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Note: This page contains sample records for the topic "aerosol mass spectrometer" from the National Library of EnergyBeta (NLEBeta).
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1

Atmospheric pressure flow reactor / aerosol mass spectrometer studies of tropospheric aerosol nucleat and growth kinetics. Final report, June, 2001  

Science Conference Proceedings (OSTI)

The objective of this program was to determine the mechanisms and rates of growth and transformation and growth processes that control secondary aerosol particles in both the clear and polluted troposphere. The experimental plan coupled an aerosol mass spectrometer (AMS) with a chemical ionization mass spectrometer to provide simultaneous measurement of condensed and particle phases. The first task investigated the kinetics of tropospheric particle growth and transformation by measuring vapor accretion to particles (uptake coefficients, including mass accommodation coefficients and heterogeneous reaction rate coefficients). Other work initiated investigation of aerosol nucleation processes by monitoring the appearance of submicron particles with the AMS as a function of precursor gas concentrations. Three projects were investigated during the program: (1) Ozonolysis of oleic acid aerosols as model of chemical reactivity of secondary organic aerosol; (2) Activation of soot particles by measurement deliquescence in the presence of sulfuric acid and water vapor; (3) Controlled nucleation and growth of sulfuric acid aerosols.

Worsnop, Douglas R.

2001-06-01T23:59:59.000Z

2

Development of Soft Ionization for Particulate Organic Detection with the Aerodyne Aerosol Mass Spectrometer  

SciTech Connect

During this DOE SBIR Phase II project, we have successfully developed several soft ionization techniques, i.e., ionization schemes which involve less fragmentation of the ions, for use with the Aerodyne time-of-flight aerosol mass spectrometer (ToF-AMS). Vacuum ultraviolet single photon ionization was demonstrated in the laboratory and deployed in field campaigns. Vacuum ultraviolet single photon ionization allows better identification of organic species in aerosol particles as shown in laboratory experiments on single component particles, and in field measurements on complex multi-component particles. Dissociative electron attachment with lower energy electrons (less than 30 eV) was demonstrated in the measurement of particulate organics in chamber experiments in Switzerland, and is now a routine approach with AMS systems configured for bipolar, negative ion detection. This technique is particularly powerful for detection of acidic and other highly oxygenated secondary organic aerosol (SOA) chemical functionality. Low energy electron ionization (10 to 12 eV) is also a softer ionization approach routinely available to AMS users. Finally, Lithium ion attachment has been shown to be sensitive to more alkyl-like chemical functionality in SOA. Results from Mexico City are particularly exciting in observing changes in SOA molecular composition under different photochemical/meteorological conditions. More recent results detecting biomass burns at the Montana fire lab have demonstrated quantitative and selective detection of levoglucosan. These soft ionization techniques provide the ToF-AMS with better capability for identifying organic species in ambient atmospheric aerosol particles. This, in turn, will allow more detailed study of the sources, transformations and fate of organic-containing aerosol.

Trimborn, A; Williams, L R; Jayne, J T; Worsnop, D R

2008-06-19T23:59:59.000Z

3

A Compact Lightweight Aerosol Spectrometer Probe (CLASP)  

Science Conference Proceedings (OSTI)

The Compact Lightweight Aerosol Spectrometer Probe (CLASP) is an optical particle spectrometer capable of measuring size-resolved particle concentrations in 16 user-defined size bins spanning diameters in the range 0.24 < D < 18.5 ?m at a rate of ...

Martin K. Hill; Barbara J. Brooks; Sarah J. Norris; Michael H. Smith; Ian M. Brooks; Gerrit de Leeuw

2008-11-01T23:59:59.000Z

4

MASS SPECTROMETER LEAK  

DOE Patents (OSTI)

An improved valve is described for precisely regulating the flow of a sample fluid to be analyzed, such as in a mass spectrometer, where a gas sample is allowed to "leak" into an evacuated region at a very low, controlled rate. The flow regulating valve controls minute flow of gases by allowing the gas to diffuse between two mating surfaces. The structure of the valve is such as to prevent the corrosive feed gas from contacting the bellows which is employed in the operation of the valve, thus preventing deterioration of the bellows.

Shields, W.R.

1960-10-18T23:59:59.000Z

5

Method for calibrating mass spectrometers  

DOE Patents (OSTI)

A method whereby a mass spectra generated by a mass spectrometer is calibrated by shifting the parameters used by the spectrometer to assign masses to the spectra in a manner which reconciles the signal of ions within the spectra having equal mass but differing charge states, or by reconciling ions having known differences in mass to relative values consistent with those known differences. In this manner, the mass spectrometer is calibrated without the need for standards while allowing the generation of a highly accurate mass spectra by the instrument.

Anderson, Gordon A [Benton City, WA; Brands, Michael D [Richland, WA; Bruce, James E [Schwenksville, PA; Pasa-Tolic, Ljiljana [Richland, WA; Smith, Richard D [Richland, WA

2002-12-24T23:59:59.000Z

6

Time of flight mass spectrometer  

DOE Patents (OSTI)

A time-of-flight mass spectrometer is described in which ions are desorbed from a sample by nuclear fission fragments, such that desorption occurs at the surface of the sample impinged upon by the fission fragments. This configuration allows for the sample to be of any thickness, and eliminates the need for complicated sample preparation.

Ulbricht, Jr., William H. (Arvada, CO)

1984-01-01T23:59:59.000Z

7

Organic aerosol components observed in Northern Hemispheric datasets from Aerosol Mass Spectrometry  

E-Print Network (OSTI)

In this study we compile and present results from the factor analysis of 43 Aerosol Mass Spectrometer (AMS) datasets (27 of the datasets are reanalyzed in this work). The components from all sites, when taken together, ...

Kroll, Jesse

8

Advanced Mass Spectrometers for Hydrogen Isotope Analyses  

DOE Green Energy (OSTI)

This report is a summary of the results of a joint Savannah River Laboratory (SRL) - Savannah River Plant (SRP) ''Hydrogen Isotope Mass Spectrometer Evaluation Program''. The program was undertaken to evaluate two prototype hydrogen isotope mass spectrometers and obtain sufficient data to permit SRP personnel to specify the mass spectrometers to replace obsolete instruments.

Chastagner, P.

2001-08-01T23:59:59.000Z

9

Aerosol beam-focus laser-induced plasma spectrometer device  

SciTech Connect

An apparatus for detecting elements in an aerosol includes an aerosol beam focuser for concentrating aerosol into an aerosol beam; a laser for directing a laser beam into the aerosol beam to form a plasma; a detection device that detects a wavelength of a light emission caused by the formation of the plasma. The detection device can be a spectrometer having at least one grating and a gated intensified charge-coupled device. The apparatus may also include a processor that correlates the wavelength of the light emission caused by the formation of the plasma with an identity of an element that corresponds to the wavelength. Furthermore, the apparatus can also include an aerosol generator for forming an aerosol beam from bulk materials. A method for detecting elements in an aerosol is also disclosed.

Cheng, Meng-Dawn (Oak Ridge, TN)

2002-01-01T23:59:59.000Z

10

Miniaturized Mass Spectrometer - Energy Innovation Portal  

Technology Marketing Summary Sandia's invention relates to a miniaturized mass spectrometer using a silicon chip field emitter array as the source of ...

11

Mexico City Aerosol Analysis During Milagro Using High Resolution Aerosol Mass Spectrometry at the Urban Supersite (T0) - Part 1: Fine Particle Composition and Organic Source Apportionment.  

E-Print Network (OSTI)

Submicron aerosol was analyzed during the MILAGRO field campaign in March 2006 at the T0 urban supersite in Mexico City with a High-Resolution Aerosol Mass Spectrometer (AMS) and complementary instrumentation. Positive ...

Aiken, A. C.

12

Compact time-of-flight mass spectrometer  

SciTech Connect

This paper describes a time-of-flight mass spectrometer developed for measuring the parameters of a pulsed hydrogen beam. The duration of an electron-beam current pulse in the ionizer of the mass spectrometer can be varied within 2-20 usec, the pulse electron current is 0.6 mA, and the electron energy is 250 eV. The time resolution of the mass spectrometer is determined by the repetition period of the electron-beam current pulses and is 40 usec. The mass spectrometer has 100% transmission in the direction of motion of molecular-beam particles. The dimension of the mass spectrometer is 7 cm in this direction. The mass resolution is sufficient for determination of the composition of the hydrogen beam.

Belov, A.S.; Kubalov, S.A.; Kuzik, V.F.; Yakushev, V.P.

1986-02-01T23:59:59.000Z

13

Multidetector calibration for mass spectrometers  

SciTech Connect

The International Atomic Energy Agency`s Safeguards Analytical Laboratory has performed calibration experiments to measure the different efficiencies among multi-Faraday detectors for a Finnigan-MAT 261 mass spectrometer. Two types of calibration experiments were performed: (1) peak-shift experiments and (2) peak-jump experiments. For peak-shift experiments, the ion intensities were measured for all isotopes of an element in different Faraday detectors. Repeated measurements were made by shifting the isotopes to various Faraday detectors. Two different peak-shifting schemes were used to measure plutonium (UK Pu5/92138) samples. For peak-jump experiments, ion intensities were measured in a reference Faraday detector for a single isotope and compared with those measured in the other Faraday detectors. Repeated measurements were made by switching back-and-forth between the reference Faraday detector and a selected Faraday detector. This switching procedure is repeated for all Faraday detectors. Peak-jump experiments were performed with replicate measurements of {sup 239}Pu, {sup 187}Re, and {sup 238}U. Detector efficiency factors were estimated for both peak-jump and peak-shift experiments using a flexible calibration model to statistically analyze both types of multidetector calibration experiments. Calculated detector efficiency factors were shown to depend on both the material analyzed and the experimental conditions. A single detector efficiency factor is not recommended for each detector that would be used to correct routine sample analyses. An alternative three-run peak-shift sample analysis should be considered. A statistical analysis of the data from this peak-shift experiment can adjust the isotopic ratio estimates for detector differences due to each sample analysis.

Bayne, C.K. [Oak Ridge National Lab., TN (United States); Donohue, D.L.; Fiedler, R. [IAEA, Seibersdorf (Austria). Safeguards Analytical Lab.

1994-06-01T23:59:59.000Z

14

Gas sampling system for a mass spectrometer  

DOE Patents (OSTI)

The present invention relates generally to a gas sampling system, and specifically to a gas sampling system for transporting a hazardous process gas to a remotely located mass spectrometer. The gas sampling system includes a capillary tube having a predetermined capillary length and capillary diameter in communication with the supply of process gas and the mass spectrometer, a flexible tube surrounding and coaxial with the capillary tube intermediate the supply of process gas and the mass spectrometer, a heat transfer tube surrounding and coaxial with the capillary tube, and a heating device in communication the heat transfer tube for substantially preventing condensation of the process gas within the capillary tube.

Taylor, Charles E; Ladner, Edward P

2003-12-30T23:59:59.000Z

15

Linear Electric Field Time-Of-Flight Ion Mass Spectrometers  

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

Linear Electric Field Time-Of-Flight Ion Mass Spectrometers Linear Electric Field Time-Of-Flight Ion Mass Spectrometers Time-of-flight mass spectrometer comprising a first drift...

16

Relating Secondary Organic Aerosol Characteristics with Cloud Condensation Nuclei Activity  

E-Print Network (OSTI)

and microphysical characterization of ambient aerosols withthe aerodyne aerosol mass spectrometer, Mass Spectrom Rev,of secondary organic aerosol under near atmospheric

Tang, Xiaochen

2013-01-01T23:59:59.000Z

17

Compact hydrogen/helium isotope mass spectrometer  

DOE Patents (OSTI)

The compact hydrogen and helium isotope mass spectrometer of the present invention combines low mass-resolution ion mass spectrometry and beam-foil interaction technology to unambiguously detect and quantify deuterium (D), tritium (T), hydrogen molecule (H.sub.2, HD, D.sub.2, HT, DT, and T.sub.2), .sup.3 He, and .sup.4 He concentrations and concentration variations. The spectrometer provides real-time, high sensitivity, and high accuracy measurements. Currently, no fieldable D or molecular speciation detectors exist. Furthermore, the present spectrometer has a significant advantage over traditional T detectors: no confusion of the measurements by other beta-emitters, and complete separation of atomic and molecular species of equivalent atomic mass (e.g., HD and .sup.3 He).

Funsten, Herbert O. (Los Alamos, NM); McComas, David J. (Los Alamos, NM); Scime, Earl E. (Morgantown, WV)

1996-01-01T23:59:59.000Z

18

Development and performance of a miniature, low cost mass spectrometer  

E-Print Network (OSTI)

A miniature, low cost mass spectrometer has been developed that is capable of unit resolution over a mass range of 10 to 50 AMU. The design of the mass spectrometer incorporates several new features that enhance the ...

Hemond, Brian D. (Brian David Thomson)

2011-01-01T23:59:59.000Z

19

Portable gas chromatograph-mass spectrometer  

DOE Patents (OSTI)

A gas chromatograph-mass spectrometer (GC-MS) for use as a field portable organic chemical analysis instrument. The GC-MS is designed to be contained in a standard size suitcase, weighs less than 70 pounds, and requires less than 600 watts of electrical power at peak power (all systems on). The GC-MS includes: a conduction heated, forced air cooled small bore capillary gas chromatograph, a small injector assembly, a self-contained ion/sorption pump vacuum system, a hydrogen supply, a dual computer system used to control the hardware and acquire spectrum data, and operational software used to control the pumping system and the gas chromatograph. This instrument incorporates a modified commercial quadrupole mass spectrometer to achieve the instrument sensitivity and mass resolution characteristic of laboratory bench top units.

Andresen, B.D.; Eckels, J.D.; Kimmins, J.F.; Myers, D.W.

1994-12-31T23:59:59.000Z

20

Expert overseer for mass spectrometer system  

DOE Patents (OSTI)

An expert overseer for the operation and real-time management of a mass spectrometer and associated laboratory equipment. The overseer is a computer-based expert diagnostic system implemented on a computer separate from the dedicated computer used to control the mass spectrometer and produce the analysis results. An interface links the overseer to components of the mass spectrometer, components of the laboratory support system, and the dedicated control computer. Periodically, the overseer polls these devices and as well as itself. These data are fed into an expert portion of the system for real-time evaluation. A knowledge base used for the evaluation includes both heuristic rules and precise operation parameters. The overseer also compares current readings to a long-term database to detect any developing trends using a combination of statistical and heuristic rules to evaluate the results. The overseer has the capability to alert lab personnel whenever questionable readings or trends are observed and provide a background review of the problem and suggest root causes and potential solutions, or appropriate additional tests that could be performed. The overseer can change the sequence or frequency of the polling to respond to an observation in the current data.

Filby, Evan E. (Idaho Falls, ID); Rankin, Richard A. (Ammon, ID)

1991-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol mass spectrometer" 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

Expert overseer for mass spectrometer system  

DOE Patents (OSTI)

An expert overseer for the operation and real-time management of a mass spectrometer and associated laboratory equipment. The overseer is a computer-based expert diagnostic system implemented on a computer separate from the dedicated computer used to control the mass spectrometer and produce the analysis results. An interface links the overseer to components of the mass spectrometer, components of the laboratory support system, and the dedicated control computer. Periodically, the overseer polls these devices and as well as itself. These data are fed into an expert portion of the system for real-time evaluation. A knowledge base used for the evaluation includes both heuristic rules and precise operation parameters. The overseer also compares current readings to a long-term database to detect any developing trends using a combination of statistical and heuristic rules to evaluate the results. The overseer has the capability to alert lab personnel whenever questionable readings or trends are observed and provide a background review of the problem and suggest root causes and potential solutions, or appropriate additional tests that could be performed. The overseer can change the sequence or frequency of the polling to respond to an observation in the current data.

Filby, E.E.; Rankin, R.A.

1989-04-04T23:59:59.000Z

22

Tropospheric Aerosol Chemistry via Aerosol Mass Spectrometry  

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

chemical information needed to interpret mass spectra. The challenge is to separate primary and secondary; anthropogenic, biogenic and biomass burning sources - and...

23

Linear Electric Field Time-Of-Flight Ion Mass Spectrometers  

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

Linear Electric Field Time-Of-Flight Ion Mass Spectrometers Linear Electric Field Time-Of-Flight Ion Mass Spectrometers Linear Electric Field Time-Of-Flight Ion Mass Spectrometers Time-of-flight mass spectrometer comprising a first drift region and a second drift region enclosed within an evacuation chamber. Available for thumbnail of Feynman Center (505) 665-9090 Email Linear Electric Field Time-Of-Flight Ion Mass Spectrometers Time-of-flight mass spectrometer comprising a first drift region and a second drift region enclosed within an evacuation chamber; a means of introducing an analyte of interest into the first drift region; a pulsed ionization source which produces molecular ions from said analyte of interest; a first foil positioned between the first drift region and the second drift region, which dissociates said molecular ions into constituent

24

Secondary Ion Mass Spectrometry of Environmental Aerosols  

Science Conference Proceedings (OSTI)

Atmospheric particles influence many aspects of climate, air quality and human health. Understanding the composition, chemistry and behavior of atmospheric aerosols is a key remaining challenge in improving climate models. Furthermore, particles may be traced back to a particular source based on composition, stable isotope ratios, or the presence of particular surface chemistries. Finally, the characterization of atmospheric particles in the workplace plays an important role in understanding the potential for exposure and environmental and human health effects to engineered and natural nanoscale particles. Secondary ion mass spectrometry (SIMS) is a useful tool in determining any of several aspects of the structure, composition and chemistry of these particles. Often used in conjunction with other surface analysis and electron microscopy methods, SIMS has been used to determine or confirm reactions on and in particles, the presence of particular organic species on the surface of atmospheric aerosols and several other interesting and relevant findings. Various versions of SIMS instruments – dynamic SIMS, time of flight secondary ion mass spectrometry or TOF-SIMS, nanoSIMS – have been used to determine specific aspects of aerosol structure and chemistry. This article describes the strengths of each type of SIMS instrument in the characterization of aerosols, along with guidance on sample preparation, specific characterization specific to the particular information sought in the analysis. Examples and guidance are given for each type of SIMS analysis.

Gaspar, Daniel J.; Cliff, John B.

2010-08-01T23:59:59.000Z

25

Electron source for a mini ion trap mass spectrometer  

DOE Patents (OSTI)

An ion trap is described which operates in the regime between research ion traps which can detect ions with a mass resolution of better than 1:10{sup 9} and commercial mass spectrometers requiring 10{sup 4} ions with resolutions of a few hundred. The power consumption is kept to a minimum by the use of permanent magnets and a novel electron gun design. By Fourier analyzing the ion cyclotron resonance signals induced in the trap electrodes, a complete mass spectra in a single combined structure can be detected. An attribute of the ion trap mass spectrometer is that overall system size is drastically reduced due to combining a unique electron source and mass analyzer/detector in a single device. This enables portable low power mass spectrometers for the detection of environmental pollutants or illicit substances, as well as sensors for on board diagnostics to monitor engine performance or for active feedback in any process involving exhausting waste products. 10 figs.

Dietrich, D.D.; Keville, R.F.

1995-12-19T23:59:59.000Z

26

Compact mass spectrometer for plasma discharge ion analysis  

DOE Patents (OSTI)

A mass spectrometer and methods are disclosed for mass spectrometry which are useful in characterizing a plasma. This mass spectrometer for determining type and quantity of ions present in a plasma is simple, compact, and inexpensive. It accomplishes mass analysis in a single step, rather than the usual two-step process comprised of ion extraction followed by mass filtering. Ions are captured by a measuring element placed in a plasma and accelerated by a known applied voltage. Captured ions are bent into near-circular orbits by a magnetic field such that they strike a collector, producing an electric current. Ion orbits vary with applied voltage and proton mass ratio of the ions, so that ion species may be identified. Current flow provides an indication of quantity of ions striking the collector. 7 figs.

Tuszewski, M.G.

1997-07-22T23:59:59.000Z

27

Compact mass spectrometer for plasma discharge ion analysis  

DOE Patents (OSTI)

A mass spectrometer and methods for mass spectrometry which are useful in characterizing a plasma. This mass spectrometer for determining type and quantity of ions present in a plasma is simple, compact, and inexpensive. It accomplishes mass analysis in a single step, rather than the usual two-step process comprised of ion extraction followed by mass filtering. Ions are captured by a measuring element placed in a plasma and accelerated by a known applied voltage. Captured ions are bent into near-circular orbits by a magnetic field such that they strike a collector, producing an electric current. Ion orbits vary with applied voltage and proton mass ratio of the ions, so that ion species may be identified. Current flow provides an indication of quantity of ions striking the collector.

Tuszewski, Michel G. (Los Alamos, NM)

1997-01-01T23:59:59.000Z

28

Hydrogen-Isotope Mass-Spectrometer Evaluation Program. Bimonthly progress report, July/September 1982  

SciTech Connect

The joint SRL-SRP Hydrogen Isotope Mass Spectrometer Evaluation Program was undertaken to: (1) evaluate a prototype hydrogen isotope mass spectrometer that was developed for the Mass Spectrometer Technical Group by VG-Isotopes, Ltd., and (2) obtain sufficient data to permit SRP personnel to specify the mass spectrometes that will be purchased under Schedule 44 Budget Project 81-SR-010 to replace obsolete mass spectrometers in Buildings 232-H and 224-H.

Chastagner, P.; Daves, H.L.; Hess, W.B.

1982-01-01T23:59:59.000Z

29

Design and development of an ultrafine particle reflection-time-of-flight mass spectrometer  

E-Print Network (OSTI)

The primary motivation for the research is to study the effect of small particles on global climate. The study can also help to understand the dynamics involved with gas to particle conversion, which is being debated to be a rich source for atmospheric aerosol. However, the most important use would be to study health effects, since small particles easily diffuse into the lungs, with seemingly little physiological filtration mechanism. The research work involves the design, development and characterization of a single-ultrafine-particle mass spectrometer. The instrument aerodynamically size selects fine and ultrafine aerosol particles (size range 20 nm-1 []m), with a constant Stokes number, and focuses them into a vacuum chamber. This is achieved by changing the upstream pressure of the inlet, which changes aerodynamic drag experienced by the particle. After its entry into the chamber, the particle is ablated by a high power excimer laser, which produces ions from the original molecular constituents. Reflectron time-of-flight mass spectrometry is utilized to analyze the ions, and thus the chemical composition of the particle that was hit. The present work is aimed to overcome the shortcomings of previous instruments, while allowing for increased portability. The instrument is designed, fabricated and experimentally characterized. The first phase involves analysis of the particle beam generated by the inlet. An atomizer generates aerosols from a solution of 5% oleic acid and ethanol. The polydisperse aerosol is passed through a differential mobility analyzer to make a monodisperse mixture, which is transmitted through the inlet. The monodisperse particle beam is intercepted by glass slides, and the spot sizes are indicative of the beam shape and width at the slide positions. A theoretical analysis of the fluid flow field and particle trajectory is developed to correlate with the experimental results. The second phase involves calibration of the mass spectra, and measuring some particulate composition from the laboratory room air.

Das, Rishiraj

2002-01-01T23:59:59.000Z

30

Carbon oxidation state as a metric for describing the chemistry of atmospheric organic aerosol  

E-Print Network (OSTI)

Sun, Y. et al. Size-resolved aerosol chemistry on Whistlerwith a high-resolution aerosol mass spectrometer duringBasis Set: 1. Organic-Aerosol Mixing Thermodynamics. Atmos.

Kroll, Jesse H.

2011-01-01T23:59:59.000Z

31

An omegatron mass spectrometer for plasma ion species analysis  

DOE Green Energy (OSTI)

An omegatron mass spectrometer which can be used to measure the ion species and charge state distribution in a magnetized plasma is described. In the conventional omegatron, ions are formed as the result of gas ionization by a fine electron beam passing through the center of the analyzer along the magnetic field. In the plasma omegatron, the plasma ions are entering the analyzer through a small floating aperture. We employ a biasing technique to reduce the ion velocity along the magnetic field and, thus, achieve improved ion collection and sensitivity. Experiments have been performed to demonstrate the instrument's operation in the PISCES-A linear plasma device, at a magnetic field {ital B}=1.3 kG. Mass spectra have been obtained in hydrogen, helium, and nitrogen plasmas, and typical results are presented.

Wang, E.Y.; Schmitz, L.; Ra, Y.; LaBombard, B.; Conn, R.W. (Institute of Plasma and Fusion Research, (USA) Department of Mechanical, Aerospace, and Nuclear Engineering, Los Angeles, CA (USA) University of California, Los Angeles, Los Angeles, CA (USA))

1990-08-01T23:59:59.000Z

32

Seven Channel Multi-collector Isotope Ratio Mass Spectrometer  

Science Conference Proceedings (OSTI)

A new magnetic sector mass spectrometer that utilizes seven full-sized discrete dynode electron multipliers operating simultaneously has been designed, constructed and is in preliminary testing. The instrument utilizes a newly developed ion dispersion lens that enables the mass dispersed individual isotope beams to be separated sufficiently (35 mm) to allow a full-sized discrete dynode pulse counting multiplier to be used for each beam. The ion dispersion lens is a two element electrostatic 90 degree sector device that causes the beam-to-beam dispersion to increase faster than the intra-beam dispersion. Each multiplier is contained in an isolated case with a deflector/condenser lens at the entrance. A 9-sample filament cartridge is mounted on a micro-manipulator two-axis stage that enables adjustment of the filament position with 10 micron resolution within the ion lens. Results of initial testing with actinides will be presented.

Anthony D. Appelhans

2008-07-01T23:59:59.000Z

33

Linear electronic field time-of-flight ion mass spectrometers  

DOE Patents (OSTI)

Time-of-flight mass spectrometer comprising a first drift region and a second drift region enclosed within an evacuation chamber; a means of introducing an analyte of interest into the first drift region; a pulsed ionization source which produces molecular ions from said analyte of interest; a first foil positioned between the first drift region and the second drift region, which dissociates said molecular ions into constituent atomic ions and emits secondary electrons; an electrode which produces secondary electrons upon contact with a constituent atomic ion in second drift region; a stop detector comprising a first ion detection region and a second ion detection region; and a timing means connected to the pulsed ionization source, to the first ion detection region, and to the second ion detection region.

Funsten, Herbert O. (Los Alamos, NM)

2010-08-24T23:59:59.000Z

34

Advances in field-portable mass spectrometers for on-site analytics  

Science Conference Proceedings (OSTI)

Learn how the combination of ambient ionization with portable mass spectroscopy can speed chemical analysis by streamlining sample preparation and throughput requirements. Advances in field-portable mass spectrometers for on-site analytics inform M

35

ARM - Measurement - Aerosol scattering  

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

Spectrometer RL : Raman Lidar Field Campaign Instruments AOS : Aerosol Observing System DRI-GND : Desert Research Institute Ground-Based Aerosol Instruments AEROSOL-TOWER-EML :...

36

A Chemical Ionization Mass Spectrometer for Ground-Based Measurements of Nitric Acid  

Science Conference Proceedings (OSTI)

A chemical ionization mass spectrometer (CIMS) instrument has been developed for high-precision measurements of gaseous nitric acid (HNO3) specifically under high- and variable-humidity conditions in the boundary layer. The instrument’s ...

Kazuyuki Kita; Yu Morino; Yutaka Kondo; Yuichi Komazaki; Nobuyuki Takegawa; Yuzo Miyazaki; Jun Hirokawa; Shigeru Tanaka; Thomas L. Thompson; Ru-Shan Gao; David W. Fahey

2006-08-01T23:59:59.000Z

37

New approaches for the chemical and physical characterization of aerosols using a single particle mass spectrometry based technique  

E-Print Network (OSTI)

mass fractions in particles. Aerosol Science and Technology,mediated lung injury, J. Aerosol Sci. , 29 (5-6), 553-560,from natural to anthropogenic aerosol radiative forcing:

Spencer, Matthew Todd

2007-01-01T23:59:59.000Z

38

Retrieval of Aerosol Mass Concentration from Elastic Lidar Data.  

E-Print Network (OSTI)

??Agricultural aerosol sources can contribute significantly to air pollution in many regions of the country. Characterization of the aerosol emissions of agricultural operations is required… (more)

Marchant, Christian C.

2010-01-01T23:59:59.000Z

39

ARM - Midlatitude Continental Convective Clouds - Ultra High Sensitivity Aerosol Spectrometer(tomlinson-uhsas)  

DOE Data Explorer (OSTI)

Ultra High Sensitivity Aerosol Spectrometer (UHSASA) A major component of the Mid-latitude Continental Convective Clouds Experiment (MC3E) field campaign was the deployment of an enhanced radiosonde array designed to capture the vertical profile of atmospheric state variables (pressure, temperature, humidity wind speed and wind direction) for the purpose of deriving the large-scale forcing for use in modeling studies. The radiosonde array included six sites (enhanced Central Facility [CF-1] plus five new sites) launching radiosondes at 3-6 hour sampling intervals. The network will cover an area of approximately (300)2 km2 with five outer sounding launch sites and one central launch location. The five outer sounding launch sites are: S01 Pratt, KS [ 37.7oN, 98.75oW]; S02 Chanute, KS [37.674, 95.488]; S03 Vici, Oklahoma [36.071, -99.204]; S04 Morris, Oklahoma [35.687, -95.856]; and S05 Purcell, Oklahoma [34.985, -97.522]. Soundings from the SGP Central Facility during MC3E can be retrieved from the regular ARM archive. During routine MC3E operations 4 radiosondes were launched from each of these sites (approx. 0130, 0730, 1330 and 1930 UTC). On days that were forecast to be convective up to four additional launches were launched at each site (approx. 0430, 1030, 1630, 2230 UTC). There were a total of approximately 14 of these high frequency launch days over the course of the experiment. These files contain brightness temperatures observed at Purcell during MC3E. The measurements were made with a 5 channel (22.235, 23.035, 23.835, 26.235, 30.000GHz) microwave radiometer at one minute intervals. The results have been separated into daily files and the day of observations is indicated in the file name. All observations were zenith pointing. Included in the files are the time variables base_time and time_offset. These follow the ARM time conventions. Base_time is the number seconds since January 1, 1970 at 00:00:00 for the first data point of the file and time_offset is the offset in seconds from base_time.

Jason Tomlinson; Mike Jensen

40

ARM - Midlatitude Continental Convective Clouds - Ultra High Sensitivity Aerosol Spectrometer(tomlinson-uhsas)  

SciTech Connect

Ultra High Sensitivity Aerosol Spectrometer (UHSASA) A major component of the Mid-latitude Continental Convective Clouds Experiment (MC3E) field campaign was the deployment of an enhanced radiosonde array designed to capture the vertical profile of atmospheric state variables (pressure, temperature, humidity wind speed and wind direction) for the purpose of deriving the large-scale forcing for use in modeling studies. The radiosonde array included six sites (enhanced Central Facility [CF-1] plus five new sites) launching radiosondes at 3-6 hour sampling intervals. The network will cover an area of approximately (300)2 km2 with five outer sounding launch sites and one central launch location. The five outer sounding launch sites are: S01 Pratt, KS [ 37.7oN, 98.75oW]; S02 Chanute, KS [37.674, 95.488]; S03 Vici, Oklahoma [36.071, -99.204]; S04 Morris, Oklahoma [35.687, -95.856]; and S05 Purcell, Oklahoma [34.985, -97.522]. Soundings from the SGP Central Facility during MC3E can be retrieved from the regular ARM archive. During routine MC3E operations 4 radiosondes were launched from each of these sites (approx. 0130, 0730, 1330 and 1930 UTC). On days that were forecast to be convective up to four additional launches were launched at each site (approx. 0430, 1030, 1630, 2230 UTC). There were a total of approximately 14 of these high frequency launch days over the course of the experiment. These files contain brightness temperatures observed at Purcell during MC3E. The measurements were made with a 5 channel (22.235, 23.035, 23.835, 26.235, 30.000GHz) microwave radiometer at one minute intervals. The results have been separated into daily files and the day of observations is indicated in the file name. All observations were zenith pointing. Included in the files are the time variables base_time and time_offset. These follow the ARM time conventions. Base_time is the number seconds since January 1, 1970 at 00:00:00 for the first data point of the file and time_offset is the offset in seconds from base_time.

Jason Tomlinson; Mike Jensen

2012-02-28T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol mass spectrometer" 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

ARM - Measurement - Aerosol particle size  

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

particle size particle size ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Aerosol particle size Linear size (e.g. radius or diameter) of an aerosol particle. Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. Field Campaign Instruments AEROSMASSSPEC : Aerosol Mass Spectrometer CPI : Cloud Particle Imager DRI-GND : Desert Research Institute Ground-Based Aerosol Instruments DRUM-AEROSOL : Drum Aerosol Sampler AEROSOL-TOWER-EML : EML Tower based Aerosol Measurements

42

Chemical Ionization Mass Spectrometer (CIMS) Shanhu Lee, Kent State University (http://www.personal.kent.edu/~slee19/)  

E-Print Network (OSTI)

Chemical Ionization Mass Spectrometer (CIMS) Shanhu Lee, Kent State University (http ionization mass spectrometry (PTR-CIMS). A typical CIMS instrument can be constructed from an ion source, an ion molecular reactor, and a quadrupole mass spectrometer. Shown below is schematic diagram of a CIMS

Lee, Shan-Hu

43

Reduction in biomass burning aerosol light absorption upon humidification: Roles of inorganically-induced hygroscopicity, particle collapse, and photoacoustic heat and mass transfer  

Science Conference Proceedings (OSTI)

Smoke particle emissions from the combustion of biomass fuels typical for the western and southeastern United States were studied and compared under high humidity and ambient conditions in the laboratory. The fuels used are Montana ponderosa pine (Pinus ponderosa), southern California chamise (Adenostoma fasciculatum), and Florida saw palmetto (Serenoa repens). Information on the non-refractory chemical composition of biomass burning aerosol from each fuel was obtained with an aerosol mass spectrometer and through estimation of the black carbon concentration from light absorption measurements at 870 nm. Changes in the optical and physical particle properties under high humidity conditions were observed for hygroscopic smoke particles containing substantial inorganic mass fractions that were emitted from combustion of chamise and palmetto fuels. Light scattering cross sections increased under high humidity for these particles, consistent with the hygroscopic growth measured for 100 nm particles in HTDMA measurements. Photoacoustic measurements of aerosol light absorption coefficients reveal a 20% reduction with increasing relative humidity, contrary to the expectation of light absorption enhancement by the liquid coating taken up by hygroscopic particles. This reduction is hypothesized to arise from two mechanisms: 1. Shielding of inner monomers after particle consolidation or collapse with water uptake; 2. The contribution of mass transfer through evaporation and condensation at high relative humidity to the usual heat transfer pathway for energy release by laser heated particles in the photoacoustic measurement of aerosol light absorption. The mass transfer contribution is used to evaluate the fraction of aerosol surface covered with liquid water solution as a function of RH.

lewis, Kristen A.; Arnott, W. P.; Moosmuller, H.; Chakrabarti, Raj; Carrico, Christian M.; Kreidenweis, Sonia M.; Day, Derek E.; Malm, William C.; Laskin, Alexander; Jimenez, Jose L.; Ulbrich, Ingrid M.; Huffman, John A.; Onasch, Timothy B.; Trimborn, Achim; Liu, Li; Mishchenko, M.

2009-11-27T23:59:59.000Z

44

Airborne Scanning Spectrometer for Remote Sensing of Cloud, Aerosol, Water Vapor, and Surface Properties  

Science Conference Proceedings (OSTI)

An airborne scanning spectrometer was developed for measuring reflected solar and emitted thermal radiation in 50 narrowband channels between 0.55 and 14.2 µm. The instrument provides multispectral images of outgoing radiation for purposes of ...

Michael D. King; W. Paul Menzel; Patrick S. Grant; Jeffrey S. Myers; G. Thomas Arnold; Steven E. Platnick; Liam E. Gumley; Si-Chee Tsay; Christopher C. Moeller; Michael Fitzgerald; Kenneth S. Brown; Fred G. Osterwisch

1996-08-01T23:59:59.000Z

45

Gas chromatograph-mass spectrometer (GC/MS) system for quantitative analysis of reactive chemical compounds  

DOE Patents (OSTI)

Described is a new gas chromatograph-mass spectrometer (GC/MS) system and method for quantitative analysis of reactive chemical compounds. All components of such a GC/MS system external to the oven of the gas chromatograph are programmably temperature controlled to operate at a volatilization temperature specific to the compound(s) sought to be separated and measured.

Grindstaff, Quirinus G. (Oak Ridge, TN)

1992-01-01T23:59:59.000Z

46

HD gas analysis with Gas Chromatography and Quadrupole Mass Spectrometer  

E-Print Network (OSTI)

A gas analyzer system has been developed to analyze Hydrogen-Deuteride (HD) gas for producing frozen-spin polarized HD targets, which are used for hadron photoproduction experiments at SPring-8. Small amounts of ortho-H$_{2}$ and para-D$_{2}$ gas mixtures ($\\sim$0.01%) in the purified HD gas are a key to realize a frozen-spin polarized target. In order to obtain reliable concentrations of these gas mixtures in the HD gas, we produced a new gas analyzer system combining two independent measurements with the gas chromatography and the QMS. The para-H$_{2}$, ortho-H$_{2}$, HD, and D$_{2}$ are separated using the retention time of the gas chromatography and the mass/charge. It is found that the new gas analyzer system can measure small concentrations of $\\sim$0.01% for the otho-H$_2$ and D$_2$ with good S/N ratios.

T. Ohta; S. Bouchigny; J. -P. Didelez; M. Fujiwara; K. Fukuda; H. Kohri; T. Kunimatsu; C. Morisaki; S. Ono; G. Rouille; M. Tanaka; K. Ueda; M. Uraki; M. Utsuro; S. Y. Wang; M. Yosoi

2011-01-28T23:59:59.000Z

47

A Novel 9.4 Tesla FT-ICR Mass Spectrometer with Improved Sensitivity, Mass Resolution, and Mass Range, for Petroleum Heavy Crude Oil Analysis  

E-Print Network (OSTI)

A Novel 9.4 Tesla FT-ICR Mass Spectrometer with Improved Sensitivity, Mass Resolution, and Mass advances in instrument speed and sensitivity. We have redesigned our custom built 9 4 tesla FT ICR New 9 = 800 000 [C32H55S1+H]+ [C35H51+H]+ We have redesigned our custom-built 9.4 tesla FT-ICR mass

Weston, Ken

48

Fire and biofuel contributions to annual mean aerosol mass concentrations in the United States  

E-Print Network (OSTI)

Fire and biofuel contributions to annual mean aerosol mass concentrations in the United States 1 2: Aerosols, Wildfires, Biomass burning, Biofuel, Air quality, Visibility Index terms: 1 #12;Abstract.1 2 3 4 burning (summer wildfires, other fires, residential biofuel, and industrial biofuel) to seasonal

Jacob, Daniel J.

49

Performance of a Focused Cavity Aerosol Spectrometer for Measurements in the Stratosphere of Particle Size in the 0.06–2.0-µm-Diameter Range  

Science Conference Proceedings (OSTI)

A focused cavity aerosol spectrometer aboard a NASA ER-2 high-altitude aircraft provided high-resolution measurements of the size of the stratospheric particles in the 0.06–2.0-µm-diameter range in flights following the eruption of Mount Pinatubo ...

H.H. Jonsson; J.C. Wilson; C.A. Brock; R.G. Knollenberg; T.R. Newton; J.E. Dye; D. Baumgardner; S. Borrmann; G.V. Ferry; R. Pueschel; Dave C. Woods; Mike C. Pitts

1995-02-01T23:59:59.000Z

50

Design of a Real-Time Scanning Electrical Mobility Spectrometer and its Application in Study of Nanoparticle Aerosol Generation  

E-Print Network (OSTI)

A real-time, mobile Scanning Electrical Mobility Spectrometer (SEMS) was designed using a Condensation Particle Counter (CPC) and Differential Mobility Analyzer (DMA) to measure the size distribution of nanoparticles. The SEMS was calibrated using monodisperse Polystyrene Latex (PSL) particles, and was then applied to study the size distribution of TiO2 nanoparticle aerosols generated by spray drying water suspensions of the nanoparticles. The nanoparticle aerosol size distribution, the effect of surfactant, and the effect of residual solvent droplets were determined. The SEMS system was designed by integrating the Electrical System, the Fluid Flow System, and the SEMS Software. It was calibrated using aerosolized Polystyrene Latex (PSL) spheres with nominal diameters of 99 nm and 204 nm. TiO2 nanoparticle aerosols were generated by atomizing water suspensions of TiO2 nanoparticles using a Collison nebulizer. Size distribution of the TiO2 aerosol was measured by the SEMS, as well as by TEM. Furthermore, the effect of surfactant, Tween 20 at four different concentrations between 0.01mM and 0.80mM, and stability of aerosol concentration with time were studied. It was hypothesized that residual particles in DI water observed during the calibration process were a mixture of impurities in water and unevaporated droplets. Solid impurities were captured on TEM grids using a point-to-plane Electrostatic Precipitator (ESP) and analyzed by Energy Dispersive Spectroscopy (EDS) while the contribution of unevaporated liquid droplets to residual particles was confirmed by size distribution measurements of aerosolized DI water in different humidity conditions. The calibration indicated that the mode diameter was found to be at 92.5nm by TEM and 95.8nm by the SEMS for 99nm nominal diameter particles, a difference of 3.6%. Similarly, the mode diameter for 204nm nominal diameter particles was found to be 194.9nm by TEM and 191nm by SEMS, a difference of 2.0%. Measurements by SEMS for TiO2 aerosol generated by Collison nebulizer indicated the mode diameters of 3mM, 6mM, and 9mM concentrations of TiO2 suspension to be 197.5nm, 200.0nm and 195.2nm respectively. On the other hand, the mode diameter was found to be approximately 95nm from TEM analysis of TiO2 powder. Additionally, concentration of particles generated decreased with time. Dynamic Light Scattering (DLS) measurements indicated agglomeration of particles in the suspension. Furthermore, the emulation of single particle distribution was not possible even after using Tween 20 in concentrations between 0.01mM and 0.80mM. From the study of residual particles in DI water, it was found that residual particles observed during the aerosolization of suspensions of DI water were composed of impurities present in DI water and unevaporated droplets of DI water. Although it was possible to observe solid residual particles on the TEM grid, EDS was not able to determine the chemical composition of these particles.

Singh, Gagan

2010-05-01T23:59:59.000Z

51

High mass resolution time of flight mass spectrometer for measuring products in heterogeneous catalysis in highly sensitive microreactors  

Science Conference Proceedings (OSTI)

We demonstrate a combined microreactor and time of flight system for testing and characterization of heterogeneous catalysts with high resolution mass spectrometry and high sensitivity. Catalyst testing is performed in silicon-based microreactors which have high sensitivity and fast thermal response. Gas analysis is performed with a time of flight mass spectrometer with a modified nude Bayard-Alpert ionization gauge as gas ionization source. The mass resolution of the time of flight mass spectrometer using the ion gauge as ionization source is estimated to m/{Delta}m > 2500. The system design is superior to conventional batch and flow reactors with accompanying product detection by quadrupole mass spectrometry or gas chromatography not only due to the high sensitivity, fast temperature response, high mass resolution, and fast acquisition time of mass spectra but it also allows wide mass range (0-5000 amu in the current configuration). As a demonstration of the system performance we present data from ammonia oxidation on a Pt thin film showing resolved spectra of OH and NH{sub 3}.

Andersen, T.; Jensen, R.; Christensen, M. K.; Chorkendorff, I. [Department of Physics, Danish National Research Foundation's Center for Individual Nanoparticle Functionality (CINF), Technical University of Denmark, Building 312, DK-2800 Kgs. Lyngby (Denmark); Pedersen, T.; Hansen, O. [Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech Building 345 East, DK-2800 Kgs. Lyngby (Denmark)

2012-07-15T23:59:59.000Z

52

Fractal morphology, imaging and mass spectrometry of single aerosol particles in flight  

DOE Data Explorer (OSTI)

This deposition includes the aerosol diffraction images used for phasing, fractal morphology, and time-of-flight mass spectrometry. Files in this deposition are ordered in subdirectories that reflect the specifics.

Loh, N. Duane

53

Elemental analysis of aerosol organic nitrates with electron ionization high-resolution mass spectrometry  

E-Print Network (OSTI)

Four hydroxynitrates (R(OH)R'ONO2) representative of atmospheric volatile organic compound (VOC) oxidation products were synthesized, nebulized and sampled into an Aerodyne High Resolution Time of Flight Aerosol Mass ...

Rollins, A. W.

54

Applications of High-Resolution Electrospray Ionization Mass Spectrometry to Measurements of Average Oxygen to Carbon Ratios in Secondary Organic Aerosols  

Science Conference Proceedings (OSTI)

The applicability of high resolution electrospray ionization mass spectrometry (HR ESI-MS) to measurements of the average oxygen to carbon ratio (O/C) in organic aerosols was investigated. Solutions with known average O/C containing up to 10 standard compounds representative of secondary organic aerosol (SOA) were analyzed and corresponding electrospray ionization efficiencies were quantified. The assumption of equal ionization efficiency commonly used in estimating O/C ratios of organic aerosols was found to be reasonably accurate. We found that the accuracy of the measured O/C ratios increases by averaging the values obtained from both (+) and (-) modes. A correlation was found between the ratio of the ionization efficiencies in the positive and negative ESI modes with the octanol-water partition constant, and more importantly, with the compound's O/C. To demonstrate the utility of this correlation for estimating average O/C values of unknown mixtures, we analyzed the ESI (+) and ESI (-) data for SOA produced by oxidation of limonene and isoprene and compared to online O/C measurements using an aerosol mass spectrometer (AMS). This work demonstrates that the accuracy of the HR ESI-MS methods is comparable to that of the AMS, with the added benefit of molecular identification of the aerosol constituents.

Bateman, Adam P.; Laskin, Julia; Laskin, Alexander; Nizkorodov, Sergey

2012-07-02T23:59:59.000Z

55

Elimination of ``memory`` from sample handling and inlet system of a mass spectrometer  

DOE Patents (OSTI)

This paper describes a method for preparing the sample handling and inlet system of a mass spectrometer for analysis of a subsequent sample following analysis of a previous sample comprising the flushing of the system interior with supercritical CO{sub 2} and venting the interior. The method eliminates the effect of system ``memory`` on the subsequent analysis, especially following persistent samples such as xenon and krypton.

Chastgner, P.

1991-05-08T23:59:59.000Z

56

Evolution of organic aerosol mass spectra upon heating: implications for OA phase and partitioning behavior  

Science Conference Proceedings (OSTI)

Vacuum Ultraviolet (VUV) photoionization mass spectrometry has been used to measure the evolution of chemical composition for two distinct organic aerosol types as they are passed through a thermodenuder at different temperatures. The two organic aerosol types considered are primary lubricating oil (LO) aerosol and secondary aerosol from the alpha-pinene + O3 reaction (alphaP). The evolution of the VUV mass spectra for the two aerosol types with temperature are observed to differ dramatically. For LO particles, the spectra exhibit distinct changes with temperature in which the lower m/z peaks, corresponding to compounds with higher vapor pressures, disappear more rapidly than the high m/z peaks. In contrast, the alphaP aerosol spectrum is essentially unchanged by temperature even though the particles experience significant mass loss due to evaporation. The variations in the LO spectra are found to be quantitatively in agreement with expectations from absorptive partitioning theory whereas the alphaP spectra suggest that the evaporation of alphaP derived aerosol appears to not be governed by partitioning theory. We postulate that this difference arises from the alphaP particles existing as in a glassy state instead of having the expected liquid-like behavior. To reconcile these observations with decades of aerosol growth measurements, which indicate that OA formation is described by equilibrium partitioning, we present a conceptual model wherein the secondary OA is formed and then rapidly converted from an absorbing form to a non-absorbing form. The results suggest that although OA growth may be describable by equilibrium partitioning theory, the properties of organic aerosol once formed may differ significantly from the properties determined in the equilibrium framework.

