title: Airship content: due to an anomaly, the company decided to abort the mission. The airship made a controlled descent in an unpopulated area of southwest Pennsylvania. On 31 January 2006 Lockheed Martin made the first flight of their secretly built hybrid airship designated the P-791. The design is very similar to the SkyCat, unsuccessfully promoted for many years by the British company Advanced Technologies Group (ATG). Although Lockheed Martin is developing a design for the DARPA WALRUS HULA project, it claimed that the P-791 is unrelated to WALRUS. Nonetheless, the design represents an approach that may well be applicable to WALRUS. Some


title: Airship content: believe that Lockheed Martin had used the secret P-791 program as a way to get a head start on the other WALRUS competitor, US Aeros Airships. In the 1990s, the successor of the original Zeppelin company in Friedrichshafen, the "Zeppelin Luftschifftechnik GmbH", reengaged in airship construction. The first experimental craft (later christened "Friedrichshafen") of the type "Zeppelin NT" flew in September 1997. Though larger than common blimps, the "Neue Technologie" (New Technology) zeppelins are much smaller than their giant ancestors and not actually Zeppelin-types in the classical sense. They are sophisticated semirigids. Apart from the greater payload, their main advantages


title: Airship content: compared to blimps are higher speed and excellent maneuverability. Meanwhile, several "Zeppelin NT" have been produced and operated profitably in joyrides, research flights and similar applications. In June 2004, a Zeppelin NT was sold for the first time to a Japanese company, Nippon Airship Corporation, for tourism and advertising mainly around Tokyo. It was also given a role at the 2005 Expo in Aichi. The aircraft began a flight from Friedrichshafen to Japan, stopping at Geneva, Paris, Rotterdam, Munich, Berlin, Stockholm and other European cities to carry passengers on short legs of the flight. Russian authorities denied overflight permission, however,


title: Airship content: so the airship had to be dismantled and shipped to Japan rather than following the historic "Graf Zeppelin" flight from Germany to Japan. In 2008, Airship Ventures Inc. began operations from Moffett Federal Airfield near Mountain View, California and until November 2012 offered tours of the San Francisco Bay Area for up to 12 passengers. In November 2005, De Beers, a diamond mining company, launched an airship exploration program over the remote Kalahari desert. A Zeppelin NT, equipped with a Bell Geospace gravity gradiometer, was used to find potential diamond mines by scanning the local geography for low-density rock formations,


title: Airship content: known as kimberlite pipes. On 21 September 2007, the airship was severely damaged by a whirlwind while in Botswana. One crew member, who was on watch aboard the moored craft, was slightly injured but released after overnight observation in hospital. Several companies, such as Cameron Balloons in Bristol, United Kingdom, build hot-air airships. These combine the structures of both hot-air balloons and small airships. The envelope is the normal cigar shape, complete with tail fins, but is inflated with hot air instead of helium to provide the lifting force. A small gondola, carrying the pilot and passengers, a small engine,


title: Airship content: and the burners to provide the hot air are suspended below the envelope, beneath an opening through which the burners protrude. Hot-air airships typically cost less to buy and maintain than modern helium-based blimps, and can be quickly deflated after flights. This makes them easy to carry in trailers or trucks and inexpensive to store. They are usually very slow moving, with a typical top speed of 25–30 km/h (15–20 mph, 6.7–8.9 m/s). They are mainly used for advertising, but at least one has been used in rainforests for wildlife observation, as they can be easily transported to remote areas.


title: Airship content: Remote-controlled (RC) airships, a type of unmanned aerial system (UAS), are sometimes used for commercial purposes such as advertising and aerial video and photography as well as recreational purposes. They are particularly common as an advertising mechanism at indoor stadiums. While RC airships are sometimes flown outdoors, doing so for commercial purposes is illegal in the US. Commercial use of an unmanned airship must be certified under part 121. Today, with large, fast, and more cost-efficient fixed-wing aircraft and helicopters, it is unknown whether huge airships can operate profitably in regular passenger transport though, as energy costs rise, attention is


title: Airship content: once again returning to these lighter-than-air vessels as a possible alternative. At the very least, the idea of comparatively slow, "majestic" cruising at relatively low altitudes and in comfortable atmosphere certainly has retained some appeal. There have been some niches for airships in and after World War II, such as long-duration observations, antisubmarine patrol, platforms for TV camera crews, and advertising; these, however, generally require only small and flexible craft, and have thus generally been better fitted for cheaper (non-passenger) blimps. It has periodically been suggested that airships could be employed for cargo transport, especially delivering extremely heavy loads to


title: Airship content: areas with poor infrastructure over great distances. This has also been called roadless trucking. Also, airships could be used for heavy lifting over short distances (e.g. on construction sites); this is described as heavy-lift, short-haul. In both cases, the airships are heavy haulers. One recent enterprise of this sort was the "Cargolifter" project, in which a hybrid (thus not entirely Zeppelin-type) airship even larger than "Hindenburg" was projected. Around 2000, CargoLifter AG built the world's largest self-supporting hall, measuring long, wide and high about south of Berlin. In May 2002, the project was stopped for financial reasons; the company had


title: Airship content: to file bankruptcy. The enormous CargoLifter hangar was later converted to house the Tropical Islands Resort. Although no rigid airships are currently used for heavy lifting, hybrid airships are being developed for such purposes. AEREON 26, tested in 1971, was described in John McPhee's "The Deltoid Pumpkin Seed". An impediment to the large-scale development of airships as heavy haulers has been figuring out how they can be used in a cost-efficient way. In order to have a significant economic advantage over ocean transport, cargo airships must be able to deliver their payload faster than ocean carriers but more cheaply than


title: Airship content: airplanes. William Crowder, a fellow at the Logistics Management Institute, has calculated that cargo airships are only economical when they can transport 500 to 1,000 tons, approximately the same as a super-jumbo aircraft. The large initial investment required to build such a large airship has been a hindrance to production, especially given the risk inherent in a new technology. The chief commercial officer of the company hoping to sell the LMH-1, a cargo airship currently being developed by Lockheed Martin, believes that airships can be economical in hard-to-reach locations such as mining operations in northern Canada that currently require ice


title: Airship content: roads. A metal-clad airship has a very thin metal envelope, rather than the usual fabric. The shell may be either internally braced or monocoque as in the ZMC-2, which flew many times in the 1920s, the only example ever to do so. The shell may be gas-tight as in a non-rigid blimp, or the design may employ internal gas bags as in a rigid airship. Compared to a fabric envelope the metal cladding is expected to be more durable. A hybrid airship is a general term for an aircraft that combines characteristics of heavier-than-air (aeroplane or helicopter) and lighter-than-air technology.


title: Airship content: Examples include helicopter/airship hybrids intended for heavy lift applications and dynamic lift airships intended for long-range cruising. It should be noted that most airships, when fully loaded with cargo and fuel, are usually ballasted to be heavier than air, and thus must use their propulsion system and shape to create aerodynamic lift, necessary to stay aloft. All airships can be operated to be slightly heavier than air at periods during flight (descent). Accordingly, the term "hybrid airship" refers to craft that obtain a significant portion of their lift from aerodynamic lift or other kinetic means. For example, the Aeroscraft is


title: Airship content: a buoyancy assisted air vehicle that generates lift through a combination of aerodynamics, thrust vectoring and gas buoyancy generation and management, and for much of the time will fly heavier than air. Aeroscraft is Worldwide Aeros Corporation's continuation of DARPA's now cancelled Walrus HULA (Hybrid Ultra Large Aircraft) project. The Patroller P3 hybrid airship developed by Advanced Hybrid Aircraft Ltd, BC, Canada, is a relatively small (85,000 feet3 = 2,400 m3) buoyant craft, manned by the crew of 5 and with the endurance of up to 72 hours. The flight-tests with the 40% RC scale model proved that such a


title: Airship content: craft can be launched and landed without a large team of strong ground-handlers. Design features a special “winglet” for aerodynamic lift control. Airships have been proposed as a potential cheap alternative to surface rocket launches for achieving Earth orbit. JP Aerospace have proposed the Airship to Orbit project, which intends to float a multi-stage airship up to mesospheric altitudes of 55 km (180,000 ft) and then use ion propulsion to accelerate to orbital speed. At these heights, air resistance would not be a significant problem for achieving such speeds. The company has not yet built any of the three stages.


title: Airship content: NASA have proposed the High Altitude Venus Operational Concept, which comprises a series of five missions including manned missions to the atmosphere of Venus in airships. Pressures on the surface of the planet are too high for human habitation, but at a specific altitude the pressure is equal to that found on Earth and this makes Venus a potential target for human colonization. The advantage of airships over aeroplanes is that static lift sufficient for flight is generated by the lifting gas and requires no engine power. This was an immense advantage before the middle of World War I and


title: Airship content: remained an advantage for long-distance or long-duration operations until World War II. Modern concepts for high-altitude airships include photovoltaic cells to reduce the need to land to refuel, thus they can remain in the air until consumables expire. The disadvantages are that an airship has a very large reference area and comparatively large drag coefficient, thus a larger drag force compared to that of aeroplanes and even helicopters. Given the large frontal area and wetted surface of an airship, a practical limit is reached around . Thus airships are used where speed is not critical. The lift capability of an


title: Airship content: airship is equal to the buoyant force minus the weight of the airship. This assumes standard air-temperature and pressure conditions. Corrections are usually made for water vapor and impurity of lifting gas, as well as percentage of inflation of the gas cells at liftoff. Based on specific lift (lifting force per unit volume of gas), the greatest static lift is provided by hydrogen (11.15 N/m or 71 lb/1000 cu ft) with helium (10.37 N/m or 66 lb/1000 cu ft) a close second. At 6.13 N/m (39 lb/1000 cu ft), steam is a distant third. Other cheap gases, such as methane,


title: Airship content: carbon monoxide, ammonia and natural gas have even less lifting capacity and are flammable, toxic, corrosive, or all three (neon is even more costly than helium, with less lifting capacity). Operational considerations such as whether the lift gas can be economically vented and produced in flight for control of buoyancy (as with hydrogen) or even produced as a byproduct of propulsion (as with steam) affect the practical choice of lift gas in airship designs. In addition to static lift, an airship can obtain a certain amount of dynamic lift from its engines. Dynamic lift in past airships has been about


