Abstract: There is provided a process for tanning animal hide comprising treating an animal hide with at least one tanning agent and exposing the treated hide to a dose of ionising radiation of from 1 to 500 kJ/kg wherein the ionising radiation is in the form of a charged particle beam.

Abstract: A method is provided for producing deep substantially vertical structures in silicon substrates, wherein in a first step, the silicon substrate is anisotropically plasma etched to a first predetermined depth, thereby creating a first structure. Subsequently, the surface of the substrate is covered conformally with an etch-resistant coating, and the horizontal parts of said coating are selectively removed. Following this removal, the substrate is anisotropically plasma etched at low temperatures to a second predetermined depth with a mixture of SF.sub.6 /O.sub.2, whereby a second structure is created. Finally, the vertical parts of the coating are removed.

Abstract: A reduction of the voltage across the electrolysis cell in which hydrogen is produced in the sulfuric acid hybrid closed cycle process by use of an electrolysis cell having an intermediate chamber between the anode and cathode chamber through which a separate electrolyte is caused to flow, is obtainable under operation with the electrolytes in both the cathode and the anode chambers having a concentration of sulfuric acid by weight of about 50% or more. It is found that the undesired formation of hydrogen sulfide and of sulfur remains at a tolerable small level if the catholyte is continuously renewed. A low specific resistance cation membrane is preferably used between the cathode and intermediate chambers, as well as between the anode and intermediate chambers.

Abstract: The production of hydrogen by electrolysis in a cell, in which the anode electrolyte contains sulfur dioxide as well as sulfuric acid and an intermediate chamber separated from the anode and cathode chambers by cation-exchanger membranes is provided through which an electrolyte flows in order to prevent sulfur dioxide from reaching the cathode chamber is greatly improved by using as the anode side membrane a cation-exchanger in which a polyvinyl chloride skeleton is combined with a polymer of styrol and divinyl benzol to which sulfonic acid groups have been attached, such a membrane having a very low resistivity, thus reducing the necessary electrolysis voltage. Such a membrane also loses conductivity with increasing sulfuric acid concentration at a lower rate than membranes previously used in such an electrolysis process and permits a higher sulfuric acid concentration in the anode electrolyte.