Abstract: A method and an apparatus for measuring the velocity and/or length of endless webs of textile goods are described. The textile web is irradiated with a light beam of which one deflects a first portion prior to impinging on the surface of the textile web and one directs the deflected light beam to evaluation means. The light beams reflected from the surface of the textile web are directed through a convex lens and are also directed to the evaluation means so that the corresponding light beams are superimposed. The velocity and/or the length of the web of textile goods are determined from the frequency of the interference formed by the superposition of the light beams.

Abstract: A dialysis process, wherein a fermented beverage obtained by a customary process is being conducted along one side of the dialysis membrane, with a suitable dialysate fluid containing extract substances (alcohol-free fruit beverage and a fermented beverage from which the alcohol has been removed) flowing on the other side, will simultaneously yield two marketable finished drinks of low alcohol content. To improve the alcohol-reduced beverage, the extract-containing fluid will, in given instances, be conducted in circulation and the alcohol be removed from the dialysate by vacuum distillation.

Abstract: Fermented beverages of a reduced alcohol contents are made by causing the fermented beverage having a normal alcohol contents as produced in the fermentation to flow along one face of a dialysis membrane at a pressure differential below 5.0 bar while simultaneously a dialysate liquid which is substantially alcohol-free is passed along the other face of the dialysate membrane. An apparatus for carrying out the process comprises a housing in which two separate chambers are provided. Each chamber has separate inlet and outlet ducts. The inlet ducts are connected to separate feeding devices for liquids. Separate regulating devices are arranged for regulating the flow through each of said two chambers and means are provided for regulating the pressure differential between the two chambers.

Abstract: A method for the bubble-free feed of gaseous reactants of a chemical and/or biological reaction into a liquid reaction medium, characterized by filling the pores of a porous polymer membrane with the reaction medium, providing one side of the porous polymer membrane with the gaseous reactants, and immersing the other side of the porous polymer membrane into the liquid reaction medium. The pressure of the gaseous reactants should lie below the bubble pressure determined for the reaction medium, but be at least so great that the liquid reaction medium does not pass through the porous polymer membrane to the gas side. Preferred parameters include relative pore volume between 50 and 90%; maximal pore diameter between 0.2 and 3 .mu.m; and disposing the porous polymer membrane in the form of a flat membrane, tube or hollow filaments.