National Library of Energy BETA

Sample records for ash impurities consisting

  1. Self-pumping impurity control

    DOE Patents [OSTI]

    Brooks, J.N.; Mattas, R.F.

    1983-12-21

    It is an object of the present invention to provide an apparatus for removing impurities from the plasma in a fusion reactor without an external vacuum pumping system. It is also an object of the present invention to provide an apparatus for removing the helium ash from a fusion reactor. It is another object of the present invention to provide an apparatus which removes helium ash and minimizes tritium recycling and inventory.

  2. Fluidized bed gasification ash reduction and removal process

    DOE Patents [OSTI]

    Schenone, Carl E.; Rosinski, Joseph

    1984-12-04

    In a fluidized bed gasification system an ash removal system to reduce the particulate ash to a maximum size or smaller, allow the ash to cool to a temperature lower than the gasifier and remove the ash from the gasifier system. The system consists of a crusher, a container containing level probes and a means for controlling the rotational speed of the crusher based on the level of ash within the container.

  3. Fluidized bed gasification ash reduction and removal system

    DOE Patents [OSTI]

    Schenone, Carl E.; Rosinski, Joseph

    1984-02-28

    In a fluidized bed gasification system an ash removal system to reduce the particulate ash to a maximum size or smaller, allow the ash to cool to a temperature lower than the gasifier and remove the ash from the gasifier system. The system consists of a crusher, a container containing level probes and a means for controlling the rotational speed of the crusher based on the level of ash within the container.

  4. ITER helium ash accumulation

    SciTech Connect (OSTI)

    Hogan, J.T.; Hillis, D.L.; Galambos, J.; Uckan, N.A. ); Dippel, K.H.; Finken, K.H. . Inst. fuer Plasmaphysik); Hulse, R.A.; Budny, R.V. . Plasma Physics Lab.)

    1990-01-01

    Many studies have shown the importance of the ratio {upsilon}{sub He}/{upsilon}{sub E} in determining the level of He ash accumulation in future reactor systems. Results of the first tokamak He removal experiments have been analysed, and a first estimate of the ratio {upsilon}{sub He}/{upsilon}{sub E} to be expected for future reactor systems has been made. The experiments were carried out for neutral beam heated plasmas in the TEXTOR tokamak, at KFA/Julich. Helium was injected both as a short puff and continuously, and subsequently extracted with the Advanced Limiter Test-II pump limiter. The rate at which the He density decays has been determined with absolutely calibrated charge exchange spectroscopy, and compared with theoretical models, using the Multiple Impurity Species Transport (MIST) code. An analysis of energy confinement has been made with PPPL TRANSP code, to distinguish beam from thermal confinement, especially for low density cases. The ALT-II pump limiter system is found to exhaust the He with maximum exhaust efficiency (8 pumps) of {approximately}8%. We find 1<{upsilon}{sub He}/{upsilon}{sub E}<3.3 for the database of cases analysed to date. Analysis with the ITER TETRA systems code shows that these values would be adequate to achieve the required He concentration with the present ITER divertor He extraction system.

  5. Impurity gettering in semiconductors

    DOE Patents [OSTI]

    Sopori, B.L.

    1995-06-20

    A process for impurity gettering in a semiconductor substrate or device such as a silicon substrate or device is disclosed. The process comprises hydrogenating the substrate or device at the back side thereof with sufficient intensity and for a time period sufficient to produce a damaged back side. Thereafter, the substrate or device is illuminated with electromagnetic radiation at an intensity and for a time period sufficient to cause the impurities to diffuse to the back side and alloy with a metal there present to form a contact and capture the impurities. The impurity gettering process also can function to simultaneously passivate defects within the substrate or device, with the defects likewise diffusing to the back side for simultaneous passivation. Simultaneously, substantially all hydrogen-induced damage on the back side of the substrate or device is likewise annihilated. Also taught is an alternate process comprising thermal treatment after hydrogenation of the substrate or device at a temperature of from about 500 C to about 700 C for a time period sufficient to cause the impurities to diffuse to the damaged back side thereof for subsequent capture by an alloying metal. 1 fig.

  6. Impurity gettering in semiconductors

    DOE Patents [OSTI]

    Sopori, Bhushan L.

    1995-01-01

    A process for impurity gettering in a semiconductor substrate or device such as a silicon substrate or device. The process comprises hydrogenating the substrate or device at the back side thereof with sufficient intensity and for a time period sufficient to produce a damaged back side. Thereafter, the substrate or device is illuminated with electromagnetic radiation at an intensity and for a time period sufficient to cause the impurities to diffuse to the back side and alloy with a metal there present to form a contact and capture the impurities. The impurity gettering process also can function to simultaneously passivate defects within the substrate or device, with the defects likewise diffusing to the back side for simultaneous passivation. Simultaneously, substantially all hydrogen-induced damage on the back side of the substrate or device is likewise annihilated. Also taught is an alternate process comprising thermal treatment after hydrogenation of the substrate or device at a temperature of from about 500.degree. C. to about 700.degree. C. for a time period sufficient to cause the impurities to diffuse to the damaged back side thereof for subsequent capture by an alloying metal.

  7. Dynamical impurity problems

    SciTech Connect (OSTI)

    Emery, V.J.; Kivelson, S.A.

    1993-12-31

    In the past few years there has been a resurgence of interest in dynamical impurity problems, as a result of developments in the theory of correlated electron systems. The general dynamical impurity problem is a set of conduction electrons interacting with an impurity which has internal degrees of freedom. The simplest and earliest example, the Kondo problem, has attracted interest since the mid-sixties not only because of its physical importance but also as an example of a model displaying logarithmic divergences order by order in perturbation theory. It provided one of the earliest applications of the renormalization group method, which is designed to deal with just such a situation. As we shall see, the antiferromagnetic Kondo model is controlled by a strong-coupling fixed point, and the essence of the renormalization group solution is to carry out the global renormalization numerically starting from the original (weak-coupling) Hamiltonian. In these lectures, we shall describe an alternative route in which we identify an exactly solvable model which renormalizes to the same fixed point as the original dynamical impurity problem. This approach is akin to determining the critical behavior at a second order phase transition point by solving any model in a given universality class.

  8. Activation of fly ash

    DOE Patents [OSTI]

    Corbin, D.R.; Velenyi, L.J.; Pepera, M.A.; Dolhyj, S.R.

    1986-08-19

    Fly ash is activated by heating a screened magnetic fraction of the ash in a steam atmosphere and then reducing, oxidizing and again reducing the hydrothermally treated fraction. The activated fly ash can be used as a carbon monoxide disproportionating catalyst useful in the production of hydrogen and methane.

  9. Activation of fly ash

    DOE Patents [OSTI]

    Corbin, David R.; Velenyi, Louis J.; Pepera, Marc A.; Dolhyj, Serge R.

    1986-01-01

    Fly ash is activated by heating a screened magnetic fraction of the ash in a steam atmosphere and then reducing, oxidizing and again reducing the hydrothermally treated fraction. The activated fly ash can be used as a carbon monoxide disproportionating catalyst useful in the production of hydrogen and methane.

  10. Fly ash carbon passivation

    DOE Patents [OSTI]

    La Count, Robert B; Baltrus, John P; Kern, Douglas G

    2013-05-14

    A thermal method to passivate the carbon and/or other components in fly ash significantly decreases adsorption. The passivated carbon remains in the fly ash. Heating the fly ash to about 500 and 800 degrees C. under inert gas conditions sharply decreases the amount of surfactant adsorbed by the fly ash recovered after thermal treatment despite the fact that the carbon content remains in the fly ash. Using oxygen and inert gas mixtures, the present invention shows that a thermal treatment to about 500 degrees C. also sharply decreases the surfactant adsorption of the recovered fly ash even though most of the carbon remains intact. Also, thermal treatment to about 800 degrees C. under these same oxidative conditions shows a sharp decrease in surfactant adsorption of the recovered fly ash due to the fact that the carbon has been removed. This experiment simulates the various "carbon burnout" methods and is not a claim in this method. The present invention provides a thermal method of deactivating high carbon fly ash toward adsorption of AEAs while retaining the fly ash carbon. The fly ash can be used, for example, as a partial Portland cement replacement in air-entrained concrete, in conductive and other concretes, and for other applications.

  11. Effect of fuel properties on the bottom ash generation rate by a laboratory fluidized bed combustor

    SciTech Connect (OSTI)

    Rozelle, P.L.; Pisupati, S.V.; Scaroni, A.W.

    2007-06-15

    The range of fuels that can be accommodated by an FBC boiler system is affected by the ability of the fuel, sorbent, and ash-handling equipment to move the required solids through the boiler. Of specific interest is the bottom ash handling equipment, which must have sufficient capacity to remove ash from the system in order to maintain a constant bed inventory level, and must have sufficient capability to cool the ash well below the bed temperature. Quantification of a fuel's bottom ash removal requirements can be useful for plant design. The effect of fuel properties on the rate of bottom ash production in a laboratory FBC test system was examined. The work used coal products ranging in ash content from 20 to 40+ wt. %. The system's classification of solids by particle size into flyash and bottom ash was characterized using a partition curve. Fuel fractions in the size range characteristic of bottom ash were further analyzed for distributions of ash content with respect to specific gravity, using float sink tests. The fuel fractions were then ashed in a fixed bed. In each case, the highest ash content fraction produced ash with the coarsest size consist (characteristic of bottom ash). The lower ash content fractions were found to produce ash in the size range characteristic of flyash, suggesting that the high ash content fractions were largely responsible for the production of bottom ash. The contributions of the specific gravity fractions to the composite ash in the fuels were quantified. The fuels were fired in the laboratory test system. Fuels with higher amounts of high specific gravity particles, in the size ranges characteristic of bottom ash, were found to produce more bottom ash, indicating the potential utility of float sink methods in the prediction of bottom ash removal requirements.

  12. Fundamental Study of Low NOx Combustion Fly Ash Utilization

    SciTech Connect (OSTI)

    E. M. Suubert; I. Kuloats; K. Smith; N. Sabanegh; R.H. Hurt; W. D. Lilly; Y. M. Gao

    1997-05-01

    This study is principally concerned with characterizing the organic part of coal combustion fly ashes. High carbon fly ashes are becoming more common as by-products of low-NOx combustion technology, and there is need to learn more about this fraction of the fly ash. The project team consists of two universities, Brown and Princeton, and an electrical utility, New England Power. A sample suite of over forty fly ashes has been gathered from utilities across the United States, and includes ashes from a coals ranging in rank from bituminous to lignite. The characterizations of these ashes include standard tests (LOI, Foam Index), as well as more detailed characterizations of their surface areas, porosity, extractability and adsorption behavior. The ultimate goal is, by better characterizing the material, to enable broadening the range of applications for coal fly ash re-use beyond the current main market as a pozzolanic agent for concretes. The potential for high carbon-content fly ashes to substitute for activated carbons is receiving particular attention. The work performed to date has already revealed how very different the surfaces of different ashes produced by the same utility can be, with respect to polarity of the residual carbon. This can help explain the large variations in acceptability of these ashes as concrete additives.

  13. Fundamental Study of Low-Nox Combustion Fly Ash Utilization

    SciTech Connect (OSTI)

    E. M. Suuberg; I. Kuloats; K. Smith; N. Sabanegh; R. H. Hurt; W. D. Lilly; Y. M. Gao

    1997-11-01

    This study is principally concerned with characterizing the organic part of coal combustion fly ashes. High carbon fly ashes are becoming more common as by-products of low-NOx combustion technology, and there is need to learn more about this fraction of the fly ash. The project team consists of two universities, Brown and Princeton, and an electrical utility, New England Power. A sample suite of over forty fly ashes has been gathered from utilities across the United States, and includes ashes from a coals ranging in rank from bituminous to lignite. The characterizations of these ashes include standard tests (LOI, Foam Index), as well as more detailed characterizations of their surface areas, porosity, extractability and adsorption behavior. The ultimate goal is, by better characterizing the material, to enable broadening the range of applications for coal fly ash re-use beyond the current main market as a pozzolanic agent for concretes. The potential for high carbon-content fly ashes to substitute for activated carbons is receiving particular attention. The work performed to date has already revealed how very different the surfaces of different ashes produced by the same utility can be, with respect to polarity of the residual carbon. This can help explain the large variations in acceptability of these ashes as concrete additives.

  14. Quantitative ion-exchange separation of plutonium from impurities

    SciTech Connect (OSTI)

    Pietri, C.E.; Freeman, B.P.; Weiss, J.R.

    1981-09-01

    The methods used at the New Brunswick Laboratory for the quantitative ion exchange separation of plutonium from impurities prior to plutonium assay are described. Other ion exchange separation procedures for impurity determination and for isotopic abundance measurements are given. The primary technique used consists of sorption of plutonium(IV) in 8N HNO/sub 3/ on Dowex-1 anion exchange resin and elution of the purified plutonium with 0.3N HCl-0.01N HF. Other methods consist of the anion exchange separation of plutonium(IV) in 12N HCl and the cation exchange separation of plutonium(III) in 0.2 N HNO/sub 3/. The application of these procedures to the subsequent assay of plutonium, isotopic analysis, and impurity determination is described.

  15. Steady-state tokamak reactor with non-divertor impurity control: STARFIRE

    SciTech Connect (OSTI)

    Baker, C.C.

    1980-01-01

    STARFIRE is a conceptual design study of a commercial tokamak fusion electric power plant. Particular emphasis has been placed on simplifying the reactor concept by developing design concepts to produce a steady-state tokamak with non-divertor impurity control and helium ash removal. The concepts of plasma current drive using lower hybrid rf waves and a limiter/vacuum system for reactor applications are described.

  16. Engineering Model for Ash Formation

    Energy Science and Technology Software Center (OSTI)

    1994-12-02

    Ash deposition is controlled by the impaction and sticking of individual ash particles to heat transfer surfaces. Prediction of deposition therefore requires that the important factors in this process be predictable from coal and operational parameters. Coal combustion, boiler heat transfer, ash formation, ash particle aerodynamic, and ash particle sticking models are all essential steps in this process. The model described herein addresses the prediction of ash particle size and composition distributions based upon combustionmore » conditions and coal parameters. Key features of the model include a mineral redistribution routine to invert CCSEM mineralogical data, and a mineral interaction routine that simulates the conversion of mineral matter into ash during coal burning and yields ash particle size and composition distributions.« less

  17. Impurity gettering in silicon using cavities formed by helium implantation and annealing

    DOE Patents [OSTI]

    Myers, S.M. Jr.; Bishop, D.M.; Follstaedt, D.M.

    1998-11-24

    Impurity gettering in silicon wafers is achieved by a new process consisting of helium ion implantation followed by annealing. This treatment creates cavities whose internal surfaces are highly chemically reactive due to the presence of numerous silicon dangling bonds. For two representative transition-metal impurities, copper and nickel, the binding energies at cavities were demonstrated to be larger than the binding energies in precipitates of metal silicide, which constitutes the basis of most current impurity gettering. As a result the residual concentration of such impurities after cavity gettering is smaller by several orders of magnitude than after precipitation gettering. Additionally, cavity gettering is effective regardless of the starting impurity concentration in the wafer, whereas precipitation gettering ceases when the impurity concentration reaches a characteristic solubility determined by the equilibrium phase diagram of the silicon-metal system. The strong cavity gettering was shown to induce dissolution of metal-silicide particles from the opposite side of a wafer. 4 figs.

  18. Impurity gettering in silicon using cavities formed by helium implantation and annealing

    DOE Patents [OSTI]

    Myers, Jr., Samuel M.; Bishop, Dawn M.; Follstaedt, David M.

    1998-01-01

    Impurity gettering in silicon wafers is achieved by a new process consisting of helium ion implantation followed by annealing. This treatment creates cavities whose internal surfaces are highly chemically reactive due to the presence of numerous silicon dangling bonds. For two representative transition-metal impurities, copper and nickel, the binding energies at cavities were demonstrated to be larger than the binding energies in precipitates of metal silicide, which constitutes the basis of most current impurity gettering. As a result the residual concentration of such impurities after cavity gettering is smaller by several orders of magnitude than after precipitation gettering. Additionally, cavity gettering is effective regardless of the starting impurity concentration in the wafer, whereas precipitation gettering ceases when the impurity concentration reaches a characteristic solubility determined by the equilibrium phase diagram of the silicon-metal system. The strong cavity gettering was shown to induce dissolution of metal-silicide particles from the opposite side of a wafer.

  19. Control of impurities in toroidal plasma devices

    DOE Patents [OSTI]

    Ohkawa, Tihiro (La Jolla, CA)

    1980-01-01

    A method and apparatus for plasma impurity control in closed flux plasma systems such as Tokamak reactors is disclosed. Local axisymmetrical injection of hydrogen gas is employed to reverse the normally inward flow of impurities into the plasma.

  20. Screening technology reduces ash in spiral circuits

    SciTech Connect (OSTI)

    Brodzik, P.

    2007-05-15

    In 2006, the James River Coal Co. selected the Stack Sizer to remove the minus 100 mesh high ash clay fraction from the clean coal spiral product circuits at the McCoy-Elkhorn Bevins Branch prep plant and at the Blue Diamond Leatherwood prep plant in Kentucky. The Stack Sizer is a multi-deck, high-frequency vibrating screen capable of separations as fine as 75 microns when fitted with Derrick Corp.'s patented high open area urethane screen panels. Full-scale lab tests and more than 10 months of continuous production have confirmed that the Stack Sizer fitted with Derrick 100 micron urethane screen panels consistently produces a clean coal fraction that ranges from 8 to 10% ash. Currently, each five-deck Stack Sizer operating at the Bevins Branch and Leatherwood prep plants is producing approximately 33 tons per hour of clean coal containing about 9% ash. This represents a clean coal yield of about 75% and an ash reduction of about 11% from the feed slurry. 3 figs. 2 tabs.

  1. Modeling volcanic ash dispersal

    ScienceCinema (OSTI)

    None

    2011-10-06

    Explosive volcanic eruptions inject into the atmosphere large amounts of volcanic material (ash, blocks and lapilli). Blocks and larger lapilli follow ballistic and non-ballistic trajectories and fall rapidly close to the volcano. In contrast, very fine ashes can remain entrapped in the atmosphere for months to years, and may affect the global climate in the case of large eruptions. Particles having sizes between these two end-members remain airborne from hours to days and can cover wide areas downwind. Such volcanic fallout entails a serious threat to aircraft safety and can create many undesirable effects to the communities located around the volcano. The assessment of volcanic fallout hazard is an important scientific, economic, and political issue, especially in densely populated areas. From a scientific point of view, considerable progress has been made during the last two decades through the use of increasingly powerful computational models and capabilities. Nowadays, models are used to quantify hazard scenarios and/or to give short-term forecasts during emergency situations. This talk will be focused on the main aspects related to modeling volcanic ash dispersal and fallout with application to the well known problem created by the Eyjafjöll volcano in Iceland. Moreover, a short description of the main volcanic monitoring techniques is presented.

  2. Self-pumping impurity control

    DOE Patents [OSTI]

    Brooks, Jeffrey N.; Mattas, Richard F.

    1991-01-01

    Apparatus for removing the helium ash from a fusion reactor having a D-T plasma comprises a helium trapping site within the reactor plasma confinement device, said trapping site being formed of a trapping material having negligible helium solubility and relatively high hydrogen solubility; and means for depositing said trapping material on said site at a rate sufficient to prevent saturation of helium trapping.

  3. Gaseous trace impurity analyzer and method

    DOE Patents [OSTI]

    Edwards, Jr., David (Bellport, NY); Schneider, William (Setauket, NY)

    1980-01-01

    Simple apparatus for analyzing trace impurities in a gas, such as helium or hydrogen, comprises means for drawing a measured volume of the gas as sample into a heated zone. A segregable portion of the zone is then chilled to condense trace impurities in the gas in the chilled portion. The gas sample is evacuated from the heated zone including the chilled portion. Finally, the chilled portion is warmed to vaporize the condensed impurities in the order of their boiling points. As the temperature of the chilled portion rises, pressure will develop in the evacuated, heated zone by the vaporization of an impurity. The temperature at which the pressure increase occurs identifies that impurity and the pressure increase attained until the vaporization of the next impurity causes a further pressure increase is a measure of the quantity of the preceding impurity.

  4. Impurity-induced divertor plasma oscillations

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

    Smirnov, R. D.; Kukushkin, A. S.; Krasheninnikov, S. I.; Pigarov, A. Yu.; Rognlien, T. D.

    2016-01-07

    Two different oscillatory plasma regimes induced by seeding the plasma with high- and low-Z impurities are found for ITER-like divertor plasmas, using computer modeling with the DUSTT/UEDGE and SOLPS4.3 plasma-impurity transport codes. The oscillations are characterized by significant variations of the impurity-radiated power and of the peak heat load on the divertor targets. Qualitative analysis of the divertor plasma oscillations reveals different mechanisms driving the oscillations in the cases of high- and low-Z impurity seeding. The oscillations caused by the high-Z impurities are excited near the X-point by an impurity-related instability of the radiation-condensation type, accompanied by parallel impurity ionmore » transport affected by the thermal and plasma friction forces. The driving mechanism of the oscillations induced by the low-Z impurities is related to the cross-field transport of the impurity atoms, causing alteration between the high and low plasma temperature regimes in the plasma recycling region near the divertor targets. As a result, the implications of the impurity-induced plasma oscillations for divertor operation in the next generation tokamaks are also discussed.« less

  5. Distribution of arsenic and mercury in lime spray dryer ash

    SciTech Connect (OSTI)

    Panuwat Taerakul; Ping Sun; Danold W. Golightly; Harold W. Walker; Linda K. Weavers

    2006-08-15

    The partitioning of As and Hg in various components of lime spray dryer (LSD) ash samples from a coal-fired boiler was characterized to better understand the form and fate of these elements in flue gas desulfurization byproducts. LSD ash samples, collected from the McCracken Power Plant on the Ohio State University campus, were separated by a 140-mesh (106 {mu}m) sieve into two fractions: a fly-ash-/unburned-carbon-enriched fraction (> 106 {mu}m) and a calcium-enriched fraction (< 106 {mu}m). Unburned carbon and fly ash in the material > 106 {mu}m were subsequently separated by density using a lithium heteropolytungstate solution. The concentrations of As and Hg were significant in all fractions. The level of As was consistently greater in the calcium-enriched fraction, while Hg was evenly distributed in all components of LSD ash. Specific surface area was an important factor controlling the distribution of Hg in the different components of LSD ash, but not for As. Comparing the LSD ash data to samples collected from the economizer suggests that As was effectively captured by fly ash at 600{sup o}C, while Hg was not. Leaching tests demonstrated that As and Hg were more stable in the calcium-enriched fraction than in the fly-ash- or carbon-enriched fractions, potentially because of the greater pH of the leachate and subsequently greater stability of small amounts of calcium solids containing trace elements in these fractions. 37 refs., 8 figs., 2 tabs.

  6. Optical properties of fly ash. Volume 2, Final report

    SciTech Connect (OSTI)

    Self, S.A.

    1994-12-01

    Research performed under this contract was divided into four tasks under the following headings: Task 1, Characterization of fly ash; Task 2, Measurements of the optical constants of slags; Task 3, Calculations of the radiant properties of fly ash dispersions; and Task 4, Measurements of the radiant properties of fly ash dispersions. Tasks 1 and 4 constituted the Ph.D. research topic of Sarbajit Ghosal, while Tasks 2 and 3 constituted the Ph.D. research topic of Jon Ebert. Together their doctoral dissertations give a complete account of the work performed. This final report, issued in two volumes consists of an executive summary of the whole program followed by the dissertation of Ghosal and Ebert. Volume 2 contains the dissertation of Ebert which covers the measurements of the optical constants of slags, and calculations of the radiant properties of fly ash dispersions. A list of publications and conference presentations resulting from the work is also included.

  7. Fly ash quality and utilization

    SciTech Connect (OSTI)

    Barta, L.E.; Lachner, L.; Wenzel, G.B.; Beer, M.J.

    1995-12-01

    The quality of fly ash is of considerable importance to fly ash utilizers. The fly ash puzzolanic activity is one of the most important properties that determines the role of fly ash as a binding agent in the cementing process. The puzzolanic activity, however is a function of fly ash particle size and chemical composition. These parameters are closely related to the process of fly ash formation in pulverized coal fired furnaces. In turn, it is essential to understand the transformation of mineral matter during coal combustion. Due to the particle-to-particle variation of coal properties and the random coalescence of mineral particles, the properties of fly ash particles e.g. size, SiO{sub 2} content, viscosity can change considerably from particle to particle. These variations can be described by the use of the probability theory. Since the mean values of these randomly changing parameters are not sufficient to describe the behavior of individual fly ash particles during the formation of concrete, therefore it is necessary to investigate the distribution of these variables. Examples of these variations were examined by the Computer Controlled Scanning Electron Microscopy (CCSEM) for particle size and chemical composition for Texas lignite and Eagel Butte mineral matter and fly ash. The effect of combustion on the variations of these properties for both the fly ash and mineral matter were studied by using a laminar flow reactor. It is shown in our paper, that there are significant variations (about 40-50% around the mean values) of the above-listed properties for both coal samples. By comparing the particle size and chemical composition distributions of the mineral matter and fly ash, it was possible to conclude that for the Texas lignite mineral matter, the combustion did not effect significantly the distribution of these properties, however, for the Eagel Butte coal the combustion had a major impact on these mineral matter parameters.

  8. Impact of Biodiesel Impurities on the Performance and Durability of DOC, DPF and SCR Technologies: Preprint

    SciTech Connect (OSTI)

    Williams, A.; McCormick, R.; Luecke, J.; Brezny, R.; Geisselmann, A.; Voss, K.; Hallstrom, K.; Leustek, M.; Parsons, J.; Abi-Akar, H.

    2011-04-01

    An accelerated durability test method determined the potential impact of biodiesel ash impurities, including engine testing with multiple diesel particulate filter substrate types, as well as diesel oxidation catalyst and selective catalyst reduction catalysts. The results showed no significant degradation in the thermo-mechanical properties of a DPF after exposure to 150,000-mile equivalent biodiesel ash and thermal aging. However, exposure to 435,000-mile equivalent aging resulted in a 69% decrease in thermal shock resistance. A decrease in DOC activity was seen after exposure to 150,000-mile equivalent aging, resulting in higher hydrocarbon slip and a reduction in NO2 formation. The SCR catalyst experienced a slight loss in activity after exposure to 435,000-mile equivalent aging. The SCR catalyst, placed downstream of the DPF and exposed to B20 exhaust suffered a 5% reduction in overall NOx conversion activity over the HDDT test cycle. It is estimated that the additional ash from 150,000 miles of biodiesel use would also result in a moderate increases in exhaust backpressure for a DPF. The results of this study suggest that long-term operation with B20 at the current specification limits for alkali and alkaline earth metal impurities will adversely impact the performance of DOC, DPF and SCR systems.

  9. Impurity-induced moments in underdoped cuprates

    SciTech Connect (OSTI)

    Khaliullin, G.; Kilian, R.; Krivenko, S.; Fulde, P.

    1997-11-01

    We examine the effect of a nonmagnetic impurity in a two-dimensional spin liquid in the spin-gap phase, employing a drone-fermion representation of spin-1/2 operators. The properties of the local moment induced in the vicinity of the impurity are investigated and an expression for the nuclear-magnetic-resonance Knight shift is derived, which we compare with experimental results. Introducing a second impurity into the spin liquid an antiferromagnetic interaction between the moments is found when the two impurities are located on different sublattices. The presence of many impurities leads to a screening of this interaction as is shown by means of a coherent-potential approximation. Further, the Kondo screening of an impurity-induced local spin by charge carriers is discussed. {copyright} {ital 1997} {ital The American Physical Society}

  10. Incineration and incinerator ash processing

    SciTech Connect (OSTI)

    Blum, T.W.

    1991-01-01

    Parallel small-scale studies on the dissolution and anion exchange recovery of plutonium from Rocky Flats Plant incinerator ash were conducted at the Los Alamos National Laboratory and at the Rocky Flats Plant. Results from these two studies are discussed in context with incinerator design considerations that might help to mitigate ash processing related problems. 11 refs., 1 fig., 1 tab.

  11. Method for detecting trace impurities in gases

    DOE Patents [OSTI]

    Freund, Samuel M.; Maier, II, William B.; Holland, Redus F.; Beattie, Willard H.

    1981-01-01

    A technique for considerably improving the sensitivity and specificity of infrared spectrometry as applied to quantitative determination of trace impurities in various carrier or solvent gases is presented. A gas to be examined for impurities is liquefied and infrared absorption spectra of the liquid are obtained. Spectral simplification and number densities of impurities in the optical path are substantially higher than are obtainable in similar gas-phase analyses. Carbon dioxide impurity (.about.2 ppm) present in commercial Xe and ppm levels of Freon 12 and vinyl chloride added to liquefied air are used to illustrate the method.

  12. Method for detecting trace impurities in gases

    DOE Patents [OSTI]

    Freund, S.M.; Maier, W.B. II; Holland, R.F.; Beattie, W.H.

    A technique for considerably improving the sensitivity and specificity of infrared spectrometry as applied to quantitative determination of trace impurities in various carrier or solvent gases is presented. A gas to be examined for impurities is liquefied and infrared absorption spectra of the liquid are obtained. Spectral simplification and number densities of impurities in the optical path are substantially higher than are obtainable in similar gas-phase analyses. Carbon dioxide impurity (approx. 2 ppM) present in commercial Xe and ppM levels of Freon 12 and vinyl chloride added to liquefied air are used to illustrate the method.

  13. Landfilling ash/sludge mixtures

    SciTech Connect (OSTI)

    Benoit, J.; Eighmy, T.T.; Crannell, B.S.

    1999-10-01

    The geotechnical properties of a mixture of municipal solid waste incinerator bottom ash and municipal wastewater treatment plant sludge was investigated for a proposed ash/sludge secure landfill. The components as well as mixtures ranging from 10:1 to 5:1 (ash:sludge, by volume) were evaluated, where appropriate, for a number of geotechnical index and mechanical properties including particle size, water content, specific gravity, density-moisture relationships, shear strength, and compressibility. The results from a compactibility study and stability analysis of the proposed landfill were used to help approve a landfill codisposal concept; a full-scale facility was constructed and is currently operating successfully.

  14. Impact of Biodiesel Impurities on the Performance and Durability of DOC, DPF and SCR Technologies

    SciTech Connect (OSTI)

    Williams, A.; McCormick, R.; Luecke, J.; Brezny, R.; Geisselmann, A.; Voss, K.; Hallstrom, K.; Leustek, M.; Parsons, J.; Abi-Akar, H.

    2011-06-01

    It is estimated that operating continuously on a B20 fuel containing the current allowable ASTM specification limits for metal impurities in biodiesel could result in a doubling of ash exposure relative to lube-oil derived ash. The purpose of this study was to determine if a fuel containing metals at the ASTM limits could cause adverse impacts on the performance and durability of diesel emission control systems. An accelerated durability test method was developed to determine the potential impact of these biodiesel impurities. The test program included engine testing with multiple DPF substrate types as well as DOC and SCR catalysts. The results showed no significant degradation in the thermo-mechanical properties of cordierite, aluminum titanate, or silicon carbide DPFs after exposure to 150,000 mile equivalent biodiesel ash and thermal aging. However, exposure of a cordierite DPF to 435,000 mile equivalent aging resulted in a 69% decrease in the thermal shock resistance parameter. It is estimated that the additional ash from 150,000 miles of biodiesel use would also result in a moderate increases in exhaust backpressure for a DPF. A decrease in DOC activity was seen after exposure to 150,000 mile equivalent aging, resulting in higher HC slip and a reduction in NO{sub 2} formation. The metal-zeolite SCR catalyst experienced a slight loss in activity after exposure to 435,000 mile equivalent aging. This catalyst, placed downstream of the DPF, showed a 5% reduction in overall NOx conversion activity over the HDDT test cycle.

  15. Accurate Detection of Impurities in Hydrogen Fuel at Lower Cost...

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

    Accurate Detection of Impurities in Hydrogen Fuel at Lower Cost Technology available for licensing: Two alternative strategies for detecting impurities in the hydrogen used in fuel...

  16. Multichannel Kondo Impurity Dynamics in a Majorana Device (Journal...

    Office of Scientific and Technical Information (OSTI)

    Multichannel Kondo Impurity Dynamics in a Majorana Device Title: Multichannel Kondo Impurity Dynamics in a Majorana Device Authors: Altland, A. ; Bri, B. ; Egger, R. ; Tsvelik, ...

  17. Impurity states in multiband s -wave superconductors: Analysis...

    Office of Scientific and Technical Information (OSTI)

    Impurity states in multiband s -wave superconductors: Analysis of iron pnictides Citation Details In-Document Search Title: Impurity states in multiband s -wave superconductors:...

  18. Effects of Impurities on Fuel Cell Performance and Durability...

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

    clemson.pdf More Documents & Publications Effects of Impurities on Fuel Cell Performance and Durability Effects of Impurities on Fuel Cell Performance and Durability Effects of ...

  19. Effects of Impurities on Fuel Cell Performance and Durability...

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

    More Documents & Publications Effects of Impurities on Fuel Cell Performance and Durability Effects of Impurities on Fuel Cell Performance and Durability Highly Dispersed Alloy ...

  20. Effects of Impurities on Fuel Cell Performance and Durability...

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

    lanl.pdf More Documents & Publications Effects of Impurities on Fuel Cell Performance and Durability Effects of Impurities on Fuel Cell Performance and Durability Advanced Cathode ...

  1. Long duration ash probe

    DOE Patents [OSTI]

    Hurley, J.P.; McCollor, D.P.; Selle, S.J.

    1994-07-26

    A long duration ash probe includes a pressure shell connected to a port in a combustor with a sample coupon mounted on a retractable carriage so as to retract the sample coupon within the pressure shell during soot blowing operation of the combustor. A valve mounted at the forward end of the pressure shell is selectively closeable to seal the sample coupon within the shell, and a heating element in the shell is operable to maintain the desired temperature of the sample coupon while retracted within the shell. The carriage is operably mounted on a pair of rails within the shell for longitudinal movement within the shell. A hollow carrier tube connects the hollow cylindrical sample coupon to the carriage, and extends through the carriage and out the rearward end thereof. Air lines are connected to the rearward end of the carrier tube and are operable to permit coolant to pass through the air lines and thence through the carrier tube to the sample coupon so as to cool the sample coupon. 8 figs.

  2. Long duration ash probe

    DOE Patents [OSTI]

    Hurley, John P.; McCollor, Don P.; Selle, Stanley J.

    1994-01-01

    A long duration ash probe includes a pressure shell connected to a port in a combustor with a sample coupon mounted on a retractable carriage so as to retract the sample coupon within the pressure shell during sootblowing operation of the combustor. A valve mounted at the forward end of the pressure shell is selectively closeable to seal the sample coupon within the shell, and a heating element in the shell is operable to maintain the desired temperature of the sample coupon while retracted within the shell. The carriage is operably mounted on a pair of rails within the shell for longitudinal movement within the shell. A hollow carrier tube connects the hollow cylindrical sample coupon to the carriage, and extends through the carriage and out the rearward end thereof. Air lines are connected to the rearward end of the carrier tube and are operable to permit coolant to pass through the air lines and thence through the carrier tube to the sample coupon so as to cool the sample coupon.

  3. Leaching of Mixtures of Biochar and Fly Ash

    SciTech Connect (OSTI)

    Palumbo, Anthony Vito; Porat, Iris; Phillips, Jana Randolph; Amonette, J. E.; Drake, Meghan M; Brown, Steven D; Schadt, Christopher Warren

    2009-01-01

    Increasing atmospheric levels of greenhouse gases, especially CO2, and their effects on global temperature have led to interest in the possibility of carbon storage in terrestrial environments.2, 5, 6 Both the residual char from biomass pyrolysis7-9, 12 (biochar) and fly ash from coal combustion1, 13, 14 have the potential to significantly expand terrestrial sequestration options. Both biochar and fly ash also have potentially beneficial effects on soil properties. Fly ash has been shown to increase porosity, water-holding capacity, pH, conductivity, and dissolved SO42-, CO32-, Cl- and basic cations.10, 11, 16 Adding biochar to soil generally raises pH, increases total nitrogen and total phosphorous, encourages greater root development, improves cation exchange capacity and reduces available aluminum.3, 17 Combinations of these benefits likely lead to the observed increased yields for crops including corn and sugarcane.17 with biochar addition to soil. In addition, it has been found that soils with added biochar emit lower amounts of other greenhouse gases (methane and nitrous oxide) 8, 17 than do unammended soils. Biochar and fly ash amendments may be useful in promoting terrestrial carbon sequestration on currently underutilized and degraded lands. For example, about 1% of the US surface lands consist of previously mined lands or highway rights-of-way.18 Poorly managed lands could count for another 15% of US area. Biochar and fly ash amendments could increase productivity of these lands and increase carbon storage in the soil Previous results showed minimal leaching of organic carbon and metals from a variety of fly ashes.15 Here, we are examining the properties of mixtures of biochar, fly ash, and soil and evaluating leaching of organic carbon and metals from the mixtures.

  4. Numerical Studies of Impurities in Fusion Plasmas

    DOE R&D Accomplishments [OSTI]

    Hulse, R. A.

    1982-09-01

    The coupled partial differential equations used to describe the behavior of impurity ions in magnetically confined controlled fusion plasmas require numerical solution for cases of practical interest. Computer codes developed for impurity modeling at the Princeton Plasma Physics Laboratory are used as examples of the types of codes employed for this purpose. These codes solve for the impurity ionization state densities and associated radiation rates using atomic physics appropriate for these low-density, high-temperature plasmas. The simpler codes solve local equations in zero spatial dimensions while more complex cases require codes which explicitly include transport of the impurity ions simultaneously with the atomic processes of ionization and recombination. Typical applications are discussed and computational results are presented for selected cases of interest.

  5. Fly ash chemical classification based on lime

    SciTech Connect (OSTI)

    Fox, J.

    2007-07-01

    Typically, total lime content (CaO) of fly ash is shown in fly ash reports, but its significance is not addressed in US specifications. For certain applications a low lime ash is preferred. When a class C fly ash must be cementitious, lime content above 20% is required. A ternary S-A-C phase diagram pilot is given showing the location of fly ash compositions by coal rank and source in North America. Fly ashes from subbituminous coal from the Powder River Basin usually contain sufficient lime to be cementitious but blending with other coals may result in calcium being present in phases other than tricalcium aluminate. 9 refs., 1 fig.

  6. Lazy arc consistency

    SciTech Connect (OSTI)

    Schiex, T.; Gaspin, C.; Regin, J.C.; Verfaillie, G.

    1996-12-31

    Arc consistency filtering is widely used in the framework of binary constraint satisfaction problems: with a low complexity, inconsistency may be detected and domains are filtered. In this paper, we show that when detecting inconsistency is the objective, a systematic domain filtering is useless and a lazy approach is more adequate. Whereas usual arc consistency algorithms produce the maximum arc consistent sub-domain, when it exists, we propose a method, called LAC{tau}, which only looks for any arc consistent sub-domain. The algorithm is then extended to provide the additional service of locating one variable with a minimum domain cardinality in the maximum arc consistent sub-domain, without necessarily computing all domain sizes. Finally, we compare traditional AC enforcing and lazy AC enforcing using several benchmark problems, both randomly generated CSP and real life problems.

  7. Overview of SOFC Anode Interactions with Coal Gas Impurities

    SciTech Connect (OSTI)

    Marina, Olga A.; Pederson, Larry R.; Gemmen, Randall; Gerdes, Kirk; Finklea, Harry; Celik, Ismail B.

    2009-08-11

    Efficiencies greater than 50 percent (higher heating value) have been projected for solid oxide fuel cell (SOFC) systems fueled with gasified coal, even with carbon sequestration. Multiple minor and trace components are present in coal that could affect fuel cell performance, however, which vary widely depending on coal origin and type. Minor and trace components have been classified into three groups: elements with low volatility that are likely to remain in the ash, elements that will partition between solid and gas phases, and highly volatile elements that are unlikely to condense. Those in the second group are of most concern. In the following, an overview of the results of SOFC anode interactions with phosphorus, arsenic, selenium, sulfur, antimony, and hydrogen chloride as single contaminants or in combinations is discussed. Tests were performed using both anode- and electrolyte-supported cells in synthetic coal gas. The ultimate purpose of this work is to establish maximum permissible concentrations for impurities in coal gas, to aid in the selection of appropriate coal gas clean-up technologies.

  8. Speciation of Selenium, Arsenic, and Zinc in Class C Fly Ash

    SciTech Connect (OSTI)

    Luo, Yun; Giammar, Daniel E.; Huhmann, Brittany L.; Catalano, Jeffrey G.

    2011-11-17

    A major environmental concern associated with coal fly ash is the mobilization of trace elements that may contaminate water. To better evaluate proper use of fly ash, determine appropriate disposal methods, and monitor postdisposal conditions, it is important to understand the speciation of trace elements in fly ash and their possible environmental impact. The speciation of selenium, arsenic, and zinc was determined in five representative Class C fly ash samples from combustion of sub-bituminous Powder River Basin coal using synchrotron-based X-ray absorption spectroscopy to provide an improved understanding of the mechanisms of trace element association with the fly ash. Selenium in all fly ash samples occurs predominantly as Se(IV), with the exception of one sample, in which there was a minor amount of Se(0). Se(0) is likely associated with the high content of unburned coal in the sample. Arsenic exists in the fly ash as a single phase most consistent with calcium pyroarsenate. In contrast, zinc occurs as two distinct species in the silicate glass matrix of the fly ash. This work demonstrates that residual carbon in fly ash may reduce potential Se mobility in the environment by retaining it as less soluble elemental Se instead of Se(IV). Further, this work suggests that As and Zn in Class C fly ash will display substantially different release and mobilization behaviors in aquatic environments. While As release will primarily depend upon the dissolution and hydrolysis of calcium pyroarsenate, Zn release will be controlled by the dissolution of alkaline aluminosilicate glass in the ash.

  9. Gasification of high ash, high ash fusion temperature bituminous coals

    DOE Patents [OSTI]

    Liu, Guohai; Vimalchand, Pannalal; Peng, WanWang

    2015-11-13

    This invention relates to gasification of high ash bituminous coals that have high ash fusion temperatures. The ash content can be in 15 to 45 weight percent range and ash fusion temperatures can be in 1150.degree. C. to 1500.degree. C. range as well as in excess of 1500.degree. C. In a preferred embodiment, such coals are dealt with a two stage gasification process--a relatively low temperature primary gasification step in a circulating fluidized bed transport gasifier followed by a high temperature partial oxidation step of residual char carbon and small quantities of tar. The system to process such coals further includes an internally circulating fluidized bed to effectively cool the high temperature syngas with the aid of an inert media and without the syngas contacting the heat transfer surfaces. A cyclone downstream of the syngas cooler, operating at relatively low temperatures, effectively reduces loading to a dust filtration unit. Nearly dust- and tar-free syngas for chemicals production or power generation and with over 90%, and preferably over about 98%, overall carbon conversion can be achieved with the preferred process, apparatus and methods outlined in this invention.

  10. Rising from the ashes: Coal ash in recycling and construction

    SciTech Connect (OSTI)

    Naquin, D.

    1998-02-01

    Beneficial Ash Management (BAM, Clearfield, Pa.) has won an environmental award for its use of ash and other waste to fight acid mine drainage. The company`s workers take various waste materials, mainly fly ash from coal-burning plants, to make a cement-like material or grouting, says Ernest Roselli, BAM president. The grouting covers the soil, which helps prevent water from contacting materials. This, in turn, helps control chemical reactions, reducing or eliminating formation of acid mine drainage. The company is restoring the 1,400-acre Bark Camp coal mine site near Penfield in Clearfield County, Pa. Under a no-cost contract with the state of Pennsylvania, BAM is using boiler slag, causticizing byproducts (lime) and nonreclaimable clarifier sludge from International Paper Co. (Erie, Pa.). The mine reclamation techniques developed and monitored at the site include using man-made wetlands to treat acid mine drainage and testing anhydrous ammonia as a similar treatment agent. BAM researches and tests fly ash mixed with lime-based activators as fill material for land reclamation, and develops and uses artificial soil material from paper mill and tannery biosolids.

  11. Coupling of ion temperature gradient and trapped electron modes in the presence of impurities in tokamak plasmas

    SciTech Connect (OSTI)

    Du, Huarong; Wang, Zheng-Xiong, E-mail: zxwang@dlut.edu.cn [MOE Key Laboratory of Materials Modification by Beams, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)] [MOE Key Laboratory of Materials Modification by Beams, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Dong, J. Q. [Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China) [Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China); Southwestern Institute of Physics, Chengdu 610041 (China); Liu, S. F. [School of Physics, Nankai University, Tianjin 300071 (China)] [School of Physics, Nankai University, Tianjin 300071 (China)

    2014-05-15

    The coupling of ion temperature gradient (ITG or ?{sub i}) mode and trapped electron mode (TEM) in the presence of impurity ions is numerically investigated in toroidal collisionless plasmas, using the gyrokinetic integral eigenmode equation. A framework for excitations of the ITG modes and TEMs with respect to their driving sources is formulated first, and then the roles of impurity ions played in are analyzed comprehensively. In particular, the characteristics of the ITG and TEM instabilities in the presence of impurity ions are emphasized for both strong and weak coupling (hybrid and coexistent) cases. It is found that the impurity ions with inwardly (outwardly) peaked density profiles have stabilizing (destabilizing) effects on the hybrid (namely the TE-ITG) modes in consistence with previous works. A new finding of this work is that the impurity ions have stabilizing effects on TEMs in small ?{sub i} (?{sub i}?1) regime regardless of peaking directions of their density profiles whereas the impurity ions with density gradient L{sub ez}=L{sub ne}/L{sub nz}>1 (L{sub ez}<1) destabilize (stabilize) the TEMs in large ?{sub i} (?{sub i}?1) regime. In addition, the dependences of the growth rate, real frequency, eigenmode structure, and wave spectrum on charge concentration, charge number, and mass of impurity ions are analyzed in detail. The necessity for taking impurity ion effects on the features of turbulence into account in future transport experimental data analyses is also discussed.

  12. Publication sites productive uses of combustion ash

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

    Publication Sites Productive Uses of Combustion Ash For more information contact: e:mail: Public Affairs Golden, Colo., Jan. 23, 1997 -- A new technology brief published by the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) describes how ash use can reduce the cost of waste management and not harm the environment. Communities in the United States typically dump municipal solid waste combustion ash in landfills. The new technology brief describes recent studies where ash

  13. Coal Ash Corrosion Resistant Materials Testing

    SciTech Connect (OSTI)

    D. K. McDonald; P. L. Daniel; D. J. DeVault

    2003-08-31

    . The body of this report compares these for all of the samples in the test section. The 'Coal Ash Corrosion Resistant Materials Testing Program' is being conducted by The Babcock & Wilcox Company (B&W), the U.S. Department of Energy (DOE) and the Ohio Coal Development Office (OCDO) at Reliant Energy's Niles plant in Niles, Ohio to provide full-scale, in-situ testing of recently developed boiler superheater materials. Fireside corrosion is a key issue for improving efficiency of new coal fired power plants and improving service life in existing plants. In November 1998, B&W began development of a system to permit testing of advanced tube materials at metal temperatures typical of advanced supercritical steam temperatures (1100 F and higher) in a boiler exhibiting coal ash corrosive conditions. Several materials producers including Oak Ridge National Laboratory (ORNL) contributed advanced materials to the project. In the spring of 1999 a system consisting of three identical sections, each containing multiple segments of twelve different materials, was installed. The sections are cooled by reheat steam, and are located just above the furnace entrance in Niles Unit No.1, a 110 MWe unit firing high sulfur Ohio coal. In November 2001 the first section was removed for thorough metallurgical evaluation after 29 months of operation. The second section was removed in August of 2003. Its evaluation has been completed and is the subject of this report. The final section remains in service and is expected to be removed in the spring of 2005. This paper describes the program; its importance, the design, fabrication, installation and operation of the test system, materials utilized, and experience to date. This report briefly reviews the results of the evaluation of the first section and then presents the results of the evaluation of the second section.

  14. A comparison between sludge ash and fly ash on the improvement in soft soil

    SciTech Connect (OSTI)

    Deng-Fong Lin; Kae-Long Lin; Huan-Lin Luo

    2007-01-15

    In this study, the strength of soft cohesive subgrade soil was improved by applying sewage sludge ash as a soil stabilizer. Test results obtained were compared with earlier tests conducted on soil samples treated with fly ash. Five different proportions of sludge ash and fly ash were mixed with soft cohesive soil, and tests such as pH value, compaction, California bearing ratio, unconfined compressive strength (UCS), and triaxial compression were performed to understand soil strength improvement because of the addition of both ashes. Results indicate that pH values increase with extending curing age for soil with sludge ash added. The UCS of sludge ash/soil were 1.4 2 times better than untreated soil. However, compressive strength of sludge ash/soil was 20 30 kPa less than fly ash/soil. The bearing capacities for both fly ash/soil and sludge ash/soil were five to six times and four times, respectively, higher than the original capacity. Moreover, the cohesive parameter of shear strength rose with increased amounts of either ash added. Friction angle, however, decreased with increased amounts of either ash. Consequently, results show that sewage sludge ash can potentially replace fly ash in the improvement of the soft cohesive soil. 9 refs., 5 figs., 2 tabs.

  15. Petrographic characterization of economizer fly ash

    SciTech Connect (OSTI)

    Valentim, B.; Hower, J.C.; Soares, S.; Guedes, A.; Garcia, C.; Flores, D.; Oliveira, A.

    2009-11-15

    Policies for reducing NOx emissions have led power plants to restrict O{sub 2}, resulting in high-carbon fly ash production. Therefore, some potentially useful fly ash, such as the economizer fly ash, is discarded without a thorough knowledge of its composition. In order to characterize this type of fly ash, samples were collected from the economizer Portuguese power plant burning two low-sulfur bituminous coals. Characterization was also performed on economizer fly ash subsamples after wet sieving, density and magnetic separation. Analysis included atomic absorption spectroscopy, loss-on-ignition, scanning electron microscopy/energy-dispersive X-ray spectroscopy, optical microscopy, and micro-Raman spectroscopy.

  16. Photosynthetic pigment concentrations, gas exchange and vegetative growth for selected monocots and dicots treated with two contrasting coal fly ashes

    SciTech Connect (OSTI)

    Yunusa, I.A.M.; Burchett, M.D.; Manoharan, V.; DeSilva, D.L.; Eamus, D.; Skilbeck, C.G.

    2009-07-15

    There is uncertainty as to the rates of coal fly ash needed for optimum physiological processes and growth. In the current study we tested the hyothesis that photosynthetic pigments concentrations and CO{sub 2} assimilation (A) are more sensitive than dry weights in plants grown on media amended with coal fly ash. We applied the Terrestrial Plant Growth Test (Guideline 208) protocols of the Organization for Economic Cooperation and Development (OECD) to monocots (barley (Hordeum vulgare) and ryegrass (Secale cereale)) and dicots (canola (Brasica napus), radish (Raphanus sativus), field peas (Pisum sativum), and lucerne (Medicago sativa)) on media amended with fly ashes derived from semi-bituminous (gray ash) or lignite (red ash) coals at rates of 0, 2.5, 5.0, 10, or 20 Mg ha(-1). The red ash had higher elemental concentrations and salinity than the gray ash. Fly ash addition had no significant effect on germination by any of the six species. At moderate rates ({<=}10 Mg ha{sup -1}) both ashes increased (P < 0.05) growth rates and concentrations of chlorophylls a and b, but reduced carotenoid concentrations. Addition of either ash increased A in radish and transpiration in barley. Growth rates and final dry weights were reduced for all of the six test species when addition rates exceeded 10 Mg ha{sup -1} for gray ash and 5 Mg ha{sup -1} for red ash. We concluded that plant dry weights, rather than pigment concentrations and/or instantaneous rates of photosynthesis, are more consistent for assessing subsequent growth in plants supplied with fly ash.

  17. Undercompensated Kondo Impurity with Quantum Critical Point

    SciTech Connect (OSTI)

    Schlottmann, P.

    2000-02-14

    The low-temperature properties of a magnetic impurity of spin S interacting with an electron gas via anisotropic spin exchange are studied via Bethe's ansatz. For S>1/2 the impurity is only partially compensated at T=0 , leaving an effective spin that is neither integer nor half integer. The entropy has an essential singularity at H=T=0 , and the susceptibility and the specific heat follow power laws of H and T with nonuniversal exponents, which are the consequence of a quantum critical point. The results for the generalization to an arbitrary number of channels are also reported. (c) 2000 The American Physical Society.

  18. ACAA fly ash basics: quick reference card

    SciTech Connect (OSTI)

    2006-07-01

    Fly ash is a fine powdery material created when coal is burned to generate electricity. Before escaping into the environment via the utility stacks, the ash is collected and may be stored for beneficial uses or disposed of, if necessary. The use of fly ash provides environmental benefits, such as the conservation of natural resources, the reduction of greenhouse gas emissions and eliminating the needed for ash disposal in landfills. It is also a valuable mineral resource that is used in construction and manufacturing. Fly ash is used in the production of Portland cement, concrete, mortars and stuccos, manufactured aggregates along with various agricultural applications. As mineral filler, fly ash can be used for paints, shingles, carpet backing, plastics, metal castings and other purposes. This quick reference card is intended to provide the reader basic source, identification and composition, information specifically related to fly ash.

  19. Evaluation of Impurity Extremes in a Plutonium-loaded Borosilicate Glass

    SciTech Connect (OSTI)

    Fox, K.M.; Crawford, C.L.; Marra, J.C.; Bibler, N.E.; Hoffman, E.N.; Edwards, T.B. [Savannah River National Laboratory, Aiken, SC (United States)

    2008-07-01

    A vitrification technology utilizing a lanthanide borosilicate (LaBS) glass appears to be a viable option for the disposition of excess weapons-usable plutonium that is not suitable for processing into mixed oxide (MOX) fuel. A significant effort to develop a glass formulation and vitrification process to immobilize plutonium was completed in the mid-1990's. The LaBS glass formulation was found to be capable of immobilizing in excess of 10 wt % Pu and to be tolerant of a range of impurities. To confirm the results of previous testing with surrogate Pu feeds containing impurities, four glass compositions were selected for fabrication with actual plutonium oxide and impurities. The four compositions represented extremes in impurity type and concentration. The homogeneity and durability of these four compositions were measured. The homogeneity of the glasses was evaluated using x-ray diffraction (XRD) and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS). The XRD results indicated that the glasses were amorphous with no evidence of crystalline species in the glass. The SEM/EDS analyses did show the presence of some undissolved PuO{sub 2} material. The EDS spectra indicated that some of the PuO{sub 2} crystals also contained hafnium oxide. The SEM/EDS analyses showed that there were no heterogeneities in the glass due to the feed impurities. The durability of the glasses was measured using the Product Consistency Test (PCT). The PCT results indicated that the durability of Pu impurity glasses was comparable with Pu glasses without impurities and significantly more durable than the Environmental Assessment (EA) glass used as the benchmark for repository disposition of high-level waste (HLW) glasses. (authors)

  20. Effects of Point Defects and Impurities on Kinetics in NaAlH4 | Department

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

    of Energy Point Defects and Impurities on Kinetics in NaAlH4 Effects of Point Defects and Impurities on Kinetics in NaAlH4 A presentation showing that point defects play an important role in the kinetics of NaAlH4 including vacancies and interstitials consistent with observed effects of Ti. effects_of_point_defects.pdf (503.7 KB) More Documents & Publications Catalytic Effect of Ti for Hydrogen Cycling in NaAlH4 FTA - SunLine Transit Agency - Final Report Proceedings of the 1998 U.S. DOE

  1. Process and system for removing impurities from a gas

    DOE Patents [OSTI]

    Henningsen, Gunnar; Knowlton, Teddy Merrill; Findlay, John George; Schlather, Jerry Neal; Turk, Brian S

    2014-04-15

    A fluidized reactor system for removing impurities from a gas and an associated process are provided. The system includes a fluidized absorber for contacting a feed gas with a sorbent stream to reduce the impurity content of the feed gas; a fluidized solids regenerator for contacting an impurity loaded sorbent stream with a regeneration gas to reduce the impurity content of the sorbent stream; a first non-mechanical gas seal forming solids transfer device adapted to receive an impurity loaded sorbent stream from the absorber and transport the impurity loaded sorbent stream to the regenerator at a controllable flow rate in response to an aeration gas; and a second non-mechanical gas seal forming solids transfer device adapted to receive a sorbent stream of reduced impurity content from the regenerator and transfer the sorbent stream of reduced impurity content to the absorber without changing the flow rate of the sorbent stream.

  2. Effect of Various Impurities on the Hydrogen Absorption on SAES...

    Office of Environmental Management (EM)

    Effect of Various Impurities on the Hydrogen Absorption on SAES ST198 Effect of Various Impurities on the Hydrogen Absorption on SAES ST198 Presentation from the 36th Tritium Focus ...

  3. The Potts model on a Bethe lattice with nonmagnetic impurities

    SciTech Connect (OSTI)

    Semkin, S. V. Smagin, V. P.

    2015-10-15

    We have obtained a solution for the Potts model on a Bethe lattice with mobile nonmagnetic impurities. A method is proposed for constructing a “pseudochaotic” impurity distribution by a vanishing correlation in the arrangement of impurity atoms for the nearest sites. For a pseudochaotic impurity distribution, we obtained the phase-transition temperature, magnetization, and spontaneous magnetization jumps at the phase-transition temperature.

  4. Fused salt processing of impure plutonium dioxide to high-purity plutonium metal

    SciTech Connect (OSTI)

    Mullins, L.J.; Christensen, D.C.; Babcock, B.R.

    1982-01-01

    A process for converting impure plutonium dioxide (approx. 96% pure) to high-purity plutonium metal (>99.9%) was developed. The process consists of reducing the oxide to an impure plutonium metal intermediate with calcium metal in molten calcium chloride. The impure intermediate metal is cast into an anode and electrorefined to produce high-purity plutonium metal. The oxide reduction step is being done now on a 0.6-kg scale with the resulting yield being >99.5%. The electrorefining is being done on a 4.0-kg scale with the resulting yield being 80 to 85%. The purity of the product, which averages 99.98%, is essentially insensitive to the purity of the feed metal. The yield, however, is directly dependent on the chemical composition of the feed. To date, approximately 250 kg of impure oxide has been converted to pure metal by this processing sequence. The availability of impure plutonium dioxide, together with the need for pure plutonium metal, makes this sequence a valuable plutonium processing tool.

  5. Characterization and validation of an in silico toxicology model to predict the mutagenic potential of drug impurities*

    SciTech Connect (OSTI)

    Valerio, Luis G.; Cross, Kevin P.

    2012-05-01

    Control and minimization of human exposure to potential genotoxic impurities found in drug substances and products is an important part of preclinical safety assessments of new drug products. The FDA's 2008 draft guidance on genotoxic and carcinogenic impurities in drug substances and products allows use of computational quantitative structureactivity relationships (QSAR) to identify structural alerts for known and expected impurities present at levels below qualified thresholds. This study provides the information necessary to establish the practical use of a new in silico toxicology model for predicting Salmonella t. mutagenicity (Ames assay outcome) of drug impurities and other chemicals. We describe the model's chemical content and toxicity fingerprint in terms of compound space, molecular and structural toxicophores, and have rigorously tested its predictive power using both cross-validation and external validation experiments, as well as case studies. Consistent with desired regulatory use, the model performs with high sensitivity (81%) and high negative predictivity (81%) based on external validation with 2368 compounds foreign to the model and having known mutagenicity. A database of drug impurities was created from proprietary FDA submissions and the public literature which found significant overlap between the structural features of drug impurities and training set chemicals in the QSAR model. Overall, the model's predictive performance was found to be acceptable for screening drug impurities for Salmonella mutagenicity. -- Highlights: ? We characterize a new in silico model to predict mutagenicity of drug impurities. ? The model predicts Salmonella mutagenicity and will be useful for safety assessment. ? We examine toxicity fingerprints and toxicophores of this Ames assay model. ? We compare these attributes to those found in drug impurities known to FDA/CDER. ? We validate the model and find it has a desired predictive performance.

  6. Coal Ash Corrosion Resistant Materials Testing Program

    SciTech Connect (OSTI)

    McDonald, D K

    2003-04-22

    The "Coal Ash Corrosion Resistant Materials Testing Program" is being conducted by The Babcock & Wilcox Company (B&W), the U.S. Department of Energy (DOE) and the Ohio Coal Development Office (OCDO) at Reliant Energy's Niles plant in Niles, Ohio to provide full-scale, in-situ testing of recently developed boiler superheater materials. Fireside corrosion is a key issue for improving efficiency of new coal fired power plants and improving service life in existing plants. In November 1998, B&W began development of a system to permit testing of advanced tube materials at metal temperatures typical of advanced supercritical steam temperatures (1100°F and higher) in a boiler exhibiting coal ash corrosive conditions. Several materials producers including Oak Ridge National Laboratory (ORNL) contributed advanced materials to the project. In the spring of 1999 a system consisting of three identical sections, each containing multiple segments of twelve different materials, was installed. The sections are cooled by reheat steam, and are located just above the furnace entrance in Niles' Unit #1, a 110 MWe unit firing high sulfur Ohio coal. In November 2001 the first section was removed for thorough metallurgical evaluation after 33 months of operation. The second and third sections remain in service and the second is expected to be removed in the fall of 2003; the last is tentatively planned for the fall of 2004. This paper describes the program; its importance; the design, fabrication, installation and operation of the test system; materials utilized; experience to date; and results of the evaluation of the first section.

  7. Combustion with reduced carbon in the ash

    DOE Patents [OSTI]

    Kobayashi, Hisashi; Bool, III, Lawrence E.

    2005-12-27

    Combustion of coal in which oxygen is injected into the coal as it emerges from burner produces ash having reduced amounts of carbon.

  8. Power Radiated from ITER and CIT by Impurities

    DOE R&D Accomplishments [OSTI]

    Cummings, J.; Cohen, S. A.; Hulse, R.; Post, D. E.; Redi, M. H.; Perkins, J.

    1990-07-01

    The MIST code has been used to model impurity radiation from the edge and core plasmas in ITER and CIT. A broad range of parameters have been varied, including Z{sub eff}, impurity species, impurity transport coefficients, and plasma temperature and density profiles, especially at the edge. For a set of these parameters representative of the baseline ITER ignition scenario, it is seen that impurity radiation, which is produced in roughly equal amounts by the edge and core regions, can make a major improvement in divertor operation without compromising core energy confinement. Scalings of impurity radiation with atomic number and machine size are also discussed.

