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Updated: Feb 8, 2026

Experimental Protocol to Investigate Particle Aerosolization of a Product Under Abrasion and Under Environmental Weathering
Published on: September 16, 2016
Experimental demonstration that a free-falling aerosol particle obeys a fluctuation theorem
Chun-Shang Wong1, J Goree1, Ranganathan Gopalakrishnan2
1Department of Physics and Astronomy, The University of Iowa, Iowa City, Iowa 52242, USA.
Abstract:
We investigate the fluctuating motion of an aerosol particle falling in air. Using a Millikan-like setup, we tracked a 1-μm sphere falling at its terminal velocity. We observe occurrences of particles undergoing upward displacements against the force of gravity, so that negative work is done briefly. These negative-work events have a probability that is shown to obey the work fluctuation theorem. This experimental confirmation of the theorem's applicability to aerosols leads us to develop and demonstrate an application: an in situ measurement of an aerosol particle's mass.
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