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Search Publications by: Robert A. Fletcher (Fed)

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Displaying 26 - 49 of 49

Verification of a Gas Mask Calibrant

February 19, 2007
Author(s)
Robert A. Fletcher, Jiann C. Yang, George W. Mulholland, R L. King, Michael R. Winchester, D Klinedinst, Jennifer R. Verkouteren, Thomas G. Cleary, David Buckingham, James J. Filliben

Reducing Uncertainty in Particle Size Measurement for Liquid Filter Testing

January 1, 2006
Author(s)
Barry M. Verdegan, Robert A. Fletcher
Contamination control is essential to reliable, cost-effective operation of hydraulic and engine systems. Particle counting provides the common, underlying basis for comparing filter performance and monitoring of contamination levels in hydraulic oil, lube

Polycyclic Aromatic Hydrocarbons in Flames, in Diesel Fuels, and in Diesel Emissions

December 1, 2005
Author(s)
R Dobbins, Robert A. Fletcher, Bruce A. Benner Jr., S Hoeft
Numerous chemical analyses of gaseous and particulate samples from laboratory flames provide a library of data on the polycyclic aromatic hydrocarbons (PAH) species found in diverse flame types burning fuels consisting of pure gaseous hydrocarbons. Diesel

IMS-Based Trace Explosives Detectors for First Responder Use

September 1, 2005
Author(s)
Jennifer R. Verkouteren, John G. Gillen, R M. Verkouteren, Robert A. Fletcher, E S. Etz, George A. Klouda, Alim A. Fatah, Philip J. Mattson
The purpose of this document is to establish minimum performance requirements and an associated test method for Ion Mobility Spectrometry (IMS) based trace explosives detectors for use by the first responder community. Information concerning the theory and

Polycyclic Aromatic Hydrocarbons in Flames, in Diesel Fuels, and in Diesel Emissions

January 1, 2005
Author(s)
Robert A. Fletcher, R Dobbins, Bruce A. Benner Jr, S Hoeft
Diesel fuels and emissions are composed of numerous hydrocarbon species. Combustion generated or pyrogenic polycyclic aromatic hydrocarbons (PAHs) derived from premixed and diffusion flames often consists of the most stable benzenoid PAHs. In contrast

Automated Analysis of Organic Particles Using Cluster SIMS

June 1, 2004
Author(s)
John G. Gillen, Cynthia J. Zeissler, Christine M. Mahoney, Abigail P. Lindstrom, Robert A. Fletcher, P Chi, Jennifer R. Verkouteren, David S. Bright, R Lareau, M Boldman
Cluster primary ion bombardment combined with secondary ion imaging is used in an ion microscope secondary ion mass spectrometer for the spatially resolved analysis of organic particles on various surfaces. Compared to the use of monoatomic primary ion

Soot Inception in a Well Stirred Reactor

March 19, 2003
Author(s)
L G. Blevins, K A. Jensen, R A. Ristau, N Y. Yang, C W. Frayne, R C. Striebich, M J. DeWitt, S D. Stouffer, E J. Lee, Robert A. Fletcher, J M. Oran, Joseph M. Conny, George W. Mulholland
Soot samples collected from a well stirred reactor operating with ethylene/air equivalence ratios of 1.9, 2.0, and 2.1 were examined to determine yield, size distribution, morphology, and composition. For F = 1.9, particles are absent. For F = 2.0 and 2.1

The Existence of Precursor Soot in the Exhaust of Inverse Diffusion Flames

October 1, 2002
Author(s)
L G. Blevins, Robert A. Fletcher, Bruce A. Benner Jr, Eric B. Steel, George W. Mulholland
Knowledge of the chemical and physical structure of precursor soot is useful in the development of soot particle inception models. This paper examines the hypothesis that soot exiting an inverse flame is similar in chemical and morphological structure to

Chapter 12: Analysis of Individual Collected Particles

January 1, 2001
Author(s)
Robert A. Fletcher, John A. Small, J H. Scott
This chapter describes microscopes and microprobes used for analysis of collected, individual particles. The instruments discussed are the light microscope, electron microscopes (scanning, environmental and transmission), electron microprobes, laser

Shape Factors of ISO 12103-A3 (Medium Test Dust)

November 1, 2000
Author(s)
Robert A. Fletcher, David S. Bright
A new derivative of Arizona sand, ISO Medium Test Dust, is coming into use as a liquid optical particle count calibrant. ISO Medium Test Dust and optical particle counters are used to test filtering efficiency. Particle shape plays a role in both filtering

SRM 2806 (ISO Medium Test Dust in Hydraulic Oil): A Particle-Contamination Standard Reference Material for the Fluid Power Industry

August 1, 1999
Author(s)
Robert A. Fletcher, Jennifer R. Verkouteren, Eric S. Windsor, David S. Bright, Eric B. Steel, John A. Small, Walter S. Liggett Jr
Standard Reference material (SRM) 2806 is composed of ISO medium test dust (ISO 12103-A3), a mineral dust, suspended in MIL-H-5606 hydraulic oil. SRM 2806 is a traceable particle count standard and is certified for number of particles larger than a

AMS and Microprobe Analysis of Combusted Particles in Ice and Snow

August 1, 1998
Author(s)
S R. Biegalski, George A. Klouda, R Weissenbok, Lloyd A. Currie, Robert A. Fletcher
Ice cores and snow pits of the cryosphere contain particles that detail the history of past atmospheric air compositions. Some of these particles result from combustion processes and have undergone long-range transport to arrive in the Arctic. Recent

Ultrafine Combustion Aerosol Generator

January 1, 1992
Author(s)
Thomas G. Cleary, George W. Mulholland, Lewis K. Ives, Robert A. Fletcher, J. W. Gentry
We are able to produce a narrowly distributed combustion aerosol with a mean particle size of about 10 nm by operating a laminar diffusion burner with acetylene fuel in the nominal "presooting" condition. Number concentrations of approximately 106

Analysis of Smoke Samples From Oil Well Fires in Kuwait. Report of Test (FR 3985)

June 20, 1991
Author(s)
George W. Mulholland, Bruce A. Benner Jr, Robert A. Fletcher, Eric B. Steel, Stephen A. Wise, Willie E. May, Daniel M. Madrzykowski, David J. Evans
This report describes results from a preliminary series of measurements concerning the smoke production from the Kuwait oil well fires. Detailed chemical analysis of the smoke is being carried out for determination of the fraction of ambient aerosol

Microchemical and Molecular Dating

March 1, 1989
Author(s)
Lloyd A. Currie, T. W. Stafford, A. E. Sheffield, George A. Klouda, Stephen A. Wise, Robert A. Fletcher, D. J. Donahue, A.J.T. Jull, T. W. Linick