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ANAPC2	Interactions	ANAPC2 has been shown to interact with ANAPC1 and ANAPC11.
Far-eastern blot	Far-eastern blot	The far-eastern blot, or far-eastern blotting, is a technique for the analysis of lipids separated by high-performance thin layer chromatography (HPTLC). When executing the technique, lipids are transferred from HPTLC plates to a PVDF membrane for further analysis, for example by enzymatic or ligand binding assays and mass spectrometry. It was developed in 1994 by Taki and colleagues at the Tokyo Medical and Dental University, Japan.
Far-eastern blot	Analysis	Cholesterol, glycerophospholipids and sphingolipids are major constituents of the cell membrane and in certain cases function as second messengers in cell proliferation, apoptosis and cell adhesion in inflammation and tumor metastasis. Far-eastern blot was established as a method for transferring lipids from an HPTLC plate to a polyvinylidene difluoride (PVDF) membrane within a minute. Applications of this with other methods have been studied. Far-eastern blotting allows for the purification of glycosphingolipids and phospholipids, structural analysis of lipids in conjunction with direct mass spectrometry, binding studies using various ligands such as antibodies, lectins, bacterium, viruses, and toxins, and enzyme reaction on membranes.
Far-eastern blot	Analysis	Far-eastern blot is adaptable to the analysis of lipids as well as metabolites of drugs and natural compounds from plants and environmental hormones.
Far-eastern blot	Etymology	The name is a dual reference to eastern blot and the geographical concept of the Far East (which includes Japan).
Fuculose	Fuculose	Fuculose or 6-deoxy-tagatose is a ketohexose deoxy sugar. Fuculose is involved in the process of sugar metabolism. l-Fuculose can be formed from l-fucose by l-fucose isomerase and converted to L-fuculose-1-phosphate by l-fuculose kinase.
Hermite transform	Hermite transform	In mathematics, Hermite transform is an integral transform named after the mathematician Charles Hermite, which uses Hermite polynomials Hn(x) as kernels of the transform. This was first introduced by Lokenath Debnath in 1964.The Hermite transform of a function F(x) is The inverse Hermite transform is given by
Pistoleer	Pistoleer	A pistoleer is a mounted soldier trained to use a pistol, or more generally anyone armed with such a weapon. It is derived from pistolier, a French word for an expert marksman.
Pistoleer	History	The earliest kind of pistoleer was the mounted German Reiter, who came to prominence in Europe after the Battle of St. Quentin in 1557. These soldiers were equipped with a number of single-shot, muzzle-loader wheel-lock or Snaphance horse pistols, amongst the most advanced weapons of the era. Although mounted Pistoleers were effective against heavy cavalry, they gradually fell out of use during the Thirty Years War. After this time, cavalry in Western armies used swords or lances as their primary arm, although they still generally carried a pistol as a sidearm.During the English Civil War, the Roundhead Ironside cavalry were issued with a pair of flintlock pistols. Cavaliers used similar weapons, often ornately decorated, including an early breechloader with a barrel that could be unscrewed.Before 1700, cavalrymen were recruited from the wealthy gentry, and generally purchased their own nonstandard pistols. The industrial revolution enabled armies to mass-produce firearms with interchangeable parts, and cheaply issue large quantities of standardised firearms to enlisted personnel. However, officers in the British Army and Royal Navy continued to privately commission pistols from London gunsmiths such as Joseph Manton, Robert Wogdon, Henry Nock and Durs Egg until the mid 19th century.
Pistoleer	Equipment	Light cavalry of the early modern period were equipped with a sabre and specialised horse pistols, carried in saddle holsters. These large calibre single shot handguns, also known as holster pistols, horsemen's pistols, cavalry pistols or musket calibre pistols, saw extensive use among the British and French armies during the Napoleonic Wars. These were deadliest at close range, but massed pistol fire from horseback proved moderately effective at medium range. Many were made in .71, .65 and .58 calibre, to enable the use of standard infantry musket balls.During the early Victorian era, most horse pistols in the arsenals of Britain, France and America were converted to caplock ignition. These remained in service until .44 calibre revolvers such as the Colt Dragoon of 1847 or the Adams revolver of 1851 were introduced.
Pistoleer	Equipment	British horse pistol Horse pistols made at the Tower of London used the same lock as the Brown Bess musket. Pistols made before 1790 had wood instead of steel ramrods. The lock was stamped with the crown of George III of Great Britain and the barrel received arrow proof marks.Due to the high demand for arms during the wars against France, regulation .71 calibre horse pistols were also manufactured in Birmingham, and by private gunsmiths. Britain's German allies produced similar pistols in .71 and .65 calibre, including the Prussian Potzdam horse pistols of 1733, 1774 and 1789.British light cavalry such as the hussars fought as pistoliers during the Napoleonic Wars, being trained to draw and fire both pistols before closing in with the sabre. Dragoons were issued with a pair, or brace, of pistols as secondary weapons to their carbines. Although designed for use by cavalry, horse pistols were also issued to mounted staff officers for personal defence, and it was a widespread if unauthorised practice for colour sergeants to carry a pistol in addition to the half-pike and spadroon. After the war, surplus horse pistols were issued to the coast guard, customs officers, and the Metropolitan mounted police.
Pistoleer	Equipment	Similar weapons, issued to the Royal Navy as the Sea Service pistol, had brass rather than steel barrels to prevent corrosion, a belt hook, and a brass butt cap for close quarters fighting. Blackbeard the pirate was infamous for carrying seven pistols of this type in a bandolier.
Pistoleer	Equipment	India pattern pistol An improved variant of the regulation .71 Tower horse pistol, known as the Indian pattern, was manufactured in British India from 1787 to 1832, for use by officers of the East India Trading Company and British Indian Cavalry. Indian or New Land Pattern pistols produced after 1802 had captive ramrods, raised waterproof frizzens for use in India's monsoons, and an attachment on the buttcap for a lanyard. These features would later be retro-fitted to the Tower Model 1835 and Model 1840 pistols.Indian horse pistols in .65 and later .577 calibre were produced at British-controlled arsenals such as Lucknow from 1796 to 1856, and were favoured by big game hunters before the invention of the double barreled howdah pistol. Additionally, many were exported to England and saw use during the later years of the Napoleonic Wars. During the Indian Mutiny, caplock conversions of the India pattern pistol with rifled barrels were used by British forces and mutinous sepoys alike.
Pistoleer	Equipment	French and American horse pistols The French army first issued horse pistols to their cavalry in 1733, with an improved model introduced in 1764. French horse pistols were used primarily by cuirassiers, and as a secondary weapon by lancers. During the Napoleonic Wars, the most commonly issued pistols were the Pistolet Modele An. IX of 1798, and the Pistolet Modele An. XIII in service from 1806 to 1840. The latter was half-stocked, had a bird's head grip, and included an attachment for a lanyard. An improved model was introduced in 1822, and was converted to caplock ignition in 1842. Copies of the French An. XIII pistol were manufactured in Holland, Belgium, Switzerland and Prussia and were issued to the armies of those countries from the 1820s onwards.
Pistoleer	Equipment	During the Revolutionary War the Americans manufactured copies of the British horse pistol, and its likely that the 1804-1806 Lewis and Clark Expedition procured horsemen's pistols of this type. British and American horse pistols were also acquired by indigenous American warriors either from dead white men, or through trade.The Americans manufactured their first standardised horse pistol at Harpers Ferry in 1805, copied from the French An. IX pattern. Improved models of the Harpers Ferry pistol were produced in 1806, 1807, 1812, 1818, and 1835. These were issued to the US Army during the War of 1812, Indian Wars and Mexican War, and were used by gunfighters and mountain men in the early days of the Old West, including Kit Carson. The US Navy used similar pistols from 1813 until after the American Civil War, and the Confederate army issued large quantities of Harpers Ferry horse pistols.
