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Airborne Wind Turbine
An airborne wind turbine is a design concept for a wind turbine with a rotor supported in the air without a tower, thus benefiting from the higher velocity and persistence of wind at high altitudes, while avoiding the expense of tower construction, or the need for slip rings or yaw mechanism. An electrical generator may be on the ground or airborne. Challenges include safely suspending and maintaining turbines hundreds of meters off the ground in high winds and storms, transferring the harvested and/or generated power back to earth, and interference with aviation. Airborne wind turbines may operate in low or high altitudes; they are part of a wider class of Airborne Wind Energy Systems (AWES) addressed by high-altitude wind power and crosswind kite power. When the generator is on the ground, then the tethered aircraft need not carry the generator mass or have a conductive tether. When the generator is aloft, then a conductive tether would be used to transmit energy to the ground ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
KiteGen
KiteGen is a concept for a wind harnessing machine for high altitude winds, developed in Italy. The vertical axis rotation is intended to eliminate the static and dynamic problems that limit the size of conventional wind turbines. The prototype STEM yo-yo is under construction at Berzano di San Pietro in Italy. History The KiteGen was originally conceived by Italian researcher Massimo Ippolito. While observing kite surfers, he noticed the large amount of energy that the kite could collect and thought that a similar system could produce electricity. This idea seemed to Ippolito so risky that he put it aside for years. Structure The problem of capturing the wind is solved by the use of Power Wing Profiles (Power kites) whose movements are controlled automatically by a computer. The kites are tied by cables to a structure that rotates, generating electricity. This structure is the turbine, while the kites are the "blades". The kites are flown on a predetermined trajectory, tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The News & Advance
''The News & Advance'' is the daily newspaper of record in Lynchburg, Virginia, United States. Its primary circulation area consists of the city of Lynchburg and the surrounding counties of Amherst, Appomattox, Bedford, and Campbell. ''The News & Advance'' is owned by Lee Enterprises. Alton Brown is the publisher. Caroline Glickman is the managing editor. The newspaper uses articles from news services, such as the Associated Press, as well as former Media General-owned news organizations. ''The News & Advance'' added a new printing press in 2009, manufactured by Koenig & Bauer. Its last press was built in 1974, when the newspaper moved to its current building. Prior to 1974, the newspaper's headquarters were in downtown Lynchburg. History ''The News'' was founded on January 15, 1866, as a morning newspaper, while ''The Daily Advance'' was founded in 1880, as an evening newspaper. In 1888, future U. S. Senator Carter Glass bought ''The News''. In 1893, he bought ''The Daily ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helium
Helium (from el, ἥλιος, helios, lit=sun) is a chemical element with the symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas and the first in the noble gas group in the periodic table. Its boiling and melting point are the lowest among all the elements. It is the second lightest and second most abundant element in the observable universe ( hydrogen is the lightest and most abundant). It is present at about 24% of the total elemental mass, which is more than 12 times the mass of all the heavier elements combined. Its abundance is similar to this in both the Sun and in Jupiter, due to the very high nuclear binding energy (per nucleon) of helium-4, with respect to the next three elements after helium. This helium-4 binding energy also accounts for why it is a product of both nuclear fusion and radioactive decay. The most common isotope of helium in the universe is helium-4, the vast majority of which was forme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ontario
Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and politically been considered to be part of Central Canada. Located in Central Canada, it is Canada's most populous province, with 38.3 percent of the country's population, and is the second-largest province by total area (after Quebec). Ontario is Canada's fourth-largest jurisdiction in total area when the territories of the Northwest Territories and Nunavut are included. It is home to the nation's capital city, Ottawa, and the nation's most populous city, Toronto, which is Ontario's provincial capital. Ontario is bordered by the province of Manitoba to the west, Hudson Bay and James Bay to the north, and Quebec to the east and northeast, and to the south by the U.S. states of (from west to east) Minnesota, Michigan, Ohio, Pennsylvania, and New York. Almost all of Ontario's border with the United St ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Balloon
A solar balloon is a balloon that gains buoyancy when the air inside is heated by solar radiation, usually with the help of black or dark balloon material. The heated air inside the solar balloon expands and has lower density than the surrounding air. As such, a solar balloon is similar to a hot air balloon. Usage of solar balloons is predominantly in the toy market, although it has been proposed that they be used in the investigation of planet Mars, and some solar balloons are large enough for human flight. A vent at the top can be opened to release hot air for descent and deflation. Theory of operation Generating lift Raising the air temperature inside the envelope makes it less dense than the surrounding (ambient) air. The balloon floats because of the buoyant force exerted on it. This force is the same force that acts on objects when they are in water and is described by Archimedes' principle. The amount of lift (or buoyancy) provided by a hot air balloon depends primarily ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerostat
An aerostat (, via French) is a lighter-than-air aircraft that gains its lift through the use of a buoyant gas. Aerostats include unpowered balloons and powered airships. A balloon may be free-flying or tethered. The average density of the craft is lower than the density of atmospheric air, because its main component is one or more gasbags, a lightweight skin containing a lifting gas (which could be heated air or any gas of lower density than air) to provide buoyancy, to which other components such as a gondola containing equipment or people are attached. Especially with airships, the gasbags are often protected by an outer envelope. Aerostats are so named because they use aerostatic lift which is a buoyant force that does not require movement through the surrounding air mass, resulting in VTOL ability. This contrasts with the heavy aerodynes that primarily use aerodynamic lift which requires the movement of a wing surface through the surrounding air mass. The term has a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Domina Jalbert
Domina Cleophas Jalbert (1904–1991) invented the ram-air inflated flexible wing, often called the "Jalbert parafoil". Personal life Domina Jalbert was born in Saint-Jean-de-Matha, Quebec, Canada; his father was Onesime Jalbert (1856–1938) and his mother was Celestine Gouger (1861–1939). He was one of 17 children. Early in his life he moved to Woonsocket, Rhode Island, where he lived and worked for many years before moving to Boca Raton, Florida, in his older years. While living in Woonsocket, Jalbert graduated from Woonsocket High School, and later worked as a track coach and administrator for Mount St. Charles Academy. Jalbert received a U.S. pilots' license in 1927. In the 1930s he was active in kiting, using large kites for advertising purposes. He was hired to help protect the coastline of the western United States during war with the design and making of barrage balloons; he worked for the United States Rubber Company in Naugatuck, Connecticut, USA. Jalbert la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lift-to-drag Ratio
In aerodynamics, the lift-to-drag ratio (or L/D ratio) is the lift generated by an aerodynamic body such as an aerofoil or aircraft, divided by the aerodynamic drag caused by moving through air. It describes the aerodynamic efficiency under given flight conditions. The L/D ratio for any given body will vary according to these flight conditions. For an aerofoil wing or powered aircraft, the L/D is specified when in straight and level flight. For a glider it determines the glide ratio, of distance travelled against loss of height. The term is calculated for any particular airspeed by measuring the lift generated, then dividing by the drag at that speed. These vary with speed, so the results are typically plotted on a 2-dimensional graph. In almost all cases the graph forms a U-shape, due to the two main components of drag. The L/D may be calculated using computational fluid dynamics or computer simulation. It is measured empirically by testing in a wind tunnel or in free fligh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buoyancy
Buoyancy (), or upthrust, is an upward force exerted by a fluid that opposes the weight of a partially or fully immersed object. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus the pressure at the bottom of a column of fluid is greater than at the top of the column. Similarly, the pressure at the bottom of an object submerged in a fluid is greater than at the top of the object. The pressure difference results in a net upward force on the object. The magnitude of the force is proportional to the pressure difference, and (as explained by Archimedes' principle) is equivalent to the weight of the fluid that would otherwise occupy the submerged volume of the object, i.e. the displaced fluid. For this reason, an object whose average density is greater than that of the fluid in which it is submerged tends to sink. If the object is less dense than the liquid, the force can keep the object afloat. This can occur only in a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teknisk Ukeblad
''Teknisk Ukeblad'' (''TU'', en, Technical Weekly Magazine) is a Norwegian engineering magazine. The magazine has its headquarters in Oslo, Norway. History and profile ''TU'' has appeared weekly since 13 April 1883 and was published by Ingeniørforlaget, now Teknisk Ukeblad Media jointly owned by three national professional associations of engineers and architects: the Norwegian Society of Engineers and Technologists (NITO, founded 1936), Tekna (founded in 1874), and the Norwegian Polytechnic Society (PF, founded 1852). On 24 June 2010 ''TU'' had a total circulation of 302,000 weekly copies. Corresponding publications are '' Ny Teknik'' in Sweden, '' Ingeniøren'' in Denmark and ''Technisch Weekblad'' in the Netherlands. References External links Teknisk Ukeblad the magazine's websiteTeknisk Ukeblad some older volumes digitized by Project Runeberg Project Runeberg ( sv, Projekt Runeberg) is a digital cultural archive initiative that publishes free electronic versions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
