Weighted Semigroup Algebras as Dual Banach algebras
  In this paper, among other things, we study those conditions under which the weighted semigroup algebra $\ell^1(S,\omega)$ is a dual Banach algebra with respect to predual $c_0(S)$. Some useful examples, illustrating the results, are also included. 
M. Abolghasemi, A. Rejali, and H. R. E. Vishki