cascade picture is discussed, with a particular focus on unidirectional steady and fully developed flows for which it appears that the contact terms are dissipated locally unlike the kinetic terms which contribute to a nonlocal balance. Application of the method is demonstrated in the determination of the macroscopic properties such as volume fraction, velocity, stress, and energy of a simple shear flow, where the discrete results are generated by means of discrete particle simulation.

  6. Adsorption of selected pharmaceuticals and an endocrine disrupting compound by granular activated carbon. 2. Model prediction

    SciTech Connect (OSTI)

    Yu, Z.; Peldszus, S.; Huck, P.M. [University of Waterloo, Waterloo, ON (Canada). NSERC Chair in Water Treatment

    2009-03-01

    The adsorption of two representative pharmaceutically active compounds (PhACs) naproxen and carbamazepine and one endocrine disrupting compound (EDC) nonylphenol was studied in pilot-scale granular activated carbon (GAC) adsorbers using post-sedimentation (PS) water from a full-scale drinking water treatment plant. The GAC adsorbents were coal-based Calgon Filtrasorb 400 and coconut shell-based PICA CTIF TE. Acidic naproxen broke through fastest while nonylphenol was removed best, which was consistent with the degree to which fouling affected compound removals. Model predictions and experimental data were generally in good agreement for all three compounds, which demonstrated the effectiveness and robustness of the pore and surface diffusion model (PSDM) used in combination with the time-variable parameter approach for predicting removals at environmentally relevant concentrations (i.e., ng/L range). Sensitivity analyses suggested that accurate determination of film diffusion coefficients was critical for predicting breakthrough for naproxen and carbamazepine, in particular when high removals are targeted. Model simulations demonstrated that GAC carbon usage rates (CURs) for naproxen were substantially influenced by the empty bed contact time (EBCT) at the investigated conditions. Model-based comparisons between GAC CURs and minimum CURs for powdered activated carbon (PAC) applications suggested that PAC would be most appropriate for achieving 90% removal of naproxen, whereas GAC would be more suitable for nonylphenol. 25 refs., 4 figs., 1 tab.

  7. Micro-macro transition and simplified contact models for wet granular materials

    E-Print Network [OSTI]

    Sudeshna Roy; Abhinendra Singh; Stefan Luding; Thomas Weinhart

    2015-06-21

    Wet granular materials in a quasi-static steady state shear flow have been studied with discrete particle simulations. Macroscopic quantities, consistent with the conservation laws of continuum theory, are obtained by time averaging and spatial coarse-graining. Initial studies involve understanding the effect of liquid content and liquid properties like the surface tension on the macroscopic quantities. Two parameters of the liquid bridge contact model have been studied as the constitutive parameters that define the structure of this model (i) the rupture distance of the liquid bridge model, which is proportional to the liquid content, and (ii) the maximum adhesive force, as controlled by the surface tension of the liquid. Subsequently a correlation is developed between these micro parameters and the steady state cohesion in the limit of zero confining pressure. Furthermore, as second result, the macroscopic torque measured at the walls, which is an experimentally accessible parameter, is predicted from our simulation results as a dependence on the micro-parameters. Finally, the steady state cohesion of a realistic non-linear liquid bridge contact model scales well with the steady state cohesion for a simpler linearized irreversible contact model with the same maximum adhesive force and equal energy dissipated per contact.

  8. Discrete element modelling of iron ore pellets to include the effects of moisture and fines 

    E-Print Network [OSTI]

    Morrissey, John Paul

    2013-11-28

    Across industry the majority of raw materials handled are particulate in nature, ranging in size and properties from aggregates to powders. The stress regimes experienced by the granular solids vary and the exhibited ...

  9. Modernization of the iron making plant at SOLLAC FOS

    SciTech Connect (OSTI)

    Crayelynghe, M. van; Dufour, A.; Soland, J.; Feret, J.; Lebonvallet, J.

    1995-12-01

    When the blast furnaces at SOLLAC/FOS were relined, the objective being to ensure a worklife of 15 years, it was decided that the iron making plant would be modernized at the same time: the coking plant has been overhauled and renovated and its coking time increased to ensure a worklife of at least 34 years. The surface area of the sinter strand was increased from 400 to 520 m{sup 2}, the burden preparation circuit were simplified, and pig iron production capacity increased from 4.2 to 4.5 million metric tons per year. Coal injection was developed so as to obtain 170 kg/t of pig iron, an expert system was added to ensure more efficient blast furnace operation, and new measures have been carried out for environmental protection. Since these heavy investments have been completed, SOLLAC/FOS is a high-performance iron making plant, allowing it to face new challenges in the future.

  10. Iron-oxide catalyzed silicon photoanode for water splitting

    E-Print Network [OSTI]

    Jun, Kimin

    2011-01-01

    This thesis presents an integrated study of high efficiency photoanodes for water splitting using silicon and iron-oxide. The fundamental limitations of silicon to water splitting applications were overcome by an ultrathin ...

  11. Energy intensity in China's iron and steel sector

    E-Print Network [OSTI]

    Xu, Jingsi, M.C.P. Massachusetts Institute of Technology

    2011-01-01

    In this study, I examine the spatial and economic factors that influence energy intensity in China's iron and steel sector, namely industrial value added, renovation investment, coke consumption, and local coke supply. ...

  12. Evidence for a Weak Iron Core at Earth's Center

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    iron grains in the Earth's inner core comes from x-ray spectroscopy and diffraction measurements performed at high pressure and utilizing, in part, ALS Beamline 12.2.2. When...

  13. Surface modifications of iron oxide nanoparticles for biological applications

    E-Print Network [OSTI]

    Insin, Numpon

    2011-01-01

    Iron oxides magnetic nanoparticles (MPs) of high crystallinity, high magnetization, and size-monodispersity were synthesized with oleic acid as their native ligands. These hydrophobic and non-functionalized MPs have magnetic ...

  14. Polymer-coated iron oxide nanoparticles for medical imaging

    E-Print Network [OSTI]

    Chen, Suelin, Ph.D. Massachusetts Institute of Technology

    2010-01-01

    One of the most versatile and safe materials used in medicine are polymer-coated iron oxide nanoparticles. This dissertation describes several formulations for in vivo imaging applications. The paramagnetic polymer-coated ...

  15. Iron Cycling and Redox Evolution in the Precambrian

    E-Print Network [OSTI]

    Planavsky, Noah John

    2012-01-01

    Black bar indicates PAAS shale composite values. Positive Cesystematics of black shales from the Middle ProterozoicIron speciation data for shales from the 1.64 Ga Mt. Isa

  16. Simulation of iron impurity gettering in crystalline silicon solar cells

    E-Print Network [OSTI]

    Powell, Douglas M. (Douglas Michael)

    2012-01-01

    This work discusses the Impurity-to-Efficiency (12E) simulation tool and applet. The 12E simulator models the physics of iron impurity gettering in silicon solar cells during high temperature processing. The tool also ...

  17. Virtual Iron Network Head node (currently not being used)

    E-Print Network [OSTI]

    Miller, Russ

    . Installation of UB's version of Fedora Linux on the nodes. This is accomplished by inserting an operating this information from UBIT office. 8. You are finished installing UB's version of Fedora Linux. Virtual Iron 1

  18. Evidence for a Weak Iron Core at Earth's Center

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Iron Core at Earth's Center Print Seismic waves that pass through the center of the Earth travel faster going from pole to pole than along the equatorial plane-why? One theory...

  19. The Iron Spin Transition in the Earth's Lower Mantle

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Print It is now known that the iron present in minerals of the lower mantle of the Earth undergoes a pressure-induced transition with pairing of the spins of its 3d electrons....

  20. Process for removing technetium from iron and other metals

    DOE Patents [OSTI]

    Leitnaker, J.M.; Trowbridge, L.D.

    1999-03-23

    A process for removing technetium from iron and other metals comprises the steps of converting the molten, alloyed technetium to a sulfide dissolved in manganese sulfide, and removing the sulfide from the molten metal as a slag. 4 figs.

  1. The relationship between iron and nitrogen fixation in Trichodesmium spp.

    E-Print Network [OSTI]

    Chappell, Phoebe Dreux

    2009-01-01

    Trichodesmium spp. are considered the dominant nitrogen (N) fixing cyanobacteria in tropical and subtropical oceans, regimes frequently characterized by low iron (Fe). Limited information exists about what levels of Fe ...

  2. Iron limitation and the role of Siderophores in marine Synechococcus

    E-Print Network [OSTI]

    Rivers, Adam R. (Adam Reid)

    2009-01-01

    Marine cyanobacteria in the genus Synechococcus are widely distributed and contribute significantly to global primary productivity. In many parts of the ocean their growth is limited by a lack of iron, an essential nutrient ...

  3. Friedel-Like Oscillations from Interstitial Iron in Superconducting...

    Office of Scientific and Technical Information (OSTI)

    Interstitial Iron in Superconducting Fe1+yTe0.62Se0.38 Using polarized and unpolarized neutron scattering we show that interstitial Fe in superconducting Fe1+yTe1-xSex...

  4. The industrial ecology of the iron casting industry

    E-Print Network [OSTI]

    Jones, Alissa J. (Alissa Jean)

    2007-01-01

    Metal casting is an energy and materials intensive manufacturing process, which is an important U.S. industry. This study analyzes iron casting, in particular, for possible improvements that will result in greater efficiencies ...

  5. Geologic evolution of Iron Mountain, central Mojave Desert, California

    E-Print Network [OSTI]

    Boettcher, Stefan S.; Walker, J. Douglas

    1993-04-01

    Geologic mapping, structural analysis, petrologic study, and U-Pb geochronology at Iron Mountain, 20 km southwest of Barstow, California, place important constraints on the paleogeographic affinities of metasedimentary rocks in the area and provide...

  6. Potential Antiferromagnetic Fluctuations in Hole-Doped Iron-Pnictide...

    Office of Scientific and Technical Information (OSTI)

    Fluctuations in Hole-Doped Iron-Pnictide Superconductor Ba1-xKxFe2As2 Studied by 75As Nuclear Magnetic Resonance Measurement0.1143JPSJ.81.054704 Citation Details In-Document...

  7. Probing high-energy spin fluctuations in iron pnictide superconductors...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Probing high-energy spin fluctuations in iron pnictide superconductors and the metal-insulator transition in rare-earth nickelates by soft X-ray RIXS Wednesday, November 18, 2015 -...

  8. The Iron Spin Transition in the Earth's Lower Mantle

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Transition in the Earth's Lower Mantle Print It is now known that the iron present in minerals of the lower mantle of the Earth undergoes a pressure-induced transition with pairing...

  9. In Situ Iron Oxide Emplacement for Groundwater Arsenic Remediation 

    E-Print Network [OSTI]

    Abia, Thomas Sunday

    2012-02-14

    Iron oxide-bearing minerals have long been recognized as an effective reactive media for arsenic-contaminated groundwater remediation. This research aimed to develop a technique that could facilitate in situ oxidative precipitation of Fe3+ in a soil...

  10. Evidence for a Weak Iron Core at Earth's Center

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Evidence for a Weak Iron Core at Earth's Center Print Seismic waves that pass through the center of the Earth travel faster going from pole to pole than along the equatorial...

  11. Evidence for a Weak Iron Core at Earth's Center

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Evidence for a Weak Iron Core at Earth's Center Print Wednesday, 30 April 2014 00:00 Seismic waves that pass through the center of the Earth travel faster going from pole to pole...

