Abstract: The present disclosure provides an orthodontic article including the reaction product of the polymerizable composition. Further, the present disclosure provides polymerizable compositions and methods of making an orthodontic article. The method includes obtaining a polymerizable composition and selectively curing the polymerizable composition to form an orthodontic article. Further, methods are provided, including receiving, by a manufacturing device having one or more processors, a digital object comprising data specifying an orthodontic article; and generating, with the manufacturing device by an additive manufacturing process, the orthodontic article based on the digital object. A system is also provided, including a display that displays a 3D model of an orthodontic article; and one or more processors that, in response to the 3D model selected by a user, cause a 3D printer to create a physical object of an orthodontic article.

Abstract: A system and method for high speed video tape reproduction wherein an optical disc player having two read heads located on opposite sides of the master disc is used to scan the individual tracks of the disc and develop electrical signals representing the data stored thereon. The two read heads are configured so that one head scans and reads even numbered tracks of the disc while the second head simultaneously scans and reads odd numbered tracks of the disc, which is being rotated at twice the standard rotational speed. The output electrical signals are then mixed and separated so that all data stored in a first portion of each track is formed into a first stream of electrical signals and all data stored in a second portion of each track is formed into a second stream of electrical signals. The two streams of electrical signals are then processed and delayed, as is necessary, so that the signals can be recorded by a video tape recorder having four write heads located around the circumference of its head drum.

Abstract: A multiple slave video tape reproduction system comprising: a master, including an optical disc player having two read heads located on opposite sides of the master disc for scanning the individual tracks of the disc and developing electrical signals representing the data stored, a timing means for coordinating the output sequence of the developed signals, and a processing means for configuring the developed signals so that they may be recorded onto a video tape; and a plurality of slave recorders, including a head drum, having four write heads located at 90 degree angles to each other around the circumference of the head drum whereby oppositely located heads form an electrically connected head pair, and mechanical and electrical components for moving and controlling the guide drum and tape.

Abstract: A coaxial RF connector adapted for mounting on a wall of a utilization device, such as a video disc player, employs a capacitor for providing DC and low frequency blocking between the wall of the device and the outer conductor of the connector. The capacitor is formed in the shape of a washer to provide a uniformly distributed capacitance around the outer conductor.

Abstract: An RF coaxial connector assembly, having an inner and outer conductor, employs a washer-like capacitor fitted over the outer conductor for low frequency isolation and employs a transformer adapted for connection between a source of RF signals and the inner and outer conductors of the assembly for reducing the RF currents on the outer conductor. Reduction of the RF currents on the outer conductor is effective to reduce the radiation of RF energy from a coaxial cable coupling the connector assembly to the load.