title: Airship content: 10% of the static lift. Dynamic lift allows an airship to "take off heavy" from a runway similar to fixed-wing and rotary-wing aircraft. This requires additional weight in engines, fuel, and landing gear, however, negating some of the static lift capacity. The altitude at which an airship can fly largely depends on how much lifting gas it can lose due to expansion before stasis is reached. The ultimate altitude record for a rigid airship was set in 1917 by the L-55 under the command of Hans-Kurt Flemming when he forced the airship to attempting to cross France after the "Silent


title: Airship content: Raid" on London. The L-55 lost lift during the descent to lower altitudes over Germany and crashed due to loss of lift. While such waste of gas was necessary for the survival of airships in the later years of World War I, it was impractical for commercial operations, or operations of helium-filled military airships. The highest flight made by a hydrogen-filled passenger airship was on the "Graf Zeppelin's" around-the-world flight. The practical limit for rigid airships was about , and for pressure airships around . Modern airships use dynamic helium volume. At sea-level altitude, helium takes up only a small


title: Airship content: part of the hull, while the rest is filled with air. As the airship ascends, the helium inflates with reduced outer pressure, and air is pushed out and released from the downward valve. This allows an airship to reach any altitude with balanced inner and outer pressure if the buoyancy is enough. Some civil aerostats could reach without explosion due to overloaded inner pressure. The greatest disadvantage of the airship is size, which is essential to increasing performance. As size increases, the problems of ground handling increase geometrically. As the German Navy changed from the P class of 1915 with


title: Airship content: a volume of over to the larger Q class of 1916, the R class of 1917, and finally the W class of 1918, at almost ground handling problems reduced the number of days the Zeppelins were able to make patrol flights. This availability declined from 34% in 1915, to 24.3% in 1916 and finally 17.5% in 1918. So long as the power-to-weight ratios of aircraft engines remained low and specific fuel consumption high, the airship had an edge for long-range or -duration operations. As those figures changed, the balance shifted rapidly in the aeroplane's favour. By mid-1917, the airship could


title: Airship content: no longer survive in a combat situation where the threat was aeroplanes. By the late 1930s, the airship barely had an advantage over the aeroplane on intercontinental over-water flights, and that advantage had vanished by the end of World War II. This is in face-to-face tactical situations. Currently, a High-altitude airship project is planned to survey hundreds of kilometres as their operation radius, often much farther than the normal engagement range of a military aeroplane. For example, a radar mounted on a vessel platform high has radio horizon at range, while a radar at altitude has radio horizon at range.


title: Airship content: This is significantly important for detecting low-flying cruise missiles or fighter-bombers. The most commonly used lifting gas, helium, is inert and therefore presents no fire risk. A series of vulnerability tests were done by the UK Defence Evaluation and Research Agency DERA on a Skyship 600. Since the internal gas pressure was maintained at only 1–2% above the surrounding air pressure, the vehicle proved highly tolerant to physical damage or to attack by small-arms fire or missiles. Several hundred high-velocity bullets were fired through the hull, and even two hours later the vehicle would have been able to return to


title: Airship content: base. Ordnance passed through the envelope without causing critical helium loss. In all instances of light armament fire evaluated under both test and live conditions, the airship was able to complete its mission and return to base. Airship An airship or dirigible balloon is a type of aerostat or lighter-than-air aircraft that can navigate through the air under its own power. Aerostats gain their lift from large gasbags filled with a lifting gas that is less dense than the surrounding air. In early dirigibles, the lifting gas used was hydrogen, due to its high lifting capacity and ready availability. Helium


title: "Babylonian law" content: Babylonian law Babylonian law is a subset of cuneiform law that has received particular study, owing to the singular extent of the associated archaeological material that has been found for it. So-called "contracts" exist in the thousands, including a great variety of deeds, conveyances, bonds, receipts, accounts, and most important of all, actual legal decisions given by the judges in the law courts. Historical inscriptions, royal charters and rescripts, dispatches, private letters and the general literature afford welcome supplementary information. Even grammatical and lexicographical texts contain many extracts or short sentences bearing on law and custom. The so-called "Sumerian Family


title: "Peerages in the United Kingdom" content: peers have been elected, though sitting members retained their seats for life. Apart from hereditary peerages, there exists peerages that may be held for life and whose title cannot be passed onto someone else by inheritance. The Appellate Jurisdiction Act 1876 and the Life Peerages Act 1958 authorise the regular creation of life peerages, with the right to sit in the House of Lords. Life peers created under both acts are of baronial rank and are always created under letters patent. Since the loss of the right of hereditary peers to sit in the House of Lords as a result


title: "Medicare (United States)" content: designed to measure changes in costs of physician's time and operating expenses, adjusted for changes in physician productivity. From 1984 to 1991, the yearly change in fees was determined by legislation. This was done because physician fees were rising faster than projected. The Omnibus Budget Reconciliation Act of 1989 made several changes to physician payments under Medicare. Firstly, it introduced the Medicare Fee Schedule, which took effect in 1992. Secondly, it limited the amount Medicare non-providers could balance bill Medicare beneficiaries. Thirdly, it introduced the Medicare Volume Performance Standards (MVPS) as a way to control costs. On January 1, 1992,


title: "Medicare (Canada)" content: tax revenue to Alberta (e.g. through fuel, tobacco and alcohol taxes) while their health insurance costs are borne by their home province in Atlantic Canada. Another considerable inter-provincial imbalance is a person who is insured by Quebec and obtains healthcare in another province or territory. Quebec does not have any physician payment agreements with any other provinces or territories of Canada. As a result, someone that sees a physician outside Quebec, even in another part of Canada, must either pay the cost themselves and submit a request to the Régie de l'Assurance Maladie du Québec (RAMQ Medicare) for reimbursement (even


title: "Airborne forces" content: 1943. The American paratroopers were from the 82nd Airborne Division, mainly Colonel James Gavin's 505th Parachute Regimental Combat Team (consisting of the 3rd Battalion of the 504th PIR, Company 'B' of the 307th Airborne Engineer Battalion and the 456th Parachute Field Artillery Battalion, with other supporting units), making their first combat jump. Strong winds encountered en route blew the dropping aircraft off course and scattered them widely. The result was that around half the paratroopers failed to make it to their rallying points. The British airborne troops from the 1st Airborne Division were glider infantry of the 1st Airlanding Brigade,


title: "Inversions (novel)" content: supposedly written by Perrund herself, instead has DeWar telling the waiting guards and staff that UrLeyn is fine but sleeping, this and other distractions providing enough time for him and the former concubine to flee Tassasen before the Protector's body is discovered. The two elude capture and arrive in the Half-Hidden Kingdoms, eventually marry, have several children, and die many years later in an avalanche in the mountains. Finally, Oelph ends his epilogue by revealing that he expects his wife, whom he loves dearly, to return soon, quite possibly with his grandchildren accompanying her. The initial hardback printing of the


title: Bookmaker content: has always been possible by backing all outcomes with bookmakers (dutching), as opposed to laying an outcome on an exchange. Exchanges, however, allow bookmakers to see the state of the market and set their odds accordingly. With the increasing number of online betting exchanges, betting exchanges are now providing free bet offers in an attempt to lure customers away from the competition. These free bets are generally based on the size of the deposit made into the gambling account. For example, if a customer made a deposit of $20, the betting exchange would deposit an additional $20 for the customer


title: "Sunflower seed" content: Sunflower seed The sunflower seed is the fruit of the sunflower ("Helianthus annuus"). There are three types of commonly used sunflower seeds: linoleic (most common), high oleic, and NuSun developed for sunflower oil. Each variety has its own unique levels of monounsaturated, saturated, and polyunsaturated fats. The information in this article refers mainly to the linoleic variety. For commercial purposes, sunflower seeds are usually classified by the pattern on their husks. If the husk is solid black, the seeds are called black oil sunflower seeds. The crops may be referred to as oilseed sunflower crops. These seeds are usually pressed


title: "Sunflower seed" content: to extract their oil. Striped sunflower seeds are primarily used for food; as a result, they may be called confectionery sunflower seeds. The term "sunflower seed" is actually a misnomer when applied to the seed in its pericarp (hull). Botanically speaking, it is a cypsela. When dehulled, the edible remainder is called the sunflower kernel or heart. In 2014, global production of sunflower seeds was 41.4 million tonnes, led by Ukraine with 24% and Russia with 21% of the world total (table). China, Romania, and Argentina also contributed significant volumes. Sunflower seeds are more commonly eaten as a snack than


title: "Sunflower seed" content: as part of a meal. They can also be used as garnishes or ingredients in various recipes. The seeds may be sold as in-shell seeds or dehulled kernels. The seeds can also be sprouted and eaten in salads. When in-shell seeds are processed, they are first dried. Afterwards, they may also be roasted or dusted with salt or flour for preservation of flavor. Sunflower seeds sold by the bag are either eaten "plain" (salted only) or with a variety of flavorings added by the maker including barbecue, pickle, hot sauce, bacon, ranch, and nacho cheese as well as others. In-shell,


title: "Sunflower seed" content: sunflower seeds are particularly popular in Mediterranean, Eastern European, and Asian countries where they can be bought freshly roasted and are commonly consumed as street food, the hull being cracked open with the teeth and spit out, while in many countries, they can be bought freshly packed in various roasted flavors. In the United States, they are commonly eaten by baseball players as an alternative to chewing tobacco. Mechanically dehulled kernels may be sold raw or roasted and are sometimes added to bread and other baked goods for their flavor. There is also sunflower butter, similar to peanut butter, but


title: "Sunflower seed" content: using sunflower seeds instead of peanuts, which is a common substitute in schools for children with nut allergies. Apart from human consumption, sunflower seeds are also used as food for pets and wild birds in boxes and small bags. In a 100-gram serving, dried whole sunflower seeds provide 584 calories and are composed of 5% water, 20% carbohydrates, 51% total fat and 21% protein (table). The seeds are a rich source (20% or higher of the Daily Value, DV) of protein (42% DV), dietary fiber (36% DV), many B vitamins (23–129% DV) and vitamin E (234% DV). The seeds also


title: "Sunflower seed" content: contain high levels of dietary minerals, including magnesium, manganese, phosphorus, iron and zinc (40–94% DV). Half of a 100-gram serving is fat, mainly monounsaturated and polyunsaturated fats, principally linoleic acid. Additionally, the seeds contain phytosterols which may contribute toward lower levels of blood cholesterol. Over the past decades sunflower oil has become popular worldwide. The oil may be used as is, or may be processed into polyunsaturated margarines. The oil is typically extracted by applying great pressure to the sunflower seeds and collecting the oil. The protein-rich cake remaining after the seeds have been processed for oil is used as


