Brush discharge plastics. The ability of an electrical discharge to cause an explosion in flammable atmospheres is measured by the "effective energy" of the discharge. The effective energy of brush discharges is 10-20 mJ, much larger than that of corona discharges 0.1 mJ. Therefore, brush discharges are considered an explosion hazard, while corona discharges are not. Brush discharges can occur from charged insulating plastics (for example polythene) to a conductor. Brush discharge A brush discharge is an electrical disruptive discharge similar to a corona discharge that takes place at an electrode with a high voltage applied to it, embedded in a nonconducting
Halo (religious iconography) the Middle Ages". This, by what the OED calls a "strange blunder", derived the word from the Latin "aura" as a diminutive, and also defined it as meaning a halo or glory covering the whole body, whilst saying that "nimbus" referred only to a halo around the head. This, according to the OED, reversed the historical usage of both words, but whilst Didron's diktat was "not accepted in France", the OED noted it had already been picked up by several English dictionaries, and influenced usage in English, which still seems to be the case, as the word "nimbus" is mostly