Abstract: With regard to a particularly precise measurement of a wavefront using structurally simple means, a method for measuring a curved wavefront using a wavefront sensor is specified, wherein a plurality of measurements are carried out at different positions along the wavefront using at least one wavefront sensor in order to determine a local gradient of the wavefront at the different positions, which method is characterized in that the plurality of measurements are carried out in each case with a substantially tangential alignment of a light entrance plane of the wavefront sensor(s) with the curved wavefront. A corresponding apparatus for measuring a curved wavefront using a wavefront sensor is also specified.

Abstract: Finely divided homogeneous powders of yttrium-stabilized, essentially quadratic zirconia have a narrow particle size distribution, and are prepared by (a) adjusting the pH of a mixed aqueous solution of zirconyl and yttrium acetates to a value of at least 5, (b) eliminating the solvent from such mixed aqueous solution, and (c) pyrolyzing the solid residue resulting from the step (b).

Abstract: Centralized greasing installation, each stage of which comprises a metering iston (12) with two rods (19, 20), the ends of each of the two rods (19, 20) sliding respectively inside a lubrication chamber (21) and a resetting chamber (22), said chambers being supplied with air and connected to the atmosphere by a bore (23, 24) of an adjusting stopper (17, 18) which is closed by the end of the corresponding rod at the end of corresponding lubrication and resetting travel of the piston (12), with means for detecting the establishment of pressure, wherein the various lubrication air chambers (21) are connected together and to a common air source having a limited flow rate as well as to a common pressure switch, while the various resetting air chambers (22) are placed in communication with each other and with another compressed-air source having a limited flow rate and to another pressure control switch, in order to verify, with limited means, that between the resetting phase and the lubrication phase, all the mete

Abstract: The invention relates to a method of preparing a product containing, as a single crystalline phase, a solid solution or .beta.'-sialon type having the general formula Si.sub.6-Z Al.sub.Z O.sub.Z N.sub.8-Z where Z=1 to 4, which comprises heating in a nitrogen atmosphere, at 1400.degree.-1600.degree. C., agglomerated elements obtained by drying a paste comprising a silico-aluminous material, such as kaolinitic clay, carbon, and a pore-generating agent comprised of fine particles of a ligneous material, such as sawdust or a powder of olive stones.

Abstract: Detergent compositions are provided in the form of inversed emulsions, wherein the continuous phase comprises a highly concentrated detersive surfactant and wherein the disperse phase comprises a highly concentrated electrolyte, preferably a detergency builder.