title: "Sunflower seed" content: a livestock feed. The original sunflower oil (linoleic sunflower oil) is high in polyunsaturated fatty acids (about 68% linoleic acid) and low in saturated fats, such as palmitic acid and stearic acid. However, various hybrids have been developed to alter the fatty acid profile of the crop for various purposes. The hulls, or shells, mostly composed of cellulose, decomposes slowly and may be burned as biomass fuel. Sunflower hulls of the cultivated sunflower ("Helianthus annuus") contain allelopathic compounds which are toxic to grasses and the vast majority of cultivated garden plants. Only a small number of garden plants, such as


title: "Sunflower seed" content: day lilies, are unaffected by the allelopathic compounds found in sunflower hulls. Sunflower seed The sunflower seed is the fruit of the sunflower ("Helianthus annuus"). There are three types of commonly used sunflower seeds: linoleic (most common), high oleic, and NuSun developed for sunflower oil. Each variety has its own unique levels of monounsaturated, saturated, and polyunsaturated fats. The information in this article refers mainly to the linoleic variety. For commercial purposes, sunflower seeds are usually classified by the pattern on their husks. If the husk is solid black, the seeds are called black oil sunflower seeds. The crops may


title: "Water buffalo" content: Water buffalo The water buffalo ("Bubalus bubalis") or domestic Asian water buffalo is a large bovid originating in South Asia, Southeast Asia, and China. Today, it is also found in Europe, Australia, North America, South America and some African countries. The wild water buffalo ("Bubalus arnee") native to Southeast Asia is considered a different species, but most likely represents the ancestor of the domestic water buffalo. Two extant types of domestic water buffalo are recognized based on morphological and behavioural criteria – the river buffalo of South Asia and further west to the Balkans, Egypt, and Italy, and the swamp


title: "Water buffalo" content: buffalo, found from Assam in the west through Southeast Asia to the Yangtze valley of China in the east. The origins of the domestic water buffalo types are debated, although results of a phylogenetic study indicate that the swamp type may have originated in China and was domesticated about 4,000 years ago, while the river type may have originated in India and was domesticated about 5,000 years ago. Water buffalo were traded from the Indus Valley Civilisation to Mesopotamia, in modern Iraq, 2500 BC by the Meluhhas. The seal of a scribe employed by an Akkadian king shows the sacrifice


title: "Water buffalo" content: of water buffalo. At least 130 million domestic water buffalo exist, and more people depend on them than on any other domestic animal. They are especially suitable for tilling rice fields, and their milk is richer in fat and protein than that of dairy cattle. A large feral population became established in northern Australia in the late 19th century, and there are smaller feral herds in Papua New Guinea, Tunisia, and northeastern Argentina. Feral herds are also present in New Britain, New Ireland, Irian Jaya, Colombia, Guyana, Suriname, Brazil, and Uruguay. The skin of river buffalo is black, but some


title: "Water buffalo" content: specimens may have dark, slate-coloured skin. Swamp buffalo have a grey skin at birth, but become slate blue later. Albinoids are present in some populations. River buffalo have comparatively longer faces, smaller girths, and bigger limbs than swamp buffalo. Their dorsal ridges extend further back and taper off more gradually. Their horns grow downward and backward, then curve upward in a spiral. Swamp buffalo are heavy-bodied and stockily built; the body is short and the belly large. The forehead is flat, the eyes prominent, the face short, and the muzzle wide. The neck is comparatively long, and the withers and


title: "Water buffalo" content: croup are prominent. A dorsal ridge extends backward and ends abruptly just before the end of the chest. Their horns grow outward, and curve in a semicircle, but always remain more or less on the plane of the forehead. The tail is short, reaching only to the hocks. Height at withers is for males, and for females. They range in weight from , but weights of over have also been observed. "Tedong bonga" is a black pied buffalo featuring a unique black and white colouration that is favoured by the Toraja of Sulawesi. The swamp buffalo has 48 chromosomes; the


title: "Water buffalo" content: river buffalo has 50 chromosomes. The two types do not readily interbreed, but fertile offspring can occur. Buffalo-cattle hybrids have not been observed to occur, but the embryos of such hybrids reach maturity in laboratory experiments, albeit at lower rates than non-hybrids. The rumen of the water buffalo has important differences from that of other ruminants. It contains a larger population of bacteria, particularly the cellulolytic bacteria, lower protozoa, and higher fungi zoospores. In addition, higher rumen ammonia nitrogen (NH-N) and higher pH have been found as compared to those in cattle. River buffalo prefer deep water. Swamp buffalo prefer


title: "Water buffalo" content: to wallow in mudholes which they make with their horns. During wallowing, they acquire a thick coating of mud. Both are well adapted to a hot and humid climate with temperatures ranging from in the winter to and greater in the summer. Water availability is important in hot climates, since they need wallows, rivers, or splashing water to assist in thermoregulation. Some breeds are adapted to saline seaside shores and saline sandy terrain. Water buffalo thrive on many aquatic plants and during floods, will graze submerged, raising their heads above the water and carrying quantities of edible plants. They eat


title: "Water buffalo" content: reeds, "Arundo donax", a kind of "Cyperaceae", "Eichhornia crassipes", and "Juncaceae". Some of these plants are of great value to local peoples. Others, such as "E. crassipes", are a major problem in some tropical valleys and water buffalo may help to keep waterways clear. Green fodders are used widely for intensive milk production and for fattening. Many fodder crops are conserved as hay, chaffed, or pulped. Fodders include alfalfa, the leaves, stems or trimmings of banana, cassava, Mangelwurzel, esparto, "Leucaena leucocephala" and kenaf, maize, oats, "Pandanus", peanut, sorghum, soybean, sugarcane, bagasse, and turnips. Citrus pulp and pineapple wastes have been


title: "Water buffalo" content: fed safely to buffalo. In Egypt, whole sun-dried dates are fed to milk buffalo up to 25% of the standard feed mixture. Swamp buffalo generally become reproductive at an older age than river breeds. Young males in Egypt, India, and Pakistan are first mated at about 3.0–3.5 years of age, but in Italy they may be used as early as 2 years of age. Successful mating behaviour may continue until the animal is 12 years or even older. A good river male can impregnate 100 females in a year. A strong seasonal influence on mating occurs. Heat stress reduces libido.


title: "Water buffalo" content: Although buffalo are polyoestrous, their reproductive efficiency shows wide variation throughout the year. Buffalo cows exhibit a distinct seasonal change in displaying oestrus, conception rate, and calving rate. The age at first oestrus of heifers varies between breeds from 13–33 months, but mating at the first oestrus is often infertile and usually deferred until they are 3 years old. Gestation lasts from 281–334 days, but most reports give a range between 300 and 320 days. Swamp buffalo carry their calves for one or two weeks longer than river buffalo. It is not rare to find buffalo that continue to work


title: "Water buffalo" content: well at the age of 30, and instances of a working life of 40 years are recorded. Carl Linnaeus first described the genus "Bos" and the water buffalo under the binomial "Bos bubalis" in 1758; the species was known to occur in Asia and was held as a domestic form in Italy. Ellerman and Morrison-Scott treated the wild and domestic forms of the water buffalo as conspecifics, whereas others treated them as different species. The nomenclatorial treatment of wild and domestic forms has been inconsistent and varies between authors and even within the works of single authors. In March 2003,


title: "Water buffalo" content: the International Commission on Zoological Nomenclature achieved consistency in the naming of wild and domestic water buffalo by ruling that the scientific name "Bubalus arnee" is valid for the wild form. "B. bubalis" continues to be valid for the domestic form and applies also to feral populations. Water buffalo were domesticated in Indian subcontinent about 5000 years ago, and in China about 4000 years ago. Two types are recognized, based on morphological and behavioural criteria – the river buffalo of the Indian subcontinent and further west to the Balkans and Italy, and the swamp buffalo, found from Assam in the


title: "Water buffalo" content: west through Southeast Asia to the Yangtze valley of China in the east. The present-day river buffalo is the result of complex domestication processes involving more than one maternal lineage and a significant maternal gene flow from wild populations after the initial domestication events. Twenty-two breeds of the river type water buffalo are known, including Murrah, NiliRavi, Surti, Jafarabadi, Anatolian, Mediterranean, and Egyptian buffalo. China has a huge variety of buffalo genetic resources, comprising 16 local swamp buffalo breeds in various regions. Results of mitochondrial DNA analyses indicate that the two types were domesticated independently. Sequencing of cytochrome b genes


title: "Water buffalo" content: of "Bubalus" species implies that the domestic buffalo originated from at least two populations, and that the river and the swamp types have differentiated at the full species level. The genetic distance between the two types is so large that a divergence time of about 1.7 million years has been suggested. The swamp type was noticed to have the closest relationship with the tamaraw. By 2011, the global water buffalo population was about 172 million head. More than 95.8% of the world population of water buffalo are kept in Asia, including both river and swamp types. The water buffalo population


title: "Water buffalo" content: in India numbered over 97.9 million head in 2003, representing 56.5% of the world population. They are primarily of the river type, with 10 well-defined breeds comprising Badhawari, Murrah, Nili-Ravi, Jafarabadi, Marathwada, Mehsana, Nagpuri, Pandharpuri, Toda, and Surti. Swamp buffalo occur only in small areas in north-eastern India and are not distinguished into breeds. In 2003, the second-largest population lived in China, with 22.76 million head, all of the swamp type with breeds kept only in the lowlands, and other breeds kept only in the mountains; as of 2003, 3.2 million swamp-type carabao buffalo were in the Philippines, nearly three


title: "Water buffalo" content: million swamp buffalo were in Vietnam, and 772,764 buffalo were in Bangladesh. About 750,000 head were estimated in Sri Lanka in 1997. In Japan, water buffalo is domestic animal throughout the Ryukyuan islands or Okinawa prefecture. It was also recorded that 889,246 buffalo were in Nepal. The water buffalo is the main dairy animal in Pakistan, with 23.47 million head in 2010. Of these, 76% are kept in the Punjab. The rest of them are mostly in the province of Sindh. Breeds used are NiliRavi, Kundi, and Azi Kheli. Karachi has the largest population of water buffalos for an area


title: "Water buffalo" content: where fodder is not grown, consisting of 350,000 head kept mainly for milking. In Thailand, the number of water buffalo dropped from more than 3 million head in 1996 to less than 1.24 million head in 2011. Slightly over 75% of them are kept in the country's northeastern region. The statistics also indicate that by the beginning of 2012, less than one million were in the country, partly as a result of illegal shipments to neighboring countries where sales prices are higher than in Thailand. Water buffalo are also present in the southern region of Iraq in the Mesopotamian Marshes.


