Sample records for granular zero-valent iron

  1. Mineral Precipitation Upgradient from a Zero-Valent Iron Permeable...

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

    Abstract: Core samples taken from a zero-valent iron permeable reactive barrier (ZVI PRB) at Cornhusker Army Ammunition Plant, Nebraska, were analyzed for physical and chemical...

  2. Demonstration of Combined Zero-Valent Iron and Electrical Resistance...

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

    and M Oostrom.2011."Demonstration of Combined Zero-Valent Iron and Electrical Resistance Heating for In Situ Trichloroethene Remediation."Environmental Science & Technology...

  3. Assessing Arsenic Removal By Zero-Valent Iron Under

    E-Print Network [OSTI]

    6 8 10 12 14 ­.5 0 .5 1 pH Eh(volts) SO4 -- HS - H2S(aq) HSO4 - 20°C Dell Fri Feb 08 2008 DiagramSO4Assessing Arsenic Removal By Zero-Valent Iron Under Various Water Quality Conditions Paul Pepler and operate. #12;7 Best Available Technologies for As Removal (USEPA 2003) Ion exchange Activated alumina

  4. 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

  5. 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

    2004-03-31T23:59:59.000Z

    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.

  6. Sulfur-Modified Zero-Valent Iron for Remediation Applications at DOE Sites - 13600

    SciTech Connect (OSTI)

    Fogwell, Thomas W. [Fogwell Consulting, P.O. Box 20221, Piedmont, CA 94620 (United States)] [Fogwell Consulting, P.O. Box 20221, Piedmont, CA 94620 (United States); Santina, Pete [SMI-PS, Inc., 2073 Prado Vista, Lincoln, CA 95648 (United States)] [SMI-PS, Inc., 2073 Prado Vista, Lincoln, CA 95648 (United States)

    2013-07-01T23:59:59.000Z

    Many DOE remediation sites have chemicals of concern that are compounds in higher oxidation states, which make them both more mobile and more toxic. The chemical reduction of these compounds both prevents the migration of these chemicals and in some cases reduces the toxicity. It has also been shown that zero-valent iron is a very effective substance to use in reducing oxygenated compounds in various treatment processes. These have included the treatment of halogenated hydrocarbons in the form volatile organic compounds used as solvents and pesticides. Zero-valent iron has also been used to reduce various oxidized metals such as chromium, arsenic, and mercury in order to immobilize them, decrease their toxicity, and prevent further transport. In addition, it has been used to immobilize or break down other non-metallic species such as selenium compounds and nitrates. Of particular interest at several DOE remediation sites is the fact that zero-valent iron is very effective in immobilizing several radioactive metals which are mobile in their oxidized states. These include both technetium and uranium. The main difficulty in using zero-valent iron has been its tendency to become inactive after relatively short periods of time. While it is advantageous to have the zero-valent iron particles as porous as possible in order to provide maximum surface area for reactions to take place, these pores can become clogged when the iron is oxidized. This is due to the fact that ferric oxide has a greater volume for a given mass than metallic iron. When the surfaces of the iron particles oxidize to ferric oxide, the pores become narrower and will eventually shut. In order to minimize the degradation of the chemical activity of the iron due to this process, a modification of zero-valent iron has been developed which prevents or slows this process, which decreases its effectiveness. It is called sulfur-modified iron, and it has been produced in high purity for applications in municipal water treatment applications. Sulfur-modified iron has been found to not only be an extremely economical treatment technology for municipal water supplies, where very large quantities of water must be treated economically, but it has also been demonstrated to immobilize technetium. It has the added benefit of eliminating several other harmful chemicals in water supplies. These include arsenic and selenium. In one large-scale evaluation study an integrated system implemented chemical reduction of nitrate with sulfur-modified iron followed by filtration for arsenic removal. The sulfur-modified iron that was used was an iron-based granular medium that has been commercially developed for the removal of nitrate, co-contaminants including uranium, vanadium and chromium, and other compounds from water. The independent study concluded that 'It is foreseen that the greatest benefit of this technology (sulfur-modified iron) is that it does not produce a costly brine stream as do the currently accepted nitrate removal technologies of ion exchange and reverse osmosis. This investigation confirmed that nitrate reduction via sulfur-modified iron is independent of the hydraulic loading rate. Future sulfur-modified iron treatment systems can be designed without restriction of the reactor vessel dimensions. Future vessels can be adapted to existing site constraints without being limited to height-to-width ratios that would exist if nitrate reduction were to depend on hydraulic loading rate'. Sulfur-modified iron was studied by the Pacific Northwest National Laboratory (PNNL) for its effectiveness in the reduction and permanent sequestration of technetium. The testing was done using Hanford Site groundwater together with sediment. The report stated, 'Under reducing conditions, TcO{sub 4} is readily reduced to TcIV, which forms highly insoluble oxides such at TcO{sub 2}.nH{sub 2}O. However, (re)oxidation of TcIV oxides can lead to remobilization. Under sulfidogenic conditions, most TcIV will be reduced and immobilized as Tc{sub 2}S{sub 7}, which is less readily re-mobilized, ev

  7. 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

    2014-11-12T23:59:59.000Z

    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...

  8. Zero Valent Iron: Impact of Anions Present during Synthesis on...

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

    iron nanoparticles was quantified by monitoring the kinetics as well as products of carbon tetrachloride reduction, and significant differences in reactivity and chloroform...

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

    E-Print Network [OSTI]

    Malla, Deepak Babu

    1997-01-01T23:59:59.000Z

    and in combination. All three target contaminants were effectively reduced by both iron (Feo) and palladized iron (Pd/Fe'). However, the rate of reduction by Pd/Fe' was found to be much faster than that by Feo. The reduction of all the contaminants in mixed waste...

  10. 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.

    2009-06-01T23:59:59.000Z

    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.

  11. Mineral Precipitation Upgradient from a Zero-Valent Iron Permeable Reactive Barrier

    SciTech Connect (OSTI)

    Johnson, R. L.; Thoms, R. B.; Johnson, R. O.; Nurmi, J. T.; Tratnyek, Paul G.

    2008-07-01T23:59:59.000Z

    Core samples taken from a zero-valent iron permeable reactive barrier (ZVI PRB) at Cornhusker Army Ammunition Plant, Nebraska, were analyzed for physical and chemical characteristics. Precipitates containing iron and sulfide were present at much higher concentrations in native aquifer materials just upgradient of the PRB than in the PRB itself. Sulfur mass balance on core solids coupled with trends in ground water sulfate concentrations indicates that the average ground water flow after 20 months of PRB operation was approximately twenty fold less than the regional ground water velocity. Transport and reaction modeling of the aquifer PRB interface suggests that, at the calculated velocity, both iron and hydrogen could diffuse upgradient against ground water flow and thereby contribute to precipitation in the native aquifer materials. The initial hydraulic conductivity (K) of the native materials is less than that of the PRB and, given the observed precipitation in the upgradient native materials, it is likely that K reduction occurred upgradient to rather than within the PRB. Although not directly implicated, guar gum used during installation of the PRB is believed to have played a role in the precipitation and flow reduction processes by enhancing microbial activity.

  12. Zero-Valent Iron Permeable Reactive Barriers: A Review of Performance

    SciTech Connect (OSTI)

    Korte, NE

    2001-06-11T23:59:59.000Z

    This report briefly reviews issues regarding the implementation of the zero-valent iron permeable reactive barrier (PRB) technology at sites managed by the U.S. Department of Energy (DOE). Initially, the PRB technology, using zero-valent iron for the reactive media, was received with great enthusiasm, and DOE invested millions of dollars testing and implementing PRBs. Recently, a negative perception of the technology has been building. This perception is based on the failure of some deployments to satisfy goals for treatment and operating expenses. The purpose of this report, therefore, is to suggest reasons for the problems that have been encountered and to recommend whether DOE should invest in additional research and deployments. The principal conclusion of this review is that the most significant problems have been the result of insufficient characterization, which resulted in poor engineering implementation. Although there are legitimate concerns regarding the longevity of the reactive media, the ability of zero-valent iron to reduce certain chlorinated hydrocarbons and to immobilize certain metals and radionuclides is well documented. The primary problem encountered at some DOE full-scale deployments has been an inadequate assessment of site hydrology, which resulted in misapplication of the technology. The result is PRBs with higher than expected flow velocities and/or incomplete plume capture. A review of the literature reveals that cautions regarding subsurface heterogeneity were published several years prior to the full-scale implementations. Nevertheless, design and construction have typically been undertaken as if the subsurface was homogeneous. More recently published literature has demonstrated that hydraulic heterogeneity can cause so much uncertainty in performance that use of a passive PRB is precluded. Thus, the primary conclusion of this review is that more attention must be given to site-specific issues. Indeed, the use of a passive PRB requires an unusually comprehensive hydrologic characterization so that the design can be based on a thorough understanding of subsurface heterogeneity rather than on average values for hydraulic parameters. Scientists and engineers are capable of conducting the level of investigation required. However, design costs will increase, and the pre-design field work may demonstrate that a passive PRB is not suitable for a particular site. In such cases, an option to consider is hydraulic augmentation, such as pumping (in which the system is no longer passive) or gravity flow from drains. In these circumstances, operation of the treatment media is under known hydraulic conditions. These systems typically contain the treatment media in a vault or in drums. Most of the media problems in such systems have been related to the exclusion of air and can be addressed by better engineering design or by frequent maintenance. Finally, a number of outstanding issues require resolution for further application of this technology. Of particular interest to DOE is resolving the removal mechanisms for uranium and technetium. Few data are available for the latter, and for the former, the technical literature is contradictory. Determining the mechanisms has long-term cost implications; engineers must consider whether it is appropriate to remove or simply abandon a barrier that is no longer functioning. Other issues that are unresolved include determining how hydraulic performance is affected by the emplacement method and quantifying the effects of varying groundwater types on barrier longevity.

  13. Modelling the remediation of contaminated groundwater using zero-valent iron barrier

    SciTech Connect (OSTI)

    Kwong, S.; Small, J.; Tahar, B. [Nexia Solutions Ltd., Hinton House, Risley, Warrington, WA (United Kingdom)

    2007-07-01T23:59:59.000Z

    This paper presents results of modelling studies on remediation of groundwater contaminated with uranium using a zero-valent iron permeable reactive barrier (ZVI PRB) at the U.S. Oak Ridge Y-12 site that are used to establish modelling techniques that are of value to other sites such as in the UK. A systematic modelling methodology has been developed to study the problem by using a suite of modelling tools. Firstly a conceptual basis of the main chemical processes representing the remediation of uranium by the ZVI PRB is developed. Two main effects involving reduction and corrosion have been identified as being relevant for the remediation processes. These are then formulated and implemented using the reactive chemical model PHREEQC to provide underpinning chemical input parameters for subsequent reactive solute transport modelling using the TRAFFIC and PHAST codes. Initial results shows that modelling can be a very cost-effective means to study the hydrogeological and geochemical processes involved and to aid understanding of the remediation concept. The modelling approaches presented and lessons learnt are thought to be relevant to other cases of contaminated land study and are likely to be of value to site management concepts which consider on-site disposal of contaminated soils and materials. (authors)

  14. Degradation of carbon tetrachloride in the presence of zero-valent iron.

    SciTech Connect (OSTI)

    Alvarado, J. S.; Rose, C.; LaFreniere, L.; Environmental Science Division

    2010-01-01T23:59:59.000Z

    Efforts to achieve the decomposition of carbon tetrachloride through anaerobic and aerobic bioremediation and chemical transformation have met with limited success because of the conditions required and the formation of hazardous intermediates. Recently, particles of zero-valent iron (ZVI) have been used with limited success for in situ remediation of carbon tetrachloride. We studied a modified microparticulate product that combines controlled-release carbon with ZVI for stimulation of in situ chemical reduction of persistent organic compounds in groundwater. With this product, a number of physical, chemical, and microbiological processes were combined to create very strongly reducing conditions that stimulate rapid, complete dechlorination of organic solvents. In principle, the organic component of ZVI microparticles is nutrient rich and hydrophilic and has high surface area capable of supporting the growth of bacteria in the groundwater environment. In our experiments, we found that as the bacteria grew, oxygen was consumed, and the redox potential decreased to values reaching -600 mV. The small modified ZVI particles provide substantial reactive surface area that, in these conditions, directly stimulates chemical dechlorination and cleanup of the contaminated area without accumulation of undesirable breakdown products. The objective of this work was to evaluate the effectiveness of ZVI microparticles in reducing carbon tetrachloride under laboratory and field conditions. Changes in concentrations and in chemical and physical parameters were monitored to determine the role of the organic products in the reductive dechlorination reaction. Laboratory and field studies are presented.

  15. Impact of sample preparation on mineralogical analysis of zero-valent iron reactive barrier materials

    SciTech Connect (OSTI)

    Phillips, Debra Helen [ORNL; Gu, Baohua [ORNL; Watson, David B [ORNL; Roh, Yul [ORNL

    2003-03-01T23:59:59.000Z

    Permeable reactive barriers (PRBs) of zero-valent iron (Fe{sup 0}) are increasingly being used to remediate contaminated ground water. Corrosion of Fe{sup 0} filings and the formation of precipitates can occur when the PRB material comes in contact with ground water and may reduce the lifespan and effectiveness of the barrier. At present, there are no routine procedures for preparing and analyzing the mineral precipitates from Fe{sup 0} PRB material. These procedures are needed because mineralogical composition of corrosion products used to interpret the barrier processes can change with iron oxidation and sample preparation. The objectives of this study were (i) to investigate a method of preparing Fe{sup 0} reactive barrier material for mineralogical analysis by X-ray diffraction (XRD), and (ii) to identify Fe mineral phases and rates of transformations induced by different mineralogical preparation techniques. Materials from an in situ Fe{sup 0} PRB were collected by undisturbed coring and processed for XRD analysis after different times since sampling for three size fractions and by various drying treatments. We found that whole-sample preparation for analysis was necessary because mineral precipitates occurred within the PRB material in different size fractions of the samples. Green rusts quickly disappeared from acetone-dried samples and were not present in air-dried and oven-dried samples. Maghemite/magnetite content increased over time and in oven-dried samples, especially after heating to 105 C. We conclude that care must be taken during sample preparation of Fe{sup 0} PRB material, especially for detection of green rusts, to ensure accurate identification of minerals present within the barrier system.

  16. Deployment of an innovative thermally enhanced soil mixing process augmented with zero-valent iron.

    SciTech Connect (OSTI)

    Lynch, P. L.

    1999-01-15T23:59:59.000Z

    An innovative in-situ soil treatment process, referred to as soil mixing/thermally enhanced soil vapor extraction (SM/TESVE), was used to remediate the 317 Area of Argonne National Laboratory-East (i.e., Argonne), which is contaminated with volatile organic compounds (VOCs). Following the initial soil treatment, polishing was required to reduce residual concentrations of contaminants. A study of polishing methods was conducted. It determined that injecting metallic iron particles into the soil, in conjunction with soil mixing, would reduce residual VOC concentrations more effectively than the original conventional soil ventilation approach. After the effectiveness of iron injection was verified, it replaced the soil ventilation step. The modified process involved mixing the soil while hot air and steam were injected into it. Off-gases were captured in a hood over the treatment area. During this process, an iron slurry, consisting of up to 50% iron particles in water with guar gum added as a thickening agent, was injected and mixed into the soil by the mixing equipment. Approximately 6,246 m{sup 3} (8, 170 yd{sup 3}) of soil was treated during this project. Confirmatory samples were then collected. In these samples, VOC concentrations were usually reduced by more than 80%.

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

    SciTech Connect (OSTI)

    Yuxin Wu; Roelof Versteeg; Lee Slater; Doug Labrecque

    2009-05-01T23:59:59.000Z

    Calcium carbonate is a major secondary mineral precipitate that influences PRB reactivity and hydraulic performance. In this study, we conducted column experiments to investigate electrical signatures resulting from concurrent CaCO3 and iron oxides precipitation in two simulated PRB media. Solid phase analysis identified CaCO3 (calcite and aragonite) as a major mineral phase throughout the columns, with magnetite being another major phase present close to the influent. Electrical measurements revealed a consistent decrease in conductivity and polarization magnitude of both columns, suggesting that the electrically insulating CaCO3 dominates the electrical response despite the presence of both electrically conductive iron oxides and CaCO3 precipitates. SEM/EDX imaging suggests that the electrical properties result from the geometrical arrangement of the mineral phases. The CaCO3 forms an insulating film on ZVI/magnetite surfaces, which we assume restricts redox-driven transfer of electric charge 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, electrical measurements may provide a minimally invasive technology for monitoring reactivity loss.

  18. 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.

    2005-12-22T23:59:59.000Z

    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.

  19. 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

    2014-11-12T23:59:59.000Z

    heavy metals/metalloids, reactive oxyanions, and impurities from water/wastewater. The distinctive feature of this novel chemical treatment platform is the controlled formation of magnetite as the main iron corrosion product in the presence of aqueous Fe...

  20. Fundamental Studies of The Removal of Contaminants from Ground and Waste Waters Via Reduction By Zero-Valent metals

    SciTech Connect (OSTI)

    Jory A. Yarmoff; Christopher Amrhein

    2002-04-23T23:59:59.000Z

    Oxyanions of uranium, selenium, chromium, arsenic, technetium, and chlorine (as perchlorate) are frequently found as contaminants on many DOE sites, and in other areas of the U.S.. A potential remediation method is to react the contaminated water with zero-valent iron (ZVI). We are performing fundamental investigations of the interactions of the relevant compounds with Fe filings and single- and poly-crystalline surfaces. The aim of this work is to develop the physical and chemical understanding that is necessary for the development of cleanup techniques and procedures.

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

    E-Print Network [OSTI]

    Kulkarni, Dhananjay Vijay

    2006-08-16T23:59:59.000Z

    .............................................. 22 3 Analysis of green rust for content of Fe(II) and Fe(III) after extraction by 0.12 N HCl or Endox ................................................................................................................ 25 4... immersed in seawater and on the hulls of large ships (3). Green rusts are compounds with double-layers of mixed Fe(II)-Fe(III) hydroxides surrounding a layer of anions (A -n ). This structure can be represented by the general formula (Fe II ) 6-x (Fe...

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

    E-Print Network [OSTI]

    Lee, Chun Woo

    2009-05-15T23:59:59.000Z

    effective technologies, especially chemical treatments, to completely destroy trace levels of perchlorate present in drinking and groundwater. The research on perchlorate reduction by zero-valent titanium (Ti(0)) showed that perchlorate was effectively...

  3. Fundamental Studies of the Removal of Contaminants from Ground and Waste Waters via Reduction by Zero-Valent Metals

    SciTech Connect (OSTI)

    Yarmoff, Jory A.; Amrhein, Christopher

    1999-06-01T23:59:59.000Z

    Contaminated groundwater and surface waters are a problem throughout the United States and the world. In many instances, the types of contamination can be directly attributed to man's actions. For instance, the burial of chemical wastes, casual disposal of solvents in unlined pits, and the development of irrigated agriculture have all contributed to groundwater and surface water contamination. The kinds of contaminants include chlorinated solvents and toxic trace elements (including radioisotopes) that are soluble and mobile in soils and aquifers. Oxyanions of uranium, selenium, chromium, arsenic, technetium, and chlorine (as perchlorate) are frequently found as contaminants on many DOE sites. Uranium is a particularly widespread contaminant at most DOE sites including Oak Ridge, Rocky Flats, Hanford, Idaho (INEEL), and Fernald. The uranium contamination is associated with mining and milling of uranium ore (UMTRA sites), isotope separation and enrichment, and mixed waste and TRU waste burial. In addition, the careless disposal of halogenated solvents, such as carbon tetrachloride and trichloroethylene, has further contaminated many groundwaters at these sites. A potential remediation method for many of these oxyanions and chlorinated-solvents is to react the contaminated water with zero-valent iron. In this reaction, the iron serves as both an electron source and as a catalyst. Elemental iron is already being used on an experimental basis at many DOE sites. Both in situ reactive barriers and above-ground reactors are being developed for this purpose. However, the design and operation of these treatment systems requires a detailed process-level understanding of the interactions between the contaminants and the iron surfaces. We are performing fundamental investigations of the interactions of the relevant chlorinated solvents and trace element-containing compounds with single- and poly-crystalline Fe surfaces. The aim of this work is to develop th e fundamental physical and chemical understanding that is necessary for the development of cleanup techniques and procedures.

  4. THE EFFECT OF SMECTITE ON THE CORROSION OF IRON METAL. | EMSL

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

    THE EFFECT OF SMECTITE ON THE CORROSION OF IRON METAL. THE EFFECT OF SMECTITE ON THE CORROSION OF IRON METAL. Abstract: The combination of zero-valent iron and a clay-type...

  5. 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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directed offOCHCO2:Introduction toManagementOPAM5Parabolic Trough ParabolicPerformance Audit of

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

    E-Print Network [OSTI]

    Wu, Yuxin

    2009-01-01T23:59:59.000Z

    permeable reactive barrier (PRB) integrity using electricalpermeable reactive barrier (PRB) is an in-situ technologyextracted from an active PRB (Wu et al. , 2006), show that

  7. 2.2 Zero-valent Iron Nanoparticles 2.2.1 Background

    E-Print Network [OSTI]

    on the use of ZVI as a PRB. The non-nanoparticle ZVI PRB technology has been used to remediate contaminated

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

    E-Print Network [OSTI]

    Marchal, Fabienne

    2002-01-01T23:59:59.000Z

    H for the reductive dechlorination of 0. 246 mM PCE in 0. 007g/g GRso4 suspension. Error bars for k represent 95% confidence intervals . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Initial reductive capacity of GRso4 for PCE as a function of pH. Error... bars for the reductive capacities represent 95% confidence intervals. . . . . . . . . 21 Reductive dechlorination of 0. 246 mM PCE by non-treated ZVI at pH 8, 9, and 10. Some errors bars are smaller than the symbols...

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

    E-Print Network [OSTI]

    Wu, Yuxin

    2009-01-01T23:59:59.000Z

    concentrations, i.e. calcium and carbonate controllingSolutions Containing Calcium Carbonate with Trichloroetheneand transformation of calcium carbonate polymorphs under

  10. Degradation of Polymers Coating Nano-scale Zero Valent Iron Particles used in Groundwater Remediation

    E-Print Network [OSTI]

    Barthelat, Francois

    if a black precipitate formed indicating sulfide production. Polymer Quantification: An Ultra to transform the solution containing the bacteria into pellet form. Some bacteria and protein is lost during

  11. Aminoclay-templated nanoscale zero-valent iron (nZVI) synthesis for efficient harvesting of

    E-Print Network [OSTI]

    Mosegaard, Klaus

    of oleaginous microalga, Chlorella sp. KR-1 Young-Chul Lee,ae Kyubock Lee,b Yuhoon Hwang,c Henrik Rasmus of oleaginous microalgae was demonstrated. According to various aminoclay loadings (0, 0.25, 0.5, 1.0, 2.5, 5 loading under a magnetic field. In a scaled- up (24 L) microalga harvesting process using magnetic rods

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

    Office of Environmental Management (EM)

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33Frequently AskedEnergyIssuesEnergy SolarRadioactive LiquidSavings forinitial InReactive

  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 DataDepartment of Energy Your Density Isn't Your Destiny:Revised Finding of No53197E T ADRAFT ENVIRONMENTAL

  14. 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

    . The currently pursued modes of hydrogen generation include autothermal and/ or steam reforming of fossil fuels metal-steam reforming (MSR, 3M+4H2OM3O4+4H2). From the standpoint of favorable thermodynamics friendly method of generating high purity hydrogen is by the reaction of certain metals with steam, called

  15. Iron optimization for Fenton-driven oxidation of MTBE-spent granular activated carbon

    SciTech Connect (OSTI)

    Scott G. Huling; Patrick K. Jones; Tony R. Lee [U.S. Environmental Protection Agency, Ada, OK (United States). Office of Research and Development, National Risk Management Research Laboratory

    2007-06-01T23:59:59.000Z

    Fenton-driven chemical oxidation of methyl tert-butyl ether (MTBE)-spent granular activated carbon (GAC) was accomplished through the addition of iron (Fe) and hydrogen peroxide (H{sub 2}O{sub 2}) (15.9 g/L; pH 3). The GAC used was URV, a bituminous-coal based carbon. The Fe concentration in GAC was incrementally varied (1020-25 660 mg/kg) by the addition of increasing concentrations of Fe solution (FeSO4{center_dot}7H{sub 2}O). MTBE degradation in Fe-amended GAC increased by an order of magnitude over Fe-unamended GAC and H{sub 2}O{sub 2} reaction was predominantly (99%) attributed to GAC-bound Fe within the porous structure of the GAC. Imaging and microanalysis of GAC particles indicated limited penetration of Fe into GAC. The optimal Fe concentration was 6710 mg/kg (1020 mg/kg background; 5690 mg/kg amended Fe) and resulted in the greatest MTBE removal and maximum Fe loading oxidation efficiency (MTBE oxidized (g)/Fe loaded to GAC(mg/Kg)). At lower Fe concentrations, the H{sub 2}O{sub 2} reaction was Fe limited. At higher Fe concentrations, the H{sub 2}O{sub 2} reaction was not entirely Fe limited, and reductions in GAC surface area, GAC pore volume, MTBE adsorption, and Fe loading oxidation efficiency were measured. Results are consistent with nonuniform distribution of Fe, pore blockage in H{sub 2}O{sub 2} transport, unavailable Fe, and limitations in H{sub 2}O{sub 2} diffusive transport, and emphasize the importance of optimal Fe loading. 22 refs., 6 figs., 2 tabs.

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

    E-Print Network [OSTI]

    Firdous, Rubina

    2013-12-31T23:59:59.000Z

    in column experiments: Connelly Iron (GI)(~3% C) and Electrolytic Iron (EI) (¡Ü 0.01% C). Kinetic data suggested a shift in rate constant (k) and sorption parameters for both iron types with time. This work demonstrated the implication of carbon during...

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

    E-Print Network [OSTI]

    Yang, Zhen

    2012-12-20T23:59:59.000Z

    .-W., Chiu, P.-C (1998). "Nitrate reduction by metallic iron." Water Res. 32: 8. 22. Huang, Y. H., Zhang, T.C (2005). "Effects of dissolved oxygen on formation of corrosion products and concomitant oxygen and nitrate reduction in zero-valent iron systems... Chromatographer ICP-MS Inductively Coupled Plasma Mass Spectroscopy mM Millimole Na Sodium Na2CO3 Sodium Carbonate NaHCO3 Sodium Bicarbonate NH4+ Ammonium Ion NO3- Nitrate Ion NaCl Sodium chloride NaNO3...

  18. Sequestration of technetium | EMSL

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

    strategy involving the sequestration of technetium as sulfide by sulfide-transformed nano zero-valent iron. The Impact The findings suggest nano zero-valent iron can be used to...

  19. Optimization of soil mixing technology through metallic iron addition.

    SciTech Connect (OSTI)

    Moos, L. P.

    1999-01-15T23:59:59.000Z

    Enhanced soil mixing is a process used to remove volatile organic compounds (VOCs) from soil. In this process, also known as soil mixing with thermally enhanced soil vapor extraction, or SM/TESVE, a soil mixing apparatus breaks up and mixes a column of soil up to 9 m (30 ft) deep; simultaneously, hot air is blown through the soil. The hot air carries the VOCs to the surface where they are collected and safely disposed of. This technology is cost effective at high VOC concentrations, but it becomes cost prohibitive at low concentrations. Argonne National Laboratory-East conducted a project to evaluate ways of improving the effectiveness of this system. The project investigated the feasibility of integrating the SM/TESVE process with three soil treatment processes--soil vapor extraction, augmented indigenous biodegradation, and zero-valent iron addition. Each of these technologies was considered a polishing treatment designed to remove the contaminants left behind by enhanced soil mixing. The experiment was designed to determine if the overall VOC removal effectiveness and cost-effectiveness of the SM/TESVE process could be improved by integrating this approach with one of the polishing treatment systems.

  20. Coarsening in granular systems

    E-Print Network [OSTI]

    Andrea Baldassarri; Andrea Puglisi; Alessandro Sarracino

    2015-04-28T23:59:59.000Z

    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.

  1. Multiscale modeling in granular flow

    E-Print Network [OSTI]

    Rycroft, Christopher Harley

    2007-01-01T23:59:59.000Z

    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 ...

  2. Models of granular ratchets

    E-Print Network [OSTI]

    G. Costantini; A. Puglisi; U. Marini Bettolo Marconi

    2009-05-26T23:59:59.000Z

    We study a general model of granular Brownian ratchet consisting of an asymmetric object moving on a line and surrounded by a two-dimensional granular gas, which in turn is coupled to an external random driving force. We discuss the two resulting Boltzmann equations describing the gas and the object in the dilute limit and obtain a closed system for the first few moments of the system velocity distributions. Predictions for the net ratchet drift, the variance of its velocity fluctuations and the transition rates in the Markovian limit, are compared to numerical simulations and a fair agreement is observed.

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

    E-Print Network [OSTI]

    Lee, Chun Woo

    2009-05-15T23:59:59.000Z

    reduced to chloride using electrochemically developed pitting corrosion on Ti(0). Perchlorate reduction was believed to be caused by an active reductant (dissolved Ti(II)) during the pitting corrosion of Ti(0). The rate of perchlorate reduction...

  4. 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...

  5. 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...

  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. Capillary Fracturing in Granular Media

    E-Print Network [OSTI]

    Holtzman, Ran

    We study the displacement of immiscible fluids in deformable, noncohesive granular media. Experimentally, we inject air into a thin bed of water-saturated glass beads and observe the invasion morphology. The control ...

  8. Lyapunov spectrum of granular gases

    SciTech Connect (OSTI)

    McNamara, Sean; Mareschal, Michel

    2001-06-01T23:59:59.000Z

    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. Introduction Granular Flow at the Critical State

    E-Print Network [OSTI]

    Kuhn, Matthew R.

    : granular topology at the critical state 2D materials only Micro-scale statistics of topology: coordination Scope and Objectives Focus: granular topology at the critical state 2D materials only MicroIntroduction Topology Geometry Granular Flow at the Critical State as a Topologically Disordered

  10. HYPERELASTIC MODELS FOR GRANULAR MATERIALS

    SciTech Connect (OSTI)

    Humrickhouse, Paul W; Corradini, Michael L

    2009-01-29T23:59:59.000Z

    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. Microscopic origin of granular ratcheting

    E-Print Network [OSTI]

    S. McNamara; R. García-Rojo; H. J. Herrmann

    2007-08-10T23:59:59.000Z

    Numerical simulations of assemblies of grains under cyclic loading exhibit ``granular ratcheting'': a small net deformation occurs with each cycle, leading to a linear accumulation of deformation with cycle number. We show that this is due to a curious property of the most frequently used models of the particle-particle interaction: namely, that the potential energy stored in contacts is path-dependent. There exist closed paths that change the stored energy, even if the particles remain in contact and do not slide. An alternative method for calculating the tangential force removes granular ratcheting.

  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.

    2005-12-14T23:59:59.000Z

    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. Advanced hydraulic fracturing methods to create in situ reactive barriers

    SciTech Connect (OSTI)

    Murdoch, L. [FRX Inc., Cincinnati, OH (United States)]|[Clemson Univ., SC (United States). Dept. of Geological Sciences; Siegrist, B.; Meiggs, T. [Oak Ridge National Lab., TN (United States)] [and others

    1997-12-31T23:59:59.000Z

    This article describes the use of hydraulic fracturing to increase permeability in geologic formations where in-situ remedial action of contaminant plumes will be performed. Several in-situ treatment strategies are discussed including the use of hydraulic fracturing to create in situ redox zones for treatment of organics and inorganics. Hydraulic fracturing methods offer a mechanism for the in-situ treatment of gently dipping layers of reactive compounds. Specialized methods using real-time monitoring and a high-energy jet during fracturing allow the form of the fracture to be influenced, such as creation of assymmetric fractures beneath potential sources (i.e. tanks, pits, buildings) that should not be penetrated by boring. Some examples of field applications of this technique such as creating fractures filled with zero-valent iron to reductively dechlorinate halogenated hydrocarbons, and the use of granular activated carbon to adsorb compounds are discussed.