UC Davis; Cappa, Christopher D.; Wilson, Kevin R.

2010-10-28T23:59:59.000Z

57

System for studying a sample of material using a heavy ion induced mass spectrometer source  

DOE Patents (OSTI)

A heavy ion generator is used with a plasma desorption mass spectrometer to provide an appropriate neutron flux in the direction of a fissionable material in order to desorb and ionize large molecules from the material for mass analysis. The heavy ion generator comprises a fissionable material having a high (n,f) reaction cross section. The heavy ion generator also comprises a pulsed neutron generator that is used to bombard the fissionable material with pulses of neutrons, thereby causing heavy ions to be emitted from the fissionable material. These heavy ions impinge on a material, thereby causing ions to desorb off that material. The ions desorbed off the material pass through a time-of-flight mass analyzer, wherein ions can be measured with masses greater than 25,000 amu. 3 figs.

Fries, D.P.; Browning, J.F.

1998-07-21T23:59:59.000Z

58

System for studying a sample of material using a heavy ion induced mass spectrometer source  

DOE Patents (OSTI)

A heavy ion generator is used with a plasma desorption mass spectrometer to provide an appropriate neutron flux in the direction of a fissionable material in order to desorb and ionize large molecules from the material for mass analysis. The heavy ion generator comprises a fissionable material having a high n,f reaction cross section. The heavy ion generator also comprises a pulsed neutron generator that is used to bombard the fissionable material with pulses of neutrons, thereby causing heavy ions to be emitted from the fissionable material. These heavy ions impinge on a material, thereby causing ions to desorb off that material. The ions desorbed off the material pass through a time-of-flight mass analyzer, wherein ions can be measured with masses greater than 25,000 amu.

Fries, David P. (St. Petersburg, FL); Browning, James F. (Palm Harbour, FL)

1998-01-01T23:59:59.000Z

59

Method for studying a sample of material using a heavy ion induced mass spectrometer source  

DOE Patents (OSTI)

A heavy ion generator is used with a plasma desorption mass spectrometer to provide an appropriate neutron flux in the direction of a fissionable material in order to desorb and ionize large molecules from the material for mass analysis. The heavy ion generator comprises a fissionable material having a high n,f reaction cross section. The heavy ion generator also comprises a pulsed neutron generator that is used to bombard the fissionable material with pulses of neutrons, thereby causing heavy ions to be emitted from the fissionable material. These heavy ions impinge on a material, thereby causing ions to desorb off that material. The ions desorbed off the material pass through a time-of-flight mass analyzer, wherein ions can be measured with masses greater than 25,000 amu.

Fries, David P. (St. Petersburg, FL); Browning, James F. (Palm Harbour, FL)

1999-01-01T23:59:59.000Z

60

Method for studying a sample of material using a heavy ion induced mass spectrometer source  

DOE Patents (OSTI)

A heavy ion generator is used with a plasma desorption mass spectrometer to provide an appropriate neutron flux in the direction of a fissionable material in order to desorb and ionize large molecules from the material for mass analysis. The heavy ion generator comprises a fissionable material having a high n,f reaction cross section. The heavy ion generator also comprises a pulsed neutron generator that is used to bombard the fissionable material with pulses of neutrons, thereby causing heavy ions to be emitted from the fissionable material. These heavy ions impinge on a material, thereby causing ions to desorb off that material. The ions desorbed off the material pass through a time-of-flight mass analyzer, wherein ions can be measured with masses greater than 25,000 amu. 3 figs.

Fries, D.P.; Browning, J.F.

1999-02-16T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol mass spectrometer" 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

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

Science Conference Proceedings (OSTI)

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

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

2011-02-01T23:59:59.000Z

62

Application of a trochoidal electron monochromator/mass spectrometer system to the study of environmental chemicals  

SciTech Connect

A trochoidal electron monochromator has been interfaced to a mass spectrometer to perform electron capture negative ion mass spectrometric (ECNIMS) analyses of environmentally relevant chemicals. The kinetic energy of the electron beam can be varied from 0.025 to 30 eV under computer control. No reagent gas is used to moderate the electron energies. An electron energy spread of +/- 0.1 to +/- 0.4 eV full width at half-maximum (fwhm) can readily be obtained at a transmitted current of 2 x 10(-6) A, improving to +/- 0.07 eV at 5 x 10(-7) A. Comparisons of ECNI results from the electron monochromator/mass spectrometer system with those from a standard instrument that uses a moderating gas show similar spectra for heptachlor but not for the s-triazine herbicides, as for example, atrazine. This compound shows numerous adduct ions by standard ECNIMS that are eliminated by using the electron monochromator to generate the mass spectra. Isomeric tetrachlorodibenzo-p-dioxins show distinct differences in the electron energies needed to produce the maximum amount of parent and fragment anions. Multiple resonance states resulting in stable radical anions (M.-) are easily observed for nitrobenzene and for polycyclic aromatic hydrocarbons. Ionic products of dissociative electron capture invariably occur from several resonance states.

Laramee, J.A.; Kocher, C.A.; Deinzer, M.L. (Oregon State Univ., Corvallis (United States))

1992-10-15T23:59:59.000Z

63

A new method of alpha ray measurement using a Quadrupole Mass Spectrometer  

E-Print Network (OSTI)

We propose a new method of alpha($\\alpha$)-ray measurement that detects helium atoms with a Quadrupole Mass Spectrometer(QMS). A demonstration is undertaken with a plastic-covered $^{241}$Am $\\alpha$-emitting source to detect $\\alpha$-rays stopped in the capsule. We successfully detect helium atoms that diffuse out of the capsule by accumulating them for one to 20 hours in a closed chamber. The detected amount is found to be proportional to the accumulation time. Our method is applicable to probe $\\alpha$-emitting radioactivity in bulk material.

Y. Iwata; Y. Inoue; M. Minowa

2007-04-16T23:59:59.000Z

64

MASS SPECTROMETRIC APPROACHES FOR CHEMICAL CHARACTERISATION OF ATMOSPHERIC AEROSOLS: CRITICAL REVIEW OF MOST RECENT ADVANCES  

Science Conference Proceedings (OSTI)

This manuscript presents an overview of the most recent instrument developments, field and laboratory applications of mass spectrometry (MS) in chemistry and physics of atmospheric aerosols. A broad range of MS instruments employing different sample introduction methods, ionization and mass detection techniques are utilized for both 'on-line' and 'off-line' characterization of aerosols. On-line MS techniques enable detection of individual particles with simultaneous measurements of particle size distributions and aerodynamic characteristics, and are ideally suited for field studies which require high temporal resolution. Off-line MS techniques provide means for detailed molecular-level analysis of aerosol samples which is essential to fundamental knowledge on aerosol chemistry, mechanisms of particle formation and atmospheric aging. Combined together, complementary MS techniques provide comprehensive information on the chemical composition, size, morphology and phase of aerosols - data of key importance for evaluating hygroscopic and optical properties of particles, their health effects, understanding their origins, and atmospheric evolution. Developments and applications of MS techniques in the aerosol research have expanded remarkably over a couple of last years as evidenced by sky-rocketing publication statistics. The goal of this review is to period of late 2010 - early 2012, which were not conveyed in previous reviews.

Laskin, Alexander; Laskin, Julia; Nizkorodov, Sergey

2012-06-29T23:59:59.000Z

65

Manifold and method of batch measurement of Hg-196 concentration using a mass spectrometer  

DOE Patents (OSTI)

A sample manifold and method of its use has been developed so that milligram quantities of mercury can be analyzed mass spectroscopically to determine the [sup 196]Hg concentration to less than 0.02 atomic percent. Using natural mercury as a standard, accuracy of [+-]0.002 atomic percent can be obtained. The mass spectrometer preferably used is a commercially available GC/MS manufactured by Hewlett Packard. A novel sample manifold is contained within an oven allowing flow rate control of Hg into the MS. Another part of the manifold connects to an auxiliary pumping system which facilitates rapid clean up of residual Hg in the manifold. Sample cycle time is about 1 hour. 8 figures.

Grossman, M.W.; Evans, R.

1991-11-26T23:59:59.000Z

66

Hybrid quadrupole mass filter/quadrupole ion trap/time-of-flight-mass spectrometer for infrared multiple photon dissociation spectroscopy of mass-selected ions  

Science Conference Proceedings (OSTI)

We present a laboratory-constructed mass spectrometer optimized for recording infrared multiple photon dissociation (IRMPD) spectra of mass-selected ions using a benchtop tunable infrared optical parametric oscillator/amplifier (OPO/A). The instrument is equipped with two ionization sources, an electrospray ionization source, as well as an electron ionization source for troubleshooting. This hybrid mass spectrometer is composed of a quadrupole mass filter for mass selection, a reduced pressure ({approx}10{sup -5} Torr) quadrupole ion trap (QIT) for OPO irradiation, and a reflectron time-of-flight drift tube for detecting the remaining precursor and photofragment ions. A helium gas pulse is introduced into the QIT to temporarily increase the pressure and hence enhance the trapping efficiency of axially injected ions. After a brief pump-down delay, the compact ion cloud is subjected to the focused output from the continuous wave OPO. In a recent study, we implemented this setup in the study of protonated tryptophan, TrpH{sup +}, as well as collision-induced dissociation products of this protonated amino acid [W. K. Mino, Jr., K. Gulyuz, D. Wang, C. N. Stedwell, and N. C. Polfer, J. Phys. Chem. Lett. 2, 299 (2011)]. Here, we give a more detailed account on the figures of merit of such IRMPD experiments. The appreciable photodissociation yields in these measurements demonstrate that IRMPD spectroscopy of covalently bound ions can be routinely carried out using benchtop OPO setups.

Gulyuz, Kerim; Stedwell, Corey N.; Wang Da; Polfer, Nick C. [Department of Chemistry, University of Florida, P.O. Box 117200, Gainesville, Florida 32611 (United States)

2011-05-15T23:59:59.000Z

67

Initial Assessment of the Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR)-Based Aerosol Retrieval: Sensitivity Study  

SciTech Connect

The Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR) being developed for airborne measurements will offer retrievals of aerosol microphysical and optical properties from multi-angular and multi-spectral measurements of sky radiance and direct-beam sun transmittance. In this study, we assess the expected accuracy of the 4STAR-based aerosol retrieval and its sensitivity to major sources of anticipated perturbations in the 4STAR measurements by adapting a theoretical approach previously developed for the AERONET measurements. The major anticipated perturbations are (1) an apparent enhancement of sky radiance at small scattering angles associated with the necessarily compact design of the 4STAR and (2) and an offset (i.e. uncertainty) of sky radiance calibration independent of scattering angle. The assessment is performed through application of the operational AERONET aerosol retrieval and constructed synthetic 4STAR-like data. Particular attention is given to the impact of these perturbations on the upwelling and downwelling broadband fluxes and the direct aerosol radiative forcing at the bottom and top of the atmosphere. The results from this study suggest that limitations in the accuracy of 4STAR-retrieved particle size distributions and scattering phase functions have diminished impact on the accuracy of retrieved bulk microphysical parameters, permitting quite accurate retrievals of properties including the effective radius (up to 10%, or 0.03), and the radiatively important optical properties, such as the asymmetry factor (up to 4%, or ±0.02) and single-scattering albedo (up to 6%, or ±0.04). Also, the obtained results indicate that the uncertainties in the retrieved aerosol optical properties are quite small in the context of the calculated fluxes and direct aerosol radiative forcing (up to 15%, or 3 Wm-2).

Kassianov, Evgueni I.; Flynn, Connor J.; Redemann, Jens; Schmid, Beat; Russell, P. B.; Sinyuk, Alexander

2012-10-24T23:59:59.000Z

68

Signal variation in single particle aerosol mass spectrometry  

E-Print Network (OSTI)

Rapid and accurate detection of airborne micro-particles is currently an important problem in national security. One approach to such detection, bioaerosol mass spectrometry (BAMS), is currently under development at Lawrence ...

Wissner-Gross, Zachary Daniel

2007-01-01T23:59:59.000Z

69

ARM - Field Campaign - Aerosol Life Cycle IOP at BNL  

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

govCampaignsAerosol Life Cycle IOP at BNL govCampaignsAerosol Life Cycle IOP at BNL Campaign Links Images Wiki 2011 ASR STM Presentation: Sedlacek 2011 ASR STM Presentation: Springston 2010 ASR Fall Meeting: Sedlacek News, June 14, 2011: Next-generation Aerosol-sampling Stations to Head for India Related Campaigns Aerosol Life Cycle: Chemical Ionization Mass Spectrometer - CIMS 2011.07.10, Lee, OSC Aerosol Life Cycle: HR-ToF-AMS 2011.06.15, Zhang, OSC Aerosol Life Cycle: ARM Mobile Facility 2 Aerosol Observing System 2011.06.15, Sedlacek, OSC Aerosol Life Cycle: UV-APS and Nano-SMPS 2011.06.10, Hallar, OSC Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Aerosol Life Cycle IOP at BNL 2011.06.01 - 2011.08.31 Lead Scientist : Arthur Sedlacek For data sets, see below.

70

Evolution of organic aerosol mass spectra upon heating: implications for OA phase and partitioning behavior  

E-Print Network (OSTI)

and Seinfeld, J. H. : Organic aerosol formation from theJ. : A large organic aerosol source in the free troposphereand Worsnop, D. R. : Organic aerosol components observed in

Cappa, Christopher D.

2011-01-01T23:59:59.000Z

71

Characterization of the Molecular Composition of Secondary Organic Aerosols using High Resolution Mass Spectrometry  

E-Print Network (OSTI)

in secondary organic aerosol formation from isoprene, Proc.biogenic secondary organic aerosol, J. Phys. Chem. A, 112(in secondary organic aerosol, Environ. Sci. Technol. , 41(

Sellon, Rachel Elizabeth

2012-01-01T23:59:59.000Z

72

Molecular Characterization of Nitrogen Containing Organic Compounds in Biomass Burning Aerosols Using High Resolution Mass Spectrometry  

DOE Green Energy (OSTI)

Although nitrogen-containing organic compounds (NOC) are important components of atmospheric aerosols, little is known about their chemical compositions. Here we present detailed characterization of the NOC constituents of biomass burning aerosol (BBA) samples using high resolution electrospray ionization mass spectrometry (ESI/MS). Accurate mass measurements combined with MS/MS fragmentation experiments of selected ions were used to assign molecular structures to individual NOC species. Our results indicate that N-heterocyclic alkaloid compounds - species naturally produced by plants and living organisms - comprise a substantial fraction of NOC in BBA samples collected from test burns of five biomass fuels. High abundance of alkaloids in test burns of ponderosa pine - a widespread tree in the western U.S. areas frequently affected by large scale fires - suggests that N-heterocyclic alkaloids in BBA can play a significant role in dry and wet deposition of fixed nitrogen in this region.

Laskin, Alexander; Smith, Jeffrey S.; Laskin, Julia

2009-05-13T23:59:59.000Z

73

Differential Mobility Spectrometry/Mass Spectrometry: The Design of a New Mass Spectrometer for Real-Time Chemical Analysis in the Field  

SciTech Connect

The design of a prototype, field-portable mass spectrometer (MS) is described. The MS has been designed with an atmospheric interface in order to couple the system to a commercially available differential mobility spectrometer. The differential mobility spectrometer provides selective injection of trace-level analytes of interest into the inlet of the MS for real-time chemical detection. To accomplish this task, the MS design incorporates the use of an electrodynamic ion funnel to transport the ion beam, generated at atmospheric pressure, to the high-vacuum chamber that houses the mass analyzer. This leads to a design that utilizes two stages of differential pumping to achieve an overall pressure drop from atmosphere (760 Torr) to approximately 1 ×

,

2010-08-01T23:59:59.000Z

74

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

Science Conference Proceedings (OSTI)

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

Glenn E. Shaw

1983-05-01T23:59:59.000Z

75

Study of gas evolution during oil shale pyrolysis by TQMS (triple quadrupole mass spectrometer)  

DOE Green Energy (OSTI)

Real-time gas evolution during pyrolysis of two Green River Formation (Colorado) oil shales, one eastern US Devonian shale, and two Chinese shales was monitored using a triple quadrupole mass spectrometer (TQMS). We calculated kinetic parameters for hydrocarbon generation. For water, carbon oxides, and sulfur gases, we compared evolution profiles and identified the organicinorganic precursors of each species. We also monitored nitrogen- and sulfur-containing naphtha components. Hydrocarbon gas profiles, except for CH/sub 4/, are similar for all shales, and their rates of evolution reach a maximum at around the temperatures of maximum oil evolutions. The evolution profiles for H/sub 2/, CH/sub 2/, CO, and CO/sub 2/, at high temperatures are affected by the amount of char remaining in shale, carbonate minerals, and the water-gas shift reaction. The water profile, in general, consists of waters from surface dehydration, kerogen pyrolysis, and mineral dehydration. Mineral dehydration was the dominant water source for all shales, but the temperature ranges for the major water peak varied because of widely different mineral composition. Chinese shales evolved much more water than U.S. shales. Major differences between shales were seen in the sulfur gases. 17 refs., 4 figs., 3 tabs.

Oh, M.S.; Coburn, T.T.; Crawford, R.W.; Burnham, A.K.

1988-02-01T23:59:59.000Z

76

Molecular Characterization of Biomass Burning Aerosols Using High Resolution Mass Spectrometry  

DOE Green Energy (OSTI)

Chemical characterizations of atmospheric aerosols is a serious analytical challenge because of the complexity of particulate matter analyte composed of a large number of compounds with a wide range of molecular structures, physico-chemical properties, and reactivity. In this study chemical composition of biomass burning organic aerosol (BBOA) samples is characterized by high resolution electrospray ionization mass spectrometry (ESI/MS). Accurate mass measurement combined with Kendrick analysis allowed us to assign elemental composition for hundreds of compounds in the range of m/z values of 50-1000. ESI/MS spectra of different BBOA samples contain a variety of distinct, sample specific, characteristic peaks that can be used as unique markers for different types of biofuels. Our results indicate that a significant number of high-MW organic compounds in BBOA samples are highly oxidized polar species that can be efficiently detected using ESI/MS but are difficult to observe using the conventional GCMS analysis of aerosol samples. The average O:C ratios obtained for each of the BBOA samples studied in this work are in a strikingly good agreement with the previously reported values obtained using STXM/NEXAFS. The degree of unsaturation of detected organic compounds shows a clear decrease with increase in the molecular weight of the anyalyte molecules. The decrease is particularly pronounced for the samples containing a large number of CH2-based homologous series.

Smith, Jeffrey S.; Laskin, Alexander; Laskin, Julia

2009-02-13T23:59:59.000Z

77

Chemical Reaction of Cobalt Clusters with Ethanol by Using FT-ICR Mass Spectrometer  

E-Print Network (OSTI)

Spectrometer Shuhei Inoue*3 and Shigeo Maruyama*4 *3 Dept. of Mech. Sys. Eng., Hiroshima Univ., 1-4-1 Kagamiyama, Higashi-Hiroshima-shi, Hiroshima, 739-8527, Japan *4 Dept. of Mech. Eng., The Univ. of Tokyo, 7

Maruyama, Shigeo

78

Aerosols in Polluted versus Nonpolluted Air Masses: Long-Range Transport and Effects on Clouds  

Science Conference Proceedings (OSTI)

To assess the influence of anthropogenic aerosols on the physics and chemistry of clouds in the northeastern United State, aerosol and cloud-drop size distributions, elemental composition of aerosols as a function of size, and ionic content of ...

R. F. Pueschel; C. C. Van Valin; R. C. Castillo; J. A. Kadlecek; E. Ganor

1986-12-01T23:59:59.000Z

79

Facilities: NHMFL 14.5 Tesla Fourier Transform Ion Cyclotron Resonance Mass Spectrometer Citation: A Pseudoatomic Model of the COPII Cage Obtained from Cryo-Electron Microscopy and Mass Spectrometry,  

E-Print Network (OSTI)

Facilities: NHMFL 14.5 Tesla Fourier Transform Ion Cyclotron Resonance Mass Spectrometer Citation ultrahigh-resolution 14.5 tesla Fourier transform ion cyclotron resonance mass spectrometry. The Mag

Weston, Ken

80

Development of a variable-temperature ion mobility/ time-of-flight mass spectrometer for separation of electronic isomers  

E-Print Network (OSTI)

The construction of a liquid nitrogen-cooled ion mobility spectrometer coupled with time-of-flight mass spectrometry was implemented to demonstrate the ability to discriminate between electronic isomers. Ion mobility allows for the separation of ions based on differing cross-sections-to-charge ratio. This allows for the possible discrimination of species with same mass if the ions differ by cross-section. Time-offlight mass spectrometry was added to mass identify the separated peak for proper identification. A liquid nitrogen-cooled mobility cell was employed for a two-fold purpose. First, the low temperatures increase the peak resolution to aid in resolving the separated ions. This is necessary when isomers may have similar cross-sections. Second, low temperature shortens the mean free path and decreases the neutral buffer gas speeds allowing for more interactions between the ions and the drift gas. Kr2+ study was performed to verify instrument performance. The variable-temperature ion mobility spectrometer was utilized to separate the distonic and conventional ion forms of CH3OH, CH3F, and CH3NH2 and to discriminate between the keto and enol forms of the acetone radical cation. Density functional theory and ab initio calculations were employed to aid in proper identification of separating isomers. Monte Carlo integration tools were also developed to predict ion cross-section and resolution within a buffer gas.

Verbeck, Guido Fridolin

2006-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol mass spectrometer" 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

Feasibility of the detection of trace elements in particulate matter using online High-Resolution Aerosol Mass Spectrometry  

SciTech Connect

The feasibility of using an online thermal-desorption electron-ionization high-resolution aerosol mass spectrometer (AMS) for the detection of particulate trace elements was investigated analyzing data from Mexico City obtained during the MILAGRO 2006 field campaign, where relatively high concentrations of trace elements have been reported. This potential application is of interest due to the real-time data provided by the AMS, its high sensitivity and time resolution, and the widespread availability and use of this instrument. High resolution mass spectral analysis, isotopic ratios, and ratios of different ions containing the same elements are used to constrain the chemical identity of the measured ions. The detection of Cu, Zn, As, Se, Sn, and Sb is reported. There was no convincing evidence for the detection of other trace elements commonly reported in PM. The elements detected tend to be those with lower melting and boiling points, as expected given the use of a vaporizer at 600oC in this instrument. Operation of the AMS vaporizer at higher temperatures is likely to improve trace element detection. The detection limit is estimated at approximately 0.3 ng m-3 for 5-min of data averaging. Concentration time series obtained from the AMS data were compared to concentration records determined from offline analysis of particle samples from the same times and locations by ICP (PM2.5) and PIXE (PM1.1 and PM0.3). The degree of correlation and agreement between the three instruments (AMS, ICP, and PIXE) varied depending on the element. The AMS shows promise for real-time detection of some trace elements, although additional work including laboratory calibrations with different chemical forms of these elements are needed to further develop this technique and to understand the differences with the ambient data from the other techniques. The trace elements peaked in the morning as expected for primary sources, and the many detected plumes suggest the presence of multiple point sources, probably industrial, in Mexico City which are variable in time and space, in agreement with previous studies.

Salcedo, D.; Laskin, Alexander; Shutthanandan, V.; Jimenez, Jose L.

2012-08-10T23:59:59.000Z

82

The Multiplexed Chemical Kinetic Photoionization Mass Spectrometer: A New Approach To Isomer-resolved Chemical Kinetics  

E-Print Network (OSTI)

instruments applied to analysis of complex chemical mixturesrelies on chemical separation (by chromatography) into pureThe multiplexed chemical kinetic photoionization mass

Osborne, David L.

2009-01-01T23:59:59.000Z

83

Carbonaceous Aerosol Study Using Advanced Particle Instrumentation  

E-Print Network (OSTI)

and atmospheric organic aerosol formation. Envir. Sci.of secondary organic aerosol mass fraction, Atmos. Chem.composition of ambient aerosol particles. Environ. Sci.

Qi, Li

2010-01-01T23:59:59.000Z

84

Chemical ionization tandem mass spectrometer for the in situ measurement of methyl hydrogen peroxide  

SciTech Connect

A new approach for measuring gas-phase methyl hydrogen peroxide [(MHP) CH{sub 3}OOH] utilizing chemical ionization mass spectrometry is presented. Tandem mass spectrometry is used to avoid mass interferences that hindered previous attempts to measure atmospheric CH{sub 3}OOH with CF{sub 3}O{sup -} clustering chemistry. CH{sub 3}OOH has been successfully measured in situ using this technique during both airborne and ground-based campaigns. The accuracy and precision for the MHP measurement are a function of water vapor mixing ratio. Typical precision at 500 pptv MHP and 100 ppmv H{sub 2}O is {+-}80 pptv (2 sigma) for a 1 s integration period. The accuracy at 100 ppmv H{sub 2}O is estimated to be better than {+-}40%. Chemical ionization tandem mass spectrometry shows considerable promise for the determination of in situ atmospheric trace gas mixing ratios where isobaric compounds or mass interferences impede accurate measurements.

St Clair, Jason M.; McCabe, David C. [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125 (United States); Crounse, John D. [Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125 (United States); Steiner, Urs [Varian, Inc., Santa Clara, California 95051 (United States); Wennberg, Paul O. [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125 (United States); Division of Engineering and Applied Science, California Institute of Technology, Pasadena, California 91125 (United States)

2010-09-15T23:59:59.000Z

85

High-Resolution Electrospray Ionization Mass Spectrometry Analysis of Water- Soluble Organic Aerosols Collected with a Particle into Liquid Sampler  

DOE Green Energy (OSTI)

This work demonstrates the utility of a particle-into-liquid sampler (PILS) a technique traditionally used for identification of inorganic ions present in ambient or laboratory aerosols for the analysis of water soluble organic aerosol (OA) using high resolution electrospray ionization mass spectrometry (HR ESI-MS). Secondary organic aerosol (SOA) was produced from 0.5 ppm mixing ratios of limonene and ozone in a 5 m3 Teflon chamber. SOA was collected simultaneously using a traditional filter sampler and a PILS. The filter samples were later extracted with either water or acetonitrile, while the aqueous PILS samples were analyzed directly. In terms of peak intensities, types of detectable compounds, average O:C ratios, and organic mass to organic carbon ratios, the resulting high resolution mass spectra were essentially identical for the PILS and filter based samples. SOA compounds extracted from both filter/acetonitrile extraction and PILS/water extraction accounted for >95% of the total ion current in ESI mass spectra. This similarity was attributed to high solubility of limonene SOA in water. In contrast, significant differences in detected ions and peak abundances were observed for pine needle biomass burning organic aerosol (BBOA) collected with PILS and filter sampling. The water soluble fraction of BBOA is considerably smaller than for SOA, and a number of unique peaks were detectable only by the filter/acetonitrile method. The combination of PILS collection with HR-ESI-MS analysis offers a new approach for molecular analysis of the water-soluble organic fraction in biogenic SOA, aged photochemical smog, and BBOA.

Bateman, Adam P.; Nizkorodov, Serguei; Laskin, Julia; Laskin, Alexander

2010-10-01T23:59:59.000Z

86

In situ calibration of inductively coupled plasma-atomic emission and mass spectroscopy  

DOE Patents (OSTI)

A method and apparatus for in situ addition calibration of an inductively coupled plasma atomic emission spectrometer or mass spectrometer using a precision gas metering valve to introduce a volatile calibration gas of an element of interest directly into an aerosol particle stream. The present situ calibration technique is suitable for various remote, on-site sampling systems such as laser ablation or nebulization.

Braymen, Steven D. (Ames, IA)

1996-06-11T23:59:59.000Z

87

Measurement of reactive and condensable gas permeation using a mass spectrometer  

Science Conference Proceedings (OSTI)

Permeation of water vapor, oxygen, nitrogen, and carbon dioxide through polymer films is measured by the programed valving mass spectrometry (PVMS) method. The results are calibrated with a standard permeation rate for each gas to determine the detection sensitivity. The calibrated lower detection limits are 1.90x10{sup -7} g/m{sup 2} day for water vapor, 2.81x10{sup -2} cm{sup 3}/m{sup 2} day for oxygen, 2.15x10{sup -2} cm{sup 3}/m{sup 2} day for nitrogen, and 3.29x10{sup -2} cm{sup 3}/m{sup 2} day for carbon dioxide. The lower detection limits presented here for water vapor, nitrogen, and carbon dioxide are more than two orders of magnitude lower than the corresponding values offered by the NIST-traceable standard techniques. In addition, the PVMS water vapor lower detection limit meets the sensitivity requirement for detecting 'ultrabarrier' water vapor permeation rates, while the oxygen lower detection limit is higher than that offered by the standard technique. However, the results suggest a modified measurement protocol and/or system modifications to overcome this limitation. Effusivity through a flow orifice was also examined using the PVMS method for the above gases. The effusion results from the flow orifice, combined with the permeation results from polymer samples, provide insight into the factors that may influence gas detection sensitivities.

Zhang Xiaodong; Lewis, Jay S.; Parker, Charles B.; Glass, Jeffrey T.; Wolter, Scott D. [Pratt School of Engineering, Duke University, Durham, North Carolina 27708 (United States); RTI International, Research Triangle Park, North Carolina 27709 (United States); Pratt School of Engineering, Duke University, Durham, North Carolina 27708 (United States)

2008-09-15T23:59:59.000Z

88

High-efficiency cross-beam magnetic electron-impact source for improved miniature Mattauch-Herzog mass spectrometer performance  

Science Conference Proceedings (OSTI)

We describe a newly designed cross-beam magnetic electron-impact ion source (CBM-EI). We demonstrate its superiority in comparison with a conventional source (CB-EI) when used with a commercial miniature sector-field-type, non-scanning mass spectrometer featuring Mattauch-Herzog geometry (MH-MS) and a permanent sector-field magnet. This paper clearly shows the value of the CBM-EI for enhancing MH-MS sensitivity. Unlike secondary electron-multiplier type detectors, the pixelated detector (IonCCD Trade-Mark-Sign ) used in the commercial MH-MS has no gain. The MH-MS/IonCCD system is therefore challenged to compete with time-of-flight and quadrupole MS systems due to their higher ion transmissions and detector gains. Using the new CBM-EI, we demonstrate an instrument sensitivity increase of 20-fold to 100-fold relative to the CB-EI-equipped instrument. This remarkable signal increase by the simple addition of the magnet assembly arises from the magnet-induced gyromotion of the thermionic electrons, which vastly increases the effective path length of the electrons through the ionization region, and the collimated nature of the electron flux, which optimizes the ion transmission through the 100-{mu}m object slit of the MH-MS. Some or all of the realized sensitivity increase may be exchanged for an increase in resolution and/or mass range through the use of a narrower object slit, or for a reduction in ion-source pressure to limit quenching. The CBM-EI should facilitate development of a differentially pumped ion source to extend the lifetime of the filament, especially in otherwise intractable applications associated with oxidizing and corrosive samples.

Hadjar, O.; Fowler, W. K. [OI Analytical/CMS Field Products, 2148 Pelham Parkway, Bldg. 400, Pelham, Alabama 35124 (United States)

2012-06-15T23:59:59.000Z

89

Development and Characterization of a Thermodenuder for Aerosol Volatility Measurements  

SciTech Connect

This SBIR Phase I project addressed the critical need for improved characterization of carbonaceous aerosol species in the atmosphere. The proposed work focused on the development of a thermodenuder (TD) system capable of systematically measuring volatility profiles of primary and secondary organic aerosol species and providing insight into the effects of absorbing and nonabsorbing organic coatings on particle absorption properties. This work provided the fundamental framework for the generation of essential information needed for improved predictions of ambient aerosol loadings and radiative properties by atmospheric chemistry models. As part of this work, Aerodyne Research, Inc. (ARI) continued to develop and test, with the final objective of commercialization, an improved thermodenuder system that can be used in series with any aerosol instrument or suite of instruments (e.g., aerosol mass spectrometers-AMS, scanning mobility particle sizers-SMPS, photoacoustic absorption spectrometers-PAS, etc.) to obtain aerosol chemical, physical, and optical properties as a function of particle volatility. In particular, we provided the proof of concept for the direct coupling of our improved TD design with a full microphysical model to obtain volatility profiles for different organic aerosol components and to allow for meaningful comparisons between different TD-derived aerosol measurements. In a TD, particles are passed through a heated zone and a denuding (activated charcoal) zone to remove semi-volatile material. Changes in particle size, number concentration, optical absorption, and chemical composition are subsequently detected with aerosol instrumentation. The aerosol volatility profiles provided by the TD will strengthen organic aerosol emission inventories, provide further insight into secondary aerosol formation mechanisms, and provide an important measure of particle absorption (including brown carbon contributions and identification, and absorption enhancements due to coatings on soot particles). The successfully completed Phase I project included construction of a prototype design for the TD with detailed physical modeling, testing with laboratory and ambient aerosol particles, and the initiation of a detailed microphysical model of the aerosol particles passing through the TD to extract vapor pressure distributions. The objective of the microphysical model is to derive vapor pressure distributions (i.e. vapor pressure ranges, including single chemical compounds, mixtures of known compounds, and complex ‘real-world’ aerosols, such as SOA, and soot particles with absorbing and nonabsorbing coatings) from TD measurements of changes in particle size, mass, and chemical composition for known TD temperatures and flow rates (i.e. residence times). The proposed Phase II project was designed to optimize several TD systems for different instrument applications and to combine the hardware and modeling into a robust package for commercial sales.

Dr. Timothy Onasch

2009-09-09T23:59:59.000Z

90

Number, Mass and Volume Distributions of Mineral Aerosol and Soils of the Sahara  

Science Conference Proceedings (OSTI)

A direct method will be described to determine the complete mineral size distribution in aerosol (xylene-insoluble component) and soils (water-insoluble component) covering a size range from 0.01 up to 100 ?m and 1000 ?m radius, respectively, by ...

Guillaume A. d'Almeida; Lothar Schütz

1983-02-01T23:59:59.000Z

91

Development of A Cryogenic Drift Cell Spectrometer and Methods for Improving the Analytical Figures of Merit for Ion Mobility-Mass Spectrometry Analysis  

E-Print Network (OSTI)

A cryogenic (325-80 K) ion mobility-mass spectrometer was designed and constructed in order to improve the analytical figures-of-merit for the chemical analysis of small mass analytes using ion mobility-mass spectrometry. The instrument incorporates an electron ionization source, a quadrupole mass spectrometer, a uniform field drift cell spectrometer encased in a cryogenic envelope, and an orthogonal geometry time-of-flight mass spectrometer. The analytical benefits of low temperature ion mobility are discussed in terms of enhanced separation ability, ion selectivity and sensitivity. The distinction between resolving power and resolution for ion mobility is also discussed. Detailed experimental designs and rationales are provided for each instrument component. Tuning and calibration data and methods are also provided for the technique. Proof-of-concept experiments for an array of analytes including rare gases (argon, krypton, xenon), hydrocarbons (acetone, ethylene glycol, methanol), and halides (carbon tetrachloride) are provided in order to demonstrate the advantages and limitations of the instrument for obtaining analytically useful information. Trendline partitioning of small analyte ions based on chemical composition is demonstrated as a novel chemical analysis method. The utility of mobility-mass analysis for mass selected ions is also demonstrated, particularly for probing the ion chemistry which occurs in the drift tube for small mass ions. As a final demonstration of the separation abilities of the instrument, the electronic states of chromium and titanium (ground and excited) are separated with low temperature. The transition metal electronic state separations demonstrated here are at the highest resolution ever obtained for ion mobility methods. The electronic conformational mass isomers of methanol (conventional and distonic) are also partially separated at low temperature. Various drift gases (helium, neon, and argon) are explored for the methanol system in order to probe stronger ion-neutral interaction potentials and effectuate higher resolution separations of the two isomeric ions. Finally, two versatile ion source designs and a method for axially focusing ions at low pressure (1-10 torr) using electrostatic fields is presented along with some preliminary work on the ion sources.

May, Jody C.

2009-08-01T23:59:59.000Z

92

Characterization of submicron aerosols at a rural site in Pearl River Delta of China using an Aerodyne High-Resolution Aerosol Mass Spectrometer  

E-Print Network (OSTI)

The Pearl River Delta (PRD) region in South China is one of the most economically developed regions in China, but it is also noted for its severe air pollution due to industrial/metropolitan emissions. In order to continuously ...

Kroll, Jesse

93

Self-calibrating mass spectrometer. Project accomplishment summary for DOE Technology Transfer Initiative project 92-Y12P-055-B1  

DOE Green Energy (OSTI)

A mass spectrometer gas analyzer analyzes gas mixtures to determine the type and relative amounts of gases that compose the mixture. Cost of the instrument is usually determined by how sensitive the device is; the more sensitive the measurements, the higher the price. Critical to getting good results from a mass spectrometer gas analyzer is having the instrument calibrated. An uncalibrated instrument will do qualitative analysis, but not quantitative analysis. The purpose of this Cooperative Research and Development Agreement (CRADA) was to develop a way to calibrate a gas analyzer with minimal effort by the operator. Using technology originally developed for nuclear weapons applications, researchers from the Oak Ridge Y-12 Plant and from Vacuum Technology, Inc. (VTI), developed a calibration method that uses metal hydride (hydrogen that is in solid form). The entire sequence is controlled by computer software developed as part of the CRADA research. After calibration, unknown gas samples are introduced, and the resulting mass spectra are compared to reference spectra appropriately adjusted by the instrument response to the calibrating hydrogen pulse. Because the shifts of the mass spectra of a number of common gases can be predicted by the shifts in the hydrogen peak, hydrogen can be used to calibrate the instrument for a variety of gases. Through the pattern recognition ability of the computer software, the analyzer works not only for hydrogen, but for other gases as well.

NONE

1996-04-18T23:59:59.000Z

94

ARM - Measurement - Aerosol absorption  

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

absorption absorption ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Aerosol absorption The process in which radiation energy is retained by aerosols. Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments AOS : Aerosol Observing System CSPHOT : Cimel Sunphotometer IAP : In-situ Aerosol Profiles (Cessna Aerosol Flights) PSAP : Particle Soot Absorption Photometer PASS : Photoacoustic Soot Spectrometer External Instruments OMI : Ozone Monitoring Instrument

95

Mass yields of secondary organic aerosols from the oxidation of alpha-pinene and real plant emissions  

E-Print Network (OSTI)

Biogenic volatile organic compounds (VOCs) are a significant source of global secondary organic aerosol (SOA); however, quantifying their aerosol forming potential remains a challenge. This study presents smog chamber ...

Kroll, Jesse

96

Monolithic spectrometer  

DOE Patents (OSTI)

A monolithic spectrometer is disclosed for use in spectroscopy. The spectrometer is a single body of translucent material with positioned surfaces for the transmission, reflection and spectral analysis of light rays.

Rajic, Slobodan (Knoxville, TN); Egert, Charles M. (Oak Ridge, TN); Kahl, William K. (Knoxville, TN); Snyder, Jr., William B. (Knoxville, TN); Evans, III, Boyd M. (Oak Ridge, TN); Marlar, Troy A. (Knoxville, TN); Cunningham, Joseph P. (Oak Ridge, TN)

1998-01-01T23:59:59.000Z

97

Evolution of Asian aerosols during transpacific transport in INTEX-B  

Science Conference Proceedings (OSTI)

Measurements of aerosol composition were made with an Aerodyne High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) on board the NSF/NCAR C-130 aircraft as part of the Intercontinental Chemical Transport Experiment Phase B 5 (INTEX-B) field campaign over the Eastern Pacific Ocean. The HR-ToF-AMS measurements of non-refractory submicron aerosol mass are shown to compare well with other aerosol instrumentation in the INTEX-B field study. Two case studies are described for pollution layers transported across the Pacific from the Asian continent, intercepted 3–4 days and 7–10 days downwind of Asia, respectively. Aerosol chemistry is shown to 10 be a robust tracer for air masses originating in Asia, specifically the presence of sulfate dominated aerosol is a distinguishing feature of Asian pollution layers that have been transported to the Eastern Pacific. We examine the time scales of processing for sulfate and organic aerosol in the atmosphere and show that our observations confirm a conceptual model for transpacific transport from Asia proposed by Brock et al. (2004). 15 Our observations of both sulfate and organic aerosol in aged Asian pollution layers are consistent with fast formation near the Asian continent, followed by washout during lofting and subsequent transformation during transport across the Pacific. Our observations are the first atmospheric measurements to indicate that although secondary organic aerosol (SOA) formation from pollution happens on the timescale of one day, 20 the oxidation of organic aerosol continues at longer timescales in the atmosphere. Comparisons with chemical transport models of data from the entire campaign reveal an under-prediction of SOA mass in the MOZART model, but much smaller discrepancies with the GEOS-Chem model than found in previous studies over the Western Pacific. No evidence is found to support a previous hypothesis for significant secondary 25 organic aerosol formation in the free troposphere.

Dunlea, E. J.; DeCarlo, Peter; Aiken, Allison; Kimmel, Joel; Peltier, R. E.; Weber, R. J.; Tomlinson, Jason M.; Collins, Donald R.; Shinozuka, Yohei; McNaughton, C. S.; Howell, S. G.; Clarke, A. D.; Emmons, L.; Apel, Eric; Pfister, G. G.; van Donkelaar, A.; Martin, R. V.; Millet, D. B.; Heald, C. L.; Jimenez, J. L.

2009-10-01T23:59:59.000Z

98

Subarctic atmospheric aerosol composition: 2. Hygroscopic growth properties  

SciTech Connect

Sub-arctic aerosols were sampled during July 2007 at the Abisko Scientific Research Station Stordalen site in northern Sweden with an instrument setup consisting of a custom-built Hygroscopicity Tandem Differential Mobility Analyzer (HTDMA) connected in series to a single particle mass spectrometer. Aerosol chemical composition in the form of bipolar single particle mass spectra was determined as a function of hygroscopic growth both in situ and in real time. The HTDMA was deployed at a relative humidity of 82% and particles with a dry mobility diameter of 260 nm were selected. Aerosols from two distinct airmasses were analyzed during the sampling period. Sea salt aerosols were found to be the dominant particle group with the highest hygroscopicity. High intensities of sodium and related peaks in the mass spectra were identified as exclusive markers for large hygroscopic growth. Particles from biomass combustion were found to be the least hygroscopic aerosol category. Species normally considered soluble (e.g., sulfates and nitrates) were found in particles ranging from high to low hygroscopicity. Furthermore, the signal intensities of the peaks related to these species did not correlate with hygroscopicity.

Herich, Hanna; Kammermann, Lukas; Friedman, Beth; Gross, Deborah S.; Weingartner, E.; Lohmann, U.; Spichtinger, Peter; Gysel, Martin; Baltensperger, Urs; Cziczo, Daniel J.

2009-07-10T23:59:59.000Z

99

In situ calibration of inductively coupled plasma-atomic emission and mass spectroscopy  

DOE Patents (OSTI)

A method and apparatus are disclosed for in situ addition calibration of an inductively coupled plasma atomic emission spectrometer or mass spectrometer using a precision gas metering valve to introduce a volatile calibration gas of an element of interest directly into an aerosol particle stream. The present in situ calibration technique is suitable for various remote, on-site sampling systems such as laser ablation or nebulization. 5 figs.

Braymen, S.D.

1996-06-11T23:59:59.000Z

100

Multidimensional spectrometer  

DOE Patents (OSTI)

A multidimensional spectrometer for the infrared, visible, and ultraviolet regions of the electromagnetic spectrum, and a method for making multidimensional spectroscopic measurements in the infrared, visible, and ultraviolet regions of the electromagnetic spectrum. The multidimensional spectrometer facilitates measurements of inter- and intra-molecular interactions.

Zanni, Martin Thomas (Madison, WI); Damrauer, Niels H. (Boulder, CO)

2010-07-20T23:59:59.000Z

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


101

Atmospheric Aerosols  

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

Tom Kirchstetter with aerosol measurement instrument Atmospheric Aerosols Atmospheric aerosol research at LBNL seeks to understand the air quality and climate impacts of particles...

102

Overview of the Cumulus Humilis Aerosol Processing Study.  

Science Conference Proceedings (OSTI)

Aerosols influence climate directly by scattering and absorbing radiation and indirectly through their influence on cloud microphysical and dynamical properties. The Intergovernmental Panel on Climate Change (IPCC) concluded that the global radiative forcing due to aerosols is large and in general cools the planet. But the uncertainties in these estimates are also large due to our poor understanding of many of the important processes related to aerosols and clouds. To address this uncertainty an integrated strategy for addressing issues related to aerosols and aerosol processes was proposed. Using this conceptual framework, the Cumulus Humilis Aerosol Processing Study (CHAPS) is a stage 1 activity, that is, a detailed process study. The specific focus of CHAPS was to provide concurrent observations of the chemical composition of the activated [particles that are currently serving as cloud condensation nuclei (CCN)] and nonactivated aerosols, the scattering and extinction profiles, and detailed aerosol and droplet size spectra in the vicinity of Oklahoma City, Oklahoma, during June 2007. Numerous campaigns have examined aerosol properties downwind from large pollution sources, including the Megacity Initiative: Local and Global Research Observations (MILAGRO) campaign and the two of the three Aerosol Characterization Experiments, ACE-2 and ACE-Asia. Other studies conducted near cities have examined changes in both aerosols and clouds downwind of urban areas. For example wintertime stratiform clouds associated with the urban plumes of Denver, Colorado, and Kansas City, Missouri, have a larger number concentration and smaller median volume diameter of droplets than clouds that had not been affected by the urban plume. Likewise, a decrease in precipitation in polluted regions along the Front Range of the Rocky Mountains was discovered. In a modeling study, it was found that precipitation downwind of urban areas may be influenced by changes in aerosols as well as the convergence pattern caused by the city. Recently, the New England Air Quality Study (NEAQS), and the 2004 International Consortium for Atmospheric Research on Transport and Transformation, which were conducted during the summer of 2004, examined the transport of pollutants and aerosols eastward from New England over the Atlantic Ocean. The Texas Air Quality Study/Gulf of Mexico Atmospheric Composition and Climate Study (TexAQS/GoMACCS) also looked at relationships between clouds and aerosols in polluted conditions around Houston, Texas. In contrast to these recent studies near large or very dirty cities, CHAPS was conducted near a moderately sized city that is representative of a large number of cities around the United States. CHAPS was also one of the first times that a Aerodyne aerosol mass spectrometer was used in conjunction with a counterflow virtual impactor (CVI) inlet on an aircraft. The AMS provides information on the nonrefractory (i.e., materials that are chemically and physically unstable at high temperatures) composition of aerosols, while the CVI uses a counterflow relative to the main incoming airstream to exclude small droplets and nonactivated particles from the inlet, allowing only larger cloud droplets to enter the inlet. The combination of the CVI and AMS allow the examination of the chemical composition of the dried aerosol kernel from the cloud droplets. A key objective of the U.S. Department of Energy's (DOE)'s Atmospheric Sciences Program (ASP) is to improve the understanding of aerosol radiative effects on climate. This objective encompasses not only clear sky observations but also studies relating the effects of both aerosols on clouds and clouds on aerosols - in particular, how clouds affect the chemical and optical properties of aerosols. The latter was the science driver in the design of CHAPS. The measurement strategy for CHAPS was intended to provide measurements relevant to four questions associated with the aerosol radiative forcing issues of interest to the ASP: (1) How do the below-cloud and above-cloud aerosol optical and clou

Berg, L. K.; Berkowitz, C. M.; Ogren, J. A.; Hostetler, C. A.; Ferrare, R. A.; Dubey, M.; Andrews, E.; Coulter, R. L.; Hair, J. W.; Hubbe, J. M.Lee, Y. N.; Mazzoleni, C; Olfert, J; Springston, SR; Environmental Science Division; PNNL; NOAA Earth System Research Lab.; NASA Langley Research Center; LANL; BNL; Univ.of Alberta; Univ. of Colorado

2009-11-01T23:59:59.000Z

103

Aerodyne Develops an Aircraft-Deployable Precision Aerosol Analyzer | U.S.  

