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1

Fugitive Emissions | Department of Energy  

Office of Environmental Management (EM)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "of Energy Power.pdf11-161-LNG | Department of Energy Freeport LNG Expansion, L.P.FuelFugitive Emissions

2

Estimation and Reduction Methodologies for Fugitive Emissions from Equipment  

E-Print Network [OSTI]

.0214 Compressor Seals Gas/Vapor 0.228 Pressure Relief Seals Gas/Vapor 0.104 Flanges All 0.00083 Open-Ended Lines All 0.0017 Sampling Connections All 0.0150 Table 1. Average Emission Factors for Fugitive Emissions (kg/hr/source). The product of the emission...Tssion Factor Emission Factor Val ves Gas a LLb HL c 0.0451 0.0852 0.00023 d 0.00048 0.00171 0.00023 Pump Sea Is LL HL 0.437 0.3885 0.0120 0.0135 Compressor Seal se Pressure ReI ief Valves Flanges Open -Ended Lines Gas Gas All All 1...

Scataglia, A.

3

Earth'sFuture Remote sensing of fugitive methane emissions from oil and  

E-Print Network [OSTI]

Earth'sFuture Remote sensing of fugitive methane emissions from oil and gas production in North and tight oil reservoirs to exploit formerly inaccessible or unprofitable energy resources in rock and oil provide an opportunity to achieve energy self-sufficiency and to reduce greenhouse gas emissions

Dickerson, Russell R.

4

Capturing Fugitives to Reduce DOE's GHG Emissions | Department of Energy  

Office of Environmental Management (EM)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "of Energy Power Systems EngineeringDepartment of4 Federal6CleanCaithness ShepherdsCapturing Fugitives to

5

Fugitive SO{sub 2} and particulate emissions from a smelter complex  

SciTech Connect (OSTI)

Emissions released into the local air shed from industrial facilities typically fall into one of two categories, namely point or fugitive sources. The first refers to emissions released directly through stacks or similar devices designed to direct or control emissions. These emissions are readily measured with the aid of standard stack sampling methods or techniques. The latter refers to emissions released into the atmosphere without control of flow or quantities that cannot be measured directly or easily using standard methods. As part of Falconbridge`s efforts to minimize the environmental impact on the community, a fugitive emission monitoring program was designed and implemented to quantify SO{sub 2} and particulate emissions during routine process operations at the Smelter Plant. The monitoring program consisted of simultaneous and continuous temperature and velocity measurements along with continuous SO{sub 2} monitoring and semi-continuous particulate measurements at 8 locations along the Roof Monitor. These measurements were made over 6 days, 24 hours per day. The emission data were correlated with process information and activities to statistically determine the contribution of each process to the emission inventory.

Ciccone, A. [BOVAR Environmental, Toronto, Ontario (Canada); Storbeck, J. [Falconbridge Ltd., Ontario (Canada)

1997-12-31T23:59:59.000Z

6

QUANTIFICATION OF FUGITIVE REACTIVE ALKENE EMISSIONS FROM PETROCHEMICAL PLANTS WITH PERFLUOROCARBON TRACERS.  

SciTech Connect (OSTI)

Recent studies demonstrate the impact of fugitive emissions of reactive alkenes on the atmospheric chemistry of the Houston Texas metropolitan area (1). Petrochemical plants located in and around the Houston area emit atmospheric alkenes, such as ethene, propene and 1,3-butadiene. The magnitude of emissions is a major uncertainty in assessing their effects. Even though the petrochemical industry reports that fugitive emissions of alkenes have been reduced to less than 0.1% of daily production, recent measurement data, obtained during the TexAQS 2000 experiment indicates that emissions are perhaps a factor of ten larger than estimated values. Industry figures for fugitive emissions are based on adding up estimated emission factors for every component in the plant to give a total estimated emission from the entire facility. The dramatic difference between estimated and measured rates indicates either that calculating emission fluxes by summing estimates for individual components is seriously flawed, possibly due to individual components leaking well beyond their estimated tolerances, that not all sources of emissions for a facility are being considered in emissions estimates, or that there are known sources of emissions that are not being reported. This experiment was designed to confirm estimates of reactive alkene emissions derived from analysis of the TexAQS 2000 data by releasing perfluorocarbon tracers (PFTs) at a known flux from a petrochemical plant and sampling both the perfluorocarbon tracer and reactive alkenes downwind using the Piper-Aztec research aircraft operated by Baylor University. PFTs have been extensively used to determine leaks in pipelines, air infiltration in buildings, and to characterize the transport and dispersion of air parcels in the atmosphere. Over 20 years of development by the Tracer Technology Center (TTC) has produced a range of analysis instruments, field samplers and PFT release equipment that have been successfully deployed in a large variety of experiments. PFTs are inert, nontoxic, noncombustible and nonreactive. Up to seven unique PFTs can be simultaneously released, sampled and analyzed and the technology is well suited for determining emission fluxes from large petrochemical facilities. The PFT experiment described here was designed to quantitate alkene emissions from a single petrochemical facility, but such experiments could be applied to other industrial sources or groups of sources in the Houston area.

SENUM,G.I.; DIETZ,R.N.

2004-06-30T23:59:59.000Z

7

Control technology of vinyl chloride in EDC-VCM and PVC plants at main source points and fugitive emissions  

E-Print Network [OSTI]

in a boiler and the combustion gases scrubbed with water or a caustic solution to remove the hydrogen chloride to form hydrochloric acid or sodium chloride. According to the Trane Thermal Company, thermal incineration is a basic proven process... and fugitive emissions, (b) collection of data by using a questionaire ? survey from industries located in the United States, and (c) a statistical analysis of the data. It was found that thermal incineration is considered the best approach to control...

Parra, Dario Antonio

1983-01-01T23:59:59.000Z

8

Department of Earth Sciences www.rhul.ac.uk/earthsciences Page 1 of 2 Fugitive Methane Emissions in the UK and their Impacts on the Urban  

E-Print Network [OSTI]

Department of Earth Sciences www.rhul.ac.uk/earthsciences Page 1 of 2 Fugitive Methane Emissions James France, Prof Euan Nisbet Project Description: Methane is the second most important greenhouse gas amounts from vehicles, with emissions from landfills, ruminants and in some areas, coal mines

Sheldon, Nathan D.

9

Dust Emission from the Perseus Molecular Cloud  

E-Print Network [OSTI]

Using far-infrared emission maps taken by IRAS and Spitzer and a near-infrared extinction map derived from 2MASS data, we have made dust temperature and column density maps of the Perseus molecular cloud. We show that the emission from transiently heated very small grains and the big grain dust emissivity vary as a function of extinction and dust temperature, with higher dust emissivities for colder grains. This variable emissivity can not be explained by temperature gradients along the line of sight or by noise in the emission maps, but is consistent with grain growth in the higher density and lower temperature regions. By accounting for the variations in the dust emissivity and VSG emission, we are able to map the temperature and column density of a nearby molecular cloud with better accuracy than has previously been possible.

S. Schnee; J. Li; A. A. Goodman; A. I. Sargent

2008-05-27T23:59:59.000Z

10

Extended silicate dust emission in PG QSOs  

E-Print Network [OSTI]

This paper addresses the origin of the silicate emission observed in PG QSOs, based on observations with the Spitzer Space Telescope. Scenarios based on the unified model suggest that silicate emission in AGN arises mainly from the illuminated faces of the clouds in the torus at temperatures near sublimation. However, detections of silicate emission in Type 2 QSOs, and the estimated cool dust temperatures, argue for a more extended emission region.To investigate this issue we present the mid-infrared spectra of 23 QSOs. These spectra, and especially the silicate emission features at ~10 and ~18 mu can be fitted using dusty narrow line region (NLR) models and a combination of black bodies. The bolometric luminosities of the QSOs allow us to derive the radial distances and covering factors for the silicate-emitting dust. The inferred radii are 100-200 times larger than the dust sublimation radius, much larger than the expected dimensions of the inner torus. Our QSO mid-IR spectra are consistent with the bulk of the silicate dust emission arising from the dust in the innermost parts of the NLR.

M. Schweitzer; B. Groves; H. Netzer; D. Lutz; E. Sturm; A. Contursi; R. Genzel; L. J. Tacconi; S. Veilleux; D. -C. Kim; D. Rupke; A. J. Baker

2008-01-30T23:59:59.000Z

11

Leak Detection/Fugitive Emissions Monitoring and Advanced Sensors, Controls, Models and Platforms Panel  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeatMulti-Dimensionalthe10 DOEWashington,LM-04-XXXXLocated and Methane Emissions

12

Secondary Electron Emission from Dust and Its Effect on Charging  

SciTech Connect (OSTI)

Hydrogen plasma is produced in a plasma chamber by striking discharge between incandescent tungsten filaments and the permanent magnetic cage [1], which is grounded. The magnetic cage has a full line cusped magnetic field geometry used to confine the plasma elements. A cylindrical Langmuir probe is used to study the plasma parameters in various discharge conditions. The charge accumulated on the dust particles is calculated using the capacitance model and the dust current is measured by the combination of a Faraday cup and an electrometer at different discharge conditions. It is found Secondary electron emission from dust having low emission yield effects the charging of dust particles in presence of high energetic electrons.

Saikia, B. K.; Kakati, B.; Kausik, S. S. [Centre of Plasma Physics, Institute for Plasma Research, Nazirakhat, Sonapur-782402, Assam (India); Bandyopadhyay, M. [ITER-India, Institute for Plasma Research, Bhat, Gandhinagar-382 428 (India)

2011-11-29T23:59:59.000Z

13

Evaluating point and process fugitive emission sources of particulate matter from feed mills associated with cattle feed yards  

E-Print Network [OSTI]

. 843 kg/m' (0. 0526 lb/ft') and 2688 m/min (8820 fpm), respectively. Since the dimensions of the rectangular exhaust duct were 27. 9x35. 6 cendmeters (I lx14 inches), the volume rate of flow of air handled by this cyclone was determined to be 267 m.... Emission factors for feed mills (Shannon et al. , 1974) Table 2. 1988 AP-42 emission factors for feed mills Table 3. Intemn AP-42 emission actors for grain elevators 12 Table 4. Proposed emission factors for feed mills 14 Table 5. Source sampling...

Demny, Michael Alan

2012-06-07T23:59:59.000Z

14

Reducing dust emissions at OAO Alchevskkoks coke battery 10A  

SciTech Connect (OSTI)

Coke battery 10A with rammed batch is under construction at OAO Alchevskkoks. The design documentation developed by Giprokoks includes measures for reducing dust emissions to the atmosphere. Aspiration systems with dry dust trapping are employed in the new components of coke battery 10A and in the existing coke-sorting equipment. Two-stage purification of dusty air in cyclones and bag filters is employed for the coke-sorting equipment. This system considerably reduces coke-dust emissions to the atmosphere.

T.F. Trembach; E.N. Lanina [Giprokoks, the State Institute for the Design of Coke-Industry Enterprises, Kharkov (Ukraine)

2009-07-15T23:59:59.000Z

15

1995 Study and evaluation of fugitive and diffuse emissions from the 200 East Area at the Hanford Site  

SciTech Connect (OSTI)

The objective of this study is to evaluate Hanford`s major diffuse emission sources in the 200 East Area and evaluate the effectiveness of monitoring these sources collectively. The results from this evaluation may also be utilized to demonstrate Westinghouse`s compliance status with the applicable air emissions regulations and determine if additional studies and/or evaluations are necessary. Air sampling will be conducted downwind of the 200 East Area. This site has been chosen as being representative of most large diffuse sources located on the Hanford waste sites. A review of the 1993 ambient air data indicated that {sup 137}C was detectable in this area. This study will take place during February to August of 1995. This time period will enable the collection of sufficient data to assess diffuse radionuclide emissions from the 200 East Area waste sites. This study will use existing ambient air monitoring stations supplemented with temporary air monitoring stations. Plots of the 1993 average concentrations of {sup 137}Cs and {sup 90}Sr collected from the existing stations may be found in Appendix A. Upon completion of this evaluation a recommendation will be made to perform additional sampling studies, or to discontinue further data gathering based on the evaluation`s results.

Schmidt, J.W.; Gleckler, B.P.

1995-01-03T23:59:59.000Z

16

Evaluation of fly ash-surfaced pens as a control for fugitive dust emissions from beef cattle feedyards  

E-Print Network [OSTI]

of pens was surfaced with fly ash from a coal-fired power plant, while the other set, surfaced with caliche, served as a control. Five sampling trips were completed for a total of 492 TSP samples and 288 PM10 samples. Results indicate that statistically...

Kantor, Theodore Lee

1995-01-01T23:59:59.000Z

17

Toward resolution-independent dust emissions in global models: Impacts on the seasonal and spatial distribution of dust  

E-Print Network [OSTI]

Simulating the emission of mineral dust and sea-salt aerosol is nonlinear with surface winds and therefore requires accurate representation of surface winds. Consequently, the resolution of a simulation affects emission ...

Pierce, J. R.

18

DUST EMISSION AND STAR FORMATION IN STEPHAN'S QUINTET  

SciTech Connect (OSTI)

We analyze a comprehensive set of MIR/FIR observations of Stephan's Quintet (SQ), taken with the Spitzer Space Telescope. Our study reveals the presence of a luminous (L{sub IR} {approx} 4.6 x 10{sup 43} erg s{sup -1}) and extended component of infrared dust emission, not connected with the main bodies of the galaxies, but roughly coincident with the X-ray halo of the group. We fitted the inferred dust emission spectral energy distribution of this extended source and the other main infrared emission components of SQ, including the intergalactic shock, to elucidate the mechanisms powering the dust and polycyclic aromatic hydrocarbon emission, taking into account collisional heating by the plasma and heating through UV and optical photons. Combining the inferred direct and dust-processed UV emission to estimate the star formation rate (SFR) for each source we obtain a total SFR for SQ of 7.5 M{sub sun} yr{sup -1}, similar to that expected for non-interacting galaxies with stellar mass comparable to the SQ galaxies. Although star formation in SQ is mainly occurring at, or external to the periphery of the galaxies, the relation of SFR per unit physical area to gas column density for the brightest sources is similar to that seen for star formation regions in galactic disks. We also show that available sources of dust in the group halo can provide enough dust to produce up to L{sub IR} {approx} 10{sup 42} erg s{sup -1} powered by collisional heating. Though a minority of the total infrared emission (which we infer to trace distributed star-formation), this is several times higher than the X-ray luminosity of the halo, so could indicate an important cooling mechanism for the hot intergalactic medium (IGM) and account for the overall correspondence between FIR and X-ray emission. We investigate two potential modes of star formation in SQ consistent with the data, fueled either by gas from a virialized hot IGM continuously accreting onto the group, whose cooling is enhanced by grains injected from an in situ population of intermediate mass stars, or by interstellar gas stripped from the galaxies. The former mode offers a natural explanation for the observed baryon deficiency in the IGM of SQ as well as for the steep L{sub X}-T{sub X} relation of groups such as SQ with lower velocity dispersions.

Natale, G.; Tuffs, R. J. [Max Planck Institute fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Xu, C. K.; Lu, N. [Infrared Processing and Analysis Center, California Institute of Technology 100-22, Pasadena, CA 91125 (United States); Popescu, C. C. [University of Central Lancashire, Preston, PR1 2HE (United Kingdom); Fischera, J. [Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 Saint George Street, Toronto, ON, M5S 3H8 (Canada); Lisenfeld, U. [Department de Fisica Teorica y del Cosmos, Universidad de Granada, Granada (Spain); Appleton, P. [NASA Herschel Science Center, IPAC, California Institute of Technology, Pasadena, CA 91125 (United States); Dopita, M. [Research School of Astronomy and Astrophysics, The Australian National University, Cotter Road, Weston Creek, ACT 2611 (Australia); Duc, P.-A. [Laboratoire AIM, CEA/DSM-CNRS-Universite Paris Diderot, Dapnia/Service d'Astrophysique, CEA-Saclay, 91191 Gif-sur-Yvette Cedex (France); Gao, Y. [Purple Mountain Observatory, Chinese Academy of Sciences, 2 West Beijing Road, Nanjing 210008 (China); Reach, W. [Spitzer Science Center, IPAC, California Institute of Technology, Pasadena, CA 91125 (United States); Sulentic, J. [Instituto de Astrofisica de AndalucIa, CSIC, Apdo. 3004, 18080, Granada (Spain); Yun, M., E-mail: giovanni.natale@mpi-hd.mpg.d, E-mail: richard.buffs@mpi-hd.mpg.d [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States)

2010-12-10T23:59:59.000Z

19

Risk assessment for the Waste Technologies Industries (WTI) Hazardous Waste Incineration Facility (East Liverpool, Ohio). Volume 3. Characterization of the nature and magnitude of emissions  

SciTech Connect (OSTI)

Contents: Introduction; Data Used in Characterizing Emissions; Incinerator Stack Emissions; Fugitive Emissions; Uncertainty in Emissions Characterization; and References.

NONE

1997-05-01T23:59:59.000Z

20

PROPERTIES AND SPATIAL DISTRIBUTION OF DUST EMISSION IN THE CRAB NEBULA  

SciTech Connect (OSTI)

Recent infrared (IR) observations of freshly formed dust in supernova remnants have yielded significantly lower dust masses than predicted by theoretical models and measured from high-redshift observations. The Crab Nebula's pulsar wind is thought to be sweeping up freshly formed supernova (SN) dust along with the ejected gas. The evidence for this dust was found in the form of an IR excess in the integrated spectrum of the Crab and in extinction against the synchrotron nebula that revealed the presence of dust in the filament cores. We present the first spatially resolved emission spectra of dust in the Crab Nebula acquired with the Infrared Spectrograph on board the Spitzer Space Telescope. The IR spectra are dominated by synchrotron emission and show forbidden line emission from S, Si, Ne, Ar, O, Fe, and Ni. We derived a synchrotron spectral map from the 3.6 and 4.5 {mu}m images, and subtracted this contribution from our data to produce a map of the residual continuum emission from dust. The dust emission appears to be concentrated along the ejecta filaments and is well described by an amorphous carbon or silicate grain compositions. We find a dust temperature of 55 {+-} 4 K for silicates and 60 {+-} 7 K for carbon grains. The total estimated dust mass is (1.2-12) Multiplication-Sign 10{sup -3} M{sub Sun }, well below the theoretical dust yield predicted for a core-collapse supernova. Our grain heating model implies that the dust grain radii are relatively small, unlike what is expected for dust grains formed in a Type IIP SN.

Temim, Tea; Sonneborn, George; Dwek, Eli; Arendt, Richard G. [Observational Cosmology Lab, Code 665, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Gehrz, Robert D. [Minnesota Institute for Astrophysics, University of Minnesota, 116 Church Street SE, Minneapolis, MN 55455 (United States); Slane, Patrick [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Roellig, Thomas L., E-mail: tea.temim@nasa.gov [NASA Ames Research Center, MS 245-6, Moffett Field, CA 94035-1000 (United States)

2012-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "fugitive dust emissions" 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

Emissions Trading and Air Toxics Emissions: RECLAIM and Toxics Regulation in the South Coast Air Basin  

E-Print Network [OSTI]

fugitive emissions in an emissions trading program, as theexists between an emissions trading program that allows aircreation of other ROC emissions trading programs. JOURNAL OF

Cohen, Nancy J.

1993-01-01T23:59:59.000Z

22

E-Print Network 3.0 - astrophysical dust emission Sample Search...  

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

was optically thin and had constant emissivity; that is, the cone of dust'' has been... inclination binaries such as WR 140, arcs of ... Source: Monnier, John D. - Department of...

23

THE SPATIAL DISTRIBUTION OF DUST AND STELLAR EMISSION OF THE MAGELLANIC CLOUDS  

SciTech Connect (OSTI)

We study the emission by dust and stars in the Large and Small Magellanic Clouds, a pair of low-metallicity nearby galaxies, as traced by their spatially resolved spectral energy distributions. This project combines Herschel Space Observatory PACS and SPIRE far-infrared photometry with other data at infrared and optical wavelengths (the data were obtained as part of the HERschel Inventory of The Agents of Galaxy Evolution survey; PI: M. Meixner). We build maps of dust, stellar luminosity, and mass of both Magellanic Clouds, and analyze the spatial distribution of dust/stellar luminosity and mass ratios. These ratios vary considerably throughout the galaxies, generally between the range 0.01 {<=} L{sub dust}/L{sub *} {<=} 0.6 and 10{sup -4} {<=} M{sub dust}/M{sub *} {<=} 4 Multiplication-Sign 10{sup -3}. We observe that the dust/stellar ratios depend on the interstellar medium environment, such as the distance from currently or previously star-forming regions, and on the intensity of the interstellar radiation field. In addition, we construct star formation rate (SFR) maps, and find that the SFR is correlated with the dust/stellar luminosity and dust temperature in both galaxies, demonstrating the relation between star formation, dust emission, and heating, though these correlations exhibit substantial scatter.

Skibba, Ramin A.; Engelbracht, Charles W.; Misselt, Karl; Montiel, Edward [Steward Observatory, University of Arizona, 933 N. Cherry Avenue, Tucson, AZ 85721 (United States); Aniano, Gonzalo [Princeton University Observatory, Peyton Hall, Princeton, NJ 08544 (United States); Babler, Brian [Department of Astronomy, 475 North Charter St., University of Wisconsin, Madison, WI 53706 (United States); Bernard, Jean-Philippe [Universite de Toulouse, UPS-OMP, IRAP, Toulouse (France); Bot, Caroline [Universite de Strasbourg, Observatoire Astronomique de Strasbourg, F-67000 Strasbourg (France); Carlson, Lynn Redding; Israel, Frank [Sterrewacht Leiden, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands); Galametz, Maud [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Galliano, Frederic; Hony, Sacha; Lebouteiller, Vianney; Madden, Suzanne; Okumura, Koryo; Panuzzo, Pasquale [AIM, CEA/Saclay, L'Orme des Merisiers, 91191 Gif-sur-Yvette (France); Gordon, Karl; Meixner, Margaret [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Li, Aigen, E-mail: rskibba@ucsd.edu [314 Physics Building, Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211 (United States); and others

2012-12-10T23:59:59.000Z

24

DUST EMISSION FROM EVOLVED AND UNEVOLVED H II REGIONS IN THE LARGE MAGELLANIC CLOUD  

SciTech Connect (OSTI)

We present a study of the dust properties of 12 classical and superbubble H II regions in the Large Magellanic Cloud. We use infrared photometry from Spitzer (8, 24, 70, and 160 {mu} m bands), obtained as part of the Surveying the Agents of a Galaxy's Evolution (SAGE) program, along with archival spectroscopic classifications of the ionizing stars to examine the role of stellar sources on dust heating and processing. Our infrared observations show surprisingly little correlation between the emission properties of the dust and the effective temperatures or bolometric magnitudes of stars in the H II regions, suggesting that the H II region evolutionary timescale is not on the order of the dust processing timescale. We find that the infrared emission of superbubbles and classical H II regions shows little differentiation between the two classes, despite the significant differences in age and morphology. We do detect a correlation of the 24 {mu} m emission from hot dust with the ratio of 70-160 {mu} m flux. This correlation can be modeled as a trend in the temperature of a minority hot dust component, while a majority of the dust remains significantly cooler.

Slater, C. T.; Oey, M. S. [Astronomy Department, University of Michigan, Ann Arbor, MI 48109 (United States); Li, A. [Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211 (United States); Bernard, J.-Ph.; Paradis, D. [Universit de Toulouse, UPS-OMP, IRAP, Toulouse (France); Churchwell, E. [Department of Astronomy, University of Wisconsin-Madison, 475 North Charter Street, Madison, WI 53706 (United States); Gordon, K. D.; Lawton, B.; Meixner, M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Indebetouw, R. [Department of Astronomy, University of Virginia, P.O. Box 3818, Charlottesville, VA 22903 (United States); Reach, W.T. [Universities Space Research Association, Stratospheric Observatory for Infrared Astronomy, NASA Ames Research Center, MS 211-3, Moffett Field, CA 94035 (United States)

2011-05-10T23:59:59.000Z

25

Molecular Hydrogen Emission from Protoplanetary Disks II. Effects of X-ray Irradiation and Dust Evolution  

E-Print Network [OSTI]

Detailed models for the density and temperature profiles of gas and dust in protoplanetary disks are constructed by taking into account X-ray and ultraviolet (UV) irradiation from a central T Tauri star, as well as dust size growth and settling toward the disk midplane. The spatial and size distributions of dust grains in the disks are numerically computed by solving the coagulation equation for settling dust particles. The level populations and line emission of molecular hydrogen are calculated using the derived physical structure of the disks. X-ray irradiation is the dominant heating source of the gas in the inner disk region and in the surface layer, while the far UV heating dominates otherwise. If the central star has strong X-ray and weak UV radiation, the H2 level populations are controlled by X-ray pumping, and the X-ray induced transition lines could be observable. If the UV irradiation is strong, the level populations are controlled by thermal collisions or UV pumping, depending on the properties of the dust grains in the disks. As the dust particles evolve in the disks, the gas temperature at the disk surface drops because the grain photoelectric heating becomes less efficient, while the UV radiation fields become stronger due to the decrease of grain opacity. This makes the H2 level populations change from local thermodynamic equilibrium (LTE) to non-LTE distributions, which results in changes to the line ratios of H2 emission. Our results suggest that dust evolution in protoplanetary disks could be observable through the H2 line ratios. The emission lines are strong from disks irradiated by strong UV and X-rays and possessing small dust grains; such disks will be good targets in which to observe H2 emission.

H. Nomura; Y. Aikawa; M. Tsujimoto; Y. Nakagawa; T. J. Millar

2007-02-01T23:59:59.000Z

26

Radionuclide Air Emission Report for 2011  

E-Print Network [OSTI]

LBNL-470E-20Ì1 Radionuclide Air Emission Report for Preparedfor Estimating Fugitive Air Emissions of Radionuclides fromStandards for Hazardous Air Pollutants (Radionuclides),

Wahl, Linnea

2012-01-01T23:59:59.000Z

27

Soil organic carbon enrichment of dust emissions: magnitude, mechanisms and its implications for  

E-Print Network [OSTI]

Soil organic carbon enrichment of dust emissions: magnitude, mechanisms and its implications Range, MSC 3 JER, NMSU, Box 30003, Las Cruces, NM 88003-8003, USA. E-mail: nwebb@nmsu.edu ABSTRACT: Soil to the role of aeolian processes in influencing soil organic carbon (SOC) flux and the release of greenhouse

28

Emission Factor for Antimony in Brake Abrasion Dusts as One of the  

E-Print Network [OSTI]

originating from automobiles. Abrasion dusts from commercially available brake pads (nonasbestos organic type factors originating from automobiles were approximately 32 µg Sb/braking/car for PM10 and 22 µg Sb of automobiles to the atmospheric Sb concen- tration. The emission factors of pollutants from automobiles have

Short, Daniel

29

DUST AROUND R CORONAE BOREALIS STARS. II. INFRARED EMISSION FEATURES IN AN H-POOR ENVIRONMENT  

SciTech Connect (OSTI)

Residual Spitzer/Infrared Spectrograph spectra for a sample of 31 R Coronae Borealis (RCB) stars are presented and discussed in terms of narrow emission features superimposed on the quasi-blackbody continuous infrared emission. A broad {approx}6-10 {mu}m dust emission complex is seen in the RCBs showing an extreme H-deficiency. A secondary and much weaker {approx}11.5-15 {mu}m broad emission feature is detected in a few RCBs with the strongest {approx}6-10 {mu}m dust complex. The Spitzer infrared spectra reveal for the first time the structure within the {approx}6-10 {mu}m dust complex, showing the presence of strong C-C stretching modes at {approx}6.3 and 8.1 {mu}m as well as of other dust features at {approx}5.9, 6.9, and 7.3 {mu}m, which are attributable to amorphous carbonaceous solids with little or no hydrogen. The few RCBs with only moderate H-deficiencies display the classical ''unidentified infrared bands (UIRs)'' and mid-infrared features from fullerene-related molecules. In general, the characteristics of the RCB infrared emission features are not correlated with the stellar and circumstellar properties, suggesting that the RCB dust features may not be dependent on the present physical conditions around RCB stars. The only exception seems to be the central wavelength of the 6.3 {mu}m feature, which is blueshifted in those RCBs showing also the UIRs, i.e., the RCBs with the smallest H deficiency.

Garcia-Hernandez, D. A. [Instituto de Astrofisica de Canarias, C/Via Lactea s/n, E-38200 La Laguna (Spain); Rao, N. Kameswara [543, 17th Main, IV Sector, HSR Layout, Bangalore 560102 and Indian Institute of Astrophysics, Bangalore 560034 (India); Lambert, D. L., E-mail: agarcia@iac.es, E-mail: nkrao@iiap.res.in, E-mail: dll@astro.as.utexas.edu [W. J. McDonald Observatory, University of Texas at Austin, 1 University Station, C1400, Austin, TX 78712-0259 (United States)

2013-08-20T23:59:59.000Z

30

Thermal Dust Emission from Proplyds, Unresolved Disks, and Shocks in the Orion Nebula  

E-Print Network [OSTI]

We present a new 11.7 micron mosaic image of the Orion nebula obtained with T-ReCS on Gemini South. The map includes the BN/KL region, the Trapezium, and OMC-1 South. Excluding BN/KL, we detect 91 point sources, with 27 known proplyds and over 30 ``naked'' stars showing no extended structure in HST images. Within the region we surveyed, 80 percent of known proplyds show detectable emission, almost 40 percent of naked stars are detected at 11.7 micron, and the fraction of all visible sources with IR excess emission is roughly 50 percent. Thermal dust emission from stars with no extended structure in HST images means that they have dust disks comparable to the size of our solar system. Proplyds and stars with IR excess show a clear anti-correlation in their spatial distribution, with proplyds clustered close to theta1C, and other infrared sources found farther away. We suspect that the clustered proplyds trace the youngest 0.5 Myr age group associated with the Trapezium, while the more uniformly-distributed sources trace the older 1-2 Myr population of the ONC. This suggests that small disks persist for a few Myr in irradiated environments, and hints that hierarchical sub-clustering has been important. Within 30 arcsec of theta1C, all proplyds are detected at 11.7 micron. The star theta1D is associated with the most prominent mid-IR dust arc in the nebula. We propose that this arc is the consequence of theta1D being the closest member of the Trapezium to the background cloud. Finally, we detect dust emission from HH jets in Orion, including HH202, HH529, HH513, and HH514. This is the first detection of mid-IR continuum emission from dust in the body of a collimated HH jet or bow shock.

Nathan Smith; John Bally; Ralph Y. Shuping; Mark Morris; Marc Kassis

2005-06-20T23:59:59.000Z

31

Haul road dust control  

SciTech Connect (OSTI)

A field study was conducted to measure dust from haul trucks at a limestone quarry and a coal preparation plant waste hauling operation. The study found that primarily wind, distance and road treatment conditions notably affected the dust concentrations at locations next to, 50 ft from, and 100 ft away from the unpaved haulage road. Airborne dust measured along the unpaved haul road showed that high concentrations of fugitive dust can be generated with these concentrations rapidly decreasing to nearly background levels within 100 ft of the road. Instantaneous respirable dust measurements illustrated that the trucks generate a real-time dust cloud that has a peak concentration with a time-related decay rate as the dust moves past the sampling locations. The respirable dust concentrations and peak levels were notably diminished as the dust cloud was transported, diluted, and diffused by the wind over the 100 ft distance from the road. Individual truck concentrations and peak levels measured next to the dry road surface test section were quite variable and dependent on wind conditions, particularly wind direction, with respect to reaching the sampling location. The vast majority of the fugitive airborne dust generated from unpaved and untreated haulage roads was non-respirable. 6 figs.

Reed, W.R.; Organiscak, J.A. [NIOSH-PRL, Pittsburgh, PA (United States)

2007-10-15T23:59:59.000Z

32

Adaptive Optics Nulling Interferometric Constraints on the Mid-Infrared Exozodiacal Dust Emission around Vega  

E-Print Network [OSTI]

We present the results of mid-infrared nulling interferometric observations of the main-sequence star alpha Lyr (Vega) using the 6.5 m MMT with its adaptive secondary mirror. From the observations at 10.6 microns, we find that there is no resolved emission from the circumstellar environment (at separations greater than 0.8 AU) above 2.1% (3 sigma limit) of the level of the stellar photospheric emission. Thus, we are able to place an upper limit on the density of dust in the inner system of 650 times that of our own solar system's zodiacal cloud. This limit is roughly 2.8 times better than those determined with photometric excess observations such as those by IRAS. Comparison with far-infrared observations by IRAS shows that the density of warm dust in the inner system ( 80%) of the material in the outer system is ice.

Liu, W M; Hoffmann, W F; Brusa, G; Wildi, F; Miller, D; Lloyd-Hart, M; Kenworthy, M A; McGuire, P C; Angel, J R P

2004-01-01T23:59:59.000Z

33

Adaptive Optics Nulling Interferometric Constraints on the Mid-Infrared Exozodiacal Dust Emission around Vega  

E-Print Network [OSTI]

We present the results of mid-infrared nulling interferometric observations of the main-sequence star alpha Lyr (Vega) using the 6.5 m MMT with its adaptive secondary mirror. From the observations at 10.6 microns, we find that there is no resolved emission from the circumstellar environment (at separations greater than 0.8 AU) above 2.1% (3 sigma limit) of the level of the stellar photospheric emission. Thus, we are able to place an upper limit on the density of dust in the inner system of 650 times that of our own solar system's zodiacal cloud. This limit is roughly 2.8 times better than those determined with photometric excess observations such as those by IRAS. Comparison with far-infrared observations by IRAS shows that the density of warm dust in the inner system ( 80%) of the material in the outer system is ice.

W. M. Liu; P. M. Hinz; W. F. Hoffmann; G. Brusa; F. Wildi; D. Miller; M. Lloyd-Hart; M. A. Kenworthy; P. C. McGuire; J. R. P. Angel

2004-06-25T23:59:59.000Z

34

On the Anomalous Silicate Emission Features of AGNs: A Possible Interpretation Based on Porous Dust  

E-Print Network [OSTI]

The recent Spitzer detections of the 9.7 micron Si--O silicate emission in type 1 AGNs provide support for the AGN unification scheme. The properties of the silicate dust are of key importance to understanding the physical, chemical and evolutionary properties of the obscuring dusty torus around AGNs. Compared to that of the Galactic interstellar medium (ISM), the 10 micron silicate emission profile of type 1 AGNs is broadened and has a clear shift of peak position to longer wavelengths. In literature this is generally interpreted as an indication of the deviations of the silicate composition, size, and degree of crystallization of AGNs from that of the Galactic ISM. In this Letter we show that the observed peak shift and profile broadening of the 9.7 micron silicate emission feature can be explained in terms of porous composite dust consisting of ordinary interstellar amorphous silicate, amorphous carbon and vacuum. Porous dust is naturally expected in the dense circumnuclear region around AGNs, as a consequence of grain coagulation.

M. P. Li; Q. J. Shi; Aigen Li

2008-08-29T23:59:59.000Z

35

Molecular Hydrogen Emission from Protoplanetary Disks II. Effects of X-ray Irradiation and Dust Evolution  

E-Print Network [OSTI]

Detailed models for the density and temperature profiles of gas and dust in protoplanetary disks are constructed by taking into account X-ray and ultraviolet (UV) irradiation from a central T Tauri star, as well as dust size growth and settling toward the disk midplane. The spatial and size distributions of dust grains in the disks are numerically computed by solving the coagulation equation for settling dust particles. The level populations and line emission of molecular hydrogen are calculated using the derived physical structure of the disks. X-ray irradiation is the dominant heating source of the gas in the inner disk region and in the surface layer, while the far UV heating dominates otherwise. If the central star has strong X-ray and weak UV radiation, the H2 level populations are controlled by X-ray pumping, and the X-ray induced transition lines could be observable. If the UV irradiation is strong, the level populations are controlled by thermal collisions or UV pumping, depending on the properties of...

Nomura, H; Tsujimoto, M; Nakagawa, Y; Millar, T J

2007-01-01T23:59:59.000Z

36

Quantifying the Heating Sources for Mid-infrared Dust Emissions in Galaxies: The Case of M 81  

E-Print Network [OSTI]

With the newly available SPIRE images at 250 and 500 micron from Herschel Space Observatory, we study quantitative correlations over a sub-kpc scale among three distinct emission components in the interstellar medium of the nearby spiral galaxy M 81 (NGC 3031): (a) $I_{8}$ or $I_{24}$, the surface brightness of the mid-infrared emission observed in the Spitzer IRAC 8 or MIPS 24 micron band, with $I_8$ and $I_{24}$ being dominated by the emissions from Polycyclic Aromatic Hydrocarbons (PAHs) and very small grains (VSGs) of dust, respectively; (b) $I_{500}$, that of the cold dust continuum emission in the Herschel SPIRE 500 micron band, dominated by the emission from large dust grains heated by evolved stars, and (c) $I_{{\\rm H}\\alpha}$, a nominal surface brightness of the H$\\alpha$ line emission, from gas ionized by newly formed massive stars. The results from our correlation study, free from any assumption on or modeling of dust emissivity law or dust temperatures, present solid evidence for significant heati...

Lu, Nanyao; Boselli, A; Baes, M; Wu., H; Madden, S C; De Looze, I; Rémy-Ruyer, A; Boquien, M; Wilson, C D; Galametz, M; Lam, M I; Cooray, A; Spinoglio, L; Zhao, Y

2014-01-01T23:59:59.000Z

37

Microwave Emission by Dust: Mechanisms, Properties and Prospects for ISM Studies  

E-Print Network [OSTI]

I review my work with Bruce Draine on dust emissivity at microwave frequencies (3 cm - 3 mm). This emissivity explains the recently detected "anomalous" component of the galactic foreground emission. Both small (a<0.001 micron) and large grains contribute to this emission. Small grains have electric dipole moments and emit while they rotate; the microwave emission of large grains is mostly due to magneto-dipole radiation. Most efficient magneto-dipole emitters are strongly magnetic, e.g. ferrimagnetic or ferromagnetic, materials. The relative role of the two mechanisms can be established through observations of microwave emissivity from dark clouds. New microwave window is a window of opportunity for interstellar studies. Magnetic fields inside dark clouds may be successfully studied via microwave polarization. Microwave emissivity constrains the abundance of strongly magnetic materials. For instance, the available data at 90 GHz indicate that not more than 5% of interstellar Fe is in the form of metallic iron grains or inclusions (e.g., in ``GEMS''). Future missions, e.g. MAP and PLANCK, will bring a wealth of microwave data that can be successfully used to study ISM. Such a study would be appreciated by cosmologists who franticly try to remove all foregrounds from their data.

Lazarian A

1998-11-03T23:59:59.000Z

38

Air Pollution Control Regulations: No. 5 - Fugitive Dust (Rhode Island) |  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarly Career Scientists' ResearchThe OfficeUtility Fed. Government CommercialProgram and AllowanceDepartment

39

Probing the mass loss history of carbon stars using CO line and dust continuum emission  

E-Print Network [OSTI]

An extensive modelling of CO line emission from the circumstellar envelopes around a number of carbon stars is performed. By combining radio observations and infrared observations obtained by ISO the circumstellar envelope characteristics are probed over a large radial range. In the radiative transfer analysis the observational data are consistently reproduced assuming a spherically symmetric and smooth wind expanding at a constant velocity. The combined data set gives better determined envelope parameters, and puts constraints on the mass loss history of these carbon stars. The importance of dust in the excitation of CO is addressed using a radiative transfer analysis of the observed continuum emission, and it is found to have only minor effects on the derived line intensities. The analysis of the dust emission also puts further constraints on the mass loss rate history. The stars presented here are not likely to have experienced any drastic long-term mass loss rate modulations, at least less than a factor of about 5, over the past thousands of years. Only three, out of nine, carbon stars were observed long enough by ISO to allow a detection of CO far-infrared rotational lines.

F. L. Schoeier; N. Ryde; H. Olofsson

2002-06-05T23:59:59.000Z

40

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

E-Print Network [OSTI]

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

B. T. Draine; Aigen Li

2000-11-16T23:59:59.000Z

Note: This page contains sample records for the topic "fugitive dust emissions" 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

Predicting the stellar and non-equilibrium dust emission spectra of high-resolution simulated galaxies with DART-Ray  

E-Print Network [OSTI]

We describe the calculation of the stochastically heated dust emission using the 3D ray-tracing dust radiative transfer code DART-Ray, which is designed to solve the dust radiative transfer problem for galaxies with arbitrary geometries. In order to reduce the time required to derive the non-equilibrium dust emission spectra from each volume element within a model, we implemented an adaptive SED library approach, which we tested for the case of axisymmetric galaxy geometries. To show the capabilities of the code, we applied DART-Ray to a high-resolution N-body+SPH galaxy simulation to predict the appearance of the simulated galaxy at a set of wavelengths from the UV to the sub-mm. We analyse the results to determine the effect of dust on the observed radial and vertical profiles of the stellar emission as well as on the attenuation and scattering of light from the constituent stellar populations. We also quantify the proportion of dust re-radiated stellar light powered by young and old stellar populations, bo...

Natale, Giovanni; Tuffs, Richard J; Debattista, Victor P; Fischera, Jörg; Grootes, Meiert W

2015-01-01T23:59:59.000Z

42

ANOMALOUS SILICATE DUST EMISSION IN THE TYPE 1 LINER NUCLEUS OF M81  

SciTech Connect (OSTI)

We report the detection and successful modeling of the unusual 9.7 {mu}m Si-O stretching silicate emission feature in the type 1 (i.e., face-on) LINER nucleus of M81. Using the Infrared Spectrograph (IRS) instrument on Spitzer, we determine the feature in the central 230 pc of M81 to be in strong emission, with a peak at {approx}10.5 {mu}m. This feature is strikingly different in character from the absorption feature of the galactic interstellar medium, and from the silicate absorption or weak emission features typical of galaxies with active star formation. We successfully model the high signal-to-noise ratio IRS spectra with porous silicate dust using laboratory-acquired mineral spectra. We find that the most probable fit uses micron-sized, porous grains of amorphous silicate and amorphous carbon. In addition to silicate dust, there is weak polycyclic aromatic hydrocarbon (PAH) emission present (particularly at 11.3 {mu}m, arising from the C-H out-of-plane bending vibration of relatively large PAHs of {approx}500-1000 C atoms) whose character reflects the low-excitation active galactic nucleus environment, with some evidence that small PAHs of {approx}100-200 C atoms (responsible for the 7.7 {mu}m C-C stretching band) in the immediate vicinity of the nucleus have been preferentially destroyed. Analysis of the infrared fine structure lines confirms the LINER character of the M81 nucleus. Four of the infrared H{sub 2} rotational lines are detected and fit to an excitation temperature of T {approx} 800 K. Spectral maps of the central 230 pc in the [Ne II] 12.8 {mu}m line, the H{sub 2} 17 {mu}m line, and the 11.3 {mu}m PAH C-H bending feature reveal arc- or spiral-like structures extending from the core. We also report on epochal photometric and spectroscopic observations of M81, whose nuclear intensity varies in time across the spectrum due to what is thought to be inefficient, sub-Eddington accretion onto its central black hole. We find that, contrary to the implications of earlier photometry, the nucleus has not varied over a period of two years at these infrared wavelengths to a precision of about 1%.

Smith, Howard A.; Ashby, M. L. N.; Fazio, G. G.; Huang, J.-S.; Marengo, M.; Wang, Z.; Willner, S.; Zezas, A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Li, Aigen; Li, M. P.; Koehler, M. [Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211 (United States); Spinoglio, L. [Istituto di Fisica dello Spazio Interplanetario, CNR, via Fosso del Cavaliere, 100, I-00133 Rome (Italy); Wu, Y. L., E-mail: hsmith@cfa.harvard.ed, E-mail: lia@missouri.ed [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91101 (United States)

2010-06-10T23:59:59.000Z

43

Observed relationship between CO2-1 and dust emission during post-AGB phase  

E-Print Network [OSTI]

A CO\\,2-1 line survey is performed toward a sample of 58 high Galactic latitude post-AGB (pAGB) stars. To complement the observations, a compilation of literature CO\\,2-1 line data of known pAGB stars is done. After combining the datasets, CO\\,2-1 line data are available for 133 pAGB stars (about 34 per cent of known pAGB stars) among which 44 are detections. The CO line strengths are compared with infrared dust emission for these pAGB stars by defining a ratio between the integrated CO\\,2-1 line flux and {\\it IRAS} 25\\,mu flux density (CO-IR ratio). The relationship between the CO-IR ratio and the {\\it IRAS} color C23 (defined with the 25 and 60\\,mu flux densities) is called here the CO-IR diagram. The pAGB objects are found to be located between AGB stars and planetary nebulae (PNe), and segregate into three distinctive groups (I, II and III) on the CO-IR diagram. By analyzing their various properties such as chemical types, spectral types, binarity, circumstellar envelope expansion velocities, and pAGB sub...

He, J H; Hasegawa, T I; Schmidt, M R

2013-01-01T23:59:59.000Z

44

A BAYESIAN METHOD FOR THE ANALYSIS OF THE DUST EMISSION IN THE FAR-INFRARED AND SUBMILLIMETER  

SciTech Connect (OSTI)

We present a method, based on Bayesian statistics, to fit the dust emission parameters in the far-infrared and submillimeter wavelengths. The method estimates the dust temperature and spectral emissivity index, plus their relationship, properly taking into account the statistical and systematic uncertainties. We test it on three sets of simulated sources detectable by the Herschel Space Observatory in the PACS and SPIRE spectral bands (70-500 {mu}m), spanning over a wide range of dust temperatures. The simulated observations are a one-component interstellar medium and two two-component sources, both warm (H II regions) and cold (cold clumps (CCs)). We first define a procedure to identify the better model, then we recover the parameters of the model and measure their physical correlations by means of a Markov Chain Monte Carlo algorithm adopting multi-variate Gaussian priors. In this process, we assess the reliability of the model recovery and of parameter estimation. We conclude that the model and parameters are properly recovered only under certain circumstances and that false models may be derived in some cases. We applied the method to a set of 91 starless CCs in an interarm region of the Galactic plane with low star formation activity, observed by Herschel in the Hi-GAL survey. Our results are consistent with a temperature-independent spectral index.

Veneziani, M.; Noriega-Crespo, A.; Carey, S.; Paladini, R. [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Piacentini, F. [Dipartimento di Fisica, Universita di Roma ''La Sapienza'', I-00185 Rome (Italy); Paradis, D., E-mail: marcella.veneziani@ipac.caltech.edu [Universite de Toulouse, UPS-OMP, IRAP, F-31062 Toulouse (France)

2013-07-20T23:59:59.000Z

45

T E C H N I C A L A D V A N C E Soil organic carbon dust emission: an omitted global  

E-Print Network [OSTI]

T E C H N I C A L A D V A N C E Soil organic carbon dust emission: an omitted global source emission, soil organic carbon Received 16 April 2013 and accepted 21 May 2013 Introduction Uncertainty, Gunnedah, NSW 2380, Australia Abstract Soil erosion redistributes soil organic carbon (SOC) within

46

First Detection of UV emission from a Detached Dust Shell: GALEX Observations of the Carbon AGB Star U Hya  

E-Print Network [OSTI]

We present the discovery of an extended ring of ultraviolet emission surrounding the AGB star U Hya in archival observations performed by the Galaxy Evolution Explorer (GALEX). This is the third discovery of extended UV emission from a carbon AGB star and the first from an AGB star with a detached shell. From imaging and photometric analysis of the FUV and NUV images, we determined that the ultraviolet ring has a radius of $\\sim 110^{\\prime\\prime}$, thus indicating that the emitting material is likely associated with the detached shell seen in the infrared. We find that scattering of the central point source of NUV and FUV emission by the dust shell is negligible. Moreover, we find that scattering of the interstellar radiation field by the dust shell can contribute at most $\\sim10%$ of the FUV flux. Morphological and photometric evidence suggests that shocks caused by the star's motion through space and, possibly, shock-excited H$_2$ molecules are the most likely origins of the UV flux. In contrast to previou...

Sanchez, E; Ramstedt, S; Stassun, K G

2014-01-01T23:59:59.000Z

47

Near-IR dust and line emission from the central region of Mrk1066: Constraints from Gemini NIFS  

E-Print Network [OSTI]

We present integral field spectroscopy of the inner 350 pc of the Mrk1066 obtained with Gemini NIFS at a spatial resolution of 35 pc. This high spatial resolution allowed us to observe, for the first time in this galaxy, an unresolved dust concentration with mass 0.014 M_Sun, which may be part of the dusty torus. The emission-line fluxes are elongated in PA=135/315deg in agreement with the [OIII] and radio images and, except for the H lines, are brighter to the north-west than to the south-east. The H emission is stronger to the south-east, where we find a large region of star-formation. The strong correlation between the radio emission and the highest emission-line fluxes indicates that the radio jet plays a fundamental role at these intensity levels. The H2 flux is more uniformly distributed and has an excitation temperature of 2100 K. Its origin appears to be circumnuclear gas heated by X-rays from the AGN. The [FeII] emission also is consistent with X-ray heating, but with additional emission due to excit...

Riffel, Rogemar A; Nagar, Neil M

2010-01-01T23:59:59.000Z

48

Engineering analysis of fugitive particulate matter emissions from cattle feedyards  

E-Print Network [OSTI]

with designated symbols ........................................................................................10 Figure 2 Illustration of the ISCST3 layout of the feedyard with the various sources indicated...............................................................................................20 Figure 3 July 2003 average TSP concentration measurements from the 10 m tower designated by a data point for each test period....................................30 Figure 4 Hourly concentrations measured by the TEOM located at the North...

Hamm, Lee Bradford

2006-04-12T23:59:59.000Z

49

LATE-TIME DUST EMISSION FROM THE TYPE IIn SUPERNOVA 1995N  

SciTech Connect (OSTI)

Type IIn supernovae (SNe IIn) have been found to be associated with significant amounts of dust. These core-collapse events are generally expected to be the final stage in the evolution of highly massive stars, either while in an extreme red supergiant phase or during a luminous blue variable phase. Both evolutionary scenarios involve substantial pre-supernova mass loss. I have analyzed the SN IIn 1995N in MCG -02-38-017 (Arp 261), for which mid-infrared archival data obtained with the Spitzer Space Telescope in 2009 ({approx}14.7 yr after explosion) and with the Wide-field Infrared Survey Explorer in 2010 ({approx}15.6-16.0 yr after explosion) reveal a luminous ({approx}2 Multiplication-Sign 10{sup 7} L{sub Sun }) source detected from 3.4 to 24 {mu}m. These observations probe the circumstellar material, set up by pre-SN mass loss, around the progenitor star and indicate the presence of {approx}0.05-0.12 M{sub Sun} of pre-existing, cool dust at {approx}240 K. This is at least a factor {approx}10 lower than the dust mass required to be produced from SNe at high redshift, but the case of SN 1995N lends further evidence that highly massive stars could themselves be important sources of dust.