Pistoleer	Equipment	Russian horse pistols The hussars of the Tsarist army filled a similar role to their British counterparts, being trained to fight with sword and pistol. Before the standardised Model 1808 horse pistol in 7 Line (.71-inch) caliber was introduced, the Tsarist cavalry were equipped with a mixture of weapons in different calibers, some made before 1700. The Model 1808 pistol was full-stocked, with a brass barrel band, belt hook and the initials of Tsar Alexander I stamped on the buttplate. New pistols were manufactured at Tula, Izhevsk, Sestroretsk, Moscow, Leningrad, and Kiev in 1818, 1824 and 1836, and most older weapons were converted to percussion from 1844 to 1848. Many were painted black as thermal insulation from the Russian winter, and leather wrapped grips were not uncommon.Ukrainian Cossacks were equipped with their own distinctive horse pistol, featuring a miquelet lock imported from Spain or Italy, a stock carved from an elm root, a bulbous ivory or bone butt, and niello silver decoration. These were in use among the Cossacks, Chechens, Georgians, Abkhazians and other inhabitants of the Caucasus from the Russo Turkish Wars of the 17th century until after the Crimean War.Some Cossack tribes of the early 1800s scorned the pistol as the weapon of an inexperienced recruit or coward, but others celebrated skilled pistoliers and assigned the best marksmen to elite companies of dismounted skirmishers. By the 1840s, it had become mandatory for every Ukrainian youth to be as competent in the use of the pistol and carbine as he was with the sabre, lance, wolf hunting, and horse-breaking. Unlike regular cavalry, Cossacks carried their pistols on the left side of their belt or around their neck rather than in a saddle holster so they would never be unarmed if attacked while away from their horses.
Pistoleer	Revival	Horse-mounted pistoleers of a kind made a brief comeback in North America during the American Civil War (particularly by the Confederates) as well as in the Indian Wars of the 1860s and 70s. This was a consequence of the adoption of the multi-shot Colt revolver, which gave horsemen greater range and firepower.
Light ergonomics	Light ergonomics	Light ergonomics is the relationship between the light source and the individual. Poor light can be divided into the following: Individual or socio-cultural expectations Insufficient light Poor distribution of light Improper contrast Glare Flicker Thermal heating (over or under) Acoustic noise (especially fluorescents) Color spectrum (full-spectrum light, color temperature, etc.)
Light ergonomics	Effects of poor light	The effects of poor light can include the following: low productivity high human error rates inability to match or select correct colors eyestrain headache a reduction in mental alertness general malaise low employee morale
Tin foil	Tin foil	Tin foil, also spelled tinfoil, is a thin foil made of tin. Tin foil was superseded after World War II by cheaper and more durable aluminium foil, which is still referred to as "tin foil" in many regions (an example of a misnomer).
Tin foil	History	Foil made from a thin leaf of tin was commercially available before its aluminium counterpart. In the late 19th century and early 20th century, tin foil was in common use, and some people continue to refer to the new product by the name of the old one. Tin foil is stiffer than aluminium foil. It tends to give a slight tin taste to food wrapped in it, which is a major reason it has largely been replaced by aluminium and other materials for wrapping food.
Tin foil	History	Because of its corrosion resistance, oxidation resistance, availability, low cost, low toxicity, and slight malleability, tin foil was used as a filling for tooth cavities prior to the 20th century. The first audio recordings on phonograph cylinders were made on tin foil.
Component video	Component video	Component video is an analog video signal that has been split into two or more component channels. In popular use, it refers to a type of component analog video (CAV) information that is transmitted or stored as three separate signals. Component video can be contrasted with composite video in which all the video information is combined into a single signal that is used in analog television. Like composite, component cables do not carry audio and are often paired with audio cables.
Component video	Component video	When used without any other qualifications, the term component video usually refers to analog YPBPR component video with sync on luma (Y) found on analog high-definition televisions and associated equipment from the 1990s through the 2000s when they were largely replaced with HDMI and other all-digital standards. Component video cables and their RCA jack connectors on equipment are normally color-coded red, green and blue, although the signal is not in RGB. YPbPr component video can be losslessly converted to the RGB signal that internally drives the monitor; the encoding is useful as the Y signal will also work on black and white monitors.
Component video	Analog component video	Reproducing a video signal on a display device (for example, a cathode ray tube; CRT) is a straightforward process complicated by the multitude of signal sources. DVD, VHS, computers and video game consoles all store, process and transmit video signals using different methods, and often each will provide more than one signal option. One way of maintaining signal clarity is by separating the components of a video signal so that they do not interfere with each other. A signal separated in this way is called "component video". S-Video, RGB and YPBPR signals comprise two or more separate signals, and thus are all component-video signals. For most consumer-level video applications, the common three-cable system using BNC or RCA connectors analog component video was used. Typical formats are 480i (480 lines visible, 525 full for NTSC) and 576i (576 lines visible, 625 full for PAL). For personal computer displays the 15 pin DIN connector (IBM VGA) provided screen resolutions including 640×480, 800×600, 1024×768, 1152×864, 1280×1024.
Component video	Analog component video	RGB analog component video The various RGB (red, green, blue) analog component video standards (e.g., RGBS, RGBHV, RGsB) use no compression and impose no real limit on color depth or resolution, but require large bandwidth to carry the signal and contain a lot of redundant data since each channel typically includes much of the same black-and-white image. Early personal computers such as the IBM PS/2 offered this signal via a VGA port. Many televisions, especially in Europe, can utilize RGB via the SCART connector. All arcade video games, other than early vector and black-and-white games, use RGB monitors.In addition to the red, green and blue color signals, RGB requires two additional signals to synchronize the video display. Several methods are used: composite sync, where the horizontal and vertical signals are mixed together on a separate wire (the S in RGBS) separate sync, where the horizontal and vertical are each on their own wire (the H and V in RGBHV; also the acronym HD/VD, meaning horizontal deflection/vertical deflection, is used) sync on green, where a composite sync signal is overlaid on the wire used to transport the green signal (SoG, Sync on G, or RGsB).
Component video	Analog component video	sync on red or sync on blue, where a composite sync signal is overlaid on either the red or blue wire sync on composite (not to be confused with composite sync), where the signal normally used for composite video is used alongside the RGB signal only for the purposes of sync.
Component video	Analog component video	sync on luma, where the Y signal from S-Video is used alongside the RGB signal only for the purposes of sync.Composite sync is common in the European SCART connection scheme (using pins 17 [ground] and 19 [composite-out] or 20 [composite-in]). RGBS requires four wires – red, green, blue and sync. If separate cables are used, the sync cable is usually colored yellow (as is the standard for composite video) or white.
Component video	Analog component video	Separate sync is most common with VGA, used worldwide for analog computer monitors. This is sometimes known as RGBHV, as the horizontal and vertical synchronization pulses are sent in separate channels. This mode requires five conductors. If separate cables are used, the sync lines are usually yellow (H) and white (V), yellow (H) and black (V), or gray (H) and black (V).
Component video	Analog component video	Sync on Green (SoG) is less common, and while some VGA monitors support it, most do not. Sony is a big proponent of SoG, and most of their monitors (and their PlayStation line of video game consoles) use it. Like devices that use composite video or S-video, SoG devices require additional circuitry to remove the sync signal from the green line. A monitor that is not equipped to handle SoG will display an image with an extreme green tint, if any image at all, when given a SoG input.
Component video	Analog component video	Sync on red and sync on blue are even rarer than sync on green, and are typically used only in certain specialized equipment.
Component video	Analog component video	Sync on composite, not to be confused with composite sync, is commonly used on devices that output both composite video and RGB over SCART. The RGB signal is used for color information, while the composite video signal is only used to extract the sync information. This is generally an inferior sync method, as this often causes checkerboards to appear on an image, but the image quality is still much sharper than standalone composite video.
