Sample records for grain size distribution

  1. Grain-size distributions of tsunami sediments

    E-Print Network [OSTI]

    Spencer, Sarah

    2011-08-08T23:59:59.000Z

    of tsunamis. By implementing the use of simulation and modeling the tsunami depositional process may be fully understood. The program Python with PyLab was used to form distributions and calculate descriptive parameters with grain-size data from two past...

  2. Grain size, size-distribution and dislocation structure from diffraction peak profile analysis

    E-Print Network [OSTI]

    Gubicza, Jenõ

    Grain size, size-distribution and dislocation structure from diffraction peak profile analysis T, Budapest, Hungary Abstract Diffraction peak profile analysis (or Line Profile Analysis, LPA) has recently and the strain diffraction profiles. Strain anisotropy is rationalized in terms of the contrast factors

  3. Solitary dust sound waves in a plasma with two-temperature ions and distributed grain size

    SciTech Connect (OSTI)

    Prudskikh, V. V. [Southern Federal University, Research Institute of Physics (Russian Federation)

    2009-01-15T23:59:59.000Z

    The propagation of weakly nonlinear dust sound waves in a dusty plasma containing two different-temperature ion species is explored. The nonlinear equations describing both the quadratic and cubic plasma nonlinearities are derived. It is shown that the properties of dust sound waves depend substantially on the grain size distribution. In particular, for solitary dust sound waves with a positive potential to exist in a plasma with distributed grain size, it is necessary that the difference between the temperatures of two ion species be larger than that in the case of equal-size grains.

  4. Notes on representing grain size distributions obtained by electron backscatter diffraction

    SciTech Connect (OSTI)

    Toth, Laszlo S., E-mail: laszlo.metz@univ-lorraine.fr [Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3), UMR 7239, CNRS/Université de Lorraine, F-57045 Metz (France); Laboratory of Excellence on Design of Alloy Metals for low-mAss Structures (DAMAS), Université de Lorraine (France); Biswas, Somjeet, E-mail: somjeetbiswas@gmail.com [Laboratory of Excellence on Design of Alloy Metals for low-mAss Structures (DAMAS), Université de Lorraine (France); Gu, Chengfan, E-mail: chengfan.gu@unsw.edu.au [School of Materials Science and Engineering, The University of New South Wales, Sydney, NSW 2052 (Australia); Beausir, Benoit, E-mail: benoit.beausir@univ-lorraine.fr [Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3), UMR 7239, CNRS/Université de Lorraine, F-57045 Metz (France); Laboratory of Excellence on Design of Alloy Metals for low-mAss Structures (DAMAS), Université de Lorraine (France)

    2013-10-15T23:59:59.000Z

    Grain size distributions measured by electron backscatter diffraction are commonly represented by histograms using either number or area fraction definitions. It is shown here that they should be presented in forms of density distribution functions for direct quantitative comparisons between different measurements. Here we make an interpretation of the frequently seen parabolic tales of the area distributions of bimodal grain structures and a transformation formula between the two distributions are given in this paper. - Highlights: • Grain size distributions are represented by density functions. • The parabolic tales corresponds to equal number of grains in a bin of the histogram. • A simple transformation formula is given to number and area weighed distributions. • The particularities of uniform and lognormal distributions are examined.

  5. The effect of sand grain size distribution on the minimum oil saturation necessary to support in-situ combustion

    E-Print Network [OSTI]

    Daniel, William Marvin

    1973-01-01T23:59:59.000Z

    THE EFFECT OF SAND GRAIN SIZE DISTRIBUTION ON THE MINIMUM OIL SATURATION NECESSARY TO SUPPORT IN-SITU COMBUSTION A Thesis by WILLIAM MARVIN DANIEL Submitted to the Graduate College of Texas ARM University in partial fulfillment... of the requirement for the degree of MASTER OF SCIENCE May 1973 Major Subject: Petroleum. Engineering THE EFFECT OF SAND GRAIN SIZE DISTRIBUTION ON THE MINIMUM OIL SATURATION NECESSARY TO SUPPORT IN-SITU COMBUSTION A Thesis by WILLIAM MARVIN DANIEL Approved...

  6. Solitary Dust--Acoustic Waves in a Plasma with Two-Temperature Ions and Distributed Grain Size

    E-Print Network [OSTI]

    V. V. Prudskikh

    2008-12-02T23:59:59.000Z

    The propagation of weakly nonlinear dust--acoustic waves in a dusty plasma containing two ion species with different temperatures is explored. The nonlinear equations describing both the quadratic and cubic plasma nonlinearities are derived. It is shown that the properties of dust--acoustic waves depend substantially on the grain size distribution. In particular, for solitary dust--acoustic waves with a positive potential to exist in a plasma with distributed grain size, it is necessary that the difference between the temperatures of two ion species be large that that in the case of unusized grains.

  7. The environment of a geomaterial (soil, rock, concrete) determines its susceptibility to failure: grain size distribution and mineralogy, fluid-saturation, pore fluid chemistry, current state of stress, history, the

    E-Print Network [OSTI]

    Borja, Ronaldo I.

    to failure: grain size distribution and mineralogy, fluid-saturation, pore fluid chemistry, current state

  8. 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)

    2013-09-01T23:59:59.000Z

    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 external galaxies.

  9. Grain size effects on the fatigue response of nanocrystalline materials

    E-Print Network [OSTI]

    Hanlon, Timothy, 1977-

    2004-01-01T23:59:59.000Z

    The resistance of metals and alloys to fatigue crack initiation and propagation is known to be influenced significantly by grain size. Based on a wealth of experimental results obtained from microcrystalline metals, where ...

  10. Size-dependent same-material tribocharging in insulating grains

    E-Print Network [OSTI]

    Scott R. Waitukaitis; Victor Lee; James M. Pierson; Steven L. Forman; Heinrich M. Jaeger

    2014-08-07T23:59:59.000Z

    Observations of flowing granular matter have suggested that same-material tribocharging de- pends on particle size, rendering large grains positive and small ones negative. Models assuming the transfer of trapped electrons can explain this, but so far have not been validated. Tracking individual grains in an electric field, we show quantitatively that charge is transferred based on size between materially identical grains. However, the surface density of trapped electrons, measured independently by thermoluminescence techniques, is orders of magnitude too small to account for the scale of charge transferred. This suggests that another negatively charged species, such as ions, is responsible.

  11. Effect of Grain Size on Uranium(VI) Surface Complexation Kinetics...

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

    Grain Size on Uranium(VI) Surface Complexation Kinetics and Adsorption Additivity. Effect of Grain Size on Uranium(VI) Surface Complexation Kinetics and Adsorption Additivity....

  12. Effects of particle size on digestion of sorghum grains

    E-Print Network [OSTI]

    Walker, Reuben Don

    1972-01-01T23:59:59.000Z

    EFFECTS OF PARTICIE SIZE ON DIGESTION OF SORGJJJJJJ GRAINS A Thesis by REUBEN DON WALKER Submitted to the Grariuate College of Texas Af. N University in partial f'ulfillment of the requirement for the degree cf K&TER OF SCIENCE Decembe. r... 19!2 Flajor Subjert; Animal Nutrition EFFECTS OF 1'ARTICLE SIZE ON DIGESTION OF SORGHUM GRAINS A Thesis REUBEN DON WALKER Approved as to style and content by: (Chai n of Committee) (Bead or Doper ment) c (Member) , 'j ji i (Member) Deceu...

  13. Is the silicate emission feature only influenced by grain size?

    E-Print Network [OSTI]

    N. V. Voshchinnikov; Th. Henning

    2008-03-31T23:59:59.000Z

    The flattening of the 10mu silicate emission feature observed in the spectra of T Tauri and Herbig Ae/Be stars is usually interpreted as an indicator of grain growth. We show in this paper that a similar behaviour of the feature shape occurs when the porosity of composite grains varies. The fluffy aggregates, having inclusions of different sizes, were modeled by multi-layered spheres consisting of amorphous carbon, amorphous silicate and vacuum. It is also found that the inclusion of crystalline silicates in composite porous particles can lead to a shift of the known resonances and production of new ones.

  14. Estimating quality factor and mean grain size of sediments from high-resolution marine seismic data

    E-Print Network [OSTI]

    National Oceanography Centre Southampton

    model of quality factor against mean grain size from published sediment studies, the mean grain sizes with frequency. The Biot-Stoll model shows a marked velocity dispersion and nonlinear transition in compressionalEstimating quality factor and mean grain size of sediments from high-resolution marine seismic data

  15. ARM - Measurement - Hydrometeor Size Distribution

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP : XDC documentationBarrow,ice particleSize Distribution ARM Data

  16. EFFECT OF GRAIN SIZE ON THE ACOUSTIC EMISSION GENERATED DURING PLASTIC DEFORMATION OF ALUMINUM

    E-Print Network [OSTI]

    Baram, J.

    2013-01-01T23:59:59.000Z

    PLASTIC DEFORMATION OF ALUMINUM LAWRENCE BERKELEY LABORATORYDURING PLASTIC DEFORMATION OF ALUMINUM J. Baram Materialsof polycrystalline aluminum, of different grain sizes and at

  17. The Relationship Between Grain Boundary Energy, Grain Boundary Complexion Transitions, and Grain Size in Ca-doped Yttria

    E-Print Network [OSTI]

    Rohrer, Gregory S.

    The Relationship Between Grain Boundary Energy, Grain Boundary Complexion Transitions, and Grain complexions. One idea is that complexion transitions occur to lower the average energy of the interface energy. Experiments on doped aluminas have shown that a complexion transition can change the relative

  18. Influence of Ba content on grain size and dynamics of crystallization in barium ferrite thin films

    E-Print Network [OSTI]

    Laughlin, David E.

    Influence of Ba content on grain size and dynamics of crystallization in barium ferrite thin films of the crystallization process, which ultimately determines the grain size, were studied in barium ferrite thin films. Rapid thermal annealing was used to crystallize the amorphous as-deposited barium ferrite films

  19. Effect of grain size on the melting point of confined thin aluminum films

    SciTech Connect (OSTI)

    Wejrzanowski, Tomasz; Lewandowska, Malgorzata; Sikorski, Krzysztof; Kurzydlowski, Krzysztof J. [Materials Design Division, Faculty of Materials Science and Engineering, Warsaw University of Technology, Woloska 141, 02-507 Warsaw (Poland)

    2014-10-28T23:59:59.000Z

    The melting of aluminum thin film was studied by a molecular dynamics (MD) simulation technique. The effect of the grain size and type of confinement was investigated for aluminum film with a constant thickness of 4?nm. The results show that coherent intercrystalline interface suppress the transition of solid aluminum into liquid, while free-surface gives melting point depression. The mechanism of melting of polycrystalline aluminum thin film was investigated. It was found that melting starts at grain boundaries and propagates to grain interiors. The melting point was calculated from the Lindemann index criterion, taking into account only atoms near to grain boundaries. This made it possible to extend melting point calculations to bigger grains, which require a long time (in the MD scale) to be fully molten. The results show that 4?nm thick film of aluminum melts at a temperature lower than the melting point of bulk aluminum (933?K) only when the grain size is reduced to 6?nm.

  20. Effects of particle size on digestion of sorghum grains 

    E-Print Network [OSTI]

    Walker, Reuben Don

    1972-01-01T23:59:59.000Z

    will depend on the supply of sorghum or other feed grains. Its feeding value for ruminants is consistently 92-95/ that of corn, which is reflected in slightly lower gains, increased feed requirements and lower returns for the sorghum based rations. Effic...

  1. Nanostructured Ni-Co Alloys with Tailorable Grain Size and Twin Density

    E-Print Network [OSTI]

    Ferreira, Paulo J.

    grain sizes and twin densities in the Ni-Co binary system. Using electrodeposition with various applied nanocrystalline nickel. I. INTRODUCTION BULK nanocrystalline materials are characterized by a large volume

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

    DOE Patents [OSTI]

    Maris, Humphrey J (Barrington, RI)

    2001-01-01T23:59:59.000Z

    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 (Barrington, RI)

    2000-01-01T23:59:59.000Z

    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. Selected room temperature magnetic parameters as a function of mineralogy, concentration and grain size

    E-Print Network [OSTI]

    Utrecht, Universiteit

    goethite are recognised by their high (remanent) coercivities. The ratio of saturation remanent with increasing grain size for sizes larger than one micrometer. In contrast, the coercivity of goethite showed of the iron oxides magnetite, titanomagnetite, maghemite and he- matite, the iron oxyhydroxide goethite

  5. The Time Evolution of Aerosol Size Distribution Over the Mexico...

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

    Size Distribution Over the Mexico City Plateau. The Time Evolution of Aerosol Size Distribution Over the Mexico City Plateau. Abstract: As part of the MILAGRO field campaign, the...

  6. 7, 1074310766, 2007 EC size distributions

    E-Print Network [OSTI]

    Boyer, Edmond

    carbon in a coastal urban atmosphere in South China: characteristics, evolution processesACPD 7, 10743­10766, 2007 EC size distributions in an urban atmosphere in China Xiao-Feng Huang, Kowloon, Hong Kong, China Received: 30 May 2007 ­ Accepted: 19 July 2007 ­ Published: 25 July 2007

  7. 5, 1012510154, 2005 Size distributions of

    E-Print Network [OSTI]

    Boyer, Edmond

    ·veh). The separation of the emission factor into passenger cars20 ((5.8±2)·1013 #/(km·veh)) and trucks ((2.5±0.9)·1015 #/(km·veh)) yielded in a 40-times higher emission factor for trucks compared to passenger cars. 1ACPD 5, 10125­10154, 2005 Size distributions of soot particles and emission factors D. Rose et al

  8. 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)

    2014-07-28T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Ishak-Boushaki, M.; Djellout, D.; Annou, R. [Faculty of Physics, USTHB, P.B. 32 El Alia, Bab-ezzouar, Algiers (Algeria)

    2012-07-15T23:59:59.000Z

    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.

  10. Barium ferrite thin film media with perpendicular c-axis orientation and small grain size

    E-Print Network [OSTI]

    Laughlin, David E.

    Barium ferrite thin film media with perpendicular c-axis orientation and small grain size Zailong, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 Barium ferrite thin films with perpendicular c conditions. The c-axis orientation of barium ferrite thin films is most sensitive to the oxygen partial

  11. Particle size distribution of indoor aerosol sources

    SciTech Connect (OSTI)

    Shah, K.B.

    1990-10-24T23:59:59.000Z

    As concern about Indoor Air Quality (IAQ) has grown in recent years, it has become necessary to determine the nature of particles produced by different indoor aerosol sources and the typical concentration that these sources tend to produce. These data are important in predicting the dose of particles to people exposed to these sources and it will also enable us to take effective mitigation procedures. Further, it will also help in designing appropriate air cleaners. A new state of the art technique, DMPS (Differential Mobility Particle Sizer) System is used to determine the particle size distributions of a number of sources. This system employs the electrical mobility characteristics of these particles and is very effective in the 0.01--1.0 {mu}m size range. A modified system that can measure particle sizes in the lower size range down to 3 nm was also used. Experimental results for various aerosol sources is presented in the ensuing chapters. 37 refs., 20 figs., 2 tabs.

  12. 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

    2006-10-31T23:59:59.000Z

    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.

  13. The evolution of texture and grain size during annealing of nanocrystalline Ni-45% Fe electrodeposits

    SciTech Connect (OSTI)

    Czerwinski, F.; Li, H.; Megret, M.; Szpunar, J.A. [McGill Univ., Montreal, Quebec (Canada). Dept. of Metallurgical Engineering] [McGill Univ., Montreal, Quebec (Canada). Dept. of Metallurgical Engineering; Clark, D.G.; Erb, U. [Queen`s Univ., Kingston, Ontario (Canada). Dept. of Materials and Metallurgical Engineering] [Queen`s Univ., Kingston, Ontario (Canada). Dept. of Materials and Metallurgical Engineering

    1997-12-15T23:59:59.000Z

    The study of thermal stability of nanocrystalline materials is of great importance for the general assessment of potential technological applications. This is especially true for nanocrystals obtained by electrodeposition. A high electrode polarization, usually used during electrodeposition to reduce grain size, produces materials that are not in a state of equilibrium. This results in a large driving force for grain growth at elevated temperatures. The purpose of this investigation is to examine the thermal stability of nanocrystalline Ni-45 wt.% Fe alloy produced by electrodeposition. Of particular interest is the evolution of texture during annealing and the change of hardness.

  14. Downstream patterns of bed material grain size in a large, lowland alluvial river subject to low sediment supply

    E-Print Network [OSTI]

    California at Santa Barbara, University of

    Downstream patterns of bed material grain size in a large, lowland alluvial river subject to low. The data also show that tributaries have a minor impact on main stem downstream fining due to basin shape of downstream fining. Citation: Singer, M. B. (2008), Downstream patterns of bed material grain size in a large

  15. Parameterizing Size Distribution in Ice Clouds

    SciTech Connect (OSTI)

    DeSlover, Daniel; Mitchell, David L.

    2009-09-25T23:59:59.000Z

    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 µm) 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 µm), known as the “small mode”. Rather than using in situ probe measurements aboard aircraft, we employed a treatment of ice cloud optical properties formulated in terms of PSD parameters in combination with remote measurements of thermal radiances to characterize the small mode. This is possible since the absorption efficiency (Qabs) of small mode crystals is larger at 12 µm wavelength relative to 11 µm wavelength due to the process of wave resonance or photon tunneling more active at 12 µm. This makes the 12/11 µm absorption optical depth ratio (or equivalently the 12/11 µm Qabs ratio) a means for detecting the relative concentration of small ice particles in cirrus. Using this principle, this project tested and developed PSD schemes that can help characterize cirrus clouds at each of the three ARM sites: SGP, NSA and TWP. This was the main effort of this project. These PSD schemes and ice sedimentation velocities predicted from them have been used to test the new cirrus microphysics parameterization in the GCM known as the Community Climate Systems Model (CCSM) as part of an ongoing collaboration with NCAR. Regarding the second problem, we developed and did preliminary testing on a passive thermal method for retrieving the total water path (TWP) of Arctic mixed phase clouds where TWPs are often in the range of 20 to 130 g m-2 (difficult for microwave radiometers to accurately measure). We also developed a new radar method for retrieving the cloud ice water content (IWC), which can be vertically integrated to yield the ice water path (IWP). These techniques were combined to determine the IWP and liquid water path (LWP) in Arctic clouds, and hence the fraction of ice and liquid water. We have tested this approach using a case study from the ARM field campaign called M-PACE (Mixed-Phase Arctic Cloud Experiment). This research led to a new satellite remote sensing method that appears promising for detecting low levels of liquid water in high clouds typically between -20 and -36 oC. We hope to develop this method in future research.

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

    SciTech Connect (OSTI)

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

    2012-01-01T23:59:59.000Z

    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 pores that was inaccessible was not rank dependent. In the Australian coals, at the 10 nm to 50 nm size scales the pores in inertinites appeared to be completely accessible to CD{sub 4}, whereas the pores in the vitrinite were about 75% inaccessible. Unlike the results for total porosity that showed no regional effects on relationships between porosity and coal properties, clear regional differences in the relationships between fraction of closed porosity and coal properties were found. The 10 to 50 nm-sized pores of inertinites of the US and Polish coals examined appeared less accessible to methane than those of the inertinites of Australian coals. This difference in pore accessibility in inertinites may explain why empirical relationships between fluidity and coking properties developed using Carboniferous coals do not apply to Australian coals.

  17. Size-independent vs. size-dependent policies in scheduling heavy-tailed distributions

    E-Print Network [OSTI]

    Nham, John (John T.)

    2008-01-01T23:59:59.000Z

    We study the problem of scheduling jobs on a two-machine distributed server, where the job size distribution is heavy-tailed. We focus on two distributions, for which we prove that the performance of the optimal size-independent ...

  18. activity size distributions: Topics by E-print Network

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

    of nutrients increased Mazumder, Asit 33 A COMPOSITE SOURCE MODEL WITH FRACTAL SUBEVENT SIZE DISTRIBUTION Geosciences Websites Summary: A COMPOSITE SOURCE MODEL WITH FRACTAL...

  19. activity size distribution: Topics by E-print Network

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

    of nutrients increased Mazumder, Asit 33 A COMPOSITE SOURCE MODEL WITH FRACTAL SUBEVENT SIZE DISTRIBUTION Geosciences Websites Summary: A COMPOSITE SOURCE MODEL WITH FRACTAL...

  20. Spectral Energy Distributions of T Tauri and Herbig Ae Disks: Grain Mineralogy, Parameter Dependences, and Comparison with ISO LWS Observations

    E-Print Network [OSTI]

    E. I. Chiang; M. K. Joung; M. J. Creech-Eakman; C. Qi; J. E. Kessler; G. A. Blake; E. F. van Dishoeck

    2000-09-26T23:59:59.000Z

    We improve upon the radiative, hydrostatic equilibrium models of passive circumstellar disks constructed by Chiang & Goldreich (1997). New features include (1) account for a range of particle sizes, (2) employment of laboratory-based optical constants of representative grain materials, and (3) numerical solution of the equations of radiative and hydrostatic equilibrium within the original 2-layer (disk surface + disk interior) approximation. We explore how the spectral energy distribution (SED) of a face-on disk depends on grain size distributions, disk geometries and surface densities, and stellar photospheric temperatures. Observed SEDs of 3 Herbig Ae and 2 T Tauri stars, including spectra from the Long Wavelength Spectrometer (LWS) aboard the Infrared Space Observatory (ISO), are fitted with our models. Silicate emission bands from optically thin, superheated disk surface layers appear in nearly all systems. Water ice emission bands appear in LWS spectra of 2 of the coolest stars. Infrared excesses in several sources are consistent with vertical settling of photospheric grains. While this work furnishes further evidence that passive reprocessing of starlight by flared disks adequately explains the origin of infrared-to-millimeter wavelength excesses of young stars, we emphasize how the SED alone does not provide sufficient information to constrain particle sizes and disk masses uniquely.

  1. ARM - Measurement - Aerosol particle size distribution

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP : XDC documentationBarrow, AlaskaWhenimage ARM Dataparticle size

  2. INITIAL PLANETESIMAL SIZES AND THE SIZE DISTRIBUTION OF SMALL KUIPER BELT OBJECTS

    SciTech Connect (OSTI)

    Schlichting, Hilke E. [UCLA, Department of Earth and Space Science, 595 Charles E. Young Drive East, Los Angeles, CA 90095 (United States); Fuentes, Cesar I.; Trilling, David E., E-mail: hilke@ucla.edu [Department of Physics and Astronomy, Northern Arizona University, P.O. Box 6010, Flagstaff, AZ 86011 (United States)

    2013-08-01T23:59:59.000Z

    The Kuiper Belt is a remnant from the early solar system and its size distribution contains many important constraints that can be used to test models of planet formation and collisional evolution. We show, by comparing observations with theoretical models, that the observed Kuiper Belt size distribution is well matched by coagulation models, which start with an initial planetesimal population with radii of about 1 km, and subsequent collisional evolution. We find that the observed size distribution above R {approx} 30 km is primordial, i.e., it has not been modified by collisional evolution over the age of the solar system, and that the size distribution below R {approx} 30 km has been modified by collisions and that its slope is well matched by collisional evolution models that use published strength laws. We investigate in detail the resulting size distribution of bodies ranging from 0.01 km to 30 km and find that its slope changes several times as a function of radius before approaching the expected value for an equilibrium collisional cascade of material strength dominated bodies for R {approx}< 0.1 km. Compared to a single power-law size distribution that would span the whole range from 0.01 km to 30 km, we find in general a strong deficit of bodies around R {approx} 10 km and a strong excess of bodies around 2 km in radius. This deficit and excess of bodies are caused by the planetesimal size distribution left over from the runaway growth phase, which left most of the initial mass in small planetesimals while only a small fraction of the total mass is converted into large protoplanets. This excess mass in small planetesimals leaves a permanent signature in the size distribution of small bodies that is not erased after 4.5 Gyr of collisional evolution. Observations of the small Kuiper Belt Object (KBO) size distribution can therefore test if large KBOs grew as a result of runaway growth and constrained the initial planetesimal sizes. We find that results from recent KBO occultation surveys and the observed KBO size distribution can be best matched by an initial planetesimal population that contained about equal mass per logarithmic mass bin in bodies ranging from 0.4 km to 4 km in radius. We further find that we cannot match the observed KBO size distribution if most of the planetesimal mass was contained in bodies that were 10 km in radius or larger simply because their resulting size distribution cannot be sufficiently depleted over 4.5 Gyr to match observations.

  3. Speciation and distribution of arsenic and localization of nutrients in rice grains

    SciTech Connect (OSTI)

    Lombi, E.; Scheckel, K.G.; Pallon, J.; Carey, A.M.; Zhu, Y.G.; Meharg, A.A. (EPA); (UCopenhagen); (Aberdeen); (Lund); (Chinese Aca. Sci.)

    2012-09-05T23:59:59.000Z

    Arsenic (As) contamination of rice grains and the generally low concentration of micronutrients in rice have been recognized as a major concern for human health. Here, we investigated the speciation and localization of As and the distribution of (micro)nutrients in rice grains because these are key factors controlling bioavailability of nutrients and contaminants. Bulk total and speciation analyses using high-pressure liquid chromatography (HPLC)-inductively coupled plasma mass spectrometry (ICP-MS) and X-ray absorption near-edge spectroscopy (XANES) was complemented by spatially resolved microspectroscopic techniques ({mu}-XANES, {mu}-X-ray fluorescence ({mu}-XRF) and particle induced X-ray emission (PIXE)) to investigate both speciation and distribution of As and localization of nutrients in situ. The distribution of As and micronutrients varied between the various parts of the grains (husk, bran and endosperm) and was characterized by element-specific distribution patterns. The speciation of As in bran and endosperm was dominated by As(III)-thiol complexes. The results indicate that the translocation from the maternal to filial tissues may be a bottleneck for As accumulation in the grain. Strong similarities between the distribution of iron (Fe), manganese (Mn) and phosphorus (P) and between zinc (Zn) and sulphur (S) may be indicative of complexation mechanisms in rice grains.

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

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

    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...

  5. Dust size distribution and concentrations with cottonseed oil mills

    E-Print Network [OSTI]

    Wiederhold, Lee Roy

    1976-01-01T23:59:59.000Z

    DUST SIZE DISTRIBUTION AND CONCENTRATIONS WITHIN COTTONSEED OIL MILLS A Thesis by LEE ROY WIEDERHOLD, JR. / I Submitted to the Graduate College of Texas ARM University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE August 1976 Major Subject: Aqricultural Engineering DUST SIZE DISTRIBUTION AND CONCENTRATIONS WITHIN COTTONSEED OIL MILLS A Thesis by LEE ROY WIEDERHOLD, JR. Approved as to style and content by: Chairman of Committee ~Hd fdp t Member ber...

  6. Modeling the formation and size distribution of fly ash

    SciTech Connect (OSTI)

    Dahlin, R.S.

    1985-01-01T23:59:59.000Z

    A set of mathematical models has been developed to predict the size distribution of fly ash particles formed in pulverized coal combustion. The large particle mode of the size distribution, typically centered about 10 to 20 ..mu..m, is predicted by a simple breakup model that is based on the complete coalescence of molten mineral inclusions within fragments of the devolatilized coal char. The ultrafine particle mode, that is typically centered about 0.1 to 0.2 ..mu..m, is modeled in terms of ash volatilization, nucleation, and coagulation. Silica and alumina are reduced to volatile suboxides through reactions at the char surface. The volatile suboxides are transported from the char surface where they are oxidized back to the stable oxides in the bulk gas, and then nucleated in accordance with homogeneous nucleation theory. The ultrafine nuclei coagulate in accordance with Brownian coagulation theory. The predicted particle size spectra have been compared to measured size distributions from a pilot-scale combustor and a full-scale utility boiler. Considering the disproportionate loss of coarse particles in the pilot-scale unit, the agreement between the predicted and measured size distributions was considered reasonably good. Both the predicted ultrafine and large particle modes agreed reasonably well with the measured particle size distribution for the full scale boiler. The validated computer models were used to study the effect of changes in the coal ash content, coal particle size, and the combustion flame temperature.

  7. Atomically flat La-silicate/Si interface using tungsten carbide gate electrode with nano-sized grain

    SciTech Connect (OSTI)

    Tuokedaerhan, K.; Natori, K.; Iwai, H. [Frontier Research Center, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503 (Japan); Kakushima, K., E-mail: kakushima@ep.titech.ac.jp; Kataoka, Y.; Nishiyama, A.; Sugii, N.; Wakabayashi, H.; Tsutsui, K. [Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502 (Japan)

    2014-01-13T23:59:59.000Z

    Interface properties of La-silicate gate dielectrics on Si substrates with W or nano-sized grain W{sub 2}C gate electrodes have been investigated. A low interface state density of 2.5?×?10{sup 11}?cm{sup ?2}/eV has been achieved with W{sub 2}C gate electrodes, which is one third of those with W gate electrode. An interface roughness of 0.33?nm with spatial frequency comparable to the grain size of W gate electrode has been observed. Besides, an atomically flat interface of 0.12?nm has been obtained with W{sub 2}C gate electrode. The origin of flat interface may be attributed to the elimination of inhomogeneous stress by grains in metal electrode.

  8. Evolution of particle size distribution after the CFFF secondary combustor

    SciTech Connect (OSTI)

    Yang, Dujiu; Crawford, L.W.

    1993-06-01T23:59:59.000Z

    Particle size distribution after the CFFF secondary combustor is studied in this paper. As an important mechanism of particle collision, thermophoresis is briefly discussed in this paper and the thermophoretic velocity is given. The temperature gradient that causes the thermophoretic force is established between high and low temperature particles in the flow, which results from convection and radiation heat balance between particles and wall. Particle temperature with respect to their sizes is obtained. Mechanism of agglomeration and collection efficiency of fine particles is presented. Finally, at the inlet of the ESP, theoretical particle size distribution is compared with the experimental measurements at CFFF.

  9. Evolution of particle size distribution after the CFFF secondary combustor

    SciTech Connect (OSTI)

    Yang, Dujiu; Crawford, L.W.

    1993-01-01T23:59:59.000Z

    Particle size distribution after the CFFF secondary combustor is studied in this paper. As an important mechanism of particle collision, thermophoresis is briefly discussed in this paper and the thermophoretic velocity is given. The temperature gradient that causes the thermophoretic force is established between high and low temperature particles in the flow, which results from convection and radiation heat balance between particles and wall. Particle temperature with respect to their sizes is obtained. Mechanism of agglomeration and collection efficiency of fine particles is presented. Finally, at the inlet of the ESP, theoretical particle size distribution is compared with the experimental measurements at CFFF.

  10. ESTIMATION OF MATRIX BLOCK SIZE DISTRIBUTION IN NATURALLY FRACTURED RESERVOIRS

    E-Print Network [OSTI]

    Stanford University

    ESTIMATION OF MATRIX BLOCK SIZE DISTRIBUTION IN NATURALLY FRACTURED RESERVOIRS A Report Submitted;2 ABSTRACT Interporosity flow in a naturslly fractured reservoir is modelled by a new formulation of the distribution. Thus, observed pressure response from fractured reservoirs can be analysed to obtain the matrix

  11. Sedimentation of algae: relationships with biomass and size distribution1

    E-Print Network [OSTI]

    Mazumder, Asit

    Sedimentation of algae: relationships with biomass and size distribution1 Isabelle Larocque, A distribution of epilimnetic algae on patterns of algal sedimentation was determined in lake enclosures under the mean length of algae in fish-free enclosures and reduced the mean length in the enclosures to which

  12. 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

    2014-06-01T23:59:59.000Z

    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.

  13. Effect of Y-211 particle size on the growth of single grain Y–Ba–Cu–O bulk superconductors

    E-Print Network [OSTI]

    Thoma, Max; Shi, Yunhua; Dennis, Tony; Durrell, John; Cardwell, David

    2014-12-01T23:59:59.000Z

    The engineering of fine Y2Ba1Cu1O5 (Y-211) inclusions of average particle size 1?2 ?m within the continuous, superconducting YBa2Cu3O7?? (Y-123) phase matrix of single-grain, bulk high temperature Y–Ba–Cu–O (YBCO) superconductors is fundamental...

  14. Grain size softening effect in Al{sub 62.5}Cu{sub 25}Fe{sub 12.5} nanoquasicrystals

    SciTech Connect (OSTI)

    Mukhopadhyay, N. K., E-mail: mukho.nk@gmail.com [Department of Metallurgical Engineering, Indian Institute of Technology (BHU), Varanasi 221 005 (India); Ali, F., E-mail: fahadali62@hotmail.com [Pakistan Institute of Engineering and Applied Science, P.O. Nilore, Islamabad (Pakistan); Scudino, S., E-mail: S.Scudino@ifw-dresden.de; Samadi Khoshkhoo, M., E-mail: m.samadi.khoshkhoo@ifw-dresden.de; Stoica, M., E-mail: M.Stoica@ifw-dresden.de [IFW Dresden, Institut für Komplexe Materialien, Postfach 27 01 16, D-01171 Dresden (Germany); Srivastava, V. C., E-mail: vcsrivas@gmail.com [Metal Extraction and Forming Division, National Metallurgical Laboratory, Jamshedpur 831007 (India); Uhlenwinkel, V., E-mail: uhl@iwt.uni-bremen.de [Institut für Werkstofftechnik, Universität Bremen, Badgasteiner Str. 3, D-28359 Bremen (Germany); Vaughan, G., E-mail: vaughan@esrf.fr [European Synchrotron Radiation Facilities ESRF, BP 220, 38043 Grenoble (France); Suryanarayana, C., E-mail: Surya@ucf.edu [Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, Florida 32816-2450 (United States); Eckert, J., E-mail: J.Eckert@ifw-dresden.de [IFW Dresden, Institut für Komplexe Materialien, Postfach 27 01 16, D-01171 Dresden (Germany); TU Dresden, Institut für Werkstoffwissenschaft, D-01062 Dresden (Germany)

    2013-11-11T23:59:59.000Z

    Inverse Hall-Petch (IHP) behavior in nano-quasicrystalline Al{sub 62.5}Cu{sub 25}Fe{sub 12.5} is reported. Powders with varying grain sizes were produced by mechanical milling of spray-formed quasicrystals. The hardness of the milled powders increased with decreasing grain size down to about 40?nm and decreased with further refinement, demonstrating the IHP behavior. This critical grain size was found to be larger compared to other metallic nanocrystalline alloys. This IHP behaviour has been attributed to the structural complexity in quasicrystals and to thermally activated shearing events of atoms at the grain boundaries.

  15. CHP and CHPsim: A Language and Simulator for Fine-Grain Distributed Computation

    E-Print Network [OSTI]

    Martin, Alain

    1 CHP and CHPsim: A Language and Simulator for Fine-Grain Distributed Computation Alain J. Martin Abstract--This paper describes a complete and stable version of CHP and the simulator CHPsim. CHP partial versions of the language are already widely used, but CHP has never been presented as a complete

  16. Relative grain boundary area and energy distributions in nickel Jia Li, Shen J. Dillon 1

    E-Print Network [OSTI]

    Rohrer, Gregory S.

    Relative grain boundary area and energy distributions in nickel Jia Li, Shen J. Dillon 1 , Gregory boundary energies and areas are inversely correlated. Ó 2009 Acta Materialia Inc. Published by Elsevier Ltd and focused ion beam serial sectioning. These data have been used to determine the relative areas of different

  17. Lognormal Size Distribution Theory for Deposition of Polydisperse Aerosol Particles

    SciTech Connect (OSTI)

    Park, S.H.; Lee, K.W. [Kwangju Institute of Science and Technology (Korea, Republic of)

    2000-07-15T23:59:59.000Z

    The moments method of the lognormal size distribution theory was applied to the deposition equation of a radioactive aerosol within a liquid-metal fast breeder reactor for analysis of postulated accidents. The deposition coefficient of Crump and Seinfeld was utilized to represent the Brownian and turbulent diffusions and the gravitational sedimentation. The deposition equation was converted into a set of three ordinary differential equations. This approach takes the view point that the size distribution of an aerosol is represented by a time-dependent lognormal size distribution function during the deposition process. Numerical calculations have been performed, and the results were found to be in good agreement with the exact solution. The derived model for aerosol deposition is convenient to use in a numerical general dynamic equation solution routine based on the moments method, where nucleation, condensation, coagulation, and deposition need to be solved simultaneously.

  18. From flux to dust mass: Does the grain-temperature distribution matter for estimates of cold dust masses in supernova remnants?

    E-Print Network [OSTI]

    Mattsson, Lars; Andersen, Anja C; Matsuura, Mikako

    2015-01-01T23:59:59.000Z

    The amount of dust estimated from infrared to sub-millimetre (submm) observations strongly depends on assumptions of different grain sizes, compositions and optical properties. Here we use a simple model of thermal emission from cold silicate/carbon dust at a range of dust grain temperatures and fit the spectral energy distribution (SED) of the Crab Nebula as a test. This can lower the derived dust mass for the Crab by ~50% and 30-40% for astronomical silicates and amorphous carbon grains compared to recently published values (0.25M_sun -> 0.12M_sun and 0.12M_sun -> 0.072M_sun, respectively), but the implied dust mass can also increase by as much as almost a factor of six (0.25M_sun -> 1.14M_sun and 0.12M_sun -> 0.71M_sun) depending on assumptions regarding the sizes/temperatures of the coldest grains. The latter values are clearly unrealistic due to the expected metal budget, though. Furthermore, we show by a simple numerical experiment that if a cold-dust component does have a grain-temperature distribution...

  19. Effects of dust size distribution on dust negative ion acoustic solitary waves in a magnetized dusty plasma

    SciTech Connect (OSTI)

    Ma, Yi-Rong; Qi, Xin; Sun, Jian-An; Duan, Wen-Shan [Joint Laboratory of Atomic and Molecular Physics of NWNU and IMP CAS, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China and College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070 (China)] [Joint Laboratory of Atomic and Molecular Physics of NWNU and IMP CAS, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China and College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070 (China); Yang, Lei [Joint Laboratory of Atomic and Molecular Physics of NWNU and IMP CAS, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China and College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070 (China) [Joint Laboratory of Atomic and Molecular Physics of NWNU and IMP CAS, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China and College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070 (China); Department of Physics, Lanzhou University, Lanzhou 730000 (China)

    2013-08-15T23:59:59.000Z

    Dust negative ion acoustic solitary waves in a magnetized multi-ion dusty plasma containing hot isothermal electron, ions (light positive ions and heavy negative ions) and extremely massive charge fluctuating dust grains are investigated by employing the reductive perturbation method. How the dust size distribution affect the height and the thickness of the nonlinear solitary wave are given. It is noted that the characteristic of the solitary waves are different with the different dust size distribution. The magnitude of the external magnetic field also affects the solitary wave form.

  20. The relative grain boundary area and energy distributions in a ferritic steel determined from three-dimensional electron

    E-Print Network [OSTI]

    Rohrer, Gregory S.

    The relative grain boundary area and energy distributions in a ferritic steel determined from three The relative grain boundary area and energy distributions of a ferritic steel were characterized as a function planes with the (111) orientation had the minimum energy and the largest relative areas. The most

  1. Measurements and characterization of particle size distributions in coastal waters

    E-Print Network [OSTI]

    Stramski, Dariusz

    particle suspensions were measured using a laser diffractometer (LISST100X), an electrical impedance, the LISST provides an adequate proxy and has the capability for in situ measurements with high spatialMeasurements and characterization of particle size distributions in coastal waters R. A. Reynolds,1

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

    SciTech Connect (OSTI)

    Zurek, Anna K [Los Alamos National Laboratory; Muszka, K [AGH; Majta, J [AGH; Wielgus, M [AGH

    2009-01-01T23:59:59.000Z

    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.

  3. Loss Reduction of Power Distribution Network Using Optimum Size and Location of Distributed

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    Generation Adnan Anwar, Student Member, IEEE, and H. R. Pota, Member, IEEE Abstract--Distributed generation be reduced significantly. Index Terms--Distributed generation, Optimum size, Optimum location, Power loss directly to utility distribution system. The insulation level of the machines may not synchronize

  4. Slant visual range from drop-size distribution

    E-Print Network [OSTI]

    Arrance, Edwin Stanley

    1980-01-01T23:59:59.000Z

    YIci'Ai Ra', tq- DROP-SIZE DISTRIBU, ION A Thesi s EDWIN STANLEY ARPANCE Submitted to the Graduate College of Texas AIIM University in partial ful fi 1 lment of the requirement for the degree of M AS I . R 0 r S C I E I'I C E August I 9BO I...'laj or Subject: Mete orol oqy SLANT VISUAL RANGE FROM DROP-SIZE DISTRIBUTION A Thesis by EDWIN STANLEY ARRANCE Approved as to style and content by: Dr. Vance E. Moyer; (Chairman of Committee) Dr. Geor L. Huebner, Jr. (Member) Dr. Glen N. Williams...

  5. Particle size of reconstituted sorghum grain as related to its digestibility and to cattle performance

    E-Print Network [OSTI]

    Berry, Larry Don

    1970-01-01T23:59:59.000Z

    TREATMENTS OF SORGHUM GRAIN AFTER VARIOUS INCUBATION PERIODS . 27 RELATIVE IN VITRO GAS PRODUCTION EXPRESSED AS A PERCENT OF D-G CONTROL . CHEMICAL COMPOSITION OF FOUR FEED MIXTURES FED DURING DIGESTION EXPERIMENT 28 30 AVERAGE COEFFICIENTS... to 13 ion ouantities for use in this study. }hi grain was submitted to our trcatm nts as foils!!s: Dry-grourd {D-G) Ground-reconstituted (G-R) Ground-reconstituted-ground (G-R-G) Reconstiiutcd-ground (R-G) the recon"tiiutcd treatments consisted...

