title: CFM International CFM56

text: Development work on the CFM56 began before CFMI was formally created. While work proceeded smoothly, the international arrangement led to unique working conditions. For example, both companies had assembly lines, some engines were assembled and tested in the U.S. and others in France. Engines assembled in France were subject to the initially strict export agreement, which meant that GE's core was built in the U.S., then shipped to the Snecma plant in France where it was placed in a locked room into which even the President of Snecma was not allowed. The Snecma components (the fore and aft sections of the engine) were brought into the room, GE employees mounted them to the core, and then the assembled engine was taken out to be finished.


title: CFM International CFM56

text: The first completed CFM56 engine first ran at GE in June 1974 with the second running in October 1974. The second engine was then shipped to France and first ran there on 13 December 1974. These first engines were considered "production hardware" as opposed to test examples and were designated as the CFM56-2, the first variant of the CFM56.


title: CFM International CFM56

text: The engine flew for the first time in February 1977 when it replaced one of the four Pratt & Whitney JT8D engines on the McDonnell Douglas YC-15, an entrant in the Air Force's Advanced Medium STOL Transport (AMST) competition. Soon after, the second CFM56 was mounted on a Sud Aviation Caravelle at the Snecma flight test center in France. This engine had a slightly different configuration with a long bypass duct and mixed exhaust flow, rather than a short bypass duct with unmixed exhaust flow. It was the first to include a "Thrust Management System".


title: CFM International CFM56

text: After testing the engine for several years, both in the air and on the ground, CFMI searched for customers outside of a possible AMST contract. The main targets were re-engine contracts for the Douglas DC-8 and the Boeing 707 airliners, including the related military tanker, the KC-135 Stratotanker. There was little initial interest in the engine, but Boeing realized that the CFM56 might be a solution to upcoming noise regulations. After announcing that a 707 would be configured with the CFM56 engine for flight tests in 1977, Boeing officially offered the 707-320 with the CFM56 engine as an option in 1978. The new variant was listed as the 707-700. Due to limited interest from the airlines in a re-engined 707, Boeing ended the 707-700 program in 1980 without selling any aircraft. Despite the lack of sales, having the commercial 707 available with the CFM56 helped the engine's competitiveness for the KC-135 re-engine contract.


title: CFM International CFM56

text: Winning the contract to re-engine the KC-135 tanker fleet for the USAF would be a huge boon to the CFM56 project (with more than 600 aircraft available to re-engine), and CFMI aggressively pursued that goal as soon as the Request For Proposals (RFP) was announced in 1977. Like other aspects of the program, international politics played their part in this contract. In efforts to boost the CFM56's chances versus its competitors, the Pratt & Whitney TF33 and an updated Pratt & Whitney JT8D, the French government announced in 1978 that they would upgrade their 11 KC-135s with the CFM56, providing one of the first orders for the engine.


title: CFM International CFM56

text: The USAF announced the CFM56 as the winner of the re-engine contract in January 1980. Officials indicated that they were excited at the prospect of replacing the Pratt & Whitney J57 engines currently flying on the KC-135A aircraft, calling them "...the noisiest, dirtiest, [and] most fuel inefficient powerplant still flying" at the time. The re-engined aircraft was designated the KC-135R. The CFM56 brought many benefits to the KC-135, decreasing takeoff distance by as much as 3,500 ft (1,100 m), decreasing overall fuel usage by 25%, greatly reducing noise (24 dB lower) and lowering total life cycle cost. With those benefits in mind, the United States Navy selected the CFM56-2 to power their variant of the Boeing 707, the E-6 Mercury, in 1982. In 1984 the Royal Saudi Air Force selected the CFM56-2 to power their E-3 Sentry aircraft (also related to the 707 airframe). The CFM56-2-powered E-3 also became the standard configuration for aircraft purchased by the British and French.


title: CFM International CFM56

text: By the end of the 1970s, airlines were considering upgrading their aging Douglas DC-8 aircraft as an alternative to buying new quieter and more efficient aircraft. Following the French KC-135 order in 1978, the April 1979 decision by United Airlines to upgrade 30 of their DC-8-61 aircraft with the CFM56-2 was important for securing the development of the CFM56; GE and Snecma were two weeks away from freezing development had that order not materialized. This decision marked the first commercial purchase (rather than government/military) of the engine, and Delta Air Lines and Flying Tiger Line soon followed suit, giving the CFM56 a firm footing in both the military and commercial market.


title: CFM International CFM56

text: In the early 1980s Boeing selected the CFM56-3 to exclusively power the Boeing 737-300 variant. The 737 wings were closer to the ground than previous applications for the CFM56, necessitating several modifications to the engine. The fan diameter was reduced, which reduced the bypass ratio, and the engine accessory gearbox was moved from the bottom of the engine (the 6 o'clock position) to the 9 o'clock position, giving the engine nacelle its distinctive flat-bottomed shape. The overall thrust was also reduced, from , mostly due to the reduction in bypass ratio.


title: CFM International CFM56

text: Since the small initial launch order for twenty 737-300s split between two airlines, over 5,000 Boeing 737 aircraft had been delivered with CFM56 turbofans by April 2010.


title: CFM International CFM56

text: In 1998, CFMI launched the "Tech56" development and demonstration program to create an engine for the new single-aisle aircraft that were expected to be built by Airbus and Boeing. The program focused on developing a large number of new technologies for the theoretical future engine, not necessarily creating an all-new design. When it became clear that Boeing and Airbus were not going to build all-new aircraft to replace the 737 and A320, CFMI decided to apply some of those Tech56 technologies to the CFM56 in the form of the "Tech Insertion" program which focused on three areas: fuel efficiency, maintenance costs and emissions. Launched in 2004, the package included redesigned high-pressure compressor blades, an improved combustor, and improved high- and low-pressure turbine components which resulted in better fuel efficiency and lower nitrogen oxides (NO) emissions. The new components also reduced engine wear, lowering maintenance costs by about 5%. The engines entered service in 2007, and all new CFM56-5B and CFM56-7B engines are being built with the Tech Insertion components. CFMI also offers the components as an upgrade kit for existing engines.


title: CFM International CFM56

text: In 2009, CFMI announced the latest upgrade to the CFM56 engine, the "CFM56-7B Evolution" or CFM56-7BE. This upgrade, announced with improvements to Boeing's 737 Next Generation, further enhances the high- and low-pressure turbines with better aerodynamics, as well as improving engine cooling, and aims to reduce overall part count. CFMI expected the changes to result in a 4% reduction in maintenance costs and a 1% improvement in fuel consumption (2% improvement including the airframe changes for the new 737); flight and ground tests completed in May 2010 revealed that the fuel burn improvement was better than expected at 1.6%. Following 450 hours of testing, the CFM56-7BE engine was certified by FAA and EASA on 30 July 2010 and delivered from mid-2011.


title: CFM International CFM56

text: The CFM56-5B/3 PIP (Performance Improvement Package) engine includes these new technologies and hardware changes to lower fuel burn and lower maintenance cost. Airbus A320s were to use this engine version starting in late 2011.


title: CFM International CFM56

text: The LEAP is a new engine design based on and designed to replace the CFM56 series, with 16% efficiency savings by using more composite materials and achieving higher bypass ratios of over 10:1. LEAP entered service in 2016.


title: CFM International CFM56

text: As of June 2016, the CFM56 is the most-used high-bypass turbofan. It has achieved more than 800 million engine flight hours, and at a rate of one million flight hours every eight days it is expected to have achieved one billion flight hours by 2020. It has more than 550 operators and more than 2,400 CFM56-powered jet aircraft are in the air at any given moment. It is known for its dependability: its average time on wing is 30,000 hours before a first shop visit, with the current fleet record at 50,000 hours.


title: CFM International CFM56

text: As of July 2016, 30,000 engines have been built: 9,860 CFM56-5 engines for the Airbus A320ceo and A340-200/300 and more than 17,300 CFM56-3/-7B engines for the Boeing 737 Classic and 737NG. In July 2016, CFM had 3,000 engines in backlog. Lufthansa, launch customer for the CFM56-5C-powered A340, have an engine with more than 100,000 flight hours, having entered commercial service on 16 November 1993, overhauled four times since. In 2016 CFM delivered 1,665 CFM56 and booked 876 orders, it plans to produce CFM56 spare parts until 2045.


title: CFM International CFM56

text: By October 2017, CFM had delivered more than 31,000 engines and 24,000 were in service with 560 operators, it attained 500 million flight cycles and 900 million flight hours, including over 170 million cycles and 300 million hours since 1998 for the B737NG's -7B and over 100 million cycles and 180 million hours for the A320ceo's -5B since 1996. By June 2018, 32,645 were delivered. Strong demand will extend production to 2020, up from 2019.


title: CFM International CFM56

text: Exhaust gas temperature margin erodes with usage. One or two performance restoration shop visits, costing $0.3-$0.6m for a -5 series, can be performed before taking the engine off wing, which can restore 60% to 80% of the original margin. Once restored, the life limited parts must be replaced after: 20,000 cycles for the hot section ($0.5m), 25,000 for the axial compressor, and 30,000 for the fan and booster ($0.5m-$0.7m) for a recent CFM56. The whole engine parts cost more than $3m, $3.5 to $4m with the shop work-hours, around $150 per cycle.


title: CFM International CFM56

text: By June 2019, the CFM56 fleet had surpassed one billion engine flight hours (nearly 115,000 years), having carried more than 35 billion people, over eight million times around the world.


title: CFM International CFM56

text: The CFM56 production will wind down as the final 737NG engine was delivered in 2019 and the last A320ceo engine will be delivered in May 2020. Production will continue at low levels for military 737s and spare engines and will conclude around 2024.


title: CFM International CFM56

text: The CFM56 is a high-bypass turbofan engine (most of the air accelerated by the fan bypasses the core of the engine and is exhausted out of the fan case) with several variants having bypass ratios ranging from 5:1 to 6:1, generating 18,500 to 34,000 lbf (80 kN to 150 kN) of thrust. The variants share a common design, but the details differ. The CFM56 is a two-shaft (or two-spool) engine, meaning that there are two rotating shafts, one high-pressure and one low-pressure. Each is powered by its own turbine section (the high-pressure and low-pressure turbines, respectively). The fan and booster (low-pressure compressor) evolved over the different iterations of the engine, as did the compressor, combustor and turbine sections.


title: CFM International CFM56

text: Most variants of the CFM56 feature a single-annular combustor. An annular combustor is a continuous ring where fuel is injected into the airflow and ignited, raising the pressure and temperature of the flow. This contrasts with a can combustor, where each combustion chamber is separate, and a canannular combustor which is a hybrid of the two. Fuel injection is regulated by a Hydromechanical Unit (HMU), built by Honeywell. The HMU regulates the amount of fuel delivered to the engine by means of an electrohydraulic servo valve that, in turn, drives a fuel metering valve, that provides information to the full authority digital engine controller (FADEC).


