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Measurements were made of the velocities of longitudinal ultrasonic waves of frequency 2.5 MHz and selected parameters describing the coal extract structure, such as mean molecular mass, aromaticity factor and concentration of unpaired spins, for the tetrahydrofuran (THF) extract of Indian sub-bituminous Assam coal. The sample of Assam coal (carbon content 80.4 wt%) was collected from the Gondwanaland...
The velocities of longitudinal ultrasound waves of frequency 2.5 MHz were measured in the temperature range 15-40°C in solutions of pyridine extracts from bituminous coals with carbon contents from 75.1 to 85.6 wt%. Mean molecular masses and aromaticity factors were also determined for the extracts. Parthasarathy rules were applied to verify relations between ultrasonic velocity and values of the...
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