  14. Shock wave propagation in vibrofluidized granular materials

    E-Print Network [OSTI]

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

    2005-11-29T23:59:59.000Z

    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.

  15. Rheology of confined granular flows Patrick RICHARD

    E-Print Network [OSTI]

    Boyer, Edmond

    in the momentum balance if the second term on the right in this equation dominates over the first. This equation://www.aip..org/pacs/index.html> INTRODUCTION Surface flows of granular materials are frequently observed in industrial processes and in nature configurations. The first one is a rotating drum [3, 5, 4, 6], a cylinder, partly filled with granular material

  16. A RESISTIVE FORCE MODEL FOR LEGGED LOCOMOTION ON GRANULAR MEDIA*

    E-Print Network [OSTI]

    Goodisman, Michael

    on granular surfaces like sand and gravel. Understanding the mechanics of legged locomotion on granular media and kinematics, e.g., a bio-inspired robot L-leg rotated through uniform granular media (loosely packed ~ 1 mm including insects, lizards, and mammals encounter granular surfaces like sand and gravel in their natural

  17. Nonlinear Sound during Granular Impact

    E-Print Network [OSTI]

    Abram H. Clark; Alec J. Petersen; Lou Kondic; R. P. Behringer

    2014-08-08T23:59:59.000Z

    How do dynamic stresses propagate in granular material after a high-speed impact? This occurs often in natural and industrial processes. Stress propagation in a granular material is controlled by the inter-particle force law, $f$, in terms of particle deformation, $\\delta$, often given by $f\\propto\\delta^{\\alpha}$, with $\\alpha>1$. This means that a linear wave description is invalid when dynamic stresses are large compared to the original confining pressure. With high-speed video and photoelastic grains with varying stiffness, we experimentally study how forces propagate following an impact and explain the results in terms of the nonlinear force law (we measure $\\alpha\\approx 1.4$). The spatial structure of the forces and the propagation speed, $v_f$, depend on a dimensionless parameter, $M'=t_cv_0/d$, where $v_0$ is the intruder speed at impact, $d$ is the grain diameter, and $t_c$ is a binary collision time between grains with relative speed $v_0$. For $M'\\ll 1$, propagati ng forces are chain-like, and the measured $v_f \\propto d/t_c\\propto v_b(v_0/v_b)^\\frac{\\alpha-1}{\\alpha+1}$, where $v_b$ is the bulk sound speed. For larger $M'$, the force response has a 2D character, and forces propagate faster than predicted by $d/t_c$ due to collective stiffening of a packing.

  18. Lack of iron | EMSL

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

    Lack of iron Lack of iron Released: February 26, 2014 Iron-bearing minerals in sediments naturally reduce contaminant levels The Science The release of wastes associated with...

  19. Drag Law of Two Dimensional Granular Fluids

    E-Print Network [OSTI]

    Satoshi Takada; Hisao Hayakawa

    2015-04-19T23:59:59.000Z

    Drag force law acting on a moving circular disk in a two-dimensional granular medium is analyzed based on the discrete element method (DEM). It is remarkable that the drag force on the moving disk in moderate dense and pure two-dimensional granular medium can be well reproduced by a perfect fluid with separation from the boundary. A yield force, being independent of the moving speed of the disk, appears if a dry friction between the granular disks and the bottom plate exists. The perfect fluidity is violated in this case. The yield force and the drag force diverge at the jamming point.

  20. Chaoticity of the Wet Granular Gas

    E-Print Network [OSTI]

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

    2007-05-22T23:59:59.000Z

    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.

  1. Granular gases under extreme driving

    E-Print Network [OSTI]

    W. Kang; J. Machta; E. Ben-Naim

    2010-08-06T23:59:59.000Z

    We study inelastic gases in two dimensions using event-driven molecular dynamics simulations. Our focus is the nature of the stationary state attained by rare injection of large amounts of energy to balance the dissipation due to collisions. We find that under such extreme driving, with the injection rate much smaller than the collision rate, the velocity distribution has a power-law high energy tail. The numerically measured exponent characterizing this tail is in excellent agreement with predictions of kinetic theory over a wide range of system parameters. We conclude that driving by rare but powerful energy injection leads to a well-mixed gas and constitutes an alternative mechanism for agitating granular matter. In this distinct nonequilibrium steady-state, energy cascades from large to small scales. Our simulations also show that when the injection rate is comparable with the collision rate, the velocity distribution has a stretched exponential tail.

  2. Shallow granular flows O. Bokhove1

    E-Print Network [OSTI]

    Al Hanbali, Ahmad

    , in the granular case, is that the constitutive or closure laws for the bottom stress relations are generally sense using space and/or time averages. When gravitational forcing is small, the collective particle

  3. A constitutive law for dense granular flows

    E-Print Network [OSTI]

    Pierre Jop; Yoël Forterre; Olivier Pouliquen

    2006-12-05T23:59:59.000Z

    A continuum description of granular flows would be of considerable help in predicting natural geophysical hazards or in designing industrial processes. However, the constitutive equations for dry granular flows, which govern how the material moves under shear, are still a matter of debate. One difficulty is that grains can behave like a solid (in a sand pile), a liquid (when poured from a silo) or a gas (when strongly agitated). For the two extreme regimes, constitutive equations have been proposed based on kinetic theory for collisional rapid flows, and soil mechanics for slow plastic flows. However, the intermediate dense regime, where the granular material flows like a liquid, still lacks a unified view and has motivated many studies over the past decade. The main characteristics of granular liquids are: a yield criterion (a critical shear stress below which flow is not possible) and a complex dependence on shear rate when flowing. In this sense, granular matter shares similarities with classical visco-plastic fluids such as Bingham fluids. Here we propose a new constitutive relation for dense granular flows, inspired by this analogy and recent numerical and experimental work. We then test our three-dimensional (3D) model through experiments on granular flows on a pile between rough sidewalls, in which a complex 3D flow pattern develops. We show that, without any fitting parameter, the model gives quantitative predictions for the flow shape and velocity profiles. Our results support the idea that a simple visco-plastic approach can quantitatively capture granular flow properties, and could serve as a basic tool for modelling more complex flows in geophysical or industrial applications.

  4. Contact micromechanics in granular media with clay

    SciTech Connect (OSTI)

    Ita, S.L.

    1994-08-01T23:59:59.000Z

    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.

  5. Stochastic and deterministic models for dense granular flow

    E-Print Network [OSTI]

    Kamrin, Kenneth Norman

    2008-01-01T23:59:59.000Z

    Granular materials such as sand or gravel surround us everyday and yet remain poorly understood. In this thesis, two models are developed for dense granular flow, each capable of predicting flows with accuracy in multiple ...

  6. A taxonomy of granular partitions Thomas Bittner and Barry Smith

    E-Print Network [OSTI]

    Forbus, Kenneth D.

    A taxonomy of granular partitions Thomas Bittner and Barry Smith Qualitative Reasoning Group. In Smith and Brogaard (2000) the notion of granular partition was introduced as a generalization of David

  7. Achieving progressive fine granularity scalable coding in H.26L

    E-Print Network [OSTI]

    Shanmugampillai, Muthukumar

    2001-01-01T23:59:59.000Z

    Fine granularity scalable (FGS) coding and progressive fine granularity scalable (PFGS) coding are novel scalable video schemes which are ideally suited for streaming multimedia over networks with varying bandwidth, network conditions and receiver...

  8. Friction and dilatancy in immersed granular matter

    E-Print Network [OSTI]

    Thibaut Divoux; Jean-Christophe Géminard

    2008-06-10T23:59:59.000Z

    The friction of a sliding plate on a thin immersed granular layer obeys Amonton-Coulomb law. We bring to the fore a large set of experimental results which indicate that, over a few decades of values, the effective dynamical friction-coefficient depends neither on the viscosity of the interstitial fluid nor on the size of beads in the sheared layer, which bears out the analogy with the solid-solid friction in a wide range of experimental parameters. We accurately determine the granular-layer dilatancy, which dependance on the grain size and slider velocity can be qualitatively accounted by considering the rheological behaviour of the whole slurry. However, additional results, obtained after modification of the grain surface by a chemical treatment, demonstrate that the theoretical description of the flow properties of granular matter, even immersed, requires the detailed properties of the grain surface to be taken into account.

  9. Comparison of Hyperelastic Models for Granular Materials

    SciTech Connect (OSTI)

    Paul W. Humrickhouse; J. Phil Sharpe; Michael L. Corradini

    2010-01-01T23:59:59.000Z

    Three recently proposed hyperelastic models for granular materials are compared with experiment data. Though all three are formulated to give elastic moduli that are power law functions of the mean stress, they have rather different dependencies on individual stresses, and generally differ from well established experimental forms. Predicted static stress distributions are in qualitative agreement with experiments, but do not differ greatly from isotropic linear elasticity, and similarly fail to account for variability in experiment data that presumably occurs due to a preparation dependence of granular materials.

  10. Melting a granular glass by cooling

    E-Print Network [OSTI]

    Jan Plagge; Claus Heussinger

    2013-02-05T23:59:59.000Z

    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.

  11. Fourier's Law for a Granular Fluid

    E-Print Network [OSTI]

    James W. Dufty

    2007-07-07T23:59:59.000Z

    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.

  12. Iron and Prochlorococcus/

    E-Print Network [OSTI]

    Thompson, Anne Williford

    2009-01-01T23:59:59.000Z

    Iron availability and primary productivity in the oceans are intricately linked through photosynthesis. At the global scale we understand how iron addition induces phytoplankton blooms through meso-scale iron-addition ...

  13. Investigating Iron Ions | EMSL

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

    Investigating Iron Ions Investigating Iron Ions Computer code provides detailed predictions of highly charged ions in water Using resources at EMSL, scientists obtained...

  14. Scaling of convective velocity in a vertically vibrated granular bed

    E-Print Network [OSTI]

    Tomoya M. Yamada; Hiroaki Katsuragi

    2014-05-30T23:59:59.000Z

    We experimentally study the velocity scaling of granular convection which is a possible mechanism of the regolith migration on the surface of small asteroids. In order to evaluate the contribution of granular convection to the regolith migration, the velocity of granular convection under the microgravity condition has to be revealed. Although it is hard to control the gravitational acceleration in laboratory experiments, scaling relations involving the gravitational effect can be evaluated by systematic experiments. Therefore, we perform such a systematic experiment of the vibration-induced granular convection. From the experimental data, a scaling form for the granular convective velocity is obtained. The obtained scaling form implies that the granular convective velocity can be decomposed into two characteristic velocity components: vibrational and gravitational velocities. In addition, the system size dependence is also scaled. According to the scaling form, the granular convective velocity $v$ depends on the gravitational acceleration $g$ as $v \\propto g^{0.97}$ when the normalized vibrational acceleration is fixed.

  15. Trajectory entanglement in dense granular materials

    E-Print Network [OSTI]

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

    2012-02-23T23:59:59.000Z

    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.

  16. Design and analysis of jammable granular systems

    E-Print Network [OSTI]

    Cheng, Nadia G. (Nadia Gen San)

    2013-01-01T23:59:59.000Z

    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 ...

  17. A stochastic flow rule for granular materials

    E-Print Network [OSTI]

    Ken Kamrin; Martin Z. Bazant

    2006-09-19T23:59:59.000Z

    There have been many attempts to derive continuum models for dense granular flow, but a general theory is still lacking. Here, we start with Mohr-Coulomb plasticity for quasi-2D granular materials to calculate (average) stresses and slip planes, but we propose a "stochastic flow rule" (SFR) to replace the principle of coaxiality in classical plasticity. The SFR takes into account two crucial features of granular materials - discreteness and randomness - via diffusing "spots" of local fluidization, which act as carriers of plasticity. We postulate that spots perform random walks biased along slip-lines with a drift direction determined by the stress imbalance upon a local switch from static to dynamic friction. In the continuum limit (based on a Fokker-Planck equation for the spot concentration), this simple model is able to predict a variety of granular flow profiles in flat-bottom silos, annular Couette cells, flowing heaps, and plate-dragging experiments -- with essentially no fitting parameters -- although it is only expected to function where material is at incipient failure and slip-lines are inadmissible. For special cases of admissible slip-lines, such as plate dragging under a heavy load or flow down an inclined plane, we postulate a transition to rate-dependent Bagnold rheology, where flow occurs by sliding shear planes. With different yield criteria, the SFR provides a general framework for multiscale modeling of plasticity in amorphous materials, cycling between continuum limit-state stress calculations, meso-scale spot random walks, and microscopic particle relaxation.

  18. Erosion dynamics of a wet granular medium

    E-Print Network [OSTI]

    Gautier Lefebvre; Pierre Jop

    2014-12-08T23:59:59.000Z

    Liquid may give strong cohesion properties to a granular medium, and confer a solid-like behavior. We study the erosion of a fixed circular aggregate of wet granular matter subjected to a flow of dry grains inside a half-filled rotating drum. During the rotation, the dry grains flow around the fixed obstacle. We show that its diameter decreases linearly with time for low liquid content, as wet grains are pulled-out of the aggregate. This erosion phenomenon is governed by the properties of the liquids. The erosion rate decreases exponentially with the surface tension while it depends on the viscosity to the power -1. We propose a model based on the force fluctuations arising inside the flow, explaining both dependencies: the capillary force acts as a threshold and the viscosity controls the erosion time scale. We also provide experiments using different flowing grains confirming our model.

  19. Brownian motor in a granular medium

    E-Print Network [OSTI]

    Riccardo Balzan; Fergal Dalton; Vittorio Loreto; Alberto Petri; Giorgio Pontuale

    2009-09-21T23:59:59.000Z

    In this work we experimentally study the behavior of a freely-rotating asymmetric probe immersed in a vibrated granular medium. For a wide variety of vibration conditions the probe exhibits a steady rotation whose direction is constant with respect to the asymmetry. By changing the vibration amplitude and by filtering the noise in different frequency bands we show that the velocity of rotation does not depend only on the RMS acceleration $\\Gamma$, but also on the amount of energy provided to two separate frequency bands which are revealed to be important for the dynamics of the granular medium: the first band governs the transfer of energy from the grains to the probe, and the second affects the dynamics by altering the viscosity of the vibro-fluidized material.

  20. Granular Brownian motion with dry friction

    E-Print Network [OSTI]

    A. Gnoli; A. Puglisi; H. Touchette

    2013-04-12T23:59:59.000Z

    The interplay between Coulomb friction and random excitations is studied experimentally by means of a rotating probe in contact with a stationary granular gas. The granular material is independently fluidized by a vertical shaker, acting as a 'heat bath' for the Brownian-like motion of the probe. Two ball bearings supporting the probe exert nonlinear Coulomb friction upon it. The experimental velocity distribution of the probe, autocorrelation function, and power spectra are compared with the predictions of a linear Boltzmann equation with friction, which is known to simplify in two opposite limits: at high collision frequency, it is mapped to a Fokker-Planck equation with nonlinear friction, whereas at low collision frequency, it is described by a sequence of independent random kicks followed by friction-induced relaxations. Comparison between theory and experiment in these two limits shows good agreement. Deviations are observed at very small velocities, where the real bearings are not well modeled by Coulomb friction.

  1. Refraction of shear zones in granular materials

    E-Print Network [OSTI]

    Tamas Unger

    2007-01-08T23:59:59.000Z

    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.

  2. Technical Assistance to Ohio Closure Sites Technologies to Address Excavated VOC Contaminated Soil

    E-Print Network [OSTI]

    Hazen, Terry

    and available solar heat. This report focuses on design features and recommendations for implementing disposal, passive soil venting, enhanced soil venting, zero-valent iron, anaerobic bioremediation, aerobic and functional design requirements (equipment, flow rates, options, issues, cautions, etc.).The design

  3. Dispersion enhanced metal/zeolite catalysts

    DOE Patents [OSTI]

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

    1987-03-31T23:59:59.000Z

    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.

  4. IIT Bombay offers to license intellectual property (IP) created through its research and development efforts and which are available in the form of patents, patent applications, design, trademark, copy-

    E-Print Network [OSTI]

    Narayanan, H.

    An improved process for water treatment to remove Arsenic, Iron and Phosphate 2336/MUM/2008 by zero valent EE 14 Refrigeration cum water heating system 151/MUM/2002 EE 15 Switchable heat pipe 152/MUM/2002 EE as a fluorescence sensor for the recognition 730/MUM/2011 of polycyclic aromatic hydrocarbons (PAHs

  5. Bioremediation of Uranium Plumes with Nano-scale

    E-Print Network [OSTI]

    Fay, Noah

    (IV) (UO2[s], uraninite) Anthropogenic · Release of mill tailings during uranium mining - MobilizationBioremediation of Uranium Plumes with Nano-scale Zero-valent Iron Angela Athey Advisers: Dr. Reyes Undergraduate Student Fellowship Program April 15, 2011 #12;Main Sources of Uranium Natural · Leaching from

  6. Formation of aerobic granular sludge biofilms for sustainable wastewater treatment

    E-Print Network [OSTI]

    ENAC/ Formation of aerobic granular sludge biofilms for sustainable wastewater treatment David G Research, Microbiology of Interfaces, Magdeburg (Germany) EDCE 2011 / From activated sludge flocs

  7. Nonlinear elasto-plastic model for dense granular flow

    E-Print Network [OSTI]

    Ken Kamrin

    2009-05-07T23:59:59.000Z

    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.

  8. Mutiscale Modeling of Segregation in Granular Flows

    SciTech Connect (OSTI)

    Jin Sun

    2007-08-03T23:59:59.000Z

    Modeling and simulation of segregation phenomena in granular flows are investigated. Computational models at different scales ranging from particle level (microscale) to continuum level (macroscale) are employed in order to determine the important microscale physics relevant to macroscale modeling. The capability of a multi-fluid model to capture segregation caused by density difference is demonstrated by simulating grain-chaff biomass flows in a laboratory-scale air column and in a combine harvester. The multi-fluid model treats gas and solid phases as interpenetrating continua in an Eulerian frame. This model is further improved by incorporating particle rotation using kinetic theory for rapid granular flow of slightly frictional spheres. A simplified model is implemented without changing the current kinetic theory framework by introducing an effective coefficient of restitution to account for additional energy dissipation due to frictional collisions. The accuracy of predicting segregation rate in a gas-fluidized bed is improved by the implementation. This result indicates that particle rotation is important microscopic physics to be incorporated into the hydrodynamic model. Segregation of a large particle in a dense granular bed of small particles under vertical. vibration is studied using molecular dynamics simulations. Wall friction is identified as a necessary condition for the segregation. Large-scale force networks bearing larger-than-average forces are found with the presence of wall friction. The role of force networks in assisting rising of the large particle is analyzed. Single-point force distribution and two-point spatial force correlation are computed. The results show the heterogeneity of forces and a short-range correlation. The short correlation length implies that even dense granular flows may admit local constitutive relations. A modified minimum spanning tree (MST) algorithm is developed to asymptotically recover the force statistics in the force networks. This algorithm provides a possible route to constructing a continuum model with microstructural information supplied from it. Microstructures in gas fluidized beds are also analyzed using a hybrid method, which couples the discrete element method (DEM) for particle dynamics with the averaged two-fluid (TF) equations for the gas phase. Multi-particle contacts are found in defluidized regions away from bubbles in fluidized beds. The multi-particle contacts invalidate the binary-collision assumption made in the kinetic theory of granular flows for the defluidized regions. Large ratios of contact forces to drag forces are found in the same regions, which confirms the relative importance of contact forces in determining particle dynamics in the defluidized regions.

  9. Granular slumping on a horizontal surface E. Lajeunesse

    E-Print Network [OSTI]

    Lajeunesse, Eric

    and a semicircular tube, allowing us to compare two-dimensional and axisymmetric flows, with particular focusGranular slumping on a horizontal surface E. Lajeunesse Laboratoire de Dynamique des Systèmes of an experimental investigation of the flow induced by the collapse of a column of granular material glass beads

  10. High-Frequency Resistivity of Soft Magnetic Granular Films

    E-Print Network [OSTI]

    permeability was measured and used to predict the power loss expected when granular films are used as high-frequency core materials for film inductors. The power loss is predicted to be lower than that of commercial Ni permeability, power loss, soft magnetic film. I. INTRODUCTION SOFT magnetic granular films are considered ideal

  11. A MODEL FOR GRANULAR STATICS WITH IMPENETRABILITY CONSTRAINTS

    E-Print Network [OSTI]

    Panchenko, Alexander

    of frictionless granular packings. The packing is deformed by imposing boundary conditions, modeling those in shear and compression experiments. In our two-dimensional model, the packing is represented by a spring of granular materials. Examples of such ma- terials are common, including sand, gravel, medicinal pills, coins

  12. A Simple Model on Granular Friction Hisao Hayakawa

    E-Print Network [OSTI]

    Hayakawa, Hisao

    observed even in atomic dry friction and and melt fractures in polymers [9,10]. Recently, Nasuno et al [11 for simulation of granular particles [13]. In particular, we 2 #12; regard Coulomb's friction law duringA Simple Model on Granular Friction Hisao Hayakawa Graduate School of Human and Environmental

  13. Invited review: Effect of temperature on a granular pile

    E-Print Network [OSTI]

    Thibaut Divoux

    2010-11-30T23:59:59.000Z

    As a fragile construction, a granular pile is very sensitive to minute external perturbations. In particular, it is now well established that a granular assembly is sensitive to variations of temperature. Such variations can produce localized rearrangements as well as global static avalanches inside a pile. In this review, we sum up the various observations that have been made concerning the effect of temperature on a granular assembly. In particular, we dwell on the way controlled variations of temperature have been employed to generate the compaction of a granular pile. After laying emphasis on the key features of this compaction process, we compare it to the classic vibration-induced compaction. Finally, we also review other granular systems in a large sense, from microscopic (jammed multilamellar vesicles) to macroscopic scales (stone heave phenomenon linked to freezing and thawing of soils) for which periodic variations of temperature could play a key role in the dynamics at stake.

  14. 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

    2005-10-23T23:59:59.000Z

    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.

  15. Size separation in vibrated granular matter

    E-Print Network [OSTI]

    A. Kudrolli

    2004-02-06T23:59:59.000Z

    We review recent developments in size separation in vibrated granular materials. Motivated by a need in industry to efficiently handle granular materials and a desire to make fundamental advances in non-equilibrium physics, experimental and theoretical investigations have shown size separation to be a complex phenomena. Large particles in a vibrated granular system invariably rise to the top. However, they may also sink to the bottom, or show other patterns depending on subtle variations in physical conditions. While size ratio is a dominant factor, particle specific properties such as density, inelasticity and friction can play an important role. The nature of the energy input, boundary conditions and interstitial air have been also shown to be significant factors in determining spatial distributions. The presence of convection can enhance mixing or lead to size separation. Experimental techniques including direct visualization and magnetic resonance imaging are being used to investigate these properties. Molecular dynamics and Monte Carlo simulation techniques have been developed to probe size separation. Analytical methods such as kinetic theory are being used to study the interplay between particle size and density in the vibro-fluidized regime, and geometric models have been proposed to describe size separation for deep beds. Besides discussing these studies, we will also review the impact of inelastic collision and friction on the density and velocity distributions to gain a deeper appreciation of the non-equilibrium nature of the system. While a substantial number of studies have been accomplished, considerable work is still required to achieve a firm description of the phenomena.

  16. DEM simulation of experimental dense granular packing

    SciTech Connect (OSTI)

    Hanifpour, Maryam; Allaei, Mehdi Vaez [Department of Physics, University of Tehran, Tehran (Iran, Islamic Republic of); Francois, Nicolas; Saadatfar, Mohammad [Department of Applied Mathematics, Research School of Physics and Engineering, Australian National University, Canberra (Australia)

    2013-06-18T23:59:59.000Z

    In this study we present numerical analysis performed on the experimental results of sphere packings of mono-sized hard sphere whose packing fraction spans across a wide range of 0.59<{Phi}<0.72. Using X-ray Computed Tomography (XCT), we have full access to the 3D structure of the granular packings. Numerical analysis performed on thr data provides the first experimental proofs of how densification affects local order parameters. Furthermore by combining Discrete Element Method (DEM) and the experimental results from XCT, we investigate how the intergranular forces change with the onset of crystallization.

  17. Pressure-shear experiments on granular materials.

    SciTech Connect (OSTI)

    Reinhart, William Dodd (Sandia National Laboratories, Albuquerque, NM); Thornhill, Tom Finley, III (, Sandia National Laboratories, Albuquerque, NM); Vogler, Tracy John; Alexander, C. Scott (Sandia National Laboratories, Albuquerque, NM)

    2011-10-01T23:59:59.000Z

    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.

  18. Imaging of granular sources in high energy heavy ion collisions

    E-Print Network [OSTI]

    Zhi-Tao Yang; Wei-Ning Zhang; Lei Huo; Jing-Bo Zhang

    2008-11-13T23:59:59.000Z

    We investigate the source imaging for a granular pion-emitting source model in high energy heavy ion collisions. The two-pion source functions of the granular sources exhibit a two-tiered structure. Using a parametrized formula of granular two-pion source function, we examine the two-tiered structure of the source functions for the imaging data of Au+Au collisions at Alternating Gradient Synchrotron (AGS) and Relativistic Heavy Ion Collider (RHIC). We find that the imaging technique introduced by Brown and Danielewicz is suitable for probing the granular structure of the sources. Our data-fitting results indicate that there is not visible granularity for the sources at AGS energies. However, the data for the RHIC collisions with the selections of $40 < {\\rm centrality} < 90%$ and $0.20granular emission than that of one Gaussian. The model with granular source has more parameters than the simple Gaussian, hence can describe more complicated shapes.

  19. Ageing of a granular pile induced by thermal cycling

    E-Print Network [OSTI]

    Thibaut Divoux; Ion Vassilief; Hervé Gayvallet; Jean-Christophe Géminard

    2009-06-02T23:59:59.000Z

    Here we show that variations of temperature, even of a few degrees in amplitude, induce the ageing of a granular pile. In particular, we report measurements of physical properties of a granular heap submitted to thermal cycles. Namely, we focus on the evolution of the thermal linear-expansion coefficient and of the thermal conductivity of the pile with the number of cycles. The present contribution nicely supplements a recent article we published elsewhere [Phys. Rev. Lett. \\textbf{101}, 148303 (2008)] and introduces a different and promising method to impose temperature cycles to a granular pile.

  20. Granular Solid Hydrodynamics (GSH): a broad-ranged macroscopic theory of granular media

    E-Print Network [OSTI]

    Yimin Jiang; Mario Liu

    2014-07-27T23:59:59.000Z

    A unified continuum-mechanical theory has been until now lacking for granular media, some believe it could not exist. Derived employing the hydrodynamic approach, GSH is such a theory, though as yet a qualitative one. The behavior being accounted for includes static stress distribution, elastic wave, elasto-plastic motion, the critical state and rapid dense flow. The equations and application to a few typical experiments are presented here.

  1. Dynamics of Gas-Fluidized Granular Rods

    E-Print Network [OSTI]

    L. J. Daniels; Y. Park; T. C. Lubensky; D. J. Durian

    2008-11-17T23:59:59.000Z

    We study a quasi-two-dimensional monolayer of granular rods fluidized by a spatially and temporally homogeneous upflow of air. By tracking the position and orientation of the particles, we characterize the dynamics of the system with sufficient resolution to observe ballistic motion at the shortest time scales. Particle anisotropy gives rise to dynamical anisotropy and superdiffusive dynamics parallel to the rod's long axis, causing the parallel and perpendicular mean squared displacements to become diffusive on different timescales. The distributions of free times and free paths between collisions deviate from exponential behavior, underscoring the non-thermal character of the particle motion. The dynamics show evidence of rotational-translational coupling similar to that of an anisotropic Brownian particle. We model rotational-translation coupling in the single-particle dynamics with a modified Langevin model using non-thermal noise sources. This suggests a phenomenological approach to thinking about collections of self-propelling particles in terms of enhanced memory effects.

  2. Frictional granular mechanics: A variational approach

    SciTech Connect (OSTI)

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

    2009-10-16T23:59:59.000Z

    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.

  3. Software digitizer for high granular gaseous detector

    E-Print Network [OSTI]

    Haddad, Y; Boudry, V

    2015-01-01T23:59:59.000Z

    A sampling calorimeter using gaseous sensor layers with digital readout [1] is near perfect for ``Particle Flow Algorithm'' [2,3] approach, since it is homogeneous over large surfaces, robust, cost efficient, easily segmentable to any readout pad dimension and size and almost insensitive to neutrons. Monte-Carlo (MC) programs such as GEANT4 [4] simulate with high precision the energy deposited by particles. The sensor and electronic response associated to a pad are calculated in a separate ``digitization'' process. We develop a general method for simulating the pad response using the spatial information from a simulation done at high granularity. The digitization method proposed here has been applied to gaseous detectors including Glass Resistive Plate Chambers (GRPC) and MicroMegas, and validated on test beam data. Experimental observable such as pad multiplicity and mean number of hits at different thresholds have been reproduced with high precision.

  4. A Theory of Granular Partitions Thomas Bittner and Barry Smith

    E-Print Network [OSTI]

    Bittner, Thomas

    CHAPTER 7 A Theory of Granular Partitions Thomas Bittner and Barry Smith Institute for Formal of part and whole relations (Smith, 1998) as a framework for ontological theorizing. Mereology is better

  5. Resilient modulus and permanent deformation testing of unbound granular materials

    E-Print Network [OSTI]

    Kancherla, Anuroopa

    2005-11-01T23:59:59.000Z

    Numerous research efforts have been devoted to characterizing the behavior of granular materials, which is one of the main concerns of pavement engineers. For better understanding of this behavior, laboratory tests where in-situ stress conditions...

  6. Inert plug formation in the DDT of granular energetic materials

    SciTech Connect (OSTI)

    Son, S.F.; Asay, B.W.; Bdzil, J.B.

    1995-09-01T23:59:59.000Z

    A mechanism is proposed to explain the {open_quotes}plugs{close_quotes} that have been observed in deflagration-to-detonation transition (DDT) of granular explosives. Numerical simulations are performed that demonstrate the proposed mechanism. Observed trends are reproduced.

  7. Maximum angle of stability of a wet granular pile

    E-Print Network [OSTI]

    Loss, Daniel

    ­7 . The friction-based Mohr­Coulomb model3,8 distinguishes between granular friction and interparticle friction stability of dry particles on the surface of a pile2 is in excellent agreement with experiment. However

  8. SHEAR DEFORMATION IN GRANULAR MATERIAL S. G. Bardenhagen

    E-Print Network [OSTI]

    Sulsky, Deborah L.

    of New Mexico Albuquerque, NM 87131 An investigation into the properties of granular materials of the binder as a lubricant in force chains. INTRODUCTION We report the results of an investigation

  9. Moving Granular Bed Filter Development Program

    SciTech Connect (OSTI)

    Wilson, K.B.; Haas, J.C. [Combustion Power Co., San Mateo, CA (United States); Gupta, R.P.; Turk, B.S. [Research Triangle Inst., Research Triangle Park, NC (United States)

    1996-12-31T23:59:59.000Z

    For coal-fired power plants utilizing a gas turbine, the removal of ash particles is necessary to protect the turbine and to meet emission standards. Advantages are also evident for a filter system that can remove other coal-derived contaminants such as alkali, halogens, and ammonia. With most particulates and other contaminants removed, erosion and corrosion of turbine materials, as well as deposition of particles within the turbine, are reduced to acceptable levels. The granular bed filter is suitable for this task in a pressurized gasification or combustion environment. The objective of the base contract was to develop conceptual designs of moving granular bed filter (GBF) and ceramic candle filter technologies for control of particles from integrated gasification combined cycle (IGCC), pressurized fluidized-bed combustion (PFBC), and direct coal-fueled turbine (DCFT) systems. The results of this study showed that the GBF design compared favorably with the candle filter. Three program options followed the base contract. The objective of Option I, Component Testing, was to identify and resolve technical issues regarding GBF development for IGCC and PFBC environments. This program was recently completed. The objective of Option II, Filter Proof Tests, is to test and evaluate the moving GBF system at a government-furnished hot-gas cleanup test facility. This facility is located at Southern Company Services (SCS), Inc., Wilsonville, Alabama. The objective of Option III, Multicontaminant Control Using a GBF, is to develop a chemically reactive filter material that will remove particulates plus one or more of the following coal-derived contaminants: alkali, halogens, and ammonia.