title: CFM International CFM56

text: In 1989, CFMI began work on a new, double-annular combustor. Instead of having just one combustion zone, the double-annular combustor has a second combustion zone that is used at high thrust levels. This design lowers the emissions of both nitrogen oxides (NO) and carbon dioxide (CO). The first CFM56 engine with the double-annular combustor entered service in 1995, and the combustor is used on CFM56-5B and CFM56-7B variants with the suffix "/2" on their nameplates.


title: CFM International CFM56

text: GE started developing and testing a new type of combustor called the Twin Annular Premixing Swirler combustor, or "TAPS", during the Tech 56 program. This design is similar to the double-annular combustor in that it has two combustion zones; this combustor "swirls" the flow, creating an ideal fuel–air mixture. This difference allows the combustor to generate much less NO than other combustors. Tests on a CFM56-7B engine demonstrated an improvement of 46% over single-annular combustors and 22% over double-annular combustors. The analytical tools developed for TAPS have also been used to improve other combustors, notably the single-annular combustors in some CFM56-5B and -7B engines.


title: CFM International CFM56

text: The high-pressure compressor (HPC), that was at the center of the original export controversy, features nine stages in all variants of the CFM56. The compressor stages have been developed from GE's "GE core" (namely a single-turbine, nine-compressor stage design) which was designed in a compact core rotor. The small span of the compressor radius meant that the entire engine could be lighter and smaller, as the accessory units in the system (bearings, oiling systems) could be merged to the main fueling system running on aviation fuel. As design evolved "HPC" design improved through better airfoil design. As part of the Tech-56 improvement program CFMI has tested the new CFM-56 model with six-stage high-pressure compressor stages (discs that make up the compressor system) that was designed to deliver same pressure ratios (pressure gain 30) similar to the old nine-stages compressor design. The new one was not fully replacing the old one, but it offered an upgrade in HPC, thanks to improved blade dynamics, as a part of their "Tech Insertion" management plan from 2007.


title: CFM International CFM56

text: CFMI tested both a mixed and unmixed exhaust design at the beginning of development; most variants of the engine have an unmixed exhaust nozzle. Only the high-power CFM56-5C, designed for the Airbus A340, has a mixed-flow exhaust nozzle.


title: CFM International CFM56

text: GE and Snecma also tested the effectiveness of chevrons on reducing jet noise. After examining configurations in the wind tunnel, CFMI chose to flight-test chevrons built into the core exhaust nozzle. The chevrons reduced jet noise by 1.3 perceived loudness decibels during takeoff conditions, and are now offered as an option with the CFM56 for the Airbus A321.


title: CFM International CFM56

text: The CFM56 features a single-stage fan, and most variants have a three-stage booster on the low-pressure shaft, with four stages in the -5B and -5C variants. The booster is also commonly called the "low-pressure compressor" (LPC) as it is part of the low-pressure spool and continues the air compression done by the inner part of the fan before it reaches the high-pressure compressor. The original CFM56-2 variant featured 44 tip-shrouded fan blades, although the number of fan blades was reduced in later variants as wide-chord blade technology developed, down to 22 blades in the CFM56-7 variant.


title: CFM International CFM56

text: The CFM56 fan features dovetailed fan blades which allows them to be replaced without removing the entire engine, and GE/Snecma claim that the CFM56 was the first engine to have that capability. This attachment method is useful for circumstances where only a few fan blades need to be repaired or replaced, such as following bird strikes.


title: CFM International CFM56

text: The fan diameter varies with the different models of the CFM56, and that change has a direct impact on the engine performance. For example, the low-pressure shaft rotates at the same speed for both the CFM56-2 and the CFM56-3 models; the fan diameter is smaller on the -3, which lowers the tip speed of the fan blades. The lower speed allows the fan blades to operate more efficiently (5.5% more in this case), which increases the overall fuel efficiency of the engine (improving specific fuel consumption nearly 3%).


title: CFM International CFM56

text: The CFM56 is designed to support several thrust reverser systems which help slow and stop the aircraft after landing. The variants built for the Boeing 737, the CFM56-3 and the CFM56-7, use a cascade type of thrust reverser. This type of thrust reverse consists of sleeves that slide back to expose mesh-like cascades and blocker doors that block the bypass air flow. The blocked bypass air is forced through the cascades, reducing the thrust of the engine and slowing the aircraft down.


title: CFM International CFM56

text: The CFM56 also supports pivoting-door type thrust reversers. This type is used on the CFM56-5 engines that power many Airbus aircraft such as the Airbus A320. They work by actuating a door that pivots down into the bypass duct, both blocking the bypass air and deflecting the flow outward, creating the reverse thrust.


title: CFM International CFM56

text: All variants of the CFM56 feature a single-stage high-pressure turbine (HPT). In some variants, the HPT blades are "grown" from a single crystal superalloy, giving them high strength and creep resistance. The low-pressure turbine (LPT) features four stages in most variants of the engine, but the CFM56-5C has a five-stage LPT. This change was implemented to drive the larger fan on this variant. Improvements to the turbine section were examined during the Tech56 program, and one development was an aerodynamically optimized low-pressure turbine blade design, which would have used 20% fewer blades for the whole low-pressure turbine, saving weight. Some of those Tech56 improvements made their way into the Tech Insertion package, where the turbine section was updated. The turbine section was updated again in the "Evolution" upgrade.


title: CFM International CFM56

text: The high-pressure turbine stages in the CFM56 are internally cooled by air from the high-pressure compressor. The air passes through internal channels in each blade and ejects at the leading and trailing edges.


title: CFM International CFM56

text: The CFM56-2 series is the original variant of the CFM56. It is most widely used in military applications where it is known as the F108; specifically in the KC-135, the E-6 Mercury and some E-3 Sentry aircraft. The CFM56-2 comprises a single-stage fan with 44 blades, with a three-stage LP compressor driven by a four-stage LP turbine, and a nine-stage HP compressor driven by a single-stage HP turbine. The combustor is annular.


title: CFM International CFM56

text: The first derivative of the CFM56 series, the CFM56-3 was designed for Boeing 737 Classic series (737-300/-400/-500), with static thrust ratings from . A "cropped fan" derivative of the -2, the -3 engine has a smaller fan diameter at 60 in (1.5 m) but retains the original basic engine layout. The new fan was primarily derived from GE's CF6-80 turbofan rather than the CFM56-2, and the booster was redesigned to match the new fan.


title: CFM International CFM56

text: A significant challenge for this series was achieving ground clearance for the wing-mounted engine. This was overcome by reducing the intake fan diameter and relocating the gearbox and other accessories from beneath the engine to the sides. The resulting flattened nacelle bottom and intake lip yielded the distinctive appearance of the Boeing 737 with CFM56 engines.


title: CFM International CFM56

text: The CFM56-4 series was a proposed improved version of the CFM56-2 designed for the Airbus A320 family of aircraft. Competing with the RJ500 engine being developed by Rolls-Royce, the -4 series was designed to produce 25,000 lbf (110 kN) and was to feature a new 68 in (1.73 m) fan, a new low-pressure compressor and a full authority digital engine controller (FADEC). Soon after the upgrade project was launched in 1984, International Aero Engines offered their new V2500 engine for the A320. CFMI realized that the CFM56-4 did not compare favorably with the new engine and scrapped the project to begin working on the CFM56-5 series.


title: CFM International CFM56

text: The CFM56-5 series is designed for the Airbus aircraft and has a very wide thrust rating of between . It has three distinct sub-variants; the CFM56-5A, CFM56-5B and CFM56-5C, and differs from its Boeing 737 Classic-fitted cousins by featuring a FADEC and incorporating further aerodynamic design improvements.


title: CFM International CFM56

text: The CFM56-5A series is the initial CFM56-5 series, designed to power the short-to-medium range Airbus A320 family. Derived from the CFM56-2 and CFM56-3 families, the -5A series produces thrusts between 22,000 and 26,500 lbf (98 kN and 118 kN). Aerodynamic improvements such as an updated fan, low-pressure compressor, high-pressure compressor and combustor make this variant 10–11% more fuel efficient than its predecessors.


title: CFM International CFM56

text: An improvement of the CFM56-5A series, it was originally designed to power the A321. With a thrust range between 22,000 and 33,000 lbf (98 kN and 147 kN) it can power every model in the A320 family (A318/A319/A320/A321) and has superseded the CFM56-5A series. Among the changes from the CFM56-5A is the option of a double-annular combustor that reduces emissions (particularly NO), a new fan in a longer fan case, and a new low-pressure compressor with a fourth stage (up from three in earlier variants). It is the most numerous engine supplied to Airbus.


title: CFM International CFM56

text: With a thrust rating of between 31,200 and 34,000 lbf (139 kN and 151 kN), the CFM56-5C series is the most powerful of the CFM56 family. It powers Airbus' long-range A340-200 and -300 airliners, and entered service in 1993. The major changes are a larger fan, a fifth low-pressure turbine stage, and the same four-stage low-pressure compressor found in the -5B variant.


title: CFM International CFM56

text: Unlike every other variant of the CFM56, the -5C features a mixed-exhaust nozzle, which offers slightly higher efficiency.


title: CFM International CFM56

text: The CFM56-7 first ran on 21 April 1995. Rated with a takeoff thrust range of , it powers the -600/-700/-800/-900 Boeing 737 Next Generation; compared to the CFM56-3, it has greater durability, 8% fuel burn improvement and a 15% reduction in maintenance costs.


title: CFM International CFM56

text: Improvements are due to its 61-inch titanium wide chord fan, 3D aerodynamics designed new core and low-pressure turbine with single crystal high-pressure turbine and Full Authority Digital Engine Control (FADEC). Fan blades are reduced from 36 (CFM56-5) to 24 and it incorporates features from the CFM56-5B such as a double-annular combustor as an option.


title: CFM International CFM56

text: Less than two years after entry into service, the Next-Generation 737 received 180 minutes Extended range twin engine Operations (ETOPS) certification from the US Federal Aviation Administration (FAA). It also powers the Boeing 737 military versions : Airborne Early Warning & Control, C-40 Clipper transport and P-8 Poseidon Maritime Aircraft.


title: CFM International CFM56

text: The CFM56 has an in-flight shutdown rate of 1 incident per 333,333 hours. Record time on wing before the first shop visit was 30,000 hours in 1996, to 40,729 hours in 2003 and 50,000 hours in 2016.


