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Michael Faraday (1791-1867)
Michael Faraday (; 22 September 1791 – 25 August 1867) was an English scientist who contributed to the study of electromagnetism and electrochemistry. His main discoveries include the principles underlying electromagnetic induction, diamagnetism and electrolysis. Although Faraday received little formal education, he was one of the most influential scientists in history. It was by his research on the magnetic field around a conductor carrying a direct current that Faraday established the concept of the electromagnetic field in physics. Faraday also established that magnetism could affect rays of light and that there was an underlying relationship between the two phenomena.. the 1911 Encyclopædia Britannica. He similarly discovered the principles of electromagnetic induction, diamagnetism, and the laws of electrolysis. His inventions of electromagnetic rotary devices formed the foundation of electric motor technology, and it was largely due to his efforts th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Faraday Constant
In physical chemistry, the Faraday constant, denoted by the symbol and sometimes stylized as ℱ, is the electric charge per mole of elementary charges. It is named after the English scientist Michael Faraday. Since the 2019 redefinition of SI base units, which took effect on 20 May 2019, the Faraday constant has the exactly defined value given by the product of the elementary charge ''e'' and Avogadro constant ''N''A: : : :. Derivation The Faraday constant can be thought of as the conversion factor between the mole (used in chemistry) and the coulomb (used in physics and in practical electrical measurements), and is therefore of particular use in electrochemistry. Because 1 mole contains exactly entities, and 1 coulomb contains exactly elementary charges, the Faraday constant is given by the quotient of these two quantities: :. One common use of the Faraday constant is in electrolysis calculations. One can divide the amount of charge (the current integrated over t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Newington Butts
Newington Butts is a former hamlet, now an area of the London Borough of Southwark, that gives its name to a segment of the A3 road running south-west from the Elephant and Castle junction. The road continues as Kennington Park Road leading to Kennington; a fork right is Kennington Lane, leading to Vauxhall Bridge. Michael Faraday was born in Newington Butts. It is believed to take its name from an archery butts, or practice field. The area gave its name to an Elizabethan theatre which saw the earliest recorded performances of some Shakespearean plays. Toponymy The Middle English word "butt" referred to an abutting strip of land, and is often associated with medieval field systems. The 1955 ''Survey of London'' published by London County Council could find no historical reference to archery butts in Newington although the connection is mentioned elsewhere (e.g., in 1792). The name may have alternatively derived from the triangle of land between the roads, as the word "butts" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Faraday Wave
Faraday waves, also known as Faraday ripples, named after Michael Faraday (1791–1867), are nonlinear standing waves that appear on liquids enclosed by a vibrating receptacle. When the vibration frequency exceeds a critical value, the flat hydrostatic surface becomes unstable. This is known as the Faraday instability. Faraday first described them in an appendix to an article in the ''Philosophical Transactions'' of the Royal Society of London in 1831. If a layer of liquid is placed on top of a vertically oscillating piston, a pattern of standing waves appears which oscillates at half the driving frequency, given certain criteria of instability. This relates to the problem of parametric resonance. The waves can take the form of stripes, close-packed hexagons, or even squares or quasiperiodic patterns. Faraday waves are commonly observed as fine stripes on the surface of wine in a wine glass that is ringing like a bell. Faraday waves also explain the 'fountain' phenomenon on a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Clerk Maxwell
James Clerk Maxwell (13 June 1831 – 5 November 1879) was a Scottish mathematician and scientist responsible for the classical theory of electromagnetic radiation, which was the first theory to describe electricity, magnetism and light as different manifestations of the same phenomenon. Maxwell's equations for electromagnetism have been called the " second great unification in physics" where the first one had been realised by Isaac Newton. With the publication of "A Dynamical Theory of the Electromagnetic Field" in 1865, Maxwell demonstrated that electric and magnetic fields travel through space as waves moving at the speed of light. He proposed that light is an undulation in the same medium that is the cause of electric and magnetic phenomena. (This article accompanied an 8 December 1864 presentation by Maxwell to the Royal Society. His statement that "light and magnetism are affections of the same substance" is at page 499.) The unification of light and elec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Thomas Brande
William Thomas Brande FRS FRSE (11 January 178811 February 1866) was an English chemist. Biography Brande was born in Arlington Street, London, England, the youngest son of six children to Augustus Everard Brande an apothecary, originally from Hanover in Germany. He was educated first in Kensington and then in Westminster. After leaving Westminster School, he was apprenticed, in 1802, to his brother, an apothecary, with the view of adopting the profession of medicine. He studied medicine at Great Windmill Street Medical School and at St George's Hospital, before being drawn to chemistry following a meeting with Humphry Davy. He then began to lecture in chemistry, based on a sound knowledge of which he acquired in his spare time. In 1811 he published the first of what were to be two very influential articles on the measurement of alcohol in fermented drinks, including wine, cider and ale. Until that point chemists had only been able to measure alcohol in distilled drinks ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Humphry Davy
