Nanotube ESD protective devices and corresponding nonvolatile and volatile nanotube switches. The propylene polymerization processes generally include contacting propylene and an amount of ethylene with a first metallocene catalyst and a second metallocene catalyst within a polymerization reaction vessel to form a propylene based polymer, wherein the amount is an amount effective to form the propylene based polymer including from about 2 wt. The thermal modification system may comprise one or more adjustable spacers to adjust a radiant energy flux from a thermal energy source to the radiation sensitive layer by adjusting a separation distance between the source and the layer. The alloy can preferably be used as a replacement material for Be-containing copper materials for the manufacture of disconnectable electrical connections or for the manufacture of tools and components for the offshore field and the mining industry.