Abstract: A compressor system operable to shutdown in response to a shutdown signal. The compressor system includes a compression device operable between a first speed and a second speed to produce a flow of compressed fluid at a pressure. A blowdown valve is movable between a closed position and an open position in which at least a portion of the flow of compressed fluid passes through the blowdown valve to reduce the pressure of the flow of compressed fluid. A sensor is positioned to measure the pressure and a controller is operable to move the blowdown valve to the open position and set the speed of the compression device to a low set point speed in response to the shutdown signal.

Abstract: Sebum, the oily material secreted by the sebaceous glands, especially on the human face, is adsorbed by a thin layer of a pyrogenic colloidal silica of spherical shape and very small particle size. The pyrogenic colloidal silica has a high capacity for adsorbing the sebum and preventing it from exerting its oily effects on the skin. Free flow of sebum from the sebaceous gland is allowed but even in the cases of persons whose sebaceous glands are overactive, the skin is not excessively oily, due to the adsorption effects of the pyrogenic colloidal silica. The appearance of the facial skin of a user is improved, the surface of the skin is less apt to support harmful bacterial and fungal growth and, if make-ups containing dyes or pigments are employed, they are less apt to undergo color changes, due to the effects of oil thereon.