Van Dyk, Schuyler D., E-mail: vandyk@ipac.caltech.edu [Spitzer Science Center/Caltech, Mailcode 220-6, Pasadena, CA 91125 (United States)

2013-05-15T23:59:59.000Z

50

AIR QUALITY: ODOR, DUST, AND GASEOUS EMISSIONS FROM CONCENTRATED FEEDING OPERATIONS IN THE SOUTHERN GREAT PLAINS  

E-Print Network [OSTI]

dramatically during drought periods, whereas, odor concerns increase with wet weather. Ammonia, hydrogen standards are imposed. The Texas Agricultural Experiment Station, West Texas A&M University, Texas; determine dust generation vs. simulated cattle hoof kinetics; determine effects of surface manure

Mukhtar, Saqib

51

Dust Measurements in Tokamaks  

SciTech Connect (OSTI)

Dust production and accumulation impose safety and operational concerns for ITER. Diagnostics to monitor dust levels in the plasma as well as in-vessel dust inventory are currently being tested in a few tokamaks. Dust accumulation in ITER is likely to occur in hidden areas, e.g. between tiles and under divertor baffles. A novel electrostatic dust detector for monitoring dust in these regions has been developed and tested at PPPL. In DIII-D tokamak dust diagnostics include Mie scattering from Nd:YAG lasers, visible imaging, and spectroscopy. Laser scattering resolves size of particles between 0.16-1.6 {micro}m in diameter; the total dust content in the edge plasmas and trends in the dust production rates within this size range have been established. Individual dust particles are observed by visible imaging using fast-framing cameras, detecting dust particles of a few microns in diameter and larger. Dust velocities and trajectories can be determined in 2D with a single camera or 3D using multiple cameras, but determination of particle size is problematic. In order to calibrate diagnostics and benchmark dust dynamics modeling, pre-characterized carbon dust has been injected into the lower divertor of DIII-D. Injected dust is seen by cameras, and spectroscopic diagnostics observe an increase of carbon atomic, C2 dimer, and thermal continuum emissions from the injected dust. The latter observation can be used in the design of novel dust survey diagnostics.

Rudakov, D; Yu, J; Boedo, J; Hollmann, E; Krasheninnikov, S; Moyer, R; Muller, S; Yu, A; Rosenberg, M; Smirnov, R; West, W; Boivin, R; Bray, B; Brooks, N; Hyatt, A; Wong, C; Fenstermacher, M; Groth, M; Lasnier, C; McLean, A; Stangeby, P; Ratynskaia, S; Roquemore, A; Skinner, C; Solomon, W M

2008-04-23T23:59:59.000Z

52

Dust covering factor, silicate emission and star formation in luminous QSOs  

E-Print Network [OSTI]

We present Spitzer IRS low resolution, mid-IR spectra of a sample of 25 high luminosity QSOs at 2silicate emission feature in the average spectrum, but also in four individual objects. These are the Silicate emission in the most luminous objects obtained so far. When combined with the silicate emission observed in local, low luminosity type-I AGNs, we find that the silicate emission strength is correlated with luminosity. The silicate strength of all type-I AGNs also follows a positive correlation with the black hole mass and with the accretion rate. The Polycyclic Aromatic Hydrocarbon (PAH) emission features, expected from starburst activity, are not detected in the average spectrum of luminous, high-z QSOs. The upper limit inferred from the average spectrum points to a ratio between PAH luminosity and QSO optical luminosity significantly lower than observed in lower luminosity AGNs, implying that the correlation between star formation rate and AGN power saturates at high luminosities.

R. Maiolino; O. Shemmer; M. Imanishi; H. Netzer; E. Oliva; D. Lutz; E. Sturm

2007-04-12T23:59:59.000Z

53

Modified theory of secondary electron emission from spherical particles and its effect on dust charging in complex plasma  

SciTech Connect (OSTI)

The authors have modified Chow's theory of secondary electron emission (SEE) to take account of the fact that the path length of a primary electron in a spherical particle varies between zero to the diameter or x{sub m} the penetration depth depending on the distance of the path from the centre of the particle. Further by including this modified expression for SEE efficiency, the charging kinetics of spherical grains in a Maxwellian plasma has been developed; it is based on charge balance over dust particles and number balance of electrons and ionic species. It is seen that this effect is more pronounced for smaller particles and higher plasma temperatures. Desirable experimental work has also been discussed.

Misra, Shikha [Centre for Energy Studies, Indian Institute of Technology Delhi, New Delhi-110016 (India); Mishra, S. K. [Institute for Plasma Research, Gandhinagar-382428 (India); Sodha, M. S. [Department of Education Building, University of Lucknow, Lucknow-226007 (India)

2013-01-15T23:59:59.000Z

54

The dust sublimation radius as an outer envelope to the bulk of the narrow Fe Kalpha line emission in Type 1 AGN  

E-Print Network [OSTI]

The Fe Kalpha emission line is the most ubiquitous feature in the X-ray spectra of active galactic nuclei (AGN), but the origin of its narrow core remains uncertain. Here, we investigate the connection between the sizes of the Fe Kalpha core emission regions and the measured sizes of the dusty tori in 13 local Type 1 AGN. The observed Fe Kalpha emission radii (R_fe) are determined from spectrally resolved line widths in X-ray grating spectra, and the dust sublimation radii (R_dust) are measured either from optical/near-infrared reverberation time lags or from resolved near-infrared interferometric data. This direct comparison shows that the dust sublimation radius forms an outer envelope to the bulk of the Fe Kalpha emission. R_fe matches R_dust well in the AGN with the best constrained line widths currently. In a significant fraction of objects without a clear narrow line core, R_fe is similar to, or smaller than the radius of the optical broad line region. These facts place important constraints on the toru...

Gandhi, Poshak; Kishimoto, Makoto

2015-01-01T23:59:59.000Z

55

asian dust source: Topics by E-print Network  

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

Natural dust sources globally account for 75 % of emissions; anthropogenic, 25%. North Africa accounts for 55 % of global dust emissions with only 8% being anthropogenic,...

56

Dust Plume Modeling at Fort Bliss: Full Training Scenario  

SciTech Connect (OSTI)

The potential for air quality impacts from heavy mechanized vehicles operating in the training ranges and on the unpaved main supply routes at Fort Bliss is being investigated. The investigation uses the atmospheric modeling system DUSTRAN to simulate fugitive dust emission and dispersion from typical activities occurring on the installation. This report conveys the results of DUSTRAN simulations conducted using a “Full Training” scenario developed by Fort Bliss personnel. he Full Training scenario includes simultaneous off-road activities of two full Heavy Brigade Combat Teams (HCBTs) and one HCBT battalion on three training ranges. Simulations were conducted for the six-day period, April 25-30, 2005, using previously archived meteorological records. Simulation results are presented in the form of 24-hour average PM10 plots and peak 1-hour PM10 concentration plots, where the concentrations represent contributions resulting from the specified military vehicular activities, not total ambient PM10 concentrations. Results indicate that the highest PM10 contribution concentrations occurred on April 30 when winds were light and variable. Under such conditions, lofted particulates generated by vehicular movement stay in the area of generation and are not readily dispersed. The effect of training duration was investigated by comparing simulations with vehicular activity extending over a ten hour period (0700 to 1700 MST) with simulations where vehicular activity was compressed into a one hour period (0700 to 0800 MST). Compressing all vehicular activity into one hour led to higher peak one-hour and 24-hour average concentration contributions, often substantially higher.

Chapman, Elaine G.; Rishel, Jeremy P.; Rutz, Frederick C.; Seiple, Timothy E.; Newsom, Rob K.; Allwine, K Jerry

2006-09-26T23:59:59.000Z

57

Effects of mineral aerosols on the summertime climate of southwest Asia: Incorporating subgrid variability in a dust emission scheme  

E-Print Network [OSTI]

[1] Improvements in modeling mineral aerosols over southwest Asia are made to the dust scheme in a regional climate model by representing subgrid variability of both wind speed and surface roughness length. The new module ...

Marcella, Marc Pace

58

african mineral dust: Topics by E-print Network  

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

Laurent 19 Does the size distribution of mineral dust aerosols depend on the wind speed at emission? CERN Preprints Summary: The size distribution of mineral dust aerosols...

59

Herschel Key Program, "Dust, Ice, and Gas In Time" (DIGIT): the origin of molecular and atomic emission in low-mass protostars in Taurus  

E-Print Network [OSTI]

Six low-mass embedded sources (L1489, L1551-IRS5, TMR1, TMC1-A, L1527, and TMC1) in Taurus have been observed with Herschel-PACS to cover the full spectrum from 50 to 210 $\\mu$m as part of the Herschel key program, "Dust, Ice, and Gas In Time (DIGIT)". The relatively low intensity of the interstellar radiation field surrounding Taurus minimizes contamination of the [C II] emission associated with the sources by diffuse emission from the cloud surface, allowing study of the [C II] emission from the source. In several sources, the [C II] emission is distributed along the outflow, as is the [O I] emission. The atomic line luminosities correlate well with each other, as do the molecular lines, but the atomic and molecular lines correlate poorly. The relative contribution of CO to the total gas cooling is constant at $\\sim$30 %, while the cooling fraction by H$_2$O varies from source to source, suggesting different shock properties resulting in different photodissociation levels of H$_2$O. The gas with a power-law...

Lee, Jeong-Eun; Lee, Seokho; Evans, Neal J; Green, Joel D

2014-01-01T23:59:59.000Z

60

Risk assessment for the Waste Technologies Industries (WTI) hazardous waste incinerator facility (east Liverpool, Ohio). Volume 3. Characterization of the nature and magnitude of emissions. Draft report  

SciTech Connect (OSTI)

This report constitutes a comprehensive site-specific risk assessment for the WTI incineration facility located in East Liverpool, OH. Volume III of the report describes the methods used to estimate both stack and fugitive emission rates from the facility.

NONE

1995-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "fugitive dust emissions" 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

Nondetection of impulsive radio signals from lightning in Martian dust storms using the radar receiver on  

E-Print Network [OSTI]

emission from a Martian dust storm that they attribute to the excitation of Schumann [1952] resonances

Gurnett, Donald A.

62

Role of positively charged dust grains on dust acoustic wave propagation in presence of nonthermal ions  

SciTech Connect (OSTI)

An expression for ion current flowing to the dust grains is proposed, when dust charge is positive and the ions are nonthermal. Secondary electron emission has been considered as the source of positive charging of the dust grains. Investigation shows that presence of positively charged dust grains along with thermal electrons and nonthermal ions generate purely growing dust acoustic waves for both the cases of ion nonthermal parameter greater than one and less than one. In the later case, the growth is conditional.

Sarkar, Susmita; Maity, Saumyen [Department of Applied Mathematics, University of Calcutta, 92, Acharya Prafulla Chandra Road, Kolkata 700009 (India)] [Department of Applied Mathematics, University of Calcutta, 92, Acharya Prafulla Chandra Road, Kolkata 700009 (India)

2013-08-15T23:59:59.000Z

63

E-Print Network 3.0 - atmospheric dust dispersion Sample Search...  

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

of regional dust modelling to the wind speed and the emissions schemes: Impact on the hourly dust previsibility Summary: - Atmospheres , under revision Menut L., 2008,...

64

E-Print Network 3.0 - airborne house dust Sample Search Results  

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

of regional dust modelling to the wind speed and the emissions schemes: Impact... on the hourly dust previsibility Laurent MENUT (1), Cyril MOULIN (2), Isabelle CHIAPELLO (3)...

65

Astrophysics of Dust in Cold Clouds  

E-Print Network [OSTI]

Nine lectures reviewing the astrophysics of dust in interstellar clouds. Topics include: (1) Summary of observational evidence concerning interstellar dust: broadband extinction, scattering of starlight, polarization of starlight, spectroscopy of dust, IR and FIR emission, and depletions of grain-forming elements. (2) Optics of interstellar dust grains: dielectric functions of nonconducting and conducting materials, calculational techniques, formulae valid in the Rayleigh limit, Kramers-Kronig relations, microwave emission mechanisms, and X-ray scattering. (3) IR and FIR emission: heating of interstellar dust, including single-photon heating, and resulting IR emission spectrum. (4) Charging of dust grains: collisional charging, photoelectric emission, and resulting charge distribution functions. (5) Dynamics: gas drag, Lorentz force, forces due to anisotropic radiation, and resulting drift velocities. (6) Rotational dynamics: brownian rotation, suprathermal rotation, and effects of starlight torques. (7) Alignment of interstellar dust: observations and theories. (8) Evolution of the grain population: dust formation in outflows, grain growth in the ISM, photodesorption, and grain destruction in shock waves. (9) Effects of dust grains: photoelectric heating, H2 formation, ion recombination, coupling of gas to magnetic fields, and dust grains as indicators of magnetic field direction.

B. T. Draine

2003-04-28T23:59:59.000Z

66

Assessing the effect of stocking density on fugitive PM10 emissions from cattle feedyards  

E-Print Network [OSTI]

. 30 Table 4. Sampling Event Information, October 1998 . Table 5. Sampling Event Information, December 1998. . . . . . 3 I . . . . 32 Table 6. Sampling Event Information, March 1999 34 Table 7. Sampling Event Information, June/July 1999. 37 Table... I APPENDIX j . . . . 227 . . . . 301 VITA . 306 LIST OF FIGURES Page Figure 1. Sampling Array, August 17 ? 19, 1998. . Figure 2. Sampling Array, August 20, 1998. . Figure 3. Sampling Array, October 1998 Figure 4. Sampling Array, December...

Romanillos, Arturo

2000-01-01T23:59:59.000Z

67

Molten Metal Treatment by Salt Fluxing with Low Environmental Emissions  

SciTech Connect (OSTI)

Abstract: Chlorine gas is traditionally used for fluxing of aluminum melt for removal of alkali and alkaline earth elements. However this results in undesirable emissions of particulate matter and gases such as HCl and chlorine, which are often at unacceptable levels. Additionally, chlorine gas is highly toxic and its handling, storage, and use pose risks to employees and the local community. Holding of even minimal amounts of chlorine necessitates extensive training for all plant employees. Fugitive emissions from chlorine usage within the plant cause accelerated corrosion of plant equipment. The Secondary Aluminum Maximum Achievable Control Technology (MACT) under the Clean Air Act, finalized in March 2000 has set very tough new limits on particulate matter (PM) and total hydrogen chloride emissions from aluminum melting and holding furnaces. These limits are 0.4 and 0.1 lbs per ton of aluminum for hydrogen chloride and particulate emissions, respectively. Assuming new technologies for meeting these limits can be found, additional requirements under the Clean Air Act (Prevention of Significant Deterioration and New Source Review) trigger Best Available Control Technology (BACT) for new sources with annual emissions (net emissions not expressed per ton of production) over specified amounts. BACT currently is lime coated bag-houses for control of particulate and HCl emissions. These controls are expensive, difficult to operate and maintain, and result in reduced American competitiveness in the global economy. Solid salt fluxing is emerging as a viable option for the replacement of chlorine gas fluxing, provided emissions can be consistently maintained below the required levels. This project was a cooperative effort between the Ohio State University and Alcoa to investigate and optimize the effects of solid chloride flux addition in molten metal for alkali impurity and non-metallic inclusion removal minimizing dust and toxic emissions and maximizing energy conservation. In this program, the salt metal interactions were studies and the emissions at laboratory scale at OSU were monitored. The goal of the project was to obtain a fundamental understanding, based on first principles, of the pollutant formation that occurs when the salts are used in furnaces. This information will be used to control process parameters so that emissions are consistently below the required levels. The information obtained in these experiments will be used in industrial furnaces at aluminum plants and which will help in optimizing the process.

Yogeshwar Sahai

2007-07-31T23:59:59.000Z

68

Synthesis of bulk metallic glass foam by powder extrusion with a fugitive second phase  

SciTech Connect (OSTI)

Bulk metallic glass foams with 12 mm in diameter and 30 mm in length having a density of 4.62 g/cm{sup 3} (approximately 58.3% of theoretical) were fabricated by extruding a powder mixture comprised of 60 vol % Ni{sub 59}Zr{sub 20}Ti{sub 16}Si{sub 2}Sn{sub 3} metallic glass blended with 40 vol % brass followed by dissolution of the fugitive brass in an aqueous HNO{sub 3} solution. The final structure consists of continuously connected, high aspect ratio metallic glass struts surrounded by {approx}40 vol % of homogeneously distributed ellipsoid-shaped pores having nominal diameters between 10 and 50 {mu}m.

Lee, Min Ha; Sordelet, Daniel J. [Materials and Engineering Physics Program, Ames Laboratory, Iowa State University, Ames, Iowa 50011 (United States)

2006-07-10T23:59:59.000Z

69

This simple heuristic model describes the basic observed scale sizes of the dust emission in NGC 1068. But how does it relate to the  

E-Print Network [OSTI]

a homogeneous one. Turbulent motions of these clouds with average velocities kvTl classes: compact tori14 , where the dust fills a thick cylinder (with an axial hole) of a few parsecs as given by the outflow cone of ionized gas is inclined by only ,58 out of the plane of sky18 , thus

Khare, Sanjay V.

70

Title V Semi-Annual Emissions Report for Permit P100R1 July 1, 2011 - December 31, 2011  

SciTech Connect (OSTI)

Reports of actual emissions from permitted sources in Section 2.0 shall be submitted on a 6 month basis. Reports shall not include emissions from insignificant activities. Emission estimates of criteria pollutants NOx, CO, SO2, PM and VOCs shall not include fugitive emissions. Emission estimates of HAPs shall include fugitive emissions. The reports shall include a comparison of actual emissions that occurred during the reporting period with the facility-wide allowable emission limits specified in Section 2.11 of this permit. The report required by Condition 4.1 shall be submitted within 90 days from the end of the reporting period. The semiannual report required by Condition 4.2 shall be submitted within 45 days from the end of the reporting period. The reporting periods are January 1st to June 30th and July 1st to December 31st. This condition is pursuant to 20.2.70.302.E.1 NMAC.

Whetham, Walter [Los Alamos National Laboratory

2012-03-15T23:59:59.000Z

71

Electric Dipole Radiation from Spinning Dust Grains  

E-Print Network [OSTI]

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

B. T. Draine; A. Lazarian

1998-02-18T23:59:59.000Z

72

Emissions inventories for MSW landfills under Title V  

SciTech Connect (OSTI)

In the past, many states were either not concerned with, or unaware that, municipal solid waste landfills (MSWLFs) were potential sources of regulated air pollutants. This philosophy is rapidly changing, in part due to US EPA policy documents concerning (and defining) fugitive and non-fugitive emissions from MSWLFs, the attention given to the newly released New Source Performance Standards and a recent lawsuit that gained national notoriety involving landfill air emissions and air permitting applicability issues. Most states now recognize that MSWLFs are sources of regulated air pollutants and are subject to permitting requirements (and pollutant emission fees) as other industries; i.e., state-level minor- and major-source operating permit programs, and the 1990 Clean Air Act Amendments Title V Operating Permits Program (Title V).

Vogt, W.G. [SCS Engineers, Reston, VA (United States); Peyser, T.R. [SCS Engineers, Birmingham, AL (United States); Hamilton, S.M. [SCS Engineers, Tampa, FL (United States)

1996-05-01T23:59:59.000Z

73

Multiwavelength Thermal Emission  

E-Print Network [OSTI]

Multiwavelength Astronomy NASA #12;Thermal Emission #12;Thermal Emission Non-thermal p-p collisions Optical IR Radio/ Microwave sources of emission massive stars, WHIM, Ly many dust, cool objects-ray ~GeV Gamma-ray ~TeV sources of emission AGN, clusters, SNR, binaries, stars AGN (obscured), shocks

California at Santa Cruz, University of

74

Dust and gas in active galaxies  

E-Print Network [OSTI]

There are strong evidences which favour the existence of dust in active galaxies. Understanding the way in which dust interacts with the radiation and influences the physical conditions of the gas is crucial if we want to learn about the nature of the central active nucleus and about the physical conditions of the ISM in such galaxies. Not taking into account such effects may lead us towards misleading interpretations. Many intriguing questions concerns to the nature and the existence of dust in active galaxies: for instance, under which conditions does the very hard ionizing continuum of an AGN allows the survival of dust grains? Is the composition and size distribution of the dust the same as in our local interstellar medium? How is dust distributed compared to the gas which is at least in part highly ionized by the central AGN? Does dust also exist in radio galaxies at very high redshifts? The work developed in this thesis tries to find answers to some of these questions, through a detailed theoretical and observational research of the mechanisms which control the interaction of dust with the radiation and with the ions. The observable effects of the dust on the emission line spectrum are also analyzed in detail. The final goal has been to give clues about more general questions: origin of the emitting gas, ionization mechanisms, geometry, connection between low and high redshift active galaxies or the validity of the unification scenario. This thesis tries, in summary, to provide a clearer understanding of active galaxies in general.

M. Villar-Martin

1996-05-21T23:59:59.000Z

75

E-Print Network 3.0 - asymmetric dust shell Sample Search Results  

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

that this is thermal emission from silicate dust that con- densed out in the red giant wind of the progenitor star... . The dust temperature is 166 18 12 K, and the emitting...

76

Anomalous Microwave Emission  

E-Print Network [OSTI]

Improved knowledge of diffuse Galactic emission is important to maximize the scientific return from scheduled CMB anisotropy missions. Cross-correlation of microwave maps with maps of the far-IR dust continuum show a ubiquitous microwave emission component whose spatial distribution is traced by far-IR dust emission. The spectral index of this emission, beta_{radio} = -2.2 (+0.5 -0.7) is suggestive of free-free emission but does not preclude other candidates. Comparison of H-alpha and microwave results show that both data sets have positive correlations with the far-IR dust emission. Microwave data, however, are consistently brighter than can be explained solely from free-free emission traced by H-alpha. This ``anomalous'' microwave emission can be explained as electric dipole radiation from small spinning dust grains. The anomalous component at 53 GHz is 2.5 times as bright as the free-free emission traced by H-alpha, providing an approximate normalization for models with significant spinning dust emission.

A. Kogut

1999-02-22T23:59:59.000Z

77

age-dependent dust heating: Topics by E-print Network  

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

correlations. Zeljko Ivezic; Moshe Elitzur 1996-12-17 17 Spatial distribution of Far infrared emission in spiral galaxies II. Heating sources and gas-to-dust ratio...

78

Niamey Dust Observations  

DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

Niamey aerosol are composed of two main components: dust due to the proximity of the Sahara Desert, and soot from local and regional biomass burning. The purpose of this data product is to identify when the local conditions are dominated by the dust component so that the properties of the dust events can be further studied.

Flynn, Connor

79

Tax Credits, Rebates & Savings | Department of Energy  

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

Air Pollution Control Regulations: No. 5- Fugitive Dust (Rhode Island) These regulations aim to prevent the release of fugitive dust by forbidding the handling, transportation,...

80

Sequim Site Radionuclide Air Emissions Report for Calendar Year 2012  

SciTech Connect (OSTI)

This report is prepared to document compliance with the Code of Federal Regulations (CFR), Title 40, Protection of the Environment, Part 61, National Emission Standards for Hazardous Air Pollutants (NESHAP), Subpart H, National Emission Standards for Emissions of Radionuclides Other than Radon from Department of Energy Facilities and ashington Administrative Code (WAC) Chapter 246-247, Radiation Protection Air Emissions. This report meets the calendar year 2012 Sequim Site annual reporting requirement for its operations as a privately-owned facility as well as its federally-contracted status that began in October 2012. Compliance is indicated by comparing the estimated dose to the maximally exposed individual (MEI) with the 10 mrem/yr Environmental Protection Agency (EPA) standard. The MSL contains only sources classified as fugitive emissions. Despite the fact that the regulations are intended for application to point source emissions, fugitive emissions are included with regard to complying with the EPA standard. The dose to the Sequim Site MEI due to routine operations in 2012 was 9E-06 mrem (9E-08 mSv). No non-routine emissions occurred in 2012. The MSL is in compliance with the federal and state 10 mrem/yr standard.

Snyder, Sandra F.; Barnett, J. M.; Gervais, Todd L.

2013-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "fugitive dust emissions" 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

Optical Investigations of Dust Particles Distribution in RF and DC Discharges  

SciTech Connect (OSTI)

Optical emission spectroscopy is used to study dust particles movement and conditions of a formation of ordered plasma-dust structures in a capacitively coupled RF discharge. 3D binocular diagnostics of plasma-dust structures in dc discharge was made.

Ramazanov, T. S.; Dosbolayev, M. K.; Jumabekov, A. N.; Amangaliyeva, R. Zh. [Al-Farabi Kazakh National University, IETP, 96a Tole Bi St., Almaty 050012 (Kazakhstan); Filatova, I. I.; Azharonok, V. V. [B. I. Stepanov Institute of Physics NAS of Belarus, Nezavisimosti Ave., 68, 220072, Minsk (Belarus)

2008-09-07T23:59:59.000Z

82

Radionuclide Air Emissions Report for the Hanford Site Calendar Year 1999  

SciTech Connect (OSTI)

This report documents radionuclide air emissions from the US. Department of Energy (DOE) Hanford Site in 1999 and the resulting effective dose equivalent to the maximally exposed individual (MEI) member of the public. The report has been prepared in accordance with the Code of Federal Regulations (CFR). Title 40, Protection of the Environment, Part 61. National Emission Standards for Hazardous Air Pollutants, Subpart H, ''National Emission Standards for Emissions of Radionuclides Other than Radon from Department of Energy Facilities'', and with the Washington Administrative Code (WAC) Chapter 246-247. Radiation Protection-Air Emissions. The federal regulations in Subpart H of 40 CFR 61 require the measurement and reporting of radionuclides emitted from US. Department of Energy (DOE) facilities and the resulting offsite dose from those emissions. A standard of 10 mrem/yr effective dose equivalent (EDE) is imposed on them. The EDE to the MEI due to routine emissions in 1999 from Hanford Site point sources was 0.029 mrem (2.9 E-04 mSv), which is less than 0.3 percent of the federal standard. WAC 246-247 requires the reporting of radionuclide emissions from all Hanford Site sources, during routine as well as nonroutine operations. The state has adopted the 40 CFR 61 standard of 10 mrem/yr EDE into their regulations. The state further requires that the EDE to the MEI be calculated not only from point source emissions but also from diffuse and fugitive sources of emissions. The EDE from diffuse and fugitive emissions at the Hanford Site in 1999 was 0.039 mrem (3.9 E-04 mSv) EDE. The total dose from point sources and from diffuse and fugitive sources of radionuclide emissions during all operating conditions in 1999 was 0.068 mrem (6.8 E-04 mSv) EDE, which is less than 0.7 percent of the state standard.

ROKKAN, D.J.

2000-06-01T23:59:59.000Z

83

THE DUST BUDGET OF THE SMALL MAGELLANIC CLOUD: ARE ASYMPTOTIC GIANT BRANCH STARS THE PRIMARY DUST SOURCE AT LOW METALLICITY?  

SciTech Connect (OSTI)

We estimate the total dust input from the cool evolved stars in the Small Magellanic Cloud, using the 8 {mu}m excess emission as a proxy for the dust-production rate (DPR). We find that asymptotic giant branch (AGB) and red supergiant (RSG) stars produce (8.6-9.5) Multiplication-Sign 10{sup -7} M{sub Sun} yr{sup -1} of dust, depending on the fraction of far-infrared sources that belong to the evolved star population (with 10%-50% uncertainty in individual DPRs). RSGs contribute the least (<4%), while carbon-rich AGB stars (especially the so-called extreme AGB stars) account for 87%-89% of the total dust input from cool evolved stars. We also estimate the dust input from hot stars and supernovae (SNe), and find that if SNe produce 10{sup -3} M{sub Sun} of dust each, then the total SN dust input and AGB input are roughly equivalent. We consider several scenarios of SN dust production and destruction and find that the interstellar medium (ISM) dust can be accounted for solely by stellar sources if all SNe produce dust in the quantities seen around the dustiest examples and if most SNe explode in dense regions where much of the ISM dust is shielded from the shocks. We find that AGB stars contribute only 2.1% of the ISM dust. Without a net positive contribution from SNe to the dust budget, this suggests that dust must grow in the ISM or be formed by another unknown mechanism.

Boyer, M. L.; Gordon, K. D.; Meixner, M.; Sargent, B. A. [STScI, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Srinivasan, S. [UPMC-CNRS UMR7095, Institut d'Astrophysique de Paris, F-75014 Paris (France); Riebel, D. [Department of Physics and Astronomy, The Johns Hopkins University, Homewood Campus, Baltimore, MD 21218 (United States); McDonald, I. [Jodrell Bank Centre for Astrophysics, Alan Turing Building, University of Manchester, Manchester M13 9PL (United Kingdom); Van Loon, J. Th. [Astrophysics Group, Lennard-Jones Laboratories, Keele University, Staffordshire ST5 5BG (United Kingdom); Clayton, G. C. [Department of Physics and Astronomy, Louisiana State University, 233-A Nicholson Hall, Tower Dr., Baton Rouge, LA 70803-4001 (United States); Sloan, G. C., E-mail: mboyer@stsci.edu [Astronomy Department, Cornell University, Ithaca, NY 14853-6801 (United States)

2012-03-20T23:59:59.000Z

84

Pacific Northwest National Laboratory Site Radionuclide Air Emissions Report for Calendar Year 2012  

SciTech Connect (OSTI)

This report documents radionuclide air emissions that result in the highest effective dose equivalent (EDE) to a member of the public, referred to as the maximally exposed individual (MEI). The report has been prepared in compliance with the Code of Federal Regulations (CFR), Title 40, Protection of the Environment, Part 61, National Emission Standards for Hazardous Air Pollutants (NESHAP), Subpart H, National Emission Standards for Emissions of Radionuclides Other than Radon from Department of Energy Facilities and Washington Administrative Code (WAC) Chapter 246-247, Radiation Protection Air Emissions. The dose to the PNNL Site MEI due to routine major and minor point source emissions in 2012 from PNNL Site sources is 9E-06 mrem (9E-08 mSv) EDE. The dose from fugitive emissions (i.e., unmonitored sources) is 1E-7 mrem (1E-9 mSv) EDE. The dose from radon emissions is 2E-6 mrem (2E-08 mSv) EDE. No nonroutine emissions occurred in 2012. The total radiological dose for 2012 to the MEI from all PNNL Site radionuclide emissions, including fugitive emissions and radon, is 1E-5 mrem (1E-7 mSv) EDE, or 100,000 times smaller than the federal and state standard of 10 mrem/yr, to which the PNNL Site is in compliance.

Snyder, Sandra F.; Barnett, J. M.; Bisping, Lynn E.

2013-06-06T23:59:59.000Z

85

Pacific Northwest National Laboratory Campus Radionuclide Air Emissions Report for Calendar Year 2013  

SciTech Connect (OSTI)

This report documents radionuclide air emissions that result in the highest effective dose equivalent (EDE) to a member of the public, referred to as the maximally exposed individual (MEI). The report has been prepared in compliance with the Code of Federal Regulations (CFR), Title 40, Protection of the Environment, Part 61, National Emission Standards for Hazardous Air Pollutants (NESHAP), Subpart H, National Emission Standards for Emissions of Radionuclides Other than Radon from Department of Energy Facilities and Washington Administrative Code (WAC) Chapter 246-247, Radiation Protection Air Emissions. The dose to the PNNL Site MEI due to routine major and minor point source emissions in 2013 from PNNL Site sources is 2E-05 mrem (2E-07 mSv) EDE. The dose from fugitive emissions (i.e., unmonitored sources) is 2E-6 mrem (2E-8 mSv) EDE. The dose from radon emissions is 1E-11 mrem (1E-13 mSv) EDE. No nonroutine emissions occurred in 2013. The total radiological dose for 2013 to the MEI from all PNNL Site radionuclide emissions, including fugitive emissions and radon, is 2E-5 mrem (2E-7 mSv) EDE, or 100,000 times smaller than the federal and state standard of 10 mrem/yr, to which the PNNL Site is in compliance

Snyder, Sandra F.; Barnett, J. M.; Bisping, Lynn E.

2014-06-01T23:59:59.000Z

86

COLD DUST BUT WARM GAS IN THE UNUSUAL ELLIPTICAL GALAXY NGC 4125  

SciTech Connect (OSTI)

Data from the Herschel Space Observatory have revealed an unusual elliptical galaxy, NGC 4125, which has strong and extended submillimeter emission from cold dust but only very strict upper limits to its CO and H I emission. Depending on the dust emissivity, the total dust mass is 2-5 × 10{sup 6} M {sub ?}. While the neutral gas-to-dust mass ratio is extremely low (<12-30), including the ionized gas traced by [C II] emission raises this limit to <39-100. The dust emission follows a similar r {sup 1/4} profile to the stellar light and the dust to stellar mass ratio is toward the high end of what is found in nearby elliptical galaxies. We suggest that NGC 4125 is currently in an unusual phase where evolved stars produced in a merger-triggered burst of star formation are pumping large amounts of gas and dust into the interstellar medium. In this scenario, the low neutral gas-to-dust mass ratio is explained by the gas being heated to temperatures ?10{sup 4} K faster than the dust is evaporated. If galaxies like NGC 4125, where the far-infrared emission does not trace neutral gas in the usual manner, are common at higher redshift, this could have significant implications for our understanding of high redshift galaxies and galaxy evolution.

Wilson, C. D.; Cridland, A.; Foyle, K.; Parkin, T. J.; Cooper, E. Mentuch [Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1 (Canada)] [Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1 (Canada); Roussel, H. [Institut d'Astrophysique de Paris, Université Pierre et Marie Curie, CNRS UMR 7095, F-75014 Paris (France)] [Institut d'Astrophysique de Paris, Université Pierre et Marie Curie, CNRS UMR 7095, F-75014 Paris (France); Sauvage, M.; Lebouteiller, V.; Madden, S. [Laboratoire AIM, CEA/DSM-CNRS-Université Paris Diderot DAPNIA/Service d'Astrophysique, Bât. 709, CEA-Saclay, F-91191 Gif-sur-Yvette Cedex (France)] [Laboratoire AIM, CEA/DSM-CNRS-Université Paris Diderot DAPNIA/Service d'Astrophysique, Bât. 709, CEA-Saclay, F-91191 Gif-sur-Yvette Cedex (France); Smith, M. W. L.; Gear, W. [School of Physics and Astronomy, Cardiff University, The Parade, Cardiff CF24 3AA (United Kingdom)] [School of Physics and Astronomy, Cardiff University, The Parade, Cardiff CF24 3AA (United Kingdom); Baes, M.; De Looze, I. [Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, B-9000 Gent (Belgium)] [Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, B-9000 Gent (Belgium); Bendo, G. [UK ALMA Regional Centre Node, Jodrell Bank Center for Astrophysics, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom)] [UK ALMA Regional Centre Node, Jodrell Bank Center for Astrophysics, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Boquien, M.; Boselli, A.; Ciesla, L. [Aix-Marseille Université, CNRS, LAM (Laboratoire d'Astrophysique de Marseille) UMR 7326, F-13388 Marseille (France)] [Aix-Marseille Université, CNRS, LAM (Laboratoire d'Astrophysique de Marseille) UMR 7326, F-13388 Marseille (France); Clements, D. L. [Astrophysics Group, Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2AZ (United Kingdom)] [Astrophysics Group, Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2AZ (United Kingdom); Cooray, A. [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States)] [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Galametz, M. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom)] [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); and others

2013-10-20T23:59:59.000Z

87

Dust around Type Ia supernovae  

E-Print Network [OSTI]

Dust around Type Ia supernovae Lifan Wang 1,2 LawrenceIa. Subject headings: Supernovae: General, Dust, Extinctionline) bands for Type Ia supernovae. (a), upper panel, shows

Wang, Lifan

2005-01-01T23:59:59.000Z

88

The Differential Lifetimes of Protostellar Gas and Dust Disks  

E-Print Network [OSTI]

We construct a protostellar disk model that takes into account the combined effect of viscous evolution, photoevaporation and the differential radial motion of dust grains and gas. For T Tauri disks, the lifetimes of dust disks that are mainly composed of millimeter sized grains are always shorter than the gas disks' lifetimes, and become similar only when the grains are fluffy (density 10 AU), without strong signs of gas accretion nor of millimeter thermal emission from the dust. For Herbig AeBe stars, the strong photoevaporation clears the inner disks in 10^6 yr, before the dust grains in the outer disk migrate to the inner region. In this case, the grains left behind in the outer gas disk accumulate at the disk inner edge (at 10-100 AU from the star). The dust grains remain there even after the entire gas disk has been photoevaporated, and form a gas-poor dust ring similar to that observed around HR 4796A. Hence, depending on the strength of the stellar ionizing flux, our model predicts opposite types of products around young stars. For low mass stars with a low photoevaporation rate, dust-poor gas disks with an inner hole would form, whereas for high mass stars with a high photoevaporation rate, gas-poor dust rings would form. This prediction should be examined by observations of gas and dust around weak line T Tauri stars and evolved Herbig AeBe stars.

Taku Takeuchi; C. J. Clarke; D. N. C. Lin

2005-03-22T23:59:59.000Z

89

Anomalous Emission from HII regions  

E-Print Network [OSTI]

Spinning dust appears to be the best explanation for the anomalous emission that has been observed at $\\sim 10-60$ GHz. One of the best examples of spinning dust comes from a HII region in the Perseus molecular cloud. Observations of other HII regions also show tentative evidence for excess emission at frequencies $\\sim 30$ GHz, although at lower emissivity levels. A new detection of excess emission at 31 GHz in the HII region RCW175 has been made. The most plausible explanation again comes from spinning dust. HII regions are a good place to look for spinning dust as long as accurate radio data spanning the $\\sim 5-100$ GHz range is available.

C. Dickinson

2008-08-04T23:59:59.000Z

90

The ecology of dust: local- to global-scale perspectives  

SciTech Connect (OSTI)

Emission and redistribution of dust due to wind erosion in drylands drives major biogeochemical dynamics and provides important aeolian environmental connectivity at scales from individual plants up to the global scale. Yet, perhaps because most relevant research on aeolian processes has been presented in a geosciences rather than ecological context, most ecological studies do not explicitly consider dust-driven processes. To bridge this disciplinary gap, we provide a general overview of the ecological importance of dust, examine complex interactions between wind erosion and ecosystem dynamics from the plant-interspace scale to regional and global scales, and highlight specific examples of how disturbance affects these interactions and their consequences. Changes in climate and intensification of land use will both likely lead to increased dust production. To address these challenges, environmental scientists, land managers and policy makers need to more explicitly consider dust in resource management decisions.

Whicker, Jeffrey J [Los Alamos National Laboratory; Field, Jason P [UA; Belnap, Jayne [NON LANL; Breshears, David D [UA; Neff, Jason [CU; Okin, Gregory S [UCLA; Painter, Thomas H [UNIV OF ARIZONA; Ravi, Sujith [UNIV OF ARIZONA; Reheis, Marith C [UCLA; Reynolds, Richard L [NON LANL

2009-01-01T23:59:59.000Z

91

Secondary dust density waves excited by nonlinear dust acoustic waves  

SciTech Connect (OSTI)

Secondary dust density waves were observed in conjunction with high amplitude (n{sub d}/n{sub d0}>2) dust acoustic waves (DAW) that were spontaneously excited in a dc glow discharge dusty plasma in the moderately coupled, {Gamma}{approx}1, state. The high amplitude dust acoustic waves produced large dust particle oscillations, displacements, and trapping. Secondary dust density waves were excited in the wave troughs of the high amplitude DAWs. The waveforms, amplitudes, wavelengths, and wave speeds of the primary DAWs and the secondary waves were measured. A dust-dust streaming instability is discussed as a possible mechanism for the production of the secondary waves.

Heinrich, J. R.; Kim, S.-H.; Meyer, J. K.; Merlino, R. L. [Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242 (United States); Rosenberg, M. [Department of Electrical and Computer Engineering, University of California, San Diego, California 92093 (United States)

2012-08-15T23:59:59.000Z

92

Electrostatic dust detector  

DOE Patents [OSTI]

An apparatus for detecting dust in a variety of environments which can include radioactive and other hostile environments both in a vacuum and in a pressurized system. The apparatus consists of a grid coupled to a selected bias voltage. The signal generated when dust impacts and shorts out the grid is electrically filtered, and then analyzed by a signal analyzer which is then sent to a counter. For fine grids a correlation can be developed to relate the number of counts observed to the amount of dust which impacts the grid.

Skinner, Charles H. (Lawrenceville, NJ)

2006-05-02T23:59:59.000Z

93

Cotton Gin Dust Explosibility Determinations  

E-Print Network [OSTI]

personnel listed dust found in cotton gins, or gin dust, fueled two explosions in the past. OSHA is required by law to regulate facilities handling explosible dusts to provide a safe working environment for employees. The dust handling facilities must test...

Vanderlick, Francis Jerome

2014-01-06T23:59:59.000Z

94

The large scale dust lanes of the Galactic bar  

E-Print Network [OSTI]

(abridged) By comparing the distribution of dust and gas in the central regions of the Galaxy, we aim to obtain new insights into the properties of the offset dust lanes leading the bar's major axis in the Milky Way. On the one hand, the molecular emission of the dust lanes is extracted from the observed CO l-b-V distribution according to the interpretation of a dynamical model. On the other hand, a three dimensional extinction map of the Galactic central region constructed from near-infrared observations is used as a tracer of the dust itself and clearly reveals dust lanes in its face-on projection. Comparison of the position of both independent detections of the dust lanes is performed in the (l, b) plane. These two completely independent methods are used to provide a coherent picture of the dust lanes in the Milky Way bar. In both the gas and dust distributions, the dust lanes are found to be out of the Galactic plane, appearing at negative latitudes for l > 0 deg and at positive latitudes for l reformation downstream. Due to the decrease in velocity caused by the shock, this occurs at lower z. The second assumes that the gas and dust remain on a common tilted plane, but that the molecular gas decouples from the Milky Way's magnetic field, itself strong enough to resist the shear of the bar's shock. The diffuse gas and dust remain coupled to the field and are carried further downstream. This second scenario has recently been suggested in order to explain observations of the barred galaxy NGC 1097.

D. J. Marshall; R. Fux; A. C. Robin; C. Reyle

2007-11-15T23:59:59.000Z

95

Dust Formation Events in Colliding Winds: an application to eta Car  

E-Print Network [OSTI]

Recent IR observations indicate that many massive binary systems present dust formation episodes, in regions close to the stars, during the periastron passage. These systems are known to be high-energy sources, and it is believed that wind collisions are the origin of the emission. In this work we show that wind collisions not only increase the X-ray emission but also allow dust formation. As an application we study eta Car, which presents, near periastron, an increase in the X-ray emission followed by a sudden decrease that lasts for about a month. We reproduce this feature calculating the optical depth due to dust formation along the orbital period.

D. Falceta-Goncalves; V. Jatenco-Pereira; Z. Abraham

2002-10-29T23:59:59.000Z

96

Effect of energetic electrons on dust charging in hot cathode filament discharge  

SciTech Connect (OSTI)

The effect of energetic electrons on dust charging for different types of dust is studied in hydrogen plasma. The hydrogen plasma is produced by hot cathode filament discharge method in a dusty plasma device. A full line cusped magnetic field cage is used to confine the plasma elements. To study the plasma parameters for various discharge conditions, a cylindrical Langmuir probe having 0.15 mm diameter and 10.0 mm length is used. An electronically controlled dust dropper is used to drop the dust particles into the plasma. For different discharge conditions, the dust current is measured using a Faraday cup connected to an electrometer. The effect of secondary emission as well as discharge voltage on charging of dust grains in hydrogen plasma is studied with different dust.

Kakati, B.; Kausik, S. S.; Saikia, B. K. [Centre of Plasma Physics, Institute for Plasma Research, Nazirakhat, Sonapur 782 402, Kamrup, Assam (India); Bandyopadhyay, M. [ITER-India, Institute for Plasma Research, Bhat, Gandhinagar 382 428 (India)

2011-03-15T23:59:59.000Z

97

Dust cluster explosion  

SciTech Connect (OSTI)

A model for the dust cluster explosion where micron/sub-micron sized particles are accelerated at the expense of plasma thermal energy, in the afterglow phase of a complex plasma discharge is proposed. The model is tested by molecular dynamics simulations of dust particles in a confining potential. The nature of the explosion (caused by switching off the discharge) and the concomitant dust acceleration is found to depend critically on the pressure of the background neutral gas. At low gas pressure, the explosion is due to unshielded Coulomb repulsion between dust particles and yields maximum acceleration, while in the high pressure regime it is due to shielded Yukawa repulsion and yields much feebler acceleration. These results are in agreement with experimental findings. Our simulations also confirm a recently proposed electrostatic (ES) isothermal scaling relation, P{sub E}{proportional_to}V{sub d}{sup -2} (where P{sub E} is the ES pressure of the dust particles and V{sub d} is the confining volume).

Saxena, Vikrant [School of Mathematics and Physics, Queen's University Belfast, Belfast, Northern Ireland (United Kingdom); Institute for Plasma Research, Bhat, Gandhinagar (India); Avinash, K. [Department of Physics and Astrophysics, University of Delhi, New Delhi (India); Sen, A. [Institute for Plasma Research, Bhat, Gandhinagar (India)

2012-09-15T23:59:59.000Z

98

DATE  

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

in nuclear reactors). SECTION C. Environmental Aspects Potential Sources of Impact 1. Air Pollutants - Fugitive dust may be generated during maintenance activities. All fugitive...

99

Practical guide: Tools and methodologies for an oil and gas industry emission inventory  

SciTech Connect (OSTI)

During the preparation of Title V Permit applications, the quantification and speciation of emission sources from oil and gas facilities were reevaluated to determine the {open_quotes}potential-to-emit.{close_quotes} The existing emissions were primarily based on EPA emission factors such as AP-42, for tanks, combustion sources, and fugitive emissions from component leaks. Emissions from insignificant activities and routine operations that are associated with maintenance, startups and shutdowns, and releases to control devices also required quantification. To reconcile EPA emission factors with test data, process knowledge, and manufacturer`s data, a careful review of other estimation options was performed. This paper represents the results of this analysis of emission sources at oil and gas facilities, including exploration and production, compressor stations and gas plants.

Thompson, C.C. [C-K Associates, Inc., Baton Rouge, LA (United States); Killian, T.L. [Conoco, Inc., Houston, TX (United States)

1996-12-31T23:59:59.000Z

100

TWO INTERSTELLAR DUST CANDIDATES FROM THE STARDUST AEROGEL INTERSTELLAR DUST  

E-Print Network [OSTI]

TWO INTERSTELLAR DUST CANDIDATES FROM THE STARDUST AEROGEL INTERSTELLAR DUST COLLECTOR A. J, and is expected to have collected several dozen contemporary interstellar dust particles in aerogel and aluminum@home, we have so far identified 28 tracks in the aerogel collectors. We report on the results

Nittler, Larry R.

Note: This page contains sample records for the topic "fugitive dust emissions" 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

ISO observations of spirals: modelling the FIR emission  

E-Print Network [OSTI]

ISO observations at 200 micron have modified our view of the dust component in spiral galaxies. For a sample of seven resolved spirals we have retrieved a mean temperature of 20K, about 10K lower than previous estimates based on IRAS data at shorter wavelengths. Because of the steep dependence of far-infrared emission on the dust temperature, the dust masses inferred from ISO fluxes are a factor of 10 higher than those derived from IRAS data only, leading to gas-to-dust ratios close to the value observed in the Galaxy. The scale-length of the 200 micron emission is larger than for the IRAS 100 micron emission, with colder dust at larger distances from the galactic centre, as expected if the interstellar radiation field is the main source of dust heating. The 200 micron scale-length is also larger than the optical, for all the galaxies in the sample. This suggests that the dust distribution is more extended than that of the stars.A model of the dust heating is needed to derive the parameters of the dust distribution from the FIR emission. Therefore, we have adapted an existing radiative transfer code to deal with dust emission. Simulated maps of the temperature distribution within the dust disk and of the dust emission at any wavelength can be produced. The stellar spectral energy distribution is derived from observations in the ultraviolet, optical and near infrared. The parameters of the dust distribution (scale-lengths and optical depth) are chosen to reproduce the observed characteristics of the FIR emission, i.e. the shape of the spectrum, the flux and the spatial distribution. We describe the application of the model to one of the galaxies in the sample, NGC 6946.

Simone Bianchi; Paul B. Alton; Jonathan I. Davies

1999-10-01T23:59:59.000Z

102

An Unbiased Near-infrared Interferometric Survey for Hot Exozodiacal Dust  

E-Print Network [OSTI]

Exozodiacal dust is warm or hot dust found in the inner regions of planetary systems orbiting main sequence stars, in or around their habitable zones. The dust can be the most luminous component of extrasolar planetary systems, but predominantly emits in the near- to mid-infrared where it is outshone by the host star. Interferometry provides a unique method of separating this dusty emission from the stellar emission. The visitor instrument PIONIER at the Very Large Telescope Interferometer (VLTI) has been used to search for hot exozodiacal dust around a large sample of nearby main sequence stars. The results of this survey are summarised: 9 out of 85 stars show excess exozodiacal emission over the stellar photospheric emission.

Ertel, Steve; Absil, Olivier; Defrère, Denis; LeBouquin, Jean-Baptiste; Marion, Lindsay; Bonsor, Amy; Lebreton, Jérémy

2015-01-01T23:59:59.000Z

103

Spectroscopic diagnostic for the mineralogy of large dust grains  

E-Print Network [OSTI]

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

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

2003-10-30T23:59:59.000Z

104

Dust production 680-850 million years after the Big Bang  

E-Print Network [OSTI]

Dust plays an important role in our understanding of the Universe, but it is not obvious yet how the dust in the distant universe was formed. I derived the dust yields per asymptotic giant branch (AGB) star and per supernova (SN) required to explain dust masses of galaxies at z = 6.3-7.5 (680-850 million years after the Big Bang) for which dust emission has been detected (HFLS3 at z = 6.34, ULAS J1120+0641 at z = 7.085, and A1689-zD1 at z = 7.5), or unsuccessfully searched for. I found very high required yields, implying that AGB stars could not contribute substantially to dust production at these redshifts, and that SNe could explain these dust masses, but only if they do not destroy majority of the dust they form (which is unlikely given the upper limits on the SN dust yields derived for dust non-detected galaxies). This suggests that the grain growth in the interstellar medium is likely required at these early epochs.

Micha?owski, Micha? J

2015-01-01T23:59:59.000Z

105

Air quality impacts analysis for area G. Final report  

SciTech Connect (OSTI)

The impact of fugitive radioactive emissions from the disposal site, Area G, was evaluated in support of site characterization for the Performance Assessment and for the Radioactive Air Emissions Management (RAEM) program. Fugitive emissions of tritiated water and contaminated windblown dust were considered. Data from an extensive field measurement program were used to estimate annual emissions of tritiated water. Fugitive dust models were used to calculate estimates of the annual emissions of windblown dust. These estimates were combined with data on contamination levels in surface soils to develop annual emission rates for specific radionuclides: tritium, uranium-238, cesium-137, plutonium-238, plutonium-239,240, and strontium-90. The CAP-88 atmospheric transport model was used to predict areas potentially affected by long-term dust deposition and atmospheric concentrations. The annual emission rate of tritiated water was estimated from the field data to be 14.0 Ci/yr. The emission rate of soil-borne radionuclides from open areas and from soils handling operations totaled less than 1x10{sup -4} Ci/yr. The CAP-88 results were used to develop effective dose equivalents (EDEs) for receptor locations downwind of Area G. All EDEs were several orders of magnitude below the national standard of 10 mrem/yr. Fugitive air emissions from Area G were found not to pose a health threat to persons living or working downwind of the facility.

