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Note: This page contains sample records for the topic "grain size distribution" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

Obtaining a bimodal grain size distribution via thermal means  

Science Conference Proceedings (OSTI)

Presentation Title, Obtaining a bimodal grain size distribution via thermal means ... manipulating thermal history, a family of bimodal grain size distributions may be formed. ... Mild Carbon Steel Quenche in Coconut Water, Fresh urine, Nigerian unadultrated up-wine, ... Multi-scale modeling of phase transformations in steels.

2

EVOLUTION OF SIZE DISTRIBUTION OF ICY GRAINS BY SUBLIMATION AND CONDENSATION  

SciTech Connect

In the outer part of a protoplanetary disk, dust grains consist of silicate core covered by an ice mantle. A temporal heating event in the disk results in sublimation of the ice mantle. After the end of the heating event, as the temperature decreases, H{sub 2}O molecules recondense on the surface of the dust grain. Ultimately, the dust grain is covered by an ice mantle. Because the equilibrium vapor pressure on the grain surface decreases with the grain size, a large grain grows faster than a small grain. As a result, the size of an icy dust grain changes as a result of the heating event. The change in size also affects the mechanical properties of the dust aggregates formed by the icy grains. In this paper, we investigated the evolution of the size distribution of icy dust grains during sublimation and condensation. We found that the size evolution of icy grains can be divided into two stages. In the first stage, the icy grains grow through condensation of H{sub 2}O molecules. In the second stage, the size of grains changes further as H{sub 2}O molecules are transferred between icy grains while the surrounding gas condenses. The size distribution of the icy dust grains becomes bimodal, with a small number of relatively large grains and many small grains without an icy mantle. Possible effects of the size change on the evolution of icy dust aggregates are discussed.

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

2011-09-20T23:59:59.000Z

3

The grain size distribution and the detection of abnormal grain growth of austenite in an eutectoid steel containing niobium  

SciTech Connect

The abnormal grain growth of austenite was studied in a commercial steel of composition (wt%): 0.70 C, 1.36 Mn, 0.72 Si, 0.015 P, 0.027 S and 0.03 Nb. Specimens were thermocycled at various conditions and then grain size distribution determined. The grain size distribution shape did not change during normal grain growth but this distribution widened and flattened during the abnormal grain growth. The initial smaller mean size of carbonitrides and/or the highest homogeneity of niobium carbonitride size distribution of the samples submitted to thermal cycles, in comparison with the normalized samples, increased the abnormal grain growth temperature from 1,373 K to 1,473 K.

Bruno, J.C. (Instituto Militar de Engenharia, Rio de Janeiro (Brazil). Dept. de Engenharia Mecanica e de Materiais); Rios, P.R. (Pontificia Univ. Catolica do Rio de Janeiro (Brazil). Dept. de Ciencia dos Materiais e Metalurgia)

1995-02-15T23:59:59.000Z

4

Dust Grain-Size Distributions From MRN to MEM  

E-Print Network (OSTI)

Employing the Maximum Entropy Method algorithm, we fit interstellar extinction measurements which span the wavelength range 0.125-3 micron. We present a uniform set of MEM model fits, all using the same grain materials, optical constants and abundance constraints. In addition, we are taking advantage of improved UV and IR data and better estimates of the gas-to-dust ratio. The model fits cover the entire range of extinction properties that have been seen in the Galaxy and the Magellanic Clouds. The grain models employed for this presentation are the simplistic homogeneous spheres models (i.e., Mathis, Rumpl, & Nordsieck 1977) with two (graphite, silicate) or three (graphite, silicate, amorphous carbon) components. Though such usage is only a first step, the results do provide interesting insight into the use of grain size as a diagnostic of dust environment. We find that the SMC Bar extinction curve cannot be fit using carbon grains alone. This is a challenge to the recent observational result indicating little silicon depletion in the SMC.

Geoffrey C. Clayton; Michael J. Wolff; Ulysses J. Sofia; K. D. Gordon; K. A. Misselt

2003-01-24T23:59:59.000Z

5

Grain size distributions and photo-electric heating in ionized media  

E-Print Network (OSTI)

Ever since the pioneering study of Spitzer, it has been widely recognized that grains play an important role in the heating and cooling of photo-ionized environments. A detailed code is necessary to model grains in a photo-ionized medium. In this paper we will use the spectral synthesis code Cloudy for this purpose. The grain model of this code has recently undergone a comprehensive upgrade. Part of this is the newly developed hybrid grain charge model, which will be described in detail. This model allows discrete charge states of very small grains to be modelled accurately while simultaneously avoiding the overhead of fully resolving the charge distribution of large grains, thus making the model both accurate and computationally efficient. A comprehensive comparison with the fully resolved charge state models of Weingartner & Draine (2001) shows that the agreement is very satisfactory for realistic size distributions. The effect of the grain size distribution on the line emission from photo-ionized regions is studied by taking standard models for an H II region and a planetary nebula and adding a dust component to the models with varying grain size distributions. A comparison of the models shows that varying the size distribution has a dramatic effect on the emitted spectrum, and affects the ionization balance as well. These results clearly demonstrate that the grain size distribution is an important parameter in photo-ionization models.

P. A. M. van Hoof; J. C. Weingartner; P. G. Martin; K. Volk; G. J. Ferland

2004-02-16T23:59:59.000Z

6

Grain size distributions and photo-electric heating in ionised media  

E-Print Network (OSTI)

Ever since the pioneering study of Spitzer, it has been widely recognised that grains play an important role in the heating and cooling of photo-ionised environments. A detailed code is necessary to model grains in a photo-ionised medium. In this paper we will use the spectral synthesis code Cloudy for this purpose. The grain model of this code has recently undergone a comprehensive upgrade. Part of this is the newly developed hybrid grain charge model, which will be described in detail. This model allows discrete charge states of very small grains to be modelled accurately while simultaneously avoiding the overhead of fully resolving the charge distribution of large grains, thus making the model both accurate and computationally efficient. A comprehensive comparison with the fully resolved charge state models of Weingartner & Draine (2001) shows that the agreement is very satisfactory for realistic size distributions. The effect of the grain size distribution on the line emission from photo-ionised regio...

Van Hoof, P A M; Martin, P G; Volk, K; Ferland, G J

2004-01-01T23:59:59.000Z

7

Influence of charging process and size distribution of dust grain on the electric conductivity of dusty plasma  

Science Conference Proceedings (OSTI)

The effects of dust size distribution and charging process of dust grains on the complex electric conductivity of dusty plasmas have been investigated in the present paper. Comparisons are made between real dusty plasma in which there are many different dust grain species and the mono-sized dusty plasma (MDP) in which there is only one kind of dust grain whose size is the average dust size. In some cases the complex electric conductivity of real dusty plasma is larger than that of MDP, while in other cases it is smaller than that of MDP, it depends on the dust size distribution function.

Duan Jizheng; Wang Canglong; Zhang Jianrong; Ma Shengqian; Hong Xueren; Sun Jianan [College of Physics and Electronic Engineering and Joint Laboratory of Atomic and Molecular Physics of NWNU and IMP CAS, Northwest Normal University, Lanzhou 730070 (China) and Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Duan Wenshan [College of Physics and Electronic Engineering and Joint Laboratory of Atomic and Molecular Physics of NWNU and IMP CAS, Northwest Normal University, Lanzhou 730070 (China) and Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Atomic and Molecular Physics and Functional Materials of Gansu Province, College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070 (China); Yang Lei [College of Physics and Electronic Engineering and Joint Laboratory of Atomic and Molecular Physics of NWNU and IMP CAS, Northwest Normal University, Lanzhou 730070 (China) and Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Department of Physics, Lanzhou University, Lanzhou 730000 (China)

2012-08-15T23:59:59.000Z

8

Characterization of Grain Size, Morphology, Transmittance, and ...  

Science Conference Proceedings (OSTI)

Feb 16, 2010 ... Characterization of Minerals, Metals and Materials: Characterization of Grain Size, Morphology, Transmittance, and Tomography Sponsored ...

9

Raindrop Size Distribution  

Science Conference Proceedings (OSTI)

This paper reviews some of the published results relating to raindrop-size distributions and couples this with some of the authors' results in order to show that the mathematical description of the distribution can be divided into three ...

M. C. Hodson

1986-07-01T23:59:59.000Z

10

Multimodal Raindrop Size Distributions  

Science Conference Proceedings (OSTI)

The raindrop size distributions (DSDs) observed over a short span usually have an erratic shape, with several relative maxima. This multimodal structure is studied from disdrometer data acquired in tropical and midlatitude areas. It is shown that ...

Henri Sauvageot; Manlandon Koffi

2000-08-01T23:59:59.000Z

11

Grain size effects on the fatigue response of nanocrystalline materials  

E-Print Network (OSTI)

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 ...

Hanlon, Timothy, 1977-

2004-01-01T23:59:59.000Z

12

Size-dependent same-material tribocharging in insulating grains  

E-Print Network (OSTI)

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.

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

2013-09-10T23:59:59.000Z

13

ARM - Measurement - Hydrometeor Size Distribution  

NLE Websites -- All DOE Office Websites (Extended Search)

Size Distribution Size Distribution ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Hydrometeor Size Distribution The number of hydrometeors observed in a given size range. Categories Cloud Properties, Atmospheric State Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments LDIS : Laser Disdrometer Datastreams LDIS : Laser Disdrometer Datastreams PARS2 : OTT Parsivel2 Laser Disdrometer VDIS : Video Disdrometer Datastreams VDIS : Video Disdrometer Drop Size Distribution

14

New Method for Rapid Measurement of Orientations and Sizes of Grains in Multicrystalline Silicon Wafers  

SciTech Connect

We describe a new technique for rapid measurement of orientations and sizes of various grains in a multicrystalline silicon (mc-Si) wafer. The wafer is texture etched to expose (111) faces nearest to each surface. Because grains of different orientations result in uniquely different texture shapes, they also have well-defined reflectance values. Hence, the process of determining the grain orientations is brought down to making reflectance maps. Reflectance maps are produced by PVSCAN or reflectometer (GT FabScan), and then transformed into orientation maps. Because the grain boundaries are very well delineated in the reflectance maps, they are also excellent for making measurements of size and distribution of grains. We will compare the results of this technique with other standard techniques.

Sopori, B.; Guhabiswas, D.; Rupnowski, P.; Shet, S.; Devayajanam, S.; Moutinho, H.

2011-01-01T23:59:59.000Z

15

Exponential Size Distributions for Snow  

Science Conference Proceedings (OSTI)

Using airborne data from several recent field projects, the authors have taken another look at the properties of exponential ice particle size distributions (PSDs) when the PSDs are broad. Two primary questions are addressed: for what ranges of ...

Andrew J. Heymsfield; Paul Field; Aaron Bansemer

2008-12-01T23:59:59.000Z

16

Parameterizing the Raindrop Size Distribution  

Science Conference Proceedings (OSTI)

This paper addresses the problem of finding a parametric form for the raindrop size distribution (DSD) that 1) is an appropriate model for tropical rainfall, and 2) involves statistically independent parameters. Such a parameterization is derived ...

Ziad S. Haddad; Stephen L. Durden; Eastwood Im

1996-01-01T23:59:59.000Z

17

ARM - Measurement - Particle size distribution  

NLE Websites -- All DOE Office Websites (Extended Search)

size distribution size distribution ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Particle size distribution The number of particles present in any given volume of air within a specified size range. Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments AOS : Aerosol Observing System CSPHOT : Cimel Sunphotometer TDMA : Tandem Differential Mobility Analyzer UHSAS : Ultra-High Sensitivity Aerosol Spectrometer Field Campaign Instruments

18

The double effect of grain size on the work hardening behavior of polycrystalline copper  

Science Conference Proceedings (OSTI)

Following the approach by Ashby, one can consider that strain compatibility between adjacent grains of a polycrystal generates geometrical dislocations. These dislocations participated in the strengthening mechanism in conjunction with statistically stored dislocations which are related to the single-crystal behavior. The dislocations of either species are indistinguishable and, as a whole, they may contribute to cell formation. The dislocation structure formed in a polycrystal is then a function of the major or minor intergranular accommodation complexity. At intermediate strain values the accommodation is distributed over the cells leading to a linear relationship between the tensile stress and the inverse of the cell size, whatever the grain size of the tested samples. The aim of the present work is to check that the presence of statistical and geometrical dislocations in the grains, as well as the fact that at the very early stage of plastic deformation the mean free path of dislocations is of the order of the grain size, leads to a double effect of the grain size on the work hardening behavior of polycrystalline copper. Moreover, careful analysis of the mechanical behavior of polycrystalline copper, including the microstructural aspects of plastic deformation, is performed, allowing the understanding of the relationship between the work hardening ratio and the grain size.

Gracio, J.J. (Univ. de Aveiro (Portugal). Dept. de Engenharia Mecanica)

1994-08-15T23:59:59.000Z

19

Peaks in Raindrop Size Distributions  

Science Conference Proceedings (OSTI)

The multipeak behavior of raindrop size distributions has been studied. Peaks have been found for distinct drop diameters: 0.7, 1.0, 1.9, and possibly 3.2 mm. The probability is about 65% that at least one of these peaks exists in an observed ...

M. Steiner; A. Waldvogel

1987-10-01T23:59:59.000Z

20

The Spectral Energy Distribution of HH30 IRS: Constraining The Circumstellar Dust Size Distribution  

E-Print Network (OSTI)

We present spectral energy distribution (SED) models for the edge-on classical T Tauri star HH30 IRS that indicate dust grains have grown to larger than 50 microns within its circumstellar disk. The disk geometry and inclination are known from previous modeling of multiwavelength Hubble Space Telescope images and we use the SED to constrain the dust size distribution. Model spectra are shown for different circumstellar dust models: a standard ISM mixture and larger grain models. As compared to ISM grains, the larger dust grain models have a shallower wavelength dependent opacity. Models with the larger dust grains provide a good match to the currently available data, but mid and far-IR observations are required to more tightly constrain the dust size distribution. The accretion luminosity in our models is L_accdistributions that are simple power-law extensions (i.e., no exponential cutoff) yield acceptable fits to the optical/near-IR but too much emission at mm wavelengths and require larger disk masses. Such a simple size distribution would not be expected in an environment such as the disk of HH30 IRS, particularly over such a large range in grain sizes. However, its ability to adequately characterize the grain populations may be determined from more complete observational sampling of the SED in the mid to far-IR.

Kenneth Wood; Michael J. Wolff; J. E. Bjorkman; Barbara Whitney

2001-09-04T23:59:59.000Z

Note: This page contains sample records for the topic "grain size distribution" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Unconsolidated sand grain shape, size impact frac-pack design  

SciTech Connect

The shape and size of sand grains, as well as the saturating fluid, influence the mechanical properties of unconsolidated sands and need to be considered in frac-pack design. These mechanical properties of unconsolidated properties of unconsolidated sands play an important role in determining the geometry of frac-pack treatments. Stress-strain curves obtained for unconsolidated sands at elevated stresses show highly nonlinear hysteretic behavior. The impact of these findings on frac-pack design can be significant. The nonlinear elastic properties of unconsolidated sand can give rise to some unique features in the pressure response and in the fracture geometry that may not be observed in hard rocks. This article focuses on the impact of mechanical properties of poorly consolidated and unconsolidated sands on the geometry of frac packs. The paper discusses frac packs, mechanical properties (Young`s modulus, shear failure) and effective treatments.

Wang, E.; Sharma, M.M. [Univ. of Texas, Austin, TX (United States)

1997-05-19T23:59:59.000Z

22

Grain Size Effects on the Mechanical Properties of Bulk Structural ...  

Science Conference Proceedings (OSTI)

Unconventional Short-Term Glow Discharge Nitriding of 316l Austenitic Steel · Using Accumulative Roll Bonding to Process Ultrafine Grained ...

23

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

DOE Green Energy (OSTI)

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

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

2008-08-01T23:59:59.000Z

24

Production mechanisms, number concentration, size distribution...  

NLE Websites -- All DOE Office Websites (Extended Search)

Wiley Online Library (wileyonlinelibrary.com) DOI: 10.1002asl2.441 Meeting Report Production mechanisms, number concentration, size distribution, chemical composition, and...

25

Gamma Size Distribution and Stochastic Sampling Errors  

Science Conference Proceedings (OSTI)

A maximum likelihood approach to the application of the gamma size distribution is described and compared with the method of moments approach suggested by Ulbrich. Estimation of distribution parameters based on the maximum likelihood principle ...

Raymond K. W. Wong; Norman Chidambaram

1985-06-01T23:59:59.000Z

26

The Shape of Averaged Drop Size Distributions  

Science Conference Proceedings (OSTI)

The shape of averaged drop size distributions (DSD) is studied from a large sample of data (892 h) collected at several sites of various latitudes. The results show that neither the hypothesis of an exponential distribution to represent rainfall ...

Henri Sauvageot; Jean-Pierre Lacaux

1995-04-01T23:59:59.000Z

27

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

SciTech Connect

Laboratory experiments were performed to investigate the contribution of variable grain sizes to uranium adsorption/desorption in a sediment collected from the US DOE Hanford site. The sediment was wet-sieved into four size fractions: coarse sand (1-2 mm), medium sand (0.2-1 mm), fine sand (0.05-0.2 mm), and clay/silt fraction (< 0.05mm). For each size fraction and their composite (sediment), batch experiments were performed to determine uranium adsorption isotherms, and stirred flow-cell experiments were conducted to derive kinetic data of uranium adsorption and subsequent desorption. The results showed that uranium adsorption isotherms and adsorption/desorption kinetics were size-specific, reflecting the effects of size-specific adsorption site concentration and kinetic rate constants. The larger-size fraction had a larger mass percentage in the sediment, but with a smaller adsorption site concentration and generally a slower uranium adsorption/desorption rate. The same equilibrium surface complexation reaction and reaction constant could describe uranium adsorption isotherms for all size fractions and the composite after accounting for the effect of adsorption site concentration. Mass-weighted, linear additivity was observed for both uranium adsorption isotherms and adsorption/desorption kinetics in the composite. Our analysis also showed that uranium adsorption site concentration estimated from the adsorption isotherms was 3 orders of magnitude less than a site concentration estimated from sediment surface area and generic site density. One important implication of this study is that grain size distribution may be used to estimate uranium adsorption site, and adsorption/desorption kinetic rates in heterogeneous sediments from a common location.

Shang, Jianying; Liu, Chongxuan; Wang, Zheming; Zachara, John M.

2011-07-27T23:59:59.000Z

28

Mechanical Properties of Materials with Emphasis on Grain-Size ...  

Science Conference Proceedings (OSTI)

July 29, 2010 ... In this contribution an overview of the fracture behaviour of various metals ranging from one phase ultrafine grained bcc and fcc ... and Materials Science, Russian Academy of Sciences; 2Ufa State Aviation Technical University

29

Underwater microscope for measuring spatial and temporal changes in bed-sediment grain size  

E-Print Network (OSTI)

Underwater microscope for measuring spatial and temporal changes in bed-sediment grain size David M by Elsevier B.V. Keywords: Underwater microscope; Bed sediment; Grain size; In situ measurement; Colorado counts on a small subset of processed images. 2.3. Underwater microscope hardware Digital images of bed

30

Gradually Truncated Log-normal distribution- Size distribution of firms  

E-Print Network (OSTI)

Many natural and economical phenomena are described through power law or log-normal distributions. In these cases, probability decreases very slowly with step size compared to normal distribution. Thus it is essential to cut-off these distributions for larger step size. Recently we introduce the gradually truncated power law distribution to successfully describe variation of financial, educational, physical and citation index. In the present work, we introduce gradually truncated log-normal distribution in which we gradually cut-off larger steps due to physical limitation of the system. We applied this distribution successfully to size distribution of USAŽs manufactoring firms which is measured through their annual sell. The physical limitation are due to limited market size or shortage of highly competent executives. I.

Hari M. Gupta; José R. Campanha

2008-01-01T23:59:59.000Z

31

Particle size distribution instrument. Topical report 13  

DOE Green Energy (OSTI)

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

Okhuysen, W.; Gassaway, J.D.

1995-04-01T23:59:59.000Z

32

Raindrop Size Distribution Measurements in Tropical Cyclones  

Science Conference Proceedings (OSTI)

Characteristics of the raindrop size distribution in seven tropical cyclones have been studied through impact-type disdrometer measurements at three different sites during the 2004–06 Atlantic hurricane seasons. One of the cyclones has been ...

Ali Tokay; Paul G. Bashor; Emad Habib; Takis Kasparis

2008-05-01T23:59:59.000Z

33

Acoustic Sounding of Raindrop Size Distribution  

Science Conference Proceedings (OSTI)

Radars have been successfully used for remote measurements of raindrop size distribution and rain intensity for many years. Over the last two decades, sodars have been increasingly applied to measure the parameters of precipitation. In the ...

Sergei V. Shamanaev

2003-01-01T23:59:59.000Z

34

A General Formulation for Raindrop Size Distribution  

Science Conference Proceedings (OSTI)

A general phenomenological formulation for drop size distribution (DSD), written down as a scaling law, is proposed. It accounts for all previous fitted DSDs. As a main implication of the expression proposed, the integral rainfall variables are ...

Daniel Sempere Torres; Josep M. Porrà; Jean-Dominique Creutin

1994-12-01T23:59:59.000Z

35

What is a Raindrop Size Distribution?  

Science Conference Proceedings (OSTI)

It is commonly understood that the number of drops that one happens to measure as a function of diameter in some sample represents the drop size distribution. However, recent observations show that rain is "patchy" suggesting that such a ...

A. R. Jameson; A. B. Kostinski

2001-06-01T23:59:59.000Z

36

Crushed Coal Particle Size Distribution Monitoring  

Science Conference Proceedings (OSTI)

This report summarizes an evaluation of different commercially available technologies for on-line monitoring of crushed coal size distribution with a subsequent laboratory test of the most promising system. The technology evaluation focused on image-based approaches for evaluating crushed coal size distribution that would address previous challenges encountered, including depth of field, image scale dependency upon the distance of the sample from the lens, image shadows caused by perimeter lighting, ...

2013-09-11T23:59:59.000Z

37

ARM - Measurement - Cloud particle size distribution  

NLE Websites -- All DOE Office Websites (Extended Search)

size distribution size distribution ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud particle size distribution The number of cloud particles present in any given volume of air within a specified size range, including liquid and ice. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments WSACR : Scanning ARM Cloud Radar, tuned to W-Band (95GHz) Field Campaign Instruments CPI : Cloud Particle Imager CLDAEROSMICRO : Cloud and Aerosol Microphysical Properties

38

ARM - Measurement - Aerosol particle size distribution  

NLE Websites -- All DOE Office Websites (Extended Search)

particle size distribution particle size distribution ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Aerosol particle size distribution The number of aerosol particles present in any given volume of air within a specificied size range Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments SMPS : Scanning mobility particle sizer TDMA : Tandem Differential Mobility Analyzer UHSAS : Ultra-High Sensitivity Aerosol Spectrometer Field Campaign Instruments

39

Influence of grain size, morphology and aggregation on galena dissolution.  

E-Print Network (OSTI)

??The acidic, non-oxidative dissolution of galena nanocrystals has been studied using both microscopic and wet-chemical methods. The effects of particle size, shape, aggregation state, and… (more)

Liu, Juan

2009-01-01T23:59:59.000Z

40

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

DOE Patents (OSTI)

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.

Maris, Humphrey J (Barrington, RI)

2000-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "grain size distribution" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

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

DOE Patents (OSTI)

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.

Maris, Humphrey J (Barrington, RI)

2001-01-01T23:59:59.000Z

42

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

E-Print Network (OSTI)

Relative grain boundary area and energy distributions in nickel Jia Li, Shen J. Dillon 1 , Gregory crystallographic parameters, a quantity that will be referred to as the grain boundary energy distribution (GBED­20]. The first comprehensive measurement of the grain boundary energy distribution was carried out for Mg

Rohrer, Gregory S.

43

Influence of the grain size on deleterious phase precipitation in superduplex stainless steel UNS S32750  

SciTech Connect

In the present work, the effect of grain size on deleterious phase precipitation in a superduplex stainless steel was investigated. The materials studied were heat treated isothermally at 800 deg. C, 850 deg. C and 900 deg. C for times up to 120 min. Hardness tests, light optical microscopy, scanning electron microscopy and X-ray diffraction were carried out to detect sigma and other harmful precipitate phases. The ferritic and austenitic grain sizes in the solution treated condition of the two steels analyzed were measured by electron backscattered diffraction (EBSD). Cyclic polarization corrosion tests were performed to evaluate the effect of grain size on the corrosion resistance. The results presented show that the precipitation of deleterious phases such as {chi}, {sigma} and {gamma}{sub 2}, which can occur during welding and forming operations, is retarded by grain growth.

Pardal, J.M. [Universidade Federal Fluminense, Departamento de Engenharia Mecanica, Rua Passo da Patria, 156-CEP 24210-240, Niteroi/Brazil (Brazil); Tavares, S.S.M. [Universidade Federal Fluminense, Departamento de Engenharia Mecanica, Rua Passo da Patria, 156-CEP 24210-240, Niteroi/Brazil (Brazil)], E-mail: ssmtavares@terra.com.br; Fonseca, M. Cindra; Souza, J.A. de; Corte, R.R.A. [Universidade Federal Fluminense, Departamento de Engenharia Mecanica, Rua Passo da Patria, 156-CEP 24210-240, Niteroi/Brazil (Brazil); Abreu, H.F.G. de [Universidade Federal do Ceara, Departamento de Engenharia Metalugica e de Materiais, Campus do Pici Bl. 702, Fortaleza, CE, CEP 60.455-760 (Brazil)

2009-03-15T23:59:59.000Z

44

The Distribution of Cloud Horizontal Sizes  

Science Conference Proceedings (OSTI)

Cloud horizontal size distributions from near-global satellite data, from aircraft, and from a global high-resolution numerical weather prediction model, are presented for the scale range 0.1–8000 km and are shown to be well-represented using a ...

Robert Wood; Paul R. Field

2011-09-01T23:59:59.000Z

45

The Sampling Variations of Hailstone Size Distributions  

Science Conference Proceedings (OSTI)

The use of a shifted gamma size distribution for hailstone samples is proposed. This is shown to provide a better fit than the usual exponential form, using time-resolved Alberta data. It is also concluded that there is a dependence of the shape ...

Raymond K. W. Wong; Norman Chidambaram; Lawrence Cheng; Marianne English

1988-03-01T23:59:59.000Z

46

Microstructure of TRISO Coated Particles from the AGR-1 Experiment I: SiC Grain Size and Grain Boundary Character  

SciTech Connect

Pre-irradiation SiC microstructures in TRISO coated fuel particles from the AGR-1 experiment were quantitatively characterized using electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). From EBSD it was determined that only the cubic polymorph of as-deposited SiC was present and the SiC had a high fraction of CSL S3 grain boundaries. Additionally, the local area misorientation (LAM), which is a qualitative measurement of strain in the SiC lattice, was mapped for each fuel variant. The morphology of the SiC / IPyC interfaces were characterized by TEM following site-specific focused ion beam (FIB) specimen preparation. It was determined that the SiC layer had a heavily faulted microstructure typical of CVD deposited SiC and that the average grain diameter increased from the SiC/IPyC interface for all the fuel variants, except V3 that showed a constant grain size across the layer.

Rita Kirchhofer; John D, Hunn; Paul A. Demkowicz; James I. Cole; Brian P. Gorman

2013-01-01T23:59:59.000Z

47

City Size Distributions For India and China  

E-Print Network (OSTI)

This paper studies the size distributions of urban agglomerations for India and China. We have estimated the scaling exponent for the Zipf's law with the Indian census data for the years of 1981-2001 and the Chinese census data for 1990 and 2000. Along with the biased linear fit estimate, the maximum likelihood estimate for the Pareto and Tsallis q-exponential distribution has been computed. For India, the scaling exponent is in the range of [1.88, 2.06] and for China, it is in the interval [1.82, 2.29]. The goodness-of-fit tests of the estimated distributions are performed using the Kolmogorov-Smirnov statistic.

Gangopadhyay, Kausik

2010-01-01T23:59:59.000Z

48

Dust negative ion acoustic shock waves considering dust size distribution effect  

Science Conference Proceedings (OSTI)

A multi-ion dusty plasma containing hot isothermal electrons, ions (light positive ions and heavy negative ions), and extremely and negatively charged dust grains is studied in the present paper. The dust negative ion acoustic shock waves have been investigated by employing the reductive perturbation method. How the dust size distribution affects the height and the thickness of the nonlinear shock wave is studied. It is noted that the different dust size distribution has different shock wave form and different moving speed.

Ma Yirong; Wang Canglong; Zhang Jianrong; Sun Jianan; Duan Wenshan [College of Physics and Electronic Engineering and Joint Laboratory of Atomic and Molecular Physics of NWNU and IMP CAS, Northwest Normal University, Lanzhou 730070, China and Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Yang Lei [College of Physics and Electronic Engineering and Joint Laboratory of Atomic and Molecular Physics of NWNU and IMP CAS, Northwest Normal University, Lanzhou 730070 (China) and Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Department of Physics, Lanzhou University, Lanzhou 730000 (China)

2012-11-15T23:59:59.000Z

49

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

Science Conference Proceedings (OSTI)

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

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

2012-10-01T23:59:59.000Z

50

Parameterizing Size Distribution in Ice Clouds  

SciTech Connect

PARAMETERIZING SIZE DISTRIBUTIONS IN ICE CLOUDS David L. Mitchell and Daniel H. DeSlover ABSTRACT An outstanding problem that contributes considerable uncertainty to Global Climate Model (GCM) predictions of future climate is the characterization of ice particle sizes in cirrus clouds. Recent parameterizations of ice cloud effective diameter differ by a factor of three, which, for overcast conditions, often translate to changes in outgoing longwave radiation (OLR) of 55 W m-2 or more. Much of this uncertainty in cirrus particle sizes is related to the problem of ice particle shattering during in situ sampling of the ice particle size distribution (PSD). Ice particles often shatter into many smaller ice fragments upon collision with the rim of the probe inlet tube. These small ice artifacts are counted as real ice crystals, resulting in anomalously high concentrations of small ice crystals (D < 100 ”m) and underestimates of the mean and effective size of the PSD. Half of the cirrus cloud optical depth calculated from these in situ measurements can be due to this shattering phenomenon. Another challenge is the determination of ice and liquid water amounts in mixed phase clouds. Mixed phase clouds in the Arctic contain mostly liquid water, and the presence of ice is important for determining their lifecycle. Colder high clouds between -20 and -36 oC may also be mixed phase but in this case their condensate is mostly ice with low levels of liquid water. Rather than affecting their lifecycle, the presence of liquid dramatically affects the cloud optical properties, which affects cloud-climate feedback processes in GCMs. This project has made advancements in solving both of these problems. Regarding the first problem, PSD in ice clouds are uncertain due to the inability to reliably measure the concentrations of the smallest crystals (D < 100 ”m), known as the “small mode”. Rather than using in situ probe measurements aboard aircraft, we employed a treatment of ice cloud 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 ”m wavelength relative to 11 ”m wavelength due to the process of wave resonance or photon tunneling more active at 12 ”m. This makes the 12/11 ”m absorption optical depth ratio (or equivalently the 12/11 ”m 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.

DeSlover, Daniel; Mitchell, David L.

2009-09-25T23:59:59.000Z

51

Pore size distribution and accessible pore size distribution in bituminous coals  

Science Conference Proceedings (OSTI)

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.

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

2012-01-01T23:59:59.000Z

52

Particle size distributions of ground corn and DDGS from dry grind processing  

E-Print Network (OSTI)

ABSTRACT. Ethanol production has increased in the past decade as a result of growth in the dry grind industry. In the dry grind process, the first step is grinding of corn. The particle size of the resulting ground corn can affect the fermentation process and the particle size of dried distillers ’ grains with solubles (DDGS), a coproduct of dry grind processing. Few data are available that characterize particle size distributions of ground corn or DDGS. The objective was to determine particle size distributions of ground corn and DDGS. Samples of ground corn and DDGS were obtained from nine dry grind plants; particle size distribution, geometric mean diameter (dgw) and geometric standard deviation (Sgw) were determined. The dgw of ground corn and of DDGS were not different among processing plants. The overall mean dgw of ground corn was not different from that of DDGS. Most of the ground corn (80 g/100 g) and DDGS (70 g/100 g) were recovered in the three largest particle size categories. The particle size distributions of ground corn were not correlated (r Corn, DDGS, Distillers dried grains with solubles, Ethanol. Corn is processed into ethanol by one of two major processes: dry grinding or wet milling. Wet milling is more complex than dry grinding because fiber and germ components are separated; this requires considerable equipment and capital. In the dry grind process,

K. D. Rausch; R. L. Belyea; M. R. Ellersieck; V. Singh; D. B. Johnston; M. E. Tumbleson

2005-01-01T23:59:59.000Z

53

The effect of stellar evolution on SiC dust grain sizes  

E-Print Network (OSTI)

Stars on the asymptotic giant branch (AGB) produce dust in their circumstellar shells. The nature of the dust-forming environment is influenced by the evolution of the stars, in terms of both chemistry and density, leading to an evolution in the nature of the dust that is produced. Carbon-rich AGB stars are known to produce silicon carbide (SiC). Furthermore, observations of the ~11um SiC feature show that the spectral features change in a sequence that correlates with stellar evolution. We present new infrared spectra of amorphous SiC and show that the ~9um feature seen in both emission and absorption, and correlated with trends in the ~11um feature, may be due to either amorphous SiC or to nano-crystalline diamond with a high proportion of Si substituting for C. Furthermore, we identify SiC absorption in three ISO spectra of extreme carbon stars, in addition to the four presented by Speck et al. (1997). An accurate description of the sequence in the IR spectra of carbon stars requires accounting for both SiC emission and absorption features. This level of detail is needed to infer the role of dust in evolution of carbon stars. Previous attempts to find a sequence in the infrared spectra of carbon stars considered SiC emission features, while neglecting SiC absorption features, leading to an interpretation of the sequence inadequately describes the role of dust. We show that the evolutionary sequence in carbon star spectra is consistent with a grain size evolution, such that dust grains get progressively smaller as the star evolves. The evolution of the grain sizes provides a natural explanation for the shift of the ~11um SiC feature in emission and in absorption. Further evidence for this scenario is seen in both post-AGB star spectra and in meteoritic studies of presolar grains.