  9. Characterization of ash cenospheres in fly ash from Australian power stations

    SciTech Connect (OSTI)

    Ling-ngee Ngu; Hongwei Wu; Dong-ke Zhang

    2007-12-15

    Ash cenospheres in fly ashes from five Australian power stations have been characterized. The experimental data show that ash cenosphere yield varies across the power stations. Ash partitioning occurred in the process of ash cenosphere formation during combustion. Contradictory to conclusions from the literature, iron does not seem to be essential to ash cenosphere formation in the cases examined in the present work. Further investigation was also undertaken on a series of size-fractioned ash cenosphere samples from Tarong power station. It is found that about 70 wt% of ash cenospheres in the bulk sample have sizes between 45 and 150 {mu}m. There are two different ash cenosphere structures, that is, single-ring structure and network structure. The percentage of ash cenospheres of a network structure increases with increasing ash cenosphere size. Small ash cenospheres (in the size fractions {lt}150 {mu}m) have a high SiO{sub 2}/Al{sub 2}O{sub 3} ratio, and the majority of the ash cenospheres are spherical and of a single-ring structure. Large ash cenosphere particles (in the size fractions of 150-250 {mu}m and {gt}250 {mu}m) have a low SiO{sub 2}/Al{sub 2}O{sub 3} ratio, and a high proportion of the ash cenospheres are nonspherical and of a network structure. A novel quantitative technique has been developed to measure the diameter and wall thickness of ash cenospheres on a particle-to-particle basis. A monolayer of size-fractioned ash cenospheres was dispersed on a pellet, which was then polished carefully before being examined using a scanning electron microscope and image analysis. The ash cenosphere wall thickness broadly increases with increasing ash cenosphere size. The ratios between wall thickness and diameter of ash cenospheres are limited between an upper bound of about 10.5% and a lower bound of about 2.5%, irrespective of the ash cenosphere size. 52 refs., 9 figs., 4 tabs.

  10. Treatment of fly ash for use in concrete

    DOE Patents [OSTI]

    Boxley, Chett

    2012-05-15

    A process for treating fly ash to render it highly usable as a concrete additive. A quantity of fly ash is obtained that contains carbon and which is considered unusable fly ash for concrete based upon foam index testing. The fly ash is mixed with a quantity of spray dryer ash (SDA) and water to initiate a geopolymerization reaction and form a geopolymerized fly ash. The geopolymerized fly ash is granulated. The geopolymerized fly ash is considered usable fly ash for concrete according to foam index testing. The geopolymerized fly ash may have a foam index less than 40%, and in some cases less than 20%, of the foam index of the untreated fly ash. An optional alkaline activator may be mixed with the fly ash and SDA to facilitate the geopolymerization reaction. The alkaline activator may contain an alkali metal hydroxide, carbonate, silicate, aluminate, or mixtures thereof.

  11. Motion of a distinguishable Impurity in the Bose gas: Arrested expansion without a lattice and impurity snaking

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

    Neil J. Robinson; Caux, Jean -Sebastien; Konik, Robert M.

    2016-04-07

    We consider the real-time dynamics of an initially localized distinguishable impurity injected into the ground state of the Lieb-Liniger model. Focusing on the case where integrability is preserved, we numerically compute the time evolution of the impurity density operator in regimes far from analytically tractable limits. We find that the injected impurity undergoes a stuttering motion as it moves and expands. For an initially stationary impurity, the interaction-driven formation of a quasibound state with a hole in the background gas leads to arrested expansion—a period of quasistationary behavior. In conclusion, when the impurity is injected with a finite center-of-mass momentum,more » the impurity moves through the background gas in a snaking manner, arising from a quantum Newton’s cradlelike scenario where momentum is exchanged back and forth between the impurity and the background gas.« less

  12. Hunt's Ash Springs Pool & Spa Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Hunt's Ash Springs Pool & Spa Low Temperature Geothermal Facility Jump to: navigation, search Name Hunt's Ash Springs Pool & Spa Low Temperature Geothermal Facility Facility Hunt's...

  13. Impact of Biodiesel on Ash Emissions and Lubricant Properties...

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

    Biodiesel on Ash Emissions and Lubricant Properties Affecting Fuel Economy and Engine Wear Impact of Biodiesel on Ash Emissions and Lubricant Properties Affecting Fuel Economy and ...

  14. Entrained-flow dry-bottom gasification of high-ash coals in coal-water slurries

    SciTech Connect (OSTI)

    E.G. Gorlov; V.G. Andrienko; K.B. Nefedov; S.V. Lutsenko; B.K. Nefedov

    2009-04-15

    It was shown that the effective use of dry ash removal during entrained-flow gasification of coal-water slurries consists in simplification of the ash storage system and utilization of coal ash, a decrease in the coal demand, a reduction in the atmospheric emissions of noxious substances and particulate matter, and abandonment of the discharge of water used for ash slurry. According to the results of gasification of coal-water slurries (5-10 {mu}m) in a pilot oxygen-blow unit at a carbon conversion of >91%, synthesis gas containing 28.5% CO, 32.5% H{sub 2}, 8.2% CO{sub 2}, 1.5% CH{sub 4}, the rest being nitrogen, was obtained. The fly ash in its chemical composition, particle size, and density meets the requirements of the European standard EN 450 as a cement additive for concrete manufacture.

  15. Settlement of footing on compacted ash bed

    SciTech Connect (OSTI)

    Ramasamy, G.; Pusadkar, S.S.

    2007-11-15

    Compacted coal ash fills exhibit capillary stress due to contact moisture and preconsolidation stress due to the compaction process. As such, the conventional methods of estimating settlement of footing on cohesionless soils based on penetration tests become inapplicable in the case of footings on coal ash fills, although coal ash is also a cohesionless material. Therefore, a method of estimating load-settlement behavior of footings resting on coal ash fills accounting for the effect of capillary and preconsolidation stresses is presented here. The proposed method has been validated by conducting plate load tests on laboratory prepared compacted ash beds and comparing the observed and predicted load-settlement behavior. Overestimation of settlement greater than 100% occurs when capillary and preconsolidation stresses are not accounted for, as is the case in conventional methods.

  16. Geotechnical characterization of some Indian fly ashes

    SciTech Connect (OSTI)

    Das, S.K.; Yudhbir

    2005-10-01

    This paper reports the findings of experimental studies with regard to some common engineering properties (e.g., grain size, specific gravity, compaction characteristics, and unconfined compression strength) of both low and high calcium fly ashes, to evaluate their suitability as embankment materials and reclamation fills. In addition, morphology, chemistry, and mineralogy of fly ashes are studied using scanning electron microscope, electron dispersive x-ray analyzer, x-ray diffractometer, and infrared absorption spectroscopy. In high calcium fly ash, mineralogical and chemical differences are observed for particles, {gt}75 {mu} m and the particles of {lt} 45 {mu} m size. The mode and duration of curing significantly affect the strength and stress-strain behavior of fly ashes. The geotechnical properties of fly ash are governed by factors like lime content (CaO), iron content (Fe{sub 2}O{sub 3}) and loss on ignition. The distinct difference between self-hardening and pozzolanic reactivity has been emphasized.

  17. Silicon materials task of the low cost solar array project (Phase III). Effects of impurities and processing on silicon solar cells. Phase III summary and seventeenth quarterly report, Volume 2: analysis of impurity behavior

    SciTech Connect (OSTI)

    Hopkins, R.H.; Davis, J.R.; Rohatgi, A.; Campbell, R.B.; Blais, P.D.; Rai-Choudhury, P.; Stapleton, R.E.; Mollenkopf, H.C.; McCormick, J.R.

    1980-01-23

    The object of this phase of the program has been to investigate the effects of various processes, metal contaminants and contaminant-process interactions on the properties of silicon and on the performance of terrestrial silicon solar cells. The study encompassed topics including thermochemical (gettering) treatments, base doping concentration, base doping type (n vs. p), grain boundary-impurity interaction, non-uniformity of impurity distribution, long term effects of impurities, as well as synergic and complexing phenomena. The program approach consists in: (1) the growth of doubly and multiply-doped silicon single crystals containing a baseline boron or phosphorus dopant and specific impurities which produce deep levels in the forbidden band gap; (2) assessment of these crystals by chemical, microstructural, electrical and solar cell tests; (3) correlation of the impurity type and concentration with crystal quality and device performance; and (4) delineation of the role of impurities and processing on subsequent silicon solar cell performance. The overall results reported are based on the assessment of nearly 200 silicon ingots. (WHK)

  18. Treatment of fly ash for use in concrete

    DOE Patents [OSTI]

    Boxley, Chett; Akash, Akash; Zhao, Qiang

    2013-01-08

    A process for treating fly ash to render it highly usable as a concrete additive. A quantity of fly ash is obtained that contains carbon and which is considered unusable fly ash for concrete based upon foam index testing. The fly ash is mixed with an activator solution sufficient to initiate a geopolymerization reaction and for a geopolymerized fly ash. The geopolymerized fly ash is granulated. The geopolymerized fly ash is considered usable fly ash for concrete according to foam index testing. The geopolymerized fly ash may have a foam index less than 35% of the foam index of the untreated fly ash, and in some cases less than 10% of the foam index of the untreated fly ash. The activator solution may contain an alkali metal hydroxide, carbonate, silicate, aluminate, or mixtures thereof.

  19. Treatment of fly ash for use in concrete

    DOE Patents [OSTI]

    Boxley, Chett; Akash, Akash; Zhao, Qiang

    2012-05-08

    A process for treating fly ash to render it highly usable as a concrete additive. A quantity of fly ash is obtained that contains carbon and which is considered unusable fly ash for concrete based upon foam index testing. The fly ash is mixed with an activator solution sufficient to initiate a geopolymerization reaction and for a geopolymerized fly ash. The geopolymerized fly ash is granulated. The geopolymerized fly ash is considered usable fly ash for concrete according to foam index testing. The geopolymerized fly ash may have a foam index less than 35% of the foam index of the untreated fly ash, and in some cases less than 10% of the foam index of the untreated fly ash. The activator solution may contain an alkali metal hydroxide, carbonate, silicate, aluminate, or mixtures thereof.

  20. Assessment of Embrittlement of VHTR Structural Alloys in Impure Helium Environments

    SciTech Connect (OSTI)

    Crone, Wendy; Cao, Guoping; Sridhara, Kumar

    2013-05-31

    The helium coolant in high-temperature reactors inevitably contains low levels of impurities during steady-state operation, primarily consisting of small amounts of H{sub 2}, H{sub 2}O, CH{sub 4}, CO, CO{sub 2}, and N{sub 2} from a variety of sources in the reactor circuit. These impurities are problematic because they can cause significant long-term corrosion in the structural alloys used in the heat exchangers at elevated temperatures. Currently, the primary candidate materials for intermediate heat exchangers are Alloy 617, Haynes 230, Alloy 800H, and Hastelloy X. This project will evaluate the role of impurities in helium coolant on the stress-assisted grain boundary oxidation and creep crack growth in candidate alloys at elevated temperatures. The project team will: • Evaluate stress-assisted grain boundary oxidation and creep crack initiation and crack growth in the temperature range of 500-850°C in a prototypical helium environment. • Evaluate the effects of oxygen partial pressure on stress-assisted grain boundary oxidation and creep crack growth in impure helium at 500°C, 700°C, and 850°C respectively. • Characterize the microstructure of candidate alloys after long-term exposure to an impure helium environment in order to understand the correlation between stress-assisted grain boundary oxidation, creep crack growth, material composition, and impurities in the helium coolant. • Evaluate grain boundary engineering as a method to mitigate stress-assisted grain boundary oxidation and creep crack growth of candidate alloys in impure helium. The maximum primary helium coolant temperature in the high-temperature reactor is expected to be 850-1,000°C.Corrosion may involve oxidation, carburization, or decarburization mechanisms depending on the temperature, oxygen partial pressure, carbon activity, and alloy composition. These corrosion reactions can substantially affect long-term mechanical properties such as crack- growth rate and fracture

  1. Integrable Two-Impurity Kondo Model

    SciTech Connect (OSTI)

    Schlottmann, P.

    1998-06-01

    The exact solution by means of Bethe{close_quote}s {ital Ansatz} of a variant of the two-impurity Kondo problem is presented. The occupation of the singlet and triplet states, the expectation value {l_angle}{rvec S}{sub 1}{center_dot} {cflx S}{sub 2}{r_angle} , the homogeneous and staggered magnetic field susceptibilities, and the specific heat {gamma} coefficient are studied for the ground state as a function of the Ruderman-Kittel-Kasuya-Yosida{endash}coupling strength. {copyright} {ital 1998} {ital The American Physical Society}

  2. Leaching of mixtures of biochar and fly ash

    SciTech Connect (OSTI)

    Palumbo, Anthony V.; Porat, Iris; Phillips, Jana R.; Amonette, James E.; Drake, Meghan M.; Brown, Steven D.; Schadt, Christopher W.

    2009-06-22

    Increasing atmospheric levels of greenhouse gases, especially CO2, and their effects on global temperature have led to interest in the possibility of carbon storage in terrestrial environments. Both the residual char from biomass pyrolysis (biochar) and fly ash from coal combustion have the potential to significantly expand terrestrial sequestration options. Both biochar and fly ash also have potentially beneficial effects on soil properties. Fly ash has been shown to increase porosity, water-holding capacity, pH, conductivity, and dissolved SO42-, CO32-, Cl- and basic cations. Adding biochar to soil generally raises pH, increases total nitrogen and total phosphorous, encourages greater root development, improves cation exchange capacity and decreases available aluminum. A combination of these benefits likely is responsible for observed increases in yields for crops such as corn and sugarcane. In addition, it has been found that soils with added biochar emit lower amounts of other greenhouse gases (methane and nitrous oxide) than do unamended soils. Biochar and fly ash amendments may be useful in promoting terrestrial carbon sequestration on currently underutilized and degraded lands. For example, about 1% of the US surface lands consist of previously mined lands or highway rights-of-way. Poorly managed lands could count for another 15% of US area. Biochar and fly ash amendments could increase productivity of these lands and increase carbon storage in the soil. Previous results showed minimal leaching of organic carbon and metals from a variety of fly ashes. In the present study, we examined the properties of mixtures of biochar, fly ash, and soil and evaluated the leaching of organic carbon and metals from these mixtures. The carbon sorption experiments showed release of carbon from biochar, rather than sorption, except at the highest concentrations in the Biochar HW sample. Similar results were obtained by others for oxidative leaching of bituminous coal, in

  3. Measurement of plasma current dependent changes in impurity transport...

    Office of Scientific and Technical Information (OSTI)

    simultaneous agreement between experiment and simulation in both the impurity particle transport and ion heat transport channels is attainable within experimental more ...

  4. Direct Determination of the Chemical Bonding of Individual Impurities...

    Office of Scientific and Technical Information (OSTI)

    Publisher's Accepted Manuscript: Direct Determination of the Chemical Bonding of Individual Impurities in Graphene Prev Next Title: Direct Determination of the Chemical ...

  5. Statistical analysis of variations in impurity ion heating at...

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

    ... heating of majority ions has been studied; 16 and most recently, the charge and mass dependency of impurity ion heating has been investigated. 17 Despite many laboratory ...

  6. Rocky Flats ash test procedure (sludge stabilization)

    SciTech Connect (OSTI)

    Winstead, M.L.

    1995-09-14

    Rocky Flats Ash items have been identified as the next set of materials to be stabilized. This test is being run to determine charge sizes and soak times to completely stabilize the Rocky Flats Ash items. The information gathered will be used to generate the heating rampup cycle for stabilization. This test will also gain information on the effects of the glovebox atmosphere (moisture) on the stabilized material. This document provides instructions for testing Rocky Flats Ash in the HC-21C muffle furnace process.

  7. Potential products from North Dakota lignite fly ash. Final report

    SciTech Connect (OSTI)

    Anderson, G R

    1980-06-01

    Four major areas where fly ash can be used are explored. Concrete building blocks with fly ash replacing 50% of the portland cement have proven to be successful using current ASTM standards. Results in the ceramics area show that a ceramic-like product using fly ash and crushed glass with a small amount of clay as a green binder. Some preliminary results using sulfur ash in building materials are reported and with results of making wallboard from ash. (MHR)

  8. Ashe County- Wind Energy System Ordinance

    Broader source: Energy.gov [DOE]

    In 2007 Ashe County adopted a wind ordinance to regulate the use of wind-energy systems in unincorporated areas of the county and to describe the conditions by which a permit for installing such a...

  9. Fly ash system technology improves opacity

    SciTech Connect (OSTI)

    2007-06-15

    Unit 3 of the Dave Johnston Power Plant east of Glenrock, WY, USA had problems staying at or below the opacity limits set by the state. The unit makes use of a Lodge Cottrell precipitator. When the plant changed to burning Power River Basin coal, ash buildup became a significant issue as the fly ash control system was unable to properly evacuate hoppers on the unit. To overcome the problem, the PLC on the unit was replaced with a software optimization package called SmartAsh for the precipitator fly ash control system, at a cost of $500,000. After the upgrade, there have been no plugged hoppers and the opacity has been reduced from around 20% to 3-5%. 2 figs.

  10. Rocky Flats Ash test procedure (sludge stabilization)

    SciTech Connect (OSTI)

    Funston, G.A.

    1995-06-14

    Rocky Flats Ash items have been identified as the next set of materials to be stabilized. This test is being run to determine charge sizes and soak times to completely stabilize the Rocky Flats Ash items. The information gathered will be used to generate the heating rampup cycle for stabilization. The test will provide information to determine charge sizes, soak times and mesh screen sizes (if available at time of test) for stabilization of Rocky Flats Ash items to be processed in the HC-21C Muffle Furnace Process. Once the charge size and soak times have been established, a program for the temperature controller of the HC-21C Muffle Furnace process will be generated for processing Rocky Flats Ash.

  11. Flue gas desulfurization gypsum and fly ash

    SciTech Connect (OSTI)

    Not Available

    1992-05-01

    The Cumberland Fossil Plant (CUF) is located in Stewart County, Tennessee, and began commercial operation in 1972. This is the Tennessee Valley Authority`s newest fossil (coal-burning) steam electric generating plant. Under current operating conditions, the plant burns approximately seven million tons of coal annually. By-products from the combustion of coal are fly ash, approximately 428,000 tons annually, and bottom ash, approximately 115,000 tons annually. Based on historical load and projected ash production rates, a study was initially undertaken to identify feasible alternatives for marketing, utilization and disposal of ash by-products. The preferred alternative to ensure that facilities are planned for all by-products which will potentially be generated at CUF is to plan facilities to handle wet FGD gypsum and dry fly ash. A number of different sites were evaluated for their suitability for development as FGD gypsum and ash storage facilities. LAW Engineering was contracted to conduct onsite explorations of sites to develop information on the general mature of subsurface soil, rock and groundwater conditions in the site areas. Surveys were also conducted on each site to assess the presence of endangered and threatened species, wetlands and floodplains, archaeological and cultural resources, prime farmland and other site characteristics which must be considered from an environmental perspective.

  12. Impurity effects in superconducting UPt sub 3

    SciTech Connect (OSTI)

    Aronson, M.C. (The Harrison M. Randall Laboratory of Physics, The University of Michigan, Ann Arbor, Michigan 48109 (USA)); Vorenkamp, T.; Koziol, Z.; de Visser, A.; Bakker, K.; Franse, J.J.M. (Natuurkundig Laboratorium der Universiteit van Amsterdam, Valckenierstraat 65, 1018 XE Amsterdam, The Netherlands (USA)); Smith, J.L. (Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (USA))

    1991-04-15

    Superconducting UPt{sub 3} is characterized by a novel and complex magnetic field-temperature phase diagram, with two superconducting transitions at {ital T}{sub {ital c}1} and {ital T}{sub {ital c}2} in zero field. We have studied the effects of Pd and Y impurities on the zero field superconducting properties of UPt{sub 3}. Resistance measurements show that both dopants increase the residual resistivity and decrease the spin fluctuation temperature in the normal state. {ital T}{sub {ital c}1} is depressed by both dopants, but more effectively by Pd. {vert bar}{ital T}{sub {ital c}1} {minus} {ital T}{sub {ital c}2}{vert bar} is essentially unaffected by Y doping, but increases dramatically with Pd doping.

  13. Impurity Transport Studies in the Wendelstein 7-AS Stellarator

    SciTech Connect (OSTI)

    Burhenn, Rainer; Baldzuhn, Juergen; Brakel, Rudolf

    2004-07-15

    The dependence of impurity transport on plasma parameters in the modular stellarator Wendelstein 7-AS was investigated by means of a laser blow-off technique. An increased impurity transport at higher heating power and lower magnetic field strength as well as no effect of the isotope composition on the impurity confinement was observed. The most critical scaling with respect to stationary operation at high density is the improved confinement of impurities at high densities, leading to a degradation of plasma energy by increasing radiation and to a loss of density control. This was attributed to a reduction of the impurity diffusion coefficient with density. After installation of island divertor modules, a transition from normal confinement into the high-density H-mode (HDH) at a certain power-dependent threshold density appeared. This transition is characterized by a strong reduction of the impurity confinement time and an increase in energy confinement time. In the HDH operational regime, access to even higher densities (4 x 10{sup 20} m{sup -3}) than achieved before became possible under stationary operation conditions. Impurity transport measurements and model predictions indicate that the reduction of the impurity confinement in HDH is caused by not only a reduction of the inward convection in the core plasma but also possibly by changes in the edge transport. Comparison of experimental data with an axisymmetric transport model should elucidate the role of stellarator-specific transport aspects.

  14. Quantum entanglement in the two-impurity Kondo model

    SciTech Connect (OSTI)

    Cho, Sam Young; McKenzie, Ross H.

    2006-01-15

    In order to quantify quantum entanglement in two-impurity Kondo systems, we calculate the concurrence, negativity, and von Neumann entropy. The entanglement of the two Kondo impurities is shown to be determined by two competing many-body effects, namely the Kondo effect and the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction, I. Due to the spin-rotational invariance of the ground state, the concurrence and negativity are uniquely determined by the spin-spin correlation between the impurities. It is found that there exists a critical minimum value of the antiferromagnetic correlation between the impurity spins which is necessary for entanglement of the two impurity spins. The critical value is discussed in relation with the unstable fixed point in the two-impurity Kondo problem. Specifically, at the fixed point there is no entanglement between the impurity spins. Entanglement will only be created [and quantum information processing (QIP) will only be possible] if the RKKY interaction exchange energy, I, is at least several times larger than the Kondo temperature, T{sub K}. Quantitative criteria for QIP are given in terms of the impurity spin-spin correlation.

  15. Single atom impurity in a single molecular transistor

    SciTech Connect (OSTI)

    Ray, S. J.

    2014-10-21

    The influence of an impurity atom on the electrostatic behaviour of a Single Molecular Transistor was investigated through Ab-initio calculations in a double-gated geometry. The charge stability diagram carries unique signature of the position of the impurity atom in such devices which together with the charging energy of the molecule could be utilised as an electronic fingerprint for the detection of such impurity states in a nano-electronic device. The two gated geometry allows additional control over the electrostatics as can be seen from the total energy surfaces (for a specific charge state), which is sensitive to the positions of the impurity. These devices which are operational at room temperature can provide significant advantages over the conventional silicon based single dopant devices functional at low temperature. The present approach could be a very powerful tool for the detection and control of individual impurity atoms in a single molecular device and for applications in future molecular electronics.

  16. Effect of curing conditions on the geotechnical and geochemical properties of CFBC ashes

    SciTech Connect (OSTI)

    Bland, A.E.

    1999-07-01

    Western Research Institute, in cooperation with the US Department of Energy Federal Energy Technology Center, initiated a multi-year program to examine the relationship between CFBC ash chemistry and geotechnical properties as they relate to ash disposal and utilization. Four CFBC facilities supplied ash from their units for the study representing high-sulfur (4%) and medium-sulfur (1.8%) bituminous coal. Sub-bituminous coal (0.9% sulfur) and petroleum coke (5--6% sulfur) fired ashes were also included in the study. The ashes were composed principally of large quantities of anhydrite (CaSO{sub 4}) and lime (CaO) and minor amounts of calcite (CaCO{sub 3}). The ash curing study addressed the impact of curing conditions (sealed and saturated curing and 23 C and 5 C curing temperature) on the geochemical and geotechnical properties of the ash. The strength development and expansion varied with the type and characteristics of the ashes. The expansion appeared to be inversely related to strength development. As the strength decreased under saturated curing, the expansion increased significantly. The application of 5 C saturated curing resulted in further strength loss and increased expansion. The hydration reaction products appeared to be principally the hydration of lime (CaO) to portlandite (Ca[OH]{sub 2}), the hydration of anhydrite (CaSO{sub 4}) to gypsum (CaSO{sub 4} {center{underscore}dot} 2H{sub 2}O), and the precipitation of ettringite (Ca{sub 6}Al{sub 2}[SO{sub 4}]{sub 3}[OH]{sub 12} {center{underscore}dot} 26H{sub 2}O) from the soluble calcium, sulfates and alumina. No thaumasite was noted in the specimens. The ashes appeared to follow one of several hydration reaction trends: (1) ettringite-only development, (2) ettringite and/or gypsum early followed by later gypsum formation, or (3) gypsum-only formation. Testing confirmed that the hydration reaction chemistry was related to geotechnical properties of the ashes. Strength development and expansion appeared to

  17. Gel nanostructure in alkali-activated binders based on slag and fly ash, and effects of accelerated carbonation

    SciTech Connect (OSTI)

    Bernal, Susan A.; Provis, John L.; Walkley, Brant; San Nicolas, Rackel; Gehman, John D.; Brice, David G.; Kilcullen, Adam R.; Duxson, Peter; Deventer, Jannie S.J. van

    2013-11-15

    Binders formed through alkali-activation of slags and fly ashes, including ‘fly ash geopolymers’, provide appealing properties as binders for low-emissions concrete production. However, the changes in pH and pore solution chemistry induced during accelerated carbonation testing provide unrealistically low predictions of in-service carbonation resistance. The aluminosilicate gel remaining in an alkali-activated slag system after accelerated carbonation is highly polymerised, consistent with a decalcification mechanism, while fly ash-based binders mainly carbonate through precipitation of alkali salts (bicarbonates at elevated CO{sub 2} concentrations, or carbonates under natural exposure) from the pore solution, with little change in the binder gel identifiable by nuclear magnetic resonance spectroscopy. In activated fly ash/slag blends, two distinct gels (C–A–S–H and N–A–S–H) are formed; under accelerated carbonation, the N–A–S–H gel behaves comparably to fly ash-based systems, while the C–A–S–H gel is decalcified similarly to alkali-activated slag. This provides new scope for durability optimisation, and for developing appropriate testing methodologies. -- Highlights: •C-A-S-H gel in alkali-activated slag decalcifies during accelerated carbonation. •Alkali-activated fly ash gel changes much less under CO{sub 2} exposure. •Blended slag-fly ash binder contains two coexisting gel types. •These two gels respond differently to carbonation. •Understanding of carbonation mechanisms is essential in developing test methods.

  18. Apparatus for purifying arsine, phosphine, ammonia, and inert gases to remove Lewis acid and oxidant impurities therefrom

    DOE Patents [OSTI]

    Tom, Glenn M.; Brown, Duncan W.

    1991-01-08

    An apparatus for purifying a gaseous mixture comprising arsine, phosphine, ammonia, and/or inert gases, to remove Lewis acid and/or oxidant impurities therefrom, comprising a vessel containing a bed of a scavenger, the scavenger including a support having associated therewith an anion which is effective to remove such impurities, such anion being selected from one or more members of the group consisting of: (i) carbanions whose corresponding protonated compounds have a pK.sub.a value of from about 22 to about 36; and (ii) anions formed by reaction of such carbanions with the primary component of the mixture.

  19. Comparative study on the characteristics of fly ash and bottom ash geopolymers

    SciTech Connect (OSTI)

    Chindaprasirt, Prinya; Jaturapitakkul, Chai; Chalee, Wichian; Rattanasak, Ubolluk

    2009-02-15

    This research was conducted to compare geopolymers made from fly ash and ground bottom ash. Sodium hydroxide (NaOH) and sodium silicate (Na{sub 2}SiO{sub 3}) solutions were used as activators. A mass ratio of 1.5 Na{sub 2}SiO{sub 3}/NaOH and three concentrations of NaOH (5, 10, and 15 M) were used; the geopolymers were cured at 65 deg. C for 48 h. A Fourier transform infrared spectrometer (FT-IR), differential scanning calorimeter (DSC), and scanning electron microscope (SEM) were used on the geopolymer pastes. Geopolymer mortars were also prepared in order to investigate compressive strength. The results show that both fly ash and bottom ash can be utilized as source materials for the production of geopolymers. The properties of the geopolymers are dependent on source materials and the NaOH concentration. Fly ash is more reactive and produces a higher degree of geopolymerization in comparison with bottom ash. The moderate NaOH concentration of 10 M is found to be suitable and gives fly ash and bottom ash geopolymer mortars with compressive strengths of 35 and 18 MPa.

  20. Scale-Up and Demonstration of Fly Ash Ozonation Technology

    SciTech Connect (OSTI)

    Rui Afonso; R. Hurt; I. Kulaots

    2006-03-01

    The disposal of fly ash from the combustion of coal has become increasingly important. When the fly ash does not meet the required specification for the product or market intended, it is necessary to beneficiate it to achieve the desired quality. This project, conducted at PPL's Montour SES, is the first near full-scale ({approx}10 ton/day), demonstration of ash ozonation technology. Bituminous and sub bituminous ashes, including two ash samples that contained activated carbon, were treated during the project. Results from the tests were very promising. The ashes were successfully treated with ozone, yielding concrete-suitable ash quality. Preliminary process cost estimates indicate that capital and operating costs to treat unburned carbon are competitive with other commercial ash beneficiation technologies at a fraction of the cost of lost sales and/or ash disposal costs. This is the final technical report under DOE Cooperative Agreement No.: DE-FC26-03NT41730.

  1. Tungsten impurity transport experiments in Alcator C-Mod to address...

    Office of Scientific and Technical Information (OSTI)

    Tungsten impurity transport experiments in Alcator C-Mod to address high priority research and development for ITER Citation Details In-Document Search Title: Tungsten impurity ...

  2. Four-year prospective study of the respiratory effects of volcanic ash from Mt. St. Helens

    SciTech Connect (OSTI)

    Buist, A.S.; Vollmer, W.M.; Johnson, L.R.; Bernstein, R.S.; McCamant, L.E.

    1986-04-01

    This report describes the 4-yr follow-up of 712 loggers exposed over an extended period to varying levels of fresh volcanic ash from the 1980 eruptions of Mt. St. Helens. Concerns related to the irritant effect the ash might have on the airways and also to its fibrogenic potential if exposures were intense and continued over many years. Our subjects were divided into 3 groups: high, low, and no exposure. Baseline testing was begun in June 1980, 1 month after the major eruption, and follow-up testing continued on an annual basis through 1984; 88% of the loggers have been tested at least 3 times. Analysis of lung function data showed that a significant, exposure-related decline in FEV1 occurred during the first year after the eruption. The decline was short-lived, however, and by 1984 the differences between exposure groups were no longer significant. Self-reported symptoms of cough, phlegm, and wheeze showed a similar pattern. No ash-related changes were seen in chest roentgenograms taken in 1980 and in 1984. Our findings are consistent with the hypothesis that the inhaled ash caused mucus hypersecretion and/or airway inflammation that reversed when the exposure levels decreased. The ash levels to which the loggers were exposed were low compared with permissible occupational levels for nuisance dusts, but generally higher than the total suspended particulate levels permissible in ambient air.

  3. Hydrothermal reaction of fly ash. Final report

    SciTech Connect (OSTI)

    Brown, P.W.

    1994-12-31

    The reactions which occur when fly ash is treated under hydrothermal conditions were investigated. This was done for the following primary reasons. The first of these is to determine the nature of the phases that form to assess the stabilities of these phases in the ambient environment and, finally, to assess whether these phases are capable of sequestering hazardous species. The second reason for undertaking this study was whether, depending on the composition of the ash and the presence of selected additives, it would be possible under hydrothermal conditions to form compounds which have cementitious properties. Formation of four classes of compounds, which bracket likely fly ash compositional ranges, were selected for study. The classes are calcium silicate hydrates, calcium selenates, and calcium aluminosulfates, and silicate-based glasses. Specific compounds synthesized were determined and their stability regions assessed. As part of stability assessment, the extent to which selected hazardous species are sequestered was determined. Finally, the cementing properties of these compounds were established. The results obtained in this program have demonstrated that mild hydrothermal conditions can be employed to improve the reactivity of fly ash. Such improvements in reactivity can result in the formation of monolithic forms which may exhibit suitable mechanical properties for selected applications as building materials. If the ashes involved are considered hazardous, the mechanical properties exhibited indicated the forms could be handled in a manner which facilitates their disposal.

  4. Extraction process for removing metallic impurities from alkalide metals

    DOE Patents [OSTI]

    Royer, L.T.

    1987-03-20

    A development is described for removing metallic impurities from alkali metals by employing an extraction process wherein the metallic impurities are extracted from a molten alkali metal into molten lithium metal due to the immiscibility of the alkali metals in lithium and the miscibility of the metallic contaminants or impurities in the lithium. The purified alkali metal may be readily separated from the contaminant-containing lithium metal by simple decanting due to the differences in densities and melting temperatures of the alkali metals as compared to lithium.

  5. Alternating current response of carbon nanotubes with randomly distributed impurities

    SciTech Connect (OSTI)

    Hirai, Daisuke; Watanabe, Satoshi [Department of Materials Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan); Yamamoto, Takahiro [Department of Electrical Engineering and Department of Liberal Arts (Physics), Tokyo University of Science, 6-3-1 Niijuku, Katsushika, Tokyo 125-8585 (Japan)

    2014-10-27

    The increasing need for nanodevices has necessitated a better understanding of the electronic transport behavior of nanomaterials. We therefore theoretically examine the AC transport properties of metallic carbon nanotubes with randomly distributed impurities. We find that the long-range impurity scattering increases the emittance, but does not affect the DC conductance. The estimated dwell time of electrons increases with the potential amplitudes. That is, multiple scattering by the impurities increases the kinetic inductance in proportion to the dwell time, which eventually increases the emittance. We believe that our findings can contribute significantly to nanodevice development.

  6. Germanium blocked impurity band infrared detectors

    SciTech Connect (OSTI)

    Rossington, C.S.; Haller, E.E.

    1988-08-01

    Germanium blocked impurity band (BIB) photoconductors have been fabricated and characterized for responsivity, dark current, and noise equivalent power. BIB photoconductors theoretically provide an extension of the spectral response, a reduction in sensitivity to cosmic radiation and a reduction in noise characteristics compared with conventional photoconductors. Silicon BIB detectors have been successfully developed by researchers at Rockwell International, which do indeed meet their theoretical potential. In the proper configuration, these same Si BIB detectors are capable of continuous detection of individual photons in the wavelength range from 0.4 to 28 ..mu..m. Until the BIB concept was developed, detection of individual photons was only possible with photomultiplier tubes which detected visible light. Due to the successes of the Si BIB detectors, it seemed natural to extend this concept to Ge detectors, which would then allow an extension of the spectral response over conventional Ge detectors from /approximately/100 ..mu..m to /approximately/200 ..mu..m. 8 refs., 2 figs.

  7. Extraction of trace metals from fly ash

    DOE Patents [OSTI]

    Blander, Milton; Wai, Chien M.; Nagy, Zoltan

    1984-01-01

    A process for recovering silver, gallium and/or other trace metals from a fine grained industrial fly ash associated with a process for producing phosphorous, the fly ash having a silicate base and containing surface deposits of the trace metals as oxides, chlorides or the like, with the process being carried out by contacting the fly ash with AlCl.sub.3 in an alkali halide melt to react the trace metals with the AlCl.sub.3 to form compositions soluble in the melt and a residue containing the silicate and aluminum oxide or other aluminum precipitate, and separating the desired trace metal or metals from the melt by electrolysis or other separation techniques.

  8. Extraction of trace metals from fly ash

    DOE Patents [OSTI]

    Blander, M.; Wai, C.M.; Nagy, Z.

    1983-08-15

    A process is described for recovering silver, gallium and/or other trace metals from a fine grained industrial fly ash associated with a process for producing phosphorous. The fly ash has a silicate base and contains surface deposits of the trace metals as oxides, chlorides or the like. The process is carried out by contacting the fly ash with AlCl/sub 3/ in an alkali halide melt to react the trace metals with the AlCl/sub 3/ to form compositions soluble in the melt and a residue containing the silicate and aluminum oxide or other aluminum precipitate, and separating the desired trace metal or metals from the melt by electrolysis or other separation techniques.

  9. Correlation between the critical viscosity and ash fusion temperatures of coal gasifier ashes

    SciTech Connect (OSTI)

    Hsieh, Peter Y.; Kwong, Kyei-Sing; Bennett, James

    2015-09-27

    Coal gasification yields synthesis gas, an important intermediate in chemical manufacturing. It is also vital to the production of liquid fuels through the Fischer-Tropsch process and electricity in Integrated Gasification Combined Cycle power generation. Minerals naturally present in coal become molten in entrained-flow slagging gasifiers. Molten coal ash slag penetrates and dissolves refractory bricks, leading to costly plant shutdowns. The extent of coal ash slag penetration and refractory brick dissolution depends on the slag viscosity, the gasification temperature, and the composition of slag and bricks. Here, we measured the viscosity of several synthetic coal ash slags with a high-temperature rotary viscometer and their ash fusion temperatures through optical image analysis. We made all measurements in a carbon monoxide-carbon dioxide reducing atmosphere that approximates coal gasification conditions. Empirical correlation models based on ash fusion temperatures were used to calculate critical viscosity temperatures based on the coal ash compositions. These values were then compared with those obtained from thermodynamic phase-transition models. Finally, an understanding of slag viscosity as a function of ash composition is important to reducing refractory wear in slagging coal gasifiers, which would help to reduce the cost and environmental impact of coal for chemical and electricity production.

  10. Uncovering Fundamental Ash-Formation Mechanisms and Potential...

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

    Results illustrate ash particle growth and formation pathways, and influence of lubricant chemistry and exhaust conditions on fundamental ash properties deer12kamp.pdf (9.21 MB) ...

  11. Recovery Act Workers Complete Environmental Cleanup of Coal Ash...

    Office of Environmental Management (EM)

    Site (SRS) recently cleaned up a 17- acre basin containing coal ash residues from Cold War ... Recovery Act Workers Complete Environmental Cleanup of Coal Ash Basin U.S. Depar tment of ...

  12. Market assessment and technical feasibility study of PFBC ash use

    SciTech Connect (OSTI)

    Smith, V.E.; Bland, A.E.; Brown, T.H.; Georgiou, D.N.; Wheeldon, J.

    1994-10-01

    The overall objectives of this study are to determine the market potential and the technical feasibility of using PFBC ash in high volume ash use applications. The information will be of direct use to the utility industry in assessing the economics of PFBC power generation in light of ash disposal avoidance through ash marketing. In addition, the research is expected to result in the generation of generic data on the use of PFBC ash that could lead to novel processing options and procedures. The specific objectives of the proposed research and demonstration effort are: Define resent and future market potential of PFBC ash for a range of applications (Phase I); assess the technical feasibility of PFBC ash use in construction, civil engineering and agricultural applications (Phase II); and demonstrate the most promising of the market and ash use options in full-scale field demonstrations (Phase III).

  13. High carbon fly ash finds uses in highway construction

    SciTech Connect (OSTI)

    Wen, H.; Patton, R.

    2008-07-01

    The beneficial use of high carbon fly ash in a highway construction project is discussed. The fly ash also had a relatively high content of mercury and some other heavy metals. 1 fig., 4 photos.

  14. Eco-friendly fly ash utilization: potential for land application

    SciTech Connect (OSTI)

    Malik, A.; Thapliyal, A.

    2009-07-01

    The increase in demand for power in domestic, agricultural, and industrial sectors has increased the pressure on coal combustion and aggravated the problem of fly ash generation/disposal. Consequently the research targeting effective utilization of fly ash has also gained momentum. Fly ash has proved to be an economical substitute for expensive adsorbents as well as a suitable raw material for brick manufacturing, zeolite synthesis, etc. Fly ash is a reservoir of essential minerals but is deficient in nitrogen and phosphorus. By amending fly ash with soil and/or various organic materials (sewage sludge, bioprocess materials) as well as microbial inoculants like mycorrhizae, enhanced plant growth can be realized. Based on the sound results of large scale studies, fly ash utilization has grown into prominent discipline supported by various internationally renowned organizations. This paper reviews attempts directed toward various utilization of fly ash, with an emphasis on land application of organic/microbial inoculants amended fly ash.

  15. Utilization of blended fluidized bed combustion (FBC) ash and pulverized coal combustion (PCC) fly ash in geopolymer

    SciTech Connect (OSTI)

    Chindaprasirt, Prinya; Rattanasak, Ubolluk

    2010-04-15

    In this paper, synthesis of geopolymer from fluidized bed combustion (FBC) ash and pulverized coal combustion (PCC) fly ash was studied in order to effectively utilize both ashes. FBC-fly ash and bottom ash were inter-ground to three different finenesses. The ashes were mixed with as-received PCC-fly ash in various proportions and used as source material for synthesis of geopolymer. Sodium silicate (Na{sub 2}SiO{sub 3}) and 10 M sodium hydroxide (NaOH) solutions at mass ratio of Na{sub 2}SiO{sub 3}/NaOH of 1.5 and curing temperature of 65 deg. C for 48 h were used for making geopolymer. X-ray diffraction (XRD), scanning electron microscopy (SEM), degree of reaction, and thermal gravimetric analysis (TGA) were performed on the geopolymer pastes. Compressive strength was also tested on geopolymer mortars. The results show that high strength geopolymer mortars of 35.0-44.0 MPa can be produced using mixture of ground FBC ash and as-received PCC-fly ash. Fine FBC ash is more reactive and results in higher degree of reaction and higher strength geopolymer as compared to the use of coarser FBC ash. Grinding increases reactivity of ash by means of increasing surface area and the amount of reactive phase of the ash. In addition, the packing effect due to fine particles also contributed to increase in strength of geopolymers.

  16. Using fly ash to mitigate explosions

    SciTech Connect (OSTI)

    Taulbee, D.

    2008-07-01

    In 2005 the University of Kentucky's Center for Applied Energy Research was given funding to evaluate the use of coal combustion by-products (CCBs) to reduce the explosive potential of ammonium nitrate (AN) fertilizers. Fly ash C (FAC), fly ash F (FAF) and flue gas desulfurization by-product (FGD) were evaluated. It was found that applying a CCB coating to the AN particles at concentrations of 5 wt% or greater prevented the AN explosion from propagating. The article reports on results so far and outlines further work to be done. 6 figs.

  17. Fly Ash Characteristics and Carbon Sequestration Potential

    SciTech Connect (OSTI)

    Palumbo, Anthony V.; Amonette, James E.; Tarver, Jana R.; Fagan, Lisa A.; McNeilly, Meghan S.; Daniels, William L.

    2007-07-20

    Concerns for the effects of global warming have lead to an interest in the potential for inexpensive methods to sequester carbon dioxide (CO2). One of the proposed methods is the sequestration of carbon in soil though the growth of crops or forests.4,6 If there is an economic value placed on sequestration of carbon dioxide in soil there may be an an opportunity and funding to utilize fly ash in the reclamation of mine soils and other degraded lands. However, concerns associated with the use of fly ash must be addressed before this practice can be widely adopted. There is a vast extent of degraded lands across the world that has some degree of potential for use in carbon sequestration. Degraded lands comprise nearly 2 X 109 ha of land throughout the world.7 Although the potential is obviously smaller in the United States, there are still approximately 4 X 106 ha of degraded lands that previously resulted from mining operations14 and an additional 1.4 X 108 ha of poorly managed lands. Thus, according to Lal and others the potential is to sequester approximately 11 Pg of carbon over the next 50 years.1,10 The realization of this potential will likely be dependent on economic incentives and the use of soil amendments such as fly ash. There are many potential benefits documented for the use of fly ash as a soil amendment. For example, fly ash has been shown to increase porosity, water-holding capacity, pH, conductivity, and dissolved SO42-, CO32-, HCO3-, Cl- and basic cations, although some effects are notably decreased in high-clay soils.8,13,9 The potential is that these effects will promote increased growth of plants (either trees or grasses) and result in greater carbon accumulation in the soil than in untreated degraded soils. This paper addresses the potential for carbon sequestration in soils amended with fly ash and examines some of the issues that should be considered in planning this option. We describe retrospective studies of soil carbon accumulation on

  18. Utilization options for fly ash, bottom ash, and slag in Eastern Europe

    SciTech Connect (OSTI)

    Manz, O.E.

    1995-12-01

    Since 1967, at least six ash utilization symposiums have been held in the United States, with papers presented by several European authors on the utilization of coal by-products in Eastern Europe. There is currently over 80,000 megawatts of installed coal-fired capacity available in that region. Unfortunately, of the 117,778,000 tonnes of fly ash, bottom ash, and slag produced in Eastern Europe in 1989, only 13% was utilized. This paper outlines the research and levels and kinds of coal by-product utilization taking place in Eastern Europe since the late 1960s.

  19. Impact of Fission Products Impurity on the Plutonium Content...

    Office of Scientific and Technical Information (OSTI)

    Impact of Fission Products Impurity on the Plutonium Content of Metal- and Oxide- Fuels in Sodium Cooled Fast Reactors Citation Details In-Document Search Title: Impact of Fission ...

  20. Accurate Detection of Impurities in Hydrogen Fuel at Lower Cost...

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

    Hydrogen and Fuel Cell Hydrogen and Fuel Cell Find More Like This Return to Search Accurate Detection of Impurities in Hydrogen Fuel at Lower Cost Advancing the science of fuel ...

  1. Evolution of quasiparticle states with and without a Zn impurity...

    Office of Scientific and Technical Information (OSTI)

    Title: Evolution of quasiparticle states with and without a Zn impurity in doped 122 iron pnictides Authors: Pan, Lihua ; Li, Jian ; Tai, Yuan-Yen ; Graf, Matthias J. ; Zhu, ...

  2. Fast Diffusion of Native Defects and Impurities in Perovskite...

    Office of Scientific and Technical Information (OSTI)

    in Perovskite Solar Cell Material CH 3 NH 3 PbI 3 Citation Details In-Document Search Title: Fast Diffusion of Native Defects and Impurities in Perovskite Solar Cell Material CH ...

  3. Uncovering Fundamental Ash-Formation Mechanisms and Potential Means to

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

    Control the Impact on DPF Performance and Engine Efficiency | Department of Energy Uncovering Fundamental Ash-Formation Mechanisms and Potential Means to Control the Impact on DPF Performance and Engine Efficiency Uncovering Fundamental Ash-Formation Mechanisms and Potential Means to Control the Impact on DPF Performance and Engine Efficiency Results illustrate ash particle growth and formation pathways, and influence of lubricant chemistry and exhaust conditions on fundamental ash

  4. Literature review of metal corrosion sensitivity in high temperature, high impurity hot cell atmospheres

    SciTech Connect (OSTI)

    Eberle, C.S.

    1997-09-01

    The pyrochemical conditions of spent nuclear fuel for the purpose of final disposal is being demonstrated at Argonne National Laboratory (ANL). One aspect of this program is to develop a lithium preprocessing stage for the Fuel Conditioning Facility (FCF). One of the design considerations under investigation in this program is the system`s corrosion response in the presence of irradiated commercial fuel as well as atmospheric impurities. Static corrosion coupon tests have been completed which demonstrate the potential corrosivity of the salt matrix in a worse case environment as well as provide a boundary for allowable impurities in the system during operation. The literature concerning corrosion of either fused salts or molten metals consistently emphasizes three similar features which are common to both systems: (1) the overall corrosion rate is strongly dependent on temperature, impurity concentration and flow velocity; (2) many different mechanisms can be involved in a specific corrosion process; and (3) corrosion rates will significantly increase as all three of these independent variables are increased. The qualitative and quantitative understanding of these corrosion results is important for this spent fuel program since all of these variables will increase as the process scale increases. The purpose of this work was to determine if any data existed which could provide a quantitative expectation for corrosion rates of refractory metals in a lithium chloride salt bath.

  5. Impurity control and corrosion resistance of magnesium-aluminum alloy

    SciTech Connect (OSTI)

    Liu, M. [GM China Lab] [GM China Lab; Song, GuangLing [ORNL] [ORNL

    2013-01-01

    The corrosion resistance of magnesium alloys is very sensitive to the contents of impurity elements such as iron. In this study, a series of diecast AXJ530 magnesium alloy samples were prepared with additions of Mn and Fe. Through a comprehensive phase diagram calculation and corrosion evaluation, the mechanisms for the tolerance limit of Fe in magnesium alloy are discussed. This adds a new dimension to control the alloying impurity in terms of alloying composition design and casting conditions.

  6. Effects of Impurities of Fuel Cell Performance and Durability | Department

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

    of Energy of Fuel Cell Performance and Durability Effects of Impurities of Fuel Cell Performance and Durability This presentation, which focuses on fuel cell performance and durability, was given by Trent Molter of the University of Connecticut at a February 2007 meeting on new fuel cell projects. new_fc_molter_uconn.pdf (680.96 KB) More Documents & Publications The Effect of Airborne Contaminants on Fuel Cell Performance & Durability Effects of Impurities on Fuel Cell Performance

  7. Effects of Impurities on Fuel Cell Performance and Durability | Department

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

    of Energy on Fuel Cell Performance and Durability Effects of Impurities on Fuel Cell Performance and Durability This presentation, which focuses on fuel cell performance and durability, was given by James Goodwin of Clemson Univeristy at a February 2007 meeting on new fuel cell projects. new_fc_goodwin_clemson.pdf (322.34 KB) More Documents & Publications Acid Doped Membranes for High Temperature PEMFC Biogas Impurities and Cleanup for Fuel Cells Integration of Non-Traditional Membranes

  8. Engineering Metal Impurities in Multicrystalline Silicon Solar Cells

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

    Engineering Metal Impurities in Multicrystalline Silicon Solar Cells Engineering Metal Impurities in Multicrystalline Silicon Solar Cells Print Wednesday, 26 October 2005 00:00 Transition metals are one of the main culprits in degrading the efficiency of multicrystalline solar cells. With a suite of x-ray microprobe techniques, a multi-institutional collaboration led by researchers from the University of California, Berkeley, and Berkeley Lab studied the distribution of metal clusters in a

  9. On the state of Mn impurity implanted in Si

    SciTech Connect (OSTI)

    Orlov, A. F.; Bublik, V. T.; Vdovin, V. I.; Agafonov, Yu. A.; Balagurov, L. A.; Zinenko, V. I.; Kulemanov, I. V.; Shcherbachev, K. D.

    2009-07-15

    The state of manganese impurity in implanted silicon at implantation doses of up to 5 x 10{sup 16} cm{sup -2} has been investigated by X-ray diffraction and transmission electron microscopy. It is established that, after short-term vacuum annealing at 850{sup o}C, most of the implanted manganese impurities are in microinclusions up to 20 nm in size formed by a tetragonal silicide phase of the Mn{sub 15}Si{sub 26} type.

  10. Oil ash corrosion; A review of utility boiler experience

    SciTech Connect (OSTI)

    Paul, L.D. ); Seeley, R.R. )

    1991-02-01

    In this paper a review of experience with oil ash corrosion is presented along with current design practices used to avoid excessive tube wastage. Factors influencing oil ash corrosion include fuel chemistry, boiler operation, and boiler design. These factors are interdependent and determine the corrosion behavior in utility boilers. Oil ash corrosion occurs when vanadium-containing ash deposits on boiler tube surfaces become molten. These molten ash deposits dissolve protective oxides and scales causing accelerated tube wastage. Vanadium is the major fuel constituent responsible for oil ash corrosion. Vanadium reacts with sodium, sulfur, and chlorine during combustion to produce lower melting temperature ash compositions, which accelerate tube wastage. Limiting tube metal temperatures will prevent ash deposits from becoming molten, thereby avoiding the onset of oil ash corrosion. Tube metal temperatures are limited by the use of a parallel stream flow and by limiting steam outlet temperatures. Operating a boiler with low excess air has helped avoid oil ash corrosion by altering the corrosive combustion products. Air mixing and distribution are essential to the success of this palliative action. High chromium alloys and coatings form more stable protective scaled on tubing surfaces, which result in lower oil ash corrosion rates. However, there is not material totally resistant to oil ash corrosion.

  11. Utilization of CFB fly ash for construction applications

    SciTech Connect (OSTI)

    Conn, R.E.; Sellakumar, K.; Bland, A.E.

    1999-07-01

    Disposal in landfills has been the most common means of handling ash in circulating fluidized bed (CFB) boiler power plants. Recently, larger CFB boilers with generating capacities up to 300 MWe are currently being planned, resulting in increased volumes and disposal cost of ash by-product. Studies have shown that CFB ashes do not pose environmental concerns that should significantly limit their potential utilization. Many uses of CFB ash are being investigated by Foster Wheeler, which can provide more cost-effective ash management. Construction applications have been identified as one of the major uses for CFB ashes. Typically, CFB ash cannot be used as a cement replacement in concrete due to its unacceptably high sulfur content. However, CFB ashes can be used for other construction applications that require less stringent specifications including soil stabilization, road base, structural fill, and synthetic aggregate. In this study, potential construction applications were identified for fly ashes from several CFB boilers firing diverse fuels such as petroleum coke, refuse derived fuel (RDF) and coal. The compressive strength of hydrated fly ashes was measured in order to screen their potential for use in various construction applications. Based on the results of this work, the effects of both ash chemistry and carbon content on utilization potential were ascertained. Actual beneficial uses of ashes evaluated in this study are also discussed.

  12. Shallow-deep transitions of impurities in semiconductor nanostructures

    SciTech Connect (OSTI)

    Ranjan, V.; Singh, Vijay A.

    2001-06-01

    We study the hydrogenic impurity in a quantum dot (QD). We employ the effective mass theory with realistic barrier and variable effective mass. The model is simple, but it predicts features not previously observed. We observe that the shallow hydrogenic impurity becomes deeper as the dot size (R) is reduced and with further reduction of the dot size it becomes shallow and at times resonant with the conduction band. Such a shallow-deep (SHADE) transition is investigated and a critical size in terms of the impurity Bohr radius (a{sub I}{sup *}) is identified. A relevant aspect of a QD is reduction in the dielectric constant, {epsilon}, as its size decreases. Employing a size dependent {epsilon}(R), we demonstrate that the impurity level gets exceptionally deep in systems for which a{sub I}{sup *} is small. Thus, carrier {open_quotes}freeze out{close_quotes} is a distinct possibility in a wide class of materials such as ZnS, CdS, etc. The behavior of the impurity level with dot size is understood on the basis of simple scaling arguments. Calculations are presented for III{endash}V (AlGaAs) and II{endash}VI (ZnS, CdS) QDs. We speculate that the deepening of the impurity level is related to the high luminescence efficiency of QDs. It is suggested that quantum dots offer an opportunity for defect engineering. {copyright} 2001 American Institute of Physics.

  13. Local spectroscopy of a kondo impurity: Co on Au(111)

    SciTech Connect (OSTI)

    Madhavan, V.; Chen, W.; Jamneala, T.; Crommie, M.F.; Wingreen, N.S.

    2001-07-15

    We present a detailed study of the local electronic properties of the Kondo system formed from cobalt adatoms deposited onto Au(111) at a temperature of 6.6 K. Cryogenic scanning-tunneling spectroscopy was used to observe impurity-induced resonances at the Fermi energy and at the Au(111) surface-state band edge. The line shape of the Fermi-energy resonance, identified as a Kondo resonance, is observed to vary with lateral position from the impurity center and with impurity binding position on the reconstructed Au(111) surface. Little vertical dependence is seen in the resonance line shape for positions above the center of the impurity. Interaction effects between Kondo impurities are observed to remain small as cobalt coverage is increased up to 1 ML on the gold surface. The Kondo resonance is shown theoretically to be a member of a general class of Fano resonances arising from the interaction of a discrete impurity state with a conduction-electron continuum. The asymmetric line shape of the resonance thus reflects quantum interference between the d orbital and continuum conduction electron channels, as well as their coupling to the STM tip.

  14. 488-D Ash Basin Vegetative Cover Treatibility Study

    SciTech Connect (OSTI)

    Barton, Christopher; Marx, Don; Blake, John; Adriano, Domy; Koo, Bon-Jun; Czapka, Stephen

    2003-01-01

    The 488-D Ash Basin is an unlined containment basin that received ash and coal reject material from the operation of a powerhouse at the USDOE's Savannah River Site, SC. They pyretic nature of the coal rejects has resulted in the formation of acidic drainage (AD), which has contributed to groundwater deterioration and threatens biota in down gradient wetlands. Establishment of a vegetative cover was examined as a remedial alternative for reducing AD generation within this system by enhanced utilization of rainwater and subsequent non-point source water pollution control. The low nutrient content, high acidity, and high salinity of the basin material, however, was deleterious to plant survivability. As such, studies to identify suitable plant species and potential adaptations, and pretreatment techniques in the form of amendments, tilling, and/or chemical stabilization were needed. A randomized block design consisting of three subsurface treatments (blocks) and five duplicated surface amendments (treatments) was developed. One hundred inoculated pine trees were planted on each plot. Herbaceous species were also planted on half of the plots in duplicated 1-m2 beds. After two growing seasons, deep ripping, subsurface amendments and surface covers were shown to be essential for the successful establishment of vegetation on the basin. This is the final report of the study.

  15. Quantification of the degree of reaction of fly ash

    SciTech Connect (OSTI)

    Ben Haha, M.; De Weerdt, K.; Lothenbach, B.

    2010-11-15

    The quantification of the fly ash (FA) in FA blended cements is an important parameter to understand the effect of the fly ash on the hydration of OPC and on the microstructural development. The FA reaction in two different blended OPC-FA systems was studied using a selective dissolution technique based on EDTA/NaOH, diluted NaOH solution, the portlandite content and by backscattered electron image analysis. The amount of FA determined by selective dissolution using EDTA/NaOH is found to be associated with a significant possible error as different assumptions lead to large differences in the estimate of FA reacted. In addition, at longer hydration times, the reaction of the FA is underestimated by this method due to the presence of non-dissolved hydrates and MgO rich particles. The dissolution of FA in diluted NaOH solution agreed during the first days well with the dissolution as observed by image analysis. At 28 days and longer, the formation of hydrates in the diluted solutions leads to an underestimation. Image analysis appears to give consistent results and to be most reliable technique studied.

  16. Phase relationship in coal ash corrosion products

    SciTech Connect (OSTI)

    Kalmanovitch, D.

    1996-12-31

    The corrosion of heat transfer surfaces in coal-fired utility boilers is a major concern to the efficient operation of these units. Despite the importance of the corrosion there has been limited research on the relationship between the ash components on the tube surface and the interactions and reactions between the various components and the steel surface. Mechanisms such as molten phase corrosion, sulfidation, and high temperature oxidation have been identified as leading to extensive wastage oftube metal. However, while the corrosion process can be identified using techniques such as metallography and x-ray diffraction there is limited insight into the role ofthe coal mineralogy and ash deposits on the surface in the corrosion process. This paper describes research into the formation of molten or sernimolten phases within ash deposits which are associated with corrosion of superheater and reheater fireside surfaces. For example, the phases potassium pyrosulfate (K{sub 2}S{sub 2}O{sub 7}) and potassium aluminum sulfate (K{sub 2}Al{sub 2}SO{sub 7}) have been determined by x-ray diffraction to be present in deposits where fireside corrosion has occurred. However, both these phases are not directly derived from coal minerals or the common matrix observed in ash deposits. The examination of the reactions and interactions within deposits which result in the formation of these and other phases associated with corrosion will be discussed in the paper.

  17. Assessing ecological risks to the fish community from residual coal fly ash in Watts Bar Reservoir, Tennessee

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

    Rigg, David K.; Wacksman, Mitch N.; Iannuzzi, Jacqueline; Baker, Tyler F.; Adams, Marshall; Greeley, Jr., Mark Stephen

    2014-12-18

    For this research, extensive site-specific biological and environmental data were collected to support an evaluation of risks to the fish community in Watts Bar Reservoir from residual ash from the December 2008 Tennessee Valley Authority (TVA) Kingston ash release. This paper describes the approach used and results of the risk assessment for the fish community, which consists of multiple measurement endpoints (measures of exposure and effects) for fish. The lines of evidence included 1) comparing postspill annual fish community assessments with nearby prespill data and data from other TVA reservoirs, 2) evaluating possible effects of exposures of fish eggs andmore » larval fish to ash in controlled laboratory toxicity tests, 3) evaluating reproductive competence of field-exposed fish, 4) assessing individual fish health through physical examination, histopathology, and blood chemistry, 5) comparing fish tissue concentrations with literature-based critical body residues, and 6) comparing concentrations of ash-related contaminants in surface waters with US Environmental Protection Agency's (USEPA) Ambient Water Quality Standards for Fish and Aquatic Life. These measurement endpoints were treated as independent lines of evidence that were integrated into an overall weight-of-evidence estimate of risk to the fish community. Collectively, the data and analysis presented here indicate that ash and ash-related constituents pose negligible risks to the fish communities in Watts Bar Reservoir. This conclusion contradicts the predictions by some researchers immediately following the ash release of devastating effects on the aquatic ecology of Watts Bar Reservoir. The information presented in this article reaffirms the wisdom of carefully evaluating the evidence before predicting probable ecological effects of a major event such as the TVA Kingston ash release. Lastly, this study demonstrates that a thorough and detailed investigation using multiple measurement endpoints

  18. Assessing ecological risks to the fish community from residual coal fly ash in Watts Bar Reservoir, Tennessee

    SciTech Connect (OSTI)

    Rigg, David K.; Wacksman, Mitch N.; Iannuzzi, Jacqueline; Baker, Tyler F.; Adams, Marshall; Greeley, Jr., Mark Stephen

    2014-12-18

    For this research, extensive site-specific biological and environmental data were collected to support an evaluation of risks to the fish community in Watts Bar Reservoir from residual ash from the December 2008 Tennessee Valley Authority (TVA) Kingston ash release. This paper describes the approach used and results of the risk assessment for the fish community, which consists of multiple measurement endpoints (measures of exposure and effects) for fish. The lines of evidence included 1) comparing postspill annual fish community assessments with nearby prespill data and data from other TVA reservoirs, 2) evaluating possible effects of exposures of fish eggs and larval fish to ash in controlled laboratory toxicity tests, 3) evaluating reproductive competence of field-exposed fish, 4) assessing individual fish health through physical examination, histopathology, and blood chemistry, 5) comparing fish tissue concentrations with literature-based critical body residues, and 6) comparing concentrations of ash-related contaminants in surface waters with US Environmental Protection Agency's (USEPA) Ambient Water Quality Standards for Fish and Aquatic Life. These measurement endpoints were treated as independent lines of evidence that were integrated into an overall weight-of-evidence estimate of risk to the fish community. Collectively, the data and analysis presented here indicate that ash and ash-related constituents pose negligible risks to the fish communities in Watts Bar Reservoir. This conclusion contradicts the predictions by some researchers immediately following the ash release of devastating effects on the aquatic ecology of Watts Bar Reservoir. The information presented in this article reaffirms the wisdom of carefully evaluating the evidence before predicting probable ecological effects of a major event such as the TVA Kingston ash release. Lastly, this study demonstrates that a thorough and detailed investigation using multiple measurement endpoints is needed

  19. Non-equilibrium STLS approach to transport properties of single impurity Anderson model

    SciTech Connect (OSTI)

    Rezai, Raheleh Ebrahimi, Farshad

    2014-04-15

    In this work, using the non-equilibrium Keldysh formalism, we study the effects of the electronelectron interaction and the electron-spin correlation on the non-equilibrium Kondo effect and the transport properties of the symmetric single impurity Anderson model (SIAM) at zero temperature by generalizing the self-consistent method of Singwi, Tosi, Land, and Sjolander (STLS) for a single-band tight-binding model with Hubbard type interaction to out of equilibrium steady-states. We at first determine in a self-consistent manner the non-equilibrium spin correlation function, the effective Hubbard interaction, and the double-occupancy at the impurity site. Then, using the non-equilibrium STLS spin polarization function in the non-equilibrium formalism of the iterative perturbation theory (IPT) of Yosida and Yamada, and Horvatic and Zlatic, we compute the spectral density, the currentvoltage characteristics and the differential conductance as functions of the applied bias and the strength of on-site Hubbard interaction. We compare our spectral densities at zero bias with the results of numerical renormalization group (NRG) and depict the effects of the electronelectron interaction and electron-spin correlation at the impurity site on the aforementioned properties by comparing our numerical result with the order U{sup 2} IPT. Finally, we show that the obtained numerical results on the differential conductance have a quadratic universal scaling behavior and the resulting Kondo temperature shows an exponential behavior. -- Highlights: We introduce for the first time the non-equilibrium method of STLS for Hubbard type models. We determine the transport properties of SIAM using the non-equilibrium STLS method. We compare our results with order-U2 IPT and NRG. We show that non-equilibrium STLS, contrary to the GW and self-consistent RPA, produces the two Hubbard peaks in DOS. We show that the method keeps the universal scaling behavior and correct exponential behavior

  20. Stabilizing soft fine-grained soils with fly ash

    SciTech Connect (OSTI)

    Edil, T.B.; Acosta, H.A.; Benson, C.H.

