The only practical way to accelerate something in free space is by reaction. The idea is the same as in air breathing propulsion (to push something backwards) but in rockets the “something” must be inside and is lost. Here is a revealing derivation of the thrust equation for vacuum:

Systems Considerations (Valving, tanks, etc) Characteristics of some monopropellants (Reprinted from H. Koelle, Handbook of Astronautical Engineering, McGraw-Hill, 1961.) Flame Chemical Density temp

Electrothermal Augmentation Concept Geostationary satellites are most of the time exposed to the sun, but they still are subject to eclipse periods around the two vernal points (March 21, September 21);

Ionization and Conduction in a High-pressure Plasma A normal gas at T <3000K is a good electrical insulator, because there are almost no ∼ free electrons in it. For pressure

These notes aim at providing order-of-magnitude results and at illuminating the mechanisms involved. Numerical precision will be sacrificed in the interest of physical clarity. We look first at the arc in a cooled constrictor, with no flow, expand the analysis

Prof. Manuel Martinez-Sanchez Page 2 of 11Bohm velocity: Why?

Colloidal thrusters are electrostatic accelerators of charged liquid droplets. They were first proposed and then intensively studied from around 1960 to 1975 as an alternative to normal ion engines. Their appeal at that time rested with the large “molecular mass” of the droplets, which was known to increase the thrust density of an ion engine

For a given mass flow m ind thrust F, we would like to minimize the running power

中国佛学的发展到了清末，由于诸多原因， 已显示下坡趋势；其时，虽有祩宏等四大高僧 出来振臂一呼，但其衰落气象依然。然而，此 时西方却悄然兴起一股佛学热。于是，在近现 代的中国知识界与佛教界一些人士重新检讨以 往的历史，力图振兴佛学研究。这当中，有佛 教组织内部的高僧，也有社会上的知名思想家。 尽管他们的目标或意图不同，但其诸多努力却 在客观上推进了近代中国佛学的复兴

一、 分“三步走”基本实现现代化 二、 实现“三步走”目标的战略思想 三、 推进经济增长方式的根本转变 四、 调整和优化国民经济结构 五、 贯彻科教兴国战略 六、 实施可持续发展战略