ترجمه مقاله نقش ضروری ارتباطات 6G با چشم انداز صنعت 4.0
- مبلغ: ۸۶,۰۰۰ تومان
ترجمه مقاله پایداری توسعه شهری، تعدیل ساختار صنعتی و کارایی کاربری زمین
- مبلغ: ۹۱,۰۰۰ تومان
Composite propellants mostly consist of two major ingredients: oxidiser and binder. It has almost been established now that propellants undergo slow decomposition during the course of ageing [1-3]. To increase the longevity of the propellants, it is necessary to know the mechanism of the ageing process. Thus it has to be established whether the rate-controlling step lies in the oxidiser decomposition or in the binder decomposition. The objective of the present investigation, therefore, is to identify the constituent responsible for the ageing. It may be noted that contrary to the available literature on the mechanism of the ageing of double-base propellants, very little is known about the mechanism of composite propellant ageing [4-11]. From accelerated ageing studies in the temperature range 40-750C of five cast composite propellants, Kuletz and Pakulak [4] have shown that the primary component altered at the exposed surface is the binder, whereas in the interior it is the oxidiser. However, they found the activation energy (E) for surface, subsurface, and bulk material to be almost similar (23-27 kcal/mole).