Angela Speck; Grant Thompson; Anne Hofmeister

2005-08-04T23:59:59.000Z

54

The Effect of Grain Size and Phosphorous-doping of Polycrystalline 3C-SiC on Infrared Reflectance Spectra  

SciTech Connect

The effect of P-doping and grain size of polycrystalline 3C-SiC on the infrared reflectance spectra is reported. The relationship between grain size and full width at half maximum (FWHM) suggest that the behaviour of the 3C-SiC with the highest phosphorous doping level (of 1.2 x 10{sup 19} at. cm{sup -3}) is different from those with lower doping levels (< 6.6 x 10{sup 18} at. cm{sup -3}). It is also further demonstrated that the plasma resonance frequency (w{sub p}) is not influenced by the grain size.

I. J. van Rooyen; J. A. A. Engelbrecht; A. Henry; E. Janzen; J. H. Neethling; P. M. van Rooyen

2012-03-01T23:59:59.000Z

55

Characterization of the Grain-Boundary Character and Energy Distributions of Yttria Using Automated Serial Sectioning and  

E-Print Network (OSTI)

Characterization of the Grain-Boundary Character and Energy Distributions of Yttria Using Automated (GBCD) and grain-boundary energy distribution (GBED). The GBCD de- rived from the three-dimensional data- entation parameters.10 In parallel with the GBCD, one can define the grain-boundary energy distribution

Rohrer, Gregory S.

56

Triple Junction Distributions in Grain Boundary Engineered Alloys  

Science Conference Proceedings (OSTI)

A triple junction distribution function for junctions with at least one coherent ... Strain Gradient and Degradation in Magnetic Properties: Focus Transformer Steel.

57

Particle Size Distribution Model for Leaching Kinetics of Alumina  

Science Conference Proceedings (OSTI)

Presentation Title, Particle Size Distribution Model for Leaching Kinetics of Alumina. Author(s), Li Bao, Ting-an Zhang, Weimin Long, Anh V Nguyen, Guozhi Lv, ...

58

Influence of Powder Particle Size Distribution and Pressure on the ...  

Science Conference Proceedings (OSTI)

during HIP were determined as a function of applied pressure, temperature and initial powder particle size distribution for the nickel base superalloy. RENE 95.

59

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

NLE Websites -- All DOE Office Websites (Extended Search)

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

60

Evolution of droplet size distribution and autoconversion parameteriza...  

NLE Websites -- All DOE Office Websites (Extended Search)

Evolution of droplet size distribution and autoconversion parameterization in turbulent clouds McGraw, Robert Brookhaven National Laboratory Liu, Yangang Brookhaven National...

Note: This page contains sample records for the topic "grain size distribution" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

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

E-Print Network (OSTI)

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 ...

Nham, John (John T.)

2008-01-01T23:59:59.000Z

62

Bounds on distance distributions in codes of known size  

Science Conference Proceedings (OSTI)

We treat the problem of bounding components of the possible distance distributions of codes given the knowledge of their size and possibly minimum distance. Using the Beckner inequality from harmonic analysis, we derive upper bounds on distance distribution ...

A. E. Ashikhmin; G. D. Cohen; M. Krivelevich; S. N. Litsyn

2005-01-01T23:59:59.000Z

63

Examination of the ?–? Relation Suggested for Drop Size Distribution Parameters  

Science Conference Proceedings (OSTI)

Raindrop size distributions are often assumed to follow a three-parameter gamma distribution. Since rain intensity retrieval from radar observations is an underdetermined problem, there is great interest in finding physical correlations between ...

Dmitri N. Moisseev; V. Chandrasekar

2007-05-01T23:59:59.000Z

64

Effect of Magnetic Field Applied During Secondary Annealing on Texture and Grain size of Silicon Steel.  

E-Print Network (OSTI)

,2,3]. Grain Non-oriented silicon steels (GNO) are commonly used in hydroelectric power plant generators, Magnetic Annealing, Texture, Grain Growth. #12;1. Introduction Silicon steel is a soft magnetic material, is produced as a consequence of grain boundary migration during recovery, recrystallization, and grain growth

65

The Bias in Moment Estimators for Parameters of Drop Size Distribution Functions: Sampling from Exponential Distributions  

Science Conference Proceedings (OSTI)

The moment estimators frequently used to estimate parameters for drop size distribution (DSD) functions being “fitted” to observed raindrop size distributions are biased. Consequently, the fitted functions often do not represent well either the ...

Paul L. Smith; Donna V. Kliche

2005-08-01T23:59:59.000Z

66

Productivity and Firm Size Distribution: Evidence from India's Organized and Unorganized Manufacturing Sectors  

E-Print Network (OSTI)

Size Distribution - Credit, Electricity, and Labor Reg-Change in Employment Size Distribution Electricity SurplusChange in Employment Size Distribution Electricity Surplus

Nataraj, Shanthi

2010-01-01T23:59:59.000Z

67

Optimal selection and sizing of distributed energy resources for distributed power systems  

Science Conference Proceedings (OSTI)

Optimal selection and sizing of distributed energy resources is an important research problem in the development of distributed power systems. This paper presents a methodology for optimal selection and sizing of distributed energy resources in integrated microgrids using the evolutionary strategy. Integrated microgrid is an innovative architecture in distributed power systems

Thillainathan Logenthiran; Dipti Srinivasan

2012-01-01T23:59:59.000Z

68

Evolution of Solute-structuring and Grain-size in Hierarchy ...  

Science Conference Proceedings (OSTI)

... encounter spectroscopic beam convolutions from multiple nanocrystalline grains within a specimen that makes complete information retrieval challenging.

69

Distribution of Carbide Particles and Its Influence on Grain Growth of ...  

Science Conference Proceedings (OSTI)

In this study this problem is addressed experimentally; the number and size ... Development of Multi-modal 3D Characterization Systems to Quantify Grain ... P1 -04: 3D Microstructural Characterization of Uranium Oxide as a Surrogate Nuclear ... P2-27: Characterization of Carbonate Rocks through X-ray Microtomography.

70

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

SciTech Connect

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.

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

71

Statistical Tools for Drop Size Distributions: Moments and Generalized Gamma  

Science Conference Proceedings (OSTI)

Several problems associated with drop size distributions are treated. For rainfall rate R or radar reflectivity Z high powers of the drop diameters must be taken into account. This paper suggests methods to deal with the relevant moments and to ...

A. N. Aufder Maur

2001-02-01T23:59:59.000Z

72

Cloud Droplet Size Distributions in Low-Level Stratiform Clouds  

Science Conference Proceedings (OSTI)

A database of stratus cloud droplet (diameter <50 ?m) size distribution parameters, derived from in situ data reported in the existing literature, was created, facilitating intercomparison among datasets and quantifying typical values and their ...

Natasha L. Miles; Johannes Verlinde; Eugene E. Clothiaux

2000-01-01T23:59:59.000Z

73

Raindrop Size Distributions and the Radar Bright Band  

Science Conference Proceedings (OSTI)

The relationship between raindrop size distribution, measured with a disdrometer, and a radar parameter of the melting-layer bright band is investigated. The data, obtained in July 1993 in Switzerland, cover 120 h of precipitation. A good ...

A. Huggel; W. Schmid; A. Waldvogel

1996-10-01T23:59:59.000Z

74

The Measurement of Bubble-Size Distributions by Acoustical Backscatter  

Science Conference Proceedings (OSTI)

A multifrequency acoustical-backscatter technique is described for determining the size distribution of bubbles with radii between 8 and 130 ”m. The method makes use of the resonance in the microbubbles and operates at six frequencies ranging ...

Svein Vagle; David M. Farmer

1992-10-01T23:59:59.000Z

75

Hailstone Size Distributions and Their Relationship to Storm Thermodynamics  

Science Conference Proceedings (OSTI)

From ten storms, 184 time-resolved hailstone samples have been collected at the ground in Alberta. For each of the samples collected, hailstone size and concentration were determined and a truncated exponential distribution was fitted to the ...

L. Cheng; M. English; R. Wong

1985-10-01T23:59:59.000Z

76

Statistical Characteristics of Raindrop Size Distribution in Southwest Monsoon Season  

Science Conference Proceedings (OSTI)

Raindrop size distribution (DSD) parameters are retrieved from dual-frequency (UHF and VHF) wind profiler measurements made at Gadanki, India, in a summer monsoon season. The convoluted UHF spectra are first corrected for vertical air motion and ...

N. V. P. Kirankumar; T. Narayana Rao; B. Radhakrishna; D. Narayana Rao

2008-02-01T23:59:59.000Z

77

Measurement of Raindrop Size Distributions Using a Small Doppler Radar  

Science Conference Proceedings (OSTI)

A small X-band bistatic Doppler radar originally developed for use in automated weather stations as a Precipitation Occurrence Sensor System (POSS) can also measure real time raindrop size distributions. In contrast to large-scale pulsed Doppler ...

Brian E. Sheppard

1990-04-01T23:59:59.000Z

78

Use of an Ultrasonic Sodar to Sense Raindrop Size Distributions  

Science Conference Proceedings (OSTI)

The design of a sodar that uses ultrasound to remotely sense drop size distributions in rainfall is described. The Doppler shift is proportional to a drop's terminal velocity and gives a measure of the drop diameter, whereas the intensity of ...

Stuart Bradley; Tracey Webb

2002-08-01T23:59:59.000Z

79

The Development of Drop Size Distributions in Light Rain  

Science Conference Proceedings (OSTI)

A model of rain development based on the quasi-stochastic coalescence equation and including the sedimentation of drops has been used to study the formation of drop size distributions in conditions of weak updraft. Comparisons with “box model” ...

I. Zawadzki; E. Monteiro; F. Fabry

1994-04-01T23:59:59.000Z

80

Some Factors Affecting the Size Distributions of Oceanic Bubbles  

Science Conference Proceedings (OSTI)

The effects of water temperature, dissolved gas saturation levels, and particulate concentrations on the size distribution of subsurface bubbles are investigated using numerical models. The input of bubbles, either at a constant rate in a “steady-...

S. A. Thorpe; P. Bowyer; D. K. Woolf

1992-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "grain size distribution" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Comparison of Polarimetric Radar Drop Size Distribution Retrieval Algorithms  

Science Conference Proceedings (OSTI)

Recently, two physically based algorithms, the “beta” (?) method and the “constrained-gamma” method, have been proposed for retrieving the governing parameters of the gamma drop size distribution (DSD) from polarimetric radar measurements. The ? ...

Edward A. Brandes; Guifu Zhang; J. Vivekanandan

2004-04-01T23:59:59.000Z

82

Raindrop Size Distribution and Radar Parameters at Cape Verde  

Science Conference Proceedings (OSTI)

Precipitation measurement using passive or active microwaves from space- or ground-based radar involves hypotheses about the raindrop size distribution (DSD). A universal knowledge of DSD characteristics is needed. A 4-yr dataset collected with a ...

Armand Nzeukou; Henri Sauvageot; Abe Delfin Ochou; Cheikh Mouhamed Fadel Kebe

2004-01-01T23:59:59.000Z

83

Optimal Siting and Sizing of Distributed Energy Resources  

NLE Websites -- All DOE Office Websites (Extended Search)

Optimal Siting and Sizing of Distributed Energy Resources Optimal Siting and Sizing of Distributed Energy Resources Speaker(s): Johan Driesen Date: February 15, 2007 - 12:00pm Location: 90-3122 Seminar Host/Point of Contact: Chris Marnay Ongoing changes in the operation of distribution grids call for a new way to plan grid modifications. This presentation gives an overview of possible methods of long-term planning for the deployment of Distributed Energy Resources (distributed generation, storage and controllable loads) in a given grid. The placement and sizing of the units have to be considered, making this a complex optimization problem with discrete and continuous variables. In the optimization problem, multiple objectives are often conflicting, e.g. minimal grid losses, maximal use of the resources and voltage stability. An evolutionary algorithm (genetic algorithms) is used

84

Comparison of Raindrop Size Distribution Measurements by Collocated Disdrometers  

Science Conference Proceedings (OSTI)

An impact-type Joss–Waldvogel disdrometer (JWD), a two-dimensional video disdrometer (2DVD), and a laser optical OTT Particle Size and Velocity (PARSIVEL) disdrometer (PD) were used to measure the raindrop size distribution (DSD) over a 6-month ...

Ali Tokay; Walter A. Petersen; Patrick Gatlin; Matthew Wingo

2013-08-01T23:59:59.000Z

85

Methods to determine the size distribution of airborne rhinovirus  

NLE Websites -- All DOE Office Websites (Extended Search)

Methods to determine the size distribution of airborne rhinovirus Methods to determine the size distribution of airborne rhinovirus Title Methods to determine the size distribution of airborne rhinovirus Publication Type Report Year of Publication 2004 Authors Russell, Marion L., Regine Goth-Goldstein, Michael G. Apte, and William J. Fisk Publisher Lawrence Berkeley National Laboratory Abstract About 50% of viral-induced respiratory illnesses are caused by the human rhinovirus (HRV). Prior research has demonstrated that rhinovirus infections can be transmitted via person-to-person contact and via inhalation of infectious aerosols. Measurements of the concentrations and sizes of bioaerosols are critical for research on building characteristics, aerosol transport, and mitigation measures. To detect airborne HRV, we developed a quantitative reverse transcription-coupled polymerase chain reaction (RT-PCR) assay and verified that this assay detects HRV in nasal lavage samples. A quantitation standard was used to determine the assay detection limit of 5 fg of HRV RNA with a linear range over 10,000-fold. This assay was used to quantify the size distribution of an artificially-produced HRV aerosol captured with an Andersen six-stage cascade impactor. In future studies, we hope to use the methods developed here to characterize the size distribution of naturally occurring viral-aerosols

86

Method for measuring the size distribution of airborne rhinovirus  

NLE Websites -- All DOE Office Websites (Extended Search)

Method for measuring the size distribution of airborne rhinovirus Method for measuring the size distribution of airborne rhinovirus Title Method for measuring the size distribution of airborne rhinovirus Publication Type Conference Proceedings Year of Publication 2002 Authors Russell, Marion L., Regine Goth-Goldstein, Michael G. Apte, and William J. Fisk Conference Name Proceedings of the Indoor Air 2002 Conference, Monterey, CA Volume 1 Pagination 40-45 Publisher Indoor Air 2002, Santa Cruz, CA Abstract 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

87

Friction Stir Processing of Ti-6Al-4V for Grain Size Reduction in ...  

Science Conference Proceedings (OSTI)

In Ti alloys, such as Ti-6Al-4V, fusion welding results in coarse-grained microstructure ... Friction Stir Spot Welding of Magnesium to Aluminum Alloys with a Cold ...

88

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

SciTech Connect

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.

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

2009-01-01T23:59:59.000Z

89

Free energy and size distributions of micelles in solution  

Science Conference Proceedings (OSTI)

This paper presents a new derivation of the free energy of micellar solutions. From this free energy a micelle size distribution can be calculated. By using a density functional model for the bulk contribution to the free energy and a simple approximation for the micelle (proper) contribution

P. S. Christopher; David W. Oxtoby

2003-01-01T23:59:59.000Z

90

Aerosol Size Distributions from Genetic Inversion of Polar Nephelometer Data  

Science Conference Proceedings (OSTI)

It is shown that genetic inversions can be used to recover lognormal aerosol size distributions from multiangle optical scattering cross-section data measured by a polar nephelometer at a wavelength of 0.532 ?m. The inversions can also be used to ...

B. R. Lienert; J. N. Porter; S. K. Sharma

2003-10-01T23:59:59.000Z

91

Particle-Size-Distribution of Nevada Test Site Soils  

SciTech Connect

The amount of each size particle in a given soil is called the particle-size distribution (PSD), and the way it feels to the touch is called the soil texture. Sand, silt, and clay are the three particle sizes of mineral material found in soils. Sand is the largest sized particle and it feels gritty; silt is medium sized and it feels floury; and clay is the smallest and if feels sticky. Knowing the particle-size distribution of a soil sample helps to understand many soil properties such as how much water, heat, and nutrients the soil will hold, how fast water and heat will move through the soil, and what kind of structure, bulk density and consistence the soil will have. Furthermore, the native particle-size distribution of the soil in the vicinity of ground zero of a nuclear detonation plays a major role in nuclear fallout. For soils that have a high-sand content, the near-range fallout will be relatively high and the far-range fallout will be relatively light. Whereas, for soils that have a high-silt and high-clay content, the near-range fallout will be significantly lower and the far-range fallout will be significantly higher. As part of a program funded by the Defense Threat Reduction Agency (DTRA), the Lawrence Livermore National Laboratory (LLNL) has recently measured the PSDs from the various major areas at the Nevada Test Site where atmospheric detonations and/or nuclear weapon safety tests were performed back in the 50s and 60s. The purpose of this report is to document those results.

Spriggs, G; Ray-Maitra, A

2007-09-17T23:59:59.000Z

92

Influence of Particle Size Distribution on Random Close Packing  

E-Print Network (OSTI)

The densest amorphous packing of rigid particles is known as random close packing. It has long been appreciated that higher densities are achieved by using collections of particles with a variety of sizes. The variety of sizes is often quantified by the polydispersity of the particle size distribution: the standard deviation of the radius divided by the mean radius. Several prior studies quantified the increase of the packing density as a function of polydispersity. Of course, a particle size distribution is also characterized by its skewness, kurtosis, and higher moments, but the influence of these parameters has not been carefully quantified before. In this work, we numerically generate many packings with different particle radii distributions, varying polydispersity and skewness independently of one another. We find two significant results. First, the skewness can have a significant effect on the packing density and in some cases can have a larger effect than polydispersity. Second, the packing fraction is relatively insensitive to the value of the kurtosis. We present a simple empirical formula for the value of the random close packing density as a function of polydispersity and skewness.

Kenneth W. Desmond; Eric R. Weeks

2013-03-19T23:59:59.000Z

93

Time Evolution of the Mutual Fund Size Distribution  

E-Print Network (OSTI)

We investigate the process of mutual fund growth both empirically and theoretically. The size of large mutual funds has a heavy tailed distribution that has been conjectured to be a power law; we investigate the data more carefully and show that it is better described by a log normal. To explain this we develop a stochastic growth model based on multiplicative growth, creation and annihilation. Under the simplifying assumption that these processes do not depend on fund size we obtain a time-dependent analytic solution of the model. The distribution evolves from a log normal into a power law only over long time scales, suggesting that log-normality comes about because the industry is still young and in a transient state due to its rapid growth in recent years. We make the model more realistic by taking into account size dependent effects, in particular the decay in the rates of diffusion and drift with increasing fund size. The resulting model is in good quantitative agreement with the data. Surprisingly, it a...

Schwarzkopf, Yonathan

2008-01-01T23:59:59.000Z

94

SIZE DISTRIBUTIONS OF SOLAR FLARES AND SOLAR ENERGETIC PARTICLE EVENTS  

Science Conference Proceedings (OSTI)

We suggest that the flatter size distribution of solar energetic proton (SEP) events relative to that of flare soft X-ray (SXR) events is primarily due to the fact that SEP flares are an energetic subset of all flares. Flares associated with gradual SEP events are characteristically accompanied by fast ({>=}1000 km s{sup -1}) coronal mass ejections (CMEs) that drive coronal/interplanetary shock waves. For the 1996-2005 interval, the slopes ({alpha} values) of power-law size distributions of the peak 1-8 A fluxes of SXR flares associated with (a) >10 MeV SEP events (with peak fluxes {>=}1 pr cm{sup -2} s{sup -1} sr{sup -1}) and (b) fast CMEs were {approx}1.3-1.4 compared to {approx}1.2 for the peak proton fluxes of >10 MeV SEP events and {approx}2 for the peak 1-8 A fluxes of all SXR flares. The difference of {approx}0.15 between the slopes of the distributions of SEP events and SEP SXR flares is consistent with the observed variation of SEP event peak flux with SXR peak flux.

Cliver, E. W. [Space Vehicles Directorate, Air Force Research Laboratory, Sunspot, NM 88349 (United States); Ling, A. G. [Atmospheric Environmental Research, Lexington, MA 02421 (United States); Belov, A. [IZMIRAN, Troitsk, Moscow Region 142190 (Russian Federation); Yashiro, S. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2012-09-10T23:59:59.000Z

95

The Bias and Error in Moment Estimators for Parameters of Drop Size Distribution Functions: Sampling from Gamma Distributions  

Science Conference Proceedings (OSTI)

This paper complements an earlier one that demonstrated the bias in the method-of-moments (MM) estimators frequently used to estimate parameters for drop size distribution (DSD) functions being “fitted” to observed raindrop size distributions. ...

Paul L. Smith; Donna V. Kliche; Roger W. Johnson

2009-10-01T23:59:59.000Z

96

Measurements of Gas Bubble Size Distributions in Flowing Liquid Mercury  

Science Conference Proceedings (OSTI)

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.

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

2012-01-01T23:59:59.000Z

97

Doppler Polarimetric Radar Measurements of the Gamma Drop Size Distribution of Rain  

Science Conference Proceedings (OSTI)

The conversion of radar reflections into rain intensities is dependent upon assumptions regarding the drop size distribution. The gamma drop size distribution contains three unknown parameters; the number of parameters that can be obtained ...

H. W. J. Russchenberg

1993-12-01T23:59:59.000Z

98

Dielectric Properties and Depoling Characteristics of Pb(Zr(0.95)Ti(0.05))O(3) Based Ceramics: Near-Critical Grain Size Behavior  

Science Conference Proceedings (OSTI)

Chemically prepared Pb(Zr{sub 0.951}Ti{sub 0.949}){sub 0.982}Nb{sub 0.018}O{sub 3} ceramics were fabricated that were greater than 95% dense for sintering temperatures as low as 925 C. Achieving high density at low firing temperatures permitted isolation of the effects of grain size, from those due to porosity, on both dielectric and pressure induced transformation properties. Specifically, two samples of similar high density, but with grain sizes of 0.7 {micro}m and 8.5 {micro}m, respectively, were characterized. The hydrostatic ferroelectric (FE) to antiferroelectric (AFE) transformation pressure was substantially less (150 MPa) for the lower grain size material than for the larger grain size material. In addition, the dielectric constant increased and the Curie temperature decreased for the sample with lower grain size. All three properties: dielectric constant magnitude, Curie point shift, and FE to AFE phase transformation pressure were shown to be semi-quantitatively consistent with internal stress levels on the order of 100 MPa.

RODRIGUEZ,MARK A.; SCOFIELD,TIMOTHY W.; TUTTLE,BRUCE A.; VOIGT,JAMES A.; YANG,PIN; ZEUCH,DAVID H.

1999-09-30T23:59:59.000Z

99

Estimation of Gamma Raindrop Size Distribution Parameters: Statistical Fluctuations and Estimation Errors  

Science Conference Proceedings (OSTI)

The gamma distribution is often used to characterize raindrop size distributions (DSDs). However, the estimation of measured raindrop distributions suffers from the shortcomings of statistical sampling errors, which become increasingly ...

Cécile Mallet; Laurent Barthes

2009-08-01T23:59:59.000Z

100

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

SciTech Connect

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

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

2011-09-10T23:59:59.000Z

Note: This page contains sample records for the topic "grain size distribution" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Pressure Induced Phase Transformation of Pb(Zr(0.95)Ti(0.05))O(3) Based Ceramics: Grain Size Dependence  

Science Conference Proceedings (OSTI)

A substantial decrease in hydrostatic ferroelectric (FE) to antiferroelectric (AFE) transformation pressure was measured for Pb(Zr{sub 0.949}Ti{sub 0.051}){sub 0.989}Nb{sub 0.0182}O{sub 3} ceramics with decreasing grain size. The 150 MPa decrease in hydrostatic FE to AFE transformation pressure over the grain size range of 8.5 {micro}m to 0.7{micro}m was shown to be consistent with enhanced internal stress with decreasing grain size. Further, the Curie Point decreased and the dielectric constant measured at 25 C increased with decreasing grain size. All three properties: dielectric constant magnitude, Curie point shift and FE to AFE phase transformation pressure were shown to be semi-quantitatively consistent with internal stress differences on the order of 100 MPa. Calculations of Curie point shifts from the Clausius-Clapeyron equation, using internal stress levels derived from the hydrostatic depoling characteristics, were consistent with measured values.

TUTTLE,BRUCE A.; VOIGT,JAMES A.; SCOFIELD,TIMOTHY W.; ASELAGE,TERRENCE L.; RODRIGUEZ,MARK A.; YANG,PIN; ZEUCH,DAVID H.; OLSON,WALTER R.; SIPOLA,DIANA L.

1999-12-21T23:59:59.000Z

102

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

103

H17: Study of the Grain Size Distribution and Mechanical Properties ...  

Science Conference Proceedings (OSTI)

A18: Effect of Local Alendronate Delivery on In Vivo Osteogenesis From PCL ... A7: On-the-fly System Design for High Precision/Ultra Fast/Wide Area Fabrication .... C19: Dissolution Behavior of Cu Under Bump Metallization in Ball Grid Array ... High Volume and Fast Turnaround Automated Inline TEM Sample Preparation.

104

On the size distribution of Atlantic tropical cyclones  

E-Print Network (OSTI)

The size of a tropical cyclone is known to vary considerably across storms, though little is understood about the environmental and internal factors that modulate it. Making use of newly available extended tropical cyclone ...

Emanuel, Kerry Andrew

105

High-Resolution Measurement of Size Distributions of Asian Dust Using a Coulter Multisizer  

Science Conference Proceedings (OSTI)

A Coulter Multisizer, which is based on the electrical sensing zone (ESZ) or the Coulter principle, was used to measure the size distribution of Asian dust. Coulter Multisizer analysis provides high-resolution size measurements of water-insoluble ...

Hiroshi Kobayashi; Kimio Arao; Toshiyuki Murayama; Kengo Iokibe; Ryuji Koga; Masataka Shiobara

2007-02-01T23:59:59.000Z

106

The Sensitivity of Microwave Remote Sensing Observations of Precipitation to Ice Particle Size Distributions  

Science Conference Proceedings (OSTI)

This study investigates the effect of variable size distribution and density of precipitation ice particles on microwave brightness temperatures. For this purpose, a set of self-consistent relationships among rain rate, size parameters of an ...

Ralf Bennartz; Grant W. Petty

2001-03-01T23:59:59.000Z

107

Size Distribution of Coastal Aerosols: Effects of Local Sources and Sinks  

Science Conference Proceedings (OSTI)

Using aerosol optical depth as a function of wavelength obtained from ground-based multiwavelength radiometer observations, columnar size-distribution functions of aerosols have been derived. It has been found that the nature of the derived size-...

K. Krishna Moorthy; Prabha R. Nair; B. V. Krishna Murthy

1991-06-01T23:59:59.000Z

108

Modeling Raindrop Size Distribution and Z(R) Relations in the Western Mediterranean Area  

Science Conference Proceedings (OSTI)

This study shows the results of the modeling of drop size distributions (DSD) observed during a 2-yr study in Barcelona. Thirty-second individual sample collections of drop sizes and velocities were measured with an optical disdrometer and ...

Carlos Cerro; Bernat Codina; Joan Bech; Jeroni Lorente

1997-11-01T23:59:59.000Z

109

L-Moment Estimators as Applied to Gamma Drop Size Distributions  

Science Conference Proceedings (OSTI)

The traditional approach with experimental raindrop size data has been to use the method of moments in the fitting procedure to estimate the parameters for the raindrop size distribution function. However, the moment method is known to be biased ...

Donna V. Kliche; Paul L. Smith; Roger W. Johnson

2008-12-01T23:59:59.000Z

110

On the Form of Stationary Size Distributions Established by Coagulation and Sedimentation  

Science Conference Proceedings (OSTI)

In stationary solutions of the equations for nucleation, coagulation and sedimentation, the concentration of large particles falls off more strongly than any power of particle size. The tails of stationary size distributions established by these ...

Warren H. White

1983-07-01T23:59:59.000Z

111

Sensitivity of 5-cm Wavelength Polarimetric Radar Variables to Raindrop Axial Ratio and Drop Size Distribution  

Science Conference Proceedings (OSTI)

The sensitivity of polarimetric variables at a 5-cm wavelength to raindrop size and axial ratio is examined using T-matrix modeling of the scattering process for gamma raindrop size distributions fitted to tropical rainfall collected at Darwin, ...

T. D. Keenan; L. D. Carey; D. S. Zrni?; P. T. May

2001-03-01T23:59:59.000Z

112

Distributions of Raindrop Sizes and Fall Velocities in a Semiarid Plateau Climate: Convective versus Stratiform Rains  

Science Conference Proceedings (OSTI)

Joint size and fall velocity distributions of raindrops were measured with a Particle Size and Velocity (PARSIVEL) precipitation particle disdrometer in a field experiment conducted during July and August 2007 at a semiarid continental site ...

Shengjie Niu; Xingcan Jia; Jianren Sang; Xiaoli Liu; Chunsong Lu; Yangang Liu

2010-04-01T23:59:59.000Z

113

A New Mechanism of Droplet Size Distribution Broadening during Diffusional Growth  

Science Conference Proceedings (OSTI)

A new mechanism has been developed for size distribution broadening toward large droplet sizes. This mechanism may explain the rapid formation of large cloud droplets, which may subsequently trigger precipitation formation through the collision–...

Alexei Korolev; Mark Pinsky; Alex Khain

2013-07-01T23:59:59.000Z

114

On the Shape–Slope Relation of Drop Size Distributions in Convective Rain  

Science Conference Proceedings (OSTI)

The relation between the slope and shape parameters of the raindrop size distribution parameterized by a gamma distribution is examined. The comparison of results of a simple rain shaft model with an empirical relation based on disdrometer ...

Axel Seifert

2005-07-01T23:59:59.000Z

115

Natural Variations in the Analytical Form of the Raindrop Size Distribution  

Science Conference Proceedings (OSTI)

Empirical analyses are shown to imply variation in the shape or analytical form of the raindrop size distribution consistent with that observed experimentally and predicted theoretically. These natural variations in distribution shape are ...

Carlton W. Ulbrich

1983-10-01T23:59:59.000Z

116

Measurements of Aerosol Size Distributions in the Lower Troposphere over Northern Europe  

Science Conference Proceedings (OSTI)

Airborne measurements of particle size distributions were made at several altitudes within and above the mixing layer at sites near Ahlhorn and Meppen (West Germany), Rodby (Denmark), and Bruz (France). The distributions were measured over the ...

Bruce W. Fitch; Ted S. Cress

1981-10-01T23:59:59.000Z

117

The Modified Gamma Size Distribution Applied to Inhomogeneous and Nonspherical Particles: Key Relationships and Conversions  

Science Conference Proceedings (OSTI)

The four-parameter modified gamma distribution (MGD) is the most general mathematically convenient model for size distributions of particle types ranging from aerosols and cloud droplets or ice particles to liquid and frozen precipitation. The ...

Grant W. Petty; Wei Huang

2011-07-01T23:59:59.000Z

118

Size Distributions and Dynamical Properties of Shallow Cumulus Clouds from Aircraft Observations and Satellite Data  

Science Conference Proceedings (OSTI)

In this paper aircraft observations of shallow cumulus over Florida during the Small Cumulus Microphysics Study (SCMS) are analyzed. Size distributions of cloud fraction, mass flux, and in-cloud buoyancy flux are derived. These distributions ...

Stefaan M. A. Rodts; Peter G. Duynkerke; Harm J. J. Jonker

2003-08-01T23:59:59.000Z

119

Retrieval of Raindrop Size Distribution from Simulated Dual-Frequency Radar Measurements  

Science Conference Proceedings (OSTI)

Observations of raindrop size distributions (DSDs) have validated the use of three-parameter distribution functions in representing the observed spectra. However, dual-frequency radar measurements are limited to retrieving two independent ...

S. Joseph Munchak; Ali Tokay

2008-01-01T23:59:59.000Z

120

Diagnosing the Intercept Parameter for Exponential Raindrop Size Distribution Based on Video Disdrometer Observations: Model Development  

Science Conference Proceedings (OSTI)

The exponential distribution N(D) = N0 exp(??D) with a fixed intercept parameter N0 is most commonly used to represent raindrop size distribution (DSD) in rainfall estimation and in single-moment bulk microphysics parameterization schemes. ...

