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MnSi
Brownleeite is a silicide mineral with chemical formula MnSi. It was discovered by researchers of the Johnson Space Center in Houston while analyzing the Pi Puppid particle shower of the comet 26P/Grigg-Skjellerup. The only other known natural manganese silicide is mavlyanovite, Mn5Si3. Overview The particles were collected from the stratosphere over south-western US in April 2003 using an ER-2 high-altitude research aircraft of NASA. The team of researchers from USA, Germany and Japan was led by NASA scientist Keiko Nakamura-Messenger. To determine the mineral's origin and examine other dust materials, a new transmission electron microscope was installed in 2005 at Johnson Space Center. The mineral name was approved by the International Mineralogical Association (IMA Number 2008-011). The NASA scientists named the mineral after Donald E. Brownlee, professor of astronomy at the University of Washington, Seattle, because of his pioneering research on interplanetary dust par ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manganese Monosilicide
Manganese monosilicide (MnSi) is an intermetallic compound, a silicide of manganese. It occurs in cosmic dust as the mineral brownleeite. MnSi has a cubic crystal lattice with no inversion center; therefore its crystal structure is helical, with right-hand and left-hand chiralities. MnSi is a paramagnetic metal that turns into a ferromagnet at cryogenic temperatures below 29 K. In the ferromagnetic state, the spatial arrangement of electron spins in MnSi changes with magnetic field, forming helical, conical, skyrmion, and regular ferromagnetic phases. Crystal structure and magnetism Manganese monosilicide is a non-stoichiometric compound, meaning that the 1:1 Mn:Si composition, lattice constant and many other properties vary depending on the synthesis and processing history of the crystal. MnSi has a cubic crystal lattice with no inversion center; therefore its crystal structure is helical, with right-hand and left-hand chiralities. At low temperatures and magnetic fields ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mavlyanovite
Mavlyanovite is a manganese-silicon mineral with formula Mn5Si3. It was named after Gani Mavlyanov, an Uzbek geologist who lived from 1910 to 1988. Transition metal silicides represent a rich variety of intermetallic compounds with specific crystal and electronic structures owing to the strong interaction between metals and silicon. Recently, transition metal silicides have gained considerable attention from the scientific community because of their unique physicochemical properties such as high thermal stability, excellent Electrical conductivity, electronic conductivity, low Electrical resistivity and conductivity, electrical resistivity, high strength, good thermodynamic stability, good oxidation, and corrosion resistance. With these favorable properties, transition metal silicides are potential candidates for various nanotechnological applications such as electronics, spintronics, thermoelectrics, and solar energy harvesting. Among all transition metal silicides, manganese sil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cubic Crystal System
In crystallography, the cubic (or isometric) crystal system is a crystal system where the unit cell is in the shape of a cube. This is one of the most common and simplest shapes found in crystals and minerals. There are three main varieties of these crystals: *Primitive cubic (abbreviated ''cP'' and alternatively called simple cubic) *Body-centered cubic (abbreviated ''cI'' or bcc) *Face-centered cubic (abbreviated ''cF'' or fcc, and alternatively called ''cubic close-packed'' or ccp) Each is subdivided into other variants listed below. Although the ''unit cells'' in these crystals are conventionally taken to be cubes, the primitive unit cells often are not. Bravais lattices The three Bravais lattices in the cubic crystal system are: The primitive cubic lattice (cP) consists of one lattice point on each corner of the cube; this means each simple cubic unit cell has in total one lattice point. Each atom at a lattice point is then shared equally between eight adjacent c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silicide
A silicide is a type of chemical compound that combines silicon and a (usually) more electropositive element. Silicon is more electropositive than carbon. Silicides are structurally closer to borides than to carbides. Similar to borides and carbides, the composition of silicides cannot be easily specified as covalent molecules. The chemical bonds in silicides range from conductive metal-like structures to covalent or ionic. Silicides of all non-transition metals, with exception of beryllium, have been described. Overview Silicon atoms in silicides can have many possible organizations: *Isolated silicon atoms: electrically conductive (or semiconductive) CrSi, MnSi, FeSi, CoSi, , , , , and nonconductive , *Si2 pairs: , hafnium and thorium silicides *Si4 tetrahedra: KSi, RbSi, CsSi *Si''n'' chains: USi, , CaSi, SrSi, YSi *Planar hexagonal graphite-like Si layers: β-USi2, silicides of other lanthanoids and actinoids *Corrugated hexagonal Si layers: CaSi2 *Open three-di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keiko Nakamura-Messenger
{{disambiguation ...
