਀吀栀攀 一漀戀攀氀 倀爀椀稀攀 椀渀 䌀栀攀洀椀猀琀爀礀  ㄀㤀㐀㤀 㰀⼀栀㈀㸀

਀圀䤀䰀䰀䤀䄀䴀 䘀刀䄀一䌀䤀匀 䜀䤀䄀唀儀唀䔀 ਀ 㰀椀洀最 愀氀椀最渀㴀爀椀最栀琀 戀漀爀搀攀爀㴀㈀ 猀爀挀㴀∀㄀⸀最椀昀∀㸀 ਀㰀瀀㸀 William F. Giauque is best known for his research in two areas, thermodynamic studies at very low temperatures and the isotopic composition of oxygen. In order to carry out the first of these investigations, Giauque found it necessary to develop a new technique of cooling gases to temperatures close to absolute zero, a method known as adiabatic demagnetization . By using this system, Giauque was able to obtain temperatures within a few thousandths of a degree from absolute zero. For his research, Giauque was awarded the 1949 Nobel Prize in chemistry. His findings led to improvements in the production of gasoline, steel, rubber, and glass. His discovery of the previously unknown oxygen isotopes 17 and 18 resulted in the recalibration of atomic weight scales.਀㰀⼀瀀㸀㰀瀀㸀 William Francis Giauque was born in Niagara Falls, Ontario, Canada, on May 12, 1895. His mother, Isabella Jane (Duncan) Giauque, and his father, William Tecumseh Sherman Giauque, were United States citizens. When Giauque was young, his family moved back to the United States where his father took a job with the Michigan Central Railroad as a station master. When the elder Giauque died in 1908, his family returned to Canada, where William enrolled in the Niagara Falls Collegiate and Vocational School.਀㰀⼀瀀㸀㰀瀀㸀 At first, it seemed that Giauque would have to assume the responsibility of supporting his family. After completing his two-year course at the vocational school, he found a job at the Hooker Electro-Chemical Company in Niagara Falls, New York. But his mother was determined to convince him to pursue a college education, and her employer, chemist J. W. Beckman , influenced his decision to enroll at the University of California at Berkeley in 1916. Giauque subsequently received his bachelor of science in chemistry in 1920 and then entered graduate school at Berkeley. There he was exposed to some of the nation's greatest chemists, including Gilbert Newton Lewis, George E. Gibson (his thesis advisor), Joel Hildebrand, and G. E. K. Branch. Giauque's dissertation concerned the properties and behavior of materials at very low temperatures, a subject which remained the focus of his academic career.਀㰀⼀瀀㸀㰀瀀㸀 The focus of Giauque's earliest research was the Third Law of Thermodynamics, first proposed by German physical chemist Walther Nernst in 1906. Nernst hypothesized that the entropy (the measure of randomness in a closed system) of a pure crystalline substance at absolute zero is zero. In order to test this hypothesis, it was necessary to find ways of cooling materials to temperatures as close to absolute zero as possible.਀㰀⼀瀀㸀㰀瀀㸀 The "father" of low-temperature research of this kind had been the Dutch physicist Heike Kamerlingh-Onnes. During the first decade of the twentieth century, Kamerlingh-Onnes had developed methods for cooling gases by causing them to evaporate under reduced pressure. Using this method, he had obtained temperatures of about one degree kelvin (1 K). While other researchers had produced even lower temperatures to within a few tenths of a degree kelvin over the next two decades, Kamerlingh-Onnes' method seemed to reach its limit by the early 1920s.਀㰀⼀瀀㸀㰀瀀㸀 In 1924 Giauque suggested a new technique for producing cooling; Peter Debye proposed the same procedure independently at about the same time. In this method, a weakly magnetic material is magnetized in such a way that all of its molecules line up in exactly the same direction. This material is then surrounded with liquid helium and demagnetized. During demagnetization, the material's molecules go from a highly ordered to a highly disordered state. The energy needed to bring about this change is removed from the liquid helium, causing its temperature to fall even further.਀㰀⼀瀀㸀㰀瀀㸀 This method was beset with a number of practical problems, including the difficulty of measuring the very low temperatures produced. Giauque devoted nearly twenty years to refining the technique and obtaining results with it. Finally, in 1938, he was able to report having reduced the temperature of a sample of liquid helium to 0.004 K, by far the lowest temperature yet observed.਀㰀⼀瀀㸀㰀瀀㸀 During the 1920s, Giauque was also working on the study of entropy in gases. As part of this work, he regularly examined the band spectra produced by such gases. In 1928, while working on this problem, Giauque made an unexpected find. He observed that the spectrum of normal atmospheric oxygen consists of one set of strong lines and two sets of very weak, barely visible lines. The conclusion he drew was that normal oxygen must consist of three isotopes, one (oxygen-16) that is abundant and two (oxygen-17 and oxygen-18) that are relatively rare.