Abstract: A data communication method for transmitting a data packet from a transmitter to a receiver includes providing a key to the transmitter and the receiver where the key includes a K-bit data pattern sensitive to the location of each data bit in the data pattern; appending the key to the tail of the data packet; transmitting the data packet with the key; receiving data bits at the receiver to form a received data packet; retrieving K data bits from the tail of the received data packet; and determining if the K data bits match the key. If the K data bits match the key, a first output signal having a first state indicating that the data packet is acceptable is provided. If the K data bits do not match the key, the first output signal having a second state indicating that the data packet should be rejected is provided.

Abstract: A refrigeration device (10) including a generally cylindrical tank (11) including outer sidewalls (14) adapted to contain a first fluid. The device further includes a heat exchange fluid inlet (17) to the tank, a heat exchange fluid outlet (18) from the tank and a refrigeration unit (60). At least one hollow refrigeration evaporator coil (19, 20) is in fluid communication with the refrigeration unit by means of refrigerant feed and extraction pipes (61 and 62). The coil is helically disposed within the tank for freezing the first fluid adjacent the coil, such that in use the frozen fluid and the sidewalls together define a substantially helical path to direct the flow of a heat exchange fluid from the inlet to the outlet.

Abstract: A process is disclosed for forming high-performance high-voltage PNP transistors in a conventional monolithic, planar, PN junction isolated integrated circuit that contains high-performance NPN transistors. The process permits independently optimizing the NPN and PNP transistors.