Meanings

vortex device

regenerative blower

regenerative fan

exchange conference (e.g. cultural, educational, etc.)

as one would expect

flu shot

river rafting

epidemic keratoconjunctivitis

epidemic keratoconjunctivitis

selenium rectifier

distribution cost

influenza

rip current

rhyolite

to flow down

dam discharge (e.g. water)

flowing down (e.g. water in a river)

discharge water from a dam

excess current

discharged water