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Whewellite
Whewellite is a mineral, hydrated calcium oxalate, formula Ca C2 O4· H2O. Because of its organic content it is thought to have an indirect biological origin; this hypothesis is supported by its presence in coal and sedimentary nodules. However, it has also been found in hydrothermal deposits where a biological source appears improbable. For this reason, it may be classed as a true mineral. Whewellite, or at least crystalline calcium oxalate, does also arise from biological sources. Small crystals or flakes of it are sometimes found on the surfaces of some cacti, and kidney stones frequently have the same composition. Whewellite was named after William Whewell (1794–1866), an English polymath, naturalist and scientist, professor of moral philosophy at Cambridge and inventor of the system of crystallographic indexing. Heat decomposition Whewellite is used as a thermogravimetric analysis standard due to its well-known decomposition temperatures and products. See also * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whewellite Tga
Whewellite is a mineral, hydrated calcium oxalate, formula Ca C2 O4· H2O. Because of its organic content it is thought to have an indirect biological origin; this hypothesis is supported by its presence in coal and sedimentary nodules. However, it has also been found in hydrothermal deposits where a biological source appears improbable. For this reason, it may be classed as a true mineral. Whewellite, or at least crystalline calcium oxalate, does also arise from biological sources. Small crystals or flakes of it are sometimes found on the surfaces of some cacti, and kidney stones frequently have the same composition. Whewellite was named after William Whewell (1794–1866), an English polymath, naturalist and scientist, professor of moral philosophy at Cambridge and inventor of the system of crystallographic indexing. Heat decomposition Whewellite is used as a thermogravimetric analysis standard due to its well-known decomposition temperatures and products. See also * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Whewell
William Whewell ( ; 24 May 17946 March 1866) was an English polymath, scientist, Anglican priest, philosopher, theologian, and historian of science. He was Master of Trinity College, Cambridge. In his time as a student there, he achieved distinction in both poetry and mathematics. The breadth of Whewell's endeavours is his remarkable feature. In a time of increasing specialization, Whewell belonged in an earlier era when natural philosophers investigated widely. He published work in mechanics, physics, geology, astronomy, and economics, while also composing poetry, writing a Bridgewater Treatise, translating the works of Goethe, and writing sermons and theological tracts. In mathematics, Whewell introduced what is now called the Whewell equation, defining the shape of a curve without reference to an arbitrarily chosen coordinate system. He also organized thousands of volunteers internationally to study ocean tides, in what is now considered one of the first citizen scienc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium Oxalate
Calcium oxalate (in archaic terminology, oxalate of lime) is a calcium salt of oxalic acid with the chemical formula . It forms hydrates , where ''n'' varies from 1 to 3. Anhydrous and all hydrated forms are colorless or white. The monohydrate occurs naturally as the mineral whewellite, forming envelope-shaped crystals, known in plants as raphides. The two rarer hydrates are dihydrate , which occurs naturally as the mineral weddellite, and trihydrate , which occurs naturally as the mineral caoxite, are also recognized. Some foods have high quantities of calcium oxalates and can produce sores and numbing on ingestion and may even be fatal. Tribes with diets that depend highly on fruits and vegetables high in calcium oxalate, such as in Micronesia, reduce the level of it by boiling and cooking them. They are a constituent in 76% of human kidney stones. Calcium oxalate is also found in beerstone, a scale that forms on containers used in breweries. Occurrence Many plants accumu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxalate Minerals
Oxalate (IUPAC: ethanedioate) is an anion with the formula C2O42−. This dianion is colorless. It occurs naturally, including in some foods. It forms a variety of salts, for example sodium oxalate (Na2C2O4), and several esters such as dimethyl oxalate (C2O4(CH3)2). It is a conjugate base of oxalic acid. At neutral pH in aqueous solution, oxalic acid converts completely to oxalate. Relationship to oxalic acid The dissociation of protons from oxalic acid proceeds in a stepwise manner; as for other polyprotic acids, loss of a single proton results in the monovalent hydrogenoxalate anion . A salt with this anion is sometimes called an acid oxalate, monobasic oxalate, or hydrogen oxalate. The equilibrium constant ( ''K''a) for loss of the first proton is (p''K''a = 1.27). The loss of the second proton, which yields the oxalate ion, has an equilibrium constant of (p''K''a = 4.28). These values imply, in solutions with neutral pH, no oxalic acid and only trace am ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium Minerals
Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to its heavier homologues strontium and barium. It is the fifth most abundant element in Earth's crust, and the third most abundant metal, after iron and aluminium. The most common calcium compound on Earth is calcium carbonate, found in limestone and the fossilised remnants of early sea life; gypsum, anhydrite, fluorite, and apatite are also sources of calcium. The name derives from Latin ''calx'' "lime", which was obtained from heating limestone. Some calcium compounds were known to the ancients, though their chemistry was unknown until the seventeenth century. Pure calcium was isolated in 1808 via electrolysis of its oxide by Humphry Davy, who named the element. Calcium compounds are widely used in many industries: in foods and pharmace ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Minerals Named After People