Kowalewsky, K.; Eklund, B. [Radian Corp., Austin, TX (United States); Vold, E.L. [Los Alamos National Lab., NM (United States)

1995-07-05T23:59:59.000Z

106

Dust and Molecules at High Redshift  

E-Print Network [OSTI]

In the last years, progress has been very rapid in the domain of molecules at high redshift, and we know in better detail now the molecular and dust content in several systems beyond z=1 and up to z = 5. The first discovery in 1992 by Brown and van den Bout of CO lines at z=2.28 in a gravitationally lensed starburst galaxy, strongly stimulated searches of other systems, but these were harder than foreseen, and less than 10 other systems have been discovered in CO emission. Redshifts range between 2 and 5, the largest being BR1202-0725 at z=4.69. Most of these systems, if not all, are gravitationally amplified objects. Some have been discovered first through their dust emission, relatively easy to detect because of the negative K-correction effect. The detection of all these systems could give an answer about the debated question of the star-formation rate as a function of redshift. The maximum of star-formation rate, found around z=2 from optical studies, could shift to higher z if the most remote objects are hidden by dust. Absorption in front of quasars can also probe cold gas at high redshift, taking advantage of very high spatial (milli arcsec) and spectral (30m/s) resolutions. From the diffuse components, one can measure the cosmic black body temperature as a function of redshift. All these preliminary studies will be carried out at large scales with future millimeter instruments, and some perspectives are given.

F. Combes

1998-12-23T23:59:59.000Z

107

Uncertainty in Modeling Dust Mass Balance and Radiative Forcing from Size Parameterization  

SciTech Connect (OSTI)

This study examines the uncertainties in simulating mass balance and radiative forcing of mineral dust due to biases in the aerosol size parameterization. Simulations are conducted quasi-globally (180oW-180oE and 60oS-70oN) using the WRF24 Chem model with three different approaches to represent aerosol size distribution (8-bin, 4-bin, and 3-mode). The biases in the 3-mode or 4-bin approaches against a relatively more accurate 8-bin approach in simulating dust mass balance and radiative forcing are identified. Compared to the 8-bin approach, the 4-bin approach simulates similar but coarser size distributions of dust particles in the atmosphere, while the 3-mode pproach retains more fine dust particles but fewer coarse dust particles due to its prescribed og of each mode. Although the 3-mode approach yields up to 10 days longer dust mass lifetime over the remote oceanic regions than the 8-bin approach, the three size approaches produce similar dust mass lifetime (3.2 days to 3.5 days) on quasi-global average, reflecting that the global dust mass lifetime is mainly determined by the dust mass lifetime near the dust source regions. With the same global dust emission (~6000 Tg yr-1), the 8-bin approach produces a dust mass loading of 39 Tg, while the 4-bin and 3-mode approaches produce 3% (40.2 Tg) and 25% (49.1 Tg) higher dust mass loading, respectively. The difference in dust mass loading between the 8-bin approach and the 4-bin or 3-mode approaches has large spatial variations, with generally smaller relative difference (<10%) near the surface over the dust source regions. The three size approaches also result in significantly different dry and wet deposition fluxes and number concentrations of dust. The difference in dust aerosol optical depth (AOD) (a factor of 3) among the three size approaches is much larger than their difference (25%) in dust mass loading. Compared to the 8-bin approach, the 4-bin approach yields stronger dust absorptivity, while the 3-mode approach yields weaker dust absorptivity. Overall, on quasi-global average, the three size parameterizations result in a significant difference of a factor of 2~3 in dust surface cooling (-1.02~-2.87 W m-2) and atmospheric warming (0.39~0.96 W m-2) and in a tremendous difference of a factor of ~10 in dust TOA cooling (-0.24~-2.20 W m-2). An uncertainty of a factor of 2 is quantified in dust emission estimation due to the different size parameterizations. This study also highlights the uncertainties in modeling dust mass and number loading, deposition fluxes, and radiative forcing resulting from different size parameterizations, and motivates further investigation of the impact of size parameterizations on modeling dust impacts on air quality, climate, and ecosystem.

Zhao, Chun; Chen, Siyu; Leung, Lai-Yung R.; Qian, Yun; Kok, Jasper; Zaveri, Rahul A.; Huang, J.

2013-11-05T23:59:59.000Z

108

Characterization of secondary grain dust explosions  

E-Print Network [OSTI]

dust less than 106 um . . . ~ . . ~ ~ ~ ~ 27 4 Coulter Counter particle size distribution for wheat dust less than 106 um . 28 5 Coulter Counter particle size distribution for rice dust less than 106 um ~ 29 6 Coulter Counter particle size... distribution f' or wheat/sorghum dust, less than 106 um . 7 Coulter Counter particle size distribution for soybean dust less than 106 um 31 8 Coulter Counter particle size distribution for corn dust between 106 and. 250 um 9 Coulter Counter particle size...

Schulman, Cheryl Wendler

2012-06-07T23:59:59.000Z

109

Cyborg Bugs... and Neural Dust  

E-Print Network [OSTI]

Cyborg Bugs... and Neural Dust Michel M. Maharbiz © 2014 D.J. Seo Elad Alon system Seo D, et al. "Neural Dust: An Ultrasonic, Low Power SoluNon for Chronic Brain-Machine Interfaces," arXiv, Jul. 2013 Seo D, et al. "In Vitro Characteriza

California at Irvine, University of

110

Microchemical investigations of dust emitted by a lead smelter  

SciTech Connect (OSTI)

Dusts emitted by an important pyrometallurgical lead smelter have been sampled within the pipes of the grilling and furnace working units before and after the filtering systems, respectively. Particle size distribution, elementary analyses, and X-ray powder diffraction analysis indicate PbS, PbSO{sub 4}, PbSO{sub 4}{center_dot}PbO, Pb, ZnS small particles less than 5 {micro}m in size to contribute mainly to the current atmospheric pollution. Although at least 90% of dust are retained on the filters, the amounts of the respirable smaller particles are significantly larger in the current emission. The average chemical speciation was found to be analogous for the dust samples collected before and after the filters. The scanning electron microscopy associated with energy-dispersive X-ray analysis and Raman microspectrometry established the morphology and chemical composition at the level of individual particles. A lot of minor compounds were found as small heterogeneous individual particles in the heterogeneous particles of grilling dust. Among the homogeneous particles of furnace dust, amorphous C, {beta}-PbO, PbO-PbCl{sub 2}, FeO, CdS, CdSO{sub 4} were often detected as homogeneous mixtures with the major compounds within the particles.

Sobanska, S.; Ricq, N. [Ecole des Mines de Douai (France). Dept. Chimie et Environnement] [Ecole des Mines de Douai (France). Dept. Chimie et Environnement; [Univ. de Lille I, Villeneuve d`Ascq (France); Laboudigue, A.; Guillermo, R. [Ecole des Mines de Douai (France). Dept. Chimie et Environnement] [Ecole des Mines de Douai (France). Dept. Chimie et Environnement; Bremard, C.; Laureyns, J.; Merlin, J.C.; Wignacourt, J.P. [Univ. de Lille I, Villeneuve d`Ascq (France)] [Univ. de Lille I, Villeneuve d`Ascq (France)

1999-05-01T23:59:59.000Z

111

On vapor shielding of dust grains of iron, molybdenum, and tungsten in fusion plasmas  

SciTech Connect (OSTI)

The shielding effects of ablation cloud around a small dust grain composed of iron, molybdenum, or tungsten in fusion plasmas are considered. These include collisional dissipation of momentum flux of impinging plasma ions, heat transfer by secondary plasma created due to electron impact ionization of the ablated atoms, and radiative plasma power losses in the ablation cloud. The maximum radius, which limits applicability of existing dust-plasma interaction models neglecting the cloud shielding effects, for dust grains of the considered high-Z metals is calculated as function of plasma parameters. The thermal bifurcation triggered by thermionic electron emission from dust grains, observed for some of the considered materials, is analyzed. The results are compared with previous calculations for dust composed of low-Z fusion related materials, i.e., lithium, beryllium, and carbon.

Brown, B. T.; Smirnov, R. D., E-mail: rsmirnov@ucsd.edu; Krasheninnikov, S. I. [Department of Mechanical and Aerospace Engineering, University of California, San Diego, 9500 Gilman Dr., La Jolla, California 92093-0411 (United States)] [Department of Mechanical and Aerospace Engineering, University of California, San Diego, 9500 Gilman Dr., La Jolla, California 92093-0411 (United States)

2014-02-15T23:59:59.000Z

112

Iron Speciation in Urban Dust  

SciTech Connect (OSTI)

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

E Elzinga; Y Gao; J Fitts; R Tappero

2011-12-31T23:59:59.000Z

113

Phase-resolved optical emission of dusty rf discharges: Experiment and simulation  

SciTech Connect (OSTI)

The spectral emission of atoms in a dusty radio frequence (rf) discharge plasma in argon and helium has been measured with a gated ICCD camera. The spatially and temporally resolved emission/excitation of the argon and helium atoms during the rf cycle in the dusty discharge was compared to the dust-free case. In the bulk plasma above the dust cloud, the emission is clearly enhanced in the dusty discharge with respect to the pure discharge, whereas in the sheath the emission is reduced. In addition, the emission of a dusty argon plasma is studied via particle-particle particle-mesh (P{sup 3}M) simulations. The rf dynamics with a single dust particle trapped in the sheath was calculated. Like in the experiment the dust modifies the atomic emission. The spatiotemporal excitation pattern of the experiment is reproduced and a detailed understanding of the difference in excitation of the discharge with and without dust is presented.

Melzer, Andre; Huebner, Simon; Lewerentz, Lars; Schneider, Ralf [Institut fuer Physik, Ernst-Moritz-Arndt-Universiaet, D-17489 Greifswald (Germany); Matyash, Konstantin [Max-Planck Institut fuer Plasmaphysik, EURATOM Association, D-17491 Greifswald (Germany); Ikkurthi, Ramana [Institute for Plasma Research, Bhat, Ghandinagar, Gujarat (India)

2011-03-15T23:59:59.000Z

114

Eight-year Climatology of Dust Optical Depth on Mars  

E-Print Network [OSTI]

We have produced a multiannual climatology of airborne dust from Martian year 24 to 31 using multiple datasets of retrieved or estimated column optical depths. The datasets are based on observations of the Martian atmosphere from April 1999 to July 2013 made by different orbiting instruments: the Thermal Emission Spectrometer (TES) aboard Mars Global Surveyor, the Thermal Emission Imaging System (THEMIS) aboard Mars Odyssey, and the Mars Climate Sounder (MCS) aboard Mars Reconnaissance Orbiter (MRO). The procedure we have adopted consists of gridding the available retrievals of column dust optical depth (CDOD) from TES and THEMIS nadir observations, as well as the estimates of this quantity from MCS limb observations. Our gridding method calculates averages and uncertainties on a regularly spaced, but possibly incomplete, spatio-temporal grid, using an iterative procedure weighted in space, time, and retrieval uncertainty. In order to evaluate strengths and weaknesses of the resulting gridded maps, we validat...

Montabone, L; Millour, E; Wilson, R J; Lewis, S R; Cantor, B A; Kass, D; Kleinboehl, A; Lemmon, M; Smith, M D; Wolff, M J

2014-01-01T23:59:59.000Z

115

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

SciTech Connect (OSTI)

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

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

2013-10-10T23:59:59.000Z

116

A Search for Extraplanar Dust in Nearby Edge-On Spirals  

E-Print Network [OSTI]

We present high resolution BV images of 12 edge-on spiral galaxies observed with the WIYN 3.5-m telescope. These images were obtained to search for extraplanar (|z| > 0.4 kpc) absorbing dust structures similar to those previously found in NGC 891 (Howk & Savage 1997). Our imaged galaxies include a sample of seven massive L_*-like spiral galaxies within D 87 deg from the plane of the sky. We find that five of these seven systems show extraplanar dust, visible as highly-structured absorbing clouds against the background stellar light of the galaxies. The more prominent structures are estimated to have associated gas masses >10^5 M_sun; the implied potential energies are > 10^(52) ergs. All of the galaxies in our sample that show detectable halpha emission at large z also show extraplanar dust structures. None of those galaxies for which extraplanar halpha searches were negative show evidence for extensive high-z dust. The existence of extraplanar dust is a common property of massive spiral galaxies. We discuss several mechanisms for shaping the observed dust features, emphasizing the possibility that these dusty clouds represent the dense phase of a multiphase medium at high-z in spiral galaxies. The correlation between high-z dust and extraplanar Halpha emission may simply suggest that both trace the high-z interstellar medium in its various forms (or phases), the existence of which may ultimately be driven by vigorous star formation in the underlying disk. (Abstract abridged)

J. Christopher Howk; Blair D. Savage

1999-02-04T23:59:59.000Z

117

DUST HEATING SOURCES IN GALAXIES: THE CASE OF M33 (HERM33ES)  

SciTech Connect (OSTI)

Dust emission is one of the main windows to the physics of galaxies and to star formation as the radiation from young, hot stars is absorbed by the dust and reemitted at longer wavelengths. The recently launched Herschel satellite now provides a view of dust emission in the far-infrared at an unequaled resolution and quality up to 500 {mu}m. In the context of the Herschel HERM33ES open time key project, we are studying the moderately inclined Scd local group galaxy M33 which is located only 840 kpc away. In this article, using Spitzer and Herschel data ranging from 3.6 {mu}m to 500 {mu}m, along with H I, H{alpha} maps, and Galaxy Evolution Explorer ultraviolet data, we have studied the emission of the dust at the high spatial resolution of 150 pc. Combining Spitzer and Herschel bands, we have provided new, inclination-corrected, resolved estimators of the total infrared brightness and of the star formation rate from any combination of these bands. The study of the colors of the warm and cold dust populations shows that the temperature of the former is, at high brightness, dictated by young massive stars but, at lower brightness, heating is taken over by the evolved populations. Conversely, the temperature of the cold dust is tightly driven by the evolved stellar populations.

Boquien, M.; Calzetti, D. [Department of Astronomy, University of Massachusetts, LGRT-B 619E, Amherst, MA 01003 (United States); Combes, F. [Observatoire de Paris, LERMA, 75014 Paris (France); Henkel, C. [Max-Planck-Institut fuer Radioastronomie, 53121 Bonn (Germany); Israel, F.; Van der Werf, P. [Leiden Observatory, Leiden University, NL 2300 RA Leiden (Netherlands); Kramer, C. [Instituto Radioastronomia Milimetrica, Nucleo Central, E-18012 Spain (Spain); Relano, M.; Verley, S. [Dept. Fisica Teorica y del Cosmos, Universidad de Granada, Granada (Spain); Xilouris, E. M., E-mail: mederic.boquien@oamp.fr [Institute of Astronomy and Astrophysics, National Observatory of Athens, P. Penteli, 15236 Athens (Greece)

2011-10-15T23:59:59.000Z

118

Iron speciation in urban dust  

SciTech Connect (OSTI)

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

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

2011-08-01T23:59:59.000Z

119

On the Absorption and Emission Properties of Interstellar Grains  

E-Print Network [OSTI]

Our current understanding of the absorption and emission properties of interstellar grains are reviewed. The constraints placed by the Kramers-Kronig relation on the wavelength-dependence and the maximum allowable quantity of the dust absorption are discussed. Comparisons of the opacities (mass absorption coefficients) derived from interstellar dust models with those directly estimated from observations are presented.

Aigen Li

2005-03-25T23:59:59.000Z

120

Mineral Dust Entrainment and Deposition (DEAD) model: Description and 1990s dust climatology  

E-Print Network [OSTI]

DUST MODEL AND 1990S CLIMATOLOGY Table 5. Trace MetalDUST MODEL AND 1990S CLIMATOLOGY Figure 7. Predicted andDUST MODEL AND 1990S CLIMATOLOGY Mahowald, N. , K. Kohfeld,

Zender, Charles S; Bian, H.; Newman, D.

2003-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fugitive dust emissions" 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

Technology Reinvestment Program/Advanced ``Zero Emission'' Control Valve (Phase II)  

SciTech Connect (OSTI)

The objectives of this effort are to determine, develop and demonstrate the feasibility of significantly reducing the cost and expanding the applications for a family of Advanced Zero Emissions Control Valves that meets the fugitive emissions requirements of the 1990 Amendments to the Clean Air Act. This program is a direct technology spin-off from the valve technology that is critical to the US Navy's Nuclear Powered Fleet. These zero emissions valves will allow the Hydrocarbon and Chemical Processing Industries, etc., to maintain their competitiveness and still meet environmental and safety requirements. Phase 2 is directed at refining the basic technologies developed during Phase 1 so that they can be more readily selected and utilized by the target market. In addition to various necessary certifications, the project will develop a full featured digital controller with ``smart valve'' growth capability, expanding valve sizes/applications and identifying valve materials to permit applications in severe operational environments.

J. Napoleon

1998-12-01T23:59:59.000Z

122

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

SciTech Connect (OSTI)

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

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

2011-11-20T23:59:59.000Z

123

autogenous bone dust: Topics by E-print Network  

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

galaxies, a method for the dust mass evaluation, which accounts for the dust temperature distribution, is here presented and discussed. The derived dust masses turn out to...

124

DUST GRAIN EVOLUTION IN SPATIALLY RESOLVED T TAURI BINARIES  

SciTech Connect (OSTI)

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

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

2011-10-10T23:59:59.000Z

125

Glass Frit Clumping And Dusting  

SciTech Connect (OSTI)

DWPF mixes a slurry of glass frit (Frit 418) and dilute (1.5 wt%) formic acid solution with high level waste in the Slurry Mix Evaporator (SME). There would be advantages to introducing the frit in a non-slurry form to minimize water addition to the SME, however, adding completely dry frit has the potential to generate dust which could clog filters or condensers. Prior testing with another type of frit, Frit 320, and using a minimal amount of water reduced dust generation, however, the formation of hard clumps was observed. To examine options and behavior, a TTQAP [McCabe and Stone, 2013] was written to initiate tests that would address these concerns. Tests were conducted with four types of glass frit; Frit 320, DWPF Frit 418, Bekeson Frit 418 and Multi-Aspirator Frit 418. The last two frits are chemically identical to DWPF Frit 418 but smaller particles were removed by the respective vendors. Test results on Frit Clumping and Dusting are provided in this report. This report addresses the following seven questions. Short answers are provided below with more detailed answers to follow. 1. Will the addition of a small amount of water, 1.5 wt%, to dry DWPF Frit 418 greatly reduce the dust generation during handling at DWPF? a. Yes, a small scale test showed that adding a little water to the frit greatly reduced dust generation during handling. 2. Will the addition of small amounts of water to the frit cause clumping that will impair frit handling at DWPF? a. No, not with Frit 418. Although clumps were observed to form when 1.5 wt% water was mixed with DWPF Frit 418, then compressed and air-dried overnight, the clumps were easily crushed and did not form the hardened material noted when Frit 320 was tested. 3. What is the measured size distribution of dust generated when dry frit is handled? (This affects the feasibility and choice of processing equipment for removing the dust generating fraction of the frit before it is added to the SME.) a. The size distribution for the dust removed from fresh DWPF Frit 418 while it was being shaken in a small scale LabRAM test was measured. The median size on a volume basis was 7.6 ?m and 90% of the frit particles were between 1.6 and 28 ?m. The mass of dust collected using this test protocol was much less than 1% of the original frit. 4. Can the dust be removed in a small number of processing steps and without the larger frit particles continuing to spall additional dust sized particles? a. Test results using a LabRAM were inconclusive. The LaRAM performs less efficient particle size separation than the equipment used by Bekeson and Multi-Aspirator. 5. What particle size of frit is expected to create a dust problem? a. The original criterion for creating a dusting problem was those particle sizes that were readily suspended when being shaken. For that criterion calculations and Microtrac size analyses indicated that particles smaller than 37 ?m are likely dust generators. Subsequently a more sophisticated criterion for dust problem was considered, particle sizes that would become suspended in the air flow patterns inside the SME and possibly plug the condenser. That size may be larger than 37 ?m but has not yet been determined. 6. If particles smaller than 37 ?m are removed will bulk dust generation be eliminated? a. Video-taped tests were performed using three gallons each of three types of frit 418, DWPF frit, Bekeson frit and Multi-Aspirator frit. Frit was poured through air from a height of approximately eight feet into a container half filled with water. Pouring Bekeson frit or Multi-Aspirator frit generated markedly less visible dust, but there was still a significant amount, which still has the potential of causing a dust problem. 7. Can completely dry frit be poured into the SME without having dust plug the condenser at the top of the vessel? a. Because of the complexity of air currents inside the SME and the difficulty of defensible size scaling a more prototypical test will be required to answer this question. We recommend construction of a full scale

Steimke, J. L.

2013-09-26T23:59:59.000Z

126

Development and application of a real time lead-in-air analyzer in controlling lead exposure at a primary lead smelter  

SciTech Connect (OSTI)

To assist in locating and quantifying fugitive emissions in a primary lead smelter, a real time lead-in-air analyzer has been developed. Dust is collected on paper tape filters and the lead analyzed by X-ray fluorescence. The unit has been used successfully to assist in the implementation of an engineering control monitoring program.

Smith, W.J.; Dekker, D.L.; Greenwood-Smith, R.

1986-12-01T23:59:59.000Z

127

The dust, planetesimals and planets of HD 38529  

E-Print Network [OSTI]

HD 38529 is a post-main sequence G8III/IV star (3.5 Gyr old) with a planetary system consisting of at least two planets having Msin(i) of 0.8 MJup and 12.2 MJup, semimajor axes of 0.13 AU and 3.74 AU, and eccentricities of 0.25 and 0.35, respectively. Spitzer observations show that HD 38529 has an excess emission above the stellar photosphere, with a signal-to-noise ratio (S/N) at 70 micron of 4.7, a small excess at 33 micron (S/N=2.6) and no excess model the spectral energy distribution of HD 38529 to find out which of these niches show signs of harboring dust-producing plantesimals. The secular analysis, together with the SED modeling resuls, suggest that the planetesimals responsible for most of the dust emission are likely located within 20-50 AU, a configuration that resembles that of the Jovian planets + Kuiper Belt in our Solar System. Finally, we place upper limits (8E-6 lunar masses of 10 micron particles) to the amount of dust that could be located in the dynamically stable region that exists between the two planets (0.25--0.75 AU).

Amaya Moro-Martin; Renu Malhotra; John M. Carpenter; Lynne A. Hillenbrand; Sebastian Wolf; Michael R. Meyer; David Hollenbach; Joan Najita; Thomas Henning

2007-06-22T23:59:59.000Z

128

Coal cutting research slashes dust  

SciTech Connect (OSTI)

US Bureau of Mines' research projects aimed at the reduction of coal dust during coal cutting operations are described. These include an investigation of the effects of conical bit wear on respirable dust generation, energy and cutting forces; the determination of the best conical bit mount condition to increase life by enhancing bit rotation; a comparison between chisel- and conical-type cutters. In order to establish a suitable homogeneous reference material for cutting experiments, a synthetic coal with a plaster base is being developed.

Roepke, W.W.

1983-10-01T23:59:59.000Z

129

Nonlinear dust acoustic waves and shocks  

SciTech Connect (OSTI)

We describe experiments on (1) nonlinear dust acoustic waves and (2) dust acoustic shocks performed in a direct current (DC) glow discharge dusty plasma. First, we describe experiments showing nonlinear dust acoustic waves characterized by waveforms of the dust density that are typically sharper in the wave crests and flatter in the wave troughs (compared to sinusoidal waves), indicating the development of wave harmonics. We discuss this behavior in terms of a second-order fluid theory for dust acoustic waves. Second, experimental observations of the propagation and steepening of large-amplitude dust acoustic waves into dust acoustic shock waves are presented. The observed shock wave evolution is compared with numerical calculations based on the Riemann solution of the fully nonlinear fluid equations for dust acoustic waves.

Merlino, R. L.; Heinrich, J. R.; Hyun, S.-H.; Meyer, J. K. [Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242 (United States)

2012-05-15T23:59:59.000Z

130

Using Reconstructed Dust Climatology to Study the Impacts of Martian Dust Storms on Dynamics  

E-Print Network [OSTI]

Using Reconstructed Dust Climatology to Study the Impacts of Martian Dust Storms on Dynamics L@atm.ox.ac.uk) Abstract We have reconstructed the climatology of the dust on Mars using available retrievals and estimates) a reconstruction of the dust optical depth climatology based on weighted gridding for Martian years 24

Cambridge, University of

131

EFFECT OF COAL DUST ONEFFECT OF COAL DUST ON RAILROAD BALLAST STRENGTHRAILROAD BALLAST STRENGTH  

E-Print Network [OSTI]

Triaxial TestsTests Direct Shear TestsDirect Shear Tests Clean and Coal Dust Fouled Ballast BehaviorClean1 EFFECT OF COAL DUST ONEFFECT OF COAL DUST ON RAILROAD BALLAST STRENGTHRAILROAD BALLAST STRENGTH for Laboratory StudyFouling Mechanism / Need for Laboratory Study Mechanical Properties of Coal Dust

Barkan, Christopher P.L.

132

Adding coal dust to coal batch  

SciTech Connect (OSTI)

The granulometric composition of coke dust from the dry-slaking machine is determined. The influence of additions of 3-7% coke dust on the quality of industrial coking batch and the coke obtained by box coking is estimated. Adding 1% coke dust to coking batch does not markedly change the coke quality. Industrial equipment for the supply of dry-slaking dust to the batch is described.

V.S. Shved; A.V.Berezin [OAO Koks, Kemerovo (Russian Federation)

2009-05-15T23:59:59.000Z

133

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

E-Print Network [OSTI]

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

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

2015-01-01T23:59:59.000Z

134

Characterization of jovian plasma embedded dust particles  

E-Print Network [OSTI]

As the data from space missions and laboratories improve, a research domain combining plasmas and charged dust is gaining in prominence. Our solar system provides many natural laboratories such as planetary rings, comet comae and tails, ejecta clouds around moons and asteroids, and Earth's noctilucent clouds for which to closely study plasma-embedded cosmic dust. One natural laboratory to study electromagnetically-controlled cosmic dust has been provided by the Jovian dust streams and the data from the instruments which were on board the Galileo spacecraft. Given the prodigious quantity of dust poured into the Jovian magnetosphere by Io and its volcanoes resulting in the dust streams, the possibility of dusty plasma conditions exist. This paper characterizes the main parameters for those interested in studying dust embedded in a plasma with a focus on the Jupiter environment. I show how to distinguish between dust-in-plasma and dusty-plasma and how the Havnes parameter P can be used to support or negate the possibility of collective behavior of the dusty plasma. The result of applying these tools to the Jovian dust streams reveals mostly dust-in-plasma behavior. In the orbits displaying the highest dust stream fluxes, portions of orbits E4, G7, G8, C21 satisfy the minimum requirements for a dusty plasma. However, the P parameter demonstrates that these mild dusty plasma conditions do not lead to collective behavior of the dust stream particles.

Amara L. Graps

2006-09-12T23:59:59.000Z

135

Atmospheric controls on the annual cycle of North African dust Sebastian Engelstaedter1  

E-Print Network [OSTI]

and central Chad. Dust emissions from these sources follow a distinct seasonal cycle. Whereas our., 2000; Andreae et al., 2005; Kaufman et al., 2002] by scattering and absorbing incoming solar radiation the American coast [Shinn et al., 2000; Walsh and Steidinger, 2001] and in Puerto Rico [Stallard, 2001], may

Washington, Richard

136

ORIGIN OF DUST AROUND V1309 SCO  

SciTech Connect (OSTI)

The origin of dust grains in the interstellar medium is still an unanswered problem. Nicholls et al. found the presence of a significant amount of dust around V1309 Sco, which may originate from the merger of a contact binary. We investigate the origin of dust around V1309 Sco and suggest that these dust grains are produced in the binary-merger ejecta. By means of the AGBDUST code, we estimate that ?5.2 × 10{sup –4} M{sub ?} dust grains are produced with a radii of ?10{sup –5} cm. These dust grains are mainly composed of silicate and iron grains. Because the mass of the binary merger ejecta is very small, the contribution of dust produced by binary merger ejecta to the overall dust production in the interstellar medium is negligible. However, it is important to note that the discovery of a significant amount of dust around V1309 Sco offers a direct support for the idea that common-envelope ejecta provides an ideal environment for dust formation and growth. Therefore, we confirm that common envelope ejecta can be important source of cosmic dust.

Zhu, Chunhua; Lü, Guoliang; Wang, Zhaojun, E-mail: guolianglv@gmail.com [School of Physical Science and Technology, Xinjiang University, Urumqi, 830046 (China)

2013-11-01T23:59:59.000Z

137

A novel aspect of dust in plasma  

SciTech Connect (OSTI)

Nonlinear screening of the dust grains immersed in a homogenous fully ionized electron-ion plasma is investigated. Assuming conservation of entropy, an important relation is obtained between the maximum potential (and therefore the charge) of the dust grain and the temperature of the electrons. The Thomas-Fermi equation is derived for the potential of a dust grain in a nondegenerate plasma suggesting the existence of dust atom with a well defined atomic radius. Furthermore, based on the Born-Oppenheimer approximation, the notion of a dust-grain molecule is introduced in which the protons act like a kind of 'glue' which binds two negatively charged dust grains together, and the motion of the grains have little influence on that binding force. Finally, considering the weak interaction between the proton clouds of two dust grains, an expression of exchange energy is obtained.

Tsintsadze, N.L.; Murtaza, G.; Ehsan, Z. [Department of Plasma Physics, Tbilisi State University (Georgia); National Centre for Mathematics and Salam Chair in Physics, G.C. University Lahore, 54000 (Pakistan); National Centre for Mathematics and Salam Chair in Physics, G.C. University Lahore, 54000 (Pakistan)

2006-02-15T23:59:59.000Z

138

THE REINCARNATION OF INTERSTELLAR DUST: THE IMPORTANCE OF ORGANIC REFRACTORY MATERIAL IN INFRARED SPECTRA OF COMETARY COMAE AND CIRCUMSTELLAR DISKS  

SciTech Connect (OSTI)

We consider the reincarnation of interstellar dust to be reborn in protoplanetary disks as aggregates consisting of submicron-sized grains with a crystalline or amorphous silicate core and an organic-rich carbonaceous mantle. We find that infrared spectra of reincarnated interstellar dust reproduce emission peaks at correct wavelengths where the peaks were observed in cometary comae, debris disks, and protoplanetary disks if the volume fraction of organic refractory meets the constraints on elemental abundances. We discuss what we can learn from the infrared spectra of reincarnated interstellar dust in cometary comae and circumstellar disks.

Kimura, Hiroshi, E-mail: hiroshi_kimura@cps-jp.org [Graduate School of Science, Kobe University, c/o CPS (Center for Planetary Science), Chuo-ku Minatojima Minamimachi 7-1-48, Kobe 650-0047 (Japan)] [Graduate School of Science, Kobe University, c/o CPS (Center for Planetary Science), Chuo-ku Minatojima Minamimachi 7-1-48, Kobe 650-0047 (Japan)

2013-09-20T23:59:59.000Z

139

anomalous dust emission: Topics by E-print Network  

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

leq 4times10-3. We observe that the duststellar ratios depend on the interstellar medium (ISM) environment, such as the distance from currently or previously star-forming...

140

Influence of dust on the emissivity of radiant barriers  

E-Print Network [OSTI]

beloved children Anita Maria and Felipe Homero, and my family in Ecuador. The support and love of my mother and father, and my family-in-law were vital to overcome the difficulties. I would like to mention my sister in law Luly for her special attention... To My Beloved Father To Anita Maria and Fehpe Homero TABLE OF CONTENTS ABSTRACT Page ACKNOWLEDGMENTS DEDICATION V 1 1 LIST OF FIGURES Xl NOMENCLATURE . X111 1. INTRODUCTION 2. LITERATURE REVIEW 3. TOPICS ON RADIANT BARRIERS PERFORMANCE 3. 1...

Noboa, Homero Luis

1991-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fugitive dust emissions" 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

Coal cutting research slashes dust  

SciTech Connect (OSTI)

The Coal-Cutting Technology Group at the Bureau of Mine's Twin Cities Research Center is investigating ways to reduce primary dust generated by coal cutting. The progression of research within the program is from fundamental laboratory research, to fundamental field research, to field concept verification. Then the Bureau recommends warranted changes and/or prototype development to industry. Currently the Cutting Technology Group has several projects in each phase of research. The Bureau's current fundamental studies of bit characteristics are directed to determining the effects of conical bit wear on primary respirable dust generation, energy, and cutting forces; establishing best conical bit mount condition to increase life by enhancing bit rotation; and comparing chisel-type cutters to conical-type cutters. Additionally, to establish a suitable homogeneous reference material for cutting experiments, a synthetic coal with a plaster base is being developed.

Roepke, W.W.

1983-10-01T23:59:59.000Z

142

Coal cutting research slashes dust  

SciTech Connect (OSTI)

The Coal-Cutting Technology Group at the Bureau of Mines Twin Cities (MN) Research Center is investigating ways to reduce primary dust generated by coal cutting. The progression of research within the program is from fundamental laboratory research, to fundamental field research, to field concept verification. Then the Bureau recommends warranted changes and/or prototype development to industry. Currently the group has several projects in each phase of research. The Bureau's current fundamental studies of bit characteristics are directed toward determining the effects of conical bit wear on primary respirable dust generation, energy, and cutting forces; establishing best conical bit mount condition to increase life by enhancing bit rotation; and comparing chisel-type cutters to conical-type cutters. Additionally, to establish a suitable homogeneous reference material for cutting experiments, a synthetic coal with a plaster base is being developed.

Roepke, W.W.

1983-10-01T23:59:59.000Z

143

Silicate emissions in active galaxies - From LINERs to QSOs  

E-Print Network [OSTI]

We report the first detection of ~10 and ~18 micron silicate dust emissions in a low-luminosity active galactic nucleus (AGN), obtained in Spitzer-IRS 7-37 micron spectroscopy of the Type 1 LINER galaxy NGC3998. Silicate emissions in AGN have only recently been detected in several quasars. Our detection counters suggestions that silicate emissions are present only in the most luminous AGN. The silicate features may be signatures of a dusty ``obscuring torus'' viewed face-on as postulated for Type 1 AGN. However, the apparently cool (~200 K) dust is inconsistent with theoretical expectations of much hotter torus walls. Furthermore, not all Type 1 objects are silicate emission sources. Alternatively, the silicate emission may originate in dust not directly associated with a torus. We find that the long-wavelength (>20 micron) tail of the emission in NGC3998 is significantly weaker than in the sample of bright QSOs recently presented by Hao et al. The 10 micron profile in our NGC3998 spectrum is inconsistent with ``standard'' silicate ISM dust. This may indicate differences in the dust composition, grain size distribution, or degree of crystallization. The differences between NGC3998, QSOs, and Galactic templates suggest that there are significant environmental variations.

E. Sturm; M. Schweitzer; D. Lutz; A. Contursi; R. Genzel; M. D. Lehnert; L. J. Tacconi; S. Veilleux; D. S. Rupke; D. -C. Kim; A. Sternberg; D. Maoz; S. Lord; J. Mazzarella; D. B. Sanders

2005-06-29T23:59:59.000Z

144

Optical Emission of Dusty RF Discharges: Experiment and Simulation  

SciTech Connect (OSTI)

The spectral emission of argon atoms in a dusty radio frequence (RF) discharge has been investigated experimentally and in simulations. It was observed that the spatially and temporally resolved emission of the argon atoms in the dusty discharge was increased compared to the dust-free case during sheath expansion. The corresponding simulations have revealed that the dust trapped in the sheath of the discharge leads to a small, but important, increase of the amount of high-energy electrons that in turn leads to an increased argon emission.

Melzer, A.; Lewerentz, L.; Schneider, R. [Institute of Physics, University Greifswald, Felix-Hausdorff-Str. 6, 17489 Greifswald (Germany); Huebner, S. [Institute of Physics, University Greifswald, Felix-Hausdorff-Str. 6, 17489 Greifswald (Germany); Department of Applied Physics, Technical University Eindhoven, NL-5600 MB Eindhoven (Netherlands); Matyash, K. [Max-Planck-Institute for Plasma Physics, EURATOM Association, D-17491 Greifswald (Germany); Ikkurthi, V. R. [Institute for Plasma Research, Bhat, Ghandinagar, Gujarat (India)

2011-11-29T23:59:59.000Z

145

DUST-TO-GAS RATIO IN THE EXTREMELY METAL-POOR GALAXY I Zw 18  

SciTech Connect (OSTI)

The blue compact dwarf galaxy I Zw 18 is one of the most metal-poor systems known in the local universe (12+log(O/H) = 7.17). In this work we study I Zw 18 using data from Spitzer, Herschel Space Telescope, and IRAM Plateau de Bure Interferometer. Our data set includes the most sensitive maps of I Zw 18, to date, in both the far-infrared and the CO J = 1 {yields} 0 transition. We use dust emission models to derive a dust mass upper limit of only M{sub dust} {<=} 1.1 Multiplication-Sign 10{sup 4} M{sub Sun} (3{sigma} limit). This upper limit is driven by the non-detection at 160 {mu}m, and it is a factor of 4-10 times smaller than previous estimates (depending on the model used). We also estimate an upper limit to the total dust-to-gas mass ratio of M{sub Dust}/M{sub gas} {<=} 5.0 Multiplication-Sign 10{sup -5}. If a linear correlation between the dust-to-gas mass ratio and metallicity (measured as O/H) were to hold, we would expect a ratio of 3.9 Multiplication-Sign 10{sup -4}. We also show that the infrared spectral energy distribution is similar to that of starbursting systems.

Herrera-Camus, Rodrigo; Fisher, David B.; Bolatto, Alberto D. [Department of Astronomy and Laboratory of Millimeter Astronomy, University of Maryland, College Park, MD 20742 (United States); Leroy, Adam K. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903-2475 (United States); Walter, Fabian [Max-Planck-Institut fuer Astronomie, Konigstuehl 17, D-69117 Heidelberg (Germany); Gordon, Karl D.; Roman-Duval, Julia [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Donaldson, Jessica; Melendez, Marcio [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Cannon, John M. [Department of Physics and Astronomy, Macalester College, 1600 Grand Avenue, Saint Paul, MN 55105 (United States)

2012-06-20T23:59:59.000Z

146

Correlations of atmospheric water ice and dust in the Martian Polar regions  

E-Print Network [OSTI]

We report on the interannual variability of the atmospheric ice/dust cycle in the Martian polar regions for Mars Years 28-30. We used CRISM emission phase function measurements to derive atmospheric dust optical depths and data from the MARCI instrument to derive atmospheric water ice optical depths. We have used autocorrelation and cross correlation functions in order to quantify the degree to which dust and ice are correlated throughout both polar regions during Mars Years 28-29. We find that in the south polar region, dust has the tendency to "self clear", demonstrated by negative autocorrelation around the central peak. This does not occur in the north polar region. In the south polar region, dust and ice are temporally and spatially anti correlated. In the north polar region, this relationship is reversed, however temporal correlation of northern dust and ice clouds is weak - 6 times weaker than the anticorrelation in the south polar region. Our latitudinal autocorrelation functions allow us to put avera...

Brown, Adrian J; Scargle, Jeffrey D

2015-01-01T23:59:59.000Z

147

DUST IN A TYPE Ia SUPERNOVA PROGENITOR: SPITZER SPECTROSCOPY OF KEPLER'S SUPERNOVA REMNANT  

SciTech Connect (OSTI)

Characterization of the relatively poorly understood progenitor systems of Type Ia supernovae is of great importance in astrophysics, particularly given the important cosmological role that these supernovae play. Kepler's supernova remnant, the result of a Type Ia supernova, shows evidence for an interaction with a dense circumstellar medium (CSM), suggesting a single-degenerate progenitor system. We present 7.5-38 {mu}m infrared (IR) spectra of the remnant, obtained with the Spitzer Space Telescope, dominated by emission from warm dust. Broad spectral features at 10 and 18 {mu}m, consistent with various silicate particles, are seen throughout. These silicates were likely formed in the stellar outflow from the progenitor system during the asymptotic giant branch stage of evolution, and imply an oxygen-rich chemistry. In addition to silicate dust, a second component, possibly carbonaceous dust, is necessary to account for the short-wavelength Infrared Spectrograph and Infrared Array Camera data. This could imply a mixed chemistry in the atmosphere of the progenitor system. However, non-spherical metallic iron inclusions within silicate grains provide an alternative solution. Models of collisionally heated dust emission from fast shocks (>1000 km s{sup -1}) propagating into the CSM can reproduce the majority of the emission associated with non-radiative filaments, where dust temperatures are {approx}80-100 K, but fail to account for the highest temperatures detected, in excess of 150 K. We find that slower shocks (a few hundred km s{sup -1}) into moderate density material (n{sub 0} {approx} 50-250 cm{sup -3}) are the only viable source of heating for this hottest dust. We confirm the finding of an overall density gradient, with densities in the north being an order of magnitude greater than those in the south.

Williams, Brian J.; Borkowski, Kazimierz J.; Reynolds, Stephen P. [Physics Department, North Carolina State University, Raleigh, NC 27695-8202 (United States); Ghavamian, Parviz [Department of Physics, Astronomy, and Geosciences, Towson University, Towson, MD 21252 (United States); Blair, William P. [Department of Physics and Astronomy, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218-2686 (United States); Long, Knox S. [STScI, 3700 San Martin Dr., Baltimore, MD 21218 (United States); Sankrit, Ravi, E-mail: brian.j.williams@nasa.gov [SOFIA/USRA, NASA Ames Research Center, M/S N211-3, Moffett Field, CA 94035 (United States)

2012-08-10T23:59:59.000Z

148

A COOL DUST FACTORY IN THE CRAB NEBULA: A HERSCHEL STUDY OF THE FILAMENTS  

SciTech Connect (OSTI)

Whether supernovae are major sources of dust in galaxies is a long-standing debate. We present infrared and submillimeter photometry and spectroscopy from the Herschel Space Observatory of the Crab Nebula between 51 and 670 {mu}m as part of the Mass Loss from Evolved StarS program. We compare the emission detected with Herschel with multiwavelength data including millimeter, radio, mid-infrared, and archive optical images. We carefully remove the synchrotron component using the Herschel and Planck fluxes measured in the same epoch. The contribution from line emission is removed using Herschel spectroscopy combined with Infrared Space Observatory archive data. Several forbidden lines of carbon, oxygen, and nitrogen are detected where multiple velocity components are resolved, deduced to be from the nitrogen-depleted, carbon-rich ejecta. No spectral lines are detected in the SPIRE wavebands; in the PACS bands, the line contribution is 5% and 10% at 70 and 100 {mu}m and negligible at 160 {mu}m. After subtracting the synchrotron and line emission, the remaining far-infrared continuum can be fit with two dust components. Assuming standard interstellar silicates, the mass of the cooler component is 0.24{sup +0.32} {sub -0.08} M {sub Sun} for T = 28.1{sup +5.5} {sub -3.2} K. Amorphous carbon grains require 0.11 {+-} 0.01 M {sub Sun} of dust with T = 33.8{sup +2.3} {sub -1.8} K. A single temperature modified blackbody with 0.14 M {sub Sun} and 0.08 M {sub Sun} for silicate and carbon dust, respectively, provides an adequate fit to the far-infrared region of the spectral energy distribution but is a poor fit at 24-500 {mu}m. The Crab Nebula has condensed most of the relevant refractory elements into dust, suggesting the formation of dust in core-collapse supernova ejecta is efficient.

Gomez, H. L.; Clark, C. J. R.; Gomez, E. L.; Gear, W. K. [School of Physics and Astronomy, Cardiff University, The Parade, Cardiff CF24 3AA (United Kingdom); Krause, O.; Besel, M.-A.; Bouwman, J.; Henning, Th. [Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany); Barlow, M. J.; Swinyard, B. M.; Owen, P. J.; Matsuura, M. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Rho, J. [SOFIA Science Center, Universities Space Research Association, NASA Ames Research Center, MS 232, Moffett Field, CA 94035 (United States); Ivison, R. J.; Sibthorpe, B. [UK Astronomy Technology Centre, Royal Observatory Edinburgh, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Polehampton, E. T. [Space Science and Technology Department, Rutherford Appleton Laboratory, Oxfordshire, OX11 0QX (United Kingdom)

2012-11-20T23:59:59.000Z

149

Contribution of vehicle emissions to ambient carbonaceous particulate matter: A review and synthesis of the available data in the South Coast Air Basin. Final report  

SciTech Connect (OSTI)

Table of Contents: Executive Summary; Introduction; Ambient Carbonaceous Particulate Matter in the South Coast Air Basin; Measurements of Emissions from In-Use Motor Vehicles in the South Coast Air Basin; Integration of Emissions Measurements into Comprehensive Emissions Inventories; Relating Emissions fom Motor Vehicles to Particulate Air Quality; Synthesis: The Combined Effect of All Vehicle-Related Source Contributions Acting Together; Trends in More Recent Years; Opportunities for Further Research; References; Appendix A: Detailed Mass Emissions Rates for Organic Compounds from Motor Vehicle Exhaust; and Appendix B: Organic Compounds Emitted from Tire Dust, Paved Road Dust, and Brake Lining Wear Dust.

Cass, G.R.

1997-02-01T23:59:59.000Z

150

Optical Properties of Saharan Dust and Asian Dust: Application to Radiative Transfer Simulations  

E-Print Network [OSTI]

Because the bulk optical properties of dust are largely dependent on their chemical composition, published reports from numerous dust field studies enabled us to compile observation data sets to derive the effective complex refractive indices...

Fang, Guangyang

2012-07-16T23:59:59.000Z

151

SYSTEMATIC BLUESHIFT OF LINE PROFILES IN THE TYPE IIn SUPERNOVA 2010jl: EVIDENCE FOR POST-SHOCK DUST FORMATION?  

SciTech Connect (OSTI)

Type IIn supernovae (SNe) show spectral evidence for strong interaction between their blast wave and dense circumstellar material (CSM) around the progenitor star. SN 2010jl was the brightest core-collapse supernova in 2010, and it was a Type IIn explosion with strong CSM interaction. Andrews et al. recently reported evidence for an infrared (IR) excess in SN 2010jl, indicating either new dust formation or the heating of CSM dust in an IR echo. Here we report multi-epoch spectra of SN 2010jl that reveal the tell-tale signature of new dust formation: emission-line profiles becoming systematically more blueshifted as the red side of the line is blocked by increasing extinction. The effect is seen clearly in the intermediate-width (400-4000 km s{sup -1}) component of H{alpha} beginning roughly 30 days after explosion. Moreover, we present near-IR spectra demonstrating that the asymmetry in the hydrogen-line profiles is wavelength dependent, appearing more pronounced at shorter wavelengths. This evidence suggests that new dust grains had formed quickly in the post-shock shell of SN 2010jl arising from CSM interaction. Since the observed dust temperature has been attributed to an IR echo and not to new dust, either (1) IR excess emission at {lambda} < 5 {mu}m is not a particularly sensitive tracer of new dust formation in SNe, or (2) some assumptions about expected dust temperatures might require further study. Lastly, we discuss one possible mechanism other than dust that might lead to increasingly blueshifted line profiles in SNe IIn, although the wavelength dependence of the asymmetry argues against this hypothesis in the case of SN 2010jl.

Smith, Nathan; Bian, Fuyan; Weiner, Benjamin J. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Silverman, Jeffrey M.; Filippenko, Alexei V. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Cooper, Michael C. [Department of Physics and Astronomy, University of California, 4129 Frederick Reines Hall, Irvine, CA 92697-4575 (United States); Matheson, Thomas [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719-4933 (United States); Comerford, Julia M., E-mail: nathans@as.arizona.edu [Astronomy Department, University of Texas, Austin, TX 78712 (United States)

2012-01-15T23:59:59.000Z

152

The unusual silicate dust around HV 2310, an evolved star in the LMC  

E-Print Network [OSTI]

The spectrum of HV 2310, an evolved star in the Large Magellanic Cloud, taken with the Infrared Spectrograph (IRS) on the Spitzer Space Telescope reveals the presence of an optically thin shell of silicate dust with unusual spectral structure in the 10 um feature, with an emission peak at 9.7 um, a saddle at 10.4 um, and an extended shoulder to 11.2 um. This structure is similar to spectra from crystalline silicate grains, and of the available optical constants, forsterite provides the best fit. The spectrum also shows structure at 14 um which may arise from an unidentified dust feature.

G. C. Sloan; D. Devost; J. Bernard-Salas; P. R. Wood; J. R. Houck

2005-09-15T23:59:59.000Z

153

asian sand dust: Topics by E-print Network  

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

that trigger dust storms, and the lifting of dust by dust devils and other small-scale vortices. We also discuss the physics of wind-blown sand and dune formation on Venus...

154

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

SciTech Connect (OSTI)

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

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

2012-07-15T23:59:59.000Z

155

The SCUBA Local Universe Galaxy Survey II. 450 micron data - evidence for cold dust in bright IRAS Galaxies  

E-Print Network [OSTI]

This is the second in a series of papers presenting results from the SCUBA Local Universe Galaxy Survey. In our first paper we provided 850 micron flux densities for 104 galaxies selected from the IRAS Bright Galaxy Sample and we found that the 60, 100 micron (IRAS) and 850 micron (SCUBA) fluxes could be adequately fitted by emission from dust at a single temperature. In this paper we present 450 micron data for the galaxies. With the new data, the spectral energy distributions of the galaxies can no longer be fitted with an isothermal dust model - two temperature components are now required. Using our 450 micron data and fluxes from the literature, we find that the 450/850 micron flux ratio for the galaxies is remarkably constant and this holds from objects in which the star formation rate is similar to our own Galaxy, to ultraluminous infrared galaxies (ULIRGS) such as Arp 220. The only possible explanation for this is if the dust emissivity index for all of the galaxies is ~2 and the cold dust component has a similar temperature in all galaxies (20-21 K). The dust masses estimated using the new temperatures are higher by a factor ~2 than those determined previously using a single temperature. This brings the gas-to-dust ratios of the IRAS galaxies into agreement with those of the Milky Way and other spiral galaxies which have been intensively studied in the submm.

Loretta Dunne; Stephen Eales

2001-06-20T23:59:59.000Z

156

Hot Coal for Christmas: Dust Formation in the Swept-Up Shell Around The Peculiar Type Ib Supernova 2006jc  

E-Print Network [OSTI]

We present evidence for the formation of dust grains in an unusual Type Ib SN based on late-time spectra of SN 2006jc. The progenitor suffered a giant outburst qualitatively similar to those seen in LBVs just 2 years prior to the SN, and we speculate that the dust formation we observe is an indirect consequence of that event. The key evidence for dust formation seen in our optical spectra is (1) the appearance of a strong continuum emission source at red wavelengths, and (2) fading of the redshifted sides of narrow HeI emission lines. These two observed characteristics provide the strongest case yet for dust formation in any Type Ib/c SN. Both developments occurred simultaneously between 51 and 75 days after peak brightness, which is quick compared to other dusty SNe. The high temperature of the dust implies carbon and not silicates, and we describe how infrared photometry may test this conjecture. Geometric considerations indicate dust formation occurring in the dense gas swept-up by the forward shock, and n...

Smith, Nathan; Filippenko, Alexei V

2007-01-01T23:59:59.000Z

157

Metal Dusting of Heat-Resistant Alloys  

E-Print Network [OSTI]

Metal dusting leads to disintegration of such alloys as iron and nickel-based into a “dust” of particulate metal, metal carbide, carbon, and/or oxide. It occurs in strongly carburising environments at 400-900°C. Literature survey has shown...

Al-Meshari, Abdulaziz I

158

Rigidly rotating cylinders of charged dust  

E-Print Network [OSTI]

The gravitational field of a rigidly rotating cylinder of charged dust is found analytically. The general and all regular solutions are divided into three classes. The acceleration and the vorticity of the dust are given, as well as the conditions for the appearance of closed timelike curves.

B. V. Ivanov

2002-07-02T23:59:59.000Z

159

Circumstellar Dust Shells Detlef Schonberner, Matthias Steffen  

E-Print Network [OSTI]

Circumstellar Dust Shells Detlef Sch¨onberner, Matthias Steffen This research project is concerned spectra and intensity maps computed from the resulting time­dependent wind models can be compared directly as spherical grains of amor­ phous carbon with a radius of 0.05 ¯m, the adopted dust­ to­gas ratio being 1

160

Characterisation of Dust Particles Trapped in Silica Aerogels.  