    2006-03-15

    The objective of this study was to evaluate the effectiveness of self-cementing fly ashes derived from combustion of subbituminous coal at electric power plants for stabilization of soft fine-grained soils. California bearing ratio (CBR) and resilient modulus (M{sub r}) tests were conducted on mixtures prepared with seven soft fine-grained soils (six inorganic soils and one organic soil) and four fly ashes. The soils were selected to represent a relatively broad range of plasticity, with plasticity indices ranging between 15 and 38. Two of the fly ashes are high quality Class C ashes (per ASTM C 618) that are normally used in Portland cement concrete. The other ashes are off-specification ashes, meaning they do not meet the Class C or Class F criteria in ASTM C 618. Tests were conducted on soils and soil-fly ash mixtures prepared at optimum water content (a standardized condition), 7% wet of optimum water content (representative of the typical in situ condition in Wisconsin), and 9-18% wet of optimum water content (representative of a very wet in situ condition). Addition of fly ash resulted in appreciable increases in the CBR and M{sub r} of the inorganic soils. For water contents 7% wet of optimum, CBRs of the soils alone ranged between 1 and 5. Addition of 10% fly ash resulted in CBRs ranging between 8 and 17, and 18% fly ash resulted in CBRs between 15 and 31. Similarly, M{sub r} of the soil alone ranged between 3 and 15 MPa at 7% wet of optimum, whereas addition of 10% fly ash resulted in M{sub r} between 12 and 60 MPa and 18% fly ash resulted in M{sub r} between 51 and 106 MPa. In contrast, except for one fly ash, addition of fly ash generally had little effect on CBR or M{sub r} of the organic soil.

  1. Research in Hydrogen Passivation of Defects and Impurities in Silicon: Final Report, 2 May 2000-2 July 2003

    SciTech Connect (OSTI)

    Ashok, S.

    2004-12-01

    This subcontract report describes hydrogenating Si samples by different methods such as low-energy implantation, electron cyclotron resonance (ECR) plasma, and thermal diffusion. The samples were provided through NREL. The experimental work, carried out at Penn State, involved the study of hydrogen interaction with defects, trapping, migration, and formation of complexes. The principal vehicle for the latter study was ion implantation, and the intent to understand mechanisms of defect passivation and activation by hydrogen. NREL implemented a study of hydrogen passivation of impurities and defects in silicon solar cells. The work included theoretical and experimental components performed at different universities. The theoretical studies consisted of the calculation of the structure and parameters related to hydrogen diffusion and interactions of hydrogen with transition-metal impurities in silicon. Experimental studies involved measurements of hydrogen and hydrogen-impurity complexes, and diffusion properties of various species of hydrogen in Si. The experimental work at Penn State included introduction of hydrogen in a variety of PV Si by ECR plasma, low-energy ion implantation, and thermal diffusion. The specific tasks were the evaluation of hydrogen interaction with defects engineered by ion implantation; defect passivation, activation, and migration in hydrogenated Si under thermal anneal; and electrical activity of hydrogen-impurity complexes. Electrical characterization entailed I-V and C-V measurements, spreading resistance, and deep-level transient spectroscopy (DLTS).

  2. Fly ash and concrete: a study determines whether biomass, or coal co-firing fly ash, can be used in concrete

    SciTech Connect (OSTI)

    Wang, Shuangzhen; Baxter, Larry

    2006-08-01

    Current US national standards for using fly ash in concrete (ASTM C618) state that fly ash must come from coal combustion, thus precluding biomass-coal co-firing fly ash. The co-fired ash comes from a large and increasing fraction of US power plants due to rapid increases in co-firing opportunity fuels with coal. The fly ashes include coal fly ash, wood fly ash from pure wood combustion, biomass and coal co-fired fly ash SW1 and SW2. Also wood fly ash is blended with Class C or Class F to produce Wood C and Wood E. Concrete samples were prepared with fly ash replacing cement by 25%. All fly ash mixes except wood have a lower water demand than the pure cement mix. Fly ashes, either from coal or non coal combustion, increase the required air entraining agent (AEA) to meet the design specification of the mixes. If AEA is added arbitrarily without considering the amount or existence of fly ash results could lead to air content in concrete that is either too low or too high. Biomass fly ash does not impact concrete setting behaviour disproportionately. Switch grass-coal co-fired fly ash and blended wood fly ash generally lie within the range of pure coal fly ash strength. The 56 day flexure strength of all the fly ash mixes is comparable to that of the pure cement mix. The flexure strength from the coal-biomass co-fired fly ash does not differ much from pure coal fly ash. All fly ash concrete mixes exhibit lower chloride permeability than the pure cement mixes. In conclusion biomass coal co-fired fly ash perform similarly to coal fly ash in fresh and hardened concrete. As a result, there is no reason to exclude biomass-coal co-fired fly ash in concrete.

  3. Blocked impurity band hybrid infrared focal plane arrays for astronomy

    SciTech Connect (OSTI)

    Reynolds, D.B.; Seib, D.H.; Stetson, S.B.; Herter, T.; Rowlands, N.; Schoenwald, J.

    1989-02-01

    High-performance infrared hybrid focal plane arrays using 10 x 50 element Si:As Blocked-Impurity-Band (BIB) detectors (cut-off wavelength = 28 ..mu..m) and matching switched MOSFET multiplexers have been developed and characterized for space astronomy. Use of impurity band conduction technology provides detectors which are nuclear radiation hard and free of the many anomalies associated with conventional silicon photoconductive detectors. Emphasis in this paper is on recent advances in detector material quality which have led to significantly improved detector and hybrid characteristics. Results demonstrating increase quantum efficiency (particular at short wavelength infrared), obtained by varying the Blocked-Impurity-Band detector properties (infrared active layer thickness and arsenic doping profile), are summarized. Read noise and dark current for different temperatures have been measured and are also described. The hybrid array performance achieved clearly demonstrates that BIB detectors are well suited for use in astronomical instrumentation.

  4. Removal of fluoride impurities from UF.sub.6 gas

    DOE Patents [OSTI]

    Beitz, James V.

    1985-01-01

    A method of purifying a UF.sub.6 gas stream containing one or more metal fluoride impurities composed of a transuranic metal, transition metal or mixtures thereof, is carried out by contacting the gas stream with a bed of UF.sub.5 in a reaction vessel under conditions where at least one impurity reacts with the UF.sub.5 to form a nongaseous product and a treated gas stream, and removing the treated gas stream from contact with the bed. The nongaseous products are subsequently removed in a reaction with an active fluorine affording agent to form a gaseous impurity which is removed from the reaction vessel. The bed of UF.sub.5 is formed by the reduction of UF.sub.6 in the presence of UV light. One embodiment of the reaction vessel includes a plurality of UV light sources as tubes on which UF.sub.5 is formed.

  5. Removal of fluoride impurities from UF/sub 6/ gas

    DOE Patents [OSTI]

    Beitz, J.V.

    1984-01-06

    A method of purifying a UF/sub 6/ gas stream containing one or more metal fluoride impurities composed of a transuranic metal, transition metal or mixtures thereof, is carried out by contacting the gas stream with a bed of UF/sub 5/ in a reaction vessel under conditions where at least one impurity reacts with the UF/sub 5/ to form a nongaseous product and a treated gas stream, and removing the treated gas stream from contact with the bed. The nongaseous products are subsequently removed in a reaction with an active fluorine affording agent to form a gaseous impurity which is removed from the reaction vessel. The bed of UF/sub 5/ is formed by the reduction of UF/sub 6/ in the presence of uv light. One embodiment of the reaction vessel includes a plurality of uv light sources as tubes on which UF/sub 5/ is formed. 2 figures.

  6. Application of solid ash based catalysts in heterogeneous catalysis

    SciTech Connect (OSTI)

    Shaobin Wang

    2008-10-01

    Solid wastes, fly ash, and bottom ash are generated from coal and biomass combustion. Fly ash is mainly composed of various metal oxides and possesses higher thermal stability. Utilization of fly ash for other industrial applications provides a cost-effective and environmentally friendly way of recycling this solid waste, significantly reducing its environmental effects. On the one hand, due to the higher stability of its major component, aluminosilicates, fly ash could be employed as catalyst support by impregnation of other active components for various reactions. On the other hand, other chemical compounds in fly ash such as Fe{sub 2}O{sub 3} could also provide an active component making fly ash a catalyst for some reactions. In this paper, physicochemical properties of fly ash and its applications for heterogeneous catalysis as a catalyst support or catalyst in a variety of catalytic reactions were reviewed. Fly-ash-supported catalysts have shown good catalytic activities for H{sub 2} production, deSOx, deNOx, hydrocarbon oxidation, and hydrocracking, which are comparable to commercially used catalysts. As a catalyst itself, fly ash can also be effective for gas-phase oxidation of volatile organic compounds, aqueous-phase oxidation of organics, solid plastic pyrolysis, and solvent-free organic synthesis. 107 refs., 4 figs., 2 tabs.

  7. The leaching characteristics of selenium from coal fly ashes

    SciTech Connect (OSTI)

    Wang, T.; Wang, J.; Burken, J.G.; Ban, H.; Ladwig, K.

    2007-11-15

    The leaching characteristics of selenium from several bituminous and subbituminous coal fly ashes under different pH conditions were investigated using batch methods. Results indicated that pH had a significant effect on selenium leaching from bituminous coal ash. The minimum selenium leaching occurred in the pH range between 3 and 4, while the maximum selenium leaching occurred at pH 12. The release of selenium from subbituminous coal ashes was very low for the entire experimental pH range, possibly due to the high content of calcium which can form hydration or precipitation products as a sink for selenium. The adsorption results for different selenium species indicated that Se(VI) was hardly adsorbable on either bituminous coal ashes or subbitumminous coal ashes at any pH. However, Se(I) was highly adsorbed by bituminous coal ashes under acidic pH conditions and was mostly removed by subbitumminous coal ashes across the entire pH range. This result suggests that the majority of selenium released from the tested fly ashes was Se(IV). A speciation-based model was developed to simulate the adsorption of Se(IV) on bituminous coal fly ash, and the pH-independent adsorption constants of HSeO{sup 3-} and SeO{sub 3}{sup 2-} were determined. The modeling approach is useful for understanding and predicting the release process of selenium from fly ash.

  8. Water quality investigation of Kingston Fossil Plant dry ash stacking

    SciTech Connect (OSTI)

    Bohac, C.E.

    1990-04-01

    Changing to a dry ash disposal systems at Kingston Fossil Plant (KFP) raises several water quality issues. The first is that removing the fly ash from the ash pond could alter the characteristics of the ash pond discharge to the river. The second concerns proper disposal of the runoff and possibly leachate from the dry ash stack. The third is that dry ash stacking might change the potential for groundwater contamination at the KFP. This report addresses each of these issues. The effects on the ash pond and its discharge are described first. The report is intended to provide reference material to TVA staff in preparation of environmental review documents for new ash disposal areas at Kingston. Although the investigation was directed toward analysis of dry stacking, considerations for other disposal options are also discussed. This report was reviewed in draft form under the title Assessment of Kingston Fossil Plant Dry Ash Stacking on the Ash Pond and Groundwater Quality.'' 11 refs., 3 figs., 18 tabs.

  9. Helium transport and ash control studies

    SciTech Connect (OSTI)

    Miley, G.H.

    1992-01-01

    The Primary goal of this research is to develop a helium (ash) transport scaling law based on experimental data from devices such as TFTR and JET. To illustrate the importance of this, we have studied ash accumulation effects on ignition requirements using a O-D transport model. Ash accumulation is characterized in the model by the ratio of the helium particle confinement time to the energy confinement time t{sub {alpha}}/t{sub E}. Results show that the ignition window'' shrinks rapidly as t{sub {alpha}}/t{sub E} increases, closing for high t{sub {alpha}}/t{sub E} increases, closing for high t{sub {alpha}}/t{sub E}. A best'' value for t{sub {alpha}}/t{sub E} will ultimately be determined from our scaling law studies. A helium transport scaling law is being sought that expresses the transport coefficients (D{sub {alpha}}, V{sub {alpha}}) as a function of the local plasma parameters. This is necessary for use in transport code calculations, e.g. for BALDUR. Based on experimental data from L-mode plasma operation in TFTR, a scaling law to a power law expression has been obtained using a least-square fit method. It is found that the transport coefficients are strongly affected by the local magnetic field and safety factor q. A preliminary conclusion from this work is that active control of ash buildup must be developed. To study control, we have developed a O-D plasma model which employs a simple pole-placement control model. Some preliminary calculations with this model are presented.

  10. Manufacture of ceramic tiles from fly ash

    DOE Patents [OSTI]

    Hnat, James G.; Mathur, Akshay; Simpson, James C.

    1999-01-01

    The present invention relates to a process for forming glass-ceramic tiles. Fly ash containing organic material, metal contaminants, and glass forming materials is oxidized under conditions effective to combust the organic material and partially oxidize the metallic contaminants and the glass forming materials. The oxidized glass forming materials are vitrified to form a glass melt. This glass melt is then formed into tiles containing metallic contaminants.

  11. Manufacture of ceramic tiles from fly ash

    DOE Patents [OSTI]

    Hnat, J.G.; Mathur, A.; Simpson, J.C.

    1999-08-10

    The present invention relates to a process for forming glass-ceramic tiles. Fly ash containing organic material, metal contaminants, and glass forming materials is oxidized under conditions effective to combust the organic material and partially oxidize the metallic contaminants and the glass forming materials. The oxidized glass forming materials are vitrified to form a glass melt. This glass melt is then formed into tiles containing metallic contaminants. 6 figs.

  12. Eirich technology for the preparation of ashes

    SciTech Connect (OSTI)

    Eirich, G.

    1994-12-31

    The paper describes a mixer manufactured by Maschinenfabrik Gustav Eirich that can be used in the agglomeration of power plant ashes and residues. No matter whether the power plant burns coal, fuel oil, wood, peat, or garbage or whether the power plant plans to dispose or utilize the residue, most flowsheets will contain an agglomeration step. The paper describes some of the uses to which this mixer can be put.

  13. Self-consistent klystron simulations

    SciTech Connect (OSTI)

    Carlsten, B.E.; Tallerico, P.J.

    1985-01-01

    A numerical analysis of large-signal klystron behavior based on general wave-particle interaction theory is presented. The computer code presented is tailored for the minimum amount of complexity needed in klystron simulation. The code includes self-consistent electron motion, space-charge fields, and intermediate and output fields. It also includes use of time periodicity to simplify the problem, accurate representation of the space-charge fields, accurate representation of the cavity standing-wave fields, and a sophisticated particle-pushing routine. In the paper, examples are given that show the effects of cavity detunings, of varying the magnetic field profile, of electron beam asymmetries from the gun, and of variations in external load impedance. 4 refs., 7 figs.

  14. Phase relationships in coal ash corrosion products

    SciTech Connect (OSTI)

    Kalmanovitch, D.

    1996-10-01

    The corrosion of heat transfer surfaces in coal-fired utility boilers is a major concern to the efficient operation of these units. Despite the importance of the corrosion there has been limited research on the relationship between the ash components on the tube surface and the interactions and reactions between the various components and the steel surface. Mechanisms such as molten phase corrosion, sulfidation, and high temperature oxidation have been identified as leading to extensive wastage of tube metal. This paper describes research into the formation of molten or semimolten phases within ash deposits which are associated with corrosion of superheater and reheater fireside surfaces. For example, the phases potassium pyrosulfate (K{sub 2}S{sub 2}O{sub 7}) and potassium aluminum sulfate (K{sub 2}Al{sub 2}SO{sub 7}) have been determined by x-ray diffraction to be present in deposits where fireside corrosion has occurred. However, both these phases are not directly derived from coal minerals or the common matrix observed in ash deposits. The examination of the reactions and interactions within deposits which result a the formation of these and other phases associated with corrosion will be discussed in the paper.

  15. Market assessment of PFBC ash use

    SciTech Connect (OSTI)

    Bland, A. E.; Brown, T. H., Western Research Institute

    1998-01-01

    Pressurized fluidized bed combustion (PFBC) of coal is undergoing demonstration in the United States, as well as throughout the world. American Electric Power`s (AEP`s) bubbling PFBC 70 MWe Tidd demonstration program in Ohio and pilot-scale development at Foster Wheeler Energia Oy 10 MWth circulating PFBC at Karhula, Finland, have demonstrated the advantages of PFBC technology. Further technology development in the US is planned with the deployment of the technology at the MacIntosh Clean Coal project in Lakeland, Florida. Development of uses for solid wastes from PFBC coal-fired power systems is being actively pursued as part of the demonstration of PFBC technologies. Ashes collected from Foster Wheeler Energia Oy pilot circulating PFBC tests in Karhula, Finland, operating on (1) low sulfur subbituminous and (2) high sulfur bituminous coal; and ash from the AEP`s high-sulfur bituminous coal-fired bubbling PFBC in Brilliant, Ohio, were evaluated in laboratory and pilot-scale ash use testing at Western Research Institute (WRI).

  16. JV Task 120 - Coal Ash Resources Research Consortium Research

    SciTech Connect (OSTI)

    Debra Pflughoeft-Hassett; Loreal Heebink; David Hassett; Bruce Dockter; Kurt Eylands; Tera Buckley; Erick Zacher

    2009-03-28

    projects provide an opportunity for non-CARRC members to sponsor specific research or technology transfer consistent with CARRC goals. This report covers CARRC activities from January 2007 through March 2009. These activities have been reported in CARRC Annual Reports and in member meetings over the past 2 years. CARRC continues to work with industry and various government agencies with its research, development, demonstration, and promotional activities nearing completion at the time of submission of this report. CARRC expects to continue its service to the coal ash industry in 2009 and beyond to work toward the common goal of advancing coal ash utilization by solving CCP-related technical issues and promoting the environmentally safe, technically sound, and economically viable management of these complex and changing materials.

  17. Vitrification of simulated radioactive Rocky Flats plutonium containing ash residue with a Stir Melter System

    SciTech Connect (OSTI)

    Marra, J.C.; Kormanyos, K.R.; Overcamp, T.J.

    1996-10-01

    A demonstration trial has been completed in which a simulated Rocky Flats ash consisting of an industrial fly-ash material doped with cerium oxide was vitrified in an alloy tank Stir-Melter{trademark} System. The cerium oxide served as a substitute for plutonium oxide present in the actual Rocky Flats residue stream. The glass developed falls within the SiO{sub 2} + Al{sub 2}O{sub 3}/{Sigma}Alkali/B{sub 2}O{sub 3} system. The glass batch contained approximately 40 wt% of ash, the ash was modified to contain {approximately} 5 wt% CeO{sub 2} to simulate plutonium chemistry in the glass. The ash simulant was mixed with water and fed to the Stir-Melter as a slurry with a 60 wt% water to 40 wt% solids ratio. Glass melting temperature was maintained at approximately 1,050 C during the melting trials. Melting rates as functions of impeller speed and slurry feed rate were determined. An optimal melting rate was established through a series of evolutionary variations of the control variables` settings. The optimal melting rate condition was used for a continuous six hour steady state run of the vitrification system. Glass mass flow rates of the melter were measured and correlated with the slurry feed mass flow. Melter off-gas was sampled for particulate and volatile species over a period of four hours during the steady state run. Glass composition and durability studies were run on samples collected during the steady state run.

  18. Development of Artificial Ash Accelerated Accumulation Test | Department of

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

    Energy Artificial Ash Accelerated Accumulation Test Development of Artificial Ash Accelerated Accumulation Test Poster presented at the 16th Directions in Engine-Efficiency and Emissions Research (DEER) Conference in Detroit, MI, September 27-30, 2010. p-04_fujii.pdf (138.91 KB) More Documents & Publications Impact of Honeycomb Ceramics Geometrical Cell Design on Urea SCR System Controlled Experiments on the Effects of Lubricant/Additive (Low-Ash, Ashless) Characteristics on DPF

  19. Lubricant Formulation and Consumption Effects on Diesel Exhaust Ash

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

    Emissions: | Department of Energy Lubricant Formulation and Consumption Effects on Diesel Exhaust Ash Emissions: Lubricant Formulation and Consumption Effects on Diesel Exhaust Ash Emissions: 2005 Diesel Engine Emissions Reduction (DEER) Conference Presentations and Posters 2005_deer_plumley.pdf (398.5 KB) More Documents & Publications Detailed Characterization of Lubricant-Derived Ash-Related Species in Diesel Exhaust and Aftertreatment Systems Unraveling DPF Degradation using Chemical

  20. Recovery of aluminum and other metal values from fly ash

    DOE Patents [OSTI]

    McDowell, William J.; Seeley, Forest G.

    1981-01-01

    The invention described herein relates to a method for improving the acid leachability of aluminum and other metal values found in fly ash which comprises sintering the fly ash, prior to acid leaching, with a calcium sulfate-containing composition at a temperature at which the calcium sulfate is retained in said composition during sintering and for a time sufficient to quantitatively convert the aluminum in said fly ash into an acid-leachable form.

  1. Recovery of aluminum and other metal values from fly ash

    DOE Patents [OSTI]

    McDowell, W.J.; Seeley, F.G.

    1979-11-01

    The invention relates to a method for improving the acid leachability of aluminum and other metal values found in fly ash which comprises sintering the fly ash, prior to acid leaching, with a calcium sulfate-containing composition at a temperature at which the calcium sulfate is retained in said composition during sintering and for a time sufficient to quantitatively convert the aluminum in said fly ash into an acid-leachable form.

  2. Utilization of ash from municipal solid waste combustion

    SciTech Connect (OSTI)

    Jones, C.; Hahn, J.; Magee, B.; Yuen, N.; Sandefur, K.; Tom, J.; Yap, C.

    1999-09-01

    This ash study investigated the beneficial use of municipal waste combustion combined ash from the H-POWER facility in Oahu. These uses were grouped into intermediate cover for final closure of the Waipahu landfill, daily cover at the Waimanalo Gulch Landfill, and partial replacement for aggregate in asphalt for road paving. All proposed uses examine combined fly and bottom ash from a modern waste-to-energy facility that meets requirements of the Clean Air Act Amendments for Maximum Achievable Control Technology.

  3. High Carbon Fly Ash Treatment | netl.doe.gov

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

    High Carbon Fly Ash Treatment NETL Collaborators Invent Method for Treating High Carbon Fly Ash The U.S. Patent and Trademark Office has assigned Patent No. 8,440,015 to researchers from Waynesburg University and the National Energy Technology Laboratory (NETL) for a thermal method that retains yet passivates carbon and/or other components in fly ash. John Baltrus, a research chemist at NETL, along with Professor Robert LaCount and Douglas Kern of Waynesburg University cooperated on the

  4. Development of an Accelerated Ash-Loading Protocol for Diesel...

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

    Development of an Accelerated Ash-Loading Protocol for Diesel Particulate Filters Poster presentation at the 2007 Diesel Engine-Efficiency & Emissions Research Conference (DEER ...

  5. Ashe County, North Carolina: Energy Resources | Open Energy Informatio...

    Open Energy Info (EERE)

    Ashe County, North Carolina: Energy Resources Jump to: navigation, search Equivalent URI DBpedia Coordinates 36.4339674, -81.4718387 Show Map Loading map......

  6. Ash Fork, Arizona: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Ash Fork, Arizona: Energy Resources Jump to: navigation, search Equivalent URI DBpedia Coordinates 35.2250114, -112.4840675 Show Map Loading map... "minzoom":false,"mappingser...

  7. Reducing Lubricant Ash Impact on Exhaust Aftertreatment with...

    Office of Environmental Management (EM)

    Reducing Lubricant Ash Impact on Exhaust Aftertreatment with a Oil Conditioning Filter Under the test conditions used in this study, the strong base filter had a significant and ...

  8. Retention of elemental mercury in fly ashes in different atmospheres

    SciTech Connect (OSTI)

    M.A. Lopez-Anton; M. Diaz-Somoano; M.R. Martinez-Tarazona

    2007-01-15

    Mercury is an extremely volatile element, which is emitted from coal combustion to the environment mostly in the vapor phase. To avoid the environmental problems that the toxic species of this element may cause, control technologies for the removal of mercury are necessary. Recent research has shown that certain fly ash materials have an affinity for mercury. Moreover, it has been observed that fly ashes may catalyze the oxidation of elemental mercury and facilitate its capture. However, the exact nature of Hg-fly ash interactions is still unknown, and mercury oxidation through fly ash needs to be investigated more thoroughly. In this work, the influence of a gas atmosphere on the retention of elemental mercury on fly ashes of different characteristics was evaluated. The retention capacity was estimated comparatively in inert and two gas atmospheres containing species present in coal gasification and coal combustion. Fly ashes produced in two pulverized coal combustion (PCC) plants, produced from coals of different rank (CTA and CTSR), and a fly ash (CTP) produced in a fluidized bed combustion (FBC) plant were used as raw materials. The mercury retention capacity of these fly ashes was compared to the retention obtained in different activated carbons. Although the capture of mercury is very similar in the gasification atmosphere and N{sub 2}, it is much more efficient in a coal combustion retention, being greater in fly ashes from PCC than those from FBC plants. 22 refs., 6 figs., 3 tabs.

  9. Data Summary Report for Hanford Site Coal Ash Characterization

    SciTech Connect (OSTI)

    Sulloway, H. M.

    2012-03-06

    The purpose of this report is to present data and findings from sampling and analysis of five distinct areas of coal ash within the Hanford Site River Corridor

  10. Minimizing Lubricant-Ash Requirement and Impact on Emission Aftertreat...

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

    Reducing Lubricant Ash Impact on Exhaust Aftertreatment with a Oil Conditioning Filter Effects of Fuel Dilution with Biodiesel on Lubricant Acidity, Oxidation and Corrosion ...

  11. Using fly ash and natural pozzolans in long life structures

    SciTech Connect (OSTI)

    Ramme, B.; Jacobsmeyer, J.

    2008-07-01

    The use of fly ash and natural pozzolans in various structures (roads, temples, bridges, buildings etc.) in the USA and Canada is discussed. 22 refs., 4 photos.

  12. Use of co-combustion bottom ash to design an acoustic absorbing material for highway noise barriers

    SciTech Connect (OSTI)

    Arenas, Celia; Leiva, Carlos; Vilches, Luis F.

    2013-11-15

    Highlights: • The particle size of bottom ash influenced the acoustic behavior of the barrier. • The best sound absorption coefficients were measured for larger particle sizes. • The maximum noise absorption is displaced to lower frequencies for higher thickness. • A noise barrier was designed with better properties than commercial products. • Recycling products from bottom ash no present leaching and radioactivity problems. - Abstract: The present study aims to determine and evaluate the applicability of a new product consisting of coal bottom ash mixed with Portland cement in the application of highway noise barriers. In order to effectively recycle the bottom ash, the influence of the grain particle size of bottom ash, the thickness of the panel and the combination of different layers with various particle sizes have been studied, as well as some environmental properties including leachability (EN-12457-4, NEN-7345) and radioactivity tests. Based on the obtained results, the acoustic properties of the final composite material were similar or even better than those found in porous concrete used for the same application. According to this study, the material produced presented no environmental risk.

  13. Effect of inactive impurities on the burning of ICF targets

    SciTech Connect (OSTI)

    Gus'kov, S. Yu.; Il'in, D. V.; Sherman, V. E.

    2011-12-15

    The efficiency of thermonuclear burning of the spherical deuterium-tritium (DT) plasma of inertial confinement fusion (ICF) targets in the presence of low-Z impurities (such as lithium, carbon, or beryllium) with arbitrary concentrations is investigated. The effect of impurities produced due to the mixing of the thermonuclear fuel with the material of the structural elements of the target during its compression on the process of target burning is studied, and the possibility of using solid noncryogenic thermonuclear fuels in ICF targets is analyzed. Analytical dependences of the ignition energy and target thermonuclear gain on the impurity concentration are obtained. The models are constructed for homogeneous and inhomogeneous plasmas for the case in which the burning is initiated in the central heated region of the target and then propagates into the surrounding relatively cold fuel. Two possible configurations of an inhomogeneous plasma, namely, an isobaric configuration formed in the case of spark ignition of the target and an isochoric configuration formed in the case of fast ignition, are considered. The results of numerical simulations of the burning of the DT plasma of ICF targets in a wide range of impurity concentrations are presented. The simulations were performed using the TEPA one-dimensional code, in which the thermonuclear burning kinetics is calculated by the Monte Carlo method. It is shown that the strongest negative effect related to the presence of impurities is an increase in the energy of target ignition. It is substantiated that the most promising solid noncryogenic fuel is DT hydride of beryllium (BeDT). The requirements to the plasma parameters at which BeDT can be used as a fuel in noncryogenic ICF targets are determined. Variants of using noncryogenic targets with a solid thermonuclear fuel are proposed.

  14. Comment on "Kinetic theory for a mobile impurity in a degenerate...

    Office of Scientific and Technical Information (OSTI)

    Comment on "Kinetic theory for a mobile impurity in a degenerate Tonks-Girardeau gas" Citation Details In-Document Search Title: Comment on "Kinetic theory for a mobile impurity in ...

  15. Comment on "Kinetic theory for a mobile impurity in a degenerate...

    Office of Scientific and Technical Information (OSTI)

    Comment on "Kinetic theory for a mobile impurity in a degenerate Tonks-Girardeau gas" Title: Comment on "Kinetic theory for a mobile impurity in a degenerate Tonks-Girardeau gas" ...

  16. Effect of nonmagnetic impurities on the residual electron-spin-resonance linewidth of Er:Ag dilute alloys

    SciTech Connect (OSTI)

    Dahlberg, E.D.; Souletie, J.; Dodds, S.A.; Chock, E.P.; Orbach, R.L. )

    1990-06-01

    We have undertaken a systematic investigation of the effect of nonmagnetic impurities on the residual ({ital T}{r arrow}0 K) electron-spin-resonance linewidth of erbium in dilute (200 parts per million atomic (ppm)) Er:Ag alloys. The nonmagnetic impurities used were In, Sn, Sb, Y, and Lu in the concentration range of 500--4600 ppm. The linewidth broadening caused by these impurities was found to be 0.2{plus minus}0.11, 0.49{plus minus}0.1, 0.51{plus minus}0.11, 1.4{plus minus}0.18, and 1.37{plus minus}0.32 G/1000 ppm atomic frequency (GHz) for In, Sn, Sb, Y, and Lu, respectively. The most reasonable source of the Er line broadening is the mixing of the crystal-field levels of the Er by the Kohn-Vosko oscillations in the charge density. The broadening of the Er resonance line due to In, Sn, and Sb doping is consistent with the expected form of the oscillations. Also, Y and Lu are equivalent in the broadening of the Er line, as expected. However, the scaling of the Y and Lu broadening compared to that due to the In, Sn, and Sb is not consistent. The reasons for this are not understood.

  17. Research in Hydrogen Passivation of Defects and Impurities in Silicon: Final Subcontract Report, 2 May 2000--2 July 2003

    SciTech Connect (OSTI)

    Ashok, S.

    2004-05-01

    Our work consists of hydrogenating silicon (Si) samples by different methods such as low-energy implantation, electron cyclotron resonance (ECR) plasma, and thermal diffusion. The samples will be provided through NREL. The experimental work carried out at Penn State involves the study of hydrogen interaction with defects, trapping, migration, and formation of complexes. The principal vehicle for the latter study will be ion implantation, and the intent is to understand mechanisms of defect passivation and activation by hydrogen. The theoretical studies will consist of the calculation of the structure and parameters related to hydrogen diffusion and interactions of hydrogen with transition metal impurities in silicon. Experimental studies will involve measurements of hydrogen and hydrogen-impurity complexes, and diffusion properties of various species of hydrogen in Si. The experimental work at Penn State includes introduction of hydrogen in a variety of photovoltaic Si by ECR plasma, low-energy ion implantation, and thermal diffusion. The specific tasks will be the evaluation of hydrogen interaction with defects engineered by ion implantation; defect passivation, activation, and migration in hydrogenated Si under thermal anneal; and electrical activity of hydrogen-impurity complexes. Electrical characterization will entail I-V and C-V measurements, spreading resistance, and deep-level transient spectroscopy.

  18. Predicting and validating the tracking of a Volcanic Ash Cloud during the 2006 Eruption of Mt. Augustine Volcano

    SciTech Connect (OSTI)

    Webley, Peter W.; Atkinson, D.; Collins, Richard L.; Dean, K.; Fochesatto, J.; Sassen, Kenneth; Cahill, Catherine F.; Prata, A.; Flynn, Connor J.; Mizutani, K.

    2008-11-01

    On 11 January 2006, Mount Augustine volcano in southern Alaska began erupting after 20-year repose. The Anchorage Forecast Office of the National Weather Service (NWS) issued an advisory on 28 January for Kodiak City. On 31 January, Alaska Airlines cancelled all flights to and from Anchorage after multiple advisories from the NWS for Anchorage and the surrounding region. The Alaska Volcano Observatory (AVO) had reported the onset of the continuous eruption. AVO monitors the approximately 100 active volcanoes in the Northern Pacific. Ash clouds from these volcanoes can cause serious damage to an aircraft and pose a serious threat to the local communities, and to transcontinental air traffic throughout the Arctic and sub-Arctic region. Within AVO, a dispersion model has been developed to track the dispersion of volcanic ash clouds. The model, Puff, was used operational by AVO during the Augustine eruptive period. Here, we examine the dispersion of a volcanic ash cloud from Mount Augustine across Alaska from 29 January through the 2 February 2006. We present the synoptic meteorology, the Puff predictions, and measurements from aerosol samplers, laser radar (or lidar) systems, and satellites. UAF aerosol samplers revealed the presence of volcanic aerosols at the surface at sites where Puff predicted the ash clouds movement. Remote sensing satellite data showed the development of the ash cloud in close proximity to the volcano and a sulfur-dioxide cloud further from the volcano consistent with the Puff predictions. Lidars showed the presence of volcanic aerosol with consistent characteristics aloft over Alaska and were capable of detecting the aerosol, even in the presence of scattered clouds and where the cloud is too thin/disperse to be detected by remote sensing satellite data. The lidar measurements revealed the different trajectories of ash consistent with the Puff predictions. Dispersion models provide a forecast of volcanic ash cloud movement that might be

  19. Chemical leaching of coal to remove ash, alkali and vanadium

    SciTech Connect (OSTI)

    Smit, F.J.; Huggins, D.K.; Berggren, M.; Anast, K.R.

    1986-04-15

    A process is described for upgrading powdered coal to improve the usefulness thereof as a fuel for internal combustion engines which consists of: (a) pressure-leaching powdered coal having a particle size ranging from about 28 mesh to about 200 mesh in an aqueous caustic solution at a temperature ranging from about 175/sup 0/C, to about 350/sup 0/C., the amount of caustic in the solution ranging from about 5% to about 30% by weight, the amount of coal being sufficient to form a slurry comprising about 10% to 30% by weight of solids, (b) hydrochloric acid leaching the caustic leached coal to dissolve acid-soluble constituents resulting from the caustic leach, (c) pressure leaching the acid-leached coal with a liquid from the group consisting of water and dilute aqueous ammonia to remove sodium and chlorine, and thereafter (d) filtering and washing the pressure leached coal, whereby the coal is characterized by up to about 0.85% by weight of ash, up to about 150 ppm of alkali metals and up to about 4 ppm vanadium.

  20. Ab initio study of semiconductor atoms impurities in zigzag edge (10,0) carbon nanotubes

    SciTech Connect (OSTI)

    Muttaqien, Fahdzi Suprijadi

    2015-04-16

    The substitutional impurities in zigzag edge (10,0) carbon nanotubes have been studied by using first principles calculations. Silicon (Si), gallium (Ga), and arsenic (As) atom have been chosen as semiconductor based-atom for replacing carbon atoms in CNTs surface. The silicon atom changes the energy gap of pristine zigzag (10,0) CNT, it is 0.19 eV more narrow than that of pristine CNT. Geometrically, the silicon atom creates sp{sup 3} bond with three adjacent carbon atoms, where the tetrahedral form of its sp{sup 3} bond is consisted of free unoccupied state. The silicon atom does not induce magnetism to zigzag CNT. Due to gallium (Ga) and arsenic (As) atom substitution, the zigzag CNT becomes metallic and has magnetic moment of 1?{sub B}. The valance and conduction band are crossed each other, then the energy gap is vanished. The electronic properties of GaAs-doped CNT are dominantly affected by gallium atom and its magnetic properties are dominantly affected by arsenic atom. These results prove that the CNT with desired properties can be obtained with substitutional impurities without any giving structural defect.

  1. Effects of chemical composition of fly ash on efficiency of metal separation in ash-melting of municipal solid waste

    SciTech Connect (OSTI)

    Okada, Takashi; Tomikawa, Hiroki

    2013-03-15

    Highlights: ► Separation of Pb and Zn from Fe and Cu in ash-melting of municipal solid waste. ► Molar ratio of Cl to Na and K in fly ash affected the metal-separation efficiency. ► The low molar ratio and a non-oxidative atmosphere were better for the separation. - Abstract: In the process of metal separation by ash-melting, Fe and Cu in the incineration residue remain in the melting furnace as molten metal, whereas Pb and Zn in the residue are volatilized. This study investigated the effects of the chemical composition of incineration fly ash on the metal-separation efficiency of the ash-melting process. Incineration fly ash with different chemical compositions was melted with bottom ash in a lab-scale reactor, and the efficiency with which Pb and Zn were volatilized preventing the volatilization of Fe and Cu was evaluated. In addition, the behavior of these metals was simulated by thermodynamic equilibrium calculations. Depending on the exhaust gas treatment system used in the incinerator, the relationships among Na, K, and Cl concentrations in the incineration fly ash differed, which affected the efficiency of the metal separation. The amounts of Fe and Cu volatilized decreased by the decrease in the molar ratio of Cl to Na and K in the ash, promoting metal separation. The thermodynamic simulation predicted that the chlorination volatilization of Fe and Cu was prevented by the decrease in the molar ratio, as mentioned before. By melting incineration fly ash with the low molar ratio in a non-oxidative atmosphere, most of the Pb and Zn in the ash were volatilized leaving behind Fe and Cu.

  2. The recycling of the coal fly ash in glass production

    SciTech Connect (OSTI)

    Erol, M.M.; Kucukbayrak, S.; Ersoy-Mericboyu, A.

    2006-09-15

    The recycling of fly ash obtained from the combustion of coal in thermal power plant has been studied. Coal fly ash was vitrified by melting at 1773 K for 5 hours without any additives. The properties of glasses produced from coal fly ash were investigated by means of Differential Thermal Analysis (DTA), X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) techniques. DTA study indicated that there was only one endothermic peak at 1003 K corresponding to the glass transition temperature. XRD analysis showed the amorphous state of the glass sample produced from coal fly ash. SEM investigations revealed that the coal fly ash based glass sample had smooth surface. The mechanical, physical and chemical properties of the glass sample were also determined. Recycling of coal fly ash by using vitrification technique resulted to a glass material that had good mechanical, physical and chemical properties. Toxicity characteristic leaching procedure (TCLP) results showed that the heavy metals of Pb, Cr, Zn and Mn were successfully immobilized into the glass. It can be said that glass sample obtained by the recycling of coal fly ash can be taken as a non-hazardous material. Overall, results indicated that the vitrification technique is an effective way for the stabilization and recycling of coal fly ash.

  3. Optimizing the use of fly ash in concrete

    SciTech Connect (OSTI)

    Thomas, M.

    2007-07-01

    The optimum amount of fly ash varies not only with the application, but also with composition and proportions of all the materials in the concrete mixture (especially the fly ash), the conditions during placing (especially temperature), construction practices (for example, finishing and curing) and the exposure conditions. This document discusses issues related to using low to very high levels of fly ash in concrete and provides guidance for the use of fly ash without compromising the construction process or the quality of the finished product. The nature of fly ashes including their physical, mineralogical and chemical properties is covered in detail, as well as fly ash variability due to coal composition and plant operating conditions. A discussion on the effects of fly ash characteristics on fresh and hardened concrete properties includes; workability, bleeding, air entrainment, setting time, heat of hydration, compressive strength development, creep, drying shrinkage, abrasion resistance, permeability, resistance to chlorides, alkali-silica reaction (ASR), sulfate resistance, carbonation, and resistance to freezing and thawing and deicer salt scaling. Case studies were selected as examples of some of the more demanding applications of fly ash concrete for ASR mitigation, chloride resistance, and green building.

  4. Process for the recovery of alumina from fly ash

    DOE Patents [OSTI]

    Murtha, M.J.

    1983-08-09

    An improvement in the lime-sinter process for recovering alumina from pulverized coal fly ash is disclosed. The addition of from 2 to 10 weight percent carbon and sulfur to the fly ash-calcium carbonate mixture increase alumina recovery at lower sintering temperatures.

  5. Fly ash and coal mineral matter surface transformations during heating

    SciTech Connect (OSTI)

    Baer, D R; Smith, R D

    1982-05-01

    A study is reported of surface segregation phenomena for fly ash and aluminosilicates representative of coal mineral matter during heating. The materials studied included a 20-..mu..m average diameter fly ash powder, a glass prepared from the fly ash, and Ca- and K-rich aluminosilicate minerals. The samples were heated both in air and under vacuum for extended periods at temperatures up to 1100/sup 0/C. XPS, Auger and SIMS methods were used to obtain relative surface elemental concentrations for major and minor components and depth profiles for some of the samples. Major differences were noted between samples heated in air (oxidizing) and those heated in vacuum (reducing) environments. For the fly ash glass heated in air Fe, Ti and Mg become enriched on the surfaces while heating in vacuum leads to Si surface segregation. Different trends upon heating were also observed for the Ca- and K-rich aluminosilicates. The results indicate two levels of surface enrichment upon the fly ash glass; a thin (< 500 A) layer and a thicker (1- to 2-..mu..m) layer most evident for heating in air where an Fe-rich layer is formed. The present results indicate that the rates of surface segregation may not be sufficiently fast on the time scale of fly ash formation to result in equilibrium surface segregation. It is concluded that condensation processes during fly ash formation probably play a major role in the observed fly ash surface enrichments.

  6. Hot-Gas Filter Ash Characterization Project

    SciTech Connect (OSTI)

    Swanson, M.L.; Hurley, J.P.; Dockter, B.A.; O`Keefe, C.A.

    1997-07-01

    Large-scale hot-gas filter testing over the past 10 years has revealed numerous cases of cake buildup on filter elements that has been difficult, if not impossible, to remove. At times, the cake can blind or bridge between candle filters, leading to filter failure. Physical factors, including particle-size distribution, particle shape, the aerodynamics of deposition, and system temperature, contribute to the difficulty in removing the cake, but chemical factors such as surface composition and gas-solid reactions also play roles in helping to bond the ash to the filters or to itself. This project is designed to perform the research necessary to determine the fuel-, sorbent-, and operations-related conditions that lead to blinding or bridging of hot-gas particle filters. The objectives of the project are threefold: (1) Determine the mechanisms by which a difficult-to-clean ash is formed and how it bridges hot-gas filters (2) Develop a method to determine the rate of bridging based on analyses of the feed coal and sorbent, filter properties, and system operating conditions and (3) Suggest and test ways to prevent filter bridging.

  7. STRATEGIES AND TECHNOLOGY FOR MANAGING HIGH-CARBON ASH

    SciTech Connect (OSTI)

    Robert Hurt; Eric Suuberg; John Veranth; Xu Chen

    2002-09-10

    The overall objective of the present project is to identify and assess strategies and solutions for the management of industry problems related to carbon in ash. Specific research issues to be addressed include: (1) the effect of parent fuel selection on ash properties and adsorptivity, including a first ever examination of the air entrainment behavior of ashes from alternative (non-coal) fuels; (2) the effect of various low-NOx firing modes on ash properties and adsorptivity; and (3) the kinetics and mechanism of ash ozonation. This data will provide scientific and engineering support of the ongoing process development activities. During this fourth project period we completed the characterization of ozone-treated carbon surfaces and wrote a comprehensive report on the mechanism through which ozone suppresses the adsorption of concrete surfactants.

  8. Anisotropic charged impurity-limited carrier mobility in monolayer phosphorene

    SciTech Connect (OSTI)

    Ong, Zhun-Yong; Zhang, Gang; Zhang, Yong Wei

    2014-12-07

    The room temperature carrier mobility in atomically thin 2D materials is usually far below the intrinsic limit imposed by phonon scattering as a result of scattering by remote charged impurities in its environment. We simulate the charged impurity-limited carrier mobility μ in bare and encapsulated monolayer phosphorene. We find a significant temperature dependence in the carrier mobilities (μ ∝ T{sup −γ}) that results from the temperature variability of the charge screening and varies with the crystal orientation. The anisotropy in the effective mass leads to an anisotropic carrier mobility, with the mobility in the armchair direction about one order of magnitude larger than in the zigzag direction. In particular, this mobility anisotropy is enhanced at low temperatures and high carrier densities. Under encapsulation with a high-κ overlayer, the mobility increases by up to an order of magnitude although its temperature dependence and its anisotropy are reduced.

  9. A REVIEW OF RECENT IMPURITY MEASUREMENTS OF LANL MATERIAL

    SciTech Connect (OSTI)

    Edwards, T.

    2012-07-12

    The Applied Computational Engineering and Statistics (ACES) group of the Savannah River National Laboratory (SRNL) was asked to review recent measurements performed by the Los Alamos National Laboratory (LANL) on material from that facility that is being considered for processing through the Mixed Oxide (MOX) Fuel Fabrication Facility (MFFF) at the Savannah River Site (SRS). There are specification limits for impurities in the feed to the MOX facility: a maximum limit and an exceptional limit. The limits for an impurity apply to the population of concentration values for that impurity for a class of material that is to be processed through MOX. For the purposes of this report, these limits were defined as follows. The concentration of an elemental impurity, expressed as micrograms of the element per gram of plutonium ({micro}g/g Pu), is to be no more than the maximum limit for that element for 98% of the material coming through MOX; that is, 98% of the material processed at MOX is to have a concentration of the given element less than the maximum limit. In addition, the concentration for a given element is to be no more than the exceptional limit for that element for 99.9% of the material processed through MOX. The measurements evaluated as part of this study included LANL blend lots 1 through 29 and cover carbon (C), chlorine (Cl), fluorine (F), nitrogen (N), phosphorous (P), and sulfur (S). Note that all of the measurements for each impurity were below their respective maximum (and obviously, therefore, their exceptional) limits. Thus, there is no immediate concern regarding the LANL material being suitable for processing through MOX. Two approaches were used to investigate the quantiles of the impurity populations. The first approach used was a nonparametric approach. While the results from this approach did not indicate any problems for any of the impurities, there was too little data available to lead to confident statements about satisfying the maximum and

  10. Quantum critical points of an anisotropic multichannel Kondo impurity

    SciTech Connect (OSTI)

    Schlottmann, P.

    2001-06-01

    The low-temperature behavior of a magnetic impurity of spin S interacting with an electron gas via an anisotropic spin exchange is studied via Bethe{close_quote}s ansatz. The multichannel Kondo model with U(1) invariance is integrable as a function of two continuous (the exchange and the anisotropy) and two discrete parameters, namely the impurity spin S and the number of channels n. As a function of S and n we distinguish: (i) the compensated case with n=2S, (ii) the overcompensated case if n{gt}2S, and (iii) the undercompensated case (n{lt}2S). While in case (i) the ground state is a singlet, the cases (ii), and (iii) yield quantum critical points. The undercompensated one is of a new type with the critical exponents depending on the anisotropy. {copyright} 2001 American Institute of Physics.

  11. COAL-FIRED UTILITY BOILERS: SOLVING ASH DEPOSITION PROBLEMS

    SciTech Connect (OSTI)

    Christopher J. Zygarlicke; Donald P. McCollor; Steven A. Benson; Jay R. Gunderson

    2001-04-01

    The accumulation of slagging and fouling ash deposits in utility boilers has been a source of aggravation for coal-fired boiler operators for over a century. Many new developments in analytical, modeling, and combustion testing methods in the past 20 years have made it possible to identify root causes of ash deposition. A concise and comprehensive guidelines document has been assembled for solving ash deposition as related to coal-fired utility boilers. While this report accurately captures the current state of knowledge in ash deposition, note that substantial research and development is under way to more completely understand and mitigate slagging and fouling. Thus, while comprehensive, this document carries the title ''interim,'' with the idea that future work will provide additional insight. Primary target audiences include utility operators and engineers who face plant inefficiencies and significant operational and maintenance costs that are associated with ash deposition problems. Pulverized and cyclone-fired coal boilers are addressed specifically, although many of the diagnostics and solutions apply to other boiler types. Logic diagrams, ash deposit types, and boiler symptoms of ash deposition are used to aid the user in identifying an ash deposition problem, diagnosing and verifying root causes, determining remedial measures to alleviate or eliminate the problem, and then monitoring the situation to verify that the problem has been solved. In addition to a step-by-step method for identifying and remediating ash deposition problems, this guideline document (Appendix A) provides descriptions of analytical techniques for diagnostic testing and gives extensive fundamental and practical literature references and addresses of organizations that can provide help in alleviating ash deposition problems.

  12. Assessment of the impact of radionuclides in coal ash

    SciTech Connect (OSTI)

    Styron, C.E.; Bishop, C.T.; Casella, V.R.; Jenkins, P.H.; Yanko, W.H.

    1981-01-01

    An assessment of the potential environmental and health impacts of radionuclides in the coal fuel cycle is being conducted at Mound. This paper describes our studies evaluating the potential for migration of radionuclides from ash disposal sites. Studies at a power plant burning western US coal dealt with an assessment of potential radiation doses from coal ash ponds and leachate discharges of radionuclides from the ponds. Emanation of radon-222 from the ash is relatively low. The emanation of radon-222 from the ash pond (radium-226 at 4.5 pCi/g) is predicted to be about six times less than from soil (radium-226 at 1 pCi/g). Ash with radium-226 at 25 pCi/g would approximate emanation of radon-222 from soil. At 1000 m from the center of the ash pond area, radon-222 from the ash pond is predicted to be 1000 to 6000 times less than background (0.1 to 0.5 pCi/liter). Pathways exist for transport of radionuclides leached from ash into the aquifer beneath the holding ponds, but concentrations of radionuclides in water leaving the pond are lower than concentrations in groundwater which is upgradient of the ponds. Leachability of the ash is quite low, on the order of 0.002% in one month, and flow of ash sluicing water (3% of the volume of the ponds each day) has actually diluted normal background concentrations of radionuclides in the aquifer between the ponds and the adjacent river.

  13. Toxicity mitigation and solidification of municipal solid waste incinerator fly ash using alkaline activated coal ash

    SciTech Connect (OSTI)

    Ivan Diaz-Loya, E.; Allouche, Erez N.; Eklund, Sven; Joshi, Anupam R.; Kupwade-Patil, Kunal

    2012-08-15

    Highlights: Black-Right-Pointing-Pointer Incinerator fly ash (IFA) is added to an alkali activated coal fly ash (CFA) matrix. Black-Right-Pointing-Pointer Means of stabilizing the incinerator ash for use in construction applications. Black-Right-Pointing-Pointer Concrete made from IFA, CFA and IFA-CFA mixes was chemically characterized. Black-Right-Pointing-Pointer Environmentally friendly solution to IFA disposal by reducing its toxicity levels. - Abstract: Municipal solid waste (MSW) incineration is a common and effective practice to reduce the volume of solid waste in urban areas. However, the byproduct of this process is a fly ash (IFA), which contains large quantities of toxic contaminants. The purpose of this research study was to analyze the chemical, physical and mechanical behaviors resulting from the gradual introduction of IFA to an alkaline activated coal fly ash (CFA) matrix, as a mean of stabilizing the incinerator ash for use in industrial construction applications, where human exposure potential is limited. IFA and CFA were analyzed via X-ray fluorescence (XRF), X-ray diffraction (XRD) and Inductive coupled plasma (ICP) to obtain a full chemical analysis of the samples, its crystallographic characteristics and a detailed count of the eight heavy metals contemplated in US Title 40 of the Code of Federal Regulations (40 CFR). The particle size distribution of IFA and CFA was also recorded. EPA's Toxicity Characteristic Leaching Procedure (TCLP) was followed to monitor the leachability of the contaminants before and after the activation. Also images obtained via Scanning Electron Microscopy (SEM), before and after the activation, are presented. Concrete made from IFA, CFA and IFA-CFA mixes was subjected to a full mechanical characterization; tests include compressive strength, flexural strength, elastic modulus, Poisson's ratio and setting time. The leachable heavy metal contents (except for Se) were below the maximum allowable limits and in many cases

  14. Fluidization characteristics of power-plant fly ashes and fly ash-charcoal mixtures. [MS Thesis; 40 references

    SciTech Connect (OSTI)

    Nguyen, C.T.

    1980-03-01

    As a part of the continuing research on aluminum recovery from fly ash by HiChlor process, a plexiglass fluidization column system was constructed for measurement of fluidization parameters for power-plant fly ashes and fly ash-charcoal mixtures. Several bituminous and subbituminous coal fly ashes were tested and large differences in fluidization characteristics were observed. Fly ashes which were mechanically collected fluidized uniformly at low gas flow rates. Most fly ashes which were electrostatically precipitated exhibited channeling tendency and did not fluidize uniformly. Fluidization characteristics of electrostatically collected ashes improve when the finely divided charcoal powder is added to the mixture. The fluidization of the mixture was aided initially by a mechanical stirrer. Once the fluidization had succeeded, the beds were ready to fluidize without the assistance of a mechanical action. Smooth fluidization and large bed expansion were usually observed. The effects of charcoal size and aspect ratio on fluidization characteristics of the mixtures were also investigated. Fluidization characteristics of a fly ash-coal mixture were tested. The mixture fluidized only after being oven-dried for a few days.

  15. Engineering Metal Impurities in Multicrystalline Silicon Solar Cells

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

    Engineering Metal Impurities in Multicrystalline Silicon Solar Cells Print Transition metals are one of the main culprits in degrading the efficiency of multicrystalline solar cells. With a suite of x-ray microprobe techniques, a multi-institutional collaboration led by researchers from the University of California, Berkeley, and Berkeley Lab studied the distribution of metal clusters in a variety of multicrystalline solar cells before and after processing. Their discovery that the size, spatial

  16. Engineering Metal Impurities in Multicrystalline Silicon Solar Cells

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

    Engineering Metal Impurities in Multicrystalline Silicon Solar Cells Print Transition metals are one of the main culprits in degrading the efficiency of multicrystalline solar cells. With a suite of x-ray microprobe techniques, a multi-institutional collaboration led by researchers from the University of California, Berkeley, and Berkeley Lab studied the distribution of metal clusters in a variety of multicrystalline solar cells before and after processing. Their discovery that the size, spatial

  17. The Role of Impurities in the Complex Hydrides

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

    Impurities in the Complex Hydrides Eric H. Majzoub Center for Nanoscience Department of Physics University of Missouri - St. Louis Acknowledgements UMSL Xianfeng Liu, David Peaslee, Tim Mason, Dongxue Zhao, Gang Wang, Chris Carr, Waruni Jayawardana, Alyssa McFarlane, Henry Hamper, Hua Ning SNL Vitalie Stavila, Mark Allendorf, Lennie Klebanoff * Department of Energy EERE * Boeing * NASA Space grant Consortium 2 Objectives and Overview I. Fundamental Limitations - density of hydrogen and

  18. METHOD FOR REDUCING THE IMPURITY RESISTIVITY OF SODIUM

    DOE Patents [OSTI]

    Post, R.F.; Taylor, C.E.

    1963-08-13

    The inherent resistivity of sodium, at cryogenic temperatures, can be reduced by clustering the impurity atoms within the crystal latiice structure of the sodium, thereby reducing the effective electron collision cross section and thus reducing the number of collisions between the electrons and such lattice imperfections. The clustering is effected by heating the sodium to a temperature approaching its melting point, and maintaining the temperature for a period of time ranging generally from two to six days. (AEC)

  19. Engineering Metal Impurities in Multicrystalline Silicon Solar Cells

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

    Engineering Metal Impurities in Multicrystalline Silicon Solar Cells Print Transition metals are one of the main culprits in degrading the efficiency of multicrystalline solar cells. With a suite of x-ray microprobe techniques, a multi-institutional collaboration led by researchers from the University of California, Berkeley, and Berkeley Lab studied the distribution of metal clusters in a variety of multicrystalline solar cells before and after processing. Their discovery that the size, spatial

  20. Engineering Metal Impurities in Multicrystalline Silicon Solar Cells

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

    Engineering Metal Impurities in Multicrystalline Silicon Solar Cells Print Transition metals are one of the main culprits in degrading the efficiency of multicrystalline solar cells. With a suite of x-ray microprobe techniques, a multi-institutional collaboration led by researchers from the University of California, Berkeley, and Berkeley Lab studied the distribution of metal clusters in a variety of multicrystalline solar cells before and after processing. Their discovery that the size, spatial

  1. Engineering Metal Impurities in Multicrystalline Silicon Solar Cells

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

    Engineering Metal Impurities in Multicrystalline Silicon Solar Cells Print Transition metals are one of the main culprits in degrading the efficiency of multicrystalline solar cells. With a suite of x-ray microprobe techniques, a multi-institutional collaboration led by researchers from the University of California, Berkeley, and Berkeley Lab studied the distribution of metal clusters in a variety of multicrystalline solar cells before and after processing. Their discovery that the size, spatial

  2. Engineering Metal Impurities in Multicrystalline Silicon Solar Cells

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

    Engineering Metal Impurities in Multicrystalline Silicon Solar Cells Print Transition metals are one of the main culprits in degrading the efficiency of multicrystalline solar cells. With a suite of x-ray microprobe techniques, a multi-institutional collaboration led by researchers from the University of California, Berkeley, and Berkeley Lab studied the distribution of metal clusters in a variety of multicrystalline solar cells before and after processing. Their discovery that the size, spatial

  3. Sulfur-impurity Induced Amorphization of Nickel | Argonne Leadership

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

    Computing Facility Sulfur-impurity Induced Amorphization of Nickel Authors: Yuan, Z., Chen, H.P, Wang, W., Nomura, K., Kalia, R.K., Nakano, A., Vashishta, P. Recent experimental and theoretical studies have shown an essential role of sulfur segregation-induced amorphization of crystalline nickel leading to its embrittlement at a critical sulfur concentration of ∼14%, but the atomistic mechanism of the amorphization remains unexplained. Here, molecular dynamics simulations reveal that the

  4. Scandium resonant impurity level in PbTe

    SciTech Connect (OSTI)

    Skipetrov, E. P. Skipetrova, L. A.; Knotko, A. V.; Slynko, E. I.; Slynko, V. E.

    2014-04-07

    We synthesize a scandium-doped PbTe single-crystal ingot and investigate the phase and the elemental composition as well as galvanomagnetic properties of Pb{sub 1-y}Sc{sub y}Te alloys in weak magnetic fields (4.2?K???T???300?K, B???0.07?T) upon varying the scandium content (y???0.02). We find that all investigated samples are single-phase and n-type. The distribution of scandium impurities along the axis of the ingot is estimated to be exponential. An increase of scandium impurity content leads to a monotonous growth of the free electron concentration by four orders of magnitude (approximately from 10{sup 16}?cm{sup ?3} to 10{sup 20}?cm{sup ?3}). In heavily doped alloys (y?>?0.01), the free electron concentration at the liquid-helium temperature tends to saturation, indicating the pinning of the Fermi energy by the scandium resonant impurity level located on the background of the conduction band. Using the two-band Kane and six-band Dimmock dispersion relations for IV-VI semiconductors, dependences of the Fermi energy measured from the bottom of the conduction band E{sub c} on the scandium impurity content are calculated and the energy of the resonant scandium level is estimated to be E{sub Sc}???E{sub c}?+?280?meV. Diagrams of electronic structure rearrangement of Pb{sub 1-y}Sc{sub y}Te alloys upon doping are proposed.

  5. Localized states of a semi-infinite zigzag graphene sheet with impurity lines

    SciTech Connect (OSTI)

    Cunha, A. M. C.; Ahmed, Maher Z.; Cottam, M. G.; Filho, R. N. Costa

    2014-07-07

    The localized states of a semi-infinite zigzag graphene sheet are studied using a tight-binding model that allows for the inclusion of either one or two lines of impurities. These impurity lines of atoms are placed in rows labeled as n (n=1, 2, 3, ), where n=1 is the free edge. The localized defect modes associated with these impurities are studied analytically and numerically within a tridiagonal matrix formalism. For one impurity line, the modes are analyzed according to the position of that line on the sheet, whereas the modes for two impurities are studied also according to their separation and their positions relative to the edge. When an impurity line is located at the edge (n=1), it is found that the edge states are modified. When the impurities are positioned away from an edge (n>1), additional localized modes are found to occur that may be relatively flat in their dispersion.

