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1

Fugitive Emissions in 2010 Site Sustainability Plans  

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

Fugitive Emissions in 2010 Site Sustainability Plans Josh Silverman Chair, Fugitive Emissions Working Group Office of Environmental Policy and Assistance (HS-22) April 14, 2011 2...

2

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

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

5 - Fugitive Dust (Rhode 5 - Fugitive Dust (Rhode Island) Air Pollution Control Regulations: No. 5 - Fugitive Dust (Rhode Island) < Back Eligibility Agricultural Commercial Construction Fed. Government Fuel Distributor General Public/Consumer Industrial Installer/Contractor Institutional Investor-Owned Utility Local Government Low-Income Residential Multi-Family Residential Municipal/Public Utility Nonprofit Residential Retail Supplier Rural Electric Cooperative Schools State/Provincial Govt Systems Integrator Transportation Tribal Government Utility Savings Category Alternative Fuel Vehicles Hydrogen & Fuel Cells Buying & Making Electricity Water Home Weatherization Wind Program Info State Rhode Island Program Type Environmental Regulations Provider Department of Environmental Management These regulations aim to prevent the release of fugitive dust by forbidding

3

NETL: Fugitive Gas Emissions Detection Facilities  

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

Fugitive Gas Emissions Detection Facilities Fugitive Gas Emissions Detection Facilities NETL uses an array of innovative laboratory techniques and field methods to detect and monitor fugitive emissions of CO2 stored in geologic formations. By providing an accurate accounting of stored CO2 and a high level of confidence that the CO2 will permanently remain in storage, these efforts can help ensure the technical soundness and economic viability of carbon sequestration, a technology that is critical to meeting the national goal of reduced greenhouse gas emissions. Successful research to establish the stability and integrity of host formations will help developers of sequestration projects secure permits and emissions reduction credits, while preventing damage to ecosystems and ensuring public health and safety.

4

Notes from September 13, 2012, DOE Fugitive Emissions Working...  

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

emissions. The Chair encouraged FEWG members to work with their respective Site Sustainability Plan (SSP) authors to ensure that the fugitive emissions cuts and plans continue...

5

Controlling Fugitive Emissions to Achieve GHG Reduction Goals  

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

Josh Silverman Chair, DOE Fugitive Emissions Working Group Director, Office of Sustainability Support Office of Health, Safety, and Security Presented at ISM Workshop September...

6

Notes from the October 14, 2010 DOE Fugitive Emissions Working...  

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

(SPO) then presented on the Role of Fugitive Emissions and FEWG in DOE Strategic Sustainability Performance Plan: * The Sustainability Performance Office (SPO) will be staffed...

7

Fugitive Emissions at the Department of Energy: An Overview  

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

2 GHG inventory - Fugitive emissions reduction is highlighted in DOE's Strategic Sustainability Performance Plan (SSPP) as a key strategy for achieving DOE GHG reduction goals *...

8

Engineering analysis of fugitive particulate matter emissions from cattle feedyards  

E-Print Network (OSTI)

An engineering analysis of the fugitive particulate matter emissions from a feedyard is not simple. The presence of an evening dust peak in concentration measurements downwind of a feedyard complicates the calculation of an average 24-h emission flux for the feedyard. The evening dust peak is a recurring event that occurs during evening hours when particulate matter concentration measurements increase and decrease dramatically during a short period of time. The concentrations measured during the evening can be up to 8 times the concentrations measured throughout the rest of the day. There is a perception that these concentration increases are due to increases in cattle activity as the temperature decreases during the evening. The purpose of Objective 1 of this research was to quantify the changes in concentrations based on changes in meteorological conditions and/or cattle activity. Using ISCST3, a Gaussian-based EPAapproved dispersion model used to predict concentrations downwind of the feedyard , the results of this work indicate that up to 80% of the increase in concentrations can be attributed to changes in meteorological conditions (wind speed, stability class, and mixing height.)The total fugitive particulate matter emissions on a cattle feedyard are due to two sources: unpaved roads (vehicle traffic) and pen surfaces (cattle activity). Objective 2 of this research was to quantify the mass fraction of the concentration measurements that was due to unpaved road emissions (vehicle traffic). A recent finding by Wanjura et al. (2004) reported that as much as 80% of the concentrations measured after a rain event were due to unpaved road emissions. An engineering analysis of the potential of the unpaved road emissions versus the total feedyard emissions using ISCST3 suggests that it is possible for 70 to 80% of the concentration measurements to be attributed to unpaved road emissions. The purpose of Objective 3 was to demonstrate the science used by ISCST3 to predict concentrations downwind of an area source. Results from this study indicate that the ISCST3 model utilizes a form of the Gaussian line source algorithm to predict concentrations downwind of an area source.

Hamm, Lee Bradford

2005-12-01T23:59:59.000Z

9

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

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Capturing Fugitives to Reduce DOE's GHG Emissions Capturing Fugitives to Reduce DOE's GHG Emissions Capturing Fugitives to Reduce DOE's GHG Emissions November 15, 2011 - 2:04pm Addthis An electrician foreman for the Western Area Power Administration checks a circuit breaker at the Ault Substation in eastern Colorado. The circuit breaker, containing 85 lbs of SF6, protects equipment in the substation against damage from excessive electrical currents | Courtesy of Western Area Power Administration. An electrician foreman for the Western Area Power Administration checks a circuit breaker at the Ault Substation in eastern Colorado. The circuit breaker, containing 85 lbs of SF6, protects equipment in the substation against damage from excessive electrical currents | Courtesy of Western Area Power Administration.

10

Diffuse and fugitive emission dose assessment on the Hanford Site  

Science Conference Proceedings (OSTI)

On February 3, 1993, the US Department of Energy, Richland Operations Office (RL), received a Compliance Order and Information Request from the Director of the Air and Toxics Division of the US Environmental Protection Agency (EPA), Region 10. The Compliance Order requires RL to (1) evaluate all radionuclide emission points at the Hanford Site to determine which are subject to continuous emission measurement requirements in 40 Code of Federal Regulations (CFR) 61, Subpart H, and (2) continuously measure radionuclide emissions in accordance with 40 CFR 61.93. The Information Request requires RL to provide a written Compliance Plan to meet the requirements of the Compliance Order. The RL Compliance Plan included as one of its milestones the requirement to develop a Federal Facility Compliance Agreement (FFCA). An FFCA was negotiated between RL and the EPA, Region 10, and was entered into on February 7, 1994. One of the milestones was to provide EPA, Region 10, with a copy of the Federal Clean Air Act Title V operating air permit application and Air Emission Inventory (AEI) concurrent with its submission to the Washington State Department of Ecology. The AEI will include an assessment of the diffuse and fugitive emissions from the Hanford Site. This assessment does not identify any diffuse or fugitive emission source that would cause an effective dose equivalent greater than 0.1 mrem/yr.

Davis, W.E.; Schmidt, J.W.; Gleckler, B.P. [Westinghouse Hanford Co., Richland, WA (United States); Rhoads, K. [Pacific Northwest Lab., Richland, WA (United States)

1995-01-01T23:59:59.000Z

11

Fugitive Particulate Emissions from Fly Ash Disposal and Unpaved Roads at a Coal-Fired Power Plant  

Science Conference Proceedings (OSTI)

Standardized estimates of fugitive emissions resulting from bulk materials handling are subject to many potential uncertainties based on the material of interest, the specifics of operational handling, and local geography and meteorology. In 2011, the Electric Power Research Institute (EPRI) undertook the first of three phases of a field monitoring study at a power plant that investigated fugitive emissions of PM2.5 and PM10-2.5 from a large dry storage coal fly ash pile. The results incorporated ambien...

2012-06-06T23:59:59.000Z

12

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

SciTech Connect

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

13

Infrared emission from interplanetary dust  

Science Conference Proceedings (OSTI)

Standard models of the interplanetary dust emission fail to account satisfactorily for IR observations. A new model of the dust, based on very simple assumptions on the grain structure (spherical and homogeneous) and chemical composition (astronomical silicates, graphite, blackbodies) is developed. Updated values of the refractive indexes have been included in the analysis. The predictions of the model (absolute values of the fluxes, spectral shape, elongation dependence of the emission) have then been compared with all the available IR observations performed by the ARGO (balloon-borne experiment by University of Rome), AFGL and Zodiacal Infrared Project (ZIP) (rocket experiments by Air Force Geophysics Laboratory, Bedford, Mass.), and IRAS satellite. Good agreement is found when homogeneous data sets from single experiments (e.g., ZIP and ARGO) are considered separately. 19 references.

Temi, P.; De Bernardis, P.; Masi, S.; Moreno, G.; Salama, A.

1989-02-01T23:59:59.000Z

14

Secondary Electron Emission from Dust and Its Effect on Charging  

Science Conference Proceedings (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

15

Reducing dust emissions at OAO Alchevskkoks coke battery 10A  

Science Conference Proceedings (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

16

Influence of Dust on the Emissivity of Radiant Barriers  

E-Print Network (OSTI)

A model of the radiant heat transfer in attics containing dusty radiant barriers was developed. The geometrical model was a triangular enclosure in which the temperatures of the enclosing surfaces were known. The dust particles were simulated as areas of diameter equal to the mean diameter of the real dust to be analyzed and an emissivity substantially larger than the emissivity of the radiant barrier. Several shape factors were calculated using shape factor algebra, including a procedure to find the shape factor between a small rectangle and a triangular surface perpendicular to the rectangular plane. The thermal model was developed using the "Net Radiation Method" in which the net heat exchange between the surfaces surrounding the enclosure was found by solving a system of equations that has as many equations as the number of surfaces involved in the calculations. This led to the necessity of solving a very large system of equations in order to account for the dust particles in a representative amount. The solution of the system of equations provided the heat flux for each element of the enclosure. Finally, replacing the radiant barrier and the dust particles for an equivalent surface corresponding to the dusty radiant barrier provided the means to calculate the emissivity of this dusty radiant barrier. The theoretical model was tested to assess its validity. The experimentation was carried out using a reflection emissometer to measure the increase of the emissivity of aluminum radiant barrier when known quantities of dust were artificially applied to it. The experimental results showed good agreement with the theoretical model. A linear relationship between the emissivity and the area of dust coverage was found. The simple relation developed can be used in future research which still has to deal with the determination of the area of dust coverage by using the geometrical model of dust superposition or other statistical model to simulate the random location of random size dust particles over the radiant barrier.

Noboa, Homero L.

1991-12-01T23:59:59.000Z

17

Infrared Emission from Interstellar Dust. III. The Small Magellanic Cloud  

E-Print Network (OSTI)

The infrared (IR) emission from interstellar dust in the Small Magellanic Cloud (SMC) is modelled using a mixture of amorphous silicate and carbonaceous grains, including a population of polycyclic aromatic hydrocarbon (PAH) molecules. (1) It is shown that this dust model is able to reproduce the spectral energy distribution from near-IR to far-IR for the entire SMC Bar region, provided the PAH abundance in the SMC Bar region is very low. (2) The IR spectrum of the SMCB1#1 molecular cloud can also be reproduced by our dust model provided the PAH abundance is increased relative to the overall SMC Bar. The PAHs in SMCB1#1 incorporate ~3% of the SMC C abundance, compared to environmental conditions. Other possibilities such as super-hydrogenation of PAHs and softening of the starlight spectrum are also discussed.

Aigen Li; B. T. Draine

2001-12-05T23:59:59.000Z

18

Radionuclide Air Emission Report for 2009  

E-Print Network (OSTI)

the public from airborne radionuclide emissions. We requestfor Emissions of Radionuclides Other Than Radon FromFugitive Air Emissions of Radionuclides from Diffuse Sources

Wahl, Linnea

2010-01-01T23:59:59.000Z

19

Radionuclide Air Emission Report for 2011  

E-Print Network (OSTI)

LBNL-470E-20Ì1 Radionuclide Air Emission Report for Preparedfor Emissions of Radionuclides Other Than Radon FromFugitive Air Emissions of Radionuclides from Diffuse Sources

Wahl, Linnea

2012-01-01T23:59:59.000Z

20

Evidence for dust emission in the Warm Ionised Medium using WHAM data  

E-Print Network (OSTI)

We have used the WHAM H_alpha survey and Leiden/Dwingeloo HI data to decompose the Far-infrared emission (from 100 to 1000 micron) at high Galactic latitude into components associated with the Warm Ionised Medium (WIM) and the Warm Neutral Medium (WNM). This decomposition is possible for the first time thanks to preliminary WHAM data that cover a significant fraction of the sky (about 10%). We confirm the first detection of dust emission from the WIM (Lagache et al. 1999) and show that the WIM dust temperature and emissivity are very similar to those in the WNM. The analysis suggests moreover that about 25% of the far-IR dust emission at high galactic latitude is uncorrelated with the HI gas. The decomposition again reveals a Cosmic Far-Infrared Background (CFIRB) which is determined for the first time from 100 to 1000 micron using two independant gas tracers.

Lagache, G; Reynolds, R J; Tufte, S L

1999-01-01T23:59:59.000Z

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.


21

Evidence for dust emission in the Warm Ionised Medium using WHAM data  

E-Print Network (OSTI)

We have used the WHAM H_alpha survey and Leiden/Dwingeloo HI data to decompose the Far-infrared emission (from 100 to 1000 micron) at high Galactic latitude into components associated with the Warm Ionised Medium (WIM) and the Warm Neutral Medium (WNM). This decomposition is possible for the first time thanks to preliminary WHAM data that cover a significant fraction of the sky (about 10%). We confirm the first detection of dust emission from the WIM (Lagache et al. 1999) and show that the WIM dust temperature and emissivity are very similar to those in the WNM. The analysis suggests moreover that about 25% of the far-IR dust emission at high galactic latitude is uncorrelated with the HI gas. The decomposition again reveals a Cosmic Far-Infrared Background (CFIRB) which is determined for the first time from 100 to 1000 micron using two independant gas tracers.

G. Lagache; L. M. Haffner; R. J. Reynolds; S. L. Tufte

1999-11-18T23:59:59.000Z

22

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

Science Conference Proceedings (OSTI)

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

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

2010-09-20T23:59:59.000Z

23

FEWG beyond SF6: Managing Halocarbon Emissions  

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

FEWG beyond SF6: Managing Halocarbon Emissions Corrie Clark, Ph.D. Environmental Science Division Fugitive Emissions Working Group November 15, 2011 Review of Progress to Date ...

24

Progress Report on SF6 Emissions Management  

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

Progress Report on SF 6 Emissions Management Greg Barrett Environmental Engineer Argonne National Laboratory October 14, 2010 Fugitive Emissions Working Group Assessment of SF 6...

25

Infrared [Fe II] and Dust Emissions from Supernova Remnants  

E-Print Network (OSTI)

Supernova remnants (SNRs) are strong thermal emitters of infrared radiation. The most prominent lines in the near-infrared spectra of SNRs are [Fe II] lines. The [Fe II] lines are from shocked dense atomic gases, so they trace SNRs in dense environments. After briefly reviewing the physics of the [Fe II] emission in SNR shocks, I describe the observational results which show that there are two groups of SNRs bright in [Fe II] emission: middle-aged SNRs interacting with molecular clouds and young core-collapse SNRs in dense circumstellar medium. The SNRs belonging to the former group are also bright in near-infrared H$_2$ emission, indicating that both atomic and molecular shocks are pervasive in these SNRs. The SNRs belonging to the latter group have relatively small radii in general, implying that most of them are likely the remnants of SN IIL/b or SN IIn that had strong mass loss before the explosion. I also comment on the "[Fe II]-H$_2$ reversal" in SNRs and on using the [Fe II]-line luminosity as an indic...

Koo, Bon-Chul

2013-01-01T23:59:59.000Z

26

Dust in the polar region as a major contributor to the IR emission of AGN  

E-Print Network (OSTI)

(abridged) It is generally assumed that the distribution of dust on parsec scales forms a geometrically- and optically-thick entity in the equatorial plane around the accretion disk and broad-line region - dubbed "dust torus" - that emits the bulk of the sub-arcsecond-scale IR emission and gives rise to orientation-dependent obscuration. Here we report detailed interferometry observations of the unobscured (type 1) AGN in NGC 3783 that allow us to constrain the size, elongation, and direction of the mid-IR emission with high accuracy. The mid-IR emission is characterized by a strong elongation toward position angle PA -52 deg, closely aligned with the polar axis (PA -45 deg). We determine half-light radii along the major and minor axes at 12.5 {\\mu}m of (4.23 +/- 0.63) pc x (1.42 +/- 0.21) pc, which corresponds to intrinsically-scaled sizes of (69.4 +/- 10.8) rin x (23.3 +/- 3.5) rin for the inner dust radius of rin = 0.061 pc as inferred from near-IR reverberation mapping. This implies an axis ratio of 3:1, ...

Hoenig, Sebastian F; Tristram, Konrad R W; Prieto, M Almudena; Gandhi, Poshak; Asmus, Daniel; Antonucci, Robert; Burtscher, Leonard; Duschl, Wolfgang J; Weigelt, Gerd

2013-01-01T23:59:59.000Z

27

Radionuclide Air Emission Report for 2008  

E-Print Network (OSTI)

Fugitive Air Emissions of Radionuclides from Diffuse SourcesHazardous Air Pollutants (Radionuclides), Availability ofLBNL to Revise Its Radionuclide NESHAP Monitoring Approach,”

Wahl, Linnea

2009-01-01T23:59:59.000Z

28

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

Open Energy Info (EERE)

Yes Implementing Sector StateProvince Program Administrator Rhode Island Department of Environmental Management Primary Website http:www.dem.ri.govpubsregsregsair...

29

Production of High Quality Dust Control Foam to Minimize Moisture Addition to Coal  

E-Print Network (OSTI)

Foam is displacing wet suppression as the method of choice for controlling fugitive emissions from coal. Coal treated by wet suppression consumes through moisture addition, a heat energy equivalent of 1 ton out of every 500 tons fired. The application of foam requires less than 10% of the moisture usually required for wet suppression. In addition, foam is a much more effective dust suppressant, especially on respirable dust (particle with an aerodynamic diameter less than 10 microns). To achieve maximum benefit from foam dust control, efficient on-site production of dry, stable foam is required. This paper discusses the basics of foam production and the many variables affecting foam expansion ratios. Successful applications of foam are also described.

Termine, F.; Jordan, S. T.

1985-05-01T23:59:59.000Z

30

High Resolution Millimeter-Wave Mapping of Linearly Polarized Dust Emission: Magnetic Field Structure in Orion  

E-Print Network (OSTI)

We present 1.3 and 3.3 mm polarization maps of Orion-KL obtained with the BIMA array at approximately 4 arcsec resolution. Thermal emission from magnetically aligned dust grains produces the polarization. Along the Orion ``ridge'' the polarization position angle varies smoothly from about 10 degrees to 40 degrees, in agreement with previous lower resolution maps. In a small region south of the Orion ``hot core,'' however, the position angle changes by 90 degrees. This abrupt change in polarization direction is not necessarily the signpost of a twisted magnetic field. Rather, in this localized region processes other than the usual Davis-Greenstein mechanism might align the dust grains with their long axes parallel with the field, orthogonal to their normal orientation.

R. Rao; R. M. Crutcher; R. L. Plambeck; M. C. H. Wright

1998-05-21T23:59:59.000Z

31

Projections of Full-Fuel-Cycle Energy and Emissions Metrics  

E-Print Network (OSTI)

et al. 2010). Shale gas production by hydraulic fracturing (anticipated growth in shale gas production is expected toFugitive emissions from shale gas production are the subject

Coughlin, Katie

2013-01-01T23:59:59.000Z

32

Reducing SF6 Emissions @ PPPL  

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

96.4 88.4 Fuel Consumption Emissions 2015 1823.8 Fugitive Emissions Refrigerant 160 241.2 SF6 38360 21042.8 Scope 2 -Indirect Electricity Purchase 13816 13855 Scope 3 -...

33

Background dust emission following grassland fire: a snapshot across the particle-size spectrum highlights how high-resolution measurements enhance detection  

SciTech Connect

Dust emission rates vary temporally and with particle size. Many studies of dust emission focus on a particular temporal scale and the portion of the particle-size spectrum associated with a single instrument; fewer studies have assessed dust emission across the particle-size spectrum and associated temporal scales using multiple instruments. Particularly lacking are measurements following disturbances such as fire that are high-resolution and focused on finer particles - those with direct implications for human health and potential for long-distance biogeochemical transport - during less windy but more commonly occurring background conditions. We measured dust emissions in unburned and burned semiarid grassland using four different instruments spanning different combinations of temporal resolution and particle-size spectrum: Big Springs Number Eight (BSNE) and Sensit instruments for larger saltating particles, DustTrak instruments for smaller suspended particles, and Total Suspended Particulate (TSP) samplers for measuring the entire range of particle sizes. Unburned and burned sites differed in vegetation cover and aerodynamic roughness, yet surprisingly differences in dust emission rates were only detectable for saltation using BSNE and for smaller aerosols using DustTrak. Our results, surprising in the lack of consistently detected differences, indicate that high-resolution DustTrak measurements offered the greatest promise for detecting differences in background emission rates and that BSNE samplers, which integrate across height, were effective for longer intervals. More generally, our results suggest that interplay between particle size, temporal resolution, and integration across time and height can be complex and may need to be considered more explicitly for effective sampling for background dust emissions.

Whicker, Jeffrey J [Los Alamos National Laboratory; Martin, Luis M [UNIV OF ARIZONA; Field, Jason P [UNIV OF ARIZONA; Villegas, Juan C [UNIV OF ARIZONA; Brehsears, David D [UNIV OF ARIZONA; Law, Darin J [UNIV OF ARIZONA; Urgeghe, Anna M [UNIV OF ARIZONA

2009-01-01T23:59:59.000Z

34

H2O Maser Emission in Circumstellar Envelopes around AGB Stars: Physical Conditions in Gas-Dust Clouds  

E-Print Network (OSTI)

The pumping of 22.2-GHz H$_2$O masers in the circumstellar envelopes of asymptotic giant branch stars has been simulated numerically. The physical parameters adopted in the calculations correspond to those of the circumstellar envelope around IK Tau. The one-dimensional plane-parallel structure of the gas-dust cloud is considered. The statistical equilibrium equations for the H$_2$O level populations and the thermal balance equations for the gas-dust cloud are solved self-consistently. The calculations take into account 410 rotational levels belonging to the five lowest vibrational levels of H$_2$O. The stellar radiation field is shown to play an important role in the thermal balance of the gas-dust cloud due to the absorption of emission in rotational-vibrational H$_2$O lines. The dependence of the gain in the 22.2-GHz maser line on the gas density and H$_2$O number density in the gas-dust cloud is investigated. Gas densities close to the mean density of the stellar wind, 10$^7-10^8$ cm$^{-3}$, and a high re...

Nesterenok, Aleksandr

2013-01-01T23:59:59.000Z

35

Notes from December 6, 2012, DOE Fugitive Emissions Working Group...  

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

dropped to less than 4% by 2010. Final Review of Paper on SF 6 Byproduct Safety (Jane Powers, HS-21) Jane Powers described the two main changes that were made to the SF 6...

36

Notes from November 15, 2011 DOE Fugitive Emissions Working Group...  

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

Silverman, FEWG Chair, and Contributions from the field) The 2011 DOE Strategic Sustainability Performance Plan (SSPP) has been released and is available on the SPO's website...

37

Chasing Down Fugitive Emissions | Princeton Plasma Physics Lab  

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

April 25, 2011 Tweet Widget Facebook Like Google Plus One PPPL's Tim Stevenson takes inventory of the SF6 levels at a power supply tank for NSTX. (Photo by Elle...

38

CAN DUST EMISSION BE USED TO ESTIMATE THE MASS OF THE INTERSTELLAR MEDIUM IN GALAXIES-A PILOT PROJECT WITH THE HERSCHEL REFERENCE SURVEY  

SciTech Connect

The standard method for estimating the mass of the interstellar medium (ISM) in a galaxy is to use the 21 cm line to trace the atomic gas and the CO 1-0 line to trace the molecular gas. In this paper, we investigate the alternative technique of using the continuum dust emission to estimate the mass of gas in all phases of the ISM. Using Herschel observations of 10 galaxies from the Herschel Reference Survey and the Herschel Virgo Cluster Survey, we show that the emission detected by Herschel is mostly from dust that has a temperature and emissivity index similar to that of dust in the local ISM in our galaxy, with the temperature generally increasing toward the center of each galaxy. We calibrate the dust method using the CO and 21 cm observations to provide an independent estimate of the mass of hydrogen in each galaxy, solving the problem of the uncertain ''X-factor'' for the CO observations by minimizing the dispersion in the ratio of the masses estimated using the two methods. With the calibration for the dust method and the estimate of the X-factor produced in this way, the dispersion in the ratio of the two gas masses is 25%. The calibration we obtain for the dust method is similar to those obtained from Herschel observations of M31 and from Planck observations of the Milky Way. We discuss the practical problems in using this method.

Eales, Stephen; Smith, Matthew W. L.; Auld, Robbie; Davies, Jon; Gear, Walter; Gomez, Haley [School of Physics and Astronomy, Cardiff University, Queens Buildings, The Parade, Cardiff CF24 3AA (United Kingdom); Baes, Maarten; De Looze, Ilse; Gentile, Gianfranco; Fritz, Jacopo [Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, B-9000 Gent (Belgium); Bendo, George J. [UK ALMA Regional Centre Node, Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Bianchi, Simone [INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Firenze (Italy); Boselli, Alessandro; Ciesla, Laure [Laboratoire d'Astrophysique de Marseilles, UMR6110 CNRS, 38 rue F. Joliot-Curie, F-1338 Marseilles (France); Clements, David [Astrophysics Group, Imperial College, Blackett Lab, Prince Consort Road, London SW7 2AZ (United Kingdom); Cooray, Asantha [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Cortese, Luca [European Southern Observatory, Karl-Schwarzschild-Strasse 2 D-85748, Garching bei Munchen (Germany); Galametz, Maud [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Hughes, Tom [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China); Madden, Suzanne [Laboratoire AIM, CEA/DSM-CNRS-Universite Paris Diderot, Irfu/Service d'Astrophysique, F-91191 Gif sur Yvette (France); and others

2012-12-20T23:59:59.000Z

39

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

SciTech Connect

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

40

"Blue Sky" Approaches to Reduce Greenhouse Gas Emissions: An Initial Assessment of Potential New Types of Greenhouse Gas Emissions Offsets  

Science Conference Proceedings (OSTI)

This report provides an initial assessment of potential new approaches to reducing greenhouse gas (GHG) emissions that might be capable of generating large-scale GHG emissions offsets at relatively low cost compared to other GHG mitigation options. The nine potential blue sky approaches assessed in this report include biochar, destruction of ozone depleting substances, control of natural fugitive methane seeps from coal seams, control of fugitive natural gas emissions associated with hydraulic fracturing...

2011-12-22T23:59:59.000Z

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

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

42

The Bolocam Galactic Plane Survey IV: 1.1 and 0.35 mm Dust Continuum Emission in the Galactic Center Region  

E-Print Network (OSTI)

The Bolocam Galactic Plane Survey (BGPS) data for a six square degree region of the Galactic plane containing the Galactic center is analyzed and compared to infrared and radio continuum data. The BGPS 1.1 mm emission consists of clumps interconnected by a network of fainter filaments surrounding cavities, a few of which are filled with diffuse near-IR emission indicating the presence of warm dust or with radio continuum characteristic of HII regions or supernova remnants. New 350 {\\mu}m images of the environments of the two brightest regions, Sgr A and B, are presented. Sgr B2 is the brightest mm-emitting clump in the Central Molecular Zone and may be forming the closest analog to a super star cluster in the Galaxy. The Central Molecular Zone (CMZ) contains the highest concentration of mm and sub-mm emitting dense clumps in the Galaxy. Most 1.1 mm features at positive longitudes are seen in silhouette against the 3.6 to 24 {\\mu}m background observed by the Spitzer Space Telescope. However, only a few clumps ...

Bally, John; Battersby, Cara; Bradley, Eric Todd; Cyganowski, Claudia; Dowell, Darren; Drosback, Meredith; Dunham, Miranda K; Evans, Neal J; Ginsburg, Adam; Glenn, Jason; Harvey, Paul; Mills, Elisabeth; Merello, Manuel; Rosolowsky, Erik; Schlingman, Wayne; Shirley, Yancy L; Stringfellow, Guy S; Walawender, Josh; Williams, Jonathan; 10.1088/0004-637X/721/1/137

2010-01-01T23:59:59.000Z

43

Molten Metal Treatment by Salt Fluxing with Low Environmental Emissions  

SciTech Connect

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

44

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

Science Conference Proceedings (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

45

Observing Cold Dust with Herschel / SPIRE  

Science Conference Proceedings (OSTI)

A major component of the emission of many galaxies is in the Far Infrared and the Sub?mmillimeter. UV photons from stars are absorbed by dust and re?emitted at longer wavelengths. Fairly cold dust was found in large spirals by the Infrared Space Observatory and the Spitzer Observatory but their longest wavelength filters were centered at 200 and 160 microns respectively

Bernhard Schulz; The SPIRE Consortium

2010-01-01T23:59:59.000Z

46

Heterogeneous chemistry of atmospheric mineral dust particles and their resulting cloud-nucleation properties  

E-Print Network (OSTI)

global emissions of reactive chlorine from anthropogenic andnatural sources: Reactive Chlorine Emissions Inventory, J.Mineral dust is a sink for chlorine in the marine boundary

Sullivan, Ryan Christopher

2008-01-01T23:59:59.000Z

47

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

SciTech Connect

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

48

Dust feed mechanism  

DOE Patents (OSTI)

The invention is a dust feed device for delivery of a uniform supply of dust for long periods of time to an aerosolizing means for production of a dust suspension. The device utilizes at least two tandem containers having spiral brushes within the containers which transport the dust from a supply to the aerosolizer means.

Milliman, Edward M. (Benton City, WA)

1984-01-01T23:59:59.000Z

49

Dust-feed mechanism  

DOE Patents (OSTI)

The invention is a dust feed device for delivery of a uniform supply of dust for long periods of time to an aerosolizing means for production of a dust suspension. The device utilizes at least two tandem containers having spiral brushes within the containers which transport the dust from a supply to the aerosolizer means.

Milliman, E.M.

1981-04-06T23:59:59.000Z

50

The Atlantic Richfield Company Black Thunder mine haul road dust study. [Wyoming  

Science Conference Proceedings (OSTI)

An examination of the effectiveness of various haul road dust control measures was performed at ARCO's Black Thunder Mine near Wright, Wyoming by evaluating both visible observations and quantitative measurements of particle concentrations. In order to evaluate dust control effectiveness both a 300 foot (91.5 meter) and 175 foot (53.4 meter) section of the main coal haul road was selected for testing. The test sections were separated by a 200 foot (61 meter) buffer zone. Each test section was relatively straight and away from interferences from other mine sources. The five haul road treatment test sequences evaluated for control measure effectiveness were: an untreated road segment; water treatment two times per hour; water treatment four times per hour; previously chemically treated segment of haul road (ARCO 2400 dust suppressant); and testing after application of Coherex (10% dilution). By comparing uncontrolled situations with various controlled situations, an estimate of the control efficiency of the dust control measures was determined. Based upon the results of the study a fugitive dust control scheme was selected considering control effectiveness, economics and operational efficiency.

Maxwell, D.R.; Hormel, T.R.; Ives, J.A.

1982-06-01T23:59:59.000Z

51

Novel instrument for Dust Astronomy: Dust Telescope  

Science Conference Proceedings (OSTI)

The analysis of dust particles in space can tell us about their origin and interaction with the space environment that helps understanding the evolution of the solar system and the universe.1 2 There has been a significant advancement in dust detector/analyzer ...

Zoltan Sternovsky; Eberhard Grun; Keith Drake; Jianfeng Xie; Mihaly Horanyi; Ralf Srama; Sascha Kempf; Frank Postberg; Anna Mocker; Siegfried Auer; Harald Kruger

2011-03-01T23:59:59.000Z

52

Optical Investigations of Dust Particles Distribution in RF and DC Discharges  

Science Conference Proceedings (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

53

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

Science Conference Proceedings (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 (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

54

Sequim Site Radionuclide Air Emissions Report for Calendar Year 2012  

SciTech Connect

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

55

Radionuclide Air Emissions Report for the Hanford Site Calendar Year 1999  

SciTech Connect

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

56

The Smart Dust Project  

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

at putting a complete sensingcommunication platform inside a cubic millimeter, including power supply, analog and digital electronics, etc. Thousands or millions of these dust...

57

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

SciTech Connect

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

58

A SPITZER SURVEY FOR DUST IN TYPE IIn SUPERNOVAE  

Science Conference Proceedings (OSTI)

Recent observations suggest that Type IIn supernovae (SNe IIn) may exhibit late-time (>100 days) infrared (IR) emission from warm dust more than other types of core-collapse SNe. Mid-IR observations, which span the peak of the thermal spectral energy distribution, provide useful constraints on the properties of the dust and, ultimately, the circumstellar environment, explosion mechanism, and progenitor system. Due to the low SN IIn rate (<10% of all core-collapse SNe), few IR observations exist for this subclass. The handful of isolated studies, however, show late-time IR emission from warm dust that, in some cases, extends for five or six years post-discovery. While previous Spitzer/IRAC surveys have searched for dust in SNe, none have targeted the Type IIn subclass. This paper presents results from a warm Spitzer/IRAC survey of the positions of all 68 known SNe IIn within a distance of 250 Mpc between 1999 and 2008 that have remained unobserved by Spitzer more than 100 days post-discovery. The detection of late-time emission from 10 targets ({approx}15%) nearly doubles the database of existing mid-IR observations of SNe IIn. Although optical spectra show evidence for new dust formation in some cases, the data show that in most cases the likely origin of the mid-IR emission is pre-existing dust, which is continuously heated by optical emission generated by ongoing circumstellar interaction between the forward shock and circumstellar medium. Furthermore, an emerging trend suggests that these SNe decline at {approx}1000-2000 days post-discovery once the forward shock overruns the dust shell. The mass-loss rates associated with these dust shells are consistent with luminous blue variable progenitors.

Fox, Ori D. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Chevalier, Roger A.; Skrutskie, Michael F. [Department of Astronomy, University of Virginia, Charlottesville, VA 22903 (United States); Soderberg, Alicia M. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Filippenko, Alexei V.; Ganeshalingam, Mohan; Silverman, Jeffrey M.; Smith, Nathan; Steele, Thea N., E-mail: ori.d.fox@nasa.gov [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States)

2011-11-01T23:59:59.000Z

59

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

SciTech Connect

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

60

U.K. HiGEM: Simulations of Desert Dust and Biomass Burning Aerosols with a High-Resolution Atmospheric GCM  

Science Conference Proceedings (OSTI)

The atmospheric component of the United Kingdom’s new High-resolution Global Environmental Model (HiGEM) has been run with interactive aerosol schemes that include biomass burning and mineral dust. Dust emission, transport, and deposition are ...

M. J. Woodage; A. Slingo; S. Woodward; R. E. Comer

2010-04-01T23:59:59.000Z

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.


61

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

62

Graphite Dust Deflagration  

Science Conference Proceedings (OSTI)

The graphite moderators of retired gas-cooled nuclear reactors present a difficult challenge during demolition activities. As part of the EPRI graphite initiative on the technical issues involved in the management and disposal of irradiated nuclear graphite, this report examines the international data on dust deflagration relevant to the decommissioning of graphite-moderated reactors. The report concludes that the risk of an explosion involving graphite dust during decommissioning is extremely low, and s...

2007-03-27T23:59:59.000Z

63

Graphite Dust Deflagration  

Science Conference Proceedings (OSTI)

The graphite moderators of retired gas-cooled nuclear reactors present a difficult challenge during demolition activities. As part of the EPRI graphite initiative on the technical issues involved in the management and disposal of irradiated nuclear graphite, EPRI Report 1014797 Graphite Dust Deflagration: A Review of International Data with Particular Reference to the Decommissioning of Graphite Moderated Reactors (March 2007) examined the international data on dust deflagration relevant to the decommiss...

2007-10-03T23:59:59.000Z

64

Fractal dust grains in plasma  

Science Conference Proceedings (OSTI)

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

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

2012-09-15T23:59:59.000Z

65

Determining inert content in coal dust/rock dust mixture  

DOE Patents (OSTI)

A method and apparatus for determining the inert content of a coal dust and rock dust mixture uses a transparent window pressed against the mixture. An infrared light beam is directed through the window such that a portion of the infrared light beam is reflected from the mixture. The concentration of the reflected light is detected and a signal indicative of the reflected light is generated. A normalized value for the generated signal is determined according to the relationship .phi.=(log i.sub.c `log i.sub.co) / (log i.sub.c100 -log i.sub.co) where i.sub.co =measured signal at 0% rock dust i.sub.c100 =measured signal at 100% rock dust i.sub.c =measured signal of the mixture. This normalized value is then correlated to a predetermined relationship of .phi. to rock dust percentage to determine the rock dust content of the mixture. The rock dust content is displayed where the percentage is between 30 and 100%, and an indication of out-of-range is displayed where the rock dust percent is less than 30%. Preferably, the rock dust percentage (RD%) is calculated from the predetermined relationship RD%=100+30 log .phi.. where the dust mixture initially includes moisture, the dust mixture is dried before measuring by use of 8 to 12 mesh molecular-sieves which are shaken with the dust mixture and subsequently screened from the dust mixture.

