Diamond is a solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. At room temperature and pressure, another solid form of carbon known as graphite is the chemically stable form, but diamond never converts to it. Diamond has the highest hardness and thermal conductivity of any natural material, properties that are utilized in major industrial applications such as cutting and polishing tools, they are the reason that diamond anvil cells can subject materials to pressures found deep in the Earth. Because the arrangement of atoms in diamond is rigid, few types of impurity can contaminate it. Small numbers of defects or impurities color diamond blue, brown, purple, orange or red. Diamond has high optical dispersion. Most natural diamonds have ages between 1 3.5 billion years. Most were formed at depths between 150 and 250 kilometres in the Earth's mantle, although a few have come from as deep as 800 kilometres. Under high pressure and temperature, carbon-containing fluids dissolved minerals and replaced them with diamonds.
Much more they were carried to the surface in volcanic eruptions and deposited in igneous rocks known as kimberlites and lamproites. Synthetic diamonds can be grown from high-purity carbon under high pressures and temperatures or from hydrocarbon gas by chemical vapor deposition. Imitation diamonds can be made out of materials such as cubic zirconia and silicon carbide. Natural and imitation diamonds are most distinguished using optical techniques or thermal conductivity measurements. Diamond is a solid form of pure carbon with its atoms arranged in a crystal. Solid carbon comes in different forms known as allotropes depending on the type of chemical bond; the two most common allotropes of pure carbon are graphite. In graphite the bonds are sp2 orbital hybrids and the atoms form in planes with each bound to three nearest neighbors 120 degrees apart. In diamond they are sp3 and the atoms form tetrahedra with each bound to four nearest neighbors. Tetrahedra are rigid, the bonds are strong, of all known substances diamond has the greatest number of atoms per unit volume, why it is both the hardest and the least compressible.
It has a high density, ranging from 3150 to 3530 kilograms per cubic metre in natural diamonds and 3520 kg/m³ in pure diamond. In graphite, the bonds between nearest neighbors are stronger but the bonds between planes are weak, so the planes can slip past each other. Thus, graphite is much softer than diamond. However, the stronger bonds make graphite less flammable. Diamonds have been adapted for many uses because of the material's exceptional physical characteristics. Of all known substances, it is the least compressible, it has the highest sound velocity. It has low adhesion and friction, its coefficient of thermal expansion is low, its optical transparency extends from the far infrared to the deep ultraviolet and it has high optical dispersion. It has high electrical resistance, it is chemically inert, not reacting with most corrosive substances, has excellent biological compatibility. The equilibrium pressure and temperature conditions for a transition between graphite and diamond is well established theoretically and experimentally.
The pressure changes linearly between 1.7 GPa at 0 K and 12 GPa at 5000 K. However, the phases have a wide region about this line where they can coexist. At normal temperature and pressure, 20 °C and 1 standard atmosphere, the stable phase of carbon is graphite, but diamond is metastable and its rate of conversion to graphite is negligible. However, at temperatures above about 4500 K, diamond converts to graphite. Rapid conversion of graphite to diamond requires pressures well above the equilibrium line: at 2000 K, a pressure of 35 GPa is needed. Above the triple point, the melting point of diamond increases with increasing pressure. At high pressures and germanium have a BC8 body-centered cubic crystal structure, a similar structure is predicted for carbon at high pressures. At 0 K, the transition is predicted to occur at 1100 GPa; the most common crystal structure of diamond is called diamond cubic. It is formed of unit cells stacked together. Although there are 18 atoms in the figure, each corner atom is shared by eight unit cells and each atom in the center of a face is shared by two, so there are a total of eight atoms per unit cell.
