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Volcanic Ash And Aviation Safety
Plumes of volcanic ash near active volcanoes are a flight safety hazard, especially for night flights. Volcanic ash is hard and abrasive, and can quickly cause significant wear to propellers and turbocompressor blades, and scratch cockpit windows, impairing visibility. The ash contaminates fuel and water systems, can jam gears, and make engines flame out. Its particles have low melting points, so they melt in the engines' combustion chamber then the ceramic mass sticks to turbine blades, fuel nozzles, and combustors—which can lead to total engine failure. Ash can also contaminate the cabin and damage avionics. In 1991, the aviation industry decided to set up Volcanic Ash Advisory Centers (VAACs) for liaison between meteorologists, volcanologists, and the aviation industry. Before 2010, aircraft engine manufacturers had not defined specific particle levels above which they considered engines at risk. Airspace regulators took the general approach that if ash concentration rose ab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eyjafjallajökull 17-4-2010
Eyjafjallajökull (; ), sometimes referred to by the numeronym E15, is one of the smaller ice caps of Iceland, north of Skógar and west of Mýrdalsjökull. The ice cap covers the caldera of a volcano with a summit elevation of . The volcano has erupted relatively frequently since the Last Glacial Period, most recently in 2010, when, although relatively small for a volcanic eruption, it caused enormous disruption to air travel across northern and western Europe for a week. Geography Eyjafjallajökull consists of a volcano completely covered by an ice cap. The ice cap covers an area of about , feeding many outlet glaciers. The main outlet glaciers are to the north: Gígjökull , flowing into Lónið , and Steinholtsjökull , flowing into Steinholtslón . In 1967, there was a massive landslide on the Steinholtsjökull glacial tongue. On 16 January 1967 at 13:47:55 there was an explosion on the glacier. It can be timed because the seismometers at Kirkjubæjarklaustur monitor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Civil Aviation Authority (United Kingdom)
The Civil Aviation Authority (CAA) is the statutory corporation which oversees and regulates all aspects of civil aviation in the United Kingdom. Its areas of responsibility include: * Supervising the issuing of pilots' licences, testing of equipment, calibrating of navaids, and many other inspections (Civil Aviation Flying Unit). * Managing the regulation of security standards, including vetting of all personnel in the aviation industry (Directorate of Aviation Security). * Overseeing the national protection scheme for customers abroad in the event of a travel company failure (Air Travel Organisers' Licensing – ATOL). The CAA is a public corporation of the Department for Transport, liaising with the government via the Standards Group of the Cabinet Office. Responsibilities The CAA directly or indirectly regulates all aspects of aviation in the UK. In some aspects of aviation it is the primary regulator. The UK government requires that the CAA's costs are met entirely fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erosion
Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distinct from weathering which involves no movement. Removal of rock or soil as clastic sediment is referred to as ''physical'' or ''mechanical'' erosion; this contrasts with ''chemical'' erosion, where soil or rock material is removed from an area by dissolution. Eroded sediment or solutes may be transported just a few millimetres, or for thousands of kilometres. Agents of erosion include rainfall; bedrock wear in rivers; coastal erosion by the sea and waves; glacial plucking, abrasion, and scour; areal flooding; wind abrasion; groundwater processes; and mass movement processes in steep landscapes like landslides and debris flows. The rates at which such processes act control how fast a surface is eroded. Typically, physical erosion procee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gas Compressor
A compressor is a mechanical device that increases the pressure of a gas by reducing its volume. An air compressor is a specific type of gas compressor. Compressors are similar to pumps: both increase the pressure on a fluid and both can transport the fluid through a pipe. The main distinction is that the focus of a compressor is to change the density or volume of the fluid, which is mostly only achievable on gases. Gases are compressible, while liquids are relatively incompressible, so compressors are rarely used for liquids. The main action of a pump is to pressurize and transport liquids. Many compressors can be staged, that is, the fluid is compressed several times in steps or stages, to increase discharge pressure. Often, the second stage is physically smaller than the primary stage, to accommodate the already compressed gas without reducing its pressure. Each stage further compresses the gas and increases its pressure and also temperature (if inter cooling between stages i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turbine
A turbine ( or ) (from the Greek , ''tyrbē'', or Latin ''turbo'', meaning vortex) is a rotary mechanical device that extracts energy from a fluid flow and converts it into useful work. The work produced by a turbine can be used for generating electrical power when combined with a generator.Munson, Bruce Roy, T. H. Okiishi, and Wade W. Huebsch. "Turbomachines." Fundamentals of Fluid Mechanics. 6th ed. Hoboken, NJ: J. Wiley & Sons, 2009. Print. A turbine is a turbomachine with at least one moving part called a rotor assembly, which is a shaft or drum with blades attached. Moving fluid acts on the blades so that they move and impart rotational energy to the rotor. Early turbine examples are windmills and waterwheels. Gas, steam, and water turbines have a casing around the blades that contains and controls the working fluid. Credit for invention of the steam turbine is given both to Anglo-Irish engineer Sir Charles Parsons (1854–1931) for invention of the reaction turbine, and to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gas Turbine
A gas turbine, also called a combustion turbine, is a type of continuous flow internal combustion engine. The main parts common to all gas turbine engines form the power-producing part (known as the gas generator or core) and are, in the direction of flow: * a rotating gas compressor * a combustor * a compressor-driving turbine. Additional components have to be added to the gas generator to suit its application. Common to all is an air inlet but with different configurations to suit the requirements of marine use, land use or flight at speeds varying from stationary to supersonic. A propelling nozzle is added to produce thrust for flight. An extra turbine is added to drive a propeller (turboprop) or ducted fan (turbofan) to reduce fuel consumption (by increasing propulsive efficiency) at subsonic flight speeds. An extra turbine is also required to drive a helicopter rotor or land-vehicle transmission (turboshaft), marine propeller or electrical generator (power turbine). Greater ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DC-10-30 Resting On Its Tail Due To Pinatubo Ashfall
