1Avicenna(c. 980 – 1037)• Persian polymath; the foremost physician and philosopher of his time. He was also an astronomer, chemist, geologist, logician, paleontologist, mathematician, physicist, poet, psychologist, soldier, statesman, and teacher.• He invented the refrigeration coil, which condenses aromatic vapors. • This was a breakthrough in distillation technology and he made use of it in his steam distillation process to separate temperature sensitive material and produce essential oils.Development of the Kelvin Absolute Temperature Scale• William Thomson (later Lord Kelvin) was interested in Charles’s Law which states that when a gas is cooled by one degree Celsius, it’s volume drops by 1/273– This would lead to zero volume at -273°C– How can matter exist without taking up space?• Thomson instead suggested that it was the energy of motion that decreased with temperature– At -273°C, the molecules cease motion and essentially not take up space– He called -273°C absolute zero because no further temperature reduction is possible. This later became known as 0 Kelvin.Sources: University of Glasgow and World of Scientific DiscoveryLord KelvinLiquefaction of OxygenLiquid oxygen is the liquid form of element oxygen. In nowadays it is widely usedin many fields.Liquefaction of substance that normally exists as gas dates back to the 18th century.The first successful attempt was made by a French mathematician Gaspard Monge,who liquefied sulfur dioxide in 1784. In the following decades, people succeededin liquefy many gases, but none of them was able to liquefy oxygen gas. In thelate 1840s, Irish physical chemist Thomas Andrews suggested that every gas has aprecise temperature, which is the critical temperature. Above the temperature gascannot be liquefied even under great pressure. Following Andrews idea, scientistcame up with the idea of using ’cascade’ process to get low temperature. In thismethod, one liquefied gas is used to cool another gas with lower critical temperature,and so on. By using the cascade process, French physicist Louis Paul Cailletetliquefied three gases, oxygen, nitrogen and carbon monoxide.Now liquid oxygen is playing a significant role in both industry and research.Compare with oxygen gas, liquid oxygen is much easier to store and transport.Liquid oxygen is stored in hospitals for patients with breathing problems. It isalso used as oxidizer in industry, such as producing ion and many other metals.Furthermore, liquid oxygen is used as oxidizer in spacecraft such as rockets. Withoutliquefaction of oxygen, one cannot provide enough oxygen with such limitedspace and cannot put rocket into use.Liquefaction of oxygen is an important event in the history. It was one of the humanfirst attempts to liqeify ’permanent gas’. Liquid oxygen also serves as animportant substance today.Dewar, Sir James(1842 – 1923)• Scottish chemist and physicist; best known for his work with low-temperature phenomena.• He studied the specific heat of hydrogen and was the first person to produce hydrogen in liquid form (1898) and to solidify it (1899).• He constructed a machine for producing liquid oxygen in large quantities in 1891 and subsequently invented the Dewar flask or thermos in 1892.• The Dewar flask is a container for storing hot or cold substances. It consists of two flasks (usually glass), one inside the other, separated by a vacuum that reduces the transfer of heat, preventing a temperature change.Sir James Dewar(1842–1923) Invented Vacuum flask in 1892Why vacuum? L ~ size2James DewarInvented a silvered, double walled, glass vacuum vessel to contain cryogenic liquids for the first time, for relatively long periods, before they evaporated.Most widely known in connection with his work on the liquefaction of the so-called permanent gases and his researches at temperatures approaching absolute zero.His work was used to help create vapor-cooled radiation shields and multilayer insulationsReceived Hodgkins Gold Medal for his work on liquid oxygen and liquid hydrogen1842-1923Important events in the history of civilization, related to cryogenics(1908) Heike Kamerlingh Onnes liquefies helium Commonly used cryogenic refrigerant in physics experiments and applications It has very interesting properties like superfluidity Led to the discovery of superconductivity  It cools down lossless superconducting magnets used in modern technological applicationsThe Discovery of Superconductivity-Discovered 1911-Won Onnes Nobel in 1913-First superconducting Materials:1. Mercury (Gold deemed too hard to refine) (4.2K)2. Lead (7 K)3. Niobium Nitride (16 K)-Made possible by liquefaction of Helium and Dewar containers-Used to prove Tesla’s Patent of low temperature resonating circuitHeinke Kamerlingh OnnesHeike Kamerlingh OnnesSuperconductivity was discovered in 1911.• H. K. Onnes was studying the resistance of mercury using the recently-discovered liquid helium as a refrigerant. • when mercury was cooled down to 4.2 K, he observed that the resistance abruptly disappeared. • Superconductors show a property of perfect diamagnetism, which is called the Meissner Effect.Meissner effect: levitation of a magnet above a superconductorUnlike a normal state, magnetic flux can’t penetrate a superconducting state.3Discovery of Superconductivity• Heike Kamerlingh Onnes• Made possible by the recent discovery of liquid helium as a refrigerant• First discovered super conductive material: Mercury1933: Temperature of .25K Reached•Several groups were able to cool past .3K with magnetic cooling.•The technique uses adiabatic demagnetization. First suggested by Debye (1926) and Giauque (1927).•The process is in use today both in industry, where it has been adapted to work at room temperature, and in research, where substances can be cooled to micro Kelvin. http://en.wikipedia.org/wiki/Magnetic_refrigerationI’m not lazy but I only do any work on dipoles! Magnetic RefrigerationW. F. Giauque and D. P. MacDougall, 1933Temperature change in material caused by changing magnetic field via the magneto-caloric effect. Giauque used alloys of gadolinium.1949 Nobel Prize in ChemistryMagnetic Cooling• Independently theorized by Debye in 1926 and Giauque in 1927• Adibatic demagnetization first demonstrated by Giauque in 1933 • Allowed for temperatures below 1K to be reached for the first timeWilliam Frances GiauquePeter DebyeBy Ishmal