  10. A lattice gas model of avalanches in a granular pile

    E-Print Network [OSTI]

    Antal Karolyi; Janos Kertesz

    1997-10-31T23:59:59.000Z

    A granular media lattice gas (GMLG) model is used to study avalanches in a two-dimensional granular pile. We demonstrate the efficiency of the algorithm by showing that several features of the non-critical behaviour of real sandpile surfaces, such as the bounded outflow statistics or the finite-size effect of the time evolution of the pile mass, can be reproduced by this simulation approach.

  11. Particle Scale Dynamics in Granular Impact Abram H. Clark,1

    E-Print Network [OSTI]

    Kondic, Lou

    experiments, v ( C, where C ' 300 m=s is the granular sound speed, measured from photoelastic space-time plots are cut from PS-1 material (Vishay Precision Group; bulk density of 1:28 g=cm3, elastic modulus of 2.5 GPa of granular impact, where intruders strike 2D beds of photoelastic disks from above. High-speed video captures

  12. Grow Iron, Slow Pollution | EMSL

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

    Grow Iron, Slow Pollution Grow Iron, Slow Pollution Scientists connect previous studies on electron transport in hematite Making a Deposit: Scanning electron micrographs of...

  13. Continuous shearing of dense and wet granular materials in a torsional rheometer

    E-Print Network [OSTI]

    Kannan, Raguraman

    2002-01-01T23:59:59.000Z

    . The experimental research mainly focuses on the rapid deformation of granular material in a confined area. Experiments were carried out on a torsional rheometer to study how the addition of different types of lubricating oils affect the characteristics of granular...

  14. Quasi-static mechanics of granular materials

    E-Print Network [OSTI]

    P. Evesque

    2005-07-13T23:59:59.000Z

    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. Standleg Moving Granular Bed Filter development program

    SciTech Connect (OSTI)

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

    1992-11-01T23:59:59.000Z

    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.

  16. Standleg Moving Granular Bed Filter development program

    SciTech Connect (OSTI)

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

    1992-01-01T23:59:59.000Z

    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.

  17. Software digitizer for high granular gaseous detector

    E-Print Network [OSTI]

    Y. Haddad; M. Ruan; V. Boudry

    2014-05-06T23:59:59.000Z

    A sampling calorimeter equipped with gaseous sensor layers with digital readout is near perfect for "Particle Flow Algorithm" approach, since it is homogeneous over large surfaces, robust, cost efficient, easily segmentable to any readout pad dimension and size and almost insensitive to neutrons. The response of a finely segmented digital calorimeter is characterized by track efficiency and multiplicity. Monte Carlo (MC) programs such as GEANT4 simulate with high precision the energy deposited by particles. The sensor and electronic response associated to a pad are calculated in a separate "digitization" process. We developed a general method for simulating the pad response, a digitization, reproducing efficiency and multiplicity, using the spatial information from a simulation done at higher granularity. The digitization method proposed here has been applied to gaseous detectors including Glass Resistive Plate Chambers (GRPC) and MicroMegas. Validating the method on test beam data, experimental observables such as efficiency, multiplicity and mean number of hits at different thresholds have been reproduced with high precision.

  18. Softening of Granular Packings with Dynamic Forcing

    E-Print Network [OSTI]

    C. J. Olson Reichhardt; L. M. Lopatina; X. Jia; P. A. Johnson

    2014-06-17T23:59:59.000Z

    We perform numerical simulations of a two-dimensional bidisperse granular packing subjected to both a static confining pressure and a sinusoidal dynamic forcing applied by a wall on one edge of the packing. We measure the response experienced by a wall on the opposite edge of the packing and obtain the resonant frequency of the packing as the static or dynamic pressures are varied. Under increasing static pressure, the resonant frequency increases, indicating a velocity increase of elastic waves propagating through the packing. In contrast, when the dynamic amplitude is increased for fixed static pressure, the resonant frequency decreases, indicating a decrease in the wave velocity. This occurs both for compressional and for shear dynamic forcing, and is in agreement with experimental results. We find that the average contact number $Z_c$ at the resonant frequency decreases with increasing dynamic amplitude, indicating that the elastic softening of the packing is associated with a reduced number of grain-grain contacts through which the elastic waves can travel. We image the excitations created in the packing and show that there are localized disturbances or soft spots that become more prevalent with increasing dynamic amplitude. Our results are in agreement with experiments on glass bead packings and earth materials such as sandstone and granite, and may be relevant to the decrease in elastic wave velocities that has been observed to occur near fault zones after strong earthquakes, in surficial sediments during strong ground motion, and in structures during earthquake excitation.

  19. Deflagration to detonation experiments in granular HMX

    SciTech Connect (OSTI)

    Burnside, N.J.; Son, S.F.; Asay, B.W.; Dickson, P.M.

    1998-03-01T23:59:59.000Z

    In this paper the authors report on continuing work involving a series of deflagration-to-detonation transition (DDT) experiments in which they study the piston-initiated DDT of heavily confined granular cyclotetramethylenetetranitramine (HMX). These experiments were designed to he useful in model development and evaluation. A main focus of these experiments is the effect of density on the DDT event. Particle size distribution and morphology are carefully characterized. In this paper they present recent surface area analysis. Earlier studies demonstrated extensive fracturing and agglomeration in samples at densities as low as 75% TMD as evidenced by dramatic decreases in particle size distribution due to mild stimulus. This is qualitatively confirmed with SEM images and quantitatively studied with gas absorption surface area analysis. Also, in this paper they present initial results using a microwave interferometer technique. Dynamic calibration of the technique was performed, a 35 GHz signal is used to increase resolution, and the system has been designed to be inexpensive for repeated experiments. The distance to where deformation of the inner wall begins for various densities is reported. This result is compared with the microwave interferometer measurements.

  20. Evolution of shear zones in granular materials

    E-Print Network [OSTI]

    Balazs Szabo; Janos Torok; Ellak Somfai; Sandra Wegner; Ralf Stannarius; Axel Bose; Georg Rose; Frank Angenstein; Tamas Borzsonyi

    2014-08-07T23:59:59.000Z

    The evolution of wide shear zones (or shear bands) was investigated experimentally and numerically for quasistatic dry granular flows in split bottom shear cells. We compare the behavior of materials consisting of beads, irregular grains (e.g. sand) and elongated particles. Shearing an initially random sample, the zone width was found to significantly decrease in the first stage of the process. The characteristic shear strain associated with this decrease is about unity and it is systematically increasing with shape anisotropy, i.e. when the grain shape changes from spherical to irregular (e.g. sand) and becomes elongated (pegs). The strongly decreasing tendency of the zone width is followed by a slight increase which is more pronounced for rod like particles than for grains with smaller shape anisotropy (beads or irregular particles). The evolution of the zone width is connected to shear induced density change and for nonspherical particles it also involves grain reorientation effects. The final zone width is significantly smaller for irregular grains than for spherical beads.

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

    E-Print Network [OSTI]

    Huang, Bei

    2011-08-31T23:59:59.000Z

    OF THE TEFLON BAG ................................................................ 28 FIGURE 2.2: SCHEMATIC OF THE COLUMN EXPERIMENTAL ASSEMBLY. ............................ 29 FIGURE 2.3: PHOTO OF COLUMN EXPERIMENT WITH PERISTALTIC PUMP AND GLASS COLUMN... FIGURE 3.1 PHOTO OF COLUMN EXPERIMENT WITH PERISTALTIC PUMP AND GLASS COLUMN. ................................................................................................................................... 53 FIGURE 3.2: BREAKTHROUGH OF TCE FROM FOUR...

  2. Granular physics in low-gravity environments using DEM

    E-Print Network [OSTI]

    G. Tancredi; A. Maciel; L. Heredia; P. Richeri; S. Nesmachnow

    2011-11-26T23:59:59.000Z

    Granular materials of different sizes are present on the surface of several atmosphere-less Solar System bodies. The phenomena related to granular materials have been studied in the framework of the discipline called Granular Physics; that has been studied experimentally in the laboratory and, in the last decades, by performing numerical simulations. The Discrete Element Method simulates the mechanical behavior of a media formed by a set of particles which interact through their contact points. The difficulty in reproducing vacuum and low-gravity environments makes numerical simulations the most promising technique in the study of granular media under these conditions. In this work, relevant processes in minor bodies of the Solar System are studied using the Discrete Element Method. Results of simulations of size segregation in low-gravity environments in the cases of the asteroids Eros and Itokawa are presented. The segregation of particles with different densities was analysed, in particular, the case of comet P/Hartley 2. The surface shaking in these different gravity environments could produce the ejection of particles from the surface at very low relative velocities. The shaking causing the above processes is due to: impacts, explosions like the release of energy by the liberation of internal stresses or the re accommodation of material. Simulations of the passage of impact-induced seismic waves through a granular medium were also performed. We present several applications of the Discrete Element Methods for the study of the physical evolution of agglomerates of rocks under low-gravity environments.

  3. Location and chemical composition of microbially induced phosphorus precipitates in anaerobic and aerobic granular sludge

    E-Print Network [OSTI]

    Boyer, Edmond

    and aerobic granular sludge A. Mañasa,b,c,e , M. Spérandioa,b,c , F. Deckerd and B. Biscanse aINSA, UPS, INP X-ray analysis (SEM-EDX) applied to granular sludge used for biological treatment of high sludge blanket (UASB) reactors and two aerobic granular sequenced batch reactors (GSBR) were evaluated

  4. Evolution of the contact network during tilting cycles of a granular pile under gravity

    E-Print Network [OSTI]

    Staron, Lydie

    Evolution of the contact network during tilting cycles of a granular pile under gravity S. Deboeuf of a granular pile undergoing quasi-static tilting cycles in the gravity field. The volumic deformation of granular piles during continuous load in the gravity field (Staron, Vilotte, & Radjai 2002). Far before

  5. Dense granular flows: two-particle argument accounts for friction-like constitutive law with threshold

    E-Print Network [OSTI]

    Boyer, Edmond

    Dense granular flows: two-particle argument accounts for friction-like constitutive law that exhibits a flow threshold expressed as a finite effective friction at flow onset. The value 83.10.Gr 83.60.La I. INTRODUCTION Dense flows of dry granular materials and granular pastes is still

  6. Collapse of a granular column under rotation J.M. Warnett a,

    E-Print Network [OSTI]

    Thomas, Peter J.

    and geotechni- cal retaining walls. Failure of these containers is analogous to a `dam break' investigated of experiments on the collapse of a granular column [7­11] and the failure of a granular step [5 the theoretical models with the dam break itself. An agricultural application where granular flows are utilised

  7. 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

    2014-11-19T23:59:59.000Z

    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.

  8. Inhomogeneous Cooling of the Rough Granular Gas in Two Dimensions

    E-Print Network [OSTI]

    Sudhir N. Pathak; Dibyendu Das; R. Rajesh

    2014-07-03T23:59:59.000Z

    We study the inhomogeneous clustered regime of a freely cooling granular gas of rough particles in two dimensions using large-scale event driven simulations and scaling arguments. During collisions, rough particles dissipate energy in both the normal and tangential directions of collision. In the inhomogeneous regime, translational kinetic energy and the rotational energy decay with time $t$ as power-laws $t^{-\\theta_T}$ and $t^{-\\theta_R}$. We numerically determine $\\theta_T \\approx 1$ and $\\theta_R \\approx 1.6$, independent of the coefficients of restitution. The inhomogeneous regime of the granular gas has been argued to be describable by the ballistic aggregation problem, where particles coalesce on contact. Using scaling arguments, we predict $\\theta_T=1$ and $\\theta_R=1$ for ballistic aggregation, $\\theta_R$ being different from that obtained for the rough granular gas. Simulations of ballistic aggregation with rotational degrees of freedom are consistent with these exponents.

  9. Hard Sphere Dynamics for Normal and Granular Fluids

    E-Print Network [OSTI]

    James W. Dufty; Aparna Baskaran

    2005-03-08T23:59:59.000Z

    A fluid of N smooth, hard spheres is considered as a model for normal (elastic collisions) and granular (inelastic collisions) fluids. The potential energy is discontinuous for hard spheres so the pairwise forces are singular and the usual forms of Newtonian and Hamiltonian mechanics do not apply. Nevertheless, particle trajectories in the N particle phase space are well defined and the generators for these trajectories can be identified. The first part of this presentation is a review of the generators for the dynamics of observables and probability densities. The new results presented in the second part refer to applications of these generators to the Liouville dynamics for granular fluids. A set of eigenvalues and eigenfunctions of the generator for this Liouville dynamics is identified in a special "stationary representation". This provides a class of exact solutions to the Liouville equation that are closely related to hydrodynamics for granular fluids.

  10. NMR Experiments on a Three-Dimensional Vibrofluidized Granular Medium

    E-Print Network [OSTI]

    Chao Huan; Xiaoyu Yang; D. Candela; R. W. Mair; R. L. Walsworth

    2003-05-12T23:59:59.000Z

    A three-dimensional granular system fluidized by vertical container vibrations was studied using pulsed field gradient (PFG) NMR coupled with one-dimensional magnetic resonance imaging (MRI). The system consisted of mustard seeds vibrated vertically at 50 Hz, and the number of layers N_ell <= 4 was sufficiently low to achieve a nearly time-independent granular fluid. Using NMR, the vertical profiles of density and granular temperature were directly measured, along with the distributions of vertical and horizontal grain velocities. The velocity distributions showed modest deviations from Maxwell-Boltzmann statistics, except for the vertical velocity distribution near the sample bottom which was highly skewed and non-Gaussian. Data taken for three values of N_ell and two dimensionless accelerations Gamma=15,18 were fit to a hydrodynamic theory, which successfully models the density and temperature profiles including a temperature inversion near the free upper surface.

  11. Kinetic Theory for Binary Granular Mixtures at Low-Density

    E-Print Network [OSTI]

    Vicente Garzo

    2007-04-10T23:59:59.000Z

    Many features of granular media can be modelled as a fluid of hard spheres with {\\em inelastic} collisions. Under rapid flow conditions, the macroscopic behavior of grains can be described through hydrodynamic equations. At low-density, a fundamental basis for the derivation of the hydrodynamic equations and explicit expressions for the transport coefficients appearing in them is provided by the Boltzmann kinetic theory conveniently modified to account for inelastic binary collisions. The goal of this chapter is to give an overview of the recent advances made for binary granular gases by using kinetic theory tools. Some of the results presented here cover aspects such as transport properties, energy nonequipartition, instabilities, segregation or mixing, non-Newtonian behavior, .... In addition, comparison of the analytical results with those obtained from Monte Carlo and molecular dynamics simulations is also carried out, showing the reliability of kinetic theory to describe granular flows even for strong dissipation.

  12. Creep motion of a granular pile induced by thermal cycling

    E-Print Network [OSTI]

    Thibaut Divoux; Hervé Gayvallet; Jean-Christophe Géminard

    2008-09-18T23:59:59.000Z

    We report a time-resolved study of the dynamics associated with the slow compaction of a granular column submitted to thermal cycles. The column height displays a complex behavior: for a large amplitude of the temperature cycles, the granular column settles continuously, experiencing a small settling at each cycle; By contrast, for small-enough amplitude, the column exhibits a discontinuous and intermittent activity: successive collapses are separated by quiescent periods whose duration is exponentially distributed. We then discuss potential mechanisms which would account for both the compaction and the transition at finite amplitude.

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

    E-Print Network [OSTI]

    Takahiro Hatano

    2007-05-08T23:59:59.000Z

    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.

  14. Time-resolved dynamics of granular matter by random laser emission

    E-Print Network [OSTI]

    Folli, Viola; Puglisi, Andrea; Leuzzi, Luca; Conti, Claudio

    2013-01-01T23:59:59.000Z

    Because of the huge commercial importance of granular systems, the second-most used material in industry after water, intersecting the industry in multiple trades, like pharmacy and agriculture, fundamental research on grain-like materials has received an increasing amount of attention in the last decades. In photonics, the applications of granular materials have been only marginally investigated. We report the first phase-diagram of a granular as obtained by laser emission. The dynamics of vertically-oscillated granular in a liquid solution in a three-dimensional container is investigated by employing its random laser emission. The granular motion is function of the frequency and amplitude of the mechanical solicitation, we show how the laser emission allows to distinguish two phases in the granular and analyze its spectral distribution. This constitutes a fundamental step in the field of granulars and gives a clear evidence of the possible control on light-matter interaction achievable in grain-like system.

  15. Time-resolved dynamics of granular matter by random laser emission

    E-Print Network [OSTI]

    Viola Folli; Neda Ghofraniha; Andrea Puglisi; Luca Leuzzi; Claudio Conti

    2013-10-22T23:59:59.000Z

    Because of the huge commercial importance of granular systems, the second-most used material in industry after water, intersecting the industry in multiple trades, like pharmacy and agriculture, fundamental research on grain-like materials has received an increasing amount of attention in the last decades. In photonics, the applications of granular materials have been only marginally investigated. We report the first phase-diagram of a granular as obtained by laser emission. The dynamics of vertically-oscillated granular in a liquid solution in a three-dimensional container is investigated by employing its random laser emission. The granular motion is function of the frequency and amplitude of the mechanical solicitation, we show how the laser emission allows to distinguish two phases in the granular and analyze its spectral distribution. This constitutes a fundamental step in the field of granulars and gives a clear evidence of the possible control on light-matter interaction achievable in grain-like system.

  16. Creating an iron understudy | EMSL

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

    iron reactivity. To test their process, the team created tiny iron oxide spheres with titanium added to control the Fe(II)Fe(III) ratio directly. The designer particles are also...

  17. Sound wave propagation in weakly polydisperse granular materials

    E-Print Network [OSTI]

    Luding, Stefan

    Sound wave propagation in weakly polydisperse granular materials O. Mouraille, S. Luding NSM/DCT/TUDelft, Julianalaan 136, 2628 BL Delft, Netherlands Abstract Dynamic simulations of wave propagation are performed. A small perturbation is created on one side of a static packing and its propagation, for both P- and S-waves

  18. 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

    2015-04-14T23:59:59.000Z

    To clarify the grain-scale mechanisms that control the onset and cessation of sediment transport, we performed molecular dynamics simulations of granular beds driven by a model hydrodynamic shear flow. We find a critical value for the Shields number (the nondimensional shear stress at the top of the granular bed) that separates flowing and static states, with a bed flow rate that is discontinuous at the critical value. The transition times between flowing and static states diverge as the system approaches the critical Shields number from above and below. Additionally we find that, for finite systems, the onset of flow occurs stochastically at supercritical Shields numbers. We show that the statistics of the Shields number at failure obey Weibullian weakest-link statistics, and that the onset of flow is caused by local grain rearrangements that give rise to additional rearrangements and then to continuous flow. Thus, the onset of motion is governed by the packing structure of the granular bed, even deep beneath the surface. Since the fluid dynamics is strongly coupled to the settling process and thus to the bed structure, this also suggests a strong feedback between the fluid dynamics and granular physics in bed mobilization.

  19. Design guidelines for granular particles in a conical centrifugal filter

    E-Print Network [OSTI]

    Fleck, Norman A.

    Design guidelines for granular particles in a conical centrifugal filter A.F.M. Bizarda , D centrifugal filter is thereby obtained as a function of the slurry and basket properties. Corresponding basket) 1. Introduction 1.1. Centrifugal filters Centrifugal filters are commonly used in the food

  20. Bond anisotropy and cohesion of wet granular materials

    E-Print Network [OSTI]

    Boyer, Edmond

    -R, Domaine Universitaire, B.P. 53, 38041 Grenoble, Cedex 9, France. We analyze the Coulomb cohesion of wet. The contact dynamics simulations of a wet material, in which a capillary force law is prescribed, shear strength, Coulomb cohesion, jamming, fragile behavior 1. Introduction Wet granular materials

  1. Inert plug formation in the DDT of granular energetic materials

    SciTech Connect (OSTI)

    Son, S.F.; Asay, B.W.; Bdzil, J.B. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States of America)

    1996-05-01T23:59:59.000Z

    A mechanism is proposed to explain the {open_quotes}plugs{close_quotes} that have been observed in deflagration-to-detonation transition (DDT) of granular explosives. Numerical simulations are performed that demonstrate the proposed mechanism. Observed trends are reproduced. {copyright} {ital 1996 American Institute of Physics.}

  2. The micromacro mechanics of granular materials Stefan Luding

    E-Print Network [OSTI]

    Luding, Stefan

    contact. The tangential force involves dissipation due to Coulomb friction, but also some tangential at the contacts, so that rotations of the particles are important due to friction. Several examples are presented behavior under large deformations. For dry, non­cohesive granular media, the discrete element method

  3. Numerical issues in plasticity models for granular flows

    E-Print Network [OSTI]

    are essentially a multidimensional counterpart to the standard Coulomb's law of dry friction. Unfortunately engineering. Coulomb (1776) was the first to relate the angle of slip to the friction prop- erties 27695-8205, USA Abstract Friction plays a fundamental role in the Mechanics of granular materials. Two

  4. Two-dimensional granular slumps down slopes Andrew J. Hogg

    E-Print Network [OSTI]

    Hogg, Andrew

    is modelled as a Coulomb drag with a constant coefficient of friction. The flows leave a thin layer with laboratory observations of the slumping of four dry granular materials. It is shown the coefficient of friction only varies slightly for each of the materials used. Mathematical modelling

  5. Transition Dynamics of Frictional Granular Clusters Antoinette Tordesillas

    E-Print Network [OSTI]

    Froyland, Gary

    Zhang Department of Physics, Shanghai Jiao Tong University, Shanghai 200240, P. R. China Robert P inelastic re- arrangements, especially as they relate to the stability of and energy released from force great promise in the control of granular be- haviour in many practical settings (e.g. forecasting

  6. Foams and granular media known state of mat-

    E-Print Network [OSTI]

    Cox, Simon

    Foams and granular media 2 known state of mat- design glasses with de- perties on an industrial n disordered ail in this review, mod- proaches to the glass ledge of advanced liq- renormalization group, FIG a broad range of lengthscales, such as atomic (top left), colloidal (top right) systems, but also in foams

  7. Performance of a zerovalent iron reactive barrier for the treatment of arsenic in groundwater: Part 2. Geochemical modeling and solid phase studies

    SciTech Connect (OSTI)

    Beak, Douglas G.; Wilkin, Richard T.; (EPA)

    2009-06-12T23:59:59.000Z

    Arsenic uptake processes were evaluated in a zerovalent iron reactive barrier installed at a lead smelting facility using geochemical modeling, solid-phase analysis, and X-ray absorption spectroscopy techniques. Aqueous speciation of arsenic is expected to play a key role in directing arsenic uptake processes. Geochemical modeling reveals contrasting pH-dependencies for As(III) and As(V) precipitation. At the moderately alkaline pH conditions typically encountered in zerovalent iron reactive barriers, As(III) is unlikely to precipitate as an oxide or a sulfide phase. Conversely, increasing pH is expected to drive precipitation of metal arsenates including ferrous arsenate. Bacterially mediated sulfate reduction plays an important role in field installations of granular iron. Neoformed iron sulfides provide surfaces for adsorption of oxyanion and thioarsenic species of As(III) and As(V) and are expected to provide enhanced arsenic removal capacity. X-ray absorption near edge structure (XANES) spectra indicate that arsenic is sequestered in the solid phase as both As(III) and As(V) in coordination environments with O and S. Arsenic removal in the PRB probably results from several pathways, including adsorption to iron oxide and iron sulfide surfaces, and possible precipitation of ferrous arsenate. Corrosion of granular iron appears to result in some As(III) oxidation to As(V) as the proportion of As(V) to As(III) in the solid phase is greater compared to influent groundwater. As(0) was not detected in the PRB materials. These results are broadly comparable to laboratory based studies of arsenic removal by zerovalent iron, but additional complexity is revealed in the field environment, which is largely due to the influence of subsurface microbiota.

  8. Iron pages of HTSC

    SciTech Connect (OSTI)

    Gasparov, V. A., E-mail: vgasparo@issp.ac.r [Russian Academy of Sciences, Institute of Solid State Physics (Russian Federation)

    2010-08-15T23:59:59.000Z

    Experimental data are presented on the superconducting and electronic properties of iron-based high-temperature superconductors in the normal and superconducting states. The following topics are discussed: lattice structure; structure of magnetic vortices; magnetic penetration depth; Fermi surface; isotope effect; and critical magnetic fields both in oxide compounds of 1111 type and oxide-free compounds of 122, 111, and 011 types as a function of the doping level, temperature, and external pressure.

  9. Temperature scaling in a dense vibro-fluidised granular material

    E-Print Network [OSTI]

    P. Sunthar; V. Kumaran

    1999-04-16T23:59:59.000Z

    The leading order "temperature" of a dense two dimensional granular material fluidised by external vibrations is determined. An asymptotic solution is obtained where the particles are considered to be elastic in the leading approximation. The velocity distribution is a Maxwell-Boltzmann distribution in the leading approximation. The density profile is determined by solving the momentum balance equation in the vertical direction, where the relation between the pressure and density is provided by the virial equation of state. The predictions of the present analysis show good agreement with simulation results at higher densities where theories for a dilute vibrated granular material, with the pressure-density relation provided by the ideal gas law, are in error. The theory also predicts the scaling relations of the total dissipation in the bed reported by McNamara and Luding (PRE v 58, p 813).

  10. Mixing and segregation rates in sheared granular materials

    E-Print Network [OSTI]

    Laura A. Golick; Karen E. Daniels

    2009-06-17T23:59:59.000Z

    The size-segregation of granular materials, a process colloquially known as the Brazil Nut Effect, has generally been thought to proceed faster the greater the size difference of the particles. We experimentally investigate sheared bidisperse granular materials as a function of the size ratio of the two species, and find that the mixing rate at low confining pressure behaves as expected from percolation-based arguments. However, we also observe an anomalous effect for the re-segregation rates, wherein particles of both dissimilar and similar sizes segregate more slowly than intermediate particle size ratios. Combined with the fact that increasing the confining pressure significantly suppresses both mixing and segregation rates of particles of dissimilar size, we propose that the anomalous behavior may be attributed to a species-dependent distribution of forces within the system.

  11. Friction and the oscillatory motion of granular flows

    E-Print Network [OSTI]

    Lydie Staron

    2012-11-26T23:59:59.000Z

    This contribution reports on numerical simulations of 2D granular flows on erodible beds. The broad aim is to investigate whether simple flows of model granular matter exhibits spontaneous oscillatory motion in generic flow conditions, and in this case, whether the frictional properties of the contacts between grains may affect the existence or the characteristics of this oscillatory motion. The analysis of different series of simulations show that the flow develops an oscillatory motion with a well-defined frequency which increases like the inverse of the velocity's square root. We show that the oscillation is essentially a surface phenomena. The amplitude of the oscillation is higher for lower volume fractions, and can thus be related to the flow velocity and grains friction properties. The study of the influence of the periodic geometry of the simulation cell shows no significant effect. These results are discussed in relation to sonic sands.

  12. Collective rheology in quasi static shear flow of granular media

    E-Print Network [OSTI]

    Tamás Unger

    2010-09-20T23:59:59.000Z

    This paper is devoted to the basic question of what factors determine the strain field in a quasi static granular flow. It is shown that using stress - strain rate relations is not the proper way to understand quasi static rheology. An alternative approach is discussed where the local deformation is regarded as the cause of deformation in the vicinity. We suggest a continuum model where the local shear strain is proportional to its Laplacian and the proportionality factor is determined by the local stress. The predicted behavior is tested in a three dimensional shear cell by means of computer simulations. The simplicity of our setup makes it ideal to demonstrate and examine the fundamental open questions of collective granular flows. The observed shear profile is interpreted in the framework of the suggested model.

  13. Clustering instability in a freely falling granular jet

    E-Print Network [OSTI]

    Matthias E. Möbius

    2006-04-03T23:59:59.000Z

    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.

  14. Ordering of granular rod monolayers driven far from thermodynamic equilibrium

    E-Print Network [OSTI]

    Thomas Müller; Daniel de las Heras; Ingo Rehberg; Kai Huang

    2015-04-23T23:59:59.000Z

    The orientational order of vertically agitated granular rod monolayers is investigated experimentally and compared quantitatively with equilibrium Monte Carlo simulations and density functional theory. At sufficiently high number density, short rods form a tetratic state and long rods form a uniaxial nematic state. The length-to-width ratio at which the order changes from tetratic to uniaxial is around $7.3$ in both experiments and simulations. This fact illustrates the universal aspects of the ordering of rod-shaped particles across thermal and athermal systems. Moreover, the assembly of granular rods into ordered states is found to be independent on the frequency and strength of the agitations, suggesting that the detailed nature of energy injection into such a nonequilibrium system does not play a crucial role.

  15. Fluctuations relation and external thermostats: an application to granular materials

    E-Print Network [OSTI]

    F. Bonetto; G. Gallavotti; A. Giuliani; F. Zamponi

    2006-05-08T23:59:59.000Z

    In this note we discuss a paradigmatic example of interacting particles subject to non conservative external forces and to the action of thermostats consisting of external (finite) reservoirs of particles. We then consider a model of granular materials of interest for experimental tests that had recently attracted lot of attentions. This model can be reduced to the previously discussed example under a number of assumptions, in particular that inelasticity due to internal collisions can be neglected for the purpose of measuring the large deviation functional for entropy production rate. We show that if the restitution coefficient in the granular material model is close to one, then the required assuptions are verified on a specific time scale and we predict a fluctuation relation for the entropy production rate measured on the same time scale.

  16. Cages and anomalous diffusion in vibrated dense granular media

    E-Print Network [OSTI]

    Camille Scalliet; Andrea Gnoli; Andrea Puglisi; Angelo Vulpiani

    2015-04-28T23:59:59.000Z

    A vertically shaken granular medium hosts a blade rotating around a fixed vertical axis, which acts as a mesorheological probe. At high densities, independently from the shaking intensity, the blade's dynamics show strong caging effects, marked by transient sub-diffusion and a maximum in the velocity power density spectrum (vpds), at a resonant frequency $\\sim 10$ Hz. Interpreting the data through a diffusing harmonic cage model allows us to retrieve the elastic constant of the granular medium and its collective diffusion coefficient. For high frequencies $f$, a tail $\\sim 1/f$ in the vpds reveals non-trivial correlations in the intra-cage micro-dynamics. At very long times (larger than $10$ s), a super-diffusive behavior emerges, ballistic in the most extreme cases. Consistently, the distribution of slow velocity inversion times $\\tau$ displays a power-law decay, likely due to persistent collective fluctuations of the host medium.