The Douglas DC-1 was the first model of the famous American DC (Douglas Commercial) commercial transport aircraft series. Although only one example of the DC-1 was produced, the design was the basis for the DC-2 and DC-3, the latter of which being one of the most successful aircraft in the history of aviation. Design and development Development of the DC-1 can be traced back to the 1931 crash of a TWA airliner, a Fokker F-10 trimotor in which a wing failed, probably because water had seeped between the layers of the wood laminate and dissolved the glue holding the layers together. Following the accident, the Aeronautics Branch of the U.S. Department of Commerce placed stringent restrictions on the use of wooden wings on passenger airliners.Friedman and Friedman ''Aeroplane Monthly'' May 2001, pp. 34–40.O'Leary ''Aeroplane Monthly'' February 2007, p. 71. Boeing developed an answer, the 247, a twin-engined all-metal monoplane with a retractable undercarriage, but their producti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operating Temperature
An operating temperature is the allowable temperature range of the local ambient environment at which an electrical or mechanical device operates. The device will operate effectively within a specified temperature range which varies based on the device function and application context, and ranges from the minimum operating temperature to the maximum operating temperature (or peak operating temperature). Outside this range of safe operating temperatures the device may fail. It is one component of reliability engineering. Similarly, biological systems have a viable temperature range, which might be referred to as an "operating temperature". Ranges Most devices are manufactured in several temperature grades. Broadly accepted grades are: *Commercial: 0 ° to 70 °C *Industrial: −40 ° to 85 °C *Military: −55 ° to 125 °C Nevertheless, each manufacturer defines its own temperature grades so designers must pay close attention to actual datasheet spe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chaitén (volcano)
Chaitén is a volcanic caldera in diameter, west of the elongated ice-capped Michinmahuida volcano and northeast of the town of Chaitén, near the Gulf of Corcovado in southern Chile. The most recent eruptive phase of the volcano erupted on 2008. Originally, radiocarbon dating of older tephra from the volcano suggested that its last previous eruption was in 7420 BC ± 75 years. However, recent studies have found that the volcano is more active than thought. According to the Global Volcanism Program, its last eruption was in 2011. The caldera rim reaches above sea level. Before the current eruption, it was mostly filled by a rhyolite obsidian lava dome that reached a height of , partly devoid of vegetation. Two small lakes occupied the caldera floor on the west and north sides of the lava dome. The translucent grey obsidian which had erupted from the volcano was used by pre-Columbian cultures as a raw material for artifacts and has been found as far away as to the so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Vapour
(99.9839 °C) , - , Boiling point , , - , specific gas constant , 461.5 J/( kg·K) , - , Heat of vaporization , 2.27 MJ/kg , - , Heat capacity , 1.864 kJ/(kg·K) Water vapor, water vapour or aqueous vapor is the gaseous phase of water. It is one state of water within the hydrosphere. Water vapor can be produced from the evaporation or boiling of liquid water or from the sublimation of ice. Water vapor is transparent, like most constituents of the atmosphere. Under typical atmospheric conditions, water vapor is continuously generated by evaporation and removed by condensation. It is less dense than most of the other constituents of air and triggers convection currents that can lead to clouds. Being a component of Earth's hydrosphere and hydrologic cycle, it is particularly abundant in Earth's atmosphere, where it acts as a greenhouse gas and warming feedback, contributing more to total greenhouse effect than non-condensable gases such as carbon dioxide and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plume From Eruption Of Chaiten Volcano, Chile
Plume or plumes may refer to: Science * Plume (feather), a prominent bird feather * Plume (fluid dynamics), a column consisting of one fluid moving through another fluid * Eruption plume, a column of volcanic ash and gas emitted into the atmosphere during an eruption * Mantle plume, an upwelling of hot rock within the Earth's mantle that can cause volcanic hotspots * Moisture plume, an alternative name for a atmospheric river, a narrow corridor of concentrated moisture in the atmosphere * Plumage, the layer of feathers that cover a bird Media and literature * "Plume" (Air episode), a 2005 episode of the Japanese anime ''Air'' * '' Plume'', a 2006 album by Loscil * ''Plumes'' (play), a 1927 one-act play by Georgia Douglas Johnson * ''Plume'' (poetry collection), a 2012 book by Kathleen Flenniken * Plume (publisher), an American book publishing company * ''Plumes'', a 1924 novel by Laurence Stallings * A song by The Smashing Pumpkins on their 1994 album ''Pisces Iscariot'' * " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tephra
Tephra is fragmental material produced by a volcanic eruption regardless of composition, fragment size, or emplacement mechanism. Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground, they remain as tephra unless hot enough to fuse into pyroclastic rock or tuff. Tephrochronology is a geochronological technique that uses discrete layers of tephra—volcanic ash from a single eruption—to create a chronological framework in which paleoenvironmental or archaeological records can be placed. When a volcano explodes, it releases a variety of tephra including ash, cinders, and blocks. These layers settle on the land and, over time, sedimentation occurs incorporating these tephra layers into the geologic record. Often, when a volcano explodes, biological organisms are killed and their remains are buried within the tephra layer. These fossils are later dated by scientists to determine the age of the fossil and its place within the geolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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