1.
Saab Group
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Saab Group is a Swedish aerospace and defence company, founded in 1937. From 1947 to 1990 it was the parent company of automobile manufacturer Saab Automobile, between 1968 and 1995 the company was in a merger with commercial vehicle manufacturer Scania-Vabis, known as Saab-Scania. The two were de-merged in 1995 by the new owners, Investor AB, despite the demerger, both Saab and Scania share the right to use the griffin logo, which originates from the coat of arms of the Swedish region of Scania. Svenska Aeroplan AB was founded in 1937 in Trollhättan, with the merger of Svenska Aero AB, the style Saab replaced SAAB around 1950. Originally manufacturing aircraft, the company sought ways in which to diversify its business, in the late 1940s the company began manufacturing cars at its Saab Automobile division, based in Trollhättan. The first car was the Saab 92, full-scale production started December 12,1949, in the late 1950s Saab ventured into the computer market with Datasaab. The company was a partly of the need to make a computer that would be small enough to mount in an aeroplane as navigational equipment. During the 1960s several computers were developed and sold to European countries, the aircraft computer was used in 1971 in the Viggen. The company was sold in 1975 to Sperry UNIVAC, while Saab retained its flight computer development, in May 1965, the company name was changed to Saab AB to reflect its broad range of activities. In 1968 Saab AB merged with the Swedish lorry, bus and heavy-duty diesel engine manufacturer Scania-Vabis, in 1990 General Motors bought 51 percent of the car division Saab Automobile, and acquired the rest a decade later. In 1991 Investor AB completed a buyout of Saab-Scania AB. Investor AB acquired all the shares in Saab-Scania for approximately SEK21 billion. Saab-Scania became a wholly owned subsidiary of Investor AB and the company was de-listed, in 1995 Saab-Scania was divided by Investor AB into two independent companies, de-merging into Scania AB and Saab AB. The intention by Investor AB was to broaden ownership in the two companies later, following the sale of 50% of the car division Saab Automobile AB to General Motors, the main reason behind the merger with lorry manufacturer Scania-Vabis in 1968 had disappeared. Saab Military Aircraft and British Aerospace formed in 1995 the joint venture company Saab-BAe Gripen AB, to manufacture, market and this co-operation was extended in 2001 with the formation of Gripen International for the same purpose. From 1998 until 2005 the largest shareholder in Saab was the British aerospace company BAE Systems, following its acquisition of a 35% stake from Investor AB by its predecessor, in January 2005, BAE Systems reduced its shareholding to 20%. Investor AB maintained a 20% share,16 November 1999, Saab announced its intention is to purchase Celsius AB and the acquisition was concluded by early March 2000. In December 2005 Saab joined the Dassault nEUROn project as a major partner, in October 2008 the company announced its intention to merge its operations with that of Simrad Optronics
2.
Sweden
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Sweden, officially the Kingdom of Sweden, is a Scandinavian country in Northern Europe. It borders Norway to the west and Finland to the east, at 450,295 square kilometres, Sweden is the third-largest country in the European Union by area, with a total population of 10.0 million. Sweden consequently has a low density of 22 inhabitants per square kilometre. Approximately 85% of the lives in urban areas. Germanic peoples have inhabited Sweden since prehistoric times, emerging into history as the Geats/Götar and Swedes/Svear, Southern Sweden is predominantly agricultural, while the north is heavily forested. Sweden is part of the area of Fennoscandia. The climate is in very mild for its northerly latitude due to significant maritime influence. Today, Sweden is a monarchy and parliamentary democracy, with a monarch as head of state. The capital city is Stockholm, which is also the most populous city in the country, legislative power is vested in the 349-member unicameral Riksdag. Executive power is exercised by the government chaired by the prime minister, Sweden is a unitary state, currently divided into 21 counties and 290 municipalities. Sweden emerged as an independent and unified country during the Middle Ages, in the 17th century, it expanded its territories to form the Swedish Empire, which became one of the great powers of Europe until the early 18th century. Swedish territories outside the Scandinavian Peninsula were gradually lost during the 18th and 19th centuries, the last war in which Sweden was directly involved was in 1814, when Norway was militarily forced into personal union. Since then, Sweden has been at peace, maintaining a policy of neutrality in foreign affairs. The union with Norway was peacefully dissolved in 1905, leading to Swedens current borders, though Sweden was formally neutral through both world wars, Sweden engaged in humanitarian efforts, such as taking in refugees from German-occupied Europe. After the end of the Cold War, Sweden joined the European Union on 1 January 1995 and it is also a member of the United Nations, the Nordic Council, Council of Europe, the World Trade Organization and the Organisation for Economic Co-operation and Development. Sweden maintains a Nordic social welfare system that provides health care. The modern name Sweden is derived through back-formation from Old English Swēoþēod and this word is derived from Sweon/Sweonas. The Swedish name Sverige literally means Realm of the Swedes, excluding the Geats in Götaland, the etymology of Swedes, and thus Sweden, is generally not agreed upon but may derive from Proto-Germanic Swihoniz meaning ones own, referring to ones own Germanic tribe
3.
