Abstract: A process has been developed for isolating aromatic dinitro compounds by using nitric acid in specified concentrations in different portions of a rectifying column and separating off the mixture of aromatic dinitro compounds from the sump of the rectifying column.

Abstract: A method and apparatus for controlling the real and reactive power behavior of a high voltage transmission (HDT) system characterized by a rectifier station connected to a first three phase network and an inverter station connected to a second three phase network. The rectifier and inverter stations have positive and negative station-halves connected to each other over positive and negative D.C. transmission lines to form positive and negative poles, each station having a common ground or return wire. Each station is equipped with current and voltage regulators, as well as control angle and quenching angle regulators whereby in case of the tripping of line protective devices monitoring line current in a faulty pole, and the consequent unloading of the faulty pole, the regulation of the intact pole assumes control for a short time to protect against network transients resulting from the load drop.

Abstract: Process for the preparation of 1-alkylamino-anthraquinones which comprises reacting 1-nitroanthraquinone with a monoalkylamine in the presence of an ether, a hydrocarbon or a mixture of an ether and a hydrocarbon. The 1-alkylamino-anthraquinones which are obtained can be employed directly as dyestuffs or used, without further purification, for the production of dyestuffs. Process of the invention results in the procurement of 1-alkylamine-anthraquinones of high purity and in high yield and avoids the formation of undesired by-products.

Abstract: The purification of high-melting organic products, such an anthraquinone and substituted anthraquinones, which is substantially free from lower-boiling impurities, by melting the product to be purified by heating, while mechanically conveying the same along a path with a screw conveyer, as for example, in a melting screw; degassing the melt at a reduced pressure in a column, as for example, at a pressure of 50 to 400 mm Hg; passing the degassed melt through a thin film evaporator at a reduced pressure of, for example, 5 to 250 mm Hg to evaporate the high-melting organic product and discharging the remaining high-boiling impurities and such impurities which are not capable of being distilled from the evaporator through a conically tapering sump, while mechanically scraping residue from the sump wall, preferably with the use of a rotating helical screw in the sump; the discharge from the sump being effected into and through an enclosed path at a rate sufficient to prevent liquid accumulating in the sump, while

Abstract: The invention relates to a manipulation device for precision adjustment of plane pattern bearing substrates being provided with two adjustment marks which are at different distances relative to a reference mark, which is, for example, a graduation plate. Such a substrate can be, for example, an intermediate negative or the like which is required in the course of a photolithographic mask production of integrated circuits. The manipulation device is constructed in such a manner that the pattern bearing substrate is substantially aligned relative to a reference mark by two orthogonal displacements and one rotation. This is accomplished by three displacement members which act upon a slide. Said slide, upon which the pattern bearing substrate is disposed, permits displacements parallel to the plane of the latter. Said displacement members are so arranged that the vectors of the orthogonal displacement actions pass one of the two adjustment marks.

Abstract: The present invention relates to an improved continuous process for the preparation of mononitro-aromatic compounds which comprises (1) nitrating a reactive aromatic compound in the absence of sulphuric acid until mono-nitration is essentially complete, said nitration being carried out in 40 to 68% strength by weight nitric acid, (2) separating mechanically the nitration reaction mixture into an inorganic phase and an organic phase, (3) washing of the organic phase with water and dilute alkali solution and subsequent separation of the unconverted starting material end of the adhering water by means of rectification (4) feeding the inorganic phase and, if necessary, the wash water of the first water wash of the organic phase, to a rectification column in which (a) water is withdrawn over the top (b) optionally a fraction which has a lower nitric acid content than the feed is withdrawn from a sidestream takeoff in the rectifying section of the column and (c) a fraction which has a higher nitric acid content tha

Abstract: .alpha.-Amino-.beta.'-nitroanthraquinone is prepared by reacting .alpha.,.beta.'-dinitroanthraquinone with ammonia in an ether, an aliphatic, a cycloaliphatic or an optionally alkyl-substituted aromatic hydrocarbon, water or a mixture of the foregoing.

Abstract: Aromatic mononitro compounds are prepared by nitrating aromatic compounds with nitric acid having a concentration between 70 and 100% by weight, working up of the nitration mixture in a rectification column and separation of the aromatic mononitro compound.In the nitration mixture and in the rectification column, depending upon the concentration of the nitric acid present, the ratio by weight of nitric acid plus water is controlled and not lowered below defined figures. Optionally water or nitric acid is introduced into the rectification column.

Abstract: Pure 1-nitroanthraquinone substantially free of dinitroanthraquinone is prepared by:1. Nitrating anthraquinone or a mixture which contains anthraquinone with at least 90% nitric acid at a temperature of at least 0.degree. C wherein the mole ratio of nitric acid to anthraquinone is less than 20 to 1;2. Stopping the reaction when the anthraquinone conversion is at least 50% by cooling the reaction mixture to a temperature of at most 20.degree. C and/or by adjusting the mole fraction of nitric acid in the reaction mixture to a value of at most 0.86;3. Precipitating 1-nitroanthraquinone by adjusting the mole fraction of nitric acid to a value of from 0.7 to 0.4 and/or by reducing the temperature to at most 20.degree. C; and4. Separating the precipitated 1-nitroanthraquinone and subjecting it to vacuum distillation.

