Eight International Conference New Trends in the Applications of Differential Equations in Sciences (NTADES 2021) 6-9 September 2021, Sts. Constantine and Helena (Bulgaria) The Eight International Conference on New Trends of Differential Equations in Sciences is organized in cooperation with Society of Industrial and Applied Mathematics. The conference will be devoted to the 75th Anniversary of Academician Petar Popivanov. The conference consists of invited and contributed papers. Several special sessions, as well as young researchers' sessions will be organized during the conference. The conference will be held in the Frederic Joliot-Curie International House of Scientists, St. Constantine and Helena, Bulgaria, 6-9 September 2021. The proceedings will be published in American Institute of Physics. For more information please visit the conference site: http://ntades.eu/2021/ntades/index.html