A device for punching out tissue areas from bone has a blade whose circumferential cutting edge corresponds to the contour of a tissue area that is to be punched out. The method comprises injection of air with high velocityhigh kinetic energy into the kiln to reduce or eliminate stratification of kiln gases. In one particular application, access control may be provided for a digital data stream using a multi-chip access control scheme that relies on one chip to provide access control over a received digital data stream, with another chip utilized to process the digital data stream once authorized to do so. The collet and lock nut assembly can be easily assembled by inserting at least one retention tab within the groove of the collet, and then applying pressure to the collet such that the remaining retention tabs of the lock nut are received within the groove of the collet to place the assembly in a locked position. Instead, certain components of the virtual content are selected to be migrated to the target account until a maximum number of components are reached.