Abstract: 1-Amino anthraquinone is prepared by reacting 1-nitro-anthraquinone with ammonia in water and/or an organic solvent and thereafter treating the 1-amino-anthraquinone imine formed with water thereby converting said imine into 1-amino anthraquinone.

Abstract: A mixture of dinitroanthraquinones of which at least 70% is 1,8-dinitroanthraquinone is dissolved at elevated temperature in a halogenated aromatic hydrocarbon, a carboxylic acid nitrile or a cyclic sulphone and is thereafter cooled selectively to precipitate substantially pure 1,8-dinitroanthraquinone. Preferred solvents are 1-chloronaphthalene, sulpholane and adipic acid dinitrile. The particular temperature of dissolution and cooling will depend upon the particular solvent.

Abstract: A mixture of dinitroanthraquinones of which at least 35% is 1,5-dinitroanthraquinone is dissolved at elevated temperature in a halogenated aromatic hydrocarbon, a carboxylic acid nitrile or a cyclic sulphone and is thereafter cooled selectively to precipitate substantially pure 1,5-dinitroanthraquinone. Preferred solvents are 1-chloronaphthalene, sulpholane and adipic acid dinitrile. The temperature of dissolution ranges from about 120.degree. C up to the boiling point and cooling is by about 10.degree. to 200.degree. C to a temperature not below about 0.degree. C.

Abstract: 1-AMINO- AND/OR 1,5- AND/OR 1,8-DIAMINO AND/OR 1-AMINO-6-NITRO AND/OR 1-AMINO-7-NITRO-ANTHRAQUINONE ARE PREPARED BY REACTING 1-NITRO- AND/OR 1,5- AND/OR 1,8- AND/OR 1,6- AND/OR 1,7-DINITRO-ANTHRAQUINONE WITH AMMONIA IN THE PRESENCE OF A NITRILE.

Abstract: Process for the preparation of 1-nitroanthraquinone by nitration of anthraquinone in the presence of highly concentrated nitric acid, characterised in that nitration is carried out at temperatures of 20.degree. to 80.degree.C, the reaction is terminated by lowering the nitric acid molar fraction in the reaction mixture to .ltoreq.0.85 by distilling off concentrated nitric acid and 1-nitroanthraquinone is precipitated by subsequently adjusting the nitric acid molar fraction to .ltoreq.0.7 to 0.4 and is separated off in a manner which is in itself known.

Abstract: A double-pole high-voltage direct-current transmission system is provided with two stations and an overhead line or cable, each of the stations having rectifier bridges connected in series from a positive line pole to a ground electrode and from the ground electrode to a negative line pole. The ground or earth serves as return line if one of the line poles should fail. The ground electrode at one of the stations is a depth electrode regularly operated as an anode, and the ground electrode at the other of the stations is regularly operated as a cathode. Two pairs of reversing switches are provided, each of the pairs, when the other of the stations is operated as a rectifier, being connected on the direct-current side of and to the respective rectifier bridges located between the negatively operated line pole and the depth electrode, on the one hand, and between the negatively operated line pole and the ground electrode operated as a cathode, on the other hand.

Abstract: A method and apparatus for regulation of the power factor of a 3-phase network fed with power from another 3-phase network via a short high-voltage direct current transmission link interconnecting the two networks. The d.c. transmission link includes rectifier and inverter stations connected at opposite ends of the link and the inverter station is controlled in such manner as to supply power to the fed network at a variable leading power factor in dependence upon the actual power factor of the fed network.

Abstract: A transmission substation for transforming a high D.C. voltage over an intermediate three phase A.C. network into a lower D.C. voltage. The substation includes an arrangement of inverters and rectifiers for effecting the transformation with reduced losses. Also encompassed is a similar reversed arrangement for stepping up from a lower D.C. voltage to a higher D.C. voltage.

Abstract: A multi-purpose funnel with handle, a flanged rim to prevent overflow and a discharge spout. The funnel comprises two co-axial connections with male thread, the smaller diameter connection having a tubular extension and a rubber seal. Discharge pipes are provided, there pipes can be bushed into the connection spout.

Abstract: Process for the preparation of 1-aminoanthraquinone by reaction of 1-nitroanthraquinone with ammonia in organic solvents, characterised in that the reaction is carried out in ethers, aliphatic or cycloaliphatic hydrocarbons or optionally alkyl-substituted aromatic hydrocarbons.

Abstract: Process for the preparation of 1,5- and/or 1,8-diaminoanthraquinone by reaction of 1,5- and/or 1,8-dinitroanthraquinone with ammonia in organic solvents, characterised in that the reaction is carried out in ethers, aliphatic or cycloaliphatic hydrocarbons or optionally alkyl-substituted aromatic hydrocarbons or in mixtures of these compounds.