Abstract: To manufacture a channel-type waveguide pattern (1.1) having Y-shaped branches and a sharp vertex (V) on or in a substrate (1), masks (6 and 7) which partially overlap one another are used for two different etching steps, which successively define a part of the Y-shaped pattern. In this process, use is made of only one auxiliary mask layer (2) made of suitably chosen material which can be etched in the first etching step but is resistant in a second etching step involving dry etching.

Abstract: A process for the discoloration of animal blood in which whole blood or red blood corpuscles separated from whole blood by centrifugal action is carried in a fat milieu to which milk or vegetable protein is added and mixed. The mixture is then subjected to a considerable drop in pressure resulting in a reaction in which the red blood corpuscles are covered by a protein/fat film and thereby discolored. The drop in pressure is preferably in the order of 200-300 atmospheres and may take place in a homogenizer. The mixture of blood, fat, water and protein is preferably heated to a temperature in the range of 30.degree.-70.degree. before being fed to the homogenizer.