A method for generating refrigeration for application to a heat load, especially at very cold temperatures, using an environmentally benign working gas such as air and using an upstream precooling circuit to reduce or eliminate inefficiencies stemming from warm end pinch. A switching device is formed over a substrate and then an insulating layer is formed over the substrate to cover the switching device. The outer ring may be rolled over itself and around the annular axis to retract the sleeve with sufficient force to stretch the incision to the desired diameter. Each parameter is assigned to a group as a function of the level of change of the performance characteristic from one value of the parameter to another. Meanwhile, one embodiment waits for auction completion and automatically consummates transactions for the highest above asking price bid or bids but at any point in time during the auction, short-bids andor acceptable bids so far may be consummated before the auction ends. Such compounds may, for example, be useful medicament.