Sapko, Michael J. (Finleyville, PA); Ward, Jr., Jack A. (Oakmont, PA)

1989-01-01T23:59:59.000Z

66

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

Science Conference Proceedings (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

67

Dust cluster explosion  

Science Conference Proceedings (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

68

Dust control for draglines  

SciTech Connect

Monitoring dust levels inside draglines reveals room for improvement in how filtration systems are used and maintained. The Australian firm BMT conducted a field test program to measure airflow parameters, dust fallout rates and dust concentrations, inside and outside the machine house, on four draglines and one shovel. The study involved computational fluid dynamics (CFD) simulations. The article describes how the tests were made and gives results. It was not possible to say which of the two main filtration systems currently used on Australian draglines - Dynavane or Floseps - performs better. It would appear that more frequent maintenance and cleaning would increase the overall filtration performance and systems could be susceptible to repeat clogging in a short time. 2 figs., 1 photos.

Grad, P.

2009-09-15T23:59:59.000Z

69

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 at Texas A&M University in which a radiation energy balance inside the attic enclosure was developed. The particles were considered as flat, circular planes, all having the same radii. That early model showed that there was a linear relationship between the fraction of area of the foil covered by dust and the mean absorptivity of the dusty radiant barrier. In the present work, it was found that the assumption of treating the dust particles as plane circles, underestimated the effective area of the particles by about 20%. Experimental measurements indicated that dust particles achieved the same temperature as the radiant barrier. The new model used the linear relationship just described, and simulated the dust particles as flat circular planes having random radii and laying in random locations within the radiant barrier surface. The new model calculated the fraction of radiant barrier area covered by particles using a digital array in which the clean barrier was represented as zeroes and the dust particles were represented as a set of ones appropriately dimensioned inside the array. The experimentation used natural dust and Arizona Road Test Dust. Using an infrared emissometer, the emissivities (absorptivities) of the clean and dusty barriers were measured and using an electronic scale, the dust loading was measured. An electron microscope was used to experimentally find the fraction of radiant barrier covered by the dust particles to correlate the experimentally found absorptivity with the experimentally found fraction of dust coverage. The limited experimental data available were also used to correlate the absorptivity of the dusty radiant barrier with the time of dust accumulation and the location of the barrier inside the attic. A linear relationship between the absorptivity and the time of dust accumulation was found that can be applied to predict future barrier effectiveness based upon the rate of dust accumulation for a given location.

Noboa, Homero L.

1993-08-01T23:59:59.000Z

70

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

71

HEP Fugitive - Higgs Boson  

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

FOR DISCOVERY The Higgs Graphic of a plaid H Graphic made in 2001 Aliases: Higgs, Higgs Boson, H0, h0 DESCRIPTION Mass: at least 114 GeV ? Spin: Zero Charge: Netural Particle...

72

Emissions & Emission Controls - FEERC  

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

Emissions and Emission Controls In conjunction with the research efforts at FEERC to improve fuel efficiency and reduce petroleum use, research on emissions is conducted with two...

73

Global dust model intercomparison in AeroCom phase I  

Science Conference Proceedings (OSTI)

Abstract. This study presents the results of a broad intercomparison of a total of 15 global aerosol models within the AeroCom project. Each model is compared to observations related to desert dust aerosols, their direct radiative effect, and their impact on the biogeochemical cycle, i.e., aerosol optical depth (AOD) and dust deposition. Additional comparisons to Angstr¨om exponent (AE), coarse mode AOD and dust surface concentrations are included to extend the assessment of model performance and to identify common biases present in models. These data comprise a benchmark dataset that is proposed for model inspection and future dust model development. There are large differences among the global models that simulate the dust cycle and its impact on climate. In general, models simulate the climatology of vertically integrated parameters (AOD and AE) within a factor of two whereas the total deposition and surface concentration are reproduced within a factor of 10. In addition, smaller mean normalized bias and root mean square errors are obtained for the climatology of AOD and AE than for total deposition and surface concentration. Characteristics of the datasets used and their uncertainties may influence these differences. Large uncertainties still exist with respect to the deposition fluxes in the southern oceans. Further measurements and model studies are necessary to assess the general model performance to reproduce dust deposition in ocean regions sensible to iron contributions. Models overestimate the wet deposition in regions dominated by dry deposition. They generally simulate more realistic surface concentration at stations downwind of the main sources than at remote ones. Most models simulate the gradient in AOD and AE between the different dusty regions. However the seasonality and magnitude of both variables is better simulated at African stations than Middle East ones. The models simulate the offshore transport of West Africa throughout the year but they overestimate the AOD and they transport too fine particles. The models also reproduce the dust transport across the Atlantic in the summer in terms of both AOD and AE but not so well in winter-spring nor the southward displacement of the dust cloud that is responsible of the dust transport into South America. Based on the dependency of AOD on aerosol burden and size distribution we use model bias with respect to AOD and AE to infer the bias of the dust emissions in Africa and the Middle East. According to this analysis we suggest that a range of possible emissions for North Africa is 400 to 2200 Tg yr?1 and in the Middle East 26 to 526 Tg yr?1.

Huneeus, N.; Schulz, M.; Balkanski, Y.; Griesfeller, J.; Prospero, J.; Kinne, Stefan; Bauer, S.; Boucher, O.; Chin, M.; Dentener, F.; Diehl, T.; Easter, Richard C.; Fillmore, D.; Ghan, Steven J.; Ginnoux, P.; Grini, A.; Horowitz, L.; Koch, D.; Krol, M.; Landing, W.; Liu, Xiaohong; Mahowald, N.; Miller, R.; Morcrette, J. -J.; Myhre, G.; Penner, J.; Perlwitz, J.; Stier, P.; Takemura, T.; Zender, C. S.

2011-08-18T23:59:59.000Z

74

Dust in Protoplanetary Disks  

E-Print Network (OSTI)

We critically examine the best lines of evidence for grain growth in protoplanetary disks, based on modelling of observed spectral energy distributions and images of T Tauri and Herbig Ae stars. The data are consistent with millimeter-sized grains near disk midplanes, and micron-sized grains near disk surfaces. We review three channels by which grains can grow, including direct condensation from the vapor phase, grain-grain collisional sticking, and gravitational instability. The utility of dust in identifying as yet unseen extrasolar planets is highlighted.

Chiang, E I

2003-01-01T23:59:59.000Z

75

Dust in Protoplanetary Disks  

E-Print Network (OSTI)

We critically examine the best lines of evidence for grain growth in protoplanetary disks, based on modelling of observed spectral energy distributions and images of T Tauri and Herbig Ae stars. The data are consistent with millimeter-sized grains near disk midplanes, and micron-sized grains near disk surfaces. We review three channels by which grains can grow, including direct condensation from the vapor phase, grain-grain collisional sticking, and gravitational instability. The utility of dust in identifying as yet unseen extrasolar planets is highlighted.

E. I. Chiang

2003-09-08T23:59:59.000Z

76

A Dust Prediction System with TOMS Initialization  

Science Conference Proceedings (OSTI)

A dust prediction system, developed earlier at the University of Athens within the framework of the Mediterranean Dust Experiment (MEDUSE) project, was enhanced at Tel Aviv University to support the Israeli–American Mediterranean Israeli Dust ...

P. Alpert; S. O. Krichak; M. Tsidulko; H. Shafir; J. H. Joseph

2002-09-01T23:59:59.000Z

77

Climate Response to Soil Dust Aerosols  

Science Conference Proceedings (OSTI)

The effect of radiative forcing by soil dust aerosols upon climate is calculated. Two atmospheric GCM (AGCM) simulations are compared, one containing a prescribed seasonally varying concentration of dust aerosols, and the other omitting dust. ...

R. L. Miller; I. Tegen

1998-12-01T23:59:59.000Z

78

A Spitzer search for cold dust within globular clusters  

E-Print Network (OSTI)

Globular cluster stars evolving off the main sequence are known to lose mass, and it is expected that some of the lost material should remain within the cluster as an intracluster medium (ICM). Most attempts to detect such an ICM have been unsuccessful. The Multiband Imaging Photometer for Spitzer on the Spitzer Space Telescope was used to observe eight Galactic globular clusters in an attempt to detect the thermal emission from ICM dust. Most clusters do not have significant detections at 70 microns; one cluster, NGC 6341, has tentative evidence for the presence of dust, but 90 micron observations do not confirm the detection. Individual 70 micron point sources which appear in several of the cluster images are likely to be background galaxies. The inferred dust mass and upper limits are solar masses, well below expectations for cluster dust production from mass loss in red and asymptotic giant branch stars. This implies that either globular cluster dust production is less efficient, or that ICM rem...

Barmby, P; Woodward, C E; Gehrz, R D; van Loon, J Th; Fazio, G G; Marengo, M; Polomski, E

2008-01-01T23:59:59.000Z

79

A Simulated Climatology of Asian Dust Aerosol and Its Trans-Pacific Transport. Part I: Mean Climate and Validation  

Science Conference Proceedings (OSTI)

The Northern Aerosol Regional Climate Model (NARCM) was used to construct a 44-yr climatology of spring Asian dust aerosol emission, column loading, deposition, trans-Pacific transport routes, and budgets during 1960–2003. Comparisons with ...

T. L. Zhao; S. L. Gong; X. Y. Zhang; J-P. Blanchet; I. G. McKendry; Z. J. Zhou

2006-01-01T23:59:59.000Z

80

On Absorption by Circumstellar Dust, With the Progenitor of SN2012aw as a Case Study  

E-Print Network (OSTI)

We use the progenitor of SN2012aw to illustrate the consequences of modeling circumstellar dust using Galactic (interstellar) extinction laws that (1) ignore dust emission in the near-IR and beyond; (2) average over dust compositions, and (3) mis-characterize the optical/UV absorption by assuming that scattered photons are lost to the observer. The primary consequences for the progenitor of SN2012aw are that both the luminosity and the absorption are significantly over-estimated. In particular, the stellar luminosity is most likely in the range 10^4.8 0.3 micron) and total (absorption plus scattering) V-band optical depth (tau < 20). These do not include the contributions of dust emission, but provide a simple, physical alternative to incorrectly using interstellar extinction laws.

Kochanek, C S; Dai, X

2012-01-01T23:59:59.000Z

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.


81

Spitzer Infrared Spectrograph Observations of Magellanic Cloud Planetary Nebulae: the nature of dust in low metallicity circumstellar ejecta  

E-Print Network (OSTI)

We present 5 - 40 micron spectroscopy of 41 planetary nebulae (PNe) in the Magellanic Clouds, observed with the Infrared Spectrograph on board the Spitzer Space Telescope. The spectra show the presence of a combination of nebular emission lines and solid-state features from dust, superimposed on the thermal IR continuum. By analyzing the 25 LMC and 16 SMC PNe in our sample we found that the IR spectra of 14 LMC and 4 SMC PNe are dominated by nebular emission lines, while the other spectra show solid-state features. We observed that the solid-state features are compatible with carbon-rich dust grains (SiC, polycyclic aromatic hydrocarbons (PAHs), etc.) in most cases, except in three PNe showing oxygen-rich dust features. The frequency of carbonaceous dust features is generally higher in LMC than in SMC PNe. The spectral analysis allowed the correlations of the dust characteristics with the gas composition and morphology, and the properties of the central stars. We found that: 1) all PNe with carbonaceous dust features have C/O>1, none of these being bipolar or otherwise highly asymmetric; 2) all PNe with oxygen-rich dust features have C/Oproduction efficiency depends on metallicity, with low metallicity environments not favoring dust production.

L. Stanghellini; P. Garcia-Lario; D. A. Garcia-Hernandez; J. V. Perea-Calderon; J. E. Davies; A. Manchado; E. Villaver; R. A. Shaw

2007-09-04T23:59:59.000Z

82

A Simple Thermodynamical Theory for Dust Devils  

Science Conference Proceedings (OSTI)

Based on the heat engine framework, a simple scaling theory for dust devils is proposed and compared to observations. This theory provides a simple physical interpretation for many of the observed characteristics of dust devils. In particular, it ...

Nilton O. Rennó; Matthew L. Burkett; Matthew P. Larkin

1998-11-01T23:59:59.000Z

83

Adding coal dust to coal batch  

Science Conference Proceedings (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

84

Microwave Emission at High Galactic Latitudes  

E-Print Network (OSTI)

We use the COBE Differential Microwave Radiometers (DMR) 4-year sky maps to model Galactic microwave emission at high latitudes (|b| > 20 deg). Cross-correlation of the DMR maps with Galactic template maps detects fluctuations in the high-latitude microwave sky brightness with the angular variation of the DIRBE far-infrared dust maps and a frequency dependence consistent with a superposition of dust and free-free emission. We find no significant correlations between the DMR maps and various synchrotron templates. On the largest angular scales (e.g., quadrupole), Galactic emission is comparable in amplitude to the anisotropy in the cosmic microwave background (CMB). The CMB quadrupole amplitude, after correction for Galactic emission, has amplitude $Q_{rms}$ = 10.7 uK with random uncertainty 3.6 uK and systematic uncertainty 7.1 uK from uncertainty in our knowledge of Galactic microwave emission.

A. Kogut; G. Hinshaw; A. J. Banday; C. L. Bennett; K. Gorski; G. F. Smoot; E. L. Wright

1996-01-12T23:59:59.000Z

85

The effect of stellar evolution on SiC dust grain sizes  

E-Print Network (OSTI)

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

Angela Speck; Grant Thompson; Anne Hofmeister

2005-08-04T23:59:59.000Z

86

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

E-Print Network (OSTI)

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

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

2001-09-04T23:59:59.000Z

87

Cooling season energy measurements of dust and ventilation effects on radiant barriers  

Science Conference Proceedings (OSTI)

Cooling season tests were conducted in three unoccupied ranch-style houses in Karns, Tennessee, to determine the effects on attic radiant barrier performance incurred by changes in attic ventilation area ratio, attic ventilation type, and the buildup of dust on horizontal radiant barriers. All three houses had R-19 fiberglass batt insulation in their attics. Horizontal radiant barriers were artificially dusted and the dusted barriers showed measurable performance degradations, although the dusted barriers were still superior to no radiant barriers. Dust loadings of 0.34 and 0.74 mg/cm{sup 2} reduced a clean radiant barrier surface emissivity of 0.055 to 0.125 and 0.185, respectively. Total house cooling load increases amounted to 2.3 and 8.4% compared to house loads with clean horizontal barriers, respectively. When compared to R-19 with no horizontal radiant barrier conditions, the dusted horizontal radiant barriers reduced cooling loads by about 7%. Testing showed that increasing the attic ventilation area ratio from the minimum recommended of 1/300 (1 ft{sup 2} of effective ventilation area per 300 ft{sup 2} of attic area) to 1/150 had little if any effect on the house cooling load with either truss or horizontal barriers present in the attics. Radiant barriers, however, still reduced the house cooling load. 18 refs., 17 figs., 26 tabs.

Levins, W.P.; Karnitz, M.A. (Oak Ridge National Lab., TN (USA)); Hall, J.A. (Tennessee Valley Authority, Chattanooga, TN (USA))

1990-03-01T23:59:59.000Z

88

Cooling season energy measurements of dust and ventilation effects on radiant barriers  

Science Conference Proceedings (OSTI)

Cooling season tests were conducted in three unoccupied ranch-style houses in Karns, Tennessee, to determine the effects on attic radiant barrier performance incurred by changes in attic ventilation area ratio, attic ventilation type, and the buildup of dust on horizontal radiant barriers. All three houses had R-19 fiberglass batt insulation in their attics. Horizontal radiant barriers were artificially dusted and the dusted barriers showed measurable performance degradations, although the dusted barriers were still superior to no radiant barriers. Dust loadings of 0.34 and 0.74 mg/cm{sup 2} reduced a clean radiant barrier surface emissivity of 0.055 to 0.125 and 0.185, respectively. Total house cooling load increases amounted to 2.3 and 8.4% compared to house loads with clean horizontal barriers, respectively. When compared to R-19 with no horizontal radiant barrier conditions, the dusted horizontal radiant barriers reduced cooling loads by about 7%. 18 refs., 18 figs., 30 tabs.

Levins, W.P.; Karnitz, M.A. (Oak Ridge National Lab., TN (USA)); Hall, J.A. (Tennessee Valley Authority, Knoxville, TN (USA))

1990-02-01T23:59:59.000Z

89

Dust Charging and Transport on Surfaces  

Science Conference Proceedings (OSTI)

In this paper, we review laboratory studies of dust transport on surfaces in plasmas, performed for a number of different mechanisms: 1) Dust particles were levitated in plasma sheaths by electrostatic forces balancing the gravitational force. 2) Dust was observed to spread over and lift off a surface that repels electrons in a plasma. 3) Dust was transported on surfaces having different secondary electron yields in plasma with an electron beam as a consequence of differential charging. 4) We also report a mechanism of dust transport by electric fields occurring at electron beam impact/shadow boundaries. These processes are candidates to explain the formation of dust ponds that were recently observed in craters on the asteroid Eros by the NEAR Shoemaker spacecraft.

Wang, X. [Colorado Center for Lunar Dust And Atmospheric Studies, University of Colorado, Boulder, CO 80309 (United States); Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80309 (United States); Robertson, S. [Colorado Center for Lunar Dust And Atmospheric Studies, University of Colorado, Boulder, CO 80309 (United States); Department of Physics, University of Colorado, Boulder, CO 80309 (United States); Horanyi, M. [Colorado Center for Lunar Dust And Atmospheric Studies, University of Colorado, Boulder, CO 80309 (United States); Department of Physics, University of Colorado, Boulder, CO 80309 (United States); Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80309 (United States)

2011-11-29T23:59:59.000Z

90

Optical Emission of Dusty RF Discharges: Experiment and Simulation  

Science Conference Proceedings (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

91

Dust negative ion acoustic shock waves considering dust size distribution effect  

Science Conference Proceedings (OSTI)

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

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

2012-11-15T23:59:59.000Z

92

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

Science Conference Proceedings (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

93

Novel methods for respirable dust removal. Final report  

SciTech Connect

Two novel devices with potential for controlling emissions of dust particles in the respirable size range (0.3 to 3 microns) are the electrostatically enhanced cyclone (or electrocyclone) and acoustic agglomeration. The electrocyclone combines electrostatic, inertial forces and larger unit size compared to conventional cyclones to achieve improved performance. The acoustic agglomerator uses an oscillating acoustic flow field to cause particle collision and agglomeration. The resulting large particles are then more readily separable by conventional methods. The application of these novel methods to respirable dust control in pressurized fluidized-bed combustion and conventional pulverized coal combustion for electric power generation is explored in this study. In a PFBC power plant, dust particles entrained in the combustion gases must be removed at high temperature and pressure in order to protect a gas turbine from erosion. A key technical issue in this application is whether the hot gas cleanup equipment can satisfy the NSPS, or whether supplementary stack gas cleanup, such as a baghouse, is required downstream of the gas turbine. The potential of both the electrocyclone and the acoustic agglomerator for achieving NSPS ahead of the gas turbine has been assessed. In conventional PC power plants, particulate cleanup is normally accomplished with electrostatic precipitators. However, plants burning low sulfur western coals have experienced difficulty achieving adequate particulate emissions control with electrostatic precipitators, due to the high resistivity of the coal ash. For these applications the electrocyclone or an acoustic agglomerator coupled with either an electrocyclone or more conventional removal technique, might prove attractive. The principal conclusions drawn from the work performed and the recommendations based on the results are detailed. (LTN)

1980-09-01T23:59:59.000Z

94

A Model for Long-Range Transport of Desert Dust  

Science Conference Proceedings (OSTI)

An Eulerian model for dust transport in the atmosphere is designed, and a new parameterization scheme for dust uptake is developed. The model results are quantitatively compared with satellite observations for an intense dust transport event that ...

Slobodan Ni?kovi?; Srdjan Dobri?i?

1996-11-01T23:59:59.000Z

95

Distribution of Cold dust in Orion A and B  

E-Print Network (OSTI)

Large scale far-infrared (FIR) observations of the Orion complex at 205 and 138 micron are presented with an aim of studying the distribution of cold (< 25 K) dust. The maps in these FIR bands extend over approximately 3600 sq. arcmin and cover regions around OMC-1, 2, 3 in Orion A and NGC 2023 and NGC 2024 in Orion B. Some limited regions have also been mapped at 57 micron. A total of 15 sources in Orion A and 14 in Orion B (south) have been identified from our FIR maps. Dust temperature distribution in both Orion A and Orion B (south) have been determined reliably using the maps at 205 & 138 micron obtained from simultaneous observations using almost identical beams (1.6 dia). These temperatures have been used to generate map of the optical depth at 150 micron, for the Orion B region. The coldest source detected is in OMC-3 and has a temperature of about 15 K. The diffuse FIR emission in the different sub-regions is found to vary between 25% to 50% of the total FIR emission from that sub-region.

Mookerjea, B; Rengarajan, T N; Tandon, S N; Verma, R P

2000-01-01T23:59:59.000Z

96

Distribution of Cold dust in Orion A and B  

E-Print Network (OSTI)

Large scale far-infrared (FIR) observations of the Orion complex at 205 and 138 micron are presented with an aim of studying the distribution of cold (< 25 K) dust. The maps in these FIR bands extend over approximately 3600 sq. arcmin and cover regions around OMC-1, 2, 3 in Orion A and NGC 2023 and NGC 2024 in Orion B. Some limited regions have also been mapped at 57 micron. A total of 15 sources in Orion A and 14 in Orion B (south) have been identified from our FIR maps. Dust temperature distribution in both Orion A and Orion B (south) have been determined reliably using the maps at 205 & 138 micron obtained from simultaneous observations using almost identical beams (1.6 dia). These temperatures have been used to generate map of the optical depth at 150 micron, for the Orion B region. The coldest source detected is in OMC-3 and has a temperature of about 15 K. The diffuse FIR emission in the different sub-regions is found to vary between 25% to 50% of the total FIR emission from that sub-region.

B. Mookerjea; S. K. Ghosh; T. N. Rengarajan; S. N. Tandon; R. P. Verma

2000-07-24T23:59:59.000Z

97

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

98

Heavy metals hazardous components of Eaf dust  

Science Conference Proceedings (OSTI)

Electric arc furnace (EAF) dust is a waste generated in the EAF during the steel production process. Among different wastes, EAF dust represents one of the most hazardous, since it contains heavy metals such as Zn, Fe, Cr, Cd and Pb. The goal of the ... Keywords: electric arc furnace (EAF), furnace additives, hazard components, heavy metals, scrap composition, x-ray fluorescence spectroscopy

Cristiana-Zizi Rizescu; Zorica Bacinschi; Elena Valentina Stoian; Aurora Poinescu; Dan Nicolae Ungureanu

2011-02-01T23:59:59.000Z

99

Measurement of nicotine in household dust  

Science Conference Proceedings (OSTI)

An analytical method of measuring nicotine in house dust was optimized and associations among three secondhand smoking exposure markers were evaluated, i.e., nicotine concentrations of both house dust and indoor air, and the self-reported number of cigarettes smoked daily in a household. We obtained seven house dust samples from self-reported nonsmoking homes and 30 samples from smoking homes along with the information on indoor air nicotine concentrations and the number of cigarettes smoked daily from an asthma cohort study conducted by the Johns Hopkins Center for Childhood Asthma in the Urban Environment. House dust nicotine was analyzed by isotope dilution gas chromatography-mass spectrometry (GC/MS). Using our optimized method, the median concentration of nicotine in the dust of self-reported nonsmoking homes was 11.7 ng/mg while that of smoking homes was 43.4 ng/mg. We found a substantially positive association (r=0.67, P<0.0001) between house dust nicotine concentrations and the numbers of cigarettes smoked daily. Optimized analytical methods showed a feasibility to detect nicotine in house dust. Our results indicated that the measurement of nicotine in house dust can be used potentially as a marker of longer term SHS exposure.

Kim, Sungroul [Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Institute for Global Tobacco Control, 627 N. Washington Street, 2nd Floor Baltimore, MD 21205 (United States); Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205 (United States)], E-mail: srkim@jhsph.edu; Aung, Ther; Berkeley, Emily [Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205 (United States); Diette, Gregory B. [Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205 (United States); Department of Medicine, Johns Hopkins University School of Medicine (United States); Breysse, Patrick N. [Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205 (United States)

2008-11-15T23:59:59.000Z

100

SPITZER CHARACTERIZATION OF DUST IN THE IONIZED MEDIUM OF THE LARGE MAGELLANIC CLOUD  

SciTech Connect

A systematic investigation of dust emission associated with ionized gas has so far been performed only in our Galaxy and for wavelengths longer than 60 {mu}m. Newly available Spitzer data now offer the opportunity to carry out a similar analysis in the Large Magellanic Cloud (LMC). By cross-correlating Spitzer Surveying the Agents of a Galaxy's Evolution (SAGE) data with the Australia Telescope Compact Array/Parkes H I 21 cm data, the NANTEN {sup 12}CO (J = 1-0) data, and both the Southern H-Alpha Sky Survey Atlas H{alpha} and the Parkes 6 cm data, we investigate the physical properties of dust associated with the different phases of the gas (atomic, molecular, and ionized). In particular, we study the presence and nature of dust from 3.6 to 160 {mu}m and for various regimes of ionized gas, spanning emission measures from {approx}1 pc cm{sup -6} (diffuse component) to {approx}10{sup 3}pc cm{sup -6} (H II regions). Using a dust emission model and testing our results with several radiation field spectra, we show that dust in ionized gas is warmer than dust associated with other phases (atomic and molecular). We also find a decrease of the polycyclic aromatic hydrocarbon (PAH) relative abundance with respect to big grains, as well as an increase of the near-infrared (NIR) continuum. These three results (i.e., warmer temperature, decrease of PAH abundance, and increase of the NIR continuum) are found consistently for all regimes of ionized gas. On the contrary, the molecular phase appears to provide favorable conditions for the survival of PAHs. Furthermore, the very small grain relative abundance tends to increase in the ionized phase, especially in bright H II regions. Last but not least, our analysis shows that the emissivity of dust associated with ionized gas is lower in the LMC than in our Galaxy and that this difference is not accounted for by the lower metallicity of the LMC.

Paradis, Deborah; Paladini, Roberta; Noriega-Crespo, Alberto [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); Lagache, Guilaine [Institut d'Astrophysique Spatiale, 91405 Orsay (France); Kawamura, Akiko; Fukui, Yasuo [Department of Astrophysics, Nagoya University, Chikusa-ku, Nagoya 464-8602 (Japan); Onishi, Toshikazu [Department of Physical Science, Osaka Prefecture University, Gakuen 1-1, Sakai, Osaka 599-8531 (Japan)

2011-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "fugitive dust emissions" from the National Library of EnergyBeta (NLEBeta).
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101

Dust Combustion Safety Issues for Fusion Applications  

SciTech Connect

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

102

Pebble Bed Reactor Dust Production Model  

SciTech Connect

The operation of pebble bed reactors, including fuel circulation, can generate graphite dust, which in turn could be a concern for internal components; and to the near field in the remote event of a break in the coolant circuits. The design of the reactor system must, therefore, take the dust into account and the operation must include contingencies for dust removal and for mitigation of potential releases. Such planning requires a proper assessment of the dust inventory. This paper presents a predictive model of dust generation in an operating pebble bed with recirculating fuel. In this preliminary work the production model is based on the use of the assumption of proportionality between the dust production and the normal force and distance traveled. The model developed in this work uses the slip distances and the inter-pebble forces computed by the authors’ PEBBLES. The code, based on the discrete element method, simulates the relevant static and kinetic friction interactions between the pebbles as well as the recirculation of the pebbles through the reactor vessel. The interaction between pebbles and walls of the reactor vat is treated using the same approach. The amount of dust produced is proportional to the wear coefficient for adhesive wear (taken from literature) and to the slip volume, the product of the contact area and the slip distance. The paper will compare the predicted volume with the measured production rates. The simulation tallies the dust production based on the location of creation. Two peak production zones from intra pebble forces are predicted within the bed. The first zone is located near the pebble inlet chute due to the speed of the dropping pebbles. The second peak zone occurs lower in the reactor with increased pebble contact force due to the weight of supported pebbles. This paper presents the first use of a Discrete Element Method simulation of pebble bed dust production.

Abderrafi M. Ougouag; Joshua J. Cogliati

2008-09-01T23:59:59.000Z

103

Dust Acoustic Shock Waves in Adiabatic Hot Dusty Plasmas  

Science Conference Proceedings (OSTI)

It is known that to have a monotonic or oscillatory shock wave a source of dissipation is needed. In this study, we considered the dust charge variation as a source of dissipation. By using the reductive perturbation technique, the nonlinear Burgers equation is derived and the shock-like solution is determined. The effects of dust temperature on different characteristics of dust acoustic shock wave are discussed. It is found out that dust thickness is not affected by dust temperature while for every dusty plasma systems there is dust critical temperature T{sub dc}, for which the dust acoustic shock height will be maximum.

Asgari, H.; Muniandy, S. V.; Wong, C. S. [Plasma Research Laboratory, Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia)

2011-03-30T23:59:59.000Z

104

SPITZER 24 {mu}m SURVEY FOR DUST DISKS AROUND HOT WHITE DWARFS  

Science Conference Proceedings (OSTI)

Two types of dust disks around white dwarfs (WDs) have been reported: small dust disks around cool metal-rich WDs consisting of tidally disrupted asteroids and a large dust disk around the hot central WD of the Helix planetary nebula (PN) possibly produced by collisions among Kuiper-Belt-like objects. To search for more dust disks of the latter type, we have conducted a Spitzer MIPS 24 {mu}m survey of 71 hot WDs or pre-WDs, among which 35 are central stars of PNe (CSPNs). Nine of these evolved stars are detected and their 24 {mu}m flux densities are at least two orders of magnitude higher than their expected photospheric emission. Considering the bias against the detection of distant objects, the 24 {mu}m detection rate for the sample is {approx}>15%. It is striking that seven, or {approx}20%, of the WD and pre-WDs in known PNe exhibit 24 {mu}m excesses, while two, or 5%-6%, of the WDs not in PNe show 24 {mu}m excesses and they have the lowest 24 {mu}m flux densities. We have obtained follow-up Spitzer Infrared Spectrograph spectra for five objects. Four show clear continuum emission at 24 {mu}m, and one is overwhelmed by a bright neighboring star but still shows a hint of continuum emission. In the cases of WD 0950+139 and CSPN K 1-22, a late-type companion is present, making it difficult to determine whether the excess 24 {mu}m emission is associated with the WD or its red companion. High-resolution images in the mid-infrared are needed to establish unambiguously the stars responsible for the 24 {mu}m excesses.

Chu, You-Hua; Bilikova, Jana; Gruendl, Robert A. [Department of Astronomy, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Su, Kate Y. L. [Stewart Observatory, University of Arizona, Tucson, AZ 85721 (United States); De Marco, Orsola [Department of Physics and Astronomy, Macquarie University, Sydney, NSW 2109 (Australia); Guerrero, Martin A. [Instituto de Astrofisica de Andalucia, CSIC, E-18008 Granada (Spain); Updike, Adria C. [CRESST and the Observational Cosmology Laboratory, NASA/GSFC, Greenbelt, MD 20771 (United States); Volk, Kevin [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Rauch, Thomas, E-mail: yhchu@illinois.edu [Institut fuer Astronomie und Astrophysik Tuebingen (IAAT), Abteilung Astronomie, D-72076 Tuebingen (Germany)

2011-09-15T23:59:59.000Z

105

Dust Lofting and Ingestion by Supercell Storms  

Science Conference Proceedings (OSTI)

Recent research pertaining to aerosol impacts on cloud microphysics has shown a need for understanding mineral dust entrainment into moist convection. The goal of this study is to examine the pathways in which nonmicrophysically active mineral ...

Robert B. Seigel; Susan C. van den Heever

2012-05-01T23:59:59.000Z

106

Dust Intrusion Events into the Mediterranean Basin  

Science Conference Proceedings (OSTI)

In this study seven dust intrusion events were identified and analyzed in the central and eastern part of the Mediterranean Sea beginning August 1988 and ending September 1989. In order to locate their sources, characterize their mode, and ...

U. Dayan; J. Heffter; J. Miller; G. Gutman

1991-08-01T23:59:59.000Z

107

He Puff System For Dust Detector Upgrade  

SciTech Connect

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

108

Ice Nuclei in Marine Air: Biogenic Particles or Dust?  

Science Conference Proceedings (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

109

Thermo-Oxidation of Tokamak Carbon Dust  

Science Conference Proceedings (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

110

Dust trajectory sensor: Accuracy and data analysis  

Science Conference Proceedings (OSTI)

The Dust Trajectory Sensor (DTS) instrument is developed for the measurement of the velocity vector of cosmic dust particles. The trajectory information is imperative in determining the particles' origin and distinguishing dust particles from different sources. The velocity vector also reveals information on the history of interaction between the charged dust particle and the magnetospheric or interplanetary space environment. The DTS operational principle is based on measuring the induced charge from the dust on an array of wire electrodes. In recent work, the DTS geometry has been optimized [S. Auer, E. Gruen, S. Kempf, R. Srama, A. Srowig, Z. Sternovsky, and V Tschernjawski, Rev. Sci. Instrum. 79, 084501 (2008)] and a method of triggering was developed [S. Auer, G. Lawrence, E. Gruen, H. Henkel, S. Kempf, R. Srama, and Z. Sternovsky, Nucl. Instrum. Methods Phys. Res. A 622, 74 (2010)]. This article presents the method of analyzing the DTS data and results from a parametric study on the accuracy of the measurements. A laboratory version of the DTS has been constructed and tested with particles in the velocity range of 2-5 km/s using the Heidelberg dust accelerator facility. Both the numerical study and the analyzed experimental data show that the accuracy of the DTS instrument is better than about 1% in velocity and 1 deg. in direction.

Xie, J.; Horanyi, M. [NASA Lunar Science Institute: Colorado Center for Lunar Dust and Atmospheric Studies, and Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80303 (United States); Departments of Physics, University of Colorado, Boulder, Colorado 80309 (United States); Sternovsky, Z. [NASA Lunar Science Institute: Colorado Center for Lunar Dust and Atmospheric Studies, and Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80303 (United States); Department of Aerospace Engineering Sciences, University of Colorado, Boulder, Colorado 80309 (United States); Gruen, E.; Duncan, N.; Drake, K.; Le, H. [NASA Lunar Science Institute: Colorado Center for Lunar Dust and Atmospheric Studies, and Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80303 (United States); Auer, S. [A and M Associates, P. O. Box 421, Basye, Virginia 22810 (United States); Srama, R. [Max-Planck-Institute for Nuclear Physics, Heidelberg 69029 (Germany); Institute of Space Systems, University of Stuttgart, Stuttgart 70569 (Germany)

2011-10-15T23:59:59.000Z

111

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

SciTech Connect

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

112

A characterization of the diffuse Galactic emissions at large angular scales using the Tenerife data  

E-Print Network (OSTI)

The Anomalous microwave emission (AME) has been proved to be an important component of the Galactic diffuse emission in the range from 20 to 60 GHz. To discriminate between different models of AME low frequency microwave data from 10 to 20 GHz are needed. We present here a re-analysis of published and un-published Tenerife data from 10 to 33 GHz at large angular scales (from 5 to 15 degrees). We cross-correlate the Tenerife data to templates of the main Galactic diffuse emissions: synchrotron, free-free and thermal dust. We find evidence of dust correlated emission in the Tenerife data that could be explained as spinning dust grain emission.

Macías-Pérez, J F; Watson, R; Gutierrez, C M; Rebolo, R

2013-01-01T23:59:59.000Z

113

A characterization of the diffuse Galactic emissions in the anti-center of the Galaxy  

E-Print Network (OSTI)

Using the Archeops and WMAP data we perform a study of the anti-center Galactic diffuse emissions - thermal dust, synchrotron, free-free and anomalous emission - at degree scales. The high frequency data are used to infer the thermal dust electromagnetic spectrum and spatial distribution allowing us to precisely subtract this component at lower frequencies. After subtraction of the thermal dust component a mixture of standard synchrotron and free-free emissions does not account for the residuals at these low frequencies. Including the all-sky 408 MHz Haslam data we find evidences for anomalous emission with a spectral index of 2.5 in TRJ units. However, we are not able to conclude regarding the nature of this anomalous emission in this region. For the purpose, data between 408 MHz and 20 GHz covering the same sky region are needed.

