Poly polymers for exfoliating and dispersingsolubilizing nanomaterial are provided herein. Digitized and compression encoded audio signals, stored in a semiconductor memory, are read out so as to undergo a decoding operation, which is an inverse operation to compression encoding, to reproduce the audio signals, and the reproduced signals are heard by the headphone. The oxide film that results from the oxidation of these films is relatively free from impurities. The method also includes the step of polishing the end face of the ferrule after the end of the optical fiber has been recessed. A plurality of shredders is mounted at the outlet end of the chute and is configured to shred and pick apart the insulation.