Disclosed are copolymers derived from copolymerization of from about 50 to about 70 weight % of methyl acrylate; from about 0. Preferably, the particle size is in a range of approximately 5 m to 20 m and the powdered free silver is added in a concentration of approximately 5% to 10%. The special purpose entity may be a legal entity owned under tax accounting rules by a landlord of the space. The detector is adapted to provide a metric indicative of relative motion between the fixed portion and the first portion.