Khaled Zennir is an Associate professor at the Department of Mathematics, College of Sciences and Arts, Qassim University, Ar-Rass, Saudi Arabia. He obtained his B.Sc. in Mathematics from University 20 Août 1955, Skikda in 2006, and his M.Sc. in Mathematics from University Badji Mokhtar, Annaba, in 2009. He received his PhD in Mathematics in 2013 from Sidi Bel Abbès University, Algeria (Assist. professor). He obtained his highest diploma in Algeria (Habilitation, Mathematics) from Constantine University, Algeria in May 2015 (Assoc. professor). He served as Lecturer at the University 20 Août 1955- Skikda (2007–2008), as Assistant Professor at the University of Science and Technology Mohamed Boudiaf (2009–2012), as Associate Professor at the University 20 Août 1955- Skikda (2012–2015), as Assistant Professor at the Qassim University (2015–2021), and has been Associate Professor at the Qassim University since 2015. His research work is aimed at treating different issues and investigating several types of systems in the field of evolution partial differential equations, including the existence of solutions and asymptotic analysis for systems of damped PDEs (Nonlinear Hyperbolic Partial Differential Equations: Global Existence, Blow-Up, and Long Time Behavior, Control of PDEs). A major part of his research activities has been dedicated to establishing general stability results and explicit energy decay rates for different evolution problems in viscoelasticity.