Office of Science (SC) Website

Aerodyne Develops an Aircraft-Deployable Precision Aerosol Aerodyne Develops an Aircraft-Deployable Precision Aerosol Analyzer Small Business Innovation Research (SBIR) and Small Business Technology Transfer (STTR) SBIR/STTR Home About Funding Opportunity Announcements (FOAs) Applicant and Awardee Resources Commercialization Assistance Other Resources Awards SBIR/STTR Highlights Reporting Fraud Contact Information Small Business Innovation Research and Small Business Technology Transfer U.S. Department of Energy SC-29/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-5707 F: (301) 903-5488 E: sbir-sttr@science.doe.gov More Information » January 2013 Aerodyne Develops an Aircraft-Deployable Precision Aerosol Analyzer Aerodyne Research Inc. develops an aerosol mass spectrometer (AMS) that fills a critical need for size-resolved, quantitative chemical composition

104

Precision mass measurements of very short-lived, neutron-rich Na isotopes using a radiofrequency spectrometer  

E-Print Network (OSTI)

Mass measurements of high precision have been performed on sodium isotopes out to $^{30}$Na using a new technique of radiofrequency excitation of ion trajectories in a homogeneous magnetic field. This method, especially suited to very short-lived nuclides, has allowed us to significantly reduce the uncertainty in mass of the most exotic Na isotopes: a relative error of 5\\audi was achieved for $^{28}$Na having a half-life of only 30.5 ms and 9\\audi for the weakly produced $^{30}$Na. Verifying and minimizing binding energy uncertainties in this region of the nuclear chart is important for clarification of a long standing problem concerning the strength of the $N~=~20$ magic shell closure. These results are the fruit of the commissioning of the new experimental program Mistral.

Lunney, M D; Doubre, H; Henry, S; Monsanglant, C; De Saint-Simon, M; Thibault, C; Toader, C F; Borcea, C; Bollen, G

2001-01-01T23:59:59.000Z

105

BNL | Aerosol Lifecycle IOP  

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

Program Program Aerosol Life Cycle IOP The primary objectives that make up the Aerosol Life Cycle IOP can be broken down into three categories: Scientific; Logistical; and GVAX preparation. Scientific Objectives The science goals are to conduct intensive aerosol observations in a region exposed to anthropogenic, biogenic, and marine emissions with atmospheric processing times depending on air mass trajectories and time of day. Take advantage of new instruments in the MAOS (e.g., SP2, HR-PTRMS, ACSM, Trace Gas Suite, PASS-3, Aethelometer, UHSAS). Within this broad umbrella are embedded three main foci: Aerosol light absorption: How does the aerosol mass absorption coefficient (absorption per unit mass of BC) vary with atmospheric processing? Do observations agree with a shell-core model?

106

Characterization of ambient aerosol composition and formation mechanisms and development of quantification methodologies utilizing ATOFMS  

E-Print Network (OSTI)

compounds in fine atmospheric aerosol at the Jungfraujoch,on the Quantification of Aerosol Time-of-Flight MassMass Concentrations from Aerosol Time-of-Flight Mass

Qin, Xueying

2007-01-01T23:59:59.000Z

107

ARM - Measurement - Aerosol concentration  

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

concentration concentration ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Aerosol concentration A measure of the amount of aerosol particles (e.g. number, mass, volume) per unit volume of air. Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments AOS : Aerosol Observing System CSPHOT : Cimel Sunphotometer CPC : Condensation Particle Counter IAP : In-situ Aerosol Profiles (Cessna Aerosol Flights) TDMA : Tandem Differential Mobility Analyzer

108

Spectrometer gun  

SciTech Connect

A hand-holdable, battery-operated, microprocessor-based spectrometer gun includes a low-power matrix display and sufficient memory to permit both real-time observation and extended analysis of detected radiation pulses. Universality of the incorporated signal processing circuitry permits operation with various detectors having differing pulse detection and sensitivity parameters.

Waechter, David A. (Los Alamos, NM); Wolf, Michael A. (Los Alamos, NM); Umbarger, C. John (Los Alamos, NM)

1985-01-01T23:59:59.000Z

109

Spectrometer gun  

DOE Patents (OSTI)

A hand-holdable, battery-operated, microprocessor-based spectrometer gun is described that includes a low-power matrix display and sufficient memory to permit both real-time observation and extended analysis of detected radiation pulses. Universality of the incorporated signal processing circuitry permits operation with various detectors having differing pulse detection and sensitivity parameters.

Waechter, D.A.; Wolf, M.A.; Umbarger, C.J.

1981-11-03T23:59:59.000Z

110

Atmospheric Aerosols  

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

measuring equipment Atmospheric Aerosols Atmospheric aerosol research at Berkeley Lab seeks to understand the air quality and climate impacts of particles in the atmosphere. On...

111

New approaches for the chemical and physical characterization of aerosols using a single particle mass spectrometry based technique  

E-Print Network (OSTI)

1-2% of the oil mass, however the calcium ion peak at m/z 40and elemental carbon (EC) peaks. The HDDV oil mass spectraoil mass spectra were characterized by an intense Ca + ion peak and

Spencer, Matthew Todd

2007-01-01T23:59:59.000Z

112

Measurements of Carbonaceous Aerosols using Semi-Continuous Thermal-Optical Method  

Science Conference Proceedings (OSTI)

Carbonaceous aerosols are major components in air pollution as a result of energy consumption, thus measurement of them is important to waste management. Increasing interest has been drawn to the identification, measurement, analysis, and modeling of carbon aerosols in the past decade. This book chapter will provide a review of current state-of-art techniques to determine carbonaceous aerosols in relation to air pollution and waste management. The chapter will be composed of four parts. The introduction will discuss why carbon aerosols including elemental carbon (EC), organic carbon (OC), and total carbon (TC=EC+OC) are important to energy consumption, air pollution, waste management, and global climate change. Key definitions will be introduced. Relevant terminologies will be provided. The second part will be a review of the current state-of the art measurement techniques that are used to determine carbon aerosols. Both on-line and off-line methods will be described. Comparisons of different techniques that provide the same physical quantity will be provided based on recent literature findings. Differences among the physical parameters determined by various techniques will be discussed. The third part will focus on data analysis and products obtained from carbon aerosol measurements. In addition to EC, OC, and TC, primary organic carbon (POC) and secondary organic carbon (SOC) are of interest to researchers to understand the source and sink of carbonaceous aerosols. Techniques used to determine POC and SOC, such as the EC tracer method and positive matrix factorization, will be described and their differences discussed. Examples will be provided showing field data comparison between the Sunset organic carbon and elemental carbon field analyzer and the Aerodyne aerosol mass spectrometer, both of which are widely used for on-line aerosol measurements. The last part will report new trends and summarize future research needs in carbon aerosol measurement. Emerging problems will be identified and research priorities will be recommended.

Yu, Xiao-Ying

2011-08-01T23:59:59.000Z

113

Jankovic Aerosol Characterization.ppt  

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

Characterization, Characterization, Aerosol Characterization, Interpretation, and Interpretation, and Application of Data Application of Data NSRC Symposium NSRC Symposium July 8, 2008 John Jankovic, CIH CIH Center for Nanophase Materials Sciences Center for Nanophase Materials Sciences Aerosol Characterization, Interpretation, and Aerosol Characterization, Interpretation, and Application of Data Application of Data Department of Energy (DOE) Nanoscale Science Research Centers (NSRC) developing Approach to Nanomaterial ES&H - The CNMS Approach * Establish Exposure Control Guideline (ECG) - Characterize Aerosol * Collect and interpret data * Assign Process to a Control Band Aerosol Particle Characterization * Size distribution (geometric mean and geometric standard deviation related to either mass, surface, or number)

114

Aerosol Characteristics and Radiative Impacts over the Arabian Sea during the Intermonsoon Season: Results from ARMEX Field Campaign  

Science Conference Proceedings (OSTI)

During the second phase of the Arabian Sea Monsoon Experiment (ARMEX-II), extensive measurements of spectral aerosol optical depth, mass concentration, and mass size distribution of ambient aerosols as well as mass concentration of aerosol black ...

K. Krishna Moorthy; S. Suresh Babu; S. K. Satheesh

2005-01-01T23:59:59.000Z

115

Atmospheric Aerosols Aging Involving Organic Compounds and Impacts on Particle Properties  

E-Print Network (OSTI)

In the first part of this dissertation, we study the aging of soot, a representative type of primary aerosols, in the presence of OH-initiated oxidation products of toluene. Monodisperse soot particles are introduced into an environmental chamber where toluene is oxidized by OH radicals. The variations in soot particle properties are simultaneously monitored, including particle size, mass, organic mass faction, hygroscopicity, and optical properties. The changes in particle properties are found to be largely governed by the thickness of the organic coating that is closely related to reaction time and initial reactant concentrations. Derived from particle size and mass, the effective density increases while dynamic shape factor decreases as the organic coating grows, suggesting a compaction of the soot morphology. As the organic coating grows, the particles become more hygroscopic and have enhanced light scattering and absorption. The second part discusses the potential reactions between amines and some aerosol constituents and alteration of aerosol properties. The reactions between alkylamines and ammonium sulfate/bisulfate have been studied using a low-pressure fast flow reactor coupled to a mass spectrometer at 293 K. Alkylamines react with ammonium sulfate/bisulfate to form alkylaminium sulfates, suggesting the existence of alkylaminium salts in particle phase. We have extended our study to characterize the physicochemical properties of alkylaminium sulfates. The hygroscopicity, thermostability, and density of five representative alkylaminium sulfates have been measured by an integrated aerosol analytical system. All alkylaminium sulfate aerosols show monotonic size growth when exposed to increasing relative humidity. Mixing ammonium sulfate with alkylaminium sulfates lowers the deliquescence point corresponding to ammonium sulfate. Alkylaminium sulfates are thermally comparable to or more stable than ammonium sulfate. The densities of alkylaminium sulfate particles are lower than that of ammonium sulfate. Our results suggest that the organic compounds can effectively alter the composition and properties of atmospheric aerosols, considerably influencing the impacts of aerosols on air quality, climate forcing, and human health.

Qiu, Chong

2013-05-01T23:59:59.000Z

116

Real-Time Measurements of Engine-Out Trace Elements: Application of a Novel Soot Particle Aerosol Mass Spectrometer for Emissions Characterization  

E-Print Network (OSTI)

Lubricant-derived trace element emissions are the largest contributors to the accumulation of incombustible ash in diesel particulate filters (DPF), eventually leading to filter plugging and an increase in engine fuel ...

Cross, Eben Spencer

117

Catalytic Steam Reforming of Gasifier Tars: On-Line Monitoring of Tars with a Transportable Molecular-Beam Mass Spectrometer; Milestone Completion Report  

DOE Green Energy (OSTI)

A method for evaluating catalytic tar decomposition in real time is presented. The effectiveness of two catalysts are compared. A key technical and economic barrier to commercialization of biomass gasification technologies is the removal of tars that are unavoidably formed in this thermochemical process. Tars contain fuel value; however, they are problematic in gas engines (both reciprocating and turbine) because they condense in the fuel delivery system, forming deposits that negatively affect operation and efficiency. These tars also combust with high luminosity, potentially forming soot particles. The conventional technology for tar removal is wet scrubbing. Although this approach has shown some success, there are significant equipment and operating costs associated with it. In order to prevent the generation of toxic wastewater, the tars must be separated and either disposed as hazardous waste or, preferably, combusted in the gasification plant. A conceptually better approach is catalytic steam reforming of the tars to hydrogen and carbon monoxide (CO), effectively increasing the gasification efficiency and eliminating the problems mentioned above. In FY2000, Battelle Columbus Laboratories attempted to demonstrate integrated gasification-gas turbine operation using catalytic steam reforming of tars. NREL participated in those tests using the transportable molecular-beam mass spectrometer (TMBMS) to monitor the catalytic reactor's performance on-line [10]. Unfortunately, the pilot plant tests encountered operational problems that prevented conclusive determination of the efficacy of the selected catalyst (Battelle's DN34). In FY2001, NREL performed on-site tar steam reforming tests using a slip-stream of hot pyrolysis gas from the Thermochemical Process Development Unit (TCPDU), which was directed to a bench-scale fluidized bed reactor system designed expressly for this purpose. Supporting this effort, the TMBMS was employed to provide on-line analysis of the tar conversion. The gas composition changes were monitored by two identical gas chromatographs (GCs), and modified method 5 sampling was performed to obtain gravimetric conversion data. The combination of these analytical techniques provided definitive catalyst performance data, as well as linkage to previous and on-going work elsewhere. Two catalysts were tested: nickel (Ni) on potassium promoted alumina (Sued-Chemie C11-NK), used commercially for naphtha steam reforming, and alumina (Battelle's DN34) claimed to be effective for gasifier tar decomposition. In addition, sand was tested as an inert reference material.

Carpenter, D.; Ratcliff, M.; Dayton, D.

2002-05-01T23:59:59.000Z

118

Giga-Dalton Mass Spectrometry  

Current techniques to study large bio?molecules using mass spectrometer require fragmentation for the mass?to?charge ratios to be within the working range of the mass spectrometer. Analysis of the data is complex and often requires simulation ...

119

Organic Aerosol Partition Module Documentation  

Science Conference Proceedings (OSTI)

With the promulgation of new National Ambient Air Quality Standards (NAAQS) for fine particulate matter (PM-2.5), data and analytical tools are needed to support their implementation. This report documents an EPRI modeling component for efficiently simulating aspects of organic aerosol formation. Without this component, simulations would tend to overestimate the contribution of power plant emissions to atmospheric aerosol mass.

1999-07-14T23:59:59.000Z

120

Aerosol Observing System (AOS) Handbook  

Science Conference Proceedings (OSTI)

The Aerosol Observing System (AOS) is a suite of in situ surface measurements of aerosol optical and cloud-forming properties. The instruments measure aerosol properties that influence the earth’s radiative balance. The primary optical measurements are those of the aerosol scattering and absorption coefficients as a function of particle size and radiation wavelength and cloud condensation nuclei (CCN) measurements as a function of percent supersaturation. Additional measurements include those of the particle number concentration and scattering hygroscopic growth. Aerosol optical measurements are useful for calculating parameters used in radiative forcing calculations such as the aerosol single-scattering albedo, asymmetry parameter, mass scattering efficiency, and hygroscopic growth. CCN measurements are important in cloud microphysical models to predict droplet formation.

Jefferson, A

2011-01-17T23:59:59.000Z

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


121

Spectral Signatures of Polar Stratospheric Clouds and Sulfate Aerosol  

Science Conference Proceedings (OSTI)

Multiwavelength observations of Antarctic and midlatitude aerosol by the Cryogenic Limb Array Etalon Spectrometer (CLAES) experiment on the Upper Atmosphere Research Satellite are used to demonstrate a technique that identifies the location of ...

S. T. Massie; P. L. Bailey; J. C. Gille; E. C. Lee; J. L. Mergenthaler; A. E. Roche; J. B. Kumer; E. F. Fishbein; J. W. Waters; W. A. Lahoz

1994-10-01T23:59:59.000Z

122

Spatial and Temporal Variability of Aerosol Particles in Arctic Spring  

SciTech Connect

The objective of this work is to investigate the variability in the particle number concentration that may affect climate change assessment for Arctic regions. The Indirect and Semi-Direct Aerosol Campaign (ISDAC) was conducted in April 2008, in the vicinities of Fairbanks and Barrow, Alaska. Measurements of particle number concentrations and size distributions were conducted using a Passive Cavity Aerosol Spectrometer Probe (PCASP-100X) mounted under the Convair-580 aircraft wing. Total number concentration of particles (Na) with diameters in the range 0.12-3 ?m was determined for polluted and clean air masses during times when the air was free of clouds and/or precipitation. Variability in Na was considered for both vertical profiles and constant altitude (horizontal) flight legs. This variability can have important implications for estimates of particle properties used in global climate model (GCM) simulations. When aerosol particle layers were encountered, Na rapidly increased from 25 cm-3 up to 550 cm-3 within relatively clean air masses, and reached up to 2200 cm-3 within polluted air masses, dominated by biomass burning pollution. When averaging Na over different distance scales, it was found that Na=140 cm-3 represent an average value for the majority of the encountered clean cases; while Na=720 cm-3 is a mean for polluted cases dominated by biomass burning plumes. These estimates, however, would not capture the details of particle layers encountered during most of the flights. Average aerosol particle characteristics can be difficult to interpret, especially during polluted cases, due to small-scale spatial and temporal variability.

Shantz, Nicole C.; Gultepe, Ismail; Liu, Peter; Earle, Michael; Zelenyuk, Alla

2012-10-01T23:59:59.000Z

123

Real-time chemical analysis of aerosol particles  

Science Conference Proceedings (OSTI)

An important aspect of environmental atmospheric monitoring requires the characterization of airborne microparticles and aerosols. Unfortunately, traditional sample collection and handling techniques are prone to contamination and interference effects that can render an analysis invalid. These problems can be avoided by using real-time atmospheric sampling techniques followed by immediate mass spectrometric analysis. The former is achieved in these experiments via a two state differential pumping scheme that is attached directly to a commercially available quadruple ion trap mass spectrometer. Particles produced by an external particle generator enter the apparatus and immediately pass through two cw laser/fiberoptic based detectors positioned two centimeters apart. Timing electronics measure the time between detection events, estimate the particles arrival in the center of the ion trap and control the firing of a YAG laser. Ions produced when the UV laser light ablates the particle`s surface are stored by the ion trap for mass analysis. Ion trap mass spectrometers have several advantages over conventional time-of-flight instruments. First, they are capable of MS/MS analysis by the collisional dissociation of a stored species, This permits complete chemical characterization of airborne samples. Second, ion traps are small and lend themselves to portable, field oriented applications.

Yang, M.; Whitten, W.B.; Ramsey, J.M.

1995-04-01T23:59:59.000Z

124

Near real time vapor detection and enhancement using aerosol adsorption  

DOE Patents (OSTI)

A vapor sample detection method where the vapor sample contains vapor and ambient air and surrounding natural background particles. The vapor sample detection method includes the steps of generating a supply of aerosol that have a particular effective median particle size, mixing the aerosol with the vapor sample forming aerosol and adsorbed vapor suspended in an air stream, impacting the suspended aerosol and adsorbed vapor upon a reflecting element, alternatively directing infrared light to the impacted aerosol and adsorbed vapor, detecting and analyzing the alternatively directed infrared light in essentially real time using a spectrometer and a microcomputer and identifying the vapor sample.

Novick, Vincent J.; Johnson, Stanley A.

1997-12-01T23:59:59.000Z

125

ARM - Evaluation Product - Organic Aerosol Component VAP  

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

ProductsOrganic Aerosol Component VAP ProductsOrganic Aerosol Component VAP Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Evaluation Product : Organic Aerosol Component VAP 2011.01.08 - 2012.03.24 Site(s) SGP General Description Organic aerosol (OA, i.e., the organic fraction of particles) accounts for 10-90% of the fine aerosol mass globally and is a key determinant of aerosol radiative forcing. But atmospheric OA is poorly characterized and its life cycle insufficiently represented in models. As a result, current models are unable to simulate OA concentrations and properties. This deficiency represents a large source of uncertainty in the quantification of aerosol direct and indirect effects and the prediction of future climate change. The Organic Aerosol Component (OACOMP) value-added product (VAP) uses

126

ARM - Measurement - Aerosol optical depth  

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

depth depth ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Aerosol optical depth A measure of how much light aerosols prevent from passing through a column of atmosphere. Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments HSRL : High Spectral Resolution Lidar MPL : Micropulse Lidar MFRSR : Multifilter Rotating Shadowband Radiometer NIMFR : Normal Incidence Multifilter Radiometer Field Campaign Instruments AOS-PMFOV : Acoustical Optical Spectrometer-Photometer with Multiple

127

ARM - Measurement - Aerosol optical properties  

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

properties properties ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Aerosol optical properties The optical properties of aerosols, including asymmetry factor, phase-function, single-scattering albedo, refractive index, and backscatter fraction. Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments CSPHOT : Cimel Sunphotometer NEPHELOMETER : Nephelometer Field Campaign Instruments AOS-PMFOV : Acoustical Optical Spectrometer-Photometer with Multiple

128

The Segregation of Aerosols by Cloud-Nucleating Activity. Part I: Design, Construction, and Testing of A High-Flux Thermal Diffusion Cloud Chamber for Mass Separation  

Science Conference Proceedings (OSTI)

We describe a thermal diffusion cloud chamber operated in series with an aerodynamic dichotomous separator that can segregate aerosol particles by their abilities to nucleate cloud droplets. The apparatus takes advantage of compensating gradients ...

Lee Harrison; Halstead Harrison

1985-04-01T23:59:59.000Z

129

Evolution of the Pinatubo Aerosol: Raman Lidar Observations of Particle Optical Depth, Effective Radius, Mass, and Surface Area over Central Europe at 53.4°N  

Science Conference Proceedings (OSTI)

The Raman lidar technique has been applied to document the evolution and dissipation of the Pinatubo aerosol between 1991 and 1995. For the first time, profiles of the particle extinction coefficient have been determined with lidar in the ...

A. Ansmann; I. Mattis; U. Wandinger; F. Wagner; J. Reichardt; T. Deshler

1997-11-01T23:59:59.000Z

130

ARM - Measurement - Aerosol extinction  

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

CSPHOT : Cimel Sunphotometer CLDAEROSMICRO : Cloud and Aerosol Microphysical Properties DRI-GND : Desert Research Institute Ground-Based Aerosol Instruments IAP : In-situ Aerosol...

131

In-situ determination of atmospheric aerosol composition as a function of hygroscopic growth  

Science Conference Proceedings (OSTI)

An in-situ measurement setup to determine the chemical composition of aerosols as a function of hygroscopicity is presented. This has been done by connecting a custom-built Hygroscopicity Tandem Differential Mobility Analyzer (HTDMA) and an Aerosol Time-of-Flight Mass Spectrometer (ATOFMS), commercially available from TSI (Model 3800). Single particle bipolar mass spectra from aerosols leaving the HTDMA could thus be obtained as a function of the hygroscopic growth factor. For these studies the HTDMA was set at a relative humidity of 82% and particles with a dry diameter of 260 nm were selected. The setup was first laboratory tested after which field experiments were performed. Two datasets were obtained during wintertime 2007 in Switzerland: the first in the urban Zurich environment and the other at the remote high alpine research station Jungfraujoch (JFJ). In Zurich several thousand mass spectra were obtained in less than two days of sampling due to a high aerosol loading. At the JFJ, due to low particle concentrations in free tropospheric airmasses, a longer sampling period was required. Both in Zurich and at the JFJ two different growth factor modes were observed. Results from these two locations show that most aerosol particles were a mixture of several compounds. A large contribution of organics and combustion species was found in the less hygroscopic growth mode for both locations. Non-combustion refractory material (e.g. metals, mineral dust, and fly ash) was also highly enhanced in the non-hygroscopic particles. Sulfate, normally considered highly soluble, was found to be a constituent in almost all particles independent of their hygroscopic growth factor.

Herich, Hanna; Kammermann, Lukas; Gysel, Martin; Weingartner, E.; Baltensperger, Urs; Lohmann, U.; Cziczo, Daniel J.

2008-08-30T23:59:59.000Z

132

Instrument Series: Mass Spectrometry SPLAT II  

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

Mass Spectrometry Mass Spectrometry SPLAT II SPLAT II is a one-of-a-kind single particle mass spectrometer that was designed, constructed, and deployed at EMSL to allow users to precisely characterize the physical and chemical properties of nanoparticles. SPLAT II yields quantitative information on particle physical and chemical properties in the laboratory or in the field-even aboard an aircraft. In the context of EMSL's integrated problem-solving environment, the unique capabilities of SPLAT II enable vital research across a range of scientific fields. Research Applications Fundamental science - characterizing the properties and behavior of matter on the nanoscale Atmospheric chemistry - understanding the processes that control atmospheric aerosol life cycle Climate change - uncovering and helping

133

Relating hygroscopicity and composition of organic aerosol particulate matter  

SciTech Connect

A hygroscopicity tandem differential mobility analyzer (HTDMA) was used to measure the water uptake (hygroscopicity) of secondary organic aerosol (SOA) formed during the chemical and photochemical oxidation of several organic precursors in a smog chamber. Electron ionization mass spectra of the non-refractory submicron aerosol were simultaneously determined with an aerosol mass spectrometer (AMS), and correlations between the two different signals were investigated. SOA hygroscopicity was found to strongly correlate with the relative abundance of the ion signal m/z 44 expressed as a fraction of total organic signal (f44). m/z 44 is due mostly to the ion fragment CO+2 for all types of SOA systems studied, and has been previously shown to strongly correlate with organic O/C for ambient and chamber OA. The analysis was also performed on ambient OA from two field experiments at the remote site Jungfraujoch, and the megacity Mexico City, where similar results were found. A simple empirical linear relation between the hygroscopicity of OA at subsaturated RH, as given by the hygroscopic growth factor (GF) or “*org” parameter, and f44 was determined and is given by *org=2.2×f44?0.13. This approximation can be further verified and refined as the database for AMS and HTDMA measurements is constantly being expanded around the world. The use of this approximation could introduce an important simplification in the parameterization of hygroscopicity of OA in atmospheric models, since 20 f44 is correlated with the photochemical age of an air mass.

Duplissy, J.; DeCarlo, Peter F.; Dommen, J.; Alfarra, M. R.; Metzger, A.; Barmpadimos, I.; Prevot, A. S. H.; Weingartner, E.; Tritscher, Torsten; Gysel, Martin; Aiken, Allison; Jimenez, J. L.; Canagaratna, M. R.; Worsnop, Douglas R.; Collins, Donald R.; Tomlinson, Jason M.; Baltensperger, Urs

2011-02-10T23:59:59.000Z

134

Aerosol composition, chemistry, and source characterization during the 2008 VOCALS Experiment  

SciTech Connect

Chemical composition of fine aerosol particles over the northern Chilean coastal waters was determined onboard the U.S. DOE G-1 aircraft during the VOCALS (VAMOS Ocean-Cloud-Atmosphere-Land Study) field campaign between October 16 and November 15, 2008. SO42-, NO3-, NH4+, and total organics (Org) were determined using an Aerodyne Aerosol Mass Spectrometer, and SO42-, NO3-, NH4+, Na+, Cl-, CH3SO3-, Mg2+, Ca2+, and K+ were determined using a particle-into-liquid sampler-ion chromatography technique. The results show the marine boundary layer (MBL) aerosol mass was dominated by non- sea-salt SO42- followed by Na+, Cl-, Org, NO3-, and NH4+, in decreasing importance; CH3SO3-, Ca2+, and K+ rarely exceeded their respective limits of detection. The SO42- aerosols were strongly acidic as the equivalent NH4+ to SO42- ratio was only {approx}0.25 on average. NaCl particles, presumably of sea-salt origin, showed chloride deficits but retained Cl- typically more than half the equivalency of Na+, and are externally mixed with the acidic sulfate aerosols. Nitrate was observed only on sea-salt particles, consistent with adsorption of HNO3 on sea-salt aerosols, responsible for the Cl- deficit. Dust particles appeared to play a minor role, judging from the small volume differences between that derived from the observed mass concentrations and that calculated based on particle size distributions. Because SO42- concentrations were substantial ({approx}0.5 - {approx}3 {micro}g/m3) with a strong gradient (highest near the shore), and the ocean-emitted dimethylsulfide and its unique oxidation product, CH3SO3-, were very low (i.e., {le} 40 parts per trillion and <0.05 {micro}g/m3, respectively), the observed SO42- aerosols are believed to be primarily of terrestrial origin. Back trajectory calculations indicate sulfur emissions from smelters and power plants along coastal regions of Peru and Chile are the main sources of these SO4- aerosols. However, compared to observations, model calculations appeared to underestimate sulfate concentrations based on an existing emission inventory. The agreement between observations and model predictions of CO as well as total sulfur is reexamined in this work with a new emission inventory made available recently.

Lee, Y.; Springston, S.; Jayne, J.; Wang, J.; Senum, G.; Hubbe, J.; Alexander, L.; Brioude, J.; Spak, S.; Mena-Carrasco, M.; Kleinman, L.; Daum, P.

2010-03-15T23:59:59.000Z

135

HELIcal Orbit Spectrometer (HELIOS)  

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

kinematics The HELIOS Spectrometer concept The Argonne implementation of HELIOS Commissioning experiment Planned upgrades Helios elsewhere B.B.Back, Argonne National Laboratory...

136

Mobile Ice Nucleus Spectrometer  

SciTech Connect

This first year report presents results from a computational fluid dynamics (CFD) study to assess the flow and temperature profiles within the mobile ice nucleus spectrometer.

Kulkarni, Gourihar R.; Kok, G. L.

2012-05-07T23:59:59.000Z

137

SNS backscattering spectrometer, BASIS  

Science Conference Proceedings (OSTI)

We describe the design and current performance of the backscattering silicon spectrometer (BASIS), a time-of-flight backscattering spectrometer built at the spallation neutron source (SNS) of the Oak Ridge National Laboratory (ORNL). BASIS is the first silicon-based backscattering spectrometer installed at a spallation neutron source. In addition to high intensity, it offers a high-energy resolution of about 3.5 {mu}eV and a large and variable energy transfer range. These ensure an excellent overlap with the dynamic ranges accessible at other inelastic spectrometers at the SNS.

Mamontov, Eugene [ORNL; Herwig, Kenneth W [ORNL

2011-01-01T23:59:59.000Z

138

ARM - Measurement - Aerosol particle size distribution  

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

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

139

Single Particle Laser Mass Spectrometry Applied to Differential Ice Nucleation Experiments at the AIDA Chamber  

SciTech Connect

Experiments conducted at the Aerosol Interactions and Dynamics in the Atmosphere (AIDA) chamber located in Karlsruhe, Germany permit investigation of particle properties that affect the nucleation of ice at temperature and water vapor conditions relevant to cloud microphysics and climate issues. Ice clouds were generated by heterogeneous nucleation of Arizona test dust (ATD), illite, and hematite and homogeneous nucleation of sulfuric acid. Ice crystals formed in the chamber were inertially separated from unactivated, or ‘interstitial’ aerosol particles with a pumped counterflow virtual impactor (PCVI), then evaporated. The ice residue (i.e., the aerosol which initiated ice nucleation plus any material which was scavenged from the gas- and/or particle-phase), was chemically characterized at the single particle level using a laser ionization mass spectrometer. In this manner the species that first nucleated ice could be identified out of a mixed aerosol population in the chamber. Bare mineral dust particles were more effective ice nuclei (IN) than similar particles with a coating. Metallic particles from contamination in the chamber initiated ice nucleation before other species but there were few enough that they did not compromise the experiments. Nitrate, sulfate, and organics were often detected on particles and ice residue, evidently from scavenging of trace gas-phase species in the chamber. Hematite was a more effective ice nucleus than illite. Ice residue was frequently larger than unactivated test aerosol due to the formation of aggregates due to scavenging, condensation of contaminant gases, and the predominance of larger aerosol in nucleation.

Gallavardin, S. J.; Froyd, Karl D.; Lohmann, U.; Moehler, Ottmar; Murphy, Daniel M.; Cziczo, Dan

2008-08-26T23:59:59.000Z

140

Spatial and temporal variations of aerosols around Beijing in summer 2006: 2. Local and column aerosol optical properties  

SciTech Connect

Weather Research and Forecasting (WRF)-chem model calculations were conducted to study aerosol optical properties around Beijing, China, during the Campaign of Air Quality Research in Beijing and Surrounding Region 2006 (CAREBeijing-2006) period. In this paper, we interpret aerosol optical properties in terms of aerosol mass concentrations and their chemical compositions by linking model calculations with measurements. In general, model calculations reproduced observed features of spatial and temporal variations of various surface and column aerosol optical parameters in and around Beijing. Spatial and temporal variations of aerosol absorption, scattering, and extinction coefficient corresponded well to those of elemental carbon (primary aerosol), sulfate (secondary aerosol), and the total aerosol mass concentration, respectively. These results show that spatial and temporal variations of the absorption coefficient are controlled by local emissions (within 100 km around Beijing during the preceding 24 h), while those of the scattering coefficient are controlled by regional-scale emissions (within 500 km around Beijing during the preceding 3 days) under synoptic-scale meteorological conditions, as discussed in our previous study of aerosol mass concentration. Vertical profiles of aerosol extinction revealed that the contribution of secondary aerosols and their water uptake increased with altitude within the planetary boundary layer, leading to a considerable increase in column aerosol optical depth (AOD) around Beijing. These effects are the main factors causing differences in regional and temporal variations between particulate matter (PM) mass concentration at the surface and column AOD over a wide region in the northern part of the Great North China Plain.

Matsui, Hitoshi; Koike, Makoto; Kondo, Yutaka; Takegawa, Nobuyuki; Fast, Jerome D.; Poschl, U.; Garland, R. M.; Andreae, M. O.; Wiedensohler, A.; Sugimoto, N.; Zhu, T.

2010-11-23T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol mass spectrometer" 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

In-situ droplet monitoring for self-tuning spectrometers  

DOE Patents (OSTI)

A laser scattering based imaging technique is utilized in order to visualize the aerosol droplets in an inductively coupled plasma (ICP) torch from an aerosol source to the site of analytical measurements. The resulting snapshots provide key information about the spatial distribution of the aerosol introduced by direct and indirect injection devices: 1) a direct injection high efficiency nebulizer (DIHEN); 2) a large-bore DIHEN (LB-DIHEN); and 3) a PFA microflow nebulizer with a PFA Scott-type spray chamber. Moreover, particle image velocimetry (PIV) is used to study the in-situ behavior of the aerosol before interaction with, for example, plasma, while the individual surviving droplets are explored by particle tracking velocimetry (PTV). Further, the velocity distribution of the surviving droplets demonstrates the importance of the initial droplet velocities in complete desolvation of the aerosol for optimum analytical performance in ICP spectrometries. These new observations are important in the design of the next-generation direct injection devices for lower sample consumption, higher sensitivity, lower noise levels, suppressed matrix effects, and for developing smart spectrometers. For example, a controller can be provided to control the output of the aerosol source by controlling the configuration of the source or the gas flow rate via feedback information concerning the aerosol.

Montaser, Akbar (Potomac, MD); Jorabchi, Kaveh (Arlington, VA); Kahen, Kaveh (Kleinburg, CA)

2010-09-28T23:59:59.000Z

142

Aerosol composition, chemistry, and source characterization during the 2008 VOCALS Experiment  

Science Conference Proceedings (OSTI)

Chemical composition of fine aerosol particles over the northern Chilean coastal waters was determined onboard the U.S. DOE G-1 aircraft during the VOCALS (VAMOS Ocean-Cloud-Atmosphere-Land Study) field campaign between October 16 and November 15, 2008. SO42-, NO3-, NH4+, and total organics (Org) were determined using an Aerodyne Aerosol Mass Spectrometer, and SO42-, NO3-, NH4+, Na+, Cl-, CH3SO3-, Mg2+, Ca2+, and K+ were determined using a particle-into-liquid sampler-ion chromatography technique. The results show the marine boundary layer (MBL) aerosol mass was dominated by non- sea-salt SO42- followed by Na+, Cl-, Org, NO3-, and NH4+, in decreasing importance; CH3SO3-, Ca2+, and K+ rarely exceeded their respective limits of detection. The SO42- aerosols were strongly acidic as the equivalent NH4+ to SO42- ratio was only {approx}0.25 on average. NaCl particles, presumably of sea-salt origin, showed chloride deficits but retained Cl- typically more than half the equivalency of Na+, and are externally mixed with the acidic sulfate aerosols. Nitrate was observed only on sea-salt particles, consistent with adsorption of HNO3 on sea-salt aerosols, responsible for the Cl- deficit. Dust particles appeared to play a minor role, judging from the small volume differences between that derived from the observed mass concentrations and that calculated based on particle size distributions. Because SO42- concentrations were substantial ({approx}0.5 - {approx}3 {micro}g/m3) with a strong gradient (highest near the shore), and the ocean-emitted dimethylsulfide and its unique oxidation product, CH3SO3-, were very low (i.e., {le} 40 parts per trillion and Peru and Chile are the main sources of these SO4- aerosols. However, compared to observations, model calculations appeared to underestimate sulfate concentrations based on an existing emission inventory. The agreement between observations and model predictions of CO as well as total sulfur is reexamined in this work with a new emission inventory made available recently.

Lee, Y.; Springston, S.; Jayne, J.; Wang, J.; Senum, G.; Hubbe, J.; Alexander, L.; Brioude, J.; Spak, S.; Mena-Carrasco, M.; Kleinman, L.; Daum, P.

2010-03-15T23:59:59.000Z

143

Imaging Fourier transform spectrometer  

DOE Patents (OSTI)

This invention is comprised of an imaging Fourier transform spectrometer having a Fourier transform infrared spectrometer providing a series of images to a focal plane array camera. The focal plane array camera is clocked to a multiple of zero crossing occurrences as caused by a moving mirror of the Fourier transform infrared spectrometer and as detected by a laser detector such that the frame capture rate of the focal plane array camera corresponds to a multiple of the zero crossing rate of the Fourier transform infrared spectrometer. The images are transmitted to a computer for processing such that representations of the images as viewed in the light of an arbitrary spectral ``fingerprint`` pattern can be displayed on a monitor or otherwise stored and manipulated by the computer.

Bennett, C.L.

1993-09-13T23:59:59.000Z

144

Real time Faraday spectrometer  

DOE Patents (OSTI)

This invention is comprised of a charged particle spectrometer that contains a detection system which embodies the benefits of both foil-light emissions and faraday cups, yet it does not interfere with the particle beam. 5 Figs. (GHH)

Smith, T.E. Jr.; Struve, K.W.; Colella, N.J.

1990-12-31T23:59:59.000Z

145

An Instantaneous CCN Spectrometer  

Science Conference Proceedings (OSTI)

A thermal gradient diffusion cloud chamber with a supersaturation field that increases along the path of the flow of sample is used as a cloud condensation nucleus (CCN) spectrometer. The CCN spectrum is derived from the final droplet size ...

James G. Hudson

1989-12-01T23:59:59.000Z

146

Sandia National Laboratories Miniaturized Mass Spectrometer  

subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration. SAND # 2011-4872P TECHNOLOGY ...

147

Investigating the role of hydrogen in silicon deposition using an energy-resolved mass spectrometer and a Langmuir probe in an Ar/H{sub 2} radio frequency magnetron discharge  

SciTech Connect

The plasma parameters and ion energy distributions (IED) of the dominant species in an Ar-H{sub 2} discharge are investigated with an energy resolved mass spectrometer and a Langmuir probe. The plasmas are generated in a conventional magnetron chamber powered at 150 W, 13.56 MHz at hydrogen flow rates ranging from 0 to 25 sccm with a fixed argon gas flow rate of 15 sccm. Various H{sub n}{sup +}, SiH{sub n}{sup +}, SiH{sub n} fragments (with n = 1, 2, 3) together with Ar{sup +} and ArH{sup +} species are detected in the discharge. The most important species for the film deposition is SiH{sub n} (with n = 0, 1, 2). H fragments affect the hydrogen content in the material. The flux of Ar{sup +} decreases and the flux of ArH{sup +} increases when the hydrogen flow rate is increased; however, both fluxes saturate at hydrogen flow rates above 15 sccm. Electron density, n{sub e}, electron energy, T{sub e}, and ion density, n{sub i}, are estimated from the Langmuir probe data. T{sub e} is below 1.2 eV at hydrogen flow rates below 8 sccm, and about 2 eV at flow rates above 8 sccm. n{sub e} and n{sub i} decrease with increased hydrogen flow but the ratio of n{sub i} to n{sub e} increases. The formation of H{sup +} ions with energies above 36 eV and electrons with energies greater than 2 eV contributes to the decrease in hydrogen content at hydrogen flow rates above 8 sccm. Analysis of the IEDs indicates an inter-dependence of the species and their contribution to the thin film growth and properties.

Mensah, S. L.; Naseem, Hameed H. [University of Arkansas, Fayetteville, Arkansas 72701 (United States); Abu-Safe, Husam [Lebanese American University, Byblos (Lebanon); Gordon, M. H. [University of Denver, 2390 S. York St., Colorado 80208 (United States)

2012-07-15T23:59:59.000Z

148

Aerosol Can Failure  

Science Conference Proceedings (OSTI)

Presentation Title, Aerosol Can Failure ... Abstract Scope, A three-piece, welded seam aerosol can of liquid undercoating material failed catastrophically, ...

149

BNL | Aerosol Lifecycle Research  

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

identified strategic process-science foci: aerosol nucleation and growth and aerosol aging and mixing state. BNL is the lead laboratory responsible for the design and...

150

Impact of Future Climate and Emission Changes on Stratospheric Aerosols and Ozone  

Science Conference Proceedings (OSTI)

Global climatological distributions of key aerosol quantities (extinction, optical depth, mass, and surface area density) are shown in comparison with results from a three-dimensional global model including stratospheric and tropospheric aerosol ...

G. Pitari; E. Mancini; V. Rizi; D. T. Shindell

2002-02-01T23:59:59.000Z

151

Polarimetric Remote Sensing of Aerosols over Land  

Science Conference Proceedings (OSTI)

The sensitivity of accurate polarized reflectance measurements over a broad spectral (410 -2250 nm) and angular (±60° from nadir) range to the presence of aerosols over land is analyzed and the consequent ability to retrieve the aerosol burden and microphysical model is assessed. Here we present a new approach to the correction of polarization observations for the effects of the surface that uses longer wavelength observations to provide a direct estimate of the surface polarized reflectance. This approach to surface modeling is incorporated into an optimal estimation framework for retrieving the particle number density and a detailed aerosol microphysical model: effective radius, effective variance and complex refractive index of aerosols. A sensitivity analysis shows that the uncertainties in aerosol optical thickness (AOT) increase with AOT while the uncertainties in the microphysical model decrease. Of particular note is that the uncertainty in the single scattering albedo is less than 0.05 by the time the AOT is greater than 0.2. We also find that calibration is the major source of uncertainty and that perfect angular and spectral correlation of calibration errors reduces the uncertainties in retrieved quantities compared with the case of uncorrelated errors. Finally, in terms of required spectral range, we observe that shorter wavelength (aerosols from polarized reflectance observations. The optimal estimation scheme is then tested on observations made by the Research Scanning Polarimeter during the Aerosol Lidar Validation experiment and over Southern California wild fires. These two sets of observations test the retrieval scheme under pristine and polluted conditions respectively. In both cases we find that the retrievals are within the combined uncertainties of the retrieval and the Aerosol Robotic Network Cimel products and Total Ozone Mapping Spectrometer Aerosol Index that we are comparing to. This confirms the validity of the sensitivity analysis of the polarized reflectance observations to the aerosol number density and microphysical model and demonstrates the unique capability to accurately retrieve aerosol optical depths under pristine conditions and also the single scattering albedo of aerosols at higher optical depths.

Waquet, F.; Cairns, Brian; Knobelspiesse, Kirk D.; Chowdhary, J.; Travis, Larry D.; Schmid, Beat; Mishchenko, M.

2009-01-26T23:59:59.000Z

152

Broad band waveguide spectrometer  

DOE Patents (OSTI)

A spectrometer for analyzing a sample of material utilizing a broad band source of electromagnetic radiation and a detector. The spectrometer employs a waveguide possessing an entry and an exit for the electromagnetic radiation emanating from the source. The waveguide further includes a surface between the entry and exit portions which permits interaction between the electromagnetic radiation passing through the wave guide and a sample material. A tapered portion forms a part of the entry of the wave guide and couples the electromagnetic radiation emanating from the source to the waveguide. The electromagnetic radiation passing from the exit of the waveguide is captured and directed to a detector for analysis.

Goldman, Don S. (Folsom, CA)

1995-01-01T23:59:59.000Z

153

On The Importance of Organic Oxygen for Understanding Organic Aerosol  

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

On The Importance of Organic Oxygen for Understanding Organic Aerosol On The Importance of Organic Oxygen for Understanding Organic Aerosol Particles Title On The Importance of Organic Oxygen for Understanding Organic Aerosol Particles Publication Type Journal Article Year of Publication 2006 Authors Pang, Yanbo, B. J. Turpin, and Lara A. Gundel Journal Journal of Aerosol Science and Technology Volume 40 Start Page Chapter Pagination 128-133 Abstract This study shows how aerosol organic oxygen data could provide new and independent information about organic aerosol mass, aqueous solubility of organic aerosols, formation of secondary organic aerosol (SOA) and the relative contributions of anthropogenic and biogenic sources. For more than two decades atmospheric aerosol organic mass concentration has usually been estimated by multiplying the measured carbon content by an assumed organic mass (OM)-to-organic carbon (OC ) factor of 1.4. However, this factor can vary from 1.0 to 2.5 depending on location. This great uncertainty about aerosol organic mass limits our understanding of the influence of organic aerosol on climate, visibility and health.New examination of organic aerosol speciation data shows that the oxygen content is the key factor responsible for the observed range in the OM-to-OC factor. When organic oxygen content is excluded, the ratio of non-oxygen organic mass to carbon mass varies very little across different environments (1.12 to 1.14). The non-oxygen-OM-to-non-oxygen OC factor for all studied sites (urban and non-urban) is 1.13± 0.02. The uncertainty becomes an order of magnitude smaller than the uncertainty in the best current estimates of organic mass to organic carbon ratios (1.6± 0.2 for urban and 2.1± 0.2 for non-urban areas). When aerosol organic oxygen data become available, organic aerosol mass can be quite accurately estimated using just OC and organic oxygen (OO) without the need to know whether the aerosol is fresh or aged. In addition, aerosol organic oxygen data will aid prediction of water solubility since compounds with OO-to-OC higher than 0.4 have water solubilities higher than 1g per 100 g water

154

An Improved Raindrop Chemistry Spectrometer  

Science Conference Proceedings (OSTI)

A spectrometer allowing size-fractional chemical analysis of raindrops has been described previously by the authors. Modifications to this raindrop chemistry spectrometer now allow improved performance in windy conditions. Instrument ...

Stuart G. Bradley; Stephen J. Adams; C. David Stow; Stephen J. de Mora

1991-08-01T23:59:59.000Z

155

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

Science Conference Proceedings (OSTI)

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

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

1980-05-01T23:59:59.000Z

156

Solid aerosol generator  

DOE Patents (OSTI)

An improved solid aerosol generator used to produce a gas borne stream of dry, solid particles of predetermined size and concentration. The improved solid aerosol generator nebulizes a feed solution of known concentration with a flow of preheated gas and dries the resultant wet heated aerosol in a grounded, conical heating chamber, achieving high recovery and flow rates.

Prescott, Donald S. (Shelley, ID); Schober, Robert K. (Midwest City, OK); Beller, John (Idaho Falls, ID)

1992-01-01T23:59:59.000Z

157

Neutron range spectrometer  

DOE Patents (OSTI)

A neutron range spectrometer and method for determining the neutron energy spectrum of a neutron emitting source are disclosed. Neutrons from the source are colliminated along a collimation axis and a position sensitive neutron counter is disposed in the path of the collimated neutron beam. The counter determines positions along the collimation axis of interactions between the neutrons in the neutron beam and a neutron-absorbing material in the counter. From the interaction positions, a computer analyzes the data and determines the neutron energy spectrum of the neutron beam. The counter is preferably shielded and a suitable neutron-absorbing material is He-3. 1 fig.