title: "Water buffalo" content: The draining of the Mesopotamian Marshes by Saddam Hussein was an attempt to punish the south for the 1991 uprisings in Iraq. After 2003 and the Firdos Square statue destruction, these lands were reflooded and a 2007 report on Maysan and Dhi Qar shows a steady increase in the number of water buffalo. The report puts the number at 40,008 head in those two provinces. Water buffalo were probably introduced to Europe from India or other eastern sources. In Italy, the Longobard King Agilulf is said to have received water buffalo in about the year 600. These were probably a


title: "Water buffalo" content: present from the Khan of the Avars, a Turkic nomadic tribe that dwelt near the Danube River at the time. Sir H. Johnston knew of a herd of water buffalo presented by a King of Naples to the Bey of Tunis in the mid-19th century that had resumed the feral state in northern Tunis. European buffalo are all of the river type and considered to be of the same breed named Mediterranean buffalo. In Italy, the Mediterranean type was particularly selected and is called Mediterranean Italian breed to distinguish it from other European breeds, which differ genetically. Mediterranean buffalo are


title: "Water buffalo" content: also kept in Romania, Bulgaria, Greece, Albania, Kosovo, and the Republic of Macedonia, with a few hundred in the United Kingdom, Germany, the Netherlands, Switzerland, and Hungary. Little exchange of breeding buffalo has occurred among countries, so each population has its own phenotypic features and performances. In Bulgaria, they were crossbred with the Indian Murrah breed, and in Romania, some were crossbred with Bulgarian Murrah. Populations in Turkey are of the Anatolian buffalo breed. Between 1824 and 1849, water buffalo were introduced into the Northern Territory from Timor, Kisar, and probably other islands in the Indonesian archipelago. In 1886, a


title: "Water buffalo" content: few milking types were brought from India to Darwin. They have been the main grazing animals on the subcoastal plains and river basins between Darwin and Arnhem Land since the 1880s. In the early 1960s, an estimated population of 150,000 to 200,000 buffalo were living in the plains and nearby areas. They became feral and are causing significant environmental damage. Buffalo also occur in the Top End. As a result, they were hunted in the Top End from 1885 until 1980. The commencement of the brucellosis and tuberculosis campaign (BTEC) resulted in a huge culling program to reduce buffalo herds


title: "Water buffalo" content: to a fraction of the numbers that were reached in the 1980s. The BTEC was finished when the Northern Territory was declared free of the disease in 1997. Numbers dropped dramatically as a result of the campaign, but have since recovered to an estimated 150,000 animals across northern Australia in 2008. During the 1950s, buffalo were hunted for their skins and meat, which was exported and used in the local trade. In the late 1970s, live exports were made to Cuba and continued later into other countries. Buffalo are now crossed with riverine buffalo in artificial insemination programs, and are


title: "Water buffalo" content: kept in many areas of Australia. Some of these crossbreds are used for milk production. Melville Island is a popular hunting location, where a steady population up to 4,000 individuals exists. Safari outfits are run from Darwin to Melville Island and other locations in the Top End, often with the use of bush pilots. The horns, which can measure up to a record of tip-to-tip, are prized hunting trophies. The buffalo have developed a different appearance from the Indonesian buffalo from which they descend. They live mainly in freshwater marshes and billabongs, and their territory range can be quite expansive


title: "Water buffalo" content: during the wet season. Their only natural predators in Australia are adult saltwater crocodiles, with whom they share the billabongs, and dingoes, which have been known to prey on buffalo calves and occasionally adult buffalo when the dingoes are in large packs. Buffalo were exported live to Indonesia until 2011, at a rate of about 3000 per year. After the live export ban that year, the exports dropped to zero, and had not resumed as of June 2013. Water buffalo were introduced into the Amazon River basin in 1895. They are now extensively used there for meat and dairy production.


title: "Water buffalo" content: In 2005, the buffalo herd in the Brazilian Amazon stood at roughly 1.6 million head, of which 460,000 were located in the lower Amazon floodplain. Breeds used include Mediterranean from Italy, Murrah and Jafarabadi from India, and Carabao from the Philippines. During the 1970s, small herds were imported to Costa Rica, Ecuador, Cayenne, Panama, Surinam, Guyana, and Venezuela. In Argentina, many game ranches raise water buffalo for commercial hunting. In 1974, four water buffalo were imported to the United States from Guam to be studied at the University of Florida. In February 1978, the first herd arrived for commercial farming.


title: "Water buffalo" content: Until 2002, only one commercial breeder was in the United States. Water buffalo meat is imported from Australia. Until 2011, water buffalo were raised in Gainesville, Florida, from young obtained from zoo overflow. They were used primarily for meat production, frequently sold as hamburger. Other US ranchers use them for production of high-quality mozzarella cheese. The husbandry system of water buffalo depends on the purpose for which they are bred and maintained. Most of them are kept by people who work on small farms in family units. Their buffalo live in very close association with them, and are often their


title: "Water buffalo" content: greatest capital asset. The women and girls in India generally look after the milking buffalo while the men and boys are concerned with the working animals. Throughout Asia, they are commonly tended by children who are often seen leading or riding their charges to wallowing places. Water buffalo are the ideal animals for work in the deep mud of paddy fields because of their large hooves and flexible foot joints. They are often referred to as "the living tractor of the East". It probably is possible to plough deeper with buffalo than with either oxen or horses. They are the


title: "Water buffalo" content: most efficient and economical means of cultivation of small fields. In most rice-producing countries, they are used for threshing and for transporting the sheaves during the rice harvest. They provide power for oilseed mills, sugarcane presses, and devices for raising water. They are widely used as pack animals, and in India and Pakistan also for heavy haulage. In their invasions of Europe, the Turks used buffalo for hauling heavy battering rams. Their dung is used as a fertilizer, and as a fuel when dried. Buffalo contribute 72 million tones of milk and three million tones of meat annually to world


title: "Water buffalo" content: food, much of it in areas that are prone to nutritional imbalances. In India, river-type buffalo are kept mainly for milk production and for transport, whereas swamp-type buffalo are kept mainly for work and a small amount of milk. Water buffalo milk presents physicochemical features different from that of other ruminant species, such as a higher content of fatty acids and proteins. The physical and chemical parameters of swamp and river type water buffalo milk differ. Water buffalo milk contains higher levels of total solids, crude protein, fat, calcium, and phosphorus, and slightly higher content of lactose compared with those


title: "Water buffalo" content: of cow milk. The high level of total solids makes water buffalo milk ideal for processing into value-added dairy products such as cheese. The conjugated linoleic acid (CLA) content in milk ranged from 4.4 mg/g fat in September to 7.6 mg/g fat in June. Seasons and genetics may play a role in variation of CLA level and changes in gross composition of the water buffalo milk. Water buffalo milk is processed into a large variety of dairy products: Water buffalo meat, sometimes called "carabeef", is often passed off as beef in certain regions, and is also a major source of


title: "Water buffalo" content: export revenue for India. In many Asian regions, buffalo meat is less preferred due to its toughness; however, recipes have evolved ("rendang", for example) where the slow cooking process and spices not only make the meat palatable, but also preserve it, an important factor in hot climates where refrigeration is not always available. Their hides provide tough and useful leather, often used for shoes. The bones and horns are often made into jewellery, especially earrings. Horns are used for the embouchure of musical instruments, such as "ney" and "kaval". Wildlife conservation scientists have started to recommend and use introduced populations


title: "Water buffalo" content: of feral domestic water buffalo in far-away lands to manage uncontrolled vegetation growth in and around natural wetlands. Introduced water buffalo at home in such environs provide cheap service by regularly grazing the uncontrolled vegetation and opening up clogged water bodies for waterfowl, wetland birds, and other wildlife. Grazing water buffalo are sometimes used in Great Britain for conservation grazing, such as in Chippenham Fen National Nature Reserve. The buffalo can better adapt to wet conditions and poor-quality vegetation than cattle. Currently, research is being conducted at the Lyle Center for Regenerative Studies to determine the levels of nutrients removed


title: "Water buffalo" content: and returned to wetlands when water buffalo are used for wetland vegetation management. However, in uncontrolled circumstances, water buffalo can cause environmental damage, such as trampling vegetation, disturbing bird and reptile nesting sites, and spreading exotic weeds. In 2007, the development of Southeast Asia's first cloned buffalo was announced in the Philippines. The Department of Agriculture's Philippine Carabao Center implemented cloning through somatic cell nuclear transfer as a tool for genetic improvement in water buffalo to produce "super buffalo calves" by multiplying existing germplasms but without modifying or altering genetic material. In January 2008, the Philippine Carabao Center in Nueva


title: "Water buffalo" content: Ecija, per Filipino scientists, initiated a study to breed a super water buffalo that could produce 4 to 18 litres of milk per day using gene-based technology. Also, the first "in vitro" river buffalo was born there in 2004 from an "in vitro"-produced, vitrified embryo, named "Glory" after President Gloria Macapagal-Arroyo. Joseph Estrada's most successful project as an opposition senator, the PCC was created through Republic Act 3707, the Carabao Act of 1992. Indian scientists from the National Dairy Research Institute, Karnal developed a cloned buffalo in 2010. The buffalo calf was named Samrupa. The calf did not survive more


title: "Water buffalo" content: than a week, due to genetic defects. A few months later, a second cloned calf was successfully born, named Garima. The Central Institute for Research on Buffaloes, India's premier research institute on buffalo, also became the second institute in the world to successfully clone the buffalo in 2016. Water buffalo The water buffalo ("Bubalus bubalis") or domestic Asian water buffalo is a large bovid originating in South Asia, Southeast Asia, and China. Today, it is also found in Europe, Australia, North America, South America and some African countries. The wild water buffalo ("Bubalus arnee") native to Southeast Asia is considered


