Provided is a service access control system using an embedded browser agent. These systems may involve separating sample components by partitioning them into droplets or other partitions, amplifying or otherwise reacting the components within the droplets, detecting the amplified components, or characteristics thereof, andor analyzing the resulting data, among others. The clutch includes one or more pistons disposed within either the axle housing or a carrier supporting the input shaft bearing. A sequence of channel assignments is called optimal if it establishes a communications path from the first node in the sequence to the last node in the sequence, or, if such a path does not exist, from the first node to the farthest node possible in the sequence.