Component video	Analog component video	Sync on luma is much similar to sync on composite, but uses the Y signal from S-Video instead of a composite video signal. This is sometimes used on SCART, since both composite video and S-Video luma ride along the same pins. This generally does not suffer from the same checkerboard issue as sync on composite, and is generally acceptable on devices that do not feature composite sync, such as the Sony PlayStation and some modded Nintendo 64 models.
Component video	Analog component video	Luma-based analog component video Further types of component analog video signals do not use separate red, green and blue components but rather a colorless component, termed luma, which provides brightness information (as in black-and-white video). This combines with one or more color-carrying components, termed chroma, that give only color information. Both the S-Video component video output (two separate signals) and the YPBPR component video output (three separate signals) seen on DVD players are examples of this method.
Component video	Analog component video	Converting video into luma and chroma allows for chroma subsampling, a method used by JPEG and MPEG compression schemes to reduce the storage requirements for images and video (respectively). Many consumer TVs, DVD players, monitors, video projectors and other video devices at one time used YPBPR output or input. When used for connecting a video source to a video display where both support 4:3 and 16:9 display formats, the PAL television standard provides for signaling pulses that will automatically switch the display from one format to the other. Connectors used D-Terminal: Used mostly on Japanese electronics. Three BNC (professional) or RCA connectors (consumer): Typically colored green (Y), blue (PB) and red (PR). SCART used in Europe. Video-in video-out (VIVO): 9-pin Mini-DIN-connectors called "TV Out" in computer video cards, which usually include an adaptor for component RCA, composite RCA and 4-pin S-Video-Mini-DIN.
Component video	Synchronization	Component video requires an extra synchronization signal to be sent along with the video. Component video sync signals can be sent in several different ways: Separate sync Uses separate wires for horizontal and vertical synchronization. When used in RGB (i.e. VGA) connections, five separate signals are sent (Red, Green, Blue, Horz. Sync, Vert. Sync). Composite sync Combines horizontal and vertical synchronization onto one pair of wires. When used in RGB connections, four separate signals are sent (Red, Green, Blue, Sync). Sync-on-green (SOG) Combines composite sync with the green signal in RGB. Only three signals are sent (Red, Green with Sync, Blue). This synchronization system is used in - among other applications - many systems by Silicon Graphics and Sun Microsystems through a DB13W3 connector. Sync-on-luminance Similar to sync-on-green, but combines sync with the luminance signal (Y) of a color system such as YPbPr and S-Video. This is the synchronization system normally used in home theater systems.
Component video	Synchronization	Sync-on-composite The connector carries a standard composite video signal along with the RGB components, for use with devices that cannot process RGB signals. For devices that do understand RGB, the sync component of that composite signal is used along with the color information from the RGB lines. This arrangement is found in the SCART connector in common use in Europe and some other PAL/SECAM areas.
Component video	Digital component video	Digital component video makes use of single cables with signal lines/connector pins dedicated to digital signals, transmitting digital color space values allowing higher resolutions such as 480p, 480i, 576i, 576p, 720p, 1080i, and 1080p.RGB component video has largely been replaced by modern digital formats, such as DisplayPort or Digital Visual Interface (DVI) digital connections, while home theater systems increasingly favor High-Definition Multimedia Interface (HDMI), which support higher resolutions, higher dynamic range, and can be made to support digital rights management. The demise of analog is largely due to screens moving to large flat digital panels as well as the desire for having a single cable for both audio and video, but also due to a slight loss of clarity when converting from a digital media source to analog and back again for a flat digital display, particularly when used at higher resolutions where analog signals are highly susceptible to noise.
Component video	International standards	Examples of international component video standards are: RS-170 RGB (525 lines, based on NTSC timings, now EIA/TIA-343) RS-343 RGB (525, 625 or 875 lines) STANAG 3350 Analogue Video Standard (NATO military version of RS-343 RGB, now EIA-343A) CEA-770.3 High Definition TV Analog Component Video Interface Consumer Electronics Association
Component video	Component versus composite	In a composite signal, such as NTSC, PAL or SECAM, the luminance, Brightness (Y) signal and the chrominance, Color (C) signals are encoded together into one signal. When the color components are kept as separate signals, the video is called component analog video (CAV), which requires three separate signals: the luminance signal (Y) and the color difference signals (R-Y and B-Y).
Component video	Component versus composite	Since component video does not undergo the encoding process, the color quality is noticeably better than composite video.Component video connectors are not unique in that the same connectors are used for several different standards; hence, making a component video connection often does not lead to a satisfactory video signal being transferred. Many DVD players and TVs may need to be set to indicate the type of input/output being used, and if set incorrectly the image may not be properly displayed. Progressive scan, for example, is often not enabled by default, even when component video output is selected.
Scientific essentialism	Scientific essentialism	Scientific essentialism, a view espoused by Saul Kripke and Hilary Putnam, maintains that there exist essential properties that objects possess (or instantiate) necessarily. In other words, having such and such essential properties is a necessary condition for membership in a given natural kind. For example, tigers are tigers in virtue of possessing a particular set of genetic properties, but identifying (or appearance-based) properties are nonessential properties. If a tiger lost a leg, or didn't possess stripes, we would still call it a tiger. They are not necessary for being a member of the class of tigers.
Scientific essentialism	Scientific essentialism	It is important, however, that the set of essential properties of an object not be used to identify or be identified with that object because they are not necessary and sufficient, but only necessary. Having such and such a genetic code does not suffice for being a tiger. We wouldn't call a piece of tiger tail a tiger, even though a piece of tiger tail contains the genetic information essential to being a tiger.
Scientific essentialism	Scientific essentialism	Other advocates of scientific essentialism include Brian Ellis, Caroline Lierse, John Bigelow, and Alexander Bird.
Contemporary architecture	Contemporary architecture	Contemporary architecture is the architecture of the 21st century. No single style is dominant. Contemporary architects work in several different styles, from postmodernism, high-tech architecture and new interpretations of traditional architecture to highly conceptual forms and designs, resembling sculpture on an enormous scale. Some of these styles and approaches make use of very advanced technology and modern building materials, such as tube structures which allow construction of buildings that are taller, lighter and stronger than those in the 20th century, while others prioritize the use of natural and ecological materials like stone, wood and lime. One technology that is common to all forms of contemporary architecture is the use of new techniques of computer-aided design, which allow buildings to be designed and modeled on computers in three dimensions, and constructed with more precision and speed.
Contemporary architecture	Contemporary architecture	Contemporary buildings and styles vary greatly. Some feature concrete structures wrapped in glass or aluminium screens, very asymmetric facades, and cantilevered sections which hang over the street. Skyscrapers twist, or break into crystal-like facets. Facades are designed to shimmer or change color at different times of day.
Contemporary architecture	Contemporary architecture	Whereas the major monuments of modern architecture in the 20th century were mostly concentrated in the United States and western Europe, contemporary architecture is global; important new buildings have been built in China, Russia, Latin America, and particularly in Arab states of the Persian Gulf; the Burj Khalifa in Dubai was the tallest building in the world in 2019, and the Shanghai Tower in China was the second-tallest.
Contemporary architecture	Contemporary architecture	Additionally, in the late 20th century, New Classical Architecture, a traditionalist response to modernist architecture, emerged, continuing into the 21st century. The 21st century saw the emergence of multiple organizations dedicated to the promotion of local and/or traditional architecture. Examples include the International Network for Traditional Building, Architecture & Urbanism (INTBAU), the Institute of Classical Architecture & Art (ICAA), the Driehaus Architecture Prize, and the Complementary architecture movement. New traditional architects include Michael Graves, Léon Krier, Yasmeen Lari, Robert Stern and Abdel-Wahed El-Wakil.
