The science and technology of deep refrigeration processing occurring
at temperatures lower than about 150 k. is the field of cryogenics. The
name cryogenics is evolved from Greek word ‘kryos’ meaning icy cold.
Phenomena that occurs at cryogenic temperatures include liquefaction
and solidification of ambient gases; loss of ductility and
embrittlement of some structural materials such as carbon steel;
increase in thermal conductivity to a maximum value, followed by
further decrease in temperature. Cryogenics is the low temperature (150
K) refrigeration. It explains the properties of cryogens used and their
principles. Storage methods and handling techniques are covered.
Cryogenics are applied in different fields of production,
transportation, medicine, aerospace, physics research etc. Rocket
propulsion is imparting force to a flying vehicle such as missile or
spacecraft. Different types of rockets and their parts are explained.
Cryogenics has future applications in many fields like
superconductivity and propulsion fields. Cryogenics is being applied to
variety of research areas; a few of which are: food processing and
refrigeration, space craft life supporting system, space simulation,
microbiology, medicine, surgery, electronics, data processing and metal
working.
Rocket propulsion is the process of imparting a force to flying vehicle
such as a missile, by momentum of ejected matter. The matter, called
propellant, is stored in the vehicle and ejected at high velocity. In
chemical rocket, the propellants are chemical compounds that undergo a
chemical combustion reaction releasing the energy for thermodynamically
accelerating and ejecting the gaseous reaction products at high
velocities. Chemical rocket propulsion is thus differential from other
types of rocket propulsion which use nuclear, solar or electrical
energy as their power source and which may use mechanism other than
adiabatic expansion of a gas for achieving high ejection velocities.
