National Library of Energy BETA

Sample records for grain size distribution

  1. Consideration of Grain Size Distribution in the Diffusion of Fission Gas to Grain Boundaries

    SciTech Connect (OSTI)

    Paul C. Millett; Yongfeng Zhang; Michael R. Tonks; S. B. Biner

    2013-09-01

    We analyze the accumulation of fission gas on grain boundaries in a polycrystalline microstructure with a distribution of grain sizes. The diffusion equation is solved throughout the microstructure to evolve the gas concentration in space and time. Grain boundaries are treated as infinite sinks for the gas concentration, and we monitor the cumulative gas inventory on each grain boundary throughout time. We consider two important cases: first, a uniform initial distribution of gas concentration without gas production (correlating with post-irradiation annealing), and second, a constant gas production rate with no initial gas concentration (correlating with in-reactor conditions). The results show that a single-grain-size model, such as the Booth model, over predicts the gas accumulation on grain boundaries compared with a polycrystal with a grain size distribution. Also, a considerable degree of scatter, or variability, exists in the grain boundary gas accumulation when comparing all of the grain boundaries in the microstructure.

  2. Low pressure shock initiation of porous HMX for two grain size distributions and two densities

    SciTech Connect (OSTI)

    Gustavsen, R.L.; Sheffield, S.A.; Alcon, R.R.

    1995-09-01

    Shock initiation measurements have been made on granular HMX (octotetramethylene tetranitrainine) for two particle size distributions and two densities. Samples were pressed to either 65% or 73% of crystal density from fine ({approx} 10 {mu}m grain size) and coarse (broad distribution of grain sizes peaking at {approx} 150 {mu}m) powders. Planar shocks of 0.2--1 GPa were generated by impacting gas gun driven projectiles on plastic targets containing the HMX. Wave profiles were measured at the input and output of the {approx} 3.9 mm thick HMX layer using electromagnetic particle velocity gauges. The initiation behavior for the two particle size distributions was very different. The coarse HMX began initiating at input pressures as low as 0.5 GPa. Transmitted wave profiles showed relatively slow reaction with most of the buildup occurring at the shock front. In contrast, the fine particle HMX did not begin to initiate at pressures below 0.9 GPa. When the fine powder did react, however, it did so much faster than the coarse HMX. These observations are consistent with commonly held ideas about bum rates being correlated to surface area, and initiation thresholds being correlated with the size and temperature of the hot spots created by shock passage. For each size, the higher density pressings were less sensitive than the lower density pressings.

  3. Shoreline, grain-size, and total-carbon distribution changes before and after Hurricane Alicia, Galveston Island, Texas, 1983

    SciTech Connect (OSTI)

    Rothammer, C.M.; Morrison, L.R.; Warkentin, S.L.

    1985-02-01

    Shoreline, grain-size, and sediment total-carbon changes were monitored, on a monthly basis, on three Galveston Island beaches, from January through December 1983. The study area included: (1) East Beach, obstructed by groins and a seawall; (2) Galveston Island State Park, obstructed by fences artificially stabilizing the dunes; and (3) West Beach, an unobstructed beach. Beach profiles revealed the effects of beach obstruction, such as erosion and undercutting at East Beach, and truncation of the dunes at Galveston Island State Park. Approximately 20 m of expansional cutback occurred on the beaches after Hurricane Alicia hit on August 18, 1983. Contour maps of grain-size and total-carbon distributions reflect the movement of beach sand by either onshore-offshore transport during low-energy periods, or longshore, edge-wave transport during high-energy periods. Statistical analyses revealed a small variation in grain size throughout the year. There were well-defined times of either no correlation or strong correlation between total carbon vs. mean grain size, skewness vs. mean grain size, kurtosis vs. mean grain size, skewness vs. mean grain size, kurtosis vs. mean grain size, total carbon vs. percent sand, total carbon vs. skewness, and skewness vs. kurtosis. Strong correlation was found in response to high-energy events, whereas no correlation was found in response to low-energy events. Galveston Island is undergoing net erosion and appears to be in a metastable state, still capable of responding to oceanographic conditions. The economic effects of Hurricane Alicia include considerable loss of the shoreline and destruction of property. Beach nourishment appears to be the only economically feasible solution to counteract the extensive erosion.

  4. Extracting magnetic cluster size and its distributions in advanced perpendicular recording media with shrinking grain size using small angle x-ray scattering

    SciTech Connect (OSTI)

    Mehta, Virat; Ikeda, Yoshihiro; Takano, Ken; Terris, Bruce D.; Hellwig, Olav; Wang, Tianhan; Wu, Benny; Graves, Catherine; Dürr, Hermann A.; Scherz, Andreas; Stöhr, Jo

    2015-05-18

    We analyze the magnetic cluster size (MCS) and magnetic cluster size distribution (MCSD) in a variety of perpendicular magnetic recording (PMR) media designs using resonant small angle x-ray scattering at the Co L{sub 3} absorption edge. The different PMR media flavors considered here vary in grain size between 7.5 and 9.5 nm as well as in lateral inter-granular exchange strength, which is controlled via the segregant amount. While for high inter-granular exchange, the MCS increases rapidly for grain sizes below 8.5 nm, we show that for increased amount of segregant with less exchange the MCS remains relatively small, even for grain sizes of 7.5 and 8 nm. However, the MCSD still increases sharply when shrinking grains from 8 to 7.5 nm. We show evidence that recording performance such as signal-to-noise-ratio on the spin stand correlates well with the product of magnetic cluster size and magnetic cluster size distribution.

  5. Pseudopotential approach for dust acoustic solitary waves in dusty plasmas with kappa-distributed ions and electrons and dust grains having power law size distribution

    SciTech Connect (OSTI)

    Banerjee, Gadadhar; Maitra, Sarit

    2015-04-15

    Sagdeev's pseudopotential method is used to study small as well as arbitrary amplitude dust acoustic solitons in a dusty plasma with kappa distributed electrons and ions with dust grains having power law size distribution. The existence of potential well solitons has been shown for suitable parametric region. The criterion for existence of soliton is derived in terms of upper and lower limit for Mach numbers. The numerical results show that the size distribution can affect the existence as well as the propagation characteristics of the dust acoustic solitons. The effect of kappa distribution is also highlighted.

  6. THE IMPORTANCE OF PHYSICAL MODELS FOR DERIVING DUST MASSES AND GRAIN SIZE DISTRIBUTIONS IN SUPERNOVA EJECTA. I. RADIATIVELY HEATED DUST IN THE CRAB NEBULA

    SciTech Connect (OSTI)

    Temim, Tea; Dwek, Eli, E-mail: tea.temim@nasa.gov [Observational Cosmology Lab, Code 665, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2013-09-01

    Recent far-infrared (IR) observations of supernova remnants (SNRs) have revealed significantly large amounts of newly condensed dust in their ejecta, comparable to the total mass of available refractory elements. The dust masses derived from these observations assume that all the grains of a given species radiate at the same temperature, regardless of the dust heating mechanism or grain radius. In this paper, we derive the dust mass in the ejecta of the Crab Nebula, using a physical model for the heating and radiation from the dust. We adopt a power-law distribution of grain sizes and two different dust compositions (silicates and amorphous carbon), and calculate the heating rate of each dust grain by the radiation from the pulsar wind nebula. We find that the grains attain a continuous range of temperatures, depending on their size and composition. The total mass derived from the best-fit models to the observed IR spectrum is 0.019-0.13 M{sub Sun }, depending on the assumed grain composition. We find that the power-law size distribution of dust grains is characterized by a power-law index of 3.5-4.0 and a maximum grain size larger than 0.1 {mu}m. The grain sizes and composition are consistent with what is expected for dust grains formed in a Type IIP supernova (SN). Our derived dust mass is at least a factor of two less than the mass reported in previous studies of the Crab Nebula that assumed more simplified two-temperature models. These models also require a larger mass of refractory elements to be locked up in dust than was likely available in the ejecta. The results of this study show that a physical model resulting in a realistic distribution of dust temperatures can constrain the dust properties and affect the derived dust masses. Our study may also have important implications for deriving grain properties and mass estimates in other SNRs and for the ultimate question of whether SNe are major sources of dust in the Galactic interstellar medium and in

  7. Magnetoresistance of polycrystalline gadolinium with varying grain size

    SciTech Connect (OSTI)

    Chakravorty, Manotosh Raychaudhuri, A. K.

    2015-01-21

    In this paper, we report a study of evolution of low field magnetoresistance (MR) of Gadolinium as the grain size in the sample is changed from few microns (∼4 μm) to the nanoscopic regime (∼35 nm). The low field MR has a clear effect on varying grain size. In large grain sample (few μm), the magnetic domains are controlled by local anisotropy field determined mainly by the magnetocrystalline anisotropy. The low field MR clearly reflects the temperature dependence of the magnetocrystalline anisotropy. For decreasing gain size, the contribution of spin disorder at the grain boundary increases and enhances the local anisotropy field.

  8. Orientation influence on grain size-effects in ultrafine-grained magnesium

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

    Fan, Haidong; Aubry, Sylvie; Arsenlis, A.; El-Awady, Jaafar

    2014-11-08

    The mechanical behavior of ultrafine-grained magnesium was studied by discrete dislocation dynamics (DDD) simulations. Our results show basal slip yields a strong size effect, while prismatic and pyramidal slips produce a weak one. We developed a new size-strength model that considers dislocation transmission across grain boundaries. Good agreement between this model, current DDD simulations and previous experiments is observed. These results reveal that the grain size effect depends on 3 factors: Peierls stress, dislocation source strength and grain boundary strength.

  9. The influence of aluminum grain size on alumina nanoporous structure

    SciTech Connect (OSTI)

    Feil, A. F.; Costa, M. V. da; Amaral, L.; Teixeira, S. R.; Migowski, P.; Dupont, J.; Machado, G.; Peripolli, S. B.

    2010-01-15

    An approach to control the interpore distances and nanopore diameters of 150-nm-thick thin aluminum films is reported here. The Al thin films were grown by sputtering on p-type silicon substrate and anodized with a conventional anodization process in a phosphoric acid solution. It was found that interpore distance and pore diameter are related to the aluminum grain size and can be controlled by annealing. The grain contours limit the sizes of alumina cells. This mechanism is valid for grain sizes supporting only one alumina cell and consequently only one pore.

  10. ARM - Measurement - Particle size distribution

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

    size distribution ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Particle size distribution The number of particles present in any given volume of air within a specified size range. Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available

  11. Phosphorus removal from slow-cooled steelmaking slags: Grain size determination and liberation studies

    SciTech Connect (OSTI)

    Fregeau-Wu, E.; Iwasaki, I.

    1995-07-01

    The major obstacle in recycling steelmaking slags to the blast furnace is their phosphorus content. Removal of the phosphorus, which is primarily associated with the silicate and phosphate phases, would allow for greater recycle of these slags for their iron, manganese, and lime contents. Calculations show that separation of the silicates from the oxide phases would remove nearly 90% of the phosphorus from the slag. The variable grain size of the as-received slag made liberation by fine grinding difficult. Therefore, slow-cooling experiments were undertaken to improve the grain size distribution. The grain size distributions were determined using in-situ image analysis. The samples were ground to their apparent liberation size and high gradient magnetic separation was used to separate the magnetic oxides from the nonmagnetic silicates and phosphates. Liberation analysis and modeling was performed on selected separation products for discussion of benefication characteristics.

  12. Grain boundary character distribution in nanocrystalline metals produced by different processing routes

    SciTech Connect (OSTI)

    Bober, David B.; Kumar, Mukal; Rupert, Timothy J.; Khalajhedayati, Amirhossein

    2015-12-28

    Nanocrystalline materials are defined by their fine grain size, but details of the grain boundary character distribution should also be important. Grain boundary character distributions are reported for ball-milled, sputter-deposited, and electrodeposited Ni and Ni-based alloys, all with average grain sizes of ~20 nm, to study the influence of processing route. The two deposited materials had nearly identical grain boundary character distributions, both marked by a Σ3 length percentage of 23 to 25 pct. In contrast, the ball-milled material had only 3 pct Σ3-type grain boundaries and a large fraction of low-angle boundaries (16 pct), with the remainder being predominantly random high angle (73 pct). Furthermore, these grain boundary character measurements are connected to the physical events that control their respective processing routes. Consequences for material properties are also discussed with a focus on nanocrystalline corrosion. As a whole, the results presented here show that grain boundary character distribution, which has often been overlooked in nanocrystalline metals, can vary significantly and influence material properties in profound ways.

  13. Grain boundary character distribution in nanocrystalline metals produced by different processing routes

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

    Bober, David B.; Kumar, Mukal; Rupert, Timothy J.; Khalajhedayati, Amirhossein

    2015-12-28

    Nanocrystalline materials are defined by their fine grain size, but details of the grain boundary character distribution should also be important. Grain boundary character distributions are reported for ball-milled, sputter-deposited, and electrodeposited Ni and Ni-based alloys, all with average grain sizes of ~20 nm, to study the influence of processing route. The two deposited materials had nearly identical grain boundary character distributions, both marked by a Σ3 length percentage of 23 to 25 pct. In contrast, the ball-milled material had only 3 pct Σ3-type grain boundaries and a large fraction of low-angle boundaries (16 pct), with the remainder being predominantlymore » random high angle (73 pct). Furthermore, these grain boundary character measurements are connected to the physical events that control their respective processing routes. Consequences for material properties are also discussed with a focus on nanocrystalline corrosion. As a whole, the results presented here show that grain boundary character distribution, which has often been overlooked in nanocrystalline metals, can vary significantly and influence material properties in profound ways.« less

  14. Pore size distribution and accessible pore size distribution...

    Office of Scientific and Technical Information (OSTI)

    both rank and type (expressed as either hydrogen or vitrinite content) in the size range ... Subject: 01 COAL, LIGNITE, AND PEAT; 03 NATURAL GAS; 08 HYDROGEN; AMBIENT TEMPERATURE; ...

  15. ARM - Measurement - Hydrometeor Size Distribution

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

    of hydrometeors observed in a given size range. Categories Atmospheric State, Cloud Properties Instruments The above measurement is considered scientifically relevant for the...

  16. LUNAR DUST GRAIN CHARGING BY ELECTRON IMPACT: DEPENDENCE OF THE SURFACE POTENTIAL ON THE GRAIN SIZE

    SciTech Connect (OSTI)

    Nemecek, Z.; Pavlu, J.; Safrankova, J.; Beranek, M.; Richterova, I.; Vaverka, J.; Mann, I.

    2011-09-01

    The secondary electron emission is believed to play an important role for the dust charging at and close to the lunar surface. However, our knowledge of emission properties of the dust results from model calculations and rather rare laboratory investigations. The present paper reports laboratory measurements of the surface potential on Lunar Highlands Type regolith simulants with sizes between 0.3 and 3 {mu}m in an electron beam with energy below 700 eV. This investigation is focused on a low-energy part, i.e., {<=}100 eV. We found that the equilibrium surface potential of this simulant does not depend on the grain size in our ranges of grain dimensions and the beam energies, however, it is a function of the primary electron beam energy. The measurements are confirmed by the results of the simulation model of the secondary emission from the spherical samples. Finally, we compare our results with those obtained in laboratory experiments as well as those inferred from in situ observations.

  17. Influence of grain size on the constitutive response and substructure evolution of MONEL 400

    SciTech Connect (OSTI)

    Gray, G.T. III, Chen, S.R.; Vecchio, K.S.

    1999-05-01

    The influence of grain size on the constitutive behavior (strain-rate and temperature dependence of the yield stress and strain hardening) and substructure evolution of MONEL 400 was investigated. Increasing the grain size from 9.5 to 202 {micro}m was seen to reduce the quasi-static yield strength from 290 to 115 MPa, while having a minimal effect on the work-hardening response. Increasing the strain rate from quasi-static to dynamic strain rates (3000 s{sup {minus}1}) was seen to increase the yield and overall flow-stress levels, but has no effect on the strong grain-size dependency exhibited of this alloy. The persistent influence of grain size to large strains is inconsistent with previous d{sup {minus}1/2} pileup grain-size modeling in the literature, which predicts convergence at large strains. Substructure evolution differences between the grain interiors and adjacent to grain boundaries supports differential defect storage processes which are consistent with previously published work-hardening d{sup {minus}1} modeling arguments for grain size-dependent strengthening in polycrystals. The integration of grain-size dependency into constitutive modeling using the mechanical threshold stress (MTS) model is discussed. The MTS model is shown to provide a robust constitutive description capturing yielding, large-strain work hardening, and grain-size effects simultaneously. The MTS model is, additionally, shown to satisfactorily address the experimentally observed transients due to strain-rate or temperature-path dependency.

  18. Grain size dependent mechanical properties of nanocrystalline diamond films grown by hot-filament CVD

    SciTech Connect (OSTI)

    Wiora, M; Bruehne, K; Floeter, A; Gluche, P; Willey, T M; Kucheyev, S O; Van Buuren, A W; Hamza, A V; Biener, J; Fecht, H

    2008-08-01

    Nanocrystalline diamond (NCD) films with a thickness of {approx}6 {micro}m and with average grain sizes ranging from 60 to 9 nm were deposited on silicon wafers using a hot-filament chemical vapor deposition (HFCVD) process. These samples were then characterized with the goal to identify correlations between grain size, chemical composition and mechanical properties. The characterization reveals that our films are phase pure and exhibit a relatively smooth surface morphology. The levels of sp{sup 2}-bonded carbon and hydrogen impurities are low, and showed a systematic variation with the grain size. The hydrogen content increases with decreasing grain size, whereas the sp{sup 2} carbon content decreases with decreasing grain size. The material is weaker than single crystalline diamond, and both stiffness and hardness decrease with decreasing grain size. These trends suggest gradual changes of the nature of the grain boundaries, from graphitic in the case of the 60 nm grain size material to hydrogen terminated sp{sup 3} carbon for the 9 nm grain size material. The films exhibit low levels of internal stress and freestanding structures with a length of several centimeters could be fabricated without noticeable bending.

  19. Particle size distribution instrument. Topical report 13

    SciTech Connect (OSTI)

    Okhuysen, W.; Gassaway, J.D.

    1995-04-01

    The development of an instrument to measure the concentration of particles in gas is described in this report. An in situ instrument was designed and constructed which sizes individual particles and counts the number of occurrences for several size classes. Although this instrument was designed to detect the size distribution of slag and seed particles generated at an experimental coal-fired magnetohydrodynamic power facility, it can be used as a nonintrusive diagnostic tool for other hostile industrial processes involving the formation and growth of particulates. Two of the techniques developed are extensions of the widely used crossed beam velocimeter, providing simultaneous measurement of the size distribution and velocity of articles.

  20. ARM - Measurement - Cloud particle size distribution

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

    from you Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud particle size distribution The number of cloud particles present in any given volume of air...

  1. Effect of particles attachment to multi-sized dust grains present in electrostatic sheaths of discharge plasmas

    SciTech Connect (OSTI)

    Zaham, B.; Tahraoui, A. Chekour, S.; Benlemdjaldi, D.

    2014-12-15

    The loss of electrons and ions due to their attachment to a Gauss-distributed sizes of dust grains present in electrostatic sheaths of discharge plasmas is investigated. A uni-dimensional, unmagnetized, and stationary multi-fluid model is proposed. Forces acting on the dust grain along with its charge are self-consistently calculated, within the limits of the orbit motion limited model. The dynamic analysis of dust grains shows that the contribution of the neutral drag force in the net force acting on the dust grain is negligible, whereas the contribution of the gravity force is found considerable only for micrometer particles. The dust grains trapping is only possible when the electrostatic force is balanced by the ion drag and the gravity forces. This trapping occurs for a limited radius interval of micrometer dust grains, which is around the most probable dust grain radius. The effect of electron temperature and ion density at the sheath edge is also discussed. It is shown that the attachment of particles reduces considerably the sheath thickness and induces dust grain deceleration. The increase of the lower limit as well as the upper limit of the dust radius reduces also the sheath thickness.

  2. Apparatus and method for the determination of grain size in thin films

    DOE Patents [OSTI]

    Maris, Humphrey J

    2001-01-01

    A method for the determination of grain size in a thin film sample comprising the steps of measuring first and second changes in the optical response of the thin film, comparing the first and second changes to find the attenuation of a propagating disturbance in the film and associating the attenuation of the disturbance to the grain size of the film. The second change in optical response is time delayed from the first change in optical response.

  3. Apparatus and method for the determination of grain size in thin films

    DOE Patents [OSTI]

    Maris, Humphrey J

    2000-01-01

    A method for the determination of grain size in a thin film sample comprising the steps of measuring first and second changes in the optical response of the thin film, comparing the first and second changes to find the attenuation of a propagating disturbance in the film and associating the attenuation of the disturbance to the grain size of the film. The second change in optical response is time delayed from the first change in optical response.

  4. Composition and grain size effects on the structural and mechanical properties of CuZr nanoglasses

    SciTech Connect (OSTI)

    Adibi, Sara [Institute of High Performance Computing, A*STAR, 138632 Singapore (Singapore); Mechanical Engineering Department, National University of Singapore, 117576 Singapore (Singapore); Branicio, Paulo S., E-mail: branicio@ihpc.a-star.edu.sg; Zhang, Yong-Wei [Institute of High Performance Computing, A*STAR, 138632 Singapore (Singapore); Joshi, Shailendra P., E-mail: Shailendra@nus.edu.sg [Mechanical Engineering Department, National University of Singapore, 117576 Singapore (Singapore)

    2014-07-28

    Nanoglasses (NGs), metallic glasses (MGs) with a nanoscale grain structure, have the potential to considerably increase the ductility of traditional MGs while retaining their outstanding mechanical properties. We investigated the effects of composition on the structural and mechanical properties of CuZr NG films with grain sizes between 3 to 15?nm using molecular dynamics simulations. Results indicate a transition from localized shear banding to homogeneous superplastic flow with decreasing grain size, although the critical average grain size depends on composition: 5?nm for Cu{sub 36}Zr{sub 64} and 3?nm for Cu{sub 64}Zr{sub 36}. The flow stress of the superplastic NG at different compositions follows the trend of the yield stress of the parent MG, i.e., Cu{sub 36}Zr{sub 64} yield/flow stress: 2.54?GPa/1.29?GPa and Cu{sub 64}Zr{sub 36} yield/flow stress: 3.57?GPa /1.58?GPa. Structural analysis indicates that the differences in mechanical behavior as a function of composition are rooted at the distinct statistics of prominent atomic Voronoi polyhedra. The mechanical behavior of NGs is also affected by the grain boundary thickness and the fraction of atoms at interfaces for a given average grain size. The results suggest that the composition dependence of the mechanical behavior of NGs follows that of their parent MGs, e.g., a stronger MG will generate a stronger NG, while the intrinsic tendency for homogeneous deformation occurring at small grain size is not affected by composition.

  5. Effect of a polynomial arbitrary dust size distribution on dust acoustic solitons

    SciTech Connect (OSTI)

    Ishak-Boushaki, M.; Djellout, D.; Annou, R.

    2012-07-15

    The investigation of dust-acoustic solitons when dust grains are size-distributed and ions adiabatically heated is conducted. The influence of an arbitrary dust size-distribution described by a polynomial function on the properties of dust acoustic waves is investigated. An energy-like integral equation involving Sagdeev potential is derived. The solitary solutions are shown to undergo a transformation into cnoidal ones under some physical conditions. The dust size-distribution can significantly affect both lower and upper critical Mach numbers for both solitons and cnoidal solutions.

  6. Parameterizing Size Distribution in Ice Clouds

    SciTech Connect (OSTI)

    DeSlover, Daniel; Mitchell, David L.

    2009-09-25

    PARAMETERIZING SIZE DISTRIBUTIONS IN ICE CLOUDS David L. Mitchell and Daniel H. DeSlover ABSTRACT An outstanding problem that contributes considerable uncertainty to Global Climate Model (GCM) predictions of future climate is the characterization of ice particle sizes in cirrus clouds. Recent parameterizations of ice cloud effective diameter differ by a factor of three, which, for overcast conditions, often translate to changes in outgoing longwave radiation (OLR) of 55 W m-2 or more. Much of this uncertainty in cirrus particle sizes is related to the problem of ice particle shattering during in situ sampling of the ice particle size distribution (PSD). Ice particles often shatter into many smaller ice fragments upon collision with the rim of the probe inlet tube. These small ice artifacts are counted as real ice crystals, resulting in anomalously high concentrations of small ice crystals (D < 100 m) and underestimates of the mean and effective size of the PSD. Half of the cirrus cloud optical depth calculated from these in situ measurements can be due to this shattering phenomenon. Another challenge is the determination of ice and liquid water amounts in mixed phase clouds. Mixed phase clouds in the Arctic contain mostly liquid water, and the presence of ice is important for determining their lifecycle. Colder high clouds between -20 and -36 oC may also be mixed phase but in this case their condensate is mostly ice with low levels of liquid water. Rather than affecting their lifecycle, the presence of liquid dramatically affects the cloud optical properties, which affects cloud-climate feedback processes in GCMs. This project has made advancements in solving both of these problems. Regarding the first problem, PSD in ice clouds are uncertain due to the inability to reliably measure the concentrations of the smallest crystals (D < 100 m), known as the small mode. Rather than using in situ probe measurements aboard aircraft, we employed a treatment of ice cloud

  7. On Techniques to Characterize and Correlate Grain Size, Grain Boundary Orientation and the Strength of the SiC Layer of TRISO Coated Particles: A Preliminary Study

    SciTech Connect (OSTI)

    I.J.van Rooyen; J.L. Dunzik Gougar; T. Trowbridge; Philip M van Rooyen

    2012-10-01

    The mechanical properties of the silicon carbide (SiC) layer of the TRi-ISOtropic (TRISO) coated particle (CP) for high temperature gas reactors (HTGR) are performance parameters that have not yet been standardized by the international HTR community. Presented in this paper are the results of characterizing coated particles to reveal the effect of annealing temperature (1000 to 2100C) on the strength and grain size of unirradiated coated particles. This work was further expanded to include possible relationships between the grain size and strength values. The comparative results of two strength measurement techniques and grain size measured by the Lineal intercept method are included. Preliminary grain boundary characterization results determined by electron backscatter diffraction (EBSD) are included. These results are also important for future fission product transport studies, as grain boundary diffusion is identified as a possible mechanism by which 110mAg, one of the fission activation products, might be released through intact SiC layers. Temperature is a parameter known to influence the grain size of SiC and therefore it is important to investigate the effect of high temperature annealing on the SiC grain size. Recommendations and future work will also be briefly discussed.

  8. Method to grow carbon thin films consisting entirely of diamond grains 3-5 nm in size and high-energy grain boundaries

    DOE Patents [OSTI]

    Carlisle, John A.; Auciello, Orlando; Birrell, James

    2006-10-31

    An ultrananocrystalline diamond (UNCD) having an average grain size between 3 and 5 nanometers (nm) with not more than about 8% by volume diamond having an average grain size larger than 10 nm. A method of manufacturing UNCD film is also disclosed in which a vapor of acetylene and hydrogen in an inert gas other than He wherein the volume ratio of acetylene to hydrogen is greater than 0.35 and less than 0.85, with the balance being an inert gas, is subjected to a suitable amount of energy to fragment at least some of the acetylene to form a UNCD film having an average grain size of 3 to 5 nm with not more than about 8% by volume diamond having an average grain size larger than 10 nm.

  9. Pore size distribution and accessible pore size distribution in bituminous coals

    SciTech Connect (OSTI)

    Sakurovs, Richard; He, Lilin; Melnichenko, Yuri B; Radlinski, Andrzej Pawell; Blach, Tomasz P

    2012-01-01

    The porosity and pore size distribution of coals determine many of their properties, from gas release to their behavior on carbonization, and yet most methods of determining pore size distribution can only examine a restricted size range. Even then, only accessible pores can be investigated with these methods. Small-angle neutron scattering (SANS) and ultra small-angle neutron scattering (USANS) are increasingly used to characterize the size distribution of all of the pores non-destructively. Here we have used USANS/SANS to examine 24 well-characterized bituminous and subbituminous coals: three from the eastern US, two from Poland, one from New Zealand and the rest from the Sydney and Bowen Basins in Eastern Australia, and determined the relationships of the scattering intensity corresponding to different pore sizes with other coal properties. The range of pore radii examinable with these techniques is 2.5 nm to 7 {micro}m. We confirm that there is a wide range of pore sizes in coal. The pore size distribution was found to be strongly affected by both rank and type (expressed as either hydrogen or vitrinite content) in the size range 250 nm to 7 {micro}m and 5 to 10 nm, but weakly in intermediate regions. The results suggest that different mechanisms control coal porosity on different scales. Contrast-matching USANS and SANS were also used to determine the size distribution of the fraction of the pores in these coals that are inaccessible to deuterated methane, CD{sub 4}, at ambient temperature. In some coals most of the small ({approx} 10 nm) pores were found to be inaccessible to CD{sub 4} on the time scale of the measurement ({approx} 30 min - 16 h). This inaccessibility suggests that in these coals a considerable fraction of inherent methane may be trapped for extended periods of time, thus reducing the effectiveness of methane release from (or sorption by) these coals. Although the number of small pores was less in higher rank coals, the fraction of total

  10. Measuring the Raindrop Size Distribution, ARM's Efforts at Darwin...

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

    the Raindrop Size Distribution, ARM's Efforts at Darwin and SGP Bartholomew, Mary Jane Brookhaven National Laboratory Category: Instruments ARM has purchased two impact...

  11. Pore-size-distribution of cationic polyacrylamide hydrogels. Progress report

    SciTech Connect (OSTI)

    Kremer, M.; Prausnitz, J.M.

    1992-06-01

    The pore size distribution of a AAm/MAPTAC (acrylamide copolymerized with (3-methacrylamidopropyl)trimethylammonium chloride) hydrogel was investigated using Kuga`s mixed-solute-exclusion method, taking into account the wall effect. A Brownian-motion model is also used. Results show the feasibility of determining pore-size distribution of porous materials using the mixed-solute-exclusion method in conjunction with solution of the Fredholm equation; good agreement was obtained with experiment, even for bimodal pore structures. However, different pore size distributions were calculated for the two different probe-solutes (Dextran and poly(ethylene glycol/oxide)). Future work is outlined. 32 figs, 25 refs.

  12. Pore-size-distribution of cationic polyacrylamide hydrogels

    SciTech Connect (OSTI)

    Kremer, M.; Prausnitz, J.M.

    1992-06-01

    The pore size distribution of a AAm/MAPTAC (acrylamide copolymerized with (3-methacrylamidopropyl)trimethylammonium chloride) hydrogel was investigated using Kuga's mixed-solute-exclusion method, taking into account the wall effect. A Brownian-motion model is also used. Results show the feasibility of determining pore-size distribution of porous materials using the mixed-solute-exclusion method in conjunction with solution of the Fredholm equation; good agreement was obtained with experiment, even for bimodal pore structures. However, different pore size distributions were calculated for the two different probe-solutes (Dextran and poly(ethylene glycol/oxide)). Future work is outlined. 32 figs, 25 refs.

  13. Size and grain morphology dependent magnetic behaviour of Co-doped ZnO

    SciTech Connect (OSTI)

    Vagadia, Megha; Ravalia, Ashish; Khachar, Uma; Solanki, P.S.; Doshi, R.R.; Rayaprol, S.; Kuberkar, D.G.

    2011-11-15

    Highlights: {yields} Structure and magnetic studies on Co-doped ZnO. {yields} Synthesis method dependent comparison of magnetic properties. {yields} Grain size and morphology affect the magnetic properties of Co-doped ZnO. -- Abstract: We have carried out a comparative study of structural, microstructural and magnetic properties of the two sets of Co-doped ZnO samples synthesized using solid state reaction and sol-gel method. Rietveld refinement of the X-ray diffraction data reveals single phase hexagonal wurtzite structure for all the samples, while the tunnelling electron microscopy measurements show the presence of nano-phase in the sol-gel grown Co-doped ZnO samples. It is found that, the microstructure strongly depends on the synthesis method adopted. Samples with higher Co-concentration synthesized by SSR route exhibit antiferromagnetism while SG grown Co-doped ZnO samples exhibit weak ferromagnetic behaviour. Improved magnetic phase in the SG grown samples has been attributed to the grain morphology.

  14. Evolution of droplet size distribution and autoconversion parameterization

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

    in turbulent clouds Evolution of droplet size distribution and autoconversion parameterization in turbulent clouds McGraw, Robert Brookhaven National Laboratory Liu, Yangang Brookhaven National Laboratory Category: Modeling Effects from turbulence-induced fluctuations in water vapor saturation on cloud droplet growth are examined using a Brownian diffusion model [McGraw and Liu, 2006]. The model predicts diffusive broadening of the droplet size distribution, tempered by enhanced

  15. Particle size and shape distributions of hammer milled pine

    SciTech Connect (OSTI)

    Westover, Tyler Lott; Matthews, Austin Colter; Williams, Christopher Luke; Ryan, John Chadron Benjamin

    2015-04-01

    Particle size and shape distributions impact particle heating rates and diffusion of volatized gases out of particles during fast pyrolysis conversion, and consequently must be modeled accurately in order for computational pyrolysis models to produce reliable results for bulk solid materials. For this milestone, lodge pole pine chips were ground using a Thomas-Wiley #4 mill using two screen sizes in order to produce two representative materials that are suitable for fast pyrolysis. For the first material, a 6 mm screen was employed in the mill and for the second material, a 3 mm screen was employed in the mill. Both materials were subjected to RoTap sieve analysis, and the distributions of the particle sizes and shapes were determined using digital image analysis. The results of the physical analysis will be fed into computational pyrolysis simulations to create models of materials with realistic particle size and shape distributions. This milestone was met on schedule.

  16. Concentrations and Size Distributions of Particulate Matter Emissions from

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

    Catalyzed Trap-Equipped Heavy-duty Diesel Vehicles Operating on Ultra-low Sulfur EC-D Fuel | Department of Energy Concentrations and Size Distributions of Particulate Matter Emissions from Catalyzed Trap-Equipped Heavy-duty Diesel Vehicles Operating on Ultra-low Sulfur EC-D Fuel Concentrations and Size Distributions of Particulate Matter Emissions from Catalyzed Trap-Equipped Heavy-duty Diesel Vehicles Operating on Ultra-low Sulfur EC-D Fuel 2002 DEER Conference Presentation: West Virginia

  17. The effect of a dust size distribution on electrostatic sheaths in unmagnetized dusty plasmas

    SciTech Connect (OSTI)

    Benlemdjaldi, D.; Tahraoui, A.; Hugon, R.; Bougdira, J.

    2013-04-15

    In this work, the structure of plasma sheaths in presence of dust particles with different sizes is investigated numerically in a multifluid framework, where the dust size distribution is modeled by Gauss' law. For this, we have established a 1D, stationary, unmagnetized, and weakly collisional electronegative dusty plasma sheath model. The electrons and negative ions are considered in a local thermodynamic equilibrium, therefore, described by a Boltzmann distribution. On the other hand, positive ions and dust grains are described by fluid equations. The charging process is described by the orbit motion limited model. It is shown that taking into account dust grains with different sizes reduces considerably the sheath thickness. The behavior of dust surface potential is not affected, but the dust charge number is reduced, as well as the electrostatic force. It results in a decrease of layered structure. The presence of negative ions makes the structure of the electrostatic potential more oscillatory. The other physical parameters are also analyzed and discussed.

  18. NEAMS FPL M2 Milestone Report: Development of a UO? Grain Size Model using Multicale Modeling and Simulation

    SciTech Connect (OSTI)

    Michael R Tonks; Yongfeng Zhang; Xianming Bai

    2014-06-01

    This report summarizes development work funded by the Nuclear Energy Advanced Modeling Simulation program's Fuels Product Line (FPL) to develop a mechanistic model for the average grain size in UO? fuel. The model is developed using a multiscale modeling and simulation approach involving atomistic simulations, as well as mesoscale simulations using INL's MARMOT code.

  19. Stress-dependent grain size evolution of nanocrystalline Ni-W and its impact on friction behavior

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

    Argibay, N.; Furnish, T. A.; Boyce, B. L.; Clark, B. G.; Chandross, M.

    2016-06-07

    The friction behavior of ultra-nanocrystalline Ni-W coatings was investigated. A critical stress threshold was identified below which friction remained low, and above which a time-dependent evolution toward higher friction behavior occurred. Founded on established plasticity models we propose a correlation between surface grain size and applied stress that can be used to predict the critical stress separating the two friction regimes. Lastly, this interpretation of plasticity models suggests that macro-scale low and high friction regimes are respectively associated with the nano-scale mechanisms of grain boundary and dislocation-mediated plasticity.

  20. Multi analysis of the effect of grain size on the dynamic behavior of microalloyed steels

    SciTech Connect (OSTI)

    Zurek, Anna K; Muszka, K; Majta, J; Wielgus, M

    2009-01-01

    This study presents some aspects of multiscale analysis and modeling of variously structured materials behavior in quasi-static and dynamic loading conditions. The investigation was performed for two different materials of common application: high strength microalloyed steel (HSLA, X65), and as a reference more ductile material, Ti-IF steel. The MaxStrain technique and one pass hot rolling processes were used to produce ultrafine-grained and coarse-grained materials. The efficiency and inhomogeneity of microstructure refinement were examined because of their important role in work hardening and the initiation and growth of fracture under tensile stresses. It is shown that the combination of microstructures characterized by their different features contributes to the dynamic behavior and final properties of the product. In particular, the role of solute segregation at grain boundaries as well as precipitation of carbonitrides in coarse and ultrafine-grained structures is assessed. The predicted mechanical response of ultrafine-grained structures, using modified KHL model is in reasonable agreement with the experiments. This is a result of proper representation of the role of dislocation structure and the grain boundary and their multiscale effects included in this model.

  1. Stabilized wide bandgap MAPbBrxI3-x perovskite by enhanced grain size and improved crystallinity

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

    Hu, Miao; Bi, Cheng; Yuan, Yongbo; Bai, Yang; Huang, Jinsong

    2015-12-07

    In this study, the light instability of CH3NH3PbIxBr3–x has been raised one of the biggest challenges for its application in tandem solar cells. Here we show that an improved crystallinity and grain size of CH3NH3PbIxBr3–x films could stabilize these materials under one sun illumination, improving both the efficiency and stability of the wide-bandgap perovskite solar cells.

  2. Method for measuring the size distribution of airborne rhinovirus

    SciTech Connect (OSTI)

    Russell, M.L.; Goth-Goldstein, R.; Apte, M.G.; Fisk, W.J.

    2002-01-01

    About 50% of viral-induced respiratory illnesses are caused by the human rhinovirus (HRV). Measurements of the concentrations and sizes of bioaerosols are critical for research on building characteristics, aerosol transport, and mitigation measures. We developed a quantitative reverse transcription-coupled polymerase chain reaction (RT-PCR) assay for HRV and verified that this assay detects HRV in nasal lavage samples. A quantitation standard was used to determine a detection limit of 5 fg of HRV RNA with a linear range over 1000-fold. To measure the size distribution of HRV aerosols, volunteers with a head cold spent two hours in a ventilated research chamber. Airborne particles from the chamber were collected using an Andersen Six-Stage Cascade Impactor. Each stage of the impactor was analyzed by quantitative RT-PCR for HRV. For the first two volunteers with confirmed HRV infection, but with mild symptoms, we were unable to detect HRV on any stage of the impactor.

  3. Effect of Engine-Out NOx Control Strategies on PM Size Distribution...

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

    Engine-Out NOx Control Strategies on PM Size Distribution in Heavy-Duty Diesel Engines Developed for 2010 Effect of Engine-Out NOx Control Strategies on PM Size Distribution in ...

  4. Grain size and texture effect on compression behavior of hot-extruded Mg-3Al-1Zn alloys at room temperature

    SciTech Connect (OSTI)

    Chang, L.L. [Department of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Wang, Y.N., E-mail: wynmm@dlut.edu.cn [Department of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Zhao, X. [Key laboratory for Anisotropy and Texture of Materials, Ministry of Education, Northeastern University, Shenyang 110005 (China); Qi, M. [Department of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China)

    2009-09-15

    Hot-extruded AZ31 alloy was subjected to compression at room temperature. The influence of grain size and grain orientation on the compression behavior of the specimens was examined by optical microscopy, compression test and X-ray diffraction. Abundant twins activated during compression of extruded AZ31 magnesium alloy. The hot extruded AZ31 magnesium alloys had a higher Hall-Petch slope for compression than that for tension.

  5. Machine vision based particle size and size distribution determination of airborne dust particles of wood and bark pellets

    SciTech Connect (OSTI)

    Igathinathane, C; Pordesimo, L.O.

    2009-08-01

    Dust management strategies in industrial environment, especially of airborne dust, require quantification and measurement of size and size distribution of the particles. Advanced specialized instruments that measure airborne particle size and size distribution apply indirect methods that involve light scattering, acoustic spectroscopy, and laser diffraction. In this research, we propose a simple and direct method of airborne dust particle dimensional measurement and size distribution analysis using machine vision. The method involves development of a user-coded ImageJ plugin that measures particle length and width and analyzes size distribution of particles based on particle length from high-resolution scan images. Test materials were airborne dust from soft pine wood sawdust pellets and ground pine tree bark pellets. Subsamples prepared by dividing the actual dust using 230 mesh (63 m) sieve were analyzed as well. A flatbed document scanner acquired the digital images of the dust particles. Proper sampling, layout of dust particles in singulated arrangement, good contrast smooth background, high resolution images, and accurate algorithm are essential for reliable analysis. A halo effect around grey-scale images ensured correct threshold limits. The measurement algorithm used Feret s diameter for particle length and pixel-march technique for particle width. Particle size distribution was analyzed in a sieveless manner after grouping particles according to their distinct lengths, and several significant dimensions and parameters of particle size distribution were evaluated. Results of the measurement and analysis were presented in textual and graphical formats. The developed plugin was evaluated to have a dimension measurement accuracy in excess of 98.9% and a computer speed of analysis of <8 s/image. Arithmetic mean length of actual wood and bark pellets airborne dust particles were 0.1138 0.0123 and 0.1181 0.0149 mm, respectively. The airborne dust particles of

  6. EVOLUTION OF SNOW LINE IN OPTICALLY THICK PROTOPLANETARY DISKS: EFFECTS OF WATER ICE OPACITY AND DUST GRAIN SIZE

    SciTech Connect (OSTI)

    Oka, Akinori; Nakamoto, Taishi; Ida, Shigeru, E-mail: akinorioka1@gmail.com, E-mail: nakamoto@geo.titech.ac.jp [Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Tokyo (Japan)

    2011-09-10

    Evolution of a snow line in an optically thick protoplanetary disk is investigated with numerical simulations. The ice-condensing region in the disk is obtained by calculating the temperature and the density with the 1+1D approach. The snow line migrates as the mass accretion rate ( M-dot ) in the disk decreases with time. Calculations are carried out from an early phase with high disk accretion rates ( M-dot {approx}10{sup -7} M{sub sun} yr{sup -1}) to a later phase with low disk accretion rates ( M-dot {approx}10{sup -12} M{sub sun} yr{sup -1}) using the same numerical method. It is found that the snow line moves inward for M-dot {approx}>10{sup -10} M{sub sun} yr{sup -1}, while it gradually moves outward in the later evolution phase with M-dot {approx}<10{sup -10} M{sub sun} yr{sup -1}. In addition to the silicate opacity, the ice opacity is taken into consideration. In the inward migration phase, the additional ice opacity increases the distance of the snow line from the central star by a factor of 1.3 for dust grains {approx}< 10 {mu}m in size and of 1.6 for {approx}> 100 {mu}m. It is inevitable that the snow line comes inside Earth's orbit in the course of the disk evolution if the viscosity parameter {alpha} is in the range 0.001-0.1, the dust-to-gas mass ratio is higher than a tenth of the solar abundance value, and the dust grains are smaller than 1 mm. The formation of water-devoid planetesimals in the terrestrial planet region seems to be difficult throughout the disk evolution, which imposes a new challenge to planet formation theory.

  7. Grain size tuning of nanostructured Cu{sub 2}O films through vapour phase supersaturation control and their characterization for practical applications

    SciTech Connect (OSTI)

    Anu, A.; Abdul Khadar, M.

    2015-09-15

    A strategy for creating nanostructured films is the alignment of nanoparticles into ordered superstructures as living organisms synthesize biomaterials with superior physical properties using nanoparticle building blocks. We synthesized nanostructured films of Cu{sub 2}O of variable grain size by establishing the condition of supersaturation for creation of nanoparticles of copper which deposited as nanograined films and which was then oxidized. This technique has the advantage of being compatible with conventional vacuum processes for electronic device fabrication. The Cu{sub 2}O film samples consisted of a secondary structure of spherical particles of almost uniform size, each particle being an agglomerate of primary nanocrystals. Fractal analysis of the AFM images of the samples is carried out for studying the aggregation mechanism. Grain size tuning of the nanostructured Cu{sub 2}O films has been studied using XRD, and micro-Raman and photoluminescence spectroscopy.

  8. THE SIZE DISTRIBUTION OF THE NEPTUNE TROJANS AND THE MISSING INTERMEDIATE-SIZED PLANETESIMALS

    SciTech Connect (OSTI)

    Sheppard, Scott S.; Trujillo, Chadwick A.

    2010-11-10

    We present an ultra-deep survey for Neptune Trojans using the Subaru 8.2 m and Magellan 6.5 m telescopes. The survey reached a 50% detection efficiency in the R band at m{sub R} = 25.7 mag and covered 49 deg{sup 2} of sky. m{sub R} = 25.7 mag corresponds to Neptune Trojans that are about 16 km in radius (assuming an albedo of 0.05). A paucity of smaller Neptune Trojans (radii < 45 km) compared with larger ones was found. The brightest Neptune Trojans appear to follow a steep power-law slope (q = 5 {+-} 1) similar to the brightest objects in the other known stable reservoirs such as the Kuiper Belt, Jupiter Trojans, and main belt asteroids. We find a roll-over for the Neptune Trojans that occurs around a radius of r = 45 {+-} 10 km (m{sub R} = 23.5 {+-} 0.3), which is also very similar to the other stable reservoirs. All the observed stable regions in the solar system show evidence for Missing Intermediate-Sized Planetesimals (MISPs). This indicates a primordial and not collisional origin, which suggests that planetesimal formation proceeded directly from small to large objects. The scarcity of intermediate- and smaller-sized Neptune Trojans may limit them as being a strong source for the short period comets.

  9. Multipass comminution process to produce precision wood particles of uniform size and shape with disrupted grain structure from wood chips

    DOE Patents [OSTI]

    Dooley, James H; Lanning, David N

    2014-05-27

    A process of comminution of wood chips (C) having a grain direction to produce a mixture of wood particles (P), wherein the wood chips are characterized by an average length dimension (L.sub.C) as measured substantially parallel to the grain, an average width dimension (W.sub.C) as measured normal to L.sub.C and aligned cross grain, and an average height dimension (H.sub.C) as measured normal to W.sub.C and L.sub.C, and wherein the comminution process comprises the step of feeding the wood chips in a direction of travel substantially randomly to the grain direction one or more times through a counter rotating pair of intermeshing arrays of cutting discs (D) arrayed axially perpendicular to the direction of wood chip travel.

  10. Comminution process to produce engineered wood particles of uniform size and shape with disrupted grain structure from veneer

    DOE Patents [OSTI]

    Dooley, James H; Lanning, David N

    2013-07-30

    Comminution process of wood veneer to produce wood particles, by feeding wood veneer in a direction of travel substantially normal to grain through a counter rotating pair of intermeshing arrays of cutting discs arrayed axially perpendicular to the direction of veneer travel, wherein the cutting discs have a uniform thickness (Td), to produce wood particles characterized by a length dimension (L) substantially equal to the Td and aligned substantially parallel to grain, a width dimension (W) normal to L and aligned cross grain, and a height dimension (H) substantially equal to the veneer thickness (Tv) and aligned normal to W and L, wherein the W.times.H dimensions define a pair of substantially parallel end surfaces with end checking between crosscut fibers.

  11. Comminution process to produce precision wood particles of uniform size and shape with disrupted grain structure from wood chips

    DOE Patents [OSTI]

    Dooley, James H.; Lanning, David N.

    2015-06-23

    A process of comminution of wood chips (C) having a grain direction to produce a mixture of wood particles (P), wherein the wood chips are characterized by an average length dimension (L.sub.C) as measured substantially parallel to the grain, an average width dimension (W.sub.C) as measured normal to L.sub.C and aligned cross grain, and an average height dimension (H.sub.C) as measured normal to W.sub.C and L.sub.C, wherein W.sub.C>L.sub.C, and wherein the comminution process comprises the step of feeding the wood chips in a direction of travel substantially randomly to the grain direction through a counter rotating pair of intermeshing arrays of cutting discs (D) arrayed axially perpendicular to the direction of wood chip travel, wherein the cutting discs have a uniform thickness (T.sub.D), and wherein at least one of L.sub.C, W.sub.C, and H.sub.C is less than T.sub.D.

  12. Comminution process to produce precision wood particles of uniform size and shape with disrupted grain structure from wood chips

    DOE Patents [OSTI]

    Dooley, James H; Lanning, David N

    2013-08-13

    A process of comminution of wood chips (C) having a grain direction to produce a mixture of wood particles (P), wherein the wood chips are characterized by an average length dimension (L.sub.C) as measured substantially parallel to the grain, an average width dimension (W.sub.C) as measured normal to L.sub.C and aligned cross grain, and an average height dimension (H.sub.C) as measured normal to W.sub.C and L.sub.C, and wherein the comminution process comprises the step of feeding the wood chips in a direction of travel substantially randomly to the grain direction through a counter rotating pair of intermeshing arrays of cutting discs (D) arrayed axially perpendicular to the direction of wood chip travel, wherein the cutting discs have a uniform thickness (T.sub.D), and wherein at least one of L.sub.C, W.sub.C, and H.sub.C is greater than T.sub.D.

  13. Measurements of Aerosol Charge and Size Distribution for Graphite, Gold, Palladium, and Silver Nanoparticles

    SciTech Connect (OSTI)

    Simones, Matthew P.; Gutti, Veera R.; Meyer, Ryan M.; Loyalka, Sudarshan K.

    2011-11-01

    The role of charge on aerosol evolution and hence the nuclear source term has been an issue of interest, and there is a need for both experimental techniques and modeling for quantifying this role. Our focus here is on further exploration of a tandem differential mobility analyzer (TDMA) technique to simultaneously measure both the size and charge (positive, negative and neutral) dependent aerosol distributions. We have generated graphite, gold, silver, and palladium nanoparticles (aerosol) using a spark generator. We measure the electrical mobility-size distributions for these aerosols using a TDMA, and from these data we deduce the full charge-size distributions. We observe asymmetry in the particle size distributions for negative and positive charges. This asymmetry could have a bearing on the dynamics of charged aerosols, indicating that the assumption of symmetry for size distributions of negatively and positively charged particles in source term simulations may not be always appropriate. Also, the experimental technique should find applications in measurements of aerosol rate processes that are affected by both particle charge and size (e.g. coagulation, deposition, resuspension), and hence in modeling and simulation of the nuclear source term.

  14. Abnormal grain growth in AISI 304L stainless steel

    SciTech Connect (OSTI)

    Shirdel, M.; Mirzadeh, H.; Parsa, M.H.

    2014-11-15

    The microstructural evolution during abnormal grain growth (secondary recrystallization) in 304L stainless steel was studied in a wide range of annealing temperatures and times. At relatively low temperatures, the grain growth mode was identified as normal. However, at homologous temperatures between 0.65 (850 °C) and 0.7 (900 °C), the observed transition in grain growth mode from normal to abnormal, which was also evident from the bimodality in grain size distribution histograms, was detected to be caused by the dissolution/coarsening of carbides. The microstructural features such as dispersed carbides were characterized by optical metallography, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, and microhardness. Continued annealing to a long time led to the completion of secondary recrystallization and the subsequent reappearance of normal growth mode. Another instance of abnormal grain growth was observed at homologous temperatures higher than 0.8, which may be attributed to the grain boundary faceting/defaceting phenomenon. It was also found that when the size of abnormal grains reached a critical value, their size will not change too much and the grain growth behavior becomes practically stagnant. - Highlights: • Abnormal grain growth (secondary recrystallization) in AISI 304L stainless steel • Exaggerated grain growth due to dissolution/coarsening of carbides • The enrichment of carbide particles by titanium • Abnormal grain growth due to grain boundary faceting at very high temperatures • The stagnancy of abnormal grain growth by annealing beyond a critical time.

  15. Stabilized wide bandgap MAPbBrxI3-x perovskite by enhanced grain size and improved crystallinity

    SciTech Connect (OSTI)

    Hu, Miao; Bi, Cheng; Yuan, Yongbo; Bai, Yang; Huang, Jinsong

    2015-12-07

    In this study, the light instability of CH3NH3PbIxBr3–x has been raised one of the biggest challenges for its application in tandem solar cells. Here we show that an improved crystallinity and grain size of CH3NH3PbIxBr3–x films could stabilize these materials under one sun illumination, improving both the efficiency and stability of the wide-bandgap perovskite solar cells.

  16. Ultrashort laser ablation of bulk copper targets: Dynamics and size distribution of the generated nanoparticles

    SciTech Connect (OSTI)

    Tsakiris, N.; Gill-Comeau, M.; Lewis, L. J.; Anoop, K. K.; Ausanio, G.; Bruzzese, R.; Amoruso, S.

    2014-06-28

    We address the role of laser pulse fluence on expansion dynamics and size distribution of the nanoparticles produced by irradiating a metallic target with an ultrashort laser pulse in a vacuum, an issue for which contrasting indications are present in the literature. To this end, we have carried out a combined theoretical and experimental analysis of laser ablation of a bulk copper target with ≈50 fs, 800 nm pulses, in an interval of laser fluencies going from few to several times the ablation threshold. On one side, molecular dynamics simulations, with two-temperature model, describe the decomposition of the material through the analysis of the evolution of thermodynamic trajectories in the material phase diagram, and allow estimating the size distribution of the generated nano-aggregates. On the other side, atomic force microscopy of less than one layer nanoparticles deposits on witness plates, and fast imaging of the nanoparticles broadband optical emission provide the corresponding experimental characterization. Both experimental and numerical findings agree on a size distribution characterized by a significant fraction (≈90%) of small nanoparticles, and a residual part (≈10%) spanning over a rather large size interval, evidencing a weak dependence of the nanoparticles sizes on the laser pulse fluence. Numerical and experimental findings show a good degree of consistency, thus suggesting that modeling can realistically support the search for experimental methods leading to an improved control over the generation of nanoparticles by ultrashort laser ablation.

  17. COLOR DEPENDENCE IN THE SIZE DISTRIBUTION OF MAIN BELT ASTEROIDS REVISITED

    SciTech Connect (OSTI)

    August, Tyler M.; Wiegert, Paul A.

    2013-06-15

    The size distribution of the asteroid belt is examined with 16956 main belt asteroids detected in data taken from the Canada-France-Hawaii Telescope Legacy Survey in two filters (g' and r'). The cumulative H (absolute magnitude) distribution is examined in both filters, and both match well to simple power laws down to H = 17, with slopes in rough agreement with those reported the literature. This implies that disruptive collisions between asteroids are gravitationally dominated down to at least this size, and probably sub-kilometer scales. The slopes of these distributions appear shallower in the outer belt than the inner belt, and the g' distributions appear slightly steeper than the r'. The slope shallowing in the outer belt may reflect a real compositional difference: the inner asteroid belt has been suggested to consist mostly of stony and/or metallic S-type asteroids, whereas carbonaceous C-types are thought to be more prevalent further from the Sun. No waves are seen in the size distribution above H = 15. Since waves are expected to be produced at the transition from gravitationally-dominated to internal strength-dominated collisions, their absence here may imply that the transition occurs at sub-kilometer scales, much smaller than the H = 17 (diameter {approx} 1.6 km) cutoff of this study.

  18. Pore size distribution, strength, and microstructure of portland cement paste containing metal hydroxide waste

    SciTech Connect (OSTI)

    Majid, Z.A.; Mahmud, H.; Shaaban, M.G.

    1996-12-31

    Stabilization/solidification of hazardous wastes is used to convert hazardous metal hydroxide waste sludge into a solid mass with better handling properties. This study investigated the pore size development of ordinary portland cement pastes containing metal hydroxide waste sludge and rice husk ash using mercury intrusion porosimetry. The effects of acre and the addition of rice husk ash on pore size development and strength were studied. It was found that the pore structures of mixes changed significantly with curing acre. The pore size shifted from 1,204 to 324 {angstrom} for 3-day old cement paste, and from 956 to 263 {angstrom} for a 7-day old sample. A reduction in pore size distribution for different curing ages was also observed in the other mixtures. From this limited study, no conclusion could be made as to any correlation between strength development and porosity. 10 refs., 6 figs., 3 tabs.

  19. SIZE DISTRIBUTION AND RATE OF PRODUCTION OF AIRBORNE PARTICULATE MATTER GENERATED DURING METAL CUTTING

    SciTech Connect (OSTI)

    M.A. Ebadian, Ph.D.; S.K. Dua, Ph.D., C.H.P.; Hillol Guha, Ph.D.

    2001-01-01

    During deactivation and decommissioning activities, thermal cutting tools, such as plasma torch, laser, and gasoline torch, are used to cut metals. These activities generate fumes, smoke and particulates. These airborne species of matter, called aerosols, may be inhaled if suitable respiratory protection is not used. Inhalation of the airborne metallic aerosols has been reported to cause ill health effects, such as acute respiratory syndrome and chromosome damage in lymphocytes. In the nuclear industry, metals may be contaminated with radioactive materials. Cutting these metals, as in size reduction of gloveboxes and tanks, produces high concentrations of airborne transuranic particles. Particles of the respirable size range (size < 10 {micro}m) deposit in various compartments of the respiratory tract, the fraction and the site in the respiratory tract depending on the size of the particles. The dose delivered to the respiratory tract depends on the size distribution of the airborne particulates (aerosols) and their concentration and radioactivity/toxicity. The concentration of airborne particulate matter in an environment is dependent upon the rate of their production and the ventilation rate. Thus, measuring aerosol size distribution and generation rate is important for (1) the assessment of inhalation exposures of workers, (2) the selection of respiratory protection equipment, and (3) the design of appropriate filtration systems. Size distribution of the aerosols generated during cutting of different metals by plasma torch was measured. Cutting rates of different metals, rate of generation of respirable mass, as well as the fraction of the released kerf that become respirable were determined. This report presents results of these studies. Measurements of the particles generated during cutting of metal plates with a plasma arc torch revealed the presence of particles with mass median aerodynamic diameters of particles close to 0.2 {micro}m, arising from

  20. Size and spacial distribution of micropores in SBA-15 using CM-SANS

    SciTech Connect (OSTI)

    Pollock, Rachel A; Walsh, Brenna R; Fry, Jason A; Ghampson, Tyrone; Centikol, Ozgul; Melnichenko, Yuri B; Kaiser, Helmut; Pynn, Roger; Frederick, Brian G

    2011-01-01

    Diffraction intensity analysis of small-angle neutron scattering measurements of dry SBA-15 have been combined with nonlocal density functional theory (NLDFT) analysis of nitrogen desorption isotherms to characterize the micropore, secondary mesopore, and primary mesopore structure. The radial dependence of the scattering length density, which is sensitive to isolated surface hydroxyls, can only be modeled if the NLDFT pore size distribution is distributed relatively uniformly throughout the silica framework, not localized in a 'corona' around the primary mesopores. Contrast matching-small angle neutron scattering (CM-SANS) measurements, using water, decane, tributylamine, cyclohexane, and isooctane as direct probes of the size of micropores indicate that the smallest pores in SBA-15 have diameter between 5.7 and 6.2 {angstrom}. Correlation of the minimum pore size with the onset of the micropore size distribution provides direct evidence that the shape of the smallest micropores is cylinderlike, which is consistent with their being due to unraveling of the polymer template.