  6. Multi-fluid code simulations including anomalous non-diffusive transport of plasma and impurities in the tokamak SOL

    SciTech Connect (OSTI)

    Pigarov, A Y; West, W; Soukhanovskii, V; Rognlien, T; Maingi, R; Lipschultz, B; Krasheninnikov, S; LaBombard, B

    2003-11-25

    Fast intermittent transport has been observed in the scrape-off layer (SOL) of major tokamaks including Alcator C-Mod, DIII-D, and NSTX. This kind of transport is not diffusive but rather convective. It strongly increases plasma flux to the chamber walls and enhances the recycling of neutral particles in the main chamber. We discuss anomalous cross-field convection (ACFC) model for impurity and main plasma ions and its relation to intermittent transport events, i.e. plasma density blobs and holes in the SOL. Along with plasma diffusivity coefficients, our transport model introduces time-independent anomalous cross-field convective velocity. In the discharge modelling, diffusivity coefficients and ACFC velocity profiles are adjusted to match a set of representative experimental data. We use this model in the edge plasma physics code UEDGE to simulate the multi-fluid two-dimensional transport for these three tokamaks. We present simulation results suggesting the dominance of anomalous convection in the far SOL transport. These results are consistent with the hypothesis that the chamber wall is an important source of impurities and that different impurity charge states have different directions of anomalous convective velocity.

  7. Theory of the Anderson impurity model: The Schrieffer{endash}Wolff transformation reexamined

    SciTech Connect (OSTI)

    Kehrein, S.K.; Mielke, A.

    1996-11-01

    We test the method of infinitesimal unitary transformations recently introduced by Wegner on the Anderson single impurity model. It is demonstrated that infinitesimal unitary transformations in contrast to the Schrieffer{endash}Wolff transformation allow the construction of an effective Kondo Hamiltonian consistent with the established results in this well understood model. The main reason for this is the intrinsic energy scale separation of Wegner`s approach with respect to arbitrary energy differences coupled by matrix elements. This allows the construction of an effective Hamiltonian without facing a vanishing energy denominator problem. Similar energy denominator problems are troublesome in many models. Infinitesimal unitary transformations have the potential to provide a general framework for the systematic derivation of effective Hamiltonians without such problems. Copyright {copyright} 1996 Academic Press, Inc.

  8. Scattering in graphene associated with charged out-of-plane impurities

    SciTech Connect (OSTI)

    Liu, Yue Goswami, Aditi; Liu, Feilong; Smith, Darryl L.; Ruden, P. Paul

    2014-12-21

    A charged impurity outside the plane of a graphene layer contributes to scattering of electrons (and holes) in the graphene. The interaction occurs through two distinct mechanisms associated with the charge: (1) the (screened) Coulomb potential, and (2) the electric field perpendicular to the graphene plane that causes a spatially varying Rashba spin-orbit interaction. Both types of scattering are examined, with the screened potential self-consistently calculated in nonlinear Thomas-Fermi approximation. Different selection rules for the two mechanisms lead to qualitative differences in the differential scattering cross-sections. Using accepted parameters for the Rashba interaction, the latter is found to make only a very small contribution to the scattering associated with a remote charge.

  9. Mutagenicity and genotoxicity of coal fly ash water leachate

    SciTech Connect (OSTI)

    Chakraborty, R.; Mukherjee, A.

    2009-03-15

    Fly ash is a by-product of coal-fired electricity generation plants. The prevalent practice of disposal is as slurry of ash and water to storage or ash ponds located near power stations. This has lain to waste thousands of hectares of land all over the world. Since leaching is often the cause of off-site contamination and pathway of introduction into the human environment, a study on the genotoxic effects of fly ash leachate is essential. Leachate prepared from the fly ash sample was analyzed for metal content, and tested for mutagenicity and genotoxicity. Analyses of metals show predominance of the metals - sodium, silicon, potassium, calcium, magnesium, iron, manganese, zinc, and sulphate. The Ames Salmonella mutagenicity assay, a short-term bacterial reverse mutation assay, was conducted on two-tester strains of Salmonella typhimurium strains TA97a and TA102. For genotoxicity, the alkaline version of comet assay on fly ash leachate was carried in vitro on human blood cells and in vivo on Nicotiana plants. The leachate was directly mutagenic and induced significantconcentration-dependent increases in DNA damage in whole blood cells, lymphocytes, and in Nicotiana plants. The comet parameters show increases in tail DNA percentage (%), tail length (mu m), and olive tail moment (arbitrary units). Our results indicate that leachate from fly ash dumpsites has the genotoxic potential and may lead to adverse effects on vegetation and on the health of exposed human populations.

  10. Water holding capacities of fly ashes: Effect of size fractionation

    SciTech Connect (OSTI)

    Sarkar, A.; Rano, R.

    2007-07-01

    Water holding capacities of fly ashes from different thermal power plants in Eastern India have been compared. Moreover, the effect of size fractionation (sieving) on the water holding capacities has also been determined. The desorption rate of water held by the fly ash fractions at ambient temperature (25-30{sup o}C) has been investigated. The effect of mixing various size fractions of fly ash in increasing the water holding capacities of fly ash has been studied. It is observed that the fly ash obtained from a thermal power plant working on stoker-fired combustor has the highest water holding capacity, followed by the one that works on pulverized fuel combustor. Fly ash collected from super thermal power plant has the least water holding capacity (40.7%). The coarser size fractions of fly ashes in general have higher water holding capacities than the finer ones. An attempt has been made to correlate the results obtained, with the potential use in agriculture.

  11. Characterization and possible uses of ashes from wastewater treatment plants

    SciTech Connect (OSTI)

    Merino, Ignacio; Arevalo, Luis F. . E-mail: fromero@ehu.es

    2005-07-01

    This work, on the ashes from the wastewater treatment plant of Galindo (Vizcaya, Spain), has been outlined with the purpose of finding their physico-chemical properties and suggesting possible applications. Ashes contain important quantities of iron, calcium, silica, alumina and phosphates. X-Ray diffraction data make it possible to estimate the mineralogical compositions of the original ashes and also, after thermal treatment at 1200 and 1300 deg. C, the main reactions occurring in thermal treatment. Particle size analysis makes it possible to classify ashes as a very fine powdered material. The thermal treatment leads to a densification of the material and provokes losses of weight mainly due to the elimination of water, carbon dioxide and sulphur trioxide. Application tests show that ashes are not suitable for landfill and similar applications, because of their plastic properties. Testing for pozzolanic character, after the ashes had been heated at 1200 deg. C, did not lead to a strong material probably due to low contents in silica and alumina or to requiring a higher heating temperature. Thermal treatment leads to densification of the material with a considerable increase of compressive strength of the probes. The use of additives (clays and powdered glass) to improve ceramic properties of ashes will be the aim of a future work.

  12. Bioaccumulation Studies Associated with the Kingston Fly Ash Spill, Spring 2009 - Fall 2010

    SciTech Connect (OSTI)

    Adams, Marshall; Brandt, Craig C; Fortner, Allison M

    2012-05-01

    four seasonal collections: Spring 2009, Fall 2009, Spring 2010, and Fall 2010. Both the Spring and Fall studies have focused on 3-4 sentinel fish species that represent different feeding habits, behaviors, and home ranges. In addition to bioaccumulation studies, the Spring investigations also included evaluation of fish health and reproductive integrity on the same fish used for bioaccumulation. Two associated reports present the fish health (Adams et al 2012) and reproductive studies (Greeley et al 2012) conducted in 2009 and 2010. The fish health study conducted in conjunction with the bioaccumulation and reproductive study is critical for assessing and evaluating possible causal relationships between contaminant exposure (bioaccumulation) and the response of fish to exposure as reflected by the various measurements of fish health. This report emphasizes evaluation of arsenic and selenium bioaccumulation in fish and consists of four related studies (Sections 2-5) including, (1) bioaccumulation in liver and ovaries, (2) bioaccumulation in whole body gizzard shad (Dorosoma cepedianum), (3) bioaccumulation in muscle tissue or fillets, and (4) a reconstruction analysis which establishes the relationship between selenium in muscle tissue and that of the whole body of bluegill (Lepomis machrochirus). Metals other than arsenic and selenium are evaluated separately in Section 6. This report focuses on selenium and arsenic for the following reasons: (1) based on baseline studies conducted in early 2009 in the Emory and Clinch River, only two potentially fly-ash related metals, selenium and arsenic, appeared to be elevated above background or reference levels, (2) selenium and arsenic are two of the metals in coal ash that are known to bioaccumulate and cause toxicity in wildlife, and (3) based on bioaccumulation studies of bluegill and carp (Cyprinus carpio) in the Stilling Pond during Spring 2009, which would represent a worst case situation for metal bioaccumulation

  13. Ash formation, deposition, corrosion, and erosion in conventional boilers

    SciTech Connect (OSTI)

    Benson, S.A.; Jones, M.L.

    1995-12-01

    The inorganic components (ash-forming species) associated with coals significantly affect boiler design, efficiency of operation, and lifetimes of boiler parts. During combustion in conventional pulverized fuel boilers, the inorganic components are transformed into inorganic gases, liquids, and solids. This partitioning depends upon the association of the inorganic components in the coal and combustion conditions. The inorganic components are associated as mineral grains and as organically associated elements, and these associations of inorganic components in the fuel directly influence their fate upon combustion. Combustion conditions, such as temperature and atmosphere, influence the volatility and the interaction of inorganic components during combustion and gas cooling, which influences the state and size composition distribution of the particulate and condensed ash species. The intermediate species are transported with the bulk gas flow through the combustion systems, during which time the gases and entrained ash are cooled. Deposition, corrosion, and erosion occur when the ash intermediate species are transported to the heat-transfer surface, react with the surface, accumulate, sinter, and develop strength. Research over the past decade has significantly advanced understanding of ash formation, deposition, corrosion, and erosion mechanisms. Many of the advances in understanding and predicting ash-related issues can be attributed to advanced analytical methods to determine the inorganic composition of fuels and the resulting ash materials. These new analytical techniques have been the key to elucidation of the mechanisms of ash formation and deposition. This information has been used to develop algorithms and computer models to predict the effects of ash on combustion system performance.

  14. Increasing Class C fly ash reduces alkali silica reactivity

    SciTech Connect (OSTI)

    Hicks, J.K.

    2007-07-01

    Contrary to earlier studies, it has been found that incremental additions of Class C fly ash do reduce alkali silica reactivity (ASR), in highly reactive, high alkali concrete mixes. AST can be further reduced by substituting 5% metakaolin or silica fume for the aggregate in concrete mixes with high (more than 30%) Class C fly ash substitution. The paper reports results of studies using Class C fly ash from the Labadie Station plant in Missouri which typically has between 1.3 and 1.45% available alkalis by ASTM C311. 7 figs.

  15. Recovery of iron oxide from coal fly ash

    DOE Patents [OSTI]

    Dobbins, Michael S.; Murtha, Marlyn J.

    1983-05-31

    A high quality iron oxide concentrate, suitable as a feed for blast and electric reduction furnaces is recovered from pulverized coal fly ash. The magnetic portion of the fly ash is separated and treated with a hot strong alkali solution which dissolves most of the silica and alumina in the fly ash, leaving a solid residue and forming a precipitate which is an acid soluble salt of aluminosilicate hydrate. The residue and precipitate are then treated with a strong mineral acid to dissolve the precipitate leaving a solid residue containing at least 90 weight percent iron oxide.

  16. Novel microorganism for selective separation of coal from pyrite and ash. Final report

    SciTech Connect (OSTI)

    Misra, M.; Smith, R.W.

    1995-09-01

    The separation of fine coal from ash and pyrite was evaluated using a microorganism Mycobacterium phlei.

  17. Coal Ash Corrosion Resistant Materials Testing

    SciTech Connect (OSTI)

    D. K. McDonald; P. L. Daniel; D. J. DeVault

    2007-12-31

    In April 1999, three identical superheater test sections were installed into the Niles Unit No.1 for the purpose of testing and ranking the coal ash corrosion resistance of candidate superheater alloys. The Niles boiler burns high sulfur coal (3% to 3.5%) that has a moderate alkali content (0.2% sodium equivalents), thus the constituents necessary for coal ash corrosion are present in the ash. The test sections were controlled to operate with an average surface metal temperature from approximately 1060 F to 1210 F which was within the temperature range over which coal ash corrosion occurs. Thus, this combination of aggressive environment and high temperature was appropriate for testing the performance of candidate corrosion-resistant tube materials. Analyses of the deposit and scale confirmed that aggressive alkali sulfate constituents were present at the metal surface and active in tube metal wastage. The test sections were constructed so that the response of twelve different candidate tube and/or coating materials could be studied. The plan was to remove and evaluate one of the three test sections at time intervals of 1 year, 3 years, and 5 years. This would permit an assessment of performance of the candidate materials as a function of time. Test Section A was removed in November 2001 after about 24 months of service at the desired steam temperature set point, with about 15.5 months of exposure at full temperature. A progress report, issued in October 2002, was written to document the performance of the candidate alloys in that test section. The evaluation described the condition of each tube sample after exposure. It involved a determination of the rate of wall thickness loss for these samples. In cases where there was more than one sample of a candidate material in the test section, an assessment was made of the performance of the alloy as a function of temperature. Test Sections B and C were examined during the November 2001 outage, and it was decided that

  18. Compressive strength of concrete and mortar containing fly ash

    DOE Patents [OSTI]

    Liskowitz, J.W.; Wecharatana, M.; Jaturapitakkul, C.; Cerkanowicz, A.E.

    1998-12-29

    The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction. The invention includes a method for predicting the compressive strength of such a hardenable mixture, which is very important for planning a project. The invention also relates to hardenable mixtures comprising cement and fly ash which can achieve greater compressive strength than hardenable mixtures containing only concrete over the time period relevant for construction. In a specific embodiment, a formula is provided that accurately predicts compressive strength of concrete containing fly ash out to 180 days. In other specific examples, concrete and mortar containing about 15% to 25% fly ash as a replacement for cement, which are capable of meeting design specification required for building and highway construction, are provided. Such materials can thus significantly reduce construction costs. 33 figs.

  19. Compressive strength of concrete and mortar containing fly ash

    DOE Patents [OSTI]

    Liskowitz, John W.; Wecharatana, Methi; Jaturapitakkul, Chai; Cerkanowicz, deceased, Anthony E.

    1997-01-01

    The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction. The invention includes a method for predicting the compressive strength of such a hardenable mixture, which is very important for planning a project. The invention also relates to hardenable mixtures comprising cement and fly ash which can achieve greater compressive strength than hardenable mixtures containing only concrete over the time period relevant for construction. In a specific embodiment, a formula is provided that accurately predicts compressive strength of concrete containing fly ash out to 180 days. In other specific examples, concrete and mortar containing about 15% to 25% fly ash as a replacement for cement, which are capable of meeting design specifications required for building and highway construction, are provided. Such materials can thus significantly reduce construction costs.

  20. Compressive strength of concrete and mortar containing fly ash

    DOE Patents [OSTI]

    Liskowitz, John W.; Wecharatana, Methi; Jaturapitakkul, Chai; Cerkanowicz, deceased, Anthony E.

    1998-01-01

    The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction. The invention includes a method for predicting the compressive strength of such a hardenable mixture, which is very important for planning a project. The invention also relates to hardenable mixtures comprising cement and fly ash which can achieve greater compressive strength than hardenable mixtures containing only concrete over the time period relevant for construction. In a specific embodiment, a formula is provided that accurately predicts compressive strength of concrete containing fly ash out to 180 days. In other specific examples, concrete and mortar containing about 15% to 25% fly ash as a replacement for cement, which are capable of meeting design specification required for building and highway construction, are provided. Such materials can thus significantly reduce construction costs.

  1. Compressive strength of concrete and mortar containing fly ash

    DOE Patents [OSTI]

    Liskowitz, J.W.; Wecharatana, M.; Jaturapitakkul, C.; Cerkanowicz, A.E.

    1997-04-29

    The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction. The invention includes a method for predicting the compressive strength of such a hardenable mixture, which is very important for planning a project. The invention also relates to hardenable mixtures comprising cement and fly ash which can achieve greater compressive strength than hardenable mixtures containing only concrete over the time period relevant for construction. In a specific embodiment, a formula is provided that accurately predicts compressive strength of concrete containing fly ash out to 180 days. In other specific examples, concrete and mortar containing about 15% to 25% fly ash as a replacement for cement, which are capable of meeting design specifications required for building and highway construction, are provided. Such materials can thus significantly reduce construction costs. 33 figs.

  2. Blue Ash, Ohio: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Hide Map This article is a stub. You can help OpenEI by expanding it. Blue Ash is a city in Hamilton County, Ohio. It falls under Ohio's 2nd congressional...

  3. Recoverable immobilization of transuranic elements in sulfate ash

    DOE Patents [OSTI]

    Greenhalgh, Wilbur O.

    1985-01-01

    Disclosed is a method of reversibly immobilizing sulfate ash at least about 20% of which is sulfates of transuranic elements. The ash is mixed with a metal which can be aluminum, cerium, samarium, europium, or a mixture thereof, in amounts sufficient to form an alloy with the transuranic elements, plus an additional amount to reduce the transuranic element sulfates to elemental form. Also added to the ash is a fluxing agent in an amount sufficient to lower the percentage of the transuranic element sulfates to about 1% to about 10%. The mixture of the ash, metal, and fluxing agent is heated to a temperature sufficient to melt the fluxing agent and the metal. The mixture is then cooled and the alloy is separated from the remainder of the mixture.

  4. Transcending Portland Cement with 100 percent fly ash concrete

    SciTech Connect (OSTI)

    Cross, D.; Akin, M.; Stephens, J.; Cuelh, E.

    2009-07-01

    The use of concrete, made with 100% fly ash and no Portland cement, in buildings at the Transportation Institute in Bozeman, MT, USA, is described. 3 refs., 7 figs.

  5. Recovery Act Workers Complete Environmental Cleanup of Coal Ash Basin

    Broader source: Energy.gov [DOE]

    The Savannah River Site (SRS) recently cleaned up a 17-acre basin containing coal ash residues from Cold War operations. The American Recovery and Reinvestment Act project was safely completed at a...

  6. How toxic is coal ash? A laboratory toxicity case study

    SciTech Connect (OSTI)

    Sherrard, Rick M.; Carriker, Neil; Greeley, Jr., Mark Stephen

    2014-12-08

    Under a consent agreement among the Environmental Protection Agency (EPA) and proponents both for and against stricter regulation, EPA is to issue a new coal ash disposal rule by the end of 2014. Laboratory toxicity investigations often yield conservative estimates of toxicity because many standard test species are more sensitive than resident species, thus could provide information useful to the rule-making. However, few laboratory studies of coal ash toxicity are available; most studies reported in the literature are based solely on field investigations. In this paper, we describe a broad range of toxicity studies conducted for the Tennessee Valley Authority (TVA) Kingston ash spill, results of which help provide additional perspective on the toxicity of coal ash.

  7. How toxic is coal ash? A laboratory toxicity case study

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

    Sherrard, Rick M.; Carriker, Neil; Greeley, Jr., Mark Stephen

    2014-12-08

    Under a consent agreement among the Environmental Protection Agency (EPA) and proponents both for and against stricter regulation, EPA is to issue a new coal ash disposal rule by the end of 2014. Laboratory toxicity investigations often yield conservative estimates of toxicity because many standard test species are more sensitive than resident species, thus could provide information useful to the rule-making. However, few laboratory studies of coal ash toxicity are available; most studies reported in the literature are based solely on field investigations. In this paper, we describe a broad range of toxicity studies conducted for the Tennessee Valley Authoritymore » (TVA) Kingston ash spill, results of which help provide additional perspective on the toxicity of coal ash.« less

  8. Some transport properties of the two-channel Kondo impurity

    SciTech Connect (OSTI)

    Schlottmann, P.; Zvyagin, A.A.

    1997-04-01

    We consider conduction electrons moving along a ring in two different orbital channels interacting with a spin-1/2 impurity via isotropic spin exchange. The exchange is the same for both channels, but a crystalline field breaks the orbital symmetry. The tower structure of the finite size corrections to the ground state energy is derived from the Bethe ansatz equations and used to discuss the Aharonov{endash}Bohm{endash}Casher interference pattern in the persistent current and the magnetoresistivity. {copyright} {ital 1997 American Institute of Physics.}

  9. Overview of SOFC Anode Interactions with Coal Gas Impurities

    SciTech Connect (OSTI)

    O. A. Marina; L. R. Pederson; R. Gemmen; K. Gerdes; H. Finklea; I. B. Celik

    2010-03-01

    An overview of the results of SOFC anode interactions with phosphorus, arsenic, selenium, sulfur, antimony, and hydrogen chloride as single contaminants or in combinations is discussed. Tests were performed using both anode- and electrolyte-supported cells in synthetic and actual coal gas for periods greater than 1000 hours. Post-test analyses were performed to identify reaction products formed and their distribution, and compared to phases expected from thermochemical modeling. The ultimate purpose of this work is to establish maximum permissible concentrations for impurities in coal gas, to aid in the selection of appropriate coal gas clean-up technologies.

  10. Overview of SOFC Anode Interactions with Coal Gas Impurities

    SciTech Connect (OSTI)

    Marina, Olga A.; Pederson, Larry R.; Gemmen, Randall; Gerdes, Kirk; Finklea, Harry; Celik, Ismail B.

    2010-05-01

    An overview of the results of SOFC anode interactions with phosphorus, arsenic, selenium, sulfur, antimony, and hydrogen chloride as single contaminants or in combinations is discussed. Tests were performed using both anode- and electrolyte-supported cells in synthetic and actual coal gas for periods greater than 1000 hours. Post-test analyses were performed to identify reaction products formed and their distribution, and compared to phases expected from thermochemical modeling. The ultimate purpose of this work is to establish maximum permissible concentrations for impurities in coal gas, to aid in the selection of appropriate coal gas clean-up technologies.

  11. Ni/YSZ Anode Interactions with Impurities in Coal Gas

    SciTech Connect (OSTI)

    Marina, Olga A.; Pederson, Larry R.; Coyle, Christopher A.; Thomsen, Edwin C.; Coffey, Greg W.

    2009-10-16

    Performance of solid oxide fuel cell (SOFC) with nickel/zirconia anodes on synthetic coal gas in the presence of low levels of phosphorus, arsenic, selenium, sulfur, hydrogen chloride, and antimony impurities were evaluated. The presence of phosphorus and arsenic led to the slow and irreversible SOFC degradation due to the formation of secondary phases with nickel, particularly close to the gas inlet. Phosphorus and antimony surface adsorption layers were identified as well. Hydrogen chloride and sulfur interactions with the nickel were limited to the surface adsorption only, whereas selenium exposure also led to the formation of nickel selenide for highly polarized cells.

  12. Surface Plasma Source Electrode Activation by Surface Impurities

    SciTech Connect (OSTI)

    Dudnikov, Vadim; Han, Baoxi; Johnson, Rolland P.; Murray Jr, S N; Pennisi, Terry R; Santana, Manuel; Stockli, Martin P; Welton, Robert F

    2011-01-01

    In experiments with RF saddle antenna surface plasma sources (SPS), the efficiency of H- ion generation was increased by up to a factor of 5 by long time plasma electrode activation, without adding Cs from Cs supply, by heating the collar to high temperature using hot air flow and plasma discharge. Without cracking or heating the cesium ampoule, but likely with Cs recovery from impurities, the achieved energy efficiency was comparable to that of conventionally cesiated SNS RF sources with an external or internal Cs supply. In the experiments, perfect cesiation was produced (without additional Cs supply) by the collection and trapping of traces of remnant cesium compounds from SPS surfaces.

  13. Minimizing Lubricant-Ash Requirement and Impact on Emission Aftertreatment

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

    Systems via an Oil Conditioning Filter | Department of Energy Minimizing Lubricant-Ash Requirement and Impact on Emission Aftertreatment Systems via an Oil Conditioning Filter Minimizing Lubricant-Ash Requirement and Impact on Emission Aftertreatment Systems via an Oil Conditioning Filter Presentation given at the 2007 Diesel Engine-Efficiency & Emissions Research Conference (DEER 2007). 13-16 August, 2007, Detroit, Michigan. Sponsored by the U.S. Department of Energy's (DOE) Office of

  14. Ash Reduction of Corn Stover by Mild Hydrothermal Preprocessing

    SciTech Connect (OSTI)

    M. Toufiq Reza; Rachel Emerson; M. Helal Uddin; Garold Gresham; Charles J. Coronella

    2014-04-22

    Lignocellulosic biomass such as corn stover can contain high ash content, which may act as an inhibitor in downstream conversion processes. Most of the structural ash in biomass is located in the cross-linked structure of lignin, which is mildly reactive in basic solutions. Four organic acids (formic, oxalic, tartaric, and citric) were evaluated for effectiveness in ash reduction, with limited success. Because of sodium citrates chelating and basic characteristics, it is effective in ash removal. More than 75 % of structural and 85 % of whole ash was removed from the biomass by treatment with 0.1 g of sodium citrate per gram of biomass at 130 C and 2.7 bar. FTIR, fiber analysis, and chemical analyses show that cellulose and hemicellulose were unaffected by the treatment. ICPAES showed that all inorganics measured were reduced within the biomass feedstock, except sodium due to the addition of Na through the treatment. Sodium citrate addition to the preconversion process of corn stover is an effective way to reduced physiological ash content of the feedstock without negatively impacting carbohydrate and lignin content.

  15. Ash level meter for a fixed-bed coal gasifier

    DOE Patents [OSTI]

    Fasching, George E.

    1984-01-01

    An ash level meter for a fixed-bed coal gasifier is provided which utilizes the known ash level temperature profile to monitor the ash bed level. A bed stirrer which travels up and down through the extent of the bed ash level is modified by installing thermocouples to measure the bed temperature as the stirrer travels through the stirring cycle. The temperature measurement signals are transmitted to an electronic signal process system by an FM/FM telemetry system. The processing system uses the temperature signals together with an analog stirrer position signal, taken from a position transducer disposed to measure the stirrer position to compute the vertical location of the ash zone upper boundary. The circuit determines the fraction of each total stirrer cycle time the stirrer-derived bed temperature is below a selected set point, multiplies this fraction by the average stirrer signal level, multiplies this result by an appropriate constant and adds another constant such that a 1 to 5 volt signal from the processor corresponds to a 0 to 30 inch span of the ash upper boundary level. Three individual counters in the processor store clock counts that are representative of: (1) the time the stirrer temperature is below the set point (500.degree. F.), (2) the time duration of the corresponding stirrer travel cycle, and (3) the corresponding average stirrer vertical position. The inputs to all three counters are disconnected during any period that the stirrer is stopped, eliminating corruption of the measurement by stirrer stoppage.

  16. Detection of surface impurity phases in high T.sub.C superconductors using thermally stimulated luminescence

    DOE Patents [OSTI]

    Cooke, D. Wayne; Jahan, Muhammad S.

    1989-01-01

    Detection of surface impurity phases in high-temperature superconducting materials. Thermally stimulated luminescence has been found to occur in insulating impurity phases which commonly exist in high-temperature superconducting materials. The present invention is sensitive to impurity phases occurring at a level of less than 1% with a probe depth of about 1 .mu.m which is the region of interest for many superconductivity applications. Spectroscopic and spatial resolution of the emitted light from a sample permits identification and location of the impurity species. Absence of luminescence, and thus of insulating phases, can be correlated with low values of rf surface resistance.

  17. Batch methods for enriching trace impurities in hydrogen gas for their further analysis

    DOE Patents [OSTI]

    Ahmed, Shabbir; Lee, Sheldon H.D.; Kumar, Romesh; Papdias, Dionissios D.

    2014-07-15

    Provided herein are batch methods and devices for enriching trace quantities of impurities in gaseous mixtures, such as hydrogen fuel. The methods and devices rely on concentrating impurities using hydrogen transport membranes wherein the time period for concentrating the sample is calculated on the basis of optimized membrane characteristics, comprising its thickness and permeance, with optimization of temperature, and wherein the enrichment of trace impurities is proportional to the pressure ratio P.sub.hi/P.sub.lo and the volume ratio V.sub.1/V.sub.2, with following detection of the impurities using commonly-available detection methods.

  18. Effects of Fuel and Air Impurities on PEM Fuel Cell Performance

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

    Hydrogen,Fuel Cells and Infrastructure Technologies 2007 Kickoff Meeting Effects of Fuel and Air Impurities on PEM Fuel Cell Performance Rod Borup Eric Brosha Fernando Garzon (PI) ...

  19. Process for the removal of impurities from combustion fullerenes

    DOE Patents [OSTI]

    Alford, J. Michael; Bolskar, Robert

    2005-08-02

    The invention generally relates to purification of carbon nanomaterials, particularly fullerenes, by removal of PAHs and other hydrocarbon impurities. The inventive process involves extracting a sample containing carbon nanomaterials with a solvent in which the PAHs are substantially soluble but in which the carbon nanomaterials are not substantially soluble. The sample can be repeatedly or continuously extracted with one or more solvents to remove a greater amount of impurities. Preferred solvents include ethanol, diethyl ether, and acetone. The invention also provides a process for efficiently separating solvent extractable fullerenes from samples containing fullerenes and PAHs wherein the sample is extracted with a solvent in which both fullerenes and PAHs are substantially soluble and the sample extract then undergoes selective extraction to remove PAHs. Suitable solvents in which both fullerenes and PAHs are soluble include o-xylene, toluene, and o-dichlorobenzene. The purification process is capable of treating quantities of combustion soot in excess of one kilogram and can produce fullerenes or fullerenic soot of suitable purity for many applications.

  20. When small is big: the role of impurities in electrocatalysis.

    SciTech Connect (OSTI)

    Strmcnik, Dusan; Li, Dongguo; Lopes, Pietro P.; Tripkovic, Dusan; Kodama, Kensaku; Stamenkovic, Vojislav R.; Markovic, Nenad M.

    2015-11-01

    Improvements in the fundamental understanding of electrocatalysis have started to revolutionize the development of electrochemical interfaces for the efficient conversion of chemical energy into electricity, as well as for the utilization of electrons to produce new chemicals that then can be re-used in energy conversion systems. Here, some facets of the role of trace level of impurities (from 10-7 to 10-6 M) in electrocatalysis of the oxygen reduction reaction, hydrogen oxidation and evolution reactions, and CO oxidation reactions are explored on well-characterized platinum single crystal surfaces and high surface area materials in alkaline and acidic environments. Of particular interest is the effect of anions (e.g., Cl-, NO3-) and cations (i.e., Cu2+) present in the supporting electrolytes as well as surface defects (i.e., ad-islands) that are present on metal surfaces. The examples presented are chosen to demonstrate that a small level of impurities may play a crucial role in governing the reactivity of electrochemical interfaces.

  1. Influence of impurity gases and operating conditions on PAFC performance

    SciTech Connect (OSTI)

    Hirai, K.; Iwasa, N.; Suzuki, M.; Okada, O.

    1996-12-31

    On-site Phosphoric Acid Fuel Cell (PAFC) Cogeneration system is installed at various test sites, such as at underground parking lot, within chemical plant premises and near urban streets. Since in the current PAFC system, cathode air is supplied to the cell with no particular pretreatment, impurity gases in the air might influence on cell performance. We have investigated the influence of various impurity gases in the cathode gas, on sub-scale single cells, and have found that NO{sub 2}, SO{sub 2} and toluene affect negatively on cell performance. The results of these experiments and the conceivable mechanism of these effects on cell degradation are reported. We have also investigated the influence of other operating parameters, such as temperature, current density, fuel utilization on cell performance. From these experiments, we have found that operating temperature is a significant factor, which mainly determines cell voltage decline rate. The results of sub-scale single cell tests and a short-stack verification test are also reported.

  2. Concordant plutonium-241-americium-241 dating of environmental samples: results from forest fire ash

    SciTech Connect (OSTI)

    Goldstein, Steven J; Oldham, Warren J; Murrell, Michael T; Katzman, Danny

    2010-12-07

    We have measured the Pu, {sup 237}Np, {sup 241}Am, and {sup 151}Sm isotopic systematics for a set of forest fire ash samples from various locations in the western U.S. including Montana, Wyoming, Idaho, and New Mexico. The goal of this study is to develop a concordant {sup 241}Pu (t{sub 1/2} = 14.4 y)-{sup 241}Am dating method for environmental collections. Environmental samples often contain mixtures of components including global fallout. There are a number of approaches for subtracting the global fallout component for such samples. One approach is to use {sup 242}/{sup 239}Pu as a normalizing isotope ratio in a three-isotope plot, where this ratio for the nonglobal fallout component can be estimated or assumed to be small. This study investigates a new, complementary method of normalization using the long-lived fission product, {sup 151}Sm (t{sub 1/2} = 90 y). We find that forest fire ash concentrates actinides and fission products with {approx}1E10 atoms {sup 239}Pu/g and {approx}1E8 atoms {sup 151}Sm/g, allowing us to measure these nuclides by mass spectrometric (MIC-TIMS) and radiometric (liquid scintillation counting) methods. The forest fire ash samples are characterized by a western U.S. regional isotopic signature representing varying mixtures of global fallout with a local component from atmospheric testing of nuclear weapons at the Nevada Test Site (NTS). Our results also show that {sup 151}Sm is well correlated with the Pu nuclides in the forest fire ash, suggesting that these nuclides have similar geochemical behavior in the environment. Results of this correlation indicate that the {sup 151}Sm/{sup 239}Pu atom ratio for global fallout is {approx}0.164, in agreement with an independent estimate of 0.165 based on {sup 137}Cs fission yields for atmospheric weapons tests at the NTS. {sup 241}Pu-{sup 241}Am dating of the non-global fallout component in the forest fire ash samples yield ages in the late 1950's-early 1960's, consistent with a peak in NTS

  3. Divertor impurity injection using high voltage arcs for impurity transport studies on the Mega Amp Spherical Tokamak

    SciTech Connect (OSTI)

    Leggate, H. J. Turner, M. M.; Lisgo, S. W.; Harrison, J. R.; Elmore, S.; Allan, S. Y.; Gaffka, R. C.; Stephen, R. C.

    2014-12-15

    The operation of next-generation fusion reactors will be significantly affected by impurity transport in the scrape-off layer (SOL). Current modelling efforts are restricted by a lack of detailed data on impurity transport in the SOL. In order to address this, a carbon injector has been designed and installed on the Mega Amp Spherical Tokamak (MAST). The injector creates short lived carbon plumes originating at the MAST divertor lasting less than 50 μs. High voltage capacitor banks are used to create a discharge across concentric carbon electrodes located in a probe mounted on the Divertor Science Facility in the MAST lower divertor. This results in a very short plume duration allowing observation of the evolution of the plume and precise localisation of the plume relative to the X-point on MAST. The emission from the carbon plume was imaged using fast visible cameras filtered in order to isolate the carbon II and carbon III emission lines centered around 514 nm and 465 nm.

  4. Impurity effects on short wavelength ion temperature gradient mode in elongated tokamak plasmas

    SciTech Connect (OSTI)

    Du, Huarong; Wang, Zheng-Xiong; Dong, J. Q.

    2015-02-15

    The effects of impurity ions on the short wavelength ion temperature gradient (SWITG) driven instability in elongated tokamak plasmas are numerically investigated with the gyrokinetic integral eigenmode equation. It is found that for a moderate electron density gradient, the SWITG mode is first destabilized and then stabilized with increasing elongation ?, which is different from the conventional long wavelength ITG mode. For a large electron density gradient, the elongation can effectively stabilize the SWITG mode. Moreover, the low Z impurity ions with inwardly (outwardly) peaked density profiles have stabilizing (destabilizing) effects on the SWITG modes in elongated plasmas. Interestingly, the high Z tungsten impurity ions with inwardly peaked density profiles play a stronger stabilizing role in the SWITG modes than the low Z impurity ions (such as carbon and oxygen) do. In particular, the high Z tungsten impurity ions with a weakly outwardly peaked density profile still have a stabilizing effect. Finally, the critical threshold of impurity density gradient scale length for exciting impurity mode is also numerically obtained, indicating that the impurity mode is harder to be excited in elongated plasmas than in circular ones.

  5. Chloride chemical form in various types of fly ash

    SciTech Connect (OSTI)

    Fenfen Zhu; Masaki Takaoka; Kenji Shiota; Kazuyuki Oshita; Yoshinori Kitajima

    2008-06-01

    Chloride content is a critical problem for the reuse of fly ash as a raw material in cement, and the method used by recyclers to reduce the fly ash chloride content depends on the chemical form of the chlorides. However, limited information is available on the quantitative distribution of chlorides and the identity of some chlorides such as Friedel's salt. We examined chloride forms and percentages using X-ray absorption near edge structure and X-ray diffraction analyses, as well as corresponding washing experiments. Approximately 15% of the chlorine in raw fly ash was estimated to be in the form of NaCl, 10% in KCl, 50% in CaCl{sub 2}, and the remainder in the form of Friedel's salt. Fly ash collected in a bag filter with the injection of calcium hydroxide for acid gas removal (CaFA) contained 35% chlorine as NaCl, 11% as KCl, 37% as CaCl{sub 2}, 13% as Friedel's salt, and the remaining 4% as CaClOH. In fly ash collected in a bag filter with the injection of sodium bicarbonate for acid gas removal (NaFA), approximately 79% of chlorine was in NaCl, 12% was in KCl, and 9% was in Friedel's salt. 25 refs., 4 figs., 4 tabs.

  6. Release of Ammonium and Mercury from NOx Controlled Fly Ash

    SciTech Connect (OSTI)

    Schroeder, K.T.; Cardone, C.R.; Kim, A.G

    2007-07-01

    One of the goals of the Department of Energy is to increase the reuse of coal utilization byproducts (CUB) to 50% by 2010. This will require both developing new markets and maintaining traditional ones such as the use of fly ash in concrete. However, the addition of pollution control devices can introduce side-effects that affect the marketability of the CUB. Such can be the case when NOx control is achieved using selective catalytic or non-catalytic reduction (SCR or SNCR). Depending on site-specific details, the ammonia slip can cause elevated levels of NH3 in the fly ash. Disposal of ammoniated fly ash can present environmental concerns related to the amount of ammonia that might be released, the amount of water that might become contaminated, and the extent to which metals might be mobilized by the presence of the ammonia. Ammonia retained in fly ash appears to be present as either an ammonium salt or as a chemisorbed species. Mercury in the leachates correlated to neither the amount of leachable ammonium nor to the total amount of Hg in the ash. The strongest correlation was between the decreases in the amount of Hg leached with increased LOI.

  7. ADVANCED POWER SYSTEMS ASH BEHAVIOR IN POWER SYSTEMS

    SciTech Connect (OSTI)

    CHRISTOPHER J. ZYGARLICKE; DONALD P. MCCOLLOR; JOHN P. KAY; MICHAEL L. SWANSON

    1998-09-01

    The overall goal of this initiative is to develop fundamental knowledge of ash behavior in power systems for the purpose of increasing power production efficiency, reducing operation and maintenance costs, and reducing greenhouse gas emissions into the atmosphere. The specific objectives of this initiative focus primarily on ash behavior related to advanced power systems and include the following: ? Determine the current status of the fundamental ash interactions and deposition formation mechanisms as already reported through previous or ongoing projects at the EERC or in the literature. ? Determine sintering mechanisms for temperatures and particle compositions that are less well known and remain for the most part undetermined. ? Identify the relationship between the temperature of critical viscosity (Tcv ) as measured in a viscometer and the crystallization occurring in the melt. ? Perform a literature search on the use of heated-stage microscopy (HSM) for examining in situ ash-sintering phenomena and then validate the use of HSM in the determination of viscosity in spherical ash particles. ? Ascertain the formation and stability of specific mineral or amorphous phases in deposits typical of advanced power systems. ? Evaluate corrosion for alloys being used in supercritical combustion systems.

  8. Impurity mixing and radiation asymmetry in massive gas injection simulations of DIII-D

    SciTech Connect (OSTI)

    Izzo, V. A.

    2013-05-15

    Simulations of neon massive gas injection into DIII-D are performed with the 3D MHD code NIMROD. The poloidal and toroidal distribution of the impurity source is varied. This report will focus on the effects of the source variation on impurity mixing and radiated power asymmetry. Even toroidally symmetric impurity injection is found to produce asymmetric radiated power due to asymmetric convective heat flux produced by the 1/1 mode. When the gas source is toroidally localized, the phase relationship between the mode and the source location is important, affecting both radiation peaking and impurity mixing. Under certain circumstances, a single, localized gas jet could produce better radiation symmetry during the disruption thermal quench than evenly distributed impurities.

  9. Ash bed level control system for a fixed-bed coal gasifier

    DOE Patents [OSTI]

    Fasching, George E.; Rotunda, John R.

    1984-01-01

    An ash level control system is provided which incorporates an ash level meter to automatically control the ash bed level of a coal gasifier at a selected level. The ash level signal from the ash level meter is updated during each cycle that a bed stirrer travels up and down through the extent of the ash bed level. The ash level signal is derived from temperature measurements made by thermocouples carried by the stirrer as it passes through the ash bed and into the fire zone immediately above the ash bed. The level signal is compared with selected threshold level signal to determine if the ash level is above or below the selected level once each stirrer cycle. A first counter is either incremented or decremented accordingly. The registered count of the first counter is preset in a down counter once each cycle and the preset count is counted down at a selected clock rate. A grate drive is activated to rotate a grate assembly supporting the ash bed for a period equal to the count down period to maintain the selected ash bed level. In order to avoid grate binding, the controller provides a short base operating duration time each stirrer cycle. If the ash bed level drops below a selected low level or exceeds a selected high level, means are provided to notify the operator.

  10. Cementation and solidification of Rocky Flats Plant incinerator ash

    SciTech Connect (OSTI)

    Phillips, J.A.; Semones, G.B.

    1994-04-01

    Cementation studies on various aqueous waste streams at Rocky Flats have shown this technology to be effective for immobilizing the RCRA constituents in the waste. Cementation is also being evaluated for encapsulation of incinerator ash. Experiments will initially evaluate a surrogate ash waste using a Taguchi experimental design to optimize the cement formulation and waste loading levels for this application. Variables of waste loading, fly ash additions, water/cement ratio, and cement type will be tested at three levels each during the course of this work. Tests will finally be conducted on actual waste using the optimized cement formulation developed from this testing. This progression of tests will evaluate the effectiveness of cement encapsulation for this waste stream without generating any additional wastes.

  11. Structure of the SPRY domain of human Ash2L and its interactions...

    Office of Scientific and Technical Information (OSTI)

    Structure of the SPRY domain of human Ash2L and its interactions with RbBP5 and DPY30 Citation Details In-Document Search Title: Structure of the SPRY domain of human Ash2L and its ...

  12. Ashe County, North Carolina ASHRAE 169-2006 Climate Zone | Open...

    Open Energy Info (EERE)

    Ashe County, North Carolina ASHRAE 169-2006 Climate Zone Jump to: navigation, search County Climate Zone Place Ashe County, North Carolina ASHRAE Standard ASHRAE 169-2006 Climate...

  13. Non-Destructive X-ray Measurement of Soot, Ash, Washcoat and...

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

    X-ray Measurement of Soot, Ash, Washcoat and Regeneration Damage for DPFs Non-Destructive X-ray Measurement of Soot, Ash, Washcoat and Regeneration Damage for DPFs New commercially ...

  14. Geotechnical properties of fly and bottom ash mixtures for use in highway embankments

    SciTech Connect (OSTI)

    Kim, B.; Prezzi, M.; Salgado, R.

    2005-07-01

    Class F fly ash and bottom ash are the solid residue byproducts produced by coal-burning electric utilities. They are usually disposed of together as a waste in utility disposal sites with a typical disposal rate of 80% fly ash and 20% bottom ash. Direct use of these materials in construction projects consuming large volumes of materials, such as highway embankment construction, not only provides a promising solution to the disposal problem, but also an economic alternative to the use of traditional materials. Representative samples of class F fly and bottom ash were collected from two utility power plants in Indiana and tested for their mechanical properties (compaction, permeability, strength, stiffness, and compressibility). Three mixtures of fly and bottom ash with different mixture ratios (i.e., 50, 75, and 100% fly ash content by weight) were prepared for testing. Test results indicated that ash mixtures compare favorably with conventional granular materials.

  15. On the initial state and consistency relations

    SciTech Connect (OSTI)

    Berezhiani, Lasha; Khoury, Justin E-mail: jkhoury@sas.upenn.edu

    2014-09-01

    We study the effect of the initial state on the consistency conditions for adiabatic perturbations. In order to be consistent with the constraints of General Relativity, the initial state must be diffeomorphism invariant. As a result, we show that initial wavefunctional/density matrix has to satisfy a Slavnov-Taylor identity similar to that of the action. We then investigate the precise ways in which modified initial states can lead to violations of the consistency relations. We find two independent sources of violations: i) the state can include initial non-Gaussianities; ii) even if the initial state is Gaussian, such as a Bogoliubov state, the modified 2-point function can modify the q-vector ?0 analyticity properties of the vertex functional and result in violations of the consistency relations.

  16. Ash reduction system using electrically heated particulate matter filter

    DOE Patents [OSTI]

    Gonze, Eugene V [Pinckney, MI; Paratore, Jr., Michael J; He, Yongsheng [Sterling Heights, MI

    2011-08-16

    A control system for reducing ash comprises a temperature estimator module that estimates a temperature of an electrically heated particulate matter (PM) filter. A temperature and position estimator module estimates a position and temperature of an oxidation wave within the electrically heated PM filter. An ash reduction control module adjusts at least one of exhaust flow, fuel and oxygen levels in the electrically heated PM filter to adjust a position of the oxidation wave within the electrically heated PM filter based on the oxidation wave temperature and position.

  17. High-performance, high-volume fly ash concrete

    SciTech Connect (OSTI)

    2008-01-15

    This booklet offers the construction professional an in-depth description of the use of high-volume fly ash in concrete. Emphasis is placed on the need for increased utilization of coal-fired power plant byproducts in lieu of Portland cement materials to eliminate increased CO{sub 2} emissions during the production of cement. Also addressed is the dramatic increase in concrete performance with the use of 50+ percent fly ash volume. The booklet contains numerous color and black and white photos, charts of test results, mixtures and comparisons, and several HVFA case studies.

  18. Continuous air agglomeration method for high carbon fly ash beneficiation

    DOE Patents [OSTI]

    Gray, McMahon L.; Champagne, Kenneth J.; Finseth, Dennis H.

    2000-01-01

    The carbon and mineral components of fly ash are effectively separated by a continuous air agglomeration method, resulting in a substantially carboree mineral stream and a highly concentrated carbon product. The method involves mixing the fly ash comprised of carbon and inorganic mineral matter with a liquid hydrocarbon to form a slurry, contacting the slurry with an aqueous solution, dispersing the hydrocarbon slurry into small droplets within the aqueous solution by mechanical mixing and/or aeration, concentrating the inorganic mineral matter in the aqueous solution, agglomerating the carbon and hydrocarbon in the form of droplets, collecting the droplets, separating the hydrocarbon from the concentrated carbon product, and recycling the hydrocarbon.

  19. The Sensitivity of DPF Performance to the Spatial Distribution of Ash Generated from Six Lubricant Formulations

    Broader source: Energy.gov [DOE]

    Discusses potential of DPF pressure drop reduction by optimizing the spatial distribution of ash inside DPF inlet channel

  20. Comparison of leaching characteristics of heavy metals from bottom and fly ashes in Korea and Japan

    SciTech Connect (OSTI)

    Shim, Young-Sook; Rhee, Seung-Whee; Lee, Woo-Keun . E-mail: woklee@kangwon.ac.kr

    2005-07-01

    The objective of this research was to compare the leaching characteristics of heavy metals such as cadmium, chromium, copper, nickel, lead, etc., in Korean and Japanese municipal solid waste incineration (MSWI) ash. The rate of leaching of heavy metal was measured by KSLT and JTL-13, and the amount of heavy metals leached was compared with the metal content in each waste component. Finally, bio-availability testing was performed to assess the risks associated with heavy metals leached from bottom ash and fly ash. From the results, the value of neutralization ability in Japanese fly ash was four times higher than that in Korean fly ash. The reason was the difference in the content of Ca(OH){sub 2} in fly ash. The amount of lead leached exceeded the regulatory level in both Japanese and Korean fly ash. The rate of leaching was relatively low in ash with a pH in the range of 6-10. The bio-availability test in fly ash demonstrated that the amount of heavy metals leached was Pb > Cd > Cr, but the order was changed to Pb > Cr > Cd in the bottom ash. The leaching concentration of lead exceeded the Japanese risk level in all fly ashes from the two countries, but the leaching concentration of cadmium exceeded the regulatory level in Korean fly ash only.

  1. Hydration and strength development of binder based on high-calcium oil shale fly ash

    SciTech Connect (OSTI)

    Freidin, C. [Ben-Gurion Univ. of the Negev, Sede-Boqer (Israel)] [Ben-Gurion Univ. of the Negev, Sede-Boqer (Israel)

    1998-06-01

    The properties of high-calcium oil shale fly ash and low-calcium coal fly ash, which are produced in Israeli power stations, were investigated. High-calcium oil shale fly ash was found to contain a great amount of CaO{sub free} and SO{sub 3} in the form of lime and anhydrite. Mixtures of high-calcium oil shale fly ash and low-calcium coal fly ash, termed fly ash binder, were shown to cure and have improved strength. The influence of the composition and curing conditions on the compressive strength of fly ash binders was examined. The microstructure and the composition of fly ash binder after curing and long-term exposure in moist air, water and open air conditions were studied. It was determined that ettringite is the main variable in the strength and durability of cured systems. The positive effect of calcium silicate hydrates, CSH, which are formed by interaction of high-calcium oil shale fly ash and low-calcium coal fly ash components, on the carbonation and dehydration resistance of fly ash binder in open air is pronounced. It was concluded that high-calcium oil shale fly ash with high CaO{sub free} and SO{sub 3} content can be used as a binder for building products.

  2. EFFECT OF IMPURITIES ON THE PERFORMANCE OF A Pd-Ag DIFFUSER

    SciTech Connect (OSTI)

    Morgan, G.

    2010-12-16

    A commercially fabricated diffuser purchased from Johnson-Matthey, Inc. was evaluated for performance characterization testing at the Savannah River National Laboratory (SRNL). Different impurities are often present in the feed streams of the process diffusers, but the effect of these impurities on the diffuser performance is currently unknown. Various impurities were introduced into the feed stream of the diffuser at various levels ranging from 0.5% to 10% of the total flow in order to determine the effect that these impurities have on the permeation of hydrogen through the palladium-silver membrane. The introduction of various impurities into the feed stream of the diffuser had a minimal effect on the overall permeation of hydrogen through the Pd-Ag membrane. Of the four impurities introduced into the feed stream, carbon monoxide (CO) was the only impurity that showed any evidence of causing a reduction in the amount of hydrogen permeating through the Pd-Ag membrane. The hydrogen permeation returned to its baseline level after the CO was removed from the feed stream. There were no lasting effects of the CO exposure on the ability of the membrane to effectively separate hydrogen from the non-hydrogen species in the gas stream under the conditions tested.

  3. Self-degradable Slag/Class F Fly Ash-Blend Cements

    SciTech Connect (OSTI)

    Sugama, T.; Warren, J.; Butcher, T.; Lance Brothers; Bour, D.

    2011-03-01

    Self-degradable slag/Class F fly ash blend pozzolana cements were formulated, assuming that they might serve well as alternative temporary fracture sealers in Enhanced Geothermal System (EGS) wells operating at temperatures of {ge} 200 C. Two candidate formulas were screened based upon material criteria including an initial setting time {ge} 60 min at 85 C, compressive strength {ge} 2000 psi for a 200 C autoclaved specimen, and the extent of self-degradation of cement heated at {ge} 200 C for it was contacted with water. The first screened dry mix formula consisted of 76.5 wt% slag-19.0 wt% Class F fly ash-3.8 wt% sodium silicate as alkali activator, and 0.7 wt% carboxymethyl cellulose (CMC) as the self-degradation promoting additive, and second formula comprised of 57.3 wt% slag, 38.2 wt% Class F fly ash, 3.8 wt% sodium silicate, and 0.7 wt% CMC. After mixing with water and autoclaving it at 200 C, the aluminum-substituted 1.1 nm tobermorite crystal phase was identified as hydrothermal reaction product responsible for the development of a compressive strength of 5983 psi. The 200 C-autoclaved cement made with the latter formula had the combined phases of tobermorite as its major reaction product and amorphous geopolymer as its minor one providing a compressive strength of 5271 psi. Sodium hydroxide derived from the hydrolysis of sodium silicate activator not only initiated the pozzolanic reaction of slag and fly ash, but also played an important role in generating in-situ exothermic heat that significantly contributed to promoting self-degradation of cementitious sealers. The source of this exothermic heat was the interactions between sodium hydroxide, and gaseous CO{sub 2} and CH{sub 3}COOH by-products generated from thermal decomposition of CMC at {ge} 200 C in an aqueous medium. Thus, the magnitude of this self-degradation depended on the exothermic temperature evolved in the sealer; a higher temperature led to a sever disintegration of sealer. The exothermic

  4. Method and apparatus for detecting and measuring trace impurities in flowing gases

    DOE Patents [OSTI]

    Taylor, Gene W.; Dowdy, Edward J.

    1979-01-01

    Trace impurities in flowing gases may be detected and measured by a dynamic atomic molecular emission spectrograph utilizing as its energy source the energy transfer reactions of metastable species, atomic or molecular, with the impurities in the flowing gas. An electronically metastable species which maintains a stable afterglow is formed and mixed with the flowing gas in a region downstream from and separate from the region in which the metastable species is formed. Impurity levels are determined quantitatively by the measurement of line and/or band intensity as a function of concentration employing emission spectroscopic techniques.

  5. Impurity detection in the APEX tokamak by in-situ doppler shift laser fluorescence spectroscopy

    SciTech Connect (OSTI)

    Pellin, M.J.; Young, C.E.; Gruen, D.M.; Norem, J.H.

    1981-01-01

    Laser fluorescence spectroscopy (LFS) is a promising impurity atoms generated from surfaces exposed to fusion plasmas. Here the first continuous wave laser fluorescene measurement of impurities generated during a single tokamak pulse is reported. The results point out the promise of LFS as an essentially real time, in-situ diagnostic allowing a detailed comparison of impurity generation and transport with Tokamak parameters and operating conditions. Results presented will include the Zr-atom density and velocity distribution produced from a Zr-metal target during an Apex Tokamak discharge.

  6. Magnetic field induced quantum phase transitions in the two-impurity Anderson model

    SciTech Connect (OSTI)

    Zhu, Lujun; Zhu, Jian - Xin

    2010-11-17

    In the two-impurity Anderson model, the inter-impurity spin exchange interaction favors a spin singlet state between two impurities leading to the localization of quasiparticles. We show that a local uniform magnetic field can delocalize the quasiparticies to restore the Kondo resonance. This transition is found to be continuous, accompanied by not only the divergence of the staggered (anti ferromagnetic) susceptibility, but also the divergence of the uniform spin susceptibility. This implies that the magnetic field induced quantum phase transitions in Kondo systems are in favor of the local critical type.

  7. Transient electron heat diffusivity obtained from trace impurity injection on TFTR

    SciTech Connect (OSTI)

    Kissick, M. W.; Fredrickson, E. D.; Callen, J. D.; Bush, C. E.; Chang, Z. Y.; Efthimion, P. C.; Hulse, R. A.; Mansfield, D. K.; Park, H. K.; Schivell, J.; Scott, S. D.; Synakowski, E. J.; Taylor, G.; Zarnstorff, M. C.

    1993-08-01

    A new method for obtaining a transient (``pulse``) electron heat diffusivity (?ep) in the radial region 0.38 < r/a < 0.56 in TFTR L-mode discharges is presented. Small electron temperature perturbations were caused by single bursts of injected impurities which radiated and cooled the plasma edge. An iron injection case by laser ablation was found to be more definitive than a supporting helium gas puff case. In this new ``cold pulse`` method, we concentrate on modeling just the electron temperature perturbations, tracked with ECE (electron cyclotron emission) diagnostics and on being able to justify separation in space and time from the cooling source. This ?ep is obtained for these two cases to be ?ep = (6.0m/s 35%) ~ 4?e(power balance) which is consistent with, but more definitive than, results from other studies that are more susceptible to ambiguities in the source profile.

  8. Distribution of polycyclic aromatic hydrocarbons in lime spray dryer ash

    SciTech Connect (OSTI)

    Ping Sun; Panuwat Taerakul; Linda K. Weavers; Harold W. Walker

    2005-10-01

    Four lime spray dryer (LSD) ash samples were collected from a spreader stoker boiler and measured for their concentrations of 16 U.S. EPA specified polycyclic aromatic hydrocarbons (PAHs). Results showed that the total measured PAH concentration correlated with the organic carbon content of the LSD ash. Each LSD ash sample was then separated using a 140 mesh sieve into two fractions: a carbon-enriched fraction ({gt}140 mesh) and a lime-enriched fraction ({lt}140 mesh). Unburned carbon was further separated from the carbon-enriched fraction with a lithiumheteropolytungstate (LST) solution. PAH measurements on these different fractions showed that unburned carbon had the highest PAH concentrations followed by the carbon-enriched fraction, indicating that PAHs were primarily associated with the carbonaceous material in LSD ash. However, detectable levels of PAHs were also found in the lime-enriched fraction, suggesting that the fine spray of slaked lime may sorb PAH compounds from the flue gas in the LSD process. 37 refs., 5 figs., 4 tabs.

  9. The quantitative ion exchange separation of uranium from impurities

    SciTech Connect (OSTI)

    Narayanan, U.I.; Mason, P.B.; Zebrowski, J.P.; Rocca, M.; Frank, I.W.; Smith, M.M.; Johnson, K.D.; Orlowicz, G.J.; Dallmann, E.

    1995-03-01

    Two methods were tested for the quantitative separation of uranium from elemental impurities using commercially available resins. The sorption and elution behavior of uranium and the separation of it from a variety of other elements was studied. The first method utilized an anion exchange resin while the second method employed an extraction resin. The first method, the anion exchange of uranium (VI) in an acid chloride medium, was optimized and statistically tested for quantitative recovery of uranium. This procedure involved adsorption of uranium onto Blo-Rad AG 1-X8 or MP-1 ion exchange resins in 8 M HCl, separation of uncompleted or weakly complexed matrix ions with an 8 M HCI wash, and subsequent elution of uranium with 1 M HCl. Matrix ions more strongly adsorbed than uranium were left on the resin. Uranium recoveries with this procedure averaged greater than 99.9% with a standard deviation of 0.1%. In the second method, recovery of uranium on the extraction resin did not meet the criteria of this study and further examination was terminated.

  10. Analysis methods for fast impurity ion dynamics data

    SciTech Connect (OSTI)

    Den Hartog, D.J.; Almagri, A.F.; Prager, S.C.; Fonck, R.J.

    1994-08-01

    A high resolution spectrometer has been developed and used on the MST reversed-field pinch (RFP) to measure passively impurity ion temperatures and flow velocities with 10 {mu}s temporal resolution. Such measurements of MHD-scale fluctuations are particularly relevant in the RFP because the flow velocity fluctuation induced transport of current (the ``MHD dynamo``) may produce the magnetic field reversal characteristic of an RFP. This instrument will also be used to measure rapid changes in the equilibrium flow velocity, such as occur during locking and H-mode transition. The precision of measurements made to date is <0.6 km/s. The authors are developing accurate analysis techniques appropriate to the reduction of this fast ion dynamics data. Moment analysis and curve-fitting routines have been evaluated for noise sensitivity and robustness. Also presented is an analysis method which correctly separates the flux-surface average of the correlated fluctuations in u and B from the fluctuations due to rigid shifts of the plasma column.

  11. Impurity-doped optical shock, detonation and damage location sensor

    DOE Patents [OSTI]

    Weiss, Jonathan D.

    1995-01-01

    A shock, detonation, and damage location sensor providing continuous fiber-optic means of measuring shock speed and damage location, and could be designed through proper cabling to have virtually any desired crush pressure. The sensor has one or a plurality of parallel multimode optical fibers, or a singlemode fiber core, surrounded by an elongated cladding, doped along their entire length with impurities to fluoresce in response to light at a different wavelength entering one end of the fiber(s). The length of a fiber would be continuously shorted as it is progressively destroyed by a shock wave traveling parallel to its axis. The resulting backscattered and shifted light would eventually enter a detector and be converted into a proportional electrical signals which would be evaluated to determine shock velocity and damage location. The corresponding reduction in output, because of the shortening of the optical fibers, is used as it is received to determine the velocity and position of the shock front as a function of time. As a damage location sensor the sensor fiber cracks along with the structure to which it is mounted. The size of the resulting drop in detector output is indicative of the location of the crack.

  12. Impurity-doped optical shock, detonation and damage location sensor

    DOE Patents [OSTI]

    Weiss, J.D.

    1995-02-07

    A shock, detonation, and damage location sensor providing continuous fiber-optic means of measuring shock speed and damage location, and could be designed through proper cabling to have virtually any desired crush pressure. The sensor has one or a plurality of parallel multimode optical fibers, or a singlemode fiber core, surrounded by an elongated cladding, doped along their entire length with impurities to fluoresce in response to light at a different wavelength entering one end of the fiber(s). The length of a fiber would be continuously shorted as it is progressively destroyed by a shock wave traveling parallel to its axis. The resulting backscattered and shifted light would eventually enter a detector and be converted into a proportional electrical signals which would be evaluated to determine shock velocity and damage location. The corresponding reduction in output, because of the shortening of the optical fibers, is used as it is received to determine the velocity and position of the shock front as a function of time. As a damage location sensor the sensor fiber cracks along with the structure to which it is mounted. The size of the resulting drop in detector output is indicative of the location of the crack. 8 figs.

  13. Thermal Analysis of Surrogate Simulated Molten Salts with Metal Chloride Impurities for Electrorefining Used Nuclear Fuel

    SciTech Connect (OSTI)

    Toni Y. Gutknecht; Guy L. Fredrickson; Vivek Utgikar

    2012-04-01

    This project is a fundamental study to measure thermal properties (liquidus, solidus, phase transformation, and enthalpy) of molten salt systems of interest to electrorefining operations, which are used in both the fuel cycle research & development mission and the spent fuel treatment mission of the Department of Energy. During electrorefining operations the electrolyte accumulates elements more active than uranium (transuranics, fission products and bond sodium). The accumulation needs to be closely monitored because the thermal properties of the electrolyte will change as the concentration of the impurities increases. During electrorefining (processing techniques used at the Idaho National Laboratory to separate uranium from spent nuclear fuel) it is important for the electrolyte to remain in a homogeneous liquid phase for operational safeguard and criticality reasons. The phase stability of molten salts in an electrorefiner may be adversely affected by the buildup of fission products in the electrolyte. Potential situations that need to be avoided are: (i) build up of fissile elements in the salt approaching the criticality limits specified for the vessel (ii) freezing of the salts due to change in the liquidus temperature and (iii) phase separation (non-homogenous solution) of elements. The stability (and homogeneity) of the phases can potentially be monitored through the thermal characterization of the salts, which can be a function of impurity concentration. This work describes the experimental results of typical salts compositions, consisting of chlorides of strontium, samarium, praseodymium, lanthanum, barium, cerium, cesium, neodymium, sodium and gadolinium (as a surrogate for both uranium and plutonium), used in the processing of used nuclear fuels. Differential scanning calorimetry was used to analyze numerous salt samples providing results on the thermal properties. The property of most interest to pyroprocessing is the liquidus temperature. It was

  14. Soil stabilization and pavement recycling with self-cementing coal fly ash

    SciTech Connect (OSTI)

    2008-01-15

    This manual provides design information for self-cementing coal fly ash as the sole stabilizing agent for a wide range of engineering applications. As in any process, the application of sound engineering practices, appropriate testing, and evaluation of fly ash quality and characteristics will lend themselves to successful projects using the guidelines in this manual. Topics discussed include: self-cementing coal fly ash characteristics; laboratory mix design; stabilization of clay soils; stabilisation of granular materials; construction considerations; high sulfate ash; environmental considerations for fly ash stabilization; design considerations; state specification/guidelines/standards; and a sample of a typical stabilization specification.

