Abstract: A system for controlling dispensation of multiple component reactant mixtures. A mixing chamber is positioned adjacent to a part. A metering ram is actuated to pressurize at least two reactant components. The metering ram is stopped if a measured pressure value exceeds a predetermined pressure value. At least one flow meter measures a volume of a reactant component passing through the system.

Abstract: A movable, prefabricated wall panel having a rigid rectangular frame. A core structure is disposed in the region bounded by the frame, which core structure preferably comprises at least one honeycomb layer. Sheetlike skins are fixedly secured to opposite sides of the frame and extends across the region bounded by the frame for confining the honeycomb layer therebetween. A plurality of small openings are formed in either or both of the skins so that they communicate with cells of the honeycomb layer to create Helmholtz sound-absorbing chambers. Each sheetlike skin is covered by a layer of porous fiberglass material for absorbing sound, which layer includes an inner thin mat of high-density fiberglass which is in turn covered by a relatively thick outer layer of low-density fiberglass. This outer layer has a variable density gradient across the thickness thereof, which density gradient progressively increases across the thickness toward the mat.