Vacuum tube
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In electronics, a vacuum tube, an electron tube, or just a tube, or valve, is a device that controls electric current between electrodes in an evacuated container. Vacuum tubes mostly rely on thermionic emission of electrons from a hot filament or a cathode heated by the filament and this type is called a thermionic tube or thermionic valve. A phototube, however, achieves electron emission through the photoelectric effect, the simplest vacuum tube, the diode, contains only a heater, a heated electron-emitting cathode, and a plate. Current can only flow in one direction through the device between the two electrodes, as electrons emitted by the travel through the tube and are collected by the anode. Adding one or more control grids within the tube allows the current between the cathode and anode to be controlled by the voltage on the grid or grids, Tubes with grids can be used for many purposes, including amplification, rectification, switching, oscillation, and display. In the 1940s the invention of devices made it possible to produce solid-state devices, which are smaller, more efficient, more reliable, more durable. Hence, from the mid-1950s solid-state devices such as transistors gradually replaced tubes, the cathode-ray tube remained the basis for televisions and video monitors until superseded in the 21st century. However, there are still a few applications for which tubes are preferred to semiconductors, for example, the used in microwave ovens. One classification of vacuum tubes is by the number of active electrodes, a device with two active elements is a diode, usually used for rectification. Devices with three elements are used for amplification and switching. Additional electrodes create tetrodes, pentodes, and so forth, which have additional functions made possible by the additional controllable electrodes. X-ray tubes are vacuum tubes. Phototubes and photomultipliers rely on electron flow through a vacuum, though in those cases electron emission from the cathode depends on energy from photons rather than thermionic emission, since these sorts of vacuum tubes have functions other than electronic amplification and rectification they are described in their own articles. A vacuum tube consists of two or more electrodes in a vacuum inside an airtight enclosure, most tubes have glass envelopes, though ceramic and metal envelopes have been used. The electrodes are attached to leads which pass through the envelope via an airtight seal, Tubes were a frequent cause of failure in electronic equipment, and consumers were expected to be able to replace tubes themselves. In addition to the terminals, some tubes had an electrode terminating at a top cap. The principal reason for doing this was to avoid leakage resistance through the tube base, the bases were commonly made with phenolic insulation which performs poorly as an insulator in humid conditions. There was even a design that had two top cap connections
4.