Guifu Zhang; Ming Xue; Qing Cao; Daniel Dawson

2008-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "grain size distribution" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

GA based energy loss minimization approach for optimal sizing & placement of distributed generation  

Science Conference Proceedings (OSTI)

Distributed Generators (DG) provide the lowest cost solution to handle low voltage or overload problems. In conjunction with such problems, a technique of energy saving is introduced by placement of distributed generation (DG) in distribution systems. ... Keywords: Distributed generation (DG), energy saving, genetic algorithms (GA), optimal sizing and placement

Deependra Singh; Devender Singh; K. S. Verma

2008-04-01T23:59:59.000Z

122

Experimental Characterization of BORALź Pore Size and Volume Distributions  

Science Conference Proceedings (OSTI)

This study has measured pore size and pore volume of six different production batches of BORAL. The study included production lots that are known for being either blister prone or blister resistant under simulated canister wetting/vacuum drying conditions, or known to form edge blisters while in the spent-fuel pool. Additional production lots for which blister performance is unknown also were tested. Blisters in the cladding of BORAL, if large enough, can deform stainless steel walls in storage racks and...

2010-12-10T23:59:59.000Z

123

Sieveless particle size distribution analysis of particulate materials through computer vision  

Science Conference Proceedings (OSTI)

This paper explores the inconsistency of ''length-based separation'' by mechanical sieving of particulate materials with standard sieves, which is the standard method of particle size distribution (PSD) analysis. We observed inconsistencies of length-based ... Keywords: Biomass sieve analysis, Dimension, Image processing, ImageJ plugin, Particle size distribution, Physical property

C. Igathinathane; L. O. Pordesimo; E. P. Columbus; W. D. Batchelor; S. Sokhansanj

2009-05-01T23:59:59.000Z

124

Aerosol size distribution using Lidar data and a typical Lidar assembly  

Science Conference Proceedings (OSTI)

An algorithm is developed and detailed in this paper which determines atmospheric aerosol parameters such as backscatter and extinction coefficients, aerosol optical thickness, and the aerosol size distribution. The algorithm uses the power profile data ... Keywords: LIDAR system, aerosol optical depth, aerosol size distribution, remote sensing

Hamed Parsiani; Javier Mèndez

2008-11-01T23:59:59.000Z

125

Ant Colony System-Based Algorithm for Optimal Multi-stage Planning of Distribution Transformer Sizing  

Science Conference Proceedings (OSTI)

This paper proposes a stochastic optimization method, based on ant colony optimization, for the optimal choice of transformer sizes to be installed in a distribution network. This method is properly introduced to the solution of the optimal transformer ... Keywords: Ant Colony Optimization, Distribution Network Planning, Energy Loss Cost, Optimal Transformer Sizing, Thermal Loading, Transformers

Eleftherios I. Amoiralis; Pavlos S. Georgilakis; Marina A. Tsili; Antonios G. Kladas

2008-09-01T23:59:59.000Z

126

Journal of Molecular Catalysis A: Chemical 228 (2005) 299307 Complementary methods for cluster size distribution measurements  

E-Print Network (OSTI)

size distribution measurements: supported platinum nanoclusters in methane reforming catalysts J.V. All rights reserved. Keywords: Cluster size; SAXS; XAFS; HRTEM; Methane reforming 1. Introduction cluster size strongly influences the reactivity of surfaces for C H bond activation during CH4 steam

Iglesia, Enrique

127

What is the upper size limit for cosmopolitan distribution in free-living microorganisms?  

E-Print Network (OSTI)

What is the upper size limit for cosmopolitan distribution in free-living microorganisms? ABSTRACT distance apart) is used to try and answer the question `What is the upper size limit for cosmopolitan to 230 lm while the largest cosmopolitan species was 135 lm in size. Comparison of the testate

Brown, Richard

128

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

DOE Patents (OSTI)

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.

Dooley, James H; Lanning, David N

2013-07-30T23:59:59.000Z

129

Siting and sizing of distributed generation units using GA and OPF  

Science Conference Proceedings (OSTI)

This paper deals with the important task of finding the optimal siting and sizing of Distributed Generation (DG) units for a given distribution network so that the cost of active and reactive power generation can be minimized. The optimization technique ... Keywords: distributed generation, genetic alghorithm(GA), optimal power flow(OPF)

M. Hosseini Aliabadi; M. Mardaneh; B. Behbahan

2008-01-01T23:59:59.000Z

130

Physicochemical Characterization of Capstone Depleted Uranium Aerosols II: Particle Size Distributions as a Function of Time  

SciTech Connect

The Capstone Depleted Uranium (DU) Aerosol Study, which generated and characterized aerosols containing depleted uranium from perforation of armored vehicles with large-caliber DU penetrators, incorporated a sampling protocol to evaluated particle size distributions. Aerosol particle size distribution is an important parameter that influences aerosol transport and deposition processes as well as the dosimetry of the inhaled particles. These aerosols were collected on cascade impactor substrates using a pre-established time sequence following the firing event to analyze the uranium concentration and particle size of the aerosols as a function of time. The impactor substrates were analyzed using beta spectrometry, and the derived uranium content of each served as input to the evaluation of particle size distributions. Activity median aerodynamic diameters (AMADs) of the particle size distributions were evaluated using unimodal and bimodal models. The particle size data from the impactor measurements was quite variable. Most size distributions measured in the test based on activity had bimodal size distributions with a small particle size mode in the range of between 0.2 and 1.2 um and a large size mode between 2 and 15 um. In general, the evolution of particle size over time showed an overall decrease of average particle size from AMADs of 5 to 10 um shortly after perforation to around 1 um at the end of the 2-hr sampling period. The AMADs generally decreased over time because of settling. Additionally, the median diameter of the larger size mode decreased with time. These results were used to estimate the dosimetry of inhaled DU particles.

Cheng, Yung-Sung; Kenoyer, Judson L.; Guilmette, Raymond A.; Parkhurst, MaryAnn

2009-03-01T23:59:59.000Z

131

The dune size distribution and scaling relations of barchan dune fields  

E-Print Network (OSTI)

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.

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

2007-01-16T23:59:59.000Z

132

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

DOE Patents (OSTI)

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.

Dooley, James H; Lanning, David N

2013-08-13T23:59:59.000Z

133

Retrieval of Raindrop Size Distributions Using Two Doppler Wind Profilers: Model Sensitivity Testing  

Science Conference Proceedings (OSTI)

The behavior of precipitation is of great importance in obtaining a better understanding of heat transport estimates and global processes in the atmosphere. This paper discusses improvements in an earlier raindrop size distribution model that ...

W. B. Maguire II; S. K. Avery

1994-12-01T23:59:59.000Z

134

Variability of Raindrop Size Distributions in a Squall Line and Implications for Radar Rainfall Estimation  

Science Conference Proceedings (OSTI)

The intrastorm variability of raindrop size distributions as a source of uncertainty in single-parameter and dual-parameter radar rainfall estimates is studied using time series analyses of disdrometer observations. Two rain-rate (R) estimators ...

Remko Uijlenhoet; Matthias Steiner; James A. Smith

2003-02-01T23:59:59.000Z

135

Relationships between the Raindrop Size Distribution and Properties of the Environment and Clouds Inferred from TRMM  

Science Conference Proceedings (OSTI)

Raindrop size distribution (DSD) retrievals from two years of data gathered by the Tropical Rainfall Measuring Mission (TRMM) satellite and processed with a combined radar–radiometer algorithm over the oceans equatorward of 35° are examined for ...

S. Joseph Munchak; Christian D. Kummerow; Gregory Elsaesser

2012-04-01T23:59:59.000Z

136

A Generalized Systems Theory for the Effect of Varying Fluctuations on Cloud Droplet Size Distributions  

Science Conference Proceedings (OSTI)

A systems theory has previously been developed by Liu and Hallett to interpret droplet size distributions in turbulent clouds by utilizing ideas from statistical physics and information theory. The present paper generalizes that systems theory to ...

Yangang Liu; Peter H. Daum; John Hallett

2002-07-01T23:59:59.000Z

137

The Modification of Joint Size-Charge Distribution in Rain. Part II: Computations Involving Partial Coalescence  

Science Conference Proceedings (OSTI)

Raindrop collisional breakup is included in a model of joint size-charge distribution development. Consistent with experimental observations the model includes a finite filament (joining separating drops) that upon rupture produces charged ...

S. G. Bradley; C. D. Stow

1984-10-01T23:59:59.000Z

138

A Preliminary Analysis of Spatial Variability of Raindrop Size Distributions during Stratiform Rain Events  

Science Conference Proceedings (OSTI)

The spatial variability of raindrop size distributions (DSDs) and precipitation fields is investigated utilizing disdrometric measurements from the four Precipitation Occurrence Sensor Systems (POSS) and radar reflectivity fields from S-band dual-...

Choong Ke Lee; Gyu Won Lee; Isztar Zawadzki; Kyung-Eak Kim

2009-02-01T23:59:59.000Z

139

Progress on Predicting the Breadth of Droplet Size Distributions Observed in Small Cumuli  

Science Conference Proceedings (OSTI)

A modeling framework representing variations in droplet growth by condensation, resulting from different saturation histories experienced as a result of entrainment and mixing, is used to predict the breadth of droplet size distributions observed ...

Jennifer L. Bewley; Sonia Lasher-Trapp

2011-12-01T23:59:59.000Z

140

Improvements of Droplet Size Distribution Measurements with the Fast-FSSP (Forward Scattering Spectrometer Probe)  

Science Conference Proceedings (OSTI)

The basics of single particle measurements are discussed and illustrated with measurements of the droplet size distribution with an optical spectrometer, the Forward Scattering Spectrometer Probe (FSSP), and its improved version, the Fast-FSSP. ...

Jean-Louis Brenguier; Thierry Bourrianne; Afraniode Araujo Coelho; Jacques Isbert; Robert Peytavi; Dominique Trevarin; Perry Weschler

1998-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "grain size distribution" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Wind-Induced Error of Raindrop Size Distribution Measurement Using a Two-Dimensional Video Disdrometer  

Science Conference Proceedings (OSTI)

The authors investigate a disdrometer that provides information on raindrop size distribution, terminal velocity, and shape using video imaging technology. Two video cameras are enclosed in a large box and provide images of the passing drops. The ...

Vladislav Nešpor; Witold F. Krajewski; Anton Kruger

2000-11-01T23:59:59.000Z

142

Optimal Determination of Parameters for Gamma-Type Drop Size Distributions Based on Moments  

Science Conference Proceedings (OSTI)

Measured raindrop size distributions are often approximated by analytical functions. The parameters determining such functions are usually derived from measured data. This procedure can suffer from various uncertainties. The most important of ...

Jan Handwerker; Winfried Straub

2011-04-01T23:59:59.000Z

143

Air Entrainment Processes and Bubble Size Distributions in the Surf Zone  

Science Conference Proceedings (OSTI)

A new optical instrument was deployed in the surf zone in a trial experiment to measure bubble size distributions and visualize air entrainment and bubble formation mechanisms within breaking surf. Images of bubbles and the evolving air–water ...

Grant B. Deane; M. Dale Stokes

1999-07-01T23:59:59.000Z

144

Polarimetric Radar Rain Estimation through Retrieval of Drop Size Distribution Using a Bayesian Approach  

Science Conference Proceedings (OSTI)

This study proposes a Bayesian approach to retrieve raindrop size distributions (DSDs) and to estimate rainfall rates from radar reflectivity in horizontal polarization ZH and differential reflectivity ZDR. With this approach, the authors apply a ...

Qing Cao; Guifu Zhang; Edward A. Brandes; Terry J. Schuur

2010-05-01T23:59:59.000Z

145

A Comparison of Techniques to Estimate Vertical Air Motions and Raindrop Size Distributions  

Science Conference Proceedings (OSTI)

Doppler velocity spectra collected at vertical incidence contain information on vertical air motions and drop-size distributions with high spatial and temporal resolution. In the past, the computational interdependence between vertical air ...

Karen L. Sangren; Peter S. Ray; Gene B. Walker

1984-06-01T23:59:59.000Z

146

Intercomparison of Instruments used for Measurement of Cloud Drop Concentration and Size Distribution  

Science Conference Proceedings (OSTI)

Measurements of drop concentration and size distribution with the Clague droplet gun and the Forward Scattering Spectrometer Probe in 21 cumulus clouds on five days show no evidence of systematic differences between the two instruments. Though ...

S. C. Mossop

1983-03-01T23:59:59.000Z

147

Raindrop Size Distribution and Radar Parameters in Coastal Tropical Rain Systems of Northeastern Brazil  

Science Conference Proceedings (OSTI)

A dataset on raindrop size distribution (DSD) gathered in a coastal site of the Alagoas state in northeastern Brazil is used to analyze some differences between continental and maritime rainfall parameters. The dataset is divided into two subsets. ...

Ricardo Sarmento Tenório; Marcia Cristina da Silva Moraes; Henri Sauvageot

2012-11-01T23:59:59.000Z

148

Effects of Drop-Size-Distribution Truncation on Computer Simulations of Dual-Measurement Radar Methods  

Science Conference Proceedings (OSTI)

An investigation is made of the effects of truncating the raindrop-size distribution at minimum and maximum diameters on the results of computer simulations of dual-measurement radar methods. The dual-measurement methods investigated include ...

Carlton W. Ulbrich

1992-07-01T23:59:59.000Z

149

Wavenumber Analysis of Azimuthally Distributed Data: Assessing Maximum Allowable Gap Size  

Science Conference Proceedings (OSTI)

Performing wavenumber decomposition on azimuthally distributed data such as those in tropical cyclones can be challenging when data gaps exist in the signal. In the literature, ad hoc approaches are found to determine maximum gap size beyond which ...

Sylvie Lorsolo; Altu? Aksoy

2012-06-01T23:59:59.000Z

150

A Free-Flooding Acoustical Resonator for Measurement of Bubble Size Distributions  

Science Conference Proceedings (OSTI)

An instrument for the measurement of bubble size distributions is described. The sensing element exploits the free-flooding resonator design of Medwin with modifications to overcome the limitations in the original implementation, especially those ...

David M. Farmer; Svein Vagle; A. Donald Booth

1998-10-01T23:59:59.000Z

151

The Use of Direct Observations over the Aerosol Particle Size Distribution for Inverting Lidar Data  

Science Conference Proceedings (OSTI)

The work is concerned with the inversion of horizontal lidar data into the aerosol particle size distribution (APSD). The aerosol is assumed to consist of spherical particles of continental and oceanic origin. The particular refraction index is ...

Kusiel S. Shifrin; Ilia G. Zolotov

2003-10-01T23:59:59.000Z

152

A Probabilistic View on the Rain Drop Size Distribution Modeling: a Physical Interpretation of Rain Microphysics  

Science Conference Proceedings (OSTI)

The Rain Drop Size Distribution (RDSD) is defined as the relative frequency of raindrops per given diameter in a volume. This paper describes a mathematically-consistent modeling of the RDSD drawing on probability theory. It is shown that this ...

Francisco J. Tapiador; Ziad S. Haddad; Joe Turk

153

Functional Fits to Some Observed Drop Size Distributions and Parameterization of Rain  

Science Conference Proceedings (OSTI)

A data sample of optical spectrometer measurements that were obtained in two tropical cyclones is analyzed. The resultant drop size distributions are normalized and their shape is found to exhibit some curvature-departure from exponentiality. ...

Paul T. Willis

1984-05-01T23:59:59.000Z

154

Modeling the Variability of Drop Size Distributions in Space and Time  

Science Conference Proceedings (OSTI)

The information on the time variability of drop size distributions (DSDs) as seen by a disdrometer is used to illustrate the structure of uncertainty in radar estimates of precipitation. Based on this, a method to generate the space–time ...

Gyu Won Lee; Alan W. Seed; Isztar Zawadzki

2007-06-01T23:59:59.000Z

155

Errors in Estimating Raindrop Size Distribution Parameters Employing Disdrometer and Simulated Raindrop Spectra  

Science Conference Proceedings (OSTI)

There have been debates and differences of opinion over the validity of using drop size distribution (DSD) models to characterize precipitation microphysics and to retrieve DSD parameters from multiparameter radar measurements. In this paper, ...

Qing Cao; Guifu Zhang

2009-02-01T23:59:59.000Z

156

An Investigation of the Slope–Shape Relation for Gamma Raindrop Size Distribution  

Science Conference Proceedings (OSTI)

The gamma drop size distribution (DSD) has been widely used in the meteorological community for years to model observed DSD. It has been found that the relation between the slope (?) and shape (?) parameters of the gamma DSD can be empirically ...

Yen-Hsyang Chu; Ching-Lun Su

2008-10-01T23:59:59.000Z

157

The Shape–Slope Relation in Observed Gamma Raindrop Size Distributions: Statistical Error or Useful Information?  

Science Conference Proceedings (OSTI)

The three-parameter gamma distribution n(D) = N0D” exp(–?D) is often used to characterize a raindrop size distribution (DSD). The parameters ” and ? correspond to the shape and slope of the DSD. If ” and ? are related to one another, as recent ...

Guifu Zhang; J. Vivekanandan; Edward A. Brandes; Robert Meneghini; Toshiaki Kozu

2003-08-01T23:59:59.000Z

158

The Effects of Drop Size Distribution Truncation on Rainfall Integral Parameters and Empirical Relations  

Science Conference Proceedings (OSTI)

A description is given of a method of estimating the effects of truncating the raindrop size distribution (DSD) at lower and upper drop diameters Dmin and Dmax which assumes that the DSD can be approximated by a gamma distribution (including the ...

Carlton W. Ulbrich

1985-06-01T23:59:59.000Z

159

The E ect of Heavy-Tailed Job Size Distributions on Computer System Design.  

E-Print Network (OSTI)

The E ect of Heavy-Tailed Job Size Distributions on Computer System Design. Mor Harchol-Balter Laboratory for Computer Science MIT, NE43-340 Cambridge, MA 02139 harchol@theory.lcs.mit.edu Abstract Heavy physical phenomena to sociological phenomena. Recently heavy-tailed distributions have been discovered

Harchol-Balter, Mor

160

A POSSIBLE DIVOT IN THE SIZE DISTRIBUTION OF THE KUIPER BELT'S SCATTERING OBJECTS  

Science Conference Proceedings (OSTI)

Via joint analysis of a calibrated telescopic survey, which found scattering Kuiper Belt objects, and models of their expected orbital distribution, we explore the scattering-object (SO) size distribution. Although for D > 100 km the number of objects quickly rise as diameters decrease, we find a relative lack of smaller objects, ruling out a single power law at greater than 99% confidence. After studying traditional ''knees'' in the size distribution, we explore other formulations and find that, surprisingly, our analysis is consistent with a very sudden decrease (a divot) in the number distribution as diameters decrease below 100 km, which then rises again as a power law. Motivated by other dynamically hot populations and the Centaurs, we argue for a divot size distribution where the number of smaller objects rises again as expected via collisional equilibrium. Extrapolation yields enough kilometer-scale SOs to supply the nearby Jupiter-family comets. Our interpretation is that this divot feature is a preserved relic of the size distribution made by planetesimal formation, now ''frozen in'' to portions of the Kuiper Belt sharing a ''hot'' orbital inclination distribution, explaining several puzzles in Kuiper Belt science. Additionally, we show that to match today's SO inclination distribution, the supply source that was scattered outward must have already been vertically heated to the of order 10 Degree-Sign .

Shankman, C.; Gladman, B. J. [Department of Physics and Astronomy, University of British Columbia, 6224 Agriculture Road, Vancouver, BC V6T 1Z1 (Canada); Kaib, N. [Department of Physics and Astronomy, Queens University (Canada); Kavelaars, J. J. [National Research Council of Canada, Victoria, BC V9E 2E7 (Canada); Petit, J. M. [Institut UTINAM, CNRS-Universite de Franche-Comte, Besancon (France)

2013-02-10T23:59:59.000Z

Note: This page contains sample records for the topic "grain size distribution" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

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

Science Conference Proceedings (OSTI)

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.

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

2011-11-01T23:59:59.000Z

162

Standard Test Method for Particle Size Distribution of Alumina or Quartz Powders by Electrical Sensing Zone Technique  

E-Print Network (OSTI)

Standard Test Method for Particle Size Distribution of Alumina or Quartz Powders by Electrical Sensing Zone Technique

American Society for Testing and Materials. Philadelphia

1992-01-01T23:59:59.000Z

163

GRAIN SORTING IN COMETARY DUST FROM THE OUTER SOLAR NEBULA  

SciTech Connect

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.

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

164

An Aggregate Model for the Particle Size Distribution in Saturn's Rings  

E-Print Network (OSTI)

Saturn's rings are known to consist of a large number of water ice particles. They form a flat disk, as the result of an interplay of angular momentum conservation and the steady loss of energy in dissipative particle collisions. For particles in the size range from a few centimeters to about a few meters a power law distribution of radii r^(-q), with q = 3, is implied by the light scattering properties of the rings. In contrast, for larger sizes the distribution drops steeply with increasing r. It has been suggested that this size distribution may arise from a balance between aggregation and fragmentation of ring particles, but to date neither the power-law dependence, nor the upper size-cutoff have been explained or quantified within a unique theory. Here we present a new kinetic model for the collisional evolution of the size distribution and show that the exponent q is expected to be constrained to the interval 2.75 < q < 3.5. An exponential cutoff towards larger particle sizes establishes naturally...

Brilliantov, Nikolai; Hayakawa, Hisao; Bodrova, Anna; Spahn, Frank; Schmidt, Juergen

2013-01-01T23:59:59.000Z

165

Infrared Spectra of Meteoritic SiC Grains  

E-Print Network (OSTI)

We present here the first infrared spectra of meteoritic SiC grains. The mid-infrared transmission spectra of meteoritic SiC grains isolated from the Murchison meteorite were measured in the wavelength range 2.5--16.5 micron, in order to make available the optical properties of presolar SiC grains. These grains are most likely stellar condensates with an origin predominately in carbon stars. Measurements were performed on two different extractions of presolar SiC from the Murchison meteorite. The two samples show very different spectral appearance due to different grain size distributions. The spectral feature of the smaller meteoritic SiC grains is a relatively broad absorption band found between the longitudinal and transverse lattice vibration modes around 11.3 micron, supporting the current interpretation about the presence of SiC grains in carbon stars. In contrast to this, the spectral feature of the large (> 5 micron) grains has an extinction minimum around 10 micron. The obtained spectra are compared with commercially available SiC grains and the differences are discussed. This comparison shows that the crystal structure (e.g., beta-SiC versus alpha-SiC) of SiC grains plays a minor role on the optical signature of SiC grains compared to e.g. grain size.

A. C. Andersen; C. Jager; H. Mutschke; A. Braatz; C. Clement; Th. Henning; U. G. Jorgensen; U. Ott

1998-12-22T23:59:59.000Z

166

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

SciTech Connect

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.

Gilbert, Benjamin

2008-10-01T23:59:59.000Z

167

Analysis of Model-Produced Raindrop Size Distributions in the Small-Drop Range  

Science Conference Proceedings (OSTI)

Current models of drop coalescence and breakup generate raindrop size distributions that evolve toward an equilibrium whose form features a pronounced peak in the small-drop range. It has been known for some time that the peak can be attributed ...

Philip S. Brown Jr.

1999-05-01T23:59:59.000Z

168

Minimizing Instrumental Broadening of the Drop Size Distribution with the M-Fast-FSSP  

Science Conference Proceedings (OSTI)

A modified version of the Fast-FSSP (the so-called M-Fast-FSSP) is introduced. It allows minimization of the instrumental broadening of measured cloud drop size distributions caused by laser beam inhomogeneities. This is achieved by applying a ...

Sebastian Schmidt; Katrin Lehmann; Manfred Wendisch

2004-12-01T23:59:59.000Z

169

The Relationship between N0 and ? for Marshall-Palmer Type Raindrop-Size Distributions  

Science Conference Proceedings (OSTI)

For raindrop-size distributions of the form ND = N0e??D, where ND is the number of drops of diameter D per unit volume per unit increment in drop diameter, the parameters N0 and ? cannot be specified independently as functions of rainfall rate R. ...

J. A. Bennett; D. J. Fang; R. C. Boston

1984-05-01T23:59:59.000Z

170

Interfacial energy effects and the evolution of pore size distributions during quartz precipitation in sandstone  

E-Print Network (OSTI)

Interfacial energy effects and the evolution of pore size distributions during quartz precipitation-scale to nanometer scale pores, interfacial energy (surface energy) effects can also become important. Interfacial energy typically increases the solubility of very small crystals growing in tiny pores, and when

Simon, Emmanuel

171

The Simultaneous Measurement of Rainfall Intensity, Drop-Size Distribution, and the Scattering of Visible Light  

Science Conference Proceedings (OSTI)

Field measurements were made of the attenuation of a low-power. He-Ne laser beam over a 272-m path. Concurrently, high-resolution (10 s) measurements of rainfall intensity were obtained at several points along the path and drop-size distributions ...

C. D. Stow; S. G. Bradley; K. Paulson; L. Couper

1991-10-01T23:59:59.000Z

172

Description of sprays using joint hyperbolic distribution in particle size and velocity  

SciTech Connect

The joint probability density functions of droplet size and velocity have been represented in sprays by the two-dimensional hyperbolic distribution. A distribution is provided, and a procedure to compute its eight parameters outlined. Analytical expressions for certain statistical quantities, such as mean diameters, momentum, kinetic energy etc., applicable under certain restrictions, are obtained. The computations for a water spray issuing from a Danfoss 60{degrees} solid cone oil-burner nozzle demonstrate not only that the hyperbolic distribution provides an excellent approximation for the joint size and velocity distributions for the measurements taken along the entire length of the spray axis, but also that such representation presents a clear insight into the physics of the motion and the related size formation. The computations reveal a developing region, with areas dominated by breakup or coalescence of droplets, followed by a developed state with little change in droplet size but continuously decreasing velocity. It is concluded that this novel approach is well suited to the description of sprays.

Bhatia, J.C.; Durst, F. (LSTM-Erlangen, Lehrstuhl fur Stromungsmechanik, Universitat Erlangen-Nurnberg, 8520 Erlangen (DE))

1990-09-01T23:59:59.000Z

173

Influence of the Subgrid Variability of the Raindrop Size Distribution on Radar Rainfall Estimators  

Science Conference Proceedings (OSTI)

This work aims at quantifying the variability of the parameters of the power laws used for rain-rate estimation from radar data, on the basis of raindrop size distribution measurements over a typical weather radar pixel. Power laws between the ...

Joël Jaffrain; Alexis Berne

2012-04-01T23:59:59.000Z

174

An Experimental Study of Small-Scale Variability of Raindrop Size Distribution  

Science Conference Proceedings (OSTI)

An experimental study of small-scale variability of raindrop size distributions (DSDs) has been carried out at Wallops Island, Virginia. Three Joss–Waldvogel disdrometers were operated at a distance of 0.65, 1.05, and 1.70 km in a nearly straight ...

Ali Tokay; Paul G. Bashor

2010-11-01T23:59:59.000Z

175

The Dependence of Cirrus Cloud-Property Retrievals on Size-Distribution  

NLE Websites -- All DOE Office Websites (Extended Search)

The Dependence of Cirrus Cloud-Property Retrievals on Size-Distribution The Dependence of Cirrus Cloud-Property Retrievals on Size-Distribution Shape d'Entremont, Robert Atmospheric and Environmental Research, Inc. Mitchell, David Desert Research Institute Category: Cloud Properties Our project has focused on using satellite- and ground-based passive thermal infrared radiance observations to retrieve cirrus cloud properties, most importantly ice water path (IWP), effective particle size (Deff), and visible extinction optical thickness (tau). During this past year we began comparing our cirrus retrieval results with aircraft observations at the ARM CART site, and we are participating in a summary intercomparison study with other retrieval algorithms as a member of the high-clouds working group. Our passive-infrared retrieval scheme, based on different wavelength

176

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

Science Conference Proceedings (OSTI)

Data collected in midlatitude cirrus clouds by instruments on jet aircraft typically show particle size distributions that have distinct distribution modes in both the 10–30-?m maximum dimension (D) size range and the 200–300-?m D size range or ...

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

2011-06-01T23:59:59.000Z

177

COLOR DEPENDENCE IN THE SIZE DISTRIBUTION OF MAIN BELT ASTEROIDS REVISITED  

SciTech Connect

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

August, Tyler M.; Wiegert, Paul A., E-mail: tx_august@laurentian.ca [Department of Physics and Astronomy, The University of Western Ontario, London, ON N6A 3K7 (Canada)

2013-06-15T23:59:59.000Z

178

Effects of Nanoparticle Geometry and Size Distribution on Diffusion Impedance of Battery Electrodes  

E-Print Network (OSTI)

The short diffusion lengths in insertion battery nanoparticles render the capacitive behavior of bounded diffusion, which is rarely observable with conventional larger particles, now accessible to impedance measurements. Coupled with improved geometrical characterization, this presents an opportunity to measure solid diffusion more accurately than the traditional approach of fitting Warburg circuit elements, by properly taking into account the particle geometry and size distribution. We revisit bounded diffusion impedance models and incorporate them into an overall impedance model for different electrode configurations. The theoretical models are then applied to experimental data of a silicon nanowire electrode to show the effects of including the actual nanowire geometry and radius distribution in interpreting the impedance data. From these results, we show that it is essential to account for the particle shape and size distribution to correctly interpret impedance data for battery electrodes. Conversely, it...

Song, J

2012-01-01T23:59:59.000Z

179

Characteristics of inhalable particulate matter concentration and size distribution from power plants in China  

Science Conference Proceedings (OSTI)

The collection efficiency of particulate emission control devices (PECDs), particulate matter (PM) emissions, and PM size distribution were determined experimentally at the inlet and outlet of PECDs at five coal-fired power plants. Different boilers, coals, and PECDs are used in these power plants. Measurement in situ was performed by an electrical low-pressure impactor with a sampling system, which consisted of an isokinetic sampler probe, precut cyclone, and two- stage dilution system with a sample line to the instruments. The size distribution was measured over a range from 0.03 to 10 {mu}m. Before and after all of the PECDs, the particle number size distributions display a bimodal distribution. The PM2.5 fraction emitted to atmosphere includes a significant amount of the mass from the coarse particle mode. The controlled and uncontrolled emission factors of total PM, inhalable PM (PM10), and fine PM (PM2.5) were obtained. Electrostatic precipitator (ESP) and baghouse total collection efficiencies are 96.38 99.89% and 99.94%, respectively. The minimum collection efficiency of the ESP and the baghouse both appear in the particle size range of 0.1 1 0 {mu}m. In this size range, ESP and baghouse collection efficiencies are 85.79 98.6% and 99.54%. Real- time measurement shows that the mass and number concentration of PM10 will be greatly affected by the operating conditions of the PECDs. The number of emitted particles increases with increasing boiler load level because of higher combustion temperature. During test run periods, the data reproducibility is satisfactory. 19 refs., 11 figs., 6 tabs.

Honghong Yi; Jiming Hao; Lei Duan; Xinghua Li; Xingming Guo [Tsinghua University, Beijing (China). Department of Environmental Science and Engineering

2006-09-15T23:59:59.000Z

180

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

E-Print Network (OSTI)

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.

A. M. Selvam

2011-11-14T23:59:59.000Z

Note: This page contains sample records for the topic "grain size distribution" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

The Role of Ice Particle Shapes and Size Distributions in the Single Scattering Properties of Cirrus Clouds  

Science Conference Proceedings (OSTI)

The roles of ice particle size distributions (SDs) and particle shapes in cirrus cloud solar radiative transfer are investigated by analyzing SDs obtained from optical array probe measurements (particle sizes larger than 20–40 ?m) during ...

Andreas Macke; Peter N. Francis; Greg M. McFarquhar; Stefan Kinne

1998-09-01T23:59:59.000Z

182

Field Observations of In-Cloud Nucleation and the Modification of Atmospheric Aerosol Size Distributions after Cloud Evaporation  

Science Conference Proceedings (OSTI)

The authors measured aerosol and droplet size distributions in the range from 0.1 to 50 ”m, concentrations and sizes of precipitation particles, concentrations of condensation nuclei, and state parameters in and in the vicinity of a towering ...

A. J. Alkezweeny

1995-12-01T23:59:59.000Z

183

Pore and throat size distributions measured from synchrotron X-ray tomographic images of Fontainebleau sandstones  

E-Print Network (OSTI)

The three-dimensional geometry and connectivity of pore space controls the hydraulic transport behavior of crustal rocks. We report on direct measurement of flow-relevant geometrical properties of the void space in a suite of 4 samples of Fontainebleau sandstone ranging from 7.5% to 22% porosity. The measurements are obtained from computer analysis of three dimensional, synchrotron X-ray computed microtomographic images. We present measured distributions of coordination number, channel length, throat size and pore volume, and of correlations between throat-size/pore-volume and nearest neighbor pore-volume/pore volume determined for these samples. We also present quantitative characterization of the distributions measured. The effects of finite sample volume are investigated. The accuracy of the numerical algorithms employed is investigated using a simulated image of hexagonal closed packed spheres.

