Biomineralization Glomerula piloseta (Sabellidae), longitudinal section of the tube, aragonitic spherulitic prismatic structure IUPAC definition Mineralization caused by cell-mediated phenomena.[1][a] Biomineralization is the process by which living organisms produce minerals, [2]often to harden or stiffen existing tissues. In terms of taxonomic distribution, the most common biominerals are the phosphate and carbonate salts of calcium that are used in conjunction with organic polymers such as collagen and chitin to give structural support to bones and shells.[6] The structures of these biocomposite materials are highly controlled from the nanometer to the macroscopic level, resulting in complex architectures that provide multifunctional properties. Biological roles[edit] Biominerals perform a variety of roles in organisms, the most important being support, defense and feeding.[9] Biology[edit] Shell formation in molluscs[edit] Chemistry[edit] Evolution[edit] Astrobiology[edit] Potential applications[edit] [edit]
Royal Society of Chemistry | Advancing the Chemical Sciences vasp documentation The VASP Manual The online VASP manual is a lengthy document generated with latex2html. If you're one of those die-hards that like real paper you might prefer to get a pdf copy of the manual. Recently, we started a wiki, that in future will replace the online manual completely. VASP Workshop Lectures In 2003 we organized a VASP workshop. More recently the CSC-IT Center for Science Ltd. in Espoo, Finland, organized two VASP workshops (2006/2009). Technical Support Technical support is offered as a courtesy only (not as a contractual service). Alum (douple sulfate) Bulk alum Chemical properties[edit] Uses[edit] Industrial uses[edit] Alum has been used at least since Roman times for purification of drinking water[2] and industrial process water. Cosmetic[edit] Alum in block form (usually potassium alum) can be used as a blood coagulant.[5]Styptic pencils containing aluminium sulfate or potassium aluminium sulfate are used as astringents to prevent bleeding from small shaving cuts.Alum may be used in depilatory waxes used for the removal of body hair or applied to freshly waxed skin as a soothing agent.In the 1950s, men sporting crewcut or flattop hairstyles sometimes applied alum to their hair as an alternative to pomade[citation needed]. Culinary[edit] Flame retardant[edit] Solutions containing alum may be used to treat cloth, wood, and paper materials to increase their resistance to fire.Alum is also used in fire extinguishers to smother chemical and oil fires. Chemical flocculant[edit] Taxidermy[edit] Medicine[edit] Art[edit] History[edit] After M.H.
The Elements Revealed: An Interactive Periodic Table In the October 2011 issue of Scientific American, we celebrate the International Year of Chemistry. Learn more about its impact on our daily lives in our Special Report. UPDATED: 06/18/2013 In honor of the 2013 Lindau meeting, which focuses on chemistry, we have updated our interactive periodic table with links to Nature Chemistry's In Your Element essay series. Each essay tells the story of a particular element, often describing its discovery, history and eventual uses. Main Sources & More to Explore: The Poisoner’s Handbook: Murder and the Birth of Forensic Medicine in Jazz Age New York. Interactive by Krista Fuentes Davide Castelvecchi Davide Castelvecchi is a freelance science writer based in Rome and a contributing editor for Scientific American magazine.
Scripts - Vasp Tools - Chem & Biochem - UT Austin This script sums up the atomic projected DOS over some group of atoms, and then calculates the center of the specific band using a weighted average. The default is set to calcualted the center for the whole band. However, it can also consider DOS within a user specified range by using the optional "w=" or "e=" flag. By using "e=emin,emax" flag, only the states in ranger [emin,emax] are considered. By using "w=" flag, the script finds a half width for the band at half the max height and, based on the number following w= , calculates a weighted average within the limits of that many half widths at half height from the center. If no orbital flag is specified, the script analyzes the d-band. Note: the split_dos.ksh script should be run first to get the resulting new files labeled as DOS1, DOS2, ..., DOSN,where N is the number of atoms in the unit cell.
Soil Soil is the mixture of minerals, organic matter, gases, liquids and a myriad of micro- and macro- organisms that can support plant life. It is a natural body that exists as part of the pedosphere and it performs four important functions: it is a medium for plant growth; it is a means of water storage, supply and purification; it is a modifier of the atmosphere; and it is a habitat for organisms that take part in decomposition and creation of a habitat for other organisms. Soil is considered the "skin of the earth" with interfaces between the lithosphere, hydrosphere, atmosphere, and biosphere.[1] Soil consists of a solid phase (minerals & organic matter) as well as a porous phase that holds gases and water.[2][3][4] Accordingly, soils are often treated as a three-state system.[5] Overview[edit] Soil is a major component of the Earth's ecosystem. Soils can effectively remove impurities, kill disease agents, and degrade contaminants. History of the study of soil[edit] In 1856 J. Curtis F.
ChemWiki: The Dynamic Chemistry Textbook - ChemWiki ICSD Ilmenite Crystal structure of ilmenite Ilmenite is a weakly magnetic titanium-iron oxide mineral which is iron-black or steel-gray. It is a crystalline iron titanium oxide (FeTiO 3). Distinguishing features[edit] Ilmenite is commonly recognized in altered igneous rocks by the presence of a white alteration product, the pseudo-mineral leucoxene. In reflected light it may be distinguished from magnetite by more pronounced reflection pleochroism and a brown-pink tinge. Ilmenite is weakly magnetic, with a weak response to a hand magnet. Mineral chemistry[edit] Ilmenite from Froland, Aust-Agder, Norway; 4.1 x 4.1 x 3.8 cm Ilmenite most often contains appreciable quantities of magnesium and manganese and the full chemical formula can be expressed as (Fe,Mg,Mn,Ti)O3. At higher temperatures it has been demonstrated there is a complete solid solution between ilmenite and hematite. Altered ilmenite forms the mineral leucoxene, an important source of titanium in heavy mineral sands ore deposits.
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