Each side of the unit cell is 3.57 angstroms in length. A diamond cubic lattice can be thought of as two interpenetrating face-centered cubic lattices with one displaced by 1/4 of the diagonal along a cubic cell, or as one lattice with two atoms associated with each lattice point. Looked at from a <1 1 1> crystallographic direction, it is formed of layers stacked in a repeating ABCABC... pattern. Diamonds can form an ABAB... structure, known as hexagonal diamond or lonsdaleite, but this is far less common and is formed under different conditions from cubic carbon. Diamonds occur most as euhedral or rounded octahedra and twinned octahedra known as macles; as diamond's crystal structure has a cubic arrangement of the atoms, they have many facets that belong to a cube, rhombicosidodecahedron, tetrakis hexahedron or disdyakis dodecahedron. The crystals can
Nancy Valverde is a Chicana butch lesbian icon of Los Angeles, CA. Born on March 6, 1932 in Deming, New Mexico, to Mexican American parents, Nancy Valverde and her father moved to Lincoln Heights a predominantly Chicano neighborhood in Los Angeles when she was nine years old. Nancy started working at the age of eleven picking apricots and cotton in Santa Paula and Tulare County, California. At thirteen, she assisted the women who worked in the kitchen at a local neighborhood restaurant, where she continued to work when the restaurant switched owners and became a Mexican owned bakery. Though she did not have a driver's license, she worked driving pastry deliveries around Los Angeles. At the age of seventeen, she worked as a manager for an apartment complex, after first working for the apartment complex doing painting jobs, she became a barber. Since she had not completed her education beyond elementary school, she could not enter barber school, but upon passing an IQ test, she received her barbers license.
Though she was paid less than her male colleagues, it was her work at a local barbershop in East Los Angeles that made her famous. Nancy experienced discrimination as a lesbian; as a masculine presenting woman, with short hair and masculine clothing, she was harassed by the LAPD, who charged her with violating masquerading laws, which prohibited men and women from wearing gender nonconforming clothes. Nancy, who identifies as a woman, chose to wear men's clothing for comfort, was targeted because of her masculine presentation, she was harassed and detained multiple times in a section of the Lincoln Heights Jail known as the Daddy Tank, where masculine presenting women and lesbians were held. After doing research at the Los Angeles County Law Library in 1951, she found legal proof that it was not in fact a crime for a women to wear men's clothing, her lawyer used this to end the ongoing arrests. Despite being known and well liked by community members, she was nonetheless discriminated against for being a lesbian.
After the police ceased the arrests, they would knock on the window of her barber shop on Brooklyn Avenue with their nightsticks. Nancy raised four boys. Nancy Valverde has become the subject of historians of LGBT histories, she has been featured in a number of documentaries, book chapters and performances. Lillian Faderman & Stuart Timmon, Gay L. A.: A History of Sexual Outlaws, Power Politics, Lipstick Lesbians. New York: Basic Books, 2006 Tom De Simone, Teresa Wang, Melissa Lopez, Diem Tran, Andy Sacher, Kersu Dalal, Justin Emerick, Lavender Los Angeles: Roots of Equality, South Carolina: Arcadia Publishing, 2011. Karen Tongson, Relocations: Queer Suburban Imaginaries, New York: New York University Press, 2011. Marie Carter, You are My Religion: Women, Gay Bars, Theology Before Stonewall, London & New York: Taylor & Francis Group Routledge, 2014. "A Gender Variance Who's Who: Essays on trans, intersex and other persons and topics from a trans perspective," Zagria blog post 30 Jan 2013, https://zagria.blogspot.com/2013/01/nancy-valverde-1932-barber.html#.
W_AzAehKhnI "Nancy From Eastside Clover, Lincoln Heights," Barrio Boychik blog entry June 30, 2017, https://barrioboychik.com/2017/06/30/nancy-from-eastside-clover-lincoln-heights-queer-history-ela/ Daniel Reynolds, "9 Tales of Young Love and Old Memories: Nine residents of Gay and Lesbian Elder Housing share stories of love from the past and present," Advocate, Aug. 29, 2013, https://www.advocate.com/society/people/2013/08/29/lgbt-seniors-share-9-tales-young-love "The Barber of East L. A." written by Raquel Gutiérrez. Performed by Butchalis de Panochtitlan, 2009. Glenne McElhinney, On These Shoulders We Stand, with 10 others. US 75 mins 2009. Kimberly Esslinger, The HomoFiles, wr. Marie Cartier, episode 2, 2017. Gregorio Davila, LA Queer History, NANCY from East Side CLOVER, 2015
The gizzard referred to as the ventriculus, gastric mill, gigerium, is an organ found in the digestive tract of some animals, including archosaurs, some gastropods, some fish, some crustaceans. This specialized stomach constructed of thick muscular walls is used for grinding up food aided by particles of stone or grit. In certain insects and molluscs, the gizzard features chitinous teeth; the word gizzard comes from the Middle English giser, which derives from a similar word in Old French gésier, which itself evolved from the Latin gigeria, meaning giblets. Birds store it in their crop if necessary; the food passes into their glandular stomach called the proventriculus, sometimes referred to as the true stomach. This is the secretory part of the stomach; the food passes into the gizzard. The gizzard can grind the food with swallowed stones and pass it back to the true stomach, vice versa. In layman's terms, the gizzard'chews' the food for the bird as it does not have teeth to chew food the way humans and other mammals do.