title: CFM International CFM56

text: There have been several engine failures in the early service of the CFM56 family which were serious enough to either ground the fleet or require aspects of the engine to be redesigned. The engines have also suffered, periodically, from thrust instability events tentatively traced to Honeywell's hydromechanical unit.


title: CFM International CFM56

text: There are several recorded incidents of CFM56 engines flaming out in heavy rain and/or hail conditions, beginning early in the CFM56's career. In 1987, a double flameout occurred in hail conditions (the pilots managed to relight the engines), followed by the TACA Flight 110 incident in 1988. Both CFM56 engines on the TACA 737 flamed out while passing through hail and heavy rain, and the crew was forced to land without engines on a grassy levee near New Orleans, Louisiana. CFMI modified the engines by adding a sensor to force the combustor to continuously ignite under these conditions.


title: CFM International CFM56

text: In 2002, Garuda Indonesia Flight 421 had to ditch in a river because of hail-induced engine flameouts, killing a flight attendant and injuring dozens of passengers. Prior to this accident, there were several other incidents of single or dual flameouts due to these weather conditions. After three incidents through 1998, CFMI made modifications to the engine to improve the way in which the engine handled hail ingestion. The major changes included a modification to the fan/booster splitter (making it more difficult for hail to be ingested by the core of the engine) and the use of an elliptical, rather than conical, spinner at the intake. These changes did not prevent the 2002 accident, and the investigation board found that the pilots did not follow the proper procedures for attempting to restart the engine, which contributed to the final result. Recommendations were made to better educate pilots on how to handle these conditions, as well as to revisit FAA rain and hail testing procedures. No further engine modifications were recommended.


title: CFM International CFM56

text: One issue that led to accidents with the CFM56-3C engine was the failure of fan blades. This mode of failure led to the Kegworth air disaster in 1989, which killed 47 people and injured 74 more. After the fan blade failed, the pilots mistakenly shut down the wrong engine, resulting in the damaged engine failing completely when powered up for the final approach. Following the Kegworth accident, CFM56 engines fitted to a Dan-Air 737-400 and a British Midland 737-400 suffered fan blade failures under similar conditions; neither incident resulted in a crash or injuries. After the second incident, the 737-400 fleet was grounded.


title: CFM International CFM56

text: At the time it was not mandatory to flight test new variants of existing engines, and certification testing failed to reveal vibration modes that the fan experienced during the regularly performed power climbs at high altitude. Analysis revealed that the fan was being subjected to high-cycle fatigue stresses worse than expected and also more severe than tested for certification; these higher stresses caused the blade to fracture. Less than a month after grounding, the fleet was allowed to resume operations once the fan blades and fan disc were replaced and the electronic engine controls were modified to reduce maximum engine thrust to 22,000 lbf (98 kN) from 23,500 lbf (105 kN). The redesigned fan blades were installed on all CFM56-3C1 and CFM56-3B2 engines, including over 1,800 engines that had already been delivered to customers.


title: CFM International CFM56

text: In August 2016 Southwest Airlines Flight 3472 suffered a fan blade failure, but landed later without further incident. While the aircraft sustained substantial damage, there were no injuries.


title: CFM International CFM56

text: On 17 April 2018, Southwest Airlines Flight 1380 suffered from what appears to be a fan blade failure, debris from which punctured a window. The Boeing 737-700 landed safely, but one passenger was killed and several were injured.


title: CFM International CFM56

text: Airlines have reported 32 events involving sudden instability of thrust, at various points during flight, including high thrust settings during climb to altitude. The problem has been long-standing. In 1998, two 737 pilots reported that their engine throttles suddenly increased to full thrust during flight. A very recent investigation has led to the tentative conclusion that the problem originates in the Hydromechanical unit, and may involve an unacceptable level of fuel contamination (with water, or particulate matter, including biodegradable material that create solids in the fuel), or overuse of biocides to reduce bacterial growth. Boeing told "Aviation Week and Space Technology" that CFM International had revised its FADEC software. The new software "...'reduces the duration and degree of thrust-instability events' by cycling the fuel monitoring valve (FMV) and the EHSV (electrohydraulic servo valve) to clean the EHSV spool." This software fix is not intended to be a definitive solution to the problem; CFM claimed that no further reports have reached it after this change was made.


title: 100 Days My Prince

text: 100 Days My Prince () is a 2018 South Korean television series starring Doh Kyung-soo and Nam Ji-hyun. The series aired on tvN from September 10 to October 30, 2018, every Monday and Tuesday at 21:30 (KST). It is one of the highest-rated Korean dramas in cable television history.


title: 100 Days My Prince

text: Lee Yul is the king's nephew who enjoys spending his days playing instead of studying. He enjoys playing with the peasant children alongside his best friend and guardian, Dong-joo. One day, as he is playing with the peasant children where they play the villains, Yul uses his status to punish the children by beating them up, oblivious that his actions are hurting them. The children could not object to this treatment due to Yul's status. A girl, Yoon Yi-seo intervenes and chides Yul for his cruel actions. Like Yul, Yi-seo is from a noble family, but is kind, smart and compassionate. Yul instantly develops a crush on Yi-seo, and this causes him to change to become more studious in order to impress her. Yi-seo's father is a general and the right-hand man of the king.


title: 100 Days My Prince

text: However, Yul's father is an ambitious man who is jealous of his brother, the king, and vies for the throne. Scheming with another ambitious man, Kim Cha-eon, they plot to overthrow the current king, with the promise that Cha-eon will be handsomely rewarded. One night, Kim Cha-eon begins the coup which sees the king and all his men and allies ruthlessly murdered, including Yi-seo's father. While fatally injured, Yi-seo's father instructs his elder son Seok-ha to take Yi-seo and run away, as Cha-eon is determined to wipe out the entire family. As Cha-eon is about to deal the killing blow, Yul, who has been witnessing the whole thing, comes out from his hiding to stop Cha-eon, threatening that he will report this matter to his father. Cha-eon then carries Yul back to his father' mansion and it is then made known that he has been conspiring with Cha-eon for the whole thing all along, shocking Yul. Yul is removed from the scene and the coup is completed successfully. Due to this, Yul's father is crowned as the new king and Cha-eon becomes the vice-premier. Yul automatically assumes the title of Crown Prince, and is further shocked on the coronation day with the news of his mother's "accidental death". Despite the new king's surprise at the news, it becomes clear that the vice-premier will be the person who has the most power and control of the new reign. Yul bitterly resents his new position as the Crown Prince of Joseon.


title: 100 Days My Prince

text: Sixteen years later, Yul has grown up to be a cold and unlikable crown prince, due to the trauma of his past. Yul is also very smart and skilled in the martial arts. His father is now remarried to the new queen who dislikes him and wants the Crown Prince title for her own son while he himself is married to Kim So-hye, who is Vice-premier Kim's daughter. Despite the marriage, Yul still longs for Yi-seo, even though he believes that Yi-seo was killed. This causes him to despise the crown princess and her father. Yul constantly avoids consummating the marriage, despite the various schemes to ensure the consummation takes place. At the same time, a drought occurs in Joseon and people begin to blame Yul and his refusal to consummate the marriage as the reason. Annoyed, Yul orders all the singles in the nation to be married off in a month to help alleviate the drought.


title: 100 Days My Prince

text: While en route to a rain ritual, Yul and his followers are ambushed by assassins arranged by Cha-eon, and he is almost killed. The crown princess was pregnant with another's child (later revealed to be Mu Yeon's, Hong-shim/Yi-Seo's brother) and the crown prince's assassination attempt was to escape from her predicament. His childhood friend and guardian, Dong-joo, forces them to switch their garments, essentially luring the attackers away from Yul. Dong-joo is subsequently killed and falls into the river. The attackers do not see his face and thus believe that it is Yul. Meanwhile, Yul gets shot with an arrow on his chest while on the run, and accidentally knocks his head, becoming unconscious. When he wakes up, he has already lost his memory.


title: 100 Days My Prince

text: Yi-seo, who managed to escape unscathed in the coup years ago, has been adopted by a commoner man and now lives undercover as a peasant girl named Hong-shim in Songjoo Village. It is her adoptive father who eventually finds the terribly wounded Yul and nurses him back to consciousness. The fate of her brother Seok-ha is unknown, as they separated after Seok-ha buried her under a stack of leaves and ran away to lure Cha-eon's people who were hunting them in the woods. Before separating, they promised to wait for each other at a bridge every 15th of the month. While Yi-seo goes to the bridge as promised without fail, it has been sixteen years since the separation and she is beginning to lose hope that her brother is still alive.


title: 100 Days My Prince

text: As a single woman, Hong-shim is also subjected to the crown prince's marriage decree and she happens to be the oldest single woman in the village. Due to the imbalance number of single men and women, Hong-shim finds herself the only one without a pair. Instead, she receives an offer to become the concubine of a lecherous nobleman. Hong-shim refuses because she says that she is already betrothed to a man named Won-deuk who is serving in the military and has no intention of being the nobleman's fifth wife. The deadline for the decree passes by and since Hong-shim is still unmarried, she is subjected to the punishment of 100 floggings. To save her, her father takes advantage of Yul's amnesia. A very skeptical Yul is told that he is Hong-shim's betrothed, Won-deuk, a man whom her father had recommended but whom she had never met.


title: 100 Days My Prince

text: The rest of the story follows how the prince seems very strange to the commoner's lifestyle and is initially considered a good-for-nothing-husband by the villagers. However, his skills of reading, writing and martial arts remain which impresses Hong-shim and the villagers. He eventually returns to the palace and regains his memories of Yi-seo later and the two reunite again.


title: 100 Days My Prince

text: In the Philippines, "Hinahanap" sung by Three Two One was released under ABS-CBN Star Music and was the show's theme song.


title: Odd Taxi

text: , is a Japanese anime television series. Set in a world of anthropomorphic animals, it tells the story of walrus taxi driver Odokawa, who converses with his customers and learns about various mysteries and oddities occurring in Tokyo, including a schoolgirl's strange disappearance that leads to him being followed by both the police and the "yakuza".


title: Odd Taxi

text: The series, produced by OLM and P.I.C.S, was broadcast on TV Tokyo and AT-X from April to June 2021, and was licensed by Crunchyroll in North America and Mighty Media in Southeast Asia. Prior to its release, a manga from Shogakukan (via Big Comics) began publication in January 2021, and was serialized in its "Superior Dalpana" magazine till July 2022. An anime film, "", was released in Japan in April 2022.


title: Odd Taxi

text: Set in a world of anthropomorphic animals, "Odd Taxi" tells the story of Odokawa, a 41-year old walrus taxi driver whose parents abandoned him in elementary school, leaving him generally asocial. However, he usually has conversations with other animal inhabitants who ride in his taxi on their respective journeys around Tokyo, where the series is set. Odokawa's conversations with these people unravel into a series of mysteries and acts of violence, including that of a missing high school girl. Because of the case of the missing girl, the police have been tracking leads back to him, and now he is being followed by both the "yakuza" and the police.


