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Photoacoustic microscopy of coal macerals

Conference · · Am. Assoc. Pet. Geol., Bull.; (United States)
OSTI ID:6576593
The application of photoacoustic microscopy to characterizing coal macerals will be presented. Photoacoustic microscopy can be used as an analytical tool that is responsive to the thermal-elastic properties of individual macerals. It is known that the photoacoustic signal is a function of the absorbing maceral's density, specific heat, and coefficient of linear expansion. The unique ability to probe the thermal-elastic properties of macerals is a principal advantage of photoacoustic microscopy when applied to the study of coal macerals. A standard reflectance microscope is modified to measure both the reflectance and photoacoustic data from the same macerals. Since reflectance depends on the optical parameters of the maceral, and the photoacoustic signal depends on the thermal-elastic properties of the maceral, the two measurements are complementary. Macerals which differ in density, specific heat, or linear expansion exhibit different photoacoustic responses, even though they may display the same optical properties. In this respect, photoacoustic microscopy offers a potentially valuable way of differentiating between macerals which have identical optical properties but different thermal-elastic properties. Data will be presented showing both the photoacoustic and reflectance measurments from different vitrinite macerals of the same sample, as well as from samples of different rank.
Research Organization:
Southern Illinois Univ., Carbondale
OSTI ID:
6576593
Report Number(s):
CONF-8310301-
Conference Information:
Journal Name: Am. Assoc. Pet. Geol., Bull.; (United States) Journal Volume: 67:9
Country of Publication:
United States
Language:
English