A method and apparatus for processing a compressed video signal to remove blocking artifacts includes decompressing the video signal to provide a raw decoded signal and a quantisation parameter. A system is disclosed that includes a facility for creating a persona profile for an avatar in a first virtual world when the avatar wants to be teleported out of the first virtual world; a facility for transferring persona profiles to and from a disparate virtual world; and a facility for instantiating an inbound avatar based on a received persona profile. A hydraulic fracturing system may also force flow back water, produced water, or fresh water through a heat exchanger so that heat from the fracturing engines can be transferred to these liquids in order to vaporize them. The techniques include monitoring, at the controller, the rough road detection bit for a period to obtain a hysteresis band.