Abstract: In the case of a method of producing aspherical optical surfaces of optical elements (1), in particular for use in microlithography for producing semiconductor elements, the optical element (1) is ground for example in the form of a meniscus. In a first method step, the optical element (1) is introduced into a basic form (2), which has a spherical form bed and is being held at a distance over the form bed (3). After that, an intermediate medium (6) is introduced in the basic form (2) between the optical element (1) and the form bed (3) and, subsequently the optical element (1) being removed together with the intermediate medium (6) from the basic form. Then, the spherical form bed (3) of the basic form (2) or a second basic form is transformed into an aspherical form bed (3?) computationally determined in advance.

Abstract: In the case of a method of producing aspherical optical surfaces of optical elements (1), in particular for use in microlithography for producing semiconductor elements, the optical element (1) is ground for example in the form of a meniscus. In a first method step, the optical element (1) is introduced into a basic form (2), which has a spherical form bed and is being held at a distance over the form bed (3). After that, an intermediate medium (6) is introduced in the basic form (2) between the optical element (1) and the form bed (3) and, subsequently the optical element (1) being removed together with the intermediate medium (6) from the basic form. Then, the spherical form bed (3) of the basic form (2) or a second basic form is transformed into an aspherical form bed (3?) computationally determined in advance.

Abstract: A process and apparatus for processing a shredder light fraction including multi-duct nozzle having at least an end section positionable within a metallurgical vessel containing a molten metal bath. The shredder light fraction may be fed into the molten metal bath while using only small quantities of carrier gas, e.g., air or nitrogen, and protective gas, e.g., hydrocarbon or inert gas. The shredder light fraction and the carrier gas may be injected into the molten metal bath as a main jet and oxygen may also be injected into the molten metal bath as a secondary jet. The primary jet and the secondary jet may be surrounded by a gas jet formed by the protective gas being injected into the molten metal bath.

Abstract: The invention relates to a mirror telescope for use in inaccessible assemblies such as in satellites. The primary mirror and the secondary mirror are made of the same material as are all components which fix and influence the distance. In this way, a mirror telescope is provided which maintains its optical characteristics without readjustment over a long period of time.

Abstract: A continuous casting plant includes supporting elements following a through-type mould and including the strand guideways. The elements are arranged within a cooling chamber and are fastened to a supporting structure so as to be adjustable relative to the through-type mould and relative to one another in the direction transversely to the longitudinal axis of the strand guideways. In order to be able to carry out an aligned adjustment between the mould and the supporting elements in a simple manner, with little work to carry out and even with the plant in operation, wherein the entry of the cooling chamber is avoided, at least one of the supporting elements is coupled with an adjustment means. This adjustment means is fastened to a supporting structure, directed outwardly from the cooling chamber and actuatable from outside of the cooling chamber.

Abstract: A continuous casting mould comprises a first mould part moulding the strand cross section and at least one second mould part arranged after the first part in the strand travelling direction. The second mould part is equipped with wall parts supporting the strand surface and getting into contact therewith. The wall parts are pressable against the strand surface by adjusting means. In order to provide a continuous casting mould which peripherally requires only little space, in which the adjustment force does not depend on the wear of the wall parts, and in which completely uniform adjustment forces and thus always the same wear occur over the length of the wall parts, the adjusting means are arranged so as to be parallel to the longitudinal axis of the strand with their longitudinal axes.

Abstract: An improved take-off device for a horizontal continuous-casting installation is provided. The arrangement comprises a frame and a mounting seated on rollers in the frame. The mounting is rotatable relative to the frame and supports the drive roll and its drive shaft, and a counter-pressure roll, which rolls preferably have counter-profiles corresponding to the cross section of the casting. The mounting comprises two concentrically arranged tubes which are sealed at their ends, thereby defining a cooling area therein. The adverse effects of gravity on casting quality may be mitigated by rotating the mounting relative to the frame, and locking it as a desired relative position, depending upon the cross-sectional configuration of the casting.

Abstract: A horizontal continuous casting plant includes a tundish for accommodating melt and at least one through-type mold fastened to the tundish. The tundish is placeable into a position in alignment with a stationary strand guideway and removable from this position, together with the mold. In order to provide a continuous casting plant in which the relative movement between the strand skin and the mold exactly has the desired course and extent, the through-type mold is fixable relative to the base without play in the longitudinal direction of its mold cavity.

Abstract: A driving roll stand to be used in a continuous casting plant includes a lower roll and an upper roll arranged one above the other. At least one of the rollers is drivable by a rotary drive. The lower roll is mounted at a support supported on a base, and the upper roll is mounted at a lever hinged to the support and pivotably movable by an adjustment drive. The adjustment drive is hinged both to an upper part of the support rising above the lever in height and to the lever. Further the rotary drive of the upper and/or lower roll is mounted at this upper part of the support.

Abstract: As the liquid crystal substance in electro-optical devices or as the stationary phase in gas chromatography is employed a compound of the formula ##STR1## in which R.sub.1 and R.sub.2 each is C.sub.n H.sub.2n+1 --, C.sub.n H.sub.2n+1 O--, C.sub.n H.sub.2n+1 COO-- or C.sub.n H.sub.2n+1 OCOO--, n being an integer of from 1 to 10, and R.sub.3 is Cl--, Br--, CH.sub.3 --, C.sub.2 H.sub.5 --, CH.sub.3 CO-- or CH.sub.3 OOC--.