RETRACTED: Transition processes during the start-up of the pumping unit of happZ.E. Abdulkhaev, M.M. Madraximov, J.T. Orzimatov and A.M. AbdurazaqovE3S Web Conf., 420 (2023) 07023DOI: https://doi.org/10.1051/e3sconf/202342007023