  6. The Size Distribution of Superbubbles in the Interstellar Medium

    E-Print Network [OSTI]

    M. S. Oey; C. J. Clarke

    1998-03-06T23:59:59.000Z

    We use the standard, adiabatic shell evolution to predict the size distribution N(R) for populations of SN-driven superbubbles in a uniform ISM. We derive N(R) for simple cases of superbubble creation rate and mechanical luminosity function. We then compare our predictions for N(R) with the largely complete HI hole catalogue for the SMC, with a view toward the global structure of the ISM in that galaxy. We also present a preliminary derivation for N(v), the distribution of shell expansion velocities.

  7. Aerosol size distribution evolution in large area fire plumes

    SciTech Connect (OSTI)

    Porch, W.M.; Penner, J.E.

    1986-09-01T23:59:59.000Z

    Large fires are significant seasonal contributors to western visibility reduction. We have found that the relative concentration of supermicron size particles (assumed to be a mixture of mechanically generated particles by high winds associated with large fires and low density chain aggregates from coagulation in the fire) and high turbulence in fire plumes can radically change the aerosol sizes in the fire plume. This is especially important for aerosols with high visibility reduction and long range transport potential. This calculation was done with a 10 level one dimensional model with parameterized vertical and horizontal diffusion, sedimentation and coagulation. The optical effects of the evolving concentration and size distributions were modeled using Mie scattering and absorption assumptions.

  8. Mineralogy and particle size of bed sediments 173 Chapter 7 -Quantitative Mineralogy and Particle-Size Distribution

    E-Print Network [OSTI]

    Mineralogy and particle size of bed sediments 173 Chapter 7 - Quantitative Mineralogy and Particle to assess particle-size distribution and mineralogical composition. Changes in particle- size distribution-ray diffraction, and their quantitative mineralogy was determined with a recently-developed computer program

  9. EFFECTS OF MINERALOGY, GRAIN SIZE, AND SOLUTION COMPOSITION ON LITHIUM SORPTION TO SATURATED ALLUVIUM SOUTH OF YUCCA MOUNTAIN, NEVADA

    SciTech Connect (OSTI)

    E. SULLIVAN; P. REIMUS; ET AL

    2001-05-01T23:59:59.000Z

    Lithium is used frequently as a surrogate for cationic radionuclides such as NpO{sub 2}{sup +} in field and laboratory settings. Current plans include the use of Li{sup +} as a reactive tracer in field tracer testing in the saturated alluvium south of Yucca Mountain, NV, site of a potential high-level nuclear waste. Characterization of the alluvial material for grain size, mineralogy, cation exchange capacity (CEC), and surface area yields data that is compared with lithium batch sorption as a first step in inferring radionuclide transport behavior. This research will be used to help assess performance of the potential repository.

  10. Study on grain boundary character and strain distribution of intergranular cracking in the CGHAZ of T23 steel

    SciTech Connect (OSTI)

    Jin, Y.J.; Lu, H., E-mail: shweld@sjtu.edu.cn; Yu, C.; Xu, J.J.

    2013-10-15T23:59:59.000Z

    Intergranular reheat cracking in the coarse-grained heat-affected zone of T23 steel was produced by strain to fracture tests on a Gleeble 3500 thermal–mechanical simulator. Then the grain boundary character, as well as the strain distribution after reheat crack propagation, was studied by electron backscatter diffraction technique. The results showed that incoherent ?3 boundaries were seldom found on the prior austenite grain boundaries. Therefore, only the type of random high-angle boundaries played a crucial role in the intergranular cracking. Microstructurally cavities and small cracks were preferentially initiated from high-angle grain boundaries. Low-angle grain boundaries and high-angle ones with misorientation angles less than 15° were more resistant to the cracking. More importantly, the fraction of high-angle grain boundaries increased with the plastic strain induced by both temperature gradient and stress in the coarse-grained heat-affected zone, which contributed to the crack initiation and propagation. Furthermore, the strain distributions in the vicinity of cavities and cracks revealed the accommodation processes of plastic deformation during stress relaxation. It also reflected the strength differences between grain interior and grain boundary at different heat-treated temperatures, which had a large influence on the cracking mechanism. - Highlights: • The coincidence site lattice boundaries play little role in the reheat cracking. • Cavity and crack occur at high-angle grain boundaries rather than low-angle ones. • The strain leads low-angle grain boundaries to transform to high-angle ones. • Strain distribution differs for cavity and crack zones at different temperatures.

  11. Population and Size Distribution of Small Jovian Trojan Asteroids

    E-Print Network [OSTI]

    D. C. Jewitt; C. A. Trujillo; J. X. Luu

    2000-04-10T23:59:59.000Z

    We present a study of Jovian Trojan objects detected serendipitously during the course of a sky survey conducted at the University of Hawaii 2.2-meter telescope. We used a 8192 x 8192 pixel charge-coupled device (CCD) mosaic to observe 20 deg^2 at locations spread over the L4 Lagrangian swarm and reached a limiting magnitude V = 22.5 mag (50% of maximum detection efficiency). Ninety-three Jovian Trojans were detected with radii 2 - 20 km (assumed albedo 0.04). Their differential magnitude distribution has a slope of 0.40 +/- 0.05 corresponding to a power law size distribution index 3.0 +/- 0.3 (1-sigma). The total number of L4 Trojans with radii > 1 km is of order 1.6 x 10^5 and their combined mass (dominated by the largest objects) is ~ 10^{-4} M_{Earth}. The bias-corrected mean inclination is 13.7 +/- 0.5 deg. We also discuss the size and spatial distribution of the L4 swarm.

  12. Method for measuring the size distribution of airborne rhinovirus

    SciTech Connect (OSTI)

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

    2002-01-01T23:59:59.000Z

    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.

  13. The Superbubble Size Distribution in the Interstellar Medium of Galaxies

    E-Print Network [OSTI]

    M. S. Oey; C. J. Clarke

    1997-03-17T23:59:59.000Z

    We use the standard, adiabatic shell evolution to predict the size distribution N(R) for populations of OB superbubbles in a uniform ISM. We derive N(R) for simple cases of superbubble creation rate and mechanical luminosity function (MLF). For R R_e it is dominated by growing objects. We also briefly investigate N(R) resulting from momentum-conserving shell evolution. We predict a peak in N(R) corresponding to individual SNRs. To estimate the MLF, we also examine evolutionary effects on the HII region luminosity function (HII LF), finding that for nebular luminosity fading as a power law in time, there is a minimum observed slope for the HII LFs. Comparison with the largely complete HI hole catalog for the SMC shows surprising agreement in the predicted and observed slope of N(R), suggesting that no other fundamental process is needed to explain the size distribution of shells in the SMC. Further comparison with largely incomplete HI data for M31, M33, and Holmberg II is also encouraging. We present expressions for the ISM porosity parameters, and estimate that they are substantially <1 for all of the galaxies except Holmberg II. Most of these galaxies therefore may not be strongly dominated by a hot interstellar component. However, porosity results for the Galaxy remain inconclusive.

  14. JOURNAL DE PHYSIQUE Colloque C I, fuppl&nent au no 2-3, Tome 32, Fkvrier-Mars 1971,page C 1 -383 THE RELATIONSHIP OF DOMAIN SPACING, GRAIN SIZE,

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    THE RELATIONSHIP OF DOMAIN SPACING, GRAIN SIZE, SHEET THICKNESS AND POWER LOSS K. J. OVERSHOTT, Wolfson Centre- , - - bowing was found to occur. The total power loss in the same grains has been measured at various flux) at a smaller grain length. - 1. Introduction. - The total power loss in grain- oriented siliconiron is greater

  15. 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...

  16. Fine scale modeling of wintertime aerosol mass, number, and size distributions in central California

    E-Print Network [OSTI]

    Jacobson, Mark

    Fine scale modeling of wintertime aerosol mass, number, and size distributions in central with the observed PM number and size distributions (with an NMB of -13.9%), indicating the importance of coagulation scale modeling of wintertime aerosol mass, number, and size distributions in central California, J

  17. Measurements of Gas Bubble Size Distributions in Flowing Liquid Mercury

    SciTech Connect (OSTI)

    Wendel, Mark W [ORNL; Riemer, Bernie [ORNL; Abdou, Ashraf A [ORNL

    2012-01-01T23:59:59.000Z

    ABSTRACT Pressure waves created in liquid mercury pulsed spallation targets have been shown to induce cavitation damage on the target container. One way to mitigate such damage would be to absorb the pressure pulse energy into a dispersed population of small bubbles, however, measuring such a population in mercury is difficult since it is opaque and the mercury is involved in a turbulent flow. Ultrasonic measurements have been attempted on these types of flows, but the flow noise can interfere with the measurement, and the results are unverifiable and often unrealistic. Recently, a flow loop was built and operated at Oak Ridge National Labarotory to assess the capability of various bubbler designs to deliver an adequate population of bubbles to mitigate cavitation damage. The invented diagnostic technique involves flowing the mercury with entrained gas bubbles in a steady state through a horizontal piping section with a glass-window observation port located on the top. The mercury flow is then suddenly stopped and the bubbles are allowed to settle on the glass due to buoyancy. Using a bright-field illumination and a high-speed camera, the arriving bubbles are detected and counted, and then the images can be processed to determine the bubble populations. After using this technique to collect data on each bubbler, bubble size distributions were built for the purpose of quantifying bubbler performance, allowing the selection of the best bubbler options. This paper presents the novel procedure, photographic technique, sample visual results and some example bubble size distributions. The best bubbler options were subsequently used in proton beam irradiation tests performed at the Los Alamos National Laboratory. The cavitation damage results from the irradiated test plates in contact with the mercury are available for correlation with the bubble populations. The most effective mitigating population can now be designed into prototypical geometries for implementation into an actual SNS target.

  18. EFFECTS OF SAMPLE SIZE ON CHARACTERIZATION OF WOOD-PARTICLE LENGTH DISTRIBUTION

    E-Print Network [OSTI]

    EFFECTS OF SAMPLE SIZE ON CHARACTERIZATION OF WOOD-PARTICLE LENGTH DISTRIBUTION Quang V. Cao of sample size on fitting length distribution of wood particles used for manufacturing wood-based composites moments and the ability of the sample distributions to characterize the population represented

  19. Fidelity of Analytic Drop Size Distributions in Drizzling Stratiform Clouds Based on Large-Eddy Simulations

    E-Print Network [OSTI]

    Kogan, Yefim L.; Kogan, Zena N.; Mechem, David B.

    2009-08-01T23:59:59.000Z

    Cloud microphysical parameterizations and retrievals rely heavily on knowledge of the shape of drop size distributions (DSDs). Many investigations assume that DSDs in the entire or partial drop size range may be approximated ...

  20. Size-dependent polarization distribution in ferroelectric nanostructures: Phase field simulations

    E-Print Network [OSTI]

    Chen, Long-Qing

    to memory and storage devices, sen- sors, and actuators. The properties of low-dimensional ferro- electricsSize-dependent polarization distribution in ferroelectric nanostructures: Phase field simulations distribution in ferroelectric nanostructures embedded in a nonferroelectric medium. The simulation results

  1. Size distribution and chemical composition of aerosol particles in the free troposphere over Japan: Aircraft measurements

    SciTech Connect (OSTI)

    Iwasaka, Y.; Mori, I.; Mastunga, K. [Nagoya Univ. (Japan)

    1996-12-31T23:59:59.000Z

    Aircraft measurements of number-, mass- and volume-size distributions of aerosols and concentration of sulfate, nitrate and others contained in particulate matter were made in the free troposphere over Japan in 1991-1994. Number-size distribution frequently shows a peak in the area of a diameter of D {ge} 1 {mu}m in the free troposphere during observational periods. A few peaks are identified in the volume-size distribution as estimated on the basis of number-size distribution having single mode in a coarse range. Mass-size distribution frequently indicate enhancement in the coarse size range. This feature of the distribution is more frequent in those measurements made at 4.42 km than those at 2.29 km. On the basis of a backward trajectory analysis of the air mass containing those particles, soil particles originating from the Asian continent affect the features found in the size distributions as well as and vertical change in those size distributions. Particulate sulfate concentration in the free troposphere suggested that chemical transformation of particles with D {ge} 1 {mu}m advanced during long range transport of the particle possibly through coagulation of sulfate particles on coarse size particles such as Asian dust particles, adsorption of gaseous sulfate. Those measurements provide useful data et to discuss global geochemical cycle and radiative forcing of particles originated from the Asian continent.

  2. Size distribution of recruited alveolar volumes in airway reopening

    E-Print Network [OSTI]

    Alencar, Adriano Mesquita

    during the reopening process can influence the distribution of recruited alveolar volumes and, hence, gas distribution of recruited alveolar volumes that become available for gas exchange during inflation from important quantity is the amount of alveolar volume available for gas exchange. This alveolar volume

  3. A fractal-based approach to lake size-distributions David A. Seekell,1

    E-Print Network [OSTI]

    Pace, Michael L.

    A fractal-based approach to lake size-distributions David A. Seekell,1 Michael L. Pace,1 Lars J in regional and global biogeochemical processes. Lakes are fractal but do not always conform to the power law size-distribution typically associated with fractal geographical features. Here, we evaluate

  4. Optimum Allocation and Sizing of DG Unit for Efficiency Enhancement of Distribution System

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    of appropriate size and location of DG reduces total power loss in a distribution system significantly and hence, Power loss reduction, Sensitivity analysis. I. INTRODUCTION Distributed Generation (DG) has gained its size and inappropriate allocation of generation may lead to higher power loss than when there is no DG

  5. Determination of pore-size distribution in low-dielectric thin films D. W. Gidleya)

    E-Print Network [OSTI]

    Gidley, David

    -size distribution on pore shape/dimensionality and sample temperature is predicted using a simple quantum mechanicalDetermination of pore-size distribution in low-dielectric thin films D. W. Gidleya) and W. E. Frieze Department of Physics, University of Michigan, Ann Arbor, Michigan 48109 T. L. Dull, J. Sun, and A

  6. A forward microphysical model to predict the size-distribution parameters of laboratory generated (mimic)

    E-Print Network [OSTI]

    Oxford, University of

    A forward microphysical model to predict the size- distribution parameters of laboratory generated Interactions ­ Condensational Growth and Coagulation, Submitted for Indian Aerosol Science and Technology Microphysical Model for the UTLS (FAMMUS) is applied to predict the size-distribution parameters of laboratory

  7. Lattice model for kinetics and grain-size distribution in crystallization Mario Castro*

    E-Print Network [OSTI]

    Sánchez, Angel "Anxo"

    and thin-film solar cells.2 With these and similar applications in mind, the capability to en- gineer deposition has been driven by the technological development of active matrix addressed flat-panel displays1

  8. 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

    2014-05-27T23:59:59.000Z

    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.

  9. Size distribution of particle systems analyzed with organic photodetectors

    E-Print Network [OSTI]

    Sentis, Matthias

    2015-01-01T23:59:59.000Z

    As part of a consortium between academic and industry, this PhD work investigates the interest and capabilities of organic photo-sensors (OPS) for the optical characterization of suspensions and two-phase flows. The principle of new optical particle sizing instruments is proposed to characterize particle systems confined in a cylinder glass (standard configuration for Process Analytical Technologies). To evaluate and optimize the performance of these systems, a Monte-Carlo model has been specifically developed. This model accounts for the numerous parameters of the system: laser beam profile, mirrors, lenses, sample cell, particle medium properties (concentration, mean & standard deviation, refractive indices), OPS shape and positions, etc. Light scattering by particles is treated either by using Lorenz-Mie theory, Debye, or a hybrid model (that takes into account the geometrical and physical contributions). For diluted media (single scattering), particle size analysis is based on the inversion of scatter...

  10. SUPPORTING INFORMATION2 Simplifying aerosol size distributions modes4

    E-Print Network [OSTI]

    Meskhidze, Nicholas

    la Barceloneta 37-49, 08003 Barcelona, Spain27 28 29 30 #12;2 1 Table S1: Hourly k-means cluster size.35 0.40 0.45 T1 T2 T3 UB1 RB1 RB2 NU MIX NIT CO(mgm-3) CO RS UB TC RB (j) Figure S2: Comparison: Comparison for each significant cluster at each site (RS, UB, TC, RB) of: a) particle number2 concentration

  11. Distribution Network Design: Selection and Sizing of Congested Connections

    E-Print Network [OSTI]

    Nagi, Rakesh

    promotions (i.e., seasonal) and regular demand. In response to this, at the strategic or aggregate level demand. Several multinational companies use distribution center networks in this manner. For example. For most fast moving consumer goods, demand patterns are quite erratic, being a function of both sales

  12. LOAD PROFILING IN DISTRIBUTED REALTIME SYSTEMS \\Lambda ``One Size Doesn't Fit All''

    E-Print Network [OSTI]

    LOAD PROFILING IN DISTRIBUTED REAL­TIME SYSTEMS \\Lambda ``One Size Doesn't Fit All'' Azer Bestavros a new load­profiling strategy that allows the nodes of a distributed system to be unequally loaded. Using load profiling, the system attempts to distribute the load amongst its nodes so as to maximize

  13. The dune size distribution and scaling relations of barchan dune fields

    E-Print Network [OSTI]

    Orencio Durán; Veit Schwämmle; Pedro G. Lind; Hans J. Herrmann

    2008-10-27T23:59:59.000Z

    Barchan dunes emerge as a collective phenomena involving the generation of thousands of them in so called barchan dune fields. By measuring the size and position of dunes in Moroccan barchan dune fields, we find that these dunes tend to distribute uniformly in space and follow an unique size distribution function. We introduce an analyticalmean-field approach to show that this empirical size distribution emerges from the interplay of dune collisions and sand flux balance, the two simplest mechanisms for size selection. The analytical model also predicts a scaling relation between the fundamental macroscopic properties characterizing a dune field, namely the inter-dune spacing and the first and second moments of the dune size distribution.

  14. 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

    2013-07-30T23:59:59.000Z

    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.

  15. Temperature fluctuations of interstellar dust grains

    E-Print Network [OSTI]

    Kobi Horn; Hagai B. Perets; Ofer Biham

    2007-09-20T23:59:59.000Z

    The temperatures of interstellar dust grains are analyzed using stochastic simulations, taking into account the grain composition and size and the discreteness of the photon flux. [...] The distribution of grain temperatures is calculated for a broad range of grain sizes and for different intensities of the interstellar radiation field, relevant to diffuse clouds and to PDRs. The dependence of the average grain temperature on its size is shown for different irradiation intensities. It is found that the average temperatures of grains with radii smaller than about 0.02 $\\mu$m are reduced due to the fluctuations. The average temperatures of grains of radii larger than about 0.35 $\\mu$m are also slightly reduced due to their more efficient emission of infrared radiation, particularly when exposed to high irradiation intensities. The average temperatures of silicate and carbonaceous grains are found to depend on the radiation field intensity X_MMP according to ~X_MMP^gamma, where the exponent gamma depends on the grain size and composition. This fitting formula is expected to be useful in simulations of interstellar processes, and can replace commonly used approximations which do not account for the grain temperature fluctuations and for the detailed properties of interstellar dust particles. The implications of the results on molecular hydrogen formation are also discussed. It is concluded that grain-temperature fluctuations tend to reduce the formation rate of molecular hydrogen, and cannot account for the observations of H_2 in photon dominated regions, even in the presence of chemisorption sites.

  16. GRAIN SORTING IN COMETARY DUST FROM THE OUTER SOLAR NEBULA

    SciTech Connect (OSTI)

    Wozniakiewicz, P. J.; Bradley, J. P.; Ishii, H. A. [Institute of Geophysics and Planetary Physics, Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Brownlee, D. E. [Department of Astronomy, University of Washington, Seattle, WA (United States); Kearsley, A. T. [Department of Mineralogy, Natural History Museum, London SW7 5BD (United Kingdom); Burchell, M. J.; Price, M. C., E-mail: P.Wozniakiewicz@kent.ac.uk [School of Physical Sciences, University of Kent, Canterbury, Kent CT2 7NH (United Kingdom)

    2012-12-01T23:59:59.000Z

    Most young stars are surrounded by a disk of gas and dust. Close to the hot stars, amorphous dust grains from the parent molecular cloud are reprocessed into crystals that are then distributed throughout the accretion disk. In some disks, there is a reduction in crystalline grain size with heliocentric distance from the star. We investigated crystalline grain size distributions in chondritic porous (CP) interplanetary dust particles (IDPs) believed to be from small, icy bodies that accreted in outer regions of the solar nebula. The grains are Mg-rich silicates and Fe-rich sulfides, the two most abundant minerals in CP IDPs. We find that they are predominantly <0.25 {mu}m in radius with a mean grain size that varies from one CP IDP to another. We report a size-density relationship between the silicates and sulfides. A similar size-density relationship between much larger silicate and sulfide grains in meteorites from the asteroid belt is ascribed to aerodynamic sorting. Since the silicate and sulfide grains in CP IDPs are theoretically too small for aerodynamic sorting, their size-density relationship may be due to another process capable of sorting small grains.

  17. Time Evolution of the Mutual Fund Size Distribution Yonathan Schwarzkopf1,2

    E-Print Network [OSTI]

    empirically and theoreti- cally. The size of large mutual funds has a heavy tailed distribution that has been into a power law only over long time scales, suggesting that log-normality comes about because the industry

  18. Particle size distribution and mineralogy of Brazilian Ferralsols: Significance for the structure and hydraulic properties

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Particle size distribution and mineralogy of Brazilian Ferralsols: Significance for the structure of the mineralogy on the structure and hydraulic properties of Ferralsols. The Ferralsols (F) studied were selected according to the mineralogy of the

  19. Lipid-Protein Interactions Alter Line Tensions and Domain Size Distributions in Lung Surfactant Monolayers

    E-Print Network [OSTI]

    Dhar, Prajnaparamita

    The size distribution of domains in phase-separated lung surfactant monolayers influences monolayer viscoelasticity and compressibility which, in turn, influence monolayer collapse and set the compression at which the ...

  20. 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

    2013-08-13T23:59:59.000Z

    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.

  1. Effect of densification mechanism on the S2 grain boundary plane distribution in WCCo composites

    E-Print Network [OSTI]

    Rohrer, Gregory S.

    (sinter- HIP) and spark plasma sintering (SPS). It was found that the S2 twist boundary is the most common point of Co, was maintained for 30 min. Sample 2 (similarly hereinafter) was prepared via spark plasma Keywords: Grain boundary Cemented carbide Sintering Electron microscopy Five parameter analysis a b s t r

  2. The influence of particle-size distribution and moisture levels on the formation of soil hardpans

    E-Print Network [OSTI]

    Bauer, Herman John

    1963-01-01T23:59:59.000Z

    THE INFLUENCE OF PARTICLE-SIZE DISTRIBUTION AND MOISTURE LEVELS ON THE FORMATION OF SOIL HARDPANS A Thesis By HERMAN J. BAUER Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE January, 1963 Major Subject: Soil Physics THE INFLUENCE OF PARTICLE-SIZE DISTRIBUTION AND MOISTURE LEVELS ON THE FORMATION OF SOIL HARDPANS A Thesis By HERMAN J. BAUER Approved as to style and content...

  3. The influence of particle-size distribution and moisture levels on the formation of soil hardpans 

    E-Print Network [OSTI]

    Bauer, Herman John

    1963-01-01T23:59:59.000Z

    THE INFLUENCE OF PARTICLE-SIZE DISTRIBUTION AND MOISTURE LEVELS ON THE FORMATION OF SOIL HARDPANS A Thesis By HERMAN J. BAUER Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE January, 1963 Major Subject: Soil Physics THE INFLUENCE OF PARTICLE-SIZE DISTRIBUTION AND MOISTURE LEVELS ON THE FORMATION OF SOIL HARDPANS A Thesis By HERMAN J. BAUER Approved as to style and content...

  4. Size distributions of ionic aerosols measured at Waliguan Observatory: Implication for nitrate gas-to-particle

    E-Print Network [OSTI]

    Jacobson, Mark

    Size distributions of ionic aerosols measured at Waliguan Observatory: Implication for nitrate gas Plateau. Size-resolved ionic aerosols (NH4 + , Na+ , K+ , Ca2+ , Mg2+ , SO4 2À , ClÀ , NO3 À CO3 2À , formate, acetate and oxalate), organic aerosols, black carbon and gaseous HNO3 and SO2 were measured

  5. Sieving duration and sieve loading impacts on dry soil fragment size distributions

    E-Print Network [OSTI]

    Perfect, Ed

    ; accepted 18 June 2006 Abstract Measurement of the soil fragment size distribution has been found.g. wind and water erosion, infiltration and aeration) crop establishment and productivity (Skidmore et al is inversely related to the amount of applied energy, and does not necessarily reflect the size of aggregates

  6. LOAD PROFILING IN DISTRIBUTED REAL-TIME SYSTEMS \\One Size Doesn't Fit All"

    E-Print Network [OSTI]

    LOAD PROFILING IN DISTRIBUTED REAL-TIME SYSTEMS \\One Size Doesn't Fit All" Azer Bestavros (best@cs.bu.edu) Boston University Computer Science Department 111 Cummington street Boston, MA 02215 Abstract Load balancing is often used to ensure that nodes in a distributed systems are equally loaded. In this paper, we

  7. Spatial distribution and size evolution of particles in Asian outflow: Significance of primary and secondary aerosols during ACE-Asia

    E-Print Network [OSTI]

    volatility suggested increasing neutralization of the aerosol during growth. Size distribution measurements; KEYWORDS: ACE-Asia, TRACE-P, aerosol size distribution, nucleation, primary and secondary aerosols, condensation and coagulation Citation: Mc Naughton, C. S., et al. (2004), Spatial distribution and size

  8. 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.

    2011-11-01T23:59:59.000Z

    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.

  9. TIME INTEGRATED MEASUREMENTS OF THE ACTIVITY-WEIGHTED SIZE DISTRIBUTION OF RADON PROGENY by

    E-Print Network [OSTI]

    William C. Tetley P. E; Daniel R. Westcott; Bruce A. Cununings

    The dose to the lung is dependent on the size distribution as well as the concentration of radon progeny. The principal indicator of particle size is the diffusion coefficient. The diffusion coefficient of radon progeny is the most important parameter in determining whether the particle will deposit its alpha energy in the tracheobronchial region of the respiratory tract. Due to the importance of the size distribution of progeny when characterizing health effects, a detector was developed that exploits the difference in diffusion coefficients to provide integrated measurements of the activity-weighted size distribution. Several radon chamber tests were performed in which the diffusion coefficient and unattached fraction of radon progeny were varied by the use of trace gasses and aerosol particles. The technical feasibility of this new detector design was demonstrated in all cases.

  10. Development of laboratory and process sensors to monitor particle size distribution of industrial slurries

    SciTech Connect (OSTI)

    Pendse, H.P.

    1992-10-01T23:59:59.000Z

    In this paper we present a novel measurement technique for monitoring particle size distributions of industrial colloidal slurries based on ultrasonic spectroscopy and mathematical deconvolution. An on-line sensor prototype has been developed and tested extensively in laboratory and production settings using mineral pigment slurries. Evaluation to date shows that the sensor is capable of providing particle size distributions, without any assumptions regarding their functional form, over diameters ranging from 0.1 to 100 micrometers in slurries with particle concentrations of 10 to 50 volume percents. The newly developed on-line sensor allows one to obtain particle size distributions of commonly encountered inorganic pigment slurries under industrial processing conditions without dilution.

  11. Finite Size Effects on the Real-Space Pair Distribution Function of Nanoparticles

    SciTech Connect (OSTI)

    Gilbert, Benjamin

    2008-10-01T23:59:59.000Z

    The pair distribution function (PDF) method is a powerful approach for the analysis of the structure of nanoparticles. An important approximation used in nanoparticle PDF simulations is the incorporation of a form factor describing nanoparticle size and shape. The precise effect of the form factor on the PDF is determined by both particle shape and structure if these characteristics are both anisotropic and correlated. The correct incorporation of finite size effects is important for distinguishing and quantifying the structural consequences of small particle size in nanomaterials.

  12. 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. [Département de Physique et Regroupement Québécois sur les Matériaux de Pointe (RQMP), Université de Montréal, C.P. 6128, Succursale Centre-Ville, Montréal, Québec H3C 3J7 (Canada); Anoop, K. K.; Ausanio, G.; Bruzzese, R.; Amoruso, S., E-mail: amoruso@na.infn.it [Dipartimento di Fisica, Università degli Studi di Napoli Federico II and CNR-SPIN, Complesso Universitario di Monte S. Angelo, Via Cintia, I-80126 Napoli (Italy)

    2014-06-28T23:59:59.000Z

    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.

  13. Distribution and direct radiative forcing of carbonaceous and sulfate aerosols in an interactive size-resolving

    E-Print Network [OSTI]

    Distribution and direct radiative forcing of carbonaceous and sulfate aerosols in an interactive size-resolving aerosol­climate model Dongchul Kim,1 Chien Wang,1 Annica M. L. Ekman,2 Mary C. Barth,3 August 2008. [1] A multimode, two-moment aerosol model has been incorporated in the NCAR CAM3 to develop

  14. Measurements of Mexico City nanoparticle size distributions: Observations of new particle formation and growth

    E-Print Network [OSTI]

    Jimenez, Jose-Luis

    Measurements of Mexico City nanoparticle size distributions: Observations of new particle formation diameter range were performed in the Mexico City metropolitan area. These measurements were made during the period 10­20 April 2003 at a ground-based, mountain pass site in the southeast corner of the Mexico City

  15. Computational and experimental study of the cluster size distribution in MAPLE

    E-Print Network [OSTI]

    Zhigilei, Leonid V.

    for 300 s (melting temperature of toluene is $178 K). Toluene is selected as the matrix solvent due films deposited in matrix-assisted pulsed laser evaporation (MAPLE). Analysis of high-resolution SEM-assisted pulsed laser evaporation; Cluster size distribution; Molecular dynamics; Laser ablation Matrix

  16. Investigation of the relationship between chemical composition and size distribution of airborne particles by partial least

    E-Print Network [OSTI]

    Stanier, Charlie

    combustion sources, secondary aerosol, and coal-fired power plants. The size distribution, particle identified: secondary nitrate 1 and 2, remote traffic, secondary sulfate, lead, diesel traffic, coal-fired power plant, steel mill, nucleation, local traffic, and coke plant. Citation: Zhou, L., P. K. Hopke, C

  17. ON CENTRIFUGAL SETTLING OF POLYDISPERSE SUSPENSIONS WITH A CONTINUOUS PARTICLE SIZE DISTRIBUTION

    E-Print Network [OSTI]

    Bürger, Raimund

    -density particles [3]. The settling of an N-disperse suspension, including the formation of sediment, can@ucn.cl ABSTRACT Gravity or centrifugal sedimentation of polydisperse suspensions with a continuous particle size distribution (PSD) can be modelled by a kinetic equation, which represents the limit case of a system

  18. A particle size distribution was determined from the image analysis. With more expensive equipment,

    E-Print Network [OSTI]

    Demirel, Melik C.

    contributes to fines generation during mining operations, the best practice is to replace drill bits Distribution Analysis Overview Kennametal, Incorporated is a major manufacturer of drill bits for mining ideally sized, half-inch pieces of coal. Because dull drill bits on mining machines significantly

  19. Three-dimensional assemblies built up by quantum dots in size-quantization regime: Band gap shifts due to size-distribution of cadmium selenide nanoparticles

    SciTech Connect (OSTI)

    Pejova, Biljana, E-mail: biljana@pmf.ukim.mk

    2013-11-15T23:59:59.000Z

    In the present study, it is predicted that the band gap energy of a three-dimensional quantum dot assembly exhibits a red shift when the dispersion of the crystal size distribution is enlarged, even at a fixed average value thereof. The effect is manifested when the size quantization regime in individual quantum dots constituting the assembly has been entered. Under the same conditions, the sub-band gap absorption tails are characterized with large Urbach energies, which could be one or two orders of magnitude larger than the value characteristic for the non-quantized case. - Graphical abstract: Band gap shifts due to size-distribution of nanoparticles in 3D assemblies built up by quantum dots in size-quantization regime. Display Omitted - Highlights: • Optical absorption of 3D QD assemblies in size-quantization regime is modeled. • Band gap energy of the QD solid depends on the size-distribution of the nanoparticles. • QD solid samples with same ?R? exhibit band gap shift depending on size distribution. • QD size distribution leads to large Urbach energies.

  20. Probe measurements and numerical model predictions of evolving size distributions in premixed flames

    SciTech Connect (OSTI)

    De Filippo, A.; Sgro, L.A.; Lanzuolo, G.; D'Alessio, A. [Dipartimento di Ingegneria Chimica, Universita degli Studi di Napoli Federico II, Piazzale Tecchio 80, 80125 Napoli (Italy)

    2009-09-15T23:59:59.000Z

    Particle size distributions (PSDs), measured with a dilution probe and a Differential Mobility Analyzer (DMA), and numerical predictions of these PSDs, based on a model that includes only coagulation or alternatively inception and coagulation, are compared to investigate particle growth processes and possible sampling artifacts in the post-flame region of a C/O = 0.65 premixed laminar ethylene-air flame. Inputs to the numerical model are the PSD measured early in the flame (the initial condition for the aerosol population) and the temperature profile measured along the flame's axial centerline. The measured PSDs are initially unimodal, with a modal mobility diameter of 2.2 nm, and become bimodal later in the post-flame region. The smaller mode is best predicted with a size-dependent coagulation model, which allows some fraction of the smallest particles to escape collisions without resulting in coalescence or coagulation through the size-dependent coagulation efficiency ({gamma}{sub SD}). Instead, when {gamma} = 1 and the coagulation rate is equal to the collision rate for all particles regardless of their size, the coagulation model significantly under predicts the number concentration of both modes and over predicts the size of the largest particles in the distribution compared to the measured size distributions at various heights above the burner. The coagulation ({gamma}{sub SD}) model alone is unable to reproduce well the larger particle mode (mode II). Combining persistent nucleation with size-dependent coagulation brings the predicted PSDs to within experimental error of the measurements, which seems to suggest that surface growth processes are relatively insignificant in these flames. Shifting measured PSDs a few mm closer to the burner surface, generally adopted to correct for probe perturbations, does not produce a better matching between the experimental and the numerical results. (author)

  1. 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.

    2001-01-01T23:59:59.000Z

    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 condensation of vaporized material and subsequent rapid formation of aggregates. Particles of larger size, resulting from ejection of melted material or fragments from the cutting zone, were also observed. This study presents data regarding the metal cutting rate, particle size distribution, and their generation rate, while using different cutting tools and metals. The study shows that respirable particles constitute only a small fraction of the released kerf.

  2. Ultrahigh throughput plasma processing of free standing silicon nanocrystals with lognormal size distribution

    SciTech Connect (OSTI)

    Dogan, Ilker; Kramer, Nicolaas J.; Westermann, Rene H. J.; Verheijen, Marcel A. [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Dohnalova, Katerina; Gregorkiewicz, Tom [Van der Waals-Zeeman Institute, University of Amsterdam, Science Park 904, 1098 XH Amsterdam (Netherlands); Smets, Arno H. M. [Photovoltaic Materials and Devices Laboratory, Delft University of Technology, P.O. Box 5031, 2600 GA Delft (Netherlands); Sanden, Mauritius C. M. van de [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Dutch Institute for Fundamental Energy Research (DIFFER), P.O. Box 1207, 3430 BE Nieuwegein (Netherlands)

    2013-04-07T23:59:59.000Z

    We demonstrate a method for synthesizing free standing silicon nanocrystals in an argon/silane gas mixture by using a remote expanding thermal plasma. Transmission electron microscopy and Raman spectroscopy measurements reveal that the distribution has a bimodal shape consisting of two distinct groups of small and large silicon nanocrystals with sizes in the range 2-10 nm and 50-120 nm, respectively. We also observe that both size distributions are lognormal which is linked with the growth time and transport of nanocrystals in the plasma. Average size control is achieved by tuning the silane flow injected into the vessel. Analyses on morphological features show that nanocrystals are monocrystalline and spherically shaped. These results imply that formation of silicon nanocrystals is based on nucleation, i.e., these large nanocrystals are not the result of coalescence of small nanocrystals. Photoluminescence measurements show that silicon nanocrystals exhibit a broad emission in the visible region peaked at 725 nm. Nanocrystals are produced with ultrahigh throughput of about 100 mg/min and have state of the art properties, such as controlled size distribution, easy handling, and room temperature visible photoluminescence.

  3. Scale-free Universal Spectrum for Atmospheric Aerosol Size Distribution for Davos, Mauna Loa and Izana

    E-Print Network [OSTI]

    A. M. Selvam

    2014-08-14T23:59:59.000Z

    Atmospheric flows exhibit fractal fluctuations and inverse power law form for power spectra indicating an eddy continuum structure for the selfsimilar fluctuations. A general systems theory for fractal fluctuations developed by the author is based on the simple visualisation that large eddies form by space-time integration of enclosed turbulent eddies, a concept analogous to Kinetic Theory of Gases in Classical Statistical Physics. The ordered growth of atmospheric eddy continuum is in dynamical equilibrium and is associated with Maximum Entropy Production. The model predicts universal (scale-free) inverse power law form for fractal fluctuations expressed in terms of the golden mean. Atmospheric particulates are held in suspension in the fractal fluctuations of vertical wind velocity. The mass or radius (size) distribution for homogeneous suspended atmospheric particulates is expressed as a universal scale-independent function of the golden mean, the total number concentration and the mean volume radius. Model predicted spectrum is in agreement (within two standard deviations on either side of the mean) with total averaged radius size spectra for the AERONET (aerosol inversions) stations Davos and Mauna Loa for the year 2010 and Izana for the year 2009 daily averages. The general systems theory model for aerosol size distribution is scale free and is derived directly from atmospheric eddy dynamical concepts. At present empirical models such as the log normal distribution with arbitrary constants for the size distribution of atmospheric suspended particulates are used for quantitative estimation of earth-atmosphere radiation budget related to climate warming/cooling trends. The universal aerosol size spectrum will have applications in computations of radiation balance of earth-atmosphere system in climate models.

  4. The inertial and electrical effects on aerosol sampling, charging, and size distribution

    SciTech Connect (OSTI)

    Wang, Chuenchung.

    1991-01-01T23:59:59.000Z

    An experimental study was conducted to investigate the effect of particle inertia on deposition behavior near the filter cassette sampler. Field sampling cassettes were tested in a subsonic wind tunnel for 0.2, 0.5 and 0.68 m/s wind speeds to simulate indoor air environment. Fluorescein aerosols of 2 and 5 {mu}m were generated from Berglund-Liu vibrating orifice generator as test material. Sampling tests were conducted in a subsonic wind tunnel with variables of particle size, wind speed, suction velocity and orientation of sampler examined to evaluate the combined effects. Sampling efficiencies were also examined. Electrostatic force is usually used as an effective method for removing, classifying and separating aerosols according to the electrical mobilities of the particulates. On the other hand, the aerosol charging theories possess differences in the ultrafine size range and need experimental verification. The present TSI's electrostatic aerosol analyzer has particle loss problem and cannot be used as a reliable tool in achieving efficient charging. A new unipolar charger with associated electronic circuits was designed, constructed and tested. The performance of the charger is tested in terms of particle loss, uncharged particles, and the collection efficiency of the precipitator. The results were compared with other investigator's data. The log-Beta distribution function is considered to be more versatile in representing size distribution. This study discussed the method in determining the size parameters under different conditions. Also the mutability of size distribution was evaluated when particles undergo coagulation or classification processes. Comparison of evolution between log-Beta and lognormal distributions were made.

  5. Particle Size Distribution Data From Existing Boreholes at the Immobilized Low-Activity Waste Site

    SciTech Connect (OSTI)

    Valenta, Michelle M.; Martin, Maria B.; Moreno, Jorge R.; Ferri, Rosalie M.; Horton, Duane G.; Reidel, Stephen P.

    2000-09-25T23:59:59.000Z

    This report provides particle size distribution data for samples near the Immobilized Low-Activity Waste (ILAW) Site that were archived in the Hanford Geotechnical Sample Library. Seventy-nine sediment samples were analyzed from four boreholes. Samples were collected from every ten feet in the boreholes. Eightly percent of the samples were classified as slightly gravelly sand. Fifteen percent were classified as gravelly sand, gravelly silty sand, or sandy gravels. These data indicate that the particle size of the sediment is consistent across the ILAW site and is dominated by sand in the upper part of the Hanford formation with more gravel rich units in the lower part.

  6. 6/10/12 The use of acoustic inversion to estimate the bubble size distribution in pipelines 1/4energy-daily.com/.../The_use_of_acoustic_inversion_to_estimate_the_bubble_size_distribution_in_...