  12. Shewanella loihica sp. nov., isolated from iron-rich microbial...

    Office of Scientific and Technical Information (OSTI)

    loihica sp. nov., isolated from iron-rich microbial mats in the Pacific Ocean A novel marine bacterial strain, PV-4T, isolated from a microbial mat located at a hydrothermal vent...

  13. FGF23 is correlated with iron status but not with inflammation and decreases after iron supplementation: a supplementation study

    E-Print Network [OSTI]

    Braithwaite, Vickie; Prentice, Andrew M.; Doherty, Conor; Prentice, Ann

    2012-10-26

    ) and the subset study (n=79) was obtained. Written informed consent from the parents of the children involved were obtained for both the original iron supplementation trial and for any further analyses performed on stored samples. Anthropometry Weight was measured...

  14. Transport of fluorescently labeled hydroxyapatite nanoparticles in saturated granular media at environmentally relevant concentrations of surfactants

    SciTech Connect (OSTI)

    Wang, Dengjun; Su, Chuming; Liu, Chongxuan; Zhou, Dongmei

    2014-05-01

    Hydroxyapatite nanoparticle (nHAP) is being used to remediate soils and aquifers contaminated with metals and radionuclides; however, the mobility of nHAP is still poorly understood in subsurface granular environments. In this study, transport and retention kinetics of alizarin red S (ARS)-labeled nHAP were investigated in water-saturated quartz sand at low concentrations of surfactants: sodium dodecyl benzene sulfonate (SDBS, an anionic surfactant, 0–50 mg L–1) and cetyltrimethylammonium bromide (CTAB, a cationic surfactant, 0–5 mg L–1). Both surfactants were found to have a marked effect on the electrokinetic properties of ARS-nHAP and, consequently, on their transport and retention behaviors. Transport of nanoparticles (NPs) increased significantly with increasing SDBS concentration, largely because of enhanced colloidal stability and reduced aggregate size arising from enhanced electrostatic, osmotic, and elastic-steric repulsions between ARS-nHAP and sand grains. Conversely, transport decreased significantly in the presence of increasing CTAB concentrations due to reduced surface charge and consequential enhanced aggregation of the NPs. Osmotic and elastic-steric repulsions played only a minor role in enhancing the colloidal stability of ARS-nHAP in the presence of CTAB. Retention profiles of ARS-nHAP exhibited hyperexponential-shapes (decreasing rates of retention with increasing distance) for all conditions tested, and became more pronounced as CTAB concentration increased. The phenomenon was attributed to the aggregation and ripening of ARS-nHAP in the presence of surfactants, particularly CTAB. Overall, the present study suggests that surfactants at environmentally relevant concentrations may be an important consideration in employing nHAP for engineered in-situ remediation of certain metals and radionuclides in contaminated soils and aquifers.

  15. Interplay between interband coupling and ferromagnetism in iron pnictide superconductor/ferromagnet/iron pnictide superconductor junctions

    SciTech Connect (OSTI)

    Liu, S. Y.; Tao, Y. C.; Hu, J. G.

    2014-08-28

    An extended eight-component Bogoliubov-de Gennes equation is applied to study the Josephson effect between iron-based superconductors (SCs) with s{sub ±}-wave pairing symmetry, separated by an ferromagnet (FM). The feature of damped oscillations of critical Josephson current as a function of FM thickness, the split of the peaks induced by the interband coupling is much different from that for the junction with the s{sub ±}-wave SCs replaced by s{sub ++}-wave ones. In particular, a 0?? transition as a function of interband coupling strength ? is found to always exhibit with the corresponding dip shifting toward the larger ? due to enhancing the spin polarization in the FM, while there exits no 0?? transition for the SC with s{sub ++}-wave pairing symmetry. The two features can be used to identify the pairing symmetry in the iron pnictide SC different from the s{sub ++}-wave one in MgB{sub 2}. Experimentally, by adjusting the doping level in the s{sub ±}-wave SCs, one can vary ?.

  16. Microstructural Characterization of Nodular Ductile Iron

    SciTech Connect (OSTI)

    Springer, H K

    2012-01-03

    The objective of this study is to quantify the graphite particle phase in nodular ductile iron (NDI). This study provides the basis for initializing microstructure in direct numerical simulations, as part of developing microstructure-fracture response models. The work presented here is a subset of a PhD dissertation on spall fracture in NDI. NDI is an ideal material for studying the influence of microstructure on ductile fracture because it contains a readily identifiable second-phase particle population, embedded in a ductile metallic matrix, which serves as primary void nucleation sites. Nucleated voids grow and coalesce under continued tensile loading, as part of the micromechanisms of ductile fracture, and lead to macroscopic failure. For this study, we used 2D optical microscopy and quantitative metallography relationships to characterize the volume fraction, size distribution, nearest-neighbor distance, and other higher-order metrics of the graphite particle phase. We found that the volume fraction was {Phi} = 0.115, the average particle diameter was d{sub avg} = 25.9 {mu}m, the Weibull shape and scaling parameters were {beta} = 1.8 and {eta} = 29.1 {mu}m, respectively, the (first) nearest neighbor distance was L{sub nn} = 32.4 {mu}m, the exponential coefficients for volume fraction fluctuations was A{sub {Phi}} = 1.89 and B{sub {Phi}} = -0.59, respectively. Based on reaching a coefficient-of-variation (COV) of 0.01, the representative volume element (RVE) size was determined to be 8.9L{sub nn} (288 {mu}m).

  17. Insights into the Structure and Metabolic Function of Microbes That Shape Pelagic Iron-Rich Aggregates ( Iron Snow )

    SciTech Connect (OSTI)

    Lu, S; Chourey, Karuna; REICHE, M; Nietzsche, S; Shah, Manesh B; Hettich, Robert {Bob} L; Kusel, K

    2013-01-01

    Metaproteomics combined with total nucleic acid-based methods aided in deciphering the roles of microorganisms in the formation and transformation of iron-rich macroscopic aggregates (iron snow) formed in the redoxcline of an acidic lignite mine lake. Iron snow had high total bacterial 16S rRNA gene copies, with 2 x 109 copies g (dry wt)-1 in the acidic (pH 3.5) central lake basin and 4 x 1010 copies g (dry wt)-1 in the less acidic (pH 5.5) northern lake basin. Active microbial communities in the central basin were dominated by Alphaproteobacteria (36.6%) and Actinobacteria (21.4%), and by Betaproteobacteria (36.2%) in the northern basin. Microbial Fe-cycling appeared to be the dominant metabolism in the schwertmannite-rich iron snow, because cloning and qPCR assigned up to 61% of active bacteria as Fe-cycling bacteria (FeB). Metaproteomics revealed 70 unique proteins from central basin iron snow and 283 unique proteins from 43 genera from northern basin. Protein identification provided a glimpse into in situ processes, such as primary production, motility, metabolism of acidophilic FeB, and survival strategies of neutrophilic FeB. Expression of carboxysome shell proteins and RubisCO indicated active CO2 fixation by Fe(II) oxidizers. Flagellar proteins from heterotrophs indicated their activity to reach and attach surfaces. Gas vesicle proteins related to CO2-fixing Chlorobium suggested that microbes could influence iron snow sinking. We suggest that iron snow formed by autotrophs in the redoxcline acts as a microbial parachute, since it is colonized by motile heterotrophs during sinking which start to dissolve schwertmannite.

  18. A Long, Contingent Path to Comparative Advantage: Industrial Policy and the Japanese Iron and Steel Industry, 1900-1973

    E-Print Network [OSTI]

    ELBAUM, BERNARD

    2006-01-01

    mining, shipping, shipbuilding, engineering, cement, and chemicals, as well as iron andmining and processing of taconite ores, which contain ironTanaka Mining), by the late 1920s, the cost of pig iron

  19. A rheometer for measuring the material moduli for granular solids. Final report, August 7, 1990--February 6, 1995

    SciTech Connect (OSTI)

    Rajagopal, K.R.

    1998-03-01

    A great many industrial processes involve interaction between solids and fluids (i.e. gases or liquids). Combustion, gasification of solid fuels, shales or solid wastes, drying of particles, calcining, particle heating, regenerative heat exchangers, oxidation or reduction of ores, metal surface treatments and catalytic and thermal cracking are some of such processes. Solids and fluids serve different roles and several combinations of solids and fluids can arise in a practical situation. Thus, when considering processes or plants it is necessary to be clear as to the particular purpose served by the fluids and the solids. Heating and drying of solids, for example, involve heat and mass transfer only, whereas combustors, gasifiers etc. have the additional complication of chemical reactions which have to be carried out simultaneously with heat and mass transfer. Again, there are many processes where just the flow of granular particles take place, for example, the flow of food grain, coal or sand particles through bin, silo, hoppers, chutes, conveyor belts, inclined planes etc. In most of these cases, a theoretical modeling of the process requires a complete and thorough understanding of the phenomena involved and constitutive modeling of the constituents along with the usual balance laws. In a process, where both a fluid and a solid constituents are involved, it is essential to model both the constituents such that the models accurately describes the characteristics of the constituent concerned. While there are many different models available for fluids, the models for granular materials lack from an understanding of the material parameters.

  20. Emergence of granular-sized magnetic bubbles through the solar atmosphere. I. Spectropolarimetric observations and simulations

    SciTech Connect (OSTI)

    Ortiz, Ada; Hansteen, Viggo H.; Van der Voort, Luc Rouppe [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, N-0315 Oslo (Norway); Bellot Rubio, Luis R. [Instituto de Astrofísica de Andalucía (CSIC), Apdo. 3040, E-18080 Granada (Spain); De la Cruz Rodríguez, Jaime, E-mail: ada@astro.uio.no [Department of Physics and Astronomy, Uppsala University, Box 516, SE-75120 Uppsala (Sweden)

    2014-02-01

    We study a granular-sized magnetic flux emergence event that occurred in NOAA 11024 in 2009 July. The observations were made with the CRISP spectropolarimeter at the Swedish 1 m Solar Telescope achieving a spatial resolution of 0.''14. Simultaneous full Stokes observations of the two photospheric Fe I lines at 630.2 nm and the chromospheric Ca II 854.2 nm line allow us to describe in detail the emergence process across the solar atmosphere. We report here on three-dimensional (3D) semi-spherical bubble events, where instead of simple magnetic footpoints, we observe complex semi-circular feet straddling a few granules. Several phenomena occur simultaneously, namely, abnormal granulation, separation of opposite-polarity legs, and brightenings at chromospheric heights. However, the most characteristic signature in these events is the observation of a dark bubble in filtergrams taken in the wings of the Ca II 854.2 nm line. There is a clear coincidence between the emergence of horizontal magnetic field patches and the formation of the dark bubble. We can infer how the bubble rises through the solar atmosphere as we see it progressing from the wings to the core of Ca II 854.2 nm. In the photosphere, the magnetic bubble shows mean upward Doppler velocities of 2 km s{sup –1} and expands at a horizontal speed of 4 km s{sup –1}. In about 3.5 minutes it travels some 1100 km to reach the mid chromosphere, implying an average ascent speed of 5.2 km s{sup –1}. The maximum separation attained by the magnetic legs is 6.''6. From an inversion of the observed Stokes spectra with the SIR code, we find maximum photospheric field strengths of 480 G and inclinations of nearly 90° in the magnetic bubble interior, along with temperature deficits of up to 250 K at log ? = –2 and above. To aid the interpretation of the observations, we carry out 3D numerical simulations of the evolution of a horizontal, untwisted magnetic flux sheet injected in the convection zone, using the Bifrost code. The computational domain spans from the upper convection zone to the lower corona. In the modeled chromosphere, the rising flux sheet produces a large, cool, magnetized bubble. We compare this bubble with the observed ones and find excellent agreement, including similar field strengths and velocity signals in the photosphere and chromosphere, temperature deficits, ascent speeds, expansion velocities, and lifetimes.

