Abstract: An air quality control system for buildings with units, public corridors and an elevator shaft, has means for partitioning the public corridors into zones. Each of the zones have a first end in the vicinity of the partitioning means and a second end. Air inlet ducts are disposed in the vicinity of the second ends of the zones. Blower fans are disposed in the air inlet ducts for supplying fresh air to the zones. An exhaust duct communicates with the first ends of each of the zones for removing ambient air from the zones.

Abstract: A multi-story building structure includes at least one pair of levels. Each pair of levels includes one sleeping level, one living level and one public corridor on the living level. The levels include duplex apartments with at least one room on the sleeping level and at least one room on the living level of a respective pair of levels. An elevator system includes two elevators. Each of the elevators has a respective stop disposed at each one of the public corridors and each of the elevators skips the sleeping levels.

Abstract: A Two Cycle Safety Razor having a handle, platform, razor blade and cover plate. The platform having on its longer sides alternating teeth and slots preventing nicking of the shaven area from the blade edges. The alternating teeth and slots being of equal width. The razor assembly having a means to shift the blade the distance of one of said teeth, exposing at a slot a previously unused blade portion and simultaneously covering at a tooth a previously used blade portion, thereby utilizing a greater percentage of a razor blade's edge than heretofore obtained.