Fauvet, L; Hildebrandt, S R; Desert, F -X

2013-01-01T23:59:59.000Z

114

Determining foreground contamination in cosmic microwavebackground observations: Diffuse Galactic emission in the MAXIMA-Ifield  

Science Conference Proceedings (OSTI)

Observations of the cosmic microwave background (CMB) can be contaminated by diffuse foreground emission from sources such as Galactic dust and synchrotron radiation. In these cases, the morphology of the contaminating source is known from observations at different frequencies, but not its amplitude at the frequency of interest for the CMB. We develop a technique for accounting for the effects of such emission in this case, and for simultaneously estimating the foreground amplitude in the CMB observations. We apply the technique to CMB data from the MAXIMA-1 experiment, using maps of Galactic dust emission from combinations of IRAS and DIRBE observations, as well as compilations of Galactic synchrotron emission observations. The spectrum of the dust emission over the 150-450 GHz observed by MAXIMA is consistent with preferred models, but the effect on CMB power spectrum observations is negligible.

Jaffe, A.H.; Balbi, A.; Bond, J.R.; Borrill, J.; Ferreira, P.G.; Finkbeiner, D.; Hanany, S.; Lee, A.T.; Rabii, B.; Richards, P.L.; Smoot,G.F.; Stompor, R.; Winant, C.D.; Wu, J.H.P.

2003-01-05T23:59:59.000Z

115

ON ABSORPTION BY CIRCUMSTELLAR DUST, WITH THE PROGENITOR OF SN 2012aw AS A CASE STUDY  

SciTech Connect

We use the progenitor of SN 2012aw to illustrate the consequences of modeling circumstellar dust using Galactic (interstellar) extinction laws that (1) ignore dust emission in the near-IR and beyond, (2) average over dust compositions, and (3) mischaracterize the optical/UV absorption by assuming that scattered photons are lost to the observer. The primary consequences for the progenitor of SN 2012aw are that both the luminosity and the absorption are significantly overestimated. In particular, the stellar luminosity is most likely in the range 10{sup 4.8} < L {sub *}/L {sub Sun} < 10{sup 5.0} and the star was not extremely massive for a Type IIP progenitor, with M {sub *} < 15 M {sub Sun }. Given the properties of the circumstellar dust and the early X-ray/radio detections of SN 2012aw, the star was probably obscured by an ongoing wind with M-dot {approx}10{sup -5.5} to 10{sup -5.0} M {sub Sun} yr{sup -1} at the time of the explosion, roughly consistent with the expected mass-loss rates for a star of its temperature (T{sub *} {approx_equal} 3600{sup +300} {sub -200} K) and luminosity. In the spirit of Galactic extinction laws, we supply simple interpolation formulae for circumstellar extinction by dusty graphitic and silicate shells as a function of wavelength ({lambda} {>=} 0.3 {mu}m) and total (absorption plus scattering) V-band optical depth ({tau}{sub V} {<=} 20). These do not include the contributions of dust emission, but provide a simple, physical alternative to incorrectly using interstellar extinction laws.

Kochanek, C. S.; Khan, R. [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Dai, X. [Department of Physics and Astronomy, University of Oklahoma, 440 W. Brooks Street, Norman, OK 73019 (United States)

2012-11-01T23:59:59.000Z

116

Dust and ventilation effects on radiant barriers: Cooling season energy measurements  

Science Conference Proceedings (OSTI)

Cooling season tests were conducted in three unoccupied ranch-style houses in Karns, Tennessee, to determine the effects on attic radiant barrier performance incurred by changes in attic ventilation area ratio, attic ventilation type, and the buildup of dust on horizontal radiant barriers. All three houses had R-19 fiberglass batt insulation in their attics. Horizontal radiant barriers were artificially dusted and the dusted barriers showed measurable performance degradations, although the dusted barriers were still superior to no radiant barriers. Dust loadings of 0.34 and 0.74 mg/cm{sup 2} reduced a clean radiant barrier surface emissivity of 0.055 to 0.125 and 0.185, respectively. Total house cooling load increases amounted to 2.3 and 8.4% compared to house loads with clean horizontal barriers, respectively. When compared to R-19 with no horizontal radiant barrier conditions, the dusted horizontal radiant barriers reduced cooling loads by about 7%. Testing showed that increasing the attic ventilation area ratio from the minimum recommended of 1/300 to 1/150 had little if any effect on the house cooling load with either truss or horizontal barriers present in the attics. Radiant barriers, however, still reduced the house cooling load. There was essentially no difference in house cooling load reduction between either ridge/soffit or gable/soffit vent type with a truss radiant barrier, as both reduced cooling loads by about 8% when compared to no radiant barrier conditions. The attic-ventilation-type testing was done with a ventilation area ratio of 1/150.

Levins, W.P.; Karnitz, M.A. (Oak Ridge National Lab., TN (USA)); Hall, J.A. (Tennessee Valley Authority, Knoxville, TN (USA))

1990-05-01T23:59:59.000Z

117

Estimating Environmental Exposures to Indoor Contaminants using Residential-Dust Samples  

E-Print Network (OSTI)

congeners measured in residential-dust samples from selectedcongeners measured in residential-dust samples from selecteda)pyrene measured in residential-dust samples from selected

Whitehead, Todd Patrick

2011-01-01T23:59:59.000Z

118

Numerical Simulation of Dust Lifting within Dust Devils—Simulation of an Intense Vortex  

Science Conference Proceedings (OSTI)

Based on an advanced dust devil–scale large-eddy simulation (LES) model, the atmosphere flow of a modeled dust devil in a quasi–steady state was first simulated to illustrate the characteristics of the gas phase field in the mature stage, ...

Zhaolin Gu; Yongzhi Zhao; Yun Li; Yongzhang Yu; Xiao Feng

2006-10-01T23:59:59.000Z

119

Iron mobilization in North African dust.  

SciTech Connect

Iron is an essential nutrient for phytoplankton. Although iron-containing dust mobilized from arid regions supplies the majority of the iron to the oceans, the key flux in terms of the biogeochemical response to atmospheric deposition is the amount of soluble or bioavailable iron. Atmospheric processing of mineral aerosols by anthropogenic pollutants (e.g. sulfuric acid) may transform insoluble iron into soluble forms. Previous studies have suggested higher iron solubility in smaller particles, as they are subject to more thorough atmospheric processing due to a longer residence time than coarse particles. On the other hand, the specific mineralogy of iron in dust may also influence the particulate iron solubility in size. Compared to mineral dust aerosols, iron from combustion sources could be more soluble, and found more frequently in smaller particles. Internal mixing of alkaline dust with iron-containing minerals could significantly reduce iron dissolution in large dust aerosols due to the buffering effect, which may, in contrast, yield higher solubility in smaller particles externally mixed with alkaline dust (Ito and Feng, 2010). Here, we extend the modeling study of Ito and Feng (2010) to investigate atmospheric processing of mineral aerosols from African dust. In contrast to Asian dust, we used a slower dissolution rate for African dust in the fine mode. We compare simulated fractional iron solubility with observations. The inclusion of alkaline compounds in aqueous chemistry substantially limits the iron dissolution during long-range transport to the Atlantic Ocean: only a small fraction of iron (<0.2%) dissolves from illite in coarsemode dust aerosols with 0.45% soluble iron initially. In contrast, a significant fraction (1-1.5%) dissolves in fine-mode dust aerosols due to the acid mobilization of the iron-containing minerals externally mixed with carbonate minerals. Consequently, the model generally reproduces higher iron solubility in smaller particles as suggested by measurements over the Atlantic Ocean. Our results imply that the dissolution of iron in African dust is generally slower than that in Asian dust. Conventionally, dust is assumed as the major supply of bioavailable iron with a constant solubility at 1-2% to the remote ocean. Therefore, the timing and location of the atmospheric iron input to the ocean with detailed modeling of atmospheric processing could be different from those previously assumed. Past and future changes in aerosol supply of bioavailable iron might play a greater role in the nutrient supply for phytoplankton production in the upper ocean, as global warming has been predicted to intensify stratification and reduce vertical mixing from the deep ocean. Thus the feedback of climate change through ocean uptake of carbon dioxide as well as via aerosol-cloud interaction might be modified by the inclusion of iron chemistry in the atmosphere.

Ito, A.; Feng, Y. (Environmental Science Division); (Research Inst. for Global Change)

2011-01-01T23:59:59.000Z

120

A science based emission factor for particulate matter emitted from cotton harvesting  

E-Print Network (OSTI)

Poor regional air quality in some states across the US cotton belt has resulted in increased pressure on agricultural sources of particulate matter (PM) from air pollution regulators. Moreover, inaccurate emission factors used in the calculation of annual emissions inventories led to the identification of cotton harvesting as a significant source of PM10 in California and Arizona. As a result, cotton growers in these states are now required to obtain air quality permits and submit management practice plans detailing the actions taken by the producer to reduce fugitive PM emissions from field operations. The objective of this work was to develop accurate PM emission factors for cotton harvesting in terms of total suspended particulate (TSP), PM10, and PM2.5. Two protocols were developed and used to develop PM emission factors from cotton harvesting operations on three farms in Texas during 2006 and 2007. Protocol one utilized TSP concentrations measured downwind of harvesting operations with meteorological data measured onsite in a dispersion model to back-calculate TSP emission flux values. Flux values, determined with the regulatory dispersion models ISCST3 and AERMOD, were converted to emission factors and corrected with results from particle size distribution (PSD) analyses to report emission factors in terms of PM10 and PM2.5. Emission factors were developed for two-row (John Deere 9910) and sixrow (John Deere 9996) cotton pickers with protocol one. The uncertainty associated with the emission factors developed through protocol one resulted in no significant difference between the emission factors for the two machines. Under the second protocol, emission concentrations were measured onboard the six-row cotton picker as the machine harvested cotton. PM10 and PM2.5 emission factors were developed from TSP emission concentration measurements converted to emission rates using the results of PSD analysis. The total TSP, PM10, and PM2.5 emission factors resulting from the source measurement protocol are 1.64 ± 0.37, 0.55 ± 0.12, and 1.58E- 03 ± 4.5E-04 kg/ha, respectively. These emission factors contain the lowest uncertainty and highest level of precision of any cotton harvesting PM emission factors ever developed. Thus, the emission factors developed through the source sampling protocol are recommended for regulatory use.

Wanjura, John David

2008-05-01T23:59:59.000Z

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.
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to obtain the most current and comprehensive results.


121

Propagation of nonlinear dust magnetoacoustic waves in cylindrical geometry  

SciTech Connect

The cylindrical dust magnetoacoustic shocks in dissipative and solitons in non-dissipative dust-ion plasmas are studied. The dust particles are assumed to be fully negatively charged so that the density of electrons in comparison with dust and ions is negligible. The cylindrical Korteweg-de Vries Burgers and cylindrical Korteweg-de Vries equations are derived for dust magnetosonic waves by employing the reductive perturbation method. It is found that dust plasma parameters such as dust charge number, dust density, and ion temperature have strong influence on the profile of dust magnetoacoustic shocks and solitons. The results are also obtained numerically by using the data from laboratory experiments on dusty plasmas.

Hussain, S.; Mahmood, S. [Theoretical Plasma Physics Division (TPPD), PINSTECH, P.O. Nilore, Islamabad 44000 (Pakistan) and Department of Physics and Applied Physics (DPAM), PIEAS, P.O. Nilore, Islamabad 44000 (Pakistan)

2011-12-15T23:59:59.000Z

122

INTERPRETATION OF (596) SCHEILA'S TRIPLE DUST TAILS  

Science Conference Proceedings (OSTI)

Strange-looking dust cloud around asteroid (596) Scheila was discovered on 2010 December 11.44-11.47. Unlike normal cometary tails, it consisted of three tails and faded within two months. We constructed a model to reproduce the morphology of the dust cloud based on the laboratory measurement of high-velocity impacts and the dust dynamics. As a result, we succeeded in reproducing the peculiar dust cloud by an impact-driven ejecta plume consisting of an impact cone and downrange plume. Assuming an impact angle of 45 Degree-Sign , our model suggests that a decameter-sized asteroid collided with (596) Scheila from the direction of ({alpha}{sub im}, {delta}{sub im}) = (60 Degree-Sign , -40 Degree-Sign ) in J2000 coordinates on 2010 December 3. The maximum ejection velocity of the dust particles exceeded 100 m s{sup -1}. Our results suggest that the surface of (596) Scheila consists of materials with low tensile strength.

Ishiguro, Masateru [Department of Physics and Astronomy, Seoul National University, Gwanak, Seoul 151-742 (Korea, Republic of); Hanayama, Hidekazu; Watanabe, Jun-ichi; Miyaji, Takeshi; Fukushima, Hideo [Ishigakijima Astronomical Observatory, National Astronomical Observatory of Japan, Ishigaki, Okinawa 907-0024 (Japan); Hasegawa, Sunao; Sarugaku, Yuki [Institute of Space and Astronautical Science (ISAS), JAXA, Sagamihara, Kanagawa 252-5210 (Japan); Fujiwara, Hideaki; Terada, Hiroshi [Subaru Telescope, National Astronomical Observatory of Japan, Hilo, HI 96720 (United States); Hsieh, Henry H. [Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States); Vaubaillon, Jeremie J. [Observatoire de Paris, I.M.C.C.E., Denfert Rochereau, Bat. A., FR-75014 Paris (France); Kawai, Nobuyuki [Department of Physics, Tokyo Institute of Technology, Meguro, Tokyo 152-8551 (Japan); Yanagisawa, Kenshi; Kuroda, Daisuke [Okayama Astrophysical Observatory, National Astronomical Observatory of Japan, Asaguchi, Okayama 719-0232 (Japan); Ohta, Kouji [Department of Astronomy, Kyoto University, Sakyo, Kyoto 606-8502 (Japan); Hamanowa, Hiromi [Hamanowa Astronomical Observatory, Motomiya, Fukushima 969-1204 (Japan); Kim, Junhan [Yangcheon-gu, Seoul (Korea, Republic of); Pyo, Jeonghyun [Korea Astronomy and Space Science Institute (KASI), Daejeon 305-348 (Korea, Republic of); Nakamura, Akiko M., E-mail: ishiguro@snu.ac.kr [Department of Earth and Planetary Sciences, Kobe University, Nada, Kobe 657-8501 (Japan)

2011-11-15T23:59:59.000Z

123

Dust Studies in DIII-D and TEXTOR  

SciTech Connect

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

124

Misers gold dust collection and cloud characterization  

SciTech Connect

MISERS GOLD was a surface detonation of 2445 tons of ammonium nitrate-fuel oil blasting agent conducted by the Defense Nuclear Agency for a variety of research purposes. This report presents the results of an experiment designed to study the dust cloud over the 24-hour period following the detonation. The cloud was sampled by aircraft to obtain material needed to characterize the quantity of dust lofted, the source regions of the cloud, and the size, shape, and mineralogical characteristics of the particles. Elemental tracers and organic dyes were emplaced in the charge and in surrounding areas. Analyses were done by instrumental neutron activation analysis (INAA), fluorimetry, scanning electron microscopy (SEM), and energy-dispersive spectrometry (EDS). Tracer data define the source regions of the dust cloud. Extensive particle size distribution data were obtained. 12 figs.

Mason, A.S.; Finnegan, D.L.; Bayhurst, G.K.; Raymond, R. Jr.; Hagan, R.C.; Luedemann, G.; Wohletz, K.H.

1991-01-01T23:59:59.000Z

125

Impact of Transport Schemes on Modeled Dust Concentrations  

Science Conference Proceedings (OSTI)

A sensitivity study is performed with the CHIMERE-DUST chemistry transport model in order to evaluate the modeled mineral dust spread due to the horizontal transport scheme accuracy. Three different schemes are implemented in the model: the ...

Maria Raffaella Vuolo; Laurent Menut; Hélène Chepfer

2009-06-01T23:59:59.000Z

126

Historical Records of Asian Dust Events (Hwangsa) in Korea  

Science Conference Proceedings (OSTI)

The observation of dust events in Korea must have been important through its long history because of its geographical and meteorological setting. Descriptions about dust events were well documented in historical archives, such as Samguk sagi (57 ...

Youngsin Chun; Hi-Ku Cho; Hyo-Sang Chung; Meehye Lee

2008-06-01T23:59:59.000Z

127

Microsoft Word - Natural Gas JIM REVISED 7-21-04pm#.doc  

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

new technologies that reduce or eliminate fugitive emissions, and minimize environmental impacts resulting from construction activities. Increase the efficiency of...

128

Draft Environmental Impact Statement for the Site Selection for the Expansion of the Strategic Petroleum Reserve  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

2 2 Appendices A - M May 2006 Appendix A Air Quality [This page intentionally left blank] Appendix A: Air Quality A-i Table of Contents Page A.1 SITE PREPARATION AND CONSTRUCTION ....................................................................A-1 A.2 OFF-ROAD EQUIPMENT EMISSIONS.................................................................................A-1 A.3 ON-ROAD UTILITY TRUCKS ................................................................................................A-2 A.4 FUGITIVE DUST .......................................................................................................................A-2 A.5 SITE DEVELOPMENT .............................................................................................................A-3

129

Effects of plasma particle trapping on dust-acoustic solitary waves in an opposite polarity dust-plasma medium  

SciTech Connect

Dust acoustic solitary waves in a dusty plasma containing dust of opposite polarity (adiabatic positive and negative dust), non-isothermal electrons and ions (following vortex like distribution) are theoretically investigated by employing pseudo-potential approach, which is valid for arbitrary amplitude structures. The propagation of small but finite amplitude solitary structures is also examined by using the reductive perturbation method. The basic properties of large (small) amplitude solitary structures are investigated by analyzing the energy integral (modified Korteweg-de Vries equation). It is shown that the effects of dust polarity, trapping of plasma particles (electrons and ions), and temperatures of dust fluids significantly modify the basic features of the dust-acoustic solitary structures that are found to exist in such an opposite polarity dust-plasma medium. The relevance of the work in opposite polarity dust-plasma, which may occur in cometary tails, upper mesosphere, Jupiter's magnetosphere, is briefly discussed.

Ahmad, Zulfiqar [Institute of Physics and Electronics, University of Peshawar, 25000 Peshawar (Pakistan); Mushtaq, A. [Department of Physics, Abdul Wali Khan University, Mardan 23200 (Pakistan); National Center for Physics, Shahdrah Valley Road, Islamabad 44000 (Pakistan); Mamun, A. A. [Department of Physics, Jahangirnagar University Savar, Dhaka 1342 (Bangladesh)

2013-03-15T23:59:59.000Z

130

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

E-Print Network (OSTI)

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

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

2009-01-01T23:59:59.000Z

131

Dust Mitigation Methods for Coal Combustion Products  

Science Conference Proceedings (OSTI)

Coal-fired power plants generate coal combustion products (CCPs) requiring management for storage and disposal. These products are often stored in facilities such as landfills or placed in temporary storage pads for short or long durations. At these facilities, there is a need to address dust mitigation concerns in order to comply with environmental permits, ...

2013-08-27T23:59:59.000Z

132

A Model for Saharan Dust Transport  

Science Conference Proceedings (OSTI)

In this paper the source strength and the deposition rate of the dust emerging from the Sahara are assessed. For this purpose a multichannel sunphotometer has been developed and a turbidity network covering 11 stations has been set up in the ...

Guillaume A. d'Almeida

1986-07-01T23:59:59.000Z

133

Radiative Heating Rates for Saharan Dust  

Science Conference Proceedings (OSTI)

A combined longwave and shortwave radiative transfer model was used to determine effects of Saharan dust on the radiative fluxes and heating/cooling rates in the atmosphere. Cases are treated for cloud-free and overcast conditions over the ocean ...

Toby N. Carlson; Stanley G. Benjamin

1980-01-01T23:59:59.000Z

134

The Dust Accelerator Facility of the Colorado Center for Lunar Dust and Atmospheric Studies  

Science Conference Proceedings (OSTI)

The NASA Lunar Institute's Colorado Center for Lunar Dust and Atmospheric Studies has recently completed the construction of a new experimental facility to study hypervelocity dust impacts. The installation includes a 3 MV Pelletron, accelerating small particles in the size range of 0.1 to few microns to velocities in the range of 1 to 100 km/s. Here we report the capabilities of our facility, and the results of our first experiments.

Horanyi, M.; Colette, A.; Drake, K.; Gruen, E.; Kempf, S.; Munsat, T.; Robertson, S.; Shu, A.; Sternovsky, Z.; Wang, X. [NASA Lunar Science Institute Colorado Center for Lunar Dust and Atmospheric Studies University of Colorado, Boulder, CO, 80309 (United States)

2011-11-29T23:59:59.000Z

135

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

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

136

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

Science Conference Proceedings (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

137

U.S. zero emission coal alliance techology  

DOE Green Energy (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

138

Milky Way Tomography IV: Dissecting Dust  

SciTech Connect

We use SDSS photometry of 73 million stars to simultaneously obtain best-fit main-sequence stellar energy distribution (SED) and amount of dust extinction along the line of sight towards each star. Using a subsample of 23 million stars with 2MASS photometry, whose addition enables more robust results, we show that SDSS photometry alone is sufficient to break degeneracies between intrinsic stellar color and dust amount when the shape of extinction curve is fixed. When using both SDSS and 2MASS photometry, the ratio of the total to selective absorption, R{sub V}, can be determined with an uncertainty of about 0.1 for most stars in high-extinction regions. These fits enable detailed studies of the dust properties and its spatial distribution, and of the stellar spatial distribution at low Galactic latitudes (|b| < 30{sup o}). Our results are in good agreement with the extinction normalization given by the Schlegel et al. (1998, SFD) dust maps at high northern Galactic latitudes, but indicate that the SFD extinction map appears to be consistently overestimated by about 20% in the southern sky, in agreement with recent study by Schlafly et al. (2010). The constraints on the shape of the dust extinction curve across the SDSS and 2MASS bandpasses disfavor the reddening law of O'Donnell (1994), but support the models by Fitzpatrick (1999) and Cardelli et al. (1989). For the latter, we find a ratio of the total to selective absorption to be R{sub V} = 3.0 {+-} 0.1(random) {+-} 0.1 (systematic) over most of the high-latitude sky. At low Galactic latitudes (|b| < 5{sup o}), we demonstrate that the SFD map cannot be reliably used to correct for extinction because most stars are embedded in dust, rather than behind it, as is the case at high Galactic latitudes. We analyze three-dimensional maps of the best-fit R{sub V} and find that R{sub V} = 3.1 cannot be ruled out in any of the ten SEGUE stripes at a precision level of {approx} 0.1 - 0.2. Our best estimate for the intrinsic scatter of R{sub V} in the regions probed by SEGUE stripes is {approx} 0.2. We introduce a method for efficient selection of candidate red giant stars in the disk, dubbed 'dusty parallax relation', which utilizes a correlation between distance and the extinction along the line of sight. We make these best-fit parameters, as well as all the input SDSS and 2MASS data, publicly available in a user-friendly format. These data can be used for studies of stellar number density distribution, the distribution of dust properties, for selecting sources whose SED differs from SEDs for high-latitude main sequence stars, and for estimating distances to dust clouds and, in turn, to molecular gas clouds.

Berry, Michael; /Washington U., Seattle, Astron. Dept. /Rutgers U., Piscataway; Ivezic, Zeljko; /Washington U., Seattle, Astron. Dept.; Sesar, Branimir; /Caltech; Juric, Mario; /Harvard U., Phys. Dept.; Schlafly, Edward F.; /Harvard-Smithsonian Ctr. Astrophys.; Bellovary, Jillian; /Michigan U.; Finkbeiner, Douglas; /Harvard-Smithsonian Ctr. Astrophys.; Vrbanec, Dijana; /Zagreb U.; Beers, Timothy C.; /Natl. Solar Observ., Tucson; Brooks, Keira J.; /Washington U., Seattle, Astron. Dept.; Schneider, Donald P.; /Penn State U. /Washington U., Seattle, Astron. Dept.

2011-11-01T23:59:59.000Z

139

The Dust Tail of Asteroid (3200) Phaethon  

E-Print Network (OSTI)

We report the discovery of a comet-like tail on asteroid (3200) Phaethon when imaged at optical wavelengths near perihelion. In both 2009 and 2012, the tail appears >=350" (2.5x10^8 m) in length and extends approximately in the projected anti-solar direction. We interpret the tail as being caused by dust particles accelerated by solar radiation pressure. The sudden appearance and the morphology of the tail indicate that the dust particles are small, with an effective radius ~1 micrometer and a combined mass ~3x10^5 kg. These particles are likely products of thermal fracture and/or desiccation cracking under the very high surface temperatures (~1000 K) experienced by Phaethon at perihelion. The existence of the tail confirms earlier inferences about activity in this body based on the detection of anomalous brightening. Phaethon, the presumed source of the Geminid meteoroids, is still active.

Jewitt, David; Agarwal, Jessica

2013-01-01T23:59:59.000Z

140

Lunar dust transport and potential interactions with power system components  

DOE Green Energy (OSTI)

The lunar surface is covered by a thick blanket of fine dust. This dust may be readily suspended from the surface and transported by a variety of mechanisms. As a consequence, lunar dust can accumulate on sensitive power components, such as photovoltaic arrays and radiator surfaces, reducing their performance. In addition to natural mechanisms, human activities on the Moon will disturb significant amounts of lunar dust. Of all the mechanisms identified, the most serious is rocket launch and landing. The return of components from the Surveyor III provided a rare opportunity to observe the effects of the nearby landing of the Apollo 12 lunar module. The evidence proved that significant dust accumulation occurred on the Surveyor at a distance of 155 m. From available information on particle suspension and transport mechanisms, a series of models was developed to predict dust accumulation as a function of distance from the lunar module. The accumulation distribution was extrapolated to a future lunar lander scenario. These models indicate that accumulation is expected to be substantial even as far as 2 km from the landing site. Estimates of the performance penalties associated with lunar dust coverage on radiators and photovoltaic arrays are presented. Because of the lunar dust adhesive and cohesive properties, the most practical dust defensive strategy appears to be the protection of sensitive components from the arrival of lunar dust by location, orientation, or barriers.

Katzan, C.M.; Edwards, J.L.

1991-11-01T23:59:59.000Z

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.


141

ALPHA ATTENUATION DUE TO DUST LOADING  

SciTech Connect

Previous studies had been done in order to show the attenuation of alpha particles in filter media. These studies provided an accurate correction for this attenuation, but there had not yet been a study with sufficient results to properly correct for attenuation due to dust loading on the filters. At the Savannah River Site, filter samples are corrected for attenuation due to dust loading at 20%. Depending on the facility the filter comes from and the duration of the sampling period, the proper correction factor may vary. The objective of this study was to determine self-absorption curves for each of three counting instruments. Prior work indicated significant decreases in alpha count rate (as much as 38%) due to dust loading, especially on filters from facilities where sampling takes place over long intervals. The alpha count rate decreased because of a decrease in the energy of the alpha. The study performed resulted in a set of alpha absorption curves for each of three detectors. This study also took into account the affects of the geometry differences in the different counting equipment used.

Dailey, A; Dennis Hadlock, D

2007-08-09T23:59:59.000Z

142

Carbon dioxide sequestration in cement kiln dust through mineral carbonation  

Science Conference Proceedings (OSTI)

Carbon sequestration through the formation of carbonates is a potential means to reduce CO{sub 2} emissions. Alkaline industrial solid wastes typically have high mass fractions of reactive oxides that may not require preprocessing, making them an attractive source material for mineral carbonation. The degree of mineral carbonation achievable in cement kiln dust (CKD) under ambient temperatures and pressures was examined through a series of batch and column experiments. The overall extent and potential mechanisms and rate behavior of the carbonation process were assessed through a complementary set of analytical and empirical methods, including mass change, thermal analysis, and X-ray diffraction. The carbonation reactions were carried out primarily through the reaction of CO{sub 2} with Ca(OH){sub 2}, and CaCO{sub 3} was observed as the predominant carbonation product. A sequestration extent of over 60% was observed within 8 h of reaction without any modifications to the waste. Sequestration appears to follow unreacted core model theory where reaction kinetics are controlled by a first-order rate constant at early times; however, as carbonation progresses, the kinetics of the reaction are attenuated by the extent of the reaction due to diffusion control, with the extent of conversion never reaching completion. 35 refs., 3 figs., 1 tab.

Deborah N. Huntzinger; John S. Gierke; S. Komar Kawatra; Timothy C. Eisele; Lawrence L. Sutter [University of Michigan, Ann Arbor, MI (United States). Department of Civil and Environmental Engineering

2009-03-15T23:59:59.000Z

143

Spatial distribution of the interplanetary dust deduced by infrared observations  

Science Conference Proceedings (OSTI)

IR observations of the interplanetary dust performed by the ZIP rocket experiment are analyzed, focusing on the effect of experimental errors on the inversion procedure previously used to obtain the spatial distribution of the dust. Numerical simulation shows that the experimental errors are too large to reveal deviations of the dust density from a simple power-law radial distribution. The accuracy which would be required in future experiments is estimated. 9 refs.

De Bernardis, P.; Feminella, F.; Moreno, G. (Roma I Universita, Rome (Italy))

1991-03-01T23:59:59.000Z

144

Radiative Forcing of Climate By Ice-Age Atmospheric Dust  

E-Print Network (OSTI)

During glacial periods, dust deposition rates and inferred atmospheric concentrations were globally much higher than present. According to recent model results, the large enhancement of atmospheric dust content at the last glacial maximum (LGM) can be explained only if increases in the potential dust source areas are taken into account. Such increases are to be expected, due to e#ects of low precipitation and low atmospheric (CO 2 ) on plant growth. Here the modelled three-dimensional dust fields from Mahowald et al. and modelled seasonally varying surface-albedo fields derived in a parallel manner, are used to quantify the mean radiative forcing due to modern (non-anthropogenic) and LGM dust. The e#ect of mineralogical provenance on the radiative properties of the dust is taken into account, as is the range of optical properties associated with uncertainties about the mixing state of the dust particles. The high-latitude (poleward of 45#) mean change in forcing (LGM minus modern) is estimated to be small (--0.9 to +0.2 W m ), especially when compared to nearly --20 W m due to reflection from the extended ice sheets. Although the net e#ect of dust over ice sheets is a positive forcing (warming), much of the simulated high-latitude dust was not over the ice sheets, but over unglaciated regions close to the expanded dust source region in central Asia. In the tropics the change in forcing is estimated to be overall negative, and of similarly large magnitude (--2.2 to --3.2 W m ) to the radiative cooling e#ect of low atmospheric (CO 2 ). Thus, the largest long-term climatic e#ect of the LGM dust is likely to have been a cooling of the tropics. Low tropical sea-surface temperatures, low atmospheric (CO 2 ) and high atmospheric dust loading may be mutually reinforcin...

T. Claquin; C. Roelandt; K.E. Kohfeld; S.P. Harrison; I. Tegen; I.C. Prentice; Y. Balkanski; Prentice Æ Y. Balkanski; G. Bergametti; Æ N. Mahowald; Æ M. Schulz; M. Schulz; Æ K. E. Kohfeld; Æ K. E. Kohfeld; C. Roelandt; C. Roelandt; Æ S. P. Harrison; Æ S. P. Harrison; Æ S. P. Harrison; G. Bergametti; H. Rodhe; Æ H. Rodhe; M. Hansson; M. Hansson; N. Mahowald; N. Mahowald

2003-01-01T23:59:59.000Z

145

Dust acoustic shock waves in two temperatures charged dusty grains  

Science Conference Proceedings (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

146

AN INTERMEDIATE LUMINOSITY TRANSIENT IN NGC 300: THE ERUPTION OF A DUST-ENSHROUDED MASSIVE STAR  

SciTech Connect

We present multi-epoch high-resolution optical spectroscopy, UV/radio/X-ray imaging, and archival Hubble and Spitzer observations of an intermediate luminosity optical transient recently discovered in the nearby galaxy NGC 300. We find that the transient (NGC 300 OT2008-1) has a peak absolute magnitude of M{sub bol} {approx} -11.8 mag, intermediate between novae and supernovae, and similar to the recent events M85 OT2006-1 and SN 2008S. Our high-resolution spectra, the first for this event, are dominated by intermediate velocity ({approx}200-1000 km s{sup -1}) hydrogen Balmer lines and Ca II emission and absorption lines that point to a complex circumstellar environment, reminiscent of the yellow hypergiant IRC+10420. In particular, we detect asymmetric Ca II H and K absorption with a broad red wing extending to {approx}10{sup 3} km s{sup -1}, indicative of gas inflow at high velocity (possibly the wind of a massive binary companion). The low luminosity, intermediate velocities, and overall similarity to a known eruptive star indicate that the event did not result in a complete disruption of the progenitor. We identify the progenitor in archival Spitzer observations, with deep upper limits from Hubble data. The spectral energy distribution points to a dust-enshrouded star with a luminosity of about 6 x 10{sup 4} L{sub sun}, indicative of a {approx}10-20 M{sub sun} progenitor (or binary system). This conclusion is in good agreement with our interpretation of the outburst and circumstellar properties. The lack of significant extinction in the transient spectrum indicates that the dust surrounding the progenitor was cleared by the outburst. We thus predict that the progenitor should be eventually visible with Hubble if the transient event marks an evolutionary transition to a dust-free state, or with Spitzer if the event marks a cyclical process of dust formation.

Berger, E.; Soderberg, A. M.; Foley, R. J.; Dupree, A. K. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Chevalier, R. A. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States); Fransson, C. [Department of Astronomy, Stockholm University, AlbaNova, SE-106 91 Stockholm (Sweden); Leonard, D. C. [Department of Astronomy, San Diego State University, PA-210, 5500 Campanile Drive, San Diego, CA 92182-1221 (United States); Debes, J. H. [Carnegie Institution of Washington, Department of Terrestrial Magnetism, 5241 Broad Branch Road, Washington, DC 20015 (United States); Diamond-Stanic, A. M.; Tremonti, C. A. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Ivans, I. I.; Thompson, I. B. [Observatories of the Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Simmerer, J. [Lund Observatory, Box 43, SE-221 00 Lund (Sweden)

2009-07-10T23:59:59.000Z

147

SPITZER AND HERSCHEL MULTIWAVELENGTH CHARACTERIZATION OF THE DUST CONTENT OF EVOLVED H II REGIONS  

SciTech Connect

We have analyzed a uniform sample of 16 evolved H II regions located in a 2 Degree-Sign Multiplication-Sign 2 Degree-Sign Galactic field centered at (l,b) = (30 Degree-Sign , 0 Degree-Sign ) and observed as part of the Herschel Hi-GAL survey. The evolutionary stage of these H II regions was established using ancillary radio-continuum data. By combining Hi-GAL PACS (70 {mu}m, 160 {mu}m) and SPIRE (250 {mu}m, 350 {mu}m, and 500 {mu}m) measurements with MIPSGAL 24 {mu}m data, we built spectral energy distributions of the sources and showed that a two-component gray-body model is a good representation of the data. In particular, wavelengths >70 {mu}m appear to trace a cold dust component, for which we estimated an equilibrium temperature of the big grains (BGs) in the range 20-30 K, while for {lambda} < 70 {mu}m, the data indicate the presence of a warm dust component at temperatures of the order of 50-90 K. This analysis also revealed that dust is present in the interior of H II regions, although likely not in a large amount. In addition, the data seem to corroborate the hypothesis that the main mechanism responsible for the (partial) depletion of dust in H II regions is radiation-pressure-driven drift. In this framework, we speculated that the 24 {mu}m emission that spatially correlates with ionized gas might be associated with either very small grain or BG replenishment, as recently proposed for the case of wind-blown bubbles. Finally, we found that evolved H II regions are characterized by distinctive far-IR and submillimeter colors, which can be used as diagnostics for their identification in unresolved Galactic and extragalactic regions.

Paladini, R. [NASA Herschel Science Center, California Institute of Technology, 1200, East California Boulevard, Pasadena, CA 91125 (United States); Umana, G. [INAF-Osservatorio Astrofisico di Catania, Via S. Sofia 78, I-95123 Catania (Italy); Veneziani, M.; Noriega-Crespo, A. [Infrared Processing and Analysis Center, California Institute of Technology, 1200, East California Boulevard, Pasadena, CA 91125 (United States); Anderson, L. D. [Department of Physics, West Virginia University, Morgantown, WV 26506 (United States); Piacentini, F. [Dipartimento di Fisica, Universita di Roma La Sapienza, I-00185 Roma (Italy); Pinheiro Goncalves, D. [Department of Astronomy and Astrophysics, University of Toronto 50 George Street, Toronto, ON M5S 3H4 (Canada); Paradis, D.; Bernard, J.-P. [Centre d'Etude Spatiale des Rayonnements, 9 Avenue du Colonel Roche, F-31028 Toulouse Cedex 4 (France); Tibbs, C. T. [Spitzer Science Center, California Institute of Technology, 1200, East California Boulevard, Pasadena, CA 91125 (United States); Natoli, P., E-mail: paladini@ipac.caltech.edu [Istituto Nazionale di Fisica Nucleare, Sezione Ferrara, I-44100 Ferrara (Italy)

2012-12-01T23:59:59.000Z

148

Recovering Zinc and Lead from Electric Arc Furnace Dust  

Science Conference Proceedings (OSTI)

Aug 1, 2000 ... Non-member price: 25.00. TMS Student Member price: 10.00. Product In Stock. Description Increasing amounts of electric arc furnace dust ...

