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Detailed Reference Information |
Chakrabarty, R.K., Moosmüller, H., Garro, M.A., Arnott, W.P., Walker, J., Susott, R.A., Babbitt, R.E., Wold, C.E., Lincoln, E.N. and Hao, W.M. (2006). Emissions from the laboratory combustion of wildland fuels: Particle morphology and size. Journal of Geophysical Research 111: doi: 10.1029/2005JD006659. issn: 0148-0227. |
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The morphology of particles emitted by wildland fires contributes to their physical and chemical properties but is rarely determined. As part of a study at the USFS Fire Sciences Laboratory (FSL) investigating properties of particulate matter emitted by fires, we studied the size, morphology, and microstructure of particles emitted from the combustion of eight different wildland fuels (i.e., sagebrush, poplar wood, ponderosa pine wood, ponderosa pine needles, white pine needles, tundra cores, and two grasses) by scanning electron microscopy. Six of these fuels were dry, while two fuels, namely the tundra cores and one of the grasses, had high fuel moisture content. The particle images were analyzed for their density and textural fractal dimensions, their monomer and agglomerate number size distributions, and three different shape descriptors, namely aspect ratio, root form factor, and roundness. The particles were also probed with energy dispersive X-ray spectroscopy confirming their carbonaceous nature. The density fractal dimension of the agglomerates was determined using two different techniques, one taking into account the three-dimensional nature of the particles, yielding values between 1.67 and 1.83, the other taking into account only the two-dimensional orientation, yielding values between 1.68 and 1.74. The textural fractal dimension that describes the roughness of the boundary of the two-dimensional projection of the particle was between 1.10 and 1.19. The maximum length of agglomerates was proportional to a power a of their diameter and the proportionality constant and the three shape descriptors were parameterized as function of the exponent a. |
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Keywords
Atmospheric Composition and Structure, Aerosols and particles (0345, 4801, 4906), Atmospheric Composition and Structure, Pollution, urban and regional (0305, 0478, 4251), Biogeosciences, Pollution, urban, regional and global (0345, 4251) |
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Publisher
American Geophysical Union 2000 Florida Avenue N.W. Washington, D.C. 20009-1277 USA 1-202-462-6900 1-202-328-0566 service@agu.org |
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