  1. Zinc sorption by iron oxides and soil samples 

    E-Print Network [OSTI]

    Yli-Halla, Markku Juhani

    1989-01-01

    'r Subject: Soil Science ZINC SORPTION BY IRON OXIDES AND SOIL SAMPLES A Thesis by MARKKU JUHANI YLI-HALLA Approved as to style and content by: Richard H. Loeppert (Chair of Committee) A. Clearfield (Membe ) Joe B. Dixon (Member) E. C. A. Runge... (Head of Department) May 1989 ABSTRACT Zinc Sorption by Iron Oxides and Soil Samples. (May 1989) Markku Juhani Yli-Halla, M. S. University of Helsinki, Finland Chair of Advisory Committee: Dr. Richard H. Loeppert Zn sorption by synthetic Fe oxide...

  2. Magnetic properties of iron yoke laminations for SSC dipole magnets

    SciTech Connect (OSTI)

    Kahn, S.A.; Morgan, G.H.

    1991-01-01

    We examine the magnetic properties for the iron used in the SSC yoke laminations so that the accelerator tolerances can be met. The accelerator requirements for field quality specify a tolerance on the variation in the central field. At machine injection the variation in field is attributed to coercivity, H{sub c}. Requirements on the magnitude and the variation of H{sub c} are presented. At the 6.65 tesla operating field the variation in the saturation magnetization dominates the magnetic tolerance for the iron. 4 refs., 3 figs., 2 tabs.

  3. Electronic spin state of iron in lower mantle perovskite

    SciTech Connect (OSTI)

    Li, J.; Struzhkin, V.; Mao, H.-k.; Shu, J.; Hemley, R.; Fei, Y.; Mysen, B.; Dera, P.; Parapenka, V.; Shen, G.

    2010-11-16

    The electronic spin state of iron in lower mantle perovskite is one of the fundamental parameters that governs the physics and chemistry of the most voluminous and massive shell in the Earth. We present experimental evidence for spin-pairing transition in aluminum-bearing silicate perovskite (Mg,Fe)(Si,Al)O{sub 3} under the lower mantle pressures. Our results demonstrate that as pressure increases, iron in perovskite transforms gradually from the initial high-spin state toward the final low-spin state. At 100 GPa, both aluminum-free and aluminum-bearing samples exhibit a mixed spin state. The residual magnetic moment in the aluminum-bearing perovskite is significantly higher than that in its aluminum-free counterpart. The observed spin evolution with pressure can be explained by the presence of multiple iron species and the occurrence of partial spin-paring transitions in the perovskite. Pressure-induced spin-pairing transitions in the perovskite would have important bearing on the magnetic, thermoelastic, and transport properties of the lower mantle, and on the distribution of iron in the Earth's interior. The lower mantle constitutes more than half of the Earth's interior by volume (1), and it is believed to consist predominantly (80-100%) of (Mg,Fe)(Si,Al)O{sub 3} perovskite (hereafter called perovskite), with up to 20% (Mg,Fe)O ferropericlase (2). The electronic spin state of iron has direct influence on the physical properties and chemical behavior of its host phase. Hence, knowledge on the spin state of iron is important for the interpretation of seismic observations, geochemical modeling, and geodynamic simulation of the Earth's deep interior (3, 4). Crystal field theory (4, 5) and band theory (6) predicted that a high-spin to low-spin transition would occur as a result of compression. To date, no experimental data exist on the spin sate of iron in Al-bearing perovskite. To detect possible spinpairing transition of iron in perovskite under the lower mantle conditions, we measured the x-ray emission spectra of an Al-bearing perovskite sample to 100 GPa. For comparison, a parallel measurement was also carried out on an Al-free perovskite sample.

  4. Recovery of iron oxide from coal fly ash

    DOE Patents [OSTI]

    Dobbins, Michael S. (Ames, IA); Murtha, Marlyn J. (Ames, IA)

    1983-05-31

    A high quality iron oxide concentrate, suitable as a feed for blast and electric reduction furnaces is recovered from pulverized coal fly ash. The magnetic portion of the fly ash is separated and treated with a hot strong alkali solution which dissolves most of the silica and alumina in the fly ash, leaving a solid residue and forming a precipitate which is an acid soluble salt of aluminosilicate hydrate. The residue and precipitate are then treated with a strong mineral acid to dissolve the precipitate leaving a solid residue containing at least 90 weight percent iron oxide.

  5. The Iron Spin Transition in the Earth's Lower Mantle

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorking With U.S.Week Day Year(activeInforum LIFT ModelThe Iron SpinThe Iron

  6. Iron and Steel (2010 MECS) | Department of Energy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACT EVALUATIONIntroducing the RichardBudgetIowaOctoberNovemberIron FindIron

  7. Iron is the Key to Preserving Dinosaur Soft Tissue

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACT EVALUATIONIntroducing the RichardBudgetIowaOctoberNovemberIronIron is

  8. Iron is the Key to Preserving Dinosaur Soft Tissue

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACT EVALUATIONIntroducing the RichardBudgetIowaOctoberNovemberIronIron

  9. Iron is the Key to Preserving Dinosaur Soft Tissue

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation CurrentHenryInhibitingInteractivePGAS andUniversity Ion BeamsIraIronIron is

  10. Iron is the Key to Preserving Dinosaur Soft Tissue

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation CurrentHenryInhibitingInteractivePGAS andUniversity Ion BeamsIraIronIron

  11. Structural insight into the assembly of iron-sulfur clusters and their function in radical generation

    E-Print Network [OSTI]

    Vey, Jessica L. (Jessica Lynn)

    2008-01-01

    This thesis addresses two emerging areas in the study of iron-sulfur cluster biochemistry: bioassembly of iron-sulfur clusters, and their involvement in initiation of radical chemistry. The structure of a cysteine desulfurase ...

  12. Interactions of Fe(II) with the iron oxidizing bacterium Rhodopseudomonas palustris TIE-1

    E-Print Network [OSTI]

    Bird, Lina J. (Lina Joana)

    2013-01-01

    Microbial anaerobic iron oxidation has long been of interest to biologists and geologists, both as a possible mechanism for the creation of banded iron formations before the rise of oxygen, and as a model system for organisms ...

  13. Characterization of temperature profile in furnace and solubility of iron in silicon

    E-Print Network [OSTI]

    Modi, Vrajesh Y

    2011-01-01

    A better understanding of the behavior of impurities, such as iron, in silicon can lead to increases in solar cell efficiency. The purpose of this thesis was to study the behavior of iron in silicon via three sub-tasks: ...

  14. Fe isotope and trace element geochemistry of the Neoproterozoic syn-glacial Rapitan iron formation

    E-Print Network [OSTI]

    Long, Bernard

    pattern likely records a steep isotopic gradient across the iron chemocline in Rapitan seawater. © 2011 metabolism, and function as a micronu- trient (Anbar, 2004; Beard et al., 2003a; Johnson et al., 2008a). Iron

  15. Evaluation of residual stress gradients in ductile cast iron using critical refracted longitudinal (Lcr) wave technique 

    E-Print Network [OSTI]

    Pfluger, Ron Atlan

    1995-01-01

    Critically refracted longitudinal (LCR) waves have been investigated as a possible technique for the evaluation of the residual stress gradients present in ductile iron castings. Residual stresses are likely to develop in ductile cast iron during...

  16. ITP Steel: Energy and Environmental Profile fo the U.S. Iron...

    Energy Savers [EERE]

    U.S. Iron and Steel Industry steelprofile.pdf More Documents & Publications ITP Steel: Energy and Environmental Profile fo the U.S. Iron and Steel Industry Bandwidth Study U.S....

  17. Encapsulation of Iron Hydroxide Floc in Composite Cement Nick C Collier* and Neil B Milestone

    E-Print Network [OSTI]

    Sheffield, University of

    Plant (EARP) at Sellafield treats liquid effluent generated during reprocessing by co-precipitating uranium, plutonium and other actinides, as well as some other radioactive species, with iron as iron

  18. NORTHWEST AFRICA 176: A UNIQUE IRON METEORITE WITH SILICATE INCLUSIONS RELATED TO BOCAIUVA. Menghua Liu

    E-Print Network [OSTI]

    Floss, Christine

    NORTHWEST AFRICA 176: A UNIQUE IRON METEORITE WITH SILICATE INCLUSIONS RELATED TO BOCAIUVA. Menghua Africa 176 iron me- teorite with silicate inclusions was found at the border of Morocco and Algeria

  19. ITmk3: High-Quality Iron Nuggets Using a Rotary Hearth Furnace...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    to reopen a nearby iron-ore mine to reduce material costs; Mesabi currently must purchase iron-ore from other mining operations. Material cost reduction is a key component to...

  20. IRON STATUS AND DIETARY AND ANTHROPOMETRIC RISK FACTORS IN US TODDLERS

    E-Print Network [OSTI]

    Kerling, Elizabeth Helen

    2008-05-01

    Iron deficiency (ID) is a common problem among US children but diagnosis requires four tests. An equation using only the logarithmic ratio of circulating transferrin receptor to ferritin has been proposed to quantify body iron in adults, however...

  1. Sedimentary and mineral dust sources of dissolved iron to the world ocean

    E-Print Network [OSTI]

    Moore, J. K; Braucher, O.

