The cryogenics , (from the Greek κρύος kryos, cold , and γενεια geneia generation) is the set of techniques used to cool a material to the boiling point of the nitrogen even lower or temperatures.
The boiling temperature of nitrogen, that is to say 77.36 K (or what is the same -195.79 ° C) is reached by immersing a sample in liquid nitrogen . The use of liquid helium instead of nitrogen allows it to reach its boiling temperature, which is 4.22 K (-268.93 ° C).
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- 1 Bio-cryopreservation
- 2 Applications
- 1 Other uses
- 3 Internal Links
- 4 Sources
The practice of bio-cryopreservation allows a body to be preserved by freezing it in order to resuscitate it in the future. It should be carried out immediately after a person has been pronounced dead to avoid rapidly occurring brain injuries within five to ten minutes after death.
The objective is to suspend the life of a person threatened by an incurable disease , until the cure is achieved. Or suspend vital functions until science manages to find the source of eternal youth or a notable increase in longevity .
Cryogenics is currently one of the tools for the future that is being considered as a therapeutic arsenal for new diseases called old age and death. It happens that now a group of scientists and wealthy and influential people have proposed that old age and death not be treated as they are known until now but as two diseases or the same disease at different stages. Some have even proposed that after clinical death, the person “continues to live at the tissue level” and that therefore, if he acts properly, he can recover from this state.
They argue that before the appearance of cardioversion on the scene, those who suffered cardiac arrest that could not be reversed with the usual resuscitation maneuvers, were declared definitively dead. After this, with the use of cardioversion, many saved their lives. These scientists point out that those who are not saved by cardioversion could, for example, be frozen until nanotechnology is developed enough to be able to ‘repair’ their body and bring it back to life.
Cryogenics is widely used in technologies that depend on superconductivity, since all known superconductors are only at low temperatures (the highest critical superconducting temperature recorded to date, at ambient pressure, is around 135 K (-138 , 15 ° C), but are generally much lower). For example, nuclear magnetic resonance devices used in medicine rely on cryogenic techniques to maintain the temperature of the superconducting magnets they house.
By using more advanced techniques it is possible to reach temperatures even closer to absolute zero (on the order of a thousandth of a kelvin): dilution coolers and adiabatic demagnetization. Such techniques have their main application in the field of research, since at sufficiently low temperatures the effects of quantum mechanics are noticeable in macroscopic bodies.
Cryogenic fluids such as nitrogen or carbon dioxide , which replace cold air to achieve the freezing effect, are also used in food freezing