149

Dust-induced instability in a rotating plasma  

SciTech Connect

The effect of immobile dust on stability of a magnetized rotating plasma is analyzed. In the presence of dust, a term containing an electric field appears in the one-fluid equation of plasma motion. This electric field leads to an instability of the magnetized rotating plasma called the dust-induced rotational instability (DRI). The DRI is related to the charge imbalance between plasma ions and electrons introduced by the presence of charged dust. In contrast to the well-known magnetorotational instability requiring the decreasing radial profile of the plasma rotation frequency, the DRI can appear for an increasing rotation frequency profile.

Mikhailovskii, A. B.; Vladimirov, S. V.; Lominadze, J. G.; Tsypin, V. S.; Churikov, A. P.; Erokhin, N. N.; Galvao, R. M. O. [Institute of Nuclear Fusion, Russian Research Centre Kurchatov Institute, 1, Kurchatov Sq., Moscow 123182 (Russian Federation); School of Physics, University of Sydney, Sydney, N.S.W. 2006 (Australia); Kharadze Abastumani National Astrophysical Observatory, 2a, Kazbegi Ave., Tbilisi 0160 (Georgia); Brazilian Center for Physics Research, Rua Xavier Sigaud, 150, 22290-180, Rio de Janeiro (Brazil); Syzran Branch of Samara Technical University, 45, Sovetskaya Str., Syzran, Samara Region 446001 (Russian Federation); Institute of Nuclear Fusion, Russian Research Centre Kurchatov Institute, 1, Kurchatov Sq., Moscow 123182 (Russian Federation); Physics Institute, University of Sao Paulo, Cidade Universitaria, 05508-900, Sao Paulo, Brazil and Brazilian Center for Physics Research, Rua Xavier Sigaud, 150, 22290-180, Rio de Janeiro (Brazil)

2008-01-15T23:59:59.000Z

150

ESP Dust Recovery Process Test Works, Plant Trial, Commissioning ...  

Science Conference Proceedings (OSTI)

Most of the volatile arsenic will report to Isasmelt Electrostatic Precipitator (ESP) or Waste Heat Boiler dusts where it will form a re-circulating load within the ...

151

Heterogeneous Reactions on Mineral Dust: Surface Reactions of...  

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Reactions on Mineral Dust: Surface Reactions of Sulfur Dioxide, Ozone, Nitric and Acetic Acid on Oxide and Carbonate Particles Speaker(s): Vicki Grassian Date: June 14,...

152

Applications of high-speed dust injection to magnetic fusion  

Science Conference Proceedings (OSTI)

It is now an established fact that a significant amount of dust is produced in magnetic fusion devices due to plasma-wall interactions. Dust inventory must be controlled, in particular for the next-generation steady-state fusion machines like ITER, as it can pose significant safety hazards and degrade performance. Safety concerns are due to tritium retention, dust radioactivity, toxicity, and flammability. Performance concerns include high-Z impurities carried by dust to the fusion core that can reduce plasma temperature and may even induce sudden termination of the plasma. We have recognized that dust transport, dust-plasma interactions in magnetic fusion devices can be effectively studied experimentally by injection of dust with known properties into fusion plasmas. Other applications of injected dust include diagnosis of fusion plasmas and edge localized mode (ELM)'s pacing. In diagnostic applications, dust can be regarded as a source of transient neutrals before complete ionization. ELM's pacing is a promising scheme to prevent disruptions and type I ELM's that can cause catastrophic damage to fusion machines. Different implementation schemes are available depending on applications of dust injection. One of the simplest dust injection schemes is through gravitational acceleration of dust in vacuum. Experiments at Los Alamos and Princeton will be described, both of which use piezoelectric shakers to deliver dust to plasma. In Princeton experiments, spherical particles (40 micron) have been dropped in a systematic and reproducible manner using a computer-controlled piezoelectric bending actuator operating at an acoustic (0,2) resonance. The circular actuator was constructed with a 2.5 mm diameter central hole. At resonance ({approx} 2 kHz) an applied sinusoidal voltage has been used to control the flux of particles exiting the hole. A simple screw throttle located {approx}1mm above the hole has been used to set the magnitude of the flux achieved for a given voltage. Particle fluxes ranging from a few tens of particle per second up to thousands of particles per second have been achieved using this simple device. To achieve higher dust injection speed, another key consideration is how to accelerate dust at controlled amount. In addition to gravity, other possible acceleration mechanisms include electrostatic, electromagnetic, gas-dragged, plasma-dragged, and laser-ablation-based acceleration. Features and limitations of the different acceleration methods will be discussed. We will also describe laboratory experiments on dust acceleration.

Wang, Zhehui [Los Alamos National Laboratory; Li, Yangfang [Max Planck Institute for Extraterrestrial Physics, Germany

2012-08-08T23:59:59.000Z

153

Dust in the Indoor Environment: Physical and Chemical Changes...  

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Hottinger said: "Settled dust on hot surfaces above 70 degrees Celsius results in distillation products having irritating effect on mucous membranes, fairly equal to the effect...

154

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

155

Cooling flows, central galaxy--cluster alignments, X-ray absorption and dust  

E-Print Network (OSTI)

We present the analysis of pointed ROSAT PSPC observations of five of the most luminous, intermediate redshift ($0.1 cooling flows. The alignment between CCGs and their host clusters has been investigated. For those clusters with cooling flows, the position angles of the X-ray emission from the clusters and the optical emission from the CCGs agrees within 5 degrees. For the one probable non-cooling flow cluster in the sample, Abell 2208, the alignment is significantly poorer. We examine the evidence for intrinsic X-ray absorption in the clusters. The X-ray spectra for Abell 1068 and Abell 1664 show that the cooling flows in these clusters are intrinsically absorbed by equivalent hydrogen column densities $\\geq 10^{21} atom cm$^{-2}$. The optical spectra of the CCGs in these clusters exhibit substantial intrinsic reddening, at levels consistent with the X-ray absorption results if standard dust to gas ratios are assumed.

S. W. Allen; A. C. Fabian; A. C. Edge; H. Bohringer; D. A. White

1995-03-28T23:59:59.000Z

156

HFC Emissions Estinating  

Science Conference Proceedings (OSTI)

... Dioxide Emissions Reporting Year: January – December, 200x Agent Type GWP Total Emission by Agent Type, kg Equivalent CO2 Emission by ...

2011-10-13T23:59:59.000Z

157

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

158

CO2 Emissions - Gibraltar  

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Gibraltar CO2 Emissions from Gibraltar Data graphic Data CO2 Emissions from Gibraltar image Per capita CO2 Emission Estimates for Gibraltar...

159

CO2 Emissions - Mozambique  

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Mozambique Graphics CO2 Emissions from Mozambique Data graphic Data CO2 Emissions from Mozambique image Per capita CO2 Emission Estimates for Mozambique...

160

CO2 Emissions - Macau  

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Far East Macau CO2 Emissions from Macau Data graphic Data CO2 Emissions from Macau image Per capita CO2 Emission Estimates for Macau...

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161

CO2 Emissions - Guadeloupe  

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162

CO2 Emissions - Ghana  

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Africa Ghana Graphics CO2 Emissions from Ghana Data graphic Data CO2 Emissions from Ghana image Per capita CO2 Emission Estimates for Ghana...

163

CO2 Emissions - Ireland  

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Ireland CO2 Emissions from Ireland Data graphic Data CO2 Emissions from Ireland image Per capita CO2 Emission Estimates for Ireland...

164

CO2 Emissions - Malta  

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Western Europe Malta CO2 Emissions from Malta Data graphic Data CO2 Emissions from Malta image Per capita CO2 Emission Estimates for Malta...

165

CO2 Emissions - Kyrgyzstan  

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Centrally Planned Europe Kyrgyzstan CO2 Emissions from Kyrgyzstan Data graphic Data CO2 Emissions from Kyrgyzstan image Per capita CO2 Emission Estimates for Kyrgyzstan...

166

CO2 Emissions - Mali  

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167

CO2 Emissions - Portugal  

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168

CO2 Emissions - Paraguay  

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Paraguay Graphics CO2 Emissions from Paraguay Data graphic Data CO2 Emissions from Paraguay image Per capita CO2 Emission Estimates for Paraguay...

169

CO2 Emissions - Macedonia  

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Western Europe Macedonia CO2 Emissions from Macedonia Data graphic Data CO2 Emissions from Macedonia image Per capita CO2 Emission Estimates for Macedonia...

170

CO2 Emissions - Malawi  

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171

CO2 Emissions - Gabon  

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Africa Gabon Graphics CO2 Emissions from Gabon Data graphic Data CO2 Emissions from Gabon image Per capita CO2 Emission Estimates for Gabon...

172

CO2 Emissions - Grenada  

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Grenada Graphics CO2 Emissions from Grenada Data graphic Data CO2 Emissions from Grenada image Per capita CO2 Emission Estimates for Grenada...

173

CO2 Emissions - Kiribati  

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Oceania Kiribati Graphics CO2 Emissions from Kiribati Data graphic Data CO2 Emissions from Kiribati image Per capita CO2 Emission Estimates for Kiribati...

174

CO2 Emissions - Israel  

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Israel Graphics CO2 Emissions from Israel Data graphic Data CO2 Emissions from Israel image Per capita CO2 Emission Estimates for Israel...

175

CO2 Emissions - Phillippines  

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176

CO2 Emissions - Niger  

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Africa Niger Graphics CO2 Emissions from Niger Data graphic Data CO2 Emissions from Niger image Per capita CO2 Emission Estimates for Niger...

177

CO2 Emissions - Mauritius  

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Africa Mauritius Graphics CO2 Emissions from Mauritius Data graphic Data CO2 Emissions from Mauritius image Per capita CO2 Emission Estimates for Mauritius...

178

CO2 Emissions - Malaysia  

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Malaysia CO2 Emissions from Malaysia Data graphic Data CO2 Emissions from Malaysia image Per capita CO2 Emission Estimates for Malaysia...

179

CO2 Emissions - Reunion  

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Reunion Graphics CO2 Emissions from Reunion Data graphic Data CO2 Emissions from Reunion image Per capita CO2 Emission Estimates for Reunion...

180

CO2 Emissions - Guatemala  

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181

CO2 Emissions - Iceland  

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182

CO2 Emissions - Mongolia  

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Asia Mongolia CO2 Emissions from Mongolia Data graphic Data CO2 Emissions from Mongolia image Per capita CO2 Emission Estimates for Mongolia...

183

CO2 Emissions - Romania  

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184

CO2 Emissions - Panama  

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185

CO2 Emissions - Madagascar  

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186

CO2 Emissions - Netherlands  

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Netherlands CO2 Emissions from Netherlands Data graphic Data CO2 Emissions from Netherlands image Per capita CO2 Emission Estimates for Netherlands...

187

CO2 Emissions - Greenland  

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188

CO2 Emissions - Norway  

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Norway CO2 Emissions from Norway Data graphic Data CO2 Emissions from Norway image Per capita CO2 Emission Estimates for Norway...

189

CO2 Emissions - Guyana  

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190

CO2 Emissions - Mauritania  

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Africa Mauritania Graphics CO2 Emissions from Mauritania Data graphic Data CO2 Emissions from Mauritania image Per capita CO2 Emission Estimates for Mauritania...

191

CO2 Emissions - Lithuania  

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192

CO2 Emissions - Kenya  

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Africa Kenya Graphics CO2 Emissions from Kenya Data graphic Data CO2 Emissions from Kenya image Per capita CO2 Emission Estimates for Kenya...

193

CO2 Emissions - Latvia  

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Centrally Planned Europe Latvia CO2 Emissions from Latvia Data graphic Data CO2 Emissions from Latvia image Per capita CO2 Emission Estimates for Latvia...

194

CO2 Emissions - Georgia  

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Centrally Planned Europe Georgia CO2 Emissions from Georgia Data graphic Data CO2 Emissions from Georgia image Per capita CO2 Emission Estimates for Georgia...

195

CO2 Emissions - Gambia  

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196

CO2 Emissions - Montenegro  

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Centrally Planned Europe Montenegro CO2 Emissions from Montenegro Data graphic Data CO2 Emissions from Montenegro image Per capita CO2 Emission Estimates for Montenegro...

197

CO2 Emissions - Oman  

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Middle East Oman Graphics CO2 Emissions from Oman Data graphic Data CO2 Emissions from Oman image Per capita CO2 Emission Estimates for Oman...

198

CO2 Emissions - Kuwait  

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Middle East Kuwait Graphics CO2 Emissions from Kuwait Data graphic Data CO2 Emissions from Kuwait image Per capita CO2 Emission Estimates for Kuwait...

199

CO2 Emissions - Lebanon  

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Middle East Lebanon Graphics CO2 Emissions from Lebanon Data graphic Data CO2 Emissions from Lebanon image Per capita CO2 Emission Estimates for Lebanon...

200

CO2 Emissions - Nigeria  

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Africa Nigeria Graphics CO2 Emissions from Nigeria Data graphic Data CO2 Emissions from Nigeria image Per capita CO2 Emission Estimates for Nigeria...

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201

CO2 Emissions - Maldives  

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Far East Maldives CO2 Emissions from Maldives Data graphic Data CO2 Emissions from Maldives image Per capita CO2 Emission Estimates for Maldives...

202

CO2 Emissions - Morocco  

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Morocco Graphics CO2 Emissions from Morocco Data graphic Data CO2 Emissions from Morocco image Per capita CO2 Emission Estimates for Morocco...

203

CO2 Emissions - Pakistan  

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Far East Pakistan CO2 Emissions from Pakistan Data graphic Data CO2 Emissions from Pakistan image Per capita CO2 Emission Estimates for Pakistan...

204

CO2 Emissions - Palau  

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Oceania Palau CO2 Emissions from Palau Data graphic Data CO2 Emissions from Palau image Per capita CO2 Emission Estimates for Palau...

205

CO2 Emissions - Qatar  

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Middle East Qatar Graphics CO2 Emissions from Qatar Data graphic Data CO2 Emissions from Qatar image Per capita CO2 Emission Estimates for Qatar...

206

CO2 Emissions - Guam  

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

Oceania Guam Graphics CO2 Emissions from Guam Data graphic Data CO2 Emissions from Guam image Per capita CO2 Emission Estimates for Guam...

207

CO2 Emissions - Rwanda  

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

Africa Rwanda Graphics CO2 Emissions from Rwanda Data graphic Data CO2 Emissions from Rwanda image Per capita CO2 Emission Estimates for Rwanda...

208

CO2 Emissions - Guinea  

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Africa Guinea Graphics CO2 Emissions from Guinea Data graphic Data CO2 Emissions from Guinea image Per capita CO2 Emission Estimates for Guinea...

209

CO2 Emissions - Luxembourg  

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Western Europe Luxembourg CO2 Emissions from Luxembourg Data graphic Data CO2 Emissions from Luxembourg image Per capita CO2 Emission Estimates for Luxembourg...

210

CO2 Emissions - Liberia  

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

Africa Liberia Graphics CO2 Emissions from Liberia Data graphic Data CO2 Emissions from Liberia image Per capita CO2 Emission Estimates for Liberia...

211

CO2 Emissions - Haiti  

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Haiti Graphics CO2 Emissions from Haiti Data graphic Data CO2 Emissions from Haiti image Per capita CO2 Emission Estimates for Haiti...

212

CO2 Emissions - Iraq  

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Iraq Graphics CO2 Emissions from Iraq Data graphic Data CO2 Emissions from Iraq image Per capita CO2 Emission Estimates for Iraq...

213

CO2 Emissions - Hungary  

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Centrally Planned Europe Hungary CO2 Emissions from Hungary Data graphic Data CO2 Emissions from Hungary image Per capita CO2 Emission Estimates for Hungary...

214

CO2 Emissions - Nepal  

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Far East Nepal CO2 Emissions from Nepal Data graphic Data CO2 Emissions from Nepal image Per capita CO2 Emission Estimates for Nepal...

215

CO2 Emissions - Nauru  

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

Nauru Graphics CO2 Emissions from Nauru Data graphic Data CO2 Emissions from Nauru image Per capita CO2 Emission Estimates for Nauru...

216

CO2 Emissions - Myanmar  

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Myanmar CO2 Emissions from Myanmar Data graphic Data CO2 Emissions from Myanmar image Per capita CO2 Emission Estimates for Myanmar...

217

Glossary Term - Neutron Emission  

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

Neutron Previous Term (Neutron) Glossary Main Index Next Term (Niobe) Niobe Neutron Emission After neutron emission, an atom contains one less neutron. Neutron emission is one...

218

Glossary Term - Proton Emission  

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

Proton Previous Term (Proton) Glossary Main Index Next Term (Quark) Quark Proton Emission After proton emission, an atom contains one less proton. Proton emission is one process...

219

CO2 Emissions - Jordan  

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Middle East Jordan Graphics CO2 Emissions from Jordan Data graphic Data CO2 Emissions from Jordan image Per capita CO2 Emission Estimates for Jordan...

220

CO2 Emissions - Greece  

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Western Europe Greece CO2 Emissions from Greece Data graphic Data CO2 Emissions from Greece image Per capita CO2 Emission Estimates for Greece...

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

Episodic Dust Events of Utah’s Wasatch Front and Adjoining Region  

Science Conference Proceedings (OSTI)

Episodic dust events cause hazardous air quality along Utah’s Wasatch Front and dust loading of the snowpack in the adjacent Wasatch Mountains. This paper presents a climatology of episodic dust events of the Wasatch Front and adjoining region ...

W. James Steenburgh; Jeffrey D. Massey; Thomas H. Painter

2012-09-01T23:59:59.000Z

222

CO2 Emissions - Namibia  

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

Fossil Fuel CO2 Emissions Regional Africa Namibia CO2 Emissions from Namibia Data graphic Data CO2 Emissions from Namibia image Per capita CO2 Emission Estimates for...

223

Evolution of Dust Extinction and Supernova Cosmology  

E-Print Network (OSTI)

We have made a quantitative calculation for the systematic evolution of average extinction by interstellar dust in host galaxies of high-redshift Type Ia supernovae, by using a realistic model of photometric and chemical evolution of galaxies and supernova rate histories in various galaxy types. We find that average B band extinction at z \\sim 0.5 is typically 0.1-0.2 mag larger than present, under a natural assumption that dust optical depth is proportional to gas column density and gas metallicity. This systematic evolution causes average reddening with E(B-V) \\sim 0.025-0.05 mag with the standard extinction curve, and this is comparable with the observational uncertainty of the reddening of high-redshift supernovae. Therefore, our result does not contradict the observations showing no significant reddening in high-z supernovae. However, the difference in apparent magnitude between an open universe and a \\Lambda-dominated flat universe is only \\sim 0.2 mag at z \\sim 0.5, and hence this systematic evolution of extinction should be taken into account in a reliable measurement of cosmological parameters. Considering this uncertainty, we show that it is difficult to discriminate between an open and \\Lambda-dominated flat cosmologies from the current data.

Tomonori Totani; Chiaki Kobayashi

1999-10-04T23:59:59.000Z

224

DUST-DRIVEN WIND FROM DISK GALAXIES  

SciTech Connect

We study gaseous outflows from disk galaxies driven by radiation pressure on dust grains. We include the effect of bulge and dark matter halo and show that the existence of such an outflow implies a maximum value of disk mass-to-light ratio. We show that the terminal wind speed is proportional to the disk rotation speed in the limit of a cold gaseous outflow, and that in general there is a contribution from the gas sound speed. Using the mean opacity of dust grains and the evolution of the luminosity of a simple stellar population, we then show that the ratio of the wind terminal speed (v{sub {infinity}}) to the galaxy rotation speed (v{sub c}) ranges between 2 and 3 for a period of {approx}10 Myr after a burst of star formation, after which it rapidly decays. This result is independent of any free parameter and depends only on the luminosity of the stellar population and the relation between disk and dark matter halo parameters. We briefly discuss the possible implications of our results.

Sharma, Mahavir; Nath, Biman B. [Raman Research Institute, Sadashiva Nagar, Bangalore 560080 (India); Shchekinov, Yuri, E-mail: mahavir@rri.res.in, E-mail: biman@rri.res.in, E-mail: yus@sfedu.ru [Department of Physics, Southern Federal University, Rostov on Don 344090 (Russian Federation)

2011-08-01T23:59:59.000Z

225

Two-Component Dust in Spherically Symmetric Motion  

E-Print Network (OSTI)

Two components of spherically symmetric, inhomogeneous dust penetrating each other are introduced as a generalization of the well-known Tolman-Bondi dust solution. The field equations of this model are formulated and general properties are discussed. inhomogeneous Special solutions with additional symmetries - an extra Killing- or homothetic vector - and their matching to the corresponding Tolman-Bondi solution are investigated.

Haager, G

1997-01-01T23:59:59.000Z

226

Two-Component Dust in Spherically Symmetric Motion  

E-Print Network (OSTI)

Two components of spherically symmetric, inhomogeneous dust penetrating each other are introduced as a generalization of the well-known Tolman-Bondi dust solution. The field equations of this model are formulated and general properties are discussed. inhomogeneous Special solutions with additional symmetries - an extra Killing- or homothetic vector - and their matching to the corresponding Tolman-Bondi solution are investigated.

Gernot Haager

1997-05-02T23:59:59.000Z

227

Dust en-route to Jupiter and the Galilean satellites  

E-Print Network (OSTI)

Spacecraft investigations during the last ten years have vastly improved our knowledge about dust in the Jovian system. All Galilean satellites, and probably all smaller satellites as well, are sources of dust in the Jovian system. In-situ measurements with the dust detectors on board the Ulysses and Galileo spacecraft have for the first time demonstrated the electromagnetic interaction of charged dust grains with the interplanetary magnetic field and with a planetary magnetosphere. Jupiter's magnetosphere acts as a giant mass-velocity spectrometer for charged 10-nanometer dust grains. These dust grains are released from Jupiter's moon Io with typical rate of 1 kg s^1. The dust streams probe the plasma conditions in the Io plasma torus and can be used as a potential monitor of Io's volcanic plume activity. The other Galilean satellites are surrounded by tenuous impact-generated clouds of mostly sub-micrometer ejecta grains. Galileo measurements have demonstrated that impact-ejecta derived from hypervelocity impacts onto satellites are the major -- if not the only -- constituent of dusty planetary rings. We review the in-situ dust measurements at Jupiter and give an update of most recent results.

Harald Krueger; Eberhard Gruen

2002-05-28T23:59:59.000Z

228

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

Moore, Keith

229

INTERSTELLAR DUST MODULE FOR THE ESA METEOROID MODEL  

E-Print Network (OSTI)

The ESA meteoroid model predicts impacts of meteoroids in the mass range between 10 ?18 to 10 0 g on spacecraft surfaces. It covers heliocentric distances from 0.3 to 20 AU. Measurements of the dust detector on board the highly successful joint ESA/NASA mission Ulysses have shown, that the flux of meteoroids with masses between 10 ?15 and 10 ?12 g is, at least in the outer Solar System, dominated by interstellar dust grains that traverse the Solar System as it travels through the local interstellar cloud. We present a simple semi-analytic interstellar dust model that can easily be included in the ESA meteoroid model, together with a more precise determination of the flux direction of the interstellar dust stream. The model is based on the assumption that interstellar dust dynamics have two effects: solar gravitation and radiation pressure determines the spatial distribution, and Lorentz-interaction of the charged particles creates a temporal variation. 1.

R. Jehn; N. Altobelli; V. Dikarev; E. Grün

2001-01-01T23:59:59.000Z

230

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

SciTech Connect

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

231

THE ORIGIN OF DUST IN THE EARLY UNIVERSE: PROBING THE STAR FORMATION HISTORY OF GALAXIES BY THEIR DUST CONTENT  

SciTech Connect

Two distinct scenarios for the origin of the {approx}4 x 10{sup 8} M{sub sun} of dust observed in the high-redshift (z = 6.4) quasar J1148+5251 have been proposed. The first assumes that this galaxy is much younger than the age of the universe at that epoch so that only supernovae (SNe) could have produced this dust. The second scenario assumes a significantly older galactic age, so that the dust could have formed in lower-mass asymptotic giant branch (AGB) stars. Presenting new integral solutions for the chemical evolution of metals and dust in galaxies, we offer a critical evaluation of these two scenarios and observational consequences that can discriminate between the two. We show that AGB stars can produce the inferred mass of dust in this object, however, the final mass of surviving dust depends on the galaxy's star formation history (SFH). In general, SNe cannot produce the observed amount of dust unless the average SN event creates over {approx}2 M{sub sun} of dust in its ejecta. However, special SFHs can be constructed in which SNe can produce the inferred dust mass with a reasonable average dust yield of {approx}0.15 M{sub sun}. The two scenarios propose different origins for the galaxy's spectral energy distribution, different star formation efficiencies and stellar masses, and consequently different comoving number densities of J1148+5251-type hyperluminous infrared (IR) objects. The detection of diagnostic mid-IR fine structure lines and more complete surveys determining the comoving number density of these objects can discriminate between the two scenarios.

Dwek, Eli [Observational Cosmology Lab, Code 665, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Cherchneff, Isabelle, E-mail: eli.dwek@nasa.gov, E-mail: isabelle.cherchneff@unibas.ch [Department Physik, Universitaet Basel, CH-4056 Basel (Switzerland)

2011-02-01T23:59:59.000Z

232

Radionuclide Air Emissions Report for the Hanford Site Calendar year 1998  

SciTech Connect

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

233

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 t...

Lobo, F S N

2004-01-01T23:59:59.000Z

234

A new method to generate dust with astrophysical properties  

SciTech Connect

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

235

Quantification of Black Carbon and Other Pollutant Emissions from a  

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

Quantification of Black Carbon and Other Pollutant Emissions from a Quantification of Black Carbon and Other Pollutant Emissions from a Traditional and an Improved Cookstove Title Quantification of Black Carbon and Other Pollutant Emissions from a Traditional and an Improved Cookstove Publication Type Report LBNL Report Number LBNL-6062E Year of Publication 2010 Authors Kirchstetter, Thomas W., Chelsea Preble, Odelle L. Hadley, and Ashok J. Gadgil Keywords aethalometer, Berkeley Darfur Stove, black carbon, carbon monoxide, climate change, DustTrak, global warming, improved cookstoves, indoor air quality, LBNL Stove Testing Facility, particulate matter, photoacoustic absorption spectrometer, pollutant emission factor, three-stone fire Abstract Traditional methods of cooking in developing regions of the world emit pollutants that

236

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

237

Modeling water emission from low-mass protostellar envelopes  

E-Print Network (OSTI)

Within low-mass star formation, water vapor plays a key role in the chemistry and energy balance of the circumstellar material. The Herschel Space Observatory will open up the possibility to observe water lines originating from a wide range of excitation energies.Our aim is to simulate the emission of rotational water lines from envelopes characteristic of embedded low-mass protostars. A large number of parameters that influence the water line emission are explored: luminosity, density,density slope and water abundances.Both dust and water emission are modelled using full radiative transfer in spherical symmetry. The temperature profile is calculated for a given density profile. The H2O level populations and emission profiles are in turn computed with a non-LTE line code. The results are analyzed to determine the diagnostic value of different lines, and are compared with existing observations. Lines can be categorized in: (i) optically thick lines, including ground-state lines, mostly sensitive to the cold outer part; (ii) highly excited (E_u>200-250 K) optically thin lines sensitive to the abundance in the hot inner part; and (iii) lines which vary from optically thick to thin depending on the abundances. Dust influences the emission of water significantly by becoming optically thick at the higher frequencies, and by pumping optically thin lines. A good physical model of a source, including a correct treatment of dust, is a prerequisite to infer the water abundance structure and possible jumps at the evaporation temperature from observations. The inner warm (T>100 K) envelope can be probed byhighly-excited lines, while a combination of excited and spectrally resolved ground state lines probes the outer envelope. Observations of H218O lines, although weak, provide even stronger constraints on abundances.

T. A. van Kempen; S. D. Doty; E. F. van Dishoeck; M. R. Hogerheijde; J. K. Joergensen

2008-05-06T23:59:59.000Z

238

EIA - Greenhouse Gas Emissions - Nitrous Oxide Emissions  

Gasoline and Diesel Fuel Update (EIA)

4. Nitrous Oxide Emissions 4. Nitrous Oxide Emissions 4.1 Total emissions U.S. nitrous oxide emissions in 2009 were 4 MMTCO2e (1.7 percent) below their 2008 total (Table 22). Sources of U.S. nitrous oxide emissions include agriculture, energy use, industrial processes, and waste management (Figure 22). The largest source is agriculture (73 percent), and the majority of agricultural emissions result from nitrogen fertilization of agricultural soils (87 percent of the agriculture total) and management of animal waste (13 percent). U.S. nitrous oxide emissions rose from 1990 to 1994, fell from 1994 to 2002, and returned to an upward trajectory from 2003 to 2007, largely as a result of increased use of synthetic fertilizers. Fertilizers are the primary contributor of emissions from nitrogen fertilization of soils, which grew by more than 30 percent from

239

Thermal Impact of Saharan Dust over Land. Part I: Simnulation  

Science Conference Proceedings (OSTI)

Simulations are carded out to verify a mesoscale model in order to perform sensitivity tests of satellite response to atmospheric dust content. The model chosen is the mesoscale model of Colorado State University with a modified radiation ...

Guy Cautenet; Michel Legrand; Sylvie Cautenet; Bernard Bonnel; Gérard Brogniez

1992-02-01T23:59:59.000Z

240

A Case Study of Mobilization and Transport of Saharan Dust  

Science Conference Proceedings (OSTI)

Numerical models of the atmosphere and aerosols are used to investigate mobilization and transport of Saharan dust over West Africa and the tropical Atlantic Ocean for 23–28 August 1974. We have found that mobilization during this period was ...

Douglas L. Westphal; Owen B. Toon; Toby N. Carlson

1988-08-01T23:59:59.000Z

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.


241

Aerobiology and the global transport of desert dust  

E-Print Network (OSTI)

misconception that all microorganisms in dust clouds are killed by solar UV-radiation, lack of nutrients and desiccation during their multi-day journey. In fact, some genera of bacteria (e.g. Bacillus) and most fungi

Ahmad, Sajjad

242

Metal Dusting [Corrosion and Mechanics of Materials] - Nuclear...  

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

Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Corrosion and Mechanics of Materials Metal Dusting Bookmark and Share R&D 100 AWARD The "Materials resistant...

243

Saharan Dust Aerosol Radiative Forcing Measured from Space  

Science Conference Proceedings (OSTI)

This study uses data collected from the Clouds and the Earth's Radiant Energy System (CERES) and the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments to determine Saharan dust broadband shortwave aerosol radiative forcing over ...

F. Li; A. M. Vogelmann; V. Ramanathan

2004-07-01T23:59:59.000Z

244

Morphological investigations of fibrogenic action of Estonian oil shale dust  

SciTech Connect

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 shale dust over a long period (more than 20 years) may cause the development of occupational pneumoconiotic changes in oil shale miners. The pneumoconiotic process develops slowly and is characterized by changes typical of the interstitial form of pneumoconiotic fibrosis in the lungs. Emphysematous changes and chronic bronchitis also occur. The average chemical content of oil shale as well as of samples of oil shale dust generated during mining and sorting procedures is given. The results of experiments in white rats are presented; these studies also indicate a mild fibrogenic action of Estonian oil shale dust.

Kung, V.A.

1979-06-01T23:59:59.000Z

245

Dust Accumulation Biases in PIRATA Shortwave Radiation Records  

Science Conference Proceedings (OSTI)

Long-term and direct measurements of surface shortwave radiation (SWR) have been recorded by the Prediction and Research Moored Array in the Tropical Atlantic (PIRATA) since 1997. Previous studies have shown that African dust, transported westward ...

Gregory R. Foltz; Amato T. Evan; H. Paul Freitag; Sonya Brown; Michael J. McPhaden

2013-07-01T23:59:59.000Z

246

Next Century Challenges: Mobile Networking for "Smart Dust"  

E-Print Network (OSTI)

Next Century Challenges: Mobile Networking for "Smart Dust" J. M. Kahn, R. H. Katz (ACM Fellow), K be small enough to remain suspended in air, buoyed by air currents, sensing and communicating for hours

Kahn, Joseph M.

247

Magnetorotational instability in plasmas with mobile dust grains  

SciTech Connect

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

248

An experimental study of deflagration to detonation transition supported by dust layers  

SciTech Connect

The roles which dust layers play in severe dust explosions were investigated in a 70-m-long and 30-cm-diameter horizontal Flame Acceleration Tube (FAT) with one end closed and the other end open to the atmosphere. A variety of dusts such as corn dust, cornstarch, Mira Gel starch, wheat dust, and wood flour were layered on the bottom half of the FAT. Flame and detonation propagation parameters were closely monitored at different locations along the FAT. The study demonstrated that the moisture content of the dust, the exposed area of the dust layers to the convective flow, and the physical characteristics of the dust are the factors that most determine the severity of layered dust explosions, indicating that prelayered dust combustion is dominated by the dust/air mixing process. While the dust explosion rate constant K{sub st} can be used to characterize dust explosibility in predispersed dust in constant volume enclosures, it does not appear to characterize the behavior of layered dust explosions. Qualitative measurements of the variation of dust concentration during a layered dust explosion were obtained. The measurements indicated that the dust concentration at the time of flame arrival is highly nonuniform. The maximum pressure rise (P{sub max} {minus} P{sub 0}) within the FAT during a layered dust explosion was found to vary linearly with the flame velocity V{sub f} when V{sub f} is subsonic. As V{sub f} reaches supersonic values the maximum pressure increase was found to vary with the V{sub f}{sup 2}, the square of the flame velocity. This result was found to be independent of dust type and concentration.

Li, Y.C.; Kauffman, C.W.; Sichel, M. [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Aerospace Engineering] [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Aerospace Engineering

1995-02-01T23:59:59.000Z

249

EIA - Greenhouse Gas Emissions - Methane Emissions  

U.S. Energy Information Administration (EIA)

Residential wood consumption accounted for just over 45 percent of U.S. methane emissions from stationary combustion in 2009.

250

CO2 Emissions - Peru  

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

Central America, South America, and the Caribbean Nations Peru Graphics CO2 Emissions from Peru Data graphic Data CO2 Emissions from Peru image Per capita CO2 Emission Estimates...

251

CO2 Emissions - Bolivia  

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

Central America, South America, and the Caribbean Nations Bolivia Graphics CO2 Emissions from Bolivia Data graphic Data CO2 Emissions from Bolivia image Per capita CO2 Emission...

252

CO2 Emissions - Jamaica  

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

Central America, South America, and the Caribbean Nations Jamaica Graphics CO2 Emissions from Jamaica Data graphic Data CO2 Emissions from Jamaica image Per capita CO2 Emission...

253

SF6 Emission Reduction  

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

SF 6 Emission Reduction Steve Lowder Bonneville Power Administration 2010.09 slide 1 Emission Reduction Emission Reduction is the reason for why we do all of this - because:...

254

Photochemical Oxidant Processes in the Presence of Dust: An Evaluation of the Impact of Dust on Particulate Nitrate and Ozone Formation  

Science Conference Proceedings (OSTI)

The influence of dust on the tropospheric photochemical oxidant cycle is studied through the use of a detailed coupled aerosol and gas-phase chemistry model. Dust is a significant component of the troposphere throughout Asia and provides a ...

Yang Zhang; Young Sunwoo; Veerabhadra Kotamarthi; Gregory R. Carmichael

1994-07-01T23:59:59.000Z

255

Dust explosion hazards due to blasting of oil shale  

SciTech Connect

The conditions favoring secondary explosions of dust or gas accompanying the blasting of oil shale are the subject of continuing investigation by the Bureau of Mines. In the present study, oil shale dust was dispersed in a gallery and ignited by various blasting agents blown out of a cannon according to a standard testing procedure. Parallel tests were conducted in the Bureau's Experimental Mine to test propagation as well as ignition of oil shale dust. In both gallery and mine, the minimum explosion limits were determined as a function of dust loading, weight and type of blasting agent, and amount of added methane. The results of these experiments are compared with previous measurements using methane-air explosions as an initiation source. In view of recent mine dust sampling data, the main explosion hazard in nongassy oil shale mines is likely to be limited to the region of the face. But in gassy mines, dust-gas explosions could be expected to propagate considerable distances.

Richmond, J.K.; Beitel, F.P.