Keiko may refer to: *Keiko (given name), a feminine Japanese given name *Emperor Keiko *Keiko (orca), a performing killer whale best known for the film ''Free Willy'' ** "Keiko" (song), a single by Lucerito dedicated to Keiko the orca *Keiko (musician), the lead vocalist of the Japanese band Globe *Keiko eiga, Japanese tendency film *Keiko O'Brien, fictional character in 1990s ''Star Trek'' TV shows ''The Next Generation'' and ''Deep Space Nine'' * ''Keiko'' (film), a 1979 Japanese film * Keiko, a kind of Japanese armour * Keiko Fujimori, Peruvian politician and daughter of Alberto Fujimori See also * Kiko (other) *Quico (other) Quico or Quicos may refer to: People * Quico (footballer) (José Antonio Ruiz Palácios, born 1961), former Spanish soccer player * Quico Canseco (born 1949), American politician * Quico Chacón (born 1934), former professional footballer who pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cubic Minerals
Cubic may refer to: Science and mathematics * Cube (algebra), "cubic" measurement * Cube, a three-dimensional solid object bounded by six square faces, facets or sides, with three meeting at each vertex ** Cubic crystal system, a crystal system where the unit cell is in the shape of a cube * Cubic function, a polynomial function of degree three * Cubic equation, a polynomial equation (reducible to ''ax''3 + ''bx''2 + ''cx'' + ''d'' = 0) * Cubic form, a homogeneous polynomial of degree 3 * Cubic graph (mathematics - graph theory), a graph where all vertices have degree 3 * Cubic plane curve (mathematics), a plane algebraic curve ''C'' defined by a cubic equation * Cubic reciprocity (mathematics - number theory), a theorem analogous to quadratic reciprocity * Cubic surface, an algebraic surface in three-dimensional space * Cubic zirconia, in geology, a mineral that is widely synthesized for use as a diamond simulacra * CUBIC, a histology method Computing * Cubic IDE, a modu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Native Element Minerals
Native element minerals are those elements that occur in nature in uncombined form with a distinct mineral structure. The elemental class includes metals, intermetallic compounds, alloys, metalloids, and nonmetals. The Nickel–Strunz classification system also includes the naturally occurring phosphides, silicides, nitrides, carbides, and arsenides. Elements The following elements occur as native element minerals or alloys: Nickel–Strunz Classification -01- Native elements This list uses the Classification of Nickel–Strunz (mindat.org, 10 ed, pending publication). ;Abbreviations: * "*" – discredited (IMA/CNMNC status). * "?" – questionable/doubtful (IMA/CNMNC status). * "REE" – Rare-earth element (Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) * "PGE" – Platinum-group element (Ru, Rh, Pd, Os, Ir, Pt) * 03.C Aluminofluorides, 06 Borates, 08 Vanadates (04.H V ,6/sup> Vanadates), 09 Silicates: ** Neso: insular (from Greek νη ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manganese(IV) Minerals
Manganese is a chemical element with the symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of industrial alloy uses, particularly in stainless steels. It improves strength, workability, and resistance to wear. Manganese oxide is used as an oxidising agent; as a rubber additive; and in glass making, fertilisers, and ceramics. Manganese sulfate can be used as a fungicide. Manganese is also an essential human dietary element, important in macronutrient metabolism, bone formation, and free radical defense systems. It is a critical component in dozens of proteins and enzymes. It is found mostly in the bones, but also the liver, kidneys, and brain. In the human brain, the manganese is bound to manganese metalloproteins, most notably glutamine synthetase in astrocytes. Manganese was first isolated in 1774. It is familiar in the laboratory in the form of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comet Dust