  1. OPTIMIZATION OF COMMINUTION CIRCUIT THROUGHPUT AND PRODUCT SIZE DISTRIBUTION BY SIMULATION AND CONTROL

    SciTech Connect (OSTI)

    H.J. Walqui; T.C. Eisele; S.K. Kawatra

    2003-07-01

    The goal of this project is to improve energy efficiency of industrial crushing and grinding operations (comminution). Mathematical models of the comminution process are being used to study methods for optimizing the product size distribution, so that the amount of excessively fine material produced can be minimized. The goal is to save energy by reducing the amount of material that is ground below the target size, while simultaneously reducing the quantity of materials wasted as ''slimes'' that are too fine to be useful. This will be accomplished by: (1) modeling alternative circuit arrangements to determine methods for minimizing overgrinding, and (2) determining whether new technologies, such as high-pressure roll crushing, can be used to alter particle breakage behavior to minimize fines production.

  2. Platinum nanoparticle during electrochemical hydrogen evolution: Adsorbate distribution, active reaction species, and size effect

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

    Tan, Teck L.; Wang, Lin -Lin; Zhang, Jia; Johnson, Duane D.; Bai, Kewu

    2015-03-02

    For small Pt nanoparticles (NPs), catalytic activity is, as observed, adversely affected by size in the 1–3 nm range. We elucidate, via first-principles-based thermodynamics, the operation H* distribution and cyclic voltammetry (CV) during the hydrogen evolution reaction (HER) across the electrochemical potential, including the underpotential region (U ≤ 0) that is difficult to assess in experiment. We consider multiple adsorption sites on a 1 nm Pt NP model and show that the characteristic CV peaks from different H* species correspond well to experiment. We next quantify the activity contribution from each H* species to explain the adverse effect of size.more » From the resolved CV peaks at the standard hydrogen electrode potential (U = 0), we first deduce that the active species for the HER are the partially covered (100)-facet bridge sites and the (111)-facet hollow sites. Upon evaluation of the reaction barriers at operation H* distribution and microkinetic modeling of the exchange current, we find that the nearest-neighbor (100)-facet bridge site pairs have the lowest activation energy and contribute to ~75% of the NP activity. Edge bridge sites (fully covered by H*) per se are not active; however, they react with neighboring (100)-facet H* to account for ~18% of the activity, whereas (111)-facet hollow sites contribute little. As a result, extrapolating the relative contributions to larger NPs in which the ratio of facet-to-edge sites increases, we show that the adverse size effect of Pt NP HER activity kicks in for sizes below 2 nm.« less

  3. Platinum nanoparticle during electrochemical hydrogen evolution: Adsorbate distribution, active reaction species, and size effect

    SciTech Connect (OSTI)

    Tan, Teck L.; Wang, Lin -Lin; Zhang, Jia; Johnson, Duane D.; Bai, Kewu

    2015-03-02

    For small Pt nanoparticles (NPs), catalytic activity is, as observed, adversely affected by size in the 1–3 nm range. We elucidate, via first-principles-based thermodynamics, the operation H* distribution and cyclic voltammetry (CV) during the hydrogen evolution reaction (HER) across the electrochemical potential, including the underpotential region (U ≤ 0) that is difficult to assess in experiment. We consider multiple adsorption sites on a 1 nm Pt NP model and show that the characteristic CV peaks from different H* species correspond well to experiment. We next quantify the activity contribution from each H* species to explain the adverse effect of size. From the resolved CV peaks at the standard hydrogen electrode potential (U = 0), we first deduce that the active species for the HER are the partially covered (100)-facet bridge sites and the (111)-facet hollow sites. Upon evaluation of the reaction barriers at operation H* distribution and microkinetic modeling of the exchange current, we find that the nearest-neighbor (100)-facet bridge site pairs have the lowest activation energy and contribute to ~75% of the NP activity. Edge bridge sites (fully covered by H*) per se are not active; however, they react with neighboring (100)-facet H* to account for ~18% of the activity, whereas (111)-facet hollow sites contribute little. As a result, extrapolating the relative contributions to larger NPs in which the ratio of facet-to-edge sites increases, we show that the adverse size effect of Pt NP HER activity kicks in for sizes below 2 nm.

  4. Platinum nanoparticle during electrochemical hydrogen evolution: Adsorbate distribution, active reaction species, and size effect

    SciTech Connect (OSTI)

    Tan, Teck L.; Wang, Lin -Lin; Zhang, Jia; Johnson, Duane D.; Bai, Kewu

    2015-03-02

    For small Pt nanoparticles (NPs), catalytic activity is, as observed, adversely affected by size in the 13 nm range. We elucidate, via first-principles-based thermodynamics, the operation H* distribution and cyclic voltammetry (CV) during the hydrogen evolution reaction (HER) across the electrochemical potential, including the underpotential region (U ? 0) that is difficult to assess in experiment. We consider multiple adsorption sites on a 1 nm Pt NP model and show that the characteristic CV peaks from different H* species correspond well to experiment. We next quantify the activity contribution from each H* species to explain the adverse effect of size. From the resolved CV peaks at the standard hydrogen electrode potential (U = 0), we first deduce that the active species for the HER are the partially covered (100)-facet bridge sites and the (111)-facet hollow sites. Upon evaluation of the reaction barriers at operation H* distribution and microkinetic modeling of the exchange current, we find that the nearest-neighbor (100)-facet bridge site pairs have the lowest activation energy and contribute to ~75% of the NP activity. Edge bridge sites (fully covered by H*) per se are not active; however, they react with neighboring (100)-facet H* to account for ~18% of the activity, whereas (111)-facet hollow sites contribute little. As a result, extrapolating the relative contributions to larger NPs in which the ratio of facet-to-edge sites increases, we show that the adverse size effect of Pt NP HER activity kicks in for sizes below 2 nm.

  5. Pore size distribution and methane equilibrium conditions at Walker Ridge Block 313, northern Gulf of Mexico

    SciTech Connect (OSTI)

    Bihani, Abhishek; Daigle, Hugh; Cook, Ann; Glosser, Deborah; Shushtarian, Arash

    2015-12-15

    Coexistence of three methane phases (liquid (L), gas (G), hydrate (H)) in marine gas hydrate systems may occur according to in-situ pressure, temperature, salinity and pore size. In sediments with salinity close to seawater, a discrete zone of three-phase (3P) equilibrium may occur near the base of the regional hydrate stability zone (RHSZ) due to capillary effects. The existence of a 3P zone influences the location of the bottom-simulating reflection (BSR) and has implications for methane fluxes at the base of the RHSZ. We studied hydrate stability conditions in two wells, WR313-G and WR313-H, at Walker Ridge Block 313 in the northern Gulf of Mexico. We determined pore size distributions (PSD) by constructing a synthetic nuclear magnetic resonance (NMR) relaxation time distribution. Correlations were obtained by non-linear regression on NMR, gamma ray, and bulk density logs from well KC-151 at Keathley Canyon. The correlations enabled construction of relaxation time distributions for WR313-G and WR313-H, which were used to predict PSD through comparison with mercury injection capillary pressure measurements. With the computed PSD, L+H and L+G methane solubility was determined from in-situ pressure and temperature. The intersection of the L+G and L+H curves for various pore sizes allowed calculation of the depth range of the 3P equilibrium zone. As in previous studies at Blake Ridge and Hydrate Ridge, the top of the 3P zone moves upwards with increasing water depth and overlies the bulk 3P equilibrium depth. In clays at Walker Ridge, the predicted thickness of the 3P zone is approximately 35 m, but in coarse sands it is only a few meters due to the difference in absolute pore sizes and the width of the PSD. The thick 3P zone in the clays may explain in part why the BSR is only observed in the sand layers at Walker Ridge, although other factors may influence the presence or absence of a BSR.

  6. OPTIMIZATION OF COMMINUTION CIRCUIT THROUGHPUT AND PRODUCT SIZE DISTRIBUTION BY SIMULATION AND CONTROL

    SciTech Connect (OSTI)

    S.K. Kawatra; T.C. Eisele; H.J. Walqui

    2002-10-01

    The goal of this project is to improve energy efficiency of industrial crushing and grinding operations (comminution). Mathematical models of the comminution process are being used to study methods for optimizing he product size distribution, so that the amount of excessively fine material produced can be minimized. This will save energy by reducing the amount of material that is ground below the target size, and will also reduce the quantity of materials wasted as ''slimes'' that are too fine to be useful. This will be accomplished by: (1) modeling alternative circuit arrangements to determine methods for minimizing overgrinding, and (2) determining whether new technologies, such as high-pressure roll crushing, can be used to alter particle breakage behavior to minimize fines production. In the seventh quarter of this project, analysis of the plant operation identified sources of overgrinding in the circuit. Overgrinding was primarily caused by two effects: (1) The hydrocyclones used to close the circuit and remove fully-ground particles from the circuit were preferentially returning high-density ore particles to the secondary mills for regrinding even after they were already ground to pass the desired product size, and (2) The primary grinding mills were operating at less than full capacity, suggesting that a shift of grinding load to the primary mills could liberate more material before it reached the secondary mills, allowing more complete liberation with a coarser grind. Circuit modeling is underway to determine how best to modify the circuit to reduce these effects.

  7. Grain size effect on the giant dielectric constant of CaCu{sub 3}Ti{sub 4}O{sub 12} nanoceramics prepared by mechanosynthesis and spark plasma sintering

    SciTech Connect (OSTI)

    Ahmad, Mohamad M.; Yamada, Koji

    2014-04-21

    In the present work, CaCu{sub 3}Ti{sub 4}O{sub 12} (CCTO) nanoceramics with different grain sizes were prepared by spark plasma sintering (SPS) at different temperatures (SPS-800, SPS-900, SPS-975, and SPS-1050) of the mechanosynthesized nano-powder. Structural and microstructural properties were studied by XRD and field-emission scanning electron microscope measurements. The grain size of CCTO nanoceramics increases from 80?nm to ?200?nm for the ceramics sintered at 800?C and 975?C, respectively. Further increase of SPS temperature to 1050?C leads to micro-sized ceramics of 23??m. The electrical and dielectric properties of the investigated ceramics were studied by impedance spectroscopy. Giant dielectric constant was observed in CCTO nanoceramics. The dielectric constant increases with increasing the grain size of the nanoceramics with values of 8.3??10{sup 3}, 2.4??10{sup 4}, and 3.2??10{sup 4} for SPS-800, SPS-900, and SPS-975, respectively. For the micro-sized SPS-1050 ceramics, the dielectric constant dropped to 2.14??10{sup 4}. The dielectric behavior is interpreted within the internal barrier layer capacitance picture due to the electrical inhomogeneity of the ceramics. Besides the resistive grain boundaries that are usually observed in CCTO ceramics, domain boundaries appear as a second source of internal layers in the current nanoceramics.

  8. Crystallographic Characteristics of Grain Boundaries in Dense Yttria-Stabilized Zirconia

    SciTech Connect (OSTI)

    Lam Helmick; Shen J. Dillon; Kirk Gerdes; Randall Gemmen; Gregory S. Rohrer; Sridhar Seetharaman; Paul A. Salvador

    2010-04-01

    Grain-boundary plane, misorientation angle, grain size, and grain-boundary energy distributions were quantified using electron backscatter diffraction data for dense polycrystalline yttria-stabilized zirconia, to understand interfacial crystallography in solid oxide fuel cells. Tape-cast samples were sintered at 14501C for 4 h and annealed for at least 100 h between 8001C and 16501C. Distributions obtained from both three-dimensional (3D) reconstructions and stereological analyses of 2D sections demonstrated that the (100) boundary planes {(111)} have relative areas larger {smaller} than expected in a random distribution, and that the boundary plane distribution is inversely correlated to the boundary energy distribution.

  9. Deviations from the Gutenberg–Richter law on account of a random distribution of block sizes

    SciTech Connect (OSTI)

    Sibiryakov, B. P.

    2015-10-27

    This paper studies properties of a continuum with structure. The characteristic size of the structure governs the fact that difference relations are nonautomatically transformed into differential ones. It is impossible to consider an infinitesimal volume of a body, to which the major conservation laws could be applied, because the minimum representative volume of the body must contain at least a few elementary microstructures. The corresponding equations of motion are equations of infinite order, solutions of which include, along with usual sound waves, unusual waves with abnormally low velocities without a lower limit. It is shown that in such media weak perturbations can increase or decrease outside the limits. The number of complex roots of the corresponding dispersion equation, which can be interpreted as the number of unstable solutions, depends on the specific surface of cracks and is an almost linear dependence on a logarithmic scale, as in the seismological Gutenberg–Richter law. If the distance between one pore (crack) to another one is a random value with some distribution, we must write another dispersion equation and examine different scenarios depending on the statistical characteristics of the random distribution. In this case, there are sufficient deviations from the Gutenberg–Richter law and this theoretical result corresponds to some field and laboratory observations.

  10. Paleozoic expulsion in Bolivia-its influence on field size and distribution

    SciTech Connect (OSTI)

    Beer, J.A. ); Lopez, O. )

    1993-02-01

    Production within the Chaco Basin of Bolivia may be grouped into three areas: a northern area with several large fields (> 100 MMBOE), a central area nearly devoid of fields, and a southern area with numerous small fields. Models for the timing of hydrocarbon charge suggest that field size and distribution can be tied to spatial variation in the magnitude of a Paleozoic expulsion event. In the central Chaco, the Devonian Los Monos Formation source rock interval was deeply buried beneath a Carboniferous depocenter (1600 to 2000 m of sediment). An in-house thermal modeling program, constrained by vitrinite reflectance data, indicates that the source rock interval entered the oil window as early as 270 Ma. Basal Los Monos kerogen was completely converted to oil prior to Neogene trap formation, making oil accumulations impossible. In the southern Chaco, an intermediate Carboniferous thickness (1300-1600 m) resulted in a less pronounced pre-Cenzoic expulsion event. Expulsion began at 150 Ma, with 80% of basal Los Monos kerogen converted to oil prior to trap formation. The southern Chaco thus has limited exploration opportunity for large accumulations. The northern Chaco has a thin Carboniferous veneer (01300 m), and experienced insignificant pre-Cenozoic expulsion. As a result, 90% of the basal Los Monos kerogen was available for conversion to oil at the time of trap formation, and large accumulations were possible. Given the relationship between field presence/size and subsidence history, a Carboniferous isopach map is a powerful exploration tool. Where there is a thin Carboniferous section, unconverted Devonian source rocks are able to charge Cenozoic structures. One area that meets this criterium is the western Subandean, a relatively unexplored province adjacent to the Chaco Basin.

  11. Characterization of Vertical Velocity and Drop Size Distribution Parameters in Widespread Precipitation at ARM Facilities

    SciTech Connect (OSTI)

    Giangrande S. E.; Luke, E. P.; Kollias, P.

    2012-02-01

    Extended, high-resolution measurements of vertical air motion and median volume drop diameter D0 in widespread precipitation from three diverse Atmospheric Radiation Measurement Program (ARM) locations [Lamont, Oklahoma, Southern Great Plains site (SGP); Niamey, Niger; and Black Forest, Germany] are presented. The analysis indicates a weak (0-10 cm{sup -1}) downward air motion beneath the melting layer for all three regions, a magnitude that is to within the typical uncertainty of the retrieval methods. On average, the hourly estimated standard deviation of the vertical air motion is 0.25 m s{sup -1} with no pronounced vertical structure. Profiles of D0 vary according to region and rainfall rate. The standard deviation of 1-min-averaged D0 profiles for isolated rainfall rate intervals is 0.3-0.4 mm. Additional insights into the form of the raindrop size distribution are provided using available dual-frequency Doppler velocity observations at SGP. The analysis suggests that gamma functions better explain paired velocity observations and radar retrievals for the Oklahoma dataset. This study will be useful in assessing uncertainties introduced in the measurement of precipitation parameters from ground-based and spaceborne remote sensors that are due to small-scale variability.

  12. Arrays of Ru Nanoclusters with Narrow Size Distribution Templated by Monolayer Graphene on Ru

    SciTech Connect (OSTI)

    Sutter, P.; Sutter, E.; Albrecht, P.; Wang, B.; Bocquet M.-L.; Wu, L.; Zhu, Y.

    2011-09-01

    Ru nanoclusters self-assemble over macroscopic sample areas during vapor deposition of Ru on monolayer graphene (MLG) on Ru(0001). The Ru nanoclusters form arrays with a mean lateral cluster diameter of {approx} 20 {angstrom}, cluster heights of 1 or 2 ML, and a size distribution that remains nearly constant with increasing coverage. Combined scanning tunneling microscopy and density functional theory (DFT) show that the clusters are templated by the MLG/Ru(0001) moire unit cell and identify the preferred binding site of the clusters as the low fcc region of the moire. Cross-sectional transmission electron microscopy (TEM) and high-resolution TEM contrast simulations experimentally demonstrate that the interaction of the Ru clusters with the underlying MLG/Ru(0001) leads to a local lifting of the graphene layer of the template. DFT calculations confirm this mechanism of interaction of the Ru clusters with the strongly coupled MLG/Ru(0001). Weakening of the graphene-support coupling via oxygen intercalation is shown to have a major effect on the assembly of Ru nanocluster arrays. With a preferred binding site lacking on decoupled graphene, the Ru nanoclusters grow significantly larger, and clusters with 1 to 4 ML height can coexist.

  13. Relationship between Particle Size Distribution of Low-Rank Pulverized Coal and Power Plant Performance

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

    Ganguli, Rajive; Bandopadhyay, Sukumar

    2012-01-01

    Tmore » he impact of particle size distribution (PSD) of pulverized, low rank high volatile content Alaska coal on combustion related power plant performance was studied in a series of field scale tests. Performance was gauged through efficiency (ratio of megawatt generated to energy consumed as coal), emissions (SO 2 , NO x , CO), and carbon content of ash (fly ash and bottom ash).he study revealed that the tested coal could be burned at a grind as coarse as 50% passing 76 microns, with no deleterious impact on power generation and emissions.he PSD’s tested in this study were in the range of 41 to 81 percent passing 76 microns.here was negligible correlation between PSD and the followings factors: efficiency, SO 2 , NO x , and CO. Additionally, two tests where stack mercury (Hg) data was collected, did not demonstrate any real difference in Hg emissions with PSD.he results from the field tests positively impacts pulverized coal power plants that burn low rank high volatile content coals (such as Powder River Basin coal).hese plants can potentially reduce in-plant load by grinding the coal less (without impacting plant performance on emissions and efficiency) and thereby, increasing their marketability.« less

  14. Method development and validation for measuring the particle size distribution of pentaerythritol tetranitrate (PETN) powders.

    SciTech Connect (OSTI)

    Young, Sharissa Gay

    2005-09-01

    Currently, the critical particle properties of pentaerythritol tetranitrate (PETN) that influence deflagration-to-detonation time in exploding bridge wire detonators (EBW) are not known in sufficient detail to allow development of a predictive failure model. The specific surface area (SSA) of many PETN powders has been measured using both permeametry and gas absorption methods and has been found to have a critical effect on EBW detonator performance. The permeametry measure of SSA is a function of particle shape, packed bed pore geometry, and particle size distribution (PSD). Yet there is a general lack of agreement in PSD measurements between laboratories, raising concerns regarding collaboration and complicating efforts to understand changes in EBW performance related to powder properties. Benchmarking of data between laboratories that routinely perform detailed PSD characterization of powder samples and the determination of the most appropriate method to measure each PETN powder are necessary to discern correlations between performance and powder properties and to collaborate with partnering laboratories. To this end, a comparison was made of the PSD measured by three laboratories using their own standard procedures for light scattering instruments. Three PETN powder samples with different surface areas and particle morphologies were characterized. Differences in bulk PSD data generated by each laboratory were found to result from variations in sonication of the samples during preparation. The effect of this sonication was found to depend on particle morphology of the PETN samples, being deleterious to some PETN samples and advantageous for others in moderation. Discrepancies in the submicron-sized particle characterization data were related to an instrument-specific artifact particular to one laboratory. The type of carrier fluid used by each laboratory to suspend the PETN particles for the light scattering measurement had no consistent effect on the resulting

  15. Evolution of soot size distribution in premixed ethylene/air and ethylene/benzene/air flames: Experimental and modeling study

    SciTech Connect (OSTI)

    Echavarria, Carlos A.; Sarofim, Adel F.; Lighty, JoAnn S.; D'Anna, Andrea

    2011-01-15

    The effect of benzene concentration in the initial fuel on the evolution of soot size distribution in ethylene/air and ethylene/benzene/air flat flames was characterized by experimental measurements and model predictions of size and number concentration within the flames. Experimentally, a scanning mobility particle sizer was used to allow spatially resolved and online measurements of particle concentration and sizes in the nanometer-size range. The model couples a detailed kinetic scheme with a discrete-sectional approach to follow the transition from gas-phase to nascent particles and their coagulation to larger soot particles. The evolution of soot size distribution (experimental and modeled) in pure ethylene and ethylene flames doped with benzene showed a typical nucleation-sized (since particles do not actually nucleate in the classical sense particle inception is often used in place of nucleation) mode close to the burner surface, and a bimodal behavior at greater height above burner (HAB). However, major features were distinguished between the data sets. The growth of nucleation and agglomeration-sized particles was faster for ethylene/benzene/air flames, evidenced by the earlier presence of bimodality in these flames. The most significant changes in size distribution were attributed to an increase in benzene concentration in the initial fuel. However, these changes were more evident for high temperature flames. In agreement with the experimental data, the model also predicted the decrease of nucleation-sized particles in the postflame region for ethylene flames doped with benzene. This behavior was associated with the decrease of soot precursors after the main oxidation zone of the flames. (author)

  16. Science at the interface : grain boundaries in nanocrystalline metals.

    SciTech Connect (OSTI)

    Rodriguez, Mark Andrew; Follstaedt, David Martin; Knapp, James Arthur; Brewer, Luke N.; Holm, Elizabeth Ann; Foiles, Stephen Martin; Hattar, Khalid M.; Clark, Blythe B.; Olmsted, David L.; Medlin, Douglas L.

    2009-09-01

    Interfaces are a critical determinant of the full range of materials properties, especially at the nanoscale. Computational and experimental methods developed a comprehensive understanding of nanograin evolution based on a fundamental understanding of internal interfaces in nanocrystalline nickel. It has recently been shown that nanocrystals with a bi-modal grain-size distribution possess a unique combination of high-strength, ductility and wear-resistance. We performed a combined experimental and theoretical investigation of the structure and motion of internal interfaces in nanograined metal and the resulting grain evolution. The properties of grain boundaries are computed for an unprecedented range of boundaries. The presence of roughening transitions in grain boundaries is explored and related to dramatic changes in boundary mobility. Experimental observations show that abnormal grain growth in nanograined materials is unlike conventional scale material in both the level of defects and the formation of unfavored phases. Molecular dynamics simulations address the origins of some of these phenomena.

  17. 20% (AM1.5) efficiency GaAs solar cells on sub-mm grain-size poly-Ge and its transition to low-cost substrates

    SciTech Connect (OSTI)

    Venkatasubramanian, R.; O`Quinn, B.C.; Siivola, E.; Keyes, B.; Ahrenkiel, R.

    1997-12-31

    Some of the key material and device issues related to the development of GaAs solar cells on poly-Ge substrates, including the dark-current reduction mechanism with an undoped spacer at the p{sup +}-n depletion layer, are discussed. Device-structure optimization studies that have led the authors to achieve an AM1.5 efficiency of {approximately}20% for a 4-cm{sup 2}-area GaAs cell on sub-mm grain-size poly-Ge and an efficiency of {approximately}21% for a 0.25-cm{sup 2}-area cell are presented. This successful demonstration of high-efficiency GaAs cells on sub-mm grain-size poly-Ge substrates have motivated us to consider the development of high-quality GaAs materials on significantly lower-cost substrates such as glass and moly foils. To date, the authors have achieved a best minority-carrier lifetime of 0.41 nsec in an n-GaAs thin-film on moly. The role of Group-VI dopant in the possible passivation of grain-boundaries in poly-GaAs is discussed. Development of PV-quality GaAs material, with minority-carrier lifetime of 1 to 2 nsec, on los-cost moly foils can significantly impact both the terrestrial and the space PV applications.

  18. Method and apparatus for controlled size distribution of gel microspheres formed from aqueous dispersions

    DOE Patents [OSTI]

    Ryon, Allen D.; Haas, Paul A.; Vavruska, John S.

    1984-01-01

    The present invention is directed to a method and apparatus for making a population of dense, closely size-controlled microspheres by sol-gel procedures wherein said microspheres are characterized by a significant percentage of said population being within a predetermined, relatively narrow size range. Microsphere populations thus provided are useful in vibratory-packed processes for nuclear fuels to be irradiated in LWR- and FBR-type nuclear reactors.

  19. Para-hydrogen and helium cluster size distributions in free jet expansions based on Smoluchowski theory with kernel scaling

    SciTech Connect (OSTI)

    Kornilov, Oleg; Toennies, J. Peter

    2015-02-21

    The size distribution of para-H{sub 2} (pH{sub 2}) clusters produced in free jet expansions at a source temperature of T{sub 0} = 29.5 K and pressures of P{sub 0} = 0.91.96 bars is reported and analyzed according to a cluster growth model based on the Smoluchowski theory with kernel scaling. Good overall agreement is found between the measured and predicted, N{sub k} = A?k{sup a} e{sup ?bk}, shape of the distribution. The fit yields values for A and b for values of a derived from simple collision models. The small remaining deviations between measured abundances and theory imply a (pH{sub 2}){sub k} magic number cluster of k = 13 as has been observed previously by Raman spectroscopy. The predicted linear dependence of b{sup ?(a+1)} on source gas pressure was verified and used to determine the value of the basic effective agglomeration reaction rate constant. A comparison of the corresponding effective growth cross sections ?{sub 11} with results from a similar analysis of He cluster size distributions indicates that the latter are much larger by a factor 6-10. An analysis of the three body recombination rates, the geometric sizes and the fact that the He clusters are liquid independent of their size can explain the larger cross sections found for He.

  20. Method and apparatus for controlled size distribution of gel microspheres formed from aqueous dispersions. [Patent application

    DOE Patents [OSTI]

    Ryon, A.D.; Haas, P.A.; Vavruska, J.S.

    1982-01-19

    The present invention is directed to a method and apparatus for making a population of dense, closely size-controlled microspheres by sol-gel procedures wherein said microspheres are characterized by a significant percentage of said population being within a predetermined, relatively narrow size range. This is accomplished by subjecting aqueous dispersions of a sol, within a water-immiscible organic liquid to a turbulent flow. Microsphere populations thus provided are useful in vibratory-packed processes for nuclear fuels to be irradiated in LWR- and FBR-type nuclear reactors.

  1. Environmental Transmission Electron Microscopy Study of the Origins of Anomalous Particle Size Distributions in Supported Metal Catalysts

    SciTech Connect (OSTI)

    Benavidez, Angelica D.; Kovarik, Libor; Genc, Arda; Agrawal, Nitin; Larsson, Elin M.; Hansen, Thomas W.; Karim, Ayman M.; Datye, Abhaya K.

    2012-10-31

    In this Environmental TEM (ETEM) study of supported Pt and Pd model catalysts, individual nanoparticles were tracked during heat treatments at temperatures up to 600C in H2, O2, and vacuum. We found anomalous growth of nanoparticles occurred during the early stages of catalyst sintering wherein some particles started to grow significantly larger than the mean, resulting in a broadening of the particle size distribution. We can rule out sample non-uniformity as a cause for the growth of these large particles, since images were recorded prior to heat treatments. The anomalous growth of these particles may help explain particle size distributions in heterogeneous catalysts which often show particles that are significantly larger than the mean, resulting in a long tail to the right. It has been suggested that particle migration and coalescence could be the likely cause for the broad size distributions. This study shows that anomalous growth of nanoparticles can occur under conditions where Ostwald ripening is the primary sintering mechanism.

  2. Synthesis of supported bimetallic nanoparticles with controlled size and composition distributions for active site elucidation

    SciTech Connect (OSTI)

    Hakim, Sikander H.; Sener, Canan; Alba Rubio, Ana C.; Gostanian, Thomas M.; O'neill, Brandon J; Ribeiro, Fabio H.; Miller, Jeffrey T.; Dumesic, James A

    2015-08-01

    Elucidation of active sites in supported bimetallic catalysts is complicated by the high level of dispersity in the nanoparticle size and composition that is inherent in conventional methods of catalyst preparation. We present a synthesis strategy that leads to highly dispersed, bimetallic nanoparticles with uniform particle size and composition by means of controlled surface reactions. We demonstrate the synthesis of three systems, RhMo, PtMo, and RhRe, consisting of a highly reducible metal with an oxophilic promoter. These catalysts are characterized by FTIR, CO chemisorption, STEM/EDS, TPR, and XAS analysis. The catalytic properties of these bimetallic nanoparticles were probed for the selective CO hydrogenolysis of (hydroxymethyl)tetrahydropyran to produce 1,6 hexanediol. Based on the characterization results and reactivity trends, the active sites in the hydrogenolysis reaction are identified to be small ensembles of the more noble metal (Rh, Pt) adjacent to highly reduced moieties of the more oxophilic metal (Mo, Re).

  3. Importance of Size and Distribution of Ni Nanoparticles for the Hydrodeoxygenation of Microalgae Oil

    SciTech Connect (OSTI)

    Song, Wenji; Zhao, Chen; Lercher, Johannes A.

    2013-07-22

    Improved synthetic approaches for preparing small-sized Ni nanoparticles (d=3 nm) supported on HBEA zeolite have been explored and compared with the traditional impregnation method. The formation of surface nickel silicate/aluminate involved in the two precipitation processes are inferred to lead to the stronger interaction between the metal and the support. The lower Brnsted acid concentrations of these two Ni/HBEA catalysts compared with the parent zeolite caused by the partial exchange of Brnsted acid sites by Ni2+ cations do not influence the hydrodeoxygenation rates, but alter the product selectivity. Higher initial rates and higher stability have been achieved with these optimized catalysts for the hydrodeoxygenation of stearic acid and microalgae oil. Small metal particles facilitate high initial catalytic activity in the fresh sample and size uniformity ensures high catalyst stability.

  4. Mass-velocity and size-velocity distributions of ejecta cloud from shock-loaded tin surface using atomistic simulations

    SciTech Connect (OSTI)

    Durand, O.; Soulard, L.

    2015-04-28

    The mass (volume and areal densities) versus velocity as well as the size versus velocity distributions of a shock-induced cloud of particles are investigated using large scale molecular dynamics simulations. A generic three-dimensional tin crystal with a sinusoidal free surface roughness (single wavelength) is set in contact with vacuum and shock-loaded so that it melts directly on shock. At the reflection of the shock wave onto the perturbations of the free surface, two-dimensional sheets/jets of liquid metal are ejected. The simulations show that the distributions may be described by an analytical model based on the propagation of a fragmentation zone, from the tip of the sheets to the free surface, in which the kinetic energy of the atoms decreases as this zone comes closer to the free surface on late times. As this kinetic energy drives (i) the (self-similar) expansion of the zone once it has broken away from the sheet and (ii) the average size of the particles which result from fragmentation in the zone, the ejected mass and the average size of the particles progressively increase in the cloud as fragmentation occurs closer to the free surface. Though relative to nanometric scales, our model may help in the analysis of experimental profiles.

  5. Determination of plasma frequency, damping constant, and size distribution from the complex dielectric function of noble metal nanoparticles

    SciTech Connect (OSTI)

    Mendoza Herrera, Luis J.; Arboleda, David Muetn; Schinca, Daniel C.; Scaffardi, Luca B.

    2014-12-21

    This paper develops a novel method for simultaneously determining the plasma frequency ?{sub P}?? and the damping constant ?{sub free} in the bulk damped oscillator Drude model, based on experimentally measured real and imaginary parts of the metal refractive index in the IR wavelength range, lifting the usual approximation that restricts frequency values to the UV-deep UV region. Our method was applied to gold, silver, and copper, improving the relative uncertainties in the final values for ?{sub p} (0.5%1.6%) and for ?{sub free} (3%8%), which are smaller than those reported in the literature. These small uncertainties in ?{sub p} and ?{sub free} determination yield a much better fit of the experimental complex dielectric function. For the case of nanoparticles (Nps), a series expansion of the Drude expression (which includes ?{sub p} and ?{sub free} determined using our method) enables size-dependent dielectric function to be written as the sum of three terms: the experimental bulk dielectric function plus two size corrective terms, one for free electron, and the other for bound-electron contributions. Finally, size distribution of nanometric and subnanometric gold Nps in colloidal suspension was determined through fitting its experimental optical extinction spectrum using Mie theory based on the previously determined dielectric function. Results are compared with size histogram obtained from Transmission Electron Microscopy (TEM)

  6. Strain softening mechanism at meso scale during micro-compression in an ultrafine-grained pure copper

    SciTech Connect (OSTI)

    Xu, Jie; Li, Jianwei; Shan, Debin; Guo, Bin

    2015-09-15

    Strain softening behavior has been found at meso scale using micro-compression testing in an ultrafine-grained (UFG) pure copper by comparison with the typical strain hardening in conventional coarse-grained (CG) material. Microstructural observations show that grain size remains nearly the same including the fraction of high-angle grain boundaries during micro-compression in UFG pure copper. The Kernel average misorientation(KAM) distribution measured by electron backscatter diffraction (EBSD), as a statistical method, is applied to qualitatively evaluate dislocation density in the interior of the grains. It is suggested that the deformation mechanisms are dominated by grain boundary sliding and grain rotation accompanied by dislocation slip in UFG pure copper, which demonstrates that the strain softening behavior is primarily caused by dislocation annihilation during micro-compression.

  7. FINE GRAIN NUCLEAR EMULSION

    DOE Patents [OSTI]

    Oliver, A.J.

    1962-04-24

    A method of preparing nuclear track emulsions having mean grain sizes less than 0.1 microns is described. The method comprises adding silver nitrate to potassium bromide at a rate at which there is always a constant, critical excess of silver ions. For minimum size grains, the silver ion concentration is maintained at the critical level of about pAg 2.0 to 5.0 during prectpitation, pAg being defined as the negative logarithm of the silver ion concentration. It is preferred to eliminate the excess silver at the conclusion of the precipitation steps. The emulsion is processed by methods in all other respects generally similar to the methods of the prior art. (AEC)

  8. Laser Transmission Measurements and Plume Particle Size Distributions for Propellant Burn Tests at ATK Elkton in May 2012

    SciTech Connect (OSTI)

    Willitsford, Adam H.; Brown, David M.; Brown, Andrea M.; Airola, Marc B.; Dinello-Fass, Ryan P.; Thomas, Michael E.; Siegrist, Karen M.

    2014-08-28

    Multi-wavelength laser transmittance was measured during a series of open-air propellant burn tests at Alliant Techsystems, Inc., in Elkton, MD, in May 2012. A Mie scattering model was combined with an alumina optical properties model in a simple single-scatter approach to fitting plume transmittance. Wavelength-dependent plume transmission curves were fit to the measured multi-wave- length transmittance data to infer plume particle size distributions at several heights in the plume. Tri-modal lognormal distributions described transmittance data well at all heights. Overall distributions included a mode with nanometer-scale diameter, a second mode at a diameter of ~0.5 µm, and a third, larger particle mode. Larger parti- cles measured 2.5 µm in diameter at 34 cm (14 in.) above the burning propellant surface, but grew to 4 µm in diameter at a height of 57 cm (22 in.), indicative of particle agglomeration in progress as the plume rises. This report presents data, analysis, and results from the study.

  9. Texture enhancement during grain growth of magnesium alloy AZ31B

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

    Bhattacharyya, Jishnu J.; Agnew, S. R.; Muralidharan, G.

    2015-01-03

    In this paper, the microstructure and texture evolution during annealing of rolled Mg alloy AZ31B, at temperatures ranging from 260 to 450°C, is characterized, and a grain growth exponent of n=5, indicating inhibition of grain growth, is observed. Broadening of the normalized grain size distributions, which indicates abnormal grain growth, was observed at all temperatures investigated. It is shown, using a Zener-type analysis for pinning of grain boundaries by particles, that impurity-based particles are responsible for grain growth inhibition and abnormal grain growth. The strong basal texture which develops during rolling of the Mg alloy, resulting in an initial peakmore » intensity in the (0002) pole figure of nine multiples of a random distribution (MRD), increases to ~15 MRD during annealing at 400 and 450°C. Furthermore, a specific texture component {0001}(1120) is observed in the orientation distribution, which increases from 10 to 23 MRD at 400°C. It is hypothesized that the anisotropic grain boundary properties (i.e. low angle boundaries have low energy and mobility) are responsible for the texture strengthening. Additionally, electron backscattered diffraction reveals the recrystallized microstructure to contain a significant number of boundaries with ~30° misorientation about the <0001> direction, and this boundary type persists throughout most annealing treatments explored.« less

  10. Autonomous grain combine control system

    SciTech Connect (OSTI)

    Hoskinson, Reed L.; Kenney, Kevin L.; Lucas, James R.; Prickel, Marvin A.

    2013-06-25

    A system for controlling a grain combine having a rotor/cylinder, a sieve, a fan, a concave, a feeder, a header, an engine, and a control system. The feeder of the grain combine is engaged and the header is lowered. A separator loss target, engine load target, and a sieve loss target are selected. Grain is harvested with the lowered header passing the grain through the engaged feeder. Separator loss, sieve loss, engine load and ground speed of the grain combine are continuously monitored during the harvesting. If the monitored separator loss exceeds the selected separator loss target, the speed of the rotor/cylinder, the concave setting, the engine load target, or a combination thereof is adjusted. If the monitored sieve loss exceeds the selected sieve loss target, the speed of the fan, the size of the sieve openings, or the engine load target is adjusted.

  11. Intercomparison of Large-eddy Simulations of Arctic Mixed-phase Clouds: Importance of Ice Size Distribution Assumptions

    SciTech Connect (OSTI)

    Ovchinnikov, Mikhail; Ackerman, Andrew; Avramov, Alex; Cheng, Anning; Fan, Jiwen; Fridlind, Ann; Ghan, Steven J.; Harrington, Jerry Y.; Hoose, Corinna; Korolev, Alexei; McFarquhar, Greg; Morrison, H.; Paukert, Marco; Savre, Julien; Shipway, Ben; Shupe, Matthew D.; Solomon, Amy; Sulia, Kara

    2014-03-14

    Large-eddy simulations of mixed-phase Arctic clouds by 11 different models are analyzed with the goal of improving understanding and model representation of processes controlling the evolution of these clouds. In a case based on observations from the Indirect and Semi-Direct Aerosol Campaign (ISDAC), it is found that ice number concentration, Ni, exerts significant influence on the cloud structure. Increasing Ni leads to a substantial reduction in liquid water path (LWP) and potential cloud dissipation, in agreement with earlier studies. By comparing simulations with the same microphysics coupled to different dynamical cores as well as the same dynamics coupled to different microphysics schemes, it is found that the ice water path (IWP) is mainly controlled by ice microphysics, while the inter-model differences in LWP are largely driven by physics and numerics of the dynamical cores. In contrast to previous intercomparisons, all models here use the same ice particle properties (i.e., mass-size, mass-fall speed, and mass-capacitance relationships) and a common radiation parameterization. The constrained setup exposes the importance of ice particle size distributions (PSD) in influencing cloud evolution. A clear separation in LWP and IWP predicted by models with bin and bulk microphysical treatments is documented and attributed primarily to the assumed shape of ice PSD used in bulk schemes. Compared to the bin schemes that explicitly predict the PSD, schemes assuming exponential ice PSD underestimate ice growth by vapor deposition and overestimate mass-weighted fall speed leading to an underprediction of IWP by a factor of two in the considered case.

  12. Aerosol concentration and size distribution measured below, in, and above cloud from the DOE G-1 during VOCALS-REx

    SciTech Connect (OSTI)

    Kleinman, L.I.; Daum, P. H.; Lee, Y.-N.; Lewis, E. R.; Sedlacek III, A. J.; Senum, G. I.; Springston, S. R.; Wang, J.; Hubbe, J.; Jayne, J.; Min, Q.; Yum, S. S.; Allen, G.

    2011-06-21

    During the VOCALS Regional Experiment, the DOE G-1 aircraft was used to sample a varying aerosol environment pertinent to properties of stratocumulus clouds over a longitude band extending 800 km west from the Chilean coast at Arica. Trace gas and aerosol measurements are presented as a function of longitude, altitude, and dew point in this study. Spatial distributions are consistent with an upper atmospheric source for O{sub 3} and South American coastal sources for marine boundary layer (MBL) CO and aerosol, most of which is acidic sulfate in agreement with the dominant pollution source being SO{sub 2} from Cu smelters and power plants. Pollutant layers in the free troposphere (FT) can be a result of emissions to the north in Peru or long range transport from the west. At a given altitude in the FT (up to 3 km), dew point varies by 40 C with dry air descending from the upper atmospheric and moist air having a BL contribution. Ascent of BL air to a cold high altitude results in the condensation and precipitation removal of all but a few percent of BL water along with aerosol that served as CCN. Thus, aerosol volume decreases with dew point in the FT. Aerosol size spectra have a bimodal structure in the MBL and an intermediate diameter unimodal distribution in the FT. Comparing cloud droplet number concentration (CDNC) and pre-cloud aerosol (Dp > 100 nm) gives a linear relation up to a number concentration of {approx}150 cm{sup -3}, followed by a less than proportional increase in CDNC at higher aerosol number concentration. A number balance between below cloud aerosol and cloud droplets indicates that {approx}25% of aerosol in the PCASP size range are interstitial (not activated). One hundred and two constant altitude cloud transects were identified and used to determine properties of interstitial aerosol. One transect is examined in detail as a case study. Approximately 25 to 50% of aerosol with D{sub p} > 110 nm were not activated, the difference between the two

  13. The Occurrence of Particle Size Distribution Bimodality in Midlatitude Cirrus as Inferred from Ground-Based Remote Sensing Data

    SciTech Connect (OSTI)

    Zhao, Yang; Mace, Gerald G.; Comstock, Jennifer M.

    2011-06-01

    To better understand the role of small particles in the microphysical processes and the radiative properties of cirrus, the reliability of historical in-situ data must be understood. Recent studies call into question the validity of that data because of shattering of large crystals on probe and aircraft surfaces thereby artificially amplifying the concentration of crystals smaller than approximately 50 ?m. We contend that the general character of the in-situ measurements must be consistent, in a broad sense, with statistics derived from long-term remote sensing data. To examine this consistency, an algorithm using Doppler radar moments and Raman lidar extinction is developed to retrieve a bimodal particle size distribution and its uncertainty. Using case studies and statistics compiled over one year we show that the existence of high concentrations (> 1 cm-3 ) of small (sub 50 ?m) particles in cirrus are not consistent with any reasonable interpretation of the remote sensing data. We conclude that the high concentrations of small particles found in many aircraft data sets are therefore likely an artifact of the in situ measurement process.

  14. Charging of dust grains in a nonequilibrium plasma of a stratified glow discharge

    SciTech Connect (OSTI)

    Sukhinin, G. I.; Fedoseev, A. V.

    2007-12-15

    A theoretical model is presented that describes the charging of dust grains in the positive plasma column of a stratified glow dc discharge in argon. A one-dimensional self-consistent model is used to obtain axial profiles of the electric field, as well as the electron energy distribution function along the axis of the discharge tube. Radial profiles of the electric field are determined in the ambipolar diffusion approximation. It is assumed that, in the radial direction, the electron distribution function depends only on the total electron energy. Two-dimensional distributions of the discharge plasma parameters are calculated and used to determine the potential and charge of a test dust grain at a certain point within the discharge and the electrostatic forces acting on it. It is shown that the grain charge distribution depends strongly on the nonequilibrium electron distribution function and on the nonuniform distribution of the electric field in a stratified glow discharge. A discussion is presented on the suspension of dust grains, the separation of grains by size in the discharge striations, and a possible mechanism for the onset of vortex dust motion at the edge of a dust cloud.

  15. Aerosol concentration and size distribution measured below, in, and above cloud from the DOE G-1 during VOCALS-REx

    SciTech Connect (OSTI)

    Kleinman L. I.; Daum, P. H.; Lee, Y.-N.; Lewis, E. R.; Sedlacek III, A. J.; Senum, G. I.; Springston, S. R.; Wang, J.; Hubbe, J.; Jayne, J.; Min, Q.; Yum, S. S.; Allen, G.

    2012-01-04

    During the VOCALS Regional Experiment, the DOE G-1 aircraft was used to sample a varying aerosol environment pertinent to properties of stratocumulus clouds over a longitude band extending 800 km west from the Chilean coast at Arica. Trace gas and aerosol measurements are presented as a function of longitude, altitude, and dew point in this study. Spatial distributions are consistent with an upper atmospheric source for O{sub 3} and South American coastal sources for marine boundary layer (MBL) CO and aerosol, most of which is acidic sulfate. Pollutant layers in the free troposphere (FT) can be a result of emissions to the north in Peru or long range transport from the west. At a given altitude in the FT (up to 3 km), dew point varies by 40 C with dry air descending from the upper atmospheric and moist air having a boundary layer (BL) contribution. Ascent of BL air to a cold high altitude results in the condensation and precipitation removal of all but a few percent of BL water along with aerosol that served as CCN. Thus, aerosol volume decreases with dew point in the FT. Aerosol size spectra have a bimodal structure in the MBL and an intermediate diameter unimodal distribution in the FT. Comparing cloud droplet number concentration (CDNC) and pre-cloud aerosol (D{sub p} > 100 nm) gives a linear relation up to a number concentration of {approx}150 cm{sup -3}, followed by a less than proportional increase in CDNC at higher aerosol number concentration. A number balance between below cloud aerosol and cloud droplets indicates that {approx}25 % of aerosol with D{sub p} > 100 nm are interstitial (not activated). A direct comparison of pre-cloud and in-cloud aerosol yields a higher estimate. Artifacts in the measurement of interstitial aerosol due to droplet shatter and evaporation are discussed. Within each of 102 constant altitude cloud transects, CDNC and interstitial aerosol were anti-correlated. An examination of one cloud as a case study shows that the

  16. Evaluation of moist processes during intense precipitation in km-scale NWP models using remote sensing and in-situ data: Impact of microphysics size distribution assumptions

    SciTech Connect (OSTI)

    VanWeverberg, K.; vanLipzig, N. P. M.; Delobbe, L.

    2011-02-01

    This study investigates the sensitivity of moist processes and surface precipitation during three extreme precipitation events over Belgium to the representation of rain, snow and hail size distributions in a bulk one-moment microphysics parameterisation scheme. Sensitivities included the use of empirically derived relations to calculate the slope parameter and diagnose the intercept parameter of the exponential snow and rain size distributions and sensitivities to the treatment of hail/graupel. A detailed evaluation of the experiments against various high temporal resolution and spatially distributed observational data was performed to understand how moist processes responded to the implemented size distribution modifications. Net vapor consumption by microphysical processes was found to be unaffected by snow or rain size distribution modifications, while it was reduced replacing formulations for hail by those typical for graupel, mainly due to intense sublimation of graupel. Cloud optical thickness was overestimated in all experiments and all cases, likely due to overestimated snow amounts. The overestimation slightly deteriorated by modifying the rain and snow size distributions due to increased snow depositional growth, while it was reduced by including graupel. The latter was mainly due to enhanced cloud water collection by graupel and reduced snow depositional growth. Radar reflectivity and cloud optical thickness could only be realistically represented by inclusion of graupel during a stratiform case, while hail was found indispensable to simulate the vertical reflectivity profile and the surface precipitation structure. Precipitation amount was not much altered by any of the modifications made and the general overestimation was only decreased slightly during a supercell convective case.

  17. Alpha spectrometric characterization of process-related particle size distributions from active particle sampling at the Los Alamos National Laboratory uranium foundry

    SciTech Connect (OSTI)

    Plionis, Alexander A; Peterson, Dominic S; Tandon, Lav; Lamont, Stephen P

    2009-01-01

    Uranium particles within the respirable size range pose a significant hazard to the health and safety of workers. Significant differences in the deposition and incorporation patterns of aerosols within the respirable range can be identified and integrated into sophisticated health physics models. Data characterizing the uranium particle size distribution resulting from specific foundry-related processes are needed. Using personal air sampling cascade impactors, particles collected from several foundry processes were sorted by activity median aerodynamic diameter onto various Marple substrates. After an initial gravimetric assessment of each impactor stage, the substrates were analyzed by alpha spectrometry to determine the uranium content of each stage. Alpha spectrometry provides rapid nondestructive isotopic data that can distinguish process uranium from natural sources and the degree of uranium contribution to the total accumulated particle load. In addition, the particle size bins utilized by the impactors provide adequate resolution to determine if a process particle size distribution is: lognormal, bimodal, or trimodal. Data on process uranium particle size values and distributions facilitate the development of more sophisticated and accurate models for internal dosimetry, resulting in an improved understanding of foundry worker health and safety.

  18. Intrinsic fluctuations of dust grain charge in multi-component plasmas

    SciTech Connect (OSTI)

    Shotorban, B.

    2014-03-15

    A master equation is formulated to model the states of the grain charge in a general multi-component plasma, where there are electrons and various kinds of positive or negative ions that are singly or multiply charged. A Fokker-Planck equation is developed from the master equation through the system-size expansion method. The Fokker-Planck equation has a Gaussian solution with a mean and variance governed by two initial-value differential equations involving the rates of the attachment of ions and electrons to the dust grain. Also, a Langevin equation and a discrete stochastic method are developed to model the time variation of the grain charge. Grain charging in a plasma containing electrons, protons, and alpha particles with Maxwellian distributions is considered as an example problem. The Gaussian solution is in very good agreement with the master equation solution numerically obtained for this problem.

  19. Grain boundary and triple junction diffusion in nanocrystalline copper

    SciTech Connect (OSTI)

    Wegner, M. Leuthold, J.; Peterlechner, M.; Divinski, S. V.; Song, X.; Wilde, G.

    2014-09-07

    Grain boundary and triple junction diffusion in nanocrystalline Cu samples with grain sizes, ?d?, of ?35 and ?44?nm produced by spark plasma sintering were investigated by the radiotracer method using the {sup 63}Ni isotope. The measured diffusivities, D{sub eff}, are comparable with those determined previously for Ni grain boundary diffusion in well-annealed, high purity, coarse grained, polycrystalline copper, substantiating the absence of a grain size effect on the kinetic properties of grain boundaries in a nanocrystalline material at grain sizes d???35?nm. Simultaneously, the analysis predicts that if triple junction diffusion of Ni in Cu is enhanced with respect to the corresponding grain boundary diffusion rate, it is still less than 500?D{sub gb} within the temperature interval from 420?K to 470?K.

  20. High capacitance of coarse-grained carbide derived carbon electrodes

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

    Dyatkin, Boris; Gogotsi, Oleksiy; Malinovskiy, Bohdan; Zozulya, Yuliya; Simon, Patrice; Gogotsi, Yury

    2016-01-01

    Here, we report exceptional electrochemical properties of supercapacitor electrodes composed of large, granular carbide-derived carbon (CDC) particles. We synthesized 70–250 μm sized particles with high surface area and a narrow pore size distribution, using a titanium carbide (TiC) precursor. Electrochemical cycling of these coarse-grained powders defied conventional wisdom that a small particle size is strictly required for supercapacitor electrodes and allowed high charge storage densities, rapid transport, and good rate handling ability. Moreover, the material showcased capacitance above 100 F g-1 at sweep rates as high as 250 mV s-1 in organic electrolyte. 250–1000 micron thick dense CDC films withmore » up to 80 mg cm-2 loading showed superior areal capacitances. The material significantly outperformed its activated carbon counterpart in organic electrolytes and ionic liquids. Furthermore, large internal/external surface ratio of coarse-grained carbons allowed the resulting electrodes to maintain high electrochemical stability up to 3.1 V in ionic liquid electrolyte. In addition to presenting novel insights into the electrosorption process, these coarse-grained carbons offer a pathway to low-cost, high-performance implementation of supercapacitors in automotive and grid-storage applications.« less

  1. High capacitance of coarse-grained carbide derived carbon electrodes

    SciTech Connect (OSTI)

    Dyatkin, Boris; Gogotsi, Oleksiy; Malinovskiy, Bohdan; Zozulya, Yuliya; Simon, Patrice; Gogotsi, Yury

    2016-01-01

    Here, we report exceptional electrochemical properties of supercapacitor electrodes composed of large, granular carbide-derived carbon (CDC) particles. We synthesized 70–250 μm sized particles with high surface area and a narrow pore size distribution, using a titanium carbide (TiC) precursor. Electrochemical cycling of these coarse-grained powders defied conventional wisdom that a small particle size is strictly required for supercapacitor electrodes and allowed high charge storage densities, rapid transport, and good rate handling ability. Moreover, the material showcased capacitance above 100 F g-1 at sweep rates as high as 250 mV s-1 in organic electrolyte. 250–1000 micron thick dense CDC films with up to 80 mg cm-2 loading showed superior areal capacitances. The material significantly outperformed its activated carbon counterpart in organic electrolytes and ionic liquids. Furthermore, large internal/external surface ratio of coarse-grained carbons allowed the resulting electrodes to maintain high electrochemical stability up to 3.1 V in ionic liquid electrolyte. In addition to presenting novel insights into the electrosorption process, these coarse-grained carbons offer a pathway to low-cost, high-performance implementation of supercapacitors in automotive and grid-storage applications.

  2. Property Improvement in CZT via Modeling and Processing Innovations . Te-particles in vertical gradient freeze CZT: Size and Spatial Distributions and Constitutional Supercooling

    SciTech Connect (OSTI)

    Henager, Charles H.; Alvine, Kyle J.; Bliss, Mary; Riley, Brian J.; Stave, Jean A.

    2014-10-01

    A section of a vertical gradient freeze CZT boule approximately 2100-mm3 with a planar area of 300-mm2 was prepared and examined using transmitted IR microscopy at various magnifications to determine the three-dimensional spatial and size distributions of Te-particles over large longitudinal and radial length scales. The boule section was approximately 50-mm wide by 60-mm in length by 7-mm thick and was doubly polished for TIR work. Te-particles were imaged through the thickness using extended focal imaging to locate the particles in thickness planes spaced 15-µm apart and then in plane of the image using xy-coordinates of the particle center of mass so that a true three dimensional particle map was assembled for a 1-mm by 45-mm longitudinal strip and for a 1-mm by 50-mm radial strip. Te-particle density distributions were determined as a function of longitudinal and radial positions in these strips, and treating the particles as vertices of a network created a 3D image of the particle spatial distribution. Te-particles exhibited a multi-modal log-normal size density distribution that indicated a slight preference for increasing size with longitudinal growth time, while showing a pronounced cellular network structure throughout the boule that can be correlated to dislocation network sizes in CZT. Higher magnification images revealed a typical Rayleigh-instability pearl string morphology with large and small satellite droplets. This study includes solidification experiments in small crucibles of 30:70 mixtures of Cd:Te to reduce the melting point below 1273 K (1000°C). These solidification experiments were performed over a wide range of cooling rates and clearly demonstrated a growth instability with Te-particle capture that is suggested to be responsible for one of the peaks in the size distribution using size discrimination visualization. The results are discussed with regard to a manifold Te-particle genesis history as 1) Te

  3. The role of precipitation size distributions in km-scale NWP simulations of intense precipitation: Evaluation of cloud properties and surface precipitation

    SciTech Connect (OSTI)

    VanWeverberg K.; Vogelmann A.; vanLipzig, N. P. M.; Delobbec, L.

    2012-04-01

    We investigate the sensitivity of simulated cloud properties and surface precipitation to assumptions regarding the size distributions of the precipitating hydrometeors in a one-moment bulk microphysics scheme. Three sensitivity experiments were applied to two composites of 15 convective and 15 frontal stratiform intense precipitation events observed in a coastal midlatitude region (Belgium), which were evaluated against satellite-retrieved cloud properties and radar-rain-gauge derived surface precipitation. It is found that the cloud optical thickness distribution was well captured by all experiments, although a significant underestimation of cloudiness occurred in the convective composite. The cloud-top-pressure distribution was improved most by more realistic snow size distributions (including a temperature-dependent intercept parameter and non-spherical snow for the calculation of the slope parameter), due to increased snow depositional growth at high altitudes. Surface precipitation was far less sensitive to whether graupel or hail was chosen as the rimed ice species, as compared to previous idealized experiments. This smaller difference in sensitivity could be explained by the stronger updraught velocities and higher freezing levels in the idealized experiments compared to typical coastal midlatitude environmental conditions.

  4. Stabilizing Nanocrystalline Grains in Ceramic-Oxides

    SciTech Connect (OSTI)

    Aidhy, Dilpuneet S; Zhang, Yanwen; Weber, William J

    2013-01-01

    Nanocrystalline ceramic-oxides are prone to grain growth rendering their highly attractive properties practically unusable. Using atomistic simulations ofon ceria as a model material system, we elucidate a framework to design dopant-pinned grain boundaries that prevent this grain growth. While in metallic systems it has been shown that a large mismatch between host and dopant atomic size prevents grain growth, in ceramic-oxides we find that this concept is not applicable. Instead, we find that dopant-oxygen vacancy interaction, i.e., dopant migration energy in the presence of oxygen vacancy, and dopant-oxygen vacancy binding energy are the controlling factors in grain growth. Our prediction agrees with and explains previous experimental observations.