W. Brent Lindquist; Arun Venkatarangan; John Dunsmuir; Teng-fong Wong

1999-01-01T23:59:59.000Z

184

Particle size distribution of airborne plutonium near a chemical separations facility  

Science Conference Proceedings (OSTI)

Particulate matter containing Pu-238 and Pu-239,240 emitted from a stack at the Savannah River Plant was collected and fractionated by size with cascade impactors. Two impactor measurements were made at a distance of 200 meters from the H-Area stack and a third was at a distance of 420 meters. Annual collections were made for three years. The Pu-238 and Pu 239,240 concentrations were determined for each of the size fractions. The fractions collected at 200 m from the 62 m stack showed a biphasic curve for both Pu-238 and Pu-239,240. The highest concentration for both Pu-238 and Pu-239,240 were found in the <0.49 ..mu..m fraction, with the secondary peak occurring in the fractions greater than 3.0 ..mu..m. At 420 meters from the stack, the size distribution curves for Pu-238 and Pu-239,240 were not biphasic; only one peak appeared and that was for the fraction less than 0.49 ..mu..m. The doses to different organs from plutonium inhalation were calculated for the particle size distributions obtained in this study. The maximum potential 50-year dose commitment to the bone, the critical organ, for one year continuous exposure was 13 mrem for Pu-238 and 0.44 mrem for Pu-239,240 at 200 meters from the H-Area stack.

Gay, D.D.; Watts, J.R.

1981-12-01T23:59:59.000Z

185

Models for Unsaturated Hydraulic Conductivity Based on Truncated Lognormal Pore-size Distributions  

E-Print Network (OSTI)

We develop a closed-form three-parameter model for unsaturated hydraulic conductivity associated with a three-parameter lognormal model of moisture retention, which is based on lognormal grainsize distribution. The derivation of the model is made possible by a slight modification to the theory of Mualem. We extend the three-parameter lognormal distribution to a four-parameter model that also truncates the pore size distribution at a minimum pore radius. We then develop the corresponding four-parameter model for moisture retention and the associated closed-form expression for unsaturated hydraulic conductivity. The four-parameter model is fitted to experimental data, similar to the models of Kosugi and van Genuchten. The proposed four-parameter model retains the physical basis of Kosugi's model, while improving fit to observed data especially when simultaneously fitting pressure-saturation and pressure-conductivity data.

Malama, Bwalya

2013-01-01T23:59:59.000Z

186

The effect of grain shape on strength variability of alumina ceramics  

SciTech Connect

Fine-grained and coarse-grained aluminas containing either equiaxed or elongated grain structures were fabricated from commercial-purity and high-purity alumina powders. Compared to the high-purity aluminas, the commercial-purity aluminas having a coarse grain size and elongated grain structures exhibited significantly more pronounced flaw tolerance and T-curve behavior. T-curve behavior determined from indentation strength tests suggested that only the coarse- grained, elongated-grain alumina had a T-curve sufficient to cause stable crack extension prior to failure, a requirement for any observable improvement in reliability. In the high-purity aluminas as well as the fine-grained commercial-purity aluminas, however, it is likely that little or no stable extension occurs prior failure, suggesting that strength in these materials is dependent on the critical flaw size. Strength tests on polished specimens showed the commercial-purity aluminas had a lower means strength than the high- purity aluminas and the coarse-grained aluminas exhibited a lower mean strength compared to the fine-grained aluminas. An analysis of the mean strength versus grain size revealed that the differences in critical flaw size alone could not account for the differences in mean strength. Instead, a combination of changes in flaw size as well as T-curve behavior were shown to be responsible for the differences in strength and flaw tolerance. T-curve behavior was also found to have a profound influence on the strength variability of alumina. For example, the Weibull modulus for the coarse-grained, commercial- purity alumina was almost twice that of the fine-grained, high-purity material. Tests with indented specimens conclusively demonstrated that improvements in reliability in these materials are not due solely to changes in the critical flaw size distribution but rather a combination of flaw size distribution and T-curve behavior.

Readey, M.J.

1995-10-01T23:59:59.000Z

187

Temporal Variations of Aerosol Optical Parameters Resulting from the Aging of a Model Aerosol Number Size Distribution  

Science Conference Proceedings (OSTI)

Aerosol number size distributions are subject to aging, i.e., to temporal variations. The aging of a Junge number size distribution due to a multitude of processes was modeled by Junge and Abel. The pertinent changes with time of aerosol optical ...

J. Freund

1984-04-01T23:59:59.000Z

188

Continuum representation of a continuous size distribution of particles engaged in rapid granular flow  

Science Conference Proceedings (OSTI)

Natural and industrial granular flows often consist of several particle sizes, approximately forming a continuous particle size distribution (PSD). Continuous PSDs are ubiquitous, though existing kinetic-theory-based, hydrodynamic models for rapid granular flows are limited to a discrete number of species. The objective of this work is twofold: (i) to determine the number of discrete species required to accurately approximate a continuous PSD and (ii) to validate these results via a comparison with molecular dynamics (MD) simulations of continuous PSDs. With regard to the former, several analytic (Gaussian and lognormal) and experimental (coal and lunar soil simulants) distributions are investigated. Transport coefficients (pressure, shear viscosity, etc.) of the granular mixture given by the polydisperse theory of GarzŽo et al. [“Enskog theory for polydisperse granular mixtures. I. Navier-Stokes order transport,” Phys. Rev. E 76, 031303 (2007);“Enskog theory for polydisperse granular mixtures. I. Navier-Stokes order transport,” 76, 031304 (2007)] are compared using an increasing number of species s to approximate the given PSD. These discrete approximations are determined by matching the first 2s moments of the approximation and the given continuous distribution. Relatively few species are required to approximate moderately wide distributions (Gaussian, lognormal), whereas even wider distributions (coal and lunar soil simulants) require a larger number of species. Regarding the second objective, a comparison between MD simulations and kinetictheory predictions for a simple shear flow of both Gaussian and lognormal PSDs reveal essentially no loss of accuracy stemming from the polydisperse theory itself (as compared to theories for monodisperse systems) or from the discrete approximations of continuous PSDs used in the polydisperse theory. C #2; 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4744987

Murray, J.A.; Benyahia, S.; Metzger, P.; Hrenya, C.M.

2012-01-01T23:59:59.000Z

189

SURFACE AREA, VOLUME, MASS, AND DENSITY DISTRIBUTIONS FOR SIZED BOMASS PARTICLES  

DOE Green Energy (OSTI)

This semi-annual technical progress report describes work performed at Morehouse College under DOE Grant No. DE-FC26-04NT42130 during the period July 01, 2004 to December 31, 2004 which covers the first 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, supply requests were processed and supplies including biomass test particles (hardwood sawdust AI14546) in the size range of 100-200 microns were obtained from a cofiring pilot plant research facility owned by Southern Company, Birmingham, AL. Morehouse has completed setting up of the gravimetric technique measurement system in the heat transfer laboratory, department of physics and dual degree engineering, Morehouse College. Simultaneously, REM, our subcontractor, has completed setting up of the electrodynamic balance (EDB) measurement system to characterize shape and mass for individual biomass particles. Testing of the gravimetric system, and calibration of the cameras and imaging systems using known sizes of polystyrene particles are in progress.

Ramanathan Sampath

2004-05-01T23:59:59.000Z

190

Drop Size Distributions Measured by a 2D Video Disdrometer: Comparison with Dual-Polarization Radar Data  

Science Conference Proceedings (OSTI)

An analysis of drop size distributions (DSDs) measured in four very different precipitation regimes is presented and is compared with polarimetric radar measurements. The DSDs are measured by a 2D video disdrometer, which is designed to measure ...

Terry J. Schuur; Alexander V. Ryzhkov; Dusan S. Zrni?; Michael Schönhuber

2001-06-01T23:59:59.000Z

191

Sea-Salt Size Distributions from Breaking Waves: Implications for Marine Aerosol Production and Optical Extinction Measurements during SEAS  

Science Conference Proceedings (OSTI)

The authors' participation in the Shoreline Environment Aerosol Study (SEAS) involved measurements focused on the coastal aerosol size distribution and related optical measurements, including aerosol light scattering, visibility, and remote ...

A. Clarke; V. Kapustin; S. Howell; K. Moore; B. Lienert; S. Masonis; T. Anderson; D. Covert

2003-10-01T23:59:59.000Z

192

Measurements of Raindrop Size Distributions over the Pacific Warm Pool and Implications for Z–R Relations  

Science Conference Proceedings (OSTI)

Raindrop images obtained on research flights of the NCAR Electra aircraft in the Tropical Oceans Global Atmosphere Coupled Ocean–Atmosphere Response Experiment (TOGA COARE) are analyzed. The drop size distributions, based on the images obtained ...

Sandra E. Yuter; Robert A. Houze Jr.

1997-07-01T23:59:59.000Z

193

Quantification of the Small-Scale Spatial Structure of the Raindrop Size Distribution from a Network of Disdrometers  

Science Conference Proceedings (OSTI)

The spatial structure of the raindrop size distribution (DSD) conveys crucial information for reliable quantitative estimation of rainfall using remote sensing techniques. To investigate this question, a network of 16 optical disdrometers has been ...

Joël Jaffrain; Alexis Berne

2012-05-01T23:59:59.000Z

194

Numerical Investigation of Collision-Induced Breakup of Raindrops. Part II: Parameterizations of Coalescence Efficiencies and Fragment Size Distributions  

Science Conference Proceedings (OSTI)

Results of numerically investigated binary collisions of 32 drop pairs presented in Part I of this study are used to parameterize coalescence efficiencies and size distributions of breakup fragments of large raindrops.

Winfried Straub; Klaus Dieter Beheng; Axel Seifert; Jan Schlottke; Bernhard Weigand

2010-03-01T23:59:59.000Z

195

Observations of Saharan Aerosols: Results of ECLATS Field Experiment. Part I: Optical Thicknesses and Aerosol Size Distributions  

Science Conference Proceedings (OSTI)

A series of ground-based and airborne observations of desert aerosols, the ECLATS experiment was carried out in December 1980 in the vicinity of Niamey (Niger). This paper deals with aerosol optical thicknesses and size distributions derived from ...

Y. Fouquart; B. Bonnel; M. Chaoui Roquai; R. Santer; A. Cerf

1987-01-01T23:59:59.000Z

196

The Modification of Joint Size–Charge Distribution in Rain. Part I: Computations which Exclude Partial Coalescence  

Science Conference Proceedings (OSTI)

The effect of individual charge-modifying processes is tested by following the development joint distributions of raindrop size and charge through a fall depth of 1 km beneath a weakly electrified warm cloud. Evaporation, ion capture and ...

S. G. Bradley; C. D. Stow

1984-10-01T23:59:59.000Z

197

Coincident In Situ and W-Band Radar Measurements of Drop Size Distribution in a Marine Stratus Cloud and Drizzle  

Science Conference Proceedings (OSTI)

Investigation of precipitation formation requires measurements of the drop size distribution in a cloud. These measurements have usually been made using ground-based radar systems or aircraft in situ probes. Difficulties encountered in practice ...

J. Galloway; A. Pazmany; J. Mead; R. E. McIntosh; D. Leon; J. French; S. Haimov; R. Kelly; G. Vali

1999-05-01T23:59:59.000Z

198

Improved Normalization of the Size Distribution of Atmospheric Particles Retrieved from Aureole Measurements Using the Diffraction Approximation  

Science Conference Proceedings (OSTI)

This paper describes an improvement in the diffraction approximation used to retrieve the size distribution of atmospheric particles from solar aureole radiance measurements. Normalization using total optical thickness based on measurement of the ...

J. G. DeVore

2011-08-01T23:59:59.000Z

199

Irreversible volume growth in polymer-bonded powder systems: effects of crystalline anisotropy, particle size distribution, and binder strength  

Science Conference Proceedings (OSTI)

Pressed-powdered crystallites of intrinsically anisotropic materials have been shown to undergo irreversible volume expansion when subjected to repeated cycles of heating and cooling. We develop a coarse-grained (micron-scale) interaction Hamiltonian for this system and perform molecular dynamics simulations, which quantitatively reproduce the experimentally observed irreversible growth. The functional form and values of the interaction parameters at the coarse-grained level are motivated by our knowledge at the atomic/molecular scale, and allows a simple way to incorporate the effect of polymeric binder. We demonstrate that irreversible growth happens only in the presence of intrinsic crystalline anisotropy of the powder material, is mediated by particles much smaller than the average crystallite size, and can be significantly reduced in the presence of high-strength polymeric binder with elevated glass transition temperatures.

Maiti, A; Gee, R H; Hoffman, D; Fried, L E

2007-08-22T23:59:59.000Z

200

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

DOE Green Energy (OSTI)

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.

Ramanathan Sampath

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "grain size distribution" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

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

DOE Green Energy (OSTI)

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.

Ramanathan Sampath

2006-06-30T23:59:59.000Z

202

Drop-size distribution for crosscurrent breakup of a liquid jet in a convective airstream  

E-Print Network (OSTI)

Experimental investigations have been completed in the study of a simulated fuel injector system implementing an airblast atomization process called a jet in a crossflow as the primary means of fuel atomization. To complete these studies an apparatus has been designed and constructed. A laser diffraction particle analyzer technique is used to spatially measure the spray Sauter-Mean Diameters. The Rosin-Rammler two parameter model is assumed for the droplet size distribution. Injection pressure for the injected liquid, distilled water, is held constant at 10.240 atm for the five different nozzle orifice diameters. A water rotameter is used to vary flowrates from 0.75 to 5.0 GPH and airflow Reynolds numbers are set at 50,000, 60,000, and 70,000 depending on the desired condition. SMD shows an increase in size for an increased distance from the top to the bottom of the test channel which is defined as the Y-Position from the orifice exit. The SMD growth rate decreases for increased water flowrates for a given airflow and orifice injector. For equal air-to-liquid ratios, overall SMD increases as the water flowrate and airflow Reynolds number combinations decrease. Overall SMD decreases for decreased air-to-liquid ratios. SMD decreases as the spray progresses downstream of the orifice exit in the direction of the airflow (X-Position) for a constant Y-Coordinate. A correlation of SMD-to-orifice diameter is determined to be as follows: [

Lyn, Gregory Michael

1994-01-01T23:59:59.000Z

203

The sizes and powers of some stochastic dominance tests: A Monte Carlo study for correlated and heteroskedastic distributions  

Science Conference Proceedings (OSTI)

Testing for stochastic dominance among distributions is an important issue in the study of asset management, income inequality, and market efficiency. This paper conducts Monte Carlo simulations to examine the sizes and powers of several commonly used ... Keywords: C12, Correlated distributions, D31, G11, Grid points, Heteroskedasticity, Stochastic dominance

Hooi-Hooi Lean; Wing-Keung Wong; Xibin Zhang

2008-10-01T23:59:59.000Z

204

The opacity of grains in protoplanetary atmospheres  

E-Print Network (OSTI)

We have computed the size distribution of silicate grains in the outer radiative region of the envelope of a protoplanet evolving according to the scenario of Pollack et al. (1996). Our computation includes grain growth due to Brownian motion and overtake of smaller grains by larger ones. We also include the input of new grains due to the breakup of planetesimals in the atmosphere. We follow the procedure of Podolak (2003), but have speeded it up significantly. This allows us to test the sensitivity of the code to various parameters. We have also made a more careful estimate of the resulting grain opacity. We find that the grain opacity is of the order of $10^{-2}\\ \\mathrm{cm^2 g^{-1}}$ throughout most of the outer radiative zone as Hubickyj et al. (2005) assumed for their low opacity case, but near the outer edge of the envelope, the opacity can increase to $\\sim{1} \\mathrm{cm^2 g^{-1}}$. We discuss the effect of this on the evolution of the models.

Naor Movshovitz; Morris Podolak

2007-09-29T23:59:59.000Z

205

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

E-Print Network (OSTI)

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.

A. M. Selvam

2009-08-17T23:59:59.000Z

206

DECODING THE MESSAGE FROM METEORITIC STARDUST SILICON CARBIDE GRAINS  

SciTech Connect

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.

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

207

The representation of rainfall drop-size distribution and kinetic energy Hydrology and Earth System Sciences, 8(5), 10011007 (2004) EGU  

E-Print Network (OSTI)

The representation of rainfall drop-size distribution and kinetic energy 1001 Hydrology and Earth-size distribution and kinetic energy Neil I. Fox Department of Soil, Environmental and Atmospheric Sciences373 Mc component of drop velocity. Keywords: drop-size distribution, drop kinetic energy, soil erosion Introduction

Paris-Sud XI, Université de

208

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

DOE Green Energy (OSTI)

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.

Ramanathan Sampath

2007-06-30T23:59:59.000Z

209

Doppler Cloud Radar Derived Drop Size Distributions in Liquid Water Stratus Clouds  

Science Conference Proceedings (OSTI)

A cloud particle size retrieval algorithm that uses radar reflectivity factor and Doppler velocity obtained by a 35-GHz Doppler radar and liquid water path estimated from microwave radiometer radiance measurements is developed to infer the size ...

Seiji Kato; Gerald G. Mace; Eugene E. Clothiaux; James C. Liljegren; Richard T. Austin

2001-10-01T23:59:59.000Z

210

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

DOE Green Energy (OSTI)

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.

Cheng, M-D.

2000-08-23T23:59:59.000Z

211

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

DOE Green Energy (OSTI)

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.

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

2000-08-01T23:59:59.000Z

212

Residual carbon from pulverized coal fired boilers 1: Size distribution and combustion reactivity  

Science Conference Proceedings (OSTI)

The amount of residual, or unburned, carbon in fly ash is an important concern in the design and operation of pulverized coal-fired boilers. Char oxidation is the slowest step in the coal combustion process, and the rate at which this heterogeneous reaction-proceeds has an important effect on the degree of carbon burnout. There is an extensive literature on char combustion kinetics based on data in the early and intermediate stages of carbon conversion. A critical fundamental question is whether the small fraction of the fuel carbon that passes unreacted through a boiler is representative of the char during the main portion of the combustion process. This article addresses that question through a detailed characterization of eight carbon-containing fly ash samples acquired from commercial-scale combustion systems. The fly ash characterization included measurement-of joint carbon/size distribution and determination.of the combustion reactivity of the residual carbon. To minimize mineral matter interactions in the reactivity tests, the technique of incipient fluidization was developed for separation of carbon-rich extracts from the inorganic portion of the fly ash. Reactivity measurements were made at 1400--1800 K to represent conditions in pulverized coal fired boilers. Measurements were also made at 700--1100 K to. minimize transport effects and isolate the influence of char chemistry and microstructure. In both temperature regimes, the residual carbon extracts. were significantly less reactive than chars extracted from a laboratory-scale laminar flow reactor in the early-to-intermediate stages of combustion. It is concluded that the boiler environment deactivates chars, making high carbon burnout more difficult to achieve than is predicted by existing char combustion kinetic models that were developed from data on the laboratory chars. Finally, the results are used to discuss potential char deactivation mechanisms, both thermal and oxidative, in coal-fired boilers.

Hurt, R.H. [Sandia National Labs., Livermore, CA (United States); Gibbins, J.R. [Imperial Coll. of Science, Technology and Medicine, London (United Kingdom). Dept. of Mechanical Engineering

1994-08-01T23:59:59.000Z

213

The Relation between the Area-Average Rain Rate and the Rain Cell Size Distribution Parameters  

Science Conference Proceedings (OSTI)

A review of the literature on the rain cell diameter distribution (RCDD) is first presented. It shows that RCDD, for a given rain-rate threshold ?, is accurately described by an exponential distribution with an exponential parameter ? weakly ...

Henri Sauvageot; Frédéric Mesnard; Ricardo S. Tenório

1999-01-01T23:59:59.000Z

214

Aerosol Particle Size Distribution (0.1–1.0 ?m) during the Chinooks of 1979 over Calgary, Canada  

Science Conference Proceedings (OSTI)

During the winter months of 1979, an Active Scattering Aerosol Spectrometer was operated in down-town Calgary to measure the effect of chinooks on the aerosol particle size distribution in the range 0.1–1.0 ?m. An Aerovironment Acoustic Sounder ...

C. V. Mathai; A. W. Harrison; T. Mathews

1980-05-01T23:59:59.000Z

215

Sieveless particle size distribution analysis of particulate materials through computer vision  

DOE Green Energy (OSTI)

This paper explores the inconsistency of length-based separation by mechanical sieving of particulate materials with standard sieves, which is the standard method of particle size distribution (PSD) analysis. We observed inconsistencies of length-based separation of particles using standard sieves with manual measurements, which showed deviations of 17 22 times. In addition, we have demonstrated the falling through effect of particles cannot be avoided irrespective of the wall thickness of the sieve. We proposed and utilized a computer vision with image processing as an alternative approach; wherein a user-coded Java ImageJ plugin was developed to evaluate PSD based on length of particles. A regular flatbed scanner acquired digital images of particulate material. The plugin determines particles lengths from Feret's diameter and width from pixel-march method, or minor axis, or the minimum dimension of bounding rectangle utilizing the digital images after assessing the particles area and shape (convex or nonconvex). The plugin also included the determination of several significant dimensions and PSD parameters. Test samples utilized were ground biomass obtained from the first thinning and mature stand of southern pine forest residues, oak hard wood, switchgrass, elephant grass, giant miscanthus, wheat straw, as well as Basmati rice. A sieveless PSD analysis method utilized the true separation of all particles into groups based on their distinct length (419 639 particles based on samples studied), with each group truly represented by their exact length. This approach ensured length-based separation without the inconsistencies observed with mechanical sieving. Image based sieve simulation (developed separately) indicated a significant effect (P < 0.05) on number of sieves used in PSD analysis, especially with non-uniform material such as ground biomass, and more than 50 equally spaced sieves were required to match the sieveless all distinct particles PSD analysis. Results substantiate that mechanical sieving, owing to handling limitations and inconsistent length-based separation of particles, is inadequate in determining the PSD of non-uniform particulate samples. The developed computer vision sieveless PSD analysis approach has the potential to replace the standard mechanical sieving. The plugin can be readily extended to model (e.g., Rosin Rammler) the PSD of materials, and mass-based analysis, while providing several advantages such as accuracy, speed, low cost, automated analysis, and reproducible results.

Igathinathane, C. [Mississippi State University (MSU); Pordesimo, L. O. [Mississippi State University (MSU); Columbus, Eugene P [ORNL; Batchelor, William D [ORNL; Sokhansanj, Shahabaddine [ORNL

2009-05-01T23:59:59.000Z

216

A Three Parameter Representation of the Shape and Size Distributions of Hailstones—A Case Study  

Science Conference Proceedings (OSTI)

The characteristics of shapes and sizes of a sample of 679 hailstones, collected on 22 June 1976 during a hailstorm at Grover, Colorado, were analyzed using a three-parameter formula developed by us previously. These parameters are a, the ...

Pao K. Wang; Thomas J. Greenwald; Jianlu Wang

1987-04-01T23:59:59.000Z

217

Impact of Precipitation on Aerosol Spectral Optical Depth and Retrieved Size Distributions: A Case Study  

Science Conference Proceedings (OSTI)

A case study is presented on the impact of two isolated, strong thundershowers during a prevailing dry, sunny season on the spectral optical depths and inferred columnar size characteristics of atmospheric aerosols at a tropical station. Results ...

Auromeet Saha; K. Krishna Moorthy

2004-06-01T23:59:59.000Z

218

Effects of Variable Droplet Growth Histories on Droplet Size Distributions. Part I: Theory  

Science Conference Proceedings (OSTI)

A theoretical framework is developed that permits estimation of the effects of fluctuating supersaturation on the development of cloud droplet size spectra. The studies focus on the role of turbulent fluctuations in vertical wind and in the ...

William A. Cooper

1989-05-01T23:59:59.000Z

219

A Study of Cirrus Ice Particle Size Distribution Using TC4 Observations  

Science Conference Proceedings (OSTI)

An analysis of two days of in situ observations of ice particle size spectra, in convectively generated cirrus, obtained during NASA’s Tropical Composition, Cloud, and Climate Coupling (TC4) mission is presented. The observed spectra are examined ...

Lin Tian; Gerald M. Heymsfield; Lihua Li; Andrew J. Heymsfield; Aaron Bansemer; Cynthia H. Twohy; Ramesh C. Srivastava

2010-01-01T23:59:59.000Z

220

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

DOE Patents (OSTI)

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

Ryon, Allen D. (Oak Ridge, TN); Haas, Paul A. (Knoxville, TN); Vavruska, John S. (Santa Fe, NM)

1984-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "grain size distribution" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Optimal Placement and Sizing of Distributed Generator Units using Genetic Optimization  

E-Print Network (OSTI)

and electricity in the distribution grid. A group of DG units can form a virtual power plant, being centrally of distributed generation units in a residential distri- bution grid. Power losses are minimized while grid topology with pro- duction and residential load data based on measurements. Different scenarios

222

KNIFE MILL COMMINUTION ENERGY ANALYSIS OF SWITCHGRASS, WHEAT STRAW, AND CORN STOVER AND CHARACTERIZATION OF PARTICLE SIZE DISTRIBUTIONS  

Science Conference Proceedings (OSTI)

Biomass preprocessing and pretreatment technologies such as size reduction and chemical preconditioning are aimed at reducing the cost of ethanol production from lignocellulosic biomass. Size reduction is an energy-intensive biomass preprocessing unit operation. In this study, switchgrass, wheat straw, and corn stover were chopped in an instrumented knife mill to evaluate size reduction energy and corresponding particle size distribution as determined with a standard forage sieve analyzer. Direct mechanical power inputs were determined using a dedicated data acquisition system for knife mill screen openings from 12.7 to 50.8 mm, rotor speeds between 250 and 500 rpm, and mass feed rates from 1 to 11 kg/min. A speed of 250 rpm gave optimum performance of the mill. Optimum feed rates for 25.4 mm screen and 250 rpm were 7.6, 5.8, and 4.5 kg/min for switchgrass, wheat straw, and corn stover, respectively. Total specific energy (MJ/Mg) was defined as the size reduction energy required to operate the knife mill plus that imparted to the biomass. Effective specific energy was defined as the energy imparted to the biomass. For these conditions, total specific energies were 27.3, 37.9, and 31.9 MJ/Mg and effective specific energies were 10.1, 15.5, and 3.2 MJ/Mg for switchgrass, wheat straw, and corn stover, respectively. These results demonstrated that biomass selection affects the size reduction energy, even for biomass with similar features. Second-order polynomial equations for the total specific energy requirement fitted well (R2 > 0.95) as a function of knife mill screen size, mass feed rate, and speed for biomass materials tested. The Rosin-Rammler equation fitted the cumulative undersize mass of switchgrass, wheat straw, and corn stover chop passed through ASABE sieves with high R2 (>0.983). Knife mill chopping of switchgrass, wheat straw, and corn stover resulted in particle size distributions classified as 'well-graded strongly fine-skewed mesokurtic', 'well-graded fine-skewed mesokurtic', and 'well-graded fine-skewed mesokurtic', respectively, for small knife mill screen sizes (12.7 to 25.4 mm) and distributions classified as 'well-graded fine-skewed mesokurtic', 'well-graded strongly fine-skewed mesokurtic', and 'well-graded fine-skewed mesokurtic', respectively, for the large screen size (50.8 mm). Total and effective specific energy values per unit size reduction of wheat straw were greater compared to those for switchgrass. Corn stover resulted in reduced total and effective specific energy per unit size reduction compared to wheat straw for the same operating conditions, but higher total specific energy per unit size reduction and lesser effective specific energy per unit size reduction compared to switchgrass. Data on minimized total specific energy with corresponding particle spectra will be useful for preparing feed material with a knife mill for subsequent grinding with finer size reduction devices.

Bitra, V.S.P. [University of Tennessee, Knoxville (UTK); Womac, A.R. [University of Tennessee, Knoxville (UTK); Sokhansanj, Shahabaddine [ORNL; Igathinathane, C. [North Dakota State University

2010-01-01T23:59:59.000Z

223

Refractive Index and Size Distribution of Aerosols as Estimated from Light Scattering Measurements  

Science Conference Proceedings (OSTI)

Angular distributions of the intensity of light scattered by airborne particles were measured for both parallel and perpendicularly polarized components. A precision polar nephelometer was constructed for use of this study. The data were analyzed ...

Masayuki Tanaka; Tamio Takamura; Teruyuki Nakajima

1983-07-01T23:59:59.000Z

224

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

E-Print Network (OSTI)

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 ...

McDonnell, Andrew M. P

2011-01-01T23:59:59.000Z

225

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

DOE Patents (OSTI)

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.

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

1982-01-19T23:59:59.000Z

226

Quantitative size-dependent structure and strain determination of CdSe nanoparticles using atomic pair distribution function analysis  

E-Print Network (OSTI)

The size-dependent structure of CdSe nanoparticles, with diameters ranging from 2 to 4 nm, has been studied using the atomic pair distribution function (PDF) method. The core structure of the measured CdSe nanoparticles can be described in terms of the wurtzite atomic structure with extensive stacking faults. The density of faults in the nanoparticles ~50% . The diameter of the core region was extracted directly from the PDF data and is in good agreement with the diameter obtained from standard characterization methods suggesting that there is little surface amorphous region. A compressive strain was measured in the Cd-Se bond length that increases with decreasing particle size being 0.5% with respect to bulk CdSe for the 2 nm diameter particles. This study demonstrates the size-dependent quantitative structural information that can be obtained even from very small nanoparticles using the PDF approach.

A. S. Masadeh; E. Bozin; C. L. Farrow; G. Paglia; P. Juhas; A. Karkamkar; M. G. Kanatzidis; S. J. L. Billinge

2007-04-10T23:59:59.000Z

227

FINE GRAIN NUCLEAR EMULSION  

DOE Patents (OSTI)

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

Oliver, A.J.

1962-04-24T23:59:59.000Z

228

An Inversion Problem on Inferring the Size Distribution of Precipitation Areas from Raingage Measurements  

Science Conference Proceedings (OSTI)

Given a long, continuous record of rain rate measured at a point on the ground, it is straightforward to select a threshold value of rate and note the duration of each event in which the threshold is exceeded. The distribution of durations for ...

M. K. Yau; R. R. Rogers

1984-02-01T23:59:59.000Z

229

Quantitative discrimination between geological materials with variable density contrast by high resolution X-ray computed tomography: An example using amygdule size-distribution in ancient lava flows  

Science Conference Proceedings (OSTI)

The bubble-size distribution in 2.7 billion year old lava flows can be used as a proof of concept illustrating a new set of techniques for measuring volumes of geological materials with variable density contrasts using high-resolution X-ray computed ... Keywords: Amygdules, Bootstrap resampling, Bubble-size distribution, Central limit theorem, Dynamic thresholding, X-ray tomography

Sanjoy M. Som, James W. Hagadorn, Weston A. Thelen, Alan R. Gillespie, David C. Catling, Roger Buick

2013-04-01T23:59:59.000Z

230

Grain Refining Aluminum Alloys  

Science Conference Proceedings (OSTI)

He has had responsibility within Alcoa for optimizing grain refining and alloying ... of grain refinement; Methods of grain refining; Attributes of chemical inoculants ...

231

Autonomous grain combine control system  

DOE Patents (OSTI)

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.

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

2013-06-25T23:59:59.000Z

232

Critical error rate of quantum-key-distribution protocols versus the size and dimensionality of the quantum alphabet  

SciTech Connect

A quantum-information analysis of how the size and dimensionality of the quantum alphabet affect the critical error rate of the quantum-key-distribution (QKD) protocols is given on an example of two QKD protocols--the six-state and {infinity}-state (i.e., a protocol with continuous alphabet) ones. In the case of a two-dimensional Hilbert space, it is shown that, under certain assumptions, increasing the number of letters in the quantum alphabet up to infinity slightly increases the critical error rate. Increasing additionally the dimensionality of the Hilbert space leads to a further increase in the critical error rate.

Sych, Denis V.; Grishanin, Boris A.; Zadkov, Victor N. [International Laser Center and Faculty of Physics, M.V. Lomonosov Moscow State University, 119899 Moscow (Russian Federation)

2004-11-01T23:59:59.000Z

233

Catalytic reforming catalyst with modified pore size distribution and a process using the same  

Science Conference Proceedings (OSTI)

This patent describes a catalytic reforming process for conversion of a naptha hydrocarbon at reforming conditions using a catalyst comprising at least one catalytic metal and alumina. The improvement comprises using a catalyst having the following properties in combination: a surface area above about 250 M/sup 2//gram of catalyst; a pore volume above about 0.44 cc/gram of catalyst in pores having diameters of from about 30 angstroms to about 38,000 angstroms; and a pore volume distribution wherein about 70 percent or less of the pore volume is in pores having diameters of from about 30 angstroms to about 400 angstroms. About 30 percent or more pore volume is in pores having diameters of from about 400 angstroms to about 38,000 angstroms.

Unmuth, E.E.; Fleming, B.A.

1987-05-12T23:59:59.000Z

234

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

DOE Green Energy (OSTI)

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.

