The present invention provides a mixer assembly including a mixer and a plurality of scoops attached around a circumference of the mixer element via a combination of sliding brackets and fixed brackets. A magnetic pattern bearing servo signals is provided on the guard bands formed on both sides of a data track of a magnetic recording medium. The address is supplied by the host computer to the NI device so that the NI device can DMA the data portions of the various packets directly into the destination. It is determined whether a predetermined period of time has elapsed since a first transmission of transaction data from the vending apparatus, and a communication request is transmitted upon such determination to a remote control center. The exposure system is provided with a vaporization preventing unit for preventing the vaporization of the liquid.