Contemporary architecture	Contemporary architecture	Most of the landmarks of contemporary architecture are the works of a small group of architects who work on an international scale. Many were designed by architects already famous in the late 20th century, including Mario Botta, Frank Gehry, Jean Nouvel, Norman Foster, Ieoh Ming Pei and Renzo Piano, while others are the work of a new generation born during or after World War II, including Zaha Hadid, Santiago Calatrava, Daniel Libeskind, Jacques Herzog, Pierre de Meuron, Rem Koolhaas, and Shigeru Ban. Other projects are the work of collectives of several architects, such as UNStudio and SANAA, or large multinational agencies such as Skidmore, Owings & Merrill, with thirty associate architects and large teams of engineers and designers, and Gensler, with 5,000 employees in 16 countries.
Contemporary architecture	Museums	Some of the most striking and innovative works of contemporary architecture are art museums, which are often examples of sculptural architecture, and are the signature works of major architects. The Quadracci Pavilion of the Milwaukee Art Museum in Milwaukee, Wisconsin, was designed by Spanish architect Santiago Calatrava. Its structure includes a movable, wing-like brise soleil that opens up for a wingspan of 217 feet (66 m) during the day, folding over the tall, arched structure at night or during bad weather.The Walker Art Center in Minneapolis (2005), was designed by the Swiss architects Herzog and de Meuron, who designed the Tate Modern museum in London, and who won the Pritzker Architecture Prize, the most prestigious award in architecture, in 2001. It updates and provides a contrast to the austere earlier Modernist structure designed by Edward Larrabee Barnes by adding a five-story tower clad in panels of delicately sculpted gray aluminum, which change color with the changing light, connecting by a wide glass gallery leading to the older building. It also harmonizes with two stone churches opposite.The Polish-born American architect Daniel Libeskind (born 1946) is one of the most prolific of contemporary museum architects; He was an academic before he began designing buildings and was one of the early proponents of the architectural theory of Deconstructivism. The exterior of his Imperial War Museum North in Manchester, England (2002), has an exterior which resembles, depending upon the light and time of day, huge and broken pieces of earth or armor plates, and is said to symbolize the destruction of war. In 2006 Libeskind finished the Hamilton Building of the Denver Art Museum in Denver Colorado, composed of twenty sloping planes, none of them parallel or perpendicular, covered with 230,000 square feet of titanium panels. Inside, the walls of the galleries are all different, sloping and asymmetric. Libeskind completed another striking museum, the Royal Ontario Museum in Toronto, Ontario, Canada (2007), also known as "The Crystal," a building whose form, resembles a shattered crystal. Libeskind's museums have been both admired and attacked by critics. While admiring many features of the Denver Art Museum, The New York Times' architecture critic Nicolai Ouroussoff wrote that "In a building of canted walls and asymmetrical rooms—tortured geometries generated purely by formal considerations — it is virtually impossible to enjoy the art."The De Young Museum in San Francisco was designed by the Swiss architects Herzog & de Meuron. It opened in 2005, replacing an older structure that was badly damaged in an earthquake in 1989. The new museum was designed to blend with the park's natural landscape and resist strong earthquakes. The building can move up to three feet (91 centimeters) on ball-bearing sliding plates and viscous fluid dampers that absorb kinetic energy.
Contemporary architecture	Museums	The Zentrum Paul Klee by Renzo Piano is an art museum near Berne Switzerland located next to an autoroute in the Swiss countryside. The museum blends into the landscape by taking three rolling hills made of steel and glass. One building houses the gallery (which is almost entirely underground to preserve the fragile drawings of Klee from the effects of sunlight). At the same time, the other two "hills" contain an education center and administrative offices.The Centre Pompidou-Metz, in Metz, France, (2010), a branch of the Centre Pompidou museum of modern art in Paris, was designed by Shigeru Ban, a Japanese architect who won the Pritzker Prize for Architecture in 2014. The roof is the most dramatic feature of the building; it is a 90 m (300 ft) wide hexagon with a surface area of 8,000 m2 (86,000 sq ft), composed of sixteen kilometers of glued laminated timber, that intersect to form hexagonal wooden units resembling the cane-work pattern of a Chinese hat. The roof's geometry is irregular, featuring curves and counter-curves over the entire building, particularly the three exhibition galleries. The entire wooden structure is covered with a white fiberglass membrane, and a coating of teflon protects from direct sunlight and allows light to pass through.
Contemporary architecture	Museums	The Louis Vuitton Foundation by Frank Gehry (2014) is the gallery of contemporary art located adjacent to the Bois de Boulogne in Paris was opened in October 2014. Gehry described his architecture as inspired by the glass Grand Palais of the 1900 Paris Exposition and by the enormous glass greenhouses of the Jardin des Serres d'Auteuil near the park, built by Jean-Camille Formigé in 1894–95. Gehry had to work within strict height and volume restrictions, which required any part of the building over two stories to be made of glass. The building is low because of the height limits, sited in an artificial lake with water cascading beneath the building. The interior gallery structures are covered in a white fiber-reinforced concrete called Ductal. Similar in concept to Gehry's Walt Disney Concert Hall, the building is wrapped in curving glass panels resembling sails inflated by the wind. The glass "Sails" are made of 3,584 laminated glass panels, each one a different shape, specially curved for its place in the design. Inside the sails is a cluster of two-story towers containing 11 galleries of different sizes, with flower garden terraces, and rooftop spaces for displays.The new Whitney Museum of American Art in New York City by Renzo Piano (2015) took a very different approach from the sculptural museums of Frank Gehry. The Whitney has an industrial-looking facade and blends into the neighborhood. Michael Kimmelman, the architecture critic of The New York Times called the building a "mishmash of styles" but noted its similarity to Piano's Centre Pompidou in Paris, in the way that it mixed with the public spaces around it. "Unlike so much big-name architecture," Kimmelman wrote, "it's not some weirdly shaped trophy building into which all the practical stuff of a working museum must be fitted."The San Francisco Museum of Modern Art is actually two buildings by different architects fit together; an earlier (1995) five-story postmodernist structure by the Swiss architect Mario Botta, to which has been joined a much larger ten-story white gallery by the Norwegian-based firm of Snøhetta (2016). The expanded building includes a green living wall of native plants in San Francisco; a free ground-floor gallery with 25-foot (7.6 m) tall glass walls that will place art on view to passersby and glass skylights that flood the upper floors of offices (though not the galleries) with light. The facades clad are with lightweight panels made of Fibre-Reinforced Plastic. The critical reaction to the building was mixed. Roberta Smith of The New York Times said the building set a new standard for museums and wrote: "The new building’s rippling, sloping facade, rife with subtle curves and bulges, establishes a brilliant alternative to the straight-edged boxes of traditional modernism and the rebellion against them initiated by Frank Gehry, with his computer-inspired acrobatics." On the other hand, the critic of The Guardian of London compared the facade of the building to "a gigantic meringue with a hint of Ikea."
Contemporary architecture	Concert halls	Santiago Calatrava designed the Auditorio de Tenerife he concert hall of Tenerife, the major city of the Canary Islands. with a shell-like wing of reinforced concrete.
Contemporary architecture	Concert halls	The shell touches the ground at only two points.The Walt Disney Concert Hall in Los Angeles (2003) is one of the major works by California architect Frank Gehry The exterior is stainless steel, formed like the sails of sailboats. The interior is in the Vineyard style, with the audience surrounding the stage. Gehry designed the dramatic array of pipes of the organ to complement the exterior style of the building.
Contemporary architecture	Concert halls	The Casa da Musica in Porto, Portugal, by the Dutch architect Rem Koolhaas (2005) is unique among concert halls in having two walls made entirely of glass. Nicolai Ouroussoff, architecture critic from The New York Times, wrote "The building's chiseled concrete form, resting on a carpet of polished stone, suggests a bomb about to explode. He declared that in its originality it was one of the most important concert halls built in the last 100 years". ranking with the Walt Disney Concert Hall, in Los Angeles, and the Berliner Philharmonie.The interior of the Copenhagen Opera House by Henning Larsen (2005) has an oak floor and maple walls to enhance hat acoustics. The royal box of the Queen, usually placed in the back, is next to stage.