    2008-01-01

    of the tropi- cal Pacific Ocean II. Iron biogeochemistry,in the Northeast Pacific Ocean Gyre: Aerosols, iron, and theF. M. M. : The equatorial Pacific Ocean: Grazer-controlled

  2. How Godzilla Ate Pittsburgh: The Long Rise of the Japanese Iron and Steel Industry, 1900–1973

    E-Print Network [OSTI]

    Bernard Elbaum

    2007-01-01

    poorly endowed as Japan in coking coal and iron ore (WarrenYawata of iron ore for coking coal and the progressive in-

  3. Polygons vs. clumps of discs: a numerical study of the influence of grain shape on the mechanical behaviour of granular materials

    E-Print Network [OSTI]

    K. Szarf; G. Combe; P. Villard

    2012-08-02

    We performed a series of numerical vertical compression tests on assemblies of 2D granular material using a Discrete Element code and studied the results with regard to the grain shape. The samples consist of 5,000 grains made from either 3 overlapping discs (clumps - grains with concavities) or six-edged polygons (convex grains). These two grain type have similar external envelopes, which is a function of a geometrical parameter $\\alpha$. In this paper, the numerical procedure applied is briefly presented followed by the description of the granular model used. Observations and mechanical analysis of dense and loose granular assemblies under isotropic loading are made. The mechanical response of our numerical granular samples is studied in the framework of the classical vertical compression test with constant lateral stress (biaxial test). The comparison of macroscopic responses of dense and loose samples with various grain shapes shows that when $\\alpha$ is considered a concavity parameter, it is therefore a relevant variable for increasing mechanical performances of dense samples. When $\\alpha$ is considered an envelope deviation from perfect sphericity, it can control mechanical performances for large strains. Finally, we present some remarks concerning the kinematics of the deformed samples: while some polygon samples subjected to a vertical compression present large damage zones (any polygon shape), dense samples made of clumps always exhibit thin reflecting shear bands. This paper was written as part of a CEGEO research project www.granuloscience.com

  4. may also explain the larger extent of quiet Sun spicules1,2 mode power and granular flows are stronger by up to 50% and

    E-Print Network [OSTI]

    Johnson, Peter D.

    may also explain the larger extent of quiet Sun spicules1,2 where p- mode power and granular flows 2004; doi:10.1038/nature02749. 1. Beckers, J. M. Solar spicules. Sol. Phys. 3, 367­433 (1968). 2. Beckers, J. M. Solar spicules. Annu. Rev. Astron. Astrophys. 10, 73­100 (1972). 3. Sterling, A. C. Solar

  5. Static and flowing regions in granular collapses down channels Research Division "Dynamics of the Ocean Floor," IFM-GEOMAR, Leibniz Institute for Marine Sciences,

    E-Print Network [OSTI]

    Huppert, Herbert

    Static and flowing regions in granular collapses down channels Gert Lube Research Division of an internal interface separating static and flowing regions. We present data for the time-dependent geometry approaches. First, by integrating under the entire internal interface we obtained data for the static area

  6. "Granular jets and hydraulic jumps on an inclined plane", C. G. Johnson, J. M. N. T. Gray ( ), J. Fluid Mech., (Submitted)

    E-Print Network [OSTI]

    Sidorov, Nikita

    · "Granular jets and hydraulic jumps on an inclined plane", C. G. Johnson, J. M. N. T. Gray ( ), J material impinging on an inclined plane pro- duces a diverse range of ows, from steady hydraulic jumps-moving radial ow, surrounded by either a teardrop-shaped, or a `blunted' hydraulic jump. A depth

  7. Manufacturing Energy and Carbon Footprint- Sector: Iron and Steel (NAICS 3311, 3312), October 2012 (MECS 2006)

    Broader source: Energy.gov [DOE]

    Manufacturing Energy and Carbon Footprint for Iron and Steel Sector (NAICS 3311, 3312) with Total Energy Input

  8. 2-54 GEOLOGICAL & ENVIRONMENTAL SCIENCES Mechanisms of Selenate Adsorption on Iron

    E-Print Network [OSTI]

    Sparks, Donald L.

    mechanisms on hematite (-Fe2 O3 ), goethite (-FeOOH), and amorphous iron hydroxide (Fe(OH)3 ). Selenate (SeO4 to hema- tite (-Fe2 O3 ), goethite (-FeOOH), and amorphous iron hydroxide (Fe(OH)3 ). The objectives adsorption mechanisms. Hematite, goethite, and amorphous iron hydroxide were chosen due to their important

  9. Persistence of iron limitation in the western subarctic Pacific SEEDS II mesoscale fertilization experiment

    E-Print Network [OSTI]

    Cochlan, William P.

    Persistence of iron limitation in the western subarctic Pacific SEEDS II mesoscale fertilization t The cumulative evidence from more than a dozen mesoscale iron-enrichment studies in high nitrate low chlorophyll diatoms, vary greatly among these mesoscale experiments even though similar amounts of iron were added

  10. Ice iron/sodium film as cause for high noctilucent cloud radar reflectivity

    E-Print Network [OSTI]

    Bellan, Paul M.

    Ice iron/sodium film as cause for high noctilucent cloud radar reflectivity P. M. Bellan1 Received by assuming the ice grains are coated by a thin metal film; substantial evidence exists indicating that such a film exists and is caused by the deposition of iron and sodium atoms on the ice grain from iron

  11. The Continental Margin is a Key Source of Iron to the HNLC North Pacific Ocean

    E-Print Network [OSTI]

    The Continental Margin is a Key Source of Iron to the HNLC North Pacific Ocean Phoebe J. Lam1 concentrations in the upper 500m of the Western Subarctic Pacific, an iron-limited High Nutrient Low Chlorophyll a key source of bioavailable Fe to the HNLC North Pacific. Keywords: iron, continental margin, HNLC 1

  12. Precipitation of interstitial iron in multicrystalline silicon AnYao Liu1, a

    E-Print Network [OSTI]

    Precipitation of interstitial iron in multicrystalline silicon AnYao Liu1, a and Daniel Macdonald1, multicrystalline silicon, precipitation, supersaturation, spatial distribution Abstract The internal gettering of iron in silicon via iron precipitation at low processing temperatures is known to improve solar cell

  13. Precipitation of iron in multicrystalline silicon during annealing A. Y. Liu and Daniel Macdonald

    E-Print Network [OSTI]

    Precipitation of iron in multicrystalline silicon during annealing A. Y. Liu and Daniel Macdonald.203.43.22 On: Tue, 18 Mar 2014 02:19:30 #12;Precipitation of iron in multicrystalline silicon during annealing 2014) In this paper, the precipitation kinetics of iron in multicrystalline silicon during moderate

  14. Deactivation by carbon of iron catalysts for indirect liquefaction

    SciTech Connect (OSTI)

    Bartholomew, C H

    1991-02-14

    Progress is reported for a four-year fundamental investigation of carbon formation and its effects on the activity and selectivity of promoted iron catalysts for FT synthesis, the objectives of which were to (1) determine rates and mechanisms of carbon deactivation of unsupported Fe and Fe/K catalysts during CO hydrogenation and (2) model the global rates of deactivation at the surface of the catalyst for the same catalysts. A computer-automated reactor system to be used in the kinetic and deactivation studies was designed, constructed and tested. Kinetic data for CO hydrogenation on unsupported, unpromoted iron, 99% Fe/1% Al{sub 2}O{sub 3}, and K-promoted 99% Fe/1% Al{sub 2}O{sub 3} catalysts were obtained as functions of temperature, reactant particle pressures and time. The activity/selectivity and kinetic data are consistent with those previously reported for supported, unpromoted and promoted iron. Two kinds of deactivation were observed during FT synthesis on these samples: (1) loss of surface area after reduction of unsupported, unpromoted iron at 400{degree}C and (2) loss of activity with time due to carbon deposition, especially in the case of K-promoted 99% Fe/1% A1{sub 2}O{sub 3}. Deactivation rate data were obtained for CO hydrogenation on promoted Fe as a function of time, temperature, and H{sub 2}/CO ratio. 50 refs., 24 figs., 5 tabs.

  15. RESEARCH PAPER Fabrication and characterization of iron oxide nanoparticles

    E-Print Network [OSTI]

    Guo, John Zhanhu

    stirring for the micron-sized iron oxide particles filled PPy composite fabrication. Keywords Polymer Nanomanufacturing Introduction Polypyrrole (PPy), a conducting conjugated polymer, has attracted much interest due). The conductivity of a conductive polymer is strongly dependent on the doping agents (dopant) with electron donor

  16. Molten thermite teeming into an iron oxide particle bed

    SciTech Connect (OSTI)

    Tarbell, W.W.; Blose, R.E.; Arellano, F.E.

    1984-03-01

    The two particle bed tests employed 10-kg thermite melts (2700/sup 0/K) teemed into a bed of iron oxide particles. Objective was to investigate bed penetration, particle flotation and fracture, and heat flux partitioning. The results show that the hydraulic forces exerted by the melt did not immediately displace the bed. Bed penetration was by melting and absorbing of the particles with the major portion of the displaced iron oxide terminating in the alumina phase of the melt. The movement of the penetration front suggests the movement to be a series of melt/freeze/remelt processes. The large grain structure of the iron phase indicates that the cooling was slow and continuous. A coherent 1-cm-thick layer of iron oxide in contact with the melt was created by sintering of the particles. The particle size of the unaffected portions of the bed showed very little fracturing due to thermal stress and slightly over 7% particle growth due to sintering. The calculated heat flux values to the surrounding crucible structure suggest that the bed is effective in delaying and reducing the magnitude of the peak heat flux values.

  17. Oxide Dispersion Strengthened Iron Aluminide by CVD Coated Powders

    SciTech Connect (OSTI)

    Asit Biswas Andrew J. Sherman

    2006-09-25

    This I &I Category2 program developed chemical vapor deposition (CVD) of iron, aluminum and aluminum oxide coated iron powders and the availability of high temperature oxidation, corrosion and erosion resistant coating for future power generation equipment and can be used for retrofitting existing fossil-fired power plant equipment. This coating will provide enhanced life and performance of Coal-Fired Boilers components such as fire side corrosion on the outer diameter (OD) of the water wall and superheater tubing as well as on the inner diameter (ID) and OD of larger diameter headers. The program also developed a manufacturing route for readily available thermal spray powders for iron aluminide coating and fabrication of net shape component by powder metallurgy route using this CVD coated powders. This coating can also be applid on jet engine compressor blade and housing, industrial heat treating furnace fixtures, magnetic electronic parts, heating element, piping and tubing for fossil energy application and automotive application, chemical processing equipment , heat exchanger, and structural member of aircraft. The program also resulted in developing a new fabrication route of thermal spray coating and oxide dispersion strengthened (ODS) iron aluminide composites enabling more precise control over material microstructures.

  18. Iron dysregulation in movement disorders Petr Dusek a,c

    E-Print Network [OSTI]

    a Parkinson's Disease Center and Movement Disorders Clinic, Department of Neurology, Baylor College of Medicine, Houston, TX 77030, USA b Parkinson's Disease Research Laboratory, Department of Neurology, Baylor Dystonia Parkinson's disease Chelating agents Iron is an essential element necessary for energy production

  19. Aerosol Synthesis and Growth Mechanism of Magnetic Iron Nanoparticles

    E-Print Network [OSTI]

    rapidly over the past decades, such as mechanical milling, spray drying, sol-gel, sonochemistry, etcAerosol Synthesis and Growth Mechanism of Magnetic Iron Nanoparticles D. Kim1,a , E.S. Vasilieva2,b, evaporated and transported by carrier gas flow to the preliminary heated tubular furnace for decomposition

  20. Hydrocarbon Formation in Metallic Iron/Water Systems

    E-Print Network [OSTI]

    Deng, Baolin

    Hydrocarbon Formation in Metallic Iron/Water Systems B A O L I N D E N G , , § T I M O T H Y J . C-labeled hydrocarbons are produced. In the absence of chlorinated ethenes, however, lower con- centrations of many of the same hydrocarbons (methane and C2-C6 alkanes and alkenes) are also produced. Hardy and Gillham (1996

  1. Quantifying the Micromechanical Effects of Variable Cement in Granular Porous Media

    SciTech Connect (OSTI)

    Goodwin, Laurel B.; Boutt David F.