This is a list of minerals named after people. The chemical composition follows name. A *Abelsonite: C31H32N4Ni – American physicist Philip Hauge Abelson (1913–2004)alfred *Abswurmbachite: Cu2+Mn3+6O8SiO4 – German mineralogist Irmgard Abs-Wurmbach * Adamite: Zn2AsO4OH – French mineralogist Gilbert Joseph Adam (1795–1881) *Agrellite: NaCa2Si4O10F – English optical mineralogist Stuart Olof Agrell (1913–1996) * Agricolaite: K4(UO2)(CO3)3 – German scholar Georgius Agricola (1494–1555) * Aheylite: Fe2+Al6 (PO4)2sub>2·4H2O – American geologist Allen V. Heyl (1918–2008) * Albrechtschraufite: Ca4Mg(UO2)2(CO3)6F2·17H2O – Albrecht Schrauf (1837–1897), professor of mineralogy, University of Vienna * Alexandrite (variety of chrysoberyl): – Tsar Alexander II of Russia (1818–1881) *Alforsite: Ba5Cl(PO4)3 – American geologist John T. Alfors (1930–2005) *Allabogdanite: (Fe,Ni)2P – Alla Bogdanova, Geological Ins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Minerals Recognized By The International Mineralogical Association
Mineralogy is an active science in which minerals are discovered or recognised on a regular basis. Use of old mineral names is also discontinued, for example when a name is no longer considered valid. Therefore, a list of recognised mineral species is never complete. Minerals are distinguished by various chemical and physical properties. Differences in chemical composition and crystal structure distinguish the various ''species''. Within a mineral species there may be variation in physical properties or minor amounts of impurities that are recognized by mineralogists or wider society as a mineral ''variety''. The International Mineralogical Association (IMA) is the international scientific group that recognises new minerals and new mineral names. However, minerals discovered before 1959 did not go through the official naming procedure. Some minerals published previously have been either confirmed or discredited since that date. This list contains a mixture of mineral names that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermogravimetric Analysis
Thermogravimetric analysis or thermal gravimetric analysis (TGA) is a method of thermal analysis in which the mass of a sample is measured over time as the temperature changes. This measurement provides information about physical phenomena, such as phase transitions, absorption, adsorption and desorption; as well as chemical phenomena including chemisorptions, thermal decomposition, and solid-gas reactions (e.g., oxidation or reduction). Thermogravimetric analyzer Thermogravimetric analysis (TGA) is conducted on an instrument referred to as a thermogravimetric analyzer. A thermogravimetric analyzer continuously measures mass while the temperature of a sample is changed over time. Mass, temperature, and time are considered base measurements in thermogravimetric analysis while many additional measures may be derived from these three base measurements. A typical thermogravimetric analyzer consists of a precision balance with a sample pan located inside a furnace with a programmab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambridge University
, mottoeng = Literal: From here, light and sacred draughts. Non literal: From this place, we gain enlightenment and precious knowledge. , established = , other_name = The Chancellor, Masters and Scholars of the University of Cambridge , type = Public research university , endowment = £7.121 billion (including colleges) , budget = £2.308 billion (excluding colleges) , chancellor = The Lord Sainsbury of Turville , vice_chancellor = Anthony Freeling , students = 24,450 (2020) , undergrad = 12,850 (2020) , postgrad = 11,600 (2020) , city = Cambridge , country = England , campus_type = , sporting_affiliations = The Sporting Blue , colours = Cambridge Blue , website = , logo = University of Cambridge logo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scientist
A scientist is a person who conducts Scientific method, scientific research to advance knowledge in an Branches of science, area of the natural sciences. In classical antiquity, there was no real ancient analog of a modern scientist. Instead, philosophers engaged in the philosophical study of nature called natural philosophy, a precursor of natural science. Though Thales (circa 624-545 BC) was arguably the first scientist for describing how cosmic events may be seen as natural, not necessarily caused by gods,Frank N. Magill''The Ancient World: Dictionary of World Biography'', Volume 1 Routledge, 2003 it was not until the 19th century in science, 19th century that the term ''scientist'' came into regular use after it was coined by the theologian, philosopher, and historian of science William Whewell in 1833. In modern times, many scientists have Terminal degree, advanced degrees in an area of science and pursue careers in various Sector (economic), sectors of the economy such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymath
A polymath ( el, πολυμαθής, , "having learned much"; la, homo universalis, "universal human") is an individual whose knowledge spans a substantial number of subjects, known to draw on complex bodies of knowledge to solve specific problems. In Western Europe, the first work to use the term polymathy in its title () was published in 1603 by Johann von Wowern, a Hamburg philosopher. Von Wowern defined polymathy as "knowledge of various matters, drawn from all kinds of studies ... ranging freely through all the fields of the disciplines, as far as the human mind, with unwearied industry, is able to pursue them". Von Wowern lists erudition, literature, philology, philomathy, and polyhistory as synonyms. The earliest recorded use of the term in the English language is from 1624, in the second edition of ''The Anatomy of Melancholy'' by Robert Burton; the form ''polymathist'' is slightly older, first appearing in the ''Diatribae upon the first part of the late History ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