Contemporary architecture	Concert halls	The Schermerhorn Symphony Center in Nashville, Tennessee, by David M. Schwarz & Earl Swensson (2006), is an example of Neo-Classical architecture, borrowed literally from Roman and Greek models. It complements another Nashville landmark, a full-scale replica of the Parthenon.
Contemporary architecture	Concert halls	The Philharmonie de Paris by French architect Jean Nouvel opened in 2015. The concert hall is at La Villette, in a park at the edge of Paris devoted to museums, a music school and other cultural institutions, where its unusual shape blends with the late 20th-century modern architecture. The exterior of the building takes the form of glittering irregular cliff cut by horizontal fins which reveal ar amp leading upwards The exterior is clad in thousands of small pieces of aluminum in three different colors, from white to gray to black. A path leads up the ramp to the top of building to a terrace with a dramatic view of the peripheric highway around the city. view of the neighborhood. The hall, like the Disney Hall in Los Angeles, has Vineyard style seating, with the audience surrounding the main stage. The seating can be re-arranged in different styles depending upon the type of music performed. When it opened, the architectural critic of the London Guardian compared it to a space ship that had crash-landed on the outskirts of the city.The Elbphilharmonie concert hall in Hamburg, Germany, by Herzog & de Meuron, which was inaugurated in January 2017, is the tallest inhabited building in the city, with a height of 110 meters (360 feet). The glass concert hall, which has 2100 seats in Vineyard style, is perched atop a former warehouse. One side of the concert hall building contains a hotel, while the structure on the other side above the concert hall contains forty five apartments. The concert hall in the middle is isolated from the sound of the other parts of the building by an "eggshell" of plaster and paper panels and insulation resembling feather pillows.
Contemporary architecture	Skyscrapers	The skyscraper (usually defined as a building over 40 stories high) first appeared in Chicago in the 1890s, and was largely an American style in the mid 20th century, but in the 21st century skyscrapers were found in almost every large city on every continent. A new construction technology, the framed tube structure, was first developed in the United States in 1963 by structural engineer Fazlur Rahman Khan of Skimore, Owings and Merrill, which permitted the construction of super-tall buildings, which needed fewer interior walls, had more window space, and could better resist lateral forces, such as strong winds.The Burj Khalifa in Dubai, United Arab Emirates is the tallest structure in the world, standing at 829.8 m (2,722 ft). Construction of the Burj Khalifa began in 2004, with the exterior completed 5 years later in 2009. The primary structure is reinforced concrete. Burj Khalifa was designed by Adrian Smith, then of Skidmore, Owings & Merrill (SOM). He also was lead architect on the Jin Mao Tower, Pearl River Tower, and Trump International Hotel & Tower.
Contemporary architecture	Skyscrapers	Adrian Smith and his own firm are the architects for the building which, in 2020, meant to replace the Burj-Khalifa as the tallest building in the world. The Jeddah Tower in Jeddah, Saudi Arabia, is planned to be 1,008 meters, or (3,307 ft) tall, which will make it the tallest building in the world, and the first building to be more than one kilometer in height. Construction began in 2013, and the project is scheduled to be completed in 2020.After the destruction of the twin towers of the World Trade Center in the September 11 terrorist attacks, a new trade center was designed, with the main tower designed by David Childs of SOM. One World Trade Center, opened in 2015, is 1,776 feet (541 m) tall, making it the tallest building in the western hemisphere.
Contemporary architecture	Skyscrapers	In London, one of the most notable contemporary landmarks is 30 St Mary Axe, popularly known as "The Gherkin", designed by Norman Foster (2004). It replaced the London Millennium Tower – a much taller project that Foster earlier had proposed for the same site, which would have been the tallest building in Europe, but was so tall that it interfered with the flight pattern for Heathrow Airport. The steel framework of the Gherkin is integrated into the glass facade.The tallest building in Moscow is the Federation Tower, designed by the Russian architect Sergei Tchoban with Peter Schweger. Completed in 2017, with a height 373 meters, it surpassed Mercury City Tower, another skyscraper in Moscow, when it was built as the tallest building in Europe.
Contemporary architecture	Skyscrapers	The tallest building in China as of 2015 is the Shanghai Tower by the U.S. architectural and design firm of Gensler. It is 632-meter (2,073-foot) tall, with 127 floors, making it in 2016 the second-tallest building in the world. It also features the fastest elevators, which reach a speed of 20.5 meters per second (67 feet per second; 74 kilometers per hour) .Most skyscrapers are designed to express modernity; the most notable exception is the Abraj Al Bait, a complex of seven skyscraper hotels build by the government of Saudi Arabia to house pilgrims coming the holy shrine of Mecca. The centerpiece of the group is the Makkah Palace Clock Tower Hotel, with a gothic revival tower; it was the fourth-tallest building in the world in 2016, 581.1 meters (1,906 feet) high.
Contemporary architecture	Residential buildings	A tendency in contemporary residential architecture, particularly in the rebuilding of older neighborhoods in large cities, is the luxury condominium tower, with very expensive apartments for sale designed by "starchitects", that is, internationally famous architects. These buildings frequently have little relationship with the architecture of their neighborhood, but stand like signature works of their architects.
Contemporary architecture	Residential buildings	Daniel Libeskind (born 1946), was born in Poland and studied, taught and practiced architecture in the United States. In 2016 he was professor of architecture at UCLA in Los Angeles, He is known as much for his writings as his architecture; he was a founder of the movement called Deconstructivism. Best known for his museums, he also constructed a notable complex of residential apartment buildings in Singapore (2011) and The Ascent at Roebling's Bridge a 22-story apartment building in Covington, Kentucky (2008). The name of the latter is taken from the Roebling Suspension Bridge nearby on the Ohio River, but the structure of the building of luxury condominiums is extremely contemporary, sloping upward like the bridge cables to a peak, with a sharp edge and leaning slightly outward as the building rises.
Contemporary architecture	Residential buildings	One cheerful feature of contemporary residential architecture is color; Bernard Tschumi uses colored ceramic tiles on facades as well as unusual forms to make his buildings stand out. One example is the Blue Condominium in New York City (2007).Another contemporary tendency is the conversion of industrial buildings into mixed residential communities. An example is the Gasometer in Vienna, a group of four massive brick gas production towers constructed at the end of the 19th century. They have been transformed into a mixed residential, office and commercial complex, completed between 1999 and 2001. Some residences are located inside the towers, and others are in new buildings attached to them. The upper floors are devoted to housing units the middle floors to offices, and the ground floors to entertainment and shopping malls. with sky bridges connecting the shopping mall levels. Each tower was built by a prominent architect the participants were Jean Nouvel, Coop Himmelblau, Manfred Wehldorn and Wilhelm Holzbauer. The historic exterior walls of the towers were preserved.The Isbjerget, Danish for "iceberg", in Aarhus, Denmark (2013), is a group of four buildings with 210 apartments, both rented and owned, for residents with a range of incomes, located on the waterfront of a former industrial port in Denmark. The complex was designed by the Danish firms CEBRA and JDS Architects, French architect Louis Paillard and the Dutch firm SeARCH, and was financed by the Danish pension fund. The buildings are designed so that all the units, even those in the back, have a view of sea. The design and color of the buildings is inspired by icebergs. The buildings are clad in white terrazzo and have balconies made of blue glass.
