A thin layer of liner is applied to ensure a good bond between the insulator and the propellant in case-bonded rocket motors. It also acts as a protective shield for the insulator by providing a limited fire protection effect. Liner compositions should preferably be based on the same binder system used in the propellant formulations. As the liner has to hold the propellant and the insulator without debond under all the environmental conditions, it plays a key role in predicted performance of a rocket motor. Hence, studies were carried out to improve the liner properties using various hydroxyl compounds, such as butanediol, cardanol, trimethylol propane, pyrogallol, etc as additives. Butanediol and phloroglucinol combination gave the best results in terms of mechanical properties and interface properties for the liner compositions. The effect of filler content on the liner properties was also studied. The results showed that higher filler content does not affect interface properties. Considering the fire retardancy effect and reinforcement of antimony trioxide (S£ 2 0 3 ), the formulation containing higher Sb 2 O 3 was selected. The studies on pot life/castable life of liner showed that propellant could be cast up to 6 days after liner coating, without adversely affecting the bonding and the bond strength.
The capacity of the transport system and the low cost and dependability of the transport services has enabled an increasing number of people to seek the economic, social and cultural opportunities that urban living ideally provides. But paradoxically, metropolitan cities have now grown to the point where they threaten to strangle the transportation that made them possible …… with the technical ability to solve its transport problem well in hand, the modern city is confronted by transportation problems more complex than ever before. Despite all the methods of movement, the problem in cities is how to move. (Owen 1987 )
Sriraman attempts to understand the impact of the governance structure in the Indian context on the provision of transport infrastructure and services. Government owned railways have taken some initiatives to promote freight movement in a big way by the establishment of dedicated corridors with a different model of investment and operation. Equally significant are the initiatives taken up by the different transport related Ministries to promote multi-modalism which involves a change in governance structure. The issue is whether there can be effective implementation of these policy initiatives given continuing poor practices and deviation from an ideal institutional governance framework. One other issue discussed critically relates to the effective implementation of planning and operating of information technology practices in the context of smart cities that are being encouraged in a background of poor urban physical infrastructure.
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