Abstract: In one embodiment of the present invention, a polygonal fuel cell comprises: a cathode layer having a tubular shape; a contact layer electrically coupled to and disposed on the cathode layer to leave an uncovered cathode surface portion; an electrolyte layer disposed on the uncovered cathode surface portion; and an anode layer electrically isolated from the contact layer, disposed on the electrolyte layer such that the polygonal fuel cell has a polygonal cross section to facilitate dense packing.

Abstract: In one embodiment of the present invention, a power controller for an AC load comprises: a user interface adapted to interact with a user to produce at least one user interface signal; and a control module adapted to electrically couple a line voltage supply, electrically couple the AC load, and provide electrical power to the AC load as a function of the at least one user interface signal by implementing a low-flicker, cycle-skipping control algorithm, the control algorithm comprising a plurality of cycle patterns, the cycle patterns comprising a plurality of main power levels.

Abstract: A method of detecting faults in a fuel cell system, the method comprising: comparing a plurality of fuel cell measurements to respective ones of a plurality of range limits to yield a plurality of range flags; differentiating the fuel cell measurements to yield a plurality of fuel cell rates; comparing the fuel cell rates to respective ones of a plurality of rate limits to yield a plurality of rate flags; and classifying the range flags and the rate flags to yield a fault detection decision.

Abstract: An apparatus for controlling a temperature of a thermal load comprises: a dynamic compensator for calculating a heater command as a function of a user input signal without using a temperature measurement; and a heater for controlling temperature of the thermal load by applying heat in response to the said heater command.

Abstract: A method of detecting faults in a fuel cell system, the method comprising: comparing a plurality of fuel cell measurements to respective ones of a plurality of range limits to yield a plurality of range flags; differentiating the fuel cell measurements to yield a plurality of fuel cell rates; comparing the fuel cell rates to respective ones of a plurality of rate limits to yield a plurality of rate flags; and classifying the range flags and the rate flags to yield a fault detection decision.

Abstract: In one embodiment of the present invention, a polygonal fuel cell comprises: a cathode layer having a tubular shape; a contact layer electrically coupled to and disposed on the cathode layer to leave an uncovered cathode surface portion; an electrolyte layer disposed on the uncovered cathode surface portion; and an anode layer electrically isolated from the contact layer, disposed on the electrolyte layer such that the polygonal fuel cell has a polygonal cross section to facilitate dense packing.

Abstract: In one embodiment of the present invention, an apparatus for controlling a temperature of a thermal load comprises: a dynamic compensator for calculating a heater command as a function of a user input signal without using a temperature measurement; and a heater for controlling said temperature of said thermal load by applying heat in response to said heater command.

Abstract: A fuel control system for controlling the ratio of ring temperature adjustment in rings of a combustor in a gas turbine. The fuel control system consists of employing a computer to perform the steps of; defining an operational boundary inner ring temperature adjustments versus outer ring temperature adjustments that defines a safe operating region for the annular combustor of the gas turbine; calculating a point of operation of the inner ring temperature adjustment versus the outer ring temperature adjustment within a safety margin of the operational boundary, wherein nitrous oxide (NOx) emission levels of the gas turbine is reduced; and regulating the ring temperatures to maintain a near global minimum point of operation, while maintaining normal operation of the gas turbine.

Abstract: An ultrasonic ranging system for providing a distance to a subject signal for use in positioning a movable imaging element support structure with respect to a subject of examination includes a collar assembly disposed around a portion of the imaging element structure disposed towards an imaging region; a plurality of ultrasonic transducers disposed in a sensing pattern around the collar assembly; and an ultrasonic ranging processing unit coupled to the transducers to control processing of ultrasonic ranging signals from the transducers. The transducers are typically disposed in one or more rows on the surface around the circumference of the collar assembly such that the lobes of ultrasonic signals generated provide a desired ranging field.

Abstract: A capacitive proximity detection system for positioning a movable radiation imaging element support structure with respect to a subject includes a plurality of sensor plates disposed in a collar assembly around a portion of an imaging component disposed towards a subject; a multiplexer coupled to the plurality of capacitive plate elements and adapted to selectively electrically couple the sensor plate elements in one of a plurality of sensing range modalities; and a capacitive sensing processor coupled to the sensor plate elements via the multiplexer so as to detect proximity of object to the sensor plate as a function of the capacitance between the sensor plates and the subject. The imaging system typically further includes a shield system coupled to the multiplexer and disposed so as to focus the capacitive sensing of the sensor plate elements towards the subject.