  17. Modeling compaction-induced energy dissipation of granular HMX

    SciTech Connect (OSTI)

    Gonthier, K.A. [Lamar Univ., Beaumont, TX (US). Dept. of Mechanical Engineering; Menikoff, R.; Son, S.F.; Asay, B.W. [Los Alamos National Lab., NM (US)

    1998-12-31T23:59:59.000Z

    A thermodynamically consistent model is developed for the compaction of granular solids. The model is an extension of the single phase limit of two-phase continuum models used to describe Deflagration-to-Detonation Transition (DDT) experiments. The focus is on the energetics and dissipation of the compaction process. Changes in volume fraction are partitioned into reversible and irreversible components. Unlike conventional DDT models, the model is applicable from the quasi-static to dynamic compaction regimes for elastic, plastic, or brittle materials. When applied to the compaction of granular HMX (a brittle material), the model predicts results commensurate with experiments including stress relaxation, hysteresis, and energy dissipation. The model provides a suitable starting point for the development of thermal energy localization sub-scale models based on compaction-induced dissipation.

  18. Revisiting Johnson and Jackson boundary conditions for granular flows

    SciTech Connect (OSTI)

    Li, Tingwen; Benyahia, Sofiane

    2012-07-01T23:59:59.000Z

    In this article, we revisit Johnson and Jackson boundary conditions for granular flows. The oblique collision between a particle and a flat wall is analyzed by adopting the classic rigid-body theory and a more realistic semianalytical model. Based on the kinetic granular theory, the input parameter for the partial-slip boundary conditions, specularity coefficient, which is not measurable in experiments, is then interpreted as a function of the particle-wall restitution coefficient, the frictional coefficient, and the normalized slip velocity at the wall. An analytical expression for the specularity coefficient is suggested for a flat, frictional surface with a low frictional coefficient. The procedure for determining the specularity coefficient for a more general problem is outlined, and a working approximation is provided.

  19. Development of permeable reactive barriers to prevent radionuclide migration from the nuclear waste repositories

    SciTech Connect (OSTI)

    Zakharova, E. [Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Moscow (Russian Federation); Kalmykov, S.; Batuk, O. [Chemistry department of Lomonosov Moscow, State University, Moscow (Russian Federation); Kazakovskaya, T.; Shapovalov, V. [All-Russian Scientific Research Institute of Experimental Physics (Russian Federation); Haire, M.J. [Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    2007-07-01T23:59:59.000Z

    This paper is focused on three possible materials for permeable reactive barriers (PRB): 1) depleted uranium oxide that is accumulated as a residual product of the natural uranium enrichment process, 2) zero-valent iron and, 3) the composite material based on montmorillonite clay modified with different anion exchangers. The main aim of permeable reactive barriers is to prevent release of radionuclides emerging from a repository waste package containing spent nuclear fuel to outside the control area of the nuclear waste repository sites. The most experimentally developed material is depleted uranium oxide. It can be used both as a component of radiation shielding and as an absorbent for migrating long-lived radionuclides (especially {sup 237}Np and {sup 99}Tc). Experiments demonstrate the high sorption properties of depleted uranium oxide towards Np and Tc both from deionized water and from solution that simulates Yucca Mountain. Zero-valent iron, and the composite based on montmorillonite clay, also seem to be very promising to use in a PRB. Nano-particles of zero-valent iron with high surface will reduce high valency Np and Tc to the tetravalent state and thus immobilize them due to the extremely low solubility of corresponding hydroxides. The composite based on montmorillonite clay modified with different anion exchangers will possess high sorption affinity towards anionic and cationic species. (authors)

  20. Several applications of a model for dense granular flows

    E-Print Network [OSTI]

    Cawthorn, Christopher John

    2011-03-15T23:59:59.000Z

    model for the dense flow of dry granular materials (Jop, Forterre & Pouliquen, 2006, Nature, 441, 167-192). The model, based upon a generalisation of Coulomb sliding friction, is known to perform well when modelling certain simple free surface flows. We... such model was proposed by Savage & Hutter (1989), who accounted for simple Coulomb sliding friction at the base of the flow, and neglected internal stresses. This simple model, and its later generalisation to two-dimensional flows over complex topography...

  1. Criticality and Scaling Relations in a Sheared Granular Material

    E-Print Network [OSTI]

    Takahiro Hatano; Michio Otsuki; Shin-ichi Sasa

    2006-09-09T23:59:59.000Z

    We investigate a rheological property of a dense granular material under shear. By a numerical experiment of the system with constant volume, we find a critical volume fraction at which the shear stress and the pressure behave as power-law functions of the shear strain rate. We also present a simple scaling argument that determines the power-law exponents. Using these results, we interpret a power-law behavior observed in the system under constant pressure.

  2. Critical behaviors of sheared frictionless granular materials near jamming transition

    E-Print Network [OSTI]

    Michio Otsuki; Hisao Hayakawa

    2009-06-25T23:59:59.000Z

    Critical behaviors of sheared dense and frictionless granular materials in the vicinity of the jamming transition are numerically investigated. From the extensive molecular dynamics simulation, we verify the validity of the scaling theory near the jamming transition proposed by Otsuki and Hayakawa (Prog. Theor. Phys., 121, 647 (2009)). We also clarify the critical behaviors of the shear viscosity and the pair correlation function based on both a phenomenology and the simulation.

  3. 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)

    1992-02-28T23:59:59.000Z

    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.

  4. Plug flow and the breakdown of Bagnold scaling in cohesive granular flows

    E-Print Network [OSTI]

    Robert Brewster; Gary S. Grest; James W. Landry; Alex J. Levine

    2005-09-05T23:59:59.000Z

    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 gravitational energy is balanced by dissipation arising from intergrain forces, the velocity profile in the flow direction scales with depth in a manner consistent with the predictions of Bagnold. Here we demonstrate that this Bagnold scaling does not hold for the analogous steady-flows in cohesive granular media. We develop a generalization of the Bagnold constitutive relation to account for our observation and speculate as to the underlying physical mechanisms responsible for the different constitutive laws for cohesive and noncohesive granular media.

  5. 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.

    1991-10-17T23:59:59.000Z

    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.

  6. On the capillary stress tensor in wet granular materials

    E-Print Network [OSTI]

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

    2011-05-05T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    1994-04-01T23:59:59.000Z

    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.

  8. 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

    2010-11-05T23:59:59.000Z

    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.

  9. Microbial reduction of iron ore

    DOE Patents [OSTI]

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

    1989-01-01T23:59:59.000Z

    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.

  10. Microbial reduction of iron ore

    DOE Patents [OSTI]

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

    1989-11-14T23:59:59.000Z

    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.

  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. Iron efficiency in sorghum

    E-Print Network [OSTI]

    Esty, James Craig

    1979-01-01T23:59:59.000Z

    ) James Craig Esty, B, S. , Panhandle State College Co-Chairmen of Advisory Committee: Dr. Arthur B. Onken Dr. Lloyd R. Hossner R tt *ht ' d f * ' g * gh L~Sh bicolor (L. ) Moenchj parental lines and Fl hybrids indicate varying degrees of iron (Fe...) utilization. Visual ratings after seven days of Fe stress indicated only one hybrid, ATx 378 x RTx 2536, to be green or Fe efficient. Hybrids or parental lines rated partially chlorotic were: ATx 378 x RTx 415 and RTx 2536. Those sorghums rated chlorotic...

  13. Validation of hadronic models using CALICE highly granular calorimeters, 15th International Conference on Calorimetry in High Energy Physics

    E-Print Network [OSTI]

    The CALICE Collaboration

    2015-01-01T23:59:59.000Z

    Validation of hadronic models using CALICE highly granular calorimeters, 15th International Conference on Calorimetry in High Energy Physics

  14. Transcriptional and translational regulatory responses to iron...

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

    of Candidatus Pelagibacter ubique cultures to iron limitation in natural seawater media supplemented with a siderophore to chelate iron. MethodologyPrincipal Findings:...

  15. The Influence of Thermal Convection on Density Segregation in a Vibrated Binary Granular System

    E-Print Network [OSTI]

    Al Hanbali, Ahmad

    of this work strongly imply the possibility that, for an adequately fluidised granular bed, the degree^ole of diffusive behaviour in the segregation of a gran- ular bed in the convective regime. The results on the fluctuation of particle velocities about a mean value [53]. For a granular bed excited by, for instance

  16. Friction of a slider on a granular layer: Nonmonotonic thickness dependence and effect of boundary conditions

    E-Print Network [OSTI]

    Kudrolli, Arshad

    Friction of a slider on a granular layer: Nonmonotonic thickness dependence and effect of boundary the effective friction encountered by a mass sliding on a granular layer as a function of bed thickness and boundary roughness conditions. The observed friction has minima for a small number of layers before

  17. Progress of Theoretical Physics Supplement 1 Simulation of granular friction and its effective theory

    E-Print Network [OSTI]

    Hayakawa, Hisao

    sliding of the plate. Similar behaviors have been observed even in atomic dry friction 4) and meltProgress of Theoretical Physics Supplement 1 Simulation of granular friction and its effective­8501 (Received ) This paper discusses the application of the distinct element method (DEM) for granular friction

  18. ensl-00178753,version1-12Oct2007 Friction and dilatancy in immersed granular matter.

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    -measurements in the dry case [8], G´eminard et al. brought to the fore a dynamic friction- coefficient µ in the caseensl-00178753,version1-12Oct2007 Friction and dilatancy in immersed granular matter. T. Divoux'Italie, 69364 Lyon cedex 07, France. The friction of a sliding plate on a thin immersed granular layer obeys

  19. Tsunami generated by a granular collapse down a rough inclined S. Viroulet1

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    epl draft Tsunami generated by a granular collapse down a rough inclined plane S. Viroulet1 , A Jersey 08544, USA PACS 47.57.Gc ­ Granular flow, complex fluids PACS 92.10.hl ­ Tsunamis PACS 45.70.Ht wave and the evolution of its amplitude during the propagation. The experiments show that whereas

  20. Granular impact cratering by liquid drops: Understanding raindrop imprints through an analogy to asteroid strikes

    E-Print Network [OSTI]

    Runchen Zhao; Qianyun Zhang; Hendro Tjugito; Xiang Cheng

    2014-12-23T23:59:59.000Z

    When a granular material is impacted by a sphere, its surface deforms like a liquid yet it preserves a circular crater like a solid. Although the mechanism of granular impact cratering by solid spheres is well explored, our knowledge on granular impact cratering by liquid drops is still very limited. Here, by combining high-speed photography with high-precision laser profilometry, we investigate liquid-drop impact dynamics on granular surface and monitor the morphology of resulting impact craters. Surprisingly, we find that, despite the enormous energy and length difference, granular impact cratering by liquid drops follows the same energy scaling and reproduces the same crater morphology as that of asteroid impact craters. Inspired by this similarity, we integrate the physical insight from planetary sciences, the liquid marble model from fluid mechanics and the concept of jamming transition from granular physics into a simple theoretical framework that quantitatively describes all the main features of liquid-drop imprints in granular media. Our study sheds light on the mechanisms governing raindrop impacts on granular surfaces and reveals a remarkable analogy between familiar phenomena of raining and catastrophic asteroid strikes.

  1. 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-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

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

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    numerical simulations a general criterion for liquefaction that applies also for the cases in which the poreA General Criterion for Liquefaction in Granular Layers with Heterogeneous Pore Pressure December.g.flekkoy@fys.uio.no ABSTRACT Fluid-saturated granular and porous layers can undergo liquefaction and lose their shear

  3. Granular flow in pebble-bed nuclear reactors: Scaling, Dust Generation, and Stress

    E-Print Network [OSTI]

    Rycroft, Chris H.

    Granular flow in pebble-bed nuclear reactors: Scaling, Dust Generation, and Stress Chris H. Keywords: granular flow, dust generation, numerical methods 1. Introduction Pebble-bed nuclear reactors prototypes of pebble-bed reactors, significant quantities of graphite dust have been observed due to rubbing

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

    E-Print Network [OSTI]

    Reis, Pedro Miguel

    of a granular ensemble requires an energy input which typically takes the form of vibration or shear 4 statistical mechanics 3 . Interactions between granular particles are intrinsically dissipative since energy for many applications. These include areas such as agriculture, geophysics, material science, and several

  5. Class-dependent rough-fuzzy granular space, dispersion index and classification

    E-Print Network [OSTI]

    Pal, Sankar Kumar

    granular computing Soft computing Pattern recognition Remote sensing a b s t r a c t A new rough-fuzzy model for pattern classification based on granular computing is described in the present article. In this model, we propose the formulation of class-dependent granules in fuzzy environment. Fuzzy membership

  6. Towards the zero-surface-tension limit in granular fingering instability

    E-Print Network [OSTI]

    Loss, Daniel

    LETTERS Towards the zero-surface-tension limit in granular fingering instability XIANG CHENG*, LEI Hele­Shaw system to explore the zero-surface-tension property of granular `fluids'16 . We demonstrate-unrealizable singular hydrodynamics predicted in the zero-surface-tension limit of normal fluid fingering2,17­23 . Above

  7. Surface wave acoustics of granular packing under gravity

    SciTech Connect (OSTI)

    Clement, Eric; Andreotti, Bruno [PMMH, ESPCI, CNRS (UMR 7636) and Univ. Paris 6 and Paris 7, 10 rue Vauquelin, 75005 Paris (France); Bonneau, Lenaic [PMMH, ESPCI, CNRS (UMR 7636) and Univ. Paris 6 and Paris 7, 10 rue Vauquelin, 75005 Paris (France)

    2009-06-18T23:59:59.000Z

    Due to the non-linearity of Hertzian contacts, the speed of sound in granular matter increases with pressure. For a packing under gravity and in the presence of a free surface, bulk acoustic waves cannot propagate due to the inherent refraction toward the surface (the mirage effect). Thus, only modes corresponding to surface waves (Raleigh-Hertz modes) are able to propagate the acoustic signal. First, based on a non-linear elasticity model, we describe the main features associated to these surface waves. We show that under gravity, a granular packing is from the acoustic propagation point of view an index gradient waveguide that selects modes of two distinct families i.e. the sagittal and transverse waves localized in the vicinity of the free surface. A striking feature of these surface waves is the multi-modal propagation: for both transverse and sagittal waves, we show the existence of a infinite but discrete series of propagating modes. In each case, we determine the mode shape and and the corresponding dispersion relation. In the case of a finite size system, a geometric waveguide is superimposed to the index gradient wave guide. In this later case, the dispersion relations are modified by the appearance of a cut-off frequency that scales with depth. The second part is devoted to an experimental study of surface waves propagating in a granular packing confined in a long channel. This set-up allows to tune a monomodal emission by taking advantage of the geometric waveguide features combined with properly designed emitters. For both sagittal and transverses waves, we were able to isolate a single mode (the fundamental one) and to plot the dispersion relation. This measurements agree well with the Hertzian scaling law as predicted by meanfield models. Furthermore, it allows us to determine quantitatively relations on the elastic moduli. However, we observe that our data yield a shear modulus abnormally weak when compared to several meanfield predictions.

  8. Southern Ocean Iron Experiment (SOFex)

    SciTech Connect (OSTI)

    Coale, Kenneth H.

    2005-07-28T23:59:59.000Z

    The Southern Ocean Iron Experiment (SOFeX) was an experiment decades in the planning. It's implementation was among the most complex ship operations that SIO has been involved in. The SOFeX field expedition was successful in creating and tracking two experimentally enriched areas of the Southern Ocean, one characterized by low silicic acid, one characterized by high silicic acid. Both experimental sites were replete with abundant nitrate. About 100 scientists were involved overall. The major findings of this study were significant in several ways: (1) The productivity of the southern ocean is limited by iron availability. (2) Carbon uptake and flux is therefore controlled by iron availability (3) In spite of low silicic acid, iron promotes non-silicious phytoplankton growth and the uptake of carbon dioxide. (4) The transport of fixed carbon from the surface layers proceeds with a C:N ratio that would indicate differential remineralization of nitrogen at shallow depths. (5) These finding have major implications for modeling of carbon export based on nitrate utilization. (6) The general results of the experiment indicate that, beyond other southern ocean enrichment experiments, iron inputs have a much wider impact of productivity and carbon cycling than previously demonstrated. Scientific presentations: Coale, K., Johnson, K, Buesseler, K., 2002. The SOFeX Group. Eos. Trans. AGU 83(47) OS11A-0199. Coale, K., Johnson, K. Buesseler, K., 2002. SOFeX: Southern Ocean Iron Experiments. Overview and Experimental Design. Eos. Trans. AGU 83 (47) OS22D-01. Buesseler, K.,et al. 2002. Does Iron Fertilization Enhance Carbon Sequestration? Particle flux results from the Southern Ocean Iron Experiment. Eos. Trans. AGU 83 (47), OS22D-09. Johnson, K. et al. 2002. Open Ocean Iron Fertilization Experiments From IronEx-I through SOFeX: What We Know and What We Still Need to Understand. Eos. Trans. AGU 83 (47), OS22D-12. Coale, K. H., 2003. Carbon and Nutrient Cycling During the Southern Ocean Iron Enrichment Experiments. Seattle, WA. Geological Society of America. Coale, K., 2003. Open Ocean Iron Enrichment Experiments: What they have told us, what they have not. American Society for Limnology and Oceanography and The Oceanography Society, Honolulu, February 2004. Coale, K., 2004. Recent Research from the Southern Ocean Iron Experiment (SOFeX), in Taking the Heat: What is the impact of ocean fertilization on climate and ocean ecology? Science of earth and sky. AAAS, February 12-16, Seattle, WA

  9. 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

    2015-02-28T23:59:59.000Z

    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.

  10. Contact dynamics in a gently vibrated granular pile

    E-Print Network [OSTI]

    Alexandre Kabla; Georges Debregeas

    2003-03-26T23:59:59.000Z

    We use multi-speckle diffusive wave spectroscopy (MSDWS) to probe the micron-scale dynamics of a granular pile submitted to discrete gentle taps. The typical time-scale between plastic events is found to increase dramatically with the number of applied taps. Furthermore, this microscopic dynamics weakly depends on the solid fraction of the sample. This process is strongly analogous to the aging phenomenon observed in thermal glassy systems. We propose a heuristic model where this slowing down mechanism is associated with a slow evolution of the distribution of the contact forces between particles. This model accounts for the main features of the observed dynamics.

  11. Energy trapping and shock disintegration in a composite granular medium

    E-Print Network [OSTI]

    C. Daraio; V. F. Nesterenko; E. B. Herbold; S. Jin

    2005-09-24T23:59:59.000Z

    Granular materials demonstrate a strongly nonlinear behavior influencing the wave propagation in the medium. We report the first experimental observation of impulse energy confinement and the resultant disintegration of shock and solitary waves. The medium consists of alternating ensambles of high-modulus vs orders of magnitude lower modulus chains of different masses. The trapped energy is contained within the "softer" portions of the composite chain and is slowly released in the form of weak, separated pulses over an extended period of time. This effect is enhanced by using a specific group assembly and superimposed force.

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

    E-Print Network [OSTI]

    R. Candelier; O. Dauchot; G. Biroli

    2009-01-22T23:59:59.000Z

    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.

  13. Magnetoresistance oscillations in superconducting granular niobium nitride nanowires.

    SciTech Connect (OSTI)

    Patel, U.; Xiao, Z. L.; Gurevich, A.; Avci, S.; Hua, J.; Divan, R.; Welp, U.; Kwok, W. K.; Northern Illinois Univ.; National High Magnetic Field Lab.

    2009-01-01T23:59:59.000Z

    We report on magnetoresistance oscillations in superconducting NbN{sub x} nanowires synthesized through ammonia gas annealing of NbSe{sub 3} precursor nanostructures. Even though the transverse dimensions of the nanowires are much larger than the superconducting coherence length, the voltage-current characteristics of these nanowires at low temperatures are reminiscent of one-dimensional superconductors where quantum phase slips are associated with the origin of dissipation. We show that both the magnetoresistance oscillations and voltage-current characteristics observed in this work result from the granular structure of our nanowires.

  14. The nature of quasistatic deformation in granular materials

    E-Print Network [OSTI]

    Jean-Noël Roux

    2009-01-15T23:59:59.000Z

    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.

  15. Shear zone refraction and deflection in layered granular materials

    E-Print Network [OSTI]

    Tamas Borzsonyi; Tamas Unger; Balazs Szabo

    2009-12-09T23:59:59.000Z

    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.

  16. KNOTS AND RANDOM WALKS IN VIBRATED GRANULAR CHAINS

    SciTech Connect (OSTI)

    E. BEN-NAIM; ET AL

    2000-08-01T23:59:59.000Z

    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.

  17. Fractal dimension analysis in a highly granular calorimeter

    E-Print Network [OSTI]

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

    2015-01-01T23:59:59.000Z

    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.

  18. Critical scaling near jamming transition for frictional granular particles

    E-Print Network [OSTI]

    Michio Otsuki; Hisao Hayakawa

    2011-03-30T23:59:59.000Z

    The critical rheology of sheared frictional granular materials near jamming transition is numer- ically investigated. It is confirmed that there exist a true critical density which characterizes the onset of the yield stress, and two fictitious critical densities which characterize the scaling laws of rheological properties. We find the existence of a hysteresis loop between two of the critical densities for each friction coefficient. It is noteworthy that the critical scaling law for frictionless jamming transition seems to be still valid even for frictional jamming despite using fictitious critical density values.

  19. Westinghouse standleg moving granular bed filter development program

    SciTech Connect (OSTI)

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

    1994-10-01T23:59:59.000Z

    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.

  20. Fluctuations, Correlation and Representative Elementary Volume (REV) in Granular Materials

    E-Print Network [OSTI]

    P. Evesque

    2005-06-15T23:59:59.000Z

    In general, the mechanics of granular matter is described using continuum mechanics approach; this requires to introduce the concepts of stress and strain, which are averaged quantities, so that this needs also to introduce the notion of representative elementary volume (REV) above which averaged quantities have some physical meaning. As local quantities fluctuate spatially in granular matter; a local measure of stress and strain shall exhibit fluctuations too, whose typical amplitude depends on the sampling size L. This paper discusses this problem and the causes for large scale correlation. The mean stress s applied to a plane surface of size L*L is calculated and its fluctuation amplitude Ds is found when local forces are not correlated; it is found that Ds/s scales as 1/L . It is shown also that large scale fluctuations of stress can always be interpreted as an inhomogeneous stress field and that static equilibrium modifies the mean stress applied to a rod (in 2d), even if it does not perturb the contact force distribution. This last result is compared to experiment, which indicates that the number N of contacts per rod (in 2d) is 2

  1. Evolution of shock instability in granular gases with viscoelastic collisions

    E-Print Network [OSTI]

    Nick Sirmas; Matei Radulescu

    2014-09-04T23:59:59.000Z

    Shocks in granular media have been shown to develop instabilities. We address the role that early stages of shock development have on this type of instability. We look at the evolution of shock waves driven by a piston in a dilute system of smooth inelastic disks, using both discrete-particle and continuum modelling. To mimic a realistic granular gas, viscoelastic collisions are approximated with an impact velocity threshold $u^*$ needed for inelastic collisions to occur. We show that behaviour of the shock evolution is dependent on the ratio of piston velocity to impact velocity threshold $u_p/u^*$, and the coefficient of restitution $\\varepsilon$. For $u_p/u^*=2.0$, we recover shock evolution behaving similar to that observed in purely inelastic media. This is characterized by a short period where the shock front pulls towards the piston before attaining a developed structure. No pullback is seen for $u_p/u^*=1.0$. Results show the onset of instability for these stronger shocks during this evolving stage. These results suggest that the early stages of shock evolution play an important role in the shock instability.

  2. Dynamical mechanism for non-locality in dense granular flows

    E-Print Network [OSTI]

    M. Bouzid; M. Trulsson; P. Claudin; E. Clement; B. Andreotti

    2014-05-09T23:59:59.000Z

    The dynamical mechanism at the origin of the non-local rheology of dense granular flows is investigated trough discrete element simulations. We show that the influence of a shear band on the mechanical behavior of a distant zone is contained in the spatial variations observed in the network of granular contacts. Using a micro-rheology technique, we establish that the exponential responses hence obtained, do not proof the validity of a mechanical activation process as previously suggested, but stem from the spatial relaxation of the shear rate as a direct consequence of a macroscopic non-local constitutive relation. Finally, by direct visualization of the local relaxation processes, we dismiss the kinetic elasto-plastic picture, where a flow is conceived as a quasi-static sequence of localized plastic events interacting through the stress field. We therefore conclude in favor of the jamming scenario, where geometrical constrains lead to coherent non-affine displacements along floppy modes, inherently non-local.

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

    DOE Patents [OSTI]

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

    1999-01-01T23:59:59.000Z

    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.

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

    DOE Patents [OSTI]

    Sarma, B.; Downing, K.B.

    1999-03-23T23:59:59.000Z

    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 (1) at least some of the iron oxide to be chemically reduced, (2) a bath of molten iron to be created and stirred in the bottom of the reactor, surmounted by a layer of slag, and (3) 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: (1) keep the temperature of the molten iron at or below about 1550 C and (2) keep the slag weight at or above about 0.8 ton per square meter. 13 figs.

  5. Iron catalyzed coal liquefaction process

    DOE Patents [OSTI]

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

    1983-01-01T23:59:59.000Z

    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.

  6. Iron and Steel Energy Intensities

    U.S. Energy Information Administration (EIA) Indexed Site

    If you are having trouble, call 202-586-8800 for help. Home > >Energy Users > Energy Efficiency Page > Iron and Steel Energy Intensities First Use of Energy Blue Bullet First Use...

  7. Process for the synthesis of iron powder

    DOE Patents [OSTI]

    Not Available

    1982-03-06T23:59:59.000Z

    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.

  8. Process for the synthesis of iron powder

    DOE Patents [OSTI]

    Welbon, W.W.

    1983-11-08T23:59:59.000Z

    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.

  9. Granular nanostructures and magnetic characteristics of FePt-TiO{sub 2}/FePt-C stacked granular films

    SciTech Connect (OSTI)

    Ono, Takuya, E-mail: ono-takuya@fujielectric.co.jp; Moriya, Tomohiro [Fuji Electric Co. Ltd., Tokyo 191-8502 (Japan); Frontier Research Institute for Interdisciplinary Sciences (FRIS), Tohoku University, Miyagi 980-8578 (Japan); Hatayama, Masatoshi [Frontier Research Institute for Interdisciplinary Sciences (FRIS), Tohoku University, Miyagi 980-8578 (Japan); Kikuchi, Nobuaki; Okamoto, Satoshi; Kitakami, Osamu [Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, Miyagi 980-8577 (Japan); Shimatsu, Takehito [Frontier Research Institute for Interdisciplinary Sciences (FRIS), Tohoku University, Miyagi 980-8578 (Japan); Research institutes of Electrical Communication (RIEC), Tohoku University, Miyagi 980-8577 (Japan)

    2014-05-07T23:59:59.000Z

    To realize a granular film composed of L1{sub 0}-FePt grains with high uniaxial magnetic anisotropy energy, K{sub u}, and segregants for heat-assisted magnetic recording, the FePt-TiO{sub 2}/FePt-C stacked film was investigated. The FePt-TiO{sub 2}/FePt-C stacked film has well-isolated granular structure with average grain size of 6.7?nm because the FePt-TiO{sub 2} film follows the FePt-C template film in microstructural growth. However, the K{sub u} value is quite low for total thickness of 9?nm: 5?×?10{sup 6} erg/cm{sup 3}. Exploration of the thickness dependence of L1{sub 0}-FePt(001) peaks in XRD spectra and cross-sectional TEM images suggest that degradation of the L1{sub 0} ordering appears near the middle of the FePt-TiO{sub 2} layer. The EDX-STEM mapping reveals that Ti atoms exist within the FePt grains in addition to the grain boundary. This indicates the possibility that TiO{sub 2} tends to be incorporated into the FePt grains and that it prevents L1{sub 0}-ordering of the FePt grains along the normal-to-plane direction.

  10. Dense granular flow around a penetrating object: Experiments and hydrodynamic model

    E-Print Network [OSTI]

    Antoine Seguin; Yann Bertho; Philippe Gondret; Jerome Crassous

    2011-06-24T23:59:59.000Z

    We present in this Letter experimental results on the bidimensional flow field around a cylinder penetrating into dense granular matter together with drag force measurements. A hydrodynamic model based on extended kinetic theory for dense granular flow reproduces well the flow localization close to the cylinder and the corresponding scalings of the drag force, which is found to not depend on velocity, but linearly on the pressure and on the cylinder diameter and weakly on the grain size. Such a regime is found to be valid at a low enough "granular" Reynolds number.

  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

    2007-07-17T23:59:59.000Z

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

    E-Print Network [OSTI]

    Tye, Jesse Wayne

    2009-05-15T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    Tye, Jesse Wayne

    2009-05-15T23:59:59.000Z

    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...

  14. anaemia iron deficiency: Topics by E-print Network

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

    Bhaniani, Amit 2009-05-29 5 Correcting Iron Deficiencies in Soybean with Foliar Iron Fertilizer Engineering Websites Summary: Correcting Iron Deficiencies in Soybean with Foliar...

  15. Arches and contact forces in a granular pile

    E-Print Network [OSTI]

    C. Manuel Carlevaro; Luis A. Pugnaloni

    2012-05-29T23:59:59.000Z

    Assemblies of granular particles mechanically stable under their own weight contain arches. These are structural units identified as sets of mutually stable grains. It is generally assumed that these arches shield the weight above them and should bear most of the stress in the system. We test such hypothesis by studying the stress born by in-arch and out-of-arch grains. We show that, indeed, particles in arches withstand larger stresses. In particular, the isotropic stress tends to be larger for in-arch-grains whereas the anisotropic component is marginally distinguishable between the two types of particles. The contact force distributions demonstrate that an exponential tail (compatible with the maximization of entropy under no extra constraints) is followed only by the out-of-arch contacts. In-arch contacts seem to be compatible with a Gaussian distribution consistent with a recently introduced approach that takes into account constraints imposed by the local force balance on grains.

  16. Reflection and Exclusion of Shear Zones in Inhomogeneous Granular Materials

    E-Print Network [OSTI]

    Tamas Borzsonyi; Tamas Unger; Balazs Szabo; Sandra Wegner; Frank Angenstein; Ralf Stannarius

    2011-08-17T23:59:59.000Z

    Shear localization in granular materials is studied experimentally and numerically. The system consists of two material layers with different effective frictions. The presence of the material interface leads to a special type of "total internal reflection" of the shear zone. In a wide range of configurations the reflection is characterized by a fixed angle which is analogous to the critical angle of refraction in optics. The zone leaves and reenters the high friction region at this critical angle and in between it stays near the interface in the low friction region. The formalism describing the geometry of the shear zones and that of refracted and reflected light beams is very similar. For the internal visualization of shear localization two independent experimental techniques were used (i) excavation and (ii) Magnetic Resonance Imaging.

  17. Heating mechanism affects equipartition in a binary granular system

    E-Print Network [OSTI]

    Hong-Qiang Wang; Narayanan Menon

    2008-03-08T23:59:59.000Z

    Two species of particles in a binary granular system typically do not have the same mean kinetic energy, in contrast to the equipartition of energy required in equilibrium. We investigate the role of the heating mechanism in determining the extent of this non-equipartition of kinetic energy. In most experiments, different species of particle are unequally heated at the boundaries. We show by event-driven simulations that this differential heating at the boundary influences the level of non-equipartition even in the bulk of the system. This conclusion is fortified by studying a numerical model and a solvable stochastic model without spatial degrees of freedom. In both cases, even in the limit where heating events are rare compared to collisions, the effect of the heating mechanism persists.

  18. Spanning the Scales of Granular Materials: Microscopic Force Imaging

    E-Print Network [OSTI]

    Nicolas Brodu; Joshua A. Dijksman; Robert P. Behringer

    2014-08-11T23:59:59.000Z

    If you walk on sand, it supports your weight. How do the disordered forces between particles in sand organize, to keep you from sinking? This simple question is surprisingly difficult to answer experimentally: measuring forces in three dimensions, between deeply buried grains, is challenging. We describe here experiments in which we have succeeded in measuring forces inside a granular packing subject to controlled deformations. We connect the measured micro-scale forces to the macro-scale packing force response with an averaging, mean field calculation. This calculation explains how the combination of packing structure and contact deformations produce the unexpected mechanical response of the packing, and reveals a surprising microscopic particle deformation enhancement mechanism.

