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Bleed Air
Bleed air is compressed air taken from the compressor stage of a gas turbine upstream of its fuel-burning sections. Automatic air supply and cabin pressure controller (ASCPCs) valves bleed air from high or low stage engine compressor sections. Low stage air is used during high power setting operation, and high during descent and other low power setting operations. Bleed air from that system can be utilized for internal cooling of the engine, cross-starting another engine, engine and airframe anti-icing, cabin pressurization, pneumatic actuators, air-driven motors, pressurizing the hydraulic reservoir, and waste and water storage tanks. Some engine maintenance manuals refer to such systems as "customer bleed air". Bleed air is valuable in an aircraft for two properties: high temperature and high pressure (typical values are 200–250 °C and 275 kPa (40 PSI), for regulated bleed air exiting the engine pylon for use throughout the aircraft). Uses In civil aircraft, bleed air' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compressed Air
Compressed air is air kept under a pressure that is greater than atmospheric pressure. Compressed air is an important medium for transfer of energy in industrial processes, and is used for power tools such as air hammers, drills, wrenches, and others, as well as to atomize paint, to operate air cylinders for automation, and can also be used to propel vehicles. Brakes applied by compressed air made large railway trains safer and more efficient to operate. Compressed air brakes are also found on large highway vehicles. Compressed air is used as a breathing gas by underwater divers. It may be carried by the diver in a high pressure diving cylinder, or supplied from the surface at lower pressure through an air line or diver's umbilical. Similar arrangements are used in breathing apparatus used by firefighters, mine rescue workers and industrial workers in hazardous atmospheres. In Europe, 10 percent of all industrial electricity consumption is to produce compressed air—amountin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lift (force)
A fluid flowing around an object exerts a force on it. Lift is the component of this force that is perpendicular to the oncoming flow direction. It contrasts with the drag force, which is the component of the force parallel to the flow direction. Lift conventionally acts in an upward direction in order to counter the force of gravity, but it can act in any direction at right angles to the flow. If the surrounding fluid is air, the force is called an aerodynamic force. In water or any other liquid, it is called a hydrodynamic force. Dynamic lift is distinguished from other kinds of lift in fluids. Aerostatic lift or buoyancy, in which an internal fluid is lighter than the surrounding fluid, does not require movement and is used by balloons, blimps, dirigibles, boats, and submarines. Planing lift, in which only the lower portion of the body is immersed in a liquid flow, is used by motorboats, surfboards, windsurfers, sailboats, and water-skis. Overview A fluid flowing arou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cabin Pressurization
Cabin pressurization is a process in which conditioned air is pumped into the cabin of an aircraft or spacecraft in order to create a safe and comfortable environment for passengers and crew flying at high altitudes. For aircraft, this air is usually bled off from the gas turbine engines at the compressor stage, and for spacecraft, it is carried in high-pressure, often cryogenic, tanks. The air is cooled, humidified, and mixed with recirculated air if necessary before it is distributed to the cabin by one or more environmental control systems. The cabin pressure is regulated by the outflow valve. While the first experimental pressurization systems saw use during the 1920s and 1930s, it was not until 1940 that a commercial aircraft would enter service with a pressurized cabin, when the Boeing 307 Stratoliner joined the Transcontinental & Western Air and Pan American Airways fleets. The practice would become widespread a decade later, particularly with the introduction of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerotoxic Syndrome
Aerotoxic syndrome relates to ill-health effects that are claimed to be caused by breathing contaminated airliner cabin air. This condition is not an established medical diagnosis. Potential sources of contamination Modern jetliners have environmental control systems (ECS) that manage the flow of cabin air. Outside air enters the engines and is compressed in the forward section of the engine, prior to the combustion section, ensuring no combustion products can enter the cabin. A portion of that compressed bleed air is used to pressurize the cabin. The ECS then recirculates some of that cabin air through HEPA filters, while the rest is directed to outflow valves, ensuring there is a constant supply of fresh, clean air coming into the cabin pressurization system at all times. Jet engines require synthetic oils for lubrication. These oils contain ingredients such as tricresyl phosphate (TCP or TOCP), an organophosphate, which can be toxic to humans but only in quantities much la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fuel Efficiency
Fuel efficiency is a form of thermal efficiency, meaning the ratio of effort to result of a process that converts chemical potential energy contained in a carrier (fuel) into kinetic energy or work. Overall fuel efficiency may vary per device, which in turn may vary per application, and this spectrum of variance is often illustrated as a continuous energy profile. Non-transportation applications, such as industry, benefit from increased fuel efficiency, especially fossil fuel power plants or industries dealing with combustion, such as ammonia production during the Haber process. In the context of transport, fuel economy is the energy efficiency of a particular vehicle, given as a ratio of distance traveled per unit of fuel consumed. It is dependent on several factors including engine efficiency, transmission design, and tire design. In most countries, using the metric system, fuel economy is stated as "fuel consumption" in liters per 100 kilometers (L/100 km) or kilometer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boeing 787 Dreamliner