title: "1066 and All That" content: Roman Conquest is the first of 103 historical events in the book characterised as a "Good Thing", "since the Britons were only natives at that time". Chapter II begins "that long succession of Waves of which History is chiefly composed", the first of which, here, is composed of Ostrogoths, Visigoths, mere Goths, Vandals, and Huns. Later examples are the "Wave of Saints", who include the Venomous Bead (Chapter III); "Waves of Pretenders", usually divided into smaller waves of two: an Old Pretender and a Young Pretender (Chapter XXX); plus the "Wave of Beards" in the Elizabethan era (Chapter XXXIII). According


title: "Austronesian languages" content: local groups with little large-scale structure. The first was Malayo-Polynesian, distributed across the Philippines, Indonesia, and Melanesia. The Central Malayo-Polynesian languages are similar to each other not because of close genealogical relationships, but rather because they reflect strong substratum effects from non-Austronesian languages. The second migration was that of the Oceanic languages into Polynesia and Micronesia . In addition to Malayo-Polynesian, thirteen Formosan families are broadly accepted. Debate centers primarily around the relationships between these families. Of the classifications presented here, links two families into a Western Plains group, two more in a Northwestern Formosan group, and three into an


title: "Lake Zug" content: Lake Zug Lake Zug () is a lake in Central Switzerland, situated between Lake Lucerne and Lake Zurich. It stretches for 14 km between Arth and the Cham-Zug bay. The Lorze as the main feeder river empties its waters into the lake at its northern extremity, but 1 km (0.6 mi) further west issues from the lake to pursue its course towards the Reuss. Due to this poor feeding, Environmental protection is very important as the lake would suffer long term damage if polluted as the second of the rivers, "Rigiaa", feeds only a marginal amount into the lake at


title: "Lake Zug" content: its southern end. Already a great part of the fauna in the deep parts of the lake has been lost. The lake is mostly within the borders of the Canton of Zug, with about at its southern end in the canton Schwyz, while the Canton of Lucerne claims about to the north of Immensee. Toward the south-west extremity of the lake the Rigi descends rather steeply to the water's edge, while part of its east shore forms a narrow level band at the foot of the 1,583 m (5,194 ft) Rossberg, and the Zugerberg. The culminating point of the lake's


title: "Lake Zug" content: drainage basin is the summit of the Rigi at 1,798 m. At its northern end, the shores are nearly level, while on the west shore the wooded promontory of Buonas (with its castles, old and new) projects picturesquely into the waters. The principal place on the lake is the town of Zug. Three railways follow the shore of the lake, one from Zurich via Zug and Arth-Goldau to the St Gotthard, one from Lucerne via Arth-Goldau to the St Gotthard, and the third from Zurich via Zug to Lucerne. Many fish (including pike and carp of considerable weights) are taken


title: "Lake Zug" content: in the lake, which is especially famous for an endemic kind of trout ("Salmo salvelinus", locally called "Rolheli"). The first steamer was placed on the lake in 1852. In the early 20th century, a railway (formerly part of the St. Gotthard main route) ran along its eastern shore past Walchwil to Arth at its south end, which was connected initially by a steam tramway with the Arth-Goldau station of the St Gotthard line. This line runs from Arth along the western shore to Immensee, where it bears south-west to Lucerne, while from Immensee another railway leads (at first some way


title: "Lake Zug" content: from the shore) to Cham, west of Zug. Public transportation on Lake Zug is done by the Zugersee Schifffahrt / Schifffahrtsgesellschaft für den Zugersee AG (SGZ) . Lake Zug Lake Zug () is a lake in Central Switzerland, situated between Lake Lucerne and Lake Zurich. It stretches for 14 km between Arth and the Cham-Zug bay. The Lorze as the main feeder river empties its waters into the lake at its northern extremity, but 1 km (0.6 mi) further west issues from the lake to pursue its course towards the Reuss. Due to this poor feeding, Environmental protection is very


title: "Confirmation bias" content: violates it, such as (11,12,19). Wason accepted falsificationism, according to which a scientific test of a hypothesis is a serious attempt to falsify it. He interpreted his results as showing a preference for confirmation over falsification, hence the term "confirmation bias". Wason also used confirmation bias to explain the results of his selection task experiment. In this task, participants are given partial information about a set of objects, and have to specify what further information they would need to tell whether or not a conditional rule ("If A, then B") applies. It has been found repeatedly that people perform badly


title: "Carroll County, Maryland" content: lines cross Carroll County. The old Baltimore and Ohio (B&O) Old Main Line crosses the southern part of the county from east to west, with former stations in Sykesville and Mount Airy. The original Western Maryland Railway (WM) main line track runs southeast to northwest through Carrollton, Westminster, New Windsor, and Union Bridge. The old Baltimore and Hanover Railroad (later acquired by WM) runs further to the east through Hampstead, Millers, and Lineboro. Two of these railroad lines are now operated by CSX Transportation; the former WM main line is now operated by Maryland Midland Railway. As of the census


title: "Royal Welch Fusiliers" content: Battalion, Parachute Regiment. The 6th Parachute Battalion was assigned to the 2nd Parachute Brigade, alongside the 4th and 5th Parachute battalions, originally part of the 1st Airborne Division. The battalion played a small part in the Allied invasion of Italy during Operation Slapstick, an amphibious landing aimed at capturing the port of Taranto. After that, the 2nd Para Brigade became an independent brigade group. The brigade took part in Operation Dragoon, the Allied invasion of Southern France, being the only British troops to do so (see 2nd Parachute Brigade in Southern France). The brigade returned to Italy before being sent


title: "White-nosed coati" content: White-nosed coati The white-nosed coati ("Nasua narica"), also known as the coatimundi (), is a species of coati and a member of the family Procyonidae (raccoons and their relatives). Local Spanish names for the species include pizote, antoon, and tejón, depending upon the region. It weighs about . However, males are much larger than females: small females can weigh as little as , while large males can weigh as much as . On average, the nose-to-tail length of the species is about with about half of that being the tail length. White-nosed coatis inhabit wooded areas (dry and moist forests)


title: "White-nosed coati" content: of the Americas. They are found at any altitude from sea level to , and from as far north as southeastern Arizona and New Mexico, through Mexico and Central America, to far northwestern Colombia (Gulf of Urabá region, near Colombian border with Panama). There has been considerable confusion over its southern range limit, but specimen records from most of Colombia (only exception is far northwest) and Ecuador are all South American coatis. Coatis from Cozumel Island have been treated as a separate species, the Cozumel Island coati, but the vast majority of recent authorities treat it as a subspecies, "N.


title: "White-nosed coati" content: narica nelsoni", of the white-nosed coati. They are smaller than white-nosed coatis from the adjacent mainland ("N. n. yucatanica"), but when compared more widely to white-nosed coatis the difference in size is not as clear. The level of other differences also support its status as a subspecies rather than separate species. White-nosed coatis have also been found in the U.S. state of Florida, where they are an introduced species. It is unknown precisely when introduction occurred; an early specimen in the Florida Museum of Natural History, labeled an "escaped captive", dates to 1928. There are several later documented cases of


title: "White-nosed coati" content: coatis escaping captivity, and since the 1970s there have been a number of sightings, and several live and dead specimens of various ages have been found. These reports have occurred over a wide area of southern Florida, and there is probable evidence of breeding, indicating that the population is well established. They are omnivores, preferring small vertebrates, fruits, carrion, insects, snakes and eggs. They can climb trees easily, where the tail is used for balance, but they are most often on the ground foraging. Their predators include boas, raptors, hunting cats, and Tayras ("Eira barbara"). They readily adapt to human


title: "White-nosed coati" content: presence; like raccoons, they will raid campsites and trash receptacles. They can be tamed easily, and have been verified experimentally to be quite intelligent. While the raccoon and ringtail are nocturnal, coatis are active by day, retiring during the night to a specific tree and descending at dawn to begin their daily search for food. However, their habits are adjustable, and in areas where they are hunted by humans for food, or where they raid human settlements for their own food, they might become more nocturnal. Adult males are solitary, but females and sexually immature males form social groups. They


title: "White-nosed coati" content: use many vocal signals to communicate with one another, and also spend time grooming themselves and each other with their teeth and claws. During foraging times, the young cubs are left with a pair of babysitters, similar to meerkats. The young males and even some females tend to play-fight. Many of the coatis will have short fights over food. White-nosed coati The white-nosed coati ("Nasua narica"), also known as the coatimundi (), is a species of coati and a member of the family Procyonidae (raccoons and their relatives). Local Spanish names for the species include pizote, antoon, and tejón, depending


title: "Trusted Computing" content: to change from Office to OpenOffice right now merely has to install the software, train the staff and convert their existing files. In five years' time, once they have received TC-protected documents from perhaps a thousand different clients, they would have to get permission (in the form of signed digital certificates) from each of these clients in order to migrate their files to a new platform. The law firm won't in practice want to do this, so they will be much more tightly locked in, which will enable Microsoft to hike its prices. Anderson summarizes the case by saying: The


title: "Maclura pomifera" content: Maclura pomifera Maclura pomifera, commonly known as the Osage orange, is a small deciduous tree or large shrub, typically growing to tall. The distinctive fruit, from a multiple fruit family, is roughly spherical, bumpy, in diameter, and turns bright yellow-green in the fall. The fruits secrete a sticky white latex when cut or damaged. Despite the name "Osage orange", it is only distantly related to the orange, but rather is a member of the mulberry family, Moraceae. Due to its latex secretions and woody pulp, the fruit is typically not eaten by humans and rarely by foraging animals, giving it


title: "Maclura pomifera" content: distinction as an anachronistic "ghost of evolution". "Maclura pomifera" has been known by a variety of common names in addition to Osage orange, including hedge apple, horse apple, bois d'arc, bodark, monkey ball, bow-wood, yellow-wood and mock orange. The earliest account of the tree in the English language was given by William Dunbar, a Scottish explorer, in his narrative of a journey made in 1804 from St. Catherine's Landing on the Mississippi River to the Ouachita River. It was a curiosity when Meriwether Lewis sent some slips and cuttings to President Jefferson in March 1804. According to Lewis's letter, the


title: "Maclura pomifera" content: samples were donated by "Mr. Peter Choteau, who resided the greater portion of his time for many years with the Osage Nation." Those cuttings did not survive, but later the thorny Osage orange tree was widely naturalized throughout the United States. In 1810, Bradbury relates that he found two trees growing in the garden of Pierre Chouteau, one of the first settlers of St. Louis, apparently the same person. The trees acquired the name "bois d'arc", or "bow-wood", from early French settlers who observed the wood being used for war clubs and bow-making by Native Americans. Meriwether Lewis was told


