Propeller blades without reverse rotating force and speed acceleration propeller blades are equipped in all kinds of transportations for accelerating speed without extra energy and generating transportation electricity. One outer part and two inner parts and are locked mutually by help of a circumferential locking element having resilient abilities and which is arranged at the intersectional point between the three parts, and. A method for forming a metal-insulator transition switching device includes depositing a layer of bulk metal-insulator transition material in between a first electrode and a second electrode to form a channel region and forming a gate electrode operatively connected to the channel region. It also relates to a process for the production of this recording material. Strong jets of water are also sprayed upwards on the surface of the tube, hitting the lower side of the board when it tilts and thus also pushing the board with the surfer upwards. At least a metal layer is formed to have a standing-wave structure to distribute a clock signal to receiver end points from a clock source such that the receiver end points are substantially electrically equivalent with respect to the clock source.