A proton conductive polymer comprising a repeating unit represented by formula :wherein R1, R2 and R3 each independently represents a substituent; and V, W and X each independently represents a positive integer. The antenna is characterized in that it is designed to operate without ground element, in particular without ground plane. While the rotary member rotates, a skid layer provides safety features between the rotary member and a subject-facing scan window. A method for treating fabric is provided. A third correction is undertaken wherein the value of a picture element of a structurally uniform image region in an image in the first image dataset, corrected according to the second correction, or an average of picture elements in this image region in the first image dataset, is subtracted from the respective values of all picture elements in this region in the first and second image datasets. A circuit arrangement configured to control a first NMOS switch is described.