Provided are low-cost, mechanically strong, highly electronically conductive porous substrates and associated structures for solid-state electrochemical devices, techniques for forming these structures, and devices incorporating the structures. An initial billing time that the at least one video program is to be billed associated with the at least one user account may be identified. The shaped articles can be fibers, fibrids, fibrous nonwoven webs, granules, beads, self-supporting films, tubular films, filaments, sponges, foams or bristles. The metal protective section includes a perimeter and an extension attached to the perimeter and shape to be removably engaged to the grooved opening in the frame. The circuit is configured to provide the differential output signal and the first and second fixed voltages to an indicator circuit configured to assert an indication responsive to detecting that a differential voltage of the differential output signal is greater than a differential voltage of the first and second fixed voltages.