This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/policies/article-withdrawal). This article has been retracted at the request of the Editors-in-Chief. A journal-wide investigation by Elsevier's Research Integrity & Publishing Ethics team identified violations of the journal's policies on conflict of interest related to the submission and review of this paper. Review of this submission was handled by Guest Editor Elena-Niculina Dragoi despite an extensive recent record of collaboration, including co-publication, with two of the paper co-authors (Ceren Karaman, Nevin Erk). In addition, there was a significant increase of citations of papers authored by the Guest Editor and by author Karaman between the original submission and the revised version
6 papers by Dragoi and 8 by Karaman were added in the revised version of the paper. This compromised the editorial process and breached the journal's policies. The authors disagree with this retraction and dispute the grounds for it.