In the traction apparatus, a control circuit has the following traction control process portions. The apparatus includes a control module configured to communicate with a host and receive readwrite commands for a storage device, and a protection module operating within the control module and configured to maintain a plurality of protection states for the partition and a plurality of allowable transitions between the protection states. The improved flow fields comprise three-dimensional open-cell foamed metals that are preferably plated with gold. The invention provides a method and a device that is capable of interlinking various optical andor electronic signals in a logically digital or analogous manner or to detect the course of optical signals by scanning.