  15. Mechanical characterization of filler sandcretes with rice husk ash additions. Study applied to Senegal

    SciTech Connect (OSTI)

    Cisse, I.K.; Laquerbe, M.

    2000-01-01

    To capitalize on the local materials of Senegal (agricultural and industrial wastes, residual fines from crushing process, sands from dunes, etc.), rise husk ash and residues of industrial and agricultural wastes have been used as additions in sandcretes. The mechanical resistance of sandcrete blocks obtained when unground ash (and notably the ground ash) is added reveals that there is an increase in performance over the classic mortar blocks. In addition, the use of unground rice husk ash enables production of a lightweight sandcrete with insulating properties, at a reduced cost. The ash pozzolanic reactivity explains the high strengths obtained.

  16. Parallel transport studies of high-Z impurities in the core of...

    Office of Scientific and Technical Information (OSTI)

    described by a combination of centrifugal, poloidal electric field, and ion-impurity friction effects. Updown asymmetries, -0.05<0.10, are observed over 0.5<0.9 with nsub...

  17. Carbon impurities on graphene synthesized by chemical vapor deposition on platinum

    SciTech Connect (OSTI)

    Ping, Jinglei; Fuhrer, Michael S., E-mail: michael.fuhrer@monash.edu [Center for Nanophysics and Advanced Materials, University of Maryland, College Park, Maryland 20742-4111, USA and School of Physics, Monash University, 3800 Victoria (Australia)

    2014-07-28

    We report nanocrystalline carbon impurities coexisting with graphene synthesized via chemical vapor deposition on platinum. For certain growth conditions, we observe micron-size island-like impurity layers which can be mistaken for second graphene layers in optical microscopy or scanning electron microscopy. The island orientation depends on the crystalline orientation of the Pt, as shown by electron backscatter diffraction, indicating growth of carbon at the platinum surface below graphene. Dark-field transmission electron microscopy indicates that in addition to uniform single-crystal graphene, our sample is decorated with nanocrystalline carbon impurities with a spatially inhomogeneous distribution. The impurity concentration can be reduced significantly by lowering the growth temperature. Raman spectra show a large D peak, however, electrical characterization shows high mobility (?8000?cm{sup 2}/Vs), indicating a limitation for Raman spectroscopy in characterizing the electronic quality of graphene.

  18. Webinar: Impacts of Impurities on Hydrogen Assisted Fatigue Crack Growth in Structural Steels

    Broader source: Energy.gov [DOE]

    The Energy Department will present a live webinar titled "Impacts of Impurities on Hydrogen Assisted Fatigue Crack Growth in Structural Steels" on Tuesday, January 12, from 12 to 1 p.m. EST.

  19. Automated system for removal and pneumatic transport of fly ash from electric precipitator hoppers

    SciTech Connect (OSTI)

    V.K. Konovalov; O.V. Yashkin; V.V. Ermakov

    2008-03-15

    A system for removal and pneumatic transport of fly ash is examined, in which air pulses act on batches (pistons) of ash formed in a duct. Studies are made of the effect of several physical parameters on the force required to displace a piston of ash and these serve as a basis for choosing a system for removal and pneumatic transport of ash simultaneously from several hoppers of an electric precipitator. This makes it possible to separate the ash particles according to size without introducing additional components. Formulas are given for calculating the structural and dynamic parameters of this system and measurements of indirect dynamic parameters are used to calculate the input-output characteristics of the system. In order to optimize the system, configurations for summing several ducts into a single transport duct for pneumatic ash transport are proposed. Some variants of dry ash utilization and the advantages of producing of size-separated particles are considered.

  20. Regeneratively cooled coal combustor/gasifier with integral dry ash removal

    DOE Patents [OSTI]

    Beaufrere, A.H.

    1982-04-30

    A coal combustor/gasifier is disclosed which produces a low or medium combustion gas fired furnances or boilers. Two concentric shells define a combustion air flows to provide regenerative cooling of the inner shell for dry ash operation. A fuel flow and a combustion air flow having opposed swirls are mixed and burned in a mixing-combustion portion of the combustion volume and the ash laden combustion products flow with a residual swirl into an ash separation region. The ash is cooled below the fusion temperature and is moved to the wall by centrifugal force where it is entrained in the cool wall boundary layer. The boundary layer is stabilized against ash re-entrainment as it is moved to an ash removal annulus by a flow of air from the plenum through slots in the inner shell, and by suction on an ash removal skimmer slot.

  1. Method for increasing the rate of compressive strength gain in hardenable mixtures containing fly ash

    DOE Patents [OSTI]

    Liskowitz, John W.; Wecharatana, Methi; Jaturapitakkul, Chai; Cerkanowicz, deceased, Anthony E.

    1997-01-01

    The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction. The invention provides a method for increasing the rate of strength gain of a hardenable mixture containing fly ash by exposing the fly ash to an aqueous slurry of calcium oxide (lime) prior to its incorporation into the hardenable mixture. The invention further relates to such hardenable mixtures, e.g., concrete and mortar, that contain fly ash pre-reacted with calcium oxide. In particular, the fly ash is added to a slurry of calcium oxide in water, prior to incorporating the fly ash in a hardenable mixture. The hardenable mixture may be concrete or mortar. In a specific embodiment, mortar containing fly ash treated by exposure to an aqueous lime slurry are prepared and tested for compressive strength at early time points.

  2. Method for increasing the rate of compressive strength gain in hardenable mixtures containing fly ash

    DOE Patents [OSTI]

    Liskowitz, J.W.; Wecharatana, M.; Jaturapitakkul, C.; Cerkanowicz, A.E.

    1997-10-28

    The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction. The invention provides a method for increasing the rate of strength gain of a hardenable mixture containing fly ash by exposing the fly ash to an aqueous slurry of calcium oxide (lime) prior to its incorporation into the hardenable mixture. The invention further relates to such hardenable mixtures, e.g., concrete and mortar, that contain fly ash pre-reacted with calcium oxide. In particular, the fly ash is added to a slurry of calcium oxide in water, prior to incorporating the fly ash in a hardenable mixture. The hardenable mixture may be concrete or mortar. In a specific embodiment, mortar containing fly ash treated by exposure to an aqueous lime slurry are prepared and tested for compressive strength at early time points. 2 figs.

  3. Gate-modulated conductance of few-layer WSe{sub 2} field-effect transistors in the subgap regime: Schottky barrier transistor and subgap impurity states

    SciTech Connect (OSTI)

    Wang, Junjie; Feng, Simin; Rhodes, Daniel; Balicas, Luis; Nguyen, Minh An T.; Watanabe, K.; Taniguchi, T.; Mallouk, Thomas E.; Terrones, Mauricio; Zhu, J.

    2015-04-13

    Two key subjects stand out in the pursuit of semiconductor research: material quality and contact technology. The fledging field of atomically thin transition metal dichalcogenides (TMDCs) faces a number of challenges in both efforts. This work attempts to establish a connection between the two by examining the gate-dependent conductance of few-layer (1-5L) WSe{sub 2} field effect devices. Measurements and modeling of the subgap regime reveal Schottky barrier transistor behavior. We show that transmission through the contact barrier is dominated by thermionic field emission (TFE) at room temperature, despite the lack of intentional doping. The TFE process arises due to a large number of subgap impurity states, the presence of which also leads to high mobility edge carrier densities. The density of states of such impurity states is self-consistently determined to be approximately 1–2 × 10{sup 13}/cm{sup 2}/eV in our devices. We demonstrate that substrate is unlikely to be a major source of the impurity states and suspect that lattice defects within the material itself are primarily responsible. Our experiments provide key information to advance the quality and understanding of TMDC materials and electrical devices.

  4. Influence of metal(loid) bioaccumulation and maternal transfer on embryo-larval development in fish exposed to a major coal ash spill

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

    Greeley, Jr., Mark Stephen; Adams, S. Marshall; Elmore, Logan R.; McCracken, Mary Kitty

    2016-01-03

    this and related studies associated with the Kingston coal ash spill are consistent with proposed USEPA fish-based water quality criteria for Se, and to date continue to suggest that long-term exposures to sediment containing residual ash may not present a significant chronic risk to fish populations exposed to this major coal ash release.« less

  5. Influence of impurities on the solid-solid phase transitions in zirconium

    SciTech Connect (OSTI)

    Rigg, Paulo A; Greeff, Carl W; Gray, George T., III; Knudson, Marcus D

    2009-08-04

    In an effort to better understand the influence of impurities on the solid-solid phase transitions in Group IVb metals, experiments have been carried out on polycrystalline zirconium samples using plate impact and isentropic loading techniques. Samples with three levels of impurities were shock-loaded using both gas and powder-driven guns and isentropically loaded using magnetic drive (Sandia's Z-Machine) to determine the properties and characteristics of both the {alpha} {yields} {omega} and {omega} {yields} {beta} transitions.

  6. Final Report - Effects of Impurities on Fuel Cell Performance and Durability

    SciTech Connect (OSTI)

    Trent Molter

    2012-08-18

    This program is focused on the experimental determination of the effects of key hydrogen side impurities on the performance of PEM fuel cells. Experimental data has been leveraged to create mathematical models that predict the performance of PEM fuel cells that are exposed to specific impurity streams. These models are validated through laboratory experimentation and utilized to develop novel technologies for mitigating the effects of contamination on fuel cell performance. Results are publicly disseminated through papers, conference presentations, and other means.

  7. Contact formation and gettering of precipitated impurities by multiple firing during semiconductor device fabrication

    DOE Patents [OSTI]

    Sopori, Bhushan

    2014-05-27

    Methods for contact formation and gettering of precipitated impurities by multiple firing during semiconductor device fabrication are provided. In one embodiment, a method for fabricating an electrical semiconductor device comprises: a first step that includes gettering of impurities from a semiconductor wafer and forming a backsurface field; and a second step that includes forming a front contact for the semiconductor wafer, wherein the second step is performed after completion of the first step.

  8. Structure and vibrations of different charge Ge impurity in α-quartz

    SciTech Connect (OSTI)

    Kislov, A. N. Mikhailovich, A. P. Zatsepin, A. F.

    2014-10-21

    Atomic structure and localized vibrations of α‐SiO{sub 2}:Ge are studied using computer modeling techniques. The simulation was carried out by the lattice dynamics calculation of the local density of vibrational states. Local structures parameters are calculated, localized symmetrized vibrations frequency caused by Ge impurity in different charge states are defined. The movements of atoms located near Ge impurity are analyzed and their contribution into localized vibrations of different type is evaluated.

  9. Brick manufacture with fly ash from Illinois coals. Technical report, March 1, 1995--May 31, 1995

    SciTech Connect (OSTI)

    Hughes, R.E.; Dreher, G.; Moore, D.; Rostam-Abadi, M.; Fiocchi, T.; Swartz, D.

    1995-12-31

    This investigation seeks to utilize fly ash in fired-clay products such as building and patio bricks, ceramic blocks, field and sewer tile, and flower pots. This goal is accomplished by 1) one or more plant-scale, 5000-brick tests of fly ash mixed with brick clays at the 20% or higher level; 2) a laboratory-scale study to measure the firing reactions of a range of compositions of clay and fly ash mixtures; 3) a preliminary study to evaluate the potential environmental and economic benefits of brick manufacture with fly ash. Bricks and feed materials will be tested for compliance with market specifications and for leachability of pollutants derived from fly ash. The laboratory study will combine ISGS databases, ICCI-supported characterization methods, and published information to improve predictions of the firing characteristics of Illinois fly ash and brick clay mixtures. Because identical methods are used to test clay firing and coal ash fusion, and because melting mechanisms are the same, improved coal ash fusion predictions are and additional expected result of this research. During this quarter we completed a manufacturing run at Colonial Brick Co. and began laboratory testing of samples from that run: clays, fly ash (from Illinois Power Company`s Wood River plant), and green and fired bricks, with and without fly ash. Bricks with 20% fly ash ``scummed`` during firing, and the fly ash failed to increase oxidation rate or water absorption, which were both expected. We obtained chemical and mineralogical analyses of the fireclays and shales at Colonial and Marseilles Brick Companies and began a series of selective dissolution analyses to more accurately determine the composition of the principal clay minerals in brick clays and the components in fly ash. We began related work of calculating normative mineralogical analyses for all clays and fly ashes that we sample.

  10. Determination of slagging behavior of various coal ash samples by using DTF

    SciTech Connect (OSTI)

    Kim, H.T.; Choi, B.C.; Park, S.W.

    1999-07-01

    The objective of this study is to investigate slagging behavior of various ash samples with the conjunction to the properties of ashes and original coal such as concentration of each ash components, ash slagging temperature and slag viscosity. To simulate actual ash melting condition in coal combustion as well as gasification, DTF (drop tube furnace) is utilized for the acquisition of slag sample with different reaction condition. The sampled slag is photographed for the visual inspection and the shape of the slag is evaluated with ash properties. The sampled ash slag is also analyzed with XRD for the determination of phase transition during the ash melting. Furthermore, coal ashes are processed with Ash Fusion Determinator for the fusion temperature and High-Temperature Viscometer for the slag viscosity. Such ash-related properties are also determined by empirical formulation for the refinement of the result. So far, three different coal samples, Alaska, Datong, Cyprus are investigated. For the 3 ash samples, slag formation shows similar shape in combustion as well as gasification condition and completely different shape with different coal types. Alaska slag, which represents higher fluidity, is penetrated into alumina disk so that small half-cone shape of slag is produced. However, Cyprus slag is formed with more circular shape of sphere and Datong slag represents an in-between shape. More coal samples will be studied for the determination of slag behavior. The shape data will be analyzed with ash composition, fluidity behavior and ash fusion determination of original coal. Such relationship will be the baseline to determine the operation parameter of slag removal in the 3 ton/day coal gasifier located in the Ajou University, Suwon, Korea.

  11. The Effect of Impurities on the Processing of Aluminum Alloys

    SciTech Connect (OSTI)

    Zi-Kui Liu; Shengjun Zhang; Qingyou Han; Vinod Sikka

    2007-04-23

    For this Aluminum Industry of the Future (IOF) project, the effect of impurities on the processing of aluminum alloys was systematically investigated. The work was carried out as a collaborative effort between the Pennsylvania State University and Oak Ridge National Laboratory. Industrial support was provided by ALCOA and ThermoCalc, Inc. The achievements described below were made. A method that combines first-principles calculation and calculation of phase diagrams (CALPHAD) was used to develop the multicomponent database Al-Ca-K-Li-Mg-Na. This method was extensively used in this project for the development of a thermodynamic database. The first-principles approach provided some thermodynamic property data that are not available in the open literature. These calculated results were used in the thermodynamic modeling as experimental data. Some of the thermodynamic property data are difficult, if not impossible, to measure. The method developed and used in this project allows the estimation of these data for thermodynamic database development. The multicomponent database Al-Ca-K-Li-Mg-Na was developed. Elements such as Ca, Li, Na, and K are impurities that strongly affect the formability and corrosion behavior of aluminum alloys. However, these impurity elements are not included in the commercial aluminum alloy database. The process of thermodynamic modeling began from Al-Na, Ca-Li, Li-Na, K-Na, and Li-K sub-binary systems. Then ternary and higher systems were extrapolated because of the lack of experimental information. Databases for five binary alloy systems and two ternary systems were developed. Along with other existing binary and ternary databases, the full database of the multicomponent Al-Ca-K-Li-Mg-Na system was completed in this project. The methodology in integrating with commercial or other aluminum alloy databases can be developed. The mechanism of sodium-induced high-temperature embrittlement (HTE) of Al-Mg is now understood. Using the thermodynamic

  12. Fly Ash and Mercury Oxidation/Chlorination Reactions

    SciTech Connect (OSTI)

    Sukh Sidhu; Patanjali Varanasi

    2008-12-31

    Mercury is a known pollutant that has detrimental effect on human health and environment. The anthropogenic emissions of mercury account for 10 to 30% of worldwide mercury emissions. There is a need to control/reduce anthropogenic mercury emissions. Many mercury control technologies are available but their effectiveness is dependent on the chemical form of mercury, because different chemical forms of mercury have different physical and chemical properties. Mercury leaves the boiler in its elemental form but goes through various transformations in the post-combustion zone. There is a need to understand how fly ash and flue gas composition affect speciation, partitioning, and reactions of mercury under the full range of post-combustion zone conditions. This knowledge can then be used to predict the chemical transformation of mercury (elemental, oxidized or particulate) in the post combustion zone and thus help with the control of mercury emissions from coal-burning power plants. To accomplish this goal present study was conducted using five coal fly ashes. These ashes were characterized and their catalytic activity was compared under selected reaction conditions in a fixed bed reactor. Based on the results from these fly ash experiments, three key components (carbon, iron oxide and calcium oxide) were chosen. These three components were then used to prepare model fly ashes. Silica/alumina was used as a base for these model fly ashes. One, two or three component model fly ashes were then prepared to investigate mercury transformation reactions. The third set of experiments was performed with CuO and CuCl2 catalysts to further understand the mercury oxidation process. Based on the results of these three studies the key components were predicted for different fly ash compositions under variety of flue gas conditions. A fixed bed reactor system was used to conduct this study. In all the experiments, the inlet concentration of Hg0(g) was maintained at 35 {micro}g/m3 using

  13. Ash reduction in clean coal spiral product circuits

    SciTech Connect (OSTI)

    Brodzik, P.

    2007-04-15

    The article describes the Derrick Corporation's Stack Sizer{trademark} technology for high capacity fine wet cleaning with long-lasting high open-area urethane screen panels. After field trials, a Stack Sizer fitted with a 100-micron urethane panel is currently processing approximately 40 stph of clean coal spiral product having about 20% ash at McCoy-Elkhorn's Bevin Branch coal preparation plant in Kentucky, USA. Product yield is about 32.5 short tons per hour with 10% ash. The material is then fed to screen bowl centrifuges for further processing. At Blue Diamond Coal's Leatherwood preparation plant similar Stacker Sizers are achieving the same results. 2 figs., 3 tabs., 2 photo.

  14. Effects of pulverized coal fly-ash addition as a wet-end filler in papermaking

    SciTech Connect (OSTI)

    Sinha, A.S.K.

    2008-09-15

    This experimental study is based on the innovative idea of using pulverized coal fly ash as a wet-end filler in papermaking. This is the first evaluation of the possible use of fly ash in the paper industry. Coal-based thermal power plants throughout the world are generating fly ash as a solid waste product. The constituents of fly ash can be used effectively in papermaking. Fly ash has a wide variation in particle size, which ranges from a few micrometers to one hundred micrometers. Fly ash acts as an inert material in acidic, neutral, and alkaline papermaking processes. Its physical properties such as bulk density (800-980 kg/m{sup 3}), porosity (45%-57%), and surface area (0.138-2.3076 m{sup 2}/g) make it suitable for use as a paper filler. Fly ash obtained from thermal power plants using pulverized coal was fractionated by a vibratory-sieve stack. The fine fraction with a particle size below 38 micrometers was used to study its effect on the important mechanical-strength and optical properties of paper. The effects of fly-ash addition on these properties were compared with those of kaolin clay. Paper opacity was found to be much higher with fly ash as a filler, whereas brightness decreased as the filler percentage increased Mechanical strength properties of the paper samples with fly ash as filler were superior to those with kaolin clay.

  15. Construction of an embankment with a fly and bottom ash mixture: field performance study

    SciTech Connect (OSTI)

    Yoon, S.; Balunaini, U.; Yildirim, I.Z.; Prezzi, M.; Siddiki, N.Z.

    2009-06-15

    Fly ash and bottom ash are coal combustion by-products (CCBPs) that are generated in large quantities throughout the world. It is often economical to dispose ash as mixtures rather than separately; that notwithstanding, only a few studies have been performed to investigate the behavior of fly and bottom ash mixtures, particularly those with high contents of fly ash. Also, there is very limited data available in the literature on the field performance of structures constructed using ash mixtures. This paper describes the construction and the instrumentation of a demonstration embankment built with an ash mixture (60:40 by weight of fly ash:bottom ash) on State Road 641, Terre Haute, Ind. Monitoring of the demonstration embankment was conducted for a period of 1 year from the start of construction of the embankment. The settlement of the embankment stabilized approximately 5 months after the end of its construction. According to horizontal inclinometer readings, the differential settlement at the top of the embankment is about 5 mm. Results from field quality control tests performed during construction of the demonstration embankment and monitoring data from vertical and horizontal inclinometers and settlement plates indicate that the ash mixture investigated can be considered an acceptable embankment construction material.

  16. Differences in gasification behaviors and related properties between entrained gasifier fly ash and coal char

    SciTech Connect (OSTI)

    Jing Gu; Shiyong Wu; Youqing Wu; Ye Li; Jinsheng Gao

    2008-11-15

    In the study, two fly ash samples from Texaco gasifiers were compared to coal char and the physical and chemical properties and reactivity of samples were investigated by scanning electron microscopy (SEM), SEM-energy-dispersive spectrometry (EDS), X-ray diffraction (XRD), N{sub 2} and CO{sub 2} adsorption method, and isothermal thermogravimetric analysis. The main results were obtained. The carbon content of gasified fly ashes exhibited 31-37%, which was less than the carbon content of 58-59% in the feed coal. The fly ashes exhibited higher Brunauer-Emmett-Teller (BET) surface area, richer meso- and micropores, more disordered carbon crystalline structure, and better CO{sub 2} gasification reactivity than coal char. Ashes in fly ashes occurred to agglomerate into larger spherical grains, while those in coal char do not agglomerate. The minerals in fly ashes, especial alkali and alkaline-earth metals, had a catalytic effect on gasification reactivity of fly ash carbon. In the low-temperature range, the gasification process of fly ashes is mainly in chemical control, while in the high-temperature range, it is mainly in gas diffusion control, which was similar to coal char. In addition, the carbon in fly ashes was partially gasified and activated by water vapor and exhibited higher BET surface area and better gasification activity. Consequently, the fact that these carbons in fly ashes from entrained flow gasifiers are reclaimed and reused will be considered to be feasible. 15 refs., 7 figs., 5 tabs.

  17. Idaho Nuclear Technology and Engineering Center (INTEC) (formerly ICPP) ash reutilization study

    SciTech Connect (OSTI)

    Langenwalter, T.; Pettet, M.; Ochoa, R.; Jensen, S.

    1998-05-01

    Since 1984, the coal-fired plant at the Idaho Nuclear Technology and Engineering Center (INTEC, formerly Idaho Chemical Processing Plant) has been generating fly ash at a rate of approximately 1,000 tons per year. This ash is hydrated and placed in an ash bury pit near the coal-fired plant. The existing ash bury pit will be full in less than 1 year at its present rate of use. A conceptual design to build a new ash bury pit was completed, and the new pit is estimated to cost $1.7 million. This report evaluates ash reutilization alternatives that propose to eliminate this waste stream and save the $1.7 million required to build a new pit. The alternatives include using ash for landfill day cover, concrete admixture, flowable fill, soil stabilization, waste remediation, and carbon recovery technology. Both physical and chemical testing, under the guidance of the American Society for Testing and Materials, have been performed on ash from the existing pit and from different steps within the facility`s processes. The test results have been evaluated, compared to commercial ash, and are discussed as they relate to reutilization alternatives. This study recommends that the ash be used in flowable fill concrete for Deactivation and Demolition work at the Idaho National Engineering and Environmental Laboratory.

  18. Utilization of ash from municipal solid waste combustion. Final report, Phase I

    SciTech Connect (OSTI)

    Jones, C.M.; Hartman, R.M.; Kort, D.; Rapues, N.

    1994-09-01

    This ash study investigates several aspects of Municipal Waste Combustion (MWC) ash utilization to develop an alternative to the present disposal practice of landfilling in a lined monofill. Ash was investigated as a daily or final cover for municipal waste in the landfill to prevent erosion and as a road construction aggregate. Samples of eight mixtures of ash and other materials, and one sample of soil were analyzed for chemical constituents. Biological tests on these mixters were conducted, along with erosion tests and sieve analyses. A chemical analysis of each sieve size was conducted. Geotechnical properties of the most promising materials were made. Findings to this point include: all ash samples take have passed the EPA TCLP testing; chemical analysis of bottom and combined ash samples indicate less than expected variability; selected ash mixtures exhibited very low coefficients of hydraulic conductivity; all but one of the ash mixtures exhibited greater erosion resistance than the currently used landfill cover material; MWC combined analysis indicates this is a viable alternative for landfill cover; MWC ash size reactions and chemical analysis show bottom and combined ash to be a viable alternative for road construction.

  19. Leaching characteristics of arsenic and selenium from coal fly ash: role of calcium

    SciTech Connect (OSTI)

    Tian Wang; Jianmin Wang; Yulin Tang; Honglan Shi; Ken Ladwig

    2009-05-15

    Understanding the leaching behavior of arsenic (As) and selenium (Se) in coal fly ash is important in evaluating the potential environmental impact of coal fly ash. Batch experiments were employed to systematically investigate the leaching behavior of As and Se in two major types of coal fly ashes, bituminous coal ash and sub-bituminous coal ash, and to determine the underlying processes that control As and Se leaching. The effects of pH, solid/liquid (S/L) ratio, calcium addition, and leaching time on the release of As and Se were studied. Overall, bituminous coal ash leached significantly more As and Se than sub-bituminous coal ash, and Se was more readily leachable, in both absolute concentration and relative fraction, than As for both types of fly ashes. Adsorption/desorption played a major role on As and Se leaching from bituminous coal ashes. However, calcium precipitation played the most important role in reducing As and Se leaching from sub-bituminous coal ashes in the entire experimental pH range. The leaching of As and Se from bituminous coal ashes generally increased with increases in the S/L ratio and leaching time. However, for sub-bituminous coal ashes, the leaching of As was not detected under most experimental conditions, while the leaching of Se increased with increases in the S/L ratio and leaching time. As{sup V} and Se{sup IV} were found to be the major species in all ash leachates in this study. 46 refs., 7 figs., 1 tab.

  20. GLYCOLIC ACID PHYSICAL PROPERTIES, IMPURITIES, AND RADIATION EFFECTS ASSESSMENT

    SciTech Connect (OSTI)

    Lambert, D.; Pickenheim, B.; Hay, M.

    2011-06-20

    The Defense Waste Processing Facility (DWPF) is pursuing alternative reductants/flowsheets to increase attainment to meet closure commitment dates. In fiscal year 2009, SRNL evaluated several options and recommended the further assessment of the nitric/formic/glycolic acid flowsheet. SRNL is currently performing testing with this flowsheet to support the DWPF down-select of alternate reductants. As part of the evaluation, SRNL was requested to determine the physical properties of formic and glycolic acid blends. Blends of formic acid in glycolic acid were prepared and their physical properties tested. Increasing amounts of glycolic acid led to increases in blend density, viscosity and surface tension as compared to the 90 wt% formic acid that is currently used at DWPF. These increases are small, however, and are not expected to present any difficulties in terms of processing. The effect of sulfur impurities in technical grade glycolic acid was studied for its impact on DWPF glass quality. While the glycolic acid specification allows for more sulfate than the current formic acid specification, the ultimate impact is expected to be on the order of 0.03 wt% sulfur in glass. Note that lower sulfur content glycolic acid could likely be procured at some increased cost if deemed necessary. A paper study on the effects of radiation on glycolic acid was performed. The analysis indicates that substitution of glycolic acid for formic acid would not increase the radiolytic production rate of H{sub 2} and cause an adverse effect in the SRAT or SME process. It has been cited that glycolic acid solutions that are depleted of O{sub 2} when subjected to large radiation doses produced considerable quantities of a non-diffusive polymeric material. Considering a constant air purge is maintained in the SRAT and the solution is continuously mixed, oxygen depletion seems unlikely, however, if this polymer is formed in the SRAT solution, the rheology of the solution may be affected and

  1. GLYCOLIC ACID PHYSICAL PROPERTIES, IMPURITIES, AND RADIATION EFFECTS ASSESSMENT

    SciTech Connect (OSTI)

    Pickenheim, B.; Bibler, N.

    2010-06-08

    The DWPF is pursuing alternative reductants/flowsheets to increase attainment to meet closure commitment dates. In fiscal year 2009, SRNL evaluated several options and recommended the further assessment of the nitric/formic/glycolic acid flowsheet. SRNL is currently performing testing with this flowsheet to support the DWPF down-select of alternate reductants. As part of the evaluation, SRNL was requested to determine the physical properties of formic and glycolic acid blends. Blends of formic acid in glycolic acid were prepared and their physical properties tested. Increasing amounts of glycolic acid led to increases in blend density, viscosity and surface tension as compared to the 90 wt% formic acid that is currently used at DWPF. These increases are small, however, and are not expected to present any difficulties in terms of processing. The effect of sulfur impurities in technical grade glycolic acid was studied for its impact on DWPF glass quality. While the glycolic acid specification allows for more sulfate than the current formic acid specification, the ultimate impact is expected to be on the order of 0.03 wt% sulfur in glass. Note that lower sulfur content glycolic acid could likely be procured at some increased cost if deemed necessary. A paper study on the effects of radiation on glycolic acid was performed. The analysis indicates that substitution of glycolic acid for formic acid would not increase the radiolytic production rate of H{sub 2} and cause an adverse effect in the SRAT or SME process. It has been cited that glycolic acid solutions that are depleted of O{sub 2} when subjected to large radiation doses produced considerable quantities of a non-diffusive polymeric material. Considering a constant air purge is maintained in the SRAT and the solution is continuously mixed, oxygen depletion seems unlikely, however, if this polymer is formed in the SRAT solution, the rheology of the solution may be affected and pumping of the solution may be

  2. Oil shale ash-layer thickness and char combustion kinetics

    SciTech Connect (OSTI)

    Aldis, D.F.; Singleton, M.F.; Watkins, B.E.; Thorsness, C.B.; Cena, R.J.

    1992-04-15

    A Hot-Recycled-Solids (HRS) oil shale retort is being studied at Lawrence Livermore National Laboratory. In the HRS process, raw shale is heated by mixing it with burnt retorted shale. Retorted shale is oil shale which has been heated in an oxygen deficient atmosphere to pyrolyze organic carbon, as kerogen into oil, gas, and a nonvolatile carbon rich residue, char. In the HRS retort process, the char in the spent shale is subsequently exposed to an oxygen environment. Some of the char, starting on the outer surface of the shale particle, is burned, liberating heat. In the HRS retort, the endothermic pyrolysis step is supported by heat from the exothermic char combustion step. The rate of char combustion is controlled by three resistances; the resistance of oxygen mass transfer through the gas film surrounding the solid particle, resistance to mass transfer through a ash layer which forms on the outside of the solid particles as the char is oxidized and the resistance due to the intrinsic chemical reaction rate of char and oxygen. In order to estimate the rate of combustion of the char in a typical oil shale particle, each of these resistances must be accurately estimated. We begin by modeling the influence of ash layer thickness on the over all combustion rate of oil shale char. We then present our experimental measurements of the ash layer thickness of oil shale which has been processed in the HRS retort.

  3. Effects of Sediment Containing Coal Ash from the Kingston Ash Release on Embryo-Larval Development in the Fathead Minnow, Pimephales promelas (Rafinesque, 1820)

    SciTech Connect (OSTI)

    Greeley Jr, Mark Stephen; Elmore, Logan R; McCracken, Kitty; Sherrard, Rick

    2014-01-01

    The largest environmental release of coal ash in U.S. history occurred in December 2008 with the failure of a retention structure at the Tennessee Valley Authority (TVA) Kingston Fossil Plant in East Tennessee. A byproduct of coal-burning power plants, coal ash is enriched in metals and metalloids such as selenium and arsenic with known toxicity to fish including embryonic and larval stages. The effects of contact exposure to sediments containing up to 78 % coal ash from the Kingston spill on the early development of fish embryos and larvae were examined in 7-day laboratory tests with the fathead minnow (Pimephales promelas). No significant effects were observed on hatching success, incidences of gross developmental abnormalities, or embryo-larval survival. Results suggest that direct exposures to sediment containing residual coal ash from the Kingston ash release may not present significant risks to fish eggs and larvae in waterways affected by the spill.

  4. A Spectroscopic Study of Impurity Behavior in Neutral-beam and Ohmically Heated TFTR Discharges

    DOE R&D Accomplishments [OSTI]

    Stratton, B. C.; Ramsey, A. T.; Boody, F. P.; Bush, C. E.; Fonck, R. J.; Groenbner, R. J.; Hulse, R. A.; Richards, R. K.; Schivell, J.

    1987-02-01

    Quantitative spectroscopic measurements of Z{sub eff}, impurity densities, and radiated power losses have been made for ohmic- and neutral-beam-heated TFTR discharges at a plasma current of 2.2 MA and toroidal field of 4.7 T. Variations in these quantities with line-average plasma density (anti n{sub e}) and beam power up to 5.6 MW are presented for discharges on a graphite movable limiter. A detailed discussion of the use of an impurity transport model to infer absolute impurity densities and radiative losses from line intensity and visible continuum measurements is given. These discharges were dominated by low-Z impurities with carbon having a considerably higher density than oxygen, except in high-anti n{sub e} ohmic discharges, where the densities of carbon and oxygen were comparable. Metallic impurity concentrations and radiative losses were small, resulting in hollow radiated power profiles and fractions of the input power radiated being 30 to 50% for ohmic heating and 30% or less with beam heating. Spectroscopic estimates of the radiated power were in good agreement with bolometrically measured values. Due to an increase in the carbon density, Z{sub eff} rose from 2.0 to 2.8 as the beam power increased from 0 to 5.6 MW, pointing to a potentially serious dilution of the neutron-producing plasma ions as the beam power increased. Both the low-Z and metallic impurity concentrations were approximately constant with minor radius, indicating no central impurity accumulation in these discharges.

  5. Relationship between textural properties, fly ash carbons, and Hg capture in fly ashes derived from the combustion of anthracitic pulverized feed blends

    SciTech Connect (OSTI)

    Isabel Surez-Ruiz; Jose B. Parra

    2007-08-15

    In this work, the textural properties of a series of whole anthracitic-derived fly ashes sampled in eight hoppers from the electrostatic precipitators and their sized fractions (from {gt}150 to {lt}25 {mu}m) are investigated. Data from N{sub 2} adsorption isotherms at 77 K, helium density, and mercury porosimetry have contributed to establish a relationship between the Brunauer-Emmett-Teller (BET) surface areas, VTOT, porosity, carbon content (the type of fly ash carbons), and Hg retention in these fly ashes. The unburned carbons in these ashes are macroporous materials, and they are different from the carbons in fly ashes from classes C and F (the latter derived from the combustion of bituminous coals) and show different textural properties. These ashes represent the end member of the fly ash classes C and F with respect to certain textural properties. Although the BET surface area and VTOT values for the studied samples are the lowest reported, they increase with the increase in carbon content, anisotropic carbon content, and particle size of the ashes. Thus, a positive relationship between all these parameters and Hg capture by the coarser ash fractions was found. The finest fraction of carbons ({lt}25 {mu}m) represented an exception. Although it makes a significant contribution to the total carbon of the whole fly ashes and shows relatively higher surface areas and VTOT values, its Hg concentration was found to be the lowest. This suggests that the type of unburned carbons in the finest fraction and/or other adsorption mechanisms may play a role in Hg concentration. Because the textural properties of anisotropic carbons depend on their subtype and on their origin, the need for its differentiation has been evidenced. 54 refs., 8 figs., 3 tabs.

  6. Generalized arc consistency for global cardinality constraint

    SciTech Connect (OSTI)

    Regin, J.C.

    1996-12-31

    A global cardinality constraint (gcc) is specified in terms of a set of variables X = (x{sub 1},..., x{sub p}) which take their values in a subset of V = (v{sub 1},...,v{sub d}). It constrains the number of times a value v{sub i} {epsilon} V is assigned to a variable in X to be in an interval [l{sub i}, c{sub i}]. Cardinality constraints have proved very useful in many real-life problems, such as scheduling, timetabling, or resource allocation. A gcc is more general than a constraint of difference, which requires each interval to be. In this paper, we present an efficient way of implementing generalized arc consistency for a gcc. The algorithm we propose is based on a new theorem of flow theory. Its space complexity is O({vert_bar}X{vert_bar} {times} {vert_bar}V{vert_bar}) and its time complexity is O({vert_bar}X{vert_bar}{sup 2} {times} {vert_bar}V{vert_bar}). We also show how this algorithm can efficiently be combined with other filtering techniques.

  7. Integrated production/use of ultra low-ash coal, premium liquids and clean char

    SciTech Connect (OSTI)

    Kruse, C.W.

    1991-01-01

    This integrated, multi-product approach for utilizing Illinois coal starts with the production of ultra low-ash coal and then converts it to high-vale, coal-derived, products. The ultra low-ash coal is produced by solubilizing coal in a phenolic solvent under ChemCoal{trademark} process conditions, separating the coal solution from insoluble ash, and then precipitating the clean coal by dilution of the solvent with methanol. Two major products, liquids and low-ash char, are then produced by mild gasification of the low-ash coal. The low ash-char is further upgraded to activated char, and/or an oxidized activated char which has catalytic properties. Characterization of products at each stage is part of this project.

  8. Comparative performance of geopolymers made with metakaolin and fly ash after exposure to elevated temperatures

    SciTech Connect (OSTI)

    Kong, Daniel L.Y.; Sanjayan, Jay G. Sagoe-Crentsil, Kwesi

    2007-12-15

    This paper presents the results of a study on the effect of elevated temperatures on geopolymers manufactured using metakaolin and fly ash of various mixture proportions. Both types of geopolymers (metakaolin and fly ash) were synthesized with sodium silicate and potassium hydroxide solutions. The strength of the fly ash-based geopolymer increased after exposure to elevated temperatures (800 deg. C). However, the strength of the corresponding metakaolin-based geopolymer decreased after similar exposure. Both types of geopolymers were subjected to thermogravimetric, scanning electron microscopy and mercury intrusion porosimetry tests. The paper concludes that the fly ash-based geopolymers have large numbers of small pores which facilitate the escape of moisture when heated, thus causing minimal damage to the geopolymer matrix. On the other hand, metakaolin geopolymers do not possess such pore distribution structures. The strength increase in fly ash geopolymers is also partly attributed to the sintering reactions of un-reacted fly ash particles.

  9. Impurities in a non-axisymmetric plasma. Transport and effect on bootstrap current

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

    Mollén, A.; Landreman, M.; Smith, H. M.; Braun, S.; Helander, P.

    2015-11-20

    Impurities cause radiation losses and plasma dilution, and in stellarator plasmas the neoclassical ambipolar radial electric field is often unfavorable for avoiding strong impurity peaking. In this work we use a new continuum drift-kinetic solver, the SFINCS code (the Stellarator Fokker-Planck Iterative Neoclassical Conservative Solver) [M. Landreman et al., Phys. Plasmas 21 (2014) 042503] which employs the full linearized Fokker-Planck-Landau operator, to calculate neoclassical impurity transport coefficients for a Wendelstein 7-X (W7-X) magnetic configuration. We compare SFINCS calculations with theoretical asymptotes in the high collisionality limit. We observe and explain a 1/nu-scaling of the inter-species radial transport coefficient at lowmore » collisionality, arising due to the field term in the inter-species collision operator, and which is not found with simplified collision models even when momentum correction is applied. However, this type of scaling disappears if a radial electric field is present. We use SFINCS to analyze how the impurity content affects the neoclassical impurity dynamics and the bootstrap current. We show that a change in plasma effective charge Zeff of order unity can affect the bootstrap current enough to cause a deviation in the divertor strike point locations.« less

  10. Density functional theory calculations of stability and diffusion mechanisms of impurity atoms in Ge crystals

    SciTech Connect (OSTI)

    Maeta, Takahiro; Sueoka, Koji

    2014-08-21

    Ge-based substrates are being developed for applications in advanced nano-electronic devices because of their higher intrinsic carrier mobility than Si. The stability and diffusion mechanism of impurity atoms in Ge are not well known in contrast to those of Si. Systematic studies of the stable sites of 2nd to 6th row element impurity atoms in Ge crystal were undertaken with density functional theory (DFT) and compared with those in Si crystal. It was found that most of the impurity atoms in Ge were stable at substitutional sites, while transition metals in Si were stable at interstitial sites and the other impurity atoms in Si were stable at substitutional sites. Furthermore, DFT calculations were carried out to clarify the mechanism responsible for the diffusion of impurity atoms in Ge crystals. The diffusion mechanism for 3d transition metals in Ge was found to be an interstitial-substitutional diffusion mechanism, while in Si this was an interstitial diffusion mechanism. The diffusion barriers in the proposed diffusion mechanisms in Ge and Si were quantitatively verified by comparing them to the experimental values in the literature.

  11. Impurities in a non-axisymmetric plasma. Transport and effect on bootstrap current

    SciTech Connect (OSTI)

    Mollén, A.; Landreman, M.; Smith, H. M.; Braun, S.; Helander, P.

    2015-11-20

    Impurities cause radiation losses and plasma dilution, and in stellarator plasmas the neoclassical ambipolar radial electric field is often unfavorable for avoiding strong impurity peaking. In this work we use a new continuum drift-kinetic solver, the SFINCS code (the Stellarator Fokker-Planck Iterative Neoclassical Conservative Solver) [M. Landreman et al., Phys. Plasmas 21 (2014) 042503] which employs the full linearized Fokker-Planck-Landau operator, to calculate neoclassical impurity transport coefficients for a Wendelstein 7-X (W7-X) magnetic configuration. We compare SFINCS calculations with theoretical asymptotes in the high collisionality limit. We observe and explain a 1/nu-scaling of the inter-species radial transport coefficient at low collisionality, arising due to the field term in the inter-species collision operator, and which is not found with simplified collision models even when momentum correction is applied. However, this type of scaling disappears if a radial electric field is present. We use SFINCS to analyze how the impurity content affects the neoclassical impurity dynamics and the bootstrap current. We show that a change in plasma effective charge Zeff of order unity can affect the bootstrap current enough to cause a deviation in the divertor strike point locations.

  12. Ash reduction strategies in corn stover facilitated by anatomical and size fractionation

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

    Lacey, Jeffrey A.; Emerson, Rachel M.; Thompson, David N.; Westover, Tyler L.

    2016-04-22

    There is growing interest internationally to produce fuels from renewable biomass resources. Inorganic components of biomass feedstocks, referred to collectively as ash, damage equipment and decrease yields in thermal conversion processes, and decrease feedstock value for biochemical conversion processes. Decreasing the ash content of feedstocks improves conversion efficiency and lowers process costs. Because physiological ash is unevenly distributed in the plant, mechanical processes can be used to separate fractions of the plant based on ash content. This study focuses on the ash separation that can be achieved by separating corn stover by particle size and anatomical fraction. Baled corn stovermore » was hand-separated into anatomical fractions, ground to <19.1 mm, and size separated using six sieves ranging from 9.5 to 0.150 mm. Size fractions were analyzed for total ash content and ash composition. Particle size distributions observed for the anatomical fractions varied considerably. Cob particles were primarily 2.0 mm or greater, while most of the sheath and husk particles were 2.0 mm and smaller. Particles of leaves greater than 0.6 mm contained the greatest amount of total ash, ranging from approximately 8 to 13% dry weight of the total original material, while the fractions with particles smaller than 0.6 mm contained less than 2% of the total ash of the original material. As a result, based on the overall ash content and the elemental ash, specific anatomical and size fractions can be separated to optimize the feedstocks being delivered to biofuels conversion processes and minimize the need for more expensive ash reduction treatments.« less

  13. 2.8-Ma Ash-Flow Caldera At Chegem River In The Northern Caucasus...

    Open Energy Info (EERE)

    .8-Ma Ash-Flow Caldera At Chegem River In The Northern Caucasus Mountains (Russia), Contemporaneous Granites, And Associated Ore Deposits Jump to: navigation, search OpenEI...

  14. Experimental and numerical analysis of metal leaching from fly ash-amended highway bases

    SciTech Connect (OSTI)

    Cetin, Bora; Aydilek, Ahmet H.; Li, Lin

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer This study is the evaluation of leaching potential of fly ash-lime mixed soils. Black-Right-Pointing-Pointer This objective is met with experimental and numerical analysis. Black-Right-Pointing-Pointer Zn leaching decreases with increase in fly ash content while Ba, B, Cu increases. Black-Right-Pointing-Pointer Decrease in lime content promoted leaching of Ba, B and Cu while Zn increases. Black-Right-Pointing-Pointer Numerical analysis predicted lower field metal concentrations. - Abstract: A study was conducted to evaluate the leaching potential of unpaved road materials (URM) mixed with lime activated high carbon fly ashes and to evaluate groundwater impacts of barium, boron, copper, and zinc leaching. This objective was met by a combination of batch water leach tests, column leach tests, and computer modeling. The laboratory tests were conducted on soil alone, fly ash alone, and URM-fly ash-lime kiln dust mixtures. The results indicated that an increase in fly ash and lime content has significant effects on leaching behavior of heavy metals from URM-fly ash mixture. An increase in fly ash content and a decrease in lime content promoted leaching of Ba, B and Cu whereas Zn leaching was primarily affected by the fly ash content. Numerically predicted field metal concentrations were significantly lower than the peak metal concentrations obtained in laboratory column leach tests, and field concentrations decreased with time and distance due to dispersion in soil vadose zone.

  15. Recovery Act Workers Accomplish Cleanup of Second Cold War Coal Ash Basin

    Broader source: Energy.gov [DOE]

    American Recovery and Reinvestment Act workers recently cleaned up a second basin containing coal ash residues from Cold War operations at the Savannah River Site (SRS).

  16. MARKET ASSESSMENT AND TECHNICAL FEASIBILITY STUDY OF PRESSURIZED FLUIDIZED BED COMBUSTION ASH USE

    SciTech Connect (OSTI)

    A.E. Bland; T.H. Brown

    1997-04-01

    Western Research Institute, in conjunction with the Electric Power Research Institute, Foster Wheeler International, Inc. and the US Department of Energy, has undertaken a research and demonstration program designed to examine the market potential and the technical feasibility of ash use options for PFBC ashes. Ashes from the Foster Wheeler Energia Oy pilot-scale circulating PFBC tests in Karhula, Finland, combusting (1) low-sulfur subbituminous and (2) high-sulfur bituminous coal, and ash from the AEP's high-sulfur bituminous coal-fired bubbling PFBC in Brilliant, Ohio, were evaluated in laboratory and pilot-scale ash use testing at WR1. The technical feasibility study examined the use of PFBC ash in construction-related applications, including its use as a cementing material in concrete and use in cement manufacturing, fill and embankment materials, soil stabilization agent, and use in synthetic aggregate production. Testing was also conducted to determine the technical feasibility of PFBC ash as a soil amendment for acidic and sodic problem soils and spoils encountered in agricultural and reclamation applications. The results of the technical feasibility testing indicated the following conclusions. PFBC ash does not meet the chemical requirements as a pozzolan for cement replacement. However, it does appear that potential may exist for its use in cement production as a pozzolan and/or as a set retardant. PFBC ash shows relatively high strength development, low expansion, and low permeability properties that make its use in fills and embankments promising. Testing has also indicated that PFBC ash, when mixed with low amounts of lime, develops high strengths, suitable for soil stabilization applications and synthetic aggregate production. Synthetic aggregate produced from PFBC ash is capable of meeting ASTM/AASHTO specifications for many construction applications. The residual calcium carbonate and calcium sulfate in the PFE3C ash has been shown to be of value in

  17. The Development of a Small Engine Based Accelerated Ash Loading Protocol |

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

    Department of Energy Accelerated Ash Loading Protocol The Development of a Small Engine Based Accelerated Ash Loading Protocol Presentation given at DEER 2006, August 20-24, 2006, Detroit, Michigan. Sponsored by the U.S. DOE's EERE FreedomCar and Fuel Partnership and 21st Century Truck Programs. 2006_deer_bunting.pdf (371.89 KB) More Documents & Publications The Development of a Small Engine Based Ash Loading Protocol Development of an Accelerated Ash-Loading Protocol for Diesel

  18. The Development of a Small Engine Based Ash Loading Protocol | Department

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

    of Energy Ash Loading Protocol The Development of a Small Engine Based Ash Loading Protocol When 5% lubrication oil is added to diesel fuel in a small engine test, ash increases linearly and at the back of a filter, the amount depending on the differences in substrate and wash-coat type. deer08_bunting.pdf (322.41 KB) More Documents & Publications Development of an Accelerated Ash-Loading Protocol for Diesel Particulate Filters Requirements-Driven Diesel Catalyzed Particulate Trap Design

  19. Savannah River Site Takes on Another Environmental Cleanup Challenge: Coal-Fired Ash

    Broader source: Energy.gov [DOE]

    AIKEN, S.C. – Workers have begun excavating a thick layer of coal ash covering approximately 100 acres of the Savannah River Site (SRS).

  20. Statics and dynamics of atomic dark-bright solitons in the presence of impurities

    SciTech Connect (OSTI)

    Achilleos, V.; Frantzeskakis, D. J.; Kevrekidis, P. G.; Rothos, V. M.

    2011-11-15

    Adopting a mean-field description for a two-component atomic Bose-Einstein condensate, we study the statics and dynamics of dark-bright solitons in the presence of localized impurities. We use adiabatic perturbation theory to derive an equation of motion for the dark-bright soliton center. We show that, counterintuitively, an attractive (repulsive) delta-like impurity, acting solely on the bright-soliton component, induces an effective localized barrier (well) in the effective potential felt by the soliton; this way, dark-bright solitons are reflected from (transmitted through) attractive (repulsive) impurities. Our analytical results for the small-amplitude oscillations of solitons are found to be in good agreement with results obtained via a Bogoliubov-de Gennes analysis and direct numerical simulations.

  1. Evaluation of helium impurity impacts on Spent Nuclear Fuel project processes (OCRWM)

    SciTech Connect (OSTI)

    SHERRELL, D.L.

    1999-09-21

    This document identifies the types and quantities of impurities that may be present within helium that is introduced into multi-canister overpacks (MCO)s by various SNF Project facilities, including, but not limited to the Cold Vacuum Drying (CVD) Facility (CVDF). It then evaluates possible impacts of worst case impurity inventories on MCO drying, transportation, and storage processes. Based on the evaluation results, this document: (1) concludes that the SNF Project helium procurement specification can be a factor-of-ten less restrictive than a typical vendor's standard offering (99.96% pure versus the vendor's 99.997% pure standard offering); (2) concludes that the CVDF's current 99.5% purity requirement is adequate to control the quality of the helium that is delivered to the MCO by the plant's helium distribution system; and (3) recommends specific impurity limits for both of the above cases.

  2. Role of Trapping Impurities on He Desorption and Clustering in Irradiated a-Fe

    SciTech Connect (OSTI)

    Ortiz, Christophe J.; Caturla, Maria Jose; Fu, Chu Chun; Willaime, Francois

    2008-07-01

    It is well-known that impurities affect the migration of intrinsic point defects in metals. For instance, carbon is a common impurity in Fe that significantly retards diffusion of vacancies. Under fusion irradiation conditions, high levels of He are produced by transmutation reactions. This element strongly interacts with vacancies produced during irradiation and agglomerate into stable He-vacancy clusters that can deteriorate the mechanical properties of the material. A physically-based model accounting for the interactions between He, point defects (interstitials and vacancies) and trapping impurities is therefore necessary to understand and predict damage evolution in Fe. We have used a multi-scale approach to predict the evolution of He in the presence of impurities in irradiated Fe. Density Functional Theory (DFT) calculations were performed to investigate the migration mechanisms and to determine the activation energies of the different atomistic processes. The influence of impurities - such as carbon - on the binding energies of small He-vacancy clusters was also studied. Using the information obtained by DFT a physically-based model was developed and implemented in a kinetic Monte Carlo (kMC) code to follow the evolution of He in Fe. In addition, a model based on the rate theory (RT) was developed in order to achieve larger simulation times and volumes. Results obtained with this model, which is based on a mean field approximation are compared to those obtained with kMC. Using this multi-scale approach, the simulation results are used to interpret the different stages of thermal He desorption experiments and to determine the predominant migration mechanism. The influence of impurities which affect the diffusion of point defects or modify the binding energies of He-vacancy type clusters is also studied. (authors)

  3. A Functional Impurity for Li-O2 Battery Cathode - Joint Center for Energy

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

    Storage Research December 2, 2015, Research Highlights A Functional Impurity for Li-O2 Battery Cathode Galvanostatic discharge curves of activated carbon cathodes (a) with different K-impurity levels (i.e. KAC4 to KAC16) at 0.1 mA/cm2 and the corresponding SEM images (b to e) of the discharged cathode. Scientific Achievement Demonstrated that alkali metal can be used as a catalyst Li-O2 cell cathode design and opens the possibility of future optimization of functional K-doping in carbon

  4. Coal-ash Corrosion of Alloys for Combustion Power Plants

    SciTech Connect (OSTI)

    Natesan, K.; Purohit, A.; Rink, D.L.

    2003-04-22

    A program on coal-ash corrosion is being conducted at Argonne National Laboratory to evaluate the performance of several structural alloys in the presence of mixtures of synthetic coal ash, alkali sulfates, and alkali chlorides. Candidate alloys are also exposed in a small-scale coal-fired combustor at the National Energy Technology Laboratory in Pittsburgh. Experiments in the present program, which addresses the effects of deposit chemistry, temperature, and alloy chemistry on the corrosion response of alloys, were conducted at temperatures in the range of 575-800 C for time periods up to {approx}1850 h. Fe-base alloys selected for the study included HR3C, 310TaN, HR120, SAVE 25, NF709, modified 800, 347HFG, and HCM12A. In addition, 800H clad with Alloy 671 was included in several of the exposures. Ni-base alloys selected for the study included 600, 601, 617, 690, 625, 602CA, 214, 230, 45TM, HR 160, and 693. Data were obtained on weight change, scale thickness, internal penetration, microstructural characteristics of corrosion products, mechanical integrity of the scales, and cracking of scales. Results showed that the relationship of corrosion rates to temperature followed a bell-shaped curve for Fe-base alloys, with peak rates at {approx}725 C, but the rate itself was dependent on the alloy chemistry. Several Fe-base alloys showed acceptable rates in the sulfate-containing coal-ash environment; but NaCl in the deposit led to catastrophic corrosion at 650 and 800 C. Ni-base alloys generally exhibited less corrosion than the Fe-base alloys under similar exposure conditions; however, they were susceptible to localized corrosion in the form of pits.

  5. Growth and elemental accumulation by canola on soil amended with coal fly ash

    SciTech Connect (OSTI)

    Yunusa, I.A.M.; Manoharan, V.; DeSilva, D.L.; Eamus, D.; Murray, B.R.; Nissanka, S.P.

    2008-05-15

    To explore the agronomic potential of an Australian coal fly ash, we conducted two glasshouse experiments in which we measured chlorophyll fluorescence, CO{sub 2} assimilation (A), transpiration, stomatal conductance, biomass accumulation, seed yield, and elemental uptake for canola (Brassica napus) grown on soil amended with an alkaline fly ash. In Experiment 1, application of up to 25 Mg/ha of fly ash increased A and plant weight early in the season before flowering and seed yield by up to 21%. However, at larger rates of ash application A, plant growth, chlorophyll concentration, and yield were all reduced. Increases in early vigor and seed yield were associated with enhanced uptake of phosphorus (P) by the plants treated with fly ash. Fly ash application did not influence accumulation of B, Cu, Mo, or Zn in the stems at any stage of plant growth or in the seed at harvest, except Mo concentration, which was elevated in the seed. Accumulation of these elements was mostly in the leaves, where concentrations of Cu and Mo increased with any amount of ash applied while that of B occurred only with ash applied at 625 Mg/ha. In Experiment 2, fly ash applied at 500 Mg/ha and mixed into the whole 30 cm soil core was detrimental to growth and yield of canola, compared with restricting mixing to 5 or 15 cm depth. In contrast, application of ash at 250 Mg/ha with increasing depth of mixing increased A and seed yield. We concluded that fly ash applied at not more than 25 Mg/ha and mixed into the top 10 to 15 cm of soil is sufficient to obtain yield benefits.

  6. Controlled Experiments on the Effects of Lubricant/Additive (Low-Ash, Ashless) Characteristics on DPF Degradation

    Broader source: Energy.gov [DOE]

    Effects of lubricant additive chemistries and exhaust conditions on ash properties affecting diesel particulate filter performance. Comparison of ash characteristics such as packing density and elemental composition in field and laboratory aged DPFs.

  7. Influence of combustion conditions and coal properties on physical properties of fly ash generated from pulverized coal combustion

    SciTech Connect (OSTI)

    Hiromi Shirai; Hirofumi Tsuji; Michitaka Ikeda; Toshinobu Kotsuji

    2009-07-15

    To develop combustion technology for upgrading the quality of fly ash, the influences of the coal properties, such as the size of pulverized coal particles and the two-stage combustion ratio during the combustion, on the fly ash properties were investigated using our test furnace. The particle size, density, specific surface area (obtained by the Blaine method), and shape of fly ash particles of seven types of coal were measured. It was confirmed that the size of pulverized coal particles affects the size of the ash particles. Regarding the coal properties, the fuel ratio affected the ash particle size distribution. The density and shape of the ash particles strongly depended on their ash size. Our results indicated that the shape of the ash particles and the concentration of unburned carbon affected the specific surface area. The influence of the two-stage combustion ratio was limited. 8 refs., 13 figs., 3 tabs.

  8. Determination of Total Solids and Ash in Algal Biomass: Laboratory Analytical Procedure (LAP)

    SciTech Connect (OSTI)

    Van Wychen, S.; Laurens, L. M. L.

    2013-12-01

    This procedure describes the methods used to determine the amount of moisture or total solids present in a freeze-dried algal biomass sample, as well as the ash content. A traditional convection oven drying procedure is covered for total solids content, and a dry oxidation method at 575?C is covered for ash content.

  9. California bearing ratio behavior of soil-stabilized class F fly ash systems

    SciTech Connect (OSTI)

    Leelavathamma, B.; Mini, K.M.; Pandian, N.S.

    2005-11-01

    Fly ash is a finely divided mineral residue resulting from the combustion of coal in power plants that occupies large extents of land and also causes environmental problems. Hence, concerted attempts are being made to effectively use fly ash in an environmentally friendly way instead of dumping. Several studies have been carried out for its bulk utilization, such as its addition to improve the California bearing ratio (CBR) of soil in roads and embankments. But a thorough mixing of fly ash with soil may not be possible in the field. Hence a study has been carried out on the CBR behavior of black cotton soil and Raichur fly ash (which is class F) in layers and compared with the same in mixes. The results show that the CBR values of soil-fly ash mixes are better than layers, as expected. To improve the strength of layers, cement is used as an additive to fly ash. The results show that black cotton soil can be improved with stabilized fly ash, solving its strength problem as well as the disposal problem of fly ash.

  10. Stabilization of Oklahoma expensive soils using lime and class C fly ash

    SciTech Connect (OSTI)

    Buhler, R.L.; Cerato, A.B.

    2007-01-15

    This study uses lime and class C fly ash, an industrial byproduct of electric power production produced from burning lignite and subbituminous coal, to study the plasticity reduction in highly expensive natural clays from Idabel, Oklahoma. This study is important, especially in Oklahoma, because most of the native soils are expansive and cause seasonal damage to roadways and structures. The addition of lime or fly ash helps to arrest the shrinkage and swelling behavior of soil. Four soil samples with the same AASHTO classification were used in this study to show shrinkage variability within a soil group with the addition of lime and class C fly ash. The plasticity reduction in this study was quantified using the linear shrinkage test. It was found that soils classified within the same AASHTO group had varying shrinkage characteristics. It was also found that both lime and fly ash reduced the lienar shrinkage, however, the addition of lime reduced the linear shrinkage to a greater degree than the same percentage of class C fly ash. Even though it takes much less lime than fly ash to reduce the plasticity of a highly expansive soil, it may be less expensive to utilize fly ash, which is a waste product of electric power production. Lime also has a lower unit weight than fly ash so weight percentage results may be misleading.

  11. INVESTIGATION OF FLY ASH AND ACTIVATED CARBON OBTAINED FROM PULVERIZED COAL BOILERS

    SciTech Connect (OSTI)

    Edward K. Levy; Christopher Kiely

    2004-11-01

    One of the techniques for Hg capture in coal-fired boilers involves injection of activated carbon (AC) into the boiler downstream of the air preheater. Hg is adsorbed onto the AC particles and fly ash, which are then both removed in an electrostatic precipitator or baghouse. This project addresses the issues of Hg on activated carbon and on fly ash from a materials re-use point of view. It also addresses the possible connection between SCR reactors, fly ash properties and Hg capture. The project is determining the feasibility of separating AC from fly ash in a fluidized bed and of regenerating the separated AC by heating the AC to elevated temperatures in a fluidized bed. The temperatures needed to drive off the Hg from the ash in a fluidized bed are also being determined. Finally, samples of fly ash from power plants with SCR reactors for NO{sub x} control, are being analyzed to determine the effect of SCR on the ash. These analyses will also determine the properties of ash which are important for Hg capture.

  12. Site-specific study on stabilization of acid-generating mine tailings using coal fly ash

    SciTech Connect (OSTI)

    Shang, J.Q.; Wang, H.L.; Kovac, V.; Fyfe, J.

    2006-03-15

    A site-specific study on stabilizing acid-generating mine tailings from Sudbury Mine using a coal fly ash from Nanticoke Generating Station is presented in this paper. The objective of the study is to evaluate the feasibility of codisposal of the fly ash and mine tailings to reduce environmental impacts of Sudbury tailings disposal sites. The study includes three phases, i.e., characterization of the mine tailings, and coal fly ash, oxidation tests on the mine tailings and kinetic column permeation tests. The results of the experiments indicate that when permeated with acid mine drainage, the hydraulic conductivity of Nanticoke coal fly ash decreased more than three orders of magnitude (from 1 x 10{sup -6} to 1 x 10{sup -9} cm/s), mainly due to chemical reactions between the ash solids and acid mine drainage. Furthermore, the hydraulic gradient required for acid mine drainage to break through the coal fly ash is increased up to ten times (from 17 to 150) as compared with that for water. The results also show that the leachate from coal fly ash neutralizes the acidic pore fluid of mine tailings. The concentrations of trace elements in effluents from all kinetic column permeation tests indicated that coplacement of coal fly ash with mine tailings has the benefit of immobilizing trace elements, especially heavy metals. All regulated element concentrations from effluent during testing are well below the leachate quality criteria set by the local regulatory authority.