Manglos, S.H.

1988-03-10T23:59:59.000Z

158

Importance of aerosol composition, mixing state, and morphology for heterogeneous ice nucleation: A combined field and laboratory approach  

E-Print Network (OSTI)

In this study chemical compositions of background aerosol and ice nuclei were examined through laboratory investigations using Raman spectroscopy and field measurements by single-particle mass spectrometry. Aerosol sampling ...

Baustian, Kelly J.

159

Quench anaylsis of MICE spectrometer superconducting solenoid  

SciTech Connect

MICE superconducting spectrometer solenoids fabrication and tests are in progress now. First tests of the Spectrometer Solenoid discovered some issues which could be related to the chosen passive quench protection system. Both solenoids do not have heaters and quench propagation relied on the 'quench back' effect, cold diodes, and shunt resistors. The solenoids have very large inductances and stored energy which is 100% dissipated in the cold mass during a quench. This makes their protection a challenging task. The paper presents the quench analysis of these solenoids based on 3D FEA solution of coupled transient electromagnetic and thermal problems. The simulations used the Vector Fields QUENCH code. It is shown that in some quench scenarios, the quench propagation is relatively slow and some areas can be overheated. They describe ways of improving the solenoids quench protection in order to reduce the risk of possible failure.

Kashikhin, Vladimir; Bross, Alan; /Fermilab; Prestemon, Soren; / /LBL, Berkeley

2011-09-01T23:59:59.000Z

160

Observations of Lower-Stratospheric CIONO2, HNO3, and Aerosol by the UARS CLAES Experiment between January 1992 and April 1993  

Science Conference Proceedings (OSTI)

This paper discusses simultaneous measurements of stratospheric CIONO2, HNO3, temperature, and aerosol extinction coefficient by the Cryogenic Limb Array Etalon Spectrometer (CLAES) on the NASA Upper Atmosphere Research Satellite (UARS), obtained ...

A. E. Roche; J. B. Kumer; J. L. Mergenthaler; R. W. Nightingale; W. G. Uplinger; G. A. Ely; J. F. Potter; D. J. Wuebbles; P. S. Connell; D. E. Kinnison

1994-10-01T23:59:59.000Z

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


161

Recent activities in the Aerosol Generation and Transport Program  

SciTech Connect

General statements may be made on the behavior of single-component and multi-component aerosols in the Nuclear Safety Pilot Plant vessel. The removal processes for U/sub 3/O/sub 8/, Fe/sub 2/O/sub 3/, and U/sub 3/O/sub 8/ + Fe/sub 2/O/sub 3/ aerosols are enhanced in a steam-air atmosphere. Steam-air seems to have little effect on removal of concrete aerosol from the vessel atmosphere. A steam-air environment causes a change in aerosol shape from chain-agglomerate to basically spherical for U/sub 3/O/sub 8/, Fe/sub 2/O/sub 3/, and U/sub 3/O/sub 8/ + Fe/sub 2/O/sub 3/ aerosol; for concrete the change in aerosol shape is from chain-agglomerate to partially spherical. The mass ratio of the individual components of a multi-component aerosol seems to have an observable influence on the resultant behavior of these aerosols in steam. The enhanced rate of removal of the U/sub 3/O/sub 8/, the Fe/sub 2/O/sub 3/, and the mixed U/sub 3/O/sub 8/ + Fe/sub 2/O/sub 3/ aerosols from the atmosphere of the NSPP vessel by steam-air is probably caused by the change in aerosol shape and the condensation of steam on the aerosol surfaces combining to increase the effect of gravitational settling. The apparent lack of an effect by steam-air on the removal rate of concrete aerosol could result from a differing physical/chemical response of the surfaces of this aerosol to condensing steam.

Adams, R.E.

1984-01-01T23:59:59.000Z

162

Organic Aerosol Component (OACOMP) Value-Added Product Report  

SciTech Connect

Significantly improved returns in their aerosol chemistry data can be achieved via the development of a value-added product (VAP) of deriving OA components, called Organic Aerosol Components (OACOMP). OACOMP is primarily based on multivariate analysis of the measured organic mass spectral matrix. The key outputs of OACOMP are the concentration time series and the mass spectra of OA factors that are associated with distinct sources, formation and evolution processes, and physicochemical properties.

Fast, J; Zhang, Q; Tilp, A; Shippert, T; Parworth, C; Mei, F

2013-08-23T23:59:59.000Z

163

A New Hypothesis for the Vertical Distribution of Atmospheric Aerosols  

E-Print Network (OSTI)

A simple model which can explain the observed vertical distribution and size spectrum of atmospheric aerosol has been proposed. The model is based on a new physical hypothesis for the vertical mass exchange between the troposphere and the stratosphere. The vertical mass excange takes place through a gravity wave feedback mechanism. There is a close agreement between the model predicted aerosol distribution and size spectrum and the observed distributions.

A. Mary Selvam; A. S. Ramachandra Murty; Bh. V. Ramanamurty

1999-12-05T23:59:59.000Z

164

MATRIX (Multiconfiguration Aerosol TRacker of mIXing state): an aerosol microphysical module for global atmospheric models  

SciTech Connect

A new aerosol microphysical module MATRIX, the Multiconfiguration Aerosol TRacker of mIXing state, and its application in the Goddard Institute for Space Studies (GISS) climate model (ModelE) are described. This module, which is based on the quadrature method of moments (QMOM), represents nucleation, condensation, coagulation, internal and external mixing, and cloud-drop activation and provides aerosol particle mass and number concentration and particle size information for up to 16 mixed-mode aerosol populations. Internal and external mixing among aerosol components sulfate, nitrate, ammonium, carbonaceous aerosols, dust and sea-salt particles are represented. The solubility of each aerosol population, which is explicitly calculated based on its soluble and insoluble components, enables calculation of the dependence of cloud drop activation on the microphysical characterization of multiple soluble aerosol populations. A detailed model description and results of box-model simulations of various aerosol population configurations are presented. The box model experiments demonstrate the dependence of cloud activating aerosol number concentration on the aerosol population configuration; comparisons to sectional models are quite favorable. MATRIX is incorporated into the GISS climate model and simulations are carried out primarily to assess its performance/efficiency for global-scale atmospheric model application. Simulation results were compared with aircraft and station measurements of aerosol mass and number concentration and particle size to assess the ability of the new method to yield data suitable for such comparison. The model accurately captures the observed size distributions in the Aitken and accumulation modes up to particle diameter 1 {micro}m, in which sulfate, nitrate, black and organic carbon are predominantly located; however the model underestimates coarse-mode number concentration and size, especially in the marine environment. This is more likely due to oversimplifications of the representation of sea salt emissions - sea salt emissions are only calculated for two size classes - than to inherent limitations of MATRIX.

Bauer,S.E.; Wright, D.L.; Koch, D.; Lewis, E.R.; McGraw, R.; Chang, L.-S.; Schwartz, S.E.; Ruedy, R.

2008-10-21T23:59:59.000Z

165

Physicochemical Characterization of Capstone Depleted Uranium Aerosols I: Uranium Concentration in Aerosols as a Function of Time and Particle Size  

SciTech Connect

During the Capstone Depleted Uranium (DU) Aerosol Study, aerosols containing depleted uranium were produced inside unventilated armored vehicles (i.e., Abrams tanks and Bradley Fighting Vehicles) by perforation with large-caliber DU penetrators. These aerosols were collected and characterized, and the data were subsequently used to assess human health risks to personnel exposed to DU aerosols. The DU content of each aerosol sample was first quantified by radioanalytical methods, and selected samples, primarily those from the cyclone separator grit chambers, were analyzed radiochemically. Deposition occurred inside the vehicles as particles settled on interior surfaces. Settling rates of uranium from the aerosols were evaluated using filter cassette samples that collected aerosol as total mass over eight sequential time intervals. A moving filter was used to collect aerosol samples over time particularly within the first minute after the shot. The results demonstrate that the peak uranium concentration in the aerosol occurred in the first 10 s, and the concentration decreased in the Abrams tank shots to about 50% within 1 min and to less than 2% 30 min after perforation. In the Bradley vehicle, the initial (and maximum) uranium concentration was lower than those observed in the Abrams tank and decreased more slowly. Uranium mass concentrations in the aerosols as a function of particle size were evaluated using samples collected in the cyclone samplers, which collected aerosol continuously for 2 h post perforation. The percentages of uranium mass in the cyclone separator stages from the Abrams tank tests ranged from 38% to 72% and, in most cases, varied with particle size, typically with less uranium associated with the smaller particle sizes. Results with the Bradley vehicle ranged from 18% to 29% and were not specifically correlated with particle size.

Parkhurst, MaryAnn; Cheng, Yung-Sung; Kenoyer, Judson L.; Traub, Richard J.

2009-03-01T23:59:59.000Z

166

Scavenging of Aerosol Particles by Precipitation  

Science Conference Proceedings (OSTI)

Airborne measurements have been made of aerosol particle size distributions (>0.01 ?m) in aged air masses, in the plumes from several coal power plants and a large Kraft paper mill, and in the emissions from a volcano, before and after rain or ...

Lawrence F. Radke; Peter V. Hobbs; Mark W. Eltgroth

1980-06-01T23:59:59.000Z

167

Aerosols and solar energy  

DOE Green Energy (OSTI)

A brief description is presented of the involvement of the Solar Energy Research Institute (SERI) in atmospheric research, including aerosol characterization and modeling. The use of both rigorous and simple models for radiation transport is described. Modeled broadband solar irradiance data are shown to illustrate the important influence that aerosols have on the energy available to solar systems and the economics of solar systems design. Standard aerosol measurement methods for solar applications are discussed along with the need for improved instrumentation and methods.

Bird, R. E.; Hulstrom, R. L.

1979-01-01T23:59:59.000Z

168

Carbonaceous Aerosols and Radiative...  

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

Aerosols and Radiative Effects Study Science Objective This field campaign is designed to increase scientific knowledge about the evolution of black carbon, primary organic...

169

Computational simulation of aerosol behaviour.  

E-Print Network (OSTI)

??In this thesis, computational methods have been developed for the simulation of aerosol dynamics and transport. Two different coupled aerosol-computational fluid dynamics (CFD) models are… (more)

Pyykönen, Jouni

2002-01-01T23:59:59.000Z

170

Aerosol Condensational Growth in Cloud Formation  

E-Print Network (OSTI)

A code for the quasi-stationary solution of the coupled heat and mass transport equations for aerosols in a finite volume was developed. Both mass and heat are conserved effectively in the volume, which results in a competitive aerosol condensation growth computational model. A further model that couples this competitive aerosol condensation growth computational model with computational fluid dynamics (CFD) software (ANSYS FLUENT) enables the simulation of the realistic atmospheric environment. One or more air parcels, where the aerosols reside, are placed in a very big volume in order to mimic the large atmospheric environment. Mass (water vapor) and heat transportat between the air parcels and the environment facilitates the growth and prevents the parcels from unrealistically overheating. The suppression of cloud condensation nuclei (CCN) growth by high number densities was quantified by our model study. Model study with organic particles (Lmalic acid and maleic acid) indicates that when these organic species and ammonium sulfate are internally mixed, the particles can grow much more than if they are separately associated with distinct particles. Moreover, by using more multiple air parcels, which are randomly assigned with different initial relative humidity values according to a power law distribution, we studied the effects of atmospheric stochastic RH distribution on the growth of CCN.

Geng, Jun

2010-08-01T23:59:59.000Z

171

On the Importance of Organic Oxygen for Understanding OrganicAerosol Particles  

SciTech Connect

This study shows how aerosol organic oxygen data could provide new information about organic aerosol mass, aqueous solubility of organic aerosols, formation of secondary organic aerosol (SOA) and the relative contributions of anthropogenic and biogenic sources. For more than two decades atmospheric aerosol organic mass (OM) concentration has been estimated by multiplying the measured carbon content by an assumed (OM)-to-organic carbon (OC) factor, usually 1.4. However, this factor can vary from 1.0 to 2.5 depending on location. This large uncertainty about aerosol organic mass limits our understanding of the influence of organic aerosol on climate, visibility and health. New examination of organic aerosol speciation data shows that the oxygen content is responsible for the observed range in the OM-to-OC factor. When organic oxygen content is excluded, the ratio of non-oxygen organic mass to carbon mass varies very little across different environments (1.12 to 1.14). The non-oxygen-OM-to-OC factor for all studied sites (urban and non-urban) averaged 1.13. The uncertainty becomes an order of magnitude smaller than the uncertainty in the best current estimates of organic mass to organic carbon ratios (1.6 {+-} 0.2 for urban and 2.1 {+-} 0.2 for non-urban areas). This analysis suggests that, when aerosol organic oxygen data become available, organic aerosol mass can be quite accurately estimated using just OC and organic oxygen (OO) without the need to know whether the aerosol is fresh or aged. In addition, aerosol organic oxygen data will aid prediction of water solubility since compounds with OO-to-OC higher than 0.4 have water solubilities higher than 1 g per 100 g water.

Pang, Y.; Turpin, B.J.; Gundel, L.A.

2005-04-01T23:59:59.000Z

172

Ganges valley aerosol experiment.  

Science Conference Proceedings (OSTI)

In June 2011, the Ganges Valley Aerosol Experiment (GVAX) began in the Ganges Valley region of India. The objective of this field campaign is to obtain measurements of clouds, precipitation, and complex aerosols to study their impact on cloud formation and monsoon activity in the region.

Kotamarthi, V.R.; Satheesh, S.K. (Environmental Science Division); (Indian Institute of Science, Bangalore, India)

2011-08-01T23:59:59.000Z

173

Evolution of Organic Aerosols in the Atmosphere.  

SciTech Connect

Organic aerosol (OA) particles affect climate forcing and human health, but their sources and evolution remain poorly characterized. We present a unifying model framework that describes the atmospheric evolution of OA and is constrained and motivated by new, high time resolution, experimental characterizations of their composition, volatility, and oxidation state. OA and OA-precursor gases evolve by becoming increasingly oxidized, less volatile, and more hygroscopic, leading to the formation of large amounts of oxygenated organic aerosol (OOA) mass that has comparable concentrations to sulfate aerosol over the Northern Hemisphere. Our new model framework captures the dynamic aging behavior observed in the atmosphere and the laboratory and can serve as a basis for improving parameterizations in regional and global models.

Jimenez, J. L.; Canagaratna, M. R.; Donahue, N. M.; Prevot, A. S. H.; Zhang, Qi; Kroll, Jesse H.; DeCarlo, Peter F.; Allan, James D.; Coe, H.; Ng, N. L.; Aiken, Allison; Docherty, Kenneth S.; Ulbrich, Ingrid M.; Grieshop, A. P.; Robinson, A. L.; Duplissy, J.; Smith, J. D.; Wilson, K. R.; Lanz, V. A.; Hueglin, C.; Sun, Y. L.; Tian, J.; Laaksonen, A.; Raatikainen, T.; Rautiainen, J.; Vaattovaara, P.; Ehn, M.; Kulmala, M.; Tomlinson, Jason M.; Collins, Donald R.; Cubison, Michael J.; Dunlea, E. J.; Huffman, John A.; Onasch, Timothy B.; Alfarra, M. R.; Williams, Paul I.; Bower, K.; Kondo, Yutaka; Schneider, J.; Drewnick, F.; Borrmann, S.; Weimer, S.; Demerjian, K.; Salcedo, D.; Cottrell, L.; Griffin, Robert; Takami, A.; Miyoshi, T.; Hatakeyama, S.; Shimono, A.; Sun, J. Y.; Zhang, Y. M.; Dzepina, K.; Kimmel, Joel; Sueper, D.; Jayne, J. T.; Herndon, Scott C.; Trimborn, Achim; Williams, L. R.; Wood, Ezra C.; Middlebrook, A. M.; Kolb, C. E.; Baltensperger, Urs; Worsnop, Douglas R.

2009-12-11T23:59:59.000Z

174

Spectrometer for Sky-Scanning Sun-Tracking Atmospheric Research (4STAR): Instrument Technology  

SciTech Connect

The Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR) combines airborne sun tracking and sky scanning with diffraction spectroscopy, to improve knowledge of atmospheric constituents and their links to air-pollution/climate. Direct beam hyper-spectral measurement of optical depth improves retrievals of gas constituents and determination of aerosol properties. Sky scanning enhances retrievals of aerosol type and size distribution. 4STAR measurements will tighten the closure between satellite and ground-based measurements. 4STAR incorporates a modular sun-tracking/ sky-scanning optical head with fiber optic signal transmission to rack mounted spectrometers, permitting miniaturization of the external optical head, and future detector evolution. Technical challenges include compact optical collector design, radiometric dynamic range and stability, and broad spectral coverage. Test results establishing the performance of the instrument against the full range of operational requirements are presented, along with calibration, engineering flight test, and scientific field campaign data and results.

Dunagan, Stephen; Johnson, Roy; Zavaleta, Jhony; Russell, P. B.; Schmid, Beat; Flynn, Connor J.; Redemann, Jens; Shinozuka, Yohei; Livingston, J.; Segal Rozenhaimer, Michal

2013-08-06T23:59:59.000Z

175

Linear electric field mass spectrometry  

DOE Patents (OSTI)

A mass spectrometer and methods for mass spectrometry are described. The apparatus is compact and of low weight and has a low power requirement, making it suitable for use on a space satellite and as a portable detector for the presence of substances. High mass resolution measurements are made by timing ions moving through a gridless cylindrically symmetric linear electric field. 8 figs.

McComas, D.J.; Nordholt, J.E.

1992-12-01T23:59:59.000Z

176

Linear electric field mass spectrometry  

DOE Patents (OSTI)

A mass spectrometer and methods for mass spectrometry. The apparatus is compact and of low weight and has a low power requirement, making it suitable for use on a space satellite and as a portable detector for the presence of substances. High mass resolution measurements are made by timing ions moving through a gridless cylindrically symmetric linear electric field.

McComas, David J. (Los Alamos, NM); Nordholt, Jane E. (Los Alamos, NM)

1992-01-01T23:59:59.000Z

177

Loading capacity of various filters for lithium fire generated aerosols  

Science Conference Proceedings (OSTI)

The lithium aerosol loading capacity of a prefilter, HEPA filters and a sand and gravel bed filter was determined. The test aerosol was characterized and was generated by burning lithium in an unlimited air atmosphere. Correlation to sodium aerosol loading capacities were made to relate existing data to lithium aerosol loadings under varying conditions. This work is being conducted in support of the fusion reactor safety program. The lithium aerosol was generated by burning lithium pools, up to 45 kgs, in a 340 m/sup 3/ low humidity air atmosphere to supply aerosol to recirculating filter test loops. The aerosol was sampled to determine particle size, mass concentrations and chemical species. The dew point and gas concentrations were monitored throughout the tests. Loop inlet aerosol mass concentrations ranged up to 5 gr/m/sup 3/. Chemical compounds analyzed to be present in the aerosol include Li/sub 2/O, LiOH, and Li/sub 2/CO/sub 3/. HEPA filters with and without separators and a prefilter and HEPA filter in series were loaded with 7.8 to 11.1 kg/m/sup 2/ of aerosol at a flow rate of 1.31 m/sec and 5 kPa pressure drop. The HEPA filter loading capacity was determined to be greater at a lower flow rate. The loading capacity increased from 0.4 to 2.8 kg by decreasing the flow rate from 1.31 to 0.26 m/sec for a pressure drop of 0.11 kPa due to aerosol buildup. The prefilter tested in series with a HEPA did not increase the total loading capacity significantly for the same total pressure drop. Separators in the HEPA had only minor effect on loading capacity. The sand and gravel bed filter loaded to 0.50 kg/m/sup 2/ at an aerosol flow rate of 0.069 m/sec and final pressure drop of 6.2 kPa. These loading capacities and their dependence on test variables are similar to those reported for sodium aerosols except for the lithium aerosol HEPA loading capacity dependence upon flow rate.

Jeppson, D.W.; Barreca, J.R.

1980-10-23T23:59:59.000Z

178

ARM: 10-minute Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm  

DOE Data Explorer (OSTI)

10-minute Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

Rob Newsom; John Goldsmith

179

ARM: 1-minute Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm  

DOE Data Explorer (OSTI)

1-minute Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

Chitra Sivaraman; Connor Flynn

180

ARM: 1-minute Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm  

SciTech Connect

1-minute Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

Chitra Sivaraman; Connor Flynn

2010-12-15T23:59:59.000Z

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


181

Radiative and climate impacts of absorbing aerosols  

E-Print Network (OSTI)

P.M. Forster (2004), The semi-direct aerosol effect: Impactof absorbing aerosols on marine stratocumulus. Q. J .2005), Global anthropogenic aerosol direct forcing derived

Zhu, Aihua

2010-01-01T23:59:59.000Z

182

Monodisperse aerosol generator  

DOE Patents (OSTI)

An aerosol generator is described which is capable of producing a monodisperse aerosol within narrow limits utilizing an aqueous solution capable of providing a high population of seed nuclei and an organic solution having a low vapor pressure. The two solutions are cold nebulized, mixed, vaporized, and cooled. During cooling, particles of the organic vapor condense onto the excess seed nuclei, and grow to a uniform particle size.

Ortiz, L.W.; Soderholm, S.C.

1988-09-19T23:59:59.000Z

183

RACORO aerosol data processing  

Science Conference Proceedings (OSTI)

The RACORO aerosol data (cloud condensation nuclei (CCN), condensation nuclei (CN) and aerosol size distributions) need further processing to be useful for model evaluation (e.g., GCM droplet nucleation parameterizations) and other investigations. These tasks include: (1) Identification and flagging of 'splash' contaminated Twin Otter aerosol data. (2) Calculation of actual supersaturation (SS) values in the two CCN columns flown on the Twin Otter. (3) Interpolation of CCN spectra from SGP and Twin Otter to 0.2% SS. (4) Process data for spatial variability studies. (5) Provide calculated light scattering from measured aerosol size distributions. Below we first briefly describe the measurements and then describe the results of several data processing tasks that which have been completed, paving the way for the scientific analyses for which the campaign was designed. The end result of this research will be several aerosol data sets which can be used to achieve some of the goals of the RACORO mission including the enhanced understanding of cloud-aerosol interactions and improved cloud simulations in climate models.

Elisabeth Andrews

2011-10-31T23:59:59.000Z

184

Wavelength Dependence of Aerosol Extinction Coefficient for Stratospheric Aerosols  

Science Conference Proceedings (OSTI)

A simple empirical formula for the wavelength dependence of the aerosol extinction coefficient is proposed. The relationship between the constants in the formula and the variable parameter in the aerosol size distribution is explicitly expressed. ...

Glenn K. Yue

1986-11-01T23:59:59.000Z

185

Aerosols in a Changing Atmosphere: From Detailed Aerosol Microphysics...  

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

Aerosols in a Changing Atmosphere: From Detailed Aerosol Microphysics to Policy Applications Speaker(s): Susanne Bauer Date: December 6, 2011 - 4:00pm Location: 90-4133 Seminar...

186

Spin Spectrometer at the ALS and APS  

E-Print Network (OSTI)

5 Spin Spectrometer at the ALS and APS-NIM/SRI07 Figure 3 Ancollected on Beamline 7 at the ALS is shown here. The photonSpin Spectrometer at the ALS and APS-NIM/SRI07 Spin

Tobin, James G; Lawrence Livermore National Laboratory; University of Missouri-Rolla; Boyd Technologies

2008-01-01T23:59:59.000Z

187

THE NCNR NEUTRON SPIN ECHO SPECTROMETER  

Science Conference Proceedings (OSTI)

... The NSE spectrometer, developed in partnership with Exxon Research and Engineering and the Forschungszentrum Jülich in Germany [3], is ...

2000-02-29T23:59:59.000Z

188

Aerosol–CCN Closure at a Semi-rural Site  

Science Conference Proceedings (OSTI)

aerosol size distributions and size-resolved aerosol compositions measured by ... Keywords Cloud condensation nuclei, closure study, organic aerosols, Köhler.

189

Formation mechanisms and quantification of organic nitrates in atmospheric aerosol  

E-Print Network (OSTI)

Atmospheric submicron aerosol . . . . . . . 2.3 Partitioningon SOA organic aerosol formation alkyl nitrate and secondaryPeroxy radical fate . . . . . . Aerosol . . . . . . . .

Rollins, Andrew Waite

2010-01-01T23:59:59.000Z

190

Climate implications of carbonaceous aerosols: An aerosol microphysical study using the GISS/MATRIX climate model  

E-Print Network (OSTI)

and R. Ruedy, Matrix (multiconfiguration aerosol tracker ofmixing state): An aerosol microphysical module for globalAn investigative review, Aerosol Sci. Technol. , Vol. 40,

Bauer, Susanne E.

2010-01-01T23:59:59.000Z

191

TAX: Backscattering Spectrometer at SNS | ORNL Neutron Sciences  

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

The Triple-Axis Spectrometer at HFIR Triple-Axis Spectrometer (HB-3) Triple-Axis Spectrometer (HB-3). HB-3 is a colossal flux thermal neutron three-axis spectrometer designed for...

192

Commissioning of the HELIOS spectrometer.  

Science Conference Proceedings (OSTI)

This paper describes the implementation and commissioning of a device based on a new concept for measurements of nuclear reactions in inverse kinematics. The HELIcal Orbit Spectrometer, HELIOS, was commissioned at Argonne National Laboratory by studying the {sup 28}Si(d,p){sup 29}Si reaction in inverse kinematics. This experiment served as a proof of principle for this previously untested concept, and was used to verify the response and performance characteristics of HELIOS.

Lighthall, J. C.; Back, B. B.; Baker, S. I.; Freeman, S. J.; Lee, H. Y.; Kay, B. P.; Marley, S. T.; Rehm, K. E.; Rohrer, J. E.; Schiffer, J. P.; Shetty, D. V.; Vann, A. W.; Winkelbauer, J. R.; Wuosmaa, A. H.; Physics; Western Michigan Univ.; Univ. of Manchester

2010-01-01T23:59:59.000Z

193

Linear electric field mass spectrometry  

DOE Patents (OSTI)

A mass spectrometer is described having a low weight and low power requirement, for use in space. It can be used to analyze the ionized particles in the region of the spacecraft on which it is mounted. High mass resolution measurements are made by timing ions moving through a gridless cylindrically sysmetric linear electric field.

McComas, D.J.; Nordholt, J.E.

1991-03-29T23:59:59.000Z

194

Aerodynamic size associations of natural radioactivity with ambient aerosols  

SciTech Connect

The aerodynamic size of /sup 214/Pb, /sup 212/Pb, /sup 210/Pb, /sup 7/Be, /sup 32/P, /sup 35/S (as SO/sub 4//sup 2 -/), and stable SO/sub 4//sup 2 -/ was measured using cascade impactors. The activity distribution of /sup 212/Pb and /sup 214/Pb, measured by alpha spectroscopy, was largely associated with aerosols smaller than 0.52 ..mu..m. Based on 46 measurements, the activity median aerodynamic diameter of /sup 212/Pb averaged 0.13 ..mu..m (sigma/sub g/ = 2.97), while /sup 214/Pb averaged 0.16 ..mu..m (sigma/sub g/ = 2.86). The larger median size of /sup 214/Pb was attributed to ..cap alpha..-recoil depletion of smaller aerosols following decay of aerosol-associated /sup 218/Po. Subsequent /sup 214/Pb condensation on all aerosols effectively enriches larger aerosols. /sup 212/Pb does not undergo this recoil-driven redistribution. Low-pressure impactor measurements indicated that the mass median aerodynamic diameter of SO/sub 4//sup 2 -/ was about three times larger than the activity median diameter /sup 212/Pb, reflecting differences in atmospheric residence times as well as the differences in surface area and volume distributions of the atmospheric aerosol. Cosmogenic radionuclides, especially /sup 7/Be, were associated with smaller aerosols than SO/sub 4//sup 2 -/ regardless of season, while /sup 210/Pb distributions in summer measurements were similar to sulfate but smaller in winter measurements. Even considering recoil following /sup 214/Po ..cap alpha..-decay, the avervage /sup 210/Pb labeled aerosol grows by about a factor of two during its atmospheric lifetime. The presence of 5 to 10% of the /sup 7/Be on aerosols greater than 1 ..mu..m was indicative of post-condensation growth, probably either in the upper atmosphere or after mixing into the boundary layer.

Bondietti, E.A.; Papastefanou, C.; Rangarajan, C.

1986-04-01T23:59:59.000Z

195

Highly stable aerosol generator  

DOE Patents (OSTI)

An improved compressed air nebulizer has been developed such that a uniform aerosol particle size and concentration may be produced over long time periods. This result is achieved by applying a vacuum pressure to the makeup assembly and by use of a vent tube between the atmosphere and the makeup solution. By applying appropriate vacuum pressures to the makeup solution container and by proper positioning of the vent tube, a constant level of aspirating solution may be maintained within the aspirating assembly with aspirating solution continuously replaced from the makeup solution supply. This device may also be adapted to have a plurality of aerosol generators and only one central makeup assembly.

DeFord, Henry S. (Kennewick, WA); Clark, Mark L. (Kennewick, WA)

1981-01-01T23:59:59.000Z

196

Highly stable aerosol generator  

DOE Patents (OSTI)

An improved compressed air nebulizer has been developed such that a uniform aerosol particle size and concentration may be produced over long time periods. This result is achieved by applying a vacuum pressure to the makeup assembly and by use of a vent tube between the atmosphere and the makeup solution. By applying appropriate vacuum pressures to the makeup solution container and by proper positioning of the vent tube, a constant level of aspirating solution may be maintained within the aspirating assembly with aspirating solution continuously replaced from the makeup solution supply. This device may also be adapted to have a plurality of aerosol generators and only one central makeup assembly. 2 figs.

DeFord, H.S.; Clark, M.L.

1981-11-03T23:59:59.000Z

197

BNL | Aerosol, Cloud, Precipitation Interactions  

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

Cloud-Aerosol-Precipitation Interactions Cloud-Aerosol-Precipitation Interactions Atmospheric aerosols exert important "indirect effects" on clouds and climate by serving as cloud condensation nuclei (CCN) and ice nuclei that affect cloud radiative and microphysical properties. For example, an increase in CCN increases the number concentration of droplets enhances cloud albedo, and suppresses precipitation that alters cloud coverage and lifetime. However, in the case of moist and strong convective clouds, increasing aerosols may increase precipitation and enhance storm development. Although aerosol-induced indirect effects on climate are believed to have a significant impact on global climate change, estimating their impact continues to be one of the most uncertain climate forcings.

198

Geometrical Optics of Dense Aerosols  

SciTech Connect

Assembling a free-standing, sharp-edged slab of homogeneous material that is much denser than gas, but much more rare ed than a solid, is an outstanding technological challenge. The solution may lie in focusing a dense aerosol to assume this geometry. However, whereas the geometrical optics of dilute aerosols is a well-developed fi eld, the dense aerosol limit is mostly unexplored. Yet controlling the geometrical optics of dense aerosols is necessary in preparing such a material slab. Focusing dense aerosols is shown here to be possible, but the nite particle density reduces the eff ective Stokes number of the flow, a critical result for controlled focusing. __________________________________________________

Hay, Michael J.; Valeo, Ernest J.; Fisch, Nathaniel J.

2013-04-24T23:59:59.000Z

199

Characterization of a New Lead Slowing Down Spectrometer  

Science Conference Proceedings (OSTI)

There is considerable interest in developing direct measurement methods to determine the plutonium content of spent nuclear fuel within a fuel assembly. One technique that may prove successful is lead slowing-down spectroscopy. Lead Slowing Down Spectroscopy (LSDS) has been used for decades to make cross-section measurements on relatively small isotopic samples of well know masses. For spent fuel assembly measurements, LSDS will be applied in reverse; unknown masses will be determined using well-know cross-sections. In the LSDS, a pulse of neutrons (on the order of 10-100 MeV) is injected into a large lead stack (~ 1m3). The neutrons quickly down-scatter but exhibit little spread in energy about the average, continually-decreasing neutron energy making for a strong correlation between the elapsed time from the initial pulse and the average energy of the neutron. By measuring this elapsed time, it is possible to measure interactions of the neutrons with the fuel in the 0.1 to 1,000 eV range. Many of the actinides have strong resonances in this region, making it possible, through careful measurements and analysis, to extract isotopic masses from LSDS measurements. Pacific Northwest National Laboratory is actively conducting research on both LSDS measurement and data analysis techniques. This paper will present results of the effort to construct and characterize a new lead slowing down spectrometer. The spectrometer was designed to begin testing both experimental measurement and data analysis techniques for determining the plutonium content of spent fuel. To characterize the spectrometer, a series of (n,?) experiments were conducted to measure the correlation between the time after the neutrons enter the lead and the energy of the interaction. Results from these measurements as well as plans for future development of the spectrometer will be discussed.

Casella, Andrew M.; Warren, Glen A.; Cantaloub, Michael G.; Mace, Emily K.; McDonald, Benjamin S.; Overman, Cory T.; Pratt, Sharon L.; Smith, Leon E.; Stave, Sean C.; Wittman, Richard S.

2011-10-01T23:59:59.000Z

200

A Long-Term Record of Aerosol Optical Depth from TOMS Observations and Comparison to AERONET Measurements  

Science Conference Proceedings (OSTI)

Observations of backscattered near-ultraviolet radiation from the Total Ozone Mapping Spectrometer (TOMS) on board the Nimbus-7 (1979–92) and the Earth Probe (mid-1996 to present) satellites have been used to derive a long-term record of aerosol ...

O. Torres; P. K. Bhartia; J. R. Herman; A. Sinyuk; Paul Ginoux; Brent Holben

2002-02-01T23:59:59.000Z

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


201

The Impact of Aerosols on the Summer Rainfall Frequency in China  

Science Conference Proceedings (OSTI)

The authors investigate the short-term relationship between aerosol concentrations and summer rainfall frequency in China using the daily surface observations of particulate matters with a diameter of less than 10 ?m (PM10) mass concentration, ...

Yong-Sang Choi; Chang-Hoi Ho; Jinwon Kim; Dao-Yi Gong; Rokjin J. Park

2008-06-01T23:59:59.000Z

202

Optical and Physical Properties of Atmospheric Aerosols over the Bay of Bengal during ICARB  

Science Conference Proceedings (OSTI)

Simultaneous and collocated measurements of total and hemispherical backscattering coefficients (? and ?, respectively) at three wavelengths, mass size distributions, and columnar spectral aerosol optical depth (AOD) were made onboard an ...

Vijayakumar S. Nair; K. Krishna Moorthy; S. Suresh Babu; S. K. Satheesh

2009-09-01T23:59:59.000Z

203

Portable neutron spectrometer and dosimeter  

DOE Patents (OSTI)

The disclosure relates to a battery operated neutron spectrometer/dosimeter utilizing a microprocessor, a built-in tissue equivalent LET neutron detector, and a 128-channel pulse height analyzer with integral liquid crystal display. The apparatus calculates doses and dose rates from neutrons incident on the detector and displays a spectrum of rad or rem as a function of keV per micron of equivalent tissue and also calculates and displays accumulated dose in millirads and millirem as well as neutron dose rates in millirads per hour and millirem per hour.

Waechter, David A. (Los Alamos, NM); Erkkila, Bruce H. (Los Alamos, NM); Vasilik, Dennis G. (Los Alamos, NM)

1985-01-01T23:59:59.000Z

204

ARM's Aerosol Observing System (AOS) Data  

DOE Data Explorer (OSTI)

The aerosol observing system (AOS) is the primary Atmospheric Radiation Measurement (ARM) platform for in situ aerosol measurements at the surface. The principal measurements are those of the aerosol absorption and scattering coefficients as a function of the particle size and radiation wavelength. Additional measurements include those of the particle number concentration, size distribution, hygroscopic growth, and inorganic chemical composition. The AOS measures aerosol optical properties to better understand how particles interact with solar radiation and influence the earth's radiation balance. The measurements are useful for calculating parameters used in radiative forcing calculations such as the aerosol single scattering albedo, asymmetry parameter, mass scattering efficiency, and hygroscopic growth. [Copied from http://www.arm.gov/instruments/aos]

The ARM Archive at Oak Ridge National Laboratory holds aerosol data from the AOS for two of the permanent ARM sites, North Slope Alaska (NSA) and Southern Great Plains (SGP), as well as from mobile facilities used during specific field campaigns. The AOS has collected data since 1995.

205

Aerosols in a Changing Atmosphere: From Detailed Aerosol Microphysics to  

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

Aerosols in a Changing Atmosphere: From Detailed Aerosol Microphysics to Aerosols in a Changing Atmosphere: From Detailed Aerosol Microphysics to Policy Applications Speaker(s): Susanne Bauer Date: December 6, 2011 - 4:00pm Location: 90-4133 Seminar Host/Point of Contact: Surabi Menon The anthropogenic increase in aerosol concentrations since preindustrial times and its net cooling effect on the atmosphere is thought to mask some of the greenhouse gas induced warming. Although the overall effect of aerosols on solar radiation and clouds is most certainly negative, some individual forcing agents and feedbacks have positive forcing effects. Recent studies have tried to identify some of those positive forcing agents and their individual emission sectors, However, understanding the net effect of multi-source emitting sectors and the involved cloud feedbacks is

206

Synchrotron plus Mass Spectrometer equals New Insights Into Combustion...  

Office of Science (SC) Website

Unique analysis of the reaction of propene with oxygen atom reveals the influence of electron spin on combustion chemistry. Print Text Size: A A A Subscribe FeedbackShare Page...

207

Field-portable mass spectrometers for onsite analytics: What's next?  

Science Conference Proceedings (OSTI)

The need for rapid, onsite chemical analyses is as apparent as it has ever been, especially for compounds detrimental to health or to the environment, such as toxic industrial species, explosives, chemical warfare agents, and environmental toxins. Field-po

208

Mass Spectrometer for High Molecular Weight Ions and Charged Particles  

APPLICATIONS OF TECHNOLOGY: Biotechnology ; Structural biology ; Materials science studies of nanoparticles ; ADVANTAGES:

209

Chemical Bonding and Structural Information of Black Carbon Reference Materials and Individual Carbonaceous Atmospheric Aerosols  

E-Print Network (OSTI)

HULIS) in biomass-burning aerosols, Atmospheric Chemistrymicroscopical and aerosol dynamical characterizationof soot aerosols, Journal of Aerosol Science , 34 , 1347-

Hopkins, Rebecca J.; Tivanski, Alexei V.; Marten, Bryan D.; Gilles, Mary K.

2007-01-01T23:59:59.000Z

210

A Novel Scheme for Parameterizing Aerosol Processing in Warm Clouds  

Science Conference Proceedings (OSTI)

A novel 2-moment bulk aerosol parameterization is derived from a state-of-the-art 2D bin microphysics model using power law relationships and a semi-analytical technique for activation. The activation scheme predicts both number and mass of a ...

Zachary J. Lebo; Hugh Morrison

211

Compact reflective imaging spectrometer utilizing immersed gratings  

DOE Patents (OSTI)

A compact imaging spectrometer comprising an entrance slit for directing light, a first mirror that receives said light and reflects said light, an immersive diffraction grating that diffracts said light, a second mirror that focuses said light, and a detector array that receives said focused light. The compact imaging spectrometer can be utilized for remote sensing imaging spectrometers where size and weight are of primary importance.

Chrisp, Michael P. (Danville, CA)

2006-05-09T23:59:59.000Z

212

Calculating Capstone Depleted Uranium Aerosol Concentrations from Beta Activity Measurements  

SciTech Connect

Beta activity measurements were used as surrogate measurements of uranium mass in aerosol samples collected during the field testing phase of the Capstone Depleted Uranium (DU) Aerosol Study. These aerosol samples generated by the perforation of armored combat vehicles were used to characterize the depleted uranium (DU) source term for the subsequent human health risk assessment (HHRA) of Capstone aerosols. Establishing a calibration curve between beta activity measurements and uranium mass measurements is straightforward if the uranium isotopes are in equilibrium with their immediate short-lived, beta-emitting progeny. For DU samples collected during the Capstone study, it was determined that the equilibrium between the uranium isotopes and their immediate short lived, beta-emitting progeny had been disrupted when penetrators had perforated target vehicles. Adjustments were made to account for the disrupted equilibrium and for wall losses in the aerosol samplers. Correction factors for the disrupted equilibrium ranged from 0.16 to 1, and the wall loss correction factors ranged from 1 to 1.92.

Szrom, Fran; Falo, Gerald A.; Parkhurst, MaryAnn; Whicker, Jeffrey J.; Alberth, David P.

2009-03-01T23:59:59.000Z

213

ATLAS Muon Spectrometer | Brookhaven and the LHC  

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

ATLAS Muon Spectrometer small wheels Brookhaven National Laboratory led the development of the 32 muon detectors in the inner ring of the ATLAS detector's "small wheels." (A small...

214

Pulsed Ionization Source for Ion Mobility Spectrometers  

Mobility Spectrometers Potential Advantages ... ORNL’s new wave of detection devices based on ion mobility spectrometry offer enhanced sensitivity and

215

ARM - Mobile Aerosol Observing System  

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

FacilitiesMobile Aerosol Observing System FacilitiesMobile Aerosol Observing System AMF Information Science Architecture Baseline Instruments AMF1 AMF2 AMF3 Data Operations AMF Fact Sheet Images Contacts AMF Deployments Hyytiälä, Finland, 2014 Manacapuru, Brazil, 2014 Oliktok Point, Alaska, 2013 Los Angeles, California, to Honolulu, Hawaii, 2012 Cape Cod, Massachusetts, 2012 Gan Island, Maldives, 2011 Ganges Valley, India, 2011 Steamboat Springs, Colorado, 2010 Graciosa Island, Azores, 2009-2010 Shouxian, China, 2008 Black Forest, Germany, 2007 Niamey, Niger, 2006 Point Reyes, California, 2005 Mobile Aerosol Observing System Intensive aerosol observations conducted on the campus of Brookhaven National Laboratory on Long Island, New York, using the ARM Mobile Aerosol Observing System. Intensive aerosol observations conducted on the campus of Brookhaven

216

THE ROLE OF SOOT IN AEROSOL CHEMISTRY  

E-Print Network (OSTI)

characterization of aerosols." in Nature. Aim. and MethodsLAWRENCE THE ROLE OF SOOT IN AEROSOL CHEMISTRY T. NovakovTHE ROLE OF SOOT IN AEROSOL CHEMISTRY* T. Novakov Lawrence

Novakov, T.

2010-01-01T23:59:59.000Z

217

Characterizing the formation of secondary organic aerosols  

E-Print Network (OSTI)

and Flagan, R.C. (1990) Aerosol Sci. and Technol. 13 , 230.and Seinfeld, J.H. (2002) Aerosol Science and Technology ,light absorption by atmospheric aerosol, in preparation for

Lunden, Melissa; Black, Douglas; Brown, Nancy

2004-01-01T23:59:59.000Z

218

Optical Properties of Secondary Organic Aerosols  

E-Print Network (OSTI)

Paulson, S. E. ; Chung, A. Aerosol Sci. Technol. 2007 , 41,Y. G. ; Daum, P. H. J. Aerosol Sci 2008 , 39, 974-986. (32)Accurate Monitoring of Terrestrial Aerosols and Total Solar

Kim, Hwajin

2012-01-01T23:59:59.000Z

219

TROPOSPHERIC AEROSOL PROGRAM, PROGRAM PLAN, MARCH 2001  

Science Conference Proceedings (OSTI)

The goal of Tropospheric Aerosol Program (TAP) will be to develop the fundamental scientific understanding required to construct tools for simulating the life cycle of tropospheric aerosols--the processes controlling their mass loading, composition, and microphysical properties, all as a function of time, location, and altitude. The TAP approach to achieving this goal will be by conducting closely linked field, modeling, laboratory, and theoretical studies focused on the processes controlling formation, growth, transport, and deposition of tropospheric aerosols. This understanding will be represented in models suitable for describing these processes on a variety of geographical scales; evaluation of these models will be a key component of TAP field activities. In carrying out these tasks TAP will work closely with other programs in DOE and in other Federal and state agencies, and with the private sector. A forum to directly work with our counterparts in industry to ensure that the results of this research are translated into products that are useful to that community will be provided by NARSTO (formerly the North American Research Strategy on Tropospheric Ozone), a public/private partnership, whose membership spans government, the utilities, industry, and university researchers in Mexico, the US, and Canada.

SCHWARTZ,S.E.; LUNN,P.

2001-03-01T23:59:59.000Z

220

ARM: 10-minute TEMPORARY Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm  

DOE Data Explorer (OSTI)

10-minute TEMPORARY Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

Chitra Sivaraman; Connor Flynn

Note: This page contains sample records for the topic "aerosol mass spectrometer" 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

ARM: 10-minute TEMPORARY Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm  

SciTech Connect

10-minute TEMPORARY Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

Chitra Sivaraman; Connor Flynn

2010-12-15T23:59:59.000Z

222

Side-by-Side Comparison of Particle Count and Mass Concentration  

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

Side-by-Side Comparison of Particle Count and Mass Concentration Side-by-Side Comparison of Particle Count and Mass Concentration Measurements in a Residence Title Side-by-Side Comparison of Particle Count and Mass Concentration Measurements in a Residence Publication Type Report Year of Publication 2011 Authors Chan, Wanyu R., and Federico Noris Publisher Lawrence Berkeley National Laboratory City Berkeley Keywords energy analysis and environmental impacts department Abstract Particulate matter (PM) is a contaminant of concern in many indoor environments, including residential and commercial buildings. Health guidelines for exposure to particles are in units of mass concentrations. Relative to time-integrated mass measurements collected on filters, real-time particle counters are less time-consuming to operate. Studies found reasonable correlation between these two measurement techniques, but agreement may vary in different sampling environments, and depends on the instruments used. We performed a side-by-side comparison of particle counts and mass concentrations estimated by three types of real-time instruments: MetOne BT-637 optical particle counter (OPC), TSI DustTrak aerosol monitor, and TSI aerodynamic particle sizer (APS) spectrometer. In addition to these real-time instruments, time-integrated particle mass was also collected using PM2.5 and PM10 Personal Environmental Monitors (PEMs) manufactured by SKC. Sampling was conducted for two consecutive days in an occupied single-family house in Berkeley, California. Concentration profiles had similar trends, with DustTraks reporting higher particle mass concentrations, partially explained by the density value assumed in the calibration. We made assumptions for particle size and density to calculate the PM2.5 and PM10 mass concentrations for the MetOne and APS, and compared with the filter-based measurements. Despite uncertainties and assumptions, there was generally good agreement for the different methods.

223

EMSL: Science: Atmospheric Aerosol Systems  

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

Atmospheric Aerosol Systems Atmospheric Aerosol Systems atmospheric logo Nighttime enhancement of nitrogen-containing organic compounds, or NOC Observed nighttime enhancement of nitrogen-containing organic compounds, or NOC, showed evidence of being formed by reactions that transform carbonyls into imines. The Atmospheric Aerosol Systems Science Theme focuses on understanding the chemistry, physics and molecular-scale dynamics of aerosols for model parameterization to improve the accuracy of climate model simulations and develop a predictive understanding of climate. By elucidating the role of natural and anthropogenic regional and global climate forcing mechanisms, EMSL can provide DOE and others with the ability to develop cost-effective strategies to monitor, control and mitigate them.

224

Aerosol Metrology for Climate Workshop  

Science Conference Proceedings (OSTI)

... the interaction of aerosols with solar radiation ... that will accelerate the development of new ... together experts from government, industry and academia ...

