Dynamics of transformation of ultrasonic vibrations in twisted waveguides Sergey B. Kudryshev, Valentin S. Minakov, Alexey A. Zakaluyzhnyy and Vladimir A. Peglivanyan MATEC Web Conf., 226 (2018) 04019 Published online: 07 November 2018 DOI: 10.1051/matecconf/201822604019