  13. Power-plant fly-ash utilization: a chemical processing perspective

    SciTech Connect (OSTI)

    Burnet, G.; Murtha, M.J.

    1981-01-01

    The 1976 Resource Conservation and Recovery Act (RCRA) deals with the management of solid and hazardous wastes, and encourages energy and resource recovery. Recent research has indicated that solid wastes from coal combustion, including fly ash, could be classified as hazardous under present EPA definitions. The seriousness of this possibility has been recognized and new rules for coal ash waste disposal are being considered. Ames Laboratory research on fly ash utilization as an alternative to disposal includes extraction of metals from the ash and discovery of uses for the process residues. Recovery of alumina and iron oxides by physical and chemical processing would permit large scale utilization of fly ash and help reduce dependency on imports. One of the processes investigated uses a lime-soda sinter method to form soluble aluminate compounds from mixtures of fly ash, limestone, and soda ash. The aluminates are extracted, treated to remove silicates, and precipitated: the precipitate is calcined to metallurgical grade alumina. The extract residue shows promise as a raw material for the production of Portland cement. Process economics are presented, and the effects of alumina and silica contents of the fly ash, sintering temperatures and time, and sales credits for by-products are discussed.

  14. Evaluation of rice husk ash as filler in tread compounds

    SciTech Connect (OSTI)

    Fernandes, M. R. S.; Furtado, C. R. G. E-mail: ana.furtado.sousa@gmail.com; Sousa, A. M. F. de E-mail: ana.furtado.sousa@gmail.com

    2014-05-15

    Rice which is one of the largest agriculture crops produces around 22% of rice rusk during its milling process. This material is mainly used as fuel for energy generation, which results in an ash, which disposal represents an environmental issue. The rice husk ash (RHA) contains over than 70% of silica in an amorphous form and a lot of applications is being developed for it all over the world. The use of silica as a filler in the tire industry is growing since it contributes significantly to the reduction of fuel consumption of the automobiles, allowing at the same time better traction (safety). This paper presents an evaluation of the use of RHA as filler in rubber tread compounds prepared in lab scale and compares its performance with compounds prepared with commercial silica and carbon black, the fillers normally used in tire industry. Mechanical and rheological properties are evaluated, with emphasis for tan delta as an indicator of tread performance related with rolling resistance (fuel consumption) and wet grip/traction (safety)

  15. Methods for recovering a polar solvent from a fluid stream contaminated with at least one polar impurity

    SciTech Connect (OSTI)

    Ginosar, Daniel M.; Wendt, Daniel S.

    2012-11-13

    A method of removing a polar solvent from a fluid volume contaminated with at least one polar impurity, such as a free fatty acid, is provided. The method comprises providing a fluid volume that includes at least one polar impurity dissolved in at least one solvent. The fluid volume is contacted with an expanding gas to remove the at least one solvent. The expanding gas may be dissolved into the at least one solvent in the fluid volume to form a gas-expanded solvent. The immiscibility of the polar impurities in the gas-expanded solvent enables separation of the polar impurities from the gas-expanded solvent. After separation of the polar impurities, at least one of the temperature and pressure may be reduced to separate the solvent from the expanding gas such that the clean solvent may be reused.

  16. Thermodynamic Analysis Of Pure And Impurity Doped Pentaerythritol Tetranitrate Crystals Grown At Room Temperature

    SciTech Connect (OSTI)

    Pitchimani, R; Zheng, W; Simon, S; Hope-Weeks, L; Burnham, A K; Weeks, B L

    2006-05-25

    Pentaerythritol tetranitrate (PETN) powders are used to initiate other explosives. During long-term storage, changes in powder properties can cause changes in the initiation performance. Changes in the morphology and surface area of aging powders are observed due to sublimation and growth of PETN crystals through coarsening mechanisms, (e.g. Ostwald ripening, sintering, etc.). In order to alleviate the sublimation of PETN crystals under service conditions, stabilization methods such as thermal cycling and doping with certain impurities during or after the crystallization of PETN have been proposed. In this report we present our work on the effect of impurities on the morphology and activation energy of the PETN crystals. The pure and impurity doped crystals of PETN were grown from supersaturated acetone solution by solvent evaporation technique at room temperature. The difference in the morphology of the impurity-doped PETN crystal compared to pure crystal was examined by optical microscopy. The changes in the activation energies and the evaporation rates are determined by thermogravimetric (TGA) analyses. Our activation energies of evaporation agree with earlier reported enthalpies of vaporization. The morphology and activation energy of PETN crystals doped with Ca, Na, and Fe cations are similar to that for pure PETN crystal, whereas the Zn-ion-doped PETN crystals have different morphology and decreased activation energy.

  17. Empirical correlations between the arrhenius' parameters of impurities' diffusion coefficients in CdTe crystals

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

    Shcherbak, L.; Kopach, O.; Fochuk, P.; James, R. B.; Bolotnikov, A. E.

    2015-01-21

    Understanding of self- and dopant-diffusion in semiconductor devices is essential to our being able to assure the formation of well-defined doped regions. In this paper, we compare obtained in the literature up to date the Arrhenius’ parameters (D=D0exp(–ΔEa/kT)) of point-defect diffusion coefficients and the I-VII groups impurities in CdTe crystals and films. We found that in the diffusion process there was a linear dependence between the pre-exponential factor, D0, and the activation energy, ΔEa, of different species: This was evident in the self-diffusivity and isovalent impurity Hg diffusivity as well as for the dominant IIIA and IVA groups impurities andmore » Chlorine, except for the fast diffusing elements (e.g., Cu and Ag), chalcogens O, S, and Se, halogens I and Br as well as the transit impurities Mn, Co, Fe. As a result, reasons of the lack of correspondence of the data to compensative dependence are discussed.« less

  18. Empirical correlations between the arrhenius' parameters of impurities' diffusion coefficients in CdTe crystals

    SciTech Connect (OSTI)

    Shcherbak, L.; Kopach, O.; Fochuk, P.; James, R. B.; Bolotnikov, A. E.

    2015-01-21

    Understanding of self- and dopant-diffusion in semiconductor devices is essential to our being able to assure the formation of well-defined doped regions. In this paper, we compare obtained in the literature up to date the Arrhenius’ parameters (D=D0exp(–ΔEa/kT)) of point-defect diffusion coefficients and the I-VII groups impurities in CdTe crystals and films. We found that in the diffusion process there was a linear dependence between the pre-exponential factor, D0, and the activation energy, ΔEa, of different species: This was evident in the self-diffusivity and isovalent impurity Hg diffusivity as well as for the dominant IIIA and IVA groups impurities and Chlorine, except for the fast diffusing elements (e.g., Cu and Ag), chalcogens O, S, and Se, halogens I and Br as well as the transit impurities Mn, Co, Fe. As a result, reasons of the lack of correspondence of the data to compensative dependence are discussed.

  19. The Physics of Confinement Improvement with Impurity Seeding in DIII-D

    SciTech Connect (OSTI)

    M. Murakami; G.R. McKee; G.L. Jackson; G.M. Staebler; D.R. Baker; J.A. Boedo; N.H. Brooks; K.H. Burrell; D.R. Ernst; T.E. Evans; C.M. Greenfield; R.J. Groebner; J.E. Kinsey; R.J. La Haye; L.L. Lao; A. Messiaen; J. Mandrekas; J. Ongena; C.L. Rettig; B.W. Rice; D.W. Ross; H.E. St.John; R.D. Sydora; D.M. Thomas; M.R. Wade; W.P. West

    2000-08-01

    Clear increases in confinement (from H{sub 89P} {approx} 1 to H{sub 89P} {<=} 2) and simultaneous reductions of long-wavelength turbulence have been observed in L-mode discharges in DIII-D, which are directly correlated with external impurity injection [1]. These observations provide an opportunity to understand the mechanism for confinement improvement with impurity seeding observed in a number of tokamaks [2], and to make quantitative tests of theory-based turbulence and transport models with experimental measurements. Impurity seeding can be used not only to produce a radiative mantle to reduce heat fluxes to the first wall material [3], but also as a tool to control profiles in Advanced Tokamak (AT) plasmas. Significant confinement improvements are observed with injection of noble gases (Ne, Ar, and Kr) into L-mode edge, negative central shear (sawtooth-free) discharges in DIII-D. Compared to similar reference discharges without impurity injection, confinement enhancement factor and neutron emission in neon-injected discharges are nearly doubled [Fig. 1(a,b)]. The ion and electron temperature with neon injection exhibit increased central values and profile broadening while the electron density profile becomes more peaked.

  20. Study of the impurity composition and effective plasma charge in the GOL-3 facility

    SciTech Connect (OSTI)

    Sorokina, N. V. Burdakov, A. V.; Ivanov, I. A.; Polosatkin, S. V.; Postupaev, V. V.; Rovenskikh, A. F.; Shoshin, A. A.

    2015-07-15

    Heating and confinement of plasma in a multimirror magnetic configuration have been studied at the GOL-3 facility (Budker Institute of Nuclear Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk). The experiments are aimed at estimating the densities and charge states of the main impurities in the GOL-3 plasma and determining their contribution to the effective plasma charge. Plasma with a density of ∼10{sup 15} cm{sup −3} was heated by a relativistic electron beam (1 MeV, 8 μs, ⩽200 kJ). At the end of electron beam injection, the plasma temperature reached 1 keV. The densities of impurities were determined using VUV and visible spectroscopy, as well as mass spectrometry of the residual vacuum. To determine the effective plasma charge, the experimental data were compared with the results of numerical simulations of the ionization balance of impurities. It is shown that the effective plasma charge calculated with allowance for the contributions from the main impurities does not exceed Z{sub eff} = 1.8, which cannot explain the experimentally observed improved confinement of low-density plasma.

  1. Method for determination of the degree of compensation for electrically active impurities in multivalley semiconductors

    SciTech Connect (OSTI)

    Baranskii, P. I.; Gaidar, G. P.

    2013-06-15

    A method for determination of the degree of compensation k = N{sub a}/N{sub d} for shallow impurities in n-Si crystals with a nondegenerate electron gas is suggested. Data facilitating practical determination of the degree of compensation are given.

  2. IDENTIFYING IMPURITIES IN SURPLUS NON PIT PLUTONIUM FEEDS FOR MOX OR ALTERNATIVE DISPOSITION

    SciTech Connect (OSTI)

    Allender, J; Moore, E

    2010-07-14

    This report provides a technical basis for estimating the level of corrosion products in materials stored in DOE-STD-3013 containers based on extrapolating available chemical sample results. The primary focus is to estimate the levels of nickel, iron, and chromium impurities in plutonium-bearing materials identified for disposition in the United States Mixed Oxide fuel process.

  3. pH-dependent leaching of dump coal ash - retrospective environmental analysis

    SciTech Connect (OSTI)

    Popovic, A.; Djordjevic, D. [University of Belgrade, Belgrade (Serbia). Dept. of Chemistry

    2009-07-01

    Trace and major elements in coal ash particles from dump of 'Nikola Tesla A' power plant in Obrenovac near Belgrade (Serbia) can cause pollution, due to leaching by atmospheric and surface waters. In order to assess this leaching potential, dump ash samples were subjected to extraction with solutions of decreasing pH values (8.50, 7.00, 5.50, and 4.00), imitating the reactions of the alkaline ash particles with the possible alkaline, neutral, and acidic (e.g., acid rain) waters. The most recently deposited ash represents the greatest environmental threat, while 'aged' ash, because of permanent leaching on the dump, was shown to have already lost this pollution potential. On the basis of the determined leachability, it was possible to perform an estimation of the acidity of the regional rainfalls in the last decades.

  4. Mercury retention by fly ashes from coal combustion: Influence of the unburned carbon content

    SciTech Connect (OSTI)

    Lopez-Anton, M.A.; Diaz-Somoano, M.; Martinez-Tarazona, M.R.

    2007-01-31

    The objective of this study was to evaluate the effect of unburned carbon particles present in fly ashes produced by coal combustion on mercury retention. To achieve this objective, the work was divided into two parts. The aim of the first part of the study was to estimate the amount of mercury captured by the fly ashes during combustion in power stations and the relationship of this retention to the unburned carbon content. The second part was a laboratory-scale study aimed at evaluating the retention of mercury concentrations greater than those produced in power stations by fly ashes of different characteristics and by unburned carbon particles. From the results obtained it can be inferred that the unburned carbon content is not the only variable that controls mercury capture in fly ashes. The textural characteristics of these unburned particles and of other components of fly ashes also influence retention.

  5. Gypsum treated fly ash as a liner for waste disposal facilities

    SciTech Connect (OSTI)

    Sivapullaiah, Puvvadi V.; Baig, M. Arif Ali

    2011-02-15

    Fly ash has potential application in the construction of base liners for waste containment facilities. While most of the fly ashes improve in the strength with curing, the ranges of permeabilities they attain may often not meet the basic requirement of a liner material. An attempt has been made in the present context to reduce the hydraulic conductivity by adding lime content up to 10% to two selected samples of class F fly ashes. The use of gypsum, which is known to accelerate the unconfined compressive strength by increasing the lime reactivity, has been investigated in further improving the hydraulic conductivity. Hydraulic conductivities of the compacted specimens have been determined in the laboratory using the falling head method. It has been observed that the addition of gypsum reduces the hydraulic conductivity of the lime treated fly ashes. The reduction in the hydraulic conductivity of the samples containing gypsum is significantly more for samples with high amounts of lime contents (as high as 1000 times) than those fly ashes with lower amounts of lime. However there is a relatively more increase in the strengths of the samples with the inclusion of gypsum to the fly ashes at lower lime contents. This is due to the fact that excess lime added to fly ash is not effectively converted into pozzolanic compounds. Even the presence of gypsum is observed not to activate these reactions with excess lime. On the other hand the higher amount of lime in the presence of sulphate is observed to produce more cementitious compounds which block the pores in the fly ash. The consequent reduction in the hydraulic conductivity of fly ash would be beneficial in reducing the leachability of trace elements present in the fly ash when used as a base liner.

  6. Simulation of Coal Ash Particle Deposition Experiments (Copyright 2011, American Chemical Society)

    SciTech Connect (OSTI)

    Ai, Weiguo; Kuhlman, John M

    2011-01-20

    Existing experimental ash particle deposition measurements from the literature have been simulated using the computational fluid dynamics (CFD) discrete phase model (DPM) Lagrangian particle tracking method and an existing ash particle deposition model based on the Johnson−Kendall−Roberts (JKR) theory, in the Fluent commercial CFD code. The experimental heating tube was developed to simulate ash temperature histories in a gasifier; ash-heating temperatures ranged from 1873 to 1573 K, spanning the ash-melting temperature. The present simulations used the realizable k−ε turbulence model to compute the gas flow field and the heat transfer to a cooled steel particle impact probe and DPM particle tracking for the particle trajectories and temperatures. A user-defined function (UDF) was developed to describe particle sticking/rebounding and particle detachment on the impinged wall surface. Expressions for the ash particle Young’s modulus in the model, E, versus the particle temperature and diameter were developed by fitting to the E values that were required to match the experimental ash sticking efficiencies from several particle size cuts and ash-heating temperatures for a Japanese bituminous coal. A UDF that implemented the developed stiffness parameter equations was then used to predict the particle sticking efficiency, impact efficiency, and capture efficiency for the entire ash-heating temperature range. Frequency histogram comparisons of adhesion and rebound behavior by particle size between model and experiments showed good agreement for each of the four ash-heating temperatures. However, to apply the present particle deposition model to other coals, a similar validation process would be necessary to develop the effective Young’s modulus versus the particle diameter and temperature correlation for each new coal.

  7. Influences of impurities on iodine removal efficiency of silver alumina adsorbent

    SciTech Connect (OSTI)

    Fukasawa, Tetsuo; Funabashi, Kiyomi; Kondo, Yoshikazu

    1997-08-01

    Silver impregnated alumina adsorbent (AgA), which was developed for iodine removal from off-gas of nuclear power and reprocessing plants has been tested laying emphasis on investigation of the influences gaseous impurities have on adsorbent chemical stability and iodine removal efficiency. The influences of the major impurities such as nitrogen oxides and water vapor were checked on the chemical state of impregnated silver compound (AgNO{sub 3}) and decontamination factor (DF) value. At 150{degrees}C, a forced air flow with 1.5% nitrogen oxide (NO/NO{sub 2}=1/1) reduced silver nitrate to metallic silver, whereas pure air and air with 1.5% NO{sub 2} had no effect on the chemical state of silver. Metallic silver showed a lower DF value for methyl iodide in pure air (without impurities) than silver nitrate and the lower DF of metallic silver was improved when impurities were added. At 40{degrees}C, a forced air flow with 1.5% nitrogen dioxide (NO{sub 2}) increased the AgA weight by about 20%, which was caused by the adsorption of nitric acid solution on the AgA surface. AgA with l0wt% silver showed higher weight increase than that with 24wt% silver which had lower porosity. Adsorption of acid solution lowered the DF value, which would be due to the hindrance of contact between methyl iodide and silver. The influences of other gaseous impurities were also investigated and AgA showed superior characteristics at high temperatures. 14 refs., 11 figs.

  8. Evaluation of the effects of coal fly ash amendments on the toxicity of a contaminated marine sediment

    SciTech Connect (OSTI)

    Burgess, R.M.; Perron, M.M.; Friedman, C.L.; Suuberg, E.M.; Pennell, K.G.; Cantwell, M.G.; Pelletier, M.C.; Ho, K.T.; Serbst, J.R.; Ryba, S.A.

    2009-01-15

    Approaches for cleaning up contaminated sediments range from dredging to in situ treatment. In this study, we discuss the effects of amending reference and contaminated sediments with coal fly ash to reduce the bioavailability and toxicity of a field sediment contaminated with polycyclic aromatic hydrocarbons (PAHs). Six fly ashes and a coconut charcoal were evaluated in 7-d whole sediment toxicity tests with a marine amphipod (Ampelisca abdita) and mysid (Americamysis bahia). Fly ashes with high carbon content and the coconut charcoal showed proficiency at reducing toxicity. Some of the fly ashes demonstrated toxicity in the reference treatments. It is suspected that some of this toxicity is related to the presence of ammonia associated with fly ashes as a result of postoxidation treatment to reduce nitrous oxide emissions. Relatively simple methods exist to remove ammonia from fly ash before use, and fly ashes with low ammonia content are available. Fly ashes were also shown to effectively reduce overlying water concentrations of several PAHs. No evidence was seen of the release of the metals cadmium, copper, nickel, or lead from the fly ashes. A preliminary 28-d polychaete bioaccumulation study with one of the high-carbon fly ashes and a reference sediment was also performed. Although preliminary, no evidence was seen of adverse effects to worm growth or lipid content or of accumulation of PAHs or mercury from exposure to the fly ash. These data show fly ashes with high carbon content could represent viable remedial materials for reducing the bioavailability of organic contaminants in sediments.

  9. Evaluating the Effects of the Kingston Fly Ash Release on Fish Reproduction: Spring 2009 - 2010 Studies

    SciTech Connect (OSTI)

    Greeley Jr, Mark Stephen; Adams, Marshall; McCracken, Kitty

    2012-05-01

    On December 22, 2008, a dike containing fly ash and bottom ash at the Tennessee Valley Authority's (TVA) Kingston Fossil Plant in East Tennessee failed and released a large quantity of ash into the adjacent Emory River. Ash deposits from the spill extended 4 miles upstream of the facility to Emory River mile 6 and downstream to Tennessee River mile 564 ({approx}8.5 miles downstream of the confluence of the Emory River with the Clinch River, and {approx}4 miles downstream of the confluence of the Clinch River with the Tennessee River). A byproduct of coal combustion, fly ash contains a variety of metals and other elements which, at sufficient concentrations and in specific forms, can be harmful to biological systems. The ecological effects of fly ash contamination on exposed fish populations depend on the magnitude and duration of exposure, with the most significant risk considered to come from elevated levels of certain metals in the ash, particularly selenium, on fish reproduction and fish early life stages (Lemly 1993; Besser and others 1996). The ovaries of adult female fish in a lake contaminated by coal ash were reported to have an increased frequency of atretic oocytes (dead or damaged immature eggs) and reductions in the overall numbers of developing oocytes (Sorensen 1988) associated with elevated body burdens of selenium. Larval fish exposed to selenium through maternal transfer of contaminants to developing eggs in either contaminated bodies of water (Lemly 1999) or in experimental laboratory exposures (Woock and others 1987, Jezierska and others 2009) have significantly increased incidences of developmental abnormalities. Contact of fertilized eggs and developing embryos to ash in water and sediments may also pose an additional risk to the early life stages of exposed fish populations through direct uptake of metals and other ash constituents (Jezierska and others 2009). The establishment and maintenance of fish populations is intimately associated with

  10. Final Technical Report: Effects of Impurities on Fuel Cell Performance and Durability

    SciTech Connect (OSTI)

    James G. Goodwin, Jr.; Hector Colon-Mercado; Kitiya Hongsirikarn; and Jack Z. Zhang

    2011-11-11

    The main objectives of this project were to investigate the effect of a series of potential impurities on fuel cell operation and on the particular components of the fuel cell MEA, to propose (where possible) mechanism(s) by which these impurities affected fuel cell performance, and to suggest strategies for minimizing these impurity effects. The negative effect on Pt/C was to decrease hydrogen surface coverage and hydrogen activation at fuel cell conditions. The negative effect on Nafion components was to decrease proton conductivity, primarily by replacing/reacting with the protons on the Bronsted acid sites of the Nafion. Even though already well known as fuel cell poisons, the effects of CO and NH3 were studied in great detail early on in the project in order to develop methodology for evaluating poisoning effects in general, to help establish reproducibility of results among a number of laboratories in the U.S. investigating impurity effects, and to help establish lower limit standards for impurities during hydrogen production for fuel cell utilization. New methodologies developed included (1) a means to measure hydrogen surface concentration on the Pt catalyst (HDSAP) before and after exposure to impurities, (2) a way to predict conductivity of a Nafion membranes exposed to impurities using a characteristic acid catalyzed reaction (methanol esterification of acetic acid), and, more importantly, (3) application of the latter technique to predict conductivity on Nafion in the catalyst layer of the MEA. H2-D2 exchange was found to be suitable for predicting hydrogen activation of Pt catalysts. The Nafion (ca. 30 wt%) on the Pt/C catalyst resides primarily on the external surface of the C support where it blocks significant numbers of micropores, but only partially blocks the pore openings of the meso- and macro-pores wherein lie the small Pt particles (crystallites). For this reason, even with 30 wt% Nafion on the Pt/C, few Pt sites are blocked and, hence, are

  11. Geopolymer concretes: a green construction technology rising from the ash

    SciTech Connect (OSTI)

    Allouche, E.

    2009-07-01

    Researchers at Louisiana Tech University have embarked on a multi-year research initiative to develop applications for inorganic polymer concrete, or geopolymer concrete, in the area of civil construction, and to bring solve of these applications to market. One objective was to produce a spray-on coating for use in the harsh environment of wastewater conveyance and treatment facilities. Another project is to establish relationships between fly ash composition and particle size distribution and the mechanical attributes and workability of the resulting geopolymer concrete. A third project is to develop a 'smart' geopolymer concrete whose response to a given electric current can be correlated to the stress level to which the structure is subjected. 1 fig., 6 photos.

  12. Rate limitations of lime dissolution into coal ash slag

    SciTech Connect (OSTI)

    L.K. Elliott; John A. Lucas; Jim Happ; John Patterson; Harry Hurst; Terry F. Wall

    2008-11-15

    The rate-limiting mechanisms of lime dissolution from a solid pellet into coal ash slag and synthetic slag was investigated using an experiment involving a rotating cylinder of lime in a liquid slag bath at temperatures of 1450-1650{degree}C. Scanning electron microscopy (SEM) analysis of the slag composition around the lime cylinder was used to determine the nature of the boundary layer surrounding the pellet and the calcium concentration profile. Predictions using shrinking core models of a cylindrical pellet were compared to experimental results, suggesting that diffusion through the slag boundary layer and the change of the phase of lime from solid to liquid in the boundary layer combine to limit the process. These results indicate that a combination of controlling steps: diffusion through the boundary layer and the phase change of lime from solid to liquid, must be considered when predicting lime dissolution rates. 24 refs., 5 figs., 3 tabs.

  13. Management of sewage sludge and ash containing radioactive materials.

    SciTech Connect (OSTI)

    Bachmaier, J. T.; Aiello, K.; Bastian, R. K.; Cheng, J.-J.; Chiu, W. A.; Goodman, J.; Hogan, R.; Jones, A. R.; Kamboj, S.; Lenhart, T.; Ott, W. R.; Rubin, A. B.; Salomon, S. N.; Schmidt, D. W.; Setlow, L. W.; Yu, C.; Wolbarst, A. B.; Environmental Science Division; Middlesex County Utilities Authority; U.S. EPA; N.J. Dept of Environmental Protection; NRC

    2007-01-01

    Approximately 50% of the seven to eight million metric tonnes of municipal sewage sludge produced annually in the US is reused. Beneficial uses of sewage sludge include agricultural land application, land reclamation, forestry, and various commercial applications. Excessive levels of contaminants, however, can limit the potential usefulness of land-applied sewage sludge. A recently completed study by a federal inter-agency committee has identified radioactive contaminants that could interfere with the safe reuse of sewage sludge. The study found that typical levels of radioactive materials in most municipal sewage sludge and incinerator ash do not present a health hazard to sewage treatment plant workers or to the general public. The inter-agency committee has developed recommendations for operators of sewage treatment plants for evaluating measured or estimated levels of radioactive material in sewage sludge and for determining whether actions to reduce potential exposures are appropriate.

  14. Apparatus and method for direct measurement of coal ash sintering and fusion properties at elevated temperatures and pressures

    DOE Patents [OSTI]

    Khan, M. Rashid

    1990-01-01

    A high-pressure microdilatometer is provided for measuring the sintering and fusion properties of various coal ashes under the influence of elevated pressures and temperatures in various atmospheres. Electrical resistivity measurements across a sample of coal ash provide a measurement of the onset of the sintering and fusion of the ash particulates while the contraction of the sample during sintering is measured with a linear variable displacement transducer for detecting the initiation of sintering. These measurements of sintering in coal ash at different pressures provide a mechanism by which deleterious problems due to the sintering and fusion of ash in various combustion systems can be minimized or obviated.

  15. Suppression of phosphate liberation from eutrophic lake sediment by using fly ash and ordinary Portland cement

    SciTech Connect (OSTI)

    Heng-Peng Ye; Fan-Zhong Chen; Yan-Qing Sheng; Guo-Ying Sheng; Jia-Mo Fu

    2006-08-15

    In this study, the effect of suppression on phosphate liberation from eutrophic lake sediment by using fly ash and ordinary Portland cement (OPC) was investigated by small scale experiment. A system including sediment, lake water, and several kinds of capping materials was designed to clarify the suppression of phosphate liberation from sediment under the anaerobic condition. The suppression efficiencies of fly ash, OPC and glass bead used as control material were also determined, and these effects were discussed. The suppression efficiency of glass bead was 44.4%, and those of fly ash and OPC were 84.4%, 94.9%, respectively. The suppression by fly ash and OPC was mainly carried out by the adsorption effect, in addition to the covering effect. The suppression efficiency depended on the amounts of the material used, and about 90% of liberated phosphate was suppressed by fly ash of 10.0 Kg m{sup -2}, and OPC of 6.0 Kg m{sup -2}. The concentrations of heavy metals, such as mercury, cadmium, lead, copper, zinc, chromium, silver, arsenic and nickel, in fly ash and OPC were lower than those in the environmental materials. And it was considered that the concentrations of heavy metals in fly ash and OPC were too low to influence the ecosystem in natural water region.

  16. Reduction of carbon content in waste-tire combustion ashes by bio-thermal treatment

    SciTech Connect (OSTI)

    Chen, C.C.; Lee, W.J.; Shih, S.I.; Mou, J.L.

    2009-07-01

    Application of bio-catalyst (NOE-7F) in thermal treatment can adequately dispose dark-black fly ashes from co-combustion of both waste tires and coal. After thermal treatment of fly ashes by adding 10% NOE-7F, the carbon contents reduced by 37.6% and the weight losses increased by 405%, compared with the fly ashes without mixing with NOE-7F. The combustion behaviors of wasted tires combustion fly ashes with NOE-7F were also investigated by both thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The results verify that NOE-7F has positive effects on the combustion of residual carbon and toxic polycyclic aromatic hydrocarbons (PAHs) enhance the energy release and reduce the toxicity during the process of thermal treatment. Furthermore, using NOE-7F to dispose high-carbon content fly ashes did improve the compressive strength of fly ashes and concrete mixtures. Therefore, NOE-7F is a promising additive which could decrease treatment cost of high-carbon content fly ashes and reduce the amount of survival toxic PAHs.

  17. Investigation of Fly Ash and Activated Carbon Obtained from Pulverized Coal Boilers

    SciTech Connect (OSTI)

    Edward K. Levy; Christopher Kiely; Zheng Yao

    2006-08-31

    One of the techniques for Hg capture in coal-fired boilers involves injection of activated carbon (AC) into the boiler downstream of the air preheater. Hg is adsorbed onto the AC particles and fly ash, which are then both removed in an electrostatic precipitator or baghouse. This project addressed the issues of Hg on activated carbon and on fly ash from a materials re-use point of view. It also addressed the possible connection between SCR reactors, fly ash properties and Hg capture. The project has determined the feasibility of separating AC from fly ash in a fluidized bed and of regenerating the separated AC by heating the AC to elevated temperatures in a fluidized bed. The temperatures needed to drive off the Hg from the ash in a fluidized bed have also been determined. Finally, samples of fly ash from power plants with SCR reactors for NO{sub x} control have been analyzed in an effort to determine the effects of SCR on the ash.

  18. Increase of available phosphorus by fly-ash application in paddy soils

    SciTech Connect (OSTI)

    Lee, C.H.; Lee, H.; Lee, Y.B.; Chang, H.H.; Ali, M.A.; Min, W.; Kim, S.; Kim, P.J.

    2007-07-01

    Fly ash from the coal- burning industry may be a potential inorganic soil amendment to increase rice productivity and to restore the soil nutrient balance in paddy soil. In this study, fly ash was applied at rates of 0, 40, 80, and 120 Mg ha{sup -1} in two paddy soils (silt loam in Yehari and loamy sand in Daegok). During rice cultivation, available phosphorus (P) increased significantly with fly ash application, as there was high content of P (786 mg kg{sup -1}) in the applied fly ash. In addition, high content of silicon (Si) and high pH of fly ash contributed to increased available-P content by ion competition between phosphate and silicate and by neutralization of soil acidity, respectively. With fly-ash application, water-soluble P (W-P) content increased significantly together with increasing aluminum- bound P (Al- P) and calcium- bound P (Ca- P) fractions. By contrast, iron- bound P (Fe- P) decreased significantly because of reduction of iron under the flooded paddy soil during rice cultivation. The present experiment indicated that addition of fly ash had a positive benefit on increasing the P availability.

  19. INVESTIGATION OF FLY ASH AND ACTIVATED CARBON OBTAINED FROM PULVERIZED COAL BOILERS

    SciTech Connect (OSTI)

    Edward K. Levy; Christopher Kiely

    2005-11-01

    One of the techniques for Hg capture in coal-fired boilers involves injection of activated carbon (AC) into the boiler downstream of the air preheater. Hg is adsorbed onto the AC particles and fly ash, which are then both removed in an electrostatic precipitator or baghouse. This project addresses the issues of Hg on activated carbon and on fly ash from a materials re-use point of view. It also addresses the possible connection between SCR reactors, fly ash properties and Hg capture. The project is determining the feasibility of separating AC from fly ash in a fluidized bed and of regenerating the separated AC by heating the AC to elevated temperatures in a fluidized bed. The temperatures needed to drive off the Hg from the ash in a fluidized bed are also being determined. Finally, samples of fly ash from power plants with SCR reactors for NO{sub x} control, are being analyzed to determine the effect of SCR on the ash.

  20. In-place stabilization of pond ash deposits by hydrated lime columns

    SciTech Connect (OSTI)

    Chand, S.K.; Subbarao, C.

    2007-12-15

    Abandoned coal ash ponds cover up vast stretches of precious land and cause environmental problems. Application of suitable in situ stabilization methods may bring about improvement in the geotechnical properties of the ash deposit as a whole, converting it to a usable site. In this study, a technique of in-place stabilization by hydrated lime columns was applied to large-scale laboratory models of ash ponds. Samples collected from different radial distances and different depths of the ash deposit were tested to study the improvements in the water content, dry density, particle size distribution, unconfined compressive strength, pH, hydraulic conductivity, and leachate characteristics over a period of one year. The in-place stabilization by lime column technique has been found effective in increasing the unconfined compressive strength and reducing hydraulic conductivity of pond ash deposits in addition to modifying other geotechnical parameters. The method has also proved to be useful in reducing the contamination potential of the ash leachates, thus mitigating the adverse environmental effects of ash deposits.

  1. Regeneratively cooled coal combustor/gasifier with integral dry ash removal

    DOE Patents [OSTI]

    Beaufrere, Albert H.

    1983-10-04

    A coal combustor/gasifier is disclosed which produces a low or medium combustion gas for further combustion in modified oil or gas fired furnaces or boilers. Two concentric shells define a combustion volume within the inner shell and a plenum between them through which combustion air flows to provide regenerative cooling of the inner shell for dry ash operation. A fuel flow and a combustion air flow having opposed swirls are mixed and burned in a mixing-combustion portion of the combustion volume and the ash laden combustion products flow with a residual swirl into an ash separation region. The ash is cooled below the fusion temperature and is moved to the wall by centrifugal force where it is entrained in the cool wall boundary layer. The boundary layer is stabilized against ash re-entrainment as it is moved to an ash removal annulus by a flow of air from the plenum through slots in the inner shell, and by suction on an ash removal skimmer slot.

  2. Assessment of the radiological impact of coal utilization. II. Radionuclides in western coal ash

    SciTech Connect (OSTI)

    Styron, C.E.; Bishop, C.T.; Casella, V.R.; Jenkins, P.H.; Yanko, W.H.

    1981-04-03

    A project has been initiated at Mound Facility specifically to evaluate the potential radiological impact of coal utilization. Phase I of the project included a survey of western US coal mines and an assessment of emissions from a power plant burning Western coal. Concentrations of uranium in coal from operating Western mines were slightly below the national average and roughly comparable to Eastern coal. Environmental deposition of radionuclides from stack emissions over a 20-year accumulation at a power plant burning Western coal was estimated to be 0.1 to 1.0% of measured background. Phase II of the project, the subject of the present report, has involved an interlaboratory comparison of results of radioanalytical procedures, determining partitioning coefficients for radionuclides in bottom ash and fly ash, and an assessment of the potential for migration of radionuclides from ash disposal sites. Results from the various laboratories for uranium-238, uranium-234, thorium-230, radium-226, polonium-210, thorium-232, thorium-228, and uranium-235 were generally in very good agreement. However, values for lead-210 in coal varied widely. Essentially all the nonvolatile radionuclides (uranium, radium, and thorium) from feed coal were accounted for in fly ash and bottom ash. However, 20 to 50% of the volatile radionuclides (lead and polonium) from subbituminous and lignitic coals could not be accounted for in ash, and it is assumed that this fraction exits via the stack. At the power plant burning bituminous coal, essentially all the lead and most of the polonium remained with the ash.

  3. Ca(OH)[sub 2]/fly ash sorbents for SO[sub 2] removal

    SciTech Connect (OSTI)

    Ho, C.S.; Shih, S.M. )

    1992-04-01

    In this paper, the reactivity of Ca(OH)[sub 2]/fly ash sorbent with SO[sub 2] is studied by using a fixed-bed differential reactor under the conditions simulating the bag filters of the spray-drying flue gas desulfurization. The source of fly ash and the sorbent preparation conditions affect the reactivity of the sorbent. The reactivity of the sorbent was found to be closely related to the content of the calcium silicate hydrate formed in the sorbent preparation. The sorbent has a much higher utilization of Ca(OH)[sub 2] than that of pure Ca(OH)[sub 2] sorbent, and in some range of Ca(OH)[sub 2] content the sorbent also has a higher SO[sub 2] capture capacity per unit weight of sorbent than that of pure lime. The fly ash from the Shin-Da plant of the Taiwan Power Company produced the best sorbent of all fly ashes in this study. The higher ratio of fly ash/Ca(OH)[sub 2], the higher slurrying temperature, the longer slurrying time, and the smaller particles of fly ash enhance the utilization of Ca(OH)[sub 2], but the water/solid ratio has an optimal value. The relative humidity in the reactor has a significant effect on the reactivity of Ca(PH)[sub 2]/fly ash sorbents, but the effect of the sulfation temperature is subtle.

  4. Impact of Collection Equipment on Ash Variability of Baled Corn Stover Biomass for Bioenergy

    SciTech Connect (OSTI)

    William Smith; Jeffery Einerson; Kevin Kenney; Ian J. Bonner

    2014-09-01

    Cost-effective conversion of agricultural residues for renewable energy hinges not only on the materials quality but also the biorefinerys ability to reliably measure quality specifications. The ash content of biomass is one such specification, influencing pretreatment and disposal costs for the conversion facility and the overall value of a delivered lot of biomass. The biomass harvest process represents a primary pathway for accumulation of soil-derived ash within baled material. In this work, the influence of five collection techniques on the total ash content and variability of ash content within baled corn stover in southwest Kansas is discussed. The equipment tested included a mower for cutting the corn stover stubble, a basket rake, wheel rake, or shred flail to gather the stover, and a mixed or uniform in-feed baler for final collection. The results showed mean ash content to range from 11.5 to 28.2 % depending on operational choice. Resulting impacts on feedstock costs for a biochemical conversion process range from $5.38 to $22.30 Mg-1 based on the loss of convertible dry matter and ash disposal costs. Collection techniques that minimized soil contact (shred flail or nonmowed stubble) were shown to prevent excessive ash contamination, whereas more aggressive techniques (mowing and use of a wheel rake) caused greater soil disturbance and entrainment within the final baled material. Material sampling and testing were shown to become more difficult as within-bale ash variability increased, creating uncertainty around feedstock quality and the associated costs of ash mitigation.

  5. Leachate concentrations from water leach and column leach tests on fly ash-stabilized soils

    SciTech Connect (OSTI)

    Bin-Shafique, S.; Benson, C.H.; Edil, T.B.; Hwang, K.

    2006-01-15

    Batch water leaching tests (WLTs) and column leaching tests (CLTs) were conducted on coal-combustion fly ashes, soil, and soil-fly ash mixtures to characterize leaching of Cd, Cr, Se, and Ag. The concentrations of these metals were also measured in the field at two sites where soft fine-grained soils were mechanically stabilized with fly ash. Concentrations in leachate from the WLTs on soil-fly ash mixtures are different from those on fly ash alone and cannot be accurately estimated based on linear dilution calculations using concentrations from WLTs on fly ash alone. The concentration varies nonlinearly with fly ash content due to the variation in pH with fly ash content. Leachate concentrations are low when the pH of the leachate or the cation exchange capacity (CEC) of the soil is high. Initial concentrations from CLTs are higher than concentrations from WLTs due to differences in solid-liquid ratio, pH, and solid-liquid contact. However, both exhibit similar trends with fly ash content, leachate pH, and soil properties. Scaling factors can be applied to WLT concentrations (50 for Ag and Cd, 10 for Cr and Se) to estimate initial concentrations for CLTs. Concentrations in leachate collected from the field sites were generally similar or slightly lower than concentrations measured in CLTs on the same materials. Thus, CLTs appear to provide a good indication of conditions that occur in the field provided that the test conditions mimic the field conditions. In addition, initial concentrations in the field can be conservatively estimated from WLT concentrations using the aforementioned scaling factors provided that the pH of the infiltrating water is near neutral.

  6. Evidence of preferential diffusion of impurities along grain boundaries in very pure niobium used for radio frequency cavities

    SciTech Connect (OSTI)

    Antoine, C.; Bonin, B.; Safa, H.

    1997-02-01

    In order to overcome dissipation due to impurity segregation at grain boundaries, niobium cavities are submitted to a purification annealing (1300{degree}C{plus_minus}200{degree}C under vacuum) during which titanium is evaporated onto the Nb surface. The resulting titanium layer acts as a solid state getter reacting with light impurities (H, C, N, O), thereby removing these impurities from the bulk of the niobium. Preferential titanium diffusion along grain boundaries have been studied using proton-induced x-ray emission. {copyright} {ital 1997 American Institute of Physics.}

  7. Salt-soda sinter process for recovering aluminum from fly ash

    DOE Patents [OSTI]

    McDowell, W.J.; Seeley, F.G.

    A method for recovering aluminum values from fly ash comprises sintering the fly ash with a mixture of NaCl and Na/sub 2/CO/sub 3/ to a temperature in the range 700/sup 0/ to 900/sup 0/C for a period of time sufficient to convert greater than 90% of the aluminum content of the fly ash into an acidsoluble fraction and then contacting the thus-treated fraction with an aqueous solution of nitric or sulfuric acid to effect dissolution of aluminum and other metal values in said solution.

  8. Salt-soda sinter process for recovering aluminum from fly ash

    DOE Patents [OSTI]

    McDowell, William J.; Seeley, Forest G.

    1981-01-01

    A method for recovering aluminum values from fly ash comprises sintering the fly ash with a mixture of NaCl and Na.sub.2 CO.sub.3 to a temperature in the range 700.degree.-900.degree. C. for a period of time sufficient to convert greater than 90% of the aluminum content of the fly ash into an acid-soluble fraction and then contacting the thus-treated fraction with an aqueous solution of nitric or sulfuric acid to effect dissolution of aluminum and other metal values in said solution.

  9. Salt-soda sinter process for recovering aluminum from fly ash

    SciTech Connect (OSTI)

    Mcdowell, W.J.; Seeley, F.G.

    1981-03-03

    A method for recovering aluminum values from fly ash comprises sintering the fly ash with a mixture of NaCl and Na2CO3 to a temperature in the range 700*-900* C for a period of time sufficient to convert greater than 90% of the aluminum content of the fly ash into an acid-soluble fraction and then contacting the thus-treated fraction with an aqueous solution of nitric or sulfuric acid to effect dissolution of aluminum and other metal values in said solution.

  10. Chemical Structure of Copper in Incineration Dry Scrubber and Bag Filter Ashes

    SciTech Connect (OSTI)

    Hsiao, M. C.; Wang, H. Paul; Peng, C. Y.; Huang, C. H.; Wei Yuling

    2007-02-02

    Speciation of copper in waste incineration fly ashes (dry scrubber (DS) and bag filter (BF)) has been studied by X-ray absorption near edge structural (XANES) spectroscopy in the present work. Copper species such as metallic Cu, CuO, Cu(OH)2, and a small amount of CuCO3 in the fly ashes could be distinguished by semi-quantitative analysis of the edge spectra. Interestingly, nano CuO (37%) were found in the BF fly ash, that might account for its relatively high leachability of copper.

  11. Development of a sintering process for recycling oil shale fly ash and municipal solid waste incineration bottom ash into glass ceramic composite

    SciTech Connect (OSTI)

    Zhang, Zhikun; Zhang, Lei; Li, Aimin

    2015-04-15

    Highlights: • Glass ceramic composite is prepared from oil shale fly ash and MSWI bottom ash. • A novel method for the production of glass ceramic composite is presented. • It provides simple route and lower energy consumption in terms of recycling waste. • The vitrified slag can promote the sintering densification process of glass ceramic. • The performances of products decrease with the increase of oil shale fly ash content. - Abstract: Oil shale fly ash and municipal solid waste incineration bottom ash are industrial and municipal by-products that require further treatment before disposal to avoid polluting the environment. In the study, they were mixed and vitrified into the slag by the melt-quench process. The obtained vitrified slag was then mixed with various percentages of oil shale fly ash and converted into glass ceramic composites by the subsequent sintering process. Differential thermal analysis was used to study the thermal characteristics and determine the sintering temperatures. X-ray diffraction analysis was used to analyze the crystalline phase compositions. Sintering shrinkage, weight loss on ignition, density and compressive strength were tested to determine the optimum preparation condition and study the co-sintering mechanism of vitrified amorphous slag and oil shale fly ash. The results showed the product performances increased with the increase of sintering temperatures and the proportion of vitrified slag to oil shale fly ash. Glass ceramic composite (vitrified slag content of 80%, oil shale fly ash content of 20%, sintering temperature of 1000 °C and sintering time of 2 h) showed the properties of density of 1.92 ± 0.05 g/cm{sup 3}, weight loss on ignition of 6.14 ± 0.18%, sintering shrinkage of 22.06 ± 0.6% and compressive strength of 67 ± 14 MPa. The results indicated that it was a comparable waste-based material compared to previous researches. In particular, the energy consumption in the production process was reduced

  12. GaInP semiconductor compounds doped with the Sb isovalent impurity

    SciTech Connect (OSTI)

    Skachkov, A. F.

    2015-05-15

    GaInP{sub 1−x}Sb{sub x} layers containing different Sb fractions are produced by metal-organic vaporphase epitaxy on GaAs and Ge substrates. The charge-carrier mobilities in the GaInP{sub 1−x}Sb{sub x} layers are measured at room temperature and 77 K. The room-temperature charge-carrier mobilities in the GaInP{sub 1−x}Sb{sub x} layers additionally doped with donor and acceptor impurities are measured. The photoluminescence peaks of GaInP{sub 1−x}Sb{sub x} are detected. The influence of the Sb impurity on the band gap and charge-carrier mobility in GaInP is determined.

  13. Kondo decoherence : finding the right spin model for iron impurities in gold and silver.

    SciTech Connect (OSTI)

    Costi, T. A.; Bergqvist, L.; Weichselbaum, A.; von Delft, J.; Micklitz, T.; Rosch, A.; Mavropoulos, P.; Dederichs, P. H.; Mallet, F.; Saminadayar, L.; Bauerle, C.

    2009-02-01

    We exploit the decoherence of electrons due to magnetic impurities, studied via weak localization, to resolve a long-standing question concerning the classic Kondo systems of Fe impurities in the noble metals gold and silver: which Kondo-type model yields a realistic description of the relevant multiple bands, spin, and orbital degrees of freedom? Previous studies suggest a fully screened spin S Kondo model, but the value of S remained ambiguous. We perform density functional theory calculations that suggest S=3/2. We also compare previous and new measurements of both the resistivity and decoherence rate in quasi-one-dimensional wires to numerical renormalization group predictions for S=1/2, 1, and 3/2, finding excellent agreement for S=3/2.

  14. Separation of thorium impurity from plutonium in the nitrate anion exchange process

    SciTech Connect (OSTI)

    Marsh, S.F.; Phillips, B.J.; Aldaz, E.A.; Williams, W.E.

    1989-04-01

    Thorium is a common impurity in many materials processed at the Los Alamos Plutonium Facility. Although the thorium impurity level is usually less than 1000 ppM, it frequently exceeds the maximum allowable limit of 100 ppM. Thorium is especially difficult to separate from plutonium because it accompanies plutonium in the three aqueous nitrate processes used at Los Alamos: nitrate anion exchange, oxalate precipitation, and peroxide precipitation. Nitrate anion exchange, the major aqueous plutonium purification process, has recently been modified to remove most of the thorium from sorbed plutonium by washing the column with 4.7 M nitric acid-0.007 M hydrofluoric acid. This chromatographic washing technique requires careful process control that is readily attainable with the recently developed Los Alamos On-Line Gamma Monitor. The successful separation of thorium using this modification has been demonstrated in routine, full-scale, nitrate anion exchange operations. 3 refs., 8 figs.

  15. Electrorefiner system for recovering purified metal from impure nuclear feed material

    DOE Patents [OSTI]

    Berger, John F.; Williamson, Mark A.; Wiedmeyer, Stanley G.; Willit, James L.; Barnes, Laurel A.; Blaskovitz, Robert J.

    2015-10-06

    An electrorefiner system according to a non-limiting embodiment of the present invention may include a vessel configured to maintain a molten salt electrolyte and configured to receive a plurality of alternately arranged cathode and anode assemblies. The anode assemblies are configured to hold an impure nuclear feed material. Upon application of the power system, the impure nuclear feed material is anodically dissolved and a purified metal is deposited on the cathode rods of the cathode assemblies. A scraper is configured to dislodge the purified metal deposited on the cathode rods. A conveyor system is disposed at a bottom of the vessel and configured to remove the dislodged purified metal from the vessel.

  16. Alternatives to traditional water washing used to remove impurities in superheated geothermal steam

    SciTech Connect (OSTI)

    Fisher, D.W.; Jung, D.B. [Two-Phase Engineering & Research, Inc., Santa Rosa, CA (United States)

    1996-12-31

    The method of water washing impurities from superheated geothermal steam as adopted from traditional steam boiler operations in electric power generation stations has been used for a decade and a half under several pseudonyms, e.g., de-superheating, enthalpy modification, de-scaling, etc. Water washing can be effective, but it is costly. It is not necessarily expensive to implement or operate, but the cost of unrecoverable energy lost due to steam enthalpy reduction can be quite high. Are there other ways to remove these undesirables from superheated geothermal steam? That question is the focus of this paper. Several alternatives to water washing will be proposed including dry scrubbing, oil washing, and hybrid cleaning. A discussion of the advantages and disadvantages of each method will be presented along with the various geothermal steam impurities and their effects on the process and equipment.

  17. Impurity-induced disorder in III-nitride materials and devices

    DOE Patents [OSTI]

    Wierer, Jr., Jonathan J; Allerman, Andrew A

    2014-11-25

    A method for impurity-induced disordering in III-nitride materials comprises growing a III-nitride heterostructure at a growth temperature and doping the heterostructure layers with a dopant during or after the growth of the heterostructure and post-growth annealing of the heterostructure. The post-growth annealing temperature can be sufficiently high to induce disorder of the heterostructure layer interfaces.

  18. Systematic Study of Trace Radioactive Impurities in Candidate Construction Materials for EXO-200

    SciTech Connect (OSTI)

    Leonard, D.S.; Grinberg, P.; Weber, P.; Baussan, E.; Djurcic, Z.; Keefer, G.; Piepke, A.; Pocar, A.; Vuilleumier, J.-L.; Vuilleumier, J.-M.; Akimov, D.; Bellerive, A.; Bowcock, M.; Breidenbach, M.; Burenkov, A.; Conley, R.; Craddock, W.; Danilov, M.; DeVoe, R.; Dixit, M.; Dolgolenko, A.; /Alabama U. /NRC-INMS /Neuchatel U. /Stanford U., Phys. Dept. /SLAC /Colorado State U. /Laurentian U. /Maryland U. /UC, Irvine

    2007-10-24

    The Enriched Xenon Observatory (EXO) will search for double beta decays of 136Xe. We report the results of a systematic study of trace concentrations of radioactive impurities in a wide range of raw materials and finished parts considered for use in the construction of EXO-200, the first stage of the EXO experimental program. Analysis techniques employed, and described here, include direct gamma counting, alpha counting, neutron activation analysis, and high-sensitivity mass spectrometry.

  19. Putting the Spin on Graphite: Observing the Spins of Impurity Atoms Align |

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

    Stanford Synchrotron Radiation Lightsource Putting the Spin on Graphite: Observing the Spins of Impurity Atoms Align Friday, February 28, 2014 The existence of magnetism in graphite is a very intriguing subject. The possibility to exploit the magnetic properties of a lightweight and robust material based on carbon that can also be produced and manipulated on the nanoscale fascinates scientists and engineers alike. Carbon-based materials can be made e.g. in the form of thin wires (1D), single

  20. Method for removal of plutonium impurity from americium oxides and fluorides

    DOE Patents [OSTI]

    FitzPatrick, John R.; Dunn, Jerry G.; Avens, Larry R.

    1987-01-01

    Method for removal of plutonium impurity from americium oxides and fluorides. AmF.sub.4 is not further oxidized to AmF.sub.6 by the application of O.sub.2 F at room temperature, while plutonium compounds present in the americium sample are fluorinated to volatile PuF.sub.6, which can readily be separated therefrom, leaving the purified americium oxides and/or fluorides as the solid tetrafluoride.

  1. Method for removal of plutonium impurity from americium oxides and fluorides

    DOE Patents [OSTI]

    FitzPatrick, J.R.; Dunn, J.G.; Avens, L.R.

    1987-02-13

    Method for removal of plutonium impurity from americium oxides and fluorides. AmF/sub 4/ is not further oxidized to AmF/sub 6/ by the application of O/sub 2/F at room temperature thereto, while plutonium compounds present in the americium sample are fluorinated to volatile PuF/sub 6/, which can readily be separated therefrom, leaving the purified americium oxides and/or fluorides as the solid tetrafluoride thereof.

  2. New acceptor centers of the background impurities in p-CdZnTe

    SciTech Connect (OSTI)

    Plyatsko, S. V. Rashkovetskyi, L. V.

    2013-07-15

    Low-temperature photoluminescence data are used to study the redistribution of the background impurities and host components of p-CdZnTe single crystals with a resistivity of 1-50 {Omega} cm upon their interaction with infrared laser radiation. The effect of widening of the band gap and the formation of new acceptor centers in response to laser-stimulated changes in the system of intrinsic defects are established. The activation energy of the new acceptor centers is determined.

  3. Market Assessment and Demonstration of Lignite FBC Ash Flowable Fill Applications

    SciTech Connect (OSTI)

    Alan E. Bland

    2003-09-30

    Montana-Dakota Utilities (MDU) and Western Research Institute (WRI) have been developing flowable fill materials formulated using ash from the Montana-Dakota Utilities R. M. Heskett Station in Mandan, North Dakota. MDU and WRI have partnered with the U.S. Department of Energy (DOE) and the North Dakota Industrial Commission (NDIC) to further the development of these materials for lignite-fired fluidized-bed combustion (FBC) facilities. The MDU controlled density fill (CDF) appears to be a viable engineering material and environmentally safe. WRI is pursuing the commercialization of the technology under the trademark Ready-Fill{trademark}. The project objectives were to: (1) assess the market in the Bismarck-Mandan area; (2) evaluate the geotechnical properties and environmental compatibility; and (3) construct and monitor demonstrations of the various grades of flowable fill products in full-scale demonstrations. The scope of initial phase of work entailed the following: Task I--Assess Market for MDU Flowable Fill Products; Task II--Assess Geotechnical and Environmental Properties of MDU Flowable Fill Products; and Task III--Demonstrate and Monitor MDU Flowable Fill Products in Field-Scale Demonstrations. The results of these testing and demonstration activities proved the following: (1) The market assessment indicated that a market exists in the Bismarck-Mandan area for structural construction applications, such as sub-bases for residential and commercial businesses, and excavatable fill applications, such as gas line and utility trench filling. (2) The cost of the MDU flowable fill product must be lower than the current $35-$45/cubic yard price if it is to become a common construction material. Formulations using MDU ash and lower-cost sand alternatives offer that opportunity. An estimated market of 10,000 cubic yards of MDU flowable fill products could be realized if prices could be made competitive. (3) The geotechnical properties of the MDU ash-based flowable

  4. Runaway electrons as a source of impurity and reduced fusion yield in the dense plasma focus

    SciTech Connect (OSTI)

    Lerner, Eric J.; Yousefi, Hamid R.

    2014-10-15

    Impurities produced by the vaporization of metals in the electrodes may be a major cause of reduced fusion yields in high-current dense plasma focus devices. We propose here that a major, but hitherto-overlooked, cause of such impurities is vaporization by runaway electrons during the breakdown process at the beginning of the current pulse. This process is sufficient to account for the large amount of erosion observed in many dense plasma focus devices on the anode very near to the insulator. The erosion is expected to become worse with lower pressures, typical of machines with large electrode radii, and would explain the plateauing of fusion yield observed in such machines at higher peak currents. Such runaway electron vaporization can be eliminated by the proper choice of electrode material, by reducing electrode radii and thus increasing fill gas pressure, or by using pre-ionization to eliminate the large fields that create runaway electrons. If these steps are combined with monolithic electrodes to eliminate arcing erosion, large reductions in impurities and large increases in fusion yield may be obtained, as the I{sup 4} scaling is extended to higher currents.

  5. Influence of impurities on the creep of salt from the Palo Duro Basin

    SciTech Connect (OSTI)

    Hansen, F.D.; Senseny, P.E.; Pfeifle, T.W.; Vogt, T.J.

    1987-05-01

    Twelve triaxial compression creep tests were performed on salt specimens from the Woods-Holtzclaw well in the Palo Duro Basin to assess the influence of impurities on creep deformation. Four nominal impurity levels were initially selected for investigation: pure salt, salt containing 10% anhydrite, salt containing 10% mud, and salt containing 20% mud. Subsequent petrological measurements show these idealized categories do not exist. Composition of the samples was measured by methods of wet chemistry coupled with ethylene diaminetetraacetic acid (EDTA) digestion and point counting on full-size polished sections. Overall, the 12 specimens comprise 71.6--96.6% halite, 2.4--7.5% anhydrite, and 0.2--24.7% clay. Nine of the 12 specimens are similar to many other tested specimens from the Lower San Andres Unit 5. They range from 90--97% halite and average 94% with a standard deviation of 2%. The remaining 6% impurities are disseminated clay and anhydrite. The other three specimens from the Lower San Andres Unit 4 contain large amounts (average 20%) of uniformly distributed clays and average only 75% halite. 11 refs., 21 figs., 5 tabs.

  6. Trash, ash and the phoenix : a fifth anniversary review of the Supreme Court's City of Chicago waste-to-energy combustion ash decision.

    SciTech Connect (OSTI)

    Puder, M. G.; Environmental Assessment

    1999-01-01

    In 1994, the U.S. Supreme Court held that ash generated by waste-to-energy (WTE) facilities was not exempt from Subtitle C hazardous waste management regulations under the Resource Conservation and Recovery Act (RCRA). As a result of City of Chicago v. Environmental Defense Fund, Inc., WTE installations are required to test their combustion ash and determine whether it is hazardous. The WTE industry and the municipalities utilizing WTE technologies initially feared that if significant amounts of their ash tested hazardous, the costs and liabilities associated with RCRA Subtitle C hazardous waste management requirements would pose a serious threat to the continued viability of the WTE concept. In this article, the author presents a review of the WTE industry in the five years following the decision, and finds that the specter of the decline of WTE has not materialized.

  7. Notes on the efficacy of wet versus dry screening of fly ash

    SciTech Connect (OSTI)

    Valentim, B.; Hower, J.C.; Flores, D.; Guedes, A.

    2008-08-15

    The methodology used to obtain fly ash subsamples of different sizes is generally based on wet or dry sieving methods. However, the worth of such methods is not certain if the methodology applied is not mentioned in the analytical procedure. After performing a fly ash mechanical dry, sieving, the authors compared those results with the ones obtained by laser diffraction on the same samples and found unacceptable discrepancies. A preliminary, study of a wet sieving analysis carried out on an economizer fly ash sample showed that this method was more effective than the dry sieving. The importance of standardizing the way samples are handled, pretreated and presented to the instrument of analysis are suggested and interlaboratory reproducibility trials are needed to create a common standard methodology to obtain large amounts of fly ash size fraction subsamples.

  8. 2007 American Coal Ash Association membership directory as of June 21, 2007

    SciTech Connect (OSTI)

    2007-07-01

    A listing of names, addresses, contact numbers and websites is given for 101 members of the American Coal Ash Association. Honorary members are also named. Included are power generation companies, combustion by-product manufacturers and university departments.

  9. Comprehensive phase characterization of crystalline and amorphous phases of a Class F fly ash

    SciTech Connect (OSTI)

    Chancey, Ryan T.; Stutzman, Paul; Juenger, Maria C.G.; Fowler, David W.

    2010-01-15

    A comprehensive approach to qualitative and quantitative characterization of crystalline and amorphous constituent phases of a largely heterogeneous Class F fly ash is presented. Traditionally, fly ash composition is expressed as bulk elemental oxide content, generally determined by X-ray fluorescence spectroscopy. However, such analysis does not discern between relatively inert crystalline phases and highly reactive amorphous phases of similar elemental composition. X-ray diffraction was used to identify the crystalline phases present in the fly ash, and the Rietveld quantitative phase analysis method was applied to determine the relative proportion of each of these phases. A synergistic method of X-ray powder diffraction, scanning electron microscopy, energy dispersive spectroscopy, and multispectral image analysis was developed to identify and quantify the amorphous phases present in the fly ash.

  10. Utilizing fly ash particles to produce low-cost metal matrix composites

    SciTech Connect (OSTI)

    Withers, G.

    2008-07-01

    Metal matrix composites (MMCs) are a blend of fine ceramic particles mixed with metals such as aluminium or magnesium. Fly ash is considerably cheaper than ceramics; aluminium-fly ash composites cost less than 60% of conventional aluminium-SiC composites making them attractive to automakers striving for lower weight and cheaper materials for brake rotors or brake drums. Ultalite.com has consulted with US researchers to to find the optimum requirements of the fly ash needed to make MMCs. Particle size 20-40 microns, low calcium oxide content and spherical particles were identified. The desired particles once extracted are stirred into molten aluminum and the resulting composite is into ingots for shipment to a casting facility. Dynamometer testing has shown that aluminium-fly ash composite brake drums have better performance and wear than cast iron drums. 6 figs., 1 tab.

  11. Investigation of air-entraining admixture dosage in fly ash concrete

    SciTech Connect (OSTI)

    Ley, M.T.; Harris, N.J.; Folliard, K.J.; Hover, K.C.

    2008-09-15

    The amount of air-entraining admixture (AEA) needed to achieve a target air content in fresh concrete can vary significantly with differences in the fly ash used in the concrete. The work presented in this paper evaluates the ability to predict the AEA dosage on the basis of tests on the fly ash alone. All results were compared with the dosage of AEA required to produce an air content of 6% in fresh concrete. Fly ash was sampled from six separate sources. For four of these sources, samples were obtained both before and after the introduction of 'low-NOx burners'. Lack of definitive data about the coal itself or the specifics of the burning processes prevents the ability to draw specific conclusions about the impact of low-NOx burners on AEA demand. Nevertheless, the data suggest that modification of the burning process to meet environmental quality standards may affect the fly ash-AEA interaction.

  12. Apparatus having inductively coupled coaxial coils for measuring buildup of slay or ash in a furnace

    DOE Patents [OSTI]

    Mathur, Mahendra P.; Ekmann, James M.