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

2003-08-24T23:59:59.000Z

235

Electrical Mobility Spectrometer Using a Diethylene Glycol Condensation Particle Counter for Measurement of Aerosol Size Distributions Down to 1 nm  

Science Conference Proceedings (OSTI)

We report a new scanning mobility particle spectrometer (SMPS) for measuring number size distributions of particles down to {approx}1 nm mobility diameter. This SMPS includes an aerosol charger, a TSI 3085 nano differential mobility analyzer (nanoDMA), an ultrafine condensation particle counter (UCPC) using diethylene glycol (DEG) as the working fluid, and a conventional butanol CPC (the 'booster') to detect the small droplets leaving the DEG UCPC. The response of the DEG UCPC to negatively charged sodium chloride particles with mobility diameters ranging from 1-6 nm was measured. The sensitivity of the DEG UCPC to particle composition was also studied by comparing its response to positively charged 1.47 and 1.70 nm tetra-alkyl ammonium ions, sodium chloride, and silver particles. A high resolution differential mobility analyzer was used to generate the test particles. These results show that the response of this UCPC to sub-2 nm particles is sensitive to particle composition. The applicability of the new SMPS for atmospheric measurement was demonstrated during the Nucleation and Cloud Condensation Nuclei (NCCN) field campaign (Atlanta, Georgia, summer 2009). We operated the instrument at saturator and condenser temperatures that allowed the efficient detection of sodium chloride particles but not of air ions having the same mobility. We found that particles as small as 1 nm were detected during nucleation events but not at other times. Factors affecting size distribution measurements, including aerosol charging in the 1-10 nm size range, are discussed. For the charger used in this study, bipolar charging was found to be more effective for sub-2 nm particles than unipolar charging. No ion induced nucleation inside the charger was observed during the NCCN campaign.

Jiang, J.; Kuang, C.; Chen, M.; Attoui, M.; McMurry, P. H.

2011-02-01T23:59:59.000Z

236

Aerosol Size Distribution, Particle Concentration, and Optical Property Variability near Caribbean Trade Cumulus Clouds: Isolating Effects of Vertical Transport and Cloud Processing from Humidification Using Aircraft Measurements  

Science Conference Proceedings (OSTI)

This paper examines the effect of trade wind cumulus clouds on aerosol properties in the near-cloud environment using data from the Rain in Cumulus over the Ocean (RICO) campaign. Aerosol size distributions, particle concentrations, and optical ...

Robert M. Rauber; Guangyu Zhao; Larry Di Girolamo; Marilé Colón-Robles

2013-10-01T23:59:59.000Z

237

Diurnal Variations and Modulation by Easterly Waves of the Size Distribution of Convective Cloud Clusters over West Africa and the Atlantic Ocean  

Science Conference Proceedings (OSTI)

Using Metecosat satellite data in the atmospheric infrared window, the authors study short time-scale fluctuations of the size distribution of tropical convective cloud clusters for July to September 1989. A cluster at a given brightness-...

L. A. Toledo Machado; J-Ph Duvel; M. Desbois

1993-01-01T23:59:59.000Z

238

Determining Size Distributions and Composition of Particles Suspended in Water: A New SEM–EDS Protocol with Validation and Comparison to Other Methods  

Science Conference Proceedings (OSTI)

Knowledge of particle size distributions (PSDs) in seawater is important for understanding several facets of marine science, such as the behavior of light scattering in seawater, phytoplankton dynamics, and biogeochemical cycling. Here, a method ...

Heather Groundwater; Michael S. Twardowski; Heidi M. Dierssen; Antoine Sciandra; Scott A. Freeman

2012-03-01T23:59:59.000Z

239

Particles in the Lower Troposphere over the High Plains of the United States. Part I: Size Distributions, Elemental Compositions and Morphologies  

Science Conference Proceedings (OSTI)

Airborne measurements are presented of particle size distributions obtained during spring and summer at various locations in the High Plains of the United States. Two main particle modes are apparent: an accumulation mode between particle ...

Peter V. Hobbs; David A. Bowdle; Lawrence F. Radke

1985-12-01T23:59:59.000Z

240

An Analysis of Errors in Drop Size Distribution Retrievals and Rain Bulk Parameters with a UHF Wind Profiling Radar and a Two-Dimensional Video Disdrometer  

Science Conference Proceedings (OSTI)

Vertically pointed wind profiling radars can be used to obtain measurements of the underlying drop size distribution (DSD) for a rain event by means of the Doppler velocity spectrum. Precipitation parameters such as rainfall rate, radar ...

Laura Kanofsky; Phillip Chilson

2008-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "grain size distribution" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Estimation of N*0 for the Two-Scale Gamma Raindrop Size Distribution Model and Its Statistical Properties at Several Locations in Asia  

Science Conference Proceedings (OSTI)

An automatic estimation method is developed to detect stepwise changes in the amplitude parameter of the normalized raindrop size distribution (DSD) N*0. To estimate N*0, it is also assumed that the variation of three DSD parameters follows the ...

Toshiaki Kozu; Kazuhiro Masuzawa; Toyoshi Shimomai; Nobuhisa Kashiwagi

2010-04-01T23:59:59.000Z

242

Comparison of Raindrop Size Distribution Measurements by a Joss-Waldvogel Disdrometer, a PMS 2DG Spectrometer, and a POSS Doppler Radar  

Science Conference Proceedings (OSTI)

Three techniques for the measurement of raindrop size distributions are compared using data from a Joss-Waldvogel disdrometer (JWD), a Particle Measuring Systems 2DG spectrometer (PMS), and an Atmospheric Environment Service (AES) Precipitation ...

B. E. Sheppard; P. I. Joe

1994-08-01T23:59:59.000Z

243

Hydrated and Dried Aerosol-Size-Distribution Measurements from the Particle Measuring Systems FSSP-300 Probe and the Deiced PCASP-100X Probe  

Science Conference Proceedings (OSTI)

Comparisons of particle-size distributions measured by Particle Measuring Systems FSSP-300 and PCASP-100X probes through a range of relative humidities reveal that the deiced PCASP-100X probe dries hydrated submicron aerosols before measurement. ...

J. Walter Strapp; W. R. Leaitch; P. S. K. Liu

1992-10-01T23:59:59.000Z

244

Leakage diagnostics, sealant longevity, sizing and technologytransfer in residential thermal distribution systems: Part II.Residential thermal Distribution Systesm, Phase VI FinalReport  

SciTech Connect

This report builds on and extends our previous efforts as described in "Leakage Diagnostics, Sealant Longevity, Sizing and Technology Transfer in Residential Thermal Distribution Systems- CIEE Residential Thermal Distribution Systems Phase V Final Report, October 1997". New developments include defining combined duct and equipment efficiencies in a concept called "Tons At the Register" and on performance issues related to field use of the aerosol sealant technology. Some of the key results discussed in this report include: o Register, boot and air handler cabinet leakage can often represent a significant fraction of the total duct leakage in new construction. Because of the large range of pressures in duct systems an accurate characterization may require separating these components through improved leakage testing. o Conventional duct tape failed our accelerated longevity testing and is not, therefore, considered generally acceptable for use in sealing duct systems. Many other tapes and sealing approaches are available and practical and have passed our longevity tests. o Simulations of summer temperature pull-down time have shown that duct system improvements can be combined with equipment downsizing to save first cost, energy consumption, and peak power and still provide equivalent or superior comfort. o Air conditioner name plate capacity ratings alone are a poor indicator of how much cooling will actually be delivered to the conditioned space. Duct system efficiency can have as large an impact on performance as variations in SEER. o Mechanical duct cleaning techniques do not have an adverse impact on the ducts sealed with the Aerosol sealant. The material typically used in Aerosol sealing techniques does not appear to present a health or safety hazard. Results from this study were used by the California Energy Commission in the formation of the current Energy Efficiency Standards for Low-Rise Residential Buildings (CEC, (1998)), often referred to as Title 24. Current information on ducts and thermal distribution research can be found at http://ducts.lbl.gov

Buchanan, C.; Modera, M.; Sherman, M.; Siegel, J.; Walker, I.; Wang, D.

1998-12-01T23:59:59.000Z

245

First measurement of the small-scale spatial variability of the rain drop size distribution: Results from a crucial experiment and maximum entropy modeling  

E-Print Network (OSTI)

The main challenges of measuring precipitation are related to the spatio-temporal variability of the drop-size distribution, to the uncertainties that condition the modeling of that distribution, and to the instrumental errors present in the in situ estimations. This PhD dissertation proposes advances in all these questions. The relevance of the spatial variability of the drop-size distribution for remote sensing measurements and hydro-meteorology field studies is asserted by analyzing the measurement of a set of disdrometers deployed on a network of 5 squared kilometers. This study comprises the spatial variability of integral rainfall parameters, the ZR relationships, and the variations within the one moment scaling method. The modeling of the drop-size distribution is analyzed by applying the MaxEnt method and comparing it with the methods of moments and the maximum likelihood. The instrumental errors are analyzed with a compressive comparison of sampling and binning uncertainties that affect actual device...

Checa-Garcia, Ramiro

2013-01-01T23:59:59.000Z

246

Estimating Corn Grain Yields  

E-Print Network (OSTI)

This publication explains how to estimate the grain yield of a corn crop before harvest. An interactive grain yield calculator is included. 6 pages, 3 tables, 1 figure.

Blumenthal, Jurg M.; Thompson, Wayne

2009-06-12T23:59:59.000Z

247

Ultrafine Grained Materials I  

Science Conference Proceedings (OSTI)

Aug 6, 2013... grains for planar symmetrical and asymmetrical high and low angle ... whereas the twist component is responsible for the concurrent grain ...

248

Optimal Siting and Sizing of Solar Photovoltaic Distributed Generation to Minimize Loss, Present Value of Future Asset Upgrades and Peak Demand Costs on a Real Distribution Feeder.  

E-Print Network (OSTI)

??The increasing penetration of distributed generation (DG) in power distribution systems presents technical and economic benefits as well as integration challenges to utility engineers. Governments… (more)

Mukerji, Meghana

2011-01-01T23:59:59.000Z

249

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

SciTech Connect

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

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

2011-06-21T23:59:59.000Z

250

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

SciTech Connect

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

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

2011-06-01T23:59:59.000Z

251

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

SciTech Connect

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

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

2012-01-04T23:59:59.000Z

252

A Current Re-distribution Scheme for Improved Energy Harvesting in Concentrating Photovoltaic Systems Using Fine-grained dc-dc Conversion.  

E-Print Network (OSTI)

??This thesis presents a distributed power-management architecture for concentrating photovoltaic (CPV) systems. Specifically, the ?-conversion scheme with voltage equalization is analyzed and verified for the… (more)

Zaman, Mohammad Shawkat

2013-01-01T23:59:59.000Z

253

Direct mechanical energy measures of hammer mill comminution of switchgrass, wheat straw, and corn stover and analysis of their particle size distributions  

Science Conference Proceedings (OSTI)

Biomass particle size impacts handling, storage, conversion, and dust control systems. Size reduction mechanical energy was directly measured for switchgrass (Panicum virgatum L.), wheat straw (Triticum aestivum L.), and corn stover (Zea mays L.) in an instrumented hammer mill. Direct energy inputs were determined for hammer mill operating speeds from 2000 to 3600 rpm for 3.2 mm integral classifying screen and mass input rate of 2.5 kg/min with 90 - and 30 -hammers. Overall accuracy of specific energy measurement was calculated as 0.072 MJ/Mg. Particle size distributions created by hammer mill were determined for mill operating factors using ISO sieve sizes from 4.75 to 0.02 mm in conjunction with Ro-Tap sieve analyzer. A wide range of analytical descriptors were examined to mathematically represent the range of particle sizes in the distributions. Total specific energy (MJ/Mg) was defined as size reduction energy to operate the hammer mill plus that imparted to biomass. Effective specific energy was defined as energy imparted to biomass. Total specific energy for switchgrass, wheat straw, and corn stover grinding increased by 37, 30, and 45% from 114.4, 125.1, and 103.7 MJ/Mg, respectively, with an increase in hammer mill speed from 2000 to 3600 rpm for 90 -hammers. Corresponding total specific energy per unit size reduction was 14.9, 19.7, and 13.5 MJ/Mg mm, respectively. Effective specific energy of 90 -hammers decreased marginally for switchgrass and considerably for wheat straw and it increased for corn stover with an increase in speed from 2000 to 3600 rpm. However, effective specific energy increased with speed to a certain extent and then decreased for 30 -hammers. Rosin Rammler equation fitted the size distribution data with R2 > 0.995. Mass relative span was greater than 1, which indicated a wide distribution of particle sizes. Hammer milling of switchgrass, wheat straw, and corn stover with 3.2 mm screen resulted in well-graded fine-skewed mesokurtic particles. Uniformity coefficient was corn stover, which indicated a moderate assortment of particles. Size-related parameters, namely, geometric mean diameter, Rosin Rammler size parameter, median diameter, and effective size had strong correlation among themselves and good negative correlation with speed. Distribution-related parameters, namely, Rosin Rammler distribution parameter, mass relative span, inclusive graphic skewness, graphic kurtosis, uniformity index, uniformity coefficient, coefficient of gradation and distribution geometric standard deviation had strong correlation among themselves and a weak correlation with mill speed. Results of this extensive analysis of specific energy and particle sizes can be applied to selection of hammer mill operating factors to produce a particular size of switchgrass, wheat straw, and corn stover grind, and will serve as a guide for relations among the energy and various analytic descriptors of biomass particle distributions.

Bitra, V.S.P [University of Tennessee; Womac, A.R. [University of Tennessee; Chevanan, Nehru [University of Tennessee; Miu, P.I. [University of Tennessee; Smith, D.R. [University of Tennessee; Igathinathane, C. [Mississippi State University (MSU); Sokhansanj, Shahabaddine [ORNL

2009-07-01T23:59:59.000Z

254

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

SciTech Connect

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

Plionis, Alexander A [Los Alamos National Laboratory; Peterson, Dominic S [Los Alamos National Laboratory; Tandon, Lav [Los Alamos National Laboratory; Lamont, Stephen P [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

255

Unified formulation of single and multi-moment normalizations of the raindrop size distribution based on the gamma probability density function  

Science Conference Proceedings (OSTI)

This study offers a unified formulation of single and multi-moment normalizations of the raindrop size distribution (DSD), which have been proposed in the framework of scaling analyses in the literature. The key point is to consider a well-defined ...

Nan Yu; Guy Delrieu; Brice Boudevillain; Pieter Hazenberg; Remko Uijlenhoet

256

A Microcomputer Data-Acquisition System for Real-Time Processing of Raindrop Size Distribution Measured with the RD69 Distrometer  

Science Conference Proceedings (OSTI)

The disdrometer is an instrument used worldwide to measure the size distribution of raindrops at ground level. In this paper, a data-acquisition and real-time processing system designed for disdrometer measurements is presented. It is based on a ...

Bernard Campistron; Gilbert Despaux; Jean-Pierre Lacaux

1987-09-01T23:59:59.000Z

257

The Impact of Ice Crystal Shapes, Size Distributions, and Spatial Structures of Cirrus Clouds on Solar Radiative Fluxes  

Science Conference Proceedings (OSTI)

The solar radiative properties of cirrus clouds depend on ice particle shape, size, and orientation, as well as on the spatial cloud structure. Radiation schemes in atmospheric circulation models rely on estimates of cloud optical thickness only. ...

I. Schlimme; A. Macke; J. Reichardt

2005-07-01T23:59:59.000Z

258

Collision, Coalescence and Breakup of Raindrops. Part I: Experimentally Established Coalescence Efficiencies and Fragment Size Distributions in Breakup  

Science Conference Proceedings (OSTI)

The collision, coalescence and breakup of single raindrop pairs were studied at terminal velocities and laboratory pressure (100 kPa) in 761 collision experiments (out of 14 000 attempts). Six size combinations were used with drop pair diameters ...

T. B. Low; Roland List

1982-07-01T23:59:59.000Z

259

On the Aerosol Particle Size Distribution Spectrum in Alaskan Air Mass Systems: Arctic Haze and Non-Haze Episodes  

Science Conference Proceedings (OSTI)

Aerosols in central Alaskan winter air mass system were classified according to size by diffusive separation and light-scattering spectrometry. Particles entering central Alaska from the Pacific Marine environment had number concentrations ...

Glenn E. Shaw

1983-05-01T23:59:59.000Z

260

Program on Technology Innovation: Grain Growth in Lead Alloy Sheathing and Its Influence on the Life of Lead-Sheathed Power Cables  

Science Conference Proceedings (OSTI)

Urban electric utilities installed large quantities of paper-insulated, lead-covered (PILC) power cable for medium-voltage distribution until about 50 years ago. Lead grain growth and re-crystallization occur with the aging of the lead sheaths of these cables and are known to affect cable sheath life. This report describes re-crystallization and grain growth in lead and lead alloys, emphasizing cable-sheath alloys used in North America and how grain size influences tensile, fatigue, and creep properties ...

2007-05-31T23:59:59.000Z

Note: This page contains sample records for the topic "grain size distribution" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Investigation of the particle size distribution and particle density characteristics of Douglas fir hogged fuel fly ash collected under known combustion conditions. Technical Progress Report No. 2  

DOE Green Energy (OSTI)

The increased interest in wood as a fuel source, coupled with the increasing demand to control the emission generated by wood combustion, has created a need for information characterizing the emissions that occur for given combustion conditions. This investigation characterizes the carbon char and inorganic fly ash size and density distribution for each of thirty-eight Douglas fir bark samples collected under known conditions of combustion.

Lang, A.J.; Junge, D.C.

1978-12-01T23:59:59.000Z

262

A Bayesian Approach to Upscaling and Downscaling of Aircraft Measurements of Ice Particle Counts and Size Distributions  

Science Conference Proceedings (OSTI)

This study addresses the issue of how to upscale cloud-sized in situ measurements of ice to yield realistic simulations of ice clouds for a variety of modeling studies. Aircraft measurements of ice particle counts along a 79 km zigzag path were ...

A. R. Jameson; A. J. Heymsfield

263

A Bayesian Approach to Upscaling and Downscaling of Aircraft Measurements of Ice Particle Counts and Size Distributions  

Science Conference Proceedings (OSTI)

This study addresses the issue of how to upscale cloud-sized in situ measurements of ice to yield realistic simulations of ice clouds for a variety of modeling studies. Aircraft measurements of ice particle counts along a 79-km zigzag path were ...

A. R. Jameson; A. J. Heymsfield

2013-09-01T23:59:59.000Z

264

Ultrafine Grained Materials IV  

Science Conference Proceedings (OSTI)

Nov 1, 2006 ... Print Book and CD-ROM: Advances in Superplasticity and Superplastic Forming 2004. Print Book: Ultrafine Grained Materials III. Print Book: ...

265

Grain Boundaries I  

Science Conference Proceedings (OSTI)

Steps move at random intervals, leading to jerky motion of the interface and strongly non-parabolic dynamics during island grain shrinkage. Individual events

266

Ultrafine Grained Materials III  

Science Conference Proceedings (OSTI)

Aug 8, 2013 ... Tribological Characterizations of Ultrafine-Grained Alloys Processed by High Pressure Torsion: Nong Gao1; Chuan Ting Wang1; Wood ...

267

Grain Boundaries and Interfaces  

Science Conference Proceedings (OSTI)

Oct 8, 2012 ... Applying this algorithm to symmetric tilt grain boundaries offers direct links ... recognized role as an influential component of microstructure.

268

System Size, Energy and Centrality Dependence of Pseudorapidity Distributions of Charged Particles in Relativistic Heavy Ion Collisions  

E-Print Network (OSTI)

We present the first measurements of the pseudorapidity distribution of primary charged particles in Cu+Cu collisions as a function of collision centrality and energy, \\sqrtsnn = 22.4, 62.4 and 200 GeV, over a wide range of pseudorapidity, using the PHOBOS detector. Making a global comparison of Cu+Cu and Au+Au results, we find that the total number of produced charged particles and the rough shape (height and width) of the pseudorapidity distributions are determined by the number of nucleon participants. More detailed studies reveal that a more precise matching of the shape of the Cu+Cu and Au+Au pseudorapidity distributions over the full range of pseudorapidity occurs for the same Npart/2A value rather than the same Npart value. In other words, it is the collision geometry rather than just the number of nucleon participants that drives the detailed shape of the pseudorapidity distribution and its centrality dependence at RHIC energies.

B. Alver; B. B. Back; M. D. Baker; M. Ballintijn; D. S. Barton; R. R. Betts; R. Bindel; W. Busza; Z. Chai; V. Chetluru; E. García; T. Gburek; K. Gulbrandsen; J. Hamblen; I. Harnarine; C. Henderson; D. J. Hofman; R. S. Hollis; R. Ho?y?ski; B. Holzman; A. Iordanova; J. L. Kane; P. Kulinich; C. M. Kuo; W. Li; W. T. Lin; C. Loizides; S. Manly; A. C. Mignerey; R. Nouicer; A. Olszewski; R. Pak; C. Reed; E. Richardson; C. Roland; G. Roland; J. Sagerer; I. Sedykh; C. E. Smith; M. A. Stankiewicz; P. Steinberg; G. S. F. Stephans; A. Sukhanov; A. Szostak; M. B. Tonjes; A. Trzupek; G. J. van Nieuwenhuizen; S. S. Vaurynovich; R. Verdier; G. I. Veres; P. Walters; E. Wenger; D. Willhelm; F. L. H. Wolfs; B. Wosiek; K. Wo?niak; S. Wyngaardt; B. Wys?ouch

2007-09-25T23:59:59.000Z

269

The spatial distribution of mineral dust and its shortwave radiative forcing over North Africa: Modeling sensitivities to dust emissions and aerosol size treatments  

Science Conference Proceedings (OSTI)

A fully coupled meteorology-chemistry-aerosol model (WRF-Chem) with the implementation of two dust emission schemes (GOCART and DUSTRAN) into two aerosol models (MADE/SORGAM and MOSAIC) is applied over North Africa to investigate the modeling sensitivities to dust emissions and aerosol size treatments in simulating mineral dust and its shortwave (SW) radiative forcing. Model results of the spatial distribution of mineral dust and its radiative forcing are evaluated using measurements from the AMMA SOP0 campaign in January and February of 2006 over North Africa. Our study suggests that the size distribution of emitted dust can result in significant differences (up to 100%) in simulating mineral dust and its SW radiative forcing. With the same dust emission and dry deposition processes, two aerosol models, MADE/SORGAM and MOSAIC, can yield large difference in size distributions of dust particles due to their different aerosol size treatments using modal and sectional approaches respectively. However, the difference between the two aerosol models in simulating the mass concentrations and the SW radiative forcing of mineral dust is small (< 10%). The model simulations show that mineral dust increases AOD by a factor of 2, heats the lower atmosphere (1-3 km) with a maximum rate of 0.7?0.5 K day-1 below 1 km, and reduces the downwelling SW radiation by up to 25 W m-2 on 24-hour average at surface, highlighting the importance of including dust radiative impact in understanding the regional climate of North Africa. When compared to the available measurements, WRF-Chem simulations can generally capture the measured features of mineral dust and its radiative properties over North Africa, suggesting that the model can be used to perform more extensive simulations of regional climate over North Africa.

Zhao, Chun; Liu, Xiaohong; Leung, Lai-Yung R.; Johnson, Ben; McFarlane, Sally A.; Gustafson, William I.; Fast, Jerome D.; Easter, Richard C.

2010-09-20T23:59:59.000Z

270

Evidence for departure from a power-law flare size distribution for a small solar active region  

E-Print Network (OSTI)

Active region 11029 was a small, highly flare-productive solar active region observed at a time of extremely low solar activity. The region produced only small flares: the largest of the $>70$ Geostationary Observational Environmental Satellite (GOES) events for the region has a peak 1--$8{\\AA}$ flux of $2.2\\times 10^{-6} {\\rm W} {\\rm m}^{-2}$ (GOES C2.2). The background-subtracted GOES peak-flux distribution suggests departure from power-law behavior above $10^{-6} {\\rm W} {\\rm m}^{-2}$, and a Bayesian model comparison strongly favors a power-law plus rollover model for the distribution over a simple power-law model. The departure from the power law is attributed to this small active region having a finite amount of energy. The rate of flaring in the region varies with time, becoming very high for two days coinciding with the onset of an increase in complexity of the photospheric magnetic field. The observed waiting-time distribution for events is consistent with a piecewise-constant Poisson model. These res...

Wheatland, M S

2010-01-01T23:59:59.000Z

271

GRAIN REFINEMENT OF CAST URANIUM BY HEAT TREATMENT  

SciTech Connect

The thermal cycling, irradiation behavior, and fabrication characteristics of U are strongly dependent upon grain size; a smaller grain size yields the better properties. Grain refinement of cast U may be accomplished either by hot working in the high alpha temperature range or by heat treatment; refinement by the latter method was the object of this investigation. The variables studied were time, temperature, specimen size, multiple quenching, and alphaannealing after quenching. The results of the investigation have led to the following conclusions, within the scope of the experimental conditions. The grain size of cast U may be appreciably refined by beta-quenching. Time and temperature in the beta phase are not significant in determining the final alpha grain size. Multiple beta-quenches (two to four times) produce better grain size refinement than a single quench. Alpha-annealing after beta-quenching causes recrystallization, but does not greatly affect the grain size. Gamma-quenching is not recommended as a practical heat treatment. (auth)

Powell, G.W.; Klein, J.L.; Krashes, D.

1957-07-01T23:59:59.000Z

272

Grain Selection during Solidification in Spiral Grain Selector  

Science Conference Proceedings (OSTI)

macroscopic heat transfer and fluid flow and the calculated ..... 5 Predicted grain structure in the grain selector (a) and the cross sections at the height from the ...

273

Grain Refinement and Castings  

Science Conference Proceedings (OSTI)

Mar 13, 2012 ... Program Organizers: Trond Furu, Hydro ... Full scale DC casting trials of 6xxx alloy were performed. ... Small polyhedral silicon particles and globular aluminum grains were formed in the region near the probe (zone one).

274

Fine Grained Robotics  

E-Print Network (OSTI)

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 ...

Flynn, Anita M.

275

Multiscale modeling of the influence of Fe content in a Al-Si-Cu alloy on the size distribution of intermetallic phases and micropores  

Science Conference Proceedings (OSTI)

A multiscale model was developed to simulate the formation of Fe-rich intermetallics and pores in quaternary Al-Si-Cu-Fe alloys. At the microscale, the multicomponent diffusion equations were solved for multiphase (liquid-solid-gas) materials via a finite difference framework to predict microstructure formation. A fast and robust decentered plate algorithm was developed to simulate the strong anisotropy of the solid/liquid interfacial energy for the Fe-rich intermetallic phase. The growth of porosity was controlled by local pressure drop due to solidification and interactions with surrounding solid phases, in addition to hydrogen diffusion. The microscale model was implemented as a subroutine in a commercial finite element package, producing a coupled multiscale model. This allows the influence of varying casting conditions on the Fe-rich intermetallics, the pores, and their interactions to be predicted. Synchrotron x-ray tomography experiments were performed to validate the model by comparing the three-dimensional morphology and size distribution of Fe-rich intermetallics as a function of Fe content. Large platelike Fe-rich {beta} intermetallics were successfully simulated by the multiscale model and their influence on pore size distribution in shape castings was predicted as a function of casting conditions.

Wang Junsheng; Lee, Peter D. [Department of Materials, Imperial College London, South Kensington Campus, Prince Consort Road, London SW7 2AZ (United Kingdom); Li Mei; Allison, John [Materials Research and Advanced Engineering Department, Ford Research Laboratory, Dearborn, Michigan 48121-2053 (United States)

2010-03-15T23:59:59.000Z

276

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  

DOE Green Energy (OSTI)

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.

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

2009-12-01T23:59:59.000Z

277

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

SciTech Connect

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.

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

2012-06-28T23:59:59.000Z

278

Full Scale Gatorizing™ of Fine Grain Inconel 718  

Science Conference Proceedings (OSTI)

and fine grain size achieved in the extruded billet as well as the high cost ... with alloys such as 718, 901, or A286 succeeded in producing fine-grained billet by using ... by oil quench and aging at 718"C/8 hrs. and furnace cool to 62l0CI8 hrs.

279

Distribution:  

Office of Legacy Management (LM)

JAN26 19% JAN26 19% Distribution: OR00 Attn: h.H.M.Roth DFMusser ITMM MMMann INS JCRyan FIw(2) Hsixele SRGustavson, Document rocm Formal file i+a@mmm bav@ ~@esiaw*cp Suppl. file 'Br & Div rf's s/health (lic.only) UNITED STATES ATOMIC ENERGY COMMISSION SPECIAL NUCLEAB MATERIAL LICENSE pursuant to the Atomic Energy Act of 1954 and Title 10, Code of Federal Regulations, Chapter 1, P&t 70, "Special Nuclear Material Reg)llatiqm," a license is hereby issued a$hortztng the licensee to rekeive and possess the special nuclear material designated below; to use such special nuclear mat&ial for the purpose(s) and at the place(s) designated below; and to transfer such material to per&s authorized to receive it in accordance with the regula,tions in said Part.

280

The Impact of Size Distribution Assumptions in a Bulk One-Moment Microphysics Scheme on Simulated Surface Precipitation and Storm Dynamics during a Low-Topped Supercell Case in Belgium  

Science Conference Proceedings (OSTI)

In this research the impact of modifying the size distribution assumptions of the precipitating hydrometeors in a bulk one-moment microphysics scheme on simulated surface precipitation and storm dynamics has been explored for long-lived low-topped ...

Kwinten Van Weverberg; Nicole P. M. van Lipzig; Laurent Delobbe

2011-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "grain size distribution" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Comparison of Drop Size Distribution Parameter (D0) and Rain Rate from S-Band Dual-Polarized Ground Radar, TRMM Precipitation Radar (PR), and Combined PR–TMI: Two Events from Kwajalein Atoll  

Science Conference Proceedings (OSTI)

The estimation of the drop size distribution parameter [median volume diameter (D0)] and rain rate (R) from the Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) as well as from combined PR–TRMM Microwave Imager (TMI) algorithms ...

V. N. Bringi; Gwo-Jong Huang; S. Joseph Munchak; Christian D. Kummerow; David A. Marks; David B. Wolff

2012-11-01T23:59:59.000Z

282

Computer simulation of grain growth with mobile particles  

SciTech Connect

The authors have studied the influence of mobile particles on grain growth kinetics. Three time regimes are evident in the observed coarsening. Initially, most grains grow unhindered by particles, with a growth exponent close to 1/2. As with static impurities, once the mean grain size approaches the average inter-particle separation the microstructure becomes effectively pinned. With mobile impurities, however, the loaded grain boundaries eventually resume their motion. The depinning time is observed to be independent of particle concentration. The observed kinetic behavior, growth exponents, and depinning time are in agreement with a simple theoretical model with different mobilities for boundaries with and without attached particles.

Hassold, G.N. [GMI Engineering and Management Inst., Flint, MI (United States). Dept. of Science and Mathematics] [GMI Engineering and Management Inst., Flint, MI (United States). Dept. of Science and Mathematics; Srolovitz, D.J. [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Materials Science and Engineering] [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Materials Science and Engineering

1995-05-15T23:59:59.000Z

283

Microwave sintering of nanophase ceramics without concomitant grain growth  

DOE Patents (OSTI)

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

Eastman, J.A.; Sickafus, K.E.; Katz, J.D.

1991-04-15T23:59:59.000Z

284

Grain Refinement in TiC-Ni3Al Composites  

DOE Green Energy (OSTI)

The Cooperative Research and Development Agreement (CRADA) was to develop composites of TiC-Ni{sub 3}Al with refined grain microstructures for application in diesel engine fuel injection devices. Grain refinement is important for improved wear resistance and high strength for the applications of interest. Attrition milling effectively reduces the initial particle size and leads to a reduction of the final grain size. However, an increase in the oxygen content occurs concomitantly with the grinding operation and decreased densification of the compacts occurs during sintering.

Tiegs, T.N.

2001-01-30T23:59:59.000Z

285

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

SciTech Connect

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.

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

286

COAGULATION CALCULATIONS OF ICY PLANET FORMATION AT 15-150 AU: A CORRELATION BETWEEN THE MAXIMUM RADIUS AND THE SLOPE OF THE SIZE DISTRIBUTION FOR TRANS-NEPTUNIAN OBJECTS  

Science Conference Proceedings (OSTI)

We investigate whether coagulation models of planet formation can explain the observed size distributions of trans-Neptunian objects (TNOs). Analyzing published and new calculations, we demonstrate robust relations between the size of the largest object and the slope of the size distribution for sizes 0.1 km and larger. These relations yield clear, testable predictions for TNOs and other icy objects throughout the solar system. Applying our results to existing observations, we show that a broad range of initial disk masses, planetesimal sizes, and fragmentation parameters can explain the data. Adding dynamical constraints on the initial semimajor axis of 'hot' Kuiper Belt objects along with probable TNO formation times of 10-700 Myr restricts the viable models to those with a massive disk composed of relatively small (1-10 km) planetesimals.

Kenyon, Scott J. [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Bromley, Benjamin C., E-mail: skenyon@cfa.harvard.edu, E-mail: bromley@physics.utah.edu [Department of Physics, University of Utah, 201 JFB, Salt Lake City, UT 84112 (United States)

2012-03-15T23:59:59.000Z

287

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

Science Conference Proceedings (OSTI)

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.

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

288

Grain Retention and Formation of Planetesimals near the Snow Line in MRI-driven Turbulent Protoplanetary Disks  

E-Print Network (OSTI)

The first challenge in the formation of both terrestrial planets and the cores of gas giants is the retention of grains in protoplanetary disks. In most regions of these disks, gas attains sub-Keplerian speeds as a consequence of a negative pressure gradient. Hydrodynamic drag leads to orbital decay and depletion of the solid material in the disk, with characteristic timescales as short as only a few hundred years for meter-sized objects at 1 AU. In this paper, we suggest a particle retention mechanism which promotes the accumulation of grains and the formation of planetesimals near the water sublimation front or ``snow line.'' This model is based on the assumption that, in the regions most interesting for planet formation, the viscous evolution of the disk is due to turbulence driven by the magneto-rotational instability (MRI) in the surface layers of the disk. The depth to which MRI effectively generates turbulence is a strong function of the grain size and abundance. A sharp increase in the grain-to-gas density ratio across the snow line reduces the column depth of the active layer. As the disk evolves towards a quasi-steady-state, this change in the active layer creates a local maximum in radial distribution of the gas surface density and pressure, causing the gas to rotate at super-Keplerian speed and halting the inward migration of grains. This senario presents a robust process for grain retention which may aid in the formation of proto-gas-giant cores preferentially near the snow line.