    2010-02-18

    The mechanical and hydrologic behavior of clastic rocks and sediments is fundamentally controlled by variables such as grain size and shape, sorting, grain and cement mineralogy, porosity, and %cement - parameters that are not used directly in field-scale models of coupled flow and deformation. To improve our understanding of the relationship between these micromechanical properties and bulk behavior we focused on (1) relating detailed, quantitative characterization of the grain-pore systems to both hydrologic and mechanical properties of a suite of variably quartz-cemented quartz arenite samples and (2) the use of a combination of discrete element method (DEM) and poroelastic models parameterized by data from the natural samples to isolate and compare the influence of changes in the mechanical and hydrologic properties of granular porous media due to changes in degree of cementation. Quartz overgrowths, the most common form of authigenic cements in sandstones, are responsible for significant porosity and permeability reduction. The distribution of quartz overgrowths is controlled by available pore space and the crystallographic orientations of individual quartz grains. Study of the St. Peter Sandstone allowed evaluation of the relative effects of quartz cementation and compaction on final grain and pore morphology, showing that progressive quartz cementation modifies the grain framework in consistent, predictable ways. Detailed microstructural characterization and multiple regression analyses show that with progressive diagenesis, the number and length of grain contacts increases as the number of pores increases, the number of large, well-connected pores decreases, and pores become rounder. These changes cause a decrease in pore size variability that leads to a decrease in bulk permeability and both stiffening and strengthening of the grain framework. The consistent nature of these changes allows us to predict variations in hydrologic and mechanical properties with progressive diagenesis, and explore the impact of these changes on aquifer behavior. Several examples of this predictive capability are offered. In one application, data from natural sandstones are used to calibrate the proportionality constant of the Kozeny-Carman relationship, improving the ability to predict permeability in quartz-cemented quartz arenites. In another, the bond-to-grain ratio (BGR) is used to parameterize a discrete element model with data acquired from sandstone samples. The DEM results provide input to poroelastic models used to explore the hydrologic, mechanical, and coupled hydrologic and mechanical response of the sandstone to pumping stresses. This modeling exercise shows that at the macro-scale, changes in mechanical and hydrologic properties directly influence the magnitude and area of aquifer deformation. The significant difference in sensitivity of the system to the mechanical properties alone versus its sensitivity to coupled mechanical and hydrologic properties demonstrates the importance of including hydrologic properties that are adjusted for changes in cementation in fluid storage and deformation studies. The large magnitude of radial deformation compared to vertical deformation in these models emphasizes the importance of considering three dimensional deformation in fluid flow and deformation studies.

  2. Use of high-granularity position sensing to correct response non-uniformities of CdZnTe detectors

    SciTech Connect (OSTI)

    Bolotnikov, A. E. Camarda, G. S.; Cui, Y.; De Geronimo, G.; Fried, J.; Hossain, A.; Mahler, G.; Maritato, M.; Marshall, M.; Roy, U.; Vernon, E.; Yang, G.; James, R. B.; Lee, K.; Petryk, M.

    2014-06-30

    CdZnTe (CZT) is a promising medium for room-temperature gamma-ray detectors. However, the low production yield of acceptable quality crystals hampers the use of CZT detectors for gamma-ray spectroscopy. Significant efforts have been directed towards improving quality of CZT crystals to make them generally available for radiation detectors. Another way to address this problem is to implement detector designs that would allow for more accurate and predictable correction of the charge loss associated with crystal defects. In this work, we demonstrate that high-granularity position-sensitive detectors can significantly improve the performance of CZT detectors fabricated from CZT crystals with wider acceptance boundaries, leading to an increase of their availability and expected decrease in cost.

  3. High granularity tracker based on a Triple-GEM optically read by a CMOS-based camera

    E-Print Network [OSTI]

    Michela Marafini; Vincenzo Patera; Davide Pinci; Alessio Sarti; A. Sciubba; Eleuterio Spiriti

    2015-10-29

    The detection of photons produced during the avalanche development in gas chambers has been the subject of detailed studies in the past. The great progresses achieved in last years in the performance of micro-pattern gas detectors on one side and of photo-sensors on the other provide the possibility of making high granularity and very sensitive particle trackers. In this paper, the results obtained with a triple-GEM structure read-out by a CMOS based sensor are described. The use of an He/CF$_4$ (60/40) gas mixture and a detailed optimization of the electric fields made possible to obtain and very high GEM light yield. About 80 photons per primary electron were detected by the sensor resulting in a very good capability of tracking both muons from cosmic rays and electrons from natural radioactivity.

  4. High granularity tracker based on a Triple-GEM optically read by a CMOS-based camera

    E-Print Network [OSTI]

    Michela Marafini; Vincenzo Patera; Davide Pinci; Alessio Sarti; A. Sciubba; Eleuterio Spiriti

    2015-09-18

    The detection of photons produced during the avalanche development in gas chambers has been the subject of detailed studies in the past. The great progresses achieved in last years in the performance of micro-pattern gas detectors on one side and of photo-sensors on the other provide the possibility of making high granularity and very sensitive particle trackers. In this paper, the results obtained with a triple-GEM structure read-out by a CMOS based sensor are described. The use of an He/CF$_4$ (60/40) gas mixture and a detailed optimization of the electric fields made possible to obtain and very high GEM light yield. About 80 photons per primary electron were detected by the sensor resulting in a very good capability of tracking both muons from cosmic rays and electrons from natural radioactivity.

  5. Construction and commissioning of a technological prototype of a high-granularity semi-digital hadronic calorimeter

    E-Print Network [OSTI]

    G. Baulieu; M. Bedjidian; K. Belkadhi; J. Berenguer; V. Boudry; P. Calabria; S. Callier; E. Calvo Almillo; S. Cap; L. Caponetto; C. Combaret; R. Cornat; E. Cortina Gil; B. de Callatay; F. Davin; C. de la Taille; R. Dellanegra; D. Delaunay; F. Doizon; F. Dulucq; A. Eynard; M-C. Fouz; F. Gastaldi; L. Germani; G. Grenier; Y. Haddad; R. Han; J-C. Ianigro; R. Kieffer; I. Laktineh; N. Lumb; K. Manai; S. Mannai; H. Mathez; L. Mirabito; J. Prast; J. Puerta Pelayo; M. Ruan; F. Schirra; N. Seguin-Moreau; A. Steen; W. Tromeur; M. Tytgat; M. Vander Donckt; G. Vouters; N. Zaganidis

    2015-10-24

    A large prototype of 1.3m3 was designed and built as a demonstrator of the semi-digital hadronic calorimeter (SDHCAL) concept proposed for the future ILC experiments. The prototype is a sampling hadronic calorimeter of 48 units. Each unit is built of an active layer made of 1m2 Glass Resistive Plate Chamber(GRPC) detector placed inside a cassette whose walls are made of stainless steel. The cassette contains also the electronics used to read out the GRPC detector. The lateral granularity of the active layer is provided by the electronics pick-up pads of 1cm2 each. The cassettes are inserted into a self-supporting mechanical structure built also of stainless steel plates which, with the cassettes walls, play the role of the absorber. The prototype was designed to be very compact and important efforts were made to minimize the number of services cables to optimize the efficiency of the Particle Flow Algorithm techniques to be used in the future ILC experiments. The different components of the SDHCAL prototype were studied individually and strict criteria were applied for the final selection of these components. Basic calibration procedures were performed after the prototype assembling. The prototype is the first of a series of new-generation detectors equipped with a power-pulsing mode intended to reduce the power consumption of this highly granular detector. A dedicated acquisition system was developed to deal with the output of more than 440000 electronics channels in both trigger and triggerless modes. After its completion in 2011, the prototype was commissioned using cosmic rays and particles beams at CERN.

  6. Construction and commissioning of a technological prototype of a high-granularity semi-digital hadronic calorimeter

    E-Print Network [OSTI]

    G. Baulieu; M. Bedjidian; K. Belkadhi; J. Berenguer; V. Boudry; P. Calabria; S. Callier; E. Calvo Almillo; S. Cap; L. Caponetto; C. Combaret; R. Cornat; E. Cortina Gil; B. de Callatay; F. Davin; C. de la Taille; R. Dellanegra; D. Delaunay; F. Doizon; F. Dulucq; A. Eynard; M-C. Fouz; F. Gastaldi; L. Germani; G. Grenier; Y. Haddad; R. Han; J-C. Ianigro; R. Kieffer; I. Laktineh; N. Lumb; K. Manai; S. Mannai; H. Mathez; L. Mirabito; J. Prast; J. Puerta Pelayo; M. Ruan; F. Schirra; N. Seguin-Moreau; A. Steen; W. Tromeur; M. Tytgat; M. Vander Donckt; G. Vouters; N. Zaganidis

    2015-06-15

    A large prototype of 1.3m3 was designed and built as a demonstrator of the semi-digital hadronic calorimeter (SDHCAL) concept proposed for the future ILC experiments. The prototype is a sampling hadronic calorimeter of 48 units. Each unit is built of an active layer made of 1m2 Glass Resistive Plate Chamber(GRPC) detector placed inside a cassette whose walls are made of stainless steel. The cassette contains also the electronics used to read out the GRPC detector. The lateral granularity of the active layer is provided by the electronics pick-up pads of 1cm2 each. The cassettes are inserted into a self-supporting mechanical structure built also of stainless steel plates which, with the cassettes walls, play the role of the absorber. The prototype was designed to be very compact and important efforts were made to minimize the number of services cables to optimize the efficiency of the Particle Flow Algorithm techniques to be used in the future ILC experiments. The different components of the SDHCAL prototype were studied individually and strict criteria were applied for the final selection of these components. Basic calibration procedures were performed after the prototype assembling. The prototype is the first of a series of new-generation detectors equipped with a power-pulsing mode intended to reduce the power consumption of this highly granular detector. A dedicated acquisition system was developed to deal with the output of more than 440000 electronics channels in both trigger and triggerless modes. After its completion in 2011, the prototype was commissioned using cosmic rays and particles beams at CERN.

  7. Iron Aerogel and Xerogel Catalysts for Fischer-Tropsch Synthesis of Diesel Fuel

    SciTech Connect (OSTI)

    Bali, S.; Huggins, F; Huffman, G; Ernst, R; Pugmire, R; Eyring, E

    2009-01-01

    Iron aerogels, potassium-doped iron aerogels, and potassium-doped iron xerogels have been synthesized and characterized and their catalytic activity in the Fischer-Tropsch (F-T) reaction has been studied. Iron aerogels and xerogels were synthesized by polycondensation of an ethanolic solution of iron(III) chloride hexahydrate with propylene oxide which acts as a proton scavenger for the initiation of hydrolysis and polycondensation. Potassium was incorporated in the iron aerogel and iron xerogel by adding aqueous K{sub 2}CO{sub 3} to the ethanolic solutions of the Fe(III) precursor prior to addition of propylene oxide. Fischer-Tropsch activities of the catalysts were tested in a fixed bed reactor at a pressure of 100 psi with a H{sub 2}:CO ratio of 2:1. Iron aerogels were found to be active for F-T synthesis, and their F-T activities increased on addition of a K containing promoter. Moessbauer spectroscopic data are consistent with an open, nonrigid iron(III) aerogel structure progressing to an iron carbide/metallic iron catalyst via agglomeration as the F-T synthesis proceeds in the course of a 35 h fixed bed reaction test.

  8. Use of bimodal carbon distribution in compacts for producing metallic iron nodules

    DOE Patents [OSTI]

    Iwasaki, Iwao

    2012-10-16

    A method for use in production of metallic iron nodules comprising providing a reducible mixture into a hearth furnace for the production of metallic iron nodules, where the reducible mixture comprises a quantity of reducible iron bearing material, a quantity of first carbonaceous reducing material of a size less than about 28 mesh of an amount between about 65 percent and about 95 percent of a stoichiometric amount necessary for complete iron reduction of the reducible iron bearing material, and a quantity of second carbonaceous reducing material with an average particle size greater than average particle size of the first carbonaceous reducing material and a size between about 3 mesh and about 48 mesh of an amount between about 20 percent and about 60 percent of a stoichiometric amount of necessary for complete iron reduction of the reducible iron bearing material.