title: Odd Taxi

text: The anime television series aired on TV Tokyo and AT-X in Japan from April 6 to June 29, 2021. It is directed and storyboarded by Baku Kinoshita and written by Kazuya Konomoto while Konomoto and Hiromi Nakayama designed the characters. The music for the series is composed by OMSB, PUNPEE and VaVa. The series' first 4 episodes had an advanced screening on March 20, 2021 featuring the cast of the series, while a special digest version of those episodes was also streamed online. Singer-songwriter Skirt and rapper/DJ PUNPEE performed the series' main theme "Odd Taxi", while Suzuko Mimori performed the series' ending theme song "Sugarless Kiss". Crunchyroll streamed the series in North American territories. Mighty Media has licensed the series in Southeast Asian territories.


title: Odd Taxi

text: The production committee originally had no plans to release a Blu-Ray Box set, but due to audience demand, it was announced that a Blu-Ray boxset will be released if at least 300 pre-orders would be made during a pre-order campaign. Pony Canyon reported that at least 500 pre-orders were made at a cost of 27,500 Yen ($USD246).


title: Odd Taxi

text: On October 28, 2021, Crunchyroll announced that the series will receive an English dub, which was originally set for release on January 16, 2022. However, it was rescheduled for a release on February 14 instead.


title: Odd Taxi

text: An audio drama ran concurrently to the anime, being uploaded on the anime's official Youtube channel, with the first episode released on April 6, 2021. The drama follows conversations between characters transmitted from a bugged pen which is shown throughout the series.


title: Odd Taxi

text: A manga adaptation by Kazuya Konomoto and illustrated by Takeichi Abaraya began serialization on Shogakukan's "Superior Dalpana" digital manga site on January 15, 2021 and ended on July 22, 2022. It was collected into five volumes.


title: Odd Taxi

text: A novel adaptation by Manabu Wakui, based on Kazuya Konomoto script, was released on July 6, 2021. The novel is a retelling of several key moments of the anime from the point of view of different characters.


title: Odd Taxi

text: On December 25, 2021, an anime film adaptation titled "" was announced. The cast and staff from the series returned to reprise their roles. It was released in Japan on April 1, 2022.


title: Odd Taxi

text: Episode 6 featured the special ending theme 壁の向こうに笑い声を聞きましたか ("Kabe no Mukou ni Waraigoe wo Kikimashita ka", Did you hear the laughter beyond the wall?) by Japanese singer Tony Frank.


title: Odd Taxi

text: METEOR, the voice actor for Yano, released an album titled "2019" under the SUMMIT label that features compositions from the perspective of his character.


title: Odd Taxi

text: A Twitter account was set up prior to the show's release featuring tweets written by hippopotamus character Kabasawa Taichi throughout the show's events under the handle @kbsw_t. The most popular post under the handle was posted on October 10, 2020, and features a selfie between the protagonist Odokawa and Kabasawa, with the tweet attracting attention in April when the episode aired in Japan.


title: Odd Taxi

text: "Odd Taxi" was listed by "The New Yorker"'s "Best TV of 2021" list as an honorable mention. Reviewer Doreen St. Félix stated that the show's "noir humor ... made [her] feel crazy—in a good way". The show was named as the best anime of the year by "IGN", describing "Odd Taxi" as "a fascinating mystery drama with incredible writing, deeply developed and memorable characters, and a unique art style that stands out". Austin Jones and Reuben Baron listed "Odd Taxi" as the "Best New Anime Series" of 2021 in "Paste", describing the show as "one of the best anime of recent years, and unlike anything else out there right now" remarking on the "banter between the cast’s characters [revealing] a deeply human view of modern life".


title: Triton (mythology)

text: Triton (; ) is a Greek god of the sea, the son of Poseidon and Amphitrite, god and goddess of the sea respectively. Triton lived with his parents in a golden palace on the bottom of the sea. Later he is often depicted as having a conch shell he would blow like a trumpet.


title: Triton (mythology)

text: Triton is usually represented as a merman, with the upper body of a human and the tailed lower body of a fish. At some time during the Greek and Roman era, Triton(s) became a generic term for a merman (mermen) in art and literature. In English literature, Triton is portrayed as the messenger or herald for the god Poseidon.


title: Triton (mythology)

text: Triton of Lake Tritonis of ancient Libya is a namesake mythical figure that appeared and aided the Argonauts. Moreover, according to Apollonius Rhodius, he married the Oceanid of said region, Libya.


title: Triton (mythology)

text: Triton was the son of Poseidon and Amphitrite according to Hesiod's "Theogony". He was the ruler (possessor) of the depths of the sea, who is either "dreadful" or "mighty" () according to the epithet given him by Hesiod.


title: Triton (mythology)

text: Triton dwelt with his parents in underwater golden palaces. Poseidon's golden palace was located at Aegae on Euboea in one passage of Homer's "Iliad" 12.21.


title: Triton (mythology)

text: Unlike his father Poseidon who is always fully anthropomorphic in ancient art (this has only changed in modern popular culture), Triton's lower half is that of a fish, while the top half is presented in a human figure.


title: Triton (mythology)

text: Triton in later times became associated with possessing a conch shell, which he blew like a trumpet to calm or raise the waves. He was "trumpeter and bugler" to Oceanus and Poseidon. Its sound was so cacophonous that when loudly blown, it put the giants to flight, who imagined it to be the roar of a dark wild beast.


title: Triton (mythology)

text: The original Greek Triton only sometimes bore a trident. In literature, Triton carries a trident in Accius's "Medea" fragment.


title: Triton (mythology)

text: Triton is "sea-hued" according to Ovid and "his shoulders barnacled with sea-shells". Ovid actually here calls Triton "cerulean" in color, to choose a cognate rendering to the original language (); Ovid also includes Triton among other deities (Proteus, Aegaeon, Doris) of being this blue color, with green ("") hair, as well describing the steed Triton rides as cerulean.


title: Triton (mythology)

text: There is also Triton, the god of Lake Tritonis of Ancient Libya encountered by the Argonauts. This Triton is treated as a separate deity in some references. He had a different parentage, as his father was Poseidon but his mother Europa according to the Greek writers of this episode.


title: Triton (mythology)

text: This Triton first appeared in the guise of Eurypylus before eventually revealing his divine nature. This local deity has thus been euhemeristically rationalized as "then ruler over Libya" by Diodorus Siculus.


title: Triton (mythology)

text: Triton-Eurypylus welcomed the Argonauts with a guest-gift of a clod of earth which was a pledge that the Greeks would be granted the land of Cyrene, Libya in the future. The "Argo" had been driven ashore in the Syrtes (Gulf of Syrtes Minor according to some), and Triton guided them through the lake's marshy outlet back to the Mediterranean.


title: Triton (mythology)

text: One of the works which recounts this adventure is Apollonius of Rhodes' "Argonautica" (3rd century BC), the first work in written literature that describes a Triton as "fish-tailed".


title: Triton (mythology)

text: In Virgil's "Aeneid", book 6, it is told that Triton killed Misenus, son of Aeolus, by drowning him after he challenged the gods to play as well as he did.


title: Triton (mythology)

text: Herakles wrestling Triton is a common theme in Classical Greek art particularly black-figure pottery, but no literature survives that tells the story. In fewer examples, the Greek pottery depicting apparently the same motif are labeled "Nereus" or "Old Man of the Sea" instead, and among these, Nereus' struggle with Herakles is attested in literature (Pseudo-Apollodorus, "Bibliotheca"). "Old Man of the Sea" is a generic term applicable to Nereus, who was also frequently depicted as half-fishlike. One explanation is that some vase painters developed the convention of depicting Nereus as a fully human form, so that Triton had to be substituted in the depiction of the sea-monster wrestling Herakles. And Nereus appears as a spectator in some examples of this motif.


title: Triton (mythology)

text: In the red-figure period, the Triton-Herakles theme became completely outmoded, supplanted by such scenes as Theseus's adventures in Poseidon's golden mansion, embellished with the presence of Triton. Again, extant literature describing the adventure omits any mention of Triton, but placement of Triton in the scene is not implausible.


title: Triton (mythology)

text: Triton was the father of a daughter named Pallas and foster parent to the goddess Athena, according to Pseudo-Apollodorus's "Bibliotheca". Elsewhere in the "Bibliotheca", there appears a different Pallas (Giant), a male figure overcome by Athena.


title: Triton (mythology)

text: Athena bears the epithet "Tritogeneia" () "Triton-born" and while this is suggestive of Triton's daughter being Athena, the appellation is otherwise explainable in several ways, e.g., as Athena's birth (from Zeus's head) taking place at the River Triton or Lake Tritonis.


title: Triton (mythology)

text: Triton also had a daughter named Triteia. According to Pausanias writing in the 2nd century CE, one origin story of the city of Triteia held that this was an eponymous city after Triteia, founded by her and Ares's son, named Melanippus ("Black Horse").


title: Triton (mythology)

text: At some time during the Greco-Roman period, "Tritons", in the plural, came to be used a generic term for mermen.


title: Triton (mythology)

text: Greek pottery depicting a half-human, half-fish being bearing an inscription of "Triton" is popular by the 6th century BC. It has also been hypothesized that by this time "Triton" has become a generic term for a merman.


title: Triton (mythology)

text: Furthermore, Tritons in groups or multitudes began to be depicted in Classical Greek art by around the 4th century BC. Among these is the work by Greek sculptor Scopas (d. 350 BC) which was later removed to Rome. The sirens of Homer's "Odyssey" were sometimes being depicted, not as human-headed birds but as tritonesses by around this time, as seen in a bowl dated to the 3rd century BC, and this is explained as a conflation with Odysseus's Scylla and Charybdis episode.


title: Triton (mythology)

text: Though not a contemporaneous inscription or commentary, Pliny (d. 79 CE) commented on the work that "there are Nereids riding on dolphins… and also Tritons" in this sculpture.


title: Triton (mythology)

text: In later Greek periods into the Roman period Tritons were depicted as ichthyocentaurs, i.e., merman with a horse's forelegs in place of arms. The earliest known examples are from the 2nd century BC. The term "Ichthyocentaur" did not originate in Ancient Greece, and only appeared in writing in the Byzantine period (12th century); "Centaur-Triton" is another word for a Triton with horse-legs.


title: Triton (mythology)

text: Besides examples in which the horse-like forelimbs have been replaced by wings, there are other examples where the forelegs have several clawed digits (somewhat like lions), as in one relief at the Glyptothek in Munich, Germany. A Triton with a lower extremity like a lobster or crayfish, in a fresco unearthed from Herculanum has been mentioned.


