Abstract: A measuring system monitors a spindle. The measuring system includes a cylindrical housing which can be arranged in and mechanically firmly connected to a spindle housing. A carrier ring is arranged inside the cylindrical housing. Three sensors for measuring a radial displacement and three sensors for measuring an axial displacement of the spindle are distributed over a circumference of the carrier ring. The sensors are cast with the carrier ring.

Abstract: A measuring system monitors a spindle. The measuring system includes a cylindrical housing which can be arranged in and mechanically firmly connected to a spindle housing. A carrier ring is arranged inside the cylindrical housing. Three sensors for measuring a radial displacement and three sensors for measuring an axial displacement of the spindle are distributed over a circumference of the carrier ring. The sensors are cast with the carrier ring.

Abstract: The present invention relates to a process for the thermal isomerization of a mixture of all-E-lycopene and its Z isomers of any composition to increase the proportion of all-E, wherein the isomerization takes place in a polar solvent in which lycopene is only slightly soluble.

Abstract: The thermal isomerization of lycopene The present invention relates to a process for the thermal isomerization of a mixture of all-E-lycopene and its Z isomers of any composition to increase the proportion of all-E, wherein the isomerization takes place in a polar solvent in which lycopene is only slightly soluble.

Abstract: A process for the preparation of 1,1,4,4-tetramethoxy-2-butene by reacting 2,5-dimethoxydihydrofuran with methanol in the presence of acids comprises carrying out the reaction in the presence of solid catalysts having acidic centers.

Abstract: The invention relates to a process for the purification of phosphonium salts in which a solution of the crude phosphonium salt is passed over a bed of a cation exchange resin in salt form or of an adsorber resin, the resin is washed with a polar protic solvent in the case of the cation exchange resin and with an electrolyte solution and a nonpolar solvent in the case of the adsorber resin, and the phosphonium salt is eluted from the cation exchange resin with an electrolyte solution or from the adsorber resin with a polar solvent.

Abstract: Phosphonium salts are prepared by reacting an alkanol with triarylphosphine and sulfonic acids in a solvent.

Abstract: The invention relates to a process for the purification of phosphonium salts in which a solution of the crude phosphonium salt is passed over a bed of a cation exchange resin in salt form or of an adsorber resin, the resin is washed with a polar protic solvent in the case of the cation exchange resin and with an electrolyte solution and a nonpolar solvent in the case of the adsorber resin, and the phosphonium salt is eluted from the cation exchange resin with an electrolyte solution or from the adsorber resin with a polar solvent.

Abstract: A process for the preparation of 1,1,4,4-tetramethoxy-2-butene by reacting 2,5-dimethoxydihydrofuran with methanol in the presence of acids comprises carrying out the reaction in the presence of solid catalysts having acidic centers.

Abstract: Phosphonium salts are prepared by reacting an alkanol with triarylphosphine and sulfonic acids in a solvent.

Abstract: Phosphonium salts are prepared by reacting an alkanol with triarylphosphine and sulfonic acids in a solvent.

Abstract: A process for preparing phosphonium salts of the general formula I in which the substituents have the following meanings, independently of one another: R aryl; X anion of an organic or inorganic acid selected from the group consisting of hydrohalic acids, sulfuric acid, sulfonic acids, phosphoric acid and C1-C6-alkanoic acids, by reacting 3,7,11-trimethyldodeca-1,4,6,10-tetraen-3-ol of the formula II with triarylphosphane and organic or inorganic acids selected from the abovementioned group, wherein in a two-stage process a) initially a tertiary phosphonium salt of the formula III  in which the radicals R and X have the abovementioned meanings, is prepared at temperatures in the range from −20 to 40° C., and b) the tertiary phosphonium salt of the formula III which is formed is rearranged to the primary phosphonium salt of the formula I at temperatures in the range from 40 to 100° C.

Abstract: A process for the preparation of 1,1,4,4-tetramethoxy-2-butene by reacting 2,5-dimethoxydihydrofuran with methanol in the presence of acids comprises carrying out the reaction in the presence of solid catalysts having acidic centers.

Abstract: Phosphonium salts are prepared by reacting an alkanol with triarylphosphine and alkyl or trifluoromethane sulfonic acids in a solvent.