Katherine A. Kretke; D. N. C. Lin

2007-06-08T23:59:59.000Z

289

Process for producing large grain cadmium telluride  

DOE Patents (OSTI)

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

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

1996-01-01T23:59:59.000Z

290

Process for producing large grain cadmium telluride  

DOE Patents (OSTI)

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.

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

1996-01-16T23:59:59.000Z

291

High Temperature Corrosion Fatigue and Grain Size Control in ...  

Science Conference Proceedings (OSTI)

diesel engines and so on, are inevitably subjected to the simultaneous effects of both the mechanical damages such as creep and/or fatigue and the corrosive.

292

139- Recrystallized Grain Size Prediction Based on Abnormal ...  

Science Conference Proceedings (OSTI)

125- Influence of Gas Flow Rate Ratio on the Structural Properties of a-SiC:H Prepared by ... 145- The Synergy of XRD and XRF in a Shale and Slate Analysis.

293

A Methodology for Controlling Grain Size in Friction Stir Processes  

Science Conference Proceedings (OSTI)

Adsorptive Removal of Phosphate Anions from Municipal Wastewater Using Raw and Wasted ... Al2O3 Inclusions by Ca-treatment · New Process for Producing High Grade Iron Concentrate by Roasting Siderite Ore with Microwave Energy.

294

Grain Size Effect on Densities of Dislocations with Edge ...  

Science Conference Proceedings (OSTI)

Corrosion of Mild Steel in Extreme Oil and Gas Environments · Corrosion ... Fluorescent Nanoparticle Tracers for Oil Exploration and Production · Formation of ...

295

Grain Size Control in Ring-Rolled Alloy 718  

Science Conference Proceedings (OSTI)

being placed in a furnace for reheat between passes. ... of the eight independent variables are directly controlled through the programming of the Colorado.

296

Thermal Stabilization of Nanocrystalline Grain Size by Kinetic and ...  

Science Conference Proceedings (OSTI)

This talk will review both kinetic and thermodynamic mechanisms and ... Basic Criteria for Formation of Growth Twins in High Stacking Fault Energy Metals.

297

Influence of Composition, Temperature and Grain Size on Fracture ...  

Science Conference Proceedings (OSTI)

Morphological Forms of Phosphogypsum Depending on Modification Approaches in Using as Mineral Filler for Polymer Composites · Nanostructured ...

298

An Automated Approach for Prior Austenite Grain Size Measurement ...  

Science Conference Proceedings (OSTI)

Since the approach relies on the crystallography of the phase transformation, it is independent of the ... 4-D Microstructural Characterization of Snow and Ice.

299

Grain Size Effects on the Energy Storage Properties of Barium ...  

Science Conference Proceedings (OSTI)

Symposium, Energy Storage III: Materials, Systems and Applications Symposium. Presentation Title ... Electrochemical Hydrogen Insertion in Titanium Carbide.

300

Predicting Grain Size Evolution of UDIMETź Alloy 718 during the ...  

Science Conference Proceedings (OSTI)

prior to final grinding and polishing in which approximately. lO-20mm of material in ... of selective induction heating on the disk circumference as well as welding ...

Note: This page contains sample records for the topic "grain size distribution" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Grain Size Dependence of Radiation Response in Silicon Carbide  

Science Conference Proceedings (OSTI)

CASL: The Consortium for Advanced Simulation of Light Water Reactors: A U.S. ... Strategies for Studying High Dose Irradiation Effects in Reactor Components.

302

Influences of Alloying Elements on Grain Sizes in Friction Stir ...  

Science Conference Proceedings (OSTI)

Aerosol Route Synthesis of Lithium Borate Spheres Using Lithium Nitrate and Boric Acid ... Investigation of Inclusion Evolution Mechanism during the Refining and ... Prediction of Hexagonal Lattice Parameters of Non-Stoichiometric Apatites by ... Raman Spectroscopic Study of Ammonia Borane: Phase Transitions at Low  ...

303

Effect of Microstructure and Grain Size on Fatigue Properties of ...  

Science Conference Proceedings (OSTI)

Abstract Scope, Passive metals exposed to fatigue and wear in corrosive ... In order to investigate multi-degradation, an in-house developed lab scale test rig ...

304

Characteristics of the Raindrop Size Distribution and Drop Shape Relation in Typhoon Systems in the Western Pacific from the 2D Video Disdrometer and NCU C-Band Polarimetric Radar  

Science Conference Proceedings (OSTI)

The drop size distribution (DSD) and drop shape relation (DSR) characteristics that were observed by a ground-based 2D video disdrometer and retrieved from a C-band polarimetric radar in the typhoon systems during landfall in the western Pacific, ...

Wei-Yu Chang; Tai-Chi Chen Wang; Pay-Liam Lin

2009-10-01T23:59:59.000Z

305

Estimating the Accuracy of Polarimetric Radar–Based Retrievals of Drop-Size Distribution Parameters and Rain Rate: An Application of Error Variance Separation Using Radar-Derived Spatial Correlations  

Science Conference Proceedings (OSTI)

The accuracy of retrieving the two drop size distribution (DSD) parameters, median volume diameter (D0), and normalized intercept parameter (NW), as well as rain rate (R), from polarimetric C-band radar data obtained during a cool-season, long-...

M. Thurai; V. N. Bringi; L. D. Carey; P. Gatlin; E. Schultz; W. A. Petersen

2012-06-01T23:59:59.000Z

306

A Methodology for Estimating the Parameters of a Gamma Raindrop Size Distribution Model from Polarimetric Radar Data: Application to a Squall-Line Event from the TRMM/Brazil Campaign  

Science Conference Proceedings (OSTI)

A methodology is proposed for estimating the parameters of a gamma raindrop size distribution model from radar measurements of Zh, Zdr, and Kdp at S band. Previously developed algorithms by Gorgucci et al. are extended to cover low rain-rate ...

V. N. Bringi; Gwo-Jong Huang; V. Chandrasekar; E. Gorgucci

2002-05-01T23:59:59.000Z

307

Effect of grain orientation and grain size on ferroelectric domain switching and evolution: Phase field simulations  

E-Print Network (OSTI)

the defects, causing a degradation of properties due to internal depoling fields.30,31 Again, these defects

Chen, Long-Qing

308

Large-grain polycrystalline silicon films with low intragranular defect density by low-temperature solid-phase crystallization  

E-Print Network (OSTI)

a grain size as large as 3.0 m deposited by disilane gas.3 TFTs made with channel lengths smaller than

Duffy, Thomas S.

309

Charging of insulating and conducting dust grains by flowing plasma and photoemission  

E-Print Network (OSTI)

The charging of conducting or alternatively insulating dust grains in a supersonic plasma flow with a directed photon flux is studied by the particle-in-cell method. The electron emission modifies the surface charge distribution on a grain and in the surrounding plasma. The charge and potential distributions on and around a dust grain are studied for different photon fluxes and different angles of the incident unidirectional photons with respect to the plasma flow velocity vector. Continuous and pulsed radiations are considered. We show that photoemission allows controlling the charge on conducting grains, and discuss the charging of stationary and spinning insulating grains. Interactions between positively charged grains can be stronger than for negatively charged grains. The simulations are carried out in two spatial dimensions, treating ions and electrons as individual particles.

Miloch, W J; Pecseli, H L; Trulsen, J

2009-01-01T23:59:59.000Z

310

Matrix grain characterisation by electron backscattering diffraction of powder metallurgy aluminum matrix composites reinforced with MoSi{sub 2} intermetallic particles  

Science Conference Proceedings (OSTI)

Research highlights: Six extruded PM AA6061/MoSi{sub 2}/15p were processed with and without ball milling {yields} EBSD was used to characterise matrix grain size and grain orientation. {yields} Ball milling decreases matrix grain size to submicrometric level. {yields} Ball milling produces a more equiaxed microstructure and larger misorientation. {yields} Increasing milling time produces matrix texture randomization.

Corrochano, J., E-mail: javier.corrochano.flores@gmail.com; Hidalgo, P.; Lieblich, M.; Ibanez, J.

2010-11-15T23:59:59.000Z

311

NCNR Magnetic Cluster Sizes in Recording Disks  

Science Conference Proceedings (OSTI)

... Presently, cluster sizes are believed to be about 10 nano meters to 15 nano meters, but accurate knowledge of the size distribution and even the ...

312

Grain refinement in bulk pure tantalum using equal channel angular extrusion  

E-Print Network (OSTI)

For this study, the effectiveness of equal channel angular extrusion (ECAE) to improve the material properties and processing characteristics of vacuum arc remelted (VAR) pure tantalum was determined. The primary objectives were: 1) determination of recrystallization temperatures for processed material 2) determination of the grain refinement potential of ECAE and 3) determination of the ability of ECAE to produce a homogeneous grain structure. The effects of initial grains size (as-cast: [] 5 mm, large: 500 [u]m - 2 mm, medium: 20 [u]m - 100[u]m) and morphology, annealing temperature (23°C - 1370°C) and level of strain (one, two, or four extrusions) and extrusion route (C and E) on the recrystallized grain size, percent recrystallization, microstructural uniformity, grain morphology and Vickers microhardness were investigated. All extrusions were performed at room temperature in a 90° die using a punch speed of 5 mm/sec. Microstructural uniformity and morphology were observed and characterized using an optical metallograph equipped with a polarizing filter. Grain size measurements were made using the linear intercept method on optical micrographs. Four consecutive passes without intermediate annealing show that pure VAR tantalum is very workable when subjected to ECAE processing. The initial grain size and processing route have little if any effect on the workability or recrystallization temperature after one extrusion pass. Microhardness values are similar to published literature values produced by conventional deformation methods at equivalent strains and tend to increase significantly during the first two extrusions. Routes 2C and 4C result in fine (<22 [u]m), uniform grains after annealing for the large and medium initial grain size materials but do not for the as-cast initial grain size. Route E results in fine-grained, homogeneous, equiaxed microstructures for all initial grain sizes with ~11 [u]m being the smallest produced. The microstructural homogeneity and uniformity, and the fine-grain size resulting from ECAE processing may be advantageous to those produced by the conventional methods such as rolling, swaging, forging and wire drawing, with the added advantage of being a bulk product. The Hall-Petch relationship is found to be valid for ECAE processed tantalum over a grain size range of 10 [u]m to 100[u]m.

Mathaudhu, Suveen Nigel

2001-01-01T23:59:59.000Z

313

Ice Cloud Particle Size Distributions and Pressure-Dependent Terminal Velocities from In Situ Observations at Temperatures from 0 to ?86 C  

Science Conference Proceedings (OSTI)

The primary goal of this study is to derive ice particle terminal velocities from micron to cm sizes and for atmospheric pressures covering the range 200–1000 hPa from data spanning a wide range of locations, temperatures, and altitudes and to ...

Andrew J. Heymsfield; Carl Schmitt; Aaron Bansemer

314

A multiprocessor architecture combining fine-grained and coarse-grained parallelism strategies  

Science Conference Proceedings (OSTI)

Keywords: coarse-grained, fine-grained, instruction-level parallelism, loop-level parallelism, multiprocessor, performance comparisons, pipelining, superscalar

David J. Lilja

1994-05-01T23:59:59.000Z

315

Effects of Multiple Reductions on Grain Refinement During Hot ...  

Science Conference Proceedings (OSTI)

of as-cast alloy 718, a research program was initiated at the ... process design criteria for grain size refinement during primary breakdown of alloy. 718 ingot via ..... however, can and does occur during the dwell time after each strain ..... statistically ..... (1981). D. K. Matlock and D. A. Burford,. "An Experimental. Correlation.

316

Formation of SiC Grains in Pulsation-Enhanced Dust-Driven Wind Around Carbon Rich Asymptotic Giant Branch Stars  

E-Print Network (OSTI)

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 in order to reveal not only the amount but also the size distribution. Two cases are considered for the nucleation process; one is the LTE case where the vibration temperature of SiC clusters $T_{\\rm v}$ is equal to the gas temperature as usual, and another is the non-LTE case in which $T_{\\rm v}$ is assumed to be the same as the temperature of small SiC grains. The results of hydrodynamical calculations for a model with stellar parameters of mass $M_{\\ast}$=1.0 $M_{\\odot}$, luminosity $L_{\\ast}$=10$^{4}$ $L_{\\odot}$, effective temperature $T_{\\rm eff}$=2600 K, C/O ratio=1.4, and pulsation period $P$=650 days show the followings: 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 $\\sim$ 10$^{-8}$ is too small to reproduce the ...

Yasuda, Yuki

2011-01-01T23:59:59.000Z

317

Thermal Flipping of Interstellar Grains  

E-Print Network (OSTI)

In interstellar dust grains, internal processes dissipate rotational kinetic energy. The dissipation is accompanied by thermal fluctuations, which transfer energy from the vibrational modes to rotation. Together, these processes are known as internal relaxation. For the past several years, internal relaxation has been thought to give rise to thermal flipping, with profound consequences for grain alignment theory. I show that thermal flipping is not possible in the limit that the inertia tensor does not vary with time.

Joseph C. Weingartner

2008-08-27T23:59:59.000Z

318

Grain boundary segregation of carbon in iron  

Science Conference Proceedings (OSTI)

Excess carbon was present near grain boundaries in specimens equilibrated at ... the amount of carbon near the grain boundaries was found to decrease as the

319

Investigating Grain Boundary Structure-Kinetic Property ...  

Science Conference Proceedings (OSTI)

Abstract Scope, Grain boundary energy landscapes contain all the information that is required to describe the kinetic behavior of grain boundaries (GBs).

320

Defects: Thermodynamics and Kinetics of Grain Boundaries ...  

Science Conference Proceedings (OSTI)

Feb 28, 2011 ... Topological Characteristics and Events in 3D Grain Growth: Burton ... due to gradual dissolution of particles can trigger abnormal grain growth.

Note: This page contains sample records for the topic "grain size distribution" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

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  

NLE Websites -- All DOE Office Websites (Extended Search)

0 0 December 2009 Net Metering Policy Development in Minnesota: Overview of Trends in Nationwide Policy Development and Implications of Increasing the Eligible System Size Cap Elizabeth Doris, Sarah Busche, and Stephen Hockett National Renewable Energy Laboratory 1617 Cole Boulevard, Golden, Colorado 80401-3393 303-275-3000 * www.nrel.gov NREL is a national laboratory of the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy Operated by the Alliance for Sustainable Energy, LLC Contract No. DE-AC36-08-GO28308 Technical Report NREL/TP-6A2-46670 December 2009 Net Metering Policy Development in Minnesota: Overview of Trends in Nationwide Policy Development and Implications of Increasing the Eligible System Size Cap

322

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

Science Conference Proceedings (OSTI)

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

Paul C. Millett

2012-02-01T23:59:59.000Z

323

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

Science Conference Proceedings (OSTI)

Here we explore light absorption by snowpack containing black carbon (BC) particles residing within ice grains. Basic considerations of particle volumes and BC/snow mass concentrations show that there are generally 0:05-109 BC particles for each ice grain. This suggests that internal BC is likely distributed as multiple inclusions within ice grains, and thus the dynamic effective medium approximation (DEMA) (Chylek and Srivastava, 1983) is a more appropriate optical representation for BC/ice composites than coated-sphere or standard mixing approximations. DEMA calculations show that the 460 nm absorption cross-section of BC/ice composites, normalized to the mass of BC, is typically enhanced by factors of 1.8-2.1 relative to interstitial BC. BC effective radius is the dominant cause of variation in this enhancement, compared with ice grain size and BC volume fraction. We apply two atmospheric aerosol models that simulate interstitial and within-hydrometeor BC lifecycles. Although only {approx}2% of the atmospheric BC burden is cloud-borne, 71-83% of the BC deposited to global snow and sea-ice surfaces occurs within hydrometeors. Key processes responsible for within-snow BC deposition are development of hydrophilic coatings on BC, activation of liquid droplets, and subsequent snow formation through riming or ice nucleation by other species and aggregation/accretion of ice particles. Applying deposition fields from these aerosol models in offline snow and sea-ice simulations, we calculate that 32-73% of BC in global surface snow resides within ice grains. This fraction is smaller than the within-hydrometeor deposition fraction because meltwater flux preferentially removes internal BC, while sublimation and freezing within snowpack expose internal BC. Incorporating the DEMA into a global climate model, we simulate increases in BC/snow radiative forcing of 43-86%, relative to scenarios that apply external optical properties to all BC. We show that snow metamorphism driven by diffusive vapor transfer likely proceeds too slowly to alter the mass of internal BC while it is radiatively active, but neglected processes like wind pumping and convection may play much larger roles. These results suggest that a large portion of BC in surface snowpack may reside within ice grains and increase BC/snow radiative forcing, although measurements to evaluate this are lacking. Finally, previous studies of BC/snow forcing that neglected this absorption enhancement are not necessarily biased low, because of application of absorption-enhancing sulfate coatings to hydrophilic BC, neglect of coincident absorption by dust in snow, and implicit treatment of cloud-borne BC resulting in longer-range transport.

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

2012-05-30T23:59:59.000Z

324

Size Effects  

Science Conference Proceedings (OSTI)

Mar 5, 2013 ... An Explanation of the Power-Exponent in the Size Effect on Strength in ... in terms of the Taylor-type resistance in the dislocation network in the specimen. ... hysteresis and loss in pseudoelasticity with decrease in sample size.

325

Modeling the Panchromatic Spectral Energy Distributions of Galaxies  

E-Print Network (OSTI)

The spectral energy distributions (SEDs) of galaxies are shaped by nearly every physical property of the system, including the star formation history, metal content, abundance pattern, dust mass, grain size distribution, star-dust geometry, and interstellar radiation field. The principal goal of stellar population synthesis (SPS) is to extract these variables from observed SEDs. In this review I provide an overview of the SPS technique and discuss what can be reliably measured from galaxy SEDs. Topics include stellar masses, star formation rates and histories, metallicities and abundance patterns, dust properties, and the stellar initial mass function.

Conroy, Charlie

2013-01-01T23:59:59.000Z

326

The Effect of High Temperature Deformation on Grain Growth in a ...  

Science Conference Proceedings (OSTI)

ram speed and temperature (1 lOo”C, 112o”C, or 1140°C) then followed by air quenching. ... The grain size was measured by quantitative image analysis of.

327

Fractal dust grains in plasma  

Science Conference Proceedings (OSTI)

Fractal dust grains of different shapes are observed in a radially confined magnetized radio frequency plasma. The fractal dimensions of the dust structures in two-dimensional (2D) horizontal dust layers are calculated, and their evolution in the dust growth process is investigated. It is found that as the dust grains grow the fractal dimension of the dust structure decreases. In addition, the fractal dimension of the center region is larger than that of the entire region in the 2D dust layer. In the initial growth stage, the small dust particulates at a high number density in a 2D layer tend to fill space as a normal surface with fractal dimension D = 2. The mechanism of the formation of fractal dust grains is discussed.

Huang, F. [College of Science, China Agricultural University, Beijing 100083 (China); Peng, R. D. [State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology, Beijing 100083 (China); Liu, Y. H. [Institute of Complexity Science, Qingdao University, Qingdao 266071 (China); Chen, Z. Y. [Department of Physics, Beijing University of Chemical Technology, Beijing 100029 (China); Ye, M. F.; Wang, L. [Institute of Physics, Chinese Academy of Science, Beijing 100190 (China)

2012-09-15T23:59:59.000Z

328

Quantum Fine-Grained Entropy  

E-Print Network (OSTI)

Regarding the strange properties of quantum entropy and entanglement, e.g., the negative quantum conditional entropy, we revisited the foundations of quantum entropy, namely, von Neumann entropy, and raised the new method of quantum fine-grained entropy. With the applications in entanglement theory, quantum information processing, and quantum thermodynamics, we demonstrated the capability of quantum fine-grained entropy to resolve some notable confusions and problems, including the measure of entanglement and quantumness, the additivity conjecture of entanglement of formation etc, and the definition of temperature for single quantum system.

Wang, Dong-Sheng

2012-01-01T23:59:59.000Z

329

Pore size estimation  

Science Conference Proceedings (OSTI)

A novel method for characterization of any porous structure is presented. The principle of the method is simple scanning a plane surface of a cellular material and consequent digital image analysis of the scan. Eleven samples of bread baked from dough ... Keywords: foams, image analysis, modelling the structure, plane cut visualization, pore size distribution, voronoi tessellation

Tomas Matousek; Petr Ponizil; Filip Kremen; Iva Buresova; Petra Dvorakova

2011-07-01T23:59:59.000Z

330

From Grains to Planetesimals: Les Houches Lecture  

E-Print Network (OSTI)

This pedagogical review covers an unsolved problem in the theory of protoplanetary disks: the growth of dust grains into planetesimals, solids at least a kilometer in size. I summarize timescale constraints imposed on planetesimal formation by circumstellar disk observations, analysis of meteorites, and aerodynamic radial migration. The infall of ~meter-sized solids in a hundred years is the most stringent constraint. I review proposed mechanisms for planetesimal formation. Collisional coagulation models are informed by laboratory studies of microgravity collisions. The gravitational collapse (or Safronov-Goldreich-Ward) hypothesis involves detailed study of the interaction between solid particles and turbulent gas. I cover the basics of aerodynamic drag in protoplanetary disks, including radial drift and vertical sedimentation. I describe various mechanisms for particle concentration in gas disks -- including turbulent pressure maxima, drag instabilities and long-lived anticylonic vortices. I derive a general result for the minimum size for a vortex to trap particles in a sub-Keplerian disk. Recent numerical simulations demonstrate that particle clumping in turbulent protoplanetary disks can trigger gravitational collapse. I discuss several outstanding issues in the field.

Andrew Youdin

2008-07-07T23:59:59.000Z

331

In vitro digestibility of starch in sorghum differing in endosperm hardness and flour particle size.  

E-Print Network (OSTI)

??In vitro digestibility of starch in sorghum grains differing in endosperm hardness and flour particle size was assayed by an Englyst resistant starch (RS) method.… (more)

Xu, Xiaoli

2008-01-01T23:59:59.000Z

332

Model Spectral Energy Distributions of Circumstellar Debris Disks I. Analytic Disk Density Distributions  

E-Print Network (OSTI)

We present results of a study aimed at deriving fundamental properties of circumstellar debris disks from observed infrared to submillimeter spectral energy distributions. This investigation is motivated by increasing telescope/detector sensitivity, in particular the expected availability of the Space Infrared Telescope Facility (SIRTF) followed by the Stratospheric Observatory for Infrared Astronomy (SOFIA), which will enable detailed studies with large source samples of late stage circumstellar disk and planetary system evolution. We base our study on an analytic model of the disk density distribution and geometry, taking into account existing constraints from observations and results of theoretical investigations of debris disks. We also outline the effects of the most profound characteristics of circumstellar dust including the grain size distribution and dust chemical composition. In particular we find that an increasing iron content in silicates mainly causes an increase of the dust absorption effiency and thus increases the dust reemission continuum. Furthermore, the influence of the sp 2 /sp 3 hybridization

Sebastian Wolf; Lynne A. Hillenbr

2003-01-01T23:59:59.000Z

333

Spectral Energy Distributions of Circumstellar Debris Disks I. Analytic Disk Density Distributions  

E-Print Network (OSTI)

We present results of a study aimed at deriving fundamental properties of circumstellar debris disks from observed infrared to submillimeter spectral energy distributions. This investigation is motivated by increasing telescope/detector sensitivity, in particular the expected availability of the Space Infrared Telescope Facility (SIRTF) followed by the Stratospheric Observatory for Infrared Astronomy (SOFIA), which will enable detailed studies with large source samples of late stage circumstellar disk and planetary system evolution. We base our study on an analytic model of the disk density distribution and geometry, taking into account existing constraints from observations and results of theoretical investigations of debris disks. We also outline the effects of the most profound characteristics of circumstellar dust including the grain size distribution and dust chemical composition.

Sebastian Wolf; Lynne Hillenbrand

2003-06-23T23:59:59.000Z

334

Optical method for the determination of grain orientation in films  

DOE Patents (OSTI)

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

Maris, Humphrey J. (Barrington, RI)

2001-01-01T23:59:59.000Z

335

Ultrafine Grained Materials II - Programmaster.org  

Science Conference Proceedings (OSTI)

Aug 8, 2013... encounter spectroscopic beam convolutions from multiple nanocrystalline grains within a specimen that makes complete information retrieval ...

336

2012 Market Report on Wind Technologies in Distributed Applications  

Wind Powering America (EERE)

1 1 Wind Program 2012 Market Report on Wind Technologies in Distributed Applications Alice Orrell, Pacific Northwest National Laboratory Heather Rhoads-Weaver, eFormative Options, LLC PNNL-SA-97689 2 What is "Distributed Wind"? Distributed wind is used on or near where it is generated and is... Not just small scale; could be any size turbine or array Employed by households, schools, farms, industrial facilities, municipalities Found in all 50 states and Puerto Rico and the U.S. Virgin Islands A large portion of turbines installed in U.S. on a per unit basis And has been used for more than 2,000 years to pump water and grind grain Photo Credit: Tom Rivers/The (Batavia, N.Y.) Daily News Photo Credit: Gamesa 3 Benefits of Distributed Wind

337

Light Scattering Characteristics and Size Distribution of ...  

Science Conference Proceedings (OSTI)

... Ian Thomas at CESARE. REFERENCES ... [19] Mulholland, GW, Hartman, AW, Hembree, GG, Marx, E., and Lettieri, T. R., "Development of a one ...

2003-12-16T23:59:59.000Z

338

110 Grain Boundary Character Distributions in Severe Plastic ...  

Science Conference Proceedings (OSTI)

053 Polymer-Derived Mesoporous SiOC/ZnO Nanocomposite for Water Decontamination ... 064 Synthesis and Study of the Chemical Interaction of Strontium .... 163 The Mechanism of Metallic Iron Aggregation and Effect of Addition Agent on ...

339

The Five Parameter Grain Boundary Character Distribution of a ...  

Science Conference Proceedings (OSTI)

P1-04: 3D Microstructural Characterization of Uranium Oxide as a Surrogate Nuclear ... P1-15: Gating System Optimisation Design Study of a Cast Automobile ... P2-27: Characterization of Carbonate Rocks through X-ray Microtomography.

340

E3: Grain Boundary Character Distributions in Isostructural Materials  

Science Conference Proceedings (OSTI)

C19: Dissolution Behavior of Cu Under Bump Metallization in Ball Grid Array Structure .... H2: Triboluminescent Smart Sensors for Structural Health Monitoring

Note: This page contains sample records for the topic "grain size distribution" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

E11: Evolution of the Grain Boundary Character Distribution During ...  

Science Conference Proceedings (OSTI)

A18: Effect of Local Alendronate Delivery on In Vivo Osteogenesis From PCL ... A7: On-the-fly System Design for High Precision/Ultra Fast/Wide Area Fabrication .... C19: Dissolution Behavior of Cu Under Bump Metallization in Ball Grid Array ... High Volume and Fast Turnaround Automated Inline TEM Sample Preparation.

342

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

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.

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

2012-09-17T23:59:59.000Z

343

Ultrafine-grained titanium for medical implants  

DOE Patents (OSTI)

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.

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

344

Cooling Rate Dependence of Boron Distribution in Low Carbon Steel  

Science Conference Proceedings (OSTI)

Presentation Title, Cooling Rate Dependence of Boron Distribution in Low ... the transformation of austenite to ferrite by reducing the grain boundary energy.

345

Grain refinement of cast niobium via equal channel angular extrusion/annealing  

E-Print Network (OSTI)

This research investigated the effectiveness of equal channel angular extrusion (ECAE) and annealing to improve the grain morphology and mechanical properties of electron-beam remelted pure niobium. Extrusions were performed at room temperature with a 90o die. Routes 1A, 2C, 4E and 8E were investigated with duplicate billets undergoing routes 1A, 2C and 4E to determine reproducibility. Niobium proved to be very workable during the ECAE process. Hardness increased most dramatically after the first pass and leveled off thereafter. Recrystallization temperatures for the Reference Metals material ranged from a low of 800o C for routes 2C, 4E and 8E to a high of 1000o C for route 1A. For the Wah Chang material, the recrystallization temperatures ranged from a low of 800o C for the 4E ECAE processed material to a high of 950o C for the asreceived material. The initial grain size and orientation have been hypothesized to be influential on recrystallized grain morphology for ECAE/annealing processed niobium. Smaller initial grains produce a smaller and more homogeneous recrystallized grain microstructure. The average grain diameters for the recrystallized 4E ECAE processed Wah Chang material are 13 �± 6.3 mm for the 1000o C annealed state (no banding) and are 21 �± 9.5 mm for the 1100o C annealed state (no banding). Reference Metals material that underwent route 4E and annealed at 1000o C resulted in an average grain diameter of 28 mm for billet 2 (banding) and an average grain diameter of 32 mm for billet 19 (slight banding). Reference Metals material that underwent route 8E (no banding) annealed at 1000o C resulted in an average grain diameter of 36 mm. Reference Metals material that underwent route 4E samples annealed at 1100o C resulted in an average grain diameter of 26 mm for billet 2 (banding) and an average grain diameter of 43 mm for billet 19 (slight banding). Route 8E (significant banding) annealed at 1100o C resulted in an average grain diameter of 29 mm. Strain failure decreases from the as-cast material to the worked/recrystallized material while the 0.2% yield stress and ultimate tensile strength increase from the as-cast material to the worked/recrystallized material. Long sub-grains are created in the as-worked material after one and two passes and become more broken up after four passes. Sub-grain boundary angles increase with increasing strain. To produce a fine and homogeneous microstructure from large grained niobium, intermediate annealing should be employed.

Bryant, Don O.

2005-12-01T23:59:59.000Z

346

MROrchestrator: A Fine-Grained Resource Orchestration Framework for MapReduce Clusters  

Science Conference Proceedings (OSTI)

Efficient resource management in data centers and clouds running large distributed data processing frameworks like MapReduce is crucial for enhancing the performance of hosted applications and boosting resource utilization. However, existing resource scheduling schemes in Hadoop MapReduce allocate resources at the granularity of fixed-size, static portions of nodes, called slots. In this work, we show that MapReduce jobs have widely varying demands for multiple resources, making the static and fixed-size slot-level resource allocation a poor choice both from the performance and resource utilization standpoints. Furthermore, lack of co-ordination in the management of mul- tiple resources across nodes prevents dynamic slot reconfigura- tion, and leads to resource contention. Motivated by this, we propose MROrchestrator, a MapReduce resource Orchestrator framework, which can dynamically identify resource bottlenecks, and resolve them through fine-grained, co-ordinated, and on- demand resource allocations. We have implemented MROrches- trator on two 24-node native and virtualized Hadoop clusters. Experimental results with a suite of representative MapReduce benchmarks demonstrate up to 38% reduction in job completion times, and up to 25% increase in resource utilization. We further show how popular resource managers like NGM and Mesos when augmented with MROrchestrator can hike up their performance.

Sharma, Bikash [Pennsylvania State University, University Park, PA; Prabhakar, Ramya [Pennsylvania State University, University Park, PA; Kandemir, Mahmut [Pennsylvania State University; Das, Chita [Pennsylvania State University, University Park, PA; Lim, Seung-Hwan [ORNL

2012-01-01T23:59:59.000Z

347

Grain Boundary and Intragranular Deformations during High ...  

Science Conference Proceedings (OSTI)

boundary sliding (GBS) was quantified by measuring microgrid offsets at grain .... microgrids are respectively 5 m and 0.5 m so as to obtain several grid line ...

348

Deformation and Transitions at Grain Boundaries  

Science Conference Proceedings (OSTI)

Formation of cell-wall structure during deformation • Intragranular boundaries: GNBs, IDBs, cell-block boundaries, etc. ... Hot Spots and Grain Boundaries.

349

Mobility of Partially Faceted Shrinking Grains  

Science Conference Proceedings (OSTI)

Presentation Title, Mobility of Partially Faceted Shrinking Grains ... Computation of Thermal Fields with Non-Stationary Model at Electron Beam Melting of Metals.