title: Triton (mythology)

text: Double-tailed tritons began to be depicted by the late 2nd century BC, such as in the Altar of Domitius Ahenobarbus. Rumpf thought that might be the earliest example of a "Triton with two fish-tails (Triton mit zwei Fischschwänzen)". However the double-tailed tritonesses in Damophon's sculptures at Lycosura predates it, and even this is doubted to be the first example. Lattimore believed the two-tailed triton should be dated to the 4th century BC, and speculated that Skopas was the one to devise it.


title: Triton (mythology)

text: As aforementioned, there is the female version of the half-human, half-fishlike being, sometimes called a "tritoness" or a "female triton".


title: Triton (mythology)

text: The first literary attestation of Tritons () in the plural was Virgil's "Aeneid" (). In the 1st century CE, another Latin poet Valerius Flaccus wrote in "Argonautica" that there was a huge Triton at each side of Neptune's chariot, holding the reins of horses. And Statius (1st century) makes a Triton figurehead adorn the prow of the "Argo".


title: Triton (mythology)

text: Trions and nereids appear as marine retinues () to the goddess Venus in Apuleius's "Metamorphoses", or "The Golden Ass".


title: Triton (mythology)

text: Pausanias was basing his descriptions on a headless Triton exhibited in Tanagra and another curiosity in Rome. These Tritons were preserved mummies or taxidermied real animals or humans (or fabrication made to appear as such). The Tanagran Triton was seen by Aelian who described it as an embalmed or pickled mummy (). While Pausanias related a legend around the Tanagran Triton that its head was cut off, J. G. Frazer conjectured that such a had to be invented after a sea mammal's carcass with a severed or severely mutilated head was passed off as a Triton.


title: Triton (mythology)

text: Triton was referred to as "trumpeter of Neptune ("Neptuni tubicen")" in Cristoforo Landino (d. 1498)'s commentary on Virgil; this phrasing later appeared in the gloss for "Triton" in Marius Nizolius's "Thesaurus" (1551), and Konrad Gesner's book (1558).


title: Triton (mythology)

text: Triton makes appearance in English literature as the messenger for the god Poseidon. In Edmund Spenser's "Faerie Queene", Triton blew "his trompet shrill before" Neptune and Amphitrite. And in Milton (1637), "Lycidas" v. 89, "The Herald of the Sea" refers to Triton.


title: Triton (mythology)

text: Gianlorenzo Bernini sculpted the "Neptune and Triton" fountain (1622–23) now in the Victoria and Albert Museum and the Triton Fountain (1642–43) in Bernini Square, Rome. There is differing opinion on what earlier works he may have drawn from near-contemporary works or examples from antiquity. He may have been influenced by Battista di Domenico Lorenzi's "Alpheus and Arethusa" (1568–70) or his Triton blowing the conch (late 1570s), or Stoldo Lorenzi's Neptune fountain. But Rudolf Wittkower has cautioned against exaggerating the influences of Florentine fountains. It has been pointed out that Bernini had access to the Papal collection of genuine Greco-Roman sculptures, and worked with restoring ancient fragments, although it is unclear if any Triton was among these. It is within the realm of possibilities that Bernini might have used as his model the ancient Altar of Domitius Ahenobarbus, which does include Triton in its composition. The Triton of this altar, the Stoldo Lorenzi Triton and the Bernini Triton are all double-tailed, like a pair of human legs.


title: Triton (mythology)

text: In Wordsworth's sonnet "The World Is Too Much with Us" (c. 1802, published 1807), the poet regrets the prosaic humdrum modern world, yearning for


title: Triton (mythology)

text: There are numerous universities, colleges, and high schools and businesses that use Triton as their mascot. These include the following:


title: Triton (mythology)

text: The largest moon of the planet Neptune has been given the name Triton, as Neptune is the Roman equivalent of Poseidon. A family of large sea snails, the shells of some of which have been used as trumpets since antiquity, are commonly known as "tritons", see Triton (gastropod).


title: Triton (mythology)

text: The name Triton is associated in modern industry with tough hard-wearing machines such as the Ford Triton engine and Mitsubishi Triton pickup truck.


title: Triton (mythology)

text: The USS Triton (SSN-586) was the only attack submarine of her class, and the only US Navy nuclear-powered submarine to have two reactors. She was decommissioned in 1969 and languished awaiting scrapping until 2007, which began at Puget Sound Naval Shipyard, and was completed as of 30 November 2009.


title: F-test

text: An "F"-test is any statistical test in which the test statistic has an "F"-distribution under the null hypothesis. It is most often used when comparing statistical models that have been fitted to a data set, in order to identify the model that best fits the population from which the data were sampled. Exact ""F"-tests" mainly arise when the models have been fitted to the data using least squares. The name was coined by George W. Snedecor, in honour of Ronald Fisher. Fisher initially developed the statistic as the variance ratio in the 1920s.


title: F-test

text: In addition, some statistical procedures, such as Scheffé's method for multiple comparisons adjustment in linear models, also use "F"-tests.


title: F-test

text: The "F"-test is sensitive to non-normality. In the analysis of variance (ANOVA), alternative tests include Levene's test, Bartlett's test, and the Brown–Forsythe test. However, when any of these tests are conducted to test the underlying assumption of homoscedasticity ("i.e." homogeneity of variance), as a preliminary step to testing for mean effects, there is an increase in the experiment-wise Type I error rate.


title: F-test

text: Most "F"-tests arise by considering a decomposition of the variability in a collection of data in terms of sums of squares. The test statistic in an "F"-test is the ratio of two scaled sums of squares reflecting different sources of variability. These sums of squares are constructed so that the statistic tends to be greater when the null hypothesis is not true. In order for the statistic to follow the "F"-distribution under the null hypothesis, the sums of squares should be statistically independent, and each should follow a scaled χ²-distribution. The latter condition is guaranteed if the data values are independent and normally distributed with a common variance.


title: F-test

text: The "F"-test in one-way analysis of variance (ANOVA) is used to assess whether the expected values of a quantitative variable within several pre-defined groups differ from each other. For example, suppose that a medical trial compares four treatments. The ANOVA "F"-test can be used to assess whether any of the treatments is on average superior, or inferior, to the others versus the null hypothesis that all four treatments yield the same mean response. This is an example of an "omnibus" test, meaning that a single test is performed to detect any of several possible differences. Alternatively, we could carry out pairwise tests among the treatments (for instance, in the medical trial example with four treatments we could carry out six tests among pairs of treatments). The advantage of the ANOVA "F"-test is that we do not need to pre-specify which treatments are to be compared, and we do not need to adjust for making multiple comparisons. The disadvantage of the ANOVA "F"-test is that if we reject the null hypothesis, we do not know which treatments can be said to be significantly different from the others, nor, if the "F"-test is performed at level α, can we state that the treatment pair with the greatest mean difference is significantly different at level α.


title: F-test

text: where formula_4 denotes the sample mean in the "i"-th group, formula_5 is the number of observations in the "i"-th group,formula_6 denotes the overall mean of the data, and formula_7 denotes the number of groups.


title: F-test

text: where formula_9 is the "j" observation in the "i" out of formula_7 groups and formula_11 is the overall sample size. This "F"-statistic follows the "F"-distribution with degrees of freedom formula_12 and formula_13 under the null hypothesis. The statistic will be large if the between-group variability is large relative to the within-group variability, which is unlikely to happen if the population means of the groups all have the same value.


title: F-test

text: Note that when there are only two groups for the one-way ANOVA "F"-test, formula_14where "t" is the Student's formula_15 statistic.


title: F-test

text: Consider two models, 1 and 2, where model 1 is 'nested' within model 2. Model 1 is the restricted model, and model 2 is the unrestricted one. That is, model 1 has "p" parameters, and model 2 has "p" parameters, where "p" < "p", and for any choice of parameters in model 1, the same regression curve can be achieved by some choice of the parameters of model 2.


title: F-test

text: One common context in this regard is that of deciding whether a model fits the data significantly better than does a naive model, in which the only explanatory term is the intercept term, so that all predicted values for the dependent variable are set equal to that variable's sample mean. The naive model is the restricted model, since the coefficients of all potential explanatory variables are restricted to equal zero.


title: F-test

text: Another common context is deciding whether there is a structural break in the data: here the restricted model uses all data in one regression, while the unrestricted model uses separate regressions for two different subsets of the data. This use of the F-test is known as the Chow test.


title: F-test

text: The model with more parameters will always be able to fit the data at least as well as the model with fewer parameters. Thus typically model 2 will give a better (i.e. lower error) fit to the data than model 1. But one often wants to determine whether model 2 gives a "significantly" better fit to the data. One approach to this problem is to use an "F"-test.


title: F-test

text: If there are "n" data points to estimate parameters of both models from, then one can calculate the "F" statistic, given by


title: F-test

text: where RSS is the residual sum of squares of model "i". If the regression model has been calculated with weights, then replace RSS with χ, the weighted sum of squared residuals. Under the null hypothesis that model 2 does not provide a significantly better fit than model 1, "F" will have an "F" distribution, with ("p"−"p", "n"−"p") degrees of freedom. The null hypothesis is rejected if the "F" calculated from the data is greater than the critical value of the "F"-distribution for some desired false-rejection probability (e.g. 0.05). Since "F" is a monotone function of the likelihood ratio statistic, the "F"-test is a likelihood ratio test.


title: Nancy Dolman

text: Nancy Jane Dolman Short (September 26, 1951 – August 21, 2010) was a Canadian comedic actress and singer. She had a recurring role as Annie Selig Tate on the ABC sitcom "Soap". She appeared in her husband Martin Short's 1985 cable television special "Martin Short: Concert for the North Americas".


title: Nancy Dolman

text: Dolman was born in Toronto. Her brother is director Bob Dolman. Dolman performed in the Canadian Rock Theatre production of "Jesus Christ Superstar" in the early 1970s, which travelled to Las Vegas and Los Angeles, and recorded an album with the group at MGM while they were in Los Angeles.


title: Nancy Dolman

text: In 1980, she married fellow Canadian actor Martin Short, whom she had met during the run of the 1972 Toronto production of "Godspell". Dolman was Gilda Radner's understudy. Dolman attended high school at York Mills Collegiate Institute in Toronto, and held a bachelor's degree in philosophy from the University of Western Ontario.


title: Nancy Dolman

text: Dolman retired from show business in 1985 to be a homemaker and full-time mother to her children. A profile of the couple appeared in the February 1987 issue of "Vogue". The family made their home in Pacific Palisades, California. Dolman and Short also kept a vacation home in Lake Rosseau, Ontario.