  5. Distribution:

    Office of Legacy Management (LM)

    JAN26 19% Distribution: OR00 Attn: h.H.M.Roth DFMusser ITMM MMMann INS JCRyan FIw(2) Hsixele SRGustavson, Document rocm Formal file i+a@mmm bav@ ~@esiaw*cp Suppl. file 'Br & Div rf's s/health (lic.only) UNITED STATES ATOMIC ENERGY COMMISSION SPECIAL NUCLEAB MATERIAL LICENSE pursuant to the Atomic Energy Act of 1954 and Title 10, Code of Federal Regulations, Chapter 1, P&t 70, "Special Nuclear Material Reg)llatiqm," a license is hereby issued a$hortztng the licensee to rekeive

  6. Investigation of thermochemical biorefinery sizing and environmental sustainability impacts for conventional supply system and distributed preprocessing supply system designs

    SciTech Connect (OSTI)

    Muth, jr., David J.; Langholtz, Matthew H.; Tan, Eric; Jacobson, Jacob; Schwab, Amy; Wu, May; Argo, Andrew; Brandt, Craig C.; Cafferty, Kara; Chiu, Yi-Wen; Dutta, Abhijit; Eaton, Laurence M.; Searcy, Erin

    2014-03-31

    The 2011 US Billion-Ton Update estimates that by 2030 there will be enough agricultural and forest resources to sustainably provide at least one billion dry tons of biomass annually, enough to displace approximately 30% of the country's current petroleum consumption. A portion of these resources are inaccessible at current cost targets with conventional feedstock supply systems because of their remoteness or low yields. Reliable analyses and projections of US biofuels production depend on assumptions about the supply system and biorefinery capacity, which, in turn, depend upon economic value, feedstock logistics, and sustainability. A cross-functional team has examined combinations of advances in feedstock supply systems and biorefinery capacities with rigorous design information, improved crop yield and agronomic practices, and improved estimates of sustainable biomass availability. A previous report on biochemical refinery capacity noted that under advanced feedstock logistic supply systems that include depots and pre-processing operations there are cost advantages that support larger biorefineries up to 10 000 DMT/day facilities compared to the smaller 2000 DMT/day facilities. This report focuses on analyzing conventional versus advanced depot biomass supply systems for a thermochemical conversion and refinery sizing based on woody biomass. The results of this analysis demonstrate that the economies of scale enabled by advanced logistics offsets much of the added logistics costs from additional depot processing and transportation, resulting in a small overall increase to the minimum ethanol selling price compared to the conventional logistic supply system. While the overall costs do increase slightly for the advanced logistic supply systems, the ability to mitigate moisture and ash in the system will improve the storage and conversion processes. In addition, being able to draw on feedstocks from further distances will decrease the risk of biomass supply to the

  7. Effect of Grain Boundaries on Krypton Segregation Behavior in Irradiated Uranium Dioxide

    SciTech Connect (OSTI)

    Valderrama, Billy; He, Lingfeng; Henderson, Hunter B.; Pakarinen, Janne; Jaques, Brian; Gan, Jian; Butt, Darryl P.; Allen, Todd R.; Manuel, Michele V.

    2014-11-01

    Fission products, such as krypton (Kr), are known to be insoluble within UO2, segregating towards grain boundaries, eventually leading to a lowering of the thermal conductivity and fuel swelling. Recent computational studies have identified that differences in grain boundary structure have a significant effect on the segregation behavior of fission products. However, experimental work supporting these simulations is lacking. Atom probe tomography was used to measure the Kr distribution across grain boundaries in UO2. Polycrystalline depleted-UO2 samples was irradiated with 0.7 and 1.8 MeV Kr-ions and annealed to 1000C, 1300C, and 1600C for 1 hour to produce a Kr-bubble dominated microstructure. The results of this work indicate a strong dependence of Kr concentration as a function of grain boundary structure. Temperature also influences grain boundary chemistry with greater Kr concentration evident at higher temperatures, resulting in a reduced Kr concentration in the bulk. While Kr migration is active at elevated temperatures, no changes in grain size or texture were observed in the irradiated UO2 samples.

  8. Modeling of stress distributions on the microstructural level in Alloy 600

    SciTech Connect (OSTI)

    Kozaczek, K.J.; Petrovic, B.G.; Ruud, C.O.; Mcllree, A.R.

    1995-04-01

    Stress distribution in a random polycrystalline material (Alloy 600) was studied using a topologically correct microstructural model. Distributions of von Mises and hydrostatic stresses at the grain vertices, which could be important in intergranular stress corrosion cracking, were analyzed as functions of microstructure, grain orientations and loading conditions. Grain size, shape, and orientation had a more pronounced effect on stress distribution than loading conditions. At grain vertices the stress concentration factor was higher for hydrostatic stress (1.7) than for von Mises stress (1.5). The stress/strain distribution in the volume (grain interiors) is a normal distribution and does not depend on the location of the studied material volume i.e., surface vs/bulk. The analysis of stress distribution in the volume showed the von Mises stress concentration of 1.75 and stress concentration of 2.2 for the hydrostatic pressure. The observed stress concentration is high enough to cause localized plastic microdeformation, even when the polycrystalline aggregate is in the macroscopic elastic regime. Modeling of stresses and strains in polycrystalline materials can identify the microstructures (grain size distributions, texture) intrinsically susceptible to stress/strain concentrations and justify the correctness of applied stress state during the stress corrosion cracking tests. Also, it supplies the information necessary to formulate the local failure criteria and interpret of nondestructive stress measurements.

  9. Net Metering Policy Development and Distributed Solar Generation in Minnesota: Overview of Trends in Nationwide Policy Development and Implications of Increasing the Eligible System Size Cap

    SciTech Connect (OSTI)

    Doris, E.; Busche, S.; Hockett, S.

    2009-12-01

    The goal of the Minnesota net metering policy is to give the maximum possible encouragement to distributed generation assets, especially solar electric systems (MN 2008). However, according to a published set of best practices (NNEC 2008) that prioritize the maximum development of solar markets within states, the Minnesota policy does not incorporate many of the important best practices that may help other states transform their solar energy markets and increase the amount of grid-connected distributed solar generation assets. Reasons cited include the low system size limit of 40kW (the best practices document recommends a 2 MW limit) and a lack of language protecting generators from additional utility fees. This study was conducted to compare Minnesota's policies to national best practices. It provides an overview of the current Minnesota policy in the context of these best practices and other jurisdictions' net metering policies, as well as a qualitative assessment of the impacts of raising the system size cap within the policy based on the experiences of other states.

  10. On the interaction of solutes with grain boundaries

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

    Dingreville, Remi Philippe Michel; Berbenni, Stephane

    2015-11-01

    Solute segregation to grain boundaries is considered by modeling solute atoms as misfitting inclusions within a disclination structural unit model describing the grain boundary structure and its intrinsic stress field. The solute distribution around grain boundaries is described through Fermi–Dirac statistics of site occupancy. The susceptibility of hydrogen segregation to symmetric tilt grain boundaries is discussed in terms of the misorientation angle, the defect type characteristics at the grain boundary, temperature, and the prescribed bulk hydrogen fraction of occupied sites. Through this formalism, it is found that hydrogen trapping on grain boundaries clearly correlates with the grain boundary structure (i.e.more » type of structural unit composing the grain boundary), and the associated grain boundary misorientation. Specifically, for symmetric tilt grain boundaries about the [001] axis, grain boundaries composed of both B and C structural units show a lower segregation susceptibility than other grain boundaries. A direct correlation between the segregation susceptibility and the intrinsic net defect density is provided through the Frank–Bilby formalism. Moreover, the present formulation could prove to be a simple and useful model to identify classes of grain boundaries relevant to grain boundary engineering.« less

  11. On the interaction of solutes with grain boundaries

    SciTech Connect (OSTI)

    Dingreville, Remi Philippe Michel; Berbenni, Stephane

    2015-11-01

    Solute segregation to grain boundaries is considered by modeling solute atoms as misfitting inclusions within a disclination structural unit model describing the grain boundary structure and its intrinsic stress field. The solute distribution around grain boundaries is described through Fermi–Dirac statistics of site occupancy. The susceptibility of hydrogen segregation to symmetric tilt grain boundaries is discussed in terms of the misorientation angle, the defect type characteristics at the grain boundary, temperature, and the prescribed bulk hydrogen fraction of occupied sites. Through this formalism, it is found that hydrogen trapping on grain boundaries clearly correlates with the grain boundary structure (i.e. type of structural unit composing the grain boundary), and the associated grain boundary misorientation. Specifically, for symmetric tilt grain boundaries about the [001] axis, grain boundaries composed of both B and C structural units show a lower segregation susceptibility than other grain boundaries. A direct correlation between the segregation susceptibility and the intrinsic net defect density is provided through the Frank–Bilby formalism. Moreover, the present formulation could prove to be a simple and useful model to identify classes of grain boundaries relevant to grain boundary engineering.

  12. Optimization of strength and ductility in nanotwinned ultrafine grained Ag: twin density and grain orientations

    SciTech Connect (OSTI)

    Ott, R. T.; Geng, J.; Besser, M. F.; Kramer, M. J.; Wang, Y. M.; Park, E. S.; LeSar, R.; King, A. H.

    2015-06-27

    Nanotwinned ultrafine grained Ag thick films with different twin densities and orientations have been synthesized by magnetron sputtering with a wide-range of deposition rates. The twin boundary (TB) spacings and orientations as well as the grain size for the different deposition conditions have been characterized by both synchrotron X-ray scattering and transmission electron microscopy (TEM). Structural characterization combined with uniaxial tensile tests of the free-standing films reveals a large increase in the yield strength for films deposited at high deposition rates without any accompanying change in the TB spacing – a behavior that is in contrast with what has been reported in the literature. We find that films deposited at lower deposition rates exhibit more randomly oriented grains with a lower overall twin density (averaged over all the grains) than the more heavily twinned grains with strong <111> fiber texture in the films deposited at higher deposition rates. The TB spacing in the twinned grains, however, does not show any significant dependence on the deposition rate. The dependence of the strength and ductility on the twin density and orientations can be described by two different soft deformation modes: 1) untwinned grains and 2) nanowinned grains that are not oriented with <111> along the growth direction. The untwinned grains provide relatively low resistance to slip, and thus decreased strength, while the nanotwinned grains that are not oriented with <111> along the growth direction are softer than nanotwinned grains that are oriented with <111> along the growth direction. We reveal that an ultrafine-grained (150-200 nm) structure consisting of a mixture of nanotwinned (~ 8-12 nm spacing) and untwined grains yields the best combination of high strength and uniform tensile ductility.

  13. Optimization of strength and ductility in nanotwinned ultrafine grained Ag: twin density and grain orientations

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

    Ott, R. T.; Geng, J.; Besser, M. F.; Kramer, M. J.; Wang, Y. M.; Park, E. S.; LeSar, R.; King, A. H.

    2015-06-27

    Nanotwinned ultrafine grained Ag thick films with different twin densities and orientations have been synthesized by magnetron sputtering with a wide-range of deposition rates. The twin boundary (TB) spacings and orientations as well as the grain size for the different deposition conditions have been characterized by both synchrotron X-ray scattering and transmission electron microscopy (TEM). Structural characterization combined with uniaxial tensile tests of the free-standing films reveals a large increase in the yield strength for films deposited at high deposition rates without any accompanying change in the TB spacing – a behavior that is in contrast with what has beenmore » reported in the literature. We find that films deposited at lower deposition rates exhibit more randomly oriented grains with a lower overall twin density (averaged over all the grains) than the more heavily twinned grains with strong <111> fiber texture in the films deposited at higher deposition rates. The TB spacing in the twinned grains, however, does not show any significant dependence on the deposition rate. The dependence of the strength and ductility on the twin density and orientations can be described by two different soft deformation modes: 1) untwinned grains and 2) nanowinned grains that are not oriented with <111> along the growth direction. The untwinned grains provide relatively low resistance to slip, and thus decreased strength, while the nanotwinned grains that are not oriented with <111> along the growth direction are softer than nanotwinned grains that are oriented with <111> along the growth direction. We reveal that an ultrafine-grained (150-200 nm) structure consisting of a mixture of nanotwinned (~ 8-12 nm spacing) and untwined grains yields the best combination of high strength and uniform tensile ductility.« less

  14. The effect of turbulence on the stability of liquid jets and the resulting droplet size distributions. Third quarterly technical report, July 1, 1993--September 30, 1993

    SciTech Connect (OSTI)

    Mansour, A.; Chigier, N.

    1993-12-01

    Laminar and turbulent columns of liquids issuing from capillary tubes were studied in order to determine the effects of turbulence on the stability of liquid jets and to establish the influence of liquid turbulence on droplet size distributions after breakup. Two capillary tubes were chosen with diameters D{sub 1}=3.0mm and D{sub 2}=1.2mm; jet Reynolds numbers were 1000--30000, and 400--7200. For water injection into stagnant air, stability curve is bounded by a laminar portion, where a jet radius and {delta}{sub o} initial disturbance amplitude, and a fully developed turbulent portion characterized by high initial disturbance amplitude (ln(a/{delta}{sub o,T}) {approximately} 4.85). In the transition region, ln(a/{delta}{sub o}) is not single valued; it decreases with increasing Reynolds number. In absence of aerodynamic effects, turbulent jets are as stable as laminar jets. For this breakup mode turbulence propagates initial disturbances with amplitudes orders of magnitude larger than laminar jets ({delta}{sub o,T}=28{times}10{sup 6} {delta}{sub o,L}). Growth rates of initial disturbances are same for both laminar and turbulent columns with theoretical Weber values. Droplet size distribution is bi-modal; the number ratio of large (> D/2), to small (< D/2) droplets is 3 and independent of Reynolds number. For laminar flow optimum wavelength ({lambda}{sub opt}) corresponding to fastest growing disturbance is equal to 4.45D, exactly the theoretical Weber value. For turbulent flow conditions, the turbulent column segments. Typically, segments with lengths of one to several wavelengths, detach from the liquid jet. The long ligaments contract under the action of surface tension, resulting in droplet sizes larger than predicted by Rayleigh and Weber. For turbulent flow conditions, {lambda}{sub opt} = 9.2D, about 2 times the optimum Weber wavelength.

  15. Grain Refinement of Permanent Mold Cast Copper Base Alloys

    SciTech Connect (OSTI)

    M.Sadayappan; J.P.Thomson; M.Elboujdaini; G.Ping Gu; M. Sahoo

    2005-04-01

    Grain refinement is a well established process for many cast and wrought alloys. The mechanical properties of various alloys could be enhanced by reducing the grain size. Refinement is also known to improve casting characteristics such as fluidity and hot tearing. Grain refinement of copper-base alloys is not widely used, especially in sand casting process. However, in permanent mold casting of copper alloys it is now common to use grain refinement to counteract the problem of severe hot tearing which also improves the pressure tightness of plumbing components. The mechanism of grain refinement in copper-base alloys is not well understood. The issues to be studied include the effect of minor alloy additions on the microstructure, their interaction with the grain refiner, effect of cooling rate, and loss of grain refinement (fading). In this investigation, efforts were made to explore and understand grain refinement of copper alloys, especially in permanent mold casting conditions.

  16. ULTRAVIOLET RADIATION INSIDE INTERSTELLAR GRAIN AGGREGATES. III. FLUFFY GRAINS

    SciTech Connect (OSTI)

    Cacciola, Adriano; Saija, Rosalba; Borghese, Ferdinando; Denti, Paolo; Cecchi-Pestellini, Cesare; Iati, Maria Antonia

    2009-08-20

    We study the problem of light depolarization within fluffy interstellar dust grains, in which coagulation generates interstitial cavities partly filled with icy condensed gas. A significant amount of elliptical polarized ultraviolet radiation may be generated in situ by geometry-induced depolarization within the cavities. The behavior of the depolarization is studied both by changing the orientation of the aggregates and by changing chemical composition and size of the subunits forming the aggregate. We found that a considerable amount of depolarization occurs within the ice mantles of the subunits, provided their thickness is not too large. We discuss the implications of these results for chiral selection in space.

  17. PROGRESS ON LARGE GRAIN AND SINGLE GRAIN NIOBIUM: INGOTS AND SHEET AND REVIEW OF PROGRESS ON LARGE GRAIN AND SINGLE GRAIN NIOBIUM CAVITIES

    SciTech Connect (OSTI)

    Peter Kneisel

    2008-02-12

    Large grain and single crystal niobium has been proposed several years ago as an alternative material to poly-crystalline niobium for superconducting cavities, exhibiting potential advantages such as ¿stream-lined¿ procedures, reduced costs and better reproducibility in performance. Several major laboratories have investigated the use of large grain and single crystal material in the past years and the niobium producing industry has responded in providing ingot material with enlarged grain sizes. Besides a large number of single cell and multi-cell cavities from large grain niobium, several single crystal cavities have been fabricated and tested with good performances. This contribution will review the progress since the SRF workshop in 2005 in material processing and handling and in cavity performances.

  18. Grain size dependent phase stabilities and presence of a monoclinic (Pm) phase in the morphotropic phase boundary region of (1?x)Bi(Mg{sub 1/2}Ti{sub 1/2})O{sub 3}-xPbTiO{sub 3} piezoceramics

    SciTech Connect (OSTI)

    Upadhyay, Ashutosh; Singh, Akhilesh Kumar E-mail: aksingh.mst@itbhu.ac.in

    2015-04-14

    Results of the room temperature structural studies on (1?x)Bi(Mg{sub 1/2}Ti{sub 1/2})O{sub 3}-xPbTiO{sub 3} ceramics using Rietveld analysis of the powder x-ray diffraction data in the composition range 0.28???x???0.45 are presented. The morphotropic phase boundary region exhibits coexistence of monoclinic (space group Pm) and tetragonal (space group P4?mm) phases in the composition range 0.33???x???0.40. The structure is nearly single phase monoclinic (space group Pm) in the composition range 0.28???x???0.32. The structure for the compositions with x???0.45 is found to be predominantly tetragonal with space group P4?mm. Rietveld refinement of the structure rules out the coexistence of rhombohedral and tetragonal phases in the morphotropic phase boundary region reported by earlier authors. The Rietveld structure analysis for the sample x?=?.35 calcined at various temperatures reveals that phase fraction of the coexisting phases in the morphotropic phase boundary region varies with grain size. The structural parameters of the two coexisting phases also change slightly with changing grain size.

  19. Pre-accretional sorting of grains in the outer solar nebula

    SciTech Connect (OSTI)

    Wozniakiewicz, P. J.; Bradley, J. P.; Ishii, H. A.; Price, M. C.; Brownlee, D. E.

    2013-12-20

    Despite their micrometer-scale dimensions and nanogram masses, chondritic porous interplanetary dust particles (CP IDPs) are an important class of extraterrestrial material since their properties are consistent with a cometary origin and they show no evidence of significant post-accretional parent body alteration. Consequently, they can provide information about grain accretion in the comet-forming region of the outer solar nebula. We have previously reported our comparative study of the sizes and size distributions of crystalline silicate and sulfide grains in CP IDPs, in which we found these components exhibit a size-density relationship consistent with having been sorted together prior to accretion. Here we extend our data set and include GEMS (glass with embedded metal and sulfide), the most abundant amorphous silicate phase observed in CP IDPs. We find that while the silicate and sulfide sorting trend previously observed is maintained, the GEMS size data do not exhibit any clear relationship to these crystalline components. Therefore, GEMS do not appear to have been sorted with the silicate and sulfide crystals. The disparate sorting trends observed in GEMS and the crystalline grains in CP IDPs present an interesting challenge for modeling early transport and accretion processes. They may indicate that several sorting mechanisms operated on these CP IDP components, or alternatively, they may simply be a reflection of different source environments.

  20. Influence of Aluminum Content on Grain Refinement and Strength of AZ31 Magnesium GTA Weld Metal

    SciTech Connect (OSTI)

    Babu, N. Kishore; Cross, Carl E.

    2012-06-28

    The goal is to characterize the effect of Al content on AZ31 weld metal, the grain size and strength, and examine role of Al on grain refinement. The approach is to systematically vary the aluminum content of AZ31 weld metal, Measure average grain size in weld metal, and Measure cross-weld tensile properties and hardness. Conclusions are that: (1) increased Al content in AZ31 weld metal results in grain refinement Reason: higher undercooling during solidification; (2) weld metal grain refinement resulted in increased strength & hardness Reason: grain boundary strengthening; and (3) weld metal strength can be raised to wrought base metal levels.

  1. Grain Accumulation of Selenium Species in Rice (Oryza sativa L.)

    SciTech Connect (OSTI)

    Carey, Anne-Marie; Scheckel, Kirk G.; Lombi, Enzo; Newville, Matt; Choi, Yongseong; Norton, Gareth J.; Price, Adam H.; Meharg, Andrew A.

    2012-09-05

    Efficient Se biofortification programs require a thorough understanding of the accumulation and distribution of Se species within the rice grain. Therefore, the translocation of Se species to the filling grain and their spatial unloading were investigated. Se species were supplied via cut flag leaves of intact plants and excised panicle stems subjected to a {+-} stem-girdling treatment during grain fill. Total Se concentrations in the flag leaves and grain were quantified by inductively coupled plasma mass spectrometry. Spatial accumulation was investigated using synchrotron X-ray fluorescence microtomography. Selenomethionine (SeMet) and selenomethylcysteine (SeMeSeCys) were transported to the grain more efficiently than selenite and selenate. SeMet and SeMeSeCys were translocated exclusively via the phloem, while inorganic Se was transported via both the phloem and xylem. For SeMet- and SeMeSeCys-fed grain, Se dispersed throughout the external grain layers and into the endosperm and, for SeMeSeCys, into the embryo. Selenite was retained at the point of grain entry. These results demonstrate that the organic Se species SeMet and SeMeSeCys are rapidly loaded into the phloem and transported to the grain far more efficiently than inorganic species. Organic Se species are distributed more readily, and extensively, throughout the grain than selenite.

  2. Vortices of self-gravitating grains in dusty plasmas

    SciTech Connect (OSTI)

    Nebbat, E.; Annou, R.

    2012-09-15

    Vortices are an attractive expression of the non-linear dynamics of fluids along with plasmas. In complex plasmas, Nebbat and Annou [Phys. Plasmas 17, 093702 (2010)] proposed a time dependent non-linear model that considers vortices as a consequence of an instability. The model is augmented hereafter by incorporating the gravitational grain-grain attraction, particle drift due to self-gravity field, self-consistent inter-particle distance, the permeability of grains along with the grain charge excess due to the non-linear dependence of the grain capacitance on its size. Effects of the latter parameters as well as the effect of grain mass to charge ratio on the characteristics of the vortex such as density are investigated.

  3. Microwave sintering of nanophase ceramics without concomitant grain growth

    DOE Patents [OSTI]

    Eastman, Jeffrey A.; Sickafus, Kurt E.; Katz, Joel D.

    1993-01-01

    A method of sintering nanocrystalline material is disclosed wherein the nanocrystalline material is microwaved to heat the material to a temperature less than about 70% of the melting point of the nanocrystalline material expressed in degrees K. This method produces sintered nanocrystalline material having a density greater than about 95% of theoretical and an average grain size not more than about 3 times the average grain size of the nanocrystalline material before sintering. Rutile TiO.sub.2 as well as various other ceramics have been prepared. Grain growth of as little as 1.67 times has resulted with densities of about 90% of theoretical.

  4. FORMATION OF SiC GRAINS IN PULSATION-ENHANCED DUST-DRIVEN WIND AROUND CARBON-RICH ASYMPTOTIC GIANT BRANCH STARS

    SciTech Connect (OSTI)

    Yasuda, Yuki; Kozasa, Takashi, E-mail: yuki@antares-a.sci.hokudai.ac.jp [Department of Natural History Sciences, Faculty of Science, Hokkaido University, Sapporo 060-0810 (Japan)

    2012-02-01

    We investigate the formation of silicon carbide (SiC) grains in the framework of dust-driven wind around pulsating carbon-rich asymptotic giant branch (C-rich AGB) stars to reveal not only the amount but also the size distribution. Two cases are considered for the nucleation process: one is the local thermal equilibrium (LTE) case where the vibration temperature of SiC clusters T{sub v} is equal to the gas temperature as usual, and another is the non-LTE case in which T{sub v} is assumed to be the same as the temperature of small SiC grains. The results of the hydrodynamical calculations for a model with stellar parameters of mass M{sub *} = 1.0 M{sub Sun }, luminosity L{sub *} = 10{sup 4} L{sub Sun }, effective temperature T{sub eff} = 2600 K, C/O ratio = 1.4, and pulsation period P = 650 days show the following: in the LTE case, SiC grains condense in accelerated outflowing gas after the formation of carbon grains, and the resulting averaged mass ratio of SiC to carbon grains of {approx}10{sup -8} is too small to reproduce the value of 0.01-0.3, which is inferred from the radiative transfer models. On the other hand, in the non-LTE case, the formation region of the SiC grains is more internal and/or almost identical to that of the carbon grains due to the so-called inverse greenhouse effect. The mass ratio of SiC to carbon grains averaged at the outer boundary ranges from 0.098 to 0.23 for the sticking probability {alpha}{sub s} = 0.1-1.0. The size distributions with the peak at {approx}0.2-0.3 {mu}m in radius cover the range of size derived from the analysis of the presolar SiC grains. Thus, the difference between the temperatures of the small cluster and gas plays a crucial role in the formation process of SiC grains around C-rich AGB stars, and this aspect should be explored for the formation process of dust grains in astrophysical environments.

  5. Effect of Engine-Out NOx Control Strategies on PM Size Distribution in Heavy-Duty Diesel Engines Developed for 2010

    Broader source: Energy.gov [DOE]

    A distinct relationship was found between engine-out and SCR-out PM distributions for single-mode testing.

  6. An examination of abnormal grain growth in low strain nickel-200

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

    Underwood, O.; Madison, J.; Martens, R. M.; Thompson, G. B.; Welsh, S.; Evans, J.

    2016-06-21

    Here, this study offers experimental observation of the effect of low strain conditions (ε < 10%) on abnormal grain growth (AGG) in Nickel-200. At such conditions, stored mechanical energy is low within the microstructure enabling one to observe the impact of increasing mechanical deformation on the early onset of AGG compared to a control, or nondeformed, equivalent sample. The onset of AGG was observed to occur at specific pairings of compressive strain and annealing temperature and an empirical relation describing the influence of thermal exposure and strain content was developed. The evolution of low-Σ coincident site lattice (CSL) boundaries andmore » overall grain size distributions are quantified using electron backscatter diffraction preceding, at onset and during ensuing AGG, whereby possible mechanisms for AGG in the low strain regime are offered and discussed.« less

  7. Observation and modeling of polycrystalline grain formation in Ge{sub 2}Sb{sub 2}Te{sub 5}

    SciTech Connect (OSTI)

    Burr, Geoffrey W.; Tchoulfian, Pierre; Topuria, Teya; Nyffeler, Clemens; Virwani, Kumar; Padilla, Alvaro; Shelby, Robert M.; Eskandari, Mona; Jackson, Bryan; Lee, Bong-Sub

    2012-05-15

    The relationship between the polycrystalline nature of phase change materials (such as Ge{sub 2}Sb{sub 2}Te{sub 5}) and the intermediate resistance states of phase change memory (PCM) devices has not been widely studied. A full understanding of such states will require knowledge of how polycrystalline grains form, how they interact with each other at various temperatures, and how the differing electrical (and thermal) characteristics within the grains and at their boundaries combine through percolation to produce the externally observed electrical (and thermal) characteristics of a PCM device. We address the first of these tasks (and introduce a vehicle for the second) by studying the formation of fcc polycrystalline grains from the as-deposited amorphous state in undoped Ge{sub 2}Sb{sub 2}Te{sub 5}. We perform ex situ transmission electron microscopy membrane experiments and then match these observations against numerical simulation. Ramped-anneal experiments show that the temperature ramp-rate strongly influences the median grain size. By truncating such ramped-anneal experiments at various peak temperatures, we convincingly demonstrate that the temperature range over which these grains are established is quite narrow. Subsequent annealing at elevated temperature appears to change these established distributions of grain sizes only slightly. Our numerical simulator--which models nuclei formation through classical nucleation theory and then tracks the subsequent time- and temperature-dependent growth of these grains--can match these experimental observations of initial grain distributions and crystallization temperature both qualitatively and quantitatively. These simulations show that the particular narrow temperature range over which crystallization occurs shifts as a function of temperature ramp-rate, which allows us to quantify the lower portions of the time-temperature-transformation map for Ge{sub 2}Sb{sub 2}Te{sub 5}. Future experiments and extensions of

  8. Isotropic Monte Carlo Grain Growth

    Energy Science and Technology Software Center (OSTI)

    2013-04-25

    IMCGG performs Monte Carlo simulations of normal grain growth in metals on a hexagonal grid in two dimensions with periodic boundary conditions. This may be performed with either an isotropic or a misorientation - and incliantion-dependent grain boundary energy.

  9. Influence of Alloy and Solidification Parameters on Grain Refinement in Aluminum Weld Metal due to Inoculation

    SciTech Connect (OSTI)

    Schempp, Philipp [BAM, Germany; Tang, Z. [BIAS, Germany; Cross, Carl E. [Los Alamos National Laboratory; Seefeld, T. [BIAS, Germany; Pittner, A. [BAM, Germany; Rethmeier, M. [BAM, Germany

    2012-06-28

    The goals are: (1) Establish how much Ti/B grain refiner is need to completely refine aluminum weld metal for different alloys and different welding conditions; (2) Characterize how alloy composition and solidification parameters affect weld metal grain refinement; and (3) Apply relevant theory to understand observed behavior. Conclusions are: (1) additions of Ti/B grain refiner to weld metal in Alloys 1050, 5083, and 6082 resulted in significant grain refinement; (2) grain refinement was more effective in GTAW than LBW, resulting in finer grains at lower Ti content - reason is limited time available for equiaxed grain growth in LBW (inability to occlude columnar grain growth); (3) welding travel speed did not markedly affect grain size within GTAW and LBW clusters; and (4) application of Hunt CET analysis showed experimental G to be on the order of the critical G{sub CET}; G{sub CET} was consistently higher for GTAW than for LBW.

  10. Role of grain size on the martensitic transformation and ultra...

    Office of Scientific and Technical Information (OSTI)

    Additional Journal Information: Journal Volume: 95; Journal Issue: C; Related Information: CHORUS Timestamp: 2016-05-06 05:43:34; Journal ID: ISSN 1359-6454 Publisher: Elsevier ...

  11. The influence of grain size on the mechanical properties ofsteel...

    Office of Scientific and Technical Information (OSTI)

    Authors: Morris Jr., J.W. Publication Date: 2001-05-01 OSTI Identifier: 861397 Report Number(s): LBNL--47875 R&D Project: 511201; TRN: US200601%%845 DOE Contract Number: ...

  12. Small-angle X-ray Scattering from Magnetic Clusters and Structural Grains

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

    in Magnetic Recording Media | Stanford Synchrotron Radiation Lightsource Small-angle X-ray Scattering from Magnetic Clusters and Structural Grains in Magnetic Recording Media Friday, July 31, 2015 Historically, areal density increases in longitudinal hard disk drive media technology have been driven by reduction of grain size. However, since its introduction in 2006, the perpendicular magnetic recording media grain size has remained more or less constant at around 9 nm. Perpendicular

  13. Ethanol's Effect on Grain Supply and Prices

    SciTech Connect (OSTI)

    2008-01-01

    This document provides graphical information about ethanol's effect on grain supply and prices, uses of corn, and grain price trends.

  14. Process for producing large grain cadmium telluride

    DOE Patents [OSTI]

    Hasoon, F.S.; Nelson, A.J.

    1996-01-16

    A process is described for producing a cadmium telluride polycrystalline film having grain sizes greater than about 20 {micro}m. The process comprises providing a substrate upon which cadmium telluride can be deposited and placing that substrate within a vacuum chamber containing a cadmium telluride effusion cell. A polycrystalline film is then deposited on the substrate through the steps of evacuating the vacuum chamber to a pressure of at least 10{sup {minus}6} torr.; heating the effusion cell to a temperature whereat the cell releases stoichiometric amounts of cadmium telluride usable as a molecular beam source for growth of grains on the substrate; heating the substrate to a temperature whereat a stoichiometric film of cadmium telluride can be deposited; and releasing cadmium telluride from the effusion cell for deposition as a film on the substrate. The substrate then is placed in a furnace having an inert gas atmosphere and heated for a sufficient period of time at an annealing temperature whereat cadmium telluride grains on the substrate grow to sizes greater than about 20 {micro}m.

  15. Process for producing large grain cadmium telluride

    DOE Patents [OSTI]

    Hasoon, Falah S. (Arvada, CO); Nelson, Art J. (Longmont, CO)

    1996-01-01

    A process for producing a cadmium telluride polycrystalline film having grain sizes greater than about 20 .mu.m. The process comprises providing a substrate upon which cadmium telluride can be deposited and placing that substrate within a vacuum chamber containing a cadmium telluride effusion cell. A polycrystalline film is then deposited on the substrate through the steps of evacuating the vacuum chamber to a pressure of at least 10.sup.-6 torr.; heating the effusion cell to a temperature whereat the cell releases stoichiometric amounts of cadmium telluride usable as a molecular beam source for growth of grains on the substrate; heating the substrate to a temperature whereat a stoichiometric film of cadmium telluride can be deposited; and releasing cadmium telluride from the effusion cell for deposition as a film on the substrate. The substrate then is placed in a furnace having an inert gas atmosphere and heated for a sufficient period of time at an annealing temperature whereat cadmium telluride grains on the substrate grow to sizes greater than about 20 .mu.m.

  16. Correlating size and composition-dependent effects with magnetic, Mössbauer, and pair distribution function measurements in a family of catalytically active ferrite nanoparticles

    SciTech Connect (OSTI)

    Wong, Stanislaus; Papaefthymiou, Georgia C.; Lewis, Crystal S.; Han, Jinkyu; Zhang, Cheng; Li, Qiang; Shi, Chenyang; Abeykoon, A. M.Milinda; Billinge, Simon J.L.; Stach, Eric; Thomas, Justin; Guerrero, Kevin; Munayco, Pablo; Munayco, Jimmy; Scorzelli, Rosa B.; Burnham, Philip; Viescas, Arthur J; Tiano, Amanda L.

    2015-05-06

    The magnetic spinel ferrites, MFe₂O₄ (wherein 'M' = a divalent metal ion such as but not limited to Mn, Co, Zn, and Ni), represent a unique class of magnetic materials in which the rational introduction of different 'M's can yield correspondingly unique and interesting magnetic behaviors. Herein we present a generalized hydrothermal method for the synthesis of single-crystalline ferrite nanoparticles with 'M' = Mg, Fe, Co, Ni, Cu, and Zn, respectively, which can be systematically and efficaciously produced simply by changing the metal precursor. Our protocol can moreover lead to reproducible size control by judicious selection of various surfactants. As such, we have probed the effects of both (i) size and (ii) chemical composition upon the magnetic properties of these nanomaterials using complementary magnetometry and Mössbauer spectroscopy techniques. The structure of the samples was confirmed by atomic PDF analysis of X-ray and electron powder diffraction data as a function of particle size. These materials retain the bulk spinel structure to the smallest size (i.e., 3 nm). In addition, we have explored the catalytic potential of our ferrites as both (a) magnetically recoverable photocatalysts and (b) biological catalysts, and noted that many of our as-prepared ferrite systems evinced intrinsically higher activities as compared with their iron oxide analogues.

  17. Correlating size and composition-dependent effects with magnetic, Mössbauer, and pair distribution function measurements in a family of catalytically active ferrite nanoparticles

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

    Wong, Stanislaus; Papaefthymiou, Georgia C.; Lewis, Crystal S.; Han, Jinkyu; Zhang, Cheng; Li, Qiang; Shi, Chenyang; Abeykoon, A. M.Milinda; Billinge, Simon J.L.; Stach, Eric; et al

    2015-05-06

    The magnetic spinel ferrites, MFe₂O₄ (wherein 'M' = a divalent metal ion such as but not limited to Mn, Co, Zn, and Ni), represent a unique class of magnetic materials in which the rational introduction of different 'M's can yield correspondingly unique and interesting magnetic behaviors. Herein we present a generalized hydrothermal method for the synthesis of single-crystalline ferrite nanoparticles with 'M' = Mg, Fe, Co, Ni, Cu, and Zn, respectively, which can be systematically and efficaciously produced simply by changing the metal precursor. Our protocol can moreover lead to reproducible size control by judicious selection of various surfactants. Asmore » such, we have probed the effects of both (i) size and (ii) chemical composition upon the magnetic properties of these nanomaterials using complementary magnetometry and Mössbauer spectroscopy techniques. The structure of the samples was confirmed by atomic PDF analysis of X-ray and electron powder diffraction data as a function of particle size. These materials retain the bulk spinel structure to the smallest size (i.e., 3 nm). In addition, we have explored the catalytic potential of our ferrites as both (a) magnetically recoverable photocatalysts and (b) biological catalysts, and noted that many of our as-prepared ferrite systems evinced intrinsically higher activities as compared with their iron oxide analogues.« less

  18. ACTIVATION ENERGY FOR GRAIN GROWTH IN BISMUTH COATINGS

    SciTech Connect (OSTI)

    Jankowski, A F; Hayes, J P; Smith, R F; Reed, B W; Kumar, M; Colvin, J D

    2005-09-09

    The knowledge of both activation energy and diffusion coefficient is needed for a predictive processing of grain size in coatings. However, for metals as Bismuth there is insufficient information available in the literature for these parameters. To determine these values, a method is adopted wherein an examination of the grain size is conducted for coatings deposited isothermally. The exponent for grain growth with time is determined, thereby enabling quantification of the activation energy and diffusion coefficient. Bismuth coatings that range from 10 {micro}m to 1 mm thick are deposited using electron-beam evaporation onto temperature-controlled substrate surfaces of glass and lithium fluoride. The grain size of each coating is measured upon examination of the microstructure in cross-section using the intercept method. Ideal grain growth is observed over the experimental range of deposition temperatures examined from 317 to 491 K. The activation energy (Q) for grain growth in bismuth is fit as 0.47 eV {center_dot} atom{sup -1} with a diffusion coefficient (D{sub 0}) of 3.3 x 10{sup -4} cm{sup 2} {center_dot} sec{sup -1}.

  19. Supplying materials needed for grain growth characterizations of nano-grained UO2

    SciTech Connect (OSTI)

    Mo, Kun; Miao, Yinbin; Yun, Di; Jamison, Laura M.; Lian, Jie; Yao, Tiankei

    2015-09-30

    This activity is supported by the US Nuclear Energy Advanced Modeling and Simulation (NEAMS) Fuels Product Line (FPL) and aims at providing experimental data for the validation of the mesoscale simulation code MARMOT. MARMOT is a mesoscale multiphysics code that predicts the coevolution of microstructure and properties within reactor fuel during its lifetime in the reactor. It is an important component of the Moose-Bison-Marmot (MBM) code suite that has been developed by Idaho National Laboratory (INL) to enable next generation fuel performance modeling capability as part of the NEAMS Program FPL. In order to ensure the accuracy of the microstructure based materials models being developed within the MARMOT code, extensive validation efforts must be carried out. In this report, we summarize our preliminary synchrotron radiation experiments at APS to determine the grain size of nanograin UO2. The methodology and experimental setup developed in this experiment can directly apply to the proposed in-situ grain growth measurements. The investigation of the grain growth kinetics was conducted based on isothermal annealing and grain growth characterization as functions of duration and temperature. The kinetic parameters such as activation energy for grain growth for UO2 with different stoichiometry are obtained and compared with molecular dynamics (MD) simulations.

  20. Determination of lateral size distribution of type-II ZnTe/ZnSe stacked submonolayer quantum dots via spectral analysis of optical signature of the Aharanov-Bohm excitons

    SciTech Connect (OSTI)

    Ji, Haojie; Dhomkar, Siddharth; Roy, Bidisha; Kuskovsky, Igor L.; Shuvayev, Vladimir; Deligiannakis, Vasilios; Tamargo, Maria C.; Ludwig, Jonathan; Smirnov, Dmitry; Wang, Alice

    2014-10-28

    For submonolayer quantum dot (QD) based photonic devices, size and density of QDs are critical parameters, the probing of which requires indirect methods. We report the determination of lateral size distribution of type-II ZnTe/ZnSe stacked submonolayer QDs, based on spectral analysis of the optical signature of Aharanov-Bohm (AB) excitons, complemented by photoluminescence studies, secondary-ion mass spectroscopy, and numerical calculations. Numerical calculations are employed to determine the AB transition magnetic field as a function of the type-II QD radius. The study of four samples grown with different tellurium fluxes shows that the lateral size of QDs increases by just 50%, even though tellurium concentration increases 25-fold. Detailed spectral analysis of the emission of the AB exciton shows that the QD radii take on only certain values due to vertical correlation and the stacked nature of the QDs.

  1. The impact of size distribution assumptions in a bulk one-moment microphysics scheme on simulated surface precipitation and storm dynamics during a low-topped supercell case in Belgium

    SciTech Connect (OSTI)

    Van Weverberg, K.; VanLipzig, N. P. M.; Delobbe, L.

    2011-04-01

    In this research the impact of modifying the size distribution assumptions of the precipitating hydrometeors in a bulk one-moment microphysics scheme on simulated surface precipitation and storm dynamics has been explored for long-lived low-topped supercells in Belgium. It was shown that weighting the largest precipitating ice species of the microphysics scheme to small graupel results in an increase of surface precipitation because of counteracting effects. On the one hand, the precipitation formation process slowed down, resulting in lower precipitation efficiency. On the other hand, latent heat release associated with freezing favored more intense storms. In contrast to previous studies finding decreased surface precipitation when graupel was present in the microphysics parameterization, storms were rather shallow in the authors simulations. This left little time for graupel sublimation. The impact of size distribution assumptions of snow was found to be small, but more realistic size distribution assumptions of rain led to the strongest effect on surface precipitation. Cold pools shrunk because of weaker rain evaporation at the cold pool boundaries, leading to a decreased surface rain area.

  2. Effect of gravity on three-dimensional coordination number distribution in liquid phase sintered microstructures

    SciTech Connect (OSTI)

    Tewari, A.; Gokhale, A.M.; Gereman, R.M.

    1999-10-08

    Gravity affects microstructural evolution when a liquid phase is present during sintering. The effect of gravity on the three-dimensional coordination number distribution of tungsten grains in liquid phase sintered heavy alloy specimens is quantitatively characterized. A combination of montage serial sectioning, digital image processing, and unbiased stereological sampling procedures is used to estimate the coordination number distribution in three-dimensional microstructures. The microgravity environment decreases the mean coordination number. However, hardly any isolated grains are observed in the specimens, liquid phase sintered in a microgravity environment. The effect of microgravity on the coordination numbers mainly resides in its effect on the mean coordination number. In all specimens, there is a strong correlation between grain size and coordination number, which can be expressed as [D{sub c}/{bar D}]{sup 2} = C/C{sub 0} where C{sub 0} is the mean coordination number, {bar D} the global average size of the tungsten grains, and D{sub c} the average size of only those grains which have coordination number C.

  3. Microstructure of warm rolling and pearlitic transformation of ultrafine-grained GCr15 steel

    SciTech Connect (OSTI)

    Sun, Jun-Jie; Lian, Fu-Liang; Liu, Hong-Ji; Jiang, Tao; Guo, Sheng-Wu; Du, Lin-Xiu; Liu, Yong-Ning

    2014-09-15

    Pearlitic transformation mechanisms have been investigated in ultra-fine grained GCr15 steel. The ultrafine-grained steel, whose grain size was less than 1 μm, was prepared by thermo-mechanical treatment at 873 K and then annealing at 923 K for 2 h. Pearlitic transformation was conducted by reheating the ultra-fine grained samples at 1073 K and 1123 K for different periods of time and then cooling in air. Scanning electron microscope observation shows that normal lamellar pearlite, instead of granular cementite and ferrite, cannot be formed when the grain size is approximately less than 4(± 0.6) μm, which yields a critical grain size for normal lamellar pearlitic transformations in this chromium alloyed steel. The result confirms that grain size has a great influence on pearlitic transformation by increasing the diffusion rate of carbon atoms in the ultra-fine grained steel, and the addition of chromium element doesn't change this pearlitic phase transformation rule. Meanwhile, the grain growth rate is reduced by chromium alloying, which is beneficial to form fine grains during austenitizing, thus it facilitating pearlitic transformation by divorced eutectoid transformation. Moreover, chromium element can form a relatively high gradient in the frontier of the undissolved carbide, which promotes carbide formation in the frontier of the undissolved carbide, i.e., chromium promotes divorced eutectoid transformation. - Highlights: • Ultrafine-grained GCr15 steel was obtained by warm rolling and annealing technology. • Reduction of grain size makes pearlite morphology from lamellar to granular. • Adding Cr does not change normal pearlitic phase transformation rule in UFG steel. • Cr carbide resists grain growth and facilitates pearlitic transformation by DET.

  4. Method of making fine-grained triaminotrinitrobenzene

    DOE Patents [OSTI]

    Benziger, Theodore M.

    1984-01-01

    A method of forming a fine-grained species of the insensitive high explosive sym-triaminotrinitrobenzene (TATB) without grinding. In accordance with the method, 1,3,5-trichloro-2,4,6-trinitrobenzene (TCTNB) is aminated by reaction with gaseous ammonia in an emulsion of toluene in water. The ratio of water to toluene in the emulsion is selected so that toluene is the dispersed phase in the emulsion. The size of the dispersed TCTNB-containing toluene droplets determines the particle size of the resulting TATB. The emulsion is preferably formed with an emulsifier such as ammonium oleate, which may be generated in situ from oleic acid, and stabilized with a protective colloid such as polyvinyl alcohol.

  5. Method of making fine-grained triaminotrinitrobenzene

    DOE Patents [OSTI]

    Benziger, T.M.

    1983-07-26

    A method is given for forming a fine-grained species of the insensitive high explosive sym-triaminotrinitrobenzene (TATB) without grinding. In accordance with the method, 1,3,5-trichloro-2,4,6-trinitrobenzene (TCTNB) is aminated by reaction with gaseous ammonia in an emulsion of toluene in water. The ratio of water to toluene in the emulsion is selected so that toluene is the dispersed phase in the emulsion. The size of the dispersed TCTNB-containing toluene droplets determines the particle size of the resulting TATB. The emulsion is preferably formed with an emulsifier such as ammonium oleate, which may be generated in situ from oleic acid, and stabilized with a protective colloid such as polyvinyl alcohol.

  6. The Effect Of Electronic Energy Loss On Irradiation-induced Grain Growth In Nanocrystalline Oxides

    SciTech Connect (OSTI)

    Zhang, Yanwen; Aidhy, Dilpuneet S.; Varga, Tamas; Moll, Sandra; Edmondson, Philip D.; Namavar, Fereydoon; Jin, Ke; Ostrouchov, Christopher N.; Weber, William J.

    2014-03-03

    Grain growth of nanocrystalline materials is generally thermally activated, but can also be driven by irradiation at much lower temperature. In nanocrystalline ceria and zirconia, energetic ions deposit their energy to both atomic nuclei and electrons. Our experimental results have shown that irradiationinduced grain growth is dependent on the total energy deposited, where electronic energy loss and elastic collisions between atomic nuclei both contribute to the production of disorder and grain growth. Our atomistic simulations reveal that a high density of disorder near grain boundaries leads to locally rapid grain movement. The additive effect from both electronic excitation and atomic collision cascades on grain growth demonstrated in this work opens up new possibilities for controlling grain sizes to improve functionality of nanocrystalline materials.

  7. Investigation of thermochemical biorefinery sizing and environmental sustainability impacts for conventional supply system and distributed pre-processing supply system designs

    SciTech Connect (OSTI)

    David J. Muth, Jr.; Matthew H. Langholtz; Eric C. D. Tan; Jacob J. Jacobson; Amy Schwab; May M. Wu; Andrew Argo; Craig C. Brandt; Kara G. Cafferty; Yi-Wen Chiu; Abhijit Dutta; Laurence M. Eaton; Erin M. Searcy

    2014-08-01

    The 2011 US Billion-Ton Update estimates that by 2030 there will be enough agricultural and forest resources to sustainably provide at least one billion dry tons of biomass annually, enough to displace approximately 30% of the country's current petroleum consumption. A portion of these resources are inaccessible at current cost targets with conventional feedstock supply systems because of their remoteness or low yields. Reliable analyses and projections of US biofuels production depend on assumptions about the supply system and biorefinery capacity, which, in turn, depend upon economic value, feedstock logistics, and sustainability. A cross-functional team has examined combinations of advances in feedstock supply systems and biorefinery capacities with rigorous design information, improved crop yield and agronomic practices, and improved estimates of sustainable biomass availability. A previous report on biochemical refinery capacity noted that under advanced feedstock logistic supply systems that include depots and pre-processing operations there are cost advantages that support larger biorefineries up to 10 000 DMT/day facilities compared to the smaller 2000 DMT/day facilities. This report focuses on analyzing conventional versus advanced depot biomass supply systems for a thermochemical conversion and refinery sizing based on woody biomass. The results of this analysis demonstrate that the economies of scale enabled by advanced logistics offsets much of the added logistics costs from additional depot processing and transportation, resulting in a small overall increase to the minimum ethanol selling price compared to the conventional logistic supply system. While the overall costs do increase slightly for the advanced logistic supply systems, the ability to mitigate moisture and ash in the system will improve the storage and conversion processes. In addition, being able to draw on feedstocks from further distances will decrease the risk of biomass supply to the

  8. Dense, finely, grained composite materials

    DOE Patents [OSTI]

    Dunmead, Stephen D. (Davis, CA); Holt, Joseph B. (San Jose, CA); Kingman, Donald D. (Danville, CA); Munir, Zuhair A. (Davis, CA)

    1990-01-01

    Dense, finely grained composite materials comprising one or more ceramic phase or phase and one or more metallic and/or intermetallic phase or phases are produced by combustion synthesis. Spherical ceramic grains are homogeneously dispersed within the matrix. Methods are provided, which include the step of applying mechanical pressure during or immediately after ignition, by which the microstructures in the resulting composites can be controllably selected.

  9. Grenoble Alpes Incubation GRAIN | Open Energy Information

    Open Energy Info (EERE)

    GRAIN Jump to: navigation, search Name: Grenoble Alpes Incubation (GRAIN) Place: France Sector: Services Product: General Financial & Legal Services ( Government Public...

  10. Heartland Grain Fuels LP | Open Energy Information

    Open Energy Info (EERE)

    Name: Heartland Grain Fuels LP Place: Aberdeen, South Dakota Zip: 57401 Sector: Bioenergy Product: Heartland Grain Fuels is a cooperatively-owned producer of corn-derived...

  11. Strain induced grain boundary migration effects on grain growth of an austenitic stainless steel during static and metadynamic recrystallization

    SciTech Connect (OSTI)

    Paggi, A.; Angella, G.; Donnini, R.

    2015-09-15

    Static and metadynamic recrystallization of an AISI 304L austenitic stainless steel was investigated at 1100 °C and 10{sup −} {sup 2} s{sup −} {sup 1} strain rate. The kinetics of recrystallization was determined through double hit compression tests. Two strain levels were selected for the first compression hit: ε{sub f} = 0.15 for static recrystallization (SRX) and 0.25 for metadynamic recrystallization (MDRX). Both the as-deformed and the recrystallized microstructures were investigated through optical microscopy and electron back-scattered diffraction (EBSD) technique. During deformation, strain induced grain boundary migration appeared to be significant, producing a square-like grain boundary structure aligned along the directions of the maximum shear stresses in compression. EBSD analysis revealed to be as a fundamental technique that the dislocation density was distributed heterogeneously in the deformed grains. Grain growth driven by surface energy reduction was also investigated, finding that it was too slow to explain the experimental data. Based on microstructural results, it was concluded that saturation of the nucleation sites occurred in the first stages of recrystallization, while grain growth driven by strain induced grain boundary migration (SIGBM) dominated the subsequent stages. - Highlights: • Recrystallization behavior of a stainless steel was investigated at 1100 °C. • EBSD revealed that the dislocation density distribution was heterogeneous during deformation. • Saturation of nucleation sites occurred in the first stages of recrystallization. • Strain induced grain boundary migration (SIGBM) effects were significant. • Grain growth driven by SIGBM dominated the subsequent stages.

  12. PERCOLATION ON GRAIN BOUNDARY NETWORKS: APPLICATION TO FISSION GAS RELEASE IN NUCLEAR FUELS

    SciTech Connect (OSTI)

    Paul C. Millett

    2012-02-01

    The percolation behavior of grain boundary networks is characterized in two- and three-dimensional lattices with circular macroscale cross-sections that correspond to nuclear fuel elements. The percolation of gas bubbles on grain boundaries, and the subsequent percolation of grain boundary networks is the primary mechanism of fission gas release from nuclear fuels. Both radial cracks and radial gradients in grain boundary property distributions are correlated with the fraction of grain boundaries vented to the free surfaces. Our results show that cracks surprisingly do not significantly increase the percolation of uniform grain boundary networks. However, for networks with radial gradients in boundary properties, the cracks can considerably raise the vented grain boundary content.

  13. Enhanced Solar Energy Absorption by Internally-mixed Black Carbon in Snow Grains

    SciTech Connect (OSTI)

    Flanner, M. G.; Liu, Xiaohong; Zhou, Cheng; Penner, Joyce E.; Jiao, C.

    2012-05-30

    Here we explore light absorption by snowpack containing black carbon (BC) particles residing within ice grains. Basic considerations of particle volumes and BC/snow mass concentrations show that there are generally 0:05-109 BC particles for each ice grain. This suggests that internal BC is likely distributed as multiple inclusions within ice grains, and thus the dynamic effective medium approximation (DEMA) (Chylek and Srivastava, 1983) is a more appropriate optical representation for BC/ice composites than coated-sphere or standard mixing approximations. DEMA calculations show that the 460 nm absorption cross-section of BC/ice composites, normalized to the mass of BC, is typically enhanced by factors of 1.8-2.1 relative to interstitial BC. BC effective radius is the dominant cause of variation in this enhancement, compared with ice grain size and BC volume fraction. We apply two atmospheric aerosol models that simulate interstitial and within-hydrometeor BC lifecycles. Although only {approx}2% of the atmospheric BC burden is cloud-borne, 71-83% of the BC deposited to global snow and sea-ice surfaces occurs within hydrometeors. Key processes responsible for within-snow BC deposition are development of hydrophilic coatings on BC, activation of liquid droplets, and subsequent snow formation through riming or ice nucleation by other species and aggregation/accretion of ice particles. Applying deposition fields from these aerosol models in offline snow and sea-ice simulations, we calculate that 32-73% of BC in global surface snow resides within ice grains. This fraction is smaller than the within-hydrometeor deposition fraction because meltwater flux preferentially removes internal BC, while sublimation and freezing within snowpack expose internal BC. Incorporating the DEMA into a global climate model, we simulate increases in BC/snow radiative forcing of 43-86%, relative to scenarios that apply external optical properties to all BC. We show that snow metamorphism

  14. Characterizing Uncertainties in Ice Particle Size Distributions

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

    and image(s), see ARM Research Highlights http:www.arm.govsciencehighlights Research Highlight In many parameterization schemes for numerical models or remote sensing...

  15. Size distributions of boundary-layer clouds

    SciTech Connect (OSTI)

    Stull, R.; Berg, L.; Modzelewski, H.

    1996-04-01

    Scattered fair-weather clouds are triggered by thermals rising from the surface layer. Not all surface layer air is buoyant enough to rise. Also, each thermal has different humidities and temperatures, resulting in interthermal variability of their lifting condensation levels (LCL). For each air parcel in the surface layer, it`s virtual potential temperature and it`s LCL height can be computed.

  16. ARM - Measurement - Aerosol particle size distribution

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

    AOS : Aerosol Observing System CSPHOT : Cimel Sunphotometer HTDMA : Humidified Tandem Differential Mobility Analyzer SMPS : Scanning mobility particle sizer TDMA : Tandem...

  17. Friction stir weld tools having fine grain structure

    DOE Patents [OSTI]

    Grant, Glenn J.; Frye, John G.; Kim, Jin Yong; Lavender, Curt A.; Weil, Kenneth Scott

    2016-03-15

    Tools for friction stir welding can be made with fewer process steps, lower cost techniques, and/or lower cost ingredients than other state-of-the-art processes by utilizing improved compositions and processes of fabrication. Furthermore, the tools resulting from the improved compositions and processes of fabrication can exhibit better distribution and homogeneity of chemical constituents, greater strength, and/or increased durability. In one example, a friction stir weld tool includes tungsten and rhenium and is characterized by carbide and oxide dispersoids, by carbide particulates, and by grains that comprise a solid solution of the tungsten and rhenium. The grains do not exceed 10 micrometers in diameter.

  18. Unraveling irradiation induced grain growth with in situ transmission electron microscopy and coordinated modeling

    SciTech Connect (OSTI)

    Bufford, D. C.; Abdeljawad, F. F.; Foiles, S. M.; Hattar, K.

    2015-11-09

    Nanostructuring has been proposed as a method to enhance radiation tolerance, but many metallic systems are rejected due to significant concerns regarding long term grain boundary and interface stability. This work utilized recent advancements in transmission electron microscopy (TEM) to quantitatively characterize the grain size, texture, and individual grain boundary character in a nanocrystalline gold model system before and after in situ TEM ion irradiation with 10 MeV Si. The initial experimental measurements were fed into a mesoscale phase field model, which incorporates the role of irradiation-induced thermal events on boundary properties, to directly compare the observed and simulated grain growth with varied parameters. The observed microstructure evolution deviated subtly from previously reported normal grain growth in which some boundaries remained essentially static. In broader terms, the combined experimental and modeling techniques presented herein provide future avenues to enhance quantification and prediction of the thermal, mechanical, or radiation stability of grain boundaries in nanostructured crystalline systems.

  19. Relative entropy and optimization-driven coarse-graining methods in VOTCA

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

    Mashayak, S. Y.; Jochum, Mara N.; Koschke, Konstantin; Aluru, N. R.; Rühle, Victor; Junghans, Christoph; Huang, Xuhui

    2015-07-20

    We discuss recent advances of the VOTCA package for systematic coarse-graining. Two methods have been implemented, namely the downhill simplex optimization and the relative entropy minimization. We illustrate the new methods by coarse-graining SPC/E bulk water and more complex water-methanol mixture systems. The CG potentials obtained from both methods are then evaluated by comparing the pair distributions from the coarse-grained to the reference atomistic simulations.We have also added a parallel analysis framework to improve the computational efficiency of the coarse-graining process.

  20. Diffusion coefficients of Fokker-Planck equation for rotating dust grains in a fusion plasma

    SciTech Connect (OSTI)

    Bakhtiyari-Ramezani, M. Alinejad, N.; Mahmoodi, J.

    2015-11-15

    In the fusion devices, ions, H atoms, and H{sub 2} molecules collide with dust grains and exert stochastic torques which lead to small variations in angular momentum of the grain. By considering adsorption of the colliding particles, thermal desorption of H atoms and normal H{sub 2} molecules, and desorption of the recombined H{sub 2} molecules from the surface of an oblate spheroidal grain, we obtain diffusion coefficients of the Fokker-Planck equation for the distribution function of fluctuating angular momentum. Torque coefficients corresponding to the recombination mechanism show that the nonspherical dust grains may rotate with a suprathermal angular velocity.

  1. GRAIN REFINEMENT OF URANIUM BILLETS

    DOE Patents [OSTI]

    Lewis, L.

