Book excerpt: Papers on kn-digital sequence and Smarandache function, generalized separation axioms, the bounds of the largest eigen value and the Laplacian energy of certain class of graphs, several identities involving the classical Catalan numbers, more about functional Alexandroff topological spaces, clopen sets in uniform topology on BE-algebras, and similar topics. Contributors: S. Balasubramanian, V. Lokesha, Ranjini P. S, D. Senthilkumar and K. Thirugnanasambandam, N. Murugesan, P. Suguna, M. Mohamadhasani, and others.