1984-04-01T23:59:59.000Z

256

Development of materials resistant to metal dusting degradation.  

Science Conference Proceedings (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

257

Secular Instability and Planetesimal Formation in the Dust Layer  

E-Print Network (OSTI)

Late in the gaseous phase of a protostellar disk, centimeter-sized bodies probably settle into a thin ``dust layer'' at the midplane. A velocity difference between the dust layer and the gas gives rise to turbulence, which prevents further settling and direct gravitational instability of the layer. The associated drag on the surface of the layer causes orbital decay in a few thousand years---as opposed to a few hundred years for an isolated meter-sized body. Within this widely-accepted theoretical framework, we show that the turbulent drag causes radial instabilities even if the selfgravity of the layer is negligible. We formulate axisymmetric, height-integrated dynamical equations for the layer that incorporate turbulent diffusion of mass and momentum in radius and height, vertical settling, selfgravity, and resistance to compression due to gas entrained within the dust layer. In steady-state, the equations describe the inward radial drift of a uniform dust layer. In perturbation, overdense rings form on an orbital timescale with widths comparable to the dust-layer thickness. Selfgravity is almost irrelevant to the linear growth rate but will eventually fragment and collapse the rings into planetesimals larger than a kilometer. We estimate that the drag instability is most efficient at 1 AU when most of the ``dust'' mass lies in the size range 0.1-10 meters.

J. Goodman; B. Pindor

1999-12-28T23:59:59.000Z

258

Bipolar charging of dust particles under ultraviolet radiation  

SciTech Connect

The photoemission charging of dust particles under ultraviolet radiation from a xenon lamp has been investigated. The velocities of yttrium dust particles with a work function of 3.3 eV and their charges have been determined experimentally; the latter are about 400-500 and about 100 elementary charges per micron of radius for the positively and negatively charged fractions, respectively. The dust particle charging and the dust cloud evolution in a photoemission cell after exposure to an ultraviolet radiation source under the applied voltage have been simulated numerically. The photoemission charging of dust particles has been calculated on the basis of nonlocal and local charging models. Only unipolar particle charging is shown to take place in a system of polydisperse dust particles with the same photoemission efficiency. It has been established that bipolar charging is possible in the case of monodisperse particles with different quantum efficiencies. Polydispersity in this case facilitates the appearance of oppositely charged particles in a photoemission plasma.

Filippov, A. V., E-mail: fav@triniti.ru; Babichev, V. N. [Troitsk Institute for Innovation and Fusion Research, State Research Center of the Russian Federation (Russian Federation); Fortov, V. E.; Gavrikov, A. V. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation); Pal', A. F. [Troitsk Institute for Innovation and Fusion Research, State Research Center of the Russian Federation (Russian Federation); Petrov, O. F. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation); Starostin, A. N.; Sarkarov, N. E. [Troitsk Institute for Innovation and Fusion Research, State Research Center of the Russian Federation (Russian Federation)

2011-05-15T23:59:59.000Z

259

HTGR Dust Safety Issues and Needs for Research and Development  

Science Conference Proceedings (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

260

CO2 Emissions - Montserrat  

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

Central America, South America, and the Caribbean Nations Montserrat Graphics CO2 Emissions from Montserrat Data graphic Data CO2 Emissions from Montserrat image Per capita CO2...

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

CO2 Emissions - Martinique  

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

Central America, South America, and the Caribbean Nations Martinique Graphics CO2 Emissions from Martinique Data graphic Data CO2 Emissions from Martinique image Per capita CO2...

262

CO2 Emissions - Honduras  

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

Central America, South America, and the Caribbean Nations Honduras Graphics CO2 Emissions from Honduras Data graphic Data CO2 Emissions from Honduras image Per capita CO2...

263

CO2 Emissions - Nicaragua  

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

Central America, South America, and the Caribbean Nations Nicaragua Graphics CO2 Emissions from Nicaragua Data graphic Data CO2 Emissions from Nicaragua image Per capita CO2...

264

Trends Online Methane Emissions  

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

Emissions Introduction Annual Estimates of Global Anthropogenic Methane Emissions: 1860-1994 - D.I. Stern and R.K. Kaufmann Contents-Trends | CDIAC Home 102001...

265

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

266

EIA - Greenhouse Gas Emissions - Carbon Dioxide Emissions  

Gasoline and Diesel Fuel Update (EIA)

2. Carbon Dioxide Emissions 2. Carbon Dioxide Emissions 2.1. Total carbon dioxide emissions Annual U.S. carbon dioxide emissions fell by 419 million metric tons in 2009 (7.1 percent), to 5,447 million metric tons (Figure 9 and Table 6). The annual decrease-the largest over the 19-year period beginning with the 1990 baseline-puts 2009 emissions 608 million metric tons below the 2005 level, which is the Obama Administration's benchmark year for its goal of reducing U.S. emissions by 17 percent by 2020. The key factors contributing to the decrease in carbon dioxide emissions in 2009 included an economy in recession with a decrease in gross domestic product of 2.6 percent, a decrease in the energy intensity of the economy of 2.2 percent, and a decrease in the carbon intensity of energy supply of

267

Catalysts for Lean Engine Emission Control - Emissions & Emission...  

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

controlling NOx emissions from lean engines is challenging. Traditionally, for the stoichiometric gasoline engine vehicles that dominate the U.S. passenger car market, a three-way...

268

AMI OBSERVATIONS OF THE ANOMALOUS MICROWAVE EMISSION IN THE PERSEUS MOLECULAR CLOUD  

SciTech Connect

We present observations of the known anomalous microwave emission region, G159.6-18.5, in the Perseus molecular cloud at 16 GHz performed with the Arcminute Microkelvin Imager Small Array. These are the highest angular resolution observations of G159.6-18.5 at microwave wavelengths. By combining these microwave data with infrared observations between 5.8 and 160 {mu}m from the Spitzer Space Telescope, we investigate the existence of a microwave-infrared correlation on angular scales of {approx}2'. We find that the overall correlation appears to increase toward shorter infrared wavelengths, which is consistent with the microwave emission being produced by electric dipole radiation from small, spinning dust grains. We also find that the microwave-infrared correlation peaks at 24 {mu}m (6.7{sigma}), suggesting that the microwave emission is originating from a population of stochastically heated small interstellar dust grains rather than polycyclic aromatic hydrocarbons.

Tibbs, C. T. [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); Scaife, A. M. M. [School of Physics and Astronomy, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Dickinson, C.; Davies, R. D.; Davis, R. J.; Watson, R. A. [Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL (United Kingdom); Paladini, R. [NASA Herschel Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); Grainge, K. J. B., E-mail: ctibbs@ipac.caltech.edu [Astrophysics Group, Cavendish Laboratory, J J Thomson Avenue, Cambridge CB3 0HE (United Kingdom)

2013-05-10T23:59:59.000Z

269

Development of materials resistant to metal dusting degradation.  

DOE Green Energy (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

270

EIA - Greenhouse Gas Emissions - Methane Emissions  

Gasoline and Diesel Fuel Update (EIA)

oil production dropping by 28 percent from 1990 to 2009, methane emissions from petroleum exploration and production have declined by the same percentage. Residential wood...

271

EIA - Greenhouse Gas Emissions - Carbon Dioxide Emissions  

U.S. Energy Information Administration (EIA)

Nonfuel uses of fossil fuels (for purposes other than their energy value) create carbon dioxide emissions and also sequester carbon in nonfuel products, ...

272

Modeling the Dust Spectral Energy Distributions of Dwarf Galaxies  

E-Print Network (OSTI)

Recent efforts on the modeling of the infrared spectral energy distributions (SEDs) of dwarf galaxies are summarised here. The characterisation of the dust properties in these low metallicity environments is just unfolding, as a result of recently available mid-infrared to millimetre observations. From the limited cases we know to date, it appears that the hard radiation fields that are present in these star-bursting dwarf galaxies, as well as the rampent energetics of supernovae shocks and winds have modified the dust properties, in comparison with those in the Galaxy, or other gas and dust rich galaxies. The sophistication of the SED models is limited by the availability of detailed data in the mid infrared and particularly in the submillimetre to millimetre regime, which will open up in the near future with space-based missions, such as Herschel.

Suzanne C. Madden

2005-01-31T23:59:59.000Z

273

Lithium Wall Conditioning And Surface Dust Detection On NSTX  

Science Conference Proceedings (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

274

Dust Tracking Using Composite Visible/IR Images: A Case Study  

Science Conference Proceedings (OSTI)

Visible and infrared (IR) images from the National Oceanic and Atmospheric Administration's (NOAA's) Advanced Very High Resolution Radiometer are composited to improve the depiction of airborne dust over coastlines. On IR images, wind-raised dust ...

Thomas F. Lee

1989-06-01T23:59:59.000Z

275

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

276

Multidecadal Covariability of North Atlantic Sea Surface Temperature, African Dust, Sahel Rainfall, and Atlantic Hurricanes  

Science Conference Proceedings (OSTI)

Most studies of African dust and North Atlantic climate have been limited to the short time period since the satellite era (1980 onward), precluding the examination of their relationship on longer time scales. Here a new dust dataset with the ...

Chunzai Wang; Shenfu Dong; Amato T. Evan; Gregory R. Foltz; Sang-Ki Lee

2012-08-01T23:59:59.000Z

277

Radiative Effects of Airborne Dust on Regional Energy Budgets at the Top of the Atmosphere  

Science Conference Proceedings (OSTI)

The effects of dust on the radiative energy budget at the top of the atmosphere were investigated using model calculations and measurements from the Earth Radiation Budget Experiment (ERBE). Estimates of the dust optical depth were made from ...

Steven A. Ackerman; Hyosang Chung

1992-02-01T23:59:59.000Z

278

EMISSION AND TRANSMISSION NOISE PROPAGATION IN POSITRON EMISSION COMPUTED TOMOGRAPHY  

E-Print Network (OSTI)

26-29, 1979 EMISSION AND TRANSMISSION NOISE PROPAGATION INLBL-9783 EMISSION AND TRANSMISSION NOISE PROPAGATION INl·. LBL-9783 EMISSION AND TRANSMISSION NOISE PROPAGATION IN

Gullberg, G.T.

2010-01-01T23:59:59.000Z

279

Beyond Tailpipe Emissions  

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

Beyond Tailpipe Emissions Beyond Tailpipe Emissions Greenhouse Gas Emissions for Electric and Plug-In Hybrid Electric Vehicles Driving your vehicle can yield both greenhouse gas (GHG) emissions from your vehicle's tailpipe and GHG emissions related to the production of the fuel used to power your vehicle. For example, activities associated with fuel production such as feedstock extraction, feedstock transport to a processing plant, and conversion of feedstock to motor fuel, as well as distribution of the motor fuel, can all produce GHG emissions. The Fuel Economy and Environment Label provides a Greenhouse Gas Rating, from 1 (worst) to 10 (best), based on the vehicle's tailpipe carbon dioxide emissions only, and this rating does not reflect any GHG emissions associated with fuel production.

280

Excess Emissions (New Mexico)  

Energy.gov (U.S. Department of Energy (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...

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

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

Science Conference Proceedings (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

282

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

Science Conference Proceedings (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

283

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

284

The Diurnal and Seasonal Cycles of Wind-Borne Dust over Africa North of the Equator  

Science Conference Proceedings (OSTI)

This article presents a study of the diurnal and seasonal cycles of dust over North Africa, using surface visibility as an indicator of dust. The diurnal cycle shows a reduction of visibility during the daytime hours in the areas where dust is ...

G. N’Tchayi Mbourou; J. J. Bertrand; S. E. Nicholson

1997-07-01T23:59:59.000Z

285

COAMPS Real-Time Dust Storm Forecasting during Operation Iraqi Freedom  

Science Conference Proceedings (OSTI)

Dust storms are a significant weather phenomenon in the Iraq region in winter and spring. Real-time dust forecasting using the U.S. Navy’s Coupled Ocean–Atmospheric Mesoscale Prediction System (COAMPS) with an in-line dust aerosol model was ...

Ming Liu; Douglas L. Westphal; Annette L. Walker; Teddy R. Holt; Kim A. Richardson; Steven D. Miller

2007-02-01T23:59:59.000Z

286

Kinetic theory of magnetized dusty plasmas with dust particles charged by collisional processes and by photoionization  

SciTech Connect

In this work, we detail the derivation of a plasma kinetic theory leading to the components of the dielectric tensor for a magnetized dusty plasma with variable charge on the dust particles, considering that the dust component of the plasma contains spherical dust particles with different sizes, which are charged both by inelastic collisions of electrons and ions and by photoionization.

Galvao, R. A.; Ziebell, L. F. [Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Caixa Postal 15051, CEP 91501-970, Porto Alegre, RS (Brazil)

2012-09-15T23:59:59.000Z

287

CO2 Emissions - Guinea Bissau  

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

Guinea Bissau Graphics CO2 Emissions from Guinea Bissau Data graphic Data CO2 Emissions from Guinea Bissau image Per capita CO2 Emission Estimates for Guinea Bissau...

288

CO2 Emissions - Peninsular Malaysia  

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

Fossil-Fuel CO2 Emissions Regional Far East Peninsular Malaysia CO2 Emissions from Peninsular Malaysia Data graphic Data CO2 Emissions from Peninsular Malaysia image Per...

289

CO2 Emissions - New Caledonia  

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

New Caledonia Graphics CO2 Emissions from New Caledonia Data graphic Data CO2 Emissions from New Caledonia image Per capita CO2 Emission Estimates for New Caledonia...

290

CO2 Emissions - United Korea  

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

Fossil Fuel CO2 Emissions Regional Centrally Planned Asia United Korea CO2 Emissions from United Korea Data graphic Data CO2 Emissions from United Korea...

291

Greenhouse Gas Emissions Inventory  

E-Print Network (OSTI)

are calculated using the eGRID post 2006 emission factor for all subject years (1990-2009); the CA-CP Calculator uses a different (lower) factor (eGRID pre 2006) for years 1990-2006. WUSTL deviated from the CA-CP Calculator on this emission factor because using the pre and post eGRID factors skews GHG emissions

Dobbins, Ian G.

292

Dust and Black Carbon in Seasonal Snow Across Northern China  

Science Conference Proceedings (OSTI)

Snow is the most reflective natural surface on Earth. Its albedo (the fraction of sunlight reflected) can be reduced by small amounts of dark impurities such as dust and black carbon (BC) particles. This effect is significant for climate and the ...

Jianping Huang; Qiang Fu; Wu Zhang; Xin Wang; Rudong Zhang; Hao Ye; Stephen G. Warren

2011-02-01T23:59:59.000Z

293

An observational Study of the “Interstate 5” Dust Storm Case  

Science Conference Proceedings (OSTI)

On 29 November 1991 a series of collisions involving 164 vehicles occurred on Interstate 5 in the San Joaquin Valley in California in a dust storm that reduced the visibility to near zero. The accompanying high surface winds are hypothesized to ...

Patricia M. Pauley; Nancy L. Baker; Edward H. Barker

1996-04-01T23:59:59.000Z

294

Gas-cooling by dust during dynamical fragmentation  

E-Print Network (OSTI)

We suggest that the abrupt switch, from hierarchical clustering on scales larger than 0.04 pc, to binary (and occasionally higher multiple) systems on smaller scales, which Larson has deduced from his analysis of the grouping of pre-Main-Sequence stars in Taurus, arises because pre-protostellar gas becomes thermally coupled to dust at sufficiently high densities. The resulting change from gas-cooling by molecular lines at low densities to gas-cooling by dust at high densities enables the matter to radiate much more efficiently, and hence to undergo dynamical fragmentation. We derive the domain where gas-cooling by dust facilitates dynamical fragmentation. Low-mass (i.e. solar mass) clumps - those supported mainly by thermal pressure - can probably access this domain spontaneously, albeit rather quasistatically, provided they exist in a region where external perturbations are few and far between. More massive clumps probably require an impulsive external perturbation, for instance a supersonic collision with another clump, in order for the gas to reach sufficiently high density to couple thermally to the dust. Impulsive external perturbations should promote fragmentation, by generating highly non-line ar substructures which can then be amplified by gravity during the subsequent collapse.

A. P. Whitworth; H. M. J. Boffin; N. Francis

1998-04-30T23:59:59.000Z

295

SPATIAL VARIATIONS OF DUST ABUNDANCES ACROSS THE LARGE MAGELLANIC CLOUD  

SciTech Connect

Using the data obtained with the Spitzer Space Telescope as part of the Surveying the Agents of a Galaxy's Evolution (SAGE) legacy survey, we have studied the variations of the dust composition and abundance across the Large Magellanic Cloud (LMC). Such variations are expected, as the explosive events which have lead to the formation of the many H I shells observed should have affected the dust properties. Using a model and comparing with a reference spectral energy distribution from our Galaxy, we deduce the relative abundance variations of small dust grains across the LMC. We examined the infrared color ratios as well as the relative abundances of very small grains (VSGs) and polycyclic aromatic hydrocarbons (PAHs) relative to the big grain abundance. Results show that each dust component could have different origins or evolution in the interstellar medium (ISM). The VSG abundance traces the star formation activity and could result from shattering of larger grains, whereas the PAH abundance increases around molecular clouds as well as in the stellar bar, where they could have been injected into the ISM during mass loss from old stars.

Paradis, Deborah; Reach, William T. [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Bernard, Jean-Philippe [Universite de Toulouse, UPS, CESR, 9 av. du Colonel Roche, F-31028 Toulouse cedex 9 (France); Block, Miwa; Engelbracht, Chad W.; Gordon, Karl [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Hora, Joseph L. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., MS-65, Cambridge, MA, 02138-1516 (United States); Indebetouw, Remy [7 National Radio Astronomy Observatory and Department of Astronomy, University of Virginia, P.O. Box 3818, Charlottesville, VA 22903-0818 (United States); Kawamura, Akiko [Nagoya University, Department of Astrophysics, Chikusa-Ku, Nagoya, 464-01 (Japan); Meade, Marilyn [Department of Astronomy, University of Wisconsin, Madison, 475 N. Charter St., Madison, WI 53706 (United States); Meixner, Margaret; Sewilo, Marta [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Vijh, Uma P. [Ritter Astrophysical Research Center, University of Toledo, Toledo, OH 43606 (United States); Volk, Kevin [Gemini Observatory, Northern Operations Center, 670 N. Aohuku Place, Hilo, HI 96720 (United States)

2009-07-15T23:59:59.000Z

296

Dust and the ultraviolet energy distribution of quasars  

E-Print Network (OSTI)

The ultraviolet energy distribution of quasars shows a sharp steepening of the continuum shortward of 1000 A (rest-frame). We describe how we came to consider the possibility that this continuum break might be the result of absorption by carbon crystallite dust grains.

Luc Binette; Christophe Morisset; Sinhue Haro-Corzo

2005-09-24T23:59:59.000Z

297

Simulation of Transport and Removal Processes of the Saharan Dust  

Science Conference Proceedings (OSTI)

A planetary boundary layer (PBL) model has been modified to include a Saharan air layer containing the bulk of Saharan dust. The Saharan air layer is recognized as a deep mixed layer which extends up to 4–6 km during hot summer months and is ...

In-Young Lee

1983-04-01T23:59:59.000Z

298

Stochastic fluctuations of dust particle charge in RF discharges  

Science Conference Proceedings (OSTI)

In addition to RF oscillations, intrinsic stochastic fluctuations due to the discreteness of electrons and ions could be important to the charging of a dust particle in RF discharges. These fluctuations are studied in the present work for three cases [M. Bacharis et al., Plasma Sources Sci. Technol. 19, 025002 (2010)] relevant to RF discharges employing a recently proposed model [B. Shotorban, Phys. Rev. E 83, 066403 (2011)] valid for stochastic charging at nonstationary states. The cases are concerned with a time varying electron number density relevant to sheaths, a time varying electric field relevant to the bulk plasma, and a time-dependent bi-Maxwellian distribution of electrons in a low pressure discharge. Two dust particles with different sizes are individually studied in each case. The radius of one is ten times larger than the radius of the other. In all of the cases, for the larger dust particle, the root-mean-squre of charge stochastic fluctuations is about an order of magnitude smaller than the amplitude of RF charge oscillations, while for the smaller dust particle, they are comparable in magnitude.

Shotorban, B. [Department of Mechanical and Aerospace Engineering, University of Alabama in Huntsville, Huntsville, Alabama 35899 (United States)

2012-05-15T23:59:59.000Z

299

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

300

Doppler Radar Observations of Dust Devils in Texas  

Science Conference Proceedings (OSTI)

Analyses of a dust-devil dataset collected in northwest Texas are presented. The data were collected just above the ground at close range with a mobile, W-band (3-mm wavelength) Doppler radar having an azimuthal (radial) resolution of 3–5 m (30 m)...

Howard B. Bluestein; Christopher C. Weiss; Andrew L. Pazmany

2004-01-01T23:59:59.000Z

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

STAR FORMATION AND DISTRIBUTIONS OF GAS AND DUST IN THE CIRCINUS CLOUD  

Science Conference Proceedings (OSTI)

We present results of a study on the Circinus cloud based on {sup 13}CO (J = 1 - 0) data as well as visual to near-infrared (JHK{sub S}) extinction maps, to investigate the distributions of gas and dust around the cloud. The global {sup 13}CO distribution of the Circinus cloud is revealed for the first time, and the total molecular mass of the cloud is estimated to be 2.5 x 10{sup 4} M{sub sun} for the assumed distance 700 pc. Two massive clumps in the cloud, called Circinus-W and Circinus-E, have a mass of {approx}5 x 10{sup 3} M{sub sun}. These clumps are associated with a number of young stellar objects (YSOs) searched for in the literature, indicating that they are the most active star-forming sites in Circinus. All of the extinction maps show good agreement with the {sup 13}CO distribution. We derived the average N({sup 13}CO)/A{sub V} ratio in the Circinus cloud to be 1.25 x 10{sup 15} cm{sup -2} mag{sup -1} by comparing the extinction maps with the {sup 13}CO data. The extinction maps also allowed us to probe into the reddening law over the Circinus cloud. We found that there is a clear change in dust properties in the densest regions of Circinus-W and Circinus-E, possibly due to grain growth in the dense cloud interior. Among the YSOs found in the literature, we attempted to infer the ages and masses of the H{alpha} emission-line stars forming in the two clumps, and found that they are likely to be younger than 1 Myr, having a relatively small mass of {approx}<2 M{sub sun} at the zero-age main sequence.

Shimoikura, Tomomi; Dobashi, Kazuhito, E-mail: ikura@u-gakugei.ac.jp [Department of Astronomy and Earth Sciences, Tokyo Gakugei University, Koganei, Tokyo 184-8501 (Japan)

2011-04-10T23:59:59.000Z

302

Page not found | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

51 - 15860 of 28,905 results. Rebate Coal Combustion By-Products (Maryland) The Department of the Environment is responsible for regulating fugitive air emissions from the...

303

The Office of Health, Safety and Security  

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

of environmentally preferable chemicals and processes. Meets monthly. Contact: Jane Powers, (202) 586-7301, Jane.Powers@hq.doe.gov. Fugitive Emissions Working Group (FEWG):...

304

Lyman-alpha Emission from Structure Formation  

E-Print Network (OSTI)

The nature of the interaction between galaxies and the intergalactic medium (IGM) is one of the most fundamental problems in astrophysics. The accretion of gas onto galaxies provides fuel for star formation, while galactic winds transform the nearby IGM in a number of ways. One exciting technique to study this gas is through the imaging of hydrogen Lyman-alpha emission. We use cosmological simulations to study the Lyman-alpha signals expected from the growth of cosmic structure from z=0-5. We show that if dust absorption is negligible, recombinations following the absorption of stellar ionizing photons dominate the total Lyman-alpha photon production rate. However, galaxies are also surrounded by "Lyman-alpha coronae" of diffuse IGM gas. These coronae are composed of a combination of accreting gas and material ejected from the central galaxy by winds. The Lyman-alpha emission from this phase is powered by a combination of gravitational processes and the photoionizing background. While the former dominates at z~0, collisional excitation following photo-heating may well dominate the total emission at higher redshifts. The central regions of these systems are dense enough to shield themselves from the metagalactic ionizing background; unfortunately, in this regime our simulations are no longer reliable. We therefore consider several scenarios for the emission from the central cores, including one in which self-shielded gas does not emit at all. We show that the combination of star formation and cooling IGM gas can explain most of the observed "Lyman-alpha blobs" at z~3, with the important exception of the largest sources. On the other hand, except under the most optimistic assumptions, cooling IGM gas cannot explain the observations on its own.

Steven Furlanetto; Joop Schaye; Volker Springel; Lars Hernquist

2004-09-29T23:59:59.000Z

305

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

306

Paducah DUF6 Conversion Facility: Record of Decision: As Published in the Federal Register  

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

54 54 Federal Register / Vol. 69, No. 143 / Tuesday, July 27, 2004 / Notices accordance with the comprehensive set of DOE requirements and applicable regulatory requirements that have been established to protect public health and the environment. These requirements encompass a wide variety of areas, including radiation protection, facility design criteria, fire protection, emergency preparedness and response, and operational safety requirements. * Cylinder management activities will be conducted in accordance with applicable DOE safety and environmental requirements, including the Cylinder Management Plan. * Temporary impacts on air quality from fugitive dust emissions during reconstruction of cylinder yards or construction of any new facility will be controlled by the best available

307

A RESOLVED MILLIMETER EMISSION BELT IN THE AU Mic DEBRIS DISK  

SciTech Connect

We present imaging observations at 1.3 mm of the debris disk surrounding the nearby M-type flare star AU Mic with beam size 3'' (30 AU) from the Submillimeter Array. These data reveal a belt of thermal dust emission surrounding the star with the same edge-on geometry as the more extended scattered light disk detected at optical wavelengths. Simple modeling indicates a central radius of {approx}35 AU for the emission belt. This location is consistent with the reservoir of planetesimals previously invoked to explain the shape of the scattered light surface brightness profile through size-dependent dust dynamics. The identification of this belt further strengthens the kinship between the debris disks around AU Mic and its more massive sister star {beta} Pic, members of the same {approx}10 Myr old moving group.

Wilner, David J.; Andrews, Sean M.; MacGregor, Meredith A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Meredith Hughes, A. [Department of Astronomy, 601 Campbell Hall, University of California, Berkeley, CA 94720 (United States)

2012-04-20T23:59:59.000Z

308

Phyllosilicate Emission from Protoplanetary Disks: Is the Indirect Detection of Extrasolar Water Possible?  

E-Print Network (OSTI)

Phyllosilicates are hydrous minerals formed by interaction between rock and liquid water and are commonly found in meteorites originating in the asteroid belt. Collisions between asteroids contribute to zodiacal dust, which therefore reasonably could include phyllosilicates. Collisions between planetesimals in protoplanetary disks may also produce dust containing phyllosilicates. These minerals possess characteristic emission features in the mid-infrared and could be detectable in extrasolar protoplanetary disks. Here we determine whether phyllosilicates in protoplanetary disks are detectable in the infrared using instruments such as those on board the Spitzer Space Telescope and SOFIA (Stratospheric Observatory for Infrared Astronomy). We calculate opacities for the phyllosilicates most common in meteorites and compute the emission of radiation from a protoplanetary disk using a 2-layer radiative transfer model. We find that phyllosilicates present at the 3% level lead to observationally significant differen...

Morris, Melissa A; 10.1089/ast.2008.0316

2013-01-01T23:59:59.000Z

309

Dust Motions Driven by MHD Turbulence  

E-Print Network (OSTI)

We discuss the relative grain motions due to MHD turbulence in interstellar medium. It has been known for decades that turbulent drag is an efficient way to induce grain relative motions. However, earlier treatments disregarded magnetic field and used Kolmogorov turbulence. Unlike hydro turbulence, MHD turbulence is anisotropic on small scales. Moreover, compressible modes are important for MHD and magnetic perturbations can directly interact with grains. We provide calculations of grain relative motion for realistic interstellar turbulence driving that is consistent with the velocity dispersions observed in diffuse gas and for realistic grain charging. We account for the turbulence cutoff arising from abmipolar drag. Our results on grain shattering are consistent with the customary accepted cutoff size. We obtain grain velocities for turbulence with parameters consistent with those in HI and dark clouds. These velocities are smaller than those in earlier papers, where MHD effects were disregarded. Finally, we consider grain velocities arising from photoelectric emission, radiation pressure and the thrust due to molecular hydrogen formation. These are lower than relative velocities induced by turbulence. We conclude that turbulence should prevent these mechanisms from segregating grains by size.

A. Lazarian; Huirong Yan

2002-05-17T23:59:59.000Z

310

Galactic Diffuse Emissions  

DOE Green Energy (OSTI)

Interactions of cosmic rays with interstellar nucleons and photons make the Milky Way a bright, diffuse source of high-energy {gamma}-rays. Observationally, the results from EGRET, COMPTEL, and OSSE have now been extended to higher energies by ground-based experiments, with detections of diffuse emission in the Galactic center reported by H.E.S.S. in the range above 100 GeV and of diffuse emission in Cygnus by MILAGRO in the TeV range. In the range above 100 keV, INTEGRAL SPI has found that diffuse emission remains after point sources are accounted for. I will summarize current knowledge of diffuse {gamma}-ray emission from the Milky Way and review some open issues related to the diffuse emission -- some old, like the distribution of cosmic-ray sources and the origin of the 'excess' of GeV emission observed by EGRET, and some recently recognized, like the amount and distribution of molecular hydrogen not traced by CO emission -- and anticipate some of the advances that will be possible with the Large Area Telescope on GLAST. We plan to develop an accurate physical model for the diffuse emission, which will be useful for detecting and accurately characterizing emission from Galactic point sources as well as any Galactic diffuse emission from exotic processes, and for studying the unresolved extragalactic emission.

Digel, Seth W.; /SLAC

2007-10-25T23:59:59.000Z

311

State Emissions Estimates  

Gasoline and Diesel Fuel Update (EIA)

Estimates of state energy-related carbon dioxide emissions Estimates of state energy-related carbon dioxide emissions Because energy-related carbon dioxide (CO 2 ) constitutes over 80 percent of total emissions, the state energy-related CO 2 emission levels provide a good indicator of the relative contribution of individual states to total greenhouse gas emissions. The U.S. Energy Information Administration (EIA) emissions estimates at the state level for energy-related CO 2 are based on data contained in the State Energy Data System (SEDS). 1 The state-level emissions estimates are based on energy consumption data for the following fuel categories: three categories of coal (residential/commercial, industrial, and electric power sector); natural gas; and ten petroleum products including-- asphalt and road oil, aviation gasoline, distillate fuel, jet fuel, kerosene, liquefied petroleum gases

312

Airborne Sunphotometry and Integrated Analyses of Dust, Other Aerosols, and Water Vapor in the Puerto Rico Dust Experiment (PRIDE)  

E-Print Network (OSTI)

in the Puerto Rico Dust Experiment (PRIDE) PI: Philip B. Russell MS 245-5, NASA Ames Research Center Moffett new analyses of aerosol radiative forcing sensitivity, single scattering albedo, and the solar spectral radiative energy budget. (h) Derive aerosol size distributions from optical depth and extinction

313

Low Emissions Aftertreatment and Diesel Emissions Reduction  

Science Conference Proceedings (OSTI)

Detroit Diesel Corporation (DDC) has successfully completed a five-year Low Emissions Aftertreatment and Diesel Emissions Reduction (LEADER) program under a DOE project entitled: ''Research and Development for Compression-Ignition Direct-Injection Engines (CIDI) and Aftertreatment Sub-Systems''. The objectives of the LEADER Program were to: Demonstrate technologies that will achieve future federal Tier 2 emissions targets; and Demonstrate production-viable technical targets for engine out emissions, efficiency, power density, noise, durability, production cost, aftertreatment volume and weight. These objectives were successfully met during the course of the LEADER program The most noteworthy achievements in this program are listed below: (1) Demonstrated Tier 2 Bin 3 emissions target over the FTP75 cycle on a PNGV-mule Neon passenger car, utilizing a CSF + SCR system These aggressive emissions were obtained with no ammonia (NH{sub 3}) slip and a combined fuel economy of 63 miles per gallon, integrating FTP75 and highway fuel economy transient cycle test results. Demonstrated feasibility to achieve Tier 2 Bin 8 emissions levels without active NOx aftertreatment. (2) Demonstrated Tier 2 Bin 3 emissions target over the FTP75 cycle on a light-duty truck utilizing a CSF + SCR system, synergizing efforts with the DOE-DDC DELTA program. This aggressive reduction in tailpipe out emissions was achieved with no ammonia slip and a 41% fuel economy improvement, compared to the equivalent gasoline engine-equipped vehicle. (3) Demonstrated Tier 2 near-Bin 9 emissions compliance on a light-duty truck, without active NOx aftertreatment devices, in synergy with the DOE-DDC DELTA program. (4) Developed and applied advanced combustion technologies such as ''CLEAN Combustion{copyright}'', which yields simultaneous reduction in engine out NOx and PM emissions while also improving engine and aftertreatment integration by providing favorable exhaust species and temperature characteristics. These favorable emissions characteristics were obtained while maintaining performance and fuel economy. These aggressive emissions and performance results were achieved by applying a robust systems technology development methodology. This systems approach benefits substantially from an integrated experimental and analytical approach to technology development, which is one of DDCs core competencies Also, DDC is uniquely positioned to undertake such a systems technology development approach, given its vertically integrated commercial structure within the DaimlerChrysler organization. State-of-the-art analytical tools were developed targeting specific LEADER program objectives and were applied to guide system enhancements and to provide testing directions, resulting in a shortened and efficient development cycle. Application examples include ammonia/NO{sub x} distribution improvement and urea injection controls development, and were key contributors to significantly reduce engine out as well as tailpipe out emissions. Successful cooperation between DDC and Engelhard Corporation, the major subcontractor for the LEADER program and provider of state-of-the-art technologies on various catalysts, was another contributing factor to ensure that both passenger car and LD truck applications achieved Tier 2 Bin 3 emissions levels. Significant technical challenges, which highlight barriers of commercialization of diesel technology for passenger cars and LD truck applications, are presented at the end of this report.

None

2005-05-27T23:59:59.000Z

314

STANDARDS CONTROLLING AIR EMISSIONS FOR THE SOIL DESICCATION PILOT TEST  

Science Conference Proceedings (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

315

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

SciTech Connect

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

316

Dust Deserves More than the Brush-Off | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Dust Deserves More than the Brush-Off Dust Deserves More than the Brush-Off Dust Deserves More than the Brush-Off July 6, 2012 - 10:35am Addthis The dust particles act as a "heat pump" drawing heat from the sun and surface, and attracting moisture from the Gulf of California and the Gulf of Mexico. Without dust, rainfall would be up to 40 percent less over Arizona, New Mexico and Texas. | Creative Commons photo by Jared The dust particles act as a "heat pump" drawing heat from the sun and surface, and attracting moisture from the Gulf of California and the Gulf of Mexico. Without dust, rainfall would be up to 40 percent less over Arizona, New Mexico and Texas. | Creative Commons photo by Jared

317

Dust-acoustic shock formation in adiabatic hot dusty plasmas with variable charge  

Science Conference Proceedings (OSTI)

Shocklike structure can be formed after a certain transient time due to the self-steepening of the negative potential. In order to have a monotonic or oscillatory shock wave, it is known that a source of dissipation is needed. In this study, we considered the variation of dust charge as a source of dissipation. By using the reductive perturbation technique, the nonlinear Burgers equation is derived and the shocklike solution is determined. The effects of dust temperature on different characteristics of dust-acoustic shock structure are discussed. It is found out that the dust thickness is not affected by dust temperature. By considering a dusty plasma system with a set of parameters, it is shown that there exists a specific dust critical temperature T{sub dc} which gives maximum height for the dust-acoustic shock structure. The effects of the plasma species temperature on shock formation are also investigated.

Asgari, H.; Muniandy, S. V.; Wong, C. S. [Department of Physics, Plasma Research Laboratory, University of Malaya, 50603 Kuala Lumpur (Malaysia)

2011-01-15T23:59:59.000Z

318

Lyman-alpha Emission from Structure Formation  

E-Print Network (OSTI)

The nature of the interaction between galaxies and the intergalactic medium (IGM) is one of the most fundamental problems in astrophysics. The accretion of gas onto galaxies provides fuel for star formation, while galactic winds transform the nearby IGM in a number of ways. One exciting technique to study this gas is through the imaging of hydrogen Lyman-alpha emission. We use cosmological simulations to study the Lyman-alpha signals expected from the growth of cosmic structure from z=0-5. We show that if dust absorption is negligible, recombinations following the absorption of stellar ionizing photons dominate the total Lyman-alpha photon production rate. However, galaxies are also surrounded by "Lyman-alpha coronae" of diffuse IGM gas. These coronae are composed of a combination of accreting gas and material ejected from the central galaxy by winds. The Lyman-alpha emission from this phase is powered by a combination of gravitational processes and the photoionizing background. While the former dominates at ...

