The power plant disclosed is an engine that derives is usefulness in the pursuit of energy generation by utilizing natural pressure differentials found in various liquids and gases, such as but not limited to water and air. In one embodiment, a sensing unit emits a chirp signal over a range of broadcast bands and monitors the output of the radio receiver to detect the frequency to which the radio receiver is tuned. A thin dielectric wall surrounds at least a portion of the interior chamber and has an external surface for contacting endometrial tissue. The ink container can supply ink to a corresponding print head or cartridge by means of a tube being connected with its ink outlet port. The invention enables a reduction of the time taken to perform administration and control operations for the group and reduces the risk of inconsistent specification of commands that can arise when a system administrator is required to repeat entry of a command several times. In addition, the current source provides an accurate adjustment to the write current because the temperature used by the temperature sensor to generate the output may be taken contemporaneously with generation of the write current.