    E-Print Network [OSTI]

    Sóbester, András

    6/10/12 The use of acoustic inversion to estimate the bubble size distribution in pipelines 1 address ... yes . . . The use of acoustic inversion to estimate the bubble size distribution in pipelines devised a new method to more accurately measure gas bubbles in pipelines. The ability to measure gas

  7. The effect of fuel and engine design on diesel exhaust particle size distributions

    SciTech Connect (OSTI)

    Baumgard, K.J.; Johnson, J.H. [Michigan Technological Univ., Houghton, MI (United States)

    1996-09-01T23:59:59.000Z

    The objective of this research was to obtain diesel particle size distributions from a 1988 and a 1991 diesel engine using three different fuels and two exhaust control technologies (a ceramic particle trap and an oxidation catalytic converter). The particle size distributions from both engines were used to develop models to estimate the composition of the individual size particles. Nucleation theory of the H{sub 2}O and H{sub 2}SO{sub 4} vapor is used to predict when nuclei-mode particles will form in the dilution tunnel. Combining the theory with the experimental data, the conditions necessary in the dilution tunnel for particle formation are predicted. The paper also contains a discussion on the differences between the 1988 and 1991 engine`s particle size distributions. The results indicated that nuclei mode particles (0.0075--0.046 {micro}m) are formed in the dilution tunnel and consist of more than 80% H{sub 2}O-H{sub 2}SO{sub 4} particles when using the 1988 engine and 0.29 wt% sulfur fuel. Nucleation theory indicated that H{sub 2}O-H{sub 2}SO{sub 4} particles may form during dilution at 0.03 wt% fuel sulfur levels and above. The 1991 engine was designed for lower particulate emissions than the 1988 engine and the 1991 engine`s accumulation mode particles (0.046-1.0 {micro}m) were reduced more than 80% by volume compared to the 1988 engine using the same low sulfur fuel. The particle size composition model indicated that using low sulfur fuel and the 1991 engine, the nuclei mode contained more than 45% of the total solid particles and over 85% of the soluble organic fraction.

  8. 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., E-mail: mmohamad@kfu.edu.sa [Department of Physics, College of Science, King Faisal University, Al-Ahsaa 31982 (Saudi Arabia); Department of Physics, Faculty of Science, Assiut University in the New Valley, El-Kharga 72511 (Egypt); Yamada, Koji [Department of Applied Molecular Chemistry, College of Industrial Technology, Nihon University, Narashino, Chiba 275-8575 (Japan)

    2014-04-21T23:59:59.000Z

    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 2–3??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.

  9. Finite-size analysis of a continuous-variable quantum key distribution

    SciTech Connect (OSTI)

    Leverrier, Anthony [Institut Telecom / Telecom ParisTech, CNRS LTCI, 46 rue Barrault, 75634 Paris Cedex 13, France and ICFO-Institut de Ciences Fotoniques, E-08860 Castelldefels (Barcelona) (Spain); Grosshans, Frederic [Laboratoire de Photonique Quantique et Moleculaire, ENS de Cachan, UMR CNRS 8735, F-94235 Cachan Cedex (France); Grangier, Philippe [Laboratoire Charles Fabry, Institut d'Optique, CNRS, Universite Paris-Sud, Campus Polytechnique, RD 128, F-91127 Palaiseau Cedex (France)

    2010-06-15T23:59:59.000Z

    The goal of this paper is to extend the framework of finite-size analysis recently developed for quantum key distribution to continuous-variable protocols. We do not solve this problem completely here, and we mainly consider the finite-size effects on the parameter estimation procedure. Despite the fact that some questions are left open, we are able to give an estimation of the secret key rate for protocols which do not contain a postselection procedure. As expected, these results are significantly more pessimistic than those obtained in the asymptotic regime. However, we show that recent continuous-variable protocols are able to provide fully secure secret keys in the finite-size scenario, over distances larger than 50 km.

  10. OXYGEN DEPLETION IN THE INTERSTELLAR MEDIUM: IMPLICATIONS FOR GRAIN MODELS AND THE DISTRIBUTION OF ELEMENTAL OXYGEN

    SciTech Connect (OSTI)

    Whittet, D. C. B. [New York Center for Astrobiology, and Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, 110 Eighth Street, Troy, NY 12180 (United States)

    2010-02-20T23:59:59.000Z

    This paper assesses the implications of a recent discovery that atomic oxygen is being depleted from diffuse interstellar gas at a rate that cannot be accounted for by its presence in silicate and metallic oxide particles. To place this discovery in context, the uptake of elemental O into dust is considered over a wide range of environments, from the tenuous intercloud gas and diffuse clouds sampled by the depletion observations to dense clouds where ice mantles and gaseous CO become important reservoirs of O. The distribution of O in these contrasting regions is quantified in terms of a common parameter, the mean number density of hydrogen (n{sub H}). At the interface between diffuse and dense phases (just before the onset of ice-mantle growth) as much as {approx}160 ppm of the O abundance is unaccounted for. If this reservoir of depleted oxygen persists to higher densities it has implications for the oxygen budget in molecular clouds, where a shortfall of the same order is observed. Of various potential carriers, the most plausible appears to be a form of O-bearing carbonaceous matter similar to the organics found in cometary particles returned by the Stardust mission. The 'organic refractory' model for interstellar dust is re-examined in the light of these findings, and it is concluded that further observations and laboratory work are needed to determine whether this class of material is present in quantities sufficient to account for a significant fraction of the unidentified depleted oxygen.

  11. Soil water and particle size distribution influence laboratory-generated PM10 Nicholaus M. Madden a,*, Randal J. Southard a

    E-Print Network [OSTI]

    Ahmad, Sajjad

    Soil water and particle size distribution influence laboratory-generated PM10 Nicholaus M. Madden a Soil particle size distribution Soil water content a b s t r a c t Management of soils to reduce earlier work of predicting tillage-generated dust emissions based on soil properties. We focus

  12. Prediction of the Size Distributions of Methanol-Ethanol Clusters Detected in VUV Laser/Time-of-Flight Mass Spectrometry

    E-Print Network [OSTI]

    Goddard III, William A.

    Prediction of the Size Distributions of Methanol-Ethanol Clusters Detected in VUV Laser distributions and geometries of vapor clusters equilibrated with methanol-ethanol (Me-Et) liquid mixtures were distributions of vapor clusters equilibrated with liquids, ranging from neat alcohols1,2 to methanol-ethanol (Me

  13. Comparison of airborne and surface particulate size distributions in specific Hanford Nuclear Facilities

    SciTech Connect (OSTI)

    Ottley, D.B.

    1995-05-01T23:59:59.000Z

    Settled dust from nuclear operations may be contaminated with radionuclides and become resuspended and subsequently breathed. This is the predominate radionuclide inhalation hazard scenario in nuclear facilities that have been deactivated and no longer have liquid in their process systems that may become directly airborne in accident situations. Comparisons were made between indoor ambient airborne particulate size distribution and that of resuspended dust that could become contaminated and subsequently airborne during decommissioning operations at selected nuclear facilities on the Hanford Site. Results indicate that only 5% of the particles, by count, above the breathing zone are greater than ten (10) {mu}m in size and that the particulates that could be resuspended into the breathing zone had a mean aerodynamic equivalent diameter of four (4) {mu}m or less.

  14. Vertical transport and dynamic size distribution of New Bedford Harbor sediments

    E-Print Network [OSTI]

    Sanders, Stephanie Carol

    1990-01-01T23:59:59.000Z

    02? 1000 0 E 0 08 0 0 06- o IO OO. . " 6 Krone 1000 m 530 O. C 2- 120 0~~~1 oOI- Allersma 0 61- 0 I- 06- 06 04 06[ 02 0 0 2 4 8 8 10 12 14 16 18 20 22 24 26 28 Salinity (ppt) Fig. 8. - Variation of Particle Settling Velocity...VERTICAL ~SPORT AND DYNAMIC SIZE DISTRIBUTION OF NEW BEDFORD HARBOR SEDIMENTS A Thesis STEPHANIE CAROL SANDERS Submitted to the Office of Graduate Studies of Texas A&:M University in partia! fulfillment of the requuements for the degree...

  15. The effect of dust size distribution on quantum dust acoustic wave

    SciTech Connect (OSTI)

    El-Labany, S. K.; El-Taibany, W. F.; Behery, E. E. [Department of Physics, Faculty of Science, Mansoura University, Damietta Branch, Damietta El-Gedida, P.O. 34517 (Egypt); El-Siragy, N. M. [Department of Physics, Faculty of Science, Tanta University, Tanta, P.O. 31527 (Egypt)

    2009-09-15T23:59:59.000Z

    Based on the quantum hydrodynamics theory, a proposed model for quantum dust acoustic waves (QDAWs) is presented including the dust size distribution (DSD) effect. A quantum version of Zakharov-Kuznetsov equation is derived adequate for describing QDAWs. Two different DSD functions are applied. The relevance of the wave velocity, amplitude, and width to the DSD is investigated numerically. The quantum effect changes only the soliton width. A brief conclusion is presented to the current findings and their relevance to astrophysics data is also discussed.

  16. Polarized light propagation in highly scattering turbid media with a distribution of the particle size: a Monte Carlo study

    E-Print Network [OSTI]

    Koh, Wonshill

    2013-02-22T23:59:59.000Z

    The light propagation in highly scattering turbid media composed of the particles with different size distribution is studied using a Monte Carlo simulation model implemented in Standard C. Monte Carlo method has been widely utilized to study...

  17. In situ diagnostic of the size distribution of nanoparticles generated by ultrashort pulsed laser ablation in vacuum

    SciTech Connect (OSTI)

    Bourquard, Florent; Loir, Anne-Sophie; Donnet, Christophe; Garrelie, Florence, E-mail: florence.garrelie@univ-st-etienne.fr [Université de Lyon, CNRS UMR 5516, Laboratoire Hubert Curien, Université Jean Monnet, Saint-Étienne (France)] [Université de Lyon, CNRS UMR 5516, Laboratoire Hubert Curien, Université Jean Monnet, Saint-Étienne (France)

    2014-03-10T23:59:59.000Z

    We aim to characterize the size distribution of nanoparticles located in the ablation plume produced by femtosecond laser interaction. The proposed method relies on the use of white-light extinction spectroscopy setup assisted by ultrafast intensified temporal gating. This method allows measurement of optical absorbance of a nickel nanoparticles cloud. Simulation of the extinction section of nickel nanoparticles size distributions has been developed in order to compare the measured optical absorbance to the optical extinction by theoretical and experimental nanoparticles size distributions (measured by scanning electron microscopy). A good agreement has been found between the in situ measured optical absorbance and the optical extinction cross section calculated from ex situ nanoparticles size distribution measurements.

  18. 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.

    2009-09-01T23:59:59.000Z

    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.

  19. Determination of aerosol size distributions at uranium mill tailings remedial action project sites

    SciTech Connect (OSTI)

    Newton, G.J.; Reif, R.H. [CWM Federal Environmental Services, Inc., Albuquerque, NM (United States); Hoover, M.D.

    1994-11-01T23:59:59.000Z

    The U.S. Department of Energy (DOE) has an ongoing program, the Uranium Mill Tailings Remedial Action (UMTRA) Project, to stabilize piles of uranium mill tailings in order to reduce the potential radiological hazards to the public. Protection of workers and the general public against airborne radioactivity during remedial action is a top priority at the UMTRA Project. The primary occupational radionuclides of concern are {sup 230}Th, {sup 226}Ra, {sup 210}Pb, {sup 210}Po, and the short-lived decay products of {sup 222}Rn with {sup 230}Th causing the majority of the committed effective dose equivalent (CEDE) from inhaling uranium mill tailings. Prior to this study, a default particle size of 1.0 {mu}m activity median aerodynamic diameter (AMAD) was assumed for airborne radioactive tailings dust. Because of recent changes in DOE requirements, all DOE operations are now required to use the CEDE methodology, instead of the annual effective dose equivalent (AEDE) methodology, to evaluate internal radiation exposures. Under the transition from AEDE to CEDE, with a 1.0 {mu}m AMAD particle size, lower bioassay action levels would be required for the UMTRA Project. This translates into an expanded internal dosimetry program where significantly more bioassay monitoring would be required at the UMTRA Project sites. However, for situations where the particle size distribution is known to differ significantly from 1.0 {mu}m AMAD, the DOE allows for corrections to be made to both the estimated dose to workers and the derived air concentration (DAC) values. For particle sizes larger than 1.0 {mu}m AMAD, the calculated CEDE from inhaling tailings would be relatively lower.

  20. DECODING THE MESSAGE FROM METEORITIC STARDUST SILICON CARBIDE GRAINS

    SciTech Connect (OSTI)

    Lewis, Karen M.; Lugaro, Maria; Gibson, Brad K.; Pilkington, Kate, E-mail: maria.lugaro@monash.edu, E-mail: karen.michelle.lewis@gmail.com, E-mail: bkgibson@uclan.ac.uk, E-mail: kpilkington@uclan.ac.uk [Monash Centre for Astrophysics (MoCA), Monash University, Clayton VIC 3800 (Australia)

    2013-05-01T23:59:59.000Z

    Micron-sized stardust grains that originated in ancient stars are recovered from meteorites and analyzed using high-resolution mass spectrometry. The most widely studied type of stardust is silicon carbide (SiC). Thousands of these grains have been analyzed with high precision for their Si isotopic composition. Here we show that the distribution of the Si isotopic composition of the vast majority of stardust SiC grains carries the imprints of a spread in the age-metallicity distribution of their parent stars and of a power-law increase of the relative formation efficiency of SiC dust with the metallicity. 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 modeling of dust condensation in stellar winds as a function of the metallicity.

  1. SURFACE AREA, VOLUME, MASS, AND DENSITY DISTRIBUTIONS FOR SIZED BIOMASS PARTICLES

    SciTech Connect (OSTI)

    Ramanathan Sampath

    2006-06-30T23:59:59.000Z

    This semi-annual technical progress report describes work performed at Morehouse College under DOE Grant No. DE-FC26-04NT42130 during the period January 01, 2006 to June 30, 2006 which covers the fourth six months of the project. Presently work is in progress to characterize surface area, volume, mass, and density distributions for sized biomass particles. During this reporting period, Morehouse completed obtaining additional mean mass measurements for biomass particles employing the gravimetric technique measurement system that was set up in a previous reporting period. Simultaneously, REM, our subcontractor, has completed obtaining raw data for surface area, volume, and drag coefficient to mass ratio (Cd/m) information for 9 more biomass particles employing the electrodynamic balance (EDB) measurement system that was calibrated before in this project. Results of the mean mass data obtained to date are reported here, and analysis of the raw data collected by REM is in progress.

  2. SURFACE AREA, VOLUME, MASS, AND DENSITY DISTRIBUTIONS FOR SIZED BIOMASS PARTICLES

    SciTech Connect (OSTI)

    Ramanathan Sampath

    2006-01-01T23:59:59.000Z

    This semi-annual technical progress report describes work performed at Morehouse College under DOE Grant No. DE-FC26-04NT42130 during the period July 01, 2005 to December 31, 2005 which covers the third six months of the project. Presently work is in progress to characterize surface area, volume, mass, and density distributions for sized biomass particles. During this reporting period, Morehouse continued to obtain additional mean mass measurements for biomass particles employing the gravimetric technique measurement system that was set up in the last reporting period. Simultaneously, REM, our subcontractor, has obtained raw data for surface area, volume, and drag coefficient to mass ratio (C{sub d}/m) information for several biomass particles employing the electrodynamic balance (EDB) measurement system that was calibrated in the last reporting period. Preliminary results of the mean mass and the shape data obtained are reported here, and more data collection is in progress.

  3. Use of ultrasound attenuation spectroscopy to determine the size distribution of clay tactoids in aqueous suspensions

    E-Print Network [OSTI]

    Samim Ali; Ranjini Bandyopadhyay

    2014-06-27T23:59:59.000Z

    The dispersion processes of aqueous samples of clay are studied using ultrasound attenuation spectroscopy. The attenuation spectra that are acquired in the frequency range $10-100$ MHz are used to determine the particle size distributions (PSDs) for different concentrations and ages of the clay suspensions. Our analysis, using equivalent spherical diameter (ESD) for circular discs under Stokes drag in samples of concentrations greater than 1.5\\% w/v, shows that a substantial fraction of the aggregates in suspension are actually tactoids that are composed of more than one platelet. This is in contrast to the general belief that clay disperses into individual platelets in the concentration range where their suspensions exhibit glassy behavior. We conclude that the incomplete fragmentation of the clay tactoids arises from the rapid enhancement of the inter-tactoid Coulombic repulsion.

  4. A General Systems Theory for Atmospheric Flows and Atmospheric Aerosol Size Distribution

    E-Print Network [OSTI]

    A. M. Selvam

    2011-07-25T23:59:59.000Z

    Atmospheric flows exhibit selfsimilar fractal spacetime fluctuations manifested as the fractal geometry to global cloud cover pattern and inverse power law form for power spectra of meteorological parameters such as windspeed, temperature, rainfall etc. Inverse power law form for power spectra indicate long-range spacetime correlations or non-local connections and is a signature of selforganised criticality generic to dynamical systems in nature such as river flows, population dynamics, heart beat patterns etc. The author has developed a general systems theory which predicts the observed selforganised criticality as a signature of quantumlike chaos in dynamical systems. The model predictions are (i) The fractal fluctuations can be resolved into an overall logarithmic spiral trajectory with the quasiperiodic Penrose tiling pattern for the internal structure. (ii) The probability distribution represents the power (variance) spectrum for fractal fluctuations and follows universal inverse power law form incorporating the golden mean. Such a result that the additive amplitudes of eddies when squared represent probability distribution is observed in the subatomic dynamics of quantum systems such as the electron or photon. Therefore the irregular or unpredictable fractal fluctuations exhibit quantumlike chaos. (iii) Atmospheric aerosols are held in suspension by the vertical velocity distribution (spectrum). The atmospheric aerosol size spectrum is derived in terms of the universal inverse power law characterizing atmospheric eddy energy spectrum. Model predicted spectrum is in agreement with the following two experimentally determined atmospheric aerosol data sets, (i) SAFARI 2000 CV-580 Aerosol Data, Dry Season 2000 (CARG) (ii) World Data Centre Aerosols data sets for the three stations Ny {\\AA}lesund, Pallas and Hohenpeissenberg.

  5. Collection strategy, inner morphology, and size distribution of dust particles in ASDEX Upgrade

    SciTech Connect (OSTI)

    M. Balden; N. Endstrasser; P. W. Humrickhouse; V. Rohde; M. Rasinski; U. von Toussaint; S. Elgeti; R. Neu

    2014-04-01T23:59:59.000Z

    The dust collection and analysis strategy in ASDEX Upgrade (AUG) is described. During five consecutive operation campaigns (2007–2011), Si collectors were installed, which were supported by filtered vacuum sampling and collection with adhesive tapes in 2009. The outer and inner morphology (e.g. shape) and elemental composition of the collected particles were analysed by scanning electron microscopy. The majority of the ~50?000 analysed particles on the Si collectors of campaign 2009 contain tungsten—the plasma-facing material in AUG—and show basically two different types of outer appearance: spheroids and irregularly shaped particles. By far most of the W-dominated spheroids consist of a solid W core, i.e. solidified W droplets. A part of these particles is coated with a low-Z material; a process that seems to happen presumably in the far scrape-off layer plasma. In addition, some conglomerates of B, C and W appear as spherical particles after their contact with plasma. By far most of the particles classified as B-, C- and W-dominated irregularly shaped particles consist of the same conglomerate with varying fraction of embedded W in the B–C matrix and some porosity, which can exceed 50%. The fragile structures of many conglomerates confirm the absence of intensive plasma contact. Both the ablation and mobilization of conglomerate material and the production of W droplets are proposed to be triggered by arcing. The size distribution of each dust particle class is best described by a log-normal distribution allowing an extrapolation of the dust volume and surface area. The maximum in this distribution is observed above the resolution limit of 0.28 µm only for the W-dominated spheroids, at around 1 µm. The amount of W-containing dust is extrapolated to be less than 300 mg on the horizontal areas of AUG.

  6. Combustion of sludge waste in FBC. Distribution of metals and particle sizes

    SciTech Connect (OSTI)

    Kozinski, J.A. [McGill Univ., Montreal, Quebec (Canada); Rink, K.K.; Lighty, J.S. [Univ. of Utah, Salt Lake City, UT (United States)

    1995-12-31T23:59:59.000Z

    Due to the increases in the amounts of sludge generated and increasingly stringent regulations regarding its disposal, alternative methods to landfilling are becoming more important. Fluidized bed combustion is one such alternative, providing permanent disposal of the sludge. In this research, metal-solid particle characteristics during combustion of a sludge waste were studied. The sludge was a result of de-inking process. Experiments were carried out using a pilot-scale circulating fluidized bed combustion facility (CFB). The fluidized bed was operated in the bubbling mode. The sludge was separately burned with silica sand particles, ultrasorb particles, and alumina particles as bed materials. Major flue gas components (CO{sub 2}, CO, O{sub 2}, NO, NO{sub 2}) were measured continuously. Gas temperature profiles were determined using a water-cooled suction pyrometer. Solid particle samples were collected at multiple locations using a dilution tunnel sampling system. The solid samples were analyzed to determine ash structure, size and composition distributions. Metal analyses were performed using a computer-controlled Electron Probe Microanalyzer (EPMA) equipped with four Wavelength-Dispersive Spectrometers. Analyses of individual fly ash particles indicated that heavy metal elements (Pb, Cd, Cr, Cu, Ni) were generally located in regions near the particle`s core. Lighter metals (Si, Al, Ca, Na, K) were present across the entire cross-section of a particle, with the highest concentrations at the particle surface. These distributions were found to be similar regardless of the type of bed material. This suggests that the light metal layers are formed because of the internal rearrangements of a chemical nature as opposed to physical deposition of light metal fragments on particle surfaces.

  7. Impacts of Venturi Turbulent Mixing on the Size Distributions of Sodium Chloride and Dioctyl-Phthalate Aerosols

    SciTech Connect (OSTI)

    Cheng, M-D.

    2000-08-23T23:59:59.000Z

    Internal combustion engines are a major source of airborne particulate matter (PM). The size of the engine PM is in the sub-micrometer range. The number of engine particles per unit volume is high, normally in the range of 10{sup 12} to 10{sup 14}. To measure the size distribution of the engine particles dilution of an aerosol sample is required. A diluter utilizing a venturi ejector mixing technique is commercially available and tested. The purpose of this investigation was to determine if turbulence created by the ejector in the mini-dilutor changes the size of particles passing through it. The results of the NaCl aerosol experiments show no discernible difference in the geometric mean diameter and geometric standard deviation of particles passing through the ejector. Similar results were found for the DOP particles. The ratio of the total number concentrations before and after the ejector indicates that a dilution ratio of approximately 20 applies equally for DOP and NaCl particles. This indicates the dilution capability of the ejector is not affected by the particle composition. The statistical analysis results of the first and second moments of a distribution indicate that the ejector may not change the major parameters (e.g., the geometric mean diameter and geometric standard deviation) characterizing the size distributions of NaCl and DOP particles. However, when the skewness was examined, it indicates that the ejector modifies the particle size distribution significantly. The ejector could change the skewness of the distribution in an unpredictable and inconsistent manner. Furthermore, when the variability of particle counts in individual size ranges as a result of the ejector is examined, one finds that the variability is greater for DOP particles in the size range of 40-150 nm than for NaCl particles in the size range of 30 to 350 nm. The numbers or particle counts in this size region are high enough that the Poisson counting errors are small (<10%) compared with the tail regions. This result shows that the ejector device could have a higher bin-to-bin counting uncertainty for ''soft'' particles such as DOP than for a solid dry particle like NaCl. The results suggest that it may be difficult to precisely characterize the size distribution of particles ejected from the mini-dilution system if the particle is not solid.

  8. 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. [Department of Chemical Engineering, University of Utah, Salt Lake City, UT (United States); D'Anna, Andrea [Dipartimento di Ingegneria Chimica, Universita ''Federico II'' di Napoli, Naples (Italy)

    2011-01-15T23:59:59.000Z

    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)

  9. Surface Area, Volume, Mass, and Density Distributions for Sized Biomass Particles

    SciTech Connect (OSTI)

    Ramanathan Sampath

    2007-06-30T23:59:59.000Z

    This final technical report describes work performed at Morehouse College under DOE Grant No. DE-FC26-04NT42130 during the period July 01, 2004 to June 30, 2007 which covers the entire performance period of the project. 25 individual biomass particles (hardwood sawdust AI14546 in the size range of 100-200 microns) were levitated in an electrodynamic balance (EDB) and their external surface area, volume, and drag coefficient/mass (C{sub d}/m) ratios were characterized applying highly specialized video based and high-speed diode array imaging systems. Analysis methods were employed using shape and drag information to calculate mass and density distributions for these particles. Results of these measurements and analyses were validated by independent mass measurements using a particle weighing and counting technique. Similar information for 28 PSOC 1451D bituminous coal particles was retrieved from a previously published work. Using these two information, density correlations for coal/biomass blends were developed. These correlations can be used to estimate the density of the blend knowing either the volume fraction or the mass fraction of coal in the blend. The density correlations presented here will be useful in predicting the burning rate of coal/biomass blends in cofiring combustors. Finally, a discussion on technological impacts and economic projections of burning biomass with coal in US power plants is presented.

  10. 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.

    2012-02-01T23:59:59.000Z

    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.

  11. Impacts of Venturi Turbulent Mixing on the Size Distribution of Sodium Chloride and Dioctyl-Phthalate Aerosols

    SciTech Connect (OSTI)

    Cheng, M.-D.; Wainman, T.; Storey, J.

    2000-08-01T23:59:59.000Z

    Internal combustion engines are a major source of airborne particulate matter (PM). The size of the engine PM is in the sub-micrometer range. The number of engine particles per unit volume is high, normally in the range of 10{sup 12} to 10{sup 14}. To measure the size distribution of the engine particles dilution of an aerosol sample is required. A diluter utilizing a venturi ejector mixing technique is commercially available and tested. The purpose of this investigation was to determine if turbulence created by the ejector in the mini-dilutor changes the size of particles passing through it.

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

    SciTech Connect (OSTI)

    Young, Sharissa Gay

    2005-09-01T23:59:59.000Z

    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 PSD data. Finally, the SSA of the three powders was measured using both permeametry and gas absorption methods, enabling the PSD to be linked to the SSA for these PETN powders. Consistent characterization of other PETN powders can be performed using the appropriate sample-specific preparation method, so that future studies can accurately identify the effect of changes in the PSD on the SSA and ultimately model EBW performance.

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

    E-Print Network [OSTI]

    Bolton, Malcolm

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

  14. Influence of Cement Particle-Size Distribution on Early Age Autogenous Strains and Stresses in Cement-Based Materials

    E-Print Network [OSTI]

    Bentz, Dale P.

    Influence of Cement Particle-Size Distribution on Early Age Autogenous Strains and Stresses in Cement-Based Materials Dale P. Bentz* Building and Fire Research Laboratory, National Institute-Jochen Haecker* Wilhelm Dyckerhoff Institut, 65203 Wiesbaden, Germany The influence of cement particle

  15. Size distribution of fine Particles in Stack emissions of a 600-MWe coal-fired Power Plant

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Size distribution of fine Particles in Stack emissions of a 600-MWe coal-fired Power Plant I coal-fired power plant. Aknowledgements: French environment agency ADEME (Contract number 04-74-C0018 that was carried out in March 2006 at a 600-MWe coal-fired power plant. 51 ineris-00973267,version1-4Apr2014 Author

  16. Three-dimensional Studies of Aerosol Ions and Their Size Distribution in East1 Asia During Spring 20012

    E-Print Network [OSTI]

    Sandu, Adrian

    2 condensation and gas phase ammonia distribution determine the nitrate size and32 gas observations. The regional27 chemical transport model, STEM-2K3, which includes the on-line gas-aerosol thermodynamic28 module SCAPE II, and explicitly considers chemical aging of dust is used in the analysis. The29

  17. 6/10/12 The use of acoustic inversion to estimate the bubble size distribution in pipelines | Science 5 Senses 1/4...globalproductivityforum.info/.../the-use-of-acoustic-inversion-to-estimate-the-bubble-size-distribu...

    E-Print Network [OSTI]

    Sóbester, András

    6/10/12 The use of acoustic inversion to estimate the bubble size distribution in pipelines method to more accurately measure gas bubbles in pipelines. The ability to measure gas bubbles in 2010. Currently, the most popular technique for estimating the gas bubble size distribution (BSD

  18. Comparison of the bubble size distribution in silicate foams using 2-dimensional images and 3-dimensional x-ray microtomography

    SciTech Connect (OSTI)

    Robert, G.; Baker, D.R.; Rivers, M.L.; Allard, E.; Larocque, J. (McGill); (UC)

    2005-02-03T23:59:59.000Z

    Three silicate glasses were hydrated at high pressure and then heated at atmospheric pressure to exsolve the water into bubbles and create foams. The bubble size distribution in these foams was measured by x-ray microtomography on the GSECARS BM-13 beamline at the Advanced Photon Source. The bubble area distributions were measured in two dimensions using the image slices produced from the microtomography and the software ImageJ. The bubble volume distributions were measured from the three-dimensional tomographic images with the BLOB3D software. We found that careful analysis of the microtomography data in both two and three dimensions was necessary to avoid the physically unrealistic, experimental artifact of identifying and counting many small bubbles whose surfaces were not defined by a septum of glass. When this artifact was avoided the foams demonstrated power-law distributions of bubble sizes in both two and three dimensions. Conversion of the power-law exponents for bubble areas measured in two dimensions to exponents for bubble volumes usually agreed with the measured three dimensional volume exponents. Furthermore, the power-law distributions for bubble volumes typically agree with multiple theories of bubble growth, all of which yield an exponent of 1 for the cumulative bubble volume distribution. The measured bubble volume distributions with exponents near 0.3 can be explained by diffusive growth as proposed by other authors, but distributions with exponents near 1.4 remain to be explained and are the subject of continuing research on the effects of water concentration and melt viscosity on foaming behavior.

  19. Effect of Particle Optical Properties on Size Distribution of Soils Obtained by Laser Diffraction

    E-Print Network [OSTI]

    Ahmad, Sajjad

    ) is essential infor- mation for those in the fields of engineering and environmental geosciences, sedimentology, sedimentology, pedology, etc. (Wen et al., 2002). In geotechnical practices, PSD and clay-size fraction of soils

  20. Ionization Cluster Size Distributions Created by Low Energy Electrons and Alpha Particles in Nanometric Track Segment in Gases

    E-Print Network [OSTI]

    Bantsar, Aliaksandr

    2012-01-01T23:59:59.000Z

    The interaction of ionizing radiation with nanometric targets is a field of interest for many branches of science such as: radiology, oncology, radiation protection and nanoelectronics. A new experimental technique known as nanodosimetry has been developed for the qualitative as well as quantitative description of these types of interactions. The work presented here is a contribution to this development, namely by further improvement of the new experimental technique called the Jet Counter, originally developed at the Andrzej So{\\l}tan Institute for Nuclear Studies. The Jet Counter is a unique device in the world for studying the interaction of low energy electrons with nanometer targets in the range 2-10 nm (in unit density). The basic experimental result is the frequency distribution of ionization cluster size produced by ionizing particles in a gaseous (nitrogen or propane) nanometric track segment. The first experimental data on the frequency distribution of ionization cluster size produced by low energy ...

  1. Raindrop size distributions and radar reflectivity-rain rate relationships for radar hydrology Hydrology and Earth System Sciences, 5(4), 615627 (2001) EGS

    E-Print Network [OSTI]

    Boyer, Edmond

    Raindrop size distributions and radar reflectivity-rain rate relationships for radar hydrology 615 Hydrology and Earth System Sciences, 5(4), 615­627 (2001) © EGS Raindrop size distributions and radar reflectivity­rain rate relationships for radar hydrology* Remko Uijlenhoet1 Sub-department Water Resources

  2. 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.

    1982-01-19T23:59:59.000Z

    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.

  3. Marine particle dynamics : sinking velocities, size distributions, fluxes, and microbial degradation rates

    E-Print Network [OSTI]

    McDonnell, Andrew M. P

    2011-01-01T23:59:59.000Z

    The sinking flux of particulate matter into the ocean interior is an oceanographic phenomenon that fuels much of the metabolic demand of the subsurface ocean and affects the distribution of carbon and other elements ...

  4. Development of laboratory and process sensors to monitor particle size distribution of industrial slurries (including shape characterization). Final technical report

    SciTech Connect (OSTI)

    Pendse, H.P.; Goetz, P.J.; Sharma, A.; Han, W; Bliss, T.C.

    1996-10-01T23:59:59.000Z

    The overall goal of the Particle Size Distribution (PSD) sensor projects was to develop and commercialize a sensor system capable of particle analysis, in terms of size distributions, using concentrated suspensions at high solids concentrations. The early research was focused on application of ultrasonic spectroscopy of inorganic pigment slurries (e.g. titanium dioxide) commonly encountered on paper industry. During the project prototypes were tested in both academic and industrial laboratories. Work also involved successful field tests of the on-line prototype at a pigment manufacturing facility. Pen Kem continued the work at its cost beyond the initial funded period from March `92 to September `94. The first project (DE- FC05-88CE40684), which began in September 1988, culminated in a commercial laboratory instrument, Pen Kem AcoustoPhor {trademark} 8000, put on the market in June 1993. The follow-on project was aimed at investigation of shape and orientation effects on ultrasonic spectroscopy. A new cooperative agreement was awarded in September 1994 (DE-FC05-94CE40005) to develop shape characterization capabilities deemed critical by the clay industry. This follow-on project achieved following successes: A theoretical model was developed to account for the effects of size-dependent aspect ratios of spheroid particles under different orientations on ultrasound attenuation spectra of concentrated slurries. The theoretical model was confirmed by laboratory tests on kaolin slurries. An algorithm was developed to simulate evolution of particle orientation fields in simple squeezing flows.

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

    SciTech Connect (OSTI)

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

    2013-07-22T23:59:59.000Z

    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 Brønsted acid concentrations of these two Ni/HBEA catalysts compared with the parent zeolite caused by the partial exchange of Brønsted 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.

  6. Inhalation toxicology of red and violet mixtures. Chamber concentration and particle-size distribution report

    SciTech Connect (OSTI)

    Higuchi, M.A.; Davies, D.W.

    1991-07-01T23:59:59.000Z

    An inhalation exposure facility was developed at the U.S. EPA, RTP, NC to conduct inhalation exposures of rodents and guinea pigs to dye mixtures used by the U.S. Army in the manufacture of smoke munitions. Initially, an evaluation of the prototype chamber aerosol homogeneity was conducted to determine the uniformity and reproducibility of the concentration and particle size of dye aerosol throughout the breathing zone of the test animals. The three dyes, DR11, SR1, and DB3, were chemically analyzed for purity and optically examined for size and shape. All pure dyes appeared to be stable at room temperature except DB3, which decomposes if not stored at 4 C. The particle size ranges varied for each pure dye and structures were either amorphous (azo dye) or crystalline (anthraquinone dyes). The bulk red and violet dye mixtures were analyzed for composition. The chemical analysis of the relative composition of each dye mixture, collected by cascade impactor sampling, revealed fractionation of the mixtures into component dyes.

  7. EVOLUTION OF DROPLET SIZE DISTRIBUTION AND AUTOCONVERSION PARAMETERIZATION IN TURBULENT CLOUDS

    E-Print Network [OSTI]

    .S. Department of Energy. The publisher by accepting the manuscript for publication acknowledges that the United or reproduce the published form of this manuscript, or allow others to do so, for United States Government condition (Weibull distribution) determined by the balance between diffusion and drift. Monte Carlo

  8. HII regions in spiral galaxies: Size distribution, luminosity function, and new isochrone diagnostics of density wave kinematics

    E-Print Network [OSTI]

    M. S. Oey; J. S. Parker; V. J. Mikles; X. Zhang

    2003-07-10T23:59:59.000Z

    We investigate the relationship of the HII region luminosity function (HII LF) to the HII region size distribution and density wave triggering in grand-design spiral galaxies. We suggest that the differential nebular size distribution is described by a power law of slope ~ -4, with flattening at radii below ~ 130 pc. This contrasts with the conventional exponential description, but it is physically and quantitatively consistent with the typical observed value of -2 for the HII LF slope. We have developed an interactive code that computes spatial isochrones for the evolving loci of spiral density waves in disk galaxies. This allows comparison of the nebular spatial distribution with the spatial isochrones for simple rotation curve parameters. Our comparisons for four grand-design galaxies suggest that the corotation radius r_co coincides with the outer ends of the star-forming arms. This value for r_co yields the best spatial correspondence between the HII regions and the isochrones, and also appears to yield a coincidence between the Inner Lindblad Resonance with the radial onset of star formation in the arms. Thus, we suggest that isochrones offer a new, simple, and effective technique for determining r_co, and thus the spiral pattern speed. However, application of the isochrones also demonstrates that evolution of the nebular population is difficult to spatially isolate in these galaxies.

  9. Autonomous grain combine control system

    DOE Patents [OSTI]

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

    2013-06-25T23:59:59.000Z

    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.

  10. Grain size effect on the semiconductor-metal phase transition characteristics of magnetron-sputtered VO{sub 2} thin films

    SciTech Connect (OSTI)

    Brassard, D.; Fourmaux, S.; Jean-Jacques, M.; Kieffer, J.C.; El Khakani, M. A. [Institut National de la Recherche Scientifique, INRS-Energie, Materiaux et Telecommunications, 1650, Boulevard Lionel-Boulet, C.P. 1020, Varennes, Quebec, J3X 1S2 (Canada)

    2005-08-01T23:59:59.000Z

    Single-phase vanadium dioxide (VO{sub 2}) thin films have been grown on Si{sub 3}N{sub 4}/Si substrates by means of a well-controlled magnetron sputtering process. The deposited VO{sub 2} films were found to exhibit a semiconductor-to-metal transition (SMT) at {approx}69 deg. C with a resistivity change as high as 3.2 decades. A direct and clear-cut correlation is established between the SMT characteristics (both amplitude and abruptness of the transition) of the VO{sub 2} films and their crystallite size.

  11. When the expansion of finite-size corrections to hydrogen Lamb shift in moments of charge distribution breaks down

    E-Print Network [OSTI]

    Hagelstein, Franziska

    2015-01-01T23:59:59.000Z

    We point out a limitation of the standard way of accounting the finite-size effects, i.e., when the leading $[(Z\\alpha)^4]$ and subleading $[(Z\\alpha)^5]$ contributions to the Lamb shift are given by the mean-square radius and the third Zemach moment of the charge distribution. This limitation may have profound consequences for the interpretation of the "proton size puzzle". We find, for instance, that the de R\\'ujula toy model of the proton form factor does not resolve the puzzle as claimed, despite the large value of the third Zemach moment. Given the formula which does not rely on the radii expansion, we show how tiny (less than a hundredth of percent) changes in the proton electric form factor at a MeV scale would be able to explain the puzzle.

  12. Indentation creep study on ultrafine-grained Zn processed by powder metallurgy

    E-Print Network [OSTI]

    Gubicza, Jenõ

    t Ultrafine-grained Zn (UFG-Zn) with the grain size of about 200 nm was processed by Spark Plasma Sintering

  13. The Impact of Oil Consumption Mechanisms on Diesel Exhaust Particle Size Distributions and Detailed Exhaust Chemical Composition

    SciTech Connect (OSTI)

    Stetter, J; Forster, N; Ghandhi, J; Foster, D

    2003-08-24T23:59:59.000Z

    Detailed exhaust emission data have been taken from a Cummins N-14 single cylinder research engine in which the oil consumption was varied by different engine modifications. Low sulfur fuel was used, and oil consumption was varied by modifying the intake valve stem seals, the exhaust valve stem seals, the oil control ring and combinations of these modifications. Detailed measurements of exhaust gas particle size distributions and chemical composition were made for the various oil consumption configurations for a range of engine loads and speeds. The particulate mass was measured with TEOM and traditional gravimetric filter methods. Filter data for EC/OC, sulfates and trace metals have been taken and analyzed. The trace metals in the particulate mass serve as the basis for assessing oil consumption at the different operating conditions. The data indicate that the oil consumption for the steady state testing done here was approximately an order of magnitude below oil consumption values cited in the literature. We did measure changes in the details of the chemical composition of the particulate for the different engine operating conditions, but it did not correlate with changes in the oil consumption. Furthermore, the data indicate that the particle size distribution is not strongly impacted by low level oil consumption variations observed in this work.

  14. Influence of attrition milling on nano-grain boundaries

    SciTech Connect (OSTI)

    Rawers, J.; Cook, D.

    1999-03-01T23:59:59.000Z

    Nanostructured materials have a relatively large proportion of their atoms associated with the grain boundary, and the method used to develop the nano-grains has a strong influence on the resulting grain boundary structure. In this study, attrition milling iron powders and blends of iron powders produced micron-size particles composed of nano-size grains. Mechanical cold-working powder resulted in dislocation generation, multiplication, and congealing that produced grain refinement. As the grain size approached nano-dimensions, dislocations were no longer sustained within the grain and once generated, rapidly diffused to the grain boundary. Dislocations on the grain boundary strained the local lattice structure which, as the grain size decreased, became the entire grain. Mechanical alloying of substitutional aluminium atoms into iron powder resulted in the aluminium atoms substituting for iron atoms in the grain boundary cells and providing a grain boundary structure similar to that of the iron powder processed in argon. Attrition milling iron powder in nitrogen gas resulted in nitrogen atoms being adsorbed onto the particle surface. Continued mechanical milling infused the nitrogen atoms into interstitial lattice sites on the grain boundary which also contributed to expanding and straining the local lattice.

