A method for unicast packet conversion whereby a unicast packet is received at a receiving node followed by a determination as to whether the destination address is identified in the packet. A circuit of the invention can include a pair of transistors serially coupled between a signal of relatively high voltage and a source of relatively low voltage, where a voltage of the signal of relatively high voltage can vary according to a voltage of a variable control signal. The capacitor dielectric layer covers the first capacitor electrode section. The predetermined condition can be one of several situations. Also provided is a method of vaporizing a liquid where a transport gas is used to carry a liquid in mist or droplet form through a heated boiler for vaporization.