Abstract: The method and apparatus of the invention simultaneously induces the same variable frequency mechanical vibrations in a test part and a standard. The vibrations of the two are converted to signals which are either displayed for comparison purposes or automatically analyzed for differences. Advantageously, the signals are electrical signals providing spectra which are analyzed for differences in amplitudes produced by the signals. Where the parts are separately supported, they are held with substantially the same force and are maintained against the vibration inducing mechanism with the same force. Where accelerometers are used, they are held with substantially the same force against the vibrating parts.

Abstract: A cylindrical branch connection fitting has an end adapted to be welded to a main pipe adjacent an opening therein with a pair of opposed ears and a pair of opposed crotches and a weld bevel extending outwardly from the inner edge of said end. A transition bevel extends from the center of each ear towards the centers of the crotches.

Abstract: Hologram apparatus for testing for defects in welds has a frame with means for supporting the frame. A laser beam is directed towards one end of the frame where it is reflected by a rotatable mirror onto an area of the weld lying in a predetermined direction within an arc of about 90.degree. extending from a point directly below the mirror. A head is mounted for rotation on said one end of the frame coaxially with the mirror. A photosensitive recording medium is mounted on the head for receiving laser light reflected from said weld. A reference beam mirror is mounted on the head for reflecting laser light from the rotatable mirror to the recording medium as a reference beam. The rotatable mirror and the head are interconnected to cause the ratio of the angular movement of the head to the angular movement of the rotatable mirror to be two to one.

Abstract: An improved gown belting means is described for back-closure gowns, or gowns commonly known as "sterile back" gowns, having one tie attached to the gown at the outer edge of a rear panel with an intermediate segment of the tie retained in a tunnel loop near the inner edge of the rear panel and a portion of the free end of the tie looped in a transfer tab, and a second tie attached to the gown at the inner edge of a second rear panel, having an intermediate segment releasably attached to the gown or held within a loop. The second tie has a free, unattached end retained at or above waist-level by the attached intermediate segment.

Abstract: Graphite products particularly suited for use in nuclear reactors are prepared by combining thermal petroleum pitch and particulated coke made from the same pitch into a moldable composition. The composition is molded into a desired shape. The shape is baked, impregnated with additional pitch, baked further, and then heated to temperatures sufficient to graphitize it. For nuclear applications a petroleum pitch low in sulfur content is preferred.