  15. Millisecond dip events in the 2007 RXTE/PCA data of Sco X-1 and the TNO size distribution

    E-Print Network [OSTI]

    Chih-Yuan Liu; Hsiang-Kuang Chang; Jau-Shian Liang; Sun-Kun King

    2008-05-12T23:59:59.000Z

    Millisecond dips in the RXTE/PCA archival data of Sco X-1 taken from 1996 to 2002 were reported recently. Those dips were found to be most likely caused by instrumental dead time but may also contain some true astronomical events, which were interpreted as the occultation of X-rays from Sco X-1 by Trans-Neptunian Objects (TNO) of 100-m size. Here we report the results of search for millisecond dip events with the new RXTE/PCA data of Sco X-1 taken in year 2007. Adopting the same selection criteria as that in the previous study, we found only 3 dip events in 72-ks data, much fewer than the 107 events found in the 560-ks data taken from 1996 to 2002 reported earlier. The new data provides more detailed information of individual `very large events' (VLEs), which is not available in the old archival data. Although the number of VLEs does not obviously increase during the occurrence of dip events, all the 3 dip events are coincident in time with VLEs that have no flags set for any of the propane or the 6 main xenon anodes. It is a strong indication of instrumental effects. No significant dips which might be real occultation by 60 -- 100 m TNOs were observed. With only 72-ks data, however, the previously proposed possibility that about 10 percent of the dip events might not be instrumental still cannot be strictly excluded. Using the absence of those anomalous VLEs as the criterion for identifying non-instrumental dip events, we found, at a lower confidence level, 4 dip events of duration 8 - 10 ms in the 72-ks data. Upper limits to the size distribution of TNOs at the small size end are suggested.

  16. Simultaneous Retrieval of Effective Refractive Index and Density from Size Distribution and Light Scattering Data: Weakly-Absorbing Aerosol

    SciTech Connect (OSTI)

    Kassianov, Evgueni I.; Barnard, James C.; Pekour, Mikhail S.; Berg, Larry K.; Shilling, John E.; Flynn, Connor J.; Mei, Fan; Jefferson, Anne

    2014-10-01T23:59:59.000Z

    We propose here a novel approach for retrieving in parallel the effective density and real refractive index of weakly absorbing aerosol from optical and size distribution measurements. Here we define “weakly absorbing” as aerosol single-scattering albedos that exceed 0.95 at 0.5 um.The required optical measurements are the scattering coefficient and the hemispheric backscatter fraction, obtained in this work from an integrating nephelometer. The required size spectra come from a Scanning Mobility Particle Sizer and an Aerodynamic Particle Sizer. The performance of this approach is first evaluated using a sensitivity study with synthetically generated but measurement-related inputs. The sensitivity study reveals that the proposed approach is robust to random noise; additionally the uncertainties of the retrieval are almost linearly proportional to the measurement errors, and these uncertainties are smaller for the real refractive index than for the effective density. Next, actual measurements are used to evaluate our approach. These measurements include the optical, microphysical, and chemical properties of weakly absorbing aerosol which are representative of a variety of coastal summertime conditions observed during the Two-Column Aerosol Project (TCAP; http://campaign.arm.gov/tcap/). The evaluation includes calculating the root mean square error (RMSE) between the aerosol characteristics retrieved by our approach, and the same quantities calculated using the conventional volume mixing rule for chemical constituents. For dry conditions (defined in this work as relative humidity less than 55%) and sub-micron particles, a very good (RMSE~3%) and reasonable (RMSE~28%) agreement is obtained for the retrieved real refractive index (1.49±0.02) and effective density (1.68±0.21), respectively. Our approach permits discrimination between the retrieved aerosol characteristics of sub-micron and sub-10micron particles. The evaluation results also reveal that the retrieved density and refractive index tend to decrease with an increase of the relative humidity.

  17. Radiative torques on interstellar grains; 1, superthermal spinup

    E-Print Network [OSTI]

    Draine, B T; Weingartner, Joseph C

    1996-01-01T23:59:59.000Z

    Irregular dust grains are subject to radiative torques when irradiated by interstellar starlight. It is shown how these radiative torques may be calculated using the discrete dipole approximation. Calculations are carried out for one irregular grain geometry, and three different grain sizes. It is shown that radiative torques can play an important dynamical role in spinup of interstellar dust grains, resulting in rotation rates which may exceed even those expected from H_2 formation on the grain surface. Because the radiative torque on an interstellar grain is determined by the overall grain geometry rather than merely the state of the grain surface, the resulting superthermal rotation is expected to be long-lived. By itself, long-lived superthermal rotation would permit grain alignment by normal paramagnetic dissipation on the "Davis-Greenstein" timescale. However, radiative torques arising from anisotropy of the starlight background can act directly to alter the grain alignment on much shorter timescales, a...

  18. Evaluation of the modified Anderson sampler for determining particle size distributions and respirable concentrations of particulate matter present in the working environment of cottonseed oil mills

    E-Print Network [OSTI]

    Matlock, Stanley Wayne

    1976-01-01T23:59:59.000Z

    EVALUATION OF THE MODIFIED ANDERSON SAMPLER FOR DETERMINING PARTICLE SIZE DISTRIBUTIONS AND RESPIRABLE CONCENTRATIONS OF PARTICULATE MATTER PRESENT IN THE WORKING ENVIRONMENT OF COTTONSEED OIL MILLS A Thesis by STANLEY WAYNE MATLOCK Submitted... to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE August 1976 Major Subject: Agricultural Engineering FVALUATION OF THE MODIFIED ANDERSON SAMPLER FOR DETERMINING PARTICLE SIZE...

  19. Cement and Concrete Research, Vol. 42 (2), 404-409, 2012. Influence of Particle Size Distributions on Yield Stress and Viscosity of

    E-Print Network [OSTI]

    Bentz, Dale P.

    Cement and Concrete Research, Vol. 42 (2), 404-409, 2012. Influence of Particle Size Distributions on Yield Stress and Viscosity of Cement-Fly Ash Pastes Dale P. Bentz Chiara F. Ferraris Michael A. Galler.galler@nist.gov Phone: (301)975-5865 Andrew S. Hansen John M. Guynn Roman Cement LLC andrew@RomanCement.com Abstract

  20. A b s t r a c t. The paper presents a comparison of particle size distributions of 23 mineral soils from SE Poland obtained by the

    E-Print Network [OSTI]

    Ahmad, Sajjad

    fraction (sand). K e y w o r d s: mineral soils, particle size distribution, laser diffraction, areometric soils (Orthic Luvisols) and 1 black earth (Mollic Gleysol). Air-dry soil samples were sieved on 2 mm was prepared using distilled water as the liquid phase. To improve the credibility of results, the measurement

  1. Modeling kinetic partitioning of secondary organic aerosol and size distribution dynamics: representing effects of volatility, phase state, and particle-phase reaction

    SciTech Connect (OSTI)

    Zaveri, Rahul A.; Easter, Richard C.; Shilling, John E.; Seinfeld, J. H.

    2014-05-27T23:59:59.000Z

    Evidence is mounting that the majority of the climatically active aerosols are produced through the growth of smaller particles via secondary organic aerosol (SOA) formation from gas-to-particle conversion of anthropogenic and biogenic volatile organic compounds (VOCs). The timescale of SOA partitioning and the associated size distribution dynamics are expected to depend on the gas-phase oxidation of the precursor VOCs and their products, volatility of these organic solutes, composition and phase state of the pre-existing particles, and diffusivity and reactivity of the solute within the particle phase. This paper describes a new framework for modeling kinetic gas-particle partitioning of SOA, with an analytical treatment for the diffusion-reaction process within the particle phase. The formulation is amenable for eventual use in regional and global climate models, although it currently awaits implementation of the actual particle-phase reactions that are important for SOA formation. In the present work, the model is applied to investigate the competitive growth dynamics of the Aitken and accumulation mode particles while the Kelvin effect and coagulation are neglected for simplicity. The timescale of SOA partitioning and evolution of number and composition size distributions are evaluated for a range of solute volatilities (C*), particle-phase bulk diffusivities (Db), and particle-phase reactivity, as exemplified by a pseudo-first-order rate constant (kc). Results show that irreversible condensation of non-volatile organic vapors (equivalent to ) produces significant narrowing of the size distribution. At the other extreme, non-reactive partitioning of semi-volatile organic vapors is volume-controlled in which the final (equilibrium) size distribution simply shifts to the right on the diameter axis while its shape remains unchanged. However, appreciable narrowing of the size distribution may occur when the pre-existing particles are highly viscous semi-solids such that small particles reach quasi-equilibrium much faster than the large ones. In the case of reactive partitioning (finite ), the size distribution experiences permanent narrowing, which is especially pronounced for Db < 10-13 cm2 s-1 and kc > 0.01 s-1. As a result, both number and composition size distributions are needed to effectively constrain and evaluate the next generation of SOA models that treat phase state thermodynamics, particle-phase diffusion and particle-phase chemical reactions.

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

    SciTech Connect (OSTI)

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

    2015-01-01T23:59:59.000Z

    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 1000, 1300, and 1600°C 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 samples.

  3. Measurements of excess enthalpy in ultrafine-grained titanium dioxide

    SciTech Connect (OSTI)

    Terwilliger, C.D.; Chiang, Y.M. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Materials Science and Engineering

    1995-08-01T23:59:59.000Z

    Differential scanning calorimetry has been used to make direct measurements of the excess enthalpy of TiO{sub 2} (rutile) with an initial grain size of 30--70 nm. When the heat released during grain growth is normalized to the change in grain boundary area, the specific excess enthalpy at low temperature sn the fine grain sizes (600--780 C, 30--200 nm) is found to be 0.5--1 J/m{sup 2}, while values averaged over a larger temperature and size range (600--1,300 C, 30 nm-{approximately} 2 {micro}m) are 1.3--1.7 J/m{sup 2}. After exclusion of extraneous contributions from other heat-dissipating processes, origins of a specific grain boundary enthalpy that increases with grain size or temperature are considered, including solute segregation, changes in grain boundary structure, and contributions from grain boundary triple junctions. It is concluded that the most plausible explanation is a size-dependent nonstoichiometry of TiO{sub 2} due to the impingement of space charge layers in the temperature and grain size range of the experiments.

  4. DUST PROPERTIES AND DISK STRUCTURE OF EVOLVED PROTOPLANETARY DISKS IN Cep OB2: GRAIN GROWTH, SETTLING, GAS AND DUST MASS, AND INSIDE-OUT EVOLUTION

    SciTech Connect (OSTI)

    Sicilia-Aguilar, Aurora; Henning, Thomas; Dullemond, Cornelis P.; Bouwman, Jeroen; Sturm, Bernhard [Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, 69117 Heidelberg (Germany); Patel, Nimesh [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Juhasz, Attila, E-mail: sicilia@mpia.de, E-mail: aurora.sicilia@uam.es [Leiden Observatory, Niels Bohrweg 2, NL-2333 CA Leiden (Netherlands)

    2011-11-20T23:59:59.000Z

    We present Spitzer/Infrared Spectrograph spectra of 31 T Tauri stars (TTS) and IRAM/1.3 mm observations for 34 low- and intermediate-mass stars in the Cep OB2 region. Including our previously published data, we analyze 56 TTS and 3 intermediate-mass stars with silicate features in Tr 37 ({approx}4 Myr) and NGC 7160 ({approx}12 Myr). The silicate emission features are well reproduced with a mixture of amorphous (with olivine, forsterite, and silica stoichiometry) and crystalline grains (forsterite, enstatite). We explore grain size and disk structure using radiative transfer disk models, finding that most objects have suffered substantial evolution (grain growth, settling). About half of the disks show inside-out evolution, with either dust-cleared inner holes or a radially dependent dust distribution, typically with larger grains and more settling in the innermost disk. The typical strong silicate features nevertheless require the presence of small dust grains, and could be explained by differential settling according to grain size, anomalous dust distributions, and/or optically thin dust populations within disk gaps. M-type stars tend to have weaker silicate emission and steeper spectral energy distributions than K-type objects. The inferred low dust masses are in a strong contrast with the relatively high gas accretion rates, suggesting global grain growth and/or an anomalous gas-to-dust ratio. Transition disks in the Cep OB2 region display strongly processed grains, suggesting that they are dominated by dust evolution and settling. Finally, the presence of rare but remarkable disks with strong accretion at old ages reveals that some very massive disks may still survive to grain growth, gravitational instabilities, and planet formation.

  5. The Effect of Deformation on Grain Boundary Wetness in Partially Molten Peridotite

    E-Print Network [OSTI]

    Schneider, Stephen E.

    2006-07-11T23:59:59.000Z

    The spatial distribution of the melt phase can affect many properties of partially molten rocks, including viscosity and seismic wave velocity. A good way to quantify this distribution is the grain boundary wetness, the fraction of total grain...

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

    SciTech Connect (OSTI)

    Kozaczek, K.J. [Oak Ridge National Lab., TN (United States); Petrovic, B.G.; Ruud, C.O. [Pennsylvania State Univ., University Park, PA (United States); Mcllree, A.R. [Electric Power Research Inst., Palo Alto, CA (United States)

    1995-04-01T23:59:59.000Z

    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.

  7. Dust dynamics and evolution in expanding HII regions. I. Radiative drift of neutral and charged grains

    E-Print Network [OSTI]

    Akimkin, V V; Pavlyuchenkov, Ya N; Wiebe, D S

    2015-01-01T23:59:59.000Z

    We consider dust drift under the influence of stellar radiation pressure during the pressure-driven expansion of an HII region using the chemo-dynamical model MARION. Dust size distribution is represented by four dust types: conventional polycyclic aromatic hydrocarbons (PAHs), very small grains (VSGs), big grains (BGs) and also intermediate-sized grains (ISGs), which are larger than VSGs and smaller than BGs. The dust is assumed to move at terminal velocity determined locally from the balance between the radiation pressure and gas drag. As Coulomb drag is an important contribution to the overall gas drag, we evaluate a grain charge evolution within the HII region for each dust type. BGs are effectively swept out of the HII region. The spatial distribution of ISGs within the HII region has a double peak structure, with a smaller inner peak and a higher outer peak. PAHs and VSGs are mostly coupled to the gas. The mean charge of PAHs is close to zero, so they can become neutral from time to time because of char...

  8. Final Report: 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.

    2014-10-01T23:59:59.000Z

    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-particle direct capture from melt-solid growth instabilities, 2) Te-particle formation from dislocation core diffusion and the formation and breakup of Te-tubes, and 3) Te-particle formation due to classical nucleation and growth as precipitates.

  9. Study of catalytic diffusion in coal. Final report for 1983/1984 SOMED Project. [Determination of pore (hole) size and pore shape distribution

    SciTech Connect (OSTI)

    Kispert, L.D.

    1984-09-01T23:59:59.000Z

    The purpose of our studies is to determine the pore (hole) size and pore shape distribution in standard bituminous coal samples from various Alabama coal seams such as that of the Mary Lee, Black Creek and Pratt during and after swelling of the coal with different solvents at various temperatures. These samples come from the Penn State Coal Sample Bank at Pennsylvania State University Coal Research Section and from Alabama's Mineral Industries. Methods have been developed in the laboratory whereby free radical probes of varying sizes can be diffused into the coal under various conditions. These probes can be detected and the environment surrounding the probes can be deduced by electron paramagnetic resonance (EPR) methods. To date, we have found that not only can the shape and size of the pores be determined, but that the size distribution varies from one bituminous coal seam to another, even for coal of the same rank, suggesting a different optimal catalyst should be used for each seam. The effect of oxygen on the coal samples during grinding has been studied; however, the free radical technique appears to be insensitive to the presence of oxygen effects. It is our goal to determine the structural differences between various bituminous coals. 9 references, 9 figures, 1 table.

  10. Grain Refinement of Permanent Mold Cast Copper Base Alloys

    SciTech Connect (OSTI)

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

    2005-04-01T23:59:59.000Z

    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.

  11. 6/10/12 The use of acoustic inversion to estimate the bubble size distribution in pipelines | Global Scientia 1/2globalscientia.com/article/.../use-acoustic-inversion-estimate-bubble-size-distribution-pipelines

    E-Print Network [OSTI]

    Sóbester, András

    to expand and causes 'blow out'. A blow out is the sudden release of oil and/or gas from a well and issues with the blow out preventer were key in Deepwater Horizon oil spill (also known as the Macondo blowout) in the Gulf of Mexico in 2010. Currently, the most popular technique for estimating the gas bubble size

  12. 6/10/12 The use of acoustic inversion to estimate the bubble size distribution in pipelines 1/2www.sciencedaily.com/releases/2012/05/120515104537.htm

    E-Print Network [OSTI]

    Sóbester, András

    6/10/12 The use of acoustic inversion to estimate the bubble size distribution in pipelines 1/2www gas bubbles in pipelines. The ability to measure gas bubbles in pipelines is vital technique for estimating the gas bubble size distribution (BSD) is to send sound waves through the bubble

  13. Dislocation structure and crystallite size-distribution in hexagonal nanomaterials from X-ray peak profile analysis

    E-Print Network [OSTI]

    Gubicza, Jenõ

    profile analysis Tamás Ungár1 and Jen Gubicza1,2 1 Department of General Physics, Eötvös University crystal structure are studied by X-ray diffraction peak profile analysis. The crystallite size, X-ray peak profile analysis, hexagonal crystals, nanostructure. Short title: T. Ungár & J. Gubicza

  14. TABLE DR1. GRAIN SIZE DISTRIBUTIONS AND STATISTICS FOR MODELED HILLSLOPESUPPLIED SEDIMENT* Transect Number Distance Downstream d 10 d 50 d 90 Fraction coarser than in each sieve size

    E-Print Network [OSTI]

    Singer, Michael

    .00 27 13231.00 0.89 32.94 61.49 12.12 12.12 0.00 0.00 7.55 16.35 44.42 7.21 0.23 0.00 28 13845.00 0

  15. High-strain-rate nanoindentation behavior of fine-grained magnesium alloys

    E-Print Network [OSTI]

    Somekawa, Hidetoshi

    The effects of temperature and alloying elements on deformation in the high-strain-rate regime were investigated by testing fine-grained magnesium alloys with an average grain size of 2 ? 3 ?m by a nanoindentation technique. ...

  16. Power law and exponential ejecta size distributions from the dynamic fragmentation of shock-loaded Cu and Sn metals under melt conditions

    SciTech Connect (OSTI)

    Durand, O.; Soulard, L. [CEA, DAM, DIF, F-91297 Arpajon (France)

    2013-11-21T23:59:59.000Z

    Large scale molecular dynamics (MD) simulations are performed to study and to model the ejecta production from the dynamic fragmentation of shock-loaded metals under melt conditions. A generic 3D crystal in contact with vacuum containing about 10{sup 8} atoms and with a sinusoidal free surface roughness is shock loaded so as to undergo a solid-liquid phase change on shock. The reflection of the shock wave at the interface metal/vacuum gives rise to the ejection of 2D jets/sheets of atoms (Richtmyer-Meshkov instabilities in the continuum limit), which develop and break up, forming ejecta (fragments) of different volumes (or mass). The fragmentation process is investigated by analyzing the evolution of the resulting volume distribution of the ejecta as a function of time. Two metals are studied (Cu and Sn) and the amplitude of the roughness is varied. The simulations show that the associated distributions exhibit a generic behavior with the sum of two distinct terms of varying weight, following the expansion rate of the jets: in the small size limit, the distribution obeys a power law dependence with an exponent equal to 1.15?±?0.08; and in the large size limit, it obeys an exponential form. These two components are interpreted, with the help of additional simple simulations, as the signature of two different basic mechanisms of fragmentation. The power law dependence results from the fragmentation of a 2D network of ligaments arranged following a fractal (scale free) geometry and generated when the sheets of liquid metal expand and tear. The exponential distribution results from a 1D Poisson fragmentation process of the largest ligaments previously generated. Unlike the power law distribution, it is governed by a characteristic length scale, which may be provided by energy balance principle.

  17. Do grain boundaries in nanophase metals slide?

    SciTech Connect (OSTI)

    Bringa, E M; Leveugle, E; Caro, A

    2006-10-27T23:59:59.000Z

    Nanophase metallic materials show a maximum in strength as grain size decreases to the nano scale, indicating a break down of the Hall-Petch relation. Grain boundary sliding, as a possible accommodation mechanisms, is often the picture that explain computer simulations results and real experiments. In a recent paper, Bringa et al. Science 309, 1838 (2005), we report on the observation of an ultra-hard behavior in nanophase Cu under shock loading, explained in terms of a reduction of grain boundary sliding under the influence of the shock pressure. In this work we perform a detailed study of the effects of hydrostatic pressure on nanophase Cu plasticity and find that it can be understood in terms of pressure dependent grain boundary sliding controlled by a Mohr-Coulomb law.

  18. 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

    2008-02-12T23:59:59.000Z

    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.

  19. crockpot beans and grains

    E-Print Network [OSTI]

    CROCKPOT BEANS AND GRAINS 1 cup dried beans, soaked overnight and drained (I used navy beans this time, but I've used kidney beans and others would ...

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

    SciTech Connect (OSTI)

    Babu, N. Kishore [Singapore Institute of Manufacturing Technology; Cross, Carl E. [Los Alamos National Laboratory

    2012-06-28T23:59:59.000Z

    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. Radiative Torques on Interstellar Grains: I. Superthermal Spinup

    E-Print Network [OSTI]

    B. T. Draine; Joseph C. Weingartner

    1996-05-09T23:59:59.000Z

    Irregular dust grains are subject to radiative torques when irradiated by interstellar starlight. It is shown how these radiative torques may be calculated using the discrete dipole approximation. Calculations are carried out for one irregular grain geometry, and three different grain sizes. It is shown that radiative torques can play an important dynamical role in spinup of interstellar dust grains, resulting in rotation rates which may exceed even those expected from H_2 formation on the grain surface. Because the radiative torque on an interstellar grain is determined by the overall grain geometry rather than merely the state of the grain surface, the resulting superthermal rotation is expected to be long-lived. By itself, long-lived superthermal rotation would permit grain alignment by normal paramagnetic dissipation on the "Davis-Greenstein" timescale. However, radiative torques arising from anisotropy of the starlight background can act directly to alter the grain alignment on much shorter timescales, and are therefore central to the process of interstellar grain alignment. Radiative torques depend strongly on the grain size, measured by a_eff, the radius of a sphere of equal volume. In diffuse clouds, radiative torques dominate the torques due to H2 formation for a_eff=0.2micron grains, but are relatively unimportant for a_eff0.1 micron grains in diffuse clouds are aligned, while there is little alignment of a_eff superthermal rotation within quiescent dark clouds, but can be very effective in star-forming regions such as the M17 molecular cloud.

  2. 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.

    2009-12-01T23:59:59.000Z

    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.

  3. Preliminary investigation of the role that DMS (dimethyl sulfide) and cloud cycles play in the formation of the aerosol size distribution. Interim report

    SciTech Connect (OSTI)

    Hoppel, W.A.; Fitzgerald, J.W.; Frick, G.M.; Larson, R.E.; Wattle, B.J.

    1987-07-29T23:59:59.000Z

    A series of experiments designed to study the production of new particulate matter by photolysis of dimethyl sulfide (DMS) and the effect that nonprecipitating clouds have on the aerosol size distributions were carried out in Calspan Corporation's 600 cum environmental chamber during January and February 1986. The results show that DMS, the most-abundant natural source of sulfur, is photooxidized to some product of low volatility that can form new particles by homogeneous nucleation or condense on existing aerosols causing them to grow. To explain these observations, a theoretical study of the nucleation properties of methane sulfonic acid (MSA) was undertaken. The nucleation thresholds, calculated using thermodynamic data for MSA, show that at 70% RH, and MSA concentration of only 0.006 ppb will result in a supersaturated environment in which MSA will condense on preexisting particles larger than 0.02-micron radius. If the MSA concentrations increase to 30 ppb, then spontaneous formation of MSA solution droplets occurs by homogeneous binary nucleation. Simulations of the evolution of the size distribution observed for the DMS irradiation experiments with a dynamic aerosol model that includes the effects of coagulation, growth by condensation, and deposition to the walls of the chamber, yield results that are in excellent agreement with the observed evolution.

  4. Millisecond dip events in the 2007 RXTE/PCA data of Sco X-1 and the TNO size distribution

    E-Print Network [OSTI]

    Liu, Chih-Yuan; Liang, Jau-Shian; King, Sun-Kun

    2008-01-01T23:59:59.000Z

    Millisecond dips in the RXTE/PCA archival data of Sco X-1 taken from 1996 to 2002 were reported recently. Those dips were found to be most likely caused by instrumental dead time but may also contain some true astronomical events, which were interpreted as the occultation of X-rays from Sco X-1 by Trans-Neptunian Objects (TNO) of 100-m size. Here we report the results of search for millisecond dip events with the new RXTE/PCA data of Sco X-1 taken in year 2007. Adopting the same selection criteria as that in the previous study, we found only 3 dip events in 72-ks data, much fewer than the 107 events found in the 560-ks data taken from 1996 to 2002 reported earlier. The new data provides more detailed information of individual `very large events' (VLEs), which is not available in the old archival data. Although the number of VLEs does not obviously increase during the occurrence of dip events, all the 3 dip events are coincident in time with VLEs that have no flags set for any of the propane or the 6 main xeno...

  5. 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)

    2012-02-01T23:59:59.000Z

    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.

  6. Size-dependent solute segregation and total solubility in ultrafine polycrystals: Ca in TiO[sub 2

    SciTech Connect (OSTI)

    Terwilliger, C.D.; Chiang, Y.M. (Massachusetts Inst. of Technology, Cambridge, MA (United States). Dept. of Materials Science and Engineering)

    1995-01-01T23:59:59.000Z

    Grain boundary segregation at ultrafine grain sizes has been studied. Using a STEM microanalysis technique to quantify the grain boundary coverage of calcium (0.34 mol%) in TiO[sub 2] ranging in grain size from 50 to 750 nm, it is found that below grain sizes of 150--350 nm, segregation deviates from conventional isotherms, exhibiting a clear size dependence. In this size regime the interfacial area to volume ratio is as important as temperature and composition in determining grain boundary coverage. In the present system, grain boundaries become saturated with calcium when the coverage reaches approximately one half of an equivalent monolayer. The experimental results can be modeled by a statistical thermodynamical treatment of segregation which takes into account the large density of grain boundary sites in this size range. The authors also find direct evidence of enhanced total solubility at very fine grain sizes due to grain boundary segregation.

  7. Fine Grained Robotics

    E-Print Network [OSTI]

    Flynn, Anita M.

    Fine grained robotics is the idea of solving problems utilizing multitudes of very simple machines in place of one large complex entity. Organized in the proper way, simple machines and simple behaviors can lead to emergent ...

  8. Small Grains for Forage.

    E-Print Network [OSTI]

    Holt, Ethan C.

    1959-01-01T23:59:59.000Z

    for both early and sustained production. Further testing of these varieties is underway. Otller varieties may be used satisfactorily, but the ones named have given the most consistent performance. Small grain varieties differ in growth habit, some... carried out at Crys- tal City to determine the import- ance of stage of growth at first clipping and frequency of clipping on small grain forage yields. These results are presented in Table 1. Under both field ancl greenhouse conditions...

  9. Estimating Corn Grain Yields

    E-Print Network [OSTI]

    Blumenthal, Jurg M.; Thompson, Wayne

    2009-06-12T23:59:59.000Z

    can collect samples from a corn field and use this data to calculate the yield estimate. An interactive grain yield calculator is provided in the Appendix of the pdf version of this publication. The calculator is also located in the publication.... Plan and prepare for sample and data collection. 2. Collect field samples and record data. 3. Analyze the data using the interactive grain yield calculator in the Appendix. Plan and prepare for sample and data collection Predetermine sample locations...

  10. Effect of coal type, residence time, and combustion configuration on the submicron aerosol composition and size distribution from pulverized coal combustion

    SciTech Connect (OSTI)

    Linak, W.P.

    1985-01-01T23:59:59.000Z

    Pulverized samples of Utah bituminous, Beulah (North Dakota) low Na lignite, Deulah high Na lignite and Texas (San Miguel) lignite coals were burned at a rate of 2.5 kg/hr in a laboratory furnace under various (overall fuel lean) combustion conditions. Particle size distributions (PSD) and size segregated particle filter samples were taken at various positions within the convection section. Temperature and gas concentrations were measured throughout. The evolution of the submicron PSD within the convection section for the four coals was similar, although the location of the initial particle mode at the convection section inlet varied with coal type. While stage combustion of the Utah bituminous coal had a variable effect on the volume of submicron aerosol produced, staged combustion of two of the three lignites (Beulah low Na and Texas) caused a definite increase in the submicron aerosol volume. Chemical analysis of the size segregated particle samples show the trace elements, As, Pb, Zn, and the major elements, Na and K to be enriched in the submicron aerosol. Auger depth profiles show these small particles to be comprised of a core enriched in Fe, Si, Ca and Mg and surface layers enriched in Na and K. These results point to a mechanism of homogeneous nucleation of low vapor pressure species followed by successive layering of progressively more volatile species. Volatile species are enriched in the submicron aerosol due to the large surface areas provided. Modeling efforts show that while coagulation may be the dominant mechanism to describe the aerosol evolving within the convection section, it cannot be used solely to predict the PSD. Another mechanism, presumably surface area dependent growth (condensation) must be included.

  11. Drying and Storing Sorghum Grain.

    E-Print Network [OSTI]

    Hutchison, J. E.

    1959-01-01T23:59:59.000Z

    Drying and Storing Sorghum Grain W. S. ALLEN AND J. W. SORENSON. JR.* lead to insect. niold and heat damage in stored grain. They cause most of the problems encountered in storing grain. High moisture may result from leak- age of outside... moisture through hin walls or from placing high-moisture grain in storage. If the following recornrnendations and procedures are followed. sorghum grain can be stored safely. The! are based on research conducted at Beeville by the Texas Agricultural...

  12. 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

    2012-06-28T23:59:59.000Z

    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.

  13. ARM - Measurement - Particle size distribution

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP : XDCnarrowband upwelling irradiancenumber concentration ARM Datasize

  14. Bulk ultrafine-grained Nickel consolidated from nanopowders J. Gubicza1,a

    E-Print Network [OSTI]

    Gubicza, Jenõ

    ), Spark Plasma Sintering (SPS), microstructure, mechanical properties. Abstract. Ultrafine-grained samples Pressing (HIP) and Spark Plasma Sintering (SPS). The higher nickel-oxide content and the smaller grain size) and Spark Plasma Sintering (SPS). Moreover, the influence of the initial powder particle size is also

  15. Physical and chemical properties of the regional mixed layer of Mexico's Megapolis – Part II: Evaluation of measured and modeled trace gases and particle size distributions

    SciTech Connect (OSTI)

    Ochoa, Carlos; Baumgardner, Darrel; Grutter, M.; Allan, James D.; Fast, Jerome D.; Rappengluck, B.

    2012-10-31T23:59:59.000Z

    This study extends the work of Baumgardner et al. (2009) in which measurements of trace gases and particles at a remote, high-altitude mountain site 60 km from Mexico City were analyzed with respect to the origin of air masses. In the current evaluation, the temperature, water vapor, ozone (O3), carbon monoxide (CO), acyl peroxy nitrate (APN) and particle size distributions (PSDs) of the mass concentrations of sulfate, nitrate, ammonium and organic mass (OM) were simulated with the WRF-Chem chemical transport model and compared with the measurements at the mountain site. The model prediction of the diurnal trends of the gases were well correlated with the measurements before the regional boundary layer reached the measurement site but underestimated the concentrations after that time. The differences are caused by an overly rapid growth of the boundary layer by the model with too much dilution. There also appears to be more O3 produced by photochemical production, downwind of the emission sources, than predicted by the model. The measured and modeled PSDs compare very well with respect to their general shape and diameter of the peak concentrations. The spectra are log normally distributed with most of the mass in the accumulation mode and the geometric diameter centered at 200 ±20 nm, with little observed or predicted change with respect to the origin of the air mass or the time when the RBL is above the Altzomoni research. Only the total mass changed with time and air mass origin. The invariability of the average diameter of the accumulation mode suggests that there is very little growth of the particles by condensation or coagulation after six hours of aging downwind of the major sources of anthropogenic emissions in Mexico’s Megapolis.

  16. Grains, Water Introduction

    E-Print Network [OSTI]

    Wirosoetisno, Djoko

    Grains, Water & Wet Sand Onno Bokhove Introduction Dry Granular Chute Flows: Cantilever Water Waves: Bores Near the Shore Surf Induced Sand Dynamics Discussion Dry Granular Flows, Water Waves & Surf, Water & Wet Sand Onno Bokhove Introduction Dry Granular Chute Flows: Cantilever Water Waves: Bores Near

  17. Considerations When Using Grain Contracts

    E-Print Network [OSTI]

    Wisner, Robert; McCorkle, Dean

    2000-04-07T23:59:59.000Z

    Grain contracts can help farmers manage the increasing risks of production and the price volatility of the market. This publication explains grain contracts and how to use them wisely as a risk management tool....

  18. Knowing and Managing Grain Basis

    E-Print Network [OSTI]

    Amosson, Stephen H.; Mintert, James R.; Tierney Jr., William I.; Waller, Mark L.

    1999-06-23T23:59:59.000Z

    Knowing and Managing Grain Basis Stephen Amosson, Jim Mintert, William Tierney and Mark Waller* Differences in grain prices throughout the world are the result of surplus or deficit production in various regions. In general, grain prices are lower... in the inland producing regions and higher in grain-deficit, densely populated and port regions. Distances between producing and consuming regions explain the price differential. Transfer costs, which include loading or handling and transportation charges...

  19. Process for producing large grain cadmium telluride

    DOE Patents [OSTI]

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

    1996-01-16T23:59:59.000Z

    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.

  20. Determination of thermodynamic and kinetic properties of grain boundaries using high temperature calorimetry

    SciTech Connect (OSTI)

    Terwilliger, C.D.; Chiang, Y.M. (Massachusetts Inst. of Tech., Cambridge, MA (USA)); Eastman, J.A.; Liao, Y. (Argonne National Lab., IL (USA))

    1991-06-01T23:59:59.000Z

    This work explores the use of high temperature differential scanning calorimetry as a novel way in which to measure thermodynamic and kinetic properties of grain boundaries in ceramics. A calorimetric study of grain growth has become practical only recently, with the development of processing methods for nanocrystalline materials (10--50 nm grain size) that have enough grain boundary area and thus grain boundary excess properties to be detected by commercial calorimeters. Here we report results from experiments on nanocrystalline silicon and titanium dioxide. 14 refs., 6 figs.

  1. Effect of acicular ferrite formation on grain refinement in the coarse-grained region of heat-affected zone

    SciTech Connect (OSTI)

    Wan, X.L.; Wei, R. [Institute of Advanced Steels and Welding Technology, Hubei Provincial Key Laboratory for Systems Science on Metallurgical Processing, Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education, Wuhan University of Science and Technology, Wuhan 430081 (China); Wu, K.M., E-mail: wukaiming@wust.edu.cn [Institute of Advanced Steels and Welding Technology, Hubei Provincial Key Laboratory for Systems Science on Metallurgical Processing, Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education, Wuhan University of Science and Technology, Wuhan 430081 (China)

    2010-07-15T23:59:59.000Z

    The microstructure of acicular ferrite and its formation for the grain refinement of coarse-grained region of heat-affected zone of high strength low-alloy bainite steels were studied using three-dimensional reconstruction technique. Crystallographic grain size was analyzed by means of electron backscatter diffraction. It was revealed that the microstructure in the coarse-grained region of the heat-affected zone consisted of predominantly bainite packets and a small proportion of acicular ferrite. Acicular ferrite was of lath or plate-like rather than needle or rod-like morphology. Tempering of the coarse-grained region of heat-affected zone showed that the acicular ferrite was more stable than the bainite, indicating that the acicular ferrite was formed prior to bainite. The acicular ferrite laths or plates divided the prior austenite grains into smaller and separate regions, and confining the bainite transformed at lower temperatures in the smaller regions and hence leading to the grain refinement in the coarse-grained region of the heat-affected zone.

  2. Grain Destruction in Interstellar Shocks

    E-Print Network [OSTI]

    B. T. Draine

    1995-08-16T23:59:59.000Z

    Interstellar shock waves can erode and destroy grains present in the shocked gas, primarily as the result of sputtering and grain-grain collisions. Uncertainties in current estimates of sputtering yields are reviewed. Results are presented for the simple case of sputtering of fast grains being stopped in cold gas. An upper limit is derived for sputtering of refractory grains in C-type MHD shocks: shock speeds $v_s \\gtrsim 50 \\kms$ are required for return of more than 30\\% of the silicate to the gas phase. Sputtering can also be important for removing molecular ice mantles from grains in two-fluid MHD shock waves in molecular gas. Recent estimates of refractory grain lifetimes against destruction in shock waves are summarized, and the implications of these short lifetimes are discussed.

  3. NanoSIMS analysis of arsenic and selenium in cereal grain

    SciTech Connect (OSTI)

    Moore, Katie L.; Schröder, Markus; Lombi, Enzo; Zhao, Fang-Jie; McGrath, Steve P.; Hawkesford, Malcolm J.; Shewry, Peter R.; Grovenor, Chris R.M. (Rothamsted); (UCopenhagen); (Oxford)

    2012-09-05T23:59:59.000Z

    Cereals are an important source of selenium (Se) to humans and many people have inadequate intakes of this essential trace element. Conversely, arsenic (As) is toxic and may accumulate in rice grain at levels that pose a health risk. Knowledge of the localization of selenium and arsenic within the cereal grain will aid understanding of their deposition patterns and the impact of processes such as milling. High-resolution secondary ion mass spectrometry (NanoSIMS) was used to determine the localization of Se in wheat (Triticum aestivum) and As in rice (Oryza sativa). Combined synchrotron X-ray fluorescence (S-XRF) and NanoSIMS analysis utilized the strengths of both techniques. Selenium was concentrated in the protein surrounding the starch granules in the starchy endosperm cells and more homogeneously distributed in the aleurone cells but with Se-rich hotspots. Arsenic was concentrated in the subaleurone endosperm cells in association with the protein matrix rather than in the aleurone cells. NanoSIMS indicated that the high intensity of As identified in the S-XRF image was localized in micron-sized hotspots near the ovular vascular trace and nucellar projection. This is the first study showing subcellular localization in grain samples containing parts per million concentrations of Se and As. There is good quantitative agreement between NanoSIMS and S-XRF.

  4. Technical Letter Report Development of Flaw Size Distribution Tables Including Effects of Flaw Depth Sizing Errors for Draft 10CFR 50.61a (Alternate PTS Rule) JCN-N6398, Task 4

    SciTech Connect (OSTI)

    Simonen, Fredric A.; Gosselin, Stephen R.; Doctor, Steven R.

    2013-04-22T23:59:59.000Z

    This document describes a new method to determine whether the flaws in a particular reactor pressure vessel are consistent with the assumptions regarding the number and sizes of flaws used in the analyses that formed the technical justification basis for the new voluntary alternative Pressurized Thermal Shock (PTS) rule (Draft 10 CFR 50.61a). The new methodology addresses concerns regarding prior methodology because ASME Code Section XI examinations do not detect all fabrication flaws, they have higher detection performance for some flaw types, and there are flaw sizing errors always present (e.g., significant oversizing of small flaws and systematic under sizing of larger flaws). The new methodology allows direct comparison of ASME Code Section XI examination results with values in the PTS draft rule Tables 2 and 3 in order to determine if the number and sizes of flaws detected by an ASME Code Section XI examination are consistent with those assumed in the probabilistic fracture mechanics calculations performed in support of the development of 10 CFR 50.61a.

  5. austenite grain size: Topics by E-print Network

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

    105 mathrmcm-3)-14 (where tmathrmff is the free-fall time at hydrogen number density nmathrmH in the core, and S the enhancement factor to the...

  6. adsorbent grain size: Topics by E-print Network

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

    105 mathrmcm-3)-14 (where tmathrmff is the free-fall time at hydrogen number density nmathrmH in the core, and S the enhancement factor to the...

  7. austenitc grain size: Topics by E-print Network

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

    105 mathrmcm-3)-14 (where tmathrmff is the free-fall time at hydrogen number density nmathrmH in the core, and S the enhancement factor to the...

  8. alloy grain size: Topics by E-print Network

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

    105 mathrmcm-3)-14 (where tmathrmff is the free-fall time at hydrogen number density nmathrmH in the core, and S the enhancement factor to the...

  9. Grain constraint and size effects in shape memory alloy microwires

    E-Print Network [OSTI]

    Ueland, Stian Melhus

    2013-01-01T23:59:59.000Z

    Shape memory alloys exhibit interesting and useful properties, such as the shape memory effect and superelasticity. Among the many alloy families that have been shown to exhibit shape memory properties the ones based on ...

  10. Modeling of stresses at grain boundaries with respect to occurrence of stress corrosion cracking

    SciTech Connect (OSTI)

    Kozaczek, K.J. [Oak Ridge National Lab., TN (United States); Sinharoy, A.; Ruud, C.O. [Pennsylvania State Univ., University Park, PA (United States); McIlree, A.R. [Electric Power Research Institute, Palo Alto, CA (United States)

    1995-12-31T23:59:59.000Z

    The distributions of elastic stresses/strains in the grain boundary regions were studied by the analytical and the finite element models. The grain boundaries represent the sites where stress concentration occurs as a result of discontinuity of elastic properties across the grain boundary and the presence of second phase particles elastically different from the surrounding matrix grains. A quantitative analysis of those stresses for steels and nickel based alloys showed that the stress concentrations in the grain boundary regions are high enough to cause a local microplastic deformation even when the material is in the macroscopic elastic regime. The stress redistribution as a result of such a plastic deformation was discussed.

  11. MIXTURES OF FINE-GRAINED MINERALS KAOLINITE AND CARBONATE GRAINS

    E-Print Network [OSTI]

    Palomino, Angelica M.

    MIXTURES OF FINE-GRAINED MINERALS À KAOLINITE AND CARBONATE GRAINS ANGELICA M. PALOMINO 1, *, SUSAN, Georgia 30332-0355, USA Abstract--The behavior of mineral mixtures can be significantly different from properties of the individual minerals, and their ensuing effects on interparticle interactions and fabric

  12. Radiative Torques on Interstellar Grains; 2, Grain Alignment

    E-Print Network [OSTI]

    Draine, B T; Weingartner, Joseph C.