350

Mechanical Properties and Radiation Tolerance of Ultrafine Grained and Nanocrystalline Metals  

E-Print Network (OSTI)

Austenitic stainless steels are commonly used in nuclear reactors and have been considered as potential structural materials in fusion reactors due to their excellent corrosion resistance, good creep and fatigue resistance at elevated temperatures, but their relatively low yield strength and poor radiation tolerance hinder their applications in high dose radiation environments. High angle grain boundaries have long been postulated as sinks for radiation-induced defects, such as bubbles, voids, and dislocation 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 properties of the alloy were studied at elevated temperature by tensile tests and in situ neutron scattering measurements. Enhanced dynamic recovery process at elevated temperature due to dislocation climb lowers the strain hardening rate and ductility of ultrafine grained Fe-Cr-Ni alloy. Thermal stability of the ultrafine grained Fe-Cr-Ni alloy was examined by ex situ annealing and in situ heating within a transmission electron microscope. Abnormal grain growth at 827 K (600°C) is attributed to deformation-induced martensite, located at the triple junctions of grains. Helium ion irradiation studies on Fe-Cr-Ni alloy show that the density of He bubbles, dislocation loops, as well as irradiation hardening are reduced by grain refinement. In addition, we provide direct evidence, via in situ Kr ion irradiation within a transmission electron microscope, that high angle grain boundaries in nanocrystalline Ni can effectively absorb irradiation-induced dislocation loops and segments. The density and size of dislocation loops in irradiated nanocrystalline Ni were merely half of those in irradiated coarse grained Ni. The results imply that irradiation tolerance in bulk metals can be effectively enhanced by microstructure refinement.

Sun, Cheng

2013-05-01T23:59:59.000Z

351

Evaluating the transferability of coarse-grained, density-dependent implicit solvent models to mixtures and chains  

E-Print Network (OSTI)

Previously, we described a coarse-graining method for creating local density-dependent implicit solvent (DDIS) potentials that reproduce the radial distribution function (RDF) and solute excess chemical potential across a ...

Allen, Erik C.

352

Phase stability and grain growth in an Ag/Bi-2223 composite conductor prepared using fine-grained Bi-2223 as a precursor.  

SciTech Connect

We have investigated the stability and microstructural transformability of the Bi-2223 phase in a silver-sheathed monofilament composite tape fabricated using fine-grained Bi{sub 1.7}Pb{sub 0.3}Sr{sub 1.9}Ca{sub 2.0}-Cu{sub 3.0}O{sub y} (Bi-2223) as the precursor powder. The fully formed Bi-2223 precursor was prepared using established procedures. The purpose of this study was to explore the prospects for growing textured, large-grain-size Bi-2223 from the fine-grained precursor by process parameter perturbations. These perturbations included thermal ramp up variations, programmed heat treatment temperature and oxygen pressure fluctuations, and parameter manipulations during cool-down. Our results show that the types of heat treatments used in conventional oxide-powder-in-tube (OPIT) processing do not facilitate Bi-2223 grain growth when the precursor powder is preconcerted Bi-2223. We also observed that the Bi-2223 partially. decomposed during conventional thermal ramp-up in 0.075 atm O{sub 2}, but that this decomposition can be inhibited by ramping up in a reduced oxygen pressure. A pathway was found for back-reacting the fine-grained Bi-2223 (to Bi-2212, Bi-2201 and nonsuperconducting secondary phases), then reforming large-grained Bi-2223 in a colony microstructure having some distinct differences from that produced during conventional OPIT processing.

Merchant, N. N.

1998-09-17T23:59:59.000Z

353

Size-dependent structure of silver nanoparticles under high pressure  

SciTech Connect

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.

Koski, Kristie Jo

2008-12-31T23:59:59.000Z

354

Atomistic Simulation of Slow Grain Boundary Motion  

E-Print Network (OSTI)

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 ...

Deng, Chuang

355

Heartland Grain Fuels LP | Open Energy Information  

Open Energy Info (EERE)

Grain Fuels LP Grain Fuels LP Jump to: navigation, search Name Heartland Grain Fuels LP Place Aberdeen, South Dakota Zip 57401 Sector Bioenergy Product Heartland Grain Fuels is a cooperatively-owned producer of corn-derived ethanol that was acquired by Advanced Bioenergy in November 2006. Coordinates 46.975867°, -123.81598° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":46.975867,"lon":-123.81598,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

356

Ultrafine Grained Materials III TABLE OF CONTENTS  

Science Conference Proceedings (OSTI)

R.Ye. Lapovok and P.W.J. Mckenzie. The Effect on Grain Refinement of Developing a Strong Texture in an UFGAl-0.13 Mg Alloy Severly Deformed by ECAE [pp.

357

Distillers Grains: Production, Properties, and Utilization  

Science Conference Proceedings (OSTI)

During the past several years, distillers dried grains with solubles (known as DDGS) has become a major feed ingredient in North America, and its use is increasing globally. This book provides a comprehensive summary of the research conducted to determine

358

Quartz size/shape relationships: variable size/shape relationships of detrital quartz reflect differences in source/transport parameters  

SciTech Connect

A common misconception is that as size decreases, quartz grains become progressively more angular. All possible size/shape relationships can and do occur including: 1) no relationship, 2) fine sizes, more rounded, 3) finer sized more angular, and 4) size/shape discontinuities where shape is constant over a wide range and then changes and stays constant over the remaining range. Detritus from large, long established flood plains (Mississippi, Ganges, Amazon) display a continuous change in shape with size. Detritus from primary sources generally display no size/shape effect. Small rivers commonly exhibit size/shape discontinuities. The origin of a particular size/shape relationship arises from two opposing tendencies. Finer detritus travel much faster than coarser sands. Thus silts from one provenance can overtake coarser material of different provenance. If flood plains are large and long-lived, the contribution of individual tributaries is diluted almost to indetectibility and all sizes have time enough to reach the sea. In such situations the size/shape relationship reflects a steady state of equilibrium. In smaller rivers individual tributaries can provide significant proportions of grains to flood plains with characteristic sizes and shapes leading to discrete shifts in the size/shape curve.

Ehrlich, R.; Eggers, M.R.; Goodman, E.D.

1985-01-01T23:59:59.000Z

359

United Wisconsin Grain Producers UWGP | Open Energy Information  

Open Energy Info (EERE)

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

360

Single Point Turning Process Optimization of Fine Grain Processed ...  

Science Conference Proceedings (OSTI)

wear leads to an increasing required tool load, resulting in increased depth of grain ... of grain distortion, as well as microhardness and residual stress profiles.

Note: This page contains sample records for the topic "grain size distribution" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Grain sorghum response to postemergence applications of mesotrione and quizalofop.  

E-Print Network (OSTI)

??Growth chamber, greenhouse and field experiments using conventional grain sorghum were conducted to 1) evaluate the differential response of grain sorghum hybrids to POST application… (more)

Abit, Mary Joy Manacpo

2010-01-01T23:59:59.000Z

362

Calculation of Grain Boundary Mobility in Slow-Moving Nickel ...  

Science Conference Proceedings (OSTI)

Grain boundaries with a wide range of mobility are selected in this study. .... Grains: Molecular-Dynamics Simulations and In-Situ Electron Microscopy Studies of ...

363

Tendency of Cooperative Grain Boundary Sliding in Nanocrystalline ...  

Science Conference Proceedings (OSTI)

Presentation Title, Tendency of Cooperative Grain Boundary Sliding in ... The objective of this research is to identify the tendency of cooperative grain boundary ...

364

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

Science Conference Proceedings (OSTI)

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.

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

365

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

Science Conference Proceedings (OSTI)

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.

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

366

Stress-Induced Grain Growth in Ultra-Fine Grained 5083 Al during ...  

Science Conference Proceedings (OSTI)

Abstract Scope, Due to the potential for high tonnage manufacturing, the approach to produce ultrafine grained (UFG) materials via mechanical milling has ...

367

Grain growth kinetics and electrical properties of lanthanum modified lead zirconate titanate (9/65/35) based ferroelectric ceramics  

Science Conference Proceedings (OSTI)

The influence of the microstructural characteristics on the dielectric and electrical properties has been investigated for Nd{sup 3+} doped lanthanum modified lead zirconate titanate ferroelectric ceramics, obtained by the conventional solid-state reaction method, by taking into account different sintering conditions. The grain growth mechanism has been investigated and a cubic-type grain growth law was observed for samples with grain size varying from 1.00 up to 2.35 {mu}m. The porosity and grain size dependences of the phase transition parameters, such as the maximum dielectric permittivity and its corresponding temperature ({epsilon}{sub m} and T{sub m}, respectively) were also investigated. The ac conductivity analyses followed the universal Jonscher law. The behavior of the frequency exponent (s) was analyzed through the correlated barrier hopping model. Both ac and dc conductivity results have been correlated with the observed microstructural features.

Roca, R. Alvarez; Guerrero, F. [Departamento de Fisica, Grupo de Ceramicas Ferroeletricas, UFSCar, Rod. Washington Luis, Km 235, CEP 13565-905 Sao Carlos, Sao Paulo (Brazil); Departamento de Fisica, Facultad de Ciencias Naturales, Universidad de Oriente, 90500 Santiago de Cuba (Cuba); Botero, E. R.; Garcia, D.; Eiras, J. A. [Departamento de Fisica, Grupo de Ceramicas Ferroeletricas, UFSCar, Rod. Washington Luis, Km 235, CEP 13565-905 Sao Carlos, Sao Paulo (Brazil); Guerra, J. D. S. [Grupo de Ferroeletricos e Materiais Multifuncionais, Instituto de Fisica, Universidade Federal de Uberlandia, 38400-902 Uberlandia, Minas Gerais (Brazil)

2009-01-01T23:59:59.000Z

368

Characterization of ultra-fine grained aluminum produced by accumulative back extrusion (ABE)  

SciTech Connect

In the present work, the microstructural evolutions and microhardness of AA1050 subjected to one, two and three passes of accumulative back extrusion (ABE) were investigated. The microstructural evolutions were characterized using transmission electron microscopy. The results revealed that applying three passes of accumulative back extrusion led to significant grain refinement. The initial grain size of 47 {mu}m was refined to the grains of 500 nm after three passes of ABE. Increasing the number of passes resulted in more decrease in grain size, better microstructure homogeneity and increase in the microhardness. The cross-section of ABEed specimen consisted of two different zones: (i) shear deformation zone, and (ii) normal deformation zone. The microhardness measurements indicated that the hardness increased from the initial value of 31 Hv to 67 Hv, verifying the significant microstructural refinement via accumulative back extrusion. - Highlights: Black-Right-Pointing-Pointer A significant grain refinement can be achieved in AA1050, Al alloy by applying ABE. Black-Right-Pointing-Pointer Microstructural homogeneity of ABEed samples increased by increasing the number of ABE cycles. Black-Right-Pointing-Pointer A substantial increase in the hardness, from 31 Hv to 67 Hv, was recorded.

Alihosseini, H., E-mail: hamid.alihossieni@gmail.com [Mechanical Engineering Department, University of Tehran, Tehran (Iran, Islamic Republic of); Materials Science and Engineering Department, Engineering School, Amirkabir University, Tehran (Iran, Islamic Republic of); Faraji, G.; Dizaji, A.F. [Mechanical Engineering Department, University of Tehran, Tehran (Iran, Islamic Republic of); Dehghani, K. [Materials Science and Engineering Department, Engineering School, Amirkabir University, Tehran (Iran, Islamic Republic of)

2012-06-15T23:59:59.000Z

369

Fourier grain shape analysis: a means for correlating alluvial deposits at the Nevada Test Site  

SciTech Connect

Quartz sand derived from alluvial fans that drain different lithologies at the Nevada Test Site can be distinguished on the basis of grain shape as described by the Fourier series in closed form. Specifically, we examined tuff units from the Piapi Canyon and Indian Trail Formations as well as carbonate-bearing clastic units from the Eleana Formation. Discrimiation between rock types was accomplished by examining the mean harmonic amplitude spectra and the grain shape frequency distributions at those harmonics that exhibit significant chi-square values. The results of these analyses indicate that the tuffs can be easily distinguished from the clastics. However, differences between samples from genetically similar rock types are not as prominent. Grain shape frequency distributions of tuffs and clastics show such strong differences that they can be characterized by standardized distributions. By comparing the shape frequency distributions of mixed sediment samples, it is possible to determine the relative contribution of tuff and clastics to any sediment sample taken within the drainage network. The Piapi Canyon, Indian Trail, and Eleana Formations have produced the thick alluvium sequence in the Rainier Mesa region of Yucca Flat. We believe it is likely that these grain shape relationships can also be applied to subsurface samples. Not only would this extended application enable more accurate correlation of alluvial layers, but more precise determination of the clastic-tuff contact within the alluvium sequence might also be possible.

Grothaus, B.T.; Hage, G.L.

1978-10-18T23:59:59.000Z

370

ViridiScope: design and implementation of a fine grained power monitoring system for homes  

Science Conference Proceedings (OSTI)

A key prerequisite for residential energy conservation is knowing when and where energy is being spent. Unfortunately, the current generation of energy reporting devices only provide partial and coarse grained information or require expensive professional ... Keywords: adaptive sensor calibration, machine learning, nonintrusive and spatially distributed sensing

Younghun Kim; Thomas Schmid; Zainul M. Charbiwala; Mani B. Srivastava

2009-09-01T23:59:59.000Z

371

Research article: Fine grained sampling of residue characteristics using molecular dynamics simulation  

Science Conference Proceedings (OSTI)

In a fine-grained computational analysis of protein structure, we investigated the relationships between a residue's backbone conformations and its side-chain packing as well as conformations. To produce continuous distributions in high resolution, we ... Keywords: Backbone conformation, Dynameome, Molecular dynamics simulation, Ramachandran plot, Residue volume, Rotamer, Side-chain packing

Hyun Joo; Xiaotao Qu; Rosemarie Swanson; C. Michael McCallum; Jerry Tsai

2010-06-01T23:59:59.000Z

372

1999 Commercial Buildings Characteristics--Building Size  

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

Size of Buildings Size of Buildings Size of Buildings The 1999 CBECS estimated that 2,348,000 commercial buildings, or just over half (50.4 percent) of total buildings, were found in the smallest building size category (1,001 to 5,000 square feet) (Figure 1). Only 7,000 buildings occupied the largest size category (over 500,000 square feet). Detailed tables Figure 1. Distribution of Buildings by Size of Building, 1999 Figure 1. Distribution of Buildings by Size of Building, 1999. If having trouble viewing this page, please contact the National Energy Information Center at (202) 586-8800. Energy Information Administration Commercial Buildings Energy Consumption Survey The middle size categories (10,001 to 100,000 square feet) had relatively more floorspace per category than smaller or larger size categories (Figure 2). The greatest amount of floorspace, about 11,153,000 square feet (or 17 percent of total floorspace) was found in the 10,001 to 25,000 square feet category. Figure 2. Distribution of Floorspace by Size of Building, 1999

373

Midwest Grain Processors MGP | Open Energy Information  

Open Energy Info (EERE)

Midwest Grain Processors MGP Midwest Grain Processors MGP Jump to: navigation, search Name Midwest Grain Processors (MGP) Place Lakota, Iowa Zip 50451 Product Iowa-based bioethanol producer using corn as feedstock. Coordinates 48.042535°, -98.335979° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":48.042535,"lon":-98.335979,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

374

SURFACE GENERATION ANALYSIS IN MICRO END-MILLING CONSIDERING THE INFLUENCES OF GRAIN  

E-Print Network (OSTI)

Micro end-milling method is a universal micro manufacturing method, which can be used to fabricating complex 3D structures and parts with many materials. But compared with their micrometer order size, their surface roughness quality is not satisfied. In this paper, the different metal phase grains influences are researched, and the micro end-milling process is described while the material is anisotropic. In this paper, the physical characteristics of different grains, especially friction coefficient ? and elastic module E, are very critical to determine the chip formation process and surface generation. The chip is often discontinues because of the grain boundary effect. Through the micro end-milling experiment, the bottom surface results correlate very well with the theory analysis. 1.

Jinsheng Wang

2008-01-01T23:59:59.000Z

375

Large grain cavities from pure niobium ingot  

DOE Patents (OSTI)

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.

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

2012-03-06T23:59:59.000Z

376

Microsoft PowerPoint - ARM2007LetterSize.ppt  

NLE Websites -- All DOE Office Websites (Extended Search)

Remote sensing microphysical retrieval and cloud microphysics parameterizations rely on a knowledge of the shape of cloud drop size distributions (DSD). These are often...

377

State Policy: One Size Doesnt Fit All  

Wind Powering America (EERE)

Policy: One Size Doesn't Fit All Larry Flowers Deputy Director, Distributed and Community Wind American Wind Energy Association lflowers@awea.org www.awea.orgcommunitywind...

378

Cat heart Size  

NLE Websites -- All DOE Office Websites (Extended Search)

heart Size Name: Iris Status: student Grade: K-3 Location: OR Country: USA Date: NA Question: Can you tell me the size of a cats heart? Replies: Iris A cat's heart is about the...

379

Cat heart Size  

NLE Websites -- All DOE Office Websites (Extended Search)

Cat heart Size Name: Rebecca Status: student Grade: 6-8 Location: FL Country: USA Date: Spring 2011 Question: What is the average size of a cat's heart? Replies: Hi Rebecca, That...

380

Hopper Job Size Charts  

NLE Websites -- All DOE Office Websites (Extended Search)

charts shows the fraction of hours used on Hopper in each of 5 job-core-size bins. 2012 Usage by Job Size Chart 2011 . This chart shows the fraction of hours used on Hopper by jobs...

Note: This page contains sample records for the topic "grain size distribution" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Effect of grain size on remotely sensed spectral reflectance of sandy desert surfaces  

E-Print Network (OSTI)

into the otherwise stable, armored desert surface. This has resulted in sand plumes, eroded from the fields by wind

Painter, Thomas H.

382

Effect of Hot Deformation Parameters on the Grain Size of Wrought ...  

Science Conference Proceedings (OSTI)

Q. Deng, J. H. Du, Z. Y. Zhong, Z. W. Zhang. Department of ..... Antolovich, R. W. Stusrud, R. A. MacKay, D. L. Anton, T. Khan, R. D. Kissinger, D. L.. Klarstron, The

383

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

E-Print Network (OSTI)

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 ...

Detor, Andrew J. (Andrew Joseph)

2007-01-01T23:59:59.000Z

384

Improved Properties of Ultrafine, Nano, and Multi-Modal Grain Size ...  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2013. Symposium, Commercial Production and Applications of Nanomaterials. Presentation Title ...

385

Effects of Grain and Precipitate Size Variation on Creep-Fatigue ...  

Science Conference Proceedings (OSTI)

temperatures can be maxim&d thus requires a fundamental .... In this study a fundamental examination of the effects ..... ASM suecialitv handbook: Heat resistant.

386

Effect of Starting Grain Size on As-Deformed Microstructure in High ...  

Science Conference Proceedings (OSTI)

This work was conducted by the National Center for Excellence in ... In high temperature deformation of alloy 718, the major event is ... this investigation. The two ...

387

Control of Grain Size Via Forging Strain Rate Limits for R'88DT  

Science Conference Proceedings (OSTI)

R'88DT is a powder metallurgy nickel-based superalloy used for rotating compressor and turbine disks. It was developed using a supersolvus heat treatment to ...

388

The Effect of Grain Size and Strain Rate on Mechanical Properties of ...  

Science Conference Proceedings (OSTI)

D8: Study of Rack and Chord Assembly Formability for Jack-up Platforms ... Zone of Zr-Ti Microalloyed High-strength High-toughness Offshore Structural Steels.

389

Effects of stabilization temperature on surface area and grain size of representative plutonium materials.  

DOE Green Energy (OSTI)

Calcination at 400-1000C is used throughout the Department of Energy (DOE) complex to stabilize plutonium material for transportation and storage . The objectives of this stabilization are to remove moisture and other potentially water-producing phases, and to ensure that readsorption will not occur before material is placed in welded containers .Such moisture may threaten the integrity of containers through pressurization with radiolytically generated hydrogen. It is also considered valuable to reduce the fine (respirable) fraction of the material to mitigate potential impact of accidents.

Boak, J. M. (Jeremy M.); Dale, D. J. (Deborah J.); Eller, P. G. (Phillip Gary)

2003-01-01T23:59:59.000Z

390

Grain Size Prediction of Alloy 718 Billet Forged by Radial Forging ...  

Science Conference Proceedings (OSTI)

... at the surface during forging was also shown in Figure 6. Since the position where the data were taken Bas near the edge in longitudinal direction of the billet

391

THE INFLUENCE OF THE GRAIN STRUCTURE SIZE ON MICROSTRUCTURALLY SHORT CRACKS  

E-Print Network (OSTI)

tensor 0 yield stress () Taylor's resolved shear stress AISI American Iron and Steel Institute CTOD Crack in this paper are typical for the AISI 316L austenitic stainless steel, which is extensively used in nuclear industry (e.g. pipes) and has also been selected for a number of components of the International

Cizelj, Leon

392

Influence of Cold Working and Grain Size on the Pitting Corrosion ...  

Science Conference Proceedings (OSTI)

A Study on the Stress Test of Truck Frames for Freight Trains · A Study on the ... Defect Energetics and Fission Product Transport in ZrC · Deformation Field and ...

393

Prediction of Grain Size During Multiple Pass Radial Forging of Alloy ...  

Science Conference Proceedings (OSTI)

at each end by chuckheads, which are track bound manipulators. When producing round products, the chuckheads rotate the workpiece between blows to ...

394

Abrupt grain boundary melting in ice  

E-Print Network (OSTI)

The effect of impurities on the grain boundary melting of ice is investigated through an extension of Derjaguin-Landau-Verwey-Overbeek theory, in which we include retarded potential effects in a calculation of the full frequency dependent van der Waals and Coulombic interactions within a grain boundary. At high dopant concentrations the classical solutal effect dominates the melting behavior. However, depending on the amount of impurity and the surface charge density, as temperature decreases, the attractive tail of the dispersion force interaction begins to compete effectively with the repulsive screened Coulomb interaction. This leads to a film-thickness/temperature curve that changes depending on the relative strengths of these interactions and exhibits a decrease in the film thickness with increasing impurity level. More striking is the fact that at very large film thicknesses, the repulsive Coulomb interaction can be effectively screened leading to an abrupt reduction to zero film thickness.

L. Benatov; J. S. Wettlaufer

2004-12-30T23:59:59.000Z

395

Ozone and UV for Grain Milling Systems  

Science Conference Proceedings (OSTI)

Recognizing the current concerns with food safety, First Energy Services and EPRI collaborated in a project to investigate the feasibility of using ozone as a substitute for chlorinated water to control bacteria and mold at the Harvest States Amber Milling facility in Huron, Ohio. Traditionally, chlorinated water is used to control bacteria and mold in grain processing. Since chlorine usage can be costly and because chlorine presents problems in storage and safe handling of chlorine gas, the project part...

2000-12-13T23:59:59.000Z

396

Surface and Grain Boundary Segregation in Oxides: Implications for ...  

Science Conference Proceedings (OSTI)

Abstract Scope, A comprehensive understanding of the segregation behavior ... We examine segregation to a series of grain boundaries as well as to free surfaces, ... Atomic-scale Observations of Grain Boundary Structure in Bismuth Telluride.

397

Grain Boundary delta-phase Morphologies, Carbides and Notch ...  

Science Conference Proceedings (OSTI)

penetrates through the grains while, due to the coarser grains, this does not occur in the problem material as ..... 9 of eight edition of Metals Handbook). ... Development, were necessary for the rapidly growing understanding of the fundamental.

398

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

DOE Green Energy (OSTI)

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.

McKamey, C.G.

2002-05-28T23:59:59.000Z

399

Superconductivity in bulk ultrafine-grained metals prepared by high ...  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, 2014 TMS Annual Meeting & Exhibition. Symposium , Ultrafine Grained Materials VIII. Presentation Title, Superconductivity in bulk ...

400

High Throughput Quantification of Grain Boundary Segregation by ...  

Science Conference Proceedings (OSTI)

... by Correlative Transmission Electron Microscopy and Atom Probe Tomography ... Line Tension of Grain Boundary Triple Junctions in the Copper Tricrystals.

Note: This page contains sample records for the topic "grain size distribution" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Grain & Wood Based Technologies for Production of Ethanol  

U.S. Energy Information Administration (EIA)

Outline Sources of Ethanol Grain Based Dry Mill Process Cellulosic Based Processes Costs Conclusions The Production of Ethanol Bioethanol ...

402

Modelling and Grain Boundary Engineering for High Performance ...  

Science Conference Proceedings (OSTI)

... useful information for future development of polysilicon sollar cell with high performance photovoltaic and electric properties by grain boundary engineering,

403

Growth Path Envelope Analysis of Grain Growth in Tungsten  

Science Conference Proceedings (OSTI)

Bayesian inference of grain boundary properties from heterogeneous data · Comparison of Novel Microstructure Quantification Frameworks for Visualization,  ...

404

2D Stochastic-Integral Models for Characterizing Random Grain ...  

Science Conference Proceedings (OSTI)

Bayesian inference of grain boundary properties from heterogeneous data · Comparison of Novel Microstructure Quantification Frameworks for Visualization,  ...

405

Grain Moisture Meter Technical Training - 2013-04-23  

Science Conference Proceedings (OSTI)

Grain Moisture Meter Technical Training. Purpose: This seminar provides participants ... nist.gov. Technical Contact: G. Diane ...

2013-06-03T23:59:59.000Z

406

Grain refinement and texture development of cast bi90sb10 alloy via severe plastic deformation  

E-Print Network (OSTI)

The purpose of this work was to study learn about grain refinement mechanisms and texture development in cast n-type Bi90Sb10 alloy caused by severe plastic deformation. The practical objective is to produce a fine grained and textured microstructure in Bi90Sb10 alloy with enhanced thermoelectric performance and mechanical strength. In the study, twelve millimeter diameter cast bars of Bi90Sb10 alloy were encapsulated in square cross section aluminum 6061 alloy containers. The composite bars were equal channel angular (ECAE) extruded through a 90 degree angle die at high homologous temperature. Various extrusion conditions were studied including punch speed (0.1, 0.3 and 0.6 in/min), extrusion temperature (220, 235 and 250oC), number of extrusion passes (1, 2 and 4), route (A, BC and C), and exit channel area reduction ratio (half and quarter area of inlet channel). The affect of an intermediate long term heat treatment (for 100 hours at 250oC under 10-3 torr vacuum) was explored. Processed materials were characterized by optical microscopy, x-ray diffraction, energy dispersive spectroscopy, wavelength dispersive spectroscopy and scanning electron microscopy. Texture was analyzed using the {006} reflection plane to identify the orientation of the basal poles in processed materials. The cast grains were irregularly shaped, had a grain size of hundreds-of-microns to millimeters, and showed inhomogeneous chemical composition. Severe plastic deformation refines the cast grains through dynamic recrystallization and causes the development of a bimodal microstructure consisting of fine grains (5-30 micron) and coarse grains (50-300 micron). ECAE processing of homogenizied Bi-Sb alloy causes grain refinement and produces a more uniform microstructure. Texture results show that ECAE route C processing gives a similar or slightly stronger texture than ECAE route A processing. In both cases, the basal-plane poles become aligned with the shear direction. Reduction area exit channel extrusion is more effective for both grain refinement and texture enhancement than simple ECAE processing.

Im, Jae-taek

2007-05-01T23:59:59.000Z

407

Cratering Experiments on the Self Armoring of Coarse-Grained Granular Targets  

E-Print Network (OSTI)

Recently published crater statistics on the small asteroids 25143 Itokawa and 433 Eros show a significant depletion of craters below approx. 100 m in diameter. Possible mechanisms that were brought up to explain this lack of craters were seismic crater erasure and self armoring of a coarse, boulder covered asteroid surface. While seismic shaking has been studied in this context, the concept of armoring lacks a deeper inspection and an experimental ground truth. We therefore present cratering experiments of glass bead projectiles impacting into granular glass bead targets, where the grain sizes of projectile and target are in a similar range. The impact velocities are in the range of 200 to 300 m/s. We find that craters become fainter and irregular shaped as soon as the target grains are larger than the projectile sizes and that granular craters rarely form when the size ratio between projectile and target grain is around 1:10 or smaller. In that case, we observe a formation of a strength determined crater in ...

Güttler, Carsten; Nakamura, Akiko M

2012-01-01T23:59:59.000Z

408

GRAIN BOUNDARY STRENGTHENING PROPERTIES OF TUNGSTEN ALLOYS  

SciTech Connect

Density functional theory was employed to investigate grain boundary (GB) properties of W alloys. A range of substitutional solutes across the Periodic Table was investigated to understand the behavior of different electronic orbitals in changing the GB cleavage energy in the ?27a[110]{525} GB. A number of transition metals were predicted to enhance the GB cohesion. This includes Ru, Re, Os, Ir, V, Cr, Mn, Fe, Co, Ti, Hf, Ta and Nb. While lanthanides, s and p elements were tended to cause GB embrittlement.

Setyawan, Wahyu; Kurtz, Richard J.

2012-10-10T23:59:59.000Z

409

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

DOE Patents (OSTI)

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.

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

1996-01-23T23:59:59.000Z

410

On the Effect of the Film Hydrogen Content and Deposition Type on the Grain Nucleation and Grain Growth During Crystallization of a-Si:H Films: Preprint  

SciTech Connect

We report the effect of the initial film hydrogen content (CH) on the crystallization kinetics, crystallite nucleation rate and grain growth rate when HWCVD and PECVD a-Si:H films are crystallized by annealing at 600 C. For the HWCVD films, both the incubation time and crystallization time decrease, and the full width at half maximum (FWHM) of the XRD (111) peak decreases with decreasing film CH. However, other sources of XRD line broadening exist in such materials in addition to crystallite size, including the density of crystallite defects. To address these issues, TEM measurements have also been performed on a-Si:H films deposited directly onto TEM grids.

Mahan, A. H.; Ahrenkiel, S. P.; Roy, B.; Schropp, R.E.I.; Li, H.; Ginley, D. S.

2006-05-01T23:59:59.000Z

411

LETTER doi:10.1038/nature09718 Grains and grain boundaries insingle-layergraphene  

E-Print Network (OSTI)

transferred onto holey silicon nitride or Quantifoil transmission elec- tron microscopy (TEM) grids using two the several billion atoms in each grain, we use diffraction-filtered imaging14 to rapidly map the location sample fabrication20 was the gentle transfer of the gra- phene onto a TEM grid using a minimum of polymer

McEuen, Paul L.

412

The parXXL Environment: Scalable Fine Grained Development for Large Coarse Grained Platforms  

E-Print Network (OSTI)

and datastructure update, that are mandatory to send cell output into con- nected cell input buffers on remote with a paradoxical situation: their modeling and thinking is fine-grained, speaking e.g. of atoms, cells, items collaborations with researchers in optic components and hot plasma (from LMOPS and LPMIA lab- oratories) guide

Vialle, Stéphane

413

High temperature size selective membranes  

DOE Green Energy (OSTI)

The objective of this research is to develop a high temperature size selective membrane capable of separating gas mixture components from each other based on molecular size, using a molecular sieving mechanism. The authors are evaluating two concepts: a composite of a carbon molecular sieve (CMS) with a tightly defined pore size distribution between 3 and 4 {angstrom}, and a microporous supporting matrix which provides mechanical strength and resistance to thermal degradation, and a sandwich of a CMS film between the porous supports. The high temperature membranes the authors are developing can be used to replace the current low-temperature unit operations for separating gaseous mixtures, especially hydrogen, from the products of the water gas shift reaction at high temperatures. Membranes that have a high selectivity and have both thermal and chemical stability would improve substantially the economics of the coal gasification process. These membranes can also improve other industrial processes such as the ammonia production and oil reform processes where hydrogen separation is crucial. Results of tests on a supported membrane and an unsupported carbon film are presented.

Yates, S.F.; Zhou, S.J.; Anderson, D.J.; Til, A.E. van

1994-10-01T23:59:59.000Z

414

Strategy Guideline: HVAC Equipment Sizing  

SciTech Connect

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.

Burdick, A.

2012-02-01T23:59:59.000Z

415

Land animal sizes  

NLE Websites -- All DOE Office Websites (Extended Search)

Land animal sizes Name: tamar c Status: NA Age: NA Location: NA Country: NA Date: Around 1993 Question: Why are today's land mammals so much smaller than prehistoric mammals?...

416

ARM - Measurement - Hydrometeor size  

NLE Websites -- All DOE Office Websites (Extended Search)

size size ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Hydrometeor size The size of a hydrometeor, measured directly or derived from other measurements . Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments DISDROMETER : Impact Disdrometer LDIS : Laser Disdrometer External Instruments CPOL : C-Band Polarimetric Radar Field Campaign Instruments EC-CONVAIR580-BULK : Environment Canada Convair 580 Bulk Parameters

417

A Comprehensive Investigation of Low Angle Grain Boundary ...  

Science Conference Proceedings (OSTI)

Abstract Scope, Grain boundary mobility plays influential role in controlling the ... A New Treatment for the Kinetics of Isothermal Oxidation of Zinc Powders.

418

High Temperature Oxidation Behavior of Grain-refined Inconel 617 ...  

Science Conference Proceedings (OSTI)

The Cr-depleted zone of grain-refined alloy was thicker than that of the ... Intergranular Thermal Residual Strain in Rolled and Texture-free ?-Uranium.

419

The Influence of Grain Boundary Elements on Properties and ...  

Science Conference Proceedings (OSTI)

The 456 and CH98 alloys had been under development in prior programs and were added for comparison. With the above as core compositions, the grain ...

420

Atomistic Simulations of Grain Boundary Associated Distortion in ...  

Science Conference Proceedings (OSTI)

... analysis provides a complete three-dimensional reciprocal space map of the grain ... Imaging: Case Studies in Alloys for Aerospace Propulsion Applications.

Note: This page contains sample records for the topic "grain size distribution" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Livestock and Grain Market News Search | Data.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

Livestock and Grain Market News Search Agriculture Community Menu DATA APPS EVENTS DEVELOPER STATISTICS COLLABORATE ABOUT Agriculture You are here Data.gov Communities ...

