Process for producing a copper-containing aqueous solution, in which a copper mass is dissolved in the presence of an oxidant in an aqueous leach liquor containing monoethanolamine and 2CO3. In a first preferred embodiment, a single silicon oxide layer is placed between the silicon layer and the sapphire layer. The bipolar transistor also comprises a conformal layer situated on a first and a second side of the sacrificial post, where the conformal layer is not separated from the first and second sides of the sacrificial post by spacers. A corresponding flange of the roof outer panel is welded to the parts of the inner panel exposed by the notches of the outer panel. In accordance with the invention the wind turbine comprises a first cooling system for cooling the part of the outer surface of the generator stator andor of the outer wall of the nacelle located in the upper room. The antenna device includes a base plate of a conductive material, at least one slit disposed in at least one area of the base plate and having a form in which a portion of a closed curve is open, and a feeding part configured to supply current to an inner area surrounded by the slit.