    1996-01-01T23:59:59.000Z

    Radiative torques on irregular dust grains, in addition to producing superthermal rotation, play a direct dynamical role in the alignment of interstellar dust with the local magnetic field. The equations governing the orientation of spinning, precessing grains are derived; H_2 formation torques and paramagnetic dissipation are included in the dynamics. Stationary solutions (constant alignment angle and spin rate) are found; these solutions may be stable ("attractors") or unstable ("repellors"). The equations of motion are numerically integrated for three exemplary irregular grain geometries, exposed to anisotropic radiation with the spectrum of interstellar starlight. The resulting "trajectory maps" are classified as "noncyclic", "semicyclic", or "cyclic", with examples of each given. We find that radiative torques result in rapid grain alignment, even in the absence of paramagnetic dissipation. It appears that radiative torques due to starlight can account for the observed alignment of interstellar grains wi...

  13. Dehumidification Grain Dryer

    SciTech Connect (OSTI)

    Lula, J.W.; Bohnert, G.W.

    1998-05-13T23:59:59.000Z

    A new technique developed during this project dries grain with mildly heated, dehumidified air in a closed-loop process. This proposed technique uses about one-tenth the energy and dries grain at a lower temperature, producing less damage to the kernels.Approximately 250 million automotive and truck tires are discarded each year in the U.S. The very properties that ensure a safe ride and long service life make the disposal of these scrap tires difficult. In spite of this, scrap tire recycling/reuse has rapidly grown from 10% in 1985 to over 90% today. The majority of scrap tires that are recycled/reused are burned for fuel in power plants and cement kilns. Since tires have somewhat higher heating value than coal, this would at first seem to be an acceptable option. But burning scrap tires recovers only 25% of the energy originally used to manufacture the rubber. An alternative is to use the scrap tires in the form of crumb rubber, by which 98% of the original energy is recovered. This project sought to explore potential formulations of crumb rubber with various thermoplastic binders, with one goal being developing a material for a low-cost, high-performance roofing composition. What was the state-of-the-art of the product/process prior to initiation of the project? Why was the project needed (e.g., performance, quality, cost, time to market)? Describe the strengths and interests of each party and how they are complementary with respect to the project. What KCP expertise was needed and how did it complement the partner's capabilities?

  14. 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. [Department of Physics, Queens College of CUNY, Queens, New York 11367 (United States); The Graduate Center of CUNY, New York, New York 10016 (United States); Shuvayev, Vladimir [Department of Physics, Queens College of CUNY, Queens, New York 11367 (United States); Deligiannakis, Vasilios; Tamargo, Maria C. [The Graduate Center of CUNY, New York, New York 10016 (United States); Department of Chemistry, City College of CUNY, New York, New York 10031 (United States); Ludwig, Jonathan [National High Magnetic Field Laboratory, Tallahassee, Florida 32310 (United States); Department of Physics, Florida State University, Tallahassee, Florida 32306 (United States); Smirnov, Dmitry [National High Magnetic Field Laboratory, Tallahassee, Florida 32310 (United States); Wang, Alice [Evans Analytical Group, Sunnyvale, California 94086 (United States)

    2014-10-28T23:59:59.000Z

    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.

  15. INFLUENCE DES DIMENSIONS DE GRAINS SUR L'ANOMALIE DE LA RSISTIVIT DU NICKEL

    E-Print Network [OSTI]

    Boyer, Edmond

    L-223 INFLUENCE DES DIMENSIONS DE GRAINS SUR L'ANOMALIE DE LA RÉSISTIVITÉ DU NICKEL AUTOUR DU POINT. 2014 Les mesures de résistivité effectuées sur du nickel formé de cristaux très petits (15 Å, 25 Å) ont grain-sized nickel (15 Å, 25 Å). The critical exponent 03BD and the constant 03BE0 are computed. Results

  16. A finite element model of grain boundary sliding for nanostructured metals

    E-Print Network [OSTI]

    Jérusalem, Antoine, 1979-

    2004-01-01T23:59:59.000Z

    Nanocrystalline metals, i.e., polycrystalline metals with grain sizes in the nanometer range, have elicited significant interest recently due to their potential for achieving higher material strength in combination with ...

  17. Coarse Grained Quantum Dynamics

    E-Print Network [OSTI]

    Cesar Agon; Vijay Balasubramanian; Skyler Kasko; Albion Lawrence

    2014-12-09T23:59:59.000Z

    We consider coarse graining a quantum system divided between short distance and long distance degrees of freedom, which are coupled by the Hamiltonian. Observations using purely long distance observables can be described by the reduced density matrix that arises from tracing out the short-distance observables. The dynamics of this density matrix is that of an open quantum system, and is nonlocal in time, on the order of some short time scale. We describe these dynamics in a model system with a simple hierarchy of energy gaps $\\Delta E_{UV} > \\Delta E_{IR}$, in which the coupling between high-and low-energy degrees of freedom is treated to second order in perturbation theory. We then describe the equations of motion under suitable time averaging, reflecting the limited time resolution of actual experiments, and find an expansion of the master equation in powers of $\\Delta E_{IR}/\\Delta E_{UV}$, in which the failure of the system to be Hamiltonian or even Markovian appears at higher orders in this ratio. We compute the evolution of the density matrix in two specific examples -- coupled spins, and linearly coupled simple harmonic oscillators. Finally, we discuss the evolution of the density matrix using the path integral approach, computing the Feynman-Vernon influence functional for the IR degrees of freedom in perturbation theory, and argue that this influence functional is the correct analog of the Wilsonian effective action for this problem.

  18. On the AU Mic debris disk: density profiles, grain properties and dust dynamics

    E-Print Network [OSTI]

    J. C. Augereau; H. Beust

    2006-04-13T23:59:59.000Z

    We present the first comprehensive analysis of the AU Mic debris disk properties since the system was discovered by Kalas et al. (2004), and we explore whether the dynamical model, successful to reproduce the Beta Pic brightness profile could apply to AU Mic. We calculate the surface density profile of the AU Mic disk by performing the inversion of the near-IR and visible scattered light brightness profiles measured by Liu (2004a) and Krist et al. (2005), respectively. We discuss the grain properties by analysing the blue color of the disk in the visible (Krist et al. 2005) and by fitting the disk spectral energy distribution. We show that irrespective of the mean scattering asymmetry factor of the grains, most of the emission arises from an asymmetric, collisionally-dominated region that peaks close to the surface brightness break around 35 AU. The elementary scatterers at visible wavelengths are found to be sub-micronic, but the inferred size distribution underestimates the amount of large grains, resulting in too low sub-millimeter emissions compared to the observations. From our inversion procedure, we find that the V- to H-band scattering cross sections ratio increases outside 40 AU, in line with the observed color gradient of the disk. We show that a standard, solar-like stellar wind generates a pressure force onto the dust particles that behaves much like a radiation pressure force. With an assumed Mdot ~ 300 Mdot_sun, the wind pressure overcomes the radiation pressure and this effect is enhanced by the stellar flares. This explains the similarity between the Beta Pic and AU Mic brightness profiles. In both cases, the color gradient beyond 120 AU for Beta Pic and 35 AU for AU Mic, is believed to be a direct consequence of the dust dynamics.

  19. Infrared Emission from Interstellar Dust. I. Stochastic Heating of Small Grains

    E-Print Network [OSTI]

    B. T. Draine; Aigen Li

    2000-11-16T23:59:59.000Z

    We present a method for calculating the infrared emission from a population of dust grains heated by starlight, including very small grains for which stochastic heating by starlight photons results in high temperature transients. Because state-to-state transition rates are generally unavailable for complex molecules, we consider model PAH, graphitic, and silicate grains with realistic vibrational mode spectra and realistic radiative properties. The vibrational density of states is used in a statistical-mechanical description of the emission process. Unlike previous treatments, our approach fully incorporates multiphoton heating effects, important for large grains or strong radiation fields. We discuss how the "temperature" of the grain is related to its vibrational energy. By comparing with an "exact" statistical calculation of the emission process, we determine the conditions under which the "thermal" and the "continuous cooling" approximations can be used to calculate the emission spectrum. We present results for the infrared emission spectra of PAH grains of various sizes heated by starlight. We show how the relative strengths of the 6.2, 7.7, and 11.3um features depend on grain size, starlight spectrum and intensity, and grain charging conditions. We show results for grains in the "cold neutral medium", "warm ionized medium", and representative conditions in photodissociation regions. Our model results are compared to observed ratios of emission features for reflection nebulae and photodissociation regions, the Milky Way, normal spiral galaxies, and starburst galaxies.

  20. Farm Grain Drying and Storage 

    E-Print Network [OSTI]

    Anonymous

    CORN growing is, and is likely to remain, one of British agriculture's major enterprises. A very high proportion of the resulting harvest is now handled by combine harvesters, which bring with them problems of grain handling, ...

  1. RESEARCH ARTICLE The contribution of China's Grain to Green Program

    E-Print Network [OSTI]

    Xiao, Jingfeng

    RESEARCH ARTICLE The contribution of China's Grain to Green Program to carbon sequestration Dan Liu, the magnitude and distribution of carbon sequestration induced by GGP remain unknown. In this study, we in southern China. The economic benefits of carbon sequestration from the GGP were also estimated according

  2. Fabrication Characteristics of Large Grain DUPIC Fuel Using SIMFUEL

    SciTech Connect (OSTI)

    Park, Geun IL; Lee, Jung Won; Lee, Jae Won; Yang, Myung Seung; Song, Kee Chan [Korea Atomic Energy Research Institute, 150-1 Duckjin-Dong, 1045 Daedeokdaero, Yuseong, Daejeon Korea, 305-353 (Korea, Republic of)

    2007-07-01T23:59:59.000Z

    Fabrication characteristics to improve the density and grain size of DUPIC fuel with relation to its fuel performance were experimentally evaluated using SIMFUEL as a surrogate for an actual spent PWR fuel due to the high radioactivity of a spent fuel. Hence, SIMFUELs with a burn-up of 35,000 MWd/tU and 60,000 MWd/tU were used to investigate the influence of fission products contents as an impurity on the fuel powder properties and on the density and grain size of a simulated DUPIC pellet. In order to improve the densification and grain growth of the simulated DUPIC fuel, the effect of the addition of sintering aids was investigated. The specific surface area of the OREOX powders was increased with an increase of the impurities by the dissolved oxides in UO{sub 2} among the impurity groups. The specific surface area of the powders milled after the OXREOX treatment was slightly higher than the UO{sub 2} powder used for a nuclear power plant, thus resulting in sintered pellets with a higher than 95% T.D. (theoretical density). The grain size of the sintered pellets was significantly decreased with increasing amount of the metallic and oxide precipitates. However, on adding the sintering aids such as TiO{sub 2} and Nb{sub 2}O{sub 5}, the grain size of the sintering aids-doped pellets was greatly improved by up to around 3 times that of the raw pellets and their sintered density was also increased by up to 2%. (authors)

  3. 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)

    1990-01-01T23:59:59.000Z

    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. 6, 1184511875, 2006 A new SIze REsolved

    E-Print Network [OSTI]

    Boyer, Edmond

    the aerosol size distribution into sections and solves the GDE by splitting coagulation and condensation Interactive Discussion EGU that affect the aerosol size/composition distribution are therefore crucial. ThreeACPD 6, 11845­11875, 2006 A new SIze REsolved Aerosol Model E. Debry et al. Title Page Abstract

  5. adjustable pore size: Topics by E-print Network

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

    Science Websites Summary: -size distribution on pore shapedimensionality and sample temperature is predicted using a simple quantum mechanicalDetermination of pore-size...

  6. aerosol size classification: Topics by E-print Network

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

    2006 Aerosol size Physics Websites Summary: ACPD 6, 10493-10522, 2006 Aerosol size distribution source identification T. W. Chan and M Esc Printer-friendly Version...

  7. Are nanophase grain boundaries anomalous?

    SciTech Connect (OSTI)

    Stern, E.A.; Siegel, R.W.; Newville, M.; Sanders, P.G.; Haskel, D. [Department of Physics, FM-15, University of Washington, Seattle, Washington 98195 (United States)] [Department of Physics, FM-15, University of Washington, Seattle, Washington 98195 (United States); [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); [Materials Science and Engineering Department, Northwestern University, Evanston, Illinois 60208 (United States)

    1995-11-20T23:59:59.000Z

    The grain boundary regions of nanophase Cu metal are investigated using the x-ray absorption fine structure (XAFS) technique. Typical samples made by standard techniques need to be greatly thinned if measured in transmission in order to eliminate experimental artifacts which erroneously lower the apparent coordination number. To avoid this problem the samples were measured by the total electron yield technique. The results indicate a grain boundary structure which, on the average, is similar to that in conventional polycrystalline Cu, contrary to previous XAFS measurements made in transmission which indicated a lower coordination number. {copyright} {ital 1995} {ital The} {ital American} {ital Physical} {ital Society}.

  8. 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

    2014-08-01T23:59:59.000Z

    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 conversion facility.

  9. Effective grain surface area in the formation of molecular hydrogen in interstellar clouds

    E-Print Network [OSTI]

    Sandip Kumar Chakrabarti; Ankan Das; Kinsuk Acharyya; Sonali Chakrabarti

    2008-06-28T23:59:59.000Z

    In the interstellar clouds, molecular hydrogens are formed from atomic hydrogen on grain surfaces. An atomic hydrogen hops around till it finds another one with which it combines. This necessarily implies that the average recombination time, or equivalently, the effective grain surface area depends on the relative numbers of atomic hydrogen influx rate and the number of sites on the grain. Our aim is to discover this dependency. We perform a numerical simulation to study the recombination of hydrogen on grain surfaces in a variety of cloud conditions. We use a square lattice (with a periodic boundary condition) of various sizes on two types of grains, namely, amorphous carbon and olivine. We find that the steady state results of our simulation match very well with those obtained from a simpler analytical consideration provided the `effective' grain surface area is written as $\\sim S^{\\alpha}$, where, $S$ is the actual physical grain area and $\\alpha$ is a function of the flux of atomic hydrogen which is determined from our simulation. We carry out the simulation for various astrophysically relevant accretion rates. For high accretion rates, small grains tend to become partly saturated with $H$ and $H_2$ and the subsequent accretion will be partly inhibited. For very low accretion rates, the number of sites to be swept before a molecular hydrogen can form is too large compared to the actual number of sites on the grain, implying that $\\alpha$ is greater than unity.

  10. LI,HOSPEDALES,SONG,GONG: FINE-GRAINED SKETCH-BASED IMAGE RETRIEVAL 1 Fine-Grained Sketch-Based Image Retrieval

    E-Print Network [OSTI]

    Gong, Shaogang

    LI,HOSPEDALES,SONG,GONG: FINE-GRAINED SKETCH-BASED IMAGE RETRIEVAL 1 Fine-Grained Sketch.hospedales@qmul.ac.uk Yi-Zhe Song yizhe.song@qmul.ac.uk Shaogang Gong s.gong@qmul.ac.uk Queen Mary University of London. It may be distributed unchanged freely in print or electronic forms. #12;2 LI,HOSPEDALES,SONG,GONG: FINE

  11. Information-theoretic significance of the Wigner distribution

    E-Print Network [OSTI]

    Frieden, B R; Soffer, Bernard H

    2006-01-01T23:59:59.000Z

    cance of the Wigner distribution B. Roy Frieden College ofA coarse-grained Wigner distribution p W ?x , ? ? obeyingon the Wigner distribution. A. Positivity property of coarse

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

    SciTech Connect (OSTI)

    Liu Yuncai [Shoudu Iron and Steel Co., Beijing (China)

    1996-12-31T23:59:59.000Z

    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.

  13. 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

    2015-03-15T23:59:59.000Z

    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

  14. Petrographic characterization of Kentucky coals. Final report. Part V. Pyrite size/form/microlithotype distribution in western Kentucky prepared coals and in channel samples from western Kentucky and western Pennsylvania

    SciTech Connect (OSTI)

    Frankle, K.A.; Hower, J.C.

    1983-01-01T23:59:59.000Z

    Pyrite and marcasite distribution has been characterized in several western Kentucky coals, western Pennsylvania coals, and coals from western Kentucky preparation plants using three parameters of size, morphology, and microlithotype association. A classification system was developed to provide a consistent method for recording different pyrite/marcasite types. Sulfides were microscopically measured and placed in one of six size divisions (<5, 5 to 10, 10 to 40, 40 to 75, 75 to 100, or >150..mu..m) rather than absolute size. Five categories (euhedral, framboidal, dendritic, massive, or cleat) describe pyrite/marcasite morphology. The third parameter identifies the microlithotype (vitrite, clarite, inertite, liptite, durite, vitrinertite, trimacerite, or carbominerite) in which the pyrite occurs (not including the measured sulfide). Carbominerite is a mineral/organic association dominated by mineral matter. The percentage of each variable represents the total number of counts per sample and not the volume of pyrite. Throughout the studies, both sulfides are collectively referred to as pyrite unless otherwise specified. This paper describes the different studies which were undertaken to test the usefulness of this pyrite classification system. Systematic trends in pyrite variability were determined for the Springfield coal and Herrin of western Kentucky. Pyrite characterization of the Lower Kittanning coal from western Pennsylvania shows that certain pyrite morphologies can be an expression of the environments deposition of coal bodies. Studies of western Kentucky prepared coals demonstrate that pyrite characterization apparently can provide a method for predicting pyrite behavior and the extent of pyrite removal for specific coals. 77 references, 15 figures, 19 tables.

  15. Port of Houston Intermodal Grain Transfer System and Market Area, 1976 - 1977.

    E-Print Network [OSTI]

    Fuller, Stephen W.; Paggi, Mechel S.

    1978-01-01T23:59:59.000Z

    to 41 feet. This implies that these vessels grain at the Port of Houston. Practical experience has were not able to be fully loaded. Bulk carriers and tank- shown that up to a point, the larger the ship employed in the transport of bulk cargoes... AND SHIPMENT PATTERNS ............... 12 MODES OF TRANSPORTATION ON GRAIN AND SOYBEAN RECEIPTS ..................................... 14 FOREIGN DESTl NATIONS ..................................... 14 CARGO SIZES BY DESTINATION AND COMMODITY .......... 14...

  16. Commercial Storage and Handling of Sorghum Grain.

    E-Print Network [OSTI]

    Brown, Charles W.; Moore, Clarence A.

    1963-01-01T23:59:59.000Z

    Summary Three areas that provide a cross section of physical and economic conditions under which sorghum grain is produced, handled and stored were selected for study of storage and handling facilities and practices by commercial grain storage...-60. Grain stocks in storage increased even more rapidly. Storage space in 1955 was 71 percent occupied on January 1, whereas the much greater space in 1960 was 82 percent occupied. Grain sorghum increased from less than half to almost three...

  17. Grain alignment in starless cores

    SciTech Connect (OSTI)

    Jones, T. J.; Bagley, M. [Minnesota Institute for Astrophysics, University of Minnesota, Minneapolis, MN 55455 (United States); Krejny, M. [Cree Inc., 4600 Silicon Dr., Durham, NC (United States); Andersson, B.-G. [SOFIA Science Center, USRA, Moffett Field, CA (United States); Bastien, P., E-mail: tjj@astro.umn.edu [Centre de recherche en astrophysique du Québec and Départment de Physique, Université de Montréal, Montréal (Canada)

    2015-01-01T23:59:59.000Z

    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}/?{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 ? 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.

  18. Images of Vega Dust Ring at 350 and 450 microns: New Clues to the Trapping of Multiple-Sized Dust Particles in Planetary Resonances

    E-Print Network [OSTI]

    K. A. Marsh; C. D. Dowell; T. Velusamy; K. Grogan; C. A. Beichman

    2006-06-14T23:59:59.000Z

    We have used the SHARC II camera at Caltech Submillimeter Observatory to make 350 and 450 micron images of the Vega dust disk at spatial resolutions (FWHM) of 9.7" and 11.1", respectively. The images show a ring-like morphology (radius \\~ 100 AU) with inhomogeneous structure that is qualitatively different from that previously reported at 850 microns and longer wavelengths. We attribute the 350/450 micron emission to a grain population whose characteristic size (~ 1 mm) is intermediate between that of the cm-sized grains responsible for emission longward of 850 microns and the much smaller grains (< 18 microns) in the extensive halo, visible at 70 microns, discussed by Su et al. (2005). We have combined our submillimeter images with Spitzer data at 70 microns to produce 2-d maps of line-of-sight optical depth (relative column density). These "tau maps" suggest that the mm-sized grains are located preferentially in three symmetrically-located concentrations. If so, then this structure could be understood in terms of the Wyatt (2003) model in which planetesimals are trapped in the mean motion resonances of a Neptune-mass planet at 65 AU, provided allowance is made for the spatial distribution of dust grains to differ from that of the parent planetesimals. The peaks of the tau maps are, in fact, located near the expected positions corresponding to the 4:3 resonance. If this identification is confirmed by future observations, it would resolve an ambiguity with regard to the location of the planet.

  19. C, N, AND O ISOTOPIC HETEROGENEITIES IN LOW-DENSITY SUPERNOVA GRAPHITE GRAINS FROM ORGUEIL

    SciTech Connect (OSTI)

    Groopman, Evan; Bernatowicz, Thomas; Zinner, Ernst, E-mail: eegroopm@physics.wustl.edu [Laboratory for Space Sciences, Washington University, One Brookings Drive, Campus Box 1105, Saint Louis, MO 63130 (United States)

    2012-07-20T23:59:59.000Z

    We report on the results of NanoSIMS isotope imaging of low-density supernova graphite grains from the Orgueil meteorite. 70 nm thick microtomed sections of three supernova graphite grains were deposited on Si wafers and isotopically imaged in the NanoSIMS. These sections contain hotspots of excesses in {sup 18}O and {sup 15}N, which are spatially well correlated, and are likely carried by internal TiC subgrains. These hotspots are considerably more enriched in {sup 18}O and {sup 15}N than the host graphite grain. Correlations between {sup 18}O and {sup 15}N excesses indicate that the grains incorporated material from the He/C supernova zone. Isotope images of the surfaces of some grains show heterogeneities in their N and O isotope compositions, with extreme excesses in {sup 15}N and {sup 18}O. In the microtome sections, we also observe two types of heterogeneities in the grains' C isotopic compositions: smooth, radial gradients in {sup 12}C/{sup 13}C, with this ratio trending toward solar with increasing radius; and highly anomalous pockets up to 2 {mu}m in size with {sup 12}C/{sup 13}C >> solar that are located near the centers of the grain sections. Partial isotopic equilibration does not likely explain the C isotopic heterogeneities. These grains and their constituent parts probably formed in a stellar environment with changing isotopic composition.

  20. ARM - Measurement - Hydrometeor size

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP : XDC documentationBarrow,ice particleSize Distribution

  1. 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

    2012-09-17T23:59:59.000Z

    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 by the flaw density and size distribution values used in the PTS technical basis. Under a contract with the NRC, Pacific Northwest National Laboratory (PNNL) has been working on a program to assess the ability of current inservice inspection (ISI)-ultrasonic testing (UT) techniques, as qualified through ASME Code, Appendix VIII, Supplements 4 and 6, to detect small fabrication or inservice-induced flaws located in RPV welds and adjacent base materials. As part of this effort, the investigators have pursued an evaluation, based on the available information, of the capability of UT to provide flaw density/distribution inputs for making RPV weld assessments in accordance with §50.61a. This paper presents the results of an evaluation of data from the 1993 Browns Ferry Nuclear Plant, Unit 3, Spirit of Appendix VIII reactor vessel examination, a comparison of the flaw density/distribution from this data with the distribution in §50.61a, possible reasons for differences, and plans and recommendations for further work in this area.

  2. Cluster size distribution for free molecular agglomeration

    SciTech Connect (OSTI)

    Mulholland, G.W.; Samson, R.J.; Mountain, R.D.; Ernst, M.H.

    1988-01-01T23:59:59.000Z

    Dobbins and Megaridis have observed soot agglomerates in a diffusion flame via thermophoretic sampling. The agglomerates are made up of spherules with a typical diameter of about 30 nm. A characteristic of the agglomerate is the relatively low density of the structure with much open space. This study is concerned with modeling the agglomeration growth process.

  3. Particle Size Distribution of Gypseous Samples

    E-Print Network [OSTI]

    Arnett, Morgan P.

    2010-01-16T23:59:59.000Z

    to conditions in the field. In order to understand the true characterization of the soil and the gypsum particles, the entire soil sample should be analyzed. Four different approaches to the BaCl2 method presented in the literature (Hesse, 1976, Matar...

  4. ARM - Measurement - Cloud particle size distribution

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP : XDC documentationBarrow,ice particle ARM Data Discoverysize

  5. Characterizing Uncertainties in Ice Particle Size Distributions

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office511041clothAdvanced Materials Advanced. C o w l i t z C

  6. 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. [NASA-Marshall Space Flight Center, Huntsville, AL 35812 (United States); Tankosic, D., E-mail: Mian.M.Abbas@nasa.go [USRA/NASA-Marshall Space Flight Center, Huntsville, AL 35805 (United States)

    2010-08-01T23:59:59.000Z

    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.

  7. Atom probe study of grain boundary segregation in technically pure molybdenum

    SciTech Connect (OSTI)

    Babinsky, K., E-mail: katharina.babinsky@stud.unileoben.ac.at [Montanuniversität Leoben, Department of Physical Metallurgy and Materials Testing, Franz-Josef Straße 18, 8700 Leoben (Austria); Weidow, J., E-mail: jonathan.weidow@chalmers.se [Chalmers University of Technology, Department of Applied Physics, 412 96 Gothenburg (Sweden); Knabl, W., E-mail: wolfram.knabl@plansee.com [PLANSEE SE, Metallwerk-Plansee-Straße 71, 6600 Reutte (Austria); Lorich, A., E-mail: alexander.lorich@plansee.com [PLANSEE SE, Metallwerk-Plansee-Straße 71, 6600 Reutte (Austria); Leitner, H., E-mail: harald.leitner@bohler-edelstahl.at [Montanuniversität Leoben, Department of Physical Metallurgy and Materials Testing, Franz-Josef Straße 18, 8700 Leoben (Austria); Primig, S., E-mail: sophie.primig@unileoben.ac.at [Montanuniversität Leoben, Department of Physical Metallurgy and Materials Testing, Franz-Josef Straße 18, 8700 Leoben (Austria)

    2014-01-15T23:59:59.000Z

    Molybdenum, a metal with excellent physical, chemical and high-temperature properties, is an interesting material for applications in lighting-technology, high performance electronics, high temperature furnace construction and coating technology. However, its applicability as a structural material is limited because of the poor oxidation resistance at high temperatures and a brittle-to-ductile transition around room temperature, which is influenced by the grain size and the content of interstitial impurities at the grain boundaries. Due to the progress of the powder metallurgical production during the last decades, the amount of impurities in the current quality of molybdenum has become so small that surface sensitive techniques are not applicable anymore. Therefore, the atom probe, which allows the detection of small amounts of impurities as well as their location, seems to be a more suitable technique. However, a site-specific specimen preparation procedure for grain boundaries in refractory metals with a dual focused ion beam/scanning electron microscope is still required. The present investigation describes the development and successful application of such a site-specific preparation technique for grain boundaries in molybdenum, which is significantly improved by a combination with transmission electron microscopy. This complimentary technique helps to improve the visibility of grain boundaries during the last preparation steps and to evidence the presence of grain and subgrain boundaries without segregants in atom probe specimens. Furthermore, in industrially processed and recrystallized molybdenum sheets grain boundary segregation of oxygen, nitrogen and potassium is successfully detected close to segregated regions which are believed to be former sinter pores. - Highlights: • First study of grain boundary segregation in molybdenum by atom probe • Site-specific preparation technique by FIB and TEM successfully developed • Grain boundary segregation of oxygen, nitrogen and potassium found • Segregation in former sinter-pores detected • Presence of grain boundaries without segregation evidenced.

  8. Aerosol mobility size spectrometer

    DOE Patents [OSTI]

    Wang, Jian (Port Jefferson, NY); Kulkarni, Pramod (Port Jefferson Station, NY)

    2007-11-20T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Koski, Kristie Jo

    2008-12-31T23:59:59.000Z

    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.

  10. Particle in cell calculation of plasma force on a small grain in a non-uniform collisional sheath

    E-Print Network [OSTI]

    Hutchinson, Ian H.

    The plasma force on grains of specified charge and height in a collisional DC plasma sheath is calculated using the multidimensional particle in cell code COPTIC. The background ion velocity distribution functions for the ...

  11. 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.

    2012-09-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Sirono, Sin-iti [Earth and Environmental Sciences, Graduate School of Environmental Studies, Nagoya University, Nagoya 464-8601 (Japan)] [Earth and Environmental Sciences, Graduate School of Environmental Studies, Nagoya University, Nagoya 464-8601 (Japan)

    2013-03-01T23:59:59.000Z

    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.

  13. 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...

  14. Edison Job Size Charts

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

    Job Size Charts Edison Job Size Charts Fraction of Hours Used per Job Size This chart shows the fraction of hours used on Edison in each of 5 job-core-size bins. 2015 Usage by Job...

  15. Can amphiphile architecture directly control vesicle size?

    E-Print Network [OSTI]

    M. J. Greenall; C. M. Marques

    2013-01-28T23:59:59.000Z

    Bilayer membranes self-assembled from simple amphiphiles in solution always have a planar ground-state shape. This is a consequence of several internal relaxation mechanisms of the membrane and prevents the straightforward control of vesicle size. Here, we show that this principle can be circumvented and that direct size control by molecular design is a realistic possibility. Using coarse-grained calculations, we design tetrablock copolymers that form membranes with a preferred curvature, and demonstrate how to form low-polydispersity vesicles while suppressing micellization.

  16. Ultrafine-grained titanium for medical implants

    DOE Patents [OSTI]

    Zhu, Yuntian T. (Los Alamos, NM); Lowe, Terry C. (Santa Fe, NM); Valiev, Ruslan Z. (Ufa, RU); Stolyarov, Vladimir V. (Ufa, RU); Latysh, Vladimir V. (Ufa, RU); Raab, Georgy J. (Ufa, RU)

    2002-01-01T23:59:59.000Z

    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.

  17. 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.

    2009-01-01T23:59:59.000Z

    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 analyticalmore »extrapolation to the fully crystallized state. Electron diffraction reveals a predominance of the anatase crystallographic phase.« less

  18. The Signature of Primordial Grain Growth in the Polarized Light of the AU Mic Debris Disk

    E-Print Network [OSTI]

    James R. Graham; Paul G. Kalas; Brenda C. Matthews

    2006-09-12T23:59:59.000Z

    We have used the Hubble Space Telescope/ACS coronagraph to make polarization maps of the AU Mic debris disk. The fractional linear polarization rises monotonically from about 0.05 to 0.4 between 20 and 80 AU. The polarization is perpendicular to the disk, indicating that the scattered light originates from micron sized grains in an optically thin disk. Disk models, which simultaneously fit the surface brightness and polarization, show that the inner disk (< 40-50 AU) is depleted of micron-sized dust by a factor of more than 300, which means that the disk is collision dominated. The grains have high maximum linear polarization and strong forward scattering. Spherical grains composed of conventional materials cannot reproduce these optical properties. A Mie/Maxwell-Garnett analysis implicates highly porous (91-94%) particles. In the inner Solar System, porous particles form in cometary dust, where the sublimation of ices leaves a "bird's nest" of refractory organic and silicate material. In AU Mic, the grain porosity may be primordial, because the dust "birth ring" lies beyond the ice sublimation point. The observed porosities span the range of values implied by laboratory studies of particle coagulation by ballistic cluster-cluster aggregation. To avoid compactification, the upper size limit for the parent bodies is in the decimeter range, in agreement with theoretical predictions based on collisional lifetime arguments. Consequently, AU Mic may exhibit the signature of the primordial agglomeration process whereby interstellar grains first assembled to form macroscopic objects.

  19. Deformation-Twin-Induced Grain Boundary Failure

    SciTech Connect (OSTI)

    Yongfeng Zhang; Paul C. MIllett; Michael Tonks; Bulent Biner

    2012-01-01T23:59:59.000Z

    This work presents a mechanism of deformation-twin-induced grain boundary failure, and demonstrates the mechanism using molecular dynamics simulations. Deformation twinning is observed as the dominant mechanism during tensile deformation of columnar nanocrystalline body-centered cubic Mo. As a twin approaches a grain boundary, local stress concentration develops due to the incompatible plastic deformations in the two neighboring grains. The magnitude of the stress concentration increases as the twin widens, leading to grain boundary cracking by nucleation and coalescence of microcracks/voids.

  20. C2D Spitzer-IRS spectra of disks around T Tauri stars: I. Silicate emission and grain growth

    E-Print Network [OSTI]

    J. E. Kessler-Silacci; J. -C. Augereau; C. P. Dullemond; V. Geers; F. Lahuis; N. J. Evans II; E. F. van Dishoeck; G. A. Blake; A. C. A. Boogert; J. Brown; J. K. Jorgensen; C. Knez; K. M. Pontoppidan

    2005-11-02T23:59:59.000Z

    Infrared ~5--35 um spectra for 40 solar-mass T Tauri stars and 7 intermediate-mass Herbig Ae stars with circumstellar disks were obtained using the Spitzer Space Telescope as part of the c2d IRS survey. This work complements prior spectroscopic studies of silicate infrared emission from disks, which were focused on intermediate-mass stars, with observations of solar-mass stars limited primarily to the 10 um region. The observed 10 and 20 um silicate feature strengths/shapes are consistent with source-to-source variations in grain size. A large fraction of the features are weak and flat, consistent with um-sized grains indicating fast grain growth (from 0.1--1.0 um in radius). In addition, approximately half of the T Tauri star spectra show crystalline silicate features near 28 and 33 um indicating significant processing when compared to interstellar grains. A few sources show large 10-to-20 um ratios and require even larger grains emitting at 20 um than at 10 um. This size difference may arise from the difference in the depth into the disk probed by the two silicate emission bands in disks where dust settling has occurred. The 10 um feature strength vs. shape trend is not correlated with age or Halpha equivalent width, suggesting that some amount of turbulent mixing and regeneration of small grains is occurring. The strength vs. shape trend is related to spectral type, however, with M stars showing significantly flatter 10 um features (larger grain sizes) than A/B stars. The connection between spectral type and grain size is interpreted in terms of the variation in the silicate emission radius as a function of stellar luminosity, but could also be indicative of other spectral-type dependent factors (e.g, X-rays, UV radiation, stellar/disk winds, etc.).

  1. Coarse-grained Classification of Web Sites by Their Structural Properties

    E-Print Network [OSTI]

    Lindemann, Christoph

    Coarse-grained Classification of Web Sites by Their Structural Properties Christoph Lindemann properties which reflect the functionality of a Web site. These structural properties consider the size, the organization, the composition of URLs, and the link structure of Web sites. Opposed to previous work, we

  2. Grain Sorghums Versus Corn for Fattening Lambs

    E-Print Network [OSTI]

    Jones, J. M. (John McKinley); Brewer, Roy A.

    1922-01-01T23:59:59.000Z

    total gain, lbs. ........... Average daily gain, lbs. ........... Average daily ration: 1. Grain, lbs.. ................. 2. Cottonseed meal, Ibs.. ....... 3. Alfalfa hay, lbs.. ............ Total feed consumed per lamb: 1. Grain, Ibs..... ................. 2. Cottonseed meal, Ibs. ........ 3. Alfalfa hay, lbs.. .... .; ...... Concentrates per 100 lbs. gain, lbs.. Hay per 100 lbs. gain. lbs. : ....... Cost of feed per 100 lbs. galn. ..... Averagefeedcostperlamb ........ Initial cost per lamb...

  3. Floating potential of large dust grains with electron emission

    SciTech Connect (OSTI)

    Bacharis, M., E-mail: minas.bacharis03@imperial.ac.uk [Blackett Laboratory, Imperial College, Prince Consort Road, London SW7 2BW (United Kingdom)

    2014-07-15T23:59:59.000Z

    Electron emission from the surface of solid particles plays an important role in many dusty plasma phenomena and applications. Examples of such cases include fusion plasmas and dusty plasma systems in our solar system. Electron emission complicates the physics of the plasma-dust interaction. One of the most important aspects of the physics of the dust plasma interaction is the calculation of the particle's floating potential. This is the potential a dust particle acquires when it is in contact with a plasma and it plays a very important role for determining its dynamical behaviour. The orbital motion limited (OML) approach is used in most cases in the literature to model the dust charging physics. However, this approach has severe limitations when the size of the particles is larger than the electron Debye length ?{sub De}. Addressing this shortcoming for cases without electron emission, a modified version of OML (MOML) was developed for modelling the charging physics of dust grains larger than the electron Debye length. In this work, we will focus on extending MOML in cases where the particles emit electrons. Furthermore, a general method for calculating the floating potential of dust particles with electron emission will be presented for a range of grain sizes.

  4. 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)

    2014-11-01T23:59:59.000Z

    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 Fuchs–Sondheimer surface scattering model and Mayadas–Shatzkes 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.

  5. Changing Supply of Grains in Texas.

    E-Print Network [OSTI]

    Moore, Clarence A.; Whitney, Howard S.

    1959-01-01T23:59:59.000Z

    in the 1940's. It declined in relative importance, while rice in- creased, in the food grain group in the 1950's. Grain sorghum increased from 21 percent of total feed grain production in 1935-39 to 72 percent in 1955-58, while corn decreased from 52... to 14 per- cent. Texas usually grows more than one-fourth of the total U. S. production of rice. Production in- creased from slightly less than 4 million bags (100 pounds) in 1935 to over 17 million in 1954. It varied from 11 to 15 million bags...

  6. Band-Gap Engineering of Carbon Nanotubes with Grain Boundaries...

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

    Band-Gap Engineering of Carbon Nanotubes with Grain Boundaries. Band-Gap Engineering of Carbon Nanotubes with Grain Boundaries. Abstract: Structure and electronic properties of...

  7. Effects of Transition Metals on the Grain Boundary Cohesion in...

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

    Transition Metals on the Grain Boundary Cohesion in Tungsten. Effects of Transition Metals on the Grain Boundary Cohesion in Tungsten. Abstract: We report on the effects of...

  8. Dust filtration at gap edges: Implications for the spectral energy distributions of discs with embedded planets

    E-Print Network [OSTI]

    W. K. M. Rice; Philip J. Armitage; Kenneth Wood; Giuseppe Lodato

    2006-09-29T23:59:59.000Z

    The spectral energy distributions (SEDs) of some T Tauri stars display a deficit of near-IR flux that could be a consequence of an embedded Jupiter-mass planet partially clearing an inner hole in the circumstellar disc. Here, we use two-dimensional numerical simulations of the planet-disc interaction, in concert with simple models for the dust dynamics, to quantify how a planet influences the dust at different radii within the disc. We show that pressure gradients at the outer edge of the gap cleared by the planet act as a filter - letting particles smaller than a critical size through to the inner disc while holding back larger particles in the outer disc. The critical particle size depends upon the disc properties, but is typically of the order of 10 microns. This filtration process will lead to discontinuous grain populations across the planet's orbital radius, with small grains in the inner disc and an outer population of larger grains. We show that this type of dust population is qualitatively consistent with SED modelling of systems that have optically thin inner holes in their circumstellar discs. This process can also produce a very large gas-to-dust ratio in the inner disc, potentially explaining those systems with optically thin inner cavities that still have relatively high accretion rates.

  9. 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

    2014-10-01T23:59:59.000Z

    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.

  10. 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.

    2015-03-13T23:59:59.000Z

    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

  11. Topological analysis of the grain boundary space

    E-Print Network [OSTI]

    Patala, Srikanth

    2011-01-01T23:59:59.000Z

    Grain boundaries and their networks have a profound influence on the functional and structural properties of every class of polycrystalline materials and play a critical role in structural evolution and phase transformations. ...

  12. Electric Dipole Radiation from Spinning Dust Grains

    E-Print Network [OSTI]

    B. T. Draine; A. Lazarian

    1998-02-18T23:59:59.000Z

    We discuss the rotational excitation of small interstellar grains and the resulting electric dipole radiation from spinning dust. Attention is given to excitation and damping of rotation by: collisions with neutrals; collisions with ions; plasma drag; emission of infrared radiation; emission of microwave radiation; photoelectric emission; and formation of H_2 on the grain surface. We introduce dimensionless functions F and G which allow direct comparison of the contributions of different mechanisms to rotational drag and excitation. Emissivities are estimated for dust in different phases of the interstellar medium, including diffuse HI, warm HI, low-density photoionized gas, and cold molecular gas. Spinning dust grains can explain much, and perhaps all, of the 14-50 GHz background component recently observed in CBR studies. It should be possible to detect rotational emission from small grains by ground-based observations of molecular clouds.

  13. The Influence of Grain Boundary Type upon Damage Evolution at Grain Boundary Interfaces

    SciTech Connect (OSTI)

    Perez-Bergquist, Alejandro G [Los Alamos National Laboratory; Brandl, Christian [Los Alamos National Laboratory; Escobedo, Juan P [Los Alamos National Laboratory; Trujillo, Carl P [Los Alamos National Laboratory; Cerreta, Ellen K [Los Alamos National Laboratory; Gray III, George T [Los Alamos National Laboratory; Germann, Timothy C [Los Alamos National Laboratory

    2012-07-09T23:59:59.000Z

    In a prior work, it was found that grain boundary structure strongly influences damage evolution at grain boundaries in copper samples subjected to either shock compression or incipient spall. Here, several grain boundaries with different grain boundary structures, including a {Sigma}3 (10-1) boundary, are interrogated via conventional transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM) to investigate the effects of atomic-scale structural differences on grain boundary strength and mobility. Boundaries are studied both before and after shock compression at a peak shock stress of 10 GPa. Results of the TEM and HRTEM work are used in conjunction with MD modeling to propose a model for shock-induced damage evolution at grain boundary interfaces that is dependent upon coincidence.