Furlanetto, S; Springel, V; Hernquist, L; Furlanetto, Steven; Schaye, Joop; Springel, Volker; Hernquist, Lars

2004-01-01T23:59:59.000Z

319

Carbon Emissions: Paper Industry  

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

Paper Industry Paper Industry Carbon Emissions in the Paper Industry The Industry at a Glance, 1994 (SIC Code: 26) Total Energy-Related Emissions: 31.6 million metric tons of carbon (MMTC) -- Pct. of All Manufacturers: 8.5% Total First Use of Energy: 2,665 trillion Btu -- Pct. of All Manufacturers: 12.3% -- Pct. Renewable Energy: 47.7% Carbon Intensity: 11.88 MMTC per quadrillion Btu Renewable Energy Sources (no net emissions): -- Pulping liquor: 882 trillion Btu -- Wood chips and bark: 389 trillion Btu Energy Information Administration, "1994 Manufacturing Energy Consumption Survey" and Emissions of Greenhouse Gases in the United States 1998 Energy-Related Carbon Emissions, 1994 Source of Carbon Carbon Emissions (million metric tons) All Energy Sources 31.6 Net Electricity 11.0

320

Carbon Emissions: Food Industry  

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

Food Industry Food Industry Carbon Emissions in the Food Industry The Industry at a Glance, 1994 (SIC Code: 20) Total Energy-Related Emissions: 24.4 million metric tons of carbon (MMTC) -- Pct. of All Manufacturers: 6.6% Total First Use of Energy: 1,193 trillion Btu -- Pct. of All Manufacturers: 5.5% Carbon Intensity: 20.44 MMTC per quadrillion Btu Energy Information Administration, "1994 Manufacturing Energy Consumption Survey" and Emissions of Greenhouse Gases in the United States 1998 Energy-Related Carbon Emissions, 1994 Source of Carbon Carbon Emissions (million metric tons) All Energy Sources 24.4 Net Electricity 9.8 Natural Gas 9.1 Coal 4.2 All Other Sources 1.3 Energy Information Administration, "1994 Manufacturing Energy Consumption Survey" and Emissions of Greenhouse Gases in the United States 1998

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

Carbon Emissions: Chemicals Industry  

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

Chemicals Industry Chemicals Industry Carbon Emissions in the Chemicals Industry The Industry at a Glance, 1994 (SIC Code: 28) Total Energy-Related Emissions: 78.3 million metric tons of carbon (MMTC) -- Pct. of All Manufacturers: 21.1% -- Nonfuel Emissions: 12.0 MMTC Total First Use of Energy: 5,328 trillion Btu -- Pct. of All Manufacturers: 24.6% Energy Sources Used As Feedstocks: 2,297 trillion Btu -- LPG: 1,365 trillion Btu -- Natural Gas: 674 trillion Btu Carbon Intensity: 14.70 MMTC per quadrillion Btu Energy Information Administration, "1994 Manufacturing Energy Consumption Survey" and Emissions of Greenhouse Gases in the United States 1998 Energy-Related Carbon Emissions, 1994 Source of Carbon Carbon Emissions (million metric tons) All Energy Sources 78.3 Natural Gas 32.1

322

NETL: Mercury Emissions Control  

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

Home > Technologies > Coal & Power Systems > Innovations for Existing Plants > Mercury Emissions Control Home > Technologies > Coal & Power Systems > Innovations for Existing Plants > Mercury Emissions Control Innovations for Existing Plants Mercury Emissions Control NETL managed the largest funded research program in the country to develop an in-depth understanding of fossil combustion-based mercury emissions. The program goal was to develop effective control options that would allow generators to comply with regulations. Research focus areas included measurement and characterization of mercury emissions, as well as the development of cost-effective control technologies for the U.S. coal-fired electric generating industry. Control Technologies Field Testing Phase I & II Phase III Novel Concepts APCD Co-benefits Emissions Characterization

323

emissions | OpenEI  

Open Energy Info (EERE)

emissions emissions Dataset Summary Description The New Zealand Ministry of Economic Development publishes an annual Energy Outlook, which presents projections of New Zealand's future energy supply, demand, prices and greenhouse gas emissions. The principle aim of these projections is to inform the national energy debate. Included here are the model results for emissions. The spreadsheet provides an interactive tool for selecting which model results to view, and which scenarios to evaluate; full model results for each scenario are also included. Source New Zealand Ministry of Economic Development Date Released Unknown Date Updated December 15th, 2010 (4 years ago) Keywords emissions New Zealand projections Data application/vnd.ms-excel icon 2010 New Zealand emissions outlook (xls, 1.2 MiB)

324

Reducing Diesel Engine Emissions  

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

Reducing Reducing Diesel Engine Emissions 2 0 1 0 Green TransporTaTion TechnoloGies Compared to traditional gasoline engines, diesel engines require less maintenance, generate energy more efficiently, and produce less carbon dioxide emissions. But when uncontrolled, diesel engines churn out harmful emissions like particu- late matter (PM) and nitrogen oxides (NO x ). Researchers at Argonne National Laboratory are currently working to develop

325

Mercury Emissions Data Analyses  

Science Conference Proceedings (OSTI)

This report contains the visual materials included in presentations given at Research Triangle Park, North Carolina on April 3, 2002. Participants included representatives from EPRI, DOE, RMB Consulting & Research, and EERC. The MACT Working Group gave a presentation on "Variability in Hg Emissions Based on SCEM Data." The visuals in the report are a set of graphs documenting results of mercury emissions over time, using semi-continuous emissions monitor (SCEM) data. The EPA Utility Working Group gave a ...

2002-05-02T23:59:59.000Z

326

Greenhouse Gas Emission Measurements  

Science Conference Proceedings (OSTI)

... climate change as a serious problem and that greenhouse gas (GHG ... models to determine the baselines of GHG emissions and the effect of GHG ...

2010-10-05T23:59:59.000Z

327

SF6 Emissions Overview  

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

SF 6 Emissions Overview Joanna Eckstein and Penny Avery Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned...

328

Greenhouse Gas Emissions  

Science Conference Proceedings (OSTI)

Others wanting to learn more about greenhouse gas emissions and their reduction. About the ... based on ensuring the sustainability of finite natural resources.

329

NETL: Emissions Characterization - CMU Emissions Characterization Study  

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

Source Emissions Characterization Study Source Emissions Characterization Study The emissions characterization study is being performed in conjunction with the Pittsburgh Air Quality Study [PDF-744KB], a larger effort that includes ambient measurements and atmospheric modeling of the Pittsburgh region. The main objectives of this portion of the study are: To achieve advanced characterization of the PM in the Pittsburgh region. Measurements include the PM size, surface, volume, and mass distribution; chemical composition as a function of size and on a single particle basis; temporal and spatial variability. To obtain accurate current fingerprints of the major primary PM sources in the Pittsburgh region using traditional filter-based sampling and state-of-the-art techniques such as dilution sampling and single particle analysis using mass spectroscopy and LIBS.

330

Effects of polarization force and effective dust temperature on dust-acoustic solitary and shock waves in a strongly coupled dusty plasma  

Science Conference Proceedings (OSTI)

A strongly coupled dusty plasma containing strongly correlated negatively charged dust grains and weakly correlated (Maxwellian) electrons and ions has been considered. The effects of polarization force (which arises due to the interaction between thermal ions and highly negatively charged dust grains) and effective dust temperature (which arises from the electrostatic interactions among highly negatively charged dust and from the dust thermal pressure) on the dust-acoustic (DA) solitary and shock waves propagating in such a strongly coupled dusty plasma are taken into account. The DA solitary and shock waves are found to exist with negative potential only. It has been shown that the strong correlation among the charged dust grains is a source of dissipation and is responsible for the formation of the DA shock waves. It has also been shown that the effects of polarization force and effective dust-temperature significantly modify the basic features (e.g., amplitude, width, and speed) of the DA solitary and shock waves. It has been suggested that a laboratory experiment be performed to test the theory presented in this work.

Mamun, A. A.; Ashrafi, K. S.; Shukla, P. K. [Department of Physics, Jahangirnagar University, Savar, Dhaka 1342 (Bangladesh); RUB International Chair, International Centre for Advanced Studies in Physical Sciences, Faculty of Physics and Astronomy, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany)

2010-08-15T23:59:59.000Z

331

Effect of Direct Radiative Forcing of Asian Dust on the Meteorological Fields in East Asia during an Asian Dust Event Period  

Science Conference Proceedings (OSTI)

Coupled and noncoupled models in a grid of 60 × 60 km2 in the eastern Asian domain have been employed to examine the effect of the direct radiative forcing of the Asian dust aerosol on meteorological fields for an intense Asian dust event ...

Hyun-Ju Ahn; Soon-Ung Park; Lim-Seok Chang

2007-10-01T23:59:59.000Z

332

Canadian House Dust Study: Lead Bioaccessibility and Speciation  

Science Conference Proceedings (OSTI)

Vacuum samples were collected from 1025 randomly selected urban Canadian homes to investigate bioaccessible Pb (Pb{sub S}) concentrations in settled house dust. Results indicate a polymodal frequency distribution, consisting of three lognormally distributed subpopulations defined as 'urban background' (geomean 58 {micro}g g{sup -1}), 'elevated' (geomean 447 {micro}g g{sup -1}), and 'anomalous' (geomean 1730 {micro}g g{sup -1}). Dust Pb{sub S} concentrations in 924 homes (90%) fall into the 'urban background' category. The elevated and anomalous subpopulations predominantly consist of older homes located in central core areas of cities. The influence of house age is evidenced by a moderate correlation between house age and dust Pb{sub S} content (R{sup 2} = 0.34; n = 1025; p < 0.01), but it is notable that more than 10% of homes in the elevated/anomalous category were built after 1980. Conversely, the benefit of home remediation is evidenced by the large number of homes (33%) in the background category that were built before 1960. The dominant dust Pb species determined using X-ray Absorption Spectroscopy were as follows: Pb carbonate, Pb hydroxyl carbonate, Pb sulfate, Pb chromate, Pb oxide, Pb citrate, Pb metal, Pb adsorbed to Fe- and Al-oxyhydroxides, and Pb adsorbed to humate. Pb bioaccessibility estimated from solid phase speciation predicts Pb bioaccessibility measured using a simulated gastric extraction (R{sup 2} = 0.85; n = 12; p < 0.0001). The trend toward increased Pb bioaccessibility in the elevated and anomalous subpopulations (75% {+-} 18% and 81% {+-} 8%, respectively) compared to background (63% {+-} 18%) is explained by the higher proportion of bioaccessible compounds used as pigments in older paints (Pb carbonate and Pb hydroxyl carbonate). This population-based study provides a nationally representative urban baseline for applications in human health risk assessment and risk management.

P Rasmussen; S Beauchemin; M Chenier; C Levesque; L MacLean; L Marrow; H Jones-Otazo; S Petrovic; L McDonald; H Gardner

2011-12-31T23:59:59.000Z

333

Dust Static Spherically Symmetric Solution in $f(R)$ Gravity  

E-Print Network (OSTI)

In this paper, we take dust matter and investigate static spherically symmetric solution of the field equations in metric f(R) gravity. The solution is found with constant Ricci scalar curvature and its energy distribution is evaluated by using Landau-Lifshitz energy-momentum complex. We also discuss the stability condition and constant scalar curvature condition for some specific popular choices of f(R) models in addition to their energy distribution.

Muhammad Sharif; Hafiza Rizwana Kausar

2011-02-21T23:59:59.000Z

334

Carbon formation and metal dusting in advanced coal gasification processes  

SciTech Connect

The product gases generated by coal gasification systems contain high concentrations of CO and, characteristically, have relatively high carbon activities. Accordingly, carbon deposition and metal dusting can potentially degrade the operation of such gasifier systems. Therefore, the product gas compositions of eight representative gasifier systems were examined with respect to the carbon activity of the gases at temperatures ranging from 480 to 1,090 C. Phase stability calculations indicated that Fe{sub 3}C is stable only under very limited thermodynamic conditions and with certain kinetic assumptions and that FeO and Fe{sub 0.877}S tend to form instead of the carbide. As formation of Fe{sub 3}C is a necessary step in the metal dusting of steels, there are numerous gasifier environments where this type of carbon-related degradation will not occur, particularly under conditions associated with higher oxygen and sulfur activities. These calculations also indicated that the removal of H{sub 2}S by a hot-gas cleanup system may have less effect on the formation of Fe{sub 3}C in air-blown gasifier environments, where the iron oxide phase can exist and is unaffected by the removal of sulfur, than in oxygen-blown systems, where iron sulfide provides the only potential barrier to Fe{sub 3}C formation. Use of carbon- and/or low-alloy steels dictates that the process gas composition be such that Fe{sub 3}C cannot form if the potential for metal dusting is to be eliminated. Alternatively, process modifications could include the reintroduction of hydrogen sulfide, cooling the gas to perhaps as low as 400 C and/or steam injection. If higher-alloy steels are used, a hydrogen sulfide-free gas may be processed without concern about carbon deposition and metal dusting.

DeVan, J.H.; Tortorelli, P.F.; Judkins, R.R.; Wright, I.G.

1997-02-01T23:59:59.000Z

335

The Use of Oil Refinery Wastes as a Dust Suppression Surfactant for Use in Mining  

Science Conference Proceedings (OSTI)

In this research, the suitability of a selection of petroleum refinery wastes as a dust suppressant were examined. Dust is a significant problem in surface and underground mining mainly because of its adverse effects on human health and machinery. Hence, dust control and suppression is a vital part of mine planning for mining engineers. Water is the oldest and the cheapest suppressant in dealing with the mine dusts. However, surfactant use has recently been used for a wider range of applications in the mining industry. In order to carry out laboratory experiments, a dust chamber was designed and manufactured. The chamber has an inlet for coal dust entrance and a nozzle for spraying water and the oil refinery wastes. Water and the surfactants were mixed at various ratios and then sprayed onto the coal dusts within the cell. Dust concentration was measured systematically to determine the effects of surfactant containing solution on the coal dust and the data obtained by the measurements were analyzed. The results showed that the oil refinery wastes could be used as a dust suppressant, which may create an economical utilization for the wastes concerned.

Dixon-Hardy, D.W.; Beyhan, S.; Ediz, I.G.; Erarslan, K. [University of Leeds, Leeds (United Kingdom)

2008-10-15T23:59:59.000Z

336

GRAIN SORTING IN COMETARY DUST FROM THE OUTER SOLAR NEBULA  

SciTech Connect

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

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

2012-12-01T23:59:59.000Z

337

Catalysts for Lean Engine Emission Control - Emissions & Emission Controls  

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

Catalysts for Lean Engine Emission Control Catalysts for Lean Engine Emission Control Catalysts for controlling NOx from lean engines are studied in great detail at FEERC. Lean NOx Traps (LNTs) and Selective Catalytic Reduction (SCR) are two catalyst technologies of interest. Catalysts are studied from the nanoscale to full scale. On the nanoscale, catalyst powders are analyzed with chemisorptions techniques to determine the active metal surface area where catalysis occurs. Diffuse Reflectance Infrared Fourier Transform (DRIFT) spectroscopy is used to observe the chemical reactions occurring on the catalyst surface during catalyst operation. Both powder and coated catalyst samples are analyzed on bench flow reactors in controlled simulated exhaust environments to better characterize the chemical

338

Air Emission Inventory for the INEEL -- 1999 Emission Report  

Science Conference Proceedings (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

339

Low intensity dust ion-acoustic shock waves due to dust charge fluctuation in a nonextensive dusty plasma  

SciTech Connect

The properties of low intensity dust ion acoustic shock waves are studied in a charge varying dusty plasma with nonextensive electrons. Owing to the departure from the Maxwellian electron distribution to a nonextensive one, the modified electrostatic charging of a spherical dust particle in plasma with ion streaming speed is considered. Based on the weakly nonlinear analysis, a new relationship between the low intensity localized disturbances and nonextensive electrons is derived. It is found that both strength and steepness of shock structures arise as the electrons evolve far from their thermodynamic equilibrium in such plasma with parameter ranges corresponding to Saturn's rings. It is also shown that the ion temperature and population of electrons reduce the possibility of the formation of the shock profile.

Alinejad, H. [Department of Physics, Faculty of Basic Science, Babol University of Technology, Babol 47148-71167 (Iran, Islamic Republic of); Shahmansory, M. [Department of Physics, Faculty of Science, Arak University, Arak 38156-8-8349 (Iran, Islamic Republic of)

2012-08-15T23:59:59.000Z

340

The collision effect between dust grains and ions to the dust ion acoustic waves in a dusty plasma  

Science Conference Proceedings (OSTI)

Damping solitary wave in dusty plasma is studied by considering the collision effect between dust grains and ions. It can be described by a KdV type equation in which a damping term of {phi}{sup 2} exist. It is found that both the amplitude and propagation velocity of the solitary wave decrease with time exponentially. Our results are compared with another KdV type equation with the damping term of {phi}. It is noted that the damping rate of the KdV type equation with the damping term of {phi}{sup 2} is larger than that with the term of {phi}. It is found that the damping rate is proportional to the collision frequency between dust grains and ions.

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

2012-10-15T23:59:59.000Z

Note: This page contains sample records for the topic "fugitive dust emissions" from the National Library of EnergyBeta (NLEBeta).
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341

Emission properties of explosive field emission cathodes  

Science Conference Proceedings (OSTI)

The research results of the explosive field emission cathode plasma expansion velocity and the initial emission area in the planar diode configuration with cathodes made of graphite, stainless steel, polymer velvet, carbon coated, and carbon fiber (needle type) cathodes are presented. The experiments have been performed at the electron accelerator LIA-200 (200 kV, 100 ns, and 4 kA). The diode voltage has been varied from 28-225 kV, whereas the current density has been varied from 86-928 A/cm{sup 2} with 100 ns pulse duration. The experimentally obtained electron beam diode perveance has been compared with the 1 dimensional Child-Langmuir- law. It was found that initially only a part of the cathode take part in the emission process. The plasma expands at 1.7-5.2 cm/{mu}s for 4 mm anode-cathode gap for various cathode materials. It was found that the plasma expansion velocity increases with the decrease in the cathode diameter. At the beginning of the accelerating pulse, the entire cathode area participates in the electron emission process only for the multiple needle type carbon fiber cathode.

Roy, Amitava; Patel, Ankur; Menon, Rakhee; Sharma, Archana; Chakravarthy, D. P. [Accelerator and Pulse Power Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Patil, D. S. [Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

2011-10-15T23:59:59.000Z

342

NETL: IEP - Mercury Emissions Control: Emissions Characterization  

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

Control Control Emissions Characterization In anticipation of the 1990 CAAAs, specifically the draft Title III regarding the characterization of potential HAPs from electric steam generating units, DOE initiated a new Air Toxics Program in 1989. The DOE Mercury Measurement and Control Program evolved as a result of the findings from the comprehensive assessment of hazardous air pollutants studies conducted by DOE from 1990 through 1997. DOE, in collaboration with EPRI, performed stack tests at a number of coal-fired power plants (identified on map below) to accurately determine the emission rates of a series of potentially toxic chemicals. These tests had not been conducted previously because of their cost, about $1 million per test, so conventional wisdom on emissions was based on emission factors derived from analyses of coal. In general, actual emissions were found to be about one-tenth previous estimates, due to a high fraction of the pollutants being captured by existing particulate control systems. These data resulted in a decision by EPA that most of these pollutants were not a threat to the environment, and needed no further regulation at power plants. This shielded the coal-fired power industry from major (tens of millions) costs that would have resulted from further controlling these emissions. However, another finding of these studies was that mercury was not effectively controlled in coal-fired utility boiler systems. Moreover, EPA concluded that a plausible link exists between these emissions and adverse health effects. Ineffective control of mercury by existing control technologies resulted from a number of factors, including variation in coal composition and variability in the form of the mercury in flue gases. The volatility of mercury was the main contributor for less removal, as compared to the less volatile trace elements/metals which were being removed at efficiencies over 99% with the fly ash. In addition, it was determined that there was no reliable mercury speciation method to accurately distinguish between the elemental and oxidized forms of mercury in the flue gas. These two forms of mercury respond differently to removal techniques in existing air pollution control devices utilized by the coal-fired utility industry.

343

Polycyclic aromatic hydrocarbon emission profiles and removal efficiency by electrostatic precipitator and wetfine scrubber in an iron ore sintering plant  

Science Conference Proceedings (OSTI)

A monitoring campaign of polychlorinated dibenzo-p-dioxins and dibenzofurans, polyaromatic hydrocarbons (PAHs), and polychlorinated biphenyl was carried out in an Italian iron ore sintering plant by sampling the combustion gases at the electrostatic precipitator (ESP) outlet, at the Wetfine scrubber (WS) outlet, and by collecting the ESP dust. Few data are available on these micropollutants produced in iron ore sintering plants, particularly from Italian plants. This study investigates the PAH emission profiles and the removal efficiency of ESPs and WS. PAHs were determined at the stack, ESP outlet flue gases, and in ESP dust to characterize the emission profiles and the performance of the ESP and the WS for reducing PAH emission. The 11 PAHs monitored are listed in the Italian legislative decree 152/2006. The mean total PAH sum concentration in the stack flue gases is 3.96 {mu}g/N m{sup 3}, in ESP outlet flue gases is 9.73 {mu}g/N m{sup 3}, and in ESP dust is 0.53 {mu}g/g. Regarding the emission profiles, the most abundant compound is benzo(b)fluoranthene, which has a relative low BaP toxic equivalency factors (TEF) value, followed by dibenzo(a,l)pyrene, which has a very high BaP(TEF) value. The emission profiles in ESP dust and in the flue gases after the ESP show some changes, whereas the fingerprint in ESP and stack flue gases is very similar. The removal efficiency of the ESP and of WS on the total PAH concentration is 5.2 and 59.5%, respectively. 2 figs., 5 tabs.

Ettore Guerriero; Antonina Lutri; Rosanna Mabilia; Maria Concetta Tomasi Sciano; Mauro Rotatori [Istituto sull'Inquinamento Atmosferico, Monterotondo Scalo (Italy). Consiglio Nazionale delle Ricerche

2008-11-15T23:59:59.000Z

344

THE IMPACT OF SHRINKING HANFORD BOUNDARIES ON PERMITS FOR TOXIC AIR POLLUTANT EMISSIONS FROM THE HANFORD 200 WEST AREA  

DOE Green Energy (OSTI)

This presentation (CE-580. Graduate Seminar) presents a brief description of an approach to use a simpler dispersion modeling method (SCREEN3) in conjunction with joint frequency tables for Hanford wind conditions to evaluate the impacts of shrinking the Hanford boundaries on the current permits for facilities in the 200 West Area. To fulfill requirements for the graduate student project (CE-702. Master's Special Problems), this evaluation will be completed and published over the next two years. Air toxic emissions play an important role in environmental quality and require a state approved permit. One example relates to containers or waste that are designated as Transuranic Waste (TRU), which are required to have venting devices due to hydrogen generation. The Washington State Department of Ecology (Ecology) determined that the filters used did not meet the definition of a ''pressure relief device'' and that a permit application would have to be submitted by the Central Waste Complex (CWC) for criteria pollutant and toxic air pollutant (TAP) emissions in accordance with Washington Administrative Code (WAC) 173-400 and 173-460. The permit application submitted in 2000 to Ecology used Industrial Source Code III (ISCIII) dispersion modeling to demonstrate that it was not possible for CWC to release a sufficient quantity of fugitive Toxic Air Pollutant emissions that could exceed the Acceptable Source Impact Levels (ASILs) at the Hanford Site Boundary. The modeled emission rates were based on the diurnal breathing in and out through the vented drums (approximately 20% of the drums), using published vapor pressure, molecular weight, and specific gravity data for all 600+ compounds, with a conservative estimate of one exchange volume per day (208 liters per drum). Two permit applications were submitted also to Ecology for the Waste Receiving and Processing Facility and the T Plant Complex. Both permit applications were based on the Central Waste Complex approach, and relied on similar tracking requirements as at CWC. All three applications used ISCIII modeling, where unit release factors (lb/yr converted to g/s) were determined for estimating the highest 24-hr or annual average concentrations (in {micro}g/m{sup 3}), where the nearest public receptor was roughly 20 miles away. Plans to clean up and release portions of the Hanford Site over the next several decades would allow public access closer to these facilities in the 200 West Area. Before release of these areas, effectively shrinking the boundaries, the three permits would have to be re-evaluated to determine if toxic air pollutant emissions would remain below the ASILs if the restricted boundaries are moved closer than the current locations.

JOHNSON, R.E.

2005-11-09T23:59:59.000Z

345

3D Lya radiation transfer. II. Fitting the Lyman break galaxy MS 1512-cB58 and implications for Lya emission in high-z starbursts  

E-Print Network (OSTI)

Using our 3D Lya radiation transfer code, we compute the radiation transfer of Lya and UV continuum photons including dust. Observational constraints on the neutral gas (column density, kinematics, etc.) are taken from other analysis of this object. RESULTS: The observed Lya profile of MS 1512--cB58 is reproduced for the first time taking radiation transfer and all observational constraints into account. The observed absorption profile is found to result naturally from the observed amount of dust and the relatively high HI column density. Radiation transfer effects and suppresion by dust transform a strong intrinsic Lya emission with EW(Lya)>~ 60 Ang into the observed faint superposed Lya emission peak. We propose that the vast majority of LBGs have intrinsically EW(Lya)~60-80 Ang or larger, and that the main physical parameter responsible for the observed variety of Lya strengths and profiles in LBGs is N_H and the accompanying variation of the dust content. Observed EW(Lya) distributions, Lya luminosity functions, and related quantities must therefore be corrected for radiation transfer and dust effects. The implications from our scenario on the duty-cycle of Lya emitters are also discussed.

Daniel Schaerer; Anne Verhamme

2008-01-08T23:59:59.000Z

346

Modeling of Particulate Matter Emissions from Agricultural Operations  

E-Print Network (OSTI)

State Air Pollution Regulation Agencies (SAPRAs) issue and enforce permits that limit particulate matter emissions from all sources including layer and broiler facilities, cattle feedyards, dairies, cotton gins, and grain elevators. In this research, a process was developed to determine distances from emitting sources to where the estimated concentrations were less than the National Ambient Air Quality Standards (NAAQS). These distances are a function of emission rates and meteorological conditions. Different protocols were used to develop emission factors for cattle feedyards and layer houses. Dispersion modeling with American Meteorological Society/Environmental Protection Agency Regulatory Model (AERMOD) was conducted to determine the emissions of particulate matter. These data were used to determine the distances from the sources to where the concentrations of particulate matter (PM) would be less than the NAAQS. The current air-permitting process requires that concentrations from a source do not exceed the NAAQS at the property line and beyond for the facility to be in compliance with its permit conditions. Emission factors for particulate matter less than 10 micrometers (PM10) were developed for cattle feedyards using a reverse modeling protocol and Tapered Element Oscillating Microbalance (TEOM) sampler data. Corrections were applied to the TEOM measurements to account for TEOM vs. filter-based low-volume (FBLV) sampler bias and over-sampling of PM10 pre-collectors. Invalid concentrations and dust peaks larger than mean ± 3 times the standard deviation were excluded from this study. AERMOD predictions of downwind concentrations at cotton gins were observed for compliance with 24-hour PM10 and PM2.5 NAAQS at property lines. The emissions from three cotton gins were analyzed at 50 m and 100 m distances. TEOM and FBLV samplers were used to collect 24-hour PM10 measurements inside a laying hen house. The distances to the property lines at which the emissions of PM10 were below the 24-hour average PM10 standards were estimated using AERMOD. The results suggested that the special use of the NAAQS for as the property-line concentration not to be exceeded, could be problematic to agriculture. Emission factors that were comparable of published emission factors were obtained in this study. Large distances to property lines were required when minimum flow rate recommendations were not considered. Emission factors that are representative of the emissions in a particular facility are essential; else facilities could be inappropriately regulated.

Bairy, Jnana 1988-

2013-05-01T23:59:59.000Z

347

A dichotomy in the orientation of dust and radio jets in nearby low-power radio galaxies  

E-Print Network (OSTI)

We examine the properties of central dust in nearby quiescent and active early-type galaxies. The active galaxies are low-power radio galaxies with Fanaroff & Riley Type I or I/II radio jets. We focus on the comparison of the dust distributions in the active and quiescent galaxy samples and the relation between the radio jet and dust orientations. Our main observational conclusions are: (a) radio galaxies contain a higher fraction of regular dust 'ellipses' compared to quiescent galaxies which contain more often irregular dust distributions; (b) the morphology, size and orientation of dust ellipses and lanes in quiescent early-types and active early-types with kpc-scale radio jets is very similar; (c) dust ellipses are aligned with the major axis of the galaxy, dust lanes do not show a preferred alignment except for large (>kpc) dust lanes which are aligned with the minor axis of the galaxy. Dust morphologies can be classified as regular 'ellipses' and filamentary 'lanes'. We show that the dust ellipses are consistent with being nearly circular thin disks viewed at random viewing angles. The lanes are likely warped dust structures, which may be in the process of settling down to become regular disks or are being perturbed by a non-gravitational force. We use the observed dust-jet orientations to constrain the three-dimensional angle $\\theta_{\\rm DJ}$ between jet and dust. For dust-lane galaxies, the jet is approximately perpendicular to the dust structure, while for dust-ellipse galaxies there is a much wider distribution of $\\theta_{\\rm DJ}$. We discuss two scenarios that could explain the dust/jet/galaxy orientation dichotomy. (abridged)

Gijs Verdoes Kleijn; Tim de Zeeuw

2005-02-03T23:59:59.000Z

348

ITP Materials: Poster - Development of Materials Resistant to Metal Dusting Degradation  

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

metal dusting phenomenon metal dusting phenomenon in simulated process environments ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ ITP Materials, Sensors, and Automation, and Glass Project and Portfolio Review Meeting, June 21-24, Arlington, Virginia. K. Natesan, Z. Zeng, and D. L. Rink Energy Technology Division, Argonne National Laboratory, Argonne, Illinois, 60439 Introduction Metal dusting is a metal loss process that occurs in hot reactive gases The prerequisite for metal dusting is that carbon activity in the gas phase has to be >>1 Metal ends up as fine powder Pitting and crevice attack are common forms

349

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

350

Coal dust exposure among power station workers during normal operations at Hatfield's Ferry Power Station.  

E-Print Network (OSTI)

??Changes in coal composition could produce higher levels of coal dust exposure thanthose found in the past at Hatfield's Ferry Power Station. Air sampling was… (more)

Lewis, Christian S.

2008-01-01T23:59:59.000Z

351

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. Subject headings: astrochemistry — instrumentation: detectors — interplanetary medium — dust, extinction — meteors, meteoroids — techniques: image processing 1.

Gerardo Domínguez; Andrew J. Westphal; Mark L. F. Phillips; Steven M. Jones

2003-01-01T23:59:59.000Z

352

CO2 Emissions - New Zealand  

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

Oceania New Zealand Graphics CO2 Emissions from New Zealand Data graphic Data CO2 Emissions from New Zealand image Per capita CO2 Emission Estimates for New Zealand...

353

CO2 Emissions - Hong Kong  

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

Far East Hong Kong CO2 Emissions from Hong Kong Data graphic Data CO2 Emissions from Hong Kong image Per capita CO2 Emission Estimates for Hong Kong...

354

CO2 Emissions - Wake Island  

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

Fossil Fuel CO2 Emissions Regional Oceania Wake Island Graphics CO2 Emissions from Wake Island Data graphic Data CO2 Emissions from Wake Island image Per capita CO2...

355

NETL: Turbine Projects - Emissions Reduction  

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

Emissions Reduction Turbine Projects Emissions Reduction Pre-Mixer Design for High Hydrogen Fuels DataFact Sheets Low-NOX Emissions in a Fuel Flexible Gas Turbine Combustor Design...

356

Global Fossil Fuel Carbon Emissions - Graphics  

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

Fossil-Fuel CO2 Emissions Global Graphics Global Fossil-Fuel Carbon Emissions - Graphics Carbon Emission Estimates image image Global Per Capita Carbon Emission Estimates...

357

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

Science Conference Proceedings (OSTI)

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

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

2012-08-15T23:59:59.000Z

358

Formation and Evolution of Planetary Systems (FEPS): Primordial Warm Dust Evolution From 3-30 Myr around Sun-like Stars  

E-Print Network (OSTI)

We present data obtained with the Infrared Array Camera (IRAC) aboard the Spitzer Space Telescope (Spitzer) for a sample of 74 young (t science program entitled the Formation and Evolution of Planetary Systems (FEPS). Using IRAC we study the fraction of young stars that exhibit 3.6-8.0 micron infrared emission in excess of that expected from the stellar photosphere, as a function of age from 3-30 Myr. The most straightforward interpretation of such excess emission is the presence of hot (300-1000K) dust in the inner regions (results with accretion disk fractions detected in previous studies, and use the ensemble results to place additional constraints on the dissipation timescales for optically-thick, primordial disks.

M. D. Silverstone; M. R. Meyer; E. E. Mamajek; D. C. Hines; L. A. Hillenbrand; J. Najita; I. Pascucci; J. Bouwman; J. S. Kim; J. M. Carpenter; J. R. Stauffer; D. E. Backman; A. Moro-Martin; T. Henning; S. Wolf; T. Y. Brooke; D. L. Padgett

2005-11-09T23:59:59.000Z

359

Emission Standards for Contaminants (Iowa)  

Energy.gov (U.S. Department of Energy (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...

360

CO2 Emissions - Netherland Antilles  

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

Central America, South America, and the Caribbean Nations Netherland Antilles Graphics CO2 Emissions from Netherland Antilles Data graphic Data CO2 Emissions from Netherland...

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

CO2 Emissions - Ryukyu Islands  

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

Oceania Ryukyu Islands Graphics CO2 Emissions from the Ryukyu Islands Data graphic Data CO2 Emissions from the Ryukyu Islands image...

362

CO2 Emissions - Leeward Islands  

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

Central America, South America, and the Caribbean Nations Leeward Islands Graphics CO2 Emissions from Leeward Islands Data graphic Data CO2 Emissions from Leeward Islands image...

363

carbon emissions | OpenEI  

Open Energy Info (EERE)

2010 (4 years ago) Date Updated Unknown Keywords capacity carbon emissions energy demand Energy Generation fossil fuels GHG emissions UK Data applicationvnd.openxmlformats-office...

364

NETL: Advanced NOx Emissions Control  

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

Home > Technologies > Coal & Power Systems > Innovations for Existing Plants > Advanced NOx Emissions Control Innovations for Existing Plants Advanced NOx Emissions Control Adv....

365

Engines - Emissions Assessment  

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

EPRI Hybrid Electric Vehicle Working Group: HEV Costs and Emissions EPRI Hybrid Electric Vehicle Working Group: HEV Costs and Emissions Hybrid electric vehicles (HEVs) are attractive options for increasing vehicle fuel economy and reducing emissions of criteria pollutants and greenhouse gases. Two automobile manufacturers have already introduced HEVs, and other manufacturers are planning to introduce their own models. One available HEV combines mass reduction (also applicable to conventional vehicles) with idle-stop, regenerative braking, and electric-drive assist to achieve a fuel economy more than 2.5 times the current Corporate Average Fuel Economy (CAFE) standard. The second HEV combines idle-stop, regenerative braking, electric assist acceleration, and continuously variable transmission (CVT) to achieve a fuel economy of more than twice the current CAFÉ standard, qualifying as a super ultra-low emissions vehicle (SULEV).

366

Pulsar Emission Spectrum  

E-Print Network (OSTI)

Emission spectrum is calculated for a weak axisymmetric pulsar. Also calculated are the observed spectrum, efficiency, and the observed efficiency. The underlying flow of electrons and positrons turns out to be curiously intricate.

Gruzinov, Andrei

2013-01-01T23:59:59.000Z

367

China Energy and Emissions  

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

China Energy and Emissions Paths to 2030 (2 nd Edition) David Fridley, Nina Zheng, Nan Zhou, Jing Ke, Ali Hasanbeigi, Bill Morrow, and Lynn Price China Energy Group, Energy...

368

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

369

Nitrous oxide emissions  

SciTech Connect

The purpose of this paper is to report the effect of key operating parameters, the relative importance of coal type, and the potentially significant coal properties for producing N{sub 2}O emissions in an atmospheric circulating fluidized-bed combustor (CFBC) and pressurized bubbling fluidized-bed combustor (PFBC). The generation of N{sub 2}O emissions is quantified in an empirical model based on the experimental data.

Mann, M.D.; Collings, M.E.; Young, B.C.

1992-12-01T23:59:59.000Z

370

Nitrous oxide emissions  

SciTech Connect

The purpose of this paper is to report the effect of key operating parameters, the relative importance of coal type, and the potentially significant coal properties for producing N[sub 2]O emissions in an atmospheric circulating fluidized-bed combustor (CFBC) and pressurized bubbling fluidized-bed combustor (PFBC). The generation of N[sub 2]O emissions is quantified in an empirical model based on the experimental data.