2012-04-26T23:59:59.000Z

225

The High-Acceptance Dielectron Spectrometer HADES  

E-Print Network (OSTI)

HADES is a versatile magnetic spectrometer aimed at studying dielectron production in pion, proton and heavy-ion induced collisions. Its main features include a ring imaging gas Cherenkov detector for electron-hadron discrimination, a tracking system consisting of a set of 6 superconducting coils producing a toroidal field and drift chambers and a multiplicity and electron trigger array for additional electron-hadron discrimination and event characterization. A two-stage trigger system enhances events containing electrons. The physics program is focused on the investigation of hadron properties in nuclei and in the hot and dense hadronic matter. The detector system is characterized by an 85% azimuthal coverage over a polar angle interval from 18 to 85 degree, a single electron efficiency of 50% and a vector meson mass resolution of 2.5%. Identification of pions, kaons and protons is achieved combining time-of-flight and energy loss measurements over a large momentum range. This paper describes the main features and the performance of the detector system.

The HADES Collaboration; G. Agakishiev; A. Balanda; B. Bannier; R. Bassini; D. Belver; A. V. Belyaev; A. Blanco; M. Boehmer; J. L. Boyard; P. Braun-Munzinger; P. Cabanelas; E. Castro; S. Chernenko; T. Christ; M. Destefanis; J. Diaz; F. Dohrmann; A. Dybczak; T. Eberl; W. Enghardt; L. Fabbietti; O. V. Fateev; P. Finocchiaro; P. Fonte; J. Friese; I. Froehlich; T. Galatyuk; J. A. Garzon; R. Gernhaeuser; A. Gil; C. Gilardi; M. Golubeva; D. Gonzalez-Diaz; F. Guber; M. Heilmann; T. Heinz; T. Hennino; R. Holzmann; A. Ierusalimov; I. Iori; A. Ivashkin; M. Jurkovic; B. Kaempfer; K. Kanaki; T. Karavicheva; D. Kirschner; I. Koenig; W. Koenig; B. W. Kolb; R. Kotte; F. Krizek; R. Kruecken; W. Kuehn; A. Kugler; A. Kurepin; S. Lang; J. S. Lange; K. Lapidus; T. Liu; L. Lopes; M. Lorenz; L. Maier; A. Mangiarotti; J. Markert; V. Metag; B. Michalska; J. Michel; D. Mishra; E. Moriniere; J. Mousa; C. Muentz; L. Naumann; J. Otwinowski; Y. C. Pachmayer; M. Palka; Y. Parpottas; V. Pechenov; O. Pechenova; T. PerezCavalcanti; J. Pietraszko; W. Przygoda; B. Ramstein; A. Reshetin; M. Roy-Stephan; A. Rustamov; A. Sadovsky; B. Sailer; P. Salabura; A. Schmah; E. Schwab; Yu. G. Sobolev; S. Spataro; B. Spruck; H. Stroebele; J. Stroth; C. Sturm; M. Sudol; A. Tarantola; K. Teilab; P. Tlusty; M. Traxler; R. Trebac; H. Tsertos; V. Wagner; M. Weber; M. Wisniowski; T. Wojcik; J. Wuestenfel; S. Yurevich; Y. V. Zanevsky; P. Zhou; P. Zumbruch

2009-02-19T23:59:59.000Z

226

Multi-year Satellite and Surface Observations of AOD in support of Two-Column Aerosol Project (TCAP) Field Campaign  

SciTech Connect

We use combined multi-year measurements from the surface and space for assessing the spatial and temporal distribution of aerosol properties within a large (~400x400 km) region centered on Cape Cod, Massachusetts, along the East Coast of the United States. The ground-based Aerosol Robotic Network (AERONET) measurements at Martha’s Vineyard Coastal Observatory (MVCO) site and Moderate Resolution Imaging Spectrometer (MODIS) sensors on board the Terra and Aqua satellites provide horizontal and temporal variations of aerosol optical depth, while the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) offers the altitudes of aerosol-layers. The combined ground-based and satellite measurements indicated several interesting features among which were the large differences in the aerosol properties observed in July and February. We applied the climatology of aerosol properties for designing the Two-Column Aerosol Project (TCAP), which is supported by the U.S. Department of Energy’s (DOE’s) Atmospheric Radiation Measurement (ARM) Program. The TCAP field campaign involves 12-month deployment (started July 1, 2012) of the ground-based ARM Mobile Facility (AMF) and Mobile Aerosol Observing System (MAOS) on Cape Cod and complimentary aerosol observations from two research aircraft: the DOE Gulfstream-1 (G-1) and the National Aeronautics and Space Administration (NASA) B200 King Air. Using results from the coordinated G-1 and B200 flights during the recent (July, 2012) Intensive Observation Period, we demonstrated that the G-1 in situ measurements and B200 active remote sensing can provide complementary information on the temporal and spatial changes of the aerosol properties off the coast of North America.

Kassianov, Evgueni I.; Chand, Duli; Berg, Larry K.; Fast, Jerome D.; Tomlinson, Jason M.; Ferrare, R.; Hostetler, Chris A.; Hair, John

2012-11-01T23:59:59.000Z

227

Researchers Model Impact of Aerosols Over California  

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

Researchers Model Impact of Aerosols Over California Researchers Model Impact of Aerosols Over California Research may clarify the effectiveness of regional pollution controls May...

228

Thermophoretic separation of aerosol particles from a sampled gas stream  

DOE Patents (OSTI)

This disclosure relates to separation of aerosol particles from gas samples withdrawn from within a contained atmosphere, such as containment vessels for nuclear reactors or other process equipment where remote gaseous sampling is required. It is specifically directed to separation of dense aerosols including particles of any size and at high mass loadings and high corrosivity. The United States Government has rights in this invention pursuant to Contract DE-AC06-76FF02170 between the US Department of Energy and Westinghouse Electric Corporation.

Postma, A.K.

1984-09-07T23:59:59.000Z

229

Vertical distribution of aerosols in the vicinity of Mexico City during MILAGRO-2006 Campaign  

Science Conference Proceedings (OSTI)

On 7 March 2006, a mobile, ground-based, vertical pointing, elastic lidar system made a North-South transect through the Mexico City basin. Column averaged, aerosol size distribution (ASD) measurements were made on the ground concurrently with the lidar measurements. The ASD ground measurements allowed calculation of the column averaged mass extinction efficiency (MEE) for the lidar system (1064 nm). The value of column averaged MEE was combined with spatially resolved lidar extinction coefficients to produce total aerosol mass concentration estimates with the resolution of the lidar (1.5 m vertical spatial and 1 s temporal). Airborne ASD measurements from DOE G-1 aircraft made later in the day on 7 March 2006, allowed the evaluation of the assumptions of constant ASD with height and time used for estimating the column averaged MEE. The results showed that the aerosol loading within the basin is about twice what is observed outside of the basin. The total aerosol base concentrations observed in the basin are of the order of 200 {mu}g/m{sup 3} and the base levels outside are of the order of 100 {mu}g/m{sup 3}. The local heavy traffic events can introduce aerosol levels near the ground as high as 900 {mu}g/m{sup 3}. The article presents the methodology for estimating aerosol mass concentration from mobile, ground-based lidar measurements in combination with aerosol size distribution measurements. An uncertainty analysis of the methodology is also presented.

Lewandowski, P.A.; Kleinman, L.; Eichinger, W. E.; Holder, H.; Prueger, J.; Wang, J.

2010-02-01T23:59:59.000Z

230

Reduction of photosynthetically active radiation under extreme stratospheric aerosol loads  

Science Conference Proceedings (OSTI)

The recently published hypothesis that the Cretaceous-Tertiary extinctions might be caused by an obstruction of sunlight is tested by model calculations. First we compute the total mass of stratospheric aerosols under normal atmospheric conditions for four different (measured) aerosol size distributions and vertical profiles. For comparison, the stratospheric dust masses after four volcanic eruptions are also evaluated. Detailed solar radiative transfer calculations are then performed for artificially increased aerosol amounts until the postulated darkness scenario is obtained. Thus we find that a total stratospheric aerosol mass between 1 and 4 times 10/sup 1/ g is sufficient to reduce photosynthesis to 10/sup -3/ of normal. We also infer from this result tha the impact of a 0.4- to 3-km-diameter asteroid or a close encounter with a Halley-size comet may deposit that amount of particulates into the stratosphere. The darkness scenario of Alvarez et al. is thus shown to be a possible extinction mechanism, even with smaller size asteroids of comets than previously estimated.

Gerstl, S.A.W.; Zardecki, A.

1981-08-01T23:59:59.000Z

231

Chip-scale quadrupole mass filters for a Micro-Gas Analyzer  

E-Print Network (OSTI)

Mass spectrometers are powerful analytical instruments that serve as the gold standard for chemical analysis. This tool has numerous applications ranging from national security, industrial processing, environmental monitoring, ...

Cheung, Kerry

2009-01-01T23:59:59.000Z

232

Mechanisms of Formation of Secondary Organic Aerosols and Implications for Global Radiative Forcing  

Science Conference Proceedings (OSTI)

Organic material constitutes about 50% of global atmospheric aerosol mass, and the dominant source of organic aerosol is the oxidation of volatile hydrocarbons, to produce secondary organic aerosol (SOA). Understanding the formation of SOA is crucial to predicting present and future climate effects of atmospheric aerosols. The goal of this program is to significantly increase our understanding of secondary organic aerosol (SOA) formation in the atmosphere. Ambient measurements indicate that the amount of SOA in the atmosphere exceeds that predicted in current models based on existing laboratory chamber data. This would suggest that either the SOA yields measured in laboratory chambers are understated or that all major organic precursors have not been identified. In this research program we are systematically exploring these possibilities.

John H. Seinfeld

2011-12-08T23:59:59.000Z

233

Photolytically generated aerosols in the mesosphere and thermosphere of Titan  

E-Print Network (OSTI)

Analysis of the Cassini Ultraviolet Imaging Spectrometer (UVIS) stellar and solar occultations at Titan to date include 12 species: N$_{2}$ (nitrogen), CH$_{4}$ (methane), C$_{2}$H$_{2}$ (acetylene), C$_{2}$H$_{4}$ (ethylene), C$_{2}$H$_{6}$ (ethane), C$_{4}$H$_{2}$ (diacetylene), C$_{6}$H$_{6}$ (benzene), C$_{6}$N$_{2}$ (dicyanodiacetylene), C$_{2}$N$_{2}$ (cyanogen), HCN (hydrogen cyanide), HC$_{3}$N (cyanoacetylene), and aerosols distinguished by a structureless continuum extinction (absorption plus scattering) of photons in the EUV. The introduction of aerosol particles, retaining the same refractive index properties as tholin with radius $\\sim$125 \\AA and using Mie theory, provides a satisfactory fit to the spectra. The derived vertical profile of aerosol density shows distinct structure, implying a reactive generation process reaching altitudes more than 1000 km above the surface. A photochemical model presented here provides a reference basis for examining the chemical and physical processes leading to the distinctive atmospheric opacity at Titan. We find that dicyanodiacetylene is condensable at $\\sim$650 km, where the atmospheric temperature minimum is located. This species is the simplest molecule identified to be condensable. Observations are needed to confirm the existence and production rates of dicyanodiacetylene.

Mao-Chang Liang; Yuk L. Yung; Donald E. Shemansky

2007-05-01T23:59:59.000Z

234

Nanomaterials from Aerosols Aerosols are suspensions of liquid or solid particles in a gas. Aerosol particles  

E-Print Network (OSTI)

arid regions in China and Africa. Such aerosol streams have been shown to travel around the globe with silica aerosols from China impacting air quality in the continental US and #12;2 alumina and titania delivery mechanisms for a variety of drugs as an alternative to injections. As delivery devices

Beaucage, Gregory

235

The Vibrational Spectrometer at SNS | ORNL Neutron Sciences  

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

Vibrational Spectrometer at SNS VISION VISION is best thought of as the neutron analogue of an infrared-Raman spectrometer. It is optimized to characterize molecular vibrations in...

236

HYSPEC: the Hybrid Spectrometer at SNS | ORNL Neutron Sciences  

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

Hybrid Spectrometer at SNS Hybrid Spectrometer Schematic of the HYSPEC instrument Developed by a team from leading U.S. universities and national laboratories and an international...

237

The effect of aerosol vertical profiles on satellite-estimated surface particle sulfate concentrations  

SciTech Connect

The aerosol vertical distribution is an important factor in determining the relationship between satellite retrieved aerosol optical depth (AOD) and ground-level fine particle pollution concentrations. We evaluate how aerosol profiles measured by ground-based lidar and simulated by models can help improve the association between AOD retrieved by the Multi-angle Imaging Spectroradiometer (MISR) and fine particle sulfate (SO4) concentrations using matched data at two lidar sites. At the Goddard Space Flight Center (GSFC) site, both lidar and model aerosol profiles marginally improve the association between SO4 concentrations and MISR fractional AODs, as the correlation coefficient between cross-validation (CV) and observed SO4 concentrations changes from 0.87 for the no-scaling model to 0.88 for models scaled with aerosol vertical profiles. At the GSFC site, a large amount of urban aerosols resides in the well-mixed boundary layer so the column fractional AODs are already excellent indicators of ground-level particle pollution. In contrast, at the Atmospheric Radiation Measurement Program (ARM) site with relatively low aerosol loadings, scaling substantially improves model performance. The correlation coefficient between CV and observed SO4 concentrations is increased from 0.58 for the no-scaling model to 0.76 in the GEOS-Chem scaling model, and the model bias is reduced from 17% to 9%. In summary, despite the inaccuracy due to the coarse horizontal resolution and the challenges of simulating turbulent mixing in the boundary layer, GEOS-Chem simulated aerosol profiles can still improve methods for estimating surface aerosol (SO4) mass from satellite-based AODs, particularly in rural areas where aerosols in the free troposphere and any long-range transport of aerosols can significantly contribute to the column AOD.

Liu, Yang; Wang, Zifeng; Wang, Jun; Ferrare, Richard A.; Newsom, Rob K.; Welton, Ellsworth J.

2011-02-15T23:59:59.000Z

238

Aerosol Laboratory - Nuclear Engineering Division (Argonne)  

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

Capabilities > Engineering Capabilities > Engineering Experimentation > Aerosol Laboratory Capabilities Engineering Experimentation Reactor Safety Experimentation Aerosol Experiments System Components Laser Applications Robots Applications Other Facilities Other Capabilities Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Aerosol Laboratory The Aerosol Laboratory (AL) houses equipment to measure and record the physical parameters necessary to characterize the formation and transport of aerosols. Bookmark and Share The Aerosol Laboratory (AL) has extensive analytic and experimental capabilities to characterize the formation and transport of aerosols formed from the condensation of vapors. Computer codes have been developed to

239

EMSL: Capabilities: Mass Spectrometry: Next-Generation Mass Spectrometry  

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

Next-Generation Mass Spectrometry Next-Generation Mass Spectrometry Additional Information Meet the Mass Spectrometry Experts Related EMSL User Projects Mass Spectrometry Tools are Applied to all Science Themes Next-Generation Mass Spectrometry Proteomics Research Resource for Integrative Biology Biological and Environmental Research - PNNL Proteomics PNNL's Biological MS Data and Software Distribution Center Mass Spectrometry brochure EMSL is committed to offering state-of-the-art instruments to its users. At a workshop in January of 2008, EMSL mass spectrometry experts joined experts from many universities, private companies, and government institutions and laboratories at a conference held at the National High Magnetic Field Laboratory in Tallahassee Florida. Workshop participants reviewed the state of the art of high-performance mass spectrometers,

240

2 IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING, VOL. 3(1. NO. i. JANLTARY 1992 Remote Sensing of Cloud, Aerosol, and  

E-Print Network (OSTI)

companion instrument MODIS-T (tilt), a tiltable cross-track scanning spectrometer with 32 uniformly spaced (EOS) is well suited to the global monitoring of atmospheric prop- erties from space. In addition channels (250 m), will permit state-of-the-art global monitoring of atmospheric water vapor, aerosol

Christopher, Sundar A.

Note: This page contains sample records for the topic "aerosol mass spectrometer" 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

Results and code prediction comparisons of lithium-air reaction and aerosol behavior tests  

Science Conference Proceedings (OSTI)

The Hanford Engineering Development Laboratory (HEDL) Fusion Safety Support Studies include evaluation of potential safety and environmental concerns associated with the use of liquid lithium as a breeder and coolant for fusion reactors. Potential mechanisms for volatilization and transport of radioactive metallic species associated with breeder materials are of particular interest. Liquid lithium pool-air reaction and aerosol behavior tests were conducted with lithium masses up to 100 kg within the 850-m/sup 3/ containment vessel in the Containment Systems Test Facility. Lithium-air reaction rates, aerosol generation rates, aerosol behavior and characterization, as well as containment atmosphere temperature and pressure responses were determined. Pool-air reaction and aerosol behavior test results were compared with computer code calculations for reaction rates, containment atmosphere response, and aerosol behavior. The volatility of potentially radioactive metallic species from a lithium pool-air reaction was measured. The response of various aerosol detectors to the aerosol generated was determined. Liquid lithium spray tests in air and in nitrogen atmospheres were conducted with lithium temperatures of about 427/sup 0/ and 650/sup 0/C. Lithium reaction rates, containment atmosphere response, and aerosol generation and characterization were determined for these spray tests.

Jeppson, D.W.

1986-03-01T23:59:59.000Z

242

Soft ionization of thermally evaporated hypergolic ionic liquid aerosols  

E-Print Network (OSTI)

+ ][Dca ? ]. Figure 2. Aerosol particle size distribution ofhypergolic ionic liquid aerosols Christine J. Koh † , Chen-ionization of evaporated IL aerosols Isolated ion pairs of a

Koh, Christine J.

2013-01-01T23:59:59.000Z

243

ATMOSPHERIC AEROSOL RESEARCH ANNUAL REPORT 1975-76  

E-Print Network (OSTI)

this room ATMOSPHERIC AEROSOL RESEARCH -RECEIVED •I.AWSSKCEDIVISION ATMOSPHERIC AEROSOL RESEARCH ANNUAL REPORTMass and Composition of Aerosol as a Function of Time,

Novakov, T.

2010-01-01T23:59:59.000Z

244

Response of California temperature to regional anthropogenic aerosol changes  

E-Print Network (OSTI)

to regional anthropogenic aerosol changes T. Novakov, T.W.indicator of anthropogenic aerosols – with observed surfacetemperature increase. Seasonal aerosol concentration trends

Novakov, T.

2008-01-01T23:59:59.000Z

245

Aerosol measurements with laser-induced breakdown spectroscopy  

E-Print Network (OSTI)

anthropogenic sulfate aerosols. Tellus, Ser. A, vol. 43, p.Twomey, Atmospheric Aerosols. New York : Elsevier ScientificCo. , 45. B.A. Albrecht, Aerosols, cloud microphysics, and

Lithgow, Gregg Arthur

2007-01-01T23:59:59.000Z

246

ATMOSPHERIC AEROSOL RESEARCH, ANNUAL REPORT 1976-77  

E-Print Network (OSTI)

DIVISION ATMOSPHERIC AEROSOL RESEARCH ANNUAL REPORTLow-Z Elements in Atmospheric Aerosol Particles by Nuclearof sulfur dioxide by aerosols of manganese sulfate," Ind.

Novakov, T.

2010-01-01T23:59:59.000Z

247

Black carbon aerosols and the third polar ice cap  

E-Print Network (OSTI)

estimations in global aerosol models, Atmos. Chem. Phys. ,Cloud mi- crophysics and aerosol indirect efefcts in theuncertainties in assessing aerosol effects on climate, Ann.

Menon, Surabi

2010-01-01T23:59:59.000Z

248

Total aerosol effect: forcing or radiative flux perturbation?  

E-Print Network (OSTI)

of the ?rst indirect aerosol effect, Atmos. Chem. Phys. , 5,Cloud susceptibility and the ?rst aerosol indirect forcing:to black carbon and aerosol concentrations, J. Geophys.

Lohmann, Ulrike

2010-01-01T23:59:59.000Z

249

Development of an Inexpensive Raindrop Size Spectrometer  

Science Conference Proceedings (OSTI)

The deployment of weather radar, notably in mountainous terrain with many microclimates, requires the use of several or even many drop size spectrometers to provide confidence in the quantitative relation between radar reflectivity and rainfall. ...

William Henson; Geoff Austin; Harry Oudenhoven

2004-11-01T23:59:59.000Z

250

LCLS Injector Straight-Ahead Spectrometer  

Science Conference Proceedings (OSTI)

The spectrometer design was modified to allow the measurement of uncorrelated energy spread for the nominal lattice. One bunch from every 120 each second would be sent to the straight ahead spectrometer while the transverse cavity is on. The implementation of this 'stealing mode' will not be available for the LCLS commissioning and the early stage of operation. However, the spectrometer was redesigned to retain that option. The energy feedback relies independently on the beam position of the beam in the dispersive section of dogleg 1 (DL1). The main modification of the spectrometer design is the Pole face rotation of 7.5 degrees on both entrance and exit faces. The location and range of operation of the 3 quadrupoles remains unchanged relative to those of the earlier design.

Limborg-Deprey , C.

2010-12-10T23:59:59.000Z

251

GCM Aerosol Radiative Effects Using Geographically Varying Aerosol Sizes Deduced from AERONET Measurements  

Science Conference Proceedings (OSTI)

Aerosol optical properties, and hence the direct radiative effects, are largely determined by the assumed aerosol size distribution. In order to relax the fixed aerosol size constraint commonly used in general circulation models (GCMs), ...

Glen Lesins; Ulrike Lohmann

2003-11-01T23:59:59.000Z

252

AERONET: The Aerosol Robotic Network  

DOE Data Explorer (OSTI)

AERONET collaboration provides globally distributed observations of spectral aerosol optical Depth (AOD), inversion products, and precipitable water in diverse aerosol regimes. Aerosol optical depth data are computed for three data quality levels: Level 1.0 (unscreened), Level 1.5 (cloud-screened), and Level 2.0 (cloud screened and quality-assured). Inversions, precipitable water, and other AOD-dependent products are derived from these levels and may implement additional quality checks.[Copied from http://aeronet.gsfc.nasa.gov/new_web/system_descriptions.html

253

1987 calibration of the TFTR neutron spectrometers  

SciTech Connect

The {sup 3}He neutron spectrometer used for measuring ion temperatures and the NE213 proton recoil spectrometer used for triton burnup measurements were absolutely calibrated with DT and DD neutron generators placed inside the TFTR vacuum vessel. The details of the detector response and calibration are presented. Comparisons are made to the neutron source strengths measured from other calibrated systems. 23 refs., 19 figs., 6 tabs.

Barnes, C.W.; Strachan, J.D. (Los Alamos National Lab., NM (USA); Princeton Univ., NJ (USA). Plasma Physics Lab.)

1989-12-01T23:59:59.000Z

254

E parallel B canted detector neutral-particle spectrometer  

DOE Green Energy (OSTI)

A multichannel, mass-discriminating, neutral-particle spectrometer using parallel E and B analyzer fields has been operational on the Doublet III tokamak. The device records 60 energy channels each of hydrogen and deuterium, simultaneously, during a shot with a dynamic range in energy of greater than 20. Its unique feature is a microchannel plate detector plane set at an angle to the exit face of the magnet. This angled detector plane linearizes the columns of each mass which simplifies the detector design, and permits the magnet gap to be very small. The narrow gap minimizes figure field effects on particle trajectories and simplifies power supply and cooling design. Details are given on the design, calibration, and instrumentation of the device, as well as on its operation and experimental results.

Armentrout, C.J.; Bramson, G.; Evanko, R.

1985-11-01T23:59:59.000Z

255

Analyzing signatures of aerosol-cloud interactions from satellite retrievals and the GISS GCM to constrain the aerosol indirect effect  

E-Print Network (OSTI)

dust, and pollution aerosol on shallow cloud developmentclouds on indirect aerosol climate forcing, Nature, 432,1014– Albrecht, B. A. , Aerosols, cloud microphysics, and

2008-01-01T23:59:59.000Z

256

A support vector machine model for the prediction of proteotypic peptides for accurate mass and time proteomics  

Science Conference Proceedings (OSTI)

Motivation: The standard approach to identifying peptides based on accurate mass and elution time (AMT) compares profiles obtained from a high resolution mass spectrometer to a database of peptides previously identified from tandem mass spectrometry ...

Bobbie-Jo M. Webb-Robertson; William R. Cannon; Christopher S. Oehmen; Anuj R. Shah; Vidhya Gurumoorthi; Mary S. Lipton; Katrina M. Waters

2010-07-01T23:59:59.000Z

257

A support vector machine model for the prediction of proteotypic peptides for accurate mass and time proteomics  

Science Conference Proceedings (OSTI)

Motivation: The standard approach to identifying peptides based on accurate mass and elution time (AMT) compares profiles obtained from a high resolution mass spectrometer to a database of peptides previously identified from tandem mass spectrometry ...

Bobbie-Jo M. Webb-Robertson; William R. Cannon; Christopher S. Oehmen; Anuj R. Shah; Vidhya Gurumoorthi; Mary S. Lipton; Katrina M. Waters

2008-07-01T23:59:59.000Z

258

ARM - Surface Aerosol Observing System  

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

FacilitiesSurface Aerosol Observing System FacilitiesSurface Aerosol Observing System AMF Information Science Architecture Baseline Instruments AMF1 AMF2 AMF3 Data Operations AMF Fact Sheet Images Contacts AMF Deployments Hyytiälä, Finland, 2014 Manacapuru, Brazil, 2014 Oliktok Point, Alaska, 2013 Los Angeles, California, to Honolulu, Hawaii, 2012 Cape Cod, Massachusetts, 2012 Gan Island, Maldives, 2011 Ganges Valley, India, 2011 Steamboat Springs, Colorado, 2010 Graciosa Island, Azores, 2009-2010 Shouxian, China, 2008 Black Forest, Germany, 2007 Niamey, Niger, 2006 Point Reyes, California, 2005 Surface Aerosol Observing System The ARM Mobile Facility (AMF) is equipped to quantify the interaction between clouds and aerosol particles. A counter-flow virtual impactor (CVI) is used to selectively sample cloud drops. The CVI takes advantage of the

259

Two-Column Aerosol Project  

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

Climate Research Facility is conducting the Two-Column Aerosol Project (TCAP) at Cape Cod National Seashore. From July 2012 to June 2013, the ARM Mobile Facility-a portable...

260

Mesoscale Variations of Tropospheric Aerosols  

Science Conference Proceedings (OSTI)

Tropospheric aerosols are calculated to cause global-scale changes in the earth's heat balance, but these forcings are space/time integrals over highly variable quantities. Accurate quantification of these forcings will require an unprecedented ...

Theodore L. Anderson; Robert J. Charlson; David M. Winker; John A. Ogren; Kim Holmén

2003-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol mass spectrometer" 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

Method for producing monodisperse aerosols  

DOE Patents (OSTI)

An aerosol generator is described which is capable of producing a monodisperse aerosol within narrow limits utilizing an aqueous solution capable of providing a high population of seed nuclei and an organic solution having a low vapor pressure. The two solutions are cold nebulized, mixed, vaporized, and cooled. During cooling, particles of the organic vapor condense onto the excess seed nuclei, and grow to a uniform particle size.

Ortiz, Lawrence W. (Los Alamos, NM); Soderholm, Sidney C. (Pittsford, NY)

1990-01-01T23:59:59.000Z

262

Airborne measurements of carbonaceous aerosols in southern Africa during  

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

Airborne measurements of carbonaceous aerosols in southern Africa during Airborne measurements of carbonaceous aerosols in southern Africa during the dry, biomass burning season Title Airborne measurements of carbonaceous aerosols in southern Africa during the dry, biomass burning season Publication Type Journal Article LBNL Report Number LBNL-50880 Year of Publication 2003 Authors Kirchstetter, Thomas W., Tihomir Novakov, and Peter V. Hobbs Journal Journal of Geophysical Research - Atmospheres Keywords black carbon, evolved gas analysis, light absorption, organic carbon, positive sampling artifact, SAFARI Abstract Particulate matter collected aboard the University of Washington's Convair-580 research aircraft over southern Africa during the dry, biomass burning season was analyzed for total carbon, organic carbon, and black carbon contents using thermal and optical methods. Samples were collected in smoke plumes of burning savanna and in regional haze. A known artifact, produced by the adsorption of organic gases on the quartz filter substrates used to collect the particulate matter samples, comprised a significant portion of the total carbon collected. Consequently, conclusions derived from the data are greatly dependent on whether or not organic carbon concentrations are corrected for this artifact. For example, the estimated aerosol co-albedo (1 - single scattering albedo), which is a measure of aerosol absorption, of the biomass smoke samples is 60% larger using corrected organic carbon concentrations. Thus, the corrected data imply that the biomass smoke is 60% more absorbing than do the uncorrected data. The black carbon to (corrected) organic carbon mass ratio (BC/OC) of smoke plume samples (0.18±0.06) is lower than that of samples collected in the regional haze (0.25±0.08). The difference may be due to mixing of biomass smoke with background air characterized by a higher BC/OC ratio. A simple source apportionment indicates that biomass smoke contributes about three-quarters of the aerosol burden in the regional haze, while other sources (e.g., fossil fuel burning) contribute the remainder.

263

Background Stratospheric Aerosol Variations Deduced from Satellite Observations  

Science Conference Proceedings (OSTI)

The Stratospheric Aerosol and Gas Experiment II (SAGE II) aerosol products from 1998 to 2004 have been analyzed for the tendency of changes in background stratospheric aerosol properties. The aerosol extinction coefficient E has apparently ...

Yu Liu; Xuepeng Zhao; Weiliang Li; Xiuji Zhou

2012-04-01T23:59:59.000Z

264

Vapor scavenging by atmospheric aerosol particles  

Science Conference Proceedings (OSTI)

Particle growth due to vapor scavenging was studied using both experimental and computational techniques. Vapor scavenging by particles is an important physical process in the atmosphere because it can result in changes to particle properties (e.g., size, shape, composition, and activity) and, thus, influence atmospheric phenomena in which particles play a role, such as cloud formation and long range transport. The influence of organic vapor on the evolution of a particle mass size distribution was investigated using a modified version of MAEROS (a multicomponent aerosol dynamics code). The modeling study attempted to identify the sources of organic aerosol observed by Novakov and Penner (1993) in a field study in Puerto Rico. Experimentally, vapor scavenging and particle growth were investigated using two techniques. The influence of the presence of organic vapor on the particle`s hydroscopicity was investigated using an electrodynamic balance. The charge on a particle was investigated theoretically and experimentally. A prototype apparatus--the refractive index thermal diffusion chamber (RITDC)--was developed to study multiple particles in the same environment at the same time.

Andrews, E.

1996-05-01T23:59:59.000Z

265

Thermodynamic Characterization of Mexico City Aerosol during MILAGRO 2006  

E-Print Network (OSTI)

Thermodynamic Characterization of Mexico City Aerosol duringA computationally efficient thermodynamic equilibrium modelurban aerosols determined by thermodynamic equilibrium? An

Fountoukis, C.

2009-01-01T23:59:59.000Z

266

OH-initiated heterogeneous aging of highly oxidized organic aerosol  

Science Conference Proceedings (OSTI)

The oxidative evolution (“aging”) of organic species in the atmosphere is thought to have a major influence on the composition and properties of organic particulate matter, but remains poorly understood, particularly for the most oxidized fraction of the aerosol. Here we measure the kinetics and products of the heterogeneous oxidation of highly oxidized organic aerosol, with an aim of better constraining such atmospheric aging processes. Submicron particles composed of model oxidized organics—1,2,3,4-butanetetracarboxylic acid (C{sub 8}H{sub 10}O{sub 8}), citric acid (C{sub 6}H{sub 8}O{sub 7}), tartaric acid (C{sub 4}H{sub 6}O{sub 6}), and Suwannee River fulvic acid—were oxidized by gas-phase OH in a flow reactor, and the masses and elemental composition of the particles were monitored as a function of OH exposure. In contrast to our previous studies of less-oxidized model systems (squalane, erythritol, and levoglucosan), particle mass did not decrease significantly with heterogeneous oxidation. Carbon content of the aerosol always decreased somewhat, but this mass loss was approximately balanced by an increase in oxygen content. The estimated reactive uptake coefficients of the reactions range from 0.37 to 0.51 and indicate that such transformations occur at rates corresponding to 1-2 weeks in the atmosphere, suggesting their importance in the atmospheric lifecycle of organic particulate matter.

Kessler, Sean H.; Nah, Theodora; Daumit, Kelly E.; Smith, Jared D.; Leone, Stephen R.; Kolb, Charles E.; Worsnop, Douglas R.; Wilson, Kevin R.; Kroll, Jesse H.

2011-12-05T23:59:59.000Z

267

Composition of carbonaceous smoke particles from prescribed burning of a Canadian boreal forest: 1. Organic aerosol characterization by gas chromatography  

SciTech Connect

In this study we examine the molecular organic constituents (C8 to C40 lipid compounds) collected as smoke particles from a Canadian boreal forest prescribed burn. Of special interest are (1) the molecular identity of polar organic aerosols, and (2) the amount of polar organic matter relative to the total mass of aerosol particulate carbon. Organic extracts of smoke aerosol particles show complex distributions of the lipid compounds when analyzed by capillary gas chromatography/mass spectrometry. The molecular constituents present as smoke aerosol are grouped into non-polar (hydrocarbons) and polar {minus}2 oxygen atoms) subtractions. The dominant chemical species found in the boreal forest smoke aerosol are unaltered resin compounds (C20 terpenes) which are abundant in unburned conifer wood, plus thermally altered wood lignins and other polar aromatic hydrocarbons. Our results show that smoke aerosols contain molecular tracers which are related to the biofuel consumed. These smoke tracers can be related structurally back to the consumed softwood and hardwood vegetation. In addition, combustion of boreal forest materials produces smoke aerosol particles that are both oxygen-rich and chemically complex, yielding a carbonaceous aerosol matrix that is enriched in polar substances. As a consequence, emissions of carbonaceous smoke particles from large-scale combustion of boreal forest land may have a disproportionate effect on regional atmospheric chemistry and on cloud microphysical processes.

Mazurek, M.A.; Laterza, C.; Newman, L.; Daum, P. [Brookhaven National Lab., Upton, NY (United States); Cofer, W.R. III; Levine, J.S. [National Aeronautics and Space Administration, Hampton, VA (United States). Langley Research Center; Winstead, E.L. [Science Applications International Corporation, Hampton, VA (United States)

1995-06-01T23:59:59.000Z

268

Importance of aerosol composition, mixing state, and morphology for heterogeneous ice nucleation: A combined field and laboratory approach  

Science Conference Proceedings (OSTI)

In this study chemical compositions of background aerosol and ice nuclei were examined through laboratory investigations using Raman spectroscopy and field measurements by single-particle mass spectrometry. Aerosol sampling took place at Storm Peak Laboratory in Steamboat Springs, Colorado (elevation of 3210 m). A cascade impactor was used to collect coarse-mode aerosol particles for laboratory analysis by Raman spectroscopy; the composition, mixing state, and heterogeneous ice nucleation activity of individual particles were examined. For in situ analysis of fine-mode aerosol, ice nucleation on ambient particles was observed using a compact ice nucleation chamber. Ice crystals were separated from unactivated aerosol using a pumped counterflow virtual impactor, and ice nuclei were analyzed using particle analysis by laser mass spectrometry. For both fine and coarse modes, the ice nucleating particle fractions were enriched in minerals and depleted in sulfates and nitrates, compared to the background aerosol sampled. The vast majority of particles in both the ambient and ice active aerosol fractions contained a detectable amount of organic material. Raman spectroscopy showed that organic material is sometimes present in the form of a coating on the surface of inorganic particles. We find that some organic-containing particles serve as efficient ice nuclei while others do not. For coarse-mode aerosol, organic particles were only observed to initiate ice formation when oxygen signatures were also present in their spectra.

Baustian, Kelly J.; Cziczo, Daniel J.; Wise, M. A.; Pratt, Kerri; Kulkarni, Gourihar R.; Hallar, Anna G.; Tolbert, Margaret A.

2012-03-30T23:59:59.000Z

269

Subarctic atmospheric aerosol composition: 1. Ambient aerosol characterization  

SciTech Connect

Sub-Arctic aerosol was sampled during July 2007 at the Abisko Research Station Stordalen field site operated by the Royal Swedish Academy of Sciences. Located in northern Sweden at 68º latitude and 385 meters above sea level (msl), this site is classified as a semi-continuous permafrost mire. Number density, size distribution, cloud condensation nucleus properties, and chemical composition of the ambient aerosol were determined. Backtrajectories showed that three distinct airmasses were present over Stordalen during the sampling period. Aerosol properties changed and correlated with airmass origin to the south, northeast, or west. We observe that Arctic aerosol is not compositionally unlike that found in the free troposphere at mid-latitudes. Internal mixtures of sulfates and organics, many on insoluble biomass burning and/or elemental carbon cores, dominate the number density of particles from ~200 to 2000 nm aerodynamic diameter. Mineral dust which had taken up gas phase species was observed in all airmasses. Sea salt, and the extent to which it had lost volatile components, was the aerosol type that most varied with airmass.

Friedman, Beth; Herich, Hanna; Kammermann, Lukas; Gross, Deborah S.; Ameth, Almut; Holst, Thomas; Lohmann, U.; Cziczo, Daniel J.

2009-07-10T23:59:59.000Z

270

Structural determination of intact proteins using mass spectrometry  

DOE Patents (OSTI)

The present invention relates to novel methods of determining the sequence and structure of proteins. Specifically, the present invention allows for the analysis of intact proteins within a mass spectrometer. Therefore, preparatory separations need not be performed prior to introducing a protein sample into the mass spectrometer. Also disclosed herein are new instrumental developments for enhancing the signal from the desired modified proteins, methods for producing controlled protein fragments in the mass spectrometer, eliminating complex microseparations, and protein preparatory chemical steps necessary for cross-linking based protein structure determination.Additionally, the preferred method of the present invention involves the determination of protein structures utilizing a top-down analysis of protein structures to search for covalent modifications. In the preferred method, intact proteins are ionized and fragmented within the mass spectrometer.

Kruppa, Gary (San Francisco, CA); Schoeniger, Joseph S. (Oakland, CA); Young, Malin M. (Livermore, CA)

2008-05-06T23:59:59.000Z

271

Aerosol Properties from Multi-spectral and Multi-angular Aircraft 4STAR Observations: Expected Advantages and Challenges  

SciTech Connect

The airborne Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR) is developed to retrieve aerosol microphysical and optical properties from multi-angular and multi-spectral measurements of sky radiance and direct-beam sun transmittance. The necessarily compact design of the 4STAR may cause noticeable apparent enhancement of sky radiance at small scattering angles. We assess the sensitivity of expected 4STAR-based aerosol retrieval to such enhancement by applying the operational AERONET retrieval code and constructed synthetic 4STARlike data. Also, we assess the sensitivity of the broadband fluxes and the direct aerosol radiative forcing to uncertainties in aerosol retrievals associated with the sky radiance enhancement. Our sensitivity study results suggest that the 4STARbased aerosol retrieval has limitations in obtaining detailed information on particle size distribution and scattering phase function. However, these limitations have small impact on the retrieved bulk optical parameters, such as the asymmetry factor (up to 4%, or ±0.02) and single-scattering albedo (up to 2%, or ±0.02), and the calculated direct aerosol radiative forcing (up to 6%, or 2 Wm-2).

Kassianov, Evgueni I.; Flynn, Connor J.; Redemann, Jens; Schmid, Beat; Russell, P. B.; Sinyuk, Alexander

2012-11-01T23:59:59.000Z

272

Partial pressure measurements with an active spectrometer  

SciTech Connect

Partial pressure neutral ga measurements have been made using a commercial Penning gauge in conjunction with an active spectrometer. In prior work utilizing bandpass filters and conventional spectrometers, trace concentrations of the hydrogen isotopes H, D, T and of the noble gases He, Ne and Ar were determined from characteristic spectral lines in the light emitted by the neutral species of these elements. For all the elements mentioned, the sensitivity was limited by spectral contamination from a pervasive background of molecular hydrogen radiation. The active spectrometer overcomes this limitations by means of a digital lock-in method and correlation with reference spectra. Preliminary measurements of an admixture containing a trace amount of neon in deuterium show better than a factor of 20 improvement in sensitivity over conventional techniques. This can be further improved by correlating the relative intensities of multiple lines to sets of reference spectra.

Brooks, N.H.; Jensen, T.H. [General Atomics, San Diego, CA (United States); Colchin, R.J.; Maingi, R.; Wade, M.R. [Oak Ridge National Lab., TN (United States); Finkenthal, D.F. [Palomar Coll. (United States); Naumenko, N. [Inst. for Atomic and Molecular Physics (Japan); Tugarinov, S. [TRINITI (United States)

1998-07-01T23:59:59.000Z

273

A compact multichannel spectrometer for Thomson scattering  

Science Conference Proceedings (OSTI)

The availability of high-efficiency volume phase holographic (VPH) gratings and intensified CCD (ICCD) cameras have motivated a simplified, compact spectrometer for Thomson scattering detection. Measurements of T{sub e} 100 eV by a 2072 l/mm VPH grating. The spectrometer uses a fast-gated ({approx}2 ns) ICCD camera for detection. A Gen III image intensifier provides {approx}45% quantum efficiency in the visible region. The total read noise of the image is reduced by on-chip binning of the CCD to match the 8 spatial channels and the 10 spectral bins on the camera. Three spectrometers provide a minimum of 12 spatial channels and 12 channels for background subtraction.

Schoenbeck, N. L.; Schlossberg, D. J.; Dowd, A. S.; Fonck, R. J.; Winz, G. R. [Department of Engineering Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States)

2012-10-15T23:59:59.000Z

274

Model simulations of the first aerosol indirect effect and comparison of cloud susceptibility fo satellite measurements  

DOE Green Energy (OSTI)

Present-day global anthropogenic emissions contribute more than half of the mass in submicron particles primarily due to sulfate and carbonaceous aerosol components derived from fossil fuel combustion and biomass burning. These anthropogenic aerosols modify the microphysics of clouds by serving as cloud condensation nuclei (CCN) and enhance the reflectivity of low-level water clouds, leading to a cooling effect on climate (the Twomey effect or first indirect effect). The magnitude of the first aerosol indirect effect is associated with cloud frequency as well as a quantity representing the sensitivity of cloud albedo to changes in cloud drop number concentration. This quantity is referred to as cloud susceptibility [Twomey, 1991]. Analysis of satellite measurements demonstrates that marine stratus clouds are likely to be of higher susceptibility than continental clouds because of their lower number concentrations of cloud drops [Platnick and Twomey, 1994]. Here, we use an improved version of the fully coupled climate/chemistry model [Chuang et al., 1997] to calculate the global concentrations Of sulfate, dust, sea salt, and carbonaceous aerosols (biomass smoke and fossil fuel organic matter and black carbon). We investigated the impact of anthropogenic aerosols on cloud susceptibility and calculated the associated changes of shortwave radiative fluxes at the top of the atmosphere. We also examined the correspondence between the model simulation of cloud susceptibility and that inferred from satellite measurements to test whether our simulated aerosol concentrations and aerosol/cloud interactions give a faithful representation of these features.

Chuang, C; Penner, J E; Kawamoto, K

2002-03-08T23:59:59.000Z

275

Soft ionization of thermally evaporated hypergolic ionic liquid aerosols  

Science Conference Proceedings (OSTI)

Isolated ion pairs of a conventional ionic liquid, 1-Ethyl-3-Methyl-Imidazolium Bis(trifluoromethylsulfonyl)imide ([Emim+][Tf2N?]), and a reactive hypergolic ionic liquid, 1-Butyl-3-Methyl-Imidazolium Dicyanamide ([Bmim+][Dca?]), are generated by vaporizing ionic liquid submicron aerosol particles for the first time; the vaporized species are investigated by dissociative ionization with tunable vacuum ultraviolet (VUV) light, exhibiting clear intact cations, Emim+ and Bmim+, presumably originating from intact ion pairs. Mass spectra of ion pair vapor from an effusive source of the hypergolic ionic liquid show substantial reactive decomposition due to the internal energy of the molecules emanating from the source. Photoionization efficiency curves in the near threshold ionization region of isolated ion pairs of [Emim+][Tf2N?]ionic liquid vapor are compared for an aerosol source and an effusive source, revealing changes in the appearance energy due to the amount of internal energy in the ion pairs. The aerosol source has a shift to higher threshold energy (~;;0.3 eV), attributed to reduced internal energy of the isolated ion pairs. The method of ionic liquid submicron aerosol particle vaporization, for reactive ionic liquids such as hypergolic species, is a convenient, thermally ?cooler? source of isolated intact ion pairs in the gas phase compared to effusive sources.

University of California; ERC, Incorporated, Edwards Air Force Base; Air Force Research Laboratory, Edwards Air Force Base; National Synchrotron Radiation Research Center (NSRRC); Institute of Chemistry, Hebrew University; Koh, Christine J.; Liu, Chen-Lin; Harmon, Christopher W.; Strasser, Daniel; Golan, Amir; Kostko, Oleg; Chambreau, Steven D.; Vaghjiani, Ghanshyam L.; Leone, Stephen R.

2011-07-19T23:59:59.000Z

276

Direct and semi-direct aerosol effects of Southern African1 biomass burning aerosol2  

E-Print Network (OSTI)

1 Direct and semi-direct aerosol effects of Southern African1 biomass burning aerosol2 Naoko effects of biomass burning aerosols from Southern African fires9 during July-October are investigated region the overall TOA radiative effect from the23 biomass burning aerosols is almost zero due

Wood, Robert

277

ARM - Field Campaign - Fall 1997 Aerosol IOP  

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

Aerosol IOP Aerosol IOP Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Fall 1997 Aerosol IOP 1997.09.15 - 1997.10.05 Lead Scientist : Stephen Schwartz For data sets, see below. Summary The Aerosol IOP was highlighted by the Gulfstream-1 aircraft flying clear-sky aerosol missions over the Central Facility to study the effect of aerosol loading on clear sky radiation fields, with weather particularly favorable for these flights during the first and third weeks of the IOP. A secondary but important goal of this IOP was to fly cloudy-sky missions over the Central Facility to study the effect of aerosol loading on cloud microphysics, and the effect of the microphysics on cloud optical properties. The Gulfstream obtained aerosol data in support of some of the

278

Volcanoes and Climate Effects of Aerosols  

E-Print Network (OSTI)

CONTENTS 8.1 Importance of volcanoes, natural aerosols, and anthropogenic aerosols 341 8.2 Major scientific questions and hypotheses 342 8.2.1 Stratospheric volcanic aerosols and climate 342 8.2.1.1 Source gases for stratospheric aerosols 342 8.2.1.2 Explosiveness and plume history during individual eruptions 343 8.2.1.3 Frequency of eruptions, tectonic setting, rock/ash vs. SO 2 343 8.2.1.4 Gas-to-particle conversion and removal mechanisms 343 8.2.1.5 Radiative properties and climatic effects of stratospheric aerosols 345 8.2.1.6 Needed satellite and in situ measurements 347 8.2.1.6.1 Global observations of stratospheric aerosol optical properties 347 8.2.1.6.2 Lidar measurements of aerosols 347 8.2.2 Volcanic aerosols and stratospheric ozone depletion 349 8.2.3 Climatic effects of t

Hartmann And Mouginis-Mark; Volcanoes; D. L. Hartmann; P. Mouginis-mark; G. J. Bluth; J. A. Coakley; J. Crisp; R. E. Dickinson; P. W. Francis; J. E. Hansen; P. V. Hobbs; B. L. Isacks; Y. J. Kaufman; M. D. King; W. I. Rose; S. Self; L. D. Travis

1999-01-01T23:59:59.000Z

279

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

280

Indirect and Semi-direct Aerosol Campaign  

Science Conference Proceedings (OSTI)

A comprehensive dataset of microphysical and radiative properties of aerosols and clouds in the boundary layer in the vicinity of Barrow, Alaska, was collected in April 2008 during the Indirect and Semi-Direct Aerosol Campaign (ISDAC). ISDAC's ...