Contemporary architecture	Religious architecture	Surprisingly few contemporary churches were built between 2000 and 2017. Church architects, with a few exceptions, rarely showed the same freedom of expression as architects of museums, concert halls and other large buildings. The new cathedral for the City of Los Angeles California, was designed in a postmodern style by the Spanish architect Rafael Moneo. The previous cathedral had been serious damaged by an earthquake in 1995; the new building was specially designed to resist similar shocks.
Contemporary architecture	Religious architecture	The Northern Lights Cathedral, by the Denmark-based international firm of Schmidt, Hammer and Lassen, is located in Alta, Norway, one of northernmost cities in the world. Their other important works include the National Library of Denmark in Copenhagen.The Vrindavan Chandrodaya Mandir is a Hindu Temple in Vrindivan, in Uttar Pradesh state in India, which was under construction at the end of 2016. The architects are InGenious Studio Pvt. Ltd. of Gurgaon and Quintessence Design Studio of Noida, in India. The entrance is in the traditional Nagara style of Indian architecture, while the tower is contemporary, with a glass facade up to the 70th floor. It is scheduled for completion in 2019. When completed, at 700 feet (210 meters) or 70 floors) it will be the tallest religious structure in the world.One of the most unusual contemporary churches is St. Jude's Anglican Cathedral in Iqaluit, the capital of Nunavut, the northernmost and least populous region of Canada. The church is built in the shape of an igloo, and serves the Inuktitut-speaking population of the region.
Contemporary architecture	Religious architecture	Another unusual contemporary church is the Cardboard Cathedral in Christchurch, New Zealand designed by Japanese architect Shigeru Ban. It replaced the city's main cathedral, damaged by the 2011 Christchurch earthquake. The cathedral, which seats seven hundred persons, rises 21 metres (69 ft) above the altar. Materials used include 60-centimetre (24 in)-diameter cardboard tubes, timber and steel. The roof is of polycarbon, with eight shipping containers forming the walls. "coated with waterproof polyurethane and flame retardants" with two-inch gaps between them so that light can filter inside.
Contemporary architecture	Stadiums	The Swiss architects Jacques Herzog and Pierre de Meuron designed the Allianz Arena in Munich, Germany, completed in 2005. It seats 75,000 spectators. The structure is wrapped in 2,874 ETFE-foil air panels that are kept inflated with dry air; each panel can be independently illuminated red, white, or blue. When illuminated, the stadium is visible from the Austrian Alps, fifty miles (80 kilometers) away.Among the most prestigious projects and best-known projects in contemporary architecture are the stadiums for the Olympic Games, whose architects are chosen by highly publicized international competitions. The Beijing National Stadium, built for the 2008 Games and popularly known as the Bird's Nest because of its intricate exterior framework, was designed by the Swiss firm of Herzog & de Meuron, with Chinese architect Li Xinggang. It was designed to seat 91,000 spectators, and when constructed had a retractable roof, since removed. Like many contemporary buildings, it is actually two structures; a concrete bowl in which the spectators sit, surrounded at distance of fifty feet by a glass and steel framework. The exterior "Bird's nest" design was inspired by the pattern of Chinese ceramics. The stadium when completed was the largest enclosed space in the world, and was also the largest steel structure, with 26 kilometers of unwrapped steel.The National Stadium in Kaohsiung, Taiwan by Japanese architect Toyo Ito (2009), is the form of a dragon. Its other distinctive feature is the array of solar panels that cover almost all of the exterior, providing most of the energy needed by the complex.
Contemporary architecture	Government buildings	Government buildings, once almost universally serious and sober looking, usually in variations of the school of neoclassical architecture, began to appear in more sculptural and even whimsical forms. One of the most dramatic examples was the London City Hall by Norman Foster (2002), the headquarters of the Greater London Authority. The unusual egg-like building design was intended to reduce the amount of exposed wall and to save energy, though the results have not entirely met expectations. One unusual feature is a helical stairway that spirals from the lobby up to the top of the building.
Contemporary architecture	Government buildings	Some new government buildings, such as the Parliament House, Valletta, Malta by Renzo Piano (2015) created controversy because of the contrast between their style and the historic architecture around them.Most new government buildings attempt to express solidity and seriousness; an exception is the Port Authority (Havenhuis) in Antwerp, Belgium by Zaha Hadid (2016), where a ship-like structure of glass and steel on a white concrete perch seems to have landed atop the old port building constructed in 1922. The faceted glass structure also resembles a diamond, a symbol of Antwerp's role as the major market of diamonds in Europe. It was one of the last works of Hadid, who died in 2016.
Contemporary architecture	University buildings	The Dr Chau Chak Wing Building is a Business School building of the University of Technology Sydney in Sydney, New South Wales, Australia, designed by Frank Gehry and completed in 2015. It is the first building in Australia designed by Gehry. The building's façade, made of 320,000 custom designed bricks, was described by one critic as the "squashed brown paper bag". Frank Gehry responded, "Maybe it's a brown paper bag, but it's flexible on the inside, there's a lot of room for changes or movement."The Siamese Twins Towers" at the Pontifical Catholic University of Chile in Santiago, Chile are by the Chilean architect Alejandro Aravena (born 1967), completed in 2013. Aravena was the winner of the 2016 Pritzker Architecture Prize.
Contemporary architecture	Libraries	The Bibliotheca Alexandrina in Alexandria, Egypt, by the Norwegian firm of Snøhetta (2002), attempts to recreate, in modern form, the famous Alexandria Library of antiquity. The building, by the edge of the Mediterranean, has shelf space for eight million books, and a main reading room covering 20,000 square metres (220,000 sq ft) on eleven cascading levels. plus galleries for expositions and a planetarium. The main reading room is covered by a 32-meter-high glass-panelled roof, tilted out toward the sea like a sundial, and measuring some 160 m in diameter. The walls are of gray Aswan granite, carved with characters from 120 different human scripts.
Contemporary architecture	Libraries	The Seattle Central Library by Dutch architect Rem Koolhaas (2006) features a glass and steel wrapping around a stack of platforms. One unusual feature is a ramp with continuous bookshelves spiraling upward four floors.
Contemporary architecture	Malls and retail stores	The shopping malls are the elephants of commercial architecture, massive structures which combine retail stores, food outlets, and entertainment under a single roof. The largest in area (though not in retail space, since much of the mall is devoted to entertainment and public space) and perhaps most extravagant is the Dubai Mall in the United Arab Emirates, designed by DP Architects of Singapore and opened in (2008), which features, in addition to shops and restaurants, a gigantic walk-through aquarium and underwater zoo, plus a huge ice skating rink, and, just outside, the highest fountain and tallest building in the world.
Contemporary architecture	Malls and retail stores	In competition with shopping malls are downtown department stores and shops of individual designer brands. These buildings are traditionally designed to attract attention and to express the modernity of the products they sell. A notable example is the Selfridge's Department Store in Birmingham, England, a department store designed by the firm of Future Systems, founded in 1979 by Jan Kaplický (1937–2009). The department store exterior is composed of undulating concrete in convex and concave forms, entirely covered with gleaming blue and white ceramic tiles.Designer brand shops try make their logo visible and to set themselves apart from department stores. One notable example is the Louis Vuitton store in the Ginza district of Tokyo, with a new facade designed by Japanese studio of Jun Aoki and Associates with a patterned and perforated shell based on the brand's logo.
Contemporary architecture	Airports, railway stations and transport hubs	Beijing Capital International Airport has been one of the fast-growing airports in the world. The new Terminal Three was designed by Norman Foster to handle the increased number of passengers coming for the 2008 Beijing Olympics. The terminal is the second largest in the world, after the Dulles Airport terminal near Washington, DC, and in 2008 was the sixth largest building in the world. The flat-roofed building looks like part of the runway from above.