Mann, M.D.; Collings, M.E.; Young, B.C.

1992-01-01T23:59:59.000Z

371

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

372

Volumetric measurements of a spatially growing dust acoustic wave  

Science Conference Proceedings (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

373

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

374

Particle creation in (2+1) circular dust collapse  

E-Print Network (OSTI)

We investigate the quantum particle creation during the circularly symmetric collapse of a 2+1 dust cloud, for the cases when the cosmological constant is either zero or negative. We derive the Ford-Parker formula for the 2+1 case, which can be used to compute the radiated quantum flux in the geometric optics approximation. It is shown that no particles are created when the collapse ends in a naked singularity, unlike in the 3+1 case. When the collapse ends in a BTZ black hole, we recover the expected Hawking radiation. 1

Sashideep Gutti; T. P. Singh

2007-01-01T23:59:59.000Z

375

Gas Turbine Emissions  

E-Print Network (OSTI)

Historically, preliminary design information regarding gas turbine emissions has been unreliable, particularly for facilities using steam injection and other forms of Best Available Control Technology (BACT). This was probably attributed to the lack of regulatory interest in the 'real world' test results coupled with the difficulties of gathering analogous bench test data for systems employing gas turbines with Heat Recovery Steam Generators (HRSG) and steam injection. It appears that the agencies are getting a better grasp of emissions, but there are still problem areas, particularly CO and unburned hydrocarbon emissions. The lag in data has resulted in the imposition of a CO reactor as BACT for the gas turbine. With the renewed concern about the environment, air permits will have a high profile with offsets being the next fix beyond BACT. 'The manner in which technology developers and electric utilities will share emissions reductions in the coming era of pollution allowance trading is becoming prominent on the agendas of strategic planners at technology vendors and the electric power industry....' (1) Therefore, it becomes increasingly important that the proponents of gas turbine-based facilities establish more reliable data on their proposed emissions. This paper addresses the gas turbine emissions experiences of eight cogeneration plants utilizing: 1) steam injection for both NOx control and power augmentation, 2) CO reactors, 3) selective catalytic reduction units. It also looks at possible regulatory actions.

Frederick, J. D.

1990-06-01T23:59:59.000Z

376

The origin of the infrared emission in radio galaxies II: analysis of mid- to far-infrared Spitzer observations of the 2Jy sample  

E-Print Network (OSTI)

We present an analysis of deep mid- to far-infrared (MFIR) Spitzer photometric observations of the southern 2Jy sample of powerful radio sources (0.05 links between radio jet, AGN, starburst activity and MFIR properties. This is part of an ongoing extensive study of powerful radio galaxies that benefits from both complete optical emission line information and a uniquely high detection rate in the far-infrared (far-IR). We find tight correlations between the MFIR and [OIII] emission luminosities, which are significantly better than those between MFIR and extended radio luminosities, or between radio and [OIII] luminosities. Since [OIII] is a known indicator of intrinsic AGN power, these correlations confirm AGN illumination of the circum-nuclear dust as the primary heating mechanism for the dust producing thermal MFIR emission at both 24 and 70 microns. We demonstrate that AGN heating is energetically feasible, and identify the narrow line region ...

Dicken, D; Axon, D; Morganti, R; Inskip, K J; Holt, J; Delgado, R Gonzalez; Groves, B

2008-01-01T23:59:59.000Z

377

Paraho environmental data. Part I. Process characterization  

DOE Green Energy (OSTI)

Most of the process characterization environmental data were obtained during 1977-1978 when both Paraho retorts were operated in the Direct Heat Mode to produce 100,000 barrels of crude shale oil for testing by the US Navy. The data compiled in this volume is arranged into the four categories, solids, liquids, gases and quality assurance. Included in the raw shale category are the following: raw shale feed, crushed and screened for feedstock to the Paraho retorts; raw shale fines, the - 1/2'' (minus one-half inch) material rejected from the crushing and polishing screen operations; raw shale dust, collected from the raw shale dust baghouse. Any fugitive dust emission data are not compiled in this volume. Included in the retorted shale category are the material conveyed to the disposal area and the retorted shale dust collected from the retorted shale dust baghouse. Liquids include crude shale oil and process water. Crude shale oil samples include wet oil from the run-down tanks and the dry oil from the oil-water separation tanks. Since the water is removed in the laboratory before performing chemical analyses, the data from the two oil samples are presented together. Process water includes the following: product water drained from the crude shale oil; process water, condensed and drained from the recycle gas blower and lines; evaporation pond, a collection of waters from the industrial sewer system, leachate from the retorted shale, and surface runoff from the retorting, shale disposal and oil storage areas. Included in the gases are the recycle, or product, gas and the stack gas from the thermal oxidizer. Not compiled in this volume are the fugitive gas emission data.

Heistand, R.N.; Richardson, K.L.

1980-04-01T23:59:59.000Z

378

Impact of Desert Dust Radiative Forcing on Sahel Precipitation: Relative Importance of Dust Compared to Sea Surface Temperature Variations, Vegetation Changes, and Greenhouse Gas Warming  

Science Conference Proceedings (OSTI)

The role of direct radiative forcing of desert dust aerosol in the change from wet to dry climate observed in the African Sahel region in the last half of the twentieth century is investigated using simulations with an atmospheric general ...

Masaru Yoshioka; Natalie M. Mahowald; Andrew J. Conley; William D. Collins; David W. Fillmore; Charles S. Zender; Dani B. Coleman

2007-04-01T23:59:59.000Z

379

Roles of saltation, sandblasting, and wind speed variability on mineral dust aerosol size distribution during the Puerto Rican Dust Experiment (PRIDE)  

E-Print Network (OSTI)

Plumes arriving at Puerto Rico during the night would not beD > 5 µm) modeled at Puerto Rico. Assuming that the coarsetechniques during the Puerto Rico Dust Experiment (PRIDE)

Grini, A; Zender, C S

2004-01-01T23:59:59.000Z

380

Dust Grain-Size Distributions From MRN to MEM  

E-Print Network (OSTI)

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

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

2003-01-24T23:59:59.000Z

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

Growth of Dust as the Initial Step Toward Planet Formation  

E-Print Network (OSTI)

We discuss the results of laboratory measurements and theoretical models concerning the aggregation of dust in protoplanetary disks, as the initial step toward planet formation. Small particles easily stick when they collide and form aggregates with an open, often fractal structure, depending on the growth process. Larger particles are still expected to grow at collision velocities of about 1m/s. Experiments also show that, after an intermezzo of destructive velocities, high collision velocities above 10m/s on porous materials again lead to net growth of the target. Considerations of dust-gas interactions show that collision velocities for particles not too different in surface-to-mass ratio remain limited up to sizes about 1m, and growth seems to be guaranteed to reach these sizes quickly and easily. For meter sizes, coupling to nebula turbulence makes destructive processes more likely. Global aggregation models show that in a turbulent nebula, small particles are swept up too fast to be consistent with observations of disks. An extended phase may therefore exist in the nebula during which the small particle component is kept alive through collisions driven by turbulence which frustrates growth to planetesimals until conditions are more favorable for one or more reasons.

C. Dominik; J. Blum; J. Cuzzi; G. Wurm

2006-02-28T23:59:59.000Z

382

Three-dimensional reconstruction of dust particle trajectories in the NSTXa... W. U. Boeglin,1  

E-Print Network (OSTI)

. Roquemore,2 and R. Maqueda3 1 Physics Department, Florida International University, 11200 SW 8th Street to be controlled for safety reasons.1 Research into dust behavior in fusion devices includes the formation of dust ac- curately the difference of the particle's brightness and the surrounding background light should

Princeton Plasma Physics Laboratory

383

Understanding the Transport and Impact of African Dust on the Caribbean Basin  

Science Conference Proceedings (OSTI)

Every year huge quantities of soil dust are carried by winds from Africa, across the Atlantic, and to the Caribbean. No other ocean region is so extensively and persistently impacted by such high concentrations of dust, a region that extends over 7000 km ...

Joseph M. Prospero; Olga L. Mayol-Bracero

2013-09-01T23:59:59.000Z

384

The March 2009 Dust Event in Saudi Arabia: Precursor and Supportive Environment  

Science Conference Proceedings (OSTI)

A case study is presented of the environmental background for a massive Saudi Arabian dust storm event that took place on 10 and 11 March 2009. The dust storm was large enough to be clearly seen from outer space and caused a widespread heavy atmospheric ...

B. H. Alharbi; A. Maghrabi; N. Tapper

2013-04-01T23:59:59.000Z

385

Anomalous kinetic energy of a system of dust particles in a gas discharge plasma  

SciTech Connect

The system of equations of motion of dust particles in a near-electrode layer of a gas discharge has been formulated taking into account fluctuations of the charge of a dust particle and the features of the nearelectrode layer of the discharge. The molecular dynamics simulation of the system of dust particles has been carried out. Performing a theoretical analysis of the simulation results, a mechanism of increasing the average kinetic energy of dust particles in the gas discharge plasma has been proposed. According to this mechanism, the heating of the vertical oscillations of dust particles is initiated by induced oscillations generated by fluctuations of the charge of dust particles, and the energy transfer from vertical to horizontal oscillations can be based on the parametric resonance phenomenon. The combination of the parametric and induced resonances makes it possible to explain an anomalously high kinetic energy of dust particles. The estimate of the frequency, amplitude, and kinetic energy of dust particles are close to the respective experimental values.

Norman, G. E., E-mail: norman@ihed.ras.ru; Stegailov, V. V., E-mail: stegailov@gmail.com; Timofeev, A. V., E-mail: timofeevalvl@gmail.com [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

2011-11-15T23:59:59.000Z

386

Study on plasma parameters and dust charging in an electrostatically plugged multicusp plasma device  

Science Conference Proceedings (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

387

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

388

Modeled Downward Transport of a Passive Tracer over Western North America during an Asian Dust Event in April 1998  

Science Conference Proceedings (OSTI)

An intense Gobi Desert dust storm in April 1998 loaded the midtroposphere with dust that was transported across the Pacific to western North America. The Mesoscale Compressible Community (MC2) model was used to investigate mechanisms causing ...

Joshua P. Hacker; Ian G. McKendry; Roland B. Stull

2001-09-01T23:59:59.000Z

389

Two Case Studies of the Transport of Dust Storm Aerosol and the Potential for Incorporation into Precipitation  

Science Conference Proceedings (OSTI)

To investigate the hypothesis that dust storms enhanced the calcium concentrations in precipitation in the mid-1950s, two case studies were performed for major dust events in the southern Plains of the United States during March and April of ...

Kevin G. Doty; Richard G. Semonin

1987-07-01T23:59:59.000Z

390

Examining the Effects of Dust Aerosols on Satellite Sea Surface Temperatures in the Mediterranean Sea Using the Medspiration Matchup Database  

Science Conference Proceedings (OSTI)

Dust aerosol plumes from the Sahara cover the Mediterranean Sea regularly during the summer months (June–August) and occasionally during other seasons. Dust can absorb infrared longwave radiation, thus causing a drop in sea surface temperature (...

Ana B. Ruescas; Manuel Arbelo; Jose A. Sobrino; Cristian Mattar

2011-05-01T23:59:59.000Z

391

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

392

Radiative impact of mineral dust on monsoon precipitation variability over West Africa  

SciTech Connect

The radiative forcing of dust and its impact on precipitation over the West Africa monsoon (WAM) region is simulated using a coupled meteorology and aerosol/chemistry model (WRF-Chem). During the monsoon season, dust is a dominant contributor to AOD over West Africa. In the standard simulation, on 24-hour domain average, dust has a cooling effect (-6.11 W/m2) at the surface, a warming effect (6.94 W/m2) in the atmosphere, and a relatively small TOA forcing (0.83 W/m2). Dust modifies the surface energy budget and atmospheric diabatic heating and hence causes lower atmospheric cooling in the daytime but warming in the nighttime. As a result, atmospheric stability is increased in the daytime and reduced in the nighttime, leading to a reduction of late afternoon precipitation by up to 0.14 mm/hour (30%) and an increase of nocturnal and early morning precipitation by up to 0.04 mm/hour (23%) over the WAM region. Dust-induced reduction of diurnal precipitation variation improves the simulated diurnal cycle of precipitation when compared to measurements. However, daily precipitation is only changed by a relatively small amount (-0.14 mm/day or -4%). On the other hand, sensitivity simulations show that, for weaker-to-stronger absorbing dust, dust longwave warming effect in the nighttime surpasses its shortwave cooling effect in the daytime at the surface, leading to a less stable atmosphere associated with more convective precipitation in the nighttime. As a result, the dust-induced change of daily WAM precipitation varies from a significant reduction of -0.40 mm/day (-12%, weaker absorbing dust) to a small increase of 0.05 mm/day (1%, stronger absorbing dust). This variation originates from the competition between dust impact on daytime and nighttime precipitation, which depends on dust shortwave absorption. Dust reduces the diurnal variation of precipitation regardless of its absorptivity, but more reduction is associated with stronger absorbing dust.

Zhao, Chun; Liu, Xiaohong; Leung, Lai-Yung R.; Hagos, Samson M.

2011-03-01T23:59:59.000Z

393

GHG emissions | OpenEI  

Open Energy Info (EERE)

GHG emissions GHG emissions Dataset Summary Description These datasets include GHG and CO2 emissions statistics for the European Union (EU). The statistics are available from the European Commission. Source European Commission Date Released Unknown Date Updated Unknown Keywords Biofuels CO2 emissions EU GHG emissions Data application/vnd.ms-excel icon Total GHG and CO2 Emissions for EU (xls, 853.5 KiB) application/vnd.ms-excel icon GHG Emissions by Sector, all member countries (xls, 2 MiB) application/vnd.ms-excel icon GHG Emissions from Transport, all member countries (xls, 1.3 MiB) application/vnd.ms-excel icon CO2 emissions by sector, all member countries (xls, 2.1 MiB) application/vnd.ms-excel icon CO2 emissions by transport, all member countries (xls, 1.5 MiB)

394

EIA - Greenhouse Gas Emissions Overview  

Gasoline and Diesel Fuel Update (EIA)

Environment Environment Emissions of Greenhouse Gases in the U. S. Release Date: March 31, 2011 | Next Release Date: Report Discontinued | Report Number: DOE/EIA-0573(2009) Greenhouse Gas Emissions Overview Diagram Notes [a] CO2 emissions related to petroleum consumption (includes 64 MMTCO2 of non-fuel-related emissions). [b] CO2 emissions related to coal consumption (includes 0.3 MMTCO2 of non-fuel-related emissions). [c] CO2 emissions related to natural gas consumption (includes 13 MMTCO2 of non-fuel-related emissions). [d] Excludes carbon sequestered in nonfuel fossil products. [e] CO2 emissions from the plastics portion of municipal solid waste (11 MMTCO2) combusted for electricity generation and very small amounts (0.4 MMTCO2) of geothermal-related emissions.

395

Geek-Up[6.24.11]: Dust-sized 'Dragonfly' Device and Tiny Microvalves |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Dust-sized 'Dragonfly' Device and Tiny Dust-sized 'Dragonfly' Device and Tiny Microvalves Geek-Up[6.24.11]: Dust-sized 'Dragonfly' Device and Tiny Microvalves June 24, 2011 - 7:15pm Addthis A computer simulation of the "dragonfly-inspired" device. | Courtesy of Sandia Laboratory A computer simulation of the "dragonfly-inspired" device. | Courtesy of Sandia Laboratory Niketa Kumar Niketa Kumar Public Affairs Specialist, Office of Public Affairs What are the key facts? A dust-size "dragonfly-inspired" device -- which won a Sandia Lab design contest -- may ultimately enable the creation of tiny microvalves for experiments in biological research laboratories and medical facilities. In Sandia National Laboratories' MEMS (microelectromechanical system) University Alliance design contest, a dust-sized dragonfly and a super

396

Roles of polarization force and nonthermal electron on dust-acoustic waves in an inhomogeneous dusty plasma with positively charged dust  

Science Conference Proceedings (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

397

THE PHYSICS OF PROTOPLANETESIMAL DUST AGGLOMERATES. VII. THE LOW-VELOCITY COLLISION BEHAVIOR OF LARGE DUST AGGLOMERATES  

Science Conference Proceedings (OSTI)

We performed micro-gravity collision experiments in our laboratory drop tower using 5 cm sized dust agglomerates with volume filling factors of 0.3 and 0.4, respectively. This work is an extension of our previous experiments reported in Beitz et al. to aggregates of more than one order of magnitude higher masses. The dust aggregates consisted of micrometer-sized silica particles and were macroscopically homogeneous. We measured the coefficient of restitution for collision velocities ranging from 1 cm s{sup -1} to 0.5 m s{sup -1}, and determined the fragmentation velocity. For low velocities, the coefficient of restitution decreases with increasing impact velocity, in contrast to findings by Beitz et al. At higher velocities, the value of the coefficient of restitution becomes constant, before the aggregates break at the onset of fragmentation. We interpret the qualitative change in the coefficient of restitution as the transition from a solid-body-dominated to a granular-medium-dominated behavior. We complement our experiments by molecular-dynamics simulations of porous aggregates and obtain a reasonable match to the experimental data. We discuss the importance of our experiments for protoplanetary disks, debris disks, and planetary rings. This work is an extension to the previous work of our group and gives new insight into the velocity dependency of the coefficient of restitution due to improved measurements, better statistics, and a theoretical approach.

Schraepler, Rainer; Blum, Juergen [Institut fuer Geophysik und extraterrestrische Physik, University of Braunschweig Mendelssohnstr. 3, D-38106 Braunschweig (Germany); Seizinger, Alexander; Kley, Wilhelm, E-mail: r.schraepler@tu-bs.de [Institut fuer Astronomie und Astrophysik, University of Tuebingen Auf der Morgenstelle 10, D-72076 Tuebingen (Germany)

2012-10-10T23:59:59.000Z

398

Gas turbine plant emissions  

SciTech Connect

Many cogeneration facilities use gas turbines combined with heat recovery boilers, and the number is increasing. At the start of 1986, over 75% of filings for new cogeneration plants included plans to burn natural gas. Depending on the geographic region, gas turbines are still one of the most popular prime movers. Emissions of pollutants from these turbines pose potential risks to the environment, particularly in geographical areas that already have high concentrations of cogeneration facilities. Although environmental regulations have concentrated on nitrogen oxides (NO/sub x/) in the past, it is now necessary to evaluate emission controls for other pollutants as well.

Davidson, L.N.; Gullett, D.E.

1987-03-01T23:59:59.000Z

399

Superfund Record of Decision (EPA Region 8): Anaconda Smelter Site, Mill Creek, Montana (first remedial action), October 1988  

Science Conference Proceedings (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

400

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

Note: This page contains sample records for the topic "fugitive dust emissions" from the National Library of EnergyBeta (NLEBeta).
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to obtain the most current and comprehensive results.


401

DUST SPECTRAL ENERGY DISTRIBUTIONS IN THE ERA OF HERSCHEL AND PLANCK: A HIERARCHICAL BAYESIAN-FITTING TECHNIQUE  

SciTech Connect

We present a hierarchical Bayesian method for fitting infrared spectral energy distributions (SEDs) of dust emission to observed fluxes. Under the standard assumption of optically thin single temperature (T) sources, the dust SED as represented by a power-law-modified blackbody is subject to a strong degeneracy between T and the spectral index {beta}. The traditional non-hierarchical approaches, typically based on {chi}{sup 2} minimization, are severely limited by this degeneracy, as it produces an artificial anti-correlation between T and {beta} even with modest levels of observational noise. The hierarchical Bayesian method rigorously and self-consistently treats measurement uncertainties, including calibration and noise, resulting in more precise SED fits. As a result, the Bayesian fits do not produce any spurious anti-correlations between the SED parameters due to measurement uncertainty. We demonstrate that the Bayesian method is substantially more accurate than the {chi}{sup 2} fit in recovering the SED parameters, as well as the correlations between them. As an illustration, we apply our method to Herschel and submillimeter ground-based observations of the star-forming Bok globule CB244. This source is a small, nearby molecular cloud containing a single low-mass protostar and a starless core. We find that T and {beta} are weakly positively correlated-in contradiction with the {chi}{sup 2} fits, which indicate a T-{beta} anti-correlation from the same data set. Additionally, in comparison to the {chi}{sup 2} fits the Bayesian SED parameter estimates exhibit a reduced range in values.

Kelly, Brandon C.; Goodman, Alyssa A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Shetty, Rahul [Zentrum fuer Astronomie der Universitaet Heidelberg, Institut fuer Theoretische Astrophysik, Albert-Ueberle-Str. 2, 69120 Heidelberg (Germany); Stutz, Amelia M.; Launhardt, Ralf [Max Planck Institut fuer Astronomie, Koenigstuhl 17, 69117 Heidelberg (Germany); Kauffmann, Jens [NASA JPL, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States)

2012-06-10T23:59:59.000Z

402

EIA - Greenhouse Gas Emissions Overview  

Gasoline and Diesel Fuel Update (EIA)

Greenhouse Gas Tables (1990-2009) Greenhouse Gas Tables (1990-2009) Table Title Formats Overview 1 U.S. emissions of greenhouse gases, based on global warming potential 2 U.S. greenhouse gas intensity and related factors 3 Distribution of total U.S. greenhouse gas emissions by end-use sector 4 World energy-related carbon dioxide emissions by region 5 Greenhouse gases and 100-year net global warming potentials Carbon dioxide emissions 6 U.S. carbon dioxide emissions from energy and industry 7 U.S. energy-related carbon dioxide emissions by end-use sector 8 U.S. carbon dioxide emission from residential sector energy consumption 9 U.S. carbon dioxide emissions from commercial sector energy consumption 10 U.S. carbon dioxide emissions from industrial sector energy consumption

403

Hamiltonian spacetime dynamics with a spherical null-dust shell  

E-Print Network (OSTI)

We consider the Hamiltonian dynamics of spherically symmetric Einstein gravity with a thin null-dust shell, under boundary conditions that fix the evolution of the spatial hypersurfaces at the two asymptotically flat infinities of a Kruskal-like manifold. The constraints are eliminated via a Kuchar-type canonical transformation and Hamiltonian reduction. The reduced phase space $\\tilde\\Gamma$ consists of two disconnected copies of $R^4$, each associated with one direction of the shell motion. The right-moving and left-moving test shell limits can be attached to the respective components of right-hand-side and left-hand-side masses as configuration variables provides a global canonical chart on each component of $\\tilde\\Gamma$, and renders the Hamiltonian simple, but encodes the shell dynamics in the momenta in a convoluted way. Choosing the shell curvature radius and the "interior" mass as configuration variables renders the shell dynamics transparent in an arbitrarily specifiable stationary gauge "exterior" ...

Louko, J; Friedman, J L; Louko, Jorma; Whiting, Bernard F.; Friedman, John L.

1998-01-01T23:59:59.000Z

404

Harrison transformation of hyperelliptic solutions and charged dust disks  

E-Print Network (OSTI)

We use a Harrison transformation on solutions to the stationary axisymmetric Einstein equations to generate solutions of the Einstein-Maxwell equations. The case of hyperelliptic solutions to the Ernst equation is studied in detail. Analytic expressions for the metric and the multipole moments are obtained. As an example we consider the transformation of a family of counter-rotating dust disks. The resulting solutions can be interpreted as disks with currents and matter with a purely azimuthal pressure or as two streams of freely moving charged particles. We discuss interesting limiting cases as the extreme limit where the charge becomes identical to the mass, and the ultrarelativistic limit where the central redshift diverges.

C. Klein

2005-12-22T23:59:59.000Z

405

PHOTOELECTRIC CROSS-SECTIONS OF GAS AND DUST IN PROTOPLANETARY DISKS  

SciTech Connect

We provide simple polynomial fits to the X-ray photoelectric cross-sections (0.03 keV < E < 10 keV) for mixtures of gas and dust found in protoplanetary disks. Using the solar elemental abundances of Asplund et al., we treat the gas and dust components separately, facilitating the further exploration of evolutionary processes such as grain settling and gain growth. We find that blanketing due to advanced grain growth (a{sub max} > 1 {mu}m) can reduce the X-ray opacity of dust appreciably at E{sub X} {approx} 1 keV, coincident with the peak of typical T Tauri X-ray spectra. However, the reduction of dust opacity by dust settling, which is known to occur in protoplanetary disks, is probably a more significant effect. The absorption of 1-10 keV X-rays is dominated by gas opacity once the dust abundance has been reduced to about 1% of its diffuse interstellar value. The gas disk establishes a floor to the opacity at which point X-ray transport becomes insensitive to further dust evolution. Our choice of fitting function follows that of Morrison and McCammon, providing a degree of backward compatibility.

Bethell, T. J.; Bergin, Edwin A., E-mail: tbethell@umich.edu [Astronomy Department, University of Michigan, Ann Arbor, MI 48109 (United States)

2011-10-10T23:59:59.000Z

406

Dust-to-gas ratio and star formation history of blue compact dwarf galaxies  

E-Print Network (OSTI)

This paper investigates the origin of the observed large variety in dust-to-gas ratio among blue compact dwarf galaxies (BCDs). By applying our chemical evolution model, we find that the dust destruction can largely suppress the dust-to-gas ratio when the metallicity of a BCD reaches $12+\\log{\\rm (O/H)}\\sim 8$, i.e., a typical metallicity level of BCDs. We also show that dust-to-gas ratio is largely varied owing to the change of dust destruction efficiency that has two effects: (i) a significant contribution of Type Ia supernovae to total supernova rate; (ii) variation of gas mass contained in a star-forming region. While mass loss from BCDs was previously thought to be the major cause for the variance of dust-to-gas ratio, we suggest that the other two effects are also important. We finally discuss the intermittent star formation history, which naturally explains the large dispersion of dust-to-gas ratio among BCDs.

H. Hirashita; Y. Y. Tajiri; H. Kamaya

2002-04-18T23:59:59.000Z

407

Dispersion relation for pure dust Bernstein waves in a non-Maxwellian magnetized dusty plasma  

SciTech Connect

Pure dust Bernstein waves are investigated using non-Maxwellian kappa and (r,q) distribution functions in a collisionless, uniform magnetized dusty plasma. Dispersion relations for both the distributions are derived by considering waves whose frequency is of the order of dust cyclotron frequency, and dispersion curves are plotted. It is observed that the propagation band for dust Bernstein waves is rather narrow as compared with that of the electron Bernstein waves. However, the band width increases for higher harmonics, for both kappa and (r,q) distributions. Effect of dust charge on dispersion curves is also studied, and one observes that with increasing dust charge, the dispersion curves shift toward the lower frequencies. Increasing the dust to ion density ratio ((n{sub d0}/n{sub i0})) causes the dispersion curve to shift toward the higher frequencies. It is also found that for large values of spectral index kappa ({kappa}), the dispersion curves approach to the Maxwellian curves. The (r,q) distribution approaches the kappa distribution for r = 0, whereas for r > 0, the dispersion curves show deviation from the Maxwellian curves as expected. Relevance of this work can be found in astrophysical plasmas, where non-Maxwellian velocity distributions as well as dust particles are commonly observed.

Deeba, F. [National Tokamak Fusion Program, PAEC, P.O. Box 3329, Islamabad 44000 (Pakistan); Department of Physics, G.C. University, Lahore 54000 (Pakistan); Ahmad, Zahoor [National Tokamak Fusion Program, PAEC, P.O. Box 3329, Islamabad 44000 (Pakistan); Murtaza, G. [Salam Chair in Physics, G.C. University, Lahore 54000 (Pakistan)

2011-07-15T23:59:59.000Z

408

Coal dust contiguity-induced changes in the concentration of TNF- and NF- B p65 on the ocular surface  

Science Conference Proceedings (OSTI)

To observe the influence of coal dust on ocular surface of coal miners and rabbits with coal dust contiguity on expression TNF- and NF- Bp65 and dry eye occurrence. Expression TNF- and NF- Bp65 in ocular surface were determined. Results showed tear production, BUT and lysozyme decreased for coal miners and rabbits with coal dust contiguity. Coal dust exposure was linked to development of xerophthalmia, and induced a higher expression of NF- B p65 and TNF- perhaps as a mechanism to resist coal dust ocular surface injury.

Sun, Z.Y.; Hong, J.; Liu, Z.Y.; Jin, X.D.; Gu, C.H. [China Medical University, Shenyang (China)

2009-07-01T23:59:59.000Z

409

Apparatus for dusting off gas by filtration and aspiration cleaning of filter, and application to combustion gases  

SciTech Connect

Method and apparatus for dusting off gases by filtration and cleaning of filter by aspiration and application thereof to combustion gases are disclosed. This invention relates to the filtration of dust loaded gases, and, in particular, combustion gases in the hot state. It consists of passing gases to be dusted off from top to bottom over a bed of pulverulent material, in particular, a sand bed and cleaning the upper layer of said bed by aspiration of dusts deposited thereon. This invention is particularly adapted for dusting off combustion gases from boilers or thermal power stations or gases to be supplied to gas turbines.

Merry, J.

1982-07-06T23:59:59.000Z

410

The origin of the infrared emission in radio galaxies II: analysis of mid- to far-infrared Spitzer observations of the 2Jy sample  

E-Print Network (OSTI)

We present an analysis of deep mid- to far-infrared (MFIR) Spitzer photometric observations of the southern 2Jy sample of powerful radio sources (0.05 links between radio jet, AGN, starburst activity and MFIR properties. This is part of an ongoing extensive study of powerful radio galaxies that benefits from both complete optical emission line information and a uniquely high detection rate in the far-infrared (far-IR). We find tight correlations between the MFIR and [OIII] emission luminosities, which are significantly better than those between MFIR and extended radio luminosities, or between radio and [OIII] luminosities. Since [OIII] is a known indicator of intrinsic AGN power, these correlations confirm AGN illumination of the circum-nuclear dust as the primary heating mechanism for the dust producing thermal MFIR emission at both 24 and 70 microns. We demonstrate that AGN heating is energetically feasible, and identify the narrow line region clouds as the most likely location of the cool, far-IR emitting dust. Starbursts make a major contribution to the heating of the cool dust in only 15-28% of our targets. We also investigate the orientation dependence of the continuum properties, finding that the broad- and narrow-line objects in our sample with strong emission lines have similar distributions of MFIR luminosities and colours. Therefore our results are entirely consistent with the orientation-based unified schemes for powerful radio galaxies. However, the weak line radio galaxies (WLRG) form a separate class of objects with intrinsically low luminosity AGN in which both the optical emission lines and the MFIR continuum are weak.

D. Dicken; C. Tadhunter; D. Axon; R. Morganti; K. J. Inskip; J. Holt; R. Gonzalez Delgado; B. Groves

2008-10-31T23:59:59.000Z

411

EFFECT OF DUST ON Ly{alpha} PHOTON TRANSFER IN AN OPTICALLY THICK HALO  

SciTech Connect

We investigate the effects of dust on Ly{alpha} photons emergent from an optically thick medium by solving the integro-differential equation of radiative transfer of resonant photons. To solve the differential equations numerically, we use the weighted essentially non-oscillatory method. Although the effects of dust on radiative transfer are well known, the resonant scattering of Ly{alpha} photons makes the problem non-trivial. For instance, if the medium has an optical depth of dust absorption and scattering of {tau}{sub a} >> 1, {tau} >> 1, and {tau} >> {tau}{sub a}, the effective absorption optical depth in a random walk scenario would be equal to {radical}({tau}{sub a}({tau}{sub a}+{tau})). We show, however, that for a resonant scattering at frequency {nu}{sub 0}, the effective absorption optical depth would be even larger than {tau}({nu}{sub 0}). If the cross section of dust scattering and absorption is frequency-independent, the double-peaked structure of the frequency profile given by the resonant scattering is basically dust-independent. That is, dust causes neither narrowing nor widening of the width of the double-peaked profile. One more result is that the timescales of the Ly{alpha} photon transfer in an optically thick halo are also basically independent of the dust scattering, even when the scattering is anisotropic. This is because those timescales are mainly determined by the transfer in the frequency space, while dust scattering, either isotropic or anisotropic, does not affect the behavior of the transfer in the frequency space when the cross section of scattering is wavelength-independent. This result does not support the speculation that dust will lead to the smoothing of the brightness distribution of a Ly{alpha} photon source with an optically thick halo.

Yang Yang; Shu Chiwang [Division of Applied Mathematics, Brown University, Providence, RI 02912 (United States); Roy, Ishani [Computing Laboratory, University of Oxford, Oxford, OX1 3QD (United Kingdom); Fang Lizhi [Department of Physics, University of Arizona, Tucson, AZ 85721 (United States)

2011-10-01T23:59:59.000Z

412

Extraplanar Dust in the Edge-On Spiral NGC 891 1  

E-Print Network (OSTI)

We present high-resolution (0.6 ? ?-0.65 ? ? ) optical broad-band images of the edge-on Sb galaxy NGC 891 obtained with the WIYN 3.5-m telescope. These BVR images reveal a complex network of hundreds of dust absorbing structures far from the mid-plane of the galaxy. The dust structures have a wide range of morphologies and are clearly visible to |z | ? 1021 cm ?2, with masses estimated to be more than 2 × 10 5 ? 5 × 10 6 M?, assuming Galactic gas-to-dust relationships. The gravitational potential energies of the individual dust structures, given their observed heights and derived masses, lie in the range of 20 ? 200 × 10 51 ergs, which represents the energy input of at least tens to hundreds of supernovae. Rough number counts of extraplanar dust features find ?>120 structures at |z |> 400 pc with apparent B-band extinction ?> 0.25 mag. If these have similar properties to those structures studied in detail, the mass of high-z gas associated with extraplanar dust in NGC 891 likely exceeds 2 × 10 8 M?, which is ?2 % of the total neutral ISM mass of the galaxy. The absorbing properties of extraplanar dust structures in NGC 891 are best fit with RV ? AV /E(B ? V) = 3.6 ± 0.4. A comparison of the new WIYN images with an archival Hubble Space Telescope image of the central region of NGC 891 suggests that the quantities we measure for the extraplanar dust features are not seriously affected by atmospheric blurring in the WIYN images. Some of the dust features seen in NGC 891 suggest supernova-driven galactic fountain or chimney phenomena are responsible for their production and are clearly associated with ionized gas structures thought to be tracing the violent disk-halo interface of this galaxy. However, other structures are not so readily associated with

J. Christopher Howk; Blair D. Savage

1997-01-01T23:59:59.000Z

413

Direct observation of dynamics of single spinning dust grains in weakly magnetized complex plasma  

SciTech Connect

The rotational dynamics of single dust grains in a weak magnetic field is investigated on a kinetic level. Experiments reveal spin-up of spherical dust grains and alignment of their magnetic moments parallel to the magnetic induction vector. The angular velocity of spinning prolate grains varies as magnetic induction increases to 250 G. Spinning dust grains are found to flip over only when the magnetic field magnitude is changing. The results demonstrate that dusty plasma has paramagnetic properties. Qualitative interpretations are proposed to explain newly discovered phenomena.

Dzlieva, E. S.; Karasev, V. Yu., E-mail: plasmadust@yandex.ru [St. Petersburg State University, Institute of Physics (Russian Federation); Petrov, O. F. [Russian Academy of Sciences, Institute for High Energy Densities, Joint Institute for High Temperatures (Russian Federation)

2012-01-15T23:59:59.000Z

414

African Dust Influence on Atlantic Hurricane Activity and the Peculiar Behaviour of Category 5 Hurricanes  

E-Print Network (OSTI)

We study the specific influence of African dust on each one of the categories of Atlantic hurricanes. By applying wavelet analysis, we find a strong decadal modulation of African dust on Category 5 hurricanes and an annual modulation on all other categories of hurricanes. We identify the formation of Category 5 hurricanes occurring mainly around the decadal minimum variation of African dust and in deep water areas of the Atlantic Ocean, where hurricane eyes have the lowest pressure. According to our results, future tropical cyclones will not evolve to Category 5 until the next decadal minimum that is, by the year 2015 +/- 2.