Greg M. McFarquhar; Steven Ghan; Johannes Verlinde; Alexei Korolev; J. Walter Strapp; Beat Schmid; Jason M. Tomlinson; Mengistu Wolde; Sarah D. Brooks; Dan Cziczo; Manvendra K. Dubey; Jiwen Fan; Connor Flynn; Ismail Gultepe; John Hubbe; Mary K. Gilles; Alexander Laskin; Paul Lawson; W. Richard Leaitch; Peter Liu; Xiaohong Liu; Dan Lubin; Claudio Mazzoleni; Ann-Marie Macdonald; Ryan C. Moffet; Hugh Morrison; Mikhail Ovchinnikov; Matthew D. Shupe; David D. Turner; Shaocheng Xie; Alla Zelenyuk; Kenny Bae; Matt Freer; Andrew Glen

2011-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol mass spectrometer" 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

New Chemical Aerosol Characterization Methods- Examples Using Agricultural and Urban Airborne Particulate Matter  

E-Print Network (OSTI)

This study explored different chemical characterization methods of agricultural and urban airborne particulate matter. Three different field campaigns are discussed. For the agricultural aerosols, measurement of the chemical composition of size-resolved agricultural aerosols collected from a ground site at the nominally downwind and upwind edge of a feedlot in West Texas were reported. High volume cascade impactor samplers were used for the collection of the particles, and two major analytical methods were applied to characterize different components of the aerosols, ion chromatography (IC ) was used to measure ionic composition with the main targets being ammonium (NH4 ), nitrate (NO3 -), and sulfate (SO4 2-), direct thermal desorption gas chromatography-mass spectrometry/flame ionization detection (GC-MS/FID) methodology was used to identify and quantify organic compounds in the aerosol particles. For the urban aerosols, I report the measurement of mass, and the chemical composition of size-resolved aerosols collected from two different locations in Houston, analyzed by the thermal desorption GC-MS/FID method. The investigation of single particle composition using RM is reported as well: RM and chemical mapping techniques have been applied for the qualitative analysis of components in the samples of air particulate matter collected in downtown Houston.

Zhou, Lijun

2010-08-01T23:59:59.000Z

282

Observations of Secondary Organic Aerosol Production and Soot Aging under Atmospheric Conditions Using a Novel Environmental Aerosol Chamber  

E-Print Network (OSTI)

Secondary organic aerosols (SOA) comprise a substantial fraction of the total global aerosol budget. While laboratory studies involving smog chambers have advanced our understanding of the formation mechanisms responsible for SOA, our knowledge of the processes leading to SOA production under ambient gaseous and particulate concentrations as well as the impact these aerosol types have on climate is poorly understood. Although the majority of atmospheric aerosols scatter radiation either directly or indirectly by serving as cloud condensation nuclei, soot is thought to have a significant warming effect through absorption. Like inorganic salts, soot may undergo atmospheric transformation through the vapor condensation of non-volatile gaseous species which will alter both its chemical and physical properties. Typical smog chamber studies investigating the formation and growth of SOA as well as the soot aging process are temporally limited by the initial gaseous concentrations injected into the chamber environment. Furthermore, data interpretation from such experiments is generally restricted to the singular gaseous species under investigation. This dissertation discusses the use of a new aerosol chamber designed to study the formation and growth of SOA and soot aging under atmospherically relevant conditions. The Ambient Aerosol Chamber for Evolution Studies (AACES) was deployed at three field sites where size and hygroscopic growth factor (HGF) of ammonium sulfate seed particles was monitored over time to examine the formation and growth of SOA. Similar studies investigating the soot aging process were also conducted in Houston, TX. It is shown that during the ambient growth of ammonium sulfate seed particles, as particle size increases, hygroscopic growth factors decrease considerably resulting in a significant organic mass fraction in the particle phase concluding an experiment. Observations of soot aging show an increase in measured size, HGF, mass and single scattering albedo. Ambient growth rate comparisons with chamber growth yielded similar trends verifying the use of AACES to study aerosol aging. Based on the results from this study, it is recommended that AACES be employed in future studies involving the production and growth of SOA and soot aging under ambient conditions in order to bridge the gaps in our current scientific knowledge.

Glen, Crystal

2010-12-01T23:59:59.000Z

283

Single particle characterization, source apportionment, and aging effects of ambient aerosols in Southern California  

E-Print Network (OSTI)

detection efficiencies of aerosol time of flight masscomposition of ambient aerosol particles. Environmentalsize dependent response of aerosol counters, Atmospheric

Shields, Laura Grace

2008-01-01T23:59:59.000Z

284

Inter-Comparison and Synergy Between the Two Long-Term Gloval Aerosol Products Derived from AVHRR and TOMS  

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

Inter-Comparison and Synergy Between the Inter-Comparison and Synergy Between the Two Long-Term Global Aerosol Products Derived from AVHRR and TOMS M.-J. Jeong and Z. Li Department of Meteorology University of Maryland College Park, Maryland D. A. Chu and S.-C. Tsay National Aeronautics and Space Administration Goddard Flight Center Greenbelt, Maryland Introduction Eighteen years of satellite-based monthly aerosol products have been derived from the advanced very high resolution radiometer (AVHRR) and total ozone mapping experiment spectrometer (TOMS) sensors. The two products differ in many regards rendering a great potential for developing an integrated product for climate studies. Presented here are some preliminary results of inter-comparison and synergy analyses. Global Aerosol Climatology

285

ATI TDA 5A aerosol generator evaluation  

SciTech Connect

Oil based aerosol ``Smoke`` commonly used for testing the efficiency and penetration of High Efficiency Particulate Air filters (HEPA) and HEPA systems can produce flammability hazards that may not have been previously considered. A combustion incident involving an aerosol generator has caused an investigation into the hazards of the aerosol used to test HEPA systems at Hanford.

Gilles, D.A.

1998-07-27T23:59:59.000Z

286

ARM - Measurement - Aerosol backscattered radiation  

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

backscattered radiation backscattered radiation ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Aerosol backscattered radiation The scattering of radiant energy into the hemisphere of space bounded by a plane normal to the direction of the incident radiation and lying on the same side as the incident ray. Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments AOS : Aerosol Observing System MPL : Micropulse Lidar NEPHELOMETER : Nephelometer

287

EMSL: Capabilities: Mass Spectrometry  

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

Five linear ion traps (one with ETD) Three triple-quadrupole spectrometers Three ion mobility spectrometry (IMS) - time-of-flight (TOF) spectrometers Seventeen custom HPLC,...

288

Evaluating WRF-Chem multi-scale model in simulating aerosol radiative properties over the tropics – A case study over India  

Science Conference Proceedings (OSTI)

We utilized WRF-Chem multi-scale model to simulate the regional distribution of aerosols, optical properties and its effect on radiation over India for a winter month. The model is evaluated using measurements obtained from upper-air soundings, AERONET sun photometers, various satellite instruments, and pyranometers operated by the Indian Meteorological Department. The simulated downward shortwave flux was overestimated when the effect of aerosols on radiation and clouds was neglected. Downward shortwave radiation from a simulation that included aerosol-radiation interaction processes was 5 to 25 Wm{sup -2} closer to the observations, while a simulation that included aerosol-cloud interaction processes were another 1 to 20 Wm{sup -2} closer to the observations. For the few observations available, the model usually underestimated particulate concentration. This is likely due to turbulent mixing, transport errors and the lack of secondary organic aerosol treatment in the model. The model efficiently captured the broad regional hotspots such as high aerosol optical depth over Indo-Gangetic basin as well as the northwestern and southern part of India. The regional distribution of aerosol optical depth compares well with AVHRR aerosol optical depth and the TOMS aerosol index. The magnitude and wavelength-dependence of simulated aerosol optical depth was also similar to the AERONET observations across India. Differences in surface shortwave radiation between simulations that included and neglected aerosol-radiation interactions were as high as -25 Wm{sup -2}, while differences in surface shortwave radiation between simulations that included and neglect aerosol-radiation-cloud interactions were as high as -30 Wm{sup -2}. The spatial variations of these differences were also compared with AVHRR observation. This study suggests that the model is able to qualitatively simulate the impact of aerosols on radiation over India; however, additional measurements of particulate mass and composition are needed to fully evaluate whether the aerosol precursor emissions are adequate when simulating radiative forcing in the region.

Seethala, C.; Pandithurai, G.; Fast, Jerome D.; Polade, Suraj D.; Reddy, M. S.; Peckham, Steven E.

2012-01-24T23:59:59.000Z

289

Secondary organic aerosol from ozone-initiated reactions with terpene-rich household products  

E-Print Network (OSTI)

analysis of competition between aerosol particle removal andof secondary organic aerosol. Part I: ?-pinene/ozone system.data when measuring ambient aerosol. Aerosol Science and

Coleman, Beverly K.

2008-01-01T23:59:59.000Z

290

Scanning Transmission X-ray Microscopy: Applications in Atmospheric Aerosol Research  

E-Print Network (OSTI)

in secondary organic aerosol. Environ. Sci. Technol. 41 ,particles from an urban aerosol. Environ. Sci. Technol. 26 ,carbonaceous atmospheric aerosols. Journal of Aerosol

Moffet, Ryan C.

2011-01-01T23:59:59.000Z

291

Real time infrared aerosol analyzer  

DOE Patents (OSTI)

Apparatus for analyzing aerosols in essentially real time includes a virtual impactor which separates coarse particles from fine and ultrafine particles in an aerosol sample. The coarse and ultrafine particles are captured in PTFE filters, and the fine particles impact onto an internal light reflection element. The composition and quantity of the particles on the PTFE filter and on the internal reflection element are measured by alternately passing infrared light through the filter and the internal light reflection element, and analyzing the light through infrared spectrophotometry to identify the particles in the sample.

Johnson, Stanley A. (Countryside, IL); Reedy, Gerald T. (Bourbonnais, IL); Kumar, Romesh (Naperville, IL)

1990-01-01T23:59:59.000Z

292

Modeling aerosol growth by aqueous chemistry in nonprecipitating stratiform cloud  

SciTech Connect

A new microphysics module based on a two-dimensional (2D) joint size distribution function representing both interstitial and cloud particles is developed and applied to studying aerosol processing in non-precipitating stratocumulus clouds. The module is implemented in a three-dimensional dynamical framework of a large-eddy simulation (LES) model and in a trajectory ensemble model (TEM). Both models are used to study the modification of sulfate aerosol by the activation - aqueous chemistry - resuspension cycle in shallow marine stratocumulus clouds. The effect of particle mixing and different size-distribution representations on modeled aerosol processing are studied in a comparison of the LES and TEM simulations with the identical microphysics treatment exposes and a comparison of TEM simulations with a 2D fixed and moving bin microphysics. Particle mixing which is represented in LES and neglected in the TEM leads to the mean relative per particle dry mass change in the TEM simulations being about 30% lower than in analogous subsample of LES domain. Particles in the final LES spectrum are mixed in from different “parcels”, some of which have experienced longer in-cloud residence times than the TEM parcels, all of which originated in the subcloud layer, have. The mean relative per particle dry mass change differs by 14% between TEM simulations with fixed and moving bin microphysics. Finally, the TEM model with the moving bin microphysics is used to evaluate assumptions about liquid water mass partitioning among activated cloud condensation nuclei (CCN) of different dry sizes. These assumptions are used in large-scale models to map the bulk aqueous chemistry sulfate production, which is largely proportional to the liquid water mass, to the changes in aerosol size distribution. It is shown that the commonly used assumptions that the droplet mass is independent of CCN size or that the droplet mass is proportional to the CCN size to the third power do not perform well in the considered case. The explicitly predicted water partitioning indicates that the mean mass of droplets participating in the models aqueous chemistry calculations is proportional to the dry CCN size.

Ovchinnikov, Mikhail; Easter, Richard C.

2010-07-29T23:59:59.000Z

293

Developing Fieldable Systems for Chemical Sensing Using Field Asymmetric Ion Mobility Spectrometry and Mass Spectrometry  

SciTech Connect

Currently, there is an urgent need for field-rugged and field-programmable sensor systems that provide highly selective, universal monitoring of vapors and aerosols at detectable levels from persons or areas involved with illicit chemical/biological/explosives (CBE) production. These devices must be portable, low cost, robust, and provide accurate measurements to avoid both false positive and negative results. Furthermore, the information provided by the devices must be received in a timely manner so that informed decisions can be immediately made and the appropriate actions taken. Two technologies that are unparalleled in their sensitivity, selectivity, and trace-level detection capabilities are field asymmetric ion mobility spectrometry (FAIMS) and mass spectrometry. Here, we will show progress that has been made toward developing fieldable FAIMS systems and mass spectrometers. Working in collaboration with Sionex Corporation, the microDMx detector was equipped with a continuous air sampling system to develop selective methods for the analysis of compounds of interest. A microdiaphragm pump (KNF Neuberger, Inc.) is used to pull in gas-phase analytes directly from the air for separation and detection with the FAIMS system. The FAIMS evaluation platform (SVAC) unit currently measures 9.8-inch x 4.6-inch x 3.2-inch, weighs 3.1 lb, and utilizes a {sup 63}Ni source to ionize incoming compounds. Analytes entering the unit are separated and identified by their characteristic response to the compensation voltage (V{sub c}) at a given rf field strength (V{sub rf}). This response has been observed to be unique for a wide range of substances studied. If additional verification were required or a targeted analyte present in a complex chemical matrix, a FAIMS unit equipped with a fast gas chromatography column has been evaluated. The unit combines the separation capabilities of gas chromatography with the selectivity of FAIMS. It measures 9.5-inch x 5.25-inch x 3.5-inch, weighs 3.8 lb, and uses a 10.6 eV photoionization source. Analytes are identified both by their elution time from the column and by the characteristic response in the FAIMS spectrum. Analysis times required to obtain results for most analytes examined are less than three minutes. A fieldable mass spectrometer system is also being developed that includes sampling, ionization, mass selection and detection, vacuum technology, and analytical methodology with remote data transmission. Multiple methods for mass selection are being explored, including both Penning and Paul type ion traps as well as a quadrupole system to determine which is best suited for a portable mass spectrometer. Several ionization sources and ion counting methods will also be evaluated to establish their effectiveness with each system. The intended result of this project is a handheld mass spectrometer system capable of field deployment for the detection and identification of a wide range of gas-phase CBE species.

Kevin Kyle, Stephan Weeks, R. Trainham

2008-03-01T23:59:59.000Z

294

Model for Simulating Aerosol Interactions and Chemistry (MOSAIC)  

SciTech Connect

This paper describes the development and evaluation of a new Model for Simulating Aerosol Interactions and Chemistry (MOSAIC), with a special focus on addressing the long-standing issues associated with solving the dynamic partitioning of semi-volatile inorganic gases (HNO3, HCl, and NH3) to size-distributed atmospheric aerosol particles. The coupled ordinary differential equations (ODE) for dynamic gas-particle mass transfer are extremely stiff, and the available numerical techniques are either too expensive or produce oscillatory and/or inaccurate steady-state solutions. These limitations are overcome in MOSAIC, which couples an accurate and computationally efficient thermodynamic module [Zaveri et al., 2005a,b] with a new dynamic gas-particle partitioning module described here. The algorithm involves time-split integrations of non-volatile and semi-volatile species, and a new concept of “dynamic pH” and an adaptive time-stepping scheme hold the key to smooth, accurate, and efficient solutions over the entire relative humidity range. MOSAIC is found to be in excellent agreement with a benchmark version of the model that uses LSODES (a Gear solver) for rigorously integrating the stiff ODEs. The steady-state MOSAIC results for monodisperse aerosol test cases are also in excellent agreement with those obtained with the benchmark equilibrium model AIM. MOSAIC is also evaluated within a 3-D model, and the average CPU speed is estimated to be over 100 times faster than the dynamic aerosol model MADM [Pilinis et al., 2000]. These results suggest that MOSAIC is highly attractive for use in 3-D aerosol and air quality models in which both accuracy and efficiency are critically important.

Zaveri, Rahul A.; Easter, Richard C.; Fast, Jerome D.; Peters, Len K.

2008-07-03T23:59:59.000Z

295

Total Ozone Mapping Spectrometer (TOMS) Derived Data, Global Earth Coverage (GEC) from NASA's Earth Probe Satellite  

DOE Data Explorer (OSTI)

This is data from an external datastream processed through the ARM External Data Center (XDC) at Brookhaven National Laboratory. The XDC identifies sources and acquires data, called "external data", to augment the data being generated within the ARM program. The external data acquired are usually converted from native format to either netCDF or HDF formats. The GEC collection contains global data derived from the Total Ozone Mapping Spectrometer (TOMS) instrument on the Earth Probe satellite, consisting of daily values of aerosol index, ozone and reflectivity remapped into a regular 1x1.25 deg grid. Data are available from July 25, 1996 - December 31, 2005, but have been updated or replaced as of September 2007. See the explanation on the ARM web site at http://www.arm.gov/xds/static/toms.stm and the information at the NASA/TOMS web site: http://toms.gsfc.nasa.gov/ (Registration required)

296

DISK CHOPPER TIME-OF-FLIGHT SPECTROMETER (DCS)  

Science Conference Proceedings (OSTI)

... The Primary Spectrometer High energy neutrons and gammas ... steradians and arranged in three banks: The middle bank detector scattering ...

297

Passive Millimeter-Wave Spectrometer for Remote Chemical Detection  

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

Passive Millimeter-Wave Spectrometer for Remote Chemical Detection Multimedia Nuclear Systems Analysis Engineering Analysis Nonproliferation and National Security Detection &...

298

Coupling Aerosol-Cloud-Radiative Processes in the WRF-Chem Model: Investigating the Radiative Impact of Elevated Point Sources  

Science Conference Proceedings (OSTI)

The local and regional influence of elevated point sources on summertime aerosol forcing and cloud-aerosol interactions in northeastern North America was investigated using the WRF-Chem community model. The direct effects of aerosols on incoming solar radiation were simulated using existing modules to relate aerosol sizes and chemical composition to aerosol optical properties. Indirect effects were simulated by adding a prognostic treatment of cloud droplet number and adding modules that activate aerosol particles to form cloud droplets, simulate aqueous phase chemistry, and tie a two-moment treatment of cloud water (cloud water mass and cloud droplet number) to an existing radiation scheme. Fully interactive feedbacks thus were created within the modified model, with aerosols affecting cloud droplet number and cloud radiative properties, and clouds altering aerosol size and composition via aqueous processes, wet scavenging, and gas-phase-related photolytic processes. Comparisons of a baseline simulation with observations show that the model captured the general temporal cycle of aerosol optical depths (AODs) and produced clouds of comparable thickness to observations at approximately the proper times and places. The model slightly overpredicted SO2 mixing ratios and PM2.5 mass, but reproduced the range of observed SO2 to sulfate aerosol ratios, suggesting that atmospheric oxidation processes leading to aerosol sulfate formation are captured in the model. The baseline simulation was compared to a sensitivity simulation in which all emissions at model levels above the surface layer were set to zero, thus removing stack emissions. Instantaneous, site-specific differences for aerosol and cloud related properties between the two simulations could be quite large, as removing above-surface emission sources influenced when and where clouds formed within the modeling domain. When summed spatially over the finest resolution model domain (the extent of which corresponds to the typical size of a single GCM grid cell) and temporally over a three day analysis period, total rainfall in the sensitivity simulation increased by 31% over that in the baseline simulation. Fewer optically thin clouds, arbitrarily defined as a cloud exhibiting an optical depth less than 1, formed in the sensitivity simulation. Domain-averaged AODs dropped from 0.46 in the baseline simulation to 0.38 in the sensitivity simulation. The overall net effect of additional aerosols attributable to primary particulates and aerosol precursors from point source emissions above the surface was a domain-averaged reduction of 5 W m-2 in mean daytime downwelling shortwave radiation.

Chapman, Elaine G.; Gustafson, William I.; Easter, Richard C.; Barnard, James C.; Ghan, Steven J.; Pekour, Mikhail S.; Fast, Jerome D.

2009-02-01T23:59:59.000Z

299

Evaluation of Empirical Aerosol Correlations  

Science Conference Proceedings (OSTI)

This study examined the adequacy of novel scaling and correlation methods used to analyze aerosol behavior in versions 2.0 and 3.0 of the MAAP computer code. The results show that the MAAP 2.0 method suffers from inaccurate scaling. The method used in MAAP 3.0 is theoretically superior and more consistent with experimental data.

1986-12-17T23:59:59.000Z

300

Single event mass spectrometry  

DOE Patents (OSTI)

A means and method for single event time of flight mass spectrometry for analysis of specimen materials. The method of the invention includes pulsing an ion source imposing at least one pulsed ion onto the specimen to produce a corresponding emission of at least one electrically charged particle. The emitted particle is then dissociated into a charged ion component and an uncharged neutral component. The ion and neutral components are then detected. The time of flight of the components are recorded and can be used to analyze the predecessor of the components, and therefore the specimen material. When more than one ion particle is emitted from the specimen per single ion impact, the single event time of flight mass spectrometer described here furnis This invention was made with Government support under Contract No. W-7405-ENG82 awarded by the Department of Energy. The Government has certain rights in the invention.

Conzemius, Robert J. (Ames, IA)

1990-01-16T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol mass spectrometer" 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

Chemical Characterization of Aerosols on the East Coast of the United States Using Aircraft and Ground-Based Stations during the CLAMS Experiment  

Science Conference Proceedings (OSTI)

The Chesapeake Lighthouse and Aircraft Measurements for Satellites (CLAMS) experiment was carried out off the central East Coast of the United States in July 2001. During CLAMS, aerosol particle mass was measured at two ground stations and on the ...

Andréa Dde Almeida Castanho; Paulo Artaxo; J. Vanderlei Martins; Peter V. Hobbs; Lorraine Remer; Marcia Yamasoe; Peter R. Colarco

2005-04-01T23:59:59.000Z

302

Compact imaging spectrometer utilizing immersed gratings  

DOE Patents (OSTI)

A compact imaging spectrometer with an immersive diffraction grating that compensates optical distortions. The imaging spectrometer comprises an entrance slit for transmitting light, means for receiving the light and directing the light, an immersion grating, and a detector array. The entrance slit, the means for receiving the light, the immersion grating, and the detector array are positioned wherein the entrance slit transmits light to the means for receiving the light and the means for receiving the light directs the light to the immersion grating and the immersion grating receives the light and directs the light to the means for receiving the light, and the means for receiving the light directs the light to the detector array.

Chrisp, Michael P. (Danville, CA); Lerner, Scott A. (Corvallis, OR); Kuzmenko, Paul J. (Livermore, CA); Bennett, Charles L. (Livermore, CA)

2007-07-03T23:59:59.000Z

303

Associated Particle Tagging (APT) in Magnetic Spectrometers  

SciTech Connect

Summary In Brief The Associated Particle Tagging (APT) project, a collaboration of Pacific Northwest National Laboratory (PNNL), Idaho National Laboratory (INL) and the Idaho State University (ISU)/Idaho Accelerator Center (IAC), has completed an exploratory study to assess the role of magnetic spectrometers as the linchpin technology in next-generation tagged-neutron and tagged-photon active interrogation (AI). The computational study considered two principle concepts: (1) the application of a solenoidal alpha-particle spectrometer to a next-generation, large-emittance neutron generator for use in the associated particle imaging technique, and (2) the application of tagged photon beams to the detection of fissile material via active interrogation. In both cases, a magnetic spectrometer momentum-analyzes charged particles (in the neutron case, alpha particles accompanying neutron generation in the D-T reaction; in the tagged photon case, post-bremsstrahlung electrons) to define kinematic properties of the relevant neutral interrogation probe particle (i.e. neutron or photon). The main conclusions of the study can be briefly summarized as follows: Neutron generator: • For the solenoidal spectrometer concept, magnetic field strengths of order 1 Tesla or greater are required to keep the transverse size of the spectrometer smaller than 1 meter. The notional magnetic spectrometer design evaluated in this feasibility study uses a 5-T magnetic field and a borehole radius of 18 cm. • The design shows a potential for 4.5 Sr tagged neutron solid angle, a factor of 4.5 larger than achievable with current API neutron-generator designs. • The potential angular resolution for such a tagged neutron beam can be less than 0.5o for modest Si-detector position resolution (3 mm). Further improvement in angular resolution can be made by using Si-detectors with better position resolution. • The report documents several features of a notional generator design incorporating the alpha-particle spectrometer concept, and outlines challenges involved in the magnetic field design. Tagged photon interrogation: • We investigated a method for discriminating fissile from benign cargo-material response to an energy-tagged photon beam. The method relies upon coincident detection of the tagged photon and a photoneutron or photofission neutron produced in the target material. The method exploits differences in the shape of the neutron production cross section as a function of incident photon energy in order to discriminate photofission yield from photoneutrons emitted by non-fissile materials. Computational tests of the interrogation method as applied to material composition assay of a simple, multi-layer target suggest that the tagged-photon information facilitates precise (order 1% thickness uncertainty) reconstruction of the constituent thicknesses of fissile (uranium) and high-Z (Pb) constituents of the test targets in a few minutes of photon-beam exposure. We assumed an 18-MeV endpoint tagged photon beam for these simulations. • The report addresses several candidate design and data analysis issues for beamline infrastructure required to produce a tagged photon beam in a notional AI-dedicated facility, including the accelerator and tagging spectrometer.

Jordan, David V.; Baciak, James E.; Stave, Sean C.; Chichester, David; Dale, Daniel; Kim, Yujong; Harmon, Frank

2012-10-16T23:59:59.000Z

304

Time Dispersive Spectrometer Using Digital Switching Means  

DOE Patents (OSTI)

Methods and apparatus are described for time dispersive spectroscopy. In particular, a modulated flow of ionized molecules of a sample are introduced into a drift region of an ion spectrometer. The ions are subsequently detected by an ion detector to produce an ion detection signal. The ion detection signal can be modulated to obtain a signal useful in assaying the chemical constituents of the sample.

Tarver, III, Edward E. (Livermore, CA); Siems, William F. (Spokane, WA)

2004-09-07T23:59:59.000Z

305

Mass spectrometric approaches for chemical characterisation of atmospheric aerosols: critical  

E-Print Network (OSTI)

). He received his M.Sc. degree (physics) in 1991 from the Leningrad Polytechnical Institute, Russia received her M.Sc. degree in physics from the Leningrad Polytechnical Institute (1990) and her Ph.D. degree Professor at the University of California, Irvine. He received his M.Sc. degree in biochemistry from

Nizkorodov, Sergey

306

Simulating Aerosols Using a Chemical Transport Model with Assimilation of Satellite Aerosol Retrievals: Methodology for INDOEX  

E-Print Network (OSTI)

A system for simulating aerosols has been developed using a chemical transport model together with an assimilation of satellite aerosol retrievals. The methodology and model components are described in this paper, and the modeled distribution of aerosols for the Indian Ocean Experiment (INDOEX) is presented by Rasch et al. [this issue]. The system generated aerosol forecasts to guide deployment of ships and aircraft during INDOEX. The system consists of the Model of Atmospheric Transport and Chemistry (MATCH) combined with an assimilation package developed for applications in atmospheric chemistry. MATCH predicts the evolution of sulfate, carbonaceous, and mineral dust aerosols, and it diagnoses the distribution of sea salt aerosols. The model includes a detailed treatment of the sources, chemical transformation, transport, and deposition of the aerosol species. The aerosol forecasts involve a two-stage process. During the assimilation phase the total column aerosol optical depth (AOD) is estimated from the model aerosol fields. The model state is then adjusted to improve the agreement between the simulated AOD and satellite retrievals of AOD. During the subsequent integration phase the aerosol fields are evolved using meteorological fields from an external model. Comparison of the modeled AOD against estimates of the AOD from INDOEX Sun photometer data show that the differences in daily means are #0.03 # 0.06. Although the initial application is limited to the Indian Ocean, the methodology could be extended to derive global aerosol analyses combining in situ and remotely sensed aerosol observations.

William D. Collins; Phillip J. Rasch; Brian E. Eaton; Boris V. Khattatov; Jean-francois Lamarque; C. Zender

2001-01-01T23:59:59.000Z

307

Technical Note: Evaluation of the WRF-Chem "Aerosol Chemical to Aerosol Optical Properties" Module using data from the MILAGRO campaign  

SciTech Connect

A comparison between observed aerosol optical properties from the MILAGRO field campaign, which took place in the Mexico City Metropolitan Area (MCMA) during March 2006, and values simulated by the Weather Research and Forecasting model (WRF-Chem) model, reveals large differences. To help identify the source of the discrepancies, data from the MILAGRO campaign are used to evaluate the "aerosol chemical to aerosol optical properties" module implemented in the full chemistry version of the WRF-Chem model. The evaluation uses measurements of aerosol size distributions and chemical properties obtained at the MILAGRO T1 site. These observations are fed to the module, which makes predictions of various aerosol optical properties, including the scattering coefficient, Bscat; the absorption coefficient, Babs; and the single-scattering albedo, v0; all as a function of time. This simulation is compared with independent measurements obtained from a photoacoustic spectrometer (PAS) at a wavelength of 870 nm. Because of line losses and other factors, only "fine mode" aerosols with aerodynamic diameters less than 2.5 mm are considered here. Over a 10-day period, the simulations of hour-by-hour variations of Bscat are not satisfactory, but simulations of Babs and v0 are considerably better. When averaged over the 10-day period, the computed and observed optical properties agree within the uncertainty limits of the measurements and simulations. Specifically, the observed and calculated values are, respectively: (1) Bscat, 34.1 ± 5.1 Mm-1 versus 30.4 ± 4.3 Mm-1; (2) Babs, 9.7 ± 1.0 Mm-1 versus 11.7 ± 1.5 Mm-1; and (3) v0, 0.78 ± 0.04 and 0.74 ± 0.03. The discrepancies in values of v0 simulated by the full WRF-Chem model thus cannot be attributed to the "aerosol chemistry to optics" module. The discrepancy is more likely due, in part, to poor characterization of emissions near the T1 site, particularly black carbon emissions.

Barnard, James C.; Fast, Jerome D.; Paredes-Miranda, Guadalupe L.; Arnott, W. P.; Laskin, Alexander

2010-08-09T23:59:59.000Z

308

Spectro-Microscopic Measurements of Carbonaceous Aerosol Aging in Central California  

Science Conference Proceedings (OSTI)

Carbonaceous aerosols are responsible for large uncertainties in climate models, degraded visibility, and adverse health effects. The Carbonaceous Aerosols and Radiative Effects Study (CARES) was designed to study carbonaceous aerosols in the natural environment of Central Valley, California, and learn more about their atmospheric formation and aging. This paper presents results from spectro-microscopic measurements of carbonaceous particles collected during CARES at the time of pollution accumulation event (June 27-29, 2010), when in situ measurements indicated an increase in the organic carbon content of aerosols as the Sacramento urban plume aged. Computer controlled scanning electron microscopy coupled with an energy dispersive X-ray detector (CCSEM/EDX) and scanning transmission X-ray microscopy coupled with near edge X-ray absorption spectroscopy (STXM/NEXAFS) were used to probe the chemical composition and morphology of individual particles. It was found that the mass of organic carbon on individual particles increased through condensation of secondary organic aerosol. STXM/NEXAFS indicated that the number fraction of homogenous organic particles lacking inorganic inclusions (greater than ~50 nm diameter) increased with plume age as did the organic mass per particle. Comparison of the CARES spectro-microscopic data set with a similar dataset obtained in Mexico City during the MILAGRO campaign showed that individual particles in Mexico City contained twice as much carbon as those sampled during CARES. The number fraction of soot particles at the Mexico City urban site (30%) was larger than at the CARES urban site (10%) and the most aged samples from CARES contained less carbon-carbon double bonds. Differences between carbonaceous particles in Mexico City and California result from different sources, photochemical conditions, gas phase reactants, and secondary organic aerosol precursors. The detailed results provided by these spectro-microscopic measurements will allow for a comprehensive evaluation of aerosol process models used in climate research.

Moffet, Ryan C.; Rodel, Tobias; Kelly, Stephen T.; Yu, Xiao-Ying; Carroll, Gregory; Fast, Jerome D.; Zaveri, Rahul A.; Laskin, Alexander; Gilles, Mary K.

2013-10-29T23:59:59.000Z

309

Design and Sampling Characteristics of a New Airborne Aerosol Inlet for Aerosol Measurements in Clouds  

Science Conference Proceedings (OSTI)

Design of a new submicron aerosol inlet (SMAI) for airborne sampling of aerosol particles is introduced and its performance characteristics under a range of sampling conditions are presented. Analysis of inlet performance in clear-air and cloud ...

Lucas Craig; Allen Schanot; Arash Moharreri; David C. Rogers; Suresh Dhaniyala

2013-06-01T23:59:59.000Z

310

The Aerosol Modeling Testbed: A Community Tool to Objectively Evaluate Aerosol Process Modules  

Science Conference Proceedings (OSTI)

The current paradigm of developing and testing new aerosol process modules is haphazard and slow. Aerosol modules are often tested for short simulation periods using limited data so that their overall performance over a wide range of ...

Jerome D. Fast; William I. Gustafson Jr.; Elaine G. Chapman; Richard C. Easter; Jeremy P. Rishel; Rahul A. Zaveri; Georg A. Grell; Mary C. Barth

2011-03-01T23:59:59.000Z

311

Another Look at the Influence of Absorbing Aerosols in Drops on Cloud Absorption: Large Aerosols  

Science Conference Proceedings (OSTI)

Since as early as 1969, solar absorbing aerosols inside of cloud drops have been suggested to influence cloud radiative properties. The absorbing aerosols were invoked to help explain two “anomalies”: 1) the maximum visible albedo of thick ...

Carynelisa Erlick; Dana Schlesinger

2008-02-01T23:59:59.000Z

312

Assessment of Aerosol Modes Used in the MODIS Ocean Aerosol Retrieval  

Science Conference Proceedings (OSTI)

Coastal and island Aerosol Robotic Network (AERONET) sites are used to determine characteristic aerosol modes over marine environments. They are compared with the assumed modes used in the operational Moderate Resolution Imaging Spectroradiometer (...

Jiacheng Wang; Qiang Zhao; Shengcheng Cui; Chengjie Zhu

2012-12-01T23:59:59.000Z

313

ARM - PI Product - Direct Aerosol Forcing Uncertainty  

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

ProductsDirect Aerosol Forcing Uncertainty ProductsDirect Aerosol Forcing Uncertainty Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send PI Product : Direct Aerosol Forcing Uncertainty Site(s) NSA SGP TWP General Description Understanding sources of uncertainty in aerosol direct radiative forcing (DRF), the difference in a given radiative flux component with and without aerosol, is essential to quantifying changes in Earth's radiation budget. We examine the uncertainty in DRF due to measurement uncertainty in the quantities on which it depends: aerosol optical depth, single scattering albedo, asymmetry parameter, solar geometry, and surface albedo. Direct radiative forcing at the top of the atmosphere and at the surface as well as sensitivities, the changes in DRF in response to unit changes in

314

ARM - Field Campaign - Two-Column Aerosol Project (TCAP)  

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

govCampaignsTwo-Column Aerosol Project (TCAP) govCampaignsTwo-Column Aerosol Project (TCAP) Campaign Links TCAP website Related Campaigns Two-Column Aerosol Project (TCAP): Field Evaluation of Real-time Cloud OD Sensor TWST 2013.04.15, Scott, AMF Two-Column Aerosol Project (TCAP): Winter Aerosol Effects on Cloud Formation 2013.02.04, Cziczo, AMF Two-Column Aerosol Project (TCAP): CU GMAX-DOAS Deployment 2012.07.15, Volkamer, AMF Two-Column Aerosol Project (TCAP): Aerosol Light Extinction Measurements 2012.07.15, Dubey, AMF Two-Column Aerosol Project (TCAP): Aerial Campaign 2012.07.07, Berg, AAF Two-Column Aerosol Project (TCAP): Aerodynamic Particle Sizer 2012.07.01, Berg, AMF Two-Column Aerosol Project (TCAP): KASPRR Engineering Tests 2012.07.01, Mead, AMF Two-Column Aerosol Project (TCAP): Airborne HSRL and RSP Measurements

315

Using MODIS and AERONET to Determine GCM Aerosol Size  

Science Conference Proceedings (OSTI)

Aerosol size is still a poorly constrained quantity in general circulation models (GCMs). By using the modal radii of the coarse and fine mode retrieved from 103 stations in the Aerosol Robotic Network (AERONET) and the fine mode aerosol optical ...

Glen Lesins; Ulrike Lohmann

2006-04-01T23:59:59.000Z

316

Aerosol Remote Sensing over Clouds Using A-Train Observations  

Science Conference Proceedings (OSTI)

The detection of aerosol above clouds is critical for the estimate of both the aerosol and cloud radiative impacts. In this study, the authors present a new method to retrieve the aerosol properties over clouds that uses the multiangle ...

F. Waquet; J. Riedi; L. C. Labonnote; P. Goloub; B. Cairns; J-L. Deuzé; D. Tanré

2009-08-01T23:59:59.000Z

317

AEROSOL ANALYSIS FOR THE REGIONAL AIR POLLUTION STUDY - FINAL REPORT  

E-Print Network (OSTI)

Beta-Gauge Methods Applied to Aerosol Samples." Submitted toHusar and B.Y.H. Liu. "The Aerosol Size Distribution of LosAngeles Smog." In: Aerosols and Atmospheric Chemistry, G.M.

Jaklevic, J.M.

2010-01-01T23:59:59.000Z

318

Distinguishing Aerosol Impacts on Climate Over the Past Century  

E-Print Network (OSTI)

Table 1. Aerosol Characteristics Species Emissions Burdenc and h), IE (d, i) and BAE (e, f). List of Tables AerosolEmission of trace gases and aerosols from biomass burning,

Koch, Dorothy

2009-01-01T23:59:59.000Z

319

OH-initiated heterogeneous aging of highly oxidized organic aerosol  

E-Print Network (OSTI)

P. ; Jimenez, J. L. Aerosol Science and Technology 2004, 38,A. G. Highly dispersed aerosols; Halsted Press, New York,highly oxidized organic aerosol Sean H. Kessler 1 , Theodora

Kessler, Sean H.

2013-01-01T23:59:59.000Z

320

SPURIOUS SULFATE FORMATION ON COLLECTED AMBIENT AEROSOL SAMPLES  

E-Print Network (OSTI)

FORMATION ON COLLECTED AMBIENT AEROSOL SAMPLES B. W. Loo, R.FORMATION ON COLLECTED AMBIENT AEROSOL SAMPLES Billy W. Lao,ON COLLECTED AMBIENT AEROSOL SAMPLES* _B_il_l~y ___ W_. _L~o

Loo, B.W.

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol mass spectrometer" 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

The CALIPSO Automated Aerosol Classification and Lidar Ratio Selection Algorithm  

Science Conference Proceedings (OSTI)

Descriptions are provided of the aerosol classification algorithms and the extinction-to-backscatter ratio (lidar ratio) selection schemes for the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) aerosol products. One ...

Ali H. Omar; David M. Winker; Mark A. Vaughan; Yongxiang Hu; Charles R. Trepte; Richard A. Ferrare; Kam-Pui Lee; Chris A. Hostetler; Chieko Kittaka; Raymond R. Rogers; Ralph E. Kuehn; Zhaoyan Liu

2009-10-01T23:59:59.000Z

322

Global distribution and climate forcing of marine organic aerosol: 1. Model improvements and evaluation  

Science Conference Proceedings (OSTI)

Marine organic aerosol emissions have been implemented and evaluated within the National Center of Atmospheric Research (NCAR)'s Community Atmosphere Model (CAM5) with the Pacific Northwest National Laboratory's 7-mode Modal Aerosol Module (MAM-7). Emissions of marine primary organic aerosols (POA), phytoplanktonproduced isoprene- and monoterpenes-derived secondary organic aerosols (SOA) and methane sulfonate (MS{sup -}) are shown to affect surface concentrations of organic aerosols in remote marine regions. Global emissions of submicron marine POA is estimated to be 7.9 and 9.4 Tg yr{sup -1}, for the Gantt et al. (2011) and Vignati et al. (2010) emission parameterizations, respectively. Marine sources of SOA and particulate MS{sup -} (containing both sulfur and carbon atoms) contribute an additional 0.2 and 5.1 Tg yr{sup -1}, respectively. Widespread areas over productive waters of the Northern Atlantic, Northern Pacific, and the Southern Ocean show marine-source submicron organic aerosol surface concentrations of 100 ngm{sup -3}, with values up to 400 ngm{sup -3} over biologically productive areas. Comparison of long-term surface observations of water insoluble organic matter (WIOM) with POA concentrations from the two emission parameterizations shows that despite revealed discrepancies (often more than a factor of 2), both Gantt et al. (2011) and Vignati et al. (2010) formulations are able to capture the magnitude of marine organic aerosol concentrations, with the Gantt et al. (2011) parameterization attaining better seasonality. Model simulations show that the mixing state of the marine POA can impact the surface number concentration of cloud condensation nuclei (CCN). The largest increases (up to 20 %) in CCN (at a supersaturation (S) of 0.2 %) number concentration are obtained over biologically productive ocean waters when marine organic aerosol is assumed to be externally mixed with sea-salt. Assuming marine organics are internally-mixed with sea-salt provides diverse results with increases and decreases in the concentration of CCN over different parts of the ocean. The sign of the CCN change due to the addition of marine organics to seasalt aerosol is determined by the relative significance of the increase in mean modal diameter due to addition of mass, and the decrease in particle hygroscopicity due to compositional changes in marine aerosol. Based on emerging evidence for increased CCN concentration over biologically active surface ocean areas/periods, our study suggests that treatment of sea spray in global climate models (GCMs) as an internal mixture of marine organic aerosols and sea-salt will likely lead to an underestimation in CCN number concentration.

Meskhidze, N.; Xu, J.; Gantt, Brett; Zhang, Yang; Nenes, Athanasios; Ghan, Steven J.; Liu, Xiaohong; Easter, Richard C.; Zaveri, Rahul A.

2011-11-23T23:59:59.000Z

323

Assessing regional scale predictions of aerosols, marine stratocumulus, and their interactions during VOCALS-REx using WRF-Chem  

Science Conference Proceedings (OSTI)

This study assesses the ability of the recent chemistry version (v3.3) of the Weather Research and Forecasting (WRF-Chem) model to simulate boundary layer structure, aerosols, stratocumulus clouds, and energy fluxes over the Southeast Pacific Ocean. Measurements from the VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx) and satellite retrievals (i.e., products from the MODerate resolution Imaging Spectroradiometer (MODIS), Clouds and Earth's Radiant Energy System (CERES), and GOES-10) are used for this assessment. The Morrison double-moment microphysics scheme is newly coupled with interactive aerosols in the model. The 31-day (15 October-16 November 2008) WRF-Chem simulation with aerosol-cloud interactions (AERO hereafter) is also compared to a simulation (MET hereafter) with fixed cloud droplet number concentrations in the microphysics scheme and simplified cloud and aerosol treatments in the radiation scheme. The well-simulated aerosol quantities (aerosol number, mass composition and optical properties), and the inclusion of full aerosol-cloud couplings lead to significant improvements in many features of the simulated stratocumulus clouds: cloud optical properties and microphysical properties such as cloud top effective radius, cloud water path, and cloud optical thickness. In addition to accounting for the aerosol direct and semi-direct effects, these improvements feed back to the simulation of boundary-layer characteristics and energy budgets. Particularly, inclusion of interactive aerosols in AERO strengthens the temperature and humidity gradients within the capping inversion layer and lowers the marine boundary layer (MBL) depth by 130 m from that of the MET simulation. These differences are associated with weaker entrainment and stronger mean subsidence at the top of the MBL in AERO. Mean top-of-atmosphere outgoing shortwave fluxes, surface latent heat, and surface downwelling longwave fluxes are in better agreement with observations in AERO, compared to the MET simulation. Nevertheless, biases in some of the simulated meteorological quantities (e.g., MBL temperature and humidity) and aerosol quantities (e.g., underestimations of accumulation mode aerosol number) might affect simulated stratocumulus and energy fluxes over the Southeastern Pacific, and require further investigation. The well-simulated timing and outflow patterns of polluted and clean episodes demonstrate the model's ability to capture daily/synoptic scale variations of aerosol and cloud properties, and suggest that the model is suitable for studying atmospheric processes associated with pollution outflow over the ocean. The overall performance of the regional model in simulating mesoscale clouds and boundary layer properties is encouraging and suggests that reproducing gradients of aerosol and cloud droplet concentrations and coupling cloud-aerosol-radiation processes are important when simulating marine stratocumulus over the Southeast Pacific.

Yang Q.; Lee Y.; Gustafson Jr., W. I.; Fast, J. D.; Wang, H.; Easter, R. C.; Morrison, H.; Chapman, E. G.; Spak, S. N.; Mena-Carrasco, M. A.

2011-12-02T23:59:59.000Z

324

Thermophoresis and its thermal parameters for aerosol collection  

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

Thermophoresis and its thermal parameters for aerosol collection Thermophoresis and its thermal parameters for aerosol collection Title Thermophoresis and its thermal parameters for aerosol collection Publication Type Journal Article Year of Publication 2007 Authors Huang, Zhuo, Michael G. Apte, and Lara A. Gundel Journal U.S. Department of Energy Journal of Undergraduate Research Volume 7 Pagination 37-42 Abstract The particle collection effi ciency of a prototype environmental tobacco smoke (ETS) sampler based on the use of thermophoresis is determined by optimizing the operational voltage that determines its thermal gradient. This sampler's heating element was made of three sets of thermophoretic (TP) wires 25µm in diameter suspended across a channel cut in a printed circuit board and mounted with collection surfaces on both sides. The separation between the heating element and the room temperature collection surface was determined in a numerical simulation based on the Brock-Talbot model. Other thermal parameters of this TP ETS sampler were predicted by the Brock-Talbot model for TP deposition. From the normalized results the optimal collection ratio was expressed in terms of operational voltage and fi lter mass. Prior to the Brock-Talbot model simulation for this sampler, 1.0V was used arbitrarily. The operational voltage was raised

325

Scoping studies: behavior and control of lithium and lithium aerosols  

Science Conference Proceedings (OSTI)

The HEDL scoping studies examining the behavior of lithium and lithium aerosols have been conducted to determine and examine potential safety and environmental issues for postulated accident conditions associated with the use of lithium as a fusion reactor blanket and/or coolant. Liquid lithium reactions with air, nitrogen, carbon dioxide and concretes have been characterized. The effectiveness of various powder extinguishing agents and methods of application were determined for lithium-air reactions. The effectiveness of various lithium aerosol collection methods were determined and the volatilization and transport of radioactive metals potentially associated with lithium-air reactions were evaluated. Liquid lithium atmosphere reactions can be safely controlled under postulated accident conditions, but special handling practices must be provided. Lithium-concrete reactions should be avoided because of the potential production of high temperatures, corrosive environment and hydrogen. Carbon microspheres are effective in extinguishing well established lithium-air reactions for the lithium quantities tested (up to 10 kg). Large mass loading of lithium aerosols can be efficiently collected with conventional air cleaning systems. Potentially radioactive species (cobalt, iron and manganese) will be volatilized in a lithium-air reaction in contact with neutron activated stainless steel.

Jeppson, D.W.