  19. 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

    2005-09-05T23:59:59.000Z

    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.

  20. MICROMECHANICS BASED CONSTITUTIVE MODEL FOR GRANULAR SOLIDS AND ITS IMPLEMENTATION INTO MESHFREE NUMERICAL METHOD

    E-Print Network [OSTI]

    Lusk, Miriam Beatriz

    2011-12-31T23:59:59.000Z

    To capture the fracture process and non-linear behavior at the element and structural level of granular materials, concrete, under the presence of pre-existing imperfections, a constitutive model and a mesh free method is ...

  1. 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 ...

  2. Mach cone in a shallow granular fluid Patrick Heil,* E. C. Rericha,

    E-Print Network [OSTI]

    Goldman, Daniel I.

    on the Von Kármán vortex street of flow past a cylinder, the drag force reduction due to tur- bulence- ments on granular flow past obstacles provide good geom- etries to test the emerging hydrodynamic theory

  3. Investigating the angle or response and maximum stability of a cohesive granular pile

    E-Print Network [OSTI]

    Nowak, Sara Alice, 1982-

    2004-01-01T23:59:59.000Z

    In this thesis, I investigate the static and dynamic properties of a granular heap made cohesive by an interstitial fluid. I present the results of experimental work measuring the maximum angle of stability and the angle ...

  4. Particle scale and bulk scale investigation of granular piles and silos 

    E-Print Network [OSTI]

    Ai, Jun

    2010-01-01T23:59:59.000Z

    Granular materials are in abundance both in nature and in industry. They are of considerable interest to both the engineering and physics communities, due to their practical importance and many unsolved scientific ...

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

    E-Print Network [OSTI]

    Rangel, Roberto Carlos

    2006-01-01T23:59:59.000Z

    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 ...

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

    E-Print Network [OSTI]

    Wang, Ruopeng, 1972-

    2005-01-01T23:59:59.000Z

    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 ...

  7. Diffusing-wave spectroscopy study of microscopic dynamics of three-dimensional granular systems

    E-Print Network [OSTI]

    Pak, Hyuk Kyu

    fluidized-granular systems, such as; channel flow, gas-fluidized beds, avalanche flow, and vibro-fluidized, such as magnetic resonance imaging (MRI),21,22 X-ray microtomography,23,24 electrical capacitance tomography (ECT

  8. Jamming during the discharge of granular matter from a silo Iker Zuriguel,1,

    E-Print Network [OSTI]

    Weeks, Eric R.

    the idea of "jamming transition," character- ized by the sudden arrest of the particle dynamics. Glass transitions, colloidal gels, foams, as well as granular flows, traffic, and stampedes are included among

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

    E-Print Network [OSTI]

    Lang, Richard Anthony

    2004-09-30T23:59:59.000Z

    NUMERICAL SIMULATION OF COMMINUTION IN GRANULAR MATERIALS WITH AN APPLICATION TO FAULT GOUGE EVOLUTION A Thesis by RICHARD ANTHONY LANG Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE May 2002 Major Subject: Geophysics NUMERICAL SIMULATION OF COMMINUTION IN GRANULAR MATERIALS WITH AN APPLICATION TO FAULT GOUGE EVOLUTION A Thesis by RICHARD ANTHONY LANG Submitted...

  10. 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

    2014-10-20T23:59:59.000Z

    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.

  11. DOMAIN PATTERNS AND REVERSALS BY WALL MOVEMENTS OF THIN FILMS OF IRON AND NICKEL IRON

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    310 DOMAIN PATTERNS AND REVERSALS BY WALL MOVEMENTS OF THIN FILMS OF IRON AND NICKEL IRON By C. E directions but in the case of the nickel-iron film the reversal of magnetization in the perpendicular domain reversals in nickel-iron films observed by the Kerr effect, and that of Williams and Sherwood [2

  12. Good Sources of Nutrients: Iron

    E-Print Network [OSTI]

    Scott, Amanda; Replogle, Jacqueline

    2008-08-28T23:59:59.000Z

    ENP-2881 08-08 Good Sources of Nutrients Iron Buenas fuentes de nutrientes Hierro La funci?n del hierro Transporta ox?geno en la sangre para que su ? cuerpo tenga energ?a Facilita crecimiento? Proporciona energ?a que ayuda a los ni?os a ? jugar y...

  13. Shear Jamming in Granular Experiments without Basal Friction

    E-Print Network [OSTI]

    Hu Zheng; Joshua A. Dijksman; Robert P. Behringer

    2014-08-08T23:59:59.000Z

    Jammed states of frictional granular systems can be induced by shear strain at densities below the isostatic jamming density ($\\phi_c$). It remains unclear, however, how much friction affects this so-called shear-jamming. Friction appears in two ways in this type of experiment: friction between particles, and friction between particles and the base on which they rest. Here, we study how particle-bottom friction, or basal friction, affects shear jamming in quasi-two dimensional experiments. In order to study this issue experimentally, we apply simple shear to a disordered packing of photoelastic disks. We can tune the basal friction of the particles by immersing the particles in a density matched liquid, thus removing the normal force, hence the friction, between the particles and base. We record the overall shear stress, and particle motion, and the photoelastic response of the particles. We compare the shear response of dry and immersed samples, which enables us to determine how basal friction affects shear jamming. Our findings indicate that changing the basal friction shifts the point of shear jamming, but it does not change the basic phenomenon of shear jamming.

  14. Granular-bed-filter development program, Phase II. Final report

    SciTech Connect (OSTI)

    Guillory, J.; Cooper, J.; Ferguson, J.; Goldbach, G.; Placer, F.

    1983-05-01T23:59:59.000Z

    The high-temperature moving bed granular filter (GBF) program at Combustion Power Company (CPC) commenced in 1977. Its purpose was to investigate, for the Department of Energy, the filtration performance of the GBF for application to coal-fired PFBC turbine systems. The GBF test system was successfully operated on 1500/sup 0/F to 1600/sup 0/F gases produced from an atmospheric pressure coal-fired fluidized bed combustor. Overall collection efficiencies above 99% and submicron collection efficiencies above 96% were consistently demonstrated in over 1500 hours of high-temperature testing. Alkali content of the hot gases was also measured to evaluate aluminosilicate additives for controlling alkali emissions. Operational and performance stability under upset conditions (ten times normal inlet loading and 125% of design gas flowrate) was also demonstrated experimentally. A computer-based GBF performance model was developed. It predicts overall particle capture within +- 5%. Gas flow streamlines and isobars are computer generated from theoretical principles and particle capture is based on the most recent empirical models. The effects of elevated pressure on efficiency and filter pressure drop are included in the model. A modular approach was adopted for GBF scale-up to commercial size systems using elements of the same size tested in this program. Elements can be readily packaged into 30,000 acfm modules at a projected equipment cost of approximately $27 per acfm.

  15. Fluid-driven deformation of a soft granular material

    E-Print Network [OSTI]

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

    2015-02-24T23:59:59.000Z

    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.

  16. Physical-chemical characterization of sludge and granular materials from a vertical flow constructed wetland for municipal wastewater treatment

    E-Print Network [OSTI]

    Boyer, Edmond

    Physical-chemical characterization of sludge and granular materials from a vertical flow considered for phosphorus removal as well. In this article, sludge and granular materials sampled from analyses showed that phosphorus was predominantly captured in the sludge layer accumulated at the surface

  17. PHYSICAL REVIEW E 85, 051309 (2012) Relation between self-organized criticality and grain aspect ratio in granular piles

    E-Print Network [OSTI]

    Wijngaarden, Rinke J.

    2012-01-01T23:59:59.000Z

    ratio in granular piles D. V. Denisov, Y. Y. Villanueva, K. A. Lorincz, S. May, and R. J. Wijngaarden-organized criticality (SOC) occurs in granular piles composed of different grains, namely, rice, lentils, quinoa fluctuation (and thus bigger avalanches) happen in piles consisting of grains with larger aspect ratio. DOI

  18. Ageing of a granular pile induced by thermal cycling Thibaut Divoux, Ion Vassilief, Herv Gayvallet and Jean-Christophe Gminard

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Ageing of a granular pile induced by thermal cycling Thibaut Divoux, Ion Vassilief, Hervé Gayvallet of temperature, even of a few degrees in amplitude, induce the ageing of a granular pile. In particular, we of the pile with the number of cycles. The present contribution nicely supplements a recent article we

  19. ccsd-00083932,version1-4Jul2006 The S shape of a granular pile in a rotating drum

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    ccsd-00083932,version1-4Jul2006 The S shape of a granular pile in a rotating drum Nicolas Taberlet1 (Dated: July 4, 2006) The shape of a granular pile in a rotating drum is investigated. Using Discrete reveals a dimensionless number which quantifies the influence of the end plates on the shape of the pile

  20. PHYSICAL REVIEW E 83, 061301 (2011) Simulation of a Casimir-like effect in a granular pile with avalanches

    E-Print Network [OSTI]

    Wijngaarden, Rinke J.

    2011-01-01T23:59:59.000Z

    PHYSICAL REVIEW E 83, 061301 (2011) Simulation of a Casimir-like effect in a granular pile-Tang-Wiesenfeld model for sand piles, we simulate a Casimir-like effect in a granular pile with avalanches. Results of walls placed on the slope of the pile is investigated, but the prevention effect is found

  1. Granular Brownian motor This article has been downloaded from IOPscience. Please scroll down to see the full text article.

    E-Print Network [OSTI]

    Weeks, Eric R.

    Granular Brownian motor This article has been downloaded from IOPscience. Please scroll down to see) 50003 www.epljournal.org doi: 10.1209/0295-5075/77/50003 Granular Brownian motor B. Cleuren and C. Van. ­ Brownian motors are spatially asymmetric constructions that, operating under nonequi- librium conditions

  2. NMR experiments on a three-dimensional vibrofluidized granular medium Chao Huan, Xiaoyu Yang,* and D. Candela

    E-Print Network [OSTI]

    Walsworth, Ronald L.

    coupled with one-dimensional magnetic resonance imaging. The system consisted of mustard seeds vibrated-dimensional granular system fluidized by vertical container vibrations was studied using pulsed field gradient NMR.05.Rm I. INTRODUCTION One of the basic granular flow phenomena is the creation of a fluidized state

  3. Iron production maintenance effectiveness system

    SciTech Connect (OSTI)

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

    1996-12-31T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Pierre Jop; Yoël Forterre; Olivier Pouliquen

    2014-10-16T23:59:59.000Z

    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.

  5. Collective behavior in a granular jet: Emergence of a liquid with zero surface-tension

    E-Print Network [OSTI]

    Xiang Cheng; German Varas; Daniel Citron; Heinrich M. Jaeger; Sidney R. Nagel

    2007-06-14T23:59:59.000Z

    We perform the analog to the "water bell" experiment using non-cohesive granular material. When a jet of granular material, many particles wide, rebounds from a fixed cylindrical target, it deforms into a sharply-defined sheet or cone with a shape that mimics a liquid with zero surface tension. The particulate nature of granular material becomes apparent when the number of particles in the cross-section of the jet is decreased and the emerging sheets and cones broaden and gradually disintegrate into a broad spray. This experiment has its counterpart in the behavior of the quark-gluon plasma generated by collisions of gold ions at the Relativistic Heavy Ion Collider. There a high density of inter-particle collisions gives rise to collective behavior that has also been described as a liquid.

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

    E-Print Network [OSTI]

    Ricardo J. Alonso; Bertrand Lods

    2010-05-31T23:59:59.000Z

    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.

  7. Continuum modeling and simulation of granular flows through their many phases

    E-Print Network [OSTI]

    Sachith Dunatunga; Ken Kamrin

    2014-11-20T23:59:59.000Z

    We propose and numerically implement a constitutive framework for granular media that allows the material to traverse through its many common phases during the flow process. When dense, the material is treated as a pressure sensitive elasto-viscoplastic solid obeying a yield criterion and a plastic flow rule given by the $\\mu(I)$ inertial rheology of granular materials. When the free volume exceeds a critical level, the material is deemed to separate and is treated as disconnected, stress-free media. A Material Point Method (MPM) procedure is written for the simulation of this model and many demonstrations are provided in different geometries. By using the MPM framework, extremely large strains and nonlinear deformations, which are common in granular flows, are representable. The method is verified numerically and its physical predictions are validated against known results.

  8. Critical Phenomena in Driven Granular Matter: Jamming and Glassy Behavior - Final Report

    SciTech Connect (OSTI)

    Teitel, Stephen

    2013-02-20T23:59:59.000Z

    Granular materials, such as powders, seeds, grains, sand, rocks, etc., are ubiquitous both in nature and in industrial processes. At the scale of individual grains, granular systems are particularly simple: particles interact only when they touch. But when viewed in the aggregate, granular systems can display complex behavior. In particular, as the volume packing fraction of the grains increases, the system undergoes a jamming transition from a flowing liquid to a disordered but rigid solid. We study the critical behavior of such systems near the jamming transition using numerical simulations of a simple model of soft-core, bidisperse, frictionless disks in two dimensions. We seek to understand the structural and transport properties of such systems under a variety of physical perturbations such as steady state shear driven flow, and finite thermal fluctuations.

  9. Sphere penetration by impact in a granular medium: A collisional process

    E-Print Network [OSTI]

    Antoine Seguin; Yann Bertho; Philippe Gondret; Jerome Crassous

    2009-11-26T23:59:59.000Z

    The penetration by a gravity driven impact of a solid sphere into a granular medium is studied by two-dimensional simulations. The scaling laws observed experimentally for both the final penetration depth and the stopping time with the relevant physical parameters are here recovered numerically without the consideration of any solid friction. Collisional processes are thus found as essential in explaining the physics of the qualitatively observed phenomena whereas frictional processes can only be considered as secondary effects in the granular penetration by impact.

  10. Iron speciation and its biological availability in seawater: A workshop

    SciTech Connect (OSTI)

    Wells, M.L.; Bruland, K.W.

    1995-09-08T23:59:59.000Z

    This workshop brought together marine chemists with expertise in iron chemistry and biologists with expertise in the role of iron in phytoplankton production to discuss controversies regarding the role of iron in oceanic primary productivity and global climatic change. A new paradigm for marine iron biogeochemistry was generated. The five major new items within this paradigm included (1) the nature of iron inputs to the sea, (2) chemical speciation of iron in seawater, (3) relationships between iron chemistry and marine microbial community dynamics, (4) adaptations of marine microbes to iron input, and (5) ecological and biogeochemical implications of changes in iron supply to the sea.

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

    E-Print Network [OSTI]

    Gupton, Paul Stephen

    1961-01-01T23:59:59.000Z

    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... of MASTER OF SCIENCE January 1961 Major Subject Nuclear Engineering THE MAGNETIC PROPERTIES OF THE IRON-RICH, IRON-NICKEL-ZINC ALLOYS A Thesis By Paul Stephen Gupton Approved as to style and content by: (Chairman of Ittee) Head of Oepartment...

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

    E-Print Network [OSTI]

    Seaman, John C.

    1990-01-01T23:59:59.000Z

    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...

  13. Correcting Iron Deficiencies in Grain Sorghum

    E-Print Network [OSTI]

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

    1996-02-20T23:59:59.000Z

    tial for chlorosis when grown on high- ese hybrids lack the ability to fully specif_ied and the iron should be determined by atomic absorption or a method that best indicates available iron in production f_ields. The ICAP (Inductive Coupled Argon Plasma...) method of analysis is prone to evaluate some of the iron on the clay structure as well as suspended iron. Therefore, adequate (but false) values are sometimes reported. One way to avoid this problem is to air-dry the samples instead of oven-drying them...

  14. Iron oxyhydroxide mineralization on microbial extracellular polysaccharides

    SciTech Connect (OSTI)

    Chan, Clara S.; Fakra, Sirine C.; Edwards, David C.; Emerson, David; Banfield, Jillian F.

    2010-06-22T23:59:59.000Z

    Iron biominerals can form in neutral pH microaerophilic environments where microbes both catalyze iron oxidation and create polymers that localize mineral precipitation. In order to classify the microbial polymers that influence FeOOH mineralogy, we studied the organic and mineral components of biominerals using scanning transmission X-ray microscopy (STXM), micro X-ray fluorescence ({mu}XRF) microscopy, and high-resolution transmission electron microscopy (HRTEM). We focused on iron microbial mat samples from 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 mineralized products of an iron-oxidizing, stalk-forming bacterial culture isolated from the mine. In both natural and cultured samples, microbial polymers were found to be acidic polysaccharides with carboxyl functional groups, strongly spatially correlated with iron oxyhydroxide distribution patterns. Organic fibrils collect FeOOH and control its recrystallization, in some cases resulting in oriented crystals with high aspect ratios. The impact of polymers is particularly pronounced as the materials age. Synthesis experiments designed to mimic the biomineralization processes show that the polysaccharide carboxyl groups bind dissolved iron strongly but release it as mineralization proceeds. Our results suggest that carboxyl groups of acidic polysaccharides are produced by different microorganisms to create a wide range of iron oxyhydroxide biomineral structures. The intimate and potentially long-term association controls the crystal growth, phase, and reactivity of iron oxyhydroxide nanoparticles in natural systems.

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

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

    Nanostructure, Chemistry and Crystallography of Iron Nitride Magnetic Materials by Ultra-High-Resolution Electron Microscopy and Related Methods DOE 2011 Vehicle Technologies...

  16. Lithium Insertion Chemistry of Some Iron Vanadates

    E-Print Network [OSTI]

    Patoux, Sebastien; Richardson, Thomas J.

    2008-01-01T23:59:59.000Z

    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

  17. 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)

    1999-01-01T23:59:59.000Z

    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.

  18. Lithium Insertion Chemistry of Some Iron Vanadates

    E-Print Network [OSTI]

    Patoux, Sebastien; Richardson, Thomas J.

    2008-01-01T23:59:59.000Z

    G.Pistoia (Eds. ), Lithium batteries, Science & Technology,Keywords: Lithium batteries, iron vanadates, insertionelectrode materials for lithium batteries, (mostly layered

  19. 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...

  20. Role of microbial iron reduction in the dissolution of iron hydroxysulfate minerals

    E-Print Network [OSTI]

    and for radionuclides such as 226 Ra. These mineral-bound contaminants are considered immobilized under oxic conditions in mineral dissolution, releasing these bound contaminants. Reduction of structural sulfate in the ironRole of microbial iron reduction in the dissolution of iron hydroxysulfate minerals Elizabeth J. P

  1. Modeling Red Blood Cell and Iron Dynamics in Patients Undergoing Periodic EPO and Iron Treatments

    E-Print Network [OSTI]

    Modeling Red Blood Cell and Iron Dynamics in Patients Undergoing Periodic EPO and Iron Treatments H in the kidneys, that stimulates red blood cell (RBC) production. Without intervention, patients suffer from, erythrocyte, red blood cell, chronic kidney disease, dialysis, iron, neocytolysis, hepcidin, EPO, hemoglobin e

  2. Electrodynamics in Iron and Steel

    E-Print Network [OSTI]

    John Paul Wallace

    2009-06-03T23:59:59.000Z

    In order to calculate the reflected EM fields at low amplitudes in iron and steel, more must be understood about the nature of long wavelength excitations in these metals. A bulk piece of iron is a very complex material with microstructure, a split band structure, magnetic domains and crystallographic textures that affect domain orientation. Probing iron and other bulk ferromagnetic materials with weak reflected and transmitted inductive low frequency fields is an easy operation to perform but the responses are difficult to interpret because of the complexity and variety of the structures affected by the fields. First starting with a simple single coil induction measurement and classical EM calculation to show the error is grossly under estimating the measured response. Extending this experiment to measuring the transmission of the induced fields allows the extraction of three dispersion curves which define these internal fields. One dispersion curve yielded an exceedingly small effective mass of 1.8 10^{-39}kg (1.3 10^{-9} m_e) for those spin waves. There is a second distinct dispersion curve more representative of the density function of a zero momentum bound state rather than a propagating wave. The third dispersion curve describes a magneto-elastic coupling to a very long wave length propagating mode. These experiments taken together display the characteristics of a high temperature Bose-Einstein like condensation that can be initiated by pumping two different states. A weak time dependent field drives the formation of coupled J=0 spin wave pairs with the reduced effective mass reflecting the increased size of the coherent state. These field can dominate induction measurements well past the Curie temperature.

  3. The production of iron carbide

    SciTech Connect (OSTI)

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

    1997-12-31T23:59:59.000Z

    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.

  4. Oceanographic and ecological consequences of iron localization in phytoplankton photosystems

    E-Print Network [OSTI]

    Hopkinson, Brian Matthew

    2007-01-01T23:59:59.000Z

    Y. Zhang, and K.W. Bruland. 1998. An iron limitation mosaicRue, J. Conn, and K.W. Bruland. 2002. Phytoplankton ironY. Zhang, and K.W. Bruland. 1998. An iron limitation mosaic

  5. Iron Cycling and Redox Evolution in the Precambrian

    E-Print Network [OSTI]

    Planavsky, Noah John

    2012-01-01T23:59:59.000Z

    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.

  6. Kinetic theory for dilute cohesive granular gases with a square well potential

    E-Print Network [OSTI]

    Satoshi Takada; Kuniyasu Saitoh; Hisao Hayakawa

    2015-06-15T23:59:59.000Z

    We develop the kinetic theory of dilute cohesive granular gases in which the attractive part is described by a square well potential. We derive the hydrodynamic equations from the kinetic theory with the microscopic expressions for the dissipation rate and the transport coefficients. We check the validity of our theory by performing the direct simulation Monte Carlo.

  7. The Impact of Test Suite Granularity on the CostEffectiveness of Regression Testing

    E-Print Network [OSTI]

    Rothermel, Gregg

    The Impact of Test Suite Granularity on the Cost­Effectiveness of Regression Testing Gregg,pkallakug@cse.unl.edu ABSTRACT Regression testing is an expensive testing process used to validate software following modi#12;cations. The cost-e#11;ective- ness of regression testing techniques varies with characteris- tics of test

  8. The Impact of Test Suite Granularity on the CostEffectiveness of Regression Testing

    E-Print Network [OSTI]

    Rothermel, Gregg

    The Impact of Test Suite Granularity on the Cost­Effectiveness of Regression Testing Gregg,pkallakug@cse.unl.edu ABSTRACT Regression testing is an expensive testing process used to validate software following modifications. The cost­effective­ ness of regression testing techniques varies with characteris­ tics of test

  9. The Impact of Test Suite Granularity on the Cost-Effectiveness of Regression Testing

    E-Print Network [OSTI]

    Rothermel, Gregg

    The Impact of Test Suite Granularity on the Cost-Effectiveness of Regression Testing Gregg,pkallakug@cse.unl.edu ABSTRACT Regression testing is an expensive testing process used to validate software following modi cations. The cost-e ective- ness of regression testing techniques varies with characteris- tics of test

  10. Friction dependence of shallow granular flows from discrete par-ticle simulations

    E-Print Network [OSTI]

    Al Hanbali, Ahmad

    Friction dependence of shallow granular flows from discrete par- ticle simulations Anthony Thornton relation for the macroscopic bed friction or basal roughness obtained from micro-scale discrete particle simulations of steady flows. We systematically vary the bed friction by changing the contact friction

  11. Dense granular ows: two-particle argument accounts for friction-like constitutive law with threshold

    E-Print Network [OSTI]

    Recanati, Catherine

    robust scaling behav- iors in various ow geomerties for dry grains, whether frictional or not [2, 4Dense granular ows: two-particle argument accounts for friction-like constitutive law a constitutive law that exhibits a ow threshold expressed as a #12;nite e#11;ective friction at ow onset

  12. GSTP: A Temporal Reasoning System Supporting Multi-Granularity Temporal Constraints

    E-Print Network [OSTI]

    Mascetti, Sergio

    and algorithms proposed in the literature for Temporal Constraint Satisfaction Problems (TCSP) have essentially granularity, so that some of the standard algorithms for CSP, like consistency checking through arc- or path adopting these conversions as the only tool to reduce the problem to a standard CSP is in- evitably

  13. Ultrasonic wave transport in weakly confined granular media in the intermediate frequency regime

    E-Print Network [OSTI]

    Boyer, Edmond

    Understanding how sound propagates through random non-cohesive granular media [1,2,3,4], such as the sand, has in between nonlinear elastic interactions between grains at the scale of the contacts [5,6], the existence some restrictions, for instance by considering ideal random close packing of monodisperse of elastic

  14. 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

  15. 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.

    1998-12-31T23:59:59.000Z

    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.

  16. ccsd00003870, Importance of convection in the compaction mechanisms of anisotropic granular media

    E-Print Network [OSTI]

    the importance of compression waves propagation on granular compaction. PACS numbers: 45.70.Cc, 45.70.Mg, 83 consists of a glass cylinder of diameter D #25; 10 cm #12;lled with 600 g of grains (corre- sponding frequency f = 30 Hz. The resulting motion of the whole system, monitored by an accelerometer at the bottom

  17. Experimental study of work exchange with a granular gas: the viewpoint of the Fluctuation Theorem.

    E-Print Network [OSTI]

    Boyer, Edmond

    and irreversible thermodynamics PACS 05.40.-a ­ Fluctuation phenomena, random processes, noise, and Brownian motion of the fluctuations of energy flux between a granular gas and a small driven harmonic oscillator. The DC-motor driving forcing, between the motor and the gas are examined from the viewpoint of the Fluctuation Theorem

  18. 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

  19. 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

  20. Finite Element Modeling of Rate-Dependent Ratcheting in Granular Materials

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Finite Element Modeling of Rate-Dependent Ratcheting in Granular Materials A. Karrech a,, A. Seibi thrust is the introduc- tion of the "Chicago" law in a continuum approach to account for the ratcheting or jointly with the ratcheting effect. Non-associated plasticity is adopted since the paper mainly targets

  1. Granular flow in the marginal ice zone BY DANIEL L. FELTHAM

    E-Print Network [OSTI]

    Feltham, Daniel

    and the balance equation of fluctuation kinetic energy. The steady solution of these equations is found to leading in determining the dynamics of the MIZ. Here, sea ice is treated as a granular material with a composite rheology. A simplified model of the MIZ is introduced consisting of the along and across momentum balance of the sea ice

  2. A new constitutive law for dense granular flows Pierre Jop1

    E-Print Network [OSTI]

    , constitutive equations for dry granular flows are still matter of debates1-10 . One difficulty is that grains number: = µ(I)P with I = d P /s (1) where µ(I ) is the friction coefficient, d is the particle of the Savage number20 or of the Coulomb number21 introduced previously in the literature, can be interpreted

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

    E-Print Network [OSTI]

    -less granular media. Compressibil- ity, dilatancy and Coulomb-like friction are the three basic ingredients Abstract We propose a simple continuum model to interpret the shearing motion of dense, dry and cohesion slow motions with predominance of friction, less dense ones are usually found in vigorous motions

  4. Plane and oblique shocks in shallow granular flows J.M.N.T. Gray1

    E-Print Network [OSTI]

    Gray, Nico

    force is the difference between the gravitational acceleration and the Coulomb rate-independent dry angle of friction in the Mohr- Coulomb constitutive relation. The transition be- tween the two states of an incompress- ible Mohr-Coulomb granular material sliding down a rigid surface. Using a slope fitted

  5. 2006 Nature Publishing Group A constitutive law for dense granular flows

    E-Print Network [OSTI]

    Pouliquen, Olivier

    equations for dry granular flows, which govern how the material moves under shear, are still a matter(I) is the friction coefficient, d is the particle diameter and ms is the particle density. They found that the volume number, which is the square root of the Savage number20 or of the Coulomb number21 introduced previously

  6. A new constitutive law for dense granular flows Pierre Jop1

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    , constitutive equations for dry granular flows are still matter of debates1-10 . One difficulty is that grains number: = µ(I)P with I = d P /s (1) where µ(I ) is the friction coefficient, d is the particle diameter or of the Coulomb number21 introduced previously in the literature, can be interpreted as the ratio between two time

  7. Study of Gas Flow Dynamics in Porous and Granular Media with Laser-Polarized 129

    E-Print Network [OSTI]

    Walsworth, Ronald L.

    Abstract This thesis presents Nuclear Magnetic Resonance (NMR) studies of gas flow dynamics in porous in porous rock cores and the mass exchanges between different phases in fluidized granular systems, were-emulsion exchange and emulsion-adsorption exchange in a fluidized bed are two processes crucial to the efficiency

  8. Granular Matter (2007) 9:331335 DOI 10.1007/s10035-007-0045-3

    E-Print Network [OSTI]

    Walsworth, Ronald L.

    2007-01-01T23:59:59.000Z

    magnetic resonance (NMR) experim- ents are described for gas-fluidized granular beds, which are important · Fluidized bed · NMR · Hyperpolarized gas 1 Introduction Nuclear magnetic resonance (NMR) enables noninvasive systems for many materials-processing operations. Using pulsed field gradient, magnetic resonance imaging

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

    E-Print Network [OSTI]

    between observed and estimated values). These methods allow non-intrusive and fully automated measurements granular material. The principal objective here is to provide simple optical techniques for the non-intrusive to images of particles with a significant apparent void fraction (i.e., non-touching particles). [5

  10. Granular temperature as an energy dissipation mechanism in bodies of the Solar System

    E-Print Network [OSTI]

    Daly, Samantha

    Granular temperature as an energy dissipation mechanism in bodies of the Solar System BY JON KADISH Mary College, University of London, Mile End Road, London E1 4NS, UK There is theoretical grains to boulders. It is well known that energy added to such systems is dissipated by friction

  11. On pore-fluid viscosity and the wave properties of saturated granular materials including marine sediments

    E-Print Network [OSTI]

    Buckingham, Michael

    interactions. Designated the VGS theory, the new model returns dispersion curves that differ mildly from those sediments Michael J. Buckinghama Marine Physical Laboratory, Scripps Institution of Oceanography, University granular material, such as a marine sediment, is extended to include the effects of the viscosity

  12. The iron reduction ability of various rose rootstocks

    E-Print Network [OSTI]

    McDonald, Garry Vernon

    1990-01-01T23:59:59.000Z

    and day 14. . . . . . . . 3. Summation of peak iron reduction rates in the rose genotypes at day 7, and FeEDTA concentration of peak reduction. . . . . . . . . . . . . . . Page . . . . 30 . . . . 36 . . . . 38 CHAPTER I INTRODUCTION Iron nutrition..., usually as oxides. The amount of iron that is soluble in a soil is quite low compared to the total iron content, being dependent on the solubility of inorganic iron oxides. Soluble forms of inorganic iron include Fe +, Fe(OH) +, Fe(OH)g+ and Fe...

  13. Dechlorination of TCE with palladized iron

    DOE Patents [OSTI]

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

    1997-01-01T23:59:59.000Z

    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.

  14. Production of iron from metallurgical waste

    DOE Patents [OSTI]

    Hendrickson, David W; Iwasaki, Iwao

    2013-09-17T23:59:59.000Z

    A method of recovering metallic iron from iron-bearing metallurgical waste in steelmaking comprising steps of providing an iron-bearing metallurgical waste containing more than 55% by weight FeO and FeO equivalent and a particle size of at least 80% less than 10 mesh, mixing the iron-bearing metallurgical waste with a carbonaceous material to form a reducible mixture where the carbonaceous material is between 80 and 110% of the stoichiometric amount needed to reduce the iron-bearing waste to metallic iron, and as needed additions to provide a silica content between 0.8 and 8% by weight and a ratio of CaO/SiO.sub.2 between 1.4 and 1.8, forming agglomerates of the reducible mixture over a hearth material layer to protect the hearth, heating the agglomerates to a higher temperature above the melting point of iron to form nodules of metallic iron and slag material from the agglomerates by melting.