Herrera, Victor M Velasco; H., Graciela Velasco; Gonzalez, Laura Luna

2010-01-01T23:59:59.000Z

415

Water uptake of clay and desert dust aerosol particles at sub- and supersaturated water vapor conditions  

SciTech Connect

Airborne mineral dust particles serve as cloud condensation nuclei (CCN), thereby influencing the formation and properties of warm clouds. It is therefore of particular interest how dust aerosols with different mineralogy behave when exposed to high relative humidity (RH) or supersaturation with respect to liquid water similar to atmospheric conditions. In this study the sub-saturated hygroscopic growth and the supersaturated cloud condensation nucleus activity of pure clays and real desert dust aerosols was determined using a hygroscopicity tandem differential mobility analyzer (HTDMA) and a cloud condensation nuclei counter (CCNC), respectively. Five different illite, montmorillonite and kaolinite clay samples as well as three desert dust samples (Saharan dust (SD), Chinese dust (CD) and Arizona test dust (ATD)) were used. Aerosols were generated both with a wet and a dry disperser and the water uptake was parameterized via the hygroscopicity parameter, ?. The hygroscopicity of dry generated dust aerosols was found to be negligible when compared to processed atmospheric aerosols, with CCNC derived ? values between 0.00 and 0.02. The latter value can be idealized as a particle consisting of 96.7% (by volume) insoluble material and ~3.3% ammonium sulfate. Pure clay aerosols were found to be generally less hygroscopic than real desert dust particles. All illite and montmorillonite samples had ?~0.003, kaolinites were least hygroscopic and had ?=0.001. SD (?=0.023) was found to be the most hygroscopic dry-generated desert dust followed by CD (?=0.007) and ATD (?=0.003). Wet-generated dust showed an increased water uptake when compared to dry-generated samples. This is considered to be an artifact introduced by redistribution of soluble material between the particles while immersed in an aqueous medium during atomization, thus indicating that specification of the generation method is critically important when presenting such data. Any atmospheric processing of fresh mineral dust which leads to the addition of more than ~3% soluble material is expected to significantly enhance hygroscopicity and CCN activity.

Herich, Hanna; Tritscher, Torsten; Wiacek, Aldona; Gysel, Martin; Weingartner, E.; Lohmann, U.; Baltensperger, Urs; Cziczo, Daniel J.

2009-11-01T23:59:59.000Z

416

Ion beam driven ion-acoustic waves in a plasma cylinder with negatively charged dust grains  

SciTech Connect

An ion beam propagating through a magnetized potassium plasma cylinder having negatively charged dust grains drives electrostatic ion-acoustic waves to instability via Cerenkov interaction. The phase velocity of sound wave increases with the relative density of negatively charged dust grains. 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 as one-third power of the beam density. The real part of frequency of the unstable mode increases with the beam energy and scales as almost the one-half power of the beam energy.

Sharma, Suresh C.; Walia, Ritu [Department of Physics, Maharaja Agrasen Institute of Technology, PSP Area Plot No.-1, Sector-22, Rohini, Delhi 110 086 (India); Sharma, Kavita [Department of Physics, Bhagwan Parshuram Institute of Technology, Sector-17, Rohini, New Delhi 110 089 (India)

2012-07-15T23:59:59.000Z

417

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 directi...

Neklyudov, I M; Fedorova, L I; Poltinin, P Ya

2013-01-01T23:59:59.000Z

418

Physical and Chemical Characterization of Kuwaiti Atmospheric Dust and Synthetic Dusts: Effects on the Pressure Drop and Fractional Efficiency of HEPA Filters  

E-Print Network (OSTI)

The importance of clean air to the indoor air quality affecting the well-being of human occupants and rising energy consumption has highlighted the critical role of air filter performance. Actual performance of air filters installed in air handling units in Kuwait tends to deviate from the performance predicted by laboratory results. Therefore, accurate filter performance prediction is important to estimate filter lifetime, and to reduce energy and maintenance operating costs. To ensure appropriate filter selection for a specific application, particulate contaminants existing in the Kuwaiti atmospheric dust were identified and characterized both physically and chemically and compared to the synthetic dust used in laboratories. This paper compares the physical and chemical characterization Kuwaiti atmospheric dust with the available commercial synthetic dusts. It also tests full scale HEPA pleated V-shaped filters used in Heating Ventilation and Air Conditioning (HVAC) and gas turbine applications to study the effect of different synthetic dust types and their particle size distributions on the pressure drop and fractional efficiency using DEHS testing according to DIN 1822.

Al-Attar, I.; Wakeman, R. J.; Tarleton, E. S.; Husain, A.

2010-01-01T23:59:59.000Z

419

CO2 Emissions - Puerto Rico  

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

Central America, South America, and the Caribbean Nations Puerto Rico Graphics CO2 Emissions from Puerto Rico Data graphic Data CO2 Emissions from Puerto Rico image Per capita...

420

BPA SF6 Emission Info  

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

BPA SF 6 Emission Info Steve Lowder - 2012.12 slide 1 Discovering Emission Locations slide 2 BPA uses a FLIR leak detection camera (other methods available) Allows leaks to...

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

Fabrication of Lamellar Ceramic Recuperator Using a Fugitive ...  

Science Conference Proceedings (OSTI)

... of this study is to demonstrate a CERAMIC recuperator based on toughened mullite, which is a key component of a high efficiency, all-ceramic micro-turbine.

422

ELECTRON EMISSION REGULATING MEANS  

DOE Patents (OSTI)

>An electronic regulating system is described for controlling the electron emission of a cathode, for example, the cathode in a mass spectrometer. The system incorporates a transformer having a first secondary winding for the above-mentioned cathode and a second secondary winding for the above-mentioned cathode and a second secondary winding load by grid controlled vacuum tubes. A portion of the electron current emitted by the cathode is passed through a network which develops a feedback signal. The system arrangement is completed by using the feedback signal to control the vacuum tubes in the second secondary winding through a regulator tube. When a change in cathode emission occurs, the feedback signal acts to correct this change by adjusting the load on the transformer.

Brenholdt, I.R.

1957-11-19T23:59:59.000Z

423

Global emissions inventories  

SciTech Connect

Atmospheric chemistry determines the concentrations of most of the important greenhouse gases except for carbon dioxide. The rate of removal of the greenhouse gases from the atmosphere is also controlled by atmospheric chemistry. The indirect effects of chemical forcing resulting from the chemical interactions of other species can also affect the concentrations of radiatively important gases such as ozone. In order to establish the contribution of any possible climatic change attributable to individual greenhouse gases, spatially and temporally resolved estimates of their emissions need to be established. Unfortunately, for most of the radiatively important species the global magnitudes of their individual fluxes are not known to better than a factor of two and their spatial distributions are even more poorly characterized. Efforts to estimate future projections of potential impacts and to monitor international agreements will require continued research to narrow the uncertainties of magnitude and geographical distribution of emissions.

Dignon, J.

1995-07-01T23:59:59.000Z

424

Diesel hybridization and emissions.  

DOE Green Energy (OSTI)

The CTR Vehicle Systems and Fuels team a diesel hybrid powertrain. The goal of this experiment was to investigate and demonstrate the potential of diesel engines for hybrid electric vehicles (HEVs) in a fuel economy and emissions. The test set-up consisted of a diesel engine coupled to an electric motor driving a Continuously Variable Transmission (CVT). This hybrid drive is connected to a dynamometer and a DC electrical power source creating a vehicle context by combining advanced computer models and emulation techniques. The experiment focuses on the impact of the hybrid control strategy on fuel economy and emissions-in particular, nitrogen oxides (NO{sub x}) and particulate matter (PM). The same hardware and test procedure were used throughout the entire experiment to assess the impact of different control approaches.

Pasquier, M.; Monnet, G.

2004-04-21T23:59:59.000Z

425

Greenhouse gas emissions in biogas production systems  

E-Print Network (OSTI)

Cameron KC. Nitrous oxide emissions from two dairy pastureand land use on N 2 O emissions from an imperfectly drainedoptions for N 2 O emissions from differently managed

Dittert, Klaus; Senbayram, Mehmet; Wienforth, Babette; Kage, Henning; Muehling, Karl H

2009-01-01T23:59:59.000Z

426

CO2 Emissions - Libyan Arab Jamahiriyah  

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

Africa Libyan Arab Jamahiriyah Graphics CO2 Emissions from Libyan Arab Jamahiriyah Data graphic Data CO2 Emissions from Libyan Arab Jamahiriyah image Per capita CO2 Emission...

427

Continuous Emissions Monitoring Guidelines  

Science Conference Proceedings (OSTI)

Since the 2002 update of this manual, the Environmental Protection Agency (EPA) has been extremely active in its efforts to expand continuous emissions monitoring (CEM) requirements through a variety of regulatory instruments. Additional monitoring requirements have resulted from EPA's Clean Air Interstate Rule and Cross-State Air Pollution Rule. EPA attempted to impose mercury (Hg) monitoring requirements in its now-vacated Clean Air Mercury Rule. Most recently, EPA has proposed mercury, particulate mat...

2011-12-20T23:59:59.000Z

428

Trace element emissions  

SciTech Connect

The Energy & Environmental Research Center (EERC) is carrying out an investigation that will provide methods to predict the fate of selected trace elements in integrated gasification combined cycle (IGCC) and integrated gasification fuel cell (IGFC) systems to aid in the development of methods to control the emission of trace elements determined to be air toxics. The goal of this project is to identify the effects of critical chemical and physical transformations associated with trace element behavior in IGCC and IGFC systems. The trace elements included in this project are arsenic, chromium, cadmium, mercury, nickel, selenium, and lead. The research seeks to identify and fill, experimentally and/or theoretically, data gaps that currently exist on the fate and composition of trace elements. The specific objectives are to (1) review the existing literature to identify the type and quantity of trace elements from coal gasification systems, (2) perform laboratory-scale experimentation and computer modeling to enable prediction of trace element emissions, and (3) identify methods to control trace element emissions.

Benson, S.A.; Erickson, T.A.; Steadman, E.N.; Zygarlicke, C.J.; Hauserman, W.B.; Hassett, D.J.

1994-10-01T23:59:59.000Z

429

Tracking shocked dust: State estimation for a complex plasma during a shock wave  

SciTech Connect

We consider a two-dimensional complex (dusty) plasma crystal excited by an electrostatically-induced shock wave. Dust particle kinematics in such a system are usually determined using particle tracking velocimetry. In this work we present a particle tracking algorithm which determines the dust particle kinematics with significantly higher accuracy than particle tracking velocimetry. The algorithm uses multiple extended Kalman filters to estimate the particle states and an interacting multiple model to assign probabilities to the different filters. This enables the determination of relevant physical properties of the dust, such as kinetic energy and kinetic temperature, with high precision. We use a Hugoniot shock-jump relation to calculate a pressure-volume diagram from the shocked dust kinematics. Calculation of the full pressure-volume diagram was possible with our tracking algorithm, but not with particle tracking velocimetry.

Oxtoby, Neil P.; Ralph, Jason F.; Durniak, Celine; Samsonov, Dmitry [Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ (United Kingdom)

2012-01-15T23:59:59.000Z

430

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

Science Conference Proceedings (OSTI)

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

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

2007-02-01T23:59:59.000Z

431

The WIRED Survey. IV. New Dust Disks from the McCook & Sion White Dwarf Catalog  

E-Print Network (OSTI)

We have compiled photometric data from the Wide-field Infrared Survey Explorer All Sky Survey and other archival sources for the more than 2200 objects in the original McCook & Sion Catalog of Spectroscopically Identified White Dwarfs. We applied color-selection criteria to identify 28 targets whose infrared spectral energy distributions depart from the expectation for the white dwarf photosphere alone. Seven of these are previously known white dwarfs with circumstellar dust disks, five are known central stars of planetary nebulae, and six were excluded for being known binaries or having possible contamination of their infrared photometry. We fit white dwarf models to the spectral energy distributions of the remaining ten targets, and find seven new candidates with infrared excess suggesting the presence of a circumstellar dust disk. We compare the model dust disk properties for these new candidates with a comprehensive compilation of previously published parameters for known white dwarfs with dust disks....

Hoard, D W; Wachter, Stefanie; Leisawitz, David T; Cohen, Martin

2013-01-01T23:59:59.000Z

432

Tanpopo cosmic dust collector: Silica aerogel production and bacterial DNA contamination analysis  

E-Print Network (OSTI)

Hydrophobic silica aerogels with ultra-low densities have been designed and developed as cosmic dust capture media for the Tanpopo mission which is proposed to be carried out on the International Space Station. Glass particles as a simulated cosmic dust with 30 \\mu m in diameter and 2.4 g/cm^3 in density were successfully captured by the novel aerogel at a velocity of 6 km/s. Background levels of contaminated DNA in the ultra-low density aerogel were lower than the detection limit of a polymerase chain reaction assay. These results show that the manufactured aerogel has good performance as a cosmic dust collector and sufficient quality in respect of DNA contamination. The aerogel is feasible for the biological analyses of captured cosmic dust particles in the astrobiological studies.

Tabata, Makoto; Yokobori, Shin-ichi; Kawai, Hideyuki; Takahashi, Jun-ichi; Yano, Hajime; Yamagishi, Akihiko

2011-01-01T23:59:59.000Z

433

ACE-ASIA: Regional Climatic and Atmospheric Chemical Effects of Asian Dust and Pollution  

Science Conference Proceedings (OSTI)

Although continental-scale plumes of Asian dust and pollution reduce the amount of solar radiation reaching the earth's surface and perturb the chemistry of the atmosphere, our ability to quantify these effects has been limited by a lack of ...

John H. Seinfeld; Gregory R. Carmichael; Richard Arimoto; William C. Conant; Frederick J. Brechtel; Timothy S. Bates; Thomas A. Cahill; Antony D. Clarke; Sarah J. Doherty; Piotr J. Flatau; Barry J. Huebert; Jiyoung Kim; Krzysztof M. Markowicz; Patricia K. Quinn; Lynn M. Russell; Philip B. Russell; Atsushi Shimizu; Yohei Shinozuka; Chul H. Song; Youhua Tang; Itsushi Uno; Andrew M. Vogelmann; Rodney J. Weber; Jung-Hun Woo; Xiao Y. Zhang

2004-03-01T23:59:59.000Z

434

Comparison Between Dust Particle Generation In CH4 or CH4/N2 Mixing RF Plasmas  

SciTech Connect

Dust particles have been spontaneously generated either in pure CH4 or in CH4/N2 r.f. plasmas. The dust particle formation results from homogeneous nucleation in the plasma and is detected by laser light scattering (Ar+, {lambda} = 514.5 nm). The temporal and spatial behaviour of dust particles is studied. In pure methane gas, particles are trapped in well defined clouds at the plasma sheath boundaries. In a CH4/N2 mixture, the nitrogen addition leads to an expansion of the clouds. For nitrogen contents higher than 50%, the space between the electrodes is nearly completely filled with dust particles leading to plasma instabilities and a void appears in the center of the discharge. The particles are spherical with diameters in the range 0.8-2 {mu}m. For nitrogen-rich plasmas, the particles growth is improved and leads to a rough shape with an orange-peel-type surface texture.

Pereira, Jeremy; Massereau-Guilbaud, Veronique; Geraud-Grenier, Isabelle; Plain, Andre [LASEP, Faculte des Sciences, Universite d'Orleans, Site de Bourges, rue G.Berger, BP 4043, 18028 Bourges Cedex (France)

2005-10-31T23:59:59.000Z

435

Radiative Forcing of Saharan Dust: GOCART Model Simulations Compared with ERBE Data  

Science Conference Proceedings (OSTI)

This study uses information on Saharan aerosol from a dust transport model to calculate radiative forcing values. The transport model is driven by assimilated meteorological fields from the Goddard Earth Observing System Data Assimilation System. ...

Clark J. Weaver; Paul Ginoux; N. Christina Hsu; Ming-Dah Chou; Joanna Joiner

2002-02-01T23:59:59.000Z

436

Radiative Forcing of a Tropical Direct Circulation by Soil Dust Aerosols  

Science Conference Proceedings (OSTI)

The effect of soil dust aerosols upon the tropical climate is estimated by forcing a simple model of a tropical direct circulation. The model consists of a region vertically mixed by deep convection and a nonconvecting region, for which budgets ...

R. L. Miller; I. Tegen

1999-07-01T23:59:59.000Z

437

Properties of Sharav (Khamsin) Dust–Comparison of Optical and Direct Sampling Data  

Science Conference Proceedings (OSTI)

Simultaneous measurements of optical depth and Size distribution in a dust storm are presented. The measured and derived properties of the aerosol are compared with each other and with other results published in the scientific literature. We ...

Zev Levin; Joachim H. Joseph; Yuri Mekler

1980-04-01T23:59:59.000Z

438

Influence of Mesoscale Dynamics and Turbulence on Fine Dust Transport in Owens Valley  

Science Conference Proceedings (OSTI)

Fine dust particles emitted from Owens (dry) Lake in California documented during the Terrain-Induced Rotor Experiment (T-REX) of 2006 have been examined using surface observations and a mesoscale aerosol model. Air quality stations around Owens (...

Qingfang Jiang; Ming Liu; James D. Doyle

2011-01-01T23:59:59.000Z

439

Simulation of Daily Variation of Suspended Particulate Matter over Delhi: Relative Roles of Vehicular Emission, Dust, and Domestic Appliances  

Science Conference Proceedings (OSTI)

The massive growth in the size and the population of cities over the past few decades has led to serious deterioration in the quality of air. One of the important constituents of airborne pollutants, which is a major health hazard, is suspended ...

P. Goswami; J. Baruah

2008-09-01T23:59:59.000Z

440

Impact of the Desert Dust on the Summer Monsoon System over Southwestern North America  

SciTech Connect

The radiative forcing of dust emitted from the Southwest United States (US) deserts and its impact on monsoon circulation and precipitation over the North America monsoon (NAM) region are simulated using a coupled meteorology and aerosol/chemistry model (WRF-Chem) for 15 years (1995-2009). During the monsoon season, dust has a cooling effect (-0.90 W m{sup -2}) at the surface, a warming effect (0.40 W m{sup -2}) in the atmosphere, and a negative top-of-the-atmosphere (TOA) forcing (-0.50 W m{sup -2}) over the deserts on 24-h average. Most of the dust emitted from the deserts concentrates below 800 hPa and accumulates over the western slope of the Rocky Mountains and Mexican Plateau. The absorption of shortwave radiation by dust heats the lower atmosphere by up to 0.5 K day{sup -1} over the western slope of the Mountains. Model sensitivity simulations with and without dust for 15 summers (June-July-August) show that dust heating of the lower atmosphere over the deserts strengthens the low-level southerly moisture fluxes on both sides of the Sierra Madre Occidental. It also results in an eastward migration of NAM-driven moisture convergence over the western slope of the Mountains. These monsoonal circulation changes lead to a statistically significant increase of precipitation by up to {approx}40% over the eastern slope of the Mountains (Arizona-New Mexico-Texas regions). This study highlights the interaction between dust and the NAM system and motivates further investigation of possible dust feedback on monsoon precipitation under climate change and the megadrought conditions projected for the future.

Zhao, Chun; Liu, Xiaohong; Leung, Lai-Yung R.

2012-04-24T23:59:59.000Z

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

Filamentation instability of current-driven dust ion-acoustic waves in a collisional dusty plasma  

Science Conference Proceedings (OSTI)

A theoretical investigation has been made of the dust ion-acoustic filamentation instability in an unmagnetized current-driven dusty plasma by using the Lorentz transformation formulas. The effect of collision between the charged particles with neutrals and their thermal motion on this instability is considered. Developing the filamentation instability of the current-driven dust ion-acoustic wave allows us to determine the period and the establishment time of the filamentation structure and threshold for instability development.

Niknam, A. R. [Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran 19839-63113 (Iran, Islamic Republic of); Haghtalab, T.; Khorashadizadeh, S. M. [Physics Department, Birjand University, Birjand 97179-63384 (Iran, Islamic Republic of)

2011-11-15T23:59:59.000Z

442

Dust and Ventilation Effects on Radiant Barriers: Cooling Season Energy Measurements  

Science Conference Proceedings (OSTI)

This study on the effects of attic ventilation area and type and dust buildup on horizontal and truss radiant barriers in insulated homes can help utilities reduce cooling season electric energy requirements. Increasing the ventilation area ratio and changing ventilation types had little effect on radiant barrier performance. Dust did degrade performance, but insulated homes with radiant barriers still had lower energy requirements than those without radiant barriers.

1990-05-15T23:59:59.000Z

443

EIA - AEO2010 - Emissions projections  

Gasoline and Diesel Fuel Update (EIA)

Emissions Projections Emissions Projections Annual Energy Outlook 2010 with Projections to 2035 Emissions Projections Figure 93. Carbon dioxide emissions by sector and fuel, 2008 and 2035 Click to enlarge » Figure source and data excel logo Figure 94. Sulfur dioxide emissions from electricity generation, 2000-2035 Click to enlarge » Figure source and data excel logo Figure 95. Nitrogen oxide emissions from electricity generation, 2000-2035 Click to enlarge » Figure source and data excel logo Growth of carbon dioxide emissions slows in the projections Federal and State energy policies recently enacted will stimulate increased use of renewable technologies and efficiency improvements in the future, slowing the growth of energy-related CO2 emissions through 2035. In the Reference case, emissions do not exceed pre-recession 2007 levels until 2025. In 2035, energy-related CO2 emissions total 6,320 million metric tons, about 6 percent higher than in 2007 and 9 percent higher than in 2008 (Figure 93). On average, emissions in the Reference case grow by 0.3 percent per year from 2008 to 2035, compared with 0.7 percent per year from 1980 to 2008.

444

Linear trap with three orthogonal quadrupole fields for dust charging experiments  

SciTech Connect

Investigations of charging processes on a single dust grain under controlled conditions in laboratory experiments are the unique way to understand the behavior of dust grains in complex plasma (in space, in laboratory, or in technological applications). An electrodynamic trap is often utilized for both holding a single grain and continuously measuring its charge-to-mass ratio. We propose a modified design of the linear quadrupole trap with the electrodes split into two parts; each of them being supplied by a designated source. The paper presents basic calculations and the results of the trap prototype tests. These tests have confirmed our expectations and have shown that the suggested solution is fully applicable for the dust charging experiments. The uncertainty of determination of the dust grain charge does not exceed 10{sup -3}. The main advantages of the suggested design in comparison with other traps used for dust investigations can be summarized as: The trap (i) is more opened, thus it is suitable for a simultaneous application of the ion and electron beams and UV source; (ii) facilitates investigations of dust grains in a broader range of parameters; and (iii) allows the grain to move along the axis in a controlled way.

Beranek, Martin; Nemecek, Zdenek; Safrankova, Jana; Jerab, Martin; Pavlu, Jiri [Charles University, Faculty of Mathematics and Physics, Prague (Czech Republic); Cermak, Ivo [CGC Instruments, Chemnitz (Germany)

2012-11-15T23:59:59.000Z

445

Evolution of Thermally Pulsing Asymptotic Giant Branch Stars III. Dust production at supersolar metallicities  

E-Print Network (OSTI)

We extend the formalism presented in our recent calculations of dust ejecta from the Thermally Pulsing Asymptotic Giant Branch (TP-AGB) phase, to the case of super-solar metallicity stars. The TP-AGB evolutionary models are computed with the COLIBRI code. We adopt our preferred scheme for dust growth. For M-giants, we neglect chemisputtering by H$_2$ molecules and, for C-stars we assume a homogeneous growth scheme which is primarily controlled by the carbon over oxygen excess. At super-solar metallicities, dust forms more efficiently and silicates tend to condense significantly closer to the photosphere (r~1.5 R$_*$) - and thus at higher temperatures and densities - than at solar and sub-solar metallicities (r~2-3 R$_*$). In such conditions, the hypothesis of thermal decoupling between gas and dust becomes questionable, while dust heating due to collisions plays an important role. The heating mechanism delays dust condensation to slightly outer regions in the circumstellar envelope. We find that the same mech...

Nanni, Ambra; Marigo, Paola; Girardi, Léo

2013-01-01T23:59:59.000Z

446

Quantifying the Impact of Dust on Heterogeneous Ice Generation in Midlevel Supercooled Stratiform Clouds  

Science Conference Proceedings (OSTI)

Dust aerosols have been regarded as effective ice nuclei (IN), but large uncertainties regarding their efficiencies remain. Here, four years of collocated CALIPSO and CloudSat measurements are used to quantify the impact of dust on heterogeneous ice generation in midlevel supercooled stratiform clouds (MSSCs) over the ‘dust belt’. The results show that the dusty MSSCs have an up to 20% higher mixed-phase cloud occurrence, up to 8 dBZ higher mean maximum Ze (Ze_max), and up to 11.5 g/m2 higher ice water path (IWP) than similar MSSCs under background aerosol conditions. Assuming similar ice growth and fallout history in similar MSSCs, the significant differences in Ze_max between dusty and non-dusty MSSCs reflect ice particle number concentration differences. Therefore, observed Ze_max differences indicate that dust could enhance ice particle concentration in MSSCs by a factor of 2 to 6 at temperatures colder than ?12°C. The enhancements are strongly dependent on the cloud top temperature, large dust particle concentration and chemical compositions. These results imply an important role of dust particles in modifying mixed-phase cloud properties globally.

Zhang, Damao; Wang, Zhien; Heymsfield, Andrew J.; Fan, Jiwen; Liu, Dong; Zhao, Ming

2012-09-26T23:59:59.000Z

447

Environmental software systems for emission inventories  

Science Conference Proceedings (OSTI)

Atmospheric emission inventories are important tools for environmental decision making. The need to include transparency and reproducibility in emission calculation also fostered the development of environmental software systems for emission inventories. ... Keywords: Emission inventory theory, Model validation, Upper Austria

Wilfried Winiwarter; Gerald Schimak

2005-12-01T23:59:59.000Z

448

Brownian Motion of Stars, Dust, and Invisible Matter  

E-Print Network (OSTI)

Treating the motion of a dust particle suspended in a liquid as a random walk, Einstein in 1905 derived an equation describing the diffusion of the particle's probability distribution in configuration space. Fokker and Planck extended this work to describe the velocity distribution of the particles. Their equation and its solutions have been applied to many problems in nature starting with the motion of Brownian particles in a liquid. Chandrasekhar derived the Fokker-Planck equation for stars and showed that long-range gravitational encounters provide a drag force, dynamical friction, which is important in the evolution of star clusters and the formation of galaxies. In certain circumstances, Fokker-Planck evolution also describes the evolution of dark (invisible) matter in the universe. In the early universe, the thermal decoupling of weakly interacting massive particles from the plasma of relativistic leptons and photons is governed by Fokker-Planck evolution. The resulting dissipation imprints a minimum length scale for cosmic density fluctuations. Still later, these density fluctuations produce stochastic gravitational forces on the dark matter as it begins to cluster under gravity. The latter example provides an exact derivation of the Fokker-Planck equation without the usual assumption of Markovian dynamics.

Edmund Bertschinger

2006-08-28T23:59:59.000Z

449

WORLD TRADE CENTER INDOOR DUST TEST AND CLEAN PROGRAM PLAN  

E-Print Network (OSTI)

Background: This Test and Clean Program plan is the result of ongoing efforts to monitor the current environmental conditions for residents and workers impacted by the collapse of the World Trade Center (WTC) towers. In March 2004, EPA convened an expert technical review panel to provide individual guidance and assistance to the Agency in its use of available exposure and health surveillance databases and registries to characterize any remaining exposures and risks, identify unmet public health needs, and to individually recommend steps to further minimize the risks associated with the aftermath of the WTC attack. The WTC Expert Technical Review Panel (WTC Panel) members met periodically in open meetings to interact with EPA and the public about plans to monitor for the presence of WTC dust in indoor environments and to individually suggest additional measures that could be undertaken by EPA and others to evaluate the dispersion of the plume and the geographic extent of environmental impact from the collapse of the WTC towers. The WTC Panel members were charged, in part, with reviewing data from post-cleaning verification sampling to be done by EPA in the residential areas included in EPA Region 2's 2002-3 Indoor Air Residential Assistance Program to verify that recontamination has not

unknown authors

2005-01-01T23:59:59.000Z

450

LOWER MANHATTAN INDOOR DUST TEST AND CLEAN PROGRAM PLAN  

E-Print Network (OSTI)

Background: This Test and Clean Program plan is the result of ongoing efforts to respond to concerns of residents and workers impacted by the collapse of the World Trade Center (WTC) towers. In March 2004, EPA convened an expert technical review panel to provide individual guidance and assistance to the Agency in its use of available exposure and health surveillance databases and registries to characterize any remaining exposures and risks, identify unmet public health needs, and individually recommend steps to further minimize the risks associated with the aftermath of the WTC attack. The WTC Expert Technical Review Panel (WTC Panel) members met periodically in open meetings to interact with EPA and the public about plans to monitor for the presence of WTC dust in indoor environments and to individually suggest additional measures that could be undertaken by EPA and others to evaluate the dispersion of the plume and the geographic extent of environmental impact from the collapse of the WTC towers. The WTC Panel members were charged, in part, with reviewing data from post-cleaning verification sampling to be done by EPA in the residential areas included in EPA Region 2's 2002-2003 Indoor Air Residential Assistance Program to verify that recontamination has not

unknown authors

2006-01-01T23:59:59.000Z

451

Asymptotic analysis of perturbed dust cosmologies to second order  

E-Print Network (OSTI)

Nonlinear perturbations of Friedmann-Lemaitre cosmologies with dust and a positive cosmological constant have recently attracted considerable attention. In this paper our first goal is to compare the evolution of the first and second order perturbations by determining their asymptotic behaviour at late times in ever-expanding models. We show that in the presence of spatial curvature K or a positive cosmological constant, the density perturbation approaches a finite limit both to first and second order, but the rate of approach depends on the model, being power law in the scale factor if the cosmological constant is positive but logarithmic if it is zero and and Kdoes not die away, i.e. it contributes on an equal footing as the growing mode to the asymptotic expression for the density perturbation. On the other hand, the future asymptotic regime of the Einstein-de Sitter universe (for which the cosmological constant and the spatial curvature are both zero) is completely different, as exemplified by the density perturbation which diverges; moreover, the second order perturbation diverges faster than the first order perturbation, which suggests that the Einstein-de Sitter universe is unstable to perturbations, and that the perturbation series do not converge towards the future. We conclude that the presence of spatial curvature or a cosmological constant stabilizes the perturbations. Our second goal is to derive an explicit expression for the second order density perturbation that can be used to study the effects of including a cosmological constant and spatial curvature.

Claes Uggla; John Wainwright

2013-03-19T23:59:59.000Z

452

Electrostatic Transport and Manipulation of Lunar Soil and Dust  

SciTech Connect

Transport and manipulation technologies of lunar soil and dust are under development utilizing the electrostatic force. Transport of particles is realized by an electrostatic conveyer consisting of parallel electrodes. Four-phase traveling electrostatic wave was applied to the electrodes to transport particles upon the conveyer and it was demonstrated that particles were efficiently transported under conditions of low frequency, high voltage, and the application of rectangular wave. Not only linear but also curved and closed transport was demonstrated. Numerical investigation was carried out with a three-dimensional hard-sphere model of the Distinct Element Method to clarify the mechanism of the transport and to predict performances in the lunar environment. This technology is expected to be utilized not only for the transport of bulk soil but also for the cleaning of a solar panel and an optical lens. Another technology is an electrostatic manipulation system to manipulate single particle. A manipulator consisted of two parallel pin electrodes. When voltage was applied between the electrodes, electrophoresis force generated in non-uniform electrostatic field was applied to the particle near the tip of the electrode. The particle was captured by the application of the voltage and released from the manipulator by turning off the voltage. It was possible to manipulate not only insulative but also conductive particles. Three-dimensional electrostatic field calculation was conducted to calculate the electrophoresis force and the Coulomb force.

Kawamoto, Hiroyuki [Department of Applied Mechanics and Aerospace Engineering, Waseda University 3-4-1, Okubo, Shinjuku, Tokyo 169-8555 (Japan)

2008-01-21T23:59:59.000Z

453

Positron Emission Tomography (PET)  

DOE R&D Accomplishments (OSTI)

Positron emission tomography (PET) assesses biochemical processes in the living subject, producing images of function rather than form. Using PET, physicians are able to obtain not the anatomical information provided by other medical imaging techniques, but pictures of physiological activity. In metaphoric terms, traditional imaging methods supply a map of the body's roadways, its, anatomy; PET shows the traffic along those paths, its biochemistry. This document discusses the principles of PET, the radiopharmaceuticals in PET, PET research, clinical applications of PET, the cost of PET, training of individuals for PET, the role of the United States Department of Energy in PET, and the futures of PET.

Welch, M. J.

1990-01-00T23:59:59.000Z

454

EIA - Greenhouse Gas Emissions Overview  

Gasoline and Diesel Fuel Update (EIA)

1. Greenhouse Gas Emissions Overview 1. Greenhouse Gas Emissions Overview 1.1 Total emissions Total U.S. anthropogenic (human-caused) greenhouse gas emissions in 2009 were 5.8 percent below the 2008 total (Table 1). The decline in total emissions-from 6,983 million metric tons carbon dioxide equivalent (MMTCO2e) in 2008 to 6,576 MMTCO2e in 2009-was the largest since emissions have been tracked over the 1990-2009 time frame. It was largely the result of a 419-MMTCO2e drop in carbon dioxide (CO2) emissions (7.1 percent). There was a small increase of 7 MMTCO2e (0.9 percent) in methane (CH4) emissions, and an increase of 8 MMTCO2e (4.9 percent), based on partial data, in emissions of man-made gases with high global warming potentials (high-GWP gases). (Draft estimates for emissions of HFC and PFC

455

Zero emission coal  

DOE Green Energy (OSTI)

We discuss a novel, emission-free process for producing hydrogen or electricity from coal. Even though we focus on coal, the basic design is compatible with any carbonaceous fuel. The process uses cyclical carbonation of calcium oxide to promote the production of hydrogen from carbon and water. The carbonation of the calcium oxide removes carbon dioxide from the reaction products and provides the additional energy necessary to complete hydrogen production without additional combustion of carbon. The calcination of the resulting calcium carbonate is accomplished using the high temperature waste heat from solid oxide fuel cells (SOFC), which generate electricity from hydrogen fuel. Converting waste heat back to useful chemical energy allows the process to achieve very high conversion efficiency from fuel energy to electrical energy. As the process is essentially closed-loop, the process is able to achieve zero emissions if the concentrated exhaust stream of CO{sub 2} is sequestered. Carbon dioxide disposal is accomplished by the production of magnesium carbonate from ultramafic rock. The end products of the sequestration process are stable naturally occurring minerals. Sufficient rich ultramafic deposits exist to easily handle all the world's coal.

Ziock, H.; Lackner, K.

2000-08-01T23:59:59.000Z

456

Just the Basics: Vehicle Emissions  

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

Are Exhaust Are Exhaust Emissions? In most heavily settled areas of the U.S., the personal automobile is the single greatest producer of harmful vehicle exhaust emissions. Exhaust emissions are generated by the fuel-air mixture burning in internal combus- tion engines, both gasoline-powered and diesel-powered. Emissions are also produced by fuel evaporation within the vehicle when it is stopped, and again during fueling. The constituents of car (gasoline and diesel) and truck (diesel) emissions vary depending on fuel type and indi- vidual vehicle operating characteris- tics. The bulk of vehicular emissions are composed of water vapor, carbon dioxide, nitrogen, and oxygen (in unconsumed air). There are other pollutants, such as carbon monoxide, nitrogen oxides, unburned fuel, and

457

FRAGMENTATION AND EVOLUTION OF MOLECULAR CLOUDS. III. THE EFFECT OF DUST AND GAS ENERGETICS  

SciTech Connect

Dust and gas energetics are incorporated into a cluster-scale simulation of star formation in order to study the effect of heating and cooling on the star formation process. We build on our previous work by calculating separately the dust and gas temperatures. The dust temperature is set by radiative equilibrium between heating by embedded stars and radiation from dust. The gas temperature is determined using an energy-rate balance algorithm which includes molecular cooling, dust-gas collisional energy transfer, and cosmic-ray ionization. The fragmentation proceeds roughly similarly to simulations in which the gas temperature is set to the dust temperature, but there are differences. The structure of regions around sink particles has properties similar to those of Class 0 objects, but the infall speeds and mass accretion rates are, on average, higher than those seen for regions forming only low-mass stars. The gas and dust temperature have complex distributions not well modeled by approximations that ignore the detailed thermal physics. There is no simple relationship between density and kinetic temperature. In particular, high-density regions have a large range of temperatures, determined by their location relative to heating sources. The total luminosity underestimates the star formation rate at these early stages, before ionizing sources are included, by an order of magnitude. As predicted in our previous work, a larger number of intermediate-mass objects form when improved thermal physics is included, but the resulting initial mass function (IMF) still has too few low-mass stars. However, if we consider recent evidence on core-to-star efficiencies, the match to the IMF is improved.

Martel, Hugo [Departement de Physique, de Genie Physique et d'Optique, Universite Laval, Quebec, QC, G1V 0A6 (Canada); Urban, Andrea [Sapling Learning, Inc., 2815 Exposition Blvd, Austin, TX 78703 (United States); Evans, Neal J. II [Department of Astronomy, University of Texas, 2515 Speedway, Stop C1400, Austin, TX 78712-1205 (United States)

2012-09-20T23:59:59.000Z

458

Fuel Mix and Emissions Disclosure  

Energy.gov (U.S. Department of Energy (DOE))

As part of the state's 1997 electric utility restructuring legislation, Illinois established provisions for the disclosure of fuel mix and emissions data. All electric utilities and alternative...