E-Print Network [OSTI]

?? This thesis involves the study of dust particles trapped in silica aerogel for fusion dust diagnostics purpose. The low velocity impact experiments are done… (more)

Liu, Bing

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fugitive dust emissions" 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

Improving Simulations of Fine Dust Surface Concentrations over the Western United States by Optimizing the Particle Size Distribution  

SciTech Connect (OSTI)

To improve estimates of remote contributions of dust to fine particulate matter (PM2.5) in the western United States, new dust particle size distributions (PSDs) based upon scale-invariant fragmentation theory (Kok_PSD) with constraints from in situ measurements (IMP_PSD) are implemented in a chemical transport model (GEOS-Chem). Compared to initial simulations, this leads to reductions in the mass of emitted dust particles with radii <1.8 mm by 40%-60%. Consequently, the root-mean-square error in simulated fine dust concentrations compared to springtime surface observations in the western United States is reduced by 67%-81%. The ratio of simulated fine to coarse PM mass is also improved, which is not achievable by reductions in total dust emissions. The IMP_PSD best represents the PSD of dust transported from remote sources and reduces modeled PM2.5 concentrations up to 5 mg/m3 over the western United States, which is important when considering sources contributing to nonattainment of air quality standards. Citation: Zhang, L., J. F. Kok, D. K. Henze, Q. Li, and C. Zhao (2013), Improving simulations of fine dust surface concentrations over the western United States by optimizing the particle size distribution, Geophys. Res. Lett., 40, 3270-3275, doi:10.1002/grl.50591.

Zhang, Li; Kok, Jasper F.; Henze, Daven; Li, Qinbin; Zhao, Chun

2013-06-28T23:59:59.000Z

162

COMET 22P/KOPFF: DUST ENVIRONMENT AND GRAIN EJECTION ANISOTROPY FROM VISIBLE AND INFRARED OBSERVATIONS  

SciTech Connect (OSTI)

We present optical observations and Monte Carlo models of the dust coma, tail, and trail structures of the comet 22P/Kopff during the 2002 and 2009 apparitions. Dust loss rates, ejection velocities, and power-law size distribution functions are derived as functions of the heliocentric distance using pre- and post-perihelion imaging observations during both apparitions. The 2009 post-perihelion images can be accurately fitted by an isotropic ejection model. On the other hand, strong dust ejection anisotropies are required to fit the near-coma regions at large heliocentric distances (both inbound at r{sub h} = 2.5 AU and outbound at r{sub h} = 2.6 AU) for the 2002 apparition. These asymmetries are compatible with a scenario where dust ejection is mostly seasonally driven, coming mainly from regions near subsolar latitudes at far heliocentric distances inbound and outbound. At intermediate to near-perihelion heliocentric distances, the outgassing would affect much more extended latitude regions, the emission becoming almost isotropic near perihelion. We derived a maximum dust production rate of 260 kg s{sup -1} at perihelion, and an averaged production rate over one orbit of 40 kg s{sup -1}. An enhanced emission rate, also accompanied by a large ejection velocity, is predicted at r{sub h} > 2.5 pre-perihelion. The model has also been extended to the thermal infrared in order to be applied to available trail observations of this comet taken with IRAS and Infrared Space Observatory spacecrafts. The modeled trail intensities are in good agreement with those observations, which is remarkable taking into account that those data are sensitive to dust ejection patterns corresponding to several orbits before the 2002 and 2009 apparitions.

Moreno, Fernando; Pozuelos, Francisco; Aceituno, Francisco; Casanova, Victor; Sota, Alfredo [Instituto de Astrofisica de Andalucia, CSIC, Glorieta de la Astronomia s/n, 18008 Granada (Spain); Castellano, Julio; Reina, Esteban, E-mail: fernando@iaa.es [Amateur Association Cometas-Obs (Spain)

2012-06-20T23:59:59.000Z

163

Large and small-scale structures and the dust energy balance problem in spiral galaxies  

E-Print Network [OSTI]

The interstellar dust content in galaxies can be traced in extinction at optical wavelengths, or in emission in the far-infrared. Several studies have found that radiative transfer models that successfully explain the optical extinction in edge-on spiral galaxies generally underestimate the observed FIR/submm fluxes by a factor of about three. In order to investigate this so-called dust energy balance problem, we use two Milky Way-like galaxies produced by high-resolution hydrodynamical simulations. We create mock optical edge-on views of these simulated galaxies (using the radiative transfer code SKIRT), and we then fit the parameters of a basic spiral galaxy model to these images (using the fitting code FitSKIRT). The basic model includes smooth axisymmetric distributions along a S\\'ersic bulge and exponential disc for the stars, and a second exponential disc for the dust. We find that the dust mass recovered by the fitted models is about three times smaller than the known dust mass of the hydrodynamical in...

Saftly, W; De Geyter, G; Camps, P; Renaud, F; Guedes, J; De Looze, I

2015-01-01T23:59:59.000Z

164

Dust Combustion Safety Issues for Fusion Applications  

SciTech Connect (OSTI)

This report summarizes the results of a safety research task to identify the safety issues and phenomenology of metallic dust fires and explosions that are postulated for fusion experiments. There are a variety of metal dusts that are created by plasma erosion and disruptions within the plasma chamber, as well as normal industrial dusts generated in the more conventional equipment in the balance of plant. For fusion, in-vessel dusts are generally mixtures of several elements; that is, the constituent elements in alloys and the variety of elements used for in-vessel materials. For example, in-vessel dust could be composed of beryllium from a first wall coating, tungsten from a divertor plate, copper from a plasma heating antenna or diagnostic, and perhaps some iron and chromium from the steel vessel wall or titanium and vanadium from the vessel wall. Each of these elements has its own unique combustion characteristics, and mixtures of elements must be evaluated for the mixture’s combustion properties. Issues of particle size, dust temperature, and presence of other combustible materials (i.e., deuterium and tritium) also affect combustion in air. Combustion in other gases has also been investigated to determine if there are safety concerns with “inert” atmospheres, such as nitrogen. Several coolants have also been reviewed to determine if coolant breach into the plasma chamber would enhance the combustion threat; for example, in-vessel steam from a water coolant breach will react with metal dust. The results of this review are presented here.

L. C. Cadwallader

2003-05-01T23:59:59.000Z

165

Residual dust charges in discharge afterglow  

SciTech Connect (OSTI)

An on-ground measurement of dust-particle residual charges in the afterglow of a dusty plasma was performed in a rf discharge. An upward thermophoretic force was used to balance the gravitational force. It was found that positively charged, negatively charged, and neutral dust particles coexisted for more than 1 min after the discharge was switched off. The mean residual charge for 200-nm-radius particles was measured. The dust particle mean charge is about -5e at a pressure of 1.2 mbar and about -3e at a pressure of 0.4 mbar.

Coueedel, L.; Mikikian, M.; Boufendi, L.; Samarian, A. A. [GREMI - Groupe de Recherches sur l'Energetique des Milieux Ionises, CNRS/Universite d'Orleans, 14 rue d'Issoudun, 45067 Orleans Cedex 2 (France); School of Physics A28, University of Sydney, NSW 2006 (Australia)

2006-08-15T23:59:59.000Z

166

Silica dust control when drilling concrete Page 1 of 2  

E-Print Network [OSTI]

Silica dust control when drilling concrete Page 1 of 2 Drilling into concrete releases a fine sandy and routinely drill into concrete are at risk of developing this disease. Controlling the dust Hammer drills are available with attached dust removal systems. These draw dust from the drill end, down the attachment

Knowles, David William

167

Dust-Plasma Sheath in an Oblique Magnetic Field  

SciTech Connect (OSTI)

Using numerical simulations of the multi fluid equations the structure of the magnetized sheath near a plasma boundary is studied in the presence of charged dust particles. The dependence of the electron, ion, and dust densities as well as the electrostatic potential, dust charge, and ion normal velocity, on the magnetic field strength and the edge dust number density is investigated.

Foroutan, G.; Mehdipour, H. [Physics Department, Faculty of Science, Sahand University of Technology, Tabriz (Iran, Islamic Republic of)

2008-09-07T23:59:59.000Z

168

Dust-Acoustic Waves: Visible Sound Waves Robert L. Merlino  

E-Print Network [OSTI]

Dust-Acoustic Waves: Visible Sound Waves Robert L. Merlino Department of Physics and Astronomy with their announcement that: "We find that a new type of sound wave, namely, the dust-acoustic waves, can appear" [1 and experimental work on dust acoustic waves is given. The basic physics of the dust acoustic wave and some

Merlino, Robert L.

169

The gas temperature in circumstellar disks: effects of dust settling  

E-Print Network [OSTI]

The gas temperature in circumstellar disks: effects of dust settling F. Faas, G.J. van Zadelhoff, E distributions. The disk gas-temperature (T ¢¡¢£ ) is in general assumed to be equal to the dust-temperature (T¤¦¥ £ § ), due to collisions. Dust settling depends on both the gas and dust temperature. T

Zadelhoff, Gerd-Jan van

170

Morphological Investigations of Fibrogenic Action of Estonian Oil Shale Dust  

E-Print Network [OSTI]

dust produced in the mining and processing of Estonian oil shale is given. Histological examination of

V. A. Kung

171

Radionuclide air emissions report for the Hanford Site -- calendar year 1997  

SciTech Connect (OSTI)

This report documents radionuclide air emission from the Hanford Site in 1997, and the resulting effective dose equivalent to the maximally exposed member of the public, referred to as the MEI. The report has been prepared in accordance with reporting requirements in the Code of Federal Regulations, Title 40, Protection of the Environment, Part 61, National Emissions Standards for Hazardous Air Pollutants, Subpart H, National Emission Standards for Emissions of Radionuclides Other than Radon from Department of Energy Facilities. This report has also been prepared in accordance with the reporting requirements of the Washington Administrative Code Chapter 246-247, Radiation Protection-Air Emissions. The effective dose equivalent to the MEI from the Hanford Site`s 1997 point source emissions was 1.2 E-03 mrem (1.2 E-05 mSv), which is well below the 40 CFR 61 Subpart H regulatory limit of 10 mrem/yr. Radon and thoron emissions, exempted from 40 CFR 61 Subpart H, resulted in an effective dose equivalent to the MEI of 2.5 E-03 mrem (2.5 E-05 mSv). The effective dose equivalent to the MEI attributable to diffuse and fugitive emissions was 2.2 E-02 mrem (2.2 E-04 mSv). The total effective dose equivalent from all of the Hanford Site`s air emissions was 2.6 E-02 mrem (2.6 E-04 mSv). The effective dose equivalent from all of the Hanford Site`s air emissions is well below the Washington Administrative Code, Chapter 246-247, regulatory limit of 10 mrem/yr.

Gleckler, B.P.; Rhoads, K.

1998-06-17T23:59:59.000Z

172

Dust-regulated galaxy formation and evolution:A new chemodynamical model with live dust particles  

E-Print Network [OSTI]

Interstellar dust plays decisive roles in the conversion of neutral to molecular hydrogen (H_2), the thermodynamical evolution of interstellar medium (ISM), and the modification of spectral energy distributions (SEDs) of galaxies. These important roles of dust have not been self-consistently included in previous numerical simulations of galaxy formation and evolution. We have therefore developed a new model by which one can investigate whether and how galaxy formation and evolution can be influenced by dust-related physical processes such as photo-electric heating, H_2 formation on dust, and stellar radiation pressure on dust in detail. A novel point of the model is that different dust species in a galaxy are represented by `live dust' particles (i.e., not test particles). Therefore, dust particles in a galaxy not only interact gravitationally with all four components of the galaxy (i.e., dark matter, stars, gas, and dust) but also are grown and destroyed through physical processes of ISM. First we describe a...

Bekki, Kenji

2015-01-01T23:59:59.000Z

173

Global coherence of dust density waves  

SciTech Connect (OSTI)

The coherence of self-excited three-dimensional dust density waves has been experimentally investigated by comparing global and local wave properties. For that purpose, three-dimensional dust clouds have been confined in a radio frequency plasma with thermophoretic levitation. Global wave properties have been measured from the line-of-sight integrated dust density obtained from homogenous light extinction measurements. Local wave properties have been obtained from thin, two-dimensional illuminated laser slices of the cloud. By correlating the simultaneous global and local wave properties, the spatial coherence of the waves has been determined. We find that linear waves with small amplitudes tend to be fragmented, featuring an incoherent wave field. Strongly non-linear waves with large amplitudes, however, feature a strong spatial coherence throughout the dust cloud, indicating a high level of synchronization.

Killer, Carsten; Melzer, André [Institut für Physik, Ernst-Moritz-Arndt-Universität Greifswald, 17489 Greifswald (Germany)

2014-06-15T23:59:59.000Z

174

Surface acoustic wave dust deposition monitor  

DOE Patents [OSTI]

A system is disclosed for using the attenuation of surface acoustic waves to monitor real time dust deposition rates on surfaces. The system includes a signal generator, a tone-burst generator/amplifier connected to a transmitting transducer for converting electrical signals into acoustic waves. These waves are transmitted through a path defining means adjacent to a layer of dust and then, in turn, transmitted to a receiving transducer for changing the attenuated acoustic wave to electrical signals. The signals representing the attenuated acoustic waves may be amplified and used in a means for analyzing the output signals to produce an output indicative of the dust deposition rates and/or values of dust in the layer. 8 figs.

Fasching, G.E.; Smith, N.S. Jr.

1988-02-12T23:59:59.000Z

175

He Puff System For Dust Detector Upgrade  

SciTech Connect (OSTI)

Local detection of surface dust is needed for the safe operation of next-step magnetic fusion devices such as ITER. An electrostatic dust detector, based on a 5 cm x 5 cm grid of interlocking circuit traces biased to 50 V, has been developed to detect dust on remote surfaces and was successfully tested for the first time on the National Spherical Torus Experiment (NSTX). We report on a helium puff system that clears residual dust from this detector and any incident debris or fibers that might cause a permanent short circuit. The entire surface of the detector was cleared of carbon particles by two consecutive helium puffs delivered by three nozzles of 0.45 mm inside diameter. The optimal configuration was found to be with the nozzles at an angle of 30o with respect to the surface of the detector and a helium backing pressure of 6 bar. __________________________________________________

B. Rais, C.H. Skinner A.L. Roquemore

2010-10-01T23:59:59.000Z

176

Ice Nuclei in Marine Air: Biogenic Particles or Dust?  

SciTech Connect (OSTI)

Ice nuclei impact clouds, but their sources and distribution in the atmosphere are still not well known. Particularly little attention has been paid to IN sources in marine environments, although evidence from field studies suggests that IN populations in remote marine regions may be dominated by primary biogenic particles associated with sea spray. In this exploratory model study, we aim to bring attention to this long-neglected topic and identify promising target regions for future field campaigns. We assess the likely global distribution of marine biogenic ice nuclei using a combination of historical observations, satellite data and model output. By comparing simulated marine biogenic immersion IN distributions and dust immersion IN distributions, we predict strong regional differences in the importance of marine biogenic IN relative to dust IN. Our analysis suggests that marine biogenic IN are most likely to play a dominant role in determining IN concentrations in near-surface-air over the Southern Ocean, so future field campaigns aimed at investigating marine biogenic IN should target that region. Climate related changes in the abundance and emission of biogenic marine IN could affect marine cloud properties, thereby introducing previously unconsidered feedbacks that influence the hydrological cycle and the Earth’s energy balance. Furthermore, marine biogenic IN may be an important aspect to consider in proposals for marine cloud brightening by artificial sea spray production.

Burrows, Susannah M.; Hoose, C.; Poschl, U.; Lawrence, M.

2013-01-11T23:59:59.000Z

177

Boll Weevil Control by Airplane Dusting.  

E-Print Network [OSTI]

EXPERIMENT STATIGH LiBRl BUILDINC XAS AGRICULTURAL EXPERIMENT STATION A. B. CONNER, DIRECTOR COLLEGE STATION, BRAZOS COUNTY. TEXAS FIN NO. 394 APRIL, 1929 DIVISION OF ENTOMOLOGY BOLL WEEVIL CONTROL BY AIR- PLANE DUSTING - A...~on with the School of Agriculture. rrjshand. unty: tv: SYNOPSIS The cotton acreage in Texas which has been protected against insects by airplane dusting increased from 3,000 acres in 1925 to approximateljr 50,000 acres in 1928, according to information...

Thomas, F. L. (Frank Lincoln)

1929-01-01T23:59:59.000Z

178

Transparent self-cleaning dust shield  

DOE Patents [OSTI]

A transparent electromagnetic shield to protect solar panels and the like from dust deposition. The shield is a panel of clear non-conducting (dielectric) material with embedded parallel electrodes. The panel is coated with a semiconducting film. Desirably the electrodes are transparent. The electrodes are connected to a single-phase AC signal or to a multi-phase AC signal that produces a travelling electromagnetic wave. The electromagnetic field produced by the electrodes lifts dust particles away from the shield and repels charged particles. Deposited dust particles are removed when the electrodes are activated, regardless of the resistivity of the dust. Electrostatic charges on the panel are discharged by the semiconducting film. When used in conjunction with photovoltaic cells, the power for the device may be obtained from the cells themselves. For other surfaces, such as windshields, optical windows and the like, the power must be derived from an external source. One embodiment of the invention employs monitoring and detection devices to determine when the level of obscuration of the screen by dust has reached a threshold level requiring activation of the dust removal feature.

Mazumder, Malay K.; Sims, Robert A.; Wilson, James D.

2005-06-28T23:59:59.000Z

179

Thermo-Oxidation of Tokamak Carbon Dust  

SciTech Connect (OSTI)

The oxidation of dust and flakes collected from the DIII-D tokamak, and various commercial dust specimens, has been measured at 350 ºC and 2.0 kPa O2 pressure. Following an initial small mass loss, most of the commercial dust specimens showed very little effect due to O2 exposure. Similarly, dust collected from underneath DIII-D tiles, which is thought to comprise largely Grafoil™ particulates, also showed little susceptibility to oxidation at this temperature. However, oxidation of the dust collected from tile surfaces has led to ~ 18% mass loss after 8 hours; thereafter, little change in mass was observed. This suggests that the surface dust includes some components of different composition and/or structure – possibly fragments of codeposited layers. The oxidation of codeposit flakes scraped form DIII-D upper divertor tiles showed an initial 25% loss in mass due to heating in vacuum, and the gradual loss of 30-38% mass during the subsequent 24 hours exposure to O2. This behavior is significantly different from that observed for the oxidation of thinner DIII-D codeposit specimens which were still adhered to tile surfaces, and this is thought to be related to the low deuterium content (D/C ~ 0.03 – 0.04) of the flakes.

J.W. Davis; B.W.N. Fitzpatrick; J.P. Sharpe; A.A. Haasz

2008-04-01T23:59:59.000Z

180

Semidirect Dynamical and Radiative Impact of North African Dust Transport on Lower Tropospheric Clouds over the Subtropical North Atlantic in CESM 1.0  

SciTech Connect (OSTI)

This study uses a century length pre-industrial climate simulation by the Community Earth System Model (CESM 1.0) to explore statistical relationships between dust, clouds and atmospheric circulation, and to suggest a dynamical, rather than microphysical, mechanism linking subtropical North Atlantic lower tropospheric cloud cover with North African dust transport. The length of the run allows us to account for interannual variability of dust emissions and transport downstream of North Africa in the model. CESM’s mean climatology and probability distribution of aerosol optical depth in this region agrees well with available AERONET observations. In addition, CESM shows strong seasonal cycles of dust burden and lower tropospheric cloud fraction, with maximum values occurring during boreal summer, when a strong correlation between these two variables exists downstream of North Africa over the subtropical North Atlantic. Calculations of Estimated Inversion Strength (EIS) and composites of EIS on high and low downstream North Africa dust months during boreal summer reveal that dust is likely increasing inversion strength over this region due to both solar absorption and reflection. We find no evidence for a microphysical link between dust and lower tropospheric clouds in this region. These results yield new insight over an extensive period of time into the complex relationship between North African dust and lower tropospheric clouds over the open ocean, which has previously been hindered by spatiotemporal constraints of observations. Our findings lay a framework for future analyses using sub-monthly data over regions with different underlying dynamics.

DeFlorio, Mike; Ghan, Steven J.; Singh, Balwinder; Miller, Arthur J.; Cayan, Dan; Russell, Lynn M.; Somerville, Richard C.

2014-07-16T23:59:59.000Z

Note: This page contains sample records for the topic "fugitive dust emissions" 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

Evolution of the dust mass loss with luminosity along the giant branch of the globular cluster 47 Tuc  

E-Print Network [OSTI]

The paper investigates the properties of the dust mass loss in stars populating the giant branch of the globular cluster 47 Tuc, by combining ISOCAM and DENIS data. Raster maps of 5 fields covering areas ranging from 4 x 4 to 15 x 15 arcmin2 at different distances from the center of the cluster have been obtained with ISOCAM at 11.5 mum (LW10 filter). The covered fields include most of the red variables known in this cluster. A detection threshold of about 0.2 mJy is achieved, allowing to detect giant stars at 11.5 mum all the way down to the horizontal branch. No dust-enshrouded asymptotic giant branch stars have been found in the observed fields, contrary to the situation encountered in LMC/SMC globular clusters with larger turnoff masses. The color index [12]-[2] (based on the ISO 11.5 mum flux and on the DENIS Ks magnitude) is used as a diagnostic of dust emission (and hence dust mass loss). Its evolution with luminosity along the giant branch reveals that dust mass loss is only present in V3 (the only cluster Mira variable observed in the present study) and in V18, a star presenting intermittent variability. This conclusion confirms the importance of stellar pulsations in the dust formation and ensuing mass loss.

A. Ramdani; A. Jorissen

2001-05-02T23:59:59.000Z

182

Large amplitude dust-acoustic solitary waves in electron-positron-ion plasma with dust grains  

SciTech Connect (OSTI)

Propagation of large amplitude dust-acoustic (DA) solitary waves is investigated in electron-positron-ion plasmas in the presence of dust grains using Sagdeev potential method. It is shown that acceptable values of Mach number for propagation of the large amplitude DA solitary waves depend strongly on plasma parameters. It is also observed that the amplitude of DA solitary waves increases as both the Mach number M and dust charge Z{sub d} are increased. Furthermore, it is found that a dusty plasma with inertial dust fluid and Boltzmann distributed electrons, positrons, and ions admits only negative solitary potentials associated with nonlinear dust-acoustic waves. In addition, it is remarked that the formation of double layers is not possible in this plasma system.

Esfandyari-Kalejahi, A.; Afsari-Ghazi, M.; Noori, K.; Irani, S. [Department of Physics, Faculty of Science, Azarbaijan University of Shahid Madani, 51745-406, Tabriz (Iran, Islamic Republic of)

2012-08-15T23:59:59.000Z

183

MILLIMETER EMISSION STRUCTURE IN THE FIRST ALMA IMAGE OF THE AU Mic DEBRIS DISK  

SciTech Connect (OSTI)

We present 1.3 mm ALMA Cycle 0 observations of the edge-on debris disk around the nearby, {approx}10 Myr old, M-type star AU Mic. These observations obtain 0.''6 (6 AU) resolution and reveal two distinct emission components: (1) the previously known dust belt that extends to a radius of 40 AU and (2) a newly recognized central peak that remains unresolved. The cold dust belt of mass {approx}1 M{sub Moon} is resolved in the radial direction with a rising emission profile that peaks sharply at the location of the outer edge of the 'birth ring' of planetesimals hypothesized to explain the midplane scattered light gradients. No significant asymmetries are discerned in the structure or position of this dust belt. The central peak identified in the ALMA image is {approx}6 times brighter than the stellar photosphere, which indicates an additional emission process in the inner regions of the system. Emission from a stellar corona or activity may contribute, but the observations show no signs of temporal variations characteristic of radio-wave flares. We suggest that this central component may be dominated by dust emission from an inner planetesimal belt of mass {approx}0.01 M{sub Moon}, consistent with a lack of emission shortward of 25 {mu}m and a location {approx}<3 AU from the star. Future millimeter observations can test this assertion, as an inner dust belt should be readily separated from the central star at higher angular resolution.

MacGregor, Meredith A.; Wilner, David J.; Rosenfeld, Katherine A.; Andrews, Sean M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Matthews, Brenda; Booth, Mark [Herzberg Institute of Astrophysics, 5072 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Hughes, A. Meredith; Chiang, Eugene; Graham, James R.; Kalas, Paul [Department of Astronomy, 601 Campbell Hall, University of California, Berkeley, CA 94720 (United States); Kennedy, Grant [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Sibthorpe, Bruce [SRON Netherlands Institute for Space Research, NL-9747 AD Groningen (Netherlands)

2013-01-10T23:59:59.000Z

184

E-Print Network 3.0 - annual landfill gas Sample Search Results  

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

systems, and emissions from diesel equipment at the landfill. The MWC emissions... .K. dioxins emissions have been reported in the fugitive gas emissions from landfills as well as...

185

Flammability limits of dusts: Minimum inerting concentrations  

SciTech Connect (OSTI)

A new flammability limit parameter has been defined as the Minimum Inerting Concentration (MIC). This is the concentration of inertant required to prevent a dust explosion regardless of fuel concentration. Previous experimental work at Fike in a 1-m{sup 3} spherical chamber has shown this flammability limit to exist for pulverized coal dust and cornstarch. In the current work, inerting experiments with aluminum, anthraquinone and polyethylene dusts as fuels were performed, using monoammonium phosphate and sodium bicarbonate as inertants. The results show that an MIC exists only for anthraquinone inerted with sodium bicarbonate. The other combustible dust and inertant mixtures did not show a definitive MIC, although they did show a strong dependence between inerting level and suspended fuel concentration. As the fuel concentration increased, the amount of inertant required to prevent an explosion decreased. Even though a definitive MIC was not found for most of the dusts an effective MIC can be estimated from the data. The use of MIC data can aid in the design of explosion suppression schemes.

Dastidar, A.G.; Amyotte, P.R. [Dalhousie Univ., Halifax, Nova Scotia (Canada). Dept. of Chemical Engineering] [Dalhousie Univ., Halifax, Nova Scotia (Canada). Dept. of Chemical Engineering; Going, J.; Chatrathi, K. [Fike Corp., Blue Springs, MO (United States)] [Fike Corp., Blue Springs, MO (United States)

1999-05-01T23:59:59.000Z

186

EVIDENCE FOR A RECEDING DUST SUBLIMATION REGION AROUND A SUPERMASSIVE BLACK HOLE  

SciTech Connect (OSTI)

The near-IR emission in Type 1 active galactic nuclei (AGNs) is thought to be dominated by the thermal radiation from dust grains that are heated by the central engine in the UV/optical and are almost at the sublimation temperature. A brightening of the central source can thus further sublimate the innermost dust, leading to an increase in the radius of the near-IR emitting region. Such changes in radius have been indirectly probed by the measurements of the changes in the time lag between the near-IR and UV/optical light variation. Here we report direct evidence for such a receding sublimation region through the near-IR interferometry of the brightest Type 1 AGN in NGC 4151. The increase in radius follows a significant brightening of the central engine with a delay of at least a few years, which is thus the implied destruction timescale of the innermost dust distribution. Compiling historic flux variations and radius measurements, we also infer the reformation timescale for the inner dust distribution to be several years in this galactic nucleus. More specifically and quantitatively, we find that the radius at a given time seems to be correlated with a long-term average of the flux over the previous several (?6) years, instead of the instantaneous flux. Finally, we also report measurements of three more Type 1 AGNs newly observed with the Keck interferometer, as well as the second epoch measurements for three other AGNs.

Kishimoto, Makoto; Tristram, Konrad R. W.; Weigelt, Gerd [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany)] [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Hönig, Sebastian F.; Antonucci, Robert [Physics Department, University of California, Santa Barbara, CA 93106 (United States)] [Physics Department, University of California, Santa Barbara, CA 93106 (United States); Millan-Gabet, Rafael [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)] [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Barvainis, Richard [National Science Foundation, 4301 Wilson Boulevard, Arlington, VA 22230 (United States)] [National Science Foundation, 4301 Wilson Boulevard, Arlington, VA 22230 (United States); Millour, Florentin [Observatoire de la Côte d Azur, Departement FIZEAU, Boulevard de l'Observatoire, BP 4229, F-06304 Nice Cedex 4 (France)] [Observatoire de la Côte d Azur, Departement FIZEAU, Boulevard de l'Observatoire, BP 4229, F-06304 Nice Cedex 4 (France); Kotani, Takayuki, E-mail: mk@mpifr-bonn.mpg.de [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)] [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)

2013-10-01T23:59:59.000Z

187

Dust in the Radio Galaxy and Merger Remnant NGC 1316 (Fornax A)  

E-Print Network [OSTI]

We present dust maps of NGC 1316 (Fornax A), a well-studied early-type galaxy located in the outskirts of the Fornax cluster. We used the Large APEX BOlometer CAmera (LABOCA), operating at 870 micron with an angular resolution of 19.5 arcseconds on the Atacama Pathfinder EXperiment (APEX) 12m submillimeter telescope in Chile and the Wide-field Infrared Survey Explorer (WISE). WISE observes in four mid-infrared bands centered at 3.4, 4.6, 12 and 22 micron with angular resolutions ranging from 6 to 12 arcseconds. The WISE and LABOCA maps reveal emission from dust in the central 2 arcminutes of NGC 1316. The disturbed optical morphology with many shells and loops, the complex distribution of molecular gas and our dust maps are evidences of past merger activity or gas accretion in the galaxy. Combining the LABOCA flux measurement with existing mid- and far-infrared measurements, we estimate the temperature of the cold (~20 K) and warm (~55 K) dust components in the galaxy. This study will be extended to other sou...

Asabere, Bernard Duah; Winkler, Hartmut; Jarrett, Thomas; Leeuw, Lerothodi

2014-01-01T23:59:59.000Z

188

Dust Studies in DIII-D and TEXTOR  

SciTech Connect (OSTI)

Studies of naturally occurring and artificially introduced carbon dust are conducted in DIII-D and TEXTOR. In DIII-D, dust does not present operational concerns except immediately after entry vents. Submicron sized dust is routinely observed using Mie scattering from a Nd:Yag laser. The source is strongly correlated with the presence of Type I edge localized modes (ELMs). Larger size (0.005-1 mm diameter) dust is observed by optical imaging, showing elevated dust levels after entry vents. Inverse dependence of the dust velocity on the inferred dust size is found from the imaging data. Direct heating of the dust particles by the neutral beam injection (NBI) and acceleration of dust particles by the plasma flows are observed. Energetic plasma disruptions produce significant amounts of dust. Large flakes or debris falling into the plasma may result in a disruption. Migration of pre-characterized carbon dust is studied in DIII-D and TEXTOR by introducing micron-size dust in plasma discharges. In DIII-D, a sample holder filled with {approx}30 mg of dust is introduced in the lower divertor and exposed to high-power ELMing H-mode discharges with strike points swept across the divertor floor. After a brief exposure ({approx}0.1 s) at the outer strike point, part of the dust is injected into the plasma, raising the core carbon density by a factor of 2-3 and resulting in a twofold increase of the radiated power. In TEXTOR, instrumented dust holders with 1-45 mg of dust are exposed in the scrape-off layer 0-2 cm radially outside of the last closed flux surface in discharges heated with neutral beam injection (NBI) power of 1.4 MW. At the given configuration of the launch, the dust did not penetrate the core plasma and only moderately perturbed the edge plasma, as evidenced by an increase of the edge carbon content.

Rudakov, D L; Litnovsky, A; West, W P; Yu, J H; Boedo, J A; Bray, B D; Brezinsek, S; Brooks, N H; Fenstermacher, M E; Groth, M; Hollmann, E M; Huber, A; Hyatt, A W; Krasheninnikov, S I; Lasnier, C J; Moyer, R A; Pigarov, A Y; Philipps, V; Pospieszczyk, A; Smirnov, R D; Sharpe, J P; Solomon, W M; Watkins, J G; Wong, C C

2009-02-17T23:59:59.000Z

189

Oblique interactions of dust density waves  

SciTech Connect (OSTI)

Self-excited dust density waves (DDWs) are studied in a striped electrode device. In addition to the usual perpendicularly (with respect to the electrode) propagating DDWs, which have been frequently observed in dusty plasma experiments on the ground, a low-frequency oblique mode is also observed. This low-frequency oblique DDW has a frequency much lower than the dust plasma frequency and its spontaneous excitation is observed even with a very low dust density. It is found that the low-frequency oblique mode can exist either separately or together with the usual perpendicular mode. In the latter case, a new mode arises as a result of the interactions between the perpendicular and the oblique modes. The experiments show that these three modes satisfy the wave coupling conditions in both the frequencies and the wave-vectors.

Wang, Zhelchui [Los Alamos National Laboratory; Li, Yang - Fang [MAX-PLANCK INSTITUTE; Hou, Lujing [MAX-PLANCK INSTITUTE; Jiang, Ke [MAX-PLANCK INSTITUTE; Wu, De - Jin [CHINA; Thomas, Hubertus M [MAX-PLANCK INSTITUTE; Morfill, Gregor E [MAX-PLANCK INSTITUTE

2010-01-01T23:59:59.000Z

190

Control of Dust Inventory in Tokamaks  

SciTech Connect (OSTI)

Particles with sizes ranging from 100 nm to 100 {mu}m are produced in tokamaks by the interaction of the plasma with the first wall materials and divertor. Dust has not yet been of a major concern in existing tokamaks mainly because their quantities are small and these devices are not nuclear facilities. However, in ITER and in future reactors, they could represent operational and potential safety issues. The aim of this paper is thus to describe the dust creation processes in the tokamak environment. The diagnostics and removal techniques that are needed to be implemented to measure and minimise the dust inventory are also presented. The integration of these techniques into a tokamak environment is also discussed.

Rosanvallon, S.; Grisolia, C. [Association Euratom CEA, CEA/DSM/IRFM, Cadarache, 13108 Saint-Paul-lez-Durance (France); Sharpe, P. [Fusion Safety Program, Idaho National Laboratory, 2525 Fremont Avenue, Idaho Falls, ID 83415-3860 (United States); Andrew, P.; Ciattaglia, S.; Pitcher, C. S.; Taylor, N. [ITER Organization, 13108 St Paul lez Durance (France); Furlan, J. [Fusion For Energy, c/Josep Pla, n. 2, Torres Diagonal Litoral, 08019 Barcelona (Spain)

2008-09-07T23:59:59.000Z

191

Cold condensation of dust in the ISM  

E-Print Network [OSTI]

The condensation of complex silicates with pyroxene and olivine composition at conditions prevailing in molecular clouds has been experimentally studied. For this purpose, molecular species comprising refractory elements were forced to accrete on cold substrates representing the cold surfaces of surviving dust grains in the interstellar medium. The efficient formation of amorphous and homogeneous magnesium iron silicates at temperatures of about 12 K has been monitored by IR spectroscopy. The gaseous precursors of such condensation processes in the interstellar medium are formed by erosion of dust grains in supernova shock waves. In the laboratory, we have evaporated glassy silicate dust analogs and embedded the released species in neon ice matrices that have been studied spectroscopically to identify the molecular precursors of the condensing solid silicates. A sound coincidence between the 10 micron band of the interstellar silicates and the 10 micron band of the low-temperature siliceous condensates can be...

Rouillé, Gaël; Krasnokutski, Serge A; Krebsz, Melinda; Henning, Thomas

2015-01-01T23:59:59.000Z

192

The heating mechanism for the warm/cool dust in powerful, radio-loud AGN  

E-Print Network [OSTI]

The uncertainty surrounding the nature of the heating mechanism for the dust that emits at mid- to far-IR (MFIR) wavelengths in active galaxies limits our understanding of the links between active galactic nuclei (AGN) and galaxy evolution, as well as our ability to interpret the prodigious infrared and sub-mm emission of some of the most distant galaxies in the Universe. Here we report deep Spitzer observations of a complete sample of powerful, intermediate redshift (0.05 power, as traced by [OIII]5007 emission, is strongly correlated with both the mid-IR (24 micron) and the far-IR (70 micron) luminosities, however, with increased scatter in the 70 micron correlation. A major cause of this increased scatter is a group of objects that falls above the main correlation and displays evidence for prodigious recent star formation activity at optical wavelengths, along with relatively cool MFIR colours. These results provide evidence that illumination by the AGN is the primary heating mechanism for the dust emitting at both 24 and 70 microns, with starbursts dominating the heating of the cool dust in only 20 -- 30% of objects. This implies that powerful AGN are not always accompanied by the type of luminous starbursts that are characteristic of the peak of activity in major gas-rich mergers.

C. Tadhunter; D. Dicken; J. Holt; K. Inskip; R. Morganti; D. Axon; C. Buchanan; R. González Delgado; P. Barthel; I. van Bemmel

2007-03-30T23:59:59.000Z

193

The Dust Properties of Bubble HII Regions as seen by Herschel  

E-Print Network [OSTI]

Because of their relatively simple morphology, "bubble" HII regions have been instrumental to our understanding of star formation triggered by HII regions. With the far-infrared (FIR) spectral coverage of the Herschel satellite, we can access the wavelengths where these regions emit the majority of their energy through their dust emission. At Herschel wavelengths 70 micron to 500 micron, the emission associated with HII regions is dominated by the cool dust in their photodissociation regions (PDRs). We find average dust temperatures of 26K along the PDRs, with little variation between the HII regions in the sample, while local filaments and infrared dark clouds average 19K and 15K respectively. Higher temperatures lead to higher values of the Jeans mass, which may affect future star formation. The mass of the material in the PDR, collected through the expansion of the HII region, is between ~300 and ~10,000 Solar masses for the HII regions studied here. These masses are in rough agreement with the expected ma...

Anderson, L D; Deharveng, L; Abergel, A; Motte, F; Andre, Ph; Bernard, J -P; Bontemps, S; Hennemann, M; Hill, T; Rodon, J A; Roussel, H; Russeil, D

2012-01-01T23:59:59.000Z

194

Algebraically general, gravito-electric rotating dust  

E-Print Network [OSTI]

The class of gravito-electric, algebraically general, rotating `silent' dust space-times is studied. The main invariant properties are deduced. The number $t_0$ of functionally independent zero-order Riemann invariants satisfies $1\\leq t_0\\leq 2$ and special attention is given to the subclass $t_0=1$. Whereas there are no $\\Lambda$-term limits comprised in the class, the limit for vanishing vorticity leads to two previously derived irrotational dust families with $\\Lambda>0$, and the shear-free limit is the G\\"{o}del universe.

Lode Wylleman

2008-06-17T23:59:59.000Z

195

Design of a new cotton dust sampler  

E-Print Network [OSTI]

FIGURE Page Vertical elutriator cotton dust sampler The penetration curve of the VE which has a cutpoint of 9. 7 um and a slope of 1. 5 (Grimm, 1981) . . . . . . . 13 The penetration curve of the VE which has a cutpoint of 10. 5 um and a slope of l... of the cyclone cotton dust sampler 36 37 39 13 Cyclone sampler penetration curve which has a slope of 1. 31 and a cutpoint of 10. 1 um 45 14 Comparison of the penetration curves of the cyclone sampler and verticle elutriator 46 15 The relationship...

Hickman, Phillip Dean

2012-06-07T23:59:59.000Z

196

aeolian dust climate: Topics by E-print Network  

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

of dust deposition, grain size, and mineralogical and chemical composition relative to climate and to type and lithology of dust source. The average silt and clay flux (rate of...

197

airborne respirable dust: Topics by E-print Network  

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

Distributed Sensor Networks and Ad-hoc Networking 4 1.2.2 High Level Interpretation of Spatial Sensor Data 4 1.2.3 Distributed Processing 5 1.2.4 COTS Dust 6 2.0 COTS Dust...

198

Saharan dust particles nucleate droplets in eastern Atlantic clouds Cynthia H. Twohy,1  

E-Print Network [OSTI]

as CCN. Given the dual nature of Saharan dust particles as CCN and ice nuclei, this infusion of dust

Collett Jr., Jeffrey L.

199

An integrated analytical framework for quantifying the LCOE of waste-to-energy facilities for a range of greenhouse gas emissions policy and technical factors  

SciTech Connect (OSTI)

This study presents a novel integrated method for considering the economics of waste-to-energy (WTE) facilities with priced greenhouse gas (GHG) emissions based upon technical and economic characteristics of the WTE facility, MSW stream, landfill alternative, and GHG emissions policy. The study demonstrates use of the formulation for six different policy scenarios and explores sensitivity of the results to ranges of certain technical parameters as found in existing literature. The study shows that details of the GHG emissions regulations have large impact on the levelized cost of energy (LCOE) of WTE and that GHG regulations can either increase or decrease the LCOE of WTE depending on policy choices regarding biogenic fractions from combusted waste and emissions from landfills. Important policy considerations are the fraction of the carbon emissions that are priced (i.e. all emissions versus only non-biogenic emissions), whether emissions credits are allowed due to reducing fugitive landfill gas emissions, whether biogenic carbon sequestration in landfills is credited against landfill emissions, and the effectiveness of the landfill gas recovery system where waste would otherwise have been buried. The default landfill gas recovery system effectiveness assumed by much of the industry yields GHG offsets that are very close to the direct non-biogenic GHG emissions from a WTE facility, meaning that small changes in the recovery effectiveness cause relatively larger changes in the emissions factor of the WTE facility. Finally, the economics of WTE are dependent on the MSW stream composition, with paper and wood being advantageous, metal and glass being disadvantageous, and plastics, food, and yard waste being either advantageous or disadvantageous depending upon the avoided tipping fee and the GHG emissions price.

Townsend, Aaron K., E-mail: aarontownsend@utexas.edu [Department of Mechanical Engineering, University of Texas at Austin, 1 University Station C2200, Austin, TX 78712 (United States); Webber, Michael E. [Department of Mechanical Engineering, University of Texas at Austin, 1 University Station C2200, Austin, TX 78712 (United States)

2012-07-15T23:59:59.000Z

200

Discovery of 10 micron silicate emission in quasars. Evidence of the AGN unification scheme  

E-Print Network [OSTI]

According to the unified scheme, AGN are surrounded by a dust-torus, and the observed diversity of AGN properties results from the different orientations relative to our line of sight. The strong resonance of silicate dust at 10 micron is therefore, as expected, seen in absorption towards many type-2 AGN. In type-1 AGN, it should be seen in emission because the hot inner surface of the dust torus becomes visible. However, this has not been observed so far, thus challenging the unification scheme or leading to exotic modifications of the dust-torus model. Here we report the discovery of the 10 micron silicate feature in emission in two luminous quasars with the Infrared Spectrograph of the Spitzer Space Telescope.

R. Siebenmorgen; M. Haas; E. Kr"ugel; B. Schulz

2005-04-12T23:59:59.000Z

Note: This page contains sample records for the topic "fugitive dust emissions" 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

Statistical charge distribution over dust particles in a non-Maxwellian Lorentzian plasma  

SciTech Connect (OSTI)

On the basis of statistical mechanics and charging kinetics, the charge distribution over uniform size spherical dust particles in a non-Maxwellian Lorentzian plasma is investigated. Two specific situations, viz., (i) the plasma in thermal equilibrium and (ii) non-equilibrium state where the plasma is dark (no emission) or irradiated by laser light (including photoemission) are taken into account. The formulation includes the population balance equation for the charged particles along with number and energy balance of the complex plasma constituents. The departure of the results for the Lorentzian plasma, from that in case of Maxwellian plasma, is graphically illustrated and discussed; it is shown that the charge distribution tends to results corresponding to Maxwellian plasma for large spectral index. The charge distribution predicts the opposite charging of the dust particles in certain cases.

Mishra, S. K. [Institute for Plasma Research (IPR), Gandhinagar-382428 (India); Misra, Shikha, E-mail: shikhamish@gmail.com [Centre for Energy Studies (CES), Indian Institute of Technology Delhi (IITD), New Delhi-110016 (India)

2014-07-15T23:59:59.000Z

202

An Alternate Approach to Determine the Explosibility of Dusts  

E-Print Network [OSTI]

dust cloud; a 10,000 Joule (10 kJ) flame is subsequently forced through the dust cloud and the resulting pressure rise is measured. If the pressure rise exceeds one bar (14.5 psig), it is assumed that a deflagration occurred, and the dust is classified...

Ganesan, Balaji

2013-12-04T23:59:59.000Z

203

USING THE X-RAY DUST SCATTERING HALO OF CYGNUS X-1 TO DETERMINE DISTANCE AND DUST DISTRIBUTIONS  

E-Print Network [OSTI]

We present a detailed study of the X-ray dust scattering halo of the black hole candidate Cygnus X-1 based on two Chandra High Energy Transmission Gratings Spectrometer observations. Using 18 different dust models, including ...

Xiang, Jingen

204

Study of metal dusting phenomenon and development of materials resistant to metal dusting.  

SciTech Connect (OSTI)

The deposition of carbon from carbonaceous gaseous environments is prevalent in many chemical and petrochemical processes such as reforming systems, syngas production systems, iron reduction plants, and others. One of the major consequences of carbon deposition is the degradation of structural materials by a phenomenon known as metal dusting. There are two major issues of importance in metal dusting. First is formation of carbon and subsequent deposition of carbon on metallic materials. Second is the initiation of metal dusting degradation of the alloy. Details are presented on a research program that is underway at Argonne National Laboratory to study the metal dusting phenomenon from a fundamental scientific base involving laboratory research in simulated process conditions and field testing of materials in actual process environments. The project has participation from the US chemical industry, alloy manufacturers, and the Materials Technology Institute, which serves the chemical process industry.

Natesan, K.

2002-03-13T23:59:59.000Z

205

Recycling of electric-arc-furnace dust  

SciTech Connect (OSTI)

Electric arc furnace (EAF) dust is one of the largest solid waste streams produced by steel mills, and is classified as a waste under the Resource Conservation and Recovery Act (RCRA) by the U.S. Environmental Protection Agency (EPA). Successful recycle of the valuable metals (iron, zinc, and lead) present in the dust will result in resource conservation while simultaneously reducing the disposal problems. Technical feasibility of a novel recycling method based on using hydrogen as the reductant was established under this project through laboratory experiments. Sponge iron produced was low in zinc, cadmium, and lead to permit its recycle, and nontoxic to permit its safe disposal as an alternative to recycling. Zinc oxide was analyzed to contain 50% to 58% zinc by weight, and can be marketed for recovering zinc and lead. A prototype system was designed to process 2.5 tons per day (600 tons/year) of EAF dust, and a preliminary economic analysis was conducted. The cost of processing dust by this recycling method was estimated to be comparable to or lower than existing methods, even at such low capacities.

Sresty, G.C.

1990-05-01T23:59:59.000Z

206

The general double-dust solution  

E-Print Network [OSTI]

The gravitational field of two identical rotating and counter-moving dust beams is found in full generality. The solution depends on an arbitrary function and a parameter. Some of its properties are studied. Previous particular solutions are derived as subcases.

B. V. Ivanov

2003-02-04T23:59:59.000Z

207

Intergalactic dust and its photoelectric heating  

E-Print Network [OSTI]

We have examined the dust photoelectric heating in the intergalactic medium (IGM). The heating rate in a typical radiation field of the IGM is represented by $\\Gamma_{\\rm pe} = 1.2\\times10^{-34}$ erg s$^{-1}$ cm$^{-3}$ $({\\cal D}/10^{-4})(n_{\\rm H}/10^{-5} {\\rm cm^{-3}})^{4/3} (J_{\\rm L}/10^{-21} {\\rm erg s^{-1} cm^{-2} Hz^{-1} sr^{-1}})^{2/3} (T/10^4 {\\rm K})^{-1/6}$, where ${\\cal D}$ is the dust-to-gas mass ratio, $n_{\\rm H}$ is the hydrogen number density, $J_{\\rm L}$ is the mean intensity at the hydrogen Lyman limit of the background radiation, and $T$ is the gas temperature, if we assume the new X-ray photoelectric yield model by Weingartner et al. (2006) and the dust size distribution in the Milky Way by Mathis, Rumpl, & Nordsieck (1977). This heating rate dominates the HI and HeII photoionization heating rates when the hydrogen number density is less than $\\sim10^{-6}$ cm$^{-3}$ if ${\\cal D}=10^{-4}$ which is 1% of that in the Milky Way, although the heating rate is a factor of 2--4 smaller than that with the old yield model by Weingartner & Draine (2001). The grain size distribution is very important. If only large ($\\ge0.1$ $\\mu$m) grains exist in the IGM, the heating rate is reduced by a factor of $\\simeq5$. Since the dust heating is more efficient in a lower density medium relative to the photoionization heating, it may cause an inverted temperature--density relation in the low density IGM suggested by Bolton et al. (2008). Finally, we have found that the dust heating is not very important in the mean IGM before the cosmic reionization.

Akio K. Inoue; Hideyuki Kamaya

2008-10-31T23:59:59.000Z

208

ITP Mining: Energy and Environmental Profile of the U.S. Mining...  

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

Fugitive dust generated during crushing and grinding activities is usually collected by air pollution control devices and recirculated into the beneficiation circuit. Most mills...

209

Tax Credits, Rebates & Savings | Department of Energy  

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

Investor-Owned Utility Tax Credits, Rebates & Savings Tax Credits, Rebates & Savings Air Pollution Control Regulations: No. 5- Fugitive Dust (Rhode Island) These regulations aim...

210

A SPITZER SURVEY OF PROTOPLANETARY DISK DUST IN THE YOUNG SERPENS CLOUD: HOW DO DUST CHARACTERISTICS EVOLVE WITH TIME?  

SciTech Connect (OSTI)

We present Spitzer InfraRed Spectrograph (IRS) mid-infrared (5-35 {mu}m) spectra of a complete flux-limited sample ({>=}3 mJy at 8 {mu}m) of young stellar object (YSO) candidates selected on the basis of their infrared colors in the Serpens Molecular Cloud. Spectra of 147 sources are presented and classified. Background stars (with slope consistent with a reddened stellar spectrum and silicate features in absorption), galaxies (with redshifted polycyclic aromatic hydrocarbon (PAH) features), and a planetary nebula (with high ionization lines) amount to 22% of contamination in this sample, leaving 115 true YSOs. Sources with rising spectra and ice absorption features, classified as embedded Stage I protostars, amount to 18% of the sample. The remaining 82% (94) of the disk sources are analyzed in terms of spectral energy distribution shapes, PAHs, and silicate features. The presence, strength, and shape of these silicate features are used to infer disk properties for these systems. About 8% of the disks have 30/13 {mu}m flux ratios consistent with cold disks with inner holes or gaps, and 3% of the disks show PAH emission. Comparison with models indicates that dust grains in the surface of these disks have sizes of at least a few {mu}m. The 20 {mu}m silicate feature is sometimes seen in the absence of the 10 {mu}m feature, which may be indicative of very small holes in these disks. No significant difference is found in the distribution of silicate feature shapes and strengths between sources in clusters and in the field. Moreover, the results in Serpens are compared with other well-studied samples: the c2d IRS sample distributed over five clouds and a large sample of disks in the Taurus star-forming region. The remarkably similar distributions of silicate feature characteristics in samples with different environment and median ages-if significant-imply that the dust population in the disk surface results from an equilibrium between dust growth and destructive collision processes that are maintained over a few million years for any YSO population irrespective of environment.

