| || Effect of Ultrasonic Vibrations in Some Heat Treatments
Author : Suryanaryana, K. ;Sreekumar, K.;Vasudevan, R.
Source : Defence Science Journal ; Vol:31(3) ; 1981 ; pp 199-210
Subject : 669 Metallurgy
Keywords : Increased ductility ;Shorter process time;Spheroidisation;Porous compacts;Hardening of solid
Abstract : The effect of ultrasonic vibrations on many heat treatment processes, primarily ageing, and other such as, hardening of solid and porous compacts, spheroidisation, etc. are described. Results obtained with regard to ageing are particularly promising and indicate the possibility of obtaining a distinctly shorter process time as also an increased ductility at the same strength. These features may be of interest to the aircraft industry.
| || Launch stabilisation system for vertical launch of a missile
Author : Sreekumar, K. ;Ramchandani, A. T.
Source : Defence Science Journal ; Vol:55(3) ; 2005 ; pp 223-230
Subject : 629.762 Missiles
Keywords : Launch stabilisation system;Launch platform;SVLS;Missile launching;Control system;Controller design
Abstract : "The launch platform stabilisation control system is a roll-pitch stabilised platform for the vertical launch of a missile from a naval ship. Stabilisation of the launch platform is achieved with the help of embedded controllers and electro-hydraulic servo control system. The launch platform is stabilised wrt true horizontal with a 2-axis (roll and pitch) stabilisation system consisting of a gimbal and a set of three high-pressure servo hydraulic actuators. The control system uses rate gyro and tilt sensor feedbacks for stabilising the platform. This paper outlines the details of the launch platform stabilisation control system, results of digital simulation, and the performance during sea trials. "