= Joshua S. Méndez Harper
{c}
<Joshua S. Méndez Harper> studies electrostatic charging in <granular materials> through laboratory and field experiments. His Portland State profile connects frictional charging with phenomena ranging from clumping during grinding to electrical activity in volcanic plumes.https://www.pdx.edu/profile/joshua-mendez[Research description, frictional charging and sensing]{ref}
He also coauthored the generalized gas-discharge paper, contributing validation and formal analysis.<A Generalized Townsend's Theory for Paschen Curves in Planar, Cylindrical, and Spherical Geometries in Planetary Atmospheres by Jeremy A. Riousset and others>[Author contributions]{ref} Charging particles and initiating a discharge are distinct physical questions: collisions can create a distribution of charge, while the resulting <electric field> must still support ionization and current through the surrounding gas. Measuring both particle charge and discharge conditions therefore tests more than observing a visible spark.
\Image[https://s3-us-west-2.amazonaws.com/oam.pdx.edu/profiles/joshmen.png]
{title=Portrait of <Joshua S. Méndez Harper>}
{source=https://www.pdx.edu/profile/joshua-mendez}
{width=240}
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