Oliveira, Isa; Van Dishoeck, Ewine F.; Lahuis, Fred [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands); Pontoppidan, Klaus M. [California Institute of Technology, Division for Geological and Planetary Sciences, MS 150-21, Pasadena, CA 91125 (United States); MerIn, Bruno [Herschel Science Center, European Space Agency (ESA), P.O. Box 78, 28691 Villanueva de la Canada (Madrid) (Spain); Geers, Vincent C. [University of Toronto, 50 St. George St., Toronto, ON M5R 2W9 (Canada); Joergensen, Jes K. [Centre for Star and Planet Formation, Natural History Museum of Denmark, University of Copenhagen, Oester Voldgade 5-7, DK-1350 Copenhagen (Denmark); Olofsson, Johan; Augereau, Jean-Charles [Laboratoire d'Astrophysique de Grenoble, Universite Joseph Fourier, CNRS, UMR 5571, Grenoble (France); Brown, Joanna M., E-mail: oliveira@strw.leidenuniv.n [Max-Planck Institut fuer Extraterrestrische Physik, Giessenbachstrasse 1, 85748 Garching (Germany)

2010-05-01T23:59:59.000Z

211

U.S. zero emission coal alliance techology  

SciTech Connect (OSTI)

For coal to maintain its major role in supplying the world's energy, eventually all emissions to the atmosphere must be eliminated. Not only must conventional pollutants, like sulfur compounds and dust particles be kept out of the air, but also the far larger quantities of carbon dioxide that result from the combustion of carbon. We present a new technology for coal-based power that generates hydrogen from carbon and water, avoids emissions to the atmosphere, and disposes of the carbon dioxide as inert, solid mineral carbonates. Based on the available resources, coal power is sustainable for centuries. Our zero emission technology makes coal energy as clean as renewable energy.

Lackner, K. S. (Klaus S.); Ziock, H. J. (Hans-Joachim)

2001-01-01T23:59:59.000Z

212

3 MV hypervelocity dust accelerator at the Colorado Center for Lunar Dust and Atmospheric Studies  

SciTech Connect (OSTI)

A hypervelocity dust accelerator for studying micrometeorite impacts has been constructed at the Colorado Center for Lunar Dust and Atmospheric Studies (CCLDAS) at the University of Colorado. Based on the Max-Planck-Instituet fuer Kernphysik (MPI-K) accelerator, this accelerator is capable of emitting single particles of a specific mass and velocity selected by the user. The accelerator consists of a 3 MV Pelletron generator with a dust source, four image charge pickup detectors, and two interchangeable target chambers: a large high-vacuum test bed and an ultra-high vacuum impact study chamber. The large test bed is a 1.2 m diameter, 1.5 m long cylindrical vacuum chamber capable of pressures as low as 10{sup -7} torr while the ultra-high vacuum chamber is a 0.75 m diameter, 1.1 m long chamber capable of pressures as low as 10{sup -10} torr. Using iron dust of up to 2 microns in diameter, final velocities have been measured up to 52 km/s. The spread of the dust particles and the effect of electrostatic focusing have been measured using a long exposure CCD and a quartz target. Furthermore, a new technique of particle selection is being developed using real time digital filtering techniques. Signals are digitized and then cross-correlated with a shaped filter, resulting in a suppressed noise floor. Improvements over the MPI-K design, which include a higher operating voltage and digital filtering for detection, increase the available parameter space of dust emitted by the accelerator. The CCLDAS dust facility is a user facility open to the scientific community to assist with instrument calibrations and experiments.

Shu, Anthony; Horanyi, Mihaly; Kempf, Sascha; Thomas, Evan [Colorado Center for Lunar Dust and Atmospheric Studies, Boulder, Colorado 80303 (United States); Department of Physics, University of Colorado, Boulder, Colorado 80309 (United States); Laboratory for Atmospheric and Space Physics, 1234 Innovation Drive, Boulder, Colorado 80303 (United States); Collette, Andrew; Drake, Keith; Northway, Paige [Colorado Center for Lunar Dust and Atmospheric Studies, Boulder, Colorado 80303 (United States); Laboratory for Atmospheric and Space Physics, 1234 Innovation Drive, Boulder, Colorado 80303 (United States); Gruen, Eberhard [Colorado Center for Lunar Dust and Atmospheric Studies, Boulder, Colorado 80303 (United States); MPI fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Mocker, Anna [Colorado Center for Lunar Dust and Atmospheric Studies, Boulder, Colorado 80303 (United States); MPI fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); IRS, Universitaet Stuttgart, Pfaffenwaldring 31, D-70569 Stuttgart (Germany); Munsat, Tobin [Colorado Center for Lunar Dust and Atmospheric Studies, Boulder, Colorado 80303 (United States); Department of Physics, University of Colorado, Boulder, Colorado 80309 (United States); Srama, Ralf [MPI fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); IRS, Universitaet Stuttgart, Pfaffenwaldring 31, D-70569 Stuttgart (Germany); and others

2012-07-15T23:59:59.000Z

213

E-Print Network 3.0 - areas treating landfill Sample Search Results  

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

Conference COMPARISON OF AIR EMISSIONS FROM WASTE MANAGEMENT FACILITIES Summary: .K. dioxins emissions have been reported in the fugitive gas emissions from landfills as well as...

214

Dust Plume Modeling at Fort Bliss: Move-Out Operations, Combat Training and Wind Erosion  

SciTech Connect (OSTI)

The potential for air-quality impacts from heavy mechanized vehicles operating in the training ranges and on the unpaved main supply routes at Fort Bliss was investigated. This report details efforts by the staff of Pacific Northwest National Laboratory for the Fort Bliss Directorate of Environment in this investigation. Dust emission and dispersion from typical activities, including move outs and combat training, occurring on the installation were simulated using the atmospheric modeling system DUSTRAN. Major assumptions associated with designing specific modeling scenarios are summarized, and results from the simulations are presented.

Chapman, Elaine G.; Rishel, Jeremy P.; Rutz, Frederick C.; Seiple, Timothy E.; Newsom, Rob K.; Allwine, K Jerry

2006-09-29T23:59:59.000Z

215

Transport of dust particles in inductively coupled discharges  

SciTech Connect (OSTI)

Contamination by particulates, or ``dust``, in plasma processing reactors decreases the yield of microelectronic components. In low temperature plasmas, such as those used in etching or deposition reactors to fabricate semiconductor devices, the particles can form to appreciable densities. These particles can be trapped or expelled from the reactor, depending on which forces dominate their transport. Quantities that affect dust motion in Inductively Coupled Plasma (ICP) discharges are the charge of the dust particles (electrostatic forces), momentum transfer with ions (viscous ion-drag forces), temperature gradients from heated electrodes (thermophoretic forces), and gas flow (fluid drag forces). The authors have developed a 2-D Monte Carlo simulation to investigate the trajectories of dust particles in ICP reactors. The model may have an arbitrary number and variety of dust species, and different gas mixtures may be used. The self-consistent electric fields, ion energy distributions, and species densities are imported from a companion Monte Carlo-fluid hybrid model. A semi-analytic model is used to determine the dust charge as well as the momentum transfer cross sections between dust and ions. The electrode topography can also affect the trapping locations of dust. Grooves on the electrodes perturb electrical forces and heated washers can change the thermophoretic forces; hence the spatial dust density varies from the case with a smooth, nonheated electrode. These effects on particle trapping will be presented. Other factors on trapping locations, such as dust particle size and varying power flow with time, will also be discussed.

Hwang, H.H.; Ventzek, P.L.G.; Hoekstra, R.; Kushner, M.J. [Univ. of Illinois, Urbana, IL (United States). Dept. of Electrical and Computer Engineering

1994-12-31T23:59:59.000Z

216

Radioactive Air Emissions Notice of Construction (NOC) for the 300 Area Process Sewer Cleanout  

SciTech Connect (OSTI)

This document serves as a NOC pursuant to the requirements of Washington Administrative Code (WAC) 246-247-060, and as a request for approval to construct pursuant to 40 Code of Federal Regulations (CFR) 61.07, for the cleanout of sections of the 300 Area PS. Approval of the NOC will allow the pressure washing of certain pipe sections, the sump in the TEDF lift station, and the cleaning of PS 16 of the 300 Area PS that contains low levels of radioactivity. Section 15.0 of this NOC discusses the estimated total effective dose equivalent (TEDE) to the offsite maximally exposed individual (MEI) resulting from the unabated emissions from these cleaning activities. Using the currently approved unit dose conversion factors in HNF-3602, the estimated potential TEDE to the MEI resulting from the unabated, fugitive emissions from cleanout of the 300 Area PS is 4.70 E-05 millirem (mrem) per year. This dose was derived by conservatively estimating the doses from both the pressure washing and the use of the Guzzler{trademark} for removal of the liquid/soil mixture, as described in Section 5.0. and adding these doses together.

MENARD, N.M.

2000-06-16T23:59:59.000Z

217

Scattered Light from Dust in the Cavity of the V4046 Sgr Transition Disk  

E-Print Network [OSTI]

We report the presence of scattered light from dust grains located in the giant planet formation region of the circumbinary disk orbiting the ~20-Myr-old close (~0.045 AU separation) binary system V4046 Sgr AB based on observations with the new Gemini Planet Imager (GPI) instrument. These GPI images probe to within ~7 AU of the central binary with linear spatial resolution of ~3 AU, and are thereby capable of revealing dust disk structure within a region corresponding to the giant planets in our solar system. The GPI imaging reveals a relatively narrow (FWHM ~10 AU) ring of polarized near-infrared flux whose brightness peaks at ~14 AU. This ~14 AU radius ring is surrounded by a fainter outer halo of scattered light extending to ~45 AU, which coincides with previously detected mm-wave thermal dust emission. The presence of small grains that efficiently scatter starlight well inside the mm-wavelength disk cavity supports current models of planet formation that suggest planet-disk interactions can generate press...

Rapson, Valerie A; Andrews, Sean M; Hines, Dean C; Macintosh, Bruce; Millar-Blanchaer, Max; Tamura, Motohide

2015-01-01T23:59:59.000Z

218

A Strategy to Minimize Dust Foregrounds in B-mode Searches  

E-Print Network [OSTI]

The Planck satellite has identified several patches of sky with low polarized dust emission, obvious targets for searches for the cosmic-microwave-background (CMB) B-mode signal from inflationary gravitational waves. Still, given the Planck measurement uncertainties, the polarized dust foregrounds in these different candidate patches may differ by an order of magnitude or more. Here we show that a brief initial experiment to map these candidate patches more deeply at a single high frequency can efficiently zero in on the cleanest patch(es) and thus improve significantly the sensitivity of subsequent B-mode searches. A ground-based experiment with current detector technology operating at >~220 GHz for 3 months can efficiently identify a low-dust-amplitude patch and thus improve by up to 20%-60% on the sensitivity to cosmic B modes of the subsequent lower-frequency deep integration. A balloon experiment with current detector sensitivities covering the set of patches and operating at ~350 GHz can reach a similar...

Kovetz, Ely D

2015-01-01T23:59:59.000Z

219

Saving Fuel, Reducing Emissions  

E-Print Network [OSTI]

lower greenhouse gas emissions from electricity productionAssessment of Greenhouse Gas Emissions from Plug-in Hybridof national greenhouse gas emissions. Both motor vehicle

Kammen, Daniel M.; Arons, Samuel M.; Lemoine, Derek M.; Hummel, Holmes

2009-01-01T23:59:59.000Z

220

Silicate Dust in Evolved Protoplanetary Disks: Growth, Sedimentation, and Accretion  

E-Print Network [OSTI]

We present the Spitzer IRS spectra for 33 young stars in Tr 37 and NGC 7160. The sample includes the high- and intermediate-mass stars with MIPS 24 microns excess, the only known active accretor in the 12 Myr-old cluster NGC 7160, and 19 low-mass stars with disks in the 4 Myr-old cluster Tr 37. We examine the 10 microns silicate feature, present in the whole sample of low-mass star and in 3 of the high- and intermediate-mass targets, and we find that PAH emission is detectable only in the Herbig Be star. We analyze the composition and size of the warm photospheric silicate grains by fitting the 10 microns silicate feature, and study the possible correlations between the silicate characteristics and the stellar and disk properties (age, SED slope, accretion rate, spectral type). We find indications of dust settling with age and of the effect of turbulent enrichment of the disk atmosphere with large grains. Crystalline grains are only small contributors to the total silicate mass in all disks, and do not seem to correlate with any other property, except maybe binarity. We also observe that spectra with very weak silicate emission are at least 3 times more frequent among M stars than among earlier spectral types, which may be an evidence of inner disk evolution. Finally, we find that 5 of the high- and intermediate-mass stars have SEDs and IRS spectra consistent with debris disk models involving planet formation, which could indicate debris disk formation at ages as early as 4 Myr.

Aurora Sicilia-Aguilar; L. W. Hartmann; Dan Watson; Chris Bohac; Thomas Henning; Jeroen Bouwman

2007-01-11T23:59:59.000Z

Note: This page contains sample records for the topic "fugitive dust emissions" 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

Modeling dust as component minerals in the Community Atmosphere Model: development of framework and impact on radiative forcing  

SciTech Connect (OSTI)

The mineralogy of desert dust is important due to its effect on radiation, clouds and biogeochemical cycling of trace nutrients. This study presents the simulation of dust radiative forcing as a function of both mineral composition and size at the global scale using mineral soil maps for estimating emissions. Externally mixed mineral aerosols in the bulk aerosol module in the Community Atmosphere Model version 4 (CAM4) and internally mixed mineral aerosols in the modal aerosol module in the Community Atmosphere Model version 5.1 (CAM5) embedded in the Community Earth System Model version 1.0.5 (CESM) are speciated into common mineral components in place of total dust. The simulations with mineralogy are compared to available observations of mineral atmospheric distribution and deposition along with observations of clear-sky radiative forcing efficiency. Based on these simulations, we estimate the all-sky direct radiative forcing at the top of the atmosphere as +0.05Wm?2 for both CAM4 and CAM5 simulations with mineralogy and compare this both with simulations of dust in release versions of CAM4 and CAM5 (+0.08 and +0.17Wm?2) and of dust with optimized optical properties, wet scavenging and particle size distribution in CAM4 and CAM5, ?0.05 and ?0.17Wm?2, respectively. The ability to correctly include the mineralogy of dust in climate models is hindered by its spatial and temporal variability as well as insufficient global in-situ observations, incomplete and uncertain source mineralogies and the uncertainties associated with data retrieved from remote sensing methods.

Scanza, Rachel; Mahowald, N.; Ghan, Steven J.; Zender, C. S.; Kok, J. F.; Liu, Xiaohong; Zhang, Y.; Albani, Samuel

2015-01-01T23:59:59.000Z

222

The effect of dust size distribution on quantum dust acoustic wave  

SciTech Connect (OSTI)

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

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

2009-09-15T23:59:59.000Z

223

Technology Assessment of Dust Suppression Techniques Applied During Structural Demolition  

SciTech Connect (OSTI)

Hanford, Fernald, Savannah River, and other sites are currently reviewing technologies that can be implemented to demolish buildings in a cost-effective manner. In order to demolish a structure properly and, at the same time, minimize the amount of dust generated from a given technology, an evaluation must be conducted to choose the most appropriate dust suppression technology given site-specific conditions. Thus, the purpose of this research, which was carried out at the Hemispheric Center for Environmental Technology (HCET) at Florida International University, was to conduct an experimental study of dust aerosol abatement (dust suppression) methods as applied to nuclear D and D. This experimental study targeted the problem of dust suppression during the demolition of nuclear facilities. The resulting data were employed to assist in the development of mathematical correlations that can be applied to predict dust generation during structural demolition.

Boudreaux, J.F.; Ebadian, M.A.; Williams, P.T.; Dua, S.K.

1998-10-20T23:59:59.000Z

224

Old supernova dust factory revealed at the Galactic center  

E-Print Network [OSTI]

Dust formation in supernova ejecta is currently the leading candidate to explain the large quantities of dust observed in the distant, early Universe. However, it is unclear whether the ejecta-formed dust can survive the hot interior of the supernova remnant (SNR). We present infrared observations of ~0.02 $M_\\odot$ of warm (~100 K) dust seen near the center of the ~10,000 yr-old Sgr A East SNR at the Galactic center. Our findings signify the detection of dust within an older SNR that is expanding into a relatively dense surrounding medium ($n_e$ ~ 100 $\\mathrm{cm}^{-3}$) and has survived the passage of the reverse shock. The results suggest that supernovae may indeed be the dominant dust production mechanism in the dense environment of early Universe galaxies.

Lau, Ryan M; Morris, Mark R; Li, Zhiyuan; Adams, Joseph D

2015-01-01T23:59:59.000Z

225

Dust accelerators and their applications in high-temperature plasmas  

SciTech Connect (OSTI)

The perennial presence of dust in high-temperature plasma and fusion devices has been firmly established. Dust inventory must be controlled, in particular in the next-generation steady-state fusion machines like ITER, as it can pose significant safety hazards and potentially interfere with fusion energy production. Much effort has been devoted to gening rid of the dust nuisance. We have recognized a number of dust-accelerators applications in magnetic fusion, including in plasma diagnostics, in studying dust-plasma interactions, and more recently in edge localized mode (ELM)'s pacing. With the applications in mind, we will compare various acceleration methods, including electrostatic, gas-drag, and plasma-drag acceleration. We will also describe laboratory experiments and results on dust acceleration.

Wang, Zhehui [Los Alamos National Laboratory; Ticos, Catakin M [NILPRP, ROMANIA

2010-01-01T23:59:59.000Z

226

Molecular Hydrogen Emission from Protoplanetary Disks  

E-Print Network [OSTI]

We have modeled self-consistently the density and temperature profiles of gas and dust in protoplanetary disks, taking into account irradiation from a central star. Making use of this physical structure, we have calculated the level populations of molecular hydrogen and the line emission from the disks. As a result, we can reproduce the observed strong line spectra of molecular hydrogen from protoplanetary disks, both in the ultraviolet (UV) and the near-infrared, but only if the central star has a strong UV excess radiation.

H. Nomura; T. J. Millar

2005-05-06T23:59:59.000Z

227

Dust acoustic shock waves in two temperatures charged dusty grains  

SciTech Connect (OSTI)

The reductive perturbation method has been used to derive the Korteweg-de Vries-Burger equation and modified Korteweg-de Vries-Burger for dust acoustic shock waves in a homogeneous unmagnetized plasma having electrons, singly charged ions, hot and cold dust species with Boltzmann distributions for electrons and ions in the presence of the cold (hot) dust viscosity coefficients. The behavior of the shock waves in the dusty plasma has been investigated.

El-Shewy, E. K. [Theoretical Physics Group, Faculty of Science, Mansoura University, Mansoura (Egypt); Science and Arts College in Al-Rass, Physics Department, Qassim University, Al-Rass Province (Saudi Arabia); Abdelwahed, H. G. [Theoretical Physics Group, Faculty of Science, Mansoura University, Mansoura (Egypt); College of Science and Humanitarian Studies, Physics Department, Alkharj University, Al-kharj (Saudi Arabia); Elmessary, M. A. [Engineering Mathematics and Physics Department, Faculty of Engineering, Mansoura University, Mansoura (Egypt)

2011-11-15T23:59:59.000Z

228

CURVED WALLS: GRAIN GROWTH, SETTLING, AND COMPOSITION PATTERNS IN T TAURI DISK DUST SUBLIMATION FRONTS  

SciTech Connect (OSTI)

The dust sublimation walls of disks around T Tauri stars represent a directly observable cross-section through the disk atmosphere and midplane. Their emission properties can probe the grain size distribution and composition of the innermost regions of the disk, where terrestrial planets form. Here we calculate the inner dust sublimation wall properties for four classical T Tauri stars with a narrow range of spectral types and inclination angles and a wide range of mass accretion rates to determine the extent to which the walls are radially curved. Best fits to the near- and mid-IR excesses are found for curved, two-layer walls in which the lower layer contains larger, hotter, amorphous pyroxene grains with Mg/(Mg+Fe) = 0.6 and the upper layer contains submicron, cooler, mixed amorphous olivine and forsterite grains. As the mass accretion rates decrease from 10{sup –8} to 10{sup –10} M{sub ?} yr{sup –1}, the maximum grain size in the lower layer decreases from ?3 to 0.5 ?m. We attribute this to a decrease in fragmentation and turbulent support for micron-sized grains with decreasing viscous heating. The atmosphere of these disks is depleted of dust with dust-gas mass ratios 1 × 10{sup –4} of the interstellar medium (ISM) value, while the midplane is enhanced to eight times the ISM value. For all accretion rates, the wall contributes at least half of the flux in the optically thin 10 ?m silicate feature. Finally, we find evidence for an iron gradient in the disk, suggestive of that found in our solar system.

McClure, M. K.; Calvet, N.; Hartmann, L.; Ingleby, L. [Department of Astronomy, The University of Michigan, 500 Church Street, 830 Dennison Building., Ann Arbor, MI 48109 (United States); D'Alessio, P. [Centro de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, 58089 Morelia, Michoacán (Mexico); Espaillat, C. [Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Sargent, B. [Center for Imaging Science and Laboratory for Multiwavelength Astrophysics, Rochester Institute of Technology, 54 Lomb Memorial Drive, Rochester, NY 14623 (United States); Watson, D. M. [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States); Hernández, J., E-mail: melisma@umich.edu, E-mail: ncalvet@umich.edu, E-mail: lhartm@umich.edu, E-mail: lingleby@umich.edu, E-mail: p.dalessio@astrosmo.unam.mx, E-mail: cespaillat@cfa.harvard.edu, E-mail: baspci@rit.edu, E-mail: dmw@pas.rochester.edu, E-mail: hernandj@cida.ve [Centro de Investigaciones de Astronomía (CIDA), Mérida 5101-A (Venezuela, Bolivarian Republic of)

2013-10-01T23:59:59.000Z

229

PROBING INTERSTELLAR DUST WITH INFRARED ECHOES FROM THE Cas A SUPERNOVA  

SciTech Connect (OSTI)

We present the analysis of an Infrared Spectrograph 5-38 {mu}m spectrum and Multiband Imaging Photometer for Spitzer photometric measurements of an infrared echo near the Cassiopeia A (Cas A) supernova (SN) remnant observed with the Spitzer Space Telescope. We have modeled the recorded echo accounting for polycyclic aromatic hydrocarbons (PAHs), quantum-heated carbon and silicate grains, as well as thermal carbon and silicate particles. Using the fact that optical light-echo spectroscopy has established that Cas A originated from a Type IIb SN explosion showing an optical spectrum remarkably similar to the prototypical Type IIb SN 1993J, we use the latter to construct template data input for our simulations. We are then able to reproduce the recorded infrared echo spectrum by combining the emission of dust heated by the UV burst produced at the shock breakout after the core-collapse and dust heated by optical light emitted near the visual maximum of the SN light curve, where the UV burst and optical light curve characteristics are based on SN 1993J. We find a mean density of {approx}680 H cm{sup -3} for the echo region, with a size of a few light years across. We also find evidence of dust processing in the form of a lack of small PAHs with less than {approx}300 carbon atoms, consistent with a scenario of PAHs destruction by the UV burst via photodissociation at the estimated distance of the echo region from Cas A. Furthermore, our simulations suggest that the weak 11 {mu}m features of our recorded infrared echo spectrum are consistent with a strong dehydrogenated state of the PAHs. This exploratory study highlights the potential of investigating dust processing in the interstellar medium through infrared echoes.

Vogt, Frederic P. A. [Mount Stromlo Observatory, Research School of Astronomy and Astrophysics, The Australian National University, Cotter Road, Weston Creek, ACT 2611 (Australia); Besel, Marc-Andre; Krause, Oliver; Dullemond, Cornelis P., E-mail: fvogt@mso.anu.edu.au [Max-Planck Institut fuer Astronomie, Koenigstuhl 17, 69117 Heidelberg (Germany)

2012-05-10T23:59:59.000Z

230

aeolian dust experiment: Topics by E-print Network  

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

core relative to ambient, facilitating dust lifting by reducing the threshold wind speed for particle elevation. Finally, radial velocity profiles constructed from our...

231

Space Dust Analysis Could Provide Clues to Solar System Origins  

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

of oxygen. Isotope analysis could help confirm that the dust originated outside the solar system, but it's a process that would destroy the precious samples. For now,...

232

aeolian dust archived: Topics by E-print Network  

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

classifications of the ionizing stars to examine the role of stellar sources on dust heating and processing. Our infrared observations show surprisingly little correlation...

233

anhydrous interplanetary dust: Topics by E-print Network  

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

J. A. M. McDonnell; Kalle Bunte; Hakan Svedhem; Gerhard Drolshagen 2006-09-13 3 Fractal Signatures in Analogs of Interplanetary Dust Particles CERN Preprints Summary:...

234

adiabatic dust charge: Topics by E-print Network  

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

a transition between states. The first result Petta, Jason 12 Charging and Growth of Fractal Dust Grains CERN Preprints Summary: The structure and evolution of aggregate grains...

235

ISM dust feedback from low to high mass stars  

E-Print Network [OSTI]

The dust component of the interstellar medium (ISM) has been extensively studied in the past decades. Late-type stars have been assumed as the main source of dust to the ISM, but recent observations show that supernova remnants may play a role on the ISM dust feedback. In this work, I study the importance of low and high mass stars, as well as their evolutionary phase, on the ISM dust feedback process. I also determine the changes on the obtained results considering different mass distribution functions and star formation history. We describe a semi-empirical calculation of the relative importance of each star at each evolutionary phase in the dust ejection to the ISM. I compare the obtained results for two stellar mass distribution functions, the classic Salpeter initial mass function and the present day mass function. I used the evolutionary track models for each stellar mass, and the empirical mass-loss rates and dust-to-gas ratio. The relative contribution of each stellar mass depends on the used distribution. Ejecta from massive stars represent the most important objects for the ISM dust replenishment using the Salpeter IMF. On the other hand, for the present day mass function low and intermediate mass stars are dominant. Late-type giant and supergiant stars dominate the ISM dust feedback in our actual Galaxy, but this may not the case of galaxies experiencing high star formation rates, or at high redshifts. In those cases, SNe are dominant in the dust feedback process.

Falceta-Goncalves; D.

2007-10-26T23:59:59.000Z

236

Saving Fuel, Reducing Emissions  

E-Print Network [OSTI]

COMPACT EMISSIONS HEV PHEV marginal power plant is a coalpower uses relatively little coal, but in other cases emissions

Kammen, Daniel M.; Arons, Samuel M.; Lemoine, Derek M.; Hummel, Holmes

2009-01-01T23:59:59.000Z

237

Coal transfer: can an environmentally safe coal transfer operation be undertaken in the lower Delaware Bay. Delaware Estuary situation report. [Dusts from transport of coal from barges to colliers  

SciTech Connect (OSTI)

Effective August 1983, the U.S. Coast Guard authorized coal transfer between vessels moored in Anchorage Area A, off Big Stone Beach in lower Delaware Bay. Two general methods may be used to transfer coal from shallow-draft barges to deep-draft colliers: auger or conveyor-belt operation and clamshell operation. Although dust emission is inherent in coal transfer, best available data from similar situations indicate dust emission can vary from 0.168 pounds per ton for clamshell to 0.0024 pounds per ton for auger/conveyor transfer. Air quality and bottom water deterioration are the major potential environmental impacts.

Biggs, R.B.; Sharp, J.H.; Manus, A.T.; Wypyszinski, A.W.

1983-01-01T23:59:59.000Z

238

Measurement and modeling of the Saharan dust radiative impact: Overview of the Saharan Dust Experiment (SHADE)  

E-Print Network [OSTI]

on Climate Change (IPCC), 2001]. Among the different aerosol types, mineral dust is one of the major to their scattering and absorbing properties that affect the solar radiation, they also perturb the terrestrial but they still represent one of the largest uncer- tainties in climate change studies [Intergovernmental Panel

Highwood, Ellie

239

UNUSUAL CARBONACEOUS DUST DISTRIBUTION IN PN G095.2+00.7  

SciTech Connect (OSTI)

We investigate the polycyclic aromatic hydrocarbon (PAH) features in the young Galactic planetary nebula PN G095.2+00.7 based on mid-infrared observations. The near- to mid-infrared spectra obtained with the AKARI/IRC and the Spitzer/IRS show the PAH features as well as the broad emission feature at 12 {mu}m usually seen in proto-planetary nebulae (pPNe). The spatially resolved spectra obtained with Subaru/COMICS suggest that the broad emission around 12 {mu}m is distributed in a shell-like structure, but the unidentified infrared band at 11.3 {mu}m is selectively enhanced at the southern part of the nebula. The variation can be explained by a difference in the amount of the UV radiation to excite PAHs, and does not necessarily require the chemical processing of dust grains and PAHs. It suggests that the UV self-extinction is important to understand the mid-infrared spectral features. We propose a mechanism which accounts for the evolutionary sequence of the mid-infrared dust features seen in a transition from pPNe to PNe.

Ohsawa, Ryou; Onaka, Takashi; Sakon, Itsuki; Mori, Tamami I. [Department of Astronomy, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Miyata, Takashi; Asano, Kentaro [Institute of Astronomy, University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan); Matsuura, Mikako [Department of Physics and Astronomy, University College London, Kathleen Lonsdale Building, Gower Place, London WC1E 6BT (United Kingdom); Kaneda, Hidehiro, E-mail: ohsawa@astron.s.u-tokyo.ac.jp [Division of Particle and Astrophysical Sciences, G. Nagoya University, Chikusa-ku, Furo-cho, Nagoya 464-8602 (Japan)

2012-12-01T23:59:59.000Z

240

Paramagnetic alignment of thermally rotating dust  

E-Print Network [OSTI]

Paramagnetic alignment of thermally rotating oblate dust grains is studied analytically for finite ratios of grain to gas temperatures. For such ratios, the alignment of angular momentum J in respect to the grain axis of maximal inertia is only partial. We treat the alignment of J using perturbative methods and disentangle the problem of J alignment in grain body axes from that of J alignment in respect to magnetic field. This enables us to find the alignment of grain axes to magnetic field and thus relate our theory to polarimetric observations.Our present results are applicable to the alignment of both paramagnetic and superparamagnetic grains.

A. Lazarian

1997-02-16T23:59:59.000Z

Note: This page contains sample records for the topic "fugitive dust emissions" 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

ARM - PI Product - Niamey Dust Observations  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc Documentation RUC : XDCResearchWarmingMethaneProductsCSSEFProductsMerged andAerosol OpticalDust

242

DOE/El%0297 Dust. Category  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed Newcatalyst phases onOrganizationElectronic Reading2Q)382 THE HUMANlviA,'{ '297 Dust.

243

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

SciTech Connect (OSTI)

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

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

2013-08-15T23:59:59.000Z

244

Performance characteristics of PM??? samplers in the presence of agricultural dusts  

E-Print Network [OSTI]

, these samplers are not tested in the presence of agriculture dusts, which have a larger mass median diameter (MMD) than urban dusts. This research addressed the performance characteristics of PM??? samplers in the presence of agricultural dusts. Tests in a...

Pargmann, Amber Rae

2001-01-01T23:59:59.000Z

245

Radiative Effects of Dust Aerosols, Natural Cirrus Clouds and Contrails: Broadband Optical Properties and Sensitivity Studies  

E-Print Network [OSTI]

This dissertation aims to study the broadband optical properties and radiative effects of dust aerosols and ice clouds. It covers three main topics: the uncertainty of dust optical properties and radiative effects from the dust particle shape...

Yi, Bingqi

2013-07-09T23:59:59.000Z

246

ANALYSIS OF DUST DELIQUESCENCE FOR FEP SCREENING  

SciTech Connect (OSTI)

The purpose of this report is to evaluate the potential for penetration of the Alloy 22 (UNS N06022) waste package outer barrier by localized corrosion due to the deliquescence of soluble constituents in dust present on waste package surfaces. The results support a recommendation to exclude deliquescence-induced localized corrosion (pitting or crevice corrosion) of the outer barrier from the total system performance assessment for the license application (TSPA-LA). Preparation of this report, and supporting laboratory studies and calculations, were performed as part of the planned effort in Work Package AEBM21, as implemented in ''Technical Work Plan for: Screening Evaluation for Dust Deliquescence and Localized Corrosion'' (BSC 2004 [DIRS 172804]), by Bechtel SAIC Company, LLC, and staff from three national laboratories: Sandia National Laboratories, Lawrence Livermore National Laboratory (LLNL), and Lawrence Berkeley National Laboratory (LBNL). The analysis and conclusions presented in this report are quality affecting, as determined in the controlling technical work plan. A summary of background information, based on work that was not performed under a quality assurance program, is provided as Appendix E. In this instance, the use of unqualified information is provided for transparency and corroboration only, and is clearly separated from uses of qualified information. Thus, the qualification status of this information does not affect the conclusions of this report. The acceptance criteria addressed in Sections 4.2 and 7.2 were changed from the technical work plan in response to review comments received during preparation of this report.

C. Bryan

2005-08-26T23:59:59.000Z

247

Constraining oceanic dust deposition using surface ocean dissolved Al  

E-Print Network [OSTI]

Constraining oceanic dust deposition using surface ocean dissolved Al Qin Han,1 J. Keith Moore,1; accepted 7 December 2007; published 12 April 2008. [1] We use measurements of ocean surface dissolved Al (DEAD) model to constrain dust deposition to the oceans. Our Al database contains all available

Zender, Charles

248

Dynamics of Finite Dust Clouds in a Magnetized Anodic Plasma  

SciTech Connect (OSTI)

The response to an external modulation voltage of small dust clouds confined in an anodic plasma is studied. Dust density waves are excited when the cloud is larger than a wavelength, whereas a sloshing and stretching motion is found for smaller clouds. The wave dispersion shows similarities with waveguide modes.

Piel, A.; Pilch, I.; Trottenberg, T. [Institute for Experimental and Applied Physics, Christian-Albrechts University, D-24098 Kiel (Germany); Koepke, M. E. [Department of Physics, West Virginia University, Morgantown, West Virginia 26505-6315 (United States)

2008-09-07T23:59:59.000Z

249

E-Print Network 3.0 - aluminum dust explosion Sample Search Results  

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

retention Explosion with air 100 Tungsten Activation 100-400 Dust... of traditional plasma diagnostics. Who has resources, time to tackle it ? 12;Dust diagnostics in ITER ?...

250

E-Print Network 3.0 - abrasive dusts avaliacao Sample Search...  

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

field observations indicate that dust production occurs via self-abrasion... , dust production reportedly occurred by a "self-abrasion" process of saltating diatomite flakes,...

251

Continuous particulate monitoring for emission control  

SciTech Connect (OSTI)

An optical continuous particle monitoring system has been developed to overcome common problems associated with emissions monitoring equipment. Opacity monitors generally use a single- or double-pass system to analyze the presence of dust particles in the flue gas stream. The particles scatter and absorb light as it passes through the stack. As the particle content in the gas stream increases due to bag failure or some other problem, the amount of light that is blocked also increases. The opacity monitor compares the amount of lost light energy to the total energy of the light available and translates the signal to percentage of opacity. Opacity monitors are typically installed to meet the requirements set forth by pollution control agencies. Most opacity monitors are designed to meet all of the requirements of the Environmental Protection Agency (EPA) 40 CFR, Part 60, Appendix B, Performance Specification. The new continuous particle monitor (CPM) increases the accuracy of emission monitoring and overcomes typical problems found in conventional emission monitoring devices. The CPM is an optically based, calibratible, continuous dust monitor that uses a microprocessor, transmitter head, and receiver head. When calibrated with an isokinetic sample, a continuous readout of particulate concentration (in mg/m[sup 3]) in the exhaust gas is provided. The system can be used as a filter bag failure system or a long-term emission trend analyzer. Formal testing was conducted to evaluate the effectiveness of the optically based CPM. The monitor was calibrated using particles of a range of compositions, size distributions, and concentrations. The feasibility of using the instrument to measure particle concentration as low as 10 mg/m[sup 3] was examined.

Bock, A.H. (BHA Group, Inc., Kansas City, MO (United States))

1993-08-01T23:59:59.000Z

252

Radionuclide Air Emissions Report for the Hanford Site Calendar year 1998  

SciTech Connect (OSTI)

This report documents radionuclide air emissions from the Hanford Site in I998 and the resulting effective dose equivalent to the maximally exposed individual (MEI) member of the public. The report has been prepared in accordance with the Code of Federal Regulations, Title 40, Protection of the Environment, Part 61, National Emission Standards for Hazardous Air Pollutants (40 CFR SI), Subpart H, ''National Emission Standards for Emissions of Radionuclides Other than Radon from Department of Energy Facilities,'' and with the Washington Administrative Code Chapter 246-247, Radiation Protection--Air Emissions. The federal regulations in 40 CFR 61, Subpart H; require the measurement and reporting of radionuclides emitted from Department of Energy facilities and the resulting offsite dose from those emissions. A standard of 10 mrem/yr effective dose equivalent (EDE) is imposed on them. The EDE to the MEI due to routine emissions in 1998 from Hanford Site point sources was 1.3 E-02 mrem (1.3 E-04 mSv), which is 0.13 percent of the federal standard. Chapter 246-247 of the Washington Administrative Code (WAC) requires the reporting of radionuclide emissions from all Department of Energy Hanford Site sources. The state has adopted into these regulations the 40 CFR 61 standard of 10 mrem/yr EDE. The EDE to the MEI attributable to diffuse and fugitive radionuclide air emissions from the Hanford Site in 1998 was 2.5 E-02 mrem (2.5 E-04 mSv). This dose added to the dose from point sources gives a total for all sources of 3.8 E-02 mrem/yr (3.8 E-04 mSv) EDE, which is 0.38 percent of the 10 mrem/yr standard. An unplanned release on August 26, 1998, in the 300 Area of the Hanford Site resulted in a potential dose of 4.1 E-02 mrem to a hypothetical individual at the nearest point of public access to that area. This hypothetical individual was not the MEI since the wind direction on the day of the release was away from the MEI residence. The potential dose from the unplanned event was similar in magnitude to that from routine releases during 1998. Were the release from this unplanned event combined with routine releases, the total dose would be less than 1 percent ofthe 10 mrem/yr standard.

DIEDIKER, L.P.

1999-06-15T23:59:59.000Z

253

Processing electric arc furnace dust into saleable chemical products  

SciTech Connect (OSTI)

The modern steel industry uses electric arc furnace (EAF) technology to manufacture steel. A major drawback of this technology is the production of EAF dust, which is listed by the U.S. Environmental Protection Agency as a hazardous waste under the Resource Conservation and Recovery Act. The annual disposal of approximately 0.65 million tons of EAF dust in the United States and Canada is an expensive, unresolved problem for the steel industry. EAF dust byproducts are generated during the manufacturing process by a variety of mechanisms. The dust consists of various metals (e.g., zinc, lead, cadmium) that occur as vapors at 1,600{degrees}C (EAF hearth temperature); these vapors are condensed and collected in a baghouse. The production of one ton of steel will generate approximately 25 pounds of EAF dust as a byproduct, which is currently disposed of in landfills.

NONE

1998-04-01T23:59:59.000Z

254

Existence domains of dust-acoustic solitons and supersolitons  

SciTech Connect (OSTI)

Using the Sagdeev potential method, the existence of large amplitude dust-acoustic solitons and supersolitons is investigated in a plasma comprising cold negative dust, adiabatic positive dust, Boltzmann electrons, and non-thermal ions. This model supports the existence of positive potential supersolitons in a certain region in parameter space in addition to regular solitons having negative and positive potentials. The lower Mach number limit for supersolitons coincides with the occurrence of double layers whereas the upper limit is imposed by the constraint that the adiabatic positive dust number density must remain real valued. The upper Mach number limits for negative potential (positive potential) solitons coincide with limiting values of the negative (positive) potential for which the negative (positive) dust number density is real valued. Alternatively, the existence of positive potential solitons can terminate when positive potential double layers occur.

Maharaj, S. K. [South African National Space Agency (SANSA) Space Science, PO Box 32, Hermanus 7200 (South Africa)] [South African National Space Agency (SANSA) Space Science, PO Box 32, Hermanus 7200 (South Africa); Bharuthram, R. [University of the Western Cape, Robert Sobukwe Road, Bellville 7535 (South Africa)] [University of the Western Cape, Robert Sobukwe Road, Bellville 7535 (South Africa); Singh, S. V.; Lakhina, G. S. [Indian Institute of Geomagnetism, New Panvel, Navi Mumbai 410218 (India)] [Indian Institute of Geomagnetism, New Panvel, Navi Mumbai 410218 (India)

2013-08-15T23:59:59.000Z

255

Sheath formation under collisional conditions in presence of dust  

SciTech Connect (OSTI)

Sheath formation is studied for collisional plasma in presence of dust. In common laboratory plasma, the dust acquires negative charges because of high thermal velocity of the electrons. The usual dust charging theory dealing with the issue is that of the Orbit Motion Limited theory. However, the theory does not find its application when the ion neutral collisions are significantly present. An alternate theory exists in literature for collisional dust charging. Collision is modeled by constant mean free path model. The sheath is considered jointly with the bulk of the plasma and a smooth transition of the plasma profiles from the bulk to the sheath is obtained. The various plasma profiles such as the electrostatic force on the grain, the ion drag force along with the dust density, and velocity are shown to vary spatially with increasing ion neutral collision.

Moulick, R., E-mail: rakesh.moulick@gmail.com; Goswami, K. S. [Centre of Plasma Physics-Institute for Plasma Research, Sonapur-782402, Guwahati (India)

2014-08-15T23:59:59.000Z

256

Control of metal dusting corrosion in Ni-base alloys.  

SciTech Connect (OSTI)

Metal dusting is a major issue in plants used in the production of hydrogen-and methanol-reformer systems, and syngas (H{sub 2}/CO mixtures) systems that are pertinent to the chemical and petrochemical industries. Usually, metal dusting corrosion has two stages: incubation and growth resulting in propagation of metal dusting pits. The two stages were studied by scanning electron microscopy and profile mapping to evaluate the scale of the surface oxide in the initiation and propagation of metal dusting attack. The initiation occurs because of the presence of defects, and the propagation is determined by the diffusion of carbon into the alloy. The carbon diffusion pathways can be blocked by periodically oxidizing alloy surface at moderate temperatures in controlled atmospheres. It was concluded that metal dusting degradation can be mitigated by selecting an alloy with a long incubation time and subjecting it to intermediate oxidation.

Zeng, Z.; Natesan, K.; Energy Technology

2007-11-01T23:59:59.000Z

257

The Heating of Mid-Infrared Dust in the Nearby Galaxy M33: A Testbed for Tracing Galaxy Evolution  

E-Print Network [OSTI]

Because the 8 {\\mu}m polycyclic aromatic hydrocarbon (PAH) emission has been found to correlate with other well-known star formation tracers, it has widely been used as a star formation rate (SFR) tracer. There are, however, studies that challenge the accuracy and reliability of the 8 {\\mu}m emission as a SFR tracer. Our study, part of the Herschel M33 Extended Survey (HERM33ES) open time key program, aims at addressing this issue by analyzing the infrared emission from the nearby spiral galaxy M33 at the high spatial scale of 75 pc. Combining data from the Herschel Space Observatory and the Spitzer Space Telescope we find that the 8 {\\mu}m emission is better correlated with the 250 {\\mu}m emission, which traces cold interstellar gas, than with the 24 {\\mu}m emission. The L(8)/L(24) ratio is highly depressed in 24 {\\mu}m luminous regions, which correlate with known HII regions. We also compare our results with the dust emission models by Draine & Li (2007). We confirm that the depression of 8 {\\mu}m PAH e...

Calapa, M; Draine, B T; Boquien, M; Kramer, C; Xilouris, M; Verley, S; Braine, J; Relaño-Pastor, M; van der Werf, P; Israel, F; Hermelo, I; Albrecht, M

2014-01-01T23:59:59.000Z

258

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

E-Print Network [OSTI]

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

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

2006-06-14T23:59:59.000Z

259

A dual emission mechanism in Sgr A*/L' ?  

E-Print Network [OSTI]

We have collected in 2004 adaptive optics corrected L' images of the Galactic Center region with NAOS-CONICA at VLT. A strong variability was observed as well as a correlation between the photocenter positions and fluxes of the L'-band counterpart of Sgr A*. It is interpreted as the combined emission of a point-like flaring source at the position of Sgr A*/IR itself and an extended dust structure, 75 mas south west of Sgr A*/IR, which we name Sgr A*-f. We examine the different possible mechanisms to explain this dual Sgr A* L' emission and conclude it is likely a flaring emission associated to energetic events in the close environment of the black hole plus a quiescent emission resulting from the collision of Sgr A*-f by a jet from Sgr A*.

Yann Clénet; Daniel Rouan; Damien Gratadour; Olivier Marco; Pierre Léna; Nancy Ageorges; Eric Gendron

2005-07-05T23:59:59.000Z

260

THE S{sup 4}G PERSPECTIVE ON CIRCUMSTELLAR DUST EXTINCTION OF ASYMPTOTIC GIANT BRANCH STARS IN M100  

SciTech Connect (OSTI)

We examine the effect of circumstellar dust extinction on the near-IR (NIR) contribution of asymptotic giant branch (AGB) stars in intermediate-age clusters throughout the disk of M100. For our sample of 17 AGB-dominated clusters we extract optical-to-mid-IR spectral energy distributions (SEDs) and find that NIR brightness is coupled to the mid-IR dust emission in such a way that a significant reduction of AGB light, of up to 1 mag in the K band, follows from extinction by the dust shell formed during this stage. Since the dust optical depth varies with AGB chemistry (C-rich or O-rich), our results suggest that the contribution of AGB stars to the flux from their host clusters will be closely linked to the metallicity and the progenitor mass of the AGB star, to which dust chemistry and mass-loss rate are sensitive. Our sample of clusters-each the analogue of a {approx}1 Gyr old post-starburst galaxy-has implications within the context of mass and age estimation via SED modeling at high-z: we find that the average {approx}0.5 mag extinction estimated here may be sufficient to reduce the AGB contribution in the (rest-frame) K band from {approx}70%, as predicted in the latest generation of synthesis models, to {approx}35%. Our technique for selecting AGB-dominated clusters in nearby galaxies promises to be effective for discriminating the uncertainties associated with AGB stars in intermediate-age populations that plague age and mass estimation in high-z galaxies.

Meidt, Sharon E.; Schinnerer, Eva [Max-Planck-Institut fuer Astronomie/Koenigstuhl 17, D-69117 Heidelberg (Germany); Munoz-Mateos, Juan-Carlos; Kim, Taehyun [National Radio Astronomy Observatory, Charlottesville, VA (United States); Holwerda, Benne [European Space Agency, ESTEC, Keplerlaan 1, 2200 AG, Noordwijk (Netherlands); Ho, Luis C.; Madore, Barry F.; Sheth, Kartik; Menendez-Delmestre, Karin; Seibert, Mark [The Observatories of the Carnegie Institution for Science, Pasadena, CA (United States); Knapen, Johan H. [Instituto de Astrofisica de Canarias, Tenerife (Spain); Bosma, Albert; Athanassoula, E. [Laboratoire d'Astrophysique de Marseille (LAM), Marseille (France); Hinz, Joannah L. [Department of Astronomy, University of Arizona, Tucson, AZ (United States); Regan, Michael [Space Telescope Science Institute, Baltimore, MD (United States); De Paz, Armando Gil [Departamento de Astrofisica, Universidad Complutense Madrid, Madrid (Spain); Mizusawa, Trisha [Spitzer Science Center, Pasadena, CA (United States); Gadotti, Dimitri A. [European Southern Observatory, Santiago (Chile); Laurikainen, Eija; Salo, Heikki [Astronomy Division, Department of Physical Sciences, University of Oulu, Oulu (Finland); and others

2012-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "fugitive dust emissions" 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

E-Print Network 3.0 - airborne occupational exposure Sample Search...  

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

Airborne Emissions . . . 8... -6 9-3. Normalized Impacts from One Year of Exposure to Fugitive Airborne Emissions . . ... Source: Yucca Mountain Project, US EPA Collection:...

262

International Council for Local Environmental Initiatives (ICLEI...  

Open Energy Info (EERE)

fire suppression equipment, and power generation; solid waste emissions; wastewater treatment facilities; and other process and fugitive emissions), scope 2 (purchased...

263

Ordered dust structures in a glow discharge  

SciTech Connect (OSTI)

Highly ordered three-dimensional dust structures are created in a striated glow discharge, and their horizontal cross-sectional images are analyzed. Calculated correlation functions, local correlation parameters, and corresponding approximations are used to classify the state of a structure according to the Kosterlitz-Thouless-Halperin-Nelson-Young (KTHNY) two-dimensional melting theory and a phenomenological approach. An orientational map based on an orientational parameter is proposed to expose domains in a cross section of a structure. It is shown that a plasma crystal is a polycrystal consisting of hexagonal domains (crystallites). Thermophoretic forces are used to create corners of various angles in the perimeter of the structure. Transition between hexagonal and square cell shapes is observed.

Karasev, V. Yu., E-mail: plasmadust@yandex.ru; Ivanov, A. Yu.; Dzlieva, E. S.; Eikhval'd, A. I. [St. Petersburg State University, Institute of Physics (Russian Federation)

2008-02-15T23:59:59.000Z

264

A new method to generate dust with astrophysical properties  

SciTech Connect (OSTI)

In interstellar and interplanetary space, the size distribution and composition of dust grains play an important role. For example, dust grains determine optical and ultraviolet extinction levels in astronomical observations, dominate the cooling rate of our Galaxy, and sets the thermal balance and radiative cooling rates in molecular clouds, which are the birth place of stars. Dust grains are also a source of damage and failure to space hardware and thus present a hazard to space flight. To model the size distribution and composition of dust grains, and their effect in the above scenarios, it is vital to understand the mechanism of dust-shock interaction. We demonstrate a new experiment which employs a laser to subject dust grains to pressure spikes similar to those of colliding astrophysical dust, and which accelerates the grains to astrophysical velocities. The new method generates much larger data sets than earlier methods; we show how large quantities (thousands) of grains are accelerated at once, rather than accelerating individual grains, as is the case of earlier methods using electric fields.

Hansen, J F; van Breugel, W; Bringa, E M; Graham, G A; Remington, B A; Taylor, E A; Tielens, A G

2010-04-21T23:59:59.000Z

265

Controlling Silver Dust and Fumes at Mine Refinery  

E-Print Network [OSTI]

ABSTRACT: As part of the refining of gold and silver molten metal, silver dust and fumes are released into the atmosphere. The Mine Safety and Health Administration (MSHA) enforces an 8-hour, equivalent Time Weighted Average concentration limit for silver dust and fumes of 10 µg/m 3. MSHA initiated a program to assess the controls that were being used to control silver dust and fume exposure. Refineries were visited at six mines. The layout of each refinery and the controls used varied at each refinery. At each operation, personal and area silver fume and dust samples were collected to assess worker exposures and to determine sources of fume. Primary source of silver dust and fume exposure was the pouring of molten metal from the furnace. Secondary sources of exposure included: precipitate mixing, bar cooling, and housekeeping. Guidelines were developed addressing housekeeping, exhaust ventilation, general ventilation, administrative controls, and system monitoring. In most cases, housekeeping and general ventilation were adequate; however, the exhaust ventilation systems needed to be improved. 1 INRODUCTION Silver dust and fumes become airborne during the refining step of producing gold and silver. The dust

R. A. Haney; M. P. Valoski

266

Vehicle Emissions Review - 2011  

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

Emissions Review - 2011 (so far) Tim Johnson October 4, 2011 DOE DEER Conference, Detroit JohnsonTV@Corning.com 2 Summary * California LD criteria emission regs are tightening....