Contemporary architecture	Airports, railway stations and transport hubs	The World Trade Center Transportation Hub is a station constructed beneath fountain and plaza honoring the victims of the 2001 terrorist attacks in 2001 in New York City, It was designed by Spanish architect Santiago Calatrava and opened in 2016. The above-ground structure, called the Oculus, has been compared to a bird about to take flight, and leads passengers down to the train station below the plaza. Michael Kimmelman, the architecture critic of The New York Times praised the soaring upward view inside the Oculus, but condemned what he called the buildings cost (the most expensive railroad station ever built) "scale, monotony of materials and color, preening formalism and disregard for the gritty urban fabric."
Contemporary architecture	Bridges	Several of the most prominent contemporary architects, including Norman Foster, Santiago Calatrava, Zaha Hadid, have turned their attention to designing bridges. One of the most remarkable examples of contemporary architecture and engineering is the Millau Viaduct in southern France, designed by architect Norman Foster and structural engineer Michel Virlogeux. The Millau Viaduct crosses the valley of the River Tarn and is part of the A75-A71 autoroute axis from Paris to Béziers and Montpellier. It was formally inaugurated on 14 December 2004. It is the tallest bridge in the world with one mast's summit at 343.0 metres (1,125 ft) above the base of the structure.The British-Iraqi architect Zaha Hadid constructed the Bridge Pavilion in Zaragoza. Spain for an international exposition there in 2008. The bridge, which also served as an exposition hall, is constructed of concrete reinforced with an external layer of fiberglass in different shades of gray. Since the event closed, the bridge has been used to host expositions and shows.
Contemporary architecture	Bridges	Some smaller new bridges also offer simple but very innovative designs. The Gateshead Millennium Bridge in Newcastle upon Tyne, England, (2004) designed by Michel Virlogeux, to enable pedestrians and cyclists to cross the Tyne River, tilts to one side to permit boats to pass beneath.
Contemporary architecture	Eco-architecture	A growing tendency in the 21st century is eco-architecture, also termed sustainable architecture; buildings with features which conserve heat and energy, and sometimes produce their own energy through solar cells and windmills, and use solar heat to generate solar hot water. They also may be built with their own wastewater treatment and sometimes rainwater harvesting Some buildings integrate gardens green walls and green roofs into their structures. Other features of eco-architecture include the use of wood and recycled materials. There are several green building certification programs, the best-known of which is the Leadership in Energy and Environmental Design, or LEED rating, which measure the environmental impact of buildings.
Contemporary architecture	Eco-architecture	Many urban skyscrapers such as 30 Saint Mary Axe in London use a double skin of glass to conserve energy. The double skin and curved shape of the building creates differences in air pressure which help keep the building cooler in summer and warmer in winter, reducing the need for air conditioning.BedZED, designed by British architect Bill Dunster, is an entire community of eighty-two homes in Hackbridge, near London, built according to eco-architecture principles. Houses face south to take advantage of sunlight and have triple-glazed windows for insulation, a significant portion of the energy comes from solar panels, rainwater is collected and reused, and automobiles are discouraged. BedZED successfully reduced electricity usage by 45 percent and hot water usage by 81 percent of the borough average in 2010, though a successful system for producing heat by burning wood chips proved elusive and difficult.The CaixaForum Madrid is a museum and cultural center in Paseo del Prado 36, Madrid, by the Swiss architects Herzog & de Meuron, built between 2001 and 2007, is an example of both green architecture and recycling. The main structure is an abandoned brick electric power station, with new floors constructed on top. The new floors are encased in oxidized cast iron, which has a rusty red color as the brick of the old power station below it. The building next to it features a green wall designed by French botanist Patrick Blanc. The red of the top floors contrast with the plants on the wall, while the green wall harmonizes with the botanical garden next door to the cultural center.Unusual materials are sometimes recycled for use in eco-architecture; they include denim from old blue jeans for insulation, and panels made from paper flakes, baked earth, flax, sisal, or coconut, and particularly fast-growing bamboo. Lumber and stone from demolished buildings are often reclaimed and reused for flooring, while hardware, windows and other details from older buildings are reused.
Contemporary architecture	Bibliography and Further reading	Bony, Anne (2012). L'Architecture Moderne (in French). Larousse. ISBN 978-2-03-587641-6. Poisson, Michel (2009). 1000 Immeubles et monuments de Paris (in French). Parigramme. ISBN 978-2-84096-539-8. Taschen, Aurelia and Balthazar (2016). L'Architecture Moderne de A à Z (in French). Bibliotheca Universalis. ISBN 978-3-8365-5630-9. Prina, Francesca; Demaratini, Demartini (2006). Petite encyclopédie de l'architecture (in French). Solar. ISBN 2-263-04096-X. Hopkins, Owen (2014). Les styles en architecture- guide visuel (in French). Dunod. ISBN 978-2-10-070689-1. De Bure, Gilles (2015). Architecture contemporaine- le guide (in French). Flammarion. ISBN 978-2-08-134385-6.
Operand	Operand	In mathematics, an operand is the object of a mathematical operation, i.e., it is the object or quantity that is operated on.
Operand	Example	The following arithmetic expression shows an example of operators and operands: 3+6=9 In the above example, '+' is the symbol for the operation called addition. The operand '3' is one of the inputs (quantities) followed by the addition operator, and the operand '6' is the other input necessary for the operation. The result of the operation is 9. (The number '9' is also called the sum of the augend 3 and the addend 6.) An operand, then, is also referred to as "one of the inputs (quantities) for an operation".
Operand	Notation	Expressions as operands Operands may be complex, and may consist of expressions also made up of operators with operands. (3+5)×2 In the above expression '(3 + 5)' is the first operand for the multiplication operator and '2' the second. The operand '(3 + 5)' is an expression in itself, which contains an addition operator, with the operands '3' and '5'. Order of operations Rules of precedence affect which values form operands for which operators: 3+5×2 In the above expression, the multiplication operator has the higher precedence than the addition operator, so the multiplication operator has operands of '5' and '2'. The addition operator has operands of '3' and '5 × 2'. Positioning of operands Depending on the mathematical notation being used the position of an operator in relation to its operand(s) may vary. In everyday usage infix notation is the most common, however other notations also exist, such as the prefix and postfix notations. These alternate notations are most common within computer science.
Operand	Notation	Below is a comparison of three different notations — all represent an addition of the numbers '1' and '2' 1+2 (infix notation) +12 (prefix notation) 12+ (postfix notation) Infix and the order of operation In a mathematical expression, the order of operation is carried out from left to right. Start with the leftmost value and seek the first operation to be carried out in accordance with the order specified above (i.e., start with parentheses and end with the addition/subtraction group). For example, in the expression 4×22−(2+22) ,the first operation to be acted upon is any and all expressions found inside a parenthesis. So beginning at the left and moving to the right, find the first (and in this case, the only) parenthesis, that is, (2 + 22). Within the parenthesis itself is found the expression 22. The reader is required to find the value of 22 before going any further. The value of 22 is 4. Having found this value, the remaining expression looks like this: 4×22−(2+4) The next step is to calculate the value of expression inside the parenthesis itself, that is, (2 + 4) = 6. Our expression now looks like this: 4×22−6 Having calculated the parenthetical part of the expression, we start over again beginning with the left most value and move right. The next order of operation (according to the rules) is exponents. Start at the left most value, that is, 4, and scan your eyes to the right and search for the first exponent you come across. The first (and only) expression we come across that is expressed with an exponent is 22. We find the value of 22, which is 4. What we have left is the expression 4×4−6 .The next order of operation is multiplication. 4 × 4 is 16. Now our expression looks like this: 16 −6 The next order of operation according to the rules is division. However, there is no division operator sign (÷) in the expression, 16 − 6. So we move on to the next order of operation, i.e., addition and subtraction, which have the same precedence and are done left to right.
Operand	Notation	16 10 .So the correct value for our original expression, 4 × 22 − (2 + 22), is 10.