    1964-02-25

    A method of refining the grain structure of massive uranium billets without resort to forging is described. The method consists in the steps of beta- quenching the billets, annealing the quenched billets in the upper alpha temperature range, and extrusion upset of the billets to an extent sufficient to increase the cross sectional area by at least 5 per cent. (AEC)

  2. In-service Inspection Ultrasonic Testing of Reactor Pressure Vessel Welds for Assessing Flaw Density and Size Distribution per 10 CFR 50.61a, Alternate Fracture Toughness Requirements

    SciTech Connect (OSTI)

    Sullivan, Edmund J.; Anderson, Michael T.; Norris, Wallace

    2012-09-17

    Pressurized thermal shock (PTS) events are system transients in a pressurized water reactor (PWR) in which there is a rapid operating temperature cool-down that results in cold vessel temperatures with or without repressurization of the vessel. The rapid cooling of the inside surface of the reactor pressure vessel (RPV) causes thermal stresses that can combine with stresses caused by high pressure. The aggregate effect of these stresses is an increase in the potential for fracture if a pre-existing flaw is present in a material susceptible to brittle failure. The ferritic, low alloy steel of the reactor vessel beltline adjacent to the core, where neutron radiation gradually embrittles the material over the lifetime of the plant, can be susceptible to brittle fracture. The PTS rule, described in the Code of Federal Regulations, Title 10, Section 50.61 (§50.61), “Fracture Toughness Requirements for Protection against Pressurized Thermal Shock Events,” adopted on July 23, 1985, establishes screening criteria to ensure that the potential for a reactor vessel to fail due to a PTS event is deemed to be acceptably low. The U.S. Nuclear Regulatory Commission (NRC) completed a research program that concluded that the risk of through-wall cracking due to a PTS event is much lower than previously estimated. The NRC subsequently developed a rule, §50.61a, published on January 4, 2010, entitled “Alternate Fracture Toughness Requirements for Protection Against Pressurized Thermal Shock Events” (75 FR 13). Use of the new rule by licensees is optional. The §50.61a rule differs from §50.61 in that it requires licensees who choose to follow this alternate method to analyze the results from periodic volumetric examinations required by the ASME Code, Section XI, Rules for Inservice Inspection (ISI) of Nuclear Power Plants. These analyses are intended to determine if the actual flaw density and size distribution in the licensee’s reactor vessel beltline welds are bounded

  3. Optical method for the determination of grain orientation in films

    DOE Patents [OSTI]

    Maris, Humphrey J.

    2001-01-01

    A method for the determination of grain orientation in a film sample is provided comprising the steps of measuring a first transient optical response of the film and determining the contribution to the transient optical response arising from a change in the energy distribution of the electrons in the sample, determining the contribution to the transient optical response arising from a propagating strain pulse within the sample, and determining the contribution to the transient optical response arising from a change in sample temperature of the sample. The grain orientation of the sample may be determined using the contributions to the transient optical response arising from the change in the energy distribution of the electrons, the propagating strain pulse, and the change in sample temperature. Additionally, a method for determination of the thickness of a film sample is provided. The grain orientation of the sample is first determined. The grain orientation, together with the velocity of sound and a propagation time of a strain pulse through the sample are then used to determine the thickness of the film sample.

  4. Optical method for the determination of grain orientation in films

    DOE Patents [OSTI]

    Maris, Humphrey J.

    2003-05-13

    A method for the determination of grain orientation in a film sample is provided comprising the steps of measuring a first transient optical response of the film and determining the contribution to the transient optical response arising from a change in the energy distribution of the electrons in the sample, determining the contribution to the transient optical response arising from a propagating strain pulse within the sample, and determining the contribution to the transient optical response arising from a change in sample temperature of the sample. The grain orientation of the sample may be determined using the contributions to the transient optical response arising from the change in the energy distribution of the electrons, the propagating strain pulse, and the change in sample temperature. Additionally, a method for determination of the thickness of a film sample is provided. The grain orientation of the sample is first determined. The grain orientation, together with the velocity of sound and a propagation time of a strain pulse through the sample are then used to determine the thickness of the film sample.

  5. Grain growth and phase stability of nanocrystalline cubic zirconia under ion irradiation

    SciTech Connect (OSTI)

    Zhang, Yanwen; Jiang, Weilin; Wang, Chong M.; Namavar, Fereydoon; Edmondson, Philip D.; Zhu, Zihua; Gao, Fei; Lian, Jie; Weber, William J.

    2010-11-10

    Grain growth, oxygen stoichiometry and phase stability of nanostructurally-stabilized zirconia (NSZ) in pure cubic phase are investigated under 2 MeV Au ion bombardment at 160 and 400 K to doses up to 35 displacements per atom (dpa). The NSZ films are produced by ion-beam-assisted deposition technique at room temperature with an average grain size of 7.7 nm. The grain size increases with dose, and follows a power law (n=6) to a saturation value of ~30 nm that decreases with temperature. Slower grain growth is observed under 400 K irradiations, as compared to 160 K irradiations, indicating that thermal grain growth is not activated and defect-stimulated grain growth is the dominating mechanism. While cubic phase is perfectly retained and no new phases are identified after the high-dose irradiations, reduction of oxygen in the irradiated NSZ films is detected. The ratio of O to Zr decreases from ~2.0 for the as-deposited films to ~1.65 after irradiation to ~35 dpa. Significant increase of oxygen vacancies in nanocrystalline zirconia suggests substantially enhanced oxygen diffusion under ion irradiation, a materials behavior far from equilibrium. The oxygen deficiency may be essential in stabilizing cubic phase to larger grain sizes.

  6. Grain Growth and Phase Stability of Nanocrystalline Cubic Zirconia under Ion Irradiation

    SciTech Connect (OSTI)

    Zhang, Yanwen; Jiang, Weilin; Wang, Chongmin; Namavar, Fereydoon; Edmondson, Philip D.; Zhu, Zihua; Gao, Fei; Lian, Jie; Weber, William J

    2010-01-01

    Grain growth, oxygen stoichiometry and phase stability of nanostructurally-stabilized cubic zirconia (NSZ) are investigated under 2 MeV Au ion bombardment at 160 and 400 K to doses up to 35 displacements per atom (dpa). The NSZ films are produced by ion-beam-assisted deposition technique at room temperature with an average grain size of 7.7 nm. The grain size increases with dose, and follows a power law (n=6) to a saturation value of ~30 nm that decreases with temperature. Slower grain growth is observed under 400 K irradiations, as compared to 160 K irradiations, indicating that the grain growth is not thermally activated and irradiation-induced grain growth is the dominating mechanism. While the cubic structure is retained and no new phases are identified after the high-dose irradiations, oxygen reduction in the irradiated NSZ films is detected. The ratio of O to Zr decreases from ~2.0 for the as-deposited films to ~1.65 after irradiation to ~35 dpa. The loss of oxygen suggests a significant increase of oxygen vacancies in nanocrystalline zirconia under ion irradiation. The oxygen deficiency may be essential in stabilizing the cubic phase to larger grain sizes.

  7. Investigation of thermochemical biorefinery sizing and environmental...

    Office of Scientific and Technical Information (OSTI)

    Investigation of thermochemical biorefinery sizing and environmental sustainability impacts for conventional supply system and distributed pre-processing supply system designs...

  8. The formation of molecular hydrogen on silicate dust analogs: The rotational distribution

    SciTech Connect (OSTI)

    Gavilan, L.; Lemaire, J. L.; Vidali, G.; Sabri, T.; Jger, C.

    2014-02-01

    Our laboratory experiments continue to explore how the formation of molecular hydrogen is influenced by dust and how dust thereby affects hydrogen molecules adsorbed on its surface. In Sabri et al., we present the preparation of nanometer-sized silicate grain analogs via laser ablation. These analogs illustrate extremes in structure (fully crystalline or fully amorphous grains), and stoichiometry (the forsterite and fayalite end-members of the olivine family). These were inserted in FORMOLISM, an ultra-high vacuum setup where they can be cooled down to ?5 K. Atomic beams are directed at these surfaces and the formation of new molecules is studied via REMPI(2+1) spectroscopy. We explored the rotational distribution (0 ? J'' ? 5) of v'' = 0 of the ground electronic state of H{sub 2}. The results of these measurements are reported here. Surprisingly, molecules formed and ejected from crystalline silicates have a cold (T {sub rot} ? 120 K) rotational energy distribution, while for molecules formed on and ejected from amorphous silicate films, the rotational temperature is ?310 K. These results are compared to previous experiments on metallic surfaces and theoretical simulations. Solid-state surface analysis suggests that flatter grains could hinder the 'cartwheel' rotation mode. A search for hot hydrogen, predicted as a result of H{sub 2} formation, hints at its production. For the first time, the rotational distribution of hydrogen molecules formed on silicate dust is reported. These results are essential to understanding the chemistry of astrophysical media containing bare dust grains.

  9. Dispersoid Distribution and Microstructure in Fe-Cr-Al Ferritic Oxide Dispersion-Strengthened Alloy Prepared by Friction Consolidation

    SciTech Connect (OSTI)

    Catalini, David; Kaoumi, Djamel; Reynolds, Anthony; Grant, Glenn J.

    2015-07-09

    INCOLOY® MA956 is a ferritic Oxide Dispersion Strengthened (ODS) alloy. Three different oxides, Y4Al2O9, YAlO3 and Y3Al5O12, have been observed in this alloy. The oxide particle sizes range from just a few up to hundreds of nm and these particles are responsible of the high temperature mechanical strength of this alloy. Mechanically alloyed MA956 powder was consolidated via Friction Consolidation using three different processing conditions. As a result, three small compacts of low porosity were produced. The compacts exhibited a refined equiaxed grain structure with grain sizes smaller than 10 µm and the desired oxide dispersion.YAlO3 and Y3Al5O12 were identified in the compacts by Scanning Electron Microscopy (SEM), Electron Dispersive Spectroscopy (EDS) and X-ray diffraction (XRD). The size distribution of precipitates above 50 nm showed a direct proportionality between average precipitate size and grain size. The total energy input during processing was correlated with the relative amount of each of the oxides in the disks: the higher the total processing energy input, the higher the relative amount of Y3Al5O12 precipitates. The elemental composition of the oxide precipitates was also probed individually by EDS showing an aluminum enrichment trend as precipitates grow in size.

  10. STOCK: Structure mapper and online coarse-graining kit for molecular simulations

    SciTech Connect (OSTI)

    Bevc, Staš; Junghans, Christoph; Praprotnik, Matej

    2015-03-15

    We present a web toolkit STructure mapper and Online Coarse-graining Kit for setting up coarse-grained molecular simulations. The kit consists of two tools: structure mapping and Boltzmann inversion tools. The aim of the first tool is to define a molecular mapping from high, e.g. all-atom, to low, i.e. coarse-grained, resolution. Using a graphical user interface it generates input files, which are compatible with standard coarse-graining packages, e.g. VOTCA and DL_CGMAP. Our second tool generates effective potentials for coarse-grained simulations preserving the structural properties, e.g. radial distribution functions, of the underlying higher resolution model. The required distribution functions can be provided by any simulation package. Simulations are performed on a local machine and only the distributions are uploaded to the server. The applicability of the toolkit is validated by mapping atomistic pentane and polyalanine molecules to a coarse-grained representation. Effective potentials are derived for systems of TIP3P (transferable intermolecular potential 3 point) water molecules and salt solution. The presented coarse-graining web toolkit is available at http://stock.cmm.ki.si.

  11. STOCK: Structure mapper and online coarse-graining kit for molecular simulations

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

    Bevc, Staš; Junghans, Christoph; Praprotnik, Matej

    2015-03-15

    We present a web toolkit STructure mapper and Online Coarse-graining Kit for setting up coarse-grained molecular simulations. The kit consists of two tools: structure mapping and Boltzmann inversion tools. The aim of the first tool is to define a molecular mapping from high, e.g. all-atom, to low, i.e. coarse-grained, resolution. Using a graphical user interface it generates input files, which are compatible with standard coarse-graining packages, e.g. VOTCA and DL_CGMAP. Our second tool generates effective potentials for coarse-grained simulations preserving the structural properties, e.g. radial distribution functions, of the underlying higher resolution model. The required distribution functions can be providedmore » by any simulation package. Simulations are performed on a local machine and only the distributions are uploaded to the server. The applicability of the toolkit is validated by mapping atomistic pentane and polyalanine molecules to a coarse-grained representation. Effective potentials are derived for systems of TIP3P (transferable intermolecular potential 3 point) water molecules and salt solution. The presented coarse-graining web toolkit is available at http://stock.cmm.ki.si.« less

  12. Suppression of Twinning and Phase Transformation in an Ultrafine Grained 2 GPa Strong Metastable Austenitic Steel: Experiment and Simulation

    SciTech Connect (OSTI)

    Shen, Yongfeng; Jia, Nan; Wang, Y. D.; Sun, Xin; Zuo, Liang; Raabe, Dierk

    2015-07-17

    An ultrafine-grained 304 austenitic 18 wt.%Cr-8 wt.%Ni stainless steel with a grain size of ~270 nm was synthesized by accumulative rolling (67 % total reduction) and annealing (550 °C, 150s). Uniaxial tensile testing at room temperature reveals an extremely high yield strength of 1890 ± 50MPa and a tensile strength of 2050 ± 30MPa, while the elongation reaches 6 ± 1%. Experimental characterization on samples with different grain sizes between 270 nm and 35 μm indicates that both, deformation twinning and martensitic phase transformation are significantly retarded with increasing grain refinement. A crystal plasticity finite element model incorporating a constitutive law reflecting the grain size-controlled dislocation slip and deformation twinning captures the micromechanical behavior of the steels with different grain sizes. Comparison of simulation and experiment shows that the deformation of ultrafine-grained 304 steels is dominated by the slip of partial dislocations, whereas for coarse-grained steels dislocation slip, twinning and martensite formation jointly contribute to the shape change.

  13. The rule of the stock distribution with large bell in blast furnace

    SciTech Connect (OSTI)

    Liu Yuncai

    1996-12-31

    This paper describes in detail, starting from the basic equation of materials falling from a two bell furnace top system, how a number of mathematical expressions which govern the stock distribution of the throat were derived. An analysis was then made by applying these equations on topics, such as stockline levels, charging sequences, stock grain size, large bell angle and batch weight. This demonstrates that a reasonable two bells top charging system and practice could be established theoretically. Furthermore, character numbers for stock distribution, such as E{sub B} and D{sub K}, were developed for a possible computer application.

  14. Irradiation behaviour of the large grained UO{sub 2} fuel pellet in the transient conditions

    SciTech Connect (OSTI)

    Kosaka, Yuji; Watanabe, Seiichi; Arakawa, Yasushi

    2007-07-01

    In order to achieve a high duty fuel rod design, it is the key issue to suppress the fission gas release from the view point of the fuel rod inner pressure design. The large grain UO{sub 2} pellet is one of the candidates to meet such a requirement by reducing the fission gas release especially at high power and/or high burnup. We have demonstrated the fuel performance of the large grain pellet in the PWR irradiation conditions, which was fabricated with no additive but with active UO{sub 2} powder through the conventional pelletizing process for the normal grain size pellet. According to the mechanism of the fission gas retention, there may be a concern about the larger gas bubble swelling of the large grain pellet at the power transient conditions which may increase the potential of the PCMI failure. In this paper, we focus on the differences of the dimensional change in comparison among the pellets with the different grain sizes at the power transient conditions. The power ramp tests were carried out on the high burnup fuel rods of normal and large grain pellet with no additive, which had been irradiated in the PWR conditions up to around 60 GWd/t at peak position. The detailed PIE results revealed that the volume increment due to the power ramp clearly showed the dependence on the grain size as well as the fission gas release and suggested that the larger grain with no additive may suppress the gas bubble swelling at the power transient conditions. According to the experimental results, it is concluded that the large grain pellet with no additive does not deteriorate the irradiation performance during the power transient conditions from the view point of the gas bubble swelling. (authors)

  15. Grain alignment in starless cores

    SciTech Connect (OSTI)

    Jones, T. J.; Bagley, M.; Krejny, M.; Andersson, B.-G.; Bastien, P.

    2015-01-01

    We present near-IR polarimetry data of background stars shining through a selection of starless cores taken in the K band, probing visual extinctions up to A{sub V}∼48. We find that P{sub K}/τ{sub K} continues to decline with increasing A{sub V} with a power law slope of roughly −0.5. Examination of published submillimeter (submm) polarimetry of starless cores suggests that by A{sub V}≳20 the slope for P versus τ becomes ∼−1, indicating no grain alignment at greater optical depths. Combining these two data sets, we find good evidence that, in the absence of a central illuminating source, the dust grains in dense molecular cloud cores with no internal radiation source cease to become aligned with the local magnetic field at optical depths greater than A{sub V}∼20. A simple model relating the alignment efficiency to the optical depth into the cloud reproduces the observations well.

  16. Effective porosity and pore-throat sizes of Conasauga Group mudrock: Application, test and evaluation of petrophysical techniques

    SciTech Connect (OSTI)

    Dorsch, J.; Katsube, T.J.; Sanford, W.E.; Dugan, B.E.; Tourkow, L.M.

    1996-04-01

    Effective porosity (specifically referring to the interconnected pore space) was recently recognized as being essential in determining the effectiveness and extent of matrix diffusion as a transport mechanism within fractured low-permeability rock formations. The research presented in this report was performed to test the applicability of several petrophysical techniques for the determination of effective porosity of fine-grained siliciclastic rocks. In addition, the aim was to gather quantitative data on the effective porosity of Conasauga Group mudrock from the Oak Ridge Reservation (ORR). The quantitative data reported here include not only effective porosities based on diverse measurement techniques, but also data on the sizes of pore throats and their distribution, and specimen bulk and grain densities. The petrophysical techniques employed include the immersion-saturation method, mercury and helium porosimetry, and the radial diffusion-cell method.

  17. Aerosol mobility size spectrometer

    DOE Patents [OSTI]

    Wang, Jian; Kulkarni, Pramod

    2007-11-20

    A device for measuring aerosol size distribution within a sample containing aerosol particles. The device generally includes a spectrometer housing defining an interior chamber and a camera for recording aerosol size streams exiting the chamber. The housing includes an inlet for introducing a flow medium into the chamber in a flow direction, an aerosol injection port adjacent the inlet for introducing a charged aerosol sample into the chamber, a separation section for applying an electric field to the aerosol sample across the flow direction and an outlet opposite the inlet. In the separation section, the aerosol sample becomes entrained in the flow medium and the aerosol particles within the aerosol sample are separated by size into a plurality of aerosol flow streams under the influence of the electric field. The camera is disposed adjacent the housing outlet for optically detecting a relative position of at least one aerosol flow stream exiting the outlet and for optically detecting the number of aerosol particles within the at least one aerosol flow stream.

  18. Cast Stainless Steel Ferrite and Grain Structure

    SciTech Connect (OSTI)

    Ruud, Clayton O.; Ramuhalli, Pradeep; Meyer, Ryan M.; Mathews, Royce; Diaz, Aaron A.; Anderson, Michael T.

    2012-09-01

    In-service inspection requirements dictate that piping welds in the primary pressure boundary of light-water reactors be subject to a volumetric examination based on the rules contained within the American Society of Mechanical Engineers Boiler and Pressure Vessel Code, Section XI. The purpose of the inspection is the reliable detection and accurate sizing of service-induced degradation and/or material flaws introduced during fabrication. The volumetric inspection is usually carried out using ultrasonic testing (UT) methods. However, the varied metallurgical macrostructures and microstructures of cast austenitic stainless steel piping and fittings, including statically cast stainless steel and centrifugally cast stainless steel (CCSS), introduce significant variations in the propagation and attenuation of ultrasonic energy. These variations complicate interpretation of the UT responses and may compromise the reliability of UT inspection. A review of the literature indicated that a correlation may exist between the microstructure and the delta ferrite content of the casting alloy. This paper discusses the results of a recent study where the goal was to determine if a correlation existed between measured and/or calculated ferrite content and grain structure in CCSS pipe.

  19. Ultrafine-grained titanium for medical implants

    DOE Patents [OSTI]

    Zhu, Yuntian T.; Lowe, Terry C.; Valiev, Ruslan Z.; Stolyarov, Vladimir V.; Latysh, Vladimir V.; Raab, Georgy J.

    2002-01-01

    We disclose ultrafine-grained titanium. A coarse-grained titanium billet is subjected to multiple extrusions through a preheated equal channel angular extrusion (ECAE) die, with billet rotation between subsequent extrusions. The resulting billet is cold processed by cold rolling and/or cold extrusion, with optional annealing. The resulting ultrafine-grained titanium has greatly improved mechanical properties and is used to make medical implants.

  20. Midwest Grain Processors MGP | Open Energy Information

    Open Energy Info (EERE)

    Midwest Grain Processors (MGP) Place: Lakota, Iowa Zip: 50451 Product: Iowa-based bioethanol producer using corn as feedstock. Coordinates: 48.042535, -98.335979 Show Map...

  1. Ethanol Grain Processors LLC | Open Energy Information

    Open Energy Info (EERE)

    Processors LLC Jump to: navigation, search Name: Ethanol Grain Processors, LLC Place: Obion, Tennessee Zip: TN 38240 Product: Tennessee-based ethanol producer. Coordinates:...

  2. Effect of martensite to austenite reversion on the formation of nano/submicron grained AISI 301 stainless steel

    SciTech Connect (OSTI)

    Karimi, M.; Najafizadeh, A.; Kermanpur, A.; Eskandari, M.

    2009-11-15

    The martensite to austenite reversion behavior of 90% cold rolled AISI 301 stainless steel was investigated in order to refine the grain size. Cold rolled specimens were annealed at 600-900 deg. C, and subsequently characterized by scanning electron microscopy, X-ray diffraction, Feritscope, and hardness measurements. The effects of annealing parameters on the formation of fully-austenitic nano/submicron grained structure and the mechanisms involved were studied. It was found that annealing at 800 deg. C for 10 s exhibited the smallest average austenite grain size of 240 {+-} 60 nm with an almost fully-austenitic structure.

  3. LUNAR DUST GRAIN CHARGING BY ELECTRON IMPACT: COMPLEX ROLE OF SECONDARY ELECTRON EMISSIONS IN SPACE ENVIRONMENTS

    SciTech Connect (OSTI)

    Abbas, M. M.; Craven, P. D.; LeClair, A. C.; Spann, J. F.; Tankosic, D.

    2010-08-01

    Dust grains in various astrophysical environments are generally charged electrostatically by photoelectric emissions with radiation from nearby sources, or by electron/ion collisions by sticking or secondary electron emissions (SEEs). The high vacuum environment on the lunar surface leads to some unusual physical and dynamical phenomena involving dust grains with high adhesive characteristics, and levitation and transportation over long distances. Knowledge of the dust grain charges and equilibrium potentials is important for understanding a variety of physical and dynamical processes in the interstellar medium, and heliospheric, interplanetary/planetary, and lunar environments. It has been well recognized that the charging properties of individual micron-/submicron-size dust grains are expected to be substantially different from the corresponding values for bulk materials. In this paper, we present experimental results on the charging of individual 0.2-13 {mu}m size dust grains selected from Apollo 11 and 17 dust samples, and spherical silica particles by exposing them to mono-energetic electron beams in the 10-200 eV energy range. The dust charging process by electron impact involving the SEEs discussed is found to be a complex charging phenomenon with strong particle size dependence. The measurements indicate substantial differences between the polarity and magnitude of the dust charging rates of individual small-size dust grains, and the measurements and model properties of corresponding bulk materials. A more comprehensive plan of measurements of the charging properties of individual dust grains for developing a database for realistic models of dust charging in astrophysical and lunar environments is in progress.

  4. Size-dependent structure of silver nanoparticles under high pressure

    SciTech Connect (OSTI)

    Koski, Kristie Jo

    2008-12-31

    Silver noble metal nanoparticles that are<10 nm often possess multiply twinned grains allowing them to adopt shapes and atomic structures not observed in bulk materials. The properties exhibited by particles with multiply twinned polycrystalline structures are often far different from those of single-crystalline particles and from the bulk. I will present experimental evidence that silver nanoparticles<10 nm undergo a reversible structural transformation under hydrostatic pressures up to 10 GPa. Results for nanoparticles in the intermediate size range of 5 to 10 nm suggest a reversible linear pressure-dependent rhombohedral distortion which has not been previously observed in bulk silver. I propose a mechanism for this transitiion that considers the bond-length distribution in idealized multiply twinned icosahedral particles. Results for nanoparticles of 3.9 nm suggest a reversible linear pressure-dependent orthorhombic distortion. This distortion is interpreted in the context of idealized decahedral particles. In addition, given these size-dependent measurements of silver nanoparticle compression with pressure, we have constructed a pressure calibration curve. Encapsulating these silver nanoparticles in hollow metal oxide nanospheres then allows us to measure the pressure inside a nanoshell using x-ray diffraction. We demonstrate the measurement of pressure gradients across nanoshells and show that these nanoshells have maximum resolved shear strengths on the order of 500 MPa to IGPa.

  5. Nucleation and Growth of Crystalline Grains in RF-Sputtered TiO2Films

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

    Johnson, J. C.; Ahrenkiel, S. P.; Dutta, P.; Bommisetty, V. R.

    2009-01-01

    AmorphousTiO2thin films were radio frequency sputtered onto siliconmonoxide and carbon support films on molybdenum transmission electron microscope (TEM) grids and observed during in situ annealing in a TEM heating stage at250?C. The evolution of crystallization is consistent with a classical model of homogeneous nucleation and isotropic grain growth. The two-dimensional grain morphology of the TEM foil allowed straightforward recognition of amorphous and crystallized regions of the films, for measurement of crystalline volume fraction and grain number density. By assuming that the kinetic parameters remain constant beyond the onset of crystallization, the final average grain size was computed, using an analyticalmoreextrapolation to the fully crystallized state. Electron diffraction reveals a predominance of the anatase crystallographic phase.less

  6. Nucleation and Growth of Crystalline Grains in RF-Sputtered TiO 2 Films

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

    Johnson, J. C.; Ahrenkiel, S. P.; Dutta, P.; Bommisetty, V. R.

    2009-01-01

    Amore » morphous TiO 2 thin films were radio frequency sputtered onto siliconmonoxide and carbon support films on molybdenum transmission electron microscope (TEM) grids and observed during in situ annealing in a TEM heating stage at 250 ∘ C. The evolution of crystallization is consistent with a classical model of homogeneous nucleation and isotropic grain growth. The two-dimensional grain morphology of the TEM foil allowed straightforward recognition of amorphous and crystallized regions of the films, for measurement of crystalline volume fraction and grain number density. By assuming that the kinetic parameters remain constant beyond the onset of crystallization, the final average grain size was computed, using an analytical extrapolation to the fully crystallized state. Electron diffraction reveals a predominance of the anatase crystallographic phase.« less

  7. Phloem Transport of Arsenic Species from Flag Leaf to Grain During Grain Filling

    SciTech Connect (OSTI)

    A Carey; G Norton; C Deacon; K Scheckel; E Lombi; T Punshon; M Guerinot; A Lanzirotti; M Newville; et al.

    2011-12-31

    Strategies to reduce arsenic (As) in rice grain, below concentrations that represent a serious human health concern, require that the mechanisms of As accumulation within grain be established. Therefore, retranslocation of As species from flag leaves into filling rice grain was investigated. Arsenic species were delivered through cut flag leaves during grain fill. Spatial unloading within grains was investigated using synchrotron X-ray fluorescence (SXRF) microtomography. Additionally, the effect of germanic acid (a silicic acid analog) on grain As accumulation in arsenite-treated panicles was examined. Dimethylarsinic acid (DMA) and monomethylarsonic acid (MMA) were extremely efficiently retranslocated from flag leaves to rice grain; arsenate was poorly retranslocated, and was rapidly reduced to arsenite within flag leaves; arsenite displayed no retranslocation. Within grains, DMA rapidly dispersed while MMA and inorganic As remained close to the entry point. Germanic acid addition did not affect grain As in arsenite-treated panicles. Three-dimensional SXRF microtomography gave further information on arsenite localization in the ovular vascular trace (OVT) of rice grains. These results demonstrate that inorganic As is poorly remobilized, while organic species are readily remobilized, from leaves to grain. Stem translocation of inorganic As may not rely solely on silicic acid transporters.

  8. Phloem transport of arsenic species from flag leaf to grain during grain filling

    SciTech Connect (OSTI)

    Carey, Anne-Marie; Norton, Gareth J.; Deacon, Claire; Scheckel, Kirk G.; Lombi, Enzo; Punshon, Tracy; Guerinot, Mary Lou; Lanzirotti, Antonio; Newville, Matt; Choi, Yongseong; Price, Adam H.; Meharg, Andrew A.

    2011-09-20

    Strategies to reduce arsenic (As) in rice grain, below concentrations that represent a serious human health concern, require that the mechanisms of As accumulation within grain be established. Therefore, retranslocation of As species from flag leaves into filling rice grain was investigated. Arsenic species were delivered through cut flag leaves during grain fill. Spatial unloading within grains was investigated using synchrotron X-ray fluorescence (SXRF) microtomography. Additionally, the effect of germanic acid (a silicic acid analog) on grain As accumulation in arsenite-treated panicles was examined. Dimethylarsinic acid (DMA) and monomethylarsonic acid (MMA) were extremely efficiently retranslocated from flag leaves to rice grain; arsenate was poorly retranslocated, and was rapidly reduced to arsenite within flag leaves; arsenite displayed no retranslocation. Within grains, DMA rapidly dispersed while MMA and inorganic As remained close to the entry point. Germanic acid addition did not affect grain As in arsenite-treated panicles. Three-dimensional SXRF microtomography gave further information on arsenite localization in the ovular vascular trace (OVT) of rice grains. These results demonstrate that inorganic As is poorly remobilized, while organic species are readily remobilized, from leaves to grain. Stem translocation of inorganic As may not rely solely on silicic acid transporters.

  9. Photoluminescence Imaging of Large-Grain CdTe for Grain Boundary Characterization

    SciTech Connect (OSTI)

    Johnston, Steve; Allende Motz, Alyssa; Reese, Matthew O.; Burst, James M.; Metzger, Wyatt K.

    2015-06-14

    In this work, we use photoluminescence (PL) imaging to characterize CdTe grain boundary recombination. We use a silicon megapixel camera and green (532 nm) laser diodes for excitation. A microscope objective lens system is used for high spatial resolution and a field of view down to 190 um x 190 um. PL images of large-grain (5 to 50 um) CdTe samples show grain boundary and grain interior features that vary with processing conditions. PL images of samples in the as-deposited state show distinct dark grain boundaries that suggest high excess carrier recombination. A CdCl2 treatment leads to PL images with very little distinction at the grain boundaries, which illustrates the grain boundary passivation properties. Other process conditions are also shown, along with comparisons of PL images to high spatial resolution time-resolved PL carrier lifetime maps.

  10. Grain refinement of permanent mold cast copper base alloys. Final report

    SciTech Connect (OSTI)

    Sadayappan, M.; Thomson, J. P.; Elboujdaini, M.; Gu, G. Ping; Sahoo, M.

    2004-04-29

    Grain refinement behavior of copper alloys cast in permanent molds was investigated. This is one of the least studied subjects in copper alloy castings. Grain refinement is not widely practiced for leaded copper alloys cast in sand molds. Aluminum bronzes and high strength yellow brasses, cast in sand and permanent molds, were usually fine grained due to the presence of more than 2% iron. Grain refinement of the most common permanent mold casting alloys, leaded yellow brass and its lead-free replacement EnviroBrass III, is not universally accepted due to the perceived problem of hard spots in finished castings and for the same reason these alloys contain very low amounts of iron. The yellow brasses and Cu-Si alloys are gaining popularity in North America due to their low lead content and amenability for permanent mold casting. These alloys are prone to hot tearing in permanent mold casting. Grain refinement is one of the solutions for reducing this problem. However, to use this technique it is necessary to understand the mechanism of grain refinement and other issues involved in the process. The following issues were studied during this three year project funded by the US Department of Energy and the copper casting industry: (1) Effect of alloying additions on the grain size of Cu-Zn alloys and their interaction with grain refiners; (2) Effect of two grain refining elements, boron and zirconium, on the grain size of four copper alloys, yellow brass, EnviroBrass II, silicon brass and silicon bronze and the duration of their effect (fading); (3) Prediction of grain refinement using cooling curve analysis and use of this method as an on-line quality control tool; (4) Hard spot formation in yellow brass and EnviroBrass due to grain refinement; (5) Corrosion resistance of the grain refined alloys; (6) Transfer the technology to permanent mold casting foundries; It was found that alloying elements such as tin and zinc do not change the grain size of Cu-Zn alloys

  11. Enhancing grain boundary ionic conductivity in mixed ionic–electronic conductors

    SciTech Connect (OSTI)

    Lin, Ye; Fang, Shumin; Su, Dong; Brinkman, Kyle S.; Chen, Fanglin

    2015-04-10

    Mixed ionic–electronic conductors are widely used in devices for energy conversion and storage. Grain boundaries in these materials have nanoscale spatial dimensions, which can generate substantial resistance to ionic transport due to dopant segregation. Here, we report the concept of targeted phase formation in a Ce0.8Gd0.2O2₋δ–CoFe2O4 composite that serves to enhance the grain boundary ionic conductivity. Using transmission electron microscopy and spectroscopy approaches, we probe the grain boundary charge distribution and chemical environments altered by the phase reaction between the two constituents. The formation of an emergent phase successfully avoids segregation of the Gd dopant and depletion of oxygen vacancies at the Ce0.8Gd0.2O2₋δ–Ce0.8Gd0.2O2₋δ grain boundary. This results in superior grain boundary ionic conductivity as demonstrated by the enhanced oxygen permeation flux. Lastly, this work illustrates the control of mesoscale level transport properties in mixed ionic–electronic conductor composites through processing induced modifications of the grain boundary defect distribution.

  12. Enhancing grain boundary ionic conductivity in mixed ionic–electronic conductors

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

    Lin, Ye; Fang, Shumin; Su, Dong; Brinkman, Kyle S.; Chen, Fanglin

    2015-04-10

    Mixed ionic–electronic conductors are widely used in devices for energy conversion and storage. Grain boundaries in these materials have nanoscale spatial dimensions, which can generate substantial resistance to ionic transport due to dopant segregation. Here, we report the concept of targeted phase formation in a Ce0.8Gd0.2O2₋δ–CoFe2O4 composite that serves to enhance the grain boundary ionic conductivity. Using transmission electron microscopy and spectroscopy approaches, we probe the grain boundary charge distribution and chemical environments altered by the phase reaction between the two constituents. The formation of an emergent phase successfully avoids segregation of the Gd dopant and depletion of oxygen vacanciesmore » at the Ce0.8Gd0.2O2₋δ–Ce0.8Gd0.2O2₋δ grain boundary. This results in superior grain boundary ionic conductivity as demonstrated by the enhanced oxygen permeation flux. Lastly, this work illustrates the control of mesoscale level transport properties in mixed ionic–electronic conductor composites through processing induced modifications of the grain boundary defect distribution.« less

  13. SIZE AND SURFACE AREA OF ICY DUST AGGREGATES AFTER A HEATING EVENT AT A PROTOPLANETARY NEBULA

    SciTech Connect (OSTI)

    Sirono, Sin-iti

    2013-03-01

    The activity of a young star rises abruptly during an FU Orionis outburst. This event causes a temporary temperature increase in the protoplanetary nebula. H{sub 2}O icy grains are sublimated by this event, and silicate cores embedded inside the ice are ejected. During the high-temperature phase, the silicate grains coagulate to form silicate core aggregates. After the heating event, the temperature drops, and the ice recondenses onto the aggregates. I determined numerically the size distribution of the ice-covered aggregates. The size of the aggregates exceeds 10 {mu}m around the snow line. Because of the migration of the ice to large aggregates, only a small fraction of the silicate core aggregate is covered with H{sub 2}O ice. After the heating event, the surface of an ice-covered aggregate is totally covered by silicate core aggregates. This might reduce the fragmentation velocity of aggregates when they collide. It is possible that the covering silicate cores shield the UV radiation field which induces photodissociation of H{sub 2}O ice. This effect may cause the shortage of cold H{sub 2}O vapor observed by Herschel.

  14. Grain refinement of cast zinc through magnesium inoculation: Characterisation and mechanism

    SciTech Connect (OSTI)

    Liu, Zhilin; Qiu, Dong; Wang, Feng; Taylor, John A.; Zhang, Mingxing

    2015-08-15

    It was previously found that peritectic-forming solutes are more favourable for the grain refinement of cast Al alloys than eutectic-forming solutes. In this work, we report that the eutectic-forming solute, Mg, can also significantly grain refine cast Zn. Differential thermal analysis (DTA) of a Zn–Mg alloy, in which efficient grain refinement occurred, evidenced an unexpected peak that appeared before the nucleation of η-Zn grains on the DTA spectrum. Based on extensive examination using X-ray diffraction, high resolution SEM and EDS, it was found that: (a) some faceted Zn–Mg intermetallic particles were reproducibly observed; (b) the particles were located at or near grain centres; (c) the atomic ratio of Mg to Zn in the intermetallic compound was determined to be around 1/2. Using tilting selected area diffraction (SAD) and convergent beam Kikuchi line diffraction pattern (CBKLDP) techniques, these faceted particles were identified as MgZn{sub 2} and an orientation relationship between such grain-centred MgZn{sub 2} particles and the η-Zn matrix was determined. Hence, the unexpected peak on the DTA spectrum is believed to correspond to the formation of MgZn{sub 2} particles, which act as effective heterogeneous nucleation sites in the alloy. Together with the effect of Mg solute on restricting grain growth, such heterogeneous nucleation is cooperatively responsible for the grain size reduction in Zn–Mg alloys. - Highlights: • A new eutectic-based grain refiner for the cast Zn was found. • The formation process of an intermetallic compound (MgZn{sub 2}) was characterised. • MgZn{sub 2} can act as potent heterogeneous nucleation sites above the liquidus. • A new OR between MgZn{sub 2} and η-Zn was determined using the CBKLDP technique.

  15. Northeast Missouri Grain LLC | Open Energy Information

    Open Energy Info (EERE)

    Missouri Grain LLC Place: Macon, Missouri Zip: 63552 Product: 36mmgy (136.3m litresy) ethanol producer. Coordinates: 35.153245, -89.491999 Show Map Loading map......

  16. United Wisconsin Grain Producers UWGP | Open Energy Information

    Open Energy Info (EERE)

    Name: United Wisconsin Grain Producers (UWGP) Place: Friesland, Wisconsin Product: Bioethanol producer using corn as feedstock References: United Wisconsin Grain Producers...

  17. Science at the interface : grain boundaries in nanocrystalline...

    Office of Scientific and Technical Information (OSTI)

    Science at the interface : grain boundaries in nanocrystalline metals. Citation Details In-Document Search Title: Science at the interface : grain boundaries in nanocrystalline ...

  18. Suppression of Grain Boundaries in Graphene Growth on Superstructured...

    Office of Scientific and Technical Information (OSTI)

    Suppression of Grain Boundaries in Graphene Growth on Superstructured Mn-Cu(111) Surface Title: Suppression of Grain Boundaries in Graphene Growth on Superstructured Mn-Cu(111) ...

  19. Grain orientation dependence of lattice strains and intergranular...

    Office of Scientific and Technical Information (OSTI)

    Grain orientation dependence of lattice strains and intergranular damage rates in polycrystals under cyclic loading Citation Details In-Document Search Title: Grain orientation ...

  20. The relationship between grain boundary structure, defect mobility, and grain boundary sink efficiency

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

    Uberuaga, Blas Pedro; Vernon, Louis J.; Martinez, Enrique; Voter, Arthur F.

    2015-03-13

    Nanocrystalline materials have received great attention due to their potential for improved functionality and have been proposed for extreme environments where the interfaces are expected to promote radiation tolerance. However, the precise role of the interfaces in modifying defect behavior is unclear. Using long-time simulations methods, we determine the mobility of defects and defect clusters at grain boundaries in Cu. We find that mobilities vary significantly with boundary structure and cluster size, with larger clusters exhibiting reduced mobility, and that interface sink efficiency depends on the kinetics of defects within the interface via the in-boundary annihilation rate of defects. Thus,more » sink efficiency is a strong function of defect mobility, which depends on boundary structure, a property that evolves with time. Further, defect mobility at boundaries can be slower than in the bulk, which has general implications for the properties of polycrystalline materials. Finally, we correlate defect energetics with the volumes of atomic sites at the boundary.« less

  1. SULFUR ISOTOPIC COMPOSITIONS OF SUBMICROMETER SiC GRAINS FROM THE MURCHISON METEORITE

    SciTech Connect (OSTI)

    Xu, Yuchen; Zinner, Ernst; Gallino, Roberto; Heger, Alexander; Pignatari, Marco; Lin, Yangting

    2015-02-01

    We report C, Si, N, S, Mg-Al, and Ca-Ti isotopic compositions of presolar silicon carbide (SiC) grains from the SiC-rich KJE size fraction (0.5-0.8 μm) of the Murchison meteorite. One thousand one hundred thirteen SiC grains were identified based on their C and Si isotopic ratios. Mainstream, AB, C, X, Y, and Z subtypes of SiC, and X-type silicon nitride (Si{sub 3}N{sub 4}) account for 81.4%, 5.7%, 0.1%, 1.5%, 5.8%, 4.9%, and 0.4%, respectively. Twenty-five grains with unusual Si isotopic ratios, including one C grain, 16 X grains, 1 Y grain, 5 Z grains, and 2 X-type Si{sub 3}N{sub 4} grains were selected for N, S, Mg-Al, and Ca-Ti isotopic analysis. The C grain is highly enriched in {sup 29}Si and {sup 30}Si (δ{sup 29}Si = 1345‰ ± 19‰, δ{sup 30}Si = 1272‰ ± 19‰). It has a huge {sup 32}S excess, larger than any seen before, and larger than that predicted for the Si/S supernova (SN) zone, providing evidence against the elemental fractionation model by Hoppe et al. Two SN models investigated here present a more satisfying explanation in terms of a radiogenic origin of {sup 32}S from the decay of short-lived {sup 32}Si (τ{sub 1/2} = 153 yr). Silicon-32 as well as {sup 29}Si and {sup 30}Si can be produced in SNe by short neutron bursts; evidence for initial {sup 44}Ti (τ{sub 1/2} = 60 yr) in the C grain is additional evidence for an SN origin. The X grains have marginal {sup 32}S excesses, much smaller than expected from their large {sup 28}Si excesses. Similarly, the Y and Z grains do not show the S-isotopic anomalies expected from their large Si isotopic anomalies. Low intrinsic S contents and contamination with isotopically normal S are the most likely explanations.

  2. Photoluminescence Imaging of Large-Grain CdTe for Grain Boundary...

    Office of Scientific and Technical Information (OSTI)

    Subject: 14 SOLAR ENERGY; 36 MATERIALS SCIENCE cadmium compounds; charge carrier lifetime; grain boundaries; imaging; photoluminescence; photovoltaic cells; tellurium Word Cloud ...

  3. Surface and grain boundary scattering in nanometric Cu thin films: A quantitative analysis including twin boundaries

    SciTech Connect (OSTI)

    Barmak, Katayun [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 and Department of Materials Science and Engineering and Materials Research Science and Engineering Center, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213 (United States); Darbal, Amith [Department of Materials Science and Engineering and Materials Research Science and Engineering Center, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213 (United States); Ganesh, Kameswaran J.; Ferreira, Paulo J. [Materials Science and Engineering, The University of Texas at Austin, 1 University Station, Austin, Texas 78712 (United States); Rickman, Jeffrey M. [Department of Materials Science and Engineering and Department of Physics, Lehigh University, Bethlehem, Pennsylvania 18015 (United States); Sun, Tik; Yao, Bo; Warren, Andrew P.; Coffey, Kevin R., E-mail: kb2612@columbia.edu [Department of Materials Science and Engineering, University of Central Florida, 4000 Central Florida Boulevard, Orlando, Florida 32816 (United States)

    2014-11-01

    The relative contributions of various defects to the measured resistivity in nanocrystalline Cu were investigated, including a quantitative account of twin-boundary scattering. It has been difficult to quantitatively assess the impact twin boundary scattering has on the classical size effect of electrical resistivity, due to limitations in characterizing twin boundaries in nanocrystalline Cu. In this study, crystal orientation maps of nanocrystalline Cu films were obtained via precession-assisted electron diffraction in the transmission electron microscope. These orientation images were used to characterize grain boundaries and to measure the average grain size of a microstructure, with and without considering twin boundaries. The results of these studies indicate that the contribution from grain-boundary scattering is the dominant factor (as compared to surface scattering) leading to enhanced resistivity. The resistivity data can be well-described by the combined FuchsSondheimer surface scattering model and MayadasShatzkes grain-boundary scattering model using Matthiessen's rule with a surface specularity coefficient of p?=?0.48 and a grain-boundary reflection coefficient of R?=?0.26.

  4. Hopper Job Size Charts

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

    Job Size Charts Hopper Job Size Charts Fractional Jobs The following charts show the fraction of hours used on Hopper in each of five job-core-size bins: 2014 Usage by Job Size Chart 2013 2012 2011 Large Jobs The following charts show the fraction of hours used on Hopper by jobs using greater than 16,384 cores: 2014 2013 2012 Usage by Job Size Chart 2011 Last edited: 2016-05-02 09:20:42

  5. Grain in weakly ionized plasma in the presence of an external magnetic field: Charging by plasma currents and effective potential

    SciTech Connect (OSTI)

    Momot, A. I.; M.M. Bogolubov Institute for Theoretical Physics, Nat. Acad. Sci. of Ukraine, 14b, Metrologichna Str., Kyiv, 03680

    2013-07-15

    The problem of grain screening is solved numerically for the case of weakly ionized plasma in the presence of an external magnetic field. The plasma dynamics is described within the drift-diffusion approximation under the assumption that the grain absorbs all encountered electrons and ions. We also assume that the plasma current through the grain surface is equal to zero in the stationary state. This condition is used to perform self-consistent calculations of the grain charge. The spatial distribution of the screened grain potential is studied and compared with the analytical estimates. It is shown that at the distances larger than the Debye length such potential has the Coulomb-like asymptotics with the effective charge dependent on the angle between the radius vector and the external magnetic field direction. The numerical solutions show that in the direction parallel to the external magnetic field the effective potential can have nonmonotonic behavior.

  6. Calculation of grain boundary normals directly from 3D microstructure images

    SciTech Connect (OSTI)

    Lieberman, E. J.; Rollett, A. D.; Lebensohn, R. A.; Kober, E. M.

    2015-03-11

    The determination of grain boundary normals is an integral part of the characterization of grain boundaries in polycrystalline materials. These normal vectors are difficult to quantify due to the discretized nature of available microstructure characterization techniques. The most common method to determine grain boundary normals is by generating a surface mesh from an image of the microstructure, but this process can be slow, and is subject to smoothing issues. A new technique is proposed, utilizing first order Cartesian moments of binary indicator functions, to determine grain boundary normals directly from a voxelized microstructure image. In order to validate the accuracy of this technique, the surface normals obtained by the proposed method are compared to those generated by a surface meshing algorithm. Specifically, the local divergence between the surface normals obtained by different variants of the proposed technique and those generated from a surface mesh of a synthetic microstructure constructed using a marching cubes algorithm followed by Laplacian smoothing is quantified. Next, surface normals obtained with the proposed method from a measured 3D microstructure image of a Ni polycrystal are used to generate grain boundary character distributions (GBCD) for Σ3 and Σ9 boundaries, and compared to the GBCD generated using a surface mesh obtained from the same image. Finally, the results show that the proposed technique is an efficient and accurate method to determine voxelized fields of grain boundary normals.

  7. Calculation of grain boundary normals directly from 3D microstructure images

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

    Lieberman, E. J.; Rollett, A. D.; Lebensohn, R. A.; Kober, E. M.

    2015-03-11

    The determination of grain boundary normals is an integral part of the characterization of grain boundaries in polycrystalline materials. These normal vectors are difficult to quantify due to the discretized nature of available microstructure characterization techniques. The most common method to determine grain boundary normals is by generating a surface mesh from an image of the microstructure, but this process can be slow, and is subject to smoothing issues. A new technique is proposed, utilizing first order Cartesian moments of binary indicator functions, to determine grain boundary normals directly from a voxelized microstructure image. In order to validate the accuracymore » of this technique, the surface normals obtained by the proposed method are compared to those generated by a surface meshing algorithm. Specifically, the local divergence between the surface normals obtained by different variants of the proposed technique and those generated from a surface mesh of a synthetic microstructure constructed using a marching cubes algorithm followed by Laplacian smoothing is quantified. Next, surface normals obtained with the proposed method from a measured 3D microstructure image of a Ni polycrystal are used to generate grain boundary character distributions (GBCD) for Σ3 and Σ9 boundaries, and compared to the GBCD generated using a surface mesh obtained from the same image. Finally, the results show that the proposed technique is an efficient and accurate method to determine voxelized fields of grain boundary normals.« less

  8. Edison Job Size Charts

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

    Reports » Edison Job Size Charts Edison Job Size Charts Fraction of Hours Used per Job Size Note: Interactive charts with current and past Cori and Edison data are now available on MyNERSC This chart shows the fraction of hours used on Edison in each of 5 job-core-size bins. 2015 Usage by Job Size Chart 2014 Fraction of Hours Used by Big Jobs This chart shows the fraction of hours used on Edison by jobs using 16,384 or more cores. 2015 Usage by Job Size Chart 2014 Last edited: 2016-04-21

  9. CASL - Effect of Grain Boundaries on Irradiation Growth of Zirconium-based

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

    Alloys Effect of Grain Boundaries on Irradiation Growth of Zirconium-based Alloys At the end of August, researchers S.I. Golubov, A.V. Barashev and R.E. Stoller delivered to CASL an analysis of the effect of grain size on the radiation growth of multigrain, hexagonal close-packed (hcp) metals, taking into account the features of cascade damage due to neutron exposure. Irradiation growth occurs in zirconium-based alloys used for LWR fuel cladding. Experimental data suggests that irradiation

  10. Microstructure and mechanical behavior of neutron irradiated ultrafine grained ferritic steel

    SciTech Connect (OSTI)

    Ahmad Alsabbagh; Apu Sarkar; Brandon Miller; Jatuporn Burns; Leah Squires; Douglas Porter; James I. Cole; K. L. Murty

    2014-10-01

    Neutron irradiation effects on ultra-fine grain (UFG) low carbon steel prepared by equal channel angular pressing (ECAP) has been examined. Counterpart samples with conventional grain (CG) sizes have been irradiated alongside with the UFG ones for comparison. Samples were irradiated in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL) to 1.24 dpa. Atom probe tomography revealed manganese, silicon-enriched clusters in both ECAP and CG steel after neutron irradiation. X-ray quantitative analysis showed that dislocation density in CG increased after irradiation. However, no significant change was observed in UFG steel revealing better radiation tolerance.

  11. Powder processing for the fabrication of Si{sub 3}N{sub 4} ceramics. 1: Influence of spray-dried granule strength on pore size distribution in green compacts

    SciTech Connect (OSTI)

    Kamiya, Hidehiro; Isomura, Kenji; Jimbo, Genji; Junichiro, Tsubaki

    1995-01-01

    The effect of spray-dried granule strength on the microstructure of green compacts obtained by isostatic pressing was quantitatively analyzed. The fracture strength of single granules of Si{sub 3}N{sub 4} powder made with ultrafine Al{sub 2}O{sub 3} and Y{sub 2}O{sub 3} powders was measured directly by diametral compression. It was found that fracture strength increased notably with the increasing relative density of the granule and the decreasing size of agglomerates in suspension before spray-drying. Even when green bodies were prepared at an isostatic pressure of 200 MPa, intergranular pores, which negatively affected densification of the sintered bodies, occurred between unfractured granules. The volume and size of these pores in the green compacts increased with the increasing fracture strength of the granules. In the case of closely packed granules, an isostatic pressure of 800 MPa was required to completely collapse the intergranular pores. A simple equation was derived to calculate the isostatic pressure necessary for complete collapse of intergranular pores in the green compacts, and it was determined that granule strength must be kept as low as possible to obtain uniform green compacts.

  12. Correlating Size and Composition-Dependent Effects with Magnetic...

    Office of Scientific and Technical Information (OSTI)

    Correlating Size and Composition-Dependent Effects with Magnetic, Mssbauer, and Pair Distribution Function Measurements in a Family of Catalytically Active Ferrite Nanoparticles ...

  13. Does the debris disk around HD 32297 contain cometary grains?

    SciTech Connect (OSTI)

    Rodigas, Timothy J.; Hinz, Philip M.; Bailey, Vanessa; Defrere, Denis; Leisenring, Jarron; Schneider, Glenn; Skemer, Andrew J.; Vaitheeswaran, Vidhya; Debes, John H.; Mamajek, Eric E.; Pecaut, Mark J.; Currie, Thayne; De Rosa, Robert J.; Ward-Duong, Kimberly; Hill, John M.; Skrutskie, Michael

    2014-03-01

    We present an adaptive optics imaging detection of the HD 32297 debris disk at L' (3.8 ?m) obtained with the LBTI/LMIRcam infrared instrument at the Large Binocular Telescope. The disk is detected at signal-to-noise ratio per resolution element ?3-7.5 from ?0.''3 to 1.''1 (30-120 AU). The disk at L' is bowed, as was seen at shorter wavelengths. This likely indicates that the disk is not perfectly edge-on and contains highly forward-scattering grains. Interior to ?50 AU, the surface brightness at L' rises sharply on both sides of the disk, which was also previously seen at Ks band. This evidence together points to the disk containing a second inner component located at ?50 AU. Comparing the color of the outer (50 grains model of Donaldson et al. We find that the model fails to match this disk's surface brightness and spectrum simultaneously (reduced chi-square = 17.9). When we modify the density distribution of the model disk, we obtain a better overall fit (reduced chi-square = 2.87). The best fit to all of the data is a pure water ice model (reduced chi-square = 1.06), but additional resolved imaging at 3.1 ?m is necessary to constrain how much (if any) water ice exists in the disk, which can then help refine the originally proposed cometary grains model.

  14. Large grain cavities from pure niobium ingot

    DOE Patents [OSTI]

    Myneni, Ganapati Rao; Kneisel, Peter; Cameiro, Tadeu

    2012-03-06

    Niobium cavities are fabricated by the drawing and ironing of as cast niobium ingot slices rather than from cold rolled niobium sheet. This method results in the production of niobium cavities having a minimum of grain boundaries at a significantly reduced cost as compared to the production of such structures from cold rolled sheet.

  15. 4-D XRD for strain in many grains using triangulation

    SciTech Connect (OSTI)

    Bale, Hrishikesh A.; Hanan, Jay C.; Tamura, Nobumichi

    2006-12-31

    Determination of the strains in a polycrystalline materialusing 4-D XRD reveals sub-grain and grain-to-grain behavior as a functionof stress. Here 4-D XRD involves an experimental procedure usingpolychromatic micro-beam X-radiation (micro-Laue) to characterizepolycrystalline materials in spatial location as well as with increasingstress. The in-situ tensile loading experiment measured strain in a modelaluminum-sapphire metal matrix composite using the Advanced Light Source,Beam-line 7.3.3. Micro-Laue resolves individual grains in thepolycrystalline matrix. Results obtained from a list of grains sorted bycrystallographic orientation depict the strain states within and amongindividual grains. Locating the grain positions in the planeperpendicular to the incident beam is trivial. However, determining theexact location of grains within a 3-D space is challenging. Determiningthe depth of the grains within the matrix (along the beam direction)involved a triangulation method tracing individual rays that producespots on the CCD back to the point of origin. Triangulation wasexperimentally implemented by simulating a 3-D detector capturingmultiple diffraction images while increasing the camera to sampledistance. Hence by observing the intersection of rays from multiple spotsbelonging to the corresponding grain, depth is calculated. Depthresolution is a function of the number of images collected, grain to beamsize ratio, and the pixel resolution of the CCD. The 4DXRD methodprovides grain morphologies, strain behavior of each grain, andinteractions of the matrix grains with each other and the centrallylocated single crystal fiber.

  16. Synchrotron characterization of nanograined UO2 grain growth

    SciTech Connect (OSTI)

    Mo, Kun; Miao, Yinbin; Yun, Di; Jamison, Laura M.; Lian, Jie; Yao, Tiankei

    2015-09-30

    This activity is supported by the US Nuclear Energy Advanced Modeling and Simulation (NEAMS) Fuels Product Line (FPL) and aims at providing experimental data for the validation of the mesoscale simulation code MARMOT. MARMOT is a mesoscale multiphysics code that predicts the coevolution of microstructure and properties within reactor fuel during its lifetime in the reactor. It is an important component of the Moose-Bison-Marmot (MBM) code suite that has been developed by Idaho National Laboratory (INL) to enable next generation fuel performance modeling capability as part of the NEAMS Program FPL. In order to ensure the accuracy of the microstructure based materials models being developed within the MARMOT code, extensive validation efforts must be carried out. In this report, we summarize our preliminary synchrotron radiation experiments at APS to determine the grain size of nanograin UO2. The methodology and experimental setup developed in this experiment can directly apply to the proposed in-situ grain growth measurements. The investigation of the grain growth kinetics was conducted based on isothermal annealing and grain growth characterization as functions of duration and temperature. The kinetic parameters such as activation energy for grain growth for UO2 with different stoichiometry are obtained and compared with molecular dynamics (MD) simulations.

  17. Re-examination of laminated osagid grains from a Lower Permian midcontinent limestone

    SciTech Connect (OSTI)

    Toomey, D.F. ); Lowenstein, T.K. ); Mitchell, R.W. )

    1989-02-01

    Osagid grains from the Lower Permian (Wolfcamp) Winfield Limestone of southern Kansas-northern Oklahoma are small accretionary structures formed in shallow, well-agitated waters on a carbonate shelf. Osagid grains consist of small shell fragments serving as nuclei, which during formation were rolled about and coated by roughly concentric algal-foraminiferal laminations. Their shapes range from round to subround to elliptical, dependent primarily on the size and shape of the shell nuclei. Grain laminae are dark micrite which in places contain tubules of the blue-green alga Girvanella, and/or various encrusting foraminifers, with either calcareous or agglutinated tests, or intermixtures of all three components. Formic acid etching of individual osagid grains indicates that the agglutinated foraminiferal component is of greater importance than previously believed and can be their principal biotic component. Girvanella tubules appear to be most susceptible to diagenetic alteration, with the end-product generally a dark, micritic groundmass of algal dust. Since these accretionary structures are not true biological species, the generic term Osagia should be dropped and these structures should be called osgid grains.

  18. In-situ single-grain peak profile measurements on Ti-7Al during tensile deformation.

    SciTech Connect (OSTI)

    Lienert, U.; Brandes, M. C.; Bernier, J. V.; Weiss, J.; Shastri, S. D.; Mills, M. J.; Miller, M. P.; US Naval Research Lab.; LLNL; Mechanical Solutions, Inc.; Ohio State Univ.; Cornell Univ.