267

Spatiotemporal evolution of dielectric driven cogenerated dust density waves  

SciTech Connect (OSTI)

An experimental observation of spatiotemporal evolution of dust density waves (DDWs) in cogenerated dusty plasma in the presence of modified field induced by glass plate is reported. Various DDWs, such as vertical, oblique, and stationary, were detected simultaneously for the first time. Evolution of spatiotemporal complexity like bifurcation in propagating wavefronts is also observed. As dust concentration reaches extremely high value, the DDW collapses. Also, the oblique and nonpropagating mode vanishes when we increase the number of glass plates, while dust particles were trapped above each glass plates showing only vertical DDWs.

Sarkar, Sanjib; Bose, M. [Department of Physics, Jadavpur University, Kolkata 700032 (India)] [Department of Physics, Jadavpur University, Kolkata 700032 (India); Mukherjee, S. [FCIPT, Institute for Plasma Research, Gandhinagar 382428 (India)] [FCIPT, Institute for Plasma Research, Gandhinagar 382428 (India); Pramanik, J. [Kharagpur College, Kharagpur 721305, West Bengal (India)] [Kharagpur College, Kharagpur 721305, West Bengal (India)

2013-06-15T23:59:59.000Z

268

Heterogeneous Chemistry of Individual Mineral Dust Particles from Different Dust Source Regions: The Importance of Particle Mineralogy  

SciTech Connect (OSTI)

The heterogeneous chemistry of individual dust particles from four different dust source regions is investigated on a particle-by-particle basis using state-of-the-art scanning electron microscopy techniques including computer-controlled scanning electron microscopy/computer-controlled X-ray analysis (CCSEM/EDX). Morphology and compositional changes of individual particles as they react with nitric acid are observed. Clear differences in the reactivity of mineral dusts from these four different dust regions with nitric acid could be observed. Mineral dust from source regions containing high levels of calcium, such as those found in parts of China and Saudi Arabia, are found to react to the greatest extent. Calcium containing minerals, such as calcite (CaCO3) and dolomite (CaMg(CO3)2), react to form nitrate salt whereas other calcium containing minerals such as gypsum (CaSO4?2H2O) do not react. The importance of particle chemical composition and mineralogy in the heterogeneous chemistry of mineral dust aerosols is definitively borne out in this study of individual dust particles.

Krueger, Brenda J.; Grassian, Vicki H.; Cowin, James P.; Laskin, Alexander

2004-11-01T23:59:59.000Z

269

Onsite recycling of electric arc furnace dust: The Jorgensen Steel Facility  

SciTech Connect (OSTI)

The steel-making industry produces a large amount of Electric Arc Furnace (EAF) dust as part of normal production. This waste is listed as KO61, defined as {open_quotes}emission control dust/sludge from the primary production of steel in electric arc furnaces{close_quotes} under 40 CFR 261.32. A glass making technology called Ek Glassification{trademark} (hereafter called {open_quotes}the Process{close_quotes}) has been developed by Roger B. Ek and Associates, Inc. (hereafter called {open_quotes}the Developer{close_quotes}) to recycle EAF dust and convert it, along with other byproducts of the steel-making industry, into marketable commodities. This Process was evaluated under the Waste Reduction Innovative Technology Evaluation (WRITE) Program. The project was designed and conducted in cooperation with the Washington State Department of Environmental Quality, the Process Developer and the host test site, the Earle M. Jorgensen (EMJ) Steel Company of Seattle, Washington. Test personnel for EPA were supplied by SAIC Inc., on contract to EPA. The overall objectives of the project were to conduct a pilot scale evaluation of the Process, investigate if toxic metals are leached from the products (such as colored glass and glass-ceramics; ceramic glazes, colorants, and fillers; roofing granules and sand-blasting grit; and materials for Portland cement production). Three glass recipes (Glass I, II, and III) were designed by the developer for potential use at EMJ. The EPA portion was focused on determining the toxic metals concentrations of the Glass II recipe, evaluating the P2 impact of using this Process in comparison to traditional methods of waste treatment and disposal, and assessing the economics of both.

Licis, I.J. [Environmental Protection Agency, Cincinnati, OH (United States); Bermark, R.C. [Washington State Dept. of Ecology, Olympia, WA (United States)

1995-10-01T23:59:59.000Z

270

Excitation of dust acoustic waves by an ion beam in a plasma cylinder with negatively charged dust grains  

SciTech Connect (OSTI)

An ion beam propagating through a plasma cylinder having negatively charged dust grains drives a low frequency electrostatic dust acoustic wave (DAW) to instability via Cerenkov interaction. The unstable wave frequencies and the growth rate increase with the relative density of negatively charged dust grains. The growth rate of the unstable mode scales to the one-third power of the beam density. The real part of the frequency of the unstable mode increases with the beam energy and scales to almost one-half power of the beam energy. The phase velocity, frequency, and wavelength results of the unstable mode are in compliance with the experimental observations.

Sharma, Suresh C. [Department of Applied Physics, Delhi Technological University (DTU), Shahbad Daulatpur, Bawana Road, Delhi-42 (India); Kaur, Daljeet [Department of Physics, Guru Teg Bahadur Institute of Technology, Rajouri Garden, New Delhi (India); Gahlot, Ajay [Department of Physics, Maharaja Surajmal Institute of Technology, Janakpuri, New Delhi (India); Sharma, Jyotsna [Department of Physics, KIIT College of Engineering, Bhondsi Gurgaon 122102 (India)

2014-10-15T23:59:59.000Z

271

Magnetorotational instability in plasmas with mobile dust grains  

SciTech Connect (OSTI)

The magnetorotational instability of dusty plasmas is investigated using the multi-fluid model and the general dispersion relation is derived based on local approximation. The dust grains are found to play an important role in the dispersion relation in the low-frequency mode and exhibit destabilizing effects on the plasma. Both the instability criterion and growth rate are affected significantly by the dust and when the dust is heavy enough to be unperturbed, the reduced dispersion relations are obtained. The instability criteria show that the dust grains have stabilizing effects on the instability when the rotation frequency decreases outwards and conversely lead to destabilizing effects when the rotation frequency increases outwards. The results are relevant to accession and protoplanetary disks.

Ren Haijun [CAS Key Laboratory of Basic Plasma Physics, Department of Modern Physics, University of Science and Technology of China, Hefei 230026 (China); Cao Jintao [Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Li Ding [CAS Key Laboratory of Basic Plasma Physics, Department of Modern Physics, University of Science and Technology of China, Hefei 230026 (China); Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Chu, Paul K. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong)

2013-03-15T23:59:59.000Z

272

Global trends in visibility: implications for dust sources  

E-Print Network [OSTI]

There is a large uncertainty in the relative roles of human land use, climate change and carbon dioxide fertilization in changing desert dust source strength over the past 100 years, and the overall sign of human impacts ...

Mahowald, N. M.; Ballantine, J.A.; Feddema, Johannes J.; Ramankutty, N.

2007-06-01T23:59:59.000Z

273

african dust measured: Topics by E-print Network  

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

swath of the HiRISE instrument has three separate charge-coupled devices (CCDs) and color filters that observe the surface in rapid cadence. Active features, such as dust devils,...

274

Dust-shell Universe in the modified gravity scenario  

E-Print Network [OSTI]

The dynamics of the dust-shell model of universe is exactly solved for the modified Schwarzschild solution. This solution is used to derive the cosmology corresponding to the modified gravity.

Michael Maziashvili

2005-04-15T23:59:59.000Z

275

The Photophysics of the Carrier of Extended Red Emission  

E-Print Network [OSTI]

Interstellar dust contains a component which reveals its presence by emitting a broad, unstructured band of light in the 540 to 950 nm wavelength range, referred to as Extended Red Emission (ERE). The presence of interstellar dust and ultraviolet photons are two necessary conditions for ERE to occur. This is the basis for suggestions which attribute ERE to an interstellar dust component capable of photoluminescence. In this study, we have collected all published ERE observations with absolute-calibrated spectra for interstellar environments, where the density of ultraviolet photons can be estimated reliably. In each case, we determined the band-integrated ERE intensity, the wavelength of peak emission in the ERE band, and the efficiency with which absorbed ultraviolet photons are contributing to the ERE. The data show that radiation is not only driving the ERE, as expected for a photoluminescence process, but is modifying the ERE carrier as manifested by a systematic increase in the ERE band's peak wavelength and a general decrease in the photon conversion efficiency with increasing densities of the prevailing exciting radiation. The overall spectral characteristics of the ERE and the observed high quantum efficiency of the ERE process are currently best matched by the recently proposed silicon nanoparticle (SNP) model. Using the experimentally established fact that ionization of semiconductor nanoparticles quenches their photoluminescence, we proceeded to test the SNP model by developing a quantitative model for the excitation and ionization equilibrium of SNPs under interstellar conditions for a wide range of radiation field densities.

Tracy L. Smith; Adolf N. Witt

2001-09-26T23:59:59.000Z

276

Dust Plume Modeling from Ranges and Maneuver Areas on Fort Bliss and the White Sands Missile Range: Final Report  

SciTech Connect (OSTI)

The potential for air quality impacts from heavy mechanized vehicles operating on and between the unpaved main supply routes at Fort Bliss and White Sands Missile Range was investigated. This report details efforts by the staff of Pacific Northwest National Laboratory for the Fort Bliss Directorate of Environment in this investigation. Dust emission and dispersion from typical move-out activities occurring on the installations were simulated using the atmospheric modeling system DUSTRAN. Major assumptions associated with designing the modeling scenarios are summarized and results of simulations conducted under these assumptions are presented for four representative meteorological periods.

Chapman, Elaine G.; Barnard, James C.; Rutz, Frederick C.; Pekour, Mikhail S.; Rishel, Jeremy P.; Shaw, William J.

2009-05-04T23:59:59.000Z

277

The response of a capacitively coupled discharge to the formation of dust particles: Experiments and modeling  

SciTech Connect (OSTI)

The influence of dust particles on the properties of a capacitively coupled Ar-C{sub 2}H{sub 2} discharge is studied both experimentally and theoretically. The results of measurements of the intensity and spatial distribution of the emitted light, the line width of the fast component of H{sub {alpha}} line and of the electron density during the particle growth are presented. To analyze the experimental results a one-dimensional discharge model is developed. Using the model the effects of dust grains on the power absorption (taking into account stochastic and Ohmic heating in the plasma sheaths), the optical emission intensity profile, the sheath size, the rf electric field and on the energy of positive ions bombarding the electrodes are investigated. In particular, it is shown that the decrease of the power absorption in the sheaths of complex plasmas is due to the dependence of the stochastic and Ohmic heating in the plasma sheaths on the electron temperature and the current flowing across the discharge plates. The results of the calculations are compared with the available experimental data and found to be in good agreement.

Denysenko, I.; Berndt, J.; Kovacevic, E.; Stefanovic, I.; Selenin, V.; Winter, J. [School of Physics and Technology, V. N. Karazin Kharkiv National University, Svobody sq. 4, 61077 Kharkiv (Ukraine); Institute of Experimental Physics II, Ruhr-University Bochum, D-44780 Bochum (Germany); Institute of Experimental Physics II, Ruhr-University Bochum, D-44780 Bochum, Germany and Institute of Physics, POB 57, 11001 Belgrade (Serbia and Montenegro); Institute of Experimental Physics II, Ruhr-University Bochum, D-44780 Bochum (Germany)

2006-07-15T23:59:59.000Z

278

X-ray Dust Scattering at Small Angles: The Complete Halo around GX13+1  

E-Print Network [OSTI]

The exquisite angular resolution available with Chandra should allow precision measurements of faint diffuse emission surrounding bright sources, such as the X-ray scattering halos created by interstellar dust. However, the ACIS CCDs suffer from pileup when observing bright sources, and this creates difficulties when trying to extract the scattered halo near the source. The initial study of the X-ray halo around GX13+1 using only the ACIS-I detector done by Smith, Edgar & Shafer (2002) suffered from a lack of sensitivity within 50'' of the source, limiting what conclusions could be drawn. To address this problem, observations of GX13+1 were obtained with the Chandra HRC-I and simultaneously with the RXTE PCA. Combined with the existing ACIS-I data, this allowed measurements of the X-ray halo between 2-1000''. After considering a range of dust models, each assumed to be smoothly distributed with or without a dense cloud along the line of sight, the results show that there is no evidence in this data for a dense cloud near the source, as suggested by Xiang et al. (2005). Finally, although no model leads to formally acceptable results, the Weingartner & Draine (2001) and nearly all of the composite grain models from Zubko, Dwek & Arendt (2004) give poor fits.

Randall K. Smith

2008-05-04T23:59:59.000Z

279

Probing dynamical processes in the planet forming region with dust mineralogy  

E-Print Network [OSTI]

We present Herschel Space Observatory PACS spectra of GQ Lup, a protoplanetary disk in the Lupus star-forming region. Through SED fitting from 0.3{\\mu}m to 1.3mm, we construct a self-consistent model of this system's temperature and density structures, finding that although it is 3 Myr old, its dust has not settled to the midplane substantially. The disk has a radial gradient in both the silicate dust composition and grain size, with large amorphous grains in the upper layers of the inner disk and an enhancement of submicron, crystalline grains in the outer disk. We detect an excess of emission in the Herschel PACS B2A band near 63{\\mu}m and model it with a combination of {\\sim}15 to 70{\\mu}m crystalline water ice grains with a size distribution consistent with ice recondensation-enhanced grain growth and a mass fraction half of that of our solar system. The combination of crystalline water ice and silicates in the outer disk is suggestive of disk-wide heating events or planetesimal collisions. If confirmed, ...

McClure, M K; Calvet, N; Adame, L; Espaillat, C; Watson, D M; Sargent, B; Forrest, W J; D'Alessio, P

2012-01-01T23:59:59.000Z

280

Dust size distribution and concentrations with cottonseed oil mills  

E-Print Network [OSTI]

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

Wiederhold, Lee Roy

1976-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fugitive dust emissions" 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

Extraplanar Dust in Spiral Galaxies: Observations and Implications  

E-Print Network [OSTI]

Recent optical and submillimeter observations have begun to probe the existence of dust grains in the halos of spiral galaxies. I review our own work in this area which employs high-resolution optical images of edge-on spiral galaxies to trace high-z dust in absorption against the background stellar light of the galaxies. We have found that a substantial fraction of such galaxies (>50%) show extensive webs of dust-bearing clouds to heights z>2 kpc. Extraplanar dust in galaxies is statistically correlated with extraplanar diffuse ionized gas, though there is no evidence for a direct, physical relationship between these two phases of the high-z interstellar medium. The dense high-z clouds individually have masses estimated to be >10^5} to 10^6 solar masses. The detailed properties of the observed dust structures suggest the clouds seen in our images may represent the dense phase of a multiphase ISM at high-z. Such dense clouds can have an important effect on the observed light distribution in spiral galaxies. I discuss the effects such high-z dust can have on quantitative measures of the vertical structure of stars and ionized gas in edge-on systems.

J. Christopher Howk

1999-10-05T23:59:59.000Z

282

HTGR Dust Safety Issues and Needs for Research and Development  

SciTech Connect (OSTI)

This report presents a summary of high temperature gas-cooled reactor dust safety issues. It draws upon a literature review and the proceedings of the Very High Temperature Reactor Dust Assessment Meeting held in Rockville, MD in March 2011 to identify and prioritize the phenomena and issues that characterize the effect of carbonaceous dust on high temperature reactor safety. It reflects the work and input of approximately 40 participants from the U.S. Department of Energy and its National Labs, the U.S. Nuclear Regulatory Commission, industry, academia, and international nuclear research organizations on the topics of dust generation and characterization, transport, fission product interactions, and chemical reactions. The meeting was organized by the Idaho National Laboratory under the auspices of the Next Generation Nuclear Plant Project, with support from the U.S. Nuclear Regulatory Commission. Information gleaned from the report and related meetings will be used to enhance the fuel, graphite, and methods technical program plans that guide research and development under the Next Generation Nuclear Plant Project. Based on meeting discussions and presentations, major research and development needs include: generating adsorption isotherms for fission products that display an affinity for dust, investigating the formation and properties of carbonaceous crust on the inside of high temperature reactor coolant pipes, and confirming the predominant source of dust as abrasion between fuel spheres and the fuel handling system.

Paul W. Humrickhouse

2011-06-01T23:59:59.000Z

283

Understanding environmental leachability of electric arc furnace dust  

SciTech Connect (OSTI)

Dust from production of steel in an electric arc furnace (EAF) contains a mixture of elements that pose a challenge for both recovery and disposal. This paper relates the leachability of six Canadian EAF dusts in four leaching tests [distilled water, Ontario Regulation 347 Leachate Extraction Procedure, Amount Available for Leaching (AALT), and pH 5 Stat] to their mineralogy. Chromium and nickel contaminants in EAF dust are largely unleachable (<5% available in AALT and pH 5 Stat), as they are found with the predominant spinel ferrite phase in EAF dust. However, even a small proportion of oxidized chromium can result in significant leachate concentrations of highly toxic chromate. The leachability of zinc (7--50% available), lead (2--17% available), and cadmium (9--55% available) can be significant, as large fractions of these contaminants are found as chlorides and oxides. The leaching of these metals is largely controlled by pH. The acid neutralization capacity of the EAF dusts appeared to be controlled by dissolution of lime and zincite, and results from regulatory leaching tests can be misleading because the variable acid neutralization capacity of EAF dusts can lead to very different final leachate pHs (5--12.4). A more informative approach would be to evaluate the total amounts of contaminants available in the long term, and the acid neutralization capacity.

Stegemann, J.A.; Roy, A.; Caldwell, R.J.; Schilling, P.J.; Tittsworth, R.

2000-02-01T23:59:59.000Z

284

Development of materials resistant to metal dusting degradation.  

SciTech Connect (OSTI)

Metal dusting corrosion has been a serious problem in the petroleum and petrochemical industries, such as reforming and syngas production systems. This form of deterioration has led to worldwide material loss for 50 years. For the past three years, we have studied the mechanism of metal dusting for Fe- and Ni-base alloys. In this report, we present a correlation between the weight loss and depth of pits that form in Ni-base alloys. Nickel-base alloys were also tested at 1 and 14.8 atm (210 psi), in a high carbon activity environment. Higher system pressure was found to accelerate corrosion in most Ni-base alloys. To reduce testing time, a pre-pitting method was developed. Mechanical scratches on the alloy surface led to fast metal dusting corrosion. We have also developed preliminary data on the performance of weldments of several Ni-base alloys in a metal dusting environment. Finally, Alloy 800 tubes and plates used in a reformer plant were examined by scanning electron microscopy, energy dispersive X-ray, and Raman spectroscopy. The oxide scale on the surface of the Alloy 800 primarily consists of Fe{sub 1+x}Cr{sub 2-X}O{sub 4} spinel phase with high Fe content. Carbon can diffuse through this oxide scale. It was discovered that the growth of metal dusting pits could be stopped by means of a slightly oxidized alloy surface. This leads to a new way to solve metal dusting problem.

Natesan, K.; Zeng, Z.

2006-04-24T23:59:59.000Z

285

Airborne coal dust reduction in Romanian power plants  

SciTech Connect (OSTI)

Romanian power plant coal handling and preparation areas have not introduced adequate dust collection systems. Therefore, the measurement of airborne coal dust shows that these values are higher than the maximum allowable value under Romanian regulations. The author`s company has been testing a dry dust collection system formed by a ductwork/bagfilter/exhaust fan system. The system was installed at a coal transfer point with a drop height of about 10 meters. The quantity of extracted and cleaned air was about 5,000 m{sup 3}/hr. The airborne dust concentration in the exhausted air was under 4 mg/m{sup 3}. Due to an inadequate skirtboard design that did not prove airtight, there was not enough negative pressure in the containment region. The dust collection system efficiency will be improved with design modifications and tested again. The results have shown that the system can be an efficient solution for local dust collection in power plant coal handling facilities.

Matei, M.; Renel, I. [Energy Research and Modernizing Inst., Bucharest (Romania)

1994-12-31T23:59:59.000Z

286

Sensitivity Study of the Effects of Mineral Dust Particle Nonsphericity and Thin Cirrus Clouds on MODIS Dust Optical Depth Retrievals and Direct Radiative Forcing Calculations  

E-Print Network [OSTI]

A special challenge posed by mineral dust aerosols is associated with their predominantly nonspherical particle shapes. In the present study, the scattering and radiative properties for nonspherical mineral dust aerosols at violet-to-blue (0.412, 0...

Feng, Qian

2011-10-21T23:59:59.000Z

287

EAF dust as an electrolytic zinc resource  

SciTech Connect (OSTI)

Two viable options are presently available to the electrolytic zinc producer to supplement the zinc production capability significantly by using electric arc furnace dust (EAFD) or leady ZnO products derived from EAFD: Integrated processing of the materials using the Modified Zincex Process and commingling the zinc sulfate solution from that process with the neutral solution from the calcine leaching circuit; Installing a completely separate circuit for treating the material using technologies such as the Modified Zincex or Esinex Processes. EAFD and halogen-bearing EAFD derived products are a zinc resource which is virtually untapped by new or existing electrolytic zinc producers and which offers them, with the advent of new technologies able to deal with halides, the opportunity to maintain or increase their zinc production from a relatively cheap, if not ``free``, and already mined zinc source. Such an approach would also provide the EAFD producer an alternative, perhaps lower cost, outlet for their material to the currently rather closely held EAFD processing industry.

Zunkel, A.D. [A.D. Zunkel Consultants Inc., Vancouver, WA (United States)

1995-12-31T23:59:59.000Z

288

Energy conditions, traversable wormholes and dust shells  

E-Print Network [OSTI]

Firstly, we review the pointwise and averaged energy conditions, the quantum inequality and the notion of the ``volume integral quantifier'', which provides a measure of the ``total amount'' of energy condition violating matter. Secondly, we present a specific metric of a spherically symmetric traversable wormhole in the presence of a generic cosmological constant, verifying that the null and the averaged null energy conditions are violated, as was to be expected. Thirdly, a pressureless dust shell is constructed around the interior wormhole spacetime by matching the latter geometry to a unique vacuum exterior solution. In order to further minimize the usage of exotic matter, we then find regions where the surface energy density is positive, thereby satisfying all of the energy conditions at the junction surface. An equation governing the behavior of the radial pressure across the junction surface is also deduced. Lastly, taking advantage of the construction, specific dimensions of the wormhole, namely, the throat radius and the junction interface radius, and estimates of the total traversal time and maximum velocity of an observer journeying through the wormhole, are also found by imposing the traversability conditions.

Francisco S. N. Lobo

2004-10-18T23:59:59.000Z

289

Nearby candidate dust-disk pre-main-sequence solar-mass stars  

E-Print Network [OSTI]

I have isolated a population of numerous F stars that appear to be pre-main-sequence (PMS). The candidate PMS stars have been identified using CM diagram, reddening, flux excess in the UV and near-infrared, and luminosity anomaly. Negative luminosity anomaly and excessive UV flux for many of these stars is suggestive of accretion disks, while the NIR excess is indicative in many cases of the presence of dust disk thermal emission. Observed overluminosity of many PMS candidates is consistent with their pre-main-sequence status. The bulk of the PMS candidates is located within 200 pc, exhibiting strong association with regions of star formation that are numerous between ~130 to 180 pc. The number of PMS candidates plummets redward of the spectral type ~ F5. This effect may provide important clues for understanding the evolution of PMS stars in the solar-mass range.

A. A. Suchkov

2002-10-25T23:59:59.000Z

290

The Absence of Cold Dust and the Mineralogy and Origin of the Warm Dust Encircling BD +20 307  

E-Print Network [OSTI]

Spitzer Space Telescope photometry and spectroscopy of BD +20 307 show that all of the dust around this remarkable Gyr-old spectroscopic binary arises within 1 AU. No additional cold dust is needed to fit the infrared excess. Peaks in the 10 and 20 micron spectrum are well fit with small silicates that should be removed on a timescale of years from the system. This is the dustiest star known for its age, which is >1 Gyr. The dust cannot arise from a steady-state collisional cascade. A catastrophic collision of two rocky, planetary-scale bodies in the terrestrial zone is the most likely source for this warm dust because it does not require a reservoir of planetesimals in the outer system.

Weinberger, A J; Song, I; Zuckerman, B

2010-01-01T23:59:59.000Z

291

THE ABSENCE OF COLD DUST AND THE MINERALOGY AND ORIGIN OF THE WARM DUST ENCIRCLING BD +20 307  

SciTech Connect (OSTI)

Spitzer Space Telescope photometry and spectroscopy of BD +20 307 show that all of the dust around this remarkable Gyr-old spectroscopic binary arises within 1 AU. No additional cold dust is needed to fit the infrared excess. Peaks in the 10 and 20 {mu}m spectrum are well fit with small silicates that should be removed on a timescale of years from the system. This is the dustiest star known for its age, which is {approx}>1 Gyr. The dust cannot arise from a steady-state collisional cascade. A catastrophic collision of two rocky, planetary-scale bodies in the terrestrial zone is the most likely source for this warm dust because it does not require a reservoir of planetesimals in the outer system.

Weinberger, A. J. [Department of Terrestrial Magnetism, Carnegie Institution of Washington 5241 Broad Branch Road NW, Washington, DC 20015 (United States); Becklin, E. E.; Zuckerman, B. [Department of Physics and Astronomy, University of California Los Angeles, Box 951547, Los Angeles, CA 90095-1562 (United States); Song, I., E-mail: weinberger@dtm.ciw.edu, E-mail: becklin@astro.ucla.edu, E-mail: ben@astro.ucla.edu, E-mail: song@uga.edu [Department of Physics and Astronomy, University of Georgia, Athens, GA 30602-2451 (United States)

2011-01-10T23:59:59.000Z

292

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

E-Print Network [OSTI]

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

J. C. Augereau; H. Beust

2006-04-13T23:59:59.000Z

293

Development of materials resistant to metal dusting degradation.  

SciTech Connect (OSTI)

The deposition of carbon from carbonaceous gaseous environments is prevalent in many chemical and petrochemical processes such as, hydrogen-, ammonia-, and methanol-reforming systems, syngas production systems, and iron-ore reduction plants. One of the major consequences of carbon deposition is the degradation of structural materials by a phenomenon known as ''metal dusting''. There are two major issues of importance in metal dusting. First is formation of coke and subsequent deposition of coke on metallic structural components. Second is the initiation and subsequent propagation of metal dusting degradation of the structural alloy. In the past, we reported on the mechanism for metal dusting of Fe- and Ni-base alloys. In this report, we present metal dusting data on both Fe- and Ni-base alloys after exposure in high and atmospheric pressure environments that simulate the gas chemistry in operating hydrogen reformers. We have also measured the progression of pits by measuring the depth as a function of exposure time for a variety of Fe- and Ni-base structural alloys. We have clearly established the role of transport of iron in forming a non-protective spinel phase in the initiation process and presence of carbon transfer channels in the oxide scale for the continued propagation of pits, by nano-beam X-ray analysis using the advance photon source (APS), Raman scattering, and SEM/EDX analysis. In this report, we have developed correlations between weight loss and pit progression rates and evaluated the effects of carbon activity, system pressure, and alloy chemistry, on weight loss and pit propagation. To develop pit propagation data for the alloys without incurring substantial time for the initiation of pits, especially for the Ni-base alloys that exhibit incubation times of thousands of hours, a pre-pitting method has been developed. The pre-pitted alloys exhibited pit propagation rates similar to those of materials tested without pre-pitting. We have also developed a substantial body of metal-dusting data on the performance of Fe- and Ni-base weldments. During the course of this project, we have developed new Ni-base and Cu-base alloys and tested them in simulated metal dusting environments at 1 atm and at high pressures. Results clearly showed superior performance of both classes of alloys in resisting metal dusting. We also developed an approach to mitigate metal dusting by performing an intermediate oxidation step for extending the life of alloys in which metal dusting has initiated and pits are in progression. Finally, we have analyzed several components that have failed in plants such as hydrogen plant, pilot plant reformer, and a gas boiler.

Natesan, K.; Zeng, Z.; Nuclear Engineering Division

2007-12-07T23:59:59.000Z

294

THE SEEDS DIRECT IMAGING SURVEY FOR PLANETS AND SCATTERED DUST EMISSION IN DEBRIS DISK SYSTEMS  

SciTech Connect (OSTI)

Debris disks around young main-sequence stars often have gaps and cavities which for a long time have been interpreted as possibly being caused by planets. In recent years, several giant planet discoveries have been made in systems hosting disks of precisely this nature, further implying that interactions with planets could be a common cause of such disk structures. As part of the SEEDS high-contrast imaging survey, we are surveying a population of debris-disk-hosting stars with gaps and cavities implied by their spectral energy distributions, in order to attempt to spatially resolve the disk as well as to detect any planets that may be responsible for the disk structure. Here, we report on intermediate results from this survey. Five debris disks have been spatially resolved, and a number of faint point sources have been discovered, most of which have been tested for common proper motion, which in each case has excluded physical companionship with the target stars. From the detection limits of the 50 targets that have been observed, we find that {beta} Pic b-like planets ({approx}10 M{sub jup} planets around G-A-type stars) near the gap edges are less frequent than 15%-30%, implying that if giant planets are the dominant cause of these wide (27 AU on average) gaps, they are generally less massive than {beta} Pic b.

Janson, Markus; Brandt, Timothy D. [Department of Astrophysical Sciences, Princeton University, NJ 08544 (United States); Moro-Martin, Amaya [Department of Astrophysics, CAB (INTA-CSIC), Instituto Nacional de Tecnica Aerospacial, Torrejonde Ardoz, E-28850 Madrid (Spain); Usuda, Tomonori; Kudo, Tomoyuki; Egner, Sebastian [Subaru Telescope, 650 North Aohoku Place, Hilo, HI 96720 (United States); Thalmann, Christian [Astronomical Institute ''Anton Pannekoek'', University of Amsterdam, Science Park 904, 1098-XH Amsterdam (Netherlands); Carson, Joseph C. [Department of Physics and Astronomy, College of Charleston, 58 Coming Street, Charleston, SC 29424 (United States); Goto, Miwa [Universitaets-Sternwarte Muenchen, Ludwig-Maximilians-Universitaet, Scheinerstr. 1, D-81679 Munich (Germany); Currie, Thayne [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, M5S 3H4 Toronto, ON (Canada); McElwain, M. W. [Exoplanets and Stellar Astrophysics Laboratory, Code 667, Goddard Space Flight Center, Greenbelt, MD 2071 (United States); Itoh, Yoichi [Nishi-Harima Astronomical Observatory, Center for Astronomy, University of Hyogo, 407-2 Nishigaichi, Sayo, Hyogo 679-5313 (Japan); Fukagawa, Misato [Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 (Japan); Crepp, Justin [Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46556 (United States); Kuzuhara, Masayuki; Hashimoto, Jun; Kusakabe, Nobuhiko [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Abe, Lyu [Laboratoire Lagrange, UMR7239, University of Nice-Sophia Antipolis, CNRS, Observatoire de la Cote d'Azur, F-06300 Nice (France); Brandner, Wolfgang; Feldt, Markus, E-mail: janson@astro.princeton.edu [Max Planck Institute for Astronomy, Koenigstuhl 17, D-69117 Heidelberg (Germany); and others

2013-08-10T23:59:59.000Z

295

AN IMPRINT OF MOLECULAR CLOUD MAGNETIZATION IN THE MORPHOLOGY OF THE DUST POLARIZED EMISSION  

SciTech Connect (OSTI)

We describe a morphological imprint of magnetization found when considering the relative orientation of the magnetic field direction with respect to the density structures in simulated turbulent molecular clouds. This imprint was found using the Histogram of Relative Orientations (HRO), a new technique that utilizes the gradient to characterize the directionality of density and column density structures on multiple scales. We present results of the HRO analysis in three models of molecular clouds in which the initial magnetic field strength is varied, but an identical initial turbulent velocity field is introduced, which subsequently decays. The HRO analysis was applied to the simulated data cubes and mock-observations of the simulations produced by integrating the data cube along particular lines of sight. In the three-dimensional analysis we describe the relative orientation of the magnetic field B with respect to the density structures, showing that: (1) the magnetic field shows a preferential orientation parallel to most of the density structures in the three simulated cubes, (2) the relative orientation changes from parallel to perpendicular in regions with density over a critical density n{sub T} in the highest magnetization case, and (3) the change of relative orientation is largest for the highest magnetization and decreases in lower magnetization cases. This change in the relative orientation is also present in the projected maps. In conjunction with simulations, HROs can be used to establish a link between the observed morphology in polarization maps and the physics included in simulations of molecular clouds.

Soler, J. D.; Netterfield, C. B.; Fissel, L. M. [Department of Astronomy and Astrophysics, University of Toronto, Toronto, ON M5S 3H4 (Canada); Hennebelle, P. [Laboratoire de Radioastronomie, Ecole Normale Superiure and Observatoire de Paris, UMR CNRS 8112. 24 rue Lhomond F-75231 Paris Cedex 05 (France); Martin, P. G.; Miville-Deschenes, M.-A., E-mail: soler@astro.utoronto.ca [Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St. George Street, Toronto, ON M5S 3H8 (Canada)

2013-09-10T23:59:59.000Z

296

Emission of non-thermal microwave radiation by a Martian dust storm Christopher Ruf,1  

E-Print Network [OSTI]

of the lowest three modes of the Martian Schumann Resonance (SR). The SR results from electromagnetic standing

Ruf, Christopher

297

Probing Protoplanetary Disks with Silicate Emission: Where is the silicate emission zone?  

E-Print Network [OSTI]

Recent results indicate that the grain size and crystallinity inferred from observations of silicate features may be correlated with spectral type of the central star and/or disk geometry. In this paper, we show that grain size, as probed by the 10 um silicate feature peak-to-continuum and 11.3-to-9.8 um flux ratios, is inversely proportional to log L_star. These trends can be understood using a simple two-layer disk model for passive irradiated flaring disks, CGPLUS. We find that the radius, R_10, of the 10 um silicate emission zone in the disk goes as (L_star/L_sun)^0.56, with slight variations depending on disk geometry (flaring angle, inner disk radius). The observed correlations, combined with simulated emission spectra of olivine and pyroxene mixtures, imply a grain size dependence on luminosity. Combined with the fact that R_10 is smaller for less luminous stars, this implies that the apparent grain size of the emitting dust is larger for low-luminositysources. In contrast, our models suggest that the crystallinity is only marginally affected, because for increasing luminosity, the zone for thermal annealing (assumed to be at T>800 K) is enlarged by roughly the same factor as the silicate emission zone. The observed crystallinity is affected by disk geometry, however, with increased crystallinity in flat disks. The apparent crystallinity may also increase with grain growth due to a corresponding increase in contrast between crystalline and amorphous silicate emission bands.

J. E. Kessler-Silacci; C. P. Dullemond; J. -C. Augereau; B. Merin; V. C. Geers; E. F. van Dishoeck; N. J. Evans II; G. A. Blake; J. M. Brown

2006-12-15T23:59:59.000Z

298

BP's Perspective on Emissions Purdue Emissions Trading Workshop  

E-Print Network [OSTI]

BP's Perspective on Emissions Trading Purdue Emissions Trading Workshop April 30, 2010 Mark - Government policies can create a carbon price via three primary mechanisms: - Emissions trading (BP's strong

299

EXCITATION OF THE AROMATIC INFRARED EMISSION BANDS: CHEMICAL ENERGY IN HYDROGENATED AMORPHOUS CARBON PARTICLES?  

SciTech Connect (OSTI)

We outline a model for the heating of hydrogenated amorphous carbon (HAC) dust via the release of stored chemical energy and show that this energy ({approx}12 kJ mole{sup -1}) is sufficient to heat dust grains of classical size (50-1000 A) to temperatures at which they can emit at 3.3 {mu}m and other 'UIR' wavelengths. Using laboratory data, we show that this heating process is consistent with a concentration of a few percent of dangling bonds in HAC and may be initiated by the recombination of trapped H atoms. We suggest that the release of chemical energy from dust represents an additional source of excitation for the UIR bands relaxing the previous requirement that only stochastically heated molecules having fewer than {approx}50 atoms can produce emission at 3.3 {mu}m.

Duley, W. W. [Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Williams, D. A., E-mail: wwduley@uwaterloo.ca [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom)

2011-08-20T23:59:59.000Z

300

Dust properties inside molecular clouds from coreshine modeling and observations  

E-Print Network [OSTI]

Context. Using observations to deduce dust properties, grain size distribution, and physical conditions in molecular clouds is a highly degenerate problem. Aims. The coreshine phenomenon, a scattering process at 3.6 and 4.5 $\\mu$m that dominates absorption, has revealed its ability to explore the densest parts of clouds. We want to use this effect to constrain the dust parameters. The goal is to investigate to what extent grain growth (at constant dust mass) inside molecular clouds is able to explain the coreshine observations. We aim to find dust models that can explain a sample of Spitzer coreshine data. We also look at the consistency with near-infrared data we obtained for a few clouds. Methods. We selected four regions with a very high occurrence of coreshine cases: Taurus-Perseus, Cepheus, Chameleon and L183/L134. We built a grid of dust models and investigated the key parameters to reproduce the general trend of surface bright- nesses and intensity ratios of both coreshine and near-infrared observation...

Lefèvre, Charlène; Juvela, Mika; Paladini, Roberta; Lallement, Rosine; Marshall, D J; Andersen, Morten; Bacmann, Aurore; Mcgee, Peregrine M; Montier, Ludovic; Noriega-Crespo, Alberto; Pelkonen, V -M; Ristorcelli, Isabelle; Steinacker, Jürgen

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fugitive dust emissions" 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

Excess Emissions (New Mexico)  

Broader source: Energy.gov [DOE]

This regulation establishes requirements for a source whose operation results in an excess emission and to establish criteria for a source whose operation results in an excess emission to claim an...

302

Emissions Trading and Social Justice  

E-Print Network [OSTI]

David  M.  Driesen,  Does  Emissions  Trading  Encourage  Jason  Coburn,  Emissions  Trading   and   Environmental  Szambelan,  U.S.  Emissions  Trading  Markets  for  SO 2  

Farber, Daniel A

2011-01-01T23:59:59.000Z

303

Migration of Artificially Introduced Micron Size Carbon Dust in the DIII-D Divertor  

SciTech Connect (OSTI)

Migration of pre-characterized carbon dust in a tokamak environment was studied by introducing about 30 milligrams of dust flakes 5-10 {micro}m in diameter in the lower divertor of DIII-D using the DiMES sample holder. The dust was exposed to high power ELMing Hmode discharges in lower-single-null magnetic configuration with the strike points swept across the divertor floor. When the outer strike point (OSP) passed over the dust holder exposing it to high particle and heat fluxes, part of the dust was injected into the plasma. In about 0.1 sec following the OSP pass over the dust, 1-2% of the total dust carbon content (2-4 x 10{sup 19} carbon atoms, equivalent to a few million dust particles) penetrated the core plasma, raising the core carbon density by a factor of 2-3. When the OSP was inboard of the dust holder, the dust injection continued at a lower rate. Individual dust particles were observed moving at velocities of 10-100 m/s, predominantly in the toroidal direction for deuteron flow to the outer divertor target, consistent with the ion drag force. The observed behavior of the dust is in qualitative agreement with modeling by the 3D DustT code.

Rudakov, D; West, W; Wong, C; Brooks, N; Evans, T; Fenstermacher, M; Groth, M; Krasheninnikov, S; Lasnier, C; McLean, A; Pigarov, A Y; Solomon, W; Antar, G; Boedo, J; Doerner, R; Hollmann, E; Hyatt, A; Maingi, R; Moyer, R; Nagy, A; Nishino, N; Roquemore, L; Stangeby, P; Watkins, J

2006-05-15T23:59:59.000Z

304

Lithium Wall Conditioning And Surface Dust Detection On NSTX  

SciTech Connect (OSTI)

Lithium evaporation onto NSTX plasma facing components (PFC) has resulted in improved energy confinement, and reductions in the number and amplitude of edge-localized modes (ELMs) up to the point of complete ELM suppression. The associated PFC surface chemistry has been investigated with a novel plasma material interface probe connected to an in-vacuo surface analysis station. Analysis has demonstrated that binding of D atoms to the polycrystalline graphite material of the PFCs is fundamentally changed by lithium - in particular deuterium atoms become weakly bonded near lithium atoms themselves bound to either oxygen or the carbon from the underlying material. Surface dust inside NSTX has been detected in real-time using a highly sensitive electrostatic dust detector. In a separate experiment, electrostatic removal of dust via three concentric spiral-shaped electrodes covered by a dielectric and driven by a high voltage 3-phase waveform was evaluated for potential application to fusion reactors

Skinner, C H; Bell, M G; Friesen, F.Q.L.; Heim, B; Jaworski, M A; Kugel, H; Maingi, R; Rais, B

2011-05-23T23:59:59.000Z

305

VARIABLE WINDS AND DUST FORMATION IN R CORONAE BOREALIS STARS  

SciTech Connect (OSTI)

We have observed P-Cygni and asymmetric, blue-shifted absorption profiles in the He I {lambda}10830 lines of 12 R Coronae Borealis stars over short (1 month) and long (3 yr) timescales to look for variations linked to their dust-formation episodes. In almost all cases, the strengths and terminal velocities of the line vary significantly and are correlated with dust formation events. Strong absorption features with blue-shifted velocities {approx}400 km s{sup -1} appear during declines in visible brightness and persist for about 100 days after recovery to maximum brightness. Small residual winds of somewhat lower velocity are present outside of the decline and recovery periods. The correlations support models in which recently formed dust near the star is propelled outward at high speed by radiation pressure and drags the gas along with it.

Clayton, Geoffrey C.; Zhang Wanshu [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); Geballe, T. R., E-mail: gclayton@fenway.phys.lsu.edu, E-mail: wzhan21@lsu.edu, E-mail: tgeballe@gemini.edu [Gemini Observatory, 670 N. A'ohoku Place, Hilo, HI 96720 (United States)

2013-08-01T23:59:59.000Z

306

Constraining the structure of the transition disk HD 135344B (SAO 206462) by simultaneous modeling of multi-wavelength gas and dust observations  

E-Print Network [OSTI]

HD 135344B is an accreting (pre-) transition disk which displays emission of warm CO extending tens of AU inside its 30 AU dust cavity. We employ the dust radiative transfer code MCFOST and the thermo-chemical code ProDiMo to derive the disk structure from the simultaneous modeling of the spectral energy distribution (SED), VLT/CRIRES CO P(10) 4.75 micron, Herschel/PACS [O I] 63 micron, Spitzer-IRS, and JCMT 12CO J=3-2 spectra, VLTI/PIONIER H-band visibilities, and constraints from (sub-)mm continuum interferometry and near-IR imaging. We found a disk model able to describe simultaneously the current observations. This disk has the following structure: (1) to reproduce the SED, the near-IR interferometry data, and the CO ro-vibrational emission, refractory grains (we suggest carbon) are present inside the silicate sublimation radius (0.08 100 to account for the 870 micron continuum upper limit and the CO P(10) line flux; (5) the gas/dust ratio at 30

Carmona, A; Thi, W F; Benisty, M; Ménard, F; Grady, C; Kamp, I; Woitke, P; Olofsson, J; Roberge, A; Brittain, S; Dûchene, G; Meeus, G; Martin-Zaïdi, C; Dent, B; Bouquin, J B Le; Berger, J P

2014-01-01T23:59:59.000Z

307

Regulation of GHG emissions from transportation fuels: Emission quota versus emission intensity standard  

E-Print Network [OSTI]

Derivation of average cost of emission reduction by blending?) and ? respectively. GHG emissions per unit of blend is, ?+ ?? i Reduction in GHG emissions with respect to unblended

Rajagopal, Deepak

2010-01-01T23:59:59.000Z

308

Chemistry and line emission of outer protoplanetary disks  

E-Print Network [OSTI]

The structure and chemistry of protoplanetary disks depends strongly on the nature of the central star around which it has formed. The dust temperature is mainly set by the stellar luminosity, while the chemistry of the upper disk layers depends on the amount of intercepted UV and X-ray flux. We will study the differences in chemistry, thermal sturcture and line emission around Herbig Ae/Be, T Tauri stars and low mass M dwarfs. Predictions will be made for future observations with SOFIA and Herschel.

Inga Kamp; Cornelis P. Dullemond; Michiel Hogerheijde; Jesus Emilio Enriquez

2005-09-21T23:59:59.000Z

309

Dust in the wind: the role of recent mass loss in long gamma-ray bursts  

E-Print Network [OSTI]

We study the late-time (t>0.5 days) X-ray afterglows of nearby (z3) X-ray emission that is inconsistent with forward shock synchrotron radiation associated with the afterglow. These explosions also show larger-than-average intrinsic absorption (NH_x,i >6d21 cm-2) and prompt gamma-ray emission with extremely long duration (T_90>1000 s). Chance association of these three rare properties (i.e. large NH_x,i, super-soft Gamma_x and extreme duration) in the same class of explosions is statistically unlikely. We associate these properties with the turbulent mass-loss history of the progenitor star that enriched and shaped the circum-burst medium. We identify a natural connection between NH_x,i Gamma_x and T_90 in these sources by suggesting that the late-time super-soft X-rays originate from radiation reprocessed by material lost to the environment by the stellar progenitor before exploding, (either in the form of a dust echo or as reprocessed radiation from a long-lived GRB remnant), and that the interaction of the...

Margutti, Raffaella; Guidorzi, C; Lazzati, D; Milisavljevic, D; Kamble, A; Laskar, T; Parrent, J; Gehrels, N C

2014-01-01T23:59:59.000Z

310

Engineering and economic impacts of prohibiting recombination recirculation dust at export elevators  

E-Print Network [OSTI]

The objectives of this research were to develop engineering descriptions of dust control systems currently being used in grain export facilities, to determine the retrofit requirements of the dust control and handling systems to comply...

Whitelock, Derek Paul

1994-01-01T23:59:59.000Z

311

Airborne dust in Saudi Arabia : source areas, entrainment, simulation and composition.  

E-Print Network [OSTI]

??Spatial and temporal characteristics of dust storm activity in Saudi Arabia has been established using coarse-particle (PM10) dust concentrations recorded by the KACST monitoring network… (more)

Alharbi, Badr Hadhidh A

2009-01-01T23:59:59.000Z

312

Integrated impact analysis of yellow-dust storms : a regional case study in China  

E-Print Network [OSTI]

The dust storm is a meteorological event that is caused by strong winds and proceeds from arid and semi-arid regions, transporting a thick cloud of fine sediments. In China, the sediments of dust storms mainly come from ...

Ai, Ning, 1978-

2003-01-01T23:59:59.000Z

313

Effect of argon addition on plasma parameters and dust charging in hydrogen plasma  

SciTech Connect (OSTI)

Experimental results on effect of adding argon gas to hydrogen plasma in a multi-cusp dusty plasma device are reported. Addition of argon modifies plasma density, electron temperature, degree of hydrogen dissociation, dust current as well as dust charge. From the dust charging profile, it is observed that the dust current and dust charge decrease significantly up to 40% addition of argon flow rate in hydrogen plasma. But beyond 40% of argon flow rate, the changes in dust current and dust charge are insignificant. Results show that the addition of argon to hydrogen plasma in a dusty plasma device can be used as a tool to control the dust charging in a low pressure dusty plasma.

Kakati, B., E-mail: bharatkakati15@gmail.com; Kausik, S. S.; Saikia, B. K. [Centre of Plasma Physics-Institute for Plasma Research, Nazirakhat, Sonapur, Kamrup 782402, Assam (India); Bandyopadhyay, M.; Saxena, Y. C. [Institute for Plasma Research, Bhat, Gandhinagar 382 428 (India)

2014-10-28T23:59:59.000Z

314

E-Print Network 3.0 - agricultural dust exposure Sample Search...  

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

such as dust mites or cockroach-related allergens (Finn et al. 2000; Platts... (e.g., a house-dust or passive air sample) might be an appropriate measure of exposure for use......

315

DISCOVERY OF 'WARM DUST' GALAXIES IN CLUSTERS AT z {approx} 0.3: EVIDENCE FOR STRIPPING OF COOL DUST IN THE DENSE ENVIRONMENT?  

SciTech Connect (OSTI)

Using far-infrared imaging from the 'Herschel Lensing Survey', we derive dust properties of spectroscopically confirmed cluster member galaxies within two massive systems at z {approx} 0.3: the merging Bullet Cluster and the more relaxed MS2137.3-2353. Most star-forming cluster sources ({approx}90%) have characteristic dust temperatures similar to local field galaxies of comparable infrared (IR) luminosity (T{sub dust} {approx} 30 K). Several sub-luminous infrared galaxy (LIRG; L{sub IR} < 10{sup 11} L{sub Sun }) Bullet Cluster members are much warmer (T{sub dust} > 37 K) with far-infrared spectral energy distribution (SED) shapes resembling LIRG-type local templates. X-ray and mid-infrared data suggest that obscured active galactic nuclei do not contribute significantly to the infrared flux of these 'warm dust' galaxies. Sources of comparable IR luminosity and dust temperature are not observed in the relaxed cluster MS2137, although the significance is too low to speculate on an origin involving recent cluster merging. 'Warm dust' galaxies are, however, statistically rarer in field samples (>3{sigma}), indicating that the responsible mechanism may relate to the dense environment. The spatial distribution of these sources is similar to the whole far-infrared bright population, i.e., preferentially located in the cluster periphery, although the galaxy hosts tend toward lower stellar masses (M{sub *} < 10{sup 10} M{sub Sun }). We propose dust stripping and heating processes which could be responsible for the unusually warm characteristic dust temperatures. A normal star-forming galaxy would need 30%-50% of its dust removed (preferentially stripped from the outer reaches, where dust is typically cooler) to recover an SED similar to a 'warm dust' galaxy. These progenitors would not require a higher IR luminosity or dust mass than the currently observed normal star-forming population.

Rawle, T. D.; Rex, M.; Egami, E.; Walth, G.; Pereira, M. J. [Steward Observatory, University of Arizona, 933 N. Cherry Avenue, Tucson, AZ 85721 (United States); Chung, S. M.; Gonzalez, A. H. [Department of Astronomy, University of Florida, Gainesville, FL 32611-2055 (United States); Perez-Gonzalez, P. G. [Departamento de Astrofisica, Facultad de CC. Fisicas,Universidad Complutense de Madrid, E-28040 Madrid (Spain); Smail, I. [Institute for Computational Cosmology, Durham University, South Road, Durham DH1 3LE (United Kingdom); Altieri, B.; Valtchanov, I. [Herschel Science Centre, ESAC, ESA, P.O. Box 78, Villanueva de la Canada, E-28691 Madrid (Spain); Appleton, P.; Fadda, D. [IPAC, California Institute of Technology, Pasadena, CA 91125 (United States); Alba, A. Berciano [ASTRON, Oude Hoogeveensedijk 4, NL-7991 PD Dwingeloo (Netherlands); Blain, A. W. [Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Dessauges-Zavadsky, M. [Observatoire de Geneve, Universite de Geneve, 51 Ch. des Maillettes, CH-1290 Sauverny (Switzerland); Van der Werf, P. P. [Sterrewacht Leiden, Leiden University, P.O. Box 9513, NL-2300 RA Leiden (Netherlands); Zemcov, M., E-mail: trawle@as.arizona.edu [Department of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States)

2012-09-10T23:59:59.000Z

316

An investigation of dust storm generation in the Southern Great Plains  

E-Print Network [OSTI]

An investigation of dust sto'rms in the Southern Great Plains was conducted to determine correlations between dust and precipitation, Antecedent Precipitation Index (API), wind, time of occurrence, and dew-point depression. Re- lationships between blowing dust... Summary of favorable parameters and conditions for springtime generation of blowing dust in local areas of the Southern Great Plains 66 LIST OF FIGURES Figure Title Page Physiographic regions of the United States and their dominant landf orms (after...

