Abstract: Recorded features on a recording medium have inter-feature pauses between features and intra-feature pauses during features. In order to selectively replay the recorded features, the inter-feature pauses must be detected and reliably distinguished from the intra-feature pauses. An information signal indicative of the time duration of each pause is generated, and a tape speed signal indicative of the speed of the recording medium is generated throughout advancement of the latter. A decision time period is initially established as the standard for distinguishing between inter-feature and intra-feature pauses. The decision period is updated in response to changes in the advancement speed of the recording medium. The time duration of each pause is compared with the time duration of the updated decision period for generating an output control signal which controls the selective replay capability of the recording/reproduction system.

Abstract: Flame resistant acrylic fibers are produced by, in a solution polymerization of a mixture consisting of 30-80% by weight of acrylonitrile, 20-70% by weight of vinyl chloride or vinylidene chloride and 0-15% by weight of the other unsaturated monomer in a solvent of dimethylformamide, adding a polymer (referred to as blendmer) consisting of acrylonitrile, vinyl chloride or vinylidene chloride and an anionic monomer and zinc salt of an aromatic sulfonic acid prior to starting of the polymerization, subjecting the resulting mixture to the solution polymerization, removing unreacted monomers from the formed polymer solution, adding sulfur dioxide and adding water to adjust water content, spinning the thus formed spinning solution into an aqueous solution of dimethylformamide.