Abstract: An indoor unit of an air-conditioner having a unit body, provided on a rear of a ceiling, having an lower surface portion exposed indoor and an indoor heat exchanger and a blower in its exterior, a decorative panel, structured as the lower surface portion for the unit body, having an inlet port for guiding air in a room to the indoor heat exchanger, a filter fixing portion, structured as a part of the decorative panel, having a filter attached to a position opposite to the inlet port to be detachable, a support portion for supporting the filter fixing portion to be freely rotatable to the decorative panel, and an open/close driving mechanism for driving the filter fixing portion to be freely opened and closed against the decorative panel in a state that the support portion is used as a fulcrum, the mechanism for hanging the filter fixing portion from a ceiling surface when being opened to be moved.

Abstract: Automatic determination of the activated sludge volume index by use of a single sample is accomplished by a method which comprises placing in a test cell a mixed liquor of activated sludge sampled at the aerator outlet or at the final settler, automatically determining the concentration of activated sludge and the sedimentation rate of activated sludge by optical means and calculating the activated sludge volume index by subjecting the found values of activated sludge concentration and activated sludge sedimentation rate to an arithmetic circuit.