Pollard, Marshall Conrad

1977-01-01T23:59:59.000Z

317

Existence domains of large amplitude dust-acoustic solitons in non-thermal plasmas with positive and negative dust  

SciTech Connect (OSTI)

Using the traditional Sagdeev pseudopotential approach, the existence of large amplitude solitons is investigated for a plasma composed of cold negative dust, adiabatic positive dust, non-thermal ions and Boltzmann electrons. The lower and upper soliton Mach number limitations are determined as a function of various parameters and physical reasons are provided as to why these Mach number limits occur. Some regions in parameter space have been identified where only negative or positive solitons occur, whereas, other regions support the coexistence of both positive and negative potential solitons.

Maharaj, S. K. [South African National Space Agency Space Science, P O Box 32, Hermanus 7200 (South Africa); Bharuthram, R. [University of the Western Cape, Modderdam Road, Bellville 7530 (South Africa); Singh, S. V.; Lakhina, G. S. [Indian Institute of Geomagnetism, New Panvel, Navi Mumbai 410218 (India); Pillay, S. R. [University of KwaZulu-Natal, Private Bag X54001, Durban 4000 (South Africa)

2011-11-29T23:59:59.000Z

318

Large amplitude dust-acoustic double layers in non-thermal plasmas with positive and negative dust  

SciTech Connect (OSTI)

The existence of large amplitude double layers in a plasma composed of cold negative dust, adiabatic positive dust, non-thermal ions and Boltzmann electrons is investigated using the Sagdeev pseudopotential technique. Both positive potential and negative potential double layers are found to be supported by the model. The variation of the maximum amplitudes of the double layers and corresponding Mach numbers are examined as a function of various plasma parameters. In particular, we investigate to what extent ion non-thermal effects are required for positive potential double layers to occur.

Maharaj, S. K. [South African National Space Agency Space Science, P O Box 32, Hermanus 7200 (South Africa); Bharuthram, R. [University of the Western Cape, Modderdam Road, Bellville 7530 (South Africa); Singh, S. V.; Lakhina, G. S. [Indian Institute of Geomagnetism, New Panvel, Navi Mumbai 410218 (India); Pillay, S. R. [University of KwaZulu-Natal, Private Bag X54001, Durban 4000 (South Africa)

2011-11-29T23:59:59.000Z

319

EA-1055; Environmental Assessment and (FONSI) for The Proposed...  

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

water sprays per State regulations on fugitive emissions from construction (WAC 173-400 - Air Pollution Sources). Washington State University construction practice is to monitor...

320

DATE  

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

200K SECTION C. Environmental Aspects Potential Sources of Impact 1. Air Pollutants - Fugitive emissions will be generated from breaking up the concrete pads around the...

Note: This page contains sample records for the topic "fugitive dust emissions" 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

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

E-Print Network [OSTI]

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

Rycroft, Chris H.

322

Atmospheric Environment 40 (2006) 38813897 Field measurements of desert dust deposition in Libya  

E-Print Network [OSTI]

Atmospheric Environment 40 (2006) 3881­3897 Field measurements of desert dust deposition in Libya-based dust monitoring study of three zones across Libya, ranging from the Mediterranean coast to the Sahara studies in North Africa shows that areas of Libya have the highest dust deposition rates on record. r 2006

Clarke, Michèle

323

The global distribution of mineral dust and its impacts on the climate system: A review  

E-Print Network [OSTI]

radiation budget and hydrological cycle through their radiative and cloud condensation nucleus effects of an intercontinental scale, including North African dust plumes over the Atlantic Ocean, summer dust plumes from the Arabian Peninsula over the Arabian Sea and Indian Ocean and spring dust plumes from East Asia over

Hickman, Mark

324

TITLE: Preliminary Examination of Impact Craters on Al Foil from the Stardust Interstellar Dust Collector  

E-Print Network [OSTI]

the Stardust Interstellar Dust Collector SESSION TYPE: Poster; SESSION TITLE: P43A. Extraterrestrial Dust@home dusters ABSTRACT BODY: The Interstellar Dust Collector from the NASA Stardust mission provides) stream in order to obtain such information as grain composition and microstructure. The collector

325

Dust-rainfall feedbacks in the West African Sahel Wanching Jacquie Hui,1,2  

E-Print Network [OSTI]

Dust-rainfall feedbacks in the West African Sahel Wanching Jacquie Hui,1,2 Benjamin I. Cook,3 in this region. Citation: Hui, W. J., B. I. Cook, S. Ravi, J. D. Fuentes, and P. D'Odorico (2008), Dust of solar radiation [Lohmann and Feichter, 2005]. [3] Dust aerosols can contribute to surface cooling

326

Dust in the Earth system: The biogeochemical linking of land, air, and  

E-Print Network [OSTI]

1 Dust in the Earth system: The biogeochemical linking of land, air, and sea Andy Ridgwell1 of CO2 from the atmosphere. The complex way in which dust biogeochemically links land, air, and sea of atmospheric aerosols. In this review, however, we consider dust to be soil mineral fragments. The entrainment

Kohfeld, Karen

327

STANDARDS CONTROLLING AIR EMISSIONS FOR THE SOIL DESICCATION PILOT TEST  

SciTech Connect (OSTI)

This air emissions document supports implementation of the Treatability Test Plan for Soil Desiccation as outlined in the Deep Vadose Zone Treatability Test Plan for the Hanford Central Plateau (DOE/RL-2007-56). Treatability testing supports evaluation of remedial technologies for technetium-99 (Tc-99) contamination in the vadose zone at sites such as the BC Cribs and Trenches. Soil desiccation has been selected as the first technology for testing because it has been recommended as a promising technology in previous Hanford Site technology evaluations and because testing of soil desiccation will provide useful information to enhance evaluation of other technologies, in particular gas-phase remediation technologies. A soil desiccation pilot test (SDPT) will evaluate the desiccation process (e.g., how the targeted interval is dried) and the long-term performance for mitigation of contaminant transport. The SDPT will dry out a moist zone contaminated by Tc-99 and nitrate that has been detected at Well 299-E13-62 (Borehole C5923). This air emissions document applies to the activities to be completed to conduct the SDPT in the 200-BC-1 operable unit located in the 200 East Area of the Hanford Site. Well 299-E13-62 is planned to be used as an injection well. This well is located between and approximately equidistant from cribs 216-B-16, 216-B-17, 216-B-18. and 216-B-19. Nitrogen gas will be pumped at approximately 300 ft{sup 3}/min into the 299-EI3-62 injection well, located approximately 12 m (39 ft) away from extraction well 299-EI3-65. The soil gas extraction rate will be approximately 150 ft{sup 3}/min. The SDPT will be conducted continuously over a period of approximately six months. The purpose of the test is to evaluate soil desiccation as a potential remedy for protecting groundwater. A conceptual depiction is provided in Figure 1. The soil desiccation process will physically dry, or evaporate, some of the water from the moist zone of interest. As such, it is expected that Tc-99 and nitrate will remain with the water residual that is not removed, or remain as a salt bound to the soil particles. In addition, the SDPT will be conducted at lower extraction velocities to preclude pore water entrainment and thus, the extracted air effluent should be free of the contaminant residual present in the targeted moist zone. However, to conservatively bound the planned activity for potential radionuclide air emissions, it is assumed, hypothetically, that the Tc-99 does not remain in the zone of interest, but that it instead travels with the evaporated moisture to the extraction well and to the test equipment at the land surface. Thus, a release potential would exist from the planned point source (powered exhaust) for Tc-99 in the extracted moist air. In this hypothetical bounding case there would also be a potential for very minor fugitive emissions to occur due to nitrogen injection into the soil. The maximum value for Tc-99, measured in the contaminated moist zone, is used in calculating the release potential described in Section 2.3. The desiccation mechanism will be evaporation. Nitrate is neither a criteria pollutant nor a toxic air pollutant. It would remain nitrate as a salt adhered to sand and silt grains or as nitrate dissolved in the pore water. Nitrogen, an inert gas, will be injected into the ground during the test. Tracer gasses will also be injected near the beginning, middle, and the end of the test. The tracer gasses are sulfur hexafluoride, trichlorofluoromethane, and difluoromethane.

BENECKE MW

2010-09-08T23:59:59.000Z

328

A Sub-Millimeter Search of Nearby Young Stars for Cold Dust: Discovery of Debris Disks around Two Low-Mass Stars  

E-Print Network [OSTI]

(Abridged) We present results from a JCMT/SCUBA 850 um search for cold dust around nearby young stars belonging to the beta Pic (t~12 Myr) and the Local Association (t~50 Myr) moving groups. Unlike most past sub-mm studies, our sample was chosen on the basis of stellar age. Our observations achieve about an order of magnitude greater sensitivity in dust mass compared to previous work in this age range. We detected two of the three M dwarfs in our sample at 850 um, GJ 182 and GJ 803. GJ 182 may also possess a 25 um excess, indicative of warm dust in the inner few AU of its disk. For GJ 803 (AU Mic), sub-mm mapping finds that the 850 um emission is unresolved. A non-detection of the CO 3-2 line indicates the system is gas-poor, and the SED suggests the presence of a large inner disk hole (~17 AU = 1.7 arcsec in radius). These are possible indications that planets at large separations can form around M dwarfs within \\~10 Myr. In a companion paper (Kalas, Liu & Matthews 2004), we confirm the existence of a dust disk around GJ 803 using optical coronagraphic imaging. Given its youthfulness, proximity, and detectability, the GJ 803 disk will be a valuable system for studying disk, and perhaps planet, formation in great detail. Overall, sub-mm measurements of debris disks point to a drop in dust mass by a factor of about 10^3 within the first ~10 Myr, with the subsequent decline in the masses of sub-mm detected disks consistent with t^{-0.5} to t^{-1}.

Michael C. Liu; Brenda C. Matthews; Jonathan P. Williams; Paul G. Kalas

2004-04-07T23:59:59.000Z

329

The Influence of Dust on the Absorptivity of Radiant Barriers  

E-Print Network [OSTI]

The purpose of this project was to model and quantify the increase of the absorptivity of radiant barriers caused by the accumulation of dust on the surface of radiant barriers. This research was the continuation of a previous work by the author...

Noboa, Homero L.

330

Morphological Investigations of Fibrogenic Action of Estonian Oil Shale Dust  

E-Print Network [OSTI]

A review of morphological investigations carried out to clarify the pathogenicity of industrial dust produced in the mining and processing of Estonian oil shale is given. Histological examination of lungs of workers in the oil shale industry taken at necropsies showed that the inhalation of oil

V. A. Kung

331

The dust and gas content of the Crab Nebula  

E-Print Network [OSTI]

We have constructed MOCASSIN photoionization plus dust radiative transfer models for the Crab Nebula core-collapse supernova (CCSN) remnant, using either smooth or clumped mass distributions, in order to determine the chemical composition and masses of the nebular gas and dust. We computed models for several different geometries suggested for the nebular matter distribution but found that the observed gas and dust spectra are relatively insensitive to these geometries, being determined mainly by the spectrum of the pulsar wind nebula which ionizes and heats the nebula. Smooth distribution models are ruled out since they require 16-49 Msun of gas to fit the integrated optical nebular line fluxes, whereas our clumped models require 7.0 Msun of gas. neither of which can be matched by current CCSN yield predictions. A global gas-phase C/O ratio of 1.65 by number is derived, along with a He/H number ratio of 1.85, A carbonaceous dust composition is favoured by the observed gas-phase C/O ratio: amorphous carbon clu...

Owen, P J

2015-01-01T23:59:59.000Z

332

Global observations of desert dust and biomass burning aerosols  

E-Print Network [OSTI]

Global observations of desert dust and biomass burning aerosols Martin de Graaf KNMI #12; Outline · Absorbing Aerosol Index - Theory · Absorbing Aerosol Index - Reality · Biomass burning.6 Biomass burning over Angola, 09 Sep. 2004 Absorbing Aerosol Index PMD image #12;biomass burning ocean

Graaf, Martin de

333

The AIR, the WATER, the SUN, the DUST,  

E-Print Network [OSTI]

to chemicals on the job or elsewhere in the environment. Researchers at The National Institute of Environmental#12;The AIR, the WATER, the SUN, the DUST, PLANTS and ANIMALS, and the CHEMICALS and METALS of our also make some people sick.Here are some diseases that are related to your Allergies and Asthma (AZ

Bandettini, Peter A.

334

Destruction of Interstellar Dust in Evolving Supernova Remnant Shock Waves  

E-Print Network [OSTI]

Supernova generated shock waves are responsible for most of the destruction of dust grains in the interstellar medium (ISM). Calculations of the dust destruction timescale have so far been carried out using plane parallel steady shocks, however that approximation breaks down when the destruction timescale becomes longer than that for the evolution of the supernova remnant (SNR) shock. In this paper we present new calculations of grain destruction in evolving, radiative SNRs. To facilitate comparison with the previous study by Jones et al. (1996), we adopt the same dust properties as in that paper. We find that the efficiencies of grain destruction are most divergent from those for a steady shock when the thermal history of a shocked gas parcel in the SNR differs significantly from that behind a steady shock. This occurs in shocks with velocities >~ 200 km/s for which the remnant is just beginning to go radiative. Assuming SNRs evolve in a warm phase dominated ISM, we find dust destruction timescales are incre...

Slavin, Jonathan D; Jones, Anthony P

2015-01-01T23:59:59.000Z

335

Imaging of high-speed dust particle trajectories on NSTX  

SciTech Connect (OSTI)

Imaging of high-speed incandescent dust particle trajectories in a tokamak plasma has been accomplished on NSTX using up to three high-speed cameras each viewing the same plasma volume from different locations and operating at speeds up to 68 000 frames/s with exposure times varying from 2 to 300 {mu}s. The dynamics of the dust trajectories can be quite complex exhibiting a large variation in both speed (10-200 m/s) and direction. Simulations of these trajectories will be utilized to ascertain the role dust may play in future machines such as ITER where significant dust production from wall erosion is expected. NSTX has numerous view ports including both tangential as well as radial views in both the midplane and lower divertors. Several vertical ports are also available so that a few specific regions in NSTX may be viewed simultaneously from several different camera positions. The cameras can be operated in the full visible spectrum but near-infrared filters can be utilized to enhance the observation of incandescent particles against a bright background. A description of the cameras and required optics is presented.

Roquemore, A. L.; Davis, W.; Kaita, R.; Skinner, C. H.; Maqueda, R.; Nishino, N. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Nova Photonics, Inc., Princeton, New Jersey 08540 (United States); Hiroshima University, Hiroshima 739-8527 (Japan)

2006-10-15T23:59:59.000Z

336

WEATHER MODIFICATION BY CARBON DUST ABSORPTION OF SOLAR ENERGY  

E-Print Network [OSTI]

WEATHER MODIFICATION BY CARBON DUST ABSORPTION OF SOLAR ENERGY by WM. M. GRAY, WM. M. FRANK, M OF SOLAR ENERGY by w. M. Gray, W. M. Frank, M. L. Corrin and C. A. Stokes Department of Atmospheric Science interception of solar energy. Growing population pressures and predicted future global food shortages dictate

Gray, William

337

absorption features dust: Topics by E-print Network  

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

absorption features dust First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Silicon carbide absorption...

338

NEW CONSTRAINTS ON COMPANIONS AND DUST WITHIN A FEW AU OF VEGA  

SciTech Connect (OSTI)

We report on high contrast near-infrared ({approx}2.2 {mu}m) observations of Vega obtained with the Palomar Fiber Nuller, a dual sub-aperture rotating coronagraph installed at the Palomar Hale telescope. The data show consistent astrophysical null depth measurements at the {approx_equal} 10{sup -3} level or below for three different baseline orientations spanning 60 deg in azimuth, with individual 1{sigma} uncertainties {<=}7 x 10{sup -4}. These high cancellation and accuracy levels translate into a dynamic range greater than 1000:1 inside the diffraction limit of the 5 m telescope beam. Such high contrast performance is unprecedented in the near-infrared and provides improved constraints on Vega's immediate ({approx_equal}20 to 250 mas, or {approx_equal}0.15 to 2 AU) environment. In particular, our measurements rule out any potential companion in the [0.25-1 AU] region contributing more than 1% of the overall near-infrared stellar flux, with limits as low as 0.2% near 0.6 AU. These are the best upper limits established so far by direct detection for a companion to Vega in this inner region. We also conclude that any dust population contributing a significant ({>=}1%) near-infrared thermal excess can arise only within 0.2 AU of the star, and that it must consist of much smaller grains than in the solar zodiacal cloud. Dust emission from farther than {approx_equal}2 AU is also not ruled out by our observations, but would have to originate in strong scattering, pointing again to very small grains.

Mennesson, B.; Serabyn, E.; Martin, S. R.; Liewer, K.; Mawet, D. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109-8099 (United States); Hanot, C., E-mail: bertrand.mennesson@jpl.nasa.gov [AEOS, University of Liege, Allee du 6 Aout, 17 Bat B5c, 4000 Liege (Belgium)

2011-07-20T23:59:59.000Z

339

Asymmetric silicate dust distribution toward the silicate carbon star BM Gem  

E-Print Network [OSTI]

Silicate carbon stars show the 10 micron silicate emission, despite their carbon-rich photospheres. They are considered to have circumbinary or circum-companion disks, which serve as a reservoir of oxygen-rich material shed by mass loss in the past. We present N-band spectro-interferometric observations of the silicate carbon star BM Gem using MIDI at the Very Large Telescope Interferometer (VLTI). Our aim is to probe the spatial distribution of oxygen-rich dust with high spatial resolution. BM Gem was observed with VLTI/MIDI at 44--62 m baselines using the UT2-UT3 and UT3-UT4 baseline configurations. The N-band visibilities observed for BM Gem show a steep decrease from 8 to ~10 micron and a gradual increase longward of ~10 micron, reflecting the optically thin silicate emission feature emanating from sub-micron-sized amorphous silicate grains. The differential phases obtained at baselines of ~44--46 m show significant non-zero values (~ -70 degrees) in the central part of the silicate emission feature between ~9 and 11 micron, revealing a photocenter shift and the asymmetric nature of the silicate emitting region. The observed N-band visibilities and differential phases can be fairly explained by a simple geometrical model in which the unresolved star is surrounded by a ring with azimuthal brightness modulation. The best-fit model is characterized by a broad ring (~70 mas across at 10 micron) with a bright region which is offset from the unresolved star by ~20 mas at a position angle of ~280 degrees. This model can be interpreted as a system with a circum-companion disk and is consistent with the spectroscopic signatures of an accretion disk around an unseen companion recently discovered in the violet spectrum of BM Gem.

Keiichi Ohnaka; Hideyuki Izumiura; Christoph Leinert; Thomas Driebe; Gerd Weigelt; Markus Wittkowski

2008-07-21T23:59:59.000Z

340

Resolved debris disk emission around eta Tel: a young Solar System or ongoing planet formation?  

E-Print Network [OSTI]

60% of the A star members of the 12 Myr old beta Pictoris moving group (BPMG) show significant excess emission in the mid-infrared, several million years after the proto-planetary disk is thought to disperse. Theoretical models suggest this peak may coincide with the formation of Pluto-sized planetesimals in the disk, stirring smaller bodies into collisional destruction. Here we present resolved mid-infrared imaging of the disk of eta Tel (A0V in the BPMG) and consider its implications for the state of planet formation in this system. eta Tel was observed at 11.7 and 18.3um using T-ReCS on Gemini South. The resulting images were compared to simple disk models to constrain the radial distribution of the emitting material. The emission observed at 18.3um is shown to be significantly extended beyond the PSF along a position angle 8 degrees. This is the first time dust emission has been resolved around eta Tel. Modelling indicates that the extension arises from an edge-on disk of radius 0.5 arcsec (~24 AU). Combining the spatial constraints from the imaging with those from the spectral energy distribution shows that >50% of the 18um emission comes from an unresolved dust component at ~4 AU. The radial structure of the eta Tel debris disk is reminiscent of the Solar System, suggesting that this is a young Solar System analogue. For an age of 12Myr, both the radius and dust level of the extended cooler component are consistent with self-stirring models for a protoplanetary disk of 0.7 times minimum mass solar nebula. The origin of the hot dust component may arise in an asteroid belt undergoing collisional destruction, or in massive collisions in ongoing terrestrial planet formation.

R. Smith; L. J. Churcher; M. C. Wyatt; M. M. Moerchen; C. M. Telesco

2008-10-28T23:59:59.000Z

Note: This page contains sample records for the topic "fugitive dust emissions" 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

THE MASS-LOSS RETURN FROM EVOLVED STARS TO THE LARGE MAGELLANIC CLOUD. II. DUST PROPERTIES FOR OXYGEN-RICH ASYMPTOTIC GIANT BRANCH STARS  

SciTech Connect (OSTI)

We model multi-wavelength broadband UBVIJHK{sub s} and Spitzer IRAC and MIPS photometry and Infrared Spectrograph spectra from the SAGE and SAGE-Spectroscopy observing programs of two oxygen-rich asymptotic giant branch (O-rich AGB) stars in the Large Magellanic Cloud (LMC) using radiative transfer (RT) models of dust shells around stars. We chose a star from each of the bright and faint O-rich AGB populations found by earlier studies of the SAGE sample in order to derive a baseline set of dust properties to be used in the construction of an extensive grid of RT models of the O-rich AGB stars found in the SAGE surveys. From the bright O-rich AGB population, we chose HV 5715, and from the faint O-rich AGB population we chose SSTISAGE1C J052206.92-715017.6 (SSTSAGE052206). We found the complex indices of refraction of oxygen-deficient silicates from Ossenkopf et al. and a power law with exponential decay grain size distribution like what Kim et al. used but with {gamma} of -3.5, a {sub min} of 0.01 {mu}m, and a {sub 0} of 0.1 {mu}m to be reasonable dust properties for these models. There is a slight indication that the dust around the faint O-rich AGB may be more silica-rich than that around the bright O-rich AGB. Simple models of gas emission suggest a relatively extended gas envelope for the faint O-rich AGB star modeled, consistent with the relatively large dust shell inner radius for the same model. Our models of the data require the luminosity of SSTSAGE052206 and HV 5715 to be {approx}5100 L {sub sun} and {approx}36,000 L {sub sun}, respectively. This, combined with the stellar effective temperatures of 3700 K and 3500 K, respectively, that we find best fit the optical and near-infrared data, suggests stellar masses of {approx}3 M {sub sun} and {approx}7 M {sub sun}. This, in turn, suggests that HV 5715 is undergoing hot-bottom burning and that SSTSAGE052206 is not. Our models of SSTSAGE052206 and HV 5715 require dust shells of inner radius {approx}17 and {approx}52 times the stellar radius, respectively, with dust temperatures there of 900 K and 430 K, respectively, and with optical depths at 10 {mu}m through the shells of 0.095 and 0.012, respectively. The models compute the dust mass-loss rates for the two stars to be 2.0 x 10{sup -9} M{sub sun} yr{sup -1} and 2.3 x 10{sup -9} M{sub sun} yr{sup -1}, respectively. When a dust-to-gas mass ratio of 0.002 is assumed for SSTSAGE052206 and HV 5715, the dust mass-loss rates imply total mass-loss rates of 1.0 x 10{sup -6} M{sub sun} yr{sup -1} and 1.2 x 10{sup -6} M{sub sun} yr{sup -1}, respectively. These properties of the dust shells and stars, as inferred from our models of the two stars, are found to be consistent with properties observed or assumed by detailed studies of other O-rich AGB stars in the LMC and elsewhere.

Sargent, Benjamin A.; Meixner, M.; Gordon, Karl D. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Srinivasan, S. [Institut d'Astrophysique de Paris, 98 bis, Boulevard Arago, Paris 75014 (France); Kemper, F.; Woods, Paul M. [Jodrell Bank Centre for Astrophysics, Alan Turing Building, School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester, M13 9PL (United Kingdom); Tielens, A. G. G. M. [Leiden Observatory, P.O. Box 9513, NL-2300 RA Leiden (Netherlands); Speck, A. K. [Physics and Astronomy Department, University of Missouri, Columbia, MO 65211 (United States); Matsuura, M. [Institute of Origins, Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Bernard, J.-Ph. [Centre d'Etude Spatiale des Rayonnements, 9 Av. du Colonel Roche, BP 44346, 31028 Toulouse Cedex 4 (France); Hony, S. [Laboratoire AIM, CEA/DSM-CNRS-Universite Paris Diderot DAPNIA/Service d'Astrophysique Bat. 709, CEA-Saclay F-91191 Gif-sur-Yvette Cedex (France); Indebetouw, R. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904 (United States); Marengo, M. [Department of Physics and Astronomy, Iowa State University, Ames, IA 50011 (United States); Sloan, G. C., E-mail: sargent@stsci.ed [Department of Astronomy, Cornell University, Ithaca, NY 14853 (United States)

2010-06-10T23:59:59.000Z

342

A NEW VIEW ON INTERSTELLAR DUST HIGH FIDELITY STUDIES OF INTERSTELLAR DUST ANALOGUE TRACKS IN STARDUST FLIGHT SPARE AEROGEL  

E-Print Network [OSTI]

IN STARDUST FLIGHT SPARE AEROGEL F. Postberg, C. Allen, S. Bajt, H. A. Bechtel, J. Borg, F. Brenker, J the Stardust Mission exposed aerogel collector panels for a total of about 200 days to the stream - 30km/s] interstellar dust (ISD) analogues onto Stardust aerogel flight spares. This en- ables

343

Saving Fuel, Reducing Emissions  

E-Print Network [OSTI]

would in turn lower PHEV fuel costs and make them morestretches from fossil-fuel- powered conventional vehiclesbraking, as do Saving Fuel, Reducing Emissions Making Plug-

Kammen, Daniel M.; Arons, Samuel M.; Lemoine, Derek M.; Hummel, Holmes

2009-01-01T23:59:59.000Z

344

Vehicle Emissions Review - 2012  

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

Vehicle Emissions Review - 2012 Tim Johnson October 16, 2012 2 Environmental Technologies Summary * Regulations - LEVIII finalized, Tier 3? RDE in Europe developing and very...

345

Method and apparatus for measuring surface density of explosive and inert dust in stratified layers  

DOE Patents [OSTI]

A method for determining the surface density of coal dust on top of rock dust or rock dust on top of coal dust is disclosed which comprises directing a light source at either a coal or rock dust layer overlaying a substratum of the other, detecting the amount of light reflected from the deposit, generating a signal from the reflected light which is converted into a normalized output (V), and calculating the surface density from the normalized output. The surface density S.sub.c of coal dust on top of rock dust is calculated according to the equation: S.sub.c =1/-a.sub.c ln(V) wherein a.sub.c is a constant for the coal dust particles, and the surface density S.sub.r of rock dust on top of coal dust is determined by the equation: ##EQU1## wherein a.sub.r is a constant based on the properties of the rock dust particles. An apparatus is also disclosed for carrying out the method of the present invention.

Sapko, Michael J. (Finleyville, PA); Perlee, Henry E. (Bethel Park, PA)

1988-01-01T23:59:59.000Z

346

Dust acoustic solitary and shock excitations in a Thomas-Fermi magnetoplasma  

SciTech Connect (OSTI)

The linear and nonlinear properties of dust-acoustic waves are investigated in a collisionless Thomas-Fermi magnetoplasma, whose constituents are electrons, ions, and negatively charged dust particles. At dust time scale, the electron and ion number densities follow the Thomas-Fermi distribution, whereas the dust component is described by the classical fluid equations. A linear dispersion relation is analyzed to show that the wave frequencies associated with the upper and lower modes are enhanced with the variation of dust concentration. The effect of the latter is seen more strongly on the upper mode as compared to the lower mode. For nonlinear analysis, we obtain magnetized Korteweg-de Vries (KdV) and Zakharov-Kuznetsov (ZK) equations involving the dust-acoustic solitary waves in the framework of reductive perturbation technique. Furthermore, the shock wave excitations are also studied by allowing dissipation effects in the model, leading to the Korteweg-de Vries-Burgers (KdVB) and ZKB equations. The analysis reveals that the dust-acoustic solitary and shock excitations in a Thomas-Fermi plasma are strongly influenced by the plasma parameters, e.g., dust concentration, dust temperature, obliqueness, magnetic field strength, and dust fluid viscosity. The present results should be important for understanding the solitary and shock excitations in the environments of white dwarfs or supernova, where dust particles can exist.

Rahim, Z.; Qamar, A. [Institute of Physics and Electronics, University of Peshawar, Peshawar 25000 (Pakistan); National Center for Physics (NCP) at QAU Campus, Shahdra Valley Road, Islamabad 44000 (Pakistan); Ali, S. [National Center for Physics (NCP) at QAU Campus, Shahdra Valley Road, Islamabad 44000 (Pakistan)

2014-07-15T23:59:59.000Z

347

Dust-acoustic waves in nonuniform dusty plasma in presence of polarization force  

SciTech Connect (OSTI)

The effects of the dust density nonuniformity and the polarization force on linear propagation of the dust-acoustic waves in a nonuniform dusty plasma (consisting of electrons, ions, and arbitrarily charged dust particles) have been theoretically investigated. It has been shown that the linear dispersion properties of the dust-acoustic (DA) waves have been significantly modified by the dust density nonuniformity, dust polarity, and the polarization force. It is also found here that the phase speed of the DA waves is decreased by the effects of polarization force, and that their amplitude increases with the decrease of equilibrium dust number density. The different situations, which are relevant to different space and laboratory dusty plasmas, have been briefly discussed.

Asaduzzaman, M.; Mamun, A. A.; Ashrafi, K. S. [Department of Physics, Jahangirnagar University, Savar, Dhaka-1342 (Bangladesh)

2011-11-15T23:59:59.000Z

348

Air Emission Inventory for the INEEL -- 1999 Emission Report  

SciTech Connect (OSTI)

This report presents the 1999 calendar year update of the Air Emission Inventory for the Idaho National Engineering and Environmental Laboratory (INEEL). The INEEL Air Emission Inventory documents sources and emissions of nonradionuclide pollutants from operations at the INEEL. The report describes the emission inventory process and all of the sources at the INEEL, and provides nonradionuclide emissions estimates for stationary sources.

Zohner, Steven K

2000-05-01T23:59:59.000Z

349

MIE and Flame velocity of partially oxidised aluminium dust Stphane Bernard, Philippe Gillard, Fabrice Foucher, Christine Mounam-Rousselle  

E-Print Network [OSTI]

present dust explosion hazards. The prevention of these hazards can be achieved by the characterisation in the oxide shell which increases the reactivity of the oxidised aluminium dust. Keywords : DUST EXPLOSIONSMIE and Flame velocity of partially oxidised aluminium dust Stéphane Bernard, Philippe Gillard

Paris-Sud XI, Université de

350

Consequences of three-dimensional physical and electromagnetic structures on dust particle trapping in high plasma density  

E-Print Network [OSTI]

gradients are present, which introduce fluid drag and thermophoretic forces, dust particle traps may

Kushner, Mark

351

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

SciTech Connect (OSTI)

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

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

2013-09-01T23:59:59.000Z

352

First-light LBT nulling interferometric observations: warm exozodiacal dust resolved within a few AU of eta Corvi  

E-Print Network [OSTI]

We report on the first nulling interferometric observations with the Large Binocular Telescope Interferometer (LBTI), resolving the N' band (9.81 - 12.41 um) emission around the nearby main-sequence star eta Crv (F2V, 1-2 Gyr). The measured source null depth amounts to 4.40% +/- 0.35% over a field-of-view of 140 mas in radius (~2.6\\,AU at the distance of eta Corvi) and shows no significant variation over 35{\\deg} of sky rotation. This relatively low null is unexpected given the total disk to star flux ratio measured by Spitzer/IRS (~23% across the N' band), suggesting that a significant fraction of the dust lies within the central nulled response of the LBTI (79 mas or 1.4 AU). Modeling of the warm disk shows that it cannot resemble a scaled version of the Solar zodiacal cloud, unless it is almost perpendicular to the outer disk imaged by Herschel. It is more likely that the inner and outer disks are coplanar and the warm dust is located at a distance of 0.5-1.0 AU, significantly closer than previously predic...

Defrère, D; Skemer, A J; Kennedy, G M; Bailey, V P; Hoffmann, W F; Mennesson, B; Millan-Gabet, R; Danchi, W C; Absil, O; Arbo, P; Beichman, C; Brusa, G; Bryden, G; Downey, E C; Durney, O; Esposito, S; Gaspar, A; Grenz, P; Haniff, C; Hill, J M; Lebreton, J; Leisenring, J M; Males, J R; Marion, L; McMahon, T J; Montoya, M; Morzinski, K M; Pinna, E; Puglisi, A; Rieke, G; Roberge, A; Serabyn, E; Sosa, R; Stapeldfeldt, K; Su, K; Vaitheeswaran, V; Vaz, A; Weinberger, A J; Wyatt, M C

2015-01-01T23:59:59.000Z

353

Color-based tracking of plasma dust particles  

SciTech Connect (OSTI)

Color-based tracking to observe agglomeration of deposited particles inside a compact planar magnetron during plasma discharge was done by creating high dynamic range (HDR) images of photos captured by a Pentax K10D digital camera. Carbon erosion and redeposition was also monitored using the technique. The HDR images were subjected to a chromaticity-based constraint discoloration inside the plasma chamber indicating film formation or carbon redeposition. Results show that dust deposition occurs first near the evacuation pumps due to the pressure gradient and then accumulates at the positively charged walls of the chamber. This method can be applied to monitor dust formation during dusty plasma experiments without major modification of plasma devices, useful especially for large fusion reactors.

Villamayor, Michelle Marie S., E-mail: mvillamayor@nip.upd.edu.ph; Soriano, Maricor N.; Ramos, Henry J. [National Institute of Physics, University of the Philippines, Diliman, Quezon City 1101 (Philippines)] [National Institute of Physics, University of the Philippines, Diliman, Quezon City 1101 (Philippines); Kato, Shuichi; Wada, Motoi [Graduate School of Engineering, Doshisha University, Kyotanabe, Kyoto 610-0321 (Japan)] [Graduate School of Engineering, Doshisha University, Kyotanabe, Kyoto 610-0321 (Japan)

2014-02-15T23:59:59.000Z

354

Spherically symmetric cosmological spacetimes with dust and radiation — numerical implementation  

SciTech Connect (OSTI)

We present new numerical cosmological solutions of the Einstein Field Equations. The spacetime is spherically symmetric with a source of dust and radiation approximated as a perfect fluid. The dust and radiation are necessarily non-comoving due to the inhomogeneity of the spacetime. Such a model can be used to investigate non-linear general relativistic effects present during decoupling or big-bang nucleosynthesis, as well as for investigating void models of dark energy with isocurvature degrees of freedom. We describe the full evolution of the spacetime as well as the redshift and luminosity distance for a central observer. After demonstrating accuracy of the code, we consider a few example models, and demonstrate the sensitivity of the late time model to the degree of inhomogeneity of the initial radiation contrast.

Lim, Woei Chet [Department of Mathematics, University of Waikato, Private Bag 3105, Hamilton 3240 (New Zealand); Regis, Marco [Dipartimento di Fisica, Università di Torino and INFN, Torino (Italy); Clarkson, Chris, E-mail: wclim@waikato.ac.nz, E-mail: regis@to.infn.it, E-mail: chris.clarkson@gmail.com [Astrophysics, Cosmology and Gravity Centre, and Department of Mathematics and Applied Mathematics, University of Cape Town, Rondebosch 7701, Cape Town (South Africa)

2013-10-01T23:59:59.000Z

355

Modelling the effects of dust on galaxy spectra Miller Crawford  

E-Print Network [OSTI]

of a double exponential: ae d = ae 0 exp (\\GammaR=R d ) exp (\\Gammajzj=z d ) where z = r cos ` The bulge is given by a King profile: ae b = ae 0 h 1 + i r r c j 2 i \\Gammafl where fl = 3=2 (stars) and fl = 3=4(dust) Disks are truncated at R gal = 6R d , and bulges are truncated at the tidal radius R t = 10 2:2 r

Tittley, Eric

356

Spitzer Detection of PAH and Silicate Dust Features in the Mid-Infrared Spectra of z~2 Ultraluminous Infrared Galaxies  

E-Print Network [OSTI]

We report the initial results from a Spitzer GO-1 program to obtain low resolution, mid-infrared spectra of infrared luminous galaxies at z~1-2. This paper presents the spectra of eight sources observed with the Spitzer InfraRed Spectrograph (IRS). Of the eight spectra, six have mid-IR spectral features, either emission from Polycyclic Aromatic Hydrocarbon (PAH) or silicate absorption. Based on these mid-IR features, the inferred six redshifts are in the range of 1.8-2.6. The remaining two spectra detect only strong continua, thus do not yield redshift information. Strong, multiple PAH emission features are detected in two sources, and weak PAH emission in another two. These data provide direct evidence that PAH molecules are present and directly observable in ULIRGs at z~2. The six sources with measured redshifts are dusty, infrared luminous galaxies at z~2 with estimated $L_{bol} \\sim 10^{13}L_\\odot$. Of the eight sources, two appear starburst dominated; two with only power law continua are probably type I QSOs; and the remaining four are likely composite systems containing a buried AGN and a starburst component. Since half of our sample are optically faint sources with R>25.5mag (Vega), our results demonstrate the potential of using mid-infrared spectroscopy, especially the Aromatic and silicate features produced by dust grains to directly probe optically faint and infrared luminous populations at high redshift.

Lin Yan; R. Chary; L. Armus; H. Teplitz; G. Helou; D. Frayer; D. Fadda; J. Surace; P. Choi

2005-04-14T23:59:59.000Z

357

Spontaneous Emission Rate Enhancement Using Optical Antennas  

E-Print Network [OSTI]

of  Spontaneous  Emission  in  a  Semiconductor  nanoLED,”  emission  rate  enhancement  using  the  Fluorescent  Emission  by  Lattice   Resonances  in  

Kumar, Nikhil

2013-01-01T23:59:59.000Z

358

Raman Spectroscopy of Carbon Dust Samples from NSTX  

SciTech Connect (OSTI)

The Raman spectrum of dust particles exposed to the NSTX plasma is different from the spectrum of unexposed particles scraped from an unused graphite tile. For the unexposed particles, the high energy G-mode peak (Raman shift ~1580 cm-1) is much stronger than the defect-induced D-mode peak (Raman shift ~ 1350 cm-1), a pattern that is consistent with Raman spectrum for commercial graphite materials. For dust particles exposed to the plasma, the ratio of G-mode to D-mode peaks is lower and becomes even less than 1. The Raman measurements indicate that the production of carbon dust particles in NSTX involves modifications of the physical and chemical structure of the original graphite material. These modifications are shown to be similar to those measured for carbon deposits from atmospheric pressure helium arc discharge with an ablating anode electrode made from a graphite tile material. We also demonstrate experimentally that heating to 2000-2700 K alone can not explain the observed structural modifications indicating that they must be due to higher temperatures needed for graphite vaporization, which is followed either by condensation or some plasma-induced processes leading to the formation of more disordered forms of carbon material than the original graphite.

Y. Raitses, C.H. Skinner, F. Jiang and T.S. Duffy

2008-02-21T23:59:59.000Z

359

On the Crystallinity of Silicate Dust in the Interstellar Medium  

E-Print Network [OSTI]

An accurate knowledge of the mineralogy (chemical composition and crystal structure) of the silicate dust in the interstellar medium (ISM) is crucial for understanding its origin in evolved stars, the physical and chemical processing in the ISM, and its subsequent incorporation into protostellar nebulae, protoplanetary disks and cometary nuclei where it is subjected to further processing. While an appreciable fraction of silicate dust in evolved stars, in protoplanetary disks around pre-main sequence stars, in debris disks around main sequence stars, and in cometary nuclei is found to be in crystalline form, very recent infrared spectroscopic studies of the dust along the sightline toward the Galactic center source Sgr A* placed an upper limit of ~1.1% on the silicate crystalline fraction, well below the previous estimates of ~5% or ~60% derived from the observed 10 micron absorption profile for the local ISM toward Cyg OB2 No.12. Since the sightline toward SgrA contains molecular cloud materials as revealed by the detection of the 3.1 and 6.0 micron water ice absorption features, we argue that by taking into account the presence of ice mantles on silicate cores, the upper limit on the degree of silicate crystallinity in the ISM is increased to ~3--5%.

M. P. Li; G. Zhao; Aigen Li

2008-08-29T23:59:59.000Z

360

GRAIN SORTING IN COMETARY DUST FROM THE OUTER SOLAR NEBULA  

SciTech Connect (OSTI)

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

Note: This page contains sample records for the topic "fugitive dust emissions" 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

Dust Masses, PAH Abundances, and Starlight Intensities in the SINGS Galaxy Sample  

E-Print Network [OSTI]

Physical dust models are presented for 65 galaxies in the SINGS survey that are strongly detected in the four IRAC bands and three MIPS bands. For each galaxy we estimate (1) the total dust mass, (2) the fraction of the dust mass contributed by PAHs, and (3) the intensity of the starlight heating the dust grains. We find that spiral galaxies have dust properties resembling the dust in the local region of the Milky Way, with similar dust-to-gas ratio, and similar PAH abundance. The observed SEDs, including galaxies with SCUBA photometry, can be reproduced by dust models that do not require "cold" (T8.1, grains contain a substantial fraction of interstellar Mg, Si and Fe. Galaxies with A_O8.1 have a median q_PAH=3.55%. The derived dust masses favor a value X_CO approx 4e20 cm^{-2}(K kms)^{-1} for the CO to H_2 conversion factor. Except for some starbursting systems (Mrk33, Tolo89, NGC3049), dust in the diffuse ISM dominates the IR power.

Draine, B T; Bendo, G; Gordon, K D; Smith, J D T; Armus, L; Engelbracht, C W; Helou, G; Kennicutt, R C; Li, A; Roussel, H; Walter, F; Calzetti, D; Moustakas, J; Murphy, E J; Rieke, G H; Bot, C; Hollenbach, D J; Sheth, K; Teplitz, H I

2007-01-01T23:59:59.000Z

362

Dust Masses, PAH Abundances, and Starlight Intensities in the SINGS Galaxy Sample  

E-Print Network [OSTI]

Physical dust models are presented for 65 galaxies in the SINGS survey that are strongly detected in the four IRAC bands and three MIPS bands. For each galaxy we estimate (1) the total dust mass, (2) the fraction of the dust mass contributed by PAHs, and (3) the intensity of the starlight heating the dust grains. We find that spiral galaxies have dust properties resembling the dust in the local region of the Milky Way, with similar dust-to-gas ratio, and similar PAH abundance. The observed SEDs, including galaxies with SCUBA photometry, can be reproduced by dust models that do not require "cold" (Tmedia of galaxies with A_O=12+log(O/H)>8.1, grains contain a substantial fraction of interstellar Mg, Si and Fe. Galaxies with A_O8.1 have a median q_PAH=3.55%. The derived dust masses favor a value X_CO approx 4e20 cm^{-2}(K kms)^{-1} for the CO to H_2 conversion factor. Except for some starbursting systems (Mrk33, Tolo89, NGC3049), dust in the diffuse ISM dominates the IR power.

B. T. Draine; D. A. Dale; G. Bendo; K. D. Gordon; J. D. T. Smith; L. Armus; C. W. Engelbracht; G. Helou; R. C. Kennicutt; A. Li; H. Roussel; F. Walter; D. Calzetti; J. Moustakas; E. J. Murphy; G. H. Rieke; C. Bot; D. J. Hollenbach; K. Sheth; H. I. Teplitz

2007-03-09T23:59:59.000Z

363

Characteristics of PCDD/F distributions in vapor and solid phases and emissions from the Waelz process  

SciTech Connect (OSTI)

The Waelz process is a classic method used for recovering zinc from electric arc furnace (EAF) dusts containing relatively high concentrations of PCDD/Fs (polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans) as well as volatile metals, such as Zn, Pb, and Cu, and chlorine. The EAF dust is mixed with coke (30%) and sand (20%) then fed into a rotary kiln. Significant PCDD/Fs are formed in the typical Waelz process, causing public concerns regarding PCDD/F emissions. In this study, flue gas and ash samplings are simultaneously conducted at different sampling points to evaluate the removal efficiency and the partitioning of PCDD/Fs between the vapor and solid phases in the Waelz plant investigated. With the environment (temperature window, sufficient retention time, chlorine, and catalysts available) conducive to PCDD/F formation in the dust settling chamber (DSC), a significantly high PCDD/F concentration (1223 ng TEQ/Nm{sup 3}) is measured in flue gas downstream from the DSC of the Waelz plant investigated. In addition, the cyclone and bag filter adopted in this facility can only remove 51.3% and 69.4%, respectively, of the PCDD/Fs in the flue gas, resulting in a high PCDD/F concentration (145 ng TEQ/Nm{sup 3}) measured in the stack gas of the Waelz plant investigated. On the basis of treating 1 ton of EAF dust, the total PCDD/F discharge (stack gas emission + ash discharge) is 840 ng TEQ/kg EAF dust of the Waelz plant investigated. Because of the lack of effective air pollutant control devices for PCDD/Fs, about 560 ng TEQ/kg EAF dust are discharged via stack gas in this facility. 16 refs., 7 figs., 2 tabs.

Kai Hsien Chi; Shu Hao Chang; Moo Been Chang [National Central University, Chungli (Taiwan). Graduate Institute of Environmental Engineering

2006-03-15T23:59:59.000Z

364

Regional Modeling of Dust Mass Balance and Radiative Forcing over East Asia using WRF-Chem  

SciTech Connect (OSTI)

The Weather Research and Forecasting model with Chemistry (WRF-Chem) is used to investigate the seasonal and annual variations of mineral dust over East Asia during 2007-2011, with a focus on the dust mass balance and radiative forcing. A variety of measurements from in-stu and satellite observations have been used to evaluate simulation results. Generally, WRF-Chem reproduces not only the column variability but also the vertical profile and size distribution of mineral dust over and near the dust source regions of East Asia. We investigate the dust lifecycle and the factors that control the seasonal and spatial variations of dust mass balance and radiative forcing over the seven sub-regions of East Asia, i.e. source regions, the Tibetan Plateau, Northern China, Southern China, the ocean outflow region, and Korea-Japan regions. Results show that, over the source regions, transport and dry deposition are the two dominant sinks. Transport contributes to ~30% of the dust sink over the source regions. Dust results in a surface cooling of up to -14 and -10 W m-2, atmospheric warming of up to 20 and 15 W m-2, and TOA cooling of -5 and -8 W m-2 over the two major dust source regions of East Asia, respectively. Over the Tibetan Plateau, transport is the dominant source with a peak in summer. Over identified outflow regions, maximum dust mass loading in spring is contributed by the transport. Dry and wet depositions are the comparably dominant sinks, but wet deposition is larger than dry deposition over the Korea-Japan region, particularly in spring (70% versus 30%). The WRF-Chem simulations can generally capture the measured features of dust aerosols and its radaitve properties and dust mass balance over East Asia, which provides confidence for use in further investigation of dust impact on climate over East Asia.

Chen, Siyu; Zhao, Chun; Qian, Yun; Leung, Lai-Yung R.; Huang, J.; Huang, Zhongwei; Bi, Jianrong; Zhang, Wu; Shi, Jinsen; Yang, Lei; Li, Deshuai; Li, Jinxin

2014-12-01T23:59:59.000Z

365

Contraction & Convergence: UK carbon emissions and the  

E-Print Network [OSTI]

the EU's emissions trading scheme will do little to mitigate carbon emissions 4) Aviation growth must emissions. Keywords Contraction & Convergence; aviation; emissions trading; passengers; carbon dioxide #12

Watson, Andrew

366

Emission Abatement System  

DOE Patents [OSTI]

Emission abatement system. The system includes a source of emissions and a catalyst for receiving the emissions. Suitable catalysts are absorber catalysts and selective catalytic reduction catalysts. A plasma fuel converter generates a reducing gas from a fuel source and is connected to deliver the reducing gas into contact with the absorber catalyst for regenerating the catalyst. A preferred reducing gas is a hydrogen rich gas and a preferred plasma fuel converter is a plasmatron. It is also preferred that the absorber catalyst be adapted for absorbing NO.sub.x.

Bromberg, Leslie (Sharon, MA); Cohn, Daniel R. (Chestnut Hill, MA); Rabinovich, Alexander (Swampscott, MA)

2003-05-13T23:59:59.000Z

367

Spitzer Observations of Var Her 04: Possible Detection of Dust Formation in a Super-Outbursting TOAD  

E-Print Network [OSTI]

We present four MIPS (24 \\micron) and two IRAC (3.6, 4.5, 5.8, and 8.0 \\micron) Spitzer observations of the newly discovered Tremendous Outburst Amplitude Dwarf nova (TOAD) Var Her 04 during decline from super-outburst. The four MIPS observations span 271 days and the two IRAC observations span 211 days. Along the line-of-sight to Var Her 04, there is a foreground M-star within 1\\arcsec of the variable; as a result, all of the Spitzer photometry presented in this paper is a blend of the foreground M-star and Var Her 04. We estimate the quiescent level of the TOAD to be $\\Delta V=4-5$ magnitudes below that of the M-star. Based upon the spectral energy distribution and the 2MASS colors, we find the M-star to be an M3.5V dwarf at a distance of 80-130 pc. Based upon its outburst amplitude and quiescent apparent magnitude, we estimate the distance to Var Her 04 to be 200-400 pc, suggesting that the line-of-sight foreground star is physically unrelated to the cataclysmic variable. All of the Spitzer photometry is consistent with the photospheric emission of the line-of-sight M3.5V star, except for one 24 \\micron observation obtained after the variable re-brightened. This 24 \\micron flux density is 75 $\\mu$Jy ($4\\sigma$) above the preceding and following MIPS observations. We tentatively suggest that the mid-infrared brightening of 75 $\\mu$Jy may be associated with a dust formation event in the super-outburst ejecta. Assuming a dust temperature of 100-400 K, we have estimated the amount of dust required. We find $10^{-13}-10^{-11}$ M$_\\odot$ of dust is needed, consistent with amounts of mass ejection in TOADs expected during super-outburst, and possibly making TOADs important contributors to the recycling of the interstellar medium.

David R. Ciardi; Stefanie Wachter; D. W. Hoard; Steve B. Howell; Gerard T. van Belle

2006-08-03T23:59:59.000Z

368

Emission Standards for Contaminants (Iowa)  

Broader source: Energy.gov [DOE]

These regulations list emissions standards for various contaminants, and contain special requirements for anaerobic lagoons. These regulations also describe alternative emissions limits, which may...

369

"Dust, Ice, and Gas In Time" (DIGIT) Herschel Observations of GSS30-IRS1 in Ophiuchus  

E-Print Network [OSTI]

As a part of the "Dust, Ice, and Gas In Time" (DIGIT) key program on Herschel, we observed GSS30-IRS1, a Class I protostar located in Ophiuchus (d = 120 pc), with Herschel/Photodetector Array Camera and Spectrometer (PACS). More than 70 lines were detected within a wavelength range from 50 micron to 200 micron, including CO, H2O, OH, and two atomic [O I] lines at 63 and 145 micron. The [C II] line, known as a tracer of externally heated gas by the interstellar radiation field, is also detected at 158 micron. All lines, except [O I] and [C II], are detected only at the central spaxel of 9.4" X 9.4". The [O I] emissions are extended along a NE-SW orientation, and the [C II] line is detected over all spaxels, indicative of external PDR. The total [C II] intensity around GSS30 reveals that the far-ultraviolet radiation field is in the range of 3 to 20 G0, where G0 is in units of the Habing Field, 1.6 X 10^{-3} erg cm^{-2} s^{-1}. This enhanced external radiation field heats the envelope of GSS30-IRS1, causing the...