  15. Helium Migration in Iron Christ's College

    E-Print Network [OSTI]

    Cambridge, University of

    Helium Migration in Iron Y. Zhang Christ's College Department of Materials Science and Metallurgy the achievement at all. ii #12;Abstract A theoretical model of helium migration in body centred cubic (BCC)structure irons has been developed using the concept of the effective helium diffusion coeffi- cient

  16. Introduction Southern Ocean natural iron fertilization

    E-Print Network [OSTI]

    led to immediate localized phytoplankton blooms. They also have stimulated con- siderable speculation processes motivated three field programs in 2004­ 2006. The United Kingdom led the "CROZet natural iron into surface waters, recycling of nutrients, reactivity of iron, and phytoplankton physiology. This special

  17. Climate VISION: Private Sector Initiatives: Iron and Steel: Resources...

    Office of Scientific and Technical Information (OSTI)

    Industry Associations American Iron and Steel Institute For over a century, North American steel producers have worked as partners and members of the American Iron and Steel...

  18. 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)

    1986-09-16T23:59:59.000Z

    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.

  19. Morphology and Oxide Shell Structure of Iron Nanoparticles Grown...

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

    Oxide Shell Structure of Iron Nanoparticles Grown by Sputter-Gas-Aggregation. Morphology and Oxide Shell Structure of Iron Nanoparticles Grown by Sputter-Gas-Aggregation. Abstract:...

  20. Production and Early Preservation of Lipid Biomarkers in Iron...

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

    Production and Early Preservation of Lipid Biomarkers in Iron Hot Springs. Production and Early Preservation of Lipid Biomarkers in Iron Hot Springs. Abstract: The...

  1. Bioreduction of hematite nanoparticles by the dissimilatory iron...

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

    nanoparticles by the dissimilatory iron reducing bacterium Shewanella oneidensis MR-1. Bioreduction of hematite nanoparticles by the dissimilatory iron reducing bacterium...

  2. Electrochemical Studies of Packed Iron Powder Electrodes: Effects...

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

    of Packed Iron Powder Electrodes: Effects of Common Constituents of Natural Waters on Corrosion Electrochemical Studies of Packed Iron Powder Electrodes: Effects of Common...

  3. Microbial Reduction of Uranium under Iron- and Sulfate-reducing...

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

    Uranium under Iron- and Sulfate-reducing Conditions: Effect of Amended Goethite on Microbial Community Microbial Reduction of Uranium under Iron- and Sulfate-reducing Conditions:...

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

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

    Iron and Steel (NAICS 3311, 3312), October 2012 (MECS 2006) Manufacturing Energy and Carbon Footprint - Sector: Iron and Steel (NAICS 3311, 3312), October 2012 (MECS 2006)...

  5. Watermelon-like iron nanoparticles: Cr doping effect on magnetism...

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

    Watermelon-like iron nanoparticles: Cr doping effect on magnetism and magnetization interaction reversal. Watermelon-like iron nanoparticles: Cr doping effect on magnetism and...

  6. 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,...

  7. Iron Cycling and Redox Evolution in the Precambrian

    E-Print Network [OSTI]

    Planavsky, Noah John

    2012-01-01T23:59:59.000Z

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

  8. EPA/ITRC-RTDF permeable reactive barrier short course. Permeable reactive barriers: Application and deployment

    SciTech Connect (OSTI)

    Not Available

    1999-01-01T23:59:59.000Z

    This report focuses on the following: Permeable Reactive Barriers: Application and Deployment; Introduction to Permeable Reactive Barriers (PRBs) for Remediating and Managing Contaminated Groundwater in Situ; Collection and Interpretation of Design Data 1: Site Characterization for PRBs; Reactive Materials: Zero-Valent Iron; Collection and Interpretation of Design Data 2: Laboratory and Pilot Scale Tests; Design Calculations; Compliance Monitoring, Performance Monitoring and Long-Term Maintenance for PRBs; PRB Emplacement Techniques; PRB Permitting and Implementation; Treatment of Metals; Non-Metallic Reactive Materials; Economic Considerations for PRB Deployment; and Bibliography.

  9. EPA/ITRC-RTDF permeable reactive barrier short course. Permeable reactive barriers: Application and deployment

    SciTech Connect (OSTI)

    NONE

    1999-11-01T23:59:59.000Z

    This report focuses on the following: Permeable Reactive Barriers: Application and Deployment; Introduction to Permeable Reactive Barriers (PRBs) for Remediating and Managing Contaminated Groundwater in Situ; Collection and Interpretation of Design Data 1: Site Characterization for PRBs; Reactive Materials: Zero-Valent Iron; Collection and Interpretation of Design Data 2: Laboratory and Pilot Scale Tests; Design Calculations; Compliance Monitoring, Performance Monitoring and Long-Term Maintenance for PRBs; PRB Emplacement Techniques; PRB Permitting and Implementation; Treatment of Metals; Non-Metallic Reactive Materials; Economic Considerations for PRB Deployment; and Bibliography.

  10. 2iron-based superconductors

    SciTech Connect (OSTI)

    Bossoni, L [University of Pavia-CNISM; Romano, L [University of Parma, Parco Area dell Scienze; Canfield, Paul C [Ames Laboratory; Lascialfari, A [Universita degli Studi di Milano

    2014-10-08T23:59:59.000Z

    We measured the static uniform spin susceptibility of Ba(Fe1?xRhx)2As2 iron-based superconductors, over a broad range of doping (0.041x0.094) and magnetic fields. At small fields (H1kOe) we observed, above the transition temperature Tc, the occurrence of precursor diamagnetism, which is not ascribable to the Ginzburg–Landau theory. On the contrary, our data agree with a phase fluctuation model, which has been used to interpret a similar phenomenology occurring in the high- Tc cuprate superconductors. Additionally, in the presence of strong fields, the unconventional fluctuating diamagnetism is suppressed, whereas Ginzburg–Landau fluctuations are found, in agreement with literature.

  11. Dechlorination of TCE with palladized iron

    DOE Patents [OSTI]

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

    1997-03-18T23:59:59.000Z

    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.

  12. Dechlorination of TCE with palladized iron

    DOE Patents [OSTI]

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

    1998-06-02T23:59:59.000Z

    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.

  13. Evidence for Localization of Reaction Upon Reduction of Carbon...

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

    Localization of Reaction Upon Reduction of Carbon Tetrachloride by Granular Iron. Evidence for Localization of Reaction Upon Reduction of Carbon Tetrachloride by Granular Iron....

  14. Influence of fine particles on the stability of a humid granular pile

    E-Print Network [OSTI]

    Xixi Huang; Sandrine Bec; J. Colombani

    2014-12-02T23:59:59.000Z

    We have investigated by rotating drum experiments the influence of a small amount of fine particles on the stability of a granular heap. The fine particles are shown to have a strong and ambivalent influence. For low fine particle content, the heap destabilizes by avalanches, and the fine particles tend to fluidize the heap. In contrast, for high fine particle content, they increase the cohesion of the heap, which destabilizes through stick-slip at the drum wall. We interpret and model the fluidification in the avalanching regime, which we show is independent of humidity, by granular lubrication considerations, whereas the stick-slip behavior, highly dependent on humidity, is understood by a solid friction model.

  15. Memory of the Unjamming Transition during Cyclic Tiltings of a Granular Pile

    E-Print Network [OSTI]

    Stephanie Deboeuf; Olivier Dauchot; Lydie Staron; Anne Mangeney; Jean-Pierre Vilotte

    2005-09-23T23:59:59.000Z

    Discrete numerical simulations are performed to study the evolution of the micro-structure and the response of a granular packing during successive loading-unloading cycles, consisting of quasi-static rotations in the gravity field between opposite inclination angles. We show that internal variables, e.g., stress and fabric of the pile, exhibit hysteresis during these cycles due to the exploration of different metastable configurations. Interestingly, the hysteretic behaviour of the pile strongly depends on the maximal inclination of the cycles, giving evidence of the irreversible modifications of the pile state occurring close to the unjamming transition. More specifically, we show that for cycles with maximal inclination larger than the repose angle, the weak contact network carries the memory of the unjamming transition. These results demonstrate the relevance of a two-phases description -strong and weak contact networks- for a granular system, as soon as it has approached the unjamming transition.

  16. Influence of fine particles on the stability of a humid granular pile

    E-Print Network [OSTI]

    Huang, Xixi; Colombani, J

    2014-01-01T23:59:59.000Z

    We have investigated by rotating drum experiments the influence of a small amount of fine particles on the stability of a granular heap. The fine particles are shown to have a strong and ambivalent influence. For low fine particle content, the heap destabilizes by avalanches, and the fine particles tend to fluidize the heap. In contrast, for high fine particle content, they increase the cohesion of the heap, which destabilizes through stick-slip at the drum wall. We interpret and model the fluidification in the avalanching regime, which we show is independent of humidity, by granular lubrication considerations, whereas the stick-slip behavior, highly dependent on humidity, is understood by a solid friction model.

  17. MC-DEM: a novel simulation scheme for modeling dense granular media

    E-Print Network [OSTI]

    Nicolas Brodu; Joshua A. Dijksman; Robert P. Behringer

    2014-10-23T23:59:59.000Z

    This article presents a new force model for performing quantitative simulations of dense granular materials. Interactions between multiple contacts (MC) on the same grain are explicitly taken into account. Our readily applicable method retains all the advantages of discrete element method (DEM) simulations and does not require the use of costly finite element methods. The new model closely reproduces our recent experimental measurements, including contact force distributions in full 3D, at all compression levels up to the experimental maximum limit of 13\\%. Comparisons with traditional non-deformable spheres approach are provided, as well as with alternative models for interactions between multiple contacts. The success of our model compared to these alternatives demonstrates that interactions between multiple contacts on each grain must be included for dense granular packings.

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

    SciTech Connect (OSTI)

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

    2009-01-15T23:59:59.000Z

    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.

  19. Stratification, segregation and mixing of granular materials in quasi-2D bounded heaps

    E-Print Network [OSTI]

    Yi Fan; Youcef Boukerkour; Thibault Blanc; Paul B. Umbanhowar; Julio M. Ottino; Richard M. Lueptow

    2012-09-25T23:59:59.000Z

    Segregation and mixing of granular mixtures during heap formation have important consequences in industry and agriculture. This research investigates three different final particle configurations of bi-disperse granular mixtures -- stratified, segregated and mixed -- during filling of quasi-two dimensional silos. We consider a larger number and relatively wider range of control parameters than previous studies, including particle size ratio, flow rate, system size and heap rise velocity. The boundary between stratified and unstratified states is primarily controlled by the two-dimensional flow rate, with the critical flow rate for the transition depending weakly on particle size ratio and flowing layer length. In contrast, the transition from segregated to mixed states is controlled by the rise velocity of the heap, a control parameter not previously considered. The critical rise velocity for the transition depends strongly on the particle size ratio.

  20. Modeling energy dissipation induced by quasi-static compaction of granular HMX

    SciTech Connect (OSTI)

    Gonthier, K.A.; Menikoff, R.; Son, S.F.; Asay, B.W. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    1998-07-01T23:59:59.000Z

    A simple extension of a conventional two-phase continuum model of Deflagration-to-Detonation Transition (DDT) in energetic granular material is given to account for energy dissipation induced by quasi-static compaction. To this end, the conventional model equations are supplemented by a relaxation equation that accounts for irreversible changes in solid volume fraction due to intergranular friction, plastic deformation of granules, and granule fracture. The proposed model, which is consistent with the Second Law of Thermodynamics for a two-phase mixture, is demonstrated by applying it to the quasi-static compaction of granular HMX. The model predicts results commensurate with experimental data including stress relaxation and substantial dissipation; such phenomena have not been previously accounted for by two-phase DDT models. {copyright} {ital 1998 American Institute of Physics.}

  1. Scaling and dynamics of sphere and disk impact into granular media

    E-Print Network [OSTI]

    Daniel I Goldman; Paul B. Umbanhowar

    2007-09-25T23:59:59.000Z

    Direct measurements of the acceleration of spheres and disks impacting granular media reveal simple power law scalings along with complex dynamics which bear the signatures of both fluid and solid behavior. The penetration depth scales linearly with impact velocity while the collision duration is constant for sufficiently large impact velocity. Both quantities exhibit power law dependence on sphere diameter and density, and gravitational acceleration. The acceleration during impact is characterized by two jumps: a rapid, velocity dependent increase upon initial contact and a similarly sharp, depth dependent decrease as the impacting object comes to rest. Examining the measured forces on the sphere in the vicinity of these features leads to a new experimentally based granular force model for collision. We discuss our findings in the context of recently proposed phenomenological models that capture qualitative dynamical features of impact but fail both quantitatively and in their inability to capture significant acceleration fluctuations that occur during penetration and which depend on the impacted material.

  2. MOSSBAUER STUDIES ON THE STATE OF TIN ATOMS SEGREGATED AT THE GRAIN BOUNDARY OF IRON AND IRON ALLOYS

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    MOSSBAUER STUDIES ON THE STATE OF TIN ATOMS SEGREGATED AT THE GRAIN BOUNDARY OF IRON AND IRON iron and iron alloys is investigated by Mossbauer source experiments. It is found that the electronic. The Mossbauer effect should be potentially a powerful technique to investigate the binding state of individual

  3. Thermal transport properties of grey cast irons

    SciTech Connect (OSTI)

    Hecht, R.L. [Ford Motor Co., Dearborn, MI (United States). Ford Research Lab.; Dinwiddie, R.B.; Porter, W.D.; Wang, Hsin [Oak Ridge National Lab., TN (United States)

    1996-10-01T23:59:59.000Z

    Thermal diffusivity and thermal conductivity of grey cast iron have been measured as a function of graphite flake morphology, chemical composition, and position in a finished brake rotor. Cast iron samples used for this investigation were cut from ``step block`` castings designed to produce iron with different graphite flake morphologies resulting from different cooling rates. Samples were also machined from prototype alloys and from production brake rotors representing a variation in foundry practice. Thermal diffusivity was measured at room and elevated temperatures via the flash technique. Heat capacity of selected samples was measured with differential scanning calorimetry, and these results were used to calculate the thermal conductivity. Microstructure of the various cast iron samples was quantified by standard metallography and image analysis, and the chemical compositions were determined by optical emission spectroscopy.

  4. System and method for producing metallic iron

    DOE Patents [OSTI]

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

    2014-07-29T23:59:59.000Z

    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.

  5. Iron and the ecology of marine microbes

    E-Print Network [OSTI]

    Ventouras, Laure-Anne

    2013-01-01T23:59:59.000Z

    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 ...

  6. Simulation Study of Internal and Surface waves of Vertically Vibrated Granular Materials

    E-Print Network [OSTI]

    Kai Huang; Guoqing Miao; Peng Zhang; Yifei Zhu; Rongjue Wei

    2005-11-29T23:59:59.000Z

    Molecular dynamical (MD) simulations are performed to simulate two dimensional vibrofluidized granular materials in this work. Statistics on simulation results indicate that there exist shocks propagating upward in each vibrating cycle. Under certain driving parameters surface waves similar to Faraday instability in normal fluid coexist with internal waves. Relationship between the two kinds of waves is explored. Moreover simulation results indicate that periodically structured bottom can change the dispersion relationship and amplitude of surface waves.

  7. Depth-Independent Drag Force Induced by Stirring in Granular Media Francois Guillard,* Yoel Forterre,

    E-Print Network [OSTI]

    Boyer, Edmond

    may be used to drill deeply in a granular medium without developing high torques. DOI: 10.1103/PhysRevLett.110.138303 PACS numbers: 47.57.Gc, 45.20.da, 45.70.Ã?n In fluid mechanics, the problem of the forces experi- enced by an object moving in a fluid has been extensively studied. Whereas most investigations

  8. The impact of non-LTE effects and granulation inhomogeneities on the derived iron and oxygen abundances in metal-poor halo stars

    E-Print Network [OSTI]

    Nataliya Shchukina; Javier Trujillo Bueno; Martin Asplund

    2004-10-20T23:59:59.000Z

    This paper presents the results of a detailed theoretical investigation of the impact of non-LTE effects and of granulation inhomogeneities on the derived iron and oxygen abundances in the metal-poor halo subgiant HD140283. Our analysis is based on both the `classical' one-dimensional (1D) stellar atmosphere models and on the new generation of three-dimensional (3D) hydrodynamical models. We find that the non-LTE effects on the iron abundance derived from Fe {\\sc i} lines are very important, amounting to ${\\sim}0.9$ dex and to ${\\sim}0.6$ dex in the 3D and 1D cases, respectively. On the other hand, we find that non-LTE and 3D effects have to be taken into account for a reliable determination of the iron abundance from weak Fe {\\sc ii} lines, because the significant overexcitation of their upper levels in the granular regions tend to produce emission features. As a result such Fe {\\sc ii} lines are weaker than in LTE and the abundance correction amounts to ${\\sim}0.4$ dex for the 3D case. We derive also the oxygen-to-iron abundance ratio in the metal-poor star HD140283 by using the O {\\sc i} triplet at 7772--5 \\AA and the forbidden [O {\\sc i}] line at 6300 \\AA. Interestingly, when both non-LTE and 3D effects are taken into account there still remains significant discrepancies in the iron abundances derived from Fe {\\sc i} and Fe {\\sc ii} lines, as well as in the oxygen abundances inferred from the O {\\sc i} and [O {\\sc i}] lines. We conclude that the metalicity of this type of metal-poor stars could be significantly larger than previously thought, which may have far-reaching implications in stellar astrophysics.

  9. Dechlorination of TCE with palladized iron

    DOE Patents [OSTI]

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

    1997-04-01T23:59:59.000Z

    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.

  10. Realization and Tests of the Highly Granular CALICE Engineering Calorimeter Prototypes, 15th International Conference on Calorimetry in High Energy Physics

    E-Print Network [OSTI]

    The CALICE Collaboration

    2015-01-01T23:59:59.000Z

    Realization and Tests of the Highly Granular CALICE Engineering Calorimeter Prototypes, 15th International Conference on Calorimetry in High Energy Physics

  11. 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.

    1991-10-17T23:59:59.000Z

    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.

  12. 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.

    1995-08-01T23:59:59.000Z

    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.

  13. 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

    2015-02-04T23:59:59.000Z

    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.

  14. 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

    2014-09-12T23:59:59.000Z

    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.

  15. Discrete modelling of capillary mechanisms in multi-phase granular media

    E-Print Network [OSTI]

    L. Scholtès; B. Chareyre F. Nicot; F. Darve

    2012-03-06T23:59:59.000Z

    A numerical study of multi-phase granular materials based upon micro-mechanical modelling is proposed. Discrete element simulations are used to investigate capillary induced effects on the friction properties of a granular assembly in the pendular regime. Capillary forces are described at the local scale through the Young-Laplace equation and are superimposed to the standard dry particle interaction usually well simulated through an elastic-plastic relationship. Both effects of the pressure difference between liquid and gas phases and of the surface tension at the interface are integrated into the interaction model. Hydraulic hysteresis is accounted for based on the possible mechanism of formation and breakage of capillary menisci at contacts. In order to upscale the interparticular model, triaxial loading paths are simulated on a granular assembly and the results interpreted through the Mohr-Coulomb criterion. The micro-mechanical approach is validated with a capillary cohesion induced at the macroscopic scale. It is shown that interparticular menisci contribute to the soil resistance by increasing normal forces at contacts. In addition, more than the capillary pressure level or the degree of saturation, our findings highlight the importance of the density number of liquid bonds on the overall behaviour of the material.

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

    SciTech Connect (OSTI)

    Tunnah, B.G.

    1981-01-01T23:59:59.000Z

    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)

  17. Effect of different intravenous iron preparations on lymphocyte intracellular reactive oxygen species generation and subpopulation survival.

    E-Print Network [OSTI]

    Gupta, Ajay; Zhuo, Jiaying; Zha, Junli; Reddy, Srinivasa; Olp, Jonathan; Pai, Amy

    2010-01-01T23:59:59.000Z

    IV iron compounds induced greater intracellular ROS generation,IV iron preparations on intracellular reactive oxygen species generationIV iron preparations on intracellular immune cell ROS generation

  18. 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

    2007-01-01T23:59:59.000Z

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

  19. Iron speciation in urban dust

    SciTech Connect (OSTI)

    Elzinga, E.J.; Fitts, J.; Gao, Y.; Tappero, R.

    2011-08-01T23:59:59.000Z

    An improved understanding of anthropogenic impacts on ocean fertility requires knowledge of anthropogenic dust mineralogy and associated Fe speciation as a critical step toward developing Fe solubility models constrained by mineralogical composition. This study explored the utility of micro-focused X-ray absorption spectroscopy ({mu}-XAS) in characterizing the speciation of Fe in urban dust samples. A micro-focused beam of 10 x 7 {mu}m made possible the measurement of the Fe K edge XAS spectra of individual dust particles in the PM5.6 size fraction collected in Newark, New Jersey, USA. Spectral analysis indicated the presence of mixtures of Fe-containing minerals within individual dust particles; we observed significant magnetite content along with other Fe(III)-(hydr)oxide minerals which could not be conclusively identified. Our data indicate that detailed quantitative determination of Fe speciation requires extended energy scans to constrain the types and relative abundance of Fe species present. We observe heterogeneity in Fe speciation at the dust particle level, which underscores the importance of analyzing a statistically adequate number of particles within each dust sample. Where possible, {mu}-XAS measurements should be complemented with additional characterization techniques such as {mu}-XRD and bulk XAS to obtain a comprehensive picture of the Fe speciation in dust materials. X-ray microprobes should be used to complement bulk methods used to determine particle composition, methods that fail to record particle heterogeneity. Keywords - Urban dust; Iron; Speciation; Micro-focused X-ray absorption spectroscopy.

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

    SciTech Connect (OSTI)

    Shen, M.; Yang, R.T.

    1980-09-30T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    2009-10-15T23:59:59.000Z

    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.

  2. Moving granular-bed filter development program, Option III: Development of moving granular-bed filter technology for multi-contaminant control. Task 14: Test plan; Topical report

    SciTech Connect (OSTI)

    Haas, J.C.; Olivo, C.A.; Wilson, K.B.

    1994-04-01T23:59:59.000Z

    An experimental test plan has been prepared for DOE/METC review and approval to develop a filter media suitable for multi-contaminant control in granular-bed filter (GBF) applications. The plan includes identification, development, and demonstration of methods for enhanced media morphology, chemical reactivity, and mechanical strength. The test plan includes media preparation methods, physical and chemical characterization methods for fresh and reacted media, media evaluation criteria, details of test and analytical equipment, and test matrix of the proposed media testing. A filter media composed of agglomerated limestone and clay was determined to be the best candidate for multi-contaminate control in GBF operation. The combined limestone/clay agglomerate has the potential to remove sulfur and alkali species, in addition to particulate, and possibly halogens and trace heavy metals from coal process streams.

  3. Diatomaceous earth and activated bauxite used as granular sorbents for the removal of sodium chloride vapor from hot flue gas

    SciTech Connect (OSTI)

    Lee, S.H.D.; Swift, W.M.; Johnson, I.

    1980-01-01T23:59:59.000Z

    Diatomaceous earth and activated bauxite were tested as granular sorbents for use as filter media in granular-bed filters for the removal of gaseous alkali metal compounds from the hot (800/sup 0/C) flue gas of PFBC. Tests were performed at atmospheric pressure, using NaCl vapor transported in relatively dry simulated flue gas of PFBC. Either a fixed-bed combustor or a high-temperature sorption test rig was used. The effects of sorbent bed temperature, superficial gas velocity, gas hourly space velocity, and NaCl-vapor concentration in flue gas on the sorption behavior of these two sorbents and their ultimate sorption capacities were determined. Both diatomaceous earth and activated bauxite were found to be very effective in removing NaCl vapor from flue gas. Preliminary cost evaluations showed that they are economically attractive as granular sorbents for cleaning alkali vapor from simulated flue gas.

  4. Iron and Manganese in Potable Water

    E-Print Network [OSTI]

    Young, Clifford Caudy

    1911-06-01T23:59:59.000Z

    none 22. Hays 469.0 1.0 none 23. Hays .55 24. Peabody 830.0 .5 trace 25. Caldwell 458.0 2.0 trace 26. Lyons 456.0 .1 trace 27. Osborne 377.0 .3 none 28. Herington 608,0 .1 trace 29. Sterling - - _ .1 .036 30. Waverly 546,0 .2 none 31. Clifton 350.... The occurence of a black peaty layer overlying white sand containing iron, the white sand in turn overlying red sand containing 10. oxidize^ iron, is a familiar sight to all engineers who have made excavations. Here the carbon dioxide produced...

  5. Steam reforming utilizing iron oxide catalyst

    SciTech Connect (OSTI)

    Setzer, H. T.; Bett, J. A. S.

    1985-06-11T23:59:59.000Z

    High activity steam reforming iron oxide catalysts are described. Such catalysts can be unsupported utilizing at least 90% by weight iron oxide and various modifiers (Ai/sub 2/O/sub 3/, K/sub 2/O, CaO, SiO/sub 2/) or unmodified and supported on such things as alumina, CaO impregnated alumina, and lanthanum stabilized alumina. When used in steam reformers such as autothermal and tubular steam reformers, these catalysts demonstrate much improved resistance to carbon plugging.

  6. 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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12 Investigation Peer Review 2012IowaFebruaryIronIron

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

    DOE Patents [OSTI]

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

    1985-10-28T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Paramore, James D

    2010-01-01T23:59:59.000Z

    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 ...

  9. Iron-based Superconductor Simulations Spin Out New Possibilities...

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

    in 15 iron-based materials, including iron compounds that are high-temperature superconductors (images d-h). The x axis shows the momentum of the spin excitation in selected...

  10. The marine biogeochemistry of dissolved and colloidal iron

    E-Print Network [OSTI]

    Fitzsimmons, Jessica Nicole

    2013-01-01T23:59:59.000Z

    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 ...

  11. arabian iron age: Topics by E-print Network

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

    iron deficiency should be the goal of nutritional intervention programs. In the United States, approximately 5 % of children from 1-5 years of age suffer from iron deficiency...

  12. 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.

    2002-09-18T23:59:59.000Z

    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.

  13. 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)

    1993-01-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

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

    2014-01-01T23:59:59.000Z

    A detailed study of hadronic interactions is presented using data recorded with the highly granular CALICE silicon-tungsten electromagnetic calorimeter. Approximately 600,000 selected negatively changed 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. Although a reasonable overall description of the data is observed, there are significant quantitative discrepancies in the longitudinal and transverse distributions of reconstructed energy.

  15. 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

    2014-11-26T23:59:59.000Z

    A detailed study of hadronic interactions is presented using data recorded with the highly granular CALICE silicon-tungsten electromagnetic calorimeter. Approximately 600,000 selected negatively changed 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. Although a reasonable overall description of the data is observed, there are significant quantitative discrepancies in the longitudinal and transverse distributions of reconstructed energy.

  16. Lithium Iron Phosphate Composites for Lithium Batteries | Argonne...

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

    Lithium Iron Phosphate Composites for Lithium Batteries Technology available for licensing: Inexpensive, electrochemically active phosphate compounds with high functionality for...

  17. 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.

  18. Versatile ferrofluids based on polyethylene glycol coated iron oxide nanoparticles

    E-Print Network [OSTI]

    Versatile ferrofluids based on polyethylene glycol coated iron oxide nanoparticles W. Brullot a coated iron oxide nanoparticles were obtained by a facile protocol and thoroughly characterized to chemical treatments and biocompatible [12]. An impression of an iron oxide nanoparticle coated with a PEG

  19. The Adsorption of Arsenic Oxyacids to Iron Oxyhydroxide Columns

    E-Print Network [OSTI]

    The Adsorption of Arsenic Oxyacids to Iron Oxyhydroxide Columns Including Studies of Weakly. (photo: Mr. J. Mähler, image editing Dr. D. Lundberg) #12;The Adsorption of Arsenic Oxyacids to Iron of columns and iron content of the adsorbent material. Experiments have shown that adsorption does occur

  20. 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

    2007-01-01T23:59:59.000Z

    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 ...

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

    E-Print Network [OSTI]

    King, Andrew Luke

    2008-01-01T23:59:59.000Z

    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

  2. Drinking Water Problems: Iron and Manganese

    E-Print Network [OSTI]

    Dozier, Monty; McFarland, Mark L.

    2004-02-20T23:59:59.000Z

    . The chemical must be in the water for at least 20 minutes for oxi- dation to take place, longer if the water contains colloidal iron/manganese. After solid particles have formed they are filtered, often with a sand filter. Adding aluminum sulfate (alum...

  3. Iron Air collision with high density QCD

    E-Print Network [OSTI]

    Hans-Joachim Drescher

    2006-12-08T23:59:59.000Z

    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.

  4. 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

  5. Ligand effects on bioinspired iron complexes

    E-Print Network [OSTI]

    Mejia Rodriguez, Ma. del Rosario

    2005-11-01T23:59:59.000Z

    - phosphaadamantane, PTA, coordinates to the Fe centers forming the disubstituted complex (m-pdt)[Fe(CO)2PTA]2, which presents one PTA in each iron in a transoid arrangement. Substitution of one CO ligand in the (m-pdt)[Fe(CO)3]2 parent complex forms the asymmetric (m-pdt)[Fe...

  6. Diverging viscosity and soft granular rheology in non-Brownian suspensions

    E-Print Network [OSTI]

    Takeshi Kawasaki; Daniele Coslovich; Atsushi Ikeda; Ludovic Berthier

    2015-04-03T23:59:59.000Z

    We use large scale computer simulations and finite size scaling analysis to study the shear rheology of dense three-dimensional suspensions of frictionless non-Brownian particles in the vicinity of the jamming transition. We perform simulations of soft repulsive particles at constant shear rate, constant pressure, and finite system size, and study carefully the asymptotic limits of large system sizes and infinitely hard particle repulsion. Extending earlier analysis by about two orders of magnitude, we first study the asymptotic behavior of the shear viscosity in the hard particle limit. We confirm its asymptotic power law divergence at the jamming transition, but show that a precise determination of the critical density and critical exponent is difficult due to the `multiscaling' behavior of the viscosity. Additionally, finite-size scaling analysis suggests that this divergence is accompanied by a growing correlation length scale, which also diverges algebraically. We then study the effect of soft repulsion, and propose a natural extension of the standard granular rheology to account for softness effects, which we validate from simulations. Close to the jamming transition, this `soft granular rheology' offers a detailed description of the non-linear rheology of soft particles, which differs from earlier empirical scaling forms.

  7. 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

    2014-08-17T23:59:59.000Z

    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 groups 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 both laboratory experiments and 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.

  8. 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

    2015-04-23T23:59:59.000Z

    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.

  9. 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

    2006-02-16T23:59:59.000Z

    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.

  10. MRI Investigations of Particle Motion within a Three-Dimensional Vibro-Fluidized Granular Bed

    E-Print Network [OSTI]

    Mick D. Mantle; Andrew J. Sederman; Lynn F. Gladden; Jonathan M. Huntley; Tom W. Martin Ricky D. Wildman; Mark D. Shattuck

    2007-02-08T23:59:59.000Z

    The unique ability of magnetic resonance imaging (MRI) to provide spatial and temporal information from optically opaque systems, in three dimensions, make it an ideal tool to study the internal motion of rapid granular flows. This paper will focus on the use of ultra-fast velocity compensated MRI measurements to study particle velocity and density distributions in a granular gas, produced by vibrating vertically a bed of mustard seeds at 40 Hz. Specifically, a velocity compensated, double spin-echo, triggered, one-dimensional MRI profiling pulse sequence was developed. This gives an MRI temporal resolution of approximately 2 ms and also minimises MRI velocity artefacts. 12 phase measurements per vibration cycle were used. The data can be used to extract values of the mustard seed average velocity and velocity propagators (probability distributions functions) as a function of the phase of the vibration cycle and vertical height within the cell. The data show strong transient effects during the impact phase of the vibration. A detailed discussion of the temporal passage of the individual phase resolved, height resolved velocity distributions, along with seed velocity propagators at a fix height from the vibrating base is presented.