    2009-10-25

    High-energy three-dimensional X-ray diffraction with medium and high reciprocal space resolution was applied to study in situ tensile deformation of Ti-7Al specimens. Samples with planar and random dislocation microstructures were prepared and characterized by electron microscopy. Stress tensors of individual grains were obtained at several loads up to 2% deformation. The stress tensors were found to rotate, and resolved shear stresses were calculated. High-resolution reciprocal space maps of selected grains were recorded. Azimuthal and radial distributions were visualized and discussed in terms of idealized dislocation structures. Heterogeneous grain rotations were observed for the planar microstructure and found to be consistent with activation of the highest stressed basal slip system. Intra-granular strain gradients were detected in excess of the intrinsic radial dislocation peak broadening. The potential of combining the applied techniques with modeling to obtain multiple length-scale information during deformation of bulk specimens is discussed.

  19. ARM - Measurement - Hydrometeor size

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

    size ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Hydrometeor size The size of a hydrometeor, measured directly or derived from other measurements. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those

  20. Effect of Grain Refinement on the Mechanical Behaviour of an Al6061 Alloy at Cryogenic Temperatures

    SciTech Connect (OSTI)

    Moreno-Valle, E.; Sabirov, I.; Murashkin, M. Yu.; Valiev, R. Z.; Bobruk, E. V.; Perez-Prado, M. T.

    2011-05-04

    A solution treated coarse grained (CG) Al6061 was subjected to high pressure torsion (HPT) at room temperature resulting in the formation of a homogeneous ultra-fine grained (UFG) microstructure with an average grain size of 170 nm. Tensile tests were performed at room temperature (RT) and liquid nitrogen temperature (LNT). The as-HPT UFG Al6061 alloy shows an increased strength at both RT and LNT. The decrease of testing temperature results in increased flow stress and in enhanced elongation to failure in both CG and UFG samples. The ratio {sigma}{sub y}{sup LNT}/{sigma}{sub y}{sup RT} was found to be larger for the CG Al6061 than for the UFG Al6061. Both surface relief and fracture surface observations were performed. The effect of the grain size and of the testing temperature on the mechanical behaviour of the Al6061 alloy is analyzed in detail. It is suggested that the solute atoms play an important role in the plastic deformation of the UFG Al6061 alloy.

  1. Non-wetting surface-driven high-aspect-ratio crystalline grain growth for efficient hybrid perovskite solar cells

    SciTech Connect (OSTI)

    Bi, Cheng; Wang, Qi; Shao, Yuchuan; Yuan, Yongbo; Xiao, Zhengguo; Huang, Jinsong

    2015-07-20

    Large-aspect-ratio grains are needed in polycrystalline thin-film solar cells for reduced charge recombination at grain boundaries; however, the grain size in organolead trihalide perovskite (OTP) films is generally limited by the film thickness. Here we report the growth of OTP grains with high average aspect ratio of 2.3–7.9 on a wide range of non-wetting hole transport layers (HTLs), which increase nucleus spacing by suppressing heterogeneous nucleation and facilitate grain boundary migration in grain growth by imposing less drag force. The reduced grain boundary area and improved crystallinity dramatically reduce the charge recombination in OTP thin films to the level in OTP single crystals. Combining the high work function of several HTLs, a high stabilized device efficiency of 18.3% in low-temperature-processed planar-heterojunction OTP devices under 1 sun illumination is achieved. As a result, this simple method in enhancing OTP morphology paves the way for its application in other optoelectronic devices for enhanced performance.

  2. Non-wetting surface-driven high-aspect-ratio crystalline grain growth for efficient hybrid perovskite solar cells

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

    Bi, Cheng; Wang, Qi; Shao, Yuchuan; Yuan, Yongbo; Xiao, Zhengguo; Huang, Jinsong

    2015-07-20

    Large-aspect-ratio grains are needed in polycrystalline thin-film solar cells for reduced charge recombination at grain boundaries; however, the grain size in organolead trihalide perovskite (OTP) films is generally limited by the film thickness. Here we report the growth of OTP grains with high average aspect ratio of 2.3–7.9 on a wide range of non-wetting hole transport layers (HTLs), which increase nucleus spacing by suppressing heterogeneous nucleation and facilitate grain boundary migration in grain growth by imposing less drag force. The reduced grain boundary area and improved crystallinity dramatically reduce the charge recombination in OTP thin films to the level inmore » OTP single crystals. Combining the high work function of several HTLs, a high stabilized device efficiency of 18.3% in low-temperature-processed planar-heterojunction OTP devices under 1 sun illumination is achieved. As a result, this simple method in enhancing OTP morphology paves the way for its application in other optoelectronic devices for enhanced performance.« less

  3. Strengthening of metallic alloys with nanometer-size oxide dispersions

    DOE Patents [OSTI]

    Flinn, J.E.; Kelly, T.F.

    1999-06-01

    Austenitic stainless steels and nickel-base alloys containing, by wt. %, 0.1 to 3.0% V, 0.01 to 0.08% C, 0.01 to 0.5% N, 0.05% max. each of Al and Ti, and 0.005 to 0.10% O, are strengthened and ductility retained by atomization of a metal melt under cover of an inert gas with added oxygen to form approximately 8 nanometer-size hollow oxides within the alloy grains and, when the alloy is aged, strengthened by precipitation of carbides and nitrides nucleated by the hollow oxides. Added strengthening is achieved by nitrogen solid solution strengthening and by the effect of solid oxides precipitated along and pinning grain boundaries to provide temperature-stabilization and refinement of the alloy grains. 20 figs.

  4. Strengthening of metallic alloys with nanometer-size oxide dispersions

    DOE Patents [OSTI]

    Flinn, John E. (Idaho Falls, ID); Kelly, Thomas F. (Madison, WI)

    1999-01-01

    Austenitic stainless steels and nickel-base alloys containing, by wt. %, 0.1 to 3.0% V, 0.01 to 0.08% C, 0.01 to 0.5% N, 0.05% max. each of Al and Ti, and 0.005 to 0.10% O, are strengthened and ductility retained by atomization of a metal melt under cover of an inert gas with added oxygen to form approximately 8 nanometer-size hollow oxides within the alloy grains and, when the alloy is aged, strengthened by precipitation of carbides and nitrides nucleated by the hollow oxides. Added strengthening is achieved by nitrogen solid solution strengthening and by the effect of solid oxides precipitated along and pinning grain boundaries to provide temperature-stabilization and refinement of the alloy grains.

  5. Multiscale model of metal alloy oxidation at grain boundaries

    SciTech Connect (OSTI)

    Sushko, Maria L. Alexandrov, Vitaly; Schreiber, Daniel K.; Rosso, Kevin M.; Bruemmer, Stephen M.

    2015-06-07

    High temperature intergranular oxidation and corrosion of metal alloys is one of the primary causes of materials degradation in nuclear systems. In order to gain insights into grain boundary oxidation processes, a mesoscale metal alloy oxidation model is established by combining quantum Density Functional Theory (DFT) and mesoscopic Poisson-Nernst-Planck/classical DFT with predictions focused on Ni alloyed with either Cr or Al. Analysis of species and fluxes at steady-state conditions indicates that the oxidation process involves vacancy-mediated transport of Ni and the minor alloying element to the oxidation front and the formation of stable metal oxides. The simulations further demonstrate that the mechanism of oxidation for Ni-5Cr and Ni-4Al is qualitatively different. Intergranular oxidation of Ni-5Cr involves the selective oxidation of the minor element and not matrix Ni, due to slower diffusion of Ni relative to Cr in the alloy and due to the significantly smaller energy gain upon the formation of nickel oxide compared to that of Cr{sub 2}O{sub 3}. This essentially one-component oxidation process results in continuous oxide formation and a monotonic Cr vacancy distribution ahead of the oxidation front, peaking at alloy/oxide interface. In contrast, Ni and Al are both oxidized in Ni-4Al forming a mixed spinel NiAl{sub 2}O{sub 4}. Different diffusivities of Ni and Al give rise to a complex elemental distribution in the vicinity of the oxidation front. Slower diffusing Ni accumulates in the oxide and metal within 3 nm of the interface, while Al penetrates deeper into the oxide phase. Ni and Al are both depleted from the region 3–10 nm ahead of the oxidation front creating voids. The oxide microstructure is also different. Cr{sub 2}O{sub 3} has a plate-like structure with 1.2–1.7 nm wide pores running along the grain boundary, while NiAl{sub 2}O{sub 4} has 1.5 nm wide pores in the direction parallel to the grain boundary and 0.6 nm pores in the perpendicular

  6. EIS Distribution

    Broader source: Energy.gov [DOE]

    This DOE guidance presents a series of recommendations related to the EIS distribution process, which includes creating and updating a distribution list, distributing an EIS, and filing an EIS with the EPA.

  7. Synthesis of fine-grained TATB

    DOE Patents [OSTI]

    Lee, Kien-Yin; Kennedy, James E.

    2003-04-15

    A method for producing fine-grained triamino-trinitrobenzene (TATB) powders having improved detonation-spreading performance and hence increased shock sensitivity when compared with that for ultrafine TATB is described. A single-step, sonochemical amination of trichloro-trinitrobenzene using ammonium hydroxide solution in a sealed vessel yields TATB having approximately 6 .mu.m median particle diameter and increased shock sensitivity.

  8. Square Grains in Asymmetric Rod-Coil Block Copolymers (Journal...

    Office of Scientific and Technical Information (OSTI)

    Unlike the rounded grains that are well known to form in most soft materials, square grains of microphase-separated lamellae are observed in thin films of a rod-coil block ...

  9. Advanced Biorefinery of Distriller's Grain and Corn Stover Blends

    SciTech Connect (OSTI)

    2006-04-01

    Fuel ethanol can be produced via the dry milling process, which converts corn grain to ethanol. The co-product, distiller’s grain (DG), is sold as a low-cost, high-protein feed source for livestock.

  10. Grain Growth Behavior, Tensile Impact Ductility, and Weldability of Cerium-Doped Iridium Alloys

    SciTech Connect (OSTI)

    McKamey, C.G.

    2002-05-28

    An iridium alloy doped with small amounts of cerium and thorium is being developed as a potential replacement for the iridium-based DOP-26 alloy (doped with thorium only) that is currently used by the National Aeronautics and Space Administration (NASA) for cladding and post-impact containment of the radioactive fuel in radioisotope thermoelectric generator (RTG) heat sources which provide electric power for interplanetary spacecraft. This report summarizes results of studies conducted to date under the Iridium Alloy Characterization and Development subtask of the Radioisotope Power System Materials Production and Technology Program to characterize the properties of the iridium-based alloy (designated as DOP-40) containing both cerium and thorium. Included within this report are data on grain growth of sheet material in vacuum and low-pressure oxygen environments, grain growth in vacuum of the clad vent set cup material, weldability, and the effect of grain size and test temperature on tensile properties. Where applicable, data for the DOP-26 alloy are included for comparison. Both grain size and grain-boundary cohesion affect the ductility of iridium alloys. In this study it was found that cerium and thorium, when added together, refine grain size more effectively than when thorium is added by itself (especially at high temperatures). In addition, the effect of cerium additions on grain-boundary cohesion is similar to that of thorium. Mechanical testing at both low ({approx} 10{sup -3}s{sup -1}) and high ({approx} 10{sup -3}s{sup -1}) strain rates showed that the Ce/Th-doped alloys have tensile ductilities that are as good or better than the DOP-26 alloy. The general conclusion from these studies is that cerium can be used to replace some of the radioactive thorium currently used in DOP-26 while maintaining or improving its metallurgical properties. The current DOP-26 alloy meets all requirements for cladding the radioactive fuel in the RTG heat source, but the

  11. Equal Channel Angular Pressing (ECAP) and Its Application to Grain Refinement of Al-Zn-Mg-Cu Alloy

    SciTech Connect (OSTI)

    Tekeli, Sueleyman; Gueral, Ahmet

    2011-12-10

    Microstructure of a metal can be considerably changed by severe plastic deformation techniques such as high pressure torsion, extrusion and equal-channel angular pressing (ECAP). Among these methods, ECAP is particularly attractive because it has a potential for introducing significant grain refinement and homogeneous microstructure into bulk materials. Typically, it reduces the grain size to the submicrometer level or even nanometer range and thus produces materials that are capable of exhibiting unusual mechanical properties. In the present study, a test unites for equal channel angular pressing was constructed and this system was used for Al-Zn-Mg-Cu alloy. After the optimization tests, it was seen that the most effective lubricant for the dies was MoS{sub 2}, the pressing pressure was around 25-35 ton and the pressing speed was 2 mm/s. By using these parameters, the Al-Zn-Mg-Cu alloy was successfully ECAPed up to 14 passes at 200 deg. C using route C. After ECAP tests, the specimens were characterized by transmission electron microscope (TEM), hardness and macrostructural investigations. It was seen that the plastic deformation in the ECAPed specimens occurred from edge to the centre like whirlpool. In addition, the deformation intensity increased with increasing pass number. The grain size of the specimens effectively also decreased with increasing pass number. That is, while the grain size of unECAPed specimen was 10 {mu}m, this value decreased to 300 nm after 14 passes. At the beginning, while there was a banding tendency in the grains toward deformation direction, homogeneous and equiaxed grains were formed with increasing pass number. This grain refinement was as a result of an interaction between shear strain and thermal recovery during ECAP processing. Hardness measurements showed that the hardness values increased up to 4 passes, decreased effectively at 6th pass, again increased at 8th pass and after this pass, the hardness again decreased due to

  12. Evolution of Grain Boundary Networks in Extreme Radiation Environments

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

    of the Evolution of Grain Boundary Networks in Extreme Radiation Environments. Evolution of Grain Boundary Networks in Extreme Radiation Environments Research Our objective is to understand the characteristics of an "optimal" grain boundary (GB) network that minimizes microstructural evolution in radiation environments. Through our research we have elucidated that this optimal network requires a balance between two populations of grain boundaries: low free volume (low free energy)

  13. Nano/ultrafine grained austenitic stainless steel through the formation and reversion of deformation-induced martensite: Mechanisms, microstructures, mechanical properties, and TRIP effect

    SciTech Connect (OSTI)

    Shirdel, M.; Mirzadeh, H.; Parsa, M.H.

    2015-05-15

    A comprehensive study was carried out on the strain-induced martensitic transformation, its reversion to austenite, the resultant grain refinement, and the enhancement of strength and strain-hardening ability through the transformation-induced plasticity (TRIP) effect in a commercial austenitic 304L stainless steel with emphasis on the mechanisms and the microstructural evolution. A straightforward magnetic measurement device, which is based on the measurement of the saturation magnetization, for evaluating the amount of strain-induced martensite after cold rolling and reversion annealing in metastable austenitic stainless steels was used, which its results were in good consistency with those of the X-ray diffraction (XRD) method. A new parameter called the effective reduction in thickness was introduced, which corresponds to the reasonable upper bound on the obtainable martensite fraction based on the saturation in the martensitic transformation. By means of thermodynamics calculations, the reversion mechanisms were estimated and subsequently validated by experimental results. The signs of thermal martensitic transformation at cooling stage after reversion at 850 °C were found, which was attributed to the rise in the martensite start temperature due to the carbide precipitation. After the reversion treatment, the average grain sizes were around 500 nm and the nanometric grains of the size of ~ 65 nm were also detected. The intense grain refinement led to the enhanced mechanical properties and observation of the change in the work-hardening capacity and TRIP effect behavior. A practical map as a guidance for grain refining and characterizing the stability against grain growth was proposed, which shows the limitation of the reversion mechanism for refinement of grain size. - Graphical abstract: Display Omitted - Highlights: • Nano/ultrafine grained austenitic stainless steel through martensite treatment • A parameter descriptive of a reasonable upper bound on

  14. Coarse-grained simulations of polyelectrolyte complexes: MARTINI models for poly(styrene sulfonate) and poly(diallyldimethylammonium)

    SciTech Connect (OSTI)

    Vögele, Martin; Holm, Christian; Smiatek, Jens

    2015-12-28

    We present simulations of aqueous polyelectrolyte complexes with new MARTINI models for the charged polymers poly(styrene sulfonate) and poly(diallyldimethylammonium). Our coarse-grained polyelectrolyte models allow us to study large length and long time scales with regard to chemical details and thermodynamic properties. The results are compared to the outcomes of previous atomistic molecular dynamics simulations and verify that electrostatic properties are reproduced by our MARTINI coarse-grained approach with reasonable accuracy. Structural similarity between the atomistic and the coarse-grained results is indicated by a comparison between the pair radial distribution functions and the cumulative number of surrounding particles. Our coarse-grained models are able to quantitatively reproduce previous findings like the correct charge compensation mechanism and a reduced dielectric constant of water. These results can be interpreted as the underlying reason for the stability of polyelectrolyte multilayers and complexes and validate the robustness of the proposed models.

  15. Does size matter?

    SciTech Connect (OSTI)

    Carreras, B. A.; Physics Department, College of Natural Science and Mathematics and Geophysical Institute, University of Alaska, Fairbanks, Alaska 99775; Physics Department, Universidad Carlos III de Madrid, Madrid ; Newman, D. E.; Dobson, Ian

    2014-06-15

    Failures of the complex infrastructures society depends on having enormous human and economic cost that poses the question: Are there ways to optimize these systems to reduce the risks of failure? A dynamic model of one such system, the power transmission grid, is used to investigate the risk from failure as a function of the system size. It is found that there appears to be optimal sizes for such networks where the risk of failure is balanced by the benefit given by the size.

  16. Strategy Guideline: HVAC Equipment Sizing

    SciTech Connect (OSTI)

    Burdick, A.

    2012-02-01

    The heating, ventilation, and air conditioning (HVAC) system is arguably the most complex system installed in a house and is a substantial component of the total house energy use. A right-sized HVAC system will provide the desired occupant comfort and will run efficiently. This Strategy Guideline discusses the information needed to initially select the equipment for a properly designed HVAC system. Right-sizing of an HVAC system involves the selection of equipment and the design of the air distribution system to meet the accurate predicted heating and cooling loads of the house. Right-sizing the HVAC system begins with an accurate understanding of the heating and cooling loads on a space; however, a full HVAC design involves more than just the load estimate calculation - the load calculation is the first step of the iterative HVAC design procedure. This guide describes the equipment selection of a split system air conditioner and furnace for an example house in Chicago, IL as well as a heat pump system for an example house in Orlando, Florida. The required heating and cooling load information for the two example houses was developed in the Department of Energy Building America Strategy Guideline: Accurate Heating and Cooling Load Calculations.

  17. WINDExchange: Distributed Wind

    Wind Powering America (EERE)

    Distributed Wind Photo of a small wind turbine next to a farm house with a colorful sunset in the background. The distributed wind market includes wind turbines and projects of many sizes, from small wind turbines less than 1 kilowatt (kW) to multi-megawatt wind farms. The term "distributed wind" describes off-grid or grid-connected wind turbines at homes, farms and ranches, businesses, public and industrial facilities, and other sites. The turbines can provide all of the power used at

  18. Systematic and simulation-free coarse graining of homopolymer melts: A structure-based study

    SciTech Connect (OSTI)

    Yang, Delian; Wang, Qiang

    2015-02-07

    We propose a systematic and simulation-free strategy for coarse graining of homopolymer melts, where each chain of N{sub m} monomers is uniformly divided into N segments, with the spatial position of each segment corresponding to the center-of-mass of its monomers. We use integral-equation theories suitable for the study of equilibrium properties of polymers, instead of many-chain molecular simulations, to obtain the structural and thermodynamic properties of both original and coarse-grained (CG) systems, and quantitatively examine how the effective pair potentials between CG segments and the thermodynamic properties of CG systems vary with N. Our systematic and simulation-free strategy is much faster than those using many-chain simulations, thus effectively solving the transferability problem in coarse graining, and provides the quantitative basis for choosing the appropriate N-values. It also avoids the problems caused by finite-size effects and statistical uncertainties in many-chain simulations. Taking the simple hard-core Gaussian thread model [K. S. Schweizer and J. G. Curro, Chem. Phys. 149, 105 (1990)] as the original system, we demonstrate our strategy applied to structure-based coarse graining, which is quite general and versatile, and compare in detail the various integral-equation theories and closures for coarse graining. Our numerical results show that the effective CG potentials for various N and closures can be collapsed approximately onto the same curve, and that structure-based coarse graining cannot give thermodynamic consistency between original and CG systems at any N < N{sub m}.

  19. Atomistic simulations of dislocation pileup: Grain boundaries interaction

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

    Wang, Jian

    2015-05-27

    Here, using molecular dynamics (MD) simulations, we studied the dislocation pileup–grain boundary (GB) interactions. Two Σ11 asymmetrical tilt grain boundaries in Al are studied to explore the influence of orientation relationship and interface structure on dislocation activities at grain boundaries. To mimic the reality of a dislocation pileup in a coarse-grained polycrystalline, we optimized the dislocation population in MD simulations and developed a predict-correct method to create a dislocation pileup in MD simulations. MD simulations explored several kinetic processes of dislocations–GB reactions: grain boundary sliding, grain boundary migration, slip transmission, dislocation reflection, reconstruction of grain boundary, and the correlation ofmore » these kinetic processes with the available slip systems across the GB and atomic structures of the GB.« less

  20. Atomistic simulations of dislocation pileup: Grain boundaries interaction

    SciTech Connect (OSTI)

    Wang, Jian

    2015-05-27

    Here, using molecular dynamics (MD) simulations, we studied the dislocation pileup–grain boundary (GB) interactions. Two Σ11 asymmetrical tilt grain boundaries in Al are studied to explore the influence of orientation relationship and interface structure on dislocation activities at grain boundaries. To mimic the reality of a dislocation pileup in a coarse-grained polycrystalline, we optimized the dislocation population in MD simulations and developed a predict-correct method to create a dislocation pileup in MD simulations. MD simulations explored several kinetic processes of dislocations–GB reactions: grain boundary sliding, grain boundary migration, slip transmission, dislocation reflection, reconstruction of grain boundary, and the correlation of these kinetic processes with the available slip systems across the GB and atomic structures of the GB.

  1. GRAIN BOUNDARY STRENGTHENING PROPERTIES OF TUNGSTEN ALLOYS

    SciTech Connect (OSTI)

    Setyawan, Wahyu; Kurtz, Richard J.

    2012-10-10

    Density functional theory was employed to investigate grain boundary (GB) properties of W alloys. A range of substitutional solutes across the Periodic Table was investigated to understand the behavior of different electronic orbitals in changing the GB cleavage energy in the Σ27a[110]{525} GB. A number of transition metals were predicted to enhance the GB cohesion. This includes Ru, Re, Os, Ir, V, Cr, Mn, Fe, Co, Ti, Hf, Ta and Nb. While lanthanides, s and p elements were tended to cause GB embrittlement.

  2. Hot-isostatic pressing of U-10Zr by grain boundary diffusion and creep cavitation. Part 2: Theory and data analysis

    SciTech Connect (OSTI)

    McDeavitt, S.M.; Solomon, A.A.

    1997-08-01

    Uranium-10 wt % zirconium (U-10Zr) is a fuel alloy that has been used in the Experimental Breeder Reactor-II (EBR-II). The high burnup that was desired in this fuel system made high demands on the mechanical compatibility between fuel and cladding both during normal operation and during safety-related transients when rapid differential expansion may cause high stresses. In general, this mechanical stress can be reduced by cladding deformation if the cladding is sufficiently ductile at high burnup, and/or by fuel hot-pressing. Fortunately, the fuel is very porous when it contacts the cladding, but this porosity gradually fills with solid fission products (primarily lanthanides) that may limit the fuel`s compressibility. If the porosity remains open, gaseous fission products are released and the porous fuel creeps rather than hot-presses under contact stresses. If the pores are closed by sintering or by solid fission products, the porous fuel will hot-isostatic press (HIP), as represented by the models to be discussed. HIP experiments performed at 700 C on U-10Zr samples with different impurity phase contents (Part 1) are analyzed in terms of several creep cavitation models. The coupled diffusion/creep cavitation model of Chen and Argon shows good quantitative agreement with measured HIP rates for hydride- and metal-derived U-10Zr materials, assuming that pores are uniformly distributed on grain boundaries and are of modal size, and that far-field strain rates are negligible. The analysis predicts, for the first time, an asymmetry between HIP and swelling at identical pressure-induced driving forces due to differences in grain boundary stresses. The differences in compressibility of hydride- and metal-derived U-10Zr can be partially explained by differences in pore size and spacing. The relevance of the experiments to description of in-reactor densification under external pressure or contact stress due to fuel/cladding mechanical interaction is discussed.

  3. Distributed PV Interconnection: Recent Analysis Findings

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

    Make Smart Solar Decisions Distributed Solar Interconnection: Challenges and Best ... 50, Arizona: 54, Colorado: 63, New York: 68 New Jersey: 90 System Size Mean Median Std. ...

  4. Order parameter re-mapping algorithm for 3D phase field model of grain growth using FEM

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

    Permann, Cody J.; Tonks, Michael R.; Fromm, Bradley; Gaston, Derek R.

    2016-01-14

    Phase field modeling (PFM) is a well-known technique for simulating microstructural evolution. To model grain growth using PFM, typically each grain is assigned a unique non-conserved order parameter and each order parameter field is evolved in time. Traditional approaches using a one-to-one mapping of grains to order parameters present a challenge when modeling large numbers of grains due to the computational expense of using many order parameters. This problem is exacerbated when using an implicit finite element method (FEM), as the global matrix size is proportional to the number of order parameters. While previous work has developed methods to reducemore » the number of required variables and thus computational complexity and run time, none of the existing approaches can be applied for an implicit FEM implementation of PFM. Here, we present a modular, dynamic, scalable reassignment algorithm suitable for use in such a system. Polycrystal modeling with grain growth and stress require careful tracking of each grain’s position and orientation which is lost when using a reduced order parameter set. In conclusion, the method presented in this paper maintains a unique ID for each grain even after reassignment, to allow the PFM to be tightly coupled to calculations of the stress throughout the polycrystal. Implementation details and comparative results of our approach are presented.« less

  5. NanoSIMS, TEM, and XANES studies of a unique presolar supernova graphite grain

    SciTech Connect (OSTI)

    Groopman, Evan; Bernatowicz, Thomas; Zinner, Ernst; Nittler, Larry R.

    2014-07-20

    We report on isotopic and microstructural investigations of a unique presolar supernova (SN) graphite grain, referred to as G6, isolated from the Orgueil CI chondrite. G6 contains complex heterogeneities in its isotopic composition and in its microstructure. Nano-scale secondary ion mass spectrometer isotope images of ultramicrotome sections reveal heterogeneities in its C, N, and O isotopic compositions, including anomalous shell-like structures. Transmission electron microscope studies reveal a nanocrystalline core surrounded by a turbostratic graphite mantle, the first reported nanocrystalline core from a low-density SN graphite grain. Electron diffraction analysis shows that the nanocrystalline core consists of randomly oriented 2-4 nm graphene particles, similar to those in cores of high-density (HD) presolar graphite grains from asymptotic giant branch stars. G6's core also exhibits evidence for planar stacking of these graphene nano-sheets with a domain size up to 4.5 nm, which was unobserved in the nanocrystalline cores of HD graphite grains. We also report on X-ray absorption near-edge structure measurements of G6. The complex isotopic- and micro-structure of G6 provides evidence for mixing and/or granular transport in SN ejecta.

  6. Carbide/nitride grain refined rare earth-iron-boron permanent magnet and method of making

    DOE Patents [OSTI]

    McCallum, R. William; Branagan, Daniel J.

    1996-01-23

    A method of making a permanent magnet wherein 1) a melt is formed having a base alloy composition comprising RE, Fe and/or Co, and B (where RE is one or more rare earth elements) and 2) TR (where TR is a transition metal selected from at least one of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and Al) and at least one of C and N are provided in the base alloy composition melt in substantially stoichiometric amounts to form a thermodynamically stable compound (e.g. TR carbide, nitride or carbonitride). The melt is rapidly solidified in a manner to form particulates having a substantially amorphous (metallic glass) structure and a dispersion of primary TRC, TRN and/or TRC/N precipitates. The amorphous particulates are heated above the crystallization temperature of the base alloy composition to nucleate and grow a hard magnetic phase to an optimum grain size and to form secondary TRC, TRN and/or TRC/N precipitates dispersed at grain boundaries. The crystallized particulates are consolidated at an elevated temperature to form a shape. During elevated temperature consolidation, the primary and secondary precipitates act to pin the grain boundaries and minimize deleterious grain growth that is harmful to magnetic properties.

  7. Carbide/nitride grain refined rare earth-iron-boron permanent magnet and method of making

    DOE Patents [OSTI]

    McCallum, R.W.; Branagan, D.J.

    1996-01-23

    A method of making a permanent magnet is disclosed wherein (1) a melt is formed having a base alloy composition comprising RE, Fe and/or Co, and B (where RE is one or more rare earth elements) and (2) TR (where TR is a transition metal selected from at least one of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and Al) and at least one of C and N are provided in the base alloy composition melt in substantially stoichiometric amounts to form a thermodynamically stable compound (e.g. TR carbide, nitride or carbonitride). The melt is rapidly solidified in a manner to form particulates having a substantially amorphous (metallic glass) structure and a dispersion of primary TRC, TRN and/or TRC/N precipitates. The amorphous particulates are heated above the crystallization temperature of the base alloy composition to nucleate and grow a hard magnetic phase to an optimum grain size and to form secondary TRC, TRN and/or TRC/N precipitates dispersed at grain boundaries. The crystallized particulates are consolidated at an elevated temperature to form a shape. During elevated temperature consolidation, the primary and secondary precipitates act to pin the grain boundaries and minimize deleterious grain growth that is harmful to magnetic properties. 33 figs.

  8. Concentrations and Size Distributions of Particulate Matter Emissions...

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

    Devices on the Emission Profiles of Trucks and Buses CNG and Diesel Transite Bus Emissions in Review ARB's Study of Emissions from Diesel and CNG Heavy-duty Transit Buses

  9. Dispersion of Cloud Droplet Size Distributions, Cloud Parameterization...

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

    Broomfield, Colorado, March 31-April 4, 2003 indicates that for a given liquid water content and droplet concentration, the effect of spectral dispersion alone can cause...

  10. Characterization of Vertical Velocity and Drop Size Distribution...

    Office of Scientific and Technical Information (OSTI)

    to within the typical uncertainty of the retrieval methods. ... This study will be useful in assessing uncertainties ... Country of Publication: United States Language: English ...

  11. Measurements of stress fields near a grain boundary: Exploring blocked arrays of dislocations in 3D

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

    Guo, Y.; Collins, D. M.; Tarleton, E.; Hofmann, F.; Tischler, J.; Liu, W.; Xu, R.; Wilkinson, A. J.; Britton, T. B.

    2015-06-24

    The interaction between dislocation pile-ups and grain boundaries gives rise to heterogeneous stress distributions when a structural metal is subjected to mechanical loading. Such stress heterogeneity leads to preferential sites for damage nucleation and therefore is intrinsically linked to the strength and ductility of polycrystalline metals. To date the majority of conclusions have been drawn from 2D experimental investigations at the sample surface, allowing only incomplete observations. Our purpose here is to significantly advance the understanding of such problems by providing quantitative measurements of the effects of dislocation pile up and grain boundary interactions in 3D. This is accomplished throughmore » the application of differential aperture X-ray Laue micro-diffraction (DAXM) and high angular resolution electron backscatter diffraction (HR-EBSD) techniques. Our analysis demonstrates a similar strain characterization capability between DAXM and HR-EBSD and the variation of stress intensity in 3D reveals that different parts of the same grain boundary may have different strengths in resisting slip transfer, likely due to the local grain boundary curvature.« less

  12. Grain-boundary strengthening in nanocrystalline chromium and the Hall- Petch coefficient of body-centered cubic metals

    SciTech Connect (OSTI)

    Wu, Dong; Junyan, Zhang; Huang, J C; Bei, Hongbin; Nieh, Tai-Gang

    2013-01-01

    Nanocrystalline Cr (nc-Cr) was synthesized by electrodeposition. Samples with various grain sizes (19 57 nm) were prepared by annealing the as-deposited sample. Microstructures were examined using X-ray and electron microscopy, and the mechanical prop- erties were evaluated using nanoindentation. The strength of nc-Cr samples apparently obeyed the classical Hall Petch relationship. It was found that hardening potency caused by grain refinement was generally higher in body-centered cubic metals than that in face-centered cubic and hexagonal close-packed metals. A possible explanation was offered.

  13. Experiences in Large Grain-Single Crystal Cavity Fabrication

    SciTech Connect (OSTI)

    Pekeler, Michael; Schwellenbach, Johannes; Tradt, Marco

    2007-08-09

    At ACCEL instruments several single cell and 9-cell cavities have been produced out of large grain niobium sheets from different suppliers. The fabrication experience and difference to the production out of fine grain niobium sheets will be described. In addition two cavities were produced using single crystal niobium sheets. The final cavities showed no grain boundaries at all in the cavity cell, even not in the electron beam welding seam.

  14. New Process for Grain Refinement of Aluminum. Final Report

    SciTech Connect (OSTI)

    Dr. Joseph A. Megy

    2000-09-22

    A new method of grain refining aluminum involving in-situ formation of boride nuclei in molten aluminum just prior to casting has been developed in the subject DOE program over the last thirty months by a team consisting of JDC, Inc., Alcoa Technical Center, GRAS, Inc., Touchstone Labs, and GKS Engineering Services. The Manufacturing process to make boron trichloride for grain refining is much simpler than preparing conventional grain refiners, with attendant environmental, capital, and energy savings. The manufacture of boride grain refining nuclei using the fy-Gem process avoids clusters, salt and oxide inclusions that cause quality problems in aluminum today.

  15. Numerical Simulation of Ni Grain Growth in a Thermal Gradient

    Office of Scientific and Technical Information (OSTI)

    665C Numerical Simulation of Ni Grain Growth in a Thermal Gradient Sandia National Laboratories John A. Mitchell and Veena Tikare Sandia National Laboratories, Albuquerque New ...

  16. Coarse-grained Energy Modeling of Rollback/Recovery Mechanisms...

    Office of Scientific and Technical Information (OSTI)

    Title: Coarse-grained Energy Modeling of RollbackRecovery Mechanisms. Abstract not provided. Authors: Ferreira, Kurt Brian ; Ibtesham, Dewan ; DeBonis, David ; Arnold, Dorian ...

  17. Interactions between Grain Rotation and Local Deformation. (Conference...

    Office of Scientific and Technical Information (OSTI)

    Title: Interactions between Grain Rotation and Local Deformation. Abstract not provided. Authors: Carroll, Jay ; Lim, Hojun ; Boyce, Brad Lee ; Battaile, Corbett Chandler. ; ...

  18. [Perovskite and Fluorite Grain Boundary Properties]. Final Project Report

    SciTech Connect (OSTI)

    Browning, N. D.

    2004-02-24

    One of the main areas of research in the last two years in this program has been the properties of grain boundaries in perovskite and fluorite structure materials.

  19. On the interaction of solutes with grain boundaries (Journal...

    Office of Scientific and Technical Information (OSTI)

    is considered by modeling solute atoms as misfitting inclusions within a disclination structural unit model describing the grain boundary structure and its intrinsic stress field. ...

  20. Distribution Workshop

    Broader source: Energy.gov [DOE]

    On September 24-26, 2012, the GTT presented a workshop on grid integration on the distribution system at the Sheraton Crystal City near Washington, DC.

  1. Distributed Generation

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

    and regulations such as IEEE (Institute of Electrical and Electronics Engineers) 1547 have come a long way in addressing interconnection standards for distributed generation, ...

  2. Method of aeration disinfecting and drying grain in bulk and pretreating seeds and a transverse blow silo grain dryer therefor

    DOE Patents [OSTI]

    Danchenko, Vitaliy G.; Noyes, Ronald T.; Potapovych, Larysa P.

    2012-02-28

    Aeration drying and disinfecting grain crops in bulk and pretreating seeds includes passing through a bulk of grain crops and seeds disinfecting and drying agents including an ozone and air mixture and surrounding air, subdividing the disinfecting and drying agents into a plurality of streams spaced from one another in a vertical direction, and passing the streams at different heights through levels located at corresponding heights of the bulk of grain crops and seeds transversely in a substantially horizontal direction.

  3. Droplet sizes, dynamics and deposition in vertical annular flow

    SciTech Connect (OSTI)

    Lopes, J C.B.; Dukler, A E

    1985-10-01

    The role of droplets in vertical upwards annular flow is investigated, focusing on the droplet size distributions, dynamics, and deposition phenomena. An experimental program was performed based on a new laser optical technique developed in these laboratories and implemented here for annular flow. This permitted the simultaneous measurement of droplet size, axial and radial velocity. The dependence of droplet size distributions on flow conditions is analyzed. The Upper-Log Normal function proves to be a good model for the size distribution. The mechanism controlling the maximum stable drop size was found to result from the interaction of the pressure fluctuations of the turbulent flow of the gas core with the droplet. The average axial droplet velocity showed a weak dependence on gas rates. This can be explained once the droplet size distribution and droplet size-velocity relationship are analyzed simultaneously. The surprising result from the droplet conditional analysis is that larger droplet travel faster than smaller ones. This dependence cannot be explained if the drag curves used do not take into account the high levels of turbulence present in the gas core in annular flow. If these are considered, then interesting new situations of multiplicity and stability of droplet terminal velocities are encountered. Also, the observed size-velocity relationship can be explained. A droplet deposition is formulated based on the particle inertia control. This permitted the calculation of rates of drop deposition directly from the droplet size and velocities data.

  4. Stochastic thermodynamics of fluctuating density fields: Non-equilibrium free energy differences under coarse-graining

    SciTech Connect (OSTI)

    Leonard, T.; Lander, B.; Seifert, U.; Speck, T.

    2013-11-28

    We discuss the stochastic thermodynamics of systems that are described by a time-dependent density field, for example, simple liquids and colloidal suspensions. For a time-dependent change of external parameters, we show that the Jarzynski relation connecting work with the change of free energy holds if the time evolution of the density follows the Kawasaki-Dean equation. Specifically, we study the work distributions for the compression and expansion of a two-dimensional colloidal model suspension implementing a practical coarse-graining scheme of the microscopic particle positions. We demonstrate that even if coarse-grained dynamics and density functional do not match, the fluctuation relations for the work still hold albeit for a different, apparent, change of free energy.

  5. Effects of rolling temperature and subsequent annealing on mechanical properties of ultrafine-grained Cu–Zn–Si alloy

    SciTech Connect (OSTI)

    Zhang, Xiangkai; Yang, Xuyue; Chen, Wei; Qin, Jia; Fouse, Jiaping

    2015-08-15

    The effects of rolling temperature and subsequent annealing on mechanical properties of Cu–Zn–Si alloy were investigated by using X-ray diffraction, transmission electron microscope, electron back scattered diffraction and tensile tests. The Cu–Zn–Si alloy has been processed at cryogenic temperature (approximately 77 K) and room temperature up to different rolling strains. It has been identified that the cryorolled Cu–Zn–Si alloy samples show a higher strength compared with those room temperature rolled samples. The improved strength of cryorolled samples is resulted from grain size effect and higher densities of dislocations and deformation twins. And subsequent annealing, as a post-heat treatment, enhanced the ductility. An obvious increase in uniform elongation appears when the volume fraction of static recrystallization grains exceeds 25%. The strength–ductility combination of the annealed cryorolled samples is superior to that of annealed room temperature rolled samples, owing to the finer grains, high fractions of high angle grain boundaries and twins. - Highlights: • An increase in hardness of Cu–Zn–Si alloy is noticed during annealing process. • Thermal stability is reduced in Cu–Zn–Si alloy by cryorolling. • An obvious enhancement in UE is noticed when fraction of SRX grains exceeds 25%. • A superior strength–ductility combination is achieved in the cryorolling samples.

  6. How Distributed Wind Works | Department of Energy

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

    How Distributed Wind Works How Distributed Wind Works Your browser does not support iframes. Distributed wind energy systems are commonly installed on, but are not limited to, residential, agricultural, commercial, industrial, and community sites, and can range in size from a 5-kilowatt turbine at a home to a multi-megawatt (MW) turbine at a manufacturing facility. Distributed wind systems are connected on the customer side of the meter to meet the onsite load or directly to distribution or

  7. Irradiation Assisted Grain Boundary Segregation in Steels

    SciTech Connect (OSTI)

    Lu, Zheng; Faulkner, Roy G.

    2008-07-01

    The understanding of radiation-induced grain boundary segregation (RIS) has considerably improved over the past decade. New models have been introduced and much effort has been devoted to obtaining comprehensive information on segregation from the literature. Analytical techniques have also improved so that chemical analysis of layers 1 nm thick is almost routine. This invited paper will review the major methods used currently for RIS prediction: namely, Rate Theory, Inverse Kirkendall, and Solute Drag approaches. A summary is made of the available data on phosphorus RIS in reactor pressure vessel (RPV) steels. This will be discussed in the light of the predictions of the various models in an effort to show which models are the most reliable and easy to use for forecasting P segregation behaviour in steels. A consequence of RIS in RPV steels is a radiation induced shift in the ductile to brittle transition temperature (DBTT). It will be shown how it is possible to relate radiation-induced P segregation levels to DBTT shift. Examples of this exercise will be given for RPV steels and for ferritic steels being considered for first wall fusion applications. Cr RIS in high alloy stainless steels and associated irradiation-assisted stress corrosion cracking (IASCC) will be briefly discussed. (authors)

  8. ITP Industrial Distributed Energy: Distributed Energy Program...

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

    ITP Industrial Distributed Energy: Distributed Energy Program Project Profile: Verizon Central Office Building ITP Industrial Distributed Energy: Distributed Energy Program Project ...

  9. Femtosecond laser-induced size reduction of carbon nanodots in solution: Effect of laser fluence, spot size, and irradiation time

    SciTech Connect (OSTI)

    Nguyen, Vanthan; Yan, Lihe Si, Jinhai; Hou, Xun

    2015-02-28

    Photoluminescent carbon nanodots (C-dots) with size tunability and uniformity were fabricated in polyethylene glycol (PEG{sub 200N}) solution using femtosecond laser ablation method. The size distributions and photoluminescence (PL) properties of C-dots are well controlled by adjusting the combined parameters of laser fluence, spot size, and irradiation time. The size reduction efficiency of the C-dots progressively increases with decreasing laser fluence and spot size. The optimal PL spectra are red-shifted and the quantum yields decrease with the increase in C-dots size, which could be attributed to the more complex surface functional groups attached on C-dots induced at higher laser fluence and larger spot size. Moreover, an increase in irradiation time leads to a decrease in size of C-dots, but long-time irradiation will result in the generation of complex functional groups on C-dots, subsequently the PL spectra are red-shifted.

  10. Traction–separation relationships for hydrogen induced grain boundary embrittlement in nickel via molecular dynamics simulations

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

    Barrows, Wesley; Dingreville, Rémi; Spearot, Douglas

    2015-10-19

    A statistical approach combined with molecular dynamics simulations is used to study the influence of hydrogen on intergranular decohesion. This methodology is applied to a Ni Σ3(112)[11¯0] symmetric tilt grain boundary. Hydrogenated grain boundaries with different H concentrations are constructed using an energy minimization technique with initial H atom positions guided by Monte Carlo simulation results. Decohesion behavior is assessed through extraction of a traction–separation relationship during steady-state crack propagation in a statistically meaningful approach, building upon prior work employing atomistic cohesive zone volume elements (CZVEs). A sensitivity analysis is performed on the numerical approach used to extract the traction–separationmore » relationships, clarifying the role of CZVE size, threshold parameters necessary to differentiate elastic and decohesion responses, and the numerical averaging technique. Results show that increasing H coverage at the Ni Σ3(112)[11¯0] grain boundary asymmetrically influences the crack tip velocity during propagation, leads to a general decrease in the work of separation required for crack propagation, and provides a reduction in the peak stress in the extracted traction–separation relationship. Furthermore the present framework offers a meaningful vehicle to pass atomistically derived interfacial behavior to higher length scale formulations for intergranular fracture.« less

  11. Fabrication of fine-grain tantalum diffusion barrier tube for Nb{sub 3}Sn conductors

    SciTech Connect (OSTI)

    Hartwig, K. T.; Balachandran, S.; Mezyenski, R.; Seymour, N.; Robinson, J.; Barber, R. E.

    2014-01-27

    Diffusion barriers used in Nb{sub 3}Sn wire are often fabricated by wrapping Ta sheet into a tube with an overlap seam. A common result of such practice is non-uniform deformation in the Ta sheet as it thins by wire drawing because of non-uniform grain size and texture in the original Ta sheet. Seamless Ta tube with a fine-grain and uniform microstructure would be much better for the diffusion barrier application, but such material is expensive and difficult to manufacture. This report presents results on a new fabrication strategy for Ta tube that shows promise for manufacture of less costly tube with an improved microstructure. The fabrication method begins with seam-welded tube but gives a fine-grain uniform microstructure with little difference between the longitudinal seam weld region and the parent metal after post-weld processing. Severe plastic deformation processing (SPD) applied by area reduction extrusion and tube equal channel angular extrusion (tECAE) are used to refine and homogenize the microstructure. Microstructure and mechanical property results are presented for Ta tubes fabricated by this new processing strategy.

  12. Synthesis and characterization of large-grain solid-phase crystallized polycrystalline silicon thin films

    SciTech Connect (OSTI)

    Kumar, Avishek, E-mail: avishek.kumar@nus.edu.sg, E-mail: dalapatig@imre.a-star.edu.sg [Solar Energy Research Institute of Singapore, National University of Singapore, 7 Engineering Drive 1, Block E3A, #06-01, Singapore 117574 (Singapore); Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583 (Singapore); Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602 (Singapore); Law, Felix; Widenborg, Per I. [Solar Energy Research Institute of Singapore, National University of Singapore, 7 Engineering Drive 1, Block E3A, #06-01, Singapore 117574 (Singapore); Dalapati, Goutam K., E-mail: avishek.kumar@nus.edu.sg, E-mail: dalapatig@imre.a-star.edu.sg; Subramanian, Gomathy S.; Tan, Hui R. [Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602 (Singapore); Aberle, Armin G. [Solar Energy Research Institute of Singapore, National University of Singapore, 7 Engineering Drive 1, Block E3A, #06-01, Singapore 117574 and Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583 (Singapore)

    2014-11-01

    n-type polycrystalline silicon (poly-Si) films with very large grains, exceeding 30??m in width, and with high Hall mobility of about 71.5?cm{sup 2}/V s are successfully prepared by the solid-phase crystallization technique on glass through the control of the PH{sub 3} (2% in H{sub 2})/SiH{sub 4} gas flow ratio. The effect of this gas flow ratio on the electronic and structural quality of the n-type poly-Si thin film is systematically investigated using Hall effect measurements, Raman microscopy, and electron backscatter diffraction (EBSD), respectively. The poly-Si grains are found to be randomly oriented, whereby the average area weighted grain size is found to increase from 4.3 to 18??m with increase of the PH{sub 3} (2% in H{sub 2})/SiH{sub 4} gas flow ratio. The stress in the poly-Si thin films is found to increase above 900?MPa when the PH{sub 3} (2% in H{sub 2})/SiH{sub 4} gas flow ratio is increased from 0.025 to 0.45. Finally, high-resolution transmission electron microscopy, high angle annular dark field-scanning tunneling microscopy, and EBSD are used to identify the defects and dislocations caused by the stress in the fabricated poly-Si films.

  13. Tractionseparation relationships for hydrogen induced grain boundary embrittlement in nickel via molecular dynamics simulations

    SciTech Connect (OSTI)

    Barrows, Wesley; Dingreville, Rmi; Spearot, Douglas

    2015-10-19

    A statistical approach combined with molecular dynamics simulations is used to study the influence of hydrogen on intergranular decohesion. This methodology is applied to a Ni ?3(112)[110] symmetric tilt grain boundary. Hydrogenated grain boundaries with different H concentrations are constructed using an energy minimization technique with initial H atom positions guided by Monte Carlo simulation results. Decohesion behavior is assessed through extraction of a tractionseparation relationship during steady-state crack propagation in a statistically meaningful approach, building upon prior work employing atomistic cohesive zone volume elements (CZVEs). A sensitivity analysis is performed on the numerical approach used to extract the tractionseparation relationships, clarifying the role of CZVE size, threshold parameters necessary to differentiate elastic and decohesion responses, and the numerical averaging technique. Results show that increasing H coverage at the Ni ?3(112)[110] grain boundary asymmetrically influences the crack tip velocity during propagation, leads to a general decrease in the work of separation required for crack propagation, and provides a reduction in the peak stress in the extracted tractionseparation relationship. Furthermore the present framework offers a meaningful vehicle to pass atomistically derived interfacial behavior to higher length scale formulations for intergranular fracture.

  14. Ultrafast visualization of crystallization and grain growth in shock-compressed SiO2

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

    Gleason, A. E.; Bolme, C. A.; Lee, H. J.; Nagler, B.; Galtier, E.; Milathianaki, D.; Hawreliak, J.; Kraus, R. G.; Eggert, J. H.; Fratanduono, D. E.; et al

    2015-09-04

    Pressure- and temperature-induced phase transitions have been studied for more than a century but very little is known about the non-equilibrium processes by which the atoms rearrange. Shock compression generates a nearly instantaneous propagating high-pressure/temperature condition while in situ X-ray diffraction (XRD) probes the time-dependent atomic arrangement. Here we present in situ pump–probe XRD measurements on shock-compressed fused silica, revealing an amorphous to crystalline high-pressure stishovite phase transition. Using the size broadening of the diffraction peaks, the growth of nanocrystalline stishovite grains is resolved on the nanosecond timescale just after shock compression. At applied pressures above 18 GPa the nuclueationmore » of stishovite appears to be kinetically limited to 1.4±0.4 ns. The functional form of this grain growth suggests homogeneous nucleation and attachment as the growth mechanism. As a result, these are the first observations of crystalline grain growth in the shock front between low- and high-pressure states via XRD.« less

  15. Magnetic agglomeration method for size control in the synthesis of magnetic nanoparticles

    DOE Patents [OSTI]

    Huber, Dale L.

    2011-07-05

    A method for controlling the size of chemically synthesized magnetic nanoparticles that employs magnetic interaction between particles to control particle size and does not rely on conventional kinetic control of the reaction to control particle size. The particles are caused to reversibly agglomerate and precipitate from solution; the size at which this occurs can be well controlled to provide a very narrow particle size distribution. The size of particles is controllable by the size of the surfactant employed in the process; controlling the size of the surfactant allows magnetic control of the agglomeration and precipitation processes. Agglomeration is used to effectively stop particle growth to provide a very narrow range of particle sizes.

  16. A coarse-grained model for PETN crystals

    SciTech Connect (OSTI)

    Gee, R; Wu, C; Maiti, A

    2006-02-10

    Using the energetic material Pentaerythritol Tetranitrate (PETN) as a specific example of molecular crystal, we describe the development of a simple coarse-graining procedure by grouping several atoms or whole functional groups into single charge-neutral beads. As compared to fully atomistic calculations the coarse-grained model speeds up simulations by more than two orders of magnitude. Yet, by adjusting only two parameters in the coarse-grained interaction, the model accurately predicts the lattice constants, sublimation energy, pressure-volume curve up to P=10 GPa, and energetically the most stable facets. Computed surface and desorption energies, bulk modulus, and equilibrium morphology are reported as well.

  17. Manufacturing process to reduce large grain growth in zirconium alloys

    DOE Patents [OSTI]

    Rosecrans, P.M.

    1984-08-01

    It is an object of the present invention to provide a procedure for desensitizing zirconium-based alloys to large grain growth (LGG) during thermal treatment above the recrystallization temperature of the alloy. It is a further object of the present invention to provide a method for treating zirconium-based alloys which have been cold-worked in the range of 2 to 8% strain to reduce large grain growth. It is another object of the present invention to provide a method for fabricating a zirconium alloy clad nuclear fuel element wherein the zirconium clad is resistant to large grain growth.

  18. Uranium vacancy mobility at the sigma 5 symmetric tilt grain boundary in UO2

    SciTech Connect (OSTI)

    Uberuaga, Blas P.

    2012-05-02

    An important consequence of the fissioning process occurring during burnup is the formation of fission products. These fission products alter the thermo-mechanical properties of the fuel. They also lead to macroscopic changes in the fuel structure, including the formation of bubbles that are connected to swelling of the fuel. Subsequent release of fission gases increase the pressure in the plenum and can cause changes in the properties of the fuel pin itself. It is thus imperative to understand how fission products, and fission gases in particular, behave within the fuel in order to predict the performance of the fuel under operating conditions. Fission gas redistribution within the fuel is governed by mass transport and the presence of sinks such as impurities, dislocations, and grain boundaries. Thus, to understand how the distribution of fission gases evolves in the fuel, we must understand the underlying transport mechanisms, tied to the concentrations and mobilities of defects within the material, and how these gases interact with microstructural features that might act as sinks. Both of these issues have been addressed in previous work under NEAMS. However, once a fission product has reached a sink, such as a grain boundary, its mobility may be different there than in the grain interior and predicting how, for example, bubbles nucleate within grain boundaries necessitates an understanding of how fission gases diffuse within boundaries. That is the goal of the present work. In this report, we describe atomic level simulations of uranium vacancy diffusion in the pressence of a {Sigma}5 symmetric tilt boundary in urania (UO{sub 2}). This boundary was chosen as it is the simplest of the boundaries we considered in previous work on segregation and serves as a starting point for understanding defect mobility at boundaries. We use a combination of molecular statics calculations and kinetic Monte Carlo (kMC) to determine how the mobility of uranium vacancies is

  19. Impact of aerosol size representation on modeling aerosol-cloud interactions: AEROSOL SIZE REPRESENTATION

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

    Zhang, Y.; Easter, R. C.; Ghan, S. J.; Abdul-Razzak, H.

    2002-11-07

    We use a 1-D version of a climate-aerosol-chemistry model with both modal and sectional aerosol size representations to evaluate the impact of aerosol size representation on modeling aerosol-cloud interactions in shallow stratiform clouds observed during the 2nd Aerosol Characterization Experiment. Both the modal (with prognostic aerosol number and mass or prognostic aerosol number, surface area and mass, referred to as the Modal-NM and Modal-NSM) and the sectional approaches (with 12 and 36 sections) predict total number and mass for interstitial and activated particles that are generally within several percent of references from a high resolution 108-section approach. The modal approachmore » with prognostic aerosol mass but diagnostic number (referred to as the Modal-M) cannot accurately predict the total particle number and surface areas, with deviations from the references ranging from 7-161%. The particle size distributions are sensitive to size representations, with normalized absolute differences of up to 12% and 37% for the 36- and 12-section approaches, and 30%, 39%, and 179% for the Modal-NSM, Modal-NM, and Modal-M, respectively. For the Modal-NSM and Modal-NM, differences from the references are primarily due to the inherent assumptions and limitations of the modal approach. In particular, they cannot resolve the abrupt size transition between the interstitial and activated aerosol fractions. For the 12- and 36-section approaches, differences are largely due to limitations of the parameterized activation for non-log-normal size distributions, plus the coarse resolution for the 12-section case. Differences are larger both with higher aerosol (i.e., less complete activation) and higher SO2 concentrations (i.e., greater modification of the initial aerosol distribution).« less

  20. Process for preparing fine grain silicon carbide powder

    DOE Patents [OSTI]

    Wei, G.C.

    Method of producing fine-grain silicon carbide powder comprises combining methyltrimethoxysilane with a solution of phenolic resin, acetone and water or sugar and water, gelling the resulting mixture, and then drying and heating the obtained gel.

  1. How chip size impacts steam pretreatment effectiveness for biological conversion of poplar wood into fermentable sugars

    SciTech Connect (OSTI)

    DeMartini, Jaclyn D.; Foston, Marcus; Meng, Xianzhi; Jung, Seokwon; Kumar, Rajeev; Ragauskas, Arthur J.; Wyman, Charles E.

    2015-12-09

    We report that woody biomass is highly recalcitrant to enzymatic sugar release and often requires significant size reduction and severe pretreatments to achieve economically viable sugar yields in biological production of sustainable fuels and chemicals. However, because mechanical size reduction of woody biomass can consume significant amounts of energy, it is desirable to minimize size reduction and instead pretreat larger wood chips prior to biological conversion. To date, however, most laboratory research has been performed on materials that are significantly smaller than applicable in a commercial setting. As a result, there is a limited understanding of the effects that larger biomass particle size has on the effectiveness of steam explosion pretreatment and subsequent enzymatic hydrolysis of wood chips. To address these concerns, novel downscaled analysis and high throughput pretreatment and hydrolysis (HTPH) were applied to examine whether differences exist in the composition and digestibility within a single pretreated wood chip due to heterogeneous pretreatment across its thickness. Heat transfer modeling, Simons’ stain testing, magnetic resonance imaging (MRI), and scanning electron microscopy (SEM) were applied to probe the effects of pretreatment within and between pretreated wood samples to shed light on potential causes of variation, pointing to enzyme accessibility (i.e., pore size) distribution being a key factor dictating enzyme digestibility in these samples. Application of these techniques demonstrated that the effectiveness of pretreatment of Populus tremuloides can vary substantially over the chip thickness at short pretreatment times, resulting in spatial digestibility effects and overall lower sugar yields in subsequent enzymatic hydrolysis. Finally, these results indicate that rapid decompression pretreatments (e.g., steam explosion) that specifically alter accessibility at lower temperature conditions are well suited for larger wood

  2. How chip size impacts steam pretreatment effectiveness for biological conversion of poplar wood into fermentable sugars

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

    DeMartini, Jaclyn D.; Foston, Marcus; Meng, Xianzhi; Jung, Seokwon; Kumar, Rajeev; Ragauskas, Arthur J.; Wyman, Charles E.

    2015-12-09

    We report that woody biomass is highly recalcitrant to enzymatic sugar release and often requires significant size reduction and severe pretreatments to achieve economically viable sugar yields in biological production of sustainable fuels and chemicals. However, because mechanical size reduction of woody biomass can consume significant amounts of energy, it is desirable to minimize size reduction and instead pretreat larger wood chips prior to biological conversion. To date, however, most laboratory research has been performed on materials that are significantly smaller than applicable in a commercial setting. As a result, there is a limited understanding of the effects that largermore » biomass particle size has on the effectiveness of steam explosion pretreatment and subsequent enzymatic hydrolysis of wood chips. To address these concerns, novel downscaled analysis and high throughput pretreatment and hydrolysis (HTPH) were applied to examine whether differences exist in the composition and digestibility within a single pretreated wood chip due to heterogeneous pretreatment across its thickness. Heat transfer modeling, Simons’ stain testing, magnetic resonance imaging (MRI), and scanning electron microscopy (SEM) were applied to probe the effects of pretreatment within and between pretreated wood samples to shed light on potential causes of variation, pointing to enzyme accessibility (i.e., pore size) distribution being a key factor dictating enzyme digestibility in these samples. Application of these techniques demonstrated that the effectiveness of pretreatment of Populus tremuloides can vary substantially over the chip thickness at short pretreatment times, resulting in spatial digestibility effects and overall lower sugar yields in subsequent enzymatic hydrolysis. Finally, these results indicate that rapid decompression pretreatments (e.g., steam explosion) that specifically alter accessibility at lower temperature conditions are well suited for larger

  3. Grained composite materials prepared by combustion synthesis under mechanical pressure

    DOE Patents [OSTI]

    Dunmead, Stephen D.; Holt, Joseph B.; Kingman, Donald D.; Munir, Zuhair A.