  9. Use of bimodal carbon distribution in compacts for producing metallic iron nodules

    DOE Patents [OSTI]

    Iwasaki, Iwao

    2014-04-08

    A method for use in production of metallic iron nodules comprising providing a reducible mixture into a hearth furnace for the production of metallic iron nodules, where the reducible mixture comprises a quantity of reducible iron bearing material, a quantity of first carbonaceous reducing material of a size less than about 28 mesh of an amount between about 65 percent and about 95 percent of a stoichiometric amount necessary for complete iron reduction of the reducible iron bearing material, and a quantity of second carbonaceous reducing material with an average particle size greater than average particle size of the first carbonaceous reducing material and a size between about 3 mesh and about 48 mesh of an amount between about 20 percent and about 60 percent of a stoichiometric amount of necessary for complete iron reduction of the reducible iron bearing material.

  10. The world`s first commercial iron carbide plant

    SciTech Connect (OSTI)

    Prichard, L.C.; Schad, D.

    1995-12-01

    The paper traces the development of Nucor`s investigation of clean iron unit processes, namely, direct reduction, and the decision to build and operate the world`s first commercial iron carbide plant. They first investigated coal based processes since the US has abundant coal reserves, but found a variety of reasons for dropping the coal-based processes from further consideration. A natural gas based process was selected, but the failure to find economically priced gas supplies stopped the development of a US based venture. It was later found that Trinidad had economically priced and abundant supplies of natural gas, and the system of government, the use of English language, and geographic location were also ideal. The cost estimates required modification of the design, but the plant was begun in April, 1993. Start-up problems with the plant are also discussed. Production should commence shortly.

  11. Iron aluminide alloy container for solid oxide fuel cells

    DOE Patents [OSTI]

    Judkins, Roddie Reagan (Knoxville, TN); Singh, Prabhakar (Export, PA); Sikka, Vinod Kumar (Oak Ridge, TN)

    2000-01-01

    A container for fuel cells is made from an iron aluminide alloy. The container alloy preferably includes from about 13 to about 22 weight percent Al, from about 2 to about 8 weight percent Cr, from about 0.1 to about 4 weight percent M selected from Zr and Hf, from about 0.005 to about 0.5 weight percent B or from about 0.001 to about 1 weight percent C, and the balance Fe and incidental impurities. The iron aluminide container alloy is extremely resistant to corrosion and metal loss when exposed to dual reducing and oxidizing atmospheres at elevated temperatures. The alloy is particularly useful for containment vessels for solid oxide fuel cells, as a replacement for stainless steel alloys which are currently used.

  12. Iron aluminide useful as electrical resistance heating elements

    DOE Patents [OSTI]

    Sikka, V.K.; Deevi, S.C.; Fleischhauer, G.S.; Hajaligol, M.R.; Lilly, A.C. Jr.

    1997-04-15

    The invention relates generally to aluminum containing iron-base alloys useful as electrical resistance heating elements. The aluminum containing iron-base alloys have improved room temperature ductility, electrical resistivity, cyclic fatigue resistance, high temperature oxidation resistance, low and high temperature strength, and/or resistance to high temperature sagging. The alloy has an entirely ferritic microstructure which is free of austenite and includes, in weight %, over 4% Al, {<=}1% Cr and either {>=}0.05% Zr or ZrO{sub 2} stringers extending perpendicular to an exposed surface of the heating element or {>=}0.1% oxide dispersoid particles. The alloy can contain 14-32% Al, {<=}2% Ti, {<=}2% Mo, {<=}1% Zr, {<=}1% C, {<=}0.1% B, {<=}30% oxide dispersoid and/or electrically insulating or electrically conductive covalent ceramic particles, {<=}1% rare earth metal, {<=}1% oxygen, {<=}3% Cu, balance Fe. 64 figs.

  13. Synthesis of carbon-coated iron nanoparticles by detonation technique

    SciTech Connect (OSTI)

    Sun, Guilei, E-mail: sunguilei@126.com [Department of Safety Engineering, China Institute of Industrial Relations, Beijing 100037 (China)] [Department of Safety Engineering, China Institute of Industrial Relations, Beijing 100037 (China); Li, Xiaojie, E-mail: dalian03@vip.sina.com [State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Dalian University of Technology, Dalian 116023 (China)] [State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Dalian University of Technology, Dalian 116023 (China); Wang, Qiquan [Department of Safety Engineering, China Institute of Industrial Relations, Beijing 100037 (China)] [Department of Safety Engineering, China Institute of Industrial Relations, Beijing 100037 (China); Yan, Honghao [State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Dalian University of Technology, Dalian 116023 (China)] [State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Dalian University of Technology, Dalian 116023 (China)

    2010-05-15

    Carbon-coated iron nanoparticles were synthesized by detonating a mixture of ferrocene, naphthalene and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in an explosion vessel under low vacuum conditions (8.1 kPa). The RDX functioned as an energy source for the decomposition of ferrocene and naphthalene. The carbon-coated iron nanoparticles were formed as soot-like deposits on the inner surface of the reactor, which were characterized by XRD, TEM, HRTEM, Raman spectroscopy and vibrating sample magnetometer. And a portion of the detonation soot was treated with hydrochloric acid. The product was carbon-coated nanoparticles in perfect core-shell structures with graphitic shells and bcc-Fe cores. The detonation technique offers an energy-saving route to the synthesis of carbon-coated nanomaterials.

  14. Oxidation, carburization and/or sulfidation resistant iron aluminide alloy

    DOE Patents [OSTI]

    Sikka, Vinod K.; Deevi, Seetharama C.; Fleischhauer, Grier S.; Hajaligol, Mohammad R.; Lilly, Jr., A. Clifton

    2003-08-19

    The invention relates generally to aluminum containing iron-base alloys useful as electrical resistance heating elements. The aluminum containing iron-base alloys have improved room temperature ductility, electrical resistivity, cyclic fatigue resistance, high temperature oxidation resistance, low and high temperature strength, and/or resistance to high temperature sagging. The alloy has an entirely ferritic microstructure which is free of austenite and includes, in weight %, over 4% Al, .ltoreq.1% Cr and either .gtoreq.0.05% Zr or Zro.sub.2 stringers extending perpendicular to an exposed surface of the heating element or .gtoreq.0.1% oxide dispersoid particles. The alloy can contain 14-32% Al, .ltoreq.2% Ti, .ltoreq.2% Mo, .ltoreq.1% Zr, .ltoreq.1% C, .ltoreq.0.1% B. .ltoreq.30% oxide dispersoid and/or electrically insulating or electrically conductive covalent ceramic particles, .ltoreq.1% rare earth metal, .ltoreq.1% oxygen, .ltoreq.3% Cu, balance Fe.

  15. Iron aluminide useful as electrical resistance heating elements

    DOE Patents [OSTI]

    Sikka, Vinod K. (Oak Ridge, TN); Deevi, Seetharama C. (Oak Ridge, TN); Fleischhauer, Grier S. (Midlothian, VA); Hajaligol, Mohammad R. (Richmond, VA); Lilly, Jr., A. Clifton (Chesterfield, VA)

    1999-01-01

    The invention relates generally to aluminum containing iron-base alloys useful as electrical resistance heating elements. The aluminum containing iron-base alloys have improved room temperature ductility, electrical resistivity, cyclic fatigue resistance, high temperature oxidation resistance, low and high temperature strength, and/or resistance to high temperature sagging. The alloy has an entirely ferritic microstructure which is free of austenite and includes, in weight %, over 4% Al, .ltoreq.1% Cr and either .gtoreq.0.05% Zr or ZrO.sub.2 stringers extending perpendicular to an exposed surface of the heating element or .gtoreq.0.1% oxide dispersoid particles. The alloy can contain 14-32% Al, .ltoreq.2% Ti, .ltoreq.2% Mo, .ltoreq.1% Zr, .ltoreq.1% C, .ltoreq.0.1% B, .ltoreq.30% oxide dispersoid and/or electrically insulating or electrically conductive covalent ceramic particles, .ltoreq.1% rare earth metal, .ltoreq.1% oxygen, .ltoreq.3% Cu, balance Fe.

  16. Iron aluminide useful as electrical resistance heating elements

    DOE Patents [OSTI]

    Sikka, Vinod K. (Oak Ridge, TN); Deevi, Seetharama C. (Oak Ridge, TN); Fleischhauer, Grier S. (Midlothian, VA); Hajaligol, Mohammad R. (Richmond, VA); Lilly, Jr., A. Clifton (Chesterfield, VA)

    2001-01-01

    The invention relates generally to aluminum containing iron-base alloys useful as electrical resistance heating elements. The aluminum containing iron-base alloys have improved room temperature ductility, electrical resistivity, cyclic fatigue resistance, high temperature oxidation resistance, low and high temperature strength, and/or resistance to high temperature sagging. The alloy has an entirely ferritic microstructure which is free of austenite and includes, in weight %, over 4% Al, .ltoreq.1% Cr and either .gtoreq.0.05% Zr or ZrO.sub.2 stringers extending perpendicular to an exposed surface of the heating element or .gtoreq.0.1% oxide dispersoid particles. The alloy can contain 14-32% Al, .ltoreq.2% Ti, .ltoreq.2% Mo, .ltoreq.1% Zr, .ltoreq.1% C, .ltoreq.0.1% B, .ltoreq.30% oxide dispersoid and/or electrically insulating or electrically conductive covalent ceramic particles, .ltoreq.1% rare earth metal, .ltoreq.1% oxygen, .ltoreq.3% Cu, balance Fe.

  17. Iron aluminide alloys with improved properties for high temperature applications

    DOE Patents [OSTI]

    McKamey, Claudette G. (Knoxville, TN); Liu, Chain T. (Oak Ridge, TN)

    1990-01-01

    An improved iron aluminide alloy of the DO.sub.3 type that has increased room temperature ductility and improved high elevated temperature strength. The alloy system further is resistant to corrosive attack in the environments of advanced energy corrosion systems such as those using fossil fuels. The resultant alloy is relatively inexpensive as contrasted to nickel based and high nickel steels currently utilized for structural components. The alloy system consists essentially of 26-30 at. % aluminum, 0.5-10 at. % chromium, 0.02-0.3 at. % boron plus carbon, up to 2 at. % molybdenum, up to 1 at. % niobium, up to 0.5 at. % zirconium, up to 0.1 at. % yttrium, up to 0.5 at. % vanadium and the balance iron.

  18. Iron aluminide alloys with improved properties for high temperature applications

    DOE Patents [OSTI]

    McKamey, C.G.; Liu, C.T.

    1990-10-09

    An improved iron aluminide alloy of the DO[sub 3] type is described that has increased room temperature ductility and improved high elevated temperature strength. The alloy system further is resistant to corrosive attack in the environments of advanced energy conversion systems such as those using fossil fuels. The resultant alloy is relatively inexpensive as contrasted to nickel based and high nickel steels currently utilized for structural components. The alloy system consists essentially of 26--30 at. % aluminum, 0.5--10 at. % chromium, 0.02--0.3 at. % boron plus carbon, up to 2 at. % molybdenum, up to 1 at. % niobium, up to 0.5 at. % zirconium, up to 0.1 at. % yttrium, up to 0.5 at. % vanadium and the balance iron. 3 figs.

  19. TECHNOLOGY DEVELOPMENT FOR IRON FISCHER-TROPSCH CATALYSTS

    SciTech Connect (OSTI)

    Davis, B.H.