The Boeing 787 Dreamliner is an American wide-body jet airliner developed and manufactured by Boeing Commercial Airplanes. After dropping its unconventional Sonic Cruiser project, Boeing announced the conventional 7E7 on January 29, 2003, which focused largely on efficiency. The program was launched on April 26, 2004, with an order for 50 aircraft from All Nippon Airways (ANA), targeting a 2008 introduction. On July 8, 2007, a prototype 787 was rolled out without major operating systems, and then the aircraft experienced multiple delays until its maiden flight on December 15, 2009. Type certification was received in August 2011 and the first 787-8 was delivered in September 2011 before entering commercial service on October 26, 2011, with ANA. At launch, Boeing targeted the 787 with 20% less fuel burn than replaced aircraft like the Boeing 767, carrying 200 to 300 passengers on point-to-point routes up to , a shift from hub-and-spoke travel. The twinjet is powered by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spirit Airlines
Spirit Airlines Inc. (stylized as spirit) is a major ultra-low-cost U.S. carrier headquartered in Miramar, Florida, in the Miami metropolitan area. Spirit operates scheduled flights throughout the United States, the Caribbean and Latin America. Spirit was the eighth largest passenger carrier in North America as well as the largest ultra-low-cost carrier in North America. JetBlue has made an offer to acquire Spirit for . , the deal was approved by a majority of the airline's voting shareholders, but the offer awaits approval by government regulators. History Establishment 1964–2007 The company initially started as Clippert Trucking Company in 1964. The company changed its name to Ground Air Transfer, Inc., in 1974. The airline service was founded in 1983 in Macomb County, Michigan, by Ned Homfeld as Charter One Airlines, a Detroit-based charter tour operator providing travel packages to entertainment destinations such as Atlantic City, Las Vegas, and the Bahamas. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toxic Encephalopathy
Toxic encephalopathy is a neurologic disorder caused by exposure to neurotoxic organic solvents such as toluene, following exposure to heavy metals such as manganese, as a side effect of melarsoprol treatment for African trypanosomiasis, adverse effects to prescription drugs, or exposure to extreme concentrations of any natural toxin such as cyanotoxins found in shellfish or freshwater cyanobacteria crusts. Toxic encephalopathy can occur following acute or chronic exposure to neurotoxicants, which includes all natural toxins. Exposure to toxic substances can lead to a variety of symptoms, characterized by an altered mental status, memory loss, and visual problems. Toxic encephalopathy can be caused by various chemicals, some of which are commonly used in everyday life, or cyanotoxins which are bio-accumulated from harmful algal blooms (HABs) which have settled on the benthic layer of a waterbody. Toxic encephalopathy can permanently damage the brain and currently treatment is mainl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Causality
Causality (also referred to as causation, or cause and effect) is influence by which one event, process, state, or object (''a'' ''cause'') contributes to the production of another event, process, state, or object (an ''effect'') where the cause is partly responsible for the effect, and the effect is partly dependent on the cause. In general, a process has many causes, which are also said to be ''causal factors'' for it, and all lie in its past. An effect can in turn be a cause of, or causal factor for, many other effects, which all lie in its future. Some writers have held that causality is metaphysically prior to notions of time and space. Causality is an abstraction that indicates how the world progresses. As such a basic concept, it is more apt as an explanation of other concepts of progression than as something to be explained by others more basic. The concept is like those of agency and efficacy. For this reason, a leap of intuition may be needed to grasp it. Accordin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerotoxic Association
The Aerotoxic Association was founded on 18 June 2007, at the British Houses of Parliament by former BAe 146 Training Captain John Hoyte, to raise public awareness about the ill health allegedly caused after exposure to airliner cabin air that he claimed been contaminated to toxic levels, by engine oil leaking into the bleed air system, which pressurizes all jet aircraft, with the exception of the Boeing 787. In addition to providing help and support to aircrew and passengers, the Aerotoxic Association promotes known technical solutions, such as toxic air detectors, and campaigns for changes in regulations to improve the quality of cabin air on airliners. The phrase "aerotoxic syndrome" was first coined by Chris Winder and Jean-Christophe Balouet in 2000 to describe the ill health allegedly caused by exposure to air which they claimed had been contaminated by jet engine oil. this syndrome is not recognized in medicine. Criticism That report examined all exposures dating back to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tricresyl Phosphate
Tricresyl phosphate (TCP), is a mixture of three isomeric organophosphate compounds most notably used as a flame retardant and as a plasticizer in manufacturing for lacquers and varnishes and vinyl plastics. Pure tricresyl phosphate is a colourless, viscous liquid, although commercial samples are typically yellow. It is virtually insoluble in water, but easily soluble in organic solvents like toluene, hexane, and diethylether among others. It was synthesized by Alexander Williamson in 1854 upon reacting phosphorus pentachloride with cresol (a mixture of para-, ortho-, and meta- isomers of methylphenol), though today's manufacturers can prepare TCP by mixing cresol with phosphorus oxychloride or phosphoric acid as well. TCP, especially the all-ortho isomer, is the causative agent in a number of acute poisonings. Its chronic toxicity is also of concern. The ortho-isomer is rarely used on its own outside of laboratory studies that require isomeric purity, due to its extremely to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerotoxic Syndrome
Aerotoxic syndrome relates to ill-health effects that are claimed to be caused by breathing contaminated airliner cabin air. This condition is not an established medical diagnosis. Potential sources of contamination Modern jetliners have environmental control systems (ECS) that manage the flow of cabin air. Outside air enters the engines and is compressed in the forward section of the engine, prior to the combustion section, ensuring no combustion products can enter the cabin. A portion of that compressed bleed air is used to pressurize the cabin. The ECS then recirculates some of that cabin air through HEPA filters, while the rest is directed to outflow valves, ensuring there is a constant supply of fresh, clean air coming into the cabin pressurization system at all times. Jet engines require synthetic oils for lubrication. These oils contain ingredients such as tricresyl phosphate (TCP or TOCP), an organophosphate, which can be toxic to humans but only in quantities much la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
