[1] PSGR Krishnammal Coll Women, Dept Chem, Coimbatore 641004, Tamilnadu, India
[2] KPR Inst Engn & Technol, Dept Phys, Coimbatore 641407, Tamilnadu, India
[3] Sri Krishna Coll Engn & Technol, Dept Phys, Coimbatore 641008, Tamilnadu, India
[4] KPR Inst Engn & Technol, Dept English, Coimbatore 641407, Tamilnadu, India
[5] Sri Ramakrishna Mission Vidyalaya Coll Arts & Sci, Dept Chem, Coimbatore 641020, Tamil Nadu, India
[6] Builders Engn Coll, Dept Phys, Kangeyam 638108, Tamilnadu, India
[7] Dr NGP Inst Technol, Dept Chem, Coimbatore 641048, Tamilnadu, India