1982-01-01T23:59:59.000Z

326

Hydrolysis of organonitrate functional groups in aerosol particles  

Science Conference Proceedings (OSTI)

Organonitrate (ON) groups are important substituents in secondary organic aerosols. Model simulations and laboratory studies indicate a large fraction of ON groups in aerosol particles, but much lower quantities are observed in the atmosphere. Hydrolysis of ON groups in aerosol particles has been proposed recently. To test this hypothesis, we simulated formation of ON molecules in a reaction chamber under a wide range of relative humidity (0% to 90%). The mass fraction of ON groups (5% to 20% for high-NOx experiments) consistently decreased with increasing relative humidity, which was best explained by hydrolysis of ON groups at a rate of 4 day-1 (lifetime of 6 hours) for reactions under relative humidity greater than 20%. In addition, we found that secondary nitrogen-containing molecules absorb light, with greater absorption under dry and high-NOx conditions. This work provides the first evidence for particle-phase hydrolysis of ON groups, a process that could substantially reduce ON group concentration in the atmosphere.

Liu, Shang; Shilling, John E.; Song, Chen; Hiranuma, Naruki; Zaveri, Rahul A.; Russell, Lynn M.

2012-10-19T23:59:59.000Z

327

Direct and semidirect aerosol effects of southern African biomass burning aerosol  

E-Print Network (OSTI)

Direct and semidirect aerosol effects of southern African biomass burning aerosol Naoko Sakaeda,1 2011; published 21 June 2011. [1] Direct and semidirect radiative effects of biomass burning aerosols static stability. Over the entire region the overall TOA radiative effect from the biomass burning

Wood, Robert

328

Micro Aerosol-based Decontamination System - Available ...  

Search PNNL. PNNL Home; About; Research; Publications; Jobs; News; Contacts; Micro Aerosol-based Decontamination System. Battelle Number(s): 15847. ...

329

Aerosol Retrieval Using Remote-sensed Observations  

E-Print Network (OSTI)

electromagnetic solar radiation. The amount of atmosphericas the amount of solar radiation that aerosols scatter andbased on reflected solar radiation field measurements

Wang, Yueqing

2012-01-01T23:59:59.000Z

330

Composition and Reactions of Atmospheric Aerosol Particles  

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

change. Tiny Specks with Large Effects Most people equate aerosols with hairspray and household cleaning products, but a large portion of these microscopic particles floating...

331

Radiative and climate impacts of absorbing aerosols  

E-Print Network (OSTI)

over the southwest summer monsoon region, Meteorol. Atmos.Absorbing aerosols and summer monsoon evolution over SouthK. M. Kim (2006), Asian summer monsoon anomalies induced by

Zhu, Aihua

2010-01-01T23:59:59.000Z

332

Carbonaceous Aerosol Study Using Advanced Particle Instrumentation  

E-Print Network (OSTI)

range transport of biomass combustion aerosols. Environ.6 6.1 Introduction Biomass combustion emissions contributeparticles from the combustion of biomass fuels. Environ.

Qi, Li

2010-01-01T23:59:59.000Z

333

Coupled aerosol-chemistry-climate twentieth century transient...  

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

Coupled aerosol-chemistry-climate twentieth century transient model investigation: Trends in short-lived species and climate responses Title Coupled aerosol-chemistry-climate...

334

THERMOPHORESIS AND ITS THERMAL PARAMETERS FOR AEROSOL COLLECTION  

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

THERMOPHORESIS AND ITS THERMAL PARAMETERS FOR AEROSOL COLLECTION Title THERMOPHORESIS AND ITS THERMAL PARAMETERS FOR AEROSOL COLLECTION Publication Type Journal Article LBNL Report...

335

Aerosol organic carbon to black carbon ratios: Analysis of published...  

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

Aerosol organic carbon to black carbon ratios: Analysis of published data and implications for climate forcing Title Aerosol organic carbon to black carbon ratios: Analysis of...

336

OLIGOMERIZATION OF LEVOGLUCOSAN IN PROXIES OF BIOMASS BURNING AEROSOLS.  

E-Print Network (OSTI)

??Biomass burning aerosols play an important role in the chemistry and physics of the atmosphere and therefore, affect global climate. Biomass burning aerosols are generally… (more)

Holmes, Bryan J.

337

Evaluating the Direct and Indirect Aerosol Effect on Climate  

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

one of the largest uncertainties in climate forcing studies is the effect of aerosols on the earth-atmosphere system. Aerosols affect the radiation budget under both clear...

338

Aerosol Jet® Material Deposition for High Resolution Printed ...  

Science Conference Proceedings (OSTI)

Abstract Scope, Aerosol Jet printing, is finding wide use in a number of ... The Aerosol Jet systems deposit a wide variety of functional materials onto a wide ...

339

Characterizing the Formation of Secondary Organic Aerosols-Interim...  

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

Characterizing the Formation of Secondary Organic Aerosols-Interim Report. Title Characterizing the Formation of Secondary Organic Aerosols-Interim Report. Publication Type Report...

340

Modeling Corrosion of a Metal under an Aerosol Droplet  

Science Conference Proceedings (OSTI)

Deposition of aerosol droplets produced either by marine or industrial activity on the ... The atmospheric corrosion caused by aerosols is a result of a complex ...

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


341

Raman Lidar Measurements of Aerosols and Water Vapor During the...  

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

Raman Lidar Measurements of Aerosols and Water Vapor During the May 2003 Aerosol IOP R. A. Ferrare National Aeronautics and Space Administration Langley Research Center Hampton,...

342

Factors affecting the indoor concentrations of carbonaceous aerosols...  

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

Factors affecting the indoor concentrations of carbonaceous aerosols of outdoor origin Title Factors affecting the indoor concentrations of carbonaceous aerosols of outdoor origin...

343

The Transformation of Outdoor Ammonium Nitrate Aerosols in the...  

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

The Transformation of Outdoor Ammonium Nitrate Aerosols in the Indoor Environment Title The Transformation of Outdoor Ammonium Nitrate Aerosols in the Indoor Environment...

344

Studies of urban atmospheric aerosols using lidar and sky radiometer.  

E-Print Network (OSTI)

???This thesis discusses the remote sensing of atmospheric aerosols, the corresponding instrumental technology and inversion algorithm. The urban aerosol optical properties in Hong Kong have… (more)

Yang, Xun (??)

2008-01-01T23:59:59.000Z

345

Compact proton spectrometers for measurements of shock  

Science Conference Proceedings (OSTI)

The compact Wedge Range Filter (WRF) proton spectrometer was developed for OMEGA and transferred to the National Ignition Facility (NIF) as a National Ignition Campaign (NIC) diagnostic. The WRF measures the spectrum of protons from D-{sup 3}He reactions in tuning-campaign implosions containing D and {sup 3}He gas; in this work we report on the first proton spectroscopy measurement on the NIF using WRFs. The energy downshift of the 14.7-MeV proton is directly related to the total {rho}R through the plasma stopping power. Additionally, the shock proton yield is measured, which is a metric of the final merged shock strength.

Mackinnon, A; Zylstra, A; Frenje, J A; Seguin, F H; Rosenberg, M J; Rinderknecht, H G; Johnson, M G; Casey, D T; Sinenian, N; Manuel, M; Waugh, C J; Sio, H W; Li, C K; Petrasso, R D; Friedrich, S; Knittel, K; Bionta, R; McKernan, M; Callahan, D; Collins, G; Dewald, E; Doeppner, T; Edwards, M J; Glenzer, S H; Hicks, D; Landen, O L; London, R; Meezan, N B

2012-05-02T23:59:59.000Z

346

Ion mobility spectrometer with virtual aperture grid  

DOE Patents (OSTI)

An ion mobility spectrometer does not require a physical aperture grid to prevent premature ion detector response. The last electrodes adjacent to the ion collector (typically the last four or five) have an electrode pitch that is less than the width of the ion swarm and each of the adjacent electrodes is connected to a source of free charge, thereby providing a virtual aperture grid at the end of the drift region that shields the ion collector from the mirror current of the approaching ion swarm. The virtual aperture grid is less complex in assembly and function and is less sensitive to vibrations than the physical aperture grid.

Pfeifer, Kent B. (Los Lunas, NM); Rumpf, Arthur N. (Albuquerque, NM)

2010-11-23T23:59:59.000Z

347

Lead Slowing Down Spectrometer Status Report  

Science Conference Proceedings (OSTI)

This report documents the progress that has been completed in the first half of FY2012 in the MPACT-funded Lead Slowing Down Spectrometer project. Significant progress has been made on the algorithm development. We have an improve understanding of the experimental responses in LSDS for fuel-related material. The calibration of the ultra-depleted uranium foils was completed, but the results are inconsistent from measurement to measurement. Future work includes developing a conceptual model of an LSDS system to assay plutonium in used fuel, improving agreement between simulations and measurement, design of a thorium fission chamber, and evaluation of additional detector techniques.

Warren, Glen A.; Anderson, Kevin K.; Bonebrake, Eric; Casella, Andrew M.; Danon, Yaron; Devlin, M.; Gavron, Victor A.; Haight, R. C.; Imel, G. R.; Kulisek, Jonathan A.; O'Donnell, J. M.; Weltz, Adam

2012-06-07T23:59:59.000Z

348

What Caused the Lead burn-out in Spectrometer Magnet 2B  

SciTech Connect

The spectrometer solenoids are supposed to be the first magnets installed in the MICE Cooling Channel. The results of the test of Spectrometer Magnet 2B are reported in a previous MICE Note. Magnet 2B was tested with all five coils connected in series. The magnet failed because a lead to coil M2 failed before it could be trained to its full design current of 275 A. First, this report describes the condition of the magnet when the lead failure occurred. The lead that failed was between the cold mass feed-through and the heavy lead that connected to coil M2 and the quench protection diodes. It is believed that the lead failed because the minimum propagation zone (MPZ) length was too short. The quench was probably triggered by lead motion in the field external to the magnet center coil. The effect of heat transfer on quench propagation and MPZ length is discussed. The MPZ length is compared for a number of cases that apply to the spectrometer solenoid 2B as built and as it has been repaired. The required heat transfer coefficient for cryogenic stability and the quench propagation velocity along the leads are compared for various parts of the Magnet leads inside the cold mass cryostat. The effect of the insulation on leads on heat transfer is and stability is discussed.

Green, Michael A

2010-11-29T23:59:59.000Z

349

Electro-optic Phase Grating Streak Spectrometer  

SciTech Connect

The electro-optic phase grating streak spectrometer (EOPGSS) generates a time-resolved spectra equivalent to that obtained with a conventional spectrometer/streak camera combination, but without using a streak camera (by far the more expensive and problematic component of the conventional system). The EOPGSS is based on a phase, rather than an amplitude grating. Further, this grating is fabricated of electro-optic material such as, for example, KD*P, by either etching grooves into an E-O slab, or by depositing lines of the E-O material onto an optical flat. An electric field normal to the grating alters the material’s index of refraction and thus affects a shift (in angle) of the output spectrum. Ramping the voltage streaks the spectrum correspondingly. The streak and dispersion directions are the same, so a second (static, conventional) grating disperses the spectrum in the orthogonal direction to prevent different wavelengths from “overwriting” each other. Because the streaking is done by the grating, the streaked output spectrum is recorded with a time-integrating device, such as a CCD. System model, typical design, and performance expectations will be presented.

Goldin, F. J.

2012-08-02T23:59:59.000Z

350

ORISS Isomer and Isobar Spectrometer and Separator for Study of Exotic Decays  

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

ORISS Isomer ORISS Isomer and Isobar Spectrometer and Separator for Study of Exotic Decays A. Piechaczek for the 2 EMIS 2007 UNIRIB Consortium * The purpose is to provide a nuclear research facility at ORNL for consortium members * Consortium members: 3 EMIS 2007 * Our Deliverable is Science - Nuclear Physics * We do research * We give scientific reports at meetings * We train students * UNIRIB, with ORISE and ORAU, provides a university atmosphere in a national laboratory 4 Motivation to build ORISS - Oak Ridge Isomer/Isobar Spectrometer and Separator: * Decay studies often possible from yield considerations, but limited by background from isobaric/isomeric contamination * Need high resolution separator for background suppression ORISS predicted performance: * High mass resolving power, M/∆M

351

Longwave radiative forcing by aqueous aerosols  

SciTech Connect

Recently, a great deal of interest has been focused on the role of aerosols in climatic change because of their potential cooling impacts due to light scattering. Recent advances in infrared spectroscopy using cylindrical internal reflectance have allowed the longwave absorption of dissolved aerosol species and the associated liquid water to be accurately determined and evaluated. Experimental measurements using these techniques have shown that dissolved sulfate, nitrate, and numerous other aerosol species will act to cause greenhouse effects. Preliminary calculations indicate that the longwave climate forcing (i.e., heating) for sulfate aerosol will be comparable in magnitude to the cooling effect produced by light scattering. However, more detailed modeling will clearly be needed to address the impact of the longwave forcing due to aerosols as a function of atmospheric height and composition. Their work has shown that aerosol composition will be important in determining longwave forcing, while shortwave forcing will be more related to the physical size of the aerosol droplets. On the basis of these studies, it is increasingly apparent that aerosols, fogs, and clouds play a key role in determining the radiative balance of the atmosphere and in controlling regional and global climates.

Gaffney, J.S.; Marley, N.A. [Argonne National Lab., IL (United States). Environmental Research Div.

1995-01-01T23:59:59.000Z

352

Nanograting-based compact vacuum ultraviolet spectrometer and ...  

Nanograting-based compact vacuum ultraviolet spectrometer and beam pro?ler for in situ characterization of high-order harmonic generation light sources

353

The triple axis spectrometer at the new research reactor OPAL ...  

Science Conference Proceedings (OSTI)

... The triple axis spectrometer at the new research reactor OPAL in Australia. ... The TAS will be based on a thermal beam at the reactor face. ...

354

SEQUOIA: the Fine-Resolution Fermi Chopper Spectrometer at SNS...  

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

of novel systems and materials that are currently unknown and complements the other main SNS chopper spectrometer, ARCS. In general, SEQUOIA is the instrument of choice for...

355

Passive Millimeter-Wave Spectrometer for Remote Chemical Detection...  

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

Media format Windows Media Format - Low Bandwidth Passive Millimeter-Wave Spectrometer for Remote Chemical Detection shown in this movie clip. :: Please wait until video loads...

356

Evaluating WRF-Chem aerosol indirect effects in Southeast Pacific marine stratocumulus during VOCALS-REx  

SciTech Connect

We evaluate a regional-scale simulation with the WRF-Chem model for the VAMOS (Variability of the American Monsoon Systems) Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx), which sampled the Southeast Pacific's persistent stratocumulus deck. Evaluation of VOCALS-REx ship-based and three aircraft observations focuses on analyzing how aerosol loading affects marine boundary layer (MBL) dynamics and cloud microphysics. We compare local time series and campaign-averaged longitudinal gradients, and highlight differences in model simulations with (W) and without (NW) wet deposition processes. The higher aerosol loadings in the NW case produce considerable changes in MBL dynamics and cloud microphysics, in accordance with the established conceptual model of aerosol indirect effects. These include increase in cloud albedo, increase in MBL and cloud heights, drizzle suppression, increase in liquid water content, and increase in cloud lifetime. Moreover, better statistical representation of aerosol mass and number concentration improves model fidelity in reproducing observed spatial and temporal variability in cloud properties, including top and base height, droplet concentration, water content, rain rate, optical depth (COD) and liquid water path (LWP). Together, these help to quantify confidence in WRF-Chem's modeled aerosol-cloud interactions, especially in the activation parameterization, while identifying structural and parametric uncertainties including: irreversibility in rain wet removal; overestimation of marine DMS and sea salt emissions, and accelerated aqueous sulfate conversion. Our findings suggest that WRF-Chem simulates marine cloud-aerosol interactions at a level sufficient for applications in forecasting weather and air quality and studying aerosol climate forcing, and may do so with the reliability required for policy analysis.

Saide P. E.; Springston S.; Spak, S. N.; Carmichael, G. R.; Mena-Carrasco, M. A.; Yang, Q.; Howell, S.; Leon, D. C.; Snider, J. R.; Bandy, A. R.; Collett, J. L.; Benedict, K. B.; de Szoeke, S. P.; Hawkins, L. N.; Allen, G.; Crawford, I.; Crosier, J.

2012-03-29T23:59:59.000Z

357

Evaluating WRF-Chem aerosol indirect effects in Southeast Pacific marine stratocumulus during VOCALS-REx  

SciTech Connect

We evaluate a regional-scale simulation with the WRF-Chem model for the VAMOS (Variability of the American Monsoon Systems) Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx), which sampled the Southeast Pacific's persistent stratocumulus deck. Evaluation of VOCALS-REx ship-based and aircraft observations focuses on analyzing how aerosol loading affects marine boundary layer (MBL) dynamics and cloud microphysics. We compare local time series and campaign averaged longitudinal gradients, and highlight differences in model simulations with (W) and without wet (NW) deposition processes. The higher aerosol loadings in the NW case produce considerable changes in MBL dynamics and cloud microphysics, in accordance with the established conceptual model of aerosol indirect effects. These include increase in cloud albedo, increase in MBL and cloud heights, drizzle suppression, increase in liquid water content, and increase in cloud lifetime. Moreover, better statistical representation of aerosol mass and number concentration improves model fidelity in reproducing observed spatial and temporal variability in cloud properties, including top and base height, droplet concentration, water content, rain rate, optical depth (COD) and liquid water path (LWP). Together, these help to quantify confidence in WRF-Chem's modeled aerosol-cloud interactions, while identifying structural and parametric uncertainties including: irreversibility in rain wet removal; overestimation of marine DMS and sea salt emissions and accelerated aqueous sulfate conversion. Our findings suggest that WRF-Chem simulates marine cloud-aerosol interactions at a level sufficient for applications in forecasting weather and air quality and studying aerosol climate forcing, including the reliability required for policy analysis and geo-engineering applications.

Saide, Pablo; Spak, S. N.; Carmichael, Gregory; Mena-Carrasco, M. A.; Yang, Qing; Howell, S. G.; Leon, Dolislager; Snider, Jefferson R.; Bandy, Alan R.; Collett, Jeffrey L.; Benedict, K. B.; de Szoeke, S.; Hawkins, Lisa; Allen, Grant; Crawford, I.; Crosier, J.; Springston, S. R.

2012-03-30T23:59:59.000Z

358

BNL | Mobile Aerosol Observing System (MAOS)  

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

Mobile Aerosol Observing System (MAOS) Mobile Aerosol Observing System (MAOS) The Mobile Aerosol Observing System (MAOS) is a platform and instrument suite for Intensive Operation Periods (IOPs) to conduct in situ measurements of aerosols and their precursors. MAOS is part of the ARM Climate Research Facility. Physically MAOS is contained in two 20' SeaTainers custom adapted to provide a sheltered laboratory environment for operators and instruments even under harsh conditions. The two structures are designated MAOS-A and MAOS-C for Aerosol and Chemistry respectively. Although independent, with separate data systems, inlets and power distribution, the two structures are normally a single operating unit. The two enclosures comprising MAOS are designed for rapid deployment. All components (except for the Radar Wind Profiler) are transported internally

359

The Opposed Migration Aerosol Classifier (OMAC)  

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

The Opposed Migration Aerosol Classifier (OMAC) The Opposed Migration Aerosol Classifier (OMAC) Speaker(s): Harmony Gates Date: February 22, 2007 - 12:00pm Location: 90-4133 Seminar Host/Point of Contact: Melissa Lunden A new differential mobility classifier will be described. The instrument classifies aerosol particles in a channel flow between porous (or screen) electrodes. The aerosol enters the channel parallel to the porous electrodes, while a larger, particle-free cross-flow enters through one of the porous electrode. A potential difference between electrodes causes the charged aerosol particles to migrate upstream against the cross-flow. Only particles whose upward migration velocity balances the cross flow will be transmitted along the path of the classifier. Simulations of the OMAC show that it should give the same resolution at the traditional

360

Interpretation of Secondary Organic Aerosol Formation from Diesel Exhaust Photooxidation in an Environmental Chamber  

Science Conference Proceedings (OSTI)

Secondary organic aerosol (SOA) formation from diesel exhaust in a smog chamber was investigated. Particle volume measurement based on mobility diameter is shown to underestimate SOA formation from diesel exhaust due to the external void space of agglomerate particles, in which case mass-based measurement technique is necessary. Rapid determination of particle effective density as a function of particle mass was performed by an Aerosol Particle Mass analyzer – Scanning Mobility Particle Sizer (APM-SMPS) to obtain particle mass concentration and fractal dimension. Continuous aging of aerosol was observed in terms of atomic ratio (O/C), from 0.05 to 0.25 in 12 hours, underscoring the importance of multi-generational oxidation of low-volatile organic vapors emitted from diesel engine as the significant source of oxygenated SOA. Experimental conditions possibly have strong impacts on physical evolution of diesel particulates in a smog chamber. Higher particle effective densities were observed when raw exhaust was injected into a full bag as opposed to filling a bag with diluted exhaust using an ejector diluter. When longer transfer line was used for injecting diesel exhaust into the smog chamber, rapid particle coagulation was observed, leading to increasing particle volume concentration in dark while its mass concentration is decreasing.

Nakao, Shunsuke; Shrivastava, ManishKumar B.; Nguyen, Anh; Jung, Hee-Jung; Cocker, David R.

2011-04-14T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol mass spectrometer" 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

AEROSOL PARTICLE COLLECTOR DESIGN STUDY  

Science Conference Proceedings (OSTI)

A computational evaluation of a particle collector design was performed to evaluate the behavior of aerosol particles in a fast flowing gas stream. The objective of the work was to improve the collection efficiency of the device while maintaining a minimum specified air throughput, nominal collector size, and minimal power requirements. The impact of a range of parameters was considered subject to constraints on gas flow rate, overall collector dimensions, and power limitations. Potential improvements were identified, some of which have already been implemented. Other more complex changes were identified and are described here for further consideration. In addition, fruitful areas for further study are proposed.

Lee, S; Richard Dimenna, R

2007-09-27T23:59:59.000Z

362

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

363

Toward a Minimal Representation of Aerosols in Climate Models: Description and Evaluation in the Community Atmosphere Model CAM5  

Science Conference Proceedings (OSTI)

A modal aerosol module (MAM) has been developed for the Community Atmosphere Model version 5 (CAM5), the atmospheric component of the Community Earth System Model version 1 (CESM1). MAM is capable of simulating the aerosol size distribution and both internal and external mixing between aerosol components, treating numerous complicated aerosol processes and aerosol physical, chemical and optical properties in a physically based manner. Two MAM versions were developed: a more complete version with seven-lognormal modes (MAM7), and a three-lognormal mode version (MAM3) for the purpose of long-term (decades to centuries) simulations. Major approximations in MAM3 include assuming immediate mixing of primary organic matter (POM) and black carbon (BC) with other aerosol components, merging of the MAM7 fine dust and fine sea salt modes into the accumulation mode, merging of the MAM7 coarse dust and coarse sea salt modes into the single coarse mode, and neglecting the explicit treatment of ammonia and ammonium cycles. Simulated sulfate and secondary organic aerosol (SOA) mass concentrations are remarkably similar between MAM3 and MAM7 as most ({approx}90%) of these aerosol species are in the accumulation mode. Differences of POM and BC concentrations between MAM3 and MAM7 are also small (mostly within 10%) because of the assumed hygroscopic nature of POM, so that freshly emitted POM and BC are wet-removed before mixing internally with soluble aerosol species. Sensitivity tests with the POM assumed to be hydrophobic and with slower aging process increase the POM and BC concentrations, especially at high latitudes (by several times). The mineral dust global burden differs by 10% and sea salt burden by 30-40% between MAM3 and MAM7 mainly due to the different size ranges for dust and sea salt modes and different standard deviations of log-normal size distribution for sea salt modes between MAM3 and MAM7. The model is able to qualitatively capture the observed geographical and temporal variations of aerosol mass and number concentrations, size distributions, and aerosol optical properties. However, there are noticeable biases, e.g., simulated sulfate and mineral dust concentrations at surface over the oceans are too low. Simulated BC concentrations are significant low in the Arctic. There is a low bias in modeled aerosol optical depth on the global scale, especially in the developing counties. There biases in aerosol simulations clearly indicate the need for improvements of aerosol processes (e.g., emission fluxes of anthropogenic aerosols and precursor gases in developing countries, boundary layer nucleation) and properties (e.g., primary aerosol emission size, POM hygroscopicity). In addition the critical role of cloud properties (e.g., liquid water content, cloud fraction) responsible for the wet scavenging of aerosol is highlighted.

Liu, Xiaohong; Easter, Richard C.; Ghan, Steven J.; Zaveri, Rahul A.; Rasch, Philip J.; Shi, Xiangjun; Lamarque, J.-F.; Gettelman, A.; Morrison, H.; Vitt, Francis; Conley, Andrew; Park, S.; Neale, Richard; Hannay, Cecile; Ekman, A. M.; Hess, Peter; Mahowald, N.; Collins, William D.; Iacono, Michael J.; Bretherton, Christopher S.; Flanner, M. G.; Mitchell, David

2012-05-21T23:59:59.000Z

364

Negative mass  

E-Print Network (OSTI)

Some physical aspects of negative mass are examined. Several unusual properties, such as the ability of negative mass to penetrate any armor, are analyzed. Other surprising effects include the bizarre system of negative mass chasing positive pass, naked singularities and the violation of cosmic censorship, wormholes, and quantum mechanical results as well. In addition, a brief look into the implications for strings is given.

Richard T Hammond

2013-08-06T23:59:59.000Z

365

Assessing regional scale predictions of aerosols, marine stratocumulus, and their interactions during VOCALS-REx using WRF-Chem  

Science Conference Proceedings (OSTI)

In the recent chemistry version (v3.3) of the Weather Research and Forecasting (WRF-Chem) model, we have coupled the Morrison double-moment microphysics scheme with interactive aerosols so that full two-way aerosol-cloud interactions are included in simulations. We have used this new WRF-Chem functionality in a study focused on assessing predictions of aerosols, marine stratocumulus clouds, and their interactions over the Southeast Pacific using measurements from the VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx) and satellite retrievals. This study also serves as a detailed analysis of our WRF-Chem simulations contributed to the VOCALS model Assessment (VOCA) project. The WRF-Chem 31-day (October 15-November 16, 2008) simulation with aerosol-cloud interactions (AERO hereafter) is also compared to a simulation (MET hereafter) with fixed cloud droplet number concentrations assumed by the default in Morrison microphysics scheme with no interactive aerosols. The well-predicted aerosol properties such as number, mass composition, and optical depth lead to significant improvements in many features of the predicted stratocumulus clouds: cloud optical properties and microphysical properties such as cloud top effective radius, cloud water path, and cloud optical thickness, and cloud macrostructure such as cloud depth and cloud base height. These improvements in addition to the aerosol direct and semi-direct effects, in turn, feed back to the prediction of boundary-layer characteristics and energy budgets. Particularly, inclusion of interactive aerosols in AERO strengths temperature and humidity gradients within capping inversion layer and lowers the MBL depth by 150 m from that of the MET simulation. Mean top-of-the-atmosphere outgoing shortwave fluxes, surface latent heat, and surface downwelling longwave fluxes are in better agreement with observations in AERO, compared to the MET simulation. Nevertheless, biases in some of the simulated meteorological quantities (e.g., MBL temperature and humidity over the remote ocean) and aerosol quantities (e.g., overestimations of supermicron sea salt mass) might affect simulated stratocumulus and energy fluxes over the SEP, and require further investigations. Although not perfect, the overall performance of the regional model in simulating mesoscale aerosol-cloud interactions is encouraging and suggests that the inclusion of spatially varying aerosol characteristics is important when simulating marine stratocumulus over the southeastern Pacific.

Yang, Qing; Gustafson, William I.; Fast, Jerome D.; Wang, Hailong; Easter, Richard C.; Morrison, H.; Lee, Y.- N.; Chapman, Elaine G.; Spak, S. N.; Mena-Carrasco, M. A.

2011-12-02T23:59:59.000Z

366

Studying trends in biomass burning aerosol using the Absorbing Aerosol Index derived from GOME, SCIAMACHY, and GOME-2  

E-Print Network (OSTI)

Studying trends in biomass burning aerosol using the Absorbing Aerosol Index derived from GOME burning events. It is found that the regional AAI data follow the regional tropospheric NO2 data well sensitive to desert dust aerosols (DDA) and biomass burning aerosols (BBA). See Figure 1. The AAI

Tilstra, Gijsbert

367

© Author(s) 2007. This work is licensed under a Creative Commons License. Atmospheric Chemistry and Physics Global 2-D intercomparison of sectional and modal aerosol modules  

E-Print Network (OSTI)

Abstract. We present an intercomparison of several aerosol modules, sectional and modal, in a global 2-D model in order to differentiate their behavior for tropospheric and stratospheric applications. We model only binary sulfuric acidwater aerosols in this study. Three versions of the sectional model and three versions of the modal model are used to test the sensitivity of background aerosol mass and size distribution to the number of bins or modes and to the prescribed width of the largest mode. We find modest sensitivity to the number of bins (40 vs. 150) used in the sectional model. Aerosol mass is found to be reduced in a modal model if care is not taken in selecting the width of the largest lognormal mode, reflecting differences in sedimentation in the middle stratosphere. The size distributions calculated by the sectional model can be better matched by a modal model with four modes rather than three modes in most but not all situations. A simulation of aerosol decay following the 1991 eruption of Mt. Pinatubo shows that the representation of the size distribution can have a signficant impact on modelcalculated aerosol decay rates in the stratosphere. Between 1991 and 1995, aerosol extinction and surface area density calculated by two versions of the modal model adequately match results from the sectional model. Calculated effective radius for the same time period shows more intermodel variability, with a 20-bin sectional model performing much better than any of the modal models. 1

D. K. Weisenstein; J. E. Penner; M. Herzog; X. Liu

2007-01-01T23:59:59.000Z

368

Gamma-ray spectrometer utilizing xenon at high pressure  

SciTech Connect

A prototype gamma-ray spectrometer utilizing xenon gas near the critical point (166{degrees}C, 58 atm) is under development. The spectrometer will function as a room-temperature ionization chamber detecting gamma rays in the energy range 100 keV2 MeV, with an energy resolution intermediate between semiconductor (Ge) and scintillation (NaI) spectrometers. The energy resolution is superior to that of a NaI scintillation spectrometer by a substantial margin (approximately a factor 5), and accordingly, much more information can be extracted from a given gamma-ray spectrum. Unlike germanium detectors, the spectrometer possesses the capability for sustained operation under ambient temperature conditions without a requirement for liquid nitrogen.

Smith, G.C.; Mahler, G.J.; Yu, B.; Kane, W.R. [Brookhaven National Lab., Upton, NY (United States); Markey, J.K. [Yale Univ., New Haven, CT (United States). School of Medicine

1994-08-01T23:59:59.000Z

369

Aerosol effects on red blue ratio of clear sky images, and impact on solar forecasting  

E-Print Network (OSTI)

urban, and desert dust aerosols ." JOURNAL OF GEOPHYSICALand K. V. S. Badarinath. "Aerosol climatology: dependence ofUsing a Sky Imager for aerosol characterization."

Ghonima, Mohamed Sherif

2011-01-01T23:59:59.000Z

370

Emissions of trace gases and aerosols during the open combustion of biomass in the laboratory  

E-Print Network (OSTI)

in press), Organic aerosols in the earth's atmosphere,loss, and trace gas and aerosol emissions during laboratoryproperties of biomass burn aerosols, Geophysical Research

McMeeking, Gavin R.

2009-01-01T23:59:59.000Z

371

Aerosol indirect effects -- general circulation model intercomparison and evaluation with satellite data  

E-Print Network (OSTI)

J. : A parameterization of aerosol activation - 3. Sectionalclouds on indirect aerosol climate forcing, Nature, 432,2004. Albrecht, B. A. : Aerosols, cloud microphysics, and

Quaas, Johannes

2010-01-01T23:59:59.000Z

372

Secondary Organic Aerosol Formation from Primary Aliphatic Amines with Nitrate Radical  

E-Print Network (OSTI)

back- ground atmospheric aerosol in the UK determined inof secondary organic aerosols, Atmos. Environ. , 31, 3921–et al. : Secondary organic aerosol formation from amines

Malloy, Q G J; Qi, L; Warren, B; Cocker III, D R; Erupe, M E; Silva, P J

2009-01-01T23:59:59.000Z

373

Impacts of aerosol-cloud interactions on past and future changes in tropospheric composition  

E-Print Network (OSTI)

of gas-phase chemistry-aerosol interactions on directforcing by anthropogenic aerosols and ozone, J. Geophys.GCM to constrain the aerosol indirect effect, J. Geophys.

Menon, S.

2009-01-01T23:59:59.000Z

374

Correlations between Optical, Chemical and Physical Properties of Biomass Burn Aerosols  

E-Print Network (OSTI)

instruments and photoelectric aerosol sensors in source-sampling of black carbon aerosol and particle-bound PAHsAirborne minerals and related aerosol particles: Effects on

2008-01-01T23:59:59.000Z

375

Composition, sources, and formation of secondary organic aerosols from urban emissions  

E-Print Network (OSTI)

organonitrate functional groups in aerosol particles200 5.1v aerosol Chapter 3 Meteorological conditions during theSecondary organic aerosol formation from fossil fuel sources

Liu, Shang; Liu, Shang

2012-01-01T23:59:59.000Z

376

X-RAY METHODS FOR THE CHEMICAL CHARACTERIZATION OF ATMOSPHERIC AEROSOLS  

E-Print Network (OSTI)

Goulding Fine Particles: Aerosol Generation, Sampling andCHARACTERIZATION OF ATMOSPHERIC AEROSOLS J.M. Jaklevic andCHARACTERIZATION OF ATMOSPHERIC AEROSOLS J.M. Jaklevic and

Jaklevic, J.M.

2010-01-01T23:59:59.000Z

377

Chapter 3: Evaluating the impacts of carbonaceous aerosols on clouds and climate  

E-Print Network (OSTI)

Cloud susceptibility and the first aerosol indirect forcing:Sensitivity to BC and aerosol concentrations. J. Geophys.of cloud droplet and aerosols number concentrations:

Menon, Surabi

2008-01-01T23:59:59.000Z

378

Measurements of the chemical, physical, and optical properties of single aerosol particles  

E-Print Network (OSTI)

composition of ambient aerosol particles, EnvironmentalParticle Measurement of Ambient Aerosol Particles Containingfor quantifying direct aerosol forcing of climate, Bull. Am.

Moffet, Ryan Christopher

2007-01-01T23:59:59.000Z

379

DETERMINATION OF CARBON IN ATMOSPHERIC AEROSOLS BY DEUTERON-INDUCED NUCLEAR REACTIONS  

E-Print Network (OSTI)

deuteron irradiation of an atmospheric aerosol sample.CARBON IN ATMOSPHERIC AEROSOLS BY DEUTERON-INDUCED NUCLEARCARBON IN ATMOSPHERIC AEROSOLS BY DEUTERON-INDUCED NUCLEAR

Clemenson, Mark

2013-01-01T23:59:59.000Z

380

On the Importance of Organic Oxygen for Understanding Organic Aerosol Particles  

E-Print Network (OSTI)

carbon fractions in atmospheric aerosols, J. Geophys. Res. -particulate diesel exhaust, Aerosol Sci. Technol. 25: 221-climate forcing of carbonaceous aerosols, J. Geophys. Res. -

Pang, Y.; Turpin, B.J.; Gundel, L.A.

2005-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol mass spectrometer" 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

Aerosol indirect effects ? general circulation model intercomparison and evaluation with satellite data  

E-Print Network (OSTI)

Oscillation influence aerosol variability? , J. Geophys.clouds on indirect aerosol climate forcing, Nature, 432,2004. Albrecht, B. A. : Aerosols, cloud microphysics, and

Quaas, Johannes

2010-01-01T23:59:59.000Z

382

Real time in situ detection of organic nitrates in atmospheric aerosols  

E-Print Network (OSTI)

Biogenic Secondary Organic Aerosol. J. Phys. Chem. A 2008,H. Secondary organic aerosol (SOA) formation from reactionsec- ondary organic aerosol yields. Atmospheric Chemistry

Rollins, Andrew W.

2011-01-01T23:59:59.000Z

383

Secondary Organic Aerosol Formation From Radical-Initiated Reactions of Alkenes: Development of Mechanisms  

E-Print Network (OSTI)

and Secondary Organic Aerosols in Southern California duringSources of Organic Carbon Aerosols in the Free Troposphere21 co-authors), 2005. Organic Aerosol and Global Climate

Matsunaga, Aiko

2009-01-01T23:59:59.000Z

384

Aerosol organic carbon to black carbon ratios: Analysis of published data and implications for climate forcing  

E-Print Network (OSTI)

Ryu (2004), Carbonaceous aerosol characteristics ofPM 2.5Allen (1990), Transported acid aerosols measured in southernconference international aerosol carbon round robin test

Novakov, T.; Menon, S.; Kirchstetter, T.W.; Koch, D.; Hansen, J.E.

2005-01-01T23:59:59.000Z

385

ATMOSPHERIC AEROSOL RESEARCH FY-1979, CHAPTER IN THE ENERGY AND ENVIRONMENT ANNUAL REPORT, 1979  

E-Print Network (OSTI)

California atmospheric aerosols," Environ. Sci. Technol. ll•suspensions," in Atmospheric Aerosol Research Annual Report,formation," in Atmospheric Aerosol Research Annual Report,

Authors, Various

2013-01-01T23:59:59.000Z

386

Detection Efficiency of a ToF Spectrometer from Heavy-Ion Elastic Recoil Detection  

SciTech Connect

The detection efficiency of a time-of-flight system based on two micro-channel plates (MCP) time zero detectors plus a conventional silicon surface barrier detector was obtained from heavy ion elastic recoil measurements (this ToF spectrometer is mainly devoted to measurements of total fusion cross section of weakly bound projectiles on different mass-targets systems). In this work we have used beams of {sup 7}Li, {sup 16}O, {sup 32}S and {sup 35}Cl to study the mass region of interest for its application to measurements fusion cross sections in the {sup 6,7}Li+{sup 27}Al systems at energies around and above the Coulomb barrier (0.8V{sub B{<=}}E{<=}2.0V{sub B}). As the efficiency of a ToF spectrometer is strongly dependent on the energy and mass of the detected particles, we have covered a wide range of the scattered particle energies with a high degree of accuracy at the lowest energies. The different experimental efficiency curves obtained in that way were compared with theoretical electronic stopping power curves on carbon foils and were applied.

Barbara, E. de; Marti, G. V.; Capurro, O. A.; Fimiani, L.; Mingolla, M. G. [Laboratorio ANDAR, Comision Nacional de Energia Atomica, Av. Gral. Paz 1499, B1650KNA Partido de San Martin, Provincia de Buenos Aires (Argentina); Negri, A. E.; Arazi, A.; Figueira, J. M.; Pacheco, A. J.; Martinez Heimann, D.; Carnelli, P. F. F. [Laboratorio ANDAR, Comision Nacional de Energia Atomica, Av. Gral. Paz 1499, B1650KNA Partido de San Martin, Provincia de Buenos Aires (Argentina); CONICET, Av. Rivadavia 1917, C1033AAJ Ciudad Autonoma de Buenos Aires (Argentina); Fernandez Niello, J. O. [Laboratorio ANDAR, Comision Nacional de Energia Atomica, Av. Gral. Paz 1499, B1650KNA Partido de San Martin, Provincia de Buenos Aires (Argentina); CONICET, Av. Rivadavia 1917, C1033AAJ Ciudad Autonoma de Buenos Aires (Argentina); Universidad Nacional de General San Martin, Ayacucho 2197, B1650BWA Partido de San Martin, Provincia de Buenos Aires (Argentina)

2010-08-04T23:59:59.000Z

387

Analysis of shipboard aerosol optical thickness measurements from multiple sunphotometers aboard the R/V Ronald H. Brown during the Aerosol Characterization Experiment - Asia  

SciTech Connect

Marine sunphotometer measurements collected aboard the R/V Ronald H. Brown during the Aerosol Characterization Experiment - Asia (ACE-Asia) are used to evaluate the ability of complementary instrumentation to obtain the best possible estimates of aerosol optical thickness and Angstrom exponent from ships at sea. A wide range of aerosol conditions, including clean maritime conditions and highly polluted coastal environments, were encountered during the ACE-Asia cruise. The results of this study suggest that shipboard hand-held sunphotometers and fast-rotating shadow-band radiometers (FRSRs) yield similar measurements and uncertainties if proper measurement protocols are used and if the instruments are properly calibrated. The automated FRSR has significantly better temporal resolution (2 min) than the hand-held sunphotometers when standard measurement protocols are used, so it more faithfully represents the variability of the local aerosol structure in polluted regions. Conversely, results suggest that the hand-held sunphotometers may perform better in clean, maritime air masses for unknown reasons. Results also show that the statistical distribution of the Angstrom exponent measurements is different when the distributions from hand-held sunphotometers are compared with those from the FRSR and that the differences may arise from a combination of factors.

Miller, Mark A.; Knobelspiesse, Kirk; Frouin, Robert; Bartholomew, Mary Jane; Reynolds, R. Michael; Pietras, Christophe; Fargion, Giulietta; Quinn, Patricia; Thieuleux, Francois

2005-06-20T23:59:59.000Z

388

What Happened with Spectrometer Magnet 2B  

E-Print Network (OSTI)

of Cold Mass at E2 End TSD1 (K) T Outside Condenser 1 TSD2 (K) T Outside Condenser 2 TSD3 (K) T Outside Condenser 3 TSD4 (K) T inside Cryostat Bottom

Green, Michael A

2010-01-01T23:59:59.000Z

389

Evaluating Global Aerosol Models and Aerosol and Water Vapor Properties Near Clouds  

Science Conference Proceedings (OSTI)

Project goals: (1) Use the routine surface and airborne measurements at the ARM SGP site, and the routine surface measurements at the NSA site, to continue our evaluations of model aerosol simulations; (2) Determine the degree to which the Raman lidar measurements of water vapor and aerosol scattering and extinction can be used to remotely characterize the aerosol humidification factor; (3) Use the high temporal resolution CARL data to examine how aerosol properties vary near clouds; and (4) Use the high temporal resolution CARL and Atmospheric Emitted Radiance Interferometer (AERI) data to quantify entrainment in optically thin continental cumulus clouds.

Richard A. Ferrare; David D. Turner

2011-09-01T23:59:59.000Z

390

PTAX: the Polarized Triple-Axis Spectrometer at HFIR | ORNL Neutron...  

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

The Polarized Triple-Axis Spectrometer at HFIR HB-1 photo Polarized Triple-Axis Spectrometer (HB-1). Of the four triple-axis spectrometers installed at HFIR, the HB-1 instrument is...

391

Developing models of aerosol representation to investigate composition, evolution, optical properties, and CCN spectra using measurements of size-resolved hygroscopicity  

E-Print Network (OSTI)

A Differential Mobility Analyzer/Tandem Differential Mobility Analyzer (DMA/TDMA) was used to measure size distributions, hygroscopicity, and volatility during the May 2003 Aerosol Intensive Operational Period at the Central Facility of the Atmospheric Radiation Measurement Southern Great Plains site. Hygroscopic growth factor distributions for particles at eight dry diameters ranging from 0.012 µm to 0.600 µm were measured. These measurements, along with backtrajectory clustering, were used to infer aerosol composition and evolution. The hygroscopic growth of the smallest and largest particles analyzed was typically less than that of particles with dry diameters of about 0.100 µm. Condensation of secondary organic aerosol on nucleation mode particles may be responsible for the minimal growth observed at the smallest sizes. Growth factor distributions of the largest particles typically contained a non-hygroscopic mode believed to be composed of dust. A model was developed to characterize the hygroscopic properties of particles within a size distribution mode through analysis of the fixed-size hygroscopic growth measurements. This model was used to examine three cases in which the sampled aerosol evolved over a period of hours or days. Additionally, size and hygroscopicity information were combined to model the aerosol as a population of multi-component particles. With this model, the aerosol hygroscopic growth factor f(RH), relating the submicron scattering at high RH to that at low RH, is predicted. The f(RH) values predicted when the hygroscopic fraction of the aerosol is assumed to be metastable agree better with measurements than do those predicted under the assumption of crystalline aerosol. Agreement decreases at RH greater than 65%. This multi-component aerosol model is used to derive cloud condensation nuclei (CCN) spectra for comparison with spectra measured directly with two Desert Research Institute (DRI) CCN spectrometers. Among the 1490 pairs of DMA/TDMA-predicted and DRI-measured CCN concentrations at various critical supersaturations from 0.02-1.05%, the sample number-weighted mean R2 value is 0.74. CCN concentrations are slightly overpredicted at both the lowest (0.02-0.04%) and highest (0.80-1.05%) supersaturations measured. Overall, this multi-component aerosol model based on size distributions and size-resolved hygroscopicity yields reasonable predictions of the humidity-dependent optical properties and CCN spectra of the aerosol.

Gasparini, Roberto

2003-05-01T23:59:59.000Z

392

Composition and Reactions of Atmospheric Aerosol Particles  

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

Composition and Reactions of Composition and Reactions of Atmospheric Aerosol Particles Composition and Reactions of Atmospheric Aerosol Particles Print Wednesday, 29 June 2005 00:00 Microscopic aerosol particles in the atmosphere contain carbonaceous components from mineral dust and combustion emissions released from around the world. How long these tiny particles remain in the atmosphere can have a huge impact on the global climate. Measurements based on high-resolution scanning transmission x-ray images obtained at the ALS have revealed chemical reactions on and in atmospheric aerosol particles that caused particle growth while changing organic composition by 13 to 24% per day, an oxidation rate significantly slower than is currently used in atmospheric models. Since oxidation has a strong effect on particle lifetime in the atmosphere, these results will help climate scientists refine the computer models used to predict climate change.

393

BNL | Two-Column Aerosol Program (TCAP)  

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

Two-Column Aerosol Project (TCAP) Two-Column Aerosol Project (TCAP) There remain many key knowledge gaps despite advances in the scientific understanding of how aerosols and clouds evolve and affect climate. Many climatically important processes depend on particles that undergo continuous changes within a size range spanning a few nanometers to a few microns, and with compositions that consist of a variety of carbonaceous materials, soluble inorganic salts and acids and insoluble mineral dust. Primary particles, which are externally-mixed when emitted, are subject to coagulation and chemical changes associated with the condensation of semi-volatile gases to their surface resulting in a spectrum of compositions or mixing-states with a range of climate-affecting optical and hygroscopic properties. The numerical treatments of aerosol transformation

394

Composition and Reactions of Atmospheric Aerosol Particles  

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

Composition and Reactions of Atmospheric Aerosol Particles Print Composition and Reactions of Atmospheric Aerosol Particles Print Microscopic aerosol particles in the atmosphere contain carbonaceous components from mineral dust and combustion emissions released from around the world. How long these tiny particles remain in the atmosphere can have a huge impact on the global climate. Measurements based on high-resolution scanning transmission x-ray images obtained at the ALS have revealed chemical reactions on and in atmospheric aerosol particles that caused particle growth while changing organic composition by 13 to 24% per day, an oxidation rate significantly slower than is currently used in atmospheric models. Since oxidation has a strong effect on particle lifetime in the atmosphere, these results will help climate scientists refine the computer models used to predict climate change.

395

Eastern Pacific Emitted Aerosol Cloud Experiment  

Science Conference Proceedings (OSTI)

Aerosol–cloud–radiation interactions are widely held to be the largest single source of uncertainty in climate model projections of future radiative forcing due to increasing anthropogenic emissions. The underlying causes of this uncertainty among modeled ...

Lynn M. Russell; Armin Sorooshian; John H. Seinfeld; Bruce A. Albrecht; Athanasios Nenes; Lars Ahlm; Yi-Chun Chen; Matthew Coggon; Jill S. Craven; Richard C. Flagan; Amanda A. Frossard; Haflidi Jonsson; Eunsil Jung; Jack J. Lin; Andrew R. Metcalf; Robin Modini; Johannes Mülmenstädt; Greg Roberts; Taylor Shingler; Siwon Song; Zhen Wang; Anna Wonaschütz

2013-05-01T23:59:59.000Z

396

ARM - Campaign Instrument - aerosol-tower-eml  

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

govInstrumentsaerosol-tower-eml Comments? We would love to hear from you Send us a note below or call us at 1-888-ARM-DATA. Send Campaign Instrument : EML Tower based Aerosol...