    1990-01-01

    Dense, finely grained composite materials comprising one or more ceramic phase or phase and one or more metallic and/or intermetallic phase or phases are produced by combustion synthesis. Spherical ceramic grains are homogeneously dispersed within the matrix. Methods are provided, which include the step of applying mechanical pressure during or immediately after ignition, by which the microstructures in the resulting composites can be controllably selected.

  4. Grain ethanol as a petroleum substitute: a perspective

    SciTech Connect (OSTI)

    Alston, T.G.

    1980-04-01

    Present tax exemptions for gasohol are more than sufficient to move ethanol into the gasoline market in a number of states. The principal near-term response to this profit opportunity, production of ethanol from feed grains, matches a limited biomass resource to an enormous market. This report estimates upper-bound prices for feed grains resulting from gasohol tax exemptions and concludes that grain price increases could be substantial. As shown else-where by Alston and Asbury, industrial uses constitute a more economical market for grain ethanol, one in which the product is now competitive with ethanol derived from petroleum and natural gas liquids. Without tax exemptions for gasohol, grain ethanol would now be displacing petroleum in the industrial market at a net economic gain, rather than in the fuel market at a net economic loss. The present analysis indicates that this industrial market for ethanol could grow significantly, principally by use of grain ethanol as an intermediate in production of chemicals now derived from petroleum and natural gas.

  5. Molecular dynamics simulations of grain boundaries in thin nanocrystalline silicon films

    SciTech Connect (OSTI)

    Berman, G.P.; Doolen, G.D.; Mainieri, R.; Campbell, D.K.; Luchnikov, V.A. |

    1997-10-01

    Using molecular dynamics simulations, the grain boundaries in thin polycrystalline silicon films (considered as promising material for future nanoelectronic devices) are investigated. It is shown that in polysilicon film with randomly oriented grains the majority of grain boundaries are disordered. However, some grains with small mutual orientation differences can form extended crystalline patterns. The structure of the grain boundaries satisfies the thermodynamical criterion. The majority of atoms in the grain boundaries are tetrahedrally coordinated with the nearest neighbors, even though the grain boundaries are disordered. The grain boundary matter is characterized as an amorphous phase with a characteristic tetragonality value.

  6. Distributed Generation

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

    Untapped Value of Backup Generation While new guidelines and regulations such as IEEE (Institute of Electrical and Electronics Engineers) 1547 have come a long way in addressing interconnection standards for distributed generation, utilities have largely overlooked the untapped potential of these resources. Under certain conditions, these units (primarily backup generators) represent a significant source of power that can deliver utility services at lower costs than traditional centralized

  7. Distribution Category:

    Office of Legacy Management (LM)

    - Distribution Category: Remedial Action and Decommissioning Program (UC-70A) DOE/EV-0005/48 ANL-OHS/HP-84-104 ARGONNE NATIONAL LABORATORY 9700 South Cass Avenue Argonne, Illinois 60439 FORMERLY UTILIZED MXD/AEC SITES REMEDIAL ACTION PROGRAM RADIOLOGICAL SURVEY OF THE HARSHAW CHEMICAL COMPANY CLEVELAND. OHIO Prepared by R. A. Wynveen Associate Division Director, OHS W. H. Smith Senior Health Physicist C. M. Sholeen Health Physicist A. L. Justus Health Physicist K. F. Flynn Health Physicist

  8. Strategic Petroleum Reserve: Analysis of size options

    SciTech Connect (OSTI)

    Not Available

    1990-02-01

    This report presents the results of the deliberations of the interagency group formed to study the costs and benefits of expanding the size of the SPR. The study concentrated on severe oil supply disruptions involving sharp reductions in world oil production that were 2 to 4 times larger than the largest 1970s interruption. The disruption sizes and estimated probability of occurrence of these scenarios were supplied by the CIA. The most critical part of the CIA's analysis was the assessment of likelihood of these cases occurring. The CIA approached the likelihood problem by combining an examination of past oil supply disruptions with qualitative analysis of important oil market and regional trends. The study group then used statistical techniques and probability distributions to synthesize the historical data with CIA evaluations of as yet unobserved events. The SPR size study assumed direct purchases of SPR oil and did not assume the use of alternative financing mechanisms. Members of the working group with foreign policy and national security responsibilities provided an in-depth review of strategic considerations affecting SPR size. A number of prior studies, some classified, have addressed the strategic importance and insurance value of the SPR to the US and its allies. The results of these studies have also been incorporated in the current effort. 10 refs., 5 figs.

  9. A temperature-dependent coarse-grained model for the thermoresponsive polymer poly(N-isopropylacrylamide)

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

    Abbott, Lauren J.; Stevens, Mark J.

    2015-12-22

    In this study, a coarse-grained (CG) model is developed for the thermoresponsive polymer poly(N-isopropylacrylamide) (PNIPAM), using a hybrid top-down and bottom-up approach. Nonbonded parameters are fit to experimental thermodynamic data following the procedures of the SDK (Shinoda, DeVane, and Klein) CG force field, with minor adjustments to provide better agreement with radial distribution functions from atomistic simulations. Bonded parameters are fit to probability distributions from atomistic simulations using multi-centered Gaussian-based potentials. The temperature-dependent potentials derived for the PNIPAM CG model in this work properly capture the coil–globule transition of PNIPAM single chains and yield a chain-length dependence consistent with atomisticmore » simulations.« less

  10. A temperature-dependent coarse-grained model for the thermoresponsive polymer poly(N-isopropylacrylamide)

    SciTech Connect (OSTI)

    Abbott, Lauren J.; Stevens, Mark J.

    2015-12-22

    In this study, a coarse-grained (CG) model is developed for the thermoresponsive polymer poly(N-isopropylacrylamide) (PNIPAM), using a hybrid top-down and bottom-up approach. Nonbonded parameters are fit to experimental thermodynamic data following the procedures of the SDK (Shinoda, DeVane, and Klein) CG force field, with minor adjustments to provide better agreement with radial distribution functions from atomistic simulations. Bonded parameters are fit to probability distributions from atomistic simulations using multi-centered Gaussian-based potentials. The temperature-dependent potentials derived for the PNIPAM CG model in this work properly capture the coil–globule transition of PNIPAM single chains and yield a chain-length dependence consistent with atomistic simulations.

  11. Biomass Engineering: Size reduction, drying and densification

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

    ... when high durability and stable pellets are needed - Energy efficient dryers (grain or belt dryers) can be used for drying high moisture pellets Fig. 3 TEA analysis of ...

  12. Decoding the message from meteoritic stardust silicon carbide grains

    SciTech Connect (OSTI)

    Lewis, Karen M.; Lugaro, Maria; Gibson, Brad K.; Pilkington, Kate

    2014-05-02

    SiC mainstream grains are presolar grains believed to form in the envelopes of carbon rich asymptotic giant branch (AGB) stars with masses between 1.5 and 3 solar masses. These grains represent a conundrum as the {sup 29}Si and {sup 30}Si abundances indicate that they formed in stars of super-solar metallicity, before the solar system formed. To shed light on this problem, we use silicon isotopic abundances to derive an age-metallicity relation for the stars believed to have produced the SiC mainstream grains. For 2732 mainstream SiC grains listed in the Presolar Grain Database, we use the {sup 29}Si abundances with the latest galactic chemical evolution (GCE) models to derive [Fe/H], and {sup 30}Si abundances along with the models of Zinner et al. (2006) to determine an approximate birth age for the parent AGB star. Comparing our age-metallicity relation with observational relationships derived for nearby stars, we find that the spread of [Fe/H] is in agreement, but the mean [Fe/H] in our relation is higher by 0.2 dex. We propose that this difference is because stars with higher [Fe/H] produce more dust and thus are over-represented in our age metallicity diagram, a finding consistent with previous published works. This result offers a solution for the long-standing problem of silicon in Stardust SiC grains, confirms the necessity of coupling chemistry and dynamics in simulations of the chemical evolution of our Galaxy, and constrains the modelling of dust condensation in stellar winds as a function of the metallicity.

  13. Wide size range fast integrated mobility spectrometer

    DOE Patents [OSTI]

    Wang, Jian

    2013-10-29

    A mobility spectrometer to measure a nanometer particle size distribution is disclosed. The mobility spectrometer includes a conduit and a detector. The conduit is configured to receive and provide fluid communication of a fluid stream having a charged nanometer particle mixture. The conduit includes a separator section configured to generate an electrical field of two dimensions transverse to a dimension associated with the flow of the charged nanometer particle mixture through the separator section to spatially separate charged nanometer particles of the charged nanometer particle mixture in said two dimensions. The detector is disposed downstream of the conduit to detect concentration and position of the spatially-separated nanometer particles.

  14. Glitter-Sized Solar Photovoltaics

    Broader source: Energy.gov [DOE]

    Featured in this photograph are tiny glitter-sized photovoltaic cells, developed by Sandia National Laboratories scientists, that could revolutionize the way solar energy is collected and used....

  15. The Effect of High Temperature Annealing on the Grain Characteristics of a Thin Chemical Vapor Deposition Silicon Carbide Layer.

    SciTech Connect (OSTI)

    Isabella J van Rooyen; Philippus M van Rooyen; Mary Lou Dunzik-Gougar

    2013-08-01

    The unique combination of thermo-mechanical and physiochemical properties of silicon carbide (SiC) provides interest and opportunity for its use in nuclear applications. One of the applications of SiC is as a very thin layer in the TRi-ISOtropic (TRISO) coated fuel particles for high temperature gas reactors (HTGRs). This SiC layer, produced by chemical vapor deposition (CVD), is designed to withstand the pressures of fission and transmutation product gases in a high temperature, radiation environment. Various researchers have demonstrated that macroscopic properties can be affected by changes in the distribution of grain boundary plane orientations and misorientations [1 - 3]. Additionally, various researchers have attributed the release behavior of Ag through the SiC layer as a grain boundary diffusion phenomenon [4 - 6]; further highlighting the importance of understanding the actual grain characteristics of the SiC layer. Both historic HTGR fission product release studies and recent experiments at Idaho National Laboratory (INL) [7] have shown that the release of Ag-110m is strongly temperature dependent. Although the maximum normal operating fuel temperature of a HTGR design is in the range of 1000-1250C, the temperature may reach 1600C under postulated accident conditions. The aim of this specific study is therefore to determine the magnitude of temperature dependence on SiC grain characteristics, expanding upon initial studies by Van Rooyen et al, [8; 9].

  16. Roles of grain boundaries on the semiconductor to metal phase transition of VO{sub 2} thin films

    SciTech Connect (OSTI)

    Jian, Jie; Jacob, Clement; Chen, Aiping; Zhang, Wenrui; Wang, Han; Huang, Jijie; Wang, Haiyan

    2015-09-07

    Vanadium dioxide (VO{sub 2}) thin films with controlled grain sizes are deposited on amorphous glass substrates by pulsed laser deposition. The grain boundaries (GBs) are found as the dominating defects in the thin films. The semiconductor to metal transition (SMT) properties of VO{sub 2} thin films are characterized and correlated to the GB density. The VO{sub 2} films with lower GB density exhibit a sharper SMT with a larger transition amplitude. A high resolution TEM study at GB area reveals the disordered atomic structures along the boundaries and the distorted crystal lattices near the boundaries. The VO{sub 2} SMT amplitude and sharpness could be directly related to these defects at and near the boundaries.

  17. Economic Viability of Brewery Spent Grain as a Biofuel

    SciTech Connect (OSTI)

    Morrow, Charles

    2016-01-01

    This report summarizes an investigation into the technical feasibility and economic viability of use grain wastes from the beer brewing process as fuel to generate the heat needed in subsequent brewing process. The study finds that while use of spent grain as a biofuel is technically feasible, the economics are not attractive. Economic viability is limited by the underuse of capital equipment. The investment in heating equipment requires a higher utilization that the client brewer currently anticipates. It may be possible in the future that changing factors may swing the decision to a more positive one.

  18. Continuous method for manufacturing grain-oriented magnetostrictive bodies

    DOE Patents [OSTI]

    Gibson, Edwin D.; Verhoeven, John D.; Schmidt, Frederick A.; McMasters, O. Dale

    1988-01-01

    The invention comprises a continuous casting and crystallization method for manufacturing grain-oriented magnetostrictive bodies. A magnetostrictive alloy is melted in a crucible having a bottom outlet. The melt is discharged through the bottom of the crucible and deposited in an elongated mold. Heat is removed from the deposited melt through the lower end portion of the mold to progressively solidify the melt. The solid-liquid interface of the melt moves directionally upwardly from the bottom to the top of the mold, to produce the axial grain orientation.

  19. Segregation and Migration of the Oxygen Vacancies in the 3 (111) Tilt Grain Boundaries of Ceria

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

    Yuan, Fenglin; Liu, Bin; Zhang, Yanwen; Weber, William J.

    2016-03-01

    In nanocrystalline materials, defect-grain boundary (GB) interaction plays a key role in determining the structure stability, as well as size-dependent ionic, electronic, magnetic and chemical properties. In this study, we systematically investigated using density functional theory segregation and migration of oxygen vacancies at the Σ3 [110] / (111) grain boundary of ceria. Three oxygen layers near the GB are predicted to be segregation sites for oxygen vacancies. Moreover, the presence of oxygen vacancies stabilizes this tilt GB at a low Fermi level and/or oxygen poor conditions. An atomic strain model was proposed to rationalize layer dependency of the relaxation energymore » for +2 charged oxygen vacancy. The structural origin of large relaxation energies at layers 1 and 2 was determined to be free-volume space that induces ion relaxation towards the GB. Our results not only pave the way for improving the oxygen transport near GBs of ceria, but also provide important insights into engineering the GB structure for better ionic, magnetic and chemical properties of nanocrystalline ceria.« less

  20. Defect distributions in weld-deposited cladding

    SciTech Connect (OSTI)

    Li, Y.Y.; Mabe, W.R.

    1998-11-01

    Defect distributions in stainless steel and nickel-chromium alloy weld-deposited cladding over a low alloy steel base were characterized by destructive evaluation (DE). An evaluation of the observed defects was conducted to characterize the defects by type or classification. Size distributions of cladding defect types were developed from the information obtained. This paper presents the results of the cladding evaluation.

  1. Method for sizing hollow microspheres

    DOE Patents [OSTI]

    Farnum, E.H.; Fries, R.J.

    1975-10-29

    Hollow Microspheres may be effectively sized by placing them beneath a screen stack completely immersed in an ultrasonic bath containing a liquid having a density at which the microspheres float and ultrasonically agitating the bath.

  2. FEA Simulations of Magnets with Grain Oriented Steel

    SciTech Connect (OSTI)

    Witte H.

    2012-08-06

    One of the potential successors of the Large Hadron Collider is a Muon Col- lider. Muons are short-lived particles, which therefore require fast acceleration. One potential avenue is a very fast cycling cyclotron, where the bending is sup- plied by a combination of fixed-field superconducting magnets and fast ramping normal conducting iron-cored coils. Due to the high ramping rate (around 1 kHz) eddy current and hysteresis losses are a concern. One way to overcome these is by using grain-oriented soft-iron, which promises superior magnetic properties in the direction of the grains. This note summarizes efforts to include the anisotropic material properties of grain-oriented steel in finite element analysis to predict the behaviour of the dipole magnets for this accelerator. It was found that including anisotropic material properties has a detrimental effect on model convergence. During this study it was not possible to include grain oriented steel with an accuracy necessary to study the field quality of a dipole magnet.

  3. Manufacturing process to reduce large grain growth in zirconium alloys

    DOE Patents [OSTI]

    Rosecrans, Peter M.

    1987-01-01

    A method of treating cold-worked zirconium alloys to reduce large grain gth during thermal treatment at temperatures above the recrystallization temperature of the alloy comprising heating the cold-worked alloy between about 1300.degree.-1350.degree. F. for 1 to 3 hours prior to treatment above its recrystallization temperature.

  4. Microwave sintering of sol-gel derived abrasive grain

    DOE Patents [OSTI]

    Plovnick, Ross; Celikkaya, Ahmet; Blake, Rodger D.

    1997-01-01

    A method is provided for making microwave-sintered, free flowing alpha alumina-based ceramic abrasive grain, under conditions effective to couple microwaves with calcined alpha alumina-based abrasive gain precursor and sinter it at a temperature of at least about 1150.degree. C.

  5. The Impact of Oil Consumption Mechanisms on Diesel Exhaust Particle Size

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

    Distributions and Detailed Exhaust Chemical Composition | Department of Energy Oil Consumption Mechanisms on Diesel Exhaust Particle Size Distributions and Detailed Exhaust Chemical Composition The Impact of Oil Consumption Mechanisms on Diesel Exhaust Particle Size Distributions and Detailed Exhaust Chemical Composition 2003 DEER Conference Presentation: University of Wisconsin-Madison 2003_deer_foster.pdf (1.18 MB) More Documents & Publications Mass Correlation of Engine Emissions with

  6. EIA - Coal Distribution

    Gasoline and Diesel Fuel Update (EIA)

    Annual Coal Distribution Report > Annual Coal Distribution Archives Annual Coal Distribution Archive Release Date: February 17, 2011 Next Release Date: December 2011 Domestic coal ...

  7. Computer simulation study of the structure of vacancies in grain boundaries

    SciTech Connect (OSTI)

    Brokman, A.; Bristowe, P.D.; Balluffi, R.W.

    1981-01-01

    The structure of vacancies in grain boundaries has been investigated by computer molecular statics employing pairwise potentials. In order to gain an impression of the vacancy structures which may occur generally, a number of variables was investigated including: metal type, boundary type, degree of lattice coincidence and choice of boundary site. In all cases the vacancies remained as distinguishable point defects in the relatively irregular boundary structures. However, it was found that the vacancy often induced relatively large atomic displacements in the core of the boundary. These displacements often occurred only in the direct vicinity of the vacancy, but in certain cases they were widely distributed in the boundary, sometimes at surprisingly large distances.

  8. Low Latency Messages on Distributed Memory Multiprocessors

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

    Rosing, Matt; Saltz, Joel

    1995-01-01

    This article describes many of the issues in developing an efficient interface for communication on distributed memory machines. Although the hardware component of message latency is less than 1 ws on many distributed memory machines, the software latency associated with sending and receiving typed messages is on the order of 50 μs. The reason for this imbalance is that the software interface does not match the hardware. By changing the interface to match the hardware more closely, applications with fine grained communication can be put on these machines. This article describes several tests performed and many of the issues involvedmore » in supporting low latency messages on distributed memory machines.« less

  9. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    ... International Soil Carbon Network (ISCN) International ... (NA-22) Office of River Protection (United States) Office ... boundaries, grain size distribution, grain morphology ...

  10. Ultrafast visualization of crystallization and grain growth in shock-compressed SiO2

    SciTech Connect (OSTI)

    Gleason, A. E.; Bolme, C. A.; Lee, H. J.; Nagler, B.; Galtier, E.; Milathianaki, D.; Hawreliak, J.; Kraus, R. G.; Eggert, J. H.; Fratanduono, D. E.; Collins, G. W.; Sandberg, R.; Yang, W.; Mao, W. L.

    2015-09-04

    Pressure- and temperature-induced phase transitions have been studied for more than a century but very little is known about the non-equilibrium processes by which the atoms rearrange. Shock compression generates a nearly instantaneous propagating high-pressure/temperature condition while in situ X-ray diffraction (XRD) probes the time-dependent atomic arrangement. Here we present in situ pump–probe XRD measurements on shock-compressed fused silica, revealing an amorphous to crystalline high-pressure stishovite phase transition. Using the size broadening of the diffraction peaks, the growth of nanocrystalline stishovite grains is resolved on the nanosecond timescale just after shock compression. At applied pressures above 18 GPa the nuclueation of stishovite appears to be kinetically limited to 1.4±0.4 ns. The functional form of this grain growth suggests homogeneous nucleation and attachment as the growth mechanism. As a result, these are the first observations of crystalline grain growth in the shock front between low- and high-pressure states via XRD.

  11. 2015 Distributed Wind Market Report Fact Sheet | Department of Energy

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

    Distributed Wind Market Report Fact Sheet 2015 Distributed Wind Market Report Fact Sheet 2015-Distributed-Wind-Market-Report-Fact-Sheet_Page_1.jpg Wind turbines in distributed applications are found in all 50 states, Puerto Rico, and the U.S. Virgin Islands to provide energy locally, either serving on-site electricity needs or a local grid. Distributed wind is defined by the wind project's location relative to end-use and powerdistribution infrastructure, rather than turbine or project size.

  12. Detecting rare, abnormally large grains by x-ray diffraction

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

    Detecting rare, abnormally large grains by x-ray diffraction - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Energy Defense

  13. Charge Transport Anisotropy Due to Grain Boundaries in Directionally

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

    Crystallized Thin Films of Regio-Regular Poly(3-hexylthiophene) Charge Transport Anisotropy Due to Grain Boundaries in Directionally Crystallized Thin Films of Regio-Regular Poly(3-hexylthiophene) Semicrystalline polymers, such as polythiophenes, hold much promise as active layers in printable electronic devices such as photovoltaic cells, sensors, and thin film transistors. As organic semiconductors approach commercialization, there is a need to better understand the relationship between

  14. Grain boundary energy in 5 degrees of freedom space

    Energy Science and Technology Software Center (OSTI)

    2012-09-21

    GB5DOF is a program written in MatLab for computing excess energy of an arbitrary grain boundary defined by its 5 geometrical degrees of freedom. The program is written in the form of a single self-contained function callable from within commercially available MatLab software package. The function takes a geometric description of the boundary and material identity as input parameters and returns the predicted boundary energy.

  15. Intergranular degradation assessment via random grain boundary network analysis

    DOE Patents [OSTI]

    Kumar, Mukul; Schwartz, Adam J.; King, Wayne E.

    2002-01-01

    A method is disclosed for determining the resistance of polycrystalline materials to intergranular degradation or failure (IGDF), by analyzing the random grain boundary network connectivity (RGBNC) microstructure. Analysis of the disruption of the RGBNC microstructure may be assess the effectiveness of materials processing in increasing IGDF resistance. Comparison of the RGBNC microstructures of materials exposed to extreme operating conditions to unexposed materials may be used to diagnose and predict possible onset of material failure due to

  16. Physics of grain boundaries in polycrystalline photovoltaic semiconductors

    SciTech Connect (OSTI)

    Yan, Yanfa Yin, Wan-Jian; Wu, Yelong; Shi, Tingting; Paudel, Naba R.; Li, Chen; Poplawsky, Jonathan; Wang, Zhiwei; Moseley, John; Guthrey, Harvey; Moutinho, Helio; Al-Jassim, Mowafak M.; Pennycook, Stephen J.

    2015-03-21

    Thin-film solar cells based on polycrystalline Cu(In,Ga)Se{sub 2} (CIGS) and CdTe photovoltaic semiconductors have reached remarkable laboratory efficiencies. It is surprising that these thin-film polycrystalline solar cells can reach such high efficiencies despite containing a high density of grain boundaries (GBs), which would seem likely to be nonradiative recombination centers for photo-generated carriers. In this paper, we review our atomistic theoretical understanding of the physics of grain boundaries in CIGS and CdTe absorbers. We show that intrinsic GBs with dislocation cores exhibit deep gap states in both CIGS and CdTe. However, in each solar cell device, the GBs can be chemically modified to improve their photovoltaic properties. In CIGS cells, GBs are found to be Cu-rich and contain O impurities. Density-functional theory calculations reveal that such chemical changes within GBs can remove most of the unwanted gap states. In CdTe cells, GBs are found to contain a high concentration of Cl atoms. Cl atoms donate electrons, creating n-type GBs between p-type CdTe grains, forming local p-n-p junctions along GBs. This leads to enhanced current collections. Therefore, chemical modification of GBs allows for high efficiency polycrystalline CIGS and CdTe thin-film solar cells.

  17. Drying grain using a hydrothermally treated liquid lignite fuel

    SciTech Connect (OSTI)

    Bukurov, Z.; Cvijanovic, P.; Bukurov, M.; Ljubicic, B.R.

    1995-12-01

    A shortage of domestic oil and natural gas resources in Yugoslavia, particularly for agricultural and industrial purposes, has motivated the authors to explore the possibility of using liquid lignite as an alternate fuel for drying grain. This paper presents a technical and economic assessment of the possibility of retrofitting grain-drying plants currently fueled by oil or natural gas to liquid lignite fuel. All estimates are based on lignite taken from the Kovin deposit. Proposed technology includes underwater mining techniques, aqueous ash removal, hydrothermal processing, solids concentration, pipeline transport up to 120 km, and liquid lignite direct combustion. For the characterization of Kovin lignite, standard ASTM procedures were used: proximate, ultimate, ash, heating value, and Theological analyses were performed. Results from an extensive economic analysis indicate a delivered cost of US$20/ton for the liquid lignite. For the 70 of the grain-drying plants in the province of Vojvodina, this would mean a total yearly saving of about US $2,500,000. The advantages of this concept are obvious: easy to transport and store, nonflammable, nonexplosive, nontoxic, 30%-40% cheaper than imported oil and gas, domestic fuel is at hand. The authors believe that liquid lignite, rather than an alternative, is becoming more and more an imperative.

  18. Entrainment of coarse grains using a discrete particle model

    SciTech Connect (OSTI)

    Valyrakis, Manousos; Arnold, Roger B. Jr.

    2014-10-06

    Conventional bedload transport models and incipient motion theories relying on a time-averaged boundary shear stress are incapable of accounting for the effects of fluctuating near-bed velocity in turbulent flow and are therefore prone to significant errors. Impulse, the product of an instantaneous force magnitude and its duration, has been recently proposed as an appropriate criterion for quantifying the effects of flow turbulence in removing coarse grains from the bed surface. Here, a discrete particle model (DPM) is used to examine the effects of impulse, representing a single idealized turbulent event, on particle entrainment. The results are classified according to the degree of grain movement into the following categories: motion prior to entrainment, initial dislodgement, and energetic displacement. The results indicate that in all three cases the degree of particle motion depends on both the force magnitude and the duration of its application and suggest that the effects of turbulence must be adequately accounted for in order to develop a more accurate method of determining incipient motion. DPM is capable of simulating the dynamics of grain entrainment and is an appropriate tool for further study of the fundamental mechanisms of sediment transport.

  19. Ion beam-induced amorphous-to-tetragonal phase transformation and grain growth of nanocrystalline zirconia

    SciTech Connect (OSTI)

    Lian, Jie; Zhang, Jiaming; Namavar, Fereydoon; Zhang, Yanwen; Lu, Fengyuan; Haider, Hani; Garvin, Kevin; Weber, William J.; Ewing, Rodney C.

    2009-05-26

    Nanocrystalline zirconia has recently attracted extensive research interest due to its unique mechanical, thermal and electrical properties as compared to bulk zirconia counterparts, and it is of particular importance to control the phase stability of different polymorphs (amorphous, cubic, tetragonal and monoclinic phases) at different size regimes. In this paper, we performed ion beam bombardments on bilayers (amorphous and cubic) of pure nano-zirconia using 1 MeV Kr2+ irradiation. Transmission electron microscopy (TEM) analysis reveals that amorphous zirconia transforms to a tetragonal structure under irradiation at room temperature, suggesting that the tetragonal phase is more energetically favorable under these conditions. The final grain size of the tetragonal zirconia can be controlled by irradiation conditions. The irradiation-induced nanograins of tetragonal ZrO2 are stable at ambient conditions and maintain their physical integrity over a long period of time after irradiation. These results demonstrated that ion-beam modification methods provide the means to control the phase stability and structure of zirconia polymorphs.

  20. Assessment of local deformation using EBSD: Quantification of local damage at grain boundaries

    SciTech Connect (OSTI)

    Kamaya, Masayuki

    2012-04-15

    Electron backscatter diffraction (EBSD) in conjunction with scanning electron microscopy was used to assess localization of the local misorientation to grain boundary. In order to quantify the degree of localization, a parameter, which was referred to as the grain boundary local misorientation, was proposed. Through crystal orientation measurements using deformed Type 316 stainless steel, it was shown that the grain boundary local misorientation increased with the applied plastic strain. Particularly, at several grain boundaries, the grain boundary local misorientation was more than 3 times the local misorientation averaged for the whole area. Surface observations revealed that the large local misorientation near the grain boundaries was attributed to the impeded slip steps rather than the number of slip steps observed on the surface. The magnitude of the grain boundary local misorientation had a week correlation with grain boundary length or grain boundary misorientation, and no correlation was found for twin boundaries. Finally, it was shown that the maximum grain boundary local misorientation could be estimated statistically, and the estimated maximum value for the specimen surface with an area of 80 mm{sup 2} was 10.6 times the averaged value. - Highlights: Black-Right-Pointing-Pointer The grain boundary local misorientation was proposed. Black-Right-Pointing-Pointer The maximum grain boundary local misorientation could be estimated statistically. Black-Right-Pointing-Pointer The large local misorientation was attributed to the impeded slip steps.

  1. GASIFICATION FOR DISTRIBUTED GENERATION

    SciTech Connect (OSTI)

    Ronald C. Timpe; Michael D. Mann; Darren D. Schmidt

    2000-05-01

    evaluated through reactivity and product composition were carried out on thermogravimetric analysis (TGA) equipment. These tests were evaluated and then followed by bench-scale studies at 1123 K using an integrated bench-scale fluidized-bed gasifier (IBG) which can be operated in the semicontinuous batch mode. Products from tests were solid (ash), liquid (tar), and gas. Tar was separated on an open chromatographic column. Analysis of the gas product was carried out using on-line Fourier transform infrared spectroscopy (FT-IR). For selected tests, gas was collected periodically and analyzed using a refinery gas analyzer GC (gas chromatograph). The solid product was not extensively analyzed. This report is a part of a search into emerging gasification technologies that can provide power under 30 MW in a distributed generation setting. Larger-scale gasification has been used commercially for more than 50 years to produce clean synthesis gas for the refining, chemical, and power industries, and it is probable that scaled-down applications for use in remote areas will become viable. The appendix to this report contains a list, description, and sources of currently available gasification technologies that could be or are being commercially applied for distributed generation. This list was gathered from current sources and provides information about the supplier, the relative size range, and the status of the technology.

  2. Ellipsometry characterization of polycrystalline ZnO layers with the modeling of carrier concentration gradient: Effects of grain boundary, humidity, and surface texture

    SciTech Connect (OSTI)

    Sago, Keisuke; Fujiwara, Hiroyuki; Kuramochi, Hideto; Iigusa, Hitoshi; Utsumi, Kentaro

    2014-04-07

    Spectroscopic ellipsometry (SE) has been applied to study the effects of grain boundary, humidity, and surface texture on the carrier transport properties of Al-doped ZnO layers fabricated by dc and rf magnetron sputtering. In the SE analysis, the variation in the free carrier absorption toward the growth direction, induced by the ZnO grain growth on foreign substrates, has been modeled explicitly by adopting a multilayer model in which the optical carrier concentration (N{sub opt}) varies continuously with a constant optical mobility (?{sub opt}). The effect of the grain boundary has been studied by comparing ?{sub opt} with Hall mobility (?{sub Hall}). The change in ?{sub Hall}/?{sub opt} indicates a sharp structural transition of the ZnO polycrystalline layer at a thickness of d???500?nm, which correlates very well with the structure confirmed by transmission electron microscopy. In particular, below the transition thickness, the formation of the high density grain boundary leads to the reduction in the ?{sub Hall}/?{sub opt} ratio as well as N{sub opt}. As a result, we find that the thickness dependence of the carrier transport properties is almost completely governed by the grain boundary formation. On the other hand, when the ZnO layer is exposed to wet air at 85?C, ?{sub Hall} reduces drastically with a minor variation of ?{sub opt} due to the enhanced grain boundary scattering. We have also characterized textured ZnO:Al layers prepared by HCl wet etching by SE. The analysis revealed that the near-surface carrier concentration increases slightly after the etching. We demonstrate that the SE technique can be applied to distinguish various rough textured structures (size???1??m) of the ZnO layers prepared by the HCl etching.

  3. Ablation of high-Z material dust grains in edge plasmas of magnetic fusion devices

    SciTech Connect (OSTI)

    Marenkov, E. D.; Krasheninnikov, S. I.

    2014-12-15

    The model, including shielding effects of high-Z dust grain ablation in tokamak edge plasma, is presented. In a contrast to shielding models developed for pellets ablation in a hot plasma core, this model deals with the dust grain ablation in relatively cold edge plasma. Using some simplifications, a closed set of equations determining the grain ablation rate Γ is derived and analyzed both analytically and numerically. The scaling law for Γ versus grain radius and ambient plasma parameters is obtained and confirmed by the results of numerical solutions. The results obtained are compared with both dust grain models containing no shielding effects and the pellet ablation models.

  4. Metal oxide porous ceramic membranes with small pore sizes

    DOE Patents [OSTI]

    Anderson, Marc A.; Xu, Qunyin

    1991-01-01

    A method is disclosed for the production of metal oxide ceramic membranes of very small pore size. The process is particularly useful in the creation of titanium and other transition metal oxide membranes. The method utilizes a sol-gel process in which the rate of particle formation is controlled by substituting a relatively large alcohol in the metal alkoxide and by limiting the available water. Stable, transparent metal oxide ceramic membranes are created having a narrow distribution of pore size, with the pore diameter being manipulable in the range of 5 to 40 Angstroms.

  5. Metal oxide porous ceramic membranes with small pore sizes

    DOE Patents [OSTI]

    Anderson, Marc A.; Xu, Qunyin

    1992-01-01

    A method is disclosed for the production of metal oxide ceramic membranes of very small pore size. The process is particularly useful in the creation of titanium and other transition metal oxide membranes. The method utilizes a sol-gel process in which the rate of particle formation is controlled by substituting a relatively large alcohol in the metal alkoxide and by limiting the available water. Stable, transparent metal oxide ceramic membranes are created having a narrow distribution of pore size, with the pore diameter being manipulable in the range of 5 to 40 Angstroms.

  6. Size exclusion deep bed filtration: Experimental and modelling uncertainties

    SciTech Connect (OSTI)

    Badalyan, Alexander You, Zhenjiang; Aji, Kaiser; Bedrikovetsky, Pavel; Carageorgos, Themis; Zeinijahromi, Abbas

    2014-01-15

    A detailed uncertainty analysis associated with carboxyl-modified latex particle capture in glass bead-formed porous media enabled verification of the two theoretical stochastic models for prediction of particle retention due to size exclusion. At the beginning of this analysis it is established that size exclusion is a dominant particle capture mechanism in the present study: calculated significant repulsive Derjaguin-Landau-Verwey-Overbeek potential between latex particles and glass beads is an indication of their mutual repulsion, thus, fulfilling the necessary condition for size exclusion. Applying linear uncertainty propagation method in the form of truncated Taylor's series expansion, combined standard uncertainties (CSUs) in normalised suspended particle concentrations are calculated using CSUs in experimentally determined parameters such as: an inlet volumetric flowrate of suspension, particle number in suspensions, particle concentrations in inlet and outlet streams, particle and pore throat size distributions. Weathering of glass beads in high alkaline solutions does not appreciably change particle size distribution, and, therefore, is not considered as an additional contributor to the weighted mean particle radius and corresponded weighted mean standard deviation. Weighted mean particle radius and LogNormal mean pore throat radius are characterised by the highest CSUs among all experimental parameters translating to high CSU in the jamming ratio factor (dimensionless particle size). Normalised suspended particle concentrations calculated via two theoretical models are characterised by higher CSUs than those for experimental data. The model accounting the fraction of inaccessible flow as a function of latex particle radius excellently predicts normalised suspended particle concentrations for the whole range of jamming ratios. The presented uncertainty analysis can be also used for comparison of intra- and inter-laboratory particle size exclusion data.

  7. The influence of temperature and grain boundary volume on the resistivity of nanocrystalline nickel

    SciTech Connect (OSTI)

    Darnbrough, J. E. Flewitt, P. E. J.; Roebuck, B.

    2015-11-14

    The thermal stability and modes of recrystallisation of nanocrystalline nickel has been observed through a conduction-based non-destructive test. Resistivity measurements have been utilised to quantify grain boundary volume fraction and microstructure. This observation makes clear the distinction of the factors that contribute to resistivity and demonstrates that these contributions are related to microstructure, either directly or in-directly. In static systems, the contribution of ordered grains and low-order grain boundary atomic arrangements in small grained material has been measured and correlated with resistivity. Measurements of in-situ resistivity conducted at high temperature gives changes with time which are related to grain growth, during heat treatment. This shows that resistivity can be used as a technique for observing the microstructure and grain growth of small grained material.

  8. Low temperature production of large-grain polycrystalline semiconductors

    DOE Patents [OSTI]

    Naseem, Hameed A.; Albarghouti, Marwan

    2007-04-10

    An oxide or nitride layer is provided on an amorphous semiconductor layer prior to performing metal-induced crystallization of the semiconductor layer. The oxide or nitride layer facilitates conversion of the amorphous material into large grain polycrystalline material. Hence, a native silicon dioxide layer provided on hydrogenated amorphous silicon (a-Si:H), followed by deposited Al permits induced crystallization at temperatures far below the solid phase crystallization temperature of a-Si. Solar cells and thin film transistors can be prepared using this method.

  9. Model of evolution of surface grain structure under ion bombardment

    SciTech Connect (OSTI)

    Knyazeva, Anna G.; Kryukova, Olga N.

    2014-11-14

    Diffusion and chemical reactions in multicomponent systems play an important role in numerous technology applications. For example, surface treatment of materials and coatings by particle beam leads to chemical composition and grain structure change. To investigate the thermal-diffusion and chemical processes affecting the evolution of surface structure, the mathematical modeling is efficient addition to experiment. In this paper two-dimensional model is discussed to describe the evolution of titanium nitride coating on the iron substrate under implantation of boron and carbon. The equation for diffusion fluxes and reaction rate are obtained using Gibbs energy expansion into series with respect to concentration and their gradients.

  10. Comparing liquid fuel costs: grain alcohol versus sunflower oil

    SciTech Connect (OSTI)

    Reining, R.C.; Tyner, W.E.

    1983-08-01

    This paper compares the technical and economic feasibility of small-scale production of fuel grade grain alcohol with sunflower oil. Three scales of ethanol and sunflower oil production are modeled, and sensitivity analysis is conducted for various operating conditions and costs. The general conclusion is that sunflower oil costs less to produce than alcohol. Government subsidies for alcohol, but not sunflower oil, could cause adoption of more expensive alcohol in place of cheaper sunflower oil. However, neither sunflower oil nor alcohol are competitive with diesel fuel. 7 references.

  11. Small-angle neutron scattering measurement of deuterium trapping at dislocations and grain boundaries in palladium

    SciTech Connect (OSTI)

    Heuser, B.J.

    1991-01-01

    Small angle neutron scattering measurements have been performed on deformed single and polycrystalline palladium with and without deuterium dissolved in the solution phase at room temperature. The purpose of these experiments was to directly measure the spatial distribution of trapped deuterium at dislocations in the deformed metal. The net scattering cross section for the same smaple with and without deuterium shows a behavior expected from deuterium correlation with dislocations froming rod-like scattering structures. The measured cross sections indicate the trapped deuterium is within 2 to 3 Burgers vectors of the dislocation core. On average 1 to 3 deuterons per {angstrom} are trapped at the dislocations in the deformed samples. The measurements also indicate the straight, rod-like correlation geometry extends on average 50 to 100 {angstrom} along the dislocations. Dislocation densities on the order of 5 {times} 10{sup 11} cm/cm{sup 3} were found for all samples investigated. Net scattering from a well annealed polycrystalline palladium sample exhibiting a behavior expected from spherical shells has been observed. This net scattering is attributed to deuterium trapping at grain boundaries in the polycrystalline sample. net scattering in excess of that expected from deuterium correlated at dislocations was also observed in a deformed polycrystalline measurement. This too is attributed to deuterium trapping at grain boundaries. The dislocation substructure of the deformed palladium samples was characterized by transmission electron microscopy (TEM). This analysis illustrated the cellular arrangement that evolved in palladium during cold working. The presence of MnO particles also was confirmed by TEM analysis.

  12. MIXING AND TRANSPORT OF SHORT-LIVED AND STABLE ISOTOPES AND REFRACTORY GRAINS IN PROTOPLANETARY DISKS

    SciTech Connect (OSTI)

    Boss, Alan P.

    2013-08-10

    Analyses of primitive meteorites and cometary samples have shown that the solar nebula must have experienced a phase of large-scale outward transport of small refractory grains as well as homogenization of initially spatially heterogeneous short-lived isotopes. The stable oxygen isotopes, however, were able to remain spatially heterogeneous at the {approx}6% level. One promising mechanism for achieving these disparate goals is the mixing and transport associated with a marginally gravitationally unstable (MGU) disk, a likely cause of FU Orionis events in young low-mass stars. Several new sets of MGU models are presented that explore mixing and transport in disks with varied masses (0.016 to 0.13 M{sub Sun }) around stars with varied masses (0.1 to 1 M{sub Sun }) and varied initial Q stability minima (1.8 to 3.1). The results show that MGU disks are able to rapidly (within {approx}10{sup 4} yr) achieve large-scale transport and homogenization of initially spatially heterogeneous distributions of disk grains or gas. In addition, the models show that while single-shot injection heterogeneity is reduced to a relatively low level ({approx}1%), as required for early solar system chronometry, continuous injection of the sort associated with the generation of stable oxygen isotope fractionations by UV photolysis leads to a sustained, relatively high level ({approx}10%) of heterogeneity, in agreement with the oxygen isotope data. These models support the suggestion that the protosun may have experienced at least one FU Orionis-like outburst, which produced several of the signatures left behind in primitive chondrites and comets.

  13. Real-Space Distributions of Electrical Potential in Planar and Porous Peroveskite Solar Cells: Carrier Separation and Transport

    SciTech Connect (OSTI)

    Jiang, Chun-Sheng; Yang, Mengjin; Zhou, Yuanyuan; To, Bobby; Nanayakkara, Sanjini; Luther, Joseph; Zhou, Weilie; Berry, Joseph J.; Van de Lagemaat, Jao; Padture, Nitin P.; Zhu, Kai; Al-Jassim, Mowafak M.

    2015-06-14

    We study the carrier transport and separation in planar and porous PS devices, which is one of the most fundamental operation mechanisms of solar cells, by profiling the electrical potential across the devices. We found that the PV devices work by p-n junction at the TiO2/PS interface for the both device structures. Combining the potential profiling results with the solar cell performance parameters taken on the optimized and thickened devices, we found that mobility is the main factor limiting the device performance. Improving the mobility both within grains and across grain boundaries (or enlarging the grain size) are expected to significantly improve the device efficiency.

  14. Distribution Grid Integration

    Broader source: Energy.gov [DOE]

    The DOE Systems Integration team funds distribution grid integration research and development (R&D) activities to address the technical issues that surround distribution grid planning,...

  15. Annual Coal Distribution Report

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

    Annual Coal Distribution Report Release Date: April 16, 2015 | Next Release Date: March 2016 | full report | RevisionCorrection Revision to the Annual Coal Distribution Report ...

  16. About Industrial Distributed Energy

    Broader source: Energy.gov [DOE]

    The Advanced Manufacturing Office's (AMO's) Industrial Distributed Energy activities build on the success of predecessor DOE programs on distributed energy and combined heat and power (CHP) while...

  17. Coal Distribution Database, 2006

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

    Domestic Distribution of U.S. Coal by Origin State, Consumer, Destination and Method of Transportation, 2009 Final February 2011 2 Overview of 2009 Coal Distribution Tables...

  18. Three-body interactions in complex fluids: Virial coefficients from simulation finite-size effects

    SciTech Connect (OSTI)

    Ashton, Douglas J.; Wilding, Nigel B.

    2014-06-28

    A simulation technique is described for quantifying the contribution of three-body interactions to the thermodynamical properties of coarse-grained representations of complex fluids. The method is based on a new approach for determining virial coefficients from the measured volume-dependent asymptote of a certain structural function. By comparing the third virial coefficient B{sub 3} for a complex fluid with that of an approximate coarse-grained model described by a pair potential, three body effects can be quantified. The strategy is applicable to both Molecular Dynamics and Monte Carlo simulation. Its utility is illustrated via measurements of three-body effects in models of star polymers and in highly size-asymmetrical colloid-polymer mixtures.

  19. Integrated Transmission and Distribution Control

    SciTech Connect (OSTI)

    Kalsi, Karanjit; Fuller, Jason C.; Tuffner, Francis K.; Lian, Jianming; Zhang, Wei; Marinovici, Laurentiu D.; Fisher, Andrew R.; Chassin, Forrest S.; Hauer, Matthew L.

    2013-01-16

    Distributed, generation, demand response, distributed storage, smart appliances, electric vehicles and renewable energy resources are expected to play a key part in the transformation of the American power system. Control, coordination and compensation of these smart grid assets are inherently interlinked. Advanced control strategies to warrant large-scale penetration of distributed smart grid assets do not currently exist. While many of the smart grid technologies proposed involve assets being deployed at the distribution level, most of the significant benefits accrue at the transmission level. The development of advanced smart grid simulation tools, such as GridLAB-D, has led to a dramatic improvement in the models of smart grid assets available for design and evaluation of smart grid technology. However, one of the main challenges to quantifying the benefits of smart grid assets at the transmission level is the lack of tools and framework for integrating transmission and distribution technologies into a single simulation environment. Furthermore, given the size and complexity of the distribution system, it is crucial to be able to represent the behavior of distributed smart grid assets using reduced-order controllable models and to analyze their impacts on the bulk power system in terms of stability and reliability. The objectives of the project were to: • Develop a simulation environment for integrating transmission and distribution control, • Construct reduced-order controllable models for smart grid assets at the distribution level, • Design and validate closed-loop control strategies for distributed smart grid assets, and • Demonstrate impact of integrating thousands of smart grid assets under closed-loop control demand response strategies on the transmission system. More specifically, GridLAB-D, a distribution system tool, and PowerWorld, a transmission planning tool, are integrated into a single simulation environment. The integrated environment

  20. Annual Coal Distribution

    Reports and Publications (EIA)

    2016-01-01

    The Annual Coal Distribution Report (ACDR) provides detailed information on domestic coal distribution by origin state, destination state, consumer category, and method of transportation. Also provided is a summary of foreign coal distribution by coal-producing state. All data for the report year are final and this report supersedes all data in the quarterly distribution reports.

  1. Annual Coal Distribution

    Reports and Publications (EIA)

    2015-01-01

    The Annual Coal Distribution Report (ACDR) provides detailed information on domestic coal distribution by origin state, destination state, consumer category, and method of transportation. Also provided is a summary of foreign coal distribution by coal-producing state. All data for the report year are final and this report supersedes all data in the quarterly distribution reports.

  2. Investigation of the Distribution of Fission Products Silver, Palladium and Cadmium in Neutron Irradiated SIC using a Cs Corrected HRTEM

    SciTech Connect (OSTI)

    I. J. van Rooyen; E. Olivier; J. H Neethlin

    2014-10-01

    Electron microscopy examinations of selected coated particles from the first advanced gas reactor experiment (AGR-1) at Idaho National Laboratory (INL) provided important information on fission product distribution and chemical composition. Furthermore, recent research using STEM analysis led to the discovery of Ag at SiC grain boundaries and triple junctions. As these Ag precipitates were nano-sized, high resolution transmission electron microscopy (HRTEM) examination was used to provide more information at the atomic level. This paper describes some of the first HRTEM results obtained by examining a particle from Compact 4-1-1, which was irradiated to an average burnup of 19.26% fissions per initial metal atom (FIMA), a time average, volume-averaged temperature of 1072°C; a time average, peak temperature of 1182°C and an average fast fluence of 4.13 x 1021 n/cm2. Based on gamma analysis, it is estimated that this particle may have released as much as 10% of its available Ag-110m inventory during irradiation. The HRTEM investigation focused on Ag, Pd, Cd and U due to the interest in Ag transport mechanisms and possible correlation with Pd, Ag and U previously found. Additionally, Compact 4-1-1 contains fuel particles fabricated with a different fuel carrier gas composition and lower deposition temperatures for the SiC layer relative to the Baseline fabrication conditions, which are expected to reduce the concentration of SiC defects resulting from uranium dispersion. Pd, Ag, and Cd were found to co-exist in some of the SiC grain boundaries and triple junctions whilst U was found to be present in the micron-sized precipitates as well as separately in selected areas at grain boundaries. This study confirmed the presence of Pd both at inter- and intragranular positions; in the latter case specifically at stacking faults. Small Pd nodules were observed at a distance of about 6.5 micron from the inner PyC/SiC interface.

  3. Distributed Wind Ordinances: Slides

    Wind Powering America (EERE)

    an introduction to distributed wind projects and a brief overview of topics to consider when developing a distributed wind energy ordinance. Distributed Wind Ordinances Photo from Byers and Renier Construction, NREL 18820 Distributed Wind Ordinances The U.S. Department of Energy defines distributed wind projects as: (a) The use of wind turbines, on- or off-grid, at homes, farms and ranches, businesses, public and industrial facilities, or other sites to offset all or a portion of the local

  4. EIA -Quarterly Coal Distribution

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

    - Coal Distribution Quarterly Coal Distribution Archives Release Date: August 17, 2016 Next Release Date: December 22, 2016 The Quarterly Coal Distribution Report (QCDR) provides detailed quarterly data on U.S. domestic coal distribution by coal origin, coal destination, mode of transportation and consuming sector. All data are preliminary and superseded by the final Coal Distribution - Annual Report. Year/Quarters By origin State By destination State Report Data File Report Data File 2009

  5. AB INITIO STUDY OF GRAIN BOUNDARY PROPERTIES OF TUNGSTEN ALLOYS

    SciTech Connect (OSTI)

    Setyawan, Wahyu; Kurtz, Richard J.

    2012-04-17

    Density functional theory was employed to investigate the grain boundary (GB) property of W-TM alloys (TM: fifth and sixth row transition metals). GB strengthening was found for Hf, Ta, Nb, Ru, Re, Os and Ir for 27{l_brace}525{r_brace} and to a lesser degree for 11{l_brace}323{r_brace}. Lower valence solutes strengthen the GB at certain substitutional sites, while higher valence elements enforce it at other positions. For 3{l_brace}112{r_brace}, the alloys exhibit reduced cleavage energies. Hence, allowing with TMs increases the GB cohesion more effectively for large-angle GBs whose cleavage energy is, in general, inherently lower than the low-angle ones. Electron density analysis elucidates the mechanism of charge addition or depletion of the GB bonding region upon TM substitution at various positions leading to stronger or weaker intergranular cohesion, respectively.

  6. GRAIN-SCALE FAILURE IN THERMAL SPALLATION DRILLING

    SciTech Connect (OSTI)

    Walsh, S C; Lomov, I; Roberts, J J

    2012-01-19

    Geothermal power promises clean, renewable, reliable and potentially widely-available energy, but is limited by high initial capital costs. New drilling technologies are required to make geothermal power financially competitive with other energy sources. One potential solution is offered by Thermal Spallation Drilling (TSD) - a novel drilling technique in which small particles (spalls) are released from the rock surface by rapid heating. While TSD has the potential to improve drilling rates of brittle granitic rocks, the coupled thermomechanical processes involved in TSD are poorly described, making system control and optimization difficult for this drilling technology. In this paper, we discuss results from a new modeling effort investigating thermal spallation drilling. In particular, we describe an explicit model that simulates the grain-scale mechanics of thermal spallation and use this model to examine existing theories concerning spalling mechanisms. We will report how borehole conditions influence spall production, and discuss implications for macro-scale models of drilling systems.

  7. Evolution of microstructure, texture and inhibitor along the processing route for grain-oriented electrical steels using strip casting

    SciTech Connect (OSTI)

    Liu, Hai-Tao; Yao, Sheng-Jie; Sun, Yu; Gao, Fei; Song, Hong-Yu; Liu, Guo-Huai; Li, Lei; Geng, Dian-Qiao; Liu, Zhen-Yu; Wang, Guo-Dong

    2015-08-15

    In the present work, a regular grade GO sheet was produced successively by strip casting, hot rolling, normalizing annealing, two-stage cold rolling with intermediate annealing, primary recrystallization annealing, secondary recrystallization annealing and purification. The aim of this paper was to characterize the evolution of microstructure, texture and inhibitor along the new processing route by comprehensive utilization of optical microscopy, X-ray diffraction and transmission electron microscopy. It was found that a fine microstructure with the ferrite grain size range of 7–12 μm could be obtained in the primary recrystallization annealed sheet though a very coarse microstructure was produced in the initial as-cast strip. The main finding was that the “texture memory” effect on Goss texture started on the through-thickness intermediate annealed strip after first cold rolling, which was not similar to the “texture memory” effect on Goss texture starting on the surface layers of the hot rolled strip in the conventional production route. As a result, the origin of Goss nuclei capable of secondary recrystallization lied in the grains already presented in Goss orientation in the intermediate annealed strip after first cold rolling. Another finding was that fine and dispersive inhibitors (mainly AlN) were easy to be produced in the primary recrystallization microstructure due to the initial rapid solidification during strip casting and the subsequent rapid cooling, and the very high temperature reheating usually used before hot rolling in the conventional production route could be avoided. - Highlights: • A regular grade grain-oriented electrical steel was produced. • Evolution of microstructure, texture and inhibitor was characterized. • Origin of Goss nuclei lied in the intermediate annealed strip. • A fine primary recrystallization microstructure could be produced. • Effective inhibitors were easy to be obtained in the new processing route.

  8. Rapid Thermal Annealing of HWCVD a-Si:H Films: The Effect of the Film Hydrogen Content on the Crystallization Kinetics, Surface Morphology, and Grain Growth

    SciTech Connect (OSTI)

    Mahan, A. H.; Reedy, R. C. Jr.; Ginley, D. S.; Roy, B.; Readey, D. W.

    2005-11-01

    We report the effect of the hydrogen (H) content (CH) on the crystallization kinetics, surface morphology and grain growth for Hot Wire CVD a-Si:H films containing 12.5 and 2.7 at.% H which are crystallized by rapid thermal anneal (RTA). For the high CH film we observe explosive H evolution, with a resultant destruction of the film for RTA temperatures >750 deg C. At RTA temperatures ~600 deg C, both films remain intact with similar morphologies. At this same lower RTA, the incubation and crystallization times decrease, and the grain size as measured by X-Ray Diffraction increases with decreasing film CH. SIMS measurements indicate that a similar film CH (<0.5 at.%) exists in both films when crystallization commences. The benefits of a two-step annealing process for the high CH film are documented.

  9. The growth mechanism of grain boundary carbide in Alloy 690

    SciTech Connect (OSTI)

    Li, Hui; Xia, Shuang; Zhou, Bangxin; Peng, Jianchao

    2013-07-15

    The growth mechanism of grain boundary M{sub 23}C{sub 6} carbides in nickel base Alloy 690 after aging at 715 °C was investigated by high resolution transmission electron microscopy. The grain boundary carbides have coherent orientation relationship with only one side of the matrix. The incoherent phase interface between M{sub 23}C{sub 6} and matrix was curved, and did not lie on any specific crystal plane. The M{sub 23}C{sub 6} carbide transforms from the matrix phase directly at the incoherent interface. The flat coherent phase interface generally lies on low index crystal planes, such as (011) and (111) planes. The M{sub 23}C{sub 6} carbide transforms from a transition phase found at curved coherent phase interface. The transition phase has a complex hexagonal crystal structure, and has coherent orientation relationship with matrix and M{sub 23}C{sub 6}: (111){sub matrix}//(0001){sub transition}//(111){sub carbide}, <112{sup ¯}>{sub matrix}//<21{sup ¯}10>{sub transition}//<112{sup ¯}>{sub carbide}. The crystal lattice constants of transition phase are c{sub transition}=√(3)×a{sub matrix} and a{sub transition}=√(6)/2×a{sub matrix}. Based on the experimental results, the growth mechanism of M{sub 23}C{sub 6} and the formation mechanism of transition phase are discussed. - Highlights: • A transition phase was observed at the coherent interfaces of M{sub 23}C{sub 6} and matrix. • The transition phase has hexagonal structure, and is coherent with matrix and M{sub 23}C{sub 6}. • The M{sub 23}C{sub 6} transforms from the matrix directly at the incoherent phase interface.

  10. 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.

  11. 2012 Market Report on Wind Technologies in Distributed Applications

    SciTech Connect (OSTI)

    Orrell, Alice C.

    2013-08-01

    An annual report on U.S. wind power in distributed applications – expanded to include small, mid-size, and utility-scale installations – including key statistics, economic data, installation, capacity, and generation statistics, and more.

  12. Sandia Energy - Distribution Grid Integration

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

    Distribution Grid Integration Home Stationary Power Energy Conversion Efficiency Solar Energy Photovoltaics Grid Integration Distribution Grid Integration Distribution Grid...

  13. Grain Boundary Percolation Modeling of Fission Gas Release in Oxide Fuels

    SciTech Connect (OSTI)

    Paul C. Millett; Michael R. Tonks; S. B. Biner

    2012-05-01

    We present a new approach to fission gas release modeling in oxide fuels based on grain boundary network percolation. The method accounts for variability in the bubble growth and coalescence rates on individual grain boundaries, and the resulting effect on macroscopic fission gas release. Two-dimensional representa- tions of fuel pellet microstructures are considered, and the resulting gas release rates are compared with traditional two-stage Booth models, which do not account for long-range percolation on grain boundary net- works. The results show that the requirement of percolation of saturated grain boundaries can considerably reduce the total gas release rates, particularly when gas resolution is considered.

  14. A fast grain-growth mechanism revealed in nanocrystalline ceramic-oxides

    SciTech Connect (OSTI)

    Aidhy, Dilpuneet S; Zhang, Yanwen; Weber, William J

    2014-01-01

    Grain growth problem in nanocrystalline ceramic-oxides renders their highly attractive properties practically unusable due to limited understanding on the underlying grain growth mechanisms. Two conventional 'slow' grain-growth mechanisms, i.e., curvature-driven and grainrotation driven, are shown to be thermally active, and the discovery of a 'fast' disorder-driven mechanism is revealed using molecular dynamics simulation on nanocrystalline ceria, in conjunction with experimental observations. We elucidate that this disorder mechanism drives the unexpected fast grain growth observed experimentally during synthesis and irradiation conditions.

  15. Pore and grain boundary migration under a temperature gradient: A phase-field model study

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

    Biner, S. B.

    2016-03-16

    In this study, the collective migration behavior of pores and grain boundaries under a temperature gradient is studied for simple single crystal, bi-crystal and polycrystal configurations with a phase-field model formulism. For simulation of the microstructure of solids, composed of pores and grain boundaries, the results indicate that not only the volume fraction of pores, but also its spatial partitioning between the grain boundary junctions and the grain boundary segments appears to be important. In addition to various physical properties, the evolution kinetics, under given temperature gradients, will be strongly influenced with the initial morphology of a poly-crystalline microstructure.