Comet dust refers to cosmic dust that originates from a comet. Comet dust can provide clues to comets' origin. When the Earth passes through a comet dust trail, it can produce a meteor shower. Physical characteristics Size The majority of dust from comet activity is sub-micrometer to roughly micrometer in size. However, this fraction is short-lived, as radiation pressure causes them to blow out of the Solar System or spiral inwards. The next size class is large, "fluffy" or "cluster-type" aggregates of the above grains. These are typically 20-100 micrometers, a size not arbitrary but observed as the porous aggregates tend to fracture or compact. Larger particles are micrometeoroids, not dust. "...in practice the term is most often applied to objects smaller than approximately 100 um. These size ranges need to be modified." "By this definition, IDPs are particles smaller than 10um."" In the absence of a definition from the IAU, groups devised their own definitions of dust: small ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Washington
The University of Washington (UW, simply Washington, or informally U-Dub) is a public research university in Seattle, Washington. Founded in 1861, Washington is one of the oldest universities on the West Coast; it was established in Seattle approximately a decade after the city's founding. The university has a 703 acre main campus located in the city's University District, as well as campuses in Tacoma and Bothell. Overall, UW encompasses over 500 buildings and over 20 million gross square footage of space, including one of the largest library systems in the world with more than 26 university libraries, art centers, museums, laboratories, lecture halls, and stadiums. The university offers degrees through 140 departments, and functions on a quarter system. Washington is the flagship institution of the six public universities in Washington state. It is known for its medical, engineering, and scientific research. Washington is a member of the Association of American Univ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Donald E
Donald is a masculine given name derived from the Gaelic name ''Dòmhnall''.. This comes from the Proto-Celtic *''Dumno-ualos'' ("world-ruler" or "world-wielder"). The final -''d'' in ''Donald'' is partly derived from a misinterpretation of the Gaelic pronunciation by English speakers, and partly associated with the spelling of similar-sounding Germanic names, such as ''Ronald''. A short form of ''Donald'' is '' Don''. Pet forms of ''Donald'' include ''Donnie'' and ''Donny''. The feminine given name ''Donella'' is derived from ''Donald''. ''Donald'' has cognates in other Celtic languages: Modern Irish ''Dónal'' (anglicised as ''Donal'' and ''Donall'');. Scottish Gaelic ''Dòmhnall'', ''Domhnull'' and ''Dòmhnull''; Welsh '' Dyfnwal'' and Cumbric ''Dumnagual''. Although the feminine given name '' Donna'' is sometimes used as a feminine form of ''Donald'', the names are not etymologically related. Variations Kings and noblemen Domnall or Domhnall is the name of many ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Mineralogical Association
Founded in 1958, the International Mineralogical Association (IMA) is an international group of 40 national societies. The goal is to promote the science of mineralogy and to standardize the nomenclature of the 5000 plus known mineral species. The IMA is affiliated with the International Union of Geological Sciences (IUGS). The Association supports the activities of Commissions and Working Groups involved on certain aspects of mineralogical practice and facilitates interactions among mineralogists by sponsoring and organising meetings. In particular, the IMA holds its general meeting every four years. The next meeting is scheduled in 2022 in Lyon, France. Presidents The presidents of the IMA have been: * since 2021: Anhuai Lu ** Peking University *2018–2020: Patrick Cordier (born 1961) ** Université de Lille *2016–2018: Peter C. Burns ** University of Notre Dame *2014–2016: Sergey V. Krivovichev (born 1972) ** Saint Petersburg State University *2012–2014: Walter V. Mar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
