A proton conducting polymer electrolyte comprising a proton conducting ionomer cross-linked with an amount of a copolymer additive comprising cross-linking functional groups and other functional groups shows improved durability over the ionomer alone and provides for more stable inclusion of these other functional groups. The gas turbine rotor includes a compressor rotor shaft, a turbine rotor shaft and a coupling device frictionally connecting the two rotor shafts, wherein the coupling device is designed in such a way that the friction connection also exists when the two rotor shafts are displaced relative to one another. The optimally configured cluster features equal pilot density per OFDM symbol, two or more pilot sub-carriers per cluster, and interlaced pilot sub-carriers, which enables the base stations to successfully boost the pilot sub-carriers, for optimum performance. The locking slice connects an end of the pressing plate and has a locking hole. Optical studies of the products show a strong dependence on the nature of the stabilizing thiol ligands. Preferably, a neural network is trained using the determination.