title: "Maclura pomifera" content: that the people of the Osage Nation, "So much … esteem the wood of this tree for the purpose of making their bows, that they travel many hundreds of miles in quest of it." The trees are also known as "bodark" or "bodarc" trees, most likely originating from a corruption of "bois d'arc." The Comanches also used this wood for their bows. It was popular with them because it was strong, flexible and durable, and was common along river bottoms of the Comanchería. Some historians believe that the high value this wood had to Native Americans throughout North America for


title: "Maclura pomifera" content: the making of bows, along with its small natural range, contributed to the great wealth of the Spiroan Mississippian culture that controlled all the land in which these trees grew. The genus "Maclura" is named in honor of William Maclure (1763–1840), a Scottish-born American geologist. The specific epithet "pomifera" means "fruit-bearing". The common name "Osage" derives from Osage Native Americans from whom young plants were first obtained, as told in the notes of Meriwether Lewis in 1804. Mature trees range from tall with short trunks and round-topped canopies. The roots are thick, fleshy, and covered with bright orange bark. The


title: "Maclura pomifera" content: tree's mature bark is dark, deeply furrowed and scaly. The plant has significant potential to invade unmanaged habitats. The wood of "M. pomifera" is bright orange-yellow with paler yellow sapwood. The wood is heavy, hard, strong, and flexible, capable of receiving a fine polish and very durable in contact with the ground. It has a specific gravity of 0.7736 or . Leaves are arranged alternately in a slender growing shoot long. In form they are simple, a long oval terminating in a slender point. The leaves are long and wide, and are thick, firm, dark green, shining above, and paler


title: "Maclura pomifera" content: green below when full grown. In autumn they turn bright yellow. The leaf axils contain formidable spines which when mature are about long. Branchlets are at first bright green and pubescent; during their first winter they become light brown tinged with orange, and later they become a paler orange brown. Branches contain a yellow pith, and are armed with stout, straight, axillary spines. During the winter, the branches bear lateral buds that are depressed-globular, partly immersed in the bark, and pale chestnut brown in color. As a dioecious plant, the inconspicuous pistillate (female) and staminate (male) flowers are found on


title: "Maclura pomifera" content: different trees. Staminate flowers are pale green, small, and arranged in racemes borne on long, slender, drooping peduncles developed from the axils of crowded leaves on the spur-like branchlets of the previous year. They feature a hairy, four-lobed calyx; the four stamens are inserted opposite the lobes of calyx, on the margin of a thin disk. Pistillate flowers are borne in a dense spherical many-flowered head which appears on a short stout peduncle from the axils of the current year's growth. Each flower has a hairy four-lobed calyx with thick, concave lobes that invest the ovary and enclose the fruit.


title: "Maclura pomifera" content: Ovaries are superior, ovate, compressed, green, and crowned by a long slender style covered with white stigmatic hairs. The ovule is solitary. The mature multiple fruit's size and general appearance resembles a large, yellow-green orange, in diameter, with a roughened and tuberculated surface. The compound fruit is a syncarp of numerous small drupes, in which the carpels (ovaries) have grown together. Each small drupe is oblong, compressed and rounded; they contain a milky latex which oozes when the fruit is damaged or cut. The seeds are oblong. Although the flowering is dioecious, the pistillate tree when isolated will still bear


title: "Maclura pomifera" content: large oranges, perfect to the sight but lacking the seeds. The fruit has a cucumber-like flavor. Osage orange's pre-Columbian range was largely restricted to a small area in what is now the United States, namely the Red River drainage of Oklahoma, Texas, and Arkansas, as well as the Blackland Prairies and post oak savannas. A disjunct population also occurred in the Chisos Mountains of Texas. It has since become widely naturalized in the United States and Ontario, Canada. Osage orange has been planted in all the 48 contiguous states of the United States and in southeastern Canada. The largest known


title: "Maclura pomifera" content: Osage orange tree is located at River Farm, in Alexandria, Virginia, and is believed to have been a gift from Thomas Jefferson. Another historic tree is located on the grounds of Fort Harrod, a Kentucky pioneer settlement in Harrodsburg, Kentucky. The natural mechanism of seed dispersal for Osage orange, and the reason for its limited historical range despite its adaptability, has been the subject of debate. One hypothesis is that the Osage orange fruit was eaten by a giant ground sloth that became extinct shortly after the first human settlement of North America. Other extinct Pleistocene megafauna, such as the


title: "Maclura pomifera" content: mammoth, mastodon and gomphothere, may have fed on the fruit and aided in seed dispersal. An equine species that became extinct at the same time also has been suggested as the plant's original dispersal agent because modern horses and other livestock will sometimes eat the fruit. However, a 2015 study indicated that Osage orange seeds are not effectively spread by horses or elephant species. The fruit is not poisonous to humans or livestock, but is not preferred by them because it is mostly inedible due to a large size (about the diameter of a softball), and hard, dry texture. The


title: "Maclura pomifera" content: edible seeds of the fruit are used by squirrels as food. Large animals such as livestock, which typically would consume fruits and disperse seeds, mainly ignore the fruit. "Maclura pomifera" prefers a deep and fertile soil, but it is able to adapt to be hardy over most of the contiguous United States, where it is used as a hedge plant. It must be regularly pruned to keep it in bounds, and the shoots of a single year will grow long. A neglected hedge will soon become fruit-bearing. It is remarkably free from insect enemies and fungal diseases. A thornless male


title: "Maclura pomifera" content: cultivar of the species exists and is vegetatively reproduced for ornamental use. "M. pomifera" is cultivated in Italy, former Yugoslavia, Romania, former USSR, and India. Osajin and pomiferin are isoflavones present in the wood and fruit in an approximately 1:2 ratio by weight, and in turn comprise 4-6% of the weight of dry fruit and wood samples. Primary components of fresh fruit include pectin (46%), resin (17%), fat (5%), and sugar (before hydrolysis, 5%). The moisture content of fresh fruits is about 80%. The Osage orange is commonly used as a tree row windbreak in prairie states, which gives it


title: "Maclura pomifera" content: one of its colloquial names, "hedge apple". It was one of the primary trees used in President Franklin Delano Roosevelt's "Great Plains Shelterbelt" WPA project, which was launched in 1934 as an ambitious plan to modify weather and prevent soil erosion in the Great Plains states, and by 1942 resulted in the planting of 30,233 shelterbelts containing 220 million trees that stretched for . The sharp-thorned trees were also planted as cattle-deterring hedges before the introduction of barbed wire and afterward became an important source of fence posts. In 2001, its wood was used in the construction in Chestertown, Maryland


title: "Maclura pomifera" content: of the "Schooner Sultana", a replica of . The heavy, close-grained yellow-orange wood is dense and prized for tool handles, treenails, fence posts, and other applications requiring a strong dimensionally stable wood that withstands rot. Although its wood is commonly knotty and twisted, straight-grained Osage orange timber makes good bows, as once used by Native Americans. John Bradbury, a Scottish botanist who had traveled the interior United States extensively in the early 19th century, reported that a bow made of Osage timber could be traded for a horse and a blanket. Additionally, a yellow-orange dye can be extracted from the


title: "Maclura pomifera" content: wood, which can be used as a substitute for fustic and aniline dyes. At present, florists use the fruits of "M. pomifera" for decorative purposes. When dried, the wood has the highest BTU content of any commonly available North American wood, and burns long and hot. Unlike many woods, Osage orange wood is durable, making good fence posts. They are generally set up green because the dried wood is too hard to reliably accept the staples used to attach the fencing to the posts. Palmer and Fowler's "Fieldbook of Natural History" 2nd edition, rates Osage orange wood as being at


title: "Maclura pomifera" content: least twice as hard and strong as white oak ("Quercus alba"). Its dense grain structure makes for good tonal properties. Production of woodwind instruments and waterfowl game calls are common uses for the wood. Although Osage oranges are commonly believed to repel insects, there is insufficient evidence to support this. Research has shown that compounds extracted from the fruit, when concentrated, may repel insects. However, the naturally occurring concentrations of these compounds in the fruit are far too low to make the fruit an effective insect repellent. In 2004, the EPA insisted that a website selling "M. pomifera" fruits online


title: "Maclura pomifera" content: remove any mention of their supposed pesticidal properties as false advertisements. The Comanche tribe historically used a root/water infusion for eye conditions. Maclura pomifera Maclura pomifera, commonly known as the Osage orange, is a small deciduous tree or large shrub, typically growing to tall. The distinctive fruit, from a multiple fruit family, is roughly spherical, bumpy, in diameter, and turns bright yellow-green in the fall. The fruits secrete a sticky white latex when cut or damaged. Despite the name "Osage orange", it is only distantly related to the orange, but rather is a member of the mulberry family, Moraceae. Due


title: "An Inspector Calls" content: it or fails to accept it and still insists on unsuccessfully covering it up around the Inspector). She is around 50 years old, as mentioned in the pre-play stage directions, highlighting she belongs to the older generation. Sheila is the Birlings' elder child. She is described as a "pretty girl in her early twenties", delighted about her engagement to Gerald Croft. She starts out as a playful, self-centred girl who loves attention. She also knows of Eric Birling's heavy drinking. Throughout the play, she becomes the most sympathetic family member, showing remorse upon hearing the news of her part in


title: Johannesburg content: from central Africa and encroached on the indigenous San population. By the mid-18th century, the broader region was largely settled by various Sotho–Tswana communities (one linguistic branch of Bantu-speakers), whose villages, towns, chiefdoms and kingdoms stretched from what is now Botswana in the west, to present day Lesotho in the south, to the present day Pedi areas of the Northern Province. More specifically, the stone-walled ruins of Sotho–Tswana towns and villages are scattered around the parts of the former Transvaal province in which Johannesburg is situated. The Sotho–Tswana practised farming and extensively mined and smelted metals that were available in


title: "Unmanned aerial vehicle" content: Unmanned aerial vehicle An unmanned aerial vehicle (UAV), commonly known as a drone, is an aircraft without a human pilot aboard. UAVs are a component of an unmanned aircraft system (UAS); which include a UAV, a ground-based controller, and a system of communications between the two. The flight of UAVs may operate with various degrees of autonomy: either under remote control by a human operator or autonomously by onboard computers.<ref name="ICAO's circular 328 AN/190"></ref> Compared to manned aircraft, UAVs were originally used for missions too "dull, dirty or dangerous" for humans. While they originated mostly in military applications, their use


