Untitled Essay, Research Paper

Cryogenicss and the Future Cryogenics 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 intending “ Icy Cold, ” 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 measuring called the Kelvin ( K ) . The Kelvin graduated table for

Cryogenicss 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 Superfluidity. Cryogenicss first came approximately in 1877, when a Swiss Physicist named Rasul

Pictet and a Gallic Engineer named Louis P. Cailletet liquefied O for the first clip.

Cailletet created liquid O in his lab utilizing a procedure known as adiabatic enlargement,

which 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 ” ( Vance 26 ) .

At the same clip Pictet used the “ Joule-Thompson Effect, ” 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 ” ( McClintock 4 ) . After

Cailletet and Pictet, a 3rd method, known as cascading, was developed by Karol S.

Olszewski and Zygmut von Wroblewski in Poland. At this point in history Oxygen was now

able to be liquefied at 90 K, so shortly after liquid Nitrogen was obtained at 77 K, and

because of these promotions scientist all over the universe began viing in a race to

lower the temperature of affair to Absolute Zero ( 0 K ) [ Vance, 1-10 ] . 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 at 20 K

H is besides boiling, and 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, which 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 they

would hold to hold better keeping containers. So, scientists came up with insularity

techniques that we still use today. These techniques include expanded foam stuffs and

radiation screening. [ McClintock 43-55 ] 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 physicists head

they want to interrupt the Thermodynamic jurisprudence and make a temperature of absolute zero where

every proton, negatron, and neutron in an atom is perfectly frozen. Besides, their are two topics that are besides closely related to

cryogenies called Superconductivity and Superfluidity. 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 “ & # 8230 ; a province of

nothing opposition, & # 8230 ; ” ( Tilley 11 ) . This unusual behaviour was besides discovered by Heike

Kamerlingh Onnes. It 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. However, about all elements and compounds have Tc & # 8217 ; s between 1 K and 15 K ( or -457.68

( F and -432.67 ( F ) so they would non be really utile to us on a twenty-four hours to twenty-four hours footing [ McClintock

208-226 ] . Then in 1986, J Gregore Bednorz and K. Alex Muller discovered that an

oxide of La, 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, in 1987, scientists at the University of

Houston and the University of Alabama discovered YBCO, a compound with a Tc of 95 K. This

find made superconductivity possible above the boiling point of liquid Nitrogen,

so

now the 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 compund made of Thallium, Barium, Calcium, Copper, and Oxygen. Now, with the

handiness of high-temperature superconductors, all the scientific disciplines including, cryogenies

hold made extraordinary progresss. Some applications are demonstrated by magnetically

levitated trains, energy storage, motors, and Zero-Loss Transmission Lines. Besides,

superconducting electromagnets are used in Particle Accelerators, Fusion Energy Plants,

and Magnetic Resonance Imaging devices ( MRI & # 8217 ; s ) in Hospitals. Furthermore high-speed

cryogenic computing machine memories and communicating devices are in assorted phases of research.

This field has grown vastly since 1986 as you can see and will likely maintain turning. The 2nd topic related to cryogenies is Superfluidity.

Superfluidity is a unusual province of affair that is most common in liquid Helium, when it

is below a temperature of 2.17 K. Superfluidity means that the liquid “ & # 8230 ; discloses

no viscousness when going through a capillary or narrow slit & # 8230 ; ” ( Landau 195 ) and

besides flows “ & # 8230 ; through the slit unwraping no clash & # 8230 ; ” ( Landau 195 ) That this

agencies is that when Helium reaches this province it can flux, without any clash, through

the smallest holes and in between atoms in a compund. If the top is off the beaker it is

besides possible for the liquid Helium to flux up the side of the baker and out of the beaker

until all the liquid He is gone. It was so 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

Superfluidity is much more complex, and is non wholly understood by today & # 8217 ; s

physicists. [ McClintock 103-107 ] Cryogenics besides consists of many smaller scientific disciplines, including

Cryobiology, which is “ the survey of the effects of low-temperatures on stuffs of

biological beginning. “ ( Vance 528 ) 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.

Another field is Cryopumping. Cryopumping is the procedure “ of distilling gas or vapour

on a low-temperature surface. “ ( Vance 339 ) This is done by pull outing gas from a

vacuity vas by conventional methods so stop deading the staying gas on low temperature

spirals. This procedure has been utile when seeking to imitate the belongingss that the vacuity

in outerspace will hold on electronic circuitry. Cryogenics has besides been a portion of many modern progresss including:

The transit of energy in the signifier of a liquified gas.

Processing, handling, and supplying nutrient by cryogenic agencies has become a big concern,

supplying both frozen and lyophilized nutrient.

Liquid Oxygen powers projectiles and propulsion systems for infinite research.

Liquid Hydrogen is used in high-energy natural philosophies experiments.

Using cryogenic drill spots so boring for oil and other gases is easier.

Chemical synthesis and contact action.

Better fire contending fluids.

Gas separation.

Metal Fabrication. As you can see by now 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. However, its full potency will likely non be understood for rather a piece.

Though, as you can see, if we can hold on the constructs of cryogenies we will hold a tool

that will let us to make things runing from doing better bore spots to researching the

existence. The hereafter of cryogenies can best be summed up by Krafft A. Ehricke, a projectile

developer, when he said, “ It & # 8217 ; s centeral end is the saving of

civilisation. “ ReferencesKhalatnikov, I. M. , An Introduction to the Theory of Superfluidity ( New York: W.A.

Benjamin Inc. , 1965 ) .

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

Tilley, David R. and Tilley, John, Superfluidity and Superconductivity ( New York: John

Wiley and Sons, 1974 )

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