  14. Greenbug-resistance Studies with Small Grains.

    E-Print Network [OSTI]

    Chada, H. L.; Atkins, I. M.; Gardenhire, J. H.; Weibl, D. E.

    1961-01-01T23:59:59.000Z

    insects. Such varieties may not be immune from attack, but insect populations increase on them more slowly; therefore, they are more readily controlled with chemicals when necessary. Greenbug-resistance studies were initiated at Substation No. 6.... Gardenhire and D. E. Weibel* HE GREENBUG (Toxoptera (Rond.)), among several aphids that attack small grains, is one of the most damaging insects of small- grain crops in the United States. Fifteen serious outbreaks have oc- curred since 1882, 10...

  15. atmospheric aerosol size: Topics by E-print Network

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

    Size Distribution Physics (arXiv) Summary: Atmospheric flows exhibit selfsimilar fractal spacetime fluctuations manifested as the fractal geometry to global cloud cover...

  16. algorithm population sizing: Topics by E-print Network

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

    CiteSeer Summary: Deciding the appropriate population size and number of islands for distributed island-model genetic algorithms is often critical to the algorithms success. This...

  17. alter perceived size: Topics by E-print Network

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

    of two colliding dust aggregates into a coagulation model that computes the dust size distribution with time. All collisional outcomes -- sticking, fragmentation...

  18. The effects of grain moisture content and grain temperature on the penetration of hydrogen cyanide

    E-Print Network [OSTI]

    Kunz, Sidney E

    1962-01-01T23:59:59.000Z

    THE EFFECTS QF CRAIN MOISTURE CONTENT AND GRAIN TEMiPERATURE ON THE &NETRATION OF HYDROGEN CYANIDE A Thesis SIDNEY EDMUND KUNZ Submitted to the Graduate School of ths Agricultural and Mechanical College of Texas in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE (Mionth) 1262 (Year) Mayor Subject ghtdlggllQJLK THE EFFECTS OF GRAIN MOISTURE CONTENT JBD GRAIN TEMPERATURE ON THE PENETRATION OF HYDROGEN CYANIDE A Thesis SIDNEY EDNUND KUNZ Approved as to style...

  19. On the Synchronization of Networks with Prescribed Degree Distributions

    E-Print Network [OSTI]

    Jost, Jürgen

    On the Synchronization of Networks with Prescribed Degree Distributions Fatihcan M. Atay T for building non-synchronizing networks having a prescribed degree distribution. Index Terms distribution, which converges to a Poisson distribution for large network sizes. The degree distribution

  20. Micro-PIXE measurement of Ni distribution over supported nickel oxide catalyst

    SciTech Connect (OSTI)

    Ahmed, M.; Rahman, A.; Nickel, J. [King Fahd Univ., Dhahran (Saudi Arabia)] [and others

    1994-12-31T23:59:59.000Z

    Supported nickel oxide catalysts have a wide range of applications in petrochemical industry. This work reports the results of a micro-PIXE measurement of Ni distribution in a supported nickel oxide catalyst over individual silica base particles, 60-200 {mu}m in size. These catalysts were synthesized with 1% and 5% then calcined at 400 {degrees}C. A 2.5 MeV proton microbeam was used to scan the samples of individual grains. Two dimensional distribution maps of Ni and Si have been measured. This paper discusses the important effects of the process of calcination on the distribution of Ni. The effects of different nickel loading and other synthesis conditions will also be discussed.

  1. Short-time beta grain growth kinetics for a conventional titanium alloy

    SciTech Connect (OSTI)

    Semiatin, S.L. [WL/MLLN, Wright-Patterson AFB, OH (United States). Materials Directorate] [WL/MLLN, Wright-Patterson AFB, OH (United States). Materials Directorate; Soper, J.C. [Wright State Univ., Dayton, OH (United States)] [Wright State Univ., Dayton, OH (United States); Sukonnik, I.M. [Texas Instruments, Attleboro, MA (United States)] [Texas Instruments, Attleboro, MA (United States)

    1996-05-01T23:59:59.000Z

    The kinetics of beta grain growth during short-time, supertransus heat treatment of Ti-5Al-4V were determined using a salt-pot technique. The finite-time, subtransus temperature transient during salt-pot heating was quantified through measurements of the heat transfer coefficient characterizing conduction across the salt-titanium interface and a simple heat conduction analysis which incorporated this heat transfer coefficient. Grain size versus time data adjusted to account for the subtransus temperature transient were successfully fit to the parabolic grain growth law d{sup n} {minus} d{sub 0}{sup n} = kt exp({minus}Q/RT) using an exponent n equal to 2.0. Comparison of the present results to rapid, continuous heat treatment data in the literature for a similar titanium alloy revealed a number of semi-quantitative similarities.

  2. Usage by Job Size

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

    Usage by Job Size Table Usage by Job Size Table page loading animation Usage Query Interface System All Hopper Edison Carver Planck Matgen Franklin Hopper 1 Magellan Dirac Bassi...

  3. Extractability Profiling and Antioxidant Activity of Flavonoids in Sorghum Grain and Non-grain Materials

    E-Print Network [OSTI]

    Njongmeta, Nenge Lynda A.

    2010-07-14T23:59:59.000Z

    acids and enzymes on extractability of phenols. Flavonoid profiles of grains and non-grain tissues were determined and characterized using HPLC-PDA and HPLC-ESI-MSn. The presence of a pigmented testa and spreader genes (B1B2S) is a predictor...

  4. PROPERTIES OF NEWLY FORMED DUST GRAINS IN THE LUMINOUS TYPE IIn SUPERNOVA 2010jl

    SciTech Connect (OSTI)

    Maeda, K.; Nozawa, T.; Folatelli, G.; Moriya, T. J.; Nomoto, K.; Bersten, M.; Quimby, R. [Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Sahu, D. K.; Anupama, G. C. [Indian Institute of Astrophysics, Koramangala, Bangalore 560 034 (India); Minowa, Y.; Pyo, T.-S. [Subaru Telescope, National Astronomical Observatory of Japan, 650 North A'ohoku Place, Hilo, HI 96720 (United States); Motohara, K.; Kitagawa, Y. [Institute of Astronomy, University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan); Ueno, I.; Kawabata, K. S.; Yamanaka, M. [Hiroshima Astrophysical Science Center, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Kozasa, T. [Department of Cosmosciences, Graduate School of Science, Hokkaido University, Sapporo 060-0810 (Japan); Iye, M., E-mail: keiichi.maeda@ipmu.jp [National Astronomical Observatory, Mitaka, Tokyo (Japan)

    2013-10-10T23:59:59.000Z

    Supernovae (SNe) have been proposed to be the main production sites of dust grains in the universe. However, our knowledge of their importance to dust production is limited by observationally poor constraints on the nature and amount of dust particles produced by individual SNe. In this paper, we present a spectrum covering optical through near-Infrared (NIR) light of the luminous Type IIn supernova 2010jl around one and a half years after the explosion. This unique data set reveals multiple signatures of newly formed dust particles. The NIR portion of the spectrum provides a rare example where thermal emission from newly formed hot dust grains is clearly detected. We determine the main population of the dust species to be carbon grains at a temperature of ?1350-1450 K at this epoch. The mass of the dust grains is derived to be ?(7.5-8.5) × 10{sup –4} M{sub ?}. Hydrogen emission lines show wavelength-dependent absorption, which provides a good estimate of the typical size of the newly formed dust grains (?< 0.1 ?m, and most likely ?< 0.01 ?m). We believe the dust grains were formed in a dense cooling shell as a result of a strong SN-circumstellar media (CSM) interaction. The dust grains occupy ?10% of the emitting volume, suggesting an inhomogeneous, clumpy structure. The average CSM density must be ?> 3 × 10{sup 7} cm{sup –3}, corresponding to a mass loss rate of ?> 0.02 M{sub ?} yr{sup –1} (for a mass loss wind velocity of ?100 km s{sup –1}). This strongly supports a scenario in which SN 2010jl and probably other luminous SNe IIn are powered by strong interactions within very dense CSM, perhaps created by Luminous-Blue-Variable-like eruptions within the last century before the explosion.

  5. Development of large Grain/Single Crystal Niobium Cavity Technology at Jefferson Lab

    SciTech Connect (OSTI)

    Peter Kneisel; J. Sekutowicz; T. Carneiro; G. Ciovati

    2006-10-31T23:59:59.000Z

    Approximately two years ago we started to develop high performance niobium accelerating cavities based on large grain or single crystal high purity niobium. We have fabricated and tested 15 single cell cavities of various shapes and frequencies between 1300 MHz and 2300 MHz using material from a total of 9 different very large grain niobium ingots from four niobium suppliers. The materials differed not only in grain sizes, but also in RRR ? value and in the amount of Ta contained in the material. In one ingot supplied by CBMM the central grain exceeded 7 inches in diameter and this was used to fabricate two 2.2 GHz cavities. A single crystal 1300 MHz mono-cell cavity was also produced at DESY by rolling out a single crystal to the size required for this cavity. It was sent to Jlab for surface treatment and testing. In addition, we have fabricated three 7-cell cavities: two of the Jlab high gradient (HG) shape and one of the ILC Low Loss shape. Two 9-cell TESLA shape cavities are presently in fabrication at Jlab and are close to completion.

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

    DOE Patents [OSTI]

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

    1999-01-01T23:59:59.000Z

    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.

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

    DOE Patents [OSTI]

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

    1999-06-01T23:59:59.000Z

    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.

  8. Fluctuation preserving coarse graining for biochemical systems

    E-Print Network [OSTI]

    Altaner, Bernhard

    2011-01-01T23:59:59.000Z

    Finite stochastic Markov models play a major role for modelling biochemical pathways. Such models are a coarse-grained description of the underlying microscopic dynamics and can be considered mesoscopic. The level of coarse-graining is to a certain extend arbitrary since it depends on the resolution of accomodating measurements. Here, we present a way to simplify such stochastic descriptions, which preserves both the meso-micro and the meso-macro connection. The former is achieved by demanding locality, the latter by considering cycles on the network of states. Using single- and multicycle examples we demonstrate how our new method preserves fluctuations of observables much better than na\\"ive approaches.

  9. Aphids on Texas Small Grains and sorghum.

    E-Print Network [OSTI]

    Hoelscher, Clifford E.; Thomas, John G.; Teetes, George L.

    1987-01-01T23:59:59.000Z

    , primarily wheat, provide the major winter host of greenbugs; sorghum is the major summer host in Texas. John songrass and other grasses serve as interim hosts when the growth of small grains and sorghum do not overlap. Oats may host greenbugs, but tends... found on small grains within the tightly curled leaf of the newest growth of the plant. As is the case with greenbugs, small populations of the Russian wheat aphid are not readily visible on casual observation. Infested plants some times have purple...

  10. 4-D XRD for strain in many grains using triangulation

    SciTech Connect (OSTI)

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

    2006-12-31T23:59:59.000Z

    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.

  11. Studies of physical characteristics and animal response to reconstituted sorghum grain

    E-Print Network [OSTI]

    Florence, Harold Douglas

    1968-01-01T23:59:59.000Z

    USSION SUMMAR Y Z3 53 67 LITERATURE CITED 71 LIST OF TABLES Table Page Index for estimating average particle size of ground sorghum grain. 18 Feedlot performance of bulls fed two feed mix- tures for 93 days (growing period), College Station..., 1967, 24 Feedlot performance of bulls fed four feed mix- tures for 102 days (finishing period), College Station, 1967. 26 Analysis of variance of daily gain 27 t- Test for differences in average daily gain Analysis of variance for average particle...

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

    SciTech Connect (OSTI)

    McKamey, C.G.

    2002-05-28T23:59:59.000Z

    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 new DOP-40 alloy could serve as a back-up alloy to be used if the costs of refining, handling, and transporting DOP-26 become prohibitively high.

  13. Quasi-Rheotaxy a new technique to grow large grain thin films on low cost amorphous substrates (*)

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    , could be used to build low cost thin film solar cells. Revue Phys. Appl. 16 (1981) 11-14 JANVIER 1981 is required in thin film direct gap absorbers solar cells to overcome thebfficiency value of 10 % is about 2 comparable with the grain size, reports that a thin film solar cell based on GaAs with a resistivity of 10

  14. LAMINAR: PRACTICAL FINE-GRAINED DECENTRALIZED INFORMATION

    E-Print Network [OSTI]

    Witchel, Emmett

    · Programming language based (PL) · Example: Jif, Flow Caml · Operating system based (OS) · Example: AsbestosLAMINAR: PRACTICAL FINE-GRAINED DECENTRALIZED INFORMATION FLOW CONTROL (DIFC) Indrajit Roy, Donald, SSN, personal calendar... But not every program you run is trusted Bugs in code, malicious plugins

  15. An analysis of international grain freight rates 

    E-Print Network [OSTI]

    Jonnala, Sneha Latha

    1999-01-01T23:59:59.000Z

    of the dependent variable was included in the model as an explanatory variable. The estimated econometric model was designed to explain ocean freight rates for grain. Results indicate rates increase at a decreasing rate with distance and rates decrease at a...

  16. Large grain cavities from pure niobium ingot

    DOE Patents [OSTI]

    Myneni, Ganapati Rao (Yorktown, VA); Kneisel, Peter (Williamsburg, VA); Cameiro, Tadeu (McMurray, PA)

    2012-03-06T23:59:59.000Z

    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.

  17. CROP & SOIL SCIENCES Small Grain Breeding

    E-Print Network [OSTI]

    Arnold, Jonathan

    CROP & SOIL SCIENCES Small Grain Breeding Committee Membership Dr. Paul Raymer - committee chair Dr. Scott Jackson Department of Crop & Soil Sciences Department of Crop & Soil Sciences University & Soil Sciences Department of Horticulture University of Georgia University of Georgia 2360 Rainwater Rd

  18. Oklahoma Small Grains Variety Performance Tests

    E-Print Network [OSTI]

    Balasundaram, Balabhaskar "Baski"

    Oklahoma Small Grains Variety Performance Tests 2012 - 2013 J.T. Edwards R.D. Kochenower R provided by: Oklahoma Wheat Commission Oklahoma Wheat Research Foundation OSU Cooperative Extension Service Central Research Station, Lahoma Lawrence Bohl, Oklahoma Panhandle Research and Extension Center, Goodwell

  19. Grain-scale Comminution and Alteration of Arkosic Rocks in the Damage Zone of the San Andreas Fault at SAFOD

    E-Print Network [OSTI]

    Heron, Bretani

    2012-02-14T23:59:59.000Z

    , the particle sizes are consistent with a power law distribution over the particle size range investigated (0.3 µm fractal dimension, D) is found to increase with shear strain and volume fraction of laumontite. This overall increase...

  20. Nature of Nano-Sized Plutonium Particles in Soils at the Hanford Site

    SciTech Connect (OSTI)

    Buck, Edgar C.; Moore, Dean A.; Czerwinski, Kenneth R.; Conradson, Steven D.; Batuk, Olga; Felmy, Andrew R.

    2014-08-06T23:59:59.000Z

    The occurrence of plutonium dioxide (PuO2) either from direct deposition or from the precipitation of plutonium-bearing solutions in contaminated soils and sediments has been well described, particularly for the Hanford site in Washington State. However, past research has suggested that plutonium may exist in environmental samples at the Hanford site in chemical forms in addition to large size PuO2 particles and that these previously unidentified nano-sized particles maybe more reactive and thus more likely to influence the environmental mobility of Pu. Here we present evidence for the formation of nano-sized plutonium iron phosphate hydroxide structurally related to the rhabdophane group nanoparticles in 216-Z9 crib sediments from Hanford using transmission electron microscopy (TEM). The distribution and nature of these nanoparticles varied depending on the adjacent phases present. Fine electron probes were used to obtain electron diffraction and electron energy-loss spectra from specific phase regions of the 216-Z9 cribs specimens from fine-grained plutonium oxide and phosphate phases. Energy-loss spectra were used to evaluate the plutonium N4,5 (4d ? 5f ) and iron L2,3 absorption edges. The iron plutonium phosphate formation may depend on the local micro-environment in the sediments, availability of phosphate, and hence the distribution of these minerals may control long-term migration of Pu in the soil. This study also points to the utility of using electron beam methods for determining the identity of actinide phases and their association with other sediment phases.

  1. Size reduction of complex networks preserving modularity

    SciTech Connect (OSTI)

    Arenas, A.; Duch, J.; Fernandez, A.; Gomez, S.

    2008-12-24T23:59:59.000Z

    The ubiquity of modular structure in real-world complex networks is being the focus of attention in many trials to understand the interplay between network topology and functionality. The best approaches to the identification of modular structure are based on the optimization of a quality function known as modularity. However this optimization is a hard task provided that the computational complexity of the problem is in the NP-hard class. Here we propose an exact method for reducing the size of weighted (directed and undirected) complex networks while maintaining invariant its modularity. This size reduction allows the heuristic algorithms that optimize modularity for a better exploration of the modularity landscape. We compare the modularity obtained in several real complex-networks by using the Extremal Optimization algorithm, before and after the size reduction, showing the improvement obtained. We speculate that the proposed analytical size reduction could be extended to an exact coarse graining of the network in the scope of real-space renormalization.

  2. Ground Versus Unground Grain for Lactating Dairy Cows.

    E-Print Network [OSTI]

    Darnell, A. L. (Albert Laurie); Copeland, O. C. (Orlin Cephas)

    1936-01-01T23:59:59.000Z

    . Table 10. Effects of Feeding Ground versus Whole Grain on High versus Low Producing Cows. Productive Values of Whole Grains Experiment Numbers Corn Experiment No. 1.. .... .... Corn Experiment No. 2.. ..... Oat Experiment No. 1.. Oat Experiment hTo...

  3. MESOSCALE THEORY OF GRAINS AND CELLS: POLYCRYSTALS & PLASTICITY

    E-Print Network [OSTI]

    Sethna, James P.

    MESOSCALE THEORY OF GRAINS AND CELLS: POLYCRYSTALS & PLASTICITY A Dissertation Presented RIGHTS RESERVED #12;MESOSCALE THEORY OF GRAINS AND CELLS: POLYCRYSTALS & PLASTICITY Surachate Limkumnerd, continuum explanation for the evolution of dislocations into sharp walls. We present here a mesoscale theory

  4. Strategy Guideline: HVAC Equipment Sizing

    SciTech Connect (OSTI)

    Burdick, A.

    2012-02-01T23:59:59.000Z

    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.

  5. Retrieval of subpixel snow covered area, grain size, and albedo from MODIS Thomas H. Painter a,

    E-Print Network [OSTI]

    Dozier, Jeff

    the energy and mass balance of the snow cover are its spatial extent and albedo (Blöschl, 1991; Dozier a Department of Geography, University of Utah, Salt Lake City, UT 84112, USA b Donald Bren School

  6. Mean grain size mapping with single-beam echo sounders Paul A. van Walreea

    E-Print Network [OSTI]

    a combination of theoretical and empirical relationships. In situ measurements of the seafloor mass density have to the sediment bulk value. The associated impedance gradient affects the normal-incidence reflection coefficient­5 The pres- ence of an acoustic impedance gradient considerably influ- ences the normal-incidence reflection

  7. NEW METHOD FOR GRAIN SIZE CHARACTERIZATION OF A MULTI-CRYSTALLINE SILICON INGOT

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    -crystalline Silicon (mc-Si) is the material with the largest market share in photovoltaic cells and mod- ules importance on the degradation of the electrical performance of the material, especially when these de- fects

  8. Reading Acquisition, Developmental Dyslexia, and Skilled Reading Across Languages: A Psycholinguistic Grain Size Theory

    E-Print Network [OSTI]

    Port, Robert

    Reading Acquisition, Developmental Dyslexia, and Skilled Reading Across Languages representations and accompanying differences in developmental reading strategies and the manifestation of dyslexia

  9. A Hyperspectral Method for Remotely Sensing the Grain Size of Snow

    E-Print Network [OSTI]

    Kurapov, Alexander

    , and instrument noise. MOTIVATION AND SIGNIFICANCE BACKGROUND Imaging spectrometry is a powerful tool that offers for calculating experiments, Hyva¨rinen and Lammasniemi (1987) related the snowpack's absorption of solar and Management, University of California A combination of remote sensing innovations and an Address

  10. Grain size control and microstructural evolution in nanocrystalline Ni-W alloys

    E-Print Network [OSTI]

    Detor, Andrew J. (Andrew Joseph)

    2007-01-01T23:59:59.000Z

    Nanocrystalline materials have been studied extensively over the past two decades because of their useful and interesting physical properties. In most cases, these properties derive from the fine characteristic length scale ...

  11. Core, Grain-Size, and Porosity Data from the Boise Hydrogeophysical Research Site

    E-Print Network [OSTI]

    Barrash, Warren

    .9. Gamma-Spectrometry Analysis Worksheets.....................................................83 #12;iii

  12. Z .Chemical Geology 158 1999 173188 Grain size separation and sediment mixing in Arctic Ocean

    E-Print Network [OSTI]

    Schöne, Bernd R.

    ' FBE . At the land­ocean transition the reduction of the particle velocity causes a deposition ages from the FBE reflect the age of the Siberian flood Z .basalt of about 220 Ma and the initial ratio samples from the western Laptev Sea Z . 143 144 west of 1208E fall between LME and FBE. Mixing

  13. INVESTIGATION OF PRESOLAR SILICATE GRAINS FROM ENSTATITE CHONDRITES.

    E-Print Network [OSTI]

    in SAH 97159 and six of the eight grains in SAH 97096 are 17 O-rich and belong to group 1, with likely eight O-anomalous grains each in SAH 97159 and SAH 97096, but none from Qingzhen. All eight grains are 18 O-rich and belong to group 4. One grain in SAH 97096 has a 17 O/16 O ratio of 134±1 (�10

  14. Suggestions for Controlling Insects in Farm-Stored Grain.

    E-Print Network [OSTI]

    Hamman, Philip J.

    1982-01-01T23:59:59.000Z

    of Infestations When storing grain in farm facilities, provide the least favorable conditions for insect development. Store clean, sound grain with 12 percent or less moisture content. Grain cot;ltaining more moisture at tracts insects, promotes mold growth...IUUL; Z TA24S.7 8873 NO.1410 Suggestions B-1410 for Controlling Insects ? In Farm-Stored Grain The Texas A&M University System ? Texas Agricultural Extension Service JUN 2 0 2002 Zerle L. Carpenter . Director College Station...

  15. RFID BASED GRAIN AND OIL PRODUCTS TRACEABILITY1

    E-Print Network [OSTI]

    Boyer, Edmond

    RFID BASED GRAIN AND OIL PRODUCTS TRACEABILITY1 AND ITS COMPUTER IMPLEMENTATION Haiyan Hu ,*2 the study of the traceability of grain and oil products. Include the study contents, and a system we developed for traceability of grain and oil products, and the demonstration of the study. The system we

  16. ANNIVERSARY REVIEW Grain boundary energy anisotropy: a review

    E-Print Network [OSTI]

    Rohrer, Gregory S.

    energy (B) gained when the two surfaces are brought together and new bonds are formed. The grain boundaryANNIVERSARY REVIEW Grain boundary energy anisotropy: a review Gregory S. Rohrer Received: 29 April 2011 Abstract This paper reviews findings on the anisotropy of the grain boundary energies. After

  17. LBNL -42691 Leakage Diagnostics, Sealant Longevity, Sizing

    E-Print Network [OSTI]

    LBNL - 42691 1 Leakage Diagnostics, Sealant Longevity, Sizing and Technology Transfer of or agreement with these findings, nor that of any CIEE sponsor. #12;LBNL - 42691 2 Leakage Diagnostics, Sealant of the Residential Thermal Distribution Systems research done by Lawrence Berkeley National Laboratory (LBNL

  18. Characterization of secondary grain dust explosions

    E-Print Network [OSTI]

    Schulman, Cheryl Wendler

    1983-01-01T23:59:59.000Z

    explosion These include& an ignition source; oxygeni s confined space; and fuel, which 1n most instances is grain dust held. in suspension at concentration levels in excess of the minimum explosive concentration (MEC) (Palmer, 197$). The MEC is defined.... as the minimum concentration of dust in a cloud. necessary for sustained flame propagation. The MEC is also sometimes referred to as the lower explosive limit (LZL). The lower level of explosibility for most dusts ranges from 20 to 70 This thesis follows...

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

    DOE Patents [OSTI]

    McCallum, R. William (Ames, IA); Branagan, Daniel J. (Ames, IA)

    1996-01-23T23:59:59.000Z

    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.

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

    DOE Patents [OSTI]

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

    1996-01-23T23:59:59.000Z

    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.

  1. Characterization of grain boundary conductivity of spin-sprayed ferrites using scanning microwave microscope

    SciTech Connect (OSTI)

    Myers, J.; Nicodemus, T.; Zhuang, Y., E-mail: yan.zhuang@wright.edu [Department of Electrical Engineering, Wright State University, Dayton, Ohio 45435 (United States); Watanabe, T.; Matsushita, N. [Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama (Japan); Yamaguchi, M. [Department of Electrical Engineering, Tohoku University, Sendai 980-8579 (Japan)

    2014-05-07T23:59:59.000Z

    Grain boundary electrical conductivity of ferrite materials has been characterized using scanning microwave microscope. Structural, electrical, and magnetic properties of Fe{sub 3}O{sub 4} spin-sprayed thin films onto glass substrates for different length of growth times were investigated using a scanning microwave microscope, an atomic force microscope, a four-point probe measurement, and a made in house transmission line based magnetic permeameter. The real part of the magnetic permeability shows almost constant between 10 and 300?MHz. As the Fe{sub 3}O{sub 4} film thickness increases, the grain size becomes larger, leading to a higher DC conductivity. However, the loss in the Fe{sub 3}O{sub 4} films at high frequency does not increase correspondingly. By measuring the reflection coefficient s{sub 11} from the scanning microwave microscope, it turns out that the grain boundaries of the Fe{sub 3}O{sub 4} films exhibit higher electric conductivity than the grains, which contributes loss at radio frequencies. This result will provide guidance for further improvement of low loss ferrite materials for high frequency applications.

  2. What determines cell size?

    E-Print Network [OSTI]

    2012-01-01T23:59:59.000Z

    mechanism for nuclear positioning in fission yeast based onboth budding and fission yeast that nuclear volume increasesFR, Nurse P: Nuclear size control in fission yeast. J Cell

  3. The distribution of Voronoi cells generated by Southern California earthquake epicenters

    E-Print Network [OSTI]

    Schoenberg, Frederic P; Barr, Christopher; Jungju Seo

    2007-01-01T23:59:59.000Z

    Continuous Univariate Distributions. 2nd ed. Wiley, Newfor the tapered Pareto distribution. Journal of AppliedWoods, J. (2003) On the distribution of wild?re sizes. Envi-

  4. Spectroscopic diagnostic for the mineralogy of large dust grains

    E-Print Network [OSTI]

    M. Min; C. Dominik; L. B. F. M. Waters

    2003-10-30T23:59:59.000Z

    We examine the thermal infrared spectra of large dust grains of different chemical composition and mineralogy. Strong resonances in the optical properties result in detectable spectral structure even when the grain is much larger than the wavelength at which it radiates. We apply this to the thermal infrared spectra of compact amorphous and crystalline silicates. The weak resonances of amorphous silicates at 9.7 and 18 micron virtually disappear for grains larger than about 10 micron. In contrast, the strong resonances of crystalline silicates produce emission dips in the infrared spectra of large grains; these emission dips are shifted in wavelength compared to the emission peaks commonly seen in small crystalline silicate grains. We discuss the effect of a fluffy or compact grain structure on the infrared emission spectra of large grains, and apply our theory to the dust shell surrounding Vega.

  5. The shape and composition of interstellar silicate grains

    E-Print Network [OSTI]

    M. Min; L. B. F. M. Waters; A. de Koter; J. W. Hovenier; L. P. Keller; F. Markwick-Kemper

    2006-11-10T23:59:59.000Z

    We investigate the composition and shape distribution of silicate dust grains in the interstellar medium. The effect of the amount of magnesium in the silicate lattice is studied. We fit the spectral shape of the interstellar 10 mu extinction feature as observed towards the galactic center. We use very irregularly shaped coated and non-coated porous Gaussian Random Field particles as well as a statistical approach to model shape effects. For the dust materials we use amorphous and crystalline silicates with various composition and SiC. The results of our analysis of the 10 mu feature are used to compute the shape of the 20 mu silicate feature and to compare this with observations. By using realistic particle shapes we are, for the first time, able to derive the magnesium fraction in interstellar silicates. We find that the interstellar silicates are highly magnesium rich (Mg/(Fe+Mg)>0.9) and that the stoichiometry lies between pyroxene and olivine type silicates. This composition is not consistent with that of the glassy material found in GEMS in interplanetary dust particles indicating that these are, in general, not unprocessed remnants from the interstellar medium. Also, we find a significant fraction of SiC (~3%). We discuss the implications of our results for the formation and evolutionary history of cometary and circumstellar dust. We argue that the fact that crystalline silicates in cometary and circumstellar grains are almost purely magnesium silicates is a natural consequence of our findings that the amorphous silicates from which they were formed were already magnesium rich.

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

    SciTech Connect (OSTI)

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

    1985-10-01T23:59:59.000Z

    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.

  7. Premelting, fluctuations, and coarse-graining of water-ice interfaces

    SciTech Connect (OSTI)

    Limmer, David T., E-mail: dlimmer@princeton.edu [Princeton Center for Theoretical Science, Princeton University, Princeton, New Jersey 08540 (United States); Chandler, David [Department of Chemistry, University of California, Berkeley, California 94609 (United States)

    2014-11-14T23:59:59.000Z

    Using statistical field theory supplemented with molecular dynamics simulations, we consider premelting on the surface of ice as a generic consequence of broken hydrogen bonds at the boundary between the condensed and gaseous phases. A procedure for coarse-graining molecular configurations onto a continuous scalar order parameter field is discussed, which provides a convenient representation of the interface between locally crystal-like and locally liquid-like regions. A number of interfacial properties are straightforwardly evaluated using this procedure such as the average premelting thickness and surface tension. The temperature and system size dependence of the premelting layer thickness calculated in this way confirms the characteristic logarithmic growth expected for the scalar field theory that the system is mapped onto through coarse-graining, though remains finite due to long-ranged interactions. Finally, from explicit simulations the existence of a premelting layer is shown to be insensitive to bulk lattice geometry, exposed crystal face, and curvature.

  8. Grain quality impacts of prohibiting recombination recirculation dust at export grain elevators

    E-Print Network [OSTI]

    Spillmann, Daryl Drew

    1992-01-01T23:59:59.000Z

    such as those where grain moves from one belt conveyor to another, one auger to another, into and out of a bucket elevator, or into and out of storage bins. Typically, a cloud of dust is created at each transfer point. Since this dust cloud.... Dust ventilation is energy intensive and can account for a large portion (one-third to one-half) of an elevator's electrical energy cost (Whitelock, 1991). National Grain and Feed Association (1981) and National Materials Advisory Board (1982) have...

  9. Atomistic Simulation of Slow Grain Boundary Motion

    SciTech Connect (OSTI)

    Deng Chuang; Schuh, Christopher A. [Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States)

    2011-01-28T23:59:59.000Z

    Existing atomistic simulation techniques to study grain boundary motion are usually limited to either high velocities or temperatures and are difficult to compare to realistic experimental conditions. Here we introduce an adapted simulation method that can access boundary velocities in the experimental range and extract mobilities in the zero driving force limit at temperatures as low as {approx}0.2T{sub m} (T{sub m} is the melting point). The method reveals three mechanistic regimes of boundary mobility at zero net velocity depending on the system temperature.

  10. Legal Issues Involving Cash Forward Grain Contracts

    E-Print Network [OSTI]

    McEowen, Roger A.

    1999-06-23T23:59:59.000Z

    requirement unclear and may be illegal under Commodity Future Trading Commission (CFTC) regulations that ban trade options (an off-exchange deriva- tive) on agricultural commodities. This has been a major issue since 1996 and the run-up in grain prices... the HTA con- tract and requiring the farmer to deliver, and others determining the contracts to be illegal under the CFTC ban. In general, HTA contracts will be upheld as cash-forward contracts if a court or arbitrator can determine that the con- tracts...

  11. Heartland Grain Fuels LP | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are8COaBulkTransmissionSitingProcess.pdfGetec AG|Information OpenEIHas BeenLegalHeard County,Grain Fuels LP Jump

  12. aerosol particle size: Topics by E-print Network

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

    (AD... Dileep, V.R. 2012-06-07 79 Scale-free Universal Spectrum for Atmospheric Aerosol Size Distribution for Davos, Mauna Loa and Izana Physics (arXiv) Summary: Atmospheric flows...

  13. agglomerates sizes approach: Topics by E-print Network

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

    Lorenzo Isella; Yannis Drossinos 2010-04-26 52 A fractal-based approach to lake size-distributions David A. Seekell,1 Environmental Sciences and Ecology Websites Summary:...

  14. air gaps size: Topics by E-print Network

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

    cars in a number of roads in central London is well represented by the spacing distribution of a Gaussian unitary ensemble. Abul-Magd, A Y 2006-01-01 29 The Role of Size in...

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

    DOE Patents [OSTI]

    Huber, Dale L. (Albuquerque, NM)

    2011-07-05T23:59:59.000Z

    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. Control of pore size in epoxy systems.

    SciTech Connect (OSTI)

    Sawyer, Patricia Sue; Lenhart, Joseph Ludlow (North Dakota State University, Fargo, ND); Lee, Elizabeth (North Dakota State University, Fargo, ND); Kallam, Alekhya (North Dakota State University, Fargo, ND); Majumdar, Partha (North Dakota State University, Fargo, ND); Dirk, Shawn M.; Gubbins, Nathan; Chisholm, Bret J. (North Dakota State University, Fargo, ND); Celina, Mathias Christopher; Bahr, James (North Dakota State University, Fargo, ND); Klein, Robert J.

    2009-01-01T23:59:59.000Z

    Both conventional and combinatorial approaches were used to study the pore formation process in epoxy based polymer systems. Sandia National Laboratories conducted the initial work and collaborated with North Dakota State University (NDSU) using a combinatorial research approach to produce a library of novel monomers and crosslinkers capable of forming porous polymers. The library was screened to determine the physical factors that control porosity, such as porogen loading, polymer-porogen interactions, and polymer crosslink density. We have identified the physical and chemical factors that control the average porosity, pore size, and pore size distribution within epoxy based systems.

  17. Wave propagation, stress relaxation, and grain-to-grain shearing in saturated, unconsolidated marine sediments

    E-Print Network [OSTI]

    Buckingham, Michael

    of Sound and Vibration Research, The University, Southampton SO17 1BJ, United Kingdom Received 1 February. Since the grains are unbonded, it is assumed that the shear rigidity modulus of the medium is zero, implying the absence of a skeletal elastic frame. The analysis is based on two types of shearing

  18. Structural Dependence of Grain Boundary Resistance in Copper Nanowires

    SciTech Connect (OSTI)

    Kim, Tae Hwan [ORNL; Zhang, Xiaoguang [ORNL; Nicholson, Don M [ORNL; Radhakrishnan, Bala [ORNL; Radhakrishnan, Balasubramaniam [ORNL; Evans III, Boyd Mccutchen [ORNL; Kulkarni, Nagraj S [ORNL; Kenik, Edward A [ORNL; Meyer III, Harry M [ORNL; Li, An-Ping [ORNL

    2011-01-01T23:59:59.000Z

    The current choice of the interconnect metal in integrated circuits is copper due to its higher electrical conductivity and improved electromigration reliability in comparison with aluminum. However, with reducing feature sizes, the resistance of copper interconnects (lines) increases dramatically. Greater resistance will result in higher energy use, more heat generation, more failure due to electromigration, and slower switching speeds. To keep pace with the projected planar transistor density, the first challenge is to identify the dominant factors that contribute to the high interconnect resistance. Here we directly measure individual grain boundary (GB) resistances in copper nanowires with a one-to-one correspondence to the GB structure. The specific resistivities of particular GBs are measured using four-probe scanning tunneling microscopy (STM) to establish a direct link between GB structure and the resistance. High-angle random GBs contribute to a specific resistivity of about 25 10-12 cm2 for each boundary, while coincidence boundaries are significantly less-resistive than random boundaries. Thus, replacing random boundaries with coincidence ones would be a route to suppress the GB impact to the resistivity of polycrystalline conductors. Acknowledgement: The research was supported by the Division of Scientific User Facilities, U. S. Department of Energy.

  19. Mesoscopic superconductivity in ultrasmall metallic grains

    SciTech Connect (OSTI)

    Alhassid, Y. [Center for Theoretical Physics, Sloane Physics Laboratory, Yale University, New Haven, CT 06520 (United States); Nesterov, K. N. [Center for Theoretical Physics, Sloane Physics Laboratory, Yale University, New Haven, CT 06520 (United States); CEA, INAC-SPSMS, F-38000 Grenoble (France)

    2014-10-15T23:59:59.000Z

    A nano-scale metallic grain (nanoparticle) with irregular boundaries in which the single-particle dynamics are chaotic is a zero-dimensional system described by the so-called universal Hamiltonian in the limit of a large number of electrons. The interaction part of this Hamiltonian includes a superconducting pairing term and a ferromagnetic exchange term. Spin-orbit scattering breaks spin symmetry and suppresses the exchange interaction term. Of particular interest is the fluctuation-dominated regime, typical of the smallest grains in the experiments, in which the bulk pairing gap is comparable to or smaller than the single-particle mean-level spacing, and the Bardeen-Cooper-Schrieffer (BCS) mean-field theory of superconductivity is no longer valid. Here we study the crossover between the BCS and fluctuation-dominated regimes in two limits. In the absence of spin-orbit scattering, the pairing and exchange interaction terms compete with each other. We describe the signatures of this competition in thermodynamic observables, the heat capacity and spin susceptibility. In the presence of strong spin-orbit scattering, the exchange interaction term can be ignored. We discuss how the magnetic-field response of discrete energy levels in such a nanoparticle is affected by pairing correlations. We identify signatures of pairing correlations in this response, which are detectable even in the fluctuation-dominated regime.

  20. Size separation in vibrated granular matter

    E-Print Network [OSTI]

    A. Kudrolli

    2004-02-06T23:59:59.000Z

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

  1. Microstructure and Strengthening Mechanisms in an Ultrafine Grained Al-Mg-Sc Alloy Produced by Powder Metallurgy

    SciTech Connect (OSTI)

    Tammy J. Harrell; Troy D. Topping; Haiming Wen; Tao Hu; JULIE M. SCHOENUNG; ENRIQUE J. LAVERNIA

    2014-12-01T23:59:59.000Z

    Additions of Sc to an Al-Mg matrix were investigated, paying particular attention to the influence of Al3Sc precipitates and other dispersoids, as well as grain size, on mechanical behavior. Prior studies have shown that Sc significantly increases the strength of coarse-grained Al-Mg alloys. Prompted by these findings, we hypothesized that it would be of fundamental and technological interest to study the behavior of Sc additions to an ultrafine-grained (UFG) microstructure (e.g., 100’s nm). Accordingly, we investigated the microstructural evolution and mechanical behavior of a cryomilled ultrafine grained Al-5Mg-0.4Sc (wt pct) and compared the results to those of an equivalent fine-grained material (FG) produced by powder metallurgy. Experimental materials were consolidated by hot isostatic pressing (HIP’ing) followed by extrusion or dual mode dynamic forging. Under identical processing conditions, UFG materials generate large Al3Sc precipitates with an average diameter of 154 nm and spaced approximately 1 to 3 µm apart, while precipitates in the FG materials have a diameter of 24 nm and are spaced 50 to 200 nm apart. The strengthening mechanisms are calculated for all materials and it is determined that the greatest strengthening contributions for the UFG and FG materials are Mg-O/N dispersion strengthening and precipitate strengthening, respectively.

  2. PRAM C:a new programming environment for fine-grain and coarse-grain parallelism.

    SciTech Connect (OSTI)

    Brown, Jonathan Leighton; Wen, Zhaofang.

    2004-11-01T23:59:59.000Z

    In the search for ''good'' parallel programming environments for Sandia's current and future parallel architectures, they revisit a long-standing open question. Can the PRAM parallel algorithms designed by theoretical computer scientists over the last two decades be implemented efficiently? This open question has co-existed with ongoing efforts in the HPC community to develop practical parallel programming models that can simultaneously provide ease of use, expressiveness, performance, and scalability. Unfortunately, no single model has met all these competing requirements. Here they propose a parallel programming environment, PRAM C, to bridge the gap between theory and practice. This is an attempt to provide an affirmative answer to the PRAM question, and to satisfy these competing practical requirements. This environment consists of a new thin runtime layer and an ANSI C extension. The C extension has two control constructs and one additional data type concept, ''shared''. This C extension should enable easy translation from PRAM algorithms to real parallel programs, much like the translation from sequential algorithms to C programs. The thin runtime layer bundles fine-grained communication requests into coarse-grained communication to be served by message-passing. Although the PRAM represents SIMD-style fine-grained parallelism, a stand-alone PRAM C environment can support both fine-grained and coarse-grained parallel programming in either a MIMD or SPMD style, interoperate with existing MPI libraries, and use existing hardware. The PRAM C model can also be integrated easily with existing models. Unlike related efforts proposing innovative hardware with the goal to realize the PRAM, ours can be a pure software solution with the purpose to provide a practical programming environment for existing parallel machines; it also has the potential to perform well on future parallel architectures.