title: Nancy Dolman

text: Dolman and Short adopted three children: Katherine Elizabeth (born 1983), a social worker and graduate of New York University; Oliver Patrick (born 1986), an employee of Warner Brothers and graduate of the University of Notre Dame's Mendoza College of Business; and Henry Hayter (born 1989), who also graduated from the University of Notre Dame in May 2012.


title: Nancy Dolman

text: Dolman was suffering from ovarian cancer and died on August 21, 2010, in Pacific Palisades, California, at the age of 58. According to the Los Angeles County Coroner, she died of natural causes. Dolman's remains were cremated and her ashes were scattered from the dock of the Short family cottage, onto the waters of Lake Rosseau, Muskoka, Ontario, Canada.


title: Nancy Dolman

text: Steve Martin, a close friend of Dolman and Short, dedicated a musical elegy for Dolman following her death titled, "The Great Remember (For Nancy)" in his collaborative album, "Rare Bird Alert" with the Steep Canyon Rangers.


title: Bicycle Thieves

text: Bicycle Thieves (; sometimes known in the United States as The Bicycle Thief) is a 1948 Italian neorealist drama film directed by Vittorio De Sica. It follows the story of a poor father searching in post-World War II Rome for his stolen bicycle, without which he will lose the job which was to be the salvation of his young family.


title: Bicycle Thieves

text: Adapted for the screen by Cesare Zavattini from the 1946 novel by Luigi Bartolini, and starring Lamberto Maggiorani as the desperate father and Enzo Staiola as his plucky young son, "Bicycle Thieves" received an Academy Honorary Award (most outstanding foreign language film) in 1950, and in 1952 was deemed the greatest film of all time by "Sight & Sound" magazine's poll of filmmakers and critics; fifty years later another poll organized by the same magazine ranked it sixth among the greatest-ever films. In the 2012 version of the list the film ranked 33rd among critics and 10th among directors.


title: Bicycle Thieves

text: The film was also cited by Turner Classic Movies as one of the most influential films in cinema history, and it is considered part of the canon of classic cinema. In 1958, the film was voted number 3 on the prestigious Brussels 12 list at the 1958 World Expo, and number 4 in "Empire" magazine's "The 100 Best Films of World Cinema" in 2010. It was also included on the Italian Ministry of Cultural Heritage’s "100 films to be saved", a list of 100 films that "have changed the collective memory of the country between 1942 and 1978."


title: Bicycle Thieves

text: In the post-World War II Val Melaina neighborhood of Rome, Antonio Ricci (Lamberto Maggiorani) is desperate for work to support his wife Maria (Lianella Carell), his son Bruno (Enzo Staiola) and his small baby. He is offered a job of pasting advertising bills but tells Maria that he cannot accept because the job requires a bicycle. Maria resolutely strips the bed of her dowry bedsheetsprized possessions for a poor familyand takes them to the pawn shop, where they bring enough to redeem Antonio's pawned bicycle.


title: Bicycle Thieves

text: On his first day of work, Antonio is atop a ladder when a young man (Vittorio Antonucci) snatches the bicycle. Antonio gives chase but is thrown off the trail by the thief's confederates. The police warn that there is little they can do. Advised that stolen goods often surface at the Piazza Vittorio market, Antonio goes there with several friends and Bruno. They find a bicycle that might be Antonio's, but the serial numbers do not match.


title: Bicycle Thieves

text: At the Porta Portese market, Antonio and Bruno spot the thief with an old man. The thief eludes them and the old man feigns ignorance. They follow him into a church where he too slips away from them.


title: Bicycle Thieves

text: In a subsequent encounter with the thief, Antonio pursues him into a brothel, whose denizens eject them. In the street, hostile neighbors gather as Antonio accuses the thief, who conveniently falls into a fit for which the crowd blames Antonio. Bruno fetches a policeman, who searches the thief's apartment without success. The policeman tells Antonio the case is weakAntonio has no witnesses and the neighbors are certain to provide the thief with an alibi. Antonio and Bruno leave in despair amid jeers and threats from the crowd.


title: Bicycle Thieves

text: On their way home, they are walking near Stadio Nazionale PNF football stadium. Antonio sees an unattended bicycle near a doorway and after much anguished soul-searching, instructs Bruno to take the tram to a stop nearby and wait. Antonio circles the unattended bicycle and jumps on it. Instantly the hue and cry is raised and Brunowho has missed the tramis stunned to see his father pursued, surrounded and pulled from the bicycle. As Antonio is being muscled toward the police station, the bicycle's owner notices Bruno and in a moment of compassion tells the others to release Antonio.


title: Bicycle Thieves

text: Antonio and Bruno then walk off slowly amid a buffeting crowd. Antonio fights back tears and Bruno takes his hand. The camera watches from behind as they disappear into the crowd.


title: Bicycle Thieves

text: "Bicycle Thieves" is the best-known work of Italian neorealism, the movement that formally began with Roberto Rossellini's "Rome, Open City" (1945) and aimed to give cinema a new degree of realism. De Sica had just made "Shoeshine" (1946), but was unable to get financial backing from any major studio for the film, so he raised the money himself from friends. Wanting to portray the poverty and unemployment of post-war Italy, he co-wrote a script with Cesare Zavattini and others using only the title and few plot devices of a little-known novel of the time by poet and artist Luigi Bartolini. Following the precepts of neorealism, De Sica shot only on location (that is, no studio sets) and cast only untrained actors. (Lamberto Maggiorani, for example, was a factory worker.) That some actors' roles paralleled their lives off screen added realism to the film. De Sica cast Maggiorani when he had brought his young son to an audition for the film. He later cast the 8-year-old Enzo Staiola when he noticed the young boy watching the film's production on a street while helping his father sell flowers. The film's final shot of Antonio and Bruno walking away from the camera into the distance is an homage to many of the films of Charlie Chaplin, who was De Sica's favourite filmmaker.


title: Bicycle Thieves

text: The original Italian title is "Ladri di biciclette". It literally translates into English as "Bicycles Thieves", as there is no definite article and both "ladri" and "biciclette" are plural. The film was released as "Bicycle Thieves" in the United States and the United Kingdom. The poster titles were "The Bicycle Thief" in the US and "The Bicycle Thieves" in the UK.


title: Bicycle Thieves

text: Bosley Crowther used "The Bicycle Thief" in his 1949 review in "The New York Times", and as a result this came to be the title by which the film was known in the United States, and some people became attached to it. When the film was re-released in the late-1990s, Bob Graham, staff film critic for the "San Francisco Chronicle", was quoted as saying that he preferred the title "The Bicycle Thief", stating, "Purists have criticized the English title of the film as a poor translation of the Italian "ladri", which is plural. What blindness! "The Bicycle Thief" is one of those wonderful titles whose power does not sink in until the film is over".


title: Bicycle Thieves

text: According to critic Philip French of "The Observer", the alternative title "The Bicycle Thief" is misleading, "because the desperate hero eventually becomes himself a bicycle thief". The 2007 Criterion Collection release in North America uses the plural title.


title: Bicycle Thieves

text: De Sica changed many aspects of Bartolini's novel, but retained the title, which used the plural form and referred, in the book, to a post-war culture of rampant thievery and disrespect for civil order countered only by an inept police force and indifferent allied occupiers.


title: Bicycle Thieves

text: When "Bicycle Thieves" was released in Italy, it was viewed with hostility and as portraying Italians in a negative way. Italian critic Guido Aristarco praised it, but also complained that "sentimentality might at times take the place of artistic emotion." Fellow Italian neorealist film director Luchino Visconti criticized the film, saying that it was a mistake to use a professional actor to dub over Lamberto Maggiorani's dialogue. Luigi Bartolini, the author of the novel from which de Sica drew his title, was highly critical of the film, feeling that the spirit of his book had been thoroughly betrayed because his protagonist was a middle-class intellectual and his theme was the breakdown of civil order.


title: Bicycle Thieves

text: "Bicycle Thieves" has continued to gain very high praise from critics, with the review aggregator website Rotten Tomatoes reporting 99% of 67 contemporary reviews as positive, with an average rating of 9.20/10. The site's critics consensus reads, "An Italian neorealism exemplar, "Bicycle Thieves" thrives on its non-flashy performances and searing emotion." The picture is also in the Vatican's Best Films List for portraying humanistic values.


title: Bicycle Thieves

text: Bosley Crowther, film critic for "The New York Times", lauded the film and its message in his review. He wrote, "Again the Italians have sent us a brilliant and devastating film in Vittorio De Sica's rueful drama of modern city life, "The Bicycle Thief." Widely and fervently heralded by those who had seen it abroad (where it already has won several prizes at various film festivals), this heart-tearing picture of frustration, which came to [the World Theater] yesterday, bids fair to fulfill all the forecasts of its absolute triumph over here. For once more the talented De Sica, who gave us the shattering "Shoeshine", that desperately tragic demonstration of juvenile corruption in post-war Rome, has laid hold upon and sharply imaged in simple and realistic terms a majorindeed, a fundamental and universaldramatic theme. It is the isolation and loneliness of the little man in this complex social world that is ironically blessed with institutions to comfort and protect mankind". Pierre Leprohon wrote in "Cinéma D'Aujourd" that "what must not be ignored on the social level is that the character is shown not at the beginning of a crisis but at its outcome. One need only to look at his face, his uncertain gait, his hesitant or fearful attitudes to understand that Ricci is already a victim, a diminished man who has lost his confidence." Lotte Eisner called it the best Italian film since World War II and Robert Winnington called it "the most successful record of any foreign film in British cinema."


title: Bicycle Thieves

text: When the film was re-released in the late 1990s Bob Graham, staff film critic for the "San Francisco Chronicle", gave the drama a positive review: "The roles are played by non-actors, Lamberto Maggiorani as the father and Enzo Staiola as the solemn boy, who sometimes appears to be a miniature man. They bring a grave dignity to De Sica's unblinking view of post-war Italy. The wheel of life turns and grinds people down; the man who was riding high in the morning is brought low by nightfall. It is impossible to imagine this story in any other form than De Sica's. The new black-and-white print has an extraordinary range of grey tones that get darker as life closes in". In 1999, "Chicago Sun-Times" film reviewer Roger Ebert wrote that "The Bicycle Thief" is so well-entrenched as an official masterpiece that it is a little startling to visit it again after many years and realize that it is still alive and has strength and freshness. Given an honorary Oscar in 1949, routinely voted one of the greatest films of all time, revered as one of the foundation stones of Italian neorealism, it is a simple, powerful film about a man who needs a job". Ebert added the film to his "Great Movies" list. In 2020, A. O. Scott praised the film in an essay entitled "Why You Should Still Care About 'Bicycle Thieves'."


