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Ultracentrifuges
An ultracentrifuge is a centrifuge optimized for spinning a rotor at very high speeds, capable of generating acceleration as high as (approx. ). There are two kinds of ultracentrifuges, the preparative and the analytical ultracentrifuge. Both classes of instruments find important uses in molecular biology, biochemistry, and polymer science.Susan R. Mikkelsen & Eduardo Cortón. Bioanalytical Chemistry, Ch. 13. Centrifugation Methods. John Wiley & Sons, Mar 4, 2004, pp. 247-267. History In 1924 Theodor Svedberg built a centrifuge capable of generating 7,000 g (at 12,000 rpm), and called it the ultracentrifuge, to juxtapose it with the Ultramicroscope that had been developed previously. In 1925-1926 Svedberg constructed a new ultracentrifuge that permitted fields up to 100,000 g (42,000 rpm). Modern ultracentrifuges are typically classified as allowing greater than 100,000 g. Svedberg won the Nobel Prize in Chemistry in 1926 for his research on colloids and proteins using the ultrace ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centrifuge
A centrifuge is a device that uses centrifugal force to subject a specimen to a specified constant force - for example, to separate various components of a fluid. This is achieved by spinning the fluid at high speed within a container, thereby separating fluids of different densities (e.g. cream from milk) or liquids from solids. It works by causing denser substances and particles to move outward in the radial direction. At the same time, objects that are less dense are displaced and moved to the centre. In a laboratory centrifuge that uses sample tubes, the radial acceleration causes denser particles to settle to the bottom of the tube, while low-density substances rise to the top. A centrifuge can be a very effective filter that separates contaminants from the main body of fluid. Industrial scale centrifuges are commonly used in manufacturing and waste processing to sediment suspended solids, or to separate immiscible liquids. An example is the cream separator found in da ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Analytical Ultracentrifuge
An ultracentrifuge is a centrifuge optimized for spinning a rotor at very high speeds, capable of generating acceleration as high as (approx. ). There are two kinds of ultracentrifuges, the preparative and the analytical ultracentrifuge. Both classes of instruments find important uses in molecular biology, biochemistry, and polymer science.Susan R. Mikkelsen & Eduardo Cortón. Bioanalytical Chemistry, Ch. 13. Centrifugation Methods. John Wiley & Sons, Mar 4, 2004, pp. 247-267. History In 1924 Theodor Svedberg built a centrifuge capable of generating 7,000 g (at 12,000 rpm), and called it the ultracentrifuge, to juxtapose it with the Ultramicroscope that had been developed previously. In 1925-1926 Svedberg constructed a new ultracentrifuge that permitted fields up to 100,000 g (42,000 rpm). Modern ultracentrifuges are typically classified as allowing greater than 100,000 g. Svedberg won the Nobel Prize in Chemistry in 1926 for his research on colloids and proteins using the ultra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Émile Henriot (chemist)
Émile Henriot (2 July 1885–1 February 1961) was a French chemist notable for being the first to show definitively that potassium and rubidium are naturally radioactive. He investigated methods to generate extremely high angular velocities, and found that suitably placed air-jets can be used to spin tops at very high speeds—this technique was later used to construct ultracentrifuges. He was a pioneer in the study of the electron microscope. He also studied birefringence and molecular vibrations. He obtained his DSc in physics in 1912 the Sorbonne, Paris, under Marie Curie Maria Salomea Skłodowska-Curie (; ; 7 November 1867 – 4 July 1934), known simply as Marie Curie ( ; ), was a Polish and naturalised-French physicist and chemist who conducted pioneering research on radioactivity. She was List of female .... As a professor at the Free University of Brussels he attended the Solvay Conferences of 1924, 1927, 1930, 1933, 1948, 1951 and 1954. For many of the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jesse Beams
Jesse Wakefield Beams (December 25, 1898 in Belle Plaine, Kansas – July 23, 1977) was an American physicist at the University of Virginia. He was particularly known for his role in the development of the ultracentrifuge. Biography Beams completed his undergraduate B.A. in physics at Fairmount College in 1921 and his master's degree the next year at the University of Wisconsin. He spent most of his academic career at the University of Virginia, where he received his Ph.D. in physics in 1925. He spent the next three years in a physics fellowship at Yale University, where he performed research on the photoelectric effect with Ernest Lawrence. Beams was appointed a professor of physics at the University of Virginia in 1929 and was chair of the department from 1948 to 1962. During World War II, he worked on the Manhattan Project, where his ultracentrifuge was used to demonstrate the separation of the lighter uranium isotope U-235 from other isotopes. Officials in charge of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Revolutions Per Minute
Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or r⋅min−1) is a unit of rotational speed (or rotational frequency) for rotating machines. One revolution per minute is equivalent to hertz. Standards ISO 80000-3:2019 defines a physical quantity called ''rotation'' (or ''number of revolutions''), dimensionless, whose instantaneous rate of change is called ''rotational frequency'' (or ''rate of rotation''), with units of reciprocal seconds (s−1). A related but distinct quantity for describing rotation is ''angular frequency'' (or ''angular speed'', the magnitude of angular velocity), for which the SI unit is the radian per second (rad/s). Although they have the same dimensions (reciprocal time) and base unit (s−1), the hertz (Hz) and radians per second (rad/s) are special names used to express two different but proportional ISQ quantities: frequency and angular frequency, respectively. The conversions between a frequency and an angular frequency ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beckman Instruments
Beckman Coulter, Inc. is a Danaher Corporation company that develops, manufactures, and markets products relevant to biomedical testing. It operates in the industries of diagnostics under the brand name Beckman Coulter and life sciences under the brand name Beckman Coulter Life Sciences. The company was established in 1935 as National Technical Laboratories, and has become an international company through growth and acquisitions of other life sciences organizations. The company employs over 12,000 people, with $5.8 billion in annual sales by 2017. It is currently headquartered in Brea, California. Beckman Coulter was acquired by Danaher Corporation in 2011. History The company was founded by Caltech professor Arnold O. Beckman in 1935 as National Technical Laboratories to commercialize a pH meter that he had invented. In the 1940s, Beckman changed the name to Arnold O. Beckman, Inc. to sell oxygen analyzers, the ''Helipot'' precision potentiometer, and spectrophotometers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beckman Coulter
Beckman Coulter, Inc. is a Danaher Corporation company that develops, manufactures, and markets products relevant to biomedical testing. It operates in the industries of diagnostics under the brand name Beckman Coulter and life sciences under the brand name Beckman Coulter Life Sciences. The company was established in 1935 as National Technical Laboratories, and has become an international company through growth and acquisitions of other life sciences organizations. The company employs over 12,000 people, with $5.8 billion in annual sales by 2017. It is currently headquartered in Brea, California. Beckman Coulter was acquired by Danaher Corporation in 2011. History The company was founded by Caltech professor Arnold O. Beckman in 1935 as National Technical Laboratories to commercialize a pH meter that he had invented. In the 1940s, Beckman changed the name to Arnold O. Beckman, Inc. to sell oxygen analyzers, the ''Helipot'' precision potentiometer, and spectrophotometers. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitochondrion
A mitochondrion () is an organelle found in the cell (biology), cells of most eukaryotes, such as animals, plants and fungi. Mitochondria have a double lipid bilayer, membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is used throughout the cell as a source of chemical energy. They were discovered by Albert von Kölliker in 1857 in the voluntary muscles of insects. The term ''mitochondrion'', meaning a thread-like granule, was coined by Carl Benda in 1898. The mitochondrion is popularly nicknamed the "powerhouse of the cell", a phrase popularized by Philip Siekevitz in a 1957 ''Scientific American'' article of the same name. Some cells in some multicellular organisms lack mitochondria (for example, mature mammalian red blood cells). The multicellular animal ''Henneguya zschokkei, Henneguya salminicola'' is known to have retained mitochondrion-related organelles despite a complete loss of their mitochondrial genome. A large number ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beckman Model E Hm50tr96s
Beckman may refer to: * Beckman (surname) *Arnold Orville Beckman, chemist and entrepreneur *Beckman Coulter, a biomedical laboratory instruments company founded by Arnold O. Beckman * Beckman Coulter Life Sciences, a life sciences company focused on research instruments and reagents for enabling new discoveries * 3737 Beckman, an asteroid * Institutes and research centers supported by the Arnold and Mabel Beckman Foundation ** Beckman Center for Molecular and Genetic Medicine at Stanford University, Stanford, California ** Beckman Institute at Caltech, California Institute of Technology, Pasadena, California *** Beckman Institute Laser Resource Center (BILRC) at Caltech ** Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign ** Beckman Laser Institute, University of California, Irvine, in Irvine, California ** Beckman Research Institute (BRI) at the City of Hope National Medical Center in Duarte, California, United States * Schools ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ribosome
Ribosomes () are molecular machine, macromolecular machines, found within all cell (biology), cells, that perform Translation (biology), biological protein synthesis (messenger RNA translation). Ribosomes link amino acids together in the order specified by the codons of messenger RNA molecules to form polypeptide chains. Ribosomes consist of two major components: the small and large ribosomal subunits. Each subunit consists of one or more ribosomal RNA molecules and many ribosomal proteins (). The ribosomes and associated molecules are also known as the ''translational apparatus''. Overview The sequence of DNA that encodes the sequence of the amino acids in a protein is transcribed into a messenger RNA (mRNA) chain. Ribosomes bind to the messenger RNA molecules and use the RNA's sequence of nucleotides to determine the sequence of amino acids needed to generate a protein. Amino acids are selected and carried to the ribosome by transfer RNA (tRNA) molecules, which enter the riboso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