  3. Selected Operating Costs for Storage of Sorghum Grain.

    E-Print Network [OSTI]

    Bonnen, C. A. (Clarence Alfred); Cunningham, William C.

    1964-01-01T23:59:59.000Z

    Selected Operating Costs for Storage Of Sorghum Grain TEXAS A&M UNIVERSITY This is the third of three bulletins reporting the results of a study of sorghum grain storage and handling practices in Texas. The first dealt with marketing and on...-farm storage; the second with com- mercial storage and handling practices. This bulletin reports the results of a study of the costs of com- mercial grain handling practices. Three areas representing a cross section of physical and economic conditions...

  4. Grain Sorghum By-Product Feeds for Farm Animals.

    E-Print Network [OSTI]

    1951-01-01T23:59:59.000Z

    X3.AJ.N SORGHUM BY-PRODUCT FEEDS FOR FARM ANIMALS FEED FOR LIVESTOCK -. Grain sorghum is the leading feed grain produced in Texas and in the Southwest. Its importance as a feed fc farm animals is generally recognized. Recent developments... in Texas have made available 1 livestock producers and the feed industry a considerab tonnage of sorghum gluten meal and sorghum gluten fee as by-products in sorghum grain processing. The Texas Agricultural Experiment Station conduct( a series...

  5. Ice particle size matters | EMSL

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

    Ice particle size matters Ice particle size matters Released: May 04, 2014 Fine-tuning cloud models for improved climate predictions The Science Arctic clouds are widespread and...

  6. Mono-textured nanocrystalline thin films with pronounced stress-gradients: On the role of grain boundaries in the stress evolution

    SciTech Connect (OSTI)

    Daniel, R., E-mail: Rostislav.Daniel@unileoben.ac.at; Mitterer, C. [Department of Physical Metallurgy and Materials Testing, Montanuniversität Leoben, Franz-Josef-Strasse 18, 8700 Leoben (Austria); Jäger, E.; Sartory, B. [Materials Center Leoben Forschung GmbH, Leoben (Austria); Todt, J.; Keckes, J. [Department of Materials Physics, Montanuniversität Leoben and Erich Schmid Institute for Materials Science, Austrian Academy of Sciences, Leoben (Austria)

    2014-05-28T23:59:59.000Z

    The origins of residual stress gradients in nanocrystalline thin films, especially the role of grain size and texture gradients, are still not fully understood. In this work, the stress evolution in exemplary nanocrystalline TiN thin films with one and two fiber texture components as well as in homogeneous amorphous SiO{sub x} films is analyzed using wafer curvature as well as laboratory and synchrotron cross-sectional nanobeam X-ray diffraction techniques. The stress evolution across the film thickness is attributed to the evolutionary nature of microstructural development at the individual growth stages. While the effect of the smooth crystallographic texture changes during growth is only of minor importance, as this does not significantly affect the dominant stress formation mechanisms, the change in the grain size accompanied by a change of the volume fraction of grain boundaries plays a decisive role in the stress development across the film thickness. This is demonstrated on the monotextured thin films, where the residual stresses scale with the apparent grain size. These findings are validated also by the investigations of stress profiles in homogeneous amorphous SiO{sub x} films exhibiting no grain boundaries.

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

    SciTech Connect (OSTI)

    Leonard, T.; Lander, B.; Seifert, U. [II. Institut für Theoretische Physik, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart (Germany)] [II. Institut für Theoretische Physik, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart (Germany); Speck, T. [Institut für Theoretische Physik II, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, 40225 Düsseldorf (Germany)] [Institut für Theoretische Physik II, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, 40225 Düsseldorf (Germany)

    2013-11-28T23:59:59.000Z

    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.

  8. Grain Handling What if "IT" happens to you?

    E-Print Network [OSTI]

    Jones, Carol

    , filter respirators, SCBA. #12;Rescue DON'T TRY TO PULL VICTIM OUT!!! 53 lb. child, knee-deep grain = 71

  9. Grain growth and phase stability of nanocrystalline cubic zirconia...

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

    of nanocrystalline cubic zirconia under ion irradiation. Abstract: Grain growth, oxygen stoichiometry and phase stability of nanostructurally-stabilized zirconia (NSZ) in...

  10. Sample sizes for confidence limits for reliability.

    SciTech Connect (OSTI)

    Darby, John L.

    2010-02-01T23:59:59.000Z

    We recently performed an evaluation of the implications of a reduced stockpile of nuclear weapons for surveillance to support estimates of reliability. We found that one technique developed at Sandia National Laboratories (SNL) under-estimates the required sample size for systems-level testing. For a large population the discrepancy is not important, but for a small population it is important. We found that another technique used by SNL provides the correct required sample size. For systems-level testing of nuclear weapons, samples are selected without replacement, and the hypergeometric probability distribution applies. Both of the SNL techniques focus on samples without defects from sampling without replacement. We generalized the second SNL technique to cases with defects in the sample. We created a computer program in Mathematica to automate the calculation of confidence for reliability. We also evaluated sampling with replacement where the binomial probability distribution applies.

  11. 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. (Dnipropetrovsk, UA); Noyes, Ronald T. (Stillwater, OK); Potapovych, Larysa P. (Dnipropetrovsk, UA)

    2012-02-28T23:59:59.000Z

    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.

  12. Optimum Size of Nanorods for Heating Application

    E-Print Network [OSTI]

    Seshadri, Gowrishankar; Mehra, Anurag

    2013-01-01T23:59:59.000Z

    Magnetic nanoparticles (MNP's) have become increasingly important in heating applications such as hyperthermia treatment of cancer due to their ability to release heat when a remote external alternating magnetic field is applied. It has been shown that the heating capability of such particles varies significantly with the size of particles used. In this paper, we theoretically evaluate the heating capability of rod-shaped MNP's and identify conditions under which these particles display highest efficiency. For optimally sized monodisperse particles, the power generated by rod-shaped particles is found to be equal to that generated by spherical particles. However, for particles which have a dispersion in size, rod-shaped particles are found to be more effective in heating as a result of the greater spread in the power density distribution curve. Additionally, for rod-shaped particles, a dispersion in the radius of the particle contributes more to the reduction in loss power when compared to a dispersion in the...

  13. Natural geological responses to anthropogenic alterations of the naples bay estuarine system

    E-Print Network [OSTI]

    Fielder, Bryan Robert

    2009-05-15T23:59:59.000Z

    content. Grain size distribution for the grab samples and vibracores was evaluated using a Malvern? Mastersizer 2000 TM (Malvern, UK). The Mastersizer 2000 is a particle size analyzer using laser diffraction to produce a grain size distribution...

  14. 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. [Department of Mechanical Engineering, Texas A and M University, TX 77843 (United States); Robinson, J.; Barber, R. E. [Shear Form Inc, 207 Dellwood St, Bryan 77801 (United States)

    2014-01-27T23:59:59.000Z

    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.

  15. 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)

    2014-11-01T23:59:59.000Z

    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.

  16. Aerosol measurements at a high-elevation site: composition, size, and cloud condensation nuclei activity

    E-Print Network [OSTI]

    Friedman, B.

    Measurements of cloud condensation nuclei (CCN) concentrations, single particle composition and size distributions at a high-elevation research site from March 2011 are presented.

  17. Edison Job Size Charts

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisitingContract ManagementDiscoveringESnet UpdateEarth WeekAlamosEdisonEdisonJob Size

  18. Mechanism of grain growth during severe plastic deformation of a nanocrystalline Ni-Fe alloy

    SciTech Connect (OSTI)

    Li, Hongqi [Los Alamos National Laboratory; Wang, Y B [NON LANL; Ho, J C [NON LANL; Liao, X Z [NON LANL; Zhu, Y T [NON LANL; Ringer, S P [NON LANL

    2009-01-01T23:59:59.000Z

    Deformation induced grain growth has been widely reported in nanocrystalline materials. However, the grain growth mechanism remains an open question. This study applies high-pressure torsion to severely deform bulk nanocrystalline Ni-20 wt % Fe disks and uses transmission electron microscopy to characterize the grain growth process. Our results provide solid evidence suggesting that high pressure torsion induced grain growth is achieved primarily via grain rotation for grains much smaller than 100 nm. Dislocations are mainly seen at small-angle subgrain boundaries during the grain growth process but are seen everywhere in grains after the grains have grown large.

  19. Kefir grain tolerance to Escherichia coli contamination--industrial advantages

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    NOTE Kefir grain tolerance to Escherichia coli contamination--industrial advantages Piotr the possibility of the re-use of kefir grains grown at 18 °C for 24 h in pasteurized Escherichia coli contaminated milk up to 6.1×102 cfu.mL-1 . The contamination rate was adapted to a realistic situation which may

  20. Samples of Stars Beyond the Solar System: Silicate Grains in

    E-Print Network [OSTI]

    Samples of Stars Beyond the Solar System: Silicate Grains in Interplanetary Dust Scott Messenger,1 circumstellar silicate grains within interplanetary dust par- ticles (IDPs). Their extrasolar origins are amorphous silicate "GEMS" (glass with embedded metal and sulfides), which is consistent with astronomical

  1. Managing Fusarium Head Blight in Virginia Small Grains

    E-Print Network [OSTI]

    Liskiewicz, Maciej

    Breeder, Dept. of Crop and Soil Environmental Sciences, Virginia Tech. cgriffey@vt.edu C.J. LIN Vice@vt.edu WADE THOMASON Extension Grains Specialist, Dept. of Crop and Soil Environmental Sciences, Virginia TechManaging Fusarium Head Blight in Virginia Small Grains MELISSA KELLER Graduate Student, Dept

  2. Uniform Distribution

    E-Print Network [OSTI]

    randomly and equally likely a point in that interval), the uniform distribution ... Roughly speaking, this means that from any distribution we can create the uniform.

  3. 2007 OUTBURST OF 17P/HOLMES: THE ALBEDO AND THE TEMPERATURE OF THE DUST GRAINS

    SciTech Connect (OSTI)

    Ishiguro, Masateru; Watanabe, Jun-ichi; Fukushima, Hideo [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Sarugaku, Yuki; Mito, Hiroyuki [Institute of Space and Astronautical Science, JAXA, 3-1-1, Yoshinodai, Chuo, Sagamihara, Kanagawa 252-5210 (Japan); Ootsubo, Takafumi [Graduate School of Science, Tohoku University, 6-3 Aramaki, Aoba-ku, Sendai 980-8578 (Japan); Kuroda, Daisuke; Yanagisawa, Kenshi [Okayama Astrophysical Observatory, NAOJ, 3037-5 Honjo, Kamogata, Asakuchi, Okayama 719-0232 (Japan); Honda, Mitsuhiko [Faculty of Science, Kanagawa University, 2946 Tsuchiya, Hiratsuka, Kanagawa 259-1293 (Japan); Miyata, Takashi [Institute of Astronomy, University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan); Niwa, Takahiro; Sakamoto, Makoto; Narusawa, Shin-ya [Nishi-Harima Astronomical Observatory, 407-2 Nishigaichi, Sayo, Hyogo 679-5313 (Japan); Akisawa, Hiroki, E-mail: ishiguro@astro.snu.ac.k [Himeji City Hoshinoko Yakata, Aoyama 1470-24, Himeji, Hyogo 671-2222 (Japan)

    2010-05-10T23:59:59.000Z

    Based on optical and infrared observations, we study the albedo and the temperature of the dust grains associated with the spectacular 2007 outburst of Jupiter-family comet 17P/Holmes. We found that the albedo at the solar phase angle {approx}16{sup 0} was 0.03-0.12. While the color temperature around 3-4 {mu}m was 360 {+-} 40 K, the color temperature at 12.4 {mu}m and 24.5 {mu}m was {approx}200 K, which is consistent with that of a blackbody. We studied the equilibrium temperature of the dust grains at 2.44 AU and found that the big discrepancy in the temperature was caused by the heterogeneity in particle size, that is, hotter components consist of submicron absorbing grains whereas colder components consist of large ({approx_gt}1 {mu}m) grains. The contemporaneous optical and mid-infrared observations suggest that the albedo and the temperature could decrease within {approx} 3 days after the outburst and stabilized at typical values of the other comets. We estimated the total mass injected into the coma by the outburst on the basis of the derived albedo and the optical magnitude for the entire dust cloud, and found that at least 4 x 10{sup 10} kg (equivalent to a few meter surface layer) was removed by the initial outburst event. The derived mass suggests that the outburst is explainable by neither the exogenetic asteroidal impact nor water ice sublimation driven by solar irradiation, but by an endogenic energy source. We conclude that the outburst was triggered by the energy sources several meters or more below the nuclear surface.

  4. Population growth, distribution, and size in Latin America

    E-Print Network [OSTI]

    Lopez-Carr, David

    timber harvesting oil exploration/extraction population growth? degradation of lands in source areas history in Amazonia · Early extractive uses Rubber Forestry #12;Development history in Amazonia forests in the world 2) 45% of all the fresh water on the Earth 3) the planet's largest carbon sink 4

  5. The geographic distribution of mammal body size in Europe

    E-Print Network [OSTI]

    Rodriguez, M A; Lopez-Sanudo, I L; Hawkins, Bradford A.

    2006-01-01T23:59:59.000Z

    Nacionales, Madrid. Peltier, W. (1993) Time dependentlast glacial maximum (Peltier, 1993). This variable measures

  6. The geographic distribution of mammal body size in Europe

    E-Print Network [OSTI]

    Rodriguez, M A; Lopez-Sanudo, I L; Hawkins, Bradford A.

    2006-01-01T23:59:59.000Z

    cell age), estim- ated by mapped changes in ice coverage at 1-Kyr intervals since the last glacial maximum (Peltier,

  7. aerosol size distributions: Topics by E-print Network

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

    for Davos, Mauna Loa and Izana Physics (arXiv) Summary: Atmospheric flows exhibit fractal fluctuations and inverse power law form for power spectra indicating an eddy...

  8. aerosol size distribution: Topics by E-print Network

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

    for Davos, Mauna Loa and Izana Physics (arXiv) Summary: Atmospheric flows exhibit fractal fluctuations and inverse power law form for power spectra indicating an eddy...

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

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

    ECD-1 CRT CNG1 CNG2 Carbonyl Compounds (Air Toxics) Formaldehyde Acetaldehyde Acetone Acrolein Propionaldehyde Croton Methyl ethyl Ketone (MEK) Methylacrolein Butanal Benzaldehyde...

  10. Estimating sandstone permeability using network models with pore size distributions

    E-Print Network [OSTI]

    Mathews, Alan Ronald

    1991-01-01T23:59:59.000Z

    the effects of each parameter on the response of the network lattice. A FoR+RAv source code was written to generate and analyze the response of the network model (see Appendix G for source code description and flow chart). The controlling parameters used... in appearance to empirical data. A network model is developed to simulate the pore geometry of a clean, well-sorted sandstone. Pores were modeled as straight capillaries connected in various lattice configurations. Complex lattice configurations produce more...

  11. Assessing Impact of Shattered Artifacts on Measured Size Distributions

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office511041cloth DocumentationProductsAlternativeOperational Management »EnergyHubs | DepartmentCloud

  12. Evolution of droplet size distribution and autoconversion parameterization

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField8,Dist. Category UC-l 1, 13Evacuation248 EvaluationMAYEvidencein

  13. Concentrations and Size Distributions of Particulate Matter Emissions from

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny: Theof"Wave the WhiteNational|ofSeptember 3,Bringing youProgram AreasCatalyzed

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

    SciTech Connect (OSTI)

    Uberuaga, Blas P. [Los Alamos National Laboratory

    2012-05-02T23:59:59.000Z

    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 altered at this particular grain boundary. Given that the diffusion of fission gases such as Xe are tied to the mobility of uranium vacancies, these results given insight into how fission gas mobility differs at grain boundaries compared to bulk urania.

  15. Irradiation Assisted Grain Boundary Segregation in Steels

    SciTech Connect (OSTI)

    Lu, Zheng; Faulkner, Roy G. [IPTME, Loughborough University, Loughborough, Leics (United Kingdom)

    2008-07-01T23:59:59.000Z

    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)

  16. Feeding Value of Wet Sorghum Distillers Grains for Growing and Finishing Beef Cattle

    E-Print Network [OSTI]

    Feeding Value of Wet Sorghum Distillers Grains for Growing and Finishing Beef Cattle Ethanol, but sorghum grain is commonly either blended with corn before use or used as the sole grain for ethanol

  17. Estimation of grain boundary segregation enthalpy and its role in stable nanocrystalline alloy design

    E-Print Network [OSTI]

    Schuh, Christopher A.

    Grain boundary segregation provides a method for stabilization of nanocrystalline metals—an alloying element that will segregate to the boundaries can lower the grain boundary energy, attenuating the driving force for grain ...

  18. Grain boundary and triple junction constraints during martensitic transformation in shape memory alloys

    E-Print Network [OSTI]

    Ueland, Stian Melhus

    We investigate the role of grain constraint upon martensitic transformation through in situ scanning electron microscope tensile experiments on shape memory microwires with a small number of grains and grain junctions. The ...

  19. DUST GRAIN EVOLUTION IN SPATIALLY RESOLVED T TAURI BINARIES

    SciTech Connect (OSTI)

    Skemer, Andrew J.; Close, Laird M.; Hinz, Philip M.; Hoffmann, William F.; Males, Jared R. [Steward Observatory, Department of Astronomy, University of Arizona, Tucson, AZ 85721 (United States); Greene, Thomas P. [NASA Ames Research Center, Moffett Field, CA 94035 (United States)

    2011-10-10T23:59:59.000Z

    Core-accretion planet formation begins in protoplanetary disks with the growth of small, interstellar medium dust grains into larger particles. The progress of grain growth, which can be quantified using 10 {mu}m silicate spectroscopy, has broad implications for the final products of planet formation. Previous studies have attempted to correlate stellar and disk properties with the 10 {mu}m silicate feature in an effort to determine which stars are efficient at grain growth. Thus far there does not appear to be a dominant correlated parameter. In this paper, we use spatially resolved adaptive optics spectroscopy of nine T Tauri binaries as tight as 0.''25 to determine if basic properties shared between binary stars, such as age, composition, and formation history, have an effect on dust grain evolution. We find with 90%-95% confidence that the silicate feature equivalent widths of binaries are more similar than those of randomly paired single stars, implying that shared properties do play an important role in dust grain evolution. At lower statistical significance, we find with 82% confidence that the secondary has a more prominent silicate emission feature (i.e., smaller grains) than the primary. If confirmed by larger surveys, this would imply that spectral type and/or binarity are important factors in dust grain evolution.

  20. Competition among different height genotypes of grain sorghum hybrids

    E-Print Network [OSTI]

    Miller, Frederick Robert

    1965-01-01T23:59:59.000Z

    of differences from check for Temple (test 3), 45 Summary of differences from check for Temple (test 4). 46 vii LIST OF FIGURES Figures Page Deviations of treatments from the mean yield of grain in pounds per acre for the 3x3 hybrids over- all locations... Deviations of treatments from the mean yield of grain in pounds per acre for the 3x4 hybrids over- all locations 18 Deviations of treatments from the mean yield of grain in pounds per acre for the 4x4 hy'bride over- all locations Deviations of treatments...

  1. Profitable Small Grain Production In the Texas Gulf Coast.

    E-Print Network [OSTI]

    Miller, Travis D.; Livingston, Steve

    1987-01-01T23:59:59.000Z

    grains. Oats provides a greater forage yield than wheat but is considerably more sensitive to winter kill. Occasionally all top growth is lost in one abnormaJIy cold period. The forage provided by small grains is quite nutritious, with protein...TDOC Z TA24S.7 8873 NO.1S87 Texas Agricultural Extension Service LIBRARY SEP 2 7 1988 a~ A&M Univers' Profitable Small Grain Production In The Texas Gulf Coast 8-1587 Texas Agricultural Extension Service. Zerle L. Carpenter, Director...

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

    DOE Patents [OSTI]

    Rosecrans, P.M.

    1984-08-01T23:59:59.000Z

    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.

  3. Generalizations of the Störmer Problem for Dust Grain Orbits

    E-Print Network [OSTI]

    H. R. Dullin; M. Horányi; J. E. Howard

    2001-04-24T23:59:59.000Z

    We consider the generalized St\\"ormer Problem that includes the electromagnetic and gravitational forces on a charged dust grain near a planet. For dust grains a typical charge to mass ratio is such that neither force can be neglected. Including the gravitational force gives rise to stable circular orbits that encircle that plane entirely above/below the equatorial plane. The effects of the different forces are discussed in detail. A modified 3rd Kepler's law is found and analyzed for dust grains.

  4. On interaction of large dust grains with fusion plasma

    SciTech Connect (OSTI)

    Krasheninnikov, S. I.; Smirnov, R. D. [University of California at San Diego, La Jolla, California 92093 (United States)

    2009-11-15T23:59:59.000Z

    So far the models used to study dust grain-plasma interactions in fusion plasmas neglect the effects of dust material vapor, which is always present around dust in rather hot and dense edge plasma environment in fusion devices. However, when the vapor density and/or the amount of ionized vapor atoms become large enough, they can alter the grain-plasma interactions. Somewhat similar processes occur during pellet injection in fusion plasma. In this brief communication the applicability limits of the models ignoring vapor effects in grain-plasma interactions are obtained.

  5. Coarse-graining DNA for simulations of DNA nanotechnology

    E-Print Network [OSTI]

    Doye, Jonathan P K; Louis, Ard A; Romano, Flavio; Sulc, Petr; Matek, Christian; Snodin, Benedict E K; Rovigatti, Lorenzo; Schreck, John S; Harrison, Ryan M; Smith, William P J

    2013-01-01T23:59:59.000Z

    To simulate long time and length scale processes involving DNA it is necessary to use a coarse-grained description. Here we provide an overview of different approaches to such coarse graining, focussing on those at the nucleotide level that allow the self-assembly processes associated with DNA nanotechnology to be studied. OxDNA, our recently-developed coarse-grained DNA model, is particularly suited to this task, and has opened up this field to systematic study by simulations. We illustrate some of the range of DNA nanotechnology systems to which the model is being applied, as well as the insights it can provide into fundamental biophysical properties of DNA.

  6. Grain growth behavior and high-temperature high-strain-rate tensile ductility of iridium alloy DOP-26

    SciTech Connect (OSTI)

    McKamey, C.G.; Gubbi, A.N.; Lin, Y.; Cohron, J.W.; Lee, E.H.; George, E.P.

    1998-04-01T23:59:59.000Z

    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 new-process iridium-based DOP-26 alloy used for the Cassini space mission. This alloy was developed at Oak Ridge National Laboratory (ORNL) in the early 1980`s and is currently used by 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. Included within this report are data generated on grain growth in vacuum or low-pressure oxygen environments; a comparison of grain growth in vacuum of the clad vent set cup material with sheet material; effect of grain size, test temperature, and oxygen exposure on high-temperature high-strain-rate tensile ductility; and grain growth in vacuum and high-temperature high-strain-rate tensile ductility of welded DOP-26. The data for the new-process material is compared to available old-process data.

  7. The Composition of Interstellar Grains Toward Zeta Ophiuchi: Constraining the Elemental Budget Near the Diffuse-Dense Cloud Transition

    E-Print Network [OSTI]

    Poteet, Charles A; Draine, Bruce T

    2015-01-01T23:59:59.000Z

    We investigate the composition of interstellar grains along the line of sight toward Zeta Ophiuchi, a well-studied environment near the diffuse-dense cloud transition. A spectral decomposition analysis of the solid-state absorbers is performed using archival spectroscopic observations from the Spitzer Space Telescope and Infrared Space Observatory. We find strong evidence for the presence of sub-micron-sized amorphous silicate grains, principally comprised of olivine-like composition, with no convincing evidence of H2O ice mantles. However, tentative evidence for thick H2O ice mantles on large (a ~ 2.8 microns) grains is presented. Solid-state abundances of elemental Mg, Si, Fe, and O are inferred from our analysis and compared to standard reference abundances. We find that nearly all of elemental Mg and Si along the line of sight are present in amorphous silicate grains, while a substantial fraction of elemental Fe resides in compounds other than silicates. Moreover, we find that the total abundance of eleme...

  8. The Influence of Particle Size on Infrared Reflectance Spectra

    SciTech Connect (OSTI)

    Myers, Tanya L.; Brauer, Carolyn S.; Su, Yin-Fong; Blake, Thomas A.; Johnson, Timothy J.; Richardson, Robert L.

    2014-06-13T23:59:59.000Z

    Reflectance spectra of solids are influenced by the absorption coefficient as well as the particle size and morphology. In the infrared, spectral features may be observed as either maxima or minima: in general, the upward-going peaks in the reflectance spectrum result from surface scattering, which are rays that have reflected from the surface without penetration, whereas downward-going peaks result from either absorption or volume scattering, i.e. rays that have penetrated into the sample or refracted into the sample interior and are not reflected. The light signal reflected from solids usually encompasses all these effects which include dependencies on particle size, morphology and sample density. This paper measures the reflectance spectra in the 1.3 – 16 micron range for various bulk materials that have a combination of strong and weak absorption bands in order to understand the effects on the spectral features as a function of the mean grain size of the sample. The bulk materials were ground with a mortar and pestle and then sieved to separate the samples into various size fractions: 0-45, 45-90, 90-180, 180-250, 250-500, and >500 microns. The directional-hemispherical spectra were recorded using a Fourier transform infrared spectrometer equipped with an integrating sphere to measure the reflectance for all of the particle-size fractions. We have studied both organic and inorganic materials, but this paper focuses on inorganic salts, NaNO3 in particular. Our studies clearly show that particle size has an enormous influence on the measured reflectance spectra for bulk materials and that successful identification requires sufficient representative reflectance data so as to include the particle size(s) of interest. Origins of the effects are discussed.

  9. air-borne dust conditions: Topics by E-print Network

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

    grains. Based on numerical calculations of coagulation starting from the typical grain size distribution in the diffuse interstellar medium, we obtain a conservative lower limit...

  10. alignment probing grain: Topics by E-print Network

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

    grains, and hence the elemental abundance, is constrained from the reddening versus hydrogen column density, E(B-V)NH. If we take the solar elemental abundance as a standard...

  11. Grain boundary relaxation strengthening of nanocrystalline Ni–W alloys

    E-Print Network [OSTI]

    Rupert, Timothy J.

    The hardening effect caused by the relaxation of nonequilibrium grain boundary structure has been explored in nanocrystalline Ni–W alloys. First, the kinetics of relaxation hardening are studied, showing that higher annealing ...

  12. Thermodynamics of microstructure evolution: grain growth Victor L. Berdichevsky

    E-Print Network [OSTI]

    Berdichevsky, Victor

    Thermodynamics of microstructure evolution: grain growth Victor L. Berdichevsky Mechanical thermodynamic parameters, entropy of microstructure and temperature of microstruc- ture. It was claimed that there is "one more law of thermodynamics": entropy of microstructure must decay in isolated thermodynamic stable

  13. Study of grain compositions in comet Levy 1990XX

    E-Print Network [OSTI]

    H. S. Das; R. Bhattacharjee; B. K. Sinha; A. K. Sen

    2007-05-22T23:59:59.000Z

    In the present work, the non-spherical dust grain characteristics of comet Levy 1990XX with different silicate grain compositions (both pyroxene and olivine) are studied using the T-matrix method. Considering amorphous pyroxene grain (Mg$_x$Fe$_{1-x}$SiO$_3$) with $x$ (= 0.4, 0.5, 0.6, 0.7, 0.8, 0.95, 1) and amorphous olivine grain (Mg$_{2y}$Fe$_{2-2y}$SiO$_4$) with $y$ (= 0.4, 0.5) (Dorschner et al. 1995), the observed polarization data of comet Levy1990XX are analyzed using the T-matrix code at $\\lambda$ = 0.485 $\\mu m$.

  14. Grain Boundary Structure Effects on Intergranular Stress Corrosion Cracking of

    E-Print Network [OSTI]

    Olson, Tamara

    Grain Boundary Structure Effects on Intergranular Stress Corrosion Cracking of Alloy X­750 Y. Pan B­of­freedom) and correlations with intergranular stress corrosion cracking observed in Alloy X­750. Orientation imaging

  15. Deadlock-free fine-grained thread migration

    E-Print Network [OSTI]

    Cho, Myong Hyon

    Several recent studies have proposed fine-grained, hardware-level thread migration in multicores as a solution to power, reliability, and memory coherence problems. The need for fast thread migration has been well documented, ...

  16. On-Farm Storage and Disposal of Sorghum Grain.

    E-Print Network [OSTI]

    Brown, Charles W.; Moore, Clarence A.

    1963-01-01T23:59:59.000Z

    APRIL 1963 ON-FARM - STORAGE AND DISPOSAL OF SORGHUM GRAIN -- THE AGRICULTURAL AND MECHANICAL COLLEGE OF TEXAS TEXAS AGRICULTURAL EXPERIMENT STATION R. E. PATTERSON. DIRECTOR. COLLEGE ST+TION, TEXAS IN COOPERATION WITH THE U. S. DEPARTMENT... of its relative feeding value, an increasing number of livestock on feed, increases in concentrates fed per animal unit, a favorable price relative to other feed grains and gains in exports to foreign markets. Off-farm storage space in Texas...

  17. Systems simulation of oil additives to grain at terminal elevators

    E-Print Network [OSTI]

    Goforth, Kerry James

    1985-01-01T23:59:59.000Z

    SYSTEMS SIMULATION OF OIL ADDITIVES TO GRAIN AT TERMINAL ELEVATORS A Thesis by Kerry James Goforth Submitted to the Graduate College of Texas A8M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May... 1985 Major Subject: Agricultural Engineering SYSTEMS SIMULATION OF OIL ADDITIVES TO GRAIN AT TERMINAL ELEVATORS A Thesis by KERRY J. GOFORTH Approved as to style and content by: Calvin B. Parne 1, Jr. (Chairman of Committee) tto R. Kunze...

  18. Thermal conductivity and specific heat of sorghum grain

    E-Print Network [OSTI]

    Miller, Clinton Frank

    1963-01-01T23:59:59.000Z

    Formation of Test Canister Ice Jacket ~ Sealing Test Canister in Calorimeter. . 43 44 Testing of Samples. Initial Calorimeter Observations. 49 Insertion of Grain Samples into Calorimeter. . . . 50 Final Test Observations Processing of Data. 54... to Contain the Grain Sample 38 for the Determination of Specific Heat 39 12. Top View of Calorimeter. 40 13. Galvanized Iron Cylinder Used to Form the Ice Jacket Around the Test Canister 42 VIII Figures 14. Clamping Device Used to Hold Test Canister...

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

    DOE Patents [OSTI]

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

    1990-01-01T23:59:59.000Z

    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.

  20. Measurements of grain boundary properties in nanocrystalline ceramics

    SciTech Connect (OSTI)

    Chiang, Y.M.; Smyth, I.P.; Terwilliger, C.D. (Massachusetts Inst. of Tech., Cambridge, MA (USA). Dept. of Materials Science and Engineering); Petuskey, W.T. (Arizona State Univ., Tempe, AZ (USA). Dept. of Chemistry); Eastman, J.A. (Argonne National Lab., IL (USA))

    1990-11-01T23:59:59.000Z

    The advent of nanocrystalline ceramics prepared by a variety of solution-chemical and vapor deposition methods offers a unique opportunity for the determination grain boundary properties by bulk'' thermodynamic methods. In this paper we discuss results from two types of measurements on model nanocrystalline ceramics. The first is a solution thermodynamic measurement of the activity of nanocrystalline SiC in polycarbosilane-derived silicon carbide fibers (Nicalon). Structural studies have shown that Nicalon consists of well-ordered cubic ({beta} or 3C polytype) SiC grains separated by a very thin grain boundary layer (<1 nm thick) containing the oxygen. The physical properties and chemical reactivity of these fibers are distinctly different from that of bulk silicon carbide. Direct measurement of the alloy composition and analysis of the microstructure has allowed the dissolution reaction to be identified and a lower limit for the SiC activity in the nanocrystalline form to be determined. A second method of measuring grain boundary properties we have investigated for nanocrystalline Si and TiO{sub 2} is high temperature calorimetry. In appropriate samples the grain boundary enthalpy can be measured through the heat evolved during grain growth. Preliminary results on nanocrystalline Si prepared by the recrystallization of amorphous evaporated films and on TiO{sub 2} condensed from the vapor phase are discussed. 29 refs., 3 figs., 1 tab.

  1. Wide size range fast integrated mobility spectrometer

    DOE Patents [OSTI]

    Wang, Jian

    2013-10-29T23:59:59.000Z

    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.

  2. 1999 Commercial Buildings Characteristics--Building Size

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National and Regional Data; Row: NAICS8) Distribution Category UC-950 Cost and Quality of Fuels for Electric Utility Plants 1998 TablesSize of

  3. Effect of build geometry on the ?-grain structure and texture in additive manufacture of Ti-6Al-4V by selective electron beam melting

    SciTech Connect (OSTI)

    Antonysamy, A.A., E-mail: alphons.antonysamy@GKNAerospace.com [Additive Manufacturing Centre, GKN Aerospace, P.O. Box 500, Golf Course Lane, Filton, BS34 9 AU (United Kingdom); Meyer, J., E-mail: jonathan.meyer@eads.com [EADS Innovation Works, 20A1 Building, Golf Course Lane, Filton, Bristol, BS997AR (United Kingdom); Prangnell, P.B., E-mail: philip.prangnell@manchester.ac.uk [School of Materials, University of Manchester, Manchester M13 9PL (United Kingdom)

    2013-10-15T23:59:59.000Z

    With titanium alloys, the solidification conditions in Additive Manufacturing (AM) frequently lead to coarse columnar ?-grain structures. The effect of geometry on the variability in the grain structure and texture, seen in Ti-6Al-4V alloy components produced by Selective Electron Beam Melting (SEBM), has been investigated. Reconstruction of the primary ?-phase, from ?-phase EBSD data, has confirmed that in bulk sections where in-fill “hatching” is employed growth selection favours columnar grains aligned with an <001> {sub ?} direction normal to the deposited powder layers; this results in a coarse ?-grain structure with a strong < 001 > {sub ?} fibre texture (up 8 x random) that can oscillate between a near random distribution around the fibre axis and cube reinforcement with build height. It is proposed that this behaviour is related to the highly elongated melt pool and the raster directions alternating between two orthogonal directions every layer, which on average favours grains with cube alignment. In contrast, the outline, or “contour”, pass produces a distinctly different grain structure and texture resulting in a skin layer on wall surfaces, where nucleation occurs off the surrounding powder and growth follows the curved surface of the melt pool. This structure becomes increasingly important in thin sections. Local heterogeneities have also been found within different section transitions, resulting from the growth of skin grain structures into thicker sections. Texture simulations have shown that the far weaker ?-texture (? 3 x random), seen in the final product, arises from transformation on cooling occurring with a near random distribution of ?-plates across the 12 variants possible from the Burgers relationship. - Highlights: • Distinctly different skin and bulk structures are produced by the contour and hatching passes. • Bulk sections contain coarse ?-grains with a < 001 > fibre texture in the build direction. • This oscillates between a random distribution around the axis and cube reinforcement. • In the skin layer nucleation occurs off the surrounding powder bed and growth occurs inwards. • Simulations show that a weak ?-texture results from a random distribution across habit variants.

  4. Interactions of mobile helium clusters with surfaces and grain boundaries of plasma-exposed tungsten

    SciTech Connect (OSTI)

    Hu, Lin; Maroudas, Dimitrios, E-mail: maroudas@ecs.umass.edu [Department of Chemical Engineering, University of Massachusetts, Amherst, Massachusetts 01003-9303 (United States); Hammond, Karl D.; Wirth, Brian D. [Department of Nuclear Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States)

    2014-05-07T23:59:59.000Z

    We report results of atomistic computations for the interactions of small mobile helium clusters (He{sub n}) with free surfaces and grain boundaries (GBs) in tungsten toward development of continuum drift-diffusion-reaction models for the dynamics of mobile helium clusters in plasma-exposed tungsten. Molecular-statics (MS) simulations based on reliable many-body interatomic potentials are carried out for He{sub n} (1???n???7) clusters near sinks to obtain the potential energy profiles of the He{sub n} clusters as a function of the clusters' center-of-mass distance from a sink. Sinks investigated include surfaces, GBs, and regions in the vicinity of junctions where GBs intersect free surfaces. Elastic interaction potentials based on elastic inclusion theory provide an excellent description of the MS results for the cluster-sink interactions. The key parameter in the elastic models is the sink segregation strength, which is found to increase with increasing cluster size. Such cluster-sink interactions are responsible for the migration of small helium clusters by drift and for helium segregation on surfaces and grain boundaries in tungsten. Such helium segregation on sinks is observed in large-scale molecular-dynamics simulations of helium aggregation in model polycrystalline tungsten at 933?K upon helium implantation.

  5. Study of Etching Pits in a Large-grain Single Cell Bulk Niobium Cavity

    SciTech Connect (OSTI)

    Zhao, Xin [William and Mary College; Ciovati, Gianluigi [JLAB; Reece, Charles E. [JLAB; Wu, Andy T. [JLAB

    2009-11-01T23:59:59.000Z

    Performance of SRF cavities are limited by non-linear localized effects. The variation of local material characters between "hot" and "cold" spots is thus of intense interest. Such locations were identified in a BCP-etched large-grain single-cell cavity and removed for examination by high resolution electron microscopy (SEM), electron-back scattering diffraction microscopy (EBSD), optical microscopy, and 3D profilometry. Pits with clearly discernable crystal facets were observed in both "hotspot" and "coldspot" specimens. The pits were found in-grain, at bi-crystal boundaries, and on tri-crystal junctions. They are interpreted as etch pits induced by surface crystal defects (e.g. dislocations). All "coldspots" examined had qualitatively low density of etching pits or very shallow tri-crystal boundary junction. EBSD revealed crystal structure surrounding the pits via crystal phase orientation mapping, while 3D profilometry gave information on the depth and size of the pits. In addition, a survey of the samples by energy dispersive X-ray analysis (EDX) did not show any significant contamination of the samples surface.

  6. 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...

  7. Silicate Emission Profiles from Low-Mass Protostellar Disks in the Orion Nebula: Evidence for Growth and Thermal Processing of Grains

    E-Print Network [OSTI]

    R. Y. Shuping; Marc Kassis; Mark Morris; Nathan Smith; John Bally

    2006-05-05T23:59:59.000Z

    We present 8--13 micron low resolution spectra (R~100) of 8 low-mass protostellar objects ("proplyds") in the Orion Nebula using the Long Wavelength Spectrometer (LWS) at the W. M. Keck Observatory. All but one of the sources in our sample show strong circumstellar silicate emission, with profiles that are qualitatively similar to those seen in some T Tauri and Herbig Ae/Be stars. The silicate profile in all cases is significantly flattened compared to the profile for typical interstellar dust, suggesting that the dominant emitting grains are significantly larger than those found in the interstellar medium. The 11.3-to-9.8 micron flux ratio--often used as an indicator of grain growth--is in the 0.8 to 1.0 range for all of our targets, indicating that the typical grain size is around a few microns in the surface layers of the attendant circumstellar disk for each object. Furthermore, the silicate profiles show some evidence of crystalline features, as seen in other young stellar objects. The results of our analysis show that the grains in the photoevaporating protostellar disks of Orion have undergone significant growth and perhaps some annealing, suggesting that grain evolution for these objects is not qualitatively different from other young stellar objects.

  8. Manufacture and properties of continuous grain flow crankshafts for locomotive and power generation diesel engines

    SciTech Connect (OSTI)

    Antos, D.J.; Nisbett, E.G. [National Forge Co., Irvine, PA (United States)

    1997-12-31T23:59:59.000Z

    The bulk of the large crankshaft production volume is associated with the medium speed diesel engine market. These engines have seen intense development to obtain higher power outputs without change in the physical size of the crankshaft and at the same time there has been continuing pressure to reduce costs. Fatigue and bearing normal wear are the major technical hurdles that threaten the crankshaft life, and measures for dealing with these issues are described. Continuous grain flow (CGF) crankshafts are responsible for the continued integrity of these enhanced power output engines and the production of these crankshafts is described. Comparisons are made with the older slab forging crankshaft production method. The demand for the medium speed diesel engine and its natural gas derivative is strong and supports an aggressive engine building industry serving locomotive, marine and power generation markets. This demand in turn relies on practical national standards that serve the needs of the engine builder, material supplier and the end user.

  9. Modeling radiation damage near grain boundary in helium-doped ?-iron

    SciTech Connect (OSTI)

    Xu, C. P.; Liu, X.-Y; Gao, Fei; Li, Y. H.; Wang, Y. Q.

    2014-08-01T23:59:59.000Z

    Molecular dynamics (MD) simulations are performed to investigate how ?3<110> (121) symmetric tilt grain boundary (GB) affects point defects and defect clusters in He-doped ?-iron at 300 K in picosecond time scales. Molecular statics calculations are also performed and show that the formation energy is reduced in the GB, and the GB acts as a good sink for point defects especially for interstitial He and self-interstitial atoms (SIAs). It is observed that the average size of HenVm (m>n) clusters becomes smaller in the GB-containing Fe system. It is also found that the number of HenV (n=2, 3) clusters in the GB region decreases, while the number of the HeV clusters increases. The GBs loaded with substitutional or interstitial helium atoms are found to facilitate the growth of helium clusters in the GB region.

  10. Does semantic size affect size constancy scaling using lexical stimuli? 

    E-Print Network [OSTI]

    Beveridge, Madeleine

    2010-11-24T23:59:59.000Z

    Binocular disparity allows us to perceive the world in 3-dimensions through the process of stereopsis. In this study, we used binocular disparity to induce the size constancy illusion in lexical stimuli. 47 undergraduate ...

