Disclosed are methods of transferring heat to or from a fluid or body comprising causing heat to be transferred to or from a composition comprising at least one trifluoro, monochloropropene. The finisher determines when a trailing edge of the medium is about to leave a nip of the upstream rollers and then stops a leading edge of the medium. In one embodiment, a system comprises a series of gain stages each having at least one power adjustment circuit, such as at least one attenuator or amplifier.