    1989-01-01

    The buildup of slag or ash on the interior surface of a furnace wall is monitored by disposing two coils to form a transformer which is secured adjacent to the inside surface of the furnace wall. The inductive coupling between the two coils of the transformer is affected by the presence of oxides of iron in the slag or ash which is adjacent to the transformer, and the application of a voltage to one winding produces a voltage at the other winding that is related to the thickness of the slag or ash buildup on the inside surface of the furnace wall. The output of the other winding is an electrical signal which can be used to control an alarm or the like or provide an indication of the thickness of the slag or ash buildup at a remote location.

  13. Cesium trapping characteristics on fly ash filter according to different carrier gases

    SciTech Connect (OSTI)

    Shin, Jin-Myeong; Park, Jang-Jin; Song, Kee-Chan

    2007-07-01

    Fly ash, which is a kind of waste from a coal fired power plant, has been used as a trapping material because it contains silica and alumina suitable for forming pollucite (CsAlSi{sub 2}O{sub 6}). Fly ash is sintered in order to fabricate it into a self-standing filter. The effect of a carrier gas on a cesium trapping quantity is investigated to analyze the cesium trapping characteristics by the fly ash filter in a lab-scale experimental apparatus. The chemical form of the cesium trapped on the filter after trapping cesium is identified to be a pollucite phase regardless of the type of carrier gas. The trapping efficiency of cesium by the fly ash filter under the air and NO{sub x}/air conditions is up to 99.0 %. However, the trapping efficiency of the cesium under the SO{sub x} condition was decreased to 80.0 %. (authors)

  14. Removal of radium from acidic solutions containing same by adsorption on coal fly ash

    DOE Patents [OSTI]

    Scheitlin, Frank M.

    1984-01-01

    The invention is a process for the removal of radium from acidic aqueous solutions. In one aspect, the invention is a process for removing radium from an inorganic-acid solution. The process comprises contacting the solution with coal fly ash to effect adsorption of the radium on the ash. The radium-containing ash then is separated from the solution. The process is simple, comparatively inexpensive, and efficient. High radium-distribution coefficients are obtained even at room temperature. Coal fly ash is an inexpensive, acid-resistant, high-surface-area material which is available in large quantities throughout the United States. The invention is applicable, for example, to the recovery of .sup.226 Ra from nitric acid solutions which have been used to leach radium from uranium-mill tailings.

  15. Crystal structure of the N-terminal region of human Ash2L shows...

    Office of Scientific and Technical Information (OSTI)

    of the N-terminal region of human Ash2L shows a winged-helix motif involved in DNA binding Citation Details In-Document Search Title: Crystal structure of the N-terminal ...

  16. Treated bottom ash medium and method of arsenic removal from drinking water

    DOE Patents [OSTI]

    Gadgil, Ashok

    2009-06-09

    A method for low-cost arsenic removal from drinking water using chemically prepared bottom ash pre-treated with ferrous sulfate and then sodium hydroxide. Deposits on the surface of particles of bottom ash form of activated iron adsorbent with a high affinity for arsenic. In laboratory tests, a miniscule 5 grams of pre-treated bottom ash was sufficient to remove the arsenic from 2 liters of 2400 ppb (parts per billion) arsenic-laden water to a level below 50 ppb (the present United States Environmental Protection Agency limit). By increasing the amount of pre-treated bottom ash, even lower levels of post-treatment arsenic are expected. It is further expected that this invention supplies a very low-cost solution to arsenic poisoning for large population segments.

  17. Fan System Optimization Improves Production and Saves Energy at Ash Grove Cement Plant

    SciTech Connect (OSTI)

    2002-05-01

    This case study describes an optimization project implemented on a fan system at Ash Grove Cement Company, which led to annual energy and maintenance savings of $16,000 and 175,000 kilowatt-hours (kWh).

  18. Inclusion property of Cs, Sr, and Ba impurities in LiCl crystal formed by layer-melt crystallization

    SciTech Connect (OSTI)

    Choi, Jung-Hoon; Cho, Yung-Zun; Lee, Tae-Kyo; Eun, Hee-Chul; Kim, Jun-Hong; Park, Hwan-Seo; Kim, In-Tae; Park, Geun-Il

    2013-07-01

    Pyroprocessing is one of the promising technologies enabling the recycling of spent nuclear fuels from a commercial light water reactor (LWR). In general, pyroprocessing uses dry molten salts as electrolytes. In particular, LiCl waste salt after pyroprocessing contains highly radioactive I/II group fission products mainly composed of Cs, Sr, and Ba impurities. Therefore, it is beneficial to reuse LiCl salt in the pyroprocessing as an electrolyte for economic and environmental issues. Herein, to understand the inclusion property of impurities within LiCl crystal, the physical properties such as lattice parameter change, bulk modulus, and substitution enthalpy of a LiCl crystal having 0-6 at% Cs{sup +} or Ba{sup 2+} impurities under existence of 1 at% Sr{sup 2+} impurity were calculated via the first-principles density functional theory. The substitution enthalpy of LiCl crystals having 1 at% Sr{sup 2+} showed slightly decreased value than those without Sr{sup 2+} impurity. Therefore, through the substitution enthalpy calculation, it is expected that impurities will be incorporated within LiCl crystal as co-existed form rather than as a single component form. (authors)

  19. Brick manufacture with fly ash from Illinois coals. Quarterly technical report, September 1, 1994--November 30, 1994

    SciTech Connect (OSTI)

    Hughes, R.E.; Dreher, G.; Frost, J.; Moore, D.; Rostam-Abadi, M.; Fiocchi, T.; Swartz, D.

    1995-03-01

    This investigation seeks to utilize fly ash in fired-clay products such as building and patio bricks, ceramic blocks, field and sewer tile, and flower pots. This goal is accomplished by (1) one or more plant-scale, 5000-brick tests with fly ash mixed with brick clays at the 20% or higher level; (2) a laboratory-scale study to measure the firing reactions of a range of compositions of clay and fly ash mixtures; (3) a technical and economic study to evaluate the potential environmental and economic benefits of brick manufacture with fly ash. Bricks and feed materials will be tested for compliance with market specifications and for leachability of pollutants derived from fly ash. The laboratory study will combine ISGS databases, ICCI-supported characterization methods, and published information to improve predictions of the firing characteristics of Illinois fly ash and brick clay mixtures. Because identical methods are used to test clay firing and coal ash fusion, and because melting mechanisms are the same, improved coal ash fusion predictions are an expected result of this research. If successful, this project should convert an environmental problem (fly ash) into valuable products - bricks. During this quarter, the authors set up the manufacturing run at Colonial Brick Co., provided an expanded NEPA questionnaire for DOE, made preliminary arrangements for a larger brick manufacturing run at Marseilles Brick Co., revised laboratory procedures for selective dissolution analysis, and began characterization of brick clays that could be mixed with fly ash for fired-clay products.

  20. Geopolymeric adsorbents from fly ash for dye removal from aqueous solution

    SciTech Connect (OSTI)

    Li, L.; Wang, S.B.; Zhu, Z.H.

    2006-08-01

    Adsorbents from coal fly ash treated by a solid-state fusion method using NaOH were prepared. It was found that amorphous aluminosilicate, geopolymers would be formed. These fly ash-derived inorganic polymers were assessed as potential adsorbents for removal of some basic dyes, methylene blue and crystal violet, from aqueous solution. It was found that the adsorption capacity of the synthesised adsorbents depends on the preparation conditions such as NaOH:fly-ash ratio and fusion temperature with the optimal conditions being at 1.2:1 weight ratio of Na:fly-ash at 250-350{sup o}C. The synthesised materials exhibit much higher adsorption capacity than fly ash itself and natural zeolite. The adsorption isotherm can be fitted by Langmuir and Freundlich models while the two-site Langmuir model produced the best results. It was also found that the fly ash derived geopolymeric adsorbents show higher adsorption capacity for crystal violet than methylene blue and the adsorption temperature influences the adsorption capacity. Kinetic studies show that the adsorption process follows the pseudo second-order kinetics.

  1. Effect of temperature on the hydration of Portland cement blended with siliceous fly ash

    SciTech Connect (OSTI)

    Deschner, Florian; Lothenbach, Barbara; Winnefeld, Frank; Neubauer, Jrgen

    2013-10-15

    The effect of temperature on the hydration of Portland cement pastes blended with 50 wt.% of siliceous fly ash is investigated within a temperature range of 7 to 80 C. The elevation of temperature accelerates both the hydration of OPC and fly ash. Due to the enhanced pozzolanic reaction of the fly ash, the change of the composition of the CSH and the pore solution towards lower Ca and higher Al and Si concentrations is shifted towards earlier hydration times. Above 50 C, the reaction of fly ash also contributes to the formation of siliceous hydrogarnet. At 80 C, ettringite and AFm are destabilised and the released sulphate is partially incorporated into the CSH. The observed changes of the phase assemblage in dependence of the temperature are confirmed by thermodynamic modelling. The increasingly heterogeneous microstructure at elevated temperatures shows an increased density of the CSH and a higher coarse porosity. -- Highlights: The reaction of quartz powder at 80 C strongly enhances the compressive strength. Almost no strength increase of fly ash blended OPC at 80 C was found after 2 days. Siliceous hydrogarnet is formed upon the reaction of fly ash at high temperatures. Temperature dependent change of the system was simulated by thermodynamic modelling. Destabilisation of ettringite above 50 C correlates with sulphate content of CSH.

  2. Industrial properties of lignitic and lignocellulosic fly ashes from Turkish sources

    SciTech Connect (OSTI)

    Demirbas, A.; Cetin, S.

    2006-01-21

    Fly ash is an inorganic matter from combustion of the carbonaceous solid fuels. More than half the electricity in Turkey is produced from lignite-fired power plants. This energy production has resulted in the formation of more than 13 million tons of fly ash waste annually. The presence of carbon in fly ash inducing common faults include adding unwanted black color and adsorbing process or product materials such as water and chemicals. One of the reasons for not using fly ash directly is its carbon content. For some uses carbon must be lower than 3%. Fly ash has been used for partial replacement of cement, aggregate, or both for nearly 70 years, and it is still used on a very limited scale in Turkey. The heavy metal content of industrial wastewaters is an important source of environmental pollution. Each of the three major oxides (SiO{sub 2} + Al{sub 2}O{sub 3} + Fe{sub 2}O{sub 3}) in fly ash can be ideal as a metal adsorbent.

  3. Selenium And Arsenic Speciation in Fly Ash From Full-Scale Coal-Burning Utility Plants

    SciTech Connect (OSTI)

    Huggins, F.E.; Senior, C.L.; Chu, P.; Ladwig, K.; Huffman, G.P.; /Kentucky U. /Reaction Engin. Int. /Elect. Power Res. Inst., Palo Alto

    2007-07-09

    X-ray absorption fine structure spectroscopy has been used to determine directly the oxidation states and speciation of selenium and arsenic in 10 fly ash samples collected from full-scale utility plants. Such information is needed to assess the health risk posed by these elements in fly ash and to understand their behavior during combustion and in fly ash disposal options, such as sequestration in tailings ponds. Selenium is found predominantly as Se(IV) in selenite (SeO{sub 3}{sup 2-}) species, whereas arsenic is found predominantly as As(V) in arsenate (AsO{sub 4}{sup 3-}) species. Two distinct types of selenite and arsenate spectra were observed depending upon whether the fly ash was derived from eastern U.S. bituminous (Fe-rich) coals or from western subbituminous or lignite (Ca-rich) coals. Similar spectral details were observed for both arsenic and selenium in the two different types of fly ash, suggesting that the post-combustion behavior and capture of both of these elements are likely controlled by the same dominant element or phase in each type of fly ash.

  4. Identifying fly ash at a distance from fossil fuel power stations

    SciTech Connect (OSTI)

    Flanders, P.J.

    1999-02-15

    A method has been developed to identify fly ash originating at fossil fuel power stations, even at a distance where the ash level is lower by a factor of 1000 from that close to a source. Until now such detection has been difficult and uncertain. The technique combines collection of particles, measurement of magnetization and coercive field, and microscopy. The analysis depends on the fact that ash from iron sulfide in fossil fuels is in the form of spherical magnetite. These particles have a relatively high coercive field H{sub c}, near 135 Oe, compared with airborne particulates from soil erosion which have an H{sub c} of {approximately}35 Oe. The coercive field of any sample therefore gives an indication for the percentage of fly ash relative to the total amount of magnetic material that is airborne. The concentration of ash from a large, isolated coal burning power station is found to fall off with the distance from the source, approximately as D{sup {minus}1}. As D increases there is a drop in H{sub c}, associated with the reduced amount of fly ash relative to the airborne particulates from soil erosion.

  5. Generalized contexts and consistent histories in quantum mechanics

    SciTech Connect (OSTI)

    Losada, Marcelo; Laura, Roberto

    2014-05-15

    We analyze a restriction of the theory of consistent histories by imposing that a valid description of a physical system must include quantum histories which satisfy the consistency conditions for all states. We prove that these conditions are equivalent to imposing the compatibility conditions of our formalism of generalized contexts. Moreover, we show that the theory of consistent histories with the consistency conditions for all states and the formalism of generalized context are equally useful representing expressions which involve properties at different times.

  6. Technology for the Recovery of Fuel and Adsorbent Carbons from Coal Burning Utility Ash Ponds and Landfills

    SciTech Connect (OSTI)

    J.G. Groppo; T.L. Robl

    2005-09-30

    lightweight aggregate and recover a high-grade fuel product. Spiral concentration provided acceptable grade lightweight aggregate with yields of only 10 to 20%. Incorporating a sieve bend into the process to recover coarse, porous ash particles from the outside race of the spirals increased aggregate yield to as high as 75%, however, the carbon content of the aggregate also increased. An opening size of 28 mesh on the sieve bend appeared to be sufficient. Lightweight concrete blocks (28 to 32 lbs) were produced from bottom ash and results show that acceptable strength could be attained with a cement/concrete ratio as low as 1/4. A mobile Proof-of-Concept (POC) field unit was designed and fabricated to meet the processing objectives of the project. The POC plant consisted of two trailer-mounted modules and was completely self sufficient with respect to power and water requirements. The POC unit was hauled to Coleman Station and operated at a feed rate of 2 tph. Results showed that the spirals operated similarly to previous pilot-scale operations and a 500 lb composite sample of coarse carbon was collected with a grade of 51.7% C or 7279 Btu/lb. Flotation results compared favorably with release analysis and 500 lbs of composite froth product was collected with a grade of 35% C or 4925 Btu/lb. The froth product was dewatered to 39% moisture with vacuum filtration. Pan pelletization and briquetting were evaluated as a means of minimizing handling concerns. Rotary pan pelletization produced uniform pellets with a compressive strength of 4 lbf without the use of any binder. Briquettes were produced by blending the coarse and fine carbon products at a ratio of 1:10, which is the proportion that the two products would be produced in a commercial operation. Using 3% lime as a binder produced the most desirable briquettes with respect to strength, attrition and drop testing. Additionally, the POC carbon products compared favorably with commercial activated carbon when used for removal

  7. Silicon materials task of the low cost solar array project (Phase III). Effect of impurities and processing on silicon solar cells. Phase III summary and seventeenth quarterly report, Volume 1: characterization methods for impurities in silicon and impurity effects data base

    SciTech Connect (OSTI)

    Hopkins, R.H.; Davis, J.R.; Rohatgi, A.; Campbell, R.B.; Blais, P.D.; Rai-Choudhury, P.; Stapleton, R.E.; Mollenkopf, H.C.; McCormick, J.R.

    1980-01-01

    The object of Phase III of the program has been to investigate the effects of various processes, metal contaminants and contaminant-process interactions on the performance of terrestrial silicon solar cells. The study encompassed a variety of tasks including: (1) a detailed examination of thermal processing effects, such as HCl and POCl/sub 3/ gettering on impurity behavior, (2) completion of the data base and modeling for impurities in n-base silicon, (3) extension of the data base on p-type material to include elements likely to be introduced during the production, refining, or crystal growth of silicon, (4) effects on cell performance on anisotropic impurity distributions in large CZ crystals and silicon webs, and (5) a preliminary assessment of the permanence of the impurity effects. Two major topics are treated: methods to measure and evaluate impurity effects in silicon and comprehensive tabulations of data derived during the study. For example, discussions of deep level spectroscopy, detailed dark I-V measurements, recombination lifetime determination, scanned laser photo-response, and conventional solar cell I-V techniques, as well as descriptions of silicon chemical analysis are included. Considerable data are tabulated on the composition, electrical, and solar cell characteristics of impurity-doped silicon.

  8. 488-4D ASH LANDFILL CLOSURE CAP HELP MODELING

    SciTech Connect (OSTI)

    Phifer, M.

    2014-11-17

    At the request of Area Completion Projects (ACP) in support of the 488-4D Landfill closure, the Savannah River National Laboratory (SRNL) has performed Hydrologic Evaluation of Landfill Performance (HELP) modeling of the planned 488-4D Ash Landfill closure cap to ensure that the South Carolina Department of Health and Environmental Control (SCDHEC) limit of no more than 12 inches of head on top of the barrier layer (saturated hydraulic conductivity of no more than 1.0E-05 cm/s) in association with a 25-year, 24-hour storm event is not projected to be exceeded. Based upon Weber 1998 a 25-year, 24-hour storm event at the Savannah River Site (SRS) is 6.1 inches. The results of the HELP modeling indicate that the greatest peak daily head on top of the barrier layer (i.e. geosynthetic clay liner (GCL) or high density polyethylene (HDPE) geomembrane) for any of the runs made was 0.079 inches associated with a peak daily precipitation of 6.16 inches. This is well below the SCDHEC limit of 12 inches.

  9. Hydration studies of calcium sulfoaluminate cements blended with fly ash

    SciTech Connect (OSTI)

    Garca-Mat, M.; De la Torre, A.G.; Len-Reina, L.; Aranda, M.A.G.; CELLS-Alba synchrotron, Carretera BP 1413, Km. 3.3, E-08290 Cerdanyola, Barcelona ; Santacruz, I.

    2013-12-15

    The main objective of this work is to study the hydration and properties of calcium sulfoaluminate cement pastes blended with fly ash (FA) and the corresponding mortars at different hydration ages. Laboratory X-ray powder diffraction, rheological studies, thermal analysis, porosimetry and compressive strength measurements were performed. The analysis of the diffraction data by Rietveld method allowed quantifying crystalline phases and overall amorphous contents. The studied parameters were: i) FA content, 0, 15 and 30 wt.%; and ii) water addition, water-to-CSA mass ratio (w/CSA = 0.50 and 0.65), and water-to-binder mass ratio (w/b = 0.50). Finally, compressive strengths after 6 months of 0 and 15 wt.% FA [w/CSA = 0.50] mortars were similar: 73 2 and 72 3 MPa, respectively. This is justified by the filler effect of the FA as no strong evidences of reactivity of FA with CSA were observed. These results support the partial substitution of CSA cements with FA with the economic and environmental benefits.

  10. Fibrous Fillers to Manufacture Ultra High Ash/Performance Paper

    SciTech Connect (OSTI)

    Dr. VIjay K. Mathur

    2009-04-30

    The paper industry is one of the largest users of energy and emitters of CO2 in the US manufacturing industry. In addition to that, it is facing tremendous financial pressure due to lower cost imports. The fine paper industry has shrunk from 15 million tons per year production to 10 million tons per year in the last 5 years. This has resulted in mill closures and job loses. The AF&PA and the DOE formed a program called Agenda 2020 to help in funding to develop breakthrough technologies to provide help in meeting these challenges. The objectives of this project were to optimize and scale-up Fibrous Fillers technology, ready for commercial deployment and to develop ultra high ash/high performance paper using Fibrous Fillers. The goal was to reduce energy consumption, carbon footprint, and cost of manufacturing paper and related industries. GRI International (GRI) has been able to demonstrate the techno - economic feasibility and economic advantages of using its various products in both handsheets as well as in commercial paper mills. GRI has also been able to develop sophisticated models that demonstrate the effect of combinations of GRI's fillers at multiple filler levels. GRI has also been able to develop, optimize, and successfully scale-up new products for use in commercial paper mills.

  11. Comparing Metal Leaching and Toxicity from High pH, Low pH, and High Ammonia Fly Ash

    SciTech Connect (OSTI)

    Palumbo, Anthony Vito; Phillips, Jana Randolph; Fagan, Lisa Anne; Drake, Meghan M; Ruther, Rose Emily; Fisher, L. Suzanne; Amonette, J. E.

    2007-01-01

    Previous work with both class F and class C fly ash indicated minimal leaching from most fly ashes tested. However, the addition of NOx removal equipment might result in higher levels of ammonia in the fly ash. We have recently been testing fly ash with a wide range of pH (3.7-12.4) originating from systems with NOx removal equipment. Leaching experiments were done using dilute CaCl2 solutions in batch and columns and a batch nitric acid method. All methods indicated that the leaching of heavy metals was different in the highest ammonia sample tested and the high pH sample. However, toxicity testing with the Microtox system has indicated little potential toxicity in leachates except for the fly ash at the highest pH (12.4). When the leachate from the high pH fly ash was neutralized, toxicity was eliminated.

  12. Comparing metal leaching and toxicity from high pH, low pH, and high ammonia fly ash

    SciTech Connect (OSTI)

    Palumbo, Anthony V.; Tarver, Jana R.; Fagan, Lisa A.; McNeilly, Meghan S.; Ruther, Rose; Fisher, L. S.; Amonette, James E.

    2007-07-01

    Previous work with both class F and class C fly ash indicated minimal leaching from most fly ashes tested. However, the addition of NOx removal equipment might result in higher levels of ammonia in the fly ash. We have recently been testing fly ash with a wide range of pH (3.712.4) originating from systems with NOx removal equipment. Leaching experiments were done using dilute CaCl2 solutions in batch and columns and a batch nitric acid method. All methods indicated that the leaching of heavy metals was different in the highest ammonia sample tested and the high pH sample. However, toxicity testing with the Microtox* system has indicated little potential toxicity in leachates except for the fly ash at the highest pH (12.4). When the leachate from the high pH fly ash was neutralized, toxicity was eliminated.

  13. Trophic structure and metal bioaccumulation differences in multiple fish species exposed to coal ash-associated metals

    SciTech Connect (OSTI)

    Otter, Ryan; Bailey, Frank; Fortner, Allison M; Adams, Marshall

    2012-01-01

    On December 22, 2008 a dike containing coal fly ash from the Tennessee Valley Authority Kingston Fossil Plant near Kingston Tennessee USA failed and resulted in the largest coal ash spill in U.S. history. Coal ash, the by-product of coal combustion, is known to contain multiple contaminants of concern, including arsenic and selenium. The purpose of this study was to investigate the bioaccumulation of arsenic and selenium and to identify possible differences in trophic dynamics in feral fish at various sites in the vicinity of the Kingston coal ash spill. Elevated levels of arsenic and selenium were observed in various tissues of largemouth bass, white crappie, bluegill and redear sunfish from sites associated with the Kingston coal ash spill. Highest concentrations of selenium were found in redear sunfish with liver concentrations as high as 24.83 mg/kg dry weight and ovary concentrations up to 10.40 mg/kg dry weight at coal ash-associated sites. To help explain the elevated selenium levels observed in redear sunfish, investigations into the gut pH and trophic dynamics of redear sunfish and bluegill were conducted which demonstrated a large difference in the gut physiology between these two species. Redear sunfish stomach and intestinal pH was found to be 1.1 and 0.16 pH units higher than in bluegill, respectively. In addition, fish from coal ash-associated sites showed enrichment of 15N & 13C compared to no ash sites, indicating differences in food web dynamics between sites. These results imply the incorporation of coal ash-associated compounds into local food webs and/or a shift in diet at ash sites compared to the no ash reference sites. Based on these results, further investigation into a broader food web at ash-associated sites is warranted.

  14. Coal Ash Resources Research Consortium. Annual report and selected publications, 1 July 1992--30 June 1993

    SciTech Connect (OSTI)

    Pflughoeft-Hassett, D.F.; Dockter, B.A.; Eylands, K.E.; Hassett, D.J.; O`Leary, E.M.

    1994-04-01

    The Coal Ash Resources Research Consortium (CARRC, pronounced cars), formerly the Western Fly Ash Research, Development, and Data Center (WFARDDC), has continued fundamental and applied scientific and engineering research focused on promoting environmentally safe, economical use of coal combustion fly ash. The research tasks selected for the year included: (1) Coal Ash Properties Database Maintenance and Expansion, (2) Investigation of the High-Volume Use of Fly Ash for Flowable Backfill Applications, (3) Investigation of Hydrated Mineralogical Phases in Coal Combustion By-Products, (4) Comparison of Department of Transportation Specifications for Coal Ash Utilization, (5) Comparative Leaching Study of Coal Combustion By-Products and Competing Construction Materials, (6) Application of CCSEM for Coal Ash Characterization, (7) Determination of Types and Causes of Efflorescence in Regional Concrete Products, and (8) Sulfate Resistance of Fly Ash Concrete: A Literature Review and Evaluation of Research Priorities. The assembly of a database of information on coal fly ash has been a focus area for CARRC since its beginning in 1985. This year, CARRC members received an updated run time version of the Coal Ash Properties Database (CAPD) on computer disk for their use. The new, user-friendly database management format was developed over the year to facilitate the use of CAPD by members as well as CARRC researchers. It is anticipated that this direct access to CAPD by members as well as CARRC researchers. It is anticipated that this direct access to CAPD by members will be beneficial to each company`s utilization efforts, to CARRC, and to the coal ash industry in general. Many additions and improvements were made to CAPD during the year, and a three-year plan for computer database and modeling related to coal ash utilization was developed to guide both the database effort and the research effort.

  15. Brick manufacture with fly ash from Illinois coals. Quarterly report, 1 December 1994--28 February 1995

    SciTech Connect (OSTI)

    Hughes, R.E.; Dreher, G.; Frost, J.; Moore, D.; Rostam-Abadi, M.; Fiocchi, T.; Swartz, D.

    1995-12-31

    This investigation seeks to utilize fly ash in fired-clay products such as building and patio bricks, ceramic blocks, field and sewer tile, and flower pots. This goal is accomplished by (1) one or more plant-scale, 5000-brick tests with fly ash mixed with brick clays at the 20% or higher level; (2) a laboratory-scale study to measure the firing reactions of a range of compositions of clay and fly ash mixtures; (3) a preliminary study to evaluate the potential environmental and economic benefits of brick manufacture with fly ash. Bricks and feed materials will be tested for compliance with market specifications and for leachability of pollutants derived from fly ash. The laboratory study will combine ISGS databases, ICCI-supported characterization methods, and published information to improve predictions of the firing characteristics of Illinois fly ash and brick clay mixtures. Because identical methods are used to test clay firing and coal ash fusion, and because melting mechanisms are the same, improved coal ash fusion predictions are an additional expected result of this research. If successful, this project should convert a disposal problem (fly ash) into valuable products-bricks. During this quarter we set up the manufacturing run at Colonial Brick Co., finalized arrangements for a larger brick manufacturing run at Marseilles Brick Co. in YR2, revised our laboratory procedures for selective dissolution analysis, obtained information to select three standard fly ashes, and continued our characterization of brick clays that could be mixed with fly ash for fired-clay products. Due to delays in other areas, we began construction of the optimization program for year 2. We discovered recently that fly ash dust will be an unanticipated problem at the brick plant.

  16. Thermal and hydrometallurgical recovery methods of heavy metals from municipal solid waste fly ash

    SciTech Connect (OSTI)

    Kuboňová, L.

    2013-11-15

    Highlights: • MSW fly ash was thermally and hydrometallurgically treated to remove heavy metals. • More than 90% of easy volatile heavy metals (Cd and Pb) were removed thermally. • More than 90% of Cd, Cr, Cu an Zn were removed by alkaline – acid leaching. • The best results were obtained for the solution of 3 M NaOH and 2 M H{sub 2}SO{sub 4}. - Abstract: Heavy metals in fly ash from municipal solid waste incinerators are present in high concentrations. Therefore fly ash must be treated as a hazardous material. On the other hand, it may be a potential source of heavy metals. Zinc, lead, cadmium, and copper can be relatively easily removed during the thermal treatment of fly ash, e.g. in the form of chlorides. In return, wet extraction methods could provide promising results for these elements including chromium and nickel. The aim of this study was to investigate and compare thermal and hydrometallurgical treatment of municipal solid waste fly ash. Thermal treatment of fly ash was performed in a rotary reactor at temperatures between 950 and 1050 °C and in a muffle oven at temperatures from 500 to 1200 °C. The removal more than 90% was reached by easy volatile heavy metals such as cadmium and lead and also by copper, however at higher temperature in the muffle oven. The alkaline (sodium hydroxide) and acid (sulphuric acid) leaching of the fly ash was carried out while the influence of temperature, time, concentration, and liquid/solid ratio were investigated. The combination of alkaline-acidic leaching enhanced the removal of, namely, zinc, chromium and nickel.

  17. Remedial Investigation Report on Chestnut Ridge Operable Unit 2 (Filled Coal Ash Pond/Upper McCoy Branch) at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee. Volume 1. Main Text

    SciTech Connect (OSTI)

    Not Available

    1994-08-01

    This document is a report on the remedial investigation (RI) of Chestnut Ridge Operable Unit (OU) 2 at the Oak Ridge Y-12 Plant. Chestnut Ridge OU 2 consists of Upper McCoy Branch (UMB), the Filled Coal Ash Pond (FCAP), and the area surrounding the Sluice Channel formerly associated with coal ash disposal in the FCAP. Chestnut Ridge OU 2 is located within the U.S. Department of Energy`s (DOE`s) Oak Ridge Reservation in Anderson County, Tennessee, approximately 24 miles west of Knoxville. The pond is an 8.5-acre area on the southern slope of Chestnut Ridge, 0.5 mile south of the main Y-12 Plant and geographically separated from the Y-12 Plant by Chestnut Ridge. The elevation of the FCAP is {approximately} 950 ft above mean sea level (msl), and it is relatively flat and largely vegetated. Two small ponds are usually present at the northeast and northwest comers of the FCAP. The Sluice Channel Area extends {approximately}1000 ft from the northern margin of the FCAP to the crest of Chestnut Ridge, which has an elevation of {approximately}1100 ft above msl. The Sluice Channel Area is largely vegetated also. McCoy Branch runs from the top of Chestnut Ridge across the FCAP into Rogers Quarry and out of the quarry where it runs a short distance into Milton Hill Lake at McCoy Embayment, termed UMB. The portion south of Rogers Quarry, within Chestnut Ridge OU 4, is termed Lower McCoy Branch. The DOE Oak Ridge Y-12 Plant disposed of coal ash from its steam plant operations as a slurry that was discharged into an ash retention impoundment; this impoundment is the FCAP. The FCAP was built in 1955 to serve as a settling basin after coal ash slurried over Chestnut Ridge from the Y-12 Plant. The FCAP was constructed by building an earthen dam across the northern tributary of McCoy Branch. The dam was designed to hold 20 years of Y-12 steam plant ash. By July 1967, ash had filled up the impoundment storage behind the dam to within 4 ft of the top.

  18. Combined impurity gettering and defect passivation in polycrystalline silicon solar cells

    SciTech Connect (OSTI)

    Verhoef, L.A.; Michiels, P.; Sinke, W.C. ); Denisse, C.M.M.; Hendriks, M. ); van Zolingen, R.J.C. )

    1990-12-17

    Polycrystalline silicon wafers have been subjected to annealing (700 {degree}C, 1 h) and to a hydrogen plasma (350 {degree}C, 30 min) during the processing of solar cells. The annealing treatment enhances the bulk minority-carrier recombination lifetime by 19%, presumably by impurity gettering. The plasma treatment improves the lifetime by 26%; hydrogen passivation accounts for at least 2/3 of this improvement. Gettering and passivation are found to be complementary: application of both treatments results in a 43% increase in lifetime compared to standard.

  19. Effect of helium growth and carbon impurities on the properties of aged metal tritides

    SciTech Connect (OSTI)

    McConville, G.T.; Menke, D.A.; West, D.; Woods, C.M.

    1995-10-01

    The interaction of tritium with metals is made complex by two phenomena. The beta decay in the metal produces {sup 3}He. The helium moves to form bubbles. We shall show that the growth of the bubbles produces a two stage swelling of the metal coming first from the appearance of the helium and second from the relaxation of the lattice disorder caused by the bubble growth. The second phenomenon is the steady state ion and free radical concentration in the tritium over gas which interacts with impurities on the metal surface. We shall show that the reaction rates are much faster than for normal hydrogen cleaning. 12 refs., 7 figs., 3 tabs.

  20. Spectroscopic Measurement System for ITER Divertor Plasma: Impurity Influx Monitor (divertor)

    SciTech Connect (OSTI)

    Sugie, Tatsuo; Ogawa, Hiroaki; Kusama, Yoshinori; Kasai, Satoshi

    2008-03-12

    The detailed design of the Impurity Influx Monitor (divertor) has been carried out to provide the measurement capability in the harsh environment such as higher irradiation levels of neutron, gamma-ray and particles than in present devices. The in-situ calibration system using a micro retro-reflector array has been developed to monitor the sensitivity change of the optical system due to the environmental effects. The optical alignment system for the Monitor has been developed by using a dedicated optics for alignment in the collection optics for measurement.

  1. Passivation of an isoelectronic impurity by atomic hydrogen: The case of ZnTe:O

    SciTech Connect (OSTI)

    Felici, Marco; Polimeni, Antonio; Capizzi, Mario; Nabetani, Y.; Okuno, T.; Aoki, K.; Kato, T.; Matsumoto, T.; Hirai, T.

    2006-03-06

    We investigated the optical properties of ZnTe:O/GaAs before and after atomic hydrogen irradiation. Oxygen incorporation gives rise to energy levels associated with single O atoms, O-O pairs, and O clusters, and to a blueshift of the energy gap of the material with respect to that of pure ZnTe/GaAs. All of these effects disappear progressively after irradiation with H, which also leads to an increase in the tensile strain of the epilayer. These observations provide experimental evidence of H-induced passivation of an isoelectronic impurity in II-VI alloys.

  2. Simultaneous recovery of vanadium and nickel from power plant fly-ash: Optimization of parameters using response surface methodology

    SciTech Connect (OSTI)

    Nazari, E.; Rashchi, F. Saba, M.; Mirazimi, S.M.J.

    2014-12-15

    Highlights: • Leaching of vanadium and nickel from fly ash (14.43% V and 5.19% Ni) in sulfuric acid was performed. • Optimization of leaching parameters was carried out using a response surface methodology. • Using optimum conditions, 94.28% V and 81.01% Ni “actual recovery” was obtained. - Abstract: Simultaneous recovery of vanadium (V) and nickel (Ni), which are classified as two of the most hazardous metal species from power plant heavy fuel fly-ash, was studied using a hydrometallurgical process consisting of acid leaching using sulfuric acid. Leaching parameters were investigated and optimized in order to maximize the recovery of both vanadium and nickel. The independent leaching parameters investigated were liquid to solid ratio (S/L) (5–12.5 wt.%), temperature (45–80 °C), sulfuric acid concentration (5–25 v/v%) and leaching time (1–5 h). Response surface methodology (RSM) was used to optimize the process parameters. The most effective parameter on the recovery of both elements was found to be temperature and the least effective was time for V and acid concentration for Ni. Based on the results, optimum condition for metals recovery (actual recovery of ca.94% for V and 81% for Ni) was determined to be solid to liquid ratio of 9.15 wt.%, temperature of 80 °C, sulfuric acid concentration of 19.47 v/v% and leaching time of 2 h. The maximum V and Ni predicted recovery of 91.34% and 80.26% was achieved.

  3. A Probabilistic Approach to Site-Specific, Hazard-Consistent

    Office of Environmental Management (EM)

    Vertical-to-Horizontal Spectral Ratio Model | Department of Energy Approach to Site-Specific, Hazard-Consistent Vertical-to-Horizontal Spectral Ratio Model A Probabilistic Approach to Site-Specific, Hazard-Consistent Vertical-to-Horizontal Spectral Ratio Model A Probabilistic Approach to Site-Specific, Hazard-Consistent Vertical-to-Horizontal Spectral Ratio Model Rizzo Associates Presented at U.S. DOE Natural Phenomena Hazards Meeting October 21, 2014 A Probabilistic Approach to

  4. Self-consistent second-order Green's function perturbation theory...

    Office of Scientific and Technical Information (OSTI)

    Self-consistent second-order Green's function perturbation theory for periodic systems ... Sponsoring Org: USDOE Country of Publication: United States Language: English Word Cloud ...

  5. California Department of Fish and Wildlife Consistency Determination...

    Open Energy Info (EERE)

    California Department of Fish and Wildlife Consistency Determination Webpage Jump to: navigation, search OpenEI Reference LibraryAdd to library Web Site: California Department of...

  6. A consistent second order projection scheme for simulating transient...

    Office of Scientific and Technical Information (OSTI)

    flow with Smoothed Particle Hydrodynamics. Citation Details In-Document Search Title: A consistent second order projection scheme for simulating transient viscous flow with ...

  7. Efficient self-consistent quantum transport simulator for quantum...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Efficient self-consistent quantum transport simulator for quantum ... DOE Contract Number: DE-AC04-94AL85000 Resource Type: Journal Article Resource Relation: ...

  8. The correlation between reactivity and ash mineralogy of coke

    SciTech Connect (OSTI)

    Kerkkonen, O.; Mattila, E.; Heiniemi, R.

    1996-12-31

    Rautaruukki is a modern integrated Finnish steel works having a production of 2.4 mil. t/year of flat products. The total fuel consumption of the two blast furnaces in 1994 was 435 kg/t HM. Coke used was 345 kg/t HM and oil injection was 90 kg/t HM. The coking plant was taken in to operation in 1987 and is the only one in Finland, which means that the coking tradition is very short. Coke production is 0.9 mil. t/year. The coking blends include 70--80% medium volatile coals having a wide range of total dilatation. From time to time disturbances in the operation of the blast furnaces have occurred in spite of the fact that the reactivity of the coke used has remained constant or even decreased. It was thought necessary to investigate the factors affecting coke reactivity, in order to better understand the results of the reactivity test. This paper deals with carbonization tests done in a 7 kg test oven using nine individual coals having volatile-matter contents of 17--36% (dry) and seven blends made from these coals. Coke reactivity with CO{sub 2} at 1100 C (CRI) and coke strength after reaction (CSR) were determined using the test developed by the Nippon Steel Corporation. The influence of coke carbon form, porosity and especially ash mineralogy on the coke reactivity were examined. The effects of some additives; petroleum coke (pet coke), the spillage material from the coke ovens and oxidized coal, on coke quality were also studied. Typical inorganic minerals found in coals were added to one of the high volatile coals, which was then coked to determine the affect of the minerals on the properties of the coke produced.

  9. De-ashing of coal liquids with ceramic membrane microfiltration and diafiltration

    SciTech Connect (OSTI)

    Not Available

    1992-01-01

    Removal of mineral matter from liquid hydrocarbons derived from the direct liquefaction of coal is required for product acceptability. Current methods include critical solvent de-ashing and filtration, both of which produce an ash reject stream containing up to 15% of the liquid hydrocarbon product. This program is directed towards development of an improved process for de-ashing and recovery of coal-derived residual oil: the use of ceramic membranes for high-temperature microfiltration and diafiltration. Using laboratory-scale ceramic membrane modules, samples of a coal-derived residual oil containing ash will be processed by crossflow microfiltration, followed by solvent addition and refiltration (diafiltration). Recovery of de-ashed residual oil will be demonstrated. Data from this program will be used to develop a preliminary engineering design and cost estimate for a demonstration pilot plant incorporating full-scale membrane modules. In addition, estimates for production system capital and operating costs will be developed to assess process economic feasibility. The five program tasks include (1) ceramic membrane fabrication, (2) membrane test system assembly, (3) testing of the ceramic membranes, (4) design of a demonstration system using full scale membrane modules, and (5) development of estimates for microfiltration capital and operating costs and assessment of process economic feasibility.

  10. Investigation of MSWI fly ash melting characteristic by DSC-DTA

    SciTech Connect (OSTI)

    Li, Rundong Wang, Lei; Yang, Tianhua; Raninger, Bernhard

    2007-07-01

    The melting process of MSWI (Municipal Solid Waste Incineration) fly ash has been studied by high-temperature DSC-DTA experiments. The experiments were performed at a temperature range of 20-1450 deg. C, and the considerable variables included atmosphere (O{sub 2} and N{sub 2}), heating rates (5 deg. C/min, 10 deg. C/min, 20 deg. C/min) and CaO addition. Three main transitions were observed during the melting process of fly ash: dehydration, polymorphic transition and fusion, occurring in the temperature range of 100-200 deg. C, 480-670 deg. C and 1101-1244 deg. C, respectively. The apparent heat capacity and heat requirement for melting of MSWI fly ash were obtained by DSC (Differential Scanning Calorimeter). A thermodynamic modeling to predict the heat requirements for melting process has been presented, and it agrees well with the experimental data. Finally, a zero-order kinetic model of fly ash melting transition was established. The apparent activation energy of MSWI fly ash melting transition was obtained.

  11. Fly ash properties and mercury sorbent affect mercury release from curing concrete

    SciTech Connect (OSTI)

    Danold W. Golightly; Chin-Min Cheng; Linda K. Weavers; Harold W. Walker; William E. Wolfe

    2009-04-15

    The release of mercury from concrete containing fly ashes from various generator boilers and powdered activated carbon sorbent used to capture mercury was measured in laboratory experiments. Release of gaseous mercury from these concretes was less than 0.31% of the total quantity of mercury present. The observed gaseous emissions of mercury during the curing process demonstrated a dependency on the organic carbon content of the fly ash, with mercury release decreasing with increasing carbon content. Further, lower gaseous emissions of mercury were observed for concretes incorporating ash containing activated carbon sorbent than would be expected based on the observed association with organic carbon, suggesting that the powdered activated carbon more tightly binds the mercury as compared to unburned carbon in the ash. Following the initial 28-day curing interval, mercury release diminished with time. In separate leaching experiments, average mercury concentrations leached from fly ash concretes were less than 4.1 ng/L after 18 h and 7 days, demonstrating that less than 0.02% of the mercury was released during leaching. 25 refs., 4 figs., 5 tabs.

  12. Coal Fly Ash as a Source of Iron in Atmospheric Dust

    SciTech Connect (OSTI)

    Chen, Haihan; Laskin, Alexander; Baltrusaitis, Jonas; Gorski, Christopher A.; Scherer, Michelle; Grassian, Vicki H.

    2012-01-18

    Anthropogenic coal fly ash aerosols may represent a significant source of bioavailable iron in the open ocean. Few measurements have been made to compare the solubility of atmospheric iron from anthropogenic aerosols and other sources. We report an investigation of the iron dissolution of three fly ash samples in acidic aqueous solutions and compare the solubilities with that of Arizona test dust, a reference material of mineral dust. The effects of pH, cloud processing, and solar irradiation on Fe solubility were explored. Similar to previously reported results on mineral dust, iron in aluminosilicate phases provide predominant dissolved iron compared with iron in oxides. Iron solubility of fly ash is higher than Arizona test dust, especially at the higher pH conditions investigated. Simulated atmospheric processing elevates iron solubility due to significant changes in the morphology aluminosilicate glass, a dominantly material in fly ash particle. Iron continuously releases into the aqueous solution as fly ash particles break up into smaller fragments. The assessment of dissolved atmospheric iron deposition fluxes, and their effect on the biogeochemistry at ocean surface should be constrained by taking into account the source, environment pH, Fe speciation, and solar radiation.

  13. Thermal behavior of spiral fin-and-tube heat exchanger having fly ash deposit

    SciTech Connect (OSTI)

    Nuntaphan, Atipoang; Kiatsiriroat, Tanongkiat

    2007-08-15

    This research investigates the effect of fly-ash deposit on thermal performance of a cross-flow heat exchanger having a set of spiral finned-tubes as a heat transfer surface. A stream of warm air having high content of fly-ash is exchanging heat with a cool water stream in the tubes. In this study, the temperature of the heat exchanger surface is lower than the dew point temperature of air, thus there is condensation of moisture in the air stream on the heat exchanger surface. The affecting parameters such as the fin spacing, the air mass flow rate, the fly-ash mass flow rate and the inlet temperature of warm air are varied while the volume flow rate and the inlet temperature of the cold water stream are kept constant at 10 l/min and 5 C, respectively. From the experiment, it is found that as the testing period is shorter than 8 h the thermal resistance due to the fouling increases with time. Moreover, the deposit of fly-ash on the heat transfer surface is directly proportional to the dust-air ratio and the amount of condensate on heat exchange surface. However, the deposit of fly-ash is inversely proportional to the fin spacing. The empirical model for evaluating the thermal resistance is also developed in this work and the simulated results agree well with those of the measured data. (author)

  14. Barley seedling growth in soils amended with fly ash or agricultural lime followed by acidification

    SciTech Connect (OSTI)

    Renken, R.R.; McCallister, D.L.; Tarkalson, D.D.; Hergert, G.W.; Marx, D.B.

    2006-05-15

    Calcium-rich coal combustion fly ash can be used as an amendment to neutralize soil acidity because of its oxides and carbonate content, but its aluminum content could inhibit plant growth if soil pH values fall below optimal agronomic levels. This study measured root and shoot growth of an acid-sensitive barley (Hordeum vulgare L. 'Kearney') grown in the greenhouse on three naturally acid soils. The soils were either untreated or amended with various liming materials (dry fly ash, wet fly ash, and agricultural lime) at application rates of 0, .5, 1, and 1.5 times the recommended lime requirement, then treated with dilute acid solutions to simulate management-induced acidification. Plant growth indexes were measured at 30 days after planting. Root mass per plant and root length per plant were greater for the limed treatments than in the acidified check. Root growth in the limed treatments did not differ from root growth in the original nonacidified soils. Top mass per plant in all limed soils was either larger than or not different from that in the original nonacidified soils. Based on top mass per plant, no liming material or application rate was clearly superior. Both fly ash and agricultural lime reduced the impact of subsequent acidification on young barley plants. Detrimental effects of aluminum release on plant growth were not observed. Calcium-rich fly ash at agronomic rates is an acceptable acid-neutralizing material with no apparent negative effects.

  15. Post-treatment of fly ash by ozone in a fixed bed reactor

    SciTech Connect (OSTI)

    Kim Hougaard Pedersen; Merc Casanovas Meli; Anker Degn Jensen; Kim Dam-Johansen

    2009-01-15

    The residual carbon in fly ash produced from pulverized coal combustion can adsorb the air-entraining admixtures (AEAs) added to enhance air entrainment in concrete. This behavior of the ash can be suppressed by exposing the fly ash to oxidizing species, which oxidizes the carbon surface and thus prevents the AEA to be adsorbed. In the present work, two fly ashes have been ozonated in a fixed bed reactor and the results showed that ozonation is a potential post-treatment method that can lower the AEA requirements of a fly ash up to 6 times. The kinetics of the carbon oxidation by ozone was found to be fast. A kinetic model has been formulated, describing the passivation of carbon, and it includes the stoichiometry of the ozone consumption (0.8 mol of O{sub 3}/kg of C) and an ineffective ozone loss caused by catalytic decomposition. The simulated results correlated well with the experimental data. 28 refs., 7 figs., 3 tabs.

  16. Performance evaluation of highway embankment constructed using coal ash. Final report

    SciTech Connect (OSTI)

    Alleman, J.E.; Fox, P.J.; De Battista, D.J.

    1996-12-01

    The objective of this project was to assess the environmental and geotechnical performance of two highway embankments constructed using coal combustion fly ash. The environmental work focused on characterizing monitoring well water samples from the site before, during, and after construction. In addition, a number of in-situ lysimeter water samples were also tested during and after construction. In each case, water samples were evaluated in terms of their constitutive organic and metal concentrations, as well as their relative bioassay response using a MicrotoxTM protocol. The geotechnical work included monitoring of ash water content and unit weight during placement, settlement analysis and in-situ testing of the completed as fills using the Standard Penetration Test. Analysis of the groundwater and lysimeter water samples indicated that the coal ash had not adversely affected the environmental quality of the 56th Street overpass site. The embankments also performed well from a geotechnical perspective both during and after construction. The only difficulty was the measurement of coal ash water content and unit weight using the nuclear density gauge. The benefits of reusing coal combustion fly ash for highway construction are: (1) low-cost source material for INDOT, (2) reduced disposal costs for Indiana utilities, and (3) savings of Indiana landfill capacity.

  17. Use of Brazilian sugarcane bagasse ash in concrete as sand replacement

    SciTech Connect (OSTI)

    Sales, Almir; Lima, Sofia Araujo

    2010-06-15

    Sugarcane today plays a major role in the worldwide economy, and Brazil is the leading producer of sugar and alcohol, which are important international commodities. The production process generates bagasse as a waste, which is used as fuel to stoke boilers that produce steam for electricity cogeneration. The final product of this burning is residual sugarcane bagasse ash (SBA), which is normally used as fertilizer in sugarcane plantations. Ash stands out among agroindustrial wastes because it results from energy generating processes. Many types of ash do not have hydraulic or pozzolanic reactivity, but can be used in civil construction as inert materials. The present study used ash collected from four sugar mills in the region of Sao Carlos, SP, Brazil, which is one of the world's largest producers of sugarcane. The ash samples were subjected to chemical characterization, sieve analysis, determination of specific gravity, X-ray diffraction, scanning electron microscopy, and solubilization and leaching tests. Mortars and concretes with SBA as sand replacement were produced and tests were carried out: compressive strength, tensile strength and elastic modulus. The results indicated that the SBA samples presented physical properties similar to those of natural sand. Several heavy metals were found in the SBA samples, indicating the need to restrict its use as a fertilizer. The mortars produced with SBA in place of sand showed better mechanical results than the reference samples. SBA can be used as a partial substitute of sand in concretes made with cement slag-modified Portland cement.

  18. Radon exhalation rate from coal ashes and building materials in Italy

    SciTech Connect (OSTI)

    Battaglia, A.; Capra, D.; Queirazza, G.

    1992-12-31

    The Italian National Electricity Board, in cooperation with Centro Informazioni Stubi Esperienze (CISE) has a program to assess the hazards connected with using fly ash in civil applications as partial substitutes for cement and other building materials. We investigated the natural radioactivity levels of more than 200 building materials. The survey involved materials available in Italy, categorized by geographical location and type of production. We also examined approximately 100 samples of fly ash from United States and South African coal, obtained from Italian power plants. Exhalation rates from about 40 powdered materials were determined by continuously measuring radon concentration growth in closed containers. Measurements were also performed on whole bricks, slabs, and titles. Details about the high-sensitivity measuring devices are presented. The influence of fly ash on exhalation rates was investigated by accurately measuring radon emanation from slabs with various ash/cement ratios and with slabs of inert materials having various radium concentrations. We will discuss results of forecasting indoor radon concentrations under different ventilation conditions. Two identical test rooms are being built, one with conventional and one with fly-ash building materials, to compare theoretical calculations with experimental data. Specifications for instruments to control and to measure the most important parameters are also discussed.

  19. Role of fly ash in the removal of organic pollutants from wastewater

    SciTech Connect (OSTI)

    M. Ahmaruzzaman

    2009-03-15

    Fly ash, a relatively abundant and inexpensive material, is currently being investigated as an adsorbent for the removal of various organic pollutants from wastewater. The wastewater contains various types of phenolic compounds, such as chloro, nitro, amino, and other substituted compounds. Various types of pesticides, such as lindane, malathion, carbofuran, etc., and dyes, such as, methylene blue, crystal violet, malachite green, etc., are also present in the wastewater. These contaminants pollute the water stream. These organic pollutants, such as phenolic compounds, pesticides, and dyes, etc., can be removed very effectively using fly ash as adsorbent. This article presents a detailed review on the role of fly ash in the removal of organic pollutants from wastewater. Adsorption of various pollutants using fly ash has been reviewed. The adsorption mechanism and other influencing factors, favorable conditions, and competitive ions, etc., on the adsorption process have also been discussed in this paper. It is evident from the review that fly ash has demonstrated good removal capabilities for various organic compounds. 171 refs., 3 figs., 5 tabs.

  20. Direct acid dissolution of aluminum and other metals from fly ash

    SciTech Connect (OSTI)

    Kelmers, A.D.; Egan, B.Z.; Seeley, F.G.; Campbell, G.D.

    1981-01-01

    Fly ash could provide a significant domestic source of alumina and thus supply a large part of the US needs for aluminum and possibly also several other metals. The aluminum and other metals can be solubilized from fly ash by acid dissolution methods. The aluminum may be present in any or all of three solid phases: (1) crystalline; (2) glassy amorphous; and (3) irregular, spongy amorphous. The chemistry of these phases controls the solubilization behavior. The aluminum in high-calcium western ashes is primarily found in the amorphous phases, and much of it can be solubilized by using short-time, ambient-temperature leaching. Little of the aluminum in the low-calcium eastern ashes is solubilized under ambient-temperature conditions, and only a portion can be solubilized even at reflux temperature conditions. Some of the aluminum in these eastern ashes is present as mullite, while some is found in the amorphous material. The fraction contained in mullite is relativey acid insoluble, and only partial solubilization can be achieved even under vigorous acid leach conditions.

  1. Performance of a palladium membrane reactor using a Ni catalyst for fusion fuel impurities processing

    SciTech Connect (OSTI)

    Willm, R.S. [Los Alamos National Lab., NM (United States); Okuno, K. [Japan Atomic Energy Research Inst., Ibaraki-ken (Japan)

    1994-12-31

    The palladium membrane reactor (PMR) provides a means to recover hydrogen isotopes from impurities expected to be present in fusion reactor exhaust. This recovery is based on reactions such as water gas shift and steam reforming for which conversion is equilibrium limited. By including a selectively permeable membrane such as Pd/Ag in the catalyst bed, hydrogen isotopes can be removed from the reacting environment, thus promoting the reaction to complete conversion. Such a device has been built and operated at the Tritium Systems Test Assembly (TSTA) at Los Alamos National Laboratory (LANL). For the reactions listed above, earlier study with this unit has shown that hydrogen single-pass recoveries approaching 100% can be achieved. It was also determined that a nickel catalyst is a feasible choice for use with a PMR appropriate for fusion fuel impurities processing. The purpose of this study is to systematically assess the performance of the PMR using a nickel catalyst. Reactions which will be studied include the water gas shift reaction, steam reforming and methane cracking. Extended operation will be performed to detect performance degradation if it exists. The use of methane in these tests may lead to the formation of coke on the catalyst. Methods of removing the coke such as treatment with carbon dioxide or diluted oxygen will be examined.

  2. Performance of a palladium membrane reactor using a Ni catalyst for fusion fuel impurities processing

    SciTech Connect (OSTI)

    Willms, R.S.; Wilhelm, R. [Los Alamos National Lab., NM (United States); Okuno, K. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan)

    1994-07-01

    The palladium membrane reactor (PNM) provides a means to recover hydrogen isotopes from impurities expected to be present in fusion reactor exhaust. This recovery is based on reactions such as water-gas shift and steam reforming for which conversion is equilibrium limited. By including a selectively permeable membrane such as Pd/Ag in the catalyst bed, hydrogen isotopes can be removed from the reacting environment, thus promoting the reaction to complete conversion. Such a device has been built and operated at the Tritium Systems Test Assembly (TSTA) at Los Alamos National Laboratory (LANL). For the reactions listed above, earlier study with this unit has shown that hydrogen single-pass recoveries approaching 100% can be achieved. It was also determined that a nickel catalyst is a feasible choice for use with a PMR appropriate for fusion fuel impurities processing. The purpose of this study was to systematically assess the performance of the PMR using a nickel catalyst over a range of temperatures, feed compositions and flowrates. Reactions which were studied are the water-gas shift reaction and steam reforming.

  3. Finite-size effects in a metallic multichannel ring with Kondo impurity: Persistent currents and magnetoresistance

    SciTech Connect (OSTI)

    Zvyagin, A.A.; Schlottmann, P.

    1996-12-01

    We consider a spin-1/2 impurity interacting with conduction electrons in two different orbital channels via an isotropic spin exchange. The exchange is the same for both channels, but a crystalline field breaks the symmetry between the orbital channels. This corresponds to a splitting of the conduction electron {Gamma}{sub 8} into two doublets in the quadrupolar Kondo effect, or to the electron-assisted tunneling of an atom in a double-well potential in an external magnetic field. Another possible realization could be a quantum dot coupled to two equal rings of the same length subject to an electrostatic potential difference. We consider the Bethe ansatz equations for this model and derive the tower structure of the finite-size corrections to the ground-state energy. These results are used to discuss the Aharonov-Bohm-Casher interference pattern in the persistent charge and spin currents, and the magnetoresistivity due to the scattering of electrons off the impurity. {copyright} {ital 1996 The American Physical Society.}

  4. GaAs Blocked-Impurity-Band Detectors for Far-Infrared Astronomy

    SciTech Connect (OSTI)

    Cardozo, Benjamin Lewin

    2004-12-21

    High-purity and doped GaAs films have been grown by Liquid-phase epitaxy (LPE) for development of a blocked impurity band (BIB) detector for far-infrared radiation. The film growth process developed has resulted in the capability to grow GaAs with a net active impurity concentration below 1 x 10{sup 13} cm{sup -3}, ideal for the blocking layer of the BIB detector. The growth of n-type LPE GaAs films with donor concentrations below the metal-insulator transition, as required for the absorbing layer of a BIB detector, has been achieved. The control of the donor concentration, however, was found to be insufficient for detector production. The growth by LPE of a high-purity film onto a commercially grown vapor-phase epitaxial (VPE) n-type GaAs doped absorbing layer resulted in a BIB device that showed a significant reduction in the low-temperature dark current compared to the absorbing layer only. Extended optical response was not detected, most likely due to the high compensation of the commercially grown GaAs absorbing layer, which restricts the depletion width of the device.

  5. Impurities, temperature, and density in a miniature electrostatic plasma and current source

    SciTech Connect (OSTI)

    Den Hartog, D.J.; Craig, D.J.; Fiksel, G.; Sarff, J.S.

    1996-10-01

    We have spectroscopically investigated the Sterling Scientific miniature electrostatic plasma source-a plasma gun. This gun is a clean source of high density (10{sup 19} - 10{sup 20} m{sup -3}), low temperature (5 - 15 eV) plasma. A key result of our investigation is that molybdenum from the gun electrodes is largely trapped in the internal gun discharge; only a small amount escapes in the plasma flowing out of the gun. In addition, the gun plasma parameters actually improve (even lower impurity contamination and higher ion temperature) when up to 1 kA of electron current is extracted from the gun via the application of an external bias. This improvement occurs because the internal gun anode no longer acts as the current return for the internal gun discharge. The gun plasma is a virtual plasma electrode capable of sourcing an electron emission current density of 1 kA/cm{sup 2}. The high emission current, small size (3 - 4 cm diameter), and low impurity generation make this gun attractive for a variety of fusion and plasma technology applications.

  6. A fast spectroscopic diagnostic for the measurement of plasma impurity ion dynamics

    SciTech Connect (OSTI)

    Den Hartog, D.J.; Fonck, R.J.

    1994-04-01

    A high-resolution spectrometer has been developed and used to measure simultaneously impurity ion temperature and flow velocities in high temperature plasmas with 10 {mu}s temporal resolution (limited by digitization rate). This device is actually a duo-spectrometer: measurements from two different chordal views of the plasma can be made simultaneously via two separate quartz input fiber optic bundles coupled to the entrance slits which are tilted to compensate for line curvature. The dispersed spectra on the exit plane of the duo-spectrometer are coupled via quartz fiber optics to two arrays of 16 photomultiplier tubes each. Measurement made by recording the Doppler broadened and shifted 227.091 nm emission from the CV impurity ions in the MST reversed-field pinch (RFP) plasma have achieved precisions of <6 eV for temperatures of 150 Ev and <0.7 km/s for flow velocities of 6 km/s. Representative results from the MsT RFP indicate that the toroidal flow velocity drops and ion temperature increases during saw tooth events in MST.

  7. High-Pressure Turbulent Flame Speeds and Chemical Kinetics of Syngas Blends with and without Impurities

    SciTech Connect (OSTI)

    Peterson, Eric; Mathieu, Olivier; Morones, Anibal; Ravi, Sankar; Keesee, Charles; Hargis, Joshua; Vivanco, Jose

    2014-12-01

    This Topical Report documents the first year of the project, from October 1, 2013 through September 30, 2014. Efforts for this project included experiments to characterize the atmospheric-pressure turbulent flame speed vessel over a range of operating conditions (fan speeds and turbulent length scales). To this end, a new LDV system was acquired and set up for the detailed characterization of the turbulence field. Much progress was made in the area of impurity kinetics, which included a numerical study of the effect of impurities such as NO2, NO, H2S, and NH3 on ignition delay times and laminar flame speeds of syngas blends at engine conditions. Experiments included a series of laminar flame speed measurements for syngas (CO/H2) blends with various levels of CH4 and C2H6 addition, and the results were compared to the chemical kinetics model of NUI Galway. Also, a final NOx kinetics mechanism including ammonia was assembled, and a journal paper was written and is now in press. Overall, three journal papers and six conference papers related to this project were published this year. Finally, much progress was made on the design of the new high-pressure turbulent flame speed facility. An overall design that includes a venting system was decided upon, and the detailed design is in progress.

  8. The influence of impurity and particle control on TMX-U (Tandem Mirror Experiment Upgrade) plasma operation

    SciTech Connect (OSTI)

    Allen, S.L.; Yu, T.L.; Foote, J.H.; Pickles, W.L.

    1985-11-01

    A variety of techniques are used in TMX-U to control impurities and reflux: repeated plasma pulses, glow discharge cleaning (GDC), and gettering. A series of experiments under three different plasma-wall conditions was performed: no wall conditioning after a machine maintenance cycle, a glow-discharge-cleaned wall, and a gettered wall. Several plasma diagnostics to determine the effect of these procedures on TMX-U plasma parameters were used. Spectroscopic measurements indicated that GDC reduced impurities and increased the electron temperature, enabling full-duration beam-sustained plasma operation without a large number of repeated plasma pulses. Gettering further reduced the impurities and the neutral pressure, and this improved condition persisted for several shots after gettering was stopped. Measurements from residual gas analyzers and an end-loss ion spectrometer indicated that hydrogen is present in the plasma during the initial deuterium operation after pumpdown; the hydrogen level decreased after plasma operation with gettering, indicating reduced wall recycling.

  9. Formation of a regular domain structure in TGS–TGS + Cr crystals with a profile impurity distribution

    SciTech Connect (OSTI)

    Belugina, N. V. Gainutdinov, R. V.; Tolstikhina, A. L.; Ivanova, E. S.; Kashevich, I. F.; Shut, V. N.; Mozzharov, S. E.

    2015-07-15

    A complex investigation of TGS–TGS + Cr crystals with a profile impurity distribution of chromium ions Cr{sup 3+} has been carried out at the macrolevel (measurement of dielectric properties by the method of nematic liquid crystals) and microlevel (domain structure according to atomic force microscopy data). It is established that periodic doped layers are formed only in individual growth pyramids in the regions where the polarization vector has a nonzero component along the normal to the growth faces rather than throughout the entire crystal volume. The domain configuration at the boundary of growth layers with different impurity compositions has been studied by piezoelectric force microscopy. The static unipolarity of layers with and without chromium impurity is approximately identical, whereas the domain-wall density in doped regions is higher than that in undoped ones by a factor of about 7.