  11. METER-SIZED MOONLET POPULATION IN SATURN'S C RING AND CASSINI DIVISION

    SciTech Connect (OSTI)

    Baillie, Kevin; Colwell, Joshua E. [Department of Physics, University of Central Florida, Orlando, FL 32816-2385 (United States); Esposito, Larry W. [Laboratory for Atmospheric and Space Physics, University of Colorado at Boulder, 392 UCB, Boulder, CO 80309-0392 (United States); Lewis, Mark C., E-mail: kevin.baillie@cea.fr [Department of Computer Science, Trinity University, One Trinity Place, San Antonio, TX 78212-7200 (United States)

    2013-06-01T23:59:59.000Z

    Stellar occultations observed by the Cassini Ultraviolet Imaging Spectrograph reveal the presence of transparent holes a few meters to a few tens of meters in radial extent in otherwise optically thick regions of the C ring and the Cassini Division. We attribute the holes to gravitational disturbances generated by a population of {approx}10 m boulders in the rings that is intermediate in size between the background ring particle size distribution and the previously observed {approx}100 m propeller moonlets in the A ring. The size distribution of these boulders is described by a shallower power-law than the one that describes the ring particle size distribution. The number and size distribution of these boulders could be explained by limited accretion processes deep within Saturn's Roche zone.

  12. Impulsive Spot Heating and Thermal Explosion of Interstellar Grains Revisited

    E-Print Network [OSTI]

    Ivlev, A V; Vasyunin, A; Caselli, P

    2015-01-01T23:59:59.000Z

    The problem of impulsive heating of dust grains in cold, dense interstellar clouds is revisited theoretically, with the aim to better understand leading mechanisms of the explosive desorption of icy mantles. It is rigorously shown that if the heating of a reactive medium occurs within a sufficiently localized spot (e.g., heating of mantles by cosmic rays), then the subsequent thermal evolution is characterized by a single dimensionless number $\\lambda$. This number identifies a bifurcation between two distinct regimes: When $\\lambda$ exceeds a critical value (threshold), the heat equation exhibits the explosive solution, i.e., the thermal (chemical) explosion is triggered. Otherwise, thermal diffusion causes the deposited heat to spread over the entire grain -- this regime is commonly known as the whole-grain heating. The theory allows us to find a critical combination of the physical parameters that govern the explosion of icy mantles due to impulsive spot heating. In particular, the calculations suggest tha...

  13. Lattice complexity and fine graining of symbolic sequence

    E-Print Network [OSTI]

    Da-Guan Ke; Hong Zhang; Qin-Ye Tong

    2008-04-05T23:59:59.000Z

    A new complexity measure named as Lattice Complexity is presented for finite symbolic sequences. This measure is based on the symbolic dynamics of one-dimensional iterative maps and Lempel-Ziv Complexity. To make Lattice Complexity distinguishable from Lempel-Ziv Complexity, an approach called fine-graining process is also proposed. When the control parameter fine-graining order is small enough, the two measures are almost equal. While the order increases, the difference between the two measures becomes more and more significant. Applying Lattice Complexity to logistic map with a proper order, we find that the sequences that are regarded as complex are roughly at the edges of chaotic regions. Further derived properties of the two measures concerning the fine-graining process are also discussed.

  14. Effect of grain on silage characteristics for ruminants

    E-Print Network [OSTI]

    Groves, William Grady

    1977-01-01T23:59:59.000Z

    . pared the nutritional value of Oro-t, a grain type sorghum, and Fs-lb and Fs-la, two forage type grain sorghums (Bupp, 1973; I:upp, 1975; Spiegel, 1975; and Tolbert et al. , 1975). Tol'oert et al. (1975) indicated that dry matter digestibilities...;ver . enerally higher for she p fed Fs-lb, whereas nitrogen digestibilities and re- tention. ", -er higher f' or sheep fed Oro-t sila=es. They a' so discovered that increasin" head to . ,tover rations increas d d ~ matter digestibi'ities up to a 1:1 ratio...

  15. Dry, reconstituted, and early harvested sorghum grain for finishing cattle

    E-Print Network [OSTI]

    Parrett, Ned Albert

    1968-01-01T23:59:59.000Z

    upon a number of, factors such as diameter& length and revolving speed of the auger. A steady flow of dry grain and water must be maintained into the mixing auger in order to obtain proper and uniform water application. For a given installation... commenced. Reconstituting was accomplish . d by making use of a 70-foot auger conveyor, nine inches in diameter (Figure li. Water was added by metering into a one inch line located above the auger. Grain flow rate was regulated by use of a variable...

  16. Production and Management of Small Grains for Forage.

    E-Print Network [OSTI]

    Holt, E. C.; Norris, M. J.; Lancaster, J. A.

    1969-01-01T23:59:59.000Z

    . Rainfall excessive for maximum gro\\ytb may occur, especially in the coastal area. Reduced sunlight energy during the ~~inttr months apparently limits growth of small grain. Planting rates and methods do not seem to a1tt.r this response significantly... that the tillering ( zcteristic of small grains tends to comper For lower plant populations whether from 1( seeding rates or wider row spacings Treatment Pounds of Row spacing, Pounds of air-dry forage ~nches seed per acre per acre The growth of winter...

  17. Effects of grain deterioration on sorghum food quality

    E-Print Network [OSTI]

    Domanski, Cristian Estanislao

    1983-01-01T23:59:59.000Z

    and Bechtel 1978). Storage fungi common on grains grow most rapidly at about 30-32 C, and their growth rate decreases as temperature decreases. Qasem and Christensen (1960), working with samples of maize stored in the laboratory at moisture contents of 16... deteriorated grain was set at about 18%, which allowed fungal growth but not sprouting. Under field conditions, the moisture content is much higher, after a rain or dew, for example. TADI 1. 2 Effeii of Cruin Deterroraciun on tlir I'hysicai amd Chemical...

  18. Requirements for Grain Sorghum Irrigation on the High Plains.

    E-Print Network [OSTI]

    Thaxton, E. L. Jr.; Swanson, Norris P.

    1956-01-01T23:59:59.000Z

    and Recommendations Irrigation research was conducted with grain sorghum on the optimum use of underground water ' resources at the Amarillo and Lubbock Experiment Stations and on off-station plots during the past several years. Highest returns in pounds of grain... per inch of water are received when 'brain sorghum is sup I plied with adequate moisture from planting to the soft dough stage. I High-moisture levels are the most profitable; if the irrigation water supply becomes inadequate, the acreage to which...

  19. Economic Considerations in Storing Grain Sorghum in Central Texas.

    E-Print Network [OSTI]

    Moore, Clarence A.

    1958-01-01T23:59:59.000Z

    price increase. However, the CCC locm-price support program tends to "iron-out" the seasonal increases in price on which returns to storage depend in a "free" market operation. With the present price support program, most producers are interested... in whether to sell at harvest or store under CCC loan. If the net price a producer can obtain by forfeiting the grain is more than the harvest market price, it pays to put grain in storage under CCC loan. If not, he will be taking a chance of loss...

  20. Extremal sizes of subspace partitions

    E-Print Network [OSTI]

    Heden, Olof; Nastase, Esmeralda; Sissokho, Papa

    2011-01-01T23:59:59.000Z

    A subspace partition $\\Pi$ of $V=V(n,q)$ is a collection of subspaces of $V$ such that each 1-dimensional subspace of $V$ is in exactly one subspace of $\\Pi$. The size of $\\Pi$ is the number of its subspaces. Let $\\sigma_q(n,t)$ denote the minimum size of a subspace partition of $V$ in which the largest subspace has dimension $t$, and let $\\rho_q(n,t)$ denote the maximum size of a subspace partition of $V$ in which the smallest subspace has dimension $t$. In this paper, we determine the values of $\\sigma_q(n,t)$ and $\\rho_q(n,t)$ for all positive integers $n$ and $t$. Furthermore, we prove that if $n\\geq 2t$, then the minimum size of a maximal partial $t$-spread in $V(n+t-1,q)$ is $\\sigma_q(n,t)$.

  1. Coarse-grained electrostatic interactions of coronene: Towards the crystalline phase

    E-Print Network [OSTI]

    Thomas Heinemann; Karol Palczynski; Joachim Dzubiella; Sabine H. L. Klapp

    2015-06-05T23:59:59.000Z

    In this article we present and compare two different, coarse-grained approaches to model electrostatic interactions of anisotropic organic molecules, specifically coronene. Our study is an extension of previous work [J. Chem. Phys. 141, 214110 (2014)] where we proposed, based on a systematic coarse-graining procedure starting from the atomistic level, an anisotropic effective (Gay-Berne-like) potential capable of describing van-der-Waals contributions to the interaction energy. To take into account electrostatics, we introduce, first, a linear quadrupole moment along the symmetry axis of the coronene disk. The second approach takes into account the fact that the partial charges within the molecules are distributed in a ring-like fashion. We then reparametrize the effective Gay-Berne-like potential such that it matches, at short distances, the ring-ring potential. To investigate the validity of these two approaches, we perform many-particle Molecular Dynamics (MD) simulations, focusing on the crystalline phase (karpatite) where electrostatic interaction effects are expected to be particularly relevant. Specifically, we investigate various structural parameters as well as the melting transition. We find that the second approach yields consistent results with those from experiments despite the fact that the underlying potential decays with the wrong distance dependence at large molecule separations. Our strategy can be transferred to a broader class of molecules, such as benzene or hexabenzocoronene.

  2. Distributed DBMS Introduction

    E-Print Network [OSTI]

    Chen, Yangjun

    Distributed DBMS Outline Introduction What is a distributed DBMS Problems Current state-of-affairs Background Distributed DBMS Architecture Distributed Database Design Semantic Data Control Distributed Query Processing Distributed Transaction Management Parallel Database Systems Distributed Object DBMS

  3. Children's Clothes - Size and Selection.

    E-Print Network [OSTI]

    Vanderpoorten, Ann; Kerbel, Claudia

    1980-01-01T23:59:59.000Z

    Tooe ZTA245.7 8-1303 B873 no ? \\'3J~3L-~=============i1 ? ? ? CHILDREN'S CLOTHES, SIZE AND SELECTION ? ~========================~ Texas Agricultural Extension Service. The Texas A&M University System. Daniel C. pfannstiel, Director.... College Station, Texas ," ? (BIaBk Pa,ge in O'rigjaal Bulletinl ' / I' j '. ":SIZE AND SELECTION Ann Vanderpoorten and Claudia Kerbel* Preschool and school-age children have special...

  4. Normal Distribution

    E-Print Network [OSTI]

    User

    NORMAL DlSTRlBUTION TABLE. Entries represent the area under the standardized normal distribution from -w to z, Pr(Z

  5. Role of Crystallographic Texture and Grain Size on Low Temperature Deformation and Formability of a Mg Alloy

    E-Print Network [OSTI]

    Dogan, Ebubekir

    2014-12-12T23:59:59.000Z

    Interest in Mg alloys has significantly increased in recent years for weight-critical applications. However, Mg alloys show low strength and poor low temperature formability, due to the limited available slip systems and the strong final texture...

  6. Investigation of the sheath formation in a dusty plasma containing energetic electrons and nano-size dust grains

    SciTech Connect (OSTI)

    Foroutan, G.; Akhoundi, A. [Physics Department, Faculty of Science and Nanostructure Material Research Center, Sahand University of Technology, 51335-1996 Tabriz (Iran, Islamic Republic of)

    2012-10-15T23:59:59.000Z

    Numerical simulations of the stationary multi-fluid equations are used to study the structure of a dusty plasma sheath in the presence of a beam of energetic electrons. It is found that even a small number of energetic electrons can strongly modify the sheath parameters, specially the sheath thickness. Depending on the magnitude of the beam flux, two different regimes of sheath thickness can be recognized; At small beam fluxes, the sheath is in the regime of thin sheath and its thickness grows linearly with the beam flux. As the beam flux increases, at a certain beam energy or beam number density, the sheath demonstrates a sharp transition to the regime of thick sheath where the width is almost three times larger. The beam parameters corresponding to the transition between the two regimes depend on the parameters of the background plasma. The beam transition energy increases with the electron temperature and dust number density while decreases with the dust radius. On the other hand, the beam transition number density is a non-monotonic function of the background plasma number density. The localization of dust particles above the substrate is intensified by the increase in the beam number density.

  7. Quasi-isentropic and shock compression of FCC and BCC metals : effects of grain size and stacking-fault energy

    E-Print Network [OSTI]

    Jarmakani, Hussam N.

    2008-01-01T23:59:59.000Z

    Compressed Copper-Aluminum Alloys, Met. Mat. Trans, 2007,of Copper and Copper-Aluminum Alloys, International Journalthe projectile (made of aluminum alloy D16T) and the sample

  8. Quasi-isentropic and shock compression of FCC and BCC metals : effects of grain size and stacking-fault energy

    E-Print Network [OSTI]

    Jarmakani, Hussam N.

    2008-01-01T23:59:59.000Z

    sliding under compression, which was identified as being due to a Mohr-Coulomb-like mechanism. As pressure

  9. The effect of WC grain size and cobalt content on properties and electrical discharge machining of WC-Co composites

    E-Print Network [OSTI]

    Tsai, Wei-Lung

    1988-01-01T23:59:59.000Z

    -Co composites (6% cobalt content) 108 116 LIST OF FIGURES Figure Tungsten-carbon phase diagram Ternary phase diagram of W-C-Co system (1400'C isothermal section) Pa, ge 3. Quasi-binary WC-Co diagram 4. Schematic diagram oi' the EDM 5. Schematic... spectra. of tungsten in WC-Co composite 11. EDS spectra of cobalt in WC-Co composite . 15 23 26 32 12. 14. 15. 16. Effect of cobalt content on the macrohardness of WC-Co composites Effect of cobalt content on the microhardness of WC...

  10. Conditions necessary for capillary hysteresis in porous media: Tests of grain-size and surface tension influences

    E-Print Network [OSTI]

    Tokunaga, Tetsu K.; Olson, Keith R.; Wan, Jiamin

    2004-01-01T23:59:59.000Z

    resaturate the gravel or sand pack. Like in the drainingtop of the pack. In coarser (? 7 mm) gravels, the starting

  11. Effects of grain size on the rate-dependent thermomechanical responses of nanostructured superelastic NiTi

    E-Print Network [OSTI]

    Sun, Qing-Ping

    in situ infrared thermography in the strain rate range from _e = 4 Ã? 10Ã?5 sÃ?1 to _e = 1 Ã? 10Ã?1 sÃ?1

  12. EFFECTS OF STRENGTH AND GRAIN SIZE ON NEAR-THRESHOLD FATIGUE CRACK GROWTH IN ULTRA-HIGH STRENGTH STEEL

    E-Print Network [OSTI]

    Ritchie, Robert O.

    2010-01-01T23:59:59.000Z

    Mechanical properties of 300-M steel. FI CUKE CAPT! ONS Fig.lIK) at R ~ (l.OS, for 300-M steel, qUC'IH:iwci and temperedcrack growth (lIKo) in 300-M steel, tesLed in air. Summary

  13. Quasi-isentropic and shock compression of FCC and BCC metals : effects of grain size and stacking-fault energy

    E-Print Network [OSTI]

    Jarmakani, Hussam N.

    2008-01-01T23:59:59.000Z

    the nickel electrolyte during electrodeposition to stabilizeelectrodeposition method given the relatively thick nc layer. Figure 4.15: As-prepared 30-50 nm nickel

  14. Critical events, entropy, and the grain boundary character distribution Materials Research Science and Engineering Center

    E-Print Network [OSTI]

    § Department of Mathematics, The University of Utah, Salt Lake City, UT 84112 D. Kinderlehrer,¶ R. Sharp, and S) or area (in 3D) of interface with a given lattice misorien- tation and normal. During the growth process to the interfacial energy density. In simulation, it is found that if the given energy density depends only

  15. Copyright (to be inserted by the publisher ) Crystallographic Distribution of Low Angle Grain Boundary Planes

    E-Print Network [OSTI]

    Rohrer, Gregory S.

    , Reymonta 25, 30-059 Krakow, Poland 3 Electrical and Computer Engineering Dept., Carnegie Mellon University. Based on the inverse correlation between these two quantities, we conclude that relatively low energy the dislocation density and the energy of the interface, we conclude that the total interfacial free energy

  16. Criteria for mixing rules application for inhomogeneous astrophysical grains

    E-Print Network [OSTI]

    Napoleon Maron; Olaf Maron

    2008-09-06T23:59:59.000Z

    The analysis presented in this paper verifies which of the mixing rules are best for real components of interstellar dust in possible wide range of wavelengths.The DDA method with elements of different components with various volume fractions has been used. We have considered 6 materials: ice, amorphous carbon, graphite, SiC, silicates and iron, and the following mixing rules: Maxwell-Garnett, Bruggeman, Looyenga, Hanay and Lichtenecker which must satisfy rigorous bounds. The porous materials have also been considered. We have assumed simplified spatial distribution, shape and size of inclusions. The criteria given by \\citet{draine1988} have been used to determine the range of wavelengths for the considered mixtures in order to calculate the ${\\rm Q_{ext}}$ using the DDA. From all chosen mixing rules for the examined materials in majority of cases (13 out of 20) the best results have been obtained using the Lichtenecker mixing rule. In 5 cases this rule is better for some volume fraction of inclusions.

  17. In vitro activity of sorghum non-tannin polyphenols against grain molding and weathering fungi

    E-Print Network [OSTI]

    Leungchaikul, Patcharin

    1982-01-01T23:59:59.000Z

    moniliforme (Castor 1981). Grain weather1ng 1s a colonizat1on of mature kernels by saprophytic field fungi such as Alternaria spp. The difference be- tween grain molding and weathering 1s not perfectly distinct and the fungi that cause grain molding can... also cause grain weathering. For example, C. lunata and F. moniliforme can 1nfect sorghum late in kernel development or after maturity and, therefore, cause grain weather1ng (Castor 1981) . Fungal infect1on of grain in the field and/or dur1ng...

  18. Microwave sintering of sol-gel derived abrasive grain

    DOE Patents [OSTI]

    Plovnick, Ross (St. Louis Park, MN); Celikkaya, Ahmet (Woodbury, MN); Blake, Rodger D. (Tuscon, AZ)

    1997-01-01T23:59:59.000Z

    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.

  19. FEA Simulations of Magnets with Grain Oriented Steel

    SciTech Connect (OSTI)

    Witte H.

    2012-08-06T23:59:59.000Z

    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.

  20. Grain Drill Metering Systems and the Need for Calibration

    E-Print Network [OSTI]

    Holland, Jeffrey

    Grain Drill Metering Systems and the Need for Calibration Purdue extension ABE-126-W Purdue down an average seed- ing rate. Calibration is often overlooked as a means of im- proving machine performance and controlling input costs. Calibration is simply the process of verifying the rate of delivery

  1. Magnetic Fields via Polarimetry: Progress of Grain Alignment Theory

    E-Print Network [OSTI]

    A. Lazarian

    2002-08-28T23:59:59.000Z

    Most astrophysical systems, e.g. stellar winds, the diffuse interstellar medium, molecular clouds, are magnetized with magnetic fields that influence almost all of their properties. One of the most informative techniques of magnetic field studies is based on the use of starlight polarization and polarized emission arising from aligned dust. How reliable the interpretation of the polarization maps in terms of magnetic fields is the issue that the grain alignment theory addresses. Although grain alignment is a problem of half a century standing, recent progress achieved in the field makes us believe that we are approaching the solution of this mystery. I review basic physical processes involved in grain alignment and discuss the niches for different alignment mechanisms. I show why mechanisms that were favored for decades do not look so promising right now, while the radiative torque mechanism ignored for more than 20 years looks so attractive. I define the observational tests and outline the circumstances when grain alignment theory predicts that new yet untapped information of magnetic field structure is available through polarimetry. In particular, I touch upon mapping magnetic fields in circumstellar regions, interplanetary space and in comet comae.

  2. Fine-Grained Power Management Using Process-level Profiling

    E-Print Network [OSTI]

    Shi, Weisong

    . To evaluate energy efficiency, the Green Grid group proposed the definition of power usage effectiveness (PUE between performance and energy consumption, fine-grained methods, such as process- level power management-aware decisions based on these information. In addition, we introduce a power-aware system module called Energy

  3. Presolar Silicate Grains: Constraints on Solar System Processes and

    E-Print Network [OSTI]

    Floss, Christine

    Presolar Silicate Grains: Constraints on Solar System Processes and Stellar Nucleosynthesis 63130, USA. (floss@wustl.edu) Presolar silicates are among the most abundant type of stardust and have. This is particularly true for presolar silicates, which are more susceptible to secondary processing than other, more

  4. Ratooning Grain Sorghum on the Texas Gulf Coast

    E-Print Network [OSTI]

    Livingston, Stephen; Coffman, Cloyce G.

    1997-01-03T23:59:59.000Z

    Sorghum has characteristics that make it able to regenerate the above-ground portion of the plant. These features allow producers to seek a second grain crop within the same growing year by preparing the old plants immediately after the removal...

  5. The Harrison Diffusion Kinetics Regimes in Solute Grain Boundary Diffusion

    SciTech Connect (OSTI)

    Belova, Irina [University of Newcastle, NSW, Australia; Fiedler, T [University of Newcastle, NSW, Australia; Kulkarni, Nagraj S [ORNL; Murch, Prof. Graeme [University of Newcastle, NSW, Australia

    2012-01-01T23:59:59.000Z

    Knowledge of the limits of the principal Harrison kinetics regimes (Type-A, B and C) for grain boundary diffusion is very important for the correct analysis of the depth profiles in a tracer diffusion experiment. These regimes for self-diffusion have been extensively studied in the past by making use of the phenomenological Lattice Monte Carlo (LMC) method with the result that the limits are now well established. The relationship of those self-diffusion limits to the corresponding ones for solute diffusion in the presence of solute segregation to the grain boundaries remains unclear. In the present study, the influence of solute segregation on the limits is investigated with the LMC method for the well-known parallel grain boundary slab model by showing the equivalence of two diffusion models. It is shown which diffusion parameters are useful for identifying the limits of the Harrison kinetics regimes for solute grain boundary diffusion. It is also shown how the measured segregation factor from the diffusion experiment in the Harrison Type-B kinetics regime may differ from the global segregation factor.

  6. mineral grains pore spaces Subsurface Geology and Resource Exploration

    E-Print Network [OSTI]

    Li, X. Rong

    mineral grains pore spaces Subsurface Geology and Resource Exploration Locating earth resources deals with the exploration for oil, which is important to Louisiana, the Gulf of Mexico area oil (petroleum) and natural gas, that are refined for use as fuels. When sediments are deposited

  7. Thermodynamics of Protein Folding from Coarse-Grained Models' Perspectives

    E-Print Network [OSTI]

    Janke, Wolfhard

    8 Thermodynamics of Protein Folding from Coarse-Grained Models' Perspectives Michael Bachmann applications. In this lecture, we focus on the anal- ysis of mesoscopic models for protein folding, aggregation for a more universal description of the notoriously difficult problem of protein fold- ing. In this approach

  8. January 2002 Wild Oat Control In Small Grains -2002

    E-Print Network [OSTI]

    Minnesota, University of

    January 2002 Wild Oat Control In Small Grains - 2002 Beverly R. Durgan Weed Scientist - University of Minnesota Good wild oat control with any herbicide requires proper timing of applications. Postemergence wild oat herbicides require application to wild oats and crops at precise leaf stages. Leaf number

  9. January 2006 Wild Oat Control In Small Grains -2006

    E-Print Network [OSTI]

    Minnesota, University of

    1 January 2006 Wild Oat Control In Small Grains - 2006 Beverly R. Durgan Weed Scientist - University of Minnesota Good wild oat control with any herbicide requires proper timing of applications. Postemergence wild oat herbicides require application to wild oats and crops at precise leaf stages. Leaf number

  10. On the Absorption and Emission Properties of Interstellar Grains

    E-Print Network [OSTI]

    Aigen Li

    2005-03-25T23:59:59.000Z

    Our current understanding of the absorption and emission properties of interstellar grains are reviewed. The constraints placed by the Kramers-Kronig relation on the wavelength-dependence and the maximum allowable quantity of the dust absorption are discussed. Comparisons of the opacities (mass absorption coefficients) derived from interstellar dust models with those directly estimated from observations are presented.

  11. Integrated loading rate determination for wastewater infiltration system sizing

    SciTech Connect (OSTI)

    Jenssen, P.D. (Norges Landbrukshoegskole, Aas (Norway). Centre for Soil and Environmental Research); Siegrist, R.L. (Oak Ridge National Lab., TN (United States))

    1991-01-01T23:59:59.000Z

    One of the principal parameters used in wastewater system design is the hydraulic loading rate. Historically the determination of the loading rate has been a straight forward process involving selection of a rate based on soil texture or water percolation rate. Research and experience over the past decade has provided additional insight into the complex processes occurring within wastewater-amended soil systems and has suggested the fallacy of this approach. A mean grain size vs. sorting (MESO) diagram constitutes a new basis for soil classification for wastewater infiltration system design. Crude characterization of the soil hydraulic properties is possible according to the MESO Diagram and loading rate as well as certain purification aspects can be assessed from the diagram. In this paper, an approach is described based on the MESO Diagram that integrates soil properties and wastewater pretreatment to yield a loading rate. 53 refs., 3 figs., 2 tabs.

  12. Large amplitude dust-acoustic solitary waves in electron-positron-ion plasma with dust grains

    SciTech Connect (OSTI)

    Esfandyari-Kalejahi, A.; Afsari-Ghazi, M.; Noori, K.; Irani, S. [Department of Physics, Faculty of Science, Azarbaijan University of Shahid Madani, 51745-406, Tabriz (Iran, Islamic Republic of)

    2012-08-15T23:59:59.000Z

    Propagation of large amplitude dust-acoustic (DA) solitary waves is investigated in electron-positron-ion plasmas in the presence of dust grains using Sagdeev potential method. It is shown that acceptable values of Mach number for propagation of the large amplitude DA solitary waves depend strongly on plasma parameters. It is also observed that the amplitude of DA solitary waves increases as both the Mach number M and dust charge Z{sub d} are increased. Furthermore, it is found that a dusty plasma with inertial dust fluid and Boltzmann distributed electrons, positrons, and ions admits only negative solitary potentials associated with nonlinear dust-acoustic waves. In addition, it is remarked that the formation of double layers is not possible in this plasma system.

  13. Microgrids: distributed on-site generation

    E-Print Network [OSTI]

    Watson, Andrew

    : · Diversity of the load profile as a function of microgrid size; · Feasibility of accurate control of bothMicrogrids: distributed on-site generation Suleiman Abu-Sharkh, Rachel Li, Tom Markvart, Neil Ross for Climate Change Research Technical Report 22 #12;1 Microgrids: distributed on-site generation Tyndall

  14. Sequence stratigraphy, facies architecture and reservoir distribution, Cretaceous lowstand fan reservoirs, Southern Basin, onshore Trinidad

    SciTech Connect (OSTI)

    Sprague, A.R.; Larue, D.K.; Faulkner, B.L. [Exxon Production Research Company, Houston, TX (United States)] [and others

    1996-08-01T23:59:59.000Z

    Thick Albian-Campanian mass-flow sandstones in the Southern Basin Trinidad were deposited within submarine canyons incised into the northern continental slope of South America and as associated down-dip basin-floor lowstand fans. The contemporaneous slope to basin-floor break lay across the Southern Basin area with turbidity current paleoflow being to the northwest. North of this paleo-slope break graded to massive, channelized, high-density turbidite sandstones occur interstratified with shaly overbank and channel abandonment deposits. A progression of depositional sub-environments from proximal through distal lowstand fan can be recognized. All fine and thin upward but can be discriminated by the occurrence of slumps, debris flows and conglomerates, the grain-size and bedding scale of sandstones and the characteristics of low-density turbidites and mudrocks. South of the paleo-slope break mass-flow deposits comprise muddy slumps and debris flows rich in granules and pebbles deposited in slope canyons. During periods of turbidity current by-pass or fan abandonment hemipelagic settling processes predominated. Reservoir distribution maps of these lowstand fans have been constructed utilizing geometric constraints, analogs and paleoslope determinations from oriented core. The interpreted canyon locations and orientations are key to the understanding of reservoir distribution on the basin-floor tract to the north: a vital component in the exploration of the basin.

  15. Strain modification in thin Si1 x yGexCy alloys on ,,100... Si for formation of high density and uniformly sized quantum dots

    E-Print Network [OSTI]

    size, increase the density of islands, and significantly narrow the distribution of island sizes for dislocation generation within the three-dimensional islands, which then limits the maximum height which and the island size distribution becomes broader with the increase of misfit and strain. The optimal growth

  16. Low-Cycle Fatigue of Ultra-Fine-Grained Cryomilled 5083 Aluminum Alloy

    E-Print Network [OSTI]

    Walley, J. L.; Lavernia, E. J.; Gibeling, J. C.

    2009-01-01T23:59:59.000Z

    an Ultra-Fine Grained Aluminum Alloy, Poster Session, TMS,with other MA aluminum alloys and is attributed to theGrained Cryomilled 5083 Aluminum Alloy J.L. WALLEY, E.J.

  17. An evaluation of grain boundary engineering technology and processing scale-up

    E-Print Network [OSTI]

    Zelinski, Jeffrey A

    2005-01-01T23:59:59.000Z

    Grain boundary engineering is the manipulation of low stacking-fault energy, face- centered cubic material microstructures to break the connectivity of the general grain boundary network through the addition of special ...

  18. Grain-boundary engineering markedly reduces susceptibility to intergranular hydrogen embrittlement in metallic materials

    E-Print Network [OSTI]

    Ritchie, Robert

    Grain-boundary engineering markedly reduces susceptibility to intergranular hydrogen embrittlement. Keywords: Hydrogen embrittlement; Intergranular cracking; Grain-boundary engineering; Special boundaries,e,* a Department of Materials Science and Engineering, University of California, Berkeley, CA 94720, USA b

  19. Modeling Elasto-Plastic Behavior of Polycrystalline Grain Structure of Steels at Mesoscopic Level

    E-Print Network [OSTI]

    Cizelj, Leon

    Modeling Elasto-Plastic Behavior of Polycrystalline Grain Structure of Steels at Mesoscopic Level. The constitutive model of crystal grains utilizes anisotropic elasticity and crystal plasticity. Commercially be considered macroscopically homogeneous. Elastic and rate independent plastic deformation modes are considered

  20. Influence of grain boundary energy on the nucleation of complexion transitions

    E-Print Network [OSTI]

    Rohrer, Gregory S.

    Influence of grain boundary energy on the nucleation of complexion transitions Stephanie A different transition tem- peratures. It has been hypothesized that higher energy grain boundaries have relative energies preferentially undergo complexion transitions. Our experiment uses a unique sandwich

  1. Mechanical Properties and Radiation Tolerance of Ultrafine Grained and Nanocrystalline Metals

    E-Print Network [OSTI]

    Sun, Cheng

    2013-04-26T23:59:59.000Z

    loops. Here we provide experimental evidence that high angle grain boundaries can effectively remove radiation-induced defects. The equal channel angular pressing (ECAP) technique was used to produce ultrafine grained Fe-Cr-Ni alloy. Mechanical...

  2. Low-Cycle Fatigue of Ultra-Fine-Grained Cryomilled 5083 Aluminum Alloy

    E-Print Network [OSTI]

    Walley, J. L.; Lavernia, E. J.; Gibeling, J. C.

    2009-01-01T23:59:59.000Z

    of an Ultra-Fine Grained Aluminum Alloy, Poster Session,Grained Cryomilled 5083 Aluminum Alloy J.L. WALLEY, E.J.consistent with other MA aluminum alloys and is attributed

  3. Emergence of skew distributions in controlled growth processes

    E-Print Network [OSTI]

    Segun Goh; H. W. Kwon; M. Y. Choi; Jean-Yves Fortin

    2011-04-03T23:59:59.000Z

    Starting from a master equation, we derive the evolution equation for the size distribution of elements in an evolving system, where each element can grow, divide into two, and produce new elements. We then probe general solutions of the evolution quation, to obtain such skew distributions as power-law, log-normal, and Weibull distributions, depending on the growth or division and production. Specifically, repeated production of elements of uniform size leads to power-law distributions, whereas production of elements with the size distributed according to the current distribution as well as no production of new elements results in log-normal distributions. Finally, division into two, or binary fission, bears Weibull distributions. Numerical simulations are also carried out, confirming the validity of the obtained solutions.

  4. JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 103,NO. D3, PAGES 3419-3435,FEBRUARY 20, 1998 Size-resolvedand chemicallyresolvedmodel

    E-Print Network [OSTI]

    Dabdub, Donald

    . An atmospheric aerosol is characterized by both its size and composition distribution.The mostgeneralformParticulateMatter model[Binkowski and Shankar, 1995] assumesthat the aerosol size distribution adheresto a bimodal,includingnucleation,condensation, coagulation,chemicaltransformationin the gas,aerosol,and aqueous(cloud and fog) phases

  5. DISTRIBUTED DATABASES INTRODUCTION

    E-Print Network [OSTI]

    Liu, Chengfei

    D DISTRIBUTED DATABASES INTRODUCTION The development of network and data communication tech- nology distributed database management. Naturally, the decen- tralized approach reflects the distributed aspects in the definition of a distributed database exist. First, a distributed database is distributed

  6. Evaluating chemical and physical properties of grain dust for use in an explosion hazard indicator

    E-Print Network [OSTI]

    Plemons, Dorothy Sue

    1981-01-01T23:59:59.000Z

    . 06 iIm 15. 0 0 ) 15. 6 10. 0 5. 0 3 4 7. 2 8. 5 5 6 4 0 . . . 3. 3 1. 7 1. 7 14 1 ~ 5 12 3. 0 0. 0 O CV O Yl CO O CO O N I I I O O ICI I CI O CC I CI cn 4 0 CV ch I CO I O O CO I O I O C: CI I Particle Size Ranges... 3 Q 2. 1 0. 6 0. 6 I CI CI 6 IO Yl CD 0 CI P4 I I I I I I CI N N 0 Yl (O I CI C) I U3 CI co I I CI CI CI I m Particle Size Ranges, um FIG. 14 Coulter Counter particle size distribution of rice dust, 30. 0 25. 0 20. 0 Mean...

  7. POPe689. (Submitted to Ap. J.) Radiative Torques on Interstellar Grains

    E-Print Network [OSTI]

    Draine, Bruce T.

    @phoenix.princeton.edu ABSTRACT Radiative torques on irregular dust grains, in addition to producing superthermal rotation, play

  8. Effect of grain orientation on ductility in a nanocrystalline Ni-Fe alloy

    SciTech Connect (OSTI)

    Li, Hongqi [Los Alamos National Laboratory; Misra, Amit [Los Alamos National Laboratory; Liaw, Peter K [UNIV OF TENN; Choo, Hahn [UNIV OF TENN

    2008-01-01T23:59:59.000Z

    The influence of columnar grain geometry on mechanical property was studied in an electrodeposited nanocrystalline Ni-Fe alloy. The compressive results show that the strength is independent of grain orientation. However, the plastic strain increased remarkably when the loading axis is parallel to the direction of grain columns, which is due to the enhanced grain boundary and dislocation activities. The significance of the current study is that a new strategy was developed to improve the ductility of nanocrystalline materials.

  9. South Carolina Pest Management Handbook for Field Crops 2014 FARM-STORED GRAIN INSECT MANAGEMENT

    E-Print Network [OSTI]

    Duchowski, Andrew T.

    are loaded, clean up all spilled grain. Keep ground around bins clear of weeds and debris. Proper storage the grain is loaded into the bin for storage. After loading the best you can do is to try to maintain this level of quality. Thus, it is important to maximize the quality of your grain prior to storage

  10. South Carolina Pest Management Handbook for Field Crops 2013 FARM-STORED GRAIN INSECT MANAGEMENT

    E-Print Network [OSTI]

    Stuart, Steven J.

    , clean up all spilled grain. Keep ground around bins clear of weeds and debris. Proper storage management the grain is loaded into the bin for storage. After loading the best you can do is to try to maintain this level of quality. Thus, it is important to maximize the quality of your grain prior to storage

  11. A Study of the Grain Boundaries and Hydrogen in HF-CVD Diamond Films

    E-Print Network [OSTI]

    Adler, Joan

    composition of grain boundaries in polycrystalline diamond lms by transmission electron microscopy and highA Study of the Grain Boundaries and Hydrogen in HF-CVD Diamond Films Israel Yoel Koenka #12;A Study of the Grain Boundaries and Hydrogen in HF-CVD Diamond Films Research Thesis In partial fulllment

  12. Pressure Solution: Possible Mechanism for Silicate Grain Dissolution in a Petrocalcic Horizon

    E-Print Network [OSTI]

    Ahmad, Sajjad

    Pressure Solution: Possible Mechanism for Silicate Grain Dissolution in a Petrocalcic Horizon H in southern New Mexico, up to 58% of the silicate grains have dissolution fea- tures, such as embayed-solution mechanism in the petrocaIcic horizon: (i) silicate grains are smooth where they contact pores, but serrated

  13. CONTINUED INVESTIGATION OF PRESOLAR SILICATE GRAINS IN THE CARBONACEOUS CHONDRITE NINGQIANG. X. Zhao1,2

    E-Print Network [OSTI]

    CONTINUED INVESTIGATION OF PRESOLAR SILICATE GRAINS IN THE CARBONACEOUS CHONDRITE NINGQIANG. X in extraterrestrial materials, silicate grains can help us investigate the nucleosynthetic processes and evolution of their parent stellar sources. Numerous studies have been carried out to search for presolar silicate grains

  14. Mesoscale Simulation of Grain David Kinderlehrer, Jeehyun Lee, Irene Livshits and Shlomo Ta'asan

    E-Print Network [OSTI]

    Mesoscale Simulation of Grain Growth David Kinderlehrer, Jeehyun Lee, Irene Livshits and Shlomo Ta'asan WILEY-VCH Verlag Berlin GmbH September 4, 2003 #12;2 0.1 Introduction The mesoscale simulation of grain of the statistics it provides, we are led to the companion issue of coarse graining in mesoscale simulations. We

  15. On the relation between the Luders deformation and grain boundary structure in aluminium alloy

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1001 On the relation between the Luders deformation and grain boundary structure in aluminium alloy of grain bound- ary structure and its effect on the aluminium alloy strain hardening. 2. Expérimental. Abstract. - Strain hardening of the fine grained AlMg6 alloy at room temperature was studied after

  16. Port of Houston Intermodal Grain Transfer System and Market Area, 1976 - 1977. 

    E-Print Network [OSTI]

    Fuller, Stephen W.; Paggi, Mechel S.

    1978-01-01T23:59:59.000Z

    Railroads ................................................. 4 Trucks .................................................. 7 Ships ................................................... 7 Grain Elevators ........................................... 10 Port... of the receipts were from Oklahoma. lowa, raska, and Kansas shipped 15, 1 1, and 10 percent of e Port's respective grain and soybean inflow. Texas ranked first as an originator of grain sorghum (59%) and second as a source of wheat (3 1%) and soybeans (35...

  17. Control of Transcription by Cell Size

    E-Print Network [OSTI]

    Wu, Chia-Yung

    Cell size increases significantly with increasing ploidy. Differences in cell size and ploidy are associated with alterations in gene expression, although no direct connection has been made between cell size and transcription. ...

  18. 5, 52235252, 2005 Size-resolved source

    E-Print Network [OSTI]

    Boyer, Edmond

    , gasoline vehicle, diesel vehicle, copper smelter, and volcano emission. PMF analysis of size% in the fine size range (0.56­2.5 µm). The diesel vehicle source contributed the most in the ultra-fine size

  19. Comment on "The shape and composition of interstellar silicate grains"

    E-Print Network [OSTI]

    J. P. Bradley; H. A. Ishii

    2008-04-17T23:59:59.000Z

    This Comment is in response to an Erratum to the paper entitled "The shape and composition of interstellar silicate grains" (Min et al., A&A, 462, 667-676 (2007). The Erratum corrects erroneously cited data but upholds the paper's original conclusions that GEMS are not remnant interstellar grains and that most GEMS formed in the early solar system. In our Comment, we show that the correct data in fact strengthen the relationship between GEMS and interstellar silicates, contrary to the conclusions of Min et al. in their Erratum. We also explore the validity of the isotopic and bulk chemical bases for comparison and present additional indicators of past ISM radiation processing of silicates.

  20. Magnetorotational instability in plasmas with mobile dust grains

    SciTech Connect (OSTI)

    Ren Haijun [CAS Key Laboratory of Basic Plasma Physics, Department of Modern Physics, University of Science and Technology of China, Hefei 230026 (China); Cao Jintao [Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Li Ding [CAS Key Laboratory of Basic Plasma Physics, Department of Modern Physics, University of Science and Technology of China, Hefei 230026 (China); Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Chu, Paul K. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong)

    2013-03-15T23:59:59.000Z

    The magnetorotational instability of dusty plasmas is investigated using the multi-fluid model and the general dispersion relation is derived based on local approximation. The dust grains are found to play an important role in the dispersion relation in the low-frequency mode and exhibit destabilizing effects on the plasma. Both the instability criterion and growth rate are affected significantly by the dust and when the dust is heavy enough to be unperturbed, the reduced dispersion relations are obtained. The instability criteria show that the dust grains have stabilizing effects on the instability when the rotation frequency decreases outwards and conversely lead to destabilizing effects when the rotation frequency increases outwards. The results are relevant to accession and protoplanetary disks.