Abstract: Y zeolites with an SiO.sub.2 /Al.sub.2 O.sub.3 ratio in the framework of>100 with a high hydrothermal stability and resistance to aqueous, alkaline solutions are produced by treating a Y zeolite with a SiO.sub.2 /Al.sub.2 O.sub.3 ratio between 8 and 50, partially dealuminized according to known methods from NaY zeolite by treatment with silicon tetrachloride, with water vapor at temperatures between 500.degree. C. and 1000.degree. C.

Abstract: Casting parameters in at least one of a feeding and mold-filling and squeezing phase are controlled during a casting step in a cold-chamber die-casting machine. The casting parameters are controllable as a function of travel of a casting piston longitudinally displaceable in a shot sleeve. The quantity of molten metal filled in within the shot sleeve is determined by precise metering using a stationary optical measuring device. The metering is accomplished by beaming a measuring beam through a filling port of the shot sleeve and reflecting the measuring beam on a surface of the molten metal. The transit time of the measuring beam and the reflected beam are measured to determine a filling level and quantity of molten metal filled in. A control system is provided which controls a movement of the casting piston and a start of each phase as a function of the filling level and the associated quantity of molten metal filled in.

Abstract: A method for the process control of a pressure diecasting machine, consisting of casting equipment (2) and a casting drive system (1), and an apparatus for carrying out the method are proposed. In order to regulate the movements both of the ram or drive plunger (8) in the pressing cylinder (7) and of the multiplier plunger (17) in the multiplier device (15) in each phase of the casting process, stepless devices (30, 31) measuring displacement and speed to determine the position or movements and also quick-adjustment servo-proportional valves (33 to 36) to regulate the movement both of the ram (8) and of the multiplier plunger (17) are provided.

Abstract: The subject of the invention is a mixture-compressing spark-ignition internal-combustion engine with a main combustion chamber and an auxiliary combustion chamber in the cylinder head. The auxiliary combustion chamber has a spark plug and is connected to the main combustion chamber by an overflow bore. The overflow bore is aligned with the piston crown in such a way that an emerging ignition jet aims at a surface region of the piston crown. According to the invention, the overflow bore is arranged concentrically with respect to the longitudinal center axis of the cylinder and the surface region of the piston crown is designed as an impact area lying opposite the bore and running orthogonally with respect to the jet direction.