Abstract: .beta.-zinc diphosphide monocrystals (.beta.-ZnP.sub.2) (whiskers) having a diameter of at least 7 mm are made. To this end, a quartz ampoule is filled up to 70-90% its volume with polycrystalline .beta.-ZnP.sub.2 ; the ampoule is sealed and drawn in upright position at a velocity of 0.5-2.5 mm/day during a period of 24-120 days through a kiln; the temperature outline from below to above in the kiln is defined by a lower inlet temperature of 580.degree.-780.degree. C., a mean maximum temperature of 800.degree.-950.degree. C. and an upper outlet temperature of 350.degree.-400.degree. C.; the ampoule coming from the furnace is crushed and .beta.-ZnP.sub.2 condensed into a monocrystal via the gas phase by sublimation into the upper ampoule portion is removed.

Abstract: Crystalline lithium nitride, stable in air, characterized by a sodium content of less than 5.times.10.sup.-2 weight-percent, a potassium content of less than 10.sup.-2 weight-percent, a magnesium content of less than 1.times.10.sup.-2 weight-percent, and a silicon and iron content of 10.sup.-2 to 10.sup.-3 weight-percent each; is obtained by heating lithium having a purity of at least 99.9% in a vessel made of tungsten, niobium, ruthenium or tantalum in a nitrogen atmosphere at a pressure of at least 250 mm Hg in the absence of oxygen and water at a temperature of from 300.degree. C. to the melting point of lithium nitride.

Abstract: A pair of mating gears are mounted for rotation about respective axes in a gear-type fluid displacing pump or motor. Each gear has a pair of shaft portions at opposite axial ends of the respective gear, and bearing members surround respective ones of the shaft portions for journalling the gears. Each bearing member of one of the gears is juxtaposed with a respective bearing member of the other of said gears and, during rotation of the gears, the juxtaposed bearing members are subjected to forces which urge the bearing members to move relative to each other, particularly in direction towards each other. An arrangement is provided to counteract such forces and to oppose such relative movement of the juxtaposed bearing members.

Abstract: Neodymium ultraphosphates having the formulaMe.sub.x Nd.sub.1-x P.sub.5 O.sub.14wherein Me represents scandium, gallium, yttrium, indium, lanthanum, cerium, gadolinium, lutetium, thallium and/or uranium, and x is a number between 0 and 0.999, in the form of untwinned crystals, are prepared by heating Nd.sub.2 O.sub.3 and Me.sub.2 O.sub.3 in a vessel consisting of fine gold or of an inert, dense, carbon-based material with an excess of high-purity, anhydrous phosphoric acid or diphosphoric or polyphosphoric acid at a temperature between about 500.degree. and 600.degree. C, until the desired crystal size is achieved and then separating excess phosphoric acid or polyphosphoric acid, as the case may be.

Abstract: A gear pump or motor in which a pair of meshing gears are rotatably mounted in a housing and in which a throttle passage provides communication between a region of the housing in which, during rotation of the gears, high pressure is maintained and the region of the interstices between engaging teeth of the gears at which these interstices increase during such rotation, to prevent cavitation and to essentially reduce noise during operation.