M N Rao is presently Professor-in -charge, Technical Teachers' Training Institute, Extension Centre Banglore. He received his BE(hons) degree in civil Engineering from Andra University in 196 and MSc(Engg) degree in Public Health Engineering from Madras University 1961. He obtained his Ph D(Engg)from Burdwan University in 1969 and was sponsered as a Commonwealth scholar to the University of Auckland New Zealand, for two years for post-doctrol work. He taught at Regional Engineering College, Durgapur for 16 years and Later also worked as Manager(R&D) in environmental engineering with Suri and Nayar Limited, Banglore. Dr Rao is an active member of many Professional bodies and societies. He is associated with the board of studies of nine universities. He is an Expert member in many committees includind the technical advisory Committee of Karnatka state Pollution Control Board, Banglore. H V N Rao is presently Reader in civil Engineering at R V College of Engineering Banglore. He received his degree from Mysore University and BE (civil) and ME (Environmental) degrees from Banglore University. He has a teaching experience of 2 years. He is an active member of many professonal bodies and societies like the Institution of Engineers(India), Institution of public Health Engineers, Indian Association for Environmental Management, Indian Association for Air Pollution Control, and Indian Society for Technical Education . He has published many papers on variousaspects of environmental engineering.