Cryogenics And The Future Essay Research Paper

Cryogenicss And The Future Essay, Research Paper

Cryogenicss is a survey that is of great importance to the human race and has been a major undertaking for applied scientists for the last 100 old ages. Cryogenics, which is derived from the Grecian word kryos significance & # 8220 ; Icy Cold, & # 8221 ; is the survey of affair at low temperatures. However low is non even the right word for the temperatures involved in cryogenies, seeing as the highest temperature dealt with in cryogenies is 100 ( C ( -148 ( F ) and the lowest temperature used, is the unachievable temperature -273.15 ( C ( -459.67 ( F ) . Besides, when speech production of cryogenies, the footings Celsius and Fahrenheit are seldom used. Alternatively scientists use a different temperature measuring graduated table called the Kelvin ( K ) . The Kelvin graduated table for Cryogenics goes from 173 K to a fraction of a Kelvin above absolute nothing. There are besides two chief scientific disciplines used in cryogenies, and they are Superconductivity and Superfluity.

Cryogenicss foremost came approximately in 1877, when Swiss Physicist Rasul Pictet and a Gallic Engineer named Louis P. Cailletet liquefied O for the first clip. Cailletet created the liquid O in his lab utilizing a procedure known as adiabatic enlargement. Adiabatic enlargement is a thermodynamic procedure in which the temperature of a gas is expanded

without adding or pull outing heat from the gas or the surrounding system ( 4 ) . At the same clip Pictet used the & # 8220 ; Joule-Thompson Effect & # 8221 ; , which is a thermodynamic procedure that states that the temperature of a fluid is reduced in a procedure affecting enlargement below a certain temperature and force per unit area ( 2 ) . After Cailletet and Pictet, a 3rd method, known as cascading, was developed by Karol S. Olszewski and Zygmut von Wroblewski both of Poland. At this point in history, O could now be liquefied at 90 K. Soon after this find liquid Nitrogen was obtained at 77 K, and because of these promotions scientists all over the universe began viing in a race to take down the temperature of affair to Absolute Zero, or 0 K ( 4 ) .

Then in 1898, James DeWar mad a major progress when he succeeded in liquefying H at 20 K. The ground this progress was so dramatic was that H is besides boiling at this temperature. This presented a really hard handling and storage job. DeWar solved this job by contriving a double-walled storage container known as the DeWar flask. This flask could incorporate and keep the liquid H for a few yearss. However, at this clip scientists realized that if they were traveling to do any more progresss in this field of cryogenies, they would hold to hold better keeping containers. Scientists so came up with insularity techniques that we still use today. These techniques include expanded foam stuffs and radiation shielding. ( 2 )

The last major progress in cryogenies eventually came in 1908 when the Dutch physicist Heike Kamerling Onnes liquefied Helium at 4.2 and so 3.2 K. The remainder of the progresss in cryogenies have been highly little since it is a cardinal Thermodynamic jurisprudence that you can near but ne’er really make absolute nothing. Since 1908 our engineering has greatly increased and we can now stop dead Na gas to within 40 millionths of a Kelvin above absolute nothing. However, in the dorsum of every physicist? s caput they want to interrupt the Thermodynamic Law and make a temperature of absolute nothing where every proton, negatron, and neutron in an atom is perfectly frozen.

Besides, there are two topics that are besides closely related to cryogenies called Superconductivity and Superfluity. Superconductivity is a low-temperature phenomenon where a metal loses all electrical opposition below a certain temperature, called the Critical Temperature ( Tc ) , and transportations to a province of nothing opposition. ( 3 ) Heike Kamerlingh Onnes besides discovered this unusual behaviour. This Critical Temperature was discovered when Onnes and one of his alumnus pupils realized that Mercury loses all of its electrical opposition when it reaches a temperature of 4.15 K. ( 2 )

Then in 1986, J. Gregore Bednorz and K. Alex Muller discovered that an oxide of lanthan

um, Ba, and Cu becomes superconductive at 30 K. This find shocked the universe and stirred scientists to happen even more “High-Temperature Superconductors” . After this find in1987, scientists at the University of Houston and the University of Alabama worked together and discovered YBCO. YBCO is a compound with a Tc of 95 K. This find made superconductivity possible above the boiling point of liquid Nitrogen. This meant that the now comparatively inexpensive, liquid N could replace the high priced liquid He required for cryogenic experiments. To day of the month the highest reported Tc is 125 K, which belongs to a compound made of Thallium, Barium, Calcium, Copper, and Oxygen. Now, with the handiness of high-temperature superconductors, all the scientific disciplines, including cryogenies, have made extraordinary progresss. Magnetically levitated trains, energy storage, motors, and Zero-Loss Transmission Lines show some applications. Besides, superconducting electromagnets are used in Particle Accelerators, Fusion Energy Plants, and Magnetic Resonance Imaging devices ( MRI’s ) in Hospitals. Furthermore high-velocity cryogenic computing machine memories and communicating devices are in assorted phases of research. This field has grown vastly since 1986, and has continued to progress.

The 2nd topic related to cryogenies is Superfluity. Superfluity is a unusual province of affair that is most common in liquid Helium, when it is below a temperature of 2.17 K. Superfluity means that the liquid discloses no viscousness when going through a capillary or narrow slit, and besides flows through the slit unwraping no clash. ( 1 ) That this means is that when Helium reaches this province it has the ability to flux without any clash through the smallest holes, and in between atoms in a compound. If the top is off a beaker it is besides possible for the liquid Helium to flux up the side and out of the beaker until all the liquid He is gone. It was discovered that when any liquid attacks about.2 K it has about the exact same belongingss of superconducting metals, every bit far as specific heat, magnetic belongingss, and thermic conduction. Even though both Superconducting and Superfluidic stuffs have similar belongingss, the phenomenon of Superfluity is much more complex, and is non yet wholly understood by today & # 8217 ; s physicists. ( 2 )

Cryogenicss besides consists of many smaller scientific disciplines including Cryobiology. Cryobiology is the survey of the effects of low-temperatures on stuffs of biological beginning. ( 4 ) Developments in this field have led to modern methods of continuing blood, seeds, tissue, and variety meats below the temperature that was obtained by the usage of liquid N. Besides, Cryobiology has led to the development of the cryogenic scalpel, which can dampen or destruct tissue with a high grade of truth, doing it possible to coagulate cuts every bit shortly as you cut them. So in theory, you could one twenty-four hours hold surgery without holding to cover with any blood.

As you can see cryogenies is still a really immature scientific discipline, but in the last 10 old ages it has catapulted to being the anchor of about every other signifier of scientific discipline. Although unluckily its full potency will likely non be understood for rather some clip. Once we can hold on the constructs of cryogenies we will hold a tool that will let us to make things runing from doing better surgical tools to researching the existence. The hereafter of cryogenies can best be summed up by Krafft A. Ehricke, a projectile developer, when he said, & # 8220 ; Its centeral end is the saving of civilization. & # 8221 ;

Cryogenicss and the Future

Angie Bertugli

Bibliography

Mentions

1. Khalatnikov, I. M. , An Introduction to the Theory of Superfluidity ( New York: W.A. Benjamin Inc. , 1965 ) .

2. McClintock, Michael, Cryogenics ( New York: Reinhold Publishing Corp. , 1964 ) .

3. Tilley, David R. and Tilley, John, Superfluity and Superconductivity ( New York: John Wiley and Sons, 1974 ) .

4. Vance, Robert W. , Cryogenic Technology ( London: John Wiley & A ; Sons, Inc. , 1963 ) .