਀㰀⼀瀀㸀㰀瀀㸀 Giauque's professional reputation continued to grow at Berkeley and throughout the world. He was promoted to assistant professor in 1927, associate professor in 1930, and full professor in 1934. At his retirement in 1962, he was named emeritus professor of chemistry. In addition to his 1949 Nobel Prize in chemistry, he was also recognized by a number of other awards, including the Chandler Foundation Medal in 1936, the Elliot Cresson Medal in 1937, and the American Chemical Society's Gibbs and Lewis Medals in 1951 and 1955, respectively.਀㰀⼀瀀㸀㰀瀀㸀 Giauque was married to the former Muriel Frances Ashley, a physicist, on July 19, 1932. They had two sons, William Francis Ashley and Robert David Ashley. Giauque died at his home in Berkeley on March 28, 1982 as a result of a fall਀㰀⼀瀀㸀㰀瀀㸀 ਀ ਀ ਀ ਀ ਀ William Francis Giauque was born in Niagara Falls, Canada, of U.S. parentage, on May 12, 1895, the first of three children of William Tecumseh Sherman Giauque and Isabella Jane Duncan.਀㰀⼀瀀㸀㰀瀀㸀 He attended public grammar schools principally in Michigan. Following the death of his father, in 1908, the family returned to Niagara Falls, Canada, where he received his secondary school education in the Niagara Falls Collegiate Institute. After graduation he sought employment in various power plants at Niagara Falls for financial reasons and because he had planned for many years to become an electrical engineer and wanted preliminary experience. He was unable to obtain this type of work. At this point chance entered decisively in the form of a newspaper advertisement of the Hooker Electro-Chemical Company in Niagara Falls, New York, which led him to accept employment in their laboratory. The well-organized operations in this chemical plant, together with problems which he saw in course of solution, captured his interest and caused him to decide to become a chemical engineer.਀㰀⼀瀀㸀㰀瀀㸀 After two years employment he entered the College of Chemistry of the University of California, where he received the B.S. degree with highest honors in 1920, was a University Fellow for the year 1920-1921 and James M. Goewey Fellow 1921-1922. He received the Ph.D. degree in chemistry with a minor in physics in 1922.਀㰀⼀瀀㸀㰀瀀㸀 Although his undergraduate work at the university was selected with the idea of an engineering career, he soon acquired a liking for fundamental research. The emphasis on scientific investigation by the group of faculty and students associated with Professor Gilbert N. Lewis was the major influence.਀㰀⼀瀀㸀㰀瀀㸀 He was appointed Instructor of Chemistry in 1922 and after passing through the intermediate grades of professorship he became Professor of Chemistry in 1934.਀㰀⼀瀀㸀㰀瀀㸀 His interest in the third law of thermodynamics as a field of research was aroused by the experimental work for his Ph.D. research under Professor G.E. Gibson. This work, which was concerned with the relative entropies of glycerine crystals and glass, had its origin in discussions of Professors Lewis and Gibson.਀㰀⼀瀀㸀㰀瀀㸀 The principal objective of his researches has been to demonstrate through a considerable number and variety of accurate tests that the third law of thermodynamics is a basic natural law.਀㰀⼀瀀㸀㰀瀀㸀 The researches of his students and himself have included a large number of accurate entropy determinations from low temperature measurements, particularly on condensed gases. The entropies and other thermodynamic properties of many gases have also been determined from quantum statistics and molecular energy levels available from band spectra and other sources.਀㰀⼀瀀㸀㰀瀀㸀 Correlated investigations of the entropy of oxygen from its incompletely interpreted band spectrum and from low-temperature heat capacity measurements with Dr. H.L. Johnston, led to the discovery of oxygen isotopes 17 and 18 in the Earth's atmosphere and the fact that chemists and physicists were unknowingly using different atomic weight scales.਀㰀⼀瀀㸀㰀瀀㸀 Investigation of the effect of magnetic fields on the entropies of paramagnetic substances led to the invention of the adiabatic demagnetization method of producing temperatures considerably below 1° absolute. This method was first demonstrated in collaboration with Dr. D.P. MacDougall.਀㰀⼀瀀㸀㰀瀀㸀 Professor Giauque's scientific work has been described in some 75 papers.਀㰀⼀瀀㸀㰀瀀㸀 He has received the Chandler Medal and the honorary degree of Sc.D. from Columbia University, an honorary LL.D. from the University of California, and the Elliott Cresson Medal from the Franklin Institute. In 1951 he received the Willard Gibbs Medal and in 1956 the Gilbert Newton Lewis Medal. He was Faculty Research Lecturer of the University of California in 1948. He is a member of the National Academy of Sciences, the American Philosophical Society, the American Chemical Society, Institut International du Froid, and is Fellow of the American Physical Society and of the American Academy of Arts and Sciences.਀㰀⼀瀀㸀㰀瀀㸀 In 1932 he married Dr. Muriel Frances Ashley. They have two sons, William Francis Ashley G. and Robert David Ashley G.਀㰀⼀瀀㸀㰀瀀㸀 ਀ ਀ ਀ ਀ ਀ ਀ ਀ ਀ ਀ ਀ ਀