How 'cool' is cryogenics!!!!

The term cryogenics is derived from the Greek word "Kyros" which means cold. That means cryogenics is the science that deals with the production, effects, and application of a wide variety of materials at very low temperatures. It creates the impression of a science-fiction, but it is a modern science applied in various fields like aerospace engineering, medicine, food science, human biology, and electronics. The working temperature in cryogenics ranges from -150oC to -273oC. In the science community, -273oC is termed as absolute zero temperature, where the movement of molecules stops and they acquire the lowest energy state.



At these extreme conditions, properties of materials such as strength, thermal conductivity, ductility, and electrical resistance are altered for commercial applications. Experimentation in the field of cryogenics will create a broad understanding of the material behavior and help in developing new technologies.

History of Cryogenics

Swiss Physicist Rasul Pictet and French Engineer Louis P. Cailletet worked independently and converted oxygen into a liquid state in 1877. Pictet liquefied oxygen by Joule -Thompson while Cailletet used adiabatic expansion for the same process. In cryogenics, liquefied gases are used to freeze other materials at -150 0C (123 K). Both scientists were able to liquefy oxygen at 90 K. After this breakthrough, many scientists were able to liquefy Helium (4.2 K), Hydrogen (20 K), and Nitrogen (70 K).

Liquids having temperatures below 3 K are primarily used for laboratory work, particularly research into the properties of helium. At 2.19 K, a liquid with such low viscosity can flow through microscopic holes. This property is known as superfluidity.

Food preservation and transportation of gases

A large quantity of food items produced is transported great distances and requires preservation. Liquid nitrogen is sprayed on food items to make them fresh for a longer period. It vaporizes quickly absorbs heat from food and is packed in sealed packets.

One of the most common applications of the cryogenic liquefication technique is the storage and transportation of natural gases. A Mixture of gases like methane, ethane, butane, etc. are compressed and liquefied at 110 K, contracted to 1/600th of its volume, and transported in specialized cylindrical tanks.

Cryogenics in Aerospace Engineering

Infrared, gamma-ray, and x-ray detectors are used in space to carry out experiments. They tend to operate at cryogenic temperatures. By cooling these detectors to these low temperatures, astronomers can increase their sensitivity and performance. This technique is also used to preserve samples retrieved from space and experiments carried out at the International space station. 


                                                             
 

Finally, liquid hydrogen, liquid oxygen, etc. are commonly used as rocket fuels. NASA's Space Shuttle used cryogenic hydrogen/oxygen propellant to get itself into orbit. Liquid-fueled rockets have higher specific thrust than solid rockets and are capable of being throttled, shut down, and restarted. The Propellant is carefully insulated from all sources of heat to prevent it from boiling off and to stop it from expanding and exploding the propellant tank.

 

Life 2.0: Cheating death

Everybody wants to go to heaven but nobody is in a hurry to reach there. People will say heaven can wait. They wanted to live a little more life on earth before moving onto something else. Considering this thought, Robert Ettinger started the Cryonics Institute in 1976. 


Source: Cryogenics Institute

Cryonics is the technique of stor­ing human bodies at extremely low temperatures using liquid Nitrogen/ Helium. This technology provides hope that one day the patient will be reanimated in the future. This concept has attracted thousands of people around the world, but controversial that the body is collected immediately after the patient is declared legally dead and kept in a cryogenic tank. The body is preserved with the hope that there will be a time when new technology will bring a dead body back to life. In Cryonics 70-75 % of water present in our body is taken out and replaced with cryoprotectants. This chemical prevents ice formation in tissues at 153 K called vitrification. This allows body parts to be preserved for a long time without freezing. At present over 150 patients are vitrified in cryostasis. 

At present, for about $28,000 to $150,000, your body can be stored at a cryonic facility. 


7 Comments

  1. I came to know about cryogenics for the first time from ur blog.... It's worthy to read such information...keep sharing man

    ReplyDelete
  2. I came to know about cryogenics for the first time from ur blog.... It's worthy to read such information...keep sharing man

    ReplyDelete
Post a Comment
Previous Post Next Post