[1] Process Dynamics and Control Group,
[2] Chemical Engineering Division,undefined
[3] Indian Institute of Chemical Technology,undefined
[4] Hyderabad 500 007,undefined
[5] India e-mail: kyrani@iict.ap.nic.in,undefined
[6] Department of Chemical Engineering,undefined
[7] Indian Institute of Technology,undefined
[8] Madras 600 036,undefined
[9] India e-mail: vsrr@acer.iitm.ernet.in,undefined