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Svedberg (Svedberg), Theodore

( Swedish chemist, Nobel Prize in Chemistry, 1926)

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Biography Svedberg (Svedberg), Theodore
August 30, 1884, Mr.. - 25 February 1971
Swedish chemist Theodor Svedberg was born in the estate Flerang, not far from Mr.. Gavle. He was the only child of Elias Svedberg, an engineer and manager of the local iron foundry, and Augusta (Alstermark) Svedberg. The boy's father is often performed with him long outings, bringing up his interest in nature. It also allows young C. to experiment in a small laboratory ironworks.
Studying at Karolinska school in цvrebro, C. especially carried away by physics, chemistry and biology. Despite the fact that it is most interested in botany, he decided to become a chemist, because he believed that it would allow him deeper 'look' in the biological processes. In January 1904,. he entered the University of Uppsala, and in September 1905. received a bachelor's degree. In the same year published his first article. S. continued to work at Uppsala University, and in 1907. he was awarded a doctorate for a thesis on colloidal systems.
Colloidal systems are a mixture, in which the smallest particles of one substance are dispersed (scattered) in another substance. Colloidal particles are larger than those of conventional (real) solutions, but not so much that they can be viewed under a microscope, or that they are precipitated by gravity. Their sizes range from 5 nanometers (5 billionths of a meter) to about 200 nanometers. Examples of colloidal systems are the 'Indian Ink' (coal particles in water), smoke (solid particles in the air) and milk fat (tiny balls of fat in a water solution). In his doctoral dissertation with. described a new method of vibration of electric discharges between metal electrodes placed in a liquid, in order to obtain relatively pure colloidal solutions of metals. For the previously accepted method of using the DC was characterized by a high degree of contamination.
In 1912, Mr.. S. the first in the Uppsala University professor of physical chemistry and remained in that job for 36 years. Despite the fact that C. developed and other methods of obtaining colloidal solutions, it became best known for his studies of the physical properties of colloidal systems. A study of a thorough study of diffusion and Brownian motion of colloidal particles (random motion of tiny particles suspended in liquid) was further evidence of the benefit realized in 1908. Jean Perrin experimental confirmation of the theoretical work of Albert Einstein and Marian Smoluchowski, established the presence of molecules in solution. Perrin proved that the size of large colloidal particles may be established by measuring the rate of precipitation of. Most of the colloidal particles, however, is deposited in their environment so slowly that this method seemed impractical.
To determine the size of particles in colloidal solutions of C. applied designed by Richard Zsigmondy ultramicroscope. He managed to prove that colloidal solutions obey the classical physical and chemical laws for dilute solutions. Nevertheless, in most cases, this method made it impossible to establish the size of the smallest particles and the distribution of particle sizes.
With. believed that the deposition of colloidal particles would be accelerated in a strong gravitational field produced by high-speed centrifuge. During his stay in the University of Wisconsin in 1923, where he was for 8 months Visiting Professor, C. started to create an optical centrifuge, in which the deposition of particles would be recorded by photographing. As the particles move, not only settles, but under the influence of conventional currents, C. using this method was unable to determine the size of particles. He knew that the high heat conductivity of hydrogen could help eliminate temperature differences, and hence the convection currents. Designed wedge-shaped foreface cell and placing a rotating cell in an atmosphere of hydrogen, C. in 1924, back in Sweden, together with his colleague Herman Rind achieved deposition without convection.
A year later, with. found that the biological macromolecules (proteins) can also cause the precipitate from solution. He proved that all the molecules of this protein monodisperse (ie. have the same size) in contrast to the particles of metal colloidal systems, which are polydisperse, because their size are quite different. Moreover, the deposition rate and protein can also be concluded about the size of the molecule. This conclusion was the first indication that the molecules of proteins have an explicit mass and shape. As a result, made with. discoveries centrifuge has become a major tool for biochemical studies. Now the speed of the fallout in the sediment is measured in units named after S.