  10. Hydration mechanisms of ternary Portland cements containing limestone powder and fly ash

    SciTech Connect (OSTI)

    De Weerdt, K.; Haha, M. Ben; Le Saout, G.; Kjellsen, K.O.; Justnes, H.; Lothenbach, B.

    2011-03-15

    The effect of minor additions of limestone powder on the properties of fly ash blended cements was investigated in this study using isothermal calorimetry, thermogravimetry (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM) techniques, and pore solution analysis. The presence of limestone powder led to the formation of hemi- and monocarbonate and to a stabilisation of ettringite compared to the limestone-free cements, where a part of the ettringite converted to monosulphate. Thus, the presence of 5% of limestone led to an increase of the volume of the hydrates, as visible in the increase in chemical shrinkage, and an increase in compressive strength. This effect was amplified for the fly ash/limestone blended cements due to the additional alumina provided by the fly ash reaction.

  11. Fly ash leachate generation and qualitative trends at Ohio test sites

    SciTech Connect (OSTI)

    Solc, J.; Foster, H.J.; Butler, R.D.

    1995-12-01

    Under the sponsorship of the U.S. Department of Energy, the environmental impact and potential contamination from landfilled fly ash (coal conversion solid residues - CCSRs) have been studied at field sites in Ohio. The progressive increase of moisture content within pilot cells over depth and time facilitated intensive chemical processes and generation of highly alkaline (pH of 10 to 12) leachate. Chemistry of pore water from lysimeters and ASTM leachate from fly ash and soil cores indicate the leachate potential to migrate out of deposit and impact the pore water quality of surrounding soils. Na, SO{sub 4} and, particularly, K, Cl, pH, and EC appeared to be valuable indicator parameters for tracking potential leachate transport both within the cells and below the ash/soil interface.

  12. Steam plant ash disposal facility and industrial landfill at the Y-12 Plant, Anderson County, Tennessee

    SciTech Connect (OSTI)

    Not Available

    1992-02-01

    The US Department of Energy (DOE) is proposing to install a wet ash handling system to dewater bottom ash from the coal-fired steam plant at its Y-12 Plant and to construct a new landfill for disposal of industrial wastes, including the dewatered bottom ash. The DOE operates three major facilities on its Oak Ridge Reservation (ORR). Operation of these facilities results in the production of a variety of nonhazardous, nonradioactive solid wastes (approximately 300 m{sup 3} per day, compacted) including sanitary wastes, common industrial wastes and construction debris. At the current rate of use, this existing landfill will be filled within approximately 18 months, and more space is urgently needed. In an effort to alleviate this problem, DOE and WMD management propose to create additional landfill facilities at a nearby site. The potential environmental impacts associated with this proposed action are the subject of this environmental assessment (EA).

  13. Fly ash from Texas lignite and western subbituminous coal: a comparative characterization

    SciTech Connect (OSTI)

    Sears, D. R.; Benson, S. A.; McCollor, D. P.; Miller, S. J.

    1982-01-01

    As examples, we use two Jackson group lignites from Atascosa and Fayette Counties, Texas, and a Green River Region subbituminous coal from Routt County, Colorado. The composition of individual fly ash particles was determined using scanning electron microscopy and electron microprobe, with support from x-ray diffraction of bulk ash. Using particle sample populations large enough to permit statistical treatment, we describe the relationship of composition to particle size and the correlation between elemental concentrations, as well as particle size and composition distributions. Correlations are displayed as data maps which show the complete range of observed variation among these parameters, emphasizing the importance of coal variability. We next use this data to produce a population distribution of ash particle resistivities calculated with Bickelhaupt's model. The relationship between calculated resistivity and particle size is also displayed, and the results are compared with measured values. 7 figures.

  14. BILIWG: Consistent "Figures of Merit" (Presentation)

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

    BILIWG: Consistent "Figures of Merit" A finite set of results reported in consistent units * To track progress of individual projects on a consistent basis * To enable comparing projects in a transparent manner Potential BILIWG Figures of Merit Key BILI Distributed Reforming Targets * Cost ($/kg of H2): H2A analysis - Distributed reforming station,1000 kg/day ave./daily dispensed, 5000/6250 psi (and 10,000/12,000 psi) dispensing, 500 units/yr. * nth unit vs. 500 units/yr ? * production

  15. Influences of chemical activators on incinerator bottom ash

    SciTech Connect (OSTI)

    Qiao, X.C. Cheeseman, C.R.; Poon, C.S.

    2009-02-15

    This research has applied different chemical activators to mechanically and thermally treated fine fraction (<14 mm) of incinerator bottom ash (IBA), in order to investigate the influences of chemical activators on this new pozzolanic material. IBA has been milled and thermally treated at 800 deg. C (TIBA). The TIBA produced was blended with Ca(OH){sub 2} and evaluated for setting time, reactivity and compressive strength after the addition of 0.0565 mole of Na{sub 2}SO{sub 4}, K{sub 2}SO{sub 4}, Na{sub 2}CO{sub 3}, K{sub 2}CO{sub 3}, NaOH, KOH and CaCl{sub 2} into 100 g of binder (TIBA+Ca(OH){sub 2}). The microstructures of activated IBA and hydrated samples have been characterized by X-ray diffraction (XRD) and thermogravimetry (TG) analysis. Thermal treatment is found to produce gehlenite (Ca{sub 2}Al{sub 2}SiO{sub 7}), wollastonite (CaSiO{sub 3}) and mayenite (Ca{sub 12}Al{sub 14}O{sub 33}) phases. The thermally treated IBA samples are significantly more reactive than the milled IBA. The addition of Na{sub 2}CO{sub 3} can increase the compressive strength and calcium hydroxide consumption at 28-day curing ages. However, the addition of Na{sub 2}SO{sub 4}, K{sub 2}SO{sub 4}, K{sub 2}CO{sub 3}, NaOH and KOH reduces the strength and hydration reaction. Moreover, these chemicals produce more porous samples due to increased generation of hydrogen gas. The addition of CaCl{sub 2} has a negative effect on the hydration of TIBA samples. Calcium aluminium oxide carbonate sulphide hydrate (Ca{sub 4}Al{sub 2}O{sub 6}(CO{sub 3}){sub 0.67}(SO{sub 3}){sub 0.33}(H{sub 2}O){sub 11}) is the main hydration product in the samples with activated IBA, except for the sample containing CaCl{sub 2}.

  16. Computation of probabilistic hazard maps and source parameter estimation for volcanic ash transport and dispersion

    SciTech Connect (OSTI)

    Madankan, R.; Pouget, S.; Singla, P.; Bursik, M.; Dehn, J.; Jones, M.; Patra, A.; Pavolonis, M.; Pitman, E.B.; Singh, T.; Webley, P.

    2014-08-15

    Volcanic ash advisory centers are charged with forecasting the movement of volcanic ash plumes, for aviation, health and safety preparation. Deterministic mathematical equations model the advection and dispersion of these plumes. However initial plume conditions height, profile of particle location, volcanic vent parameters are known only approximately at best, and other features of the governing system such as the windfield are stochastic. These uncertainties make forecasting plume motion difficult. As a result of these uncertainties, ash advisories based on a deterministic approach tend to be conservative, and many times over/under estimate the extent of a plume. This paper presents an end-to-end framework for generating a probabilistic approach to ash plume forecasting. This framework uses an ensemble of solutions, guided by Conjugate Unscented Transform (CUT) method for evaluating expectation integrals. This ensemble is used to construct a polynomial chaos expansion that can be sampled cheaply, to provide a probabilistic model forecast. The CUT method is then combined with a minimum variance condition, to provide a full posterior pdf of the uncertain source parameters, based on observed satellite imagery. The April 2010 eruption of the Eyjafjallajkull volcano in Iceland is employed as a test example. The puff advection/dispersion model is used to hindcast the motion of the ash plume through time, concentrating on the period 1416 April 2010. Variability in the height and particle loading of that eruption is introduced through a volcano column model called bent. Output uncertainty due to the assumed uncertain input parameter probability distributions, and a probabilistic spatial-temporal estimate of ash presence are computed.

  17. Heavy metal leaching from coal fly ash amended container substrates during Syngonium production

    SciTech Connect (OSTI)

    Li, Q.S.; Chen, J.J.; Li, Y.C.

    2008-02-15

    Coal fly ash has been proposed to be an alternative to lime amendment and a nutrient source of container substrates for ornamental plant production. A great concern over this proposed beneficial use, however, is the potential contamination of surface and ground water by heavy metals. In this study, three fly ashes collected from Florida, Michigan, and North Carolina and a commercial dolomite were amended in a basal substrate. The formulated substrates were used to produce Syngonium podophyllum Schott 'Berry Allusion' in 15-cm diameter containers in a shaded greenhouse. Leachates from the containers were collected during the entire six months of plant production and analyzed for heavy metal concentrations. There were no detectable As, Cr, Hg, Pb, and Se in the leachates; Cd and Mo were only detected in few leachate samples. The metals constantly detected were Cu, Mn, Ni, and Zn. The total amounts of Cu, Mn, Ni, and Zn leached during the six-month production period were 95, 210, 44, and 337 {mu} g per container, indicating that such amounts in leachates may contribute little to contamination of surface and ground water. In addition, plant growth indices and fresh and dry weights of S. podophyllum 'Berry Allusion' produced from fly ash and dolomite-amended substrates were comparable except for the plants produced from the substrate amended with fly ash collected from Michigan which had reduced growth indices and fresh and dry weights. Thus, selected fly ashes can be alternatives to commercial dolomites as amendments to container substrates for ornamental plant production. The use of fly ashes as container substrate amendments should represent a new market for the beneficial use of this coal combustion byproduct.

  18. Guidelines for control and prevention of fly ash erosion in fossil fired power plants. Final report

    SciTech Connect (OSTI)

    Drennen, J.F.; Kratina, P.

    1994-02-01

    Boiler tube failures (BTF`s) due to fly ash erosion are one of the leading single causes of availability loss in fossil boilers. The damage, which can be very localized, has led to expensive and lengthy forced outages. As part of an overall BTF reduction program, EPRI has documented the available solutions being applied for fly ash erosion. Unfortunately, most of these are regarded as temporary fixes that do not provide long term solutions. A technique applied in Canadian and Australian utilities has provided long term solutions on the order of ten years. This technique has been demonstrated now at two US utilities under an EPRI sponsored project, (RP2711-2). The result of the project is a guideline that outlines, step-by-step, activities for stepping up and running an erosion control program at a utility boiler. The heart of the program is the cold air velocity test (CAVT), done in the convective pass at ambient conditions. With the fans running, one or more two-man teams measure gas flows entering and/or leaving pendants and banks. These data and a boiler assessment are used to identify operating conditions conducive to fly ash erosion. Flow control screens are then selected and installed to redistribute fly ash, reduce gas velocities and produce acceptable erosion rates. The result should be long term relief from boiler tube failures caused by fly ash erosion. The program cost is estimated to be $300--$400/MW depending on unit design, operating characteristics and extent of fly ash erosion.

  19. Sulfur capture by oil shale ashes under atmospheric and pressurized FBC conditions

    SciTech Connect (OSTI)

    Yrjas, K.P.; Hupa, M. [Aabo Akademi Univ., Turku (Finland). Dept. of Chemical Engineering; Kuelaots, I.; Ots, A. [Tallinn Technical Univ. (Estonia). Thermal Engineering Dept.

    1995-12-31

    When oil shale contains large quantities of limestone, a significant auto-absorption of sulfur is possible under suitable conditions. The sulfur capture by oil shale ashes has been studied using a pressurized thermogravimetric apparatus. The chosen experimental conditions were typical for atmospheric and pressurized fluidized bed combustion. The Ca/S molar ratios in the two oil shales studied were 8 (Estonian) and 10 (Israeli). The samples were first burned in a gas atmosphere containing O{sub 2} and N{sub 2} (and CO{sub 2} if pressurized). After the combustion step, SO{sub 2} was added and sulfation started. The results with the oil shales were compared to those obtained with an oil shale cyclone ash from the Narva power plant in Estonia. In general, the results from the sulfur capture experiments under both atmospheric and pressurized conditions showed that the oil shale cannot only capture its own sulfur but also significant amounts of additional sulfur of another fuel if the fuels are mixed together. For example from the runs at atmospheric pressure, the conversion of CaO to CaSO{sub 4} was about 70% for Israeli oil shale and about 55% for Estonian oil shale (850 C). For the cyclone ash the corresponding conversion was about 20%. In comparison it could be mentioned that under the same conditions the conversions of natural limestones are about 30%. The reason the cyclone ash was a poor sulfur absorbent was probably due to its temperature history. In Narva the oil shale was burned at a significantly higher temperature (1,400 C) than was used in the experiments (750 C and 850 C). This caused the ash to sinter and the reactive surface area of the cyclone ash was therefore decreased.

  20. Synthesis of mesoporous silica materials from municipal solid waste incinerator bottom ash

    SciTech Connect (OSTI)

    Liu, Zhen-Shu Li, Wen-Kai; Huang, Chun-Yi

    2014-05-01

    Highlights: The optimal alkaline agent for the extraction of silica from bottom ash was Na{sub 2}CO{sub 3}. The pore sizes for the mesoporous silica synthesized from bottom ash were 23.8 nm. The synthesized materials exhibited a hexagonal pore structure with a smaller order. The materials have potential for the removal of heavy metals from aqueous solutions. - Abstract: Incinerator bottom ash contains a large amount of silica and can hence be used as a silica source for the synthesis of mesoporous silica materials. In this study, the conditions for alkaline fusion to extract silica from incinerator bottom ash were investigated, and the resulting supernatant solution was used as the silica source for synthesizing mesoporous silica materials. The physical and chemical characteristics of the mesoporous silica materials were analyzed using BET, XRD, FTIR, SEM, and solid-state NMR. The results indicated that the BET surface area and pore size distribution of the synthesized silica materials were 992 m{sup 2}/g and 23.8 nm, respectively. The XRD patterns showed that the synthesized materials exhibited a hexagonal pore structure with a smaller order. The NMR spectra of the synthesized materials exhibited three peaks, corresponding to Q{sup 2} [Si(OSi){sub 2}(OH){sub 2}], Q{sup 3} [Si(OSi){sub 3}(OH)], and Q{sup 4} [Si(OSi){sub 4}]. The FTIR spectra confirmed the existence of a surface hydroxyl group and the occurrence of symmetric SiO stretching. Thus, mesoporous silica was successfully synthesized from incinerator bottom ash. Finally, the effectiveness of the synthesized silica in removing heavy metals (Pb{sup 2+}, Cu{sup 2+}, Cd{sup 2+}, and Cr{sup 2+}) from aqueous solutions was also determined. The results showed that the silica materials synthesized from incinerator bottom ash have potential for use as an adsorbent for the removal of heavy metals from aqueous solutions.

  1. Self-consistency tests of large-scale dynamics parameterizations...

    Office of Scientific and Technical Information (OSTI)

    In self-consistency tests based on radiative-convective equilibrium (RCE; i.e., no large-scale convergence), we find that simulations either weakly coupled or strongly coupled to ...

  2. Parallel transport studies of high-Z impurities in the core of Alcator C-Mod plasmas

    SciTech Connect (OSTI)

    Reinke, M. L.; Hutchinson, I. H.; Rice, J. E.; Greenwald, M.; Howard, N. T.; Hubbard, A.; Hughes, J. W.; Terry, J. L.; Wolfe, S. M. [MIT-Plasma Science and Fusion Center Cambridge, Massachusetts 02139 (United States)] [MIT-Plasma Science and Fusion Center Cambridge, Massachusetts 02139 (United States)

    2013-05-15

    Measurements of poloidal variation, {sub z}/, in high-Z impurity density have been made using photodiode arrays sensitive to vacuum ultraviolet and soft x-ray emission in Alcator C-Mod plasmas. In/out asymmetries in the range of ?0.2<0.3 are observed for r/a<0.8, and accumulation on both the high-field side, n{sub z,cos}<0, and low-field side, n{sub z,cos}>0, of a flux surface is found to be well described by a combination of centrifugal, poloidal electric field, and ion-impurity friction effects. Up/down asymmetries, ?0.05<0.10, are observed over 0.50 corresponding to accumulation opposite the ion ?B drift direction. Measurements of the up/down asymmetry of molybdenum are found to disagree with predictions from recent neoclassical theory in the trace limit, n{sub z}Z{sup 2}/n{sub i}?1. Non-trace levels of impurities are expected to modify the main-ion poloidal flow and thus change friction-driven impurity density asymmetries and impurity poloidal rotation, v{sub ?,z}. Artificially modifying main-ion flow in parallel transport simulations is shown to impact both {sub z}/ and v{sub ?,z}, but simultaneous agreement between measured and predicted up/down and in/out asymmetry as well as impurity poloidal rotation is not possible for these C-Mod data. This link between poloidal flow and poloidal impurity density variation outlines a more stringent test for parallel neoclassical transport theory than has previously been performed. Measurement and computational techniques specific to the study of poloidal impurity asymmetry physics are discussed as well.

  3. Refinement of procedures for analysis and construction of hydraulicked ash-slag dumps to improve their in-service safety

    SciTech Connect (OSTI)

    Frolov, A. N.

    2013-03-15

    Solutions are proposed for enhancement of the in-service safety of hydraulicked ash-slag dumps with consideration of their hydrothermal regime. An assessment is given for the minimum dimensions of the settling basins and top surface of ash-slag dumps.

  4. Consistent description of kinetics and hydrodynamics of dusty plasma

    SciTech Connect (OSTI)

    Markiv, B.; Tokarchuk, M.; National University Lviv Polytechnic, 12 Bandera St., 79013 Lviv

    2014-02-15

    A consistent statistical description of kinetics and hydrodynamics of dusty plasma is proposed based on the Zubarev nonequilibrium statistical operator method. For the case of partial dynamics, the nonequilibrium statistical operator and the generalized transport equations for a consistent description of kinetics of dust particles and hydrodynamics of electrons, ions, and neutral atoms are obtained. In the approximation of weakly nonequilibrium process, a spectrum of collective excitations of dusty plasma is investigated in the hydrodynamic limit.

  5. Transformations and affinities for sulfur of Chinese Shenmu coal ash in a pulverized coal-fired boiler

    SciTech Connect (OSTI)

    Cheng, J.; Zhou, J.H.; Liu, J.Z.; Cao, X.Y.; Cen, K.F.

    2009-07-01

    The self-desulfurization efficiency of Shenmu coal with a high initial Ca/S molar ratio of 2.02 was measured in a 1,025 t/h pulverized coal-fired boiler. It increases from 29% to 32% when the power capacity decreases from 100% to 70%. About 60% of the mineral matter and calcium element fed into the furnace is retained in the fly ash, while less than 10% is retained in the bottom ash. About 70% of the sulfur element fed into the furnace is emitted as SO{sub 2} in the flue gas, while less than 10% is retained in the fly ash and less than 1% is retained in the bottom ash. The mineralogical compositions of feed coal, fly ash, and bottom ash were obtained by X-ray diffraction analysis. It is found that the initial amorphous phase content is 91.17% and the initial CaCO{sub 3} phase content is 2.07% in Shenmu coal. The vitreous phase and sulfation product CaSO{sub 4} contents are, respectively, 70.47% and 3.36% in the fly ash obtained at full capacity, while the retained CaCO{sub 3} and CaO contents are, respectively, 4.73% and 2.15%. However, the vitreous phase content is only 25.68% and no CaSO{sub 4} is detected in the bottom ash obtained at full capacity. When the power capacity decreases from 100% to 70%, the vitreous phase content in fly ash decreases from 70.47% to 67.41% and that in bottom ash increases from 25.68% to 28.10%.

  6. Long-range ferromagnetic order induced by a donor impurity band exchange in SnO{sub 2}:Er{sup 3+} nanoparticles

    SciTech Connect (OSTI)

    Aragn, F. H.; Coaquira, J. A. H.; Chitta, V. A.; Hidalgo, P.; Brito, H. F.

    2013-11-28

    In this work, the structural and magnetic properties of Er-doped SnO{sub 2} (SnO{sub 2}:Er) nanoparticles are reported. The SnO{sub 2}:Er nanoparticles have been synthesized by a polymer precursor method with Er content from 1.0% to 10.0%. X-ray diffraction results indicate the formation of only the rutile-type structure in all samples. The estimated mean crystallite size shows a decrease from ?10 to ?4?nm when the Er content is increased from 1.0% to 10.0%. The particle size values have been corroborated by transmission electron microscopy technique. The thermal dependence of the magnetization is consistent with the 3+ oxidation state of erbium ions for all samples. A strong paramagnetic-like behavior coexisting with a ferromagnetic phase has been determined for samples with Er content below 5.0%. Above this concentration, only a paramagnetic behavior has been determined. Isothermal magnetization curves are consistent with the occurrence of long-range ferromagnetic order mediated by donor electrons forming bound magnetic polarons which overlap to produce a spin-split impurity band.

  7. IMPACT OF FISSION PRODUCTS IMPURITY ON THE PLUTONIUM CONTENT IN PWR MOX FUELS

    SciTech Connect (OSTI)

    Gilles Youinou; Andrea Alfonsi

    2012-03-01

    This report presents the results of a neutronics analysis done in response to the charter IFCA-SAT-2 entitled 'Fuel impurity physics calculations'. This charter specifies that the separation of the fission products (FP) during the reprocessing of UOX spent nuclear fuel assemblies (UOX SNF) is not perfect and that, consequently, a certain amount of FP goes into the Pu stream used to fabricate PWR MOX fuel assemblies. Only non-gaseous FP have been considered (see the list of 176 isotopes considered in the calculations in Appendix 1). This mixture of Pu and FP is called PuFP. Note that, in this preliminary analysis, the FP losses are considered element-independent, i.e., for example, 1% of FP losses mean that 1% of all non-gaseous FP leak into the Pu stream.

  8. First-principles study of noble gas impurities and defects in UO{sub 2}

    SciTech Connect (OSTI)

    Thompson, Alexander E.; Wolverton, C.

    2011-10-01

    We performed a series of density functional theory + U (DFT + U) calculations to explore the energetics of various defects in UO{sub 2}, i.e., noble gases (He, Ne, Ar, Kr, Xe), Schottky defects, and the interaction between these defects. We found the following: (1) collinear antiferromagnetic UO{sub 2} has an energy-lowering distortion of the oxygen sublattice from ideal fluorite positions; (2) DFT + U qualitatively affects the formation volume of Schottky defect clusters in UO{sub 2} (without U the formation volume is negative, but including U the formation volume is positive); (3) the configuration of the Schottky defect cluster is dictated by a competition between electrostatic and surface energy effects; (4) the incorporation energy of inserting noble gas atoms into an interstitial site has a strong dependence on the volume of the noble gas atom, corresponding to the strain it causes in the interstitial site, from He (0.98 eV) to Xe (9.73 eV); (5) the energetics of each of the noble gas atoms incorporated in Schottky defects show strong favorable binding, due to strain relief associated with moving the noble gas atom from the highly strained interstitial position into the vacant space of the Schottky defect; and (6) for argon, krypton, and xenon, the binding energy of a noble gas impurity with the Schottky defect is larger than the formation energy of a Schottky defect, thereby making the formation of Schottky defects thermodynamically favorable in the presence of these large impurities.

  9. Consistent interaction vertices in arbitrary topological BF theories

    SciTech Connect (OSTI)

    Bizdadea, C.; Cioroianu, E. M.; Saliu, S. O.; Sararu, S. C.; Stanciu-Oprean, L.

    2013-11-13

    Here we extend the previous results from [12] to the computation of all consistent self-interactions for topological BF theories with maximal field spectra in D =5,6,7,8 and present some partial results on possible generalizations on a space-time of arbitrary dimension D. For convenience, the deformation of the solution to the master equation in the context of the BRST-antifield formalism is used as a general method of constructing consistent interacting gauge field theories together with most of the standard hypotheses on quantum field theories on Minkowski space-times.

  10. Exact solution of the self-consistent Vlasov equation

    SciTech Connect (OSTI)

    Morawetz, K.

    1997-03-01

    An analytical solution of the self-consistent Vlasov equation is presented. The time evolution is entirely determined by the initial distribution function. The largest Lyapunov exponent is calculated analytically. For special parameters of the potential a positive Lyapunov exponent is possible. This model may serve as a check for numerical codes solving self-consistent Vlasov equations. The here presented method is also applicable for any system with an analytical solution of the Hamilton equation for the form factor of the potential. {copyright} {ital 1997} {ital The American Physical Society}

  11. Consistency test of neutrinoless double beta decay with one isotope

    SciTech Connect (OSTI)

    Duerr, Michael; Lindner, Manfred [Max-Planck-Institut fuer Kernphysik, Postfach 10 39 80, 69029 Heidelberg (Germany); Zuber, Kai [Technical University Dresden, Institut fuer Kern- und Teilchenphysik, 01069 Dresden (Germany)

    2011-11-01

    We discuss a consistency test which makes it possible to discriminate unknown nuclear background lines from neutrinoless double beta decay with only one isotope. By considering both the transition to the ground state and to the first excited 0{sup +} state, a sufficiently large detector can reveal if neutrinoless double beta decay or some other nuclear physics process is at work. Such a detector could therefore simultaneously provide a consistency test for a certain range of Majorana masses and be sensitive to lower values of the effective Majorana mass .

  12. An analysis of the influence of impurities on fast particle attenuation and on fast ion spectral shape in LHD

    SciTech Connect (OSTI)

    Veshchev, Evgeny A.; Goncharov, Pavel R.; Ozaki, Tetsuo; Sudo, Shigeru

    2008-10-15

    Neutral particle fluxes measured by neutral particle analyzers can provide information about the ion temperature as well as the non-Maxwellian anisotropic ion distribution tails from neutral beam injection and ion cyclotron radio frequency heating. In the case of multidirectional diagnostics employing high resolution atomic energy spectrometers, the neutral atomic flux source is not localized in contrast to pellet charge exchange or diagnostic neutral beam methods. The correct interpretation of such measurements from plasma in a complex toroidally asymmetric geometry, like that of LHD, requires careful numerical modeling of the neutral flux formation. Previously a measured neutral flux calculation scheme was developed and was used for the LHD geometry and a suitable analytic expression for ionization cross sections {sigma}{sub s}{sup (z)}(E,n{sub e},T{sub e},Z{sub eff}) of impurities was formulated by Janev et al. [Nucl. Fusion 29, 2125 (1989)]. In this paper, the attenuation of fast particles by impurities is incorporated into the neutral flux calculation scheme and the influence of impurities on the calculated neutral flux spectra is shown. Finally, the behavior of the calculated and experimental suprathermal particle distributions is compared for pure hydrogen and for argon impurity seeded plasmas.

  13. Method of treating intermetallic alloy hydrogenation/oxidation catalysts for improved impurity poisoning resistance, regeneration and increased activity

    DOE Patents [OSTI]

    Wright, Randy B. (Idaho Falls, ID)

    1992-01-01

    Alternate, successive high temperature oxidation and reduction treatments, in either order, of intermetallic alloy hydrogenation and intermetallic alloy oxidation catalysts unexpectedly improves the impurity poisoning resistance, regeneration capacity and/or activity of the catalysts. The particular alloy, and the final high temperature treatment given alloy (oxidation or reduction) will be chosen to correspond to the function of the catalyst (oxidation or hydrogenation).

  14. Leaching characteristics of toxic constituents from coal fly ash mixed soils under the influence of pH

    SciTech Connect (OSTI)

    Komonweeraket, Kanokwan; Cetin, Bora; Benson, Craig H.; Aydilek, Ahmet H.; Edil, Tuncer B.

    2015-04-15

    Highlights: • The impact of pH on the leaching of elements and metals from fly ash mixed soils. • Generally Ca, Cd, Mg, and Sr follows a cationic leaching pattern. • The leaching of As and Se shows an oxyanionic leaching pattern. • The leaching behavior of elements does not change based on material type. • Different fly ash types show different abilities in immobilizing trace elements. - Abstract: Leaching behaviors of Arsenic (As), Barium (Ba), Calcium (Ca), Cadmium (Cd), Magnesium (Mg), Selenium (Se), and Strontium (Sr) from soil alone, coal fly ash alone, and soil-coal fly ash mixtures, were studied at a pH range of 2–14 via pH-dependent leaching tests. Seven different types of soils and coal fly ashes were tested. Results of this study indicated that Ca, Cd, Mg, and Sr showed cationic leaching pattern while As and Se generally follows an oxyanionic leaching pattern. On the other hand, leaching of Ba presented amphoteric-like leaching pattern but less pH-dependent. In spite of different types and composition of soil and coal fly ash investigated, the study reveals the similarity in leaching behavior as a function of pH for a given element from soil, coal fly ash, and soil-coal fly ash mixtures. The similarity is most likely due to similar controlling mechanisms (e.g., solubility, sorption, and solid-solution formation) and similar controlling factors (e.g., leachate pH and redox conditions). This offers the opportunity to transfer knowledge of coal fly ash that has been extensively characterized and studied to soil stabilized with coal fly ash. It is speculated that unburned carbon in off-specification coal fly ashes may provide sorption sites for Cd resulting in a reduction in concentration of these elements in leachate from soil-coal fly ash mixture. Class C fly ash provides sufficient CaO to initiate the pozzolanic reaction yielding hydrated cement products that oxyanions, including As and Se, can be incorporated into.

  15. Fibrous Fillers to Manufacture Ultra-High Ash/Performance Paper

    Broader source: Energy.gov [DOE]

    This factsheet describes a research project whose goal is to demonstrate the economic and technological viability of fibrous filler to manufacture paper containing up to 50% ash, at equal or better quality and performance than conventional alternatives and at a lower cost.

  16. How carbon-based sorbents will impact fly ash utilization and disposal

    SciTech Connect (OSTI)

    Pflughoeft-Hassett, D.F.; Hassett, D.J.; Buckley, T.D.; Heebink, L.V.; Pavlish, J.H.

    2008-07-01

    The injection of activated carbon flue gas to control mercury emissions will result in a fly ash and activated carbon mixture. The potential impact of this on coal combustion product disposal and utilization is discussed. The full paper (and references) are available at www.acaa-usa.org. 1 tab., 2 photos.

  17. Enhancement of Ca(OH){sub 2}/fly ash sorbent for the dry-desulfurization process

    SciTech Connect (OSTI)

    Mitsuo Yamamoto; Satoshi Komaki; Daichi Nakajima; Norihiko Matsushima; Dan Liu; Masateru Nishioka; Masayoshi Sadakata

    2006-10-15

    Ca(OH){sub 2}/fly ash sorbent has been studied as an effective method for SO{sub 2} removal. The effect of iron and other species for enhancing the ability of Ca(OH){sub 2}/fly ash sorbent was investigated in this study. At first, Fe(NO{sub 3}){sub 3} was added in the preparation of the sorbent, and TG analysis was carried out. The Ca utilization rate over a period of 90 min was about 10% greater than that for Ca(OH){sub 2}/fly ash sorbent. However, it was found that iron is not effective for enhancing the ability of Ca(OH){sub 2}/fly ash sorbent but that NO{sub 3}{sup -} was the most effective factor to enhance it. The mechanism of enhancing the Ca utilization rate was also investigated, and it was found that Ca(NO{sub 3})2 was produced in the sorbent and reacted with SO{sub 2}, so that the reaction Ca(NO{sub 3}){sub 2} + SO{sub 2} {yields} CaSO{sub 4} + 2NO + O{sub 2} proceeded. 12 refs., 6 figs., 3 tabs.

  18. Mechanical Properties of Aluminum Matrix Composite Reinforced by Carbothermally Reduced of Fly Ash

    SciTech Connect (OSTI)

    Jamasri; Wildan, M. W.; Sulardjaka; Kusnanto

    2011-01-17

    The addition of fly ash into aluminum as reinforcement can potentially reduce the production cost and density of aluminum. However, mechanical properties of aluminum matrix composite reinforced by fly ash (MMC ALFA) have some limitations due to the characteristic of fly ash. In this study, a carbothermal reduction process of fly ash and activated carbon powder with particle size <32 {mu}m was performed prior to produce MMC ALFA.The process was carried out in a furnace at 1300 deg. C in vacuum condition under argon flow. Synthesis product was analyzed by XRD with Cu-K{sub {alpha}} radiation. From XRD analysis, it shows that the synthesis process can produce SiC powder. The synthesis product was subsequently used as reinforcement particle. Aluminum powder was mixed with 5, 10 and 15% of the synthesized powder, and then uni-axially compacted at pressure of 300 MPa. The compacted product was sintered for 2 hours in argon atmosphere at temperature variation of 550 and 600 deg. C. Flexural strength, hardness and density of MMC ALFA's product were respectively evaluated using a four point bending test method based on ASTM C1161 standard, Brinell hardness scale and Archimedes method. The result of this study shows that the increase of weight of reinforcement can significantly increase the hardness and flexural strength of MMCs. The highest hardness and flexural strength of the MMC product are 300 kg/mm{sup 2} and 107.5 MPa, respectively.

  19. Evaluation of leaching and ecotoxicological properties of sewage sludge-fly ash mixtures

    SciTech Connect (OSTI)

    C.A. Papadimitriou; I. Haritou; P. Samaras; A.I. Zouboulis

    2008-03-15

    The objectives of this work were the evaluation of sewage sludge stabilization by mixing with fly ash, the examination of the physicochemical properties of the produced materials and their leachates and the assessment of their environmental impact by the evaluation of the ecotoxic characteristics. Different ratios of fly ash and sewage sludge (1:1, 1:2, 1:3, 1:6, and 1:9) were mixed for 48 and 72 h. After mixing, the liquid phase of the produced materials was analyzed for total coliforms and Escherichia coli, while the solid residue was dried and tested for the leaching characteristics by the application of TCLP and EN 12457-2 standard leaching methods. Furthermore, the produced leachates were analyzed for their content of specific metals, while their ecotoxicological characteristics were determined by the use of toxicity bioassays, using the marine photobacterium Vibrio fischeri and the crustacean Daphnia magna. The phytotoxicity of sewage sludge-fly ash mixtures was also determined by utilizing seeds of three higher plants (one monocotyl and two dicotyls). The mixtures exhibited low metal leaching in all cases, while the ecotoxic properties increased with the increase of fly ash/sewage sludge ratio. The phytotoxicity testing showed increased root length growth inhibition.

  20. Microwave-assisted sample preparation of coal and coal fly ash for subsequent metal determination

    SciTech Connect (OSTI)

    Srogi, K.

    2007-01-15

    The aim of this paper is to review microwave-assisted digestion of coal and coal fly ash. A brief description of microwave heating principles is presented. Microwave-assisted digestion appears currently to be the most popular preparation technique, possibly due to the comparatively rapid sample preparation and the reduction of contamination, compared to the conventional hot-plate digestion methods.

  1. The Council of Industrial Boiler Owners special project on non-utility fossil fuel ash classification

    SciTech Connect (OSTI)

    Svendsen, R.L.

    1996-12-31

    Information is outlined on the Council of Industrial Boiler Owners (CIBO) special project on non-utility fossil fuel ash classification. Data are presented on; current (1996) regulatory status of fossil-fuel combustion wastes; FBC technology identified for further study; CIBO special project methods; Bevill amendment study factors; data collection; and CIBO special project status.

  2. Electric-resistance furnace for melting ash from municipal solid waste incinerator

    SciTech Connect (OSTI)

    Nakao, Tsuyoshi; Nakahara, Keisuke; Akashi, Tetsuo

    1997-12-31

    Existing landfill capacity is dwindling in Japan and it is difficult to find new landfill sites because of strong opposition from residents. Under the Waste Disposal and Public Cleaning Law in 1991 in Japan, fly ashes from municipal solid waste (MSW) incinerator have to be treated by one of the four methods: (1) vitrification, (2) solidification by cement, (3) stabilization using chemical agents, or (4) extraction with acid or other solvent. In these four technologies, the vitrification technology has some advantages: decreasing ash volume which can solve the landfill problem, de-taxiing ash, and utilization of its products from residues. NKK has developed an electric resistance furnace for melting MSW incineration residues and built a demonstration plant (24t/d). The performance test results showed as follows; (1) Si, Al, and Ca tended to become the molten slag. Cu, P, and Fe tended to become the molten metal. Pb, Zn, and Cd tended to become the molten fly ash. (2) HCl from the slag resistance electric furnace was 60 ppm and very low compared with other melting systems. (3) Decomposition rate of dioxins was 99 % in the melting furnace. (4) Concentration of heavy metals in the molten slag was low and leaching of heavy metals was below Japanese regulation.

  3. Long-term leaching test of incinerator bottom ash: Evaluation of Cu partition

    SciTech Connect (OSTI)

    Lin, Cheng-Fang Wu, Chung-Hsin; Liu, Yen-Chiun

    2007-07-01

    Two types of leaching tests were performed on the bottom ash from municipal solid waste incinerators. A short-term batch test specified by the America Nuclear Society (ANS) and long-term column tests with acetic acid (pH 5.2) as leaching solution were used to evaluate copper leachability. The Cu leaching after the 5-d ANS test is about 1% of the original Cu content of 5300 mg/kg. Upon addition of a stabilizing agent, the Cu leaching quantity is reduced; the extent of reduction depends on the type of chemical used (phosphate, carbonate and sulfide). The 1.6% Na{sub 2}S addition showed negligible Cu leaching, and Na{sub 2}S was, therefore, used in subsequent column tests. The 30-d column test indicates a steady increase of Cu leaching amount with time and reaches about 1.5% of the original Cu content after 30 d. A 180-d column test further increased the Cu leaching to about 5.1% of the original Cu content, whereas no appreciable Cu leaching was found with the addition of 1.6% Na{sub 2}S. A sequential extraction was conducted on the raw ash, ash with the addition of Na{sub 2}S and the residue ash after 30 d of operation to characterize Cu affinity for different solid fractions. The data were used to evaluate the fate of Cu through these interactions.

  4. Fish Health Studies Associated with the Kingston Fly Ash Spill, Spring 2009 - Fall 2010

    SciTech Connect (OSTI)

    Adams, Marshall; Fortner, Allison M

    2012-05-01

    On December 22, 2008, over 4 million cubic meters of fly ash slurry was released into the Emory River when a dike surrounding a solid waste containment area at the Tennessee Valley Authority's (TVA) Kingston Fossil Plant ruptured. One component of TVA's response to the spill is a biological monitoring program to assess short- and long-term ecological responses to the ash and associated chemicals, including studies on fish health and contaminant bioaccumulation. These studies were initiated in early Spring 2009 for the purposes of: (1) documenting the levels of fly ash-associated metals in various tissues of representative sentinel fish species in the area of the fly ash spill, (2) determining if exposure to fly ash-associated metals causes short, intermediate, or long-term health effects on these sentinel fish species, (3) assessing if there are causal relationships between exposure to metals and health effects on fish, (4) evaluating, along with information from other ecological and physicochemical studies, the nature and route of contaminant transfer though food chains into higher level consumers, (5) providing important information for the Ecological Risk Assessment (ERA) for the Kingston fly ash project, and (6) serving as an important technology information transfer or model study focused on how to best evaluate the environmental effects of fly ash (and related environmental stressors), not only at the Kingston site, but also at sites on other aquatic systems where coal-fired generating stations are located. This report presents the results of the first two years of the fish health study. To date, fish health and bioaccumulation studies have been conducted from Spring 2009 though Fall 2011 and includes 6 seasonal studies: Spring 2009, Fall 2009, Spring 2010, Fall 2010, Spring 2011, and Fall 2011. Both the Spring and Fall studies have focused on 3-4 sentinel fish species that represent different feeding habits, behaviors, and home ranges. In addition to fish

  5. Impurity Profiling of a Chemical Weapon Precursor for Possible Forensic Signatures by Comprehensive Two-Dimensional Gas Chromatography/Mass Spectrometry and Chemometrics

    SciTech Connect (OSTI)

    Hoggard, Jamin C.; Wahl, Jon H.; Synovec, Robert E.; Mong, Gary M.; Fraga, Carlos G.

    2010-01-15

    In this work we present the feasibility of using analytical chemical and chemometric methodologies to reveal and exploit the organic impurity profiles from commercial dimethyl methylphosphonate (DMMP) samples to illustrate the type of forensic information that may be obtained from chemical-attack evidence. Using DMMP as a model compound for a toxicant that may be used in a chemical attack, we used comprehensive two-dimensional gas chromatography mass spectrometric detection (GC GC-TOFMS) to detect and identify trace organic impurities in six samples of commercially acquired DMMP. The GC x GC-TOFMS data were analyzed to produce impurity profiles for all six DMMP samples using 29 analyte impurities. The use of PARAFAC for the mathematical resolution of overlap GC x GC peaks ensured clean spectra for the identification of many of the detected analytes by spectral library matching. The use of statistical pairwise comparison revealed that there were trace impurities that were quantitatively similar and different among five of the six DMMP samples. Two of the DMMP samples were revealed to have identical impurity profiles by this approach. The use of nonnegative matrix factorization proved that there were five distinct DMMP sample types as illustrated by the clustering of the multiple DMMP analyses into 5 distinct clusters in the scores plots. The two indistinguishable DMMP samples were confirmed by their chemical supplier to be from the same bulk source. Sample information from the other chemical suppliers supported that the other five DMMP samples were likely from different bulk sources. These results demonstrate that the matching of synthesized products from the same source is possible using impurity profiling. In addition, the identified impurities common to all six DMMP samples provide strong evidence that basic route information can be obtained from impurity profiles. In addition, impurities that may be unique to the sole bulk manufacturer of DMMP were found in

  6. Consistent Data Assimilation of Isotopes: 242Pu and 105Pd

    SciTech Connect (OSTI)

    G. Palmiotti; H. Hiruta; M. Salvatores

    2012-09-01

    In this annual report we illustrate the methodology of the consistent data assimilation that allows to use the information coming from integral experiments for improving the basic nuclear parameters used in cross section evaluation. A series of integral experiments are analyzed using the EMPIRE evaluated files for 242Pu and 105Pd. In particular irradiation experiments (PROFIL-1 and -2, TRAPU-1, -2 and -3) provide information about capture cross sections, and a critical configuration, COSMO, where fission spectral indexes were measured, provides information about fission cross section. The observed discrepancies between calculated and experimental results are used in conjunction with the computed sensitivity coefficients and covariance matrix for nuclear parameters in a consistent data assimilation. The results obtained by the consistent data assimilation indicate that not so large modifications on some key identified nuclear parameters allow to obtain reasonable C/E. However, for some parameters such variations are outside the range of 1 s of their initial standard deviation. This can indicate a possible conflict between differential measurements (used to calculate the initial standard deviations) and the integral measurements used in the statistical data adjustment. Moreover, an inconsistency between the C/E of two sets of irradiation experiments (PROFIL and TRAPU) is observed for 242Pu. This is the end of this project funded by the Nuclear Physics Program of the DOE Office of Science. We can indicate that a proof of principle has been demonstrated for a few isotopes for this innovative methodology. However, we are still far from having explored all the possibilities and made this methodology to be considered proved and robust. In particular many issues are worth further investigation: • Non-linear effects • Flexibility of nuclear parameters in describing cross sections • Multi-isotope consistent assimilation • Consistency between differential and integral

  7. Electronic structures and ferromagnetism of SnO{sub 2} (rutile) doped with double-impurities: First-principles calculations

    SciTech Connect (OSTI)

    Fakhim Lamrani, A.; Belaiche, M.; Benyoussef, A.; and others

    2014-01-07

    The electronic and magnetic properties of double-impurities-doped SnO{sub 2} (rutile) are explored using first-principles calculations within the generalized gradient approximation to examine their potential use as spintronic system. Calculations are performed for double impurities (M1 and M2) from M1 = Cr, and M2 = Mn, and Re. The origins of ferromagnetism are shown to be different in the two cases. For Sn{sub 1-2x}Cr{sub x}Mn{sub x}O2, the hybridization between Cr-3d and O-2p results in Cr becoming ferromagnetic with a magnetic moment of about 5.0 μ{sub B} per supercell. The Cr-and Mn-doped SnO{sub 2} system exhibits half-metallic ferromagnetism. The strong ferromagnetic couplings between local magnetic moments can be attributed to p-d hybridization. In contrast, in (Cr, Re) codoped TiO{sub 2}, the local magnetic moments of the impurities and their oxidation states agree with the charge transfer between Cr and Re, which would lead to the ferromagnetic through the double-exchange mechanism in transition metal oxides. Since there are two possible couplings between the impurities, we studied both configurations (ferromagnetic and antiferromagnetic (AF)) for double-impurities-doped SnO{sub 2}. Our calculations show that a ferromagnetic alignment of the spins is energetically always more stable than simple AF arrangements, which makes these materials possible candidates for spin injection in spintronic devices.

  8. Commercial Demonstration of the Manufactured Aggregate Processing Technology Utilizing Spray Dryer Ash

    SciTech Connect (OSTI)

    Milton Wu; Paul Yuran

    2006-12-31

    Universal Aggregates LLC (UA) was awarded a cost sharing Co-operative Agreement from the Department of Energy (DOE) through the Power Plant Improvement Initiative Program (PPII) to design, construct and operate a lightweight aggregate manufacturing plant at the Birchwood Power Facility in King George, Virginia in October 2001. The Agreement was signed in November 2002. The installation and start-up expenses for the Birchwood Aggregate Facility are $19.5 million. The DOE share is $7.2 million (37%) and the UA share is $12.3 million (63%). The original project team consists of UA, SynAggs, LLC, CONSOL Energy Inc. and P. J. Dick, Inc. Using 115,000 ton per year of spray dryer ash (SDA), a dry FGD by-product from the power station, UA will produce 167,000 tons of manufactured lightweight aggregate for use in production of concrete masonry units (CMU). Manufacturing aggregate from FGD by-products can provide an economical high-volume use and substantially expand market for FGD by-products. Most of the FGD by-products are currently disposed of in landfills. Construction of the Birchwood Aggregate Facility was completed in March 2004. Operation startup was begun in April 2004. Plant Integration was initiated in December 2004. Integration includes mixing, extrusion, curing, crushing and screening. Lightweight aggregates with proper size gradation and bulk density were produced from the manufacturing aggregate plant and loaded on a stockpile for shipment. The shipped aggregates were used in a commercial block plant for CMU production. However, most of the production was made at low capacity factors and for a relatively short time in 2005. Several areas were identified as important factors to improve plant capacity and availability. Equipment and process control modifications and curing vessel clean up were made to improve plant operation in the first half of 2006. About 3,000 tons of crushed aggregate was produced in August 2006. UA is continuing to work to improve plant

  9. Interaction of planar and nonplanar organic contaminants with coal fly ash: Effects of polar and nonpolar solvent solutions

    SciTech Connect (OSTI)

    Burgess, R.M.; Ryba, S.A.; Cantwell, M.G.; Gundersen, J.L.; Tien, R.; Perron, M.M.

    2006-08-15

    Coal fly ash has a very high sorption capacity for a variety of anthropogenic contaminants and has been used to cleanse wastewater of pollutants for approximately 40 years. Like other black carbons, the planar structure of the residual carbon in fly ash results in elevated affinities for planar organic contaminants, such as polycyclic aromatic hydrocarbons (PAHs) and some polychlorinated biphenyls (PCBs). The present study was performed to understand better the mechanisms affecting the strong interaction between planar contaminants and coal fly ash. The removal of 10 PCBs and 10 PAHs by several fly ashes and other sorbents was evaluated under different experimental conditions to highlight the intermolecular forces influencing adsorption. Varying fly ash concentration and solvent system composition indicated that dispersive interactions were most prevalent. For the PCBs, empirical results also were compared to molecular modeling estimates of the energy necessary for the PCB molecule to assume a planar conformation (PCe). The PCe levels ranged from 8 to 25 kcal/mol, depending on the degree of ortho-substituted chlorination of the PCB. A significant correlation between PCe and PCB removal from solution was observed for the fly ashes and activated carbon, whereas the nonplanar sorbent octadecyl (C{sub 18}) indicated no relationship. These findings demonstrate the strong interaction between black carbon fly ash and planar organic contaminants. Furthermore, as exemplified by the PCBs, these results show how this interaction is a function of a contaminant's ability to assume a planar conformation.

  10. Distribution of polycyclic aromatic hydrocarbons in fly ash during coal and residual char combustion in a pressurized fluidized bed

    SciTech Connect (OSTI)

    Hongcang Zhou; Baosheng Jin; Rui Xiao; Zhaoping Zhong; Yaji Huang

    2009-04-15

    To investigate the distribution of polycyclic aromatic hydrocarbons (PAHs) in fly ash, the combustion of coal and residual char was performed in a pressurized spouted fluidized bed. After Soxhlet extraction and Kuderna-Danish (K-D) concentration, the contents of 16 PAHs recommended by the United States Environmental Protection Agency (U.S. EPA) in coal, residual char, and fly ash were analyzed by a high-performance liquid chromatography (HPLC) coupled with fluorescence and diode array detection. The experimental results show that the combustion efficiency is lower and the carbon content in fly ash is higher during coal pressurized combustion, compared to the residual char pressurized combustion at the pressure of 0.3 MPa. Under the same pressure, the PAH amounts in fly ash produced from residual char combustion are lower than that in fly ash produced from coal combustion. The total PAHs in fly ash produced from coal and residual char combustion are dominated by three- and four-ring PAHs. The amounts of PAHs in fly ash produced from residual char combustion increase and then decrease with the increase of pressure in a fluidized bed. 21 refs., 1 fig., 4 tabs.

  11. Task 3.0 -- Advanced power systems: Subtask 3.18 -- Ash behavior in power systems. Semi-annual report, June 1--December 31, 1997

    SciTech Connect (OSTI)

    Zygarlicke, C.J.; McCollor, D.P.; Folkedahl, B.C.; Swanson, M.L.; Musich, M.A.

    1998-10-01

    Advanced power systems such as integrated gasifier combined cycle systems and fluidized bed systems are at the forefront of power industry research because of the need for increased efficiency and the reduction of greenhouse gases. Ash behavior in power systems can have a significant impact on the design and performance of these systems. The Energy and Environmental Research Center (EERC) has developed a focused research initiative aimed at filling gaps in the understanding of fundamental mechanisms of ash behavior, which has relevance to commercial application and marketable products associated with advanced power systems. This program develops methods and means to better understand and mitigate adverse coal ash behavior in advanced power systems and can act to relieve the US reliance on diminishing recoverable oil resources and other greenhouse-producing fossil fuels. Subtask 3.18 is structured as three tasks. Task 1 pertains to summarizing the critical issues in ash behavior, especially for advanced power systems. Task 2 focuses on fundamental ash sintering and viscosity-ash composition relationships that are critical for developing a better mechanistic understanding of ash deposit formation and for predicting ash behavior. Task 3 is aimed primarily at determining the role of the ash chemistry and phase relationships for specific ash interactions in advanced power systems. The role of sulfides in the formation of ash deposits in gasification systems and the factors that influence alloy corrosion in supercritical boilers will be specifically analyzed. Task results to date are presented.

  12. Non-trivial checks of novel consistency relations

    SciTech Connect (OSTI)

    Berezhiani, Lasha; Khoury, Justin; Wang, Junpu E-mail: jkhoury@sas.upenn.edu

    2014-06-01

    Single-field perturbations satisfy an infinite number of consistency relations constraining the squeezed limit of correlation functions at each order in the soft momentum. These can be understood as Ward identities for an infinite set of residual global symmetries, or equivalently as Slavnov-Taylor identities for spatial diffeomorphisms. In this paper, we perform a number of novel, non-trivial checks of the identities in the context of single field inflationary models with arbitrary sound speed. We focus for concreteness on identities involving 3-point functions with a soft external mode, and consider all possible scalar and tensor combinations for the hard-momentum modes. In all these cases, we check the consistency relations up to and including cubic order in the soft momentum. For this purpose, we compute for the first time the 3-point functions involving 2 scalars and 1 tensor, as well as 2 tensors and 1 scalar, for arbitrary sound speed.

  13. On the grade consistent theories of micromorphic elastic solids

    SciTech Connect (OSTI)

    Iesan, D.

    2011-02-10

    For the investigation of specific nonlocal phenomena the second-order displacement gradient has been added to the independent constitutive variables used in the classical theories of elastic solids. In this paper we outline the hystorical development of the subject and present a nonlinear grade consistent theory of micromorphic elastic solids in which the independent constitutive variables are the deformation gradient, the second-order displacement gradient, microdeformation tensor, and microdeformation gradient. Then, we present the linearized theory and establish a uniqueness result with no definiteness assumption on the elastic coefficients. The theory is used to obtain the basic eqations of a grade consistent theory of microstretch elastic bodies. The field equations for an isotropic and homogeneous elastic body are presented. A counterpart of the Cauchy-Kowalevski-Somigliana solution of the classical elastodynamics is established.

  14. Full self-consistency versus quasiparticle self-consistency in diagrammatic approaches: Exactly solvable two-site Hubbard model

    SciTech Connect (OSTI)

    Kutepov, A. L.

    2015-07-22

    Self-consistent solutions of Hedin's equations (HE) for the two-site Hubbard model (HM) have been studied. They have been found for three-point vertices of increasing complexity (Γ = 1 (GW approximation), Γ₁ from the first-order perturbation theory, and the exact vertex ΓE). Comparison is made between the cases when an additional quasiparticle (QP) approximation for Green's functions is applied during the self-consistent iterative solving of HE and when QP approximation is not applied. Results obtained with the exact vertex are directly related to the present open question—which approximation is more advantageous for future implementations, GW + DMFT or QPGW + DMFT. It is shown that in a regime of strong correlations only the originally proposed GW + DMFT scheme is able to provide reliable results. Vertex corrections based on Perturbation Theory systematically improve the GW results when full self-consistency is applied. The application of QP self-consistency combined with PT vertex corrections shows similar problems to the case when the exact vertex is applied combined with QP sc. An analysis of Ward Identity violation is performed for all studied in this work's approximations and its relation to the general accuracy of the schemes used is provided.

  15. Full self-consistency versus quasiparticle self-consistency in diagrammatic approaches: Exactly solvable two-site Hubbard model

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

    Kutepov, A. L.

    2015-07-22

    Self-consistent solutions of Hedin's equations (HE) for the two-site Hubbard model (HM) have been studied. They have been found for three-point vertices of increasing complexity (Γ = 1 (GW approximation), Γ₁ from the first-order perturbation theory, and the exact vertex ΓE). Comparison is made between the cases when an additional quasiparticle (QP) approximation for Green's functions is applied during the self-consistent iterative solving of HE and when QP approximation is not applied. Results obtained with the exact vertex are directly related to the present open question—which approximation is more advantageous for future implementations, GW + DMFT or QPGW + DMFT.more » It is shown that in a regime of strong correlations only the originally proposed GW + DMFT scheme is able to provide reliable results. Vertex corrections based on Perturbation Theory systematically improve the GW results when full self-consistency is applied. The application of QP self-consistency combined with PT vertex corrections shows similar problems to the case when the exact vertex is applied combined with QP sc. An analysis of Ward Identity violation is performed for all studied in this work's approximations and its relation to the general accuracy of the schemes used is provided.« less

  16. Diagnostic Mass-Consistent Wind Field Monte Carlo Dispersion Model

    Energy Science and Technology Software Center (OSTI)

    1991-01-01

    MATHEW generates a diagnostic mass-consistent, three-dimensional wind field based on point measurements of wind speed and direction. It accounts for changes in topography within its calculational domain. The modeled wind field is used by the Langrangian ADPIC dispersion model. This code is designed to predict the atmospheric boundary layer transport and diffusion of neutrally bouyant, non-reactive species as well as first-order chemical reactions and radioactive decay (including daughter products).

  17. Integrated production/use of ultra low-ash coal, premium liquids and clean char. [Quarterly] report, December 1, 1991--February 29, 1992

    SciTech Connect (OSTI)

    Kruse, C.W.

    1992-08-01

    The first step in the integrated, mufti-product approach for utilizing Illinois coal is the production of ultra low-ash coal. Subsequent steps convert low-ash coal to high-value, coal-derived, products. The ultra low-ash coal is produced by solubilizing coal in a phenolic solvent under ChemCoal{trademark} process conditions, separating the coal solution from insoluble ash, and then precipitating the clean coal by dilution of the solvent with methanol. Two major products, liquids and low-ash char, are then produced by mild gasification of the low-ash coal. The low ash-char is further upgraded to activated char, and/or an oxidized activated char which has catalytic properties. Characterization of products at each stage is part of this project.

  18. Environmental and technical assessments of the potential utilization of sewage sludge ashes (SSAs) as secondary raw materials in construction

    SciTech Connect (OSTI)

    Chen, Maozhe [Universit de Lyon, INSA LYON, Laboratoire de Gnie Civil et Ingnierie Environnementale (LGCIE), Btiment Sadi Carnot, 20 avenue A. Einstein, 69621 Villeurbanne Cedex (France); Blanc, Denise, E-mail: denise.blanc-biscarat@insa-lyon.fr [Universit de Lyon, INSA LYON, Laboratoire de Gnie Civil et Ingnierie Environnementale (LGCIE), Btiment Sadi Carnot, 20 avenue A. Einstein, 69621 Villeurbanne Cedex (France); Gautier, Mathieu; Mehu, Jacques; Gourdon, Rmy [Universit de Lyon, INSA LYON, Laboratoire de Gnie Civil et Ingnierie Environnementale (LGCIE), Btiment Sadi Carnot, 20 avenue A. Einstein, 69621 Villeurbanne Cedex (France)

    2013-05-15

    Highlights: ? We used sewage sludge ashes in ready-mix concrete recipe. ? SSAs were used as a substitution of cement. ? Compressive strength of ready-mix concrete incorporating SSAs were similar as blank one. ? Contaminants leaching from concrete monoliths were above threshold limits. - Abstract: Ashes produced by thermal treatments of sewage sludge exhibit common properties with cement. For example, major elements present in SSA are the same of major elements of cement. Hydraulic properties of SSA are quite the same of cement ones. They may therefore be used to substitute part of cement in concrete or other cementitious materials, provided that technical prescriptions are satisfied and that environmental risks are not significantly increased. The objective of the present study was to determine the appropriate substitution ratios to satisfy both technical and environmental criteria. In a first step, the elemental composition and particle size distribution of the ashes were measured. Then the ashes were used along with Portland cement and sand at different ratios of substitution to produce mortar and concrete which were cured for up to 90 days into parallelepipedic or cylindrical monoliths. The mechanical properties of the monoliths were measured using standard procedures for flexural and compressive strengths, and compared to blanks containing no ashes. The environmental criteria were assessed using leaching tests conducted according to standard protocols both on the ashes and the monoliths, and compared to the blanks. Results showed that the characteristics of the ashes ranged between those of cement and sand because of their larger particle size and higher content in SiO{sub 2} as compared to cement. The monoliths made with the highest substitution ratios exhibited a significant decrease in flexural and compressive strengths. However, when the ashes were used in partial substitution of cement at appropriate ratios, the concrete monoliths exhibited similar

  19. EVALUATING THE EFFECTS OF FLY ASH EXPOSURE ON FISH EARLY LIFE STAGES: FATHEAD MINNOW EMBRYO-LARVAL TESTS

    SciTech Connect (OSTI)

    Greeley Jr, Mark Stephen; Elmore, Logan R; McCracken, Kitty

    2012-05-01

    On December 22, 2008, a dike containing fly ash and bottom ash in an 84-acre complex of the Tennessee Valley Authority's (TVA) Kingston Steam Plant in East Tennessee failed and released a large quantity of ash into the adjacent Emory River. Ash deposits extended as far as 4 miles upstream (Emory River mile 6) of the Plant, and some ash was carried as far downstream as Tennessee River mile 564 ({approx}4 miles downstream of the Tennessee River confluence with the Clinch River). A byproduct of coal burning power plants, fly ash contains a variety of metals and other elements which, at sufficient concentrations and in specific forms, can be toxic to biological systems. The effects of fly ash contamination on exposed fish populations depend on the magnitude and duration of exposure, with the most significant risk considered to be the effects of specific ash constituents, especially selenium, on fish early life stages. Uptake by adult female fish of fly ash constituents through the food chain and subsequent maternal transfer of contaminants to the developing eggs is thought to be the primary route of selenium exposure to larval fish (Woock and others 1987, Coyle and others 1993, Lemly 1999, Moscatello and others 2006), but direct contact of the fertilized eggs and developing embryos to ash constituents in river water and sediments is also a potential risk factor (Woock and others 1987, Coyle and others 1993, Jezierska and others 2009). To address the risk of fly ash from the Kingston spill to the reproductive health of downstream fish populations, ORNL has undertaken a series of studies in collaboration with TVA including: (1) a field study of the bioaccumulation of fly ash constituents in fish ovaries and the reproductive condition of sentinel fish species in reaches of the Emory and Clinch Rivers affected by the fly ash spill; (2) laboratory tests of the potential toxicity of fly ash from the spill area on fish embryonic and larval development (reported in the current

  20. Quantification of the resource recovery potential of municipal solid waste incineration bottom ashes

    SciTech Connect (OSTI)

    Allegrini, Elisa; Maresca, Alberto; Olsson, Mikael Emil; Holtze, Maria Sommer; Boldrin, Alessio; Astrup, Thomas Fruergaard

    2014-09-15

    Highlights: • Ferrous and non-ferrous metals were quantified in MSWI bottom ashes. • Metal recovery system efficiencies for bottom ashes were estimated. • Total content of critical elements was determined in bottom ash samples. • Post-incineration recovery is not viable for most critical elements. - Abstract: Municipal solid waste incineration (MSWI) plays an important role in many European waste management systems. However, increasing focus on resource criticality has raised concern regarding the possible loss of critical resources through MSWI. The primary form of solid output from waste incinerators is bottom ashes (BAs), which also have important resource potential. Based on a full-scale Danish recovery facility, detailed material and substance flow analyses (MFA and SFA) were carried out, in order to characterise the resource recovery potential of Danish BA: (i) based on historical and experimental data, all individual flows (representing different grain size fractions) within the recovery facility were quantified, (ii) the resource potential of ferrous (Fe) and non-ferrous (NFe) metals as well as rare earth elements (REE) was determined, (iii) recovery efficiencies were quantified for scrap metal and (iv) resource potential variability and recovery efficiencies were quantified based on a range of ashes from different incinerators. Recovery efficiencies for Fe and NFe reached 85% and 61%, respectively, with the resource potential of metals in BA before recovery being 7.2%ww for Fe and 2.2%ww for NFe. Considerable non-recovered resource potential was found in fine fraction (below 2 mm), where approximately 12% of the total NFe potential in the BA were left. REEs were detected in the ashes, but the levels were two or three orders of magnitude lower than typical ore concentrations. The lack of REE enrichment in BAs indicated that the post-incineration recovery of these resources may not be a likely option with current technology. Based on these results