Centennial jubilee of Academician Rabotnov and contemporary handling of his fractional operator

This note is dedicated to the centennial jubilee of the Russian Academician Yury Rabotnov, who was a pioneer in the application of fractional operators in Mechanics of Solids. In the present Note, the authors wish to present a contemporary handling of Rabotnov operators introduced in 1948 and to show their connectedness with fractional derivatives, what provides the ageless interest to his ideas and results.