    1998-07-22

    The goal of the proposed work described in this Final Report was the development of iron-based Fischer-Tropsch catalysts that combined high activity, selectivity and life with physical robustness for slurry phase reactors that will produce either low-alpha or high-alpha products. The work described here has optimized the catalyst composition and pretreatment operation for a low-alpha catalyst. In parallel, work has been conducted to design a high-alpha iron catalyst that is suitable for slurry phase synthesis. Studies have been conducted to define the chemical phases present at various stages of the pretreatment and synthesis stages and to define the course of these changes. The oxidation/reduction cycles that are anticipated to occur in large, commercial reactors have been studied at the laboratory scale. Catalyst performance has been determined for catalysts synthesized in this program for activity, selectivity and aging characteristics.

  20. Method for heat treating iron-nickel-chromium alloy

    DOE Patents [OSTI]

    Not Available

    1980-04-03

    A method is described for heat treating an age-hardenable iron-nickel-chromium alloy to obtain a morphology of the gamma-double prime phase enveloping the gamma-prime, the alloy consisting essentially of about 25 to 45% nickel, 10 to 16% chromium, 1.5 to 3% of an element selected from the group consisting of molybdenum and niobium, about 2% titanium, about 3% aluminum, and the remainder substantially all iron. To obtain optimum results, the alloy is heated to a temperature of 1025 to 1075/sup 0/C for 2 to 5 minutes, cold-worked about 20 to 60%, aged at a temperature of about 775/sup 0/C for 8 hours followed by an air-cool, and then heated to a temperature in the range of 650 to 700/sup 0/C for 2 hours followed by an air-cool.

  1. Iron beam acceleration using direct plasma injection scheme

    SciTech Connect (OSTI)

    Okamura, M.; Kanesue, T.; Yamamoto, T.; Fuwa, Y.; RIKEN, Wako, Saitama 351-0198

    2014-02-15

    A new set of vanes of radio frequency quadrupole (RFQ) accelerator was commissioned using highly charged iron beam. To supply high intensity heavy ion beams to the RFQ, direct plasma injection scheme (DPIS) with a confinement solenoid was adopted. One of the difficulties to utilize the combination of DPIS and a solenoid field is a complexity of electro magnetic field at the beam extraction region, since biasing high static electric field for ion extraction, RFQ focusing field, and the solenoid magnetic field fill the same space simultaneously. To mitigate the complexity, a newly designed magnetic field clamps were used. The intense iron beam was observed with bunched structure and the total accelerated current reached 2.5 nC.

  2. A modeling assessment of the interplay between aeolian iron fluxes and iron-binding ligands in controlling carbon dioxide fluctuations during

    E-Print Network [OSTI]

    Fortunat, Joos

    in controlling carbon dioxide fluctuations during Antarctic warm events Payal Parekh,1 Fortunat Joos,1 between aeolian iron fluxes and iron-binding ligands in controlling carbon dioxide fluctuations during decreasing atmospheric carbon dioxide (CO2). This is consistent with evidence of an increase in the aeolian

  3. Modeling non-heme iron proteins and Yukiko Mishina

    E-Print Network [OSTI]

    He, Chuan

    with the use of terphenyl-based carboxylate ligands and the development of several iron-based reagents@uchicago.edu Current Opinion in Chemical Biology 2004, 8:201­208 This review comes from a themed issue on Bioinorganic,4,8,11-tetraazacyclotetradecane MMO methane monooxygenase OTf CF3SO3 PaPy3H N-[N,N-bis(2-pyridylmethyl)aminoethyl]-2

  4. Bifunctional air electrodes containing elemental iron powder charging additive

    DOE Patents [OSTI]

    Liu, Chia-tsun (Monroeville, PA); Demczyk, Brian G. (Rostrover Township, Westmoreland County, PA); Gongaware, Paul R. (Penn Township, Westmoreland County, PA)

    1982-01-01

    A bifunctional air electrode for use in electrochemical energy cells is made, comprising a hydrophilic layer and a hydrophobic layer, where the hydrophilic layer essentially comprises a hydrophilic composite which includes: (i) carbon; (ii) elemental iron particles having a particle size of between about 25 microns and about 700 microns diameter; (iii) an oxygen evolution material; (iv) a nonwetting agent; and (v) a catalyst, where at least one current collector is formed into said composite.

  5. Low resistivity contact to iron-pnictide superconductors

    DOE Patents [OSTI]

    Tanatar, Makariy; Prozorov, Ruslan; Ni, Ni; Bud'ko, Sergey; Canfield, Paul

    2013-05-28

    Method of making a low resistivity electrical connection between an electrical conductor and an iron pnictide superconductor involves connecting the electrical conductor and superconductor using a tin or tin-based material therebetween, such as using a tin or tin-based solder. The superconductor can be based on doped AFe.sub.2As.sub.2, where A can be Ca, Sr, Ba, Eu or combinations thereof for purposes of illustration only.

  6. Technology development for iron F-T catalysts. Final report

    SciTech Connect (OSTI)

    Frame, R.R.; Gala, H.B.

    1994-08-01

    The objectives of this work were twofold. The first objective was to design and construct a pilot plant for preparing precipitated iron oxide F-T precursors and demonstrate that the rate of production from this plant is equivalent to 100 lbs/day of dried metal oxide. Secondly, these precipitates were to be used to prepare catalysts capable of achieving 88% CO + H{sub 2} conversion with {le} 5 mole percent selectivity to methane + ethane.

  7. Pressure Effects on Two Superconducting Iron-based Families

    SciTech Connect (OSTI)

    Safa-Sefat, Athena [ORNL

    2011-01-01

    Insight into the mechanism of high-temperature superconductivity can be gained by pressure-dependent studies of structural, thermodynamics and transport data. The role of pressure may be complicated by the level of hydrostaticity. High-pressure studies on two iron-based families of RFeAsO (R = rare-earth metals) and AFe{sub 2}As{sub 2} (A = alkaline-earth metals) are reviewed here.

  8. Mountain Iron, Minnesota: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History ViewMayo, Maryland: EnergyInformationOliver, Pennsylvania: Energy ResourcesOhio:City,Iron,

  9. Coal Fly Ash as a Source of Iron in Atmospheric Dust

    SciTech Connect (OSTI)

    Chen, Haihan; Laskin, Alexander; Baltrusaitis, Jonas; Gorski, Christopher A.; Scherer, Michelle; Grassian, Vicki H.

    2012-01-18

    Anthropogenic coal fly ash aerosols may represent a significant source of bioavailable iron in the open ocean. Few measurements have been made to compare the solubility of atmospheric iron from anthropogenic aerosols and other sources. We report an investigation of the iron dissolution of three fly ash samples in acidic aqueous solutions and compare the solubilities with that of Arizona test dust, a reference material of mineral dust. The effects of pH, cloud processing, and solar irradiation on Fe solubility were explored. Similar to previously reported results on mineral dust, iron in aluminosilicate phases provide predominant dissolved iron compared with iron in oxides. Iron solubility of fly ash is higher than Arizona test dust, especially at the higher pH conditions investigated. Simulated atmospheric processing elevates iron solubility due to significant changes in the morphology aluminosilicate glass, a dominantly material in fly ash particle. Iron continuously releases into the aqueous solution as fly ash particles break up into smaller fragments. The assessment of dissolved atmospheric iron deposition fluxes, and their effect on the biogeochemistry at ocean surface should be constrained by taking into account the source, environment pH, Fe speciation, and solar radiation.

  10. Blood and hair lead in children with different extents of iron deficiency in Karachi

    SciTech Connect (OSTI)

    Ataur Rahman, Muhammad; Rahman, Bushra [Karachi Institute of Biotechnology and Genetic Engineering, University of Karachi, Karachi-75270 (Pakistan)] [Karachi Institute of Biotechnology and Genetic Engineering, University of Karachi, Karachi-75270 (Pakistan); Saeed Ahmad, Muhammad [School of Healthcare Science, Manchester Metropolitan University, Manchester M1 5GD (United Kingdom)] [School of Healthcare Science, Manchester Metropolitan University, Manchester M1 5GD (United Kingdom); Blann, Andrew [Department of Medicine, City Hospital, Birmingham B18 7QH, United Kingdom. (United Kingdom)] [Department of Medicine, City Hospital, Birmingham B18 7QH, United Kingdom. (United Kingdom); Ahmed, Nessar, E-mail: N.Ahmed@mmu.ac.uk [School of Healthcare Science, Manchester Metropolitan University, Manchester M1 5GD (United Kingdom)] [School of Healthcare Science, Manchester Metropolitan University, Manchester M1 5GD (United Kingdom)

    2012-10-15

    Childhood iron deficiency has a high incidence in Pakistan. Some but not all studies have shown that dietary iron deficiency may cause increased absorption of lead as both compete for the same transporters in the small intestine. Therefore, children in Pakistan, residing in heavily polluted cities like Karachi may be prone to lead poisoning. This hypothesis was tested by investigating blood and hair lead concentrations in children from Karachi who were divided into four groups of iron status; normal, borderline iron deficiency, iron deficiency and iron deficiency anaemia. A prospective observational study was conducted where 269 children were categorized into four groups of iron status using the World Health Organization criteria and one based on soluble transferrin receptor measurements. Blood iron status was determined using a full blood count, serum iron, ferritin, transferrin saturation and soluble transferrin receptor measurements. Blood lead was determined by graphite atomic absorption spectroscopy, whereas hair lead was assessed using an inductively coupled plasma atomic emission spectroscopy technique. Blood lead concentrations were significantly higher in children with iron deficiency anaemia (mean [95% confidence intervals] were 24.9 [22.6-27.2] {mu}g/dL) compared to those with normal iron status (19.1 [16.8-21.4] {mu}g/dL) using WHO criteria. In contrast, hair lead content was not significantly different in children of different iron status. Our findings reinforce the importance of not only reducing environmental lead pollution but also the development of national health strategies to reduce childhood iron deficiency in Pakistan.

  11. Photoionization Modeling and the K Lines of Iron

    E-Print Network [OSTI]

    T. R. Kallman; P. Palmeri; M. A. Bautista; C. Mendoza; J. H. Krolik

    2004-05-11

    We calculate the efficiency of iron K line emission and iron K absorption in photoionized models using a new set of atomic data. These data are more comprehensive than those previously applied to the modeling of iron K lines from photoionized gases, and allow us to systematically examine the behavior of the properties of line emission and absorption as a function of the ionization parameter, density and column density of model constant density clouds. We show that, for example, the net fluorescence yield for the highly charged ions is sensitive to the level population distribution produced by photoionization, and these yields are generally smaller than those predicted assuming the population is according to statistical weight. We demonstrate that the effects of the many strongly damped resonances below the K ionization thresholds conspire to smear the edge, thereby potentially affecting the astrophysical interpretation of absorption features in the 7-9 keV energy band. We show that the centroid of the ensemble of K$\\alpha$ lines, the K$\\beta$ energy, and the ratio of the K$\\alpha_1$ to K$\\alpha_2$ components are all diagnostics of the ionization parameter of our model slabs

  12. Iron line reverberation mapping with Constellation-X

    E-Print Network [OSTI]

    A. J. Young; C. S. Reynolds

    1999-10-08

    The broad X-ray iron line seen in the spectra of many AGN is thought to originate from the inner regions of the putative black hole accretion disk, and hence provides a rare probe of that central region. In principle, future high throughput X-ray spectrometers should be able to examine the temporal response of this fluorescent line to flares in the X-ray continuum source (which energizes this emission line) - i.e. iron line reverberation mapping will be possible. It has been previously found that there are robust reverberation signatures of the black hole spin, mass and the X-ray flare location above the accretion disk. Here, we simulate observations of a bright Seyfert nucleus with the proposed NASA mission Constellation-X and demonstrate the feasibility of detecting these reverberation signatures with this mission. Hence, starting with XMM in 1999, and maturing with Constellation-X in c2010, iron line reverberation will open a new window on the innermost regions of AGN.