Je, Hyerin; Lee, Seokho; Green, Joel D; Evans, Neal J

2015-01-01T23:59:59.000Z

370

Intelligent field emission arrays  

E-Print Network [OSTI]

Field emission arrays (FEAs) have been studied extensively as potential electron sources for a number of vacuum microelectronic device applications. For most applications, temporal current stability and spatial current ...

Hong, Ching-yin, 1973-

2003-01-01T23:59:59.000Z

371

Photon enhanced thermionic emission  

DOE Patents [OSTI]

Photon Enhanced Thermionic Emission (PETE) is exploited to provide improved efficiency for radiant energy conversion. A hot (greater than 200.degree. C.) semiconductor cathode is illuminated such that it emits electrons. Because the cathode is hot, significantly more electrons are emitted than would be emitted from a room temperature (or colder) cathode under the same illumination conditions. As a result of this increased electron emission, the energy conversion efficiency can be significantly increased relative to a conventional photovoltaic device. In PETE, the cathode electrons can be (and typically are) thermalized with respect to the cathode. As a result, PETE does not rely on emission of non-thermalized electrons, and is significantly easier to implement than hot-carrier emission approaches.

Schwede, Jared; Melosh, Nicholas; Shen, Zhixun

2014-10-07T23:59:59.000Z

372

Greenhouse Gas Emissions (Minnesota)  

Broader source: Energy.gov [DOE]

This statute sets goals for the reduction of statewide greenhouse gas emissions by at least 15 percent by 2015, 30 percent by 2025, and 80 percent by 2050, calculated relative to 2005 levels. These...

373

Field emission electron source  

DOE Patents [OSTI]

A novel field emitter material, field emission electron source, and commercially feasible fabrication method is described. The inventive field emission electron source produces reliable electron currents of up to 400 mA/cm.sup.2 at 200 volts. The emitter is robust and the current it produces is not sensitive to variability of vacuum or the distance between the emitter tip and the cathode. The novel emitter has a sharp turn-on near 100 volts.

Zettl, Alexander Karlwalter (Kensington, CA); Cohen, Marvin Lou (Berkeley, CA)

2000-01-01T23:59:59.000Z

374

Microsoft Word - DOE-ID-INL-13-024.docx  

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

must be minimized in accordance with the methods specified in Rules for the Control of Air Pollution in Idaho (IDAPA 58.01.01.650-651). Steps taken to control fugitive dust at...

375

E-Print Network 3.0 - ambient urban levels Sample Search Results  

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

Summary: that seven major sources of ambient PM10 were urban fugitive dust, crustal soil, coal combustion, secondary... diameter of 10 m or less) exceeded the level II of...

376

Wildland fire emissions, carbon, and climate: Emission factors Shawn Urbanski  

E-Print Network [OSTI]

Wildland fire emissions, carbon, and climate: Emission factors Shawn Urbanski Missoula Fire burning Greenhouse gases Emission factors a b s t r a c t While the vast majority of carbon emitted wildland fire greenhouse gas and aerosol (organic aerosol (OA) and black carbon (BC)) emission inventories

377

Generation of dust projectiles passing over an obstacle in the plasma sheath  

SciTech Connect (OSTI)

Dust projectiles were produced in a radio-frequency plasma by increasing 6-fold the radio-frequency power put into the discharge. The initial static dust particles were observed to gain speed while moving away from the confining region and escaped from the inter-electrode space on a ballistic-like trajectory. Single-grain dynamics simulations indicated that the dust particles were accelerated by changes induced in the sheath electric field profile.

Ticos, Catalin M.; Stoica, Daniel S. [National Institute for Laser, Plasma and Radiation Physics, 077125 Bucharest (Romania); Delzanno, Gian Luca [Los Alamos National Laboratory, T-5 Applied Mathematics and Plasma Physics Group, Los Alamos, New Mexico 87545 (United States)

2012-08-15T23:59:59.000Z

378

Dust suppression results using mineral oil applications on corn and milo  

E-Print Network [OSTI]

distribution (MCPSD) analysis, to determine the amount and particle size of the dust captured on the grain surface. Statistical analyses were performed on the effects due to dust concentration, mineral oil application and mineral oil*dust interaction. Each... TO CORN BENEFITS OF ADDING MINERAL OIL TO MILO 96 . 97 23 TREATMENT DESCRIPTION OP CORN SAMPLES USED FOR TESTING. 104 TREATMENT DESCRIPTION OF MILO SAMPLES USED FOR TESTING, . . . . . . . . . . . . . . PARTICLE SIZE DISTRIBUTION STATISTICS...

Wardlaw, Herman Douglas

1987-01-01T23:59:59.000Z

379

A Fluorescent Aerogel for Capture and Identification of Interplanetary and Interstellar Dust  

E-Print Network [OSTI]

Contemporary interstellar dust has never been analyzed in the laboratory, despite its obvious astronomical importance and its potential as a probe of stellar nucleosynthesis and galactic chemical evolution. Here we report the discovery of a novel fluorescent aerogel which is capable of capturing hypervelocity dust grains and passively recording their kinetic energies. An array of these "calorimetric" aerogel collectors in low earth orbit would lead to the capture and identification of large numbers of interstellar dust grains.

Gerardo Dominguez; Andrew J. Westphal; Mark L. F. Phillips; Steven M. Jones

2003-03-27T23:59:59.000Z

380

A New Facility for Studying Shock Wave Passage over Dust Layers  

E-Print Network [OSTI]

A NEW FACILITY FOR STUDYING SHOCK WAVE PASSAGE OVER DUST LAYERS A Thesis by BRANDON DAVID MARKS Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree... Brandon David Marks ii ABSTRACT To ensure safety regarding dust explosion hazards, it is important to study the dust lifting process experimentally and identify important parameters that will be valuable for development and validation...

Marks, Brandon

2013-05-30T23:59:59.000Z

Note: This page contains sample records for the topic "fugitive dust emissions" 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

SPITZER INFRARED SPECTROGRAPH SPECTROSCOPY OF THE 10 Myr OLD EF Cha DEBRIS DISK: EVIDENCE FOR PHYLLOSILICATE-RICH DUST IN THE TERRESTRIAL ZONE  

SciTech Connect (OSTI)

We describe Spitzer Infrared Spectrograph spectroscopic observations of the {approx}10 Myr old star, EF Cha. Compositional modeling of the spectra from 5 {mu}m to 35 {mu}m confirms that it is surrounded by a luminous debris disk with L{sub D} /L{sub *} {approx} 10{sup -3}, containing dust with temperatures between 225 K and 430 K, characteristic of the terrestrial zone. The EF Cha spectrum shows evidence for many solid-state features, unlike most cold, low-luminosity debris disks but like some other 10-20 Myr old luminous, warm debris disks (e.g., HD 113766A). The EF Cha debris disk is unusually rich in a species or combination of species whose emissivities resemble that of finely powdered, laboratory-measured phyllosilicate species (talc, saponite, and smectite), which are likely produced by aqueous alteration of primordial anhydrous rocky materials. The dust and, by inference, the parent bodies of the debris also contain abundant amorphous silicates and metal sulfides, and possibly water ice. The dust's total olivine to the pyroxene ratio of {approx}2 also provides evidence of aqueous alteration. The large mass volume of grains with sizes comparable to or below the radiation blow-out limit implies that planetesimals may be colliding at a rate high enough to yield the emitting dust but not so high as to devolatize the planetesimals via impact processing. Because phyllosilicates are produced by the interactions between anhydrous rock and warm, reactive water, EF Cha's disk is a likely signpost for water delivery to the terrestrial zone of a young planetary system.

Currie, Thayne [NASA-Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Lisse, Carey M. [Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723-6099 (United States); Sicilia-Aguilar, Aurora [Max-Planck-Institute for Astronomy, Koenigstuhl 17, 69117 Heidelberg (Germany); Rieke, George H.; Su, Kate Y. L. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Rm. N204, Tucson, AZ 85721-0065 (United States)

2011-06-20T23:59:59.000Z

382

THE CHEMICALLY CONTROLLED SYNTHESIS OF DUST IN TYPE II-P SUPERNOVAE  

SciTech Connect (OSTI)

We study the formation of molecules and dust clusters in the ejecta of solar metallicity, Type II-P supernovae (SNe) using a chemical kinetic approach. We follow the evolution of molecules and small dust cluster masses from day 100 to day 1500 after explosion. We consider stellar progenitors with initial masses of 12, 15, 19, and 25 M{sub ?} that explode as SNe with stratified ejecta. The molecular precursors to dust grains comprise molecular chains, rings and small clusters of silica, silicates, metal oxides, sulfides and carbides, pure metals, and carbon, where the nucleation of silicate clusters is described by a two-step process of metal and oxygen addition. We study the impact of the {sup 56}Ni mass on the type and amount of synthesized dust. We predict that large masses of molecules including CO, SiO, SiS, O{sub 2}, and SO form in the ejecta. We show that the discrepancy between the small dust masses detected at infrared wavelengths some 500 days post-explosion and the larger amounts of dust recently detected with Herschel in SN remnants can be explained by the non-equilibrium chemistry linked to the formation of molecules and dust clusters in the ejected material. Dust gradually builds up from small (?10{sup –5} M{sub ?}) to large masses (?5 × 10{sup –2} M{sub ?}) over a 5 yr period after explosion. Subsequent dust formation and/or growth is hampered by the shortage of chemical agents participating in the dust nucleation and the long timescale for accretion. The results highlight the dependence of the dust chemical composition and mass on the amount of {sup 56}Ni synthesized during the explosion. This dependence may partly explain the diversity of epochs at which dust forms in SNe. More generally, our results indicate that Type II-P SNe are efficient but moderate dust producers with an upper limit on the mass of synthesized dust ranging from ?0.03 to 0.09 M{sub ?}. Other dust sources must then operate at high redshift to explain the large quantities of dust present in young galaxies in the early universe.

Sarangi, Arkaprabha; Cherchneff, Isabelle, E-mail: arkaprabha.sarangi@unibas.ch, E-mail: isabelle.cherchneff@unibas.ch [Departement Physik, Universität Basel, CH-4056 Basel (Switzerland)

2013-10-20T23:59:59.000Z

383

E-Print Network 3.0 - asthma dust mite Sample Search Results  

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

cell Summary: -cockroach, anti-mouse, and anti-dust mite IgE levels, wheeze, cough, eczema and asthma. Results: Correlations... , maternal asthma, prenatal cockroach...

384

E-Print Network 3.0 - acute coal dust Sample Search Results  

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

(WTERT) Collection: Renewable Energy 25 Atmospheric Environment 38 (2004) 59916004 The air-borne particulate pollution in Beijing--concentration, Summary: ., 2002). Dust-soil,...

385

E-Print Network 3.0 - acute house dust Sample Search Results  

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

and Human Exposure Summary: rising worldwide (4). PBDEs accumulate in house dust, sewage sludge, biosolids, wildlifepets, and humans... matrices including furniture foam,...

386

E-Print Network 3.0 - alkaline dust impact Sample Search Results  

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

Chem. Phys., 10, 39994012, 2010 www.atmos-chem-phys.net1039992010 Summary: in terms of accumulation of nitrate and sulfate, titration of dust alkalinity, and impact on...

387

Cement kiln flue dust as a source of lime and potassium in four East Texas soils  

E-Print Network [OSTI]

design on both sites. Yield, soil pH, plant and soil concentrations of K, Ca, and Mg were determined. Soil pH and extractable Ca increased with increasing rate of flue dust or calcite. Under field conditions, flue dust compared favorably with calcite... was similar to plant uptake from corresponding calcite + KC1 treatments. Soil pH and extractable soil K, Ca, and Mg increased with increased rate of flue dust treatment equally as well as from the corresponding calcite treatments. The flue dust was equal...

Poole, Warren David

1975-01-01T23:59:59.000Z

388

Clementine Observations of the Zodiacal Light and the Dust Content of the Inner Solar System  

E-Print Network [OSTI]

Using the Moon to occult the Sun, the Clementine spacecraft used its navigation cameras to map the inner zodiacal light at optical wavelengths over elongations of 3-30 degrees from the Sun. This surface brightness map is then used to infer the spatial distribution of interplanetary dust over heliocentric distances of about 10 solar radii to the orbit of Venus. We also apply a simple model that attributes the zodiacal light as being due to three dust populations having distinct inclination distributions, namely, dust from asteroids and Jupiter-family comets (JFCs), dust from Halley-type comets, and an isotropic cloud of dust from Oort Cloud comets. The best-fitting scenario indicates that asteroids + JFCs are the source of about 45% of the optical dust cross-section seen in the ecliptic at 1 AU, but that at least 89% of the dust cross-section enclosed by a 1 AU radius sphere is of a cometary origin. When these results are extrapolated out to the asteroid belt, we find an upper limit on the mass of the light-reflecting asteroidal dust that is equivalent to a 12 km asteroid, and a similar extrapolation of the isotropic dust cloud out to Oort Cloud distances yields a mass equivalent to a 30 km comet, although the latter mass is uncertain by orders of magnitude.

J. M. Hahn; H. A. Zook; B. Cooper; B. Sunkara

2002-04-07T23:59:59.000Z

389

Effects of climate, physical erosion, parent mineralogy, and dust on chemical erosion rates in mountainous terrain  

E-Print Network [OSTI]

Bryan, K. , 1927. The ”Palouse soil” problem. USGS Bulletinin the Channeled Scablands and Palouse of Washington State.dust-producing engine of the Palouse loess, USA. Quaternary

Ferrier, Ken

2009-01-01T23:59:59.000Z

390

E-Print Network 3.0 - american house dust Sample Search Results  

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

7 Evaluation of HVAC filters as a sampling mechanism for indoor microbial communities Summary: , in the dust samples collected in the unoccupied UTest House (mean value...

391

Water in Emission in the ISO Spectrum of the Early M Supergiant Star mu Cephei  

E-Print Network [OSTI]

We report a detection of water in emission in the spectrum of the M2 supergiant atar mu Cep (M2Ia) observed by the Short Wavelength Spectrometer (SWS) aboard Infrared Space Observatory (ISO) and now released as the ISO Archives. The emission first appears in the 6 micron region (nu2 fundamental) and then in the 40 micron region (pure rotation lines) despite the rather strong dust emission. The intensity ratios of the emission features are far from those of the optically thin gaseous emission. Instead, we could reproduce the major observed emission features by an optically thick water sphere of the inner radius about two stellar radii (1300Rsun), Tex = 1500K, and Ncol (H2O) = 3.0E+20/cm2. This model also accounts for the H2O absorption bands in the near infrared (1.4, 1.9, and 2.7 micron) as well. The detection of water in emission provides strong constraints on the nature of water in the early M supergiant stars, and especially its origin in the outer atmosphere is confirmed against other models such as the large convective cell model. We finally confirm that the early M supergiant star is surrounded by a huge optically thick sphere of the warm water vapor, which may be referred to as MOLsphere for simplicity. Thus, the outer atmosphere of M supergiant stars should have a complicated hierarchical and/or hybrid structure with at least three major constituents including the warm MOLsphere (T about 1.0E+3K) together with the previously known hot chromosphere (T about 1.0E+4K) and cool expanding gas-dust envelope (T about 1.0E+2K).

T. Tsuji

2000-08-03T23:59:59.000Z

392

The roles of non-extensivity and dust concentration as bifurcation parameters in dust-ion acoustic traveling waves in magnetized dusty plasma  

SciTech Connect (OSTI)

Dust ion-acoustic traveling waves are studied in a magnetized dusty plasma in presence of static dust and non-extensive distributed electrons in the framework of Zakharov-Kuznesstov-Burgers (ZKB) equation. System of coupled nonlinear ordinary differential equations is derived from ZKB equation, and equilibrium points are obtained. Nonlinear wave phenomena are studied numerically using fourth order Runge-Kutta method. The change from unstable to stable solution and consequently to asymptotic stable of dust ion acoustic traveling waves is studied through dynamical system approach. It is found that some dramatical features emerge when the non-extensive parameter and the dust concentration parameters are varied. Behavior of the solution of the system changes from unstable to stable and stable to asymptotic stable depending on the value of the non-extensive parameter. It is also observed that when the dust concentration is increased the solution pattern is changed from oscillatory shocks to periodic solution. Thus, non-extensive and dust concentration parameters play crucial roles in determining the nature of the stability behavior of the system. Thus, the non-extensive parameter and the dust concentration parameters can be treated as bifurcation parameters.

Narayan Ghosh, Uday; Kumar Mandal, Pankaj, E-mail: pankajwbmsd@gmail.com; Chatterjee, Prasanta [Department of Mathematics, Siksha Bhavana Visva Bharati, Santiniketan, West Bengal 731235 (India)] [Department of Mathematics, Siksha Bhavana Visva Bharati, Santiniketan, West Bengal 731235 (India)

2014-03-15T23:59:59.000Z

393

A classification of spherically symmetric self-similar dust models  

E-Print Network [OSTI]

We classify all spherically symmetric dust solutions of Einstein's equations which are self-similar in the sense that all dimensionless variables depend only upon $z\\equiv r/t$. We show that the equations can be reduced to a special case of the general perfect fluid models with equation of state $p=\\alpha \\mu$. The most general dust solution can be written down explicitly and is described by two parameters. The first one (E) corresponds to the asymptotic energy at large $|z|$, while the second one (D) specifies the value of z at the singularity which characterizes such models. The E=D=0 solution is just the flat Friedmann model. The 1-parameter family of solutions with z>0 and D=0 are inhomogeneous cosmological models which expand from a Big Bang singularity at t=0 and are asymptotically Friedmann at large z; models with E>0 are everywhere underdense relative to Friedmann and expand forever, while those with E0 ones. The 2-parameter solutions with D>0 again represent inhomogeneous cosmological models but the Big Bang singularity is at $z=-1/D$, the Big Crunch singularity is at $z=+1/D$, and any particular solution necessarily spans both z0. While there is no static model in the dust case, all these solutions are asymptotically ``quasi-static'' at large $|z|$. As in the D=0 case, the ones with $E \\ge 0$ expand or contract monotonically but the latter may now contain a naked singularity. The ones with E<0 expand from or recollapse to a second singularity, the latter containing a black hole.

B. J. Carr

2000-03-02T23:59:59.000Z

394

Dust: A major environmental hazard on the earth's moon  

SciTech Connect (OSTI)

On the Earth's Moon, obvious hazards to humans and machines are created by extreme temperature fluctuations, low gravity, and the virtual absence of any atmosphere. The most important other environmental factor is ionizing radiation. Less obvious environmental hazards that must be considered before establishing a manned presence on the lunar surface are the hazards from micrometeoroid bombardment, the nuisance of electro-statically-charged lunar dust, and an alien visual environment without familiar clues. Before man can establish lunar bases and lunar mining operations, and continue the exploration of that planet, we must develop a means of mitigating these hazards. 4 refs.

Heiken, G.; Vaniman, D.; Lehnert, B.

1990-01-01T23:59:59.000Z

395

Simulation of dust streaming in toroidal traps: Stationary flows  

SciTech Connect (OSTI)

Molecular-dynamic simulations were performed to study dust motion in a toroidal trap under the influence of the ion drag force driven by a Hall motion of the ions in E x B direction, gravity, inter-particle forces, and friction with the neutral gas. This article is focused on the inhomogeneous stationary streaming motion. Depending on the strength of friction, the spontaneous formation of a stationary shock or a spatial bifurcation into a fast flow and a slow vortex flow is observed. In the quiescent streaming region, the particle flow features a shell structure which undergoes a structural phase transition along the flow direction.

Reichstein, Torben; Piel, Alexander [IEAP, Christian-Albrechts-Universitaet, D-24098 Kiel (Germany)

2011-08-15T23:59:59.000Z

396

Evaluation and recommendations for reduction of a silica dust exposure  

E-Print Network [OSTI]

to the increase in active tuberculosis among silicotics previously discussed. Perhaps there is a synergistic effect between silicosis and various lung cancers. A 1999 paper by Checkoway("6) showed a significantly (p=0. 02) increasing trend of lung cancer..., and that 100, 000 are exposed to silica dust through sandblasting, rock drilling and mining operations. &sI Silica is the second- most-common mineral in the earth's crust and a major component of sand, rock and mineral ores so it is not surprising to find...

Gruben, Raymond L

2000-01-01T23:59:59.000Z

397

Collapsing Inhomogeneous Dust Fluid in the Background of Dark Energy  

E-Print Network [OSTI]

In the present work, gravitational collapse of an inhomogeneous spherical star model, consisting of inhomogeneous dust fluid (dark matter) in the background of dark energy is considered. The collapsing process is examined first separately for both dark matter and dark energy and then under the combined effect of dark matter and dark energy with or without interaction. The dark energy is considered in the form of perfect fluid and both marginally and non-marginally bound cases are considered for the collapsing model. Finally dark energy in the form of anisotropic fluid is investigated and it is found to be similar to ref. [12

Tanwi Bandyopadhyay; Subenoy Chakraborty

2006-05-11T23:59:59.000Z

398

Volumetric measurements of a spatially growing dust acoustic wave  

SciTech Connect (OSTI)

In this study, tomographic particle image velocimetry (tomo-PIV) techniques are used to make volumetric measurements of the dust acoustic wave (DAW) in a weakly coupled dusty plasma system in an argon, dc glow discharge plasma. These tomo-PIV measurements provide the first instantaneous volumetric measurement of a naturally occurring propagating DAW. These measurements reveal over the measured volume that the measured wave mode propagates in all three spatial dimensional and exhibits the same spatial growth rate and wavelength in each spatial direction.

Williams, Jeremiah D. [Physics Department, Wittenberg University, Springfield, Ohio 45504 (United States)

2012-11-15T23:59:59.000Z

399

Dust takes detour on ice-cloud journey | EMSL  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to UserProduct:Directives Templates8.Sifting Slush:NewDust takes detour on

400

Space Dust Analysis Could Provide Clues to Solar System Origins  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administrationcontroller systemsBiSite CulturalDepartment2)isomeraseUSCharge CompensationSpace Dust

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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

Space Dust Analysis Could Provide Clues to Solar System Origins  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmittedStatus Tom Fletcher,Future |Carlos ValenciaSpace Dust Analysis Could

402

Space Dust Analysis Could Provide Clues to Solar System Origins  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmittedStatus Tom Fletcher,Future |Carlos ValenciaSpace Dust Analysis

403

Space Dust Analysis Could Provide Clues to Solar System Origins  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmittedStatus Tom Fletcher,Future |Carlos ValenciaSpace Dust AnalysisSpace

404

INJECTION OF SUPERNOVA DUST IN NEARBY PROTOPLANETARY DISKS  

SciTech Connect (OSTI)

The early solar system contained a number of short-lived radionuclides (SLRs) such as {sup 26}Al with half-lives <15 Myr. The one-time presence of {sup 60}Fe strongly suggests that the source of these radionuclides was a nearby supernova. In this paper, we investigate the 'aerogel' model, which hypothesizes that the solar system's SLRs were injected directly into the solar system's protoplanetary disk from a supernova within the same star-forming region. Previous work has shown that disks generally survive the impact of supernova ejecta, but also that little gaseous ejecta can be injected into the disk. The aerogel model hypothesizes that radionuclides in the ejecta condensed into micron-sized dust grains that were injected directly into the solar nebula disk. Here, we discuss the density structure of supernova ejecta and the observational support for dust condensation in the ejecta. We argue that supernova ejecta are clumpy and describe a model to quantify this clumpiness. We also argue that infrared observations may be underestimating the fraction of material that condenses into dust. Building on calculations of how supernova ejecta interact with protoplanetary disks, we calculate the efficiency with which dust grains in the ejecta are injected into a disk. We find that about 70% of material in grains roughly 0.4 {mu}m in diameter can be injected into disks. If ejecta are clumpy, the solar nebula was struck by a clump with higher-than-average {sup 26}Al and {sup 60}Fe, and these elements condensed efficiently into large grains, then the abundances of SLRs in the early solar system can be explained, even if the disk lies 2 pc from the supernova explosion. The probability that all these factors are met is low, perhaps {approx}10{sup -3}-10{sup -2}, and receiving as much {sup 26}Al and {sup 60}Fe as the solar system did may be a rare event. Still, the aerogel model remains a viable explanation for the origins of the radionuclides in the early solar system, and may be the most plausible one.

Ouellette, N. [Department of Physics, Arizona State University, P.O. Box 871504, Tempe, AZ 85287-1504 (United States); Desch, S. J.; Hester, J. J. [School of Earth and Space Exploration, Arizona State University, P.O. Box 871404, Tempe, AZ 85287-1404 (United States)

2010-03-10T23:59:59.000Z

405

Survey of cometary CO2, CO, and particulate emissions using the Spitzer Space Telescope: Smog check for comets  

E-Print Network [OSTI]

We surveyed 23 comets using the Infrared Array Camera on the Spitzer Space Telescope in wide filters centered at 3.6 and 4.5 microns. Emission in the 3.6 micron filter arises from sunlight scattered by dust grains; these images generally have a coma near the nucleus and a tail in the antisolar direction due to dust grains swept back by solar radiation pressure. The 4.5 micron filter contains the same dust grains, as well as strong emission lines from CO2 and CO gas; these show distinct morphologies, in which cases we infer they are dominated by gas. Based on the ratio of 4.5 to 3.6 micron brightness, we classify the survey comets as CO2+CO "rich" and "poor." This classification is correlated with previous classifications by A'Hearn based on carbon-chain molecule abundance, in the sense that comets classified as "depleted" in carbon-chain molecules are also "poor" in CO2+CO. The gas emission in the IRAC 4.5 micron images is characterized by a smooth morphology, typically a fan in the sunward hemisphere with a ...

Reach, William T; Vaubaillon, Jeremie

2013-01-01T23:59:59.000Z

406

Optimal irreversible stimulated emission  

E-Print Network [OSTI]

We studied the dynamics of an initially inverted atom in a semi-infinite waveguide, in the presence of a single propagating photon. We show that atomic relaxation is enhanced by a factor of 2, leading to maximal bunching in the output field. This optimal irreversible stimulated emission is a novel phenomenon that can be observed with state-of-the-art solid-state atoms and waveguides. When the atom interacts with two one-dimensional electromagnetic environments, the preferential emission in the stimulated field can be exploited to efficiently amplify a classical or a quantum state.

D Valente; Y Li; J P Poizat; J M Gerard; L C Kwek; M F Santos; A Auffeves

2012-08-28T23:59:59.000Z

407

Controlled spontaneous emission  

E-Print Network [OSTI]

The problem of spontaneous emission is studied by a direct computer simulation of the dynamics of a combined system: atom + radiation field. The parameters of the discrete finite model, including up to 20k field oscillators, have been optimized by a comparison with the exact solution for the case when the oscillators have equidistant frequencies and equal coupling constants. Simulation of the effect of multi-pulse sequence of phase kicks and emission by a pair of atoms shows that both the frequency and the linewidth of the emitted spectrum could be controlled.

Jae-Seung Lee; Mary A. Rohrdanz; A. K. Khitrin

2007-07-03T23:59:59.000Z

408

Acceptable approaches for beneficial use of cement kiln dust  

SciTech Connect (OSTI)

One beneficial use of cement kiln dust (CKD) is application of CKD to cropland as agricultural lime or fertilizer. However, the EPA has expressed a concern over land application of CKD when the metals constituents in the CKD are above the industry-wide median levels presented in EPA`s Report to Congress on Cement Kiln Dust. Under the Clean Water Act, EPA has established limits for metals concentrations in sewage sludge that is applied to the land for beneficial use of the nitrogen in the sludge. The limits for land application of sewage sludge were established based on the results of exposure risk assessments. A comparison of the median industry-wide metals concentrations in CKD to the metals concentration limits for land application of sewage sludge indicates that all trace metal concentrations IN CKD are below the corresponding sewage sludge land application limit, with the exception of the median level of arsenic from one data set. EPA has determined that land application of CKD with metals concentration limits at or below the industry-wide median concentrations does not pose a significant human cancer or non-cancer health risk. Therefore, with appropriate limits, CKD can be beneficially reused for land application on agricultural land in a manner that is protective of human health and the environment.

Schreiber, R.J.; Smeenk, S.D. [Schreiber, Yonley and Associates, St. Louis, MO (United States)

1998-12-31T23:59:59.000Z

409

Direct Observation of Completely Processed Calcium Carbonate Dust Particles  

SciTech Connect (OSTI)

This study presents, for the first time, field evidence of complete, irreversible processing of solid calcium carbonate (calcite)-containing particles and quantitative formation of liquid calcium nitrate particles apparently as a result of heterogeneous reaction of calcium carbonate-containing mineral dust particles with gaseous nitric acid. Formation of nitrates from individual calcite and sea salt particles was followed as a function of time in aerosol samples collected at Shoresh, Israel. Morphology and compositional changes of individual particles were observed using conventional scanning electron microscopy with energy dispersive analysis of X-rays (SEM/EDX) and computer controlled SEM/EDX. Environmental scanning electron microscopy (ESEM) was utilized to determine and demonstrate the hygroscopic behavior of calcium nitrate particles found in some of the samples. Calcium nitrate particles are exceptionally hygroscopic and deliquesce even at very low relative humidity (RH) of 9 -11% which is lower than typical atmospheric environments. Transformation of non-hygroscopic dry mineral dust particles into hygroscopic wet aerosol may have substantial impacts on light scattering properties, the ability to modify clouds and heterogeneous chemistry.

Laskin, Alexander; Iedema, Martin J.; Ichkovich, Aviad; Graber, Ellen R.; Taraniuk, Ilya; Rudich, Yinon

2005-05-27T23:59:59.000Z

410

Coulomb interactions between dust particles in plasma etching reactors  

SciTech Connect (OSTI)

Wafer contamination by particles, or dust, in plasma processing reactors remains a continuing concern in the microelectronics industry. Particles charge negatively in low temperature plasmas and resemble electrically floating bodies. The transport of these particles in plasma processing reactors is dominated by electrostatic, ion-drag, fluid-drag, and thermophoretic forces. Under conditions where the particle density is large, Debye shielding may be insufficient to isolate the particles, leading to particle-particle Coulomb interactions. Such interactions are likely to occur in trapping locations, which are typically near the plasma-sheath boundaries in Reactive Ion Etching (RIE) discharges. Particles that experience Coulomb interactions may display collective behavior, an extreme example being a Coulomb liquid or solid. Particle transport in plasma processing reactors has been studied extensively to predict rates of wafer contamination thought to date particle-particle interactions have not been addressed. In this paper, the authors discuss results from a computer model for dust particle transport in RIE discharges where particle-particle Coulomb interactions are included.

Hwang, H.H.; Kushner, M.J. [Univ. of Illinois, Urbana, IL (United States). Dept. of Electrical and Computer Engineering

1996-12-31T23:59:59.000Z

411

Direct climate effect of black carbon in China and its impact on dust storms  

E-Print Network [OSTI]

.shtml, 22 March 2002). [3] Observations indicate that the total days of dust storm occurrence per yearClick Here for Full Article Direct climate effect of black carbon in China and its impact on dust and the surrounding areas critically impact weather, climate, and public health in China and neighboring Pacific Rim

Liou, K. N.

412

Raman spectroscopy of carbon dust samples from NSTX Y. Raitses a,*, C.H. Skinner a  

E-Print Network [OSTI]

for the diagnosis of the microscopic structure of different forms of carbon. The intensity of D-mode at 1350 cmÃ?1Raman spectroscopy of carbon dust samples from NSTX Y. Raitses a,*, C.H. Skinner a , F. Jiang b , T. The Raman measurements indicate that the production of carbon dust particles in NSTX involves modifications

Duffy, Thomas S.

413

Dust Filtration by Planet-Induced Gap Edges: Implications for Transitional Disks  

E-Print Network [OSTI]

By carrying out two-dimensional two-fluid global simulations, we have studied the response of dust to gap formation by a single planet in the gaseous component of a protoplanetary disk - the so-called "dust filtration" mechanism. We have found that a gap opened by a giant planet at 20 AU in a \\alpha=0.01, \\dot{M}=10^{-8} Msun/yr disk can effectively stop dust particles larger than 0.1 mm drifting inwards, leaving a sub-millimeter dust cavity/hole. However, smaller particles are difficult to filter by a planet-induced gap due to 1) dust diffusion, and 2) a high gas accretion velocity at the gap edge. An analytic model is also derived to understand what size particles can be filtered by the gap edge. Finally, with our updated understanding of dust filtration, we have computed Monte-Carlo radiative transfer models with variable dust size distributions to generate the spectral energy distributions (SEDs) of disks with gaps. By comparing with transitional disk observations (e.g. GM Aur), we have found that dust fi...

Zhu, Zhaohuan; Dong, Ruobing; Espaillat, Catherine; Hartmann, Lee

2012-01-01T23:59:59.000Z

414

Tritium Behavior in Eroded Dust and Debris of Plasma-Facing Materials*  

E-Print Network [OSTI]

. & ,. 1. . . . Tritium Behavior in Eroded Dust and Debris of Plasma-Facing Materials* RECQVED SEP2 Reactor Materials (ICFRM-8) October 26-31, 1997, Sendai, Japan. qWork supported by the U.S. Department;. . . . . Tritium Behavior in Eroded Dust and Debris of Plasma-Facing Materials A. Hassanein', B. Wiechers2, and I

Harilal, S. S.

415

Simulated Global Atmospheric Dust Distribution: Sensitivity to Regional Topography, Geomorphology, and Hydrology  

E-Print Network [OSTI]

, and Hydrology Charles S. Zender, Earth System Science Dept., UC Irvine, Irvine, CA 92697 (zender@uci.edu) David for predicting future trends in dust production. We identify three related geomorphologic and hydrologic hydrologically disturbed/renewed sed- iments. Dust models which attempt to account for sediment-rich source

Zender, Charles

416

Manure Harvesting Frequency: The Key to Feedyard Dust Control in a Summer Drought  

E-Print Network [OSTI]

Summer drought can make dust control in feedyards more challenging than usual. Supplemental water may not keep pace with daily evaporation. The key to dust control is managing the depth of dry manure in the pens by harvesting manure more frequently...

Auvermann, Brent W.; Parker, David B.; Sweeten, John M.

2000-11-27T23:59:59.000Z

417

DUST TEMPERATURES IN THE INFRARED SPACE OBSERVATORY ATLAS OF BRIGHT SPIRAL GALAXIES1  

E-Print Network [OSTI]

DUST TEMPERATURES IN THE INFRARED SPACE OBSERVATORY ATLAS OF BRIGHT SPIRAL GALAXIES1 George J Space Observatory Atlas of Bright Spiral Galaxies. For the 71 galaxies where we had complete 60­180 lm Facility (IRTF) with IRAS far-infrared data to conclude that spiral galaxies have cold dust components

Joseph, Robert D.

418

Constraining Oceanic dust deposition using surface 1 ocean dissolved Al 2  

E-Print Network [OSTI]

Constraining Oceanic dust deposition using surface 1 ocean dissolved Al 2 Qin Han, J. Keith Moore, Charles Zender, Chris Measures, David Hydes 3 Abstract 4 We use measurements of ocean surface dissolved Al and Deposition 6 (DEAD) model, to constrain dust deposition to the oceans. Our Al database contains 7 all

Zender, Charles

419

Dark energy and dust matter phases from an exact $f(R)$-cosmology model  

E-Print Network [OSTI]

We show that dust matter-dark energy combined phases can be achieved by the exact solution derived from a power law $f(R)$ cosmological model. This example answers the query by which a dust-dominated decelerated phase, before dark-energy accelerated phase, is needed in order to form large scale structures.

S. Capozziello; P. Martin-Moruno; C. Rubano

2008-04-28T23:59:59.000Z

420

Statistical Method for the Determination of the Ignition Energy of Dust Cloud-Experimental Validation  

E-Print Network [OSTI]

of preventive safeguard to control the plants safety. The mitigation of an explosion hazard, according, using the Langlie test, for the quick determination of the explosion sensitivity of dusts. This methodStatistical Method for the Determination of the Ignition Energy of Dust Cloud- Experimental

Paris-Sud XI, Université de

Note: This page contains sample records for the topic "fugitive dust emissions" 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

Tritium Containment in the Dust and Debris of Plasma-Facing Materials Produced During Operations  

E-Print Network [OSTI]

' . . , . Tritium Containment in the Dust and Debris of Plasma-Facing Materials Produced During avaihble original document. #12;Tritium Containment in the Dust and Debris of Plasma-Facing hlaterials. IL 60439, USA Tritium behavior in plasma-facing components of future tokamak reactors such as ITER

Harilal, S. S.

422

New ice core evidence for a volcanic cause of the A.D. 536 dust veil  

E-Print Network [OSTI]

New ice core evidence for a volcanic cause of the A.D. 536 dust veil L. B. Larsen,1 B. M. Vinther,1. [1] New and well-dated evidence of sulphate deposits in Greenland and Antarctic ice cores indicate a substantial and extensive atmospheric acidic dust veil at A.D. 533­534 ± 2 years. This was likely produced

Nicolussi, Kurt

423

MEMS `SMART DUST MOTES' FOR DESIGNING, MONITORING AND ENABLING EFFICIENT LIGHTING  

E-Print Network [OSTI]

-based lighting system has the potential to achieve many environmental benefits in comparison to existing sensorMEMS `SMART DUST MOTES' FOR DESIGNING, MONITORING AND ENABLING EFFICIENT LIGHTING Alice M. Agogino focused on office lighting monitoring and control based on the new MEMS `smart dust mote' sensor

Agogino, Alice M.

424

Analysis of the effects of a proposed rule for the enforcement of respirable dust standards  

E-Print Network [OSTI]

The effects of a rule for the enforcement of respirable dust standards proposed by the Mine Safety and Health Administration (MSHA) has been evaluated. Respirable coal dust sample data collected over a three year period by a mining company were used...

Britton, Robert Grant

1996-01-01T23:59:59.000Z

425

Cancer Mortality and Wood Dust Exposure Among Participants in the American Cancer  

E-Print Network [OSTI]

Cancer Mortality and Wood Dust Exposure Among Participants in the American Cancer Society Cancer and Paolo Boffetta, MD, MPH3 In 1994, the International Agency for Research on Cancer (IARC) classified wood dust as a human carcinogen, based on very strong evidence of a carcinogenic risk of sino-nasal cancer

Salzman, Daniel

426

Study on plasma parameters and dust charging in an electrostatically plugged multicusp plasma device  

SciTech Connect (OSTI)

The effect of the electrostatic confinement potential on the charging of dust grains and its relationship with the plasma parameters has been studied in an electrostatically plugged multicusp dusty plasma device. Electrostatic plugging is implemented by biasing the electrically isolated magnetic multicusp channel walls. The experimental results show that voltage applied to the channel walls can be a controlling parameter for dust charging.

Kakati, B.; Kausik, S. S.; Saikia, B. K. [Centre of Plasma Physics, Institute for Plasma Research, Nazirakhat, Sonapur-782 402, Kamrup, Assam (India); Bandyopadhyay, M. [ITER-India, Institute for Plasma Research, Bhat, Gandhinagar- 382 428 (India)

2011-06-15T23:59:59.000Z

427

THE CHEMICAL IMPRINT OF SILICATE DUST ON THE MOST METAL-POOR STARS  

E-Print Network [OSTI]

We investigate the impact of dust-induced gas fragmentation on the formation of the first low-mass, metal-poor stars (<1 M[subscript ?]) in the early universe. Previous work has shown the existence of a critical dust-to-gas ...

Bromm, Volker

428

Mineralogy of Martian atmospheric dust inferred from thermal infrared spectra of aerosols  

E-Print Network [OSTI]

Mineralogy of Martian atmospheric dust inferred from thermal infrared spectra of aerosols Victoria deconvolution algorithm to the spectra to model the dust mineralogy. Models of the M9 IRIS transmission data generally are of poor quality, and the mineralogical results of these fits are unlikely to be valid. Fits

Hamilton, Victoria E.

429

Effect of Electric Arc Furnace Bag House Dust on Concrete Durability Researcher: Fahad Al-Mutlaq  

E-Print Network [OSTI]

Effect of Electric Arc Furnace Bag House Dust on Concrete Durability Researcher: Fahad Al billions of dollars annually. While steel is normally protected from corrosion in concrete by a passive of the effects of addition of Bag House Dust (BHD) on aspects of concrete durability. BHD is a fine powder

Birmingham, University of

430

Generation of concentration density maxima of small dispersive coal dust particles in horizontal iodine air filter at air-dust aerosol blow  

E-Print Network [OSTI]

The spatial distributions of the small dispersive coal dust particles with the nano and micro sizes in the granular filtering medium with the cylindrical coal granules in the absorber in the horizontal iodine air filter during its long term operation at the nuclear power plant are researched. It is shown that the concentration density maxima of the small dispersive coal dust particles appear in the granular filtering medium with the cylindrical coal absorbent granules in the horizontal iodine air filter at an action by the air dust aerosol blow. The comparison of the measured aerodynamic resistances of the horizontal and vertical iodine air filters is conducted. The main conclusion is that the magnitude of the aerodynamic resistance of the horizontal iodine air filters is much smaller in comparison with the magnitude of the aerodynamic resistance of the vertical iodine air filters at the same loads of the air dust aerosol volumes. It is explained that the direction of the air dust aerosol blow and the direction of the gravitation force in the horizontal iodine air filter are orthogonal, hence the effective accumulation of the small dispersive coal dust particles takes place at the bottom of absorber in the horizontal iodine air filter. It is found that the air dust aerosol stream flow in the horizontal iodine air filter is not limited by the appearing structures, made of the precipitated small dispersive coal dust particles, in distinction from the vertical iodine air filter, in the process of long term operation of the iodine air filters at the nuclear power plant.

I. M. Neklyudov; O. P. Ledenyov; L. I. Fedorova; P. Ya. Poltinin

2013-06-11T23:59:59.000Z

431

Ice emission and the redshifts of submillimeter sources  

E-Print Network [OSTI]

Observations at submillimeter wavelengths have revealed a population of sources thought to be at relatively large redshifts. The position of the 850 $\\mu$m passband on the Rayleigh-Jeans portion of the Planck function leads to a maximum redshift estimate of $z\\sim$4.5 since sources will not retain their redshift independent brightness close to the peak of the Planck function and thus drop out of surveys. Here we review evidence that ice absorption is present in the spectra of local ultraluminous infrared galaxies which are often taken as analogs for the 850 $\\mu$m source population. We consider the implication of this absorption for ice induced spectral structure at far infrared wavelengths and present marginal astronomical evidence that amorphous ice may have a feature similar to crystalline ice near 150 $\\mu$m. Recent corroborative laboratory evidence is supportive of this conclusion. It is argued that early metal enrichment by pair instability SN may lead to a high ice content relative to refractory dust at high redshift and a fairly robust detection of ice emission in a $z=6.42$ quasar is presented. It is further shown that ice emission is needed to understand the 450 $\\mu$m sources observed in the GOODS-N field. We are thus encouraged to apply far infrared ice emission models to the available observations of HDF 850.1, the brightest submillimeter source in the {\\it Hubble Deep Field}. We suggest that a redshift as large as 13 may need to be considered for this source, nearly a factor of three above the usual top estimate. Inclusion of the possibility of far infrared ice emission in the spectral energy distributions of model sources generally broadens the range of redshifts to be considered for submillimeter sources compared to models without ice emission.

C. C. Dudley; M. Imanishi; P. R. Maloney

2008-02-12T23:59:59.000Z

432

Secondary emission gas chamber  

E-Print Network [OSTI]

For a hadron calorimeter active element there is considered a gaseous secondary emis-sion detector (150 micron gap, 50 kV/cm). Such one-stage parallel plate chamber must be a radiation hard, fast and simple. A model of such detector has been produced, tested and some characteristics are presented.

V. In'shakov; V. Kryshkin; V. Skvortsov

2014-12-10T23:59:59.000Z

433

CARBON DIOXIDE EMISSION REDUCTION  

E-Print Network [OSTI]

.5 Primary Energy Use and Carbon Dioxide Emissions for Selected US Chemical Subsectors in 1994 ...............................................................................................................16 Table 2.7 1999 Energy Consumption and Specific Energy Consumption (SEC) in the U.S. Cement Efficiency Technologies and Measures in Cement Industry.................22 Table 2.9 Energy Consumption

Delaware, University of

434

Graphene Coating Coupled Emission  

E-Print Network [OSTI]

Graphene Coating Coupled Emission A COMSET, A single sheet of sp2-hybridized carbon atoms, called of graphene and its unique properties, I will present amplification of surface graphene-Ag hybrid films which when graphene is used as the spacer layer in a conventional Ag- harnessed the nonlinear properties

Shyamasundar, R.K.

435

anomalous silicate dust: Topics by E-print Network  

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

emission feature in the type 1 (i.e. face-on) LINER nucleus of M81. Using the Infrared Spectrograph (IRS) instrument on Spitzer, we determine the feature in the central 230...

436

Roles of polarization force and nonthermal electron on dust-acoustic waves in an inhomogeneous dusty plasma with positively charged dust  

SciTech Connect (OSTI)

The influence of polarization force (PF) (arises due to dust density inhomogeneity), nonthermal electrons, and dust density inhomogeneity associated with positively charged dust on linear dust-acoustic (DA) waves in an inhomogeneous unmagnetized dusty plasma are investigated. By taking the normal mode analysis, the dispersion relation in such a non-Maxwellian inhomogeneous plasma is obtained, and that the dispersion properties of the DA waves are significantly modified by the presence of PF and nonthermal electrons. The PF is increased with the increase of nonthermal electrons. It is found that the phase speed of the DA waves is significantly decreased with the presence of PF and nonthermal electrons. The potential associated with the DA waves is de-enhanced with the increase of equilibrium dust number density. The role of positive dust number density on dispersion properties is also shown. The present findings relevant to different scenarios in laboratory and space dusty plasma, such as Martian ionosphere, solar flares, TEXTOR-94 tokamak plasmas, rf excited argon magnetoplasma, etc., can be useful to understand the properties of localized electrostatic disturbances in those dusty plasma system, are also briefly addressed.

Asaduzzaman, M.; Mamun, A. A. [Department of Physics, Jahangirnagar University, Savar, Dhaka 1342 (Bangladesh)

2012-09-15T23:59:59.000Z

437

On the Evolution of Dust Mineralogy, From Protoplanetary Disks to Planetary Systems  

E-Print Network [OSTI]

Mineralogical studies of silicate features emitted by dust grains in protoplanetary disks and Solar System bodies can shed light on the progress of planet formation. The significant fraction of crystalline material in comets, chondritic meteorites and interplanetary dust particles indicates a modification of the almost completely amorphous ISM dust from which they formed. The production of crystalline silicates thus must happen in protoplanetary disks, where dust evolves to build planets and planetesimals. Different scenarios have been proposed, but it is still unclear how and when this happens. This paper presents dust grain mineralogy of a complete sample of protoplanetary disks in the young Serpens cluster. These results are compared to those in the young Taurus region and to sources that have retained their protoplanetary disks in the older Upper Scorpius and Eta Chamaeleontis stellar clusters, using the same analysis technique for all samples. This comparison allows an investigation of the grain mineralo...

Oliveira, Isa; Pontoppidan, Klaus M; van Dishoeck, Ewine F; Augereau, Jean-Charles; Merin, Bruno

2011-01-01T23:59:59.000Z

438

Desert dust and anthropogenic aerosol interactions in the Community Climate System Model coupled-carbon-climate model  

E-Print Network [OSTI]

the atmosphere radiation and the ocean biogeochemistry asradiation. When the desert dust is deposited to the oceans,

2011-01-01T23:59:59.000Z

439

APS/123-QED Influence of the ambipolar-to-free diffusion transition on dust particle charge in a  

E-Print Network [OSTI]

and the thermophoretic force [10, 11]. Dust particle charge is a key parameter in a complex plasma. It determines

Paris-Sud XI, Université de

440

Nonlinear dust acoustic waves in inhomogeneous four-component dusty plasma with opposite charge polarity dust grains  

SciTech Connect (OSTI)

The reductive perturbation technique is employed to investigate the propagation properties of nonlinear dust acoustic (DA) waves in a four-component inhomogeneous dusty plasma (4CIDP). The 4CIDP consists of both positive- and negative-charge dust grains, characterized by different mass, temperature, and density, in addition to a background of Maxwellian electrons and ions. The inhomogeneity caused by nonuniform equilibrium values of particle densities, fluid velocities, and electrostatic potential leads to a significant modification to the nature of nonlinear DA solitary waves. It is found that this model reveals two DA wave velocities, one slow, ?{sub s}, and the other is fast, ?{sub f}. The nonlinear wave evolution is governed by a modified Kortweg-de Vries equation, whose coefficients are space dependent. Both the two soliton types; compressive and rarefactive are allowed corresponding to ?{sub s}. However, only compressive soliton is created corresponding to ?{sub f}. The numerical investigations illustrate the dependence of the soliton amplitude, width, and velocity on the plasma inhomogeneities in each case. The relevance of these theoretical results with 4CIDPs observed in a multi-component plasma configurations in the polar mesosphere is discussed.

El-Taibany, W. F. [Department of Physics, Faculty of Science, Damietta University, New Damietta P. O. 34517 (Egypt)] [Department of Physics, Faculty of Science, Damietta University, New Damietta P. O. 34517 (Egypt)

2013-09-15T23:59:59.000Z

Note: This page contains sample records for the topic "fugitive dust emissions" 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

Superfund Record of Decision (EPA Region 8): Anaconda Smelter Site, Mill Creek, Montana (first remedial action), October 1988  

SciTech Connect (OSTI)

The 160-acre community of Mill Creek is located in Deerlodge County, Montana, immediately adjacent to the Anaconda Smelter NPL site. The community of Mill Creek has been contaminated for over 100 years with smelter emissions, fugitive emissions of flu dust at the smelter, and continued fugitive emissions emanating from adjacent highly contaminated soils. Settled flue emissions in the community of Mill Creek, from the now-defunct copper-smelting operation, contain arsenic, cadmium, and lead. Environmental siting of the community and biological testing of pre-school children, led EPA to conclude that contamination in the Mill Creek area poses an imminent and substantial endangerment to the health of individuals residing there. The primary contaminant of concern at this site is arsenic. Cadmium and lead are secondary contaminants of concern. The selected remedial action for the site includes: permanent relocation of all residents (8 homes) with temporary erosional stabilization of disturbed areas by establishing and maintaining a vegetative cover; demolition, consolidation, and storage.

Not Available

1988-10-02T23:59:59.000Z

442

Published in Powder Technology, 2005, 157, 1-3, 2-11. DUST FORMATION IN ELECTRIC ARC FURNACE  

E-Print Network [OSTI]

of electric arc furnace (EAF) dust shows that bubble burst at the liquid steel surface is the principal source the bubble size would therefore represent an effective solution for reducing drastically the EAF dust such as zinc, lead or cadmium which require EAF dust to be stored in specific landfills. In order to propose

Paris-Sud XI, Université de

443

Dust density effect on complex plasma decay L. Couedel a,b, A.A. Samarian a  

E-Print Network [OSTI]

and supported by comparison to existing experimental data. Key words: Complex plasma, dust, afterglow, decay (PECVD, etching, fusion reactor,etc). The dust particles are charged due to their interactions, the dust particles can be either grown directly in the plasma chamber (by sputtering [6,7] or using

Paris-Sud XI, Université de

444

Allocation of emission rights Economic incentives for emission  

E-Print Network [OSTI]

for all countries High cost effectiviness:High cost effectiviness: International Emission trading Fairness NAM Department of Physical Resource Theory #12;F