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
Stellar halo dominated by stars which formed within the galaxy, and an outer region primarily composed of stars accreted through merger events. Predictions for these components include different structure and rotation directions. Observational evidence for this dual halo in the Milky Way has been claimed but contested. Studies of the Milky Way galaxy have found that approximately 0.1-1% of its total stellar mass is contained within the stellar halo, and that it extends to over 100 kiloparsecs from the galactic centre. Stellar halo The stellar halo of a galaxy refers to the component of its galactic halo containing stars. The halo extends