title: "Unmanned aerial vehicle" content: is rapidly expanding to commercial, scientific, recreational, agricultural, and other applications, such as policing, peacekeeping, and surveillance, product deliveries, aerial photography, agriculture, smuggling, and drone racing. Civilian UAVs now vastly outnumber military UAVs, with estimates of over a million sold by 2015, so they can be seen as an early commercial application of autonomous things, to be followed by the autonomous car and home robots. Multiple terms are used for unmanned aerial vehicles, which generally refer to the same concept. The term drone, more widely used by the public, was coined in reference to the early remotely-flown target aircraft used


title: "Unmanned aerial vehicle" content: for practice firing of a battleship's guns, and the term was first used with the 1920s Fairey Queen and 1930's de Havilland Queen Bee target aircraft. These two were followed in service by the similarly-named Airspeed Queen Wasp and Miles Queen Martinet, before ultimate replacement by the GAF Jindivik. The term "unmanned aircraft system" (UAS) was adopted by the United States Department of Defense (DoD) and the United States Federal Aviation Administration in 2005 according to their Unmanned Aircraft System Roadmap 2005–2030. The International Civil Aviation Organization (ICAO) and the British Civil Aviation Authority adopted this term, also used in


title: "Unmanned aerial vehicle" content: the European Union's Single-European-Sky (SES) Air-Traffic-Management (ATM) Research (SESAR Joint Undertaking) roadmap for 2020. This term emphasizes the importance of elements other than the aircraft. It includes elements such as ground control stations, data links and other support equipment. A similar term is an "unmanned-aircraft vehicle system" (UAVS), "remotely piloted aerial vehicle" (RPAV), "remotely piloted aircraft system" (RPAS). Many similar terms are in use. A UAV is defined as a "powered, aerial vehicle that does not carry a human operator, uses aerodynamic forces to provide vehicle lift, can fly autonomously or be piloted remotely, can be expendable or recoverable, and


title: "Unmanned aerial vehicle" content: can carry a lethal or nonlethal payload". Therefore, missiles are not considered UAVs because the vehicle itself is a weapon that is not reused, though it is also unmanned and in some cases remotely guided. The relation of UAVs to remote controlled model aircraft is unclear. UAVs may or may not include model aircraft. Some jurisdictions base their definition on size or weight; however, the US Federal Aviation Administration defines any unmanned flying craft as a UAV regardless of size. For recreational uses, a drone (as opposed to a UAV) is a model aircraft that has first-person video, autonomous capabilities,


title: "Unmanned aerial vehicle" content: or both. The earliest recorded use of an unmanned aerial vehicle for warfighting occurred on July 1849, serving as a balloon carrier (the precursor to the aircraft carrier) in the first offensive use of air power in naval aviation. Austrian forces besieging Venice attempted to launch some 200 incendiary balloons at besieged city. The balloons were launched mainly from land, however some were also launched from the Austrian ship SMS Vulcano. At least one bomb fell in the city, however due to the wind changing after launch, most of the balloons missed their target and some drifted back over Austrian


title: "Unmanned aerial vehicle" content: lines and the launching ship "Vulcano". UAV innovations started in the early 1900s and originally focused on providing practice targets for training military personnel. UAV development continued during World War I, when the Dayton-Wright Airplane Company invented a pilotless aerial torpedo that would explode at a preset time. The earliest attempt at a powered UAV was A. M. Low's "Aerial Target" in 1916. Nikola Tesla described a fleet of unmanned aerial combat vehicles in 1915. Advances followed during and after World War I, including the Hewitt-Sperry Automatic Airplane. This developments also inspired the development of the Kettering Bug by Charles


title: "Unmanned aerial vehicle" content: Kettering from Dayton, Ohio. This was initially meant as an unmanned plane that would carry an explosive payload to a predetermined target. The first scaled remote piloted vehicle was developed by film star and model-airplane enthusiast Reginald Denny in 1935. More emerged during World War II used both to train antiaircraft gunners and to fly attack missions. Nazi Germany produced and used various UAV aircraft during the war. Jet engines entered service after World War II in vehicles such as the Australian GAF Jindivik, and Teledyne Ryan Firebee I of 1951, while companies like Beechcraft offered their Model 1001 for


title: "Unmanned aerial vehicle" content: the U.S. Navy in 1955. Nevertheless, they were little more than remote-controlled airplanes until the Vietnam War. In 1959, the U.S. Air Force, concerned about losing pilots over hostile territory, began planning for the use of unmanned aircraft. Planning intensified after the Soviet Union shot down a U-2 in 1960. Within days, a highly classified UAV program started under the code name of "Red Wagon". The August 1964 clash in the Tonkin Gulf between naval units of the U.S. and North Vietnamese Navy initiated America's highly classified UAVs (Ryan Model 147, Ryan AQM-91 Firefly, Lockheed D-21) into their first combat


title: "Unmanned aerial vehicle" content: missions of the Vietnam War. When the Chinese government showed photographs of downed U.S. UAVs via "Wide World Photos", the official U.S. response was "no comment". The War of Attrition (1967–1970) featured the introduction of UAVs with reconnaissance cameras into combat in the Middle East. In the 1973 Yom Kippur War, Israel used UAVs as decoys to spur opposing forces into wasting expensive anti-aircraft missiles. In 1973, the U.S. military officially confirmed that they had been using UAVs in Southeast Asia (Vietnam). Over 5,000 U.S. airmen had been killed and over 1,000 more were missing or captured. The USAF 100th


title: "Unmanned aerial vehicle" content: Strategic Reconnaissance Wing flew about 3,435 UAV missions during the war at a cost of about 554 UAVs lost to all causes. In the words of USAF General George S. Brown, Commander, Air Force Systems Command, in 1972, "The only reason we need (UAVs) is that we don't want to needlessly expend the man in the cockpit." Later that year, General John C. Meyer, Commander in Chief, Strategic Air Command, stated, "we let the drone do the high-risk flying ... the loss rate is high, but we are willing to risk more of them ... they save lives!" During the


title: "Unmanned aerial vehicle" content: 1973 Yom Kippur War, Soviet-supplied surface-to-air missile batteries in Egypt and Syria caused heavy damage to Israeli fighter jets. As a result, Israel developed the first UAV with real-time surveillance. The images and radar decoys provided by these UAVs helped Israel to completely neutralize the Syrian air defenses at the start of the 1982 Lebanon War, resulting in no pilots downed. The first time UAVs were used as proof-of-concept of super-agility post-stall controlled flight in combat-flight simulations involved tailless, stealth technology-based, three-dimensional thrust vectoring flight control, jet-steering UAVs in Israel in 1987. With the maturing and miniaturization of applicable technologies


title: "Unmanned aerial vehicle" content: in the 1980s and 1990s, interest in UAVs grew within the higher echelons of the U.S. military. In the 1990s, the U.S. DoD gave a contract to AAI Corporation along with Israeli company Malat. The U.S. Navy bought the AAI Pioneer UAV that AAI and Malat developed jointly. Many of these UAVs saw service in the 1991 Gulf War. UAVs demonstrated the possibility of cheaper, more capable fighting machines, deployable without risk to aircrews. Initial generations primarily involved surveillance aircraft, but some carried armaments, such as the General Atomics MQ-1 Predator, that launched AGM-114 Hellfire air-to-ground missiles. CAPECON was a


title: "Unmanned aerial vehicle" content: European Union project to develop UAVs, running from 1 May 2002 to 31 December 2005. As of 2012, the USAF employed 7,494 UAVs almost one in three USAF aircraft. The Central Intelligence Agency also operated UAVs. In 2013 at least 50 countries used UAVs. China, Iran, Israel, Pakistan, and others designed and built their own varieties. UAVs typically fall into one of six functional categories (although multi-role airframe platforms are becoming more prevalent): The U.S. Military UAV tier system is used by military planners to designate the various individual aircraft elements in an overall usage plan. Vehicles can be categorised


title: "Unmanned aerial vehicle" content: in terms of range/altitude. The following has been advanced as relevant at industry events such as ParcAberporth Unmanned Systems forum: Other categories include: Classifications according to aircraft weight are quite simpler: Manned and unmanned aircraft of the same type generally have recognizably similar physical components. The main exceptions are the cockpit and environmental control system or life support systems. Some UAVs carry payloads (such as a camera) that weigh considerably less than an adult human, and as a result can be considerably smaller. Though they carry heavy payloads, weaponized military UAVs are lighter than their manned counterparts with comparable armaments.


title: "Unmanned aerial vehicle" content: Small civilian UAVs have no life-critical systems, and can thus be built out of lighter but less sturdy materials and shapes, and can use less robustly tested electronic control systems. For small UAVs, the quadcopter design has become popular, though this layout is rarely used for manned aircraft. Miniaturization means that less-powerful propulsion technologies can be used that are not feasible for manned aircraft, such as small electric motors and batteries. Control systems for UAVs are often different than manned craft. For remote human control, a camera and video link almost always replace the cockpit windows; radio-transmitted digital commands replace


title: "Unmanned aerial vehicle" content: physical cockpit controls. Autopilot software is used on both manned and unmanned aircraft, with varying feature sets. The primary difference for planes is the absence of the cockpit area and its windows. Tailless quadcopters are a common form factor for rotary wing UAVs while tailed mono- and bi-copters are common for manned platforms. Small UAVs mostly use lithium-polymer batteries (Li-Po), while larger vehicles rely on conventional airplane engines. Scale or size of aircraft is not the defining or limiting characteristic of energy supply for a UAV. At present, the energy density of Li-Po is far less than gasoline. The record


title: "Unmanned aerial vehicle" content: of travel for a UAV (built from balsa wood and mylar skin) across the North Atlantic Ocean is held by a gasoline model airplane or UAV. Manard Hill in "in 2003 when one of his creations flew 1,882 miles across the Atlantic Ocean on less than a gallon of fuel" holds this record. See: Electric power is used as less work is required for a flight and electric motors are quieter. Also, properly designed, the thrust to weight ratio for an electric or gasoline motor driving a propeller can hover or climb vertically. Botmite airplane is an example of an


title: "Unmanned aerial vehicle" content: electric UAV which can climb vertically. Battery elimination circuitry (BEC) is used to centralize power distribution and often harbors a microcontroller unit (MCU). Costlier switching BECs diminish heating on the platform. UAV computing capability followed the advances of computing technology, beginning with analog controls and evolving into microcontrollers, then system-on-a-chip (SOC) and single-board computers (SBC). System hardware for small UAVs is often called the flight controller (FC), flight controller board (FCB) or autopilot. Position and movement sensors give information about the aircraft state. Exteroceptive sensors deal with external information like distance measurements, while exproprioceptive ones correlate internal and external states.