title: Bicycle Thieves

text: "Bicycle Thieves" is a fixture on the British Film Institute's "Sight & Sound" critics' and directors' polls of the greatest films ever made. The film ranked 1st and 7th on critics' poll in 1952 and 1962 respectively. It ranked 11th on the magazine's 1992 Critics' poll, 45th in 2002 "Critics' Poll" and 6th on the 2002 "Directors' Top Ten Poll". It was slightly lower in the 2012 directors' poll, 10th and 33rd on the 2012 critics' poll. "The Village Voice" ranked the film at number 37 in its Top 250 "Best Films of the Century" list in 1999, based on a poll of critics. The film was voted at No. 99 on the list of "100 Greatest Films" by the prominent French magazine "Cahiers du cinéma" in 2008.


title: Bicycle Thieves

text: Many directors have cited it as a major influence including Satyajit Ray, Ken Loach, Giorgio Mangiamele, Bimal Roy, Anurag Kashyap, Balu Mahendra, Vetrimaaran and Basu Chatterjee.


title: Bicycle Thieves

text: The film was noteworthy for film directors of the Iranian New Wave, such as Jafar Panahi and Dariush Mehrjui.


title: Bicycle Thieves

text: Filipino action star Nelson Anderson said it was the favorite Italian neorealist film of his contemporary Weng Weng, who cried upon his first viewing in the early 1980s. In a project that never materialized, they intended to depart from their usual fare by remaking it as an action-comedy with a human touch.


title: Bicycle Thieves

text: The film features in the 1992 Robert Altman film "The Player". In this film Griffin Mill (played by Tim Robbins), a Hollywood studio executive, tracks screenwriter David Kahane (played by Vincent D'Onofrio) to a screening of "Bicycle Thieves", and stages what he represents as a chance meeting with Kahane. Kahane's suspicion is roused by the fact that Mill entered the screening only in the last few minutes of the film, and the two have an argument afterwards, resulting in Kahane's death. Anyone otherwise unaware viewing the last few minutes of "Bicycle Thieves" - comprising Antonio's attempted theft - would gain a distorted perspective on Antonio's motives, just as Mill misjudges Kahane, whom he wrongly thinks has been sending him hate mail.


title: Bicycle Thieves

text: A theatrical adaptation of the film was created by Littlebrain Theatre, in a devised adaptation with a cast of nine. The production premiered as part of the Rhinoceros Theatre Festival in Chicago, from January 18 to February 22, 2019.


title: Caribbean Netherlands

text: The Caribbean Netherlands (, ) are the three special municipalities of the Netherlands that are located in the Caribbean Sea. They consist of the islands of Bonaire, Sint Eustatius and Saba, although the term "Caribbean Netherlands" is sometimes used to refer to all of the islands in the Dutch Caribbean. In legislation, the three islands are also known as Bonaire, Sint Eustatius and Saba or the BES islands (an acronym of their names). The islands are currently classified as "public bodies" in the Netherlands and as overseas countries and territories of the European Union; thus, EU law does not automatically apply.


title: Caribbean Netherlands

text: Bonaire (including the islet of Klein Bonaire) is one of the Leeward Antilles and is located close to the coast of Venezuela. Sint Eustatius and Saba are in the main Lesser Antilles group and are located south of Sint Maarten and northwest of Saint Kitts and Nevis. The Caribbean Netherlands has a population of 25,157 as of January 2019.


title: Caribbean Netherlands

text: The three islands gained their current status following the dissolution of the Netherlands Antilles on 10 October 2010. At the same time, the islands of Curaçao and Sint Maarten became autonomous countries () within the Kingdom of the Netherlands. The island of Aruba is also a constituent country of the Kingdom located in the Caribbean. The term "Dutch Caribbean" may refer to the three special municipalities (e.g. for stamps), but may also refer to all of the Caribbean islands within the Kingdom of the Netherlands. The population of the Caribbean Netherlands is . Their total area is . These figures are not consistent with the table below.


title: Caribbean Netherlands

text: In 2012, the islands of the Caribbean Netherlands voted for the first time, due to being special municipalities of the Kingdom of the Netherlands, in the 2012 Dutch general election.


title: Caribbean Netherlands

text: The special municipalities () carry many of the functions normally performed by Dutch municipalities. The executive power rests with the Governing Council headed by an Island governor. The main democratic body is the island council. Dutch citizens of these three islands are entitled to vote in Dutch national elections and (as all Dutch nationals) in European elections.


title: Caribbean Netherlands

text: Officially the islands are classed in Dutch law as being (literally translated as "public bodies") and not (municipalities). Unlike normal municipalities, they do not form part of a Dutch province and the powers normally exercised by provincial councils within municipalities are divided between the island governments themselves and the central government by means of the National Office for the Caribbean Netherlands. For this reason, they are called "special" municipalities.


title: Caribbean Netherlands

text: Many Dutch laws make special provisions for the Caribbean Netherlands. For example, social security is not on the same level as it is in the European Netherlands.


title: Caribbean Netherlands

text: The "National Office for the Caribbean Netherlands" () is responsible for taxation, policing, immigration, transport infrastructure, health, education, and social security in the islands and provides these services on behalf of the Government of the Netherlands. This agency was established as the Regional Service Center in 2008 and became the National Office for the Caribbean Netherlands on 1 September 2010. The current director is Jan Helmond. The "Representative for the public bodies of Bonaire, Sint Eustatius and Saba" represents the Government of the Netherlands on the islands and also performs tasks similar to a King's Commissioner. The current representative is Gilbert Isabella.


title: Caribbean Netherlands

text: The islands do not form part of the European Union and instead constitute "overseas countries and territories" (OCT status) of the Union, to which special provisions apply. The Lisbon Treaty introduced a procedure where the European Council may change the status of an overseas territory of Denmark, France, or the Netherlands regarding the application of the EU treaties to that territory. In June 2008, the Dutch government published a survey of the legal and economic impacts by a switched status from OCT to outermost region (OMR). The position of the islands was reviewed after a five-year transitional period, which began with the dissolution of the Netherlands Antilles in October 2010. The review was conducted as part of the planned review of the Dutch "Act for the public bodies Bonaire, Sint Eustatius and Saba" (), where the islands have been granted the option to become an OMR – and thus a direct part of the European Union. In October 2015, the review concluded the present legal structures for governance and integration with European Netherlands was not working well within the framework of WolBES, but no recommendations were made in regards of whether a switch from OCT to OMR status would help improve this situation.


title: Caribbean Netherlands

text: The Kingdom of the Netherlands has overarching responsibility for foreign relations, defence and Dutch nationality law in the Caribbean parts of the Kingdom. Units of the Netherlands Armed Forces deployed in the Caribbean include:


title: Caribbean Netherlands

text: Additionally, the Dutch Caribbean Coast Guard is funded by the four countries of the Kingdom of the Netherlands. The Coast Guard is managed by the Ministry of Defence and is directed by the commander of the Royal Netherlands Navy in the Caribbean.


title: Caribbean Netherlands

text: The islands of the Caribbean Netherlands enjoy a tropical climate with warm weather all year round. The Leeward Antilles are warmer and drier than the Windward islands. In summer, the Windward Islands can be subject to hurricanes.


title: Caribbean Netherlands

text: Until 1 January 2011, the three islands used the Netherlands Antillean guilder; after that all three switched to the U.S. dollar, rather than the euro (which is used in the European Netherlands) or the Caribbean guilder (which is being adopted by the other two former Antillean islands of Curaçao and Sint Maarten).


title: Caribbean Netherlands

text: The telephone country code remains 599, that of the former Netherlands Antilles, and is shared with Curaçao. The International Organization for Standardization has assigned the ISO 3166-1 alpha-2 country code for these islands. The IANA has not established a root zone for the .bq Internet ccTLD and whether it will be used is unknown.


title: Nitrogen dioxide

text: Nitrogen dioxide is a chemical compound with the formula . It is one of several nitrogen oxides. is an intermediate in the industrial synthesis of nitric acid, millions of tons of which are produced each year for use primarily in the production of fertilizers. At higher temperatures it is a reddish-brown gas. It can be fatal if inhaled in large quantities. Nitrogen dioxide is a paramagnetic, bent molecule with C point group symmetry.


title: Nitrogen dioxide

text: Nitrogen dioxide is a reddish-brown gas with a pungent, acrid odor above , becomes a yellowish-brown liquid below , and converts to the colorless dinitrogen tetroxide () below .


title: Nitrogen dioxide

text: The bond length between the nitrogen atom and the oxygen atom is 119.7 pm. This bond length is consistent with a bond order between one and two.


title: Nitrogen dioxide

text: Unlike ozone, O, the ground electronic state of nitrogen dioxide is a doublet state, since nitrogen has one unpaired electron, which decreases the alpha effect compared with nitrite and creates a weak bonding interaction with the oxygen lone pairs. The lone electron in also means that this compound is a free radical, so the formula for nitrogen dioxide is often written as .


title: Nitrogen dioxide

text: The reddish-brown color is a consequence of preferential absorption of light in the blue region of the spectrum (400 – 500 nm), although the absorption extends throughout the visible (at shorter wavelengths) and into the infrared (at longer wavelengths). Absorption of light at wavelengths shorter than about 400 nm results in photolysis (to form NO + O, atomic oxygen); in the atmosphere the addition of the oxygen atom so formed to O results in ozone.


title: Nitrogen dioxide

text: Nitrogen dioxide typically arises via the oxidation of nitric oxide by oxygen in air (e.g. as result of corona discharge):


title: Nitrogen dioxide

text: Nitrogen dioxide is formed in most combustion processes using air as the oxidant. At elevated temperatures nitrogen combines with oxygen to form nitric oxide:


title: Nitrogen dioxide

text: In the laboratory, can be prepared in a two-step procedure where dehydration of nitric acid produces dinitrogen pentoxide:


title: Nitrogen dioxide

text: The equilibrium is characterized by , which is exothermic. NO is favored at higher temperatures, while at lower temperatures, NO predominates. can be obtained as a white solid with melting point −11.2 °C. NO is paramagnetic due to its unpaired electron, while NO is diamagnetic.


title: Nitrogen dioxide

text: As suggested by the weakness of the N–O bond, is a good oxidizer. Consequently, it will combust, sometimes explosively, in the presence of hydrocarbons.


title: Nitrogen dioxide

text: This reaction is one of the steps in the Ostwald process for the industrial production of nitric acid from ammonia. This reaction is negligibly slow at low concentrations of NO characteristic of the ambient atmosphere, although it does proceed upon NO uptake to surfaces. Such surface reaction is thought to produce gaseous HNO (often written as HONO) in outdoor and indoor environments.


