Abstract: A cleansing and descaling agent is disclosed which includes citric acid and thickeners. The thickeners are chosen from a group including an alkyl alcohol ether-sulfate, an amphoteric surfactant, a nonionic surfactant, an amine or alkoxylated amine and a combination thereof. Additionally, additives such as salts and perfumes can be added. The present invention also includes a process for producing the present descaling agent and a process for using the present descaling agent.

Abstract: A power thyristor includes a semiconductor body having first and second main surfaces, the first main surface being planar; at least first and second metal electrodes disposed at least on the first main surface; the first electrode having a contact surface lying in a first plane parallel to the first main surface; the second electrode having a contact surface lying in a second plane parallel to the first main surface; the contact surface of the first electrode being further from the first main surface than the contact surface of the second electrode; the first electrode being formed of first and second layers and the second electrode being formed of a metal with a given thickness; the first layer being adjacent the first main surface and being formed of polycrystalline silicon; and said second layer being disposed on the first layer and being formed of the same metal with the same given thickness as the second electrode.