By employing the gaseous oxygen as oxidizer and gaseous hydrogen as fuel, hot-firing tests were performed for aerospike nozzle and dual-bell nozzle test engines with altitude compensating features.

The content of impurities in water - is greater than that in gas - atomization.

Alif table line-bubble aerator not only offers an high oxygenation efficiency but also can be lifted out of water surface for replacement without disturbing the operation of the aeration tank.