Abstract: A feeding apparatus includes an upper movable carrier (1) having a plurality of guides or receptacles (7) which are transported at a predetermined speed and with a predetermined spacing along a predetermined path. The guides each have an open bottom and are each adapted to receive articles which are individually fed thereto. Over a first portion of its path, each guide (7) lies immediately above a lower carrier (11) which closes the bottom of and moves in synchronism with the guide (7), so as to allow one of the articles to become held within the guide (7) by the lower carrier (11) for a sufficient period of time as to allow the article to settle. Over a subsequent portion of the path, the guide (7) and the lower carrier (11) are separated from one another, thereby exposing the article on the lower carrier with accurately defined position and timing.

Abstract: In order to sort diamond-bearing ore particles conveyed on a wide belt, exciting radiation strikes the belt along an extended line. Diamonds are detected by passing the emitted radiation through a narrow band pass filter and sensing the Raman radiation with a photo-multiplier tube. Only axial-parallel rays passing through the filter reach the photo-multiplier tube. An array of side-by-side converging lenses can be used, the lenses being of rectangular shape as seen looking along the optical axis with their long axes at right angles to the line of radiation. The ore particles are in the plane of the foci of the lenses, so that radiation emitted by each particle is passed in parallel rays through the filter. In order to stop rays having an angle of incidence greater than the maximum permitted, to avoid identifying non-diamond material as diamond, a further converging lens is used to focus the rays at the plane of a telecentric stop. The stop stops rays having too great an angle of incidence.

Abstract: In order to provide an accurate sort into many different classes, objects are dropped through a viewing zone and viewed in the same instant by a number of viewers. Each viewer provides electronic signals representative of three basic shape features, namely blockiness, symmetry and convex hull deviance, together with a total count of edge-breakthroughs. For each basic shape feature, the maximum, minimum and mean are obtained for all the viewers, except the minimum convex hull deviance signal. These signals, together with the edge-breakthrough count, are each subjected to a linear transformation to provide a normalized shape parameter which is then assigned a value of 0 to 15 for each class being sorted on the basis of the expected occurrence of that parameter in that class. Each pair of secondary shape parameters so determined is used to derive from a respective table a decision value. The shape class of the object is ascertained on the basis of a majority vote for all the shape decision values.

Abstract: The present invention provides a P-N-P diamond transistor and a method of manufacture thereof. The transistor comprises a diamond substrate having two p-type semiconducting regions separated by an insulating region with an n-type semi-conducting layer established by chemical vapour deposition. Preferably the p-type regions are obtained by doping with boron and controlling the concentration of nitrogen impurities by the use of nitrogen getters. The n-type layer preferably contains phosphorus.

Abstract: A method and apparatus for determining the existence of misorientation in a crystal, comprising irradiating the crystal with X-rays pre-orientating any crystallographic plane of the crystal with respect to the axis of the X-rays, imaging X-rays received from the crystal so as to cause a plurality of effectively angularly-separated images to be formed, the energy of the X-rays being such that while carrying out the method at least some of the X-rays forming the images have intersected the whole depth of the portion of the crystal being examined, and determining the existence of any misorientation from the images.