Methods and apparatus for providing and using a portable electronic data storage and information retrieval system for healthcare andor other types of applications are described. A LCD is also provided in the transparent fixing cover, and a rotary ringed stand is provided under the rotary disk. The outer core layer has an outer surface hardness less than the outer surface hardness of the inner core layer. A last stage is configured to produce output corresponding to the input. The command causes the switch to move to the off position moving a fuel control switch for the engine of the aircraft to a shut off position to stop the flow of fuel to the engine.