Sir Humphry Davy, 1st Baronet, (17 December 177829 May 1829) was a British chemist and inventor who invented the Davy lamp and a very early form of arc lamp. He is also remembered for isolating, by using electricity, several elements for the first time: potassium and sodium in 1807 and calcium, strontium, barium, magnesium and boron the following year, as well as for discovering the elemental nature of chlorine and iodine. Davy also studied the forces involved in these separations, inventing the new field of electrochemistry. Davy is also credited to have been the first to discover clathrate hydrates in his lab. In 1799 he experimented with nitrous oxide and was astonished at how it made him laugh, so he nicknamed it "laughing gas" and wrote about its potential anaesthetic properties in relieving pain during surgery. Davy was a baronet, President of the Royal Society (PRS), Member of the Royal Irish Academy (MRIA), Fellow of the Geological Society (FGS), and a mem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Balloon
A balloon is a flexible bag that can be inflated with a gas, such as helium, hydrogen, nitrous oxide, oxygen, and air. For special tasks, balloons can be filled with smoke, liquid water, granular media (e.g. sand, flour or rice), or light sources. Modern day balloons are made from materials such as rubber, latex, polychloroprene, or a nylon fabric, and can come in many different colors. Some early balloons were made of dried animal bladders, such as the pig bladder. Some balloons are used for decorative purposes or entertaining purposes, while others are used for practical purposes such as meteorology, medical treatment, military defense, or transportation. A balloon's properties, including its low density and low cost, have led to a wide range of applications. The rubber balloon was invented by Michael Faraday in 1824, during experiments with various gases. He invented them for use in the lab. Applications Play Decoration Balloons are used for decorating bir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Regelation
Regelation is the phenomenon of ice melting under pressure and refreezing when the pressure is reduced. This can be demonstrated by looping a fine wire around a block of ice, with a heavy weight attached to it. The pressure exerted on the ice slowly melts it locally, permitting the wire to pass through the entire block. The wire's track will refill as soon as pressure is relieved, so the ice block will remain intact even after wire passes completely through.'' This experiment is possible for ice at −10 °C or cooler, and while essentially valid, the details of the process by which the wire passes through the ice are complex. The phenomenon works best with high thermal conductivity materials such as copper, since latent heat of fusion from the top side needs to be transferred to the lower side to supply latent heat of melting. In short, the phenomenon in which ice converts to liquid due to applied pressure and then re-converts to ice once the pressure is removed is called ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Premelting
Premelting (also surface melting) refers to a quasi-liquid film that can occur on the surface of a solid even below melting point (T_m). The thickness of the film is temperature (T) dependent. This effect is common for all crystalline materials. Premelting shows its effects in frost heave, the growth of snowflakes and, taking grain boundary interfaces into account, maybe even in the movement of glaciers. Considering a solid-vapour interface, complete and incomplete premelting can be distinguished. During a temperature rise from below to above T_m , in the case of complete premelting, the solid melts homogeneously from the outside to the inside; in the case of incomplete premelting, the liquid film stays very thin during the beginning of the melting process, but droplets start to form on the interface. In either case, the solid always melts from the outside inwards, never from the inside. History The first to mention premelting might have been Michael Faraday in 1842 for ice surf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MHD Converter
__NOTOC__ A magnetohydrodynamic converter (MHD converter) is an electromagnetic machine with no moving parts involving magnetohydrodynamics, the study of the kinetics of electrically conductive fluids (liquid or ionized gas) in the presence of electromagnetic fields. Such converters act on the fluid using the Lorentz force to operate in two possible ways: either as an electric generator called an MHD generator, extracting energy from a fluid in motion; or as an electric motor called an MHD accelerator or magnetohydrodynamic drive, putting a fluid in motion by injecting energy. MHD converters are indeed reversible, like many electromagnetic devices. Michael Faraday first attempted to test a MHD converter in 1832. MHD converters involving plasmas were highly studied in the 1960s and 1970s, with many government funding and dedicated international conferences. One major conceptual application was the use of MHD converters on the hot exhaust gas in a coal fired power plant, where it c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Separation
Magnetic separation is the process of separating components of mixtures by using a magnet to attract magnetic substances. The process that is used for magnetic separation separates non-magnetic substances from those which are magnetic. This technique is useful for the select few minerals which are ferromagnetic (iron-, nickel-, and cobalt-containing minerals) and paramagnetic. Most metals, including gold, silver and aluminum, are nonmagnetic. A large diversity of mechanical means are used to separate magnetic materials. During magnetic separation, magnets are situated inside two separator drums which bear liquids. Due to the magnets, magnetic particles are being drifted by the movement of the drums. This can create a magnetic concentrate (e.g. an ore concentrate). History Michael Faraday discovered that when a substance is put in a magnetic environment, the intensity of the environment is modified by it. With this information, he discovered that different materials can be separ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lines Of Force
A line of force in Faraday's extended sense is synonymous with Maxwell's line of induction. According to J.J. Thomson, Faraday usually discusses ''lines of force'' as chains of polarized particles in a dielectric, yet sometimes Faraday discusses them as having an existence all their own as in stretching across a vacuum.Notes on Recent Researches in Electricity and Magnetism Joseph John Thomson, James Clerk Maxwell, 1883 In addition to lines of force, J.J. Thomson—similar to Maxwell—also calls them tubes of |
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