  11. Visualizing Iron Deposition in Multiple Sclerosis Cadaver Brains

    SciTech Connect (OSTI)

    Habib, Charbel A.; Zheng Weili; Mark Haacke, E. [Department Of Biomedical Engineering, Wayne State University, Detroit, MI 48202 (United States); Webb, Sam [Stanford Synchrotron Radiation Lightsource, Stanford Linear Accelerator Complex National Accelerator Laboratory, Menlo Park, California (United States); Nichol, Helen [Department of Anatomy and Cell Biology, University of Saskatchewan, 107 Wiggins Rd. Rm A302, Saskatoon, SK S7N5E5 (Canada)

    2010-07-23T23:59:59.000Z

    Aim: To visualize and validate iron deposition in two cases of multiple sclerosis using rapid scanning X-Ray Fluorescence (RS-XRF) and Susceptibility Weighted Imaging (SWI). Material and Methods: Two (2) coronal cadaver brain slices from patients clinically diagnosed with multiple sclerosis underwent magnetic resonance imaging (MRI), specifically SWI to image iron content. To confirm the presence of iron deposits and the absence of zinc-rich myelin in lesions, iron and zinc were mapped using RS-XRF. Results: MS lesions were visualized using FLAIR and correlated with the absence of zinc by XRF. XRF and SWI showed that in the first MS case, there were large iron deposits proximal to the draining vein of the caudate nucleus as well as iron deposits associated with blood vessels throughout the globus pallidus. Less iron was seen in association with lesions than in the basal ganglia. The presence of larger amounts of iron correlated reasonably well between RS-XRF and SWI. In the second case, the basal ganglia appeared normal and acute perivascular iron deposition was absent. Conclusion: Perivascular iron deposition is seen in some but not all MS cases, giving credence to the use of SWI to assess iron involvement in MS pathology in vivo.

  12. Method for preparing hydrous iron oxide gels and spherules

    DOE Patents [OSTI]

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

    2003-07-29T23:59:59.000Z

    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.

  13. Mean steady granular force on a wall overflowed by free-surface gravity-driven dense flows

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    focused on the drag force on small obstacles such as cylinders in the case of rapid - dilute - granular and sharply increases the mean force at low incoming inertial numbers. A simple hydrodynamic model based this model, our study provides an example of the ability of simple hydrodynamic approaches to describe

  14. Granular Matter 2, 179187 c Springer-Verlag 2000 Effect of particle size distribution on pile tip resistance

    E-Print Network [OSTI]

    Bolton, Malcolm

    Granular Matter 2, 179­187 c Springer-Verlag 2000 Effect of particle size distribution on pile tip the specific boundary problem associated with the penetration of a model pile into two different gradings of fine particles on the pile end bearing resistance. The first grading of sand comprised particles

  15. PHYSICAL REVIEW E 85, 051302 (2012) Probing the shear-band formation in granular media with sound waves

    E-Print Network [OSTI]

    Paris 7 - Denis Diderot, Université

    , the application of these experimental methods to real 3D opaque granular materials appears difficult. Sound waves [13­17]. Speed measurements of long-wavelength sound waves allow one to determine the nonlinear scattered sound waves enable one to detect tiny changes of the contact network configuration at the grain

  16. Role of friction in pattern formation in oscillated granular layers Sung Joon Moon, # J. B. Swift, and Harry L. Swinney

    E-Print Network [OSTI]

    Texas at Austin. University of

    Role of friction in pattern formation in oscillated granular layers Sung Joon Moon, # J. B. Swift grains. Our molecular dynamics simu­ lations reveal that friction is essential for realistic modeling at a container acceleration about 30% smaller than that observed in experiments and simulations with friction

  17. Role of friction in pattern formation in oscillated granular layers Sung Joon Moon,* J. B. Swift, and Harry L. Swinney

    E-Print Network [OSTI]

    Texas at Austin. University of

    Role of friction in pattern formation in oscillated granular layers Sung Joon Moon,* J. B. Swift as there are no elastic grains. Our molecular dynamics simulations reveal that friction is essential for realistic with friction. More importantly, even though square and hexagonal patterns form for a wide range

  18. Effect of friction on the force distribution in sheared granular materials A. Singh, V. Magnanimo & S. Luding

    E-Print Network [OSTI]

    Luding, Stefan

    averaging in the steady state. Simulations of dry particles with and without friction have been validatedEffect of friction on the force distribution in sheared granular materials A. Singh, V. Magnanimo of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands. The effect of friction on the quasi

  19. MetalBosonic InsulatorSuperconductor Transition in Boron-Doped Granular Diamond Gufei Zhang,1,* Monika Zeleznik,2

    E-Print Network [OSTI]

    Bristol, University of

    . Second, the giant RðTÞ peak is observed in heavily boron-doped polycrystalline diamond thick filmsMetal­Bosonic Insulator­Superconductor Transition in Boron-Doped Granular Diamond Gufei Zhang,1 the onset of superconductivity in heavily boron-doped diamond. This anomalous RðTÞ peak in a 3D system

  20. Washboard Road: The Dynamics of Granular Ripples Formed by Rolling Wheels Nicolas Taberlet,1,2,* Stephen W. Morris,3

    E-Print Network [OSTI]

    McElwaine, Jim

    experiments on rippled granular surfaces formed under rolling wheels. Ripples appear above a critical speed surface under tangential stress is reminiscent of other sorts of wind- and water-driven ripples [2 rolled freely on the sand bed as the table rotated at a constant speed. No torque was applied

  1. ccsd-00003870,version1-11Jan2005 Importance of convection in the compaction mechanisms of anisotropic granular media

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    of the vortices and relate them to granular convection. Our results demonstrate the importance of compression of a glass cylinder of diameter D 10 cm filled with 600 g of grains (corre- sponding to a height of roughly) by vertical taps. Each tap is created by one entire period of sine wave at a fixed frequency f = 30 Hz

  2. From localization to superconductivity in granular niobium nitride thin R. Cabanel (**), J. Chaussy, J. Mazuer and J. C. Villegier (1)

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    795 From localization to superconductivity in granular niobium nitride thin films (*) R. Cabanel 300 K les variations de la résistivité de films de nitrure de niobium préparés par pulvérisation.60 - 74.70D - 81.15C Introduction. Niobium nitride studies extensively grew during the past twenty years

  3. Mechanisms for Acoustic Absorption in Dry and Weakly Wet Granular Media Th. Brunet, X. Jia,* and P. Mills

    E-Print Network [OSTI]

    Paris 7 - Denis Diderot, Université

    of a linear viscoelastic loss and a nonlinear frictional one is observed in dry media. The Mindlin model the Coulomb frictional sliding be- tween cracks and grain boundary contacts and the linear mechanism dominatedMechanisms for Acoustic Absorption in Dry and Weakly Wet Granular Media Th. Brunet, X. Jia,* and P

  4. IEEE TRANSACTIONS ON FUZZY SYSTEMS, VOL. 12, NO. 5, OCTOBER 2004 697 Granular Prototyping in Fuzzy Clustering

    E-Print Network [OSTI]

    Bargiela, Andrzej

    modeling and pattern recognition, cf. [12], [24], and [25]. Clusters are information granulesIEEE TRANSACTIONS ON FUZZY SYSTEMS, VOL. 12, NO. 5, OCTOBER 2004 697 Granular Prototyping in Fuzzy of clustering techniques [1], [3], [16], [24] and a diversity of ways in which clustering is used in fuzzy

  5. Comparison of gleptoferron iron compound to two commonly used iron supplements for the prevention of baby pig anemia

    E-Print Network [OSTI]

    Homann, Ervin R.

    1985-01-01T23:59:59.000Z

    access to soil, the pigs become anemic if they are denied access to sources of iron other than the sow's milk. Even with the best management systems, supplemental iron is required because the pig is born with limited iron body stores ((50 mg). sow.... 1957. A parenteral hematinic for the control of iron- deficiency anemia in baby pigs. N, Am. Vet. 38:6. London, E. and G. D. Twigg. 1952. (Unpublished). Maner, J. H. , W. G. Pond and R. S. Lowrey. 1959. Effect of method and level of iron...

  6. Wastewater treatment by aerobic granular biofilmWastewater treatment by aerobic granular biofilmaste ate t eat e t by ae ob c g a u a b o Aeration pulses to improve N eliminationAeration pulses to improve N-eliminationAeration pulses to improve N eliminat

    E-Print Network [OSTI]

    Wastewater treatment by aerobic granular biofilmWastewater treatment by aerobic granular wastewater treatment p p denitrification Nitrification is the oxidation from ammonium (NH +) first activated sludge for biological N-elimination is a two step process: aerobic nitrification and anoxicp g g g

  7. Remediation of the Highland Drive South Ravine, Port Hope, Ontario: Contaminated Groundwater Discharge Management Using Permeable Reactive Barriers and Contaminated Sediment Removal - 13447

    SciTech Connect (OSTI)

    Smyth, David; Roos, Gillian [Golder Associates Ltd., 2390 Argentia Road, Mississauga, ON L5N 5Z7 (Canada)] [Golder Associates Ltd., 2390 Argentia Road, Mississauga, ON L5N 5Z7 (Canada); Ferguson Jones, Andrea [MMM Group Ltd., 100 Commerce Valley Drive West, Thornhill, ON L3T 0A1 (Canada)] [MMM Group Ltd., 100 Commerce Valley Drive West, Thornhill, ON L3T 0A1 (Canada); Case, Glenn [AECL Port Hope Area Initiative Management Office, 115 Toronto Road, Port Hope, ON L1A 3S4 (Canada)] [AECL Port Hope Area Initiative Management Office, 115 Toronto Road, Port Hope, ON L1A 3S4 (Canada); Yule, Adam [Public Works and Government Services Canada, 4900 Yonge Street, 11th Floor, Toronto, ON, M2N 6A6 (Canada)] [Public Works and Government Services Canada, 4900 Yonge Street, 11th Floor, Toronto, ON, M2N 6A6 (Canada)

    2013-07-01T23:59:59.000Z

    The Highland Drive South Ravine (HDSR) is the discharge area for groundwater originating from the Highland Drive Landfill, the Pine Street North Extension (PSNE) roadbed parts of the Highland Drive roadbed and the PSNE Consolidation Site that contain historical low-level radioactive waste (LLRW). The contaminant plume from these LLRW sites contains elevated concentrations of uranium and arsenic and discharges with groundwater to shallow soils in a wet discharge area within the ravine, and directly to Hunt's Pond and Highland Drive South Creek, which are immediately to the south of the wet discharge area. Remediation and environmental management plans for HDSR have been developed within the framework of the Port Hope Project and the Port Hope Area Initiative. The LLRW sites will be fully remediated by excavation and relocation to a new Long-Term Waste Management Facility (LTWMF) as part of the Port Hope Project. It is projected, however, that the groundwater contaminant plume between the remediated LLRW sites and HDSR will persist for several hundreds of years. At the HDSR, sediment remediation within Hunt's Ponds and Highland Drive South Creek, excavation of the existing and placement of clean fill will be undertaken to remove current accumulations of solid-phase uranium and arsenic associated with the upper 0.75 m of soil in the wet discharge area, and permeable reactive barriers (PRBs) will be used for in situ treatment of contaminated groundwater to prevent the ongoing discharge of uranium and arsenic to the area in HDSR where shallow soil excavation and replacement has been undertaken. Bench-scale testing using groundwater from HDSR has confirmed excellent treatment characteristics for both uranium and arsenic using permeable reactive mixtures containing granular zero-valent iron (ZVI). A sequence of three PRBs containing ZVI and sand in backfilled trenches has been designed to intercept the groundwater flow system prior to its discharge to the ground surface and the creek and ponds in the HDSR. The first of the PRBs will be installed immediately up-gradient of the wet discharge area approximately 50 m from the creek, the other two will be installed across the area of shallow soil replacement, and all will extend from ground surface to the base of the water table aquifer through which the impacted groundwater flows. The PRBs have been designed to provide the removal of uranium and arsenic for decades, although the capacity of the treatment mixture for contaminant removal suggests that a longer period of treatment may be feasible. The environmental management plan includes an allowance for on-going monitoring, and replacement of a PRB(s) as might be required. (authors)

  8. Multiple-shocks induced nanocrystallization in iron

    SciTech Connect (OSTI)

    Matsuda, Tomoki; Hirose, Akio [Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan); Sano, Tomokazu [Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan); JST, CREST, Suita, Osaka 565-0871 (Japan); Arakawa, Kazuto [JST, CREST, Suita, Osaka 565-0871 (Japan); Department of Material Science, Interdisciplinary Faculty of Science and Engineering, Shimane University, Matsue, Shimane 690-8504 (Japan)

    2014-07-14T23:59:59.000Z

    We found that multiple shots of femtosecond laser-driven shock pulses changed coarse crystalline iron grains with a size of 140??m into nanocrystals with a high density of dislocations, which had never been observed in conventional shock processes. We performed metallurgical microstructure observations using transmission electron microscopy (TEM) and hardness measurements using nanoindentation on cross-sections of shocked iron. TEM images showed that grains with sizes from 10?nm through 1??m exist within 2??m of the surface, where the dislocation density reached 2?×?10{sup 15?}m{sup ?2}. Results of the hardness measurements showed a significant increase in hardness in the nanocrystallized region. We suggest that the formation of a high density of dislocations, which is produced by a single shock, induces local three-dimensional pile-up by the multiple-shocks, which causes grain refinement at the nanoscale.

  9. Iron-sulfide redox flow batteries

    DOE Patents [OSTI]

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

    2013-12-17T23:59:59.000Z

    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.

  10. Thin Wall Cast Iron: Phase II

    SciTech Connect (OSTI)

    Doru M. Stefanescu

    2005-07-21T23:59:59.000Z

    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.

  11. Role of microbial iron reduction in the dissolution of iron hydroxysulfate minerals - article no. G01012

    SciTech Connect (OSTI)

    Jones, E.J.P.; Nadeau, T.L.; Voytek, M.A.; Landa, E.R. [US Geological Survey, Reston, VA (United States)

    2006-03-28T23:59:59.000Z

    Reduction of structural sulfate in the iron-hydroxysulfate mineral jarosite by sulfate-reducing bacteria has previously been demonstrated. The primary objective of this work was to evaluate the potential for anaerobic dissolution of the iron-hydroxysulfate minerals jarosite and schwertmannite at neutral pH by iron-reducing bacteria. Mineral dissolution was tested using a long-term cultivar, Geobacter metallireducens strain GS-15, and a fresh isolate Geobacter sp. strain ENN1, previously undescribed. ENN1 was isolated from the discharge site of Shadle Mine, in the southern anthracite coalfield of Pennsylvania, where schwertmannite was the predominant iron-hydroxysulfate mineral. When jarosite from Elizabeth Mine (Vermont) was provided as the sole terminal electron acceptor, resting cells of both G. metallireducens and ENN1 were able to reduce structural Fe(III), releasing Fe{sup +2}, SO{sub 4}{sup -2}, and K{sup +} ions. A lithified jarosite sample from Utah was more resistant to microbial attack, but slow release of Fe{sup +2} was observed. Neither bacterium released Fe{sup +2} from poorly crystalline synthetic schwertmannite. Our results indicate that exposure of jarosite to iron-reducing conditions at neutral pH is likely to promote the mobility of hazardous constituents and should therefore be considered in evaluating waste disposal and/or reclamation options involving jarosite-bearing materials.

  12. Seal welded cast iron nuclear waste container

    DOE Patents [OSTI]

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

    1987-01-01T23:59:59.000Z

    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.

  13. Validation of GEANT4 Monte Carlo Models with a Highly Granular Scintillator-Steel Hadron Calorimeter

    E-Print Network [OSTI]

    C. Adloff; J. Blaha; J. -J. Blaising; C. Drancourt; A. Espargilière; R. Gaglione; N. Geffroy; Y. Karyotakis; J. Prast; G. Vouters; K. Francis; J. Repond; J. Schlereth; J. Smith; L. Xia; E. Baldolemar; J. Li; S. T. Park; M. Sosebee; A. P. White; J. Yu; T. Buanes; G. Eigen; Y. Mikami; N. K. Watson; G. Mavromanolakis; M. A. Thomson; D. R. Ward; W. Yan; D. Benchekroun; A. Hoummada; Y. Khoulaki; J. Apostolakis; A. Dotti; G. Folger; V. Ivantchenko; V. Uzhinskiy; M. Benyamna; C. Cârloganu; F. Fehr; P. Gay; S. Manen; L. Royer; G. C. Blazey; A. Dyshkant; J. G. R. Lima; V. Zutshi; J. -Y. Hostachy; L. Morin; U. Cornett; D. David; G. Falley; K. Gadow; P. Göttlicher; C. Günter; B. Hermberg; S. Karstensen; F. Krivan; A. -I. Lucaci-Timoce; S. Lu; B. Lutz; S. Morozov; V. Morgunov; M. Reinecke; F. Sefkow; P. Smirnov; M. Terwort; A. Vargas-Trevino; N. Feege; E. Garutti; I. Marchesinik; M. Ramilli; P. Eckert; T. Harion; A. Kaplan; H. -Ch. Schultz-Coulon; W. Shen; R. Stamen; B. Bilki; E. Norbeck; Y. Onel; G. W. Wilson; K. Kawagoe; P. D. Dauncey; A. -M. Magnan; V. Bartsch; M. Wing; F. Salvatore; E. Calvo Alamillo; M. -C. Fouz; J. Puerta-Pelayo; B. Bobchenko; M. Chadeeva; M. Danilov; A. Epifantsev; O. Markin; R. Mizuk; E. Novikov; V. Popov; V. Rusinov; E. Tarkovsky; N. Kirikova; V. Kozlov; P. Smirnov; Y. Soloviev; P. Buzhan; A. Ilyin; V. Kantserov; V. Kaplin; A. Karakash; E. Popova; V. Tikhomirov; C. Kiesling; K. Seidel; 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; J. Fleury; T. Frisson; 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. Boudry; J-C. Brient; D. Jeans; P. Mora de Freitas; G. Musat; M. Reinhard; M. Ruan; H. Videau; B. Bulanek; 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; B. Belhorma; H. Ghazlane; T. Takeshita; S. Uozumi; M. Götze; O. Hartbrich; J. Sauer; S. Weber; C. Zeitnitz

    2014-06-15T23:59:59.000Z

    Calorimeters with a high granularity are a fundamental requirement of the Particle Flow paradigm. This paper focuses on the prototype of a hadron calorimeter with analog readout, consisting of thirty-eight scintillator layers alternating with steel absorber planes. The scintillator plates are finely segmented into tiles individually read out via Silicon Photomultipliers. The presented results are based on data collected with pion beams in the energy range from 8GeV to 100GeV. The fine segmentation of the sensitive layers and the high sampling frequency allow for an excellent reconstruction of the spatial development of hadronic showers. A comparison between data and Monte Carlo simulations is presented, concerning both the longitudinal and lateral development of hadronic showers and the global response of the calorimeter. The performance of several GEANT4 physics lists with respect to these observables is evaluated.

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

    E-Print Network [OSTI]

    Takahiro Hatano

    2008-11-09T23:59:59.000Z

    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.

  15. Modeling Granular Materials as Compressible Non-Linear Fluids: Heat Transfer Boundary Value Problems

    SciTech Connect (OSTI)

    Massoudi, M.C.; Tran, P.X.

    2006-01-01T23:59:59.000Z

    We discuss three boundary value problems in the flow and heat transfer analysis in flowing granular materials: (i) the flow down an inclined plane with radiation effects at the free surface; (ii) the natural convection flow between two heated vertical walls; (iii) the shearing motion between two horizontal flat plates with heat conduction. It is assumed that the material behaves like a continuum, similar to a compressible nonlinear fluid where the effects of density gradients are incorporated in the stress tensor. For a fully developed flow the equations are simplified to a system of three nonlinear ordinary differential equations. The equations are made dimensionless and a parametric study is performed where the effects of various dimensionless numbers representing the effects of heat conduction, viscous dissipation, radiation, and so forth are presented.

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

    E-Print Network [OSTI]

    Athanassiadis, Athanasios G; Sidky, Emil; Pelizzari, Charles; Pan, Xiaochuan; Jaeger, Heinrich M

    2014-01-01T23:59:59.000Z

    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)$^3$ field of view. By analyzing the performance bounds of the system, we demonstrate that the reconstructions exhibit only moderate noise.

  17. Coherent Transport and Symmetry Breaking - Laser Dynamics of Constrained Granular Matter

    E-Print Network [OSTI]

    Andreas Lubatsch; Regine Frank

    2014-08-14T23:59:59.000Z

    We present diagrammatic transport theory including self-consistent nonlinear enhancement and dissipation in the multiple scattering regime. Our model of Vollhardt-W\\"olfle transport of photons is fit-parameter-free and raises the claim that the results hold up to the closest packed volume of randomly arranged ZnO Mie scatterers. We find that a symmetry breaking caused by dissipative effects of a lossy underlying substrate leads to qualitatively different physics of coherence and lasing in granular amplifying media. According to our results, confined and extended mode and their laser thresholds can be clearly attributed to unbroken and broken spatial symmetry. The diameters and emission profiles of random laser modes, as well as their thresholds and the positional-dependent degree of coherence can be checked experimentally.

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

    E-Print Network [OSTI]

    Ricardo Brito; Rodrigo Soto

    2010-12-21T23:59:59.000Z

    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.

  19. Unified Theory of Inertial Granular Flows and Non-Brownian Suspensions

    E-Print Network [OSTI]

    E. DeGiuli; G. Düring; E. Lerner; M. Wyart

    2015-05-28T23:59:59.000Z

    Rheological properties of dense flows of hard particles are singular as one approaches the jamming threshold where flow ceases, both for aerial granular flows dominated by inertia, and for over-damped suspensions. Concomitantly, the lengthscale characterizing velocity correlations appears to diverge at jamming. Here we introduce a theoretical framework that proposes a tentative, but potentially complete scaling description of stationary flows. Our analysis, which focuses on frictionless particles, applies {\\it both} to suspensions and inertial flows of hard particles. We compare our predictions with the empirical literature, as well as with novel numerical data. Overall we find a very good agreement between theory and observations, except for frictional inertial flows whose scaling properties clearly differ from frictionless systems. For over-damped flows, more observations are needed to decide if friction is a relevant perturbation or not. Our analysis makes several new predictions on microscopic dynamical quantities that should be accessible experimentally.

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

    E-Print Network [OSTI]

    Athanasios G Athanassiadis; Patrick J. La Rivière; Emil Sidky; Charles Pelizzari; Xiaochuan Pan; Heinrich M. Jaeger

    2014-07-28T23:59:59.000Z

    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)$^3$ field of view. By analyzing the performance bounds of the system, we demonstrate that the reconstructions exhibit only moderate noise.

  1. 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)

    2007-12-18T23:59:59.000Z

    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).

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

    E-Print Network [OSTI]

    Pöschl, R

    2015-01-01T23:59:59.000Z

    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.

  3. Hadronic energy resolution of a highly granular scintillator-steel hadron calorimeter using software compensation techniques

    E-Print Network [OSTI]

    CALICE Collaboration; C. Adloff; J. Blaha; J. -J. Blaising; C. Drancourt; A. Espargilière; R. Gaglione; N. Geffroy; Y. Karyotakis; J. Prast; G. Vouters; K. Francis; J. Repond; J. Smith; L. Xia; E. Baldolemar; J. Li; S. T. Park; M. Sosebee; A. P. White; J. Yu; T. Buanes; G. Eigen; Y. Mikami; N. K. Watson; T. Goto; G. Mavromanolakis; M. A. Thomson; D. R. Ward; W. Yan; D. Benchekroun; A. Hoummada; Y. Khoulaki; M. Benyamna; C. Cârloganu; F. Fehr; P. Gay; S. Manen; L. Royer; G. C. Blazey; A. Dyshkant; J. G. R. Lima; V. Zutshi; J. -Y. Hostachy; L. Morin; U. Cornett; D. David; G. Falley; K. Gadow; P. Göttlicher; C. Günter; B. Hermberg; S. Karstensen; F. Krivan; A. -I. Lucaci-Timoce; S. Lu; B. Lutz; S. Morozov; V. Morgunov; M. Reinecke; F. Sefkow; P. Smirnov; M. Terwort; A. Vargas-Trevino; N. Feege; E. Garutti; I. Marchesini; M. Ramilli; P. Eckert; T. Harion; A. Kaplan; H. -Ch. Schultz-Coulon; W. Shen; R. Stamen; A. Tadday; B. Bilki; E. Norbeck; Y. Onel; G. W. Wilson; K. Kawagoe; P. D. Dauncey; A. -M. Magnan; M. Wing; F. Salvatore; E. Calvo Alamillo; M. -C. Fouz; J. Puerta-Pelayo; V. Balagura; B. Bobchenko; M. Chadeeva; M. Danilov; A. Epifantsev; O. Markin; R. Mizuk; E. Novikov; V. Rusinov; E. Tarkovsky; N. Kirikova; V. Kozlov; P. Smirnov; Y. Soloviev; P. Buzhan; B. Dolgoshein; A. Ilyin; V. Kantserov; V. Kaplin; A. Karakash; E. Popova; S. Smirnov; C. Kiesling; S. Pfau; K. Seidel; F. Simon; C. Soldner; M. Szalay; M. Tesar; L. Weuste; J. Bonis; B. Bouquet; S. Callier; P. Cornebise; Ph. Doublet; F. Dulucq; M. Faucci Giannelli; J. Fleury; H. Li; G. Martin-Chassard; F. Richard; Ch. de la Taille; R. Pöschl; L. Raux; N. Seguin-Moreau; F. Wicek; M. Anduze; V. Boudry; J-C. Brient; D. Jeans; P. Mora de Freitas; G. Musat; M. Reinhard; M. Ruan; H. Videau; B. Bulanek; 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; B. Belhorma; H. Ghazlane; T. Takeshita; S. Uozumi; J. Sauer; S. Weber; C. Zeitnitz

    2012-09-27T23:59:59.000Z

    The energy resolution of a highly granular 1 m3 analogue scintillator-steel hadronic calorimeter is studied using charged pions with energies from 10 GeV to 80 GeV at the CERN SPS. The energy resolution for single hadrons is determined to be approximately 58%/sqrt(E/GeV}. This resolution is improved to approximately 45%/sqrt(E/GeV) with software compensation techniques. These techniques take advantage of the event-by-event information about the substructure of hadronic showers which is provided by the imaging capabilities of the calorimeter. The energy reconstruction is improved either with corrections based on the local energy density or by applying a single correction factor to the event energy sum derived from a global measure of the shower energy density. The application of the compensation algorithms to Geant4 simulations yield resolution improvements comparable to those observed for real data.

  4. 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)

    2014-08-15T23:59:59.000Z

    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.

  5. JOURNAL DE PHYSIQUE Colloque C6, supplment au no 12, Tome 35, Dcembre 1974,page C6-393 SUPERCONDUCTIVITY AND LATTICE DYNAMICS OF GRANULAR TIN (*)

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    -393 SUPERCONDUCTIVITY AND LATTICE DYNAMICS OF GRANULAR TIN (*) S. AKSELROD, M. PASTERNAK Physics Department, Tel was measured in samples of 4 5 8 Sn grains embedded in a tin-oxide matrix. The Debye temperature of the same

  6. Granular materials such as sand, rice and coffee beans are so common that we hardly ever realize how unique their properties are. Who marvels at the fact one

    E-Print Network [OSTI]

    Hille, Sander

    Summary Granular materials such as sand, rice and coffee beans are so common that we hardly ever will notice the surprising fact that we can tune the rapidity and thickness of the stream of coffee beans

  7. An Investigation on Granular-Nanocomposite-Based Giant Magnetoresistance (GMR) Sensor Fabrication

    E-Print Network [OSTI]

    Guo, John Zhanhu

    composites reinforced with iron nanoparticles which has been heat treated was reported. The flexible to conductive composites. The coercive forces reflect strong particle loading and matrix dependent magnetic of adjacent ferromagnetic layers in a GMR material are antiparallel due to a weak anti-ferromagnetic coupling

  8. Iron phosphate compositions for containment of hazardous metal waste

    DOE Patents [OSTI]

    Day, D.E.

    1998-05-12T23:59:59.000Z

    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.

  9. Iron phosphate compositions for containment of hazardous metal waste

    DOE Patents [OSTI]

    Day, Delbert E. (Rolla, MO)

    1998-01-01T23:59:59.000Z

    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.

  10. Iron Networks Microsoft Fast Track Architecture Reference Architecture Technical White Paper

    E-Print Network [OSTI]

    Chaudhuri, Surajit

    Iron Networks Microsoft Fast Track Architecture Reference Architecture Technical White Paper Iron://www.ironnetworks.com #12;Iron Networks IronPOD Fast Track Hyper-V Private Cloud - 2 Copyright©2014 Iron-V Private Cloud - 3 Contents 1 Introduction

  11. 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

    2011-09-21T23:59:59.000Z

    : #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...

  12. Reduction and carburization reactions in the iron bath smelter

    SciTech Connect (OSTI)

    Uemura, Kenichiro

    1993-01-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Carnes, Misty Lee

    2002-01-01T23:59:59.000Z

    . . . . . . . . . . . . . . . . Growth of R. equi in minimal media (MM) and MM without iron 66 (MM-Fe) . . 67 12 13 Growth of R. equi in 100 ItM DIP + varying iron concentrations. . . . . . . . . 68 Effects of iron source (FeSO& or FeCls) onin vitro growth of R. equi. . . 69.... , virulence factors) against oxidative stress Three types of bacterial SODs have been described: those that contain either iron (Fe SOD), manganese (MnSOD), or copper-zinc (Cu-ZnSOD)(85). If the appropriate minerals are not available for production of SODs...

  14. Australian Mining carries rare-earth-like iron release | The...

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

    Australian Mining carries rare-earth-like iron release Australian Mining, the leading news source for the mining industry in Australia, carried a story on research Ames Lab...

  15. Influence of Iron Redox Transformations on Plutonium Sorption...

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

    and Pu(V) reduction demonstrates the potential impact of changing iron mineralogy on plutonium subsurface transport through redox transition areas. These findings...

  16. 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

    2010-01-01T23:59:59.000Z

    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).

  17. Percolation Explains How Earth's Iron Core Formed | Stanford...

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

    history. Earth's present layered structure with a metallic core and an overlying silicate mantle would have required mechanisms to separate iron alloy from a silicate phase....

  18. 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...

  19. approved iron nanoparticles: Topics by E-print Network

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

    thickness on magnetic interactions in self-assembled single domain iron nanoparticles Materials Science Websites Summary: of Mechanical and Chemical Engineering, North Carolina...

  20. Argonne scientists discover new magnetic phase in iron-based...

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

    neutron diffraction image giving evidence for the new magnetic phase in iron-based superconductors discovered by Argonne scientists. It shows the scattering results from a sample...

  1. 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)

    1997-08-19T23:59:59.000Z

    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.

  2. Metal regeneration of iron chelates in nitric oxide scrubbing

    DOE Patents [OSTI]

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

    1997-08-19T23:59:59.000Z

    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. Iron Speciation and Mixing in Single Aerosol Particles from the...

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

    iron from atmospheric aerosol is an essential nutrient that can control oceanic productivity, thereby impacting the global carbon budget and climate. Particles collected on...

  4. 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 ...

  5. Climate VISION: Private Sector Initiatives: Iron and Steel: Resources...

    Office of Scientific and Technical Information (OSTI)

    Publications The Industrial Technologies Program offers a wide array of publications, videos, software, and other information products for improving energy efficiency in the iron...

