Abstract: An improved hydraulic control valve is disclosed for providing the metering of fluid to a steering arrangement such as that normally employed on a motorized vehicle. The steering arrangement includes a piston-cylinder assembly, a main pump for supplying pressurized fluid from a fluid reservoir to the control valve and a control pump connected to the control valve which is actuated by a manually operated steering mechanism. The improved control valve includes a housing having an elongated bore formed therein. Movably positioned within the bore is a valve spool which has at least three annular grooves formed thereon separated by a pair of lands. The valve spool also contains a longitudinal bore formed therein which intersects a transverse bore which opens into the centrally positioned annular groove. The valve spool cooperates with the elongated bore to form control pressure chambers at each end thereof.

Abstract: Blowdown device for steam power plants includes a tube extending into a volume of water, the tube being formed with a multiplicity of holes having a substantially uniform diameter for introducing, into the water, steam that is flowing in the tube, the holes being disposed in rows spaced one from another a distance equal to at least 2.5 times the diameter of the holes.

Abstract: A photographic material with at least one light-sensitive silver halide emulsion is disclosed. The emulsion has been prepared by carrying out the precipitation of the silver halide in the presence of certain imidazoles.

Abstract: Automatic recalibration and testing of the accuracy of an analog-to-digital converter is accomplished in a converter of the type that compares the analog input signal with a linearly changing ramp referene signal and measures the time interval required for the magnitude of the reference signal to reach the level of the analog input signal from an initial level. In the invention, the linearly changing ramp reference signal is allowed to continue beyond the end of the converter's measuring phase and is thereupon compared with a datum voltage by a comparator which determines when equality between the two occurs. At the end of the measuring phase, a control pulse of fixed duration is generated and if the time of occurrence of equality is within the duration of that pulse, the converter is then operating within a suitable range of accuracy.

Abstract: A black and white developer solution containing o- or p-N-(2-hydroxyethyl)aminophenol as developer substance and a piperazine derivative of the formula ##STR1## in which R.sub.1, R.sub.2 and R.sub.3 denotes substituents as described hereinafter capable of developing a certain quantity of film e.g. 10 roll films per liter successively to substantially constant gamma values.

Abstract: High sensitive silver halide emulsions are obtained by the production of a new kind of sensitivity nuclei which are called troglodyte nuclei and which are described hereinafter.

Abstract: Uranium dioxide powder is prepared by the AUC (ammonium uranyl carbonate) method. Supplementing the known process steps, the AUC, after separation from the mother liquor, is washed with an ammonium hydrogen cabonate or an NH.sub.4 OH solution and is subsequently post-treated with a liquid which reduces the surface tension of the residual water in an AUC. Such a liquid is, for instance, alcohol.