Disclosed is a method for improving power efficiency of subscriber stations in a communication network. At least some of the spacerspillars are coated on at least one surface thereof with a dry lubricant andor reflective material such as silver. Formulations using an optimal dose of oltipraz, which is provided by the invention, have a surprisingly good effect on the treatment and prevention of hepatic fibrosis and cirrhosis and are safe drugs that have a low toxicity on the human body. From this, a comparison is made between the energy of the residual voltage with a fractional energy of the 3rd harmonic neutral voltage. A surface of the semiconductor structure has flattened peaks. In preferred embodiment, the film further comprises a plurality of capillaries, which can originate in the base plane or in a secondary plane spaced from the base plane.