Operand	Notation	It is important to carry out the order of operation in accordance with rules set by convention. If the reader evaluates an expression but does not follow the correct order of operation, the reader will come forth with a different value. The different value will be the incorrect value because the order of operation was not followed. The reader will arrive at the correct value for the expression if and only if each operation is carried out in the proper order.
Operand	Notation	Arity The number of operands of an operator is called its arity. Based on arity, operators are chiefly classified as nullary (no operands), unary (1 operand), binary (2 operands), ternary (3 operands). Higher arities are less frequently denominated through a specific terms, all the more when function composition or currying can be used to avoid them. Other terms include:
Operand	Computer science	In computer programming languages, the definitions of operator and operand are almost the same as in mathematics. In computing, an operand is the part of a computer instruction which specifies what data is to be manipulated or operated on, while at the same time representing the data itself. A computer instruction describes an operation such as add or multiply X, while the operand (or operands, as there can be more than one) specify on which X to operate as well as the value of X.
Operand	Computer science	Additionally, in assembly language, an operand is a value (an argument) on which the instruction, named by mnemonic, operates. The operand may be a processor register, a memory address, a literal constant, or a label. A simple example (in the x86 architecture) is where the value in register operand AX is to be moved (MOV) into register DS. Depending on the instruction, there may be zero, one, two, or more operands.
Pauson–Khand reaction	Pauson–Khand reaction	The Pauson–Khand (PK) reaction is a chemical reaction, described as a [2+2+1] cycloaddition. In it, an alkyne, an alkene and carbon monoxide combine into a α,β-cyclopentenone in the presence of a metal-carbonyl catalyst.Ihsan Ullah Khand (1935-1980) discovered the reaction around 1970, while working as a postdoctoral associate with Peter Ludwig Pauson (1925–2013) at the University of Strathclyde in Glasgow. Pauson and Khand's initial findings were intermolecular in nature, but the reaction has poor selectivity. Most modern applications instead apply the reaction for intramolecular ends.The traditional catalyst is stoichiometric amounts of dicobalt octacarbonyl, stabilized by a carbon monoxide atmosphere. Catalytic metal quantities, enhanced reactivity and yield, or stereoinduction are all possible with the right chiral auxiliaries, choice of transition metal (Ti, Mo, W, Fe, Co, Ni, Ru, Rh, Ir and Pd), and additives.
Pauson–Khand reaction	Mechanism	While the mechanism has not yet been fully elucidated, Magnus' 1985 explanation is widely accepted for both mono- and dinuclear catalysts, and was corroborated by computational studies published by Nakamura and Yamanaka in 2001. The reaction starts with dicobalt hexacarbonyl acetylene complex. Binding of an alkene gives a metallacyclopentene complex. CO then migratorily inserts into an M-C bond. Reductive elimination delivers the cyclopentenone. Typically, the dissociation of carbon monoxide from the organometallic complex is rate limiting.
Pauson–Khand reaction	Selectivity	The reaction works with both terminal and internal alkynes, although internal alkynes tend to give lower yields. The order of reactivity for the alkene is(strained cyclic) > (terminal) > (disubstituted) > (trisubstituted). Tetrasubstituted alkenes and alkenes with strongly electron-withdrawing groups are unsuitable. With unsymmetrical alkenes or alkynes, the reaction is rarely regioselective, although some patterns can be observed. For mono-substituted alkenes, alkyne substituents typically direct: larger groups prefer the C2 position, and electron-withdrawing groups prefer the C3 position. But the alkene itself struggles to discriminate between the C4 and C5 position, unless the C2 position is sterically congested or the alkene has a chelating heteroatom. The reaction's poor selectivity is ameliorated in intramolecular reactions. For this reason, the intramolecular Pauson-Khand is common in total synthesis, particularly the formation of 5,5- and 6,5-membered fused bicycles. Generally, the reaction is highly syn-selective about the bridgehead hydrogen and substituents on the cyclopentane. Appropriate chiral ligands or auxiliaries can make the reaction enantioselective (see § Amine N-oxides). BINAP is commonly employed.
Pauson–Khand reaction	Additives	Typical Pauson-Khand conditions are elevated temperatures and pressures in aromatic hydrocarbon (benzene, toluene) or ethereal (tetrahydrofuran, 1,2-dichloroethane) solvents. These harsh conditions may be attenuated with the addition of various additives. Absorbent surfaces Adsorbing the metallic complex onto silica or alumina can enhance the rate of decarbonylative ligand exchange as exhibited in the image below. This is because the donor posits itself on a solid surface (i.e. silica). Additionally using a solid support restricts conformational movement (rotamer effect). Lewis bases Traditional catalytic aids such as phosphine ligands make the cobalt complex too stable, but bulky phosphite ligands are operable. Lewis basic additives, such as n-BuSMe, are also believed to accelerate the decarbonylative ligand exchange process. However, an alternative view holds that the additives make olefin insertion irreversible instead. Sulfur compounds are typically hard to handle and smelly, but n-dodecyl methyl sulfide and tetramethylthiourea do not suffer from those problems and can improve reaction performance.
Pauson–Khand reaction	Additives	Amine N-oxides The two most common amine N-oxides are N-methylmorpholine N-oxide (NMO) and trimethylamine N-oxide (TMANO). It is believed that these additives remove carbon monoxide ligands via nucleophilic attack of the N-oxide onto the CO carbonyl, oxidizing the CO into CO2, and generating an unsaturated organometallic complex. This renders the first step of the mechanism irreversible, and allows for more mild conditions. Hydrates of the aforementioned amine N-oxides have similar effect.
Pauson–Khand reaction	Additives	N-oxide additives can also improve enantio- and diastereoselectivity, although the mechanism thereby is not clear.
Pauson–Khand reaction	Alternative catalysts	The original Pauson-Khand catalyst is a low-oxidation-state cobalt complex unstable in air. Multinuclear cobalt catalysts like (Co)4(CO)12 and Co3(CO)9(μ3-CH) suffer from the same flaw, although Takayama et al detail a reaction catalyzed by dicobalt octacarbonyl. One stabilization method is to generate the catalyst in situ. Chung reports that Co(acac)2 can serve as a precatalyst, activated by sodium borohydride. Other metals Wilkinson's rhodium-based catalyst requires a silver triflate co-catalyst to effect the Pauson-Khand reaction: Molybdenum hexacarbonyl is a carbon monoxide donor in PK-type reactions between allenes and alkynes with dimethyl sulfoxide in toluene. Titanium, nickel, and zirconium complexes admit the reaction. Other metals can also be employed in these transformations.
Pauson–Khand reaction	Substrate tolerance	In general allenes, support the Pauson-Khand reaction; regioselectivity is determined by the choice of metal catalyst. Density functional investigations show the variation arises from different transition state metal geometries. Heteroatoms are also acceptable: Mukai et al's total synthesis of physostigmine applied the Pauson-Khand reaction to a carbodiimide. Cyclobutadiene also lends itself to a [2+2+1] cycloaddition, although this reactant is too active to store in bulk. Instead, ceric ammonium nitrate cyclobutadiene is generated in situ from decomplexation of stable cyclobutadiene iron tricarbonyl with (CAN). An example of a newer version is the use of the chlorodicarbonylrhodium(I) dimer, [(CO)2RhCl]2, in the synthesis of (+)-phorbol by Phil Baran. In addition to using a rhodium catalyst, this synthesis features an intramolecular cyclization that results in the normal 5-membered α,β-cyclopentenone as well as 7-membered ring.
Pauson–Khand reaction	Substrate tolerance	Carbon monoxide generation in situ Recently, several groups have published work avoiding the use of toxic carbon monoxide, and instead generate the cyclopentenone carbonyl motif from aldehydes, carboxylic acids, and formates. These examples typically employ rhodium as the organometallic transition metal, as it is commonly used in decarbonylation reactions. The decarbonylation and PK reaction occur in the same reaction vessel.

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