**Conflict of interest**

The authors declare that there is no conflict of interests regarding the publication of this chapter.

## **Author details**

#### Jagannathan Thirumalai

Address all correspondence to: thirumalaijg@gmail.com; thirumalaijg@hotmail.com

Department of Physics, School of Electrical and Electronics Engineering, Srinivasa Ramanujan Centre, SASTRA University, Kumbakonam, Tamil Nadu, India