422

High Temperature Hold Time Effects on Fine Grain Processed 718 ...  

Science Conference Proceedings (OSTI)

Abstract. Fine Grain Alloy 718 is a relatively cost effective turbine and compressor disk alloy with superior yield strength and low cycle fatigue properties.

423

Monte Carlo Potts Investigation of Dynamic Abnormal Grain Growth  

Science Conference Proceedings (OSTI)

A behavior akin to dynamic abnormal grain growth has been found to occur in model results using small strain rates to achieve modest recrystallization rates.

424

Atomic-scale Characterization of Grain Boundary Embrittlement in ...  

Science Conference Proceedings (OSTI)

The present study was performed determine the grain boundary chemistry in .... Creep of Service-Exposed SUS 316 HTB Superheater Tubes of Fossil Boilers.

425

The Current-voltage Characteristics of Grain Boundaries in Ionic ...  

Science Conference Proceedings (OSTI)

Presentation Title, The Current-voltage Characteristics of Grain Boundaries in Ionic ... A High-temperature Mössbauer Study of Iron-doped Ruddlesden-popper  ...

426

Grain Boundary Characterization of Solid Oxide Fuel Cell Cathode ...  

Science Conference Proceedings (OSTI)

However, little is known about the crystallographic nature of grain boundaries and pore ... Computer Simulations of Realistic Multi-Phase Three-Dimensional ...

427

Ultra Fine Grain/Ultra Low Carbon 718  

Science Conference Proceedings (OSTI)

An ultra low carbon alloy 718 composition has been investigated in combination with ultra fine grain processing to improve the low cycle fatigue capabilities.

428

Tensile Properties of Fine Grain MA956 Oxide Dispersion ...  

Science Conference Proceedings (OSTI)

Presentation Title, Tensile Properties of Fine Grain MA956 Oxide Dispersion ... Weld Overlay Claddings by Gas-metal-arc Welding Process for Extending Plant ...

429

Grain Transportation Report Figure 7 | Data.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

international, export, shipment, carload, railcar auction, unit train, shuttle train, fuel surcharge, port region, grain inspections, ocean freight Dataset Ratings Overall 0 No...

430

Grain Transportation Report Table 7 | Data.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

international, export, shipment, carload, railcar auction, unit train, shuttle train, fuel surcharge, port region, grain inspections, ocean freight Dataset Ratings Overall 0 No...

431

Grain Transportation Report Table 1 | Data.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

international, export, shipment, carload, railcar auction, unit train, shuttle train, fuel surcharge, port region, grain inspections, ocean freight Dataset Ratings Overall 0 No...

432

Grain Transportation Report Figure 16 | Data.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

international, export, shipment, carload, railcar auction, unit train, shuttle train, fuel surcharge, port region, grain inspections, ocean freight Dataset Ratings Overall 0 No...

433

Grain Transportation Report Figure 4, 5, 6 | Data.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

international, export, shipment, carload, railcar auction, unit train, shuttle train, fuel surcharge, port region, grain inspections, ocean freight Dataset Ratings Overall 0 No...

434

Grain Transportation Report Table 16 | Data.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

international, export, shipment, carload, railcar auction, unit train, shuttle train, fuel surcharge, port region, grain inspections, ocean freight Dataset Ratings Overall 0 No...

435

Grain Transportation Report Table 3 | Data.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

international, export, shipment, carload, railcar auction, unit train, shuttle train, fuel surcharge, port region, grain inspections, ocean freight Dataset Ratings Overall 0 No...

436

Grain Transportation Report Figure 15 | Data.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

international, export, shipment, carload, railcar auction, unit train, shuttle train, fuel surcharge, port region, grain inspections, ocean freight Dataset Ratings Overall 0 No...

437

Grain Transportation Report Table 14 | Data.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

international, export, shipment, carload, railcar auction, unit train, shuttle train, fuel surcharge, port region, grain inspections, ocean freight Dataset Ratings Overall 0 No...

438

Grain Transportation Report Table 10 | Data.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

international, export, shipment, carload, railcar auction, unit train, shuttle train, fuel surcharge, port region, grain inspections, ocean freight Dataset Ratings Overall 0 No...

439

Grain Transportation Report Table 17 | Data.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

international, export, shipment, carload, railcar auction, unit train, shuttle train, fuel surcharge, port region, grain inspections, ocean freight Dataset Ratings Overall 0 No...

440

Grain Transportation Report Table 13 | Data.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

international, export, shipment, carload, railcar auction, unit train, shuttle train, fuel surcharge, port region, grain inspections, ocean freight Dataset Ratings Overall 0 No...

Note: This page contains sample records for the topic "grain size distribution" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Grain Transportation Report Table 2 | Data.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

international, export, shipment, carload, railcar auction, unit train, shuttle train, fuel surcharge, port region, grain inspections, ocean freight Dataset Ratings Overall 0 No...

442

Grain Transportation Report Table 8 | Data.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

international, export, shipment, carload, railcar auction, unit train, shuttle train, fuel surcharge, port region, grain inspections, ocean freight Dataset Ratings Overall 0 No...

443

Grain Transportation Report Figure 8 | Data.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

international, export, shipment, carload, railcar auction, unit train, shuttle train, fuel surcharge, port region, grain inspections, ocean freight Dataset Ratings Overall 0 No...

444

Grain Transportation Report Table 5 | Data.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

international, export, shipment, carload, railcar auction, unit train, shuttle train, fuel surcharge, port region, grain inspections, ocean freight Dataset Ratings Overall 0 No...

445

Grain Transportation Report Table 9 | Data.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

international, export, shipment, carload, railcar auction, unit train, shuttle train, fuel surcharge, port region, grain inspections, ocean freight Dataset Ratings Overall 0 No...

446

Grain Transportation Report Figure 17 | Data.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

international, export, shipment, carload, railcar auction, unit train, shuttle train, fuel surcharge, port region, grain inspections, ocean freight Dataset Ratings Overall 0 No...

447

Statistics of Grain Boundary Crystallography in Surrogates for Oxide ...  

Science Conference Proceedings (OSTI)

Presentation Title, Statistics of Grain Boundary Crystallography in Surrogates for ... of TIG Welded and Laser-surface Melted SUS 304 for Nuclear Power Plants.

448

The Structure of Uranium Dioxide Grain Boundaries and its ...  

Science Conference Proceedings (OSTI)

The atomic structures of symmetric ?5 tilt, ?5 twist, and amorphous grain boundaries in uranium dioxide are explored in this work using empirical potentials and ...

449

Effects of Grain Boundary Precipitation on Creep Rupture Properties ...  

Science Conference Proceedings (OSTI)

gas turbine disks 'JU5). For Alloy 706, a stabilizing heat treatment is proposed to improve the creep rupture life, which is performed to produced grain boundary ...

450

The Quantification of Resistance of Grain Boundaries to Short ...  

Science Conference Proceedings (OSTI)

Presentation Title, The Quantification of Resistance of Grain Boundaries to Short Fatigue Crack Propagation in Three-Dimensions in High Strength Al Alloys.

451

Third International Conference on Grain Growth: Rental Car ...  

Science Conference Proceedings (OSTI)

The Third International Conference on Grain Growth (ICGG-3) will be held June 14-19, 1998, in Pittsburgh, Pennsylvania. The conference will deal with all ...

452

Structure and Shear Resistance of an Asymmetric Tilt Grain ...  

Science Conference Proceedings (OSTI)

At high homologous temperatures a grain boundary can either form a disordered structure or ... Atomistic Simulations of Shock-Induced Plasticity in Tantalum.

453

First-Principles Density Functional Theory Study of Grain Boundary ...  

Science Conference Proceedings (OSTI)

Presentation Title, First-Principles Density Functional Theory Study of Grain ... It was found that both the vacancy formation energy and diffusion activation ...

454

Application of Ultra Fine Grain Alloy 718 Forging Billet  

Science Conference Proceedings (OSTI)

tensile properties through material selection and control of final forging grain ..... chemistry controlled, and the system kinetics, which are diffusion controlled.

455

The Mobility of Interfaces and Grain Boundaries from Molecular ...  

Science Conference Proceedings (OSTI)

Presentation Title, The Mobility of Interfaces and Grain Boundaries from Molecular ... A Hybrid Phase-Field / Transmission Electron Microscopy Approach for ...

456

Effects of Grain Boundary Morphology and Dislocation Substructure ...  

Science Conference Proceedings (OSTI)

South Dakota School of Mines & Technology, Rapid City, SD 57701, USA. Abstract. An extensive investigation of the effects of grain boundary morphology.

457

Distributed Sensor Coordination for Advanced Energy Systems  

NLE Websites -- All DOE Office Websites (Extended Search)

Distributed Sensor Coordination for Advanced Energy Systems Background As advanced energy systems grow in size, they require an increasing number of pressure, temperature, and...

458

Size-dependent piezoelectricity  

E-Print Network (OSTI)

In this paper, a consistent theory is developed for size-dependent piezoelectricity in dielectric solids. This theory shows that electric polarization can be generated as the result of coupling to the mean curvature tensor, unlike previous flexoelectric theories that postulate such couplings with other forms of curvature and more general strain gradient terms ignoring the possible couple- stresses. The present formulation represents an extension of recent work that establishes a consistent size-dependent theory for solid mechanics. Here by including scale-dependent measures in the energy equation, the general expressions for force- and couple-stresses, as well as electric displacement, are obtained. Next, the constitutive relations, displacement formulations, the uniqueness theorem and the reciprocal theorem for the corresponding linear small deformation size-dependent piezoelectricity are developed. As with existing flexoelectric formulations, one finds that the piezoelectric effect can also exist in isotrop...

Hadjesfandiari, Ali R

2013-01-01T23:59:59.000Z

459

Sizing and burn time measurements of micron-sized metal powders  

SciTech Connect

Detailed ignition and combustion mechanisms are needed to develop optimized propellant and energetic formulations using micron-sized metal powders, such as aluminum. Combustion researchers have traditionally used relatively coarse metal particles to characterize the burn time dependence on particle size. However, measurements of burn times for particles below 10 {mu}m in diameter are still needed for aluminum powders and other metal fuels. The apparatus described here sizes the particles just before the ignition event, providing a direct correlation between individual particle size and its burn time. Two lasers were utilized: a 785 nm laser diode for sizing the particles and a 125 W CO{sub 2} laser for particle ignition. The particles crossed the 785 nm laser beam just before crossing the CO{sub 2} laser beam. The particle size was determined from the amplitude of the scattered 785 nm light pulse. The burn time was determined from the duration of the visible light emission produced from the ignited particle. The in situ measured particle size distributions compared well with the size distributions measured for the same powders by a commercial instrument using low angle laser light scattering. Our measurements with two nominally spherical aluminum powders, suggest that the burn times increase from 0.5 to {approx}2.5 ms as the particle diameters increase from 3 to 8 {mu}m.

Gill, Robert J.; Mohan, Salil; Dreizin, Edward L. [New Jersey Institute of Technology Newark, New Jersey 07102 (United States)

2009-06-15T23:59:59.000Z

460

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

E-Print Network (OSTI)

Grains, leaves, sheaths, glumes and stalks of sorghum varieties were analyzed for total phenols, condensed tannins, flavan-4-ols, anthocyanins and in vitro antioxidant activity. Black sorghum bran was used to evaluate the effectiveness of organic 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 for polymeric flavonoids (tannins) but not for simple phenols such as flavan-4-ols, 3-deoxyanthocyanins, flavones and flavanones. Simple flavonoids increased antioxidant capacity of sorghum, and were present in all sorghum except for the white pericarp sorghums that did not have flavanones. The "red turning into black" gene increased phenols in Type I sorghum. The leaves, sheath and glumes of sorghum had higher levels of phenols (78-600 times more), with in vitro antioxidant properties than commonly seen in grains. Pigmentation of plant components increased levels of 3- deoxyanthocyanins but not flavones nor flavanones. The leaves of biomass sorghum, Collier variety, had 3.4 times more 3-deoxyanthocyanins than the leaves of Tx430 Black x Sumac which had the highest levels (1810 ?g/g) of 3- deoxyanthocyanins among the leaves. The use of 1% HCl/ethanol provides a possible food grade substitute solvent for 1%HCl/methanol in the extraction of phenolic compounds from sorghum. All enzymes evaluated broke down bran particles forming a gel-like material which had increased phenols and antioxidant activities but not 3- deoxyanthocyanins as revealed by HPLC analysis. Microscopy examination showed the gel matrix rich in fiber and can possibly be used for nutraceutical applications. Careful understanding of enzyme activities is necessary for effective extraction of 3-deoxyanthocyanins from sorghum. Sorghum leaves, sheaths and glumes are excellent sources of bioactive compounds, up to 600 times more than the grains of some varieties. Sorghum with the "red turning to black genes" is a potential source of 3- deoxyanthocyanins and flavan-4-ols. With the trend towards sorghum as biomass for ethanol production, plant breeders must select special traits aimed at developing enhanced desired functionality such as antioxidant potential and other healthy attributes with application in food, pharmaceutical/nutraceutical and cosmetic industries.

Njongmeta, Nenge Lynda A.

2009-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "grain size distribution" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Polycrystalline Grain Controlled Castings for Rotating Compressor ...  

Science Conference Proceedings (OSTI)

X-ray and zyglo quality were found to be satisfactory. Subsequently,. Grainex as well as conventionally cast Mod 5A rotors .... ture limited and sizing is often limited by tensile strength related burst ... of cooling gamma prime, and small discrete.

462

Charge Transport Anisotropy Due to Grain Boundaries in Directionally  

NLE Websites -- All DOE Office Websites (Extended Search)

Charge Transport Anisotropy Due to Grain Charge Transport Anisotropy Due to Grain Boundaries in Directionally Crystallized Thin Films of Regio-Regular Poly(3-hexylthiophene) Semicrystalline polymers, such as polythiophenes, hold much promise as active layers in printable electronic devices such as photovoltaic cells, sensors, and thin film transistors. As organic semiconductors approach commercialization, there is a need to better understand the relationship between charge transport and microstructure, in particular, to identify the inherent bottlenecks to charge transport. In semicrystalline and polycrystalline materials, charge transport is most likely dominated by grain-boundary effects, although the exact mechanism is not well understood. Unfortunately, grain boundaries in semicrystalline thin films are difficult to characterize: the grains are too small to allow for measurements across individual grain boundaries (as is often done for polycrystalline films of small molecules) and bulk measurements are complicated by the unknown orientation of polymer chains within the grain. To better understand the effect of chain orientation on grain boundaries, we use anisotropic thin films of poly(3-hexylthiophene) (P3HT) - one of the most well-studied polymeric semiconductors, as a tool to study charge transport.

463

Flexible Hardware Acceleration for Instruction-Grain Program Monitoring  

Science Conference Proceedings (OSTI)

Instruction-grain program monitoring tools, which check and analyze executing programs at the granularity of individual instructions, are invaluable for quickly detecting bugs and security attacks and then limiting their damage (via containment and/or ... Keywords: Log-Based Architectures, LBA, Instruction-grain Program Monitoring, Hardware Acceleration, Inheritance Tracking, Idempotent Filter, Metadata-TLB, Lifeguards

Shimin Chen; Michael Kozuch; Theodoros Strigkos; Babak Falsafi; Phillip B. Gibbons; Todd C. Mowry; Vijaya Ramachandran; Olatunji Ruwase; Michael Ryan; Evangelos Vlachos

2008-06-01T23:59:59.000Z

464

The equilibrium probability distribution of a conductive sphere's floating charge in a collisionless, drifting Maxwellian plasma  

E-Print Network (OSTI)

A dust grain in a plasma has a fluctuating electric charge, and past work concludes that spherical grains in a stationary, collisionless plasma have an essentially Gaussian charge probability distribution. This paper extends that work to flowing plasmas and arbitrarily large spheres, deriving analytic charge probability distributions up to normalizing constants. We find that these distributions also have good Gaussian approximations, with analytic expressions for their mean and variance.

Thomas, Drew M

2013-01-01T23:59:59.000Z

465

Particle Size Analysis of Multimodal Gamma-Prime (?') Distributions ...  

Science Conference Proceedings (OSTI)

Evolution of Internal Strain with Temperature in Depleted Uranium in the Presence of Hydrides · EXAFS Study of Local Atomic Environment in Annealed and ...

466

Certification of SRM 114q: Part II (Particle size distribution)  

Science Conference Proceedings (OSTI)

... LA: Ronald J. Rajki California Portland Cement ... Mitsubishi Cement Corp., Lucerne Valley, CA: Tom ... of diffracted light around the central beam can ...

2006-12-07T23:59:59.000Z

467

The geographic distribution of mammal body size in Europe  

E-Print Network (OSTI)

palaeo/ice_topo. 2 Heat conservation — grid cell averages ofgrid cell from data available at: http:// www.ngdc.noaa.gov/seg/cdroms/ged_iia/datasets/a13/fnoc.htm. 3 Heat

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

2006-01-01T23:59:59.000Z

468

Comments on "Modelling the gap size distribution of parked cars"  

E-Print Network (OSTI)

In this Comment we discuss some points concerning the modeling of parked cars proposed in the article by Rawal and Rodgers, Physica A (2005). We also introduce another approach to this problem which leads to a better description of the empirical data collected by the authors.

Girardi, Mauricio

2009-01-01T23:59:59.000Z

469

Size Distribution, Imaging and Growth Mechanisms of Self ...  

Science Conference Proceedings (OSTI)

The growth of self-assembled quantum-confined structures has been under ... being developed to better understand the formation of quantum dots and wires.

470

The Echo Size Distribution of Precipitating Shallow Cumuli  

Science Conference Proceedings (OSTI)

S-band radar surveillance scans of precipitating shallow convection are analyzed. The scans are complied from 52 days of near-continuous measurements in the winter trades of the North Atlantic during the Rain in Cumulus over the Ocean (RICO) ...

Panu Trivej; Bjorn Stevens

2010-03-01T23:59:59.000Z

471

Performance Profiles Table Browser: T-10. Size Distribution of Net ...  

U.S. Energy Information Administration (EIA)

Crude oil, gasoline, heating oil, diesel, propane, and other liquids including biofuels and natural gas liquids. Natural Gas. Exploration and reserves, storage, ...

472

Theory of Nanocluster Size Distributions from Ion Beam Synthesis  

E-Print Network (OSTI)

the implanted species/matrix interface energy. PACS numbers:on the interface energy between the matrix and the implantedenergy between the implanted species and the matrix. The

Yuan, C.W.

2009-01-01T23:59:59.000Z

473

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

NLE Websites -- All DOE Office Websites (Extended Search)

National Laboratory Upton, New York Introduction Most studies of the effect of aerosols on cloud radiative properties have considered only changes in the cloud droplet...

474

Certification of SRM 114q: Part II (Particle size distribution)  

Science Conference Proceedings (OSTI)

... Physical and Chemical Properties2 • Analytical Chemistry ... and Conformance Testing • Statistical Engineering ... and the requirements for sample ...

2011-08-04T23:59:59.000Z

475

Understanding the Spectral Energy Distributions of the Galactic Star Forming Regions IRAS 18314-0720, 18355-0532 & 18316-0602  

E-Print Network (OSTI)

Embedded Young Stellar Objects (YSO) in dense interstellar clouds is treated self-consistently to understand their spectral energy distributions (SED). Radiative transfer calculations in spherical geometry involving the dust as well as the gas component, have been carried out to explain observations covering a wide spectral range encompassing near-infrared to radio continuum wavelengths. Various geometric and physical details of the YSOs are determined from this modelling scheme. In order to assess the effectiveness of this self-consistent scheme, three young Galactic star forming regions associated with IRAS 18314-0720, 18355-0532 and 18316-0602 have been modelled as test cases. They cover a large range of luminosity ($\\approx$ 40). The modelling of their SEDs has led to information about various details of these sources, e.g. embedded energy source, cloud structure & size, density distribution, composition & abundance of dust grains etc. In all three cases, the best fit model corresponds to the uniform density distribution.

Bhaswati Mookerjea; S. K. Ghosh

1999-06-28T23:59:59.000Z

476

Intra- and inter-grain currents in coated conductors with arbitrary grain boundary properties from magnetic measurements  

Science Conference Proceedings (OSTI)

A generalized methodology is described for determining both the intragranular and through-grain-boundary critical current densities in practical coated conductors from contact-free magnetic hysteresis measurements. The model incorporates the vector nature of current density J within the superconducting grains and current conservation with respect to the grain boundaries. Using physically observed values for the grain aspect ratio as input, the analysis yields the low-field intragranular critical current density J{sub c}{sup G} from a single field-dependent measurement of the global J{sub c} and provides a consistent description that spans the entire range from the weak-link (J{sub c}/J{sub c}{sup G}) to the single-grain (J{sub c}/J{sub c}{sup G} {yields} 1) limit. Results are given for ex situ processed RBCO coatings on RABiTS.

Feenstra, Roeland [ORNL; Sinclair IV, John W [ORNL; Thompson, James R [ORNL; Christen, David K [ORNL

2011-01-01T23:59:59.000Z

477

Linking Grain Boundary Microstructure to Stress Corrosion Cracking of Cold Rolled Alloy 690 in PWR Primary Water  

SciTech Connect

Grain boundary microstructures and microchemistries are examined in cold-rolled alloy 690 tubing and plate materials and comparisons are made to intergranular stress corrosion cracking (IGSCC) behavior in PWR primary water. Chromium carbide precipitation is found to be a key aspect for materials in both the mill annealed and thermally treated conditions. Cold rolling to high levels of reduction was discovered to produce small IG voids and cracked carbides in alloys with a high density of grain boundary carbides. The degree of permanent grain boundary damage from cold rolling was found to depend directly on the initial IG carbide distribution. For the same degree of cold rolling, alloys with few IG precipitates exhibited much less permanent damage. Although this difference in grain boundary damage appears to correlate with measured SCC growth rates, crack tip examinations reveal that cracked carbides appeared to blunt propagation of IGSCC cracks in many cases. Preliminary results suggest that the localized grain boundary strains and stresses produced during cold rolling promote IGSCC susceptibility and not the cracked carbides and voids.

Bruemmer, Stephen M.; Olszta, Matthew J.; Toloczko, Mychailo B.; Thomas, Larry E.

2012-10-01T23:59:59.000Z

478

Thickness measurement and crease detection of wheat grains using stereo vision  

Science Conference Proceedings (OSTI)

Wheat grain quality assessment is important in meeting market requirements. The thickness of grains can be used for the measurement of the mass proportion of grains that pass through a sieve. This measure is known as ''screenings''. The determination ... Keywords: Grain crease detection, Grain thickness measurement, Stereo vision

Changming Sun; Mark Berman; David Coward; Brian Osborne

2007-09-01T23:59:59.000Z

479

Genetic algorithm for optimal capacitor allocation in radial distribution systems  

Science Conference Proceedings (OSTI)

Optimum location and size of capacitors for a radial distribution system is presented. In the present study capacitor sizes are assumed as discrete known variables, which are to be placed on the buses such that it reduces the losses of the distribution ... Keywords: capacitor placement, distribution automation (DA), genetic algorithm (GA), loss minimisation, optimisation, power distribution system

K. S. Swarup

2005-06-01T23:59:59.000Z

480

Equitable distribution  

Science Conference Proceedings (OSTI)

The problem of distributing available resources occurs in a great variety of networks, each with peculiarities of its own. Coal from mines has to be distributed to central dumps and to small yards. Ice cream must be distributed only to refrigerated stores ...

John A. Gosden

1963-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "grain size distribution" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

Ductless Hydronic Distribution  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

DUCTLESS HYDRONIC DUCTLESS HYDRONIC DISTRIBUTION Alliance for Residential Building Innovation David Springer, Davis Energy Group Context  Target: Builders of high performance new homes & deep retrofits  Why is this technology key to meeting performance goals of future homes?  Distribution Efficiency * Distribution efficiency for well insulated, tight ducts in attics ≈ 85% * Duct energy losses drives placement of ducts inside conditioned space, which adds cost and interferes with structure and architecture * Ductless hydronic systems can approach 100% distribution efficiency; piping needs little space  Delivery Energy * Fans: 0.58 W/cfm or 9 (heating) to 27 (cooling) W/kBtuh * Pumps: 8 W/gpm, or 0.8 W/kBtuh Context  Sizing * Conventional systems tend to be too large for low load homes

482

FIRST LABORATORY OBSERVATION OF SILICA GRAINS FROM CORE COLLAPSE SUPERNOVAE  

SciTech Connect

We report the discovery of two supernova silica (SiO{sub 2}) grains in the primitive carbonaceous chondrites LaPaZ 031117 and Grove Mountains 021710. Only five presolar silica grains have been previously reported from laboratory measurements but they all exhibit enrichments in {sup 17}O relative to solar, indicating origins in the envelopes of asymptotic giant branch stars. The two SiO{sub 2} grains identified in this study are characterized by moderate enrichments in {sup 18}O relative to solar, indicating that they originated in Type II supernova ejecta. If compared to theoretical models, the oxygen isotopic compositions of these grains can be reproduced by mixing of different supernova zones. While both theoretical models of grain condensation and recent NASA Spitzer Space Telescope observations have suggested the presence of silica in supernova ejecta, no such grains had been identified, until now, in meteorites. The discovery of these two silica grains provides definitive evidence of the condensation of silica dust in supernova ejecta.

Haenecour, Pierre; Floss, Christine; Zinner, Ernst [Laboratory for Space Sciences, McDonnell Center for the Space Sciences and Physics Department, Washington University, One Brookings Drive, St. Louis, MO 63130-4899 (United States); Zhao Xuchao; Lin Yangting, E-mail: haenecour@wustl.edu [Key Laboratory of the Earth's Deep Interior, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029 (China)

2013-05-01T23:59:59.000Z

483

Climate Sensitivity to Continental Ice Sheet Size and Configuration  

Science Conference Proceedings (OSTI)

A version of the NCAR Community Climate Model (CCM) has been used to carry out a study of climate sensitivity to the size and distribution of continental ice sheets by comparing two perpetual season, fixed sea surface temperature (SST), winter ...

Richard A. Shinn; Eric J. Barron

1989-12-01T23:59:59.000Z

484

Microphysics of Raindrop Size Spectra: Tropical Continental and Maritime Storms  

Science Conference Proceedings (OSTI)

This work uses raindrop size spectra measured at the surface in tropical continental storms to determine the associated parameters of the best-fit gamma distributions. The physical processes responsible for those parameters and their relations to ...

Carlton W. Ulbrich; David Atlas

2007-11-01T23:59:59.000Z

485

Size separation in vibrated granular matter  

E-Print Network (OSTI)

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.

A. Kudrolli

2004-02-06T23:59:59.000Z

486

Velocity-Dependent Friction and Diffusion for Grains in Neutral Gases, Dusty Plasmas and Active Systems  

E-Print Network (OSTI)

A self-consistent and universal description of friction and diffusion for Brownian particles (grains) in different systems, as a gas with Boltzmann collisions, dusty plasma with ion absorption by grains, and for active particles (e.g., cells in biological systems) is suggested on the basis of the appropriate Fokker-Planck equation. Restrictions for application of the Fokker-Planck equation to the problem of velocity-dependent friction and diffusion coefficients are found. General description for this coefficient is formulated on the basis of master equation. Relation of the diffusion coefficient in the coordinate and velocity spaces is found for active (capable to transfer momentum to the ambient media) and passive particles in the framework of the Fokker-Planck equation. The problem of anomalous space diffusion is formulated on the basis of the appropriate probability transition (PT) function. The method of partial differentiation is avoided to construct the correct probability distributions for arbitrary distances, what is important for applications to different stochastic problems. Generale equation for time-dependent PT function is formulated and discussed. Generalized friction in the velocity space is determined and applied to describe the friction force itself as well as the drag force in the case of a non-zero driven ion velocity in plasmas. The negative friction due to ion scattering on grains exists and can be realized for the appropriate experimental conditions.

S. A. Trigger; G. J. F. van Heijst; P. P. J. M. Schram

2004-01-19T23:59:59.000Z

487

Velocity-Dependent Friction and Diffusion for Grains in Neutral Gases, Dusty Plasmas and Active Systems  

E-Print Network (OSTI)

A self-consistent and universal description of friction and diffusion for Brownian particles (grains) in different systems, as a gas with Boltzmann collisions, dusty plasma with ion absorption by grains, and for active particles (e.g., cells in biological systems) is suggested on the basis of the appropriate Fokker-Planck equation. Restrictions for application of the Fokker-Planck equation to the problem of velocity-dependent friction and diffusion coefficients are found. General description for this coefficient is formulated on the basis of master equation. Relation of the diffusion coefficient in the coordinate and velocity spaces is found for active (capable to transfer momentum to the ambient media) and passive particles in the framework of the Fokker-Planck equation. The problem of anomalous space diffusion is formulated on the basis of the appropriate probability transition (PT) function. The method of partial differentiation is avoided to construct the correct probability distributions for arbitrary distances, what is important for applications to different stochastic problems. Generale equation for time-dependent PT function is formulated and discussed. Generalized friction in the velocity space is determined and applied to describe the friction force itself as well as the drag force in the case of a non-zero driven ion velocity in plasmas. The negative friction due to ion scattering on grains exists and can be realized for the appropriate experimental conditions.

S. A. Trigger; G. J. F. Van Heijst; P. P. J. M. Schram

2004-01-01T23:59:59.000Z

488

Distribution Screening for Distributed Generation  

Science Conference Proceedings (OSTI)

As the deployment of renewable distributed generation increases, the need for traditional energy providers to interact with these resources increases. Detailed modeling and simulation of the distribution and distributed resources is a critical element to better analyze, understand and predict these interactions. EPRI has developed a tool for such analysis called OpenDSS. In addition, as part of the renewable integration program an applet was created for screening distributed generation (DG). This report ...

2009-12-23T23:59:59.000Z

489

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

Science Conference Proceedings (OSTI)

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.

Uberuaga, Blas P. [Los Alamos National Laboratory

2012-05-02T23:59:59.000Z

490

Generative Historical Model of City Size Hierarchies: 430 BCE –  

E-Print Network (OSTI)

Despite the enormous changes in city size and differentiation of functions over time and space, and discontinuities in growth processes, key spatio-temporal and distributional processes shaping city sizes are often assumed to remain invariant. We demonstrate in this article that most of the facile assumptions about such invariance, that is, constancy over long historical periods, are unsupported when comparisons are made concerning

Douglas R. White; Constantino Tsallis; Céline Rozenblat December

2005-01-01T23:59:59.000Z

491

Structural Characterization of SiF4, SiH4 and H2 Hot-Wire-Grown Microcrystalline Silicon Thin Films with Large Grains  

E-Print Network (OSTI)

of Physics, University of Utah Salt Lake City, UT 84112, U.S.A. 2 MVSystems Golden, CO 80401, U.S.A. ABSTRACT by a novel growth process intended to maximize their grain size and crystal volume fraction. Using Atomic with different deposition conditions. X ray diffraction, Raman spectroscopy, and Atomic Force Microscopy (AFM

Inglefield, Colin

492

Grain-Boundary Physics in Polycrystalline Photovoltaic Materials: Preprint  

DOE Green Energy (OSTI)

This paper describes a study of the atomic structure and electronic effects of grain boundaries in polycrystalline photovoltaic materials such as Si, CdTe, CuInSe2, and CuGaSe2.

Yan, Y.; Jiang, C. S.; Wu, X. Z.; Noufi, R.; Wei, S. H.; Al-Jassim, M. M.

2008-05-01T23:59:59.000Z

493

A performance model for fine-grain accesses in UPC  

Science Conference Proceedings (OSTI)

UPC's implicit communication and fine-grain programming style make application performance modeling a challenging task. The correspondence between remote references and communication events depends on the internals of the compiler and runtime system. ...

Zhang Zhang; Steven R. Seidel

2006-04-01T23:59:59.000Z

494

Grain Core Dielectric Constants of Acceptor-doped Oxide Electrolytes  

Science Conference Proceedings (OSTI)

Author(s), Nicola H. Perry, Ted C. Yeh, Thomas O. Mason. On-Site Speaker ... Water Uptake and Conduction Property of Nano-grained Fluorite-type Oxides.

495

Elastic Strain Energy Effects on Grain Boundary Segregation and ...  

Science Conference Proceedings (OSTI)

Symposium, Integrated Computational Materials Engineering: Modeling and Simulation Applied to Metals Processing. Presentation Title, Elastic Strain Energy Effects on Grain Boundary ... Diffusivity and Mobility Data: Building Blocks for ICME.

496

Crystal Size and Orientation in Ice Grown by Droplet Accretion in Wet and Spongy Regimes  

Science Conference Proceedings (OSTI)

The size and orientation of crystal grains in wet and spongy ice formed by accretion of supercooled droplets has been determined in a wide range of air temperatures (?8 to ?25°C). Particular care has been taken in reducing the spurious ice ...

F. Prodi; L. Levi; A. Franzini; C. Scarani

1982-10-01T23:59:59.000Z

497

Ratooning Grain Sorghum on the Texas Gulf Coast  

E-Print Network (OSTI)

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 of the main crop. This publication discusses important factors to consider when contemplating a ratoon crop, including water stress, grain quality, insect problems, bird problems and marketing.

Livingston, Stephen; Coffman, Cloyce G.

1997-01-03T23:59:59.000Z