  16. Grain boundary chemistry effects on environment-induced crack growth of iron-based alloys

    SciTech Connect (OSTI)

    Jones, R.H.

    1992-11-01

    Relation between grain boundary chemistry and environment-induced crack growth of Fe-based alloys is reviewed. The importance of the cleanliness of steels is clearly demonstrated by direct relations between grain boundary chemistry and crack growth behavior for both H and anodic dissolution-induced crack growth. Relationships between strain to failure, work of fracture, K[sub ISCC], crack velocity and fracture mode and grain boundary chemistry are presented. Only results in which the grain boundary chemistry has been measured directly by Auger electron spectroscopy (AES) on intergranular surfaces exposed by in situ fracture have been considered in this review.

  17. Grain boundary chemistry effects on environment-induced crack growth of iron-based alloys

    SciTech Connect (OSTI)

    Jones, R.H.

    1992-11-01

    Relation between grain boundary chemistry and environment-induced crack growth of Fe-based alloys is reviewed. The importance of the cleanliness of steels is clearly demonstrated by direct relations between grain boundary chemistry and crack growth behavior for both H and anodic dissolution-induced crack growth. Relationships between strain to failure, work of fracture, K{sub ISCC}, crack velocity and fracture mode and grain boundary chemistry are presented. Only results in which the grain boundary chemistry has been measured directly by Auger electron spectroscopy (AES) on intergranular surfaces exposed by in situ fracture have been considered in this review.

  18. Top 10 Things You Didn't Know About Distributed Wind Power |...

    Energy Savers [EERE]

    by households, schools, farms, industrial facilities and municipalities, distributed wind doesn't only refer to small-scale turbines; it includes any size turbine or array of...

  19. Phase-retrieval X-ray microscopy by Wigner-distribution deconvolution

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Chapman, Henry, N.

    2014-10-30

    64x64 scan of a group of latex spheres with 45 nm step size, used for demonstrating Wigner-distribution deconvolution.

  20. A new model of cloud drop distribution that simulates the observed...

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

    Michael Michigan Technological University Wiscombe, Warren BNLNASA Goddard Space Flight Center Category: Modeling Cloud droplet size distribution is one of the most fundamental...

  1. Giant strain with ultra-low hysteresis and high temperature stability in grain oriented lead-free K₀̣₅Bi₀̣₅TiO₃-BaTiO₃-Na₀̣₅Bi₀̣₅TiO₃ piezoelectric materials

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

    Maurya, Deepam; Zhou, Yuan; Wang, Yaojin; Yan, Yongke; Li, Jiefang; Viehland, Dwight; Priya, Shashank

    2015-02-26

    We synthesized grain-oriented lead-free piezoelectric materials in (K₀̣₅Bi₀̣₅TiO₃-BaTiO₃-xNa₀̣₅Bi₀̣₅TiO₃ (KBT-BT-NBT) system with high degree of texturing along the [001]c (c-cubic) crystallographic orientation. We demonstrate giant field induced strain (~0.48%) with an ultra-low hysteresis along with enhanced piezoelectric response (d₃₃ ~ 190pC/N) and high temperature stability (~160°C). Transmission electron microscopy (TEM) and piezoresponse force microscopy (PFM) results demonstrate smaller size highly ordered domain structure in grain-oriented specimen relative to the conventional polycrystalline ceramics. The grain oriented specimens exhibited a high degree of non-180° domain switching, in comparison to the randomly axed ones. These results indicate the effective solution to the lead-free piezoelectricmore » materials.« less

  2. Giant strain with ultra-low hysteresis and high temperature stability in grain oriented lead-free K???Bi???TiO?-BaTiO?-Na???Bi???TiO? piezoelectric materials

    SciTech Connect (OSTI)

    Maurya, Deepam; Zhou, Yuan; Wang, Yaojin; Yan, Yongke; Li, Jiefang; Viehland, Dwight; Priya, Shashank

    2015-02-26

    We synthesized grain-oriented lead-free piezoelectric materials in (K???Bi???TiO?-BaTiO?-xNa???Bi???TiO? (KBT-BT-NBT) system with high degree of texturing along the [001]c (c-cubic) crystallographic orientation. We demonstrate giant field induced strain (~0.48%) with an ultra-low hysteresis along with enhanced piezoelectric response (d?? ~ 190pC/N) and high temperature stability (~160C). Transmission electron microscopy (TEM) and piezoresponse force microscopy (PFM) results demonstrate smaller size highly ordered domain structure in grain-oriented specimen relative to the conventional polycrystalline ceramics. The grain oriented specimens exhibited a high degree of non-180 domain switching, in comparison to the randomly axed ones. These results indicate the effective solution to the lead-free piezoelectric materials.

  3. Level: National Data and Regional Totals; Row: NAICS Codes, Value of Shipments and Employment Sizes;

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

    0 Capability to Switch Coal to Alternative Energy Sources, 2006; Level: National Data and Regional Totals; Row: NAICS Codes, Value of Shipments and Employment Sizes; Column: Energy Sources; Unit: Thousand Short Tons. NAICS Total Not Electricity Natural Distillate Residual Code(a) Subsector and Industry Consumed(c) Switchable Switchable Receipts(d) Gas Fuel Oil Fuel Oil LPG Other(e) Total United States 311 Food 6,603 1,013 5,373 27 981 303 93 271 86 3112 Grain and Oilseed Milling 5,099 658 4,323

  4. Level: National and Regional Data; Row: NAICS Codes, Value of Shipments and Employment Sizes;

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

    6 Capability to Switch Electricity to Alternative Energy Sources, 2010; Level: National and Regional Data; Row: NAICS Codes, Value of Shipments and Employment Sizes; Column: Energy Sources; Unit: Million Kilowatthours. Coal Coke NAICS Total Not Natural Distillate Residual and Code(a) Selected Subsectors and Industry Receipts(c) Switchable Switchable Gas Fuel Oil Fuel Oil Coal LPG Breeze Other(d) Total United States 311 Food 75,673 2,403 70,987 666 1,658 Q 406 Q Q 141 3112 Grain and Oilseed

  5. High-flux plasma exposure of ultra-fine grain tungsten

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

    Kolasinski, R. D.; Buchenauer, D. A.; Doerner, R. P.; Fang, Z. Z.; Ren, C.; Oya, Y.; Michibayashi, K.; Friddle, R. W.; Mills, B. E.

    2016-05-12

    Here we examine the response of an ultra-fine grained (UFG) tungsten material to high-flux deuterium plasma exposure. UFG tungsten has received considerable interest as a possible plasma-facing material in magnetic confinement fusion devices, in large part because of its improved resistance to neutron damage. However, optimization of the material in this manner may lead to trade-offs in other properties. Moreover, we address two aspects of the problem in this work: (a) how high-flux plasmas modify the structure of the exposed surface, and (b) how hydrogen isotopes become trapped within the material. The specific UFG tungsten considered here contains 100 nm-widthmore » Ti dispersoids (1 wt%) that limit the growth of the W grains to a median size of 960 nm. Metal impurities (Fe, Cr) as well as O were identified within the dispersoids; these species were absent from the W matrix. To simulate relevant particle bombardment conditions, we exposed specimens of the W-Ti material to low energy (100 eV), high-flux (> 1022 m-2 s-1) deuterium plasmas in the PISCES-A facility at the University of California, San Diego. To explore different temperature-dependent trapping mechanisms, we considered a range of exposure temperatures between 200 °C and 500 °C. For comparison, we also exposed reference specimens of conventional powder metallurgy warm-rolled and ITER-grade tungsten at 300 °C. Post-mortem focused ion beam profiling and atomic force microscopy of the UFG tungsten revealed no evidence of near-surface bubbles containing high pressure D2 gas, a common surface degradation mechanism associated with plasma exposure. Thermal desorption spectrometry indicated moderately higher trapping of D in the material compared with the reference specimens, though still within the spread of values for different tungsten grades found in the literature database. Finally, for the criteria considered here, these results do not indicate any significant obstacles to the potential use of UFG

  6. Three-dimensional dust-ion-acoustic rogue waves in a magnetized dusty pair-ion plasma with nonthermal nonextensive electrons and opposite polarity dust grains

    SciTech Connect (OSTI)

    Guo, Shimin Mei, Liquan

    2014-08-15

    Dust-ion-acoustic (DIA) rogue waves are investigated in a three-dimensional magnetized plasma containing nonthermal electrons featuring Tsallis distribution, both positive and negative ions, and immobile dust grains having both positive and negative charges. Via the reductive perturbation method, a (3?+?1)-dimensional nonlinear Schrdinger (NLS) equation is derived to govern the dynamics of the DIA wave packets. The modulation instability of DIA waves described by the (3?+?1)-dimensional NLS equation is investigated. By means of the similarity transformation and symbolic computation, both the first- and second-order rogue wave solutions of the (3?+?1)-dimensional NLS equation are constructed in terms of rational functions. Moreover, the dynamics properties and the effects of plasma parameters on the nonlinear structures of rogue waves are discussed in detail. The results could be useful for understanding the physical mechanism of rogue waves in laboratory experiments where pair-ion plasmas with electrons and dust grains can be found.

  7. Doubly Distributed Transactions

    Energy Science and Technology Software Center (OSTI)

    2014-08-25

    Doubly Distributed Transactions (D2T) offers a technique for managing operations from a set of parallel clients with a collection of distributed services. It detects and manages faults. Example code with a test harness is also provided

  8. Distributed Wind 2015

    Broader source: Energy.gov [DOE]

    Distributed Wind 2015 is committed to the advancement of both distributed and community wind energy. This two day event includes a Business Conference with sessions focused on advancing the...

  9. Effect of the pre-existing carbides on the grain boundary network during grain boundary engineering in a nickel based alloy

    SciTech Connect (OSTI)

    Liu, Tingguang; Xia, Shuang; Li, Hui; Zhou, Bangxin; Bai, Qin

    2014-05-01

    Grain boundary engineering was carried out on an aging-treated nickel based Alloy 690, which has precipitated carbides at grain boundaries. Electron backscatter diffraction technique was used to investigate the grain boundary networks. Results show that, compared with the solution-annealed samples, the aging-treated samples with pre-existing carbides at grain boundaries need longer duration or higher temperature during annealing after low-strain tensile deformation for forming high proportion of low-? coincidence site lattice grain boundaries (more than 75%). The reason is that the primary recrystallization is inhibited or retarded owing to that the pre-existing carbides are barriers to grain boundaries migration. - Highlights: Study of GBE as function of pre-existing GB carbides, tensile strain and annealing Recrystallization of GBE is inhibited or retarded by the pre-existing carbides. Retained carbides after annealing show the original GB positions. More than 80% of special GBs were formed after the modification of GBE processing. Multiple twinning during recrystallization is the key process of GBE.

  10. Hazards of explosives dusts: Particle size effects

    SciTech Connect (OSTI)

    Cashdollar, K L; Hertzberg, M; Green, G M

    1992-02-01

    At the request of the Department of Energy, the Bureau of Mines has investigated the hazards of military explosives dispersed as dust clouds in a 20-L test chamber. In this report, the effect of particle size for HMX, HNS, RDX, TATB, and TNT explosives dusts is studied in detail. The explosibility data for these dusts are also compared to those for pure fuel dusts. The data show that all of the sizes of the explosives dusts that were studied were capable of sustaining explosions as dust clouds dispersed in air. The finest sizes (<10 [mu]m) of explosives dusts were less reactive than the intermediate sizes (20 to 60 [mu]m); this is opposite to the particle size effect observed previously for the pure fuel dusts. At the largest sizes studied, the explosives dusts become somewhat less reactive as dispersed dust clouds. The six sizes of the HMX dust were also studied as dust clouds dispersed in nitrogen.

  11. Characterization of etch pits found on a large-grain bulk niobium superconducting radio-frequency resonant cavity

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

    Zhao, Xin; Ciovati, G.; Bieler, T. R.

    2010-12-15

    The performance of superconducting radio-frequency (SRF) resonant cavities made of bulk niobium is limited by nonlinear localized effects. Surface analysis of regions of higher power dissipation is thus of intense interest. Such areas (referred to as “hotspots”) were identified in a large-grain single-cell cavity that had been buffered-chemical polished and dissected for examination by high resolution electron microscopy, electron backscattered diffraction microscopy (EBSD), and optical microscopy. Pits with clearly discernible crystal facets were observed in both “hotspot” and “coldspot” specimens. The pits were found in-grain, at bicrystal boundaries, and on tricrystal junctions. They are interpreted as etch pits induced bymore » crystal defects (e.g. dislocations). All coldspots examined had a qualitatively lower density of etch pits or relatively smooth tricrystal boundary junctions. EBSD mapping revealed the crystal orientation surrounding the pits. Locations with high pit density are correlated with higher mean values of the local average misorientation angle distributions, indicating a higher geometrically necessary dislocation content. In addition, a survey of the samples by energy dispersive x-ray analysis did not show any significant contamination of the samples’ surface. In conclusion, the local magnetic field enhancement produced by the sharp-edge features observed on the samples is not sufficient to explain the observed degradation of the cavity quality factor, which starts at peak surface magnetic field as low as 20 mT.« less

  12. The performance of a solar-regenerated open-cycle desiccant bed grain cooling system

    SciTech Connect (OSTI)

    Ismail, M.Z.; Angus, D.E. ); Thorpe, G.R. )

    1991-01-01

    The cooling of stored food grains suppresses the growth of populations of insect pests, inhibits spoilage by fungi and helps to preserve grain quality. In temperate and subtropical climates, grains may be effectively cooled by ventilating them with ambient air. In tropical climates, the enthalpy of the air must be reduced before it can be used for cooling grain. One method of achieving this is to isothermally reduce the humidity of the air. This paper describes experiments carried out on a simple-to-build solar-regenerated open-cycle grain cooling system. The device consists of a 5.85 m{sup 2} collector coupled with two beds of silica gel. Results from a series of experiments suggest that the device may be used to cool up to 200 tons of grain. The electrical power consumption of the device is of the order of 0.3 watt per ton of grain cooled, and the total electrical energy consumption is of the order of 0.7 kWh per ton of grain stored for a six-month period. The effectiveness of the device is a function of air flow rate and the enthalpy of ambient air, and results presented in this paper suggest that the solar cooling device is particularly effective in tropical climates.

  13. Method for producing ultrafine-grained materials using repetitive corrugation and straightening

    DOE Patents [OSTI]

    Zhu, Yuntian T.; Lowe, Terry C.; Jiang, Honggang; Huang, Jianyu

    2001-01-01

    A method of refining the grain structure and improving the hardness and strength properties of a metal or metal alloy workpiece is disclosed. The workpiece is subjected to forces that corrugate and then straighten the workpiece. These steps are repeated until an ultrafine-grained product having improved hardness and strength is produced.

  14. FRIB cryogenic distribution system

    SciTech Connect (OSTI)

    Ganni, Venkatarao; Dixon, Kelly D.; Laverdure, Nathaniel A.; Knudsen, Peter N.; Arenius, Dana M.; Barrios, Matthew N.; Jones, S.; Johnson, M.; Casagrande, Fabio

    2014-01-01

    The Michigan State University Facility for Rare Isotope Beams (MSU-FRIB) helium distribution system has been revised to include bayonet/warm valve type disconnects between each cryomodule and the transfer line distribution system, similar to the Thomas Jefferson National Accelerator Facility (JLab) and the Spallation Neutron Source (SNS) cryogenic distribution systems. The heat loads at various temperature levels and some of the features in the design of the distribution system are outlined. The present status, the plans for fabrication, and the procurement approach for the helium distribution system are also included.

  15. Effect of Dust Grains on Solitary Kinetic Alfven Wave

    SciTech Connect (OSTI)

    Li Yangfang; Wu, D. J.; Morfill, G. E.

    2008-09-07

    Solitary kinetic Alfven wave has been studied in dusty plasmas. The effect of the dust charge-to-mass ratio is considered. We derive the Sagdeev potential for the soliton solutions based on the hydrodynamic equations. A singularity in the Sagdeev potential is found and this singularity results in a bell-shaped soliton. The soliton solutions comprise two branches. One branch is sub-Alfvenic and the soliton velocities are much smaller than the Alfven speed. The other branch is super-Alfvenic and the soliton velocities are very close to or greater than the Alfven speed. Both compressive and rarefactive solitons can exist in each branch. For the sub-Alfvenic branch, the rarefactive soliton is a bell shape curve which is much narrower than the compressive one. In the super-Alfvenic branch, however, the compressive soliton is bell-shaped and the rarefactive one is broadened. We also found that the super-Alfvenic solitons can develop to other structures. When the charge-to-mass ratio of the dust grains is sufficiently high, the width of the rarefactive soliton will increase extremely and an electron density depletion will be observed. When the velocity is much higher than the Alfven speed, the bell-shaped soliton will transit to a cusped structure.

  16. The Effect of Eectronic Energy Loss on Irradiation-Induced Grain Growth in Nanocrystalline Oxides

    SciTech Connect (OSTI)

    Zhang, Yanwen; Aidhy, Dilpuneet S.; Varga, Tamas; Moll, Sandra; Edmondson, P. D.; Namavar, Fereydoon; Jin, Ke; Ostrouchov, Christopher N.; Weber, William J.

    2014-01-01

    Grain growth of nanocrystalline materials is generally thermally activated, but can also be driven by irradiation at much lower temperature. In nanocrystalline ceria and zirconia, contributions from both displacement damage and ionization to the grain growth are identified. Our atomistic simulations have revealed fast grain boundary (GB) movements due to the high density of disorder near GBs. Our experimental results have shown that irradiation-induced grain growth is a function of total energy deposited, where the excitation of target electrons and displacement of lattice atoms both contribute to the overall disorder and both play important roles in grain growth. The coupling of energy deposition to the electronic and lattice structures should both be taken into consideration when engineering nanostructural materials.

  17. Grain boundary plane orientation fundamental zones and structure-property relationships

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

    Homer, Eric R.; Patala, Srikanth; Priedeman, Jonathan L.

    2015-10-26

    Grain boundary plane orientation is a profoundly important determinant of character in polycrystalline materials that is not well understood. This work demonstrates how boundary plane orientation fundamental zones, which capture the natural crystallographic symmetries of a grain boundary, can be used to establish structure-property relationships. Using the fundamental zone representation, trends in computed energy, excess volume at the grain boundary, and temperature-dependent mobility naturally emerge and show a strong dependence on the boundary plane orientation. Analysis of common misorientation axes even suggests broader trends of grain boundary energy as a function of misorientation angle and plane orientation. Due to themore » strong structure-property relationships that naturally emerge from this work, boundary plane fundamental zones are expected to simplify analysis of both computational and experimental data. This standardized representation has the potential to significantly accelerate research in the topologically complex and vast five-dimensional phase space of grain boundaries.« less

  18. Grain boundary plane orientation fundamental zones and structure-property relationships

    SciTech Connect (OSTI)

    Homer, Eric R.; Patala, Srikanth; Priedeman, Jonathan L.

    2015-10-26

    Grain boundary plane orientation is a profoundly important determinant of character in polycrystalline materials that is not well understood. This work demonstrates how boundary plane orientation fundamental zones, which capture the natural crystallographic symmetries of a grain boundary, can be used to establish structure-property relationships. Using the fundamental zone representation, trends in computed energy, excess volume at the grain boundary, and temperature-dependent mobility naturally emerge and show a strong dependence on the boundary plane orientation. Analysis of common misorientation axes even suggests broader trends of grain boundary energy as a function of misorientation angle and plane orientation. Due to the strong structure-property relationships that naturally emerge from this work, boundary plane fundamental zones are expected to simplify analysis of both computational and experimental data. This standardized representation has the potential to significantly accelerate research in the topologically complex and vast five-dimensional phase space of grain boundaries.

  19. Cooperative chemical rebonding in the segregation of impurities in silicon grain boundaries

    SciTech Connect (OSTI)

    Maiti, A.; Chisholm, M.F.; Pennycook, S.J.; Pantelides, S.T.

    1996-12-01

    With ab initio calculations the authors show that the experimentally observed large segregation energies of As at Si grain boundaries can be explained by the formation of isolated dimers or ordered chains of dimers of threefold-coordinated As along the cores of grain boundary dislocations. They also find the intriguing possibility that As segregation may drive structural transformation of certain grain boundaries. Recently, they have obtained the first atomic-resolution STEM images of As in a Si grain boundary, consistent with the formation of As dimers. Segregation energy of As dimers was found to be significantly higher in isolated dislocation cores, where larger site-variation in strain than in grain boundaries lead to further lowering of the electronic levels of As deep into the bandgap.

  20. Goddard rattler-jamming mechanism for quantifying pressure dependence of elastic moduli of grain packs

    SciTech Connect (OSTI)

    Pride, Steven R.; Berryman, James G.

    2009-01-05

    An analysis is presented to show how it is possible for unconsolidated granular packings to obey overall non-Hertzian pressure dependence due to the imperfect and random spatial arrangements of the grains in these packs. With imperfect arrangement, some gaps that remain between grains can be closed by strains applied to the grain packing. As these gaps are closed, former rattler grains become jammed and new stress-bearing contacts are created that increase the elastic stiffness of the packing. By allowing for such a mechanism, detailed analytical expressions are obtained for increases in bulk modulus of a random packing of grains with increasing stress and strain. Only isotropic stress and strain are considered in this analysis. The model is shown to give a favorable fit to laboratory data on variations in bulk modulus due to variations in applied pressure for bead packs.

  1. Scaling Semantic Graph Databases in Size and Performance

    SciTech Connect (OSTI)

    Morari, Alessandro; Castellana, Vito G.; Villa, Oreste; Tumeo, Antonino; Weaver, Jesse R.; Haglin, David J.; Choudhury, Sutanay; Feo, John T.

    2014-08-06

    In this paper we present SGEM, a full software system for accelerating large-scale semantic graph databases on commodity clusters. Unlike current approaches, SGEM addresses semantic graph databases by only employing graph methods at all the levels of the stack. On one hand, this allows exploiting the space efficiency of graph data structures and the inherent parallelism of graph algorithms. These features adapt well to the increasing system memory and core counts of modern commodity clusters. On the other hand, however, these systems are optimized for regular computation and batched data transfers, while graph methods usually are irregular and generate fine-grained data accesses with poor spatial and temporal locality. Our framework comprises a SPARQL to data parallel C compiler, a library of parallel graph methods and a custom, multithreaded runtime system. We introduce our stack, motivate its advantages with respect to other solutions and show how we solved the challenges posed by irregular behaviors. We present the result of our software stack on the Berlin SPARQL benchmarks with datasets up to 10 billion triples (a triple corresponds to a graph edge), demonstrating scaling in dataset size and in performance as more nodes are added to the cluster.

  2. DNA fragment sizing and sorting by laser-induced fluorescence

    DOE Patents [OSTI]

    Hammond, Mark L.; Jett, James H.; Keller, Richard A.; Marrone, Babetta L.; Martin, John C.

    1996-01-01

    A method is provided for sizing DNA fragments using high speed detection systems, such as flow cytometry to determine unique characteristics of DNA pieces from a sample. In one characterization the DNA piece is fragmented at preselected sites to produce a plurality of DNA fragments. The DNA piece or the resulting DNA fragments are treated with a dye effective to stain stoichiometrically the DNA piece or the DNA fragments. The fluorescence from the dye in the stained fragments is then examined to generate an output functionally related to the number of nucleotides in each one of the DNA fragments. In one embodiment, the intensity of the fluorescence emissions from each fragment is linearly related to the fragment length. The distribution of DNA fragment sizes forms a characterization of the DNA piece for use in forensic and research applications.

  3. Fuel cells in distributed generation

    SciTech Connect (OSTI)

    O'Sullivan, J.B.

    1999-07-01

    In the past the vertically integrated electric utility industry has not utilized Distributed Generation (DG) because it was viewed as competition to central station power production. Gas utilities have been heavily and aggressively involved in the promotion of gas fired DG because for them it is additional load that may also balance the winter load. With deregulation and restructuring of the electricity industry DG is now viewed in a different light. For those utilities that have sold their generation assets DG can be a new retail service to provide to their customers. For those who are still vertically integrated, DG can be an asset management tool at the distribution level. DG can be utilized to defer capital investments involving line and substation upgrades. Coupled to this new interest in DG technologies and their performance characteristics are the associated interests in implementation issues. These range from the codes and standards requirements and hardware for interfacing to the grid as well as C{sup 3}-I (command, control, communication--intelligence) issues. The latter involves dispatching on-grid or customer sited resources, monitoring their performance and tracking the economic transactions. Another important aspect is the impact of DG resources (size, number and location) on service area dynamic behavior (power quality, reliability, stability, etc.). EPRI has ongoing programs addressing all these aspects of DG and the distribution grid. Since fuel cells can be viewed as electrochemical engines, and as with thermomechanical engines, there doesn't have to be a best fuel cell. Each engine can serve many markets and some will be better suited than others in a specific market segment (e.g. spark ignition in cars and turbines in planes). This paper will address the status of developing fuel cell technologies and their application to various market areas within the context of Distributed Generation.

  4. Distributed generation systems model

    SciTech Connect (OSTI)

    Barklund, C.R.

    1994-12-31

    A slide presentation is given on a distributed generation systems model developed at the Idaho National Engineering Laboratory, and its application to a situation within the Idaho Power Company`s service territory. The objectives of the work were to develop a screening model for distributed generation alternatives, to develop a better understanding of distributed generation as a utility resource, and to further INEL`s understanding of utility concerns in implementing technological change.

  5. Linking atomistic and mesoscale simulations of nanocrystalline materials : quantitative validation for the case of grain growth.

    SciTech Connect (OSTI)

    Moldovan, D.; Wolf, D.; Phillpot, S. R.; Materials Science Division; Louisiana State Univ.

    2003-11-01

    Using grain growth in nanocrystalline palladium as a simple case study, we demonstrate how a novel mesoscale approach for simulating microstructural evolution in polycrystalline materials can be validated directly against atomic-level simulations of the same system. We first describe molecular dynamics simulations of grain growth in a columnar model microstructure. The atomic-level insights into the grain-growth mechanism gained from these simulations, particularly in the role of grain rotations, are captured theoretically for incorporation into the mesoscale approach, in which the objects evolving in space and time are the grain boundaries and grain junctions rather than the atoms. With all the input parameters to the mesoscale being physically well defined and obtained directly from the atomic-level simulations, the mesoscale simulations are fully prescribed. We find that the morphology of the mesoscale system evolves in an almost identical manner with that of the molecular dynamics simulation, demonstrating that the length- and time-scale linking has been performed correctly. When applied to systems containing large numbers of grains, the now validated mesoscale simulation approach allows the growth topology and long-time growth kinetics to be determined. As an outlook, we describe how the effects of applied stress can be incorporated.

  6. In situ synchrotron study of electromigration induced grain rotations in Sn solder joints

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

    Shen, Hao; Zhu, Wenxin; Li, Yao; Tamura, Nobumichi; Chen, Kai

    2016-04-18

    In this paper we report an in situ study of the early stage of microstructure evolution induced by electromigration in a Pb-free β-Sn based solder joint by synchrotron polychromatic X-ray microdiffraction. With this technique, crystal orientation evolution is monitored at intragranular levels with high spatial and angular resolution. During the entire experiment, no crystal growth is detected, and rigid grain rotation is observed only in the two grains within the current crowding region, where high density and divergence of electric current occur. Theoretical calculation indicates that the trend of electrical resistance drop still holds under the present conditions in themore » grain with high electrical resistivity, while the other grain with low resistivity reorients to align its a-axis more parallel with the ones of its neighboring grains. A detailed study of dislocation densities and subgrain boundaries suggests that grain rotation in β-Sn, unlike grain rotation in high melting temperature metals which undergo displacive deformation, is accomplished via diffusional process mainly, due to the high homologous temperature.« less

  7. Coal Distribution Database, 2006

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

    TF RailroadVesselShip Fuel It is also noted that Destination State code of "X Export" indicates movements to foreign destinations. 1 68 Domestic Coal Distribution...

  8. Distribution of Correspondence

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1996-08-30

    Defines correct procedures for distribution of correspondence to the Naval Reactors laboratories. Does not cancel another directive. Expired 8-30-97.

  9. Ductless Hydronic Distribution Systems

    Broader source: Energy.gov [DOE]

    This presentation is from a Building America webinar conducted on November 8, 2011, by the Alliance for Residential Building Innovation (ARBI) about ductless hydronic distribution systems.

  10. Cooling water distribution system

    DOE Patents [OSTI]

    Orr, Richard

    1994-01-01

    A passive containment cooling system for a nuclear reactor containment vessel. Disclosed is a cooling water distribution system for introducing cooling water by gravity uniformly over the outer surface of a steel containment vessel using an interconnected series of radial guide elements, a plurality of circumferential collector elements and collector boxes to collect and feed the cooling water into distribution channels extending along the curved surface of the steel containment vessel. The cooling water is uniformly distributed over the curved surface by a plurality of weirs in the distribution channels.

  11. Annual Coal Distribution Tables

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

    Domestic Distribution of U.S. Coal by Destination State, Consumer, Destination and Method of Transportation, 2001 (Thousand Short Tons) DESTINATION: Alabama State of Origin by...

  12. Coal Distribution Database, 2006

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

    Report - Annual provides detailed information on domestic coal distribution by origin state, destination state, consumer category, and method of transportation. Also provided is...

  13. PV distribution system

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

    distribution system - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us ... Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & ...

  14. Distribution Grid Integration

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

    Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & ... of the distributed, or local, power generation into the electric power system. ...

  15. Method for synthesizing fine-grained phosphor powders of the type (RE.sub.1- Ln.sub.x)(P.sub.1-y V.sub.y)O.sub.4

    DOE Patents [OSTI]

    Phillips, Mark L. F.

    1998-01-01

    A method for generating well-crystallized photo- and cathodoluminescent oxide phosphor powders. The method of this invention uses hydrothermal synthesis and annealing to produce nearly monosized (RE.sub.1-x Ln.sub.x)(P.sub.1-y V.sub.y)O.sub.4 (Ln.dbd.Ce.fwdarw.Lu) phosphor grains with crystallite sizes from 0.04 to 5 .mu.m. Such phosphors find application in cathode-ray tube, flat-panel, and projection displays.

  16. Grain Handling and Transportation Policy in Canada: Implications for the United States

    SciTech Connect (OSTI)

    Nolan, James; Peterson, Steven K

    2015-01-01

    The grain handling and transportation system in Canada (GHTS) is currently going through a major transition, both with respect to handling and transportation. Historically, the system has pitted farmers against the railways with respect to securing individual fair shares of grain revenues. But with the removal of the single desk marketing and logistics function of the Canadian Wheat Board (CWB) in late 2012, a very interesting and potentially game-changing outcome is emerging with respect to the new functionality of the grain companies in the Canadian system. While historical awareness of rail s natural monopoly position in the grain handling system has kept that sector regulated (in several ways) for close to a century, we are now starting to see the effects of a less than competitive Canadian grain handling sector on revenue sharing, along with renewed movement in the industry with respect to buyouts and potential mergers. This overview will highlight some of the changes now occurring and how they are potentially going to interact or evolve as the system moves forward. For example, the on-going regulatory instrument used to regulate grain transportation rates in Canada (called the maximum revenue entitlement (MRE) or revenue cap) is under current debate because of the introduction a few months ago of a modification to an old regulatory instrument known as extended (or reciprocal) interswitching. As opposed to the revenue cap which is a direct intervention on monopoly behavior, extended interswitching is designed to encourage the major Canadian grain carriers to compete with one another and potentially seek out new traffic (Nolan and Skotheim, 2008). But the most intriguing aspect of extended interswitching is how it might allow a major rail carrier from the U.S. to solicit grain traffic in some areas of the Canadian grain transportation system.

  17. Grain Handling and Transportation Policy in Canada: Implications for the United States

    SciTech Connect (OSTI)

    Nolan, James; Peterson, Steven K

    2015-08-01

    The grain handling and transportation system in Canada (GHTS) is currently going through a major transition, both with respect to handling and transportation. Historically, the system has pitted farmers against the railways with respect to securing individual fair shares of grain revenues. But with the removal of the single desk marketing and logistics function of the Canadian Wheat Board (CWB) in late 2012, a very interesting and potentially game-changing outcome is emerging with respect to the new functionality of the grain companies in the Canadian system. While historical awareness of rail s natural monopoly position in the grain handling system has kept that sector regulated (in several ways) for close to a century, we are now starting to see the effects of a less than competitive Canadian grain handling sector on revenue sharing, along with renewed movement in the industry with respect to buyouts and potential mergers. This overview will highlight some of the changes now occurring and how they are potentially going to interact or evolve as the system moves forward. For example, the on-going regulatory instrument used to regulate grain transportation rates in Canada (called the maximum revenue entitlement (MRE) or revenue cap) is under current debate because of the introduction a few months ago of a modification to an old regulatory instrument known as extended (or reciprocal) interswitching. As opposed to the revenue cap which is a direct intervention on monopoly behavior, extended interswitching is designed to encourage the major Canadian grain carriers to compete with one another and potentially seek out new traffic (Nolan and Skotheim, 2008). But the most intriguing aspect of extended interswitching is how it might allow a major rail carrier from the U.S. to solicit grain traffic in some areas of the Canadian grain transportation system.

  18. Grain Handling and Transportation Policy in Canada: Implications for the United States

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

    Nolan, James; Peterson, Steven K

    2015-08-01

    The grain handling and transportation system in Canada (GHTS) is currently going through a major transition, both with respect to handling and transportation. Historically, the system has pitted farmers against the railways with respect to securing individual fair shares of grain revenues. But with the removal of the single desk marketing and logistics function of the Canadian Wheat Board (CWB) in late 2012, a very interesting and potentially game-changing outcome is emerging with respect to the new functionality of the grain companies in the Canadian system. While historical awareness of rail s natural monopoly position in the grain handling systemmore » has kept that sector regulated (in several ways) for close to a century, we are now starting to see the effects of a less than competitive Canadian grain handling sector on revenue sharing, along with renewed movement in the industry with respect to buyouts and potential mergers. This overview will highlight some of the changes now occurring and how they are potentially going to interact or evolve as the system moves forward. For example, the on-going regulatory instrument used to regulate grain transportation rates in Canada (called the maximum revenue entitlement (MRE) or revenue cap) is under current debate because of the introduction a few months ago of a modification to an old regulatory instrument known as extended (or reciprocal) interswitching. As opposed to the revenue cap which is a direct intervention on monopoly behavior, extended interswitching is designed to encourage the major Canadian grain carriers to compete with one another and potentially seek out new traffic (Nolan and Skotheim, 2008). But the most intriguing aspect of extended interswitching is how it might allow a major rail carrier from the U.S. to solicit grain traffic in some areas of the Canadian grain transportation system.« less

  19. Dust acoustic shock waves in two temperatures charged dusty grains

    SciTech Connect (OSTI)

    El-Shewy, E. K.; Abdelwahed, H. G.; Elmessary, M. A.

    2011-11-15

    The reductive perturbation method has been used to derive the Korteweg-de Vries-Burger equation and modified Korteweg-de Vries-Burger for dust acoustic shock waves in a homogeneous unmagnetized plasma having electrons, singly charged ions, hot and cold dust species with Boltzmann distributions for electrons and ions in the presence of the cold (hot) dust viscosity coefficients. The behavior of the shock waves in the dusty plasma has been investigated.

  20. High-energy X-ray focusing and applications to pair distribution function investigation of Pt and Au nanoparticles at high pressures

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

    Hong, Xinguo; Ehm, Lars; Zhong, Zhong; Ghose, Sanjit; Duffy, Thomas S.; Weidner, Donald J.

    2016-02-23

    We report development of micro-focusing optics for high-energy x-rays by combining a sagittally bent Laue crystal monchromator with Kirkpatrick-Baez (K–B) X-ray focusing mirrors. The optical system is able to provide a clean, high-flux X-ray beam suitable for pair distribution function (PDF) measurements at high pressure using a diamond anvil cell (DAC). A focused beam of moderate size (10–15 μm) has been achieved at energies of 66 and 81keV. PDF data for nanocrystalline platinum (n-Pt) were collected at 12.5 GPa with a single 5 s X-ray exposure, showing that the in-situ compression, decompression, and relaxation behavior of samples in the DACmore » can be investigated with this technique. PDFs of n-Pt and nano Au (n-Au) under quasi-hydrostatic loading to as high as 71GPa indicate the existence of substantial reduction of grain or domain size for Pt and Au nanoparticles at pressures below 10 GPa. In conclusion, the coupling of sagittally bent Laue crystals with K–B mirrors provides a useful means to focus high-energy synchrotron X-rays from a bending magnet or wiggler source.« less

  1. Melting process of nanometer-sized in particles embedded in an Al matrix synthesized by ball milling

    SciTech Connect (OSTI)

    Sheng, H.W.; Xu, J.; Yu, L.G.; Sun, X.K.; Hu, Z.Q.; Lu, K.

    1996-11-01

    Dispersions of nanometer-sized In particles embedded in an Al matrix (10 wt.{percent} In) have been synthesized by ball milling of a mixture of Al and In powders. The as-milled product was characterized by using x-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive x-ray spectrometer (EDX), transmission electron microscopy (TEM), and high resolution transmission electron microscopy (HREM), respectively. It was found that In and Al are pure components immiscible with each other, with nanometer-sized In particles dispersively embedded in the Al matrix. The melting behavior of In particles was investigated by means of differential scanning calorimeter (DSC). The calorimetric measurements indicate that both the melting point and the melting enthalpy of the In nanoparticles decrease with increasing milling time, or refinement of the In particles. Compared to its bulk melting temperature, a melting point depression of 13.4 K was observed when the mean grain size of In is 15 nm, and the melting point depression of In nanoparticles is proportional to the reciprocal of the mean grain size. The melting enthalpy depression was interpreted according to the two-state concept for the nanoparticles. Melting of the interface was deduced to be an exothermal process due to its large excess energy/volume. {copyright} {ital 1996 Materials Research Society.}

  2. Process for preparing fine grain titanium carbide powder

    DOE Patents [OSTI]

    Janney, M.A.

    1985-03-12

    A method for preparing finely divided titanium carbide powder in which an organotitanate is reacted with a carbon precursor polymer to provide an admixture of the titanium and the polymer at a molecular level due to a crosslinking reaction between the organotitanate and the polymer. The resulting gel is dried, pyrolyzed to drive off volatile components and provide carbon. The resulting solids are then heated at an elevated temperature to convert the titanium and carbon to high-purity titanium carbide powder in a submicron size range.

  3. Process for preparing fine grain titanium carbide powder

    DOE Patents [OSTI]

    Janey, Mark A.

    1986-01-01

    A method for preparing finely divided titanium carbide powder in which an organotitanate is reacted with a carbon precursor polymer to provide an admixture of the titanium and the polymer at a molecular-level due to a crosslinking reaction between the organotitanate and the polymer. The resulting gel is dried, pyrolyzed to drive off volatile components and provide carbon. The resulting solids are then heated at an elevated temperature to convert the titanium and carbon to high-purity titanium carbide powder in a submicron size range.

  4. Assessing the Importance of Using Biomodal Size Distribution for Ice Cloud Optical Property Parameterizations

    SciTech Connect (OSTI)

    Stackhouse, P. W.

    2006-03-31

    This report represents the final report for DE-AI02-0 IER63074. This work represented some follow-on work to that completed under DE-AI02-0 1 ER62669. The research reported here is undertaken in collaboration with Dr. David Mitchell of the Desert Research Institute in Reno, Nevada. The progress given here represents my contribution to his approach by providing radiative transfer expertise and calculations.

  5. Optimal site selection and sizing of distributed utility-scale wind power plants

    SciTech Connect (OSTI)

    Milligan, M.R.; Artig, R.

    1998-04-01

    As electric market product unbundling occurs, sellers in the wholesale market for electricity will find it to their advantage to be able to specify the quantity of electricity available and the time of availability. Since wind power plants are driven by the stochastic nature of the wind itself, this can present difficulties. To the extent that an accurate wind forecast is available, contract deviations, and therefore penalties, can be significantly reduced. Even though one might have the ability to accurately forecast the availability of wind power, it might not be available during enough of the peak period to provide sufficient value. However, if the wind power plant is developed over geographically disperse locations, the timing and availability of wind power from these multiple sources could provide a better match with the utility`s peak load than a single site. There are several wind plants in various stages of planning or development in the US. Although some of these are small-scale demonstration projects, significant wind capacity has been developed in Minnesota, with additional developments planned in Wyoming and Iowa. As these and other projects are planned and developed, there is a need to perform analysis of the value of geographically diverse sites on the efficiency of the overall wind plant. In this paper, the authors use hourly wind-speed data from six geographically diverse sites to provide some insight into the potential benefits of disperse wind plant development. They provide hourly wind power from each of these sites to an electric reliability simulation model. This model uses generating plant characteristics of the generators within the state of Minnesota to calculate various reliability indices. Since they lack data on wholesale power transactions, they do not include them in the analysis, and they reduce the hourly load data accordingly. The authors present and compare results of their methods and suggest some areas of future research.

  6. Smart distribution systems

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

    Jiang, Yazhou; Liu, Chen -Ching; Xu, Yin

    2016-04-19

    The increasing importance of system reliability and resilience is changing the way distribution systems are planned and operated. To achieve a distribution system self-healing against power outages, emerging technologies and devices, such as remote-controlled switches (RCSs) and smart meters, are being deployed. The higher level of automation is transforming traditional distribution systems into the smart distribution systems (SDSs) of the future. The availability of data and remote control capability in SDSs provides distribution operators with an opportunity to optimize system operation and control. In this paper, the development of SDSs and resulting benefits of enhanced system capabilities are discussed. Amore » comprehensive survey is conducted on the state-of-the-art applications of RCSs and smart meters in SDSs. Specifically, a new method, called Temporal Causal Diagram (TCD), is used to incorporate outage notifications from smart meters for enhanced outage management. To fully utilize the fast operation of RCSs, the spanning tree search algorithm is used to develop service restoration strategies. Optimal placement of RCSs and the resulting enhancement of system reliability are discussed. Distribution system resilience with respect to extreme events is presented. Furthermore, test cases are used to demonstrate the benefit of SDSs. Active management of distributed generators (DGs) is introduced. Future research in a smart distribution environment is proposed.« less

  7. Particle impactor assembly for size selective high volume air sampler

    DOE Patents [OSTI]

    Langer, Gerhard

    1988-08-16

    Air containing entrained particulate matter is directed through a plurality of parallel, narrow, vertically oriented impactor slots of an inlet element toward an adjacently located, relatively large, dust impaction surface preferably covered with an adhesive material. The air flow turns over the impaction surface, leaving behind the relatively larger particles according to the human thoracic separation system and passes through two elongate exhaust apertures defining the outer bounds of the impaction collection surface to pass through divergent passages which slow down and distribute the air flow, with entrained smaller particles, over a fine filter element that separates the fine particles from the air. The elongate exhaust apertures defining the impaction collection surface are spaced apart by a distance greater than the lengths of elongate impactor slots in the inlet element and are oriented to be normal thereto. By appropriate selection of dimensions and the number of impactor slots air flow through the inlet element is provided a nonuniform velocity distribution with the lower velocities being obtained near the center of the impactor slots, in order to separate out particles larger than a certain predetermined size on the impaction collection surface. The impaction collection surface, even in a moderately sized apparatus, is thus relatively large and permits the prolonged sampling of air for periods extending to four weeks.

  8. Characterization of Large Grain Nb Ingot Microstructure Using EBSP Mapping and Laue Camera Methods

    SciTech Connect (OSTI)

    Kang Di; Baars, Derek C.; Bieler, Thomas R.; Compton, Chris C.

    2011-03-31

    Large grain/single crystal Nb is currently being examined for fabricating superconducting radiofrequency (SRF) cavities as an alternative to using rolled sheet. Three ingot slices from different suppliers have been characterized and are compared. It is desirable to know the grain orientations of an ingot slice before fabrication. Characterization of an ingot slice has been done using electron backscattered pattern (EBSP) orientation imaging microscopy (OIM), which requires cutting out pieces from the slice, a destructive technique. Use of a Laue camera allows nondestructive characterization of grain orientations. The OIM method was used to examine ingot slices from CBMM and Ningxia, while the Laue method was used to examine a Heraeus ingot slice. The three ingot slices are compared in terms of their crystal orientations and grain boundary misorientations, indicating no obvious commonalities. The Laue method has practical advantages over OIM for evaluating ingot slices during the manufacturing process.

  9. A little drop will do it: Tiny grains of lithium can dramatically...

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

    A little drop will do it: Tiny grains of lithium can dramatically improve the performance ... Right: Cross-section of plasma in which lithium has turned the emitted light green. ...

  10. A little drop will do it: Tiny grains of lithium can dramatically...

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

    A little drop will do it: Tiny grains of lithium can dramatically improve the performance ... Right, Cross-section of plasma in which lithium has turned the emitted light green. ...

  11. Nondestructive method and apparatus for imaging grains in curved surfaces of polycrystalline articles

    DOE Patents [OSTI]

    Carpenter, Donald A.

    1995-01-01

    A nondestructive method, and associated apparatus, are provided for determining the grain flow of the grains in a convex curved, textured polycrystalline surface. The convex, curved surface of a polycrystalline article is aligned in a horizontal x-ray diffractometer and a monochromatic, converging x-ray beam is directed onto the curved surface of the polycrystalline article so that the converging x-ray beam is diffracted by crystallographic planes of the grains in the polycrystalline article. The diffracted x-ray beam is caused to pass through a set of horizontal, parallel slits to limit the height of the beam and thereafter. The linear intensity of the diffracted x-ray is measured, using a linear position sensitive proportional counter, as a function of position in a direction orthogonal to the counter so as to generate two dimensional data. An image of the grains in the curved surface of the polycrystalline article is provided based on the two-dimensional data.

  12. Deformation mechanisms, defects, heat treatment, and thermal conductivity in large grain niobium

    SciTech Connect (OSTI)

    Bieler, Thomas R. Kang, Di Baars, Derek C.; Chandrasekaran, Saravan; Mapar, Aboozar Wright, Neil T.; Ciovati, Gianluigi Myneni, Ganapati Rao; Pourboghrat, Farhang; Murphy, James E.; Compton, Chris C.

    2015-12-04

    The physical and mechanical metallurgy underlying fabrication of large grain cavities for superconducting radio frequency accelerators is summarized, based on research of 1) grain orientations in ingots, 2) a metallurgical assessment of processing a large grain single cell cavity and a tube, 3) assessment of slip behavior of single crystal tensile samples extracted from a high purity ingot slice before and after annealing at 800 °C / 2 h, 4) development of crystal plasticity models based upon the single crystal experiments, and 5) assessment of how thermal conductivity is affected by strain, heat treatment, and exposure to hydrogen. Because of the large grains, the plastic anisotropy of deformation is exaggerated, and heterogeneous strains and localized defects are present to a much greater degree than expected in polycrystalline material, making it highly desirable to computationally anticipate potential forming problems before manufacturing cavities.

  13. Distribution Workshop | Department of Energy

    Office of Environmental Management (EM)

    Variable distributed generation Dispatchable distributed generation Electric vehicle charging and electrolyzers Energy storage Building and industrial loads and demand response ...

  14. Determination of surface recombination velocity at a grain boundary using electron-beam-induced current

    SciTech Connect (OSTI)

    Burk, D.E.; Kanner, S.; Muyshondt, J.E.; Shaulis, D.S.; Russell, P.E.

    1983-01-01

    In order to determine the surface recombination velocity at a grain boundary surface, computer-aided calculations of the theoretical electron-beam-induced-current response to a point source excitation are fitted to data taken as a function of distance from the grain boundary. It is demonstrated that the data is in good agreement with this theoretical response for distances greater than two maximum penetration depths of the incident electron beam.

  15. Ultra-Fine Grain Foils and Sheets by Large-Strain Extrusion Machining |

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

    Department of Energy Fine Grain Foils and Sheets by Large-Strain Extrusion Machining Ultra-Fine Grain Foils and Sheets by Large-Strain Extrusion Machining 2011 DOE Hydrogen and Fuel Cells Program, and Vehicle Technologies Program Annual Merit Review and Peer Evaluation lm034_rohatgi_2011_o.pdf (1.05 MB) More Documents & Publications Vehicle Technologies Office: 2010 Lightweight Materials R&D Annual Progress Report Nanostructured Materials by Machining 2011 Annual Progress Report for

  16. Distributed generation: Early markets for emerging technologies

    SciTech Connect (OSTI)

    Lenssen, N.; Cler, G.

    1999-11-01

    How will developers of emerging distributed generation technologies successfully commercialize their products. This paper presents one approach for these developers, borrowing from the experience of other developers of innovative technologies and services. E Source`s analysis suggests, however, that there is already more of a market for distributed generation than is generally recognized. US and Canadian firms already buy about 3,400 megawatts of small generators each year, mostly for backup power but some as the primary power source for selected loads and facilities. This demand is expected to double in 10 years. The global market for small generators is already more than 10 times this size, at some 40,000 megawatts per year, and it is expected to continue growing rapidly, especially in developing nations. Just how the emerging distributed generation technologies, such as microturbines, fuel cells, and Stirling engines compete-or surpass-the conventional technologies will have a huge impact on their eventual commercial success.

  17. Assessment of Available Particle Size Data to Support an Analysis of the Waste Feed Delivery System Transfer System

    SciTech Connect (OSTI)

    JEWETT, J.R.

    2000-08-10

    Available data pertaining to size distribution of the particulates in Hanford underground tank waste have been reviewed. Although considerable differences exist between measurement methods, it may be stated with 95% confidence that the median particle size does not exceed 275 {micro}m in at least 95% of the ten tanks selected as sources of HLW feed for Phase 1 vitrification in the RPP. This particle size is recommended as a design basis for the WFD transfer system.

  18. Morphological changes in ultrafast laser ablation plumes with varying spot size

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

    Harilal, S. S.; Diwakar, P. K.; Polek, M. P.; Phillips, M. C.

    2015-06-04

    We investigated the role of spot size on plume morphology during ultrafast laser ablation of metal targets. Our results show that the spatial features of fs LA plumes are strongly dependent on the focal spot size. Two-dimensional self-emission images showed that the shape of the ultrafast laser ablation plumes changes from spherical to cylindrical with an increasing spot size from 100 to 600 ?m. The changes in plume morphology and internal structures are related to ion emission dynamics from the plasma, where broader angular ion distribution and faster ions are noticed for the smallest spot size used. The present resultsmoreclearly show that the morphological changes in the plume with spot size are independent of laser pulse width.less

  19. Direct Experimental Evaluation of the Grain Boundaries Gas Content in PWR fuels: New Insight and Perspective of the ADAGIO Technique

    SciTech Connect (OSTI)

    Pontillon, Y.; Noirot, J.; Caillot, L.

    2007-07-01

    Over the last decades, many analytical experiments (in-pile and out-of-pile) have underlined the active role of the inter-granular gases on the global fuel transient behavior under accidental conditions such as RIA and/or LOCA. In parallel, the improvement of fission gas release modeling in nuclear fuel performance codes needs direct experimental determination/validation regarding the local gas distribution inside the fuel sample. In this context, an experimental program, called 'ADAGIO' (French acronym for Discriminating Analysis of Accumulation of Inter-granular and Occluded Gas), has been initiated through a joint action of CEA, EDF and AREVA NP in order to develop a new device/technique for quantitative and direct measurement of local fission gas distribution within an irradiated fuel pellet. ADAGIO technique is based on the fact that fission gas inventory (intra and inter-granular parts) can be distinguished by controlled fuel oxidation, since grain boundaries oxidize faster than the bulk. The purpose of the current paper is to present both the methodology and the associated results of the ADAGIO program performed at CEA. It has been divided into two main parts: (i) feasibility (UO{sub 2} and MOX fuels), (ii) application on high burn up UO{sub 2} fuel. (authors)

  20. Domestic and Foreign Distribution

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

    of U.S. Coal by State of Origin, 2008 Final May 2010 Domestic and Foreign Distribution of U.S. Coal by State of Origin, 2008 (Thousand Short Tons) State Region Domestic Foreign...

  1. Distributed Energy Resource Program

    Broader source: Energy.gov [DOE]

    Note: A series of orders issued on July 15, 2015 in  Docket 2015-53-E, Docket 2015-54-E, and Docket 2015-55-E approved the incentive programs for South Carolina's Distributed Energy Resource...

  2. Coal Distribution Database, 2008

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

    4Q 2009 April 2010 Quarterly Coal Distribution Table Format and Data Sources 4Q 2009 In keeping with EIA's efforts to increase the timeliness of its reports, this Quarterly Coal...

  3. Coal Distribution Database, 2008

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

    3Q 2009 February 2010 Quarterly Coal Distribution Table Format and Data Sources 3Q 2009 In keeping with EIA's efforts to increase the timeliness of its reports, this Quarterly Coal...

  4. Distributed Wind Energy Workshop

    Broader source: Energy.gov [DOE]

    Join instructor Brent Summerville for a fun and interactive workshop at Appalachian State University's Small Wind Research and Demonstration Site. Learn about a variety of distributed wind energy...

  5. Sizing of DNA fragments by flow cytometry

    SciTech Connect (OSTI)

    Johnson, M.E.; Goodwin, P.M.; Ambrose, W.P.; Martin, J.C.; Marrone, B.L.; Jett, J.H.; Keller, R.A.

    1993-02-01

    Individual, stained DNA fragments were sized using a modified flow cytometer with high sensitivity fluorescence detection. The fluorescent intercalating dye ethidium homodimer was used to stain stoichiometrically lambda phage DNA and a Kpn I digest of lambda DNA. Stained, individual fragments of DNA were passed through a low average power, focused, mode-locked laser beam, and the fluorescence from each fragment was collected and quantified. Time-gated detection was used to discriminate against Raman scattering from the water solvent. The fluorescence burst from each fragment was related directly to its length, thus providing a means to size small quantities of kilobase lengths of DNA quickly. Improvements of several orders of magnitude in analysis time and sample size over current gel electrophoresis techniques were realized. Fragments of 17.1,29.9, and 48.5 thousand base pairs were well resolved, and were sized in 164 seconds. Less than one pg of DNA was required for analysis. We have demonstrated sizing of individual, stained DNA fragments with resolution approaching that of gel electrophoresis for moderately large fragments, but with significant reductions in the analysis time and the amount of sample required. Furthermore, system response is linear with DNA fragment length, in contrast to the logarithmic response in gel electrophoresis. There exists the potential to perform this sizing using relatively simple instrumentation, i.e. a continuous wave laser of low power and current mode detection.

  6. Sizing of DNA fragments by flow cytometry

    SciTech Connect (OSTI)

    Johnson, M.E.; Goodwin, P.M.; Ambrose, W.P.; Martin, J.C.; Marrone, B.L.; Jett, J.H.; Keller, R.A.

    1993-01-01

    Individual, stained DNA fragments were sized using a modified flow cytometer with high sensitivity fluorescence detection. The fluorescent intercalating dye ethidium homodimer was used to stain stoichiometrically lambda phage DNA and a Kpn I digest of lambda DNA. Stained, individual fragments of DNA were passed through a low average power, focused, mode-locked laser beam, and the fluorescence from each fragment was collected and quantified. Time-gated detection was used to discriminate against Raman scattering from the water solvent. The fluorescence burst from each fragment was related directly to its length, thus providing a means to size small quantities of kilobase lengths of DNA quickly. Improvements of several orders of magnitude in analysis time and sample size over current gel electrophoresis techniques were realized. Fragments of 17.1,29.9, and 48.5 thousand base pairs were well resolved, and were sized in 164 seconds. Less than one pg of DNA was required for analysis. We have demonstrated sizing of individual, stained DNA fragments with resolution approaching that of gel electrophoresis for moderately large fragments, but with significant reductions in the analysis time and the amount of sample required. Furthermore, system response is linear with DNA fragment length, in contrast to the logarithmic response in gel electrophoresis. There exists the potential to perform this sizing using relatively simple instrumentation, i.e. a continuous wave laser of low power and current mode detection.

  7. Glass bead size and morphology characteristics in support of Crystal Mist field experiments

    SciTech Connect (OSTI)

    Einfeld, W.

    1995-03-01

    One of the tasks of the Lethality Group within US Army Space and Strategic Defense Command (USASSDC) is the development of a capability to simulate various missile intercept scenarios using computer codes. Currently under development within USASSDC and its various contractor organizations is a group of codes collected under a master code called PEGEM for Post Event Ground Effects Model. Among the various components of the code are modules which are used to predict atmospheric dispersion and transport of particles or droplets following release at the altitude specified in the missile intercept scenario. The atmospheric transport code takes into account various source term data from the intercept such as: initial cloud size; droplet or particle size distribution; and, total mass of agent released. An ongoing USASSDC experimental program termed Crystal Mist involved release of precision glass beads under various altitude and meteorological conditions to assist in validation and refinement of various codes that are components of PEGEM used to predict particle atmospheric transport and diffusion following a missile intercept. Here, soda-lime glass beads used in the Crystal Mist series of atmospheric transport and diffusion tests were characterized by scanning electron microscopy and automated image processing routines in order to fully define their size distributions and morphology. Four bead size classifications ranging from a median count diameter of 45 to 200 micrometers were found to be approximately spherical and to fall within the supplier`s sizing specifications. Log-normal functions fit to the measured size distributions resulted in geometric standard deviations ranging from 1.08 to 1.12, thereby fulfilling the field trial requirements for a relatively narrow bead size distribution.

  8. Quantum dense key distribution

    SciTech Connect (OSTI)

    Degiovanni, I.P.; Ruo Berchera, I.; Castelletto, S.; Rastello, M.L.; Bovino, F.A.; Colla, A.M.; Castagnoli, G.

    2004-03-01

    This paper proposes a protocol for quantum dense key distribution. This protocol embeds the benefits of a quantum dense coding and a quantum key distribution and is able to generate shared secret keys four times more efficiently than the Bennet-Brassard 1984 protocol. We hereinafter prove the security of this scheme against individual eavesdropping attacks, and we present preliminary experimental results, showing its feasibility.