title: Nitrogen dioxide

text: is introduced into the environment by natural causes, including entry from the stratosphere, bacterial respiration, volcanos, and lightning. These sources make a trace gas in the atmosphere of Earth, where it plays a role in absorbing sunlight and regulating the chemistry of the troposphere, especially in determining ozone concentrations.


title: Nitrogen dioxide

text: is used as an intermediate in the manufacturing of nitric acid, as a nitrating agent in manufacturing of chemical explosives, as a polymerization inhibitor for acrylates, as a flour bleaching agent, and as a room temperature sterilization agent. It is also used as an oxidizer in rocket fuel, for example in red fuming nitric acid; it was used in the Titan rockets, to launch Project Gemini, in the maneuvering thrusters of the Space Shuttle, and in unmanned space probes sent to various planets.


title: Nitrogen dioxide

text: For the general public, the most prominent sources of are internal combustion engines, as combustion temperatures are high enough to thermally combine some of the nitrogen and oxygen in the air to form . Outdoors, can be a result of traffic from motor vehicles.


title: Nitrogen dioxide

text: Workers in industries where is used are also exposed and are at risk for occupational lung diseases, and NIOSH has set exposure limits and safety standards. Workers in high voltage areas especially those with spark or plasma creation are at risk. Agricultural workers can be exposed to arising from grain decomposing in silos; chronic exposure can lead to lung damage in a condition called "silo-filler's disease".


title: Nitrogen dioxide

text: diffuses into the epithelial lining fluid (ELF) of the respiratory epithelium and dissolves. There, it chemically reacts with antioxidant and lipid molecules in the ELF. The health effects of are caused by the reaction products or their metabolites, which are reactive nitrogen species and reactive oxygen species that can drive bronchoconstriction, inflammation, reduced immune response, and may have effects on the heart.


title: Nitrogen dioxide

text: Acute harm due to exposure is rare.100–200 ppm can cause mild irritation of the nose and throat, 250–500 ppm can cause edema, leading to bronchitis or pneumonia, and levels above 1000 ppm can cause death due to asphyxiation from fluid in the lungs. There are often no symptoms at the time of exposure other than transient cough, fatigue or nausea, but over hours inflammation in the lungs causes edema.


title: Nitrogen dioxide

text: For skin or eye exposure, the affected area is flushed with saline. For inhalation, oxygen is administered, bronchodilators may be administered, and if there are signs of methemoglobinemia, a condition that arises when nitrogen-based compounds affect the hemoglobin in red blood cells, methylene blue may be administered.


title: Nitrogen dioxide

text: It is classified as an extremely hazardous substance in the United States as defined in Section 302 of the U.S. Emergency Planning and Community Right-to-Know Act (42 U.S.C. 11002), and it is subject to strict reporting requirements by facilities which produce, store, or use it in significant quantities.


title: Nitrogen dioxide

text: Chronic exposure to can cause respiratory effects including airway inflammation in healthy people and increased respiratory symptoms in people with asthma.


title: Nitrogen dioxide

text: The effects of toxicity on health have been examined using questionnaires and in-person interviews in an effort to understand the relationship between and asthma. The influence of indoor air pollutants on health is important because the majority of people in the world spend more than 80% of their time indoors. The amount of time spent indoors depends upon on several factors including geographical region, job activities, and gender among other variables. Additionally, because home insulation is improving, this can result in greater retention of indoor air pollutants, such as . With respect to geographic region, the prevalence of asthma has ranged from 2 to 20% with no clear indication as to what's driving the difference. This may be a result of the "hygiene hypothesis" or "western lifestyle" that captures the notions of homes that are well insulated and with fewer inhabitants. Another study examined the relationship between nitrogen exposure in the home and respiratory symptoms and found a statistically significant odds ratio of 2.23 (95% CI: 1.06, 4.72) among those with a medical diagnosis of asthma and gas stove exposure.


title: Nitrogen dioxide

text: A major source of indoor exposure to is the use of gas stoves for cooking or heating in homes. According to the 2000 census, over half of US households use gas stoves and indoor exposure levels of are, on average, at least three times higher in homes with gas stoves compared to electric stoves with the highest levels being in multifamily homes. Exposure to is especially harmful for children with asthma. Research has shown that children with asthma who live in homes with gas stoves have greater risk of respiratory symptoms such as wheezing, cough and chest tightness. Additionally, gas stove use was associated with reduced lung function in girls with asthma, although this association was not found in boys. Using ventilation when operating gas stoves may reduce the risk of respiratory symptoms in children with asthma.


title: Nitrogen dioxide

text: In a cohort study with inner-city minority African American Baltimore children to determine if there was a relationship between and asthma for children aged 2 to 6 years old, with an existing medical diagnosis of asthma, and one asthma related visit, families of lower socioeconomic status were more likely to have gas stoves in their homes. The study concluded that higher levels of within a home were linked to a greater level of respiratory symptoms among the study population. This further exemplifies that toxicity is dangerous for children.


title: Nitrogen dioxide

text: Interaction of and other with water, oxygen and other chemicals in the atmosphere can form acid rain which harms sensitive ecosystems such as lakes and forests. Elevated levels of can also harm vegetation, decreasing growth, and reduce crop yields.


title: Christine Lahti

text: Christine Ann Lahti (born April 4, 1950) is an American actress and filmmaker. She was nominated for the Academy Award for Best Supporting Actress for the 1984 film "Swing Shift". Her other film roles include "...And Justice for All" (1979), "Housekeeping" (1987), "Running on Empty" (1988), "Leaving Normal" (1992), and "A Beautiful Day in the Neighborhood" (2019). For her directorial debut with the 1995 short film "Lieberman in Love", she won the Academy Award for Best Live Action Short Film.


title: Christine Lahti

text: Lahti made her Broadway debut in 1980 as a replacement in "Loose Ends", and went on to star in the Broadway productions of "Present Laughter" (1982) and "The Heidi Chronicles" (1989). An eight-time Golden Globe nominee and six-time Emmy Award nominee, she won a Golden Globe for the 1989 TV movie "No Place Like Home", and won a Golden Globe and an Emmy in 1998 for her role as Kate Austin in the CBS series "Chicago Hope" (1995–99). She returned to Broadway in 2009 to star in "God of Carnage". She also had a recurring role as Sonya Paxton in the NBC series "" (2009–11), as Doris McGarrett in the CBS series "Hawaii Five-0" (2012–19), and Laurel Hitchin in NBC's "The Blacklist" (2015–17). She currently appears as Sheryl Luria in the CBS/Paramount+ series "Evil".


title: Christine Lahti

text: Lahti was born in Birmingham, Michigan, the daughter of Elizabeth Margaret (née Tabar), a painter, homemaker, and nurse, and Paul Theodore Lahti, a surgeon. She has three sisters, Carol, Catherine, and Linda, and two brothers, Paul Jr. and James Lahti. Her paternal grandparents were Finnish immigrants and her maternal grandparents were from Austria-Hungary. Lahti was raised in the Lutheran Church.


title: Christine Lahti

text: Lahti studied Fine Arts at Florida State University and received her bachelor's degree in Drama from the University of Michigan, where she joined Delta Gamma sorority. She studied acting at HB Studio in New York City, as well as completing a two year professional actor training program at the William Esper Studio for the performing arts in Manhattan.


title: Christine Lahti

text: After college, Lahti headed to New York City in 1973, where she worked as a waitress and did commercials. Her breakthrough movie was "...And Justice for All" (1979) with Al Pacino. In the film "Whose Life Is It Anyway?" (1981), starring Richard Dreyfuss and John Cassavetes, she was cast as a physician who grows attached to a paralyzed patient seeking the right to leave the hospital. Later, she was cast in an important role in "Running on Empty", a 1988 movie in which she and Judd Hirsch played the parents of a musically promising son; the family went underground to avoid the FBI after the parents had damaged a napalm factory, and they all must periodically move on short notice and assume new identities. She has also focused on television, beginning with her role in the made-for-TV adaptation of "The Executioner's Song" (1982). She appeared on Broadway in Wendy Wasserstein's seriocomic play, "The Heidi Chronicles".


title: Christine Lahti

text: Lahti received an Academy Award nomination for Best Supporting Actress for "Swing Shift" (1984), and won an Academy Award for Best Short Film, Live Action for "Lieberman in Love" (1995), in which she starred and directed. It was adapted from "Lieberman in Love", a short story by W. P. Kinsella. Lahti won a Primetime Emmy Award and a Golden Globe Award in 1998 for her role in "Chicago Hope". Christine was in the bathroom when she won the third award and finally came to the stage following an attempt by show producer John Tinker to accept on her behalf and an interruptive riff by Robin Williams. In 1999, she presented with a piece of toilet paper attached to her shoe.


title: Christine Lahti

text: In 2001, her first directorial feature-length film, "My First Mister", was released. Starring Leelee Sobieski and Albert Brooks, the movie debuted with good reviews. In DVD commentary she applauds the work of her cast and crew, remarking "[I] was very lucky to have such a wonderful crew..." She said she felt regret that the film was rated R, for language, despairing that the movie might not be viewed by teens who would relate with the characters. Also, Lahti mentioned that she would have liked to have had more time to shoot different perspectives in order to facilitate story arc.


title: Christine Lahti

text: Lahti starred in the executive ADA role on" " as Sonya Paxton while the character Alexandra Cabot (Stephanie March) was in appeals. She was in the first four episodes of the 11th season and returned for the show's eighth episode, where she clashed with Alexandra Cabot (Stephanie March). Lahti later guest starred in the ninth and 17th episodes of the , where she reprised her role as Paxton. Her character was murdered in the 17th episode.


title: Christine Lahti

text: She returned to Broadway upon joining the cast of the Tony Award–winning play "God of Carnage" on November 17, 2009, replacing Marcia Gay Harden. Both actresses had a few special appearances on "Law & Order: Special Victims Unit". In September 2011, Lahti starred with Morgan Freeman in the Broadway debut of Dustin Lance Black's play, "8"—a reenactment of the federal trial that overturned California's Prop 8 ban on same-sex marriage—as Kris Perry. In March 2012, she was featured with Jamie Lee Curtis and Jansen Panettiere at the Wilshire Ebell Theatre. The production was broadcast on YouTube to raise money for the American Foundation for Equal Rights.


title: Christine Lahti

text: In 2020, Lahti appeared as a guest on the "Studio 60 on the Sunset Strip" marathon fundraiser episode of "The George Lucas Talk Show."


title: Christine Lahti

text: Lahti has been married to television director Thomas Schlamme since September 4, 1983. They have three children. Lahti resides in Los Angeles, California, with her family. She also owns an apartment in Greenwich Village.