Publication in CSF is embarrassing, but not definitive proof of crackpottery. What kind of papers do Mansourans publish in other journals? Here's one by three authors at the Mansoura University math department.
Spelling a famous physicist's name wrong in the abstract is a red flag, but citing Nottale, El Naschie and Ord is a dead giveaway.
The Mansoura University math department has rudimentary pages for A.M. Shahin and E. Ahmed, the contact author. There is no page for Yassmin A. Omar, who may be a graduate student. There's more information about E. Ahmed at SUNY Buffalo's Mathematicians of the African Diaspora (MAD) site: Elsayed Mohamed Elsayed Ahmed. (MAD celebrates E. Ahmed as a black mathematician, but I doubt he's black. Having been born in 1954 in Mansoura it would be unusual.)
I checked to see whether International Journal of Nonlinear Science (IJNS) has M.S. El Naschie or Ji-Huan He on its editorial board. It doesn't.