Saab 37 Viggen
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The Saab 37 Viggen is a Swedish single-seat, single-engine, short-medium range combat aircraft. The Viggen holds the distinction of being the first canard design to be produced in quantity, several distinctive variants of the Viggen were produced to perform the roles of strike fighter, aerial reconnaissance, maritime patrol aircraft and a two-seat trainer. In the late 1970s, the all-weather fighter-interceptor aircraft JA37 variant was introduced, in November 2005, the Viggen was retired from service by the Swedish Air Force, the sole operator of the type, having been replaced by the newer Saab JAS39 Gripen. The Viggen was initially developed as a replacement for the Saab 32 Lansen in the attack role. Between 1952 and 1957, the first studies towards what would become the Viggen were carried out, over 100 different concepts were examined in these studies, involving both single- and twin engine configurations, both traditional and double delta wings, and canard wings. Even VTOL designs were considered, with separate lift engines, but were identified as being unacceptable. From the onset, the Viggen was planned as a weapon system, to be operated in conjunction with the newest revision of Swedens national electronic air defense system. It was used as the standard platform, capable of being efficiently adapted to perform all tactical mission roles. Other requirements included supersonic ability at low level, Mach 2 performance at altitude, the aircraft was also designed from the beginning to be easy to repair and service, even for personnel without much training. However, Bruzelius theory has been discredited by Simon Moores and Jerker Widén, in December 1961, the Swedish government gave its approval for the development of Aircraft System 37, which would ultimately become the Viggen. In February 1962, approval of the configuration was given and was followed by a development contract in October 1962. According to aviation authors Bill Gunston and Peter Gilchrist, the project was by far the largest industrial development task ever attempted in Sweden, during the 1960s, the Viggen accounted for 10 per cent of all Swedish R&D funding. The use of a thrust reverser enabled the sought short landing performance, during development, Saab had opted to power the type using a single large turbofan engine. In place of the Medway, Saab chose to adopt a version of the American Pratt & Whitney JT8D engine. The RM8 was heavily redesigned, using new materials to accommodate flight at Mach-2 speeds, a Swedish-built afterburner, and a fully variable nozzle. This first flight, which lasted for 43 minutes, was flown by Erik Dahlström, Saabs chief test pilot, writing at the time, aerospace publication Flight International described the flight as having been Swedens astonishing unilateral stand in the front rank of advanced aircraft-building nations. Each of the seven prototypes were assigned different roles, although the aircraft were focused on supporting the development of the initial production variant. In 1967, the Swedish Government concluded that the in-development AJ37 Viggen would be cheaper and superior to the McDonnell Douglas F-4 Phantom II
5.
Airplane
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An airplane or aeroplane is a powered, fixed-wing aircraft that is propelled forward by thrust from a jet engine or propeller. Airplanes come in a variety of sizes, shapes, and wing configurations, the broad spectrum of uses for airplanes includes recreation, transportation of goods and people, military, and research. Commercial aviation is a massive industry involving the flying of tens of thousands of daily on airliners. Most airplanes are flown by a pilot on board the aircraft, the Wright brothers invented and flew the first airplane in 1903, recognized as the first sustained and controlled heavier-than-air powered flight. They built on the works of George Cayley dating from 1799, between 1867 and 1896, the German pioneer of human aviation Otto Lilienthal also studied heavier-than-air flight. Following its limited use in World War I, aircraft continued to develop. Airplanes had a presence in all the battles of World War II. The first jet aircraft was the German Heinkel He 178 in 1939, the first jet airliner, the de Havilland Comet, was introduced in 1952. The Boeing 707, the first widely successful commercial jet, was in service for more than 50 years. Aéroplane originally referred just to the wing, as it is a plane moving through the air, in an example of synecdoche, the word for the wing came to refer to the entire aircraft. In the United States and Canada, the airplane is used for powered fixed-wing aircraft. In the United Kingdom and most of the Commonwealth, the aeroplane is usually applied to these aircraft. Many stories from antiquity involve flight, such as the Greek legend of Icarus and Daedalus, and this machine may have been suspended for its flight. Some of the earliest recorded attempts with gliders were those by the 9th-century poet Abbas ibn Firnas, leonardo da Vinci researched the wing design of birds and designed a man-powered aircraft in his Codex on the Flight of Birds. In 1799, George Cayley set forth the concept of the airplane as a fixed-wing flying machine with separate systems for lift, propulsion. Cayley was building and flying models of fixed-wing aircraft as early as 1803, in 1856, Frenchman Jean-Marie Le Bris made the first powered flight, by having his glider LAlbatros artificiel pulled by a horse on a beach. Then Alexander F. Mozhaisky also made some innovative designs, in 1883, the American John J. Montgomery made a controlled flight in a glider. Other aviators who made similar flights at that time were Otto Lilienthal, Percy Pilcher, sir Hiram Maxim built a craft that weighed 3.5 tons, with a 110-foot wingspan that was powered by two 360-horsepower steam engines driving two propellers
