An air stabilization system employing two parallel, opposite-facing Coanda nozzles, with each nozzle exhausting gas at opposite directions, subjects a moving flexible web to opposing forces effective to create local tension within the web. A pulse transmission receiver includes: a higher-order time derivative pulse correlator; a demodulation decoder coupled to the higher-order time derivative pulse correlator; a clock coupled to the demodulation decoder; and a pseudorandom polynomial generator coupled to both the higher-order time derivative pulse correlator and the clock. Received routing requests are parsed for subscriber identifiers that have assigned current rate decks. Vending equipment includes copiers, phones, facsimile machines, printers, data-ports, laptop print stations, notebook computers, palmtop computers, microfiche devices, projectors, scanners, cameras, modems, communication access, personal data assistants, pagers, and other vending machines, personal computers, PC terminals, and network computers. washing away cupric oxide generated in the oxidation step by means of an acidic cupric oxide cleaning solution containing diluted HF, NH4F or NH2OH; and.