  9. Hydrogen Pathway Cost Distributions

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

    Pathway Cost Distributions Jim Uihlein Fuel Pathways Integration Tech Team January 25, 2006 2 Outline * Pathway-Independent Cost Goal * Cost Distribution Objective * Overview * H2A Influence * Approach * Implementation * Results * Discussion Process * Summary 3 Hydrogen R&D Cost Goal * Goal is pathway independent * Developed through a well defined, transparent process * Consumer fueling costs are equivalent or less on a cents per mile basis * Evolved gasoline ICE and gasoline-electric

  10. Distributed generation hits market

    SciTech Connect (OSTI)

    1997-10-01

    The pace at which vendors are developing and marketing gas turbines and reciprocating engines for small-scale applications may signal the widespread growth of distributed generation. Loosely defined to refer to applications in which power generation equipment is located close to end users who have near-term power capacity needs, distributed generation encompasses a broad range of technologies and load requirements. Disagreement is inevitable, but many industry observers associate distributed generation with applications anywhere from 25 kW to 25 MW. Ten years ago, distributed generation users only represented about 2% of the world market. Today, that figure has increased to about 4 or 5%, and probably could settle in the 20% range within a 3-to-5-year period, according to Michael Jones, San Diego, Calif.-based Solar Turbines Inc. power generation marketing manager. The US Energy Information Administration predicts about 175 GW of generation capacity will be added domestically by 2010. If 20% comes from smaller plants, distributed generation could account for about 35 GW. Even with more competition, it`s highly unlikely distributed generation will totally replace current market structures and central stations. Distributed generation may be best suited for making market inroads when and where central systems need upgrading, and should prove its worth when the system can`t handle peak demands. Typical applications include small reciprocating engine generators at remote customer sites or larger gas turbines to boost the grid. Additional market opportunities include standby capacity, peak shaving, power quality, cogeneration and capacity rental for immediate demand requirements. Integration of distributed generation systems--using gas-fueled engines, gas-fired combustion engines and fuel cells--can upgrade power quality for customers and reduce operating costs for electric utilities.

  11. Investigations of initiation spot size effects

    SciTech Connect (OSTI)

    Clarke, Steven A; Akinci, Adrian A; Leichty, Gary; Schaffer, Timothy; Murphy, Michael J; Munger, Alan; Thomas, Keith A

    2010-01-01

    As explosive components become smaller, a greater understanding of the effect of initiation spot size on detonation becomes increasingly critical. A series of tests of the effect of initiation spot size will be described. A series of DOI (direct optical initiation) detonators with initiation spots sizes from {approx}50 um to 1000um have been tested to determine laser parameters for threshold firing of low density PETN pressings. Results will be compared with theoretical predictions. Outputs of the initiation source (DOI ablation) have been characterized by a suite of diagnostics including PDV and schlieren imaging. Outputs of complete detonators have been characterized using PDV, streak, and/or schlieren imaging. At present, we have not found the expected change in the threshold energy to spot size relationship for DOI type detonators found in similar earlier for projectiles, slappers and EBWs. New detonators designs (Type C) are currently being tested that will allow the determination of the threshold for spot sizes from 250 um to 105um, where we hope to see change in the threshold vs. spot size relationship. Also, one test of an extremely small diameter spot size (50um) has resulted in preliminary NoGo only results even at energy densities as much as 8 times the energy density of the threshold results presented here. This gives preliminary evidence that 50um spot may be beyond the critical initiation diameter. The constant threshold energy to spot size relationship in the data to date does however still give some insight into the initiation mechanism of DOI detonators. If the DOI initiation mechanism were a 1D mechanism similar to a slapper or a flyer impact, the expected inflection point in the graph would have been between 300um and 500um diameter spot size, within the range of the data presented here. The lack of that inflection point indicates that the DOI initiation mechanism is more likely a 2D mechanism similar to a sphere or rod projectile. We expect to

  12. Artificial neural network modeling of the spontaneous combustion occurring in the industrial-scale coal stockpiles with 10-18 mm coal grain sizes

    SciTech Connect (OSTI)

    Ozdeniz, A.H.; Yilmaz, N.

    2009-07-01

    Companies consuming large amounts of coal should work with coal stocks in order to not face problems due to production delays. The industrial-scale stockpiles formed for the aforementioned reasons cause environmental problems and economic losses for the companies. This study was performed in a coal stock area of a large company in Konya, which uses large amounts of coal in its manufacturing units. The coal stockpile with 5 m width, 10 m length, 3 m height, and having 120 tons of weight was formed in the coal stock area of the company. The inner temperature data of the stockpile was recorded by 17 temperature sensors placed inside the stockpile at certain points. In order to achieve this goal, the electrical signal conversion of temperatures sensed by 17 temperature sensors placed in certain points inside the coal stockpile, the transfer of these electrical signals into computer media by using analog-digital conversion unit after applying necessary filtration and upgrading processes, and the record of these information into a database in particular time intervals are provided. Additionally, the data relating to the air temperature, air humidity, atmospheric pressure, wind velocity, and wind direction that are the parameters affecting the coal stockpile were also recorded. Afterwards, these measurement values were used for training and testing of an artificial neural network model. Comparison of the experimental and artificial neural network results, accuracy rates of training and testing were found to be 99.5% and 99.17%, respectively. It is shown that possible coal stockpile behavior with this artificial neural network model is powerfully estimated.

  13. Top 10 Things You Didn't Know About Distributed Wind Power | Department

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

    of Energy Distributed Wind Power Top 10 Things You Didn't Know About Distributed Wind Power August 10, 2015 - 8:20am Addthis Small-Scale Distributed Wind: Northern Power Systems 100 kW turbine at the top of Burke Mountain in East Burke, Vermont. | Photo courtesy of Northern Power Systems. Small-Scale Distributed Wind: Northern Power Systems 100 kW turbine at the top of Burke Mountain in East Burke, Vermont. | Photo courtesy of Northern Power Systems. Mid-Sized Distributed Wind: Two mid-sized

  14. Drying grain using crop residence as a fuel source. Final technical report

    SciTech Connect (OSTI)

    Hammond, C.

    1982-08-01

    An indirectly-fired biomass fueled furnace was evaluated to determine the feasibility of drying grain using crop residues as a fuel source. The furnace efficiency and total heat delivery were determined. Funds for this project were provided by the Department of Energy through an appropriate technology grant. Stalks and residue were harvested in large round bales using conventional hay-handling equipment available on most farms. Calorimeter tests were made to determine the heat content available in various residues prior to combustion in the Stormor Bio Mass Heat System. This allowed total efficiency measurements by comparing total heat available and total heat delivered to the grain dryer. For example, a bale of cotton stalks returned over 60 percent of the useable heat for an efficiency of 63.7 percent. Other residues such as corn stalks gave slightly lower efficiency but clearly showed that adequate heat could be obtained to dry grain using heated air and no petroleum fuels. The air from the furnace went through an air-to-air heat exchanger to prevent contamination of the grain from smoke and combustion by-products. Although reducing efficiency somewhat, the heat exchanger allows grain or other materials such as peanuts to be dried for human consumption. Some evidence of overheating of the firebox doors was observed which led to some warping of the doors. This warping subsequently made temperature control more difficult, since the air supply and burn rate are directly related. Air temperatures of up to 160/sup 0/F were measured. The results show that biomass combustion as a fuel source to dry grain is possible with fuel savings of about ten cents per bushel at current fuel prices. Thus, the cost of the biomass burner could be recovered in drying some 70,000 bushels of grain. 5 figures, 5 tables.

  15. Distributed Wind Market Applications

    SciTech Connect (OSTI)

    Forsyth, T.; Baring-Gould, I.

    2007-11-01

    Distributed wind energy systems provide clean, renewable power for on-site use and help relieve pressure on the power grid while providing jobs and contributing to energy security for homes, farms, schools, factories, private and public facilities, distribution utilities, and remote locations. America pioneered small wind technology in the 1920s, and it is the only renewable energy industry segment that the United States still dominates in technology, manufacturing, and world market share. The series of analyses covered by this report were conducted to assess some of the most likely ways that advanced wind turbines could be utilized apart from large, central station power systems. Each chapter represents a final report on specific market segments written by leading experts in this field. As such, this document does not speak with one voice but rather a compendium of different perspectives, which are documented from a variety of people in the U.S. distributed wind field.

  16. Distributed data transmitter

    DOE Patents [OSTI]

    Brown, Kenneth Dewayne; Dunson, David

    2008-06-03

    A distributed data transmitter (DTXR) which is an adaptive data communication microwave transmitter having a distributable architecture of modular components, and which incorporates both digital and microwave technology to provide substantial improvements in physical and operational flexibility. The DTXR has application in, for example, remote data acquisition involving the transmission of telemetry data across a wireless link, wherein the DTXR is integrated into and utilizes available space within a system (e.g., a flight vehicle). In a preferred embodiment, the DTXR broadly comprises a plurality of input interfaces; a data modulator; a power amplifier; and a power converter, all of which are modularly separate and distinct so as to be substantially independently physically distributable and positionable throughout the system wherever sufficient space is available.

  17. Distributed data transmitter

    DOE Patents [OSTI]

    Brown, Kenneth Dewayne; Dunson, David

    2006-08-08

    A distributed data transmitter (DTXR) which is an adaptive data communication microwave transmitter having a distributable architecture of modular components, and which incorporates both digital and microwave technology to provide substantial improvements in physical and operational flexibility. The DTXR has application in, for example, remote data acquisition involving the transmission of telemetry data across a wireless link, wherein the DTXR is integrated into and utilizes available space within a system (e.g., a flight vehicle). In a preferred embodiment, the DTXR broadly comprises a plurality of input interfaces; a data modulator; a power amplifier; and a power converter, all of which are modularly separate and distinct so as to be substantially independently physically distributable and positionable throughout the system wherever sufficient space is available.

  18. VAR Support from Distributed Wind Energy Resources: Preprint

    SciTech Connect (OSTI)

    Romanowitz, H.; Muljadi, E.; Butterfield, C. P.; Yinger, R.

    2004-07-01

    As the size and quantity of wind farms and other distributed generation facilities increase, especially in relation to local grids, the importance of a reactive power compensator or VAR support from these facilities becomes more significant. Poorly done, it can result in cycling or inadequate VAR support, and the local grid could experience excessive voltage regulation and, ultimately, instability. Improved wind turbine and distributed generation power control technologies are creating VAR support capabilities that can be used to enhance the voltage regulation and stability of local grids. Locating VAR support near the point of consumption, reducing step size, and making the control active all improve the performance of the grid. This paper presents and discusses alternatives for improving the integration of VAR support from distributed generation facilities such as wind farms. We also examine the relative effectiveness of distributed VAR support on the local grid and how it can b e integrated with the VAR support of the grid operator.

  19. Facies distributions within contrasting structural components of a rift lake: Lake Tanganyika, Africa

    SciTech Connect (OSTI)

    Soreghan, M.J.; Cohen, A.S. )

    1991-03-01

    Lake Tanganyika is the most widely cited modern analog for interpreting ancient rift lakes; thus, understanding controls on its facies distribution is critical for refining stratigraphic models for rifts. Four recurrent margin types occur along the alternating half-graben structure of the lake: rift axes, platforms, escarpments, and accommodation zones. Data from study sites in the northern part of the lake suggest that predictable facies differences exist between these structural margin types. The rift axis site comprises a low-gradient, clastic (wave/current)-dominated deltaic system, with strong facies asymmetry and minor carbonate accumulations on raised benches. The platform margin site comprises a series of structurally controlled benches over which long, continuous facies tracts occur. Carbonate sands, muds, and shell gravel dominate; clastics are limited to moderate-sized silty deltas and long, narrow shoreface sands. The escarpment margin site is a steep-gradient system along which small ({lt}1 km{sup 2}) fan deltas alternate with cemented talus. The accommodation zone margin sites are also dominated by rugged structural relief, generally small fan deltas, and semicontinuous shoreface sand belts ({gt}5 km) onshore and poorly sorted silts offshore. TOC from fine-grained samples reflects the contrast in margin types. TOC values for the platform and rift axis range from 0.4 - 2.1 wt. % (avg. 1.3%), whereas accommodation zone and escarpment margin values range from 0.5-5.5% (avg. 3.0%). Acid insoluble sulfur shows a similar trend. Although all data are significantly correlated with depth, the relative area of the lake margin above and below the oxicline is directly controlled by the structural style of the lake margin.

  20. Size separation of analytes using monomeric surfactants

    DOE Patents [OSTI]

    Yeung, Edward S.; Wei, Wei

    2005-04-12

    A sieving medium for use in the separation of analytes in a sample containing at least one such analyte comprises a monomeric non-ionic surfactant of the of the general formula, B-A, wherein A is a hydrophilic moiety and B is a hydrophobic moiety, present in a solvent at a concentration forming a self-assembled micelle configuration under selected conditions and having an aggregation number providing an equivalent weight capable of effecting the size separation of the sample solution so as to resolve a target analyte(s) in a solution containing the same, the size separation taking place in a chromatography or electrophoresis separation system.

  1. Neutron and weak-charge distributions of the 48Ca nucleus

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

    Hagen, Gaute; Forssen, Christian; Nazarewicz, Witold; Papenbrock, Thomas F.; Bacca, S.; Barnea, Nir; Carlsson, Boris; Drischler, Christian; Hebeler, Kai; Hjorth-Jensen, M.; et al

    2015-11-02

    What is the size of the atomic nucleus? This deceivably simple question is difficult to answer. Although the electric charge distributions in atomic nuclei were measured accurately already half a century ago, our knowledge of the distribution of neutrons is still deficient. In addition to constraining the size of atomic nuclei, the neutron distribution also impacts the number of nuclei that can exist and the size of neutron stars. We present an ab initio calculation of the neutron distribution of the neutron-rich nucleus 48Ca. We show that the neutron skin (difference between the radii of the neutron and proton distributions)more » is significantly smaller than previously thought. We also make predictions for the electric dipole polarizability and the weak form factor; both quantities that are at present targeted by precision measurements. Here, based on ab initio results for 48Ca, we provide a constraint on the size of a neutron star.« less

  2. Power-law and exponential rank distributions: A panoramic Gibbsian perspective

    SciTech Connect (OSTI)

    Eliazar, Iddo

    2015-04-15

    Rank distributions are collections of positive sizes ordered either increasingly or decreasingly. Many decreasing rank distributions, formed by the collective collaboration of human actions, follow an inverse power-law relation between ranks and sizes. This remarkable empirical fact is termed Zipf’s law, and one of its quintessential manifestations is the demography of human settlements — which exhibits a harmonic relation between ranks and sizes. In this paper we present a comprehensive statistical-physics analysis of rank distributions, establish that power-law and exponential rank distributions stand out as optimal in various entropy-based senses, and unveil the special role of the harmonic relation between ranks and sizes. Our results extend the contemporary entropy-maximization view of Zipf’s law to a broader, panoramic, Gibbsian perspective of increasing and decreasing power-law and exponential rank distributions — of which Zipf’s law is one out of four pillars.

  3. Distributed Sensors Simulator

    Energy Science and Technology Software Center (OSTI)

    2003-08-30

    The Distributed Sensors Simulator (DSS) is an infrastructure that allows the user to debug and test software for distributed sensor networks without the commitment inherent in using hardware. The flexibility of DSS allows developers and researchers to investigate topological, phenomenological, networking, robustness, and scaling issues; explore arbitrary algorithms for DSNs; and is particularly useful as a proof-of-concept tool. The user provides data on node location and specifications, defines event phenomena, and plugs in the application(s)more » to run. DSS in turn provides the virtual environmental embedding — but exposed to the user like no true embedding could ever be.« less

  4. Multiscale simulation of xenon diffusion and grain boundary segregation in UO₂

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

    Andersson, David A.; Tonks, Michael R.; Casillas, Luis; Vyas, Shyam; Nerikar, Pankaj; Uberuaga, Blas P.; Stanek, Christopher R.

    2015-07-01

    In light water reactor fuel, gaseous fission products segregate to grain boundaries, resulting in the nucleation and growth of large intergranular fission gas bubbles. The segregation rate is controlled by diffusion of fission gas atoms through the grains and interaction with the boundaries. Based on the mechanisms established from earlier density functional theory (DFT) and empirical potential calculations, diffusion models for xenon (Xe), uranium (U) vacancies and U interstitials in UO₂ have been derived for both intrinsic (no irradiation) and irradiation conditions. Segregation of Xe to grain boundaries is described by combining the bulk diffusion model with a model formore » the interaction between Xe atoms and three different grain boundaries in UO₂ (Σ5 tilt, Σ5 twist and a high angle random boundary), as derived from atomistic calculations. The present model does not attempt to capture nucleation or growth of fission gas bubbles at the grain boundaries. The point defect and Xe diffusion and segregation models are implemented in the MARMOT phase field code, which is used to calculate effective Xe and U diffusivities as well as to simulate Xe redistribution for a few simple microstructures.« less

  5. Testing thermal gradient driving force for grain boundary migration using molecular dynamics simulations

    SciTech Connect (OSTI)

    Bai, Xian-Ming; Zhang, Yongfeng; Tonks, Michael R.

    2015-02-01

    Strong thermal gradients in low-thermal-conductivity ceramics may drive extended defects, such as grain boundaries and voids, to migrate in preferential directions. In this work, molecular dynamics simulations are conducted to study thermal gradient driven grain boundary migration and to verify a previously proposed thermal gradient driving force equation, using uranium dioxide as a model system. It is found that a thermal gradient drives grain boundaries to migrate up the gradient and the migration velocity increases under a constant gradient owing to the increase in mobility with temperature. Different grain boundaries migrate at very different rates due to their different intrinsic mobilities. The extracted mobilities from the thermal gradient driven simulations are compared with those calculated from two other well-established methods and good agreement between the three different methods is found, demonstrating that the theoretical equation of the thermal gradient driving force is valid, although a correction of one input parameter should be made. The discrepancy in the grain boundary mobilities between modeling and experiments is also discussed.

  6. Spatially Resolved Mapping of Electrical Conductivity around Individual Domain (Grain) Boundaries in Graphene

    SciTech Connect (OSTI)

    Li, An-Ping [ORNL; Clark, Kendal W [ORNL; Zhang, Xiaoguang [ORNL; Vlassiouk, Ivan V [ORNL; He, Guowei [Carnegie Mellon University (CMU); Feenstra, Randall [Carnegie Mellon University (CMU)

    2013-01-01

    Graphene films can now be produced on the scale of up to meters. However, all large-scale graphene films contain topological defects that can significantly affect the characteristic transport behaviors of graphene. Here, we spatially map the structures and electronic transport near specific domain and grain boundaries in graphene, and evaluate effects of different types of defect on the electronic conductivity in epitaxial graphene grown on SiC and CVD graphene on Cu subsequently transferred to a SiO2 substrate. We use a combined approach with a multi-probe scanning tunneling potentiometry to investigate both structures and transport at individual grain boundaries and domain boundaries that are defined by coalesced grains, surface steps, and changes in layer thickness. It is found that the substrate step on SiC presents a significant potential barrier for electron transport of epitaxial graphene due to the reduced charge transport from the substrate at the step edges, monolayer-bilayer boundaries exhibit a high resistivity that can change depending on directions of the current across the boundary, and the resistivity of grain boundaries changes with the transition width of the disordered region between two adjacent grains in graphene. The detailed understanding of graphene defects will provide the feedback for controlled engineering of defects in large-scale graphene films.

  7. Multiscale simulation of xenon diffusion and grain boundary segregation in UO₂

    SciTech Connect (OSTI)

    Andersson, David A.; Tonks, Michael R.; Casillas, Luis; Vyas, Shyam; Nerikar, Pankaj; Uberuaga, Blas P.; Stanek, Christopher R.

    2015-07-01

    In light water reactor fuel, gaseous fission products segregate to grain boundaries, resulting in the nucleation and growth of large intergranular fission gas bubbles. The segregation rate is controlled by diffusion of fission gas atoms through the grains and interaction with the boundaries. Based on the mechanisms established from earlier density functional theory (DFT) and empirical potential calculations, diffusion models for xenon (Xe), uranium (U) vacancies and U interstitials in UO₂ have been derived for both intrinsic (no irradiation) and irradiation conditions. Segregation of Xe to grain boundaries is described by combining the bulk diffusion model with a model for the interaction between Xe atoms and three different grain boundaries in UO₂ (Σ5 tilt, Σ5 twist and a high angle random boundary), as derived from atomistic calculations. The present model does not attempt to capture nucleation or growth of fission gas bubbles at the grain boundaries. The point defect and Xe diffusion and segregation models are implemented in the MARMOT phase field code, which is used to calculate effective Xe and U diffusivities as well as to simulate Xe redistribution for a few simple microstructures.

  8. Final report : phase I investigation at the former CCC/USDA grain storage facility in Savannah, Missouri.

    SciTech Connect (OSTI)

    LaFreniere, L. M.; Environmental Science Division

    2010-08-05

    From approximately 1949 until 1970, the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) operated a grain storage facility on federally owned property approximately 0.25 mi northwest of Savannah, Missouri (Figure 1.1). During this time, commercial grain fumigants containing carbon tetrachloride were commonly used by the CCC/USDA and the private grain storage industry to preserve grain in their facilities. In November 1998, carbon tetrachloride was detected in a private well (Morgan) roughly 50 ft south of the former CCC/USDA facility, as a result of state-wide screening of private wells near former CCC/USDA facilities, conducted in Missouri by the U.S. Environmental Protection Agency (EPA 1999). The 1998 and subsequent investigations by the EPA and the Missouri Department of Natural Resources (MoDNR) confirmed the presence of carbon tetrachloride in the Morgan well, as well as in a second well (on property currently owned and occupied by the Missouri Department of Transportation [MoDOT]), described as being approximately 400 ft east of the former CCC/USDA facility. The identified concentrations in these two wells were above the EPA maximum contaminant level (MCL) and the default target level (DTL) values of 5.0 {micro}g/L for carbon tetrachloride in water used for domestic purposes (EPA 1999; MoDNR 2000a,b, 2006). (The DTL is defined in Section 4.) Because the observed contamination in the Morgan and MoDOT wells might be linked to the past use of carbon tetrachloride-based fumigants at its former grain storage facility, the CCC/USDA is conducting an investigation to (1) characterize the source(s), extent, and factors controlling the subsurface distribution and movement of carbon tetrachloride at Savannah and (2) evaluate the potential risks to human health, public welfare, and the environment posed by the contamination. This work is being performed in accord with the Intergovernmental Agreement established between the Farm Service

  9. Distributed Wind | Department of Energy

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

    Distributed Wind Distributed Wind The Wind Program's activities in wind technologies in distributed applications-or distributed wind-address the performance and reliability challenges associated with smaller turbines by focusing on technology development, testing, certification, and manufacturing. What is Distributed Wind? Photo of a turbine behind a school. The Wind Program defines distributed wind in terms of technology application, based on a wind plant's location relative to end-use and

  10. Exploration of the mechanisms of temperature-dependent grain boundary mobility: Search for the common origin of ultrafast grain boundary motion

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

    O’Brien, C. J.; Foiles, S. M.

    2016-04-19

    The temperature dependence of grain boundary mobility is complex, varied, and rarely fits ideal Arrhenius behavior. This work presents a series of case studies of planar grain boundaries in a model FCC system that were previously demonstrated to exhibit a variety of temperature-dependent mobility behaviors. It is demonstrated that characterization of the mobility versus temperature plots is not sufficient to predict the atomic motion mechanism of the grain boundaries. Herein, the temperature-dependent motion and atomistic motion mechanisms of planar grain boundaries are driven by a synthetic, orientation-dependent, driving force. The systems studied include CSL boundaries with Σ values of 5,more » 7, and 15, including both symmetric and asymmetric boundaries. These boundaries represent a range of temperature-dependent trends including thermally activated, antithermal, and roughening behaviors. Examining the atomic-level motion mechanisms of the thermally activated boundaries reveals that each involves a complex shuffle, and at least one atom that changes the plane it resides on. The motion mechanism of the antithermal boundary is qualitatively different and involves an in-plane coordinated shuffle that rotates atoms about a fixed atom lying on a point in the coincident site lattice. Furthermore, this provides a mechanistic reason for the observed high mobility, even at low temperatures, which is due to the low activation energy needed for such motion. However, it will be demonstrated that this mechanism is not universal, or even common, to other boundaries exhibiting non-thermally activated motion. This work concludes that no single atomic motion mechanism is sufficient to explain the existence of non-thermally activated boundary motion.« less

  11. Aerosol distribution apparatus

    DOE Patents [OSTI]

    Hanson, W.D.

    An apparatus for uniformly distributing an aerosol to a plurality of filters mounted in a plenum, wherein the aerosol and air are forced through a manifold system by means of a jet pump and released into the plenum through orifices in the manifold. The apparatus allows for the simultaneous aerosol-testing of all the filters in the plenum.

  12. Two Photon Distribution Amplitudes

    SciTech Connect (OSTI)

    El Beiyad, M.; Pire, B.; Szymanowski, L.; Wallon, S.

    2008-08-29

    The factorization of the amplitude of the process {gamma}*{gamma}{yields}{gamma}{gamma} in the low energy and high photon virtuality region is demonstrated at the Born order and in the leading logarithmic approximation. The leading order two photon (generalized) distribution amplitudes exhibit a characteristic ln Q{sup 2} behaviour and obey new inhomogeneous evolution equations.

  13. Annual Coal Distribution Tables

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

    and Foreign Distribution of U.S. Coal by State of Origin, 2001 State Region Domestic Foreign Total Alabama 14,828 4,508 19,336 Alaska 825 698 1,524 Arizona 13,143 - 13,143...

  14. Distribution Category: Water R

    Office of Scientific and Technical Information (OSTI)

    Distribution Category: Water R e a c t o r Safety- R e s e a r c h - - A n a l y s i s ... 8 10 I TOTAL VOLUMETRIC FLUX, ms Fig. 9. Fully Developed Air-Water Flow Data.30 ANL Neg. ...

  15. A method for preparation and cleaning of uniformly sized arsenopyrite particles

    SciTech Connect (OSTI)

    Parthasarathy, Hariprasad; Baltrus, John P; Dzombak, David A; Karamalidis, Athanasios K

    2014-10-11

    The oxidative dissolution of sulfide minerals, such as arsenopyrite (FeAsS), is of critical importance in many geochemical systems. A comprehensive understanding of their dissolution rates entails careful preparation of the mineral surface. Measurements of dissolution rates of arsenic from arsenopyrite are dependent on the size and degree of oxidation of its particles, among other factors. In this work, a method was developed for preparation and cleaning of arsenopyrite particles with size range of 150250 ?m. Four different cleaning methods were evaluated for effectiveness based on the removal of oxidized species of iron (Fe), arsenic (As) and sulfur (S) from the surface. The percentage oxidation of the surface was determined using X-ray photoelectron spectroscopy (XPS), and surface stoichiometry was measured using scanning electron microscopy energy dispersive X-ray spectroscopy (SEM-EDS). Results indicate that sonicating the arsenopyrite particles and then cleaning them with 12N HCl followed by 50% ethanol, and drying in nitrogen was the most effective method. This method was successful in greatly reducing the oxide species of Fe while completely removing oxides of As and S from the arsenopyrite surface. Although sonication and acid cleaning have been widely used for mineral preparation, the method described in this study can significantly reduce grain size heterogeneity as well as surface oxidation, which enables greater control in surface and dissolution experiments.

  16. A method for preparation and cleaning of uniformly sized arsenopyrite particles

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

    Parthasarathy, Hariprasad; Baltrus, John P; Dzombak, David A; Karamalidis, Athanasios K

    2014-10-11

    The oxidative dissolution of sulfide minerals, such as arsenopyrite (FeAsS), is of critical importance in many geochemical systems. A comprehensive understanding of their dissolution rates entails careful preparation of the mineral surface. Measurements of dissolution rates of arsenic from arsenopyrite are dependent on the size and degree of oxidation of its particles, among other factors. In this work, a method was developed for preparation and cleaning of arsenopyrite particles with size range of 150–250 μm. Four different cleaning methods were evaluated for effectiveness based on the removal of oxidized species of iron (Fe), arsenic (As) and sulfur (S) from themore » surface. The percentage oxidation of the surface was determined using X-ray photoelectron spectroscopy (XPS), and surface stoichiometry was measured using scanning electron microscopy – energy dispersive X-ray spectroscopy (SEM-EDS). Results indicate that sonicating the arsenopyrite particles and then cleaning them with 12N HCl followed by 50% ethanol, and drying in nitrogen was the most effective method. This method was successful in greatly reducing the oxide species of Fe while completely removing oxides of As and S from the arsenopyrite surface. Although sonication and acid cleaning have been widely used for mineral preparation, the method described in this study can significantly reduce grain size heterogeneity as well as surface oxidation, which enables greater control in surface and dissolution experiments.« less

  17. Process of Equiaxed Grains of RE-Al Alloy under Slope Vibration

    SciTech Connect (OSTI)

    Xie Shikun; Yi Rongxi; Pan Xiaoliang; Zheng Xiaoqiu; Guo Xiuyan [School of Engineering, Jinggangshan University, Ji'an, 343009 (China)

    2010-06-15

    A new technique using slope vibration casting process during heating and isothermal holding period to prepare Al-7Si-2RE alloy has been studied. The small, near-spherical and non-dendritic microstructure with the semi-solid processing requirements has been obtained. Experiments show that the cooling method, pouring process and the convection of melt caused by slope vibration had significant effects on the formation of near-spherical primary gains. The water-cooled copper mold casting with slope vibration at the temperature near liquidus can obtain Al-7Si-2RE alloy with small homogeneous equiaxed grains, the average grain diameter is 48.3 mum, and the average grain roundness is 1.92.

  18. Substitutional Boron in Nanodiamond, Bucky-Diamond, and Nanocrystalline Diamond Grain Boundaries

    SciTech Connect (OSTI)

    Barnard, Amanda S.; Sternberg, Michael G.

    2006-10-05

    Although boron has been known for many years to be a successful dopant in bulk diamond, efficient doping of nanocrystalline diamond with boron is still being developed. In general, the location, configuration, and bonding structure of boron in nanodiamond is still unknown, including the fundamental question of whether it is located within grains or grain boundaries of thin films and whether it is within the core or at the surface of nanoparticles. Presented here are density functional tight-binding simulations examining the configuration, potential energy surface, and electronic charge of substitutional boron in various types of nanocrystalline diamond. The results predict that boron is likely to be positioned at the surface of isolated particles and at the grain boundary of thin-film samples.

  19. CRADA 2009S001: Investigation of the Supercondcuting RF Properties of Large Grain Ingot Niobium

    SciTech Connect (OSTI)

    Grimm, Terry; Hollister, Jerry L.; Kolka, Ahren; Myneni, Ganapati Rao

    2012-12-18

    This CRADA intended to explore the properties of large grain ingot niobium by fabricating four single cell TESLA shaped accelerating cavities. Once the cavities were fabricated, SRF performance would be measured. Niowave received four discs of large grain ingot niobium from JLAB in February 2009. Niowave cut samples from each disc and tested the RRR. After the RRR was measured with disappointing results, the project lost interest. A no cost extension was signed in July 2009 to allow progress until June 2010, but ultimately no further work was accomplished by either party. No firm conclusions were drawn, as further investigations were not made. Large grain ingot niobium has shown real potential for high accelerating gradient superconducting cavities. However, this particular CRADA did not gather enough data to reach any conclusions in this regard.

  20. Identification of sub-grains and low angle boundaries beyond the angular resolution of EBSD maps

    SciTech Connect (OSTI)

    Germain, L.; Kratsch, D.; Salib, M.; Gey, N.

    2014-12-15

    A new method called ALGrId (Anti-Leak GRain IDentification) is proposed for the detection of sub-grains beyond the relative angular resolution of Electron Backscatter Diffraction maps. It does not use any additional information such as Kikuchi Pattern Quality map nor need data filtering. It uses a modified Dijkstra algorithm which seeks the continuous set of boundaries having the highest average disorientation angle. - Highlights: ALGrId is a new method to identify sub-grains and low angle boundaries in EBSD maps. Unlike classical methods, ALGrId works even beyond the relative angular resolution. If the orientation noise peaks at 0.7, ALGrid detects 0.4-boundaries correctly. In the same example, the classical algorithm identifies 1.1-boundaries only.

  1. A simple grand canonical approach to compute the vapor pressure of bulk and finite size systems

    SciTech Connect (OSTI)

    Factorovich, Matas H.; Scherlis, Damin A.

    2014-02-14

    In this article we introduce a simple grand canonical screening (GCS) approach to accurately compute vapor pressures from molecular dynamics or Monte Carlo simulations. This procedure entails a screening of chemical potentials using a conventional grand canonical scheme, and therefore it is straightforward to implement for any kind of interface. The scheme is validated against data obtained from Gibbs ensemble simulations for water and argon. Then, it is applied to obtain the vapor pressure of the coarse-grained mW water model, and it is shown that the computed value is in excellent accord with the one formally deduced using statistical thermodynamics arguments. Finally, this methodology is used to calculate the vapor pressure of a water nanodroplet of 94 molecules. Interestingly, the result is in perfect agreement with the one predicted by the Kelvin equation for a homogeneous droplet of that size.

  2. THREE-DIMENSIONAL LAGRANGIAN TURBULENT DIFFUSION OF DUST GRAINS IN A PROTOPLANETARY DISK: METHOD AND FIRST APPLICATIONS

    SciTech Connect (OSTI)

    Charnoz, Sebastien; Aleon, Jerome

    2011-08-10

    In order to understand how the chemical and isotopic compositions of dust grains in a gaseous turbulent protoplanetary disk are altered during their journey in the disk, it is important to determine their individual trajectories. We study here the dust-diffusive transport using Lagrangian numerical simulations using the popular 'turbulent diffusion' formalism. However, it is naturally expressed in an Eulerian form, which does not allow the trajectories of individual particles to be studied. We present a simple stochastic and physically justified procedure for modeling turbulent diffusion in a Lagrangian form that overcomes these difficulties. We show that a net diffusive flux F of the dust appears and that it is proportional to the gas density ({rho}) gradient and the dust diffusion coefficient D{sub d}: (F = D{sub d} /{rho} x grad({rho})). It induces an inward transport of dust in the disk's midplane, while favoring outward transport in the disk's upper layers. We present tests and applications comparing dust diffusion in the midplane and upper layers as well as sample trajectories of particles with different sizes. We also discuss potential applications for cosmochemistry and smoothed particle hydrodynamic codes.

  3. A multiscale variational approach to the kinetics of viscous classical liquids: The coarse-grained mean field approximation

    SciTech Connect (OSTI)

    Sereda, Yuriy V.; Ortoleva, Peter J.

    2014-04-07

    A closed kinetic equation for the single-particle density of a viscous simple liquid is derived using a variational method for the Liouville equation and a coarse-grained mean-field (CGMF) ansatz. The CGMF ansatz is based on the notion that during the characteristic time of deformation a given particle interacts with many others so that it experiences an average interaction. A trial function for the N-particle probability density is constructed using a multiscale perturbation method and the CGMF ansatz is applied to it. The multiscale perturbation scheme is based on the ratio of the average nearest-neighbor atom distance to the total size of the assembly. A constraint on the initial condition is discovered which guarantees that the kinetic equation is mass-conserving and closed in the single-particle density. The kinetic equation has much of the character of the Vlasov equation except that true viscous, and not Landau, damping is accounted for. The theory captures condensation kinetics and takes much of the character of the Gross-Pitaevskii equation in the weak-gradient short-range force limit.

  4. Influence of leaching on surface composition, microstructure, and valence band of single grain icosahedral Al-Cu-Fe quasicrystal

    SciTech Connect (OSTI)

    Lowe, M.; McGrath, R.; Sharma, H. R.; Yadav, T. P.; Fourne, V.; Ledieu, J.

    2015-03-07

    The use of quasicrystals as precursors to catalysts for the steam reforming of methanol is potentially one of the most important applications of these new materials. To develop application as a technology requires a detailed understanding of the microscopic behavior of the catalyst. Here, we report the effect of leaching treatments on the surface microstructure, chemical composition, and valence band of the icosahedral (i-) Al-Cu-Fe quasicrystal in an attempt to prepare a model catalyst. The high symmetry fivefold surface of a single grain i-Al-Cu-Fe quasicrystal was leached with NaOH solution for varying times, and the resulting surface was characterized by x-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The leaching treatments preferentially remove Al producing a capping layer consisting of Fe and Cu oxides. The subsurface layer contains elemental Fe and Cu in addition to the oxides. The quasicrystalline bulk structure beneath remains unchanged. The subsurface gradually becomes Fe{sub 3}O{sub 4} rich with increasing leaching time. The surface after leaching exhibits micron sized dodecahedral cavities due to preferential leaching along the fivefold axis. Nanoparticles of the transition metals and their oxides are precipitated on the surface after leaching. The size of the nanoparticles is estimated by high resolution transmission microscopy to be 5-20 nm, which is in agreement with the AFM results. Selected area electron diffraction (SAED) confirms the crystalline nature of the nanoparticles. SAED further reveals the formation of an interface between the high atomic density lattice planes of nanoparticles and the quasicrystal. These results provide an important insight into the preparation of model catalysts of nanoparticles for steam reforming of methanol.

  5. Irradiation-induced grain growth in nanocrystalline reduced activation ferrite/martensite steel

    SciTech Connect (OSTI)

    Liu, W. B.; Chen, L. Q. [Key Laboratory of Advanced Materials of Ministry of Education, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Zhang, C., E-mail: chizhang@tsinghua.edu.cn; Yang, Z. G. [Key Laboratory of Advanced Materials of Ministry of Education, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Ji, Y. Z. [Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Zang, H. [Department of Nuclear Science and Technology, Xi'an Jiaotong University, Xi'an 710049 (China); Shen, T. L. [Institute of Modern Physics, Chinese Academy of Science, Lanzhou 730000 (China)

    2014-09-22

    In this work, we investigate the microstructure evolution of surface-nanocrystallized reduced activation ferrite/martensite steels upon high-dose helium ion irradiation (24.3 dpa). We report a significant irradiation-induced grain growth in the irradiated buried layer at a depth of 300500?nm, rather than at the peak damage region (at a depth of ?840?nm). This phenomenon can be explained by the thermal spike model: minimization of the grain boundary (GB) curvature resulting from atomic diffusion in the cascade center near GBs.

  6. 2012 Market Report on U.S. Wind Technologies in Distributed Applications |

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

    Department of Energy An annual report on U.S. wind power in distributed applications--expanded to include small, mid-size, and utility-scale installations--including key statistics, economic data, installation, capacity, and generation statistics, and more. 2012_distributed_wind_technologies_market_report.pdf (7.63 MB) More Documents & Publications 2012 Market Report on U.S. Wind Technologies in Distributed Applications 2012 Market Report on U.S. Wind Technologies in Distributed

  7. 2012 Market Report on U.S. Wind Technologies in Distributed Applications |

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

    Department of Energy Market Report on U.S. Wind Technologies in Distributed Applications 2012 Market Report on U.S. Wind Technologies in Distributed Applications The 2012 Market Report on U.S. Wind Technologies in Distributed Applications is an annual report on U.S. wind power in distributed applications--expanded to include small, mid-size, and utility-scale installations--including key statistics, economic data, installation, capacity, and generation statistics, and more. 2012 Market

  8. Method of making quasi-grain boundary-free polycrystalline solar cell structure and solar cell structure obtained thereby

    DOE Patents [OSTI]

    Gonzalez, Franklin N.; Neugroschel, Arnost

    1984-02-14

    A new solar cell structure is provided which will increase the efficiency of polycrystalline solar cells by suppressing or completely eliminating the recombination losses due to the presence of grain boundaries. This is achieved by avoiding the formation of the p-n junction (or other types of junctions) in the grain boundaries and by eliminating the grain boundaries from the active area of the cell. This basic concept can be applied to any polycrystalline material; however, it will be most beneficial for cost-effective materials having small grains, including thin film materials.

  9. Grain refinement in heavy rare earth element-free sintered Nd–Fe–B magnets by addition of a small amount of molybdenum

    SciTech Connect (OSTI)

    Kim, Jin Woo; Lee, Won Suk; Byun, Jong Min; Kim, Young Do; Kim, Se Hoon

    2015-05-07

    We employed a modified refractory-metal-addition method to achieve higher coercivity and remanence in heavy rare earth element (HREE)-free Nd–Fe–B sintered magnets. This process involved inducing the formation of a homogeneous secondary phase at the grain boundaries during sintering, making it possible to control the intergrain diffusion by adding small amounts of Mo, a refractory metal. To control the microstructure of the secondary phase effectively, a metal organic compound of the refractory metal was coated on the surfaces of the particles of an HREE-free Nd–Fe–B powder. The average grain size after this process was 5.60 μm, which was approximately 1.8 μm smaller than that of the HREE-free sintered Nd–Fe–B magnets (7.4 μm). The coercivity of the magnets prepared through this process could be increased from 11.88 kOe to 13.91 kOe without decreasing their remanence.

  10. Multipartite secure state distribution

    SciTech Connect (OSTI)

    Duer, W.; Briegel, H.-J.; Calsamiglia, J.

    2005-04-01

    We introduce the distribution of a secret multipartite entangled state in a real-world scenario as a quantum primitive. We show that in the presence of noisy quantum channels (and noisy control operations), any state chosen from the set of two-colorable graph states (Calderbank-Shor-Steane codewords) can be created with high fidelity while it remains unknown to all parties. This is accomplished by either blind multipartite entanglement purification, which we introduce in this paper, or by multipartite entanglement purification of enlarged states, which offers advantages over an alternative scheme based on standard channel purification and teleportation. The parties are thus provided with a secret resource of their choice for distributed secure applications.

  11. Properly Understanding the Impacts of Distributed Resources on Distribution Systems

    SciTech Connect (OSTI)

    Rizy, D Tom; Li, Fangxing; Li, Huijuan; Adhikari, Sarina; Kueck, John D

    2010-01-01

    The subject paper discusses important impacts of distributed resources on distribution networks and feeders. These include capacity, line losses, voltage regulation, and central system support (such as volt/var via central generators and substation) as the number, placement and penetration levels of distributed resources are varied. Typically, the impacts of distributed resources on the distribution system are studied by using steady-state rather than dynamic analysis tools. However, the response time and transient impacts of both system equipment (such as substation/feeder capacitors) and distributed resources needs to be taken into account and only dynamic analysis will provide the full impact results. ORNL is wrapping up a study of distributed resources interconnected to a large distribution system considering the above variables. A report of the study and its results will be condensed into a paper for this panel session. The impact of distributed resources will vary as the penetration level reaches the capacity of the distribution feeder/system. The question is how high of a penetration of distributed resource can be accommodated on the distribution feeder/system without any major changes to system operation, design and protection. The impacts most surely will vary depending upon load composition, distribution and level. Also, it is expected that various placement of distributed resources will impact the distribution system differently.

  12. U.S. Distributed Wind Sector Finds Support from NREL

    SciTech Connect (OSTI)

    Sinclair, Karin

    2015-02-02

    Small and mid-sized wind turbine manufacturers in the United States have led the international distributed wind market in installed capacity for decades. Continued reductions in the cost of distributed wind systems are essential to successfully compete with currently economical photovoltaic systems. Annual capacity additions in 2013 were particularly low. In an effort to reduce the levelized cost of energy (LCOE) of distributed wind systems manufactured in the United States, the U.S. Department of Energy (DOE) has provided funding through the National Renewable Energy Laboratory (NREL) to support several projects.

  13. Symmetric generalized binomial distributions

    SciTech Connect (OSTI)

    Bergeron, H.; Curado, E. M. F.; Instituto Nacional de Cincia e Tecnologia - Sistemas Complexos, Rua Xavier Sigaud 150, 22290-180 - Rio de Janeiro, RJ ; Gazeau, J. P.; APC, UMR 7164, Univ Paris Diderot, Sorbonne Paris Cit, 75205 Paris ; Rodrigues, Ligia M. C. S. E-mail: evaldo@cbpf.br E-mail: ligia@cbpf.br

    2013-12-15

    In two recent articles, we have examined a generalization of the binomial distribution associated with a sequence of positive numbers, involving asymmetric expressions of probabilities that break the symmetry win-loss. We present in this article another generalization (always associated with a sequence of positive numbers) that preserves the symmetry win-loss. This approach is also based on generating functions and presents constraints of non-negativeness, similar to those encountered in our previous articles.

  14. MEMORANDUM FOR DISTRIBUTION

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

    * Department of Energy Washington, DC 20585 December 20, 2007 MEMORANDUM FOR DISTRIBUTION FROM: MICHAEL W. OWEN /<f /c / DIRECTOR, OFFICE OF LEGACY MANAGEM.ENT SUBJECT: Compliance with Established Policies and Guidance for Contractor Work Force Restructuring As you know, the Office of Legacy Management (LM) is the Department's fical point for all work force restructuring actions. As a reminder of policies and guidance that should continue to be followed when implementing work force

  15. Computing Frontier: Distributed Computing

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

    Computing Frontier: Distributed Computing and Facility Infrastructures Conveners: Kenneth Bloom 1 , Richard Gerber 2 1 Department of Physics and Astronomy, University of Nebraska-Lincoln 2 National Energy Research Scientific Computing Center (NERSC), Lawrence Berkeley National Laboratory 1.1 Introduction The field of particle physics has become increasingly reliant on large-scale computing resources to address the challenges of analyzing large datasets, completing specialized computations and

  16. Distributed generation implementation guidelines

    SciTech Connect (OSTI)

    Guzy, L.; O`Sullivan, J.B.; Jacobs, K.; Major, W.

    1999-11-01

    The overall economics of a distributed generation project is based on cost elements which include: Equipment and financing, fuel, displaced electricity cost, operation and maintenance. Of critical importance is how the facility is managed, including adequate provision for a comprehensive operator training program. Proper equipment maintenance and fuel procurement policy will also lead to greater system availability and optimal system economics. Various utility tariffs are available which may be economically attractive, with an added benefit to the utility of providing a peak shaving resource during peak periods. Changing modes of operation of the distributed generation system may affect staff readiness, require retraining and could affect maintenance costs. The degree of control and oversight that is provided during a project`s implementation and construction phases will impact subsequent maintenance and operating costs. The long term effect of siting impacts, such as building facades that restrict turbine inlet airflow will affect subsequent operations and require supplemental maintenance action. It is possible to site a variety of distributed generation technologies in settings which vary from urban to remote unattended locations with successful results from both an economic and operational perspective.

  17. Calibration of optical particle-size analyzer

    DOE Patents [OSTI]

    Pechin, William H.; Thacker, Louis H.; Turner, Lloyd J.

    1979-01-01

    This invention relates to a system for the calibration of an optical particle-size analyzer of the light-intercepting type for spherical particles, wherein a rotary wheel or disc is provided with radially-extending wires of differing diameters, each wire corresponding to a particular equivalent spherical particle diameter. These wires are passed at an appropriate frequency between the light source and the light detector of the analyzer. The reduction of light as received at the detector is a measure of the size of the wire, and the electronic signal may then be adjusted to provide the desired signal for corresponding spherical particles. This calibrator may be operated at any time without interrupting other processing.

  18. Quantum size effects in classical hadrodynamics

    SciTech Connect (OSTI)

    Nix, J.R.

    1994-03-01

    The author discusses future directions in the development of classical hydrodynamics for extended nucleons, corresponding to nucleons of finite size interacting with massive meson fields. This new theory provides a natural covariant microscopic approach to relativistic nucleus-nucleus collisions that includes automatically spacetime nonlocality and retardation, nonequilibrium phenomena, interactions among all nucleons, and particle production. The present version of the theory includes only the neutral scalar ({sigma}) and neutral vector ({omega}) meson fields. In the future, additional isovector pseudoscalar ({pi}{sup +}, {pi}{sup {minus}}, {pi}{sup 0}), isovector vector ({rho}{sup +}, {rho}{sup {minus}}, {rho}{sup 0}), and neutral pseudoscalar ({eta}) meson fields should be incorporated. Quantum size effects should be included in the equations of motion by use of the spreading function of Moniz and Sharp, which generates an effective nucleon mass density smeared out over a Compton wavelength. However, unlike the situation in electrodynamics, the Compton wavelength of the nucleon is small compared to its radius, so that effects due to the intrinsic size of the nucleon dominate.

  19. Sizing a New Water Heater | Department of Energy

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

    Is your water heater the right size for you house? | Photo credit ENERGY STAR Is your water heater the right size for you house? | Photo credit ENERGY STAR A properly sized ...

  20. Sizing a New Water Heater | Department of Energy

    Energy Savers [EERE]

    Heat & Cool Water Heating Sizing a New Water Heater Sizing a New Water Heater Is your water heater the right size for you house? | Photo credit ENERGY STAR Is your water ...

  1. Impact of aerosol size representation on modeling aerosol-cloud interactions

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

    Zhang, Y.; Easter, R. C.; Ghan, S. J.; Abdul-Razzak, H.

    2002-11-07

    In this study, we use a 1-D version of a climate-aerosol-chemistry model with both modal and sectional aerosol size representations to evaluate the impact of aerosol size representation on modeling aerosol-cloud interactions in shallow stratiform clouds observed during the 2nd Aerosol Characterization Experiment. Both the modal (with prognostic aerosol number and mass or prognostic aerosol number, surface area and mass, referred to as the Modal-NM and Modal-NSM) and the sectional approaches (with 12 and 36 sections) predict total number and mass for interstitial and activated particles that are generally within several percent of references from a high resolution 108-section approach.more » The modal approach with prognostic aerosol mass but diagnostic number (referred to as the Modal-M) cannot accurately predict the total particle number and surface areas, with deviations from the references ranging from 7-161%. The particle size distributions are sensitive to size representations, with normalized absolute differences of up to 12% and 37% for the 36- and 12-section approaches, and 30%, 39%, and 179% for the Modal-NSM, Modal-NM, and Modal-M, respectively. For the Modal-NSM and Modal-NM, differences from the references are primarily due to the inherent assumptions and limitations of the modal approach. In particular, they cannot resolve the abrupt size transition between the interstitial and activated aerosol fractions. For the 12- and 36-section approaches, differences are largely due to limitations of the parameterized activation for non-log-normal size distributions, plus the coarse resolution for the 12-section case. Differences are larger both with higher aerosol (i.e., less complete activation) and higher SO2 concentrations (i.e., greater modification of the initial aerosol distribution).« less

  2. Preface: Special Topic on Coarse Graining of Macromolecules, Biopolymers, and Membranes

    SciTech Connect (OSTI)

    Holm, Christian; Gompper, Gerhard; Dill, Ken A.

    2015-12-28

    This special issue highlights new developments in theory and coarse-graining in biological and synthetic macromolecules and membranes. Such approaches give unique insights into the principles and design of the structures, dynamics, and assembly processes of these complex fluids and soft materials, where the length and time scales are often prohibitively long for fully atomistic modeling.

  3. Solid State Theory of Photovoltaic Materials: Nanoscale Grain Boundaries and Doping CIGS

    SciTech Connect (OSTI)

    Zunger, A

    2005-01-01

    We use modern first-principles electronic structure theory to investigate (1) why are grain boundaries in chalcopyrites passive; (2) can chalcopyrites be doped by transition metals, and; (3) can hot electrons and carrier multiplication be efficient in quantum-dot solar cells.

  4. Farmer owned multi-use solar buildings for drying hay, grain, or heating shop

    SciTech Connect (OSTI)

    DeBusk, K.E.

    1983-06-01

    Identical multi-use solar buildings were built and tested on two farms in 1982. Actual (not simple) pay back periods are given for the two buildings for hay and for grain drying. Comparisons between solar and computed propane gas costs are reported.

  5. Nondestructive method and apparatus for imaging grains in curved surfaces of polycrystalline articles

    DOE Patents [OSTI]

    Carpenter, D.A.

    1995-05-23

    A nondestructive method, and associated apparatus, are provided for determining the grain flow of the grains in a convex curved, textured polycrystalline surface. The convex, curved surface of a polycrystalline article is aligned in a horizontal x-ray diffractometer and a monochromatic, converging x-ray beam is directed onto the curved surface of the polycrystalline article so that the converging x-ray beam is diffracted by crystallographic planes of the grains in the polycrystalline article. The diffracted x-ray beam is caused to pass through a set of horizontal, parallel slits to limit the height of the beam and thereafter. The linear intensity of the diffracted x-ray is measured, using a linear position sensitive proportional counter, as a function of position in a direction orthogonal to the counter so as to generate two dimensional data. An image of the grains in the curved surface of the polycrystalline article is provided based on the two-dimensional data. 7 Figs.

  6. Method of making metal oxide ceramic membranes with small pore sizes

    DOE Patents [OSTI]

    Anderson, Marc A. (Madison, WI); Xu, Qunyin (Madison, WI)

    1992-01-01

    A method for the production of metal oxide ceramic membranes is composed of very small pore size. The process is particularly useful in the creation of titanium and other transition metal oxide membranes. The method utilizes a sol-gel process in which the rate of particle formation is controlled by substituting a relatively large alcohol in the metal alkoxide and by limiting the available water. Stable, transparent metal oxide ceramic membranes are created having a narrow distribution of pore size, with the pore diameter being manipulable in the range of 5 to 40 Angstroms.

  7. Measuring the mass, density, and size of particles and cells using a suspended microchannel resonator

    SciTech Connect (OSTI)

    Godin, Michel; Bryan, Andrea K.; Burg, Thomas P.; Babcock, Ken; Manalis, Scott R.

    2007-09-17

    We demonstrate the measurement of mass, density, and size of cells and nanoparticles using suspended microchannel resonators. The masses of individual particles are quantified as transient frequency shifts, while the particles transit a microfluidic channel embedded in the resonating cantilever. Mass histograms resulting from these data reveal the distribution of a population of heterogeneously sized particles. Particle density is inferred from measurements made in different carrier fluids since the frequency shift for a particle is proportional to the mass difference relative to the displaced solution. We have characterized the density of polystyrene particles, Escherichia coli, and human red blood cells with a resolution down to 10{sup -4} g/cm{sup 3}.

  8. 2012 Market Report on U.S. Wind Technologies in Distributed Applicatio...

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

    An annual report on U.S. wind power in distributed applications--expanded to include small, mid-size, and utility-scale installations--including key statistics, economic data, ...

  9. 2012 Market Report on U.S. Wind Technologies in Distributed Applicatio...

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

    report on U.S. wind power in distributed applications--expanded to include small, mid-size, and utility-scale installations--including key statistics, economic data, installation, ...

  10. Real-Time Simultaneous Measurements of Size, Density, and Composition...

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

    Simultaneous Measurements of Size, Density, and Composition of Single Ultrafine Diesel Tailpipe Particles Real-Time Simultaneous Measurements of Size, Density, and Composition of ...

  11. Overview of Detailed Chemical Speciation and Particle Sizing...

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

    Detailed Chemical Speciation and Particle Sizing for Diesel Exhaust, Both Real Time and Filter Based Measurements Overview of Detailed Chemical Speciation and Particle Sizing for ...

  12. Sandia Energy - Self-Regulated Fabrication of Size-Controlled...

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

    Self-Regulated Fabrication of Size-Controlled Quantum Nanostructures Home Highlights - Energy Research Self-Regulated Fabrication of Size-Controlled Quantum Nanostructures Previous...

  13. Development of Model Filtration Media for Investigating Size...

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

    Model Filtration Media for Investigating Size-Dependent Filtration Efficiency Development of Model Filtration Media for Investigating Size-Dependent Filtration Efficiency A novel ...

  14. CBEI: Coordinating RTUs in Small and Medium Sized Commercial...

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

    Coordinating RTUs in Small and Medium Sized Commercial Buildings - 2015 Peer Review CBEI: Coordinating RTUs in Small and Medium Sized Commercial Buildings - 2015 Peer Review ...

  15. Finite-size effects of hysteretic dynamics in multilayer graphene...

    Office of Scientific and Technical Information (OSTI)

    Publisher's Accepted Manuscript: Finite-size effects of hysteretic dynamics in multilayer graphene on a ferroelectric Prev Next Title: Finite-size effects of hysteretic ...

  16. Magnetic agglomeration method for size control in the synthesis...

    Office of Scientific and Technical Information (OSTI)

    Magnetic agglomeration method for size control in the synthesis of magnetic nanoparticles Title: Magnetic agglomeration method for size control in the synthesis of magnetic ...

  17. Theoretical investigation of the impact of grain boundaries and fission gases on UO2 thermal conductivity

    SciTech Connect (OSTI)

    Du, Shiyu; Andersson, Anders D.; Germann, Timothy C.; Stanek, Christopher R.

    2012-05-02

    Thermal conductivity is one of the most important metrics of nuclear fuel performance. Therefore, it is crucial to understand the impact of microstructure features on thermal conductivity, especially since the microstructure evolves with burn-up or time in the reactor. For example, UO{sub 2} fuels are polycrystalline and for high-burnup fuels the outer parts of the pellet experience grain sub-division leading to a very fine grain structure. This is known to impact important physical properties such as thermal conductivity as fission gas release. In a previous study, we calculated the effect of different types of {Sigma}5 grain boundaries on UO{sub 2} thermal conductivity and predicted the corresponding Kapitza resistances, i.e. the resistance of the grain boundary in relation to the bulk thermal resistance. There have been reports of pseudoanisotropic effects for the thermal conductivity in cubic polycrystalline materials, as obtained from molecular dynamics simulations, which means that the conductivity appears to be a function of the crystallographic direction of the temperature gradient. However, materials with cubic symmetry should have isotropic thermal conductivity. For this reason it is necessary to determine the cause of this apparent anisotropy and in this report we investigate this effect in context of our earlier simulations of UO{sub 2} Kapitza resistances. Another source of thermal resistance comes from fission products and fission gases. Xe is the main fission gas and when generated in sufficient quantity it dissolves from the lattice and forms gas bubbles inside the crystalline structure. We have performed studies of how Xe atoms dissolved in the UO{sub 2} matrix or precipitated as bubbles impact thermal conductivity, both in bulk UO{sub 2} and in the presence of grain boundaries.

  18. Distributed Optimization System

    DOE Patents [OSTI]

    Hurtado, John E.; Dohrmann, Clark R.; Robinett, III, Rush D.

    2004-11-30

    A search system and method for controlling multiple agents to optimize an objective using distributed sensing and cooperative control. The search agent can be one or more physical agents, such as a robot, and can be software agents for searching cyberspace. The objective can be: chemical sources, temperature sources, radiation sources, light sources, evaders, trespassers, explosive sources, time dependent sources, time independent sources, function surfaces, maximization points, minimization points, and optimal control of a system such as a communication system, an economy, a crane, and a multi-processor computer.

  19. Spark Distributed Analytic Framework

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

    Apache Spark Spark Distributed Analytic Framework Description and Overview Apache Spark(tm) is a fast and general engine for large-scale data processing. How to Use Spark Because of its high memory and I/O bandwidth requirements, we recommend you run your spark jobs on Cori. Follow the steps below to use spark, note that the order of the commands matters. DO NOT load the spark module until you are inside a batch job. Interactive mode Submit an interactive batch job with at least 2 nodes: salloc

  20. Impact of Increasing Distributed Wind Power and Wind Turbine Siting on Rural Distribution Feeder Voltage Profiles: Preprint

    SciTech Connect (OSTI)

    Allen, A.; Zhang, Y. C.; Hodge, B. M.

    2013-09-01

    Many favorable wind energy resources in North America are located in remote locations without direct access to the transmission grid. Building transmission lines to connect remotely-located wind power plants to large load centers has become a barrier to increasing wind power penetration in North America. By connecting utility-sized megawatt-scale wind turbines to the distribution system, wind power supplied to consumers could be increased greatly. However, the impact of including megawatt-scale wind turbines on distribution feeders needs to be studied. The work presented here examined the impact that siting and power output of megawatt-scale wind turbines have on distribution feeder voltage. This is the start of work to present a general guide to megawatt-scale wind turbine impact on the distribution feeder and finding the amount of wind power that can be added without adversely impacting the distribution feeder operation, reliability, and power quality.