In 1926, Mr.. S. was awarded the Nobel Prize in Chemistry 'for his work in the field of disperse systems'. In his opening speech on behalf of the Royal Swedish Academy of Sciences X.G. Sederbaum said: 'The motion of particles suspended in a liquid ... demonstrated the real existence of molecules, and hence the atoms - a fact all the more remarkable that until recently an influential school of scientists declared these material particles figment of the imagination '. In his Nobel lecture, which he read in the next year. S., . by reviewing the technical and theoretical problems, . related to his work, . described the great potential value, . a, . his opinion, . will have ultracentrifuge for progress in many areas, . including medicine, . physics, . Chemistry and Industry.,
. In the new laboratory of physical chemistry, specially built for C
. Swedish Government, he spent 15 years perfecting the design of its centrifuge. In January 1926, Mr.. scientist tested a new model ultracentrifuge rotors with oil, which has 40 100 revolutions per minute. And 5 years later created a new model, where the number of revolutions per minute, reached 56 000. A long series of improvements in the design of the rotor has led to the fact that in 1936. centrifuge could commit 120000 rpm. At such a speed on the deposition system operated in the power of 525 000 F (where F - the force of gravity).
The next stage of research was the study of proteins, hemoglobin and gemotsianina. Including analysis and sedimentation characteristics of the 100 proteins involved in respiratory processes of many animals. It was proved that all protein molecules are circular in shape, monodispersed and have a high molecular weight. Expanded the scope of the study using an ultracentrifuge at the expense of other biological macromolecules, with. found that carbohydrates such as cellulose and starch to form long, thin, polydisperse molecules.
Throughout his life, C. also interested in the phenomenon of radioactivity. His joint work with Daniel Stremgolmom proved that some radioactive elements, previously seen as different, chemically indistinguishable from each other and occupy the same place in the periodic table. This discovery presaged the study of isotopes Frederick Soddy. In the late 20-ies. S. studied the action of alpha particles emitted by radioactive substances, in solutions of proteins. After opening in 1932. James Chadwick of the neutron - a particle with no electric charge, C. constructed a small neutron generator to study the effects of neutron irradiation and the production of radioactive isotopes as chemical and biological indicators.
In 1949, upon reaching retirement age,. retired. However, a special resolution, he was allowed to retain the post of director shortly before established at Uppsala University Institute of Nuclear Chemistry, Gustav Werner, . where it is mainly due to his efforts, was set synchrocyclotron.,
. S
. was a man living mind and diverse interests. Beautiful amateur photographer, he seriously studied the process of photographing. In the 20-ies. Using a different wavelength when photographing "Codex Argenteus", the Gothic Bible, 500 g. AD, he found that ultraviolet rays do see that poorly discernible structure, which it is written. S. deeply interested in botany and was the owner of one of the best botanical collections in Sweden. He was married four times: at Andrea Andreev (1909), Jane Frodo (1916), Ingrid Blomquist (1938) and Margaret HallцLn (1948). He had six sons and six daughters.
With. contributed greatly to strengthening the link between academic science and practical application of scientific achievements. Thus, during the Second World War, he has deployed in the Swedish production of synthetic rubber. Supporter of understanding of science as an international phenomenon, he was invited to work at Uppsala University for Foreign Scientists. Working at the intersection of science, C. made a significant contribution to the unification of physics, chemistry and biology. Scientist died Feb. 25, 1971, Mr.. in цvrebro (Sweden).
With. has been awarded many prizes. In and among Berzelius Medal of the Royal Swedish Academy of Sciences (1944), Medal of the Franklin Institute Franklinskogo (1949) and Medal of the Gustav Adolf Uppsala University (1964). He was an honorary doctorate by the University of Groningen, Wisconsin, Uppsala, Harvard, Oxford, Delaware, and Paris, as well as a member of more than 30 professional societies, including the Royal Swedish Academy of Sciences. Royal Society, U.S. National Academy of Sciences and Academy of Sciences.


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