Abstract: Multi-layer papermaker's fabrics are provided which include in the bottom fabric layer pairs of cross machine direction yarns that are woven in the same shed so as to provide paired bottom fabric layer cross machine direction yarns. Typically, these paired yarns comprise two smaller yarns that replace what otherwise would have been a larger single yarn, thereby reducing the thickness, void volume and water carrying propensity of the fabric. These fabrics may include a relatively large number of cross machine direction yarns on the papermaking surface and/or a papermaking surface having single float machine direction knuckles, so as to provide a high level of fiber support and good papermaking qualities.

Abstract: The invention concerns a method and apparatus to synthesize a frequency employing digital phase words to represent successive phase values. A digital dither signal generator is used to generate a succession of dither words which are summed with the phase words to form address words. The address words are used to address a store to convert the address words to waveform values. The periodic quantisation noise introduced by the digital process is made more random by means of the dither words thereby reducing the quantisation noise components while accepting an increased total noise power. The synthesizer is of particular advantage when used to generate the reference frequency for a frequency multiplier implemented as a phase lock loop. By making the dither sequence repetition frequency outside the phase lock loop bandwidth, the spurious components are removed from the frequency range of interest.

Abstract: In a computerized tomographic radiographic apparatus a source of radiation projects radiation through a patient to be incident on at least some of a plurality of detector devices. To project the radiation from different directions the source moves relative to the body and also relative to the detectors to irradiate different detectors. Collimators, moving with the source, are provided to reduce the incidence of scattered radiation on the detectors. The collimators take the form of baffle plates which are arranged, to present substantially the same exit aperture to each detector despite the relative movement.

Abstract: Apparatus for detecting knots and the like in swan or planed timber comprising means for injecting light into the surface of the timber and means for detecting light emerging from the timber at a location spaced apart from the point or region of injection, a defect such as a knot in the timber, being indicated in dependence upon the amplitude or presence of the light emerging from the timber.

Abstract: A data processing arrangement includes first storage means having storage locations arranged in a plurality of rows and second storage means comprising a single column of locations, one location being provided in said second storage means for each row of the locations in said first storage means. In order that the data stored in the two storage means can be correlated such that a combination of the data held in various locations of the first storage means can be compared with a corresponding value in a location of said second storage means, there is provided means for shifting the data held in the first and second storage means, at individually controllable rates, along said rows and said column respectively.