A magnetic memory device using magnetic resistance is provided. The invention also relates to a carbon fiber composite made by the process, a catalyst support, and a polymer electrolyte fuel cell. The system is particularly suited to efficiently automate the payment of a shipment transaction and to efficiently provide access to relevant shipment information. The control unit modifies the operation of the ventilator to compensate for the external gas flow rate such that the flow of gas reaching the patient is maintained at a desired level. The GUI may then selects order of the objects in the window by sorting the list by any of the columns. Then, the lower fin layer can be removed, while leaving the upper fin layer, thus yielding an interdigitated array of nitride columns and semiconducting fins suspended above the silicon surface.