Bird gizzards are lined with a tough layer made of the carbohydrate-protein complex koilin, to protect the muscles in the gizzard. By comparison, while in birds the stomach occurs in the digestive tract prior to the gizzard, in grasshoppers the gizzard occurs prior to the stomach, while in earthworms there is only a gizzard, no stomach; some animals that lack teeth will grit to aid in fragmenting hard foods. All birds have gizzards; those that do employ the following method of chewing: A bird swallows small bits of gravel that act as'teeth' in the gizzard, breaking down hard food such as seeds and thus helping digestion. These stones are called gizzard stones or gastroliths and become round and smooth from the polishing action in the animal's stomach; when too smooth to do their required work, they may be regurgitated. The mullet found in estuarine waters worldwide, the gizzard or mud shad, found in freshwater lakes and streams from New York to Mexico, have gizzards; the gillaroo, a richly colored species of trout found in Lough Melvin, a lake in the north of Ireland, has a gizzard, used to aid the digestion of water snails, the main component of its diet.
Alligators and crocodiles have gizzards. Earthworms have gizzards. All birds have gizzards; the gizzards of emus, chickens and ducks are most notable in cuisine. Some crustaceans have a gizzard although this is referred to as a gastric mill. Dinosaurs that are believed to have had gizzards based on the discovery of gizzard stones recovered near fossils include: Psittacosaurus Massospondylus Sellosaurus Omeisaurus Apatosaurus Barosaurus Dicraeosaurus SeismosaurusThe belief that Claosaurus had a gizzard has been discredited on the grounds that the fossil remains this claim was based on were another species and the stones from a stream. At least some pterosaurs had gizzards; the most notable cases are Rhamphorhynchus. Poultry gizzards are a popular food throughout the world. Grilled chicken gizzards are sold throughout Southeast Asia. Giblets consist of the heart and gizzard of a bird, are eaten themselves or used as the basis for a soup or stock. Gizzard and mashed potato is a popular food in many European countries.
Stewed gizzards are eaten as a snack in Portugal. In Hungary, it is made with paprika. In France the Dordogne region, duck gizzards are eaten in the traditional Périgordian salad, along with walnuts and lettuce. In Italy, gizzards are used mixed with other offal. In Yiddish, gizzards are referred to as pipik'lach meaning navels; the gizzards of kosher species of birds have a green or yellowish membrane lining the inside, which must be peeled off before cooking, as it lends a bitter taste to the food. In traditional Eastern European Jewish cuisine, the gizzards and feet of chickens were cooked together, although not the liver, which per kosher law must be broiled. Kosher butchers sell roasting chickens with the gizzard and feet butchered and left in the cavity to be used for making chicken soup. In Indonesia and liver are considered part of a complete fried poultry dish. In Japan, gizzard is called zuri or sunagimo. In Kyushu, gizzard is fried into karaage. In Korea, chicken gizzard, called dak-ttongjip, is eaten as anju or yasik.
In some places, it is prepared raw and eaten mixed with onion. In Taiwan, gizzards are slow-cooked and served hot or cold in slices, with green onions and soy sauce. In Mainland China, duck gizzard is a common snack, eaten alongside other duck parts such as feet, heart, tongue, or head. Areas famous for their gizzard are Hubei provinces. Wuhan city in Hubei is famous for its brand of spicy gizzard, called jiujiuya. In Northern China, one can find barbecued duck gizzard; the word sangdana is used to refer to chicken gizzards in Northern India and Pakistan. The word is derived from Persian. Another name for it is pathri, it may be served cooked in a curry, while barbecued skewered gizzards are popular. In Iran, some kebab restaurants mix chicken gizzards in their koobideh kebabs to increase the meat content. In Nepal, gizzard is called pangra, it is eaten most with drinks. In P