title: "Unmanned aerial vehicle" content: Non-cooperative sensors are able to detect targets autonomously so they are used for separation assurance and collision avoidance. Degrees of freedom (DOF) refers to both the amount and quality of sensors on-board: 6 DOF implies 3-axis gyroscopes and accelerometers (a typical inertial measurement unit IMU), 9 DOF refers to an IMU plus a compass, 10 DOF adds a barometer and 11 DOF usually adds a GPS receiver. UAV actuators include digital electronic speed controllers (which control the RPM of the motors) linked to motors/engines and propellers, servomotors (for planes and helicopters mostly), weapons, payload actuators, LEDs and speakers. UAV software


title: "Unmanned aerial vehicle" content: called the flight stack or autopilot. UAVs are real-time systems that require rapid response to changing sensor data. Examples include Raspberry Pis, Beagleboards, etc. shielded with NavIO, PXFMini, etc. or designed from scratch such as Nuttx, preemptive-RT Linux, Xenomai, Orocos-Robot Operating System or DDS-ROS 2.0. Civil-use open-source stacks include: UAVs employ open-loop, closed-loop or hybrid control architectures. UAVs can be programmed to perform aggressive manœuvres or landing/perching on inclined surfaces, and then to climb toward better communication spots. Some UAVs can control flight with varying flight modelisation, such as VTOL designs. UAVs can also implement perching on a flat vertical


title: "Unmanned aerial vehicle" content: surface. Most UAVs use a radio for remote control and exchange of video and other data. Early UAVs had only narrowband uplink. Downlinks came later. These bi-directional narrowband radio links carried command and control (C&C) and telemetry data about the status of aircraft systems to the remote operator. For very long range flights, military UAVs also use satellite receivers as part of satellite navigation systems. In cases when video transmission was required, the UAVs will implement a separate analog video radio link. In the most modern UAV applications, video transmission is required. So instead of having 2 separate links for


title: "Unmanned aerial vehicle" content: C&C, telemetry and video traffic, a broadband link is used to carry all types of data on the a single radio link. These broadband links can leverage quality of service techniques to optimize the C&C traffic for low latency. Usually these broadband links carry TCP/IP traffic that can be routed over the Internet. The radio signal from the operator side can be issued from either: ICAO classifies unmanned aircraft as either remotely piloted aircraft or fully autonomous. Actual UAVs may offer intermediate degrees of autonomy. E.g., a vehicle that is remotely piloted in most contexts may have an autonomous return-to-base


title: "Unmanned aerial vehicle" content: operation. Basic autonomy comes from proprioceptive sensors. Advanced autonomy calls for situational awareness, knowledge about the environment surrounding the aircraft from exterioceptive sensors: sensor fusion integrates information from multiple sensors. One way to achieve autonomous control employs multiple control-loop layers, as in hierarchical control systems. As of 2016 the low-layer loops (i.e. for flight control) tick as fast as 32,000 times per second, while higher-level loops may cycle once per second. The principle is to decompose the aircraft's behavior into manageable "chunks", or states, with known transitions. Hierarchical control system types range from simple scripts to finite state machines, behavior


title: "Unmanned aerial vehicle" content: trees and hierarchical task planners. The most common control mechanism used in these layers is the PID controller which can be used to achieve hover for a quadcopter by using data from the IMU to calculate precise inputs for the electronic speed controllers and motors. Examples of mid-layer algorithms: Evolved UAV hierarchical task planners use methods like state tree searches or genetic algorithms. UAV manufacturers often build in specific autonomous operations, such as: Full autonomy is available for specific tasks, such as airborne refueling or ground-based battery switching; but higher-level tasks call for greater computing, sensing and actuating capabilities. One


title: "Unmanned aerial vehicle" content: approach to quantifying autonomous capabilities is based on OODA terminology, as suggested by a 2002 US Air Force Research Laboratory, and used in the table below: Reactive autonomy, such as collective flight, real-time collision avoidance, wall following and corridor centring, relies on telecommunication and situational awareness provided by range sensors: optic flow, lidars (light radars), radars, sonars. Most range sensors analyze electromagnetic radiation, reflected off the environment and coming to the sensor. The cameras (for visual flow) act as simple receivers. Lidars, radars and sonars (with sound mechanical waves) emit and receive waves, measuring the round-trip transit time. UAV cameras


title: "Unmanned aerial vehicle" content: do not require emitting power, reducing total consumption. Radars and sonars are mostly used for military applications. Reactive autonomy has in some forms already reached consumer markets: it may be widely available in less than a decade. SLAM combines odometry and external data to represent the world and the position of the UAV in it in three dimensions. High-altitude outdoor navigation does not require large vertical fields-of-view and can rely on GPS coordinates (which makes it simple mapping rather than SLAM). Two related research fields are photogrammetry and LIDAR, especially in low-altitude and indoor 3D environments. Robot swarming refers to


title: "Unmanned aerial vehicle" content: networks of agents able to dynamically reconfigure as elements leave or enter the network. They provide greater flexibility than multi-agent cooperation. Swarming may open the path to data fusion. Some bio-inspired flight swarms use steering behaviors and flocking. In the military sector, American Predators and Reapers are made for counterterrorism operations and in war zones in which the enemy lacks sufficient firepower to shoot them down. They are not designed to withstand antiaircraft defenses or air-to-air combat. In September 2013, the chief of the US Air Combat Command stated that current UAVs were "useless in a contested environment" unless manned


title: "Unmanned aerial vehicle" content: aircraft were there to protect them.[167] A 2012 Congressional Research Service (CRS) report speculated that in the future, UAVs may be able to perform tasks beyond intelligence, surveillance, reconnaissance and strikes; the CRS report listed air-to-air combat ("a more difficult future task") as possible future undertakings.[168] The Department of Defense's Unmanned Systems Integrated Roadmap FY2013-2038 foresees a more important place for UAVs in combat.[169] Issues include extended capabilities, human-UAV interaction, managing increased information flux, increased autonomy and developing UAV-specific munitions.[169] DARPA's project of systems of systems, or General Atomics work may augur future warfare scenarios, the latter disclosing Avenger swarms


title: "Unmanned aerial vehicle" content: equipped with High Energy Liquid Laser Area Defense System (HELLADS). Cognitive radio technology may have UAV applications. UAVs may exploit distributed neural networks. The global military UAV market is dominated by companies based in the United States and Israel. By sale numbers, The US held over 60% military-market share in 2017. Four of top five military UAV manufactures are American including General Atomics, Lockheed Martin, Northrop Grumman and Boeing, followed by the Chinese company CASC. Israel companies mainly focus on small surveillance UAV system and by quantity of drones, Israel exported 60.7% (2014) of UAV on the market while the


title: "Unmanned aerial vehicle" content: United States export 23.9% (2014); top importers of military UAV are The United Kingdom (33.9%) and India (13.2%). United States alone operated over 9,000 military UAVs in 2014. General Atomics is the dominant manufacturer with the Global Hawk and Predator/Mariner systems product-line. The civilian drone market is dominated by Chinese companies. Chinese drone manufacturer DJI alone has 75% of civilian-market share in 2017 with $11 billion forecast global sales in 2020. Followed by French company Parrot with $110m and US company 3DRobotics with $21.6m in 2014. As of March 2018, more than one million UAVs (878,000 hobbyist and 122,000 commercial)


title: "Unmanned aerial vehicle" content: were registered with the U.S. FAA. 2018 NPD point to consumers increasingly purchasing drones with more advanced features with 33 percent growth in both the $500+ and $1000+ market segments. Civilian UAV market is relatively new compared to military. Companies are emerging in both developed and developing nations at the same time. Many early stage startups have received support and funding from investors like in United States and by government agencies as the case in India. Some universities offer research and training programs or degrees. Private entities also provide online and in-person training programs for both recreational and commercial UAV


title: "Unmanned aerial vehicle" content: use. Consumer drones are also widely used by military organizations worldwide because of the cost-effective nature of consumer product. In 2018, Israeli military started to use DJI Mavic and Matrice series of UAV for light reconnaissance mission since the civilian drones are easier to use and have higher reliability. DJI drones is also the most widely used commercial unmanned aerial system that the US Army has employed. Lighted drones are beginning to be used in nighttime displays for artistic and advertising purposes. The AIA reports large cargo and passengers drones should be certified and introduced over the next 20 years.


title: "Unmanned aerial vehicle" content: Sensor-carrying large drones are expected from 2018; short-haul, low altitude freighters outside cities from 2025; long-haul cargo flights by the mid-2030s and then passenger flights by 2040. Spending should rise from a few hundred million dollars on research and development in 2018 to $4 billion by 2028 and $30 billion by 2036. Flapping-wing ornithopters, imitating birds or insects, are a research field in microUAVs. Their inherent stealth recommends them for spy missions. The Nano Hummingbird is commercially available, while sub-1g microUAVs inspired by flies, albeit using a power tether, can "land" on vertical surfaces. Other projects include unmanned "beetles" and


title: "Unmanned aerial vehicle" content: other insects. Research is exploring miniature optic-flow sensors, called ocellis, mimicking the compound insect eyes formed from multiple facets, which can transmit data to neuromorphic chips able to treat optic flow as well as light intensity discrepancies. UAV endurance is not constrained by the physiological capabilities of a human pilot. Because of their small size, low weight, low vibration and high power to weight ratio, Wankel rotary engines are used in many large UAVs. Their engine rotors cannot seize; the engine is not susceptible to shock-cooling during descent and it does not require an enriched fuel mixture for cooling at


title: "Unmanned aerial vehicle" content: high power. These attributes reduce fuel usage, increasing range or payload. Proper drone cooling is essential for long-term drone endurance. Overheating and subsequent engine failure is the most common cause of drone failure. Hydrogen fuel cells, using hydrogen power, may be able to extend the endurance of small UAVs, up to several hours. Micro air vehicles endurance is so far best achieved with flapping-wing UAVs, followed by planes and multirotors standing last, due to lower Reynolds number. Solar-electric UAVs, a concept originally championed by the AstroFlight Sunrise in 1974, have achieved flight times of several weeks. Solar-powered atmospheric satellites ("atmosats")