  13. Mineral ecophysiological evidence for microbial activity in banded iron formation

    SciTech Connect (OSTI)

    Li, Dr. Yi-Liang [University of Tennessee, Knoxville (UTK); Konhauser, Dr, Kurt [University of Alberta; Cole, David R [ORNL; Phelps, Tommy Joe [ORNL

    2011-01-01

    The phosphorus composition of banded-iron formations (BIFs) has been used as a proxy for Precambrian seawater composition and the paleoeredox state of Earth's surface environment. However, it is unclear whether the phosphorus in BIFs originally entered the sediment as a sorbed component of the iron oxyhydroxide particles, or whether it was incorporated into the biomass of marine phytoplankton. We conducted high-resolution mineral analyses and report here the first detection of an Fe(III) acetate salt, as well as nanocrystals of apatite in association with magnetite, in the 2.48 Ga Dales Gorge Member of the Brockman Iron Formation (a BIF), Hamersley, Western Australia. The clusters of apatite are similar in size and morphology to biogenic apatite crystals resulting from biomass decay in Phanerozoic marine sediments, while the formation of an Fe(III) acetate salt and magnetite not only implies the original presence of biomass in the BIF sediments, but also that organic carbon likely served as an electron donor during bacterial Fe(III) reduction. This study is important because it suggests that phytoplankton may have played a key role in the transfer of phosphorus (and other trace elements) from the photic zone to the seafloor.

  14. An Atomistic study of Helium Resolution in bcc Iron

    SciTech Connect (OSTI)

    Stoller, Roger E [ORNL; Stewart, David M [ORNL

    2011-01-01

    The evolution of gas-stabilized bubbles in irradiated materials can be a significant factor in the microstructural processes that lead to mechanical property and dimensional changes in structural materials exposed to high-energy neutrons. Helium generation and accumulation is particularly important under DT fusion irradiation conditions. Although the process of ballistic resolutioning of gas from bubbles has been long-discussed in the literature, there have been few computational studies of this mechanism. Resolutioning could limit bubble growth by ejecting gas atoms back into the metal matrix. A detailed atomistic study of ballistic He resolutioning from bubbles in bcc iron has been carried out using molecular dynamics. A newly-developed Fe-He interatomic potential was employed, with the iron matrix described by the potential of Ackland and co-workers from 1997. The primary variables examined were: irradiation temperature (100 and 600K), iron knock-on atom energy (5 and 20 keV), bubble radius (~0.5 and 1.0 nm), and He-to-vacancy ratio in the bubble (0.25, 0.5 and 1.0) in order to obtain an assessment of this dynamic resolutioning mechanism. The results presented here focus on the 5 keV cascades which indicate a modest, but potentially significant level of He removal by this process.

  15. The development of precipitated iron catalysts with improved stability

    SciTech Connect (OSTI)

    Not Available

    1990-01-01

    The goal of this program is to identify the chemical principles governing the deactivation of precipitated iron catalysts during Fischer-Tropsch synthesis and to use these chemical principles in the design of catalysts suitable for slurry reactors. This report covers testing an iron catalyst. During the last quarter, a new precipitated iron catalyst was prepared and tested in the slurry autoclave reactor at various conditions. This catalyst did not noticeably deactivate during 1250 hours of testing. This quarter, the test was extended to include performance evaluations at different conversion levels ranging from 35 to 88% at 265 and 275{degree}C. The conversion levels were varied by changing the feed rate. The catalytic performance at different conversion intervals was then integrated to approximately predict performance in a bubble column reactor. The run was shut down at the end of 1996 hours because of a 24-hour-power outage. When the power was back on, the run was restarted from room temperature. Catalytic performance during the first 300 hours after the restart-up was monitored. Overall product distributions are being tabulated as analytical laboratory data are obtained. 34 figs., 3 tabs.

  16. Iron (III) Matrix Effects on Mineralization and Immobilization of Actinides

    SciTech Connect (OSTI)

    Cynthia-May S. Gong; Tyler A. Sullens; Kenneth R. Czerwinski

    2006-01-01

    Abstract - A number of models for the Yucca Mountain Project nuclear waste repository use studies of actinide sorption onto well-defined iron hydroxide materials. In the case of a waste containment leak, however, a complex interaction between dissolved waste forms and failed containment vessel components can lead to immediate precipitation of migratory iron and uranyl in the silicate rich near-field environment. Use of the Fe(III) and UO22+ complexing agent acetohydroxamic acid (AHA) as a colorimetric agent for visible spectrophotometry is well-known. Using the second derivative of these spectra a distinct shift in iron complexation in the presence of silicate is seen that is not seen with uranyl or alone. Silica also decreases the ability of uranyl and ferric solutions to absorb hydroxide, hastening precipitation. These ferric silicate precipitates are highly amorphous and soluble. Precipitates formed in the presence of uranyl below ~1 mol% exhibit lower solubility than precipitates from up to 50 mol % and of uranyl silicates alone.

  17. Deactivation by carbon of iron catalysts for indirect liquefaction

    SciTech Connect (OSTI)

    Bartholomew, C.H.

    1991-01-10

    Although promoted cobalt and iron catalysts for Fischer-Tropsch (FT) synthesis of gasoline feedstock were first developed more than three decades ago, a major technical problem still limiting the commercial use of these catalysts today is carbon deactivation. This report describes recent progress in a fundamental, three-year investigation of carbon formation and its effects on the activity and selectivity of promoted iron catalysts for FT synthesis, the objectives of which are to: determine rates and mechanisms of carbon deactivation of unsupported Fe and Fe/K catalysts during CO hydrogenation over a range of CO concentrations, CO:H{sub 2} ratios, and temperatures; and model the rates of deactivation of the same catalysts in fixed-bed reactors. To accomplish the above objectives, the project is divided into the following tasks: (1) determine the kinetics of reaction and of carbon deactivation during CO hydrogenation on Fe and Fe/K catalysts coated on monolith bodies. (2) Determine the reactivities and types of carbon deposited during reaction on the same catalysts from temperature-programmed-surface-reaction spectroscopy (TPSR) and transmission electron microscopy (TEM). Determine the types of iron carbides formed at various temperatures and H{sub 2}/CO ratios using x-ray diffraction and Moessbauer spectroscopy. (3) Develop mathematical deactivation models which include heat and mass transport contributions for FT synthesis is packed-bed reactors. Progress to date is described. 48 refs., 3 figs., 1 tab.

  18. Positive field-cooled dc susceptibility in granular superconductors interpreted through numerical simulations on a simple Josephson-junction-array model

    SciTech Connect (OSTI)

    Auletta, C.; Raiconi, G.; De Luca, R.; Pace, S.

    1995-05-01

    We have performed numerical simulations of a field-cooled dc susceptibility experiment carried out for granular superconductors by modeling these systems with a simple Josephson-junction array proposed by the authors. By this analysis the temperature dependence of the positive field-cooled susceptibility at very low values of the applied magnetic field, observed by Braunisch {ital et} {ital al}. [Phys. Rev. Lett. 68, 1908 (1992)] for some ceramic superonductors, has been reproduced and interpreted.

  19. Model atmospheres and X-ray spectra of iron-rich bursting neutron stars. II. Iron rich Comptonized Spectra

    E-Print Network [OSTI]

    A. Majczyna; J. Madej; P. C. Joss; A. Rozanska

    2004-12-28

    This paper presents the set of plane-parallel model atmosphere equations for a very hot neutron star (X-ray burst source). The model equations assume both hydrostatic and radiative equilibrium, and the equation of state of an ideal gas in local thermodynamic equilibrium (LTE). The equation of radiative transfer includes terms describing Compton scattering of photons on free electrons in fully relativistic thermal motion, for photon energies approaching m_e *c^2. Model equations take into account many bound-free and free-free energy-dependent opacities of hydrogen, helium, and the iron ions, and also a dozen bound-bound opacities for the highest ions of iron. We solve model equations by partial linearisation and the technique of variable Eddington factors. Large grid of H-He-Fe model atmospheres of X-ray burst sources has been computed for 10^7 neutron stars from observational data.

  20. Mössbauer study of metallic iron and iron oxide nanoparticles having environmental purifying ability

    SciTech Connect (OSTI)

    Kubuki, Shiro Watanabe, Yuka Akiyama, Kazuhiko; Risti?, Mira; Krehula, Stjepko; Homonnay, Zoltán; Kuzmann, Ern?; Nishida, Tetsuaki

    2014-10-27

    A relationship between local structure and methylene blue (MB) decomposing ability of nanoparticles (NPs) of metallic iron (Fe{sup 0}) and maghemite (??Fe{sub 2}O{sub 3}) was investigated by {sup 57}Fe Mössbauer spectroscopy, X-ray diffractometry and UV-visible light absorption spectroscopy. ??Fe{sub 2}O{sub 3} NPs were successfully prepared by mixing (NH{sub 4}){sub 2}Fe(SO{sub 4}){sub 2}?6H{sub 2}O (Mohr's salt) and (NH{sub 4}){sub 3}Fe(C{sub 2}O{sub 4}){sub 3}?3H{sub 2}O aqueous solution at 30 °C for 1 h, while those of Fe{sup 0} were obtained by the reduction of Mohr's salt with NaBH{sub 4}. From the Scherrer's equation, the smallest crystallite sizes of ??Fe{sub 2}O{sub 3} NPs and Fe{sup 0} NPs were determined to be 9.7 and 1.5 nm, respectively. {sup 57}Fe Mössbauer spectrum of ??Fe{sub 2}O{sub 3} NPs consists of a relaxed sextet with isomer shift (?) of 0.33{sub ±0.01} mm s{sup ?1}, internal magnetic field (H{sub int}) of 25.8{sub ±0.5} T, and linewidth (?) of 0.62{sub ±0.04} mm s{sup ?1}. {sup 57}Fe Mössbauer spectrum of Fe{sup 0} NP is mainly composed of a sextet having ?, ?, and H{sub int} of 0.00{sub ±0.01} mm s{sup ?1} 0.45{sub ±0.01} mm s{sup ?1}, and 22.8{sub ±0.1} T, respectively. A bleaching test of the mixture of Fe{sup 0} and ??Fe{sub 2}O{sub 3} NPs (3:7 ratio, 100 mg) in MB aqueous solution (20 mL) for 6 h showed a remarkable decrease of MB concentration with the first-order rate constant (k{sub MB}) of 6.7 × 10{sup ?1} h{sup ?1}. This value is larger than that obtained for the bleaching test using bulk Fe{sup 0}+??Fe{sub 2}O{sub 3} (3:7) mixture (k{sub MB}?=?6.5×10{sup ?3}h{sup ?1}). These results prove that MB decomposing ability is enhanced by the NPs mixture of Fe{sub 0} and ??Fe{sub 2}O{sub 3}.