RETRACTED: Transition processes during the start-up of the pumping unit of happ Z.E. Abdulkhaev, M.M. Madraximov, J.T. Orzimatov and A.M. Abdurazaqov E3S Web Conf., 420 (2023) 07023 Published online: 04 September 2023 DOI: 10.1051/e3sconf/202342007023