Engineering and Applied Science Letters (EASL) (2617-9709 Online, 2617-9695 Print) is an international and fully open-access journal from the publishers of Ptolemy Research Press. We publish scientifically valid primary research from all areas of the Engineering and Applied Sciences. We publish one volume containing four issues in March, June, September and December each year. The accepted papers will be published online immediately in the currently running issue.
In this paper, we study completete monotonicity properties of certain functions associated with the polygamma functions. Subsequently, we deduce some inequalities involving difference of polygamma functions.
A carbon nanotube (CNT) is a miniature cylindrical carbon structure that has hexagonal graphite molecules attached at the edges. In this paper, we compute the numerical invariant (Topological indices) of linear [n]-phenylenic, lattice of \(C_{4}C_{6}C_{8}[m, n]\), \(TUC_{4}C_{6}C_{8}[m, n]\) nanotube, \(C_{4}C_{6}C_{8}[m, n]\) nanotori.