397

Remote Sensing of Aerosol Properties during CARES  

SciTech Connect

One month of MFRSR data collected at two sites in the central California (USA) region during the CARES campaign are processed and the MFRSR-derived AODs at 500 nm wavelength are compared with available AODs provided by AERONET measurements. We find that the MFRSR and AERONET AODs are small ({approx}0.05) and comparable. A reasonable quantitative agreement between column aerosol size distributions (up to 2 um) from the MFRSR and AERONET retrievals is illustrated as well. Analysis of the retrieved (MFRSR and AERONET) and in situ measured aerosol size distributions suggests that the contribution of the coarse mode to aerosol optical properties is substantial for several days. The results of a radiative closure experiment performed for the two sites and one-month period show a favorable agreement between the calculated and measured broadband downwelling irradiances (bias does not exceed about 3 Wm-2), and thus imply that the MFRSR-derived aerosol optical properties are reasonable.

Kassianov, Evgueni I.; Barnard, James C.; Pekour, Mikhail S.; Flynn, Connor J.; Ferrare, R.; Hostetler, Chris A.; Hair, John; Jobson, Bertram Thomas

2011-10-01T23:59:59.000Z

398

The Life Cycle of Stratospheric Aerosol Particles  

Science Conference Proceedings (OSTI)

This paper describes the life cycle of the background (nonvolcanic) stratospheric sulfate aerosol. The authors assume the particles are formed by homogeneous nucleation near the tropical tropopause and are carried aloft into the stratosphere. The ...

Patrick Hamill; Eric J. Jensen; P. B. Russell; Jill J. Bauman

1997-07-01T23:59:59.000Z

399

Exploring Atmospheric Aerosols by Twilight Photometry  

Science Conference Proceedings (OSTI)

The instrument twilight photometer was designed, developed, and installed at the Indian Institute of Tropical Meteorology (IITM), Pune, India (18°43?N, 73°51?E), to monitor the vertical distribution of atmospheric aerosols. The instrument, based ...

B. Padma Kumari; S. H. Kulkarni; D. B. Jadhav; A. L. Londhe; H. K. Trimbake

2008-09-01T23:59:59.000Z

400

On the Background Stratospheric Aerosol Layer  

Science Conference Proceedings (OSTI)

Balloonborne aerosol particle counter measurements are used in studying the stratospheric sulfate layer at Laramie, Wyoming, during 1978 and 1979, a 2-year volcanically quiescent period in which the layer appears to have been in a near ...

D. J. Hofmann; J. M. Rosen

1981-01-01T23:59:59.000Z

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


401

Study of Aerosol Indirect Effects in China  

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

Aerosol Indirect Effects in China In 2008, the U.S. Department of Energy (DOE)'s Atmospheric Radiation Measurement (ARM) Climate Research Facility is providing the ARM Mobile...

402

Radiative and climate impacts of absorbing aerosols  

E-Print Network (OSTI)

during SHADE: 1. Solar spectrum, J. Geophys. Res . , 108(sensed data in the solar spectrum, J. Geophys. Res , 106 (a scattering aerosol in the solar spectrum with a SSA=1 and

Zhu, Aihua

2010-01-01T23:59:59.000Z

403

A New Method for Measuring Aerosol Absorption  

Science Conference Proceedings (OSTI)

A new technique has recently been developed to measure aerosol absorption by means of a microdensitometer. Black particulate material is collected into six spots on membrane filters by a laboratory-tested impaction/concentration technique. Follow-...

B. B. Murphey; S. I. Reynolds

1988-08-01T23:59:59.000Z

404

Aerosol Transport in the Southern Sierra Nevada  

Science Conference Proceedings (OSTI)

Aerosol transport and meteorology were investigated during 10 days in August 1985, at three elevations in the southern Sierra. Ground weather station and pilot balloon data revealed the diurnal variation of the topographic winds to be remarkably ...

D. M. Ewell; R. G. Flocchini; L. O. Myrup; T. A. Cahill

1989-02-01T23:59:59.000Z

405

Urban Aerosol Impacts on Downwind Convective Storms  

Science Conference Proceedings (OSTI)

The impacts of urban-enhanced aerosol concentrations on convective storm development and precipitation over and downwind of St. Louis, Missouri, are investigated. This is achieved through the use of a cloud-resolving mesoscale model, in which ...

Susan C. van den Heever; William R. Cotton

2007-06-01T23:59:59.000Z

406

Aerosol Best Estimate Value-Added Product  

Science Conference Proceedings (OSTI)

The objective of the Aerosol Best Estimate (AEROSOLBE) value-added product (VAP) is to provide vertical profiles of aerosol extinction, single scatter albedo, asymmetry parameter, and Angstroem exponents for the atmospheric column above the Central Facility at the ARM Southern Great Plains (SGP) site. We expect that AEROSOLBE will provide nearly continuous estimates of aerosol optical properties under a range of conditions (clear, broken clouds, overcast clouds, etc.). The primary requirement of this VAP was to provide an aerosol data set as continuous as possible in both time and height for the Broadband Heating Rate Profile (BBHRP) VAP in order to provide a structure for the comprehensive assessment of our ability to model atmospheric radiative transfer for all conditions. Even though BBHRP has been completed, AEROSOLBE results are very valuable for environmental, atmospheric, and climate research.

Flynn, C; Turner, D; Koontz, A; Chand, D; Sivaraman, C

2012-07-19T23:59:59.000Z

407

Emerging Technology for Measuring Atmospheric Aerosol Properties...  

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

Brookhaven Laboratory and with funding from the DOE STTR program. DMT is developing a new technique for measuring aerosol size distributions in the sub-0.1 um size range. The...

408

Composition and Reactions of Atmospheric Aerosol Particles  

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

Composition and Reactions of Atmospheric Aerosol Particles Print Composition and Reactions of Atmospheric Aerosol Particles Print Microscopic aerosol particles in the atmosphere contain carbonaceous components from mineral dust and combustion emissions released from around the world. How long these tiny particles remain in the atmosphere can have a huge impact on the global climate. Measurements based on high-resolution scanning transmission x-ray images obtained at the ALS have revealed chemical reactions on and in atmospheric aerosol particles that caused particle growth while changing organic composition by 13 to 24% per day, an oxidation rate significantly slower than is currently used in atmospheric models. Since oxidation has a strong effect on particle lifetime in the atmosphere, these results will help climate scientists refine the computer models used to predict climate change.

409

ARM - Field Campaign - Aerosol Lidar Validation Experiment -...  

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

govCampaignsAerosol Lidar Validation Experiment - ALIVE Campaign Links ALIVE Website Comments? We would love to hear from you Send us a note below or call us at 1-888-ARM-DATA....

410

DETERMINATION OF RADIAL MOMENTS OF AN AEROSOL  

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

DETERMINATION OF RADIAL MOMENTS OF AN AEROSOL DETERMINATION OF RADIAL MOMENTS OF AN AEROSOL SIZE DISTRIBUTION FROM MEASUREMENTS OF LIGHT TRANSMITTANCE AND SCATTERING Ernie R. Lewis and Stephen E. Schwartz Brookhaven National Laboratory, Upton, NY 11933 ses@bnl.gov elewis@bnl.gov MOMENTS FROM MEASUREMENTS As each of the measured quantities is linear in the size distribution dn/dr, it is possible to construct linear combinations of measurements that yield

411

Apparatus for sampling and characterizing aerosols  

DOE Patents (OSTI)

Apparatus for sampling and characterizing aerosols having a wide particle size range at relatively low velocities may comprise a chamber having an inlet and an outlet, the chamber including: a plurality of vertically stacked, successive particle collection stages; each collection stage includes a separator plate and a channel guide mounted transverse to the separator plate, defining a labyrinthine flow path across the collection stage. An opening in each separator plate provides a path for the aerosols from one collection stage t

Dunn, P.F.; Herceg, J.E.; Klocksieben, R.H.

1984-04-11T23:59:59.000Z

412

Mass Measurements  

Science Conference Proceedings (OSTI)

... NIST maintains the national standard for mass in the form of the prototype kilogram (K20) and provides services to support the parts of the national ...

2013-06-28T23:59:59.000Z

413

fehlende Masse  

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

beim radioaktiven Zerfall mit der fehlenden Masse?" Zur Erinnerung: wenn Uran in Thorium und ein alpha Teilchen zerfllt, dann gehen 0.0046 u (Masseneinheiten) der...

414

Al(26) Studies with INTEGRAL's Spectrometer SPI  

E-Print Network (OSTI)

Al(26) radioactivity traces recent nucleosynthesis throughout the Galaxy, and is known to be produced in massive stars and novae. The map from its decay gamma-ray line suggests massive stars to dominate, but high-resolution line spectroscopy is expected to supplement imaging of Al(26) source regions and thus to help decide about the Al(26) injection process and interstellar environment, hence about the specific massive-star subgroup and phase which produces interstellar Al(26). The INTEGRAL Spectrometer SPI has observed Galactic Al(26) radioactivity in its 1809 keV gamma-ray line during its first inner-Galaxy survey. Instrumental background lines make analysis difficult; yet, a clear signal from the inner Galaxy agrees with expectations. In particular, SPI has constrained the line width to exclude previously-reported line broadenings corresponding to velocities >500 km/s. The signal-to-background ratio of percent implies that detector response and background modeling need to be fine-tuned to eventually enable line shape deconvolution in order to extract source location information along the line of sight.

R. Diehl; K. Kretschmer; G. Lichti; V. Schönfelder; A. W. Strong; A. von Kienlin; J. Knödlseder; P. Jean; V. Lonjou; G. Weidenspointner; J. -P. Roques; G. Vedrenne; S. Schanne; N. Mowlavi; C. Winkler; C. Wunderer

2004-05-11T23:59:59.000Z

415

ARM - Publications: Science Team Meeting Documents: A decade long aerosol  

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

A decade long aerosol and cloud statistics and aerosol indirect effect at A decade long aerosol and cloud statistics and aerosol indirect effect at the ARM SGP site Min, Qilong State University of New York at Albany Duan, Minzheng State University of New York at Albany Harrison, Lee State University of New York Joseph, Everette Howard University Twelve-year data of MFRSR and MWR have been used to derive aerosol and cloud optical properties at the ARM SGP. Diurnal, monthly, seasonal and interannual variability of aerosol (optical depth and Angstrom coefficient) and cloud (optical depth and effective radius) have been analyzed. We specially focused on aerosol-cloud interactions. We found a signature of indirect aerosol effect for summer data: increased aerosol index has a statistically-significant anti-correlation with mean effective radius. No

416

Examination of the Effects of Sea Salt Aerosols on Southeast Texas Ozone and Secondary Organic Aerosol  

E-Print Network (OSTI)

Despite decades of study, we still do not fully understand aerosols and their interactions among gases or other aerosols in the atmosphere. Among their impacts, they influence radiative transfer in the atmosphere and contribute to cloud formation. There are many different types of aerosols, including dust particles, soot particles, and microscopic particles containing inorganic compounds such as sulfates. Most of these particles have natural origins, but many are anthropogenic. The eventual purpose of this research is to examine sea salt aerosols and their impact on polluted environments. Sea salt aerosols act as Cloud Condensation Nuclei (CCN) as well as providing a surface for heterogeneous reactions. Such reactions have implications for trace gases such as ozone, reactive nitrogen, mercury, and sulfur containing compounds. Urban areas are most impacted by these trace gases, which is a concern because ozone especially affects the health of citizens. Experiments have three basic parts. First we generate mono-disperse 3 aerosols. That aerosol is then injected into the aerosol chambers with sea salt aerosols and prescribed concentrations of trace gases to characterize relevant interactions. However, those chambers are still under construction and not used during my study. The processed aerosols are then analyzed with a tandem differential mobility analyzer (TDMA) and other equipment. Different concentrations of sea salt aerosols, Cl, NOx, and other gases were planned to be introduced during the experiments. Concentrations of other gases and intensity of solar radiation would mimic those outside. Because these reactions have proved to increase localized concentrations of ozone in other work, this could have important implications. Future work will be designed to find study these interactions. This is important because the EPA has considered tightening the standards for both ozone and particulate matter. Industries would then need to reduce emissions or move farther from current sources of Cl or NOx pollution.

Benoit, Mark David

2013-05-01T23:59:59.000Z

417

Climatology of aerosol optical depth in north?central Oklahoma: 1992–2008  

SciTech Connect

Aerosol optical depth (AOD) has been measured at the Atmospheric Radiation Measurement Program central facility near Lamont, Oklahoma, since the fall of 1992. Most of the data presented are from the multifilter rotating shadowband radiometer, a narrow?band, interference?filter Sun radiometer with five aerosol bands in the visible and near infrared; however, AOD measurements have been made simultaneously and routinely at the site by as many as three different types of instruments, including two pointing Sun radiometers. Scatterplots indicate high correlations and small biases consistent with earlier comparisons. The early part of this 16 year record had a disturbed stratosphere with residual Mt. Pinatubo aerosols, followed by the cleanest stratosphere in decades. As such, the last 13 years of the record reflect changes that have occurred predominantly in the troposphere. The field calibration technique is briefly described and compared to Langley calibrations from Mauna Loa Observatory. A modified cloudscreening technique is introduced that increases the number of daily averaged AODs retrieved annually to about 250 days compared with 175 days when a more conservative method was employed in earlier studies. AODs are calculated when the air mass is less than six; that is, when the Sun’s elevation is greater than 9.25°. The more inclusive cloud screen and the use of most of the daylight hours yield a data set that can be used to more faithfully represent the true aerosol climate for this site. The diurnal aerosol cycle is examined month?by?month to assess the effects of an aerosol climatology on the basis of infrequent sampling such as that from satellites.

Michalsky, Joseph J.; Denn, Frederick; Flynn, Connor J.; Hodges, G. B.; Kiedron, Piotr; Koontz, Annette S.; Schlemmer, James; Schwartz, Stephen E.

2010-04-13T23:59:59.000Z

418

Climatology of aerosol optical depth in North-Central Oklahoma: 1992-2008  

SciTech Connect

Aerosol optical depth (AOD) has been measured at the Atmospheric Radiation Measurement Program central facility near Lamont, Oklahoma, since the fall of 1992. Most of the data presented are from the multifilter rotating shadowband radiometer, a narrow-band, interference-filter Sun radiometer with five aerosol bands in the visible and near infrared; however, AOD measurements have been made simultaneously and routinely at the site by as many as three different types of instruments, including two pointing Sun radiometers. Scatterplots indicate high correlations and small biases consistent with earlier comparisons. The early part of this 16 year record had a disturbed stratosphere with residual Mt. Pinatubo aerosols, followed by the cleanest stratosphere in decades. As such, the last 13 years of the record reflect changes that have occurred predominantly in the troposphere. The field calibration technique is briefly described and compared to Langley calibrations from Mauna Loa Observatory. A modified cloud-screening technique is introduced that increases the number of daily averaged AODs retrieved annually to about 250 days compared with 175 days when a more conservative method was employed in earlier studies. AODs are calculated when the air mass is less than six; that is, when the Sun's elevation is greater than 9.25{sup o}. The more inclusive cloud screen and the use of most of the daylight hours yield a data set that can be used to more faithfully represent the true aerosol climate for this site. The diurnal aerosol cycle is examined month-by-month to assess the effects of an aerosol climatology on the basis of infrequent sampling such as that from satellites.

Michalsky, J.; Schwartz, S.; Denn, F.; Flynn, C.; Hodges, G.; Kiedron, P.; Koontz, A.; Schlemmer, J., and Schwartz, S. E

2010-04-01T23:59:59.000Z

419

Comparison of a transmission grating spectrometer to a reflective grating spectrometer for standoff laser-induced breakdown spectroscopy measurements  

Science Conference Proceedings (OSTI)

We evaluate a new transmission grating spectrometer for standoff laser-induced breakdown spectroscopy (LIBS) measurements. LIBS spectra collected from standoff distances are often weak, with smaller peaks blending into the background and noise. Scattered light inside the spectrometer can also contribute to poor signal-to-background and signal-to-noise ratios for smaller emission peaks. Further, collecting standoff spectra can be difficult because most spectrometers are designed for laboratory environments and not for measurements in the field. To address these issues, a custom-designed small, lightweight transmission grating spectrometer with no moving parts was built that is well suited for standoff LIBS field measurements. The performance of the spectrometer was quantified through 10 m standoff LIBS measurements collected from aluminum alloy samples and measurements from spectra of a Hg-Ar lamp. The measurements were compared to those collected using a Czerny-Turner reflective grating spectrometer that covered a similar spectral range and used the same ICCD camera. Measurements using the transmission grating spectrometer had a 363% improved signal-to-noise ratio when measured using the 669 nm aluminum emission peak.

Weisberg, Arel; Craparo, Joseph; De Saro, Robert; Pawluczyk, Romuald

2010-05-01T23:59:59.000Z

420

Study of Mechanisms of Aerosol Indirect Effects on Glaciated Clouds: Progress during the Project Final Technical Report  

SciTech Connect

This 3-year project has studied how aerosol pollution influences glaciated clouds. The tool applied has been an 'aerosol-cloud model'. It is a type of Cloud-System Resolving Model (CSRM) modified to include 2-moment bulk microphysics and 7 aerosol species, as described by Phillips et al. (2009, 2013). The study has been done by, first, improving the model and then performing sensitivity studies with validated simulations of a couple of observed cases from ARM. These are namely the Tropical Warm Pool International Cloud Experiment (TWP-ICE) over the tropical west Pacific and the Cloud and Land Surface Interaction Campaign (CLASIC) over Oklahoma. During the project, sensitivity tests with the model showed that in continental clouds, extra liquid aerosols (soluble aerosol material) from pollution inhibited warm rain processes for precipitation production. This promoted homogeneous freezing of cloud droplets and aerosols. Mass and number concentrations of cloud-ice particles were boosted. The mean sizes of cloud-ice particles were reduced by the pollution. Hence, the lifetime of glaciated clouds, especially ice-only clouds, was augmented due to inhibition of sedimentation and ice-ice aggregation. Latent heat released from extra homogeneous freezing invigorated convective updrafts, and raised their maximum cloud-tops, when aerosol pollution was included. In the particular cases simulated in the project, the aerosol indirect effect of glaciated clouds was twice than of (warm) water clouds. This was because glaciated clouds are higher in the troposphere than water clouds and have the first interaction with incoming solar radiation. Ice-only clouds caused solar cooling by becoming more extensive as a result of aerosol pollution. This 'lifetime indirect effect' of ice-only clouds was due to higher numbers of homogeneously nucleated ice crystals causing a reduction in their mean size, slowing the ice-crystal process of snow production and slowing sedimentation. In addition to the known indirect effects (glaciation, riming and thermodynamic), new indirect effects were discovered and quantified due to responses of sedimentation, aggregation and coalescence in glaciated clouds to changing aerosol conditions. In summary, the change in horizontal extent of the glaciated clouds ('lifetime indirect effects'), especially of ice-only clouds, was seen to be of higher importance in regulating aerosol indirect effects than changes in cloud properties ('cloud albedo indirect effects').

Phillips, Vaughan T. J.

2013-10-18T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol mass spectrometer" 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

Soiling by atmospheric aerosols in an urban industrial area  

Science Conference Proceedings (OSTI)

The gradual and progressive soiling of structures exposed to the atmosphere is commonplace. Material soiling results from the deposition of atmospheric aerosols. Both wet and dry deposition occurs. The particle size and the orientation, exposure and roughness of the surface determine the dominant deposition mechanisms. Wet deposition is not an important cause of surface soiling, but precipitation removes particles from a surface. Aged atmospheric particles are characterized by a bimodal size distribution of coarse and fine particles. Coarse particles tend to be inactive chemically and are removed by washout and runoff. A primary cause of building soiling in urban areas has been attributed to the fine-particle mode. When fine particles contain carbon they tend to be black, and adhere more tenaciously to surface than do course particles. Elemental carbon is usually 10-20 percent of the urban fine aerosol mass, and vehicular emissions, particularly diesel emissions, are the major source of urban black smoke. The soiling of buildings occurs over the years from fine particle deposition and is associated with low atmospheric concentrations. This paper describes the influences of particle size and rainfall on the deposition, and on the soiling of surfaces with different surface glosses, orientations and exposures.

Creighton, P.J. (Rutgers: The State Univ., New Brunswick, NJ (USA)); Lioy, P.J. (Environmental and Occupational Health Sciences Inst., Piscataway, NJ (USA)); Haynie, F.H.; Lemmons, T.J.; Miller, J.L.; Gerhart, J. (Environmental Protection Agency, Research Triangle Park, NC (USA))

1990-08-01T23:59:59.000Z

422

Assessment of the global impact of aerosols on tropospheric oxidants  

E-Print Network (OSTI)

[1] We present here a fully coupled global aerosol and chemistry model for the troposphere. The model is used to assess the interactions between aerosols and chemical oxidants in the troposphere, including (1) the conversion from gas-phase oxidants into the condensed phase during the formation of aerosols, (2) the heterogeneous reactions occurring on the surface of aerosols, and (3) the effect of aerosols on ultraviolet radiation and photolysis rates. The present study uses the global three-dimensional chemical/ transport model, Model for Ozone and Related Chemical Tracers, version 2 (MOZART-2), in which aerosols are coupled with the model. The model accounts for the presence of

Xuexi Tie; Sasha Madronich; Stacy Walters; David P. Edwards; Paul Ginoux; Natalie Mahowald; Renyi Zhang; Chao Lou; Guy Brasseur

2005-01-01T23:59:59.000Z

423

Modeling Organic Aerosols in a Megacity: Comparison of Simple and Complex Representations of the Volatility Basis Set Approach  

Science Conference Proceedings (OSTI)

The Weather Research and Forecasting model coupled with chemistry (WRF-Chem) is modified to include a volatility basis set (VBS) treatment of secondary organic aerosol formation. The VBS approach, coupled with SAPRC-99 gas-phase chemistry mechanism, is used to model gas-particle partitioning and multiple generations of gas-phase oxidation of organic vapors. In addition to the detailed 9-species VBS, a simplified mechanism using 2 volatility species (2-species VBS) is developed and tested for similarity to the 9-species VBS in terms of both mass and oxygen-to-carbon ratios of organic aerosols in the atmosphere. WRF-Chem results are evaluated against field measurements of organic aerosols collected during the MILAGRO 2006 campaign in the vicinity of Mexico City. The simplified 2-species mechanism reduces the computational cost by a factor of 2 as compared to 9-species VBS. Both ground site and aircraft measurements suggest that the 9-species and 2-species VBS predictions of total organic aerosol mass as well as individual organic aerosol components including primary, secondary, and biomass burning are comparable in magnitude. In addition, oxygen-to-carbon ratio predictions from both approaches agree within 25%, providing evidence that the 2-species VBS is well suited to represent the complex evolution of organic aerosols. Model sensitivity to amount of anthropogenic semi-volatile and intermediate volatility (S/IVOC) precursor emissions is also examined by doubling the default emissions. Both the emission cases significantly under-predict primary organic aerosols in the city center and along aircraft flight transects. Secondary organic aerosols are predicted reasonably well along flight tracks surrounding the city, but are consistently over-predicted downwind of the city. Also, oxygen-to-carbon ratio predictions are significantly improved compared to prior studies by adding 15% oxygen mass per generation of oxidation; however, all modeling cases still under-predict these ratios downwind as compared to measurements, suggesting a need to further improve chemistry parameterizations of secondary organic aerosol formation.

Shrivastava, ManishKumar B.; Fast, Jerome D.; Easter, Richard C.; Gustafson, William I.; Zaveri, Rahul A.; Jimenez, Jose L.; Saide, Pablo; Hodzic, Alma

2011-07-13T23:59:59.000Z

424

Aerosol Characterization Data from the Asian Pacific Regional Aerosol Characterization Project (ACE-Asia)  

DOE Data Explorer (OSTI)

The Aerosol Characterization Experiments (ACE) were designed to increase understanding of how atmospheric aerosol particles affect the Earth's climate system. These experiments integrated in-situ measurements, satellite observations, and models to reduce the uncertainty in calculations of the climate forcing due to aerosol particles and improve the ability of models to predict the influences of aerosols on the Earth's radiation balance. ACE-Asia was the fourth in a series of experiments organized by the International Global Atmospheric Chemistry (IGAC) Program (A Core Project of the International Geosphere Biosphere Program). The Intensive Field Phase for ACE-Asia took place during the spring of 2001 (mid-March through early May) off the coast of China, Japan and Korea. ACE-Asia pursued three specific objectives: 1) Determine the physical, chemical, and radiative properties of the major aerosol types in the Eastern Asia and Northwest Pacific region and investigate the relationships among these properties. 2) Quantify the physical and chemical processes controlling the evolution of the major aerosol types and in particular their physical, chemical, and radiative properties. 3) Develop procedures to extrapolate aerosol properties and processes from local to regional and global scales, and assess the regional direct and indirect radiative forcing by aerosols in the Eastern Asia and Northwest Pacific region [Edited and shortened version of summary at http://data.eol.ucar.edu/codiac/projs?ACE-ASIA]. The Ace-Asia collection contains 174 datasets.

425

Aerosols in Central California: Unexpectedly Large Contribution of Coarse Mode to Aerosol Radiative Forcing  

Science Conference Proceedings (OSTI)

The majority of previous studies dealing with effect of coarse-mode aerosols on the radiation budget have focused primary on polluted regions with substantial aerosol loadings. We reexamine this effect for a relatively "pristine" area using a unique 1-month dataset collected during recent Carbonaceous Aerosol and Radiative Effects Study (CARES). We demonstrate that the coarse-mode (supermicron) particles can contribute substantially (more than 50%) and frequently (up to 85% of time) to the total volume. In contrast to the conventional expectations that the radiative impact of coarse-mode aerosols should be small for "pristine" regions, we find that the neglecting of the large particles may lead to significant overestimation (up to 45%) of direct aerosol radiative forcing at the top-of atmosphere despite of very small aerosol optical depth (about 0.05 at 0.5 ). Our findings highlight the potential for widespread impacts of the coarse-mode aerosols on the pristine radiative properties over land and the need for more explicit inclusion of the coarse-mode aerosols in climate-related observational and model studies.

Kassianov, Evgueni I.; Pekour, Mikhail S.; Barnard, James C.

2012-10-20T23:59:59.000Z

426

Evaluating Global Aerosol Models and Aerosol and Water Vapor Properties Near Clouds  

Science Conference Proceedings (OSTI)

The 'Evaluating Global Aerosol Models and Aerosol and Water Vapor Properties Near Clouds' project focused extensively on the analysis and utilization of water vapor and aerosol profiles derived from the ARM Raman lidar at the Southern Great Plains ARM site. A wide range of different tasks were performed during this project, all of which improved quality of the data products derived from the lidar or advanced the understanding of atmospheric processes over the site. These activities included: upgrading the Raman lidar to improve its sensitivity; participating in field experiments to validate the lidar aerosol and water vapor retrievals; using the lidar aerosol profiles to evaluate the accuracy of the vertical distribution of aerosols in global aerosol model simulations; examining the correlation between relative humidity and aerosol extinction, and how these change, due to horizontal distance away from cumulus clouds; inferring boundary layer turbulence structure in convective boundary layers from the high-time-resolution lidar water vapor measurements; retrieving cumulus entrainment rates in boundary layer cumulus clouds; and participating in a field experiment that provided data to help validate both the entrainment rate retrievals and the turbulent profiles derived from lidar observations.

Turner, David, D.; Ferrare, Richard, A.

2011-07-06T23:59:59.000Z

427

COBRA: A Computational Brewing Application for Predicting the Molecular Composition of Organic Aerosols  

Science Conference Proceedings (OSTI)

Atmospheric organic aerosols (OA) represent a significant fraction of airborne particulate matter and can impact climate, visibility, and human health. These mixtures are difficult to characterize experimentally due to the enormous complexity and dynamic nature of their chemical composition. We introduce a novel Computational Brewing Application (COBRA) and apply it to modeling oligomerization chemistry stemming from condensation and addition reactions of monomers pertinent to secondary organic aerosol (SOA) formed by photooxidation of isoprene. COBRA uses two lists as input: a list of chemical structures comprising the molecular starting pool, and a list of rules defining potential reactions between molecules. Reactions are performed iteratively, with products of all previous iterations serving as reactants for the next one. The simulation generated thousands of molecular structures in the mass range of 120-500 Da, and correctly predicted ~70% of the individual SOA constituents observed by high-resolution mass spectrometry (HR-MS). Selected predicted structures were confirmed with tandem mass spectrometry. Esterification and hemiacetal formation reactions were shown to play the most significant role in oligomer formation, whereas aldol condensation was shown to be insignificant. COBRA is not limited to atmospheric aerosol chemistry, but is broadly applicable to the prediction of reaction products in other complex mixtures for which reasonable reaction mechanisms and seed molecules can be supplied by experimental or theoretical methods.

Fooshee, David R.; Nguyen, Tran B.; Nizkorodov, Sergey A.; Laskin, Julia; Laskin, Alexander; Baldi, Pierre

2012-05-08T23:59:59.000Z

428

BASIS: Backscattering Spectrometer at SNS | ORNL Neutron Sciences  

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

Backscattering Spectrometer Backscattering Spectrometer View inside the BAIS tank View inside the BASIS tank. BASIS is a near-backscattering, crystal-analyzer spectrometer that provides very fine energy resolution, as low as 3.0 to 3.5 µeV at the elastic peak (depending on sample size). This requires a long initial guide section of 84 m from moderator to sample in order to achieve the timing resolution necessary for obtaining the desired energy resolution. BASIS provides an excellent dynamic range near the elastic peak of about plus and minus 100 µeV in the standard high-intensity operation regime, which, if needed, could be extended to plus and minus 200 µeV and beyond. The spectrometer is optimized for quasielastic scattering but provides about 0.1% resolution in energy transfers up to ~40 meV; the inelastic excitations need to be

429

The FIRE infrared spectrometer at Magellan: construction and commissioning  

E-Print Network (OSTI)

We describe the construction and commissioning of FIRE, a new 0.8-2.5?m echelle spectrometer for the Magellan/ Baade 6.5 meter telescope. FIRE delivers continuous spectra over its full bandpass with nominal spectral ...

Simcoe, Robert A.

430

Study of electromagnetic processes with the dielectron spectrometer HADES  

Science Conference Proceedings (OSTI)

Dielectron production in pp and dp reactions at 1.25 A.GeV has been studied with the High Acceptance DiElectron Spectrometer (HADES) at GSI. Results obtained in inclusive and exclusive channels are shown

B. Ramstein; The HADES collaboration

2010-01-01T23:59:59.000Z

431

An acousto-optical correlation spectrometer for radio astronomy.  

E-Print Network (OSTI)

??The objective of this thesis research is to develop and construct a wide-band, high resolution, two-channel prototype acousto-optic correlation spectrometer (AOCS) to analyze signals received… (more)

Cheung, Kwok-wai

1987-01-01T23:59:59.000Z

432

AN ENGINE EXHAUST PARTICLE SIZERTM SPECTROMETER FOR TRANSIENT EMISSION PARTICLE MEASUREMENTS  

DOE Green Energy (OSTI)

There has been increased interest in obtaining size distribution data during transient engine operation where both particle size and total number concentrations can change dramatically. Traditionally, the measurement of particle emissions from vehicles has been a compromise based on choosing between the conflicting needs of high time resolution or high particle size resolution for a particular measurement. Currently the most common technique for measuring submicrometer particle sizes is the Scanning Mobility Particle Sizer (SMPSTM) system. The SMPS system gives high size resolution but requires an aerosol to be stable over a long time period to make a particle size distribution measurement. A Condensation Particle Counter (CPC) is commonly used for fast time response measurements but is limited to measuring total concentration only. This paper describes a new instrument, the Engine Exhaust Particle SizerTM (EEPSTM) spectrometer, which has high time resolution and a reasonable size resolution. The EEPS was designed specifically for measuring engine exhaust and, like the SMPS system, uses a measurement based on electrical mobility. Particles entering the instrument are charged to a predictable level, then passed through an annular space where they are repelled outward by the voltage from a central column. When the particles reach electrodes on the outer cylindrical (a column of rings), they create a current that is measured by an electrometer on one or more of the rings. The electrometer currents are measured multiple times per second to give high time resolution. A sophisticated realtime inversion algorithm converts the currents to particle size and concentration for immediate display.

Johnson, T; Caldow, R; Pucher, A; Mirme, A; Kittelson, D

2003-08-24T23:59:59.000Z

433

AN ENGINE EXHAUST PARTICLE SIZER{trademark} SPECTROMETER FOR TRANSIENT EMISSION PARTICLE MEASUREMENTS  

DOE Green Energy (OSTI)

There has been increased interest in obtaining size distribution data during transient engine operation where both particle size and total number concentrations can change dramatically. Traditionally, the measurement of particle emissions from vehicles has been a compromise based on choosing between the conflicting needs of high time resolution or high particle size resolution for a particular measurement. Currently the most common technique for measuring submicrometer particle sizes is the Scanning Mobility Particle Sizer (SMPSTM) system. The SMPS system gives high size resolution but requires an aerosol to be stable over a long time period to make a particle size distribution measurement. A Condensation Particle Counter (CPC) is commonly used for fast time response measurements but is limited to measuring total concentration only. This paper describes a new instrument, the Engine Exhaust Particle SizerTM (EEPSTM) spectrometer, which has high time resolution and a reasonable size resolution. The EEPS was designed specifically for measuring engine exhaust and, like the SMPS system, uses a measurement based on electrical mobility. Particles entering the instrument are charged to a predictable level, then passed through an annular space where they are repelled outward by the voltage from a central column. When the particles reach electrodes on the outer cylindrical (a column of rings), they create a current that is measured by an electrometer on one or more of the rings. The electrometer currents are measured multiple times per second to give high time resolution. A sophisticated realtime inversion algorithm converts the currents to particle size and concentration for immediate display.

Johnson, T: Caldow, R; Pucher, A Mirme, A Kittelson, D

2003-08-24T23:59:59.000Z

434

ARM Aerosol Working Group Meeting  

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

and MFRSR Measurements ARM STM 2008 Norfolk, VA Connor Flynn 1 , Annette Koontz 1 , Anne Jefferson 2 , Jim Barnard 1 , Sally McFarlane 1 1 Pacific Northwest National Laboratory 2 CIRES, University of Colorado, Boulder Progress towards ARM DOE 2008 Performance Metric 3 & 4 * Produce and make available new continuous time series of aerosol total column depth, based on results from the AMF deployment in Niger, Africa. * Produce and make available new continuous time series of retrieved dust properties, based on results from the AMF deployment in Niger, Africa. 0 100 200 300 400 0 20 40 60 80 100 ITF movement and surface RH % RH day of year (2006) 0 100 200 300 400 0 50 100 150 200 250 300 350 day of year wind direction (N = 0, E = 90) 2 4 6 8 10 12 14 Wind speed m/s 0 100 200 300 1.4 1.6 1.8 2 MFRSR Vo for filter2, Niamey

435

ATMOSPHERIC AEROSOL SOURCE-RECEPTOR RELATIONSHIPS: THE ROLE OF COAL-FIRED POWER PLANTS  

Science Conference Proceedings (OSTI)

This report describes the technical progress made on the Pittsburgh Air Quality Study (PAQS) during the period of August 2001 through January of 2002. The major activity during this project period was the continuation of the ambient monitoring effort. Work also progressed on organizing the upcoming source characterization effort, and there was continued development of several three-dimensional air quality models. The first PAQS data analysis workshop for the project was held at Carnegie Mellon in December 2001. Two new instruments were added to site during this project period: a single particle mass spectrometer and an in situ VOC instrument. The single particle mass spectrometer has been deployed since the middle of September and has collected more than 150 days of data. The VOC instrument was only deployed during the intensive sampling period. Several instruments experienced operational issues during this project period. The overall data recovery rate for the project has been high.

Allen L. Robinson; Spyros N. Pandis; Cliff I. Davidson

2002-03-01T23:59:59.000Z

436

Lead Slowing Down Spectrometer Research Plans  

Science Conference Proceedings (OSTI)

The MPACT-funded Lead Slowing Down Spectrometry (LSDS) project has been evaluating the feasibility of using LSDS techniques to assay fissile isotopes in used nuclear fuel assemblies. The approach has the potential to provide considerable improvement in the assay of fissile isotopic masses in fuel assemblies compared to other non-destructive techniques in a direct and independent manner. The LSDS collaborations suggests that the next step to in empirically testing the feasibility is to conduct measurements on fresh fuel assemblies to understand investigate self-attenuation and fresh mixed-oxide (MOX) fuel rodlets so we may betterto understand extraction of masses for 235U and 239Pu. While progressing toward these goals, the collaboration also strongly suggests the continued development of enabling technology such as detector development and algorithm development, thatwhich could provide significant performance benefits.

Warren, Glen A.; Kulisek, Jonathan A.; Gavron, Victor; Danon, Yaron; Weltz, Adam; Harris, Jason; Stewart, T.

2013-03-22T23:59:59.000Z

437

ARM - Field Campaign - Carbonaceous Aerosol and Radiative Effects Study  

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

govCampaignsCarbonaceous Aerosol and Radiative Effects Study (CARES) govCampaignsCarbonaceous Aerosol and Radiative Effects Study (CARES) Campaign Links CARES Website Related Campaigns Carbonaceous Aerosol and Radiation Effects Study (CARES) - Surface Meteorological Sounding 2010.05.26, Zaveri, OSC Carbonaceous Aerosol and Radiation Effects Study (CARES) Photo-Acoustic Aerosol Light Absorption and Scattering 2010.05.26, Arnott, OSC Carbonaceous Aerosol and Radiative Effects Study (CARES): SMPS & CCN counter deployment during CARES/Cal-NEx 2010.05.04, Wang, OSC Carbonaceous Aerosol and Radiative Effects Study (CARES) Ground Based Instruments 2010.04.01, Cziczo, OSC Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Carbonaceous Aerosol and Radiative Effects Study (CARES)

438

Aerosol Data Sources and Their Roles within PARAGON  

Science Conference Proceedings (OSTI)

We briefly but systematically review major sources of aerosol data, emphasizing suites of measurements that seem most likely to contribute to assessments of global aerosol climate forcing. The strengths and limitations of existing satellite, ...

Ralph A. Kahn; John A. Ogren; Thomas P. Ackerman; Jens Bösenberg; Robert J. Charlson; David J. Diner; Brent N. Holben; Robert T. Menzies; Mark A. Miller; John H. Seinfeld

2004-10-01T23:59:59.000Z

439

Optical Properties of Atmospheric Aerosol in Maritime Environments  

Science Conference Proceedings (OSTI)

Systematic characterization of aerosol over the oceans is needed to understand the aerosol effect on climate and on transport of pollutants between continents. Reported are the results of a comprehensive optical and physical characterization of ...

Alexander Smirnov; Brent N. Holben; Yoram J. Kaufman; Oleg Dubovik; Thomas F. Eck; Ilya Slutsker; Christophe Pietras; Rangasayi N. Halthore

2002-02-01T23:59:59.000Z

440

ARM - Field Campaign - Two-Column Aerosol Project (TCAP): Aerial...  

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

Facility (AMF) and the Mobile Aerosol Observing System (MAOS) will be deployed on Cape Cod (MA) for a 12-month period starting in the summer of 2012 in order to quantify aerosol...

Note: This page contains sample records for the topic "aerosol mass spectrometer" 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

Light Extinction by Aerosols during Summer Air Pollution  

Science Conference Proceedings (OSTI)

In order to utilize satellite measurements of optical thickness over land for estimating aerosol properties during air pollution episodes the optical thickness was measured from the surface and investigated. Aerosol optical thicknesses have been ...

Yoram J. Kaufman; Robert S. Fraser

1983-10-01T23:59:59.000Z

442

Optical Properties of Aerosol Particles over the Northeast Pacific  

Science Conference Proceedings (OSTI)

In July 2002, atmospheric aerosol measurements were conducted over the northeast Pacific Ocean as part of the Subarctic Ecosystem Response to Iron Enhancement Study (SERIES). The following aerosol quantities were measured: particle number size ...

Julia Marshall; Ulrike Lohmann; W. Richard Leaitch; Nicole Shantz; Lisa Phinney; Desiree Toom-Sauntry; Sangeeta Sharma

2005-08-01T23:59:59.000Z

443

Experimental investigation of aerosol deposition on slot-and...  

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

Experimental investigation of aerosol deposition on slot-and joint-type leaks Title Experimental investigation of aerosol deposition on slot-and joint-type leaks Publication Type...

444

Quantifying and Minimizing Uncertainty of Climate Forcing by Anthropogenic Aerosols  

Science Conference Proceedings (OSTI)

Anthropogenic aerosols are composed of a variety of aerosol types and components including water-soluble inorganic species (e.g., sulfate, nitrate, ammonium), condensed organic species, elemental or black carbon, and mineral dust. Previous ...

J. E. Penner; R. J. Charlson; S. E. Schwartz; J. M. Hales; N. S. Laulainen; L. Travis; R. Leifer; T. Novakov; J. Ogren; L. F. Radke

1994-03-01T23:59:59.000Z

445

Overview of the Cumulus Humilis Aerosol Processing Study  

Science Conference Proceedings (OSTI)

The primary goal of the Cumulus Humilis Aerosol Processing Study (CHAPS) was to characterize and contrast freshly emitted aerosols below, within, and above fields of cumuli, and to study changes to the cloud microphysical structure within these ...

Larry K. Berg; Carl M. Berkowitz; John M. Hubbe; John A. Ogren; Chris A. Hostetler; Richard A. Ferrare; Johnathan W. Hair; Manvendra K. Dubey; Claudio Mazzoleni; Elisabeth Andrews; Richard L. Coulter; Yin-Nan Lee; Jasono Olfert; Stephen R. Springston

2009-11-01T23:59:59.000Z

446

Distinguishing Aerosol Impacts on Climate over the Past Century  

Science Conference Proceedings (OSTI)

Aerosol direct (DE), indirect (IE), and black carbon–snow albedo (BAE) effects on climate between 1890 and 1995 are compared using equilibrium aerosol–climate simulations in the Goddard Institute for Space Studies General Circulation Model ...

Dorothy Koch; Surabi Menon; Anthony Del Genio; Reto Ruedy; Igor Alienov; Gavin A. Schmidt

2009-05-01T23:59:59.000Z

447

Aerosol Impacts on the Microphysical Growth Processes of Orographic Snowfall  

Science Conference Proceedings (OSTI)

The Regional Atmospheric Modeling System was used to simulate four winter snowfall events over the Park Range of Colorado. For each event, three hygroscopic aerosol sensitivity simulations were performed with initial aerosol profiles representing ...

Stephen M. Saleeby; William R. Cotton; Douglas Lowenthal; Joe Messina

2013-04-01T23:59:59.000Z

448

Aerosol Impacts on the Diurnal Cycle of Marine Stratocumulus  

Science Conference Proceedings (OSTI)

Recent large-eddy simulation (LES) studies of the impact of aerosol on the dynamics of nocturnal marine stratocumulus revealed that, depending on the large-scale forcings, an aerosol-induced increase of the droplet concentration can lead to ...

Irina Sandu; Jean-Louis Brenguier; Olivier Geoffroy; Odile Thouron; Valery Masson

2008-08-01T23:59:59.000Z

449

A Critical Examination of the Observed First Aerosol Indirect Effect  

Science Conference Proceedings (OSTI)

The relative change in cloud droplet number concentration with respect to the relative change in aerosol number concentration, ?, is an indicator of the strength of the aerosol indirect effect and is commonly used in models to parameterize this ...

Hongfei Shao; Guosheng Liu

2009-04-01T23:59:59.000Z

450

Dynamical Effects of Aerosol Perturbations on Simulated Idealized Squall Lines  

Science Conference Proceedings (OSTI)

The dynamical effects of increased aerosol loading on the strength and structure of numerically simulated squall lines are explored. Results are explained in the context of RKW theory. Changes in aerosol loading lead to changes in rain drop size ...

Zachary J. Lebo; Hugh Morrison

451

Sensitivity of aerosol radiative forcing calculations to spectral resolution  

DOE Green Energy (OSTI)

Potential impacts of aerosol radiative forcing on climate have generated considerable recent interest. An important consideration in estimating the forcing from various aerosol components is the spectral resolution used for the solar radiative transfer calculations. This paper examines the spectral resolution required from the viewpoint of overlapping spectrally varying aerosol properties with other cross sections. A diagnostic is developed for comparing different band choices, and the impact of these choices on the radiative forcing calculated for typical sulfate and biomass aerosols was investigated.

Grant, K.E.

1996-10-01T23:59:59.000Z

452

Evaluation of the carbon content of aerosols from the burn- ing of biomass in the Brazilian Amazon using thermal, op- tical and thermal-optical analysis methods  

E-Print Network (OSTI)

Crutzen, P. : Atmospheric Aerosols: Biogeochemical sourcesof optically active aerosol particles over the Amazonproperties of Amazonian aerosol particles: Rev. Geophys. ,

Soto-Garcia, Lydia L.

2012-01-01T23:59:59.000Z

453

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

Science Conference Proceedings (OSTI)

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

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

1987-01-01T23:59:59.000Z

454

Toward a Minimal Representation of Aerosols in Climate Models: Comparative Decomposition of Aerosol Direct, Semidirect, and Indirect Radiative Forcing  

Science Conference Proceedings (OSTI)

The authors have decomposed the anthropogenic aerosol radiative forcing into direct contributions from each aerosol species to the planetary energy balance through absorption and scattering of solar radiation, indirect effects of anthropogenic ...

S. J. Ghan; X. Liu; R. C. Easter; R. Zaveri; P. J. Rasch; J.-H. Yoon; B. Eaton

2012-10-01T23:59:59.000Z

455

Emission-Induced Nonlinearities in the Global Aerosol System: Results from the ECHAM5-HAM Aerosol-Climate Model  

Science Conference Proceedings (OSTI)

In a series of simulations with the global ECHAM5-HAM aerosol-climate model, the response to changes in anthropogenic emissions is analyzed. Traditionally, additivity is assumed in the assessment of the aerosol climate impact, as the underlying ...

Philip Stier; Johann Feichter; Silvia Kloster; Elisabetta Vignati; Julian Wilson

2006-08-01T23:59:59.000Z

456

Discrete-element modeling of particulate aerosol flows  

Science Conference Proceedings (OSTI)

A multiple-time step computational approach is presented for efficient discrete-element modeling of aerosol flows containing adhesive solid particles. Adhesive aerosol particulates are found in numerous dust and smoke contamination problems, including ... Keywords: Aerosols, Aggregation, Particle adhesion, Particulate flow

J. S. Marshall

2009-03-01T23:59:59.000Z

457

Possible Aerosol Effects on Ice Clouds via Contact Nucleation  

Science Conference Proceedings (OSTI)

The indirect effect of aerosols on water clouds, whereby aerosol particles change cloud optical properties, is caused by aerosol-induced changes of the size and number of cloud droplets. This affects the lifetime of the water clouds as well as ...

Ulrike Lohmann

2002-02-01T23:59:59.000Z

458

Indirect and Semi-Direct Aerosol Campaign  

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

Campaign Campaign For the month of April, researchers are descending on and above Barrow, Alaska, to obtain data from the atmosphere that will help them understand the impacts that aerosols have on Arctic clouds and climate. Scientists sponsored by the U.S. Department of Energy's Atmospheric Radiation Measurement (ARM) Climate Research Facility are using a heavily instrumented aircraft to collect data from the sky, while instruments based at surface sites in Barrow and Atqasuk, Alaska, are obtaining measurements from the grou