  6. The effects of copper and iron deficiencies in the chick

    E-Print Network [OSTI]

    McGhee, Flin Cameron

    1964-01-01T23:59:59.000Z

    was assimilated by the chick. Cunningham (1931) and Josephs (1932) found that rats fed a milk diet plus iron showed no significant difference from rats fed milk plus sources of copper and iron. Elvehjem and Sherman (1932) reported that when rats de- ficient.../or iron as follows: Group Group Group Group Group Group 1 ? no added copper or iron 2 - cupric sulfate added (5 ppm) 3 - cupric oxide added (5 ppm) 4 ? ferrous sulfate added (40 ppm) 5 - cupric sulfate (5 ppm) plus ferrous sulfate added (40 ppm...

  7. Formation of iron complexs from trifluoroacetic acid based liquid...

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

    Instead these ions are clusters of trifluoroacetic acid formed in association with acetonitrile, water and iron from the stainless steel union used to connect the column with the...

  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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12 Investigation Peer Review 2012IowaFebruaryIronIronIronIron

  9. Iron-Air Rechargeable Battery: A Robust and Inexpensive Iron-Air Rechargeable Battery for Grid-Scale Energy Storage

    SciTech Connect (OSTI)

    None

    2010-10-01T23:59:59.000Z

    GRIDS Project: USC is developing an iron-air rechargeable battery for large-scale energy storage that could help integrate renewable energy sources into the electric grid. Iron-air batteries have the potential to store large amounts of energy at low cost—iron is inexpensive and abundant, while oxygen is freely obtained from the air we breathe. However, current iron-air battery technologies have suffered from low efficiency and short life spans. USC is working to dramatically increase the efficiency of the battery by placing chemical additives on the battery’s iron-based electrode and restructuring the catalysts at the molecular level on the battery’s air-based electrode. This can help the battery resist degradation and increase life span. The goal of the project is to develop a prototype iron-air battery at significantly cost lower than today’s best commercial batteries.

  10. Suspension Hydrogen Reduction of Iron Oxide Concentrates

    SciTech Connect (OSTI)

    H.Y. Sohn

    2008-03-31T23:59:59.000Z

    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. Carbon Emissions: Iron and Steel Industry

    Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33 111 1,613 122 40CoalLease(Billion2,128 2,469 2,321Spain (Million Cubic Feet)Iron and Steel

  12. 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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated Codes | NationalCurriculum IntroductionInvestor14,566 SiteIron

  13. 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 onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere I Geothermal Pwer Plant Jump to: navigation, search GEOTHERMALTexas:Kuju Kanko Hotel GeothermalKumba Iron Ore

  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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12 Investigation Peer Review 2012IowaFebruary 9,JanuaryIron

  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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12 Investigation Peer Review 2012IowaFebruaryIron Availability

  16. 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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12 Investigation Peer Review 2012IowaFebruaryIron

  17. INVESTIGATION OF THE RATE DEPENDENCE OF LONG-ROD PENETRATION OF GRANULAR MEDIA USING AN IMPROVED DSR ALGORITHM

    SciTech Connect (OSTI)

    Addiss, John W.; Collins, Adam L.; Proud, William G. [Fracture and Shock Physics, SMF Group, Cavendish Laboratory, J. J. Thomson Ave., Cambridge, CB3 OHE (United Kingdom)

    2009-12-28T23:59:59.000Z

    Digital Speckle Radiography (DSR), a technique allowing measurement of the full field displacement maps in a plane within an opaque material, is used to follow the temporal progression of a long-rod (100 mm long, 10 mm diameter) penetrating a granular sample at a variety of rates. Quasi-static rates of 1.5 mm/min are achieved using an Instron machine, 5 m/s is achieved using a drop-weight and velocities between 10 and 200 m/s are achieved using a light gas gun. These experiments are carried out using a series of time delayed flash x-ray images analysed with an optimised Digital Image Cross Correlation algorithm (DICC). The subsequent data sheds considerable light on the response of granular materials to penetration at a variety of rates. Particularly, a large difference in the response of the material between quasi-static and dynamic rates is observed.

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

    E-Print Network [OSTI]

    MATHIEU, JOHANNA L.

    2010-01-01T23:59:59.000Z

    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

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

    E-Print Network [OSTI]

    Cordero, Otto X.

    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 ...

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

    E-Print Network [OSTI]

    Nolan, William Rane

    2009-01-01T23:59:59.000Z

    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 ...

  1. Moessbauer studies of iron hydride at high pressure

    SciTech Connect (OSTI)

    Choe, I.; Ingalls, R. (Department of Physics, FM-15, University of Washington, Seattle, Washington 98195 (USA)); Brown, J.M.; Sato-Sorensen, Y. (Geophysics Program, AK-50, University of Washington, Seattle, Washington 98195 (USA)); Mills, R. (Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (USA))

    1991-07-01T23:59:59.000Z

    We have measured {ital in} {ital situ} Moessbauer spectra of iron hydride made in a diamond anvil cell at high pressure and room temperature. The spectra show a sudden change at 3.5{plus minus}0.5 GPa from a single hyperfine pattern to a superposition of three. The former pattern results from normal {alpha}-iron with negligible hydrogen content, and the latter from residual {alpha}-iron plus newly formed iron hydride. Between 3.5 and 10.4 GPa, the extra hydride pattern have hyperfine fields for one ranging from 276 to 263 kOe, and the other, from 317 to 309 kOe. Both have isomer shifts of about 0.4 mm/sec, and negligible quadrupole splittings. X-ray studies on quenched samples have shown that iron hydride is of double hexagonal close-packed structure, whose two nonequivalent iron sites may account for the observation of two different patterns. Even allowing for the effect of volume expansion, the observed isomer shifts for the hydride are considerably more positive than those of other metallic phases of iron. At the same time, the hyperfine fields are slightly smaller than that of {alpha}-iron. As a possible explanation, one may expect a bonding of hydrogen with iron, which would result in a small reduction of 4{ital s} electrons, possibly accompanied by a small increase of 3{ital d} electrons compared with the neutral atom in metallic iron. The difference between the hyperfine fields in the two spectra are presumably due to the different symmetry at the two iron sites.

  2. 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

    2011-05-24T23:59:59.000Z

    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.

  3. Tap Density Equations of Granular Powders Based on the Rate Process Theory and the Free Volume Concept

    E-Print Network [OSTI]

    Tian Hao

    2014-09-05T23:59:59.000Z

    Tap density of a granular powder is often linked to the flowability via Carr Index that measures how tight a powder can be packed, under an assumption that more easily packed powders usually flow poorly. Understanding how particles are packed is important for revealing why a powder flows better than others. There are two types of empirical equations that were proposed to fit the experimental data of packing fractions vs. numbers of taps in literature: The inverse logarithmic and the stretched exponential. Using the rate process theory and the free volume concept, we obtain the tap density equations and they can be reducible to the two empirical equations currently widely used in literature. Our equations could potentially fit experimental data better with an additional adjustable parameter. The tapping amplitude and frequency, the weight of the granular materials, and the environment temperature are grouped into one parameter that weighs the pace of packing process. The current results, in conjunction with our previous findings, may imply that both dry(granular)and wet(colloidal and polymeric) particle systems are governed by the same physical mechanisms in term of the role of the free volume and how particles behave (a rate controlled process).

  4. Investigation of Iron Aluminide Weld Overlays

    SciTech Connect (OSTI)

    Banovic, S.W.; DuPont, J.B.; Levin, B.F.; Marder, A.R.

    1999-08-02T23:59:59.000Z

    Conventional fossil fired boilers have been retrofitted with low NO(sub)x burners in order for the power plants to comply with new clean air regulations. Due to the operating characteristics of these burners, boiler tube sulfidation corrosion typically has been enhanced resulting in premature tube failure. To protect the existing panels from accelerated attack, weld overlay coatings are typically being applied. By depositing an alloy that offers better corrosion resistance than the underlying tube material, the wastage rates can be reduced. While Ni-based and stainless steel compositions are presently providing protection, they are expensive and susceptible to failure via corrosion-fatigue due to microsegregation upon solidification. Another material system presently under consideration for use as a coating in the oxidation/sulfidation environments is iron-aluminum. These alloys are relatively inexpensive, exhibit little microsegregation, and show excellent corrosion resistance. However, their use is limited due to weldability issues and their lack of corrosion characterization in simulated low NO(sub)x gas compositions. Therefore a program was initiated in 1996 to evaluate the use of iron-aluminum weld overlay coatings for erosion/corrosion protection of boiler tubes in fossil fired boilers with low NO(sub)x burners. Investigated properties included weldability, corrosion behavior, erosion resistance, and erosion-corrosion performance.

  5. Complement receptor type 2conjugated superparamagnetic iron oxide nanoparticles

    E-Print Network [OSTI]

    Levin, Judith G.

    Complement receptor type 2­conjugated superparamagnetic iron oxide nanoparticles [CR2-Fc-SPIO] Kam: Complement receptor type 2­conjugated gold/superparamagnetic iron oxide nanoparticles Abbreviated name: CR2, and oligodendroglial cells. SPIO nanoparticles are sometimes modified with dextran, poly(ethylene glycol) (PEG

  6. Enhanced Superconducting Properties of Iron Chalcogenide Thin Films

    E-Print Network [OSTI]

    Chen, Li

    2013-07-26T23:59:59.000Z

    Among the newly discovered iron-based superconductor, FeSe with the simplest structure and a transition temperature (T_c) around 8 K arouses much research interest. Although its Tc is much lower than that of the cuprates, iron chalcogenide has low...

  7. atmospheric iron corrosion: Topics by E-print Network

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

    atmospheric iron corrosion First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Atmospheric Iron Deposition:...

  8. Electrodeposition of hybrid organicinorganic films containing iron oxide

    E-Print Network [OSTI]

    Niewczas, Marek

    Electrodeposition of hybrid organic­inorganic films containing iron oxide I. Zhitomirsky *, M has been developed for the preparation of hybrid organic­inorganic films containing iron oxide properties could be varied. Magnetic measurements revealed that the nanocomposite films are superparamagnetic

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

    E-Print Network [OSTI]

    Pollard, Richard

    2012-01-01T23:59:59.000Z

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

  10. Trophic status of Chlamydomonas reinhardtii influences the impact of iron deficiency on photosynthesis

    E-Print Network [OSTI]

    Terauchi, Aimee M.; Peers, Graham; Kobayashi, Marilyn C.; Niyogi, Krishna K.; Merchant, Sabeeha S.

    2010-01-01T23:59:59.000Z

    of iron de?ciency on photosynthesis Aimee M. Terauchi •rates by suppress- ing photosynthesis but increasing insteadal. 2007). In oxygenic photosynthesis, iron is a cofactor in

  11. Using Disorder to Study How Electrons Pair in Iron-Based Superconducto...

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

    Using Disorder to Study How Electrons Pair in Iron-Based Superconductors Researchers introduced disorder to test electron pairing in iron-based superconductors and produced...

  12. 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)

    2011-09-20T23:59:59.000Z

    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.

  13. 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

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

    E-Print Network [OSTI]

    Utrecht, Universiteit

    for specific dissolution of magnetic minerals from soils and sediments. To prevent changes in the extractionSelective dissolution of magnetic iron oxides in the acid­ammonium oxalate/ferrous iron extraction the pedogenic magnetic fractions. Sequential extraction techniques have therefore been incorporated

  15. Biodegradation of methyl tertiary butyl ether (MTBE) using a granular activated carbon trickling filter

    SciTech Connect (OSTI)

    Converse, B.M.; Schroeder, E.D.; Chang, D.P.Y.

    1999-07-01T23:59:59.000Z

    A pilot scale trickling filter was constructed using granular activated carbon (GAC) as the packing medium and inoculated with a microbial culture known to degrade MTBE. The packing dimensions were 0.076 m in diameter and 0.22 m deep. The unit operated with recycling flow for two months before a biofilm was observed on the GAC. After two additional months the biofilm had visibly spread throughout the packing. A few pieces of GAC were placed in a sealed bottle with MTBE-contaminated water and nutrients. Headspace analysis performed over 14 days confirmed that MTBE degradation was occurring. The trickling filter was converted to continuous flow and operated for one month at a nominal flow rate of 0.1 L/min and a hydraulic loading rate of 32 m{sup 3}/m{sup 2}-d. Samples were collected for analysis at the spray nozzle and at the bottom of the trickling filter. Fractional removal varied with influent MTBE concentration, temperature and liquid flow rate. Percent MTBE removal was as high as 85%. A mechanical failure resulted in the trickling filter bed drying and percent removal dropping to less than 1 percent. However, the system recovered within five days.

  16. Distribution of contact forces in a homogeneous granular material of identical spheres under triaxial compression

    E-Print Network [OSTI]

    P. Evesque

    2005-06-23T23:59:59.000Z

    The distribution P(F) of contact forces F in a homogeneous isotropic disordered granular sample subject to uniform triaxial stress field is studied using a model where forces propagate and collide. Collisions occur at grain and obey given rules which allow satisfying local static equilibrium. Analogy with Boltzmann's equation of density evolution is drawn and used to derive the parameters that control the distribution Ps(F) of contact forces F in the stationary state in case of a packing of mono-disperse spheres. Using symmetry argument and mean field approximation, it is found that stationarity is achieved when the density Ps(F) of force can be written as the product of exponentials of quantities whose sums are preserved during collisions. This introduces 3 parameters in 2d and 6 in 3d which are the mean force components {Fxo, Fyo, Fzo}, and the mean torques of the force on a grain {Mxo, Myo, Mzo} >. Astonishingly, it seems that the theory cannot include distribution of contact orientation implicitly. Extension of the model is possible with some care to case of anisotropic packing. Pacs # : 5.40 ; 45.70 ; 62.20 ; 83.70.Fn

  17. Organic and nitrogen removal from landfill leachate in aerobic granular sludge sequencing batch reactors

    SciTech Connect (OSTI)

    Wei Yanjie [School of Environmental Science and Engineering, Tianjin University, Tianjin 300072 (China); Key Laboratory of Environmental Protection in Water Transport Engineering Ministry of Communications, Tianjin Research Institute of Water Transport Engineering, Tianjin 300456 (China); Ji Min, E-mail: jmtju@yahoo.cn [School of Environmental Science and Engineering, Tianjin University, Tianjin 300072 (China); Li Ruying [School of Environmental Science and Engineering, Tianjin University, Tianjin 300072 (China); Qin Feifei [Tianjin Tanggu Sino French Water Supply Co. Ltd., Tianjin 300450 (China)

    2012-03-15T23:59:59.000Z

    Highlights: Black-Right-Pointing-Pointer Aerobic granular sludge SBR was used to treat real landfill leachate. Black-Right-Pointing-Pointer COD removal was analyzed kinetically using a modified model. Black-Right-Pointing-Pointer Characteristics of nitrogen removal at different ammonium inputs were explored. Black-Right-Pointing-Pointer DO variations were consistent with the GSBR performances at low ammonium inputs. - Abstract: Granule sequencing batch reactors (GSBR) were established for landfill leachate treatment, and the COD removal was analyzed kinetically using a modified model. Results showed that COD removal rate decreased as influent ammonium concentration increasing. Characteristics of nitrogen removal at different influent ammonium levels were also studied. When the ammonium concentration in the landfill leachate was 366 mg L{sup -1}, the dominant nitrogen removal process in the GSBR was simultaneous nitrification and denitrification (SND). Under the ammonium concentration of 788 mg L{sup -1}, nitrite accumulation occurred and the accumulated nitrite was reduced to nitrogen gas by the shortcut denitrification process. When the influent ammonium increased to a higher level of 1105 mg L{sup -1}, accumulation of nitrite and nitrate lasted in the whole cycle, and the removal efficiencies of total nitrogen and ammonium decreased to only 35.0% and 39.3%, respectively. Results also showed that DO was a useful process controlling parameter for the organics and nitrogen removal at low ammonium input.

  18. 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

    2015-05-14T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Berryman, J.G.

    2009-11-20T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Riccardo Artoni; Patrick Richard

    2015-03-09T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Seaman, John C.

    1990-01-01T23:59:59.000Z

    A&M University Chair of Advisory Committee: Dr. Richard H. Loeppert Amorphous iron (Fe) oxides are of interest because of their high reactivity, surface area, and influence on Fe availability in the soil environment. These materials may have... potential utilization as slow-release Fe amendments for calcareous soils. The objective of this study was to evaluate the impact of various concentrations of silicon (Si), present during precipitation, on the dissolution kinetics of amorphous Fe oxides...

  2. Multiple hearth furnace for reducing iron oxide

    DOE Patents [OSTI]

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

    2012-03-13T23:59:59.000Z

    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).

  3. 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

    2013-09-17T23:59:59.000Z

    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.

  4. 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)

    2012-01-17T23:59:59.000Z

    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.

  5. Iron and steel industry process model

    SciTech Connect (OSTI)

    Sparrow, F.T.; Pilati, D.; Dougherty, T.; McBreen, E.; Juang, L.L.

    1980-01-01T23:59:59.000Z

    The iron and steel industry process model depicts expected energy-consumption characteristics of the iron and steel industry and ancillary industries for the next 25 years by means of a process model of the major steps in steelmaking, from ore mining and scrap recycling to the final finishing of carbon, alloy, and stainless steel into steel products such as structural steel, slabs, plates, tubes, and bars. Two plant types are modeled: fully integrated mills and mini-mills. User-determined inputs into the model are as follows: projected energy and materials prices; projected costs of capacity expansion and replacement; energy-conserving options, both operating modes and investments; the internal rate of return required on investment; and projected demand for finished steel. Nominal input choices in the model for the inputs listed above are as follows: National Academy of Sciences Committee on Nuclear and Alternative Energy Systems Demand Panel nominal energy-price projections for oil, gas, distillates, residuals, and electricity and 1975 actual prices for materials; actual 1975 costs; new technologies added; 15% after taxes; and 1975 actual demand with 1.5%/y growth. The model reproduces the base-year (1975) actual performance of the industry; then, given the above nominal input choices, it projects modes of operation and capacity expansion that minimize the cost of meeting the given final demands for each of 5 years, each year being the midpoint of a 5-year interval. The output of the model includes the following: total energy use and intensity (Btu/ton) by type, by process, and by time period; energy conservation options chosen; utilization rates for existing capacity; capital-investment decisions for capacity expansion.

  6. 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.

    2012-06-01T23:59:59.000Z

    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.

  7. 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)

    2010-07-10T23:59:59.000Z

    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.

  8. Iron/soot interaction in a laminar ethylene nonpremixed flame

    SciTech Connect (OSTI)

    Zhang, J.; Megaridis, C.M. [Univ. of Illinois, Chicago, IL (United States). Dept. of Mechanical Engineering

    1994-12-31T23:59:59.000Z

    A laminar, coannular, ethylene/air nonpremixed flame doped with ferrocene additive is employed to address the fundamental question of how iron becomes incorporated into the carbonaceous soot phase, thus interfering with the soot formation processes. The structure and chemical composition of individual aggregates are characterized with respect to flame coordinates via a combination of thermophoretic sampling, transmission electron microscopy, and energy dispersive spectrometry. Soot aggregate microstructure clearly reveals iron occlusion, as well as stratification of soot layers over the occluded phase. The study provides physical evidence that the soot and iron compounds combine in the flame to form a hybrid (inhomogeneous) particulate phase. The reported observations are consistent with the hypothesis that ferrocene decomposes early in the combustion process and before the onset of soot particle inception, thus forming a fine aerosol for the subsequent deposition of carbonaceous substances. Examination of a series of inhomogeneous soot aggregates shows that the flame aerosol composition varies with flame coordinates. In particular, aggregates transported in the soot annulus near the luminous flame front are primarily composed of carbon and oxygen, with traces of iron finely dispersed through the aggregate matrix. On the other hand, carbonaceous soot transported at low heights and near the flame axis contains iron in its elemental form. Finally, soot aggregates in all other areas of the flame contain both iron and oxygen, thus implying the possible presence of iron oxides within the carbonaceous matrix.

  9. Iron aluminide alloy coatings and joints, and methods of forming

    DOE Patents [OSTI]

    Wright, R.N.; Wright, J.K.; Moore, G.A.

    1994-09-27T23:59:59.000Z

    Disclosed is a method of joining two bodies together, at least one of the bodies being predominantly composed of metal, the two bodies each having a respective joint surface for joining with the joint surface of the other body, the two bodies having a respective melting point, includes the following steps: (a) providing aluminum metal and iron metal on at least one of the joint surfaces of the two bodies; (b) after providing the aluminum metal and iron metal on the one joint surface, positioning the joint surfaces of the two bodies in juxtaposition against one another with the aluminum and iron positioned therebetween; (c) heating the aluminum and iron on the juxtaposed bodies to a temperature from greater than or equal to 600 C to less than the melting point of the lower melting point body; (d) applying pressure on the juxtaposed surfaces; and (e) maintaining the pressure and the temperature for a time period effective to form the aluminum and iron into an iron aluminide alloy joint which bonds the juxtaposed surfaces and correspondingly the two bodies together. The method can also effectively be used to coat a body with an iron aluminide coating.

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

    E-Print Network [OSTI]

    Morrissey, John Paul

    2013-11-28T23:59:59.000Z

    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 ...

  11. 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)

    2014-07-21T23:59:59.000Z

    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.

  12. Iron-carbon compacts and process for making them

    DOE Patents [OSTI]

    Sheinberg, Haskell (Santa Fe, NM)

    2000-01-01T23:59:59.000Z

    The present invention includes iron-carbon compacts and a process for making them. The process includes preparing a slurry comprising iron powder, furfuryl alcohol, and a polymerization catalyst for initiating the polymerization of the furfuryl alcohol into a resin, and heating the slurry to convert the alcohol into the resin. The resulting mixture is pressed into a green body and heated to form the iron-carbon compact. The compact can be used as, or machined into, a magnetic flux concentrator for an induction heating apparatus.

  13. 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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated Codes | NationalCurriculum IntroductionInvestor14,566 SiteIronIronIron

  14. 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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12 Investigation Peer Review 2012IowaFebruaryIronIronIron

  15. Insulating state of granular superconductors in a strong-coupling regime I. S. Beloborodov,1 Ya. V. Fominov,1,2 A. V. Lopatin,1 and V. M. Vinokur1

    E-Print Network [OSTI]

    Fominov, Yakov

    Insulating state of granular superconductors in a strong-coupling regime I. S. Beloborodov,1 Ya. V-field-induced insulating state in a two-dimensional granular superconductor with relatively strong intergranular coupling the superconductor-insulator transi- tion, and a reentrant drop upon further increase of magnetic field. The magnetic

  16. Snapshot of iron response in Shewanella oneidensis by gene network reconstruction

    E-Print Network [OSTI]

    Harris, Daniel P.

    2010-01-01T23:59:59.000Z

    dissection of the Helicobacter pylori Fur regulatory circuitregulation of the Helicobacter pylori iron-cofactored

  17. Cast B2-phase iron-aluminum alloys with improved fluidity

    DOE Patents [OSTI]

    Maziasz, Philip J. (122 Clark La., Oak Ridge, TN 37830); Paris, Alan M. (P.O. Box 64, Tarrs, PA 15688); Vought, Joseph D. (124 Cove Point Rd., Rockwood, TN 37854)

    2002-01-01T23:59:59.000Z

    Systems and methods are described for iron aluminum alloys. A composition includes iron, aluminum and manganese. A method includes providing an alloy including iron, aluminum and manganese; and processing the alloy. The systems and methods provide advantages because additions of manganese to iron aluminum alloys dramatically increase the fluidity of the alloys prior to solidification during casting.

  18. Synthesis and characterization of iron-impregnated porous carbon spheres prepared by ultrasonic spray pyrolysis

    E-Print Network [OSTI]

    Suslick, Kenneth S.

    applications for iron nanoparticles include Fischer­Tropsch catalysts, oxygen reduction catalysts in fuel cells

  19. 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

    2008-01-01T23:59:59.000Z

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

  20. Time series of high resolution photospheric spectra in a quiet region of the Sun. II. Analysis of the variation of physical quantities of granular structures

    E-Print Network [OSTI]

    Puschmann, K G; Vazquez, M; Bonet, J A; Hanslmeier, A; 10.1051/0004-6361:20047193

    2012-01-01T23:59:59.000Z

    From the inversion of a time series of high resolution slit spectrograms obtained from the quiet sun, the spatial and temporal distribution of the thermodynamical quantities and the vertical flow velocity is derived as a function of logarithmic optical depth and geometrical height. Spatial coherence and phase shift analyzes between temperature and vertical velocity depict the height variation of these physical quantities for structures of different size. An average granular cell model is presented, showing the granule-intergranular lane stratification of temperature, vertical velocity, gas pressure and density as a function of logarithmic optical depth and geometrical height. Studies of a specific small and a specific large granular cell complement these results. A strong decay of the temperature fluctuations with increasing height together with a less efficient penetration of smaller cells is revealed. The T -T coherence at all granular scales is broken already at log tau =-1 or z~170 km. At the layers beyon...

  1. Decoupling of iron and phosphate in the global ocean

    E-Print Network [OSTI]

    Parekh, Payal

    2003-01-01T23:59:59.000Z

    Iron (Fe) is an essential micronutrient for marine phytoplankton often limiting phytoplankton growth due to its low concentration in the ocean and thus playing a role in modulating the ocean's biological pump. In order to ...

  2. Verification of Steelmaking Slags Iron Content Final Technical Progress Report

    SciTech Connect (OSTI)

    J.Y. Hwang

    2006-10-04T23:59:59.000Z

    The steel industry in the United States generates about 30 million tons of by-products each year, including 6 million tons of desulfurization and BOF/BOP slag. The recycling of BF (blast furnace) slag has made significant progress in past years with much of the material being utilized as construction aggregate and in cementitious applications. However, the recycling of desulfurization and BOF/BOP slags still faces many technical, economic, and environmental challenges. Previous efforts have focused on in-plant recycling of the by-products, achieving only limited success. As a result, large amounts of by-products of various qualities have been stockpiled at steel mills or disposed into landfills. After more than 50 years of stockpiling and landfilling, available mill site space has diminished and environmental constraints have increased. The prospect of conventionally landfilling of the material is a high cost option, a waste of true national resources, and an eternal material liability issue. The research effort has demonstrated that major inroads have been made in establishing the viability of recycling and reuse of the steelmaking slags. The research identified key components in the slags, developed technologies to separate the iron units and produce marketable products from the separation processes. Three products are generated from the technology developed in this research, including a high grade iron product containing about 90%Fe, a medium grade iron product containing about 60% Fe, and a low grade iron product containing less than 10% Fe. The high grade iron product contains primarily metallic iron and can be marketed as a replacement of pig iron or DRI (Direct Reduced Iron) for steel mills. The medium grade iron product contains both iron oxide and metallic iron and can be utilized as a substitute for the iron ore in the blast furnace. The low grade iron product is rich in calcium, magnesium and iron oxides and silicates. It has a sufficient lime value and can be utilized for acid mine drainage treatment. Economic analysis from this research demonstrates that the results are favorable. The strong demand and the increase of price of the DRI and pig iron in recent years are particularly beneficial to the economics. The favorable economics has brought commercial interests. ICAN Global has obtained license agreement on the technology from Michigan Tech. This right was later transferred to the Westwood Land, Inc. A demonstration pilot plant is under construction to evaluate the technology. Steel industry will benefit from the new supply of the iron units once the commercial plants are constructed. Environmental benefits to the public and the steel industry will be tremendous. Not only the old piles of the slag will be removed, but also the federal responsible abandoned mines from the old mining activities can be remediated with the favorable product generated from the process. Cost can be reduced and there will be no lime required, which can avoid the release of carbon dioxide from lime production process.

  3. 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...

  4. Iron Cycling and Redox Evolution in the Precambrian

    E-Print Network [OSTI]

    Planavsky, Noah John

    2012-01-01T23:59:59.000Z

    in a greater enrichment in the lighter Fe isotopes in theIron isotopes provide evidence that Fe enrichment in IF is2003). This enrichment in heavy Fe isotopes contrasts with

  5. In Situ Iron Oxide Emplacement for Groundwater Arsenic Remediation 

    E-Print Network [OSTI]

    Abia, Thomas Sunday

    2012-02-14T23:59:59.000Z

    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...

  6. Geologic evolution of Iron Mountain, central Mojave Desert, California

    E-Print Network [OSTI]

    Boettcher, Stefan S.; Walker, J. Douglas

    1993-04-01T23:59:59.000Z

    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 ...

  7. Iron limitation and the role of Siderophores in marine Synechococcus

    E-Print Network [OSTI]

    Rivers, Adam R. (Adam Reid)

    2009-01-01T23:59:59.000Z

    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 ...

  8. Method and system for producing metallic iron nuggets

    DOE Patents [OSTI]

    Iwasaki, Iwao; Kiesel, Richard F.; Englund, David J; Hendrickson, Dave

    2012-12-18T23:59:59.000Z

    A method and system for producing metallic iron nuggets may include providing multiple layers of agglomerates, such as briquettes, balls and extrusions, of a reducible mixture of reducing material (such as carbonaceous material) and of a reducible iron bearing material (such as iron oxide) on a hearth material layer (such as carbonaceous material) and providing a coarse overlayer of carbonaceous material over at least some of the agglomerates. Heating the agglomerates of reducible mixture to 1425.degree. C. or 1400.degree. C. or 1375.degree. C. results in formation of an intermediate product of one or more metallic iron nuggets, which may have a sulfur content of less than 0.03%, and slag, which may have less than 5% mass MgO, which may have a ratio of percent by weight sulfur in the slag over percent by weight sulfur in the metallic nuggets of at least about 12 or at least about 15.

  9. Process for removing technetium from iron and other metals

    DOE Patents [OSTI]

    Leitnaker, James M. (Kingston, TN); Trowbridge, Lee D. (Oak Ridge, TN)

    1999-01-01T23:59:59.000Z

    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.

  10. Iron and DHA in Relation to Early Cognitive Development

    E-Print Network [OSTI]

    Park, Loran Marie

    2013-05-31T23:59:59.000Z

    Iron and docosahexaenoic acid (DHA) are important nutrients for brain development. Negative effects of DHA supplementation when status of both nutrients is low have been shown on cognitive outcomes. We sought to determine ...

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

    E-Print Network [OSTI]

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

    2011-01-01T23:59:59.000Z

    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. anthropogenic iron cycles: Topics by E-print Network

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

    tion in the average odds of each feature occurring within Sandercock, Brett K. 42 Solar Cycle Variations in the Elemental Abundance of Helium and Fractionation of Iron in the...

  13. Surface modifications of iron oxide nanoparticles for biological applications

    E-Print Network [OSTI]

    Insin, Numpon

    2011-01-01T23:59:59.000Z

    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. Iron-oxide catalyzed silicon photoanode for water splitting

    E-Print Network [OSTI]

    Jun, Kimin

    2011-01-01T23:59:59.000Z

    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 ...

  15. The industrial ecology of the iron casting industry

    E-Print Network [OSTI]

    Jones, Alissa J. (Alissa Jean)

    2007-01-01T23:59:59.000Z

    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 ...

  16. Magnetism and Superconductivity Compete in Iron-based Superconductors...

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

    Magnetism and Superconductivity Compete in Iron-based Superconductors Wednesday, April 30, 2014 HTSC Figure 1 Fig. 1. Measured electronic structure of underdoped Ba1-xKxFe2As2 in...

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

    E-Print Network [OSTI]

    Powell, Douglas M. (Douglas Michael)

    2012-01-01T23:59:59.000Z

    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 ...

  18. Modernization of the iron making plant at SOLLAC FOS

    SciTech Connect (OSTI)

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

    1995-12-01T23:59:59.000Z

    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.

  19. Polymer-coated iron oxide nanoparticles for medical imaging

    E-Print Network [OSTI]

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

    2010-01-01T23:59:59.000Z

    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 ...

  20. The relationship between iron and nitrogen fixation in Trichodesmium spp.

    E-Print Network [OSTI]

    Chappell, Phoebe Dreux

    2009-01-01T23:59:59.000Z

    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 ...